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 - Linux Kernel Interface:
491 U-Boot stores all clock information in Hz
492 internally. For binary compatibility with older Linux
493 kernels (which expect the clocks passed in the
494 bd_info data to be in MHz) the environment variable
495 "clocks_in_mhz" can be defined so that U-Boot
496 converts clock data to MHZ before passing it to the
498 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
499 "clocks_in_mhz=1" is automatically included in the
502 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
504 When transferring memsize parameter to linux, some versions
505 expect it to be in bytes, others in MB.
506 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
510 New kernel versions are expecting firmware settings to be
511 passed using flattened device trees (based on open firmware
515 * New libfdt-based support
516 * Adds the "fdt" command
517 * The bootm command automatically updates the fdt
519 OF_CPU - The proper name of the cpus node (only required for
520 MPC512X and MPC5xxx based boards).
521 OF_SOC - The proper name of the soc node (only required for
522 MPC512X and MPC5xxx based boards).
523 OF_TBCLK - The timebase frequency.
524 OF_STDOUT_PATH - The path to the console device
526 boards with QUICC Engines require OF_QE to set UCC MAC
529 CONFIG_OF_BOARD_SETUP
531 Board code has addition modification that it wants to make
532 to the flat device tree before handing it off to the kernel
536 This define fills in the correct boot CPU in the boot
537 param header, the default value is zero if undefined.
541 U-Boot can detect if an IDE device is present or not.
542 If not, and this new config option is activated, U-Boot
543 removes the ATA node from the DTS before booting Linux,
544 so the Linux IDE driver does not probe the device and
545 crash. This is needed for buggy hardware (uc101) where
546 no pull down resistor is connected to the signal IDE5V_DD7.
548 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
550 This setting is mandatory for all boards that have only one
551 machine type and must be used to specify the machine type
552 number as it appears in the ARM machine registry
553 (see http://www.arm.linux.org.uk/developer/machines/).
554 Only boards that have multiple machine types supported
555 in a single configuration file and the machine type is
556 runtime discoverable, do not have to use this setting.
558 - vxWorks boot parameters:
560 bootvx constructs a valid bootline using the following
561 environments variables: bootfile, ipaddr, serverip, hostname.
562 It loads the vxWorks image pointed bootfile.
564 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
565 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
566 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
567 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
569 CONFIG_SYS_VXWORKS_ADD_PARAMS
571 Add it at the end of the bootline. E.g "u=username pw=secret"
573 Note: If a "bootargs" environment is defined, it will overwride
574 the defaults discussed just above.
576 - Cache Configuration:
577 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
578 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
579 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
581 - Cache Configuration for ARM:
582 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
584 CONFIG_SYS_PL310_BASE - Physical base address of PL310
585 controller register space
590 Define this if you want support for Amba PrimeCell PL010 UARTs.
594 Define this if you want support for Amba PrimeCell PL011 UARTs.
598 If you have Amba PrimeCell PL011 UARTs, set this variable to
599 the clock speed of the UARTs.
603 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
604 define this to a list of base addresses for each (supported)
605 port. See e.g. include/configs/versatile.h
607 CONFIG_PL011_SERIAL_RLCR
609 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
610 have separate receive and transmit line control registers. Set
611 this variable to initialize the extra register.
613 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
615 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
616 boot loader that has already initialized the UART. Define this
617 variable to flush the UART at init time.
621 Depending on board, define exactly one serial port
622 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
623 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
624 console by defining CONFIG_8xx_CONS_NONE
626 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
627 port routines must be defined elsewhere
628 (i.e. serial_init(), serial_getc(), ...)
631 Enables console device for a color framebuffer. Needs following
632 defines (cf. smiLynxEM, i8042)
633 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
635 VIDEO_HW_RECTFILL graphic chip supports
638 VIDEO_HW_BITBLT graphic chip supports
639 bit-blit (cf. smiLynxEM)
640 VIDEO_VISIBLE_COLS visible pixel columns
642 VIDEO_VISIBLE_ROWS visible pixel rows
643 VIDEO_PIXEL_SIZE bytes per pixel
644 VIDEO_DATA_FORMAT graphic data format
645 (0-5, cf. cfb_console.c)
646 VIDEO_FB_ADRS framebuffer address
647 VIDEO_KBD_INIT_FCT keyboard int fct
648 (i.e. i8042_kbd_init())
649 VIDEO_TSTC_FCT test char fct
651 VIDEO_GETC_FCT get char fct
653 CONFIG_CONSOLE_CURSOR cursor drawing on/off
654 (requires blink timer
656 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
657 CONFIG_CONSOLE_TIME display time/date info in
659 (requires CONFIG_CMD_DATE)
660 CONFIG_VIDEO_LOGO display Linux logo in
662 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
663 linux_logo.h for logo.
664 Requires CONFIG_VIDEO_LOGO
665 CONFIG_CONSOLE_EXTRA_INFO
666 additional board info beside
669 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
670 a limited number of ANSI escape sequences (cursor control,
671 erase functions and limited graphics rendition control).
673 When CONFIG_CFB_CONSOLE is defined, video console is
674 default i/o. Serial console can be forced with
675 environment 'console=serial'.
677 When CONFIG_SILENT_CONSOLE is defined, all console
678 messages (by U-Boot and Linux!) can be silenced with
679 the "silent" environment variable. See
680 doc/README.silent for more information.
683 CONFIG_BAUDRATE - in bps
684 Select one of the baudrates listed in
685 CONFIG_SYS_BAUDRATE_TABLE, see below.
686 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
688 - Console Rx buffer length
689 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
690 the maximum receive buffer length for the SMC.
691 This option is actual only for 82xx and 8xx possible.
692 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
693 must be defined, to setup the maximum idle timeout for
696 - Pre-Console Buffer:
697 Prior to the console being initialised (i.e. serial UART
698 initialised etc) all console output is silently discarded.
699 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
700 buffer any console messages prior to the console being
701 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
702 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
703 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
704 bytes are output before the console is initialised, the
705 earlier bytes are discarded.
707 'Sane' compilers will generate smaller code if
708 CONFIG_PRE_CON_BUF_SZ is a power of 2
710 - Safe printf() functions
711 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
712 the printf() functions. These are defined in
713 include/vsprintf.h and include snprintf(), vsnprintf() and
714 so on. Code size increase is approximately 300-500 bytes.
715 If this option is not given then these functions will
716 silently discard their buffer size argument - this means
717 you are not getting any overflow checking in this case.
719 - Boot Delay: CONFIG_BOOTDELAY - in seconds
720 Delay before automatically booting the default image;
721 set to -1 to disable autoboot.
722 set to -2 to autoboot with no delay and not check for abort
723 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
725 See doc/README.autoboot for these options that
726 work with CONFIG_BOOTDELAY. None are required.
727 CONFIG_BOOT_RETRY_TIME
728 CONFIG_BOOT_RETRY_MIN
729 CONFIG_AUTOBOOT_KEYED
730 CONFIG_AUTOBOOT_PROMPT
731 CONFIG_AUTOBOOT_DELAY_STR
732 CONFIG_AUTOBOOT_STOP_STR
733 CONFIG_AUTOBOOT_DELAY_STR2
734 CONFIG_AUTOBOOT_STOP_STR2
735 CONFIG_ZERO_BOOTDELAY_CHECK
736 CONFIG_RESET_TO_RETRY
740 Only needed when CONFIG_BOOTDELAY is enabled;
741 define a command string that is automatically executed
742 when no character is read on the console interface
743 within "Boot Delay" after reset.
746 This can be used to pass arguments to the bootm
747 command. The value of CONFIG_BOOTARGS goes into the
748 environment value "bootargs".
750 CONFIG_RAMBOOT and CONFIG_NFSBOOT
751 The value of these goes into the environment as
752 "ramboot" and "nfsboot" respectively, and can be used
753 as a convenience, when switching between booting from
759 When this option is #defined, the existence of the
760 environment variable "preboot" will be checked
761 immediately before starting the CONFIG_BOOTDELAY
762 countdown and/or running the auto-boot command resp.
763 entering interactive mode.
765 This feature is especially useful when "preboot" is
766 automatically generated or modified. For an example
767 see the LWMON board specific code: here "preboot" is
768 modified when the user holds down a certain
769 combination of keys on the (special) keyboard when
772 - Serial Download Echo Mode:
774 If defined to 1, all characters received during a
775 serial download (using the "loads" command) are
776 echoed back. This might be needed by some terminal
777 emulations (like "cu"), but may as well just take
778 time on others. This setting #define's the initial
779 value of the "loads_echo" environment variable.
781 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
783 Select one of the baudrates listed in
784 CONFIG_SYS_BAUDRATE_TABLE, see below.
787 Monitor commands can be included or excluded
788 from the build by using the #include files
789 <config_cmd_all.h> and #undef'ing unwanted
790 commands, or using <config_cmd_default.h>
791 and augmenting with additional #define's
794 The default command configuration includes all commands
795 except those marked below with a "*".
797 CONFIG_CMD_ASKENV * ask for env variable
798 CONFIG_CMD_BDI bdinfo
799 CONFIG_CMD_BEDBUG * Include BedBug Debugger
800 CONFIG_CMD_BMP * BMP support
801 CONFIG_CMD_BSP * Board specific commands
802 CONFIG_CMD_BOOTD bootd
803 CONFIG_CMD_CACHE * icache, dcache
804 CONFIG_CMD_CONSOLE coninfo
805 CONFIG_CMD_CRC32 * crc32
806 CONFIG_CMD_DATE * support for RTC, date/time...
807 CONFIG_CMD_DHCP * DHCP support
808 CONFIG_CMD_DIAG * Diagnostics
809 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
810 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
811 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
812 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
813 CONFIG_CMD_DTT * Digital Therm and Thermostat
814 CONFIG_CMD_ECHO echo arguments
815 CONFIG_CMD_EDITENV edit env variable
816 CONFIG_CMD_EEPROM * EEPROM read/write support
817 CONFIG_CMD_ELF * bootelf, bootvx
818 CONFIG_CMD_EXPORTENV * export the environment
819 CONFIG_CMD_EXT2 * ext2 command support
820 CONFIG_CMD_EXT4 * ext4 command support
821 CONFIG_CMD_SAVEENV saveenv
822 CONFIG_CMD_FDC * Floppy Disk Support
823 CONFIG_CMD_FAT * FAT command support
824 CONFIG_CMD_FDOS * Dos diskette Support
825 CONFIG_CMD_FLASH flinfo, erase, protect
826 CONFIG_CMD_FPGA FPGA device initialization support
827 CONFIG_CMD_GETTIME * Get time since boot
828 CONFIG_CMD_GO * the 'go' command (exec code)
829 CONFIG_CMD_GREPENV * search environment
830 CONFIG_CMD_HASH * calculate hash / digest
831 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
832 CONFIG_CMD_I2C * I2C serial bus support
833 CONFIG_CMD_IDE * IDE harddisk support
834 CONFIG_CMD_IMI iminfo
835 CONFIG_CMD_IMLS List all found images
836 CONFIG_CMD_IMMAP * IMMR dump support
837 CONFIG_CMD_IMPORTENV * import an environment
838 CONFIG_CMD_INI * import data from an ini file into the env
839 CONFIG_CMD_IRQ * irqinfo
840 CONFIG_CMD_ITEST Integer/string test of 2 values
841 CONFIG_CMD_JFFS2 * JFFS2 Support
842 CONFIG_CMD_KGDB * kgdb
843 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
844 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
846 CONFIG_CMD_LOADB loadb
847 CONFIG_CMD_LOADS loads
848 CONFIG_CMD_MD5SUM print md5 message digest
849 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
850 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
852 CONFIG_CMD_MISC Misc functions like sleep etc
853 CONFIG_CMD_MMC * MMC memory mapped support
854 CONFIG_CMD_MII * MII utility commands
855 CONFIG_CMD_MTDPARTS * MTD partition support
856 CONFIG_CMD_NAND * NAND support
857 CONFIG_CMD_NET bootp, tftpboot, rarpboot
858 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
859 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
860 CONFIG_CMD_PCI * pciinfo
861 CONFIG_CMD_PCMCIA * PCMCIA support
862 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
864 CONFIG_CMD_PORTIO * Port I/O
865 CONFIG_CMD_READ * Read raw data from partition
866 CONFIG_CMD_REGINFO * Register dump
867 CONFIG_CMD_RUN run command in env variable
868 CONFIG_CMD_SAVES * save S record dump
869 CONFIG_CMD_SCSI * SCSI Support
870 CONFIG_CMD_SDRAM * print SDRAM configuration information
871 (requires CONFIG_CMD_I2C)
872 CONFIG_CMD_SETGETDCR Support for DCR Register access
874 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
875 CONFIG_CMD_SHA1SUM print sha1 memory digest
876 (requires CONFIG_CMD_MEMORY)
877 CONFIG_CMD_SOURCE "source" command Support
878 CONFIG_CMD_SPI * SPI serial bus support
879 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
880 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
881 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
882 CONFIG_CMD_TIMER * access to the system tick timer
883 CONFIG_CMD_USB * USB support
884 CONFIG_CMD_CDP * Cisco Discover Protocol support
885 CONFIG_CMD_MFSL * Microblaze FSL support
888 EXAMPLE: If you want all functions except of network
889 support you can write:
891 #include "config_cmd_all.h"
892 #undef CONFIG_CMD_NET
895 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
897 Note: Don't enable the "icache" and "dcache" commands
898 (configuration option CONFIG_CMD_CACHE) unless you know
899 what you (and your U-Boot users) are doing. Data
900 cache cannot be enabled on systems like the 8xx or
901 8260 (where accesses to the IMMR region must be
902 uncached), and it cannot be disabled on all other
903 systems where we (mis-) use the data cache to hold an
904 initial stack and some data.
907 XXX - this list needs to get updated!
911 If this variable is defined, U-Boot will use a device tree
912 to configure its devices, instead of relying on statically
913 compiled #defines in the board file. This option is
914 experimental and only available on a few boards. The device
915 tree is available in the global data as gd->fdt_blob.
917 U-Boot needs to get its device tree from somewhere. This can
918 be done using one of the two options below:
921 If this variable is defined, U-Boot will embed a device tree
922 binary in its image. This device tree file should be in the
923 board directory and called <soc>-<board>.dts. The binary file
924 is then picked up in board_init_f() and made available through
925 the global data structure as gd->blob.
928 If this variable is defined, U-Boot will build a device tree
929 binary. It will be called u-boot.dtb. Architecture-specific
930 code will locate it at run-time. Generally this works by:
932 cat u-boot.bin u-boot.dtb >image.bin
934 and in fact, U-Boot does this for you, creating a file called
935 u-boot-dtb.bin which is useful in the common case. You can
936 still use the individual files if you need something more
941 If this variable is defined, it enables watchdog
942 support for the SoC. There must be support in the SoC
943 specific code for a watchdog. For the 8xx and 8260
944 CPUs, the SIU Watchdog feature is enabled in the SYPCR
945 register. When supported for a specific SoC is
946 available, then no further board specific code should
950 When using a watchdog circuitry external to the used
951 SoC, then define this variable and provide board
952 specific code for the "hw_watchdog_reset" function.
955 CONFIG_VERSION_VARIABLE
956 If this variable is defined, an environment variable
957 named "ver" is created by U-Boot showing the U-Boot
958 version as printed by the "version" command.
959 Any change to this variable will be reverted at the
964 When CONFIG_CMD_DATE is selected, the type of the RTC
965 has to be selected, too. Define exactly one of the
968 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
969 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
970 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
971 CONFIG_RTC_MC146818 - use MC146818 RTC
972 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
973 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
974 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
975 CONFIG_RTC_DS164x - use Dallas DS164x RTC
976 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
977 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
978 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
979 CONFIG_SYS_RV3029_TCR - enable trickle charger on
982 Note that if the RTC uses I2C, then the I2C interface
983 must also be configured. See I2C Support, below.
986 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
987 CONFIG_PCA953X_INFO - enable pca953x info command
989 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
990 chip-ngpio pairs that tell the PCA953X driver the number of
991 pins supported by a particular chip.
993 Note that if the GPIO device uses I2C, then the I2C interface
994 must also be configured. See I2C Support, below.
998 When CONFIG_TIMESTAMP is selected, the timestamp
999 (date and time) of an image is printed by image
1000 commands like bootm or iminfo. This option is
1001 automatically enabled when you select CONFIG_CMD_DATE .
1003 - Partition Labels (disklabels) Supported:
1004 Zero or more of the following:
1005 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1006 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1007 Intel architecture, USB sticks, etc.
1008 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1009 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1010 bootloader. Note 2TB partition limit; see
1012 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1014 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1015 CONFIG_CMD_SCSI) you must configure support for at
1016 least one non-MTD partition type as well.
1019 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1020 board configurations files but used nowhere!
1022 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1023 be performed by calling the function
1024 ide_set_reset(int reset)
1025 which has to be defined in a board specific file
1030 Set this to enable ATAPI support.
1035 Set this to enable support for disks larger than 137GB
1036 Also look at CONFIG_SYS_64BIT_LBA.
1037 Whithout these , LBA48 support uses 32bit variables and will 'only'
1038 support disks up to 2.1TB.
1040 CONFIG_SYS_64BIT_LBA:
1041 When enabled, makes the IDE subsystem use 64bit sector addresses.
1045 At the moment only there is only support for the
1046 SYM53C8XX SCSI controller; define
1047 CONFIG_SCSI_SYM53C8XX to enable it.
1049 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1050 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1051 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1052 maximum numbers of LUNs, SCSI ID's and target
1054 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1056 The environment variable 'scsidevs' is set to the number of
1057 SCSI devices found during the last scan.
1059 - NETWORK Support (PCI):
1061 Support for Intel 8254x/8257x gigabit chips.
1064 Utility code for direct access to the SPI bus on Intel 8257x.
1065 This does not do anything useful unless you set at least one
1066 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1068 CONFIG_E1000_SPI_GENERIC
1069 Allow generic access to the SPI bus on the Intel 8257x, for
1070 example with the "sspi" command.
1073 Management command for E1000 devices. When used on devices
1074 with SPI support you can reprogram the EEPROM from U-Boot.
1076 CONFIG_E1000_FALLBACK_MAC
1077 default MAC for empty EEPROM after production.
1080 Support for Intel 82557/82559/82559ER chips.
1081 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1082 write routine for first time initialisation.
1085 Support for Digital 2114x chips.
1086 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1087 modem chip initialisation (KS8761/QS6611).
1090 Support for National dp83815 chips.
1093 Support for National dp8382[01] gigabit chips.
1095 - NETWORK Support (other):
1097 CONFIG_DRIVER_AT91EMAC
1098 Support for AT91RM9200 EMAC.
1101 Define this to use reduced MII inteface
1103 CONFIG_DRIVER_AT91EMAC_QUIET
1104 If this defined, the driver is quiet.
1105 The driver doen't show link status messages.
1107 CONFIG_CALXEDA_XGMAC
1108 Support for the Calxeda XGMAC device
1111 Support for SMSC's LAN91C96 chips.
1113 CONFIG_LAN91C96_BASE
1114 Define this to hold the physical address
1115 of the LAN91C96's I/O space
1117 CONFIG_LAN91C96_USE_32_BIT
1118 Define this to enable 32 bit addressing
1121 Support for SMSC's LAN91C111 chip
1123 CONFIG_SMC91111_BASE
1124 Define this to hold the physical address
1125 of the device (I/O space)
1127 CONFIG_SMC_USE_32_BIT
1128 Define this if data bus is 32 bits
1130 CONFIG_SMC_USE_IOFUNCS
1131 Define this to use i/o functions instead of macros
1132 (some hardware wont work with macros)
1134 CONFIG_DRIVER_TI_EMAC
1135 Support for davinci emac
1137 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1138 Define this if you have more then 3 PHYs.
1141 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1143 CONFIG_FTGMAC100_EGIGA
1144 Define this to use GE link update with gigabit PHY.
1145 Define this if FTGMAC100 is connected to gigabit PHY.
1146 If your system has 10/100 PHY only, it might not occur
1147 wrong behavior. Because PHY usually return timeout or
1148 useless data when polling gigabit status and gigabit
1149 control registers. This behavior won't affect the
1150 correctnessof 10/100 link speed update.
1153 Support for SMSC's LAN911x and LAN921x chips
1156 Define this to hold the physical address
1157 of the device (I/O space)
1159 CONFIG_SMC911X_32_BIT
1160 Define this if data bus is 32 bits
1162 CONFIG_SMC911X_16_BIT
1163 Define this if data bus is 16 bits. If your processor
1164 automatically converts one 32 bit word to two 16 bit
1165 words you may also try CONFIG_SMC911X_32_BIT.
1168 Support for Renesas on-chip Ethernet controller
1170 CONFIG_SH_ETHER_USE_PORT
1171 Define the number of ports to be used
1173 CONFIG_SH_ETHER_PHY_ADDR
1174 Define the ETH PHY's address
1176 CONFIG_SH_ETHER_CACHE_WRITEBACK
1177 If this option is set, the driver enables cache flush.
1180 CONFIG_GENERIC_LPC_TPM
1181 Support for generic parallel port TPM devices. Only one device
1182 per system is supported at this time.
1184 CONFIG_TPM_TIS_BASE_ADDRESS
1185 Base address where the generic TPM device is mapped
1186 to. Contemporary x86 systems usually map it at
1190 At the moment only the UHCI host controller is
1191 supported (PIP405, MIP405, MPC5200); define
1192 CONFIG_USB_UHCI to enable it.
1193 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1194 and define CONFIG_USB_STORAGE to enable the USB
1197 Supported are USB Keyboards and USB Floppy drives
1199 MPC5200 USB requires additional defines:
1201 for 528 MHz Clock: 0x0001bbbb
1205 for differential drivers: 0x00001000
1206 for single ended drivers: 0x00005000
1207 for differential drivers on PSC3: 0x00000100
1208 for single ended drivers on PSC3: 0x00004100
1209 CONFIG_SYS_USB_EVENT_POLL
1210 May be defined to allow interrupt polling
1211 instead of using asynchronous interrupts
1213 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1214 txfilltuning field in the EHCI controller on reset.
1217 Define the below if you wish to use the USB console.
1218 Once firmware is rebuilt from a serial console issue the
1219 command "setenv stdin usbtty; setenv stdout usbtty" and
1220 attach your USB cable. The Unix command "dmesg" should print
1221 it has found a new device. The environment variable usbtty
1222 can be set to gserial or cdc_acm to enable your device to
1223 appear to a USB host as a Linux gserial device or a
1224 Common Device Class Abstract Control Model serial device.
1225 If you select usbtty = gserial you should be able to enumerate
1227 # modprobe usbserial vendor=0xVendorID product=0xProductID
1228 else if using cdc_acm, simply setting the environment
1229 variable usbtty to be cdc_acm should suffice. The following
1230 might be defined in YourBoardName.h
1233 Define this to build a UDC device
1236 Define this to have a tty type of device available to
1237 talk to the UDC device
1240 Define this to enable the high speed support for usb
1241 device and usbtty. If this feature is enabled, a routine
1242 int is_usbd_high_speed(void)
1243 also needs to be defined by the driver to dynamically poll
1244 whether the enumeration has succeded at high speed or full
1247 CONFIG_SYS_CONSOLE_IS_IN_ENV
1248 Define this if you want stdin, stdout &/or stderr to
1252 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1253 Derive USB clock from external clock "blah"
1254 - CONFIG_SYS_USB_EXTC_CLK 0x02
1256 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1257 Derive USB clock from brgclk
1258 - CONFIG_SYS_USB_BRG_CLK 0x04
1260 If you have a USB-IF assigned VendorID then you may wish to
1261 define your own vendor specific values either in BoardName.h
1262 or directly in usbd_vendor_info.h. If you don't define
1263 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1264 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1265 should pretend to be a Linux device to it's target host.
1267 CONFIG_USBD_MANUFACTURER
1268 Define this string as the name of your company for
1269 - CONFIG_USBD_MANUFACTURER "my company"
1271 CONFIG_USBD_PRODUCT_NAME
1272 Define this string as the name of your product
1273 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1275 CONFIG_USBD_VENDORID
1276 Define this as your assigned Vendor ID from the USB
1277 Implementors Forum. This *must* be a genuine Vendor ID
1278 to avoid polluting the USB namespace.
1279 - CONFIG_USBD_VENDORID 0xFFFF
1281 CONFIG_USBD_PRODUCTID
1282 Define this as the unique Product ID
1284 - CONFIG_USBD_PRODUCTID 0xFFFF
1286 - ULPI Layer Support:
1287 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1288 the generic ULPI layer. The generic layer accesses the ULPI PHY
1289 via the platform viewport, so you need both the genric layer and
1290 the viewport enabled. Currently only Chipidea/ARC based
1291 viewport is supported.
1292 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1293 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1294 If your ULPI phy needs a different reference clock than the
1295 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1296 the appropriate value in Hz.
1299 The MMC controller on the Intel PXA is supported. To
1300 enable this define CONFIG_MMC. The MMC can be
1301 accessed from the boot prompt by mapping the device
1302 to physical memory similar to flash. Command line is
1303 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1304 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1307 Support for Renesas on-chip MMCIF controller
1309 CONFIG_SH_MMCIF_ADDR
1310 Define the base address of MMCIF registers
1313 Define the clock frequency for MMCIF
1315 - Journaling Flash filesystem support:
1316 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1317 CONFIG_JFFS2_NAND_DEV
1318 Define these for a default partition on a NAND device
1320 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1321 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1322 Define these for a default partition on a NOR device
1324 CONFIG_SYS_JFFS_CUSTOM_PART
1325 Define this to create an own partition. You have to provide a
1326 function struct part_info* jffs2_part_info(int part_num)
1328 If you define only one JFFS2 partition you may also want to
1329 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1330 to disable the command chpart. This is the default when you
1331 have not defined a custom partition
1333 - FAT(File Allocation Table) filesystem write function support:
1336 Define this to enable support for saving memory data as a
1337 file in FAT formatted partition.
1339 This will also enable the command "fatwrite" enabling the
1340 user to write files to FAT.
1342 CBFS (Coreboot Filesystem) support
1345 Define this to enable support for reading from a Coreboot
1346 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1352 Define this to enable standard (PC-Style) keyboard
1356 Standard PC keyboard driver with US (is default) and
1357 GERMAN key layout (switch via environment 'keymap=de') support.
1358 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1359 for cfb_console. Supports cursor blinking.
1364 Define this to enable video support (for output to
1367 CONFIG_VIDEO_CT69000
1369 Enable Chips & Technologies 69000 Video chip
1371 CONFIG_VIDEO_SMI_LYNXEM
1372 Enable Silicon Motion SMI 712/710/810 Video chip. The
1373 video output is selected via environment 'videoout'
1374 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1377 For the CT69000 and SMI_LYNXEM drivers, videomode is
1378 selected via environment 'videomode'. Two different ways
1380 - "videomode=num" 'num' is a standard LiLo mode numbers.
1381 Following standard modes are supported (* is default):
1383 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1384 -------------+---------------------------------------------
1385 8 bits | 0x301* 0x303 0x305 0x161 0x307
1386 15 bits | 0x310 0x313 0x316 0x162 0x319
1387 16 bits | 0x311 0x314 0x317 0x163 0x31A
1388 24 bits | 0x312 0x315 0x318 ? 0x31B
1389 -------------+---------------------------------------------
1390 (i.e. setenv videomode 317; saveenv; reset;)
1392 - "videomode=bootargs" all the video parameters are parsed
1393 from the bootargs. (See drivers/video/videomodes.c)
1396 CONFIG_VIDEO_SED13806
1397 Enable Epson SED13806 driver. This driver supports 8bpp
1398 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1399 or CONFIG_VIDEO_SED13806_16BPP
1402 Enable the Freescale DIU video driver. Reference boards for
1403 SOCs that have a DIU should define this macro to enable DIU
1404 support, and should also define these other macros:
1410 CONFIG_VIDEO_SW_CURSOR
1411 CONFIG_VGA_AS_SINGLE_DEVICE
1413 CONFIG_VIDEO_BMP_LOGO
1415 The DIU driver will look for the 'video-mode' environment
1416 variable, and if defined, enable the DIU as a console during
1417 boot. See the documentation file README.video for a
1418 description of this variable.
1422 Enable the VGA video / BIOS for x86. The alternative if you
1423 are using coreboot is to use the coreboot frame buffer
1430 Define this to enable a custom keyboard support.
1431 This simply calls drv_keyboard_init() which must be
1432 defined in your board-specific files.
1433 The only board using this so far is RBC823.
1435 - LCD Support: CONFIG_LCD
1437 Define this to enable LCD support (for output to LCD
1438 display); also select one of the supported displays
1439 by defining one of these:
1443 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1445 CONFIG_NEC_NL6448AC33:
1447 NEC NL6448AC33-18. Active, color, single scan.
1449 CONFIG_NEC_NL6448BC20
1451 NEC NL6448BC20-08. 6.5", 640x480.
1452 Active, color, single scan.
1454 CONFIG_NEC_NL6448BC33_54
1456 NEC NL6448BC33-54. 10.4", 640x480.
1457 Active, color, single scan.
1461 Sharp 320x240. Active, color, single scan.
1462 It isn't 16x9, and I am not sure what it is.
1464 CONFIG_SHARP_LQ64D341
1466 Sharp LQ64D341 display, 640x480.
1467 Active, color, single scan.
1471 HLD1045 display, 640x480.
1472 Active, color, single scan.
1476 Optrex CBL50840-2 NF-FW 99 22 M5
1478 Hitachi LMG6912RPFC-00T
1482 320x240. Black & white.
1484 Normally display is black on white background; define
1485 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1489 Support drawing of RLE8-compressed bitmaps on the LCD.
1492 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1494 If this option is set, the environment is checked for
1495 a variable "splashimage". If found, the usual display
1496 of logo, copyright and system information on the LCD
1497 is suppressed and the BMP image at the address
1498 specified in "splashimage" is loaded instead. The
1499 console is redirected to the "nulldev", too. This
1500 allows for a "silent" boot where a splash screen is
1501 loaded very quickly after power-on.
1503 CONFIG_SPLASH_SCREEN_ALIGN
1505 If this option is set the splash image can be freely positioned
1506 on the screen. Environment variable "splashpos" specifies the
1507 position as "x,y". If a positive number is given it is used as
1508 number of pixel from left/top. If a negative number is given it
1509 is used as number of pixel from right/bottom. You can also
1510 specify 'm' for centering the image.
1513 setenv splashpos m,m
1514 => image at center of screen
1516 setenv splashpos 30,20
1517 => image at x = 30 and y = 20
1519 setenv splashpos -10,m
1520 => vertically centered image
1521 at x = dspWidth - bmpWidth - 9
1523 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1525 If this option is set, additionally to standard BMP
1526 images, gzipped BMP images can be displayed via the
1527 splashscreen support or the bmp command.
1529 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1531 If this option is set, 8-bit RLE compressed BMP images
1532 can be displayed via the splashscreen support or the
1535 - Do compresssing for memory range:
1538 If this option is set, it would use zlib deflate method
1539 to compress the specified memory at its best effort.
1541 - Compression support:
1544 If this option is set, support for bzip2 compressed
1545 images is included. If not, only uncompressed and gzip
1546 compressed images are supported.
1548 NOTE: the bzip2 algorithm requires a lot of RAM, so
1549 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1554 If this option is set, support for lzma compressed
1557 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1558 requires an amount of dynamic memory that is given by the
1561 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1563 Where lc and lp stand for, respectively, Literal context bits
1564 and Literal pos bits.
1566 This value is upper-bounded by 14MB in the worst case. Anyway,
1567 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1568 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1569 a very small buffer.
1571 Use the lzmainfo tool to determinate the lc and lp values and
1572 then calculate the amount of needed dynamic memory (ensuring
1573 the appropriate CONFIG_SYS_MALLOC_LEN value).
1578 The address of PHY on MII bus.
1580 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1582 The clock frequency of the MII bus
1586 If this option is set, support for speed/duplex
1587 detection of gigabit PHY is included.
1589 CONFIG_PHY_RESET_DELAY
1591 Some PHY like Intel LXT971A need extra delay after
1592 reset before any MII register access is possible.
1593 For such PHY, set this option to the usec delay
1594 required. (minimum 300usec for LXT971A)
1596 CONFIG_PHY_CMD_DELAY (ppc4xx)
1598 Some PHY like Intel LXT971A need extra delay after
1599 command issued before MII status register can be read
1609 Define a default value for Ethernet address to use
1610 for the respective Ethernet interface, in case this
1611 is not determined automatically.
1616 Define a default value for the IP address to use for
1617 the default Ethernet interface, in case this is not
1618 determined through e.g. bootp.
1619 (Environment variable "ipaddr")
1621 - Server IP address:
1624 Defines a default value for the IP address of a TFTP
1625 server to contact when using the "tftboot" command.
1626 (Environment variable "serverip")
1628 CONFIG_KEEP_SERVERADDR
1630 Keeps the server's MAC address, in the env 'serveraddr'
1631 for passing to bootargs (like Linux's netconsole option)
1633 - Gateway IP address:
1636 Defines a default value for the IP address of the
1637 default router where packets to other networks are
1639 (Environment variable "gatewayip")
1644 Defines a default value for the subnet mask (or
1645 routing prefix) which is used to determine if an IP
1646 address belongs to the local subnet or needs to be
1647 forwarded through a router.
1648 (Environment variable "netmask")
1650 - Multicast TFTP Mode:
1653 Defines whether you want to support multicast TFTP as per
1654 rfc-2090; for example to work with atftp. Lets lots of targets
1655 tftp down the same boot image concurrently. Note: the Ethernet
1656 driver in use must provide a function: mcast() to join/leave a
1659 - BOOTP Recovery Mode:
1660 CONFIG_BOOTP_RANDOM_DELAY
1662 If you have many targets in a network that try to
1663 boot using BOOTP, you may want to avoid that all
1664 systems send out BOOTP requests at precisely the same
1665 moment (which would happen for instance at recovery
1666 from a power failure, when all systems will try to
1667 boot, thus flooding the BOOTP server. Defining
1668 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1669 inserted before sending out BOOTP requests. The
1670 following delays are inserted then:
1672 1st BOOTP request: delay 0 ... 1 sec
1673 2nd BOOTP request: delay 0 ... 2 sec
1674 3rd BOOTP request: delay 0 ... 4 sec
1676 BOOTP requests: delay 0 ... 8 sec
1678 - DHCP Advanced Options:
1679 You can fine tune the DHCP functionality by defining
1680 CONFIG_BOOTP_* symbols:
1682 CONFIG_BOOTP_SUBNETMASK
1683 CONFIG_BOOTP_GATEWAY
1684 CONFIG_BOOTP_HOSTNAME
1685 CONFIG_BOOTP_NISDOMAIN
1686 CONFIG_BOOTP_BOOTPATH
1687 CONFIG_BOOTP_BOOTFILESIZE
1690 CONFIG_BOOTP_SEND_HOSTNAME
1691 CONFIG_BOOTP_NTPSERVER
1692 CONFIG_BOOTP_TIMEOFFSET
1693 CONFIG_BOOTP_VENDOREX
1694 CONFIG_BOOTP_MAY_FAIL
1696 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1697 environment variable, not the BOOTP server.
1699 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1700 after the configured retry count, the call will fail
1701 instead of starting over. This can be used to fail over
1702 to Link-local IP address configuration if the DHCP server
1705 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1706 serverip from a DHCP server, it is possible that more
1707 than one DNS serverip is offered to the client.
1708 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1709 serverip will be stored in the additional environment
1710 variable "dnsip2". The first DNS serverip is always
1711 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1714 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1715 to do a dynamic update of a DNS server. To do this, they
1716 need the hostname of the DHCP requester.
1717 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1718 of the "hostname" environment variable is passed as
1719 option 12 to the DHCP server.
1721 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1723 A 32bit value in microseconds for a delay between
1724 receiving a "DHCP Offer" and sending the "DHCP Request".
1725 This fixes a problem with certain DHCP servers that don't
1726 respond 100% of the time to a "DHCP request". E.g. On an
1727 AT91RM9200 processor running at 180MHz, this delay needed
1728 to be *at least* 15,000 usec before a Windows Server 2003
1729 DHCP server would reply 100% of the time. I recommend at
1730 least 50,000 usec to be safe. The alternative is to hope
1731 that one of the retries will be successful but note that
1732 the DHCP timeout and retry process takes a longer than
1735 - Link-local IP address negotiation:
1736 Negotiate with other link-local clients on the local network
1737 for an address that doesn't require explicit configuration.
