2 # (C) Copyright 2000 - 2012
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
57 Note: There is no CHANGELOG file in the actual U-Boot source tree;
58 it can be created dynamically from the Git log using:
66 In case you have questions about, problems with or contributions for
67 U-Boot you should send a message to the U-Boot mailing list at
69 on the mailing list - please search the archive before asking FAQ's.
70 Please see http://lists.denx.de/pipermail/u-boot and
71 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
74 Where to get source code:
75 =========================
77 The U-Boot source code is maintained in the git repository at
78 git://www.denx.de/git/u-boot.git ; you can browse it online at
79 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
81 The "snapshot" links on this page allow you to download tarballs of
82 any version you might be interested in. Official releases are also
83 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
86 Pre-built (and tested) images are available from
87 ftp://ftp.denx.de/pub/u-boot/images/
93 - start from 8xxrom sources
94 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
96 - make it easier to add custom boards
97 - make it possible to add other [PowerPC] CPUs
98 - extend functions, especially:
99 * Provide extended interface to Linux boot loader
102 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
103 - create ARMBoot project (http://sourceforge.net/projects/armboot)
104 - add other CPU families (starting with ARM)
105 - create U-Boot project (http://sourceforge.net/projects/u-boot)
106 - current project page: see http://www.denx.de/wiki/U-Boot
112 The "official" name of this project is "Das U-Boot". The spelling
113 "U-Boot" shall be used in all written text (documentation, comments
114 in source files etc.). Example:
116 This is the README file for the U-Boot project.
118 File names etc. shall be based on the string "u-boot". Examples:
120 include/asm-ppc/u-boot.h
122 #include <asm/u-boot.h>
124 Variable names, preprocessor constants etc. shall be either based on
125 the string "u_boot" or on "U_BOOT". Example:
127 U_BOOT_VERSION u_boot_logo
128 IH_OS_U_BOOT u_boot_hush_start
134 Starting with the release in October 2008, the names of the releases
135 were changed from numerical release numbers without deeper meaning
136 into a time stamp based numbering. Regular releases are identified by
137 names consisting of the calendar year and month of the release date.
138 Additional fields (if present) indicate release candidates or bug fix
139 releases in "stable" maintenance trees.
142 U-Boot v2009.11 - Release November 2009
143 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
144 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
150 /arch Architecture specific files
151 /arm Files generic to ARM architecture
152 /cpu CPU specific files
153 /arm720t Files specific to ARM 720 CPUs
154 /arm920t Files specific to ARM 920 CPUs
155 /at91 Files specific to Atmel AT91RM9200 CPU
156 /imx Files specific to Freescale MC9328 i.MX CPUs
157 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
158 /arm925t Files specific to ARM 925 CPUs
159 /arm926ejs Files specific to ARM 926 CPUs
160 /arm1136 Files specific to ARM 1136 CPUs
161 /ixp Files specific to Intel XScale IXP CPUs
162 /pxa Files specific to Intel XScale PXA CPUs
163 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
164 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
165 /lib Architecture specific library files
166 /avr32 Files generic to AVR32 architecture
167 /cpu CPU specific files
168 /lib Architecture specific library files
169 /blackfin Files generic to Analog Devices Blackfin architecture
170 /cpu CPU specific files
171 /lib Architecture specific library files
172 /x86 Files generic to x86 architecture
173 /cpu CPU specific files
174 /lib Architecture specific library files
175 /m68k Files generic to m68k architecture
176 /cpu CPU specific files
177 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
178 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
179 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
180 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
181 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
182 /lib Architecture specific library files
183 /microblaze Files generic to microblaze architecture
184 /cpu CPU specific files
185 /lib Architecture specific library files
186 /mips Files generic to MIPS architecture
187 /cpu CPU specific files
188 /mips32 Files specific to MIPS32 CPUs
189 /xburst Files specific to Ingenic XBurst CPUs
190 /lib Architecture specific library files
191 /nds32 Files generic to NDS32 architecture
192 /cpu CPU specific files
193 /n1213 Files specific to Andes Technology N1213 CPUs
194 /lib Architecture specific library files
195 /nios2 Files generic to Altera NIOS2 architecture
196 /cpu CPU specific files
197 /lib Architecture specific library files
198 /powerpc Files generic to PowerPC architecture
199 /cpu CPU specific files
200 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
201 /mpc5xx Files specific to Freescale MPC5xx CPUs
202 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
203 /mpc8xx Files specific to Freescale MPC8xx CPUs
204 /mpc824x Files specific to Freescale MPC824x CPUs
205 /mpc8260 Files specific to Freescale MPC8260 CPUs
206 /mpc85xx Files specific to Freescale MPC85xx CPUs
207 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
208 /lib Architecture specific library files
209 /sh Files generic to SH architecture
210 /cpu CPU specific files
211 /sh2 Files specific to sh2 CPUs
212 /sh3 Files specific to sh3 CPUs
213 /sh4 Files specific to sh4 CPUs
214 /lib Architecture specific library files
215 /sparc Files generic to SPARC architecture
216 /cpu CPU specific files
217 /leon2 Files specific to Gaisler LEON2 SPARC CPU
218 /leon3 Files specific to Gaisler LEON3 SPARC CPU
219 /lib Architecture specific library files
220 /api Machine/arch independent API for external apps
221 /board Board dependent files
222 /common Misc architecture independent functions
223 /disk Code for disk drive partition handling
224 /doc Documentation (don't expect too much)
225 /drivers Commonly used device drivers
226 /examples Example code for standalone applications, etc.
227 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
228 /include Header Files
229 /lib Files generic to all architectures
230 /libfdt Library files to support flattened device trees
231 /lzma Library files to support LZMA decompression
232 /lzo Library files to support LZO decompression
234 /post Power On Self Test
235 /rtc Real Time Clock drivers
236 /tools Tools to build S-Record or U-Boot images, etc.
238 Software Configuration:
239 =======================
241 Configuration is usually done using C preprocessor defines; the
242 rationale behind that is to avoid dead code whenever possible.
244 There are two classes of configuration variables:
246 * Configuration _OPTIONS_:
247 These are selectable by the user and have names beginning with
250 * Configuration _SETTINGS_:
251 These depend on the hardware etc. and should not be meddled with if
252 you don't know what you're doing; they have names beginning with
255 Later we will add a configuration tool - probably similar to or even
256 identical to what's used for the Linux kernel. Right now, we have to
257 do the configuration by hand, which means creating some symbolic
258 links and editing some configuration files. We use the TQM8xxL boards
262 Selection of Processor Architecture and Board Type:
263 ---------------------------------------------------
265 For all supported boards there are ready-to-use default
266 configurations available; just type "make <board_name>_config".
268 Example: For a TQM823L module type:
273 For the Cogent platform, you need to specify the CPU type as well;
274 e.g. "make cogent_mpc8xx_config". And also configure the cogent
275 directory according to the instructions in cogent/README.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Board flavour: (if CONFIG_MPC8260ADS is defined)
327 CONFIG_SYS_8260ADS - original MPC8260ADS
328 CONFIG_SYS_8266ADS - MPC8266ADS
329 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
330 CONFIG_SYS_8272ADS - MPC8272ADS
332 - Marvell Family Member
333 CONFIG_SYS_MVFS - define it if you want to enable
334 multiple fs option at one time
335 for marvell soc family
337 - MPC824X Family Member (if CONFIG_MPC824X is defined)
338 Define exactly one of
339 CONFIG_MPC8240, CONFIG_MPC8245
341 - 8xx CPU Options: (if using an MPC8xx CPU)
342 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
343 get_gclk_freq() cannot work
344 e.g. if there is no 32KHz
345 reference PIT/RTC clock
346 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
349 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
350 CONFIG_SYS_8xx_CPUCLK_MIN
351 CONFIG_SYS_8xx_CPUCLK_MAX
352 CONFIG_8xx_CPUCLK_DEFAULT
353 See doc/README.MPC866
355 CONFIG_SYS_MEASURE_CPUCLK
357 Define this to measure the actual CPU clock instead
358 of relying on the correctness of the configured
359 values. Mostly useful for board bringup to make sure
360 the PLL is locked at the intended frequency. Note
361 that this requires a (stable) reference clock (32 kHz
362 RTC clock or CONFIG_SYS_8XX_XIN)
364 CONFIG_SYS_DELAYED_ICACHE
366 Define this option if you want to enable the
367 ICache only when Code runs from RAM.
372 Specifies that the core is a 64-bit PowerPC implementation (implements
373 the "64" category of the Power ISA). This is necessary for ePAPR
374 compliance, among other possible reasons.
376 CONFIG_SYS_FSL_TBCLK_DIV
378 Defines the core time base clock divider ratio compared to the
379 system clock. On most PQ3 devices this is 8, on newer QorIQ
380 devices it can be 16 or 32. The ratio varies from SoC to Soc.
382 CONFIG_SYS_FSL_PCIE_COMPAT
384 Defines the string to utilize when trying to match PCIe device
385 tree nodes for the given platform.
387 CONFIG_SYS_PPC_E500_DEBUG_TLB
389 Enables a temporary TLB entry to be used during boot to work
390 around limitations in e500v1 and e500v2 external debugger
391 support. This reduces the portions of the boot code where
392 breakpoints and single stepping do not work. The value of this
393 symbol should be set to the TLB1 entry to be used for this
396 CONFIG_SYS_FSL_ERRATUM_A004510
398 Enables a workaround for erratum A004510. If set,
399 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
400 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
402 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
405 Defines one or two SoC revisions (low 8 bits of SVR)
406 for which the A004510 workaround should be applied.
408 The rest of SVR is either not relevant to the decision
409 of whether the erratum is present (e.g. p2040 versus
410 p2041) or is implied by the build target, which controls
411 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
413 See Freescale App Note 4493 for more information about
416 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
418 This is the value to write into CCSR offset 0x18600
419 according to the A004510 workaround.
421 - Generic CPU options:
422 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
424 Defines the endianess of the CPU. Implementation of those
425 values is arch specific.
427 - Intel Monahans options:
428 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
430 Defines the Monahans run mode to oscillator
431 ratio. Valid values are 8, 16, 24, 31. The core
432 frequency is this value multiplied by 13 MHz.
434 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
436 Defines the Monahans turbo mode to oscillator
437 ratio. Valid values are 1 (default if undefined) and
438 2. The core frequency as calculated above is multiplied
442 CONFIG_SYS_INIT_SP_OFFSET
444 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
445 pointer. This is needed for the temporary stack before
448 CONFIG_SYS_MIPS_CACHE_MODE
450 Cache operation mode for the MIPS CPU.
451 See also arch/mips/include/asm/mipsregs.h.
453 CONF_CM_CACHABLE_NO_WA
456 CONF_CM_CACHABLE_NONCOHERENT
460 CONF_CM_CACHABLE_ACCELERATED
462 CONFIG_SYS_XWAY_EBU_BOOTCFG
464 Special option for Lantiq XWAY SoCs for booting from NOR flash.
465 See also arch/mips/cpu/mips32/start.S.
467 CONFIG_XWAY_SWAP_BYTES
469 Enable compilation of tools/xway-swap-bytes needed for Lantiq
470 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
471 be swapped if a flash programmer is used.
474 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
476 Select high exception vectors of the ARM core, e.g., do not
477 clear the V bit of the c1 register of CP15.
479 CONFIG_SYS_THUMB_BUILD
481 Use this flag to build U-Boot using the Thumb instruction
482 set for ARM architectures. Thumb instruction set provides
483 better code density. For ARM architectures that support
484 Thumb2 this flag will result in Thumb2 code generated by
487 CONFIG_ARM_ERRATA_716044
488 CONFIG_ARM_ERRATA_742230
489 CONFIG_ARM_ERRATA_743622
490 CONFIG_ARM_ERRATA_751472
492 If set, the workarounds for these ARM errata are applied early
493 during U-Boot startup. Note that these options force the
494 workarounds to be applied; no CPU-type/version detection
495 exists, unlike the similar options in the Linux kernel. Do not
496 set these options unless they apply!
501 The frequency of the timer returned by get_timer().
502 get_timer() must operate in milliseconds and this CONFIG
503 option must be set to 1000.
505 - Linux Kernel Interface:
508 U-Boot stores all clock information in Hz
509 internally. For binary compatibility with older Linux
510 kernels (which expect the clocks passed in the
511 bd_info data to be in MHz) the environment variable
512 "clocks_in_mhz" can be defined so that U-Boot
513 converts clock data to MHZ before passing it to the
515 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
516 "clocks_in_mhz=1" is automatically included in the
519 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
521 When transferring memsize parameter to linux, some versions
522 expect it to be in bytes, others in MB.
523 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
527 New kernel versions are expecting firmware settings to be
528 passed using flattened device trees (based on open firmware
532 * New libfdt-based support
533 * Adds the "fdt" command
534 * The bootm command automatically updates the fdt
536 OF_CPU - The proper name of the cpus node (only required for
537 MPC512X and MPC5xxx based boards).
538 OF_SOC - The proper name of the soc node (only required for
539 MPC512X and MPC5xxx based boards).
540 OF_TBCLK - The timebase frequency.
541 OF_STDOUT_PATH - The path to the console device
543 boards with QUICC Engines require OF_QE to set UCC MAC
546 CONFIG_OF_BOARD_SETUP
548 Board code has addition modification that it wants to make
549 to the flat device tree before handing it off to the kernel
553 This define fills in the correct boot CPU in the boot
554 param header, the default value is zero if undefined.
558 U-Boot can detect if an IDE device is present or not.
559 If not, and this new config option is activated, U-Boot
560 removes the ATA node from the DTS before booting Linux,
561 so the Linux IDE driver does not probe the device and
562 crash. This is needed for buggy hardware (uc101) where
563 no pull down resistor is connected to the signal IDE5V_DD7.
565 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
567 This setting is mandatory for all boards that have only one
568 machine type and must be used to specify the machine type
569 number as it appears in the ARM machine registry
570 (see http://www.arm.linux.org.uk/developer/machines/).
571 Only boards that have multiple machine types supported
572 in a single configuration file and the machine type is
573 runtime discoverable, do not have to use this setting.
575 - vxWorks boot parameters:
577 bootvx constructs a valid bootline using the following
578 environments variables: bootfile, ipaddr, serverip, hostname.
579 It loads the vxWorks image pointed bootfile.
581 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
582 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
583 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
584 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
586 CONFIG_SYS_VXWORKS_ADD_PARAMS
588 Add it at the end of the bootline. E.g "u=username pw=secret"
590 Note: If a "bootargs" environment is defined, it will overwride
591 the defaults discussed just above.
593 - Cache Configuration:
594 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
595 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
596 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
598 - Cache Configuration for ARM:
599 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
601 CONFIG_SYS_PL310_BASE - Physical base address of PL310
602 controller register space
607 Define this if you want support for Amba PrimeCell PL010 UARTs.
611 Define this if you want support for Amba PrimeCell PL011 UARTs.
615 If you have Amba PrimeCell PL011 UARTs, set this variable to
616 the clock speed of the UARTs.
620 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
621 define this to a list of base addresses for each (supported)
622 port. See e.g. include/configs/versatile.h
624 CONFIG_PL011_SERIAL_RLCR
626 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
627 have separate receive and transmit line control registers. Set
628 this variable to initialize the extra register.
630 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
632 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
633 boot loader that has already initialized the UART. Define this
634 variable to flush the UART at init time.
638 Depending on board, define exactly one serial port
639 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
640 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
641 console by defining CONFIG_8xx_CONS_NONE
643 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
644 port routines must be defined elsewhere
645 (i.e. serial_init(), serial_getc(), ...)
648 Enables console device for a color framebuffer. Needs following
649 defines (cf. smiLynxEM, i8042)
650 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
652 VIDEO_HW_RECTFILL graphic chip supports
655 VIDEO_HW_BITBLT graphic chip supports
656 bit-blit (cf. smiLynxEM)
657 VIDEO_VISIBLE_COLS visible pixel columns
659 VIDEO_VISIBLE_ROWS visible pixel rows
660 VIDEO_PIXEL_SIZE bytes per pixel
661 VIDEO_DATA_FORMAT graphic data format
662 (0-5, cf. cfb_console.c)
663 VIDEO_FB_ADRS framebuffer address
664 VIDEO_KBD_INIT_FCT keyboard int fct
665 (i.e. i8042_kbd_init())
666 VIDEO_TSTC_FCT test char fct
668 VIDEO_GETC_FCT get char fct
670 CONFIG_CONSOLE_CURSOR cursor drawing on/off
671 (requires blink timer
673 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
674 CONFIG_CONSOLE_TIME display time/date info in
676 (requires CONFIG_CMD_DATE)
677 CONFIG_VIDEO_LOGO display Linux logo in
679 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
680 linux_logo.h for logo.
681 Requires CONFIG_VIDEO_LOGO
682 CONFIG_CONSOLE_EXTRA_INFO
683 additional board info beside
686 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
687 a limited number of ANSI escape sequences (cursor control,
688 erase functions and limited graphics rendition control).
690 When CONFIG_CFB_CONSOLE is defined, video console is
691 default i/o. Serial console can be forced with
692 environment 'console=serial'.
694 When CONFIG_SILENT_CONSOLE is defined, all console
695 messages (by U-Boot and Linux!) can be silenced with
696 the "silent" environment variable. See
697 doc/README.silent for more information.
700 CONFIG_BAUDRATE - in bps
701 Select one of the baudrates listed in
702 CONFIG_SYS_BAUDRATE_TABLE, see below.
703 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
705 - Console Rx buffer length
706 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
707 the maximum receive buffer length for the SMC.
708 This option is actual only for 82xx and 8xx possible.
709 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
710 must be defined, to setup the maximum idle timeout for
713 - Pre-Console Buffer:
714 Prior to the console being initialised (i.e. serial UART
715 initialised etc) all console output is silently discarded.
716 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
717 buffer any console messages prior to the console being
718 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
719 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
720 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
721 bytes are output before the console is initialised, the
722 earlier bytes are discarded.
724 'Sane' compilers will generate smaller code if
725 CONFIG_PRE_CON_BUF_SZ is a power of 2
727 - Safe printf() functions
728 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
729 the printf() functions. These are defined in
730 include/vsprintf.h and include snprintf(), vsnprintf() and
731 so on. Code size increase is approximately 300-500 bytes.
732 If this option is not given then these functions will
733 silently discard their buffer size argument - this means
734 you are not getting any overflow checking in this case.
736 - Boot Delay: CONFIG_BOOTDELAY - in seconds
737 Delay before automatically booting the default image;
738 set to -1 to disable autoboot.
739 set to -2 to autoboot with no delay and not check for abort
740 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
742 See doc/README.autoboot for these options that
743 work with CONFIG_BOOTDELAY. None are required.
744 CONFIG_BOOT_RETRY_TIME
745 CONFIG_BOOT_RETRY_MIN
746 CONFIG_AUTOBOOT_KEYED
747 CONFIG_AUTOBOOT_PROMPT
748 CONFIG_AUTOBOOT_DELAY_STR
749 CONFIG_AUTOBOOT_STOP_STR
750 CONFIG_AUTOBOOT_DELAY_STR2
751 CONFIG_AUTOBOOT_STOP_STR2
752 CONFIG_ZERO_BOOTDELAY_CHECK
753 CONFIG_RESET_TO_RETRY
757 Only needed when CONFIG_BOOTDELAY is enabled;
758 define a command string that is automatically executed
759 when no character is read on the console interface
760 within "Boot Delay" after reset.
763 This can be used to pass arguments to the bootm
764 command. The value of CONFIG_BOOTARGS goes into the
765 environment value "bootargs".
767 CONFIG_RAMBOOT and CONFIG_NFSBOOT
768 The value of these goes into the environment as
769 "ramboot" and "nfsboot" respectively, and can be used
770 as a convenience, when switching between booting from
776 When this option is #defined, the existence of the
777 environment variable "preboot" will be checked
778 immediately before starting the CONFIG_BOOTDELAY
779 countdown and/or running the auto-boot command resp.
780 entering interactive mode.
782 This feature is especially useful when "preboot" is
783 automatically generated or modified. For an example
784 see the LWMON board specific code: here "preboot" is
785 modified when the user holds down a certain
786 combination of keys on the (special) keyboard when
789 - Serial Download Echo Mode:
791 If defined to 1, all characters received during a
792 serial download (using the "loads" command) are
793 echoed back. This might be needed by some terminal
794 emulations (like "cu"), but may as well just take
795 time on others. This setting #define's the initial
796 value of the "loads_echo" environment variable.
798 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
800 Select one of the baudrates listed in
801 CONFIG_SYS_BAUDRATE_TABLE, see below.
804 Monitor commands can be included or excluded
805 from the build by using the #include files
806 <config_cmd_all.h> and #undef'ing unwanted
807 commands, or using <config_cmd_default.h>
808 and augmenting with additional #define's
811 The default command configuration includes all commands
812 except those marked below with a "*".
814 CONFIG_CMD_ASKENV * ask for env variable
815 CONFIG_CMD_BDI bdinfo
816 CONFIG_CMD_BEDBUG * Include BedBug Debugger
817 CONFIG_CMD_BMP * BMP support
818 CONFIG_CMD_BSP * Board specific commands
819 CONFIG_CMD_BOOTD bootd
820 CONFIG_CMD_CACHE * icache, dcache
821 CONFIG_CMD_CONSOLE coninfo
822 CONFIG_CMD_CRC32 * crc32
823 CONFIG_CMD_DATE * support for RTC, date/time...
824 CONFIG_CMD_DHCP * DHCP support
825 CONFIG_CMD_DIAG * Diagnostics
826 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
827 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
828 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
829 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
830 CONFIG_CMD_DTT * Digital Therm and Thermostat
831 CONFIG_CMD_ECHO echo arguments
832 CONFIG_CMD_EDITENV edit env variable
833 CONFIG_CMD_EEPROM * EEPROM read/write support
834 CONFIG_CMD_ELF * bootelf, bootvx
835 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
836 CONFIG_CMD_ENV_FLAGS * display details about env flags
837 CONFIG_CMD_EXPORTENV * export the environment
838 CONFIG_CMD_EXT2 * ext2 command support
839 CONFIG_CMD_EXT4 * ext4 command support
840 CONFIG_CMD_SAVEENV saveenv
841 CONFIG_CMD_FDC * Floppy Disk Support
842 CONFIG_CMD_FAT * FAT command support
843 CONFIG_CMD_FDOS * Dos diskette Support
844 CONFIG_CMD_FLASH flinfo, erase, protect
845 CONFIG_CMD_FPGA FPGA device initialization support
846 CONFIG_CMD_FUSE Device fuse support
847 CONFIG_CMD_GETTIME * Get time since boot
848 CONFIG_CMD_GO * the 'go' command (exec code)
849 CONFIG_CMD_GREPENV * search environment
850 CONFIG_CMD_HASH * calculate hash / digest
851 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
852 CONFIG_CMD_I2C * I2C serial bus support
853 CONFIG_CMD_IDE * IDE harddisk support
854 CONFIG_CMD_IMI iminfo
855 CONFIG_CMD_IMLS List all images found in NOR flash
856 CONFIG_CMD_IMLS_NAND List all images found in NAND flash
857 CONFIG_CMD_IMMAP * IMMR dump support
858 CONFIG_CMD_IMPORTENV * import an environment
859 CONFIG_CMD_INI * import data from an ini file into the env
860 CONFIG_CMD_IRQ * irqinfo
861 CONFIG_CMD_ITEST Integer/string test of 2 values
862 CONFIG_CMD_JFFS2 * JFFS2 Support
863 CONFIG_CMD_KGDB * kgdb
864 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
865 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
867 CONFIG_CMD_LOADB loadb
868 CONFIG_CMD_LOADS loads
869 CONFIG_CMD_MD5SUM print md5 message digest
870 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
871 CONFIG_CMD_MEMINFO * Display detailed memory information
872 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
874 CONFIG_CMD_MEMTEST mtest
875 CONFIG_CMD_MISC Misc functions like sleep etc
876 CONFIG_CMD_MMC * MMC memory mapped support
877 CONFIG_CMD_MII * MII utility commands
878 CONFIG_CMD_MTDPARTS * MTD partition support
879 CONFIG_CMD_NAND * NAND support
880 CONFIG_CMD_NET bootp, tftpboot, rarpboot
881 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
882 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
883 CONFIG_CMD_PCI * pciinfo
884 CONFIG_CMD_PCMCIA * PCMCIA support
885 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
887 CONFIG_CMD_PORTIO * Port I/O
888 CONFIG_CMD_READ * Read raw data from partition
889 CONFIG_CMD_REGINFO * Register dump
890 CONFIG_CMD_RUN run command in env variable
891 CONFIG_CMD_SANDBOX * sb command to access sandbox features
892 CONFIG_CMD_SAVES * save S record dump
893 CONFIG_CMD_SCSI * SCSI Support
894 CONFIG_CMD_SDRAM * print SDRAM configuration information
895 (requires CONFIG_CMD_I2C)
896 CONFIG_CMD_SETGETDCR Support for DCR Register access
898 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
899 CONFIG_CMD_SHA1SUM print sha1 memory digest
900 (requires CONFIG_CMD_MEMORY)
901 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
902 CONFIG_CMD_SOURCE "source" command Support
903 CONFIG_CMD_SPI * SPI serial bus support
904 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
905 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
906 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
907 CONFIG_CMD_TIMER * access to the system tick timer
908 CONFIG_CMD_USB * USB support
909 CONFIG_CMD_CDP * Cisco Discover Protocol support
910 CONFIG_CMD_MFSL * Microblaze FSL support
913 EXAMPLE: If you want all functions except of network
914 support you can write:
916 #include "config_cmd_all.h"
917 #undef CONFIG_CMD_NET
920 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
922 Note: Don't enable the "icache" and "dcache" commands
923 (configuration option CONFIG_CMD_CACHE) unless you know
924 what you (and your U-Boot users) are doing. Data
925 cache cannot be enabled on systems like the 8xx or
926 8260 (where accesses to the IMMR region must be
927 uncached), and it cannot be disabled on all other
928 systems where we (mis-) use the data cache to hold an
929 initial stack and some data.
932 XXX - this list needs to get updated!
934 - Regular expression support:
936 If this variable is defined, U-Boot is linked against
937 the SLRE (Super Light Regular Expression) library,
938 which adds regex support to some commands, as for
939 example "env grep" and "setexpr".
943 If this variable is defined, U-Boot will use a device tree
944 to configure its devices, instead of relying on statically
945 compiled #defines in the board file. This option is
946 experimental and only available on a few boards. The device
947 tree is available in the global data as gd->fdt_blob.
949 U-Boot needs to get its device tree from somewhere. This can
950 be done using one of the two options below:
953 If this variable is defined, U-Boot will embed a device tree
954 binary in its image. This device tree file should be in the
955 board directory and called <soc>-<board>.dts. The binary file
956 is then picked up in board_init_f() and made available through
957 the global data structure as gd->blob.
960 If this variable is defined, U-Boot will build a device tree
961 binary. It will be called u-boot.dtb. Architecture-specific
962 code will locate it at run-time. Generally this works by:
964 cat u-boot.bin u-boot.dtb >image.bin
966 and in fact, U-Boot does this for you, creating a file called
967 u-boot-dtb.bin which is useful in the common case. You can
968 still use the individual files if you need something more
973 If this variable is defined, it enables watchdog
974 support for the SoC. There must be support in the SoC
975 specific code for a watchdog. For the 8xx and 8260
976 CPUs, the SIU Watchdog feature is enabled in the SYPCR
977 register. When supported for a specific SoC is
978 available, then no further board specific code should
982 When using a watchdog circuitry external to the used
983 SoC, then define this variable and provide board
984 specific code for the "hw_watchdog_reset" function.
987 CONFIG_VERSION_VARIABLE
988 If this variable is defined, an environment variable
989 named "ver" is created by U-Boot showing the U-Boot
990 version as printed by the "version" command.
991 Any change to this variable will be reverted at the
996 When CONFIG_CMD_DATE is selected, the type of the RTC
997 has to be selected, too. Define exactly one of the
1000 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1001 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1002 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1003 CONFIG_RTC_MC146818 - use MC146818 RTC
1004 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1005 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1006 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1007 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1008 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1009 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1010 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1011 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1014 Note that if the RTC uses I2C, then the I2C interface
1015 must also be configured. See I2C Support, below.
1018 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1019 CONFIG_PCA953X_INFO - enable pca953x info command
1021 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1022 chip-ngpio pairs that tell the PCA953X driver the number of
1023 pins supported by a particular chip.
1025 Note that if the GPIO device uses I2C, then the I2C interface
1026 must also be configured. See I2C Support, below.
1028 - Timestamp Support:
1030 When CONFIG_TIMESTAMP is selected, the timestamp
1031 (date and time) of an image is printed by image
1032 commands like bootm or iminfo. This option is
1033 automatically enabled when you select CONFIG_CMD_DATE .
1035 - Partition Labels (disklabels) Supported:
1036 Zero or more of the following:
1037 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1038 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1039 Intel architecture, USB sticks, etc.
1040 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1041 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1042 bootloader. Note 2TB partition limit; see
1044 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1046 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1047 CONFIG_CMD_SCSI) you must configure support for at
1048 least one non-MTD partition type as well.
1051 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1052 board configurations files but used nowhere!
1054 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1055 be performed by calling the function
1056 ide_set_reset(int reset)
1057 which has to be defined in a board specific file
1062 Set this to enable ATAPI support.
1067 Set this to enable support for disks larger than 137GB
1068 Also look at CONFIG_SYS_64BIT_LBA.
1069 Whithout these , LBA48 support uses 32bit variables and will 'only'
1070 support disks up to 2.1TB.
1072 CONFIG_SYS_64BIT_LBA:
1073 When enabled, makes the IDE subsystem use 64bit sector addresses.
1077 At the moment only there is only support for the
1078 SYM53C8XX SCSI controller; define
1079 CONFIG_SCSI_SYM53C8XX to enable it.
1081 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1082 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1083 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1084 maximum numbers of LUNs, SCSI ID's and target
1086 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1088 The environment variable 'scsidevs' is set to the number of
1089 SCSI devices found during the last scan.
1091 - NETWORK Support (PCI):
1093 Support for Intel 8254x/8257x gigabit chips.
1096 Utility code for direct access to the SPI bus on Intel 8257x.
1097 This does not do anything useful unless you set at least one
1098 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1100 CONFIG_E1000_SPI_GENERIC
1101 Allow generic access to the SPI bus on the Intel 8257x, for
1102 example with the "sspi" command.
1105 Management command for E1000 devices. When used on devices
1106 with SPI support you can reprogram the EEPROM from U-Boot.
1108 CONFIG_E1000_FALLBACK_MAC
1109 default MAC for empty EEPROM after production.
1112 Support for Intel 82557/82559/82559ER chips.
1113 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1114 write routine for first time initialisation.
1117 Support for Digital 2114x chips.
1118 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1119 modem chip initialisation (KS8761/QS6611).
1122 Support for National dp83815 chips.
1125 Support for National dp8382[01] gigabit chips.
1127 - NETWORK Support (other):
1129 CONFIG_DRIVER_AT91EMAC
1130 Support for AT91RM9200 EMAC.
1133 Define this to use reduced MII inteface
1135 CONFIG_DRIVER_AT91EMAC_QUIET
1136 If this defined, the driver is quiet.
1137 The driver doen't show link status messages.
1139 CONFIG_CALXEDA_XGMAC
1140 Support for the Calxeda XGMAC device
1143 Support for SMSC's LAN91C96 chips.
1145 CONFIG_LAN91C96_BASE
1146 Define this to hold the physical address
1147 of the LAN91C96's I/O space
1149 CONFIG_LAN91C96_USE_32_BIT
1150 Define this to enable 32 bit addressing
1153 Support for SMSC's LAN91C111 chip
1155 CONFIG_SMC91111_BASE
1156 Define this to hold the physical address
1157 of the device (I/O space)
1159 CONFIG_SMC_USE_32_BIT
1160 Define this if data bus is 32 bits
1162 CONFIG_SMC_USE_IOFUNCS
1163 Define this to use i/o functions instead of macros
1164 (some hardware wont work with macros)
1166 CONFIG_DRIVER_TI_EMAC
1167 Support for davinci emac
1169 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1170 Define this if you have more then 3 PHYs.
1173 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1175 CONFIG_FTGMAC100_EGIGA
1176 Define this to use GE link update with gigabit PHY.
1177 Define this if FTGMAC100 is connected to gigabit PHY.
1178 If your system has 10/100 PHY only, it might not occur
1179 wrong behavior. Because PHY usually return timeout or
1180 useless data when polling gigabit status and gigabit
1181 control registers. This behavior won't affect the
1182 correctnessof 10/100 link speed update.
1185 Support for SMSC's LAN911x and LAN921x chips
1188 Define this to hold the physical address
1189 of the device (I/O space)
1191 CONFIG_SMC911X_32_BIT
1192 Define this if data bus is 32 bits
1194 CONFIG_SMC911X_16_BIT
1195 Define this if data bus is 16 bits. If your processor
1196 automatically converts one 32 bit word to two 16 bit
1197 words you may also try CONFIG_SMC911X_32_BIT.
1200 Support for Renesas on-chip Ethernet controller
1202 CONFIG_SH_ETHER_USE_PORT
1203 Define the number of ports to be used
1205 CONFIG_SH_ETHER_PHY_ADDR
1206 Define the ETH PHY's address
1208 CONFIG_SH_ETHER_CACHE_WRITEBACK
1209 If this option is set, the driver enables cache flush.
1213 Support TPM devices.
1216 Support for i2c bus TPM devices. Only one device
1217 per system is supported at this time.
1219 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1220 Define the the i2c bus number for the TPM device
1222 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1223 Define the TPM's address on the i2c bus
1225 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1226 Define the burst count bytes upper limit
1229 Support for generic parallel port TPM devices. Only one device
1230 per system is supported at this time.
1232 CONFIG_TPM_TIS_BASE_ADDRESS
1233 Base address where the generic TPM device is mapped
1234 to. Contemporary x86 systems usually map it at
1238 At the moment only the UHCI host controller is
1239 supported (PIP405, MIP405, MPC5200); define
1240 CONFIG_USB_UHCI to enable it.
1241 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1242 and define CONFIG_USB_STORAGE to enable the USB
1245 Supported are USB Keyboards and USB Floppy drives
1247 MPC5200 USB requires additional defines:
1249 for 528 MHz Clock: 0x0001bbbb
1253 for differential drivers: 0x00001000
1254 for single ended drivers: 0x00005000
1255 for differential drivers on PSC3: 0x00000100
1256 for single ended drivers on PSC3: 0x00004100
1257 CONFIG_SYS_USB_EVENT_POLL
1258 May be defined to allow interrupt polling
1259 instead of using asynchronous interrupts
1261 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1262 txfilltuning field in the EHCI controller on reset.
1264 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1265 interval for usb hub power-on delay.(minimum 100msec)
1268 Define the below if you wish to use the USB console.
1269 Once firmware is rebuilt from a serial console issue the
1270 command "setenv stdin usbtty; setenv stdout usbtty" and
1271 attach your USB cable. The Unix command "dmesg" should print
1272 it has found a new device. The environment variable usbtty
1273 can be set to gserial or cdc_acm to enable your device to
1274 appear to a USB host as a Linux gserial device or a
1275 Common Device Class Abstract Control Model serial device.
1276 If you select usbtty = gserial you should be able to enumerate
1278 # modprobe usbserial vendor=0xVendorID product=0xProductID
1279 else if using cdc_acm, simply setting the environment
1280 variable usbtty to be cdc_acm should suffice. The following
1281 might be defined in YourBoardName.h
1284 Define this to build a UDC device
1287 Define this to have a tty type of device available to
1288 talk to the UDC device
1291 Define this to enable the high speed support for usb
1292 device and usbtty. If this feature is enabled, a routine
1293 int is_usbd_high_speed(void)
1294 also needs to be defined by the driver to dynamically poll
1295 whether the enumeration has succeded at high speed or full
1298 CONFIG_SYS_CONSOLE_IS_IN_ENV
1299 Define this if you want stdin, stdout &/or stderr to
1303 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1304 Derive USB clock from external clock "blah"
1305 - CONFIG_SYS_USB_EXTC_CLK 0x02
1307 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1308 Derive USB clock from brgclk
1309 - CONFIG_SYS_USB_BRG_CLK 0x04
1311 If you have a USB-IF assigned VendorID then you may wish to
1312 define your own vendor specific values either in BoardName.h
1313 or directly in usbd_vendor_info.h. If you don't define
1314 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1315 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1316 should pretend to be a Linux device to it's target host.
1318 CONFIG_USBD_MANUFACTURER
1319 Define this string as the name of your company for
1320 - CONFIG_USBD_MANUFACTURER "my company"
1322 CONFIG_USBD_PRODUCT_NAME
1323 Define this string as the name of your product
1324 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1326 CONFIG_USBD_VENDORID
1327 Define this as your assigned Vendor ID from the USB
1328 Implementors Forum. This *must* be a genuine Vendor ID
1329 to avoid polluting the USB namespace.
1330 - CONFIG_USBD_VENDORID 0xFFFF
1332 CONFIG_USBD_PRODUCTID
1333 Define this as the unique Product ID
1335 - CONFIG_USBD_PRODUCTID 0xFFFF
1337 - ULPI Layer Support:
1338 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1339 the generic ULPI layer. The generic layer accesses the ULPI PHY
1340 via the platform viewport, so you need both the genric layer and
1341 the viewport enabled. Currently only Chipidea/ARC based
1342 viewport is supported.
1343 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1344 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1345 If your ULPI phy needs a different reference clock than the
1346 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1347 the appropriate value in Hz.
1350 The MMC controller on the Intel PXA is supported. To
1351 enable this define CONFIG_MMC. The MMC can be
1352 accessed from the boot prompt by mapping the device
1353 to physical memory similar to flash. Command line is
1354 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1355 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1358 Support for Renesas on-chip MMCIF controller
1360 CONFIG_SH_MMCIF_ADDR
1361 Define the base address of MMCIF registers
1364 Define the clock frequency for MMCIF
1366 - USB Device Firmware Update (DFU) class support:
1368 This enables the USB portion of the DFU USB class
1371 This enables the command "dfu" which is used to have
1372 U-Boot create a DFU class device via USB. This command
1373 requires that the "dfu_alt_info" environment variable be
1374 set and define the alt settings to expose to the host.
1377 This enables support for exposing (e)MMC devices via DFU.
1380 This enables support for exposing NAND devices via DFU.
1382 CONFIG_SYS_DFU_MAX_FILE_SIZE
1383 When updating files rather than the raw storage device,
1384 we use a static buffer to copy the file into and then write
1385 the buffer once we've been given the whole file. Define
1386 this to the maximum filesize (in bytes) for the buffer.
1387 Default is 4 MiB if undefined.
1389 - Journaling Flash filesystem support:
1390 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1391 CONFIG_JFFS2_NAND_DEV
1392 Define these for a default partition on a NAND device
1394 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1395 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1396 Define these for a default partition on a NOR device
1398 CONFIG_SYS_JFFS_CUSTOM_PART
1399 Define this to create an own partition. You have to provide a
1400 function struct part_info* jffs2_part_info(int part_num)
1402 If you define only one JFFS2 partition you may also want to
1403 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1404 to disable the command chpart. This is the default when you
1405 have not defined a custom partition
1407 - FAT(File Allocation Table) filesystem write function support:
1410 Define this to enable support for saving memory data as a
1411 file in FAT formatted partition.
1413 This will also enable the command "fatwrite" enabling the
1414 user to write files to FAT.
1416 CBFS (Coreboot Filesystem) support
1419 Define this to enable support for reading from a Coreboot
1420 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1426 Define this to enable standard (PC-Style) keyboard
1430 Standard PC keyboard driver with US (is default) and
1431 GERMAN key layout (switch via environment 'keymap=de') support.
1432 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1433 for cfb_console. Supports cursor blinking.
1438 Define this to enable video support (for output to
1441 CONFIG_VIDEO_CT69000
1443 Enable Chips & Technologies 69000 Video chip
1445 CONFIG_VIDEO_SMI_LYNXEM
1446 Enable Silicon Motion SMI 712/710/810 Video chip. The
1447 video output is selected via environment 'videoout'
1448 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1451 For the CT69000 and SMI_LYNXEM drivers, videomode is
1452 selected via environment 'videomode'. Two different ways
1454 - "videomode=num" 'num' is a standard LiLo mode numbers.
1455 Following standard modes are supported (* is default):
1457 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1458 -------------+---------------------------------------------
1459 8 bits | 0x301* 0x303 0x305 0x161 0x307
1460 15 bits | 0x310 0x313 0x316 0x162 0x319
1461 16 bits | 0x311 0x314 0x317 0x163 0x31A
1462 24 bits | 0x312 0x315 0x318 ? 0x31B
1463 -------------+---------------------------------------------
1464 (i.e. setenv videomode 317; saveenv; reset;)
1466 - "videomode=bootargs" all the video parameters are parsed
1467 from the bootargs. (See drivers/video/videomodes.c)
1470 CONFIG_VIDEO_SED13806
1471 Enable Epson SED13806 driver. This driver supports 8bpp
1472 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1473 or CONFIG_VIDEO_SED13806_16BPP
1476 Enable the Freescale DIU video driver. Reference boards for
1477 SOCs that have a DIU should define this macro to enable DIU
1478 support, and should also define these other macros:
1484 CONFIG_VIDEO_SW_CURSOR
1485 CONFIG_VGA_AS_SINGLE_DEVICE
1487 CONFIG_VIDEO_BMP_LOGO
1489 The DIU driver will look for the 'video-mode' environment
1490 variable, and if defined, enable the DIU as a console during
1491 boot. See the documentation file README.video for a
1492 description of this variable.
1496 Enable the VGA video / BIOS for x86. The alternative if you
1497 are using coreboot is to use the coreboot frame buffer
1504 Define this to enable a custom keyboard support.
1505 This simply calls drv_keyboard_init() which must be
1506 defined in your board-specific files.
1507 The only board using this so far is RBC823.
1509 - LCD Support: CONFIG_LCD
1511 Define this to enable LCD support (for output to LCD
1512 display); also select one of the supported displays
1513 by defining one of these:
1517 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1519 CONFIG_NEC_NL6448AC33:
1521 NEC NL6448AC33-18. Active, color, single scan.
1523 CONFIG_NEC_NL6448BC20
1525 NEC NL6448BC20-08. 6.5", 640x480.
1526 Active, color, single scan.
1528 CONFIG_NEC_NL6448BC33_54
1530 NEC NL6448BC33-54. 10.4", 640x480.
1531 Active, color, single scan.
1535 Sharp 320x240. Active, color, single scan.
1536 It isn't 16x9, and I am not sure what it is.
1538 CONFIG_SHARP_LQ64D341
1540 Sharp LQ64D341 display, 640x480.
1541 Active, color, single scan.
1545 HLD1045 display, 640x480.
1546 Active, color, single scan.
1550 Optrex CBL50840-2 NF-FW 99 22 M5
1552 Hitachi LMG6912RPFC-00T
1556 320x240. Black & white.
1558 Normally display is black on white background; define
1559 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1561 CONFIG_LCD_ALIGNMENT
1563 Normally the LCD is page-aligned (tyically 4KB). If this is
1564 defined then the LCD will be aligned to this value instead.
1565 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1566 here, since it is cheaper to change data cache settings on
1567 a per-section basis.
1569 CONFIG_CONSOLE_SCROLL_LINES
1571 When the console need to be scrolled, this is the number of
1572 lines to scroll by. It defaults to 1. Increasing this makes
1573 the console jump but can help speed up operation when scrolling
1578 Support drawing of RLE8-compressed bitmaps on the LCD.
1582 Enables an 'i2c edid' command which can read EDID
1583 information over I2C from an attached LCD display.
1585 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1587 If this option is set, the environment is checked for
1588 a variable "splashimage". If found, the usual display
1589 of logo, copyright and system information on the LCD
1590 is suppressed and the BMP image at the address
1591 specified in "splashimage" is loaded instead. The
1592 console is redirected to the "nulldev", too. This
1593 allows for a "silent" boot where a splash screen is
1594 loaded very quickly after power-on.
1596 CONFIG_SPLASHIMAGE_GUARD
1598 If this option is set, then U-Boot will prevent the environment
1599 variable "splashimage" from being set to a problematic address
1600 (see README.displaying-bmps and README.arm-unaligned-accesses).
1601 This option is useful for targets where, due to alignment
1602 restrictions, an improperly aligned BMP image will cause a data
1603 abort. If you think you will not have problems with unaligned
1604 accesses (for example because your toolchain prevents them)
1605 there is no need to set this option.
1607 CONFIG_SPLASH_SCREEN_ALIGN
1609 If this option is set the splash image can be freely positioned
1610 on the screen. Environment variable "splashpos" specifies the
1611 position as "x,y". If a positive number is given it is used as
1612 number of pixel from left/top. If a negative number is given it
1613 is used as number of pixel from right/bottom. You can also
1614 specify 'm' for centering the image.
1617 setenv splashpos m,m
1618 => image at center of screen
1620 setenv splashpos 30,20
1621 => image at x = 30 and y = 20
1623 setenv splashpos -10,m
1624 => vertically centered image
1625 at x = dspWidth - bmpWidth - 9
1627 CONFIG_SPLASH_SCREEN_PREPARE
1629 If this option is set then the board_splash_screen_prepare()
1630 function, which must be defined in your code, is called as part
1631 of the splash screen display sequence. It gives the board an
1632 opportunity to prepare the splash image data before it is
1633 processed and sent to the frame buffer by U-Boot.
1635 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1637 If this option is set, additionally to standard BMP
1638 images, gzipped BMP images can be displayed via the
1639 splashscreen support or the bmp command.
1641 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1643 If this option is set, 8-bit RLE compressed BMP images
1644 can be displayed via the splashscreen support or the
1647 - Do compresssing for memory range:
1650 If this option is set, it would use zlib deflate method
1651 to compress the specified memory at its best effort.
1653 - Compression support:
1656 If this option is set, support for bzip2 compressed
1657 images is included. If not, only uncompressed and gzip
1658 compressed images are supported.
1660 NOTE: the bzip2 algorithm requires a lot of RAM, so
1661 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1666 If this option is set, support for lzma compressed
1669 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1670 requires an amount of dynamic memory that is given by the
1673 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1675 Where lc and lp stand for, respectively, Literal context bits
1676 and Literal pos bits.
1678 This value is upper-bounded by 14MB in the worst case. Anyway,
1679 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1680 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1681 a very small buffer.
1683 Use the lzmainfo tool to determinate the lc and lp values and
1684 then calculate the amount of needed dynamic memory (ensuring
1685 the appropriate CONFIG_SYS_MALLOC_LEN value).
1690 The address of PHY on MII bus.
1692 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1694 The clock frequency of the MII bus
1698 If this option is set, support for speed/duplex
1699 detection of gigabit PHY is included.
1701 CONFIG_PHY_RESET_DELAY
1703 Some PHY like Intel LXT971A need extra delay after
1704 reset before any MII register access is possible.
1705 For such PHY, set this option to the usec delay
1706 required. (minimum 300usec for LXT971A)
1708 CONFIG_PHY_CMD_DELAY (ppc4xx)
1710 Some PHY like Intel LXT971A need extra delay after
1711 command issued before MII status register can be read
1721 Define a default value for Ethernet address to use
1722 for the respective Ethernet interface, in case this
1723 is not determined automatically.
1728 Define a default value for the IP address to use for
1729 the default Ethernet interface, in case this is not
1730 determined through e.g. bootp.
1731 (Environment variable "ipaddr")
1733 - Server IP address:
1736 Defines a default value for the IP address of a TFTP
1737 server to contact when using the "tftboot" command.
1738 (Environment variable "serverip")
1740 CONFIG_KEEP_SERVERADDR
1742 Keeps the server's MAC address, in the env 'serveraddr'
1743 for passing to bootargs (like Linux's netconsole option)
1745 - Gateway IP address:
1748 Defines a default value for the IP address of the
1749 default router where packets to other networks are
1751 (Environment variable "gatewayip")
1756 Defines a default value for the subnet mask (or
1757 routing prefix) which is used to determine if an IP
1758 address belongs to the local subnet or needs to be
1759 forwarded through a router.
1760 (Environment variable "netmask")
1762 - Multicast TFTP Mode:
1765 Defines whether you want to support multicast TFTP as per
1766 rfc-2090; for example to work with atftp. Lets lots of targets
1767 tftp down the same boot image concurrently. Note: the Ethernet
1768 driver in use must provide a function: mcast() to join/leave a
1771 - BOOTP Recovery Mode:
1772 CONFIG_BOOTP_RANDOM_DELAY
1774 If you have many targets in a network that try to
1775 boot using BOOTP, you may want to avoid that all
1776 systems send out BOOTP requests at precisely the same
1777 moment (which would happen for instance at recovery
1778 from a power failure, when all systems will try to
1779 boot, thus flooding the BOOTP server. Defining
1780 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1781 inserted before sending out BOOTP requests. The
1782 following delays are inserted then:
1784 1st BOOTP request: delay 0 ... 1 sec
1785 2nd BOOTP request: delay 0 ... 2 sec
1786 3rd BOOTP request: delay 0 ... 4 sec
1788 BOOTP requests: delay 0 ... 8 sec
1790 - DHCP Advanced Options:
1791 You can fine tune the DHCP functionality by defining
1792 CONFIG_BOOTP_* symbols:
1794 CONFIG_BOOTP_SUBNETMASK
1795 CONFIG_BOOTP_GATEWAY
1796 CONFIG_BOOTP_HOSTNAME
1797 CONFIG_BOOTP_NISDOMAIN
1798 CONFIG_BOOTP_BOOTPATH
1799 CONFIG_BOOTP_BOOTFILESIZE
1802 CONFIG_BOOTP_SEND_HOSTNAME
1803 CONFIG_BOOTP_NTPSERVER
1804 CONFIG_BOOTP_TIMEOFFSET
1805 CONFIG_BOOTP_VENDOREX
1806 CONFIG_BOOTP_MAY_FAIL
1808 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1809 environment variable, not the BOOTP server.
1811 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1812 after the configured retry count, the call will fail
1813 instead of starting over. This can be used to fail over
1814 to Link-local IP address configuration if the DHCP server
1817 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1818 serverip from a DHCP server, it is possible that more
1819 than one DNS serverip is offered to the client.
1820 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1821 serverip will be stored in the additional environment
1822 variable "dnsip2". The first DNS serverip is always
1823 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1826 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1827 to do a dynamic update of a DNS server. To do this, they
1828 need the hostname of the DHCP requester.
1829 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1830 of the "hostname" environment variable is passed as
1831 option 12 to the DHCP server.
1833 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1835 A 32bit value in microseconds for a delay between
1836 receiving a "DHCP Offer" and sending the "DHCP Request".
1837 This fixes a problem with certain DHCP servers that don't
1838 respond 100% of the time to a "DHCP request". E.g. On an
1839 AT91RM9200 processor running at 180MHz, this delay needed
1840 to be *at least* 15,000 usec before a Windows Server 2003
1841 DHCP server would reply 100% of the time. I recommend at
1842 least 50,000 usec to be safe. The alternative is to hope
1843 that one of the retries will be successful but note that
1844 the DHCP timeout and retry process takes a longer than
1847 - Link-local IP address negotiation:
1848 Negotiate with other link-local clients on the local network
1849 for an address that doesn't require explicit configuration.
1850 This is especially useful if a DHCP server cannot be guaranteed
1851 to exist in all environments that the device must operate.
1853 See doc/README.link-local for more information.
1856 CONFIG_CDP_DEVICE_ID
1858 The device id used in CDP trigger frames.
1860 CONFIG_CDP_DEVICE_ID_PREFIX
1862 A two character string which is prefixed to the MAC address
1867 A printf format string which contains the ascii name of
1868 the port. Normally is set to "eth%d" which sets
1869 eth0 for the first Ethernet, eth1 for the second etc.
1871 CONFIG_CDP_CAPABILITIES
1873 A 32bit integer which indicates the device capabilities;
1874 0x00000010 for a normal host which does not forwards.
1878 An ascii string containing the version of the software.
1882 An ascii string containing the name of the platform.
1886 A 32bit integer sent on the trigger.
1888 CONFIG_CDP_POWER_CONSUMPTION
1890 A 16bit integer containing the power consumption of the
1891 device in .1 of milliwatts.
1893 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1895 A byte containing the id of the VLAN.
1897 - Status LED: CONFIG_STATUS_LED
1899 Several configurations allow to display the current
1900 status using a LED. For instance, the LED will blink
1901 fast while running U-Boot code, stop blinking as
1902 soon as a reply to a BOOTP request was received, and
1903 start blinking slow once the Linux kernel is running
1904 (supported by a status LED driver in the Linux
1905 kernel). Defining CONFIG_STATUS_LED enables this
1908 - CAN Support: CONFIG_CAN_DRIVER
1910 Defining CONFIG_CAN_DRIVER enables CAN driver support
1911 on those systems that support this (optional)
1912 feature, like the TQM8xxL modules.
1914 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1916 These enable I2C serial bus commands. Defining either of
1917 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1918 include the appropriate I2C driver for the selected CPU.
1920 This will allow you to use i2c commands at the u-boot
1921 command line (as long as you set CONFIG_CMD_I2C in
1922 CONFIG_COMMANDS) and communicate with i2c based realtime
1923 clock chips. See common/cmd_i2c.c for a description of the
1924 command line interface.
1926 CONFIG_HARD_I2C selects a hardware I2C controller.
1928 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1929 bit-banging) driver instead of CPM or similar hardware
1932 There are several other quantities that must also be
1933 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1935 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1936 to be the frequency (in Hz) at which you wish your i2c bus
1937 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1938 the CPU's i2c node address).
1940 Now, the u-boot i2c code for the mpc8xx
1941 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1942 and so its address should therefore be cleared to 0 (See,
1943 eg, MPC823e User's Manual p.16-473). So, set
1944 CONFIG_SYS_I2C_SLAVE to 0.
1946 CONFIG_SYS_I2C_INIT_MPC5XXX
1948 When a board is reset during an i2c bus transfer
1949 chips might think that the current transfer is still
1950 in progress. Reset the slave devices by sending start
1951 commands until the slave device responds.
1953 That's all that's required for CONFIG_HARD_I2C.
1955 If you use the software i2c interface (CONFIG_SOFT_I2C)
1956 then the following macros need to be defined (examples are
1957 from include/configs/lwmon.h):
1961 (Optional). Any commands necessary to enable the I2C
1962 controller or configure ports.
1964 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1968 (Only for MPC8260 CPU). The I/O port to use (the code
1969 assumes both bits are on the same port). Valid values
1970 are 0..3 for ports A..D.
1974 The code necessary to make the I2C data line active
1975 (driven). If the data line is open collector, this
1978 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1982 The code necessary to make the I2C data line tri-stated
1983 (inactive). If the data line is open collector, this
1986 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1990 Code that returns true if the I2C data line is high,
1993 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1997 If <bit> is true, sets the I2C data line high. If it
1998 is false, it clears it (low).
2000 eg: #define I2C_SDA(bit) \
2001 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2002 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2006 If <bit> is true, sets the I2C clock line high. If it
2007 is false, it clears it (low).
2009 eg: #define I2C_SCL(bit) \
2010 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2011 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2015 This delay is invoked four times per clock cycle so this
2016 controls the rate of data transfer. The data rate thus
2017 is 1 / (I2C_DELAY * 4). Often defined to be something
2020 #define I2C_DELAY udelay(2)
2022 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2024 If your arch supports the generic GPIO framework (asm/gpio.h),
2025 then you may alternatively define the two GPIOs that are to be
2026 used as SCL / SDA. Any of the previous I2C_xxx macros will
2027 have GPIO-based defaults assigned to them as appropriate.
2029 You should define these to the GPIO value as given directly to
2030 the generic GPIO functions.
2032 CONFIG_SYS_I2C_INIT_BOARD
2034 When a board is reset during an i2c bus transfer
2035 chips might think that the current transfer is still
2036 in progress. On some boards it is possible to access
2037 the i2c SCLK line directly, either by using the
2038 processor pin as a GPIO or by having a second pin
2039 connected to the bus. If this option is defined a
2040 custom i2c_init_board() routine in boards/xxx/board.c
2041 is run early in the boot sequence.
2043 CONFIG_SYS_I2C_BOARD_LATE_INIT
2045 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2046 defined a custom i2c_board_late_init() routine in
2047 boards/xxx/board.c is run AFTER the operations in i2c_init()
2048 is completed. This callpoint can be used to unreset i2c bus
2049 using CPU i2c controller register accesses for CPUs whose i2c
2050 controller provide such a method. It is called at the end of
2051 i2c_init() to allow i2c_init operations to setup the i2c bus
2052 controller on the CPU (e.g. setting bus speed & slave address).
2054 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2056 This option enables configuration of bi_iic_fast[] flags
2057 in u-boot bd_info structure based on u-boot environment
2058 variable "i2cfast". (see also i2cfast)
2060 CONFIG_I2C_MULTI_BUS
2062 This option allows the use of multiple I2C buses, each of which
2063 must have a controller. At any point in time, only one bus is
2064 active. To switch to a different bus, use the 'i2c dev' command.
2065 Note that bus numbering is zero-based.
2067 CONFIG_SYS_I2C_NOPROBES
2069 This option specifies a list of I2C devices that will be skipped
2070 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2071 is set, specify a list of bus-device pairs. Otherwise, specify
2072 a 1D array of device addresses
2075 #undef CONFIG_I2C_MULTI_BUS
2076 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2078 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2080 #define CONFIG_I2C_MULTI_BUS
2081 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2083 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2085 CONFIG_SYS_SPD_BUS_NUM
2087 If defined, then this indicates the I2C bus number for DDR SPD.
2088 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2090 CONFIG_SYS_RTC_BUS_NUM
2092 If defined, then this indicates the I2C bus number for the RTC.
2093 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2095 CONFIG_SYS_DTT_BUS_NUM
2097 If defined, then this indicates the I2C bus number for the DTT.
2098 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2100 CONFIG_SYS_I2C_DTT_ADDR:
2102 If defined, specifies the I2C address of the DTT device.
2103 If not defined, then U-Boot uses predefined value for
2104 specified DTT device.
2108 Define this option if you want to use Freescale's I2C driver in
2109 drivers/i2c/fsl_i2c.c.
2113 Define this option if you have I2C devices reached over 1 .. n
2114 I2C Muxes like the pca9544a. This option addes a new I2C
2115 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2116 new I2C Bus to the existing I2C Busses. If you select the
2117 new Bus with "i2c dev", u-bbot sends first the commandos for
2118 the muxes to activate this new "bus".
2120 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2124 Adding a new I2C Bus reached over 2 pca9544a muxes
2125 The First mux with address 70 and channel 6
2126 The Second mux with address 71 and channel 4
2128 => i2c bus pca9544a:70:6:pca9544a:71:4
2130 Use the "i2c bus" command without parameter, to get a list
2131 of I2C Busses with muxes:
2134 Busses reached over muxes:
2136 reached over Mux(es):
2139 reached over Mux(es):
2144 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2145 u-boot first sends the command to the mux@70 to enable
2146 channel 6, and then the command to the mux@71 to enable
2149 After that, you can use the "normal" i2c commands as
2150 usual to communicate with your I2C devices behind
2153 This option is actually implemented for the bitbanging
2154 algorithm in common/soft_i2c.c and for the Hardware I2C
2155 Bus on the MPC8260. But it should be not so difficult
2156 to add this option to other architectures.
2158 CONFIG_SOFT_I2C_READ_REPEATED_START
2160 defining this will force the i2c_read() function in
2161 the soft_i2c driver to perform an I2C repeated start
2162 between writing the address pointer and reading the
2163 data. If this define is omitted the default behaviour
2164 of doing a stop-start sequence will be used. Most I2C
2165 devices can use either method, but some require one or
2168 - SPI Support: CONFIG_SPI
2170 Enables SPI driver (so far only tested with
2171 SPI EEPROM, also an instance works with Crystal A/D and
2172 D/As on the SACSng board)
2176 Enables the driver for SPI controller on SuperH. Currently
2177 only SH7757 is supported.
2181 Enables extended (16-bit) SPI EEPROM addressing.
2182 (symmetrical to CONFIG_I2C_X)
2186 Enables a software (bit-bang) SPI driver rather than
2187 using hardware support. This is a general purpose
2188 driver that only requires three general I/O port pins
2189 (two outputs, one input) to function. If this is
2190 defined, the board configuration must define several
2191 SPI configuration items (port pins to use, etc). For
2192 an example, see include/configs/sacsng.h.
2196 Enables a hardware SPI driver for general-purpose reads
2197 and writes. As with CONFIG_SOFT_SPI, the board configuration
2198 must define a list of chip-select function pointers.
2199 Currently supported on some MPC8xxx processors. For an
2200 example, see include/configs/mpc8349emds.h.
2204 Enables the driver for the SPI controllers on i.MX and MXC
2205 SoCs. Currently i.MX31/35/51 are supported.
2207 - FPGA Support: CONFIG_FPGA
2209 Enables FPGA subsystem.
2211 CONFIG_FPGA_<vendor>
2213 Enables support for specific chip vendors.
2216 CONFIG_FPGA_<family>
2218 Enables support for FPGA family.
2219 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2223 Specify the number of FPGA devices to support.
2225 CONFIG_SYS_FPGA_PROG_FEEDBACK
2227 Enable printing of hash marks during FPGA configuration.
2229 CONFIG_SYS_FPGA_CHECK_BUSY
2231 Enable checks on FPGA configuration interface busy
2232 status by the configuration function. This option
2233 will require a board or device specific function to
2238 If defined, a function that provides delays in the FPGA
2239 configuration driver.
2241 CONFIG_SYS_FPGA_CHECK_CTRLC
2242 Allow Control-C to interrupt FPGA configuration
2244 CONFIG_SYS_FPGA_CHECK_ERROR
2246 Check for configuration errors during FPGA bitfile
2247 loading. For example, abort during Virtex II
2248 configuration if the INIT_B line goes low (which
2249 indicated a CRC error).
2251 CONFIG_SYS_FPGA_WAIT_INIT
2253 Maximum time to wait for the INIT_B line to deassert
2254 after PROB_B has been deasserted during a Virtex II
2255 FPGA configuration sequence. The default time is 500
2258 CONFIG_SYS_FPGA_WAIT_BUSY
2260 Maximum time to wait for BUSY to deassert during
2261 Virtex II FPGA configuration. The default is 5 ms.
2263 CONFIG_SYS_FPGA_WAIT_CONFIG
2265 Time to wait after FPGA configuration. The default is
2268 - Configuration Management:
2271 If defined, this string will be added to the U-Boot
2272 version information (U_BOOT_VERSION)
2274 - Vendor Parameter Protection:
2276 U-Boot considers the values of the environment
2277 variables "serial#" (Board Serial Number) and
2278 "ethaddr" (Ethernet Address) to be parameters that
2279 are set once by the board vendor / manufacturer, and
2280 protects these variables from casual modification by
2281 the user. Once set, these variables are read-only,
2282 and write or delete attempts are rejected. You can
2283 change this behaviour:
2285 If CONFIG_ENV_OVERWRITE is #defined in your config
2286 file, the write protection for vendor parameters is
2287 completely disabled. Anybody can change or delete
2290 Alternatively, if you #define _both_ CONFIG_ETHADDR
2291 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2292 Ethernet address is installed in the environment,
2293 which can be changed exactly ONCE by the user. [The
2294 serial# is unaffected by this, i. e. it remains
2297 The same can be accomplished in a more flexible way
2298 for any variable by configuring the type of access
2299 to allow for those variables in the ".flags" variable
2300 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2305 Define this variable to enable the reservation of
2306 "protected RAM", i. e. RAM which is not overwritten
2307 by U-Boot. Define CONFIG_PRAM to hold the number of
2308 kB you want to reserve for pRAM. You can overwrite
2309 this default value by defining an environment
2310 variable "pram" to the number of kB you want to
2311 reserve. Note that the board info structure will
2312 still show the full amount of RAM. If pRAM is
2313 reserved, a new environment variable "mem" will
2314 automatically be defined to hold the amount of
2315 remaining RAM in a form that can be passed as boot
2316 argument to Linux, for instance like that:
2318 setenv bootargs ... mem=\${mem}
2321 This way you can tell Linux not to use this memory,
2322 either, which results in a memory region that will
2323 not be affected by reboots.
2325 *WARNING* If your board configuration uses automatic
2326 detection of the RAM size, you must make sure that
2327 this memory test is non-destructive. So far, the
2328 following board configurations are known to be
2331 IVMS8, IVML24, SPD8xx, TQM8xxL,
2332 HERMES, IP860, RPXlite, LWMON,
2335 - Access to physical memory region (> 4GB)
2336 Some basic support is provided for operations on memory not
2337 normally accessible to U-Boot - e.g. some architectures
2338 support access to more than 4GB of memory on 32-bit
2339 machines using physical address extension or similar.
2340 Define CONFIG_PHYSMEM to access this basic support, which
2341 currently only supports clearing the memory.
2346 Define this variable to stop the system in case of a
2347 fatal error, so that you have to reset it manually.
2348 This is probably NOT a good idea for an embedded
2349 system where you want the system to reboot
2350 automatically as fast as possible, but it may be
2351 useful during development since you can try to debug
2352 the conditions that lead to the situation.
2354 CONFIG_NET_RETRY_COUNT
2356 This variable defines the number of retries for
2357 network operations like ARP, RARP, TFTP, or BOOTP
2358 before giving up the operation. If not defined, a
2359 default value of 5 is used.
2363 Timeout waiting for an ARP reply in milliseconds.
2367 Timeout in milliseconds used in NFS protocol.
2368 If you encounter "ERROR: Cannot umount" in nfs command,
2369 try longer timeout such as
2370 #define CONFIG_NFS_TIMEOUT 10000UL
2372 - Command Interpreter:
2373 CONFIG_AUTO_COMPLETE
2375 Enable auto completion of commands using TAB.
2377 Note that this feature has NOT been implemented yet
2378 for the "hush" shell.
2381 CONFIG_SYS_HUSH_PARSER
2383 Define this variable to enable the "hush" shell (from
2384 Busybox) as command line interpreter, thus enabling
2385 powerful command line syntax like
2386 if...then...else...fi conditionals or `&&' and '||'
2387 constructs ("shell scripts").
2389 If undefined, you get the old, much simpler behaviour
2390 with a somewhat smaller memory footprint.
2393 CONFIG_SYS_PROMPT_HUSH_PS2
2395 This defines the secondary prompt string, which is
2396 printed when the command interpreter needs more input
2397 to complete a command. Usually "> ".
2401 In the current implementation, the local variables
2402 space and global environment variables space are
2403 separated. Local variables are those you define by
2404 simply typing `name=value'. To access a local
2405 variable later on, you have write `$name' or
2406 `${name}'; to execute the contents of a variable
2407 directly type `$name' at the command prompt.
2409 Global environment variables are those you use
2410 setenv/printenv to work with. To run a command stored
2411 in such a variable, you need to use the run command,
2412 and you must not use the '$' sign to access them.
2414 To store commands and special characters in a
2415 variable, please use double quotation marks
2416 surrounding the whole text of the variable, instead
2417 of the backslashes before semicolons and special
2420 - Commandline Editing and History:
2421 CONFIG_CMDLINE_EDITING
2423 Enable editing and History functions for interactive
2424 commandline input operations
2426 - Default Environment:
2427 CONFIG_EXTRA_ENV_SETTINGS
2429 Define this to contain any number of null terminated
2430 strings (variable = value pairs) that will be part of
2431 the default environment compiled into the boot image.
2433 For example, place something like this in your
2434 board's config file:
2436 #define CONFIG_EXTRA_ENV_SETTINGS \
2440 Warning: This method is based on knowledge about the
2441 internal format how the environment is stored by the
2442 U-Boot code. This is NOT an official, exported
2443 interface! Although it is unlikely that this format
2444 will change soon, there is no guarantee either.
2445 You better know what you are doing here.
2447 Note: overly (ab)use of the default environment is
2448 discouraged. Make sure to check other ways to preset
2449 the environment like the "source" command or the
2452 CONFIG_ENV_VARS_UBOOT_CONFIG
2454 Define this in order to add variables describing the
2455 U-Boot build configuration to the default environment.
2456 These will be named arch, cpu, board, vendor, and soc.
2458 Enabling this option will cause the following to be defined:
2466 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2468 Define this in order to add variables describing certain
2469 run-time determined information about the hardware to the
2470 environment. These will be named board_name, board_rev.
2472 CONFIG_DELAY_ENVIRONMENT
2474 Normally the environment is loaded when the board is
2475 intialised so that it is available to U-Boot. This inhibits
2476 that so that the environment is not available until
2477 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2478 this is instead controlled by the value of
2479 /config/load-environment.
2481 - DataFlash Support:
2482 CONFIG_HAS_DATAFLASH
2484 Defining this option enables DataFlash features and
2485 allows to read/write in Dataflash via the standard
2488 - Serial Flash support
2491 Defining this option enables SPI flash commands
2492 'sf probe/read/write/erase/update'.
2494 Usage requires an initial 'probe' to define the serial
2495 flash parameters, followed by read/write/erase/update
2498 The following defaults may be provided by the platform
2499 to handle the common case when only a single serial
2500 flash is present on the system.
2502 CONFIG_SF_DEFAULT_BUS Bus identifier
2503 CONFIG_SF_DEFAULT_CS Chip-select
2504 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2505 CONFIG_SF_DEFAULT_SPEED in Hz
2509 Define this option to include a destructive SPI flash
2512 - SystemACE Support:
2515 Adding this option adds support for Xilinx SystemACE
2516 chips attached via some sort of local bus. The address
2517 of the chip must also be defined in the
2518 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2520 #define CONFIG_SYSTEMACE
2521 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2523 When SystemACE support is added, the "ace" device type
2524 becomes available to the fat commands, i.e. fatls.
2526 - TFTP Fixed UDP Port:
2529 If this is defined, the environment variable tftpsrcp
2530 is used to supply the TFTP UDP source port value.
2531 If tftpsrcp isn't defined, the normal pseudo-random port
2532 number generator is used.
2534 Also, the environment variable tftpdstp is used to supply
2535 the TFTP UDP destination port value. If tftpdstp isn't
2536 defined, the normal port 69 is used.
2538 The purpose for tftpsrcp is to allow a TFTP server to
2539 blindly start the TFTP transfer using the pre-configured
2540 target IP address and UDP port. This has the effect of
2541 "punching through" the (Windows XP) firewall, allowing
2542 the remainder of the TFTP transfer to proceed normally.
2543 A better solution is to properly configure the firewall,
2544 but sometimes that is not allowed.
2549 This enables a generic 'hash' command which can produce
2550 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2554 Enable the hash verify command (hash -v). This adds to code
2557 CONFIG_SHA1 - support SHA1 hashing
2558 CONFIG_SHA256 - support SHA256 hashing
2560 Note: There is also a sha1sum command, which should perhaps
2561 be deprecated in favour of 'hash sha1'.
2563 - Show boot progress:
2564 CONFIG_SHOW_BOOT_PROGRESS
2566 Defining this option allows to add some board-
2567 specific code (calling a user-provided function
2568 "show_boot_progress(int)") that enables you to show
2569 the system's boot progress on some display (for
2570 example, some LED's) on your board. At the moment,
2571 the following checkpoints are implemented:
2573 - Detailed boot stage timing
2575 Define this option to get detailed timing of each stage
2576 of the boot process.
2578 CONFIG_BOOTSTAGE_USER_COUNT
2579 This is the number of available user bootstage records.
2580 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2581 a new ID will be allocated from this stash. If you exceed
2582 the limit, recording will stop.
2584 CONFIG_BOOTSTAGE_REPORT
2585 Define this to print a report before boot, similar to this:
2587 Timer summary in microseconds:
2590 3,575,678 3,575,678 board_init_f start
2591 3,575,695 17 arch_cpu_init A9
2592 3,575,777 82 arch_cpu_init done
2593 3,659,598 83,821 board_init_r start
2594 3,910,375 250,777 main_loop
2595 29,916,167 26,005,792 bootm_start
2596 30,361,327 445,160 start_kernel
2598 CONFIG_CMD_BOOTSTAGE
2599 Add a 'bootstage' command which supports printing a report
2600 and un/stashing of bootstage data.
2602 CONFIG_BOOTSTAGE_FDT
2603 Stash the bootstage information in the FDT. A root 'bootstage'
2604 node is created with each bootstage id as a child. Each child
2605 has a 'name' property and either 'mark' containing the
2606 mark time in microsecond, or 'accum' containing the
2607 accumulated time for that bootstage id in microseconds.
2612 name = "board_init_f";
2621 Code in the Linux kernel can find this in /proc/devicetree.
2623 Legacy uImage format:
2626 1 common/cmd_bootm.c before attempting to boot an image
2627 -1 common/cmd_bootm.c Image header has bad magic number
2628 2 common/cmd_bootm.c Image header has correct magic number
2629 -2 common/cmd_bootm.c Image header has bad checksum
2630 3 common/cmd_bootm.c Image header has correct checksum
2631 -3 common/cmd_bootm.c Image data has bad checksum
2632 4 common/cmd_bootm.c Image data has correct checksum
2633 -4 common/cmd_bootm.c Image is for unsupported architecture
2634 5 common/cmd_bootm.c Architecture check OK
2635 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2636 6 common/cmd_bootm.c Image Type check OK
2637 -6 common/cmd_bootm.c gunzip uncompression error
2638 -7 common/cmd_bootm.c Unimplemented compression type
2639 7 common/cmd_bootm.c Uncompression OK
2640 8 common/cmd_bootm.c No uncompress/copy overwrite error
2641 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2643 9 common/image.c Start initial ramdisk verification
2644 -10 common/image.c Ramdisk header has bad magic number
2645 -11 common/image.c Ramdisk header has bad checksum
2646 10 common/image.c Ramdisk header is OK
2647 -12 common/image.c Ramdisk data has bad checksum
2648 11 common/image.c Ramdisk data has correct checksum
2649 12 common/image.c Ramdisk verification complete, start loading
2650 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2651 13 common/image.c Start multifile image verification
2652 14 common/image.c No initial ramdisk, no multifile, continue.
2654 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2656 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2657 -31 post/post.c POST test failed, detected by post_output_backlog()
2658 -32 post/post.c POST test failed, detected by post_run_single()
2660 34 common/cmd_doc.c before loading a Image from a DOC device
2661 -35 common/cmd_doc.c Bad usage of "doc" command
2662 35 common/cmd_doc.c correct usage of "doc" command
2663 -36 common/cmd_doc.c No boot device
2664 36 common/cmd_doc.c correct boot device
2665 -37 common/cmd_doc.c Unknown Chip ID on boot device
2666 37 common/cmd_doc.c correct chip ID found, device available
2667 -38 common/cmd_doc.c Read Error on boot device
2668 38 common/cmd_doc.c reading Image header from DOC device OK
2669 -39 common/cmd_doc.c Image header has bad magic number
2670 39 common/cmd_doc.c Image header has correct magic number
2671 -40 common/cmd_doc.c Error reading Image from DOC device
2672 40 common/cmd_doc.c Image header has correct magic number
2673 41 common/cmd_ide.c before loading a Image from a IDE device
2674 -42 common/cmd_ide.c Bad usage of "ide" command
2675 42 common/cmd_ide.c correct usage of "ide" command
2676 -43 common/cmd_ide.c No boot device
2677 43 common/cmd_ide.c boot device found
2678 -44 common/cmd_ide.c Device not available
2679 44 common/cmd_ide.c Device available
2680 -45 common/cmd_ide.c wrong partition selected
2681 45 common/cmd_ide.c partition selected
2682 -46 common/cmd_ide.c Unknown partition table
2683 46 common/cmd_ide.c valid partition table found
2684 -47 common/cmd_ide.c Invalid partition type
2685 47 common/cmd_ide.c correct partition type
2686 -48 common/cmd_ide.c Error reading Image Header on boot device
2687 48 common/cmd_ide.c reading Image Header from IDE device OK
2688 -49 common/cmd_ide.c Image header has bad magic number
2689 49 common/cmd_ide.c Image header has correct magic number
2690 -50 common/cmd_ide.c Image header has bad checksum
2691 50 common/cmd_ide.c Image header has correct checksum
2692 -51 common/cmd_ide.c Error reading Image from IDE device
2693 51 common/cmd_ide.c reading Image from IDE device OK
2694 52 common/cmd_nand.c before loading a Image from a NAND device
2695 -53 common/cmd_nand.c Bad usage of "nand" command
2696 53 common/cmd_nand.c correct usage of "nand" command
2697 -54 common/cmd_nand.c No boot device
2698 54 common/cmd_nand.c boot device found
2699 -55 common/cmd_nand.c Unknown Chip ID on boot device
2700 55 common/cmd_nand.c correct chip ID found, device available
2701 -56 common/cmd_nand.c Error reading Image Header on boot device
2702 56 common/cmd_nand.c reading Image Header from NAND device OK
2703 -57 common/cmd_nand.c Image header has bad magic number
2704 57 common/cmd_nand.c Image header has correct magic number
2705 -58 common/cmd_nand.c Error reading Image from NAND device
2706 58 common/cmd_nand.c reading Image from NAND device OK
2708 -60 common/env_common.c Environment has a bad CRC, using default
2710 64 net/eth.c starting with Ethernet configuration.
2711 -64 net/eth.c no Ethernet found.
2712 65 net/eth.c Ethernet found.
2714 -80 common/cmd_net.c usage wrong
2715 80 common/cmd_net.c before calling NetLoop()
2716 -81 common/cmd_net.c some error in NetLoop() occurred
2717 81 common/cmd_net.c NetLoop() back without error
2718 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2719 82 common/cmd_net.c trying automatic boot
2720 83 common/cmd_net.c running "source" command
2721 -83 common/cmd_net.c some error in automatic boot or "source" command
2722 84 common/cmd_net.c end without errors
2727 100 common/cmd_bootm.c Kernel FIT Image has correct format
2728 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2729 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2730 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2731 102 common/cmd_bootm.c Kernel unit name specified
2732 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2733 103 common/cmd_bootm.c Found configuration node
2734 104 common/cmd_bootm.c Got kernel subimage node offset
2735 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2736 105 common/cmd_bootm.c Kernel subimage hash verification OK
2737 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2738 106 common/cmd_bootm.c Architecture check OK
2739 -106 common/cmd_bootm.c Kernel subimage has wrong type
2740 107 common/cmd_bootm.c Kernel subimage type OK
2741 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2742 108 common/cmd_bootm.c Got kernel subimage data/size
2743 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2744 -109 common/cmd_bootm.c Can't get kernel subimage type
2745 -110 common/cmd_bootm.c Can't get kernel subimage comp
2746 -111 common/cmd_bootm.c Can't get kernel subimage os
2747 -112 common/cmd_bootm.c Can't get kernel subimage load address
2748 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2750 120 common/image.c Start initial ramdisk verification
2751 -120 common/image.c Ramdisk FIT image has incorrect format
2752 121 common/image.c Ramdisk FIT image has correct format
2753 122 common/image.c No ramdisk subimage unit name, using configuration
2754 -122 common/image.c Can't get configuration for ramdisk subimage
2755 123 common/image.c Ramdisk unit name specified
2756 -124 common/image.c Can't get ramdisk subimage node offset
2757 125 common/image.c Got ramdisk subimage node offset
2758 -125 common/image.c Ramdisk subimage hash verification failed
2759 126 common/image.c Ramdisk subimage hash verification OK
2760 -126 common/image.c Ramdisk subimage for unsupported architecture
2761 127 common/image.c Architecture check OK
2762 -127 common/image.c Can't get ramdisk subimage data/size
2763 128 common/image.c Got ramdisk subimage data/size
2764 129 common/image.c Can't get ramdisk load address
2765 -129 common/image.c Got ramdisk load address
2767 -130 common/cmd_doc.c Incorrect FIT image format
2768 131 common/cmd_doc.c FIT image format OK
2770 -140 common/cmd_ide.c Incorrect FIT image format
2771 141 common/cmd_ide.c FIT image format OK
2773 -150 common/cmd_nand.c Incorrect FIT image format
2774 151 common/cmd_nand.c FIT image format OK
2776 - FIT image support:
2778 Enable support for the FIT uImage format.
2780 CONFIG_FIT_BEST_MATCH
2781 When no configuration is explicitly selected, default to the
2782 one whose fdt's compatibility field best matches that of
2783 U-Boot itself. A match is considered "best" if it matches the
2784 most specific compatibility entry of U-Boot's fdt's root node.
2785 The order of entries in the configuration's fdt is ignored.
2787 - Standalone program support:
2788 CONFIG_STANDALONE_LOAD_ADDR
2790 This option defines a board specific value for the
2791 address where standalone program gets loaded, thus
2792 overwriting the architecture dependent default
2795 - Frame Buffer Address:
2798 Define CONFIG_FB_ADDR if you want to use specific
2799 address for frame buffer. This is typically the case
2800 when using a graphics controller has separate video
2801 memory. U-Boot will then place the frame buffer at
2802 the given address instead of dynamically reserving it
2803 in system RAM by calling lcd_setmem(), which grabs
2804 the memory for the frame buffer depending on the
2805 configured panel size.
2807 Please see board_init_f function.
2809 - Automatic software updates via TFTP server
2811 CONFIG_UPDATE_TFTP_CNT_MAX
2812 CONFIG_UPDATE_TFTP_MSEC_MAX
2814 These options enable and control the auto-update feature;
2815 for a more detailed description refer to doc/README.update.
2817 - MTD Support (mtdparts command, UBI support)
2820 Adds the MTD device infrastructure from the Linux kernel.
2821 Needed for mtdparts command support.
2823 CONFIG_MTD_PARTITIONS
2825 Adds the MTD partitioning infrastructure from the Linux
2826 kernel. Needed for UBI support.
2831 Adds commands for interacting with MTD partitions formatted
2832 with the UBI flash translation layer
2834 Requires also defining CONFIG_RBTREE
2836 CONFIG_UBI_SILENCE_MSG
2838 Make the verbose messages from UBI stop printing. This leaves
2839 warnings and errors enabled.
2844 Adds commands for interacting with UBI volumes formatted as
2845 UBIFS. UBIFS is read-only in u-boot.
2847 Requires UBI support as well as CONFIG_LZO
2849 CONFIG_UBIFS_SILENCE_MSG
2851 Make the verbose messages from UBIFS stop printing. This leaves
2852 warnings and errors enabled.
2856 Enable building of SPL globally.
2859 LDSCRIPT for linking the SPL binary.
2861 CONFIG_SPL_MAX_FOOTPRINT
2862 Maximum size in memory allocated to the SPL, BSS included.
2863 When defined, the linker checks that the actual memory
2864 used by SPL from _start to __bss_end does not exceed it.
2865 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2866 must not be both defined at the same time.
2869 Maximum size of the SPL image (text, data, rodata, and
2870 linker lists sections), BSS excluded.
2871 When defined, the linker checks that the actual size does
2874 CONFIG_SPL_TEXT_BASE
2875 TEXT_BASE for linking the SPL binary.
2877 CONFIG_SPL_RELOC_TEXT_BASE
2878 Address to relocate to. If unspecified, this is equal to
2879 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2881 CONFIG_SPL_BSS_START_ADDR
2882 Link address for the BSS within the SPL binary.
2884 CONFIG_SPL_BSS_MAX_SIZE
2885 Maximum size in memory allocated to the SPL BSS.
2886 When defined, the linker checks that the actual memory used
2887 by SPL from __bss_start to __bss_end does not exceed it.
2888 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2889 must not be both defined at the same time.
2892 Adress of the start of the stack SPL will use
2894 CONFIG_SPL_RELOC_STACK
2895 Adress of the start of the stack SPL will use after
2896 relocation. If unspecified, this is equal to
2899 CONFIG_SYS_SPL_MALLOC_START
2900 Starting address of the malloc pool used in SPL.
2902 CONFIG_SYS_SPL_MALLOC_SIZE
2903 The size of the malloc pool used in SPL.
2905 CONFIG_SPL_FRAMEWORK
2906 Enable the SPL framework under common/. This framework
2907 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2908 NAND loading of the Linux Kernel.
2910 CONFIG_SPL_DISPLAY_PRINT
2911 For ARM, enable an optional function to print more information
2912 about the running system.
2914 CONFIG_SPL_INIT_MINIMAL
2915 Arch init code should be built for a very small image
2917 CONFIG_SPL_LIBCOMMON_SUPPORT
2918 Support for common/libcommon.o in SPL binary
2920 CONFIG_SPL_LIBDISK_SUPPORT
2921 Support for disk/libdisk.o in SPL binary
2923 CONFIG_SPL_I2C_SUPPORT
2924 Support for drivers/i2c/libi2c.o in SPL binary
2926 CONFIG_SPL_GPIO_SUPPORT
2927 Support for drivers/gpio/libgpio.o in SPL binary
2929 CONFIG_SPL_MMC_SUPPORT
2930 Support for drivers/mmc/libmmc.o in SPL binary
2932 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2933 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2934 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2935 Address, size and partition on the MMC to load U-Boot from
2936 when the MMC is being used in raw mode.
2938 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2939 Sector to load kernel uImage from when MMC is being
2940 used in raw mode (for Falcon mode)
2942 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2943 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2944 Sector and number of sectors to load kernel argument
2945 parameters from when MMC is being used in raw mode
2948 CONFIG_SPL_FAT_SUPPORT
2949 Support for fs/fat/libfat.o in SPL binary
2951 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2952 Filename to read to load U-Boot when reading from FAT
2954 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
2955 Filename to read to load kernel uImage when reading
2956 from FAT (for Falcon mode)
2958 CONFIG_SPL_FAT_LOAD_ARGS_NAME
2959 Filename to read to load kernel argument parameters
2960 when reading from FAT (for Falcon mode)
2962 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2963 Set this for NAND SPL on PPC mpc83xx targets, so that
2964 start.S waits for the rest of the SPL to load before
2965 continuing (the hardware starts execution after just
2966 loading the first page rather than the full 4K).
2968 CONFIG_SPL_NAND_BASE
2969 Include nand_base.c in the SPL. Requires
2970 CONFIG_SPL_NAND_DRIVERS.
2972 CONFIG_SPL_NAND_DRIVERS
2973 SPL uses normal NAND drivers, not minimal drivers.
2976 Include standard software ECC in the SPL
2978 CONFIG_SPL_NAND_SIMPLE
2979 Support for NAND boot using simple NAND drivers that
2980 expose the cmd_ctrl() interface.
2982 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2983 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2984 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2985 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2986 CONFIG_SYS_NAND_ECCBYTES
2987 Defines the size and behavior of the NAND that SPL uses
2990 CONFIG_SYS_NAND_U_BOOT_OFFS
2991 Location in NAND to read U-Boot from
2993 CONFIG_SYS_NAND_U_BOOT_DST
2994 Location in memory to load U-Boot to
2996 CONFIG_SYS_NAND_U_BOOT_SIZE
2997 Size of image to load
2999 CONFIG_SYS_NAND_U_BOOT_START
3000 Entry point in loaded image to jump to
3002 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3003 Define this if you need to first read the OOB and then the
3004 data. This is used for example on davinci plattforms.
3006 CONFIG_SPL_OMAP3_ID_NAND
3007 Support for an OMAP3-specific set of functions to return the
3008 ID and MFR of the first attached NAND chip, if present.
3010 CONFIG_SPL_SERIAL_SUPPORT
3011 Support for drivers/serial/libserial.o in SPL binary
3013 CONFIG_SPL_SPI_FLASH_SUPPORT
3014 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3016 CONFIG_SPL_SPI_SUPPORT
3017 Support for drivers/spi/libspi.o in SPL binary
3019 CONFIG_SPL_RAM_DEVICE
3020 Support for running image already present in ram, in SPL binary
3022 CONFIG_SPL_LIBGENERIC_SUPPORT
3023 Support for lib/libgeneric.o in SPL binary
3026 Image offset to which the SPL should be padded before appending
3027 the SPL payload. By default, this is defined as
3028 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3029 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3030 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3033 Final target image containing SPL and payload. Some SPLs
3034 use an arch-specific makefile fragment instead, for
3035 example if more than one image needs to be produced.
3037 CONFIG_FIT_SPL_PRINT
3038 Printing information about a FIT image adds quite a bit of
3039 code to SPL. So this is normally disabled in SPL. Use this
3040 option to re-enable it. This will affect the output of the
3041 bootm command when booting a FIT image.
3046 [so far only for SMDK2400 boards]
3048 - Modem support enable:
3049 CONFIG_MODEM_SUPPORT
3051 - RTS/CTS Flow control enable:
3054 - Modem debug support:
3055 CONFIG_MODEM_SUPPORT_DEBUG
3057 Enables debugging stuff (char screen[1024], dbg())
3058 for modem support. Useful only with BDI2000.
3060 - Interrupt support (PPC):
3062 There are common interrupt_init() and timer_interrupt()
3063 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3064 for CPU specific initialization. interrupt_init_cpu()
3065 should set decrementer_count to appropriate value. If
3066 CPU resets decrementer automatically after interrupt
3067 (ppc4xx) it should set decrementer_count to zero.
3068 timer_interrupt() calls timer_interrupt_cpu() for CPU
3069 specific handling. If board has watchdog / status_led
3070 / other_activity_monitor it works automatically from
3071 general timer_interrupt().
3075 In the target system modem support is enabled when a
3076 specific key (key combination) is pressed during
3077 power-on. Otherwise U-Boot will boot normally
3078 (autoboot). The key_pressed() function is called from
3079 board_init(). Currently key_pressed() is a dummy
3080 function, returning 1 and thus enabling modem
3083 If there are no modem init strings in the
3084 environment, U-Boot proceed to autoboot; the
3085 previous output (banner, info printfs) will be
3088 See also: doc/README.Modem
3090 Board initialization settings:
3091 ------------------------------
3093 During Initialization u-boot calls a number of board specific functions
3094 to allow the preparation of board specific prerequisites, e.g. pin setup
3095 before drivers are initialized. To enable these callbacks the
3096 following configuration macros have to be defined. Currently this is
3097 architecture specific, so please check arch/your_architecture/lib/board.c
3098 typically in board_init_f() and board_init_r().
3100 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3101 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3102 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3103 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3105 Configuration Settings:
3106 -----------------------
3108 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3109 undefine this when you're short of memory.
3111 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3112 width of the commands listed in the 'help' command output.
3114 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3115 prompt for user input.
3117 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3119 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3121 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3123 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3124 the application (usually a Linux kernel) when it is
3127 - CONFIG_SYS_BAUDRATE_TABLE:
3128 List of legal baudrate settings for this board.
3130 - CONFIG_SYS_CONSOLE_INFO_QUIET
3131 Suppress display of console information at boot.
3133 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3134 If the board specific function
3135 extern int overwrite_console (void);
3136 returns 1, the stdin, stderr and stdout are switched to the
3137 serial port, else the settings in the environment are used.
3139 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3140 Enable the call to overwrite_console().
3142 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3143 Enable overwrite of previous console environment settings.
3145 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3146 Begin and End addresses of the area used by the
3149 - CONFIG_SYS_ALT_MEMTEST:
3150 Enable an alternate, more extensive memory test.
3152 - CONFIG_SYS_MEMTEST_SCRATCH:
3153 Scratch address used by the alternate memory test
3154 You only need to set this if address zero isn't writeable
3156 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3157 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3158 this specified memory area will get subtracted from the top
3159 (end) of RAM and won't get "touched" at all by U-Boot. By
3160 fixing up gd->ram_size the Linux kernel should gets passed
3161 the now "corrected" memory size and won't touch it either.
3162 This should work for arch/ppc and arch/powerpc. Only Linux
3163 board ports in arch/powerpc with bootwrapper support that
3164 recalculate the memory size from the SDRAM controller setup
3165 will have to get fixed in Linux additionally.
3167 This option can be used as a workaround for the 440EPx/GRx
3168 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3171 WARNING: Please make sure that this value is a multiple of
3172 the Linux page size (normally 4k). If this is not the case,
3173 then the end address of the Linux memory will be located at a
3174 non page size aligned address and this could cause major
3177 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3178 Enable temporary baudrate change while serial download
3180 - CONFIG_SYS_SDRAM_BASE:
3181 Physical start address of SDRAM. _Must_ be 0 here.
3183 - CONFIG_SYS_MBIO_BASE:
3184 Physical start address of Motherboard I/O (if using a
3187 - CONFIG_SYS_FLASH_BASE:
3188 Physical start address of Flash memory.
3190 - CONFIG_SYS_MONITOR_BASE:
3191 Physical start address of boot monitor code (set by
3192 make config files to be same as the text base address
3193 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3194 CONFIG_SYS_FLASH_BASE when booting from flash.
3196 - CONFIG_SYS_MONITOR_LEN:
3197 Size of memory reserved for monitor code, used to
3198 determine _at_compile_time_ (!) if the environment is
3199 embedded within the U-Boot image, or in a separate
3202 - CONFIG_SYS_MALLOC_LEN:
3203 Size of DRAM reserved for malloc() use.
3205 - CONFIG_SYS_BOOTM_LEN:
3206 Normally compressed uImages are limited to an
3207 uncompressed size of 8 MBytes. If this is not enough,
3208 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3209 to adjust this setting to your needs.
3211 - CONFIG_SYS_BOOTMAPSZ:
3212 Maximum size of memory mapped by the startup code of
3213 the Linux kernel; all data that must be processed by
3214 the Linux kernel (bd_info, boot arguments, FDT blob if
3215 used) must be put below this limit, unless "bootm_low"
3216 enviroment variable is defined and non-zero. In such case
3217 all data for the Linux kernel must be between "bootm_low"
3218 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3219 variable "bootm_mapsize" will override the value of
3220 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3221 then the value in "bootm_size" will be used instead.
3223 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3224 Enable initrd_high functionality. If defined then the
3225 initrd_high feature is enabled and the bootm ramdisk subcommand
3228 - CONFIG_SYS_BOOT_GET_CMDLINE:
3229 Enables allocating and saving kernel cmdline in space between
3230 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3232 - CONFIG_SYS_BOOT_GET_KBD:
3233 Enables allocating and saving a kernel copy of the bd_info in
3234 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3236 - CONFIG_SYS_MAX_FLASH_BANKS:
3237 Max number of Flash memory banks
3239 - CONFIG_SYS_MAX_FLASH_SECT:
3240 Max number of sectors on a Flash chip
3242 - CONFIG_SYS_FLASH_ERASE_TOUT:
3243 Timeout for Flash erase operations (in ms)
3245 - CONFIG_SYS_FLASH_WRITE_TOUT:
3246 Timeout for Flash write operations (in ms)
3248 - CONFIG_SYS_FLASH_LOCK_TOUT
3249 Timeout for Flash set sector lock bit operation (in ms)
3251 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3252 Timeout for Flash clear lock bits operation (in ms)
3254 - CONFIG_SYS_FLASH_PROTECTION
3255 If defined, hardware flash sectors protection is used
3256 instead of U-Boot software protection.
3258 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3260 Enable TFTP transfers directly to flash memory;
3261 without this option such a download has to be
3262 performed in two steps: (1) download to RAM, and (2)
3263 copy from RAM to flash.
3265 The two-step approach is usually more reliable, since
3266 you can check if the download worked before you erase
3267 the flash, but in some situations (when system RAM is
3268 too limited to allow for a temporary copy of the
3269 downloaded image) this option may be very useful.
3271 - CONFIG_SYS_FLASH_CFI:
3272 Define if the flash driver uses extra elements in the
3273 common flash structure for storing flash geometry.
3275 - CONFIG_FLASH_CFI_DRIVER
3276 This option also enables the building of the cfi_flash driver
3277 in the drivers directory
3279 - CONFIG_FLASH_CFI_MTD
3280 This option enables the building of the cfi_mtd driver
3281 in the drivers directory. The driver exports CFI flash
3284 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3285 Use buffered writes to flash.
3287 - CONFIG_FLASH_SPANSION_S29WS_N
3288 s29ws-n MirrorBit flash has non-standard addresses for buffered
3291 - CONFIG_SYS_FLASH_QUIET_TEST
3292 If this option is defined, the common CFI flash doesn't
3293 print it's warning upon not recognized FLASH banks. This
3294 is useful, if some of the configured banks are only
3295 optionally available.
3297 - CONFIG_FLASH_SHOW_PROGRESS
3298 If defined (must be an integer), print out countdown
3299 digits and dots. Recommended value: 45 (9..1) for 80
3300 column displays, 15 (3..1) for 40 column displays.
3302 - CONFIG_FLASH_VERIFY
3303 If defined, the content of the flash (destination) is compared
3304 against the source after the write operation. An error message
3305 will be printed when the contents are not identical.
3306 Please note that this option is useless in nearly all cases,
3307 since such flash programming errors usually are detected earlier
3308 while unprotecting/erasing/programming. Please only enable
3309 this option if you really know what you are doing.
3311 - CONFIG_SYS_RX_ETH_BUFFER:
3312 Defines the number of Ethernet receive buffers. On some
3313 Ethernet controllers it is recommended to set this value
3314 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3315 buffers can be full shortly after enabling the interface
3316 on high Ethernet traffic.
3317 Defaults to 4 if not defined.
3319 - CONFIG_ENV_MAX_ENTRIES
3321 Maximum number of entries in the hash table that is used
3322 internally to store the environment settings. The default
3323 setting is supposed to be generous and should work in most
3324 cases. This setting can be used to tune behaviour; see
3325 lib/hashtable.c for details.
3327 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3328 - CONFIG_ENV_FLAGS_LIST_STATIC
3329 Enable validation of the values given to enviroment variables when
3330 calling env set. Variables can be restricted to only decimal,
3331 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3332 the variables can also be restricted to IP address or MAC address.
3334 The format of the list is:
3335 type_attribute = [s|d|x|b|i|m]
3336 access_atribute = [a|r|o|c]
3337 attributes = type_attribute[access_atribute]
3338 entry = variable_name[:attributes]
3341 The type attributes are:
3342 s - String (default)
3345 b - Boolean ([1yYtT|0nNfF])
3349 The access attributes are:
3355 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3356 Define this to a list (string) to define the ".flags"
3357 envirnoment variable in the default or embedded environment.
3359 - CONFIG_ENV_FLAGS_LIST_STATIC
3360 Define this to a list (string) to define validation that
3361 should be done if an entry is not found in the ".flags"
3362 environment variable. To override a setting in the static
3363 list, simply add an entry for the same variable name to the
3366 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3367 If defined, don't allow the -f switch to env set override variable
3370 - CONFIG_SYS_GENERIC_BOARD
3371 This selects the architecture-generic board system instead of the
3372 architecture-specific board files. It is intended to move boards
3373 to this new framework over time. Defining this will disable the
3374 arch/foo/lib/board.c file and use common/board_f.c and
3375 common/board_r.c instead. To use this option your architecture
3376 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3377 its config.mk file). If you find problems enabling this option on
3378 your board please report the problem and send patches!
3380 - CONFIG_SYS_SYM_OFFSETS
3381 This is set by architectures that use offsets for link symbols
3382 instead of absolute values. So bss_start is obtained using an
3383 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3384 directly. You should not need to touch this setting.
3386 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3387 This is set by OMAP boards for the max time that reset should
3388 be asserted. See doc/README.omap-reset-time for details on how
3389 the value can be calulated on a given board.
3391 The following definitions that deal with the placement and management
3392 of environment data (variable area); in general, we support the
3393 following configurations:
3395 - CONFIG_BUILD_ENVCRC:
3397 Builds up envcrc with the target environment so that external utils
3398 may easily extract it and embed it in final U-Boot images.
3400 - CONFIG_ENV_IS_IN_FLASH:
3402 Define this if the environment is in flash memory.
3404 a) The environment occupies one whole flash sector, which is
3405 "embedded" in the text segment with the U-Boot code. This
3406 happens usually with "bottom boot sector" or "top boot
3407 sector" type flash chips, which have several smaller
3408 sectors at the start or the end. For instance, such a
3409 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3410 such a case you would place the environment in one of the
3411 4 kB sectors - with U-Boot code before and after it. With
3412 "top boot sector" type flash chips, you would put the
3413 environment in one of the last sectors, leaving a gap
3414 between U-Boot and the environment.
3416 - CONFIG_ENV_OFFSET:
3418 Offset of environment data (variable area) to the
3419 beginning of flash memory; for instance, with bottom boot
3420 type flash chips the second sector can be used: the offset
3421 for this sector is given here.
3423 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3427 This is just another way to specify the start address of
3428 the flash sector containing the environment (instead of
3431 - CONFIG_ENV_SECT_SIZE:
3433 Size of the sector containing the environment.
3436 b) Sometimes flash chips have few, equal sized, BIG sectors.
3437 In such a case you don't want to spend a whole sector for
3442 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3443 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3444 of this flash sector for the environment. This saves
3445 memory for the RAM copy of the environment.
3447 It may also save flash memory if you decide to use this
3448 when your environment is "embedded" within U-Boot code,
3449 since then the remainder of the flash sector could be used
3450 for U-Boot code. It should be pointed out that this is
3451 STRONGLY DISCOURAGED from a robustness point of view:
3452 updating the environment in flash makes it always
3453 necessary to erase the WHOLE sector. If something goes
3454 wrong before the contents has been restored from a copy in
3455 RAM, your target system will be dead.
3457 - CONFIG_ENV_ADDR_REDUND
3458 CONFIG_ENV_SIZE_REDUND
3460 These settings describe a second storage area used to hold
3461 a redundant copy of the environment data, so that there is
3462 a valid backup copy in case there is a power failure during
3463 a "saveenv" operation.
3465 BE CAREFUL! Any changes to the flash layout, and some changes to the
3466 source code will make it necessary to adapt <board>/u-boot.lds*
3470 - CONFIG_ENV_IS_IN_NVRAM:
3472 Define this if you have some non-volatile memory device
3473 (NVRAM, battery buffered SRAM) which you want to use for the
3479 These two #defines are used to determine the memory area you
3480 want to use for environment. It is assumed that this memory
3481 can just be read and written to, without any special
3484 BE CAREFUL! The first access to the environment happens quite early
3485 in U-Boot initalization (when we try to get the setting of for the
3486 console baudrate). You *MUST* have mapped your NVRAM area then, or
3489 Please note that even with NVRAM we still use a copy of the
3490 environment in RAM: we could work on NVRAM directly, but we want to
3491 keep settings there always unmodified except somebody uses "saveenv"
3492 to save the current settings.
3495 - CONFIG_ENV_IS_IN_EEPROM:
3497 Use this if you have an EEPROM or similar serial access
3498 device and a driver for it.
3500 - CONFIG_ENV_OFFSET:
3503 These two #defines specify the offset and size of the
3504 environment area within the total memory of your EEPROM.
3506 - CONFIG_SYS_I2C_EEPROM_ADDR:
3507 If defined, specified the chip address of the EEPROM device.
3508 The default address is zero.
3510 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3511 If defined, the number of bits used to address bytes in a
3512 single page in the EEPROM device. A 64 byte page, for example
3513 would require six bits.
3515 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3516 If defined, the number of milliseconds to delay between
3517 page writes. The default is zero milliseconds.
3519 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3520 The length in bytes of the EEPROM memory array address. Note
3521 that this is NOT the chip address length!
3523 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3524 EEPROM chips that implement "address overflow" are ones
3525 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3526 address and the extra bits end up in the "chip address" bit
3527 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3530 Note that we consider the length of the address field to
3531 still be one byte because the extra address bits are hidden
3532 in the chip address.
3534 - CONFIG_SYS_EEPROM_SIZE:
3535 The size in bytes of the EEPROM device.
3537 - CONFIG_ENV_EEPROM_IS_ON_I2C
3538 define this, if you have I2C and SPI activated, and your
3539 EEPROM, which holds the environment, is on the I2C bus.
3541 - CONFIG_I2C_ENV_EEPROM_BUS
3542 if you have an Environment on an EEPROM reached over
3543 I2C muxes, you can define here, how to reach this
3544 EEPROM. For example:
3546 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3548 EEPROM which holds the environment, is reached over
3549 a pca9547 i2c mux with address 0x70, channel 3.
3551 - CONFIG_ENV_IS_IN_DATAFLASH:
3553 Define this if you have a DataFlash memory device which you
3554 want to use for the environment.
3556 - CONFIG_ENV_OFFSET:
3560 These three #defines specify the offset and size of the
3561 environment area within the total memory of your DataFlash placed
3562 at the specified address.
3564 - CONFIG_ENV_IS_IN_REMOTE:
3566 Define this if you have a remote memory space which you
3567 want to use for the local device's environment.
3572 These two #defines specify the address and size of the
3573 environment area within the remote memory space. The
3574 local device can get the environment from remote memory
3575 space by SRIO or PCIE links.
3577 BE CAREFUL! For some special cases, the local device can not use
3578 "saveenv" command. For example, the local device will get the
3579 environment stored in a remote NOR flash by SRIO or PCIE link,
3580 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3582 - CONFIG_ENV_IS_IN_NAND:
3584 Define this if you have a NAND device which you want to use
3585 for the environment.
3587 - CONFIG_ENV_OFFSET:
3590 These two #defines specify the offset and size of the environment
3591 area within the first NAND device. CONFIG_ENV_OFFSET must be
3592 aligned to an erase block boundary.
3594 - CONFIG_ENV_OFFSET_REDUND (optional):
3596 This setting describes a second storage area of CONFIG_ENV_SIZE
3597 size used to hold a redundant copy of the environment data, so
3598 that there is a valid backup copy in case there is a power failure
3599 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3600 aligned to an erase block boundary.
3602 - CONFIG_ENV_RANGE (optional):
3604 Specifies the length of the region in which the environment
3605 can be written. This should be a multiple of the NAND device's
3606 block size. Specifying a range with more erase blocks than
3607 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3608 the range to be avoided.
3610 - CONFIG_ENV_OFFSET_OOB (optional):
3612 Enables support for dynamically retrieving the offset of the
3613 environment from block zero's out-of-band data. The
3614 "nand env.oob" command can be used to record this offset.
3615 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3616 using CONFIG_ENV_OFFSET_OOB.
3618 - CONFIG_NAND_ENV_DST
3620 Defines address in RAM to which the nand_spl code should copy the
3621 environment. If redundant environment is used, it will be copied to
3622 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3624 - CONFIG_ENV_IS_IN_UBI:
3626 Define this if you have an UBI volume that you want to use for the
3627 environment. This has the benefit of wear-leveling the environment
3628 accesses, which is important on NAND.
3630 - CONFIG_ENV_UBI_PART:
3632 Define this to a string that is the mtd partition containing the UBI.
3634 - CONFIG_ENV_UBI_VOLUME:
3636 Define this to the name of the volume that you want to store the
3639 - CONFIG_ENV_UBI_VOLUME_REDUND:
3641 Define this to the name of another volume to store a second copy of
3642 the environment in. This will enable redundant environments in UBI.
3643 It is assumed that both volumes are in the same MTD partition.
3645 - CONFIG_UBI_SILENCE_MSG
3646 - CONFIG_UBIFS_SILENCE_MSG
3648 You will probably want to define these to avoid a really noisy system
3649 when storing the env in UBI.
3651 - CONFIG_ENV_IS_IN_MMC:
3653 Define this if you have an MMC device which you want to use for the
3656 - CONFIG_SYS_MMC_ENV_DEV:
3658 Specifies which MMC device the environment is stored in.
3660 - CONFIG_SYS_MMC_ENV_PART (optional):
3662 Specifies which MMC partition the environment is stored in. If not
3663 set, defaults to partition 0, the user area. Common values might be
3664 1 (first MMC boot partition), 2 (second MMC boot partition).
3666 - CONFIG_ENV_OFFSET:
3669 These two #defines specify the offset and size of the environment
3670 area within the specified MMC device.
3672 If offset is positive (the usual case), it is treated as relative to
3673 the start of the MMC partition. If offset is negative, it is treated
3674 as relative to the end of the MMC partition. This can be useful if
3675 your board may be fitted with different MMC devices, which have
3676 different sizes for the MMC partitions, and you always want the
3677 environment placed at the very end of the partition, to leave the
3678 maximum possible space before it, to store other data.
3680 These two values are in units of bytes, but must be aligned to an
3681 MMC sector boundary.
3683 - CONFIG_ENV_OFFSET_REDUND (optional):
3685 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3686 hold a redundant copy of the environment data. This provides a
3687 valid backup copy in case the other copy is corrupted, e.g. due
3688 to a power failure during a "saveenv" operation.
3690 This value may also be positive or negative; this is handled in the
3691 same way as CONFIG_ENV_OFFSET.
3693 This value is also in units of bytes, but must also be aligned to
3694 an MMC sector boundary.
3696 - CONFIG_ENV_SIZE_REDUND (optional):
3698 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3699 set. If this value is set, it must be set to the same value as
3702 - CONFIG_SYS_SPI_INIT_OFFSET
3704 Defines offset to the initial SPI buffer area in DPRAM. The
3705 area is used at an early stage (ROM part) if the environment
3706 is configured to reside in the SPI EEPROM: We need a 520 byte
3707 scratch DPRAM area. It is used between the two initialization
3708 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3709 to be a good choice since it makes it far enough from the
3710 start of the data area as well as from the stack pointer.
3712 Please note that the environment is read-only until the monitor
3713 has been relocated to RAM and a RAM copy of the environment has been
3714 created; also, when using EEPROM you will have to use getenv_f()
3715 until then to read environment variables.
3717 The environment is protected by a CRC32 checksum. Before the monitor
3718 is relocated into RAM, as a result of a bad CRC you will be working
3719 with the compiled-in default environment - *silently*!!! [This is
3720 necessary, because the first environment variable we need is the
3721 "baudrate" setting for the console - if we have a bad CRC, we don't
3722 have any device yet where we could complain.]
3724 Note: once the monitor has been relocated, then it will complain if
3725 the default environment is used; a new CRC is computed as soon as you
3726 use the "saveenv" command to store a valid environment.
3728 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3729 Echo the inverted Ethernet link state to the fault LED.
3731 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3732 also needs to be defined.
3734 - CONFIG_SYS_FAULT_MII_ADDR:
3735 MII address of the PHY to check for the Ethernet link state.
3737 - CONFIG_NS16550_MIN_FUNCTIONS:
3738 Define this if you desire to only have use of the NS16550_init
3739 and NS16550_putc functions for the serial driver located at
3740 drivers/serial/ns16550.c. This option is useful for saving
3741 space for already greatly restricted images, including but not
3742 limited to NAND_SPL configurations.
3744 - CONFIG_DISPLAY_BOARDINFO
3745 Display information about the board that U-Boot is running on
3746 when U-Boot starts up. The board function checkboard() is called
3749 - CONFIG_DISPLAY_BOARDINFO_LATE
3750 Similar to the previous option, but display this information
3751 later, once stdio is running and output goes to the LCD, if
3754 Low Level (hardware related) configuration options:
3755 ---------------------------------------------------
3757 - CONFIG_SYS_CACHELINE_SIZE:
3758 Cache Line Size of the CPU.
3760 - CONFIG_SYS_DEFAULT_IMMR:
3761 Default address of the IMMR after system reset.
3763 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3764 and RPXsuper) to be able to adjust the position of
3765 the IMMR register after a reset.
3767 - CONFIG_SYS_CCSRBAR_DEFAULT:
3768 Default (power-on reset) physical address of CCSR on Freescale
3771 - CONFIG_SYS_CCSRBAR:
3772 Virtual address of CCSR. On a 32-bit build, this is typically
3773 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3775 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3776 for cross-platform code that uses that macro instead.
3778 - CONFIG_SYS_CCSRBAR_PHYS:
3779 Physical address of CCSR. CCSR can be relocated to a new
3780 physical address, if desired. In this case, this macro should
3781 be set to that address. Otherwise, it should be set to the
3782 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3783 is typically relocated on 36-bit builds. It is recommended
3784 that this macro be defined via the _HIGH and _LOW macros:
3786 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3787 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3789 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3790 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3791 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3792 used in assembly code, so it must not contain typecasts or
3793 integer size suffixes (e.g. "ULL").
3795 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3796 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3797 used in assembly code, so it must not contain typecasts or
3798 integer size suffixes (e.g. "ULL").
3800 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3801 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3802 forced to a value that ensures that CCSR is not relocated.
3804 - Floppy Disk Support:
3805 CONFIG_SYS_FDC_DRIVE_NUMBER
3807 the default drive number (default value 0)
3809 CONFIG_SYS_ISA_IO_STRIDE
3811 defines the spacing between FDC chipset registers
3814 CONFIG_SYS_ISA_IO_OFFSET
3816 defines the offset of register from address. It
3817 depends on which part of the data bus is connected to
3818 the FDC chipset. (default value 0)
3820 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3821 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3824 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3825 fdc_hw_init() is called at the beginning of the FDC
3826 setup. fdc_hw_init() must be provided by the board
3827 source code. It is used to make hardware dependant
3831 Most IDE controllers were designed to be connected with PCI
3832 interface. Only few of them were designed for AHB interface.
3833 When software is doing ATA command and data transfer to
3834 IDE devices through IDE-AHB controller, some additional
3835 registers accessing to these kind of IDE-AHB controller
3838 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3839 DO NOT CHANGE unless you know exactly what you're
3840 doing! (11-4) [MPC8xx/82xx systems only]
3842 - CONFIG_SYS_INIT_RAM_ADDR:
3844 Start address of memory area that can be used for
3845 initial data and stack; please note that this must be
3846 writable memory that is working WITHOUT special
3847 initialization, i. e. you CANNOT use normal RAM which
3848 will become available only after programming the
3849 memory controller and running certain initialization
3852 U-Boot uses the following memory types:
3853 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3854 - MPC824X: data cache
3855 - PPC4xx: data cache
3857 - CONFIG_SYS_GBL_DATA_OFFSET:
3859 Offset of the initial data structure in the memory
3860 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3861 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3862 data is located at the end of the available space
3863 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3864 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3865 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3866 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3869 On the MPC824X (or other systems that use the data
3870 cache for initial memory) the address chosen for
3871 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3872 point to an otherwise UNUSED address space between
3873 the top of RAM and the start of the PCI space.
3875 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3877 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3879 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3881 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3883 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3885 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3887 - CONFIG_SYS_OR_TIMING_SDRAM:
3890 - CONFIG_SYS_MAMR_PTA:
3891 periodic timer for refresh
3893 - CONFIG_SYS_DER: Debug Event Register (37-47)
3895 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3896 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3897 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3898 CONFIG_SYS_BR1_PRELIM:
3899 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3901 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3902 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3903 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3904 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3906 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3907 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3908 Machine Mode Register and Memory Periodic Timer
3909 Prescaler definitions (SDRAM timing)
3911 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3912 enable I2C microcode relocation patch (MPC8xx);
3913 define relocation offset in DPRAM [DSP2]
3915 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3916 enable SMC microcode relocation patch (MPC8xx);
3917 define relocation offset in DPRAM [SMC1]
3919 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3920 enable SPI microcode relocation patch (MPC8xx);
3921 define relocation offset in DPRAM [SCC4]
3923 - CONFIG_SYS_USE_OSCCLK:
3924 Use OSCM clock mode on MBX8xx board. Be careful,
3925 wrong setting might damage your board. Read
3926 doc/README.MBX before setting this variable!
3928 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3929 Offset of the bootmode word in DPRAM used by post
3930 (Power On Self Tests). This definition overrides
3931 #define'd default value in commproc.h resp.
3934 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3935 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3936 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3937 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3938 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3939 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3940 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3941 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3942 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3944 - CONFIG_PCI_DISABLE_PCIE:
3945 Disable PCI-Express on systems where it is supported but not
3948 - CONFIG_PCI_ENUM_ONLY
3949 Only scan through and get the devices on the busses.
3950 Don't do any setup work, presumably because someone or
3951 something has already done it, and we don't need to do it
3952 a second time. Useful for platforms that are pre-booted
3953 by coreboot or similar.
3955 - CONFIG_PCI_INDIRECT_BRIDGE:
3956 Enable support for indirect PCI bridges.
3959 Chip has SRIO or not
3962 Board has SRIO 1 port available
3965 Board has SRIO 2 port available
3967 - CONFIG_SYS_SRIOn_MEM_VIRT:
3968 Virtual Address of SRIO port 'n' memory region
3970 - CONFIG_SYS_SRIOn_MEM_PHYS:
3971 Physical Address of SRIO port 'n' memory region
3973 - CONFIG_SYS_SRIOn_MEM_SIZE:
3974 Size of SRIO port 'n' memory region
3976 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3977 Defined to tell the NAND controller that the NAND chip is using
3979 Not all NAND drivers use this symbol.
3980 Example of drivers that use it:
3981 - drivers/mtd/nand/ndfc.c
3982 - drivers/mtd/nand/mxc_nand.c
3984 - CONFIG_SYS_NDFC_EBC0_CFG
3985 Sets the EBC0_CFG register for the NDFC. If not defined
3986 a default value will be used.
3989 Get DDR timing information from an I2C EEPROM. Common
3990 with pluggable memory modules such as SODIMMs
3993 I2C address of the SPD EEPROM
3995 - CONFIG_SYS_SPD_BUS_NUM
3996 If SPD EEPROM is on an I2C bus other than the first
3997 one, specify here. Note that the value must resolve
3998 to something your driver can deal with.
4000 - CONFIG_SYS_DDR_RAW_TIMING
4001 Get DDR timing information from other than SPD. Common with
4002 soldered DDR chips onboard without SPD. DDR raw timing
4003 parameters are extracted from datasheet and hard-coded into
4004 header files or board specific files.
4006 - CONFIG_FSL_DDR_INTERACTIVE
4007 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4009 - CONFIG_SYS_83XX_DDR_USES_CS0
4010 Only for 83xx systems. If specified, then DDR should
4011 be configured using CS0 and CS1 instead of CS2 and CS3.
4013 - CONFIG_ETHER_ON_FEC[12]
4014 Define to enable FEC[12] on a 8xx series processor.
4016 - CONFIG_FEC[12]_PHY
4017 Define to the hardcoded PHY address which corresponds
4018 to the given FEC; i. e.
4019 #define CONFIG_FEC1_PHY 4
4020 means that the PHY with address 4 is connected to FEC1
4022 When set to -1, means to probe for first available.
4024 - CONFIG_FEC[12]_PHY_NORXERR
4025 The PHY does not have a RXERR line (RMII only).
4026 (so program the FEC to ignore it).
4029 Enable RMII mode for all FECs.
4030 Note that this is a global option, we can't
4031 have one FEC in standard MII mode and another in RMII mode.
4033 - CONFIG_CRC32_VERIFY
4034 Add a verify option to the crc32 command.
4037 => crc32 -v <address> <count> <crc32>
4039 Where address/count indicate a memory area
4040 and crc32 is the correct crc32 which the
4044 Add the "loopw" memory command. This only takes effect if
4045 the memory commands are activated globally (CONFIG_CMD_MEM).
4048 Add the "mdc" and "mwc" memory commands. These are cyclic
4053 This command will print 4 bytes (10,11,12,13) each 500 ms.
4055 => mwc.l 100 12345678 10
4056 This command will write 12345678 to address 100 all 10 ms.
4058 This only takes effect if the memory commands are activated
4059 globally (CONFIG_CMD_MEM).
4061 - CONFIG_SKIP_LOWLEVEL_INIT
4062 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4063 low level initializations (like setting up the memory
4064 controller) are omitted and/or U-Boot does not
4065 relocate itself into RAM.
4067 Normally this variable MUST NOT be defined. The only
4068 exception is when U-Boot is loaded (to RAM) by some
4069 other boot loader or by a debugger which performs
4070 these initializations itself.
4073 Modifies the behaviour of start.S when compiling a loader
4074 that is executed before the actual U-Boot. E.g. when
4075 compiling a NAND SPL.
4077 - CONFIG_ARCH_MAP_SYSMEM
4078 Generally U-Boot (and in particular the md command) uses
4079 effective address. It is therefore not necessary to regard
4080 U-Boot address as virtual addresses that need to be translated
4081 to physical addresses. However, sandbox requires this, since
4082 it maintains its own little RAM buffer which contains all
4083 addressable memory. This option causes some memory accesses
4084 to be mapped through map_sysmem() / unmap_sysmem().
4086 - CONFIG_USE_ARCH_MEMCPY
4087 CONFIG_USE_ARCH_MEMSET
4088 If these options are used a optimized version of memcpy/memset will
4089 be used if available. These functions may be faster under some
4090 conditions but may increase the binary size.
4092 - CONFIG_X86_RESET_VECTOR
4093 If defined, the x86 reset vector code is included. This is not
4094 needed when U-Boot is running from Coreboot.
4097 Defines the MPU clock speed (in MHz).
4099 NOTE : currently only supported on AM335x platforms.
4101 Freescale QE/FMAN Firmware Support:
4102 -----------------------------------
4104 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4105 loading of "firmware", which is encoded in the QE firmware binary format.
4106 This firmware often needs to be loaded during U-Boot booting, so macros
4107 are used to identify the storage device (NOR flash, SPI, etc) and the address
4110 - CONFIG_SYS_QE_FMAN_FW_ADDR
4111 The address in the storage device where the firmware is located. The
4112 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4115 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4116 The maximum possible size of the firmware. The firmware binary format
4117 has a field that specifies the actual size of the firmware, but it
4118 might not be possible to read any part of the firmware unless some
4119 local storage is allocated to hold the entire firmware first.
4121 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4122 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4123 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4124 virtual address in NOR flash.
4126 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4127 Specifies that QE/FMAN firmware is located in NAND flash.
4128 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4130 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4131 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4132 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4134 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4135 Specifies that QE/FMAN firmware is located on the primary SPI
4136 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4138 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4139 Specifies that QE/FMAN firmware is located in the remote (master)
4140 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4141 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4142 window->master inbound window->master LAW->the ucode address in
4143 master's memory space.
4145 Building the Software:
4146 ======================
4148 Building U-Boot has been tested in several native build environments
4149 and in many different cross environments. Of course we cannot support
4150 all possibly existing versions of cross development tools in all
4151 (potentially obsolete) versions. In case of tool chain problems we
4152 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4153 which is extensively used to build and test U-Boot.
4155 If you are not using a native environment, it is assumed that you
4156 have GNU cross compiling tools available in your path. In this case,
4157 you must set the environment variable CROSS_COMPILE in your shell.
4158 Note that no changes to the Makefile or any other source files are
4159 necessary. For example using the ELDK on a 4xx CPU, please enter:
4161 $ CROSS_COMPILE=ppc_4xx-
4162 $ export CROSS_COMPILE
4164 Note: If you wish to generate Windows versions of the utilities in
4165 the tools directory you can use the MinGW toolchain
4166 (http://www.mingw.org). Set your HOST tools to the MinGW
4167 toolchain and execute 'make tools'. For example:
4169 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4171 Binaries such as tools/mkimage.exe will be created which can
4172 be executed on computers running Windows.
4174 U-Boot is intended to be simple to build. After installing the
4175 sources you must configure U-Boot for one specific board type. This
4180 where "NAME_config" is the name of one of the existing configu-
4181 rations; see boards.cfg for supported names.
4183 Note: for some board special configuration names may exist; check if
4184 additional information is available from the board vendor; for
4185 instance, the TQM823L systems are available without (standard)
4186 or with LCD support. You can select such additional "features"
4187 when choosing the configuration, i. e.
4190 - will configure for a plain TQM823L, i. e. no LCD support
4192 make TQM823L_LCD_config
4193 - will configure for a TQM823L with U-Boot console on LCD
4198 Finally, type "make all", and you should get some working U-Boot
4199 images ready for download to / installation on your system:
4201 - "u-boot.bin" is a raw binary image
4202 - "u-boot" is an image in ELF binary format
4203 - "u-boot.srec" is in Motorola S-Record format
4205 By default the build is performed locally and the objects are saved
4206 in the source directory. One of the two methods can be used to change
4207 this behavior and build U-Boot to some external directory:
4209 1. Add O= to the make command line invocations:
4211 make O=/tmp/build distclean
4212 make O=/tmp/build NAME_config
4213 make O=/tmp/build all
4215 2. Set environment variable BUILD_DIR to point to the desired location:
4217 export BUILD_DIR=/tmp/build
4222 Note that the command line "O=" setting overrides the BUILD_DIR environment
4226 Please be aware that the Makefiles assume you are using GNU make, so
4227 for instance on NetBSD you might need to use "gmake" instead of
4231 If the system board that you have is not listed, then you will need
4232 to port U-Boot to your hardware platform. To do this, follow these
4235 1. Add a new configuration option for your board to the toplevel
4236 "boards.cfg" file, using the existing entries as examples.
4237 Follow the instructions there to keep the boards in order.
4238 2. Create a new directory to hold your board specific code. Add any
4239 files you need. In your board directory, you will need at least
4240 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4241 3. Create a new configuration file "include/configs/<board>.h" for
4243 3. If you're porting U-Boot to a new CPU, then also create a new
4244 directory to hold your CPU specific code. Add any files you need.
4245 4. Run "make <board>_config" with your new name.
4246 5. Type "make", and you should get a working "u-boot.srec" file
4247 to be installed on your target system.
4248 6. Debug and solve any problems that might arise.
4249 [Of course, this last step is much harder than it sounds.]
4252 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4253 ==============================================================
4255 If you have modified U-Boot sources (for instance added a new board
4256 or support for new devices, a new CPU, etc.) you are expected to
4257 provide feedback to the other developers. The feedback normally takes
4258 the form of a "patch", i. e. a context diff against a certain (latest
4259 official or latest in the git repository) version of U-Boot sources.
4261 But before you submit such a patch, please verify that your modifi-
4262 cation did not break existing code. At least make sure that *ALL* of
4263 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4264 just run the "MAKEALL" script, which will configure and build U-Boot
4265 for ALL supported system. Be warned, this will take a while. You can
4266 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4267 environment variable to the script, i. e. to use the ELDK cross tools
4270 CROSS_COMPILE=ppc_8xx- MAKEALL
4272 or to build on a native PowerPC system you can type
4274 CROSS_COMPILE=' ' MAKEALL
4276 When using the MAKEALL script, the default behaviour is to build
4277 U-Boot in the source directory. This location can be changed by
4278 setting the BUILD_DIR environment variable. Also, for each target
4279 built, the MAKEALL script saves two log files (<target>.ERR and
4280 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4281 location can be changed by setting the MAKEALL_LOGDIR environment
4282 variable. For example:
4284 export BUILD_DIR=/tmp/build
4285 export MAKEALL_LOGDIR=/tmp/log
4286 CROSS_COMPILE=ppc_8xx- MAKEALL
4288 With the above settings build objects are saved in the /tmp/build,
4289 log files are saved in the /tmp/log and the source tree remains clean
4290 during the whole build process.
4293 See also "U-Boot Porting Guide" below.
4296 Monitor Commands - Overview:
4297 ============================
4299 go - start application at address 'addr'
4300 run - run commands in an environment variable
4301 bootm - boot application image from memory
4302 bootp - boot image via network using BootP/TFTP protocol
4303 bootz - boot zImage from memory
4304 tftpboot- boot image via network using TFTP protocol
4305 and env variables "ipaddr" and "serverip"
4306 (and eventually "gatewayip")
4307 tftpput - upload a file via network using TFTP protocol
4308 rarpboot- boot image via network using RARP/TFTP protocol
4309 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4310 loads - load S-Record file over serial line
4311 loadb - load binary file over serial line (kermit mode)
4313 mm - memory modify (auto-incrementing)
4314 nm - memory modify (constant address)
4315 mw - memory write (fill)
4317 cmp - memory compare
4318 crc32 - checksum calculation
4319 i2c - I2C sub-system
4320 sspi - SPI utility commands
4321 base - print or set address offset
4322 printenv- print environment variables
4323 setenv - set environment variables
4324 saveenv - save environment variables to persistent storage
4325 protect - enable or disable FLASH write protection
4326 erase - erase FLASH memory
4327 flinfo - print FLASH memory information
4328 nand - NAND memory operations (see doc/README.nand)
4329 bdinfo - print Board Info structure
4330 iminfo - print header information for application image
4331 coninfo - print console devices and informations
4332 ide - IDE sub-system
4333 loop - infinite loop on address range
4334 loopw - infinite write loop on address range
4335 mtest - simple RAM test
4336 icache - enable or disable instruction cache
4337 dcache - enable or disable data cache
4338 reset - Perform RESET of the CPU
4339 echo - echo args to console
4340 version - print monitor version
4341 help - print online help
4342 ? - alias for 'help'
4345 Monitor Commands - Detailed Description:
4346 ========================================
4350 For now: just type "help <command>".
4353 Environment Variables:
4354 ======================
4356 U-Boot supports user configuration using Environment Variables which
4357 can be made persistent by saving to Flash memory.
4359 Environment Variables are set using "setenv", printed using
4360 "printenv", and saved to Flash using "saveenv". Using "setenv"
4361 without a value can be used to delete a variable from the
4362 environment. As long as you don't save the environment you are
4363 working with an in-memory copy. In case the Flash area containing the
4364 environment is erased by accident, a default environment is provided.
4366 Some configuration options can be set using Environment Variables.
4368 List of environment variables (most likely not complete):
4370 baudrate - see CONFIG_BAUDRATE
4372 bootdelay - see CONFIG_BOOTDELAY
4374 bootcmd - see CONFIG_BOOTCOMMAND
4376 bootargs - Boot arguments when booting an RTOS image
4378 bootfile - Name of the image to load with TFTP
4380 bootm_low - Memory range available for image processing in the bootm
4381 command can be restricted. This variable is given as
4382 a hexadecimal number and defines lowest address allowed
4383 for use by the bootm command. See also "bootm_size"
4384 environment variable. Address defined by "bootm_low" is
4385 also the base of the initial memory mapping for the Linux
4386 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4389 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4390 This variable is given as a hexadecimal number and it
4391 defines the size of the memory region starting at base
4392 address bootm_low that is accessible by the Linux kernel
4393 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4394 as the default value if it is defined, and bootm_size is
4397 bootm_size - Memory range available for image processing in the bootm
4398 command can be restricted. This variable is given as
4399 a hexadecimal number and defines the size of the region
4400 allowed for use by the bootm command. See also "bootm_low"
4401 environment variable.
4403 updatefile - Location of the software update file on a TFTP server, used
4404 by the automatic software update feature. Please refer to
4405 documentation in doc/README.update for more details.
4407 autoload - if set to "no" (any string beginning with 'n'),
4408 "bootp" will just load perform a lookup of the
4409 configuration from the BOOTP server, but not try to
4410 load any image using TFTP
4412 autostart - if set to "yes", an image loaded using the "bootp",
4413 "rarpboot", "tftpboot" or "diskboot" commands will
4414 be automatically started (by internally calling
4417 If set to "no", a standalone image passed to the
4418 "bootm" command will be copied to the load address
4419 (and eventually uncompressed), but NOT be started.
4420 This can be used to load and uncompress arbitrary
4423 fdt_high - if set this restricts the maximum address that the
4424 flattened device tree will be copied into upon boot.
4425 For example, if you have a system with 1 GB memory
4426 at physical address 0x10000000, while Linux kernel
4427 only recognizes the first 704 MB as low memory, you
4428 may need to set fdt_high as 0x3C000000 to have the
4429 device tree blob be copied to the maximum address
4430 of the 704 MB low memory, so that Linux kernel can
4431 access it during the boot procedure.
4433 If this is set to the special value 0xFFFFFFFF then
4434 the fdt will not be copied at all on boot. For this
4435 to work it must reside in writable memory, have
4436 sufficient padding on the end of it for u-boot to
4437 add the information it needs into it, and the memory
4438 must be accessible by the kernel.
4440 fdtcontroladdr- if set this is the address of the control flattened
4441 device tree used by U-Boot when CONFIG_OF_CONTROL is
4444 i2cfast - (PPC405GP|PPC405EP only)
4445 if set to 'y' configures Linux I2C driver for fast
4446 mode (400kHZ). This environment variable is used in
4447 initialization code. So, for changes to be effective
4448 it must be saved and board must be reset.
4450 initrd_high - restrict positioning of initrd images:
4451 If this variable is not set, initrd images will be
4452 copied to the highest possible address in RAM; this
4453 is usually what you want since it allows for
4454 maximum initrd size. If for some reason you want to
4455 make sure that the initrd image is loaded below the
4456 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4457 variable to a value of "no" or "off" or "0".
4458 Alternatively, you can set it to a maximum upper
4459 address to use (U-Boot will still check that it
4460 does not overwrite the U-Boot stack and data).
4462 For instance, when you have a system with 16 MB
4463 RAM, and want to reserve 4 MB from use by Linux,
4464 you can do this by adding "mem=12M" to the value of
4465 the "bootargs" variable. However, now you must make
4466 sure that the initrd image is placed in the first
4467 12 MB as well - this can be done with
4469 setenv initrd_high 00c00000
4471 If you set initrd_high to 0xFFFFFFFF, this is an
4472 indication to U-Boot that all addresses are legal
4473 for the Linux kernel, including addresses in flash
4474 memory. In this case U-Boot will NOT COPY the
4475 ramdisk at all. This may be useful to reduce the
4476 boot time on your system, but requires that this
4477 feature is supported by your Linux kernel.
4479 ipaddr - IP address; needed for tftpboot command
4481 loadaddr - Default load address for commands like "bootp",
4482 "rarpboot", "tftpboot", "loadb" or "diskboot"
4484 loads_echo - see CONFIG_LOADS_ECHO
4486 serverip - TFTP server IP address; needed for tftpboot command
4488 bootretry - see CONFIG_BOOT_RETRY_TIME
4490 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4492 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4494 ethprime - controls which interface is used first.
4496 ethact - controls which interface is currently active.
4497 For example you can do the following
4499 => setenv ethact FEC
4500 => ping 192.168.0.1 # traffic sent on FEC
4501 => setenv ethact SCC
4502 => ping 10.0.0.1 # traffic sent on SCC
4504 ethrotate - When set to "no" U-Boot does not go through all
4505 available network interfaces.
4506 It just stays at the currently selected interface.
4508 netretry - When set to "no" each network operation will
4509 either succeed or fail without retrying.
4510 When set to "once" the network operation will
4511 fail when all the available network interfaces
4512 are tried once without success.
4513 Useful on scripts which control the retry operation
4516 npe_ucode - set load address for the NPE microcode
4518 tftpsrcport - If this is set, the value is used for TFTP's
4521 tftpdstport - If this is set, the value is used for TFTP's UDP
4522 destination port instead of the Well Know Port 69.
4524 tftpblocksize - Block size to use for TFTP transfers; if not set,
4525 we use the TFTP server's default block size
4527 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4528 seconds, minimum value is 1000 = 1 second). Defines
4529 when a packet is considered to be lost so it has to
4530 be retransmitted. The default is 5000 = 5 seconds.
4531 Lowering this value may make downloads succeed
4532 faster in networks with high packet loss rates or
4533 with unreliable TFTP servers.
4535 vlan - When set to a value < 4095 the traffic over
4536 Ethernet is encapsulated/received over 802.1q
4539 The following image location variables contain the location of images
4540 used in booting. The "Image" column gives the role of the image and is
4541 not an environment variable name. The other columns are environment
4542 variable names. "File Name" gives the name of the file on a TFTP
4543 server, "RAM Address" gives the location in RAM the image will be
4544 loaded to, and "Flash Location" gives the image's address in NOR
4545 flash or offset in NAND flash.
4547 *Note* - these variables don't have to be defined for all boards, some
4548 boards currenlty use other variables for these purposes, and some
4549 boards use these variables for other purposes.
4551 Image File Name RAM Address Flash Location
4552 ----- --------- ----------- --------------
4553 u-boot u-boot u-boot_addr_r u-boot_addr
4554 Linux kernel bootfile kernel_addr_r kernel_addr
4555 device tree blob fdtfile fdt_addr_r fdt_addr
4556 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4558 The following environment variables may be used and automatically
4559 updated by the network boot commands ("bootp" and "rarpboot"),
4560 depending the information provided by your boot server:
4562 bootfile - see above
4563 dnsip - IP address of your Domain Name Server
4564 dnsip2 - IP address of your secondary Domain Name Server
4565 gatewayip - IP address of the Gateway (Router) to use
4566 hostname - Target hostname
4568 netmask - Subnet Mask
4569 rootpath - Pathname of the root filesystem on the NFS server
4570 serverip - see above
4573 There are two special Environment Variables:
4575 serial# - contains hardware identification information such
4576 as type string and/or serial number
4577 ethaddr - Ethernet address
4579 These variables can be set only once (usually during manufacturing of
4580 the board). U-Boot refuses to delete or overwrite these variables
4581 once they have been set once.
4584 Further special Environment Variables:
4586 ver - Contains the U-Boot version string as printed
4587 with the "version" command. This variable is
4588 readonly (see CONFIG_VERSION_VARIABLE).
4591 Please note that changes to some configuration parameters may take
4592 only effect after the next boot (yes, that's just like Windoze :-).
4595 Callback functions for environment variables:
4596 ---------------------------------------------
4598 For some environment variables, the behavior of u-boot needs to change
4599 when their values are changed. This functionailty allows functions to
4600 be associated with arbitrary variables. On creation, overwrite, or
4601 deletion, the callback will provide the opportunity for some side
4602 effect to happen or for the change to be rejected.
4604 The callbacks are named and associated with a function using the
4605 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4607 These callbacks are associated with variables in one of two ways. The
4608 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4609 in the board configuration to a string that defines a list of
4610 associations. The list must be in the following format:
4612 entry = variable_name[:callback_name]
4615 If the callback name is not specified, then the callback is deleted.
4616 Spaces are also allowed anywhere in the list.
4618 Callbacks can also be associated by defining the ".callbacks" variable
4619 with the same list format above. Any association in ".callbacks" will
4620 override any association in the static list. You can define
4621 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4622 ".callbacks" envirnoment variable in the default or embedded environment.
4625 Command Line Parsing:
4626 =====================
4628 There are two different command line parsers available with U-Boot:
4629 the old "simple" one, and the much more powerful "hush" shell:
4631 Old, simple command line parser:
4632 --------------------------------
4634 - supports environment variables (through setenv / saveenv commands)
4635 - several commands on one line, separated by ';'
4636 - variable substitution using "... ${name} ..." syntax
4637 - special characters ('$', ';') can be escaped by prefixing with '\',
4639 setenv bootcmd bootm \${address}
4640 - You can also escape text by enclosing in single apostrophes, for example:
4641 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4646 - similar to Bourne shell, with control structures like
4647 if...then...else...fi, for...do...done; while...do...done,
4648 until...do...done, ...
4649 - supports environment ("global") variables (through setenv / saveenv
4650 commands) and local shell variables (through standard shell syntax
4651 "name=value"); only environment variables can be used with "run"
4657 (1) If a command line (or an environment variable executed by a "run"
4658 command) contains several commands separated by semicolon, and
4659 one of these commands fails, then the remaining commands will be
4662 (2) If you execute several variables with one call to run (i. e.
4663 calling run with a list of variables as arguments), any failing
4664 command will cause "run" to terminate, i. e. the remaining
4665 variables are not executed.
4667 Note for Redundant Ethernet Interfaces:
4668 =======================================
4670 Some boards come with redundant Ethernet interfaces; U-Boot supports
4671 such configurations and is capable of automatic selection of a
4672 "working" interface when needed. MAC assignment works as follows:
4674 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4675 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4676 "eth1addr" (=>eth1), "eth2addr", ...
4678 If the network interface stores some valid MAC address (for instance
4679 in SROM), this is used as default address if there is NO correspon-
4680 ding setting in the environment; if the corresponding environment
4681 variable is set, this overrides the settings in the card; that means:
4683 o If the SROM has a valid MAC address, and there is no address in the
4684 environment, the SROM's address is used.
4686 o If there is no valid address in the SROM, and a definition in the
4687 environment exists, then the value from the environment variable is
4690 o If both the SROM and the environment contain a MAC address, and
4691 both addresses are the same, this MAC address is used.
4693 o If both the SROM and the environment contain a MAC address, and the
4694 addresses differ, the value from the environment is used and a
4697 o If neither SROM nor the environment contain a MAC address, an error
4700 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4701 will be programmed into hardware as part of the initialization process. This
4702 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4703 The naming convention is as follows:
4704 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4709 U-Boot is capable of booting (and performing other auxiliary operations on)
4710 images in two formats:
4712 New uImage format (FIT)
4713 -----------------------
4715 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4716 to Flattened Device Tree). It allows the use of images with multiple
4717 components (several kernels, ramdisks, etc.), with contents protected by
4718 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4724 Old image format is based on binary files which can be basically anything,
4725 preceded by a special header; see the definitions in include/image.h for
4726 details; basically, the header defines the following image properties:
4728 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4729 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4730 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4731 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4733 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4734 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4735 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4736 * Compression Type (uncompressed, gzip, bzip2)
4742 The header is marked by a special Magic Number, and both the header
4743 and the data portions of the image are secured against corruption by
4750 Although U-Boot should support any OS or standalone application
4751 easily, the main focus has always been on Linux during the design of
4754 U-Boot includes many features that so far have been part of some
4755 special "boot loader" code within the Linux kernel. Also, any
4756 "initrd" images to be used are no longer part of one big Linux image;
4757 instead, kernel and "initrd" are separate images. This implementation
4758 serves several purposes:
4760 - the same features can be used for other OS or standalone
4761 applications (for instance: using compressed images to reduce the
4762 Flash memory footprint)
4764 - it becomes much easier to port new Linux kernel versions because
4765 lots of low-level, hardware dependent stuff are done by U-Boot
4767 - the same Linux kernel image can now be used with different "initrd"
4768 images; of course this also means that different kernel images can
4769 be run with the same "initrd". This makes testing easier (you don't
4770 have to build a new "zImage.initrd" Linux image when you just
4771 change a file in your "initrd"). Also, a field-upgrade of the
4772 software is easier now.
4778 Porting Linux to U-Boot based systems:
4779 ---------------------------------------
4781 U-Boot cannot save you from doing all the necessary modifications to
4782 configure the Linux device drivers for use with your target hardware
4783 (no, we don't intend to provide a full virtual machine interface to
4786 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4788 Just make sure your machine specific header file (for instance
4789 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4790 Information structure as we define in include/asm-<arch>/u-boot.h,
4791 and make sure that your definition of IMAP_ADDR uses the same value
4792 as your U-Boot configuration in CONFIG_SYS_IMMR.
4795 Configuring the Linux kernel:
4796 -----------------------------
4798 No specific requirements for U-Boot. Make sure you have some root
4799 device (initial ramdisk, NFS) for your target system.
4802 Building a Linux Image:
4803 -----------------------
4805 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4806 not used. If you use recent kernel source, a new build target
4807 "uImage" will exist which automatically builds an image usable by
4808 U-Boot. Most older kernels also have support for a "pImage" target,
4809 which was introduced for our predecessor project PPCBoot and uses a
4810 100% compatible format.
4819 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4820 encapsulate a compressed Linux kernel image with header information,
4821 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4823 * build a standard "vmlinux" kernel image (in ELF binary format):
4825 * convert the kernel into a raw binary image:
4827 ${CROSS_COMPILE}-objcopy -O binary \
4828 -R .note -R .comment \
4829 -S vmlinux linux.bin
4831 * compress the binary image:
4835 * package compressed binary image for U-Boot:
4837 mkimage -A ppc -O linux -T kernel -C gzip \
4838 -a 0 -e 0 -n "Linux Kernel Image" \
4839 -d linux.bin.gz uImage
4842 The "mkimage" tool can also be used to create ramdisk images for use
4843 with U-Boot, either separated from the Linux kernel image, or
4844 combined into one file. "mkimage" encapsulates the images with a 64
4845 byte header containing information about target architecture,
4846 operating system, image type, compression method, entry points, time
4847 stamp, CRC32 checksums, etc.
4849 "mkimage" can be called in two ways: to verify existing images and
4850 print the header information, or to build new images.
4852 In the first form (with "-l" option) mkimage lists the information
4853 contained in the header of an existing U-Boot image; this includes
4854 checksum verification:
4856 tools/mkimage -l image
4857 -l ==> list image header information
4859 The second form (with "-d" option) is used to build a U-Boot image
4860 from a "data file" which is used as image payload:
4862 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4863 -n name -d data_file image
4864 -A ==> set architecture to 'arch'
4865 -O ==> set operating system to 'os'
4866 -T ==> set image type to 'type'
4867 -C ==> set compression type 'comp'
4868 -a ==> set load address to 'addr' (hex)
4869 -e ==> set entry point to 'ep' (hex)
4870 -n ==> set image name to 'name'
4871 -d ==> use image data from 'datafile'
4873 Right now, all Linux kernels for PowerPC systems use the same load
4874 address (0x00000000), but the entry point address depends on the
4877 - 2.2.x kernels have the entry point at 0x0000000C,
4878 - 2.3.x and later kernels have the entry point at 0x00000000.
4880 So a typical call to build a U-Boot image would read:
4882 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4883 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4884 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4885 > examples/uImage.TQM850L
4886 Image Name: 2.4.4 kernel for TQM850L
4887 Created: Wed Jul 19 02:34:59 2000
4888 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4889 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4890 Load Address: 0x00000000
4891 Entry Point: 0x00000000
4893 To verify the contents of the image (or check for corruption):
4895 -> tools/mkimage -l examples/uImage.TQM850L
4896 Image Name: 2.4.4 kernel for TQM850L
4897 Created: Wed Jul 19 02:34:59 2000
4898 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4899 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4900 Load Address: 0x00000000
4901 Entry Point: 0x00000000
4903 NOTE: for embedded systems where boot time is critical you can trade
4904 speed for memory and install an UNCOMPRESSED image instead: this
4905 needs more space in Flash, but boots much faster since it does not
4906 need to be uncompressed:
4908 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4909 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4910 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4911 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4912 > examples/uImage.TQM850L-uncompressed
4913 Image Name: 2.4.4 kernel for TQM850L
4914 Created: Wed Jul 19 02:34:59 2000
4915 Image Type: PowerPC Linux Kernel Image (uncompressed)
4916 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4917 Load Address: 0x00000000
4918 Entry Point: 0x00000000
4921 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4922 when your kernel is intended to use an initial ramdisk:
4924 -> tools/mkimage -n 'Simple Ramdisk Image' \
4925 > -A ppc -O linux -T ramdisk -C gzip \
4926 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4927 Image Name: Simple Ramdisk Image
4928 Created: Wed Jan 12 14:01:50 2000
4929 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4930 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4931 Load Address: 0x00000000
4932 Entry Point: 0x00000000
4935 Installing a Linux Image:
4936 -------------------------
4938 To downloading a U-Boot image over the serial (console) interface,
4939 you must convert the image to S-Record format:
4941 objcopy -I binary -O srec examples/image examples/image.srec
4943 The 'objcopy' does not understand the information in the U-Boot
4944 image header, so the resulting S-Record file will be relative to
4945 address 0x00000000. To load it to a given address, you need to
4946 specify the target address as 'offset' parameter with the 'loads'
4949 Example: install the image to address 0x40100000 (which on the
4950 TQM8xxL is in the first Flash bank):
4952 => erase 40100000 401FFFFF
4958 ## Ready for S-Record download ...
4959 ~>examples/image.srec
4960 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4962 15989 15990 15991 15992
4963 [file transfer complete]
4965 ## Start Addr = 0x00000000
4968 You can check the success of the download using the 'iminfo' command;
4969 this includes a checksum verification so you can be sure no data
4970 corruption happened:
4974 ## Checking Image at 40100000 ...
4975 Image Name: 2.2.13 for initrd on TQM850L
4976 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4977 Data Size: 335725 Bytes = 327 kB = 0 MB
4978 Load Address: 00000000
4979 Entry Point: 0000000c
4980 Verifying Checksum ... OK
4986 The "bootm" command is used to boot an application that is stored in
4987 memory (RAM or Flash). In case of a Linux kernel image, the contents
4988 of the "bootargs" environment variable is passed to the kernel as
4989 parameters. You can check and modify this variable using the
4990 "printenv" and "setenv" commands:
4993 => printenv bootargs
4994 bootargs=root=/dev/ram
4996 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4998 => printenv bootargs
4999 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5002 ## Booting Linux kernel at 40020000 ...
5003 Image Name: 2.2.13 for NFS on TQM850L
5004 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5005 Data Size: 381681 Bytes = 372 kB = 0 MB
5006 Load Address: 00000000
5007 Entry Point: 0000000c
5008 Verifying Checksum ... OK
5009 Uncompressing Kernel Image ... OK
5010 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5011 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5012 time_init: decrementer frequency = 187500000/60
5013 Calibrating delay loop... 49.77 BogoMIPS
5014 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5017 If you want to boot a Linux kernel with initial RAM disk, you pass
5018 the memory addresses of both the kernel and the initrd image (PPBCOOT
5019 format!) to the "bootm" command:
5021 => imi 40100000 40200000
5023 ## Checking Image at 40100000 ...
5024 Image Name: 2.2.13 for initrd on TQM850L
5025 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5026 Data Size: 335725 Bytes = 327 kB = 0 MB
5027 Load Address: 00000000
5028 Entry Point: 0000000c
5029 Verifying Checksum ... OK
5031 ## Checking Image at 40200000 ...
5032 Image Name: Simple Ramdisk Image
5033 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5034 Data Size: 566530 Bytes = 553 kB = 0 MB
5035 Load Address: 00000000
5036 Entry Point: 00000000
5037 Verifying Checksum ... OK
5039 => bootm 40100000 40200000
5040 ## Booting Linux kernel at 40100000 ...
5041 Image Name: 2.2.13 for initrd on TQM850L
5042 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5043 Data Size: 335725 Bytes = 327 kB = 0 MB
5044 Load Address: 00000000
5045 Entry Point: 0000000c
5046 Verifying Checksum ... OK
5047 Uncompressing Kernel Image ... OK
5048 ## Loading RAMDisk Image at 40200000 ...
5049 Image Name: Simple Ramdisk Image
5050 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5051 Data Size: 566530 Bytes = 553 kB = 0 MB
5052 Load Address: 00000000
5053 Entry Point: 00000000
5054 Verifying Checksum ... OK
5055 Loading Ramdisk ... OK
5056 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5057 Boot arguments: root=/dev/ram
5058 time_init: decrementer frequency = 187500000/60
5059 Calibrating delay loop... 49.77 BogoMIPS
5061 RAMDISK: Compressed image found at block 0
5062 VFS: Mounted root (ext2 filesystem).
5066 Boot Linux and pass a flat device tree:
5069 First, U-Boot must be compiled with the appropriate defines. See the section
5070 titled "Linux Kernel Interface" above for a more in depth explanation. The
5071 following is an example of how to start a kernel and pass an updated
5077 oft=oftrees/mpc8540ads.dtb
5078 => tftp $oftaddr $oft
5079 Speed: 1000, full duplex
5081 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5082 Filename 'oftrees/mpc8540ads.dtb'.
5083 Load address: 0x300000
5086 Bytes transferred = 4106 (100a hex)
5087 => tftp $loadaddr $bootfile
5088 Speed: 1000, full duplex
5090 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5092 Load address: 0x200000
5093 Loading:############
5095 Bytes transferred = 1029407 (fb51f hex)
5100 => bootm $loadaddr - $oftaddr
5101 ## Booting image at 00200000 ...
5102 Image Name: Linux-2.6.17-dirty
5103 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5104 Data Size: 1029343 Bytes = 1005.2 kB
5105 Load Address: 00000000
5106 Entry Point: 00000000
5107 Verifying Checksum ... OK
5108 Uncompressing Kernel Image ... OK
5109 Booting using flat device tree at 0x300000
5110 Using MPC85xx ADS machine description
5111 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5115 More About U-Boot Image Types:
5116 ------------------------------
5118 U-Boot supports the following image types:
5120 "Standalone Programs" are directly runnable in the environment
5121 provided by U-Boot; it is expected that (if they behave
5122 well) you can continue to work in U-Boot after return from
5123 the Standalone Program.
5124 "OS Kernel Images" are usually images of some Embedded OS which
5125 will take over control completely. Usually these programs
5126 will install their own set of exception handlers, device
5127 drivers, set up the MMU, etc. - this means, that you cannot
5128 expect to re-enter U-Boot except by resetting the CPU.
5129 "RAMDisk Images" are more or less just data blocks, and their
5130 parameters (address, size) are passed to an OS kernel that is
5132 "Multi-File Images" contain several images, typically an OS
5133 (Linux) kernel image and one or more data images like
5134 RAMDisks. This construct is useful for instance when you want
5135 to boot over the network using BOOTP etc., where the boot
5136 server provides just a single image file, but you want to get
5137 for instance an OS kernel and a RAMDisk image.
5139 "Multi-File Images" start with a list of image sizes, each
5140 image size (in bytes) specified by an "uint32_t" in network
5141 byte order. This list is terminated by an "(uint32_t)0".
5142 Immediately after the terminating 0 follow the images, one by
5143 one, all aligned on "uint32_t" boundaries (size rounded up to
5144 a multiple of 4 bytes).
5146 "Firmware Images" are binary images containing firmware (like
5147 U-Boot or FPGA images) which usually will be programmed to
5150 "Script files" are command sequences that will be executed by
5151 U-Boot's command interpreter; this feature is especially
5152 useful when you configure U-Boot to use a real shell (hush)
5153 as command interpreter.
5155 Booting the Linux zImage:
5156 -------------------------
5158 On some platforms, it's possible to boot Linux zImage. This is done
5159 using the "bootz" command. The syntax of "bootz" command is the same
5160 as the syntax of "bootm" command.
5162 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5163 kernel with raw initrd images. The syntax is slightly different, the
5164 address of the initrd must be augmented by it's size, in the following
5165 format: "<initrd addres>:<initrd size>".
5171 One of the features of U-Boot is that you can dynamically load and
5172 run "standalone" applications, which can use some resources of
5173 U-Boot like console I/O functions or interrupt services.
5175 Two simple examples are included with the sources:
5180 'examples/hello_world.c' contains a small "Hello World" Demo
5181 application; it is automatically compiled when you build U-Boot.
5182 It's configured to run at address 0x00040004, so you can play with it
5186 ## Ready for S-Record download ...
5187 ~>examples/hello_world.srec
5188 1 2 3 4 5 6 7 8 9 10 11 ...
5189 [file transfer complete]
5191 ## Start Addr = 0x00040004
5193 => go 40004 Hello World! This is a test.
5194 ## Starting application at 0x00040004 ...
5205 Hit any key to exit ...
5207 ## Application terminated, rc = 0x0
5209 Another example, which demonstrates how to register a CPM interrupt
5210 handler with the U-Boot code, can be found in 'examples/timer.c'.
5211 Here, a CPM timer is set up to generate an interrupt every second.
5212 The interrupt service routine is trivial, just printing a '.'
5213 character, but this is just a demo program. The application can be
5214 controlled by the following keys:
5216 ? - print current values og the CPM Timer registers
5217 b - enable interrupts and start timer
5218 e - stop timer and disable interrupts
5219 q - quit application
5222 ## Ready for S-Record download ...
5223 ~>examples/timer.srec
5224 1 2 3 4 5 6 7 8 9 10 11 ...
5225 [file transfer complete]
5227 ## Start Addr = 0x00040004
5230 ## Starting application at 0x00040004 ...
5233 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5236 [q, b, e, ?] Set interval 1000000 us
5239 [q, b, e, ?] ........
5240 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5243 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5246 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5249 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5251 [q, b, e, ?] ...Stopping timer
5253 [q, b, e, ?] ## Application terminated, rc = 0x0
5259 Over time, many people have reported problems when trying to use the
5260 "minicom" terminal emulation program for serial download. I (wd)
5261 consider minicom to be broken, and recommend not to use it. Under
5262 Unix, I recommend to use C-Kermit for general purpose use (and
5263 especially for kermit binary protocol download ("loadb" command), and
5264 use "cu" for S-Record download ("loads" command). See
5265 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5266 for help with kermit.
5269 Nevertheless, if you absolutely want to use it try adding this
5270 configuration to your "File transfer protocols" section:
5272 Name Program Name U/D FullScr IO-Red. Multi
5273 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5274 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5280 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5281 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5283 Building requires a cross environment; it is known to work on
5284 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5285 need gmake since the Makefiles are not compatible with BSD make).
5286 Note that the cross-powerpc package does not install include files;
5287 attempting to build U-Boot will fail because <machine/ansi.h> is
5288 missing. This file has to be installed and patched manually:
5290 # cd /usr/pkg/cross/powerpc-netbsd/include
5292 # ln -s powerpc machine
5293 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5294 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5296 Native builds *don't* work due to incompatibilities between native
5297 and U-Boot include files.
5299 Booting assumes that (the first part of) the image booted is a
5300 stage-2 loader which in turn loads and then invokes the kernel
5301 proper. Loader sources will eventually appear in the NetBSD source
5302 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5303 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5306 Implementation Internals:
5307 =========================
5309 The following is not intended to be a complete description of every
5310 implementation detail. However, it should help to understand the
5311 inner workings of U-Boot and make it easier to port it to custom
5315 Initial Stack, Global Data:
5316 ---------------------------
5318 The implementation of U-Boot is complicated by the fact that U-Boot
5319 starts running out of ROM (flash memory), usually without access to
5320 system RAM (because the memory controller is not initialized yet).
5321 This means that we don't have writable Data or BSS segments, and BSS
5322 is not initialized as zero. To be able to get a C environment working
5323 at all, we have to allocate at least a minimal stack. Implementation
5324 options for this are defined and restricted by the CPU used: Some CPU
5325 models provide on-chip memory (like the IMMR area on MPC8xx and
5326 MPC826x processors), on others (parts of) the data cache can be
5327 locked as (mis-) used as memory, etc.
5329 Chris Hallinan posted a good summary of these issues to the
5330 U-Boot mailing list:
5332 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5334 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5337 Correct me if I'm wrong, folks, but the way I understand it
5338 is this: Using DCACHE as initial RAM for Stack, etc, does not
5339 require any physical RAM backing up the cache. The cleverness
5340 is that the cache is being used as a temporary supply of
5341 necessary storage before the SDRAM controller is setup. It's
5342 beyond the scope of this list to explain the details, but you
5343 can see how this works by studying the cache architecture and
5344 operation in the architecture and processor-specific manuals.
5346 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5347 is another option for the system designer to use as an
5348 initial stack/RAM area prior to SDRAM being available. Either
5349 option should work for you. Using CS 4 should be fine if your
5350 board designers haven't used it for something that would
5351 cause you grief during the initial boot! It is frequently not
5354 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5355 with your processor/board/system design. The default value
5356 you will find in any recent u-boot distribution in
5357 walnut.h should work for you. I'd set it to a value larger
5358 than your SDRAM module. If you have a 64MB SDRAM module, set
5359 it above 400_0000. Just make sure your board has no resources
5360 that are supposed to respond to that address! That code in
5361 start.S has been around a while and should work as is when
5362 you get the config right.
5367 It is essential to remember this, since it has some impact on the C
5368 code for the initialization procedures:
5370 * Initialized global data (data segment) is read-only. Do not attempt
5373 * Do not use any uninitialized global data (or implicitely initialized
5374 as zero data - BSS segment) at all - this is undefined, initiali-
5375 zation is performed later (when relocating to RAM).
5377 * Stack space is very limited. Avoid big data buffers or things like
5380 Having only the stack as writable memory limits means we cannot use
5381 normal global data to share information beween the code. But it
5382 turned out that the implementation of U-Boot can be greatly
5383 simplified by making a global data structure (gd_t) available to all
5384 functions. We could pass a pointer to this data as argument to _all_
5385 functions, but this would bloat the code. Instead we use a feature of
5386 the GCC compiler (Global Register Variables) to share the data: we
5387 place a pointer (gd) to the global data into a register which we
5388 reserve for this purpose.
5390 When choosing a register for such a purpose we are restricted by the
5391 relevant (E)ABI specifications for the current architecture, and by
5392 GCC's implementation.
5394 For PowerPC, the following registers have specific use:
5396 R2: reserved for system use
5397 R3-R4: parameter passing and return values
5398 R5-R10: parameter passing
5399 R13: small data area pointer
5403 (U-Boot also uses R12 as internal GOT pointer. r12
5404 is a volatile register so r12 needs to be reset when
5405 going back and forth between asm and C)
5407 ==> U-Boot will use R2 to hold a pointer to the global data
5409 Note: on PPC, we could use a static initializer (since the
5410 address of the global data structure is known at compile time),
5411 but it turned out that reserving a register results in somewhat
5412 smaller code - although the code savings are not that big (on
5413 average for all boards 752 bytes for the whole U-Boot image,
5414 624 text + 127 data).
5416 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5417 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5419 ==> U-Boot will use P3 to hold a pointer to the global data
5421 On ARM, the following registers are used:
5423 R0: function argument word/integer result
5424 R1-R3: function argument word
5426 R10: stack limit (used only if stack checking if enabled)
5427 R11: argument (frame) pointer
5428 R12: temporary workspace
5431 R15: program counter
5433 ==> U-Boot will use R8 to hold a pointer to the global data
5435 On Nios II, the ABI is documented here:
5436 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5438 ==> U-Boot will use gp to hold a pointer to the global data
5440 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5441 to access small data sections, so gp is free.
5443 On NDS32, the following registers are used:
5445 R0-R1: argument/return
5447 R15: temporary register for assembler
5448 R16: trampoline register
5449 R28: frame pointer (FP)
5450 R29: global pointer (GP)
5451 R30: link register (LP)
5452 R31: stack pointer (SP)
5453 PC: program counter (PC)
5455 ==> U-Boot will use R10 to hold a pointer to the global data
5457 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5458 or current versions of GCC may "optimize" the code too much.
5463 U-Boot runs in system state and uses physical addresses, i.e. the
5464 MMU is not used either for address mapping nor for memory protection.
5466 The available memory is mapped to fixed addresses using the memory
5467 controller. In this process, a contiguous block is formed for each
5468 memory type (Flash, SDRAM, SRAM), even when it consists of several
5469 physical memory banks.
5471 U-Boot is installed in the first 128 kB of the first Flash bank (on
5472 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5473 booting and sizing and initializing DRAM, the code relocates itself
5474 to the upper end of DRAM. Immediately below the U-Boot code some
5475 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5476 configuration setting]. Below that, a structure with global Board
5477 Info data is placed, followed by the stack (growing downward).
5479 Additionally, some exception handler code is copied to the low 8 kB
5480 of DRAM (0x00000000 ... 0x00001FFF).
5482 So a typical memory configuration with 16 MB of DRAM could look like
5485 0x0000 0000 Exception Vector code
5488 0x0000 2000 Free for Application Use
5494 0x00FB FF20 Monitor Stack (Growing downward)
5495 0x00FB FFAC Board Info Data and permanent copy of global data
5496 0x00FC 0000 Malloc Arena
5499 0x00FE 0000 RAM Copy of Monitor Code
5500 ... eventually: LCD or video framebuffer
5501 ... eventually: pRAM (Protected RAM - unchanged by reset)
5502 0x00FF FFFF [End of RAM]
5505 System Initialization:
5506 ----------------------
5508 In the reset configuration, U-Boot starts at the reset entry point
5509 (on most PowerPC systems at address 0x00000100). Because of the reset
5510 configuration for CS0# this is a mirror of the onboard Flash memory.
5511 To be able to re-map memory U-Boot then jumps to its link address.
5512 To be able to implement the initialization code in C, a (small!)
5513 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5514 which provide such a feature like MPC8xx or MPC8260), or in a locked
5515 part of the data cache. After that, U-Boot initializes the CPU core,
5516 the caches and the SIU.
5518 Next, all (potentially) available memory banks are mapped using a
5519 preliminary mapping. For example, we put them on 512 MB boundaries
5520 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5521 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5522 programmed for SDRAM access. Using the temporary configuration, a
5523 simple memory test is run that determines the size of the SDRAM
5526 When there is more than one SDRAM bank, and the banks are of
5527 different size, the largest is mapped first. For equal size, the first
5528 bank (CS2#) is mapped first. The first mapping is always for address
5529 0x00000000, with any additional banks following immediately to create
5530 contiguous memory starting from 0.
5532 Then, the monitor installs itself at the upper end of the SDRAM area
5533 and allocates memory for use by malloc() and for the global Board
5534 Info data; also, the exception vector code is copied to the low RAM
5535 pages, and the final stack is set up.
5537 Only after this relocation will you have a "normal" C environment;
5538 until that you are restricted in several ways, mostly because you are
5539 running from ROM, and because the code will have to be relocated to a
5543 U-Boot Porting Guide:
5544 ----------------------
5546 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5550 int main(int argc, char *argv[])
5552 sighandler_t no_more_time;
5554 signal(SIGALRM, no_more_time);
5555 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5557 if (available_money > available_manpower) {
5558 Pay consultant to port U-Boot;
5562 Download latest U-Boot source;
5564 Subscribe to u-boot mailing list;
5567 email("Hi, I am new to U-Boot, how do I get started?");
5570 Read the README file in the top level directory;
5571 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5572 Read applicable doc/*.README;
5573 Read the source, Luke;
5574 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5577 if (available_money > toLocalCurrency ($2500))
5580 Add a lot of aggravation and time;
5582 if (a similar board exists) { /* hopefully... */
5583 cp -a board/<similar> board/<myboard>
5584 cp include/configs/<similar>.h include/configs/<myboard>.h
5586 Create your own board support subdirectory;
5587 Create your own board include/configs/<myboard>.h file;
5589 Edit new board/<myboard> files
5590 Edit new include/configs/<myboard>.h
5595 Add / modify source code;
5599 email("Hi, I am having problems...");
5601 Send patch file to the U-Boot email list;
5602 if (reasonable critiques)
5603 Incorporate improvements from email list code review;
5605 Defend code as written;
5611 void no_more_time (int sig)
5620 All contributions to U-Boot should conform to the Linux kernel
5621 coding style; see the file "Documentation/CodingStyle" and the script
5622 "scripts/Lindent" in your Linux kernel source directory.
5624 Source files originating from a different project (for example the
5625 MTD subsystem) are generally exempt from these guidelines and are not
5626 reformated to ease subsequent migration to newer versions of those
5629 Please note that U-Boot is implemented in C (and to some small parts in
5630 Assembler); no C++ is used, so please do not use C++ style comments (//)
5633 Please also stick to the following formatting rules:
5634 - remove any trailing white space
5635 - use TAB characters for indentation and vertical alignment, not spaces
5636 - make sure NOT to use DOS '\r\n' line feeds
5637 - do not add more than 2 consecutive empty lines to source files
5638 - do not add trailing empty lines to source files
5640 Submissions which do not conform to the standards may be returned
5641 with a request to reformat the changes.
5647 Since the number of patches for U-Boot is growing, we need to
5648 establish some rules. Submissions which do not conform to these rules
5649 may be rejected, even when they contain important and valuable stuff.
5651 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5654 see http://lists.denx.de/mailman/listinfo/u-boot
5656 When you send a patch, please include the following information with
5659 * For bug fixes: a description of the bug and how your patch fixes
5660 this bug. Please try to include a way of demonstrating that the
5661 patch actually fixes something.
5663 * For new features: a description of the feature and your
5666 * A CHANGELOG entry as plaintext (separate from the patch)
5668 * For major contributions, your entry to the CREDITS file
5670 * When you add support for a new board, don't forget to add this
5671 board to the MAINTAINERS file, too.
5673 * If your patch adds new configuration options, don't forget to
5674 document these in the README file.
5676 * The patch itself. If you are using git (which is *strongly*
5677 recommended) you can easily generate the patch using the
5678 "git format-patch". If you then use "git send-email" to send it to
5679 the U-Boot mailing list, you will avoid most of the common problems
5680 with some other mail clients.
5682 If you cannot use git, use "diff -purN OLD NEW". If your version of
5683 diff does not support these options, then get the latest version of
5686 The current directory when running this command shall be the parent
5687 directory of the U-Boot source tree (i. e. please make sure that
5688 your patch includes sufficient directory information for the
5691 We prefer patches as plain text. MIME attachments are discouraged,
5692 and compressed attachments must not be used.
5694 * If one logical set of modifications affects or creates several
5695 files, all these changes shall be submitted in a SINGLE patch file.
5697 * Changesets that contain different, unrelated modifications shall be
5698 submitted as SEPARATE patches, one patch per changeset.
5703 * Before sending the patch, run the MAKEALL script on your patched
5704 source tree and make sure that no errors or warnings are reported
5705 for any of the boards.
5707 * Keep your modifications to the necessary minimum: A patch
5708 containing several unrelated changes or arbitrary reformats will be
5709 returned with a request to re-formatting / split it.
5711 * If you modify existing code, make sure that your new code does not
5712 add to the memory footprint of the code ;-) Small is beautiful!
5713 When adding new features, these should compile conditionally only
5714 (using #ifdef), and the resulting code with the new feature
5715 disabled must not need more memory than the old code without your
5718 * Remember that there is a size limit of 100 kB per message on the
5719 u-boot mailing list. Bigger patches will be moderated. If they are
5720 reasonable and not too big, they will be acknowledged. But patches
5721 bigger than the size limit should be avoided.
projects / J-u-boot.git / blob