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 /mpc824x Files specific to Freescale MPC824x CPUs
205 /mpc8260 Files specific to Freescale MPC8260 CPUs
206 /mpc85xx Files specific to Freescale MPC85xx CPUs
207 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
208 /lib Architecture specific library files
209 /sh Files generic to SH architecture
210 /cpu CPU specific files
211 /sh2 Files specific to sh2 CPUs
212 /sh3 Files specific to sh3 CPUs
213 /sh4 Files specific to sh4 CPUs
214 /lib Architecture specific library files
215 /sparc Files generic to SPARC architecture
216 /cpu CPU specific files
217 /leon2 Files specific to Gaisler LEON2 SPARC CPU
218 /leon3 Files specific to Gaisler LEON3 SPARC CPU
219 /lib Architecture specific library files
220 /api Machine/arch independent API for external apps
221 /board Board dependent files
222 /common Misc architecture independent functions
223 /disk Code for disk drive partition handling
224 /doc Documentation (don't expect too much)
225 /drivers Commonly used device drivers
226 /examples Example code for standalone applications, etc.
227 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
228 /include Header Files
229 /lib Files generic to all architectures
230 /libfdt Library files to support flattened device trees
231 /lzma Library files to support LZMA decompression
232 /lzo Library files to support LZO decompression
234 /post Power On Self Test
235 /rtc Real Time Clock drivers
236 /tools Tools to build S-Record or U-Boot images, etc.
238 Software Configuration:
239 =======================
241 Configuration is usually done using C preprocessor defines; the
242 rationale behind that is to avoid dead code whenever possible.
244 There are two classes of configuration variables:
246 * Configuration _OPTIONS_:
247 These are selectable by the user and have names beginning with
250 * Configuration _SETTINGS_:
251 These depend on the hardware etc. and should not be meddled with if
252 you don't know what you're doing; they have names beginning with
255 Later we will add a configuration tool - probably similar to or even
256 identical to what's used for the Linux kernel. Right now, we have to
257 do the configuration by hand, which means creating some symbolic
258 links and editing some configuration files. We use the TQM8xxL boards
262 Selection of Processor Architecture and Board Type:
263 ---------------------------------------------------
265 For all supported boards there are ready-to-use default
266 configurations available; just type "make <board_name>_config".
268 Example: For a TQM823L module type:
273 For the Cogent platform, you need to specify the CPU type as well;
274 e.g. "make cogent_mpc8xx_config". And also configure the cogent
275 directory according to the instructions in cogent/README.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Board flavour: (if CONFIG_MPC8260ADS is defined)
327 CONFIG_SYS_8260ADS - original MPC8260ADS
328 CONFIG_SYS_8266ADS - MPC8266ADS
329 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
330 CONFIG_SYS_8272ADS - MPC8272ADS
332 - Marvell Family Member
333 CONFIG_SYS_MVFS - define it if you want to enable
334 multiple fs option at one time
335 for marvell soc family
337 - MPC824X Family Member (if CONFIG_MPC824X is defined)
338 Define exactly one of
339 CONFIG_MPC8240, CONFIG_MPC8245
341 - 8xx CPU Options: (if using an MPC8xx CPU)
342 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
343 get_gclk_freq() cannot work
344 e.g. if there is no 32KHz
345 reference PIT/RTC clock
346 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
349 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
350 CONFIG_SYS_8xx_CPUCLK_MIN
351 CONFIG_SYS_8xx_CPUCLK_MAX
352 CONFIG_8xx_CPUCLK_DEFAULT
353 See doc/README.MPC866
355 CONFIG_SYS_MEASURE_CPUCLK
357 Define this to measure the actual CPU clock instead
358 of relying on the correctness of the configured
359 values. Mostly useful for board bringup to make sure
360 the PLL is locked at the intended frequency. Note
361 that this requires a (stable) reference clock (32 kHz
362 RTC clock or CONFIG_SYS_8XX_XIN)
364 CONFIG_SYS_DELAYED_ICACHE
366 Define this option if you want to enable the
367 ICache only when Code runs from RAM.
372 Specifies that the core is a 64-bit PowerPC implementation (implements
373 the "64" category of the Power ISA). This is necessary for ePAPR
374 compliance, among other possible reasons.
376 CONFIG_SYS_FSL_TBCLK_DIV
378 Defines the core time base clock divider ratio compared to the
379 system clock. On most PQ3 devices this is 8, on newer QorIQ
380 devices it can be 16 or 32. The ratio varies from SoC to Soc.
382 CONFIG_SYS_FSL_PCIE_COMPAT
384 Defines the string to utilize when trying to match PCIe device
385 tree nodes for the given platform.
387 CONFIG_SYS_PPC_E500_DEBUG_TLB
389 Enables a temporary TLB entry to be used during boot to work
390 around limitations in e500v1 and e500v2 external debugger
391 support. This reduces the portions of the boot code where
392 breakpoints and single stepping do not work. The value of this
393 symbol should be set to the TLB1 entry to be used for this
396 CONFIG_SYS_FSL_ERRATUM_A004510
398 Enables a workaround for erratum A004510. If set,
399 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
400 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
402 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
405 Defines one or two SoC revisions (low 8 bits of SVR)
406 for which the A004510 workaround should be applied.
408 The rest of SVR is either not relevant to the decision
409 of whether the erratum is present (e.g. p2040 versus
410 p2041) or is implied by the build target, which controls
411 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
413 See Freescale App Note 4493 for more information about
416 CONFIG_A003399_NOR_WORKAROUND
417 Enables a workaround for IFC erratum A003399. It is only
418 requred during NOR boot.
420 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
422 This is the value to write into CCSR offset 0x18600
423 according to the A004510 workaround.
425 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
426 This value denotes start offset of M2 memory
427 which is directly connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 - Generic CPU options:
433 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
435 Defines the endianess of the CPU. Implementation of those
436 values is arch specific.
438 - Intel Monahans options:
439 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
441 Defines the Monahans run mode to oscillator
442 ratio. Valid values are 8, 16, 24, 31. The core
443 frequency is this value multiplied by 13 MHz.
445 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
447 Defines the Monahans turbo mode to oscillator
448 ratio. Valid values are 1 (default if undefined) and
449 2. The core frequency as calculated above is multiplied
453 CONFIG_SYS_INIT_SP_OFFSET
455 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
456 pointer. This is needed for the temporary stack before
459 CONFIG_SYS_MIPS_CACHE_MODE
461 Cache operation mode for the MIPS CPU.
462 See also arch/mips/include/asm/mipsregs.h.
464 CONF_CM_CACHABLE_NO_WA
467 CONF_CM_CACHABLE_NONCOHERENT
471 CONF_CM_CACHABLE_ACCELERATED
473 CONFIG_SYS_XWAY_EBU_BOOTCFG
475 Special option for Lantiq XWAY SoCs for booting from NOR flash.
476 See also arch/mips/cpu/mips32/start.S.
478 CONFIG_XWAY_SWAP_BYTES
480 Enable compilation of tools/xway-swap-bytes needed for Lantiq
481 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
482 be swapped if a flash programmer is used.
485 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
487 Select high exception vectors of the ARM core, e.g., do not
488 clear the V bit of the c1 register of CP15.
490 CONFIG_SYS_THUMB_BUILD
492 Use this flag to build U-Boot using the Thumb instruction
493 set for ARM architectures. Thumb instruction set provides
494 better code density. For ARM architectures that support
495 Thumb2 this flag will result in Thumb2 code generated by
498 CONFIG_ARM_ERRATA_716044
499 CONFIG_ARM_ERRATA_742230
500 CONFIG_ARM_ERRATA_743622
501 CONFIG_ARM_ERRATA_751472
503 If set, the workarounds for these ARM errata are applied early
504 during U-Boot startup. Note that these options force the
505 workarounds to be applied; no CPU-type/version detection
506 exists, unlike the similar options in the Linux kernel. Do not
507 set these options unless they apply!
512 The frequency of the timer returned by get_timer().
513 get_timer() must operate in milliseconds and this CONFIG
514 option must be set to 1000.
516 - Linux Kernel Interface:
519 U-Boot stores all clock information in Hz
520 internally. For binary compatibility with older Linux
521 kernels (which expect the clocks passed in the
522 bd_info data to be in MHz) the environment variable
523 "clocks_in_mhz" can be defined so that U-Boot
524 converts clock data to MHZ before passing it to the
526 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
527 "clocks_in_mhz=1" is automatically included in the
530 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
532 When transferring memsize parameter to linux, some versions
533 expect it to be in bytes, others in MB.
534 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
538 New kernel versions are expecting firmware settings to be
539 passed using flattened device trees (based on open firmware
543 * New libfdt-based support
544 * Adds the "fdt" command
545 * The bootm command automatically updates the fdt
547 OF_CPU - The proper name of the cpus node (only required for
548 MPC512X and MPC5xxx based boards).
549 OF_SOC - The proper name of the soc node (only required for
550 MPC512X and MPC5xxx based boards).
551 OF_TBCLK - The timebase frequency.
552 OF_STDOUT_PATH - The path to the console device
554 boards with QUICC Engines require OF_QE to set UCC MAC
557 CONFIG_OF_BOARD_SETUP
559 Board code has addition modification that it wants to make
560 to the flat device tree before handing it off to the kernel
564 This define fills in the correct boot CPU in the boot
565 param header, the default value is zero if undefined.
569 U-Boot can detect if an IDE device is present or not.
570 If not, and this new config option is activated, U-Boot
571 removes the ATA node from the DTS before booting Linux,
572 so the Linux IDE driver does not probe the device and
573 crash. This is needed for buggy hardware (uc101) where
574 no pull down resistor is connected to the signal IDE5V_DD7.
576 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
578 This setting is mandatory for all boards that have only one
579 machine type and must be used to specify the machine type
580 number as it appears in the ARM machine registry
581 (see http://www.arm.linux.org.uk/developer/machines/).
582 Only boards that have multiple machine types supported
583 in a single configuration file and the machine type is
584 runtime discoverable, do not have to use this setting.
586 - vxWorks boot parameters:
588 bootvx constructs a valid bootline using the following
589 environments variables: bootfile, ipaddr, serverip, hostname.
590 It loads the vxWorks image pointed bootfile.
592 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
593 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
594 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
595 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
597 CONFIG_SYS_VXWORKS_ADD_PARAMS
599 Add it at the end of the bootline. E.g "u=username pw=secret"
601 Note: If a "bootargs" environment is defined, it will overwride
602 the defaults discussed just above.
604 - Cache Configuration:
605 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
606 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
607 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
609 - Cache Configuration for ARM:
610 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
612 CONFIG_SYS_PL310_BASE - Physical base address of PL310
613 controller register space
618 Define this if you want support for Amba PrimeCell PL010 UARTs.
622 Define this if you want support for Amba PrimeCell PL011 UARTs.
626 If you have Amba PrimeCell PL011 UARTs, set this variable to
627 the clock speed of the UARTs.
631 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
632 define this to a list of base addresses for each (supported)
633 port. See e.g. include/configs/versatile.h
635 CONFIG_PL011_SERIAL_RLCR
637 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
638 have separate receive and transmit line control registers. Set
639 this variable to initialize the extra register.
641 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
643 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
644 boot loader that has already initialized the UART. Define this
645 variable to flush the UART at init time.
649 Depending on board, define exactly one serial port
650 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
651 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
652 console by defining CONFIG_8xx_CONS_NONE
654 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
655 port routines must be defined elsewhere
656 (i.e. serial_init(), serial_getc(), ...)
659 Enables console device for a color framebuffer. Needs following
660 defines (cf. smiLynxEM, i8042)
661 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
663 VIDEO_HW_RECTFILL graphic chip supports
666 VIDEO_HW_BITBLT graphic chip supports
667 bit-blit (cf. smiLynxEM)
668 VIDEO_VISIBLE_COLS visible pixel columns
670 VIDEO_VISIBLE_ROWS visible pixel rows
671 VIDEO_PIXEL_SIZE bytes per pixel
672 VIDEO_DATA_FORMAT graphic data format
673 (0-5, cf. cfb_console.c)
674 VIDEO_FB_ADRS framebuffer address
675 VIDEO_KBD_INIT_FCT keyboard int fct
676 (i.e. i8042_kbd_init())
677 VIDEO_TSTC_FCT test char fct
679 VIDEO_GETC_FCT get char fct
681 CONFIG_CONSOLE_CURSOR cursor drawing on/off
682 (requires blink timer
684 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
685 CONFIG_CONSOLE_TIME display time/date info in
687 (requires CONFIG_CMD_DATE)
688 CONFIG_VIDEO_LOGO display Linux logo in
690 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
691 linux_logo.h for logo.
692 Requires CONFIG_VIDEO_LOGO
693 CONFIG_CONSOLE_EXTRA_INFO
694 additional board info beside
697 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
698 a limited number of ANSI escape sequences (cursor control,
699 erase functions and limited graphics rendition control).
701 When CONFIG_CFB_CONSOLE is defined, video console is
702 default i/o. Serial console can be forced with
703 environment 'console=serial'.
705 When CONFIG_SILENT_CONSOLE is defined, all console
706 messages (by U-Boot and Linux!) can be silenced with
707 the "silent" environment variable. See
708 doc/README.silent for more information.
711 CONFIG_BAUDRATE - in bps
712 Select one of the baudrates listed in
713 CONFIG_SYS_BAUDRATE_TABLE, see below.
714 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
716 - Console Rx buffer length
717 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
718 the maximum receive buffer length for the SMC.
719 This option is actual only for 82xx and 8xx possible.
720 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
721 must be defined, to setup the maximum idle timeout for
724 - Pre-Console Buffer:
725 Prior to the console being initialised (i.e. serial UART
726 initialised etc) all console output is silently discarded.
727 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
728 buffer any console messages prior to the console being
729 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
730 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
731 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
732 bytes are output before the console is initialised, the
733 earlier bytes are discarded.
735 'Sane' compilers will generate smaller code if
736 CONFIG_PRE_CON_BUF_SZ is a power of 2
738 - Safe printf() functions
739 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
740 the printf() functions. These are defined in
741 include/vsprintf.h and include snprintf(), vsnprintf() and
742 so on. Code size increase is approximately 300-500 bytes.
743 If this option is not given then these functions will
744 silently discard their buffer size argument - this means
745 you are not getting any overflow checking in this case.
747 - Boot Delay: CONFIG_BOOTDELAY - in seconds
748 Delay before automatically booting the default image;
749 set to -1 to disable autoboot.
750 set to -2 to autoboot with no delay and not check for abort
751 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
753 See doc/README.autoboot for these options that
754 work with CONFIG_BOOTDELAY. None are required.
755 CONFIG_BOOT_RETRY_TIME
756 CONFIG_BOOT_RETRY_MIN
757 CONFIG_AUTOBOOT_KEYED
758 CONFIG_AUTOBOOT_PROMPT
759 CONFIG_AUTOBOOT_DELAY_STR
760 CONFIG_AUTOBOOT_STOP_STR
761 CONFIG_AUTOBOOT_DELAY_STR2
762 CONFIG_AUTOBOOT_STOP_STR2
763 CONFIG_ZERO_BOOTDELAY_CHECK
764 CONFIG_RESET_TO_RETRY
768 Only needed when CONFIG_BOOTDELAY is enabled;
769 define a command string that is automatically executed
770 when no character is read on the console interface
771 within "Boot Delay" after reset.
774 This can be used to pass arguments to the bootm
775 command. The value of CONFIG_BOOTARGS goes into the
776 environment value "bootargs".
778 CONFIG_RAMBOOT and CONFIG_NFSBOOT
779 The value of these goes into the environment as
780 "ramboot" and "nfsboot" respectively, and can be used
781 as a convenience, when switching between booting from
787 When this option is #defined, the existence of the
788 environment variable "preboot" will be checked
789 immediately before starting the CONFIG_BOOTDELAY
790 countdown and/or running the auto-boot command resp.
791 entering interactive mode.
793 This feature is especially useful when "preboot" is
794 automatically generated or modified. For an example
795 see the LWMON board specific code: here "preboot" is
796 modified when the user holds down a certain
797 combination of keys on the (special) keyboard when
800 - Serial Download Echo Mode:
802 If defined to 1, all characters received during a
803 serial download (using the "loads" command) are
804 echoed back. This might be needed by some terminal
805 emulations (like "cu"), but may as well just take
806 time on others. This setting #define's the initial
807 value of the "loads_echo" environment variable.
809 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
811 Select one of the baudrates listed in
812 CONFIG_SYS_BAUDRATE_TABLE, see below.
815 Monitor commands can be included or excluded
816 from the build by using the #include files
817 <config_cmd_all.h> and #undef'ing unwanted
818 commands, or using <config_cmd_default.h>
819 and augmenting with additional #define's
822 The default command configuration includes all commands
823 except those marked below with a "*".
825 CONFIG_CMD_ASKENV * ask for env variable
826 CONFIG_CMD_BDI bdinfo
827 CONFIG_CMD_BEDBUG * Include BedBug Debugger
828 CONFIG_CMD_BMP * BMP support
829 CONFIG_CMD_BSP * Board specific commands
830 CONFIG_CMD_BOOTD bootd
831 CONFIG_CMD_CACHE * icache, dcache
832 CONFIG_CMD_CONSOLE coninfo
833 CONFIG_CMD_CRC32 * crc32
834 CONFIG_CMD_DATE * support for RTC, date/time...
835 CONFIG_CMD_DHCP * DHCP support
836 CONFIG_CMD_DIAG * Diagnostics
837 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
838 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
839 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
840 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
841 CONFIG_CMD_DTT * Digital Therm and Thermostat
842 CONFIG_CMD_ECHO echo arguments
843 CONFIG_CMD_EDITENV edit env variable
844 CONFIG_CMD_EEPROM * EEPROM read/write support
845 CONFIG_CMD_ELF * bootelf, bootvx
846 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
847 CONFIG_CMD_ENV_FLAGS * display details about env flags
848 CONFIG_CMD_EXPORTENV * export the environment
849 CONFIG_CMD_EXT2 * ext2 command support
850 CONFIG_CMD_EXT4 * ext4 command support
851 CONFIG_CMD_SAVEENV saveenv
852 CONFIG_CMD_FDC * Floppy Disk Support
853 CONFIG_CMD_FAT * FAT command support
854 CONFIG_CMD_FDOS * Dos diskette Support
855 CONFIG_CMD_FLASH flinfo, erase, protect
856 CONFIG_CMD_FPGA FPGA device initialization support
857 CONFIG_CMD_FUSE * Device fuse support
858 CONFIG_CMD_GETTIME * Get time since boot
859 CONFIG_CMD_GO * the 'go' command (exec code)
860 CONFIG_CMD_GREPENV * search environment
861 CONFIG_CMD_HASH * calculate hash / digest
862 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
863 CONFIG_CMD_I2C * I2C serial bus support
864 CONFIG_CMD_IDE * IDE harddisk support
865 CONFIG_CMD_IMI iminfo
866 CONFIG_CMD_IMLS List all images found in NOR flash
867 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
868 CONFIG_CMD_IMMAP * IMMR dump support
869 CONFIG_CMD_IMPORTENV * import an environment
870 CONFIG_CMD_INI * import data from an ini file into the env
871 CONFIG_CMD_IRQ * irqinfo
872 CONFIG_CMD_ITEST Integer/string test of 2 values
873 CONFIG_CMD_JFFS2 * JFFS2 Support
874 CONFIG_CMD_KGDB * kgdb
875 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
876 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
878 CONFIG_CMD_LOADB loadb
879 CONFIG_CMD_LOADS loads
880 CONFIG_CMD_MD5SUM * print md5 message digest
881 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
882 CONFIG_CMD_MEMINFO * Display detailed memory information
883 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
885 CONFIG_CMD_MEMTEST * mtest
886 CONFIG_CMD_MISC Misc functions like sleep etc
887 CONFIG_CMD_MMC * MMC memory mapped support
888 CONFIG_CMD_MII * MII utility commands
889 CONFIG_CMD_MTDPARTS * MTD partition support
890 CONFIG_CMD_NAND * NAND support
891 CONFIG_CMD_NET bootp, tftpboot, rarpboot
892 CONFIG_CMD_NFS NFS support
893 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
894 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
895 CONFIG_CMD_PCI * pciinfo
896 CONFIG_CMD_PCMCIA * PCMCIA support
897 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
899 CONFIG_CMD_PORTIO * Port I/O
900 CONFIG_CMD_READ * Read raw data from partition
901 CONFIG_CMD_REGINFO * Register dump
902 CONFIG_CMD_RUN run command in env variable
903 CONFIG_CMD_SANDBOX * sb command to access sandbox features
904 CONFIG_CMD_SAVES * save S record dump
905 CONFIG_CMD_SCSI * SCSI Support
906 CONFIG_CMD_SDRAM * print SDRAM configuration information
907 (requires CONFIG_CMD_I2C)
908 CONFIG_CMD_SETGETDCR Support for DCR Register access
910 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
911 CONFIG_CMD_SHA1SUM * print sha1 memory digest
912 (requires CONFIG_CMD_MEMORY)
913 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
914 CONFIG_CMD_SOURCE "source" command Support
915 CONFIG_CMD_SPI * SPI serial bus support
916 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
917 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
918 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
919 CONFIG_CMD_TIMER * access to the system tick timer
920 CONFIG_CMD_USB * USB support
921 CONFIG_CMD_CDP * Cisco Discover Protocol support
922 CONFIG_CMD_MFSL * Microblaze FSL support
923 CONFIG_CMD_XIMG Load part of Multi Image
926 EXAMPLE: If you want all functions except of network
927 support you can write:
929 #include "config_cmd_all.h"
930 #undef CONFIG_CMD_NET
933 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
935 Note: Don't enable the "icache" and "dcache" commands
936 (configuration option CONFIG_CMD_CACHE) unless you know
937 what you (and your U-Boot users) are doing. Data
938 cache cannot be enabled on systems like the 8xx or
939 8260 (where accesses to the IMMR region must be
940 uncached), and it cannot be disabled on all other
941 systems where we (mis-) use the data cache to hold an
942 initial stack and some data.
945 XXX - this list needs to get updated!
947 - Regular expression support:
949 If this variable is defined, U-Boot is linked against
950 the SLRE (Super Light Regular Expression) library,
951 which adds regex support to some commands, as for
952 example "env grep" and "setexpr".
956 If this variable is defined, U-Boot will use a device tree
957 to configure its devices, instead of relying on statically
958 compiled #defines in the board file. This option is
959 experimental and only available on a few boards. The device
960 tree is available in the global data as gd->fdt_blob.
962 U-Boot needs to get its device tree from somewhere. This can
963 be done using one of the two options below:
966 If this variable is defined, U-Boot will embed a device tree
967 binary in its image. This device tree file should be in the
968 board directory and called <soc>-<board>.dts. The binary file
969 is then picked up in board_init_f() and made available through
970 the global data structure as gd->blob.
973 If this variable is defined, U-Boot will build a device tree
974 binary. It will be called u-boot.dtb. Architecture-specific
975 code will locate it at run-time. Generally this works by:
977 cat u-boot.bin u-boot.dtb >image.bin
979 and in fact, U-Boot does this for you, creating a file called
980 u-boot-dtb.bin which is useful in the common case. You can
981 still use the individual files if you need something more
986 If this variable is defined, it enables watchdog
987 support for the SoC. There must be support in the SoC
988 specific code for a watchdog. For the 8xx and 8260
989 CPUs, the SIU Watchdog feature is enabled in the SYPCR
990 register. When supported for a specific SoC is
991 available, then no further board specific code should
995 When using a watchdog circuitry external to the used
996 SoC, then define this variable and provide board
997 specific code for the "hw_watchdog_reset" function.
1000 CONFIG_VERSION_VARIABLE
1001 If this variable is defined, an environment variable
1002 named "ver" is created by U-Boot showing the U-Boot
1003 version as printed by the "version" command.
1004 Any change to this variable will be reverted at the
1009 When CONFIG_CMD_DATE is selected, the type of the RTC
1010 has to be selected, too. Define exactly one of the
1013 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1014 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1015 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1016 CONFIG_RTC_MC146818 - use MC146818 RTC
1017 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1018 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1019 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1020 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1021 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1022 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1023 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1024 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1027 Note that if the RTC uses I2C, then the I2C interface
1028 must also be configured. See I2C Support, below.
1031 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1032 CONFIG_PCA953X_INFO - enable pca953x info command
1034 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1035 chip-ngpio pairs that tell the PCA953X driver the number of
1036 pins supported by a particular chip.
1038 Note that if the GPIO device uses I2C, then the I2C interface
1039 must also be configured. See I2C Support, below.
1041 - Timestamp Support:
1043 When CONFIG_TIMESTAMP is selected, the timestamp
1044 (date and time) of an image is printed by image
1045 commands like bootm or iminfo. This option is
1046 automatically enabled when you select CONFIG_CMD_DATE .
1048 - Partition Labels (disklabels) Supported:
1049 Zero or more of the following:
1050 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1051 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1052 Intel architecture, USB sticks, etc.
1053 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1054 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1055 bootloader. Note 2TB partition limit; see
1057 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1059 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1060 CONFIG_CMD_SCSI) you must configure support for at
1061 least one non-MTD partition type as well.
1064 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1065 board configurations files but used nowhere!
1067 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1068 be performed by calling the function
1069 ide_set_reset(int reset)
1070 which has to be defined in a board specific file
1075 Set this to enable ATAPI support.
1080 Set this to enable support for disks larger than 137GB
1081 Also look at CONFIG_SYS_64BIT_LBA.
1082 Whithout these , LBA48 support uses 32bit variables and will 'only'
1083 support disks up to 2.1TB.
1085 CONFIG_SYS_64BIT_LBA:
1086 When enabled, makes the IDE subsystem use 64bit sector addresses.
1090 At the moment only there is only support for the
1091 SYM53C8XX SCSI controller; define
1092 CONFIG_SCSI_SYM53C8XX to enable it.
1094 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1095 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1096 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1097 maximum numbers of LUNs, SCSI ID's and target
1099 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1101 The environment variable 'scsidevs' is set to the number of
1102 SCSI devices found during the last scan.
1104 - NETWORK Support (PCI):
1106 Support for Intel 8254x/8257x gigabit chips.
1109 Utility code for direct access to the SPI bus on Intel 8257x.
1110 This does not do anything useful unless you set at least one
1111 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1113 CONFIG_E1000_SPI_GENERIC
1114 Allow generic access to the SPI bus on the Intel 8257x, for
1115 example with the "sspi" command.
1118 Management command for E1000 devices. When used on devices
1119 with SPI support you can reprogram the EEPROM from U-Boot.
1121 CONFIG_E1000_FALLBACK_MAC
1122 default MAC for empty EEPROM after production.
1125 Support for Intel 82557/82559/82559ER chips.
1126 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1127 write routine for first time initialisation.
1130 Support for Digital 2114x chips.
1131 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1132 modem chip initialisation (KS8761/QS6611).
1135 Support for National dp83815 chips.
1138 Support for National dp8382[01] gigabit chips.
1140 - NETWORK Support (other):
1142 CONFIG_DRIVER_AT91EMAC
1143 Support for AT91RM9200 EMAC.
1146 Define this to use reduced MII inteface
1148 CONFIG_DRIVER_AT91EMAC_QUIET
1149 If this defined, the driver is quiet.
1150 The driver doen't show link status messages.
1152 CONFIG_CALXEDA_XGMAC
1153 Support for the Calxeda XGMAC device
1156 Support for SMSC's LAN91C96 chips.
1158 CONFIG_LAN91C96_BASE
1159 Define this to hold the physical address
1160 of the LAN91C96's I/O space
1162 CONFIG_LAN91C96_USE_32_BIT
1163 Define this to enable 32 bit addressing
1166 Support for SMSC's LAN91C111 chip
1168 CONFIG_SMC91111_BASE
1169 Define this to hold the physical address
1170 of the device (I/O space)
1172 CONFIG_SMC_USE_32_BIT
1173 Define this if data bus is 32 bits
1175 CONFIG_SMC_USE_IOFUNCS
1176 Define this to use i/o functions instead of macros
1177 (some hardware wont work with macros)
1179 CONFIG_DRIVER_TI_EMAC
1180 Support for davinci emac
1182 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1183 Define this if you have more then 3 PHYs.
1186 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1188 CONFIG_FTGMAC100_EGIGA
1189 Define this to use GE link update with gigabit PHY.
1190 Define this if FTGMAC100 is connected to gigabit PHY.
1191 If your system has 10/100 PHY only, it might not occur
1192 wrong behavior. Because PHY usually return timeout or
1193 useless data when polling gigabit status and gigabit
1194 control registers. This behavior won't affect the
1195 correctnessof 10/100 link speed update.
1198 Support for SMSC's LAN911x and LAN921x chips
1201 Define this to hold the physical address
1202 of the device (I/O space)
1204 CONFIG_SMC911X_32_BIT
1205 Define this if data bus is 32 bits
1207 CONFIG_SMC911X_16_BIT
1208 Define this if data bus is 16 bits. If your processor
1209 automatically converts one 32 bit word to two 16 bit
1210 words you may also try CONFIG_SMC911X_32_BIT.
1213 Support for Renesas on-chip Ethernet controller
1215 CONFIG_SH_ETHER_USE_PORT
1216 Define the number of ports to be used
1218 CONFIG_SH_ETHER_PHY_ADDR
1219 Define the ETH PHY's address
1221 CONFIG_SH_ETHER_CACHE_WRITEBACK
1222 If this option is set, the driver enables cache flush.
1226 Support TPM devices.
1229 Support for i2c bus TPM devices. Only one device
1230 per system is supported at this time.
1232 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1233 Define the the i2c bus number for the TPM device
1235 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1236 Define the TPM's address on the i2c bus
1238 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1239 Define the burst count bytes upper limit
1242 Support for generic parallel port TPM devices. Only one device
1243 per system is supported at this time.
1245 CONFIG_TPM_TIS_BASE_ADDRESS
1246 Base address where the generic TPM device is mapped
1247 to. Contemporary x86 systems usually map it at
1251 At the moment only the UHCI host controller is
1252 supported (PIP405, MIP405, MPC5200); define
1253 CONFIG_USB_UHCI to enable it.
1254 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1255 and define CONFIG_USB_STORAGE to enable the USB
1258 Supported are USB Keyboards and USB Floppy drives
1260 MPC5200 USB requires additional defines:
1262 for 528 MHz Clock: 0x0001bbbb
1266 for differential drivers: 0x00001000
1267 for single ended drivers: 0x00005000
1268 for differential drivers on PSC3: 0x00000100
1269 for single ended drivers on PSC3: 0x00004100
1270 CONFIG_SYS_USB_EVENT_POLL
1271 May be defined to allow interrupt polling
1272 instead of using asynchronous interrupts
1274 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1275 txfilltuning field in the EHCI controller on reset.
1277 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1278 interval for usb hub power-on delay.(minimum 100msec)
1281 Define the below if you wish to use the USB console.
1282 Once firmware is rebuilt from a serial console issue the
1283 command "setenv stdin usbtty; setenv stdout usbtty" and
1284 attach your USB cable. The Unix command "dmesg" should print
1285 it has found a new device. The environment variable usbtty
1286 can be set to gserial or cdc_acm to enable your device to
1287 appear to a USB host as a Linux gserial device or a
1288 Common Device Class Abstract Control Model serial device.
1289 If you select usbtty = gserial you should be able to enumerate
1291 # modprobe usbserial vendor=0xVendorID product=0xProductID
1292 else if using cdc_acm, simply setting the environment
1293 variable usbtty to be cdc_acm should suffice. The following
1294 might be defined in YourBoardName.h
1297 Define this to build a UDC device
1300 Define this to have a tty type of device available to
1301 talk to the UDC device
1304 Define this to enable the high speed support for usb
1305 device and usbtty. If this feature is enabled, a routine
1306 int is_usbd_high_speed(void)
1307 also needs to be defined by the driver to dynamically poll
1308 whether the enumeration has succeded at high speed or full
1311 CONFIG_SYS_CONSOLE_IS_IN_ENV
1312 Define this if you want stdin, stdout &/or stderr to
1316 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1317 Derive USB clock from external clock "blah"
1318 - CONFIG_SYS_USB_EXTC_CLK 0x02
1320 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1321 Derive USB clock from brgclk
1322 - CONFIG_SYS_USB_BRG_CLK 0x04
1324 If you have a USB-IF assigned VendorID then you may wish to
1325 define your own vendor specific values either in BoardName.h
1326 or directly in usbd_vendor_info.h. If you don't define
1327 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1328 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1329 should pretend to be a Linux device to it's target host.
1331 CONFIG_USBD_MANUFACTURER
1332 Define this string as the name of your company for
1333 - CONFIG_USBD_MANUFACTURER "my company"
1335 CONFIG_USBD_PRODUCT_NAME
1336 Define this string as the name of your product
1337 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1339 CONFIG_USBD_VENDORID
1340 Define this as your assigned Vendor ID from the USB
1341 Implementors Forum. This *must* be a genuine Vendor ID
1342 to avoid polluting the USB namespace.
1343 - CONFIG_USBD_VENDORID 0xFFFF
1345 CONFIG_USBD_PRODUCTID
1346 Define this as the unique Product ID
1348 - CONFIG_USBD_PRODUCTID 0xFFFF
1350 - ULPI Layer Support:
1351 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1352 the generic ULPI layer. The generic layer accesses the ULPI PHY
1353 via the platform viewport, so you need both the genric layer and
1354 the viewport enabled. Currently only Chipidea/ARC based
1355 viewport is supported.
1356 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1357 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1358 If your ULPI phy needs a different reference clock than the
1359 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1360 the appropriate value in Hz.
1363 The MMC controller on the Intel PXA is supported. To
1364 enable this define CONFIG_MMC. The MMC can be
1365 accessed from the boot prompt by mapping the device
1366 to physical memory similar to flash. Command line is
1367 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1368 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1371 Support for Renesas on-chip MMCIF controller
1373 CONFIG_SH_MMCIF_ADDR
1374 Define the base address of MMCIF registers
1377 Define the clock frequency for MMCIF
1379 - USB Device Firmware Update (DFU) class support:
1381 This enables the USB portion of the DFU USB class
1384 This enables the command "dfu" which is used to have
1385 U-Boot create a DFU class device via USB. This command
1386 requires that the "dfu_alt_info" environment variable be
1387 set and define the alt settings to expose to the host.
1390 This enables support for exposing (e)MMC devices via DFU.
1393 This enables support for exposing NAND devices via DFU.
1395 CONFIG_SYS_DFU_MAX_FILE_SIZE
1396 When updating files rather than the raw storage device,
1397 we use a static buffer to copy the file into and then write
1398 the buffer once we've been given the whole file. Define
1399 this to the maximum filesize (in bytes) for the buffer.
1400 Default is 4 MiB if undefined.
1402 - Journaling Flash filesystem support:
1403 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1404 CONFIG_JFFS2_NAND_DEV
1405 Define these for a default partition on a NAND device
1407 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1408 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1409 Define these for a default partition on a NOR device
1411 CONFIG_SYS_JFFS_CUSTOM_PART
1412 Define this to create an own partition. You have to provide a
1413 function struct part_info* jffs2_part_info(int part_num)
1415 If you define only one JFFS2 partition you may also want to
1416 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1417 to disable the command chpart. This is the default when you
1418 have not defined a custom partition
1420 - FAT(File Allocation Table) filesystem write function support:
1423 Define this to enable support for saving memory data as a
1424 file in FAT formatted partition.
1426 This will also enable the command "fatwrite" enabling the
1427 user to write files to FAT.
1429 CBFS (Coreboot Filesystem) support
1432 Define this to enable support for reading from a Coreboot
1433 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1439 Define this to enable standard (PC-Style) keyboard
1443 Standard PC keyboard driver with US (is default) and
1444 GERMAN key layout (switch via environment 'keymap=de') support.
1445 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1446 for cfb_console. Supports cursor blinking.
1449 Enables a Chrome OS keyboard using the CROS_EC interface.
1450 This uses CROS_EC to communicate with a second microcontroller
1451 which provides key scans on request.
1456 Define this to enable video support (for output to
1459 CONFIG_VIDEO_CT69000
1461 Enable Chips & Technologies 69000 Video chip
1463 CONFIG_VIDEO_SMI_LYNXEM
1464 Enable Silicon Motion SMI 712/710/810 Video chip. The
1465 video output is selected via environment 'videoout'
1466 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1469 For the CT69000 and SMI_LYNXEM drivers, videomode is
1470 selected via environment 'videomode'. Two different ways
1472 - "videomode=num" 'num' is a standard LiLo mode numbers.
1473 Following standard modes are supported (* is default):
1475 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1476 -------------+---------------------------------------------
1477 8 bits | 0x301* 0x303 0x305 0x161 0x307
1478 15 bits | 0x310 0x313 0x316 0x162 0x319
1479 16 bits | 0x311 0x314 0x317 0x163 0x31A
1480 24 bits | 0x312 0x315 0x318 ? 0x31B
1481 -------------+---------------------------------------------
1482 (i.e. setenv videomode 317; saveenv; reset;)
1484 - "videomode=bootargs" all the video parameters are parsed
1485 from the bootargs. (See drivers/video/videomodes.c)
1488 CONFIG_VIDEO_SED13806
1489 Enable Epson SED13806 driver. This driver supports 8bpp
1490 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1491 or CONFIG_VIDEO_SED13806_16BPP
1494 Enable the Freescale DIU video driver. Reference boards for
1495 SOCs that have a DIU should define this macro to enable DIU
1496 support, and should also define these other macros:
1502 CONFIG_VIDEO_SW_CURSOR
1503 CONFIG_VGA_AS_SINGLE_DEVICE
1505 CONFIG_VIDEO_BMP_LOGO
1507 The DIU driver will look for the 'video-mode' environment
1508 variable, and if defined, enable the DIU as a console during
1509 boot. See the documentation file README.video for a
1510 description of this variable.
1514 Enable the VGA video / BIOS for x86. The alternative if you
1515 are using coreboot is to use the coreboot frame buffer
1522 Define this to enable a custom keyboard support.
1523 This simply calls drv_keyboard_init() which must be
1524 defined in your board-specific files.
1525 The only board using this so far is RBC823.
1527 - LCD Support: CONFIG_LCD
1529 Define this to enable LCD support (for output to LCD
1530 display); also select one of the supported displays
1531 by defining one of these:
1535 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1537 CONFIG_NEC_NL6448AC33:
1539 NEC NL6448AC33-18. Active, color, single scan.
1541 CONFIG_NEC_NL6448BC20
1543 NEC NL6448BC20-08. 6.5", 640x480.
1544 Active, color, single scan.
1546 CONFIG_NEC_NL6448BC33_54
1548 NEC NL6448BC33-54. 10.4", 640x480.
1549 Active, color, single scan.
1553 Sharp 320x240. Active, color, single scan.
1554 It isn't 16x9, and I am not sure what it is.
1556 CONFIG_SHARP_LQ64D341
1558 Sharp LQ64D341 display, 640x480.
1559 Active, color, single scan.
1563 HLD1045 display, 640x480.
1564 Active, color, single scan.
1568 Optrex CBL50840-2 NF-FW 99 22 M5
1570 Hitachi LMG6912RPFC-00T
1574 320x240. Black & white.
1576 Normally display is black on white background; define
1577 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1579 CONFIG_LCD_ALIGNMENT
1581 Normally the LCD is page-aligned (tyically 4KB). If this is
1582 defined then the LCD will be aligned to this value instead.
1583 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1584 here, since it is cheaper to change data cache settings on
1585 a per-section basis.
1587 CONFIG_CONSOLE_SCROLL_LINES
1589 When the console need to be scrolled, this is the number of
1590 lines to scroll by. It defaults to 1. Increasing this makes
1591 the console jump but can help speed up operation when scrolling
1596 Support drawing of RLE8-compressed bitmaps on the LCD.
1600 Enables an 'i2c edid' command which can read EDID
1601 information over I2C from an attached LCD display.
1603 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1605 If this option is set, the environment is checked for
1606 a variable "splashimage". If found, the usual display
1607 of logo, copyright and system information on the LCD
1608 is suppressed and the BMP image at the address
1609 specified in "splashimage" is loaded instead. The
1610 console is redirected to the "nulldev", too. This
1611 allows for a "silent" boot where a splash screen is
1612 loaded very quickly after power-on.
1614 CONFIG_SPLASHIMAGE_GUARD
1616 If this option is set, then U-Boot will prevent the environment
1617 variable "splashimage" from being set to a problematic address
1618 (see README.displaying-bmps and README.arm-unaligned-accesses).
1619 This option is useful for targets where, due to alignment
1620 restrictions, an improperly aligned BMP image will cause a data
1621 abort. If you think you will not have problems with unaligned
1622 accesses (for example because your toolchain prevents them)
1623 there is no need to set this option.
1625 CONFIG_SPLASH_SCREEN_ALIGN
1627 If this option is set the splash image can be freely positioned
1628 on the screen. Environment variable "splashpos" specifies the
1629 position as "x,y". If a positive number is given it is used as
1630 number of pixel from left/top. If a negative number is given it
1631 is used as number of pixel from right/bottom. You can also
1632 specify 'm' for centering the image.
1635 setenv splashpos m,m
1636 => image at center of screen
1638 setenv splashpos 30,20
1639 => image at x = 30 and y = 20
1641 setenv splashpos -10,m
1642 => vertically centered image
1643 at x = dspWidth - bmpWidth - 9
1645 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1647 If this option is set, additionally to standard BMP
1648 images, gzipped BMP images can be displayed via the
1649 splashscreen support or the bmp command.
1651 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1653 If this option is set, 8-bit RLE compressed BMP images
1654 can be displayed via the splashscreen support or the
1657 - Do compresssing for memory range:
1660 If this option is set, it would use zlib deflate method
1661 to compress the specified memory at its best effort.
1663 - Compression support:
1666 If this option is set, support for bzip2 compressed
1667 images is included. If not, only uncompressed and gzip
1668 compressed images are supported.
1670 NOTE: the bzip2 algorithm requires a lot of RAM, so
1671 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1676 If this option is set, support for lzma compressed
1679 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1680 requires an amount of dynamic memory that is given by the
1683 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1685 Where lc and lp stand for, respectively, Literal context bits
1686 and Literal pos bits.
1688 This value is upper-bounded by 14MB in the worst case. Anyway,
1689 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1690 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1691 a very small buffer.
1693 Use the lzmainfo tool to determinate the lc and lp values and
1694 then calculate the amount of needed dynamic memory (ensuring
1695 the appropriate CONFIG_SYS_MALLOC_LEN value).
1700 The address of PHY on MII bus.
1702 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1704 The clock frequency of the MII bus
1708 If this option is set, support for speed/duplex
1709 detection of gigabit PHY is included.
1711 CONFIG_PHY_RESET_DELAY
1713 Some PHY like Intel LXT971A need extra delay after
1714 reset before any MII register access is possible.
1715 For such PHY, set this option to the usec delay
1716 required. (minimum 300usec for LXT971A)
1718 CONFIG_PHY_CMD_DELAY (ppc4xx)
1720 Some PHY like Intel LXT971A need extra delay after
1721 command issued before MII status register can be read
1731 Define a default value for Ethernet address to use
1732 for the respective Ethernet interface, in case this
1733 is not determined automatically.
1738 Define a default value for the IP address to use for
1739 the default Ethernet interface, in case this is not
1740 determined through e.g. bootp.
1741 (Environment variable "ipaddr")
1743 - Server IP address:
1746 Defines a default value for the IP address of a TFTP
1747 server to contact when using the "tftboot" command.
1748 (Environment variable "serverip")
1750 CONFIG_KEEP_SERVERADDR
1752 Keeps the server's MAC address, in the env 'serveraddr'
1753 for passing to bootargs (like Linux's netconsole option)
1755 - Gateway IP address:
1758 Defines a default value for the IP address of the
1759 default router where packets to other networks are
1761 (Environment variable "gatewayip")
1766 Defines a default value for the subnet mask (or
1767 routing prefix) which is used to determine if an IP
1768 address belongs to the local subnet or needs to be
1769 forwarded through a router.
1770 (Environment variable "netmask")
1772 - Multicast TFTP Mode:
1775 Defines whether you want to support multicast TFTP as per
1776 rfc-2090; for example to work with atftp. Lets lots of targets
1777 tftp down the same boot image concurrently. Note: the Ethernet
1778 driver in use must provide a function: mcast() to join/leave a
1781 - BOOTP Recovery Mode:
1782 CONFIG_BOOTP_RANDOM_DELAY
1784 If you have many targets in a network that try to
1785 boot using BOOTP, you may want to avoid that all
1786 systems send out BOOTP requests at precisely the same
1787 moment (which would happen for instance at recovery
1788 from a power failure, when all systems will try to
1789 boot, thus flooding the BOOTP server. Defining
1790 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1791 inserted before sending out BOOTP requests. The
1792 following delays are inserted then:
1794 1st BOOTP request: delay 0 ... 1 sec
1795 2nd BOOTP request: delay 0 ... 2 sec
1796 3rd BOOTP request: delay 0 ... 4 sec
1798 BOOTP requests: delay 0 ... 8 sec
1800 - DHCP Advanced Options:
1801 You can fine tune the DHCP functionality by defining
1802 CONFIG_BOOTP_* symbols:
1804 CONFIG_BOOTP_SUBNETMASK
1805 CONFIG_BOOTP_GATEWAY
1806 CONFIG_BOOTP_HOSTNAME
1807 CONFIG_BOOTP_NISDOMAIN
1808 CONFIG_BOOTP_BOOTPATH
1809 CONFIG_BOOTP_BOOTFILESIZE
1812 CONFIG_BOOTP_SEND_HOSTNAME
1813 CONFIG_BOOTP_NTPSERVER
1814 CONFIG_BOOTP_TIMEOFFSET
1815 CONFIG_BOOTP_VENDOREX
1816 CONFIG_BOOTP_MAY_FAIL
1818 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1819 environment variable, not the BOOTP server.
1821 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1822 after the configured retry count, the call will fail
1823 instead of starting over. This can be used to fail over
1824 to Link-local IP address configuration if the DHCP server
1827 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1828 serverip from a DHCP server, it is possible that more
1829 than one DNS serverip is offered to the client.
1830 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1831 serverip will be stored in the additional environment
1832 variable "dnsip2". The first DNS serverip is always
1833 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1836 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1837 to do a dynamic update of a DNS server. To do this, they
1838 need the hostname of the DHCP requester.
1839 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1840 of the "hostname" environment variable is passed as
1841 option 12 to the DHCP server.
1843 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1845 A 32bit value in microseconds for a delay between
1846 receiving a "DHCP Offer" and sending the "DHCP Request".
1847 This fixes a problem with certain DHCP servers that don't
1848 respond 100% of the time to a "DHCP request". E.g. On an
1849 AT91RM9200 processor running at 180MHz, this delay needed
1850 to be *at least* 15,000 usec before a Windows Server 2003
1851 DHCP server would reply 100% of the time. I recommend at
1852 least 50,000 usec to be safe. The alternative is to hope
1853 that one of the retries will be successful but note that
1854 the DHCP timeout and retry process takes a longer than
1857 - Link-local IP address negotiation:
1858 Negotiate with other link-local clients on the local network
1859 for an address that doesn't require explicit configuration.
1860 This is especially useful if a DHCP server cannot be guaranteed
1861 to exist in all environments that the device must operate.
1863 See doc/README.link-local for more information.
1866 CONFIG_CDP_DEVICE_ID
1868 The device id used in CDP trigger frames.
1870 CONFIG_CDP_DEVICE_ID_PREFIX
1872 A two character string which is prefixed to the MAC address
1877 A printf format string which contains the ascii name of
1878 the port. Normally is set to "eth%d" which sets
1879 eth0 for the first Ethernet, eth1 for the second etc.
1881 CONFIG_CDP_CAPABILITIES
1883 A 32bit integer which indicates the device capabilities;
1884 0x00000010 for a normal host which does not forwards.
1888 An ascii string containing the version of the software.
1892 An ascii string containing the name of the platform.
1896 A 32bit integer sent on the trigger.
1898 CONFIG_CDP_POWER_CONSUMPTION
1900 A 16bit integer containing the power consumption of the
1901 device in .1 of milliwatts.
1903 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1905 A byte containing the id of the VLAN.
1907 - Status LED: CONFIG_STATUS_LED
1909 Several configurations allow to display the current
1910 status using a LED. For instance, the LED will blink
1911 fast while running U-Boot code, stop blinking as
1912 soon as a reply to a BOOTP request was received, and
1913 start blinking slow once the Linux kernel is running
1914 (supported by a status LED driver in the Linux
1915 kernel). Defining CONFIG_STATUS_LED enables this
1918 - CAN Support: CONFIG_CAN_DRIVER
1920 Defining CONFIG_CAN_DRIVER enables CAN driver support
1921 on those systems that support this (optional)
1922 feature, like the TQM8xxL modules.
1924 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1926 These enable I2C serial bus commands. Defining either of
1927 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1928 include the appropriate I2C driver for the selected CPU.
1930 This will allow you to use i2c commands at the u-boot
1931 command line (as long as you set CONFIG_CMD_I2C in
1932 CONFIG_COMMANDS) and communicate with i2c based realtime
1933 clock chips. See common/cmd_i2c.c for a description of the
1934 command line interface.
1936 CONFIG_HARD_I2C selects a hardware I2C controller.
1938 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1939 bit-banging) driver instead of CPM or similar hardware
1942 There are several other quantities that must also be
1943 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1945 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1946 to be the frequency (in Hz) at which you wish your i2c bus
1947 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1948 the CPU's i2c node address).
1950 Now, the u-boot i2c code for the mpc8xx
1951 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1952 and so its address should therefore be cleared to 0 (See,
1953 eg, MPC823e User's Manual p.16-473). So, set
1954 CONFIG_SYS_I2C_SLAVE to 0.
1956 CONFIG_SYS_I2C_INIT_MPC5XXX
1958 When a board is reset during an i2c bus transfer
1959 chips might think that the current transfer is still
1960 in progress. Reset the slave devices by sending start
1961 commands until the slave device responds.
1963 That's all that's required for CONFIG_HARD_I2C.
1965 If you use the software i2c interface (CONFIG_SOFT_I2C)
1966 then the following macros need to be defined (examples are
1967 from include/configs/lwmon.h):
1971 (Optional). Any commands necessary to enable the I2C
1972 controller or configure ports.
1974 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1978 (Only for MPC8260 CPU). The I/O port to use (the code
1979 assumes both bits are on the same port). Valid values
1980 are 0..3 for ports A..D.
1984 The code necessary to make the I2C data line active
1985 (driven). If the data line is open collector, this
1988 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1992 The code necessary to make the I2C data line tri-stated
1993 (inactive). If the data line is open collector, this
1996 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2000 Code that returns true if the I2C data line is high,
2003 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2007 If <bit> is true, sets the I2C data line high. If it
2008 is false, it clears it (low).
2010 eg: #define I2C_SDA(bit) \
2011 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2012 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2016 If <bit> is true, sets the I2C clock line high. If it
2017 is false, it clears it (low).
2019 eg: #define I2C_SCL(bit) \
2020 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2021 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2025 This delay is invoked four times per clock cycle so this
2026 controls the rate of data transfer. The data rate thus
2027 is 1 / (I2C_DELAY * 4). Often defined to be something
2030 #define I2C_DELAY udelay(2)
2032 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2034 If your arch supports the generic GPIO framework (asm/gpio.h),
2035 then you may alternatively define the two GPIOs that are to be
2036 used as SCL / SDA. Any of the previous I2C_xxx macros will
2037 have GPIO-based defaults assigned to them as appropriate.
2039 You should define these to the GPIO value as given directly to
2040 the generic GPIO functions.
2042 CONFIG_SYS_I2C_INIT_BOARD
2044 When a board is reset during an i2c bus transfer
2045 chips might think that the current transfer is still
2046 in progress. On some boards it is possible to access
2047 the i2c SCLK line directly, either by using the
2048 processor pin as a GPIO or by having a second pin
2049 connected to the bus. If this option is defined a
2050 custom i2c_init_board() routine in boards/xxx/board.c
2051 is run early in the boot sequence.
2053 CONFIG_SYS_I2C_BOARD_LATE_INIT
2055 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2056 defined a custom i2c_board_late_init() routine in
2057 boards/xxx/board.c is run AFTER the operations in i2c_init()
2058 is completed. This callpoint can be used to unreset i2c bus
2059 using CPU i2c controller register accesses for CPUs whose i2c
2060 controller provide such a method. It is called at the end of
2061 i2c_init() to allow i2c_init operations to setup the i2c bus
2062 controller on the CPU (e.g. setting bus speed & slave address).
2064 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2066 This option enables configuration of bi_iic_fast[] flags
2067 in u-boot bd_info structure based on u-boot environment
2068 variable "i2cfast". (see also i2cfast)
2070 CONFIG_I2C_MULTI_BUS
2072 This option allows the use of multiple I2C buses, each of which
2073 must have a controller. At any point in time, only one bus is
2074 active. To switch to a different bus, use the 'i2c dev' command.
2075 Note that bus numbering is zero-based.
2077 CONFIG_SYS_I2C_NOPROBES
2079 This option specifies a list of I2C devices that will be skipped
2080 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2081 is set, specify a list of bus-device pairs. Otherwise, specify
2082 a 1D array of device addresses
2085 #undef CONFIG_I2C_MULTI_BUS
2086 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2088 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2090 #define CONFIG_I2C_MULTI_BUS
2091 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2093 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2095 CONFIG_SYS_SPD_BUS_NUM
2097 If defined, then this indicates the I2C bus number for DDR SPD.
2098 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2100 CONFIG_SYS_RTC_BUS_NUM
2102 If defined, then this indicates the I2C bus number for the RTC.
2103 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2105 CONFIG_SYS_DTT_BUS_NUM
2107 If defined, then this indicates the I2C bus number for the DTT.
2108 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2110 CONFIG_SYS_I2C_DTT_ADDR:
2112 If defined, specifies the I2C address of the DTT device.
2113 If not defined, then U-Boot uses predefined value for
2114 specified DTT device.
2118 Define this option if you want to use Freescale's I2C driver in
2119 drivers/i2c/fsl_i2c.c.
2123 Define this option if you have I2C devices reached over 1 .. n
2124 I2C Muxes like the pca9544a. This option addes a new I2C
2125 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2126 new I2C Bus to the existing I2C Busses. If you select the
2127 new Bus with "i2c dev", u-bbot sends first the commandos for
2128 the muxes to activate this new "bus".
2130 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2134 Adding a new I2C Bus reached over 2 pca9544a muxes
2135 The First mux with address 70 and channel 6
2136 The Second mux with address 71 and channel 4
2138 => i2c bus pca9544a:70:6:pca9544a:71:4
2140 Use the "i2c bus" command without parameter, to get a list
2141 of I2C Busses with muxes:
2144 Busses reached over muxes:
2146 reached over Mux(es):
2149 reached over Mux(es):
2154 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2155 u-boot first sends the command to the mux@70 to enable
2156 channel 6, and then the command to the mux@71 to enable
2159 After that, you can use the "normal" i2c commands as
2160 usual to communicate with your I2C devices behind
2163 This option is actually implemented for the bitbanging
2164 algorithm in common/soft_i2c.c and for the Hardware I2C
2165 Bus on the MPC8260. But it should be not so difficult
2166 to add this option to other architectures.
2168 CONFIG_SOFT_I2C_READ_REPEATED_START
2170 defining this will force the i2c_read() function in
2171 the soft_i2c driver to perform an I2C repeated start
2172 between writing the address pointer and reading the
2173 data. If this define is omitted the default behaviour
2174 of doing a stop-start sequence will be used. Most I2C
2175 devices can use either method, but some require one or
2178 - SPI Support: CONFIG_SPI
2180 Enables SPI driver (so far only tested with
2181 SPI EEPROM, also an instance works with Crystal A/D and
2182 D/As on the SACSng board)
2186 Enables the driver for SPI controller on SuperH. Currently
2187 only SH7757 is supported.
2191 Enables extended (16-bit) SPI EEPROM addressing.
2192 (symmetrical to CONFIG_I2C_X)
2196 Enables a software (bit-bang) SPI driver rather than
2197 using hardware support. This is a general purpose
2198 driver that only requires three general I/O port pins
2199 (two outputs, one input) to function. If this is
2200 defined, the board configuration must define several
2201 SPI configuration items (port pins to use, etc). For
2202 an example, see include/configs/sacsng.h.
2206 Enables a hardware SPI driver for general-purpose reads
2207 and writes. As with CONFIG_SOFT_SPI, the board configuration
2208 must define a list of chip-select function pointers.
2209 Currently supported on some MPC8xxx processors. For an
2210 example, see include/configs/mpc8349emds.h.
2214 Enables the driver for the SPI controllers on i.MX and MXC
2215 SoCs. Currently i.MX31/35/51 are supported.
2217 - FPGA Support: CONFIG_FPGA
2219 Enables FPGA subsystem.
2221 CONFIG_FPGA_<vendor>
2223 Enables support for specific chip vendors.
2226 CONFIG_FPGA_<family>
2228 Enables support for FPGA family.
2229 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2233 Specify the number of FPGA devices to support.
2235 CONFIG_SYS_FPGA_PROG_FEEDBACK
2237 Enable printing of hash marks during FPGA configuration.
2239 CONFIG_SYS_FPGA_CHECK_BUSY
2241 Enable checks on FPGA configuration interface busy
2242 status by the configuration function. This option
2243 will require a board or device specific function to
2248 If defined, a function that provides delays in the FPGA
2249 configuration driver.
2251 CONFIG_SYS_FPGA_CHECK_CTRLC
2252 Allow Control-C to interrupt FPGA configuration
2254 CONFIG_SYS_FPGA_CHECK_ERROR
2256 Check for configuration errors during FPGA bitfile
2257 loading. For example, abort during Virtex II
2258 configuration if the INIT_B line goes low (which
2259 indicated a CRC error).
2261 CONFIG_SYS_FPGA_WAIT_INIT
2263 Maximum time to wait for the INIT_B line to deassert
2264 after PROB_B has been deasserted during a Virtex II
2265 FPGA configuration sequence. The default time is 500
2268 CONFIG_SYS_FPGA_WAIT_BUSY
2270 Maximum time to wait for BUSY to deassert during
2271 Virtex II FPGA configuration. The default is 5 ms.
2273 CONFIG_SYS_FPGA_WAIT_CONFIG
2275 Time to wait after FPGA configuration. The default is
2278 - Configuration Management:
2281 If defined, this string will be added to the U-Boot
2282 version information (U_BOOT_VERSION)
2284 - Vendor Parameter Protection:
2286 U-Boot considers the values of the environment
2287 variables "serial#" (Board Serial Number) and
2288 "ethaddr" (Ethernet Address) to be parameters that
2289 are set once by the board vendor / manufacturer, and
2290 protects these variables from casual modification by
2291 the user. Once set, these variables are read-only,
2292 and write or delete attempts are rejected. You can
2293 change this behaviour:
2295 If CONFIG_ENV_OVERWRITE is #defined in your config
2296 file, the write protection for vendor parameters is
2297 completely disabled. Anybody can change or delete
2300 Alternatively, if you #define _both_ CONFIG_ETHADDR
2301 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2302 Ethernet address is installed in the environment,
2303 which can be changed exactly ONCE by the user. [The
2304 serial# is unaffected by this, i. e. it remains
2307 The same can be accomplished in a more flexible way
2308 for any variable by configuring the type of access
2309 to allow for those variables in the ".flags" variable
2310 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2315 Define this variable to enable the reservation of
2316 "protected RAM", i. e. RAM which is not overwritten
2317 by U-Boot. Define CONFIG_PRAM to hold the number of
2318 kB you want to reserve for pRAM. You can overwrite
2319 this default value by defining an environment
2320 variable "pram" to the number of kB you want to
2321 reserve. Note that the board info structure will
2322 still show the full amount of RAM. If pRAM is
2323 reserved, a new environment variable "mem" will
2324 automatically be defined to hold the amount of
2325 remaining RAM in a form that can be passed as boot
2326 argument to Linux, for instance like that:
2328 setenv bootargs ... mem=\${mem}
2331 This way you can tell Linux not to use this memory,
2332 either, which results in a memory region that will
2333 not be affected by reboots.
2335 *WARNING* If your board configuration uses automatic
2336 detection of the RAM size, you must make sure that
2337 this memory test is non-destructive. So far, the
2338 following board configurations are known to be
2341 IVMS8, IVML24, SPD8xx, TQM8xxL,
2342 HERMES, IP860, RPXlite, LWMON,
2345 - Access to physical memory region (> 4GB)
2346 Some basic support is provided for operations on memory not
2347 normally accessible to U-Boot - e.g. some architectures
2348 support access to more than 4GB of memory on 32-bit
2349 machines using physical address extension or similar.
2350 Define CONFIG_PHYSMEM to access this basic support, which
2351 currently only supports clearing the memory.
2356 Define this variable to stop the system in case of a
2357 fatal error, so that you have to reset it manually.
2358 This is probably NOT a good idea for an embedded
2359 system where you want the system to reboot
2360 automatically as fast as possible, but it may be
2361 useful during development since you can try to debug
2362 the conditions that lead to the situation.
2364 CONFIG_NET_RETRY_COUNT
2366 This variable defines the number of retries for
2367 network operations like ARP, RARP, TFTP, or BOOTP
2368 before giving up the operation. If not defined, a
2369 default value of 5 is used.
2373 Timeout waiting for an ARP reply in milliseconds.
2377 Timeout in milliseconds used in NFS protocol.
2378 If you encounter "ERROR: Cannot umount" in nfs command,
2379 try longer timeout such as
2380 #define CONFIG_NFS_TIMEOUT 10000UL
2382 - Command Interpreter:
2383 CONFIG_AUTO_COMPLETE
2385 Enable auto completion of commands using TAB.
2387 Note that this feature has NOT been implemented yet
2388 for the "hush" shell.
2391 CONFIG_SYS_HUSH_PARSER
2393 Define this variable to enable the "hush" shell (from
2394 Busybox) as command line interpreter, thus enabling
2395 powerful command line syntax like
2396 if...then...else...fi conditionals or `&&' and '||'
2397 constructs ("shell scripts").
2399 If undefined, you get the old, much simpler behaviour
2400 with a somewhat smaller memory footprint.
2403 CONFIG_SYS_PROMPT_HUSH_PS2
2405 This defines the secondary prompt string, which is
2406 printed when the command interpreter needs more input
2407 to complete a command. Usually "> ".
2411 In the current implementation, the local variables
2412 space and global environment variables space are
2413 separated. Local variables are those you define by
2414 simply typing `name=value'. To access a local
2415 variable later on, you have write `$name' or
2416 `${name}'; to execute the contents of a variable
2417 directly type `$name' at the command prompt.
2419 Global environment variables are those you use
2420 setenv/printenv to work with. To run a command stored
2421 in such a variable, you need to use the run command,
2422 and you must not use the '$' sign to access them.
2424 To store commands and special characters in a
2425 variable, please use double quotation marks
2426 surrounding the whole text of the variable, instead
2427 of the backslashes before semicolons and special
2430 - Commandline Editing and History:
2431 CONFIG_CMDLINE_EDITING
2433 Enable editing and History functions for interactive
2434 commandline input operations
2436 - Default Environment:
2437 CONFIG_EXTRA_ENV_SETTINGS
2439 Define this to contain any number of null terminated
2440 strings (variable = value pairs) that will be part of
2441 the default environment compiled into the boot image.
2443 For example, place something like this in your
2444 board's config file:
2446 #define CONFIG_EXTRA_ENV_SETTINGS \
2450 Warning: This method is based on knowledge about the
2451 internal format how the environment is stored by the
2452 U-Boot code. This is NOT an official, exported
2453 interface! Although it is unlikely that this format
2454 will change soon, there is no guarantee either.
2455 You better know what you are doing here.
2457 Note: overly (ab)use of the default environment is
2458 discouraged. Make sure to check other ways to preset
2459 the environment like the "source" command or the
2462 CONFIG_ENV_VARS_UBOOT_CONFIG
2464 Define this in order to add variables describing the
2465 U-Boot build configuration to the default environment.
2466 These will be named arch, cpu, board, vendor, and soc.
2468 Enabling this option will cause the following to be defined:
2476 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2478 Define this in order to add variables describing certain
2479 run-time determined information about the hardware to the
2480 environment. These will be named board_name, board_rev.
2482 CONFIG_DELAY_ENVIRONMENT
2484 Normally the environment is loaded when the board is
2485 intialised so that it is available to U-Boot. This inhibits
2486 that so that the environment is not available until
2487 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2488 this is instead controlled by the value of
2489 /config/load-environment.
2491 - DataFlash Support:
2492 CONFIG_HAS_DATAFLASH
2494 Defining this option enables DataFlash features and
2495 allows to read/write in Dataflash via the standard
2498 - Serial Flash support
2501 Defining this option enables SPI flash commands
2502 'sf probe/read/write/erase/update'.
2504 Usage requires an initial 'probe' to define the serial
2505 flash parameters, followed by read/write/erase/update
2508 The following defaults may be provided by the platform
2509 to handle the common case when only a single serial
2510 flash is present on the system.
2512 CONFIG_SF_DEFAULT_BUS Bus identifier
2513 CONFIG_SF_DEFAULT_CS Chip-select
2514 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2515 CONFIG_SF_DEFAULT_SPEED in Hz
2519 Define this option to include a destructive SPI flash
2522 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2524 Define this option to use the Bank addr/Extended addr
2525 support on SPI flashes which has size > 16Mbytes.
2527 - SystemACE Support:
2530 Adding this option adds support for Xilinx SystemACE
2531 chips attached via some sort of local bus. The address
2532 of the chip must also be defined in the
2533 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2535 #define CONFIG_SYSTEMACE
2536 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2538 When SystemACE support is added, the "ace" device type
2539 becomes available to the fat commands, i.e. fatls.
2541 - TFTP Fixed UDP Port:
2544 If this is defined, the environment variable tftpsrcp
2545 is used to supply the TFTP UDP source port value.
2546 If tftpsrcp isn't defined, the normal pseudo-random port
2547 number generator is used.
2549 Also, the environment variable tftpdstp is used to supply
2550 the TFTP UDP destination port value. If tftpdstp isn't
2551 defined, the normal port 69 is used.
2553 The purpose for tftpsrcp is to allow a TFTP server to
2554 blindly start the TFTP transfer using the pre-configured
2555 target IP address and UDP port. This has the effect of
2556 "punching through" the (Windows XP) firewall, allowing
2557 the remainder of the TFTP transfer to proceed normally.
2558 A better solution is to properly configure the firewall,
2559 but sometimes that is not allowed.
2564 This enables a generic 'hash' command which can produce
2565 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2569 Enable the hash verify command (hash -v). This adds to code
2572 CONFIG_SHA1 - support SHA1 hashing
2573 CONFIG_SHA256 - support SHA256 hashing
2575 Note: There is also a sha1sum command, which should perhaps
2576 be deprecated in favour of 'hash sha1'.
2581 This enables the RSA algorithm used for FIT image verification
2582 in U-Boot. See doc/uImage/signature for more information.
2584 The signing part is build into mkimage regardless of this
2588 - Show boot progress:
2589 CONFIG_SHOW_BOOT_PROGRESS
2591 Defining this option allows to add some board-
2592 specific code (calling a user-provided function
2593 "show_boot_progress(int)") that enables you to show
2594 the system's boot progress on some display (for
2595 example, some LED's) on your board. At the moment,
2596 the following checkpoints are implemented:
2598 - Detailed boot stage timing
2600 Define this option to get detailed timing of each stage
2601 of the boot process.
2603 CONFIG_BOOTSTAGE_USER_COUNT
2604 This is the number of available user bootstage records.
2605 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2606 a new ID will be allocated from this stash. If you exceed
2607 the limit, recording will stop.
2609 CONFIG_BOOTSTAGE_REPORT
2610 Define this to print a report before boot, similar to this:
2612 Timer summary in microseconds:
2615 3,575,678 3,575,678 board_init_f start
2616 3,575,695 17 arch_cpu_init A9
2617 3,575,777 82 arch_cpu_init done
2618 3,659,598 83,821 board_init_r start
2619 3,910,375 250,777 main_loop
2620 29,916,167 26,005,792 bootm_start
2621 30,361,327 445,160 start_kernel
2623 CONFIG_CMD_BOOTSTAGE
2624 Add a 'bootstage' command which supports printing a report
2625 and un/stashing of bootstage data.
2627 CONFIG_BOOTSTAGE_FDT
2628 Stash the bootstage information in the FDT. A root 'bootstage'
2629 node is created with each bootstage id as a child. Each child
2630 has a 'name' property and either 'mark' containing the
2631 mark time in microsecond, or 'accum' containing the
2632 accumulated time for that bootstage id in microseconds.
2637 name = "board_init_f";
2646 Code in the Linux kernel can find this in /proc/devicetree.
2648 Legacy uImage format:
2651 1 common/cmd_bootm.c before attempting to boot an image
2652 -1 common/cmd_bootm.c Image header has bad magic number
2653 2 common/cmd_bootm.c Image header has correct magic number
2654 -2 common/cmd_bootm.c Image header has bad checksum
2655 3 common/cmd_bootm.c Image header has correct checksum
2656 -3 common/cmd_bootm.c Image data has bad checksum
2657 4 common/cmd_bootm.c Image data has correct checksum
2658 -4 common/cmd_bootm.c Image is for unsupported architecture
2659 5 common/cmd_bootm.c Architecture check OK
2660 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2661 6 common/cmd_bootm.c Image Type check OK
2662 -6 common/cmd_bootm.c gunzip uncompression error
2663 -7 common/cmd_bootm.c Unimplemented compression type
2664 7 common/cmd_bootm.c Uncompression OK
2665 8 common/cmd_bootm.c No uncompress/copy overwrite error
2666 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2668 9 common/image.c Start initial ramdisk verification
2669 -10 common/image.c Ramdisk header has bad magic number
2670 -11 common/image.c Ramdisk header has bad checksum
2671 10 common/image.c Ramdisk header is OK
2672 -12 common/image.c Ramdisk data has bad checksum
2673 11 common/image.c Ramdisk data has correct checksum
2674 12 common/image.c Ramdisk verification complete, start loading
2675 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2676 13 common/image.c Start multifile image verification
2677 14 common/image.c No initial ramdisk, no multifile, continue.
2679 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2681 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2682 -31 post/post.c POST test failed, detected by post_output_backlog()
2683 -32 post/post.c POST test failed, detected by post_run_single()
2685 34 common/cmd_doc.c before loading a Image from a DOC device
2686 -35 common/cmd_doc.c Bad usage of "doc" command
2687 35 common/cmd_doc.c correct usage of "doc" command
2688 -36 common/cmd_doc.c No boot device
2689 36 common/cmd_doc.c correct boot device
2690 -37 common/cmd_doc.c Unknown Chip ID on boot device
2691 37 common/cmd_doc.c correct chip ID found, device available
2692 -38 common/cmd_doc.c Read Error on boot device
2693 38 common/cmd_doc.c reading Image header from DOC device OK
2694 -39 common/cmd_doc.c Image header has bad magic number
2695 39 common/cmd_doc.c Image header has correct magic number
2696 -40 common/cmd_doc.c Error reading Image from DOC device
2697 40 common/cmd_doc.c Image header has correct magic number
2698 41 common/cmd_ide.c before loading a Image from a IDE device
2699 -42 common/cmd_ide.c Bad usage of "ide" command
2700 42 common/cmd_ide.c correct usage of "ide" command
2701 -43 common/cmd_ide.c No boot device
2702 43 common/cmd_ide.c boot device found
2703 -44 common/cmd_ide.c Device not available
2704 44 common/cmd_ide.c Device available
2705 -45 common/cmd_ide.c wrong partition selected
2706 45 common/cmd_ide.c partition selected
2707 -46 common/cmd_ide.c Unknown partition table
2708 46 common/cmd_ide.c valid partition table found
2709 -47 common/cmd_ide.c Invalid partition type
2710 47 common/cmd_ide.c correct partition type
2711 -48 common/cmd_ide.c Error reading Image Header on boot device
2712 48 common/cmd_ide.c reading Image Header from IDE device OK
2713 -49 common/cmd_ide.c Image header has bad magic number
2714 49 common/cmd_ide.c Image header has correct magic number
2715 -50 common/cmd_ide.c Image header has bad checksum
2716 50 common/cmd_ide.c Image header has correct checksum
2717 -51 common/cmd_ide.c Error reading Image from IDE device
2718 51 common/cmd_ide.c reading Image from IDE device OK
2719 52 common/cmd_nand.c before loading a Image from a NAND device
2720 -53 common/cmd_nand.c Bad usage of "nand" command
2721 53 common/cmd_nand.c correct usage of "nand" command
2722 -54 common/cmd_nand.c No boot device
2723 54 common/cmd_nand.c boot device found
2724 -55 common/cmd_nand.c Unknown Chip ID on boot device
2725 55 common/cmd_nand.c correct chip ID found, device available
2726 -56 common/cmd_nand.c Error reading Image Header on boot device
2727 56 common/cmd_nand.c reading Image Header from NAND device OK
2728 -57 common/cmd_nand.c Image header has bad magic number
2729 57 common/cmd_nand.c Image header has correct magic number
2730 -58 common/cmd_nand.c Error reading Image from NAND device
2731 58 common/cmd_nand.c reading Image from NAND device OK
2733 -60 common/env_common.c Environment has a bad CRC, using default
2735 64 net/eth.c starting with Ethernet configuration.
2736 -64 net/eth.c no Ethernet found.
2737 65 net/eth.c Ethernet found.
2739 -80 common/cmd_net.c usage wrong
2740 80 common/cmd_net.c before calling NetLoop()
2741 -81 common/cmd_net.c some error in NetLoop() occurred
2742 81 common/cmd_net.c NetLoop() back without error
2743 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2744 82 common/cmd_net.c trying automatic boot
2745 83 common/cmd_net.c running "source" command
2746 -83 common/cmd_net.c some error in automatic boot or "source" command
2747 84 common/cmd_net.c end without errors
2752 100 common/cmd_bootm.c Kernel FIT Image has correct format
2753 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2754 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2755 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2756 102 common/cmd_bootm.c Kernel unit name specified
2757 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2758 103 common/cmd_bootm.c Found configuration node
2759 104 common/cmd_bootm.c Got kernel subimage node offset
2760 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2761 105 common/cmd_bootm.c Kernel subimage hash verification OK
2762 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2763 106 common/cmd_bootm.c Architecture check OK
2764 -106 common/cmd_bootm.c Kernel subimage has wrong type
2765 107 common/cmd_bootm.c Kernel subimage type OK
2766 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2767 108 common/cmd_bootm.c Got kernel subimage data/size
2768 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2769 -109 common/cmd_bootm.c Can't get kernel subimage type
2770 -110 common/cmd_bootm.c Can't get kernel subimage comp
2771 -111 common/cmd_bootm.c Can't get kernel subimage os
2772 -112 common/cmd_bootm.c Can't get kernel subimage load address
2773 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2775 120 common/image.c Start initial ramdisk verification
2776 -120 common/image.c Ramdisk FIT image has incorrect format
2777 121 common/image.c Ramdisk FIT image has correct format
2778 122 common/image.c No ramdisk subimage unit name, using configuration
2779 -122 common/image.c Can't get configuration for ramdisk subimage
2780 123 common/image.c Ramdisk unit name specified
2781 -124 common/image.c Can't get ramdisk subimage node offset
2782 125 common/image.c Got ramdisk subimage node offset
2783 -125 common/image.c Ramdisk subimage hash verification failed
2784 126 common/image.c Ramdisk subimage hash verification OK
2785 -126 common/image.c Ramdisk subimage for unsupported architecture
2786 127 common/image.c Architecture check OK
2787 -127 common/image.c Can't get ramdisk subimage data/size
2788 128 common/image.c Got ramdisk subimage data/size
2789 129 common/image.c Can't get ramdisk load address
2790 -129 common/image.c Got ramdisk load address
2792 -130 common/cmd_doc.c Incorrect FIT image format
2793 131 common/cmd_doc.c FIT image format OK
2795 -140 common/cmd_ide.c Incorrect FIT image format
2796 141 common/cmd_ide.c FIT image format OK
2798 -150 common/cmd_nand.c Incorrect FIT image format
2799 151 common/cmd_nand.c FIT image format OK
2801 - FIT image support:
2803 Enable support for the FIT uImage format.
2805 CONFIG_FIT_BEST_MATCH
2806 When no configuration is explicitly selected, default to the
2807 one whose fdt's compatibility field best matches that of
2808 U-Boot itself. A match is considered "best" if it matches the
2809 most specific compatibility entry of U-Boot's fdt's root node.
2810 The order of entries in the configuration's fdt is ignored.
2812 CONFIG_FIT_SIGNATURE
2813 This option enables signature verification of FIT uImages,
2814 using a hash signed and verified using RSA. See
2815 doc/uImage.FIT/signature.txt for more details.
2817 - Standalone program support:
2818 CONFIG_STANDALONE_LOAD_ADDR
2820 This option defines a board specific value for the
2821 address where standalone program gets loaded, thus
2822 overwriting the architecture dependent default
2825 - Frame Buffer Address:
2828 Define CONFIG_FB_ADDR if you want to use specific
2829 address for frame buffer. This is typically the case
2830 when using a graphics controller has separate video
2831 memory. U-Boot will then place the frame buffer at
2832 the given address instead of dynamically reserving it
2833 in system RAM by calling lcd_setmem(), which grabs
2834 the memory for the frame buffer depending on the
2835 configured panel size.
2837 Please see board_init_f function.
2839 - Automatic software updates via TFTP server
2841 CONFIG_UPDATE_TFTP_CNT_MAX
2842 CONFIG_UPDATE_TFTP_MSEC_MAX
2844 These options enable and control the auto-update feature;
2845 for a more detailed description refer to doc/README.update.
2847 - MTD Support (mtdparts command, UBI support)
2850 Adds the MTD device infrastructure from the Linux kernel.
2851 Needed for mtdparts command support.
2853 CONFIG_MTD_PARTITIONS
2855 Adds the MTD partitioning infrastructure from the Linux
2856 kernel. Needed for UBI support.
2861 Adds commands for interacting with MTD partitions formatted
2862 with the UBI flash translation layer
2864 Requires also defining CONFIG_RBTREE
2866 CONFIG_UBI_SILENCE_MSG
2868 Make the verbose messages from UBI stop printing. This leaves
2869 warnings and errors enabled.
2874 Adds commands for interacting with UBI volumes formatted as
2875 UBIFS. UBIFS is read-only in u-boot.
2877 Requires UBI support as well as CONFIG_LZO
2879 CONFIG_UBIFS_SILENCE_MSG
2881 Make the verbose messages from UBIFS stop printing. This leaves
2882 warnings and errors enabled.
2886 Enable building of SPL globally.
2889 LDSCRIPT for linking the SPL binary.
2891 CONFIG_SPL_MAX_FOOTPRINT
2892 Maximum size in memory allocated to the SPL, BSS included.
2893 When defined, the linker checks that the actual memory
2894 used by SPL from _start to __bss_end does not exceed it.
2895 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2896 must not be both defined at the same time.
2899 Maximum size of the SPL image (text, data, rodata, and
2900 linker lists sections), BSS excluded.
2901 When defined, the linker checks that the actual size does
2904 CONFIG_SPL_TEXT_BASE
2905 TEXT_BASE for linking the SPL binary.
2907 CONFIG_SPL_RELOC_TEXT_BASE
2908 Address to relocate to. If unspecified, this is equal to
2909 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2911 CONFIG_SPL_BSS_START_ADDR
2912 Link address for the BSS within the SPL binary.
2914 CONFIG_SPL_BSS_MAX_SIZE
2915 Maximum size in memory allocated to the SPL BSS.
2916 When defined, the linker checks that the actual memory used
2917 by SPL from __bss_start to __bss_end does not exceed it.
2918 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2919 must not be both defined at the same time.
2922 Adress of the start of the stack SPL will use
2924 CONFIG_SPL_RELOC_STACK
2925 Adress of the start of the stack SPL will use after
2926 relocation. If unspecified, this is equal to
2929 CONFIG_SYS_SPL_MALLOC_START
2930 Starting address of the malloc pool used in SPL.
2932 CONFIG_SYS_SPL_MALLOC_SIZE
2933 The size of the malloc pool used in SPL.
2935 CONFIG_SPL_FRAMEWORK
2936 Enable the SPL framework under common/. This framework
2937 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2938 NAND loading of the Linux Kernel.
2940 CONFIG_SPL_DISPLAY_PRINT
2941 For ARM, enable an optional function to print more information
2942 about the running system.
2944 CONFIG_SPL_INIT_MINIMAL
2945 Arch init code should be built for a very small image
2947 CONFIG_SPL_LIBCOMMON_SUPPORT
2948 Support for common/libcommon.o in SPL binary
2950 CONFIG_SPL_LIBDISK_SUPPORT
2951 Support for disk/libdisk.o in SPL binary
2953 CONFIG_SPL_I2C_SUPPORT
2954 Support for drivers/i2c/libi2c.o in SPL binary
2956 CONFIG_SPL_GPIO_SUPPORT
2957 Support for drivers/gpio/libgpio.o in SPL binary
2959 CONFIG_SPL_MMC_SUPPORT
2960 Support for drivers/mmc/libmmc.o in SPL binary
2962 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2963 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2964 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2965 Address, size and partition on the MMC to load U-Boot from
2966 when the MMC is being used in raw mode.
2968 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2969 Sector to load kernel uImage from when MMC is being
2970 used in raw mode (for Falcon mode)
2972 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2973 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2974 Sector and number of sectors to load kernel argument
2975 parameters from when MMC is being used in raw mode
2978 CONFIG_SPL_FAT_SUPPORT
2979 Support for fs/fat/libfat.o in SPL binary
2981 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2982 Filename to read to load U-Boot when reading from FAT
2984 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
2985 Filename to read to load kernel uImage when reading
2986 from FAT (for Falcon mode)
2988 CONFIG_SPL_FAT_LOAD_ARGS_NAME
2989 Filename to read to load kernel argument parameters
2990 when reading from FAT (for Falcon mode)
2992 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2993 Set this for NAND SPL on PPC mpc83xx targets, so that
2994 start.S waits for the rest of the SPL to load before
2995 continuing (the hardware starts execution after just
2996 loading the first page rather than the full 4K).
2998 CONFIG_SPL_NAND_BASE
2999 Include nand_base.c in the SPL. Requires
3000 CONFIG_SPL_NAND_DRIVERS.
3002 CONFIG_SPL_NAND_DRIVERS
3003 SPL uses normal NAND drivers, not minimal drivers.
3006 Include standard software ECC in the SPL
3008 CONFIG_SPL_NAND_SIMPLE
3009 Support for NAND boot using simple NAND drivers that
3010 expose the cmd_ctrl() interface.
3012 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3013 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3014 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3015 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3016 CONFIG_SYS_NAND_ECCBYTES
3017 Defines the size and behavior of the NAND that SPL uses
3020 CONFIG_SYS_NAND_U_BOOT_OFFS
3021 Location in NAND to read U-Boot from
3023 CONFIG_SYS_NAND_U_BOOT_DST
3024 Location in memory to load U-Boot to
3026 CONFIG_SYS_NAND_U_BOOT_SIZE
3027 Size of image to load
3029 CONFIG_SYS_NAND_U_BOOT_START
3030 Entry point in loaded image to jump to
3032 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3033 Define this if you need to first read the OOB and then the
3034 data. This is used for example on davinci plattforms.
3036 CONFIG_SPL_OMAP3_ID_NAND
3037 Support for an OMAP3-specific set of functions to return the
3038 ID and MFR of the first attached NAND chip, if present.
3040 CONFIG_SPL_SERIAL_SUPPORT
3041 Support for drivers/serial/libserial.o in SPL binary
3043 CONFIG_SPL_SPI_FLASH_SUPPORT
3044 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3046 CONFIG_SPL_SPI_SUPPORT
3047 Support for drivers/spi/libspi.o in SPL binary
3049 CONFIG_SPL_RAM_DEVICE
3050 Support for running image already present in ram, in SPL binary
3052 CONFIG_SPL_LIBGENERIC_SUPPORT
3053 Support for lib/libgeneric.o in SPL binary
3055 CONFIG_SPL_ENV_SUPPORT
3056 Support for the environment operating in SPL binary
3058 CONFIG_SPL_NET_SUPPORT
3059 Support for the net/libnet.o in SPL binary.
3060 It conflicts with SPL env from storage medium specified by
3061 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3064 Image offset to which the SPL should be padded before appending
3065 the SPL payload. By default, this is defined as
3066 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3067 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3068 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3071 Final target image containing SPL and payload. Some SPLs
3072 use an arch-specific makefile fragment instead, for
3073 example if more than one image needs to be produced.
3075 CONFIG_FIT_SPL_PRINT
3076 Printing information about a FIT image adds quite a bit of
3077 code to SPL. So this is normally disabled in SPL. Use this
3078 option to re-enable it. This will affect the output of the
3079 bootm command when booting a FIT image.
3084 [so far only for SMDK2400 boards]
3086 - Modem support enable:
3087 CONFIG_MODEM_SUPPORT
3089 - RTS/CTS Flow control enable:
3092 - Modem debug support:
3093 CONFIG_MODEM_SUPPORT_DEBUG
3095 Enables debugging stuff (char screen[1024], dbg())
3096 for modem support. Useful only with BDI2000.
3098 - Interrupt support (PPC):
3100 There are common interrupt_init() and timer_interrupt()
3101 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3102 for CPU specific initialization. interrupt_init_cpu()
3103 should set decrementer_count to appropriate value. If
3104 CPU resets decrementer automatically after interrupt
3105 (ppc4xx) it should set decrementer_count to zero.
3106 timer_interrupt() calls timer_interrupt_cpu() for CPU
3107 specific handling. If board has watchdog / status_led
3108 / other_activity_monitor it works automatically from
3109 general timer_interrupt().
3113 In the target system modem support is enabled when a
3114 specific key (key combination) is pressed during
3115 power-on. Otherwise U-Boot will boot normally
3116 (autoboot). The key_pressed() function is called from
3117 board_init(). Currently key_pressed() is a dummy
3118 function, returning 1 and thus enabling modem
3121 If there are no modem init strings in the
3122 environment, U-Boot proceed to autoboot; the
3123 previous output (banner, info printfs) will be
3126 See also: doc/README.Modem
3128 Board initialization settings:
3129 ------------------------------
3131 During Initialization u-boot calls a number of board specific functions
3132 to allow the preparation of board specific prerequisites, e.g. pin setup
3133 before drivers are initialized. To enable these callbacks the
3134 following configuration macros have to be defined. Currently this is
3135 architecture specific, so please check arch/your_architecture/lib/board.c
3136 typically in board_init_f() and board_init_r().
3138 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3139 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3140 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3141 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3143 Configuration Settings:
3144 -----------------------
3146 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3147 undefine this when you're short of memory.
3149 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3150 width of the commands listed in the 'help' command output.
3152 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3153 prompt for user input.
3155 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3157 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3159 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3161 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3162 the application (usually a Linux kernel) when it is
3165 - CONFIG_SYS_BAUDRATE_TABLE:
3166 List of legal baudrate settings for this board.
3168 - CONFIG_SYS_CONSOLE_INFO_QUIET
3169 Suppress display of console information at boot.
3171 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3172 If the board specific function
3173 extern int overwrite_console (void);
3174 returns 1, the stdin, stderr and stdout are switched to the
3175 serial port, else the settings in the environment are used.
3177 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3178 Enable the call to overwrite_console().
3180 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3181 Enable overwrite of previous console environment settings.
3183 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3184 Begin and End addresses of the area used by the
3187 - CONFIG_SYS_ALT_MEMTEST:
3188 Enable an alternate, more extensive memory test.
3190 - CONFIG_SYS_MEMTEST_SCRATCH:
3191 Scratch address used by the alternate memory test
3192 You only need to set this if address zero isn't writeable
3194 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3195 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3196 this specified memory area will get subtracted from the top
3197 (end) of RAM and won't get "touched" at all by U-Boot. By
3198 fixing up gd->ram_size the Linux kernel should gets passed
3199 the now "corrected" memory size and won't touch it either.
3200 This should work for arch/ppc and arch/powerpc. Only Linux
3201 board ports in arch/powerpc with bootwrapper support that
3202 recalculate the memory size from the SDRAM controller setup
3203 will have to get fixed in Linux additionally.
3205 This option can be used as a workaround for the 440EPx/GRx
3206 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3209 WARNING: Please make sure that this value is a multiple of
3210 the Linux page size (normally 4k). If this is not the case,
3211 then the end address of the Linux memory will be located at a
3212 non page size aligned address and this could cause major
3215 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3216 Enable temporary baudrate change while serial download
3218 - CONFIG_SYS_SDRAM_BASE:
3219 Physical start address of SDRAM. _Must_ be 0 here.
3221 - CONFIG_SYS_MBIO_BASE:
3222 Physical start address of Motherboard I/O (if using a
3225 - CONFIG_SYS_FLASH_BASE:
3226 Physical start address of Flash memory.
3228 - CONFIG_SYS_MONITOR_BASE:
3229 Physical start address of boot monitor code (set by
3230 make config files to be same as the text base address
3231 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3232 CONFIG_SYS_FLASH_BASE when booting from flash.
3234 - CONFIG_SYS_MONITOR_LEN:
3235 Size of memory reserved for monitor code, used to
3236 determine _at_compile_time_ (!) if the environment is
3237 embedded within the U-Boot image, or in a separate
3240 - CONFIG_SYS_MALLOC_LEN:
3241 Size of DRAM reserved for malloc() use.
3243 - CONFIG_SYS_BOOTM_LEN:
3244 Normally compressed uImages are limited to an
3245 uncompressed size of 8 MBytes. If this is not enough,
3246 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3247 to adjust this setting to your needs.
3249 - CONFIG_SYS_BOOTMAPSZ:
3250 Maximum size of memory mapped by the startup code of
3251 the Linux kernel; all data that must be processed by
3252 the Linux kernel (bd_info, boot arguments, FDT blob if
3253 used) must be put below this limit, unless "bootm_low"
3254 enviroment variable is defined and non-zero. In such case
3255 all data for the Linux kernel must be between "bootm_low"
3256 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3257 variable "bootm_mapsize" will override the value of
3258 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3259 then the value in "bootm_size" will be used instead.
3261 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3262 Enable initrd_high functionality. If defined then the
3263 initrd_high feature is enabled and the bootm ramdisk subcommand
3266 - CONFIG_SYS_BOOT_GET_CMDLINE:
3267 Enables allocating and saving kernel cmdline in space between
3268 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3270 - CONFIG_SYS_BOOT_GET_KBD:
3271 Enables allocating and saving a kernel copy of the bd_info in
3272 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3274 - CONFIG_SYS_MAX_FLASH_BANKS:
3275 Max number of Flash memory banks
3277 - CONFIG_SYS_MAX_FLASH_SECT:
3278 Max number of sectors on a Flash chip
3280 - CONFIG_SYS_FLASH_ERASE_TOUT:
3281 Timeout for Flash erase operations (in ms)
3283 - CONFIG_SYS_FLASH_WRITE_TOUT:
3284 Timeout for Flash write operations (in ms)
3286 - CONFIG_SYS_FLASH_LOCK_TOUT
3287 Timeout for Flash set sector lock bit operation (in ms)
3289 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3290 Timeout for Flash clear lock bits operation (in ms)
3292 - CONFIG_SYS_FLASH_PROTECTION
3293 If defined, hardware flash sectors protection is used
3294 instead of U-Boot software protection.
3296 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3298 Enable TFTP transfers directly to flash memory;
3299 without this option such a download has to be
3300 performed in two steps: (1) download to RAM, and (2)
3301 copy from RAM to flash.
3303 The two-step approach is usually more reliable, since
3304 you can check if the download worked before you erase
3305 the flash, but in some situations (when system RAM is
3306 too limited to allow for a temporary copy of the
3307 downloaded image) this option may be very useful.
3309 - CONFIG_SYS_FLASH_CFI:
3310 Define if the flash driver uses extra elements in the
3311 common flash structure for storing flash geometry.
3313 - CONFIG_FLASH_CFI_DRIVER
3314 This option also enables the building of the cfi_flash driver
3315 in the drivers directory
3317 - CONFIG_FLASH_CFI_MTD
3318 This option enables the building of the cfi_mtd driver
3319 in the drivers directory. The driver exports CFI flash
3322 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3323 Use buffered writes to flash.
3325 - CONFIG_FLASH_SPANSION_S29WS_N
3326 s29ws-n MirrorBit flash has non-standard addresses for buffered
3329 - CONFIG_SYS_FLASH_QUIET_TEST
3330 If this option is defined, the common CFI flash doesn't
3331 print it's warning upon not recognized FLASH banks. This
3332 is useful, if some of the configured banks are only
3333 optionally available.
3335 - CONFIG_FLASH_SHOW_PROGRESS
3336 If defined (must be an integer), print out countdown
3337 digits and dots. Recommended value: 45 (9..1) for 80
3338 column displays, 15 (3..1) for 40 column displays.
3340 - CONFIG_FLASH_VERIFY
3341 If defined, the content of the flash (destination) is compared
3342 against the source after the write operation. An error message
3343 will be printed when the contents are not identical.
3344 Please note that this option is useless in nearly all cases,
3345 since such flash programming errors usually are detected earlier
3346 while unprotecting/erasing/programming. Please only enable
3347 this option if you really know what you are doing.
3349 - CONFIG_SYS_RX_ETH_BUFFER:
3350 Defines the number of Ethernet receive buffers. On some
3351 Ethernet controllers it is recommended to set this value
3352 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3353 buffers can be full shortly after enabling the interface
3354 on high Ethernet traffic.
3355 Defaults to 4 if not defined.
3357 - CONFIG_ENV_MAX_ENTRIES
3359 Maximum number of entries in the hash table that is used
3360 internally to store the environment settings. The default
3361 setting is supposed to be generous and should work in most
3362 cases. This setting can be used to tune behaviour; see
3363 lib/hashtable.c for details.
3365 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3366 - CONFIG_ENV_FLAGS_LIST_STATIC
3367 Enable validation of the values given to enviroment variables when
3368 calling env set. Variables can be restricted to only decimal,
3369 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3370 the variables can also be restricted to IP address or MAC address.
3372 The format of the list is:
3373 type_attribute = [s|d|x|b|i|m]
3374 access_atribute = [a|r|o|c]
3375 attributes = type_attribute[access_atribute]
3376 entry = variable_name[:attributes]
3379 The type attributes are:
3380 s - String (default)
3383 b - Boolean ([1yYtT|0nNfF])
3387 The access attributes are:
3393 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3394 Define this to a list (string) to define the ".flags"
3395 envirnoment variable in the default or embedded environment.
3397 - CONFIG_ENV_FLAGS_LIST_STATIC
3398 Define this to a list (string) to define validation that
3399 should be done if an entry is not found in the ".flags"
3400 environment variable. To override a setting in the static
3401 list, simply add an entry for the same variable name to the
3404 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3405 If defined, don't allow the -f switch to env set override variable
3408 - CONFIG_SYS_GENERIC_BOARD
3409 This selects the architecture-generic board system instead of the
3410 architecture-specific board files. It is intended to move boards
3411 to this new framework over time. Defining this will disable the
3412 arch/foo/lib/board.c file and use common/board_f.c and
3413 common/board_r.c instead. To use this option your architecture
3414 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3415 its config.mk file). If you find problems enabling this option on
3416 your board please report the problem and send patches!
3418 - CONFIG_SYS_SYM_OFFSETS
3419 This is set by architectures that use offsets for link symbols
3420 instead of absolute values. So bss_start is obtained using an
3421 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3422 directly. You should not need to touch this setting.
3424 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3425 This is set by OMAP boards for the max time that reset should
3426 be asserted. See doc/README.omap-reset-time for details on how
3427 the value can be calulated on a given board.
3429 The following definitions that deal with the placement and management
3430 of environment data (variable area); in general, we support the
3431 following configurations:
3433 - CONFIG_BUILD_ENVCRC:
3435 Builds up envcrc with the target environment so that external utils
3436 may easily extract it and embed it in final U-Boot images.
3438 - CONFIG_ENV_IS_IN_FLASH:
3440 Define this if the environment is in flash memory.
3442 a) The environment occupies one whole flash sector, which is
3443 "embedded" in the text segment with the U-Boot code. This
3444 happens usually with "bottom boot sector" or "top boot
3445 sector" type flash chips, which have several smaller
3446 sectors at the start or the end. For instance, such a
3447 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3448 such a case you would place the environment in one of the
3449 4 kB sectors - with U-Boot code before and after it. With
3450 "top boot sector" type flash chips, you would put the
3451 environment in one of the last sectors, leaving a gap
3452 between U-Boot and the environment.
3454 - CONFIG_ENV_OFFSET:
3456 Offset of environment data (variable area) to the
3457 beginning of flash memory; for instance, with bottom boot
3458 type flash chips the second sector can be used: the offset
3459 for this sector is given here.
3461 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3465 This is just another way to specify the start address of
3466 the flash sector containing the environment (instead of
3469 - CONFIG_ENV_SECT_SIZE:
3471 Size of the sector containing the environment.
3474 b) Sometimes flash chips have few, equal sized, BIG sectors.
3475 In such a case you don't want to spend a whole sector for
3480 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3481 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3482 of this flash sector for the environment. This saves
3483 memory for the RAM copy of the environment.
3485 It may also save flash memory if you decide to use this
3486 when your environment is "embedded" within U-Boot code,
3487 since then the remainder of the flash sector could be used
3488 for U-Boot code. It should be pointed out that this is
3489 STRONGLY DISCOURAGED from a robustness point of view:
3490 updating the environment in flash makes it always
3491 necessary to erase the WHOLE sector. If something goes
3492 wrong before the contents has been restored from a copy in
3493 RAM, your target system will be dead.
3495 - CONFIG_ENV_ADDR_REDUND
3496 CONFIG_ENV_SIZE_REDUND
3498 These settings describe a second storage area used to hold
3499 a redundant copy of the environment data, so that there is
3500 a valid backup copy in case there is a power failure during
3501 a "saveenv" operation.
3503 BE CAREFUL! Any changes to the flash layout, and some changes to the
3504 source code will make it necessary to adapt <board>/u-boot.lds*
3508 - CONFIG_ENV_IS_IN_NVRAM:
3510 Define this if you have some non-volatile memory device
3511 (NVRAM, battery buffered SRAM) which you want to use for the
3517 These two #defines are used to determine the memory area you
3518 want to use for environment. It is assumed that this memory
3519 can just be read and written to, without any special
3522 BE CAREFUL! The first access to the environment happens quite early
3523 in U-Boot initalization (when we try to get the setting of for the
3524 console baudrate). You *MUST* have mapped your NVRAM area then, or
3527 Please note that even with NVRAM we still use a copy of the
3528 environment in RAM: we could work on NVRAM directly, but we want to
3529 keep settings there always unmodified except somebody uses "saveenv"
3530 to save the current settings.
3533 - CONFIG_ENV_IS_IN_EEPROM:
3535 Use this if you have an EEPROM or similar serial access
3536 device and a driver for it.
3538 - CONFIG_ENV_OFFSET:
3541 These two #defines specify the offset and size of the
3542 environment area within the total memory of your EEPROM.
3544 - CONFIG_SYS_I2C_EEPROM_ADDR:
3545 If defined, specified the chip address of the EEPROM device.
3546 The default address is zero.
3548 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3549 If defined, the number of bits used to address bytes in a
3550 single page in the EEPROM device. A 64 byte page, for example
3551 would require six bits.
3553 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3554 If defined, the number of milliseconds to delay between
3555 page writes. The default is zero milliseconds.
3557 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3558 The length in bytes of the EEPROM memory array address. Note
3559 that this is NOT the chip address length!
3561 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3562 EEPROM chips that implement "address overflow" are ones
3563 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3564 address and the extra bits end up in the "chip address" bit
3565 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3568 Note that we consider the length of the address field to
3569 still be one byte because the extra address bits are hidden
3570 in the chip address.
3572 - CONFIG_SYS_EEPROM_SIZE:
3573 The size in bytes of the EEPROM device.
3575 - CONFIG_ENV_EEPROM_IS_ON_I2C
3576 define this, if you have I2C and SPI activated, and your
3577 EEPROM, which holds the environment, is on the I2C bus.
3579 - CONFIG_I2C_ENV_EEPROM_BUS
3580 if you have an Environment on an EEPROM reached over
3581 I2C muxes, you can define here, how to reach this
3582 EEPROM. For example:
3584 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3586 EEPROM which holds the environment, is reached over
3587 a pca9547 i2c mux with address 0x70, channel 3.
3589 - CONFIG_ENV_IS_IN_DATAFLASH:
3591 Define this if you have a DataFlash memory device which you
3592 want to use for the environment.
3594 - CONFIG_ENV_OFFSET:
3598 These three #defines specify the offset and size of the
3599 environment area within the total memory of your DataFlash placed
3600 at the specified address.
3602 - CONFIG_ENV_IS_IN_REMOTE:
3604 Define this if you have a remote memory space which you
3605 want to use for the local device's environment.
3610 These two #defines specify the address and size of the
3611 environment area within the remote memory space. The
3612 local device can get the environment from remote memory
3613 space by SRIO or PCIE links.
3615 BE CAREFUL! For some special cases, the local device can not use
3616 "saveenv" command. For example, the local device will get the
3617 environment stored in a remote NOR flash by SRIO or PCIE link,
3618 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3620 - CONFIG_ENV_IS_IN_NAND:
3622 Define this if you have a NAND device which you want to use
3623 for the environment.
3625 - CONFIG_ENV_OFFSET:
3628 These two #defines specify the offset and size of the environment
3629 area within the first NAND device. CONFIG_ENV_OFFSET must be
3630 aligned to an erase block boundary.
3632 - CONFIG_ENV_OFFSET_REDUND (optional):
3634 This setting describes a second storage area of CONFIG_ENV_SIZE
3635 size used to hold a redundant copy of the environment data, so
3636 that there is a valid backup copy in case there is a power failure
3637 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3638 aligned to an erase block boundary.
3640 - CONFIG_ENV_RANGE (optional):
3642 Specifies the length of the region in which the environment
3643 can be written. This should be a multiple of the NAND device's
3644 block size. Specifying a range with more erase blocks than
3645 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3646 the range to be avoided.
3648 - CONFIG_ENV_OFFSET_OOB (optional):
3650 Enables support for dynamically retrieving the offset of the
3651 environment from block zero's out-of-band data. The
3652 "nand env.oob" command can be used to record this offset.
3653 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3654 using CONFIG_ENV_OFFSET_OOB.
3656 - CONFIG_NAND_ENV_DST
3658 Defines address in RAM to which the nand_spl code should copy the
3659 environment. If redundant environment is used, it will be copied to
3660 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3662 - CONFIG_ENV_IS_IN_UBI:
3664 Define this if you have an UBI volume that you want to use for the
3665 environment. This has the benefit of wear-leveling the environment
3666 accesses, which is important on NAND.
3668 - CONFIG_ENV_UBI_PART:
3670 Define this to a string that is the mtd partition containing the UBI.
3672 - CONFIG_ENV_UBI_VOLUME:
3674 Define this to the name of the volume that you want to store the
3677 - CONFIG_ENV_UBI_VOLUME_REDUND:
3679 Define this to the name of another volume to store a second copy of
3680 the environment in. This will enable redundant environments in UBI.
3681 It is assumed that both volumes are in the same MTD partition.
3683 - CONFIG_UBI_SILENCE_MSG
3684 - CONFIG_UBIFS_SILENCE_MSG
3686 You will probably want to define these to avoid a really noisy system
3687 when storing the env in UBI.
3689 - CONFIG_ENV_IS_IN_MMC:
3691 Define this if you have an MMC device which you want to use for the
3694 - CONFIG_SYS_MMC_ENV_DEV:
3696 Specifies which MMC device the environment is stored in.
3698 - CONFIG_SYS_MMC_ENV_PART (optional):
3700 Specifies which MMC partition the environment is stored in. If not
3701 set, defaults to partition 0, the user area. Common values might be
3702 1 (first MMC boot partition), 2 (second MMC boot partition).
3704 - CONFIG_ENV_OFFSET:
3707 These two #defines specify the offset and size of the environment
3708 area within the specified MMC device.
3710 If offset is positive (the usual case), it is treated as relative to
3711 the start of the MMC partition. If offset is negative, it is treated
3712 as relative to the end of the MMC partition. This can be useful if
3713 your board may be fitted with different MMC devices, which have
3714 different sizes for the MMC partitions, and you always want the
3715 environment placed at the very end of the partition, to leave the
3716 maximum possible space before it, to store other data.
3718 These two values are in units of bytes, but must be aligned to an
3719 MMC sector boundary.
3721 - CONFIG_ENV_OFFSET_REDUND (optional):
3723 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3724 hold a redundant copy of the environment data. This provides a
3725 valid backup copy in case the other copy is corrupted, e.g. due
3726 to a power failure during a "saveenv" operation.
3728 This value may also be positive or negative; this is handled in the
3729 same way as CONFIG_ENV_OFFSET.
3731 This value is also in units of bytes, but must also be aligned to
3732 an MMC sector boundary.
3734 - CONFIG_ENV_SIZE_REDUND (optional):
3736 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3737 set. If this value is set, it must be set to the same value as
3740 - CONFIG_SYS_SPI_INIT_OFFSET
3742 Defines offset to the initial SPI buffer area in DPRAM. The
3743 area is used at an early stage (ROM part) if the environment
3744 is configured to reside in the SPI EEPROM: We need a 520 byte
3745 scratch DPRAM area. It is used between the two initialization
3746 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3747 to be a good choice since it makes it far enough from the
3748 start of the data area as well as from the stack pointer.
3750 Please note that the environment is read-only until the monitor
3751 has been relocated to RAM and a RAM copy of the environment has been
3752 created; also, when using EEPROM you will have to use getenv_f()
3753 until then to read environment variables.
3755 The environment is protected by a CRC32 checksum. Before the monitor
3756 is relocated into RAM, as a result of a bad CRC you will be working
3757 with the compiled-in default environment - *silently*!!! [This is
3758 necessary, because the first environment variable we need is the
3759 "baudrate" setting for the console - if we have a bad CRC, we don't
3760 have any device yet where we could complain.]
3762 Note: once the monitor has been relocated, then it will complain if
3763 the default environment is used; a new CRC is computed as soon as you
3764 use the "saveenv" command to store a valid environment.
3766 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3767 Echo the inverted Ethernet link state to the fault LED.
3769 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3770 also needs to be defined.
3772 - CONFIG_SYS_FAULT_MII_ADDR:
3773 MII address of the PHY to check for the Ethernet link state.
3775 - CONFIG_NS16550_MIN_FUNCTIONS:
3776 Define this if you desire to only have use of the NS16550_init
3777 and NS16550_putc functions for the serial driver located at
3778 drivers/serial/ns16550.c. This option is useful for saving
3779 space for already greatly restricted images, including but not
3780 limited to NAND_SPL configurations.
3782 - CONFIG_DISPLAY_BOARDINFO
3783 Display information about the board that U-Boot is running on
3784 when U-Boot starts up. The board function checkboard() is called
3787 - CONFIG_DISPLAY_BOARDINFO_LATE
3788 Similar to the previous option, but display this information
3789 later, once stdio is running and output goes to the LCD, if
3792 Low Level (hardware related) configuration options:
3793 ---------------------------------------------------
3795 - CONFIG_SYS_CACHELINE_SIZE:
3796 Cache Line Size of the CPU.
3798 - CONFIG_SYS_DEFAULT_IMMR:
3799 Default address of the IMMR after system reset.
3801 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3802 and RPXsuper) to be able to adjust the position of
3803 the IMMR register after a reset.
3805 - CONFIG_SYS_CCSRBAR_DEFAULT:
3806 Default (power-on reset) physical address of CCSR on Freescale
3809 - CONFIG_SYS_CCSRBAR:
3810 Virtual address of CCSR. On a 32-bit build, this is typically
3811 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3813 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3814 for cross-platform code that uses that macro instead.
3816 - CONFIG_SYS_CCSRBAR_PHYS:
3817 Physical address of CCSR. CCSR can be relocated to a new
3818 physical address, if desired. In this case, this macro should
3819 be set to that address. Otherwise, it should be set to the
3820 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3821 is typically relocated on 36-bit builds. It is recommended
3822 that this macro be defined via the _HIGH and _LOW macros:
3824 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3825 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3827 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3828 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3829 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3830 used in assembly code, so it must not contain typecasts or
3831 integer size suffixes (e.g. "ULL").
3833 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3834 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3835 used in assembly code, so it must not contain typecasts or
3836 integer size suffixes (e.g. "ULL").
3838 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3839 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3840 forced to a value that ensures that CCSR is not relocated.
3842 - Floppy Disk Support:
3843 CONFIG_SYS_FDC_DRIVE_NUMBER
3845 the default drive number (default value 0)
3847 CONFIG_SYS_ISA_IO_STRIDE
3849 defines the spacing between FDC chipset registers
3852 CONFIG_SYS_ISA_IO_OFFSET
3854 defines the offset of register from address. It
3855 depends on which part of the data bus is connected to
3856 the FDC chipset. (default value 0)
3858 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3859 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3862 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3863 fdc_hw_init() is called at the beginning of the FDC
3864 setup. fdc_hw_init() must be provided by the board
3865 source code. It is used to make hardware dependant
3869 Most IDE controllers were designed to be connected with PCI
3870 interface. Only few of them were designed for AHB interface.
3871 When software is doing ATA command and data transfer to
3872 IDE devices through IDE-AHB controller, some additional
3873 registers accessing to these kind of IDE-AHB controller
3876 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3877 DO NOT CHANGE unless you know exactly what you're
3878 doing! (11-4) [MPC8xx/82xx systems only]
3880 - CONFIG_SYS_INIT_RAM_ADDR:
3882 Start address of memory area that can be used for
3883 initial data and stack; please note that this must be
3884 writable memory that is working WITHOUT special
3885 initialization, i. e. you CANNOT use normal RAM which
3886 will become available only after programming the
3887 memory controller and running certain initialization
3890 U-Boot uses the following memory types:
3891 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3892 - MPC824X: data cache
3893 - PPC4xx: data cache
3895 - CONFIG_SYS_GBL_DATA_OFFSET:
3897 Offset of the initial data structure in the memory
3898 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3899 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3900 data is located at the end of the available space
3901 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3902 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3903 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3904 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3907 On the MPC824X (or other systems that use the data
3908 cache for initial memory) the address chosen for
3909 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3910 point to an otherwise UNUSED address space between
3911 the top of RAM and the start of the PCI space.
3913 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3915 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3917 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3919 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3921 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3923 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3925 - CONFIG_SYS_OR_TIMING_SDRAM:
3928 - CONFIG_SYS_MAMR_PTA:
3929 periodic timer for refresh
3931 - CONFIG_SYS_DER: Debug Event Register (37-47)
3933 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3934 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3935 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3936 CONFIG_SYS_BR1_PRELIM:
3937 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3939 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3940 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3941 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3942 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3944 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3945 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3946 Machine Mode Register and Memory Periodic Timer
3947 Prescaler definitions (SDRAM timing)
3949 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3950 enable I2C microcode relocation patch (MPC8xx);
3951 define relocation offset in DPRAM [DSP2]
3953 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3954 enable SMC microcode relocation patch (MPC8xx);
3955 define relocation offset in DPRAM [SMC1]
3957 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3958 enable SPI microcode relocation patch (MPC8xx);
3959 define relocation offset in DPRAM [SCC4]
3961 - CONFIG_SYS_USE_OSCCLK:
3962 Use OSCM clock mode on MBX8xx board. Be careful,
3963 wrong setting might damage your board. Read
3964 doc/README.MBX before setting this variable!
3966 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3967 Offset of the bootmode word in DPRAM used by post
3968 (Power On Self Tests). This definition overrides
3969 #define'd default value in commproc.h resp.
3972 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3973 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3974 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3975 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3976 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3977 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3978 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3979 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3980 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3982 - CONFIG_PCI_DISABLE_PCIE:
3983 Disable PCI-Express on systems where it is supported but not
3986 - CONFIG_PCI_ENUM_ONLY
3987 Only scan through and get the devices on the busses.
3988 Don't do any setup work, presumably because someone or
3989 something has already done it, and we don't need to do it
3990 a second time. Useful for platforms that are pre-booted
3991 by coreboot or similar.
3993 - CONFIG_PCI_INDIRECT_BRIDGE:
3994 Enable support for indirect PCI bridges.
3997 Chip has SRIO or not
4000 Board has SRIO 1 port available
4003 Board has SRIO 2 port available
4005 - CONFIG_SRIO_PCIE_BOOT_MASTER
4006 Board can support master function for Boot from SRIO and PCIE
4008 - CONFIG_SYS_SRIOn_MEM_VIRT:
4009 Virtual Address of SRIO port 'n' memory region
4011 - CONFIG_SYS_SRIOn_MEM_PHYS:
4012 Physical Address of SRIO port 'n' memory region
4014 - CONFIG_SYS_SRIOn_MEM_SIZE:
4015 Size of SRIO port 'n' memory region
4017 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4018 Defined to tell the NAND controller that the NAND chip is using
4020 Not all NAND drivers use this symbol.
4021 Example of drivers that use it:
4022 - drivers/mtd/nand/ndfc.c
4023 - drivers/mtd/nand/mxc_nand.c
4025 - CONFIG_SYS_NDFC_EBC0_CFG
4026 Sets the EBC0_CFG register for the NDFC. If not defined
4027 a default value will be used.
4030 Get DDR timing information from an I2C EEPROM. Common
4031 with pluggable memory modules such as SODIMMs
4034 I2C address of the SPD EEPROM
4036 - CONFIG_SYS_SPD_BUS_NUM
4037 If SPD EEPROM is on an I2C bus other than the first
4038 one, specify here. Note that the value must resolve
4039 to something your driver can deal with.
4041 - CONFIG_SYS_DDR_RAW_TIMING
4042 Get DDR timing information from other than SPD. Common with
4043 soldered DDR chips onboard without SPD. DDR raw timing
4044 parameters are extracted from datasheet and hard-coded into
4045 header files or board specific files.
4047 - CONFIG_FSL_DDR_INTERACTIVE
4048 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4050 - CONFIG_SYS_83XX_DDR_USES_CS0
4051 Only for 83xx systems. If specified, then DDR should
4052 be configured using CS0 and CS1 instead of CS2 and CS3.
4054 - CONFIG_ETHER_ON_FEC[12]
4055 Define to enable FEC[12] on a 8xx series processor.
4057 - CONFIG_FEC[12]_PHY
4058 Define to the hardcoded PHY address which corresponds
4059 to the given FEC; i. e.
4060 #define CONFIG_FEC1_PHY 4
4061 means that the PHY with address 4 is connected to FEC1
4063 When set to -1, means to probe for first available.
4065 - CONFIG_FEC[12]_PHY_NORXERR
4066 The PHY does not have a RXERR line (RMII only).
4067 (so program the FEC to ignore it).
4070 Enable RMII mode for all FECs.
4071 Note that this is a global option, we can't
4072 have one FEC in standard MII mode and another in RMII mode.
4074 - CONFIG_CRC32_VERIFY
4075 Add a verify option to the crc32 command.
4078 => crc32 -v <address> <count> <crc32>
4080 Where address/count indicate a memory area
4081 and crc32 is the correct crc32 which the
4085 Add the "loopw" memory command. This only takes effect if
4086 the memory commands are activated globally (CONFIG_CMD_MEM).
4089 Add the "mdc" and "mwc" memory commands. These are cyclic
4094 This command will print 4 bytes (10,11,12,13) each 500 ms.
4096 => mwc.l 100 12345678 10
4097 This command will write 12345678 to address 100 all 10 ms.
4099 This only takes effect if the memory commands are activated
4100 globally (CONFIG_CMD_MEM).
4102 - CONFIG_SKIP_LOWLEVEL_INIT
4103 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4104 low level initializations (like setting up the memory
4105 controller) are omitted and/or U-Boot does not
4106 relocate itself into RAM.
4108 Normally this variable MUST NOT be defined. The only
4109 exception is when U-Boot is loaded (to RAM) by some
4110 other boot loader or by a debugger which performs
4111 these initializations itself.
4114 Modifies the behaviour of start.S when compiling a loader
4115 that is executed before the actual U-Boot. E.g. when
4116 compiling a NAND SPL.
4118 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4119 Only for 85xx systems. If this variable is specified, the section
4120 .resetvec is not kept and the section .bootpg is placed in the
4121 previous 4k of the .text section.
4123 - CONFIG_ARCH_MAP_SYSMEM
4124 Generally U-Boot (and in particular the md command) uses
4125 effective address. It is therefore not necessary to regard
4126 U-Boot address as virtual addresses that need to be translated
4127 to physical addresses. However, sandbox requires this, since
4128 it maintains its own little RAM buffer which contains all
4129 addressable memory. This option causes some memory accesses
4130 to be mapped through map_sysmem() / unmap_sysmem().
4132 - CONFIG_USE_ARCH_MEMCPY
4133 CONFIG_USE_ARCH_MEMSET
4134 If these options are used a optimized version of memcpy/memset will
4135 be used if available. These functions may be faster under some
4136 conditions but may increase the binary size.
4138 - CONFIG_X86_RESET_VECTOR
4139 If defined, the x86 reset vector code is included. This is not
4140 needed when U-Boot is running from Coreboot.
4143 Defines the MPU clock speed (in MHz).
4145 NOTE : currently only supported on AM335x platforms.
4147 Freescale QE/FMAN Firmware Support:
4148 -----------------------------------
4150 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4151 loading of "firmware", which is encoded in the QE firmware binary format.
4152 This firmware often needs to be loaded during U-Boot booting, so macros
4153 are used to identify the storage device (NOR flash, SPI, etc) and the address
4156 - CONFIG_SYS_QE_FMAN_FW_ADDR
4157 The address in the storage device where the firmware is located. The
4158 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4161 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4162 The maximum possible size of the firmware. The firmware binary format
4163 has a field that specifies the actual size of the firmware, but it
4164 might not be possible to read any part of the firmware unless some
4165 local storage is allocated to hold the entire firmware first.
4167 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4168 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4169 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4170 virtual address in NOR flash.
4172 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4173 Specifies that QE/FMAN firmware is located in NAND flash.
4174 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4176 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4177 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4178 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4180 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4181 Specifies that QE/FMAN firmware is located on the primary SPI
4182 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4184 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4185 Specifies that QE/FMAN firmware is located in the remote (master)
4186 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4187 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4188 window->master inbound window->master LAW->the ucode address in
4189 master's memory space.
4191 Building the Software:
4192 ======================
4194 Building U-Boot has been tested in several native build environments
4195 and in many different cross environments. Of course we cannot support
4196 all possibly existing versions of cross development tools in all
4197 (potentially obsolete) versions. In case of tool chain problems we
4198 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4199 which is extensively used to build and test U-Boot.
4201 If you are not using a native environment, it is assumed that you
4202 have GNU cross compiling tools available in your path. In this case,
4203 you must set the environment variable CROSS_COMPILE in your shell.
4204 Note that no changes to the Makefile or any other source files are
4205 necessary. For example using the ELDK on a 4xx CPU, please enter:
4207 $ CROSS_COMPILE=ppc_4xx-
4208 $ export CROSS_COMPILE
4210 Note: If you wish to generate Windows versions of the utilities in
4211 the tools directory you can use the MinGW toolchain
4212 (http://www.mingw.org). Set your HOST tools to the MinGW
4213 toolchain and execute 'make tools'. For example:
4215 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4217 Binaries such as tools/mkimage.exe will be created which can
4218 be executed on computers running Windows.
4220 U-Boot is intended to be simple to build. After installing the
4221 sources you must configure U-Boot for one specific board type. This
4226 where "NAME_config" is the name of one of the existing configu-
4227 rations; see boards.cfg for supported names.
4229 Note: for some board special configuration names may exist; check if
4230 additional information is available from the board vendor; for
4231 instance, the TQM823L systems are available without (standard)
4232 or with LCD support. You can select such additional "features"
4233 when choosing the configuration, i. e.
4236 - will configure for a plain TQM823L, i. e. no LCD support
4238 make TQM823L_LCD_config
4239 - will configure for a TQM823L with U-Boot console on LCD
4244 Finally, type "make all", and you should get some working U-Boot
4245 images ready for download to / installation on your system:
4247 - "u-boot.bin" is a raw binary image
4248 - "u-boot" is an image in ELF binary format
4249 - "u-boot.srec" is in Motorola S-Record format
4251 By default the build is performed locally and the objects are saved
4252 in the source directory. One of the two methods can be used to change
4253 this behavior and build U-Boot to some external directory:
4255 1. Add O= to the make command line invocations:
4257 make O=/tmp/build distclean
4258 make O=/tmp/build NAME_config
4259 make O=/tmp/build all
4261 2. Set environment variable BUILD_DIR to point to the desired location:
4263 export BUILD_DIR=/tmp/build
4268 Note that the command line "O=" setting overrides the BUILD_DIR environment
4272 Please be aware that the Makefiles assume you are using GNU make, so
4273 for instance on NetBSD you might need to use "gmake" instead of
4277 If the system board that you have is not listed, then you will need
4278 to port U-Boot to your hardware platform. To do this, follow these
4281 1. Add a new configuration option for your board to the toplevel
4282 "boards.cfg" file, using the existing entries as examples.
4283 Follow the instructions there to keep the boards in order.
4284 2. Create a new directory to hold your board specific code. Add any
4285 files you need. In your board directory, you will need at least
4286 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4287 3. Create a new configuration file "include/configs/<board>.h" for
4289 3. If you're porting U-Boot to a new CPU, then also create a new
4290 directory to hold your CPU specific code. Add any files you need.
4291 4. Run "make <board>_config" with your new name.
4292 5. Type "make", and you should get a working "u-boot.srec" file
4293 to be installed on your target system.
4294 6. Debug and solve any problems that might arise.
4295 [Of course, this last step is much harder than it sounds.]
4298 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4299 ==============================================================
4301 If you have modified U-Boot sources (for instance added a new board
4302 or support for new devices, a new CPU, etc.) you are expected to
4303 provide feedback to the other developers. The feedback normally takes
4304 the form of a "patch", i. e. a context diff against a certain (latest
4305 official or latest in the git repository) version of U-Boot sources.
4307 But before you submit such a patch, please verify that your modifi-
4308 cation did not break existing code. At least make sure that *ALL* of
4309 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4310 just run the "MAKEALL" script, which will configure and build U-Boot
4311 for ALL supported system. Be warned, this will take a while. You can
4312 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4313 environment variable to the script, i. e. to use the ELDK cross tools
4316 CROSS_COMPILE=ppc_8xx- MAKEALL
4318 or to build on a native PowerPC system you can type
4320 CROSS_COMPILE=' ' MAKEALL
4322 When using the MAKEALL script, the default behaviour is to build
4323 U-Boot in the source directory. This location can be changed by
4324 setting the BUILD_DIR environment variable. Also, for each target
4325 built, the MAKEALL script saves two log files (<target>.ERR and
4326 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4327 location can be changed by setting the MAKEALL_LOGDIR environment
4328 variable. For example:
4330 export BUILD_DIR=/tmp/build
4331 export MAKEALL_LOGDIR=/tmp/log
4332 CROSS_COMPILE=ppc_8xx- MAKEALL
4334 With the above settings build objects are saved in the /tmp/build,
4335 log files are saved in the /tmp/log and the source tree remains clean
4336 during the whole build process.
4339 See also "U-Boot Porting Guide" below.
4342 Monitor Commands - Overview:
4343 ============================
4345 go - start application at address 'addr'
4346 run - run commands in an environment variable
4347 bootm - boot application image from memory
4348 bootp - boot image via network using BootP/TFTP protocol
4349 bootz - boot zImage from memory
4350 tftpboot- boot image via network using TFTP protocol
4351 and env variables "ipaddr" and "serverip"
4352 (and eventually "gatewayip")
4353 tftpput - upload a file via network using TFTP protocol
4354 rarpboot- boot image via network using RARP/TFTP protocol
4355 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4356 loads - load S-Record file over serial line
4357 loadb - load binary file over serial line (kermit mode)
4359 mm - memory modify (auto-incrementing)
4360 nm - memory modify (constant address)
4361 mw - memory write (fill)
4363 cmp - memory compare
4364 crc32 - checksum calculation
4365 i2c - I2C sub-system
4366 sspi - SPI utility commands
4367 base - print or set address offset
4368 printenv- print environment variables
4369 setenv - set environment variables
4370 saveenv - save environment variables to persistent storage
4371 protect - enable or disable FLASH write protection
4372 erase - erase FLASH memory
4373 flinfo - print FLASH memory information
4374 nand - NAND memory operations (see doc/README.nand)
4375 bdinfo - print Board Info structure
4376 iminfo - print header information for application image
4377 coninfo - print console devices and informations
4378 ide - IDE sub-system
4379 loop - infinite loop on address range
4380 loopw - infinite write loop on address range
4381 mtest - simple RAM test
4382 icache - enable or disable instruction cache
4383 dcache - enable or disable data cache
4384 reset - Perform RESET of the CPU
4385 echo - echo args to console
4386 version - print monitor version
4387 help - print online help
4388 ? - alias for 'help'
4391 Monitor Commands - Detailed Description:
4392 ========================================
4396 For now: just type "help <command>".
4399 Environment Variables:
4400 ======================
4402 U-Boot supports user configuration using Environment Variables which
4403 can be made persistent by saving to Flash memory.
4405 Environment Variables are set using "setenv", printed using
4406 "printenv", and saved to Flash using "saveenv". Using "setenv"
4407 without a value can be used to delete a variable from the
4408 environment. As long as you don't save the environment you are
4409 working with an in-memory copy. In case the Flash area containing the
4410 environment is erased by accident, a default environment is provided.
4412 Some configuration options can be set using Environment Variables.
4414 List of environment variables (most likely not complete):
4416 baudrate - see CONFIG_BAUDRATE
4418 bootdelay - see CONFIG_BOOTDELAY
4420 bootcmd - see CONFIG_BOOTCOMMAND
4422 bootargs - Boot arguments when booting an RTOS image
4424 bootfile - Name of the image to load with TFTP
4426 bootm_low - Memory range available for image processing in the bootm
4427 command can be restricted. This variable is given as
4428 a hexadecimal number and defines lowest address allowed
4429 for use by the bootm command. See also "bootm_size"
4430 environment variable. Address defined by "bootm_low" is
4431 also the base of the initial memory mapping for the Linux
4432 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4435 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4436 This variable is given as a hexadecimal number and it
4437 defines the size of the memory region starting at base
4438 address bootm_low that is accessible by the Linux kernel
4439 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4440 as the default value if it is defined, and bootm_size is
4443 bootm_size - Memory range available for image processing in the bootm
4444 command can be restricted. This variable is given as
4445 a hexadecimal number and defines the size of the region
4446 allowed for use by the bootm command. See also "bootm_low"
4447 environment variable.
4449 updatefile - Location of the software update file on a TFTP server, used
4450 by the automatic software update feature. Please refer to
4451 documentation in doc/README.update for more details.
4453 autoload - if set to "no" (any string beginning with 'n'),
4454 "bootp" will just load perform a lookup of the
4455 configuration from the BOOTP server, but not try to
4456 load any image using TFTP
4458 autostart - if set to "yes", an image loaded using the "bootp",
4459 "rarpboot", "tftpboot" or "diskboot" commands will
4460 be automatically started (by internally calling
4463 If set to "no", a standalone image passed to the
4464 "bootm" command will be copied to the load address
4465 (and eventually uncompressed), but NOT be started.
4466 This can be used to load and uncompress arbitrary
4469 fdt_high - if set this restricts the maximum address that the
4470 flattened device tree will be copied into upon boot.
4471 For example, if you have a system with 1 GB memory
4472 at physical address 0x10000000, while Linux kernel
4473 only recognizes the first 704 MB as low memory, you
4474 may need to set fdt_high as 0x3C000000 to have the
4475 device tree blob be copied to the maximum address
4476 of the 704 MB low memory, so that Linux kernel can
4477 access it during the boot procedure.
4479 If this is set to the special value 0xFFFFFFFF then
4480 the fdt will not be copied at all on boot. For this
4481 to work it must reside in writable memory, have
4482 sufficient padding on the end of it for u-boot to
4483 add the information it needs into it, and the memory
4484 must be accessible by the kernel.
4486 fdtcontroladdr- if set this is the address of the control flattened
4487 device tree used by U-Boot when CONFIG_OF_CONTROL is
4490 i2cfast - (PPC405GP|PPC405EP only)
4491 if set to 'y' configures Linux I2C driver for fast
4492 mode (400kHZ). This environment variable is used in
4493 initialization code. So, for changes to be effective
4494 it must be saved and board must be reset.
4496 initrd_high - restrict positioning of initrd images:
4497 If this variable is not set, initrd images will be
4498 copied to the highest possible address in RAM; this
4499 is usually what you want since it allows for
4500 maximum initrd size. If for some reason you want to
4501 make sure that the initrd image is loaded below the
4502 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4503 variable to a value of "no" or "off" or "0".
4504 Alternatively, you can set it to a maximum upper
4505 address to use (U-Boot will still check that it
4506 does not overwrite the U-Boot stack and data).
4508 For instance, when you have a system with 16 MB
4509 RAM, and want to reserve 4 MB from use by Linux,
4510 you can do this by adding "mem=12M" to the value of
4511 the "bootargs" variable. However, now you must make
4512 sure that the initrd image is placed in the first
4513 12 MB as well - this can be done with
4515 setenv initrd_high 00c00000
4517 If you set initrd_high to 0xFFFFFFFF, this is an
4518 indication to U-Boot that all addresses are legal
4519 for the Linux kernel, including addresses in flash
4520 memory. In this case U-Boot will NOT COPY the
4521 ramdisk at all. This may be useful to reduce the
4522 boot time on your system, but requires that this
4523 feature is supported by your Linux kernel.
4525 ipaddr - IP address; needed for tftpboot command
4527 loadaddr - Default load address for commands like "bootp",
4528 "rarpboot", "tftpboot", "loadb" or "diskboot"
4530 loads_echo - see CONFIG_LOADS_ECHO
4532 serverip - TFTP server IP address; needed for tftpboot command
4534 bootretry - see CONFIG_BOOT_RETRY_TIME
4536 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4538 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4540 ethprime - controls which interface is used first.
4542 ethact - controls which interface is currently active.
4543 For example you can do the following
4545 => setenv ethact FEC
4546 => ping 192.168.0.1 # traffic sent on FEC
4547 => setenv ethact SCC
4548 => ping 10.0.0.1 # traffic sent on SCC
4550 ethrotate - When set to "no" U-Boot does not go through all
4551 available network interfaces.
4552 It just stays at the currently selected interface.
4554 netretry - When set to "no" each network operation will
4555 either succeed or fail without retrying.
4556 When set to "once" the network operation will
4557 fail when all the available network interfaces
4558 are tried once without success.
4559 Useful on scripts which control the retry operation
4562 npe_ucode - set load address for the NPE microcode
4564 tftpsrcport - If this is set, the value is used for TFTP's
4567 tftpdstport - If this is set, the value is used for TFTP's UDP
4568 destination port instead of the Well Know Port 69.
4570 tftpblocksize - Block size to use for TFTP transfers; if not set,
4571 we use the TFTP server's default block size
4573 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4574 seconds, minimum value is 1000 = 1 second). Defines
4575 when a packet is considered to be lost so it has to
4576 be retransmitted. The default is 5000 = 5 seconds.
4577 Lowering this value may make downloads succeed
4578 faster in networks with high packet loss rates or
4579 with unreliable TFTP servers.
4581 vlan - When set to a value < 4095 the traffic over
4582 Ethernet is encapsulated/received over 802.1q
4585 The following image location variables contain the location of images
4586 used in booting. The "Image" column gives the role of the image and is
4587 not an environment variable name. The other columns are environment
4588 variable names. "File Name" gives the name of the file on a TFTP
4589 server, "RAM Address" gives the location in RAM the image will be
4590 loaded to, and "Flash Location" gives the image's address in NOR
4591 flash or offset in NAND flash.
4593 *Note* - these variables don't have to be defined for all boards, some
4594 boards currenlty use other variables for these purposes, and some
4595 boards use these variables for other purposes.
4597 Image File Name RAM Address Flash Location
4598 ----- --------- ----------- --------------
4599 u-boot u-boot u-boot_addr_r u-boot_addr
4600 Linux kernel bootfile kernel_addr_r kernel_addr
4601 device tree blob fdtfile fdt_addr_r fdt_addr
4602 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4604 The following environment variables may be used and automatically
4605 updated by the network boot commands ("bootp" and "rarpboot"),
4606 depending the information provided by your boot server:
4608 bootfile - see above
4609 dnsip - IP address of your Domain Name Server
4610 dnsip2 - IP address of your secondary Domain Name Server
4611 gatewayip - IP address of the Gateway (Router) to use
4612 hostname - Target hostname
4614 netmask - Subnet Mask
4615 rootpath - Pathname of the root filesystem on the NFS server
4616 serverip - see above
4619 There are two special Environment Variables:
4621 serial# - contains hardware identification information such
4622 as type string and/or serial number
4623 ethaddr - Ethernet address
4625 These variables can be set only once (usually during manufacturing of
4626 the board). U-Boot refuses to delete or overwrite these variables
4627 once they have been set once.
4630 Further special Environment Variables:
4632 ver - Contains the U-Boot version string as printed
4633 with the "version" command. This variable is
4634 readonly (see CONFIG_VERSION_VARIABLE).
4637 Please note that changes to some configuration parameters may take
4638 only effect after the next boot (yes, that's just like Windoze :-).
4641 Callback functions for environment variables:
4642 ---------------------------------------------
4644 For some environment variables, the behavior of u-boot needs to change
4645 when their values are changed. This functionailty allows functions to
4646 be associated with arbitrary variables. On creation, overwrite, or
4647 deletion, the callback will provide the opportunity for some side
4648 effect to happen or for the change to be rejected.
4650 The callbacks are named and associated with a function using the
4651 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4653 These callbacks are associated with variables in one of two ways. The
4654 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4655 in the board configuration to a string that defines a list of
4656 associations. The list must be in the following format:
4658 entry = variable_name[:callback_name]
4661 If the callback name is not specified, then the callback is deleted.
4662 Spaces are also allowed anywhere in the list.
4664 Callbacks can also be associated by defining the ".callbacks" variable
4665 with the same list format above. Any association in ".callbacks" will
4666 override any association in the static list. You can define
4667 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4668 ".callbacks" envirnoment variable in the default or embedded environment.
4671 Command Line Parsing:
4672 =====================
4674 There are two different command line parsers available with U-Boot:
4675 the old "simple" one, and the much more powerful "hush" shell:
4677 Old, simple command line parser:
4678 --------------------------------
4680 - supports environment variables (through setenv / saveenv commands)
4681 - several commands on one line, separated by ';'
4682 - variable substitution using "... ${name} ..." syntax
4683 - special characters ('$', ';') can be escaped by prefixing with '\',
4685 setenv bootcmd bootm \${address}
4686 - You can also escape text by enclosing in single apostrophes, for example:
4687 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4692 - similar to Bourne shell, with control structures like
4693 if...then...else...fi, for...do...done; while...do...done,
4694 until...do...done, ...
4695 - supports environment ("global") variables (through setenv / saveenv
4696 commands) and local shell variables (through standard shell syntax
4697 "name=value"); only environment variables can be used with "run"
4703 (1) If a command line (or an environment variable executed by a "run"
4704 command) contains several commands separated by semicolon, and
4705 one of these commands fails, then the remaining commands will be
4708 (2) If you execute several variables with one call to run (i. e.
4709 calling run with a list of variables as arguments), any failing
4710 command will cause "run" to terminate, i. e. the remaining
4711 variables are not executed.
4713 Note for Redundant Ethernet Interfaces:
4714 =======================================
4716 Some boards come with redundant Ethernet interfaces; U-Boot supports
4717 such configurations and is capable of automatic selection of a
4718 "working" interface when needed. MAC assignment works as follows:
4720 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4721 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4722 "eth1addr" (=>eth1), "eth2addr", ...
4724 If the network interface stores some valid MAC address (for instance
4725 in SROM), this is used as default address if there is NO correspon-
4726 ding setting in the environment; if the corresponding environment
4727 variable is set, this overrides the settings in the card; that means:
4729 o If the SROM has a valid MAC address, and there is no address in the
4730 environment, the SROM's address is used.
4732 o If there is no valid address in the SROM, and a definition in the
4733 environment exists, then the value from the environment variable is
4736 o If both the SROM and the environment contain a MAC address, and
4737 both addresses are the same, this MAC address is used.
4739 o If both the SROM and the environment contain a MAC address, and the
4740 addresses differ, the value from the environment is used and a
4743 o If neither SROM nor the environment contain a MAC address, an error
4746 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4747 will be programmed into hardware as part of the initialization process. This
4748 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4749 The naming convention is as follows:
4750 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4755 U-Boot is capable of booting (and performing other auxiliary operations on)
4756 images in two formats:
4758 New uImage format (FIT)
4759 -----------------------
4761 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4762 to Flattened Device Tree). It allows the use of images with multiple
4763 components (several kernels, ramdisks, etc.), with contents protected by
4764 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4770 Old image format is based on binary files which can be basically anything,
4771 preceded by a special header; see the definitions in include/image.h for
4772 details; basically, the header defines the following image properties:
4774 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4775 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4776 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4777 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4779 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4780 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4781 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4782 * Compression Type (uncompressed, gzip, bzip2)
4788 The header is marked by a special Magic Number, and both the header
4789 and the data portions of the image are secured against corruption by
4796 Although U-Boot should support any OS or standalone application
4797 easily, the main focus has always been on Linux during the design of
4800 U-Boot includes many features that so far have been part of some
4801 special "boot loader" code within the Linux kernel. Also, any
4802 "initrd" images to be used are no longer part of one big Linux image;
4803 instead, kernel and "initrd" are separate images. This implementation
4804 serves several purposes:
4806 - the same features can be used for other OS or standalone
4807 applications (for instance: using compressed images to reduce the
4808 Flash memory footprint)
4810 - it becomes much easier to port new Linux kernel versions because
4811 lots of low-level, hardware dependent stuff are done by U-Boot
4813 - the same Linux kernel image can now be used with different "initrd"
4814 images; of course this also means that different kernel images can
4815 be run with the same "initrd". This makes testing easier (you don't
4816 have to build a new "zImage.initrd" Linux image when you just
4817 change a file in your "initrd"). Also, a field-upgrade of the
4818 software is easier now.
4824 Porting Linux to U-Boot based systems:
4825 ---------------------------------------
4827 U-Boot cannot save you from doing all the necessary modifications to
4828 configure the Linux device drivers for use with your target hardware
4829 (no, we don't intend to provide a full virtual machine interface to
4832 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4834 Just make sure your machine specific header file (for instance
4835 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4836 Information structure as we define in include/asm-<arch>/u-boot.h,
4837 and make sure that your definition of IMAP_ADDR uses the same value
4838 as your U-Boot configuration in CONFIG_SYS_IMMR.
4841 Configuring the Linux kernel:
4842 -----------------------------
4844 No specific requirements for U-Boot. Make sure you have some root
4845 device (initial ramdisk, NFS) for your target system.
4848 Building a Linux Image:
4849 -----------------------
4851 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4852 not used. If you use recent kernel source, a new build target
4853 "uImage" will exist which automatically builds an image usable by
4854 U-Boot. Most older kernels also have support for a "pImage" target,
4855 which was introduced for our predecessor project PPCBoot and uses a
4856 100% compatible format.
4865 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4866 encapsulate a compressed Linux kernel image with header information,
4867 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4869 * build a standard "vmlinux" kernel image (in ELF binary format):
4871 * convert the kernel into a raw binary image:
4873 ${CROSS_COMPILE}-objcopy -O binary \
4874 -R .note -R .comment \
4875 -S vmlinux linux.bin
4877 * compress the binary image:
4881 * package compressed binary image for U-Boot:
4883 mkimage -A ppc -O linux -T kernel -C gzip \
4884 -a 0 -e 0 -n "Linux Kernel Image" \
4885 -d linux.bin.gz uImage
4888 The "mkimage" tool can also be used to create ramdisk images for use
4889 with U-Boot, either separated from the Linux kernel image, or
4890 combined into one file. "mkimage" encapsulates the images with a 64
4891 byte header containing information about target architecture,
4892 operating system, image type, compression method, entry points, time
4893 stamp, CRC32 checksums, etc.
4895 "mkimage" can be called in two ways: to verify existing images and
4896 print the header information, or to build new images.
4898 In the first form (with "-l" option) mkimage lists the information
4899 contained in the header of an existing U-Boot image; this includes
4900 checksum verification:
4902 tools/mkimage -l image
4903 -l ==> list image header information
4905 The second form (with "-d" option) is used to build a U-Boot image
4906 from a "data file" which is used as image payload:
4908 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4909 -n name -d data_file image
4910 -A ==> set architecture to 'arch'
4911 -O ==> set operating system to 'os'
4912 -T ==> set image type to 'type'
4913 -C ==> set compression type 'comp'
4914 -a ==> set load address to 'addr' (hex)
4915 -e ==> set entry point to 'ep' (hex)
4916 -n ==> set image name to 'name'
4917 -d ==> use image data from 'datafile'
4919 Right now, all Linux kernels for PowerPC systems use the same load
4920 address (0x00000000), but the entry point address depends on the
4923 - 2.2.x kernels have the entry point at 0x0000000C,
4924 - 2.3.x and later kernels have the entry point at 0x00000000.
4926 So a typical call to build a U-Boot image would read:
4928 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4929 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4930 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4931 > examples/uImage.TQM850L
4932 Image Name: 2.4.4 kernel for TQM850L
4933 Created: Wed Jul 19 02:34:59 2000
4934 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4935 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4936 Load Address: 0x00000000
4937 Entry Point: 0x00000000
4939 To verify the contents of the image (or check for corruption):
4941 -> tools/mkimage -l examples/uImage.TQM850L
4942 Image Name: 2.4.4 kernel for TQM850L
4943 Created: Wed Jul 19 02:34:59 2000
4944 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4945 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4946 Load Address: 0x00000000
4947 Entry Point: 0x00000000
4949 NOTE: for embedded systems where boot time is critical you can trade
4950 speed for memory and install an UNCOMPRESSED image instead: this
4951 needs more space in Flash, but boots much faster since it does not
4952 need to be uncompressed:
4954 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4955 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4956 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4957 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4958 > examples/uImage.TQM850L-uncompressed
4959 Image Name: 2.4.4 kernel for TQM850L
4960 Created: Wed Jul 19 02:34:59 2000
4961 Image Type: PowerPC Linux Kernel Image (uncompressed)
4962 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4963 Load Address: 0x00000000
4964 Entry Point: 0x00000000
4967 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4968 when your kernel is intended to use an initial ramdisk:
4970 -> tools/mkimage -n 'Simple Ramdisk Image' \
4971 > -A ppc -O linux -T ramdisk -C gzip \
4972 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4973 Image Name: Simple Ramdisk Image
4974 Created: Wed Jan 12 14:01:50 2000
4975 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4976 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4977 Load Address: 0x00000000
4978 Entry Point: 0x00000000
4981 Installing a Linux Image:
4982 -------------------------
4984 To downloading a U-Boot image over the serial (console) interface,
4985 you must convert the image to S-Record format:
4987 objcopy -I binary -O srec examples/image examples/image.srec
4989 The 'objcopy' does not understand the information in the U-Boot
4990 image header, so the resulting S-Record file will be relative to
4991 address 0x00000000. To load it to a given address, you need to
4992 specify the target address as 'offset' parameter with the 'loads'
4995 Example: install the image to address 0x40100000 (which on the
4996 TQM8xxL is in the first Flash bank):
4998 => erase 40100000 401FFFFF
5004 ## Ready for S-Record download ...
5005 ~>examples/image.srec
5006 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5008 15989 15990 15991 15992
5009 [file transfer complete]
5011 ## Start Addr = 0x00000000
5014 You can check the success of the download using the 'iminfo' command;
5015 this includes a checksum verification so you can be sure no data
5016 corruption happened:
5020 ## Checking Image at 40100000 ...
5021 Image Name: 2.2.13 for initrd on TQM850L
5022 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5023 Data Size: 335725 Bytes = 327 kB = 0 MB
5024 Load Address: 00000000
5025 Entry Point: 0000000c
5026 Verifying Checksum ... OK
5032 The "bootm" command is used to boot an application that is stored in
5033 memory (RAM or Flash). In case of a Linux kernel image, the contents
5034 of the "bootargs" environment variable is passed to the kernel as
5035 parameters. You can check and modify this variable using the
5036 "printenv" and "setenv" commands:
5039 => printenv bootargs
5040 bootargs=root=/dev/ram
5042 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5044 => printenv bootargs
5045 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5048 ## Booting Linux kernel at 40020000 ...
5049 Image Name: 2.2.13 for NFS on TQM850L
5050 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5051 Data Size: 381681 Bytes = 372 kB = 0 MB
5052 Load Address: 00000000
5053 Entry Point: 0000000c
5054 Verifying Checksum ... OK
5055 Uncompressing Kernel Image ... OK
5056 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
5057 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5058 time_init: decrementer frequency = 187500000/60
5059 Calibrating delay loop... 49.77 BogoMIPS
5060 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5063 If you want to boot a Linux kernel with initial RAM disk, you pass
5064 the memory addresses of both the kernel and the initrd image (PPBCOOT
5065 format!) to the "bootm" command:
5067 => imi 40100000 40200000
5069 ## Checking Image at 40100000 ...
5070 Image Name: 2.2.13 for initrd on TQM850L
5071 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5072 Data Size: 335725 Bytes = 327 kB = 0 MB
5073 Load Address: 00000000
5074 Entry Point: 0000000c
5075 Verifying Checksum ... OK
5077 ## Checking Image at 40200000 ...
5078 Image Name: Simple Ramdisk Image
5079 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5080 Data Size: 566530 Bytes = 553 kB = 0 MB
5081 Load Address: 00000000
5082 Entry Point: 00000000
5083 Verifying Checksum ... OK
5085 => bootm 40100000 40200000
5086 ## Booting Linux kernel at 40100000 ...
5087 Image Name: 2.2.13 for initrd on TQM850L
5088 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5089 Data Size: 335725 Bytes = 327 kB = 0 MB
5090 Load Address: 00000000
5091 Entry Point: 0000000c
5092 Verifying Checksum ... OK
5093 Uncompressing Kernel Image ... OK
5094 ## Loading RAMDisk Image at 40200000 ...
5095 Image Name: Simple Ramdisk Image
5096 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5097 Data Size: 566530 Bytes = 553 kB = 0 MB
5098 Load Address: 00000000
5099 Entry Point: 00000000
5100 Verifying Checksum ... OK
5101 Loading Ramdisk ... OK
5102 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
5103 Boot arguments: root=/dev/ram
5104 time_init: decrementer frequency = 187500000/60
5105 Calibrating delay loop... 49.77 BogoMIPS
5107 RAMDISK: Compressed image found at block 0
5108 VFS: Mounted root (ext2 filesystem).
5112 Boot Linux and pass a flat device tree:
5115 First, U-Boot must be compiled with the appropriate defines. See the section
5116 titled "Linux Kernel Interface" above for a more in depth explanation. The
5117 following is an example of how to start a kernel and pass an updated
5123 oft=oftrees/mpc8540ads.dtb
5124 => tftp $oftaddr $oft
5125 Speed: 1000, full duplex
5127 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5128 Filename 'oftrees/mpc8540ads.dtb'.
5129 Load address: 0x300000
5132 Bytes transferred = 4106 (100a hex)
5133 => tftp $loadaddr $bootfile
5134 Speed: 1000, full duplex
5136 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5138 Load address: 0x200000
5139 Loading:############
5141 Bytes transferred = 1029407 (fb51f hex)
5146 => bootm $loadaddr - $oftaddr
5147 ## Booting image at 00200000 ...
5148 Image Name: Linux-2.6.17-dirty
5149 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5150 Data Size: 1029343 Bytes = 1005.2 kB
5151 Load Address: 00000000
5152 Entry Point: 00000000
5153 Verifying Checksum ... OK
5154 Uncompressing Kernel Image ... OK
5155 Booting using flat device tree at 0x300000
5156 Using MPC85xx ADS machine description
5157 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5161 More About U-Boot Image Types:
5162 ------------------------------
5164 U-Boot supports the following image types:
5166 "Standalone Programs" are directly runnable in the environment
5167 provided by U-Boot; it is expected that (if they behave
5168 well) you can continue to work in U-Boot after return from
5169 the Standalone Program.
5170 "OS Kernel Images" are usually images of some Embedded OS which
5171 will take over control completely. Usually these programs
5172 will install their own set of exception handlers, device
5173 drivers, set up the MMU, etc. - this means, that you cannot
5174 expect to re-enter U-Boot except by resetting the CPU.
5175 "RAMDisk Images" are more or less just data blocks, and their
5176 parameters (address, size) are passed to an OS kernel that is
5178 "Multi-File Images" contain several images, typically an OS
5179 (Linux) kernel image and one or more data images like
5180 RAMDisks. This construct is useful for instance when you want
5181 to boot over the network using BOOTP etc., where the boot
5182 server provides just a single image file, but you want to get
5183 for instance an OS kernel and a RAMDisk image.
5185 "Multi-File Images" start with a list of image sizes, each
5186 image size (in bytes) specified by an "uint32_t" in network
5187 byte order. This list is terminated by an "(uint32_t)0".
5188 Immediately after the terminating 0 follow the images, one by
5189 one, all aligned on "uint32_t" boundaries (size rounded up to
5190 a multiple of 4 bytes).
5192 "Firmware Images" are binary images containing firmware (like
5193 U-Boot or FPGA images) which usually will be programmed to
5196 "Script files" are command sequences that will be executed by
5197 U-Boot's command interpreter; this feature is especially
5198 useful when you configure U-Boot to use a real shell (hush)
5199 as command interpreter.
5201 Booting the Linux zImage:
5202 -------------------------
5204 On some platforms, it's possible to boot Linux zImage. This is done
5205 using the "bootz" command. The syntax of "bootz" command is the same
5206 as the syntax of "bootm" command.
5208 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5209 kernel with raw initrd images. The syntax is slightly different, the
5210 address of the initrd must be augmented by it's size, in the following
5211 format: "<initrd addres>:<initrd size>".
5217 One of the features of U-Boot is that you can dynamically load and
5218 run "standalone" applications, which can use some resources of
5219 U-Boot like console I/O functions or interrupt services.
5221 Two simple examples are included with the sources:
5226 'examples/hello_world.c' contains a small "Hello World" Demo
5227 application; it is automatically compiled when you build U-Boot.
5228 It's configured to run at address 0x00040004, so you can play with it
5232 ## Ready for S-Record download ...
5233 ~>examples/hello_world.srec
5234 1 2 3 4 5 6 7 8 9 10 11 ...
5235 [file transfer complete]
5237 ## Start Addr = 0x00040004
5239 => go 40004 Hello World! This is a test.
5240 ## Starting application at 0x00040004 ...
5251 Hit any key to exit ...
5253 ## Application terminated, rc = 0x0
5255 Another example, which demonstrates how to register a CPM interrupt
5256 handler with the U-Boot code, can be found in 'examples/timer.c'.
5257 Here, a CPM timer is set up to generate an interrupt every second.
5258 The interrupt service routine is trivial, just printing a '.'
5259 character, but this is just a demo program. The application can be
5260 controlled by the following keys:
5262 ? - print current values og the CPM Timer registers
5263 b - enable interrupts and start timer
5264 e - stop timer and disable interrupts
5265 q - quit application
5268 ## Ready for S-Record download ...
5269 ~>examples/timer.srec
5270 1 2 3 4 5 6 7 8 9 10 11 ...
5271 [file transfer complete]
5273 ## Start Addr = 0x00040004
5276 ## Starting application at 0x00040004 ...
5279 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5282 [q, b, e, ?] Set interval 1000000 us
5285 [q, b, e, ?] ........
5286 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5289 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5292 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5295 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5297 [q, b, e, ?] ...Stopping timer
5299 [q, b, e, ?] ## Application terminated, rc = 0x0
5305 Over time, many people have reported problems when trying to use the
5306 "minicom" terminal emulation program for serial download. I (wd)
5307 consider minicom to be broken, and recommend not to use it. Under
5308 Unix, I recommend to use C-Kermit for general purpose use (and
5309 especially for kermit binary protocol download ("loadb" command), and
5310 use "cu" for S-Record download ("loads" command). See
5311 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5312 for help with kermit.
5315 Nevertheless, if you absolutely want to use it try adding this
5316 configuration to your "File transfer protocols" section:
5318 Name Program Name U/D FullScr IO-Red. Multi
5319 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5320 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5326 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5327 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5329 Building requires a cross environment; it is known to work on
5330 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5331 need gmake since the Makefiles are not compatible with BSD make).
5332 Note that the cross-powerpc package does not install include files;
5333 attempting to build U-Boot will fail because <machine/ansi.h> is
5334 missing. This file has to be installed and patched manually:
5336 # cd /usr/pkg/cross/powerpc-netbsd/include
5338 # ln -s powerpc machine
5339 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5340 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5342 Native builds *don't* work due to incompatibilities between native
5343 and U-Boot include files.
5345 Booting assumes that (the first part of) the image booted is a
5346 stage-2 loader which in turn loads and then invokes the kernel
5347 proper. Loader sources will eventually appear in the NetBSD source
5348 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5349 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5352 Implementation Internals:
5353 =========================
5355 The following is not intended to be a complete description of every
5356 implementation detail. However, it should help to understand the
5357 inner workings of U-Boot and make it easier to port it to custom
5361 Initial Stack, Global Data:
5362 ---------------------------
5364 The implementation of U-Boot is complicated by the fact that U-Boot
5365 starts running out of ROM (flash memory), usually without access to
5366 system RAM (because the memory controller is not initialized yet).
5367 This means that we don't have writable Data or BSS segments, and BSS
5368 is not initialized as zero. To be able to get a C environment working
5369 at all, we have to allocate at least a minimal stack. Implementation
5370 options for this are defined and restricted by the CPU used: Some CPU
5371 models provide on-chip memory (like the IMMR area on MPC8xx and
5372 MPC826x processors), on others (parts of) the data cache can be
5373 locked as (mis-) used as memory, etc.
5375 Chris Hallinan posted a good summary of these issues to the
5376 U-Boot mailing list:
5378 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5379 From: "Chris Hallinan" <clh@net1plus.com>
5380 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5383 Correct me if I'm wrong, folks, but the way I understand it
5384 is this: Using DCACHE as initial RAM for Stack, etc, does not
5385 require any physical RAM backing up the cache. The cleverness
5386 is that the cache is being used as a temporary supply of
5387 necessary storage before the SDRAM controller is setup. It's
5388 beyond the scope of this list to explain the details, but you
5389 can see how this works by studying the cache architecture and
5390 operation in the architecture and processor-specific manuals.
5392 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5393 is another option for the system designer to use as an
5394 initial stack/RAM area prior to SDRAM being available. Either
5395 option should work for you. Using CS 4 should be fine if your
5396 board designers haven't used it for something that would
5397 cause you grief during the initial boot! It is frequently not
5400 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5401 with your processor/board/system design. The default value
5402 you will find in any recent u-boot distribution in
5403 walnut.h should work for you. I'd set it to a value larger
5404 than your SDRAM module. If you have a 64MB SDRAM module, set
5405 it above 400_0000. Just make sure your board has no resources
5406 that are supposed to respond to that address! That code in
5407 start.S has been around a while and should work as is when
5408 you get the config right.
5413 It is essential to remember this, since it has some impact on the C
5414 code for the initialization procedures:
5416 * Initialized global data (data segment) is read-only. Do not attempt
5419 * Do not use any uninitialized global data (or implicitely initialized
5420 as zero data - BSS segment) at all - this is undefined, initiali-
5421 zation is performed later (when relocating to RAM).
5423 * Stack space is very limited. Avoid big data buffers or things like
5426 Having only the stack as writable memory limits means we cannot use
5427 normal global data to share information beween the code. But it
5428 turned out that the implementation of U-Boot can be greatly
5429 simplified by making a global data structure (gd_t) available to all
5430 functions. We could pass a pointer to this data as argument to _all_
5431 functions, but this would bloat the code. Instead we use a feature of
5432 the GCC compiler (Global Register Variables) to share the data: we
5433 place a pointer (gd) to the global data into a register which we
5434 reserve for this purpose.
5436 When choosing a register for such a purpose we are restricted by the
5437 relevant (E)ABI specifications for the current architecture, and by
5438 GCC's implementation.
5440 For PowerPC, the following registers have specific use:
5442 R2: reserved for system use
5443 R3-R4: parameter passing and return values
5444 R5-R10: parameter passing
5445 R13: small data area pointer
5449 (U-Boot also uses R12 as internal GOT pointer. r12
5450 is a volatile register so r12 needs to be reset when
5451 going back and forth between asm and C)
5453 ==> U-Boot will use R2 to hold a pointer to the global data
5455 Note: on PPC, we could use a static initializer (since the
5456 address of the global data structure is known at compile time),
5457 but it turned out that reserving a register results in somewhat
5458 smaller code - although the code savings are not that big (on
5459 average for all boards 752 bytes for the whole U-Boot image,
5460 624 text + 127 data).
5462 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5463 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5465 ==> U-Boot will use P3 to hold a pointer to the global data
5467 On ARM, the following registers are used:
5469 R0: function argument word/integer result
5470 R1-R3: function argument word
5472 R10: stack limit (used only if stack checking if enabled)
5473 R11: argument (frame) pointer
5474 R12: temporary workspace
5477 R15: program counter
5479 ==> U-Boot will use R8 to hold a pointer to the global data
5481 On Nios II, the ABI is documented here:
5482 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5484 ==> U-Boot will use gp to hold a pointer to the global data
5486 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5487 to access small data sections, so gp is free.
5489 On NDS32, the following registers are used:
5491 R0-R1: argument/return
5493 R15: temporary register for assembler
5494 R16: trampoline register
5495 R28: frame pointer (FP)
5496 R29: global pointer (GP)
5497 R30: link register (LP)
5498 R31: stack pointer (SP)
5499 PC: program counter (PC)
5501 ==> U-Boot will use R10 to hold a pointer to the global data
5503 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5504 or current versions of GCC may "optimize" the code too much.
5509 U-Boot runs in system state and uses physical addresses, i.e. the
5510 MMU is not used either for address mapping nor for memory protection.
5512 The available memory is mapped to fixed addresses using the memory
5513 controller. In this process, a contiguous block is formed for each
5514 memory type (Flash, SDRAM, SRAM), even when it consists of several
5515 physical memory banks.
5517 U-Boot is installed in the first 128 kB of the first Flash bank (on
5518 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5519 booting and sizing and initializing DRAM, the code relocates itself
5520 to the upper end of DRAM. Immediately below the U-Boot code some
5521 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5522 configuration setting]. Below that, a structure with global Board
5523 Info data is placed, followed by the stack (growing downward).
5525 Additionally, some exception handler code is copied to the low 8 kB
5526 of DRAM (0x00000000 ... 0x00001FFF).
5528 So a typical memory configuration with 16 MB of DRAM could look like
5531 0x0000 0000 Exception Vector code
5534 0x0000 2000 Free for Application Use
5540 0x00FB FF20 Monitor Stack (Growing downward)
5541 0x00FB FFAC Board Info Data and permanent copy of global data
5542 0x00FC 0000 Malloc Arena
5545 0x00FE 0000 RAM Copy of Monitor Code
5546 ... eventually: LCD or video framebuffer
5547 ... eventually: pRAM (Protected RAM - unchanged by reset)
5548 0x00FF FFFF [End of RAM]
5551 System Initialization:
5552 ----------------------
5554 In the reset configuration, U-Boot starts at the reset entry point
5555 (on most PowerPC systems at address 0x00000100). Because of the reset
5556 configuration for CS0# this is a mirror of the onboard Flash memory.
5557 To be able to re-map memory U-Boot then jumps to its link address.
5558 To be able to implement the initialization code in C, a (small!)
5559 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5560 which provide such a feature like MPC8xx or MPC8260), or in a locked
5561 part of the data cache. After that, U-Boot initializes the CPU core,
5562 the caches and the SIU.
5564 Next, all (potentially) available memory banks are mapped using a
5565 preliminary mapping. For example, we put them on 512 MB boundaries
5566 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5567 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5568 programmed for SDRAM access. Using the temporary configuration, a
5569 simple memory test is run that determines the size of the SDRAM
5572 When there is more than one SDRAM bank, and the banks are of
5573 different size, the largest is mapped first. For equal size, the first
5574 bank (CS2#) is mapped first. The first mapping is always for address
5575 0x00000000, with any additional banks following immediately to create
5576 contiguous memory starting from 0.
5578 Then, the monitor installs itself at the upper end of the SDRAM area
5579 and allocates memory for use by malloc() and for the global Board
5580 Info data; also, the exception vector code is copied to the low RAM
5581 pages, and the final stack is set up.
5583 Only after this relocation will you have a "normal" C environment;
5584 until that you are restricted in several ways, mostly because you are
5585 running from ROM, and because the code will have to be relocated to a
5589 U-Boot Porting Guide:
5590 ----------------------
5592 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5596 int main(int argc, char *argv[])
5598 sighandler_t no_more_time;
5600 signal(SIGALRM, no_more_time);
5601 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5603 if (available_money > available_manpower) {
5604 Pay consultant to port U-Boot;
5608 Download latest U-Boot source;
5610 Subscribe to u-boot mailing list;
5613 email("Hi, I am new to U-Boot, how do I get started?");
5616 Read the README file in the top level directory;
5617 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5618 Read applicable doc/*.README;
5619 Read the source, Luke;
5620 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5623 if (available_money > toLocalCurrency ($2500))
5626 Add a lot of aggravation and time;
5628 if (a similar board exists) { /* hopefully... */
5629 cp -a board/<similar> board/<myboard>
5630 cp include/configs/<similar>.h include/configs/<myboard>.h
5632 Create your own board support subdirectory;
5633 Create your own board include/configs/<myboard>.h file;
5635 Edit new board/<myboard> files
5636 Edit new include/configs/<myboard>.h
5641 Add / modify source code;
5645 email("Hi, I am having problems...");
5647 Send patch file to the U-Boot email list;
5648 if (reasonable critiques)
5649 Incorporate improvements from email list code review;
5651 Defend code as written;
5657 void no_more_time (int sig)
5666 All contributions to U-Boot should conform to the Linux kernel
5667 coding style; see the file "Documentation/CodingStyle" and the script
5668 "scripts/Lindent" in your Linux kernel source directory.
5670 Source files originating from a different project (for example the
5671 MTD subsystem) are generally exempt from these guidelines and are not
5672 reformated to ease subsequent migration to newer versions of those
5675 Please note that U-Boot is implemented in C (and to some small parts in
5676 Assembler); no C++ is used, so please do not use C++ style comments (//)
5679 Please also stick to the following formatting rules:
5680 - remove any trailing white space
5681 - use TAB characters for indentation and vertical alignment, not spaces
5682 - make sure NOT to use DOS '\r\n' line feeds
5683 - do not add more than 2 consecutive empty lines to source files
5684 - do not add trailing empty lines to source files
5686 Submissions which do not conform to the standards may be returned
5687 with a request to reformat the changes.
5693 Since the number of patches for U-Boot is growing, we need to
5694 establish some rules. Submissions which do not conform to these rules
5695 may be rejected, even when they contain important and valuable stuff.
5697 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5699 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5700 see http://lists.denx.de/mailman/listinfo/u-boot
5702 When you send a patch, please include the following information with
5705 * For bug fixes: a description of the bug and how your patch fixes
5706 this bug. Please try to include a way of demonstrating that the
5707 patch actually fixes something.
5709 * For new features: a description of the feature and your
5712 * A CHANGELOG entry as plaintext (separate from the patch)
5714 * For major contributions, your entry to the CREDITS file
5716 * When you add support for a new board, don't forget to add this
5717 board to the MAINTAINERS file, too.
5719 * If your patch adds new configuration options, don't forget to
5720 document these in the README file.
5722 * The patch itself. If you are using git (which is *strongly*
5723 recommended) you can easily generate the patch using the
5724 "git format-patch". If you then use "git send-email" to send it to
5725 the U-Boot mailing list, you will avoid most of the common problems
5726 with some other mail clients.
5728 If you cannot use git, use "diff -purN OLD NEW". If your version of
5729 diff does not support these options, then get the latest version of
5732 The current directory when running this command shall be the parent
5733 directory of the U-Boot source tree (i. e. please make sure that
5734 your patch includes sufficient directory information for the
5737 We prefer patches as plain text. MIME attachments are discouraged,
5738 and compressed attachments must not be used.
5740 * If one logical set of modifications affects or creates several
5741 files, all these changes shall be submitted in a SINGLE patch file.
5743 * Changesets that contain different, unrelated modifications shall be
5744 submitted as SEPARATE patches, one patch per changeset.
5749 * Before sending the patch, run the MAKEALL script on your patched
5750 source tree and make sure that no errors or warnings are reported
5751 for any of the boards.
5753 * Keep your modifications to the necessary minimum: A patch
5754 containing several unrelated changes or arbitrary reformats will be
5755 returned with a request to re-formatting / split it.
5757 * If you modify existing code, make sure that your new code does not
5758 add to the memory footprint of the code ;-) Small is beautiful!
5759 When adding new features, these should compile conditionally only
5760 (using #ifdef), and the resulting code with the new feature
5761 disabled must not need more memory than the old code without your
5764 * Remember that there is a size limit of 100 kB per message on the
5765 u-boot mailing list. Bigger patches will be moderated. If they are
5766 reasonable and not too big, they will be acknowledged. But patches
5767 bigger than the size limit should be avoided.
projects / u-boot / blob