1738 This is especially useful if a DHCP server cannot be guaranteed
1739 to exist in all environments that the device must operate.
1741 See doc/README.link-local for more information.
1744 CONFIG_CDP_DEVICE_ID
1746 The device id used in CDP trigger frames.
1748 CONFIG_CDP_DEVICE_ID_PREFIX
1750 A two character string which is prefixed to the MAC address
1755 A printf format string which contains the ascii name of
1756 the port. Normally is set to "eth%d" which sets
1757 eth0 for the first Ethernet, eth1 for the second etc.
1759 CONFIG_CDP_CAPABILITIES
1761 A 32bit integer which indicates the device capabilities;
1762 0x00000010 for a normal host which does not forwards.
1766 An ascii string containing the version of the software.
1770 An ascii string containing the name of the platform.
1774 A 32bit integer sent on the trigger.
1776 CONFIG_CDP_POWER_CONSUMPTION
1778 A 16bit integer containing the power consumption of the
1779 device in .1 of milliwatts.
1781 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1783 A byte containing the id of the VLAN.
1785 - Status LED: CONFIG_STATUS_LED
1787 Several configurations allow to display the current
1788 status using a LED. For instance, the LED will blink
1789 fast while running U-Boot code, stop blinking as
1790 soon as a reply to a BOOTP request was received, and
1791 start blinking slow once the Linux kernel is running
1792 (supported by a status LED driver in the Linux
1793 kernel). Defining CONFIG_STATUS_LED enables this
1796 - CAN Support: CONFIG_CAN_DRIVER
1798 Defining CONFIG_CAN_DRIVER enables CAN driver support
1799 on those systems that support this (optional)
1800 feature, like the TQM8xxL modules.
1802 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1804 These enable I2C serial bus commands. Defining either of
1805 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1806 include the appropriate I2C driver for the selected CPU.
1808 This will allow you to use i2c commands at the u-boot
1809 command line (as long as you set CONFIG_CMD_I2C in
1810 CONFIG_COMMANDS) and communicate with i2c based realtime
1811 clock chips. See common/cmd_i2c.c for a description of the
1812 command line interface.
1814 CONFIG_HARD_I2C selects a hardware I2C controller.
1816 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1817 bit-banging) driver instead of CPM or similar hardware
1820 There are several other quantities that must also be
1821 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1823 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1824 to be the frequency (in Hz) at which you wish your i2c bus
1825 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1826 the CPU's i2c node address).
1828 Now, the u-boot i2c code for the mpc8xx
1829 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1830 and so its address should therefore be cleared to 0 (See,
1831 eg, MPC823e User's Manual p.16-473). So, set
1832 CONFIG_SYS_I2C_SLAVE to 0.
1834 CONFIG_SYS_I2C_INIT_MPC5XXX
1836 When a board is reset during an i2c bus transfer
1837 chips might think that the current transfer is still
1838 in progress. Reset the slave devices by sending start
1839 commands until the slave device responds.
1841 That's all that's required for CONFIG_HARD_I2C.
1843 If you use the software i2c interface (CONFIG_SOFT_I2C)
1844 then the following macros need to be defined (examples are
1845 from include/configs/lwmon.h):
1849 (Optional). Any commands necessary to enable the I2C
1850 controller or configure ports.
1852 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1856 (Only for MPC8260 CPU). The I/O port to use (the code
1857 assumes both bits are on the same port). Valid values
1858 are 0..3 for ports A..D.
1862 The code necessary to make the I2C data line active
1863 (driven). If the data line is open collector, this
1866 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1870 The code necessary to make the I2C data line tri-stated
1871 (inactive). If the data line is open collector, this
1874 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1878 Code that returns TRUE if the I2C data line is high,
1881 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1885 If <bit> is TRUE, sets the I2C data line high. If it
1886 is FALSE, it clears it (low).
1888 eg: #define I2C_SDA(bit) \
1889 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1890 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1894 If <bit> is TRUE, sets the I2C clock line high. If it
1895 is FALSE, it clears it (low).
1897 eg: #define I2C_SCL(bit) \
1898 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1899 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1903 This delay is invoked four times per clock cycle so this
1904 controls the rate of data transfer. The data rate thus
1905 is 1 / (I2C_DELAY * 4). Often defined to be something
1908 #define I2C_DELAY udelay(2)
1910 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1912 If your arch supports the generic GPIO framework (asm/gpio.h),
1913 then you may alternatively define the two GPIOs that are to be
1914 used as SCL / SDA. Any of the previous I2C_xxx macros will
1915 have GPIO-based defaults assigned to them as appropriate.
1917 You should define these to the GPIO value as given directly to
1918 the generic GPIO functions.
1920 CONFIG_SYS_I2C_INIT_BOARD
1922 When a board is reset during an i2c bus transfer
1923 chips might think that the current transfer is still
1924 in progress. On some boards it is possible to access
1925 the i2c SCLK line directly, either by using the
1926 processor pin as a GPIO or by having a second pin
1927 connected to the bus. If this option is defined a
1928 custom i2c_init_board() routine in boards/xxx/board.c
1929 is run early in the boot sequence.
1931 CONFIG_SYS_I2C_BOARD_LATE_INIT
1933 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1934 defined a custom i2c_board_late_init() routine in
1935 boards/xxx/board.c is run AFTER the operations in i2c_init()
1936 is completed. This callpoint can be used to unreset i2c bus
1937 using CPU i2c controller register accesses for CPUs whose i2c
1938 controller provide such a method. It is called at the end of
1939 i2c_init() to allow i2c_init operations to setup the i2c bus
1940 controller on the CPU (e.g. setting bus speed & slave address).
1942 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1944 This option enables configuration of bi_iic_fast[] flags
1945 in u-boot bd_info structure based on u-boot environment
1946 variable "i2cfast". (see also i2cfast)
1948 CONFIG_I2C_MULTI_BUS
1950 This option allows the use of multiple I2C buses, each of which
1951 must have a controller. At any point in time, only one bus is
1952 active. To switch to a different bus, use the 'i2c dev' command.
1953 Note that bus numbering is zero-based.
1955 CONFIG_SYS_I2C_NOPROBES
1957 This option specifies a list of I2C devices that will be skipped
1958 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1959 is set, specify a list of bus-device pairs. Otherwise, specify
1960 a 1D array of device addresses
1963 #undef CONFIG_I2C_MULTI_BUS
1964 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1966 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1968 #define CONFIG_I2C_MULTI_BUS
1969 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1971 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1973 CONFIG_SYS_SPD_BUS_NUM
1975 If defined, then this indicates the I2C bus number for DDR SPD.
1976 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1978 CONFIG_SYS_RTC_BUS_NUM
1980 If defined, then this indicates the I2C bus number for the RTC.
1981 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1983 CONFIG_SYS_DTT_BUS_NUM
1985 If defined, then this indicates the I2C bus number for the DTT.
1986 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1988 CONFIG_SYS_I2C_DTT_ADDR:
1990 If defined, specifies the I2C address of the DTT device.
1991 If not defined, then U-Boot uses predefined value for
1992 specified DTT device.
1996 Define this option if you want to use Freescale's I2C driver in
1997 drivers/i2c/fsl_i2c.c.
2001 Define this option if you have I2C devices reached over 1 .. n
2002 I2C Muxes like the pca9544a. This option addes a new I2C
2003 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2004 new I2C Bus to the existing I2C Busses. If you select the
2005 new Bus with "i2c dev", u-bbot sends first the commandos for
2006 the muxes to activate this new "bus".
2008 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2012 Adding a new I2C Bus reached over 2 pca9544a muxes
2013 The First mux with address 70 and channel 6
2014 The Second mux with address 71 and channel 4
2016 => i2c bus pca9544a:70:6:pca9544a:71:4
2018 Use the "i2c bus" command without parameter, to get a list
2019 of I2C Busses with muxes:
2022 Busses reached over muxes:
2024 reached over Mux(es):
2027 reached over Mux(es):
2032 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2033 u-boot first sends the command to the mux@70 to enable
2034 channel 6, and then the command to the mux@71 to enable
2037 After that, you can use the "normal" i2c commands as
2038 usual to communicate with your I2C devices behind
2041 This option is actually implemented for the bitbanging
2042 algorithm in common/soft_i2c.c and for the Hardware I2C
2043 Bus on the MPC8260. But it should be not so difficult
2044 to add this option to other architectures.
2046 CONFIG_SOFT_I2C_READ_REPEATED_START
2048 defining this will force the i2c_read() function in
2049 the soft_i2c driver to perform an I2C repeated start
2050 between writing the address pointer and reading the
2051 data. If this define is omitted the default behaviour
2052 of doing a stop-start sequence will be used. Most I2C
2053 devices can use either method, but some require one or
2056 - SPI Support: CONFIG_SPI
2058 Enables SPI driver (so far only tested with
2059 SPI EEPROM, also an instance works with Crystal A/D and
2060 D/As on the SACSng board)
2064 Enables the driver for SPI controller on SuperH. Currently
2065 only SH7757 is supported.
2069 Enables extended (16-bit) SPI EEPROM addressing.
2070 (symmetrical to CONFIG_I2C_X)
2074 Enables a software (bit-bang) SPI driver rather than
2075 using hardware support. This is a general purpose
2076 driver that only requires three general I/O port pins
2077 (two outputs, one input) to function. If this is
2078 defined, the board configuration must define several
2079 SPI configuration items (port pins to use, etc). For
2080 an example, see include/configs/sacsng.h.
2084 Enables a hardware SPI driver for general-purpose reads
2085 and writes. As with CONFIG_SOFT_SPI, the board configuration
2086 must define a list of chip-select function pointers.
2087 Currently supported on some MPC8xxx processors. For an
2088 example, see include/configs/mpc8349emds.h.
2092 Enables the driver for the SPI controllers on i.MX and MXC
2093 SoCs. Currently i.MX31/35/51 are supported.
2095 - FPGA Support: CONFIG_FPGA
2097 Enables FPGA subsystem.
2099 CONFIG_FPGA_<vendor>
2101 Enables support for specific chip vendors.
2104 CONFIG_FPGA_<family>
2106 Enables support for FPGA family.
2107 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2111 Specify the number of FPGA devices to support.
2113 CONFIG_SYS_FPGA_PROG_FEEDBACK
2115 Enable printing of hash marks during FPGA configuration.
2117 CONFIG_SYS_FPGA_CHECK_BUSY
2119 Enable checks on FPGA configuration interface busy
2120 status by the configuration function. This option
2121 will require a board or device specific function to
2126 If defined, a function that provides delays in the FPGA
2127 configuration driver.
2129 CONFIG_SYS_FPGA_CHECK_CTRLC
2130 Allow Control-C to interrupt FPGA configuration
2132 CONFIG_SYS_FPGA_CHECK_ERROR
2134 Check for configuration errors during FPGA bitfile
2135 loading. For example, abort during Virtex II
2136 configuration if the INIT_B line goes low (which
2137 indicated a CRC error).
2139 CONFIG_SYS_FPGA_WAIT_INIT
2141 Maximum time to wait for the INIT_B line to deassert
2142 after PROB_B has been deasserted during a Virtex II
2143 FPGA configuration sequence. The default time is 500
2146 CONFIG_SYS_FPGA_WAIT_BUSY
2148 Maximum time to wait for BUSY to deassert during
2149 Virtex II FPGA configuration. The default is 5 ms.
2151 CONFIG_SYS_FPGA_WAIT_CONFIG
2153 Time to wait after FPGA configuration. The default is
2156 - Configuration Management:
2159 If defined, this string will be added to the U-Boot
2160 version information (U_BOOT_VERSION)
2162 - Vendor Parameter Protection:
2164 U-Boot considers the values of the environment
2165 variables "serial#" (Board Serial Number) and
2166 "ethaddr" (Ethernet Address) to be parameters that
2167 are set once by the board vendor / manufacturer, and
2168 protects these variables from casual modification by
2169 the user. Once set, these variables are read-only,
2170 and write or delete attempts are rejected. You can
2171 change this behaviour:
2173 If CONFIG_ENV_OVERWRITE is #defined in your config
2174 file, the write protection for vendor parameters is
2175 completely disabled. Anybody can change or delete
2178 Alternatively, if you #define _both_ CONFIG_ETHADDR
2179 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2180 Ethernet address is installed in the environment,
2181 which can be changed exactly ONCE by the user. [The
2182 serial# is unaffected by this, i. e. it remains
2188 Define this variable to enable the reservation of
2189 "protected RAM", i. e. RAM which is not overwritten
2190 by U-Boot. Define CONFIG_PRAM to hold the number of
2191 kB you want to reserve for pRAM. You can overwrite
2192 this default value by defining an environment
2193 variable "pram" to the number of kB you want to
2194 reserve. Note that the board info structure will
2195 still show the full amount of RAM. If pRAM is
2196 reserved, a new environment variable "mem" will
2197 automatically be defined to hold the amount of
2198 remaining RAM in a form that can be passed as boot
2199 argument to Linux, for instance like that:
2201 setenv bootargs ... mem=\${mem}
2204 This way you can tell Linux not to use this memory,
2205 either, which results in a memory region that will
2206 not be affected by reboots.
2208 *WARNING* If your board configuration uses automatic
2209 detection of the RAM size, you must make sure that
2210 this memory test is non-destructive. So far, the
2211 following board configurations are known to be
2214 IVMS8, IVML24, SPD8xx, TQM8xxL,
2215 HERMES, IP860, RPXlite, LWMON,
2218 - Access to physical memory region (> 4GB)
2219 Some basic support is provided for operations on memory not
2220 normally accessible to U-Boot - e.g. some architectures
2221 support access to more than 4GB of memory on 32-bit
2222 machines using physical address extension or similar.
2223 Define CONFIG_PHYSMEM to access this basic support, which
2224 currently only supports clearing the memory.
2229 Define this variable to stop the system in case of a
2230 fatal error, so that you have to reset it manually.
2231 This is probably NOT a good idea for an embedded
2232 system where you want the system to reboot
2233 automatically as fast as possible, but it may be
2234 useful during development since you can try to debug
2235 the conditions that lead to the situation.
2237 CONFIG_NET_RETRY_COUNT
2239 This variable defines the number of retries for
2240 network operations like ARP, RARP, TFTP, or BOOTP
2241 before giving up the operation. If not defined, a
2242 default value of 5 is used.
2246 Timeout waiting for an ARP reply in milliseconds.
2250 Timeout in milliseconds used in NFS protocol.
2251 If you encounter "ERROR: Cannot umount" in nfs command,
2252 try longer timeout such as
2253 #define CONFIG_NFS_TIMEOUT 10000UL
2255 - Command Interpreter:
2256 CONFIG_AUTO_COMPLETE
2258 Enable auto completion of commands using TAB.
2260 Note that this feature has NOT been implemented yet
2261 for the "hush" shell.
2264 CONFIG_SYS_HUSH_PARSER
2266 Define this variable to enable the "hush" shell (from
2267 Busybox) as command line interpreter, thus enabling
2268 powerful command line syntax like
2269 if...then...else...fi conditionals or `&&' and '||'
2270 constructs ("shell scripts").
2272 If undefined, you get the old, much simpler behaviour
2273 with a somewhat smaller memory footprint.
2276 CONFIG_SYS_PROMPT_HUSH_PS2
2278 This defines the secondary prompt string, which is
2279 printed when the command interpreter needs more input
2280 to complete a command. Usually "> ".
2284 In the current implementation, the local variables
2285 space and global environment variables space are
2286 separated. Local variables are those you define by
2287 simply typing `name=value'. To access a local
2288 variable later on, you have write `$name' or
2289 `${name}'; to execute the contents of a variable
2290 directly type `$name' at the command prompt.
2292 Global environment variables are those you use
2293 setenv/printenv to work with. To run a command stored
2294 in such a variable, you need to use the run command,
2295 and you must not use the '$' sign to access them.
2297 To store commands and special characters in a
2298 variable, please use double quotation marks
2299 surrounding the whole text of the variable, instead
2300 of the backslashes before semicolons and special
2303 - Commandline Editing and History:
2304 CONFIG_CMDLINE_EDITING
2306 Enable editing and History functions for interactive
2307 commandline input operations
2309 - Default Environment:
2310 CONFIG_EXTRA_ENV_SETTINGS
2312 Define this to contain any number of null terminated
2313 strings (variable = value pairs) that will be part of
2314 the default environment compiled into the boot image.
2316 For example, place something like this in your
2317 board's config file:
2319 #define CONFIG_EXTRA_ENV_SETTINGS \
2323 Warning: This method is based on knowledge about the
2324 internal format how the environment is stored by the
2325 U-Boot code. This is NOT an official, exported
2326 interface! Although it is unlikely that this format
2327 will change soon, there is no guarantee either.
2328 You better know what you are doing here.
2330 Note: overly (ab)use of the default environment is
2331 discouraged. Make sure to check other ways to preset
2332 the environment like the "source" command or the
2335 CONFIG_ENV_VARS_UBOOT_CONFIG
2337 Define this in order to add variables describing the
2338 U-Boot build configuration to the default environment.
2339 These will be named arch, cpu, board, vendor, and soc.
2341 Enabling this option will cause the following to be defined:
2349 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2351 Define this in order to add variables describing certain
2352 run-time determined information about the hardware to the
2353 environment. These will be named board_name, board_rev.
2355 - DataFlash Support:
2356 CONFIG_HAS_DATAFLASH
2358 Defining this option enables DataFlash features and
2359 allows to read/write in Dataflash via the standard
2362 - Serial Flash support
2365 Defining this option enables SPI flash commands
2366 'sf probe/read/write/erase/update'.
2368 Usage requires an initial 'probe' to define the serial
2369 flash parameters, followed by read/write/erase/update
2372 The following defaults may be provided by the platform
2373 to handle the common case when only a single serial
2374 flash is present on the system.
2376 CONFIG_SF_DEFAULT_BUS Bus identifier
2377 CONFIG_SF_DEFAULT_CS Chip-select
2378 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2379 CONFIG_SF_DEFAULT_SPEED in Hz
2381 - SystemACE Support:
2384 Adding this option adds support for Xilinx SystemACE
2385 chips attached via some sort of local bus. The address
2386 of the chip must also be defined in the
2387 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2389 #define CONFIG_SYSTEMACE
2390 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2392 When SystemACE support is added, the "ace" device type
2393 becomes available to the fat commands, i.e. fatls.
2395 - TFTP Fixed UDP Port:
2398 If this is defined, the environment variable tftpsrcp
2399 is used to supply the TFTP UDP source port value.
2400 If tftpsrcp isn't defined, the normal pseudo-random port
2401 number generator is used.
2403 Also, the environment variable tftpdstp is used to supply
2404 the TFTP UDP destination port value. If tftpdstp isn't
2405 defined, the normal port 69 is used.
2407 The purpose for tftpsrcp is to allow a TFTP server to
2408 blindly start the TFTP transfer using the pre-configured
2409 target IP address and UDP port. This has the effect of
2410 "punching through" the (Windows XP) firewall, allowing
2411 the remainder of the TFTP transfer to proceed normally.
2412 A better solution is to properly configure the firewall,
2413 but sometimes that is not allowed.
2418 This enables a generic 'hash' command which can produce
2419 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2423 Enable the hash verify command (hash -v). This adds to code
2426 CONFIG_SHA1 - support SHA1 hashing
2427 CONFIG_SHA256 - support SHA256 hashing
2429 Note: There is also a sha1sum command, which should perhaps
2430 be deprecated in favour of 'hash sha1'.
2432 - Show boot progress:
2433 CONFIG_SHOW_BOOT_PROGRESS
2435 Defining this option allows to add some board-
2436 specific code (calling a user-provided function
2437 "show_boot_progress(int)") that enables you to show
2438 the system's boot progress on some display (for
2439 example, some LED's) on your board. At the moment,
2440 the following checkpoints are implemented:
2442 - Detailed boot stage timing
2444 Define this option to get detailed timing of each stage
2445 of the boot process.
2447 CONFIG_BOOTSTAGE_USER_COUNT
2448 This is the number of available user bootstage records.
2449 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2450 a new ID will be allocated from this stash. If you exceed
2451 the limit, recording will stop.
2453 CONFIG_BOOTSTAGE_REPORT
2454 Define this to print a report before boot, similar to this:
2456 Timer summary in microseconds:
2459 3,575,678 3,575,678 board_init_f start
2460 3,575,695 17 arch_cpu_init A9
2461 3,575,777 82 arch_cpu_init done
2462 3,659,598 83,821 board_init_r start
2463 3,910,375 250,777 main_loop
2464 29,916,167 26,005,792 bootm_start
2465 30,361,327 445,160 start_kernel
2467 CONFIG_CMD_BOOTSTAGE
2468 Add a 'bootstage' command which supports printing a report
2469 and un/stashing of bootstage data.
2471 CONFIG_BOOTSTAGE_FDT
2472 Stash the bootstage information in the FDT. A root 'bootstage'
2473 node is created with each bootstage id as a child. Each child
2474 has a 'name' property and either 'mark' containing the
2475 mark time in microsecond, or 'accum' containing the
2476 accumulated time for that bootstage id in microseconds.
2481 name = "board_init_f";
2490 Code in the Linux kernel can find this in /proc/devicetree.
2492 Legacy uImage format:
2495 1 common/cmd_bootm.c before attempting to boot an image
2496 -1 common/cmd_bootm.c Image header has bad magic number
2497 2 common/cmd_bootm.c Image header has correct magic number
2498 -2 common/cmd_bootm.c Image header has bad checksum
2499 3 common/cmd_bootm.c Image header has correct checksum
2500 -3 common/cmd_bootm.c Image data has bad checksum
2501 4 common/cmd_bootm.c Image data has correct checksum
2502 -4 common/cmd_bootm.c Image is for unsupported architecture
2503 5 common/cmd_bootm.c Architecture check OK
2504 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2505 6 common/cmd_bootm.c Image Type check OK
2506 -6 common/cmd_bootm.c gunzip uncompression error
2507 -7 common/cmd_bootm.c Unimplemented compression type
2508 7 common/cmd_bootm.c Uncompression OK
2509 8 common/cmd_bootm.c No uncompress/copy overwrite error
2510 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2512 9 common/image.c Start initial ramdisk verification
2513 -10 common/image.c Ramdisk header has bad magic number
2514 -11 common/image.c Ramdisk header has bad checksum
2515 10 common/image.c Ramdisk header is OK
2516 -12 common/image.c Ramdisk data has bad checksum
2517 11 common/image.c Ramdisk data has correct checksum
2518 12 common/image.c Ramdisk verification complete, start loading
2519 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2520 13 common/image.c Start multifile image verification
2521 14 common/image.c No initial ramdisk, no multifile, continue.
2523 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2525 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2526 -31 post/post.c POST test failed, detected by post_output_backlog()
2527 -32 post/post.c POST test failed, detected by post_run_single()
2529 34 common/cmd_doc.c before loading a Image from a DOC device
2530 -35 common/cmd_doc.c Bad usage of "doc" command
2531 35 common/cmd_doc.c correct usage of "doc" command
2532 -36 common/cmd_doc.c No boot device
2533 36 common/cmd_doc.c correct boot device
2534 -37 common/cmd_doc.c Unknown Chip ID on boot device
2535 37 common/cmd_doc.c correct chip ID found, device available
2536 -38 common/cmd_doc.c Read Error on boot device
2537 38 common/cmd_doc.c reading Image header from DOC device OK
2538 -39 common/cmd_doc.c Image header has bad magic number
2539 39 common/cmd_doc.c Image header has correct magic number
2540 -40 common/cmd_doc.c Error reading Image from DOC device
2541 40 common/cmd_doc.c Image header has correct magic number
2542 41 common/cmd_ide.c before loading a Image from a IDE device
2543 -42 common/cmd_ide.c Bad usage of "ide" command
2544 42 common/cmd_ide.c correct usage of "ide" command
2545 -43 common/cmd_ide.c No boot device
2546 43 common/cmd_ide.c boot device found
2547 -44 common/cmd_ide.c Device not available
2548 44 common/cmd_ide.c Device available
2549 -45 common/cmd_ide.c wrong partition selected
2550 45 common/cmd_ide.c partition selected
2551 -46 common/cmd_ide.c Unknown partition table
2552 46 common/cmd_ide.c valid partition table found
2553 -47 common/cmd_ide.c Invalid partition type
2554 47 common/cmd_ide.c correct partition type
2555 -48 common/cmd_ide.c Error reading Image Header on boot device
2556 48 common/cmd_ide.c reading Image Header from IDE device OK
2557 -49 common/cmd_ide.c Image header has bad magic number
2558 49 common/cmd_ide.c Image header has correct magic number
2559 -50 common/cmd_ide.c Image header has bad checksum
2560 50 common/cmd_ide.c Image header has correct checksum
2561 -51 common/cmd_ide.c Error reading Image from IDE device
2562 51 common/cmd_ide.c reading Image from IDE device OK
2563 52 common/cmd_nand.c before loading a Image from a NAND device
2564 -53 common/cmd_nand.c Bad usage of "nand" command
2565 53 common/cmd_nand.c correct usage of "nand" command
2566 -54 common/cmd_nand.c No boot device
2567 54 common/cmd_nand.c boot device found
2568 -55 common/cmd_nand.c Unknown Chip ID on boot device
2569 55 common/cmd_nand.c correct chip ID found, device available
2570 -56 common/cmd_nand.c Error reading Image Header on boot device
2571 56 common/cmd_nand.c reading Image Header from NAND device OK
2572 -57 common/cmd_nand.c Image header has bad magic number
2573 57 common/cmd_nand.c Image header has correct magic number
2574 -58 common/cmd_nand.c Error reading Image from NAND device
2575 58 common/cmd_nand.c reading Image from NAND device OK
2577 -60 common/env_common.c Environment has a bad CRC, using default
2579 64 net/eth.c starting with Ethernet configuration.
2580 -64 net/eth.c no Ethernet found.
2581 65 net/eth.c Ethernet found.
2583 -80 common/cmd_net.c usage wrong
2584 80 common/cmd_net.c before calling NetLoop()
2585 -81 common/cmd_net.c some error in NetLoop() occurred
2586 81 common/cmd_net.c NetLoop() back without error
2587 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2588 82 common/cmd_net.c trying automatic boot
2589 83 common/cmd_net.c running "source" command
2590 -83 common/cmd_net.c some error in automatic boot or "source" command
2591 84 common/cmd_net.c end without errors
2596 100 common/cmd_bootm.c Kernel FIT Image has correct format
2597 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2598 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2599 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2600 102 common/cmd_bootm.c Kernel unit name specified
2601 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2602 103 common/cmd_bootm.c Found configuration node
2603 104 common/cmd_bootm.c Got kernel subimage node offset
2604 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2605 105 common/cmd_bootm.c Kernel subimage hash verification OK
2606 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2607 106 common/cmd_bootm.c Architecture check OK
2608 -106 common/cmd_bootm.c Kernel subimage has wrong type
2609 107 common/cmd_bootm.c Kernel subimage type OK
2610 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2611 108 common/cmd_bootm.c Got kernel subimage data/size
2612 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2613 -109 common/cmd_bootm.c Can't get kernel subimage type
2614 -110 common/cmd_bootm.c Can't get kernel subimage comp
2615 -111 common/cmd_bootm.c Can't get kernel subimage os
2616 -112 common/cmd_bootm.c Can't get kernel subimage load address
2617 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2619 120 common/image.c Start initial ramdisk verification
2620 -120 common/image.c Ramdisk FIT image has incorrect format
2621 121 common/image.c Ramdisk FIT image has correct format
2622 122 common/image.c No ramdisk subimage unit name, using configuration
2623 -122 common/image.c Can't get configuration for ramdisk subimage
2624 123 common/image.c Ramdisk unit name specified
2625 -124 common/image.c Can't get ramdisk subimage node offset
2626 125 common/image.c Got ramdisk subimage node offset
2627 -125 common/image.c Ramdisk subimage hash verification failed
2628 126 common/image.c Ramdisk subimage hash verification OK
2629 -126 common/image.c Ramdisk subimage for unsupported architecture
2630 127 common/image.c Architecture check OK
2631 -127 common/image.c Can't get ramdisk subimage data/size
2632 128 common/image.c Got ramdisk subimage data/size
2633 129 common/image.c Can't get ramdisk load address
2634 -129 common/image.c Got ramdisk load address
2636 -130 common/cmd_doc.c Incorrect FIT image format
2637 131 common/cmd_doc.c FIT image format OK
2639 -140 common/cmd_ide.c Incorrect FIT image format
2640 141 common/cmd_ide.c FIT image format OK
2642 -150 common/cmd_nand.c Incorrect FIT image format
2643 151 common/cmd_nand.c FIT image format OK
2645 - FIT image support:
2647 Enable support for the FIT uImage format.
2649 CONFIG_FIT_BEST_MATCH
2650 When no configuration is explicitly selected, default to the
2651 one whose fdt's compatibility field best matches that of
2652 U-Boot itself. A match is considered "best" if it matches the
2653 most specific compatibility entry of U-Boot's fdt's root node.
2654 The order of entries in the configuration's fdt is ignored.
2656 - Standalone program support:
2657 CONFIG_STANDALONE_LOAD_ADDR
2659 This option defines a board specific value for the
2660 address where standalone program gets loaded, thus
2661 overwriting the architecture dependent default
2664 - Frame Buffer Address:
2667 Define CONFIG_FB_ADDR if you want to use specific
2668 address for frame buffer.
2669 Then system will reserve the frame buffer address to
2670 defined address instead of lcd_setmem (this function
2671 grabs the memory for frame buffer by panel's size).
2673 Please see board_init_f function.
2675 - Automatic software updates via TFTP server
2677 CONFIG_UPDATE_TFTP_CNT_MAX
2678 CONFIG_UPDATE_TFTP_MSEC_MAX
2680 These options enable and control the auto-update feature;
2681 for a more detailed description refer to doc/README.update.
2683 - MTD Support (mtdparts command, UBI support)
2686 Adds the MTD device infrastructure from the Linux kernel.
2687 Needed for mtdparts command support.
2689 CONFIG_MTD_PARTITIONS
2691 Adds the MTD partitioning infrastructure from the Linux
2692 kernel. Needed for UBI support.
2696 Enable building of SPL globally.
2699 LDSCRIPT for linking the SPL binary.
2702 Maximum binary size (text, data and rodata) of the SPL binary.
2704 CONFIG_SPL_TEXT_BASE
2705 TEXT_BASE for linking the SPL binary.
2707 CONFIG_SPL_RELOC_TEXT_BASE
2708 Address to relocate to. If unspecified, this is equal to
2709 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2711 CONFIG_SPL_BSS_START_ADDR
2712 Link address for the BSS within the SPL binary.
2714 CONFIG_SPL_BSS_MAX_SIZE
2715 Maximum binary size of the BSS section of the SPL binary.
2718 Adress of the start of the stack SPL will use
2720 CONFIG_SPL_RELOC_STACK
2721 Adress of the start of the stack SPL will use after
2722 relocation. If unspecified, this is equal to
2725 CONFIG_SYS_SPL_MALLOC_START
2726 Starting address of the malloc pool used in SPL.
2728 CONFIG_SYS_SPL_MALLOC_SIZE
2729 The size of the malloc pool used in SPL.
2731 CONFIG_SPL_FRAMEWORK
2732 Enable the SPL framework under common/. This framework
2733 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2734 NAND loading of the Linux Kernel.
2736 CONFIG_SPL_DISPLAY_PRINT
2737 For ARM, enable an optional function to print more information
2738 about the running system.
2740 CONFIG_SPL_INIT_MINIMAL
2741 Arch init code should be built for a very small image
2743 CONFIG_SPL_LIBCOMMON_SUPPORT
2744 Support for common/libcommon.o in SPL binary
2746 CONFIG_SPL_LIBDISK_SUPPORT
2747 Support for disk/libdisk.o in SPL binary
2749 CONFIG_SPL_I2C_SUPPORT
2750 Support for drivers/i2c/libi2c.o in SPL binary
2752 CONFIG_SPL_GPIO_SUPPORT
2753 Support for drivers/gpio/libgpio.o in SPL binary
2755 CONFIG_SPL_MMC_SUPPORT
2756 Support for drivers/mmc/libmmc.o in SPL binary
2758 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2759 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2760 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2761 Address, size and partition on the MMC to load U-Boot from
2762 when the MMC is being used in raw mode.
2764 CONFIG_SPL_FAT_SUPPORT
2765 Support for fs/fat/libfat.o in SPL binary
2767 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2768 Filename to read to load U-Boot when reading from FAT
2770 CONFIG_SPL_NAND_BASE
2771 Include nand_base.c in the SPL. Requires
2772 CONFIG_SPL_NAND_DRIVERS.
2774 CONFIG_SPL_NAND_DRIVERS
2775 SPL uses normal NAND drivers, not minimal drivers.
2778 Include standard software ECC in the SPL
2780 CONFIG_SPL_NAND_SIMPLE
2781 Support for NAND boot using simple NAND drivers that
2782 expose the cmd_ctrl() interface.
2784 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2785 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2786 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2787 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2788 CONFIG_SYS_NAND_ECCBYTES
2789 Defines the size and behavior of the NAND that SPL uses
2792 CONFIG_SYS_NAND_U_BOOT_OFFS
2793 Location in NAND to read U-Boot from
2795 CONFIG_SYS_NAND_U_BOOT_DST
2796 Location in memory to load U-Boot to
2798 CONFIG_SYS_NAND_U_BOOT_SIZE
2799 Size of image to load
2801 CONFIG_SYS_NAND_U_BOOT_START
2802 Entry point in loaded image to jump to
2804 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2805 Define this if you need to first read the OOB and then the
2806 data. This is used for example on davinci plattforms.
2808 CONFIG_SPL_OMAP3_ID_NAND
2809 Support for an OMAP3-specific set of functions to return the
2810 ID and MFR of the first attached NAND chip, if present.
2812 CONFIG_SPL_SERIAL_SUPPORT
2813 Support for drivers/serial/libserial.o in SPL binary
2815 CONFIG_SPL_SPI_FLASH_SUPPORT
2816 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2818 CONFIG_SPL_SPI_SUPPORT
2819 Support for drivers/spi/libspi.o in SPL binary
2821 CONFIG_SPL_RAM_DEVICE
2822 Support for running image already present in ram, in SPL binary
2824 CONFIG_SPL_LIBGENERIC_SUPPORT
2825 Support for lib/libgeneric.o in SPL binary
2828 Final target image containing SPL and payload. Some SPLs
2829 use an arch-specific makefile fragment instead, for
2830 example if more than one image needs to be produced.
2835 [so far only for SMDK2400 boards]
2837 - Modem support enable:
2838 CONFIG_MODEM_SUPPORT
2840 - RTS/CTS Flow control enable:
2843 - Modem debug support:
2844 CONFIG_MODEM_SUPPORT_DEBUG
2846 Enables debugging stuff (char screen[1024], dbg())
2847 for modem support. Useful only with BDI2000.
2849 - Interrupt support (PPC):
2851 There are common interrupt_init() and timer_interrupt()
2852 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2853 for CPU specific initialization. interrupt_init_cpu()
2854 should set decrementer_count to appropriate value. If
2855 CPU resets decrementer automatically after interrupt
2856 (ppc4xx) it should set decrementer_count to zero.
2857 timer_interrupt() calls timer_interrupt_cpu() for CPU
2858 specific handling. If board has watchdog / status_led
2859 / other_activity_monitor it works automatically from
2860 general timer_interrupt().
2864 In the target system modem support is enabled when a
2865 specific key (key combination) is pressed during
2866 power-on. Otherwise U-Boot will boot normally
2867 (autoboot). The key_pressed() function is called from
2868 board_init(). Currently key_pressed() is a dummy
2869 function, returning 1 and thus enabling modem
2872 If there are no modem init strings in the
2873 environment, U-Boot proceed to autoboot; the
2874 previous output (banner, info printfs) will be
2877 See also: doc/README.Modem
2879 Board initialization settings:
2880 ------------------------------
2882 During Initialization u-boot calls a number of board specific functions
2883 to allow the preparation of board specific prerequisites, e.g. pin setup
2884 before drivers are initialized. To enable these callbacks the
2885 following configuration macros have to be defined. Currently this is
2886 architecture specific, so please check arch/your_architecture/lib/board.c
2887 typically in board_init_f() and board_init_r().
2889 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2890 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2891 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2892 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2894 Configuration Settings:
2895 -----------------------
2897 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2898 undefine this when you're short of memory.
2900 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2901 width of the commands listed in the 'help' command output.
2903 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2904 prompt for user input.
2906 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2908 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2910 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2912 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2913 the application (usually a Linux kernel) when it is
2916 - CONFIG_SYS_BAUDRATE_TABLE:
2917 List of legal baudrate settings for this board.
2919 - CONFIG_SYS_CONSOLE_INFO_QUIET
2920 Suppress display of console information at boot.
2922 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2923 If the board specific function
2924 extern int overwrite_console (void);
2925 returns 1, the stdin, stderr and stdout are switched to the
2926 serial port, else the settings in the environment are used.
2928 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2929 Enable the call to overwrite_console().
2931 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2932 Enable overwrite of previous console environment settings.
2934 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2935 Begin and End addresses of the area used by the
2938 - CONFIG_SYS_ALT_MEMTEST:
2939 Enable an alternate, more extensive memory test.
2941 - CONFIG_SYS_MEMTEST_SCRATCH:
2942 Scratch address used by the alternate memory test
2943 You only need to set this if address zero isn't writeable
2945 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2946 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2947 this specified memory area will get subtracted from the top
2948 (end) of RAM and won't get "touched" at all by U-Boot. By
2949 fixing up gd->ram_size the Linux kernel should gets passed
2950 the now "corrected" memory size and won't touch it either.
2951 This should work for arch/ppc and arch/powerpc. Only Linux
2952 board ports in arch/powerpc with bootwrapper support that
2953 recalculate the memory size from the SDRAM controller setup
2954 will have to get fixed in Linux additionally.
2956 This option can be used as a workaround for the 440EPx/GRx
2957 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2960 WARNING: Please make sure that this value is a multiple of
2961 the Linux page size (normally 4k). If this is not the case,
2962 then the end address of the Linux memory will be located at a
2963 non page size aligned address and this could cause major
2966 - CONFIG_SYS_TFTP_LOADADDR:
2967 Default load address for network file downloads
2969 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2970 Enable temporary baudrate change while serial download
2972 - CONFIG_SYS_SDRAM_BASE:
2973 Physical start address of SDRAM. _Must_ be 0 here.
2975 - CONFIG_SYS_MBIO_BASE:
2976 Physical start address of Motherboard I/O (if using a
2979 - CONFIG_SYS_FLASH_BASE:
2980 Physical start address of Flash memory.
2982 - CONFIG_SYS_MONITOR_BASE:
2983 Physical start address of boot monitor code (set by
2984 make config files to be same as the text base address
2985 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2986 CONFIG_SYS_FLASH_BASE when booting from flash.
2988 - CONFIG_SYS_MONITOR_LEN:
2989 Size of memory reserved for monitor code, used to
2990 determine _at_compile_time_ (!) if the environment is
2991 embedded within the U-Boot image, or in a separate
2994 - CONFIG_SYS_MALLOC_LEN:
2995 Size of DRAM reserved for malloc() use.
2997 - CONFIG_SYS_BOOTM_LEN:
2998 Normally compressed uImages are limited to an
2999 uncompressed size of 8 MBytes. If this is not enough,
3000 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3001 to adjust this setting to your needs.
3003 - CONFIG_SYS_BOOTMAPSZ:
3004 Maximum size of memory mapped by the startup code of
3005 the Linux kernel; all data that must be processed by
3006 the Linux kernel (bd_info, boot arguments, FDT blob if
3007 used) must be put below this limit, unless "bootm_low"
3008 enviroment variable is defined and non-zero. In such case
3009 all data for the Linux kernel must be between "bootm_low"
3010 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3011 variable "bootm_mapsize" will override the value of
3012 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3013 then the value in "bootm_size" will be used instead.
3015 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3016 Enable initrd_high functionality. If defined then the
3017 initrd_high feature is enabled and the bootm ramdisk subcommand
3020 - CONFIG_SYS_BOOT_GET_CMDLINE:
3021 Enables allocating and saving kernel cmdline in space between
3022 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3024 - CONFIG_SYS_BOOT_GET_KBD:
3025 Enables allocating and saving a kernel copy of the bd_info in
3026 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3028 - CONFIG_SYS_MAX_FLASH_BANKS:
3029 Max number of Flash memory banks
3031 - CONFIG_SYS_MAX_FLASH_SECT:
3032 Max number of sectors on a Flash chip
3034 - CONFIG_SYS_FLASH_ERASE_TOUT:
3035 Timeout for Flash erase operations (in ms)
3037 - CONFIG_SYS_FLASH_WRITE_TOUT:
3038 Timeout for Flash write operations (in ms)
3040 - CONFIG_SYS_FLASH_LOCK_TOUT
3041 Timeout for Flash set sector lock bit operation (in ms)
3043 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3044 Timeout for Flash clear lock bits operation (in ms)
3046 - CONFIG_SYS_FLASH_PROTECTION
3047 If defined, hardware flash sectors protection is used
3048 instead of U-Boot software protection.
3050 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3052 Enable TFTP transfers directly to flash memory;
3053 without this option such a download has to be
3054 performed in two steps: (1) download to RAM, and (2)
3055 copy from RAM to flash.
3057 The two-step approach is usually more reliable, since
3058 you can check if the download worked before you erase
3059 the flash, but in some situations (when system RAM is
3060 too limited to allow for a temporary copy of the
3061 downloaded image) this option may be very useful.
3063 - CONFIG_SYS_FLASH_CFI:
3064 Define if the flash driver uses extra elements in the
3065 common flash structure for storing flash geometry.
3067 - CONFIG_FLASH_CFI_DRIVER
3068 This option also enables the building of the cfi_flash driver
3069 in the drivers directory
3071 - CONFIG_FLASH_CFI_MTD
3072 This option enables the building of the cfi_mtd driver
3073 in the drivers directory. The driver exports CFI flash
3076 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3077 Use buffered writes to flash.
3079 - CONFIG_FLASH_SPANSION_S29WS_N
3080 s29ws-n MirrorBit flash has non-standard addresses for buffered
3083 - CONFIG_SYS_FLASH_QUIET_TEST
3084 If this option is defined, the common CFI flash doesn't
3085 print it's warning upon not recognized FLASH banks. This
3086 is useful, if some of the configured banks are only
3087 optionally available.
3089 - CONFIG_FLASH_SHOW_PROGRESS
3090 If defined (must be an integer), print out countdown
3091 digits and dots. Recommended value: 45 (9..1) for 80
3092 column displays, 15 (3..1) for 40 column displays.
3094 - CONFIG_SYS_RX_ETH_BUFFER:
3095 Defines the number of Ethernet receive buffers. On some
3096 Ethernet controllers it is recommended to set this value
3097 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3098 buffers can be full shortly after enabling the interface
3099 on high Ethernet traffic.
3100 Defaults to 4 if not defined.
3102 - CONFIG_ENV_MAX_ENTRIES
3104 Maximum number of entries in the hash table that is used
3105 internally to store the environment settings. The default
3106 setting is supposed to be generous and should work in most
3107 cases. This setting can be used to tune behaviour; see
3108 lib/hashtable.c for details.
3110 The following definitions that deal with the placement and management
3111 of environment data (variable area); in general, we support the
3112 following configurations:
3114 - CONFIG_BUILD_ENVCRC:
3116 Builds up envcrc with the target environment so that external utils
3117 may easily extract it and embed it in final U-Boot images.
3119 - CONFIG_ENV_IS_IN_FLASH:
3121 Define this if the environment is in flash memory.
3123 a) The environment occupies one whole flash sector, which is
3124 "embedded" in the text segment with the U-Boot code. This
3125 happens usually with "bottom boot sector" or "top boot
3126 sector" type flash chips, which have several smaller
3127 sectors at the start or the end. For instance, such a
3128 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3129 such a case you would place the environment in one of the
3130 4 kB sectors - with U-Boot code before and after it. With
3131 "top boot sector" type flash chips, you would put the
3132 environment in one of the last sectors, leaving a gap
3133 between U-Boot and the environment.
3135 - CONFIG_ENV_OFFSET:
3137 Offset of environment data (variable area) to the
3138 beginning of flash memory; for instance, with bottom boot
3139 type flash chips the second sector can be used: the offset
3140 for this sector is given here.
3142 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3146 This is just another way to specify the start address of
3147 the flash sector containing the environment (instead of
3150 - CONFIG_ENV_SECT_SIZE:
3152 Size of the sector containing the environment.
3155 b) Sometimes flash chips have few, equal sized, BIG sectors.
3156 In such a case you don't want to spend a whole sector for
3161 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3162 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3163 of this flash sector for the environment. This saves
3164 memory for the RAM copy of the environment.
3166 It may also save flash memory if you decide to use this
3167 when your environment is "embedded" within U-Boot code,
3168 since then the remainder of the flash sector could be used
3169 for U-Boot code. It should be pointed out that this is
3170 STRONGLY DISCOURAGED from a robustness point of view:
3171 updating the environment in flash makes it always
3172 necessary to erase the WHOLE sector. If something goes
3173 wrong before the contents has been restored from a copy in
3174 RAM, your target system will be dead.
3176 - CONFIG_ENV_ADDR_REDUND
3177 CONFIG_ENV_SIZE_REDUND
3179 These settings describe a second storage area used to hold
3180 a redundant copy of the environment data, so that there is
3181 a valid backup copy in case there is a power failure during
3182 a "saveenv" operation.
3184 BE CAREFUL! Any changes to the flash layout, and some changes to the
3185 source code will make it necessary to adapt <board>/u-boot.lds*
3189 - CONFIG_ENV_IS_IN_NVRAM:
3191 Define this if you have some non-volatile memory device
3192 (NVRAM, battery buffered SRAM) which you want to use for the
3198 These two #defines are used to determine the memory area you
3199 want to use for environment. It is assumed that this memory
3200 can just be read and written to, without any special
3203 BE CAREFUL! The first access to the environment happens quite early
3204 in U-Boot initalization (when we try to get the setting of for the
3205 console baudrate). You *MUST* have mapped your NVRAM area then, or
3208 Please note that even with NVRAM we still use a copy of the
3209 environment in RAM: we could work on NVRAM directly, but we want to
3210 keep settings there always unmodified except somebody uses "saveenv"
3211 to save the current settings.
3214 - CONFIG_ENV_IS_IN_EEPROM:
3216 Use this if you have an EEPROM or similar serial access
3217 device and a driver for it.
3219 - CONFIG_ENV_OFFSET:
3222 These two #defines specify the offset and size of the
3223 environment area within the total memory of your EEPROM.
3225 - CONFIG_SYS_I2C_EEPROM_ADDR:
3226 If defined, specified the chip address of the EEPROM device.
3227 The default address is zero.
3229 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3230 If defined, the number of bits used to address bytes in a
3231 single page in the EEPROM device. A 64 byte page, for example
3232 would require six bits.
3234 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3235 If defined, the number of milliseconds to delay between
3236 page writes. The default is zero milliseconds.
3238 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3239 The length in bytes of the EEPROM memory array address. Note
3240 that this is NOT the chip address length!
3242 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3243 EEPROM chips that implement "address overflow" are ones
3244 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3245 address and the extra bits end up in the "chip address" bit
3246 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3249 Note that we consider the length of the address field to
3250 still be one byte because the extra address bits are hidden
3251 in the chip address.
3253 - CONFIG_SYS_EEPROM_SIZE:
3254 The size in bytes of the EEPROM device.
3256 - CONFIG_ENV_EEPROM_IS_ON_I2C
3257 define this, if you have I2C and SPI activated, and your
3258 EEPROM, which holds the environment, is on the I2C bus.
3260 - CONFIG_I2C_ENV_EEPROM_BUS
3261 if you have an Environment on an EEPROM reached over
3262 I2C muxes, you can define here, how to reach this
3263 EEPROM. For example:
3265 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3267 EEPROM which holds the environment, is reached over
3268 a pca9547 i2c mux with address 0x70, channel 3.
3270 - CONFIG_ENV_IS_IN_DATAFLASH:
3272 Define this if you have a DataFlash memory device which you
3273 want to use for the environment.
3275 - CONFIG_ENV_OFFSET:
3279 These three #defines specify the offset and size of the
3280 environment area within the total memory of your DataFlash placed
3281 at the specified address.
3283 - CONFIG_ENV_IS_IN_REMOTE:
3285 Define this if you have a remote memory space which you
3286 want to use for the local device's environment.
3291 These two #defines specify the address and size of the
3292 environment area within the remote memory space. The
3293 local device can get the environment from remote memory
3294 space by SRIO or PCIE links.
3296 BE CAREFUL! For some special cases, the local device can not use
3297 "saveenv" command. For example, the local device will get the
3298 environment stored in a remote NOR flash by SRIO or PCIE link,
3299 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3301 - CONFIG_ENV_IS_IN_NAND:
3303 Define this if you have a NAND device which you want to use
3304 for the environment.
3306 - CONFIG_ENV_OFFSET:
3309 These two #defines specify the offset and size of the environment
3310 area within the first NAND device. CONFIG_ENV_OFFSET must be
3311 aligned to an erase block boundary.
3313 - CONFIG_ENV_OFFSET_REDUND (optional):
3315 This setting describes a second storage area of CONFIG_ENV_SIZE
3316 size used to hold a redundant copy of the environment data, so
3317 that there is a valid backup copy in case there is a power failure
3318 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3319 aligned to an erase block boundary.
3321 - CONFIG_ENV_RANGE (optional):
3323 Specifies the length of the region in which the environment
3324 can be written. This should be a multiple of the NAND device's
3325 block size. Specifying a range with more erase blocks than
3326 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3327 the range to be avoided.
3329 - CONFIG_ENV_OFFSET_OOB (optional):
3331 Enables support for dynamically retrieving the offset of the
3332 environment from block zero's out-of-band data. The
3333 "nand env.oob" command can be used to record this offset.
3334 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3335 using CONFIG_ENV_OFFSET_OOB.
3337 - CONFIG_NAND_ENV_DST
3339 Defines address in RAM to which the nand_spl code should copy the
3340 environment. If redundant environment is used, it will be copied to
3341 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3343 - CONFIG_SYS_SPI_INIT_OFFSET
3345 Defines offset to the initial SPI buffer area in DPRAM. The
3346 area is used at an early stage (ROM part) if the environment
3347 is configured to reside in the SPI EEPROM: We need a 520 byte
3348 scratch DPRAM area. It is used between the two initialization
3349 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3350 to be a good choice since it makes it far enough from the
3351 start of the data area as well as from the stack pointer.
3353 Please note that the environment is read-only until the monitor
3354 has been relocated to RAM and a RAM copy of the environment has been
3355 created; also, when using EEPROM you will have to use getenv_f()
3356 until then to read environment variables.
3358 The environment is protected by a CRC32 checksum. Before the monitor
3359 is relocated into RAM, as a result of a bad CRC you will be working
3360 with the compiled-in default environment - *silently*!!! [This is
3361 necessary, because the first environment variable we need is the
3362 "baudrate" setting for the console - if we have a bad CRC, we don't
3363 have any device yet where we could complain.]
3365 Note: once the monitor has been relocated, then it will complain if
3366 the default environment is used; a new CRC is computed as soon as you
3367 use the "saveenv" command to store a valid environment.
3369 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3370 Echo the inverted Ethernet link state to the fault LED.
3372 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3373 also needs to be defined.
3375 - CONFIG_SYS_FAULT_MII_ADDR:
3376 MII address of the PHY to check for the Ethernet link state.
3378 - CONFIG_NS16550_MIN_FUNCTIONS:
3379 Define this if you desire to only have use of the NS16550_init
3380 and NS16550_putc functions for the serial driver located at
3381 drivers/serial/ns16550.c. This option is useful for saving
3382 space for already greatly restricted images, including but not
3383 limited to NAND_SPL configurations.
3385 Low Level (hardware related) configuration options:
3386 ---------------------------------------------------
3388 - CONFIG_SYS_CACHELINE_SIZE:
3389 Cache Line Size of the CPU.
3391 - CONFIG_SYS_DEFAULT_IMMR:
3392 Default address of the IMMR after system reset.
3394 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3395 and RPXsuper) to be able to adjust the position of
3396 the IMMR register after a reset.
3398 - CONFIG_SYS_CCSRBAR_DEFAULT:
3399 Default (power-on reset) physical address of CCSR on Freescale
3402 - CONFIG_SYS_CCSRBAR:
3403 Virtual address of CCSR. On a 32-bit build, this is typically
3404 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3406 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3407 for cross-platform code that uses that macro instead.
3409 - CONFIG_SYS_CCSRBAR_PHYS:
3410 Physical address of CCSR. CCSR can be relocated to a new
3411 physical address, if desired. In this case, this macro should
3412 be set to that address. Otherwise, it should be set to the
3413 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3414 is typically relocated on 36-bit builds. It is recommended
3415 that this macro be defined via the _HIGH and _LOW macros:
3417 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3418 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3420 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3421 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3422 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3423 used in assembly code, so it must not contain typecasts or
3424 integer size suffixes (e.g. "ULL").
3426 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3427 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3428 used in assembly code, so it must not contain typecasts or
3429 integer size suffixes (e.g. "ULL").
3431 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3432 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3433 forced to a value that ensures that CCSR is not relocated.
3435 - Floppy Disk Support:
3436 CONFIG_SYS_FDC_DRIVE_NUMBER
3438 the default drive number (default value 0)
3440 CONFIG_SYS_ISA_IO_STRIDE
3442 defines the spacing between FDC chipset registers
3445 CONFIG_SYS_ISA_IO_OFFSET
3447 defines the offset of register from address. It
3448 depends on which part of the data bus is connected to
3449 the FDC chipset. (default value 0)
3451 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3452 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3455 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3456 fdc_hw_init() is called at the beginning of the FDC
3457 setup. fdc_hw_init() must be provided by the board
3458 source code. It is used to make hardware dependant
3462 Most IDE controllers were designed to be connected with PCI
3463 interface. Only few of them were designed for AHB interface.
3464 When software is doing ATA command and data transfer to
3465 IDE devices through IDE-AHB controller, some additional
3466 registers accessing to these kind of IDE-AHB controller
3469 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3470 DO NOT CHANGE unless you know exactly what you're
3471 doing! (11-4) [MPC8xx/82xx systems only]
3473 - CONFIG_SYS_INIT_RAM_ADDR:
3475 Start address of memory area that can be used for
3476 initial data and stack; please note that this must be
3477 writable memory that is working WITHOUT special
3478 initialization, i. e. you CANNOT use normal RAM which
3479 will become available only after programming the
3480 memory controller and running certain initialization
3483 U-Boot uses the following memory types:
3484 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3485 - MPC824X: data cache
3486 - PPC4xx: data cache
3488 - CONFIG_SYS_GBL_DATA_OFFSET:
3490 Offset of the initial data structure in the memory
3491 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3492 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3493 data is located at the end of the available space
3494 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3495 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3496 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3497 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3500 On the MPC824X (or other systems that use the data
3501 cache for initial memory) the address chosen for
3502 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3503 point to an otherwise UNUSED address space between
3504 the top of RAM and the start of the PCI space.
3506 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3508 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3510 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3512 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3514 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3516 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3518 - CONFIG_SYS_OR_TIMING_SDRAM:
3521 - CONFIG_SYS_MAMR_PTA:
3522 periodic timer for refresh
3524 - CONFIG_SYS_DER: Debug Event Register (37-47)
3526 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3527 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3528 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3529 CONFIG_SYS_BR1_PRELIM:
3530 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3532 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3533 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3534 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3535 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3537 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3538 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3539 Machine Mode Register and Memory Periodic Timer
3540 Prescaler definitions (SDRAM timing)
3542 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3543 enable I2C microcode relocation patch (MPC8xx);
3544 define relocation offset in DPRAM [DSP2]
3546 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3547 enable SMC microcode relocation patch (MPC8xx);
3548 define relocation offset in DPRAM [SMC1]
3550 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3551 enable SPI microcode relocation patch (MPC8xx);
3552 define relocation offset in DPRAM [SCC4]
3554 - CONFIG_SYS_USE_OSCCLK:
3555 Use OSCM clock mode on MBX8xx board. Be careful,
3556 wrong setting might damage your board. Read
3557 doc/README.MBX before setting this variable!
3559 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3560 Offset of the bootmode word in DPRAM used by post
3561 (Power On Self Tests). This definition overrides
3562 #define'd default value in commproc.h resp.
3565 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3566 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3567 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3568 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3569 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3570 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3571 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3572 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3573 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3575 - CONFIG_PCI_DISABLE_PCIE:
3576 Disable PCI-Express on systems where it is supported but not
3579 - CONFIG_PCI_ENUM_ONLY
3580 Only scan through and get the devices on the busses.
3581 Don't do any setup work, presumably because someone or
3582 something has already done it, and we don't need to do it
3583 a second time. Useful for platforms that are pre-booted
3584 by coreboot or similar.
3587 Chip has SRIO or not
3590 Board has SRIO 1 port available
3593 Board has SRIO 2 port available
3595 - CONFIG_SYS_SRIOn_MEM_VIRT:
3596 Virtual Address of SRIO port 'n' memory region
3598 - CONFIG_SYS_SRIOn_MEM_PHYS:
3599 Physical Address of SRIO port 'n' memory region
3601 - CONFIG_SYS_SRIOn_MEM_SIZE:
3602 Size of SRIO port 'n' memory region
3604 - CONFIG_SYS_NDFC_16
3605 Defined to tell the NDFC that the NAND chip is using a
3608 - CONFIG_SYS_NDFC_EBC0_CFG
3609 Sets the EBC0_CFG register for the NDFC. If not defined
3610 a default value will be used.
3613 Get DDR timing information from an I2C EEPROM. Common
3614 with pluggable memory modules such as SODIMMs
3617 I2C address of the SPD EEPROM
3619 - CONFIG_SYS_SPD_BUS_NUM
3620 If SPD EEPROM is on an I2C bus other than the first
3621 one, specify here. Note that the value must resolve
3622 to something your driver can deal with.
3624 - CONFIG_SYS_DDR_RAW_TIMING
3625 Get DDR timing information from other than SPD. Common with
3626 soldered DDR chips onboard without SPD. DDR raw timing
3627 parameters are extracted from datasheet and hard-coded into
3628 header files or board specific files.
3630 - CONFIG_FSL_DDR_INTERACTIVE
3631 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3633 - CONFIG_SYS_83XX_DDR_USES_CS0
3634 Only for 83xx systems. If specified, then DDR should
3635 be configured using CS0 and CS1 instead of CS2 and CS3.
3637 - CONFIG_ETHER_ON_FEC[12]
3638 Define to enable FEC[12] on a 8xx series processor.
3640 - CONFIG_FEC[12]_PHY
3641 Define to the hardcoded PHY address which corresponds
3642 to the given FEC; i. e.
3643 #define CONFIG_FEC1_PHY 4
3644 means that the PHY with address 4 is connected to FEC1
3646 When set to -1, means to probe for first available.
3648 - CONFIG_FEC[12]_PHY_NORXERR
3649 The PHY does not have a RXERR line (RMII only).
3650 (so program the FEC to ignore it).
3653 Enable RMII mode for all FECs.
3654 Note that this is a global option, we can't
3655 have one FEC in standard MII mode and another in RMII mode.
3657 - CONFIG_CRC32_VERIFY
3658 Add a verify option to the crc32 command.
3661 => crc32 -v <address> <count> <crc32>
3663 Where address/count indicate a memory area
3664 and crc32 is the correct crc32 which the
3668 Add the "loopw" memory command. This only takes effect if
3669 the memory commands are activated globally (CONFIG_CMD_MEM).
3672 Add the "mdc" and "mwc" memory commands. These are cyclic
3677 This command will print 4 bytes (10,11,12,13) each 500 ms.
3679 => mwc.l 100 12345678 10
3680 This command will write 12345678 to address 100 all 10 ms.
3682 This only takes effect if the memory commands are activated
3683 globally (CONFIG_CMD_MEM).
3685 - CONFIG_SKIP_LOWLEVEL_INIT
3686 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3687 low level initializations (like setting up the memory
3688 controller) are omitted and/or U-Boot does not
3689 relocate itself into RAM.
3691 Normally this variable MUST NOT be defined. The only
3692 exception is when U-Boot is loaded (to RAM) by some
3693 other boot loader or by a debugger which performs
3694 these initializations itself.
3697 Modifies the behaviour of start.S when compiling a loader
3698 that is executed before the actual U-Boot. E.g. when
3699 compiling a NAND SPL.
3701 - CONFIG_USE_ARCH_MEMCPY
3702 CONFIG_USE_ARCH_MEMSET
3703 If these options are used a optimized version of memcpy/memset will
3704 be used if available. These functions may be faster under some
3705 conditions but may increase the binary size.
3707 - CONFIG_X86_NO_RESET_VECTOR
3708 If defined, the x86 reset vector code is excluded. You will need
3709 to do this when U-Boot is running from Coreboot.
3711 - CONFIG_X86_NO_REAL_MODE
3712 If defined, x86 real mode code is omitted. This assumes a
3713 32-bit environment where such code is not needed. You will
3714 need to do this when U-Boot is running from Coreboot.
3717 Freescale QE/FMAN Firmware Support:
3718 -----------------------------------
3720 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3721 loading of "firmware", which is encoded in the QE firmware binary format.
3722 This firmware often needs to be loaded during U-Boot booting, so macros
3723 are used to identify the storage device (NOR flash, SPI, etc) and the address
3726 - CONFIG_SYS_QE_FMAN_FW_ADDR
3727 The address in the storage device where the firmware is located. The
3728 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3731 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3732 The maximum possible size of the firmware. The firmware binary format
3733 has a field that specifies the actual size of the firmware, but it
3734 might not be possible to read any part of the firmware unless some
3735 local storage is allocated to hold the entire firmware first.
3737 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3738 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3739 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3740 virtual address in NOR flash.
3742 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3743 Specifies that QE/FMAN firmware is located in NAND flash.
3744 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3746 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3747 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3748 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3750 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3751 Specifies that QE/FMAN firmware is located on the primary SPI
3752 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3754 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3755 Specifies that QE/FMAN firmware is located in the remote (master)
3756 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3757 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3758 window->master inbound window->master LAW->the ucode address in
3759 master's memory space.
3761 Building the Software:
3762 ======================
3764 Building U-Boot has been tested in several native build environments
3765 and in many different cross environments. Of course we cannot support
3766 all possibly existing versions of cross development tools in all
3767 (potentially obsolete) versions. In case of tool chain problems we
3768 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3769 which is extensively used to build and test U-Boot.
3771 If you are not using a native environment, it is assumed that you
3772 have GNU cross compiling tools available in your path. In this case,
3773 you must set the environment variable CROSS_COMPILE in your shell.
3774 Note that no changes to the Makefile or any other source files are
3775 necessary. For example using the ELDK on a 4xx CPU, please enter:
3777 $ CROSS_COMPILE=ppc_4xx-
3778 $ export CROSS_COMPILE
3780 Note: If you wish to generate Windows versions of the utilities in
3781 the tools directory you can use the MinGW toolchain
3782 (http://www.mingw.org). Set your HOST tools to the MinGW
3783 toolchain and execute 'make tools'. For example:
3785 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3787 Binaries such as tools/mkimage.exe will be created which can
3788 be executed on computers running Windows.
3790 U-Boot is intended to be simple to build. After installing the
3791 sources you must configure U-Boot for one specific board type. This
3796 where "NAME_config" is the name of one of the existing configu-
3797 rations; see boards.cfg for supported names.
3799 Note: for some board special configuration names may exist; check if
3800 additional information is available from the board vendor; for
3801 instance, the TQM823L systems are available without (standard)
3802 or with LCD support. You can select such additional "features"
3803 when choosing the configuration, i. e.
3806 - will configure for a plain TQM823L, i. e. no LCD support
3808 make TQM823L_LCD_config
3809 - will configure for a TQM823L with U-Boot console on LCD
3814 Finally, type "make all", and you should get some working U-Boot
3815 images ready for download to / installation on your system:
3817 - "u-boot.bin" is a raw binary image
3818 - "u-boot" is an image in ELF binary format
3819 - "u-boot.srec" is in Motorola S-Record format
3821 By default the build is performed locally and the objects are saved
3822 in the source directory. One of the two methods can be used to change
3823 this behavior and build U-Boot to some external directory:
3825 1. Add O= to the make command line invocations:
3827 make O=/tmp/build distclean
3828 make O=/tmp/build NAME_config
3829 make O=/tmp/build all
3831 2. Set environment variable BUILD_DIR to point to the desired location:
3833 export BUILD_DIR=/tmp/build
3838 Note that the command line "O=" setting overrides the BUILD_DIR environment
3842 Please be aware that the Makefiles assume you are using GNU make, so
3843 for instance on NetBSD you might need to use "gmake" instead of
3847 If the system board that you have is not listed, then you will need
3848 to port U-Boot to your hardware platform. To do this, follow these
3851 1. Add a new configuration option for your board to the toplevel
3852 "boards.cfg" file, using the existing entries as examples.
3853 Follow the instructions there to keep the boards in order.
3854 2. Create a new directory to hold your board specific code. Add any
3855 files you need. In your board directory, you will need at least
3856 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3857 3. Create a new configuration file "include/configs/<board>.h" for
3859 3. If you're porting U-Boot to a new CPU, then also create a new
3860 directory to hold your CPU specific code. Add any files you need.
3861 4. Run "make <board>_config" with your new name.
3862 5. Type "make", and you should get a working "u-boot.srec" file
3863 to be installed on your target system.
3864 6. Debug and solve any problems that might arise.
3865 [Of course, this last step is much harder than it sounds.]
3868 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3869 ==============================================================
3871 If you have modified U-Boot sources (for instance added a new board
3872 or support for new devices, a new CPU, etc.) you are expected to
3873 provide feedback to the other developers. The feedback normally takes
3874 the form of a "patch", i. e. a context diff against a certain (latest
3875 official or latest in the git repository) version of U-Boot sources.
3877 But before you submit such a patch, please verify that your modifi-
3878 cation did not break existing code. At least make sure that *ALL* of
3879 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3880 just run the "MAKEALL" script, which will configure and build U-Boot
3881 for ALL supported system. Be warned, this will take a while. You can
3882 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3883 environment variable to the script, i. e. to use the ELDK cross tools
3886 CROSS_COMPILE=ppc_8xx- MAKEALL
3888 or to build on a native PowerPC system you can type
3890 CROSS_COMPILE=' ' MAKEALL
3892 When using the MAKEALL script, the default behaviour is to build
3893 U-Boot in the source directory. This location can be changed by
3894 setting the BUILD_DIR environment variable. Also, for each target
3895 built, the MAKEALL script saves two log files (<target>.ERR and
3896 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3897 location can be changed by setting the MAKEALL_LOGDIR environment
3898 variable. For example:
3900 export BUILD_DIR=/tmp/build
3901 export MAKEALL_LOGDIR=/tmp/log
3902 CROSS_COMPILE=ppc_8xx- MAKEALL
3904 With the above settings build objects are saved in the /tmp/build,
3905 log files are saved in the /tmp/log and the source tree remains clean
3906 during the whole build process.
3909 See also "U-Boot Porting Guide" below.
3912 Monitor Commands - Overview:
3913 ============================
3915 go - start application at address 'addr'
3916 run - run commands in an environment variable
3917 bootm - boot application image from memory
3918 bootp - boot image via network using BootP/TFTP protocol
3919 bootz - boot zImage from memory
3920 tftpboot- boot image via network using TFTP protocol
3921 and env variables "ipaddr" and "serverip"
3922 (and eventually "gatewayip")
3923 tftpput - upload a file via network using TFTP protocol
3924 rarpboot- boot image via network using RARP/TFTP protocol
3925 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3926 loads - load S-Record file over serial line
3927 loadb - load binary file over serial line (kermit mode)
3929 mm - memory modify (auto-incrementing)
3930 nm - memory modify (constant address)
3931 mw - memory write (fill)
3933 cmp - memory compare
3934 crc32 - checksum calculation
3935 i2c - I2C sub-system
3936 sspi - SPI utility commands
3937 base - print or set address offset
3938 printenv- print environment variables
3939 setenv - set environment variables
3940 saveenv - save environment variables to persistent storage
3941 protect - enable or disable FLASH write protection
3942 erase - erase FLASH memory
3943 flinfo - print FLASH memory information
3944 nand - NAND memory operations (see doc/README.nand)
3945 bdinfo - print Board Info structure
3946 iminfo - print header information for application image
3947 coninfo - print console devices and informations
3948 ide - IDE sub-system
3949 loop - infinite loop on address range
3950 loopw - infinite write loop on address range
3951 mtest - simple RAM test
3952 icache - enable or disable instruction cache
3953 dcache - enable or disable data cache
3954 reset - Perform RESET of the CPU
3955 echo - echo args to console
3956 version - print monitor version
3957 help - print online help
3958 ? - alias for 'help'
3961 Monitor Commands - Detailed Description:
3962 ========================================
3966 For now: just type "help <command>".
3969 Environment Variables:
3970 ======================
3972 U-Boot supports user configuration using Environment Variables which
3973 can be made persistent by saving to Flash memory.
3975 Environment Variables are set using "setenv", printed using
3976 "printenv", and saved to Flash using "saveenv". Using "setenv"
3977 without a value can be used to delete a variable from the
3978 environment. As long as you don't save the environment you are
3979 working with an in-memory copy. In case the Flash area containing the
3980 environment is erased by accident, a default environment is provided.
3982 Some configuration options can be set using Environment Variables.
3984 List of environment variables (most likely not complete):
3986 baudrate - see CONFIG_BAUDRATE
3988 bootdelay - see CONFIG_BOOTDELAY
3990 bootcmd - see CONFIG_BOOTCOMMAND
3992 bootargs - Boot arguments when booting an RTOS image
3994 bootfile - Name of the image to load with TFTP
3996 bootm_low - Memory range available for image processing in the bootm
3997 command can be restricted. This variable is given as
3998 a hexadecimal number and defines lowest address allowed
3999 for use by the bootm command. See also "bootm_size"
4000 environment variable. Address defined by "bootm_low" is
4001 also the base of the initial memory mapping for the Linux
4002 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4005 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4006 This variable is given as a hexadecimal number and it
4007 defines the size of the memory region starting at base
4008 address bootm_low that is accessible by the Linux kernel
4009 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4010 as the default value if it is defined, and bootm_size is
4013 bootm_size - Memory range available for image processing in the bootm
4014 command can be restricted. This variable is given as
4015 a hexadecimal number and defines the size of the region
4016 allowed for use by the bootm command. See also "bootm_low"
4017 environment variable.
4019 updatefile - Location of the software update file on a TFTP server, used
4020 by the automatic software update feature. Please refer to
4021 documentation in doc/README.update for more details.
4023 autoload - if set to "no" (any string beginning with 'n'),
4024 "bootp" will just load perform a lookup of the
4025 configuration from the BOOTP server, but not try to
4026 load any image using TFTP
4028 autostart - if set to "yes", an image loaded using the "bootp",
4029 "rarpboot", "tftpboot" or "diskboot" commands will
4030 be automatically started (by internally calling
4033 If set to "no", a standalone image passed to the
4034 "bootm" command will be copied to the load address
4035 (and eventually uncompressed), but NOT be started.
4036 This can be used to load and uncompress arbitrary
4039 fdt_high - if set this restricts the maximum address that the
4040 flattened device tree will be copied into upon boot.
4041 For example, if you have a system with 1 GB memory
4042 at physical address 0x10000000, while Linux kernel
4043 only recognizes the first 704 MB as low memory, you
4044 may need to set fdt_high as 0x3C000000 to have the
4045 device tree blob be copied to the maximum address
4046 of the 704 MB low memory, so that Linux kernel can
4047 access it during the boot procedure.
4049 If this is set to the special value 0xFFFFFFFF then
4050 the fdt will not be copied at all on boot. For this
4051 to work it must reside in writable memory, have
4052 sufficient padding on the end of it for u-boot to
4053 add the information it needs into it, and the memory
4054 must be accessible by the kernel.
4056 fdtcontroladdr- if set this is the address of the control flattened
4057 device tree used by U-Boot when CONFIG_OF_CONTROL is
4060 i2cfast - (PPC405GP|PPC405EP only)
4061 if set to 'y' configures Linux I2C driver for fast
4062 mode (400kHZ). This environment variable is used in
4063 initialization code. So, for changes to be effective
4064 it must be saved and board must be reset.
4066 initrd_high - restrict positioning of initrd images:
4067 If this variable is not set, initrd images will be
4068 copied to the highest possible address in RAM; this
4069 is usually what you want since it allows for
4070 maximum initrd size. If for some reason you want to
4071 make sure that the initrd image is loaded below the
4072 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4073 variable to a value of "no" or "off" or "0".
4074 Alternatively, you can set it to a maximum upper
4075 address to use (U-Boot will still check that it
4076 does not overwrite the U-Boot stack and data).
4078 For instance, when you have a system with 16 MB
4079 RAM, and want to reserve 4 MB from use by Linux,
4080 you can do this by adding "mem=12M" to the value of
4081 the "bootargs" variable. However, now you must make
4082 sure that the initrd image is placed in the first
4083 12 MB as well - this can be done with
4085 setenv initrd_high 00c00000
4087 If you set initrd_high to 0xFFFFFFFF, this is an
4088 indication to U-Boot that all addresses are legal
4089 for the Linux kernel, including addresses in flash
4090 memory. In this case U-Boot will NOT COPY the
4091 ramdisk at all. This may be useful to reduce the
4092 boot time on your system, but requires that this
4093 feature is supported by your Linux kernel.
4095 ipaddr - IP address; needed for tftpboot command
4097 loadaddr - Default load address for commands like "bootp",
4098 "rarpboot", "tftpboot", "loadb" or "diskboot"
4100 loads_echo - see CONFIG_LOADS_ECHO
4102 serverip - TFTP server IP address; needed for tftpboot command
4104 bootretry - see CONFIG_BOOT_RETRY_TIME
4106 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4108 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4110 ethprime - controls which interface is used first.
4112 ethact - controls which interface is currently active.
4113 For example you can do the following
4115 => setenv ethact FEC
4116 => ping 192.168.0.1 # traffic sent on FEC
4117 => setenv ethact SCC
4118 => ping 10.0.0.1 # traffic sent on SCC
4120 ethrotate - When set to "no" U-Boot does not go through all
4121 available network interfaces.
4122 It just stays at the currently selected interface.
4124 netretry - When set to "no" each network operation will
4125 either succeed or fail without retrying.
4126 When set to "once" the network operation will
4127 fail when all the available network interfaces
4128 are tried once without success.
4129 Useful on scripts which control the retry operation
4132 npe_ucode - set load address for the NPE microcode
4134 tftpsrcport - If this is set, the value is used for TFTP's
4137 tftpdstport - If this is set, the value is used for TFTP's UDP
4138 destination port instead of the Well Know Port 69.
4140 tftpblocksize - Block size to use for TFTP transfers; if not set,
4141 we use the TFTP server's default block size
4143 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4144 seconds, minimum value is 1000 = 1 second). Defines
4145 when a packet is considered to be lost so it has to
4146 be retransmitted. The default is 5000 = 5 seconds.
4147 Lowering this value may make downloads succeed
4148 faster in networks with high packet loss rates or
4149 with unreliable TFTP servers.
4151 vlan - When set to a value < 4095 the traffic over
4152 Ethernet is encapsulated/received over 802.1q
4155 The following image location variables contain the location of images
4156 used in booting. The "Image" column gives the role of the image and is
4157 not an environment variable name. The other columns are environment
4158 variable names. "File Name" gives the name of the file on a TFTP
4159 server, "RAM Address" gives the location in RAM the image will be
4160 loaded to, and "Flash Location" gives the image's address in NOR
4161 flash or offset in NAND flash.
4163 *Note* - these variables don't have to be defined for all boards, some
4164 boards currenlty use other variables for these purposes, and some
4165 boards use these variables for other purposes.
4167 Image File Name RAM Address Flash Location
4168 ----- --------- ----------- --------------
4169 u-boot u-boot u-boot_addr_r u-boot_addr
4170 Linux kernel bootfile kernel_addr_r kernel_addr
4171 device tree blob fdtfile fdt_addr_r fdt_addr
4172 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4174 The following environment variables may be used and automatically
4175 updated by the network boot commands ("bootp" and "rarpboot"),
4176 depending the information provided by your boot server:
4178 bootfile - see above
4179 dnsip - IP address of your Domain Name Server
4180 dnsip2 - IP address of your secondary Domain Name Server
4181 gatewayip - IP address of the Gateway (Router) to use
4182 hostname - Target hostname
4184 netmask - Subnet Mask
4185 rootpath - Pathname of the root filesystem on the NFS server
4186 serverip - see above
4189 There are two special Environment Variables:
4191 serial# - contains hardware identification information such
4192 as type string and/or serial number
4193 ethaddr - Ethernet address
4195 These variables can be set only once (usually during manufacturing of
4196 the board). U-Boot refuses to delete or overwrite these variables
4197 once they have been set once.
4200 Further special Environment Variables:
4202 ver - Contains the U-Boot version string as printed
4203 with the "version" command. This variable is
4204 readonly (see CONFIG_VERSION_VARIABLE).
4207 Please note that changes to some configuration parameters may take
4208 only effect after the next boot (yes, that's just like Windoze :-).
4211 Command Line Parsing:
4212 =====================
4214 There are two different command line parsers available with U-Boot:
4215 the old "simple" one, and the much more powerful "hush" shell:
4217 Old, simple command line parser:
4218 --------------------------------
4220 - supports environment variables (through setenv / saveenv commands)
4221 - several commands on one line, separated by ';'
4222 - variable substitution using "... ${name} ..." syntax
4223 - special characters ('$', ';') can be escaped by prefixing with '\',
4225 setenv bootcmd bootm \${address}
4226 - You can also escape text by enclosing in single apostrophes, for example:
4227 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4232 - similar to Bourne shell, with control structures like
4233 if...then...else...fi, for...do...done; while...do...done,
4234 until...do...done, ...
4235 - supports environment ("global") variables (through setenv / saveenv
4236 commands) and local shell variables (through standard shell syntax
4237 "name=value"); only environment variables can be used with "run"
4243 (1) If a command line (or an environment variable executed by a "run"
4244 command) contains several commands separated by semicolon, and
4245 one of these commands fails, then the remaining commands will be
4248 (2) If you execute several variables with one call to run (i. e.
4249 calling run with a list of variables as arguments), any failing
4250 command will cause "run" to terminate, i. e. the remaining
4251 variables are not executed.
4253 Note for Redundant Ethernet Interfaces:
4254 =======================================
4256 Some boards come with redundant Ethernet interfaces; U-Boot supports
4257 such configurations and is capable of automatic selection of a
4258 "working" interface when needed. MAC assignment works as follows:
4260 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4261 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4262 "eth1addr" (=>eth1), "eth2addr", ...
4264 If the network interface stores some valid MAC address (for instance
4265 in SROM), this is used as default address if there is NO correspon-
4266 ding setting in the environment; if the corresponding environment
4267 variable is set, this overrides the settings in the card; that means:
4269 o If the SROM has a valid MAC address, and there is no address in the
4270 environment, the SROM's address is used.
4272 o If there is no valid address in the SROM, and a definition in the
4273 environment exists, then the value from the environment variable is
4276 o If both the SROM and the environment contain a MAC address, and
4277 both addresses are the same, this MAC address is used.
4279 o If both the SROM and the environment contain a MAC address, and the
4280 addresses differ, the value from the environment is used and a
4283 o If neither SROM nor the environment contain a MAC address, an error
4286 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4287 will be programmed into hardware as part of the initialization process. This
4288 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4289 The naming convention is as follows:
4290 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4295 U-Boot is capable of booting (and performing other auxiliary operations on)
4296 images in two formats:
4298 New uImage format (FIT)
4299 -----------------------
4301 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4302 to Flattened Device Tree). It allows the use of images with multiple
4303 components (several kernels, ramdisks, etc.), with contents protected by
4304 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4310 Old image format is based on binary files which can be basically anything,
4311 preceded by a special header; see the definitions in include/image.h for
4312 details; basically, the header defines the following image properties:
4314 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4315 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4316 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4317 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4319 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4320 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4321 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4322 * Compression Type (uncompressed, gzip, bzip2)
4328 The header is marked by a special Magic Number, and both the header
4329 and the data portions of the image are secured against corruption by
4336 Although U-Boot should support any OS or standalone application
4337 easily, the main focus has always been on Linux during the design of
4340 U-Boot includes many features that so far have been part of some
4341 special "boot loader" code within the Linux kernel. Also, any
4342 "initrd" images to be used are no longer part of one big Linux image;
4343 instead, kernel and "initrd" are separate images. This implementation
4344 serves several purposes:
4346 - the same features can be used for other OS or standalone
4347 applications (for instance: using compressed images to reduce the
4348 Flash memory footprint)
4350 - it becomes much easier to port new Linux kernel versions because
4351 lots of low-level, hardware dependent stuff are done by U-Boot
4353 - the same Linux kernel image can now be used with different "initrd"
4354 images; of course this also means that different kernel images can
4355 be run with the same "initrd". This makes testing easier (you don't
4356 have to build a new "zImage.initrd" Linux image when you just
4357 change a file in your "initrd"). Also, a field-upgrade of the
4358 software is easier now.
4364 Porting Linux to U-Boot based systems:
4365 ---------------------------------------
4367 U-Boot cannot save you from doing all the necessary modifications to
4368 configure the Linux device drivers for use with your target hardware
4369 (no, we don't intend to provide a full virtual machine interface to
4372 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4374 Just make sure your machine specific header file (for instance
4375 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4376 Information structure as we define in include/asm-<arch>/u-boot.h,
4377 and make sure that your definition of IMAP_ADDR uses the same value
4378 as your U-Boot configuration in CONFIG_SYS_IMMR.
4381 Configuring the Linux kernel:
4382 -----------------------------
4384 No specific requirements for U-Boot. Make sure you have some root
4385 device (initial ramdisk, NFS) for your target system.
4388 Building a Linux Image:
4389 -----------------------
4391 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4392 not used. If you use recent kernel source, a new build target
4393 "uImage" will exist which automatically builds an image usable by
4394 U-Boot. Most older kernels also have support for a "pImage" target,
4395 which was introduced for our predecessor project PPCBoot and uses a
4396 100% compatible format.
4405 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4406 encapsulate a compressed Linux kernel image with header information,
4407 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4409 * build a standard "vmlinux" kernel image (in ELF binary format):
4411 * convert the kernel into a raw binary image:
4413 ${CROSS_COMPILE}-objcopy -O binary \
4414 -R .note -R .comment \
4415 -S vmlinux linux.bin
4417 * compress the binary image:
4421 * package compressed binary image for U-Boot:
4423 mkimage -A ppc -O linux -T kernel -C gzip \
4424 -a 0 -e 0 -n "Linux Kernel Image" \
4425 -d linux.bin.gz uImage
4428 The "mkimage" tool can also be used to create ramdisk images for use
4429 with U-Boot, either separated from the Linux kernel image, or
4430 combined into one file. "mkimage" encapsulates the images with a 64
4431 byte header containing information about target architecture,
4432 operating system, image type, compression method, entry points, time
4433 stamp, CRC32 checksums, etc.
4435 "mkimage" can be called in two ways: to verify existing images and
4436 print the header information, or to build new images.
4438 In the first form (with "-l" option) mkimage lists the information
4439 contained in the header of an existing U-Boot image; this includes
4440 checksum verification:
4442 tools/mkimage -l image
4443 -l ==> list image header information
4445 The second form (with "-d" option) is used to build a U-Boot image
4446 from a "data file" which is used as image payload:
4448 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4449 -n name -d data_file image
4450 -A ==> set architecture to 'arch'
4451 -O ==> set operating system to 'os'
4452 -T ==> set image type to 'type'
4453 -C ==> set compression type 'comp'
4454 -a ==> set load address to 'addr' (hex)
4455 -e ==> set entry point to 'ep' (hex)
4456 -n ==> set image name to 'name'
4457 -d ==> use image data from 'datafile'
4459 Right now, all Linux kernels for PowerPC systems use the same load
4460 address (0x00000000), but the entry point address depends on the
4463 - 2.2.x kernels have the entry point at 0x0000000C,
4464 - 2.3.x and later kernels have the entry point at 0x00000000.
4466 So a typical call to build a U-Boot image would read:
4468 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4469 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4470 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4471 > examples/uImage.TQM850L
4472 Image Name: 2.4.4 kernel for TQM850L
4473 Created: Wed Jul 19 02:34:59 2000
4474 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4475 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4476 Load Address: 0x00000000
4477 Entry Point: 0x00000000
4479 To verify the contents of the image (or check for corruption):
4481 -> tools/mkimage -l examples/uImage.TQM850L
4482 Image Name: 2.4.4 kernel for TQM850L
4483 Created: Wed Jul 19 02:34:59 2000
4484 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4485 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4486 Load Address: 0x00000000
4487 Entry Point: 0x00000000
4489 NOTE: for embedded systems where boot time is critical you can trade
4490 speed for memory and install an UNCOMPRESSED image instead: this
4491 needs more space in Flash, but boots much faster since it does not
4492 need to be uncompressed:
4494 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4495 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4496 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4497 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4498 > examples/uImage.TQM850L-uncompressed
4499 Image Name: 2.4.4 kernel for TQM850L
4500 Created: Wed Jul 19 02:34:59 2000
4501 Image Type: PowerPC Linux Kernel Image (uncompressed)
4502 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4503 Load Address: 0x00000000
4504 Entry Point: 0x00000000
4507 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4508 when your kernel is intended to use an initial ramdisk:
4510 -> tools/mkimage -n 'Simple Ramdisk Image' \
4511 > -A ppc -O linux -T ramdisk -C gzip \
4512 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4513 Image Name: Simple Ramdisk Image
4514 Created: Wed Jan 12 14:01:50 2000
4515 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4516 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4517 Load Address: 0x00000000
4518 Entry Point: 0x00000000
4521 Installing a Linux Image:
4522 -------------------------
4524 To downloading a U-Boot image over the serial (console) interface,
4525 you must convert the image to S-Record format:
4527 objcopy -I binary -O srec examples/image examples/image.srec
4529 The 'objcopy' does not understand the information in the U-Boot
4530 image header, so the resulting S-Record file will be relative to
4531 address 0x00000000. To load it to a given address, you need to
4532 specify the target address as 'offset' parameter with the 'loads'
4535 Example: install the image to address 0x40100000 (which on the
4536 TQM8xxL is in the first Flash bank):
4538 => erase 40100000 401FFFFF
4544 ## Ready for S-Record download ...
4545 ~>examples/image.srec
4546 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4548 15989 15990 15991 15992
4549 [file transfer complete]
4551 ## Start Addr = 0x00000000
4554 You can check the success of the download using the 'iminfo' command;
4555 this includes a checksum verification so you can be sure no data
4556 corruption happened:
4560 ## Checking Image at 40100000 ...
4561 Image Name: 2.2.13 for initrd on TQM850L
4562 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4563 Data Size: 335725 Bytes = 327 kB = 0 MB
4564 Load Address: 00000000
4565 Entry Point: 0000000c
4566 Verifying Checksum ... OK
4572 The "bootm" command is used to boot an application that is stored in
4573 memory (RAM or Flash). In case of a Linux kernel image, the contents
4574 of the "bootargs" environment variable is passed to the kernel as
4575 parameters. You can check and modify this variable using the
4576 "printenv" and "setenv" commands:
4579 => printenv bootargs
4580 bootargs=root=/dev/ram
4582 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4584 => printenv bootargs
4585 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4588 ## Booting Linux kernel at 40020000 ...
4589 Image Name: 2.2.13 for NFS on TQM850L
4590 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4591 Data Size: 381681 Bytes = 372 kB = 0 MB
4592 Load Address: 00000000
4593 Entry Point: 0000000c
4594 Verifying Checksum ... OK
4595 Uncompressing Kernel Image ... OK
4596 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
4597 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4598 time_init: decrementer frequency = 187500000/60
4599 Calibrating delay loop... 49.77 BogoMIPS
4600 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4603 If you want to boot a Linux kernel with initial RAM disk, you pass
4604 the memory addresses of both the kernel and the initrd image (PPBCOOT
4605 format!) to the "bootm" command:
4607 => imi 40100000 40200000
4609 ## Checking Image at 40100000 ...
4610 Image Name: 2.2.13 for initrd on TQM850L
4611 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4612 Data Size: 335725 Bytes = 327 kB = 0 MB
4613 Load Address: 00000000
4614 Entry Point: 0000000c
4615 Verifying Checksum ... OK
4617 ## Checking Image at 40200000 ...
4618 Image Name: Simple Ramdisk Image
4619 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4620 Data Size: 566530 Bytes = 553 kB = 0 MB
4621 Load Address: 00000000
4622 Entry Point: 00000000
4623 Verifying Checksum ... OK
4625 => bootm 40100000 40200000
4626 ## Booting Linux kernel at 40100000 ...
4627 Image Name: 2.2.13 for initrd on TQM850L
4628 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4629 Data Size: 335725 Bytes = 327 kB = 0 MB
4630 Load Address: 00000000
4631 Entry Point: 0000000c
4632 Verifying Checksum ... OK
4633 Uncompressing Kernel Image ... OK
4634 ## Loading RAMDisk Image at 40200000 ...
4635 Image Name: Simple Ramdisk Image
4636 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4637 Data Size: 566530 Bytes = 553 kB = 0 MB
4638 Load Address: 00000000
4639 Entry Point: 00000000
4640 Verifying Checksum ... OK
4641 Loading Ramdisk ... OK
4642 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
4643 Boot arguments: root=/dev/ram
4644 time_init: decrementer frequency = 187500000/60
4645 Calibrating delay loop... 49.77 BogoMIPS
4647 RAMDISK: Compressed image found at block 0
4648 VFS: Mounted root (ext2 filesystem).
4652 Boot Linux and pass a flat device tree:
4655 First, U-Boot must be compiled with the appropriate defines. See the section
4656 titled "Linux Kernel Interface" above for a more in depth explanation. The
4657 following is an example of how to start a kernel and pass an updated
4663 oft=oftrees/mpc8540ads.dtb
4664 => tftp $oftaddr $oft
4665 Speed: 1000, full duplex
4667 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4668 Filename 'oftrees/mpc8540ads.dtb'.
4669 Load address: 0x300000
4672 Bytes transferred = 4106 (100a hex)
4673 => tftp $loadaddr $bootfile
4674 Speed: 1000, full duplex
4676 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4678 Load address: 0x200000
4679 Loading:############
4681 Bytes transferred = 1029407 (fb51f hex)
4686 => bootm $loadaddr - $oftaddr
4687 ## Booting image at 00200000 ...
4688 Image Name: Linux-2.6.17-dirty
4689 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4690 Data Size: 1029343 Bytes = 1005.2 kB
4691 Load Address: 00000000
4692 Entry Point: 00000000
4693 Verifying Checksum ... OK
4694 Uncompressing Kernel Image ... OK
4695 Booting using flat device tree at 0x300000
4696 Using MPC85xx ADS machine description
4697 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4701 More About U-Boot Image Types:
4702 ------------------------------
4704 U-Boot supports the following image types:
4706 "Standalone Programs" are directly runnable in the environment
4707 provided by U-Boot; it is expected that (if they behave
4708 well) you can continue to work in U-Boot after return from
4709 the Standalone Program.
4710 "OS Kernel Images" are usually images of some Embedded OS which
4711 will take over control completely. Usually these programs
4712 will install their own set of exception handlers, device
4713 drivers, set up the MMU, etc. - this means, that you cannot
4714 expect to re-enter U-Boot except by resetting the CPU.
4715 "RAMDisk Images" are more or less just data blocks, and their
4716 parameters (address, size) are passed to an OS kernel that is
4718 "Multi-File Images" contain several images, typically an OS
4719 (Linux) kernel image and one or more data images like
4720 RAMDisks. This construct is useful for instance when you want
4721 to boot over the network using BOOTP etc., where the boot
4722 server provides just a single image file, but you want to get
4723 for instance an OS kernel and a RAMDisk image.
4725 "Multi-File Images" start with a list of image sizes, each
4726 image size (in bytes) specified by an "uint32_t" in network
4727 byte order. This list is terminated by an "(uint32_t)0".
4728 Immediately after the terminating 0 follow the images, one by
4729 one, all aligned on "uint32_t" boundaries (size rounded up to
4730 a multiple of 4 bytes).
4732 "Firmware Images" are binary images containing firmware (like
4733 U-Boot or FPGA images) which usually will be programmed to
4736 "Script files" are command sequences that will be executed by
4737 U-Boot's command interpreter; this feature is especially
4738 useful when you configure U-Boot to use a real shell (hush)
4739 as command interpreter.
4741 Booting the Linux zImage:
4742 -------------------------
4744 On some platforms, it's possible to boot Linux zImage. This is done
4745 using the "bootz" command. The syntax of "bootz" command is the same
4746 as the syntax of "bootm" command.
4748 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4749 kernel with raw initrd images. The syntax is slightly different, the
4750 address of the initrd must be augmented by it's size, in the following
4751 format: "<initrd addres>:<initrd size>".
4757 One of the features of U-Boot is that you can dynamically load and
4758 run "standalone" applications, which can use some resources of
4759 U-Boot like console I/O functions or interrupt services.
4761 Two simple examples are included with the sources:
4766 'examples/hello_world.c' contains a small "Hello World" Demo
4767 application; it is automatically compiled when you build U-Boot.
4768 It's configured to run at address 0x00040004, so you can play with it
4772 ## Ready for S-Record download ...
4773 ~>examples/hello_world.srec
4774 1 2 3 4 5 6 7 8 9 10 11 ...
4775 [file transfer complete]
4777 ## Start Addr = 0x00040004
4779 => go 40004 Hello World! This is a test.
4780 ## Starting application at 0x00040004 ...
4791 Hit any key to exit ...
4793 ## Application terminated, rc = 0x0
4795 Another example, which demonstrates how to register a CPM interrupt
4796 handler with the U-Boot code, can be found in 'examples/timer.c'.
4797 Here, a CPM timer is set up to generate an interrupt every second.
4798 The interrupt service routine is trivial, just printing a '.'
4799 character, but this is just a demo program. The application can be
4800 controlled by the following keys:
4802 ? - print current values og the CPM Timer registers
4803 b - enable interrupts and start timer
4804 e - stop timer and disable interrupts
4805 q - quit application
4808 ## Ready for S-Record download ...
4809 ~>examples/timer.srec
4810 1 2 3 4 5 6 7 8 9 10 11 ...
4811 [file transfer complete]
4813 ## Start Addr = 0x00040004
4816 ## Starting application at 0x00040004 ...
4819 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4822 [q, b, e, ?] Set interval 1000000 us
4825 [q, b, e, ?] ........
4826 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4829 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4832 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4835 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4837 [q, b, e, ?] ...Stopping timer
4839 [q, b, e, ?] ## Application terminated, rc = 0x0
4845 Over time, many people have reported problems when trying to use the
4846 "minicom" terminal emulation program for serial download. I (wd)
4847 consider minicom to be broken, and recommend not to use it. Under
4848 Unix, I recommend to use C-Kermit for general purpose use (and
4849 especially for kermit binary protocol download ("loadb" command), and
4850 use "cu" for S-Record download ("loads" command). See
4851 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4852 for help with kermit.
4855 Nevertheless, if you absolutely want to use it try adding this
4856 configuration to your "File transfer protocols" section:
4858 Name Program Name U/D FullScr IO-Red. Multi
4859 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4860 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4866 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4867 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4869 Building requires a cross environment; it is known to work on
4870 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4871 need gmake since the Makefiles are not compatible with BSD make).
4872 Note that the cross-powerpc package does not install include files;
4873 attempting to build U-Boot will fail because <machine/ansi.h> is
4874 missing. This file has to be installed and patched manually:
4876 # cd /usr/pkg/cross/powerpc-netbsd/include
4878 # ln -s powerpc machine
4879 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4880 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4882 Native builds *don't* work due to incompatibilities between native
4883 and U-Boot include files.
4885 Booting assumes that (the first part of) the image booted is a
4886 stage-2 loader which in turn loads and then invokes the kernel
4887 proper. Loader sources will eventually appear in the NetBSD source
4888 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4889 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4892 Implementation Internals:
4893 =========================
4895 The following is not intended to be a complete description of every
4896 implementation detail. However, it should help to understand the
4897 inner workings of U-Boot and make it easier to port it to custom
4901 Initial Stack, Global Data:
4902 ---------------------------
4904 The implementation of U-Boot is complicated by the fact that U-Boot
4905 starts running out of ROM (flash memory), usually without access to
4906 system RAM (because the memory controller is not initialized yet).
4907 This means that we don't have writable Data or BSS segments, and BSS
4908 is not initialized as zero. To be able to get a C environment working
4909 at all, we have to allocate at least a minimal stack. Implementation
4910 options for this are defined and restricted by the CPU used: Some CPU
4911 models provide on-chip memory (like the IMMR area on MPC8xx and
4912 MPC826x processors), on others (parts of) the data cache can be
4913 locked as (mis-) used as memory, etc.
4915 Chris Hallinan posted a good summary of these issues to the
4916 U-Boot mailing list:
4918 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4919 From: "Chris Hallinan" <clh@net1plus.com>
4920 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4923 Correct me if I'm wrong, folks, but the way I understand it
4924 is this: Using DCACHE as initial RAM for Stack, etc, does not
4925 require any physical RAM backing up the cache. The cleverness
4926 is that the cache is being used as a temporary supply of
4927 necessary storage before the SDRAM controller is setup. It's
4928 beyond the scope of this list to explain the details, but you
4929 can see how this works by studying the cache architecture and
4930 operation in the architecture and processor-specific manuals.
4932 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4933 is another option for the system designer to use as an
4934 initial stack/RAM area prior to SDRAM being available. Either
4935 option should work for you. Using CS 4 should be fine if your
4936 board designers haven't used it for something that would
4937 cause you grief during the initial boot! It is frequently not
4940 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4941 with your processor/board/system design. The default value
4942 you will find in any recent u-boot distribution in
4943 walnut.h should work for you. I'd set it to a value larger
4944 than your SDRAM module. If you have a 64MB SDRAM module, set
4945 it above 400_0000. Just make sure your board has no resources
4946 that are supposed to respond to that address! That code in
4947 start.S has been around a while and should work as is when
4948 you get the config right.
4953 It is essential to remember this, since it has some impact on the C
4954 code for the initialization procedures:
4956 * Initialized global data (data segment) is read-only. Do not attempt
4959 * Do not use any uninitialized global data (or implicitely initialized
4960 as zero data - BSS segment) at all - this is undefined, initiali-
4961 zation is performed later (when relocating to RAM).
4963 * Stack space is very limited. Avoid big data buffers or things like
4966 Having only the stack as writable memory limits means we cannot use
4967 normal global data to share information beween the code. But it
4968 turned out that the implementation of U-Boot can be greatly
4969 simplified by making a global data structure (gd_t) available to all
4970 functions. We could pass a pointer to this data as argument to _all_
4971 functions, but this would bloat the code. Instead we use a feature of
4972 the GCC compiler (Global Register Variables) to share the data: we
4973 place a pointer (gd) to the global data into a register which we
4974 reserve for this purpose.
4976 When choosing a register for such a purpose we are restricted by the
4977 relevant (E)ABI specifications for the current architecture, and by
4978 GCC's implementation.
4980 For PowerPC, the following registers have specific use:
4982 R2: reserved for system use
4983 R3-R4: parameter passing and return values
4984 R5-R10: parameter passing
4985 R13: small data area pointer
4989 (U-Boot also uses R12 as internal GOT pointer. r12
4990 is a volatile register so r12 needs to be reset when
4991 going back and forth between asm and C)
4993 ==> U-Boot will use R2 to hold a pointer to the global data
4995 Note: on PPC, we could use a static initializer (since the
4996 address of the global data structure is known at compile time),
4997 but it turned out that reserving a register results in somewhat
4998 smaller code - although the code savings are not that big (on
4999 average for all boards 752 bytes for the whole U-Boot image,
5000 624 text + 127 data).
5002 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5003 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5005 ==> U-Boot will use P3 to hold a pointer to the global data
5007 On ARM, the following registers are used:
5009 R0: function argument word/integer result
5010 R1-R3: function argument word
5012 R10: stack limit (used only if stack checking if enabled)
5013 R11: argument (frame) pointer
5014 R12: temporary workspace
5017 R15: program counter
5019 ==> U-Boot will use R8 to hold a pointer to the global data
5021 On Nios II, the ABI is documented here:
5022 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5024 ==> U-Boot will use gp to hold a pointer to the global data
5026 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5027 to access small data sections, so gp is free.
5029 On NDS32, the following registers are used:
5031 R0-R1: argument/return
5033 R15: temporary register for assembler
5034 R16: trampoline register
5035 R28: frame pointer (FP)
5036 R29: global pointer (GP)
5037 R30: link register (LP)
5038 R31: stack pointer (SP)
5039 PC: program counter (PC)
5041 ==> U-Boot will use R10 to hold a pointer to the global data
5043 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5044 or current versions of GCC may "optimize" the code too much.
5049 U-Boot runs in system state and uses physical addresses, i.e. the
5050 MMU is not used either for address mapping nor for memory protection.
5052 The available memory is mapped to fixed addresses using the memory
5053 controller. In this process, a contiguous block is formed for each
5054 memory type (Flash, SDRAM, SRAM), even when it consists of several
5055 physical memory banks.
5057 U-Boot is installed in the first 128 kB of the first Flash bank (on
5058 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5059 booting and sizing and initializing DRAM, the code relocates itself
5060 to the upper end of DRAM. Immediately below the U-Boot code some
5061 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5062 configuration setting]. Below that, a structure with global Board
5063 Info data is placed, followed by the stack (growing downward).
5065 Additionally, some exception handler code is copied to the low 8 kB
5066 of DRAM (0x00000000 ... 0x00001FFF).
5068 So a typical memory configuration with 16 MB of DRAM could look like
5071 0x0000 0000 Exception Vector code
5074 0x0000 2000 Free for Application Use
5080 0x00FB FF20 Monitor Stack (Growing downward)
5081 0x00FB FFAC Board Info Data and permanent copy of global data
5082 0x00FC 0000 Malloc Arena
5085 0x00FE 0000 RAM Copy of Monitor Code
5086 ... eventually: LCD or video framebuffer
5087 ... eventually: pRAM (Protected RAM - unchanged by reset)
5088 0x00FF FFFF [End of RAM]
5091 System Initialization:
5092 ----------------------
5094 In the reset configuration, U-Boot starts at the reset entry point
5095 (on most PowerPC systems at address 0x00000100). Because of the reset
5096 configuration for CS0# this is a mirror of the onboard Flash memory.
5097 To be able to re-map memory U-Boot then jumps to its link address.
5098 To be able to implement the initialization code in C, a (small!)
5099 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5100 which provide such a feature like MPC8xx or MPC8260), or in a locked
5101 part of the data cache. After that, U-Boot initializes the CPU core,
5102 the caches and the SIU.
5104 Next, all (potentially) available memory banks are mapped using a
5105 preliminary mapping. For example, we put them on 512 MB boundaries
5106 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5107 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5108 programmed for SDRAM access. Using the temporary configuration, a
5109 simple memory test is run that determines the size of the SDRAM
5112 When there is more than one SDRAM bank, and the banks are of
5113 different size, the largest is mapped first. For equal size, the first
5114 bank (CS2#) is mapped first. The first mapping is always for address
5115 0x00000000, with any additional banks following immediately to create
5116 contiguous memory starting from 0.
5118 Then, the monitor installs itself at the upper end of the SDRAM area
5119 and allocates memory for use by malloc() and for the global Board
5120 Info data; also, the exception vector code is copied to the low RAM
5121 pages, and the final stack is set up.
5123 Only after this relocation will you have a "normal" C environment;
5124 until that you are restricted in several ways, mostly because you are
5125 running from ROM, and because the code will have to be relocated to a
5129 U-Boot Porting Guide:
5130 ----------------------
5132 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5136 int main(int argc, char *argv[])
5138 sighandler_t no_more_time;
5140 signal(SIGALRM, no_more_time);
5141 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5143 if (available_money > available_manpower) {
5144 Pay consultant to port U-Boot;
5148 Download latest U-Boot source;
5150 Subscribe to u-boot mailing list;
5153 email("Hi, I am new to U-Boot, how do I get started?");
5156 Read the README file in the top level directory;
5157 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5158 Read applicable doc/*.README;
5159 Read the source, Luke;
5160 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5163 if (available_money > toLocalCurrency ($2500))
5166 Add a lot of aggravation and time;
5168 if (a similar board exists) { /* hopefully... */
5169 cp -a board/<similar> board/<myboard>
5170 cp include/configs/<similar>.h include/configs/<myboard>.h
5172 Create your own board support subdirectory;
5173 Create your own board include/configs/<myboard>.h file;
5175 Edit new board/<myboard> files
5176 Edit new include/configs/<myboard>.h
5181 Add / modify source code;
5185 email("Hi, I am having problems...");
5187 Send patch file to the U-Boot email list;
5188 if (reasonable critiques)
5189 Incorporate improvements from email list code review;
5191 Defend code as written;
5197 void no_more_time (int sig)
5206 All contributions to U-Boot should conform to the Linux kernel
5207 coding style; see the file "Documentation/CodingStyle" and the script
5208 "scripts/Lindent" in your Linux kernel source directory.
5210 Source files originating from a different project (for example the
5211 MTD subsystem) are generally exempt from these guidelines and are not
5212 reformated to ease subsequent migration to newer versions of those
5215 Please note that U-Boot is implemented in C (and to some small parts in
5216 Assembler); no C++ is used, so please do not use C++ style comments (//)
5219 Please also stick to the following formatting rules:
5220 - remove any trailing white space
5221 - use TAB characters for indentation and vertical alignment, not spaces
5222 - make sure NOT to use DOS '\r\n' line feeds
5223 - do not add more than 2 consecutive empty lines to source files
5224 - do not add trailing empty lines to source files
5226 Submissions which do not conform to the standards may be returned
5227 with a request to reformat the changes.
5233 Since the number of patches for U-Boot is growing, we need to
5234 establish some rules. Submissions which do not conform to these rules
5235 may be rejected, even when they contain important and valuable stuff.
5237 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5239 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5240 see http://lists.denx.de/mailman/listinfo/u-boot
5242 When you send a patch, please include the following information with
5245 * For bug fixes: a description of the bug and how your patch fixes
5246 this bug. Please try to include a way of demonstrating that the
5247 patch actually fixes something.
5249 * For new features: a description of the feature and your
5252 * A CHANGELOG entry as plaintext (separate from the patch)
5254 * For major contributions, your entry to the CREDITS file
5256 * When you add support for a new board, don't forget to add this
5257 board to the MAINTAINERS file, too.
5259 * If your patch adds new configuration options, don't forget to
5260 document these in the README file.
5262 * The patch itself. If you are using git (which is *strongly*
5263 recommended) you can easily generate the patch using the
5264 "git format-patch". If you then use "git send-email" to send it to
5265 the U-Boot mailing list, you will avoid most of the common problems
5266 with some other mail clients.
5268 If you cannot use git, use "diff -purN OLD NEW". If your version of
5269 diff does not support these options, then get the latest version of
5272 The current directory when running this command shall be the parent
5273 directory of the U-Boot source tree (i. e. please make sure that
5274 your patch includes sufficient directory information for the
5277 We prefer patches as plain text. MIME attachments are discouraged,
5278 and compressed attachments must not be used.
5280 * If one logical set of modifications affects or creates several
5281 files, all these changes shall be submitted in a SINGLE patch file.
5283 * Changesets that contain different, unrelated modifications shall be
5284 submitted as SEPARATE patches, one patch per changeset.
5289 * Before sending the patch, run the MAKEALL script on your patched
5290 source tree and make sure that no errors or warnings are reported
5291 for any of the boards.
5293 * Keep your modifications to the necessary minimum: A patch
5294 containing several unrelated changes or arbitrary reformats will be
5295 returned with a request to re-formatting / split it.
5297 * If you modify existing code, make sure that your new code does not
5298 add to the memory footprint of the code ;-) Small is beautiful!
5299 When adding new features, these should compile conditionally only
5300 (using #ifdef), and the resulting code with the new feature
5301 disabled must not need more memory than the old code without your
5304 * Remember that there is a size limit of 100 kB per message on the
5305 u-boot mailing list. Bigger patches will be moderated. If they are
5306 reasonable and not too big, they will be acknowledged. But patches
5307 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob