2 # (C) Copyright 2000 - 2012
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
57 Note: There is no CHANGELOG file in the actual U-Boot source tree;
58 it can be created dynamically from the Git log using:
66 In case you have questions about, problems with or contributions for
67 U-Boot you should send a message to the U-Boot mailing list at
68 <u-boot@lists.denx.de>. There is also an archive of previous traffic
69 on the mailing list - please search the archive before asking FAQ's.
70 Please see http://lists.denx.de/pipermail/u-boot and
71 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
74 Where to get source code:
75 =========================
77 The U-Boot source code is maintained in the git repository at
78 git://www.denx.de/git/u-boot.git ; you can browse it online at
79 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
81 The "snapshot" links on this page allow you to download tarballs of
82 any version you might be interested in. Official releases are also
83 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
86 Pre-built (and tested) images are available from
87 ftp://ftp.denx.de/pub/u-boot/images/
93 - start from 8xxrom sources
94 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
96 - make it easier to add custom boards
97 - make it possible to add other [PowerPC] CPUs
98 - extend functions, especially:
99 * Provide extended interface to Linux boot loader
102 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
103 - create ARMBoot project (http://sourceforge.net/projects/armboot)
104 - add other CPU families (starting with ARM)
105 - create U-Boot project (http://sourceforge.net/projects/u-boot)
106 - current project page: see http://www.denx.de/wiki/U-Boot
112 The "official" name of this project is "Das U-Boot". The spelling
113 "U-Boot" shall be used in all written text (documentation, comments
114 in source files etc.). Example:
116 This is the README file for the U-Boot project.
118 File names etc. shall be based on the string "u-boot". Examples:
120 include/asm-ppc/u-boot.h
122 #include <asm/u-boot.h>
124 Variable names, preprocessor constants etc. shall be either based on
125 the string "u_boot" or on "U_BOOT". Example:
127 U_BOOT_VERSION u_boot_logo
128 IH_OS_U_BOOT u_boot_hush_start
134 Starting with the release in October 2008, the names of the releases
135 were changed from numerical release numbers without deeper meaning
136 into a time stamp based numbering. Regular releases are identified by
137 names consisting of the calendar year and month of the release date.
138 Additional fields (if present) indicate release candidates or bug fix
139 releases in "stable" maintenance trees.
142 U-Boot v2009.11 - Release November 2009
143 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
144 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
150 /arch Architecture specific files
151 /arm Files generic to ARM architecture
152 /cpu CPU specific files
153 /arm720t Files specific to ARM 720 CPUs
154 /arm920t Files specific to ARM 920 CPUs
155 /at91 Files specific to Atmel AT91RM9200 CPU
156 /imx Files specific to Freescale MC9328 i.MX CPUs
157 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
158 /arm925t Files specific to ARM 925 CPUs
159 /arm926ejs Files specific to ARM 926 CPUs
160 /arm1136 Files specific to ARM 1136 CPUs
161 /ixp Files specific to Intel XScale IXP CPUs
162 /pxa Files specific to Intel XScale PXA CPUs
163 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
164 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
165 /lib Architecture specific library files
166 /avr32 Files generic to AVR32 architecture
167 /cpu CPU specific files
168 /lib Architecture specific library files
169 /blackfin Files generic to Analog Devices Blackfin architecture
170 /cpu CPU specific files
171 /lib Architecture specific library files
172 /x86 Files generic to x86 architecture
173 /cpu CPU specific files
174 /lib Architecture specific library files
175 /m68k Files generic to m68k architecture
176 /cpu CPU specific files
177 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
178 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
179 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
180 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
181 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
182 /lib Architecture specific library files
183 /microblaze Files generic to microblaze architecture
184 /cpu CPU specific files
185 /lib Architecture specific library files
186 /mips Files generic to MIPS architecture
187 /cpu CPU specific files
188 /mips32 Files specific to MIPS32 CPUs
189 /xburst Files specific to Ingenic XBurst CPUs
190 /lib Architecture specific library files
191 /nds32 Files generic to NDS32 architecture
192 /cpu CPU specific files
193 /n1213 Files specific to Andes Technology N1213 CPUs
194 /lib Architecture specific library files
195 /nios2 Files generic to Altera NIOS2 architecture
196 /cpu CPU specific files
197 /lib Architecture specific library files
198 /powerpc Files generic to PowerPC architecture
199 /cpu CPU specific files
200 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
201 /mpc5xx Files specific to Freescale MPC5xx CPUs
202 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
203 /mpc8xx Files specific to Freescale MPC8xx CPUs
204 /mpc8220 Files specific to Freescale MPC8220 CPUs
205 /mpc824x Files specific to Freescale MPC824x CPUs
206 /mpc8260 Files specific to Freescale MPC8260 CPUs
207 /mpc85xx Files specific to Freescale MPC85xx CPUs
208 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
209 /lib Architecture specific library files
210 /sh Files generic to SH architecture
211 /cpu CPU specific files
212 /sh2 Files specific to sh2 CPUs
213 /sh3 Files specific to sh3 CPUs
214 /sh4 Files specific to sh4 CPUs
215 /lib Architecture specific library files
216 /sparc Files generic to SPARC architecture
217 /cpu CPU specific files
218 /leon2 Files specific to Gaisler LEON2 SPARC CPU
219 /leon3 Files specific to Gaisler LEON3 SPARC CPU
220 /lib Architecture specific library files
221 /api Machine/arch independent API for external apps
222 /board Board dependent files
223 /common Misc architecture independent functions
224 /disk Code for disk drive partition handling
225 /doc Documentation (don't expect too much)
226 /drivers Commonly used device drivers
227 /examples Example code for standalone applications, etc.
228 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
229 /include Header Files
230 /lib Files generic to all architectures
231 /libfdt Library files to support flattened device trees
232 /lzma Library files to support LZMA decompression
233 /lzo Library files to support LZO decompression
235 /post Power On Self Test
236 /rtc Real Time Clock drivers
237 /tools Tools to build S-Record or U-Boot images, etc.
239 Software Configuration:
240 =======================
242 Configuration is usually done using C preprocessor defines; the
243 rationale behind that is to avoid dead code whenever possible.
245 There are two classes of configuration variables:
247 * Configuration _OPTIONS_:
248 These are selectable by the user and have names beginning with
251 * Configuration _SETTINGS_:
252 These depend on the hardware etc. and should not be meddled with if
253 you don't know what you're doing; they have names beginning with
256 Later we will add a configuration tool - probably similar to or even
257 identical to what's used for the Linux kernel. Right now, we have to
258 do the configuration by hand, which means creating some symbolic
259 links and editing some configuration files. We use the TQM8xxL boards
263 Selection of Processor Architecture and Board Type:
264 ---------------------------------------------------
266 For all supported boards there are ready-to-use default
267 configurations available; just type "make <board_name>_config".
269 Example: For a TQM823L module type:
274 For the Cogent platform, you need to specify the CPU type as well;
275 e.g. "make cogent_mpc8xx_config". And also configure the cogent
276 directory according to the instructions in cogent/README.
279 Configuration Options:
280 ----------------------
282 Configuration depends on the combination of board and CPU type; all
283 such information is kept in a configuration file
284 "include/configs/<board_name>.h".
286 Example: For a TQM823L module, all configuration settings are in
287 "include/configs/TQM823L.h".
290 Many of the options are named exactly as the corresponding Linux
291 kernel configuration options. The intention is to make it easier to
292 build a config tool - later.
295 The following options need to be configured:
297 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
299 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
301 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
302 Define exactly one, e.g. CONFIG_ATSTK1002
304 - CPU Module Type: (if CONFIG_COGENT is defined)
305 Define exactly one of
307 --- FIXME --- not tested yet:
308 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
309 CONFIG_CMA287_23, CONFIG_CMA287_50
311 - Motherboard Type: (if CONFIG_COGENT is defined)
312 Define exactly one of
313 CONFIG_CMA101, CONFIG_CMA102
315 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
316 Define one or more of
319 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
320 Define one or more of
321 CONFIG_LCD_HEARTBEAT - update a character position on
322 the LCD display every second with
325 - Board flavour: (if CONFIG_MPC8260ADS is defined)
328 CONFIG_SYS_8260ADS - original MPC8260ADS
329 CONFIG_SYS_8266ADS - MPC8266ADS
330 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
331 CONFIG_SYS_8272ADS - MPC8272ADS
333 - Marvell Family Member
334 CONFIG_SYS_MVFS - define it if you want to enable
335 multiple fs option at one time
336 for marvell soc family
338 - MPC824X Family Member (if CONFIG_MPC824X is defined)
339 Define exactly one of
340 CONFIG_MPC8240, CONFIG_MPC8245
342 - 8xx CPU Options: (if using an MPC8xx CPU)
343 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
344 get_gclk_freq() cannot work
345 e.g. if there is no 32KHz
346 reference PIT/RTC clock
347 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
350 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
351 CONFIG_SYS_8xx_CPUCLK_MIN
352 CONFIG_SYS_8xx_CPUCLK_MAX
353 CONFIG_8xx_CPUCLK_DEFAULT
354 See doc/README.MPC866
356 CONFIG_SYS_MEASURE_CPUCLK
358 Define this to measure the actual CPU clock instead
359 of relying on the correctness of the configured
360 values. Mostly useful for board bringup to make sure
361 the PLL is locked at the intended frequency. Note
362 that this requires a (stable) reference clock (32 kHz
363 RTC clock or CONFIG_SYS_8XX_XIN)
365 CONFIG_SYS_DELAYED_ICACHE
367 Define this option if you want to enable the
368 ICache only when Code runs from RAM.
373 Specifies that the core is a 64-bit PowerPC implementation (implements
374 the "64" category of the Power ISA). This is necessary for ePAPR
375 compliance, among other possible reasons.
377 CONFIG_SYS_FSL_TBCLK_DIV
379 Defines the core time base clock divider ratio compared to the
380 system clock. On most PQ3 devices this is 8, on newer QorIQ
381 devices it can be 16 or 32. The ratio varies from SoC to Soc.
383 CONFIG_SYS_FSL_PCIE_COMPAT
385 Defines the string to utilize when trying to match PCIe device
386 tree nodes for the given platform.
388 CONFIG_SYS_PPC_E500_DEBUG_TLB
390 Enables a temporary TLB entry to be used during boot to work
391 around limitations in e500v1 and e500v2 external debugger
392 support. This reduces the portions of the boot code where
393 breakpoints and single stepping do not work. The value of this
394 symbol should be set to the TLB1 entry to be used for this
397 CONFIG_SYS_FSL_ERRATUM_A004510
399 Enables a workaround for erratum A004510. If set,
400 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
401 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
404 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
406 Defines one or two SoC revisions (low 8 bits of SVR)
407 for which the A004510 workaround should be applied.
409 The rest of SVR is either not relevant to the decision
410 of whether the erratum is present (e.g. p2040 versus
411 p2041) or is implied by the build target, which controls
412 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
414 See Freescale App Note 4493 for more information about
417 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
419 This is the value to write into CCSR offset 0x18600
420 according to the A004510 workaround.
422 - Generic CPU options:
423 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
425 Defines the endianess of the CPU. Implementation of those
426 values is arch specific.
428 - Intel Monahans options:
429 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
431 Defines the Monahans run mode to oscillator
432 ratio. Valid values are 8, 16, 24, 31. The core
433 frequency is this value multiplied by 13 MHz.
435 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
437 Defines the Monahans turbo mode to oscillator
438 ratio. Valid values are 1 (default if undefined) and
439 2. The core frequency as calculated above is multiplied
443 CONFIG_SYS_INIT_SP_OFFSET
445 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
446 pointer. This is needed for the temporary stack before
449 CONFIG_SYS_MIPS_CACHE_MODE
451 Cache operation mode for the MIPS CPU.
452 See also arch/mips/include/asm/mipsregs.h.
454 CONF_CM_CACHABLE_NO_WA
457 CONF_CM_CACHABLE_NONCOHERENT
461 CONF_CM_CACHABLE_ACCELERATED
463 CONFIG_SYS_XWAY_EBU_BOOTCFG
465 Special option for Lantiq XWAY SoCs for booting from NOR flash.
466 See also arch/mips/cpu/mips32/start.S.
468 CONFIG_XWAY_SWAP_BYTES
470 Enable compilation of tools/xway-swap-bytes needed for Lantiq
471 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
472 be swapped if a flash programmer is used.
475 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
477 Select high exception vectors of the ARM core, e.g., do not
478 clear the V bit of the c1 register of CP15.
480 CONFIG_SYS_THUMB_BUILD
482 Use this flag to build U-Boot using the Thumb instruction
483 set for ARM architectures. Thumb instruction set provides
484 better code density. For ARM architectures that support
485 Thumb2 this flag will result in Thumb2 code generated by
488 CONFIG_ARM_ERRATA_716044
489 CONFIG_ARM_ERRATA_742230
490 CONFIG_ARM_ERRATA_743622
491 CONFIG_ARM_ERRATA_751472
493 If set, the workarounds for these ARM errata are applied early
494 during U-Boot startup. Note that these options force the
495 workarounds to be applied; no CPU-type/version detection
496 exists, unlike the similar options in the Linux kernel. Do not
497 set these options unless they apply!
502 The frequency of the timer returned by get_timer().
503 get_timer() must operate in milliseconds and this CONFIG
504 option must be set to 1000.
506 - Linux Kernel Interface:
509 U-Boot stores all clock information in Hz
510 internally. For binary compatibility with older Linux
511 kernels (which expect the clocks passed in the
512 bd_info data to be in MHz) the environment variable
513 "clocks_in_mhz" can be defined so that U-Boot
514 converts clock data to MHZ before passing it to the
516 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
517 "clocks_in_mhz=1" is automatically included in the
520 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
522 When transferring memsize parameter to linux, some versions
523 expect it to be in bytes, others in MB.
524 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
528 New kernel versions are expecting firmware settings to be
529 passed using flattened device trees (based on open firmware
533 * New libfdt-based support
534 * Adds the "fdt" command
535 * The bootm command automatically updates the fdt
537 OF_CPU - The proper name of the cpus node (only required for
538 MPC512X and MPC5xxx based boards).
539 OF_SOC - The proper name of the soc node (only required for
540 MPC512X and MPC5xxx based boards).
541 OF_TBCLK - The timebase frequency.
542 OF_STDOUT_PATH - The path to the console device
544 boards with QUICC Engines require OF_QE to set UCC MAC
547 CONFIG_OF_BOARD_SETUP
549 Board code has addition modification that it wants to make
550 to the flat device tree before handing it off to the kernel
554 This define fills in the correct boot CPU in the boot
555 param header, the default value is zero if undefined.
559 U-Boot can detect if an IDE device is present or not.
560 If not, and this new config option is activated, U-Boot
561 removes the ATA node from the DTS before booting Linux,
562 so the Linux IDE driver does not probe the device and
563 crash. This is needed for buggy hardware (uc101) where
564 no pull down resistor is connected to the signal IDE5V_DD7.
566 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
568 This setting is mandatory for all boards that have only one
569 machine type and must be used to specify the machine type
570 number as it appears in the ARM machine registry
571 (see http://www.arm.linux.org.uk/developer/machines/).
572 Only boards that have multiple machine types supported
573 in a single configuration file and the machine type is
574 runtime discoverable, do not have to use this setting.
576 - vxWorks boot parameters:
578 bootvx constructs a valid bootline using the following
579 environments variables: bootfile, ipaddr, serverip, hostname.
580 It loads the vxWorks image pointed bootfile.
582 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
583 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
584 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
585 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
587 CONFIG_SYS_VXWORKS_ADD_PARAMS
589 Add it at the end of the bootline. E.g "u=username pw=secret"
591 Note: If a "bootargs" environment is defined, it will overwride
592 the defaults discussed just above.
594 - Cache Configuration:
595 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
596 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
597 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
599 - Cache Configuration for ARM:
600 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
602 CONFIG_SYS_PL310_BASE - Physical base address of PL310
603 controller register space
608 Define this if you want support for Amba PrimeCell PL010 UARTs.
612 Define this if you want support for Amba PrimeCell PL011 UARTs.
616 If you have Amba PrimeCell PL011 UARTs, set this variable to
617 the clock speed of the UARTs.
621 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
622 define this to a list of base addresses for each (supported)
623 port. See e.g. include/configs/versatile.h
625 CONFIG_PL011_SERIAL_RLCR
627 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
628 have separate receive and transmit line control registers. Set
629 this variable to initialize the extra register.
631 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
633 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
634 boot loader that has already initialized the UART. Define this
635 variable to flush the UART at init time.
639 Depending on board, define exactly one serial port
640 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
641 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
642 console by defining CONFIG_8xx_CONS_NONE
644 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
645 port routines must be defined elsewhere
646 (i.e. serial_init(), serial_getc(), ...)
649 Enables console device for a color framebuffer. Needs following
650 defines (cf. smiLynxEM, i8042)
651 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
653 VIDEO_HW_RECTFILL graphic chip supports
656 VIDEO_HW_BITBLT graphic chip supports
657 bit-blit (cf. smiLynxEM)
658 VIDEO_VISIBLE_COLS visible pixel columns
660 VIDEO_VISIBLE_ROWS visible pixel rows
661 VIDEO_PIXEL_SIZE bytes per pixel
662 VIDEO_DATA_FORMAT graphic data format
663 (0-5, cf. cfb_console.c)
664 VIDEO_FB_ADRS framebuffer address
665 VIDEO_KBD_INIT_FCT keyboard int fct
666 (i.e. i8042_kbd_init())
667 VIDEO_TSTC_FCT test char fct
669 VIDEO_GETC_FCT get char fct
671 CONFIG_CONSOLE_CURSOR cursor drawing on/off
672 (requires blink timer
674 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
675 CONFIG_CONSOLE_TIME display time/date info in
677 (requires CONFIG_CMD_DATE)
678 CONFIG_VIDEO_LOGO display Linux logo in
680 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
681 linux_logo.h for logo.
682 Requires CONFIG_VIDEO_LOGO
683 CONFIG_CONSOLE_EXTRA_INFO
684 additional board info beside
687 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
688 a limited number of ANSI escape sequences (cursor control,
689 erase functions and limited graphics rendition control).
691 When CONFIG_CFB_CONSOLE is defined, video console is
692 default i/o. Serial console can be forced with
693 environment 'console=serial'.
695 When CONFIG_SILENT_CONSOLE is defined, all console
696 messages (by U-Boot and Linux!) can be silenced with
697 the "silent" environment variable. See
698 doc/README.silent for more information.
701 CONFIG_BAUDRATE - in bps
702 Select one of the baudrates listed in
703 CONFIG_SYS_BAUDRATE_TABLE, see below.
704 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
706 - Console Rx buffer length
707 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
708 the maximum receive buffer length for the SMC.
709 This option is actual only for 82xx and 8xx possible.
710 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
711 must be defined, to setup the maximum idle timeout for
714 - Pre-Console Buffer:
715 Prior to the console being initialised (i.e. serial UART
716 initialised etc) all console output is silently discarded.
717 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
718 buffer any console messages prior to the console being
719 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
720 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
721 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
722 bytes are output before the console is initialised, the
723 earlier bytes are discarded.
725 'Sane' compilers will generate smaller code if
726 CONFIG_PRE_CON_BUF_SZ is a power of 2
728 - Safe printf() functions
729 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
730 the printf() functions. These are defined in
731 include/vsprintf.h and include snprintf(), vsnprintf() and
732 so on. Code size increase is approximately 300-500 bytes.
733 If this option is not given then these functions will
734 silently discard their buffer size argument - this means
735 you are not getting any overflow checking in this case.
737 - Boot Delay: CONFIG_BOOTDELAY - in seconds
738 Delay before automatically booting the default image;
739 set to -1 to disable autoboot.
740 set to -2 to autoboot with no delay and not check for abort
741 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
743 See doc/README.autoboot for these options that
744 work with CONFIG_BOOTDELAY. None are required.
745 CONFIG_BOOT_RETRY_TIME
746 CONFIG_BOOT_RETRY_MIN
747 CONFIG_AUTOBOOT_KEYED
748 CONFIG_AUTOBOOT_PROMPT
749 CONFIG_AUTOBOOT_DELAY_STR
750 CONFIG_AUTOBOOT_STOP_STR
751 CONFIG_AUTOBOOT_DELAY_STR2
752 CONFIG_AUTOBOOT_STOP_STR2
753 CONFIG_ZERO_BOOTDELAY_CHECK
754 CONFIG_RESET_TO_RETRY
758 Only needed when CONFIG_BOOTDELAY is enabled;
759 define a command string that is automatically executed
760 when no character is read on the console interface
761 within "Boot Delay" after reset.
764 This can be used to pass arguments to the bootm
765 command. The value of CONFIG_BOOTARGS goes into the
766 environment value "bootargs".
768 CONFIG_RAMBOOT and CONFIG_NFSBOOT
769 The value of these goes into the environment as
770 "ramboot" and "nfsboot" respectively, and can be used
771 as a convenience, when switching between booting from
777 When this option is #defined, the existence of the
778 environment variable "preboot" will be checked
779 immediately before starting the CONFIG_BOOTDELAY
780 countdown and/or running the auto-boot command resp.
781 entering interactive mode.
783 This feature is especially useful when "preboot" is
784 automatically generated or modified. For an example
785 see the LWMON board specific code: here "preboot" is
786 modified when the user holds down a certain
787 combination of keys on the (special) keyboard when
790 - Serial Download Echo Mode:
792 If defined to 1, all characters received during a
793 serial download (using the "loads" command) are
794 echoed back. This might be needed by some terminal
795 emulations (like "cu"), but may as well just take
796 time on others. This setting #define's the initial
797 value of the "loads_echo" environment variable.
799 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
801 Select one of the baudrates listed in
802 CONFIG_SYS_BAUDRATE_TABLE, see below.
805 Monitor commands can be included or excluded
806 from the build by using the #include files
807 <config_cmd_all.h> and #undef'ing unwanted
808 commands, or using <config_cmd_default.h>
809 and augmenting with additional #define's
812 The default command configuration includes all commands
813 except those marked below with a "*".
815 CONFIG_CMD_ASKENV * ask for env variable
816 CONFIG_CMD_BDI bdinfo
817 CONFIG_CMD_BEDBUG * Include BedBug Debugger
818 CONFIG_CMD_BMP * BMP support
819 CONFIG_CMD_BSP * Board specific commands
820 CONFIG_CMD_BOOTD bootd
821 CONFIG_CMD_CACHE * icache, dcache
822 CONFIG_CMD_CONSOLE coninfo
823 CONFIG_CMD_CRC32 * crc32
824 CONFIG_CMD_DATE * support for RTC, date/time...
825 CONFIG_CMD_DHCP * DHCP support
826 CONFIG_CMD_DIAG * Diagnostics
827 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
828 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
829 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
830 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
831 CONFIG_CMD_DTT * Digital Therm and Thermostat
832 CONFIG_CMD_ECHO echo arguments
833 CONFIG_CMD_EDITENV edit env variable
834 CONFIG_CMD_EEPROM * EEPROM read/write support
835 CONFIG_CMD_ELF * bootelf, bootvx
836 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
837 CONFIG_CMD_ENV_FLAGS * display details about env flags
838 CONFIG_CMD_EXPORTENV * export the environment
839 CONFIG_CMD_EXT2 * ext2 command support
840 CONFIG_CMD_EXT4 * ext4 command support
841 CONFIG_CMD_SAVEENV saveenv
842 CONFIG_CMD_FDC * Floppy Disk Support
843 CONFIG_CMD_FAT * FAT command support
844 CONFIG_CMD_FDOS * Dos diskette Support
845 CONFIG_CMD_FLASH flinfo, erase, protect
846 CONFIG_CMD_FPGA FPGA device initialization 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_SOURCE "source" command Support
902 CONFIG_CMD_SPI * SPI serial bus support
903 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
904 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
905 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
906 CONFIG_CMD_TIMER * access to the system tick timer
907 CONFIG_CMD_USB * USB support
908 CONFIG_CMD_CDP * Cisco Discover Protocol support
909 CONFIG_CMD_MFSL * Microblaze FSL support
912 EXAMPLE: If you want all functions except of network
913 support you can write:
915 #include "config_cmd_all.h"
916 #undef CONFIG_CMD_NET
919 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
921 Note: Don't enable the "icache" and "dcache" commands
922 (configuration option CONFIG_CMD_CACHE) unless you know
923 what you (and your U-Boot users) are doing. Data
924 cache cannot be enabled on systems like the 8xx or
925 8260 (where accesses to the IMMR region must be
926 uncached), and it cannot be disabled on all other
927 systems where we (mis-) use the data cache to hold an
928 initial stack and some data.
931 XXX - this list needs to get updated!
935 If this variable is defined, U-Boot will use a device tree
936 to configure its devices, instead of relying on statically
937 compiled #defines in the board file. This option is
938 experimental and only available on a few boards. The device
939 tree is available in the global data as gd->fdt_blob.
941 U-Boot needs to get its device tree from somewhere. This can
942 be done using one of the two options below:
945 If this variable is defined, U-Boot will embed a device tree
946 binary in its image. This device tree file should be in the
947 board directory and called <soc>-<board>.dts. The binary file
948 is then picked up in board_init_f() and made available through
949 the global data structure as gd->blob.
952 If this variable is defined, U-Boot will build a device tree
953 binary. It will be called u-boot.dtb. Architecture-specific
954 code will locate it at run-time. Generally this works by:
956 cat u-boot.bin u-boot.dtb >image.bin
958 and in fact, U-Boot does this for you, creating a file called
959 u-boot-dtb.bin which is useful in the common case. You can
960 still use the individual files if you need something more
965 If this variable is defined, it enables watchdog
966 support for the SoC. There must be support in the SoC
967 specific code for a watchdog. For the 8xx and 8260
968 CPUs, the SIU Watchdog feature is enabled in the SYPCR
969 register. When supported for a specific SoC is
970 available, then no further board specific code should
974 When using a watchdog circuitry external to the used
975 SoC, then define this variable and provide board
976 specific code for the "hw_watchdog_reset" function.
979 CONFIG_VERSION_VARIABLE
980 If this variable is defined, an environment variable
981 named "ver" is created by U-Boot showing the U-Boot
982 version as printed by the "version" command.
983 Any change to this variable will be reverted at the
988 When CONFIG_CMD_DATE is selected, the type of the RTC
989 has to be selected, too. Define exactly one of the
992 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
993 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
994 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
995 CONFIG_RTC_MC146818 - use MC146818 RTC
996 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
997 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
998 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
999 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1000 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1001 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1002 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1003 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1006 Note that if the RTC uses I2C, then the I2C interface
1007 must also be configured. See I2C Support, below.
1010 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1011 CONFIG_PCA953X_INFO - enable pca953x info command
1013 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1014 chip-ngpio pairs that tell the PCA953X driver the number of
1015 pins supported by a particular chip.
1017 Note that if the GPIO device uses I2C, then the I2C interface
1018 must also be configured. See I2C Support, below.
1020 - Timestamp Support:
1022 When CONFIG_TIMESTAMP is selected, the timestamp
1023 (date and time) of an image is printed by image
1024 commands like bootm or iminfo. This option is
1025 automatically enabled when you select CONFIG_CMD_DATE .
1027 - Partition Labels (disklabels) Supported:
1028 Zero or more of the following:
1029 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1030 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1031 Intel architecture, USB sticks, etc.
1032 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1033 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1034 bootloader. Note 2TB partition limit; see
1036 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1038 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1039 CONFIG_CMD_SCSI) you must configure support for at
1040 least one non-MTD partition type as well.
1043 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1044 board configurations files but used nowhere!
1046 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1047 be performed by calling the function
1048 ide_set_reset(int reset)
1049 which has to be defined in a board specific file
1054 Set this to enable ATAPI support.
1059 Set this to enable support for disks larger than 137GB
1060 Also look at CONFIG_SYS_64BIT_LBA.
1061 Whithout these , LBA48 support uses 32bit variables and will 'only'
1062 support disks up to 2.1TB.
1064 CONFIG_SYS_64BIT_LBA:
1065 When enabled, makes the IDE subsystem use 64bit sector addresses.
1069 At the moment only there is only support for the
1070 SYM53C8XX SCSI controller; define
1071 CONFIG_SCSI_SYM53C8XX to enable it.
1073 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1074 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1075 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1076 maximum numbers of LUNs, SCSI ID's and target
1078 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1080 The environment variable 'scsidevs' is set to the number of
1081 SCSI devices found during the last scan.
1083 - NETWORK Support (PCI):
1085 Support for Intel 8254x/8257x gigabit chips.
1088 Utility code for direct access to the SPI bus on Intel 8257x.
1089 This does not do anything useful unless you set at least one
1090 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1092 CONFIG_E1000_SPI_GENERIC
1093 Allow generic access to the SPI bus on the Intel 8257x, for
1094 example with the "sspi" command.
1097 Management command for E1000 devices. When used on devices
1098 with SPI support you can reprogram the EEPROM from U-Boot.
1100 CONFIG_E1000_FALLBACK_MAC
1101 default MAC for empty EEPROM after production.
1104 Support for Intel 82557/82559/82559ER chips.
1105 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1106 write routine for first time initialisation.
1109 Support for Digital 2114x chips.
1110 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1111 modem chip initialisation (KS8761/QS6611).
1114 Support for National dp83815 chips.
1117 Support for National dp8382[01] gigabit chips.
1119 - NETWORK Support (other):
1121 CONFIG_DRIVER_AT91EMAC
1122 Support for AT91RM9200 EMAC.
1125 Define this to use reduced MII inteface
1127 CONFIG_DRIVER_AT91EMAC_QUIET
1128 If this defined, the driver is quiet.
1129 The driver doen't show link status messages.
1131 CONFIG_CALXEDA_XGMAC
1132 Support for the Calxeda XGMAC device
1135 Support for SMSC's LAN91C96 chips.
1137 CONFIG_LAN91C96_BASE
1138 Define this to hold the physical address
1139 of the LAN91C96's I/O space
1141 CONFIG_LAN91C96_USE_32_BIT
1142 Define this to enable 32 bit addressing
1145 Support for SMSC's LAN91C111 chip
1147 CONFIG_SMC91111_BASE
1148 Define this to hold the physical address
1149 of the device (I/O space)
1151 CONFIG_SMC_USE_32_BIT
1152 Define this if data bus is 32 bits
1154 CONFIG_SMC_USE_IOFUNCS
1155 Define this to use i/o functions instead of macros
1156 (some hardware wont work with macros)
1158 CONFIG_DRIVER_TI_EMAC
1159 Support for davinci emac
1161 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1162 Define this if you have more then 3 PHYs.
1165 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1167 CONFIG_FTGMAC100_EGIGA
1168 Define this to use GE link update with gigabit PHY.
1169 Define this if FTGMAC100 is connected to gigabit PHY.
1170 If your system has 10/100 PHY only, it might not occur
1171 wrong behavior. Because PHY usually return timeout or
1172 useless data when polling gigabit status and gigabit
1173 control registers. This behavior won't affect the
1174 correctnessof 10/100 link speed update.
1177 Support for SMSC's LAN911x and LAN921x chips
1180 Define this to hold the physical address
1181 of the device (I/O space)
1183 CONFIG_SMC911X_32_BIT
1184 Define this if data bus is 32 bits
1186 CONFIG_SMC911X_16_BIT
1187 Define this if data bus is 16 bits. If your processor
1188 automatically converts one 32 bit word to two 16 bit
1189 words you may also try CONFIG_SMC911X_32_BIT.
1192 Support for Renesas on-chip Ethernet controller
1194 CONFIG_SH_ETHER_USE_PORT
1195 Define the number of ports to be used
1197 CONFIG_SH_ETHER_PHY_ADDR
1198 Define the ETH PHY's address
1200 CONFIG_SH_ETHER_CACHE_WRITEBACK
1201 If this option is set, the driver enables cache flush.
1204 CONFIG_GENERIC_LPC_TPM
1205 Support for generic parallel port TPM devices. Only one device
1206 per system is supported at this time.
1208 CONFIG_TPM_TIS_BASE_ADDRESS
1209 Base address where the generic TPM device is mapped
1210 to. Contemporary x86 systems usually map it at
1214 At the moment only the UHCI host controller is
1215 supported (PIP405, MIP405, MPC5200); define
1216 CONFIG_USB_UHCI to enable it.
1217 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1218 and define CONFIG_USB_STORAGE to enable the USB
1221 Supported are USB Keyboards and USB Floppy drives
1223 MPC5200 USB requires additional defines:
1225 for 528 MHz Clock: 0x0001bbbb
1229 for differential drivers: 0x00001000
1230 for single ended drivers: 0x00005000
1231 for differential drivers on PSC3: 0x00000100
1232 for single ended drivers on PSC3: 0x00004100
1233 CONFIG_SYS_USB_EVENT_POLL
1234 May be defined to allow interrupt polling
1235 instead of using asynchronous interrupts
1237 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1238 txfilltuning field in the EHCI controller on reset.
1241 Define the below if you wish to use the USB console.
1242 Once firmware is rebuilt from a serial console issue the
1243 command "setenv stdin usbtty; setenv stdout usbtty" and
1244 attach your USB cable. The Unix command "dmesg" should print
1245 it has found a new device. The environment variable usbtty
1246 can be set to gserial or cdc_acm to enable your device to
1247 appear to a USB host as a Linux gserial device or a
1248 Common Device Class Abstract Control Model serial device.
1249 If you select usbtty = gserial you should be able to enumerate
1251 # modprobe usbserial vendor=0xVendorID product=0xProductID
1252 else if using cdc_acm, simply setting the environment
1253 variable usbtty to be cdc_acm should suffice. The following
1254 might be defined in YourBoardName.h
1257 Define this to build a UDC device
1260 Define this to have a tty type of device available to
1261 talk to the UDC device
1264 Define this to enable the high speed support for usb
1265 device and usbtty. If this feature is enabled, a routine
1266 int is_usbd_high_speed(void)
1267 also needs to be defined by the driver to dynamically poll
1268 whether the enumeration has succeded at high speed or full
1271 CONFIG_SYS_CONSOLE_IS_IN_ENV
1272 Define this if you want stdin, stdout &/or stderr to
1276 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1277 Derive USB clock from external clock "blah"
1278 - CONFIG_SYS_USB_EXTC_CLK 0x02
1280 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1281 Derive USB clock from brgclk
1282 - CONFIG_SYS_USB_BRG_CLK 0x04
1284 If you have a USB-IF assigned VendorID then you may wish to
1285 define your own vendor specific values either in BoardName.h
1286 or directly in usbd_vendor_info.h. If you don't define
1287 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1288 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1289 should pretend to be a Linux device to it's target host.
1291 CONFIG_USBD_MANUFACTURER
1292 Define this string as the name of your company for
1293 - CONFIG_USBD_MANUFACTURER "my company"
1295 CONFIG_USBD_PRODUCT_NAME
1296 Define this string as the name of your product
1297 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1299 CONFIG_USBD_VENDORID
1300 Define this as your assigned Vendor ID from the USB
1301 Implementors Forum. This *must* be a genuine Vendor ID
1302 to avoid polluting the USB namespace.
1303 - CONFIG_USBD_VENDORID 0xFFFF
1305 CONFIG_USBD_PRODUCTID
1306 Define this as the unique Product ID
1308 - CONFIG_USBD_PRODUCTID 0xFFFF
1310 - ULPI Layer Support:
1311 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1312 the generic ULPI layer. The generic layer accesses the ULPI PHY
1313 via the platform viewport, so you need both the genric layer and
1314 the viewport enabled. Currently only Chipidea/ARC based
1315 viewport is supported.
1316 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1317 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1318 If your ULPI phy needs a different reference clock than the
1319 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1320 the appropriate value in Hz.
1323 The MMC controller on the Intel PXA is supported. To
1324 enable this define CONFIG_MMC. The MMC can be
1325 accessed from the boot prompt by mapping the device
1326 to physical memory similar to flash. Command line is
1327 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1328 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1331 Support for Renesas on-chip MMCIF controller
1333 CONFIG_SH_MMCIF_ADDR
1334 Define the base address of MMCIF registers
1337 Define the clock frequency for MMCIF
1339 - USB Device Firmware Update (DFU) class support:
1341 This enables the USB portion of the DFU USB class
1344 This enables the command "dfu" which is used to have
1345 U-Boot create a DFU class device via USB. This command
1346 requires that the "dfu_alt_info" environment variable be
1347 set and define the alt settings to expose to the host.
1350 This enables support for exposing (e)MMC devices via DFU.
1353 This enables support for exposing NAND devices via DFU.
1355 CONFIG_SYS_DFU_MAX_FILE_SIZE
1356 When updating files rather than the raw storage device,
1357 we use a static buffer to copy the file into and then write
1358 the buffer once we've been given the whole file. Define
1359 this to the maximum filesize (in bytes) for the buffer.
1360 Default is 4 MiB if undefined.
1362 - Journaling Flash filesystem support:
1363 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1364 CONFIG_JFFS2_NAND_DEV
1365 Define these for a default partition on a NAND device
1367 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1368 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1369 Define these for a default partition on a NOR device
1371 CONFIG_SYS_JFFS_CUSTOM_PART
1372 Define this to create an own partition. You have to provide a
1373 function struct part_info* jffs2_part_info(int part_num)
1375 If you define only one JFFS2 partition you may also want to
1376 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1377 to disable the command chpart. This is the default when you
1378 have not defined a custom partition
1380 - FAT(File Allocation Table) filesystem write function support:
1383 Define this to enable support for saving memory data as a
1384 file in FAT formatted partition.
1386 This will also enable the command "fatwrite" enabling the
1387 user to write files to FAT.
1389 CBFS (Coreboot Filesystem) support
1392 Define this to enable support for reading from a Coreboot
1393 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1399 Define this to enable standard (PC-Style) keyboard
1403 Standard PC keyboard driver with US (is default) and
1404 GERMAN key layout (switch via environment 'keymap=de') support.
1405 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1406 for cfb_console. Supports cursor blinking.
1411 Define this to enable video support (for output to
1414 CONFIG_VIDEO_CT69000
1416 Enable Chips & Technologies 69000 Video chip
1418 CONFIG_VIDEO_SMI_LYNXEM
1419 Enable Silicon Motion SMI 712/710/810 Video chip. The
1420 video output is selected via environment 'videoout'
1421 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1424 For the CT69000 and SMI_LYNXEM drivers, videomode is
1425 selected via environment 'videomode'. Two different ways
1427 - "videomode=num" 'num' is a standard LiLo mode numbers.
1428 Following standard modes are supported (* is default):
1430 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1431 -------------+---------------------------------------------
1432 8 bits | 0x301* 0x303 0x305 0x161 0x307
1433 15 bits | 0x310 0x313 0x316 0x162 0x319
1434 16 bits | 0x311 0x314 0x317 0x163 0x31A
1435 24 bits | 0x312 0x315 0x318 ? 0x31B
1436 -------------+---------------------------------------------
1437 (i.e. setenv videomode 317; saveenv; reset;)
1439 - "videomode=bootargs" all the video parameters are parsed
1440 from the bootargs. (See drivers/video/videomodes.c)
1443 CONFIG_VIDEO_SED13806
1444 Enable Epson SED13806 driver. This driver supports 8bpp
1445 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1446 or CONFIG_VIDEO_SED13806_16BPP
1449 Enable the Freescale DIU video driver. Reference boards for
1450 SOCs that have a DIU should define this macro to enable DIU
1451 support, and should also define these other macros:
1457 CONFIG_VIDEO_SW_CURSOR
1458 CONFIG_VGA_AS_SINGLE_DEVICE
1460 CONFIG_VIDEO_BMP_LOGO
1462 The DIU driver will look for the 'video-mode' environment
1463 variable, and if defined, enable the DIU as a console during
1464 boot. See the documentation file README.video for a
1465 description of this variable.
1469 Enable the VGA video / BIOS for x86. The alternative if you
1470 are using coreboot is to use the coreboot frame buffer
1477 Define this to enable a custom keyboard support.
1478 This simply calls drv_keyboard_init() which must be
1479 defined in your board-specific files.
1480 The only board using this so far is RBC823.
1482 - LCD Support: CONFIG_LCD
1484 Define this to enable LCD support (for output to LCD
1485 display); also select one of the supported displays
1486 by defining one of these:
1490 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1492 CONFIG_NEC_NL6448AC33:
1494 NEC NL6448AC33-18. Active, color, single scan.
1496 CONFIG_NEC_NL6448BC20
1498 NEC NL6448BC20-08. 6.5", 640x480.
1499 Active, color, single scan.
1501 CONFIG_NEC_NL6448BC33_54
1503 NEC NL6448BC33-54. 10.4", 640x480.
1504 Active, color, single scan.
1508 Sharp 320x240. Active, color, single scan.
1509 It isn't 16x9, and I am not sure what it is.
1511 CONFIG_SHARP_LQ64D341
1513 Sharp LQ64D341 display, 640x480.
1514 Active, color, single scan.
1518 HLD1045 display, 640x480.
1519 Active, color, single scan.
1523 Optrex CBL50840-2 NF-FW 99 22 M5
1525 Hitachi LMG6912RPFC-00T
1529 320x240. Black & white.
1531 Normally display is black on white background; define
1532 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1534 CONFIG_LCD_ALIGNMENT
1536 Normally the LCD is page-aligned (tyically 4KB). If this is
1537 defined then the LCD will be aligned to this value instead.
1538 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1539 here, since it is cheaper to change data cache settings on
1540 a per-section basis.
1542 CONFIG_CONSOLE_SCROLL_LINES
1544 When the console need to be scrolled, this is the number of
1545 lines to scroll by. It defaults to 1. Increasing this makes
1546 the console jump but can help speed up operation when scrolling
1551 Support drawing of RLE8-compressed bitmaps on the LCD.
1555 Enables an 'i2c edid' command which can read EDID
1556 information over I2C from an attached LCD display.
1558 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1560 If this option is set, the environment is checked for
1561 a variable "splashimage". If found, the usual display
1562 of logo, copyright and system information on the LCD
1563 is suppressed and the BMP image at the address
1564 specified in "splashimage" is loaded instead. The
1565 console is redirected to the "nulldev", too. This
1566 allows for a "silent" boot where a splash screen is
1567 loaded very quickly after power-on.
1569 CONFIG_SPLASHIMAGE_GUARD
1571 If this option is set, then U-Boot will prevent the environment
1572 variable "splashimage" from being set to a problematic address
1573 (see README.displaying-bmps and README.arm-unaligned-accesses).
1574 This option is useful for targets where, due to alignment
1575 restrictions, an improperly aligned BMP image will cause a data
1576 abort. If you think you will not have problems with unaligned
1577 accesses (for example because your toolchain prevents them)
1578 there is no need to set this option.
1580 CONFIG_SPLASH_SCREEN_ALIGN
1582 If this option is set the splash image can be freely positioned
1583 on the screen. Environment variable "splashpos" specifies the
1584 position as "x,y". If a positive number is given it is used as
1585 number of pixel from left/top. If a negative number is given it
1586 is used as number of pixel from right/bottom. You can also
1587 specify 'm' for centering the image.
1590 setenv splashpos m,m
1591 => image at center of screen
1593 setenv splashpos 30,20
1594 => image at x = 30 and y = 20
1596 setenv splashpos -10,m
1597 => vertically centered image
1598 at x = dspWidth - bmpWidth - 9
1600 CONFIG_SPLASH_SCREEN_PREPARE
1602 If this option is set then the board_splash_screen_prepare()
1603 function, which must be defined in your code, is called as part
1604 of the splash screen display sequence. It gives the board an
1605 opportunity to prepare the splash image data before it is
1606 processed and sent to the frame buffer by U-Boot.
1608 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1610 If this option is set, additionally to standard BMP
1611 images, gzipped BMP images can be displayed via the
1612 splashscreen support or the bmp command.
1614 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1616 If this option is set, 8-bit RLE compressed BMP images
1617 can be displayed via the splashscreen support or the
1620 - Do compresssing for memory range:
1623 If this option is set, it would use zlib deflate method
1624 to compress the specified memory at its best effort.
1626 - Compression support:
1629 If this option is set, support for bzip2 compressed
1630 images is included. If not, only uncompressed and gzip
1631 compressed images are supported.
1633 NOTE: the bzip2 algorithm requires a lot of RAM, so
1634 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1639 If this option is set, support for lzma compressed
1642 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1643 requires an amount of dynamic memory that is given by the
1646 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1648 Where lc and lp stand for, respectively, Literal context bits
1649 and Literal pos bits.
1651 This value is upper-bounded by 14MB in the worst case. Anyway,
1652 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1653 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1654 a very small buffer.
1656 Use the lzmainfo tool to determinate the lc and lp values and
1657 then calculate the amount of needed dynamic memory (ensuring
1658 the appropriate CONFIG_SYS_MALLOC_LEN value).
1663 The address of PHY on MII bus.
1665 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1667 The clock frequency of the MII bus
1671 If this option is set, support for speed/duplex
1672 detection of gigabit PHY is included.
1674 CONFIG_PHY_RESET_DELAY
1676 Some PHY like Intel LXT971A need extra delay after
1677 reset before any MII register access is possible.
1678 For such PHY, set this option to the usec delay
1679 required. (minimum 300usec for LXT971A)
1681 CONFIG_PHY_CMD_DELAY (ppc4xx)
1683 Some PHY like Intel LXT971A need extra delay after
1684 command issued before MII status register can be read
1694 Define a default value for Ethernet address to use
1695 for the respective Ethernet interface, in case this
1696 is not determined automatically.
1701 Define a default value for the IP address to use for
1702 the default Ethernet interface, in case this is not
1703 determined through e.g. bootp.
1704 (Environment variable "ipaddr")
1706 - Server IP address:
1709 Defines a default value for the IP address of a TFTP
1710 server to contact when using the "tftboot" command.
1711 (Environment variable "serverip")
1713 CONFIG_KEEP_SERVERADDR
1715 Keeps the server's MAC address, in the env 'serveraddr'
1716 for passing to bootargs (like Linux's netconsole option)
1718 - Gateway IP address:
1721 Defines a default value for the IP address of the
1722 default router where packets to other networks are
1724 (Environment variable "gatewayip")
1729 Defines a default value for the subnet mask (or
1730 routing prefix) which is used to determine if an IP
1731 address belongs to the local subnet or needs to be
1732 forwarded through a router.
1733 (Environment variable "netmask")
1735 - Multicast TFTP Mode:
1738 Defines whether you want to support multicast TFTP as per
1739 rfc-2090; for example to work with atftp. Lets lots of targets
1740 tftp down the same boot image concurrently. Note: the Ethernet
1741 driver in use must provide a function: mcast() to join/leave a
1744 - BOOTP Recovery Mode:
1745 CONFIG_BOOTP_RANDOM_DELAY
1747 If you have many targets in a network that try to
1748 boot using BOOTP, you may want to avoid that all
1749 systems send out BOOTP requests at precisely the same
1750 moment (which would happen for instance at recovery
1751 from a power failure, when all systems will try to
1752 boot, thus flooding the BOOTP server. Defining
1753 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1754 inserted before sending out BOOTP requests. The
1755 following delays are inserted then:
1757 1st BOOTP request: delay 0 ... 1 sec
1758 2nd BOOTP request: delay 0 ... 2 sec
1759 3rd BOOTP request: delay 0 ... 4 sec
1761 BOOTP requests: delay 0 ... 8 sec
1763 - DHCP Advanced Options:
1764 You can fine tune the DHCP functionality by defining
1765 CONFIG_BOOTP_* symbols:
1767 CONFIG_BOOTP_SUBNETMASK
1768 CONFIG_BOOTP_GATEWAY
1769 CONFIG_BOOTP_HOSTNAME
1770 CONFIG_BOOTP_NISDOMAIN
1771 CONFIG_BOOTP_BOOTPATH
1772 CONFIG_BOOTP_BOOTFILESIZE
1775 CONFIG_BOOTP_SEND_HOSTNAME
1776 CONFIG_BOOTP_NTPSERVER
1777 CONFIG_BOOTP_TIMEOFFSET
1778 CONFIG_BOOTP_VENDOREX
1779 CONFIG_BOOTP_MAY_FAIL
1781 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1782 environment variable, not the BOOTP server.
1784 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1785 after the configured retry count, the call will fail
1786 instead of starting over. This can be used to fail over
1787 to Link-local IP address configuration if the DHCP server
1790 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1791 serverip from a DHCP server, it is possible that more
1792 than one DNS serverip is offered to the client.
1793 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1794 serverip will be stored in the additional environment
1795 variable "dnsip2". The first DNS serverip is always
1796 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1799 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1800 to do a dynamic update of a DNS server. To do this, they
1801 need the hostname of the DHCP requester.
1802 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1803 of the "hostname" environment variable is passed as
1804 option 12 to the DHCP server.
1806 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1808 A 32bit value in microseconds for a delay between
1809 receiving a "DHCP Offer" and sending the "DHCP Request".
1810 This fixes a problem with certain DHCP servers that don't
1811 respond 100% of the time to a "DHCP request". E.g. On an
1812 AT91RM9200 processor running at 180MHz, this delay needed
1813 to be *at least* 15,000 usec before a Windows Server 2003
1814 DHCP server would reply 100% of the time. I recommend at
1815 least 50,000 usec to be safe. The alternative is to hope
1816 that one of the retries will be successful but note that
1817 the DHCP timeout and retry process takes a longer than
1820 - Link-local IP address negotiation:
1821 Negotiate with other link-local clients on the local network
1822 for an address that doesn't require explicit configuration.
1823 This is especially useful if a DHCP server cannot be guaranteed
1824 to exist in all environments that the device must operate.
1826 See doc/README.link-local for more information.
1829 CONFIG_CDP_DEVICE_ID
1831 The device id used in CDP trigger frames.
1833 CONFIG_CDP_DEVICE_ID_PREFIX
1835 A two character string which is prefixed to the MAC address
1840 A printf format string which contains the ascii name of
1841 the port. Normally is set to "eth%d" which sets
1842 eth0 for the first Ethernet, eth1 for the second etc.
1844 CONFIG_CDP_CAPABILITIES
1846 A 32bit integer which indicates the device capabilities;
1847 0x00000010 for a normal host which does not forwards.
1851 An ascii string containing the version of the software.
1855 An ascii string containing the name of the platform.
1859 A 32bit integer sent on the trigger.
1861 CONFIG_CDP_POWER_CONSUMPTION
1863 A 16bit integer containing the power consumption of the
1864 device in .1 of milliwatts.
1866 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1868 A byte containing the id of the VLAN.
1870 - Status LED: CONFIG_STATUS_LED
1872 Several configurations allow to display the current
1873 status using a LED. For instance, the LED will blink
1874 fast while running U-Boot code, stop blinking as
1875 soon as a reply to a BOOTP request was received, and
1876 start blinking slow once the Linux kernel is running
1877 (supported by a status LED driver in the Linux
1878 kernel). Defining CONFIG_STATUS_LED enables this
1881 - CAN Support: CONFIG_CAN_DRIVER
1883 Defining CONFIG_CAN_DRIVER enables CAN driver support
1884 on those systems that support this (optional)
1885 feature, like the TQM8xxL modules.
1887 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1889 These enable I2C serial bus commands. Defining either of
1890 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1891 include the appropriate I2C driver for the selected CPU.
1893 This will allow you to use i2c commands at the u-boot
1894 command line (as long as you set CONFIG_CMD_I2C in
1895 CONFIG_COMMANDS) and communicate with i2c based realtime
1896 clock chips. See common/cmd_i2c.c for a description of the
1897 command line interface.
1899 CONFIG_HARD_I2C selects a hardware I2C controller.
1901 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1902 bit-banging) driver instead of CPM or similar hardware
1905 There are several other quantities that must also be
1906 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1908 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1909 to be the frequency (in Hz) at which you wish your i2c bus
1910 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1911 the CPU's i2c node address).
1913 Now, the u-boot i2c code for the mpc8xx
1914 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1915 and so its address should therefore be cleared to 0 (See,
1916 eg, MPC823e User's Manual p.16-473). So, set
1917 CONFIG_SYS_I2C_SLAVE to 0.
1919 CONFIG_SYS_I2C_INIT_MPC5XXX
1921 When a board is reset during an i2c bus transfer
1922 chips might think that the current transfer is still
1923 in progress. Reset the slave devices by sending start
1924 commands until the slave device responds.
1926 That's all that's required for CONFIG_HARD_I2C.
1928 If you use the software i2c interface (CONFIG_SOFT_I2C)
1929 then the following macros need to be defined (examples are
1930 from include/configs/lwmon.h):
1934 (Optional). Any commands necessary to enable the I2C
1935 controller or configure ports.
1937 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1941 (Only for MPC8260 CPU). The I/O port to use (the code
1942 assumes both bits are on the same port). Valid values
1943 are 0..3 for ports A..D.
1947 The code necessary to make the I2C data line active
1948 (driven). If the data line is open collector, this
1951 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1955 The code necessary to make the I2C data line tri-stated
1956 (inactive). If the data line is open collector, this
1959 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1963 Code that returns true if the I2C data line is high,
1966 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1970 If <bit> is true, sets the I2C data line high. If it
1971 is false, it clears it (low).
1973 eg: #define I2C_SDA(bit) \
1974 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1975 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1979 If <bit> is true, sets the I2C clock line high. If it
1980 is false, it clears it (low).
1982 eg: #define I2C_SCL(bit) \
1983 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1984 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1988 This delay is invoked four times per clock cycle so this
1989 controls the rate of data transfer. The data rate thus
1990 is 1 / (I2C_DELAY * 4). Often defined to be something
1993 #define I2C_DELAY udelay(2)
1995 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1997 If your arch supports the generic GPIO framework (asm/gpio.h),
1998 then you may alternatively define the two GPIOs that are to be
1999 used as SCL / SDA. Any of the previous I2C_xxx macros will
2000 have GPIO-based defaults assigned to them as appropriate.
2002 You should define these to the GPIO value as given directly to
2003 the generic GPIO functions.
2005 CONFIG_SYS_I2C_INIT_BOARD
2007 When a board is reset during an i2c bus transfer
2008 chips might think that the current transfer is still
2009 in progress. On some boards it is possible to access
2010 the i2c SCLK line directly, either by using the
2011 processor pin as a GPIO or by having a second pin
2012 connected to the bus. If this option is defined a
2013 custom i2c_init_board() routine in boards/xxx/board.c
2014 is run early in the boot sequence.
2016 CONFIG_SYS_I2C_BOARD_LATE_INIT
2018 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2019 defined a custom i2c_board_late_init() routine in
2020 boards/xxx/board.c is run AFTER the operations in i2c_init()
2021 is completed. This callpoint can be used to unreset i2c bus
2022 using CPU i2c controller register accesses for CPUs whose i2c
2023 controller provide such a method. It is called at the end of
2024 i2c_init() to allow i2c_init operations to setup the i2c bus
2025 controller on the CPU (e.g. setting bus speed & slave address).
2027 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2029 This option enables configuration of bi_iic_fast[] flags
2030 in u-boot bd_info structure based on u-boot environment
2031 variable "i2cfast". (see also i2cfast)
2033 CONFIG_I2C_MULTI_BUS
2035 This option allows the use of multiple I2C buses, each of which
2036 must have a controller. At any point in time, only one bus is
2037 active. To switch to a different bus, use the 'i2c dev' command.
2038 Note that bus numbering is zero-based.
2040 CONFIG_SYS_I2C_NOPROBES
2042 This option specifies a list of I2C devices that will be skipped
2043 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2044 is set, specify a list of bus-device pairs. Otherwise, specify
2045 a 1D array of device addresses
2048 #undef CONFIG_I2C_MULTI_BUS
2049 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2051 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2053 #define CONFIG_I2C_MULTI_BUS
2054 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2056 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2058 CONFIG_SYS_SPD_BUS_NUM
2060 If defined, then this indicates the I2C bus number for DDR SPD.
2061 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2063 CONFIG_SYS_RTC_BUS_NUM
2065 If defined, then this indicates the I2C bus number for the RTC.
2066 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2068 CONFIG_SYS_DTT_BUS_NUM
2070 If defined, then this indicates the I2C bus number for the DTT.
2071 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2073 CONFIG_SYS_I2C_DTT_ADDR:
2075 If defined, specifies the I2C address of the DTT device.
2076 If not defined, then U-Boot uses predefined value for
2077 specified DTT device.
2081 Define this option if you want to use Freescale's I2C driver in
2082 drivers/i2c/fsl_i2c.c.
2086 Define this option if you have I2C devices reached over 1 .. n
2087 I2C Muxes like the pca9544a. This option addes a new I2C
2088 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2089 new I2C Bus to the existing I2C Busses. If you select the
2090 new Bus with "i2c dev", u-bbot sends first the commandos for
2091 the muxes to activate this new "bus".
2093 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2097 Adding a new I2C Bus reached over 2 pca9544a muxes
2098 The First mux with address 70 and channel 6
2099 The Second mux with address 71 and channel 4
2101 => i2c bus pca9544a:70:6:pca9544a:71:4
2103 Use the "i2c bus" command without parameter, to get a list
2104 of I2C Busses with muxes:
2107 Busses reached over muxes:
2109 reached over Mux(es):
2112 reached over Mux(es):
2117 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2118 u-boot first sends the command to the mux@70 to enable
2119 channel 6, and then the command to the mux@71 to enable
2122 After that, you can use the "normal" i2c commands as
2123 usual to communicate with your I2C devices behind
2126 This option is actually implemented for the bitbanging
2127 algorithm in common/soft_i2c.c and for the Hardware I2C
2128 Bus on the MPC8260. But it should be not so difficult
2129 to add this option to other architectures.
2131 CONFIG_SOFT_I2C_READ_REPEATED_START
2133 defining this will force the i2c_read() function in
2134 the soft_i2c driver to perform an I2C repeated start
2135 between writing the address pointer and reading the
2136 data. If this define is omitted the default behaviour
2137 of doing a stop-start sequence will be used. Most I2C
2138 devices can use either method, but some require one or
2141 - SPI Support: CONFIG_SPI
2143 Enables SPI driver (so far only tested with
2144 SPI EEPROM, also an instance works with Crystal A/D and
2145 D/As on the SACSng board)
2149 Enables the driver for SPI controller on SuperH. Currently
2150 only SH7757 is supported.
2154 Enables extended (16-bit) SPI EEPROM addressing.
2155 (symmetrical to CONFIG_I2C_X)
2159 Enables a software (bit-bang) SPI driver rather than
2160 using hardware support. This is a general purpose
2161 driver that only requires three general I/O port pins
2162 (two outputs, one input) to function. If this is
2163 defined, the board configuration must define several
2164 SPI configuration items (port pins to use, etc). For
2165 an example, see include/configs/sacsng.h.
2169 Enables a hardware SPI driver for general-purpose reads
2170 and writes. As with CONFIG_SOFT_SPI, the board configuration
2171 must define a list of chip-select function pointers.
2172 Currently supported on some MPC8xxx processors. For an
2173 example, see include/configs/mpc8349emds.h.
2177 Enables the driver for the SPI controllers on i.MX and MXC
2178 SoCs. Currently i.MX31/35/51 are supported.
2180 - FPGA Support: CONFIG_FPGA
2182 Enables FPGA subsystem.
2184 CONFIG_FPGA_<vendor>
2186 Enables support for specific chip vendors.
2189 CONFIG_FPGA_<family>
2191 Enables support for FPGA family.
2192 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2196 Specify the number of FPGA devices to support.
2198 CONFIG_SYS_FPGA_PROG_FEEDBACK
2200 Enable printing of hash marks during FPGA configuration.
2202 CONFIG_SYS_FPGA_CHECK_BUSY
2204 Enable checks on FPGA configuration interface busy
2205 status by the configuration function. This option
2206 will require a board or device specific function to
2211 If defined, a function that provides delays in the FPGA
2212 configuration driver.
2214 CONFIG_SYS_FPGA_CHECK_CTRLC
2215 Allow Control-C to interrupt FPGA configuration
2217 CONFIG_SYS_FPGA_CHECK_ERROR
2219 Check for configuration errors during FPGA bitfile
2220 loading. For example, abort during Virtex II
2221 configuration if the INIT_B line goes low (which
2222 indicated a CRC error).
2224 CONFIG_SYS_FPGA_WAIT_INIT
2226 Maximum time to wait for the INIT_B line to deassert
2227 after PROB_B has been deasserted during a Virtex II
2228 FPGA configuration sequence. The default time is 500
2231 CONFIG_SYS_FPGA_WAIT_BUSY
2233 Maximum time to wait for BUSY to deassert during
2234 Virtex II FPGA configuration. The default is 5 ms.
2236 CONFIG_SYS_FPGA_WAIT_CONFIG
2238 Time to wait after FPGA configuration. The default is
2241 - Configuration Management:
2244 If defined, this string will be added to the U-Boot
2245 version information (U_BOOT_VERSION)
2247 - Vendor Parameter Protection:
2249 U-Boot considers the values of the environment
2250 variables "serial#" (Board Serial Number) and
2251 "ethaddr" (Ethernet Address) to be parameters that
2252 are set once by the board vendor / manufacturer, and
2253 protects these variables from casual modification by
2254 the user. Once set, these variables are read-only,
2255 and write or delete attempts are rejected. You can
2256 change this behaviour:
2258 If CONFIG_ENV_OVERWRITE is #defined in your config
2259 file, the write protection for vendor parameters is
2260 completely disabled. Anybody can change or delete
2263 Alternatively, if you #define _both_ CONFIG_ETHADDR
2264 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2265 Ethernet address is installed in the environment,
2266 which can be changed exactly ONCE by the user. [The
2267 serial# is unaffected by this, i. e. it remains
2270 The same can be accomplished in a more flexible way
2271 for any variable by configuring the type of access
2272 to allow for those variables in the ".flags" variable
2273 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2278 Define this variable to enable the reservation of
2279 "protected RAM", i. e. RAM which is not overwritten
2280 by U-Boot. Define CONFIG_PRAM to hold the number of
2281 kB you want to reserve for pRAM. You can overwrite
2282 this default value by defining an environment
2283 variable "pram" to the number of kB you want to
2284 reserve. Note that the board info structure will
2285 still show the full amount of RAM. If pRAM is
2286 reserved, a new environment variable "mem" will
2287 automatically be defined to hold the amount of
2288 remaining RAM in a form that can be passed as boot
2289 argument to Linux, for instance like that:
2291 setenv bootargs ... mem=\${mem}
2294 This way you can tell Linux not to use this memory,
2295 either, which results in a memory region that will
2296 not be affected by reboots.
2298 *WARNING* If your board configuration uses automatic
2299 detection of the RAM size, you must make sure that
2300 this memory test is non-destructive. So far, the
2301 following board configurations are known to be
2304 IVMS8, IVML24, SPD8xx, TQM8xxL,
2305 HERMES, IP860, RPXlite, LWMON,
2308 - Access to physical memory region (> 4GB)
2309 Some basic support is provided for operations on memory not
2310 normally accessible to U-Boot - e.g. some architectures
2311 support access to more than 4GB of memory on 32-bit
2312 machines using physical address extension or similar.
2313 Define CONFIG_PHYSMEM to access this basic support, which
2314 currently only supports clearing the memory.
2319 Define this variable to stop the system in case of a
2320 fatal error, so that you have to reset it manually.
2321 This is probably NOT a good idea for an embedded
2322 system where you want the system to reboot
2323 automatically as fast as possible, but it may be
2324 useful during development since you can try to debug
2325 the conditions that lead to the situation.
2327 CONFIG_NET_RETRY_COUNT
2329 This variable defines the number of retries for
2330 network operations like ARP, RARP, TFTP, or BOOTP
2331 before giving up the operation. If not defined, a
2332 default value of 5 is used.
2336 Timeout waiting for an ARP reply in milliseconds.
2340 Timeout in milliseconds used in NFS protocol.
2341 If you encounter "ERROR: Cannot umount" in nfs command,
2342 try longer timeout such as
2343 #define CONFIG_NFS_TIMEOUT 10000UL
2345 - Command Interpreter:
2346 CONFIG_AUTO_COMPLETE
2348 Enable auto completion of commands using TAB.
2350 Note that this feature has NOT been implemented yet
2351 for the "hush" shell.
2354 CONFIG_SYS_HUSH_PARSER
2356 Define this variable to enable the "hush" shell (from
2357 Busybox) as command line interpreter, thus enabling
2358 powerful command line syntax like
2359 if...then...else...fi conditionals or `&&' and '||'
2360 constructs ("shell scripts").
2362 If undefined, you get the old, much simpler behaviour
2363 with a somewhat smaller memory footprint.
2366 CONFIG_SYS_PROMPT_HUSH_PS2
2368 This defines the secondary prompt string, which is
2369 printed when the command interpreter needs more input
2370 to complete a command. Usually "> ".
2374 In the current implementation, the local variables
2375 space and global environment variables space are
2376 separated. Local variables are those you define by
2377 simply typing `name=value'. To access a local
2378 variable later on, you have write `$name' or
2379 `${name}'; to execute the contents of a variable
2380 directly type `$name' at the command prompt.
2382 Global environment variables are those you use
2383 setenv/printenv to work with. To run a command stored
2384 in such a variable, you need to use the run command,
2385 and you must not use the '$' sign to access them.
2387 To store commands and special characters in a
2388 variable, please use double quotation marks
2389 surrounding the whole text of the variable, instead
2390 of the backslashes before semicolons and special
2393 - Commandline Editing and History:
2394 CONFIG_CMDLINE_EDITING
2396 Enable editing and History functions for interactive
2397 commandline input operations
2399 - Default Environment:
2400 CONFIG_EXTRA_ENV_SETTINGS
2402 Define this to contain any number of null terminated
2403 strings (variable = value pairs) that will be part of
2404 the default environment compiled into the boot image.
2406 For example, place something like this in your
2407 board's config file:
2409 #define CONFIG_EXTRA_ENV_SETTINGS \
2413 Warning: This method is based on knowledge about the
2414 internal format how the environment is stored by the
2415 U-Boot code. This is NOT an official, exported
2416 interface! Although it is unlikely that this format
2417 will change soon, there is no guarantee either.
2418 You better know what you are doing here.
2420 Note: overly (ab)use of the default environment is
2421 discouraged. Make sure to check other ways to preset
2422 the environment like the "source" command or the
2425 CONFIG_ENV_VARS_UBOOT_CONFIG
2427 Define this in order to add variables describing the
2428 U-Boot build configuration to the default environment.
2429 These will be named arch, cpu, board, vendor, and soc.
2431 Enabling this option will cause the following to be defined:
2439 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2441 Define this in order to add variables describing certain
2442 run-time determined information about the hardware to the
2443 environment. These will be named board_name, board_rev.
2445 CONFIG_DELAY_ENVIRONMENT
2447 Normally the environment is loaded when the board is
2448 intialised so that it is available to U-Boot. This inhibits
2449 that so that the environment is not available until
2450 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2451 this is instead controlled by the value of
2452 /config/load-environment.
2454 - DataFlash Support:
2455 CONFIG_HAS_DATAFLASH
2457 Defining this option enables DataFlash features and
2458 allows to read/write in Dataflash via the standard
2461 - Serial Flash support
2464 Defining this option enables SPI flash commands
2465 'sf probe/read/write/erase/update'.
2467 Usage requires an initial 'probe' to define the serial
2468 flash parameters, followed by read/write/erase/update
2471 The following defaults may be provided by the platform
2472 to handle the common case when only a single serial
2473 flash is present on the system.
2475 CONFIG_SF_DEFAULT_BUS Bus identifier
2476 CONFIG_SF_DEFAULT_CS Chip-select
2477 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2478 CONFIG_SF_DEFAULT_SPEED in Hz
2482 Define this option to include a destructive SPI flash
2485 - SystemACE Support:
2488 Adding this option adds support for Xilinx SystemACE
2489 chips attached via some sort of local bus. The address
2490 of the chip must also be defined in the
2491 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2493 #define CONFIG_SYSTEMACE
2494 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2496 When SystemACE support is added, the "ace" device type
2497 becomes available to the fat commands, i.e. fatls.
2499 - TFTP Fixed UDP Port:
2502 If this is defined, the environment variable tftpsrcp
2503 is used to supply the TFTP UDP source port value.
2504 If tftpsrcp isn't defined, the normal pseudo-random port
2505 number generator is used.
2507 Also, the environment variable tftpdstp is used to supply
2508 the TFTP UDP destination port value. If tftpdstp isn't
2509 defined, the normal port 69 is used.
2511 The purpose for tftpsrcp is to allow a TFTP server to
2512 blindly start the TFTP transfer using the pre-configured
2513 target IP address and UDP port. This has the effect of
2514 "punching through" the (Windows XP) firewall, allowing
2515 the remainder of the TFTP transfer to proceed normally.
2516 A better solution is to properly configure the firewall,
2517 but sometimes that is not allowed.
2522 This enables a generic 'hash' command which can produce
2523 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2527 Enable the hash verify command (hash -v). This adds to code
2530 CONFIG_SHA1 - support SHA1 hashing
2531 CONFIG_SHA256 - support SHA256 hashing
2533 Note: There is also a sha1sum command, which should perhaps
2534 be deprecated in favour of 'hash sha1'.
2536 - Show boot progress:
2537 CONFIG_SHOW_BOOT_PROGRESS
2539 Defining this option allows to add some board-
2540 specific code (calling a user-provided function
2541 "show_boot_progress(int)") that enables you to show
2542 the system's boot progress on some display (for
2543 example, some LED's) on your board. At the moment,
2544 the following checkpoints are implemented:
2546 - Detailed boot stage timing
2548 Define this option to get detailed timing of each stage
2549 of the boot process.
2551 CONFIG_BOOTSTAGE_USER_COUNT
2552 This is the number of available user bootstage records.
2553 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2554 a new ID will be allocated from this stash. If you exceed
2555 the limit, recording will stop.
2557 CONFIG_BOOTSTAGE_REPORT
2558 Define this to print a report before boot, similar to this:
2560 Timer summary in microseconds:
2563 3,575,678 3,575,678 board_init_f start
2564 3,575,695 17 arch_cpu_init A9
2565 3,575,777 82 arch_cpu_init done
2566 3,659,598 83,821 board_init_r start
2567 3,910,375 250,777 main_loop
2568 29,916,167 26,005,792 bootm_start
2569 30,361,327 445,160 start_kernel
2571 CONFIG_CMD_BOOTSTAGE
2572 Add a 'bootstage' command which supports printing a report
2573 and un/stashing of bootstage data.
2575 CONFIG_BOOTSTAGE_FDT
2576 Stash the bootstage information in the FDT. A root 'bootstage'
2577 node is created with each bootstage id as a child. Each child
2578 has a 'name' property and either 'mark' containing the
2579 mark time in microsecond, or 'accum' containing the
2580 accumulated time for that bootstage id in microseconds.
2585 name = "board_init_f";
2594 Code in the Linux kernel can find this in /proc/devicetree.
2596 Legacy uImage format:
2599 1 common/cmd_bootm.c before attempting to boot an image
2600 -1 common/cmd_bootm.c Image header has bad magic number
2601 2 common/cmd_bootm.c Image header has correct magic number
2602 -2 common/cmd_bootm.c Image header has bad checksum
2603 3 common/cmd_bootm.c Image header has correct checksum
2604 -3 common/cmd_bootm.c Image data has bad checksum
2605 4 common/cmd_bootm.c Image data has correct checksum
2606 -4 common/cmd_bootm.c Image is for unsupported architecture
2607 5 common/cmd_bootm.c Architecture check OK
2608 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2609 6 common/cmd_bootm.c Image Type check OK
2610 -6 common/cmd_bootm.c gunzip uncompression error
2611 -7 common/cmd_bootm.c Unimplemented compression type
2612 7 common/cmd_bootm.c Uncompression OK
2613 8 common/cmd_bootm.c No uncompress/copy overwrite error
2614 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2616 9 common/image.c Start initial ramdisk verification
2617 -10 common/image.c Ramdisk header has bad magic number
2618 -11 common/image.c Ramdisk header has bad checksum
2619 10 common/image.c Ramdisk header is OK
2620 -12 common/image.c Ramdisk data has bad checksum
2621 11 common/image.c Ramdisk data has correct checksum
2622 12 common/image.c Ramdisk verification complete, start loading
2623 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2624 13 common/image.c Start multifile image verification
2625 14 common/image.c No initial ramdisk, no multifile, continue.
2627 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2629 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2630 -31 post/post.c POST test failed, detected by post_output_backlog()
2631 -32 post/post.c POST test failed, detected by post_run_single()
2633 34 common/cmd_doc.c before loading a Image from a DOC device
2634 -35 common/cmd_doc.c Bad usage of "doc" command
2635 35 common/cmd_doc.c correct usage of "doc" command
2636 -36 common/cmd_doc.c No boot device
2637 36 common/cmd_doc.c correct boot device
2638 -37 common/cmd_doc.c Unknown Chip ID on boot device
2639 37 common/cmd_doc.c correct chip ID found, device available
2640 -38 common/cmd_doc.c Read Error on boot device
2641 38 common/cmd_doc.c reading Image header from DOC device OK
2642 -39 common/cmd_doc.c Image header has bad magic number
2643 39 common/cmd_doc.c Image header has correct magic number
2644 -40 common/cmd_doc.c Error reading Image from DOC device
2645 40 common/cmd_doc.c Image header has correct magic number
2646 41 common/cmd_ide.c before loading a Image from a IDE device
2647 -42 common/cmd_ide.c Bad usage of "ide" command
2648 42 common/cmd_ide.c correct usage of "ide" command
2649 -43 common/cmd_ide.c No boot device
2650 43 common/cmd_ide.c boot device found
2651 -44 common/cmd_ide.c Device not available
2652 44 common/cmd_ide.c Device available
2653 -45 common/cmd_ide.c wrong partition selected
2654 45 common/cmd_ide.c partition selected
2655 -46 common/cmd_ide.c Unknown partition table
2656 46 common/cmd_ide.c valid partition table found
2657 -47 common/cmd_ide.c Invalid partition type
2658 47 common/cmd_ide.c correct partition type
2659 -48 common/cmd_ide.c Error reading Image Header on boot device
2660 48 common/cmd_ide.c reading Image Header from IDE device OK
2661 -49 common/cmd_ide.c Image header has bad magic number
2662 49 common/cmd_ide.c Image header has correct magic number
2663 -50 common/cmd_ide.c Image header has bad checksum
2664 50 common/cmd_ide.c Image header has correct checksum
2665 -51 common/cmd_ide.c Error reading Image from IDE device
2666 51 common/cmd_ide.c reading Image from IDE device OK
2667 52 common/cmd_nand.c before loading a Image from a NAND device
2668 -53 common/cmd_nand.c Bad usage of "nand" command
2669 53 common/cmd_nand.c correct usage of "nand" command
2670 -54 common/cmd_nand.c No boot device
2671 54 common/cmd_nand.c boot device found
2672 -55 common/cmd_nand.c Unknown Chip ID on boot device
2673 55 common/cmd_nand.c correct chip ID found, device available
2674 -56 common/cmd_nand.c Error reading Image Header on boot device
2675 56 common/cmd_nand.c reading Image Header from NAND device OK
2676 -57 common/cmd_nand.c Image header has bad magic number
2677 57 common/cmd_nand.c Image header has correct magic number
2678 -58 common/cmd_nand.c Error reading Image from NAND device
2679 58 common/cmd_nand.c reading Image from NAND device OK
2681 -60 common/env_common.c Environment has a bad CRC, using default
2683 64 net/eth.c starting with Ethernet configuration.
2684 -64 net/eth.c no Ethernet found.
2685 65 net/eth.c Ethernet found.
2687 -80 common/cmd_net.c usage wrong
2688 80 common/cmd_net.c before calling NetLoop()
2689 -81 common/cmd_net.c some error in NetLoop() occurred
2690 81 common/cmd_net.c NetLoop() back without error
2691 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2692 82 common/cmd_net.c trying automatic boot
2693 83 common/cmd_net.c running "source" command
2694 -83 common/cmd_net.c some error in automatic boot or "source" command
2695 84 common/cmd_net.c end without errors
2700 100 common/cmd_bootm.c Kernel FIT Image has correct format
2701 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2702 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2703 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2704 102 common/cmd_bootm.c Kernel unit name specified
2705 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2706 103 common/cmd_bootm.c Found configuration node
2707 104 common/cmd_bootm.c Got kernel subimage node offset
2708 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2709 105 common/cmd_bootm.c Kernel subimage hash verification OK
2710 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2711 106 common/cmd_bootm.c Architecture check OK
2712 -106 common/cmd_bootm.c Kernel subimage has wrong type
2713 107 common/cmd_bootm.c Kernel subimage type OK
2714 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2715 108 common/cmd_bootm.c Got kernel subimage data/size
2716 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2717 -109 common/cmd_bootm.c Can't get kernel subimage type
2718 -110 common/cmd_bootm.c Can't get kernel subimage comp
2719 -111 common/cmd_bootm.c Can't get kernel subimage os
2720 -112 common/cmd_bootm.c Can't get kernel subimage load address
2721 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2723 120 common/image.c Start initial ramdisk verification
2724 -120 common/image.c Ramdisk FIT image has incorrect format
2725 121 common/image.c Ramdisk FIT image has correct format
2726 122 common/image.c No ramdisk subimage unit name, using configuration
2727 -122 common/image.c Can't get configuration for ramdisk subimage
2728 123 common/image.c Ramdisk unit name specified
2729 -124 common/image.c Can't get ramdisk subimage node offset
2730 125 common/image.c Got ramdisk subimage node offset
2731 -125 common/image.c Ramdisk subimage hash verification failed
2732 126 common/image.c Ramdisk subimage hash verification OK
2733 -126 common/image.c Ramdisk subimage for unsupported architecture
2734 127 common/image.c Architecture check OK
2735 -127 common/image.c Can't get ramdisk subimage data/size
2736 128 common/image.c Got ramdisk subimage data/size
2737 129 common/image.c Can't get ramdisk load address
2738 -129 common/image.c Got ramdisk load address
2740 -130 common/cmd_doc.c Incorrect FIT image format
2741 131 common/cmd_doc.c FIT image format OK
2743 -140 common/cmd_ide.c Incorrect FIT image format
2744 141 common/cmd_ide.c FIT image format OK
2746 -150 common/cmd_nand.c Incorrect FIT image format
2747 151 common/cmd_nand.c FIT image format OK
2749 - FIT image support:
2751 Enable support for the FIT uImage format.
2753 CONFIG_FIT_BEST_MATCH
2754 When no configuration is explicitly selected, default to the
2755 one whose fdt's compatibility field best matches that of
2756 U-Boot itself. A match is considered "best" if it matches the
2757 most specific compatibility entry of U-Boot's fdt's root node.
2758 The order of entries in the configuration's fdt is ignored.
2760 - Standalone program support:
2761 CONFIG_STANDALONE_LOAD_ADDR
2763 This option defines a board specific value for the
2764 address where standalone program gets loaded, thus
2765 overwriting the architecture dependent default
2768 - Frame Buffer Address:
2771 Define CONFIG_FB_ADDR if you want to use specific
2772 address for frame buffer. This is typically the case
2773 when using a graphics controller has separate video
2774 memory. U-Boot will then place the frame buffer at
2775 the given address instead of dynamically reserving it
2776 in system RAM by calling lcd_setmem(), which grabs
2777 the memory for the frame buffer depending on the
2778 configured panel size.
2780 Please see board_init_f function.
2782 - Automatic software updates via TFTP server
2784 CONFIG_UPDATE_TFTP_CNT_MAX
2785 CONFIG_UPDATE_TFTP_MSEC_MAX
2787 These options enable and control the auto-update feature;
2788 for a more detailed description refer to doc/README.update.
2790 - MTD Support (mtdparts command, UBI support)
2793 Adds the MTD device infrastructure from the Linux kernel.
2794 Needed for mtdparts command support.
2796 CONFIG_MTD_PARTITIONS
2798 Adds the MTD partitioning infrastructure from the Linux
2799 kernel. Needed for UBI support.
2804 Adds commands for interacting with MTD partitions formatted
2805 with the UBI flash translation layer
2807 Requires also defining CONFIG_RBTREE
2809 CONFIG_UBI_SILENCE_MSG
2811 Make the verbose messages from UBI stop printing. This leaves
2812 warnings and errors enabled.
2817 Adds commands for interacting with UBI volumes formatted as
2818 UBIFS. UBIFS is read-only in u-boot.
2820 Requires UBI support as well as CONFIG_LZO
2822 CONFIG_UBIFS_SILENCE_MSG
2824 Make the verbose messages from UBIFS stop printing. This leaves
2825 warnings and errors enabled.
2829 Enable building of SPL globally.
2832 LDSCRIPT for linking the SPL binary.
2834 CONFIG_SPL_MAX_FOOTPRINT
2835 Maximum size in memory allocated to the SPL, BSS included.
2836 When defined, the linker checks that the actual memory
2837 used by SPL from _start to __bss_end does not exceed it.
2838 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2839 must not be both defined at the same time.
2842 Maximum size of the SPL image (text, data, rodata, and
2843 linker lists sections), BSS excluded.
2844 When defined, the linker checks that the actual size does
2847 CONFIG_SPL_TEXT_BASE
2848 TEXT_BASE for linking the SPL binary.
2850 CONFIG_SPL_RELOC_TEXT_BASE
2851 Address to relocate to. If unspecified, this is equal to
2852 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2854 CONFIG_SPL_BSS_START_ADDR
2855 Link address for the BSS within the SPL binary.
2857 CONFIG_SPL_BSS_MAX_SIZE
2858 Maximum size in memory allocated to the SPL BSS.
2859 When defined, the linker checks that the actual memory used
2860 by SPL from __bss_start to __bss_end does not exceed it.
2861 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2862 must not be both defined at the same time.
2865 Adress of the start of the stack SPL will use
2867 CONFIG_SPL_RELOC_STACK
2868 Adress of the start of the stack SPL will use after
2869 relocation. If unspecified, this is equal to
2872 CONFIG_SYS_SPL_MALLOC_START
2873 Starting address of the malloc pool used in SPL.
2875 CONFIG_SYS_SPL_MALLOC_SIZE
2876 The size of the malloc pool used in SPL.
2878 CONFIG_SPL_FRAMEWORK
2879 Enable the SPL framework under common/. This framework
2880 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2881 NAND loading of the Linux Kernel.
2883 CONFIG_SPL_DISPLAY_PRINT
2884 For ARM, enable an optional function to print more information
2885 about the running system.
2887 CONFIG_SPL_INIT_MINIMAL
2888 Arch init code should be built for a very small image
2890 CONFIG_SPL_LIBCOMMON_SUPPORT
2891 Support for common/libcommon.o in SPL binary
2893 CONFIG_SPL_LIBDISK_SUPPORT
2894 Support for disk/libdisk.o in SPL binary
2896 CONFIG_SPL_I2C_SUPPORT
2897 Support for drivers/i2c/libi2c.o in SPL binary
2899 CONFIG_SPL_GPIO_SUPPORT
2900 Support for drivers/gpio/libgpio.o in SPL binary
2902 CONFIG_SPL_MMC_SUPPORT
2903 Support for drivers/mmc/libmmc.o in SPL binary
2905 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2906 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2907 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2908 Address, size and partition on the MMC to load U-Boot from
2909 when the MMC is being used in raw mode.
2911 CONFIG_SPL_FAT_SUPPORT
2912 Support for fs/fat/libfat.o in SPL binary
2914 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2915 Filename to read to load U-Boot when reading from FAT
2917 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2918 Set this for NAND SPL on PPC mpc83xx targets, so that
2919 start.S waits for the rest of the SPL to load before
2920 continuing (the hardware starts execution after just
2921 loading the first page rather than the full 4K).
2923 CONFIG_SPL_NAND_BASE
2924 Include nand_base.c in the SPL. Requires
2925 CONFIG_SPL_NAND_DRIVERS.
2927 CONFIG_SPL_NAND_DRIVERS
2928 SPL uses normal NAND drivers, not minimal drivers.
2931 Include standard software ECC in the SPL
2933 CONFIG_SPL_NAND_SIMPLE
2934 Support for NAND boot using simple NAND drivers that
2935 expose the cmd_ctrl() interface.
2937 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2938 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2939 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2940 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2941 CONFIG_SYS_NAND_ECCBYTES
2942 Defines the size and behavior of the NAND that SPL uses
2945 CONFIG_SYS_NAND_U_BOOT_OFFS
2946 Location in NAND to read U-Boot from
2948 CONFIG_SYS_NAND_U_BOOT_DST
2949 Location in memory to load U-Boot to
2951 CONFIG_SYS_NAND_U_BOOT_SIZE
2952 Size of image to load
2954 CONFIG_SYS_NAND_U_BOOT_START
2955 Entry point in loaded image to jump to
2957 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2958 Define this if you need to first read the OOB and then the
2959 data. This is used for example on davinci plattforms.
2961 CONFIG_SPL_OMAP3_ID_NAND
2962 Support for an OMAP3-specific set of functions to return the
2963 ID and MFR of the first attached NAND chip, if present.
2965 CONFIG_SPL_SERIAL_SUPPORT
2966 Support for drivers/serial/libserial.o in SPL binary
2968 CONFIG_SPL_SPI_FLASH_SUPPORT
2969 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2971 CONFIG_SPL_SPI_SUPPORT
2972 Support for drivers/spi/libspi.o in SPL binary
2974 CONFIG_SPL_RAM_DEVICE
2975 Support for running image already present in ram, in SPL binary
2977 CONFIG_SPL_LIBGENERIC_SUPPORT
2978 Support for lib/libgeneric.o in SPL binary
2981 Image offset to which the SPL should be padded before appending
2982 the SPL payload. By default, this is defined as
2983 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2984 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2985 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
2988 Final target image containing SPL and payload. Some SPLs
2989 use an arch-specific makefile fragment instead, for
2990 example if more than one image needs to be produced.
2995 [so far only for SMDK2400 boards]
2997 - Modem support enable:
2998 CONFIG_MODEM_SUPPORT
3000 - RTS/CTS Flow control enable:
3003 - Modem debug support:
3004 CONFIG_MODEM_SUPPORT_DEBUG
3006 Enables debugging stuff (char screen[1024], dbg())
3007 for modem support. Useful only with BDI2000.
3009 - Interrupt support (PPC):
3011 There are common interrupt_init() and timer_interrupt()
3012 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3013 for CPU specific initialization. interrupt_init_cpu()
3014 should set decrementer_count to appropriate value. If
3015 CPU resets decrementer automatically after interrupt
3016 (ppc4xx) it should set decrementer_count to zero.
3017 timer_interrupt() calls timer_interrupt_cpu() for CPU
3018 specific handling. If board has watchdog / status_led
3019 / other_activity_monitor it works automatically from
3020 general timer_interrupt().
3024 In the target system modem support is enabled when a
3025 specific key (key combination) is pressed during
3026 power-on. Otherwise U-Boot will boot normally
3027 (autoboot). The key_pressed() function is called from
3028 board_init(). Currently key_pressed() is a dummy
3029 function, returning 1 and thus enabling modem
3032 If there are no modem init strings in the
3033 environment, U-Boot proceed to autoboot; the
3034 previous output (banner, info printfs) will be
3037 See also: doc/README.Modem
3039 Board initialization settings:
3040 ------------------------------
3042 During Initialization u-boot calls a number of board specific functions
3043 to allow the preparation of board specific prerequisites, e.g. pin setup
3044 before drivers are initialized. To enable these callbacks the
3045 following configuration macros have to be defined. Currently this is
3046 architecture specific, so please check arch/your_architecture/lib/board.c
3047 typically in board_init_f() and board_init_r().
3049 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3050 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3051 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3052 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3054 Configuration Settings:
3055 -----------------------
3057 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3058 undefine this when you're short of memory.
3060 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3061 width of the commands listed in the 'help' command output.
3063 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3064 prompt for user input.
3066 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3068 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3070 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3072 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3073 the application (usually a Linux kernel) when it is
3076 - CONFIG_SYS_BAUDRATE_TABLE:
3077 List of legal baudrate settings for this board.
3079 - CONFIG_SYS_CONSOLE_INFO_QUIET
3080 Suppress display of console information at boot.
3082 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3083 If the board specific function
3084 extern int overwrite_console (void);
3085 returns 1, the stdin, stderr and stdout are switched to the
3086 serial port, else the settings in the environment are used.
3088 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3089 Enable the call to overwrite_console().
3091 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3092 Enable overwrite of previous console environment settings.
3094 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3095 Begin and End addresses of the area used by the
3098 - CONFIG_SYS_ALT_MEMTEST:
3099 Enable an alternate, more extensive memory test.
3101 - CONFIG_SYS_MEMTEST_SCRATCH:
3102 Scratch address used by the alternate memory test
3103 You only need to set this if address zero isn't writeable
3105 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3106 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3107 this specified memory area will get subtracted from the top
3108 (end) of RAM and won't get "touched" at all by U-Boot. By
3109 fixing up gd->ram_size the Linux kernel should gets passed
3110 the now "corrected" memory size and won't touch it either.
3111 This should work for arch/ppc and arch/powerpc. Only Linux
3112 board ports in arch/powerpc with bootwrapper support that
3113 recalculate the memory size from the SDRAM controller setup
3114 will have to get fixed in Linux additionally.
3116 This option can be used as a workaround for the 440EPx/GRx
3117 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3120 WARNING: Please make sure that this value is a multiple of
3121 the Linux page size (normally 4k). If this is not the case,
3122 then the end address of the Linux memory will be located at a
3123 non page size aligned address and this could cause major
3126 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3127 Enable temporary baudrate change while serial download
3129 - CONFIG_SYS_SDRAM_BASE:
3130 Physical start address of SDRAM. _Must_ be 0 here.
3132 - CONFIG_SYS_MBIO_BASE:
3133 Physical start address of Motherboard I/O (if using a
3136 - CONFIG_SYS_FLASH_BASE:
3137 Physical start address of Flash memory.
3139 - CONFIG_SYS_MONITOR_BASE:
3140 Physical start address of boot monitor code (set by
3141 make config files to be same as the text base address
3142 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3143 CONFIG_SYS_FLASH_BASE when booting from flash.
3145 - CONFIG_SYS_MONITOR_LEN:
3146 Size of memory reserved for monitor code, used to
3147 determine _at_compile_time_ (!) if the environment is
3148 embedded within the U-Boot image, or in a separate
3151 - CONFIG_SYS_MALLOC_LEN:
3152 Size of DRAM reserved for malloc() use.
3154 - CONFIG_SYS_BOOTM_LEN:
3155 Normally compressed uImages are limited to an
3156 uncompressed size of 8 MBytes. If this is not enough,
3157 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3158 to adjust this setting to your needs.
3160 - CONFIG_SYS_BOOTMAPSZ:
3161 Maximum size of memory mapped by the startup code of
3162 the Linux kernel; all data that must be processed by
3163 the Linux kernel (bd_info, boot arguments, FDT blob if
3164 used) must be put below this limit, unless "bootm_low"
3165 enviroment variable is defined and non-zero. In such case
3166 all data for the Linux kernel must be between "bootm_low"
3167 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3168 variable "bootm_mapsize" will override the value of
3169 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3170 then the value in "bootm_size" will be used instead.
3172 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3173 Enable initrd_high functionality. If defined then the
3174 initrd_high feature is enabled and the bootm ramdisk subcommand
3177 - CONFIG_SYS_BOOT_GET_CMDLINE:
3178 Enables allocating and saving kernel cmdline in space between
3179 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3181 - CONFIG_SYS_BOOT_GET_KBD:
3182 Enables allocating and saving a kernel copy of the bd_info in
3183 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3185 - CONFIG_SYS_MAX_FLASH_BANKS:
3186 Max number of Flash memory banks
3188 - CONFIG_SYS_MAX_FLASH_SECT:
3189 Max number of sectors on a Flash chip
3191 - CONFIG_SYS_FLASH_ERASE_TOUT:
3192 Timeout for Flash erase operations (in ms)
3194 - CONFIG_SYS_FLASH_WRITE_TOUT:
3195 Timeout for Flash write operations (in ms)
3197 - CONFIG_SYS_FLASH_LOCK_TOUT
3198 Timeout for Flash set sector lock bit operation (in ms)
3200 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3201 Timeout for Flash clear lock bits operation (in ms)
3203 - CONFIG_SYS_FLASH_PROTECTION
3204 If defined, hardware flash sectors protection is used
3205 instead of U-Boot software protection.
3207 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3209 Enable TFTP transfers directly to flash memory;
3210 without this option such a download has to be
3211 performed in two steps: (1) download to RAM, and (2)
3212 copy from RAM to flash.
3214 The two-step approach is usually more reliable, since
3215 you can check if the download worked before you erase
3216 the flash, but in some situations (when system RAM is
3217 too limited to allow for a temporary copy of the
3218 downloaded image) this option may be very useful.
3220 - CONFIG_SYS_FLASH_CFI:
3221 Define if the flash driver uses extra elements in the
3222 common flash structure for storing flash geometry.
3224 - CONFIG_FLASH_CFI_DRIVER
3225 This option also enables the building of the cfi_flash driver
3226 in the drivers directory
3228 - CONFIG_FLASH_CFI_MTD
3229 This option enables the building of the cfi_mtd driver
3230 in the drivers directory. The driver exports CFI flash
3233 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3234 Use buffered writes to flash.
3236 - CONFIG_FLASH_SPANSION_S29WS_N
3237 s29ws-n MirrorBit flash has non-standard addresses for buffered
3240 - CONFIG_SYS_FLASH_QUIET_TEST
3241 If this option is defined, the common CFI flash doesn't
3242 print it's warning upon not recognized FLASH banks. This
3243 is useful, if some of the configured banks are only
3244 optionally available.
3246 - CONFIG_FLASH_SHOW_PROGRESS
3247 If defined (must be an integer), print out countdown
3248 digits and dots. Recommended value: 45 (9..1) for 80
3249 column displays, 15 (3..1) for 40 column displays.
3251 - CONFIG_SYS_RX_ETH_BUFFER:
3252 Defines the number of Ethernet receive buffers. On some
3253 Ethernet controllers it is recommended to set this value
3254 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3255 buffers can be full shortly after enabling the interface
3256 on high Ethernet traffic.
3257 Defaults to 4 if not defined.
3259 - CONFIG_ENV_MAX_ENTRIES
3261 Maximum number of entries in the hash table that is used
3262 internally to store the environment settings. The default
3263 setting is supposed to be generous and should work in most
3264 cases. This setting can be used to tune behaviour; see
3265 lib/hashtable.c for details.
3267 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3268 - CONFIG_ENV_FLAGS_LIST_STATIC
3269 Enable validation of the values given to enviroment variables when
3270 calling env set. Variables can be restricted to only decimal,
3271 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3272 the variables can also be restricted to IP address or MAC address.
3274 The format of the list is:
3275 type_attribute = [s|d|x|b|i|m]
3276 access_atribute = [a|r|o|c]
3277 attributes = type_attribute[access_atribute]
3278 entry = variable_name[:attributes]
3281 The type attributes are:
3282 s - String (default)
3285 b - Boolean ([1yYtT|0nNfF])
3289 The access attributes are:
3295 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3296 Define this to a list (string) to define the ".flags"
3297 envirnoment variable in the default or embedded environment.
3299 - CONFIG_ENV_FLAGS_LIST_STATIC
3300 Define this to a list (string) to define validation that
3301 should be done if an entry is not found in the ".flags"
3302 environment variable. To override a setting in the static
3303 list, simply add an entry for the same variable name to the
3306 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3307 If defined, don't allow the -f switch to env set override variable
3310 - CONFIG_SYS_GENERIC_BOARD
3311 This selects the architecture-generic board system instead of the
3312 architecture-specific board files. It is intended to move boards
3313 to this new framework over time. Defining this will disable the
3314 arch/foo/lib/board.c file and use common/board_f.c and
3315 common/board_r.c instead. To use this option your architecture
3316 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3317 its config.mk file). If you find problems enabling this option on
3318 your board please report the problem and send patches!
3320 - CONFIG_SYS_SYM_OFFSETS
3321 This is set by architectures that use offsets for link symbols
3322 instead of absolute values. So bss_start is obtained using an
3323 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3324 directly. You should not need to touch this setting.
3327 The following definitions that deal with the placement and management
3328 of environment data (variable area); in general, we support the
3329 following configurations:
3331 - CONFIG_BUILD_ENVCRC:
3333 Builds up envcrc with the target environment so that external utils
3334 may easily extract it and embed it in final U-Boot images.
3336 - CONFIG_ENV_IS_IN_FLASH:
3338 Define this if the environment is in flash memory.
3340 a) The environment occupies one whole flash sector, which is
3341 "embedded" in the text segment with the U-Boot code. This
3342 happens usually with "bottom boot sector" or "top boot
3343 sector" type flash chips, which have several smaller
3344 sectors at the start or the end. For instance, such a
3345 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3346 such a case you would place the environment in one of the
3347 4 kB sectors - with U-Boot code before and after it. With
3348 "top boot sector" type flash chips, you would put the
3349 environment in one of the last sectors, leaving a gap
3350 between U-Boot and the environment.
3352 - CONFIG_ENV_OFFSET:
3354 Offset of environment data (variable area) to the
3355 beginning of flash memory; for instance, with bottom boot
3356 type flash chips the second sector can be used: the offset
3357 for this sector is given here.
3359 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3363 This is just another way to specify the start address of
3364 the flash sector containing the environment (instead of
3367 - CONFIG_ENV_SECT_SIZE:
3369 Size of the sector containing the environment.
3372 b) Sometimes flash chips have few, equal sized, BIG sectors.
3373 In such a case you don't want to spend a whole sector for
3378 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3379 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3380 of this flash sector for the environment. This saves
3381 memory for the RAM copy of the environment.
3383 It may also save flash memory if you decide to use this
3384 when your environment is "embedded" within U-Boot code,
3385 since then the remainder of the flash sector could be used
3386 for U-Boot code. It should be pointed out that this is
3387 STRONGLY DISCOURAGED from a robustness point of view:
3388 updating the environment in flash makes it always
3389 necessary to erase the WHOLE sector. If something goes
3390 wrong before the contents has been restored from a copy in
3391 RAM, your target system will be dead.
3393 - CONFIG_ENV_ADDR_REDUND
3394 CONFIG_ENV_SIZE_REDUND
3396 These settings describe a second storage area used to hold
3397 a redundant copy of the environment data, so that there is
3398 a valid backup copy in case there is a power failure during
3399 a "saveenv" operation.
3401 BE CAREFUL! Any changes to the flash layout, and some changes to the
3402 source code will make it necessary to adapt <board>/u-boot.lds*
3406 - CONFIG_ENV_IS_IN_NVRAM:
3408 Define this if you have some non-volatile memory device
3409 (NVRAM, battery buffered SRAM) which you want to use for the
3415 These two #defines are used to determine the memory area you
3416 want to use for environment. It is assumed that this memory
3417 can just be read and written to, without any special
3420 BE CAREFUL! The first access to the environment happens quite early
3421 in U-Boot initalization (when we try to get the setting of for the
3422 console baudrate). You *MUST* have mapped your NVRAM area then, or
3425 Please note that even with NVRAM we still use a copy of the
3426 environment in RAM: we could work on NVRAM directly, but we want to
3427 keep settings there always unmodified except somebody uses "saveenv"
3428 to save the current settings.
3431 - CONFIG_ENV_IS_IN_EEPROM:
3433 Use this if you have an EEPROM or similar serial access
3434 device and a driver for it.
3436 - CONFIG_ENV_OFFSET:
3439 These two #defines specify the offset and size of the
3440 environment area within the total memory of your EEPROM.
3442 - CONFIG_SYS_I2C_EEPROM_ADDR:
3443 If defined, specified the chip address of the EEPROM device.
3444 The default address is zero.
3446 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3447 If defined, the number of bits used to address bytes in a
3448 single page in the EEPROM device. A 64 byte page, for example
3449 would require six bits.
3451 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3452 If defined, the number of milliseconds to delay between
3453 page writes. The default is zero milliseconds.
3455 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3456 The length in bytes of the EEPROM memory array address. Note
3457 that this is NOT the chip address length!
3459 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3460 EEPROM chips that implement "address overflow" are ones
3461 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3462 address and the extra bits end up in the "chip address" bit
3463 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3466 Note that we consider the length of the address field to
3467 still be one byte because the extra address bits are hidden
3468 in the chip address.
3470 - CONFIG_SYS_EEPROM_SIZE:
3471 The size in bytes of the EEPROM device.
3473 - CONFIG_ENV_EEPROM_IS_ON_I2C
3474 define this, if you have I2C and SPI activated, and your
3475 EEPROM, which holds the environment, is on the I2C bus.
3477 - CONFIG_I2C_ENV_EEPROM_BUS
3478 if you have an Environment on an EEPROM reached over
3479 I2C muxes, you can define here, how to reach this
3480 EEPROM. For example:
3482 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3484 EEPROM which holds the environment, is reached over
3485 a pca9547 i2c mux with address 0x70, channel 3.
3487 - CONFIG_ENV_IS_IN_DATAFLASH:
3489 Define this if you have a DataFlash memory device which you
3490 want to use for the environment.
3492 - CONFIG_ENV_OFFSET:
3496 These three #defines specify the offset and size of the
3497 environment area within the total memory of your DataFlash placed
3498 at the specified address.
3500 - CONFIG_ENV_IS_IN_REMOTE:
3502 Define this if you have a remote memory space which you
3503 want to use for the local device's environment.
3508 These two #defines specify the address and size of the
3509 environment area within the remote memory space. The
3510 local device can get the environment from remote memory
3511 space by SRIO or PCIE links.
3513 BE CAREFUL! For some special cases, the local device can not use
3514 "saveenv" command. For example, the local device will get the
3515 environment stored in a remote NOR flash by SRIO or PCIE link,
3516 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3518 - CONFIG_ENV_IS_IN_NAND:
3520 Define this if you have a NAND device which you want to use
3521 for the environment.
3523 - CONFIG_ENV_OFFSET:
3526 These two #defines specify the offset and size of the environment
3527 area within the first NAND device. CONFIG_ENV_OFFSET must be
3528 aligned to an erase block boundary.
3530 - CONFIG_ENV_OFFSET_REDUND (optional):
3532 This setting describes a second storage area of CONFIG_ENV_SIZE
3533 size used to hold a redundant copy of the environment data, so
3534 that there is a valid backup copy in case there is a power failure
3535 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3536 aligned to an erase block boundary.
3538 - CONFIG_ENV_RANGE (optional):
3540 Specifies the length of the region in which the environment
3541 can be written. This should be a multiple of the NAND device's
3542 block size. Specifying a range with more erase blocks than
3543 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3544 the range to be avoided.
3546 - CONFIG_ENV_OFFSET_OOB (optional):
3548 Enables support for dynamically retrieving the offset of the
3549 environment from block zero's out-of-band data. The
3550 "nand env.oob" command can be used to record this offset.
3551 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3552 using CONFIG_ENV_OFFSET_OOB.
3554 - CONFIG_NAND_ENV_DST
3556 Defines address in RAM to which the nand_spl code should copy the
3557 environment. If redundant environment is used, it will be copied to
3558 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3560 - CONFIG_ENV_IS_IN_UBI:
3562 Define this if you have an UBI volume that you want to use for the
3563 environment. This has the benefit of wear-leveling the environment
3564 accesses, which is important on NAND.
3566 - CONFIG_ENV_UBI_PART:
3568 Define this to a string that is the mtd partition containing the UBI.
3570 - CONFIG_ENV_UBI_VOLUME:
3572 Define this to the name of the volume that you want to store the
3575 - CONFIG_ENV_UBI_VOLUME_REDUND:
3577 Define this to the name of another volume to store a second copy of
3578 the environment in. This will enable redundant environments in UBI.
3579 It is assumed that both volumes are in the same MTD partition.
3581 - CONFIG_UBI_SILENCE_MSG
3582 - CONFIG_UBIFS_SILENCE_MSG
3584 You will probably want to define these to avoid a really noisy system
3585 when storing the env in UBI.
3587 - CONFIG_SYS_SPI_INIT_OFFSET
3589 Defines offset to the initial SPI buffer area in DPRAM. The
3590 area is used at an early stage (ROM part) if the environment
3591 is configured to reside in the SPI EEPROM: We need a 520 byte
3592 scratch DPRAM area. It is used between the two initialization
3593 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3594 to be a good choice since it makes it far enough from the
3595 start of the data area as well as from the stack pointer.
3597 Please note that the environment is read-only until the monitor
3598 has been relocated to RAM and a RAM copy of the environment has been
3599 created; also, when using EEPROM you will have to use getenv_f()
3600 until then to read environment variables.
3602 The environment is protected by a CRC32 checksum. Before the monitor
3603 is relocated into RAM, as a result of a bad CRC you will be working
3604 with the compiled-in default environment - *silently*!!! [This is
3605 necessary, because the first environment variable we need is the
3606 "baudrate" setting for the console - if we have a bad CRC, we don't
3607 have any device yet where we could complain.]
3609 Note: once the monitor has been relocated, then it will complain if
3610 the default environment is used; a new CRC is computed as soon as you
3611 use the "saveenv" command to store a valid environment.
3613 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3614 Echo the inverted Ethernet link state to the fault LED.
3616 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3617 also needs to be defined.
3619 - CONFIG_SYS_FAULT_MII_ADDR:
3620 MII address of the PHY to check for the Ethernet link state.
3622 - CONFIG_NS16550_MIN_FUNCTIONS:
3623 Define this if you desire to only have use of the NS16550_init
3624 and NS16550_putc functions for the serial driver located at
3625 drivers/serial/ns16550.c. This option is useful for saving
3626 space for already greatly restricted images, including but not
3627 limited to NAND_SPL configurations.
3629 - CONFIG_DISPLAY_BOARDINFO
3630 Display information about the board that U-Boot is running on
3631 when U-Boot starts up. The board function checkboard() is called
3634 - CONFIG_DISPLAY_BOARDINFO_LATE
3635 Similar to the previous option, but display this information
3636 later, once stdio is running and output goes to the LCD, if
3639 Low Level (hardware related) configuration options:
3640 ---------------------------------------------------
3642 - CONFIG_SYS_CACHELINE_SIZE:
3643 Cache Line Size of the CPU.
3645 - CONFIG_SYS_DEFAULT_IMMR:
3646 Default address of the IMMR after system reset.
3648 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3649 and RPXsuper) to be able to adjust the position of
3650 the IMMR register after a reset.
3652 - CONFIG_SYS_CCSRBAR_DEFAULT:
3653 Default (power-on reset) physical address of CCSR on Freescale
3656 - CONFIG_SYS_CCSRBAR:
3657 Virtual address of CCSR. On a 32-bit build, this is typically
3658 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3660 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3661 for cross-platform code that uses that macro instead.
3663 - CONFIG_SYS_CCSRBAR_PHYS:
3664 Physical address of CCSR. CCSR can be relocated to a new
3665 physical address, if desired. In this case, this macro should
3666 be set to that address. Otherwise, it should be set to the
3667 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3668 is typically relocated on 36-bit builds. It is recommended
3669 that this macro be defined via the _HIGH and _LOW macros:
3671 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3672 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3674 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3675 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3676 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3677 used in assembly code, so it must not contain typecasts or
3678 integer size suffixes (e.g. "ULL").
3680 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3681 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3682 used in assembly code, so it must not contain typecasts or
3683 integer size suffixes (e.g. "ULL").
3685 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3686 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3687 forced to a value that ensures that CCSR is not relocated.
3689 - Floppy Disk Support:
3690 CONFIG_SYS_FDC_DRIVE_NUMBER
3692 the default drive number (default value 0)
3694 CONFIG_SYS_ISA_IO_STRIDE
3696 defines the spacing between FDC chipset registers
3699 CONFIG_SYS_ISA_IO_OFFSET
3701 defines the offset of register from address. It
3702 depends on which part of the data bus is connected to
3703 the FDC chipset. (default value 0)
3705 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3706 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3709 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3710 fdc_hw_init() is called at the beginning of the FDC
3711 setup. fdc_hw_init() must be provided by the board
3712 source code. It is used to make hardware dependant
3716 Most IDE controllers were designed to be connected with PCI
3717 interface. Only few of them were designed for AHB interface.
3718 When software is doing ATA command and data transfer to
3719 IDE devices through IDE-AHB controller, some additional
3720 registers accessing to these kind of IDE-AHB controller
3723 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3724 DO NOT CHANGE unless you know exactly what you're
3725 doing! (11-4) [MPC8xx/82xx systems only]
3727 - CONFIG_SYS_INIT_RAM_ADDR:
3729 Start address of memory area that can be used for
3730 initial data and stack; please note that this must be
3731 writable memory that is working WITHOUT special
3732 initialization, i. e. you CANNOT use normal RAM which
3733 will become available only after programming the
3734 memory controller and running certain initialization
3737 U-Boot uses the following memory types:
3738 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3739 - MPC824X: data cache
3740 - PPC4xx: data cache
3742 - CONFIG_SYS_GBL_DATA_OFFSET:
3744 Offset of the initial data structure in the memory
3745 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3746 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3747 data is located at the end of the available space
3748 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3749 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3750 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3751 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3754 On the MPC824X (or other systems that use the data
3755 cache for initial memory) the address chosen for
3756 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3757 point to an otherwise UNUSED address space between
3758 the top of RAM and the start of the PCI space.
3760 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3762 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3764 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3766 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3768 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3770 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3772 - CONFIG_SYS_OR_TIMING_SDRAM:
3775 - CONFIG_SYS_MAMR_PTA:
3776 periodic timer for refresh
3778 - CONFIG_SYS_DER: Debug Event Register (37-47)
3780 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3781 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3782 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3783 CONFIG_SYS_BR1_PRELIM:
3784 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3786 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3787 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3788 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3789 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3791 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3792 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3793 Machine Mode Register and Memory Periodic Timer
3794 Prescaler definitions (SDRAM timing)
3796 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3797 enable I2C microcode relocation patch (MPC8xx);
3798 define relocation offset in DPRAM [DSP2]
3800 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3801 enable SMC microcode relocation patch (MPC8xx);
3802 define relocation offset in DPRAM [SMC1]
3804 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3805 enable SPI microcode relocation patch (MPC8xx);
3806 define relocation offset in DPRAM [SCC4]
3808 - CONFIG_SYS_USE_OSCCLK:
3809 Use OSCM clock mode on MBX8xx board. Be careful,
3810 wrong setting might damage your board. Read
3811 doc/README.MBX before setting this variable!
3813 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3814 Offset of the bootmode word in DPRAM used by post
3815 (Power On Self Tests). This definition overrides
3816 #define'd default value in commproc.h resp.
3819 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3820 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3821 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3822 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3823 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3824 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3825 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3826 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3827 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3829 - CONFIG_PCI_DISABLE_PCIE:
3830 Disable PCI-Express on systems where it is supported but not
3833 - CONFIG_PCI_ENUM_ONLY
3834 Only scan through and get the devices on the busses.
3835 Don't do any setup work, presumably because someone or
3836 something has already done it, and we don't need to do it
3837 a second time. Useful for platforms that are pre-booted
3838 by coreboot or similar.
3841 Chip has SRIO or not
3844 Board has SRIO 1 port available
3847 Board has SRIO 2 port available
3849 - CONFIG_SYS_SRIOn_MEM_VIRT:
3850 Virtual Address of SRIO port 'n' memory region
3852 - CONFIG_SYS_SRIOn_MEM_PHYS:
3853 Physical Address of SRIO port 'n' memory region
3855 - CONFIG_SYS_SRIOn_MEM_SIZE:
3856 Size of SRIO port 'n' memory region
3858 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3859 Defined to tell the NAND controller that the NAND chip is using
3861 Not all NAND drivers use this symbol.
3862 Example of drivers that use it:
3863 - drivers/mtd/nand/ndfc.c
3864 - drivers/mtd/nand/mxc_nand.c
3866 - CONFIG_SYS_NDFC_EBC0_CFG
3867 Sets the EBC0_CFG register for the NDFC. If not defined
3868 a default value will be used.
3871 Get DDR timing information from an I2C EEPROM. Common
3872 with pluggable memory modules such as SODIMMs
3875 I2C address of the SPD EEPROM
3877 - CONFIG_SYS_SPD_BUS_NUM
3878 If SPD EEPROM is on an I2C bus other than the first
3879 one, specify here. Note that the value must resolve
3880 to something your driver can deal with.
3882 - CONFIG_SYS_DDR_RAW_TIMING
3883 Get DDR timing information from other than SPD. Common with
3884 soldered DDR chips onboard without SPD. DDR raw timing
3885 parameters are extracted from datasheet and hard-coded into
3886 header files or board specific files.
3888 - CONFIG_FSL_DDR_INTERACTIVE
3889 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3891 - CONFIG_SYS_83XX_DDR_USES_CS0
3892 Only for 83xx systems. If specified, then DDR should
3893 be configured using CS0 and CS1 instead of CS2 and CS3.
3895 - CONFIG_ETHER_ON_FEC[12]
3896 Define to enable FEC[12] on a 8xx series processor.
3898 - CONFIG_FEC[12]_PHY
3899 Define to the hardcoded PHY address which corresponds
3900 to the given FEC; i. e.
3901 #define CONFIG_FEC1_PHY 4
3902 means that the PHY with address 4 is connected to FEC1
3904 When set to -1, means to probe for first available.
3906 - CONFIG_FEC[12]_PHY_NORXERR
3907 The PHY does not have a RXERR line (RMII only).
3908 (so program the FEC to ignore it).
3911 Enable RMII mode for all FECs.
3912 Note that this is a global option, we can't
3913 have one FEC in standard MII mode and another in RMII mode.
3915 - CONFIG_CRC32_VERIFY
3916 Add a verify option to the crc32 command.
3919 => crc32 -v <address> <count> <crc32>
3921 Where address/count indicate a memory area
3922 and crc32 is the correct crc32 which the
3926 Add the "loopw" memory command. This only takes effect if
3927 the memory commands are activated globally (CONFIG_CMD_MEM).
3930 Add the "mdc" and "mwc" memory commands. These are cyclic
3935 This command will print 4 bytes (10,11,12,13) each 500 ms.
3937 => mwc.l 100 12345678 10
3938 This command will write 12345678 to address 100 all 10 ms.
3940 This only takes effect if the memory commands are activated
3941 globally (CONFIG_CMD_MEM).
3943 - CONFIG_SKIP_LOWLEVEL_INIT
3944 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3945 low level initializations (like setting up the memory
3946 controller) are omitted and/or U-Boot does not
3947 relocate itself into RAM.
3949 Normally this variable MUST NOT be defined. The only
3950 exception is when U-Boot is loaded (to RAM) by some
3951 other boot loader or by a debugger which performs
3952 these initializations itself.
3955 Modifies the behaviour of start.S when compiling a loader
3956 that is executed before the actual U-Boot. E.g. when
3957 compiling a NAND SPL.
3959 - CONFIG_ARCH_MAP_SYSMEM
3960 Generally U-Boot (and in particular the md command) uses
3961 effective address. It is therefore not necessary to regard
3962 U-Boot address as virtual addresses that need to be translated
3963 to physical addresses. However, sandbox requires this, since
3964 it maintains its own little RAM buffer which contains all
3965 addressable memory. This option causes some memory accesses
3966 to be mapped through map_sysmem() / unmap_sysmem().
3968 - CONFIG_USE_ARCH_MEMCPY
3969 CONFIG_USE_ARCH_MEMSET
3970 If these options are used a optimized version of memcpy/memset will
3971 be used if available. These functions may be faster under some
3972 conditions but may increase the binary size.
3974 - CONFIG_X86_RESET_VECTOR
3975 If defined, the x86 reset vector code is included. This is not
3976 needed when U-Boot is running from Coreboot.
3979 Defines the MPU clock speed (in MHz).
3981 NOTE : currently only supported on AM335x platforms.
3983 Freescale QE/FMAN Firmware Support:
3984 -----------------------------------
3986 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3987 loading of "firmware", which is encoded in the QE firmware binary format.
3988 This firmware often needs to be loaded during U-Boot booting, so macros
3989 are used to identify the storage device (NOR flash, SPI, etc) and the address
3992 - CONFIG_SYS_QE_FMAN_FW_ADDR
3993 The address in the storage device where the firmware is located. The
3994 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3997 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3998 The maximum possible size of the firmware. The firmware binary format
3999 has a field that specifies the actual size of the firmware, but it
4000 might not be possible to read any part of the firmware unless some
4001 local storage is allocated to hold the entire firmware first.
4003 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4004 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4005 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4006 virtual address in NOR flash.
4008 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4009 Specifies that QE/FMAN firmware is located in NAND flash.
4010 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4012 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4013 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4014 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4016 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4017 Specifies that QE/FMAN firmware is located on the primary SPI
4018 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4020 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4021 Specifies that QE/FMAN firmware is located in the remote (master)
4022 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4023 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4024 window->master inbound window->master LAW->the ucode address in
4025 master's memory space.
4027 Building the Software:
4028 ======================
4030 Building U-Boot has been tested in several native build environments
4031 and in many different cross environments. Of course we cannot support
4032 all possibly existing versions of cross development tools in all
4033 (potentially obsolete) versions. In case of tool chain problems we
4034 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4035 which is extensively used to build and test U-Boot.
4037 If you are not using a native environment, it is assumed that you
4038 have GNU cross compiling tools available in your path. In this case,
4039 you must set the environment variable CROSS_COMPILE in your shell.
4040 Note that no changes to the Makefile or any other source files are
4041 necessary. For example using the ELDK on a 4xx CPU, please enter:
4043 $ CROSS_COMPILE=ppc_4xx-
4044 $ export CROSS_COMPILE
4046 Note: If you wish to generate Windows versions of the utilities in
4047 the tools directory you can use the MinGW toolchain
4048 (http://www.mingw.org). Set your HOST tools to the MinGW
4049 toolchain and execute 'make tools'. For example:
4051 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4053 Binaries such as tools/mkimage.exe will be created which can
4054 be executed on computers running Windows.
4056 U-Boot is intended to be simple to build. After installing the
4057 sources you must configure U-Boot for one specific board type. This
4062 where "NAME_config" is the name of one of the existing configu-
4063 rations; see boards.cfg for supported names.
4065 Note: for some board special configuration names may exist; check if
4066 additional information is available from the board vendor; for
4067 instance, the TQM823L systems are available without (standard)
4068 or with LCD support. You can select such additional "features"
4069 when choosing the configuration, i. e.
4072 - will configure for a plain TQM823L, i. e. no LCD support
4074 make TQM823L_LCD_config
4075 - will configure for a TQM823L with U-Boot console on LCD
4080 Finally, type "make all", and you should get some working U-Boot
4081 images ready for download to / installation on your system:
4083 - "u-boot.bin" is a raw binary image
4084 - "u-boot" is an image in ELF binary format
4085 - "u-boot.srec" is in Motorola S-Record format
4087 By default the build is performed locally and the objects are saved
4088 in the source directory. One of the two methods can be used to change
4089 this behavior and build U-Boot to some external directory:
4091 1. Add O= to the make command line invocations:
4093 make O=/tmp/build distclean
4094 make O=/tmp/build NAME_config
4095 make O=/tmp/build all
4097 2. Set environment variable BUILD_DIR to point to the desired location:
4099 export BUILD_DIR=/tmp/build
4104 Note that the command line "O=" setting overrides the BUILD_DIR environment
4108 Please be aware that the Makefiles assume you are using GNU make, so
4109 for instance on NetBSD you might need to use "gmake" instead of
4113 If the system board that you have is not listed, then you will need
4114 to port U-Boot to your hardware platform. To do this, follow these
4117 1. Add a new configuration option for your board to the toplevel
4118 "boards.cfg" file, using the existing entries as examples.
4119 Follow the instructions there to keep the boards in order.
4120 2. Create a new directory to hold your board specific code. Add any
4121 files you need. In your board directory, you will need at least
4122 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4123 3. Create a new configuration file "include/configs/<board>.h" for
4125 3. If you're porting U-Boot to a new CPU, then also create a new
4126 directory to hold your CPU specific code. Add any files you need.
4127 4. Run "make <board>_config" with your new name.
4128 5. Type "make", and you should get a working "u-boot.srec" file
4129 to be installed on your target system.
4130 6. Debug and solve any problems that might arise.
4131 [Of course, this last step is much harder than it sounds.]
4134 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4135 ==============================================================
4137 If you have modified U-Boot sources (for instance added a new board
4138 or support for new devices, a new CPU, etc.) you are expected to
4139 provide feedback to the other developers. The feedback normally takes
4140 the form of a "patch", i. e. a context diff against a certain (latest
4141 official or latest in the git repository) version of U-Boot sources.
4143 But before you submit such a patch, please verify that your modifi-
4144 cation did not break existing code. At least make sure that *ALL* of
4145 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4146 just run the "MAKEALL" script, which will configure and build U-Boot
4147 for ALL supported system. Be warned, this will take a while. You can
4148 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4149 environment variable to the script, i. e. to use the ELDK cross tools
4152 CROSS_COMPILE=ppc_8xx- MAKEALL
4154 or to build on a native PowerPC system you can type
4156 CROSS_COMPILE=' ' MAKEALL
4158 When using the MAKEALL script, the default behaviour is to build
4159 U-Boot in the source directory. This location can be changed by
4160 setting the BUILD_DIR environment variable. Also, for each target
4161 built, the MAKEALL script saves two log files (<target>.ERR and
4162 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4163 location can be changed by setting the MAKEALL_LOGDIR environment
4164 variable. For example:
4166 export BUILD_DIR=/tmp/build
4167 export MAKEALL_LOGDIR=/tmp/log
4168 CROSS_COMPILE=ppc_8xx- MAKEALL
4170 With the above settings build objects are saved in the /tmp/build,
4171 log files are saved in the /tmp/log and the source tree remains clean
4172 during the whole build process.
4175 See also "U-Boot Porting Guide" below.
4178 Monitor Commands - Overview:
4179 ============================
4181 go - start application at address 'addr'
4182 run - run commands in an environment variable
4183 bootm - boot application image from memory
4184 bootp - boot image via network using BootP/TFTP protocol
4185 bootz - boot zImage from memory
4186 tftpboot- boot image via network using TFTP protocol
4187 and env variables "ipaddr" and "serverip"
4188 (and eventually "gatewayip")
4189 tftpput - upload a file via network using TFTP protocol
4190 rarpboot- boot image via network using RARP/TFTP protocol
4191 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4192 loads - load S-Record file over serial line
4193 loadb - load binary file over serial line (kermit mode)
4195 mm - memory modify (auto-incrementing)
4196 nm - memory modify (constant address)
4197 mw - memory write (fill)
4199 cmp - memory compare
4200 crc32 - checksum calculation
4201 i2c - I2C sub-system
4202 sspi - SPI utility commands
4203 base - print or set address offset
4204 printenv- print environment variables
4205 setenv - set environment variables
4206 saveenv - save environment variables to persistent storage
4207 protect - enable or disable FLASH write protection
4208 erase - erase FLASH memory
4209 flinfo - print FLASH memory information
4210 nand - NAND memory operations (see doc/README.nand)
4211 bdinfo - print Board Info structure
4212 iminfo - print header information for application image
4213 coninfo - print console devices and informations
4214 ide - IDE sub-system
4215 loop - infinite loop on address range
4216 loopw - infinite write loop on address range
4217 mtest - simple RAM test
4218 icache - enable or disable instruction cache
4219 dcache - enable or disable data cache
4220 reset - Perform RESET of the CPU
4221 echo - echo args to console
4222 version - print monitor version
4223 help - print online help
4224 ? - alias for 'help'
4227 Monitor Commands - Detailed Description:
4228 ========================================
4232 For now: just type "help <command>".
4235 Environment Variables:
4236 ======================
4238 U-Boot supports user configuration using Environment Variables which
4239 can be made persistent by saving to Flash memory.
4241 Environment Variables are set using "setenv", printed using
4242 "printenv", and saved to Flash using "saveenv". Using "setenv"
4243 without a value can be used to delete a variable from the
4244 environment. As long as you don't save the environment you are
4245 working with an in-memory copy. In case the Flash area containing the
4246 environment is erased by accident, a default environment is provided.
4248 Some configuration options can be set using Environment Variables.
4250 List of environment variables (most likely not complete):
4252 baudrate - see CONFIG_BAUDRATE
4254 bootdelay - see CONFIG_BOOTDELAY
4256 bootcmd - see CONFIG_BOOTCOMMAND
4258 bootargs - Boot arguments when booting an RTOS image
4260 bootfile - Name of the image to load with TFTP
4262 bootm_low - Memory range available for image processing in the bootm
4263 command can be restricted. This variable is given as
4264 a hexadecimal number and defines lowest address allowed
4265 for use by the bootm command. See also "bootm_size"
4266 environment variable. Address defined by "bootm_low" is
4267 also the base of the initial memory mapping for the Linux
4268 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4271 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4272 This variable is given as a hexadecimal number and it
4273 defines the size of the memory region starting at base
4274 address bootm_low that is accessible by the Linux kernel
4275 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4276 as the default value if it is defined, and bootm_size is
4279 bootm_size - Memory range available for image processing in the bootm
4280 command can be restricted. This variable is given as
4281 a hexadecimal number and defines the size of the region
4282 allowed for use by the bootm command. See also "bootm_low"
4283 environment variable.
4285 updatefile - Location of the software update file on a TFTP server, used
4286 by the automatic software update feature. Please refer to
4287 documentation in doc/README.update for more details.
4289 autoload - if set to "no" (any string beginning with 'n'),
4290 "bootp" will just load perform a lookup of the
4291 configuration from the BOOTP server, but not try to
4292 load any image using TFTP
4294 autostart - if set to "yes", an image loaded using the "bootp",
4295 "rarpboot", "tftpboot" or "diskboot" commands will
4296 be automatically started (by internally calling
4299 If set to "no", a standalone image passed to the
4300 "bootm" command will be copied to the load address
4301 (and eventually uncompressed), but NOT be started.
4302 This can be used to load and uncompress arbitrary
4305 fdt_high - if set this restricts the maximum address that the
4306 flattened device tree will be copied into upon boot.
4307 For example, if you have a system with 1 GB memory
4308 at physical address 0x10000000, while Linux kernel
4309 only recognizes the first 704 MB as low memory, you
4310 may need to set fdt_high as 0x3C000000 to have the
4311 device tree blob be copied to the maximum address
4312 of the 704 MB low memory, so that Linux kernel can
4313 access it during the boot procedure.
4315 If this is set to the special value 0xFFFFFFFF then
4316 the fdt will not be copied at all on boot. For this
4317 to work it must reside in writable memory, have
4318 sufficient padding on the end of it for u-boot to
4319 add the information it needs into it, and the memory
4320 must be accessible by the kernel.
4322 fdtcontroladdr- if set this is the address of the control flattened
4323 device tree used by U-Boot when CONFIG_OF_CONTROL is
4326 i2cfast - (PPC405GP|PPC405EP only)
4327 if set to 'y' configures Linux I2C driver for fast
4328 mode (400kHZ). This environment variable is used in
4329 initialization code. So, for changes to be effective
4330 it must be saved and board must be reset.
4332 initrd_high - restrict positioning of initrd images:
4333 If this variable is not set, initrd images will be
4334 copied to the highest possible address in RAM; this
4335 is usually what you want since it allows for
4336 maximum initrd size. If for some reason you want to
4337 make sure that the initrd image is loaded below the
4338 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4339 variable to a value of "no" or "off" or "0".
4340 Alternatively, you can set it to a maximum upper
4341 address to use (U-Boot will still check that it
4342 does not overwrite the U-Boot stack and data).
4344 For instance, when you have a system with 16 MB
4345 RAM, and want to reserve 4 MB from use by Linux,
4346 you can do this by adding "mem=12M" to the value of
4347 the "bootargs" variable. However, now you must make
4348 sure that the initrd image is placed in the first
4349 12 MB as well - this can be done with
4351 setenv initrd_high 00c00000
4353 If you set initrd_high to 0xFFFFFFFF, this is an
4354 indication to U-Boot that all addresses are legal
4355 for the Linux kernel, including addresses in flash
4356 memory. In this case U-Boot will NOT COPY the
4357 ramdisk at all. This may be useful to reduce the
4358 boot time on your system, but requires that this
4359 feature is supported by your Linux kernel.
4361 ipaddr - IP address; needed for tftpboot command
4363 loadaddr - Default load address for commands like "bootp",
4364 "rarpboot", "tftpboot", "loadb" or "diskboot"
4366 loads_echo - see CONFIG_LOADS_ECHO
4368 serverip - TFTP server IP address; needed for tftpboot command
4370 bootretry - see CONFIG_BOOT_RETRY_TIME
4372 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4374 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4376 ethprime - controls which interface is used first.
4378 ethact - controls which interface is currently active.
4379 For example you can do the following
4381 => setenv ethact FEC
4382 => ping 192.168.0.1 # traffic sent on FEC
4383 => setenv ethact SCC
4384 => ping 10.0.0.1 # traffic sent on SCC
4386 ethrotate - When set to "no" U-Boot does not go through all
4387 available network interfaces.
4388 It just stays at the currently selected interface.
4390 netretry - When set to "no" each network operation will
4391 either succeed or fail without retrying.
4392 When set to "once" the network operation will
4393 fail when all the available network interfaces
4394 are tried once without success.
4395 Useful on scripts which control the retry operation
4398 npe_ucode - set load address for the NPE microcode
4400 tftpsrcport - If this is set, the value is used for TFTP's
4403 tftpdstport - If this is set, the value is used for TFTP's UDP
4404 destination port instead of the Well Know Port 69.
4406 tftpblocksize - Block size to use for TFTP transfers; if not set,
4407 we use the TFTP server's default block size
4409 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4410 seconds, minimum value is 1000 = 1 second). Defines
4411 when a packet is considered to be lost so it has to
4412 be retransmitted. The default is 5000 = 5 seconds.
4413 Lowering this value may make downloads succeed
4414 faster in networks with high packet loss rates or
4415 with unreliable TFTP servers.
4417 vlan - When set to a value < 4095 the traffic over
4418 Ethernet is encapsulated/received over 802.1q
4421 The following image location variables contain the location of images
4422 used in booting. The "Image" column gives the role of the image and is
4423 not an environment variable name. The other columns are environment
4424 variable names. "File Name" gives the name of the file on a TFTP
4425 server, "RAM Address" gives the location in RAM the image will be
4426 loaded to, and "Flash Location" gives the image's address in NOR
4427 flash or offset in NAND flash.
4429 *Note* - these variables don't have to be defined for all boards, some
4430 boards currenlty use other variables for these purposes, and some
4431 boards use these variables for other purposes.
4433 Image File Name RAM Address Flash Location
4434 ----- --------- ----------- --------------
4435 u-boot u-boot u-boot_addr_r u-boot_addr
4436 Linux kernel bootfile kernel_addr_r kernel_addr
4437 device tree blob fdtfile fdt_addr_r fdt_addr
4438 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4440 The following environment variables may be used and automatically
4441 updated by the network boot commands ("bootp" and "rarpboot"),
4442 depending the information provided by your boot server:
4444 bootfile - see above
4445 dnsip - IP address of your Domain Name Server
4446 dnsip2 - IP address of your secondary Domain Name Server
4447 gatewayip - IP address of the Gateway (Router) to use
4448 hostname - Target hostname
4450 netmask - Subnet Mask
4451 rootpath - Pathname of the root filesystem on the NFS server
4452 serverip - see above
4455 There are two special Environment Variables:
4457 serial# - contains hardware identification information such
4458 as type string and/or serial number
4459 ethaddr - Ethernet address
4461 These variables can be set only once (usually during manufacturing of
4462 the board). U-Boot refuses to delete or overwrite these variables
4463 once they have been set once.
4466 Further special Environment Variables:
4468 ver - Contains the U-Boot version string as printed
4469 with the "version" command. This variable is
4470 readonly (see CONFIG_VERSION_VARIABLE).
4473 Please note that changes to some configuration parameters may take
4474 only effect after the next boot (yes, that's just like Windoze :-).
4477 Callback functions for environment variables:
4478 ---------------------------------------------
4480 For some environment variables, the behavior of u-boot needs to change
4481 when their values are changed. This functionailty allows functions to
4482 be associated with arbitrary variables. On creation, overwrite, or
4483 deletion, the callback will provide the opportunity for some side
4484 effect to happen or for the change to be rejected.
4486 The callbacks are named and associated with a function using the
4487 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4489 These callbacks are associated with variables in one of two ways. The
4490 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4491 in the board configuration to a string that defines a list of
4492 associations. The list must be in the following format:
4494 entry = variable_name[:callback_name]
4497 If the callback name is not specified, then the callback is deleted.
4498 Spaces are also allowed anywhere in the list.
4500 Callbacks can also be associated by defining the ".callbacks" variable
4501 with the same list format above. Any association in ".callbacks" will
4502 override any association in the static list. You can define
4503 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4504 ".callbacks" envirnoment variable in the default or embedded environment.
4507 Command Line Parsing:
4508 =====================
4510 There are two different command line parsers available with U-Boot:
4511 the old "simple" one, and the much more powerful "hush" shell:
4513 Old, simple command line parser:
4514 --------------------------------
4516 - supports environment variables (through setenv / saveenv commands)
4517 - several commands on one line, separated by ';'
4518 - variable substitution using "... ${name} ..." syntax
4519 - special characters ('$', ';') can be escaped by prefixing with '\',
4521 setenv bootcmd bootm \${address}
4522 - You can also escape text by enclosing in single apostrophes, for example:
4523 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4528 - similar to Bourne shell, with control structures like
4529 if...then...else...fi, for...do...done; while...do...done,
4530 until...do...done, ...
4531 - supports environment ("global") variables (through setenv / saveenv
4532 commands) and local shell variables (through standard shell syntax
4533 "name=value"); only environment variables can be used with "run"
4539 (1) If a command line (or an environment variable executed by a "run"
4540 command) contains several commands separated by semicolon, and
4541 one of these commands fails, then the remaining commands will be
4544 (2) If you execute several variables with one call to run (i. e.
4545 calling run with a list of variables as arguments), any failing
4546 command will cause "run" to terminate, i. e. the remaining
4547 variables are not executed.
4549 Note for Redundant Ethernet Interfaces:
4550 =======================================
4552 Some boards come with redundant Ethernet interfaces; U-Boot supports
4553 such configurations and is capable of automatic selection of a
4554 "working" interface when needed. MAC assignment works as follows:
4556 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4557 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4558 "eth1addr" (=>eth1), "eth2addr", ...
4560 If the network interface stores some valid MAC address (for instance
4561 in SROM), this is used as default address if there is NO correspon-
4562 ding setting in the environment; if the corresponding environment
4563 variable is set, this overrides the settings in the card; that means:
4565 o If the SROM has a valid MAC address, and there is no address in the
4566 environment, the SROM's address is used.
4568 o If there is no valid address in the SROM, and a definition in the
4569 environment exists, then the value from the environment variable is
4572 o If both the SROM and the environment contain a MAC address, and
4573 both addresses are the same, this MAC address is used.
4575 o If both the SROM and the environment contain a MAC address, and the
4576 addresses differ, the value from the environment is used and a
4579 o If neither SROM nor the environment contain a MAC address, an error
4582 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4583 will be programmed into hardware as part of the initialization process. This
4584 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4585 The naming convention is as follows:
4586 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4591 U-Boot is capable of booting (and performing other auxiliary operations on)
4592 images in two formats:
4594 New uImage format (FIT)
4595 -----------------------
4597 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4598 to Flattened Device Tree). It allows the use of images with multiple
4599 components (several kernels, ramdisks, etc.), with contents protected by
4600 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4606 Old image format is based on binary files which can be basically anything,
4607 preceded by a special header; see the definitions in include/image.h for
4608 details; basically, the header defines the following image properties:
4610 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4611 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4612 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4613 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4615 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4616 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4617 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4618 * Compression Type (uncompressed, gzip, bzip2)
4624 The header is marked by a special Magic Number, and both the header
4625 and the data portions of the image are secured against corruption by
4632 Although U-Boot should support any OS or standalone application
4633 easily, the main focus has always been on Linux during the design of
4636 U-Boot includes many features that so far have been part of some
4637 special "boot loader" code within the Linux kernel. Also, any
4638 "initrd" images to be used are no longer part of one big Linux image;
4639 instead, kernel and "initrd" are separate images. This implementation
4640 serves several purposes:
4642 - the same features can be used for other OS or standalone
4643 applications (for instance: using compressed images to reduce the
4644 Flash memory footprint)
4646 - it becomes much easier to port new Linux kernel versions because
4647 lots of low-level, hardware dependent stuff are done by U-Boot
4649 - the same Linux kernel image can now be used with different "initrd"
4650 images; of course this also means that different kernel images can
4651 be run with the same "initrd". This makes testing easier (you don't
4652 have to build a new "zImage.initrd" Linux image when you just
4653 change a file in your "initrd"). Also, a field-upgrade of the
4654 software is easier now.
4660 Porting Linux to U-Boot based systems:
4661 ---------------------------------------
4663 U-Boot cannot save you from doing all the necessary modifications to
4664 configure the Linux device drivers for use with your target hardware
4665 (no, we don't intend to provide a full virtual machine interface to
4668 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4670 Just make sure your machine specific header file (for instance
4671 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4672 Information structure as we define in include/asm-<arch>/u-boot.h,
4673 and make sure that your definition of IMAP_ADDR uses the same value
4674 as your U-Boot configuration in CONFIG_SYS_IMMR.
4677 Configuring the Linux kernel:
4678 -----------------------------
4680 No specific requirements for U-Boot. Make sure you have some root
4681 device (initial ramdisk, NFS) for your target system.
4684 Building a Linux Image:
4685 -----------------------
4687 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4688 not used. If you use recent kernel source, a new build target
4689 "uImage" will exist which automatically builds an image usable by
4690 U-Boot. Most older kernels also have support for a "pImage" target,
4691 which was introduced for our predecessor project PPCBoot and uses a
4692 100% compatible format.
4701 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4702 encapsulate a compressed Linux kernel image with header information,
4703 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4705 * build a standard "vmlinux" kernel image (in ELF binary format):
4707 * convert the kernel into a raw binary image:
4709 ${CROSS_COMPILE}-objcopy -O binary \
4710 -R .note -R .comment \
4711 -S vmlinux linux.bin
4713 * compress the binary image:
4717 * package compressed binary image for U-Boot:
4719 mkimage -A ppc -O linux -T kernel -C gzip \
4720 -a 0 -e 0 -n "Linux Kernel Image" \
4721 -d linux.bin.gz uImage
4724 The "mkimage" tool can also be used to create ramdisk images for use
4725 with U-Boot, either separated from the Linux kernel image, or
4726 combined into one file. "mkimage" encapsulates the images with a 64
4727 byte header containing information about target architecture,
4728 operating system, image type, compression method, entry points, time
4729 stamp, CRC32 checksums, etc.
4731 "mkimage" can be called in two ways: to verify existing images and
4732 print the header information, or to build new images.
4734 In the first form (with "-l" option) mkimage lists the information
4735 contained in the header of an existing U-Boot image; this includes
4736 checksum verification:
4738 tools/mkimage -l image
4739 -l ==> list image header information
4741 The second form (with "-d" option) is used to build a U-Boot image
4742 from a "data file" which is used as image payload:
4744 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4745 -n name -d data_file image
4746 -A ==> set architecture to 'arch'
4747 -O ==> set operating system to 'os'
4748 -T ==> set image type to 'type'
4749 -C ==> set compression type 'comp'
4750 -a ==> set load address to 'addr' (hex)
4751 -e ==> set entry point to 'ep' (hex)
4752 -n ==> set image name to 'name'
4753 -d ==> use image data from 'datafile'
4755 Right now, all Linux kernels for PowerPC systems use the same load
4756 address (0x00000000), but the entry point address depends on the
4759 - 2.2.x kernels have the entry point at 0x0000000C,
4760 - 2.3.x and later kernels have the entry point at 0x00000000.
4762 So a typical call to build a U-Boot image would read:
4764 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4765 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4766 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4767 > examples/uImage.TQM850L
4768 Image Name: 2.4.4 kernel for TQM850L
4769 Created: Wed Jul 19 02:34:59 2000
4770 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4771 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4772 Load Address: 0x00000000
4773 Entry Point: 0x00000000
4775 To verify the contents of the image (or check for corruption):
4777 -> tools/mkimage -l examples/uImage.TQM850L
4778 Image Name: 2.4.4 kernel for TQM850L
4779 Created: Wed Jul 19 02:34:59 2000
4780 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4781 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4782 Load Address: 0x00000000
4783 Entry Point: 0x00000000
4785 NOTE: for embedded systems where boot time is critical you can trade
4786 speed for memory and install an UNCOMPRESSED image instead: this
4787 needs more space in Flash, but boots much faster since it does not
4788 need to be uncompressed:
4790 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4791 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4792 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4793 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4794 > examples/uImage.TQM850L-uncompressed
4795 Image Name: 2.4.4 kernel for TQM850L
4796 Created: Wed Jul 19 02:34:59 2000
4797 Image Type: PowerPC Linux Kernel Image (uncompressed)
4798 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4799 Load Address: 0x00000000
4800 Entry Point: 0x00000000
4803 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4804 when your kernel is intended to use an initial ramdisk:
4806 -> tools/mkimage -n 'Simple Ramdisk Image' \
4807 > -A ppc -O linux -T ramdisk -C gzip \
4808 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4809 Image Name: Simple Ramdisk Image
4810 Created: Wed Jan 12 14:01:50 2000
4811 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4812 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4813 Load Address: 0x00000000
4814 Entry Point: 0x00000000
4817 Installing a Linux Image:
4818 -------------------------
4820 To downloading a U-Boot image over the serial (console) interface,
4821 you must convert the image to S-Record format:
4823 objcopy -I binary -O srec examples/image examples/image.srec
4825 The 'objcopy' does not understand the information in the U-Boot
4826 image header, so the resulting S-Record file will be relative to
4827 address 0x00000000. To load it to a given address, you need to
4828 specify the target address as 'offset' parameter with the 'loads'
4831 Example: install the image to address 0x40100000 (which on the
4832 TQM8xxL is in the first Flash bank):
4834 => erase 40100000 401FFFFF
4840 ## Ready for S-Record download ...
4841 ~>examples/image.srec
4842 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4844 15989 15990 15991 15992
4845 [file transfer complete]
4847 ## Start Addr = 0x00000000
4850 You can check the success of the download using the 'iminfo' command;
4851 this includes a checksum verification so you can be sure no data
4852 corruption happened:
4856 ## Checking Image at 40100000 ...
4857 Image Name: 2.2.13 for initrd on TQM850L
4858 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4859 Data Size: 335725 Bytes = 327 kB = 0 MB
4860 Load Address: 00000000
4861 Entry Point: 0000000c
4862 Verifying Checksum ... OK
4868 The "bootm" command is used to boot an application that is stored in
4869 memory (RAM or Flash). In case of a Linux kernel image, the contents
4870 of the "bootargs" environment variable is passed to the kernel as
4871 parameters. You can check and modify this variable using the
4872 "printenv" and "setenv" commands:
4875 => printenv bootargs
4876 bootargs=root=/dev/ram
4878 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4880 => printenv bootargs
4881 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4884 ## Booting Linux kernel at 40020000 ...
4885 Image Name: 2.2.13 for NFS on TQM850L
4886 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4887 Data Size: 381681 Bytes = 372 kB = 0 MB
4888 Load Address: 00000000
4889 Entry Point: 0000000c
4890 Verifying Checksum ... OK
4891 Uncompressing Kernel Image ... OK
4892 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
4893 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4894 time_init: decrementer frequency = 187500000/60
4895 Calibrating delay loop... 49.77 BogoMIPS
4896 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4899 If you want to boot a Linux kernel with initial RAM disk, you pass
4900 the memory addresses of both the kernel and the initrd image (PPBCOOT
4901 format!) to the "bootm" command:
4903 => imi 40100000 40200000
4905 ## Checking Image at 40100000 ...
4906 Image Name: 2.2.13 for initrd on TQM850L
4907 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4908 Data Size: 335725 Bytes = 327 kB = 0 MB
4909 Load Address: 00000000
4910 Entry Point: 0000000c
4911 Verifying Checksum ... OK
4913 ## Checking Image at 40200000 ...
4914 Image Name: Simple Ramdisk Image
4915 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4916 Data Size: 566530 Bytes = 553 kB = 0 MB
4917 Load Address: 00000000
4918 Entry Point: 00000000
4919 Verifying Checksum ... OK
4921 => bootm 40100000 40200000
4922 ## Booting Linux kernel at 40100000 ...
4923 Image Name: 2.2.13 for initrd on TQM850L
4924 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4925 Data Size: 335725 Bytes = 327 kB = 0 MB
4926 Load Address: 00000000
4927 Entry Point: 0000000c
4928 Verifying Checksum ... OK
4929 Uncompressing Kernel Image ... OK
4930 ## Loading RAMDisk Image at 40200000 ...
4931 Image Name: Simple Ramdisk Image
4932 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4933 Data Size: 566530 Bytes = 553 kB = 0 MB
4934 Load Address: 00000000
4935 Entry Point: 00000000
4936 Verifying Checksum ... OK
4937 Loading Ramdisk ... OK
4938 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
4939 Boot arguments: root=/dev/ram
4940 time_init: decrementer frequency = 187500000/60
4941 Calibrating delay loop... 49.77 BogoMIPS
4943 RAMDISK: Compressed image found at block 0
4944 VFS: Mounted root (ext2 filesystem).
4948 Boot Linux and pass a flat device tree:
4951 First, U-Boot must be compiled with the appropriate defines. See the section
4952 titled "Linux Kernel Interface" above for a more in depth explanation. The
4953 following is an example of how to start a kernel and pass an updated
4959 oft=oftrees/mpc8540ads.dtb
4960 => tftp $oftaddr $oft
4961 Speed: 1000, full duplex
4963 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4964 Filename 'oftrees/mpc8540ads.dtb'.
4965 Load address: 0x300000
4968 Bytes transferred = 4106 (100a hex)
4969 => tftp $loadaddr $bootfile
4970 Speed: 1000, full duplex
4972 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4974 Load address: 0x200000
4975 Loading:############
4977 Bytes transferred = 1029407 (fb51f hex)
4982 => bootm $loadaddr - $oftaddr
4983 ## Booting image at 00200000 ...
4984 Image Name: Linux-2.6.17-dirty
4985 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4986 Data Size: 1029343 Bytes = 1005.2 kB
4987 Load Address: 00000000
4988 Entry Point: 00000000
4989 Verifying Checksum ... OK
4990 Uncompressing Kernel Image ... OK
4991 Booting using flat device tree at 0x300000
4992 Using MPC85xx ADS machine description
4993 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4997 More About U-Boot Image Types:
4998 ------------------------------
5000 U-Boot supports the following image types:
5002 "Standalone Programs" are directly runnable in the environment
5003 provided by U-Boot; it is expected that (if they behave
5004 well) you can continue to work in U-Boot after return from
5005 the Standalone Program.
5006 "OS Kernel Images" are usually images of some Embedded OS which
5007 will take over control completely. Usually these programs
5008 will install their own set of exception handlers, device
5009 drivers, set up the MMU, etc. - this means, that you cannot
5010 expect to re-enter U-Boot except by resetting the CPU.
5011 "RAMDisk Images" are more or less just data blocks, and their
5012 parameters (address, size) are passed to an OS kernel that is
5014 "Multi-File Images" contain several images, typically an OS
5015 (Linux) kernel image and one or more data images like
5016 RAMDisks. This construct is useful for instance when you want
5017 to boot over the network using BOOTP etc., where the boot
5018 server provides just a single image file, but you want to get
5019 for instance an OS kernel and a RAMDisk image.
5021 "Multi-File Images" start with a list of image sizes, each
5022 image size (in bytes) specified by an "uint32_t" in network
5023 byte order. This list is terminated by an "(uint32_t)0".
5024 Immediately after the terminating 0 follow the images, one by
5025 one, all aligned on "uint32_t" boundaries (size rounded up to
5026 a multiple of 4 bytes).
5028 "Firmware Images" are binary images containing firmware (like
5029 U-Boot or FPGA images) which usually will be programmed to
5032 "Script files" are command sequences that will be executed by
5033 U-Boot's command interpreter; this feature is especially
5034 useful when you configure U-Boot to use a real shell (hush)
5035 as command interpreter.
5037 Booting the Linux zImage:
5038 -------------------------
5040 On some platforms, it's possible to boot Linux zImage. This is done
5041 using the "bootz" command. The syntax of "bootz" command is the same
5042 as the syntax of "bootm" command.
5044 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
5045 kernel with raw initrd images. The syntax is slightly different, the
5046 address of the initrd must be augmented by it's size, in the following
5047 format: "<initrd addres>:<initrd size>".
5053 One of the features of U-Boot is that you can dynamically load and
5054 run "standalone" applications, which can use some resources of
5055 U-Boot like console I/O functions or interrupt services.
5057 Two simple examples are included with the sources:
5062 'examples/hello_world.c' contains a small "Hello World" Demo
5063 application; it is automatically compiled when you build U-Boot.
5064 It's configured to run at address 0x00040004, so you can play with it
5068 ## Ready for S-Record download ...
5069 ~>examples/hello_world.srec
5070 1 2 3 4 5 6 7 8 9 10 11 ...
5071 [file transfer complete]
5073 ## Start Addr = 0x00040004
5075 => go 40004 Hello World! This is a test.
5076 ## Starting application at 0x00040004 ...
5087 Hit any key to exit ...
5089 ## Application terminated, rc = 0x0
5091 Another example, which demonstrates how to register a CPM interrupt
5092 handler with the U-Boot code, can be found in 'examples/timer.c'.
5093 Here, a CPM timer is set up to generate an interrupt every second.
5094 The interrupt service routine is trivial, just printing a '.'
5095 character, but this is just a demo program. The application can be
5096 controlled by the following keys:
5098 ? - print current values og the CPM Timer registers
5099 b - enable interrupts and start timer
5100 e - stop timer and disable interrupts
5101 q - quit application
5104 ## Ready for S-Record download ...
5105 ~>examples/timer.srec
5106 1 2 3 4 5 6 7 8 9 10 11 ...
5107 [file transfer complete]
5109 ## Start Addr = 0x00040004
5112 ## Starting application at 0x00040004 ...
5115 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5118 [q, b, e, ?] Set interval 1000000 us
5121 [q, b, e, ?] ........
5122 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5125 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5128 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5131 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5133 [q, b, e, ?] ...Stopping timer
5135 [q, b, e, ?] ## Application terminated, rc = 0x0
5141 Over time, many people have reported problems when trying to use the
5142 "minicom" terminal emulation program for serial download. I (wd)
5143 consider minicom to be broken, and recommend not to use it. Under
5144 Unix, I recommend to use C-Kermit for general purpose use (and
5145 especially for kermit binary protocol download ("loadb" command), and
5146 use "cu" for S-Record download ("loads" command). See
5147 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5148 for help with kermit.
5151 Nevertheless, if you absolutely want to use it try adding this
5152 configuration to your "File transfer protocols" section:
5154 Name Program Name U/D FullScr IO-Red. Multi
5155 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5156 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5162 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5163 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5165 Building requires a cross environment; it is known to work on
5166 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5167 need gmake since the Makefiles are not compatible with BSD make).
5168 Note that the cross-powerpc package does not install include files;
5169 attempting to build U-Boot will fail because <machine/ansi.h> is
5170 missing. This file has to be installed and patched manually:
5172 # cd /usr/pkg/cross/powerpc-netbsd/include
5174 # ln -s powerpc machine
5175 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5176 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5178 Native builds *don't* work due to incompatibilities between native
5179 and U-Boot include files.
5181 Booting assumes that (the first part of) the image booted is a
5182 stage-2 loader which in turn loads and then invokes the kernel
5183 proper. Loader sources will eventually appear in the NetBSD source
5184 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5185 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5188 Implementation Internals:
5189 =========================
5191 The following is not intended to be a complete description of every
5192 implementation detail. However, it should help to understand the
5193 inner workings of U-Boot and make it easier to port it to custom
5197 Initial Stack, Global Data:
5198 ---------------------------
5200 The implementation of U-Boot is complicated by the fact that U-Boot
5201 starts running out of ROM (flash memory), usually without access to
5202 system RAM (because the memory controller is not initialized yet).
5203 This means that we don't have writable Data or BSS segments, and BSS
5204 is not initialized as zero. To be able to get a C environment working
5205 at all, we have to allocate at least a minimal stack. Implementation
5206 options for this are defined and restricted by the CPU used: Some CPU
5207 models provide on-chip memory (like the IMMR area on MPC8xx and
5208 MPC826x processors), on others (parts of) the data cache can be
5209 locked as (mis-) used as memory, etc.
5211 Chris Hallinan posted a good summary of these issues to the
5212 U-Boot mailing list:
5214 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5215 From: "Chris Hallinan" <clh@net1plus.com>
5216 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5219 Correct me if I'm wrong, folks, but the way I understand it
5220 is this: Using DCACHE as initial RAM for Stack, etc, does not
5221 require any physical RAM backing up the cache. The cleverness
5222 is that the cache is being used as a temporary supply of
5223 necessary storage before the SDRAM controller is setup. It's
5224 beyond the scope of this list to explain the details, but you
5225 can see how this works by studying the cache architecture and
5226 operation in the architecture and processor-specific manuals.
5228 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5229 is another option for the system designer to use as an
5230 initial stack/RAM area prior to SDRAM being available. Either
5231 option should work for you. Using CS 4 should be fine if your
5232 board designers haven't used it for something that would
5233 cause you grief during the initial boot! It is frequently not
5236 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5237 with your processor/board/system design. The default value
5238 you will find in any recent u-boot distribution in
5239 walnut.h should work for you. I'd set it to a value larger
5240 than your SDRAM module. If you have a 64MB SDRAM module, set
5241 it above 400_0000. Just make sure your board has no resources
5242 that are supposed to respond to that address! That code in
5243 start.S has been around a while and should work as is when
5244 you get the config right.
5249 It is essential to remember this, since it has some impact on the C
5250 code for the initialization procedures:
5252 * Initialized global data (data segment) is read-only. Do not attempt
5255 * Do not use any uninitialized global data (or implicitely initialized
5256 as zero data - BSS segment) at all - this is undefined, initiali-
5257 zation is performed later (when relocating to RAM).
5259 * Stack space is very limited. Avoid big data buffers or things like
5262 Having only the stack as writable memory limits means we cannot use
5263 normal global data to share information beween the code. But it
5264 turned out that the implementation of U-Boot can be greatly
5265 simplified by making a global data structure (gd_t) available to all
5266 functions. We could pass a pointer to this data as argument to _all_
5267 functions, but this would bloat the code. Instead we use a feature of
5268 the GCC compiler (Global Register Variables) to share the data: we
5269 place a pointer (gd) to the global data into a register which we
5270 reserve for this purpose.
5272 When choosing a register for such a purpose we are restricted by the
5273 relevant (E)ABI specifications for the current architecture, and by
5274 GCC's implementation.
5276 For PowerPC, the following registers have specific use:
5278 R2: reserved for system use
5279 R3-R4: parameter passing and return values
5280 R5-R10: parameter passing
5281 R13: small data area pointer
5285 (U-Boot also uses R12 as internal GOT pointer. r12
5286 is a volatile register so r12 needs to be reset when
5287 going back and forth between asm and C)
5289 ==> U-Boot will use R2 to hold a pointer to the global data
5291 Note: on PPC, we could use a static initializer (since the
5292 address of the global data structure is known at compile time),
5293 but it turned out that reserving a register results in somewhat
5294 smaller code - although the code savings are not that big (on
5295 average for all boards 752 bytes for the whole U-Boot image,
5296 624 text + 127 data).
5298 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5299 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5301 ==> U-Boot will use P3 to hold a pointer to the global data
5303 On ARM, the following registers are used:
5305 R0: function argument word/integer result
5306 R1-R3: function argument word
5308 R10: stack limit (used only if stack checking if enabled)
5309 R11: argument (frame) pointer
5310 R12: temporary workspace
5313 R15: program counter
5315 ==> U-Boot will use R8 to hold a pointer to the global data
5317 On Nios II, the ABI is documented here:
5318 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5320 ==> U-Boot will use gp to hold a pointer to the global data
5322 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5323 to access small data sections, so gp is free.
5325 On NDS32, the following registers are used:
5327 R0-R1: argument/return
5329 R15: temporary register for assembler
5330 R16: trampoline register
5331 R28: frame pointer (FP)
5332 R29: global pointer (GP)
5333 R30: link register (LP)
5334 R31: stack pointer (SP)
5335 PC: program counter (PC)
5337 ==> U-Boot will use R10 to hold a pointer to the global data
5339 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5340 or current versions of GCC may "optimize" the code too much.
5345 U-Boot runs in system state and uses physical addresses, i.e. the
5346 MMU is not used either for address mapping nor for memory protection.
5348 The available memory is mapped to fixed addresses using the memory
5349 controller. In this process, a contiguous block is formed for each
5350 memory type (Flash, SDRAM, SRAM), even when it consists of several
5351 physical memory banks.
5353 U-Boot is installed in the first 128 kB of the first Flash bank (on
5354 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5355 booting and sizing and initializing DRAM, the code relocates itself
5356 to the upper end of DRAM. Immediately below the U-Boot code some
5357 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5358 configuration setting]. Below that, a structure with global Board
5359 Info data is placed, followed by the stack (growing downward).
5361 Additionally, some exception handler code is copied to the low 8 kB
5362 of DRAM (0x00000000 ... 0x00001FFF).
5364 So a typical memory configuration with 16 MB of DRAM could look like
5367 0x0000 0000 Exception Vector code
5370 0x0000 2000 Free for Application Use
5376 0x00FB FF20 Monitor Stack (Growing downward)
5377 0x00FB FFAC Board Info Data and permanent copy of global data
5378 0x00FC 0000 Malloc Arena
5381 0x00FE 0000 RAM Copy of Monitor Code
5382 ... eventually: LCD or video framebuffer
5383 ... eventually: pRAM (Protected RAM - unchanged by reset)
5384 0x00FF FFFF [End of RAM]
5387 System Initialization:
5388 ----------------------
5390 In the reset configuration, U-Boot starts at the reset entry point
5391 (on most PowerPC systems at address 0x00000100). Because of the reset
5392 configuration for CS0# this is a mirror of the onboard Flash memory.
5393 To be able to re-map memory U-Boot then jumps to its link address.
5394 To be able to implement the initialization code in C, a (small!)
5395 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5396 which provide such a feature like MPC8xx or MPC8260), or in a locked
5397 part of the data cache. After that, U-Boot initializes the CPU core,
5398 the caches and the SIU.
5400 Next, all (potentially) available memory banks are mapped using a
5401 preliminary mapping. For example, we put them on 512 MB boundaries
5402 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5403 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5404 programmed for SDRAM access. Using the temporary configuration, a
5405 simple memory test is run that determines the size of the SDRAM
5408 When there is more than one SDRAM bank, and the banks are of
5409 different size, the largest is mapped first. For equal size, the first
5410 bank (CS2#) is mapped first. The first mapping is always for address
5411 0x00000000, with any additional banks following immediately to create
5412 contiguous memory starting from 0.
5414 Then, the monitor installs itself at the upper end of the SDRAM area
5415 and allocates memory for use by malloc() and for the global Board
5416 Info data; also, the exception vector code is copied to the low RAM
5417 pages, and the final stack is set up.
5419 Only after this relocation will you have a "normal" C environment;
5420 until that you are restricted in several ways, mostly because you are
5421 running from ROM, and because the code will have to be relocated to a
5425 U-Boot Porting Guide:
5426 ----------------------
5428 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5432 int main(int argc, char *argv[])
5434 sighandler_t no_more_time;
5436 signal(SIGALRM, no_more_time);
5437 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5439 if (available_money > available_manpower) {
5440 Pay consultant to port U-Boot;
5444 Download latest U-Boot source;
5446 Subscribe to u-boot mailing list;
5449 email("Hi, I am new to U-Boot, how do I get started?");
5452 Read the README file in the top level directory;
5453 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5454 Read applicable doc/*.README;
5455 Read the source, Luke;
5456 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5459 if (available_money > toLocalCurrency ($2500))
5462 Add a lot of aggravation and time;
5464 if (a similar board exists) { /* hopefully... */
5465 cp -a board/<similar> board/<myboard>
5466 cp include/configs/<similar>.h include/configs/<myboard>.h
5468 Create your own board support subdirectory;
5469 Create your own board include/configs/<myboard>.h file;
5471 Edit new board/<myboard> files
5472 Edit new include/configs/<myboard>.h
5477 Add / modify source code;
5481 email("Hi, I am having problems...");
5483 Send patch file to the U-Boot email list;
5484 if (reasonable critiques)
5485 Incorporate improvements from email list code review;
5487 Defend code as written;
5493 void no_more_time (int sig)
5502 All contributions to U-Boot should conform to the Linux kernel
5503 coding style; see the file "Documentation/CodingStyle" and the script
5504 "scripts/Lindent" in your Linux kernel source directory.
5506 Source files originating from a different project (for example the
5507 MTD subsystem) are generally exempt from these guidelines and are not
5508 reformated to ease subsequent migration to newer versions of those
5511 Please note that U-Boot is implemented in C (and to some small parts in
5512 Assembler); no C++ is used, so please do not use C++ style comments (//)
5515 Please also stick to the following formatting rules:
5516 - remove any trailing white space
5517 - use TAB characters for indentation and vertical alignment, not spaces
5518 - make sure NOT to use DOS '\r\n' line feeds
5519 - do not add more than 2 consecutive empty lines to source files
5520 - do not add trailing empty lines to source files
5522 Submissions which do not conform to the standards may be returned
5523 with a request to reformat the changes.
5529 Since the number of patches for U-Boot is growing, we need to
5530 establish some rules. Submissions which do not conform to these rules
5531 may be rejected, even when they contain important and valuable stuff.
5533 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5535 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5536 see http://lists.denx.de/mailman/listinfo/u-boot
5538 When you send a patch, please include the following information with
5541 * For bug fixes: a description of the bug and how your patch fixes
5542 this bug. Please try to include a way of demonstrating that the
5543 patch actually fixes something.
5545 * For new features: a description of the feature and your
5548 * A CHANGELOG entry as plaintext (separate from the patch)
5550 * For major contributions, your entry to the CREDITS file
5552 * When you add support for a new board, don't forget to add this
5553 board to the MAINTAINERS file, too.
5555 * If your patch adds new configuration options, don't forget to
5556 document these in the README file.
5558 * The patch itself. If you are using git (which is *strongly*
5559 recommended) you can easily generate the patch using the
5560 "git format-patch". If you then use "git send-email" to send it to
5561 the U-Boot mailing list, you will avoid most of the common problems
5562 with some other mail clients.
5564 If you cannot use git, use "diff -purN OLD NEW". If your version of
5565 diff does not support these options, then get the latest version of
5568 The current directory when running this command shall be the parent
5569 directory of the U-Boot source tree (i. e. please make sure that
5570 your patch includes sufficient directory information for the
5573 We prefer patches as plain text. MIME attachments are discouraged,
5574 and compressed attachments must not be used.
5576 * If one logical set of modifications affects or creates several
5577 files, all these changes shall be submitted in a SINGLE patch file.
5579 * Changesets that contain different, unrelated modifications shall be
5580 submitted as SEPARATE patches, one patch per changeset.
5585 * Before sending the patch, run the MAKEALL script on your patched
5586 source tree and make sure that no errors or warnings are reported
5587 for any of the boards.
5589 * Keep your modifications to the necessary minimum: A patch
5590 containing several unrelated changes or arbitrary reformats will be
5591 returned with a request to re-formatting / split it.
5593 * If you modify existing code, make sure that your new code does not
5594 add to the memory footprint of the code ;-) Small is beautiful!
5595 When adding new features, these should compile conditionally only
5596 (using #ifdef), and the resulting code with the new feature
5597 disabled must not need more memory than the old code without your
5600 * Remember that there is a size limit of 100 kB per message on the
5601 u-boot mailing list. Bigger patches will be moderated. If they are
5602 reasonable and not too big, they will be acknowledged. But patches
5603 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob