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_PCA953X * PCA953x I2C gpio commands
893 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
894 CONFIG_CMD_PCI * pciinfo
895 CONFIG_CMD_PCMCIA * PCMCIA support
896 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
898 CONFIG_CMD_PORTIO * Port I/O
899 CONFIG_CMD_READ * Read raw data from partition
900 CONFIG_CMD_REGINFO * Register dump
901 CONFIG_CMD_RUN run command in env variable
902 CONFIG_CMD_SANDBOX * sb command to access sandbox features
903 CONFIG_CMD_SAVES * save S record dump
904 CONFIG_CMD_SCSI * SCSI Support
905 CONFIG_CMD_SDRAM * print SDRAM configuration information
906 (requires CONFIG_CMD_I2C)
907 CONFIG_CMD_SETGETDCR Support for DCR Register access
909 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
910 CONFIG_CMD_SHA1SUM print sha1 memory digest
911 (requires CONFIG_CMD_MEMORY)
912 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
913 CONFIG_CMD_SOURCE "source" command Support
914 CONFIG_CMD_SPI * SPI serial bus support
915 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
916 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
917 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
918 CONFIG_CMD_TIMER * access to the system tick timer
919 CONFIG_CMD_USB * USB support
920 CONFIG_CMD_CDP * Cisco Discover Protocol support
921 CONFIG_CMD_MFSL * Microblaze FSL support
924 EXAMPLE: If you want all functions except of network
925 support you can write:
927 #include "config_cmd_all.h"
928 #undef CONFIG_CMD_NET
931 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
933 Note: Don't enable the "icache" and "dcache" commands
934 (configuration option CONFIG_CMD_CACHE) unless you know
935 what you (and your U-Boot users) are doing. Data
936 cache cannot be enabled on systems like the 8xx or
937 8260 (where accesses to the IMMR region must be
938 uncached), and it cannot be disabled on all other
939 systems where we (mis-) use the data cache to hold an
940 initial stack and some data.
943 XXX - this list needs to get updated!
945 - Regular expression support:
947 If this variable is defined, U-Boot is linked against
948 the SLRE (Super Light Regular Expression) library,
949 which adds regex support to some commands, as for
950 example "env grep" and "setexpr".
954 If this variable is defined, U-Boot will use a device tree
955 to configure its devices, instead of relying on statically
956 compiled #defines in the board file. This option is
957 experimental and only available on a few boards. The device
958 tree is available in the global data as gd->fdt_blob.
960 U-Boot needs to get its device tree from somewhere. This can
961 be done using one of the two options below:
964 If this variable is defined, U-Boot will embed a device tree
965 binary in its image. This device tree file should be in the
966 board directory and called <soc>-<board>.dts. The binary file
967 is then picked up in board_init_f() and made available through
968 the global data structure as gd->blob.
971 If this variable is defined, U-Boot will build a device tree
972 binary. It will be called u-boot.dtb. Architecture-specific
973 code will locate it at run-time. Generally this works by:
975 cat u-boot.bin u-boot.dtb >image.bin
977 and in fact, U-Boot does this for you, creating a file called
978 u-boot-dtb.bin which is useful in the common case. You can
979 still use the individual files if you need something more
984 If this variable is defined, it enables watchdog
985 support for the SoC. There must be support in the SoC
986 specific code for a watchdog. For the 8xx and 8260
987 CPUs, the SIU Watchdog feature is enabled in the SYPCR
988 register. When supported for a specific SoC is
989 available, then no further board specific code should
993 When using a watchdog circuitry external to the used
994 SoC, then define this variable and provide board
995 specific code for the "hw_watchdog_reset" function.
998 CONFIG_VERSION_VARIABLE
999 If this variable is defined, an environment variable
1000 named "ver" is created by U-Boot showing the U-Boot
1001 version as printed by the "version" command.
1002 Any change to this variable will be reverted at the
1007 When CONFIG_CMD_DATE is selected, the type of the RTC
1008 has to be selected, too. Define exactly one of the
1011 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1012 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1013 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1014 CONFIG_RTC_MC146818 - use MC146818 RTC
1015 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1016 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1017 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1018 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1019 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1020 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1021 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1022 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1025 Note that if the RTC uses I2C, then the I2C interface
1026 must also be configured. See I2C Support, below.
1029 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1030 CONFIG_PCA953X_INFO - enable pca953x info command
1032 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1033 chip-ngpio pairs that tell the PCA953X driver the number of
1034 pins supported by a particular chip.
1036 Note that if the GPIO device uses I2C, then the I2C interface
1037 must also be configured. See I2C Support, below.
1039 - Timestamp Support:
1041 When CONFIG_TIMESTAMP is selected, the timestamp
1042 (date and time) of an image is printed by image
1043 commands like bootm or iminfo. This option is
1044 automatically enabled when you select CONFIG_CMD_DATE .
1046 - Partition Labels (disklabels) Supported:
1047 Zero or more of the following:
1048 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1049 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1050 Intel architecture, USB sticks, etc.
1051 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1052 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1053 bootloader. Note 2TB partition limit; see
1055 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1057 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1058 CONFIG_CMD_SCSI) you must configure support for at
1059 least one non-MTD partition type as well.
1062 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1063 board configurations files but used nowhere!
1065 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1066 be performed by calling the function
1067 ide_set_reset(int reset)
1068 which has to be defined in a board specific file
1073 Set this to enable ATAPI support.
1078 Set this to enable support for disks larger than 137GB
1079 Also look at CONFIG_SYS_64BIT_LBA.
1080 Whithout these , LBA48 support uses 32bit variables and will 'only'
1081 support disks up to 2.1TB.
1083 CONFIG_SYS_64BIT_LBA:
1084 When enabled, makes the IDE subsystem use 64bit sector addresses.
1088 At the moment only there is only support for the
1089 SYM53C8XX SCSI controller; define
1090 CONFIG_SCSI_SYM53C8XX to enable it.
1092 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1093 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1094 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1095 maximum numbers of LUNs, SCSI ID's and target
1097 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1099 The environment variable 'scsidevs' is set to the number of
1100 SCSI devices found during the last scan.
1102 - NETWORK Support (PCI):
1104 Support for Intel 8254x/8257x gigabit chips.
1107 Utility code for direct access to the SPI bus on Intel 8257x.
1108 This does not do anything useful unless you set at least one
1109 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1111 CONFIG_E1000_SPI_GENERIC
1112 Allow generic access to the SPI bus on the Intel 8257x, for
1113 example with the "sspi" command.
1116 Management command for E1000 devices. When used on devices
1117 with SPI support you can reprogram the EEPROM from U-Boot.
1119 CONFIG_E1000_FALLBACK_MAC
1120 default MAC for empty EEPROM after production.
1123 Support for Intel 82557/82559/82559ER chips.
1124 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1125 write routine for first time initialisation.
1128 Support for Digital 2114x chips.
1129 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1130 modem chip initialisation (KS8761/QS6611).
1133 Support for National dp83815 chips.
1136 Support for National dp8382[01] gigabit chips.
1138 - NETWORK Support (other):
1140 CONFIG_DRIVER_AT91EMAC
1141 Support for AT91RM9200 EMAC.
1144 Define this to use reduced MII inteface
1146 CONFIG_DRIVER_AT91EMAC_QUIET
1147 If this defined, the driver is quiet.
1148 The driver doen't show link status messages.
1150 CONFIG_CALXEDA_XGMAC
1151 Support for the Calxeda XGMAC device
1154 Support for SMSC's LAN91C96 chips.
1156 CONFIG_LAN91C96_BASE
1157 Define this to hold the physical address
1158 of the LAN91C96's I/O space
1160 CONFIG_LAN91C96_USE_32_BIT
1161 Define this to enable 32 bit addressing
1164 Support for SMSC's LAN91C111 chip
1166 CONFIG_SMC91111_BASE
1167 Define this to hold the physical address
1168 of the device (I/O space)
1170 CONFIG_SMC_USE_32_BIT
1171 Define this if data bus is 32 bits
1173 CONFIG_SMC_USE_IOFUNCS
1174 Define this to use i/o functions instead of macros
1175 (some hardware wont work with macros)
1177 CONFIG_DRIVER_TI_EMAC
1178 Support for davinci emac
1180 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1181 Define this if you have more then 3 PHYs.
1184 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1186 CONFIG_FTGMAC100_EGIGA
1187 Define this to use GE link update with gigabit PHY.
1188 Define this if FTGMAC100 is connected to gigabit PHY.
1189 If your system has 10/100 PHY only, it might not occur
1190 wrong behavior. Because PHY usually return timeout or
1191 useless data when polling gigabit status and gigabit
1192 control registers. This behavior won't affect the
1193 correctnessof 10/100 link speed update.
1196 Support for SMSC's LAN911x and LAN921x chips
1199 Define this to hold the physical address
1200 of the device (I/O space)
1202 CONFIG_SMC911X_32_BIT
1203 Define this if data bus is 32 bits
1205 CONFIG_SMC911X_16_BIT
1206 Define this if data bus is 16 bits. If your processor
1207 automatically converts one 32 bit word to two 16 bit
1208 words you may also try CONFIG_SMC911X_32_BIT.
1211 Support for Renesas on-chip Ethernet controller
1213 CONFIG_SH_ETHER_USE_PORT
1214 Define the number of ports to be used
1216 CONFIG_SH_ETHER_PHY_ADDR
1217 Define the ETH PHY's address
1219 CONFIG_SH_ETHER_CACHE_WRITEBACK
1220 If this option is set, the driver enables cache flush.
1224 Support TPM devices.
1227 Support for i2c bus TPM devices. Only one device
1228 per system is supported at this time.
1230 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1231 Define the the i2c bus number for the TPM device
1233 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1234 Define the TPM's address on the i2c bus
1236 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1237 Define the burst count bytes upper limit
1240 Support for generic parallel port TPM devices. Only one device
1241 per system is supported at this time.
1243 CONFIG_TPM_TIS_BASE_ADDRESS
1244 Base address where the generic TPM device is mapped
1245 to. Contemporary x86 systems usually map it at
1249 At the moment only the UHCI host controller is
1250 supported (PIP405, MIP405, MPC5200); define
1251 CONFIG_USB_UHCI to enable it.
1252 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1253 and define CONFIG_USB_STORAGE to enable the USB
1256 Supported are USB Keyboards and USB Floppy drives
1258 MPC5200 USB requires additional defines:
1260 for 528 MHz Clock: 0x0001bbbb
1264 for differential drivers: 0x00001000
1265 for single ended drivers: 0x00005000
1266 for differential drivers on PSC3: 0x00000100
1267 for single ended drivers on PSC3: 0x00004100
1268 CONFIG_SYS_USB_EVENT_POLL
1269 May be defined to allow interrupt polling
1270 instead of using asynchronous interrupts
1272 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1273 txfilltuning field in the EHCI controller on reset.
1275 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1276 interval for usb hub power-on delay.(minimum 100msec)
1279 Define the below if you wish to use the USB console.
1280 Once firmware is rebuilt from a serial console issue the
1281 command "setenv stdin usbtty; setenv stdout usbtty" and
1282 attach your USB cable. The Unix command "dmesg" should print
1283 it has found a new device. The environment variable usbtty
1284 can be set to gserial or cdc_acm to enable your device to
1285 appear to a USB host as a Linux gserial device or a
1286 Common Device Class Abstract Control Model serial device.
1287 If you select usbtty = gserial you should be able to enumerate
1289 # modprobe usbserial vendor=0xVendorID product=0xProductID
1290 else if using cdc_acm, simply setting the environment
1291 variable usbtty to be cdc_acm should suffice. The following
1292 might be defined in YourBoardName.h
1295 Define this to build a UDC device
1298 Define this to have a tty type of device available to
1299 talk to the UDC device
1302 Define this to enable the high speed support for usb
1303 device and usbtty. If this feature is enabled, a routine
1304 int is_usbd_high_speed(void)
1305 also needs to be defined by the driver to dynamically poll
1306 whether the enumeration has succeded at high speed or full
1309 CONFIG_SYS_CONSOLE_IS_IN_ENV
1310 Define this if you want stdin, stdout &/or stderr to
1314 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1315 Derive USB clock from external clock "blah"
1316 - CONFIG_SYS_USB_EXTC_CLK 0x02
1318 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1319 Derive USB clock from brgclk
1320 - CONFIG_SYS_USB_BRG_CLK 0x04
1322 If you have a USB-IF assigned VendorID then you may wish to
1323 define your own vendor specific values either in BoardName.h
1324 or directly in usbd_vendor_info.h. If you don't define
1325 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1326 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1327 should pretend to be a Linux device to it's target host.
1329 CONFIG_USBD_MANUFACTURER
1330 Define this string as the name of your company for
1331 - CONFIG_USBD_MANUFACTURER "my company"
1333 CONFIG_USBD_PRODUCT_NAME
1334 Define this string as the name of your product
1335 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1337 CONFIG_USBD_VENDORID
1338 Define this as your assigned Vendor ID from the USB
1339 Implementors Forum. This *must* be a genuine Vendor ID
1340 to avoid polluting the USB namespace.
1341 - CONFIG_USBD_VENDORID 0xFFFF
1343 CONFIG_USBD_PRODUCTID
1344 Define this as the unique Product ID
1346 - CONFIG_USBD_PRODUCTID 0xFFFF
1348 - ULPI Layer Support:
1349 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1350 the generic ULPI layer. The generic layer accesses the ULPI PHY
1351 via the platform viewport, so you need both the genric layer and
1352 the viewport enabled. Currently only Chipidea/ARC based
1353 viewport is supported.
1354 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1355 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1356 If your ULPI phy needs a different reference clock than the
1357 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1358 the appropriate value in Hz.
1361 The MMC controller on the Intel PXA is supported. To
1362 enable this define CONFIG_MMC. The MMC can be
1363 accessed from the boot prompt by mapping the device
1364 to physical memory similar to flash. Command line is
1365 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1366 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1369 Support for Renesas on-chip MMCIF controller
1371 CONFIG_SH_MMCIF_ADDR
1372 Define the base address of MMCIF registers
1375 Define the clock frequency for MMCIF
1377 - USB Device Firmware Update (DFU) class support:
1379 This enables the USB portion of the DFU USB class
1382 This enables the command "dfu" which is used to have
1383 U-Boot create a DFU class device via USB. This command
1384 requires that the "dfu_alt_info" environment variable be
1385 set and define the alt settings to expose to the host.
1388 This enables support for exposing (e)MMC devices via DFU.
1391 This enables support for exposing NAND devices via DFU.
1393 CONFIG_SYS_DFU_MAX_FILE_SIZE
1394 When updating files rather than the raw storage device,
1395 we use a static buffer to copy the file into and then write
1396 the buffer once we've been given the whole file. Define
1397 this to the maximum filesize (in bytes) for the buffer.
1398 Default is 4 MiB if undefined.
1400 - Journaling Flash filesystem support:
1401 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1402 CONFIG_JFFS2_NAND_DEV
1403 Define these for a default partition on a NAND device
1405 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1406 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1407 Define these for a default partition on a NOR device
1409 CONFIG_SYS_JFFS_CUSTOM_PART
1410 Define this to create an own partition. You have to provide a
1411 function struct part_info* jffs2_part_info(int part_num)
1413 If you define only one JFFS2 partition you may also want to
1414 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1415 to disable the command chpart. This is the default when you
1416 have not defined a custom partition
1418 - FAT(File Allocation Table) filesystem write function support:
1421 Define this to enable support for saving memory data as a
1422 file in FAT formatted partition.
1424 This will also enable the command "fatwrite" enabling the
1425 user to write files to FAT.
1427 CBFS (Coreboot Filesystem) support
1430 Define this to enable support for reading from a Coreboot
1431 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1437 Define this to enable standard (PC-Style) keyboard
1441 Standard PC keyboard driver with US (is default) and
1442 GERMAN key layout (switch via environment 'keymap=de') support.
1443 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1444 for cfb_console. Supports cursor blinking.
1447 Enables a Chrome OS keyboard using the CROS_EC interface.
1448 This uses CROS_EC to communicate with a second microcontroller
1449 which provides key scans on request.
1454 Define this to enable video support (for output to
1457 CONFIG_VIDEO_CT69000
1459 Enable Chips & Technologies 69000 Video chip
1461 CONFIG_VIDEO_SMI_LYNXEM
1462 Enable Silicon Motion SMI 712/710/810 Video chip. The
1463 video output is selected via environment 'videoout'
1464 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1467 For the CT69000 and SMI_LYNXEM drivers, videomode is
1468 selected via environment 'videomode'. Two different ways
1470 - "videomode=num" 'num' is a standard LiLo mode numbers.
1471 Following standard modes are supported (* is default):
1473 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1474 -------------+---------------------------------------------
1475 8 bits | 0x301* 0x303 0x305 0x161 0x307
1476 15 bits | 0x310 0x313 0x316 0x162 0x319
1477 16 bits | 0x311 0x314 0x317 0x163 0x31A
1478 24 bits | 0x312 0x315 0x318 ? 0x31B
1479 -------------+---------------------------------------------
1480 (i.e. setenv videomode 317; saveenv; reset;)
1482 - "videomode=bootargs" all the video parameters are parsed
1483 from the bootargs. (See drivers/video/videomodes.c)
1486 CONFIG_VIDEO_SED13806
1487 Enable Epson SED13806 driver. This driver supports 8bpp
1488 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1489 or CONFIG_VIDEO_SED13806_16BPP
1492 Enable the Freescale DIU video driver. Reference boards for
1493 SOCs that have a DIU should define this macro to enable DIU
1494 support, and should also define these other macros:
1500 CONFIG_VIDEO_SW_CURSOR
1501 CONFIG_VGA_AS_SINGLE_DEVICE
1503 CONFIG_VIDEO_BMP_LOGO
1505 The DIU driver will look for the 'video-mode' environment
1506 variable, and if defined, enable the DIU as a console during
1507 boot. See the documentation file README.video for a
1508 description of this variable.
1512 Enable the VGA video / BIOS for x86. The alternative if you
1513 are using coreboot is to use the coreboot frame buffer
1520 Define this to enable a custom keyboard support.
1521 This simply calls drv_keyboard_init() which must be
1522 defined in your board-specific files.
1523 The only board using this so far is RBC823.
1525 - LCD Support: CONFIG_LCD
1527 Define this to enable LCD support (for output to LCD
1528 display); also select one of the supported displays
1529 by defining one of these:
1533 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1535 CONFIG_NEC_NL6448AC33:
1537 NEC NL6448AC33-18. Active, color, single scan.
1539 CONFIG_NEC_NL6448BC20
1541 NEC NL6448BC20-08. 6.5", 640x480.
1542 Active, color, single scan.
1544 CONFIG_NEC_NL6448BC33_54
1546 NEC NL6448BC33-54. 10.4", 640x480.
1547 Active, color, single scan.
1551 Sharp 320x240. Active, color, single scan.
1552 It isn't 16x9, and I am not sure what it is.
1554 CONFIG_SHARP_LQ64D341
1556 Sharp LQ64D341 display, 640x480.
1557 Active, color, single scan.
1561 HLD1045 display, 640x480.
1562 Active, color, single scan.
1566 Optrex CBL50840-2 NF-FW 99 22 M5
1568 Hitachi LMG6912RPFC-00T
1572 320x240. Black & white.
1574 Normally display is black on white background; define
1575 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1577 CONFIG_LCD_ALIGNMENT
1579 Normally the LCD is page-aligned (tyically 4KB). If this is
1580 defined then the LCD will be aligned to this value instead.
1581 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1582 here, since it is cheaper to change data cache settings on
1583 a per-section basis.
1585 CONFIG_CONSOLE_SCROLL_LINES
1587 When the console need to be scrolled, this is the number of
1588 lines to scroll by. It defaults to 1. Increasing this makes
1589 the console jump but can help speed up operation when scrolling
1594 Support drawing of RLE8-compressed bitmaps on the LCD.
1598 Enables an 'i2c edid' command which can read EDID
1599 information over I2C from an attached LCD display.
1601 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1603 If this option is set, the environment is checked for
1604 a variable "splashimage". If found, the usual display
1605 of logo, copyright and system information on the LCD
1606 is suppressed and the BMP image at the address
1607 specified in "splashimage" is loaded instead. The
1608 console is redirected to the "nulldev", too. This
1609 allows for a "silent" boot where a splash screen is
1610 loaded very quickly after power-on.
1612 CONFIG_SPLASHIMAGE_GUARD
1614 If this option is set, then U-Boot will prevent the environment
1615 variable "splashimage" from being set to a problematic address
1616 (see README.displaying-bmps and README.arm-unaligned-accesses).
1617 This option is useful for targets where, due to alignment
1618 restrictions, an improperly aligned BMP image will cause a data
1619 abort. If you think you will not have problems with unaligned
1620 accesses (for example because your toolchain prevents them)
1621 there is no need to set this option.
1623 CONFIG_SPLASH_SCREEN_ALIGN
1625 If this option is set the splash image can be freely positioned
1626 on the screen. Environment variable "splashpos" specifies the
1627 position as "x,y". If a positive number is given it is used as
1628 number of pixel from left/top. If a negative number is given it
1629 is used as number of pixel from right/bottom. You can also
1630 specify 'm' for centering the image.
1633 setenv splashpos m,m
1634 => image at center of screen
1636 setenv splashpos 30,20
1637 => image at x = 30 and y = 20
1639 setenv splashpos -10,m
1640 => vertically centered image
1641 at x = dspWidth - bmpWidth - 9
1643 CONFIG_SPLASH_SCREEN_PREPARE
1645 If this option is set then the board_splash_screen_prepare()
1646 function, which must be defined in your code, is called as part
1647 of the splash screen display sequence. It gives the board an
1648 opportunity to prepare the splash image data before it is
1649 processed and sent to the frame buffer by U-Boot.
1651 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1653 If this option is set, additionally to standard BMP
1654 images, gzipped BMP images can be displayed via the
1655 splashscreen support or the bmp command.
1657 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1659 If this option is set, 8-bit RLE compressed BMP images
1660 can be displayed via the splashscreen support or the
1663 - Do compresssing for memory range:
1666 If this option is set, it would use zlib deflate method
1667 to compress the specified memory at its best effort.
1669 - Compression support:
1672 If this option is set, support for bzip2 compressed
1673 images is included. If not, only uncompressed and gzip
1674 compressed images are supported.
1676 NOTE: the bzip2 algorithm requires a lot of RAM, so
1677 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1682 If this option is set, support for lzma compressed
1685 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1686 requires an amount of dynamic memory that is given by the
1689 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1691 Where lc and lp stand for, respectively, Literal context bits
1692 and Literal pos bits.
1694 This value is upper-bounded by 14MB in the worst case. Anyway,
1695 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1696 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1697 a very small buffer.
1699 Use the lzmainfo tool to determinate the lc and lp values and
1700 then calculate the amount of needed dynamic memory (ensuring
1701 the appropriate CONFIG_SYS_MALLOC_LEN value).
1706 The address of PHY on MII bus.
1708 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1710 The clock frequency of the MII bus
1714 If this option is set, support for speed/duplex
1715 detection of gigabit PHY is included.
1717 CONFIG_PHY_RESET_DELAY
1719 Some PHY like Intel LXT971A need extra delay after
1720 reset before any MII register access is possible.
1721 For such PHY, set this option to the usec delay
1722 required. (minimum 300usec for LXT971A)
1724 CONFIG_PHY_CMD_DELAY (ppc4xx)
1726 Some PHY like Intel LXT971A need extra delay after
1727 command issued before MII status register can be read
1737 Define a default value for Ethernet address to use
1738 for the respective Ethernet interface, in case this
1739 is not determined automatically.
1744 Define a default value for the IP address to use for
1745 the default Ethernet interface, in case this is not
1746 determined through e.g. bootp.
1747 (Environment variable "ipaddr")
1749 - Server IP address:
1752 Defines a default value for the IP address of a TFTP
1753 server to contact when using the "tftboot" command.
1754 (Environment variable "serverip")
1756 CONFIG_KEEP_SERVERADDR
1758 Keeps the server's MAC address, in the env 'serveraddr'
1759 for passing to bootargs (like Linux's netconsole option)
1761 - Gateway IP address:
1764 Defines a default value for the IP address of the
1765 default router where packets to other networks are
1767 (Environment variable "gatewayip")
1772 Defines a default value for the subnet mask (or
1773 routing prefix) which is used to determine if an IP
1774 address belongs to the local subnet or needs to be
1775 forwarded through a router.
1776 (Environment variable "netmask")
1778 - Multicast TFTP Mode:
1781 Defines whether you want to support multicast TFTP as per
1782 rfc-2090; for example to work with atftp. Lets lots of targets
1783 tftp down the same boot image concurrently. Note: the Ethernet
1784 driver in use must provide a function: mcast() to join/leave a
1787 - BOOTP Recovery Mode:
1788 CONFIG_BOOTP_RANDOM_DELAY
1790 If you have many targets in a network that try to
1791 boot using BOOTP, you may want to avoid that all
1792 systems send out BOOTP requests at precisely the same
1793 moment (which would happen for instance at recovery
1794 from a power failure, when all systems will try to
1795 boot, thus flooding the BOOTP server. Defining
1796 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1797 inserted before sending out BOOTP requests. The
1798 following delays are inserted then:
1800 1st BOOTP request: delay 0 ... 1 sec
1801 2nd BOOTP request: delay 0 ... 2 sec
1802 3rd BOOTP request: delay 0 ... 4 sec
1804 BOOTP requests: delay 0 ... 8 sec
1806 - DHCP Advanced Options:
1807 You can fine tune the DHCP functionality by defining
1808 CONFIG_BOOTP_* symbols:
1810 CONFIG_BOOTP_SUBNETMASK
1811 CONFIG_BOOTP_GATEWAY
1812 CONFIG_BOOTP_HOSTNAME
1813 CONFIG_BOOTP_NISDOMAIN
1814 CONFIG_BOOTP_BOOTPATH
1815 CONFIG_BOOTP_BOOTFILESIZE
1818 CONFIG_BOOTP_SEND_HOSTNAME
1819 CONFIG_BOOTP_NTPSERVER
1820 CONFIG_BOOTP_TIMEOFFSET
1821 CONFIG_BOOTP_VENDOREX
1822 CONFIG_BOOTP_MAY_FAIL
1824 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1825 environment variable, not the BOOTP server.
1827 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1828 after the configured retry count, the call will fail
1829 instead of starting over. This can be used to fail over
1830 to Link-local IP address configuration if the DHCP server
1833 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1834 serverip from a DHCP server, it is possible that more
1835 than one DNS serverip is offered to the client.
1836 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1837 serverip will be stored in the additional environment
1838 variable "dnsip2". The first DNS serverip is always
1839 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1842 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1843 to do a dynamic update of a DNS server. To do this, they
1844 need the hostname of the DHCP requester.
1845 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1846 of the "hostname" environment variable is passed as
1847 option 12 to the DHCP server.
1849 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1851 A 32bit value in microseconds for a delay between
1852 receiving a "DHCP Offer" and sending the "DHCP Request".
1853 This fixes a problem with certain DHCP servers that don't
1854 respond 100% of the time to a "DHCP request". E.g. On an
1855 AT91RM9200 processor running at 180MHz, this delay needed
1856 to be *at least* 15,000 usec before a Windows Server 2003
1857 DHCP server would reply 100% of the time. I recommend at
1858 least 50,000 usec to be safe. The alternative is to hope
1859 that one of the retries will be successful but note that
1860 the DHCP timeout and retry process takes a longer than
1863 - Link-local IP address negotiation:
1864 Negotiate with other link-local clients on the local network
1865 for an address that doesn't require explicit configuration.
1866 This is especially useful if a DHCP server cannot be guaranteed
1867 to exist in all environments that the device must operate.
1869 See doc/README.link-local for more information.
1872 CONFIG_CDP_DEVICE_ID
1874 The device id used in CDP trigger frames.
1876 CONFIG_CDP_DEVICE_ID_PREFIX
1878 A two character string which is prefixed to the MAC address
1883 A printf format string which contains the ascii name of
1884 the port. Normally is set to "eth%d" which sets
1885 eth0 for the first Ethernet, eth1 for the second etc.
1887 CONFIG_CDP_CAPABILITIES
1889 A 32bit integer which indicates the device capabilities;
1890 0x00000010 for a normal host which does not forwards.
1894 An ascii string containing the version of the software.
1898 An ascii string containing the name of the platform.
1902 A 32bit integer sent on the trigger.
1904 CONFIG_CDP_POWER_CONSUMPTION
1906 A 16bit integer containing the power consumption of the
1907 device in .1 of milliwatts.
1909 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1911 A byte containing the id of the VLAN.
1913 - Status LED: CONFIG_STATUS_LED
1915 Several configurations allow to display the current
1916 status using a LED. For instance, the LED will blink
1917 fast while running U-Boot code, stop blinking as
1918 soon as a reply to a BOOTP request was received, and
1919 start blinking slow once the Linux kernel is running
1920 (supported by a status LED driver in the Linux
1921 kernel). Defining CONFIG_STATUS_LED enables this
1924 - CAN Support: CONFIG_CAN_DRIVER
1926 Defining CONFIG_CAN_DRIVER enables CAN driver support
1927 on those systems that support this (optional)
1928 feature, like the TQM8xxL modules.
1930 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1932 These enable I2C serial bus commands. Defining either of
1933 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1934 include the appropriate I2C driver for the selected CPU.
1936 This will allow you to use i2c commands at the u-boot
1937 command line (as long as you set CONFIG_CMD_I2C in
1938 CONFIG_COMMANDS) and communicate with i2c based realtime
1939 clock chips. See common/cmd_i2c.c for a description of the
1940 command line interface.
1942 CONFIG_HARD_I2C selects a hardware I2C controller.
1944 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1945 bit-banging) driver instead of CPM or similar hardware
1948 There are several other quantities that must also be
1949 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1951 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1952 to be the frequency (in Hz) at which you wish your i2c bus
1953 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1954 the CPU's i2c node address).
1956 Now, the u-boot i2c code for the mpc8xx
1957 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1958 and so its address should therefore be cleared to 0 (See,
1959 eg, MPC823e User's Manual p.16-473). So, set
1960 CONFIG_SYS_I2C_SLAVE to 0.
1962 CONFIG_SYS_I2C_INIT_MPC5XXX
1964 When a board is reset during an i2c bus transfer
1965 chips might think that the current transfer is still
1966 in progress. Reset the slave devices by sending start
1967 commands until the slave device responds.
1969 That's all that's required for CONFIG_HARD_I2C.
1971 If you use the software i2c interface (CONFIG_SOFT_I2C)
1972 then the following macros need to be defined (examples are
1973 from include/configs/lwmon.h):
1977 (Optional). Any commands necessary to enable the I2C
1978 controller or configure ports.
1980 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1984 (Only for MPC8260 CPU). The I/O port to use (the code
1985 assumes both bits are on the same port). Valid values
1986 are 0..3 for ports A..D.
1990 The code necessary to make the I2C data line active
1991 (driven). If the data line is open collector, this
1994 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1998 The code necessary to make the I2C data line tri-stated
1999 (inactive). If the data line is open collector, this
2002 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2006 Code that returns true if the I2C data line is high,
2009 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2013 If <bit> is true, sets the I2C data line high. If it
2014 is false, it clears it (low).
2016 eg: #define I2C_SDA(bit) \
2017 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2018 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2022 If <bit> is true, sets the I2C clock line high. If it
2023 is false, it clears it (low).
2025 eg: #define I2C_SCL(bit) \
2026 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2027 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2031 This delay is invoked four times per clock cycle so this
2032 controls the rate of data transfer. The data rate thus
2033 is 1 / (I2C_DELAY * 4). Often defined to be something
2036 #define I2C_DELAY udelay(2)
2038 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2040 If your arch supports the generic GPIO framework (asm/gpio.h),
2041 then you may alternatively define the two GPIOs that are to be
2042 used as SCL / SDA. Any of the previous I2C_xxx macros will
2043 have GPIO-based defaults assigned to them as appropriate.
2045 You should define these to the GPIO value as given directly to
2046 the generic GPIO functions.
2048 CONFIG_SYS_I2C_INIT_BOARD
2050 When a board is reset during an i2c bus transfer
2051 chips might think that the current transfer is still
2052 in progress. On some boards it is possible to access
2053 the i2c SCLK line directly, either by using the
2054 processor pin as a GPIO or by having a second pin
2055 connected to the bus. If this option is defined a
2056 custom i2c_init_board() routine in boards/xxx/board.c
2057 is run early in the boot sequence.
2059 CONFIG_SYS_I2C_BOARD_LATE_INIT
2061 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2062 defined a custom i2c_board_late_init() routine in
2063 boards/xxx/board.c is run AFTER the operations in i2c_init()
2064 is completed. This callpoint can be used to unreset i2c bus
2065 using CPU i2c controller register accesses for CPUs whose i2c
2066 controller provide such a method. It is called at the end of
2067 i2c_init() to allow i2c_init operations to setup the i2c bus
2068 controller on the CPU (e.g. setting bus speed & slave address).
2070 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2072 This option enables configuration of bi_iic_fast[] flags
2073 in u-boot bd_info structure based on u-boot environment
2074 variable "i2cfast". (see also i2cfast)
2076 CONFIG_I2C_MULTI_BUS
2078 This option allows the use of multiple I2C buses, each of which
2079 must have a controller. At any point in time, only one bus is
2080 active. To switch to a different bus, use the 'i2c dev' command.
2081 Note that bus numbering is zero-based.
2083 CONFIG_SYS_I2C_NOPROBES
2085 This option specifies a list of I2C devices that will be skipped
2086 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2087 is set, specify a list of bus-device pairs. Otherwise, specify
2088 a 1D array of device addresses
2091 #undef CONFIG_I2C_MULTI_BUS
2092 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2094 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2096 #define CONFIG_I2C_MULTI_BUS
2097 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2099 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2101 CONFIG_SYS_SPD_BUS_NUM
2103 If defined, then this indicates the I2C bus number for DDR SPD.
2104 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2106 CONFIG_SYS_RTC_BUS_NUM
2108 If defined, then this indicates the I2C bus number for the RTC.
2109 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2111 CONFIG_SYS_DTT_BUS_NUM
2113 If defined, then this indicates the I2C bus number for the DTT.
2114 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2116 CONFIG_SYS_I2C_DTT_ADDR:
2118 If defined, specifies the I2C address of the DTT device.
2119 If not defined, then U-Boot uses predefined value for
2120 specified DTT device.
2124 Define this option if you want to use Freescale's I2C driver in
2125 drivers/i2c/fsl_i2c.c.
2129 Define this option if you have I2C devices reached over 1 .. n
2130 I2C Muxes like the pca9544a. This option addes a new I2C
2131 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2132 new I2C Bus to the existing I2C Busses. If you select the
2133 new Bus with "i2c dev", u-bbot sends first the commandos for
2134 the muxes to activate this new "bus".
2136 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2140 Adding a new I2C Bus reached over 2 pca9544a muxes
2141 The First mux with address 70 and channel 6
2142 The Second mux with address 71 and channel 4
2144 => i2c bus pca9544a:70:6:pca9544a:71:4
2146 Use the "i2c bus" command without parameter, to get a list
2147 of I2C Busses with muxes:
2150 Busses reached over muxes:
2152 reached over Mux(es):
2155 reached over Mux(es):
2160 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2161 u-boot first sends the command to the mux@70 to enable
2162 channel 6, and then the command to the mux@71 to enable
2165 After that, you can use the "normal" i2c commands as
2166 usual to communicate with your I2C devices behind
2169 This option is actually implemented for the bitbanging
2170 algorithm in common/soft_i2c.c and for the Hardware I2C
2171 Bus on the MPC8260. But it should be not so difficult
2172 to add this option to other architectures.
2174 CONFIG_SOFT_I2C_READ_REPEATED_START
2176 defining this will force the i2c_read() function in
2177 the soft_i2c driver to perform an I2C repeated start
2178 between writing the address pointer and reading the
2179 data. If this define is omitted the default behaviour
2180 of doing a stop-start sequence will be used. Most I2C
2181 devices can use either method, but some require one or
2184 - SPI Support: CONFIG_SPI
2186 Enables SPI driver (so far only tested with
2187 SPI EEPROM, also an instance works with Crystal A/D and
2188 D/As on the SACSng board)
2192 Enables the driver for SPI controller on SuperH. Currently
2193 only SH7757 is supported.
2197 Enables extended (16-bit) SPI EEPROM addressing.
2198 (symmetrical to CONFIG_I2C_X)
2202 Enables a software (bit-bang) SPI driver rather than
2203 using hardware support. This is a general purpose
2204 driver that only requires three general I/O port pins
2205 (two outputs, one input) to function. If this is
2206 defined, the board configuration must define several
2207 SPI configuration items (port pins to use, etc). For
2208 an example, see include/configs/sacsng.h.
2212 Enables a hardware SPI driver for general-purpose reads
2213 and writes. As with CONFIG_SOFT_SPI, the board configuration
2214 must define a list of chip-select function pointers.
2215 Currently supported on some MPC8xxx processors. For an
2216 example, see include/configs/mpc8349emds.h.
2220 Enables the driver for the SPI controllers on i.MX and MXC
2221 SoCs. Currently i.MX31/35/51 are supported.
2223 - FPGA Support: CONFIG_FPGA
2225 Enables FPGA subsystem.
2227 CONFIG_FPGA_<vendor>
2229 Enables support for specific chip vendors.
2232 CONFIG_FPGA_<family>
2234 Enables support for FPGA family.
2235 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2239 Specify the number of FPGA devices to support.
2241 CONFIG_SYS_FPGA_PROG_FEEDBACK
2243 Enable printing of hash marks during FPGA configuration.
2245 CONFIG_SYS_FPGA_CHECK_BUSY
2247 Enable checks on FPGA configuration interface busy
2248 status by the configuration function. This option
2249 will require a board or device specific function to
2254 If defined, a function that provides delays in the FPGA
2255 configuration driver.
2257 CONFIG_SYS_FPGA_CHECK_CTRLC
2258 Allow Control-C to interrupt FPGA configuration
2260 CONFIG_SYS_FPGA_CHECK_ERROR
2262 Check for configuration errors during FPGA bitfile
2263 loading. For example, abort during Virtex II
2264 configuration if the INIT_B line goes low (which
2265 indicated a CRC error).
2267 CONFIG_SYS_FPGA_WAIT_INIT
2269 Maximum time to wait for the INIT_B line to deassert
2270 after PROB_B has been deasserted during a Virtex II
2271 FPGA configuration sequence. The default time is 500
2274 CONFIG_SYS_FPGA_WAIT_BUSY
2276 Maximum time to wait for BUSY to deassert during
2277 Virtex II FPGA configuration. The default is 5 ms.
2279 CONFIG_SYS_FPGA_WAIT_CONFIG
2281 Time to wait after FPGA configuration. The default is
2284 - Configuration Management:
2287 If defined, this string will be added to the U-Boot
2288 version information (U_BOOT_VERSION)
2290 - Vendor Parameter Protection:
2292 U-Boot considers the values of the environment
2293 variables "serial#" (Board Serial Number) and
2294 "ethaddr" (Ethernet Address) to be parameters that
2295 are set once by the board vendor / manufacturer, and
2296 protects these variables from casual modification by
2297 the user. Once set, these variables are read-only,
2298 and write or delete attempts are rejected. You can
2299 change this behaviour:
2301 If CONFIG_ENV_OVERWRITE is #defined in your config
2302 file, the write protection for vendor parameters is
2303 completely disabled. Anybody can change or delete
2306 Alternatively, if you #define _both_ CONFIG_ETHADDR
2307 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2308 Ethernet address is installed in the environment,
2309 which can be changed exactly ONCE by the user. [The
2310 serial# is unaffected by this, i. e. it remains
2313 The same can be accomplished in a more flexible way
2314 for any variable by configuring the type of access
2315 to allow for those variables in the ".flags" variable
2316 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2321 Define this variable to enable the reservation of
2322 "protected RAM", i. e. RAM which is not overwritten
2323 by U-Boot. Define CONFIG_PRAM to hold the number of
2324 kB you want to reserve for pRAM. You can overwrite
2325 this default value by defining an environment
2326 variable "pram" to the number of kB you want to
2327 reserve. Note that the board info structure will
2328 still show the full amount of RAM. If pRAM is
2329 reserved, a new environment variable "mem" will
2330 automatically be defined to hold the amount of
2331 remaining RAM in a form that can be passed as boot
2332 argument to Linux, for instance like that:
2334 setenv bootargs ... mem=\${mem}
2337 This way you can tell Linux not to use this memory,
2338 either, which results in a memory region that will
2339 not be affected by reboots.
2341 *WARNING* If your board configuration uses automatic
2342 detection of the RAM size, you must make sure that
2343 this memory test is non-destructive. So far, the
2344 following board configurations are known to be
2347 IVMS8, IVML24, SPD8xx, TQM8xxL,
2348 HERMES, IP860, RPXlite, LWMON,
2351 - Access to physical memory region (> 4GB)
2352 Some basic support is provided for operations on memory not
2353 normally accessible to U-Boot - e.g. some architectures
2354 support access to more than 4GB of memory on 32-bit
2355 machines using physical address extension or similar.
2356 Define CONFIG_PHYSMEM to access this basic support, which
2357 currently only supports clearing the memory.
2362 Define this variable to stop the system in case of a
2363 fatal error, so that you have to reset it manually.
2364 This is probably NOT a good idea for an embedded
2365 system where you want the system to reboot
2366 automatically as fast as possible, but it may be
2367 useful during development since you can try to debug
2368 the conditions that lead to the situation.
2370 CONFIG_NET_RETRY_COUNT
2372 This variable defines the number of retries for
2373 network operations like ARP, RARP, TFTP, or BOOTP
2374 before giving up the operation. If not defined, a
2375 default value of 5 is used.
2379 Timeout waiting for an ARP reply in milliseconds.
2383 Timeout in milliseconds used in NFS protocol.
2384 If you encounter "ERROR: Cannot umount" in nfs command,
2385 try longer timeout such as
2386 #define CONFIG_NFS_TIMEOUT 10000UL
2388 - Command Interpreter:
2389 CONFIG_AUTO_COMPLETE
2391 Enable auto completion of commands using TAB.
2393 Note that this feature has NOT been implemented yet
2394 for the "hush" shell.
2397 CONFIG_SYS_HUSH_PARSER
2399 Define this variable to enable the "hush" shell (from
2400 Busybox) as command line interpreter, thus enabling
2401 powerful command line syntax like
2402 if...then...else...fi conditionals or `&&' and '||'
2403 constructs ("shell scripts").
2405 If undefined, you get the old, much simpler behaviour
2406 with a somewhat smaller memory footprint.
2409 CONFIG_SYS_PROMPT_HUSH_PS2
2411 This defines the secondary prompt string, which is
2412 printed when the command interpreter needs more input
2413 to complete a command. Usually "> ".
2417 In the current implementation, the local variables
2418 space and global environment variables space are
2419 separated. Local variables are those you define by
2420 simply typing `name=value'. To access a local
2421 variable later on, you have write `$name' or
2422 `${name}'; to execute the contents of a variable
2423 directly type `$name' at the command prompt.
2425 Global environment variables are those you use
2426 setenv/printenv to work with. To run a command stored
2427 in such a variable, you need to use the run command,
2428 and you must not use the '$' sign to access them.
2430 To store commands and special characters in a
2431 variable, please use double quotation marks
2432 surrounding the whole text of the variable, instead
2433 of the backslashes before semicolons and special
2436 - Commandline Editing and History:
2437 CONFIG_CMDLINE_EDITING
2439 Enable editing and History functions for interactive
2440 commandline input operations
2442 - Default Environment:
2443 CONFIG_EXTRA_ENV_SETTINGS
2445 Define this to contain any number of null terminated
2446 strings (variable = value pairs) that will be part of
2447 the default environment compiled into the boot image.
2449 For example, place something like this in your
2450 board's config file:
2452 #define CONFIG_EXTRA_ENV_SETTINGS \
2456 Warning: This method is based on knowledge about the
2457 internal format how the environment is stored by the
2458 U-Boot code. This is NOT an official, exported
2459 interface! Although it is unlikely that this format
2460 will change soon, there is no guarantee either.
2461 You better know what you are doing here.
2463 Note: overly (ab)use of the default environment is
2464 discouraged. Make sure to check other ways to preset
2465 the environment like the "source" command or the
2468 CONFIG_ENV_VARS_UBOOT_CONFIG
2470 Define this in order to add variables describing the
2471 U-Boot build configuration to the default environment.
2472 These will be named arch, cpu, board, vendor, and soc.
2474 Enabling this option will cause the following to be defined:
2482 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2484 Define this in order to add variables describing certain
2485 run-time determined information about the hardware to the
2486 environment. These will be named board_name, board_rev.
2488 CONFIG_DELAY_ENVIRONMENT
2490 Normally the environment is loaded when the board is
2491 intialised so that it is available to U-Boot. This inhibits
2492 that so that the environment is not available until
2493 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2494 this is instead controlled by the value of
2495 /config/load-environment.
2497 - DataFlash Support:
2498 CONFIG_HAS_DATAFLASH
2500 Defining this option enables DataFlash features and
2501 allows to read/write in Dataflash via the standard
2504 - Serial Flash support
2507 Defining this option enables SPI flash commands
2508 'sf probe/read/write/erase/update'.
2510 Usage requires an initial 'probe' to define the serial
2511 flash parameters, followed by read/write/erase/update
2514 The following defaults may be provided by the platform
2515 to handle the common case when only a single serial
2516 flash is present on the system.
2518 CONFIG_SF_DEFAULT_BUS Bus identifier
2519 CONFIG_SF_DEFAULT_CS Chip-select
2520 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2521 CONFIG_SF_DEFAULT_SPEED in Hz
2525 Define this option to include a destructive SPI flash
2528 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2530 Define this option to use the Bank addr/Extended addr
2531 support on SPI flashes which has size > 16Mbytes.
2533 - SystemACE Support:
2536 Adding this option adds support for Xilinx SystemACE
2537 chips attached via some sort of local bus. The address
2538 of the chip must also be defined in the
2539 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2541 #define CONFIG_SYSTEMACE
2542 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2544 When SystemACE support is added, the "ace" device type
2545 becomes available to the fat commands, i.e. fatls.
2547 - TFTP Fixed UDP Port:
2550 If this is defined, the environment variable tftpsrcp
2551 is used to supply the TFTP UDP source port value.
2552 If tftpsrcp isn't defined, the normal pseudo-random port
2553 number generator is used.
2555 Also, the environment variable tftpdstp is used to supply
2556 the TFTP UDP destination port value. If tftpdstp isn't
2557 defined, the normal port 69 is used.
2559 The purpose for tftpsrcp is to allow a TFTP server to
2560 blindly start the TFTP transfer using the pre-configured
2561 target IP address and UDP port. This has the effect of
2562 "punching through" the (Windows XP) firewall, allowing
2563 the remainder of the TFTP transfer to proceed normally.
2564 A better solution is to properly configure the firewall,
2565 but sometimes that is not allowed.
2570 This enables a generic 'hash' command which can produce
2571 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2575 Enable the hash verify command (hash -v). This adds to code
2578 CONFIG_SHA1 - support SHA1 hashing
2579 CONFIG_SHA256 - support SHA256 hashing
2581 Note: There is also a sha1sum command, which should perhaps
2582 be deprecated in favour of 'hash sha1'.
2584 - Show boot progress:
2585 CONFIG_SHOW_BOOT_PROGRESS
2587 Defining this option allows to add some board-
2588 specific code (calling a user-provided function
2589 "show_boot_progress(int)") that enables you to show
2590 the system's boot progress on some display (for
2591 example, some LED's) on your board. At the moment,
2592 the following checkpoints are implemented:
2594 - Detailed boot stage timing
2596 Define this option to get detailed timing of each stage
2597 of the boot process.
2599 CONFIG_BOOTSTAGE_USER_COUNT
2600 This is the number of available user bootstage records.
2601 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2602 a new ID will be allocated from this stash. If you exceed
2603 the limit, recording will stop.
2605 CONFIG_BOOTSTAGE_REPORT
2606 Define this to print a report before boot, similar to this:
2608 Timer summary in microseconds:
2611 3,575,678 3,575,678 board_init_f start
2612 3,575,695 17 arch_cpu_init A9
2613 3,575,777 82 arch_cpu_init done
2614 3,659,598 83,821 board_init_r start
2615 3,910,375 250,777 main_loop
2616 29,916,167 26,005,792 bootm_start
2617 30,361,327 445,160 start_kernel
2619 CONFIG_CMD_BOOTSTAGE
2620 Add a 'bootstage' command which supports printing a report
2621 and un/stashing of bootstage data.
2623 CONFIG_BOOTSTAGE_FDT
2624 Stash the bootstage information in the FDT. A root 'bootstage'
2625 node is created with each bootstage id as a child. Each child
2626 has a 'name' property and either 'mark' containing the
2627 mark time in microsecond, or 'accum' containing the
2628 accumulated time for that bootstage id in microseconds.
2633 name = "board_init_f";
2642 Code in the Linux kernel can find this in /proc/devicetree.
2644 Legacy uImage format:
2647 1 common/cmd_bootm.c before attempting to boot an image
2648 -1 common/cmd_bootm.c Image header has bad magic number
2649 2 common/cmd_bootm.c Image header has correct magic number
2650 -2 common/cmd_bootm.c Image header has bad checksum
2651 3 common/cmd_bootm.c Image header has correct checksum
2652 -3 common/cmd_bootm.c Image data has bad checksum
2653 4 common/cmd_bootm.c Image data has correct checksum
2654 -4 common/cmd_bootm.c Image is for unsupported architecture
2655 5 common/cmd_bootm.c Architecture check OK
2656 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2657 6 common/cmd_bootm.c Image Type check OK
2658 -6 common/cmd_bootm.c gunzip uncompression error
2659 -7 common/cmd_bootm.c Unimplemented compression type
2660 7 common/cmd_bootm.c Uncompression OK
2661 8 common/cmd_bootm.c No uncompress/copy overwrite error
2662 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2664 9 common/image.c Start initial ramdisk verification
2665 -10 common/image.c Ramdisk header has bad magic number
2666 -11 common/image.c Ramdisk header has bad checksum
2667 10 common/image.c Ramdisk header is OK
2668 -12 common/image.c Ramdisk data has bad checksum
2669 11 common/image.c Ramdisk data has correct checksum
2670 12 common/image.c Ramdisk verification complete, start loading
2671 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2672 13 common/image.c Start multifile image verification
2673 14 common/image.c No initial ramdisk, no multifile, continue.
2675 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2677 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2678 -31 post/post.c POST test failed, detected by post_output_backlog()
2679 -32 post/post.c POST test failed, detected by post_run_single()
2681 34 common/cmd_doc.c before loading a Image from a DOC device
2682 -35 common/cmd_doc.c Bad usage of "doc" command
2683 35 common/cmd_doc.c correct usage of "doc" command
2684 -36 common/cmd_doc.c No boot device
2685 36 common/cmd_doc.c correct boot device
2686 -37 common/cmd_doc.c Unknown Chip ID on boot device
2687 37 common/cmd_doc.c correct chip ID found, device available
2688 -38 common/cmd_doc.c Read Error on boot device
2689 38 common/cmd_doc.c reading Image header from DOC device OK
2690 -39 common/cmd_doc.c Image header has bad magic number
2691 39 common/cmd_doc.c Image header has correct magic number
2692 -40 common/cmd_doc.c Error reading Image from DOC device
2693 40 common/cmd_doc.c Image header has correct magic number
2694 41 common/cmd_ide.c before loading a Image from a IDE device
2695 -42 common/cmd_ide.c Bad usage of "ide" command
2696 42 common/cmd_ide.c correct usage of "ide" command
2697 -43 common/cmd_ide.c No boot device
2698 43 common/cmd_ide.c boot device found
2699 -44 common/cmd_ide.c Device not available
2700 44 common/cmd_ide.c Device available
2701 -45 common/cmd_ide.c wrong partition selected
2702 45 common/cmd_ide.c partition selected
2703 -46 common/cmd_ide.c Unknown partition table
2704 46 common/cmd_ide.c valid partition table found
2705 -47 common/cmd_ide.c Invalid partition type
2706 47 common/cmd_ide.c correct partition type
2707 -48 common/cmd_ide.c Error reading Image Header on boot device
2708 48 common/cmd_ide.c reading Image Header from IDE device OK
2709 -49 common/cmd_ide.c Image header has bad magic number
2710 49 common/cmd_ide.c Image header has correct magic number
2711 -50 common/cmd_ide.c Image header has bad checksum
2712 50 common/cmd_ide.c Image header has correct checksum
2713 -51 common/cmd_ide.c Error reading Image from IDE device
2714 51 common/cmd_ide.c reading Image from IDE device OK
2715 52 common/cmd_nand.c before loading a Image from a NAND device
2716 -53 common/cmd_nand.c Bad usage of "nand" command
2717 53 common/cmd_nand.c correct usage of "nand" command
2718 -54 common/cmd_nand.c No boot device
2719 54 common/cmd_nand.c boot device found
2720 -55 common/cmd_nand.c Unknown Chip ID on boot device
2721 55 common/cmd_nand.c correct chip ID found, device available
2722 -56 common/cmd_nand.c Error reading Image Header on boot device
2723 56 common/cmd_nand.c reading Image Header from NAND device OK
2724 -57 common/cmd_nand.c Image header has bad magic number
2725 57 common/cmd_nand.c Image header has correct magic number
2726 -58 common/cmd_nand.c Error reading Image from NAND device
2727 58 common/cmd_nand.c reading Image from NAND device OK
2729 -60 common/env_common.c Environment has a bad CRC, using default
2731 64 net/eth.c starting with Ethernet configuration.
2732 -64 net/eth.c no Ethernet found.
2733 65 net/eth.c Ethernet found.
2735 -80 common/cmd_net.c usage wrong
2736 80 common/cmd_net.c before calling NetLoop()
2737 -81 common/cmd_net.c some error in NetLoop() occurred
2738 81 common/cmd_net.c NetLoop() back without error
2739 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2740 82 common/cmd_net.c trying automatic boot
2741 83 common/cmd_net.c running "source" command
2742 -83 common/cmd_net.c some error in automatic boot or "source" command
2743 84 common/cmd_net.c end without errors
2748 100 common/cmd_bootm.c Kernel FIT Image has correct format
2749 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2750 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2751 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2752 102 common/cmd_bootm.c Kernel unit name specified
2753 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2754 103 common/cmd_bootm.c Found configuration node
2755 104 common/cmd_bootm.c Got kernel subimage node offset
2756 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2757 105 common/cmd_bootm.c Kernel subimage hash verification OK
2758 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2759 106 common/cmd_bootm.c Architecture check OK
2760 -106 common/cmd_bootm.c Kernel subimage has wrong type
2761 107 common/cmd_bootm.c Kernel subimage type OK
2762 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2763 108 common/cmd_bootm.c Got kernel subimage data/size
2764 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2765 -109 common/cmd_bootm.c Can't get kernel subimage type
2766 -110 common/cmd_bootm.c Can't get kernel subimage comp
2767 -111 common/cmd_bootm.c Can't get kernel subimage os
2768 -112 common/cmd_bootm.c Can't get kernel subimage load address
2769 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2771 120 common/image.c Start initial ramdisk verification
2772 -120 common/image.c Ramdisk FIT image has incorrect format
2773 121 common/image.c Ramdisk FIT image has correct format
2774 122 common/image.c No ramdisk subimage unit name, using configuration
2775 -122 common/image.c Can't get configuration for ramdisk subimage
2776 123 common/image.c Ramdisk unit name specified
2777 -124 common/image.c Can't get ramdisk subimage node offset
2778 125 common/image.c Got ramdisk subimage node offset
2779 -125 common/image.c Ramdisk subimage hash verification failed
2780 126 common/image.c Ramdisk subimage hash verification OK
2781 -126 common/image.c Ramdisk subimage for unsupported architecture
2782 127 common/image.c Architecture check OK
2783 -127 common/image.c Can't get ramdisk subimage data/size
2784 128 common/image.c Got ramdisk subimage data/size
2785 129 common/image.c Can't get ramdisk load address
2786 -129 common/image.c Got ramdisk load address
2788 -130 common/cmd_doc.c Incorrect FIT image format
2789 131 common/cmd_doc.c FIT image format OK
2791 -140 common/cmd_ide.c Incorrect FIT image format
2792 141 common/cmd_ide.c FIT image format OK
2794 -150 common/cmd_nand.c Incorrect FIT image format
2795 151 common/cmd_nand.c FIT image format OK
2797 - FIT image support:
2799 Enable support for the FIT uImage format.
2801 CONFIG_FIT_BEST_MATCH
2802 When no configuration is explicitly selected, default to the
2803 one whose fdt's compatibility field best matches that of
2804 U-Boot itself. A match is considered "best" if it matches the
2805 most specific compatibility entry of U-Boot's fdt's root node.
2806 The order of entries in the configuration's fdt is ignored.
2808 - Standalone program support:
2809 CONFIG_STANDALONE_LOAD_ADDR
2811 This option defines a board specific value for the
2812 address where standalone program gets loaded, thus
2813 overwriting the architecture dependent default
2816 - Frame Buffer Address:
2819 Define CONFIG_FB_ADDR if you want to use specific
2820 address for frame buffer. This is typically the case
2821 when using a graphics controller has separate video
2822 memory. U-Boot will then place the frame buffer at
2823 the given address instead of dynamically reserving it
2824 in system RAM by calling lcd_setmem(), which grabs
2825 the memory for the frame buffer depending on the
2826 configured panel size.
2828 Please see board_init_f function.
2830 - Automatic software updates via TFTP server
2832 CONFIG_UPDATE_TFTP_CNT_MAX
2833 CONFIG_UPDATE_TFTP_MSEC_MAX
2835 These options enable and control the auto-update feature;
2836 for a more detailed description refer to doc/README.update.
2838 - MTD Support (mtdparts command, UBI support)
2841 Adds the MTD device infrastructure from the Linux kernel.
2842 Needed for mtdparts command support.
2844 CONFIG_MTD_PARTITIONS
2846 Adds the MTD partitioning infrastructure from the Linux
2847 kernel. Needed for UBI support.
2852 Adds commands for interacting with MTD partitions formatted
2853 with the UBI flash translation layer
2855 Requires also defining CONFIG_RBTREE
2857 CONFIG_UBI_SILENCE_MSG
2859 Make the verbose messages from UBI stop printing. This leaves
2860 warnings and errors enabled.
2865 Adds commands for interacting with UBI volumes formatted as
2866 UBIFS. UBIFS is read-only in u-boot.
2868 Requires UBI support as well as CONFIG_LZO
2870 CONFIG_UBIFS_SILENCE_MSG
2872 Make the verbose messages from UBIFS stop printing. This leaves
2873 warnings and errors enabled.
2877 Enable building of SPL globally.
2880 LDSCRIPT for linking the SPL binary.
2882 CONFIG_SPL_MAX_FOOTPRINT
2883 Maximum size in memory allocated to the SPL, BSS included.
2884 When defined, the linker checks that the actual memory
2885 used by SPL from _start to __bss_end does not exceed it.
2886 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2887 must not be both defined at the same time.
2890 Maximum size of the SPL image (text, data, rodata, and
2891 linker lists sections), BSS excluded.
2892 When defined, the linker checks that the actual size does
2895 CONFIG_SPL_TEXT_BASE
2896 TEXT_BASE for linking the SPL binary.
2898 CONFIG_SPL_RELOC_TEXT_BASE
2899 Address to relocate to. If unspecified, this is equal to
2900 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2902 CONFIG_SPL_BSS_START_ADDR
2903 Link address for the BSS within the SPL binary.
2905 CONFIG_SPL_BSS_MAX_SIZE
2906 Maximum size in memory allocated to the SPL BSS.
2907 When defined, the linker checks that the actual memory used
2908 by SPL from __bss_start to __bss_end does not exceed it.
2909 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2910 must not be both defined at the same time.
2913 Adress of the start of the stack SPL will use
2915 CONFIG_SPL_RELOC_STACK
2916 Adress of the start of the stack SPL will use after
2917 relocation. If unspecified, this is equal to
2920 CONFIG_SYS_SPL_MALLOC_START
2921 Starting address of the malloc pool used in SPL.
2923 CONFIG_SYS_SPL_MALLOC_SIZE
2924 The size of the malloc pool used in SPL.
2926 CONFIG_SPL_FRAMEWORK
2927 Enable the SPL framework under common/. This framework
2928 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2929 NAND loading of the Linux Kernel.
2931 CONFIG_SPL_DISPLAY_PRINT
2932 For ARM, enable an optional function to print more information
2933 about the running system.
2935 CONFIG_SPL_INIT_MINIMAL
2936 Arch init code should be built for a very small image
2938 CONFIG_SPL_LIBCOMMON_SUPPORT
2939 Support for common/libcommon.o in SPL binary
2941 CONFIG_SPL_LIBDISK_SUPPORT
2942 Support for disk/libdisk.o in SPL binary
2944 CONFIG_SPL_I2C_SUPPORT
2945 Support for drivers/i2c/libi2c.o in SPL binary
2947 CONFIG_SPL_GPIO_SUPPORT
2948 Support for drivers/gpio/libgpio.o in SPL binary
2950 CONFIG_SPL_MMC_SUPPORT
2951 Support for drivers/mmc/libmmc.o in SPL binary
2953 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2954 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2955 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2956 Address, size and partition on the MMC to load U-Boot from
2957 when the MMC is being used in raw mode.
2959 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2960 Sector to load kernel uImage from when MMC is being
2961 used in raw mode (for Falcon mode)
2963 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2964 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2965 Sector and number of sectors to load kernel argument
2966 parameters from when MMC is being used in raw mode
2969 CONFIG_SPL_FAT_SUPPORT
2970 Support for fs/fat/libfat.o in SPL binary
2972 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2973 Filename to read to load U-Boot when reading from FAT
2975 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
2976 Filename to read to load kernel uImage when reading
2977 from FAT (for Falcon mode)
2979 CONFIG_SPL_FAT_LOAD_ARGS_NAME
2980 Filename to read to load kernel argument parameters
2981 when reading from FAT (for Falcon mode)
2983 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2984 Set this for NAND SPL on PPC mpc83xx targets, so that
2985 start.S waits for the rest of the SPL to load before
2986 continuing (the hardware starts execution after just
2987 loading the first page rather than the full 4K).
2989 CONFIG_SPL_NAND_BASE
2990 Include nand_base.c in the SPL. Requires
2991 CONFIG_SPL_NAND_DRIVERS.
2993 CONFIG_SPL_NAND_DRIVERS
2994 SPL uses normal NAND drivers, not minimal drivers.
2997 Include standard software ECC in the SPL
2999 CONFIG_SPL_NAND_SIMPLE
3000 Support for NAND boot using simple NAND drivers that
3001 expose the cmd_ctrl() interface.
3003 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3004 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3005 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3006 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3007 CONFIG_SYS_NAND_ECCBYTES
3008 Defines the size and behavior of the NAND that SPL uses
3011 CONFIG_SYS_NAND_U_BOOT_OFFS
3012 Location in NAND to read U-Boot from
3014 CONFIG_SYS_NAND_U_BOOT_DST
3015 Location in memory to load U-Boot to
3017 CONFIG_SYS_NAND_U_BOOT_SIZE
3018 Size of image to load
3020 CONFIG_SYS_NAND_U_BOOT_START
3021 Entry point in loaded image to jump to
3023 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3024 Define this if you need to first read the OOB and then the
3025 data. This is used for example on davinci plattforms.
3027 CONFIG_SPL_OMAP3_ID_NAND
3028 Support for an OMAP3-specific set of functions to return the
3029 ID and MFR of the first attached NAND chip, if present.
3031 CONFIG_SPL_SERIAL_SUPPORT
3032 Support for drivers/serial/libserial.o in SPL binary
3034 CONFIG_SPL_SPI_FLASH_SUPPORT
3035 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3037 CONFIG_SPL_SPI_SUPPORT
3038 Support for drivers/spi/libspi.o in SPL binary
3040 CONFIG_SPL_RAM_DEVICE
3041 Support for running image already present in ram, in SPL binary
3043 CONFIG_SPL_LIBGENERIC_SUPPORT
3044 Support for lib/libgeneric.o in SPL binary
3046 CONFIG_SPL_ENV_SUPPORT
3047 Support for the environment operating in SPL binary
3049 CONFIG_SPL_NET_SUPPORT
3050 Support for the net/libnet.o in SPL binary.
3051 It conflicts with SPL env from storage medium specified by
3052 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3055 Image offset to which the SPL should be padded before appending
3056 the SPL payload. By default, this is defined as
3057 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3058 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3059 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3062 Final target image containing SPL and payload. Some SPLs
3063 use an arch-specific makefile fragment instead, for
3064 example if more than one image needs to be produced.
3066 CONFIG_FIT_SPL_PRINT
3067 Printing information about a FIT image adds quite a bit of
3068 code to SPL. So this is normally disabled in SPL. Use this
3069 option to re-enable it. This will affect the output of the
3070 bootm command when booting a FIT image.
3075 [so far only for SMDK2400 boards]
3077 - Modem support enable:
3078 CONFIG_MODEM_SUPPORT
3080 - RTS/CTS Flow control enable:
3083 - Modem debug support:
3084 CONFIG_MODEM_SUPPORT_DEBUG
3086 Enables debugging stuff (char screen[1024], dbg())
3087 for modem support. Useful only with BDI2000.
3089 - Interrupt support (PPC):
3091 There are common interrupt_init() and timer_interrupt()
3092 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3093 for CPU specific initialization. interrupt_init_cpu()
3094 should set decrementer_count to appropriate value. If
3095 CPU resets decrementer automatically after interrupt
3096 (ppc4xx) it should set decrementer_count to zero.
3097 timer_interrupt() calls timer_interrupt_cpu() for CPU
3098 specific handling. If board has watchdog / status_led
3099 / other_activity_monitor it works automatically from
3100 general timer_interrupt().
3104 In the target system modem support is enabled when a
3105 specific key (key combination) is pressed during
3106 power-on. Otherwise U-Boot will boot normally
3107 (autoboot). The key_pressed() function is called from
3108 board_init(). Currently key_pressed() is a dummy
3109 function, returning 1 and thus enabling modem
3112 If there are no modem init strings in the
3113 environment, U-Boot proceed to autoboot; the
3114 previous output (banner, info printfs) will be
3117 See also: doc/README.Modem
3119 Board initialization settings:
3120 ------------------------------
3122 During Initialization u-boot calls a number of board specific functions
3123 to allow the preparation of board specific prerequisites, e.g. pin setup
3124 before drivers are initialized. To enable these callbacks the
3125 following configuration macros have to be defined. Currently this is
3126 architecture specific, so please check arch/your_architecture/lib/board.c
3127 typically in board_init_f() and board_init_r().
3129 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3130 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3131 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3132 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3134 Configuration Settings:
3135 -----------------------
3137 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3138 undefine this when you're short of memory.
3140 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3141 width of the commands listed in the 'help' command output.
3143 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3144 prompt for user input.
3146 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3148 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3150 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3152 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3153 the application (usually a Linux kernel) when it is
3156 - CONFIG_SYS_BAUDRATE_TABLE:
3157 List of legal baudrate settings for this board.
3159 - CONFIG_SYS_CONSOLE_INFO_QUIET
3160 Suppress display of console information at boot.
3162 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3163 If the board specific function
3164 extern int overwrite_console (void);
3165 returns 1, the stdin, stderr and stdout are switched to the
3166 serial port, else the settings in the environment are used.
3168 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3169 Enable the call to overwrite_console().
3171 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3172 Enable overwrite of previous console environment settings.
3174 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3175 Begin and End addresses of the area used by the
3178 - CONFIG_SYS_ALT_MEMTEST:
3179 Enable an alternate, more extensive memory test.
3181 - CONFIG_SYS_MEMTEST_SCRATCH:
3182 Scratch address used by the alternate memory test
3183 You only need to set this if address zero isn't writeable
3185 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3186 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3187 this specified memory area will get subtracted from the top
3188 (end) of RAM and won't get "touched" at all by U-Boot. By
3189 fixing up gd->ram_size the Linux kernel should gets passed
3190 the now "corrected" memory size and won't touch it either.
3191 This should work for arch/ppc and arch/powerpc. Only Linux
3192 board ports in arch/powerpc with bootwrapper support that
3193 recalculate the memory size from the SDRAM controller setup
3194 will have to get fixed in Linux additionally.
3196 This option can be used as a workaround for the 440EPx/GRx
3197 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3200 WARNING: Please make sure that this value is a multiple of
3201 the Linux page size (normally 4k). If this is not the case,
3202 then the end address of the Linux memory will be located at a
3203 non page size aligned address and this could cause major
3206 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3207 Enable temporary baudrate change while serial download
3209 - CONFIG_SYS_SDRAM_BASE:
3210 Physical start address of SDRAM. _Must_ be 0 here.
3212 - CONFIG_SYS_MBIO_BASE:
3213 Physical start address of Motherboard I/O (if using a
3216 - CONFIG_SYS_FLASH_BASE:
3217 Physical start address of Flash memory.
3219 - CONFIG_SYS_MONITOR_BASE:
3220 Physical start address of boot monitor code (set by
3221 make config files to be same as the text base address
3222 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3223 CONFIG_SYS_FLASH_BASE when booting from flash.
3225 - CONFIG_SYS_MONITOR_LEN:
3226 Size of memory reserved for monitor code, used to
3227 determine _at_compile_time_ (!) if the environment is
3228 embedded within the U-Boot image, or in a separate
3231 - CONFIG_SYS_MALLOC_LEN:
3232 Size of DRAM reserved for malloc() use.
3234 - CONFIG_SYS_BOOTM_LEN:
3235 Normally compressed uImages are limited to an
3236 uncompressed size of 8 MBytes. If this is not enough,
3237 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3238 to adjust this setting to your needs.
3240 - CONFIG_SYS_BOOTMAPSZ:
3241 Maximum size of memory mapped by the startup code of
3242 the Linux kernel; all data that must be processed by
3243 the Linux kernel (bd_info, boot arguments, FDT blob if
3244 used) must be put below this limit, unless "bootm_low"
3245 enviroment variable is defined and non-zero. In such case
3246 all data for the Linux kernel must be between "bootm_low"
3247 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3248 variable "bootm_mapsize" will override the value of
3249 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3250 then the value in "bootm_size" will be used instead.
3252 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3253 Enable initrd_high functionality. If defined then the
3254 initrd_high feature is enabled and the bootm ramdisk subcommand
3257 - CONFIG_SYS_BOOT_GET_CMDLINE:
3258 Enables allocating and saving kernel cmdline in space between
3259 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3261 - CONFIG_SYS_BOOT_GET_KBD:
3262 Enables allocating and saving a kernel copy of the bd_info in
3263 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3265 - CONFIG_SYS_MAX_FLASH_BANKS:
3266 Max number of Flash memory banks
3268 - CONFIG_SYS_MAX_FLASH_SECT:
3269 Max number of sectors on a Flash chip
3271 - CONFIG_SYS_FLASH_ERASE_TOUT:
3272 Timeout for Flash erase operations (in ms)
3274 - CONFIG_SYS_FLASH_WRITE_TOUT:
3275 Timeout for Flash write operations (in ms)
3277 - CONFIG_SYS_FLASH_LOCK_TOUT
3278 Timeout for Flash set sector lock bit operation (in ms)
3280 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3281 Timeout for Flash clear lock bits operation (in ms)
3283 - CONFIG_SYS_FLASH_PROTECTION
3284 If defined, hardware flash sectors protection is used
3285 instead of U-Boot software protection.
3287 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3289 Enable TFTP transfers directly to flash memory;
3290 without this option such a download has to be
3291 performed in two steps: (1) download to RAM, and (2)
3292 copy from RAM to flash.
3294 The two-step approach is usually more reliable, since
3295 you can check if the download worked before you erase
3296 the flash, but in some situations (when system RAM is
3297 too limited to allow for a temporary copy of the
3298 downloaded image) this option may be very useful.
3300 - CONFIG_SYS_FLASH_CFI:
3301 Define if the flash driver uses extra elements in the
3302 common flash structure for storing flash geometry.
3304 - CONFIG_FLASH_CFI_DRIVER
3305 This option also enables the building of the cfi_flash driver
3306 in the drivers directory
3308 - CONFIG_FLASH_CFI_MTD
3309 This option enables the building of the cfi_mtd driver
3310 in the drivers directory. The driver exports CFI flash
3313 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3314 Use buffered writes to flash.
3316 - CONFIG_FLASH_SPANSION_S29WS_N
3317 s29ws-n MirrorBit flash has non-standard addresses for buffered
3320 - CONFIG_SYS_FLASH_QUIET_TEST
3321 If this option is defined, the common CFI flash doesn't
3322 print it's warning upon not recognized FLASH banks. This
3323 is useful, if some of the configured banks are only
3324 optionally available.
3326 - CONFIG_FLASH_SHOW_PROGRESS
3327 If defined (must be an integer), print out countdown
3328 digits and dots. Recommended value: 45 (9..1) for 80
3329 column displays, 15 (3..1) for 40 column displays.
3331 - CONFIG_FLASH_VERIFY
3332 If defined, the content of the flash (destination) is compared
3333 against the source after the write operation. An error message
3334 will be printed when the contents are not identical.
3335 Please note that this option is useless in nearly all cases,
3336 since such flash programming errors usually are detected earlier
3337 while unprotecting/erasing/programming. Please only enable
3338 this option if you really know what you are doing.
3340 - CONFIG_SYS_RX_ETH_BUFFER:
3341 Defines the number of Ethernet receive buffers. On some
3342 Ethernet controllers it is recommended to set this value
3343 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3344 buffers can be full shortly after enabling the interface
3345 on high Ethernet traffic.
3346 Defaults to 4 if not defined.
3348 - CONFIG_ENV_MAX_ENTRIES
3350 Maximum number of entries in the hash table that is used
3351 internally to store the environment settings. The default
3352 setting is supposed to be generous and should work in most
3353 cases. This setting can be used to tune behaviour; see
3354 lib/hashtable.c for details.
3356 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3357 - CONFIG_ENV_FLAGS_LIST_STATIC
3358 Enable validation of the values given to enviroment variables when
3359 calling env set. Variables can be restricted to only decimal,
3360 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3361 the variables can also be restricted to IP address or MAC address.
3363 The format of the list is:
3364 type_attribute = [s|d|x|b|i|m]
3365 access_atribute = [a|r|o|c]
3366 attributes = type_attribute[access_atribute]
3367 entry = variable_name[:attributes]
3370 The type attributes are:
3371 s - String (default)
3374 b - Boolean ([1yYtT|0nNfF])
3378 The access attributes are:
3384 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3385 Define this to a list (string) to define the ".flags"
3386 envirnoment variable in the default or embedded environment.
3388 - CONFIG_ENV_FLAGS_LIST_STATIC
3389 Define this to a list (string) to define validation that
3390 should be done if an entry is not found in the ".flags"
3391 environment variable. To override a setting in the static
3392 list, simply add an entry for the same variable name to the
3395 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3396 If defined, don't allow the -f switch to env set override variable
3399 - CONFIG_SYS_GENERIC_BOARD
3400 This selects the architecture-generic board system instead of the
3401 architecture-specific board files. It is intended to move boards
3402 to this new framework over time. Defining this will disable the
3403 arch/foo/lib/board.c file and use common/board_f.c and
3404 common/board_r.c instead. To use this option your architecture
3405 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3406 its config.mk file). If you find problems enabling this option on
3407 your board please report the problem and send patches!
3409 - CONFIG_SYS_SYM_OFFSETS
3410 This is set by architectures that use offsets for link symbols
3411 instead of absolute values. So bss_start is obtained using an
3412 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3413 directly. You should not need to touch this setting.
3415 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3416 This is set by OMAP boards for the max time that reset should
3417 be asserted. See doc/README.omap-reset-time for details on how
3418 the value can be calulated on a given board.
3420 The following definitions that deal with the placement and management
3421 of environment data (variable area); in general, we support the
3422 following configurations:
3424 - CONFIG_BUILD_ENVCRC:
3426 Builds up envcrc with the target environment so that external utils
3427 may easily extract it and embed it in final U-Boot images.
3429 - CONFIG_ENV_IS_IN_FLASH:
3431 Define this if the environment is in flash memory.
3433 a) The environment occupies one whole flash sector, which is
3434 "embedded" in the text segment with the U-Boot code. This
3435 happens usually with "bottom boot sector" or "top boot
3436 sector" type flash chips, which have several smaller
3437 sectors at the start or the end. For instance, such a
3438 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3439 such a case you would place the environment in one of the
3440 4 kB sectors - with U-Boot code before and after it. With
3441 "top boot sector" type flash chips, you would put the
3442 environment in one of the last sectors, leaving a gap
3443 between U-Boot and the environment.
3445 - CONFIG_ENV_OFFSET:
3447 Offset of environment data (variable area) to the
3448 beginning of flash memory; for instance, with bottom boot
3449 type flash chips the second sector can be used: the offset
3450 for this sector is given here.
3452 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3456 This is just another way to specify the start address of
3457 the flash sector containing the environment (instead of
3460 - CONFIG_ENV_SECT_SIZE:
3462 Size of the sector containing the environment.
3465 b) Sometimes flash chips have few, equal sized, BIG sectors.
3466 In such a case you don't want to spend a whole sector for
3471 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3472 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3473 of this flash sector for the environment. This saves
3474 memory for the RAM copy of the environment.
3476 It may also save flash memory if you decide to use this
3477 when your environment is "embedded" within U-Boot code,
3478 since then the remainder of the flash sector could be used
3479 for U-Boot code. It should be pointed out that this is
3480 STRONGLY DISCOURAGED from a robustness point of view:
3481 updating the environment in flash makes it always
3482 necessary to erase the WHOLE sector. If something goes
3483 wrong before the contents has been restored from a copy in
3484 RAM, your target system will be dead.
3486 - CONFIG_ENV_ADDR_REDUND
3487 CONFIG_ENV_SIZE_REDUND
3489 These settings describe a second storage area used to hold
3490 a redundant copy of the environment data, so that there is
3491 a valid backup copy in case there is a power failure during
3492 a "saveenv" operation.
3494 BE CAREFUL! Any changes to the flash layout, and some changes to the
3495 source code will make it necessary to adapt <board>/u-boot.lds*
3499 - CONFIG_ENV_IS_IN_NVRAM:
3501 Define this if you have some non-volatile memory device
3502 (NVRAM, battery buffered SRAM) which you want to use for the
3508 These two #defines are used to determine the memory area you
3509 want to use for environment. It is assumed that this memory
3510 can just be read and written to, without any special
3513 BE CAREFUL! The first access to the environment happens quite early
3514 in U-Boot initalization (when we try to get the setting of for the
3515 console baudrate). You *MUST* have mapped your NVRAM area then, or
3518 Please note that even with NVRAM we still use a copy of the
3519 environment in RAM: we could work on NVRAM directly, but we want to
3520 keep settings there always unmodified except somebody uses "saveenv"
3521 to save the current settings.
3524 - CONFIG_ENV_IS_IN_EEPROM:
3526 Use this if you have an EEPROM or similar serial access
3527 device and a driver for it.
3529 - CONFIG_ENV_OFFSET:
3532 These two #defines specify the offset and size of the
3533 environment area within the total memory of your EEPROM.
3535 - CONFIG_SYS_I2C_EEPROM_ADDR:
3536 If defined, specified the chip address of the EEPROM device.
3537 The default address is zero.
3539 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3540 If defined, the number of bits used to address bytes in a
3541 single page in the EEPROM device. A 64 byte page, for example
3542 would require six bits.
3544 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3545 If defined, the number of milliseconds to delay between
3546 page writes. The default is zero milliseconds.
3548 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3549 The length in bytes of the EEPROM memory array address. Note
3550 that this is NOT the chip address length!
3552 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3553 EEPROM chips that implement "address overflow" are ones
3554 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3555 address and the extra bits end up in the "chip address" bit
3556 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3559 Note that we consider the length of the address field to
3560 still be one byte because the extra address bits are hidden
3561 in the chip address.
3563 - CONFIG_SYS_EEPROM_SIZE:
3564 The size in bytes of the EEPROM device.
3566 - CONFIG_ENV_EEPROM_IS_ON_I2C
3567 define this, if you have I2C and SPI activated, and your
3568 EEPROM, which holds the environment, is on the I2C bus.
3570 - CONFIG_I2C_ENV_EEPROM_BUS
3571 if you have an Environment on an EEPROM reached over
3572 I2C muxes, you can define here, how to reach this
3573 EEPROM. For example:
3575 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3577 EEPROM which holds the environment, is reached over
3578 a pca9547 i2c mux with address 0x70, channel 3.
3580 - CONFIG_ENV_IS_IN_DATAFLASH:
3582 Define this if you have a DataFlash memory device which you
3583 want to use for the environment.
3585 - CONFIG_ENV_OFFSET:
3589 These three #defines specify the offset and size of the
3590 environment area within the total memory of your DataFlash placed
3591 at the specified address.
3593 - CONFIG_ENV_IS_IN_REMOTE:
3595 Define this if you have a remote memory space which you
3596 want to use for the local device's environment.
3601 These two #defines specify the address and size of the
3602 environment area within the remote memory space. The
3603 local device can get the environment from remote memory
3604 space by SRIO or PCIE links.
3606 BE CAREFUL! For some special cases, the local device can not use
3607 "saveenv" command. For example, the local device will get the
3608 environment stored in a remote NOR flash by SRIO or PCIE link,
3609 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3611 - CONFIG_ENV_IS_IN_NAND:
3613 Define this if you have a NAND device which you want to use
3614 for the environment.
3616 - CONFIG_ENV_OFFSET:
3619 These two #defines specify the offset and size of the environment
3620 area within the first NAND device. CONFIG_ENV_OFFSET must be
3621 aligned to an erase block boundary.
3623 - CONFIG_ENV_OFFSET_REDUND (optional):
3625 This setting describes a second storage area of CONFIG_ENV_SIZE
3626 size used to hold a redundant copy of the environment data, so
3627 that there is a valid backup copy in case there is a power failure
3628 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3629 aligned to an erase block boundary.
3631 - CONFIG_ENV_RANGE (optional):
3633 Specifies the length of the region in which the environment
3634 can be written. This should be a multiple of the NAND device's
3635 block size. Specifying a range with more erase blocks than
3636 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3637 the range to be avoided.
3639 - CONFIG_ENV_OFFSET_OOB (optional):
3641 Enables support for dynamically retrieving the offset of the
3642 environment from block zero's out-of-band data. The
3643 "nand env.oob" command can be used to record this offset.
3644 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3645 using CONFIG_ENV_OFFSET_OOB.
3647 - CONFIG_NAND_ENV_DST
3649 Defines address in RAM to which the nand_spl code should copy the
3650 environment. If redundant environment is used, it will be copied to
3651 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3653 - CONFIG_ENV_IS_IN_UBI:
3655 Define this if you have an UBI volume that you want to use for the
3656 environment. This has the benefit of wear-leveling the environment
3657 accesses, which is important on NAND.
3659 - CONFIG_ENV_UBI_PART:
3661 Define this to a string that is the mtd partition containing the UBI.
3663 - CONFIG_ENV_UBI_VOLUME:
3665 Define this to the name of the volume that you want to store the
3668 - CONFIG_ENV_UBI_VOLUME_REDUND:
3670 Define this to the name of another volume to store a second copy of
3671 the environment in. This will enable redundant environments in UBI.
3672 It is assumed that both volumes are in the same MTD partition.
3674 - CONFIG_UBI_SILENCE_MSG
3675 - CONFIG_UBIFS_SILENCE_MSG
3677 You will probably want to define these to avoid a really noisy system
3678 when storing the env in UBI.
3680 - CONFIG_ENV_IS_IN_MMC:
3682 Define this if you have an MMC device which you want to use for the
3685 - CONFIG_SYS_MMC_ENV_DEV:
3687 Specifies which MMC device the environment is stored in.
3689 - CONFIG_SYS_MMC_ENV_PART (optional):
3691 Specifies which MMC partition the environment is stored in. If not
3692 set, defaults to partition 0, the user area. Common values might be
3693 1 (first MMC boot partition), 2 (second MMC boot partition).
3695 - CONFIG_ENV_OFFSET:
3698 These two #defines specify the offset and size of the environment
3699 area within the specified MMC device.
3701 If offset is positive (the usual case), it is treated as relative to
3702 the start of the MMC partition. If offset is negative, it is treated
3703 as relative to the end of the MMC partition. This can be useful if
3704 your board may be fitted with different MMC devices, which have
3705 different sizes for the MMC partitions, and you always want the
3706 environment placed at the very end of the partition, to leave the
3707 maximum possible space before it, to store other data.
3709 These two values are in units of bytes, but must be aligned to an
3710 MMC sector boundary.
3712 - CONFIG_ENV_OFFSET_REDUND (optional):
3714 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3715 hold a redundant copy of the environment data. This provides a
3716 valid backup copy in case the other copy is corrupted, e.g. due
3717 to a power failure during a "saveenv" operation.
3719 This value may also be positive or negative; this is handled in the
3720 same way as CONFIG_ENV_OFFSET.
3722 This value is also in units of bytes, but must also be aligned to
3723 an MMC sector boundary.
3725 - CONFIG_ENV_SIZE_REDUND (optional):
3727 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3728 set. If this value is set, it must be set to the same value as
3731 - CONFIG_SYS_SPI_INIT_OFFSET
3733 Defines offset to the initial SPI buffer area in DPRAM. The
3734 area is used at an early stage (ROM part) if the environment
3735 is configured to reside in the SPI EEPROM: We need a 520 byte
3736 scratch DPRAM area. It is used between the two initialization
3737 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3738 to be a good choice since it makes it far enough from the
3739 start of the data area as well as from the stack pointer.
3741 Please note that the environment is read-only until the monitor
3742 has been relocated to RAM and a RAM copy of the environment has been
3743 created; also, when using EEPROM you will have to use getenv_f()
3744 until then to read environment variables.
3746 The environment is protected by a CRC32 checksum. Before the monitor
3747 is relocated into RAM, as a result of a bad CRC you will be working
3748 with the compiled-in default environment - *silently*!!! [This is
3749 necessary, because the first environment variable we need is the
3750 "baudrate" setting for the console - if we have a bad CRC, we don't
3751 have any device yet where we could complain.]
3753 Note: once the monitor has been relocated, then it will complain if
3754 the default environment is used; a new CRC is computed as soon as you
3755 use the "saveenv" command to store a valid environment.
3757 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3758 Echo the inverted Ethernet link state to the fault LED.
3760 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3761 also needs to be defined.
3763 - CONFIG_SYS_FAULT_MII_ADDR:
3764 MII address of the PHY to check for the Ethernet link state.
3766 - CONFIG_NS16550_MIN_FUNCTIONS:
3767 Define this if you desire to only have use of the NS16550_init
3768 and NS16550_putc functions for the serial driver located at
3769 drivers/serial/ns16550.c. This option is useful for saving
3770 space for already greatly restricted images, including but not
3771 limited to NAND_SPL configurations.
3773 - CONFIG_DISPLAY_BOARDINFO
3774 Display information about the board that U-Boot is running on
3775 when U-Boot starts up. The board function checkboard() is called
3778 - CONFIG_DISPLAY_BOARDINFO_LATE
3779 Similar to the previous option, but display this information
3780 later, once stdio is running and output goes to the LCD, if
3783 Low Level (hardware related) configuration options:
3784 ---------------------------------------------------
3786 - CONFIG_SYS_CACHELINE_SIZE:
3787 Cache Line Size of the CPU.
3789 - CONFIG_SYS_DEFAULT_IMMR:
3790 Default address of the IMMR after system reset.
3792 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3793 and RPXsuper) to be able to adjust the position of
3794 the IMMR register after a reset.
3796 - CONFIG_SYS_CCSRBAR_DEFAULT:
3797 Default (power-on reset) physical address of CCSR on Freescale
3800 - CONFIG_SYS_CCSRBAR:
3801 Virtual address of CCSR. On a 32-bit build, this is typically
3802 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3804 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3805 for cross-platform code that uses that macro instead.
3807 - CONFIG_SYS_CCSRBAR_PHYS:
3808 Physical address of CCSR. CCSR can be relocated to a new
3809 physical address, if desired. In this case, this macro should
3810 be set to that address. Otherwise, it should be set to the
3811 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3812 is typically relocated on 36-bit builds. It is recommended
3813 that this macro be defined via the _HIGH and _LOW macros:
3815 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3816 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3818 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3819 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3820 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3821 used in assembly code, so it must not contain typecasts or
3822 integer size suffixes (e.g. "ULL").
3824 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3825 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3826 used in assembly code, so it must not contain typecasts or
3827 integer size suffixes (e.g. "ULL").
3829 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3830 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3831 forced to a value that ensures that CCSR is not relocated.
3833 - Floppy Disk Support:
3834 CONFIG_SYS_FDC_DRIVE_NUMBER
3836 the default drive number (default value 0)
3838 CONFIG_SYS_ISA_IO_STRIDE
3840 defines the spacing between FDC chipset registers
3843 CONFIG_SYS_ISA_IO_OFFSET
3845 defines the offset of register from address. It
3846 depends on which part of the data bus is connected to
3847 the FDC chipset. (default value 0)
3849 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3850 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3853 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3854 fdc_hw_init() is called at the beginning of the FDC
3855 setup. fdc_hw_init() must be provided by the board
3856 source code. It is used to make hardware dependant
3860 Most IDE controllers were designed to be connected with PCI
3861 interface. Only few of them were designed for AHB interface.
3862 When software is doing ATA command and data transfer to
3863 IDE devices through IDE-AHB controller, some additional
3864 registers accessing to these kind of IDE-AHB controller
3867 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3868 DO NOT CHANGE unless you know exactly what you're
3869 doing! (11-4) [MPC8xx/82xx systems only]
3871 - CONFIG_SYS_INIT_RAM_ADDR:
3873 Start address of memory area that can be used for
3874 initial data and stack; please note that this must be
3875 writable memory that is working WITHOUT special
3876 initialization, i. e. you CANNOT use normal RAM which
3877 will become available only after programming the
3878 memory controller and running certain initialization
3881 U-Boot uses the following memory types:
3882 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3883 - MPC824X: data cache
3884 - PPC4xx: data cache
3886 - CONFIG_SYS_GBL_DATA_OFFSET:
3888 Offset of the initial data structure in the memory
3889 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3890 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3891 data is located at the end of the available space
3892 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3893 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3894 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3895 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3898 On the MPC824X (or other systems that use the data
3899 cache for initial memory) the address chosen for
3900 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3901 point to an otherwise UNUSED address space between
3902 the top of RAM and the start of the PCI space.
3904 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3906 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3908 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3910 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3912 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3914 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3916 - CONFIG_SYS_OR_TIMING_SDRAM:
3919 - CONFIG_SYS_MAMR_PTA:
3920 periodic timer for refresh
3922 - CONFIG_SYS_DER: Debug Event Register (37-47)
3924 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3925 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3926 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3927 CONFIG_SYS_BR1_PRELIM:
3928 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3930 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3931 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3932 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3933 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3935 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3936 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3937 Machine Mode Register and Memory Periodic Timer
3938 Prescaler definitions (SDRAM timing)
3940 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3941 enable I2C microcode relocation patch (MPC8xx);
3942 define relocation offset in DPRAM [DSP2]
3944 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3945 enable SMC microcode relocation patch (MPC8xx);
3946 define relocation offset in DPRAM [SMC1]
3948 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3949 enable SPI microcode relocation patch (MPC8xx);
3950 define relocation offset in DPRAM [SCC4]
3952 - CONFIG_SYS_USE_OSCCLK:
3953 Use OSCM clock mode on MBX8xx board. Be careful,
3954 wrong setting might damage your board. Read
3955 doc/README.MBX before setting this variable!
3957 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3958 Offset of the bootmode word in DPRAM used by post
3959 (Power On Self Tests). This definition overrides
3960 #define'd default value in commproc.h resp.
3963 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3964 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3965 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3966 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3967 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3968 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3969 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3970 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3971 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3973 - CONFIG_PCI_DISABLE_PCIE:
3974 Disable PCI-Express on systems where it is supported but not
3977 - CONFIG_PCI_ENUM_ONLY
3978 Only scan through and get the devices on the busses.
3979 Don't do any setup work, presumably because someone or
3980 something has already done it, and we don't need to do it
3981 a second time. Useful for platforms that are pre-booted
3982 by coreboot or similar.
3984 - CONFIG_PCI_INDIRECT_BRIDGE:
3985 Enable support for indirect PCI bridges.
3988 Chip has SRIO or not
3991 Board has SRIO 1 port available
3994 Board has SRIO 2 port available
3996 - CONFIG_SRIO_PCIE_BOOT_MASTER
3997 Board can support master function for Boot from SRIO and PCIE
3999 - CONFIG_SYS_SRIOn_MEM_VIRT:
4000 Virtual Address of SRIO port 'n' memory region
4002 - CONFIG_SYS_SRIOn_MEM_PHYS:
4003 Physical Address of SRIO port 'n' memory region
4005 - CONFIG_SYS_SRIOn_MEM_SIZE:
4006 Size of SRIO port 'n' memory region
4008 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4009 Defined to tell the NAND controller that the NAND chip is using
4011 Not all NAND drivers use this symbol.
4012 Example of drivers that use it:
4013 - drivers/mtd/nand/ndfc.c
4014 - drivers/mtd/nand/mxc_nand.c
4016 - CONFIG_SYS_NDFC_EBC0_CFG
4017 Sets the EBC0_CFG register for the NDFC. If not defined
4018 a default value will be used.
4021 Get DDR timing information from an I2C EEPROM. Common
4022 with pluggable memory modules such as SODIMMs
4025 I2C address of the SPD EEPROM
4027 - CONFIG_SYS_SPD_BUS_NUM
4028 If SPD EEPROM is on an I2C bus other than the first
4029 one, specify here. Note that the value must resolve
4030 to something your driver can deal with.
4032 - CONFIG_SYS_DDR_RAW_TIMING
4033 Get DDR timing information from other than SPD. Common with
4034 soldered DDR chips onboard without SPD. DDR raw timing
4035 parameters are extracted from datasheet and hard-coded into
4036 header files or board specific files.
4038 - CONFIG_FSL_DDR_INTERACTIVE
4039 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4041 - CONFIG_SYS_83XX_DDR_USES_CS0
4042 Only for 83xx systems. If specified, then DDR should
4043 be configured using CS0 and CS1 instead of CS2 and CS3.
4045 - CONFIG_ETHER_ON_FEC[12]
4046 Define to enable FEC[12] on a 8xx series processor.
4048 - CONFIG_FEC[12]_PHY
4049 Define to the hardcoded PHY address which corresponds
4050 to the given FEC; i. e.
4051 #define CONFIG_FEC1_PHY 4
4052 means that the PHY with address 4 is connected to FEC1
4054 When set to -1, means to probe for first available.
4056 - CONFIG_FEC[12]_PHY_NORXERR
4057 The PHY does not have a RXERR line (RMII only).
4058 (so program the FEC to ignore it).
4061 Enable RMII mode for all FECs.
4062 Note that this is a global option, we can't
4063 have one FEC in standard MII mode and another in RMII mode.
4065 - CONFIG_CRC32_VERIFY
4066 Add a verify option to the crc32 command.
4069 => crc32 -v <address> <count> <crc32>
4071 Where address/count indicate a memory area
4072 and crc32 is the correct crc32 which the
4076 Add the "loopw" memory command. This only takes effect if
4077 the memory commands are activated globally (CONFIG_CMD_MEM).
4080 Add the "mdc" and "mwc" memory commands. These are cyclic
4085 This command will print 4 bytes (10,11,12,13) each 500 ms.
4087 => mwc.l 100 12345678 10
4088 This command will write 12345678 to address 100 all 10 ms.
4090 This only takes effect if the memory commands are activated
4091 globally (CONFIG_CMD_MEM).
4093 - CONFIG_SKIP_LOWLEVEL_INIT
4094 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4095 low level initializations (like setting up the memory
4096 controller) are omitted and/or U-Boot does not
4097 relocate itself into RAM.
4099 Normally this variable MUST NOT be defined. The only
4100 exception is when U-Boot is loaded (to RAM) by some
4101 other boot loader or by a debugger which performs
4102 these initializations itself.
4105 Modifies the behaviour of start.S when compiling a loader
4106 that is executed before the actual U-Boot. E.g. when
4107 compiling a NAND SPL.
4109 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4110 Only for 85xx systems. If this variable is specified, the section
4111 .resetvec is not kept and the section .bootpg is placed in the
4112 previous 4k of the .text section.
4114 - CONFIG_ARCH_MAP_SYSMEM
4115 Generally U-Boot (and in particular the md command) uses
4116 effective address. It is therefore not necessary to regard
4117 U-Boot address as virtual addresses that need to be translated
4118 to physical addresses. However, sandbox requires this, since
4119 it maintains its own little RAM buffer which contains all
4120 addressable memory. This option causes some memory accesses
4121 to be mapped through map_sysmem() / unmap_sysmem().
4123 - CONFIG_USE_ARCH_MEMCPY
4124 CONFIG_USE_ARCH_MEMSET
4125 If these options are used a optimized version of memcpy/memset will
4126 be used if available. These functions may be faster under some
4127 conditions but may increase the binary size.
4129 - CONFIG_X86_RESET_VECTOR
4130 If defined, the x86 reset vector code is included. This is not
4131 needed when U-Boot is running from Coreboot.
4134 Defines the MPU clock speed (in MHz).
4136 NOTE : currently only supported on AM335x platforms.
4138 Freescale QE/FMAN Firmware Support:
4139 -----------------------------------
4141 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4142 loading of "firmware", which is encoded in the QE firmware binary format.
4143 This firmware often needs to be loaded during U-Boot booting, so macros
4144 are used to identify the storage device (NOR flash, SPI, etc) and the address
4147 - CONFIG_SYS_QE_FMAN_FW_ADDR
4148 The address in the storage device where the firmware is located. The
4149 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4152 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4153 The maximum possible size of the firmware. The firmware binary format
4154 has a field that specifies the actual size of the firmware, but it
4155 might not be possible to read any part of the firmware unless some
4156 local storage is allocated to hold the entire firmware first.
4158 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4159 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4160 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4161 virtual address in NOR flash.
4163 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4164 Specifies that QE/FMAN firmware is located in NAND flash.
4165 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4167 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4168 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4169 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4171 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4172 Specifies that QE/FMAN firmware is located on the primary SPI
4173 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4175 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4176 Specifies that QE/FMAN firmware is located in the remote (master)
4177 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4178 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4179 window->master inbound window->master LAW->the ucode address in
4180 master's memory space.
4182 Building the Software:
4183 ======================
4185 Building U-Boot has been tested in several native build environments
4186 and in many different cross environments. Of course we cannot support
4187 all possibly existing versions of cross development tools in all
4188 (potentially obsolete) versions. In case of tool chain problems we
4189 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4190 which is extensively used to build and test U-Boot.
4192 If you are not using a native environment, it is assumed that you
4193 have GNU cross compiling tools available in your path. In this case,
4194 you must set the environment variable CROSS_COMPILE in your shell.
4195 Note that no changes to the Makefile or any other source files are
4196 necessary. For example using the ELDK on a 4xx CPU, please enter:
4198 $ CROSS_COMPILE=ppc_4xx-
4199 $ export CROSS_COMPILE
4201 Note: If you wish to generate Windows versions of the utilities in
4202 the tools directory you can use the MinGW toolchain
4203 (http://www.mingw.org). Set your HOST tools to the MinGW
4204 toolchain and execute 'make tools'. For example:
4206 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4208 Binaries such as tools/mkimage.exe will be created which can
4209 be executed on computers running Windows.
4211 U-Boot is intended to be simple to build. After installing the
4212 sources you must configure U-Boot for one specific board type. This
4217 where "NAME_config" is the name of one of the existing configu-
4218 rations; see boards.cfg for supported names.
4220 Note: for some board special configuration names may exist; check if
4221 additional information is available from the board vendor; for
4222 instance, the TQM823L systems are available without (standard)
4223 or with LCD support. You can select such additional "features"
4224 when choosing the configuration, i. e.
4227 - will configure for a plain TQM823L, i. e. no LCD support
4229 make TQM823L_LCD_config
4230 - will configure for a TQM823L with U-Boot console on LCD
4235 Finally, type "make all", and you should get some working U-Boot
4236 images ready for download to / installation on your system:
4238 - "u-boot.bin" is a raw binary image
4239 - "u-boot" is an image in ELF binary format
4240 - "u-boot.srec" is in Motorola S-Record format
4242 By default the build is performed locally and the objects are saved
4243 in the source directory. One of the two methods can be used to change
4244 this behavior and build U-Boot to some external directory:
4246 1. Add O= to the make command line invocations:
4248 make O=/tmp/build distclean
4249 make O=/tmp/build NAME_config
4250 make O=/tmp/build all
4252 2. Set environment variable BUILD_DIR to point to the desired location:
4254 export BUILD_DIR=/tmp/build
4259 Note that the command line "O=" setting overrides the BUILD_DIR environment
4263 Please be aware that the Makefiles assume you are using GNU make, so
4264 for instance on NetBSD you might need to use "gmake" instead of
4268 If the system board that you have is not listed, then you will need
4269 to port U-Boot to your hardware platform. To do this, follow these
4272 1. Add a new configuration option for your board to the toplevel
4273 "boards.cfg" file, using the existing entries as examples.
4274 Follow the instructions there to keep the boards in order.
4275 2. Create a new directory to hold your board specific code. Add any
4276 files you need. In your board directory, you will need at least
4277 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4278 3. Create a new configuration file "include/configs/<board>.h" for
4280 3. If you're porting U-Boot to a new CPU, then also create a new
4281 directory to hold your CPU specific code. Add any files you need.
4282 4. Run "make <board>_config" with your new name.
4283 5. Type "make", and you should get a working "u-boot.srec" file
4284 to be installed on your target system.
4285 6. Debug and solve any problems that might arise.
4286 [Of course, this last step is much harder than it sounds.]
4289 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4290 ==============================================================
4292 If you have modified U-Boot sources (for instance added a new board
4293 or support for new devices, a new CPU, etc.) you are expected to
4294 provide feedback to the other developers. The feedback normally takes
4295 the form of a "patch", i. e. a context diff against a certain (latest
4296 official or latest in the git repository) version of U-Boot sources.
4298 But before you submit such a patch, please verify that your modifi-
4299 cation did not break existing code. At least make sure that *ALL* of
4300 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4301 just run the "MAKEALL" script, which will configure and build U-Boot
4302 for ALL supported system. Be warned, this will take a while. You can
4303 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4304 environment variable to the script, i. e. to use the ELDK cross tools
4307 CROSS_COMPILE=ppc_8xx- MAKEALL
4309 or to build on a native PowerPC system you can type
4311 CROSS_COMPILE=' ' MAKEALL
4313 When using the MAKEALL script, the default behaviour is to build
4314 U-Boot in the source directory. This location can be changed by
4315 setting the BUILD_DIR environment variable. Also, for each target
4316 built, the MAKEALL script saves two log files (<target>.ERR and
4317 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4318 location can be changed by setting the MAKEALL_LOGDIR environment
4319 variable. For example:
4321 export BUILD_DIR=/tmp/build
4322 export MAKEALL_LOGDIR=/tmp/log
4323 CROSS_COMPILE=ppc_8xx- MAKEALL
4325 With the above settings build objects are saved in the /tmp/build,
4326 log files are saved in the /tmp/log and the source tree remains clean
4327 during the whole build process.
4330 See also "U-Boot Porting Guide" below.
4333 Monitor Commands - Overview:
4334 ============================
4336 go - start application at address 'addr'
4337 run - run commands in an environment variable
4338 bootm - boot application image from memory
4339 bootp - boot image via network using BootP/TFTP protocol
4340 bootz - boot zImage from memory
4341 tftpboot- boot image via network using TFTP protocol
4342 and env variables "ipaddr" and "serverip"
4343 (and eventually "gatewayip")
4344 tftpput - upload a file via network using TFTP protocol
4345 rarpboot- boot image via network using RARP/TFTP protocol
4346 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4347 loads - load S-Record file over serial line
4348 loadb - load binary file over serial line (kermit mode)
4350 mm - memory modify (auto-incrementing)
4351 nm - memory modify (constant address)
4352 mw - memory write (fill)
4354 cmp - memory compare
4355 crc32 - checksum calculation
4356 i2c - I2C sub-system
4357 sspi - SPI utility commands
4358 base - print or set address offset
4359 printenv- print environment variables
4360 setenv - set environment variables
4361 saveenv - save environment variables to persistent storage
4362 protect - enable or disable FLASH write protection
4363 erase - erase FLASH memory
4364 flinfo - print FLASH memory information
4365 nand - NAND memory operations (see doc/README.nand)
4366 bdinfo - print Board Info structure
4367 iminfo - print header information for application image
4368 coninfo - print console devices and informations
4369 ide - IDE sub-system
4370 loop - infinite loop on address range
4371 loopw - infinite write loop on address range
4372 mtest - simple RAM test
4373 icache - enable or disable instruction cache
4374 dcache - enable or disable data cache
4375 reset - Perform RESET of the CPU
4376 echo - echo args to console
4377 version - print monitor version
4378 help - print online help
4379 ? - alias for 'help'
4382 Monitor Commands - Detailed Description:
4383 ========================================
4387 For now: just type "help <command>".
4390 Environment Variables:
4391 ======================
4393 U-Boot supports user configuration using Environment Variables which
4394 can be made persistent by saving to Flash memory.
4396 Environment Variables are set using "setenv", printed using
4397 "printenv", and saved to Flash using "saveenv". Using "setenv"
4398 without a value can be used to delete a variable from the
4399 environment. As long as you don't save the environment you are
4400 working with an in-memory copy. In case the Flash area containing the
4401 environment is erased by accident, a default environment is provided.
4403 Some configuration options can be set using Environment Variables.
4405 List of environment variables (most likely not complete):
4407 baudrate - see CONFIG_BAUDRATE
4409 bootdelay - see CONFIG_BOOTDELAY
4411 bootcmd - see CONFIG_BOOTCOMMAND
4413 bootargs - Boot arguments when booting an RTOS image
4415 bootfile - Name of the image to load with TFTP
4417 bootm_low - Memory range available for image processing in the bootm
4418 command can be restricted. This variable is given as
4419 a hexadecimal number and defines lowest address allowed
4420 for use by the bootm command. See also "bootm_size"
4421 environment variable. Address defined by "bootm_low" is
4422 also the base of the initial memory mapping for the Linux
4423 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4426 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4427 This variable is given as a hexadecimal number and it
4428 defines the size of the memory region starting at base
4429 address bootm_low that is accessible by the Linux kernel
4430 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4431 as the default value if it is defined, and bootm_size is
4434 bootm_size - Memory range available for image processing in the bootm
4435 command can be restricted. This variable is given as
4436 a hexadecimal number and defines the size of the region
4437 allowed for use by the bootm command. See also "bootm_low"
4438 environment variable.
4440 updatefile - Location of the software update file on a TFTP server, used
4441 by the automatic software update feature. Please refer to
4442 documentation in doc/README.update for more details.
4444 autoload - if set to "no" (any string beginning with 'n'),
4445 "bootp" will just load perform a lookup of the
4446 configuration from the BOOTP server, but not try to
4447 load any image using TFTP
4449 autostart - if set to "yes", an image loaded using the "bootp",
4450 "rarpboot", "tftpboot" or "diskboot" commands will
4451 be automatically started (by internally calling
4454 If set to "no", a standalone image passed to the
4455 "bootm" command will be copied to the load address
4456 (and eventually uncompressed), but NOT be started.
4457 This can be used to load and uncompress arbitrary
4460 fdt_high - if set this restricts the maximum address that the
4461 flattened device tree will be copied into upon boot.
4462 For example, if you have a system with 1 GB memory
4463 at physical address 0x10000000, while Linux kernel
4464 only recognizes the first 704 MB as low memory, you
4465 may need to set fdt_high as 0x3C000000 to have the
4466 device tree blob be copied to the maximum address
4467 of the 704 MB low memory, so that Linux kernel can
4468 access it during the boot procedure.
4470 If this is set to the special value 0xFFFFFFFF then
4471 the fdt will not be copied at all on boot. For this
4472 to work it must reside in writable memory, have
4473 sufficient padding on the end of it for u-boot to
4474 add the information it needs into it, and the memory
4475 must be accessible by the kernel.
4477 fdtcontroladdr- if set this is the address of the control flattened
4478 device tree used by U-Boot when CONFIG_OF_CONTROL is
4481 i2cfast - (PPC405GP|PPC405EP only)
4482 if set to 'y' configures Linux I2C driver for fast
4483 mode (400kHZ). This environment variable is used in
4484 initialization code. So, for changes to be effective
4485 it must be saved and board must be reset.
4487 initrd_high - restrict positioning of initrd images:
4488 If this variable is not set, initrd images will be
4489 copied to the highest possible address in RAM; this
4490 is usually what you want since it allows for
4491 maximum initrd size. If for some reason you want to
4492 make sure that the initrd image is loaded below the
4493 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4494 variable to a value of "no" or "off" or "0".
4495 Alternatively, you can set it to a maximum upper
4496 address to use (U-Boot will still check that it
4497 does not overwrite the U-Boot stack and data).
4499 For instance, when you have a system with 16 MB
4500 RAM, and want to reserve 4 MB from use by Linux,
4501 you can do this by adding "mem=12M" to the value of
4502 the "bootargs" variable. However, now you must make
4503 sure that the initrd image is placed in the first
4504 12 MB as well - this can be done with
4506 setenv initrd_high 00c00000
4508 If you set initrd_high to 0xFFFFFFFF, this is an
4509 indication to U-Boot that all addresses are legal
4510 for the Linux kernel, including addresses in flash
4511 memory. In this case U-Boot will NOT COPY the
4512 ramdisk at all. This may be useful to reduce the
4513 boot time on your system, but requires that this
4514 feature is supported by your Linux kernel.
4516 ipaddr - IP address; needed for tftpboot command
4518 loadaddr - Default load address for commands like "bootp",
4519 "rarpboot", "tftpboot", "loadb" or "diskboot"
4521 loads_echo - see CONFIG_LOADS_ECHO
4523 serverip - TFTP server IP address; needed for tftpboot command
4525 bootretry - see CONFIG_BOOT_RETRY_TIME
4527 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4529 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4531 ethprime - controls which interface is used first.
4533 ethact - controls which interface is currently active.
4534 For example you can do the following
4536 => setenv ethact FEC
4537 => ping 192.168.0.1 # traffic sent on FEC
4538 => setenv ethact SCC
4539 => ping 10.0.0.1 # traffic sent on SCC
4541 ethrotate - When set to "no" U-Boot does not go through all
4542 available network interfaces.
4543 It just stays at the currently selected interface.
4545 netretry - When set to "no" each network operation will
4546 either succeed or fail without retrying.
4547 When set to "once" the network operation will
4548 fail when all the available network interfaces
4549 are tried once without success.
4550 Useful on scripts which control the retry operation
4553 npe_ucode - set load address for the NPE microcode
4555 tftpsrcport - If this is set, the value is used for TFTP's
4558 tftpdstport - If this is set, the value is used for TFTP's UDP
4559 destination port instead of the Well Know Port 69.
4561 tftpblocksize - Block size to use for TFTP transfers; if not set,
4562 we use the TFTP server's default block size
4564 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4565 seconds, minimum value is 1000 = 1 second). Defines
4566 when a packet is considered to be lost so it has to
4567 be retransmitted. The default is 5000 = 5 seconds.
4568 Lowering this value may make downloads succeed
4569 faster in networks with high packet loss rates or
4570 with unreliable TFTP servers.
4572 vlan - When set to a value < 4095 the traffic over
4573 Ethernet is encapsulated/received over 802.1q
4576 The following image location variables contain the location of images
4577 used in booting. The "Image" column gives the role of the image and is
4578 not an environment variable name. The other columns are environment
4579 variable names. "File Name" gives the name of the file on a TFTP
4580 server, "RAM Address" gives the location in RAM the image will be
4581 loaded to, and "Flash Location" gives the image's address in NOR
4582 flash or offset in NAND flash.
4584 *Note* - these variables don't have to be defined for all boards, some
4585 boards currenlty use other variables for these purposes, and some
4586 boards use these variables for other purposes.
4588 Image File Name RAM Address Flash Location
4589 ----- --------- ----------- --------------
4590 u-boot u-boot u-boot_addr_r u-boot_addr
4591 Linux kernel bootfile kernel_addr_r kernel_addr
4592 device tree blob fdtfile fdt_addr_r fdt_addr
4593 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4595 The following environment variables may be used and automatically
4596 updated by the network boot commands ("bootp" and "rarpboot"),
4597 depending the information provided by your boot server:
4599 bootfile - see above
4600 dnsip - IP address of your Domain Name Server
4601 dnsip2 - IP address of your secondary Domain Name Server
4602 gatewayip - IP address of the Gateway (Router) to use
4603 hostname - Target hostname
4605 netmask - Subnet Mask
4606 rootpath - Pathname of the root filesystem on the NFS server
4607 serverip - see above
4610 There are two special Environment Variables:
4612 serial# - contains hardware identification information such
4613 as type string and/or serial number
4614 ethaddr - Ethernet address
4616 These variables can be set only once (usually during manufacturing of
4617 the board). U-Boot refuses to delete or overwrite these variables
4618 once they have been set once.
4621 Further special Environment Variables:
4623 ver - Contains the U-Boot version string as printed
4624 with the "version" command. This variable is
4625 readonly (see CONFIG_VERSION_VARIABLE).
4628 Please note that changes to some configuration parameters may take
4629 only effect after the next boot (yes, that's just like Windoze :-).
4632 Callback functions for environment variables:
4633 ---------------------------------------------
4635 For some environment variables, the behavior of u-boot needs to change
4636 when their values are changed. This functionailty allows functions to
4637 be associated with arbitrary variables. On creation, overwrite, or
4638 deletion, the callback will provide the opportunity for some side
4639 effect to happen or for the change to be rejected.
4641 The callbacks are named and associated with a function using the
4642 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4644 These callbacks are associated with variables in one of two ways. The
4645 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4646 in the board configuration to a string that defines a list of
4647 associations. The list must be in the following format:
4649 entry = variable_name[:callback_name]
4652 If the callback name is not specified, then the callback is deleted.
4653 Spaces are also allowed anywhere in the list.
4655 Callbacks can also be associated by defining the ".callbacks" variable
4656 with the same list format above. Any association in ".callbacks" will
4657 override any association in the static list. You can define
4658 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4659 ".callbacks" envirnoment variable in the default or embedded environment.
4662 Command Line Parsing:
4663 =====================
4665 There are two different command line parsers available with U-Boot:
4666 the old "simple" one, and the much more powerful "hush" shell:
4668 Old, simple command line parser:
4669 --------------------------------
4671 - supports environment variables (through setenv / saveenv commands)
4672 - several commands on one line, separated by ';'
4673 - variable substitution using "... ${name} ..." syntax
4674 - special characters ('$', ';') can be escaped by prefixing with '\',
4676 setenv bootcmd bootm \${address}
4677 - You can also escape text by enclosing in single apostrophes, for example:
4678 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4683 - similar to Bourne shell, with control structures like
4684 if...then...else...fi, for...do...done; while...do...done,
4685 until...do...done, ...
4686 - supports environment ("global") variables (through setenv / saveenv
4687 commands) and local shell variables (through standard shell syntax
4688 "name=value"); only environment variables can be used with "run"
4694 (1) If a command line (or an environment variable executed by a "run"
4695 command) contains several commands separated by semicolon, and
4696 one of these commands fails, then the remaining commands will be
4699 (2) If you execute several variables with one call to run (i. e.
4700 calling run with a list of variables as arguments), any failing
4701 command will cause "run" to terminate, i. e. the remaining
4702 variables are not executed.
4704 Note for Redundant Ethernet Interfaces:
4705 =======================================
4707 Some boards come with redundant Ethernet interfaces; U-Boot supports
4708 such configurations and is capable of automatic selection of a
4709 "working" interface when needed. MAC assignment works as follows:
4711 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4712 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4713 "eth1addr" (=>eth1), "eth2addr", ...
4715 If the network interface stores some valid MAC address (for instance
4716 in SROM), this is used as default address if there is NO correspon-
4717 ding setting in the environment; if the corresponding environment
4718 variable is set, this overrides the settings in the card; that means:
4720 o If the SROM has a valid MAC address, and there is no address in the
4721 environment, the SROM's address is used.
4723 o If there is no valid address in the SROM, and a definition in the
4724 environment exists, then the value from the environment variable is
4727 o If both the SROM and the environment contain a MAC address, and
4728 both addresses are the same, this MAC address is used.
4730 o If both the SROM and the environment contain a MAC address, and the
4731 addresses differ, the value from the environment is used and a
4734 o If neither SROM nor the environment contain a MAC address, an error
4737 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4738 will be programmed into hardware as part of the initialization process. This
4739 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4740 The naming convention is as follows:
4741 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4746 U-Boot is capable of booting (and performing other auxiliary operations on)
4747 images in two formats:
4749 New uImage format (FIT)
4750 -----------------------
4752 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4753 to Flattened Device Tree). It allows the use of images with multiple
4754 components (several kernels, ramdisks, etc.), with contents protected by
4755 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4761 Old image format is based on binary files which can be basically anything,
4762 preceded by a special header; see the definitions in include/image.h for
4763 details; basically, the header defines the following image properties:
4765 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4766 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4767 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4768 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4770 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4771 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4772 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4773 * Compression Type (uncompressed, gzip, bzip2)
4779 The header is marked by a special Magic Number, and both the header
4780 and the data portions of the image are secured against corruption by
4787 Although U-Boot should support any OS or standalone application
4788 easily, the main focus has always been on Linux during the design of
4791 U-Boot includes many features that so far have been part of some
4792 special "boot loader" code within the Linux kernel. Also, any
4793 "initrd" images to be used are no longer part of one big Linux image;
4794 instead, kernel and "initrd" are separate images. This implementation
4795 serves several purposes:
4797 - the same features can be used for other OS or standalone
4798 applications (for instance: using compressed images to reduce the
4799 Flash memory footprint)
4801 - it becomes much easier to port new Linux kernel versions because
4802 lots of low-level, hardware dependent stuff are done by U-Boot
4804 - the same Linux kernel image can now be used with different "initrd"
4805 images; of course this also means that different kernel images can
4806 be run with the same "initrd". This makes testing easier (you don't
4807 have to build a new "zImage.initrd" Linux image when you just
4808 change a file in your "initrd"). Also, a field-upgrade of the
4809 software is easier now.
4815 Porting Linux to U-Boot based systems:
4816 ---------------------------------------
4818 U-Boot cannot save you from doing all the necessary modifications to
4819 configure the Linux device drivers for use with your target hardware
4820 (no, we don't intend to provide a full virtual machine interface to
4823 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4825 Just make sure your machine specific header file (for instance
4826 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4827 Information structure as we define in include/asm-<arch>/u-boot.h,
4828 and make sure that your definition of IMAP_ADDR uses the same value
4829 as your U-Boot configuration in CONFIG_SYS_IMMR.
4832 Configuring the Linux kernel:
4833 -----------------------------
4835 No specific requirements for U-Boot. Make sure you have some root
4836 device (initial ramdisk, NFS) for your target system.
4839 Building a Linux Image:
4840 -----------------------
4842 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4843 not used. If you use recent kernel source, a new build target
4844 "uImage" will exist which automatically builds an image usable by
4845 U-Boot. Most older kernels also have support for a "pImage" target,
4846 which was introduced for our predecessor project PPCBoot and uses a
4847 100% compatible format.
4856 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4857 encapsulate a compressed Linux kernel image with header information,
4858 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4860 * build a standard "vmlinux" kernel image (in ELF binary format):
4862 * convert the kernel into a raw binary image:
4864 ${CROSS_COMPILE}-objcopy -O binary \
4865 -R .note -R .comment \
4866 -S vmlinux linux.bin
4868 * compress the binary image:
4872 * package compressed binary image for U-Boot:
4874 mkimage -A ppc -O linux -T kernel -C gzip \
4875 -a 0 -e 0 -n "Linux Kernel Image" \
4876 -d linux.bin.gz uImage
4879 The "mkimage" tool can also be used to create ramdisk images for use
4880 with U-Boot, either separated from the Linux kernel image, or
4881 combined into one file. "mkimage" encapsulates the images with a 64
4882 byte header containing information about target architecture,
4883 operating system, image type, compression method, entry points, time
4884 stamp, CRC32 checksums, etc.
4886 "mkimage" can be called in two ways: to verify existing images and
4887 print the header information, or to build new images.
4889 In the first form (with "-l" option) mkimage lists the information
4890 contained in the header of an existing U-Boot image; this includes
4891 checksum verification:
4893 tools/mkimage -l image
4894 -l ==> list image header information
4896 The second form (with "-d" option) is used to build a U-Boot image
4897 from a "data file" which is used as image payload:
4899 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4900 -n name -d data_file image
4901 -A ==> set architecture to 'arch'
4902 -O ==> set operating system to 'os'
4903 -T ==> set image type to 'type'
4904 -C ==> set compression type 'comp'
4905 -a ==> set load address to 'addr' (hex)
4906 -e ==> set entry point to 'ep' (hex)
4907 -n ==> set image name to 'name'
4908 -d ==> use image data from 'datafile'
4910 Right now, all Linux kernels for PowerPC systems use the same load
4911 address (0x00000000), but the entry point address depends on the
4914 - 2.2.x kernels have the entry point at 0x0000000C,
4915 - 2.3.x and later kernels have the entry point at 0x00000000.
4917 So a typical call to build a U-Boot image would read:
4919 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4920 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4921 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4922 > examples/uImage.TQM850L
4923 Image Name: 2.4.4 kernel for TQM850L
4924 Created: Wed Jul 19 02:34:59 2000
4925 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4926 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4927 Load Address: 0x00000000
4928 Entry Point: 0x00000000
4930 To verify the contents of the image (or check for corruption):
4932 -> tools/mkimage -l examples/uImage.TQM850L
4933 Image Name: 2.4.4 kernel for TQM850L
4934 Created: Wed Jul 19 02:34:59 2000
4935 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4936 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4937 Load Address: 0x00000000
4938 Entry Point: 0x00000000
4940 NOTE: for embedded systems where boot time is critical you can trade
4941 speed for memory and install an UNCOMPRESSED image instead: this
4942 needs more space in Flash, but boots much faster since it does not
4943 need to be uncompressed:
4945 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4946 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4947 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4948 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4949 > examples/uImage.TQM850L-uncompressed
4950 Image Name: 2.4.4 kernel for TQM850L
4951 Created: Wed Jul 19 02:34:59 2000
4952 Image Type: PowerPC Linux Kernel Image (uncompressed)
4953 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4954 Load Address: 0x00000000
4955 Entry Point: 0x00000000
4958 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4959 when your kernel is intended to use an initial ramdisk:
4961 -> tools/mkimage -n 'Simple Ramdisk Image' \
4962 > -A ppc -O linux -T ramdisk -C gzip \
4963 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4964 Image Name: Simple Ramdisk Image
4965 Created: Wed Jan 12 14:01:50 2000
4966 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4967 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4968 Load Address: 0x00000000
4969 Entry Point: 0x00000000
4972 Installing a Linux Image:
4973 -------------------------
4975 To downloading a U-Boot image over the serial (console) interface,
4976 you must convert the image to S-Record format:
4978 objcopy -I binary -O srec examples/image examples/image.srec
4980 The 'objcopy' does not understand the information in the U-Boot
4981 image header, so the resulting S-Record file will be relative to
4982 address 0x00000000. To load it to a given address, you need to
4983 specify the target address as 'offset' parameter with the 'loads'
4986 Example: install the image to address 0x40100000 (which on the
4987 TQM8xxL is in the first Flash bank):
4989 => erase 40100000 401FFFFF
4995 ## Ready for S-Record download ...
4996 ~>examples/image.srec
4997 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4999 15989 15990 15991 15992
5000 [file transfer complete]
5002 ## Start Addr = 0x00000000
5005 You can check the success of the download using the 'iminfo' command;
5006 this includes a checksum verification so you can be sure no data
5007 corruption happened:
5011 ## Checking Image at 40100000 ...
5012 Image Name: 2.2.13 for initrd on TQM850L
5013 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5014 Data Size: 335725 Bytes = 327 kB = 0 MB
5015 Load Address: 00000000
5016 Entry Point: 0000000c
5017 Verifying Checksum ... OK
5023 The "bootm" command is used to boot an application that is stored in
5024 memory (RAM or Flash). In case of a Linux kernel image, the contents
5025 of the "bootargs" environment variable is passed to the kernel as
5026 parameters. You can check and modify this variable using the
5027 "printenv" and "setenv" commands:
5030 => printenv bootargs
5031 bootargs=root=/dev/ram
5033 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5035 => printenv bootargs
5036 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5039 ## Booting Linux kernel at 40020000 ...
5040 Image Name: 2.2.13 for NFS on TQM850L
5041 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5042 Data Size: 381681 Bytes = 372 kB = 0 MB
5043 Load Address: 00000000
5044 Entry Point: 0000000c
5045 Verifying Checksum ... OK
5046 Uncompressing Kernel Image ... OK
5047 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
5048 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5049 time_init: decrementer frequency = 187500000/60
5050 Calibrating delay loop... 49.77 BogoMIPS
5051 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5054 If you want to boot a Linux kernel with initial RAM disk, you pass
5055 the memory addresses of both the kernel and the initrd image (PPBCOOT
5056 format!) to the "bootm" command:
5058 => imi 40100000 40200000
5060 ## Checking Image at 40100000 ...
5061 Image Name: 2.2.13 for initrd on TQM850L
5062 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5063 Data Size: 335725 Bytes = 327 kB = 0 MB
5064 Load Address: 00000000
5065 Entry Point: 0000000c
5066 Verifying Checksum ... OK
5068 ## Checking Image at 40200000 ...
5069 Image Name: Simple Ramdisk Image
5070 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5071 Data Size: 566530 Bytes = 553 kB = 0 MB
5072 Load Address: 00000000
5073 Entry Point: 00000000
5074 Verifying Checksum ... OK
5076 => bootm 40100000 40200000
5077 ## Booting Linux kernel at 40100000 ...
5078 Image Name: 2.2.13 for initrd on TQM850L
5079 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5080 Data Size: 335725 Bytes = 327 kB = 0 MB
5081 Load Address: 00000000
5082 Entry Point: 0000000c
5083 Verifying Checksum ... OK
5084 Uncompressing Kernel Image ... OK
5085 ## Loading RAMDisk Image at 40200000 ...
5086 Image Name: Simple Ramdisk Image
5087 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5088 Data Size: 566530 Bytes = 553 kB = 0 MB
5089 Load Address: 00000000
5090 Entry Point: 00000000
5091 Verifying Checksum ... OK
5092 Loading Ramdisk ... OK
5093 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
5094 Boot arguments: root=/dev/ram
5095 time_init: decrementer frequency = 187500000/60
5096 Calibrating delay loop... 49.77 BogoMIPS
5098 RAMDISK: Compressed image found at block 0
5099 VFS: Mounted root (ext2 filesystem).
5103 Boot Linux and pass a flat device tree:
5106 First, U-Boot must be compiled with the appropriate defines. See the section
5107 titled "Linux Kernel Interface" above for a more in depth explanation. The
5108 following is an example of how to start a kernel and pass an updated
5114 oft=oftrees/mpc8540ads.dtb
5115 => tftp $oftaddr $oft
5116 Speed: 1000, full duplex
5118 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5119 Filename 'oftrees/mpc8540ads.dtb'.
5120 Load address: 0x300000
5123 Bytes transferred = 4106 (100a hex)
5124 => tftp $loadaddr $bootfile
5125 Speed: 1000, full duplex
5127 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5129 Load address: 0x200000
5130 Loading:############
5132 Bytes transferred = 1029407 (fb51f hex)
5137 => bootm $loadaddr - $oftaddr
5138 ## Booting image at 00200000 ...
5139 Image Name: Linux-2.6.17-dirty
5140 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5141 Data Size: 1029343 Bytes = 1005.2 kB
5142 Load Address: 00000000
5143 Entry Point: 00000000
5144 Verifying Checksum ... OK
5145 Uncompressing Kernel Image ... OK
5146 Booting using flat device tree at 0x300000
5147 Using MPC85xx ADS machine description
5148 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5152 More About U-Boot Image Types:
5153 ------------------------------
5155 U-Boot supports the following image types:
5157 "Standalone Programs" are directly runnable in the environment
5158 provided by U-Boot; it is expected that (if they behave
5159 well) you can continue to work in U-Boot after return from
5160 the Standalone Program.
5161 "OS Kernel Images" are usually images of some Embedded OS which
5162 will take over control completely. Usually these programs
5163 will install their own set of exception handlers, device
5164 drivers, set up the MMU, etc. - this means, that you cannot
5165 expect to re-enter U-Boot except by resetting the CPU.
5166 "RAMDisk Images" are more or less just data blocks, and their
5167 parameters (address, size) are passed to an OS kernel that is
5169 "Multi-File Images" contain several images, typically an OS
5170 (Linux) kernel image and one or more data images like
5171 RAMDisks. This construct is useful for instance when you want
5172 to boot over the network using BOOTP etc., where the boot
5173 server provides just a single image file, but you want to get
5174 for instance an OS kernel and a RAMDisk image.
5176 "Multi-File Images" start with a list of image sizes, each
5177 image size (in bytes) specified by an "uint32_t" in network
5178 byte order. This list is terminated by an "(uint32_t)0".
5179 Immediately after the terminating 0 follow the images, one by
5180 one, all aligned on "uint32_t" boundaries (size rounded up to
5181 a multiple of 4 bytes).
5183 "Firmware Images" are binary images containing firmware (like
5184 U-Boot or FPGA images) which usually will be programmed to
5187 "Script files" are command sequences that will be executed by
5188 U-Boot's command interpreter; this feature is especially
5189 useful when you configure U-Boot to use a real shell (hush)
5190 as command interpreter.
5192 Booting the Linux zImage:
5193 -------------------------
5195 On some platforms, it's possible to boot Linux zImage. This is done
5196 using the "bootz" command. The syntax of "bootz" command is the same
5197 as the syntax of "bootm" command.
5199 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5200 kernel with raw initrd images. The syntax is slightly different, the
5201 address of the initrd must be augmented by it's size, in the following
5202 format: "<initrd addres>:<initrd size>".
5208 One of the features of U-Boot is that you can dynamically load and
5209 run "standalone" applications, which can use some resources of
5210 U-Boot like console I/O functions or interrupt services.
5212 Two simple examples are included with the sources:
5217 'examples/hello_world.c' contains a small "Hello World" Demo
5218 application; it is automatically compiled when you build U-Boot.
5219 It's configured to run at address 0x00040004, so you can play with it
5223 ## Ready for S-Record download ...
5224 ~>examples/hello_world.srec
5225 1 2 3 4 5 6 7 8 9 10 11 ...
5226 [file transfer complete]
5228 ## Start Addr = 0x00040004
5230 => go 40004 Hello World! This is a test.
5231 ## Starting application at 0x00040004 ...
5242 Hit any key to exit ...
5244 ## Application terminated, rc = 0x0
5246 Another example, which demonstrates how to register a CPM interrupt
5247 handler with the U-Boot code, can be found in 'examples/timer.c'.
5248 Here, a CPM timer is set up to generate an interrupt every second.
5249 The interrupt service routine is trivial, just printing a '.'
5250 character, but this is just a demo program. The application can be
5251 controlled by the following keys:
5253 ? - print current values og the CPM Timer registers
5254 b - enable interrupts and start timer
5255 e - stop timer and disable interrupts
5256 q - quit application
5259 ## Ready for S-Record download ...
5260 ~>examples/timer.srec
5261 1 2 3 4 5 6 7 8 9 10 11 ...
5262 [file transfer complete]
5264 ## Start Addr = 0x00040004
5267 ## Starting application at 0x00040004 ...
5270 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5273 [q, b, e, ?] Set interval 1000000 us
5276 [q, b, e, ?] ........
5277 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5280 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5283 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5286 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5288 [q, b, e, ?] ...Stopping timer
5290 [q, b, e, ?] ## Application terminated, rc = 0x0
5296 Over time, many people have reported problems when trying to use the
5297 "minicom" terminal emulation program for serial download. I (wd)
5298 consider minicom to be broken, and recommend not to use it. Under
5299 Unix, I recommend to use C-Kermit for general purpose use (and
5300 especially for kermit binary protocol download ("loadb" command), and
5301 use "cu" for S-Record download ("loads" command). See
5302 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5303 for help with kermit.
5306 Nevertheless, if you absolutely want to use it try adding this
5307 configuration to your "File transfer protocols" section:
5309 Name Program Name U/D FullScr IO-Red. Multi
5310 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5311 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5317 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5318 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5320 Building requires a cross environment; it is known to work on
5321 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5322 need gmake since the Makefiles are not compatible with BSD make).
5323 Note that the cross-powerpc package does not install include files;
5324 attempting to build U-Boot will fail because <machine/ansi.h> is
5325 missing. This file has to be installed and patched manually:
5327 # cd /usr/pkg/cross/powerpc-netbsd/include
5329 # ln -s powerpc machine
5330 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5331 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5333 Native builds *don't* work due to incompatibilities between native
5334 and U-Boot include files.
5336 Booting assumes that (the first part of) the image booted is a
5337 stage-2 loader which in turn loads and then invokes the kernel
5338 proper. Loader sources will eventually appear in the NetBSD source
5339 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5340 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5343 Implementation Internals:
5344 =========================
5346 The following is not intended to be a complete description of every
5347 implementation detail. However, it should help to understand the
5348 inner workings of U-Boot and make it easier to port it to custom
5352 Initial Stack, Global Data:
5353 ---------------------------
5355 The implementation of U-Boot is complicated by the fact that U-Boot
5356 starts running out of ROM (flash memory), usually without access to
5357 system RAM (because the memory controller is not initialized yet).
5358 This means that we don't have writable Data or BSS segments, and BSS
5359 is not initialized as zero. To be able to get a C environment working
5360 at all, we have to allocate at least a minimal stack. Implementation
5361 options for this are defined and restricted by the CPU used: Some CPU
5362 models provide on-chip memory (like the IMMR area on MPC8xx and
5363 MPC826x processors), on others (parts of) the data cache can be
5364 locked as (mis-) used as memory, etc.
5366 Chris Hallinan posted a good summary of these issues to the
5367 U-Boot mailing list:
5369 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5370 From: "Chris Hallinan" <clh@net1plus.com>
5371 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5374 Correct me if I'm wrong, folks, but the way I understand it
5375 is this: Using DCACHE as initial RAM for Stack, etc, does not
5376 require any physical RAM backing up the cache. The cleverness
5377 is that the cache is being used as a temporary supply of
5378 necessary storage before the SDRAM controller is setup. It's
5379 beyond the scope of this list to explain the details, but you
5380 can see how this works by studying the cache architecture and
5381 operation in the architecture and processor-specific manuals.
5383 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5384 is another option for the system designer to use as an
5385 initial stack/RAM area prior to SDRAM being available. Either
5386 option should work for you. Using CS 4 should be fine if your
5387 board designers haven't used it for something that would
5388 cause you grief during the initial boot! It is frequently not
5391 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5392 with your processor/board/system design. The default value
5393 you will find in any recent u-boot distribution in
5394 walnut.h should work for you. I'd set it to a value larger
5395 than your SDRAM module. If you have a 64MB SDRAM module, set
5396 it above 400_0000. Just make sure your board has no resources
5397 that are supposed to respond to that address! That code in
5398 start.S has been around a while and should work as is when
5399 you get the config right.
5404 It is essential to remember this, since it has some impact on the C
5405 code for the initialization procedures:
5407 * Initialized global data (data segment) is read-only. Do not attempt
5410 * Do not use any uninitialized global data (or implicitely initialized
5411 as zero data - BSS segment) at all - this is undefined, initiali-
5412 zation is performed later (when relocating to RAM).
5414 * Stack space is very limited. Avoid big data buffers or things like
5417 Having only the stack as writable memory limits means we cannot use
5418 normal global data to share information beween the code. But it
5419 turned out that the implementation of U-Boot can be greatly
5420 simplified by making a global data structure (gd_t) available to all
5421 functions. We could pass a pointer to this data as argument to _all_
5422 functions, but this would bloat the code. Instead we use a feature of
5423 the GCC compiler (Global Register Variables) to share the data: we
5424 place a pointer (gd) to the global data into a register which we
5425 reserve for this purpose.
5427 When choosing a register for such a purpose we are restricted by the
5428 relevant (E)ABI specifications for the current architecture, and by
5429 GCC's implementation.
5431 For PowerPC, the following registers have specific use:
5433 R2: reserved for system use
5434 R3-R4: parameter passing and return values
5435 R5-R10: parameter passing
5436 R13: small data area pointer
5440 (U-Boot also uses R12 as internal GOT pointer. r12
5441 is a volatile register so r12 needs to be reset when
5442 going back and forth between asm and C)
5444 ==> U-Boot will use R2 to hold a pointer to the global data
5446 Note: on PPC, we could use a static initializer (since the
5447 address of the global data structure is known at compile time),
5448 but it turned out that reserving a register results in somewhat
5449 smaller code - although the code savings are not that big (on
5450 average for all boards 752 bytes for the whole U-Boot image,
5451 624 text + 127 data).
5453 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5454 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5456 ==> U-Boot will use P3 to hold a pointer to the global data
5458 On ARM, the following registers are used:
5460 R0: function argument word/integer result
5461 R1-R3: function argument word
5463 R10: stack limit (used only if stack checking if enabled)
5464 R11: argument (frame) pointer
5465 R12: temporary workspace
5468 R15: program counter
5470 ==> U-Boot will use R8 to hold a pointer to the global data
5472 On Nios II, the ABI is documented here:
5473 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5475 ==> U-Boot will use gp to hold a pointer to the global data
5477 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5478 to access small data sections, so gp is free.
5480 On NDS32, the following registers are used:
5482 R0-R1: argument/return
5484 R15: temporary register for assembler
5485 R16: trampoline register
5486 R28: frame pointer (FP)
5487 R29: global pointer (GP)
5488 R30: link register (LP)
5489 R31: stack pointer (SP)
5490 PC: program counter (PC)
5492 ==> U-Boot will use R10 to hold a pointer to the global data
5494 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5495 or current versions of GCC may "optimize" the code too much.
5500 U-Boot runs in system state and uses physical addresses, i.e. the
5501 MMU is not used either for address mapping nor for memory protection.
5503 The available memory is mapped to fixed addresses using the memory
5504 controller. In this process, a contiguous block is formed for each
5505 memory type (Flash, SDRAM, SRAM), even when it consists of several
5506 physical memory banks.
5508 U-Boot is installed in the first 128 kB of the first Flash bank (on
5509 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5510 booting and sizing and initializing DRAM, the code relocates itself
5511 to the upper end of DRAM. Immediately below the U-Boot code some
5512 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5513 configuration setting]. Below that, a structure with global Board
5514 Info data is placed, followed by the stack (growing downward).
5516 Additionally, some exception handler code is copied to the low 8 kB
5517 of DRAM (0x00000000 ... 0x00001FFF).
5519 So a typical memory configuration with 16 MB of DRAM could look like
5522 0x0000 0000 Exception Vector code
5525 0x0000 2000 Free for Application Use
5531 0x00FB FF20 Monitor Stack (Growing downward)
5532 0x00FB FFAC Board Info Data and permanent copy of global data
5533 0x00FC 0000 Malloc Arena
5536 0x00FE 0000 RAM Copy of Monitor Code
5537 ... eventually: LCD or video framebuffer
5538 ... eventually: pRAM (Protected RAM - unchanged by reset)
5539 0x00FF FFFF [End of RAM]
5542 System Initialization:
5543 ----------------------
5545 In the reset configuration, U-Boot starts at the reset entry point
5546 (on most PowerPC systems at address 0x00000100). Because of the reset
5547 configuration for CS0# this is a mirror of the onboard Flash memory.
5548 To be able to re-map memory U-Boot then jumps to its link address.
5549 To be able to implement the initialization code in C, a (small!)
5550 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5551 which provide such a feature like MPC8xx or MPC8260), or in a locked
5552 part of the data cache. After that, U-Boot initializes the CPU core,
5553 the caches and the SIU.
5555 Next, all (potentially) available memory banks are mapped using a
5556 preliminary mapping. For example, we put them on 512 MB boundaries
5557 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5558 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5559 programmed for SDRAM access. Using the temporary configuration, a
5560 simple memory test is run that determines the size of the SDRAM
5563 When there is more than one SDRAM bank, and the banks are of
5564 different size, the largest is mapped first. For equal size, the first
5565 bank (CS2#) is mapped first. The first mapping is always for address
5566 0x00000000, with any additional banks following immediately to create
5567 contiguous memory starting from 0.
5569 Then, the monitor installs itself at the upper end of the SDRAM area
5570 and allocates memory for use by malloc() and for the global Board
5571 Info data; also, the exception vector code is copied to the low RAM
5572 pages, and the final stack is set up.
5574 Only after this relocation will you have a "normal" C environment;
5575 until that you are restricted in several ways, mostly because you are
5576 running from ROM, and because the code will have to be relocated to a
5580 U-Boot Porting Guide:
5581 ----------------------
5583 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5587 int main(int argc, char *argv[])
5589 sighandler_t no_more_time;
5591 signal(SIGALRM, no_more_time);
5592 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5594 if (available_money > available_manpower) {
5595 Pay consultant to port U-Boot;
5599 Download latest U-Boot source;
5601 Subscribe to u-boot mailing list;
5604 email("Hi, I am new to U-Boot, how do I get started?");
5607 Read the README file in the top level directory;
5608 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5609 Read applicable doc/*.README;
5610 Read the source, Luke;
5611 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5614 if (available_money > toLocalCurrency ($2500))
5617 Add a lot of aggravation and time;
5619 if (a similar board exists) { /* hopefully... */
5620 cp -a board/<similar> board/<myboard>
5621 cp include/configs/<similar>.h include/configs/<myboard>.h
5623 Create your own board support subdirectory;
5624 Create your own board include/configs/<myboard>.h file;
5626 Edit new board/<myboard> files
5627 Edit new include/configs/<myboard>.h
5632 Add / modify source code;
5636 email("Hi, I am having problems...");
5638 Send patch file to the U-Boot email list;
5639 if (reasonable critiques)
5640 Incorporate improvements from email list code review;
5642 Defend code as written;
5648 void no_more_time (int sig)
5657 All contributions to U-Boot should conform to the Linux kernel
5658 coding style; see the file "Documentation/CodingStyle" and the script
5659 "scripts/Lindent" in your Linux kernel source directory.
5661 Source files originating from a different project (for example the
5662 MTD subsystem) are generally exempt from these guidelines and are not
5663 reformated to ease subsequent migration to newer versions of those
5666 Please note that U-Boot is implemented in C (and to some small parts in
5667 Assembler); no C++ is used, so please do not use C++ style comments (//)
5670 Please also stick to the following formatting rules:
5671 - remove any trailing white space
5672 - use TAB characters for indentation and vertical alignment, not spaces
5673 - make sure NOT to use DOS '\r\n' line feeds
5674 - do not add more than 2 consecutive empty lines to source files
5675 - do not add trailing empty lines to source files
5677 Submissions which do not conform to the standards may be returned
5678 with a request to reformat the changes.
5684 Since the number of patches for U-Boot is growing, we need to
5685 establish some rules. Submissions which do not conform to these rules
5686 may be rejected, even when they contain important and valuable stuff.
5688 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5690 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5691 see http://lists.denx.de/mailman/listinfo/u-boot
5693 When you send a patch, please include the following information with
5696 * For bug fixes: a description of the bug and how your patch fixes
5697 this bug. Please try to include a way of demonstrating that the
5698 patch actually fixes something.
5700 * For new features: a description of the feature and your
5703 * A CHANGELOG entry as plaintext (separate from the patch)
5705 * For major contributions, your entry to the CREDITS file
5707 * When you add support for a new board, don't forget to add this
5708 board to the MAINTAINERS file, too.
5710 * If your patch adds new configuration options, don't forget to
5711 document these in the README file.
5713 * The patch itself. If you are using git (which is *strongly*
5714 recommended) you can easily generate the patch using the
5715 "git format-patch". If you then use "git send-email" to send it to
5716 the U-Boot mailing list, you will avoid most of the common problems
5717 with some other mail clients.
5719 If you cannot use git, use "diff -purN OLD NEW". If your version of
5720 diff does not support these options, then get the latest version of
5723 The current directory when running this command shall be the parent
5724 directory of the U-Boot source tree (i. e. please make sure that
5725 your patch includes sufficient directory information for the
5728 We prefer patches as plain text. MIME attachments are discouraged,
5729 and compressed attachments must not be used.
5731 * If one logical set of modifications affects or creates several
5732 files, all these changes shall be submitted in a SINGLE patch file.
5734 * Changesets that contain different, unrelated modifications shall be
5735 submitted as SEPARATE patches, one patch per changeset.
5740 * Before sending the patch, run the MAKEALL script on your patched
5741 source tree and make sure that no errors or warnings are reported
5742 for any of the boards.
5744 * Keep your modifications to the necessary minimum: A patch
5745 containing several unrelated changes or arbitrary reformats will be
5746 returned with a request to re-formatting / split it.
5748 * If you modify existing code, make sure that your new code does not
5749 add to the memory footprint of the code ;-) Small is beautiful!
5750 When adding new features, these should compile conditionally only
5751 (using #ifdef), and the resulting code with the new feature
5752 disabled must not need more memory than the old code without your
5755 * Remember that there is a size limit of 100 kB per message on the
5756 u-boot mailing list. Bigger patches will be moderated. If they are
5757 reasonable and not too big, they will be acknowledged. But patches
5758 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob