2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The MAINTAINERS file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm925t Files specific to ARM 925 CPUs
143 /arm926ejs Files specific to ARM 926 CPUs
144 /arm1136 Files specific to ARM 1136 CPUs
145 /ixp Files specific to Intel XScale IXP CPUs
146 /pxa Files specific to Intel XScale PXA CPUs
147 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
148 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
149 /lib Architecture specific library files
150 /avr32 Files generic to AVR32 architecture
151 /cpu CPU specific files
152 /lib Architecture specific library files
153 /blackfin Files generic to Analog Devices Blackfin architecture
154 /cpu CPU specific files
155 /lib Architecture specific library files
156 /x86 Files generic to x86 architecture
157 /cpu CPU specific files
158 /lib Architecture specific library files
159 /m68k Files generic to m68k architecture
160 /cpu CPU specific files
161 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
162 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
163 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
164 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
165 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
166 /lib Architecture specific library files
167 /microblaze Files generic to microblaze architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /mips Files generic to MIPS architecture
171 /cpu CPU specific files
172 /mips32 Files specific to MIPS32 CPUs
173 /xburst Files specific to Ingenic XBurst CPUs
174 /lib Architecture specific library files
175 /nds32 Files generic to NDS32 architecture
176 /cpu CPU specific files
177 /n1213 Files specific to Andes Technology N1213 CPUs
178 /lib Architecture specific library files
179 /nios2 Files generic to Altera NIOS2 architecture
180 /cpu CPU specific files
181 /lib Architecture specific library files
182 /powerpc Files generic to PowerPC architecture
183 /cpu CPU specific files
184 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc824x Files specific to Freescale MPC824x CPUs
189 /mpc8260 Files specific to Freescale MPC8260 CPUs
190 /mpc85xx Files specific to Freescale MPC85xx CPUs
191 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
192 /lib Architecture specific library files
193 /sh Files generic to SH architecture
194 /cpu CPU specific files
195 /sh2 Files specific to sh2 CPUs
196 /sh3 Files specific to sh3 CPUs
197 /sh4 Files specific to sh4 CPUs
198 /lib Architecture specific library files
199 /sparc Files generic to SPARC architecture
200 /cpu CPU specific files
201 /leon2 Files specific to Gaisler LEON2 SPARC CPU
202 /leon3 Files specific to Gaisler LEON3 SPARC CPU
203 /lib Architecture specific library files
204 /api Machine/arch independent API for external apps
205 /board Board dependent files
206 /common Misc architecture independent functions
207 /disk Code for disk drive partition handling
208 /doc Documentation (don't expect too much)
209 /drivers Commonly used device drivers
210 /examples Example code for standalone applications, etc.
211 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
212 /include Header Files
213 /lib Files generic to all architectures
214 /libfdt Library files to support flattened device trees
215 /lzma Library files to support LZMA decompression
216 /lzo Library files to support LZO decompression
218 /post Power On Self Test
219 /rtc Real Time Clock drivers
220 /tools Tools to build S-Record or U-Boot images, etc.
222 Software Configuration:
223 =======================
225 Configuration is usually done using C preprocessor defines; the
226 rationale behind that is to avoid dead code whenever possible.
228 There are two classes of configuration variables:
230 * Configuration _OPTIONS_:
231 These are selectable by the user and have names beginning with
234 * Configuration _SETTINGS_:
235 These depend on the hardware etc. and should not be meddled with if
236 you don't know what you're doing; they have names beginning with
239 Later we will add a configuration tool - probably similar to or even
240 identical to what's used for the Linux kernel. Right now, we have to
241 do the configuration by hand, which means creating some symbolic
242 links and editing some configuration files. We use the TQM8xxL boards
246 Selection of Processor Architecture and Board Type:
247 ---------------------------------------------------
249 For all supported boards there are ready-to-use default
250 configurations available; just type "make <board_name>_config".
252 Example: For a TQM823L module type:
257 For the Cogent platform, you need to specify the CPU type as well;
258 e.g. "make cogent_mpc8xx_config". And also configure the cogent
259 directory according to the instructions in cogent/README.
262 Configuration Options:
263 ----------------------
265 Configuration depends on the combination of board and CPU type; all
266 such information is kept in a configuration file
267 "include/configs/<board_name>.h".
269 Example: For a TQM823L module, all configuration settings are in
270 "include/configs/TQM823L.h".
273 Many of the options are named exactly as the corresponding Linux
274 kernel configuration options. The intention is to make it easier to
275 build a config tool - later.
278 The following options need to be configured:
280 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
282 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
284 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
285 Define exactly one, e.g. CONFIG_ATSTK1002
287 - CPU Module Type: (if CONFIG_COGENT is defined)
288 Define exactly one of
290 --- FIXME --- not tested yet:
291 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
292 CONFIG_CMA287_23, CONFIG_CMA287_50
294 - Motherboard Type: (if CONFIG_COGENT is defined)
295 Define exactly one of
296 CONFIG_CMA101, CONFIG_CMA102
298 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
299 Define one or more of
302 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
303 Define one or more of
304 CONFIG_LCD_HEARTBEAT - update a character position on
305 the LCD display every second with
308 - Board flavour: (if CONFIG_MPC8260ADS is defined)
311 CONFIG_SYS_8260ADS - original MPC8260ADS
312 CONFIG_SYS_8266ADS - MPC8266ADS
313 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
314 CONFIG_SYS_8272ADS - MPC8272ADS
316 - Marvell Family Member
317 CONFIG_SYS_MVFS - define it if you want to enable
318 multiple fs option at one time
319 for marvell soc family
321 - MPC824X Family Member (if CONFIG_MPC824X is defined)
322 Define exactly one of
323 CONFIG_MPC8240, CONFIG_MPC8245
325 - 8xx CPU Options: (if using an MPC8xx CPU)
326 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
327 get_gclk_freq() cannot work
328 e.g. if there is no 32KHz
329 reference PIT/RTC clock
330 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
333 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
334 CONFIG_SYS_8xx_CPUCLK_MIN
335 CONFIG_SYS_8xx_CPUCLK_MAX
336 CONFIG_8xx_CPUCLK_DEFAULT
337 See doc/README.MPC866
339 CONFIG_SYS_MEASURE_CPUCLK
341 Define this to measure the actual CPU clock instead
342 of relying on the correctness of the configured
343 values. Mostly useful for board bringup to make sure
344 the PLL is locked at the intended frequency. Note
345 that this requires a (stable) reference clock (32 kHz
346 RTC clock or CONFIG_SYS_8XX_XIN)
348 CONFIG_SYS_DELAYED_ICACHE
350 Define this option if you want to enable the
351 ICache only when Code runs from RAM.
356 Specifies that the core is a 64-bit PowerPC implementation (implements
357 the "64" category of the Power ISA). This is necessary for ePAPR
358 compliance, among other possible reasons.
360 CONFIG_SYS_FSL_TBCLK_DIV
362 Defines the core time base clock divider ratio compared to the
363 system clock. On most PQ3 devices this is 8, on newer QorIQ
364 devices it can be 16 or 32. The ratio varies from SoC to Soc.
366 CONFIG_SYS_FSL_PCIE_COMPAT
368 Defines the string to utilize when trying to match PCIe device
369 tree nodes for the given platform.
371 CONFIG_SYS_PPC_E500_DEBUG_TLB
373 Enables a temporary TLB entry to be used during boot to work
374 around limitations in e500v1 and e500v2 external debugger
375 support. This reduces the portions of the boot code where
376 breakpoints and single stepping do not work. The value of this
377 symbol should be set to the TLB1 entry to be used for this
380 CONFIG_SYS_FSL_ERRATUM_A004510
382 Enables a workaround for erratum A004510. If set,
383 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
384 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
386 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
389 Defines one or two SoC revisions (low 8 bits of SVR)
390 for which the A004510 workaround should be applied.
392 The rest of SVR is either not relevant to the decision
393 of whether the erratum is present (e.g. p2040 versus
394 p2041) or is implied by the build target, which controls
395 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
397 See Freescale App Note 4493 for more information about
400 CONFIG_A003399_NOR_WORKAROUND
401 Enables a workaround for IFC erratum A003399. It is only
402 requred during NOR boot.
404 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
406 This is the value to write into CCSR offset 0x18600
407 according to the A004510 workaround.
409 CONFIG_SYS_FSL_DSP_DDR_ADDR
410 This value denotes start offset of DDR memory which is
411 connected exclusively to the DSP cores.
413 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
414 This value denotes start offset of M2 memory
415 which is directly connected to the DSP core.
417 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
418 This value denotes start offset of M3 memory which is directly
419 connected to the DSP core.
421 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
422 This value denotes start offset of DSP CCSR space.
424 CONFIG_SYS_FSL_DDR_EMU
425 Specify emulator support for DDR. Some DDR features such as
426 deskew training are not available.
428 - Generic CPU options:
429 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
431 Defines the endianess of the CPU. Implementation of those
432 values is arch specific.
434 - Intel Monahans options:
435 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
437 Defines the Monahans run mode to oscillator
438 ratio. Valid values are 8, 16, 24, 31. The core
439 frequency is this value multiplied by 13 MHz.
441 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
443 Defines the Monahans turbo mode to oscillator
444 ratio. Valid values are 1 (default if undefined) and
445 2. The core frequency as calculated above is multiplied
449 CONFIG_SYS_INIT_SP_OFFSET
451 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
452 pointer. This is needed for the temporary stack before
455 CONFIG_SYS_MIPS_CACHE_MODE
457 Cache operation mode for the MIPS CPU.
458 See also arch/mips/include/asm/mipsregs.h.
460 CONF_CM_CACHABLE_NO_WA
463 CONF_CM_CACHABLE_NONCOHERENT
467 CONF_CM_CACHABLE_ACCELERATED
469 CONFIG_SYS_XWAY_EBU_BOOTCFG
471 Special option for Lantiq XWAY SoCs for booting from NOR flash.
472 See also arch/mips/cpu/mips32/start.S.
474 CONFIG_XWAY_SWAP_BYTES
476 Enable compilation of tools/xway-swap-bytes needed for Lantiq
477 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
478 be swapped if a flash programmer is used.
481 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
483 Select high exception vectors of the ARM core, e.g., do not
484 clear the V bit of the c1 register of CP15.
486 CONFIG_SYS_THUMB_BUILD
488 Use this flag to build U-Boot using the Thumb instruction
489 set for ARM architectures. Thumb instruction set provides
490 better code density. For ARM architectures that support
491 Thumb2 this flag will result in Thumb2 code generated by
494 CONFIG_ARM_ERRATA_716044
495 CONFIG_ARM_ERRATA_742230
496 CONFIG_ARM_ERRATA_743622
497 CONFIG_ARM_ERRATA_751472
499 If set, the workarounds for these ARM errata are applied early
500 during U-Boot startup. Note that these options force the
501 workarounds to be applied; no CPU-type/version detection
502 exists, unlike the similar options in the Linux kernel. Do not
503 set these options unless they apply!
508 The frequency of the timer returned by get_timer().
509 get_timer() must operate in milliseconds and this CONFIG
510 option must be set to 1000.
512 - Linux Kernel Interface:
515 U-Boot stores all clock information in Hz
516 internally. For binary compatibility with older Linux
517 kernels (which expect the clocks passed in the
518 bd_info data to be in MHz) the environment variable
519 "clocks_in_mhz" can be defined so that U-Boot
520 converts clock data to MHZ before passing it to the
522 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
523 "clocks_in_mhz=1" is automatically included in the
526 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
528 When transferring memsize parameter to linux, some versions
529 expect it to be in bytes, others in MB.
530 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
534 New kernel versions are expecting firmware settings to be
535 passed using flattened device trees (based on open firmware
539 * New libfdt-based support
540 * Adds the "fdt" command
541 * The bootm command automatically updates the fdt
543 OF_CPU - The proper name of the cpus node (only required for
544 MPC512X and MPC5xxx based boards).
545 OF_SOC - The proper name of the soc node (only required for
546 MPC512X and MPC5xxx based boards).
547 OF_TBCLK - The timebase frequency.
548 OF_STDOUT_PATH - The path to the console device
550 boards with QUICC Engines require OF_QE to set UCC MAC
553 CONFIG_OF_BOARD_SETUP
555 Board code has addition modification that it wants to make
556 to the flat device tree before handing it off to the kernel
560 This define fills in the correct boot CPU in the boot
561 param header, the default value is zero if undefined.
565 U-Boot can detect if an IDE device is present or not.
566 If not, and this new config option is activated, U-Boot
567 removes the ATA node from the DTS before booting Linux,
568 so the Linux IDE driver does not probe the device and
569 crash. This is needed for buggy hardware (uc101) where
570 no pull down resistor is connected to the signal IDE5V_DD7.
572 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
574 This setting is mandatory for all boards that have only one
575 machine type and must be used to specify the machine type
576 number as it appears in the ARM machine registry
577 (see http://www.arm.linux.org.uk/developer/machines/).
578 Only boards that have multiple machine types supported
579 in a single configuration file and the machine type is
580 runtime discoverable, do not have to use this setting.
582 - vxWorks boot parameters:
584 bootvx constructs a valid bootline using the following
585 environments variables: bootfile, ipaddr, serverip, hostname.
586 It loads the vxWorks image pointed bootfile.
588 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
589 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
590 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
591 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
593 CONFIG_SYS_VXWORKS_ADD_PARAMS
595 Add it at the end of the bootline. E.g "u=username pw=secret"
597 Note: If a "bootargs" environment is defined, it will overwride
598 the defaults discussed just above.
600 - Cache Configuration:
601 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
602 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
603 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
605 - Cache Configuration for ARM:
606 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
608 CONFIG_SYS_PL310_BASE - Physical base address of PL310
609 controller register space
614 Define this if you want support for Amba PrimeCell PL010 UARTs.
618 Define this if you want support for Amba PrimeCell PL011 UARTs.
622 If you have Amba PrimeCell PL011 UARTs, set this variable to
623 the clock speed of the UARTs.
627 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
628 define this to a list of base addresses for each (supported)
629 port. See e.g. include/configs/versatile.h
631 CONFIG_PL011_SERIAL_RLCR
633 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
634 have separate receive and transmit line control registers. Set
635 this variable to initialize the extra register.
637 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
639 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
640 boot loader that has already initialized the UART. Define this
641 variable to flush the UART at init time.
645 Depending on board, define exactly one serial port
646 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
647 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
648 console by defining CONFIG_8xx_CONS_NONE
650 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
651 port routines must be defined elsewhere
652 (i.e. serial_init(), serial_getc(), ...)
655 Enables console device for a color framebuffer. Needs following
656 defines (cf. smiLynxEM, i8042)
657 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
659 VIDEO_HW_RECTFILL graphic chip supports
662 VIDEO_HW_BITBLT graphic chip supports
663 bit-blit (cf. smiLynxEM)
664 VIDEO_VISIBLE_COLS visible pixel columns
666 VIDEO_VISIBLE_ROWS visible pixel rows
667 VIDEO_PIXEL_SIZE bytes per pixel
668 VIDEO_DATA_FORMAT graphic data format
669 (0-5, cf. cfb_console.c)
670 VIDEO_FB_ADRS framebuffer address
671 VIDEO_KBD_INIT_FCT keyboard int fct
672 (i.e. i8042_kbd_init())
673 VIDEO_TSTC_FCT test char fct
675 VIDEO_GETC_FCT get char fct
677 CONFIG_CONSOLE_CURSOR cursor drawing on/off
678 (requires blink timer
680 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
681 CONFIG_CONSOLE_TIME display time/date info in
683 (requires CONFIG_CMD_DATE)
684 CONFIG_VIDEO_LOGO display Linux logo in
686 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
687 linux_logo.h for logo.
688 Requires CONFIG_VIDEO_LOGO
689 CONFIG_CONSOLE_EXTRA_INFO
690 additional board info beside
693 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
694 a limited number of ANSI escape sequences (cursor control,
695 erase functions and limited graphics rendition control).
697 When CONFIG_CFB_CONSOLE is defined, video console is
698 default i/o. Serial console can be forced with
699 environment 'console=serial'.
701 When CONFIG_SILENT_CONSOLE is defined, all console
702 messages (by U-Boot and Linux!) can be silenced with
703 the "silent" environment variable. See
704 doc/README.silent for more information.
707 CONFIG_BAUDRATE - in bps
708 Select one of the baudrates listed in
709 CONFIG_SYS_BAUDRATE_TABLE, see below.
710 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
712 - Console Rx buffer length
713 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
714 the maximum receive buffer length for the SMC.
715 This option is actual only for 82xx and 8xx possible.
716 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
717 must be defined, to setup the maximum idle timeout for
720 - Pre-Console Buffer:
721 Prior to the console being initialised (i.e. serial UART
722 initialised etc) all console output is silently discarded.
723 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
724 buffer any console messages prior to the console being
725 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
726 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
727 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
728 bytes are output before the console is initialised, the
729 earlier bytes are discarded.
731 'Sane' compilers will generate smaller code if
732 CONFIG_PRE_CON_BUF_SZ is a power of 2
734 - Safe printf() functions
735 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
736 the printf() functions. These are defined in
737 include/vsprintf.h and include snprintf(), vsnprintf() and
738 so on. Code size increase is approximately 300-500 bytes.
739 If this option is not given then these functions will
740 silently discard their buffer size argument - this means
741 you are not getting any overflow checking in this case.
743 - Boot Delay: CONFIG_BOOTDELAY - in seconds
744 Delay before automatically booting the default image;
745 set to -1 to disable autoboot.
746 set to -2 to autoboot with no delay and not check for abort
747 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
749 See doc/README.autoboot for these options that
750 work with CONFIG_BOOTDELAY. None are required.
751 CONFIG_BOOT_RETRY_TIME
752 CONFIG_BOOT_RETRY_MIN
753 CONFIG_AUTOBOOT_KEYED
754 CONFIG_AUTOBOOT_PROMPT
755 CONFIG_AUTOBOOT_DELAY_STR
756 CONFIG_AUTOBOOT_STOP_STR
757 CONFIG_AUTOBOOT_DELAY_STR2
758 CONFIG_AUTOBOOT_STOP_STR2
759 CONFIG_ZERO_BOOTDELAY_CHECK
760 CONFIG_RESET_TO_RETRY
764 Only needed when CONFIG_BOOTDELAY is enabled;
765 define a command string that is automatically executed
766 when no character is read on the console interface
767 within "Boot Delay" after reset.
770 This can be used to pass arguments to the bootm
771 command. The value of CONFIG_BOOTARGS goes into the
772 environment value "bootargs".
774 CONFIG_RAMBOOT and CONFIG_NFSBOOT
775 The value of these goes into the environment as
776 "ramboot" and "nfsboot" respectively, and can be used
777 as a convenience, when switching between booting from
783 When this option is #defined, the existence of the
784 environment variable "preboot" will be checked
785 immediately before starting the CONFIG_BOOTDELAY
786 countdown and/or running the auto-boot command resp.
787 entering interactive mode.
789 This feature is especially useful when "preboot" is
790 automatically generated or modified. For an example
791 see the LWMON board specific code: here "preboot" is
792 modified when the user holds down a certain
793 combination of keys on the (special) keyboard when
796 - Serial Download Echo Mode:
798 If defined to 1, all characters received during a
799 serial download (using the "loads" command) are
800 echoed back. This might be needed by some terminal
801 emulations (like "cu"), but may as well just take
802 time on others. This setting #define's the initial
803 value of the "loads_echo" environment variable.
805 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
807 Select one of the baudrates listed in
808 CONFIG_SYS_BAUDRATE_TABLE, see below.
811 Monitor commands can be included or excluded
812 from the build by using the #include files
813 <config_cmd_all.h> and #undef'ing unwanted
814 commands, or using <config_cmd_default.h>
815 and augmenting with additional #define's
818 The default command configuration includes all commands
819 except those marked below with a "*".
821 CONFIG_CMD_ASKENV * ask for env variable
822 CONFIG_CMD_BDI bdinfo
823 CONFIG_CMD_BEDBUG * Include BedBug Debugger
824 CONFIG_CMD_BMP * BMP support
825 CONFIG_CMD_BSP * Board specific commands
826 CONFIG_CMD_BOOTD bootd
827 CONFIG_CMD_CACHE * icache, dcache
828 CONFIG_CMD_CONSOLE coninfo
829 CONFIG_CMD_CRC32 * crc32
830 CONFIG_CMD_DATE * support for RTC, date/time...
831 CONFIG_CMD_DHCP * DHCP support
832 CONFIG_CMD_DIAG * Diagnostics
833 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
834 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
835 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
836 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
837 CONFIG_CMD_DTT * Digital Therm and Thermostat
838 CONFIG_CMD_ECHO echo arguments
839 CONFIG_CMD_EDITENV edit env variable
840 CONFIG_CMD_EEPROM * EEPROM read/write support
841 CONFIG_CMD_ELF * bootelf, bootvx
842 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
843 CONFIG_CMD_ENV_FLAGS * display details about env flags
844 CONFIG_CMD_EXPORTENV * export the environment
845 CONFIG_CMD_EXT2 * ext2 command support
846 CONFIG_CMD_EXT4 * ext4 command support
847 CONFIG_CMD_SAVEENV saveenv
848 CONFIG_CMD_FDC * Floppy Disk Support
849 CONFIG_CMD_FAT * FAT command support
850 CONFIG_CMD_FDOS * Dos diskette Support
851 CONFIG_CMD_FLASH flinfo, erase, protect
852 CONFIG_CMD_FPGA FPGA device initialization support
853 CONFIG_CMD_FUSE * Device fuse support
854 CONFIG_CMD_GETTIME * Get time since boot
855 CONFIG_CMD_GO * the 'go' command (exec code)
856 CONFIG_CMD_GREPENV * search environment
857 CONFIG_CMD_HASH * calculate hash / digest
858 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
859 CONFIG_CMD_I2C * I2C serial bus support
860 CONFIG_CMD_IDE * IDE harddisk support
861 CONFIG_CMD_IMI iminfo
862 CONFIG_CMD_IMLS List all images found in NOR flash
863 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
864 CONFIG_CMD_IMMAP * IMMR dump support
865 CONFIG_CMD_IMPORTENV * import an environment
866 CONFIG_CMD_INI * import data from an ini file into the env
867 CONFIG_CMD_IRQ * irqinfo
868 CONFIG_CMD_ITEST Integer/string test of 2 values
869 CONFIG_CMD_JFFS2 * JFFS2 Support
870 CONFIG_CMD_KGDB * kgdb
871 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
872 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
874 CONFIG_CMD_LOADB loadb
875 CONFIG_CMD_LOADS loads
876 CONFIG_CMD_MD5SUM * print md5 message digest
877 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
878 CONFIG_CMD_MEMINFO * Display detailed memory information
879 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
881 CONFIG_CMD_MEMTEST * mtest
882 CONFIG_CMD_MISC Misc functions like sleep etc
883 CONFIG_CMD_MMC * MMC memory mapped support
884 CONFIG_CMD_MII * MII utility commands
885 CONFIG_CMD_MTDPARTS * MTD partition support
886 CONFIG_CMD_NAND * NAND support
887 CONFIG_CMD_NET bootp, tftpboot, rarpboot
888 CONFIG_CMD_NFS NFS support
889 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
890 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
891 CONFIG_CMD_PCI * pciinfo
892 CONFIG_CMD_PCMCIA * PCMCIA support
893 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
895 CONFIG_CMD_PORTIO * Port I/O
896 CONFIG_CMD_READ * Read raw data from partition
897 CONFIG_CMD_REGINFO * Register dump
898 CONFIG_CMD_RUN run command in env variable
899 CONFIG_CMD_SANDBOX * sb command to access sandbox features
900 CONFIG_CMD_SAVES * save S record dump
901 CONFIG_CMD_SCSI * SCSI Support
902 CONFIG_CMD_SDRAM * print SDRAM configuration information
903 (requires CONFIG_CMD_I2C)
904 CONFIG_CMD_SETGETDCR Support for DCR Register access
906 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
907 CONFIG_CMD_SHA1SUM * print sha1 memory digest
908 (requires CONFIG_CMD_MEMORY)
909 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
910 CONFIG_CMD_SOURCE "source" command Support
911 CONFIG_CMD_SPI * SPI serial bus support
912 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
913 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
914 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
915 CONFIG_CMD_TIMER * access to the system tick timer
916 CONFIG_CMD_USB * USB support
917 CONFIG_CMD_CDP * Cisco Discover Protocol support
918 CONFIG_CMD_MFSL * Microblaze FSL support
919 CONFIG_CMD_XIMG Load part of Multi Image
922 EXAMPLE: If you want all functions except of network
923 support you can write:
925 #include "config_cmd_all.h"
926 #undef CONFIG_CMD_NET
929 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
931 Note: Don't enable the "icache" and "dcache" commands
932 (configuration option CONFIG_CMD_CACHE) unless you know
933 what you (and your U-Boot users) are doing. Data
934 cache cannot be enabled on systems like the 8xx or
935 8260 (where accesses to the IMMR region must be
936 uncached), and it cannot be disabled on all other
937 systems where we (mis-) use the data cache to hold an
938 initial stack and some data.
941 XXX - this list needs to get updated!
943 - Regular expression support:
945 If this variable is defined, U-Boot is linked against
946 the SLRE (Super Light Regular Expression) library,
947 which adds regex support to some commands, as for
948 example "env grep" and "setexpr".
952 If this variable is defined, U-Boot will use a device tree
953 to configure its devices, instead of relying on statically
954 compiled #defines in the board file. This option is
955 experimental and only available on a few boards. The device
956 tree is available in the global data as gd->fdt_blob.
958 U-Boot needs to get its device tree from somewhere. This can
959 be done using one of the two options below:
962 If this variable is defined, U-Boot will embed a device tree
963 binary in its image. This device tree file should be in the
964 board directory and called <soc>-<board>.dts. The binary file
965 is then picked up in board_init_f() and made available through
966 the global data structure as gd->blob.
969 If this variable is defined, U-Boot will build a device tree
970 binary. It will be called u-boot.dtb. Architecture-specific
971 code will locate it at run-time. Generally this works by:
973 cat u-boot.bin u-boot.dtb >image.bin
975 and in fact, U-Boot does this for you, creating a file called
976 u-boot-dtb.bin which is useful in the common case. You can
977 still use the individual files if you need something more
982 If this variable is defined, it enables watchdog
983 support for the SoC. There must be support in the SoC
984 specific code for a watchdog. For the 8xx and 8260
985 CPUs, the SIU Watchdog feature is enabled in the SYPCR
986 register. When supported for a specific SoC is
987 available, then no further board specific code should
991 When using a watchdog circuitry external to the used
992 SoC, then define this variable and provide board
993 specific code for the "hw_watchdog_reset" function.
996 CONFIG_VERSION_VARIABLE
997 If this variable is defined, an environment variable
998 named "ver" is created by U-Boot showing the U-Boot
999 version as printed by the "version" command.
1000 Any change to this variable will be reverted at the
1005 When CONFIG_CMD_DATE is selected, the type of the RTC
1006 has to be selected, too. Define exactly one of the
1009 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1010 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1011 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1012 CONFIG_RTC_MC146818 - use MC146818 RTC
1013 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1014 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1015 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1016 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1017 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1018 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1019 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1020 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1023 Note that if the RTC uses I2C, then the I2C interface
1024 must also be configured. See I2C Support, below.
1027 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1028 CONFIG_PCA953X_INFO - enable pca953x info command
1030 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1031 chip-ngpio pairs that tell the PCA953X driver the number of
1032 pins supported by a particular chip.
1034 Note that if the GPIO device uses I2C, then the I2C interface
1035 must also be configured. See I2C Support, below.
1037 - Timestamp Support:
1039 When CONFIG_TIMESTAMP is selected, the timestamp
1040 (date and time) of an image is printed by image
1041 commands like bootm or iminfo. This option is
1042 automatically enabled when you select CONFIG_CMD_DATE .
1044 - Partition Labels (disklabels) Supported:
1045 Zero or more of the following:
1046 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1047 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1048 Intel architecture, USB sticks, etc.
1049 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1050 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1051 bootloader. Note 2TB partition limit; see
1053 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1055 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1056 CONFIG_CMD_SCSI) you must configure support for at
1057 least one non-MTD partition type as well.
1060 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1061 board configurations files but used nowhere!
1063 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1064 be performed by calling the function
1065 ide_set_reset(int reset)
1066 which has to be defined in a board specific file
1071 Set this to enable ATAPI support.
1076 Set this to enable support for disks larger than 137GB
1077 Also look at CONFIG_SYS_64BIT_LBA.
1078 Whithout these , LBA48 support uses 32bit variables and will 'only'
1079 support disks up to 2.1TB.
1081 CONFIG_SYS_64BIT_LBA:
1082 When enabled, makes the IDE subsystem use 64bit sector addresses.
1086 At the moment only there is only support for the
1087 SYM53C8XX SCSI controller; define
1088 CONFIG_SCSI_SYM53C8XX to enable it.
1090 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1091 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1092 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1093 maximum numbers of LUNs, SCSI ID's and target
1095 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1097 The environment variable 'scsidevs' is set to the number of
1098 SCSI devices found during the last scan.
1100 - NETWORK Support (PCI):
1102 Support for Intel 8254x/8257x gigabit chips.
1105 Utility code for direct access to the SPI bus on Intel 8257x.
1106 This does not do anything useful unless you set at least one
1107 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1109 CONFIG_E1000_SPI_GENERIC
1110 Allow generic access to the SPI bus on the Intel 8257x, for
1111 example with the "sspi" command.
1114 Management command for E1000 devices. When used on devices
1115 with SPI support you can reprogram the EEPROM from U-Boot.
1117 CONFIG_E1000_FALLBACK_MAC
1118 default MAC for empty EEPROM after production.
1121 Support for Intel 82557/82559/82559ER chips.
1122 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1123 write routine for first time initialisation.
1126 Support for Digital 2114x chips.
1127 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1128 modem chip initialisation (KS8761/QS6611).
1131 Support for National dp83815 chips.
1134 Support for National dp8382[01] gigabit chips.
1136 - NETWORK Support (other):
1138 CONFIG_DRIVER_AT91EMAC
1139 Support for AT91RM9200 EMAC.
1142 Define this to use reduced MII inteface
1144 CONFIG_DRIVER_AT91EMAC_QUIET
1145 If this defined, the driver is quiet.
1146 The driver doen't show link status messages.
1148 CONFIG_CALXEDA_XGMAC
1149 Support for the Calxeda XGMAC device
1152 Support for SMSC's LAN91C96 chips.
1154 CONFIG_LAN91C96_BASE
1155 Define this to hold the physical address
1156 of the LAN91C96's I/O space
1158 CONFIG_LAN91C96_USE_32_BIT
1159 Define this to enable 32 bit addressing
1162 Support for SMSC's LAN91C111 chip
1164 CONFIG_SMC91111_BASE
1165 Define this to hold the physical address
1166 of the device (I/O space)
1168 CONFIG_SMC_USE_32_BIT
1169 Define this if data bus is 32 bits
1171 CONFIG_SMC_USE_IOFUNCS
1172 Define this to use i/o functions instead of macros
1173 (some hardware wont work with macros)
1175 CONFIG_DRIVER_TI_EMAC
1176 Support for davinci emac
1178 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1179 Define this if you have more then 3 PHYs.
1182 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1184 CONFIG_FTGMAC100_EGIGA
1185 Define this to use GE link update with gigabit PHY.
1186 Define this if FTGMAC100 is connected to gigabit PHY.
1187 If your system has 10/100 PHY only, it might not occur
1188 wrong behavior. Because PHY usually return timeout or
1189 useless data when polling gigabit status and gigabit
1190 control registers. This behavior won't affect the
1191 correctnessof 10/100 link speed update.
1194 Support for SMSC's LAN911x and LAN921x chips
1197 Define this to hold the physical address
1198 of the device (I/O space)
1200 CONFIG_SMC911X_32_BIT
1201 Define this if data bus is 32 bits
1203 CONFIG_SMC911X_16_BIT
1204 Define this if data bus is 16 bits. If your processor
1205 automatically converts one 32 bit word to two 16 bit
1206 words you may also try CONFIG_SMC911X_32_BIT.
1209 Support for Renesas on-chip Ethernet controller
1211 CONFIG_SH_ETHER_USE_PORT
1212 Define the number of ports to be used
1214 CONFIG_SH_ETHER_PHY_ADDR
1215 Define the ETH PHY's address
1217 CONFIG_SH_ETHER_CACHE_WRITEBACK
1218 If this option is set, the driver enables cache flush.
1222 Support TPM devices.
1225 Support for i2c bus TPM devices. Only one device
1226 per system is supported at this time.
1228 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1229 Define the the i2c bus number for the TPM device
1231 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1232 Define the TPM's address on the i2c bus
1234 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1235 Define the burst count bytes upper limit
1237 CONFIG_TPM_ATMEL_TWI
1238 Support for Atmel TWI TPM device. Requires I2C support.
1241 Support for generic parallel port TPM devices. Only one device
1242 per system is supported at this time.
1244 CONFIG_TPM_TIS_BASE_ADDRESS
1245 Base address where the generic TPM device is mapped
1246 to. Contemporary x86 systems usually map it at
1250 Add tpm monitor functions.
1251 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1252 provides monitor access to authorized functions.
1255 Define this to enable the TPM support library which provides
1256 functional interfaces to some TPM commands.
1257 Requires support for a TPM device.
1259 CONFIG_TPM_AUTH_SESSIONS
1260 Define this to enable authorized functions in the TPM library.
1261 Requires CONFIG_TPM and CONFIG_SHA1.
1264 At the moment only the UHCI host controller is
1265 supported (PIP405, MIP405, MPC5200); define
1266 CONFIG_USB_UHCI to enable it.
1267 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1268 and define CONFIG_USB_STORAGE to enable the USB
1271 Supported are USB Keyboards and USB Floppy drives
1273 MPC5200 USB requires additional defines:
1275 for 528 MHz Clock: 0x0001bbbb
1279 for differential drivers: 0x00001000
1280 for single ended drivers: 0x00005000
1281 for differential drivers on PSC3: 0x00000100
1282 for single ended drivers on PSC3: 0x00004100
1283 CONFIG_SYS_USB_EVENT_POLL
1284 May be defined to allow interrupt polling
1285 instead of using asynchronous interrupts
1287 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1288 txfilltuning field in the EHCI controller on reset.
1290 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1291 interval for usb hub power-on delay.(minimum 100msec)
1294 Define the below if you wish to use the USB console.
1295 Once firmware is rebuilt from a serial console issue the
1296 command "setenv stdin usbtty; setenv stdout usbtty" and
1297 attach your USB cable. The Unix command "dmesg" should print
1298 it has found a new device. The environment variable usbtty
1299 can be set to gserial or cdc_acm to enable your device to
1300 appear to a USB host as a Linux gserial device or a
1301 Common Device Class Abstract Control Model serial device.
1302 If you select usbtty = gserial you should be able to enumerate
1304 # modprobe usbserial vendor=0xVendorID product=0xProductID
1305 else if using cdc_acm, simply setting the environment
1306 variable usbtty to be cdc_acm should suffice. The following
1307 might be defined in YourBoardName.h
1310 Define this to build a UDC device
1313 Define this to have a tty type of device available to
1314 talk to the UDC device
1317 Define this to enable the high speed support for usb
1318 device and usbtty. If this feature is enabled, a routine
1319 int is_usbd_high_speed(void)
1320 also needs to be defined by the driver to dynamically poll
1321 whether the enumeration has succeded at high speed or full
1324 CONFIG_SYS_CONSOLE_IS_IN_ENV
1325 Define this if you want stdin, stdout &/or stderr to
1329 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1330 Derive USB clock from external clock "blah"
1331 - CONFIG_SYS_USB_EXTC_CLK 0x02
1333 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1334 Derive USB clock from brgclk
1335 - CONFIG_SYS_USB_BRG_CLK 0x04
1337 If you have a USB-IF assigned VendorID then you may wish to
1338 define your own vendor specific values either in BoardName.h
1339 or directly in usbd_vendor_info.h. If you don't define
1340 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1341 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1342 should pretend to be a Linux device to it's target host.
1344 CONFIG_USBD_MANUFACTURER
1345 Define this string as the name of your company for
1346 - CONFIG_USBD_MANUFACTURER "my company"
1348 CONFIG_USBD_PRODUCT_NAME
1349 Define this string as the name of your product
1350 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1352 CONFIG_USBD_VENDORID
1353 Define this as your assigned Vendor ID from the USB
1354 Implementors Forum. This *must* be a genuine Vendor ID
1355 to avoid polluting the USB namespace.
1356 - CONFIG_USBD_VENDORID 0xFFFF
1358 CONFIG_USBD_PRODUCTID
1359 Define this as the unique Product ID
1361 - CONFIG_USBD_PRODUCTID 0xFFFF
1363 - ULPI Layer Support:
1364 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1365 the generic ULPI layer. The generic layer accesses the ULPI PHY
1366 via the platform viewport, so you need both the genric layer and
1367 the viewport enabled. Currently only Chipidea/ARC based
1368 viewport is supported.
1369 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1370 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1371 If your ULPI phy needs a different reference clock than the
1372 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1373 the appropriate value in Hz.
1376 The MMC controller on the Intel PXA is supported. To
1377 enable this define CONFIG_MMC. The MMC can be
1378 accessed from the boot prompt by mapping the device
1379 to physical memory similar to flash. Command line is
1380 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1381 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1384 Support for Renesas on-chip MMCIF controller
1386 CONFIG_SH_MMCIF_ADDR
1387 Define the base address of MMCIF registers
1390 Define the clock frequency for MMCIF
1392 - USB Device Firmware Update (DFU) class support:
1394 This enables the USB portion of the DFU USB class
1397 This enables the command "dfu" which is used to have
1398 U-Boot create a DFU class device via USB. This command
1399 requires that the "dfu_alt_info" environment variable be
1400 set and define the alt settings to expose to the host.
1403 This enables support for exposing (e)MMC devices via DFU.
1406 This enables support for exposing NAND devices via DFU.
1408 CONFIG_SYS_DFU_DATA_BUF_SIZE
1409 Dfu transfer uses a buffer before writing data to the
1410 raw storage device. Make the size (in bytes) of this buffer
1411 configurable. The size of this buffer is also configurable
1412 through the "dfu_bufsiz" environment variable.
1414 CONFIG_SYS_DFU_MAX_FILE_SIZE
1415 When updating files rather than the raw storage device,
1416 we use a static buffer to copy the file into and then write
1417 the buffer once we've been given the whole file. Define
1418 this to the maximum filesize (in bytes) for the buffer.
1419 Default is 4 MiB if undefined.
1421 - Journaling Flash filesystem support:
1422 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1423 CONFIG_JFFS2_NAND_DEV
1424 Define these for a default partition on a NAND device
1426 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1427 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1428 Define these for a default partition on a NOR device
1430 CONFIG_SYS_JFFS_CUSTOM_PART
1431 Define this to create an own partition. You have to provide a
1432 function struct part_info* jffs2_part_info(int part_num)
1434 If you define only one JFFS2 partition you may also want to
1435 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1436 to disable the command chpart. This is the default when you
1437 have not defined a custom partition
1439 - FAT(File Allocation Table) filesystem write function support:
1442 Define this to enable support for saving memory data as a
1443 file in FAT formatted partition.
1445 This will also enable the command "fatwrite" enabling the
1446 user to write files to FAT.
1448 CBFS (Coreboot Filesystem) support
1451 Define this to enable support for reading from a Coreboot
1452 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1458 Define this to enable standard (PC-Style) keyboard
1462 Standard PC keyboard driver with US (is default) and
1463 GERMAN key layout (switch via environment 'keymap=de') support.
1464 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1465 for cfb_console. Supports cursor blinking.
1468 Enables a Chrome OS keyboard using the CROS_EC interface.
1469 This uses CROS_EC to communicate with a second microcontroller
1470 which provides key scans on request.
1475 Define this to enable video support (for output to
1478 CONFIG_VIDEO_CT69000
1480 Enable Chips & Technologies 69000 Video chip
1482 CONFIG_VIDEO_SMI_LYNXEM
1483 Enable Silicon Motion SMI 712/710/810 Video chip. The
1484 video output is selected via environment 'videoout'
1485 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1488 For the CT69000 and SMI_LYNXEM drivers, videomode is
1489 selected via environment 'videomode'. Two different ways
1491 - "videomode=num" 'num' is a standard LiLo mode numbers.
1492 Following standard modes are supported (* is default):
1494 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1495 -------------+---------------------------------------------
1496 8 bits | 0x301* 0x303 0x305 0x161 0x307
1497 15 bits | 0x310 0x313 0x316 0x162 0x319
1498 16 bits | 0x311 0x314 0x317 0x163 0x31A
1499 24 bits | 0x312 0x315 0x318 ? 0x31B
1500 -------------+---------------------------------------------
1501 (i.e. setenv videomode 317; saveenv; reset;)
1503 - "videomode=bootargs" all the video parameters are parsed
1504 from the bootargs. (See drivers/video/videomodes.c)
1507 CONFIG_VIDEO_SED13806
1508 Enable Epson SED13806 driver. This driver supports 8bpp
1509 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1510 or CONFIG_VIDEO_SED13806_16BPP
1513 Enable the Freescale DIU video driver. Reference boards for
1514 SOCs that have a DIU should define this macro to enable DIU
1515 support, and should also define these other macros:
1521 CONFIG_VIDEO_SW_CURSOR
1522 CONFIG_VGA_AS_SINGLE_DEVICE
1524 CONFIG_VIDEO_BMP_LOGO
1526 The DIU driver will look for the 'video-mode' environment
1527 variable, and if defined, enable the DIU as a console during
1528 boot. See the documentation file README.video for a
1529 description of this variable.
1533 Enable the VGA video / BIOS for x86. The alternative if you
1534 are using coreboot is to use the coreboot frame buffer
1541 Define this to enable a custom keyboard support.
1542 This simply calls drv_keyboard_init() which must be
1543 defined in your board-specific files.
1544 The only board using this so far is RBC823.
1546 - LCD Support: CONFIG_LCD
1548 Define this to enable LCD support (for output to LCD
1549 display); also select one of the supported displays
1550 by defining one of these:
1554 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1556 CONFIG_NEC_NL6448AC33:
1558 NEC NL6448AC33-18. Active, color, single scan.
1560 CONFIG_NEC_NL6448BC20
1562 NEC NL6448BC20-08. 6.5", 640x480.
1563 Active, color, single scan.
1565 CONFIG_NEC_NL6448BC33_54
1567 NEC NL6448BC33-54. 10.4", 640x480.
1568 Active, color, single scan.
1572 Sharp 320x240. Active, color, single scan.
1573 It isn't 16x9, and I am not sure what it is.
1575 CONFIG_SHARP_LQ64D341
1577 Sharp LQ64D341 display, 640x480.
1578 Active, color, single scan.
1582 HLD1045 display, 640x480.
1583 Active, color, single scan.
1587 Optrex CBL50840-2 NF-FW 99 22 M5
1589 Hitachi LMG6912RPFC-00T
1593 320x240. Black & white.
1595 Normally display is black on white background; define
1596 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1598 CONFIG_LCD_ALIGNMENT
1600 Normally the LCD is page-aligned (tyically 4KB). If this is
1601 defined then the LCD will be aligned to this value instead.
1602 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1603 here, since it is cheaper to change data cache settings on
1604 a per-section basis.
1606 CONFIG_CONSOLE_SCROLL_LINES
1608 When the console need to be scrolled, this is the number of
1609 lines to scroll by. It defaults to 1. Increasing this makes
1610 the console jump but can help speed up operation when scrolling
1615 Support drawing of RLE8-compressed bitmaps on the LCD.
1619 Enables an 'i2c edid' command which can read EDID
1620 information over I2C from an attached LCD display.
1622 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1624 If this option is set, the environment is checked for
1625 a variable "splashimage". If found, the usual display
1626 of logo, copyright and system information on the LCD
1627 is suppressed and the BMP image at the address
1628 specified in "splashimage" is loaded instead. The
1629 console is redirected to the "nulldev", too. This
1630 allows for a "silent" boot where a splash screen is
1631 loaded very quickly after power-on.
1633 CONFIG_SPLASHIMAGE_GUARD
1635 If this option is set, then U-Boot will prevent the environment
1636 variable "splashimage" from being set to a problematic address
1637 (see README.displaying-bmps and README.arm-unaligned-accesses).
1638 This option is useful for targets where, due to alignment
1639 restrictions, an improperly aligned BMP image will cause a data
1640 abort. If you think you will not have problems with unaligned
1641 accesses (for example because your toolchain prevents them)
1642 there is no need to set this option.
1644 CONFIG_SPLASH_SCREEN_ALIGN
1646 If this option is set the splash image can be freely positioned
1647 on the screen. Environment variable "splashpos" specifies the
1648 position as "x,y". If a positive number is given it is used as
1649 number of pixel from left/top. If a negative number is given it
1650 is used as number of pixel from right/bottom. You can also
1651 specify 'm' for centering the image.
1654 setenv splashpos m,m
1655 => image at center of screen
1657 setenv splashpos 30,20
1658 => image at x = 30 and y = 20
1660 setenv splashpos -10,m
1661 => vertically centered image
1662 at x = dspWidth - bmpWidth - 9
1664 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1666 If this option is set, additionally to standard BMP
1667 images, gzipped BMP images can be displayed via the
1668 splashscreen support or the bmp command.
1670 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1672 If this option is set, 8-bit RLE compressed BMP images
1673 can be displayed via the splashscreen support or the
1676 - Do compresssing for memory range:
1679 If this option is set, it would use zlib deflate method
1680 to compress the specified memory at its best effort.
1682 - Compression support:
1685 If this option is set, support for bzip2 compressed
1686 images is included. If not, only uncompressed and gzip
1687 compressed images are supported.
1689 NOTE: the bzip2 algorithm requires a lot of RAM, so
1690 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1695 If this option is set, support for lzma compressed
1698 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1699 requires an amount of dynamic memory that is given by the
1702 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1704 Where lc and lp stand for, respectively, Literal context bits
1705 and Literal pos bits.
1707 This value is upper-bounded by 14MB in the worst case. Anyway,
1708 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1709 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1710 a very small buffer.
1712 Use the lzmainfo tool to determinate the lc and lp values and
1713 then calculate the amount of needed dynamic memory (ensuring
1714 the appropriate CONFIG_SYS_MALLOC_LEN value).
1719 The address of PHY on MII bus.
1721 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1723 The clock frequency of the MII bus
1727 If this option is set, support for speed/duplex
1728 detection of gigabit PHY is included.
1730 CONFIG_PHY_RESET_DELAY
1732 Some PHY like Intel LXT971A need extra delay after
1733 reset before any MII register access is possible.
1734 For such PHY, set this option to the usec delay
1735 required. (minimum 300usec for LXT971A)
1737 CONFIG_PHY_CMD_DELAY (ppc4xx)
1739 Some PHY like Intel LXT971A need extra delay after
1740 command issued before MII status register can be read
1750 Define a default value for Ethernet address to use
1751 for the respective Ethernet interface, in case this
1752 is not determined automatically.
1757 Define a default value for the IP address to use for
1758 the default Ethernet interface, in case this is not
1759 determined through e.g. bootp.
1760 (Environment variable "ipaddr")
1762 - Server IP address:
1765 Defines a default value for the IP address of a TFTP
1766 server to contact when using the "tftboot" command.
1767 (Environment variable "serverip")
1769 CONFIG_KEEP_SERVERADDR
1771 Keeps the server's MAC address, in the env 'serveraddr'
1772 for passing to bootargs (like Linux's netconsole option)
1774 - Gateway IP address:
1777 Defines a default value for the IP address of the
1778 default router where packets to other networks are
1780 (Environment variable "gatewayip")
1785 Defines a default value for the subnet mask (or
1786 routing prefix) which is used to determine if an IP
1787 address belongs to the local subnet or needs to be
1788 forwarded through a router.
1789 (Environment variable "netmask")
1791 - Multicast TFTP Mode:
1794 Defines whether you want to support multicast TFTP as per
1795 rfc-2090; for example to work with atftp. Lets lots of targets
1796 tftp down the same boot image concurrently. Note: the Ethernet
1797 driver in use must provide a function: mcast() to join/leave a
1800 - BOOTP Recovery Mode:
1801 CONFIG_BOOTP_RANDOM_DELAY
1803 If you have many targets in a network that try to
1804 boot using BOOTP, you may want to avoid that all
1805 systems send out BOOTP requests at precisely the same
1806 moment (which would happen for instance at recovery
1807 from a power failure, when all systems will try to
1808 boot, thus flooding the BOOTP server. Defining
1809 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1810 inserted before sending out BOOTP requests. The
1811 following delays are inserted then:
1813 1st BOOTP request: delay 0 ... 1 sec
1814 2nd BOOTP request: delay 0 ... 2 sec
1815 3rd BOOTP request: delay 0 ... 4 sec
1817 BOOTP requests: delay 0 ... 8 sec
1819 - DHCP Advanced Options:
1820 You can fine tune the DHCP functionality by defining
1821 CONFIG_BOOTP_* symbols:
1823 CONFIG_BOOTP_SUBNETMASK
1824 CONFIG_BOOTP_GATEWAY
1825 CONFIG_BOOTP_HOSTNAME
1826 CONFIG_BOOTP_NISDOMAIN
1827 CONFIG_BOOTP_BOOTPATH
1828 CONFIG_BOOTP_BOOTFILESIZE
1831 CONFIG_BOOTP_SEND_HOSTNAME
1832 CONFIG_BOOTP_NTPSERVER
1833 CONFIG_BOOTP_TIMEOFFSET
1834 CONFIG_BOOTP_VENDOREX
1835 CONFIG_BOOTP_MAY_FAIL
1837 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1838 environment variable, not the BOOTP server.
1840 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1841 after the configured retry count, the call will fail
1842 instead of starting over. This can be used to fail over
1843 to Link-local IP address configuration if the DHCP server
1846 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1847 serverip from a DHCP server, it is possible that more
1848 than one DNS serverip is offered to the client.
1849 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1850 serverip will be stored in the additional environment
1851 variable "dnsip2". The first DNS serverip is always
1852 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1855 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1856 to do a dynamic update of a DNS server. To do this, they
1857 need the hostname of the DHCP requester.
1858 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1859 of the "hostname" environment variable is passed as
1860 option 12 to the DHCP server.
1862 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1864 A 32bit value in microseconds for a delay between
1865 receiving a "DHCP Offer" and sending the "DHCP Request".
1866 This fixes a problem with certain DHCP servers that don't
1867 respond 100% of the time to a "DHCP request". E.g. On an
1868 AT91RM9200 processor running at 180MHz, this delay needed
1869 to be *at least* 15,000 usec before a Windows Server 2003
1870 DHCP server would reply 100% of the time. I recommend at
1871 least 50,000 usec to be safe. The alternative is to hope
1872 that one of the retries will be successful but note that
1873 the DHCP timeout and retry process takes a longer than
1876 - Link-local IP address negotiation:
1877 Negotiate with other link-local clients on the local network
1878 for an address that doesn't require explicit configuration.
1879 This is especially useful if a DHCP server cannot be guaranteed
1880 to exist in all environments that the device must operate.
1882 See doc/README.link-local for more information.
1885 CONFIG_CDP_DEVICE_ID
1887 The device id used in CDP trigger frames.
1889 CONFIG_CDP_DEVICE_ID_PREFIX
1891 A two character string which is prefixed to the MAC address
1896 A printf format string which contains the ascii name of
1897 the port. Normally is set to "eth%d" which sets
1898 eth0 for the first Ethernet, eth1 for the second etc.
1900 CONFIG_CDP_CAPABILITIES
1902 A 32bit integer which indicates the device capabilities;
1903 0x00000010 for a normal host which does not forwards.
1907 An ascii string containing the version of the software.
1911 An ascii string containing the name of the platform.
1915 A 32bit integer sent on the trigger.
1917 CONFIG_CDP_POWER_CONSUMPTION
1919 A 16bit integer containing the power consumption of the
1920 device in .1 of milliwatts.
1922 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1924 A byte containing the id of the VLAN.
1926 - Status LED: CONFIG_STATUS_LED
1928 Several configurations allow to display the current
1929 status using a LED. For instance, the LED will blink
1930 fast while running U-Boot code, stop blinking as
1931 soon as a reply to a BOOTP request was received, and
1932 start blinking slow once the Linux kernel is running
1933 (supported by a status LED driver in the Linux
1934 kernel). Defining CONFIG_STATUS_LED enables this
1937 - CAN Support: CONFIG_CAN_DRIVER
1939 Defining CONFIG_CAN_DRIVER enables CAN driver support
1940 on those systems that support this (optional)
1941 feature, like the TQM8xxL modules.
1943 - I2C Support: CONFIG_SYS_I2C
1945 This enable the NEW i2c subsystem, and will allow you to use
1946 i2c commands at the u-boot command line (as long as you set
1947 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1948 based realtime clock chips or other i2c devices. See
1949 common/cmd_i2c.c for a description of the command line
1952 ported i2c driver to the new framework:
1953 - drivers/i2c/soft_i2c.c:
1954 - activate first bus with CONFIG_SYS_I2C_SOFT define
1955 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1956 for defining speed and slave address
1957 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1958 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1959 for defining speed and slave address
1960 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1961 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1962 for defining speed and slave address
1963 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1964 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1965 for defining speed and slave address
1967 - drivers/i2c/fsl_i2c.c:
1968 - activate i2c driver with CONFIG_SYS_I2C_FSL
1969 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1970 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1971 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1973 - If your board supports a second fsl i2c bus, define
1974 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1975 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1976 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1979 - drivers/i2c/tegra_i2c.c:
1980 - activate this driver with CONFIG_SYS_I2C_TEGRA
1981 - This driver adds 4 i2c buses with a fix speed from
1982 100000 and the slave addr 0!
1984 - drivers/i2c/ppc4xx_i2c.c
1985 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1986 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1987 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1991 CONFIG_SYS_NUM_I2C_BUSES
1992 Hold the number of i2c busses you want to use. If you
1993 don't use/have i2c muxes on your i2c bus, this
1994 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
1997 CONFIG_SYS_I2C_DIRECT_BUS
1998 define this, if you don't use i2c muxes on your hardware.
1999 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2002 CONFIG_SYS_I2C_MAX_HOPS
2003 define how many muxes are maximal consecutively connected
2004 on one i2c bus. If you not use i2c muxes, omit this
2007 CONFIG_SYS_I2C_BUSES
2008 hold a list of busses you want to use, only used if
2009 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2010 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2011 CONFIG_SYS_NUM_I2C_BUSES = 9:
2013 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2014 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2015 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2016 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2017 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2018 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2019 {1, {I2C_NULL_HOP}}, \
2020 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2021 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2025 bus 0 on adapter 0 without a mux
2026 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2027 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2028 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2029 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2030 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2031 bus 6 on adapter 1 without a mux
2032 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2033 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2035 If you do not have i2c muxes on your board, omit this define.
2037 - Legacy I2C Support: CONFIG_HARD_I2C
2039 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2040 provides the following compelling advantages:
2042 - more than one i2c adapter is usable
2043 - approved multibus support
2044 - better i2c mux support
2046 ** Please consider updating your I2C driver now. **
2048 These enable legacy I2C serial bus commands. Defining
2049 CONFIG_HARD_I2C will include the appropriate I2C driver
2050 for the selected CPU.
2052 This will allow you to use i2c commands at the u-boot
2053 command line (as long as you set CONFIG_CMD_I2C in
2054 CONFIG_COMMANDS) and communicate with i2c based realtime
2055 clock chips. See common/cmd_i2c.c for a description of the
2056 command line interface.
2058 CONFIG_HARD_I2C selects a hardware I2C controller.
2060 There are several other quantities that must also be
2061 defined when you define CONFIG_HARD_I2C.
2063 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2064 to be the frequency (in Hz) at which you wish your i2c bus
2065 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2066 the CPU's i2c node address).
2068 Now, the u-boot i2c code for the mpc8xx
2069 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2070 and so its address should therefore be cleared to 0 (See,
2071 eg, MPC823e User's Manual p.16-473). So, set
2072 CONFIG_SYS_I2C_SLAVE to 0.
2074 CONFIG_SYS_I2C_INIT_MPC5XXX
2076 When a board is reset during an i2c bus transfer
2077 chips might think that the current transfer is still
2078 in progress. Reset the slave devices by sending start
2079 commands until the slave device responds.
2081 That's all that's required for CONFIG_HARD_I2C.
2083 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2084 then the following macros need to be defined (examples are
2085 from include/configs/lwmon.h):
2089 (Optional). Any commands necessary to enable the I2C
2090 controller or configure ports.
2092 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2096 (Only for MPC8260 CPU). The I/O port to use (the code
2097 assumes both bits are on the same port). Valid values
2098 are 0..3 for ports A..D.
2102 The code necessary to make the I2C data line active
2103 (driven). If the data line is open collector, this
2106 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2110 The code necessary to make the I2C data line tri-stated
2111 (inactive). If the data line is open collector, this
2114 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2118 Code that returns true if the I2C data line is high,
2121 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2125 If <bit> is true, sets the I2C data line high. If it
2126 is false, it clears it (low).
2128 eg: #define I2C_SDA(bit) \
2129 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2130 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2134 If <bit> is true, sets the I2C clock line high. If it
2135 is false, it clears it (low).
2137 eg: #define I2C_SCL(bit) \
2138 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2139 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2143 This delay is invoked four times per clock cycle so this
2144 controls the rate of data transfer. The data rate thus
2145 is 1 / (I2C_DELAY * 4). Often defined to be something
2148 #define I2C_DELAY udelay(2)
2150 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2152 If your arch supports the generic GPIO framework (asm/gpio.h),
2153 then you may alternatively define the two GPIOs that are to be
2154 used as SCL / SDA. Any of the previous I2C_xxx macros will
2155 have GPIO-based defaults assigned to them as appropriate.
2157 You should define these to the GPIO value as given directly to
2158 the generic GPIO functions.
2160 CONFIG_SYS_I2C_INIT_BOARD
2162 When a board is reset during an i2c bus transfer
2163 chips might think that the current transfer is still
2164 in progress. On some boards it is possible to access
2165 the i2c SCLK line directly, either by using the
2166 processor pin as a GPIO or by having a second pin
2167 connected to the bus. If this option is defined a
2168 custom i2c_init_board() routine in boards/xxx/board.c
2169 is run early in the boot sequence.
2171 CONFIG_SYS_I2C_BOARD_LATE_INIT
2173 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2174 defined a custom i2c_board_late_init() routine in
2175 boards/xxx/board.c is run AFTER the operations in i2c_init()
2176 is completed. This callpoint can be used to unreset i2c bus
2177 using CPU i2c controller register accesses for CPUs whose i2c
2178 controller provide such a method. It is called at the end of
2179 i2c_init() to allow i2c_init operations to setup the i2c bus
2180 controller on the CPU (e.g. setting bus speed & slave address).
2182 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2184 This option enables configuration of bi_iic_fast[] flags
2185 in u-boot bd_info structure based on u-boot environment
2186 variable "i2cfast". (see also i2cfast)
2188 CONFIG_I2C_MULTI_BUS
2190 This option allows the use of multiple I2C buses, each of which
2191 must have a controller. At any point in time, only one bus is
2192 active. To switch to a different bus, use the 'i2c dev' command.
2193 Note that bus numbering is zero-based.
2195 CONFIG_SYS_I2C_NOPROBES
2197 This option specifies a list of I2C devices that will be skipped
2198 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2199 is set, specify a list of bus-device pairs. Otherwise, specify
2200 a 1D array of device addresses
2203 #undef CONFIG_I2C_MULTI_BUS
2204 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2206 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2208 #define CONFIG_I2C_MULTI_BUS
2209 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2211 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2213 CONFIG_SYS_SPD_BUS_NUM
2215 If defined, then this indicates the I2C bus number for DDR SPD.
2216 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2218 CONFIG_SYS_RTC_BUS_NUM
2220 If defined, then this indicates the I2C bus number for the RTC.
2221 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2223 CONFIG_SYS_DTT_BUS_NUM
2225 If defined, then this indicates the I2C bus number for the DTT.
2226 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2228 CONFIG_SYS_I2C_DTT_ADDR:
2230 If defined, specifies the I2C address of the DTT device.
2231 If not defined, then U-Boot uses predefined value for
2232 specified DTT device.
2234 CONFIG_SOFT_I2C_READ_REPEATED_START
2236 defining this will force the i2c_read() function in
2237 the soft_i2c driver to perform an I2C repeated start
2238 between writing the address pointer and reading the
2239 data. If this define is omitted the default behaviour
2240 of doing a stop-start sequence will be used. Most I2C
2241 devices can use either method, but some require one or
2244 - SPI Support: CONFIG_SPI
2246 Enables SPI driver (so far only tested with
2247 SPI EEPROM, also an instance works with Crystal A/D and
2248 D/As on the SACSng board)
2252 Enables the driver for SPI controller on SuperH. Currently
2253 only SH7757 is supported.
2257 Enables extended (16-bit) SPI EEPROM addressing.
2258 (symmetrical to CONFIG_I2C_X)
2262 Enables a software (bit-bang) SPI driver rather than
2263 using hardware support. This is a general purpose
2264 driver that only requires three general I/O port pins
2265 (two outputs, one input) to function. If this is
2266 defined, the board configuration must define several
2267 SPI configuration items (port pins to use, etc). For
2268 an example, see include/configs/sacsng.h.
2272 Enables a hardware SPI driver for general-purpose reads
2273 and writes. As with CONFIG_SOFT_SPI, the board configuration
2274 must define a list of chip-select function pointers.
2275 Currently supported on some MPC8xxx processors. For an
2276 example, see include/configs/mpc8349emds.h.
2280 Enables the driver for the SPI controllers on i.MX and MXC
2281 SoCs. Currently i.MX31/35/51 are supported.
2283 - FPGA Support: CONFIG_FPGA
2285 Enables FPGA subsystem.
2287 CONFIG_FPGA_<vendor>
2289 Enables support for specific chip vendors.
2292 CONFIG_FPGA_<family>
2294 Enables support for FPGA family.
2295 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2299 Specify the number of FPGA devices to support.
2301 CONFIG_SYS_FPGA_PROG_FEEDBACK
2303 Enable printing of hash marks during FPGA configuration.
2305 CONFIG_SYS_FPGA_CHECK_BUSY
2307 Enable checks on FPGA configuration interface busy
2308 status by the configuration function. This option
2309 will require a board or device specific function to
2314 If defined, a function that provides delays in the FPGA
2315 configuration driver.
2317 CONFIG_SYS_FPGA_CHECK_CTRLC
2318 Allow Control-C to interrupt FPGA configuration
2320 CONFIG_SYS_FPGA_CHECK_ERROR
2322 Check for configuration errors during FPGA bitfile
2323 loading. For example, abort during Virtex II
2324 configuration if the INIT_B line goes low (which
2325 indicated a CRC error).
2327 CONFIG_SYS_FPGA_WAIT_INIT
2329 Maximum time to wait for the INIT_B line to deassert
2330 after PROB_B has been deasserted during a Virtex II
2331 FPGA configuration sequence. The default time is 500
2334 CONFIG_SYS_FPGA_WAIT_BUSY
2336 Maximum time to wait for BUSY to deassert during
2337 Virtex II FPGA configuration. The default is 5 ms.
2339 CONFIG_SYS_FPGA_WAIT_CONFIG
2341 Time to wait after FPGA configuration. The default is
2344 - Configuration Management:
2347 If defined, this string will be added to the U-Boot
2348 version information (U_BOOT_VERSION)
2350 - Vendor Parameter Protection:
2352 U-Boot considers the values of the environment
2353 variables "serial#" (Board Serial Number) and
2354 "ethaddr" (Ethernet Address) to be parameters that
2355 are set once by the board vendor / manufacturer, and
2356 protects these variables from casual modification by
2357 the user. Once set, these variables are read-only,
2358 and write or delete attempts are rejected. You can
2359 change this behaviour:
2361 If CONFIG_ENV_OVERWRITE is #defined in your config
2362 file, the write protection for vendor parameters is
2363 completely disabled. Anybody can change or delete
2366 Alternatively, if you #define _both_ CONFIG_ETHADDR
2367 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2368 Ethernet address is installed in the environment,
2369 which can be changed exactly ONCE by the user. [The
2370 serial# is unaffected by this, i. e. it remains
2373 The same can be accomplished in a more flexible way
2374 for any variable by configuring the type of access
2375 to allow for those variables in the ".flags" variable
2376 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2381 Define this variable to enable the reservation of
2382 "protected RAM", i. e. RAM which is not overwritten
2383 by U-Boot. Define CONFIG_PRAM to hold the number of
2384 kB you want to reserve for pRAM. You can overwrite
2385 this default value by defining an environment
2386 variable "pram" to the number of kB you want to
2387 reserve. Note that the board info structure will
2388 still show the full amount of RAM. If pRAM is
2389 reserved, a new environment variable "mem" will
2390 automatically be defined to hold the amount of
2391 remaining RAM in a form that can be passed as boot
2392 argument to Linux, for instance like that:
2394 setenv bootargs ... mem=\${mem}
2397 This way you can tell Linux not to use this memory,
2398 either, which results in a memory region that will
2399 not be affected by reboots.
2401 *WARNING* If your board configuration uses automatic
2402 detection of the RAM size, you must make sure that
2403 this memory test is non-destructive. So far, the
2404 following board configurations are known to be
2407 IVMS8, IVML24, SPD8xx, TQM8xxL,
2408 HERMES, IP860, RPXlite, LWMON,
2411 - Access to physical memory region (> 4GB)
2412 Some basic support is provided for operations on memory not
2413 normally accessible to U-Boot - e.g. some architectures
2414 support access to more than 4GB of memory on 32-bit
2415 machines using physical address extension or similar.
2416 Define CONFIG_PHYSMEM to access this basic support, which
2417 currently only supports clearing the memory.
2422 Define this variable to stop the system in case of a
2423 fatal error, so that you have to reset it manually.
2424 This is probably NOT a good idea for an embedded
2425 system where you want the system to reboot
2426 automatically as fast as possible, but it may be
2427 useful during development since you can try to debug
2428 the conditions that lead to the situation.
2430 CONFIG_NET_RETRY_COUNT
2432 This variable defines the number of retries for
2433 network operations like ARP, RARP, TFTP, or BOOTP
2434 before giving up the operation. If not defined, a
2435 default value of 5 is used.
2439 Timeout waiting for an ARP reply in milliseconds.
2443 Timeout in milliseconds used in NFS protocol.
2444 If you encounter "ERROR: Cannot umount" in nfs command,
2445 try longer timeout such as
2446 #define CONFIG_NFS_TIMEOUT 10000UL
2448 - Command Interpreter:
2449 CONFIG_AUTO_COMPLETE
2451 Enable auto completion of commands using TAB.
2453 Note that this feature has NOT been implemented yet
2454 for the "hush" shell.
2457 CONFIG_SYS_HUSH_PARSER
2459 Define this variable to enable the "hush" shell (from
2460 Busybox) as command line interpreter, thus enabling
2461 powerful command line syntax like
2462 if...then...else...fi conditionals or `&&' and '||'
2463 constructs ("shell scripts").
2465 If undefined, you get the old, much simpler behaviour
2466 with a somewhat smaller memory footprint.
2469 CONFIG_SYS_PROMPT_HUSH_PS2
2471 This defines the secondary prompt string, which is
2472 printed when the command interpreter needs more input
2473 to complete a command. Usually "> ".
2477 In the current implementation, the local variables
2478 space and global environment variables space are
2479 separated. Local variables are those you define by
2480 simply typing `name=value'. To access a local
2481 variable later on, you have write `$name' or
2482 `${name}'; to execute the contents of a variable
2483 directly type `$name' at the command prompt.
2485 Global environment variables are those you use
2486 setenv/printenv to work with. To run a command stored
2487 in such a variable, you need to use the run command,
2488 and you must not use the '$' sign to access them.
2490 To store commands and special characters in a
2491 variable, please use double quotation marks
2492 surrounding the whole text of the variable, instead
2493 of the backslashes before semicolons and special
2496 - Commandline Editing and History:
2497 CONFIG_CMDLINE_EDITING
2499 Enable editing and History functions for interactive
2500 commandline input operations
2502 - Default Environment:
2503 CONFIG_EXTRA_ENV_SETTINGS
2505 Define this to contain any number of null terminated
2506 strings (variable = value pairs) that will be part of
2507 the default environment compiled into the boot image.
2509 For example, place something like this in your
2510 board's config file:
2512 #define CONFIG_EXTRA_ENV_SETTINGS \
2516 Warning: This method is based on knowledge about the
2517 internal format how the environment is stored by the
2518 U-Boot code. This is NOT an official, exported
2519 interface! Although it is unlikely that this format
2520 will change soon, there is no guarantee either.
2521 You better know what you are doing here.
2523 Note: overly (ab)use of the default environment is
2524 discouraged. Make sure to check other ways to preset
2525 the environment like the "source" command or the
2528 CONFIG_ENV_VARS_UBOOT_CONFIG
2530 Define this in order to add variables describing the
2531 U-Boot build configuration to the default environment.
2532 These will be named arch, cpu, board, vendor, and soc.
2534 Enabling this option will cause the following to be defined:
2542 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2544 Define this in order to add variables describing certain
2545 run-time determined information about the hardware to the
2546 environment. These will be named board_name, board_rev.
2548 CONFIG_DELAY_ENVIRONMENT
2550 Normally the environment is loaded when the board is
2551 intialised so that it is available to U-Boot. This inhibits
2552 that so that the environment is not available until
2553 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2554 this is instead controlled by the value of
2555 /config/load-environment.
2557 - DataFlash Support:
2558 CONFIG_HAS_DATAFLASH
2560 Defining this option enables DataFlash features and
2561 allows to read/write in Dataflash via the standard
2564 - Serial Flash support
2567 Defining this option enables SPI flash commands
2568 'sf probe/read/write/erase/update'.
2570 Usage requires an initial 'probe' to define the serial
2571 flash parameters, followed by read/write/erase/update
2574 The following defaults may be provided by the platform
2575 to handle the common case when only a single serial
2576 flash is present on the system.
2578 CONFIG_SF_DEFAULT_BUS Bus identifier
2579 CONFIG_SF_DEFAULT_CS Chip-select
2580 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2581 CONFIG_SF_DEFAULT_SPEED in Hz
2585 Define this option to include a destructive SPI flash
2588 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2590 Define this option to use the Bank addr/Extended addr
2591 support on SPI flashes which has size > 16Mbytes.
2593 - SystemACE Support:
2596 Adding this option adds support for Xilinx SystemACE
2597 chips attached via some sort of local bus. The address
2598 of the chip must also be defined in the
2599 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2601 #define CONFIG_SYSTEMACE
2602 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2604 When SystemACE support is added, the "ace" device type
2605 becomes available to the fat commands, i.e. fatls.
2607 - TFTP Fixed UDP Port:
2610 If this is defined, the environment variable tftpsrcp
2611 is used to supply the TFTP UDP source port value.
2612 If tftpsrcp isn't defined, the normal pseudo-random port
2613 number generator is used.
2615 Also, the environment variable tftpdstp is used to supply
2616 the TFTP UDP destination port value. If tftpdstp isn't
2617 defined, the normal port 69 is used.
2619 The purpose for tftpsrcp is to allow a TFTP server to
2620 blindly start the TFTP transfer using the pre-configured
2621 target IP address and UDP port. This has the effect of
2622 "punching through" the (Windows XP) firewall, allowing
2623 the remainder of the TFTP transfer to proceed normally.
2624 A better solution is to properly configure the firewall,
2625 but sometimes that is not allowed.
2630 This enables a generic 'hash' command which can produce
2631 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2635 Enable the hash verify command (hash -v). This adds to code
2638 CONFIG_SHA1 - support SHA1 hashing
2639 CONFIG_SHA256 - support SHA256 hashing
2641 Note: There is also a sha1sum command, which should perhaps
2642 be deprecated in favour of 'hash sha1'.
2647 This enables the RSA algorithm used for FIT image verification
2648 in U-Boot. See doc/uImage/signature for more information.
2650 The signing part is build into mkimage regardless of this
2654 - Show boot progress:
2655 CONFIG_SHOW_BOOT_PROGRESS
2657 Defining this option allows to add some board-
2658 specific code (calling a user-provided function
2659 "show_boot_progress(int)") that enables you to show
2660 the system's boot progress on some display (for
2661 example, some LED's) on your board. At the moment,
2662 the following checkpoints are implemented:
2664 - Detailed boot stage timing
2666 Define this option to get detailed timing of each stage
2667 of the boot process.
2669 CONFIG_BOOTSTAGE_USER_COUNT
2670 This is the number of available user bootstage records.
2671 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2672 a new ID will be allocated from this stash. If you exceed
2673 the limit, recording will stop.
2675 CONFIG_BOOTSTAGE_REPORT
2676 Define this to print a report before boot, similar to this:
2678 Timer summary in microseconds:
2681 3,575,678 3,575,678 board_init_f start
2682 3,575,695 17 arch_cpu_init A9
2683 3,575,777 82 arch_cpu_init done
2684 3,659,598 83,821 board_init_r start
2685 3,910,375 250,777 main_loop
2686 29,916,167 26,005,792 bootm_start
2687 30,361,327 445,160 start_kernel
2689 CONFIG_CMD_BOOTSTAGE
2690 Add a 'bootstage' command which supports printing a report
2691 and un/stashing of bootstage data.
2693 CONFIG_BOOTSTAGE_FDT
2694 Stash the bootstage information in the FDT. A root 'bootstage'
2695 node is created with each bootstage id as a child. Each child
2696 has a 'name' property and either 'mark' containing the
2697 mark time in microsecond, or 'accum' containing the
2698 accumulated time for that bootstage id in microseconds.
2703 name = "board_init_f";
2712 Code in the Linux kernel can find this in /proc/devicetree.
2714 Legacy uImage format:
2717 1 common/cmd_bootm.c before attempting to boot an image
2718 -1 common/cmd_bootm.c Image header has bad magic number
2719 2 common/cmd_bootm.c Image header has correct magic number
2720 -2 common/cmd_bootm.c Image header has bad checksum
2721 3 common/cmd_bootm.c Image header has correct checksum
2722 -3 common/cmd_bootm.c Image data has bad checksum
2723 4 common/cmd_bootm.c Image data has correct checksum
2724 -4 common/cmd_bootm.c Image is for unsupported architecture
2725 5 common/cmd_bootm.c Architecture check OK
2726 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2727 6 common/cmd_bootm.c Image Type check OK
2728 -6 common/cmd_bootm.c gunzip uncompression error
2729 -7 common/cmd_bootm.c Unimplemented compression type
2730 7 common/cmd_bootm.c Uncompression OK
2731 8 common/cmd_bootm.c No uncompress/copy overwrite error
2732 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2734 9 common/image.c Start initial ramdisk verification
2735 -10 common/image.c Ramdisk header has bad magic number
2736 -11 common/image.c Ramdisk header has bad checksum
2737 10 common/image.c Ramdisk header is OK
2738 -12 common/image.c Ramdisk data has bad checksum
2739 11 common/image.c Ramdisk data has correct checksum
2740 12 common/image.c Ramdisk verification complete, start loading
2741 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2742 13 common/image.c Start multifile image verification
2743 14 common/image.c No initial ramdisk, no multifile, continue.
2745 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2747 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2748 -31 post/post.c POST test failed, detected by post_output_backlog()
2749 -32 post/post.c POST test failed, detected by post_run_single()
2751 34 common/cmd_doc.c before loading a Image from a DOC device
2752 -35 common/cmd_doc.c Bad usage of "doc" command
2753 35 common/cmd_doc.c correct usage of "doc" command
2754 -36 common/cmd_doc.c No boot device
2755 36 common/cmd_doc.c correct boot device
2756 -37 common/cmd_doc.c Unknown Chip ID on boot device
2757 37 common/cmd_doc.c correct chip ID found, device available
2758 -38 common/cmd_doc.c Read Error on boot device
2759 38 common/cmd_doc.c reading Image header from DOC device OK
2760 -39 common/cmd_doc.c Image header has bad magic number
2761 39 common/cmd_doc.c Image header has correct magic number
2762 -40 common/cmd_doc.c Error reading Image from DOC device
2763 40 common/cmd_doc.c Image header has correct magic number
2764 41 common/cmd_ide.c before loading a Image from a IDE device
2765 -42 common/cmd_ide.c Bad usage of "ide" command
2766 42 common/cmd_ide.c correct usage of "ide" command
2767 -43 common/cmd_ide.c No boot device
2768 43 common/cmd_ide.c boot device found
2769 -44 common/cmd_ide.c Device not available
2770 44 common/cmd_ide.c Device available
2771 -45 common/cmd_ide.c wrong partition selected
2772 45 common/cmd_ide.c partition selected
2773 -46 common/cmd_ide.c Unknown partition table
2774 46 common/cmd_ide.c valid partition table found
2775 -47 common/cmd_ide.c Invalid partition type
2776 47 common/cmd_ide.c correct partition type
2777 -48 common/cmd_ide.c Error reading Image Header on boot device
2778 48 common/cmd_ide.c reading Image Header from IDE device OK
2779 -49 common/cmd_ide.c Image header has bad magic number
2780 49 common/cmd_ide.c Image header has correct magic number
2781 -50 common/cmd_ide.c Image header has bad checksum
2782 50 common/cmd_ide.c Image header has correct checksum
2783 -51 common/cmd_ide.c Error reading Image from IDE device
2784 51 common/cmd_ide.c reading Image from IDE device OK
2785 52 common/cmd_nand.c before loading a Image from a NAND device
2786 -53 common/cmd_nand.c Bad usage of "nand" command
2787 53 common/cmd_nand.c correct usage of "nand" command
2788 -54 common/cmd_nand.c No boot device
2789 54 common/cmd_nand.c boot device found
2790 -55 common/cmd_nand.c Unknown Chip ID on boot device
2791 55 common/cmd_nand.c correct chip ID found, device available
2792 -56 common/cmd_nand.c Error reading Image Header on boot device
2793 56 common/cmd_nand.c reading Image Header from NAND device OK
2794 -57 common/cmd_nand.c Image header has bad magic number
2795 57 common/cmd_nand.c Image header has correct magic number
2796 -58 common/cmd_nand.c Error reading Image from NAND device
2797 58 common/cmd_nand.c reading Image from NAND device OK
2799 -60 common/env_common.c Environment has a bad CRC, using default
2801 64 net/eth.c starting with Ethernet configuration.
2802 -64 net/eth.c no Ethernet found.
2803 65 net/eth.c Ethernet found.
2805 -80 common/cmd_net.c usage wrong
2806 80 common/cmd_net.c before calling NetLoop()
2807 -81 common/cmd_net.c some error in NetLoop() occurred
2808 81 common/cmd_net.c NetLoop() back without error
2809 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2810 82 common/cmd_net.c trying automatic boot
2811 83 common/cmd_net.c running "source" command
2812 -83 common/cmd_net.c some error in automatic boot or "source" command
2813 84 common/cmd_net.c end without errors
2818 100 common/cmd_bootm.c Kernel FIT Image has correct format
2819 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2820 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2821 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2822 102 common/cmd_bootm.c Kernel unit name specified
2823 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2824 103 common/cmd_bootm.c Found configuration node
2825 104 common/cmd_bootm.c Got kernel subimage node offset
2826 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2827 105 common/cmd_bootm.c Kernel subimage hash verification OK
2828 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2829 106 common/cmd_bootm.c Architecture check OK
2830 -106 common/cmd_bootm.c Kernel subimage has wrong type
2831 107 common/cmd_bootm.c Kernel subimage type OK
2832 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2833 108 common/cmd_bootm.c Got kernel subimage data/size
2834 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2835 -109 common/cmd_bootm.c Can't get kernel subimage type
2836 -110 common/cmd_bootm.c Can't get kernel subimage comp
2837 -111 common/cmd_bootm.c Can't get kernel subimage os
2838 -112 common/cmd_bootm.c Can't get kernel subimage load address
2839 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2841 120 common/image.c Start initial ramdisk verification
2842 -120 common/image.c Ramdisk FIT image has incorrect format
2843 121 common/image.c Ramdisk FIT image has correct format
2844 122 common/image.c No ramdisk subimage unit name, using configuration
2845 -122 common/image.c Can't get configuration for ramdisk subimage
2846 123 common/image.c Ramdisk unit name specified
2847 -124 common/image.c Can't get ramdisk subimage node offset
2848 125 common/image.c Got ramdisk subimage node offset
2849 -125 common/image.c Ramdisk subimage hash verification failed
2850 126 common/image.c Ramdisk subimage hash verification OK
2851 -126 common/image.c Ramdisk subimage for unsupported architecture
2852 127 common/image.c Architecture check OK
2853 -127 common/image.c Can't get ramdisk subimage data/size
2854 128 common/image.c Got ramdisk subimage data/size
2855 129 common/image.c Can't get ramdisk load address
2856 -129 common/image.c Got ramdisk load address
2858 -130 common/cmd_doc.c Incorrect FIT image format
2859 131 common/cmd_doc.c FIT image format OK
2861 -140 common/cmd_ide.c Incorrect FIT image format
2862 141 common/cmd_ide.c FIT image format OK
2864 -150 common/cmd_nand.c Incorrect FIT image format
2865 151 common/cmd_nand.c FIT image format OK
2867 - FIT image support:
2869 Enable support for the FIT uImage format.
2871 CONFIG_FIT_BEST_MATCH
2872 When no configuration is explicitly selected, default to the
2873 one whose fdt's compatibility field best matches that of
2874 U-Boot itself. A match is considered "best" if it matches the
2875 most specific compatibility entry of U-Boot's fdt's root node.
2876 The order of entries in the configuration's fdt is ignored.
2878 CONFIG_FIT_SIGNATURE
2879 This option enables signature verification of FIT uImages,
2880 using a hash signed and verified using RSA. See
2881 doc/uImage.FIT/signature.txt for more details.
2883 - Standalone program support:
2884 CONFIG_STANDALONE_LOAD_ADDR
2886 This option defines a board specific value for the
2887 address where standalone program gets loaded, thus
2888 overwriting the architecture dependent default
2891 - Frame Buffer Address:
2894 Define CONFIG_FB_ADDR if you want to use specific
2895 address for frame buffer. This is typically the case
2896 when using a graphics controller has separate video
2897 memory. U-Boot will then place the frame buffer at
2898 the given address instead of dynamically reserving it
2899 in system RAM by calling lcd_setmem(), which grabs
2900 the memory for the frame buffer depending on the
2901 configured panel size.
2903 Please see board_init_f function.
2905 - Automatic software updates via TFTP server
2907 CONFIG_UPDATE_TFTP_CNT_MAX
2908 CONFIG_UPDATE_TFTP_MSEC_MAX
2910 These options enable and control the auto-update feature;
2911 for a more detailed description refer to doc/README.update.
2913 - MTD Support (mtdparts command, UBI support)
2916 Adds the MTD device infrastructure from the Linux kernel.
2917 Needed for mtdparts command support.
2919 CONFIG_MTD_PARTITIONS
2921 Adds the MTD partitioning infrastructure from the Linux
2922 kernel. Needed for UBI support.
2927 Adds commands for interacting with MTD partitions formatted
2928 with the UBI flash translation layer
2930 Requires also defining CONFIG_RBTREE
2932 CONFIG_UBI_SILENCE_MSG
2934 Make the verbose messages from UBI stop printing. This leaves
2935 warnings and errors enabled.
2940 Adds commands for interacting with UBI volumes formatted as
2941 UBIFS. UBIFS is read-only in u-boot.
2943 Requires UBI support as well as CONFIG_LZO
2945 CONFIG_UBIFS_SILENCE_MSG
2947 Make the verbose messages from UBIFS stop printing. This leaves
2948 warnings and errors enabled.
2952 Enable building of SPL globally.
2955 LDSCRIPT for linking the SPL binary.
2957 CONFIG_SPL_MAX_FOOTPRINT
2958 Maximum size in memory allocated to the SPL, BSS included.
2959 When defined, the linker checks that the actual memory
2960 used by SPL from _start to __bss_end does not exceed it.
2961 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2962 must not be both defined at the same time.
2965 Maximum size of the SPL image (text, data, rodata, and
2966 linker lists sections), BSS excluded.
2967 When defined, the linker checks that the actual size does
2970 CONFIG_SPL_TEXT_BASE
2971 TEXT_BASE for linking the SPL binary.
2973 CONFIG_SPL_RELOC_TEXT_BASE
2974 Address to relocate to. If unspecified, this is equal to
2975 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2977 CONFIG_SPL_BSS_START_ADDR
2978 Link address for the BSS within the SPL binary.
2980 CONFIG_SPL_BSS_MAX_SIZE
2981 Maximum size in memory allocated to the SPL BSS.
2982 When defined, the linker checks that the actual memory used
2983 by SPL from __bss_start to __bss_end does not exceed it.
2984 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2985 must not be both defined at the same time.
2988 Adress of the start of the stack SPL will use
2990 CONFIG_SPL_RELOC_STACK
2991 Adress of the start of the stack SPL will use after
2992 relocation. If unspecified, this is equal to
2995 CONFIG_SYS_SPL_MALLOC_START
2996 Starting address of the malloc pool used in SPL.
2998 CONFIG_SYS_SPL_MALLOC_SIZE
2999 The size of the malloc pool used in SPL.
3001 CONFIG_SPL_FRAMEWORK
3002 Enable the SPL framework under common/. This framework
3003 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3004 NAND loading of the Linux Kernel.
3006 CONFIG_SPL_DISPLAY_PRINT
3007 For ARM, enable an optional function to print more information
3008 about the running system.
3010 CONFIG_SPL_INIT_MINIMAL
3011 Arch init code should be built for a very small image
3013 CONFIG_SPL_LIBCOMMON_SUPPORT
3014 Support for common/libcommon.o in SPL binary
3016 CONFIG_SPL_LIBDISK_SUPPORT
3017 Support for disk/libdisk.o in SPL binary
3019 CONFIG_SPL_I2C_SUPPORT
3020 Support for drivers/i2c/libi2c.o in SPL binary
3022 CONFIG_SPL_GPIO_SUPPORT
3023 Support for drivers/gpio/libgpio.o in SPL binary
3025 CONFIG_SPL_MMC_SUPPORT
3026 Support for drivers/mmc/libmmc.o in SPL binary
3028 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3029 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3030 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3031 Address, size and partition on the MMC to load U-Boot from
3032 when the MMC is being used in raw mode.
3034 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3035 Sector to load kernel uImage from when MMC is being
3036 used in raw mode (for Falcon mode)
3038 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3039 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3040 Sector and number of sectors to load kernel argument
3041 parameters from when MMC is being used in raw mode
3044 CONFIG_SPL_FAT_SUPPORT
3045 Support for fs/fat/libfat.o in SPL binary
3047 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3048 Filename to read to load U-Boot when reading from FAT
3050 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3051 Filename to read to load kernel uImage when reading
3052 from FAT (for Falcon mode)
3054 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3055 Filename to read to load kernel argument parameters
3056 when reading from FAT (for Falcon mode)
3058 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3059 Set this for NAND SPL on PPC mpc83xx targets, so that
3060 start.S waits for the rest of the SPL to load before
3061 continuing (the hardware starts execution after just
3062 loading the first page rather than the full 4K).
3064 CONFIG_SPL_NAND_BASE
3065 Include nand_base.c in the SPL. Requires
3066 CONFIG_SPL_NAND_DRIVERS.
3068 CONFIG_SPL_NAND_DRIVERS
3069 SPL uses normal NAND drivers, not minimal drivers.
3072 Include standard software ECC in the SPL
3074 CONFIG_SPL_NAND_SIMPLE
3075 Support for NAND boot using simple NAND drivers that
3076 expose the cmd_ctrl() interface.
3078 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3079 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3080 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3081 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3082 CONFIG_SYS_NAND_ECCBYTES
3083 Defines the size and behavior of the NAND that SPL uses
3086 CONFIG_SYS_NAND_U_BOOT_OFFS
3087 Location in NAND to read U-Boot from
3089 CONFIG_SYS_NAND_U_BOOT_DST
3090 Location in memory to load U-Boot to
3092 CONFIG_SYS_NAND_U_BOOT_SIZE
3093 Size of image to load
3095 CONFIG_SYS_NAND_U_BOOT_START
3096 Entry point in loaded image to jump to
3098 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3099 Define this if you need to first read the OOB and then the
3100 data. This is used for example on davinci plattforms.
3102 CONFIG_SPL_OMAP3_ID_NAND
3103 Support for an OMAP3-specific set of functions to return the
3104 ID and MFR of the first attached NAND chip, if present.
3106 CONFIG_SPL_SERIAL_SUPPORT
3107 Support for drivers/serial/libserial.o in SPL binary
3109 CONFIG_SPL_SPI_FLASH_SUPPORT
3110 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3112 CONFIG_SPL_SPI_SUPPORT
3113 Support for drivers/spi/libspi.o in SPL binary
3115 CONFIG_SPL_RAM_DEVICE
3116 Support for running image already present in ram, in SPL binary
3118 CONFIG_SPL_LIBGENERIC_SUPPORT
3119 Support for lib/libgeneric.o in SPL binary
3121 CONFIG_SPL_ENV_SUPPORT
3122 Support for the environment operating in SPL binary
3124 CONFIG_SPL_NET_SUPPORT
3125 Support for the net/libnet.o in SPL binary.
3126 It conflicts with SPL env from storage medium specified by
3127 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3130 Image offset to which the SPL should be padded before appending
3131 the SPL payload. By default, this is defined as
3132 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3133 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3134 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3137 Final target image containing SPL and payload. Some SPLs
3138 use an arch-specific makefile fragment instead, for
3139 example if more than one image needs to be produced.
3141 CONFIG_FIT_SPL_PRINT
3142 Printing information about a FIT image adds quite a bit of
3143 code to SPL. So this is normally disabled in SPL. Use this
3144 option to re-enable it. This will affect the output of the
3145 bootm command when booting a FIT image.
3150 [so far only for SMDK2400 boards]
3152 - Modem support enable:
3153 CONFIG_MODEM_SUPPORT
3155 - RTS/CTS Flow control enable:
3158 - Modem debug support:
3159 CONFIG_MODEM_SUPPORT_DEBUG
3161 Enables debugging stuff (char screen[1024], dbg())
3162 for modem support. Useful only with BDI2000.
3164 - Interrupt support (PPC):
3166 There are common interrupt_init() and timer_interrupt()
3167 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3168 for CPU specific initialization. interrupt_init_cpu()
3169 should set decrementer_count to appropriate value. If
3170 CPU resets decrementer automatically after interrupt
3171 (ppc4xx) it should set decrementer_count to zero.
3172 timer_interrupt() calls timer_interrupt_cpu() for CPU
3173 specific handling. If board has watchdog / status_led
3174 / other_activity_monitor it works automatically from
3175 general timer_interrupt().
3179 In the target system modem support is enabled when a
3180 specific key (key combination) is pressed during
3181 power-on. Otherwise U-Boot will boot normally
3182 (autoboot). The key_pressed() function is called from
3183 board_init(). Currently key_pressed() is a dummy
3184 function, returning 1 and thus enabling modem
3187 If there are no modem init strings in the
3188 environment, U-Boot proceed to autoboot; the
3189 previous output (banner, info printfs) will be
3192 See also: doc/README.Modem
3194 Board initialization settings:
3195 ------------------------------
3197 During Initialization u-boot calls a number of board specific functions
3198 to allow the preparation of board specific prerequisites, e.g. pin setup
3199 before drivers are initialized. To enable these callbacks the
3200 following configuration macros have to be defined. Currently this is
3201 architecture specific, so please check arch/your_architecture/lib/board.c
3202 typically in board_init_f() and board_init_r().
3204 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3205 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3206 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3207 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3209 Configuration Settings:
3210 -----------------------
3212 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3213 undefine this when you're short of memory.
3215 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3216 width of the commands listed in the 'help' command output.
3218 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3219 prompt for user input.
3221 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3223 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3225 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3227 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3228 the application (usually a Linux kernel) when it is
3231 - CONFIG_SYS_BAUDRATE_TABLE:
3232 List of legal baudrate settings for this board.
3234 - CONFIG_SYS_CONSOLE_INFO_QUIET
3235 Suppress display of console information at boot.
3237 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3238 If the board specific function
3239 extern int overwrite_console (void);
3240 returns 1, the stdin, stderr and stdout are switched to the
3241 serial port, else the settings in the environment are used.
3243 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3244 Enable the call to overwrite_console().
3246 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3247 Enable overwrite of previous console environment settings.
3249 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3250 Begin and End addresses of the area used by the
3253 - CONFIG_SYS_ALT_MEMTEST:
3254 Enable an alternate, more extensive memory test.
3256 - CONFIG_SYS_MEMTEST_SCRATCH:
3257 Scratch address used by the alternate memory test
3258 You only need to set this if address zero isn't writeable
3260 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3261 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3262 this specified memory area will get subtracted from the top
3263 (end) of RAM and won't get "touched" at all by U-Boot. By
3264 fixing up gd->ram_size the Linux kernel should gets passed
3265 the now "corrected" memory size and won't touch it either.
3266 This should work for arch/ppc and arch/powerpc. Only Linux
3267 board ports in arch/powerpc with bootwrapper support that
3268 recalculate the memory size from the SDRAM controller setup
3269 will have to get fixed in Linux additionally.
3271 This option can be used as a workaround for the 440EPx/GRx
3272 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3275 WARNING: Please make sure that this value is a multiple of
3276 the Linux page size (normally 4k). If this is not the case,
3277 then the end address of the Linux memory will be located at a
3278 non page size aligned address and this could cause major
3281 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3282 Enable temporary baudrate change while serial download
3284 - CONFIG_SYS_SDRAM_BASE:
3285 Physical start address of SDRAM. _Must_ be 0 here.
3287 - CONFIG_SYS_MBIO_BASE:
3288 Physical start address of Motherboard I/O (if using a
3291 - CONFIG_SYS_FLASH_BASE:
3292 Physical start address of Flash memory.
3294 - CONFIG_SYS_MONITOR_BASE:
3295 Physical start address of boot monitor code (set by
3296 make config files to be same as the text base address
3297 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3298 CONFIG_SYS_FLASH_BASE when booting from flash.
3300 - CONFIG_SYS_MONITOR_LEN:
3301 Size of memory reserved for monitor code, used to
3302 determine _at_compile_time_ (!) if the environment is
3303 embedded within the U-Boot image, or in a separate
3306 - CONFIG_SYS_MALLOC_LEN:
3307 Size of DRAM reserved for malloc() use.
3309 - CONFIG_SYS_BOOTM_LEN:
3310 Normally compressed uImages are limited to an
3311 uncompressed size of 8 MBytes. If this is not enough,
3312 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3313 to adjust this setting to your needs.
3315 - CONFIG_SYS_BOOTMAPSZ:
3316 Maximum size of memory mapped by the startup code of
3317 the Linux kernel; all data that must be processed by
3318 the Linux kernel (bd_info, boot arguments, FDT blob if
3319 used) must be put below this limit, unless "bootm_low"
3320 enviroment variable is defined and non-zero. In such case
3321 all data for the Linux kernel must be between "bootm_low"
3322 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3323 variable "bootm_mapsize" will override the value of
3324 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3325 then the value in "bootm_size" will be used instead.
3327 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3328 Enable initrd_high functionality. If defined then the
3329 initrd_high feature is enabled and the bootm ramdisk subcommand
3332 - CONFIG_SYS_BOOT_GET_CMDLINE:
3333 Enables allocating and saving kernel cmdline in space between
3334 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3336 - CONFIG_SYS_BOOT_GET_KBD:
3337 Enables allocating and saving a kernel copy of the bd_info in
3338 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3340 - CONFIG_SYS_MAX_FLASH_BANKS:
3341 Max number of Flash memory banks
3343 - CONFIG_SYS_MAX_FLASH_SECT:
3344 Max number of sectors on a Flash chip
3346 - CONFIG_SYS_FLASH_ERASE_TOUT:
3347 Timeout for Flash erase operations (in ms)
3349 - CONFIG_SYS_FLASH_WRITE_TOUT:
3350 Timeout for Flash write operations (in ms)
3352 - CONFIG_SYS_FLASH_LOCK_TOUT
3353 Timeout for Flash set sector lock bit operation (in ms)
3355 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3356 Timeout for Flash clear lock bits operation (in ms)
3358 - CONFIG_SYS_FLASH_PROTECTION
3359 If defined, hardware flash sectors protection is used
3360 instead of U-Boot software protection.
3362 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3364 Enable TFTP transfers directly to flash memory;
3365 without this option such a download has to be
3366 performed in two steps: (1) download to RAM, and (2)
3367 copy from RAM to flash.
3369 The two-step approach is usually more reliable, since
3370 you can check if the download worked before you erase
3371 the flash, but in some situations (when system RAM is
3372 too limited to allow for a temporary copy of the
3373 downloaded image) this option may be very useful.
3375 - CONFIG_SYS_FLASH_CFI:
3376 Define if the flash driver uses extra elements in the
3377 common flash structure for storing flash geometry.
3379 - CONFIG_FLASH_CFI_DRIVER
3380 This option also enables the building of the cfi_flash driver
3381 in the drivers directory
3383 - CONFIG_FLASH_CFI_MTD
3384 This option enables the building of the cfi_mtd driver
3385 in the drivers directory. The driver exports CFI flash
3388 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3389 Use buffered writes to flash.
3391 - CONFIG_FLASH_SPANSION_S29WS_N
3392 s29ws-n MirrorBit flash has non-standard addresses for buffered
3395 - CONFIG_SYS_FLASH_QUIET_TEST
3396 If this option is defined, the common CFI flash doesn't
3397 print it's warning upon not recognized FLASH banks. This
3398 is useful, if some of the configured banks are only
3399 optionally available.
3401 - CONFIG_FLASH_SHOW_PROGRESS
3402 If defined (must be an integer), print out countdown
3403 digits and dots. Recommended value: 45 (9..1) for 80
3404 column displays, 15 (3..1) for 40 column displays.
3406 - CONFIG_FLASH_VERIFY
3407 If defined, the content of the flash (destination) is compared
3408 against the source after the write operation. An error message
3409 will be printed when the contents are not identical.
3410 Please note that this option is useless in nearly all cases,
3411 since such flash programming errors usually are detected earlier
3412 while unprotecting/erasing/programming. Please only enable
3413 this option if you really know what you are doing.
3415 - CONFIG_SYS_RX_ETH_BUFFER:
3416 Defines the number of Ethernet receive buffers. On some
3417 Ethernet controllers it is recommended to set this value
3418 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3419 buffers can be full shortly after enabling the interface
3420 on high Ethernet traffic.
3421 Defaults to 4 if not defined.
3423 - CONFIG_ENV_MAX_ENTRIES
3425 Maximum number of entries in the hash table that is used
3426 internally to store the environment settings. The default
3427 setting is supposed to be generous and should work in most
3428 cases. This setting can be used to tune behaviour; see
3429 lib/hashtable.c for details.
3431 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3432 - CONFIG_ENV_FLAGS_LIST_STATIC
3433 Enable validation of the values given to enviroment variables when
3434 calling env set. Variables can be restricted to only decimal,
3435 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3436 the variables can also be restricted to IP address or MAC address.
3438 The format of the list is:
3439 type_attribute = [s|d|x|b|i|m]
3440 access_atribute = [a|r|o|c]
3441 attributes = type_attribute[access_atribute]
3442 entry = variable_name[:attributes]
3445 The type attributes are:
3446 s - String (default)
3449 b - Boolean ([1yYtT|0nNfF])
3453 The access attributes are:
3459 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3460 Define this to a list (string) to define the ".flags"
3461 envirnoment variable in the default or embedded environment.
3463 - CONFIG_ENV_FLAGS_LIST_STATIC
3464 Define this to a list (string) to define validation that
3465 should be done if an entry is not found in the ".flags"
3466 environment variable. To override a setting in the static
3467 list, simply add an entry for the same variable name to the
3470 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3471 If defined, don't allow the -f switch to env set override variable
3474 - CONFIG_SYS_GENERIC_BOARD
3475 This selects the architecture-generic board system instead of the
3476 architecture-specific board files. It is intended to move boards
3477 to this new framework over time. Defining this will disable the
3478 arch/foo/lib/board.c file and use common/board_f.c and
3479 common/board_r.c instead. To use this option your architecture
3480 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3481 its config.mk file). If you find problems enabling this option on
3482 your board please report the problem and send patches!
3484 - CONFIG_SYS_SYM_OFFSETS
3485 This is set by architectures that use offsets for link symbols
3486 instead of absolute values. So bss_start is obtained using an
3487 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3488 directly. You should not need to touch this setting.
3490 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3491 This is set by OMAP boards for the max time that reset should
3492 be asserted. See doc/README.omap-reset-time for details on how
3493 the value can be calulated on a given board.
3495 The following definitions that deal with the placement and management
3496 of environment data (variable area); in general, we support the
3497 following configurations:
3499 - CONFIG_BUILD_ENVCRC:
3501 Builds up envcrc with the target environment so that external utils
3502 may easily extract it and embed it in final U-Boot images.
3504 - CONFIG_ENV_IS_IN_FLASH:
3506 Define this if the environment is in flash memory.
3508 a) The environment occupies one whole flash sector, which is
3509 "embedded" in the text segment with the U-Boot code. This
3510 happens usually with "bottom boot sector" or "top boot
3511 sector" type flash chips, which have several smaller
3512 sectors at the start or the end. For instance, such a
3513 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3514 such a case you would place the environment in one of the
3515 4 kB sectors - with U-Boot code before and after it. With
3516 "top boot sector" type flash chips, you would put the
3517 environment in one of the last sectors, leaving a gap
3518 between U-Boot and the environment.
3520 - CONFIG_ENV_OFFSET:
3522 Offset of environment data (variable area) to the
3523 beginning of flash memory; for instance, with bottom boot
3524 type flash chips the second sector can be used: the offset
3525 for this sector is given here.
3527 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3531 This is just another way to specify the start address of
3532 the flash sector containing the environment (instead of
3535 - CONFIG_ENV_SECT_SIZE:
3537 Size of the sector containing the environment.
3540 b) Sometimes flash chips have few, equal sized, BIG sectors.
3541 In such a case you don't want to spend a whole sector for
3546 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3547 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3548 of this flash sector for the environment. This saves
3549 memory for the RAM copy of the environment.
3551 It may also save flash memory if you decide to use this
3552 when your environment is "embedded" within U-Boot code,
3553 since then the remainder of the flash sector could be used
3554 for U-Boot code. It should be pointed out that this is
3555 STRONGLY DISCOURAGED from a robustness point of view:
3556 updating the environment in flash makes it always
3557 necessary to erase the WHOLE sector. If something goes
3558 wrong before the contents has been restored from a copy in
3559 RAM, your target system will be dead.
3561 - CONFIG_ENV_ADDR_REDUND
3562 CONFIG_ENV_SIZE_REDUND
3564 These settings describe a second storage area used to hold
3565 a redundant copy of the environment data, so that there is
3566 a valid backup copy in case there is a power failure during
3567 a "saveenv" operation.
3569 BE CAREFUL! Any changes to the flash layout, and some changes to the
3570 source code will make it necessary to adapt <board>/u-boot.lds*
3574 - CONFIG_ENV_IS_IN_NVRAM:
3576 Define this if you have some non-volatile memory device
3577 (NVRAM, battery buffered SRAM) which you want to use for the
3583 These two #defines are used to determine the memory area you
3584 want to use for environment. It is assumed that this memory
3585 can just be read and written to, without any special
3588 BE CAREFUL! The first access to the environment happens quite early
3589 in U-Boot initalization (when we try to get the setting of for the
3590 console baudrate). You *MUST* have mapped your NVRAM area then, or
3593 Please note that even with NVRAM we still use a copy of the
3594 environment in RAM: we could work on NVRAM directly, but we want to
3595 keep settings there always unmodified except somebody uses "saveenv"
3596 to save the current settings.
3599 - CONFIG_ENV_IS_IN_EEPROM:
3601 Use this if you have an EEPROM or similar serial access
3602 device and a driver for it.
3604 - CONFIG_ENV_OFFSET:
3607 These two #defines specify the offset and size of the
3608 environment area within the total memory of your EEPROM.
3610 - CONFIG_SYS_I2C_EEPROM_ADDR:
3611 If defined, specified the chip address of the EEPROM device.
3612 The default address is zero.
3614 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3615 If defined, the number of bits used to address bytes in a
3616 single page in the EEPROM device. A 64 byte page, for example
3617 would require six bits.
3619 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3620 If defined, the number of milliseconds to delay between
3621 page writes. The default is zero milliseconds.
3623 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3624 The length in bytes of the EEPROM memory array address. Note
3625 that this is NOT the chip address length!
3627 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3628 EEPROM chips that implement "address overflow" are ones
3629 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3630 address and the extra bits end up in the "chip address" bit
3631 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3634 Note that we consider the length of the address field to
3635 still be one byte because the extra address bits are hidden
3636 in the chip address.
3638 - CONFIG_SYS_EEPROM_SIZE:
3639 The size in bytes of the EEPROM device.
3641 - CONFIG_ENV_EEPROM_IS_ON_I2C
3642 define this, if you have I2C and SPI activated, and your
3643 EEPROM, which holds the environment, is on the I2C bus.
3645 - CONFIG_I2C_ENV_EEPROM_BUS
3646 if you have an Environment on an EEPROM reached over
3647 I2C muxes, you can define here, how to reach this
3648 EEPROM. For example:
3650 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3652 EEPROM which holds the environment, is reached over
3653 a pca9547 i2c mux with address 0x70, channel 3.
3655 - CONFIG_ENV_IS_IN_DATAFLASH:
3657 Define this if you have a DataFlash memory device which you
3658 want to use for the environment.
3660 - CONFIG_ENV_OFFSET:
3664 These three #defines specify the offset and size of the
3665 environment area within the total memory of your DataFlash placed
3666 at the specified address.
3668 - CONFIG_ENV_IS_IN_REMOTE:
3670 Define this if you have a remote memory space which you
3671 want to use for the local device's environment.
3676 These two #defines specify the address and size of the
3677 environment area within the remote memory space. The
3678 local device can get the environment from remote memory
3679 space by SRIO or PCIE links.
3681 BE CAREFUL! For some special cases, the local device can not use
3682 "saveenv" command. For example, the local device will get the
3683 environment stored in a remote NOR flash by SRIO or PCIE link,
3684 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3686 - CONFIG_ENV_IS_IN_NAND:
3688 Define this if you have a NAND device which you want to use
3689 for the environment.
3691 - CONFIG_ENV_OFFSET:
3694 These two #defines specify the offset and size of the environment
3695 area within the first NAND device. CONFIG_ENV_OFFSET must be
3696 aligned to an erase block boundary.
3698 - CONFIG_ENV_OFFSET_REDUND (optional):
3700 This setting describes a second storage area of CONFIG_ENV_SIZE
3701 size used to hold a redundant copy of the environment data, so
3702 that there is a valid backup copy in case there is a power failure
3703 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3704 aligned to an erase block boundary.
3706 - CONFIG_ENV_RANGE (optional):
3708 Specifies the length of the region in which the environment
3709 can be written. This should be a multiple of the NAND device's
3710 block size. Specifying a range with more erase blocks than
3711 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3712 the range to be avoided.
3714 - CONFIG_ENV_OFFSET_OOB (optional):
3716 Enables support for dynamically retrieving the offset of the
3717 environment from block zero's out-of-band data. The
3718 "nand env.oob" command can be used to record this offset.
3719 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3720 using CONFIG_ENV_OFFSET_OOB.
3722 - CONFIG_NAND_ENV_DST
3724 Defines address in RAM to which the nand_spl code should copy the
3725 environment. If redundant environment is used, it will be copied to
3726 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3728 - CONFIG_ENV_IS_IN_UBI:
3730 Define this if you have an UBI volume that you want to use for the
3731 environment. This has the benefit of wear-leveling the environment
3732 accesses, which is important on NAND.
3734 - CONFIG_ENV_UBI_PART:
3736 Define this to a string that is the mtd partition containing the UBI.
3738 - CONFIG_ENV_UBI_VOLUME:
3740 Define this to the name of the volume that you want to store the
3743 - CONFIG_ENV_UBI_VOLUME_REDUND:
3745 Define this to the name of another volume to store a second copy of
3746 the environment in. This will enable redundant environments in UBI.
3747 It is assumed that both volumes are in the same MTD partition.
3749 - CONFIG_UBI_SILENCE_MSG
3750 - CONFIG_UBIFS_SILENCE_MSG
3752 You will probably want to define these to avoid a really noisy system
3753 when storing the env in UBI.
3755 - CONFIG_ENV_IS_IN_MMC:
3757 Define this if you have an MMC device which you want to use for the
3760 - CONFIG_SYS_MMC_ENV_DEV:
3762 Specifies which MMC device the environment is stored in.
3764 - CONFIG_SYS_MMC_ENV_PART (optional):
3766 Specifies which MMC partition the environment is stored in. If not
3767 set, defaults to partition 0, the user area. Common values might be
3768 1 (first MMC boot partition), 2 (second MMC boot partition).
3770 - CONFIG_ENV_OFFSET:
3773 These two #defines specify the offset and size of the environment
3774 area within the specified MMC device.
3776 If offset is positive (the usual case), it is treated as relative to
3777 the start of the MMC partition. If offset is negative, it is treated
3778 as relative to the end of the MMC partition. This can be useful if
3779 your board may be fitted with different MMC devices, which have
3780 different sizes for the MMC partitions, and you always want the
3781 environment placed at the very end of the partition, to leave the
3782 maximum possible space before it, to store other data.
3784 These two values are in units of bytes, but must be aligned to an
3785 MMC sector boundary.
3787 - CONFIG_ENV_OFFSET_REDUND (optional):
3789 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3790 hold a redundant copy of the environment data. This provides a
3791 valid backup copy in case the other copy is corrupted, e.g. due
3792 to a power failure during a "saveenv" operation.
3794 This value may also be positive or negative; this is handled in the
3795 same way as CONFIG_ENV_OFFSET.
3797 This value is also in units of bytes, but must also be aligned to
3798 an MMC sector boundary.
3800 - CONFIG_ENV_SIZE_REDUND (optional):
3802 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3803 set. If this value is set, it must be set to the same value as
3806 - CONFIG_SYS_SPI_INIT_OFFSET
3808 Defines offset to the initial SPI buffer area in DPRAM. The
3809 area is used at an early stage (ROM part) if the environment
3810 is configured to reside in the SPI EEPROM: We need a 520 byte
3811 scratch DPRAM area. It is used between the two initialization
3812 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3813 to be a good choice since it makes it far enough from the
3814 start of the data area as well as from the stack pointer.
3816 Please note that the environment is read-only until the monitor
3817 has been relocated to RAM and a RAM copy of the environment has been
3818 created; also, when using EEPROM you will have to use getenv_f()
3819 until then to read environment variables.
3821 The environment is protected by a CRC32 checksum. Before the monitor
3822 is relocated into RAM, as a result of a bad CRC you will be working
3823 with the compiled-in default environment - *silently*!!! [This is
3824 necessary, because the first environment variable we need is the
3825 "baudrate" setting for the console - if we have a bad CRC, we don't
3826 have any device yet where we could complain.]
3828 Note: once the monitor has been relocated, then it will complain if
3829 the default environment is used; a new CRC is computed as soon as you
3830 use the "saveenv" command to store a valid environment.
3832 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3833 Echo the inverted Ethernet link state to the fault LED.
3835 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3836 also needs to be defined.
3838 - CONFIG_SYS_FAULT_MII_ADDR:
3839 MII address of the PHY to check for the Ethernet link state.
3841 - CONFIG_NS16550_MIN_FUNCTIONS:
3842 Define this if you desire to only have use of the NS16550_init
3843 and NS16550_putc functions for the serial driver located at
3844 drivers/serial/ns16550.c. This option is useful for saving
3845 space for already greatly restricted images, including but not
3846 limited to NAND_SPL configurations.
3848 - CONFIG_DISPLAY_BOARDINFO
3849 Display information about the board that U-Boot is running on
3850 when U-Boot starts up. The board function checkboard() is called
3853 - CONFIG_DISPLAY_BOARDINFO_LATE
3854 Similar to the previous option, but display this information
3855 later, once stdio is running and output goes to the LCD, if
3858 Low Level (hardware related) configuration options:
3859 ---------------------------------------------------
3861 - CONFIG_SYS_CACHELINE_SIZE:
3862 Cache Line Size of the CPU.
3864 - CONFIG_SYS_DEFAULT_IMMR:
3865 Default address of the IMMR after system reset.
3867 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3868 and RPXsuper) to be able to adjust the position of
3869 the IMMR register after a reset.
3871 - CONFIG_SYS_CCSRBAR_DEFAULT:
3872 Default (power-on reset) physical address of CCSR on Freescale
3875 - CONFIG_SYS_CCSRBAR:
3876 Virtual address of CCSR. On a 32-bit build, this is typically
3877 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3879 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3880 for cross-platform code that uses that macro instead.
3882 - CONFIG_SYS_CCSRBAR_PHYS:
3883 Physical address of CCSR. CCSR can be relocated to a new
3884 physical address, if desired. In this case, this macro should
3885 be set to that address. Otherwise, it should be set to the
3886 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3887 is typically relocated on 36-bit builds. It is recommended
3888 that this macro be defined via the _HIGH and _LOW macros:
3890 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3891 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3893 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3894 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3895 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3896 used in assembly code, so it must not contain typecasts or
3897 integer size suffixes (e.g. "ULL").
3899 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3900 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3901 used in assembly code, so it must not contain typecasts or
3902 integer size suffixes (e.g. "ULL").
3904 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3905 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3906 forced to a value that ensures that CCSR is not relocated.
3908 - Floppy Disk Support:
3909 CONFIG_SYS_FDC_DRIVE_NUMBER
3911 the default drive number (default value 0)
3913 CONFIG_SYS_ISA_IO_STRIDE
3915 defines the spacing between FDC chipset registers
3918 CONFIG_SYS_ISA_IO_OFFSET
3920 defines the offset of register from address. It
3921 depends on which part of the data bus is connected to
3922 the FDC chipset. (default value 0)
3924 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3925 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3928 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3929 fdc_hw_init() is called at the beginning of the FDC
3930 setup. fdc_hw_init() must be provided by the board
3931 source code. It is used to make hardware dependant
3935 Most IDE controllers were designed to be connected with PCI
3936 interface. Only few of them were designed for AHB interface.
3937 When software is doing ATA command and data transfer to
3938 IDE devices through IDE-AHB controller, some additional
3939 registers accessing to these kind of IDE-AHB controller
3942 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3943 DO NOT CHANGE unless you know exactly what you're
3944 doing! (11-4) [MPC8xx/82xx systems only]
3946 - CONFIG_SYS_INIT_RAM_ADDR:
3948 Start address of memory area that can be used for
3949 initial data and stack; please note that this must be
3950 writable memory that is working WITHOUT special
3951 initialization, i. e. you CANNOT use normal RAM which
3952 will become available only after programming the
3953 memory controller and running certain initialization
3956 U-Boot uses the following memory types:
3957 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3958 - MPC824X: data cache
3959 - PPC4xx: data cache
3961 - CONFIG_SYS_GBL_DATA_OFFSET:
3963 Offset of the initial data structure in the memory
3964 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3965 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3966 data is located at the end of the available space
3967 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3968 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3969 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3970 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3973 On the MPC824X (or other systems that use the data
3974 cache for initial memory) the address chosen for
3975 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3976 point to an otherwise UNUSED address space between
3977 the top of RAM and the start of the PCI space.
3979 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3981 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3983 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3985 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3987 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3989 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3991 - CONFIG_SYS_OR_TIMING_SDRAM:
3994 - CONFIG_SYS_MAMR_PTA:
3995 periodic timer for refresh
3997 - CONFIG_SYS_DER: Debug Event Register (37-47)
3999 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4000 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4001 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4002 CONFIG_SYS_BR1_PRELIM:
4003 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4005 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4006 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4007 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4008 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4010 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4011 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4012 Machine Mode Register and Memory Periodic Timer
4013 Prescaler definitions (SDRAM timing)
4015 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4016 enable I2C microcode relocation patch (MPC8xx);
4017 define relocation offset in DPRAM [DSP2]
4019 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4020 enable SMC microcode relocation patch (MPC8xx);
4021 define relocation offset in DPRAM [SMC1]
4023 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4024 enable SPI microcode relocation patch (MPC8xx);
4025 define relocation offset in DPRAM [SCC4]
4027 - CONFIG_SYS_USE_OSCCLK:
4028 Use OSCM clock mode on MBX8xx board. Be careful,
4029 wrong setting might damage your board. Read
4030 doc/README.MBX before setting this variable!
4032 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4033 Offset of the bootmode word in DPRAM used by post
4034 (Power On Self Tests). This definition overrides
4035 #define'd default value in commproc.h resp.
4038 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4039 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4040 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4041 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4042 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4043 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4044 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4045 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4046 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4048 - CONFIG_PCI_DISABLE_PCIE:
4049 Disable PCI-Express on systems where it is supported but not
4052 - CONFIG_PCI_ENUM_ONLY
4053 Only scan through and get the devices on the busses.
4054 Don't do any setup work, presumably because someone or
4055 something has already done it, and we don't need to do it
4056 a second time. Useful for platforms that are pre-booted
4057 by coreboot or similar.
4059 - CONFIG_PCI_INDIRECT_BRIDGE:
4060 Enable support for indirect PCI bridges.
4063 Chip has SRIO or not
4066 Board has SRIO 1 port available
4069 Board has SRIO 2 port available
4071 - CONFIG_SRIO_PCIE_BOOT_MASTER
4072 Board can support master function for Boot from SRIO and PCIE
4074 - CONFIG_SYS_SRIOn_MEM_VIRT:
4075 Virtual Address of SRIO port 'n' memory region
4077 - CONFIG_SYS_SRIOn_MEM_PHYS:
4078 Physical Address of SRIO port 'n' memory region
4080 - CONFIG_SYS_SRIOn_MEM_SIZE:
4081 Size of SRIO port 'n' memory region
4083 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4084 Defined to tell the NAND controller that the NAND chip is using
4086 Not all NAND drivers use this symbol.
4087 Example of drivers that use it:
4088 - drivers/mtd/nand/ndfc.c
4089 - drivers/mtd/nand/mxc_nand.c
4091 - CONFIG_SYS_NDFC_EBC0_CFG
4092 Sets the EBC0_CFG register for the NDFC. If not defined
4093 a default value will be used.
4096 Get DDR timing information from an I2C EEPROM. Common
4097 with pluggable memory modules such as SODIMMs
4100 I2C address of the SPD EEPROM
4102 - CONFIG_SYS_SPD_BUS_NUM
4103 If SPD EEPROM is on an I2C bus other than the first
4104 one, specify here. Note that the value must resolve
4105 to something your driver can deal with.
4107 - CONFIG_SYS_DDR_RAW_TIMING
4108 Get DDR timing information from other than SPD. Common with
4109 soldered DDR chips onboard without SPD. DDR raw timing
4110 parameters are extracted from datasheet and hard-coded into
4111 header files or board specific files.
4113 - CONFIG_FSL_DDR_INTERACTIVE
4114 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4116 - CONFIG_SYS_83XX_DDR_USES_CS0
4117 Only for 83xx systems. If specified, then DDR should
4118 be configured using CS0 and CS1 instead of CS2 and CS3.
4120 - CONFIG_ETHER_ON_FEC[12]
4121 Define to enable FEC[12] on a 8xx series processor.
4123 - CONFIG_FEC[12]_PHY
4124 Define to the hardcoded PHY address which corresponds
4125 to the given FEC; i. e.
4126 #define CONFIG_FEC1_PHY 4
4127 means that the PHY with address 4 is connected to FEC1
4129 When set to -1, means to probe for first available.
4131 - CONFIG_FEC[12]_PHY_NORXERR
4132 The PHY does not have a RXERR line (RMII only).
4133 (so program the FEC to ignore it).
4136 Enable RMII mode for all FECs.
4137 Note that this is a global option, we can't
4138 have one FEC in standard MII mode and another in RMII mode.
4140 - CONFIG_CRC32_VERIFY
4141 Add a verify option to the crc32 command.
4144 => crc32 -v <address> <count> <crc32>
4146 Where address/count indicate a memory area
4147 and crc32 is the correct crc32 which the
4151 Add the "loopw" memory command. This only takes effect if
4152 the memory commands are activated globally (CONFIG_CMD_MEM).
4155 Add the "mdc" and "mwc" memory commands. These are cyclic
4160 This command will print 4 bytes (10,11,12,13) each 500 ms.
4162 => mwc.l 100 12345678 10
4163 This command will write 12345678 to address 100 all 10 ms.
4165 This only takes effect if the memory commands are activated
4166 globally (CONFIG_CMD_MEM).
4168 - CONFIG_SKIP_LOWLEVEL_INIT
4169 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4170 low level initializations (like setting up the memory
4171 controller) are omitted and/or U-Boot does not
4172 relocate itself into RAM.
4174 Normally this variable MUST NOT be defined. The only
4175 exception is when U-Boot is loaded (to RAM) by some
4176 other boot loader or by a debugger which performs
4177 these initializations itself.
4180 Modifies the behaviour of start.S when compiling a loader
4181 that is executed before the actual U-Boot. E.g. when
4182 compiling a NAND SPL.
4184 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4185 Only for 85xx systems. If this variable is specified, the section
4186 .resetvec is not kept and the section .bootpg is placed in the
4187 previous 4k of the .text section.
4189 - CONFIG_ARCH_MAP_SYSMEM
4190 Generally U-Boot (and in particular the md command) uses
4191 effective address. It is therefore not necessary to regard
4192 U-Boot address as virtual addresses that need to be translated
4193 to physical addresses. However, sandbox requires this, since
4194 it maintains its own little RAM buffer which contains all
4195 addressable memory. This option causes some memory accesses
4196 to be mapped through map_sysmem() / unmap_sysmem().
4198 - CONFIG_USE_ARCH_MEMCPY
4199 CONFIG_USE_ARCH_MEMSET
4200 If these options are used a optimized version of memcpy/memset will
4201 be used if available. These functions may be faster under some
4202 conditions but may increase the binary size.
4204 - CONFIG_X86_RESET_VECTOR
4205 If defined, the x86 reset vector code is included. This is not
4206 needed when U-Boot is running from Coreboot.
4209 Defines the MPU clock speed (in MHz).
4211 NOTE : currently only supported on AM335x platforms.
4213 Freescale QE/FMAN Firmware Support:
4214 -----------------------------------
4216 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4217 loading of "firmware", which is encoded in the QE firmware binary format.
4218 This firmware often needs to be loaded during U-Boot booting, so macros
4219 are used to identify the storage device (NOR flash, SPI, etc) and the address
4222 - CONFIG_SYS_QE_FMAN_FW_ADDR
4223 The address in the storage device where the firmware is located. The
4224 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4227 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4228 The maximum possible size of the firmware. The firmware binary format
4229 has a field that specifies the actual size of the firmware, but it
4230 might not be possible to read any part of the firmware unless some
4231 local storage is allocated to hold the entire firmware first.
4233 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4234 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4235 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4236 virtual address in NOR flash.
4238 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4239 Specifies that QE/FMAN firmware is located in NAND flash.
4240 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4242 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4243 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4244 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4246 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4247 Specifies that QE/FMAN firmware is located on the primary SPI
4248 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4250 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4251 Specifies that QE/FMAN firmware is located in the remote (master)
4252 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4253 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4254 window->master inbound window->master LAW->the ucode address in
4255 master's memory space.
4257 Building the Software:
4258 ======================
4260 Building U-Boot has been tested in several native build environments
4261 and in many different cross environments. Of course we cannot support
4262 all possibly existing versions of cross development tools in all
4263 (potentially obsolete) versions. In case of tool chain problems we
4264 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4265 which is extensively used to build and test U-Boot.
4267 If you are not using a native environment, it is assumed that you
4268 have GNU cross compiling tools available in your path. In this case,
4269 you must set the environment variable CROSS_COMPILE in your shell.
4270 Note that no changes to the Makefile or any other source files are
4271 necessary. For example using the ELDK on a 4xx CPU, please enter:
4273 $ CROSS_COMPILE=ppc_4xx-
4274 $ export CROSS_COMPILE
4276 Note: If you wish to generate Windows versions of the utilities in
4277 the tools directory you can use the MinGW toolchain
4278 (http://www.mingw.org). Set your HOST tools to the MinGW
4279 toolchain and execute 'make tools'. For example:
4281 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4283 Binaries such as tools/mkimage.exe will be created which can
4284 be executed on computers running Windows.
4286 U-Boot is intended to be simple to build. After installing the
4287 sources you must configure U-Boot for one specific board type. This
4292 where "NAME_config" is the name of one of the existing configu-
4293 rations; see boards.cfg for supported names.
4295 Note: for some board special configuration names may exist; check if
4296 additional information is available from the board vendor; for
4297 instance, the TQM823L systems are available without (standard)
4298 or with LCD support. You can select such additional "features"
4299 when choosing the configuration, i. e.
4302 - will configure for a plain TQM823L, i. e. no LCD support
4304 make TQM823L_LCD_config
4305 - will configure for a TQM823L with U-Boot console on LCD
4310 Finally, type "make all", and you should get some working U-Boot
4311 images ready for download to / installation on your system:
4313 - "u-boot.bin" is a raw binary image
4314 - "u-boot" is an image in ELF binary format
4315 - "u-boot.srec" is in Motorola S-Record format
4317 By default the build is performed locally and the objects are saved
4318 in the source directory. One of the two methods can be used to change
4319 this behavior and build U-Boot to some external directory:
4321 1. Add O= to the make command line invocations:
4323 make O=/tmp/build distclean
4324 make O=/tmp/build NAME_config
4325 make O=/tmp/build all
4327 2. Set environment variable BUILD_DIR to point to the desired location:
4329 export BUILD_DIR=/tmp/build
4334 Note that the command line "O=" setting overrides the BUILD_DIR environment
4338 Please be aware that the Makefiles assume you are using GNU make, so
4339 for instance on NetBSD you might need to use "gmake" instead of
4343 If the system board that you have is not listed, then you will need
4344 to port U-Boot to your hardware platform. To do this, follow these
4347 1. Add a new configuration option for your board to the toplevel
4348 "boards.cfg" file, using the existing entries as examples.
4349 Follow the instructions there to keep the boards in order.
4350 2. Create a new directory to hold your board specific code. Add any
4351 files you need. In your board directory, you will need at least
4352 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4353 3. Create a new configuration file "include/configs/<board>.h" for
4355 3. If you're porting U-Boot to a new CPU, then also create a new
4356 directory to hold your CPU specific code. Add any files you need.
4357 4. Run "make <board>_config" with your new name.
4358 5. Type "make", and you should get a working "u-boot.srec" file
4359 to be installed on your target system.
4360 6. Debug and solve any problems that might arise.
4361 [Of course, this last step is much harder than it sounds.]
4364 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4365 ==============================================================
4367 If you have modified U-Boot sources (for instance added a new board
4368 or support for new devices, a new CPU, etc.) you are expected to
4369 provide feedback to the other developers. The feedback normally takes
4370 the form of a "patch", i. e. a context diff against a certain (latest
4371 official or latest in the git repository) version of U-Boot sources.
4373 But before you submit such a patch, please verify that your modifi-
4374 cation did not break existing code. At least make sure that *ALL* of
4375 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4376 just run the "MAKEALL" script, which will configure and build U-Boot
4377 for ALL supported system. Be warned, this will take a while. You can
4378 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4379 environment variable to the script, i. e. to use the ELDK cross tools
4382 CROSS_COMPILE=ppc_8xx- MAKEALL
4384 or to build on a native PowerPC system you can type
4386 CROSS_COMPILE=' ' MAKEALL
4388 When using the MAKEALL script, the default behaviour is to build
4389 U-Boot in the source directory. This location can be changed by
4390 setting the BUILD_DIR environment variable. Also, for each target
4391 built, the MAKEALL script saves two log files (<target>.ERR and
4392 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4393 location can be changed by setting the MAKEALL_LOGDIR environment
4394 variable. For example:
4396 export BUILD_DIR=/tmp/build
4397 export MAKEALL_LOGDIR=/tmp/log
4398 CROSS_COMPILE=ppc_8xx- MAKEALL
4400 With the above settings build objects are saved in the /tmp/build,
4401 log files are saved in the /tmp/log and the source tree remains clean
4402 during the whole build process.
4405 See also "U-Boot Porting Guide" below.
4408 Monitor Commands - Overview:
4409 ============================
4411 go - start application at address 'addr'
4412 run - run commands in an environment variable
4413 bootm - boot application image from memory
4414 bootp - boot image via network using BootP/TFTP protocol
4415 bootz - boot zImage from memory
4416 tftpboot- boot image via network using TFTP protocol
4417 and env variables "ipaddr" and "serverip"
4418 (and eventually "gatewayip")
4419 tftpput - upload a file via network using TFTP protocol
4420 rarpboot- boot image via network using RARP/TFTP protocol
4421 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4422 loads - load S-Record file over serial line
4423 loadb - load binary file over serial line (kermit mode)
4425 mm - memory modify (auto-incrementing)
4426 nm - memory modify (constant address)
4427 mw - memory write (fill)
4429 cmp - memory compare
4430 crc32 - checksum calculation
4431 i2c - I2C sub-system
4432 sspi - SPI utility commands
4433 base - print or set address offset
4434 printenv- print environment variables
4435 setenv - set environment variables
4436 saveenv - save environment variables to persistent storage
4437 protect - enable or disable FLASH write protection
4438 erase - erase FLASH memory
4439 flinfo - print FLASH memory information
4440 nand - NAND memory operations (see doc/README.nand)
4441 bdinfo - print Board Info structure
4442 iminfo - print header information for application image
4443 coninfo - print console devices and informations
4444 ide - IDE sub-system
4445 loop - infinite loop on address range
4446 loopw - infinite write loop on address range
4447 mtest - simple RAM test
4448 icache - enable or disable instruction cache
4449 dcache - enable or disable data cache
4450 reset - Perform RESET of the CPU
4451 echo - echo args to console
4452 version - print monitor version
4453 help - print online help
4454 ? - alias for 'help'
4457 Monitor Commands - Detailed Description:
4458 ========================================
4462 For now: just type "help <command>".
4465 Environment Variables:
4466 ======================
4468 U-Boot supports user configuration using Environment Variables which
4469 can be made persistent by saving to Flash memory.
4471 Environment Variables are set using "setenv", printed using
4472 "printenv", and saved to Flash using "saveenv". Using "setenv"
4473 without a value can be used to delete a variable from the
4474 environment. As long as you don't save the environment you are
4475 working with an in-memory copy. In case the Flash area containing the
4476 environment is erased by accident, a default environment is provided.
4478 Some configuration options can be set using Environment Variables.
4480 List of environment variables (most likely not complete):
4482 baudrate - see CONFIG_BAUDRATE
4484 bootdelay - see CONFIG_BOOTDELAY
4486 bootcmd - see CONFIG_BOOTCOMMAND
4488 bootargs - Boot arguments when booting an RTOS image
4490 bootfile - Name of the image to load with TFTP
4492 bootm_low - Memory range available for image processing in the bootm
4493 command can be restricted. This variable is given as
4494 a hexadecimal number and defines lowest address allowed
4495 for use by the bootm command. See also "bootm_size"
4496 environment variable. Address defined by "bootm_low" is
4497 also the base of the initial memory mapping for the Linux
4498 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4501 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4502 This variable is given as a hexadecimal number and it
4503 defines the size of the memory region starting at base
4504 address bootm_low that is accessible by the Linux kernel
4505 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4506 as the default value if it is defined, and bootm_size is
4509 bootm_size - Memory range available for image processing in the bootm
4510 command can be restricted. This variable is given as
4511 a hexadecimal number and defines the size of the region
4512 allowed for use by the bootm command. See also "bootm_low"
4513 environment variable.
4515 updatefile - Location of the software update file on a TFTP server, used
4516 by the automatic software update feature. Please refer to
4517 documentation in doc/README.update for more details.
4519 autoload - if set to "no" (any string beginning with 'n'),
4520 "bootp" will just load perform a lookup of the
4521 configuration from the BOOTP server, but not try to
4522 load any image using TFTP
4524 autostart - if set to "yes", an image loaded using the "bootp",
4525 "rarpboot", "tftpboot" or "diskboot" commands will
4526 be automatically started (by internally calling
4529 If set to "no", a standalone image passed to the
4530 "bootm" command will be copied to the load address
4531 (and eventually uncompressed), but NOT be started.
4532 This can be used to load and uncompress arbitrary
4535 fdt_high - if set this restricts the maximum address that the
4536 flattened device tree will be copied into upon boot.
4537 For example, if you have a system with 1 GB memory
4538 at physical address 0x10000000, while Linux kernel
4539 only recognizes the first 704 MB as low memory, you
4540 may need to set fdt_high as 0x3C000000 to have the
4541 device tree blob be copied to the maximum address
4542 of the 704 MB low memory, so that Linux kernel can
4543 access it during the boot procedure.
4545 If this is set to the special value 0xFFFFFFFF then
4546 the fdt will not be copied at all on boot. For this
4547 to work it must reside in writable memory, have
4548 sufficient padding on the end of it for u-boot to
4549 add the information it needs into it, and the memory
4550 must be accessible by the kernel.
4552 fdtcontroladdr- if set this is the address of the control flattened
4553 device tree used by U-Boot when CONFIG_OF_CONTROL is
4556 i2cfast - (PPC405GP|PPC405EP only)
4557 if set to 'y' configures Linux I2C driver for fast
4558 mode (400kHZ). This environment variable is used in
4559 initialization code. So, for changes to be effective
4560 it must be saved and board must be reset.
4562 initrd_high - restrict positioning of initrd images:
4563 If this variable is not set, initrd images will be
4564 copied to the highest possible address in RAM; this
4565 is usually what you want since it allows for
4566 maximum initrd size. If for some reason you want to
4567 make sure that the initrd image is loaded below the
4568 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4569 variable to a value of "no" or "off" or "0".
4570 Alternatively, you can set it to a maximum upper
4571 address to use (U-Boot will still check that it
4572 does not overwrite the U-Boot stack and data).
4574 For instance, when you have a system with 16 MB
4575 RAM, and want to reserve 4 MB from use by Linux,
4576 you can do this by adding "mem=12M" to the value of
4577 the "bootargs" variable. However, now you must make
4578 sure that the initrd image is placed in the first
4579 12 MB as well - this can be done with
4581 setenv initrd_high 00c00000
4583 If you set initrd_high to 0xFFFFFFFF, this is an
4584 indication to U-Boot that all addresses are legal
4585 for the Linux kernel, including addresses in flash
4586 memory. In this case U-Boot will NOT COPY the
4587 ramdisk at all. This may be useful to reduce the
4588 boot time on your system, but requires that this
4589 feature is supported by your Linux kernel.
4591 ipaddr - IP address; needed for tftpboot command
4593 loadaddr - Default load address for commands like "bootp",
4594 "rarpboot", "tftpboot", "loadb" or "diskboot"
4596 loads_echo - see CONFIG_LOADS_ECHO
4598 serverip - TFTP server IP address; needed for tftpboot command
4600 bootretry - see CONFIG_BOOT_RETRY_TIME
4602 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4604 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4606 ethprime - controls which interface is used first.
4608 ethact - controls which interface is currently active.
4609 For example you can do the following
4611 => setenv ethact FEC
4612 => ping 192.168.0.1 # traffic sent on FEC
4613 => setenv ethact SCC
4614 => ping 10.0.0.1 # traffic sent on SCC
4616 ethrotate - When set to "no" U-Boot does not go through all
4617 available network interfaces.
4618 It just stays at the currently selected interface.
4620 netretry - When set to "no" each network operation will
4621 either succeed or fail without retrying.
4622 When set to "once" the network operation will
4623 fail when all the available network interfaces
4624 are tried once without success.
4625 Useful on scripts which control the retry operation
4628 npe_ucode - set load address for the NPE microcode
4630 silent_linux - If set then linux will be told to boot silently, by
4631 changing the console to be empty. If "yes" it will be
4632 made silent. If "no" it will not be made silent. If
4633 unset, then it will be made silent if the U-Boot console
4636 tftpsrcport - If this is set, the value is used for TFTP's
4639 tftpdstport - If this is set, the value is used for TFTP's UDP
4640 destination port instead of the Well Know Port 69.
4642 tftpblocksize - Block size to use for TFTP transfers; if not set,
4643 we use the TFTP server's default block size
4645 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4646 seconds, minimum value is 1000 = 1 second). Defines
4647 when a packet is considered to be lost so it has to
4648 be retransmitted. The default is 5000 = 5 seconds.
4649 Lowering this value may make downloads succeed
4650 faster in networks with high packet loss rates or
4651 with unreliable TFTP servers.
4653 vlan - When set to a value < 4095 the traffic over
4654 Ethernet is encapsulated/received over 802.1q
4657 The following image location variables contain the location of images
4658 used in booting. The "Image" column gives the role of the image and is
4659 not an environment variable name. The other columns are environment
4660 variable names. "File Name" gives the name of the file on a TFTP
4661 server, "RAM Address" gives the location in RAM the image will be
4662 loaded to, and "Flash Location" gives the image's address in NOR
4663 flash or offset in NAND flash.
4665 *Note* - these variables don't have to be defined for all boards, some
4666 boards currenlty use other variables for these purposes, and some
4667 boards use these variables for other purposes.
4669 Image File Name RAM Address Flash Location
4670 ----- --------- ----------- --------------
4671 u-boot u-boot u-boot_addr_r u-boot_addr
4672 Linux kernel bootfile kernel_addr_r kernel_addr
4673 device tree blob fdtfile fdt_addr_r fdt_addr
4674 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4676 The following environment variables may be used and automatically
4677 updated by the network boot commands ("bootp" and "rarpboot"),
4678 depending the information provided by your boot server:
4680 bootfile - see above
4681 dnsip - IP address of your Domain Name Server
4682 dnsip2 - IP address of your secondary Domain Name Server
4683 gatewayip - IP address of the Gateway (Router) to use
4684 hostname - Target hostname
4686 netmask - Subnet Mask
4687 rootpath - Pathname of the root filesystem on the NFS server
4688 serverip - see above
4691 There are two special Environment Variables:
4693 serial# - contains hardware identification information such
4694 as type string and/or serial number
4695 ethaddr - Ethernet address
4697 These variables can be set only once (usually during manufacturing of
4698 the board). U-Boot refuses to delete or overwrite these variables
4699 once they have been set once.
4702 Further special Environment Variables:
4704 ver - Contains the U-Boot version string as printed
4705 with the "version" command. This variable is
4706 readonly (see CONFIG_VERSION_VARIABLE).
4709 Please note that changes to some configuration parameters may take
4710 only effect after the next boot (yes, that's just like Windoze :-).
4713 Callback functions for environment variables:
4714 ---------------------------------------------
4716 For some environment variables, the behavior of u-boot needs to change
4717 when their values are changed. This functionailty allows functions to
4718 be associated with arbitrary variables. On creation, overwrite, or
4719 deletion, the callback will provide the opportunity for some side
4720 effect to happen or for the change to be rejected.
4722 The callbacks are named and associated with a function using the
4723 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4725 These callbacks are associated with variables in one of two ways. The
4726 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4727 in the board configuration to a string that defines a list of
4728 associations. The list must be in the following format:
4730 entry = variable_name[:callback_name]
4733 If the callback name is not specified, then the callback is deleted.
4734 Spaces are also allowed anywhere in the list.
4736 Callbacks can also be associated by defining the ".callbacks" variable
4737 with the same list format above. Any association in ".callbacks" will
4738 override any association in the static list. You can define
4739 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4740 ".callbacks" envirnoment variable in the default or embedded environment.
4743 Command Line Parsing:
4744 =====================
4746 There are two different command line parsers available with U-Boot:
4747 the old "simple" one, and the much more powerful "hush" shell:
4749 Old, simple command line parser:
4750 --------------------------------
4752 - supports environment variables (through setenv / saveenv commands)
4753 - several commands on one line, separated by ';'
4754 - variable substitution using "... ${name} ..." syntax
4755 - special characters ('$', ';') can be escaped by prefixing with '\',
4757 setenv bootcmd bootm \${address}
4758 - You can also escape text by enclosing in single apostrophes, for example:
4759 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4764 - similar to Bourne shell, with control structures like
4765 if...then...else...fi, for...do...done; while...do...done,
4766 until...do...done, ...
4767 - supports environment ("global") variables (through setenv / saveenv
4768 commands) and local shell variables (through standard shell syntax
4769 "name=value"); only environment variables can be used with "run"
4775 (1) If a command line (or an environment variable executed by a "run"
4776 command) contains several commands separated by semicolon, and
4777 one of these commands fails, then the remaining commands will be
4780 (2) If you execute several variables with one call to run (i. e.
4781 calling run with a list of variables as arguments), any failing
4782 command will cause "run" to terminate, i. e. the remaining
4783 variables are not executed.
4785 Note for Redundant Ethernet Interfaces:
4786 =======================================
4788 Some boards come with redundant Ethernet interfaces; U-Boot supports
4789 such configurations and is capable of automatic selection of a
4790 "working" interface when needed. MAC assignment works as follows:
4792 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4793 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4794 "eth1addr" (=>eth1), "eth2addr", ...
4796 If the network interface stores some valid MAC address (for instance
4797 in SROM), this is used as default address if there is NO correspon-
4798 ding setting in the environment; if the corresponding environment
4799 variable is set, this overrides the settings in the card; that means:
4801 o If the SROM has a valid MAC address, and there is no address in the
4802 environment, the SROM's address is used.
4804 o If there is no valid address in the SROM, and a definition in the
4805 environment exists, then the value from the environment variable is
4808 o If both the SROM and the environment contain a MAC address, and
4809 both addresses are the same, this MAC address is used.
4811 o If both the SROM and the environment contain a MAC address, and the
4812 addresses differ, the value from the environment is used and a
4815 o If neither SROM nor the environment contain a MAC address, an error
4818 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4819 will be programmed into hardware as part of the initialization process. This
4820 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4821 The naming convention is as follows:
4822 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4827 U-Boot is capable of booting (and performing other auxiliary operations on)
4828 images in two formats:
4830 New uImage format (FIT)
4831 -----------------------
4833 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4834 to Flattened Device Tree). It allows the use of images with multiple
4835 components (several kernels, ramdisks, etc.), with contents protected by
4836 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4842 Old image format is based on binary files which can be basically anything,
4843 preceded by a special header; see the definitions in include/image.h for
4844 details; basically, the header defines the following image properties:
4846 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4847 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4848 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4849 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4851 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4852 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4853 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4854 * Compression Type (uncompressed, gzip, bzip2)
4860 The header is marked by a special Magic Number, and both the header
4861 and the data portions of the image are secured against corruption by
4868 Although U-Boot should support any OS or standalone application
4869 easily, the main focus has always been on Linux during the design of
4872 U-Boot includes many features that so far have been part of some
4873 special "boot loader" code within the Linux kernel. Also, any
4874 "initrd" images to be used are no longer part of one big Linux image;
4875 instead, kernel and "initrd" are separate images. This implementation
4876 serves several purposes:
4878 - the same features can be used for other OS or standalone
4879 applications (for instance: using compressed images to reduce the
4880 Flash memory footprint)
4882 - it becomes much easier to port new Linux kernel versions because
4883 lots of low-level, hardware dependent stuff are done by U-Boot
4885 - the same Linux kernel image can now be used with different "initrd"
4886 images; of course this also means that different kernel images can
4887 be run with the same "initrd". This makes testing easier (you don't
4888 have to build a new "zImage.initrd" Linux image when you just
4889 change a file in your "initrd"). Also, a field-upgrade of the
4890 software is easier now.
4896 Porting Linux to U-Boot based systems:
4897 ---------------------------------------
4899 U-Boot cannot save you from doing all the necessary modifications to
4900 configure the Linux device drivers for use with your target hardware
4901 (no, we don't intend to provide a full virtual machine interface to
4904 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4906 Just make sure your machine specific header file (for instance
4907 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4908 Information structure as we define in include/asm-<arch>/u-boot.h,
4909 and make sure that your definition of IMAP_ADDR uses the same value
4910 as your U-Boot configuration in CONFIG_SYS_IMMR.
4913 Configuring the Linux kernel:
4914 -----------------------------
4916 No specific requirements for U-Boot. Make sure you have some root
4917 device (initial ramdisk, NFS) for your target system.
4920 Building a Linux Image:
4921 -----------------------
4923 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4924 not used. If you use recent kernel source, a new build target
4925 "uImage" will exist which automatically builds an image usable by
4926 U-Boot. Most older kernels also have support for a "pImage" target,
4927 which was introduced for our predecessor project PPCBoot and uses a
4928 100% compatible format.
4937 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4938 encapsulate a compressed Linux kernel image with header information,
4939 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4941 * build a standard "vmlinux" kernel image (in ELF binary format):
4943 * convert the kernel into a raw binary image:
4945 ${CROSS_COMPILE}-objcopy -O binary \
4946 -R .note -R .comment \
4947 -S vmlinux linux.bin
4949 * compress the binary image:
4953 * package compressed binary image for U-Boot:
4955 mkimage -A ppc -O linux -T kernel -C gzip \
4956 -a 0 -e 0 -n "Linux Kernel Image" \
4957 -d linux.bin.gz uImage
4960 The "mkimage" tool can also be used to create ramdisk images for use
4961 with U-Boot, either separated from the Linux kernel image, or
4962 combined into one file. "mkimage" encapsulates the images with a 64
4963 byte header containing information about target architecture,
4964 operating system, image type, compression method, entry points, time
4965 stamp, CRC32 checksums, etc.
4967 "mkimage" can be called in two ways: to verify existing images and
4968 print the header information, or to build new images.
4970 In the first form (with "-l" option) mkimage lists the information
4971 contained in the header of an existing U-Boot image; this includes
4972 checksum verification:
4974 tools/mkimage -l image
4975 -l ==> list image header information
4977 The second form (with "-d" option) is used to build a U-Boot image
4978 from a "data file" which is used as image payload:
4980 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4981 -n name -d data_file image
4982 -A ==> set architecture to 'arch'
4983 -O ==> set operating system to 'os'
4984 -T ==> set image type to 'type'
4985 -C ==> set compression type 'comp'
4986 -a ==> set load address to 'addr' (hex)
4987 -e ==> set entry point to 'ep' (hex)
4988 -n ==> set image name to 'name'
4989 -d ==> use image data from 'datafile'
4991 Right now, all Linux kernels for PowerPC systems use the same load
4992 address (0x00000000), but the entry point address depends on the
4995 - 2.2.x kernels have the entry point at 0x0000000C,
4996 - 2.3.x and later kernels have the entry point at 0x00000000.
4998 So a typical call to build a U-Boot image would read:
5000 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5001 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5002 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5003 > examples/uImage.TQM850L
5004 Image Name: 2.4.4 kernel for TQM850L
5005 Created: Wed Jul 19 02:34:59 2000
5006 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5007 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5008 Load Address: 0x00000000
5009 Entry Point: 0x00000000
5011 To verify the contents of the image (or check for corruption):
5013 -> tools/mkimage -l examples/uImage.TQM850L
5014 Image Name: 2.4.4 kernel for TQM850L
5015 Created: Wed Jul 19 02:34:59 2000
5016 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5017 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5018 Load Address: 0x00000000
5019 Entry Point: 0x00000000
5021 NOTE: for embedded systems where boot time is critical you can trade
5022 speed for memory and install an UNCOMPRESSED image instead: this
5023 needs more space in Flash, but boots much faster since it does not
5024 need to be uncompressed:
5026 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5027 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5028 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5029 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5030 > examples/uImage.TQM850L-uncompressed
5031 Image Name: 2.4.4 kernel for TQM850L
5032 Created: Wed Jul 19 02:34:59 2000
5033 Image Type: PowerPC Linux Kernel Image (uncompressed)
5034 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5035 Load Address: 0x00000000
5036 Entry Point: 0x00000000
5039 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5040 when your kernel is intended to use an initial ramdisk:
5042 -> tools/mkimage -n 'Simple Ramdisk Image' \
5043 > -A ppc -O linux -T ramdisk -C gzip \
5044 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5045 Image Name: Simple Ramdisk Image
5046 Created: Wed Jan 12 14:01:50 2000
5047 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5048 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5049 Load Address: 0x00000000
5050 Entry Point: 0x00000000
5053 Installing a Linux Image:
5054 -------------------------
5056 To downloading a U-Boot image over the serial (console) interface,
5057 you must convert the image to S-Record format:
5059 objcopy -I binary -O srec examples/image examples/image.srec
5061 The 'objcopy' does not understand the information in the U-Boot
5062 image header, so the resulting S-Record file will be relative to
5063 address 0x00000000. To load it to a given address, you need to
5064 specify the target address as 'offset' parameter with the 'loads'
5067 Example: install the image to address 0x40100000 (which on the
5068 TQM8xxL is in the first Flash bank):
5070 => erase 40100000 401FFFFF
5076 ## Ready for S-Record download ...
5077 ~>examples/image.srec
5078 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5080 15989 15990 15991 15992
5081 [file transfer complete]
5083 ## Start Addr = 0x00000000
5086 You can check the success of the download using the 'iminfo' command;
5087 this includes a checksum verification so you can be sure no data
5088 corruption happened:
5092 ## Checking Image at 40100000 ...
5093 Image Name: 2.2.13 for initrd on TQM850L
5094 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5095 Data Size: 335725 Bytes = 327 kB = 0 MB
5096 Load Address: 00000000
5097 Entry Point: 0000000c
5098 Verifying Checksum ... OK
5104 The "bootm" command is used to boot an application that is stored in
5105 memory (RAM or Flash). In case of a Linux kernel image, the contents
5106 of the "bootargs" environment variable is passed to the kernel as
5107 parameters. You can check and modify this variable using the
5108 "printenv" and "setenv" commands:
5111 => printenv bootargs
5112 bootargs=root=/dev/ram
5114 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5116 => printenv bootargs
5117 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5120 ## Booting Linux kernel at 40020000 ...
5121 Image Name: 2.2.13 for NFS on TQM850L
5122 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5123 Data Size: 381681 Bytes = 372 kB = 0 MB
5124 Load Address: 00000000
5125 Entry Point: 0000000c
5126 Verifying Checksum ... OK
5127 Uncompressing Kernel Image ... OK
5128 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
5129 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5130 time_init: decrementer frequency = 187500000/60
5131 Calibrating delay loop... 49.77 BogoMIPS
5132 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5135 If you want to boot a Linux kernel with initial RAM disk, you pass
5136 the memory addresses of both the kernel and the initrd image (PPBCOOT
5137 format!) to the "bootm" command:
5139 => imi 40100000 40200000
5141 ## Checking Image at 40100000 ...
5142 Image Name: 2.2.13 for initrd on TQM850L
5143 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5144 Data Size: 335725 Bytes = 327 kB = 0 MB
5145 Load Address: 00000000
5146 Entry Point: 0000000c
5147 Verifying Checksum ... OK
5149 ## Checking Image at 40200000 ...
5150 Image Name: Simple Ramdisk Image
5151 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5152 Data Size: 566530 Bytes = 553 kB = 0 MB
5153 Load Address: 00000000
5154 Entry Point: 00000000
5155 Verifying Checksum ... OK
5157 => bootm 40100000 40200000
5158 ## Booting Linux kernel at 40100000 ...
5159 Image Name: 2.2.13 for initrd on TQM850L
5160 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5161 Data Size: 335725 Bytes = 327 kB = 0 MB
5162 Load Address: 00000000
5163 Entry Point: 0000000c
5164 Verifying Checksum ... OK
5165 Uncompressing Kernel Image ... OK
5166 ## Loading RAMDisk Image at 40200000 ...
5167 Image Name: Simple Ramdisk Image
5168 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5169 Data Size: 566530 Bytes = 553 kB = 0 MB
5170 Load Address: 00000000
5171 Entry Point: 00000000
5172 Verifying Checksum ... OK
5173 Loading Ramdisk ... OK
5174 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
5175 Boot arguments: root=/dev/ram
5176 time_init: decrementer frequency = 187500000/60
5177 Calibrating delay loop... 49.77 BogoMIPS
5179 RAMDISK: Compressed image found at block 0
5180 VFS: Mounted root (ext2 filesystem).
5184 Boot Linux and pass a flat device tree:
5187 First, U-Boot must be compiled with the appropriate defines. See the section
5188 titled "Linux Kernel Interface" above for a more in depth explanation. The
5189 following is an example of how to start a kernel and pass an updated
5195 oft=oftrees/mpc8540ads.dtb
5196 => tftp $oftaddr $oft
5197 Speed: 1000, full duplex
5199 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5200 Filename 'oftrees/mpc8540ads.dtb'.
5201 Load address: 0x300000
5204 Bytes transferred = 4106 (100a hex)
5205 => tftp $loadaddr $bootfile
5206 Speed: 1000, full duplex
5208 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5210 Load address: 0x200000
5211 Loading:############
5213 Bytes transferred = 1029407 (fb51f hex)
5218 => bootm $loadaddr - $oftaddr
5219 ## Booting image at 00200000 ...
5220 Image Name: Linux-2.6.17-dirty
5221 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5222 Data Size: 1029343 Bytes = 1005.2 kB
5223 Load Address: 00000000
5224 Entry Point: 00000000
5225 Verifying Checksum ... OK
5226 Uncompressing Kernel Image ... OK
5227 Booting using flat device tree at 0x300000
5228 Using MPC85xx ADS machine description
5229 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5233 More About U-Boot Image Types:
5234 ------------------------------
5236 U-Boot supports the following image types:
5238 "Standalone Programs" are directly runnable in the environment
5239 provided by U-Boot; it is expected that (if they behave
5240 well) you can continue to work in U-Boot after return from
5241 the Standalone Program.
5242 "OS Kernel Images" are usually images of some Embedded OS which
5243 will take over control completely. Usually these programs
5244 will install their own set of exception handlers, device
5245 drivers, set up the MMU, etc. - this means, that you cannot
5246 expect to re-enter U-Boot except by resetting the CPU.
5247 "RAMDisk Images" are more or less just data blocks, and their
5248 parameters (address, size) are passed to an OS kernel that is
5250 "Multi-File Images" contain several images, typically an OS
5251 (Linux) kernel image and one or more data images like
5252 RAMDisks. This construct is useful for instance when you want
5253 to boot over the network using BOOTP etc., where the boot
5254 server provides just a single image file, but you want to get
5255 for instance an OS kernel and a RAMDisk image.
5257 "Multi-File Images" start with a list of image sizes, each
5258 image size (in bytes) specified by an "uint32_t" in network
5259 byte order. This list is terminated by an "(uint32_t)0".
5260 Immediately after the terminating 0 follow the images, one by
5261 one, all aligned on "uint32_t" boundaries (size rounded up to
5262 a multiple of 4 bytes).
5264 "Firmware Images" are binary images containing firmware (like
5265 U-Boot or FPGA images) which usually will be programmed to
5268 "Script files" are command sequences that will be executed by
5269 U-Boot's command interpreter; this feature is especially
5270 useful when you configure U-Boot to use a real shell (hush)
5271 as command interpreter.
5273 Booting the Linux zImage:
5274 -------------------------
5276 On some platforms, it's possible to boot Linux zImage. This is done
5277 using the "bootz" command. The syntax of "bootz" command is the same
5278 as the syntax of "bootm" command.
5280 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5281 kernel with raw initrd images. The syntax is slightly different, the
5282 address of the initrd must be augmented by it's size, in the following
5283 format: "<initrd addres>:<initrd size>".
5289 One of the features of U-Boot is that you can dynamically load and
5290 run "standalone" applications, which can use some resources of
5291 U-Boot like console I/O functions or interrupt services.
5293 Two simple examples are included with the sources:
5298 'examples/hello_world.c' contains a small "Hello World" Demo
5299 application; it is automatically compiled when you build U-Boot.
5300 It's configured to run at address 0x00040004, so you can play with it
5304 ## Ready for S-Record download ...
5305 ~>examples/hello_world.srec
5306 1 2 3 4 5 6 7 8 9 10 11 ...
5307 [file transfer complete]
5309 ## Start Addr = 0x00040004
5311 => go 40004 Hello World! This is a test.
5312 ## Starting application at 0x00040004 ...
5323 Hit any key to exit ...
5325 ## Application terminated, rc = 0x0
5327 Another example, which demonstrates how to register a CPM interrupt
5328 handler with the U-Boot code, can be found in 'examples/timer.c'.
5329 Here, a CPM timer is set up to generate an interrupt every second.
5330 The interrupt service routine is trivial, just printing a '.'
5331 character, but this is just a demo program. The application can be
5332 controlled by the following keys:
5334 ? - print current values og the CPM Timer registers
5335 b - enable interrupts and start timer
5336 e - stop timer and disable interrupts
5337 q - quit application
5340 ## Ready for S-Record download ...
5341 ~>examples/timer.srec
5342 1 2 3 4 5 6 7 8 9 10 11 ...
5343 [file transfer complete]
5345 ## Start Addr = 0x00040004
5348 ## Starting application at 0x00040004 ...
5351 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5354 [q, b, e, ?] Set interval 1000000 us
5357 [q, b, e, ?] ........
5358 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5361 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5364 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5367 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5369 [q, b, e, ?] ...Stopping timer
5371 [q, b, e, ?] ## Application terminated, rc = 0x0
5377 Over time, many people have reported problems when trying to use the
5378 "minicom" terminal emulation program for serial download. I (wd)
5379 consider minicom to be broken, and recommend not to use it. Under
5380 Unix, I recommend to use C-Kermit for general purpose use (and
5381 especially for kermit binary protocol download ("loadb" command), and
5382 use "cu" for S-Record download ("loads" command). See
5383 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5384 for help with kermit.
5387 Nevertheless, if you absolutely want to use it try adding this
5388 configuration to your "File transfer protocols" section:
5390 Name Program Name U/D FullScr IO-Red. Multi
5391 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5392 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5398 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5399 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5401 Building requires a cross environment; it is known to work on
5402 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5403 need gmake since the Makefiles are not compatible with BSD make).
5404 Note that the cross-powerpc package does not install include files;
5405 attempting to build U-Boot will fail because <machine/ansi.h> is
5406 missing. This file has to be installed and patched manually:
5408 # cd /usr/pkg/cross/powerpc-netbsd/include
5410 # ln -s powerpc machine
5411 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5412 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5414 Native builds *don't* work due to incompatibilities between native
5415 and U-Boot include files.
5417 Booting assumes that (the first part of) the image booted is a
5418 stage-2 loader which in turn loads and then invokes the kernel
5419 proper. Loader sources will eventually appear in the NetBSD source
5420 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5421 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5424 Implementation Internals:
5425 =========================
5427 The following is not intended to be a complete description of every
5428 implementation detail. However, it should help to understand the
5429 inner workings of U-Boot and make it easier to port it to custom
5433 Initial Stack, Global Data:
5434 ---------------------------
5436 The implementation of U-Boot is complicated by the fact that U-Boot
5437 starts running out of ROM (flash memory), usually without access to
5438 system RAM (because the memory controller is not initialized yet).
5439 This means that we don't have writable Data or BSS segments, and BSS
5440 is not initialized as zero. To be able to get a C environment working
5441 at all, we have to allocate at least a minimal stack. Implementation
5442 options for this are defined and restricted by the CPU used: Some CPU
5443 models provide on-chip memory (like the IMMR area on MPC8xx and
5444 MPC826x processors), on others (parts of) the data cache can be
5445 locked as (mis-) used as memory, etc.
5447 Chris Hallinan posted a good summary of these issues to the
5448 U-Boot mailing list:
5450 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5451 From: "Chris Hallinan" <clh@net1plus.com>
5452 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5455 Correct me if I'm wrong, folks, but the way I understand it
5456 is this: Using DCACHE as initial RAM for Stack, etc, does not
5457 require any physical RAM backing up the cache. The cleverness
5458 is that the cache is being used as a temporary supply of
5459 necessary storage before the SDRAM controller is setup. It's
5460 beyond the scope of this list to explain the details, but you
5461 can see how this works by studying the cache architecture and
5462 operation in the architecture and processor-specific manuals.
5464 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5465 is another option for the system designer to use as an
5466 initial stack/RAM area prior to SDRAM being available. Either
5467 option should work for you. Using CS 4 should be fine if your
5468 board designers haven't used it for something that would
5469 cause you grief during the initial boot! It is frequently not
5472 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5473 with your processor/board/system design. The default value
5474 you will find in any recent u-boot distribution in
5475 walnut.h should work for you. I'd set it to a value larger
5476 than your SDRAM module. If you have a 64MB SDRAM module, set
5477 it above 400_0000. Just make sure your board has no resources
5478 that are supposed to respond to that address! That code in
5479 start.S has been around a while and should work as is when
5480 you get the config right.
5485 It is essential to remember this, since it has some impact on the C
5486 code for the initialization procedures:
5488 * Initialized global data (data segment) is read-only. Do not attempt
5491 * Do not use any uninitialized global data (or implicitely initialized
5492 as zero data - BSS segment) at all - this is undefined, initiali-
5493 zation is performed later (when relocating to RAM).
5495 * Stack space is very limited. Avoid big data buffers or things like
5498 Having only the stack as writable memory limits means we cannot use
5499 normal global data to share information beween the code. But it
5500 turned out that the implementation of U-Boot can be greatly
5501 simplified by making a global data structure (gd_t) available to all
5502 functions. We could pass a pointer to this data as argument to _all_
5503 functions, but this would bloat the code. Instead we use a feature of
5504 the GCC compiler (Global Register Variables) to share the data: we
5505 place a pointer (gd) to the global data into a register which we
5506 reserve for this purpose.
5508 When choosing a register for such a purpose we are restricted by the
5509 relevant (E)ABI specifications for the current architecture, and by
5510 GCC's implementation.
5512 For PowerPC, the following registers have specific use:
5514 R2: reserved for system use
5515 R3-R4: parameter passing and return values
5516 R5-R10: parameter passing
5517 R13: small data area pointer
5521 (U-Boot also uses R12 as internal GOT pointer. r12
5522 is a volatile register so r12 needs to be reset when
5523 going back and forth between asm and C)
5525 ==> U-Boot will use R2 to hold a pointer to the global data
5527 Note: on PPC, we could use a static initializer (since the
5528 address of the global data structure is known at compile time),
5529 but it turned out that reserving a register results in somewhat
5530 smaller code - although the code savings are not that big (on
5531 average for all boards 752 bytes for the whole U-Boot image,
5532 624 text + 127 data).
5534 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5535 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5537 ==> U-Boot will use P3 to hold a pointer to the global data
5539 On ARM, the following registers are used:
5541 R0: function argument word/integer result
5542 R1-R3: function argument word
5544 R10: stack limit (used only if stack checking if enabled)
5545 R11: argument (frame) pointer
5546 R12: temporary workspace
5549 R15: program counter
5551 ==> U-Boot will use R8 to hold a pointer to the global data
5553 On Nios II, the ABI is documented here:
5554 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5556 ==> U-Boot will use gp to hold a pointer to the global data
5558 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5559 to access small data sections, so gp is free.
5561 On NDS32, the following registers are used:
5563 R0-R1: argument/return
5565 R15: temporary register for assembler
5566 R16: trampoline register
5567 R28: frame pointer (FP)
5568 R29: global pointer (GP)
5569 R30: link register (LP)
5570 R31: stack pointer (SP)
5571 PC: program counter (PC)
5573 ==> U-Boot will use R10 to hold a pointer to the global data
5575 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5576 or current versions of GCC may "optimize" the code too much.
5581 U-Boot runs in system state and uses physical addresses, i.e. the
5582 MMU is not used either for address mapping nor for memory protection.
5584 The available memory is mapped to fixed addresses using the memory
5585 controller. In this process, a contiguous block is formed for each
5586 memory type (Flash, SDRAM, SRAM), even when it consists of several
5587 physical memory banks.
5589 U-Boot is installed in the first 128 kB of the first Flash bank (on
5590 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5591 booting and sizing and initializing DRAM, the code relocates itself
5592 to the upper end of DRAM. Immediately below the U-Boot code some
5593 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5594 configuration setting]. Below that, a structure with global Board
5595 Info data is placed, followed by the stack (growing downward).
5597 Additionally, some exception handler code is copied to the low 8 kB
5598 of DRAM (0x00000000 ... 0x00001FFF).
5600 So a typical memory configuration with 16 MB of DRAM could look like
5603 0x0000 0000 Exception Vector code
5606 0x0000 2000 Free for Application Use
5612 0x00FB FF20 Monitor Stack (Growing downward)
5613 0x00FB FFAC Board Info Data and permanent copy of global data
5614 0x00FC 0000 Malloc Arena
5617 0x00FE 0000 RAM Copy of Monitor Code
5618 ... eventually: LCD or video framebuffer
5619 ... eventually: pRAM (Protected RAM - unchanged by reset)
5620 0x00FF FFFF [End of RAM]
5623 System Initialization:
5624 ----------------------
5626 In the reset configuration, U-Boot starts at the reset entry point
5627 (on most PowerPC systems at address 0x00000100). Because of the reset
5628 configuration for CS0# this is a mirror of the onboard Flash memory.
5629 To be able to re-map memory U-Boot then jumps to its link address.
5630 To be able to implement the initialization code in C, a (small!)
5631 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5632 which provide such a feature like MPC8xx or MPC8260), or in a locked
5633 part of the data cache. After that, U-Boot initializes the CPU core,
5634 the caches and the SIU.
5636 Next, all (potentially) available memory banks are mapped using a
5637 preliminary mapping. For example, we put them on 512 MB boundaries
5638 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5639 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5640 programmed for SDRAM access. Using the temporary configuration, a
5641 simple memory test is run that determines the size of the SDRAM
5644 When there is more than one SDRAM bank, and the banks are of
5645 different size, the largest is mapped first. For equal size, the first
5646 bank (CS2#) is mapped first. The first mapping is always for address
5647 0x00000000, with any additional banks following immediately to create
5648 contiguous memory starting from 0.
5650 Then, the monitor installs itself at the upper end of the SDRAM area
5651 and allocates memory for use by malloc() and for the global Board
5652 Info data; also, the exception vector code is copied to the low RAM
5653 pages, and the final stack is set up.
5655 Only after this relocation will you have a "normal" C environment;
5656 until that you are restricted in several ways, mostly because you are
5657 running from ROM, and because the code will have to be relocated to a
5661 U-Boot Porting Guide:
5662 ----------------------
5664 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5668 int main(int argc, char *argv[])
5670 sighandler_t no_more_time;
5672 signal(SIGALRM, no_more_time);
5673 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5675 if (available_money > available_manpower) {
5676 Pay consultant to port U-Boot;
5680 Download latest U-Boot source;
5682 Subscribe to u-boot mailing list;
5685 email("Hi, I am new to U-Boot, how do I get started?");
5688 Read the README file in the top level directory;
5689 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5690 Read applicable doc/*.README;
5691 Read the source, Luke;
5692 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5695 if (available_money > toLocalCurrency ($2500))
5698 Add a lot of aggravation and time;
5700 if (a similar board exists) { /* hopefully... */
5701 cp -a board/<similar> board/<myboard>
5702 cp include/configs/<similar>.h include/configs/<myboard>.h
5704 Create your own board support subdirectory;
5705 Create your own board include/configs/<myboard>.h file;
5707 Edit new board/<myboard> files
5708 Edit new include/configs/<myboard>.h
5713 Add / modify source code;
5717 email("Hi, I am having problems...");
5719 Send patch file to the U-Boot email list;
5720 if (reasonable critiques)
5721 Incorporate improvements from email list code review;
5723 Defend code as written;
5729 void no_more_time (int sig)
5738 All contributions to U-Boot should conform to the Linux kernel
5739 coding style; see the file "Documentation/CodingStyle" and the script
5740 "scripts/Lindent" in your Linux kernel source directory.
5742 Source files originating from a different project (for example the
5743 MTD subsystem) are generally exempt from these guidelines and are not
5744 reformated to ease subsequent migration to newer versions of those
5747 Please note that U-Boot is implemented in C (and to some small parts in
5748 Assembler); no C++ is used, so please do not use C++ style comments (//)
5751 Please also stick to the following formatting rules:
5752 - remove any trailing white space
5753 - use TAB characters for indentation and vertical alignment, not spaces
5754 - make sure NOT to use DOS '\r\n' line feeds
5755 - do not add more than 2 consecutive empty lines to source files
5756 - do not add trailing empty lines to source files
5758 Submissions which do not conform to the standards may be returned
5759 with a request to reformat the changes.
5765 Since the number of patches for U-Boot is growing, we need to
5766 establish some rules. Submissions which do not conform to these rules
5767 may be rejected, even when they contain important and valuable stuff.
5769 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5771 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5772 see http://lists.denx.de/mailman/listinfo/u-boot
5774 When you send a patch, please include the following information with
5777 * For bug fixes: a description of the bug and how your patch fixes
5778 this bug. Please try to include a way of demonstrating that the
5779 patch actually fixes something.
5781 * For new features: a description of the feature and your
5784 * A CHANGELOG entry as plaintext (separate from the patch)
5786 * For major contributions, your entry to the CREDITS file
5788 * When you add support for a new board, don't forget to add this
5789 board to the MAINTAINERS file, too.
5791 * If your patch adds new configuration options, don't forget to
5792 document these in the README file.
5794 * The patch itself. If you are using git (which is *strongly*
5795 recommended) you can easily generate the patch using the
5796 "git format-patch". If you then use "git send-email" to send it to
5797 the U-Boot mailing list, you will avoid most of the common problems
5798 with some other mail clients.
5800 If you cannot use git, use "diff -purN OLD NEW". If your version of
5801 diff does not support these options, then get the latest version of
5804 The current directory when running this command shall be the parent
5805 directory of the U-Boot source tree (i. e. please make sure that
5806 your patch includes sufficient directory information for the
5809 We prefer patches as plain text. MIME attachments are discouraged,
5810 and compressed attachments must not be used.
5812 * If one logical set of modifications affects or creates several
5813 files, all these changes shall be submitted in a SINGLE patch file.
5815 * Changesets that contain different, unrelated modifications shall be
5816 submitted as SEPARATE patches, one patch per changeset.
5821 * Before sending the patch, run the MAKEALL script on your patched
5822 source tree and make sure that no errors or warnings are reported
5823 for any of the boards.
5825 * Keep your modifications to the necessary minimum: A patch
5826 containing several unrelated changes or arbitrary reformats will be
5827 returned with a request to re-formatting / split it.
5829 * If you modify existing code, make sure that your new code does not
5830 add to the memory footprint of the code ;-) Small is beautiful!
5831 When adding new features, these should compile conditionally only
5832 (using #ifdef), and the resulting code with the new feature
5833 disabled must not need more memory than the old code without your
5836 * Remember that there is a size limit of 100 kB per message on the
5837 u-boot mailing list. Bigger patches will be moderated. If they are
5838 reasonable and not too big, they will be acknowledged. But patches
5839 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob