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.
708 See doc/README.autoboot for these options that
709 work with CONFIG_BOOTDELAY. None are required.
710 CONFIG_BOOT_RETRY_TIME
711 CONFIG_BOOT_RETRY_MIN
712 CONFIG_AUTOBOOT_KEYED
713 CONFIG_AUTOBOOT_PROMPT
714 CONFIG_AUTOBOOT_DELAY_STR
715 CONFIG_AUTOBOOT_STOP_STR
716 CONFIG_AUTOBOOT_DELAY_STR2
717 CONFIG_AUTOBOOT_STOP_STR2
718 CONFIG_ZERO_BOOTDELAY_CHECK
719 CONFIG_RESET_TO_RETRY
723 Only needed when CONFIG_BOOTDELAY is enabled;
724 define a command string that is automatically executed
725 when no character is read on the console interface
726 within "Boot Delay" after reset.
729 This can be used to pass arguments to the bootm
730 command. The value of CONFIG_BOOTARGS goes into the
731 environment value "bootargs".
733 CONFIG_RAMBOOT and CONFIG_NFSBOOT
734 The value of these goes into the environment as
735 "ramboot" and "nfsboot" respectively, and can be used
736 as a convenience, when switching between booting from
742 When this option is #defined, the existence of the
743 environment variable "preboot" will be checked
744 immediately before starting the CONFIG_BOOTDELAY
745 countdown and/or running the auto-boot command resp.
746 entering interactive mode.
748 This feature is especially useful when "preboot" is
749 automatically generated or modified. For an example
750 see the LWMON board specific code: here "preboot" is
751 modified when the user holds down a certain
752 combination of keys on the (special) keyboard when
755 - Serial Download Echo Mode:
757 If defined to 1, all characters received during a
758 serial download (using the "loads" command) are
759 echoed back. This might be needed by some terminal
760 emulations (like "cu"), but may as well just take
761 time on others. This setting #define's the initial
762 value of the "loads_echo" environment variable.
764 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
766 Select one of the baudrates listed in
767 CONFIG_SYS_BAUDRATE_TABLE, see below.
770 Monitor commands can be included or excluded
771 from the build by using the #include files
772 <config_cmd_all.h> and #undef'ing unwanted
773 commands, or using <config_cmd_default.h>
774 and augmenting with additional #define's
777 The default command configuration includes all commands
778 except those marked below with a "*".
780 CONFIG_CMD_ASKENV * ask for env variable
781 CONFIG_CMD_BDI bdinfo
782 CONFIG_CMD_BEDBUG * Include BedBug Debugger
783 CONFIG_CMD_BMP * BMP support
784 CONFIG_CMD_BSP * Board specific commands
785 CONFIG_CMD_BOOTD bootd
786 CONFIG_CMD_CACHE * icache, dcache
787 CONFIG_CMD_CONSOLE coninfo
788 CONFIG_CMD_CRC32 * crc32
789 CONFIG_CMD_DATE * support for RTC, date/time...
790 CONFIG_CMD_DHCP * DHCP support
791 CONFIG_CMD_DIAG * Diagnostics
792 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
793 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
794 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
795 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
796 CONFIG_CMD_DTT * Digital Therm and Thermostat
797 CONFIG_CMD_ECHO echo arguments
798 CONFIG_CMD_EDITENV edit env variable
799 CONFIG_CMD_EEPROM * EEPROM read/write support
800 CONFIG_CMD_ELF * bootelf, bootvx
801 CONFIG_CMD_EXPORTENV * export the environment
802 CONFIG_CMD_SAVEENV saveenv
803 CONFIG_CMD_FDC * Floppy Disk Support
804 CONFIG_CMD_FAT * FAT partition support
805 CONFIG_CMD_FDOS * Dos diskette Support
806 CONFIG_CMD_FLASH flinfo, erase, protect
807 CONFIG_CMD_FPGA FPGA device initialization support
808 CONFIG_CMD_GO * the 'go' command (exec code)
809 CONFIG_CMD_GREPENV * search environment
810 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
811 CONFIG_CMD_I2C * I2C serial bus support
812 CONFIG_CMD_IDE * IDE harddisk support
813 CONFIG_CMD_IMI iminfo
814 CONFIG_CMD_IMLS List all found images
815 CONFIG_CMD_IMMAP * IMMR dump support
816 CONFIG_CMD_IMPORTENV * import an environment
817 CONFIG_CMD_IRQ * irqinfo
818 CONFIG_CMD_ITEST Integer/string test of 2 values
819 CONFIG_CMD_JFFS2 * JFFS2 Support
820 CONFIG_CMD_KGDB * kgdb
821 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
822 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
824 CONFIG_CMD_LOADB loadb
825 CONFIG_CMD_LOADS loads
826 CONFIG_CMD_MD5SUM print md5 message digest
827 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
828 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
830 CONFIG_CMD_MISC Misc functions like sleep etc
831 CONFIG_CMD_MMC * MMC memory mapped support
832 CONFIG_CMD_MII * MII utility commands
833 CONFIG_CMD_MTDPARTS * MTD partition support
834 CONFIG_CMD_NAND * NAND support
835 CONFIG_CMD_NET bootp, tftpboot, rarpboot
836 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
837 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
838 CONFIG_CMD_PCI * pciinfo
839 CONFIG_CMD_PCMCIA * PCMCIA support
840 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
842 CONFIG_CMD_PORTIO * Port I/O
843 CONFIG_CMD_REGINFO * Register dump
844 CONFIG_CMD_RUN run command in env variable
845 CONFIG_CMD_SAVES * save S record dump
846 CONFIG_CMD_SCSI * SCSI Support
847 CONFIG_CMD_SDRAM * print SDRAM configuration information
848 (requires CONFIG_CMD_I2C)
849 CONFIG_CMD_SETGETDCR Support for DCR Register access
851 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
852 CONFIG_CMD_SHA1SUM print sha1 memory digest
853 (requires CONFIG_CMD_MEMORY)
854 CONFIG_CMD_SOURCE "source" command Support
855 CONFIG_CMD_SPI * SPI serial bus support
856 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
857 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
858 CONFIG_CMD_TIME * run command and report execution time
859 CONFIG_CMD_USB * USB support
860 CONFIG_CMD_CDP * Cisco Discover Protocol support
861 CONFIG_CMD_MFSL * Microblaze FSL support
864 EXAMPLE: If you want all functions except of network
865 support you can write:
867 #include "config_cmd_all.h"
868 #undef CONFIG_CMD_NET
871 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
873 Note: Don't enable the "icache" and "dcache" commands
874 (configuration option CONFIG_CMD_CACHE) unless you know
875 what you (and your U-Boot users) are doing. Data
876 cache cannot be enabled on systems like the 8xx or
877 8260 (where accesses to the IMMR region must be
878 uncached), and it cannot be disabled on all other
879 systems where we (mis-) use the data cache to hold an
880 initial stack and some data.
883 XXX - this list needs to get updated!
887 If this variable is defined, U-Boot will use a device tree
888 to configure its devices, instead of relying on statically
889 compiled #defines in the board file. This option is
890 experimental and only available on a few boards. The device
891 tree is available in the global data as gd->fdt_blob.
893 U-Boot needs to get its device tree from somewhere. This can
894 be done using one of the two options below:
897 If this variable is defined, U-Boot will embed a device tree
898 binary in its image. This device tree file should be in the
899 board directory and called <soc>-<board>.dts. The binary file
900 is then picked up in board_init_f() and made available through
901 the global data structure as gd->blob.
904 If this variable is defined, U-Boot will build a device tree
905 binary. It will be called u-boot.dtb. Architecture-specific
906 code will locate it at run-time. Generally this works by:
908 cat u-boot.bin u-boot.dtb >image.bin
910 and in fact, U-Boot does this for you, creating a file called
911 u-boot-dtb.bin which is useful in the common case. You can
912 still use the individual files if you need something more
917 If this variable is defined, it enables watchdog
918 support for the SoC. There must be support in the SoC
919 specific code for a watchdog. For the 8xx and 8260
920 CPUs, the SIU Watchdog feature is enabled in the SYPCR
921 register. When supported for a specific SoC is
922 available, then no further board specific code should
926 When using a watchdog circuitry external to the used
927 SoC, then define this variable and provide board
928 specific code for the "hw_watchdog_reset" function.
931 CONFIG_VERSION_VARIABLE
932 If this variable is defined, an environment variable
933 named "ver" is created by U-Boot showing the U-Boot
934 version as printed by the "version" command.
935 Any change to this variable will be reverted at the
940 When CONFIG_CMD_DATE is selected, the type of the RTC
941 has to be selected, too. Define exactly one of the
944 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
945 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
946 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
947 CONFIG_RTC_MC146818 - use MC146818 RTC
948 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
949 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
950 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
951 CONFIG_RTC_DS164x - use Dallas DS164x RTC
952 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
953 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
954 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
955 CONFIG_SYS_RV3029_TCR - enable trickle charger on
958 Note that if the RTC uses I2C, then the I2C interface
959 must also be configured. See I2C Support, below.
962 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
963 CONFIG_PCA953X_INFO - enable pca953x info command
965 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
966 chip-ngpio pairs that tell the PCA953X driver the number of
967 pins supported by a particular chip.
969 Note that if the GPIO device uses I2C, then the I2C interface
970 must also be configured. See I2C Support, below.
974 When CONFIG_TIMESTAMP is selected, the timestamp
975 (date and time) of an image is printed by image
976 commands like bootm or iminfo. This option is
977 automatically enabled when you select CONFIG_CMD_DATE .
979 - Partition Labels (disklabels) Supported:
980 Zero or more of the following:
981 CONFIG_MAC_PARTITION Apple's MacOS partition table.
982 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
983 Intel architecture, USB sticks, etc.
984 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
985 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
986 bootloader. Note 2TB partition limit; see
988 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
990 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
991 CONFIG_CMD_SCSI) you must configure support for at
992 least one non-MTD partition type as well.
995 CONFIG_IDE_RESET_ROUTINE - this is defined in several
996 board configurations files but used nowhere!
998 CONFIG_IDE_RESET - is this is defined, IDE Reset will
999 be performed by calling the function
1000 ide_set_reset(int reset)
1001 which has to be defined in a board specific file
1006 Set this to enable ATAPI support.
1011 Set this to enable support for disks larger than 137GB
1012 Also look at CONFIG_SYS_64BIT_LBA.
1013 Whithout these , LBA48 support uses 32bit variables and will 'only'
1014 support disks up to 2.1TB.
1016 CONFIG_SYS_64BIT_LBA:
1017 When enabled, makes the IDE subsystem use 64bit sector addresses.
1021 At the moment only there is only support for the
1022 SYM53C8XX SCSI controller; define
1023 CONFIG_SCSI_SYM53C8XX to enable it.
1025 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1026 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1027 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1028 maximum numbers of LUNs, SCSI ID's and target
1030 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1032 - NETWORK Support (PCI):
1034 Support for Intel 8254x/8257x gigabit chips.
1037 Utility code for direct access to the SPI bus on Intel 8257x.
1038 This does not do anything useful unless you set at least one
1039 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1041 CONFIG_E1000_SPI_GENERIC
1042 Allow generic access to the SPI bus on the Intel 8257x, for
1043 example with the "sspi" command.
1046 Management command for E1000 devices. When used on devices
1047 with SPI support you can reprogram the EEPROM from U-Boot.
1049 CONFIG_E1000_FALLBACK_MAC
1050 default MAC for empty EEPROM after production.
1053 Support for Intel 82557/82559/82559ER chips.
1054 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1055 write routine for first time initialisation.
1058 Support for Digital 2114x chips.
1059 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1060 modem chip initialisation (KS8761/QS6611).
1063 Support for National dp83815 chips.
1066 Support for National dp8382[01] gigabit chips.
1068 - NETWORK Support (other):
1070 CONFIG_DRIVER_AT91EMAC
1071 Support for AT91RM9200 EMAC.
1074 Define this to use reduced MII inteface
1076 CONFIG_DRIVER_AT91EMAC_QUIET
1077 If this defined, the driver is quiet.
1078 The driver doen't show link status messages.
1080 CONFIG_CALXEDA_XGMAC
1081 Support for the Calxeda XGMAC device
1083 CONFIG_DRIVER_LAN91C96
1084 Support for SMSC's LAN91C96 chips.
1086 CONFIG_LAN91C96_BASE
1087 Define this to hold the physical address
1088 of the LAN91C96's I/O space
1090 CONFIG_LAN91C96_USE_32_BIT
1091 Define this to enable 32 bit addressing
1093 CONFIG_DRIVER_SMC91111
1094 Support for SMSC's LAN91C111 chip
1096 CONFIG_SMC91111_BASE
1097 Define this to hold the physical address
1098 of the device (I/O space)
1100 CONFIG_SMC_USE_32_BIT
1101 Define this if data bus is 32 bits
1103 CONFIG_SMC_USE_IOFUNCS
1104 Define this to use i/o functions instead of macros
1105 (some hardware wont work with macros)
1107 CONFIG_DRIVER_TI_EMAC
1108 Support for davinci emac
1110 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1111 Define this if you have more then 3 PHYs.
1114 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1116 CONFIG_FTGMAC100_EGIGA
1117 Define this to use GE link update with gigabit PHY.
1118 Define this if FTGMAC100 is connected to gigabit PHY.
1119 If your system has 10/100 PHY only, it might not occur
1120 wrong behavior. Because PHY usually return timeout or
1121 useless data when polling gigabit status and gigabit
1122 control registers. This behavior won't affect the
1123 correctnessof 10/100 link speed update.
1126 Support for SMSC's LAN911x and LAN921x chips
1129 Define this to hold the physical address
1130 of the device (I/O space)
1132 CONFIG_SMC911X_32_BIT
1133 Define this if data bus is 32 bits
1135 CONFIG_SMC911X_16_BIT
1136 Define this if data bus is 16 bits. If your processor
1137 automatically converts one 32 bit word to two 16 bit
1138 words you may also try CONFIG_SMC911X_32_BIT.
1141 Support for Renesas on-chip Ethernet controller
1143 CONFIG_SH_ETHER_USE_PORT
1144 Define the number of ports to be used
1146 CONFIG_SH_ETHER_PHY_ADDR
1147 Define the ETH PHY's address
1149 CONFIG_SH_ETHER_CACHE_WRITEBACK
1150 If this option is set, the driver enables cache flush.
1153 CONFIG_GENERIC_LPC_TPM
1154 Support for generic parallel port TPM devices. Only one device
1155 per system is supported at this time.
1157 CONFIG_TPM_TIS_BASE_ADDRESS
1158 Base address where the generic TPM device is mapped
1159 to. Contemporary x86 systems usually map it at
1163 At the moment only the UHCI host controller is
1164 supported (PIP405, MIP405, MPC5200); define
1165 CONFIG_USB_UHCI to enable it.
1166 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1167 and define CONFIG_USB_STORAGE to enable the USB
1170 Supported are USB Keyboards and USB Floppy drives
1172 MPC5200 USB requires additional defines:
1174 for 528 MHz Clock: 0x0001bbbb
1178 for differential drivers: 0x00001000
1179 for single ended drivers: 0x00005000
1180 for differential drivers on PSC3: 0x00000100
1181 for single ended drivers on PSC3: 0x00004100
1182 CONFIG_SYS_USB_EVENT_POLL
1183 May be defined to allow interrupt polling
1184 instead of using asynchronous interrupts
1186 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1187 txfilltuning field in the EHCI controller on reset.
1190 Define the below if you wish to use the USB console.
1191 Once firmware is rebuilt from a serial console issue the
1192 command "setenv stdin usbtty; setenv stdout usbtty" and
1193 attach your USB cable. The Unix command "dmesg" should print
1194 it has found a new device. The environment variable usbtty
1195 can be set to gserial or cdc_acm to enable your device to
1196 appear to a USB host as a Linux gserial device or a
1197 Common Device Class Abstract Control Model serial device.
1198 If you select usbtty = gserial you should be able to enumerate
1200 # modprobe usbserial vendor=0xVendorID product=0xProductID
1201 else if using cdc_acm, simply setting the environment
1202 variable usbtty to be cdc_acm should suffice. The following
1203 might be defined in YourBoardName.h
1206 Define this to build a UDC device
1209 Define this to have a tty type of device available to
1210 talk to the UDC device
1213 Define this to enable the high speed support for usb
1214 device and usbtty. If this feature is enabled, a routine
1215 int is_usbd_high_speed(void)
1216 also needs to be defined by the driver to dynamically poll
1217 whether the enumeration has succeded at high speed or full
1220 CONFIG_SYS_CONSOLE_IS_IN_ENV
1221 Define this if you want stdin, stdout &/or stderr to
1225 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1226 Derive USB clock from external clock "blah"
1227 - CONFIG_SYS_USB_EXTC_CLK 0x02
1229 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1230 Derive USB clock from brgclk
1231 - CONFIG_SYS_USB_BRG_CLK 0x04
1233 If you have a USB-IF assigned VendorID then you may wish to
1234 define your own vendor specific values either in BoardName.h
1235 or directly in usbd_vendor_info.h. If you don't define
1236 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1237 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1238 should pretend to be a Linux device to it's target host.
1240 CONFIG_USBD_MANUFACTURER
1241 Define this string as the name of your company for
1242 - CONFIG_USBD_MANUFACTURER "my company"
1244 CONFIG_USBD_PRODUCT_NAME
1245 Define this string as the name of your product
1246 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1248 CONFIG_USBD_VENDORID
1249 Define this as your assigned Vendor ID from the USB
1250 Implementors Forum. This *must* be a genuine Vendor ID
1251 to avoid polluting the USB namespace.
1252 - CONFIG_USBD_VENDORID 0xFFFF
1254 CONFIG_USBD_PRODUCTID
1255 Define this as the unique Product ID
1257 - CONFIG_USBD_PRODUCTID 0xFFFF
1259 - ULPI Layer Support:
1260 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1261 the generic ULPI layer. The generic layer accesses the ULPI PHY
1262 via the platform viewport, so you need both the genric layer and
1263 the viewport enabled. Currently only Chipidea/ARC based
1264 viewport is supported.
1265 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1266 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1269 The MMC controller on the Intel PXA is supported. To
1270 enable this define CONFIG_MMC. The MMC can be
1271 accessed from the boot prompt by mapping the device
1272 to physical memory similar to flash. Command line is
1273 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1274 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1277 Support for Renesas on-chip MMCIF controller
1279 CONFIG_SH_MMCIF_ADDR
1280 Define the base address of MMCIF registers
1283 Define the clock frequency for MMCIF
1285 - Journaling Flash filesystem support:
1286 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1287 CONFIG_JFFS2_NAND_DEV
1288 Define these for a default partition on a NAND device
1290 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1291 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1292 Define these for a default partition on a NOR device
1294 CONFIG_SYS_JFFS_CUSTOM_PART
1295 Define this to create an own partition. You have to provide a
1296 function struct part_info* jffs2_part_info(int part_num)
1298 If you define only one JFFS2 partition you may also want to
1299 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1300 to disable the command chpart. This is the default when you
1301 have not defined a custom partition
1303 - FAT(File Allocation Table) filesystem write function support:
1306 Define this to enable support for saving memory data as a
1307 file in FAT formatted partition.
1309 This will also enable the command "fatwrite" enabling the
1310 user to write files to FAT.
1315 Define this to enable standard (PC-Style) keyboard
1319 Standard PC keyboard driver with US (is default) and
1320 GERMAN key layout (switch via environment 'keymap=de') support.
1321 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1322 for cfb_console. Supports cursor blinking.
1327 Define this to enable video support (for output to
1330 CONFIG_VIDEO_CT69000
1332 Enable Chips & Technologies 69000 Video chip
1334 CONFIG_VIDEO_SMI_LYNXEM
1335 Enable Silicon Motion SMI 712/710/810 Video chip. The
1336 video output is selected via environment 'videoout'
1337 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1340 For the CT69000 and SMI_LYNXEM drivers, videomode is
1341 selected via environment 'videomode'. Two different ways
1343 - "videomode=num" 'num' is a standard LiLo mode numbers.
1344 Following standard modes are supported (* is default):
1346 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1347 -------------+---------------------------------------------
1348 8 bits | 0x301* 0x303 0x305 0x161 0x307
1349 15 bits | 0x310 0x313 0x316 0x162 0x319
1350 16 bits | 0x311 0x314 0x317 0x163 0x31A
1351 24 bits | 0x312 0x315 0x318 ? 0x31B
1352 -------------+---------------------------------------------
1353 (i.e. setenv videomode 317; saveenv; reset;)
1355 - "videomode=bootargs" all the video parameters are parsed
1356 from the bootargs. (See drivers/video/videomodes.c)
1359 CONFIG_VIDEO_SED13806
1360 Enable Epson SED13806 driver. This driver supports 8bpp
1361 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1362 or CONFIG_VIDEO_SED13806_16BPP
1365 Enable the Freescale DIU video driver. Reference boards for
1366 SOCs that have a DIU should define this macro to enable DIU
1367 support, and should also define these other macros:
1373 CONFIG_VIDEO_SW_CURSOR
1374 CONFIG_VGA_AS_SINGLE_DEVICE
1376 CONFIG_VIDEO_BMP_LOGO
1378 The DIU driver will look for the 'video-mode' environment
1379 variable, and if defined, enable the DIU as a console during
1380 boot. See the documentation file README.video for a
1381 description of this variable.
1386 Define this to enable a custom keyboard support.
1387 This simply calls drv_keyboard_init() which must be
1388 defined in your board-specific files.
1389 The only board using this so far is RBC823.
1391 - LCD Support: CONFIG_LCD
1393 Define this to enable LCD support (for output to LCD
1394 display); also select one of the supported displays
1395 by defining one of these:
1399 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1401 CONFIG_NEC_NL6448AC33:
1403 NEC NL6448AC33-18. Active, color, single scan.
1405 CONFIG_NEC_NL6448BC20
1407 NEC NL6448BC20-08. 6.5", 640x480.
1408 Active, color, single scan.
1410 CONFIG_NEC_NL6448BC33_54
1412 NEC NL6448BC33-54. 10.4", 640x480.
1413 Active, color, single scan.
1417 Sharp 320x240. Active, color, single scan.
1418 It isn't 16x9, and I am not sure what it is.
1420 CONFIG_SHARP_LQ64D341
1422 Sharp LQ64D341 display, 640x480.
1423 Active, color, single scan.
1427 HLD1045 display, 640x480.
1428 Active, color, single scan.
1432 Optrex CBL50840-2 NF-FW 99 22 M5
1434 Hitachi LMG6912RPFC-00T
1438 320x240. Black & white.
1440 Normally display is black on white background; define
1441 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1443 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1445 If this option is set, the environment is checked for
1446 a variable "splashimage". If found, the usual display
1447 of logo, copyright and system information on the LCD
1448 is suppressed and the BMP image at the address
1449 specified in "splashimage" is loaded instead. The
1450 console is redirected to the "nulldev", too. This
1451 allows for a "silent" boot where a splash screen is
1452 loaded very quickly after power-on.
1454 CONFIG_SPLASH_SCREEN_ALIGN
1456 If this option is set the splash image can be freely positioned
1457 on the screen. Environment variable "splashpos" specifies the
1458 position as "x,y". If a positive number is given it is used as
1459 number of pixel from left/top. If a negative number is given it
1460 is used as number of pixel from right/bottom. You can also
1461 specify 'm' for centering the image.
1464 setenv splashpos m,m
1465 => image at center of screen
1467 setenv splashpos 30,20
1468 => image at x = 30 and y = 20
1470 setenv splashpos -10,m
1471 => vertically centered image
1472 at x = dspWidth - bmpWidth - 9
1474 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1476 If this option is set, additionally to standard BMP
1477 images, gzipped BMP images can be displayed via the
1478 splashscreen support or the bmp command.
1480 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1482 If this option is set, 8-bit RLE compressed BMP images
1483 can be displayed via the splashscreen support or the
1486 - Compression support:
1489 If this option is set, support for bzip2 compressed
1490 images is included. If not, only uncompressed and gzip
1491 compressed images are supported.
1493 NOTE: the bzip2 algorithm requires a lot of RAM, so
1494 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1499 If this option is set, support for lzma compressed
1502 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1503 requires an amount of dynamic memory that is given by the
1506 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1508 Where lc and lp stand for, respectively, Literal context bits
1509 and Literal pos bits.
1511 This value is upper-bounded by 14MB in the worst case. Anyway,
1512 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1513 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1514 a very small buffer.
1516 Use the lzmainfo tool to determinate the lc and lp values and
1517 then calculate the amount of needed dynamic memory (ensuring
1518 the appropriate CONFIG_SYS_MALLOC_LEN value).
1523 The address of PHY on MII bus.
1525 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1527 The clock frequency of the MII bus
1531 If this option is set, support for speed/duplex
1532 detection of gigabit PHY is included.
1534 CONFIG_PHY_RESET_DELAY
1536 Some PHY like Intel LXT971A need extra delay after
1537 reset before any MII register access is possible.
1538 For such PHY, set this option to the usec delay
1539 required. (minimum 300usec for LXT971A)
1541 CONFIG_PHY_CMD_DELAY (ppc4xx)
1543 Some PHY like Intel LXT971A need extra delay after
1544 command issued before MII status register can be read
1554 Define a default value for Ethernet address to use
1555 for the respective Ethernet interface, in case this
1556 is not determined automatically.
1561 Define a default value for the IP address to use for
1562 the default Ethernet interface, in case this is not
1563 determined through e.g. bootp.
1564 (Environment variable "ipaddr")
1566 - Server IP address:
1569 Defines a default value for the IP address of a TFTP
1570 server to contact when using the "tftboot" command.
1571 (Environment variable "serverip")
1573 CONFIG_KEEP_SERVERADDR
1575 Keeps the server's MAC address, in the env 'serveraddr'
1576 for passing to bootargs (like Linux's netconsole option)
1578 - Gateway IP address:
1581 Defines a default value for the IP address of the
1582 default router where packets to other networks are
1584 (Environment variable "gatewayip")
1589 Defines a default value for the subnet mask (or
1590 routing prefix) which is used to determine if an IP
1591 address belongs to the local subnet or needs to be
1592 forwarded through a router.
1593 (Environment variable "netmask")
1595 - Multicast TFTP Mode:
1598 Defines whether you want to support multicast TFTP as per
1599 rfc-2090; for example to work with atftp. Lets lots of targets
1600 tftp down the same boot image concurrently. Note: the Ethernet
1601 driver in use must provide a function: mcast() to join/leave a
1604 - BOOTP Recovery Mode:
1605 CONFIG_BOOTP_RANDOM_DELAY
1607 If you have many targets in a network that try to
1608 boot using BOOTP, you may want to avoid that all
1609 systems send out BOOTP requests at precisely the same
1610 moment (which would happen for instance at recovery
1611 from a power failure, when all systems will try to
1612 boot, thus flooding the BOOTP server. Defining
1613 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1614 inserted before sending out BOOTP requests. The
1615 following delays are inserted then:
1617 1st BOOTP request: delay 0 ... 1 sec
1618 2nd BOOTP request: delay 0 ... 2 sec
1619 3rd BOOTP request: delay 0 ... 4 sec
1621 BOOTP requests: delay 0 ... 8 sec
1623 - DHCP Advanced Options:
1624 You can fine tune the DHCP functionality by defining
1625 CONFIG_BOOTP_* symbols:
1627 CONFIG_BOOTP_SUBNETMASK
1628 CONFIG_BOOTP_GATEWAY
1629 CONFIG_BOOTP_HOSTNAME
1630 CONFIG_BOOTP_NISDOMAIN
1631 CONFIG_BOOTP_BOOTPATH
1632 CONFIG_BOOTP_BOOTFILESIZE
1635 CONFIG_BOOTP_SEND_HOSTNAME
1636 CONFIG_BOOTP_NTPSERVER
1637 CONFIG_BOOTP_TIMEOFFSET
1638 CONFIG_BOOTP_VENDOREX
1639 CONFIG_BOOTP_MAY_FAIL
1641 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1642 environment variable, not the BOOTP server.
1644 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1645 after the configured retry count, the call will fail
1646 instead of starting over. This can be used to fail over
1647 to Link-local IP address configuration if the DHCP server
1650 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1651 serverip from a DHCP server, it is possible that more
1652 than one DNS serverip is offered to the client.
1653 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1654 serverip will be stored in the additional environment
1655 variable "dnsip2". The first DNS serverip is always
1656 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1659 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1660 to do a dynamic update of a DNS server. To do this, they
1661 need the hostname of the DHCP requester.
1662 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1663 of the "hostname" environment variable is passed as
1664 option 12 to the DHCP server.
1666 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1668 A 32bit value in microseconds for a delay between
1669 receiving a "DHCP Offer" and sending the "DHCP Request".
1670 This fixes a problem with certain DHCP servers that don't
1671 respond 100% of the time to a "DHCP request". E.g. On an
1672 AT91RM9200 processor running at 180MHz, this delay needed
1673 to be *at least* 15,000 usec before a Windows Server 2003
1674 DHCP server would reply 100% of the time. I recommend at
1675 least 50,000 usec to be safe. The alternative is to hope
1676 that one of the retries will be successful but note that
1677 the DHCP timeout and retry process takes a longer than
1680 - Link-local IP address negotiation:
1681 Negotiate with other link-local clients on the local network
1682 for an address that doesn't require explicit configuration.
1683 This is especially useful if a DHCP server cannot be guaranteed
1684 to exist in all environments that the device must operate.
1686 See doc/README.link-local for more information.
1689 CONFIG_CDP_DEVICE_ID
1691 The device id used in CDP trigger frames.
1693 CONFIG_CDP_DEVICE_ID_PREFIX
1695 A two character string which is prefixed to the MAC address
1700 A printf format string which contains the ascii name of
1701 the port. Normally is set to "eth%d" which sets
1702 eth0 for the first Ethernet, eth1 for the second etc.
1704 CONFIG_CDP_CAPABILITIES
1706 A 32bit integer which indicates the device capabilities;
1707 0x00000010 for a normal host which does not forwards.
1711 An ascii string containing the version of the software.
1715 An ascii string containing the name of the platform.
1719 A 32bit integer sent on the trigger.
1721 CONFIG_CDP_POWER_CONSUMPTION
1723 A 16bit integer containing the power consumption of the
1724 device in .1 of milliwatts.
1726 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1728 A byte containing the id of the VLAN.
1730 - Status LED: CONFIG_STATUS_LED
1732 Several configurations allow to display the current
1733 status using a LED. For instance, the LED will blink
1734 fast while running U-Boot code, stop blinking as
1735 soon as a reply to a BOOTP request was received, and
1736 start blinking slow once the Linux kernel is running
1737 (supported by a status LED driver in the Linux
1738 kernel). Defining CONFIG_STATUS_LED enables this
1741 - CAN Support: CONFIG_CAN_DRIVER
1743 Defining CONFIG_CAN_DRIVER enables CAN driver support
1744 on those systems that support this (optional)
1745 feature, like the TQM8xxL modules.
1747 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1749 These enable I2C serial bus commands. Defining either of
1750 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1751 include the appropriate I2C driver for the selected CPU.
1753 This will allow you to use i2c commands at the u-boot
1754 command line (as long as you set CONFIG_CMD_I2C in
1755 CONFIG_COMMANDS) and communicate with i2c based realtime
1756 clock chips. See common/cmd_i2c.c for a description of the
1757 command line interface.
1759 CONFIG_HARD_I2C selects a hardware I2C controller.
1761 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1762 bit-banging) driver instead of CPM or similar hardware
1765 There are several other quantities that must also be
1766 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1768 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1769 to be the frequency (in Hz) at which you wish your i2c bus
1770 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1771 the CPU's i2c node address).
1773 Now, the u-boot i2c code for the mpc8xx
1774 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1775 and so its address should therefore be cleared to 0 (See,
1776 eg, MPC823e User's Manual p.16-473). So, set
1777 CONFIG_SYS_I2C_SLAVE to 0.
1779 CONFIG_SYS_I2C_INIT_MPC5XXX
1781 When a board is reset during an i2c bus transfer
1782 chips might think that the current transfer is still
1783 in progress. Reset the slave devices by sending start
1784 commands until the slave device responds.
1786 That's all that's required for CONFIG_HARD_I2C.
1788 If you use the software i2c interface (CONFIG_SOFT_I2C)
1789 then the following macros need to be defined (examples are
1790 from include/configs/lwmon.h):
1794 (Optional). Any commands necessary to enable the I2C
1795 controller or configure ports.
1797 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1801 (Only for MPC8260 CPU). The I/O port to use (the code
1802 assumes both bits are on the same port). Valid values
1803 are 0..3 for ports A..D.
1807 The code necessary to make the I2C data line active
1808 (driven). If the data line is open collector, this
1811 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1815 The code necessary to make the I2C data line tri-stated
1816 (inactive). If the data line is open collector, this
1819 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1823 Code that returns TRUE if the I2C data line is high,
1826 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1830 If <bit> is TRUE, sets the I2C data line high. If it
1831 is FALSE, it clears it (low).
1833 eg: #define I2C_SDA(bit) \
1834 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1835 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1839 If <bit> is TRUE, sets the I2C clock line high. If it
1840 is FALSE, it clears it (low).
1842 eg: #define I2C_SCL(bit) \
1843 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1844 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1848 This delay is invoked four times per clock cycle so this
1849 controls the rate of data transfer. The data rate thus
1850 is 1 / (I2C_DELAY * 4). Often defined to be something
1853 #define I2C_DELAY udelay(2)
1855 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1857 If your arch supports the generic GPIO framework (asm/gpio.h),
1858 then you may alternatively define the two GPIOs that are to be
1859 used as SCL / SDA. Any of the previous I2C_xxx macros will
1860 have GPIO-based defaults assigned to them as appropriate.
1862 You should define these to the GPIO value as given directly to
1863 the generic GPIO functions.
1865 CONFIG_SYS_I2C_INIT_BOARD
1867 When a board is reset during an i2c bus transfer
1868 chips might think that the current transfer is still
1869 in progress. On some boards it is possible to access
1870 the i2c SCLK line directly, either by using the
1871 processor pin as a GPIO or by having a second pin
1872 connected to the bus. If this option is defined a
1873 custom i2c_init_board() routine in boards/xxx/board.c
1874 is run early in the boot sequence.
1876 CONFIG_SYS_I2C_BOARD_LATE_INIT
1878 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1879 defined a custom i2c_board_late_init() routine in
1880 boards/xxx/board.c is run AFTER the operations in i2c_init()
1881 is completed. This callpoint can be used to unreset i2c bus
1882 using CPU i2c controller register accesses for CPUs whose i2c
1883 controller provide such a method. It is called at the end of
1884 i2c_init() to allow i2c_init operations to setup the i2c bus
1885 controller on the CPU (e.g. setting bus speed & slave address).
1887 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1889 This option enables configuration of bi_iic_fast[] flags
1890 in u-boot bd_info structure based on u-boot environment
1891 variable "i2cfast". (see also i2cfast)
1893 CONFIG_I2C_MULTI_BUS
1895 This option allows the use of multiple I2C buses, each of which
1896 must have a controller. At any point in time, only one bus is
1897 active. To switch to a different bus, use the 'i2c dev' command.
1898 Note that bus numbering is zero-based.
1900 CONFIG_SYS_I2C_NOPROBES
1902 This option specifies a list of I2C devices that will be skipped
1903 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1904 is set, specify a list of bus-device pairs. Otherwise, specify
1905 a 1D array of device addresses
1908 #undef CONFIG_I2C_MULTI_BUS
1909 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1911 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1913 #define CONFIG_I2C_MULTI_BUS
1914 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1916 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1918 CONFIG_SYS_SPD_BUS_NUM
1920 If defined, then this indicates the I2C bus number for DDR SPD.
1921 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1923 CONFIG_SYS_RTC_BUS_NUM
1925 If defined, then this indicates the I2C bus number for the RTC.
1926 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1928 CONFIG_SYS_DTT_BUS_NUM
1930 If defined, then this indicates the I2C bus number for the DTT.
1931 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1933 CONFIG_SYS_I2C_DTT_ADDR:
1935 If defined, specifies the I2C address of the DTT device.
1936 If not defined, then U-Boot uses predefined value for
1937 specified DTT device.
1941 Define this option if you want to use Freescale's I2C driver in
1942 drivers/i2c/fsl_i2c.c.
1946 Define this option if you have I2C devices reached over 1 .. n
1947 I2C Muxes like the pca9544a. This option addes a new I2C
1948 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1949 new I2C Bus to the existing I2C Busses. If you select the
1950 new Bus with "i2c dev", u-bbot sends first the commandos for
1951 the muxes to activate this new "bus".
1953 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1957 Adding a new I2C Bus reached over 2 pca9544a muxes
1958 The First mux with address 70 and channel 6
1959 The Second mux with address 71 and channel 4
1961 => i2c bus pca9544a:70:6:pca9544a:71:4
1963 Use the "i2c bus" command without parameter, to get a list
1964 of I2C Busses with muxes:
1967 Busses reached over muxes:
1969 reached over Mux(es):
1972 reached over Mux(es):
1977 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1978 u-boot first sends the command to the mux@70 to enable
1979 channel 6, and then the command to the mux@71 to enable
1982 After that, you can use the "normal" i2c commands as
1983 usual to communicate with your I2C devices behind
1986 This option is actually implemented for the bitbanging
1987 algorithm in common/soft_i2c.c and for the Hardware I2C
1988 Bus on the MPC8260. But it should be not so difficult
1989 to add this option to other architectures.
1991 CONFIG_SOFT_I2C_READ_REPEATED_START
1993 defining this will force the i2c_read() function in
1994 the soft_i2c driver to perform an I2C repeated start
1995 between writing the address pointer and reading the
1996 data. If this define is omitted the default behaviour
1997 of doing a stop-start sequence will be used. Most I2C
1998 devices can use either method, but some require one or
2001 - SPI Support: CONFIG_SPI
2003 Enables SPI driver (so far only tested with
2004 SPI EEPROM, also an instance works with Crystal A/D and
2005 D/As on the SACSng board)
2009 Enables the driver for SPI controller on SuperH. Currently
2010 only SH7757 is supported.
2014 Enables extended (16-bit) SPI EEPROM addressing.
2015 (symmetrical to CONFIG_I2C_X)
2019 Enables a software (bit-bang) SPI driver rather than
2020 using hardware support. This is a general purpose
2021 driver that only requires three general I/O port pins
2022 (two outputs, one input) to function. If this is
2023 defined, the board configuration must define several
2024 SPI configuration items (port pins to use, etc). For
2025 an example, see include/configs/sacsng.h.
2029 Enables a hardware SPI driver for general-purpose reads
2030 and writes. As with CONFIG_SOFT_SPI, the board configuration
2031 must define a list of chip-select function pointers.
2032 Currently supported on some MPC8xxx processors. For an
2033 example, see include/configs/mpc8349emds.h.
2037 Enables the driver for the SPI controllers on i.MX and MXC
2038 SoCs. Currently i.MX31/35/51 are supported.
2040 - FPGA Support: CONFIG_FPGA
2042 Enables FPGA subsystem.
2044 CONFIG_FPGA_<vendor>
2046 Enables support for specific chip vendors.
2049 CONFIG_FPGA_<family>
2051 Enables support for FPGA family.
2052 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2056 Specify the number of FPGA devices to support.
2058 CONFIG_SYS_FPGA_PROG_FEEDBACK
2060 Enable printing of hash marks during FPGA configuration.
2062 CONFIG_SYS_FPGA_CHECK_BUSY
2064 Enable checks on FPGA configuration interface busy
2065 status by the configuration function. This option
2066 will require a board or device specific function to
2071 If defined, a function that provides delays in the FPGA
2072 configuration driver.
2074 CONFIG_SYS_FPGA_CHECK_CTRLC
2075 Allow Control-C to interrupt FPGA configuration
2077 CONFIG_SYS_FPGA_CHECK_ERROR
2079 Check for configuration errors during FPGA bitfile
2080 loading. For example, abort during Virtex II
2081 configuration if the INIT_B line goes low (which
2082 indicated a CRC error).
2084 CONFIG_SYS_FPGA_WAIT_INIT
2086 Maximum time to wait for the INIT_B line to deassert
2087 after PROB_B has been deasserted during a Virtex II
2088 FPGA configuration sequence. The default time is 500
2091 CONFIG_SYS_FPGA_WAIT_BUSY
2093 Maximum time to wait for BUSY to deassert during
2094 Virtex II FPGA configuration. The default is 5 ms.
2096 CONFIG_SYS_FPGA_WAIT_CONFIG
2098 Time to wait after FPGA configuration. The default is
2101 - Configuration Management:
2104 If defined, this string will be added to the U-Boot
2105 version information (U_BOOT_VERSION)
2107 - Vendor Parameter Protection:
2109 U-Boot considers the values of the environment
2110 variables "serial#" (Board Serial Number) and
2111 "ethaddr" (Ethernet Address) to be parameters that
2112 are set once by the board vendor / manufacturer, and
2113 protects these variables from casual modification by
2114 the user. Once set, these variables are read-only,
2115 and write or delete attempts are rejected. You can
2116 change this behaviour:
2118 If CONFIG_ENV_OVERWRITE is #defined in your config
2119 file, the write protection for vendor parameters is
2120 completely disabled. Anybody can change or delete
2123 Alternatively, if you #define _both_ CONFIG_ETHADDR
2124 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2125 Ethernet address is installed in the environment,
2126 which can be changed exactly ONCE by the user. [The
2127 serial# is unaffected by this, i. e. it remains
2133 Define this variable to enable the reservation of
2134 "protected RAM", i. e. RAM which is not overwritten
2135 by U-Boot. Define CONFIG_PRAM to hold the number of
2136 kB you want to reserve for pRAM. You can overwrite
2137 this default value by defining an environment
2138 variable "pram" to the number of kB you want to
2139 reserve. Note that the board info structure will
2140 still show the full amount of RAM. If pRAM is
2141 reserved, a new environment variable "mem" will
2142 automatically be defined to hold the amount of
2143 remaining RAM in a form that can be passed as boot
2144 argument to Linux, for instance like that:
2146 setenv bootargs ... mem=\${mem}
2149 This way you can tell Linux not to use this memory,
2150 either, which results in a memory region that will
2151 not be affected by reboots.
2153 *WARNING* If your board configuration uses automatic
2154 detection of the RAM size, you must make sure that
2155 this memory test is non-destructive. So far, the
2156 following board configurations are known to be
2159 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
2160 HERMES, IP860, RPXlite, LWMON, LANTEC,
2166 Define this variable to stop the system in case of a
2167 fatal error, so that you have to reset it manually.
2168 This is probably NOT a good idea for an embedded
2169 system where you want the system to reboot
2170 automatically as fast as possible, but it may be
2171 useful during development since you can try to debug
2172 the conditions that lead to the situation.
2174 CONFIG_NET_RETRY_COUNT
2176 This variable defines the number of retries for
2177 network operations like ARP, RARP, TFTP, or BOOTP
2178 before giving up the operation. If not defined, a
2179 default value of 5 is used.
2183 Timeout waiting for an ARP reply in milliseconds.
2187 Timeout in milliseconds used in NFS protocol.
2188 If you encounter "ERROR: Cannot umount" in nfs command,
2189 try longer timeout such as
2190 #define CONFIG_NFS_TIMEOUT 10000UL
2192 - Command Interpreter:
2193 CONFIG_AUTO_COMPLETE
2195 Enable auto completion of commands using TAB.
2197 Note that this feature has NOT been implemented yet
2198 for the "hush" shell.
2201 CONFIG_SYS_HUSH_PARSER
2203 Define this variable to enable the "hush" shell (from
2204 Busybox) as command line interpreter, thus enabling
2205 powerful command line syntax like
2206 if...then...else...fi conditionals or `&&' and '||'
2207 constructs ("shell scripts").
2209 If undefined, you get the old, much simpler behaviour
2210 with a somewhat smaller memory footprint.
2213 CONFIG_SYS_PROMPT_HUSH_PS2
2215 This defines the secondary prompt string, which is
2216 printed when the command interpreter needs more input
2217 to complete a command. Usually "> ".
2221 In the current implementation, the local variables
2222 space and global environment variables space are
2223 separated. Local variables are those you define by
2224 simply typing `name=value'. To access a local
2225 variable later on, you have write `$name' or
2226 `${name}'; to execute the contents of a variable
2227 directly type `$name' at the command prompt.
2229 Global environment variables are those you use
2230 setenv/printenv to work with. To run a command stored
2231 in such a variable, you need to use the run command,
2232 and you must not use the '$' sign to access them.
2234 To store commands and special characters in a
2235 variable, please use double quotation marks
2236 surrounding the whole text of the variable, instead
2237 of the backslashes before semicolons and special
2240 - Commandline Editing and History:
2241 CONFIG_CMDLINE_EDITING
2243 Enable editing and History functions for interactive
2244 commandline input operations
2246 - Default Environment:
2247 CONFIG_EXTRA_ENV_SETTINGS
2249 Define this to contain any number of null terminated
2250 strings (variable = value pairs) that will be part of
2251 the default environment compiled into the boot image.
2253 For example, place something like this in your
2254 board's config file:
2256 #define CONFIG_EXTRA_ENV_SETTINGS \
2260 Warning: This method is based on knowledge about the
2261 internal format how the environment is stored by the
2262 U-Boot code. This is NOT an official, exported
2263 interface! Although it is unlikely that this format
2264 will change soon, there is no guarantee either.
2265 You better know what you are doing here.
2267 Note: overly (ab)use of the default environment is
2268 discouraged. Make sure to check other ways to preset
2269 the environment like the "source" command or the
2272 CONFIG_ENV_VARS_UBOOT_CONFIG
2274 Define this in order to add variables describing the
2275 U-Boot build configuration to the default environment.
2276 These will be named arch, cpu, board, vendor, and soc.
2278 Enabling this option will cause the following to be defined:
2286 - DataFlash Support:
2287 CONFIG_HAS_DATAFLASH
2289 Defining this option enables DataFlash features and
2290 allows to read/write in Dataflash via the standard
2293 - Serial Flash support
2296 Defining this option enables SPI flash commands
2297 'sf probe/read/write/erase/update'.
2299 Usage requires an initial 'probe' to define the serial
2300 flash parameters, followed by read/write/erase/update
2303 The following defaults may be provided by the platform
2304 to handle the common case when only a single serial
2305 flash is present on the system.
2307 CONFIG_SF_DEFAULT_BUS Bus identifier
2308 CONFIG_SF_DEFAULT_CS Chip-select
2309 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2310 CONFIG_SF_DEFAULT_SPEED in Hz
2312 - SystemACE Support:
2315 Adding this option adds support for Xilinx SystemACE
2316 chips attached via some sort of local bus. The address
2317 of the chip must also be defined in the
2318 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2320 #define CONFIG_SYSTEMACE
2321 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2323 When SystemACE support is added, the "ace" device type
2324 becomes available to the fat commands, i.e. fatls.
2326 - TFTP Fixed UDP Port:
2329 If this is defined, the environment variable tftpsrcp
2330 is used to supply the TFTP UDP source port value.
2331 If tftpsrcp isn't defined, the normal pseudo-random port
2332 number generator is used.
2334 Also, the environment variable tftpdstp is used to supply
2335 the TFTP UDP destination port value. If tftpdstp isn't
2336 defined, the normal port 69 is used.
2338 The purpose for tftpsrcp is to allow a TFTP server to
2339 blindly start the TFTP transfer using the pre-configured
2340 target IP address and UDP port. This has the effect of
2341 "punching through" the (Windows XP) firewall, allowing
2342 the remainder of the TFTP transfer to proceed normally.
2343 A better solution is to properly configure the firewall,
2344 but sometimes that is not allowed.
2346 - Show boot progress:
2347 CONFIG_SHOW_BOOT_PROGRESS
2349 Defining this option allows to add some board-
2350 specific code (calling a user-provided function
2351 "show_boot_progress(int)") that enables you to show
2352 the system's boot progress on some display (for
2353 example, some LED's) on your board. At the moment,
2354 the following checkpoints are implemented:
2356 - Detailed boot stage timing
2358 Define this option to get detailed timing of each stage
2359 of the boot process.
2361 CONFIG_BOOTSTAGE_USER_COUNT
2362 This is the number of available user bootstage records.
2363 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2364 a new ID will be allocated from this stash. If you exceed
2365 the limit, recording will stop.
2367 CONFIG_BOOTSTAGE_REPORT
2368 Define this to print a report before boot, similar to this:
2370 Timer summary in microseconds:
2373 3,575,678 3,575,678 board_init_f start
2374 3,575,695 17 arch_cpu_init A9
2375 3,575,777 82 arch_cpu_init done
2376 3,659,598 83,821 board_init_r start
2377 3,910,375 250,777 main_loop
2378 29,916,167 26,005,792 bootm_start
2379 30,361,327 445,160 start_kernel
2381 Legacy uImage format:
2384 1 common/cmd_bootm.c before attempting to boot an image
2385 -1 common/cmd_bootm.c Image header has bad magic number
2386 2 common/cmd_bootm.c Image header has correct magic number
2387 -2 common/cmd_bootm.c Image header has bad checksum
2388 3 common/cmd_bootm.c Image header has correct checksum
2389 -3 common/cmd_bootm.c Image data has bad checksum
2390 4 common/cmd_bootm.c Image data has correct checksum
2391 -4 common/cmd_bootm.c Image is for unsupported architecture
2392 5 common/cmd_bootm.c Architecture check OK
2393 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2394 6 common/cmd_bootm.c Image Type check OK
2395 -6 common/cmd_bootm.c gunzip uncompression error
2396 -7 common/cmd_bootm.c Unimplemented compression type
2397 7 common/cmd_bootm.c Uncompression OK
2398 8 common/cmd_bootm.c No uncompress/copy overwrite error
2399 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2401 9 common/image.c Start initial ramdisk verification
2402 -10 common/image.c Ramdisk header has bad magic number
2403 -11 common/image.c Ramdisk header has bad checksum
2404 10 common/image.c Ramdisk header is OK
2405 -12 common/image.c Ramdisk data has bad checksum
2406 11 common/image.c Ramdisk data has correct checksum
2407 12 common/image.c Ramdisk verification complete, start loading
2408 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2409 13 common/image.c Start multifile image verification
2410 14 common/image.c No initial ramdisk, no multifile, continue.
2412 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2414 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2415 -31 post/post.c POST test failed, detected by post_output_backlog()
2416 -32 post/post.c POST test failed, detected by post_run_single()
2418 34 common/cmd_doc.c before loading a Image from a DOC device
2419 -35 common/cmd_doc.c Bad usage of "doc" command
2420 35 common/cmd_doc.c correct usage of "doc" command
2421 -36 common/cmd_doc.c No boot device
2422 36 common/cmd_doc.c correct boot device
2423 -37 common/cmd_doc.c Unknown Chip ID on boot device
2424 37 common/cmd_doc.c correct chip ID found, device available
2425 -38 common/cmd_doc.c Read Error on boot device
2426 38 common/cmd_doc.c reading Image header from DOC device OK
2427 -39 common/cmd_doc.c Image header has bad magic number
2428 39 common/cmd_doc.c Image header has correct magic number
2429 -40 common/cmd_doc.c Error reading Image from DOC device
2430 40 common/cmd_doc.c Image header has correct magic number
2431 41 common/cmd_ide.c before loading a Image from a IDE device
2432 -42 common/cmd_ide.c Bad usage of "ide" command
2433 42 common/cmd_ide.c correct usage of "ide" command
2434 -43 common/cmd_ide.c No boot device
2435 43 common/cmd_ide.c boot device found
2436 -44 common/cmd_ide.c Device not available
2437 44 common/cmd_ide.c Device available
2438 -45 common/cmd_ide.c wrong partition selected
2439 45 common/cmd_ide.c partition selected
2440 -46 common/cmd_ide.c Unknown partition table
2441 46 common/cmd_ide.c valid partition table found
2442 -47 common/cmd_ide.c Invalid partition type
2443 47 common/cmd_ide.c correct partition type
2444 -48 common/cmd_ide.c Error reading Image Header on boot device
2445 48 common/cmd_ide.c reading Image Header from IDE device OK
2446 -49 common/cmd_ide.c Image header has bad magic number
2447 49 common/cmd_ide.c Image header has correct magic number
2448 -50 common/cmd_ide.c Image header has bad checksum
2449 50 common/cmd_ide.c Image header has correct checksum
2450 -51 common/cmd_ide.c Error reading Image from IDE device
2451 51 common/cmd_ide.c reading Image from IDE device OK
2452 52 common/cmd_nand.c before loading a Image from a NAND device
2453 -53 common/cmd_nand.c Bad usage of "nand" command
2454 53 common/cmd_nand.c correct usage of "nand" command
2455 -54 common/cmd_nand.c No boot device
2456 54 common/cmd_nand.c boot device found
2457 -55 common/cmd_nand.c Unknown Chip ID on boot device
2458 55 common/cmd_nand.c correct chip ID found, device available
2459 -56 common/cmd_nand.c Error reading Image Header on boot device
2460 56 common/cmd_nand.c reading Image Header from NAND device OK
2461 -57 common/cmd_nand.c Image header has bad magic number
2462 57 common/cmd_nand.c Image header has correct magic number
2463 -58 common/cmd_nand.c Error reading Image from NAND device
2464 58 common/cmd_nand.c reading Image from NAND device OK
2466 -60 common/env_common.c Environment has a bad CRC, using default
2468 64 net/eth.c starting with Ethernet configuration.
2469 -64 net/eth.c no Ethernet found.
2470 65 net/eth.c Ethernet found.
2472 -80 common/cmd_net.c usage wrong
2473 80 common/cmd_net.c before calling NetLoop()
2474 -81 common/cmd_net.c some error in NetLoop() occurred
2475 81 common/cmd_net.c NetLoop() back without error
2476 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2477 82 common/cmd_net.c trying automatic boot
2478 83 common/cmd_net.c running "source" command
2479 -83 common/cmd_net.c some error in automatic boot or "source" command
2480 84 common/cmd_net.c end without errors
2485 100 common/cmd_bootm.c Kernel FIT Image has correct format
2486 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2487 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2488 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2489 102 common/cmd_bootm.c Kernel unit name specified
2490 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2491 103 common/cmd_bootm.c Found configuration node
2492 104 common/cmd_bootm.c Got kernel subimage node offset
2493 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2494 105 common/cmd_bootm.c Kernel subimage hash verification OK
2495 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2496 106 common/cmd_bootm.c Architecture check OK
2497 -106 common/cmd_bootm.c Kernel subimage has wrong type
2498 107 common/cmd_bootm.c Kernel subimage type OK
2499 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2500 108 common/cmd_bootm.c Got kernel subimage data/size
2501 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2502 -109 common/cmd_bootm.c Can't get kernel subimage type
2503 -110 common/cmd_bootm.c Can't get kernel subimage comp
2504 -111 common/cmd_bootm.c Can't get kernel subimage os
2505 -112 common/cmd_bootm.c Can't get kernel subimage load address
2506 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2508 120 common/image.c Start initial ramdisk verification
2509 -120 common/image.c Ramdisk FIT image has incorrect format
2510 121 common/image.c Ramdisk FIT image has correct format
2511 122 common/image.c No ramdisk subimage unit name, using configuration
2512 -122 common/image.c Can't get configuration for ramdisk subimage
2513 123 common/image.c Ramdisk unit name specified
2514 -124 common/image.c Can't get ramdisk subimage node offset
2515 125 common/image.c Got ramdisk subimage node offset
2516 -125 common/image.c Ramdisk subimage hash verification failed
2517 126 common/image.c Ramdisk subimage hash verification OK
2518 -126 common/image.c Ramdisk subimage for unsupported architecture
2519 127 common/image.c Architecture check OK
2520 -127 common/image.c Can't get ramdisk subimage data/size
2521 128 common/image.c Got ramdisk subimage data/size
2522 129 common/image.c Can't get ramdisk load address
2523 -129 common/image.c Got ramdisk load address
2525 -130 common/cmd_doc.c Incorrect FIT image format
2526 131 common/cmd_doc.c FIT image format OK
2528 -140 common/cmd_ide.c Incorrect FIT image format
2529 141 common/cmd_ide.c FIT image format OK
2531 -150 common/cmd_nand.c Incorrect FIT image format
2532 151 common/cmd_nand.c FIT image format OK
2534 - Standalone program support:
2535 CONFIG_STANDALONE_LOAD_ADDR
2537 This option defines a board specific value for the
2538 address where standalone program gets loaded, thus
2539 overwriting the architecture dependent default
2542 - Frame Buffer Address:
2545 Define CONFIG_FB_ADDR if you want to use specific
2546 address for frame buffer.
2547 Then system will reserve the frame buffer address to
2548 defined address instead of lcd_setmem (this function
2549 grabs the memory for frame buffer by panel's size).
2551 Please see board_init_f function.
2553 - Automatic software updates via TFTP server
2555 CONFIG_UPDATE_TFTP_CNT_MAX
2556 CONFIG_UPDATE_TFTP_MSEC_MAX
2558 These options enable and control the auto-update feature;
2559 for a more detailed description refer to doc/README.update.
2561 - MTD Support (mtdparts command, UBI support)
2564 Adds the MTD device infrastructure from the Linux kernel.
2565 Needed for mtdparts command support.
2567 CONFIG_MTD_PARTITIONS
2569 Adds the MTD partitioning infrastructure from the Linux
2570 kernel. Needed for UBI support.
2574 Enable building of SPL globally.
2577 LDSCRIPT for linking the SPL binary.
2580 Maximum binary size (text, data and rodata) of the SPL binary.
2582 CONFIG_SPL_TEXT_BASE
2583 TEXT_BASE for linking the SPL binary.
2585 CONFIG_SPL_BSS_START_ADDR
2586 Link address for the BSS within the SPL binary.
2588 CONFIG_SPL_BSS_MAX_SIZE
2589 Maximum binary size of the BSS section of the SPL binary.
2592 Adress of the start of the stack SPL will use
2594 CONFIG_SYS_SPL_MALLOC_START
2595 Starting address of the malloc pool used in SPL.
2597 CONFIG_SYS_SPL_MALLOC_SIZE
2598 The size of the malloc pool used in SPL.
2600 CONFIG_SPL_DISPLAY_PRINT
2601 For ARM, enable an optional function to print more information
2602 about the running system.
2604 CONFIG_SPL_LIBCOMMON_SUPPORT
2605 Support for common/libcommon.o in SPL binary
2607 CONFIG_SPL_LIBDISK_SUPPORT
2608 Support for disk/libdisk.o in SPL binary
2610 CONFIG_SPL_I2C_SUPPORT
2611 Support for drivers/i2c/libi2c.o in SPL binary
2613 CONFIG_SPL_GPIO_SUPPORT
2614 Support for drivers/gpio/libgpio.o in SPL binary
2616 CONFIG_SPL_MMC_SUPPORT
2617 Support for drivers/mmc/libmmc.o in SPL binary
2619 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2620 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2621 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2622 Address, size and partition on the MMC to load U-Boot from
2623 when the MMC is being used in raw mode.
2625 CONFIG_SPL_FAT_SUPPORT
2626 Support for fs/fat/libfat.o in SPL binary
2628 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2629 Filename to read to load U-Boot when reading from FAT
2631 CONFIG_SPL_NAND_SIMPLE
2632 Support for drivers/mtd/nand/libnand.o in SPL binary
2634 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2635 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2636 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2637 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2638 CONFIG_SYS_NAND_ECCBYTES
2639 Defines the size and behavior of the NAND that SPL uses
2640 to read U-Boot with CONFIG_SPL_NAND_SIMPLE
2642 CONFIG_SYS_NAND_U_BOOT_OFFS
2643 Location in NAND for CONFIG_SPL_NAND_SIMPLE to read U-Boot
2646 CONFIG_SYS_NAND_U_BOOT_START
2647 Location in memory for CONFIG_SPL_NAND_SIMPLE to load U-Boot
2650 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2651 Define this if you need to first read the OOB and then the
2652 data. This is used for example on davinci plattforms.
2654 CONFIG_SPL_OMAP3_ID_NAND
2655 Support for an OMAP3-specific set of functions to return the
2656 ID and MFR of the first attached NAND chip, if present.
2658 CONFIG_SPL_SERIAL_SUPPORT
2659 Support for drivers/serial/libserial.o in SPL binary
2661 CONFIG_SPL_SPI_FLASH_SUPPORT
2662 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2664 CONFIG_SPL_SPI_SUPPORT
2665 Support for drivers/spi/libspi.o in SPL binary
2667 CONFIG_SPL_LIBGENERIC_SUPPORT
2668 Support for lib/libgeneric.o in SPL binary
2673 [so far only for SMDK2400 boards]
2675 - Modem support enable:
2676 CONFIG_MODEM_SUPPORT
2678 - RTS/CTS Flow control enable:
2681 - Modem debug support:
2682 CONFIG_MODEM_SUPPORT_DEBUG
2684 Enables debugging stuff (char screen[1024], dbg())
2685 for modem support. Useful only with BDI2000.
2687 - Interrupt support (PPC):
2689 There are common interrupt_init() and timer_interrupt()
2690 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2691 for CPU specific initialization. interrupt_init_cpu()
2692 should set decrementer_count to appropriate value. If
2693 CPU resets decrementer automatically after interrupt
2694 (ppc4xx) it should set decrementer_count to zero.
2695 timer_interrupt() calls timer_interrupt_cpu() for CPU
2696 specific handling. If board has watchdog / status_led
2697 / other_activity_monitor it works automatically from
2698 general timer_interrupt().
2702 In the target system modem support is enabled when a
2703 specific key (key combination) is pressed during
2704 power-on. Otherwise U-Boot will boot normally
2705 (autoboot). The key_pressed() function is called from
2706 board_init(). Currently key_pressed() is a dummy
2707 function, returning 1 and thus enabling modem
2710 If there are no modem init strings in the
2711 environment, U-Boot proceed to autoboot; the
2712 previous output (banner, info printfs) will be
2715 See also: doc/README.Modem
2717 Board initialization settings:
2718 ------------------------------
2720 During Initialization u-boot calls a number of board specific functions
2721 to allow the preparation of board specific prerequisites, e.g. pin setup
2722 before drivers are initialized. To enable these callbacks the
2723 following configuration macros have to be defined. Currently this is
2724 architecture specific, so please check arch/your_architecture/lib/board.c
2725 typically in board_init_f() and board_init_r().
2727 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2728 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2729 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2730 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2732 Configuration Settings:
2733 -----------------------
2735 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2736 undefine this when you're short of memory.
2738 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2739 width of the commands listed in the 'help' command output.
2741 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2742 prompt for user input.
2744 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2746 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2748 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2750 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2751 the application (usually a Linux kernel) when it is
2754 - CONFIG_SYS_BAUDRATE_TABLE:
2755 List of legal baudrate settings for this board.
2757 - CONFIG_SYS_CONSOLE_INFO_QUIET
2758 Suppress display of console information at boot.
2760 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2761 If the board specific function
2762 extern int overwrite_console (void);
2763 returns 1, the stdin, stderr and stdout are switched to the
2764 serial port, else the settings in the environment are used.
2766 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2767 Enable the call to overwrite_console().
2769 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2770 Enable overwrite of previous console environment settings.
2772 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2773 Begin and End addresses of the area used by the
2776 - CONFIG_SYS_ALT_MEMTEST:
2777 Enable an alternate, more extensive memory test.
2779 - CONFIG_SYS_MEMTEST_SCRATCH:
2780 Scratch address used by the alternate memory test
2781 You only need to set this if address zero isn't writeable
2783 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2784 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2785 this specified memory area will get subtracted from the top
2786 (end) of RAM and won't get "touched" at all by U-Boot. By
2787 fixing up gd->ram_size the Linux kernel should gets passed
2788 the now "corrected" memory size and won't touch it either.
2789 This should work for arch/ppc and arch/powerpc. Only Linux
2790 board ports in arch/powerpc with bootwrapper support that
2791 recalculate the memory size from the SDRAM controller setup
2792 will have to get fixed in Linux additionally.
2794 This option can be used as a workaround for the 440EPx/GRx
2795 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2798 WARNING: Please make sure that this value is a multiple of
2799 the Linux page size (normally 4k). If this is not the case,
2800 then the end address of the Linux memory will be located at a
2801 non page size aligned address and this could cause major
2804 - CONFIG_SYS_TFTP_LOADADDR:
2805 Default load address for network file downloads
2807 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2808 Enable temporary baudrate change while serial download
2810 - CONFIG_SYS_SDRAM_BASE:
2811 Physical start address of SDRAM. _Must_ be 0 here.
2813 - CONFIG_SYS_MBIO_BASE:
2814 Physical start address of Motherboard I/O (if using a
2817 - CONFIG_SYS_FLASH_BASE:
2818 Physical start address of Flash memory.
2820 - CONFIG_SYS_MONITOR_BASE:
2821 Physical start address of boot monitor code (set by
2822 make config files to be same as the text base address
2823 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2824 CONFIG_SYS_FLASH_BASE when booting from flash.
2826 - CONFIG_SYS_MONITOR_LEN:
2827 Size of memory reserved for monitor code, used to
2828 determine _at_compile_time_ (!) if the environment is
2829 embedded within the U-Boot image, or in a separate
2832 - CONFIG_SYS_MALLOC_LEN:
2833 Size of DRAM reserved for malloc() use.
2835 - CONFIG_SYS_BOOTM_LEN:
2836 Normally compressed uImages are limited to an
2837 uncompressed size of 8 MBytes. If this is not enough,
2838 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2839 to adjust this setting to your needs.
2841 - CONFIG_SYS_BOOTMAPSZ:
2842 Maximum size of memory mapped by the startup code of
2843 the Linux kernel; all data that must be processed by
2844 the Linux kernel (bd_info, boot arguments, FDT blob if
2845 used) must be put below this limit, unless "bootm_low"
2846 enviroment variable is defined and non-zero. In such case
2847 all data for the Linux kernel must be between "bootm_low"
2848 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2849 variable "bootm_mapsize" will override the value of
2850 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2851 then the value in "bootm_size" will be used instead.
2853 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2854 Enable initrd_high functionality. If defined then the
2855 initrd_high feature is enabled and the bootm ramdisk subcommand
2858 - CONFIG_SYS_BOOT_GET_CMDLINE:
2859 Enables allocating and saving kernel cmdline in space between
2860 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2862 - CONFIG_SYS_BOOT_GET_KBD:
2863 Enables allocating and saving a kernel copy of the bd_info in
2864 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2866 - CONFIG_SYS_MAX_FLASH_BANKS:
2867 Max number of Flash memory banks
2869 - CONFIG_SYS_MAX_FLASH_SECT:
2870 Max number of sectors on a Flash chip
2872 - CONFIG_SYS_FLASH_ERASE_TOUT:
2873 Timeout for Flash erase operations (in ms)
2875 - CONFIG_SYS_FLASH_WRITE_TOUT:
2876 Timeout for Flash write operations (in ms)
2878 - CONFIG_SYS_FLASH_LOCK_TOUT
2879 Timeout for Flash set sector lock bit operation (in ms)
2881 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2882 Timeout for Flash clear lock bits operation (in ms)
2884 - CONFIG_SYS_FLASH_PROTECTION
2885 If defined, hardware flash sectors protection is used
2886 instead of U-Boot software protection.
2888 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2890 Enable TFTP transfers directly to flash memory;
2891 without this option such a download has to be
2892 performed in two steps: (1) download to RAM, and (2)
2893 copy from RAM to flash.
2895 The two-step approach is usually more reliable, since
2896 you can check if the download worked before you erase
2897 the flash, but in some situations (when system RAM is
2898 too limited to allow for a temporary copy of the
2899 downloaded image) this option may be very useful.
2901 - CONFIG_SYS_FLASH_CFI:
2902 Define if the flash driver uses extra elements in the
2903 common flash structure for storing flash geometry.
2905 - CONFIG_FLASH_CFI_DRIVER
2906 This option also enables the building of the cfi_flash driver
2907 in the drivers directory
2909 - CONFIG_FLASH_CFI_MTD
2910 This option enables the building of the cfi_mtd driver
2911 in the drivers directory. The driver exports CFI flash
2914 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2915 Use buffered writes to flash.
2917 - CONFIG_FLASH_SPANSION_S29WS_N
2918 s29ws-n MirrorBit flash has non-standard addresses for buffered
2921 - CONFIG_SYS_FLASH_QUIET_TEST
2922 If this option is defined, the common CFI flash doesn't
2923 print it's warning upon not recognized FLASH banks. This
2924 is useful, if some of the configured banks are only
2925 optionally available.
2927 - CONFIG_FLASH_SHOW_PROGRESS
2928 If defined (must be an integer), print out countdown
2929 digits and dots. Recommended value: 45 (9..1) for 80
2930 column displays, 15 (3..1) for 40 column displays.
2932 - CONFIG_SYS_RX_ETH_BUFFER:
2933 Defines the number of Ethernet receive buffers. On some
2934 Ethernet controllers it is recommended to set this value
2935 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2936 buffers can be full shortly after enabling the interface
2937 on high Ethernet traffic.
2938 Defaults to 4 if not defined.
2940 - CONFIG_ENV_MAX_ENTRIES
2942 Maximum number of entries in the hash table that is used
2943 internally to store the environment settings. The default
2944 setting is supposed to be generous and should work in most
2945 cases. This setting can be used to tune behaviour; see
2946 lib/hashtable.c for details.
2948 The following definitions that deal with the placement and management
2949 of environment data (variable area); in general, we support the
2950 following configurations:
2952 - CONFIG_BUILD_ENVCRC:
2954 Builds up envcrc with the target environment so that external utils
2955 may easily extract it and embed it in final U-Boot images.
2957 - CONFIG_ENV_IS_IN_FLASH:
2959 Define this if the environment is in flash memory.
2961 a) The environment occupies one whole flash sector, which is
2962 "embedded" in the text segment with the U-Boot code. This
2963 happens usually with "bottom boot sector" or "top boot
2964 sector" type flash chips, which have several smaller
2965 sectors at the start or the end. For instance, such a
2966 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2967 such a case you would place the environment in one of the
2968 4 kB sectors - with U-Boot code before and after it. With
2969 "top boot sector" type flash chips, you would put the
2970 environment in one of the last sectors, leaving a gap
2971 between U-Boot and the environment.
2973 - CONFIG_ENV_OFFSET:
2975 Offset of environment data (variable area) to the
2976 beginning of flash memory; for instance, with bottom boot
2977 type flash chips the second sector can be used: the offset
2978 for this sector is given here.
2980 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2984 This is just another way to specify the start address of
2985 the flash sector containing the environment (instead of
2988 - CONFIG_ENV_SECT_SIZE:
2990 Size of the sector containing the environment.
2993 b) Sometimes flash chips have few, equal sized, BIG sectors.
2994 In such a case you don't want to spend a whole sector for
2999 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3000 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3001 of this flash sector for the environment. This saves
3002 memory for the RAM copy of the environment.
3004 It may also save flash memory if you decide to use this
3005 when your environment is "embedded" within U-Boot code,
3006 since then the remainder of the flash sector could be used
3007 for U-Boot code. It should be pointed out that this is
3008 STRONGLY DISCOURAGED from a robustness point of view:
3009 updating the environment in flash makes it always
3010 necessary to erase the WHOLE sector. If something goes
3011 wrong before the contents has been restored from a copy in
3012 RAM, your target system will be dead.
3014 - CONFIG_ENV_ADDR_REDUND
3015 CONFIG_ENV_SIZE_REDUND
3017 These settings describe a second storage area used to hold
3018 a redundant copy of the environment data, so that there is
3019 a valid backup copy in case there is a power failure during
3020 a "saveenv" operation.
3022 BE CAREFUL! Any changes to the flash layout, and some changes to the
3023 source code will make it necessary to adapt <board>/u-boot.lds*
3027 - CONFIG_ENV_IS_IN_NVRAM:
3029 Define this if you have some non-volatile memory device
3030 (NVRAM, battery buffered SRAM) which you want to use for the
3036 These two #defines are used to determine the memory area you
3037 want to use for environment. It is assumed that this memory
3038 can just be read and written to, without any special
3041 BE CAREFUL! The first access to the environment happens quite early
3042 in U-Boot initalization (when we try to get the setting of for the
3043 console baudrate). You *MUST* have mapped your NVRAM area then, or
3046 Please note that even with NVRAM we still use a copy of the
3047 environment in RAM: we could work on NVRAM directly, but we want to
3048 keep settings there always unmodified except somebody uses "saveenv"
3049 to save the current settings.
3052 - CONFIG_ENV_IS_IN_EEPROM:
3054 Use this if you have an EEPROM or similar serial access
3055 device and a driver for it.
3057 - CONFIG_ENV_OFFSET:
3060 These two #defines specify the offset and size of the
3061 environment area within the total memory of your EEPROM.
3063 - CONFIG_SYS_I2C_EEPROM_ADDR:
3064 If defined, specified the chip address of the EEPROM device.
3065 The default address is zero.
3067 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3068 If defined, the number of bits used to address bytes in a
3069 single page in the EEPROM device. A 64 byte page, for example
3070 would require six bits.
3072 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3073 If defined, the number of milliseconds to delay between
3074 page writes. The default is zero milliseconds.
3076 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3077 The length in bytes of the EEPROM memory array address. Note
3078 that this is NOT the chip address length!
3080 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3081 EEPROM chips that implement "address overflow" are ones
3082 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3083 address and the extra bits end up in the "chip address" bit
3084 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3087 Note that we consider the length of the address field to
3088 still be one byte because the extra address bits are hidden
3089 in the chip address.
3091 - CONFIG_SYS_EEPROM_SIZE:
3092 The size in bytes of the EEPROM device.
3094 - CONFIG_ENV_EEPROM_IS_ON_I2C
3095 define this, if you have I2C and SPI activated, and your
3096 EEPROM, which holds the environment, is on the I2C bus.
3098 - CONFIG_I2C_ENV_EEPROM_BUS
3099 if you have an Environment on an EEPROM reached over
3100 I2C muxes, you can define here, how to reach this
3101 EEPROM. For example:
3103 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3105 EEPROM which holds the environment, is reached over
3106 a pca9547 i2c mux with address 0x70, channel 3.
3108 - CONFIG_ENV_IS_IN_DATAFLASH:
3110 Define this if you have a DataFlash memory device which you
3111 want to use for the environment.
3113 - CONFIG_ENV_OFFSET:
3117 These three #defines specify the offset and size of the
3118 environment area within the total memory of your DataFlash placed
3119 at the specified address.
3121 - CONFIG_ENV_IS_IN_REMOTE:
3123 Define this if you have a remote memory space which you
3124 want to use for the local device's environment.
3129 These two #defines specify the address and size of the
3130 environment area within the remote memory space. The
3131 local device can get the environment from remote memory
3132 space by SRIO or PCIE links.
3134 BE CAREFUL! For some special cases, the local device can not use
3135 "saveenv" command. For example, the local device will get the
3136 environment stored in a remote NOR flash by SRIO or PCIE link,
3137 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3139 - CONFIG_ENV_IS_IN_NAND:
3141 Define this if you have a NAND device which you want to use
3142 for the environment.
3144 - CONFIG_ENV_OFFSET:
3147 These two #defines specify the offset and size of the environment
3148 area within the first NAND device. CONFIG_ENV_OFFSET must be
3149 aligned to an erase block boundary.
3151 - CONFIG_ENV_OFFSET_REDUND (optional):
3153 This setting describes a second storage area of CONFIG_ENV_SIZE
3154 size used to hold a redundant copy of the environment data, so
3155 that there is a valid backup copy in case there is a power failure
3156 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3157 aligned to an erase block boundary.
3159 - CONFIG_ENV_RANGE (optional):
3161 Specifies the length of the region in which the environment
3162 can be written. This should be a multiple of the NAND device's
3163 block size. Specifying a range with more erase blocks than
3164 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3165 the range to be avoided.
3167 - CONFIG_ENV_OFFSET_OOB (optional):
3169 Enables support for dynamically retrieving the offset of the
3170 environment from block zero's out-of-band data. The
3171 "nand env.oob" command can be used to record this offset.
3172 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3173 using CONFIG_ENV_OFFSET_OOB.
3175 - CONFIG_NAND_ENV_DST
3177 Defines address in RAM to which the nand_spl code should copy the
3178 environment. If redundant environment is used, it will be copied to
3179 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3181 - CONFIG_SYS_SPI_INIT_OFFSET
3183 Defines offset to the initial SPI buffer area in DPRAM. The
3184 area is used at an early stage (ROM part) if the environment
3185 is configured to reside in the SPI EEPROM: We need a 520 byte
3186 scratch DPRAM area. It is used between the two initialization
3187 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3188 to be a good choice since it makes it far enough from the
3189 start of the data area as well as from the stack pointer.
3191 Please note that the environment is read-only until the monitor
3192 has been relocated to RAM and a RAM copy of the environment has been
3193 created; also, when using EEPROM you will have to use getenv_f()
3194 until then to read environment variables.
3196 The environment is protected by a CRC32 checksum. Before the monitor
3197 is relocated into RAM, as a result of a bad CRC you will be working
3198 with the compiled-in default environment - *silently*!!! [This is
3199 necessary, because the first environment variable we need is the
3200 "baudrate" setting for the console - if we have a bad CRC, we don't
3201 have any device yet where we could complain.]
3203 Note: once the monitor has been relocated, then it will complain if
3204 the default environment is used; a new CRC is computed as soon as you
3205 use the "saveenv" command to store a valid environment.
3207 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3208 Echo the inverted Ethernet link state to the fault LED.
3210 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3211 also needs to be defined.
3213 - CONFIG_SYS_FAULT_MII_ADDR:
3214 MII address of the PHY to check for the Ethernet link state.
3216 - CONFIG_NS16550_MIN_FUNCTIONS:
3217 Define this if you desire to only have use of the NS16550_init
3218 and NS16550_putc functions for the serial driver located at
3219 drivers/serial/ns16550.c. This option is useful for saving
3220 space for already greatly restricted images, including but not
3221 limited to NAND_SPL configurations.
3223 Low Level (hardware related) configuration options:
3224 ---------------------------------------------------
3226 - CONFIG_SYS_CACHELINE_SIZE:
3227 Cache Line Size of the CPU.
3229 - CONFIG_SYS_DEFAULT_IMMR:
3230 Default address of the IMMR after system reset.
3232 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3233 and RPXsuper) to be able to adjust the position of
3234 the IMMR register after a reset.
3236 - CONFIG_SYS_CCSRBAR_DEFAULT:
3237 Default (power-on reset) physical address of CCSR on Freescale
3240 - CONFIG_SYS_CCSRBAR:
3241 Virtual address of CCSR. On a 32-bit build, this is typically
3242 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3244 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3245 for cross-platform code that uses that macro instead.
3247 - CONFIG_SYS_CCSRBAR_PHYS:
3248 Physical address of CCSR. CCSR can be relocated to a new
3249 physical address, if desired. In this case, this macro should
3250 be set to that address. Otherwise, it should be set to the
3251 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3252 is typically relocated on 36-bit builds. It is recommended
3253 that this macro be defined via the _HIGH and _LOW macros:
3255 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3256 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3258 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3259 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3260 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3261 used in assembly code, so it must not contain typecasts or
3262 integer size suffixes (e.g. "ULL").
3264 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3265 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3266 used in assembly code, so it must not contain typecasts or
3267 integer size suffixes (e.g. "ULL").
3269 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3270 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3271 forced to a value that ensures that CCSR is not relocated.
3273 - Floppy Disk Support:
3274 CONFIG_SYS_FDC_DRIVE_NUMBER
3276 the default drive number (default value 0)
3278 CONFIG_SYS_ISA_IO_STRIDE
3280 defines the spacing between FDC chipset registers
3283 CONFIG_SYS_ISA_IO_OFFSET
3285 defines the offset of register from address. It
3286 depends on which part of the data bus is connected to
3287 the FDC chipset. (default value 0)
3289 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3290 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3293 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3294 fdc_hw_init() is called at the beginning of the FDC
3295 setup. fdc_hw_init() must be provided by the board
3296 source code. It is used to make hardware dependant
3300 Most IDE controllers were designed to be connected with PCI
3301 interface. Only few of them were designed for AHB interface.
3302 When software is doing ATA command and data transfer to
3303 IDE devices through IDE-AHB controller, some additional
3304 registers accessing to these kind of IDE-AHB controller
3307 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3308 DO NOT CHANGE unless you know exactly what you're
3309 doing! (11-4) [MPC8xx/82xx systems only]
3311 - CONFIG_SYS_INIT_RAM_ADDR:
3313 Start address of memory area that can be used for
3314 initial data and stack; please note that this must be
3315 writable memory that is working WITHOUT special
3316 initialization, i. e. you CANNOT use normal RAM which
3317 will become available only after programming the
3318 memory controller and running certain initialization
3321 U-Boot uses the following memory types:
3322 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3323 - MPC824X: data cache
3324 - PPC4xx: data cache
3326 - CONFIG_SYS_GBL_DATA_OFFSET:
3328 Offset of the initial data structure in the memory
3329 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3330 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3331 data is located at the end of the available space
3332 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3333 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3334 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3335 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3338 On the MPC824X (or other systems that use the data
3339 cache for initial memory) the address chosen for
3340 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3341 point to an otherwise UNUSED address space between
3342 the top of RAM and the start of the PCI space.
3344 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3346 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3348 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3350 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3352 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3354 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3356 - CONFIG_SYS_OR_TIMING_SDRAM:
3359 - CONFIG_SYS_MAMR_PTA:
3360 periodic timer for refresh
3362 - CONFIG_SYS_DER: Debug Event Register (37-47)
3364 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3365 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3366 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3367 CONFIG_SYS_BR1_PRELIM:
3368 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3370 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3371 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3372 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3373 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3375 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3376 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3377 Machine Mode Register and Memory Periodic Timer
3378 Prescaler definitions (SDRAM timing)
3380 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3381 enable I2C microcode relocation patch (MPC8xx);
3382 define relocation offset in DPRAM [DSP2]
3384 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3385 enable SMC microcode relocation patch (MPC8xx);
3386 define relocation offset in DPRAM [SMC1]
3388 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3389 enable SPI microcode relocation patch (MPC8xx);
3390 define relocation offset in DPRAM [SCC4]
3392 - CONFIG_SYS_USE_OSCCLK:
3393 Use OSCM clock mode on MBX8xx board. Be careful,
3394 wrong setting might damage your board. Read
3395 doc/README.MBX before setting this variable!
3397 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3398 Offset of the bootmode word in DPRAM used by post
3399 (Power On Self Tests). This definition overrides
3400 #define'd default value in commproc.h resp.
3403 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3404 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3405 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3406 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3407 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3408 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3409 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3410 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3411 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3413 - CONFIG_PCI_DISABLE_PCIE:
3414 Disable PCI-Express on systems where it is supported but not
3417 - CONFIG_PCI_ENUM_ONLY
3418 Only scan through and get the devices on the busses.
3419 Don't do any setup work, presumably because someone or
3420 something has already done it, and we don't need to do it
3421 a second time. Useful for platforms that are pre-booted
3422 by coreboot or similar.
3425 Chip has SRIO or not
3428 Board has SRIO 1 port available
3431 Board has SRIO 2 port available
3433 - CONFIG_SYS_SRIOn_MEM_VIRT:
3434 Virtual Address of SRIO port 'n' memory region
3436 - CONFIG_SYS_SRIOn_MEM_PHYS:
3437 Physical Address of SRIO port 'n' memory region
3439 - CONFIG_SYS_SRIOn_MEM_SIZE:
3440 Size of SRIO port 'n' memory region
3442 - CONFIG_SYS_NDFC_16
3443 Defined to tell the NDFC that the NAND chip is using a
3446 - CONFIG_SYS_NDFC_EBC0_CFG
3447 Sets the EBC0_CFG register for the NDFC. If not defined
3448 a default value will be used.
3451 Get DDR timing information from an I2C EEPROM. Common
3452 with pluggable memory modules such as SODIMMs
3455 I2C address of the SPD EEPROM
3457 - CONFIG_SYS_SPD_BUS_NUM
3458 If SPD EEPROM is on an I2C bus other than the first
3459 one, specify here. Note that the value must resolve
3460 to something your driver can deal with.
3462 - CONFIG_SYS_DDR_RAW_TIMING
3463 Get DDR timing information from other than SPD. Common with
3464 soldered DDR chips onboard without SPD. DDR raw timing
3465 parameters are extracted from datasheet and hard-coded into
3466 header files or board specific files.
3468 - CONFIG_FSL_DDR_INTERACTIVE
3469 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3471 - CONFIG_SYS_83XX_DDR_USES_CS0
3472 Only for 83xx systems. If specified, then DDR should
3473 be configured using CS0 and CS1 instead of CS2 and CS3.
3475 - CONFIG_ETHER_ON_FEC[12]
3476 Define to enable FEC[12] on a 8xx series processor.
3478 - CONFIG_FEC[12]_PHY
3479 Define to the hardcoded PHY address which corresponds
3480 to the given FEC; i. e.
3481 #define CONFIG_FEC1_PHY 4
3482 means that the PHY with address 4 is connected to FEC1
3484 When set to -1, means to probe for first available.
3486 - CONFIG_FEC[12]_PHY_NORXERR
3487 The PHY does not have a RXERR line (RMII only).
3488 (so program the FEC to ignore it).
3491 Enable RMII mode for all FECs.
3492 Note that this is a global option, we can't
3493 have one FEC in standard MII mode and another in RMII mode.
3495 - CONFIG_CRC32_VERIFY
3496 Add a verify option to the crc32 command.
3499 => crc32 -v <address> <count> <crc32>
3501 Where address/count indicate a memory area
3502 and crc32 is the correct crc32 which the
3506 Add the "loopw" memory command. This only takes effect if
3507 the memory commands are activated globally (CONFIG_CMD_MEM).
3510 Add the "mdc" and "mwc" memory commands. These are cyclic
3515 This command will print 4 bytes (10,11,12,13) each 500 ms.
3517 => mwc.l 100 12345678 10
3518 This command will write 12345678 to address 100 all 10 ms.
3520 This only takes effect if the memory commands are activated
3521 globally (CONFIG_CMD_MEM).
3523 - CONFIG_SKIP_LOWLEVEL_INIT
3524 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3525 low level initializations (like setting up the memory
3526 controller) are omitted and/or U-Boot does not
3527 relocate itself into RAM.
3529 Normally this variable MUST NOT be defined. The only
3530 exception is when U-Boot is loaded (to RAM) by some
3531 other boot loader or by a debugger which performs
3532 these initializations itself.
3535 Modifies the behaviour of start.S when compiling a loader
3536 that is executed before the actual U-Boot. E.g. when
3537 compiling a NAND SPL.
3539 - CONFIG_USE_ARCH_MEMCPY
3540 CONFIG_USE_ARCH_MEMSET
3541 If these options are used a optimized version of memcpy/memset will
3542 be used if available. These functions may be faster under some
3543 conditions but may increase the binary size.
3545 Freescale QE/FMAN Firmware Support:
3546 -----------------------------------
3548 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3549 loading of "firmware", which is encoded in the QE firmware binary format.
3550 This firmware often needs to be loaded during U-Boot booting, so macros
3551 are used to identify the storage device (NOR flash, SPI, etc) and the address
3554 - CONFIG_SYS_QE_FMAN_FW_ADDR
3555 The address in the storage device where the firmware is located. The
3556 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3559 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3560 The maximum possible size of the firmware. The firmware binary format
3561 has a field that specifies the actual size of the firmware, but it
3562 might not be possible to read any part of the firmware unless some
3563 local storage is allocated to hold the entire firmware first.
3565 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3566 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3567 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3568 virtual address in NOR flash.
3570 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3571 Specifies that QE/FMAN firmware is located in NAND flash.
3572 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3574 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3575 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3576 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3578 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3579 Specifies that QE/FMAN firmware is located on the primary SPI
3580 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3582 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3583 Specifies that QE/FMAN firmware is located in the remote (master)
3584 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3585 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3586 window->master inbound window->master LAW->the ucode address in
3587 master's memory space.
3589 Building the Software:
3590 ======================
3592 Building U-Boot has been tested in several native build environments
3593 and in many different cross environments. Of course we cannot support
3594 all possibly existing versions of cross development tools in all
3595 (potentially obsolete) versions. In case of tool chain problems we
3596 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3597 which is extensively used to build and test U-Boot.
3599 If you are not using a native environment, it is assumed that you
3600 have GNU cross compiling tools available in your path. In this case,
3601 you must set the environment variable CROSS_COMPILE in your shell.
3602 Note that no changes to the Makefile or any other source files are
3603 necessary. For example using the ELDK on a 4xx CPU, please enter:
3605 $ CROSS_COMPILE=ppc_4xx-
3606 $ export CROSS_COMPILE
3608 Note: If you wish to generate Windows versions of the utilities in
3609 the tools directory you can use the MinGW toolchain
3610 (http://www.mingw.org). Set your HOST tools to the MinGW
3611 toolchain and execute 'make tools'. For example:
3613 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3615 Binaries such as tools/mkimage.exe will be created which can
3616 be executed on computers running Windows.
3618 U-Boot is intended to be simple to build. After installing the
3619 sources you must configure U-Boot for one specific board type. This
3624 where "NAME_config" is the name of one of the existing configu-
3625 rations; see boards.cfg for supported names.
3627 Note: for some board special configuration names may exist; check if
3628 additional information is available from the board vendor; for
3629 instance, the TQM823L systems are available without (standard)
3630 or with LCD support. You can select such additional "features"
3631 when choosing the configuration, i. e.
3634 - will configure for a plain TQM823L, i. e. no LCD support
3636 make TQM823L_LCD_config
3637 - will configure for a TQM823L with U-Boot console on LCD
3642 Finally, type "make all", and you should get some working U-Boot
3643 images ready for download to / installation on your system:
3645 - "u-boot.bin" is a raw binary image
3646 - "u-boot" is an image in ELF binary format
3647 - "u-boot.srec" is in Motorola S-Record format
3649 By default the build is performed locally and the objects are saved
3650 in the source directory. One of the two methods can be used to change
3651 this behavior and build U-Boot to some external directory:
3653 1. Add O= to the make command line invocations:
3655 make O=/tmp/build distclean
3656 make O=/tmp/build NAME_config
3657 make O=/tmp/build all
3659 2. Set environment variable BUILD_DIR to point to the desired location:
3661 export BUILD_DIR=/tmp/build
3666 Note that the command line "O=" setting overrides the BUILD_DIR environment
3670 Please be aware that the Makefiles assume you are using GNU make, so
3671 for instance on NetBSD you might need to use "gmake" instead of
3675 If the system board that you have is not listed, then you will need
3676 to port U-Boot to your hardware platform. To do this, follow these
3679 1. Add a new configuration option for your board to the toplevel
3680 "boards.cfg" file, using the existing entries as examples.
3681 Follow the instructions there to keep the boards in order.
3682 2. Create a new directory to hold your board specific code. Add any
3683 files you need. In your board directory, you will need at least
3684 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3685 3. Create a new configuration file "include/configs/<board>.h" for
3687 3. If you're porting U-Boot to a new CPU, then also create a new
3688 directory to hold your CPU specific code. Add any files you need.
3689 4. Run "make <board>_config" with your new name.
3690 5. Type "make", and you should get a working "u-boot.srec" file
3691 to be installed on your target system.
3692 6. Debug and solve any problems that might arise.
3693 [Of course, this last step is much harder than it sounds.]
3696 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3697 ==============================================================
3699 If you have modified U-Boot sources (for instance added a new board
3700 or support for new devices, a new CPU, etc.) you are expected to
3701 provide feedback to the other developers. The feedback normally takes
3702 the form of a "patch", i. e. a context diff against a certain (latest
3703 official or latest in the git repository) version of U-Boot sources.
3705 But before you submit such a patch, please verify that your modifi-
3706 cation did not break existing code. At least make sure that *ALL* of
3707 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3708 just run the "MAKEALL" script, which will configure and build U-Boot
3709 for ALL supported system. Be warned, this will take a while. You can
3710 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3711 environment variable to the script, i. e. to use the ELDK cross tools
3714 CROSS_COMPILE=ppc_8xx- MAKEALL
3716 or to build on a native PowerPC system you can type
3718 CROSS_COMPILE=' ' MAKEALL
3720 When using the MAKEALL script, the default behaviour is to build
3721 U-Boot in the source directory. This location can be changed by
3722 setting the BUILD_DIR environment variable. Also, for each target
3723 built, the MAKEALL script saves two log files (<target>.ERR and
3724 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3725 location can be changed by setting the MAKEALL_LOGDIR environment
3726 variable. For example:
3728 export BUILD_DIR=/tmp/build
3729 export MAKEALL_LOGDIR=/tmp/log
3730 CROSS_COMPILE=ppc_8xx- MAKEALL
3732 With the above settings build objects are saved in the /tmp/build,
3733 log files are saved in the /tmp/log and the source tree remains clean
3734 during the whole build process.
3737 See also "U-Boot Porting Guide" below.
3740 Monitor Commands - Overview:
3741 ============================
3743 go - start application at address 'addr'
3744 run - run commands in an environment variable
3745 bootm - boot application image from memory
3746 bootp - boot image via network using BootP/TFTP protocol
3747 bootz - boot zImage from memory
3748 tftpboot- boot image via network using TFTP protocol
3749 and env variables "ipaddr" and "serverip"
3750 (and eventually "gatewayip")
3751 tftpput - upload a file via network using TFTP protocol
3752 rarpboot- boot image via network using RARP/TFTP protocol
3753 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3754 loads - load S-Record file over serial line
3755 loadb - load binary file over serial line (kermit mode)
3757 mm - memory modify (auto-incrementing)
3758 nm - memory modify (constant address)
3759 mw - memory write (fill)
3761 cmp - memory compare
3762 crc32 - checksum calculation
3763 i2c - I2C sub-system
3764 sspi - SPI utility commands
3765 base - print or set address offset
3766 printenv- print environment variables
3767 setenv - set environment variables
3768 saveenv - save environment variables to persistent storage
3769 protect - enable or disable FLASH write protection
3770 erase - erase FLASH memory
3771 flinfo - print FLASH memory information
3772 bdinfo - print Board Info structure
3773 iminfo - print header information for application image
3774 coninfo - print console devices and informations
3775 ide - IDE sub-system
3776 loop - infinite loop on address range
3777 loopw - infinite write loop on address range
3778 mtest - simple RAM test
3779 icache - enable or disable instruction cache
3780 dcache - enable or disable data cache
3781 reset - Perform RESET of the CPU
3782 echo - echo args to console
3783 version - print monitor version
3784 help - print online help
3785 ? - alias for 'help'
3788 Monitor Commands - Detailed Description:
3789 ========================================
3793 For now: just type "help <command>".
3796 Environment Variables:
3797 ======================
3799 U-Boot supports user configuration using Environment Variables which
3800 can be made persistent by saving to Flash memory.
3802 Environment Variables are set using "setenv", printed using
3803 "printenv", and saved to Flash using "saveenv". Using "setenv"
3804 without a value can be used to delete a variable from the
3805 environment. As long as you don't save the environment you are
3806 working with an in-memory copy. In case the Flash area containing the
3807 environment is erased by accident, a default environment is provided.
3809 Some configuration options can be set using Environment Variables.
3811 List of environment variables (most likely not complete):
3813 baudrate - see CONFIG_BAUDRATE
3815 bootdelay - see CONFIG_BOOTDELAY
3817 bootcmd - see CONFIG_BOOTCOMMAND
3819 bootargs - Boot arguments when booting an RTOS image
3821 bootfile - Name of the image to load with TFTP
3823 bootm_low - Memory range available for image processing in the bootm
3824 command can be restricted. This variable is given as
3825 a hexadecimal number and defines lowest address allowed
3826 for use by the bootm command. See also "bootm_size"
3827 environment variable. Address defined by "bootm_low" is
3828 also the base of the initial memory mapping for the Linux
3829 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3832 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3833 This variable is given as a hexadecimal number and it
3834 defines the size of the memory region starting at base
3835 address bootm_low that is accessible by the Linux kernel
3836 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3837 as the default value if it is defined, and bootm_size is
3840 bootm_size - Memory range available for image processing in the bootm
3841 command can be restricted. This variable is given as
3842 a hexadecimal number and defines the size of the region
3843 allowed for use by the bootm command. See also "bootm_low"
3844 environment variable.
3846 updatefile - Location of the software update file on a TFTP server, used
3847 by the automatic software update feature. Please refer to
3848 documentation in doc/README.update for more details.
3850 autoload - if set to "no" (any string beginning with 'n'),
3851 "bootp" will just load perform a lookup of the
3852 configuration from the BOOTP server, but not try to
3853 load any image using TFTP
3855 autostart - if set to "yes", an image loaded using the "bootp",
3856 "rarpboot", "tftpboot" or "diskboot" commands will
3857 be automatically started (by internally calling
3860 If set to "no", a standalone image passed to the
3861 "bootm" command will be copied to the load address
3862 (and eventually uncompressed), but NOT be started.
3863 This can be used to load and uncompress arbitrary
3866 fdt_high - if set this restricts the maximum address that the
3867 flattened device tree will be copied into upon boot.
3868 For example, if you have a system with 1 GB memory
3869 at physical address 0x10000000, while Linux kernel
3870 only recognizes the first 704 MB as low memory, you
3871 may need to set fdt_high as 0x3C000000 to have the
3872 device tree blob be copied to the maximum address
3873 of the 704 MB low memory, so that Linux kernel can
3874 access it during the boot procedure.
3876 If this is set to the special value 0xFFFFFFFF then
3877 the fdt will not be copied at all on boot. For this
3878 to work it must reside in writable memory, have
3879 sufficient padding on the end of it for u-boot to
3880 add the information it needs into it, and the memory
3881 must be accessible by the kernel.
3883 fdtcontroladdr- if set this is the address of the control flattened
3884 device tree used by U-Boot when CONFIG_OF_CONTROL is
3887 i2cfast - (PPC405GP|PPC405EP only)
3888 if set to 'y' configures Linux I2C driver for fast
3889 mode (400kHZ). This environment variable is used in
3890 initialization code. So, for changes to be effective
3891 it must be saved and board must be reset.
3893 initrd_high - restrict positioning of initrd images:
3894 If this variable is not set, initrd images will be
3895 copied to the highest possible address in RAM; this
3896 is usually what you want since it allows for
3897 maximum initrd size. If for some reason you want to
3898 make sure that the initrd image is loaded below the
3899 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3900 variable to a value of "no" or "off" or "0".
3901 Alternatively, you can set it to a maximum upper
3902 address to use (U-Boot will still check that it
3903 does not overwrite the U-Boot stack and data).
3905 For instance, when you have a system with 16 MB
3906 RAM, and want to reserve 4 MB from use by Linux,
3907 you can do this by adding "mem=12M" to the value of
3908 the "bootargs" variable. However, now you must make
3909 sure that the initrd image is placed in the first
3910 12 MB as well - this can be done with
3912 setenv initrd_high 00c00000
3914 If you set initrd_high to 0xFFFFFFFF, this is an
3915 indication to U-Boot that all addresses are legal
3916 for the Linux kernel, including addresses in flash
3917 memory. In this case U-Boot will NOT COPY the
3918 ramdisk at all. This may be useful to reduce the
3919 boot time on your system, but requires that this
3920 feature is supported by your Linux kernel.
3922 ipaddr - IP address; needed for tftpboot command
3924 loadaddr - Default load address for commands like "bootp",
3925 "rarpboot", "tftpboot", "loadb" or "diskboot"
3927 loads_echo - see CONFIG_LOADS_ECHO
3929 serverip - TFTP server IP address; needed for tftpboot command
3931 bootretry - see CONFIG_BOOT_RETRY_TIME
3933 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3935 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3937 ethprime - controls which interface is used first.
3939 ethact - controls which interface is currently active.
3940 For example you can do the following
3942 => setenv ethact FEC
3943 => ping 192.168.0.1 # traffic sent on FEC
3944 => setenv ethact SCC
3945 => ping 10.0.0.1 # traffic sent on SCC
3947 ethrotate - When set to "no" U-Boot does not go through all
3948 available network interfaces.
3949 It just stays at the currently selected interface.
3951 netretry - When set to "no" each network operation will
3952 either succeed or fail without retrying.
3953 When set to "once" the network operation will
3954 fail when all the available network interfaces
3955 are tried once without success.
3956 Useful on scripts which control the retry operation
3959 npe_ucode - set load address for the NPE microcode
3961 tftpsrcport - If this is set, the value is used for TFTP's
3964 tftpdstport - If this is set, the value is used for TFTP's UDP
3965 destination port instead of the Well Know Port 69.
3967 tftpblocksize - Block size to use for TFTP transfers; if not set,
3968 we use the TFTP server's default block size
3970 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3971 seconds, minimum value is 1000 = 1 second). Defines
3972 when a packet is considered to be lost so it has to
3973 be retransmitted. The default is 5000 = 5 seconds.
3974 Lowering this value may make downloads succeed
3975 faster in networks with high packet loss rates or
3976 with unreliable TFTP servers.
3978 vlan - When set to a value < 4095 the traffic over
3979 Ethernet is encapsulated/received over 802.1q
3982 The following image location variables contain the location of images
3983 used in booting. The "Image" column gives the role of the image and is
3984 not an environment variable name. The other columns are environment
3985 variable names. "File Name" gives the name of the file on a TFTP
3986 server, "RAM Address" gives the location in RAM the image will be
3987 loaded to, and "Flash Location" gives the image's address in NOR
3988 flash or offset in NAND flash.
3990 *Note* - these variables don't have to be defined for all boards, some
3991 boards currenlty use other variables for these purposes, and some
3992 boards use these variables for other purposes.
3994 Image File Name RAM Address Flash Location
3995 ----- --------- ----------- --------------
3996 u-boot u-boot u-boot_addr_r u-boot_addr
3997 Linux kernel bootfile kernel_addr_r kernel_addr
3998 device tree blob fdtfile fdt_addr_r fdt_addr
3999 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4001 The following environment variables may be used and automatically
4002 updated by the network boot commands ("bootp" and "rarpboot"),
4003 depending the information provided by your boot server:
4005 bootfile - see above
4006 dnsip - IP address of your Domain Name Server
4007 dnsip2 - IP address of your secondary Domain Name Server
4008 gatewayip - IP address of the Gateway (Router) to use
4009 hostname - Target hostname
4011 netmask - Subnet Mask
4012 rootpath - Pathname of the root filesystem on the NFS server
4013 serverip - see above
4016 There are two special Environment Variables:
4018 serial# - contains hardware identification information such
4019 as type string and/or serial number
4020 ethaddr - Ethernet address
4022 These variables can be set only once (usually during manufacturing of
4023 the board). U-Boot refuses to delete or overwrite these variables
4024 once they have been set once.
4027 Further special Environment Variables:
4029 ver - Contains the U-Boot version string as printed
4030 with the "version" command. This variable is
4031 readonly (see CONFIG_VERSION_VARIABLE).
4034 Please note that changes to some configuration parameters may take
4035 only effect after the next boot (yes, that's just like Windoze :-).
4038 Command Line Parsing:
4039 =====================
4041 There are two different command line parsers available with U-Boot:
4042 the old "simple" one, and the much more powerful "hush" shell:
4044 Old, simple command line parser:
4045 --------------------------------
4047 - supports environment variables (through setenv / saveenv commands)
4048 - several commands on one line, separated by ';'
4049 - variable substitution using "... ${name} ..." syntax
4050 - special characters ('$', ';') can be escaped by prefixing with '\',
4052 setenv bootcmd bootm \${address}
4053 - You can also escape text by enclosing in single apostrophes, for example:
4054 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4059 - similar to Bourne shell, with control structures like
4060 if...then...else...fi, for...do...done; while...do...done,
4061 until...do...done, ...
4062 - supports environment ("global") variables (through setenv / saveenv
4063 commands) and local shell variables (through standard shell syntax
4064 "name=value"); only environment variables can be used with "run"
4070 (1) If a command line (or an environment variable executed by a "run"
4071 command) contains several commands separated by semicolon, and
4072 one of these commands fails, then the remaining commands will be
4075 (2) If you execute several variables with one call to run (i. e.
4076 calling run with a list of variables as arguments), any failing
4077 command will cause "run" to terminate, i. e. the remaining
4078 variables are not executed.
4080 Note for Redundant Ethernet Interfaces:
4081 =======================================
4083 Some boards come with redundant Ethernet interfaces; U-Boot supports
4084 such configurations and is capable of automatic selection of a
4085 "working" interface when needed. MAC assignment works as follows:
4087 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4088 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4089 "eth1addr" (=>eth1), "eth2addr", ...
4091 If the network interface stores some valid MAC address (for instance
4092 in SROM), this is used as default address if there is NO correspon-
4093 ding setting in the environment; if the corresponding environment
4094 variable is set, this overrides the settings in the card; that means:
4096 o If the SROM has a valid MAC address, and there is no address in the
4097 environment, the SROM's address is used.
4099 o If there is no valid address in the SROM, and a definition in the
4100 environment exists, then the value from the environment variable is
4103 o If both the SROM and the environment contain a MAC address, and
4104 both addresses are the same, this MAC address is used.
4106 o If both the SROM and the environment contain a MAC address, and the
4107 addresses differ, the value from the environment is used and a
4110 o If neither SROM nor the environment contain a MAC address, an error
4113 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4114 will be programmed into hardware as part of the initialization process. This
4115 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4116 The naming convention is as follows:
4117 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4122 U-Boot is capable of booting (and performing other auxiliary operations on)
4123 images in two formats:
4125 New uImage format (FIT)
4126 -----------------------
4128 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4129 to Flattened Device Tree). It allows the use of images with multiple
4130 components (several kernels, ramdisks, etc.), with contents protected by
4131 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4137 Old image format is based on binary files which can be basically anything,
4138 preceded by a special header; see the definitions in include/image.h for
4139 details; basically, the header defines the following image properties:
4141 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4142 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4143 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4144 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4146 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4147 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4148 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4149 * Compression Type (uncompressed, gzip, bzip2)
4155 The header is marked by a special Magic Number, and both the header
4156 and the data portions of the image are secured against corruption by
4163 Although U-Boot should support any OS or standalone application
4164 easily, the main focus has always been on Linux during the design of
4167 U-Boot includes many features that so far have been part of some
4168 special "boot loader" code within the Linux kernel. Also, any
4169 "initrd" images to be used are no longer part of one big Linux image;
4170 instead, kernel and "initrd" are separate images. This implementation
4171 serves several purposes:
4173 - the same features can be used for other OS or standalone
4174 applications (for instance: using compressed images to reduce the
4175 Flash memory footprint)
4177 - it becomes much easier to port new Linux kernel versions because
4178 lots of low-level, hardware dependent stuff are done by U-Boot
4180 - the same Linux kernel image can now be used with different "initrd"
4181 images; of course this also means that different kernel images can
4182 be run with the same "initrd". This makes testing easier (you don't
4183 have to build a new "zImage.initrd" Linux image when you just
4184 change a file in your "initrd"). Also, a field-upgrade of the
4185 software is easier now.
4191 Porting Linux to U-Boot based systems:
4192 ---------------------------------------
4194 U-Boot cannot save you from doing all the necessary modifications to
4195 configure the Linux device drivers for use with your target hardware
4196 (no, we don't intend to provide a full virtual machine interface to
4199 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4201 Just make sure your machine specific header file (for instance
4202 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4203 Information structure as we define in include/asm-<arch>/u-boot.h,
4204 and make sure that your definition of IMAP_ADDR uses the same value
4205 as your U-Boot configuration in CONFIG_SYS_IMMR.
4208 Configuring the Linux kernel:
4209 -----------------------------
4211 No specific requirements for U-Boot. Make sure you have some root
4212 device (initial ramdisk, NFS) for your target system.
4215 Building a Linux Image:
4216 -----------------------
4218 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4219 not used. If you use recent kernel source, a new build target
4220 "uImage" will exist which automatically builds an image usable by
4221 U-Boot. Most older kernels also have support for a "pImage" target,
4222 which was introduced for our predecessor project PPCBoot and uses a
4223 100% compatible format.
4232 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4233 encapsulate a compressed Linux kernel image with header information,
4234 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4236 * build a standard "vmlinux" kernel image (in ELF binary format):
4238 * convert the kernel into a raw binary image:
4240 ${CROSS_COMPILE}-objcopy -O binary \
4241 -R .note -R .comment \
4242 -S vmlinux linux.bin
4244 * compress the binary image:
4248 * package compressed binary image for U-Boot:
4250 mkimage -A ppc -O linux -T kernel -C gzip \
4251 -a 0 -e 0 -n "Linux Kernel Image" \
4252 -d linux.bin.gz uImage
4255 The "mkimage" tool can also be used to create ramdisk images for use
4256 with U-Boot, either separated from the Linux kernel image, or
4257 combined into one file. "mkimage" encapsulates the images with a 64
4258 byte header containing information about target architecture,
4259 operating system, image type, compression method, entry points, time
4260 stamp, CRC32 checksums, etc.
4262 "mkimage" can be called in two ways: to verify existing images and
4263 print the header information, or to build new images.
4265 In the first form (with "-l" option) mkimage lists the information
4266 contained in the header of an existing U-Boot image; this includes
4267 checksum verification:
4269 tools/mkimage -l image
4270 -l ==> list image header information
4272 The second form (with "-d" option) is used to build a U-Boot image
4273 from a "data file" which is used as image payload:
4275 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4276 -n name -d data_file image
4277 -A ==> set architecture to 'arch'
4278 -O ==> set operating system to 'os'
4279 -T ==> set image type to 'type'
4280 -C ==> set compression type 'comp'
4281 -a ==> set load address to 'addr' (hex)
4282 -e ==> set entry point to 'ep' (hex)
4283 -n ==> set image name to 'name'
4284 -d ==> use image data from 'datafile'
4286 Right now, all Linux kernels for PowerPC systems use the same load
4287 address (0x00000000), but the entry point address depends on the
4290 - 2.2.x kernels have the entry point at 0x0000000C,
4291 - 2.3.x and later kernels have the entry point at 0x00000000.
4293 So a typical call to build a U-Boot image would read:
4295 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4296 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4297 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4298 > examples/uImage.TQM850L
4299 Image Name: 2.4.4 kernel for TQM850L
4300 Created: Wed Jul 19 02:34:59 2000
4301 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4302 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4303 Load Address: 0x00000000
4304 Entry Point: 0x00000000
4306 To verify the contents of the image (or check for corruption):
4308 -> tools/mkimage -l examples/uImage.TQM850L
4309 Image Name: 2.4.4 kernel for TQM850L
4310 Created: Wed Jul 19 02:34:59 2000
4311 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4312 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4313 Load Address: 0x00000000
4314 Entry Point: 0x00000000
4316 NOTE: for embedded systems where boot time is critical you can trade
4317 speed for memory and install an UNCOMPRESSED image instead: this
4318 needs more space in Flash, but boots much faster since it does not
4319 need to be uncompressed:
4321 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4322 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4323 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4324 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4325 > examples/uImage.TQM850L-uncompressed
4326 Image Name: 2.4.4 kernel for TQM850L
4327 Created: Wed Jul 19 02:34:59 2000
4328 Image Type: PowerPC Linux Kernel Image (uncompressed)
4329 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4330 Load Address: 0x00000000
4331 Entry Point: 0x00000000
4334 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4335 when your kernel is intended to use an initial ramdisk:
4337 -> tools/mkimage -n 'Simple Ramdisk Image' \
4338 > -A ppc -O linux -T ramdisk -C gzip \
4339 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4340 Image Name: Simple Ramdisk Image
4341 Created: Wed Jan 12 14:01:50 2000
4342 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4343 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4344 Load Address: 0x00000000
4345 Entry Point: 0x00000000
4348 Installing a Linux Image:
4349 -------------------------
4351 To downloading a U-Boot image over the serial (console) interface,
4352 you must convert the image to S-Record format:
4354 objcopy -I binary -O srec examples/image examples/image.srec
4356 The 'objcopy' does not understand the information in the U-Boot
4357 image header, so the resulting S-Record file will be relative to
4358 address 0x00000000. To load it to a given address, you need to
4359 specify the target address as 'offset' parameter with the 'loads'
4362 Example: install the image to address 0x40100000 (which on the
4363 TQM8xxL is in the first Flash bank):
4365 => erase 40100000 401FFFFF
4371 ## Ready for S-Record download ...
4372 ~>examples/image.srec
4373 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4375 15989 15990 15991 15992
4376 [file transfer complete]
4378 ## Start Addr = 0x00000000
4381 You can check the success of the download using the 'iminfo' command;
4382 this includes a checksum verification so you can be sure no data
4383 corruption happened:
4387 ## Checking Image at 40100000 ...
4388 Image Name: 2.2.13 for initrd on TQM850L
4389 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4390 Data Size: 335725 Bytes = 327 kB = 0 MB
4391 Load Address: 00000000
4392 Entry Point: 0000000c
4393 Verifying Checksum ... OK
4399 The "bootm" command is used to boot an application that is stored in
4400 memory (RAM or Flash). In case of a Linux kernel image, the contents
4401 of the "bootargs" environment variable is passed to the kernel as
4402 parameters. You can check and modify this variable using the
4403 "printenv" and "setenv" commands:
4406 => printenv bootargs
4407 bootargs=root=/dev/ram
4409 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4411 => printenv bootargs
4412 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4415 ## Booting Linux kernel at 40020000 ...
4416 Image Name: 2.2.13 for NFS on TQM850L
4417 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4418 Data Size: 381681 Bytes = 372 kB = 0 MB
4419 Load Address: 00000000
4420 Entry Point: 0000000c
4421 Verifying Checksum ... OK
4422 Uncompressing Kernel Image ... OK
4423 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
4424 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4425 time_init: decrementer frequency = 187500000/60
4426 Calibrating delay loop... 49.77 BogoMIPS
4427 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4430 If you want to boot a Linux kernel with initial RAM disk, you pass
4431 the memory addresses of both the kernel and the initrd image (PPBCOOT
4432 format!) to the "bootm" command:
4434 => imi 40100000 40200000
4436 ## Checking Image at 40100000 ...
4437 Image Name: 2.2.13 for initrd on TQM850L
4438 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4439 Data Size: 335725 Bytes = 327 kB = 0 MB
4440 Load Address: 00000000
4441 Entry Point: 0000000c
4442 Verifying Checksum ... OK
4444 ## Checking Image at 40200000 ...
4445 Image Name: Simple Ramdisk Image
4446 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4447 Data Size: 566530 Bytes = 553 kB = 0 MB
4448 Load Address: 00000000
4449 Entry Point: 00000000
4450 Verifying Checksum ... OK
4452 => bootm 40100000 40200000
4453 ## Booting Linux kernel at 40100000 ...
4454 Image Name: 2.2.13 for initrd on TQM850L
4455 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4456 Data Size: 335725 Bytes = 327 kB = 0 MB
4457 Load Address: 00000000
4458 Entry Point: 0000000c
4459 Verifying Checksum ... OK
4460 Uncompressing Kernel Image ... OK
4461 ## Loading RAMDisk Image at 40200000 ...
4462 Image Name: Simple Ramdisk Image
4463 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4464 Data Size: 566530 Bytes = 553 kB = 0 MB
4465 Load Address: 00000000
4466 Entry Point: 00000000
4467 Verifying Checksum ... OK
4468 Loading Ramdisk ... OK
4469 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
4470 Boot arguments: root=/dev/ram
4471 time_init: decrementer frequency = 187500000/60
4472 Calibrating delay loop... 49.77 BogoMIPS
4474 RAMDISK: Compressed image found at block 0
4475 VFS: Mounted root (ext2 filesystem).
4479 Boot Linux and pass a flat device tree:
4482 First, U-Boot must be compiled with the appropriate defines. See the section
4483 titled "Linux Kernel Interface" above for a more in depth explanation. The
4484 following is an example of how to start a kernel and pass an updated
4490 oft=oftrees/mpc8540ads.dtb
4491 => tftp $oftaddr $oft
4492 Speed: 1000, full duplex
4494 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4495 Filename 'oftrees/mpc8540ads.dtb'.
4496 Load address: 0x300000
4499 Bytes transferred = 4106 (100a hex)
4500 => tftp $loadaddr $bootfile
4501 Speed: 1000, full duplex
4503 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4505 Load address: 0x200000
4506 Loading:############
4508 Bytes transferred = 1029407 (fb51f hex)
4513 => bootm $loadaddr - $oftaddr
4514 ## Booting image at 00200000 ...
4515 Image Name: Linux-2.6.17-dirty
4516 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4517 Data Size: 1029343 Bytes = 1005.2 kB
4518 Load Address: 00000000
4519 Entry Point: 00000000
4520 Verifying Checksum ... OK
4521 Uncompressing Kernel Image ... OK
4522 Booting using flat device tree at 0x300000
4523 Using MPC85xx ADS machine description
4524 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4528 More About U-Boot Image Types:
4529 ------------------------------
4531 U-Boot supports the following image types:
4533 "Standalone Programs" are directly runnable in the environment
4534 provided by U-Boot; it is expected that (if they behave
4535 well) you can continue to work in U-Boot after return from
4536 the Standalone Program.
4537 "OS Kernel Images" are usually images of some Embedded OS which
4538 will take over control completely. Usually these programs
4539 will install their own set of exception handlers, device
4540 drivers, set up the MMU, etc. - this means, that you cannot
4541 expect to re-enter U-Boot except by resetting the CPU.
4542 "RAMDisk Images" are more or less just data blocks, and their
4543 parameters (address, size) are passed to an OS kernel that is
4545 "Multi-File Images" contain several images, typically an OS
4546 (Linux) kernel image and one or more data images like
4547 RAMDisks. This construct is useful for instance when you want
4548 to boot over the network using BOOTP etc., where the boot
4549 server provides just a single image file, but you want to get
4550 for instance an OS kernel and a RAMDisk image.
4552 "Multi-File Images" start with a list of image sizes, each
4553 image size (in bytes) specified by an "uint32_t" in network
4554 byte order. This list is terminated by an "(uint32_t)0".
4555 Immediately after the terminating 0 follow the images, one by
4556 one, all aligned on "uint32_t" boundaries (size rounded up to
4557 a multiple of 4 bytes).
4559 "Firmware Images" are binary images containing firmware (like
4560 U-Boot or FPGA images) which usually will be programmed to
4563 "Script files" are command sequences that will be executed by
4564 U-Boot's command interpreter; this feature is especially
4565 useful when you configure U-Boot to use a real shell (hush)
4566 as command interpreter.
4568 Booting the Linux zImage:
4569 -------------------------
4571 On some platforms, it's possible to boot Linux zImage. This is done
4572 using the "bootz" command. The syntax of "bootz" command is the same
4573 as the syntax of "bootm" command.
4575 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4576 kernel with raw initrd images. The syntax is slightly different, the
4577 address of the initrd must be augmented by it's size, in the following
4578 format: "<initrd addres>:<initrd size>".
4584 One of the features of U-Boot is that you can dynamically load and
4585 run "standalone" applications, which can use some resources of
4586 U-Boot like console I/O functions or interrupt services.
4588 Two simple examples are included with the sources:
4593 'examples/hello_world.c' contains a small "Hello World" Demo
4594 application; it is automatically compiled when you build U-Boot.
4595 It's configured to run at address 0x00040004, so you can play with it
4599 ## Ready for S-Record download ...
4600 ~>examples/hello_world.srec
4601 1 2 3 4 5 6 7 8 9 10 11 ...
4602 [file transfer complete]
4604 ## Start Addr = 0x00040004
4606 => go 40004 Hello World! This is a test.
4607 ## Starting application at 0x00040004 ...
4618 Hit any key to exit ...
4620 ## Application terminated, rc = 0x0
4622 Another example, which demonstrates how to register a CPM interrupt
4623 handler with the U-Boot code, can be found in 'examples/timer.c'.
4624 Here, a CPM timer is set up to generate an interrupt every second.
4625 The interrupt service routine is trivial, just printing a '.'
4626 character, but this is just a demo program. The application can be
4627 controlled by the following keys:
4629 ? - print current values og the CPM Timer registers
4630 b - enable interrupts and start timer
4631 e - stop timer and disable interrupts
4632 q - quit application
4635 ## Ready for S-Record download ...
4636 ~>examples/timer.srec
4637 1 2 3 4 5 6 7 8 9 10 11 ...
4638 [file transfer complete]
4640 ## Start Addr = 0x00040004
4643 ## Starting application at 0x00040004 ...
4646 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4649 [q, b, e, ?] Set interval 1000000 us
4652 [q, b, e, ?] ........
4653 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4656 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4659 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4662 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4664 [q, b, e, ?] ...Stopping timer
4666 [q, b, e, ?] ## Application terminated, rc = 0x0
4672 Over time, many people have reported problems when trying to use the
4673 "minicom" terminal emulation program for serial download. I (wd)
4674 consider minicom to be broken, and recommend not to use it. Under
4675 Unix, I recommend to use C-Kermit for general purpose use (and
4676 especially for kermit binary protocol download ("loadb" command), and
4677 use "cu" for S-Record download ("loads" command).
4679 Nevertheless, if you absolutely want to use it try adding this
4680 configuration to your "File transfer protocols" section:
4682 Name Program Name U/D FullScr IO-Red. Multi
4683 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4684 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4690 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4691 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4693 Building requires a cross environment; it is known to work on
4694 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4695 need gmake since the Makefiles are not compatible with BSD make).
4696 Note that the cross-powerpc package does not install include files;
4697 attempting to build U-Boot will fail because <machine/ansi.h> is
4698 missing. This file has to be installed and patched manually:
4700 # cd /usr/pkg/cross/powerpc-netbsd/include
4702 # ln -s powerpc machine
4703 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4704 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4706 Native builds *don't* work due to incompatibilities between native
4707 and U-Boot include files.
4709 Booting assumes that (the first part of) the image booted is a
4710 stage-2 loader which in turn loads and then invokes the kernel
4711 proper. Loader sources will eventually appear in the NetBSD source
4712 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4713 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4716 Implementation Internals:
4717 =========================
4719 The following is not intended to be a complete description of every
4720 implementation detail. However, it should help to understand the
4721 inner workings of U-Boot and make it easier to port it to custom
4725 Initial Stack, Global Data:
4726 ---------------------------
4728 The implementation of U-Boot is complicated by the fact that U-Boot
4729 starts running out of ROM (flash memory), usually without access to
4730 system RAM (because the memory controller is not initialized yet).
4731 This means that we don't have writable Data or BSS segments, and BSS
4732 is not initialized as zero. To be able to get a C environment working
4733 at all, we have to allocate at least a minimal stack. Implementation
4734 options for this are defined and restricted by the CPU used: Some CPU
4735 models provide on-chip memory (like the IMMR area on MPC8xx and
4736 MPC826x processors), on others (parts of) the data cache can be
4737 locked as (mis-) used as memory, etc.
4739 Chris Hallinan posted a good summary of these issues to the
4740 U-Boot mailing list:
4742 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4743 From: "Chris Hallinan" <clh@net1plus.com>
4744 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4747 Correct me if I'm wrong, folks, but the way I understand it
4748 is this: Using DCACHE as initial RAM for Stack, etc, does not
4749 require any physical RAM backing up the cache. The cleverness
4750 is that the cache is being used as a temporary supply of
4751 necessary storage before the SDRAM controller is setup. It's
4752 beyond the scope of this list to explain the details, but you
4753 can see how this works by studying the cache architecture and
4754 operation in the architecture and processor-specific manuals.
4756 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4757 is another option for the system designer to use as an
4758 initial stack/RAM area prior to SDRAM being available. Either
4759 option should work for you. Using CS 4 should be fine if your
4760 board designers haven't used it for something that would
4761 cause you grief during the initial boot! It is frequently not
4764 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4765 with your processor/board/system design. The default value
4766 you will find in any recent u-boot distribution in
4767 walnut.h should work for you. I'd set it to a value larger
4768 than your SDRAM module. If you have a 64MB SDRAM module, set
4769 it above 400_0000. Just make sure your board has no resources
4770 that are supposed to respond to that address! That code in
4771 start.S has been around a while and should work as is when
4772 you get the config right.
4777 It is essential to remember this, since it has some impact on the C
4778 code for the initialization procedures:
4780 * Initialized global data (data segment) is read-only. Do not attempt
4783 * Do not use any uninitialized global data (or implicitely initialized
4784 as zero data - BSS segment) at all - this is undefined, initiali-
4785 zation is performed later (when relocating to RAM).
4787 * Stack space is very limited. Avoid big data buffers or things like
4790 Having only the stack as writable memory limits means we cannot use
4791 normal global data to share information beween the code. But it
4792 turned out that the implementation of U-Boot can be greatly
4793 simplified by making a global data structure (gd_t) available to all
4794 functions. We could pass a pointer to this data as argument to _all_
4795 functions, but this would bloat the code. Instead we use a feature of
4796 the GCC compiler (Global Register Variables) to share the data: we
4797 place a pointer (gd) to the global data into a register which we
4798 reserve for this purpose.
4800 When choosing a register for such a purpose we are restricted by the
4801 relevant (E)ABI specifications for the current architecture, and by
4802 GCC's implementation.
4804 For PowerPC, the following registers have specific use:
4806 R2: reserved for system use
4807 R3-R4: parameter passing and return values
4808 R5-R10: parameter passing
4809 R13: small data area pointer
4813 (U-Boot also uses R12 as internal GOT pointer. r12
4814 is a volatile register so r12 needs to be reset when
4815 going back and forth between asm and C)
4817 ==> U-Boot will use R2 to hold a pointer to the global data
4819 Note: on PPC, we could use a static initializer (since the
4820 address of the global data structure is known at compile time),
4821 but it turned out that reserving a register results in somewhat
4822 smaller code - although the code savings are not that big (on
4823 average for all boards 752 bytes for the whole U-Boot image,
4824 624 text + 127 data).
4826 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4827 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4829 ==> U-Boot will use P3 to hold a pointer to the global data
4831 On ARM, the following registers are used:
4833 R0: function argument word/integer result
4834 R1-R3: function argument word
4836 R10: stack limit (used only if stack checking if enabled)
4837 R11: argument (frame) pointer
4838 R12: temporary workspace
4841 R15: program counter
4843 ==> U-Boot will use R8 to hold a pointer to the global data
4845 On Nios II, the ABI is documented here:
4846 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4848 ==> U-Boot will use gp to hold a pointer to the global data
4850 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4851 to access small data sections, so gp is free.
4853 On NDS32, the following registers are used:
4855 R0-R1: argument/return
4857 R15: temporary register for assembler
4858 R16: trampoline register
4859 R28: frame pointer (FP)
4860 R29: global pointer (GP)
4861 R30: link register (LP)
4862 R31: stack pointer (SP)
4863 PC: program counter (PC)
4865 ==> U-Boot will use R10 to hold a pointer to the global data
4867 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4868 or current versions of GCC may "optimize" the code too much.
4873 U-Boot runs in system state and uses physical addresses, i.e. the
4874 MMU is not used either for address mapping nor for memory protection.
4876 The available memory is mapped to fixed addresses using the memory
4877 controller. In this process, a contiguous block is formed for each
4878 memory type (Flash, SDRAM, SRAM), even when it consists of several
4879 physical memory banks.
4881 U-Boot is installed in the first 128 kB of the first Flash bank (on
4882 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4883 booting and sizing and initializing DRAM, the code relocates itself
4884 to the upper end of DRAM. Immediately below the U-Boot code some
4885 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4886 configuration setting]. Below that, a structure with global Board
4887 Info data is placed, followed by the stack (growing downward).
4889 Additionally, some exception handler code is copied to the low 8 kB
4890 of DRAM (0x00000000 ... 0x00001FFF).
4892 So a typical memory configuration with 16 MB of DRAM could look like
4895 0x0000 0000 Exception Vector code
4898 0x0000 2000 Free for Application Use
4904 0x00FB FF20 Monitor Stack (Growing downward)
4905 0x00FB FFAC Board Info Data and permanent copy of global data
4906 0x00FC 0000 Malloc Arena
4909 0x00FE 0000 RAM Copy of Monitor Code
4910 ... eventually: LCD or video framebuffer
4911 ... eventually: pRAM (Protected RAM - unchanged by reset)
4912 0x00FF FFFF [End of RAM]
4915 System Initialization:
4916 ----------------------
4918 In the reset configuration, U-Boot starts at the reset entry point
4919 (on most PowerPC systems at address 0x00000100). Because of the reset
4920 configuration for CS0# this is a mirror of the onboard Flash memory.
4921 To be able to re-map memory U-Boot then jumps to its link address.
4922 To be able to implement the initialization code in C, a (small!)
4923 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4924 which provide such a feature like MPC8xx or MPC8260), or in a locked
4925 part of the data cache. After that, U-Boot initializes the CPU core,
4926 the caches and the SIU.
4928 Next, all (potentially) available memory banks are mapped using a
4929 preliminary mapping. For example, we put them on 512 MB boundaries
4930 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4931 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4932 programmed for SDRAM access. Using the temporary configuration, a
4933 simple memory test is run that determines the size of the SDRAM
4936 When there is more than one SDRAM bank, and the banks are of
4937 different size, the largest is mapped first. For equal size, the first
4938 bank (CS2#) is mapped first. The first mapping is always for address
4939 0x00000000, with any additional banks following immediately to create
4940 contiguous memory starting from 0.
4942 Then, the monitor installs itself at the upper end of the SDRAM area
4943 and allocates memory for use by malloc() and for the global Board
4944 Info data; also, the exception vector code is copied to the low RAM
4945 pages, and the final stack is set up.
4947 Only after this relocation will you have a "normal" C environment;
4948 until that you are restricted in several ways, mostly because you are
4949 running from ROM, and because the code will have to be relocated to a
4953 U-Boot Porting Guide:
4954 ----------------------
4956 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4960 int main(int argc, char *argv[])
4962 sighandler_t no_more_time;
4964 signal(SIGALRM, no_more_time);
4965 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4967 if (available_money > available_manpower) {
4968 Pay consultant to port U-Boot;
4972 Download latest U-Boot source;
4974 Subscribe to u-boot mailing list;
4977 email("Hi, I am new to U-Boot, how do I get started?");
4980 Read the README file in the top level directory;
4981 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4982 Read applicable doc/*.README;
4983 Read the source, Luke;
4984 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4987 if (available_money > toLocalCurrency ($2500))
4990 Add a lot of aggravation and time;
4992 if (a similar board exists) { /* hopefully... */
4993 cp -a board/<similar> board/<myboard>
4994 cp include/configs/<similar>.h include/configs/<myboard>.h
4996 Create your own board support subdirectory;
4997 Create your own board include/configs/<myboard>.h file;
4999 Edit new board/<myboard> files
5000 Edit new include/configs/<myboard>.h
5005 Add / modify source code;
5009 email("Hi, I am having problems...");
5011 Send patch file to the U-Boot email list;
5012 if (reasonable critiques)
5013 Incorporate improvements from email list code review;
5015 Defend code as written;
5021 void no_more_time (int sig)
5030 All contributions to U-Boot should conform to the Linux kernel
5031 coding style; see the file "Documentation/CodingStyle" and the script
5032 "scripts/Lindent" in your Linux kernel source directory.
5034 Source files originating from a different project (for example the
5035 MTD subsystem) are generally exempt from these guidelines and are not
5036 reformated to ease subsequent migration to newer versions of those
5039 Please note that U-Boot is implemented in C (and to some small parts in
5040 Assembler); no C++ is used, so please do not use C++ style comments (//)
5043 Please also stick to the following formatting rules:
5044 - remove any trailing white space
5045 - use TAB characters for indentation and vertical alignment, not spaces
5046 - make sure NOT to use DOS '\r\n' line feeds
5047 - do not add more than 2 consecutive empty lines to source files
5048 - do not add trailing empty lines to source files
5050 Submissions which do not conform to the standards may be returned
5051 with a request to reformat the changes.
5057 Since the number of patches for U-Boot is growing, we need to
5058 establish some rules. Submissions which do not conform to these rules
5059 may be rejected, even when they contain important and valuable stuff.
5061 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5063 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5064 see http://lists.denx.de/mailman/listinfo/u-boot
5066 When you send a patch, please include the following information with
5069 * For bug fixes: a description of the bug and how your patch fixes
5070 this bug. Please try to include a way of demonstrating that the
5071 patch actually fixes something.
5073 * For new features: a description of the feature and your
5076 * A CHANGELOG entry as plaintext (separate from the patch)
5078 * For major contributions, your entry to the CREDITS file
5080 * When you add support for a new board, don't forget to add this
5081 board to the MAINTAINERS file, too.
5083 * If your patch adds new configuration options, don't forget to
5084 document these in the README file.
5086 * The patch itself. If you are using git (which is *strongly*
5087 recommended) you can easily generate the patch using the
5088 "git format-patch". If you then use "git send-email" to send it to
5089 the U-Boot mailing list, you will avoid most of the common problems
5090 with some other mail clients.
5092 If you cannot use git, use "diff -purN OLD NEW". If your version of
5093 diff does not support these options, then get the latest version of
5096 The current directory when running this command shall be the parent
5097 directory of the U-Boot source tree (i. e. please make sure that
5098 your patch includes sufficient directory information for the
5101 We prefer patches as plain text. MIME attachments are discouraged,
5102 and compressed attachments must not be used.
5104 * If one logical set of modifications affects or creates several
5105 files, all these changes shall be submitted in a SINGLE patch file.
5107 * Changesets that contain different, unrelated modifications shall be
5108 submitted as SEPARATE patches, one patch per changeset.
5113 * Before sending the patch, run the MAKEALL script on your patched
5114 source tree and make sure that no errors or warnings are reported
5115 for any of the boards.
5117 * Keep your modifications to the necessary minimum: A patch
5118 containing several unrelated changes or arbitrary reformats will be
5119 returned with a request to re-formatting / split it.
5121 * If you modify existing code, make sure that your new code does not
5122 add to the memory footprint of the code ;-) Small is beautiful!
5123 When adding new features, these should compile conditionally only
5124 (using #ifdef), and the resulting code with the new feature
5125 disabled must not need more memory than the old code without your
5128 * Remember that there is a size limit of 100 kB per message on the
5129 u-boot mailing list. Bigger patches will be moderated. If they are
5130 reasonable and not too big, they will be acknowledged. But patches
5131 bigger than the size limit should be avoided.