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
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /x86 Files generic to x86 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /mips32 Files specific to MIPS32 CPUs
184 /xburst Files specific to Ingenic XBurst CPUs
185 /lib Architecture specific library files
186 /nds32 Files generic to NDS32 architecture
187 /cpu CPU specific files
188 /n1213 Files specific to Andes Technology N1213 CPUs
189 /lib Architecture specific library files
190 /nios2 Files generic to Altera NIOS2 architecture
191 /cpu CPU specific files
192 /lib Architecture specific library files
193 /powerpc Files generic to PowerPC architecture
194 /cpu CPU specific files
195 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
196 /mpc5xx Files specific to Freescale MPC5xx CPUs
197 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
198 /mpc8xx Files specific to Freescale MPC8xx CPUs
199 /mpc8220 Files specific to Freescale MPC8220 CPUs
200 /mpc824x Files specific to Freescale MPC824x CPUs
201 /mpc8260 Files specific to Freescale MPC8260 CPUs
202 /mpc85xx Files specific to Freescale MPC85xx CPUs
203 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
204 /lib Architecture specific library files
205 /sh Files generic to SH architecture
206 /cpu CPU specific files
207 /sh2 Files specific to sh2 CPUs
208 /sh3 Files specific to sh3 CPUs
209 /sh4 Files specific to sh4 CPUs
210 /lib Architecture specific library files
211 /sparc Files generic to SPARC architecture
212 /cpu CPU specific files
213 /leon2 Files specific to Gaisler LEON2 SPARC CPU
214 /leon3 Files specific to Gaisler LEON3 SPARC CPU
215 /lib Architecture specific library files
216 /api Machine/arch independent API for external apps
217 /board Board dependent files
218 /common Misc architecture independent functions
219 /disk Code for disk drive partition handling
220 /doc Documentation (don't expect too much)
221 /drivers Commonly used device drivers
222 /examples Example code for standalone applications, etc.
223 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
224 /include Header Files
225 /lib Files generic to all architectures
226 /libfdt Library files to support flattened device trees
227 /lzma Library files to support LZMA decompression
228 /lzo Library files to support LZO decompression
230 /post Power On Self Test
231 /rtc Real Time Clock drivers
232 /tools Tools to build S-Record or U-Boot images, etc.
234 Software Configuration:
235 =======================
237 Configuration is usually done using C preprocessor defines; the
238 rationale behind that is to avoid dead code whenever possible.
240 There are two classes of configuration variables:
242 * Configuration _OPTIONS_:
243 These are selectable by the user and have names beginning with
246 * Configuration _SETTINGS_:
247 These depend on the hardware etc. and should not be meddled with if
248 you don't know what you're doing; they have names beginning with
251 Later we will add a configuration tool - probably similar to or even
252 identical to what's used for the Linux kernel. Right now, we have to
253 do the configuration by hand, which means creating some symbolic
254 links and editing some configuration files. We use the TQM8xxL boards
258 Selection of Processor Architecture and Board Type:
259 ---------------------------------------------------
261 For all supported boards there are ready-to-use default
262 configurations available; just type "make <board_name>_config".
264 Example: For a TQM823L module type:
269 For the Cogent platform, you need to specify the CPU type as well;
270 e.g. "make cogent_mpc8xx_config". And also configure the cogent
271 directory according to the instructions in cogent/README.
274 Configuration Options:
275 ----------------------
277 Configuration depends on the combination of board and CPU type; all
278 such information is kept in a configuration file
279 "include/configs/<board_name>.h".
281 Example: For a TQM823L module, all configuration settings are in
282 "include/configs/TQM823L.h".
285 Many of the options are named exactly as the corresponding Linux
286 kernel configuration options. The intention is to make it easier to
287 build a config tool - later.
290 The following options need to be configured:
292 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
294 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
296 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
297 Define exactly one, e.g. CONFIG_ATSTK1002
299 - CPU Module Type: (if CONFIG_COGENT is defined)
300 Define exactly one of
302 --- FIXME --- not tested yet:
303 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
304 CONFIG_CMA287_23, CONFIG_CMA287_50
306 - Motherboard Type: (if CONFIG_COGENT is defined)
307 Define exactly one of
308 CONFIG_CMA101, CONFIG_CMA102
310 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
311 Define one or more of
314 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
315 Define one or more of
316 CONFIG_LCD_HEARTBEAT - update a character position on
317 the LCD display every second with
320 - Board flavour: (if CONFIG_MPC8260ADS is defined)
323 CONFIG_SYS_8260ADS - original MPC8260ADS
324 CONFIG_SYS_8266ADS - MPC8266ADS
325 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
326 CONFIG_SYS_8272ADS - MPC8272ADS
328 - Marvell Family Member
329 CONFIG_SYS_MVFS - define it if you want to enable
330 multiple fs option at one time
331 for marvell soc family
333 - MPC824X Family Member (if CONFIG_MPC824X is defined)
334 Define exactly one of
335 CONFIG_MPC8240, CONFIG_MPC8245
337 - 8xx CPU Options: (if using an MPC8xx CPU)
338 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
339 get_gclk_freq() cannot work
340 e.g. if there is no 32KHz
341 reference PIT/RTC clock
342 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
345 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
346 CONFIG_SYS_8xx_CPUCLK_MIN
347 CONFIG_SYS_8xx_CPUCLK_MAX
348 CONFIG_8xx_CPUCLK_DEFAULT
349 See doc/README.MPC866
351 CONFIG_SYS_MEASURE_CPUCLK
353 Define this to measure the actual CPU clock instead
354 of relying on the correctness of the configured
355 values. Mostly useful for board bringup to make sure
356 the PLL is locked at the intended frequency. Note
357 that this requires a (stable) reference clock (32 kHz
358 RTC clock or CONFIG_SYS_8XX_XIN)
360 CONFIG_SYS_DELAYED_ICACHE
362 Define this option if you want to enable the
363 ICache only when Code runs from RAM.
366 CONFIG_SYS_FSL_TBCLK_DIV
368 Defines the core time base clock divider ratio compared to the
369 system clock. On most PQ3 devices this is 8, on newer QorIQ
370 devices it can be 16 or 32. The ratio varies from SoC to Soc.
372 CONFIG_SYS_FSL_PCIE_COMPAT
374 Defines the string to utilize when trying to match PCIe device
375 tree nodes for the given platform.
377 CONFIG_SYS_PPC_E500_DEBUG_TLB
379 Enables a temporary TLB entry to be used during boot to work
380 around limitations in e500v1 and e500v2 external debugger
381 support. This reduces the portions of the boot code where
382 breakpoints and single stepping do not work. The value of this
383 symbol should be set to the TLB1 entry to be used for this
386 CONFIG_SYS_FSL_ERRATUM_A004510
388 Enables a workaround for erratum A004510. If set,
389 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
390 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
392 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
393 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
395 Defines one or two SoC revisions (low 8 bits of SVR)
396 for which the A004510 workaround should be applied.
398 The rest of SVR is either not relevant to the decision
399 of whether the erratum is present (e.g. p2040 versus
400 p2041) or is implied by the build target, which controls
401 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
403 See Freescale App Note 4493 for more information about
406 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
408 This is the value to write into CCSR offset 0x18600
409 according to the A004510 workaround.
411 - Generic CPU options:
412 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
414 Defines the endianess of the CPU. Implementation of those
415 values is arch specific.
417 - Intel Monahans options:
418 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
420 Defines the Monahans run mode to oscillator
421 ratio. Valid values are 8, 16, 24, 31. The core
422 frequency is this value multiplied by 13 MHz.
424 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
426 Defines the Monahans turbo mode to oscillator
427 ratio. Valid values are 1 (default if undefined) and
428 2. The core frequency as calculated above is multiplied
432 CONFIG_SYS_INIT_SP_OFFSET
434 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
435 pointer. This is needed for the temporary stack before
438 CONFIG_SYS_MIPS_CACHE_MODE
440 Cache operation mode for the MIPS CPU.
441 See also arch/mips/include/asm/mipsregs.h.
443 CONF_CM_CACHABLE_NO_WA
446 CONF_CM_CACHABLE_NONCOHERENT
450 CONF_CM_CACHABLE_ACCELERATED
452 CONFIG_SYS_XWAY_EBU_BOOTCFG
454 Special option for Lantiq XWAY SoCs for booting from NOR flash.
455 See also arch/mips/cpu/mips32/start.S.
457 CONFIG_XWAY_SWAP_BYTES
459 Enable compilation of tools/xway-swap-bytes needed for Lantiq
460 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
461 be swapped if a flash programmer is used.
464 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
466 Select high exception vectors of the ARM core, e.g., do not
467 clear the V bit of the c1 register of CP15.
469 CONFIG_SYS_THUMB_BUILD
471 Use this flag to build U-Boot using the Thumb instruction
472 set for ARM architectures. Thumb instruction set provides
473 better code density. For ARM architectures that support
474 Thumb2 this flag will result in Thumb2 code generated by
477 - Linux Kernel Interface:
480 U-Boot stores all clock information in Hz
481 internally. For binary compatibility with older Linux
482 kernels (which expect the clocks passed in the
483 bd_info data to be in MHz) the environment variable
484 "clocks_in_mhz" can be defined so that U-Boot
485 converts clock data to MHZ before passing it to the
487 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
488 "clocks_in_mhz=1" is automatically included in the
491 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
493 When transferring memsize parameter to linux, some versions
494 expect it to be in bytes, others in MB.
495 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
499 New kernel versions are expecting firmware settings to be
500 passed using flattened device trees (based on open firmware
504 * New libfdt-based support
505 * Adds the "fdt" command
506 * The bootm command automatically updates the fdt
508 OF_CPU - The proper name of the cpus node (only required for
509 MPC512X and MPC5xxx based boards).
510 OF_SOC - The proper name of the soc node (only required for
511 MPC512X and MPC5xxx based boards).
512 OF_TBCLK - The timebase frequency.
513 OF_STDOUT_PATH - The path to the console device
515 boards with QUICC Engines require OF_QE to set UCC MAC
518 CONFIG_OF_BOARD_SETUP
520 Board code has addition modification that it wants to make
521 to the flat device tree before handing it off to the kernel
525 This define fills in the correct boot CPU in the boot
526 param header, the default value is zero if undefined.
530 U-Boot can detect if an IDE device is present or not.
531 If not, and this new config option is activated, U-Boot
532 removes the ATA node from the DTS before booting Linux,
533 so the Linux IDE driver does not probe the device and
534 crash. This is needed for buggy hardware (uc101) where
535 no pull down resistor is connected to the signal IDE5V_DD7.
537 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
539 This setting is mandatory for all boards that have only one
540 machine type and must be used to specify the machine type
541 number as it appears in the ARM machine registry
542 (see http://www.arm.linux.org.uk/developer/machines/).
543 Only boards that have multiple machine types supported
544 in a single configuration file and the machine type is
545 runtime discoverable, do not have to use this setting.
547 - vxWorks boot parameters:
549 bootvx constructs a valid bootline using the following
550 environments variables: bootfile, ipaddr, serverip, hostname.
551 It loads the vxWorks image pointed bootfile.
553 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
554 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
555 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
556 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
558 CONFIG_SYS_VXWORKS_ADD_PARAMS
560 Add it at the end of the bootline. E.g "u=username pw=secret"
562 Note: If a "bootargs" environment is defined, it will overwride
563 the defaults discussed just above.
565 - Cache Configuration:
566 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
567 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
568 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
570 - Cache Configuration for ARM:
571 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
573 CONFIG_SYS_PL310_BASE - Physical base address of PL310
574 controller register space
579 Define this if you want support for Amba PrimeCell PL010 UARTs.
583 Define this if you want support for Amba PrimeCell PL011 UARTs.
587 If you have Amba PrimeCell PL011 UARTs, set this variable to
588 the clock speed of the UARTs.
592 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
593 define this to a list of base addresses for each (supported)
594 port. See e.g. include/configs/versatile.h
596 CONFIG_PL011_SERIAL_RLCR
598 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
599 have separate receive and transmit line control registers. Set
600 this variable to initialize the extra register.
602 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
604 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
605 boot loader that has already initialized the UART. Define this
606 variable to flush the UART at init time.
610 Depending on board, define exactly one serial port
611 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
612 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
613 console by defining CONFIG_8xx_CONS_NONE
615 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
616 port routines must be defined elsewhere
617 (i.e. serial_init(), serial_getc(), ...)
620 Enables console device for a color framebuffer. Needs following
621 defines (cf. smiLynxEM, i8042)
622 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
624 VIDEO_HW_RECTFILL graphic chip supports
627 VIDEO_HW_BITBLT graphic chip supports
628 bit-blit (cf. smiLynxEM)
629 VIDEO_VISIBLE_COLS visible pixel columns
631 VIDEO_VISIBLE_ROWS visible pixel rows
632 VIDEO_PIXEL_SIZE bytes per pixel
633 VIDEO_DATA_FORMAT graphic data format
634 (0-5, cf. cfb_console.c)
635 VIDEO_FB_ADRS framebuffer address
636 VIDEO_KBD_INIT_FCT keyboard int fct
637 (i.e. i8042_kbd_init())
638 VIDEO_TSTC_FCT test char fct
640 VIDEO_GETC_FCT get char fct
642 CONFIG_CONSOLE_CURSOR cursor drawing on/off
643 (requires blink timer
645 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
646 CONFIG_CONSOLE_TIME display time/date info in
648 (requires CONFIG_CMD_DATE)
649 CONFIG_VIDEO_LOGO display Linux logo in
651 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
652 linux_logo.h for logo.
653 Requires CONFIG_VIDEO_LOGO
654 CONFIG_CONSOLE_EXTRA_INFO
655 additional board info beside
658 When CONFIG_CFB_CONSOLE is defined, video console is
659 default i/o. Serial console can be forced with
660 environment 'console=serial'.
662 When CONFIG_SILENT_CONSOLE is defined, all console
663 messages (by U-Boot and Linux!) can be silenced with
664 the "silent" environment variable. See
665 doc/README.silent for more information.
668 CONFIG_BAUDRATE - in bps
669 Select one of the baudrates listed in
670 CONFIG_SYS_BAUDRATE_TABLE, see below.
671 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
673 - Console Rx buffer length
674 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
675 the maximum receive buffer length for the SMC.
676 This option is actual only for 82xx and 8xx possible.
677 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
678 must be defined, to setup the maximum idle timeout for
681 - Pre-Console Buffer:
682 Prior to the console being initialised (i.e. serial UART
683 initialised etc) all console output is silently discarded.
684 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
685 buffer any console messages prior to the console being
686 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
687 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
688 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
689 bytes are output before the console is initialised, the
690 earlier bytes are discarded.
692 'Sane' compilers will generate smaller code if
693 CONFIG_PRE_CON_BUF_SZ is a power of 2
695 - Safe printf() functions
696 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
697 the printf() functions. These are defined in
698 include/vsprintf.h and include snprintf(), vsnprintf() and
699 so on. Code size increase is approximately 300-500 bytes.
700 If this option is not given then these functions will
701 silently discard their buffer size argument - this means
702 you are not getting any overflow checking in this case.
704 - Boot Delay: CONFIG_BOOTDELAY - in seconds
705 Delay before automatically booting the default image;
706 set to -1 to disable autoboot.
707 set to -2 to autoboot with no delay and not check for abort
708 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
710 See doc/README.autoboot for these options that
711 work with CONFIG_BOOTDELAY. None are required.
712 CONFIG_BOOT_RETRY_TIME
713 CONFIG_BOOT_RETRY_MIN
714 CONFIG_AUTOBOOT_KEYED
715 CONFIG_AUTOBOOT_PROMPT
716 CONFIG_AUTOBOOT_DELAY_STR
717 CONFIG_AUTOBOOT_STOP_STR
718 CONFIG_AUTOBOOT_DELAY_STR2
719 CONFIG_AUTOBOOT_STOP_STR2
720 CONFIG_ZERO_BOOTDELAY_CHECK
721 CONFIG_RESET_TO_RETRY
725 Only needed when CONFIG_BOOTDELAY is enabled;
726 define a command string that is automatically executed
727 when no character is read on the console interface
728 within "Boot Delay" after reset.
731 This can be used to pass arguments to the bootm
732 command. The value of CONFIG_BOOTARGS goes into the
733 environment value "bootargs".
735 CONFIG_RAMBOOT and CONFIG_NFSBOOT
736 The value of these goes into the environment as
737 "ramboot" and "nfsboot" respectively, and can be used
738 as a convenience, when switching between booting from
744 When this option is #defined, the existence of the
745 environment variable "preboot" will be checked
746 immediately before starting the CONFIG_BOOTDELAY
747 countdown and/or running the auto-boot command resp.
748 entering interactive mode.
750 This feature is especially useful when "preboot" is
751 automatically generated or modified. For an example
752 see the LWMON board specific code: here "preboot" is
753 modified when the user holds down a certain
754 combination of keys on the (special) keyboard when
757 - Serial Download Echo Mode:
759 If defined to 1, all characters received during a
760 serial download (using the "loads" command) are
761 echoed back. This might be needed by some terminal
762 emulations (like "cu"), but may as well just take
763 time on others. This setting #define's the initial
764 value of the "loads_echo" environment variable.
766 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
768 Select one of the baudrates listed in
769 CONFIG_SYS_BAUDRATE_TABLE, see below.
772 Monitor commands can be included or excluded
773 from the build by using the #include files
774 <config_cmd_all.h> and #undef'ing unwanted
775 commands, or using <config_cmd_default.h>
776 and augmenting with additional #define's
779 The default command configuration includes all commands
780 except those marked below with a "*".
782 CONFIG_CMD_ASKENV * ask for env variable
783 CONFIG_CMD_BDI bdinfo
784 CONFIG_CMD_BEDBUG * Include BedBug Debugger
785 CONFIG_CMD_BMP * BMP support
786 CONFIG_CMD_BSP * Board specific commands
787 CONFIG_CMD_BOOTD bootd
788 CONFIG_CMD_CACHE * icache, dcache
789 CONFIG_CMD_CONSOLE coninfo
790 CONFIG_CMD_CRC32 * crc32
791 CONFIG_CMD_DATE * support for RTC, date/time...
792 CONFIG_CMD_DHCP * DHCP support
793 CONFIG_CMD_DIAG * Diagnostics
794 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
795 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
796 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
797 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
798 CONFIG_CMD_DTT * Digital Therm and Thermostat
799 CONFIG_CMD_ECHO echo arguments
800 CONFIG_CMD_EDITENV edit env variable
801 CONFIG_CMD_EEPROM * EEPROM read/write support
802 CONFIG_CMD_ELF * bootelf, bootvx
803 CONFIG_CMD_EXPORTENV * export the environment
804 CONFIG_CMD_SAVEENV saveenv
805 CONFIG_CMD_FDC * Floppy Disk Support
806 CONFIG_CMD_FAT * FAT partition support
807 CONFIG_CMD_FDOS * Dos diskette Support
808 CONFIG_CMD_FLASH flinfo, erase, protect
809 CONFIG_CMD_FPGA FPGA device initialization support
810 CONFIG_CMD_GO * the 'go' command (exec code)
811 CONFIG_CMD_GREPENV * search environment
812 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
813 CONFIG_CMD_I2C * I2C serial bus support
814 CONFIG_CMD_IDE * IDE harddisk support
815 CONFIG_CMD_IMI iminfo
816 CONFIG_CMD_IMLS List all found images
817 CONFIG_CMD_IMMAP * IMMR dump support
818 CONFIG_CMD_IMPORTENV * import an environment
819 CONFIG_CMD_IRQ * irqinfo
820 CONFIG_CMD_ITEST Integer/string test of 2 values
821 CONFIG_CMD_JFFS2 * JFFS2 Support
822 CONFIG_CMD_KGDB * kgdb
823 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
824 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
826 CONFIG_CMD_LOADB loadb
827 CONFIG_CMD_LOADS loads
828 CONFIG_CMD_MD5SUM print md5 message digest
829 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
830 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
832 CONFIG_CMD_MISC Misc functions like sleep etc
833 CONFIG_CMD_MMC * MMC memory mapped support
834 CONFIG_CMD_MII * MII utility commands
835 CONFIG_CMD_MTDPARTS * MTD partition support
836 CONFIG_CMD_NAND * NAND support
837 CONFIG_CMD_NET bootp, tftpboot, rarpboot
838 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
839 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
840 CONFIG_CMD_PCI * pciinfo
841 CONFIG_CMD_PCMCIA * PCMCIA support
842 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
844 CONFIG_CMD_PORTIO * Port I/O
845 CONFIG_CMD_REGINFO * Register dump
846 CONFIG_CMD_RUN run command in env variable
847 CONFIG_CMD_SAVES * save S record dump
848 CONFIG_CMD_SCSI * SCSI Support
849 CONFIG_CMD_SDRAM * print SDRAM configuration information
850 (requires CONFIG_CMD_I2C)
851 CONFIG_CMD_SETGETDCR Support for DCR Register access
853 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
854 CONFIG_CMD_SHA1SUM print sha1 memory digest
855 (requires CONFIG_CMD_MEMORY)
856 CONFIG_CMD_SOURCE "source" command Support
857 CONFIG_CMD_SPI * SPI serial bus support
858 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
859 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
860 CONFIG_CMD_TIME * run command and report execution time
861 CONFIG_CMD_USB * USB support
862 CONFIG_CMD_CDP * Cisco Discover Protocol support
863 CONFIG_CMD_MFSL * Microblaze FSL support
866 EXAMPLE: If you want all functions except of network
867 support you can write:
869 #include "config_cmd_all.h"
870 #undef CONFIG_CMD_NET
873 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
875 Note: Don't enable the "icache" and "dcache" commands
876 (configuration option CONFIG_CMD_CACHE) unless you know
877 what you (and your U-Boot users) are doing. Data
878 cache cannot be enabled on systems like the 8xx or
879 8260 (where accesses to the IMMR region must be
880 uncached), and it cannot be disabled on all other
881 systems where we (mis-) use the data cache to hold an
882 initial stack and some data.
885 XXX - this list needs to get updated!
889 If this variable is defined, U-Boot will use a device tree
890 to configure its devices, instead of relying on statically
891 compiled #defines in the board file. This option is
892 experimental and only available on a few boards. The device
893 tree is available in the global data as gd->fdt_blob.
895 U-Boot needs to get its device tree from somewhere. This can
896 be done using one of the two options below:
899 If this variable is defined, U-Boot will embed a device tree
900 binary in its image. This device tree file should be in the
901 board directory and called <soc>-<board>.dts. The binary file
902 is then picked up in board_init_f() and made available through
903 the global data structure as gd->blob.
906 If this variable is defined, U-Boot will build a device tree
907 binary. It will be called u-boot.dtb. Architecture-specific
908 code will locate it at run-time. Generally this works by:
910 cat u-boot.bin u-boot.dtb >image.bin
912 and in fact, U-Boot does this for you, creating a file called
913 u-boot-dtb.bin which is useful in the common case. You can
914 still use the individual files if you need something more
919 If this variable is defined, it enables watchdog
920 support for the SoC. There must be support in the SoC
921 specific code for a watchdog. For the 8xx and 8260
922 CPUs, the SIU Watchdog feature is enabled in the SYPCR
923 register. When supported for a specific SoC is
924 available, then no further board specific code should
928 When using a watchdog circuitry external to the used
929 SoC, then define this variable and provide board
930 specific code for the "hw_watchdog_reset" function.
933 CONFIG_VERSION_VARIABLE
934 If this variable is defined, an environment variable
935 named "ver" is created by U-Boot showing the U-Boot
936 version as printed by the "version" command.
937 Any change to this variable will be reverted at the
942 When CONFIG_CMD_DATE is selected, the type of the RTC
943 has to be selected, too. Define exactly one of the
946 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
947 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
948 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
949 CONFIG_RTC_MC146818 - use MC146818 RTC
950 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
951 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
952 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
953 CONFIG_RTC_DS164x - use Dallas DS164x RTC
954 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
955 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
956 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
957 CONFIG_SYS_RV3029_TCR - enable trickle charger on
960 Note that if the RTC uses I2C, then the I2C interface
961 must also be configured. See I2C Support, below.
964 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
965 CONFIG_PCA953X_INFO - enable pca953x info command
967 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
968 chip-ngpio pairs that tell the PCA953X driver the number of
969 pins supported by a particular chip.
971 Note that if the GPIO device uses I2C, then the I2C interface
972 must also be configured. See I2C Support, below.
976 When CONFIG_TIMESTAMP is selected, the timestamp
977 (date and time) of an image is printed by image
978 commands like bootm or iminfo. This option is
979 automatically enabled when you select CONFIG_CMD_DATE .
981 - Partition Labels (disklabels) Supported:
982 Zero or more of the following:
983 CONFIG_MAC_PARTITION Apple's MacOS partition table.
984 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
985 Intel architecture, USB sticks, etc.
986 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
987 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
988 bootloader. Note 2TB partition limit; see
990 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
992 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
993 CONFIG_CMD_SCSI) you must configure support for at
994 least one non-MTD partition type as well.
997 CONFIG_IDE_RESET_ROUTINE - this is defined in several
998 board configurations files but used nowhere!
1000 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1001 be performed by calling the function
1002 ide_set_reset(int reset)
1003 which has to be defined in a board specific file
1008 Set this to enable ATAPI support.
1013 Set this to enable support for disks larger than 137GB
1014 Also look at CONFIG_SYS_64BIT_LBA.
1015 Whithout these , LBA48 support uses 32bit variables and will 'only'
1016 support disks up to 2.1TB.
1018 CONFIG_SYS_64BIT_LBA:
1019 When enabled, makes the IDE subsystem use 64bit sector addresses.
1023 At the moment only there is only support for the
1024 SYM53C8XX SCSI controller; define
1025 CONFIG_SCSI_SYM53C8XX to enable it.
1027 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1028 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1029 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1030 maximum numbers of LUNs, SCSI ID's and target
1032 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1034 - NETWORK Support (PCI):
1036 Support for Intel 8254x/8257x gigabit chips.
1039 Utility code for direct access to the SPI bus on Intel 8257x.
1040 This does not do anything useful unless you set at least one
1041 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1043 CONFIG_E1000_SPI_GENERIC
1044 Allow generic access to the SPI bus on the Intel 8257x, for
1045 example with the "sspi" command.
1048 Management command for E1000 devices. When used on devices
1049 with SPI support you can reprogram the EEPROM from U-Boot.
1051 CONFIG_E1000_FALLBACK_MAC
1052 default MAC for empty EEPROM after production.
1055 Support for Intel 82557/82559/82559ER chips.
1056 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1057 write routine for first time initialisation.
1060 Support for Digital 2114x chips.
1061 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1062 modem chip initialisation (KS8761/QS6611).
1065 Support for National dp83815 chips.
1068 Support for National dp8382[01] gigabit chips.
1070 - NETWORK Support (other):
1072 CONFIG_DRIVER_AT91EMAC
1073 Support for AT91RM9200 EMAC.
1076 Define this to use reduced MII inteface
1078 CONFIG_DRIVER_AT91EMAC_QUIET
1079 If this defined, the driver is quiet.
1080 The driver doen't show link status messages.
1082 CONFIG_CALXEDA_XGMAC
1083 Support for the Calxeda XGMAC device
1085 CONFIG_DRIVER_LAN91C96
1086 Support for SMSC's LAN91C96 chips.
1088 CONFIG_LAN91C96_BASE
1089 Define this to hold the physical address
1090 of the LAN91C96's I/O space
1092 CONFIG_LAN91C96_USE_32_BIT
1093 Define this to enable 32 bit addressing
1095 CONFIG_DRIVER_SMC91111
1096 Support for SMSC's LAN91C111 chip
1098 CONFIG_SMC91111_BASE
1099 Define this to hold the physical address
1100 of the device (I/O space)
1102 CONFIG_SMC_USE_32_BIT
1103 Define this if data bus is 32 bits
1105 CONFIG_SMC_USE_IOFUNCS
1106 Define this to use i/o functions instead of macros
1107 (some hardware wont work with macros)
1109 CONFIG_DRIVER_TI_EMAC
1110 Support for davinci emac
1112 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1113 Define this if you have more then 3 PHYs.
1116 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1118 CONFIG_FTGMAC100_EGIGA
1119 Define this to use GE link update with gigabit PHY.
1120 Define this if FTGMAC100 is connected to gigabit PHY.
1121 If your system has 10/100 PHY only, it might not occur
1122 wrong behavior. Because PHY usually return timeout or
1123 useless data when polling gigabit status and gigabit
1124 control registers. This behavior won't affect the
1125 correctnessof 10/100 link speed update.
1128 Support for SMSC's LAN911x and LAN921x chips
1131 Define this to hold the physical address
1132 of the device (I/O space)
1134 CONFIG_SMC911X_32_BIT
1135 Define this if data bus is 32 bits
1137 CONFIG_SMC911X_16_BIT
1138 Define this if data bus is 16 bits. If your processor
1139 automatically converts one 32 bit word to two 16 bit
1140 words you may also try CONFIG_SMC911X_32_BIT.
1143 Support for Renesas on-chip Ethernet controller
1145 CONFIG_SH_ETHER_USE_PORT
1146 Define the number of ports to be used
1148 CONFIG_SH_ETHER_PHY_ADDR
1149 Define the ETH PHY's address
1151 CONFIG_SH_ETHER_CACHE_WRITEBACK
1152 If this option is set, the driver enables cache flush.
1155 CONFIG_GENERIC_LPC_TPM
1156 Support for generic parallel port TPM devices. Only one device
1157 per system is supported at this time.
1159 CONFIG_TPM_TIS_BASE_ADDRESS
1160 Base address where the generic TPM device is mapped
1161 to. Contemporary x86 systems usually map it at
1165 At the moment only the UHCI host controller is
1166 supported (PIP405, MIP405, MPC5200); define
1167 CONFIG_USB_UHCI to enable it.
1168 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1169 and define CONFIG_USB_STORAGE to enable the USB
1172 Supported are USB Keyboards and USB Floppy drives
1174 MPC5200 USB requires additional defines:
1176 for 528 MHz Clock: 0x0001bbbb
1180 for differential drivers: 0x00001000
1181 for single ended drivers: 0x00005000
1182 for differential drivers on PSC3: 0x00000100
1183 for single ended drivers on PSC3: 0x00004100
1184 CONFIG_SYS_USB_EVENT_POLL
1185 May be defined to allow interrupt polling
1186 instead of using asynchronous interrupts
1188 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1189 txfilltuning field in the EHCI controller on reset.
1192 Define the below if you wish to use the USB console.
1193 Once firmware is rebuilt from a serial console issue the
1194 command "setenv stdin usbtty; setenv stdout usbtty" and
1195 attach your USB cable. The Unix command "dmesg" should print
1196 it has found a new device. The environment variable usbtty
1197 can be set to gserial or cdc_acm to enable your device to
1198 appear to a USB host as a Linux gserial device or a
1199 Common Device Class Abstract Control Model serial device.
1200 If you select usbtty = gserial you should be able to enumerate
1202 # modprobe usbserial vendor=0xVendorID product=0xProductID
1203 else if using cdc_acm, simply setting the environment
1204 variable usbtty to be cdc_acm should suffice. The following
1205 might be defined in YourBoardName.h
1208 Define this to build a UDC device
1211 Define this to have a tty type of device available to
1212 talk to the UDC device
1215 Define this to enable the high speed support for usb
1216 device and usbtty. If this feature is enabled, a routine
1217 int is_usbd_high_speed(void)
1218 also needs to be defined by the driver to dynamically poll
1219 whether the enumeration has succeded at high speed or full
1222 CONFIG_SYS_CONSOLE_IS_IN_ENV
1223 Define this if you want stdin, stdout &/or stderr to
1227 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1228 Derive USB clock from external clock "blah"
1229 - CONFIG_SYS_USB_EXTC_CLK 0x02
1231 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1232 Derive USB clock from brgclk
1233 - CONFIG_SYS_USB_BRG_CLK 0x04
1235 If you have a USB-IF assigned VendorID then you may wish to
1236 define your own vendor specific values either in BoardName.h
1237 or directly in usbd_vendor_info.h. If you don't define
1238 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1239 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1240 should pretend to be a Linux device to it's target host.
1242 CONFIG_USBD_MANUFACTURER
1243 Define this string as the name of your company for
1244 - CONFIG_USBD_MANUFACTURER "my company"
1246 CONFIG_USBD_PRODUCT_NAME
1247 Define this string as the name of your product
1248 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1250 CONFIG_USBD_VENDORID
1251 Define this as your assigned Vendor ID from the USB
1252 Implementors Forum. This *must* be a genuine Vendor ID
1253 to avoid polluting the USB namespace.
1254 - CONFIG_USBD_VENDORID 0xFFFF
1256 CONFIG_USBD_PRODUCTID
1257 Define this as the unique Product ID
1259 - CONFIG_USBD_PRODUCTID 0xFFFF
1261 - ULPI Layer Support:
1262 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1263 the generic ULPI layer. The generic layer accesses the ULPI PHY
1264 via the platform viewport, so you need both the genric layer and
1265 the viewport enabled. Currently only Chipidea/ARC based
1266 viewport is supported.
1267 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1268 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1271 The MMC controller on the Intel PXA is supported. To
1272 enable this define CONFIG_MMC. The MMC can be
1273 accessed from the boot prompt by mapping the device
1274 to physical memory similar to flash. Command line is
1275 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1276 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1279 Support for Renesas on-chip MMCIF controller
1281 CONFIG_SH_MMCIF_ADDR
1282 Define the base address of MMCIF registers
1285 Define the clock frequency for MMCIF
1287 - Journaling Flash filesystem support:
1288 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1289 CONFIG_JFFS2_NAND_DEV
1290 Define these for a default partition on a NAND device
1292 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1293 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1294 Define these for a default partition on a NOR device
1296 CONFIG_SYS_JFFS_CUSTOM_PART
1297 Define this to create an own partition. You have to provide a
1298 function struct part_info* jffs2_part_info(int part_num)
1300 If you define only one JFFS2 partition you may also want to
1301 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1302 to disable the command chpart. This is the default when you
1303 have not defined a custom partition
1305 - FAT(File Allocation Table) filesystem write function support:
1308 Define this to enable support for saving memory data as a
1309 file in FAT formatted partition.
1311 This will also enable the command "fatwrite" enabling the
1312 user to write files to FAT.
1317 Define this to enable standard (PC-Style) keyboard
1321 Standard PC keyboard driver with US (is default) and
1322 GERMAN key layout (switch via environment 'keymap=de') support.
1323 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1324 for cfb_console. Supports cursor blinking.
1329 Define this to enable video support (for output to
1332 CONFIG_VIDEO_CT69000
1334 Enable Chips & Technologies 69000 Video chip
1336 CONFIG_VIDEO_SMI_LYNXEM
1337 Enable Silicon Motion SMI 712/710/810 Video chip. The
1338 video output is selected via environment 'videoout'
1339 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1342 For the CT69000 and SMI_LYNXEM drivers, videomode is
1343 selected via environment 'videomode'. Two different ways
1345 - "videomode=num" 'num' is a standard LiLo mode numbers.
1346 Following standard modes are supported (* is default):
1348 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1349 -------------+---------------------------------------------
1350 8 bits | 0x301* 0x303 0x305 0x161 0x307
1351 15 bits | 0x310 0x313 0x316 0x162 0x319
1352 16 bits | 0x311 0x314 0x317 0x163 0x31A
1353 24 bits | 0x312 0x315 0x318 ? 0x31B
1354 -------------+---------------------------------------------
1355 (i.e. setenv videomode 317; saveenv; reset;)
1357 - "videomode=bootargs" all the video parameters are parsed
1358 from the bootargs. (See drivers/video/videomodes.c)
1361 CONFIG_VIDEO_SED13806
1362 Enable Epson SED13806 driver. This driver supports 8bpp
1363 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1364 or CONFIG_VIDEO_SED13806_16BPP
1367 Enable the Freescale DIU video driver. Reference boards for
1368 SOCs that have a DIU should define this macro to enable DIU
1369 support, and should also define these other macros:
1375 CONFIG_VIDEO_SW_CURSOR
1376 CONFIG_VGA_AS_SINGLE_DEVICE
1378 CONFIG_VIDEO_BMP_LOGO
1380 The DIU driver will look for the 'video-mode' environment
1381 variable, and if defined, enable the DIU as a console during
1382 boot. See the documentation file README.video for a
1383 description of this variable.
1388 Define this to enable a custom keyboard support.
1389 This simply calls drv_keyboard_init() which must be
1390 defined in your board-specific files.
1391 The only board using this so far is RBC823.
1393 - LCD Support: CONFIG_LCD
1395 Define this to enable LCD support (for output to LCD
1396 display); also select one of the supported displays
1397 by defining one of these:
1401 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1403 CONFIG_NEC_NL6448AC33:
1405 NEC NL6448AC33-18. Active, color, single scan.
1407 CONFIG_NEC_NL6448BC20
1409 NEC NL6448BC20-08. 6.5", 640x480.
1410 Active, color, single scan.
1412 CONFIG_NEC_NL6448BC33_54
1414 NEC NL6448BC33-54. 10.4", 640x480.
1415 Active, color, single scan.
1419 Sharp 320x240. Active, color, single scan.
1420 It isn't 16x9, and I am not sure what it is.
1422 CONFIG_SHARP_LQ64D341
1424 Sharp LQ64D341 display, 640x480.
1425 Active, color, single scan.
1429 HLD1045 display, 640x480.
1430 Active, color, single scan.
1434 Optrex CBL50840-2 NF-FW 99 22 M5
1436 Hitachi LMG6912RPFC-00T
1440 320x240. Black & white.
1442 Normally display is black on white background; define
1443 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1445 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1447 If this option is set, the environment is checked for
1448 a variable "splashimage". If found, the usual display
1449 of logo, copyright and system information on the LCD
1450 is suppressed and the BMP image at the address
1451 specified in "splashimage" is loaded instead. The
1452 console is redirected to the "nulldev", too. This
1453 allows for a "silent" boot where a splash screen is
1454 loaded very quickly after power-on.
1456 CONFIG_SPLASH_SCREEN_ALIGN
1458 If this option is set the splash image can be freely positioned
1459 on the screen. Environment variable "splashpos" specifies the
1460 position as "x,y". If a positive number is given it is used as
1461 number of pixel from left/top. If a negative number is given it
1462 is used as number of pixel from right/bottom. You can also
1463 specify 'm' for centering the image.
1466 setenv splashpos m,m
1467 => image at center of screen
1469 setenv splashpos 30,20
1470 => image at x = 30 and y = 20
1472 setenv splashpos -10,m
1473 => vertically centered image
1474 at x = dspWidth - bmpWidth - 9
1476 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1478 If this option is set, additionally to standard BMP
1479 images, gzipped BMP images can be displayed via the
1480 splashscreen support or the bmp command.
1482 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1484 If this option is set, 8-bit RLE compressed BMP images
1485 can be displayed via the splashscreen support or the
1488 - Do compresssing for memory range:
1491 If this option is set, it would use zlib deflate method
1492 to compress the specified memory at its best effort.
1494 - Compression support:
1497 If this option is set, support for bzip2 compressed
1498 images is included. If not, only uncompressed and gzip
1499 compressed images are supported.
1501 NOTE: the bzip2 algorithm requires a lot of RAM, so
1502 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1507 If this option is set, support for lzma compressed
1510 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1511 requires an amount of dynamic memory that is given by the
1514 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1516 Where lc and lp stand for, respectively, Literal context bits
1517 and Literal pos bits.
1519 This value is upper-bounded by 14MB in the worst case. Anyway,
1520 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1521 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1522 a very small buffer.
1524 Use the lzmainfo tool to determinate the lc and lp values and
1525 then calculate the amount of needed dynamic memory (ensuring
1526 the appropriate CONFIG_SYS_MALLOC_LEN value).
1531 The address of PHY on MII bus.
1533 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1535 The clock frequency of the MII bus
1539 If this option is set, support for speed/duplex
1540 detection of gigabit PHY is included.
1542 CONFIG_PHY_RESET_DELAY
1544 Some PHY like Intel LXT971A need extra delay after
1545 reset before any MII register access is possible.
1546 For such PHY, set this option to the usec delay
1547 required. (minimum 300usec for LXT971A)
1549 CONFIG_PHY_CMD_DELAY (ppc4xx)
1551 Some PHY like Intel LXT971A need extra delay after
1552 command issued before MII status register can be read
1562 Define a default value for Ethernet address to use
1563 for the respective Ethernet interface, in case this
1564 is not determined automatically.
1569 Define a default value for the IP address to use for
1570 the default Ethernet interface, in case this is not
1571 determined through e.g. bootp.
1572 (Environment variable "ipaddr")
1574 - Server IP address:
1577 Defines a default value for the IP address of a TFTP
1578 server to contact when using the "tftboot" command.
1579 (Environment variable "serverip")
1581 CONFIG_KEEP_SERVERADDR
1583 Keeps the server's MAC address, in the env 'serveraddr'
1584 for passing to bootargs (like Linux's netconsole option)
1586 - Gateway IP address:
1589 Defines a default value for the IP address of the
1590 default router where packets to other networks are
1592 (Environment variable "gatewayip")
1597 Defines a default value for the subnet mask (or
1598 routing prefix) which is used to determine if an IP
1599 address belongs to the local subnet or needs to be
1600 forwarded through a router.
1601 (Environment variable "netmask")
1603 - Multicast TFTP Mode:
1606 Defines whether you want to support multicast TFTP as per
1607 rfc-2090; for example to work with atftp. Lets lots of targets
1608 tftp down the same boot image concurrently. Note: the Ethernet
1609 driver in use must provide a function: mcast() to join/leave a
1612 - BOOTP Recovery Mode:
1613 CONFIG_BOOTP_RANDOM_DELAY
1615 If you have many targets in a network that try to
1616 boot using BOOTP, you may want to avoid that all
1617 systems send out BOOTP requests at precisely the same
1618 moment (which would happen for instance at recovery
1619 from a power failure, when all systems will try to
1620 boot, thus flooding the BOOTP server. Defining
1621 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1622 inserted before sending out BOOTP requests. The
1623 following delays are inserted then:
1625 1st BOOTP request: delay 0 ... 1 sec
1626 2nd BOOTP request: delay 0 ... 2 sec
1627 3rd BOOTP request: delay 0 ... 4 sec
1629 BOOTP requests: delay 0 ... 8 sec
1631 - DHCP Advanced Options:
1632 You can fine tune the DHCP functionality by defining
1633 CONFIG_BOOTP_* symbols:
1635 CONFIG_BOOTP_SUBNETMASK
1636 CONFIG_BOOTP_GATEWAY
1637 CONFIG_BOOTP_HOSTNAME
1638 CONFIG_BOOTP_NISDOMAIN
1639 CONFIG_BOOTP_BOOTPATH
1640 CONFIG_BOOTP_BOOTFILESIZE
1643 CONFIG_BOOTP_SEND_HOSTNAME
1644 CONFIG_BOOTP_NTPSERVER
1645 CONFIG_BOOTP_TIMEOFFSET
1646 CONFIG_BOOTP_VENDOREX
1647 CONFIG_BOOTP_MAY_FAIL
1649 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1650 environment variable, not the BOOTP server.
1652 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1653 after the configured retry count, the call will fail
1654 instead of starting over. This can be used to fail over
1655 to Link-local IP address configuration if the DHCP server
1658 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1659 serverip from a DHCP server, it is possible that more
1660 than one DNS serverip is offered to the client.
1661 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1662 serverip will be stored in the additional environment
1663 variable "dnsip2". The first DNS serverip is always
1664 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1667 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1668 to do a dynamic update of a DNS server. To do this, they
1669 need the hostname of the DHCP requester.
1670 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1671 of the "hostname" environment variable is passed as
1672 option 12 to the DHCP server.
1674 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1676 A 32bit value in microseconds for a delay between
1677 receiving a "DHCP Offer" and sending the "DHCP Request".
1678 This fixes a problem with certain DHCP servers that don't
1679 respond 100% of the time to a "DHCP request". E.g. On an
1680 AT91RM9200 processor running at 180MHz, this delay needed
1681 to be *at least* 15,000 usec before a Windows Server 2003
1682 DHCP server would reply 100% of the time. I recommend at
1683 least 50,000 usec to be safe. The alternative is to hope
1684 that one of the retries will be successful but note that
1685 the DHCP timeout and retry process takes a longer than
1688 - Link-local IP address negotiation:
1689 Negotiate with other link-local clients on the local network
1690 for an address that doesn't require explicit configuration.
1691 This is especially useful if a DHCP server cannot be guaranteed
1692 to exist in all environments that the device must operate.
1694 See doc/README.link-local for more information.
1697 CONFIG_CDP_DEVICE_ID
1699 The device id used in CDP trigger frames.
1701 CONFIG_CDP_DEVICE_ID_PREFIX
1703 A two character string which is prefixed to the MAC address
1708 A printf format string which contains the ascii name of
1709 the port. Normally is set to "eth%d" which sets
1710 eth0 for the first Ethernet, eth1 for the second etc.
1712 CONFIG_CDP_CAPABILITIES
1714 A 32bit integer which indicates the device capabilities;
1715 0x00000010 for a normal host which does not forwards.
1719 An ascii string containing the version of the software.
1723 An ascii string containing the name of the platform.
1727 A 32bit integer sent on the trigger.
1729 CONFIG_CDP_POWER_CONSUMPTION
1731 A 16bit integer containing the power consumption of the
1732 device in .1 of milliwatts.
1734 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1736 A byte containing the id of the VLAN.
1738 - Status LED: CONFIG_STATUS_LED
1740 Several configurations allow to display the current
1741 status using a LED. For instance, the LED will blink
1742 fast while running U-Boot code, stop blinking as
1743 soon as a reply to a BOOTP request was received, and
1744 start blinking slow once the Linux kernel is running
1745 (supported by a status LED driver in the Linux
1746 kernel). Defining CONFIG_STATUS_LED enables this
1749 - CAN Support: CONFIG_CAN_DRIVER
1751 Defining CONFIG_CAN_DRIVER enables CAN driver support
1752 on those systems that support this (optional)
1753 feature, like the TQM8xxL modules.
1755 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1757 These enable I2C serial bus commands. Defining either of
1758 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1759 include the appropriate I2C driver for the selected CPU.
1761 This will allow you to use i2c commands at the u-boot
1762 command line (as long as you set CONFIG_CMD_I2C in
1763 CONFIG_COMMANDS) and communicate with i2c based realtime
1764 clock chips. See common/cmd_i2c.c for a description of the
1765 command line interface.
1767 CONFIG_HARD_I2C selects a hardware I2C controller.
1769 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1770 bit-banging) driver instead of CPM or similar hardware
1773 There are several other quantities that must also be
1774 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1776 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1777 to be the frequency (in Hz) at which you wish your i2c bus
1778 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1779 the CPU's i2c node address).
1781 Now, the u-boot i2c code for the mpc8xx
1782 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1783 and so its address should therefore be cleared to 0 (See,
1784 eg, MPC823e User's Manual p.16-473). So, set
1785 CONFIG_SYS_I2C_SLAVE to 0.
1787 CONFIG_SYS_I2C_INIT_MPC5XXX
1789 When a board is reset during an i2c bus transfer
1790 chips might think that the current transfer is still
1791 in progress. Reset the slave devices by sending start
1792 commands until the slave device responds.
1794 That's all that's required for CONFIG_HARD_I2C.
1796 If you use the software i2c interface (CONFIG_SOFT_I2C)
1797 then the following macros need to be defined (examples are
1798 from include/configs/lwmon.h):
1802 (Optional). Any commands necessary to enable the I2C
1803 controller or configure ports.
1805 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1809 (Only for MPC8260 CPU). The I/O port to use (the code
1810 assumes both bits are on the same port). Valid values
1811 are 0..3 for ports A..D.
1815 The code necessary to make the I2C data line active
1816 (driven). If the data line is open collector, this
1819 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1823 The code necessary to make the I2C data line tri-stated
1824 (inactive). If the data line is open collector, this
1827 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1831 Code that returns TRUE if the I2C data line is high,
1834 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1838 If <bit> is TRUE, sets the I2C data line high. If it
1839 is FALSE, it clears it (low).
1841 eg: #define I2C_SDA(bit) \
1842 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1843 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1847 If <bit> is TRUE, sets the I2C clock line high. If it
1848 is FALSE, it clears it (low).
1850 eg: #define I2C_SCL(bit) \
1851 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1852 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1856 This delay is invoked four times per clock cycle so this
1857 controls the rate of data transfer. The data rate thus
1858 is 1 / (I2C_DELAY * 4). Often defined to be something
1861 #define I2C_DELAY udelay(2)
1863 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1865 If your arch supports the generic GPIO framework (asm/gpio.h),
1866 then you may alternatively define the two GPIOs that are to be
1867 used as SCL / SDA. Any of the previous I2C_xxx macros will
1868 have GPIO-based defaults assigned to them as appropriate.
1870 You should define these to the GPIO value as given directly to
1871 the generic GPIO functions.
1873 CONFIG_SYS_I2C_INIT_BOARD
1875 When a board is reset during an i2c bus transfer
1876 chips might think that the current transfer is still
1877 in progress. On some boards it is possible to access
1878 the i2c SCLK line directly, either by using the
1879 processor pin as a GPIO or by having a second pin
1880 connected to the bus. If this option is defined a
1881 custom i2c_init_board() routine in boards/xxx/board.c
1882 is run early in the boot sequence.
1884 CONFIG_SYS_I2C_BOARD_LATE_INIT
1886 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1887 defined a custom i2c_board_late_init() routine in
1888 boards/xxx/board.c is run AFTER the operations in i2c_init()
1889 is completed. This callpoint can be used to unreset i2c bus
1890 using CPU i2c controller register accesses for CPUs whose i2c
1891 controller provide such a method. It is called at the end of
1892 i2c_init() to allow i2c_init operations to setup the i2c bus
1893 controller on the CPU (e.g. setting bus speed & slave address).
1895 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1897 This option enables configuration of bi_iic_fast[] flags
1898 in u-boot bd_info structure based on u-boot environment
1899 variable "i2cfast". (see also i2cfast)
1901 CONFIG_I2C_MULTI_BUS
1903 This option allows the use of multiple I2C buses, each of which
1904 must have a controller. At any point in time, only one bus is
1905 active. To switch to a different bus, use the 'i2c dev' command.
1906 Note that bus numbering is zero-based.
1908 CONFIG_SYS_I2C_NOPROBES
1910 This option specifies a list of I2C devices that will be skipped
1911 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1912 is set, specify a list of bus-device pairs. Otherwise, specify
1913 a 1D array of device addresses
1916 #undef CONFIG_I2C_MULTI_BUS
1917 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1919 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1921 #define CONFIG_I2C_MULTI_BUS
1922 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1924 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1926 CONFIG_SYS_SPD_BUS_NUM
1928 If defined, then this indicates the I2C bus number for DDR SPD.
1929 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1931 CONFIG_SYS_RTC_BUS_NUM
1933 If defined, then this indicates the I2C bus number for the RTC.
1934 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1936 CONFIG_SYS_DTT_BUS_NUM
1938 If defined, then this indicates the I2C bus number for the DTT.
1939 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1941 CONFIG_SYS_I2C_DTT_ADDR:
1943 If defined, specifies the I2C address of the DTT device.
1944 If not defined, then U-Boot uses predefined value for
1945 specified DTT device.
1949 Define this option if you want to use Freescale's I2C driver in
1950 drivers/i2c/fsl_i2c.c.
1954 Define this option if you have I2C devices reached over 1 .. n
1955 I2C Muxes like the pca9544a. This option addes a new I2C
1956 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1957 new I2C Bus to the existing I2C Busses. If you select the
1958 new Bus with "i2c dev", u-bbot sends first the commandos for
1959 the muxes to activate this new "bus".
1961 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1965 Adding a new I2C Bus reached over 2 pca9544a muxes
1966 The First mux with address 70 and channel 6
1967 The Second mux with address 71 and channel 4
1969 => i2c bus pca9544a:70:6:pca9544a:71:4
1971 Use the "i2c bus" command without parameter, to get a list
1972 of I2C Busses with muxes:
1975 Busses reached over muxes:
1977 reached over Mux(es):
1980 reached over Mux(es):
1985 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1986 u-boot first sends the command to the mux@70 to enable
1987 channel 6, and then the command to the mux@71 to enable
1990 After that, you can use the "normal" i2c commands as
1991 usual to communicate with your I2C devices behind
1994 This option is actually implemented for the bitbanging
1995 algorithm in common/soft_i2c.c and for the Hardware I2C
1996 Bus on the MPC8260. But it should be not so difficult
1997 to add this option to other architectures.
1999 CONFIG_SOFT_I2C_READ_REPEATED_START
2001 defining this will force the i2c_read() function in
2002 the soft_i2c driver to perform an I2C repeated start
2003 between writing the address pointer and reading the
2004 data. If this define is omitted the default behaviour
2005 of doing a stop-start sequence will be used. Most I2C
2006 devices can use either method, but some require one or
2009 - SPI Support: CONFIG_SPI
2011 Enables SPI driver (so far only tested with
2012 SPI EEPROM, also an instance works with Crystal A/D and
2013 D/As on the SACSng board)
2017 Enables the driver for SPI controller on SuperH. Currently
2018 only SH7757 is supported.
2022 Enables extended (16-bit) SPI EEPROM addressing.
2023 (symmetrical to CONFIG_I2C_X)
2027 Enables a software (bit-bang) SPI driver rather than
2028 using hardware support. This is a general purpose
2029 driver that only requires three general I/O port pins
2030 (two outputs, one input) to function. If this is
2031 defined, the board configuration must define several
2032 SPI configuration items (port pins to use, etc). For
2033 an example, see include/configs/sacsng.h.
2037 Enables a hardware SPI driver for general-purpose reads
2038 and writes. As with CONFIG_SOFT_SPI, the board configuration
2039 must define a list of chip-select function pointers.
2040 Currently supported on some MPC8xxx processors. For an
2041 example, see include/configs/mpc8349emds.h.
2045 Enables the driver for the SPI controllers on i.MX and MXC
2046 SoCs. Currently i.MX31/35/51 are supported.
2048 - FPGA Support: CONFIG_FPGA
2050 Enables FPGA subsystem.
2052 CONFIG_FPGA_<vendor>
2054 Enables support for specific chip vendors.
2057 CONFIG_FPGA_<family>
2059 Enables support for FPGA family.
2060 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2064 Specify the number of FPGA devices to support.
2066 CONFIG_SYS_FPGA_PROG_FEEDBACK
2068 Enable printing of hash marks during FPGA configuration.
2070 CONFIG_SYS_FPGA_CHECK_BUSY
2072 Enable checks on FPGA configuration interface busy
2073 status by the configuration function. This option
2074 will require a board or device specific function to
2079 If defined, a function that provides delays in the FPGA
2080 configuration driver.
2082 CONFIG_SYS_FPGA_CHECK_CTRLC
2083 Allow Control-C to interrupt FPGA configuration
2085 CONFIG_SYS_FPGA_CHECK_ERROR
2087 Check for configuration errors during FPGA bitfile
2088 loading. For example, abort during Virtex II
2089 configuration if the INIT_B line goes low (which
2090 indicated a CRC error).
2092 CONFIG_SYS_FPGA_WAIT_INIT
2094 Maximum time to wait for the INIT_B line to deassert
2095 after PROB_B has been deasserted during a Virtex II
2096 FPGA configuration sequence. The default time is 500
2099 CONFIG_SYS_FPGA_WAIT_BUSY
2101 Maximum time to wait for BUSY to deassert during
2102 Virtex II FPGA configuration. The default is 5 ms.
2104 CONFIG_SYS_FPGA_WAIT_CONFIG
2106 Time to wait after FPGA configuration. The default is
2109 - Configuration Management:
2112 If defined, this string will be added to the U-Boot
2113 version information (U_BOOT_VERSION)
2115 - Vendor Parameter Protection:
2117 U-Boot considers the values of the environment
2118 variables "serial#" (Board Serial Number) and
2119 "ethaddr" (Ethernet Address) to be parameters that
2120 are set once by the board vendor / manufacturer, and
2121 protects these variables from casual modification by
2122 the user. Once set, these variables are read-only,
2123 and write or delete attempts are rejected. You can
2124 change this behaviour:
2126 If CONFIG_ENV_OVERWRITE is #defined in your config
2127 file, the write protection for vendor parameters is
2128 completely disabled. Anybody can change or delete
2131 Alternatively, if you #define _both_ CONFIG_ETHADDR
2132 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2133 Ethernet address is installed in the environment,
2134 which can be changed exactly ONCE by the user. [The
2135 serial# is unaffected by this, i. e. it remains
2141 Define this variable to enable the reservation of
2142 "protected RAM", i. e. RAM which is not overwritten
2143 by U-Boot. Define CONFIG_PRAM to hold the number of
2144 kB you want to reserve for pRAM. You can overwrite
2145 this default value by defining an environment
2146 variable "pram" to the number of kB you want to
2147 reserve. Note that the board info structure will
2148 still show the full amount of RAM. If pRAM is
2149 reserved, a new environment variable "mem" will
2150 automatically be defined to hold the amount of
2151 remaining RAM in a form that can be passed as boot
2152 argument to Linux, for instance like that:
2154 setenv bootargs ... mem=\${mem}
2157 This way you can tell Linux not to use this memory,
2158 either, which results in a memory region that will
2159 not be affected by reboots.
2161 *WARNING* If your board configuration uses automatic
2162 detection of the RAM size, you must make sure that
2163 this memory test is non-destructive. So far, the
2164 following board configurations are known to be
2167 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
2168 HERMES, IP860, RPXlite, LWMON, LANTEC,
2174 Define this variable to stop the system in case of a
2175 fatal error, so that you have to reset it manually.
2176 This is probably NOT a good idea for an embedded
2177 system where you want the system to reboot
2178 automatically as fast as possible, but it may be
2179 useful during development since you can try to debug
2180 the conditions that lead to the situation.
2182 CONFIG_NET_RETRY_COUNT
2184 This variable defines the number of retries for
2185 network operations like ARP, RARP, TFTP, or BOOTP
2186 before giving up the operation. If not defined, a
2187 default value of 5 is used.
2191 Timeout waiting for an ARP reply in milliseconds.
2195 Timeout in milliseconds used in NFS protocol.
2196 If you encounter "ERROR: Cannot umount" in nfs command,
2197 try longer timeout such as
2198 #define CONFIG_NFS_TIMEOUT 10000UL
2200 - Command Interpreter:
2201 CONFIG_AUTO_COMPLETE
2203 Enable auto completion of commands using TAB.
2205 Note that this feature has NOT been implemented yet
2206 for the "hush" shell.
2209 CONFIG_SYS_HUSH_PARSER
2211 Define this variable to enable the "hush" shell (from
2212 Busybox) as command line interpreter, thus enabling
2213 powerful command line syntax like
2214 if...then...else...fi conditionals or `&&' and '||'
2215 constructs ("shell scripts").
2217 If undefined, you get the old, much simpler behaviour
2218 with a somewhat smaller memory footprint.
2221 CONFIG_SYS_PROMPT_HUSH_PS2
2223 This defines the secondary prompt string, which is
2224 printed when the command interpreter needs more input
2225 to complete a command. Usually "> ".
2229 In the current implementation, the local variables
2230 space and global environment variables space are
2231 separated. Local variables are those you define by
2232 simply typing `name=value'. To access a local
2233 variable later on, you have write `$name' or
2234 `${name}'; to execute the contents of a variable
2235 directly type `$name' at the command prompt.
2237 Global environment variables are those you use
2238 setenv/printenv to work with. To run a command stored
2239 in such a variable, you need to use the run command,
2240 and you must not use the '$' sign to access them.
2242 To store commands and special characters in a
2243 variable, please use double quotation marks
2244 surrounding the whole text of the variable, instead
2245 of the backslashes before semicolons and special
2248 - Commandline Editing and History:
2249 CONFIG_CMDLINE_EDITING
2251 Enable editing and History functions for interactive
2252 commandline input operations
2254 - Default Environment:
2255 CONFIG_EXTRA_ENV_SETTINGS
2257 Define this to contain any number of null terminated
2258 strings (variable = value pairs) that will be part of
2259 the default environment compiled into the boot image.
2261 For example, place something like this in your
2262 board's config file:
2264 #define CONFIG_EXTRA_ENV_SETTINGS \
2268 Warning: This method is based on knowledge about the
2269 internal format how the environment is stored by the
2270 U-Boot code. This is NOT an official, exported
2271 interface! Although it is unlikely that this format
2272 will change soon, there is no guarantee either.
2273 You better know what you are doing here.
2275 Note: overly (ab)use of the default environment is
2276 discouraged. Make sure to check other ways to preset
2277 the environment like the "source" command or the
2280 CONFIG_ENV_VARS_UBOOT_CONFIG
2282 Define this in order to add variables describing the
2283 U-Boot build configuration to the default environment.
2284 These will be named arch, cpu, board, vendor, and soc.
2286 Enabling this option will cause the following to be defined:
2294 - DataFlash Support:
2295 CONFIG_HAS_DATAFLASH
2297 Defining this option enables DataFlash features and
2298 allows to read/write in Dataflash via the standard
2301 - Serial Flash support
2304 Defining this option enables SPI flash commands
2305 'sf probe/read/write/erase/update'.
2307 Usage requires an initial 'probe' to define the serial
2308 flash parameters, followed by read/write/erase/update
2311 The following defaults may be provided by the platform
2312 to handle the common case when only a single serial
2313 flash is present on the system.
2315 CONFIG_SF_DEFAULT_BUS Bus identifier
2316 CONFIG_SF_DEFAULT_CS Chip-select
2317 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2318 CONFIG_SF_DEFAULT_SPEED in Hz
2320 - SystemACE Support:
2323 Adding this option adds support for Xilinx SystemACE
2324 chips attached via some sort of local bus. The address
2325 of the chip must also be defined in the
2326 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2328 #define CONFIG_SYSTEMACE
2329 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2331 When SystemACE support is added, the "ace" device type
2332 becomes available to the fat commands, i.e. fatls.
2334 - TFTP Fixed UDP Port:
2337 If this is defined, the environment variable tftpsrcp
2338 is used to supply the TFTP UDP source port value.
2339 If tftpsrcp isn't defined, the normal pseudo-random port
2340 number generator is used.
2342 Also, the environment variable tftpdstp is used to supply
2343 the TFTP UDP destination port value. If tftpdstp isn't
2344 defined, the normal port 69 is used.
2346 The purpose for tftpsrcp is to allow a TFTP server to
2347 blindly start the TFTP transfer using the pre-configured
2348 target IP address and UDP port. This has the effect of
2349 "punching through" the (Windows XP) firewall, allowing
2350 the remainder of the TFTP transfer to proceed normally.
2351 A better solution is to properly configure the firewall,
2352 but sometimes that is not allowed.
2354 - Show boot progress:
2355 CONFIG_SHOW_BOOT_PROGRESS
2357 Defining this option allows to add some board-
2358 specific code (calling a user-provided function
2359 "show_boot_progress(int)") that enables you to show
2360 the system's boot progress on some display (for
2361 example, some LED's) on your board. At the moment,
2362 the following checkpoints are implemented:
2364 - Detailed boot stage timing
2366 Define this option to get detailed timing of each stage
2367 of the boot process.
2369 CONFIG_BOOTSTAGE_USER_COUNT
2370 This is the number of available user bootstage records.
2371 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2372 a new ID will be allocated from this stash. If you exceed
2373 the limit, recording will stop.
2375 CONFIG_BOOTSTAGE_REPORT
2376 Define this to print a report before boot, similar to this:
2378 Timer summary in microseconds:
2381 3,575,678 3,575,678 board_init_f start
2382 3,575,695 17 arch_cpu_init A9
2383 3,575,777 82 arch_cpu_init done
2384 3,659,598 83,821 board_init_r start
2385 3,910,375 250,777 main_loop
2386 29,916,167 26,005,792 bootm_start
2387 30,361,327 445,160 start_kernel
2389 Legacy uImage format:
2392 1 common/cmd_bootm.c before attempting to boot an image
2393 -1 common/cmd_bootm.c Image header has bad magic number
2394 2 common/cmd_bootm.c Image header has correct magic number
2395 -2 common/cmd_bootm.c Image header has bad checksum
2396 3 common/cmd_bootm.c Image header has correct checksum
2397 -3 common/cmd_bootm.c Image data has bad checksum
2398 4 common/cmd_bootm.c Image data has correct checksum
2399 -4 common/cmd_bootm.c Image is for unsupported architecture
2400 5 common/cmd_bootm.c Architecture check OK
2401 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2402 6 common/cmd_bootm.c Image Type check OK
2403 -6 common/cmd_bootm.c gunzip uncompression error
2404 -7 common/cmd_bootm.c Unimplemented compression type
2405 7 common/cmd_bootm.c Uncompression OK
2406 8 common/cmd_bootm.c No uncompress/copy overwrite error
2407 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2409 9 common/image.c Start initial ramdisk verification
2410 -10 common/image.c Ramdisk header has bad magic number
2411 -11 common/image.c Ramdisk header has bad checksum
2412 10 common/image.c Ramdisk header is OK
2413 -12 common/image.c Ramdisk data has bad checksum
2414 11 common/image.c Ramdisk data has correct checksum
2415 12 common/image.c Ramdisk verification complete, start loading
2416 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2417 13 common/image.c Start multifile image verification
2418 14 common/image.c No initial ramdisk, no multifile, continue.
2420 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2422 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2423 -31 post/post.c POST test failed, detected by post_output_backlog()
2424 -32 post/post.c POST test failed, detected by post_run_single()
2426 34 common/cmd_doc.c before loading a Image from a DOC device
2427 -35 common/cmd_doc.c Bad usage of "doc" command
2428 35 common/cmd_doc.c correct usage of "doc" command
2429 -36 common/cmd_doc.c No boot device
2430 36 common/cmd_doc.c correct boot device
2431 -37 common/cmd_doc.c Unknown Chip ID on boot device
2432 37 common/cmd_doc.c correct chip ID found, device available
2433 -38 common/cmd_doc.c Read Error on boot device
2434 38 common/cmd_doc.c reading Image header from DOC device OK
2435 -39 common/cmd_doc.c Image header has bad magic number
2436 39 common/cmd_doc.c Image header has correct magic number
2437 -40 common/cmd_doc.c Error reading Image from DOC device
2438 40 common/cmd_doc.c Image header has correct magic number
2439 41 common/cmd_ide.c before loading a Image from a IDE device
2440 -42 common/cmd_ide.c Bad usage of "ide" command
2441 42 common/cmd_ide.c correct usage of "ide" command
2442 -43 common/cmd_ide.c No boot device
2443 43 common/cmd_ide.c boot device found
2444 -44 common/cmd_ide.c Device not available
2445 44 common/cmd_ide.c Device available
2446 -45 common/cmd_ide.c wrong partition selected
2447 45 common/cmd_ide.c partition selected
2448 -46 common/cmd_ide.c Unknown partition table
2449 46 common/cmd_ide.c valid partition table found
2450 -47 common/cmd_ide.c Invalid partition type
2451 47 common/cmd_ide.c correct partition type
2452 -48 common/cmd_ide.c Error reading Image Header on boot device
2453 48 common/cmd_ide.c reading Image Header from IDE device OK
2454 -49 common/cmd_ide.c Image header has bad magic number
2455 49 common/cmd_ide.c Image header has correct magic number
2456 -50 common/cmd_ide.c Image header has bad checksum
2457 50 common/cmd_ide.c Image header has correct checksum
2458 -51 common/cmd_ide.c Error reading Image from IDE device
2459 51 common/cmd_ide.c reading Image from IDE device OK
2460 52 common/cmd_nand.c before loading a Image from a NAND device
2461 -53 common/cmd_nand.c Bad usage of "nand" command
2462 53 common/cmd_nand.c correct usage of "nand" command
2463 -54 common/cmd_nand.c No boot device
2464 54 common/cmd_nand.c boot device found
2465 -55 common/cmd_nand.c Unknown Chip ID on boot device
2466 55 common/cmd_nand.c correct chip ID found, device available
2467 -56 common/cmd_nand.c Error reading Image Header on boot device
2468 56 common/cmd_nand.c reading Image Header from NAND device OK
2469 -57 common/cmd_nand.c Image header has bad magic number
2470 57 common/cmd_nand.c Image header has correct magic number
2471 -58 common/cmd_nand.c Error reading Image from NAND device
2472 58 common/cmd_nand.c reading Image from NAND device OK
2474 -60 common/env_common.c Environment has a bad CRC, using default
2476 64 net/eth.c starting with Ethernet configuration.
2477 -64 net/eth.c no Ethernet found.
2478 65 net/eth.c Ethernet found.
2480 -80 common/cmd_net.c usage wrong
2481 80 common/cmd_net.c before calling NetLoop()
2482 -81 common/cmd_net.c some error in NetLoop() occurred
2483 81 common/cmd_net.c NetLoop() back without error
2484 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2485 82 common/cmd_net.c trying automatic boot
2486 83 common/cmd_net.c running "source" command
2487 -83 common/cmd_net.c some error in automatic boot or "source" command
2488 84 common/cmd_net.c end without errors
2493 100 common/cmd_bootm.c Kernel FIT Image has correct format
2494 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2495 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2496 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2497 102 common/cmd_bootm.c Kernel unit name specified
2498 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2499 103 common/cmd_bootm.c Found configuration node
2500 104 common/cmd_bootm.c Got kernel subimage node offset
2501 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2502 105 common/cmd_bootm.c Kernel subimage hash verification OK
2503 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2504 106 common/cmd_bootm.c Architecture check OK
2505 -106 common/cmd_bootm.c Kernel subimage has wrong type
2506 107 common/cmd_bootm.c Kernel subimage type OK
2507 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2508 108 common/cmd_bootm.c Got kernel subimage data/size
2509 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2510 -109 common/cmd_bootm.c Can't get kernel subimage type
2511 -110 common/cmd_bootm.c Can't get kernel subimage comp
2512 -111 common/cmd_bootm.c Can't get kernel subimage os
2513 -112 common/cmd_bootm.c Can't get kernel subimage load address
2514 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2516 120 common/image.c Start initial ramdisk verification
2517 -120 common/image.c Ramdisk FIT image has incorrect format
2518 121 common/image.c Ramdisk FIT image has correct format
2519 122 common/image.c No ramdisk subimage unit name, using configuration
2520 -122 common/image.c Can't get configuration for ramdisk subimage
2521 123 common/image.c Ramdisk unit name specified
2522 -124 common/image.c Can't get ramdisk subimage node offset
2523 125 common/image.c Got ramdisk subimage node offset
2524 -125 common/image.c Ramdisk subimage hash verification failed
2525 126 common/image.c Ramdisk subimage hash verification OK
2526 -126 common/image.c Ramdisk subimage for unsupported architecture
2527 127 common/image.c Architecture check OK
2528 -127 common/image.c Can't get ramdisk subimage data/size
2529 128 common/image.c Got ramdisk subimage data/size
2530 129 common/image.c Can't get ramdisk load address
2531 -129 common/image.c Got ramdisk load address
2533 -130 common/cmd_doc.c Incorrect FIT image format
2534 131 common/cmd_doc.c FIT image format OK
2536 -140 common/cmd_ide.c Incorrect FIT image format
2537 141 common/cmd_ide.c FIT image format OK
2539 -150 common/cmd_nand.c Incorrect FIT image format
2540 151 common/cmd_nand.c FIT image format OK
2542 - Standalone program support:
2543 CONFIG_STANDALONE_LOAD_ADDR
2545 This option defines a board specific value for the
2546 address where standalone program gets loaded, thus
2547 overwriting the architecture dependent default
2550 - Frame Buffer Address:
2553 Define CONFIG_FB_ADDR if you want to use specific
2554 address for frame buffer.
2555 Then system will reserve the frame buffer address to
2556 defined address instead of lcd_setmem (this function
2557 grabs the memory for frame buffer by panel's size).
2559 Please see board_init_f function.
2561 - Automatic software updates via TFTP server
2563 CONFIG_UPDATE_TFTP_CNT_MAX
2564 CONFIG_UPDATE_TFTP_MSEC_MAX
2566 These options enable and control the auto-update feature;
2567 for a more detailed description refer to doc/README.update.
2569 - MTD Support (mtdparts command, UBI support)
2572 Adds the MTD device infrastructure from the Linux kernel.
2573 Needed for mtdparts command support.
2575 CONFIG_MTD_PARTITIONS
2577 Adds the MTD partitioning infrastructure from the Linux
2578 kernel. Needed for UBI support.
2582 Enable building of SPL globally.
2585 LDSCRIPT for linking the SPL binary.
2588 Maximum binary size (text, data and rodata) of the SPL binary.
2590 CONFIG_SPL_TEXT_BASE
2591 TEXT_BASE for linking the SPL binary.
2593 CONFIG_SPL_BSS_START_ADDR
2594 Link address for the BSS within the SPL binary.
2596 CONFIG_SPL_BSS_MAX_SIZE
2597 Maximum binary size of the BSS section of the SPL binary.
2600 Adress of the start of the stack SPL will use
2602 CONFIG_SYS_SPL_MALLOC_START
2603 Starting address of the malloc pool used in SPL.
2605 CONFIG_SYS_SPL_MALLOC_SIZE
2606 The size of the malloc pool used in SPL.
2608 CONFIG_SPL_FRAMEWORK
2609 Enable the SPL framework under common/. This framework
2610 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2611 NAND loading of the Linux Kernel.
2613 CONFIG_SPL_DISPLAY_PRINT
2614 For ARM, enable an optional function to print more information
2615 about the running system.
2617 CONFIG_SPL_LIBCOMMON_SUPPORT
2618 Support for common/libcommon.o in SPL binary
2620 CONFIG_SPL_LIBDISK_SUPPORT
2621 Support for disk/libdisk.o in SPL binary
2623 CONFIG_SPL_I2C_SUPPORT
2624 Support for drivers/i2c/libi2c.o in SPL binary
2626 CONFIG_SPL_GPIO_SUPPORT
2627 Support for drivers/gpio/libgpio.o in SPL binary
2629 CONFIG_SPL_MMC_SUPPORT
2630 Support for drivers/mmc/libmmc.o in SPL binary
2632 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2633 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2634 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2635 Address, size and partition on the MMC to load U-Boot from
2636 when the MMC is being used in raw mode.
2638 CONFIG_SPL_FAT_SUPPORT
2639 Support for fs/fat/libfat.o in SPL binary
2641 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2642 Filename to read to load U-Boot when reading from FAT
2644 CONFIG_SPL_NAND_SIMPLE
2645 Support for drivers/mtd/nand/libnand.o in SPL binary
2647 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2648 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2649 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2650 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2651 CONFIG_SYS_NAND_ECCBYTES
2652 Defines the size and behavior of the NAND that SPL uses
2653 to read U-Boot with CONFIG_SPL_NAND_SIMPLE
2655 CONFIG_SYS_NAND_U_BOOT_OFFS
2656 Location in NAND for CONFIG_SPL_NAND_SIMPLE to read U-Boot
2659 CONFIG_SYS_NAND_U_BOOT_START
2660 Location in memory for CONFIG_SPL_NAND_SIMPLE to load U-Boot
2663 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2664 Define this if you need to first read the OOB and then the
2665 data. This is used for example on davinci plattforms.
2667 CONFIG_SPL_OMAP3_ID_NAND
2668 Support for an OMAP3-specific set of functions to return the
2669 ID and MFR of the first attached NAND chip, if present.
2671 CONFIG_SPL_SERIAL_SUPPORT
2672 Support for drivers/serial/libserial.o in SPL binary
2674 CONFIG_SPL_SPI_FLASH_SUPPORT
2675 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2677 CONFIG_SPL_SPI_SUPPORT
2678 Support for drivers/spi/libspi.o in SPL binary
2680 CONFIG_SPL_RAM_DEVICE
2681 Support for running image already present in ram, in SPL binary
2683 CONFIG_SPL_LIBGENERIC_SUPPORT
2684 Support for lib/libgeneric.o in SPL binary
2689 [so far only for SMDK2400 boards]
2691 - Modem support enable:
2692 CONFIG_MODEM_SUPPORT
2694 - RTS/CTS Flow control enable:
2697 - Modem debug support:
2698 CONFIG_MODEM_SUPPORT_DEBUG
2700 Enables debugging stuff (char screen[1024], dbg())
2701 for modem support. Useful only with BDI2000.
2703 - Interrupt support (PPC):
2705 There are common interrupt_init() and timer_interrupt()
2706 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2707 for CPU specific initialization. interrupt_init_cpu()
2708 should set decrementer_count to appropriate value. If
2709 CPU resets decrementer automatically after interrupt
2710 (ppc4xx) it should set decrementer_count to zero.
2711 timer_interrupt() calls timer_interrupt_cpu() for CPU
2712 specific handling. If board has watchdog / status_led
2713 / other_activity_monitor it works automatically from
2714 general timer_interrupt().
2718 In the target system modem support is enabled when a
2719 specific key (key combination) is pressed during
2720 power-on. Otherwise U-Boot will boot normally
2721 (autoboot). The key_pressed() function is called from
2722 board_init(). Currently key_pressed() is a dummy
2723 function, returning 1 and thus enabling modem
2726 If there are no modem init strings in the
2727 environment, U-Boot proceed to autoboot; the
2728 previous output (banner, info printfs) will be
2731 See also: doc/README.Modem
2733 Board initialization settings:
2734 ------------------------------
2736 During Initialization u-boot calls a number of board specific functions
2737 to allow the preparation of board specific prerequisites, e.g. pin setup
2738 before drivers are initialized. To enable these callbacks the
2739 following configuration macros have to be defined. Currently this is
2740 architecture specific, so please check arch/your_architecture/lib/board.c
2741 typically in board_init_f() and board_init_r().
2743 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2744 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2745 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2746 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2748 Configuration Settings:
2749 -----------------------
2751 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2752 undefine this when you're short of memory.
2754 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2755 width of the commands listed in the 'help' command output.
2757 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2758 prompt for user input.
2760 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2762 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2764 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2766 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2767 the application (usually a Linux kernel) when it is
2770 - CONFIG_SYS_BAUDRATE_TABLE:
2771 List of legal baudrate settings for this board.
2773 - CONFIG_SYS_CONSOLE_INFO_QUIET
2774 Suppress display of console information at boot.
2776 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2777 If the board specific function
2778 extern int overwrite_console (void);
2779 returns 1, the stdin, stderr and stdout are switched to the
2780 serial port, else the settings in the environment are used.
2782 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2783 Enable the call to overwrite_console().
2785 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2786 Enable overwrite of previous console environment settings.
2788 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2789 Begin and End addresses of the area used by the
2792 - CONFIG_SYS_ALT_MEMTEST:
2793 Enable an alternate, more extensive memory test.
2795 - CONFIG_SYS_MEMTEST_SCRATCH:
2796 Scratch address used by the alternate memory test
2797 You only need to set this if address zero isn't writeable
2799 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2800 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2801 this specified memory area will get subtracted from the top
2802 (end) of RAM and won't get "touched" at all by U-Boot. By
2803 fixing up gd->ram_size the Linux kernel should gets passed
2804 the now "corrected" memory size and won't touch it either.
2805 This should work for arch/ppc and arch/powerpc. Only Linux
2806 board ports in arch/powerpc with bootwrapper support that
2807 recalculate the memory size from the SDRAM controller setup
2808 will have to get fixed in Linux additionally.
2810 This option can be used as a workaround for the 440EPx/GRx
2811 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2814 WARNING: Please make sure that this value is a multiple of
2815 the Linux page size (normally 4k). If this is not the case,
2816 then the end address of the Linux memory will be located at a
2817 non page size aligned address and this could cause major
2820 - CONFIG_SYS_TFTP_LOADADDR:
2821 Default load address for network file downloads
2823 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2824 Enable temporary baudrate change while serial download
2826 - CONFIG_SYS_SDRAM_BASE:
2827 Physical start address of SDRAM. _Must_ be 0 here.
2829 - CONFIG_SYS_MBIO_BASE:
2830 Physical start address of Motherboard I/O (if using a
2833 - CONFIG_SYS_FLASH_BASE:
2834 Physical start address of Flash memory.
2836 - CONFIG_SYS_MONITOR_BASE:
2837 Physical start address of boot monitor code (set by
2838 make config files to be same as the text base address
2839 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2840 CONFIG_SYS_FLASH_BASE when booting from flash.
2842 - CONFIG_SYS_MONITOR_LEN:
2843 Size of memory reserved for monitor code, used to
2844 determine _at_compile_time_ (!) if the environment is
2845 embedded within the U-Boot image, or in a separate
2848 - CONFIG_SYS_MALLOC_LEN:
2849 Size of DRAM reserved for malloc() use.
2851 - CONFIG_SYS_BOOTM_LEN:
2852 Normally compressed uImages are limited to an
2853 uncompressed size of 8 MBytes. If this is not enough,
2854 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2855 to adjust this setting to your needs.
2857 - CONFIG_SYS_BOOTMAPSZ:
2858 Maximum size of memory mapped by the startup code of
2859 the Linux kernel; all data that must be processed by
2860 the Linux kernel (bd_info, boot arguments, FDT blob if
2861 used) must be put below this limit, unless "bootm_low"
2862 enviroment variable is defined and non-zero. In such case
2863 all data for the Linux kernel must be between "bootm_low"
2864 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2865 variable "bootm_mapsize" will override the value of
2866 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2867 then the value in "bootm_size" will be used instead.
2869 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2870 Enable initrd_high functionality. If defined then the
2871 initrd_high feature is enabled and the bootm ramdisk subcommand
2874 - CONFIG_SYS_BOOT_GET_CMDLINE:
2875 Enables allocating and saving kernel cmdline in space between
2876 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2878 - CONFIG_SYS_BOOT_GET_KBD:
2879 Enables allocating and saving a kernel copy of the bd_info in
2880 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2882 - CONFIG_SYS_MAX_FLASH_BANKS:
2883 Max number of Flash memory banks
2885 - CONFIG_SYS_MAX_FLASH_SECT:
2886 Max number of sectors on a Flash chip
2888 - CONFIG_SYS_FLASH_ERASE_TOUT:
2889 Timeout for Flash erase operations (in ms)
2891 - CONFIG_SYS_FLASH_WRITE_TOUT:
2892 Timeout for Flash write operations (in ms)
2894 - CONFIG_SYS_FLASH_LOCK_TOUT
2895 Timeout for Flash set sector lock bit operation (in ms)
2897 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2898 Timeout for Flash clear lock bits operation (in ms)
2900 - CONFIG_SYS_FLASH_PROTECTION
2901 If defined, hardware flash sectors protection is used
2902 instead of U-Boot software protection.
2904 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2906 Enable TFTP transfers directly to flash memory;
2907 without this option such a download has to be
2908 performed in two steps: (1) download to RAM, and (2)
2909 copy from RAM to flash.
2911 The two-step approach is usually more reliable, since
2912 you can check if the download worked before you erase
2913 the flash, but in some situations (when system RAM is
2914 too limited to allow for a temporary copy of the
2915 downloaded image) this option may be very useful.
2917 - CONFIG_SYS_FLASH_CFI:
2918 Define if the flash driver uses extra elements in the
2919 common flash structure for storing flash geometry.
2921 - CONFIG_FLASH_CFI_DRIVER
2922 This option also enables the building of the cfi_flash driver
2923 in the drivers directory
2925 - CONFIG_FLASH_CFI_MTD
2926 This option enables the building of the cfi_mtd driver
2927 in the drivers directory. The driver exports CFI flash
2930 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2931 Use buffered writes to flash.
2933 - CONFIG_FLASH_SPANSION_S29WS_N
2934 s29ws-n MirrorBit flash has non-standard addresses for buffered
2937 - CONFIG_SYS_FLASH_QUIET_TEST
2938 If this option is defined, the common CFI flash doesn't
2939 print it's warning upon not recognized FLASH banks. This
2940 is useful, if some of the configured banks are only
2941 optionally available.
2943 - CONFIG_FLASH_SHOW_PROGRESS
2944 If defined (must be an integer), print out countdown
2945 digits and dots. Recommended value: 45 (9..1) for 80
2946 column displays, 15 (3..1) for 40 column displays.
2948 - CONFIG_SYS_RX_ETH_BUFFER:
2949 Defines the number of Ethernet receive buffers. On some
2950 Ethernet controllers it is recommended to set this value
2951 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2952 buffers can be full shortly after enabling the interface
2953 on high Ethernet traffic.
2954 Defaults to 4 if not defined.
2956 - CONFIG_ENV_MAX_ENTRIES
2958 Maximum number of entries in the hash table that is used
2959 internally to store the environment settings. The default
2960 setting is supposed to be generous and should work in most
2961 cases. This setting can be used to tune behaviour; see
2962 lib/hashtable.c for details.
2964 The following definitions that deal with the placement and management
2965 of environment data (variable area); in general, we support the
2966 following configurations:
2968 - CONFIG_BUILD_ENVCRC:
2970 Builds up envcrc with the target environment so that external utils
2971 may easily extract it and embed it in final U-Boot images.
2973 - CONFIG_ENV_IS_IN_FLASH:
2975 Define this if the environment is in flash memory.
2977 a) The environment occupies one whole flash sector, which is
2978 "embedded" in the text segment with the U-Boot code. This
2979 happens usually with "bottom boot sector" or "top boot
2980 sector" type flash chips, which have several smaller
2981 sectors at the start or the end. For instance, such a
2982 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2983 such a case you would place the environment in one of the
2984 4 kB sectors - with U-Boot code before and after it. With
2985 "top boot sector" type flash chips, you would put the
2986 environment in one of the last sectors, leaving a gap
2987 between U-Boot and the environment.
2989 - CONFIG_ENV_OFFSET:
2991 Offset of environment data (variable area) to the
2992 beginning of flash memory; for instance, with bottom boot
2993 type flash chips the second sector can be used: the offset
2994 for this sector is given here.
2996 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3000 This is just another way to specify the start address of
3001 the flash sector containing the environment (instead of
3004 - CONFIG_ENV_SECT_SIZE:
3006 Size of the sector containing the environment.
3009 b) Sometimes flash chips have few, equal sized, BIG sectors.
3010 In such a case you don't want to spend a whole sector for
3015 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3016 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3017 of this flash sector for the environment. This saves
3018 memory for the RAM copy of the environment.
3020 It may also save flash memory if you decide to use this
3021 when your environment is "embedded" within U-Boot code,
3022 since then the remainder of the flash sector could be used
3023 for U-Boot code. It should be pointed out that this is
3024 STRONGLY DISCOURAGED from a robustness point of view:
3025 updating the environment in flash makes it always
3026 necessary to erase the WHOLE sector. If something goes
3027 wrong before the contents has been restored from a copy in
3028 RAM, your target system will be dead.
3030 - CONFIG_ENV_ADDR_REDUND
3031 CONFIG_ENV_SIZE_REDUND
3033 These settings describe a second storage area used to hold
3034 a redundant copy of the environment data, so that there is
3035 a valid backup copy in case there is a power failure during
3036 a "saveenv" operation.
3038 BE CAREFUL! Any changes to the flash layout, and some changes to the
3039 source code will make it necessary to adapt <board>/u-boot.lds*
3043 - CONFIG_ENV_IS_IN_NVRAM:
3045 Define this if you have some non-volatile memory device
3046 (NVRAM, battery buffered SRAM) which you want to use for the
3052 These two #defines are used to determine the memory area you
3053 want to use for environment. It is assumed that this memory
3054 can just be read and written to, without any special
3057 BE CAREFUL! The first access to the environment happens quite early
3058 in U-Boot initalization (when we try to get the setting of for the
3059 console baudrate). You *MUST* have mapped your NVRAM area then, or
3062 Please note that even with NVRAM we still use a copy of the
3063 environment in RAM: we could work on NVRAM directly, but we want to
3064 keep settings there always unmodified except somebody uses "saveenv"
3065 to save the current settings.
3068 - CONFIG_ENV_IS_IN_EEPROM:
3070 Use this if you have an EEPROM or similar serial access
3071 device and a driver for it.
3073 - CONFIG_ENV_OFFSET:
3076 These two #defines specify the offset and size of the
3077 environment area within the total memory of your EEPROM.
3079 - CONFIG_SYS_I2C_EEPROM_ADDR:
3080 If defined, specified the chip address of the EEPROM device.
3081 The default address is zero.
3083 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3084 If defined, the number of bits used to address bytes in a
3085 single page in the EEPROM device. A 64 byte page, for example
3086 would require six bits.
3088 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3089 If defined, the number of milliseconds to delay between
3090 page writes. The default is zero milliseconds.
3092 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3093 The length in bytes of the EEPROM memory array address. Note
3094 that this is NOT the chip address length!
3096 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3097 EEPROM chips that implement "address overflow" are ones
3098 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3099 address and the extra bits end up in the "chip address" bit
3100 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3103 Note that we consider the length of the address field to
3104 still be one byte because the extra address bits are hidden
3105 in the chip address.
3107 - CONFIG_SYS_EEPROM_SIZE:
3108 The size in bytes of the EEPROM device.
3110 - CONFIG_ENV_EEPROM_IS_ON_I2C
3111 define this, if you have I2C and SPI activated, and your
3112 EEPROM, which holds the environment, is on the I2C bus.
3114 - CONFIG_I2C_ENV_EEPROM_BUS
3115 if you have an Environment on an EEPROM reached over
3116 I2C muxes, you can define here, how to reach this
3117 EEPROM. For example:
3119 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3121 EEPROM which holds the environment, is reached over
3122 a pca9547 i2c mux with address 0x70, channel 3.
3124 - CONFIG_ENV_IS_IN_DATAFLASH:
3126 Define this if you have a DataFlash memory device which you
3127 want to use for the environment.
3129 - CONFIG_ENV_OFFSET:
3133 These three #defines specify the offset and size of the
3134 environment area within the total memory of your DataFlash placed
3135 at the specified address.
3137 - CONFIG_ENV_IS_IN_REMOTE:
3139 Define this if you have a remote memory space which you
3140 want to use for the local device's environment.
3145 These two #defines specify the address and size of the
3146 environment area within the remote memory space. The
3147 local device can get the environment from remote memory
3148 space by SRIO or PCIE links.
3150 BE CAREFUL! For some special cases, the local device can not use
3151 "saveenv" command. For example, the local device will get the
3152 environment stored in a remote NOR flash by SRIO or PCIE link,
3153 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3155 - CONFIG_ENV_IS_IN_NAND:
3157 Define this if you have a NAND device which you want to use
3158 for the environment.
3160 - CONFIG_ENV_OFFSET:
3163 These two #defines specify the offset and size of the environment
3164 area within the first NAND device. CONFIG_ENV_OFFSET must be
3165 aligned to an erase block boundary.
3167 - CONFIG_ENV_OFFSET_REDUND (optional):
3169 This setting describes a second storage area of CONFIG_ENV_SIZE
3170 size used to hold a redundant copy of the environment data, so
3171 that there is a valid backup copy in case there is a power failure
3172 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3173 aligned to an erase block boundary.
3175 - CONFIG_ENV_RANGE (optional):
3177 Specifies the length of the region in which the environment
3178 can be written. This should be a multiple of the NAND device's
3179 block size. Specifying a range with more erase blocks than
3180 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3181 the range to be avoided.
3183 - CONFIG_ENV_OFFSET_OOB (optional):
3185 Enables support for dynamically retrieving the offset of the
3186 environment from block zero's out-of-band data. The
3187 "nand env.oob" command can be used to record this offset.
3188 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3189 using CONFIG_ENV_OFFSET_OOB.
3191 - CONFIG_NAND_ENV_DST
3193 Defines address in RAM to which the nand_spl code should copy the
3194 environment. If redundant environment is used, it will be copied to
3195 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3197 - CONFIG_SYS_SPI_INIT_OFFSET
3199 Defines offset to the initial SPI buffer area in DPRAM. The
3200 area is used at an early stage (ROM part) if the environment
3201 is configured to reside in the SPI EEPROM: We need a 520 byte
3202 scratch DPRAM area. It is used between the two initialization
3203 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3204 to be a good choice since it makes it far enough from the
3205 start of the data area as well as from the stack pointer.
3207 Please note that the environment is read-only until the monitor
3208 has been relocated to RAM and a RAM copy of the environment has been
3209 created; also, when using EEPROM you will have to use getenv_f()
3210 until then to read environment variables.
3212 The environment is protected by a CRC32 checksum. Before the monitor
3213 is relocated into RAM, as a result of a bad CRC you will be working
3214 with the compiled-in default environment - *silently*!!! [This is
3215 necessary, because the first environment variable we need is the
3216 "baudrate" setting for the console - if we have a bad CRC, we don't
3217 have any device yet where we could complain.]
3219 Note: once the monitor has been relocated, then it will complain if
3220 the default environment is used; a new CRC is computed as soon as you
3221 use the "saveenv" command to store a valid environment.
3223 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3224 Echo the inverted Ethernet link state to the fault LED.
3226 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3227 also needs to be defined.
3229 - CONFIG_SYS_FAULT_MII_ADDR:
3230 MII address of the PHY to check for the Ethernet link state.
3232 - CONFIG_NS16550_MIN_FUNCTIONS:
3233 Define this if you desire to only have use of the NS16550_init
3234 and NS16550_putc functions for the serial driver located at
3235 drivers/serial/ns16550.c. This option is useful for saving
3236 space for already greatly restricted images, including but not
3237 limited to NAND_SPL configurations.
3239 Low Level (hardware related) configuration options:
3240 ---------------------------------------------------
3242 - CONFIG_SYS_CACHELINE_SIZE:
3243 Cache Line Size of the CPU.
3245 - CONFIG_SYS_DEFAULT_IMMR:
3246 Default address of the IMMR after system reset.
3248 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3249 and RPXsuper) to be able to adjust the position of
3250 the IMMR register after a reset.
3252 - CONFIG_SYS_CCSRBAR_DEFAULT:
3253 Default (power-on reset) physical address of CCSR on Freescale
3256 - CONFIG_SYS_CCSRBAR:
3257 Virtual address of CCSR. On a 32-bit build, this is typically
3258 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3260 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3261 for cross-platform code that uses that macro instead.
3263 - CONFIG_SYS_CCSRBAR_PHYS:
3264 Physical address of CCSR. CCSR can be relocated to a new
3265 physical address, if desired. In this case, this macro should
3266 be set to that address. Otherwise, it should be set to the
3267 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3268 is typically relocated on 36-bit builds. It is recommended
3269 that this macro be defined via the _HIGH and _LOW macros:
3271 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3272 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3274 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3275 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3276 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3277 used in assembly code, so it must not contain typecasts or
3278 integer size suffixes (e.g. "ULL").
3280 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3281 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3282 used in assembly code, so it must not contain typecasts or
3283 integer size suffixes (e.g. "ULL").
3285 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3286 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3287 forced to a value that ensures that CCSR is not relocated.
3289 - Floppy Disk Support:
3290 CONFIG_SYS_FDC_DRIVE_NUMBER
3292 the default drive number (default value 0)
3294 CONFIG_SYS_ISA_IO_STRIDE
3296 defines the spacing between FDC chipset registers
3299 CONFIG_SYS_ISA_IO_OFFSET
3301 defines the offset of register from address. It
3302 depends on which part of the data bus is connected to
3303 the FDC chipset. (default value 0)
3305 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3306 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3309 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3310 fdc_hw_init() is called at the beginning of the FDC
3311 setup. fdc_hw_init() must be provided by the board
3312 source code. It is used to make hardware dependant
3316 Most IDE controllers were designed to be connected with PCI
3317 interface. Only few of them were designed for AHB interface.
3318 When software is doing ATA command and data transfer to
3319 IDE devices through IDE-AHB controller, some additional
3320 registers accessing to these kind of IDE-AHB controller
3323 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3324 DO NOT CHANGE unless you know exactly what you're
3325 doing! (11-4) [MPC8xx/82xx systems only]
3327 - CONFIG_SYS_INIT_RAM_ADDR:
3329 Start address of memory area that can be used for
3330 initial data and stack; please note that this must be
3331 writable memory that is working WITHOUT special
3332 initialization, i. e. you CANNOT use normal RAM which
3333 will become available only after programming the
3334 memory controller and running certain initialization
3337 U-Boot uses the following memory types:
3338 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3339 - MPC824X: data cache
3340 - PPC4xx: data cache
3342 - CONFIG_SYS_GBL_DATA_OFFSET:
3344 Offset of the initial data structure in the memory
3345 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3346 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3347 data is located at the end of the available space
3348 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3349 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3350 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3351 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3354 On the MPC824X (or other systems that use the data
3355 cache for initial memory) the address chosen for
3356 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3357 point to an otherwise UNUSED address space between
3358 the top of RAM and the start of the PCI space.
3360 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3362 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3364 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3366 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3368 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3370 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3372 - CONFIG_SYS_OR_TIMING_SDRAM:
3375 - CONFIG_SYS_MAMR_PTA:
3376 periodic timer for refresh
3378 - CONFIG_SYS_DER: Debug Event Register (37-47)
3380 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3381 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3382 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3383 CONFIG_SYS_BR1_PRELIM:
3384 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3386 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3387 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3388 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3389 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3391 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3392 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3393 Machine Mode Register and Memory Periodic Timer
3394 Prescaler definitions (SDRAM timing)
3396 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3397 enable I2C microcode relocation patch (MPC8xx);
3398 define relocation offset in DPRAM [DSP2]
3400 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3401 enable SMC microcode relocation patch (MPC8xx);
3402 define relocation offset in DPRAM [SMC1]
3404 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3405 enable SPI microcode relocation patch (MPC8xx);
3406 define relocation offset in DPRAM [SCC4]
3408 - CONFIG_SYS_USE_OSCCLK:
3409 Use OSCM clock mode on MBX8xx board. Be careful,
3410 wrong setting might damage your board. Read
3411 doc/README.MBX before setting this variable!
3413 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3414 Offset of the bootmode word in DPRAM used by post
3415 (Power On Self Tests). This definition overrides
3416 #define'd default value in commproc.h resp.
3419 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3420 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3421 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3422 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3423 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3424 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3425 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3426 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3427 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3429 - CONFIG_PCI_DISABLE_PCIE:
3430 Disable PCI-Express on systems where it is supported but not
3433 - CONFIG_PCI_ENUM_ONLY
3434 Only scan through and get the devices on the busses.
3435 Don't do any setup work, presumably because someone or
3436 something has already done it, and we don't need to do it
3437 a second time. Useful for platforms that are pre-booted
3438 by coreboot or similar.
3441 Chip has SRIO or not
3444 Board has SRIO 1 port available
3447 Board has SRIO 2 port available
3449 - CONFIG_SYS_SRIOn_MEM_VIRT:
3450 Virtual Address of SRIO port 'n' memory region
3452 - CONFIG_SYS_SRIOn_MEM_PHYS:
3453 Physical Address of SRIO port 'n' memory region
3455 - CONFIG_SYS_SRIOn_MEM_SIZE:
3456 Size of SRIO port 'n' memory region
3458 - CONFIG_SYS_NDFC_16
3459 Defined to tell the NDFC that the NAND chip is using a
3462 - CONFIG_SYS_NDFC_EBC0_CFG
3463 Sets the EBC0_CFG register for the NDFC. If not defined
3464 a default value will be used.
3467 Get DDR timing information from an I2C EEPROM. Common
3468 with pluggable memory modules such as SODIMMs
3471 I2C address of the SPD EEPROM
3473 - CONFIG_SYS_SPD_BUS_NUM
3474 If SPD EEPROM is on an I2C bus other than the first
3475 one, specify here. Note that the value must resolve
3476 to something your driver can deal with.
3478 - CONFIG_SYS_DDR_RAW_TIMING
3479 Get DDR timing information from other than SPD. Common with
3480 soldered DDR chips onboard without SPD. DDR raw timing
3481 parameters are extracted from datasheet and hard-coded into
3482 header files or board specific files.
3484 - CONFIG_FSL_DDR_INTERACTIVE
3485 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3487 - CONFIG_SYS_83XX_DDR_USES_CS0
3488 Only for 83xx systems. If specified, then DDR should
3489 be configured using CS0 and CS1 instead of CS2 and CS3.
3491 - CONFIG_ETHER_ON_FEC[12]
3492 Define to enable FEC[12] on a 8xx series processor.
3494 - CONFIG_FEC[12]_PHY
3495 Define to the hardcoded PHY address which corresponds
3496 to the given FEC; i. e.
3497 #define CONFIG_FEC1_PHY 4
3498 means that the PHY with address 4 is connected to FEC1
3500 When set to -1, means to probe for first available.
3502 - CONFIG_FEC[12]_PHY_NORXERR
3503 The PHY does not have a RXERR line (RMII only).
3504 (so program the FEC to ignore it).
3507 Enable RMII mode for all FECs.
3508 Note that this is a global option, we can't
3509 have one FEC in standard MII mode and another in RMII mode.
3511 - CONFIG_CRC32_VERIFY
3512 Add a verify option to the crc32 command.
3515 => crc32 -v <address> <count> <crc32>
3517 Where address/count indicate a memory area
3518 and crc32 is the correct crc32 which the
3522 Add the "loopw" memory command. This only takes effect if
3523 the memory commands are activated globally (CONFIG_CMD_MEM).
3526 Add the "mdc" and "mwc" memory commands. These are cyclic
3531 This command will print 4 bytes (10,11,12,13) each 500 ms.
3533 => mwc.l 100 12345678 10
3534 This command will write 12345678 to address 100 all 10 ms.
3536 This only takes effect if the memory commands are activated
3537 globally (CONFIG_CMD_MEM).
3539 - CONFIG_SKIP_LOWLEVEL_INIT
3540 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3541 low level initializations (like setting up the memory
3542 controller) are omitted and/or U-Boot does not
3543 relocate itself into RAM.
3545 Normally this variable MUST NOT be defined. The only
3546 exception is when U-Boot is loaded (to RAM) by some
3547 other boot loader or by a debugger which performs
3548 these initializations itself.
3551 Modifies the behaviour of start.S when compiling a loader
3552 that is executed before the actual U-Boot. E.g. when
3553 compiling a NAND SPL.
3555 - CONFIG_USE_ARCH_MEMCPY
3556 CONFIG_USE_ARCH_MEMSET
3557 If these options are used a optimized version of memcpy/memset will
3558 be used if available. These functions may be faster under some
3559 conditions but may increase the binary size.
3561 Freescale QE/FMAN Firmware Support:
3562 -----------------------------------
3564 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3565 loading of "firmware", which is encoded in the QE firmware binary format.
3566 This firmware often needs to be loaded during U-Boot booting, so macros
3567 are used to identify the storage device (NOR flash, SPI, etc) and the address
3570 - CONFIG_SYS_QE_FMAN_FW_ADDR
3571 The address in the storage device where the firmware is located. The
3572 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3575 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3576 The maximum possible size of the firmware. The firmware binary format
3577 has a field that specifies the actual size of the firmware, but it
3578 might not be possible to read any part of the firmware unless some
3579 local storage is allocated to hold the entire firmware first.
3581 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3582 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3583 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3584 virtual address in NOR flash.
3586 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3587 Specifies that QE/FMAN firmware is located in NAND flash.
3588 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3590 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3591 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3592 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3594 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3595 Specifies that QE/FMAN firmware is located on the primary SPI
3596 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3598 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3599 Specifies that QE/FMAN firmware is located in the remote (master)
3600 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3601 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3602 window->master inbound window->master LAW->the ucode address in
3603 master's memory space.
3605 Building the Software:
3606 ======================
3608 Building U-Boot has been tested in several native build environments
3609 and in many different cross environments. Of course we cannot support
3610 all possibly existing versions of cross development tools in all
3611 (potentially obsolete) versions. In case of tool chain problems we
3612 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3613 which is extensively used to build and test U-Boot.
3615 If you are not using a native environment, it is assumed that you
3616 have GNU cross compiling tools available in your path. In this case,
3617 you must set the environment variable CROSS_COMPILE in your shell.
3618 Note that no changes to the Makefile or any other source files are
3619 necessary. For example using the ELDK on a 4xx CPU, please enter:
3621 $ CROSS_COMPILE=ppc_4xx-
3622 $ export CROSS_COMPILE
3624 Note: If you wish to generate Windows versions of the utilities in
3625 the tools directory you can use the MinGW toolchain
3626 (http://www.mingw.org). Set your HOST tools to the MinGW
3627 toolchain and execute 'make tools'. For example:
3629 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3631 Binaries such as tools/mkimage.exe will be created which can
3632 be executed on computers running Windows.
3634 U-Boot is intended to be simple to build. After installing the
3635 sources you must configure U-Boot for one specific board type. This
3640 where "NAME_config" is the name of one of the existing configu-
3641 rations; see boards.cfg for supported names.
3643 Note: for some board special configuration names may exist; check if
3644 additional information is available from the board vendor; for
3645 instance, the TQM823L systems are available without (standard)
3646 or with LCD support. You can select such additional "features"
3647 when choosing the configuration, i. e.
3650 - will configure for a plain TQM823L, i. e. no LCD support
3652 make TQM823L_LCD_config
3653 - will configure for a TQM823L with U-Boot console on LCD
3658 Finally, type "make all", and you should get some working U-Boot
3659 images ready for download to / installation on your system:
3661 - "u-boot.bin" is a raw binary image
3662 - "u-boot" is an image in ELF binary format
3663 - "u-boot.srec" is in Motorola S-Record format
3665 By default the build is performed locally and the objects are saved
3666 in the source directory. One of the two methods can be used to change
3667 this behavior and build U-Boot to some external directory:
3669 1. Add O= to the make command line invocations:
3671 make O=/tmp/build distclean
3672 make O=/tmp/build NAME_config
3673 make O=/tmp/build all
3675 2. Set environment variable BUILD_DIR to point to the desired location:
3677 export BUILD_DIR=/tmp/build
3682 Note that the command line "O=" setting overrides the BUILD_DIR environment
3686 Please be aware that the Makefiles assume you are using GNU make, so
3687 for instance on NetBSD you might need to use "gmake" instead of
3691 If the system board that you have is not listed, then you will need
3692 to port U-Boot to your hardware platform. To do this, follow these
3695 1. Add a new configuration option for your board to the toplevel
3696 "boards.cfg" file, using the existing entries as examples.
3697 Follow the instructions there to keep the boards in order.
3698 2. Create a new directory to hold your board specific code. Add any
3699 files you need. In your board directory, you will need at least
3700 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3701 3. Create a new configuration file "include/configs/<board>.h" for
3703 3. If you're porting U-Boot to a new CPU, then also create a new
3704 directory to hold your CPU specific code. Add any files you need.
3705 4. Run "make <board>_config" with your new name.
3706 5. Type "make", and you should get a working "u-boot.srec" file
3707 to be installed on your target system.
3708 6. Debug and solve any problems that might arise.
3709 [Of course, this last step is much harder than it sounds.]
3712 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3713 ==============================================================
3715 If you have modified U-Boot sources (for instance added a new board
3716 or support for new devices, a new CPU, etc.) you are expected to
3717 provide feedback to the other developers. The feedback normally takes
3718 the form of a "patch", i. e. a context diff against a certain (latest
3719 official or latest in the git repository) version of U-Boot sources.
3721 But before you submit such a patch, please verify that your modifi-
3722 cation did not break existing code. At least make sure that *ALL* of
3723 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3724 just run the "MAKEALL" script, which will configure and build U-Boot
3725 for ALL supported system. Be warned, this will take a while. You can
3726 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3727 environment variable to the script, i. e. to use the ELDK cross tools
3730 CROSS_COMPILE=ppc_8xx- MAKEALL
3732 or to build on a native PowerPC system you can type
3734 CROSS_COMPILE=' ' MAKEALL
3736 When using the MAKEALL script, the default behaviour is to build
3737 U-Boot in the source directory. This location can be changed by
3738 setting the BUILD_DIR environment variable. Also, for each target
3739 built, the MAKEALL script saves two log files (<target>.ERR and
3740 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3741 location can be changed by setting the MAKEALL_LOGDIR environment
3742 variable. For example:
3744 export BUILD_DIR=/tmp/build
3745 export MAKEALL_LOGDIR=/tmp/log
3746 CROSS_COMPILE=ppc_8xx- MAKEALL
3748 With the above settings build objects are saved in the /tmp/build,
3749 log files are saved in the /tmp/log and the source tree remains clean
3750 during the whole build process.
3753 See also "U-Boot Porting Guide" below.
3756 Monitor Commands - Overview:
3757 ============================
3759 go - start application at address 'addr'
3760 run - run commands in an environment variable
3761 bootm - boot application image from memory
3762 bootp - boot image via network using BootP/TFTP protocol
3763 bootz - boot zImage from memory
3764 tftpboot- boot image via network using TFTP protocol
3765 and env variables "ipaddr" and "serverip"
3766 (and eventually "gatewayip")
3767 tftpput - upload a file via network using TFTP protocol
3768 rarpboot- boot image via network using RARP/TFTP protocol
3769 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3770 loads - load S-Record file over serial line
3771 loadb - load binary file over serial line (kermit mode)
3773 mm - memory modify (auto-incrementing)
3774 nm - memory modify (constant address)
3775 mw - memory write (fill)
3777 cmp - memory compare
3778 crc32 - checksum calculation
3779 i2c - I2C sub-system
3780 sspi - SPI utility commands
3781 base - print or set address offset
3782 printenv- print environment variables
3783 setenv - set environment variables
3784 saveenv - save environment variables to persistent storage
3785 protect - enable or disable FLASH write protection
3786 erase - erase FLASH memory
3787 flinfo - print FLASH memory information
3788 bdinfo - print Board Info structure
3789 iminfo - print header information for application image
3790 coninfo - print console devices and informations
3791 ide - IDE sub-system
3792 loop - infinite loop on address range
3793 loopw - infinite write loop on address range
3794 mtest - simple RAM test
3795 icache - enable or disable instruction cache
3796 dcache - enable or disable data cache
3797 reset - Perform RESET of the CPU
3798 echo - echo args to console
3799 version - print monitor version
3800 help - print online help
3801 ? - alias for 'help'
3804 Monitor Commands - Detailed Description:
3805 ========================================
3809 For now: just type "help <command>".
3812 Environment Variables:
3813 ======================
3815 U-Boot supports user configuration using Environment Variables which
3816 can be made persistent by saving to Flash memory.
3818 Environment Variables are set using "setenv", printed using
3819 "printenv", and saved to Flash using "saveenv". Using "setenv"
3820 without a value can be used to delete a variable from the
3821 environment. As long as you don't save the environment you are
3822 working with an in-memory copy. In case the Flash area containing the
3823 environment is erased by accident, a default environment is provided.
3825 Some configuration options can be set using Environment Variables.
3827 List of environment variables (most likely not complete):
3829 baudrate - see CONFIG_BAUDRATE
3831 bootdelay - see CONFIG_BOOTDELAY
3833 bootcmd - see CONFIG_BOOTCOMMAND
3835 bootargs - Boot arguments when booting an RTOS image
3837 bootfile - Name of the image to load with TFTP
3839 bootm_low - Memory range available for image processing in the bootm
3840 command can be restricted. This variable is given as
3841 a hexadecimal number and defines lowest address allowed
3842 for use by the bootm command. See also "bootm_size"
3843 environment variable. Address defined by "bootm_low" is
3844 also the base of the initial memory mapping for the Linux
3845 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3848 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3849 This variable is given as a hexadecimal number and it
3850 defines the size of the memory region starting at base
3851 address bootm_low that is accessible by the Linux kernel
3852 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3853 as the default value if it is defined, and bootm_size is
3856 bootm_size - Memory range available for image processing in the bootm
3857 command can be restricted. This variable is given as
3858 a hexadecimal number and defines the size of the region
3859 allowed for use by the bootm command. See also "bootm_low"
3860 environment variable.
3862 updatefile - Location of the software update file on a TFTP server, used
3863 by the automatic software update feature. Please refer to
3864 documentation in doc/README.update for more details.
3866 autoload - if set to "no" (any string beginning with 'n'),
3867 "bootp" will just load perform a lookup of the
3868 configuration from the BOOTP server, but not try to
3869 load any image using TFTP
3871 autostart - if set to "yes", an image loaded using the "bootp",
3872 "rarpboot", "tftpboot" or "diskboot" commands will
3873 be automatically started (by internally calling
3876 If set to "no", a standalone image passed to the
3877 "bootm" command will be copied to the load address
3878 (and eventually uncompressed), but NOT be started.
3879 This can be used to load and uncompress arbitrary
3882 fdt_high - if set this restricts the maximum address that the
3883 flattened device tree will be copied into upon boot.
3884 For example, if you have a system with 1 GB memory
3885 at physical address 0x10000000, while Linux kernel
3886 only recognizes the first 704 MB as low memory, you
3887 may need to set fdt_high as 0x3C000000 to have the
3888 device tree blob be copied to the maximum address
3889 of the 704 MB low memory, so that Linux kernel can
3890 access it during the boot procedure.
3892 If this is set to the special value 0xFFFFFFFF then
3893 the fdt will not be copied at all on boot. For this
3894 to work it must reside in writable memory, have
3895 sufficient padding on the end of it for u-boot to
3896 add the information it needs into it, and the memory
3897 must be accessible by the kernel.
3899 fdtcontroladdr- if set this is the address of the control flattened
3900 device tree used by U-Boot when CONFIG_OF_CONTROL is
3903 i2cfast - (PPC405GP|PPC405EP only)
3904 if set to 'y' configures Linux I2C driver for fast
3905 mode (400kHZ). This environment variable is used in
3906 initialization code. So, for changes to be effective
3907 it must be saved and board must be reset.
3909 initrd_high - restrict positioning of initrd images:
3910 If this variable is not set, initrd images will be
3911 copied to the highest possible address in RAM; this
3912 is usually what you want since it allows for
3913 maximum initrd size. If for some reason you want to
3914 make sure that the initrd image is loaded below the
3915 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3916 variable to a value of "no" or "off" or "0".
3917 Alternatively, you can set it to a maximum upper
3918 address to use (U-Boot will still check that it
3919 does not overwrite the U-Boot stack and data).
3921 For instance, when you have a system with 16 MB
3922 RAM, and want to reserve 4 MB from use by Linux,
3923 you can do this by adding "mem=12M" to the value of
3924 the "bootargs" variable. However, now you must make
3925 sure that the initrd image is placed in the first
3926 12 MB as well - this can be done with
3928 setenv initrd_high 00c00000
3930 If you set initrd_high to 0xFFFFFFFF, this is an
3931 indication to U-Boot that all addresses are legal
3932 for the Linux kernel, including addresses in flash
3933 memory. In this case U-Boot will NOT COPY the
3934 ramdisk at all. This may be useful to reduce the
3935 boot time on your system, but requires that this
3936 feature is supported by your Linux kernel.
3938 ipaddr - IP address; needed for tftpboot command
3940 loadaddr - Default load address for commands like "bootp",
3941 "rarpboot", "tftpboot", "loadb" or "diskboot"
3943 loads_echo - see CONFIG_LOADS_ECHO
3945 serverip - TFTP server IP address; needed for tftpboot command
3947 bootretry - see CONFIG_BOOT_RETRY_TIME
3949 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3951 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3953 ethprime - controls which interface is used first.
3955 ethact - controls which interface is currently active.
3956 For example you can do the following
3958 => setenv ethact FEC
3959 => ping 192.168.0.1 # traffic sent on FEC
3960 => setenv ethact SCC
3961 => ping 10.0.0.1 # traffic sent on SCC
3963 ethrotate - When set to "no" U-Boot does not go through all
3964 available network interfaces.
3965 It just stays at the currently selected interface.
3967 netretry - When set to "no" each network operation will
3968 either succeed or fail without retrying.
3969 When set to "once" the network operation will
3970 fail when all the available network interfaces
3971 are tried once without success.
3972 Useful on scripts which control the retry operation
3975 npe_ucode - set load address for the NPE microcode
3977 tftpsrcport - If this is set, the value is used for TFTP's
3980 tftpdstport - If this is set, the value is used for TFTP's UDP
3981 destination port instead of the Well Know Port 69.
3983 tftpblocksize - Block size to use for TFTP transfers; if not set,
3984 we use the TFTP server's default block size
3986 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3987 seconds, minimum value is 1000 = 1 second). Defines
3988 when a packet is considered to be lost so it has to
3989 be retransmitted. The default is 5000 = 5 seconds.
3990 Lowering this value may make downloads succeed
3991 faster in networks with high packet loss rates or
3992 with unreliable TFTP servers.
3994 vlan - When set to a value < 4095 the traffic over
3995 Ethernet is encapsulated/received over 802.1q
3998 The following image location variables contain the location of images
3999 used in booting. The "Image" column gives the role of the image and is
4000 not an environment variable name. The other columns are environment
4001 variable names. "File Name" gives the name of the file on a TFTP
4002 server, "RAM Address" gives the location in RAM the image will be
4003 loaded to, and "Flash Location" gives the image's address in NOR
4004 flash or offset in NAND flash.
4006 *Note* - these variables don't have to be defined for all boards, some
4007 boards currenlty use other variables for these purposes, and some
4008 boards use these variables for other purposes.
4010 Image File Name RAM Address Flash Location
4011 ----- --------- ----------- --------------
4012 u-boot u-boot u-boot_addr_r u-boot_addr
4013 Linux kernel bootfile kernel_addr_r kernel_addr
4014 device tree blob fdtfile fdt_addr_r fdt_addr
4015 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4017 The following environment variables may be used and automatically
4018 updated by the network boot commands ("bootp" and "rarpboot"),
4019 depending the information provided by your boot server:
4021 bootfile - see above
4022 dnsip - IP address of your Domain Name Server
4023 dnsip2 - IP address of your secondary Domain Name Server
4024 gatewayip - IP address of the Gateway (Router) to use
4025 hostname - Target hostname
4027 netmask - Subnet Mask
4028 rootpath - Pathname of the root filesystem on the NFS server
4029 serverip - see above
4032 There are two special Environment Variables:
4034 serial# - contains hardware identification information such
4035 as type string and/or serial number
4036 ethaddr - Ethernet address
4038 These variables can be set only once (usually during manufacturing of
4039 the board). U-Boot refuses to delete or overwrite these variables
4040 once they have been set once.
4043 Further special Environment Variables:
4045 ver - Contains the U-Boot version string as printed
4046 with the "version" command. This variable is
4047 readonly (see CONFIG_VERSION_VARIABLE).
4050 Please note that changes to some configuration parameters may take
4051 only effect after the next boot (yes, that's just like Windoze :-).
4054 Command Line Parsing:
4055 =====================
4057 There are two different command line parsers available with U-Boot:
4058 the old "simple" one, and the much more powerful "hush" shell:
4060 Old, simple command line parser:
4061 --------------------------------
4063 - supports environment variables (through setenv / saveenv commands)
4064 - several commands on one line, separated by ';'
4065 - variable substitution using "... ${name} ..." syntax
4066 - special characters ('$', ';') can be escaped by prefixing with '\',
4068 setenv bootcmd bootm \${address}
4069 - You can also escape text by enclosing in single apostrophes, for example:
4070 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4075 - similar to Bourne shell, with control structures like
4076 if...then...else...fi, for...do...done; while...do...done,
4077 until...do...done, ...
4078 - supports environment ("global") variables (through setenv / saveenv
4079 commands) and local shell variables (through standard shell syntax
4080 "name=value"); only environment variables can be used with "run"
4086 (1) If a command line (or an environment variable executed by a "run"
4087 command) contains several commands separated by semicolon, and
4088 one of these commands fails, then the remaining commands will be
4091 (2) If you execute several variables with one call to run (i. e.
4092 calling run with a list of variables as arguments), any failing
4093 command will cause "run" to terminate, i. e. the remaining
4094 variables are not executed.
4096 Note for Redundant Ethernet Interfaces:
4097 =======================================
4099 Some boards come with redundant Ethernet interfaces; U-Boot supports
4100 such configurations and is capable of automatic selection of a
4101 "working" interface when needed. MAC assignment works as follows:
4103 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4104 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4105 "eth1addr" (=>eth1), "eth2addr", ...
4107 If the network interface stores some valid MAC address (for instance
4108 in SROM), this is used as default address if there is NO correspon-
4109 ding setting in the environment; if the corresponding environment
4110 variable is set, this overrides the settings in the card; that means:
4112 o If the SROM has a valid MAC address, and there is no address in the
4113 environment, the SROM's address is used.
4115 o If there is no valid address in the SROM, and a definition in the
4116 environment exists, then the value from the environment variable is
4119 o If both the SROM and the environment contain a MAC address, and
4120 both addresses are the same, this MAC address is used.
4122 o If both the SROM and the environment contain a MAC address, and the
4123 addresses differ, the value from the environment is used and a
4126 o If neither SROM nor the environment contain a MAC address, an error
4129 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4130 will be programmed into hardware as part of the initialization process. This
4131 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4132 The naming convention is as follows:
4133 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4138 U-Boot is capable of booting (and performing other auxiliary operations on)
4139 images in two formats:
4141 New uImage format (FIT)
4142 -----------------------
4144 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4145 to Flattened Device Tree). It allows the use of images with multiple
4146 components (several kernels, ramdisks, etc.), with contents protected by
4147 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4153 Old image format is based on binary files which can be basically anything,
4154 preceded by a special header; see the definitions in include/image.h for
4155 details; basically, the header defines the following image properties:
4157 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4158 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4159 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4160 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4162 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4163 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4164 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4165 * Compression Type (uncompressed, gzip, bzip2)
4171 The header is marked by a special Magic Number, and both the header
4172 and the data portions of the image are secured against corruption by
4179 Although U-Boot should support any OS or standalone application
4180 easily, the main focus has always been on Linux during the design of
4183 U-Boot includes many features that so far have been part of some
4184 special "boot loader" code within the Linux kernel. Also, any
4185 "initrd" images to be used are no longer part of one big Linux image;
4186 instead, kernel and "initrd" are separate images. This implementation
4187 serves several purposes:
4189 - the same features can be used for other OS or standalone
4190 applications (for instance: using compressed images to reduce the
4191 Flash memory footprint)
4193 - it becomes much easier to port new Linux kernel versions because
4194 lots of low-level, hardware dependent stuff are done by U-Boot
4196 - the same Linux kernel image can now be used with different "initrd"
4197 images; of course this also means that different kernel images can
4198 be run with the same "initrd". This makes testing easier (you don't
4199 have to build a new "zImage.initrd" Linux image when you just
4200 change a file in your "initrd"). Also, a field-upgrade of the
4201 software is easier now.
4207 Porting Linux to U-Boot based systems:
4208 ---------------------------------------
4210 U-Boot cannot save you from doing all the necessary modifications to
4211 configure the Linux device drivers for use with your target hardware
4212 (no, we don't intend to provide a full virtual machine interface to
4215 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4217 Just make sure your machine specific header file (for instance
4218 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4219 Information structure as we define in include/asm-<arch>/u-boot.h,
4220 and make sure that your definition of IMAP_ADDR uses the same value
4221 as your U-Boot configuration in CONFIG_SYS_IMMR.
4224 Configuring the Linux kernel:
4225 -----------------------------
4227 No specific requirements for U-Boot. Make sure you have some root
4228 device (initial ramdisk, NFS) for your target system.
4231 Building a Linux Image:
4232 -----------------------
4234 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4235 not used. If you use recent kernel source, a new build target
4236 "uImage" will exist which automatically builds an image usable by
4237 U-Boot. Most older kernels also have support for a "pImage" target,
4238 which was introduced for our predecessor project PPCBoot and uses a
4239 100% compatible format.
4248 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4249 encapsulate a compressed Linux kernel image with header information,
4250 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4252 * build a standard "vmlinux" kernel image (in ELF binary format):
4254 * convert the kernel into a raw binary image:
4256 ${CROSS_COMPILE}-objcopy -O binary \
4257 -R .note -R .comment \
4258 -S vmlinux linux.bin
4260 * compress the binary image:
4264 * package compressed binary image for U-Boot:
4266 mkimage -A ppc -O linux -T kernel -C gzip \
4267 -a 0 -e 0 -n "Linux Kernel Image" \
4268 -d linux.bin.gz uImage
4271 The "mkimage" tool can also be used to create ramdisk images for use
4272 with U-Boot, either separated from the Linux kernel image, or
4273 combined into one file. "mkimage" encapsulates the images with a 64
4274 byte header containing information about target architecture,
4275 operating system, image type, compression method, entry points, time
4276 stamp, CRC32 checksums, etc.
4278 "mkimage" can be called in two ways: to verify existing images and
4279 print the header information, or to build new images.
4281 In the first form (with "-l" option) mkimage lists the information
4282 contained in the header of an existing U-Boot image; this includes
4283 checksum verification:
4285 tools/mkimage -l image
4286 -l ==> list image header information
4288 The second form (with "-d" option) is used to build a U-Boot image
4289 from a "data file" which is used as image payload:
4291 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4292 -n name -d data_file image
4293 -A ==> set architecture to 'arch'
4294 -O ==> set operating system to 'os'
4295 -T ==> set image type to 'type'
4296 -C ==> set compression type 'comp'
4297 -a ==> set load address to 'addr' (hex)
4298 -e ==> set entry point to 'ep' (hex)
4299 -n ==> set image name to 'name'
4300 -d ==> use image data from 'datafile'
4302 Right now, all Linux kernels for PowerPC systems use the same load
4303 address (0x00000000), but the entry point address depends on the
4306 - 2.2.x kernels have the entry point at 0x0000000C,
4307 - 2.3.x and later kernels have the entry point at 0x00000000.
4309 So a typical call to build a U-Boot image would read:
4311 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4312 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4313 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4314 > examples/uImage.TQM850L
4315 Image Name: 2.4.4 kernel for TQM850L
4316 Created: Wed Jul 19 02:34:59 2000
4317 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4318 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4319 Load Address: 0x00000000
4320 Entry Point: 0x00000000
4322 To verify the contents of the image (or check for corruption):
4324 -> tools/mkimage -l examples/uImage.TQM850L
4325 Image Name: 2.4.4 kernel for TQM850L
4326 Created: Wed Jul 19 02:34:59 2000
4327 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4328 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4329 Load Address: 0x00000000
4330 Entry Point: 0x00000000
4332 NOTE: for embedded systems where boot time is critical you can trade
4333 speed for memory and install an UNCOMPRESSED image instead: this
4334 needs more space in Flash, but boots much faster since it does not
4335 need to be uncompressed:
4337 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4338 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4339 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4340 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4341 > examples/uImage.TQM850L-uncompressed
4342 Image Name: 2.4.4 kernel for TQM850L
4343 Created: Wed Jul 19 02:34:59 2000
4344 Image Type: PowerPC Linux Kernel Image (uncompressed)
4345 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4346 Load Address: 0x00000000
4347 Entry Point: 0x00000000
4350 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4351 when your kernel is intended to use an initial ramdisk:
4353 -> tools/mkimage -n 'Simple Ramdisk Image' \
4354 > -A ppc -O linux -T ramdisk -C gzip \
4355 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4356 Image Name: Simple Ramdisk Image
4357 Created: Wed Jan 12 14:01:50 2000
4358 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4359 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4360 Load Address: 0x00000000
4361 Entry Point: 0x00000000
4364 Installing a Linux Image:
4365 -------------------------
4367 To downloading a U-Boot image over the serial (console) interface,
4368 you must convert the image to S-Record format:
4370 objcopy -I binary -O srec examples/image examples/image.srec
4372 The 'objcopy' does not understand the information in the U-Boot
4373 image header, so the resulting S-Record file will be relative to
4374 address 0x00000000. To load it to a given address, you need to
4375 specify the target address as 'offset' parameter with the 'loads'
4378 Example: install the image to address 0x40100000 (which on the
4379 TQM8xxL is in the first Flash bank):
4381 => erase 40100000 401FFFFF
4387 ## Ready for S-Record download ...
4388 ~>examples/image.srec
4389 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4391 15989 15990 15991 15992
4392 [file transfer complete]
4394 ## Start Addr = 0x00000000
4397 You can check the success of the download using the 'iminfo' command;
4398 this includes a checksum verification so you can be sure no data
4399 corruption happened:
4403 ## Checking Image at 40100000 ...
4404 Image Name: 2.2.13 for initrd on TQM850L
4405 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4406 Data Size: 335725 Bytes = 327 kB = 0 MB
4407 Load Address: 00000000
4408 Entry Point: 0000000c
4409 Verifying Checksum ... OK
4415 The "bootm" command is used to boot an application that is stored in
4416 memory (RAM or Flash). In case of a Linux kernel image, the contents
4417 of the "bootargs" environment variable is passed to the kernel as
4418 parameters. You can check and modify this variable using the
4419 "printenv" and "setenv" commands:
4422 => printenv bootargs
4423 bootargs=root=/dev/ram
4425 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4427 => printenv bootargs
4428 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4431 ## Booting Linux kernel at 40020000 ...
4432 Image Name: 2.2.13 for NFS on TQM850L
4433 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4434 Data Size: 381681 Bytes = 372 kB = 0 MB
4435 Load Address: 00000000
4436 Entry Point: 0000000c
4437 Verifying Checksum ... OK
4438 Uncompressing Kernel Image ... OK
4439 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
4440 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4441 time_init: decrementer frequency = 187500000/60
4442 Calibrating delay loop... 49.77 BogoMIPS
4443 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4446 If you want to boot a Linux kernel with initial RAM disk, you pass
4447 the memory addresses of both the kernel and the initrd image (PPBCOOT
4448 format!) to the "bootm" command:
4450 => imi 40100000 40200000
4452 ## Checking Image at 40100000 ...
4453 Image Name: 2.2.13 for initrd on TQM850L
4454 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4455 Data Size: 335725 Bytes = 327 kB = 0 MB
4456 Load Address: 00000000
4457 Entry Point: 0000000c
4458 Verifying Checksum ... OK
4460 ## Checking Image at 40200000 ...
4461 Image Name: Simple Ramdisk Image
4462 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4463 Data Size: 566530 Bytes = 553 kB = 0 MB
4464 Load Address: 00000000
4465 Entry Point: 00000000
4466 Verifying Checksum ... OK
4468 => bootm 40100000 40200000
4469 ## Booting Linux kernel at 40100000 ...
4470 Image Name: 2.2.13 for initrd on TQM850L
4471 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4472 Data Size: 335725 Bytes = 327 kB = 0 MB
4473 Load Address: 00000000
4474 Entry Point: 0000000c
4475 Verifying Checksum ... OK
4476 Uncompressing Kernel Image ... OK
4477 ## Loading RAMDisk Image at 40200000 ...
4478 Image Name: Simple Ramdisk Image
4479 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4480 Data Size: 566530 Bytes = 553 kB = 0 MB
4481 Load Address: 00000000
4482 Entry Point: 00000000
4483 Verifying Checksum ... OK
4484 Loading Ramdisk ... OK
4485 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
4486 Boot arguments: root=/dev/ram
4487 time_init: decrementer frequency = 187500000/60
4488 Calibrating delay loop... 49.77 BogoMIPS
4490 RAMDISK: Compressed image found at block 0
4491 VFS: Mounted root (ext2 filesystem).
4495 Boot Linux and pass a flat device tree:
4498 First, U-Boot must be compiled with the appropriate defines. See the section
4499 titled "Linux Kernel Interface" above for a more in depth explanation. The
4500 following is an example of how to start a kernel and pass an updated
4506 oft=oftrees/mpc8540ads.dtb
4507 => tftp $oftaddr $oft
4508 Speed: 1000, full duplex
4510 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4511 Filename 'oftrees/mpc8540ads.dtb'.
4512 Load address: 0x300000
4515 Bytes transferred = 4106 (100a hex)
4516 => tftp $loadaddr $bootfile
4517 Speed: 1000, full duplex
4519 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4521 Load address: 0x200000
4522 Loading:############
4524 Bytes transferred = 1029407 (fb51f hex)
4529 => bootm $loadaddr - $oftaddr
4530 ## Booting image at 00200000 ...
4531 Image Name: Linux-2.6.17-dirty
4532 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4533 Data Size: 1029343 Bytes = 1005.2 kB
4534 Load Address: 00000000
4535 Entry Point: 00000000
4536 Verifying Checksum ... OK
4537 Uncompressing Kernel Image ... OK
4538 Booting using flat device tree at 0x300000
4539 Using MPC85xx ADS machine description
4540 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4544 More About U-Boot Image Types:
4545 ------------------------------
4547 U-Boot supports the following image types:
4549 "Standalone Programs" are directly runnable in the environment
4550 provided by U-Boot; it is expected that (if they behave
4551 well) you can continue to work in U-Boot after return from
4552 the Standalone Program.
4553 "OS Kernel Images" are usually images of some Embedded OS which
4554 will take over control completely. Usually these programs
4555 will install their own set of exception handlers, device
4556 drivers, set up the MMU, etc. - this means, that you cannot
4557 expect to re-enter U-Boot except by resetting the CPU.
4558 "RAMDisk Images" are more or less just data blocks, and their
4559 parameters (address, size) are passed to an OS kernel that is
4561 "Multi-File Images" contain several images, typically an OS
4562 (Linux) kernel image and one or more data images like
4563 RAMDisks. This construct is useful for instance when you want
4564 to boot over the network using BOOTP etc., where the boot
4565 server provides just a single image file, but you want to get
4566 for instance an OS kernel and a RAMDisk image.
4568 "Multi-File Images" start with a list of image sizes, each
4569 image size (in bytes) specified by an "uint32_t" in network
4570 byte order. This list is terminated by an "(uint32_t)0".
4571 Immediately after the terminating 0 follow the images, one by
4572 one, all aligned on "uint32_t" boundaries (size rounded up to
4573 a multiple of 4 bytes).
4575 "Firmware Images" are binary images containing firmware (like
4576 U-Boot or FPGA images) which usually will be programmed to
4579 "Script files" are command sequences that will be executed by
4580 U-Boot's command interpreter; this feature is especially
4581 useful when you configure U-Boot to use a real shell (hush)
4582 as command interpreter.
4584 Booting the Linux zImage:
4585 -------------------------
4587 On some platforms, it's possible to boot Linux zImage. This is done
4588 using the "bootz" command. The syntax of "bootz" command is the same
4589 as the syntax of "bootm" command.
4591 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4592 kernel with raw initrd images. The syntax is slightly different, the
4593 address of the initrd must be augmented by it's size, in the following
4594 format: "<initrd addres>:<initrd size>".
4600 One of the features of U-Boot is that you can dynamically load and
4601 run "standalone" applications, which can use some resources of
4602 U-Boot like console I/O functions or interrupt services.
4604 Two simple examples are included with the sources:
4609 'examples/hello_world.c' contains a small "Hello World" Demo
4610 application; it is automatically compiled when you build U-Boot.
4611 It's configured to run at address 0x00040004, so you can play with it
4615 ## Ready for S-Record download ...
4616 ~>examples/hello_world.srec
4617 1 2 3 4 5 6 7 8 9 10 11 ...
4618 [file transfer complete]
4620 ## Start Addr = 0x00040004
4622 => go 40004 Hello World! This is a test.
4623 ## Starting application at 0x00040004 ...
4634 Hit any key to exit ...
4636 ## Application terminated, rc = 0x0
4638 Another example, which demonstrates how to register a CPM interrupt
4639 handler with the U-Boot code, can be found in 'examples/timer.c'.
4640 Here, a CPM timer is set up to generate an interrupt every second.
4641 The interrupt service routine is trivial, just printing a '.'
4642 character, but this is just a demo program. The application can be
4643 controlled by the following keys:
4645 ? - print current values og the CPM Timer registers
4646 b - enable interrupts and start timer
4647 e - stop timer and disable interrupts
4648 q - quit application
4651 ## Ready for S-Record download ...
4652 ~>examples/timer.srec
4653 1 2 3 4 5 6 7 8 9 10 11 ...
4654 [file transfer complete]
4656 ## Start Addr = 0x00040004
4659 ## Starting application at 0x00040004 ...
4662 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4665 [q, b, e, ?] Set interval 1000000 us
4668 [q, b, e, ?] ........
4669 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4672 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4675 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4678 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4680 [q, b, e, ?] ...Stopping timer
4682 [q, b, e, ?] ## Application terminated, rc = 0x0
4688 Over time, many people have reported problems when trying to use the
4689 "minicom" terminal emulation program for serial download. I (wd)
4690 consider minicom to be broken, and recommend not to use it. Under
4691 Unix, I recommend to use C-Kermit for general purpose use (and
4692 especially for kermit binary protocol download ("loadb" command), and
4693 use "cu" for S-Record download ("loads" command). See
4694 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4695 for help with kermit.
4698 Nevertheless, if you absolutely want to use it try adding this
4699 configuration to your "File transfer protocols" section:
4701 Name Program Name U/D FullScr IO-Red. Multi
4702 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4703 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4709 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4710 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4712 Building requires a cross environment; it is known to work on
4713 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4714 need gmake since the Makefiles are not compatible with BSD make).
4715 Note that the cross-powerpc package does not install include files;
4716 attempting to build U-Boot will fail because <machine/ansi.h> is
4717 missing. This file has to be installed and patched manually:
4719 # cd /usr/pkg/cross/powerpc-netbsd/include
4721 # ln -s powerpc machine
4722 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4723 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4725 Native builds *don't* work due to incompatibilities between native
4726 and U-Boot include files.
4728 Booting assumes that (the first part of) the image booted is a
4729 stage-2 loader which in turn loads and then invokes the kernel
4730 proper. Loader sources will eventually appear in the NetBSD source
4731 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4732 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4735 Implementation Internals:
4736 =========================
4738 The following is not intended to be a complete description of every
4739 implementation detail. However, it should help to understand the
4740 inner workings of U-Boot and make it easier to port it to custom
4744 Initial Stack, Global Data:
4745 ---------------------------
4747 The implementation of U-Boot is complicated by the fact that U-Boot
4748 starts running out of ROM (flash memory), usually without access to
4749 system RAM (because the memory controller is not initialized yet).
4750 This means that we don't have writable Data or BSS segments, and BSS
4751 is not initialized as zero. To be able to get a C environment working
4752 at all, we have to allocate at least a minimal stack. Implementation
4753 options for this are defined and restricted by the CPU used: Some CPU
4754 models provide on-chip memory (like the IMMR area on MPC8xx and
4755 MPC826x processors), on others (parts of) the data cache can be
4756 locked as (mis-) used as memory, etc.
4758 Chris Hallinan posted a good summary of these issues to the
4759 U-Boot mailing list:
4761 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4762 From: "Chris Hallinan" <clh@net1plus.com>
4763 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4766 Correct me if I'm wrong, folks, but the way I understand it
4767 is this: Using DCACHE as initial RAM for Stack, etc, does not
4768 require any physical RAM backing up the cache. The cleverness
4769 is that the cache is being used as a temporary supply of
4770 necessary storage before the SDRAM controller is setup. It's
4771 beyond the scope of this list to explain the details, but you
4772 can see how this works by studying the cache architecture and
4773 operation in the architecture and processor-specific manuals.
4775 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4776 is another option for the system designer to use as an
4777 initial stack/RAM area prior to SDRAM being available. Either
4778 option should work for you. Using CS 4 should be fine if your
4779 board designers haven't used it for something that would
4780 cause you grief during the initial boot! It is frequently not
4783 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4784 with your processor/board/system design. The default value
4785 you will find in any recent u-boot distribution in
4786 walnut.h should work for you. I'd set it to a value larger
4787 than your SDRAM module. If you have a 64MB SDRAM module, set
4788 it above 400_0000. Just make sure your board has no resources
4789 that are supposed to respond to that address! That code in
4790 start.S has been around a while and should work as is when
4791 you get the config right.
4796 It is essential to remember this, since it has some impact on the C
4797 code for the initialization procedures:
4799 * Initialized global data (data segment) is read-only. Do not attempt
4802 * Do not use any uninitialized global data (or implicitely initialized
4803 as zero data - BSS segment) at all - this is undefined, initiali-
4804 zation is performed later (when relocating to RAM).
4806 * Stack space is very limited. Avoid big data buffers or things like
4809 Having only the stack as writable memory limits means we cannot use
4810 normal global data to share information beween the code. But it
4811 turned out that the implementation of U-Boot can be greatly
4812 simplified by making a global data structure (gd_t) available to all
4813 functions. We could pass a pointer to this data as argument to _all_
4814 functions, but this would bloat the code. Instead we use a feature of
4815 the GCC compiler (Global Register Variables) to share the data: we
4816 place a pointer (gd) to the global data into a register which we
4817 reserve for this purpose.
4819 When choosing a register for such a purpose we are restricted by the
4820 relevant (E)ABI specifications for the current architecture, and by
4821 GCC's implementation.
4823 For PowerPC, the following registers have specific use:
4825 R2: reserved for system use
4826 R3-R4: parameter passing and return values
4827 R5-R10: parameter passing
4828 R13: small data area pointer
4832 (U-Boot also uses R12 as internal GOT pointer. r12
4833 is a volatile register so r12 needs to be reset when
4834 going back and forth between asm and C)
4836 ==> U-Boot will use R2 to hold a pointer to the global data
4838 Note: on PPC, we could use a static initializer (since the
4839 address of the global data structure is known at compile time),
4840 but it turned out that reserving a register results in somewhat
4841 smaller code - although the code savings are not that big (on
4842 average for all boards 752 bytes for the whole U-Boot image,
4843 624 text + 127 data).
4845 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4846 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4848 ==> U-Boot will use P3 to hold a pointer to the global data
4850 On ARM, the following registers are used:
4852 R0: function argument word/integer result
4853 R1-R3: function argument word
4855 R10: stack limit (used only if stack checking if enabled)
4856 R11: argument (frame) pointer
4857 R12: temporary workspace
4860 R15: program counter
4862 ==> U-Boot will use R8 to hold a pointer to the global data
4864 On Nios II, the ABI is documented here:
4865 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4867 ==> U-Boot will use gp to hold a pointer to the global data
4869 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4870 to access small data sections, so gp is free.
4872 On NDS32, the following registers are used:
4874 R0-R1: argument/return
4876 R15: temporary register for assembler
4877 R16: trampoline register
4878 R28: frame pointer (FP)
4879 R29: global pointer (GP)
4880 R30: link register (LP)
4881 R31: stack pointer (SP)
4882 PC: program counter (PC)
4884 ==> U-Boot will use R10 to hold a pointer to the global data
4886 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4887 or current versions of GCC may "optimize" the code too much.
4892 U-Boot runs in system state and uses physical addresses, i.e. the
4893 MMU is not used either for address mapping nor for memory protection.
4895 The available memory is mapped to fixed addresses using the memory
4896 controller. In this process, a contiguous block is formed for each
4897 memory type (Flash, SDRAM, SRAM), even when it consists of several
4898 physical memory banks.
4900 U-Boot is installed in the first 128 kB of the first Flash bank (on
4901 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4902 booting and sizing and initializing DRAM, the code relocates itself
4903 to the upper end of DRAM. Immediately below the U-Boot code some
4904 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4905 configuration setting]. Below that, a structure with global Board
4906 Info data is placed, followed by the stack (growing downward).
4908 Additionally, some exception handler code is copied to the low 8 kB
4909 of DRAM (0x00000000 ... 0x00001FFF).
4911 So a typical memory configuration with 16 MB of DRAM could look like
4914 0x0000 0000 Exception Vector code
4917 0x0000 2000 Free for Application Use
4923 0x00FB FF20 Monitor Stack (Growing downward)
4924 0x00FB FFAC Board Info Data and permanent copy of global data
4925 0x00FC 0000 Malloc Arena
4928 0x00FE 0000 RAM Copy of Monitor Code
4929 ... eventually: LCD or video framebuffer
4930 ... eventually: pRAM (Protected RAM - unchanged by reset)
4931 0x00FF FFFF [End of RAM]
4934 System Initialization:
4935 ----------------------
4937 In the reset configuration, U-Boot starts at the reset entry point
4938 (on most PowerPC systems at address 0x00000100). Because of the reset
4939 configuration for CS0# this is a mirror of the onboard Flash memory.
4940 To be able to re-map memory U-Boot then jumps to its link address.
4941 To be able to implement the initialization code in C, a (small!)
4942 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4943 which provide such a feature like MPC8xx or MPC8260), or in a locked
4944 part of the data cache. After that, U-Boot initializes the CPU core,
4945 the caches and the SIU.
4947 Next, all (potentially) available memory banks are mapped using a
4948 preliminary mapping. For example, we put them on 512 MB boundaries
4949 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4950 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4951 programmed for SDRAM access. Using the temporary configuration, a
4952 simple memory test is run that determines the size of the SDRAM
4955 When there is more than one SDRAM bank, and the banks are of
4956 different size, the largest is mapped first. For equal size, the first
4957 bank (CS2#) is mapped first. The first mapping is always for address
4958 0x00000000, with any additional banks following immediately to create
4959 contiguous memory starting from 0.
4961 Then, the monitor installs itself at the upper end of the SDRAM area
4962 and allocates memory for use by malloc() and for the global Board
4963 Info data; also, the exception vector code is copied to the low RAM
4964 pages, and the final stack is set up.
4966 Only after this relocation will you have a "normal" C environment;
4967 until that you are restricted in several ways, mostly because you are
4968 running from ROM, and because the code will have to be relocated to a
4972 U-Boot Porting Guide:
4973 ----------------------
4975 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4979 int main(int argc, char *argv[])
4981 sighandler_t no_more_time;
4983 signal(SIGALRM, no_more_time);
4984 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4986 if (available_money > available_manpower) {
4987 Pay consultant to port U-Boot;
4991 Download latest U-Boot source;
4993 Subscribe to u-boot mailing list;
4996 email("Hi, I am new to U-Boot, how do I get started?");
4999 Read the README file in the top level directory;
5000 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5001 Read applicable doc/*.README;
5002 Read the source, Luke;
5003 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5006 if (available_money > toLocalCurrency ($2500))
5009 Add a lot of aggravation and time;
5011 if (a similar board exists) { /* hopefully... */
5012 cp -a board/<similar> board/<myboard>
5013 cp include/configs/<similar>.h include/configs/<myboard>.h
5015 Create your own board support subdirectory;
5016 Create your own board include/configs/<myboard>.h file;
5018 Edit new board/<myboard> files
5019 Edit new include/configs/<myboard>.h
5024 Add / modify source code;
5028 email("Hi, I am having problems...");
5030 Send patch file to the U-Boot email list;
5031 if (reasonable critiques)
5032 Incorporate improvements from email list code review;
5034 Defend code as written;
5040 void no_more_time (int sig)
5049 All contributions to U-Boot should conform to the Linux kernel
5050 coding style; see the file "Documentation/CodingStyle" and the script
5051 "scripts/Lindent" in your Linux kernel source directory.
5053 Source files originating from a different project (for example the
5054 MTD subsystem) are generally exempt from these guidelines and are not
5055 reformated to ease subsequent migration to newer versions of those
5058 Please note that U-Boot is implemented in C (and to some small parts in
5059 Assembler); no C++ is used, so please do not use C++ style comments (//)
5062 Please also stick to the following formatting rules:
5063 - remove any trailing white space
5064 - use TAB characters for indentation and vertical alignment, not spaces
5065 - make sure NOT to use DOS '\r\n' line feeds
5066 - do not add more than 2 consecutive empty lines to source files
5067 - do not add trailing empty lines to source files
5069 Submissions which do not conform to the standards may be returned
5070 with a request to reformat the changes.
5076 Since the number of patches for U-Boot is growing, we need to
5077 establish some rules. Submissions which do not conform to these rules
5078 may be rejected, even when they contain important and valuable stuff.
5080 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5082 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5083 see http://lists.denx.de/mailman/listinfo/u-boot
5085 When you send a patch, please include the following information with
5088 * For bug fixes: a description of the bug and how your patch fixes
5089 this bug. Please try to include a way of demonstrating that the
5090 patch actually fixes something.
5092 * For new features: a description of the feature and your
5095 * A CHANGELOG entry as plaintext (separate from the patch)
5097 * For major contributions, your entry to the CREDITS file
5099 * When you add support for a new board, don't forget to add this
5100 board to the MAINTAINERS file, too.
5102 * If your patch adds new configuration options, don't forget to
5103 document these in the README file.
5105 * The patch itself. If you are using git (which is *strongly*
5106 recommended) you can easily generate the patch using the
5107 "git format-patch". If you then use "git send-email" to send it to
5108 the U-Boot mailing list, you will avoid most of the common problems
5109 with some other mail clients.
5111 If you cannot use git, use "diff -purN OLD NEW". If your version of
5112 diff does not support these options, then get the latest version of
5115 The current directory when running this command shall be the parent
5116 directory of the U-Boot source tree (i. e. please make sure that
5117 your patch includes sufficient directory information for the
5120 We prefer patches as plain text. MIME attachments are discouraged,
5121 and compressed attachments must not be used.
5123 * If one logical set of modifications affects or creates several
5124 files, all these changes shall be submitted in a SINGLE patch file.
5126 * Changesets that contain different, unrelated modifications shall be
5127 submitted as SEPARATE patches, one patch per changeset.
5132 * Before sending the patch, run the MAKEALL script on your patched
5133 source tree and make sure that no errors or warnings are reported
5134 for any of the boards.
5136 * Keep your modifications to the necessary minimum: A patch
5137 containing several unrelated changes or arbitrary reformats will be
5138 returned with a request to re-formatting / split it.
5140 * If you modify existing code, make sure that your new code does not
5141 add to the memory footprint of the code ;-) Small is beautiful!
5142 When adding new features, these should compile conditionally only
5143 (using #ifdef), and the resulting code with the new feature
5144 disabled must not need more memory than the old code without your
5147 * Remember that there is a size limit of 100 kB per message on the
5148 u-boot mailing list. Bigger patches will be moderated. If they are
5149 reasonable and not too big, they will be acknowledged. But patches
5150 bigger than the size limit should be avoided.