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.
368 Specifies that the core is a 64-bit PowerPC implementation (implements
369 the "64" category of the Power ISA). This is necessary for ePAPR
370 compliance, among other possible reasons.
372 CONFIG_SYS_FSL_TBCLK_DIV
374 Defines the core time base clock divider ratio compared to the
375 system clock. On most PQ3 devices this is 8, on newer QorIQ
376 devices it can be 16 or 32. The ratio varies from SoC to Soc.
378 CONFIG_SYS_FSL_PCIE_COMPAT
380 Defines the string to utilize when trying to match PCIe device
381 tree nodes for the given platform.
383 CONFIG_SYS_PPC_E500_DEBUG_TLB
385 Enables a temporary TLB entry to be used during boot to work
386 around limitations in e500v1 and e500v2 external debugger
387 support. This reduces the portions of the boot code where
388 breakpoints and single stepping do not work. The value of this
389 symbol should be set to the TLB1 entry to be used for this
392 CONFIG_SYS_FSL_ERRATUM_A004510
394 Enables a workaround for erratum A004510. If set,
395 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
396 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
398 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
399 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
401 Defines one or two SoC revisions (low 8 bits of SVR)
402 for which the A004510 workaround should be applied.
404 The rest of SVR is either not relevant to the decision
405 of whether the erratum is present (e.g. p2040 versus
406 p2041) or is implied by the build target, which controls
407 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
409 See Freescale App Note 4493 for more information about
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 - Generic CPU options:
418 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
420 Defines the endianess of the CPU. Implementation of those
421 values is arch specific.
423 - Intel Monahans options:
424 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
426 Defines the Monahans run mode to oscillator
427 ratio. Valid values are 8, 16, 24, 31. The core
428 frequency is this value multiplied by 13 MHz.
430 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
432 Defines the Monahans turbo mode to oscillator
433 ratio. Valid values are 1 (default if undefined) and
434 2. The core frequency as calculated above is multiplied
438 CONFIG_SYS_INIT_SP_OFFSET
440 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
441 pointer. This is needed for the temporary stack before
444 CONFIG_SYS_MIPS_CACHE_MODE
446 Cache operation mode for the MIPS CPU.
447 See also arch/mips/include/asm/mipsregs.h.
449 CONF_CM_CACHABLE_NO_WA
452 CONF_CM_CACHABLE_NONCOHERENT
456 CONF_CM_CACHABLE_ACCELERATED
458 CONFIG_SYS_XWAY_EBU_BOOTCFG
460 Special option for Lantiq XWAY SoCs for booting from NOR flash.
461 See also arch/mips/cpu/mips32/start.S.
463 CONFIG_XWAY_SWAP_BYTES
465 Enable compilation of tools/xway-swap-bytes needed for Lantiq
466 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
467 be swapped if a flash programmer is used.
470 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
472 Select high exception vectors of the ARM core, e.g., do not
473 clear the V bit of the c1 register of CP15.
475 CONFIG_SYS_THUMB_BUILD
477 Use this flag to build U-Boot using the Thumb instruction
478 set for ARM architectures. Thumb instruction set provides
479 better code density. For ARM architectures that support
480 Thumb2 this flag will result in Thumb2 code generated by
483 - Linux Kernel Interface:
486 U-Boot stores all clock information in Hz
487 internally. For binary compatibility with older Linux
488 kernels (which expect the clocks passed in the
489 bd_info data to be in MHz) the environment variable
490 "clocks_in_mhz" can be defined so that U-Boot
491 converts clock data to MHZ before passing it to the
493 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
494 "clocks_in_mhz=1" is automatically included in the
497 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
499 When transferring memsize parameter to linux, some versions
500 expect it to be in bytes, others in MB.
501 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
505 New kernel versions are expecting firmware settings to be
506 passed using flattened device trees (based on open firmware
510 * New libfdt-based support
511 * Adds the "fdt" command
512 * The bootm command automatically updates the fdt
514 OF_CPU - The proper name of the cpus node (only required for
515 MPC512X and MPC5xxx based boards).
516 OF_SOC - The proper name of the soc node (only required for
517 MPC512X and MPC5xxx based boards).
518 OF_TBCLK - The timebase frequency.
519 OF_STDOUT_PATH - The path to the console device
521 boards with QUICC Engines require OF_QE to set UCC MAC
524 CONFIG_OF_BOARD_SETUP
526 Board code has addition modification that it wants to make
527 to the flat device tree before handing it off to the kernel
531 This define fills in the correct boot CPU in the boot
532 param header, the default value is zero if undefined.
536 U-Boot can detect if an IDE device is present or not.
537 If not, and this new config option is activated, U-Boot
538 removes the ATA node from the DTS before booting Linux,
539 so the Linux IDE driver does not probe the device and
540 crash. This is needed for buggy hardware (uc101) where
541 no pull down resistor is connected to the signal IDE5V_DD7.
543 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
545 This setting is mandatory for all boards that have only one
546 machine type and must be used to specify the machine type
547 number as it appears in the ARM machine registry
548 (see http://www.arm.linux.org.uk/developer/machines/).
549 Only boards that have multiple machine types supported
550 in a single configuration file and the machine type is
551 runtime discoverable, do not have to use this setting.
553 - vxWorks boot parameters:
555 bootvx constructs a valid bootline using the following
556 environments variables: bootfile, ipaddr, serverip, hostname.
557 It loads the vxWorks image pointed bootfile.
559 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
560 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
561 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
562 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
564 CONFIG_SYS_VXWORKS_ADD_PARAMS
566 Add it at the end of the bootline. E.g "u=username pw=secret"
568 Note: If a "bootargs" environment is defined, it will overwride
569 the defaults discussed just above.
571 - Cache Configuration:
572 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
573 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
574 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
576 - Cache Configuration for ARM:
577 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
579 CONFIG_SYS_PL310_BASE - Physical base address of PL310
580 controller register space
585 Define this if you want support for Amba PrimeCell PL010 UARTs.
589 Define this if you want support for Amba PrimeCell PL011 UARTs.
593 If you have Amba PrimeCell PL011 UARTs, set this variable to
594 the clock speed of the UARTs.
598 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
599 define this to a list of base addresses for each (supported)
600 port. See e.g. include/configs/versatile.h
602 CONFIG_PL011_SERIAL_RLCR
604 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
605 have separate receive and transmit line control registers. Set
606 this variable to initialize the extra register.
608 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
610 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
611 boot loader that has already initialized the UART. Define this
612 variable to flush the UART at init time.
616 Depending on board, define exactly one serial port
617 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
618 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
619 console by defining CONFIG_8xx_CONS_NONE
621 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
622 port routines must be defined elsewhere
623 (i.e. serial_init(), serial_getc(), ...)
626 Enables console device for a color framebuffer. Needs following
627 defines (cf. smiLynxEM, i8042)
628 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
630 VIDEO_HW_RECTFILL graphic chip supports
633 VIDEO_HW_BITBLT graphic chip supports
634 bit-blit (cf. smiLynxEM)
635 VIDEO_VISIBLE_COLS visible pixel columns
637 VIDEO_VISIBLE_ROWS visible pixel rows
638 VIDEO_PIXEL_SIZE bytes per pixel
639 VIDEO_DATA_FORMAT graphic data format
640 (0-5, cf. cfb_console.c)
641 VIDEO_FB_ADRS framebuffer address
642 VIDEO_KBD_INIT_FCT keyboard int fct
643 (i.e. i8042_kbd_init())
644 VIDEO_TSTC_FCT test char fct
646 VIDEO_GETC_FCT get char fct
648 CONFIG_CONSOLE_CURSOR cursor drawing on/off
649 (requires blink timer
651 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
652 CONFIG_CONSOLE_TIME display time/date info in
654 (requires CONFIG_CMD_DATE)
655 CONFIG_VIDEO_LOGO display Linux logo in
657 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
658 linux_logo.h for logo.
659 Requires CONFIG_VIDEO_LOGO
660 CONFIG_CONSOLE_EXTRA_INFO
661 additional board info beside
664 When CONFIG_CFB_CONSOLE is defined, video console is
665 default i/o. Serial console can be forced with
666 environment 'console=serial'.
668 When CONFIG_SILENT_CONSOLE is defined, all console
669 messages (by U-Boot and Linux!) can be silenced with
670 the "silent" environment variable. See
671 doc/README.silent for more information.
674 CONFIG_BAUDRATE - in bps
675 Select one of the baudrates listed in
676 CONFIG_SYS_BAUDRATE_TABLE, see below.
677 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
679 - Console Rx buffer length
680 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
681 the maximum receive buffer length for the SMC.
682 This option is actual only for 82xx and 8xx possible.
683 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
684 must be defined, to setup the maximum idle timeout for
687 - Pre-Console Buffer:
688 Prior to the console being initialised (i.e. serial UART
689 initialised etc) all console output is silently discarded.
690 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
691 buffer any console messages prior to the console being
692 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
693 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
694 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
695 bytes are output before the console is initialised, the
696 earlier bytes are discarded.
698 'Sane' compilers will generate smaller code if
699 CONFIG_PRE_CON_BUF_SZ is a power of 2
701 - Safe printf() functions
702 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
703 the printf() functions. These are defined in
704 include/vsprintf.h and include snprintf(), vsnprintf() and
705 so on. Code size increase is approximately 300-500 bytes.
706 If this option is not given then these functions will
707 silently discard their buffer size argument - this means
708 you are not getting any overflow checking in this case.
710 - Boot Delay: CONFIG_BOOTDELAY - in seconds
711 Delay before automatically booting the default image;
712 set to -1 to disable autoboot.
713 set to -2 to autoboot with no delay and not check for abort
714 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
716 See doc/README.autoboot for these options that
717 work with CONFIG_BOOTDELAY. None are required.
718 CONFIG_BOOT_RETRY_TIME
719 CONFIG_BOOT_RETRY_MIN
720 CONFIG_AUTOBOOT_KEYED
721 CONFIG_AUTOBOOT_PROMPT
722 CONFIG_AUTOBOOT_DELAY_STR
723 CONFIG_AUTOBOOT_STOP_STR
724 CONFIG_AUTOBOOT_DELAY_STR2
725 CONFIG_AUTOBOOT_STOP_STR2
726 CONFIG_ZERO_BOOTDELAY_CHECK
727 CONFIG_RESET_TO_RETRY
731 Only needed when CONFIG_BOOTDELAY is enabled;
732 define a command string that is automatically executed
733 when no character is read on the console interface
734 within "Boot Delay" after reset.
737 This can be used to pass arguments to the bootm
738 command. The value of CONFIG_BOOTARGS goes into the
739 environment value "bootargs".
741 CONFIG_RAMBOOT and CONFIG_NFSBOOT
742 The value of these goes into the environment as
743 "ramboot" and "nfsboot" respectively, and can be used
744 as a convenience, when switching between booting from
750 When this option is #defined, the existence of the
751 environment variable "preboot" will be checked
752 immediately before starting the CONFIG_BOOTDELAY
753 countdown and/or running the auto-boot command resp.
754 entering interactive mode.
756 This feature is especially useful when "preboot" is
757 automatically generated or modified. For an example
758 see the LWMON board specific code: here "preboot" is
759 modified when the user holds down a certain
760 combination of keys on the (special) keyboard when
763 - Serial Download Echo Mode:
765 If defined to 1, all characters received during a
766 serial download (using the "loads" command) are
767 echoed back. This might be needed by some terminal
768 emulations (like "cu"), but may as well just take
769 time on others. This setting #define's the initial
770 value of the "loads_echo" environment variable.
772 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
774 Select one of the baudrates listed in
775 CONFIG_SYS_BAUDRATE_TABLE, see below.
778 Monitor commands can be included or excluded
779 from the build by using the #include files
780 <config_cmd_all.h> and #undef'ing unwanted
781 commands, or using <config_cmd_default.h>
782 and augmenting with additional #define's
785 The default command configuration includes all commands
786 except those marked below with a "*".
788 CONFIG_CMD_ASKENV * ask for env variable
789 CONFIG_CMD_BDI bdinfo
790 CONFIG_CMD_BEDBUG * Include BedBug Debugger
791 CONFIG_CMD_BMP * BMP support
792 CONFIG_CMD_BSP * Board specific commands
793 CONFIG_CMD_BOOTD bootd
794 CONFIG_CMD_CACHE * icache, dcache
795 CONFIG_CMD_CONSOLE coninfo
796 CONFIG_CMD_CRC32 * crc32
797 CONFIG_CMD_DATE * support for RTC, date/time...
798 CONFIG_CMD_DHCP * DHCP support
799 CONFIG_CMD_DIAG * Diagnostics
800 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
801 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
802 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
803 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
804 CONFIG_CMD_DTT * Digital Therm and Thermostat
805 CONFIG_CMD_ECHO echo arguments
806 CONFIG_CMD_EDITENV edit env variable
807 CONFIG_CMD_EEPROM * EEPROM read/write support
808 CONFIG_CMD_ELF * bootelf, bootvx
809 CONFIG_CMD_EXPORTENV * export the environment
810 CONFIG_CMD_EXT2 * ext2 command support
811 CONFIG_CMD_EXT4 * ext4 command support
812 CONFIG_CMD_SAVEENV saveenv
813 CONFIG_CMD_FDC * Floppy Disk Support
814 CONFIG_CMD_FAT * FAT command support
815 CONFIG_CMD_FDOS * Dos diskette Support
816 CONFIG_CMD_FLASH flinfo, erase, protect
817 CONFIG_CMD_FPGA FPGA device initialization support
818 CONFIG_CMD_GO * the 'go' command (exec code)
819 CONFIG_CMD_GREPENV * search environment
820 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
821 CONFIG_CMD_I2C * I2C serial bus support
822 CONFIG_CMD_IDE * IDE harddisk support
823 CONFIG_CMD_IMI iminfo
824 CONFIG_CMD_IMLS List all found images
825 CONFIG_CMD_IMMAP * IMMR dump support
826 CONFIG_CMD_IMPORTENV * import an environment
827 CONFIG_CMD_INI * import data from an ini file into the env
828 CONFIG_CMD_IRQ * irqinfo
829 CONFIG_CMD_ITEST Integer/string test of 2 values
830 CONFIG_CMD_JFFS2 * JFFS2 Support
831 CONFIG_CMD_KGDB * kgdb
832 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
833 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
835 CONFIG_CMD_LOADB loadb
836 CONFIG_CMD_LOADS loads
837 CONFIG_CMD_MD5SUM print md5 message digest
838 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
839 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
841 CONFIG_CMD_MISC Misc functions like sleep etc
842 CONFIG_CMD_MMC * MMC memory mapped support
843 CONFIG_CMD_MII * MII utility commands
844 CONFIG_CMD_MTDPARTS * MTD partition support
845 CONFIG_CMD_NAND * NAND support
846 CONFIG_CMD_NET bootp, tftpboot, rarpboot
847 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
848 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
849 CONFIG_CMD_PCI * pciinfo
850 CONFIG_CMD_PCMCIA * PCMCIA support
851 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
853 CONFIG_CMD_PORTIO * Port I/O
854 CONFIG_CMD_REGINFO * Register dump
855 CONFIG_CMD_RUN run command in env variable
856 CONFIG_CMD_SAVES * save S record dump
857 CONFIG_CMD_SCSI * SCSI Support
858 CONFIG_CMD_SDRAM * print SDRAM configuration information
859 (requires CONFIG_CMD_I2C)
860 CONFIG_CMD_SETGETDCR Support for DCR Register access
862 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
863 CONFIG_CMD_SHA1SUM print sha1 memory digest
864 (requires CONFIG_CMD_MEMORY)
865 CONFIG_CMD_SOURCE "source" command Support
866 CONFIG_CMD_SPI * SPI serial bus support
867 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
868 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
869 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
870 CONFIG_CMD_TIMER * access to the system tick timer
871 CONFIG_CMD_USB * USB support
872 CONFIG_CMD_CDP * Cisco Discover Protocol support
873 CONFIG_CMD_MFSL * Microblaze FSL support
876 EXAMPLE: If you want all functions except of network
877 support you can write:
879 #include "config_cmd_all.h"
880 #undef CONFIG_CMD_NET
883 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
885 Note: Don't enable the "icache" and "dcache" commands
886 (configuration option CONFIG_CMD_CACHE) unless you know
887 what you (and your U-Boot users) are doing. Data
888 cache cannot be enabled on systems like the 8xx or
889 8260 (where accesses to the IMMR region must be
890 uncached), and it cannot be disabled on all other
891 systems where we (mis-) use the data cache to hold an
892 initial stack and some data.
895 XXX - this list needs to get updated!
899 If this variable is defined, U-Boot will use a device tree
900 to configure its devices, instead of relying on statically
901 compiled #defines in the board file. This option is
902 experimental and only available on a few boards. The device
903 tree is available in the global data as gd->fdt_blob.
905 U-Boot needs to get its device tree from somewhere. This can
906 be done using one of the two options below:
909 If this variable is defined, U-Boot will embed a device tree
910 binary in its image. This device tree file should be in the
911 board directory and called <soc>-<board>.dts. The binary file
912 is then picked up in board_init_f() and made available through
913 the global data structure as gd->blob.
916 If this variable is defined, U-Boot will build a device tree
917 binary. It will be called u-boot.dtb. Architecture-specific
918 code will locate it at run-time. Generally this works by:
920 cat u-boot.bin u-boot.dtb >image.bin
922 and in fact, U-Boot does this for you, creating a file called
923 u-boot-dtb.bin which is useful in the common case. You can
924 still use the individual files if you need something more
929 If this variable is defined, it enables watchdog
930 support for the SoC. There must be support in the SoC
931 specific code for a watchdog. For the 8xx and 8260
932 CPUs, the SIU Watchdog feature is enabled in the SYPCR
933 register. When supported for a specific SoC is
934 available, then no further board specific code should
938 When using a watchdog circuitry external to the used
939 SoC, then define this variable and provide board
940 specific code for the "hw_watchdog_reset" function.
943 CONFIG_VERSION_VARIABLE
944 If this variable is defined, an environment variable
945 named "ver" is created by U-Boot showing the U-Boot
946 version as printed by the "version" command.
947 Any change to this variable will be reverted at the
952 When CONFIG_CMD_DATE is selected, the type of the RTC
953 has to be selected, too. Define exactly one of the
956 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
957 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
958 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
959 CONFIG_RTC_MC146818 - use MC146818 RTC
960 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
961 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
962 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
963 CONFIG_RTC_DS164x - use Dallas DS164x RTC
964 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
965 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
966 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
967 CONFIG_SYS_RV3029_TCR - enable trickle charger on
970 Note that if the RTC uses I2C, then the I2C interface
971 must also be configured. See I2C Support, below.
974 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
975 CONFIG_PCA953X_INFO - enable pca953x info command
977 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
978 chip-ngpio pairs that tell the PCA953X driver the number of
979 pins supported by a particular chip.
981 Note that if the GPIO device uses I2C, then the I2C interface
982 must also be configured. See I2C Support, below.
986 When CONFIG_TIMESTAMP is selected, the timestamp
987 (date and time) of an image is printed by image
988 commands like bootm or iminfo. This option is
989 automatically enabled when you select CONFIG_CMD_DATE .
991 - Partition Labels (disklabels) Supported:
992 Zero or more of the following:
993 CONFIG_MAC_PARTITION Apple's MacOS partition table.
994 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
995 Intel architecture, USB sticks, etc.
996 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
997 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
998 bootloader. Note 2TB partition limit; see
1000 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1002 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1003 CONFIG_CMD_SCSI) you must configure support for at
1004 least one non-MTD partition type as well.
1007 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1008 board configurations files but used nowhere!
1010 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1011 be performed by calling the function
1012 ide_set_reset(int reset)
1013 which has to be defined in a board specific file
1018 Set this to enable ATAPI support.
1023 Set this to enable support for disks larger than 137GB
1024 Also look at CONFIG_SYS_64BIT_LBA.
1025 Whithout these , LBA48 support uses 32bit variables and will 'only'
1026 support disks up to 2.1TB.
1028 CONFIG_SYS_64BIT_LBA:
1029 When enabled, makes the IDE subsystem use 64bit sector addresses.
1033 At the moment only there is only support for the
1034 SYM53C8XX SCSI controller; define
1035 CONFIG_SCSI_SYM53C8XX to enable it.
1037 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1038 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1039 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1040 maximum numbers of LUNs, SCSI ID's and target
1042 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1044 The environment variable 'scsidevs' is set to the number of
1045 SCSI devices found during the last scan.
1047 - NETWORK Support (PCI):
1049 Support for Intel 8254x/8257x gigabit chips.
1052 Utility code for direct access to the SPI bus on Intel 8257x.
1053 This does not do anything useful unless you set at least one
1054 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1056 CONFIG_E1000_SPI_GENERIC
1057 Allow generic access to the SPI bus on the Intel 8257x, for
1058 example with the "sspi" command.
1061 Management command for E1000 devices. When used on devices
1062 with SPI support you can reprogram the EEPROM from U-Boot.
1064 CONFIG_E1000_FALLBACK_MAC
1065 default MAC for empty EEPROM after production.
1068 Support for Intel 82557/82559/82559ER chips.
1069 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1070 write routine for first time initialisation.
1073 Support for Digital 2114x chips.
1074 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1075 modem chip initialisation (KS8761/QS6611).
1078 Support for National dp83815 chips.
1081 Support for National dp8382[01] gigabit chips.
1083 - NETWORK Support (other):
1085 CONFIG_DRIVER_AT91EMAC
1086 Support for AT91RM9200 EMAC.
1089 Define this to use reduced MII inteface
1091 CONFIG_DRIVER_AT91EMAC_QUIET
1092 If this defined, the driver is quiet.
1093 The driver doen't show link status messages.
1095 CONFIG_CALXEDA_XGMAC
1096 Support for the Calxeda XGMAC device
1099 Support for SMSC's LAN91C96 chips.
1101 CONFIG_LAN91C96_BASE
1102 Define this to hold the physical address
1103 of the LAN91C96's I/O space
1105 CONFIG_LAN91C96_USE_32_BIT
1106 Define this to enable 32 bit addressing
1109 Support for SMSC's LAN91C111 chip
1111 CONFIG_SMC91111_BASE
1112 Define this to hold the physical address
1113 of the device (I/O space)
1115 CONFIG_SMC_USE_32_BIT
1116 Define this if data bus is 32 bits
1118 CONFIG_SMC_USE_IOFUNCS
1119 Define this to use i/o functions instead of macros
1120 (some hardware wont work with macros)
1122 CONFIG_DRIVER_TI_EMAC
1123 Support for davinci emac
1125 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1126 Define this if you have more then 3 PHYs.
1129 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1131 CONFIG_FTGMAC100_EGIGA
1132 Define this to use GE link update with gigabit PHY.
1133 Define this if FTGMAC100 is connected to gigabit PHY.
1134 If your system has 10/100 PHY only, it might not occur
1135 wrong behavior. Because PHY usually return timeout or
1136 useless data when polling gigabit status and gigabit
1137 control registers. This behavior won't affect the
1138 correctnessof 10/100 link speed update.
1141 Support for SMSC's LAN911x and LAN921x chips
1144 Define this to hold the physical address
1145 of the device (I/O space)
1147 CONFIG_SMC911X_32_BIT
1148 Define this if data bus is 32 bits
1150 CONFIG_SMC911X_16_BIT
1151 Define this if data bus is 16 bits. If your processor
1152 automatically converts one 32 bit word to two 16 bit
1153 words you may also try CONFIG_SMC911X_32_BIT.
1156 Support for Renesas on-chip Ethernet controller
1158 CONFIG_SH_ETHER_USE_PORT
1159 Define the number of ports to be used
1161 CONFIG_SH_ETHER_PHY_ADDR
1162 Define the ETH PHY's address
1164 CONFIG_SH_ETHER_CACHE_WRITEBACK
1165 If this option is set, the driver enables cache flush.
1168 CONFIG_GENERIC_LPC_TPM
1169 Support for generic parallel port TPM devices. Only one device
1170 per system is supported at this time.
1172 CONFIG_TPM_TIS_BASE_ADDRESS
1173 Base address where the generic TPM device is mapped
1174 to. Contemporary x86 systems usually map it at
1178 At the moment only the UHCI host controller is
1179 supported (PIP405, MIP405, MPC5200); define
1180 CONFIG_USB_UHCI to enable it.
1181 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1182 and define CONFIG_USB_STORAGE to enable the USB
1185 Supported are USB Keyboards and USB Floppy drives
1187 MPC5200 USB requires additional defines:
1189 for 528 MHz Clock: 0x0001bbbb
1193 for differential drivers: 0x00001000
1194 for single ended drivers: 0x00005000
1195 for differential drivers on PSC3: 0x00000100
1196 for single ended drivers on PSC3: 0x00004100
1197 CONFIG_SYS_USB_EVENT_POLL
1198 May be defined to allow interrupt polling
1199 instead of using asynchronous interrupts
1201 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1202 txfilltuning field in the EHCI controller on reset.
1205 Define the below if you wish to use the USB console.
1206 Once firmware is rebuilt from a serial console issue the
1207 command "setenv stdin usbtty; setenv stdout usbtty" and
1208 attach your USB cable. The Unix command "dmesg" should print
1209 it has found a new device. The environment variable usbtty
1210 can be set to gserial or cdc_acm to enable your device to
1211 appear to a USB host as a Linux gserial device or a
1212 Common Device Class Abstract Control Model serial device.
1213 If you select usbtty = gserial you should be able to enumerate
1215 # modprobe usbserial vendor=0xVendorID product=0xProductID
1216 else if using cdc_acm, simply setting the environment
1217 variable usbtty to be cdc_acm should suffice. The following
1218 might be defined in YourBoardName.h
1221 Define this to build a UDC device
1224 Define this to have a tty type of device available to
1225 talk to the UDC device
1228 Define this to enable the high speed support for usb
1229 device and usbtty. If this feature is enabled, a routine
1230 int is_usbd_high_speed(void)
1231 also needs to be defined by the driver to dynamically poll
1232 whether the enumeration has succeded at high speed or full
1235 CONFIG_SYS_CONSOLE_IS_IN_ENV
1236 Define this if you want stdin, stdout &/or stderr to
1240 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1241 Derive USB clock from external clock "blah"
1242 - CONFIG_SYS_USB_EXTC_CLK 0x02
1244 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1245 Derive USB clock from brgclk
1246 - CONFIG_SYS_USB_BRG_CLK 0x04
1248 If you have a USB-IF assigned VendorID then you may wish to
1249 define your own vendor specific values either in BoardName.h
1250 or directly in usbd_vendor_info.h. If you don't define
1251 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1252 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1253 should pretend to be a Linux device to it's target host.
1255 CONFIG_USBD_MANUFACTURER
1256 Define this string as the name of your company for
1257 - CONFIG_USBD_MANUFACTURER "my company"
1259 CONFIG_USBD_PRODUCT_NAME
1260 Define this string as the name of your product
1261 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1263 CONFIG_USBD_VENDORID
1264 Define this as your assigned Vendor ID from the USB
1265 Implementors Forum. This *must* be a genuine Vendor ID
1266 to avoid polluting the USB namespace.
1267 - CONFIG_USBD_VENDORID 0xFFFF
1269 CONFIG_USBD_PRODUCTID
1270 Define this as the unique Product ID
1272 - CONFIG_USBD_PRODUCTID 0xFFFF
1274 - ULPI Layer Support:
1275 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1276 the generic ULPI layer. The generic layer accesses the ULPI PHY
1277 via the platform viewport, so you need both the genric layer and
1278 the viewport enabled. Currently only Chipidea/ARC based
1279 viewport is supported.
1280 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1281 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1282 If your ULPI phy needs a different reference clock than the
1283 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1284 the appropriate value in Hz.
1287 The MMC controller on the Intel PXA is supported. To
1288 enable this define CONFIG_MMC. The MMC can be
1289 accessed from the boot prompt by mapping the device
1290 to physical memory similar to flash. Command line is
1291 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1292 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1295 Support for Renesas on-chip MMCIF controller
1297 CONFIG_SH_MMCIF_ADDR
1298 Define the base address of MMCIF registers
1301 Define the clock frequency for MMCIF
1303 - Journaling Flash filesystem support:
1304 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1305 CONFIG_JFFS2_NAND_DEV
1306 Define these for a default partition on a NAND device
1308 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1309 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1310 Define these for a default partition on a NOR device
1312 CONFIG_SYS_JFFS_CUSTOM_PART
1313 Define this to create an own partition. You have to provide a
1314 function struct part_info* jffs2_part_info(int part_num)
1316 If you define only one JFFS2 partition you may also want to
1317 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1318 to disable the command chpart. This is the default when you
1319 have not defined a custom partition
1321 - FAT(File Allocation Table) filesystem write function support:
1324 Define this to enable support for saving memory data as a
1325 file in FAT formatted partition.
1327 This will also enable the command "fatwrite" enabling the
1328 user to write files to FAT.
1330 CBFS (Coreboot Filesystem) support
1333 Define this to enable support for reading from a Coreboot
1334 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1340 Define this to enable standard (PC-Style) keyboard
1344 Standard PC keyboard driver with US (is default) and
1345 GERMAN key layout (switch via environment 'keymap=de') support.
1346 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1347 for cfb_console. Supports cursor blinking.
1352 Define this to enable video support (for output to
1355 CONFIG_VIDEO_CT69000
1357 Enable Chips & Technologies 69000 Video chip
1359 CONFIG_VIDEO_SMI_LYNXEM
1360 Enable Silicon Motion SMI 712/710/810 Video chip. The
1361 video output is selected via environment 'videoout'
1362 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1365 For the CT69000 and SMI_LYNXEM drivers, videomode is
1366 selected via environment 'videomode'. Two different ways
1368 - "videomode=num" 'num' is a standard LiLo mode numbers.
1369 Following standard modes are supported (* is default):
1371 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1372 -------------+---------------------------------------------
1373 8 bits | 0x301* 0x303 0x305 0x161 0x307
1374 15 bits | 0x310 0x313 0x316 0x162 0x319
1375 16 bits | 0x311 0x314 0x317 0x163 0x31A
1376 24 bits | 0x312 0x315 0x318 ? 0x31B
1377 -------------+---------------------------------------------
1378 (i.e. setenv videomode 317; saveenv; reset;)
1380 - "videomode=bootargs" all the video parameters are parsed
1381 from the bootargs. (See drivers/video/videomodes.c)
1384 CONFIG_VIDEO_SED13806
1385 Enable Epson SED13806 driver. This driver supports 8bpp
1386 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1387 or CONFIG_VIDEO_SED13806_16BPP
1390 Enable the Freescale DIU video driver. Reference boards for
1391 SOCs that have a DIU should define this macro to enable DIU
1392 support, and should also define these other macros:
1398 CONFIG_VIDEO_SW_CURSOR
1399 CONFIG_VGA_AS_SINGLE_DEVICE
1401 CONFIG_VIDEO_BMP_LOGO
1403 The DIU driver will look for the 'video-mode' environment
1404 variable, and if defined, enable the DIU as a console during
1405 boot. See the documentation file README.video for a
1406 description of this variable.
1411 Define this to enable a custom keyboard support.
1412 This simply calls drv_keyboard_init() which must be
1413 defined in your board-specific files.
1414 The only board using this so far is RBC823.
1416 - LCD Support: CONFIG_LCD
1418 Define this to enable LCD support (for output to LCD
1419 display); also select one of the supported displays
1420 by defining one of these:
1424 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1426 CONFIG_NEC_NL6448AC33:
1428 NEC NL6448AC33-18. Active, color, single scan.
1430 CONFIG_NEC_NL6448BC20
1432 NEC NL6448BC20-08. 6.5", 640x480.
1433 Active, color, single scan.
1435 CONFIG_NEC_NL6448BC33_54
1437 NEC NL6448BC33-54. 10.4", 640x480.
1438 Active, color, single scan.
1442 Sharp 320x240. Active, color, single scan.
1443 It isn't 16x9, and I am not sure what it is.
1445 CONFIG_SHARP_LQ64D341
1447 Sharp LQ64D341 display, 640x480.
1448 Active, color, single scan.
1452 HLD1045 display, 640x480.
1453 Active, color, single scan.
1457 Optrex CBL50840-2 NF-FW 99 22 M5
1459 Hitachi LMG6912RPFC-00T
1463 320x240. Black & white.
1465 Normally display is black on white background; define
1466 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1468 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1470 If this option is set, the environment is checked for
1471 a variable "splashimage". If found, the usual display
1472 of logo, copyright and system information on the LCD
1473 is suppressed and the BMP image at the address
1474 specified in "splashimage" is loaded instead. The
1475 console is redirected to the "nulldev", too. This
1476 allows for a "silent" boot where a splash screen is
1477 loaded very quickly after power-on.
1479 CONFIG_SPLASH_SCREEN_ALIGN
1481 If this option is set the splash image can be freely positioned
1482 on the screen. Environment variable "splashpos" specifies the
1483 position as "x,y". If a positive number is given it is used as
1484 number of pixel from left/top. If a negative number is given it
1485 is used as number of pixel from right/bottom. You can also
1486 specify 'm' for centering the image.
1489 setenv splashpos m,m
1490 => image at center of screen
1492 setenv splashpos 30,20
1493 => image at x = 30 and y = 20
1495 setenv splashpos -10,m
1496 => vertically centered image
1497 at x = dspWidth - bmpWidth - 9
1499 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1501 If this option is set, additionally to standard BMP
1502 images, gzipped BMP images can be displayed via the
1503 splashscreen support or the bmp command.
1505 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1507 If this option is set, 8-bit RLE compressed BMP images
1508 can be displayed via the splashscreen support or the
1511 - Do compresssing for memory range:
1514 If this option is set, it would use zlib deflate method
1515 to compress the specified memory at its best effort.
1517 - Compression support:
1520 If this option is set, support for bzip2 compressed
1521 images is included. If not, only uncompressed and gzip
1522 compressed images are supported.
1524 NOTE: the bzip2 algorithm requires a lot of RAM, so
1525 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1530 If this option is set, support for lzma compressed
1533 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1534 requires an amount of dynamic memory that is given by the
1537 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1539 Where lc and lp stand for, respectively, Literal context bits
1540 and Literal pos bits.
1542 This value is upper-bounded by 14MB in the worst case. Anyway,
1543 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1544 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1545 a very small buffer.
1547 Use the lzmainfo tool to determinate the lc and lp values and
1548 then calculate the amount of needed dynamic memory (ensuring
1549 the appropriate CONFIG_SYS_MALLOC_LEN value).
1554 The address of PHY on MII bus.
1556 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1558 The clock frequency of the MII bus
1562 If this option is set, support for speed/duplex
1563 detection of gigabit PHY is included.
1565 CONFIG_PHY_RESET_DELAY
1567 Some PHY like Intel LXT971A need extra delay after
1568 reset before any MII register access is possible.
1569 For such PHY, set this option to the usec delay
1570 required. (minimum 300usec for LXT971A)
1572 CONFIG_PHY_CMD_DELAY (ppc4xx)
1574 Some PHY like Intel LXT971A need extra delay after
1575 command issued before MII status register can be read
1585 Define a default value for Ethernet address to use
1586 for the respective Ethernet interface, in case this
1587 is not determined automatically.
1592 Define a default value for the IP address to use for
1593 the default Ethernet interface, in case this is not
1594 determined through e.g. bootp.
1595 (Environment variable "ipaddr")
1597 - Server IP address:
1600 Defines a default value for the IP address of a TFTP
1601 server to contact when using the "tftboot" command.
1602 (Environment variable "serverip")
1604 CONFIG_KEEP_SERVERADDR
1606 Keeps the server's MAC address, in the env 'serveraddr'
1607 for passing to bootargs (like Linux's netconsole option)
1609 - Gateway IP address:
1612 Defines a default value for the IP address of the
1613 default router where packets to other networks are
1615 (Environment variable "gatewayip")
1620 Defines a default value for the subnet mask (or
1621 routing prefix) which is used to determine if an IP
1622 address belongs to the local subnet or needs to be
1623 forwarded through a router.
1624 (Environment variable "netmask")
1626 - Multicast TFTP Mode:
1629 Defines whether you want to support multicast TFTP as per
1630 rfc-2090; for example to work with atftp. Lets lots of targets
1631 tftp down the same boot image concurrently. Note: the Ethernet
1632 driver in use must provide a function: mcast() to join/leave a
1635 - BOOTP Recovery Mode:
1636 CONFIG_BOOTP_RANDOM_DELAY
1638 If you have many targets in a network that try to
1639 boot using BOOTP, you may want to avoid that all
1640 systems send out BOOTP requests at precisely the same
1641 moment (which would happen for instance at recovery
1642 from a power failure, when all systems will try to
1643 boot, thus flooding the BOOTP server. Defining
1644 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1645 inserted before sending out BOOTP requests. The
1646 following delays are inserted then:
1648 1st BOOTP request: delay 0 ... 1 sec
1649 2nd BOOTP request: delay 0 ... 2 sec
1650 3rd BOOTP request: delay 0 ... 4 sec
1652 BOOTP requests: delay 0 ... 8 sec
1654 - DHCP Advanced Options:
1655 You can fine tune the DHCP functionality by defining
1656 CONFIG_BOOTP_* symbols:
1658 CONFIG_BOOTP_SUBNETMASK
1659 CONFIG_BOOTP_GATEWAY
1660 CONFIG_BOOTP_HOSTNAME
1661 CONFIG_BOOTP_NISDOMAIN
1662 CONFIG_BOOTP_BOOTPATH
1663 CONFIG_BOOTP_BOOTFILESIZE
1666 CONFIG_BOOTP_SEND_HOSTNAME
1667 CONFIG_BOOTP_NTPSERVER
1668 CONFIG_BOOTP_TIMEOFFSET
1669 CONFIG_BOOTP_VENDOREX
1670 CONFIG_BOOTP_MAY_FAIL
1672 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1673 environment variable, not the BOOTP server.
1675 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1676 after the configured retry count, the call will fail
1677 instead of starting over. This can be used to fail over
1678 to Link-local IP address configuration if the DHCP server
1681 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1682 serverip from a DHCP server, it is possible that more
1683 than one DNS serverip is offered to the client.
1684 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1685 serverip will be stored in the additional environment
1686 variable "dnsip2". The first DNS serverip is always
1687 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1690 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1691 to do a dynamic update of a DNS server. To do this, they
1692 need the hostname of the DHCP requester.
1693 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1694 of the "hostname" environment variable is passed as
1695 option 12 to the DHCP server.
1697 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1699 A 32bit value in microseconds for a delay between
1700 receiving a "DHCP Offer" and sending the "DHCP Request".
1701 This fixes a problem with certain DHCP servers that don't
1702 respond 100% of the time to a "DHCP request". E.g. On an
1703 AT91RM9200 processor running at 180MHz, this delay needed
1704 to be *at least* 15,000 usec before a Windows Server 2003
1705 DHCP server would reply 100% of the time. I recommend at
1706 least 50,000 usec to be safe. The alternative is to hope
1707 that one of the retries will be successful but note that
1708 the DHCP timeout and retry process takes a longer than
1711 - Link-local IP address negotiation:
1712 Negotiate with other link-local clients on the local network
1713 for an address that doesn't require explicit configuration.
1714 This is especially useful if a DHCP server cannot be guaranteed
1715 to exist in all environments that the device must operate.
1717 See doc/README.link-local for more information.
1720 CONFIG_CDP_DEVICE_ID
1722 The device id used in CDP trigger frames.
1724 CONFIG_CDP_DEVICE_ID_PREFIX
1726 A two character string which is prefixed to the MAC address
1731 A printf format string which contains the ascii name of
1732 the port. Normally is set to "eth%d" which sets
1733 eth0 for the first Ethernet, eth1 for the second etc.
1735 CONFIG_CDP_CAPABILITIES
1737 A 32bit integer which indicates the device capabilities;
1738 0x00000010 for a normal host which does not forwards.
1742 An ascii string containing the version of the software.
1746 An ascii string containing the name of the platform.
1750 A 32bit integer sent on the trigger.
1752 CONFIG_CDP_POWER_CONSUMPTION
1754 A 16bit integer containing the power consumption of the
1755 device in .1 of milliwatts.
1757 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1759 A byte containing the id of the VLAN.
1761 - Status LED: CONFIG_STATUS_LED
1763 Several configurations allow to display the current
1764 status using a LED. For instance, the LED will blink
1765 fast while running U-Boot code, stop blinking as
1766 soon as a reply to a BOOTP request was received, and
1767 start blinking slow once the Linux kernel is running
1768 (supported by a status LED driver in the Linux
1769 kernel). Defining CONFIG_STATUS_LED enables this
1772 - CAN Support: CONFIG_CAN_DRIVER
1774 Defining CONFIG_CAN_DRIVER enables CAN driver support
1775 on those systems that support this (optional)
1776 feature, like the TQM8xxL modules.
1778 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1780 These enable I2C serial bus commands. Defining either of
1781 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1782 include the appropriate I2C driver for the selected CPU.
1784 This will allow you to use i2c commands at the u-boot
1785 command line (as long as you set CONFIG_CMD_I2C in
1786 CONFIG_COMMANDS) and communicate with i2c based realtime
1787 clock chips. See common/cmd_i2c.c for a description of the
1788 command line interface.
1790 CONFIG_HARD_I2C selects a hardware I2C controller.
1792 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1793 bit-banging) driver instead of CPM or similar hardware
1796 There are several other quantities that must also be
1797 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1799 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1800 to be the frequency (in Hz) at which you wish your i2c bus
1801 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1802 the CPU's i2c node address).
1804 Now, the u-boot i2c code for the mpc8xx
1805 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1806 and so its address should therefore be cleared to 0 (See,
1807 eg, MPC823e User's Manual p.16-473). So, set
1808 CONFIG_SYS_I2C_SLAVE to 0.
1810 CONFIG_SYS_I2C_INIT_MPC5XXX
1812 When a board is reset during an i2c bus transfer
1813 chips might think that the current transfer is still
1814 in progress. Reset the slave devices by sending start
1815 commands until the slave device responds.
1817 That's all that's required for CONFIG_HARD_I2C.
1819 If you use the software i2c interface (CONFIG_SOFT_I2C)
1820 then the following macros need to be defined (examples are
1821 from include/configs/lwmon.h):
1825 (Optional). Any commands necessary to enable the I2C
1826 controller or configure ports.
1828 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1832 (Only for MPC8260 CPU). The I/O port to use (the code
1833 assumes both bits are on the same port). Valid values
1834 are 0..3 for ports A..D.
1838 The code necessary to make the I2C data line active
1839 (driven). If the data line is open collector, this
1842 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1846 The code necessary to make the I2C data line tri-stated
1847 (inactive). If the data line is open collector, this
1850 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1854 Code that returns TRUE if the I2C data line is high,
1857 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1861 If <bit> is TRUE, sets the I2C data line high. If it
1862 is FALSE, it clears it (low).
1864 eg: #define I2C_SDA(bit) \
1865 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1866 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1870 If <bit> is TRUE, sets the I2C clock line high. If it
1871 is FALSE, it clears it (low).
1873 eg: #define I2C_SCL(bit) \
1874 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1875 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1879 This delay is invoked four times per clock cycle so this
1880 controls the rate of data transfer. The data rate thus
1881 is 1 / (I2C_DELAY * 4). Often defined to be something
1884 #define I2C_DELAY udelay(2)
1886 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1888 If your arch supports the generic GPIO framework (asm/gpio.h),
1889 then you may alternatively define the two GPIOs that are to be
1890 used as SCL / SDA. Any of the previous I2C_xxx macros will
1891 have GPIO-based defaults assigned to them as appropriate.
1893 You should define these to the GPIO value as given directly to
1894 the generic GPIO functions.
1896 CONFIG_SYS_I2C_INIT_BOARD
1898 When a board is reset during an i2c bus transfer
1899 chips might think that the current transfer is still
1900 in progress. On some boards it is possible to access
1901 the i2c SCLK line directly, either by using the
1902 processor pin as a GPIO or by having a second pin
1903 connected to the bus. If this option is defined a
1904 custom i2c_init_board() routine in boards/xxx/board.c
1905 is run early in the boot sequence.
1907 CONFIG_SYS_I2C_BOARD_LATE_INIT
1909 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1910 defined a custom i2c_board_late_init() routine in
1911 boards/xxx/board.c is run AFTER the operations in i2c_init()
1912 is completed. This callpoint can be used to unreset i2c bus
1913 using CPU i2c controller register accesses for CPUs whose i2c
1914 controller provide such a method. It is called at the end of
1915 i2c_init() to allow i2c_init operations to setup the i2c bus
1916 controller on the CPU (e.g. setting bus speed & slave address).
1918 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1920 This option enables configuration of bi_iic_fast[] flags
1921 in u-boot bd_info structure based on u-boot environment
1922 variable "i2cfast". (see also i2cfast)
1924 CONFIG_I2C_MULTI_BUS
1926 This option allows the use of multiple I2C buses, each of which
1927 must have a controller. At any point in time, only one bus is
1928 active. To switch to a different bus, use the 'i2c dev' command.
1929 Note that bus numbering is zero-based.
1931 CONFIG_SYS_I2C_NOPROBES
1933 This option specifies a list of I2C devices that will be skipped
1934 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1935 is set, specify a list of bus-device pairs. Otherwise, specify
1936 a 1D array of device addresses
1939 #undef CONFIG_I2C_MULTI_BUS
1940 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1942 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1944 #define CONFIG_I2C_MULTI_BUS
1945 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1947 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1949 CONFIG_SYS_SPD_BUS_NUM
1951 If defined, then this indicates the I2C bus number for DDR SPD.
1952 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1954 CONFIG_SYS_RTC_BUS_NUM
1956 If defined, then this indicates the I2C bus number for the RTC.
1957 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1959 CONFIG_SYS_DTT_BUS_NUM
1961 If defined, then this indicates the I2C bus number for the DTT.
1962 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1964 CONFIG_SYS_I2C_DTT_ADDR:
1966 If defined, specifies the I2C address of the DTT device.
1967 If not defined, then U-Boot uses predefined value for
1968 specified DTT device.
1972 Define this option if you want to use Freescale's I2C driver in
1973 drivers/i2c/fsl_i2c.c.
1977 Define this option if you have I2C devices reached over 1 .. n
1978 I2C Muxes like the pca9544a. This option addes a new I2C
1979 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1980 new I2C Bus to the existing I2C Busses. If you select the
1981 new Bus with "i2c dev", u-bbot sends first the commandos for
1982 the muxes to activate this new "bus".
1984 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1988 Adding a new I2C Bus reached over 2 pca9544a muxes
1989 The First mux with address 70 and channel 6
1990 The Second mux with address 71 and channel 4
1992 => i2c bus pca9544a:70:6:pca9544a:71:4
1994 Use the "i2c bus" command without parameter, to get a list
1995 of I2C Busses with muxes:
1998 Busses reached over muxes:
2000 reached over Mux(es):
2003 reached over Mux(es):
2008 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2009 u-boot first sends the command to the mux@70 to enable
2010 channel 6, and then the command to the mux@71 to enable
2013 After that, you can use the "normal" i2c commands as
2014 usual to communicate with your I2C devices behind
2017 This option is actually implemented for the bitbanging
2018 algorithm in common/soft_i2c.c and for the Hardware I2C
2019 Bus on the MPC8260. But it should be not so difficult
2020 to add this option to other architectures.
2022 CONFIG_SOFT_I2C_READ_REPEATED_START
2024 defining this will force the i2c_read() function in
2025 the soft_i2c driver to perform an I2C repeated start
2026 between writing the address pointer and reading the
2027 data. If this define is omitted the default behaviour
2028 of doing a stop-start sequence will be used. Most I2C
2029 devices can use either method, but some require one or
2032 - SPI Support: CONFIG_SPI
2034 Enables SPI driver (so far only tested with
2035 SPI EEPROM, also an instance works with Crystal A/D and
2036 D/As on the SACSng board)
2040 Enables the driver for SPI controller on SuperH. Currently
2041 only SH7757 is supported.
2045 Enables extended (16-bit) SPI EEPROM addressing.
2046 (symmetrical to CONFIG_I2C_X)
2050 Enables a software (bit-bang) SPI driver rather than
2051 using hardware support. This is a general purpose
2052 driver that only requires three general I/O port pins
2053 (two outputs, one input) to function. If this is
2054 defined, the board configuration must define several
2055 SPI configuration items (port pins to use, etc). For
2056 an example, see include/configs/sacsng.h.
2060 Enables a hardware SPI driver for general-purpose reads
2061 and writes. As with CONFIG_SOFT_SPI, the board configuration
2062 must define a list of chip-select function pointers.
2063 Currently supported on some MPC8xxx processors. For an
2064 example, see include/configs/mpc8349emds.h.
2068 Enables the driver for the SPI controllers on i.MX and MXC
2069 SoCs. Currently i.MX31/35/51 are supported.
2071 - FPGA Support: CONFIG_FPGA
2073 Enables FPGA subsystem.
2075 CONFIG_FPGA_<vendor>
2077 Enables support for specific chip vendors.
2080 CONFIG_FPGA_<family>
2082 Enables support for FPGA family.
2083 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2087 Specify the number of FPGA devices to support.
2089 CONFIG_SYS_FPGA_PROG_FEEDBACK
2091 Enable printing of hash marks during FPGA configuration.
2093 CONFIG_SYS_FPGA_CHECK_BUSY
2095 Enable checks on FPGA configuration interface busy
2096 status by the configuration function. This option
2097 will require a board or device specific function to
2102 If defined, a function that provides delays in the FPGA
2103 configuration driver.
2105 CONFIG_SYS_FPGA_CHECK_CTRLC
2106 Allow Control-C to interrupt FPGA configuration
2108 CONFIG_SYS_FPGA_CHECK_ERROR
2110 Check for configuration errors during FPGA bitfile
2111 loading. For example, abort during Virtex II
2112 configuration if the INIT_B line goes low (which
2113 indicated a CRC error).
2115 CONFIG_SYS_FPGA_WAIT_INIT
2117 Maximum time to wait for the INIT_B line to deassert
2118 after PROB_B has been deasserted during a Virtex II
2119 FPGA configuration sequence. The default time is 500
2122 CONFIG_SYS_FPGA_WAIT_BUSY
2124 Maximum time to wait for BUSY to deassert during
2125 Virtex II FPGA configuration. The default is 5 ms.
2127 CONFIG_SYS_FPGA_WAIT_CONFIG
2129 Time to wait after FPGA configuration. The default is
2132 - Configuration Management:
2135 If defined, this string will be added to the U-Boot
2136 version information (U_BOOT_VERSION)
2138 - Vendor Parameter Protection:
2140 U-Boot considers the values of the environment
2141 variables "serial#" (Board Serial Number) and
2142 "ethaddr" (Ethernet Address) to be parameters that
2143 are set once by the board vendor / manufacturer, and
2144 protects these variables from casual modification by
2145 the user. Once set, these variables are read-only,
2146 and write or delete attempts are rejected. You can
2147 change this behaviour:
2149 If CONFIG_ENV_OVERWRITE is #defined in your config
2150 file, the write protection for vendor parameters is
2151 completely disabled. Anybody can change or delete
2154 Alternatively, if you #define _both_ CONFIG_ETHADDR
2155 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2156 Ethernet address is installed in the environment,
2157 which can be changed exactly ONCE by the user. [The
2158 serial# is unaffected by this, i. e. it remains
2164 Define this variable to enable the reservation of
2165 "protected RAM", i. e. RAM which is not overwritten
2166 by U-Boot. Define CONFIG_PRAM to hold the number of
2167 kB you want to reserve for pRAM. You can overwrite
2168 this default value by defining an environment
2169 variable "pram" to the number of kB you want to
2170 reserve. Note that the board info structure will
2171 still show the full amount of RAM. If pRAM is
2172 reserved, a new environment variable "mem" will
2173 automatically be defined to hold the amount of
2174 remaining RAM in a form that can be passed as boot
2175 argument to Linux, for instance like that:
2177 setenv bootargs ... mem=\${mem}
2180 This way you can tell Linux not to use this memory,
2181 either, which results in a memory region that will
2182 not be affected by reboots.
2184 *WARNING* If your board configuration uses automatic
2185 detection of the RAM size, you must make sure that
2186 this memory test is non-destructive. So far, the
2187 following board configurations are known to be
2190 IVMS8, IVML24, SPD8xx, TQM8xxL,
2191 HERMES, IP860, RPXlite, LWMON,
2197 Define this variable to stop the system in case of a
2198 fatal error, so that you have to reset it manually.
2199 This is probably NOT a good idea for an embedded
2200 system where you want the system to reboot
2201 automatically as fast as possible, but it may be
2202 useful during development since you can try to debug
2203 the conditions that lead to the situation.
2205 CONFIG_NET_RETRY_COUNT
2207 This variable defines the number of retries for
2208 network operations like ARP, RARP, TFTP, or BOOTP
2209 before giving up the operation. If not defined, a
2210 default value of 5 is used.
2214 Timeout waiting for an ARP reply in milliseconds.
2218 Timeout in milliseconds used in NFS protocol.
2219 If you encounter "ERROR: Cannot umount" in nfs command,
2220 try longer timeout such as
2221 #define CONFIG_NFS_TIMEOUT 10000UL
2223 - Command Interpreter:
2224 CONFIG_AUTO_COMPLETE
2226 Enable auto completion of commands using TAB.
2228 Note that this feature has NOT been implemented yet
2229 for the "hush" shell.
2232 CONFIG_SYS_HUSH_PARSER
2234 Define this variable to enable the "hush" shell (from
2235 Busybox) as command line interpreter, thus enabling
2236 powerful command line syntax like
2237 if...then...else...fi conditionals or `&&' and '||'
2238 constructs ("shell scripts").
2240 If undefined, you get the old, much simpler behaviour
2241 with a somewhat smaller memory footprint.
2244 CONFIG_SYS_PROMPT_HUSH_PS2
2246 This defines the secondary prompt string, which is
2247 printed when the command interpreter needs more input
2248 to complete a command. Usually "> ".
2252 In the current implementation, the local variables
2253 space and global environment variables space are
2254 separated. Local variables are those you define by
2255 simply typing `name=value'. To access a local
2256 variable later on, you have write `$name' or
2257 `${name}'; to execute the contents of a variable
2258 directly type `$name' at the command prompt.
2260 Global environment variables are those you use
2261 setenv/printenv to work with. To run a command stored
2262 in such a variable, you need to use the run command,
2263 and you must not use the '$' sign to access them.
2265 To store commands and special characters in a
2266 variable, please use double quotation marks
2267 surrounding the whole text of the variable, instead
2268 of the backslashes before semicolons and special
2271 - Commandline Editing and History:
2272 CONFIG_CMDLINE_EDITING
2274 Enable editing and History functions for interactive
2275 commandline input operations
2277 - Default Environment:
2278 CONFIG_EXTRA_ENV_SETTINGS
2280 Define this to contain any number of null terminated
2281 strings (variable = value pairs) that will be part of
2282 the default environment compiled into the boot image.
2284 For example, place something like this in your
2285 board's config file:
2287 #define CONFIG_EXTRA_ENV_SETTINGS \
2291 Warning: This method is based on knowledge about the
2292 internal format how the environment is stored by the
2293 U-Boot code. This is NOT an official, exported
2294 interface! Although it is unlikely that this format
2295 will change soon, there is no guarantee either.
2296 You better know what you are doing here.
2298 Note: overly (ab)use of the default environment is
2299 discouraged. Make sure to check other ways to preset
2300 the environment like the "source" command or the
2303 CONFIG_ENV_VARS_UBOOT_CONFIG
2305 Define this in order to add variables describing the
2306 U-Boot build configuration to the default environment.
2307 These will be named arch, cpu, board, vendor, and soc.
2309 Enabling this option will cause the following to be defined:
2317 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2319 Define this in order to add variables describing certain
2320 run-time determined information about the hardware to the
2321 environment. These will be named board_name, board_rev.
2323 - DataFlash Support:
2324 CONFIG_HAS_DATAFLASH
2326 Defining this option enables DataFlash features and
2327 allows to read/write in Dataflash via the standard
2330 - Serial Flash support
2333 Defining this option enables SPI flash commands
2334 'sf probe/read/write/erase/update'.
2336 Usage requires an initial 'probe' to define the serial
2337 flash parameters, followed by read/write/erase/update
2340 The following defaults may be provided by the platform
2341 to handle the common case when only a single serial
2342 flash is present on the system.
2344 CONFIG_SF_DEFAULT_BUS Bus identifier
2345 CONFIG_SF_DEFAULT_CS Chip-select
2346 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2347 CONFIG_SF_DEFAULT_SPEED in Hz
2349 - SystemACE Support:
2352 Adding this option adds support for Xilinx SystemACE
2353 chips attached via some sort of local bus. The address
2354 of the chip must also be defined in the
2355 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2357 #define CONFIG_SYSTEMACE
2358 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2360 When SystemACE support is added, the "ace" device type
2361 becomes available to the fat commands, i.e. fatls.
2363 - TFTP Fixed UDP Port:
2366 If this is defined, the environment variable tftpsrcp
2367 is used to supply the TFTP UDP source port value.
2368 If tftpsrcp isn't defined, the normal pseudo-random port
2369 number generator is used.
2371 Also, the environment variable tftpdstp is used to supply
2372 the TFTP UDP destination port value. If tftpdstp isn't
2373 defined, the normal port 69 is used.
2375 The purpose for tftpsrcp is to allow a TFTP server to
2376 blindly start the TFTP transfer using the pre-configured
2377 target IP address and UDP port. This has the effect of
2378 "punching through" the (Windows XP) firewall, allowing
2379 the remainder of the TFTP transfer to proceed normally.
2380 A better solution is to properly configure the firewall,
2381 but sometimes that is not allowed.
2383 - Show boot progress:
2384 CONFIG_SHOW_BOOT_PROGRESS
2386 Defining this option allows to add some board-
2387 specific code (calling a user-provided function
2388 "show_boot_progress(int)") that enables you to show
2389 the system's boot progress on some display (for
2390 example, some LED's) on your board. At the moment,
2391 the following checkpoints are implemented:
2393 - Detailed boot stage timing
2395 Define this option to get detailed timing of each stage
2396 of the boot process.
2398 CONFIG_BOOTSTAGE_USER_COUNT
2399 This is the number of available user bootstage records.
2400 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2401 a new ID will be allocated from this stash. If you exceed
2402 the limit, recording will stop.
2404 CONFIG_BOOTSTAGE_REPORT
2405 Define this to print a report before boot, similar to this:
2407 Timer summary in microseconds:
2410 3,575,678 3,575,678 board_init_f start
2411 3,575,695 17 arch_cpu_init A9
2412 3,575,777 82 arch_cpu_init done
2413 3,659,598 83,821 board_init_r start
2414 3,910,375 250,777 main_loop
2415 29,916,167 26,005,792 bootm_start
2416 30,361,327 445,160 start_kernel
2418 CONFIG_CMD_BOOTSTAGE
2419 Add a 'bootstage' command which supports printing a report
2420 and un/stashing of bootstage data.
2422 CONFIG_BOOTSTAGE_FDT
2423 Stash the bootstage information in the FDT. A root 'bootstage'
2424 node is created with each bootstage id as a child. Each child
2425 has a 'name' property and either 'mark' containing the
2426 mark time in microsecond, or 'accum' containing the
2427 accumulated time for that bootstage id in microseconds.
2432 name = "board_init_f";
2441 Code in the Linux kernel can find this in /proc/devicetree.
2443 Legacy uImage format:
2446 1 common/cmd_bootm.c before attempting to boot an image
2447 -1 common/cmd_bootm.c Image header has bad magic number
2448 2 common/cmd_bootm.c Image header has correct magic number
2449 -2 common/cmd_bootm.c Image header has bad checksum
2450 3 common/cmd_bootm.c Image header has correct checksum
2451 -3 common/cmd_bootm.c Image data has bad checksum
2452 4 common/cmd_bootm.c Image data has correct checksum
2453 -4 common/cmd_bootm.c Image is for unsupported architecture
2454 5 common/cmd_bootm.c Architecture check OK
2455 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2456 6 common/cmd_bootm.c Image Type check OK
2457 -6 common/cmd_bootm.c gunzip uncompression error
2458 -7 common/cmd_bootm.c Unimplemented compression type
2459 7 common/cmd_bootm.c Uncompression OK
2460 8 common/cmd_bootm.c No uncompress/copy overwrite error
2461 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2463 9 common/image.c Start initial ramdisk verification
2464 -10 common/image.c Ramdisk header has bad magic number
2465 -11 common/image.c Ramdisk header has bad checksum
2466 10 common/image.c Ramdisk header is OK
2467 -12 common/image.c Ramdisk data has bad checksum
2468 11 common/image.c Ramdisk data has correct checksum
2469 12 common/image.c Ramdisk verification complete, start loading
2470 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2471 13 common/image.c Start multifile image verification
2472 14 common/image.c No initial ramdisk, no multifile, continue.
2474 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2476 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2477 -31 post/post.c POST test failed, detected by post_output_backlog()
2478 -32 post/post.c POST test failed, detected by post_run_single()
2480 34 common/cmd_doc.c before loading a Image from a DOC device
2481 -35 common/cmd_doc.c Bad usage of "doc" command
2482 35 common/cmd_doc.c correct usage of "doc" command
2483 -36 common/cmd_doc.c No boot device
2484 36 common/cmd_doc.c correct boot device
2485 -37 common/cmd_doc.c Unknown Chip ID on boot device
2486 37 common/cmd_doc.c correct chip ID found, device available
2487 -38 common/cmd_doc.c Read Error on boot device
2488 38 common/cmd_doc.c reading Image header from DOC device OK
2489 -39 common/cmd_doc.c Image header has bad magic number
2490 39 common/cmd_doc.c Image header has correct magic number
2491 -40 common/cmd_doc.c Error reading Image from DOC device
2492 40 common/cmd_doc.c Image header has correct magic number
2493 41 common/cmd_ide.c before loading a Image from a IDE device
2494 -42 common/cmd_ide.c Bad usage of "ide" command
2495 42 common/cmd_ide.c correct usage of "ide" command
2496 -43 common/cmd_ide.c No boot device
2497 43 common/cmd_ide.c boot device found
2498 -44 common/cmd_ide.c Device not available
2499 44 common/cmd_ide.c Device available
2500 -45 common/cmd_ide.c wrong partition selected
2501 45 common/cmd_ide.c partition selected
2502 -46 common/cmd_ide.c Unknown partition table
2503 46 common/cmd_ide.c valid partition table found
2504 -47 common/cmd_ide.c Invalid partition type
2505 47 common/cmd_ide.c correct partition type
2506 -48 common/cmd_ide.c Error reading Image Header on boot device
2507 48 common/cmd_ide.c reading Image Header from IDE device OK
2508 -49 common/cmd_ide.c Image header has bad magic number
2509 49 common/cmd_ide.c Image header has correct magic number
2510 -50 common/cmd_ide.c Image header has bad checksum
2511 50 common/cmd_ide.c Image header has correct checksum
2512 -51 common/cmd_ide.c Error reading Image from IDE device
2513 51 common/cmd_ide.c reading Image from IDE device OK
2514 52 common/cmd_nand.c before loading a Image from a NAND device
2515 -53 common/cmd_nand.c Bad usage of "nand" command
2516 53 common/cmd_nand.c correct usage of "nand" command
2517 -54 common/cmd_nand.c No boot device
2518 54 common/cmd_nand.c boot device found
2519 -55 common/cmd_nand.c Unknown Chip ID on boot device
2520 55 common/cmd_nand.c correct chip ID found, device available
2521 -56 common/cmd_nand.c Error reading Image Header on boot device
2522 56 common/cmd_nand.c reading Image Header from NAND device OK
2523 -57 common/cmd_nand.c Image header has bad magic number
2524 57 common/cmd_nand.c Image header has correct magic number
2525 -58 common/cmd_nand.c Error reading Image from NAND device
2526 58 common/cmd_nand.c reading Image from NAND device OK
2528 -60 common/env_common.c Environment has a bad CRC, using default
2530 64 net/eth.c starting with Ethernet configuration.
2531 -64 net/eth.c no Ethernet found.
2532 65 net/eth.c Ethernet found.
2534 -80 common/cmd_net.c usage wrong
2535 80 common/cmd_net.c before calling NetLoop()
2536 -81 common/cmd_net.c some error in NetLoop() occurred
2537 81 common/cmd_net.c NetLoop() back without error
2538 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2539 82 common/cmd_net.c trying automatic boot
2540 83 common/cmd_net.c running "source" command
2541 -83 common/cmd_net.c some error in automatic boot or "source" command
2542 84 common/cmd_net.c end without errors
2547 100 common/cmd_bootm.c Kernel FIT Image has correct format
2548 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2549 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2550 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2551 102 common/cmd_bootm.c Kernel unit name specified
2552 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2553 103 common/cmd_bootm.c Found configuration node
2554 104 common/cmd_bootm.c Got kernel subimage node offset
2555 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2556 105 common/cmd_bootm.c Kernel subimage hash verification OK
2557 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2558 106 common/cmd_bootm.c Architecture check OK
2559 -106 common/cmd_bootm.c Kernel subimage has wrong type
2560 107 common/cmd_bootm.c Kernel subimage type OK
2561 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2562 108 common/cmd_bootm.c Got kernel subimage data/size
2563 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2564 -109 common/cmd_bootm.c Can't get kernel subimage type
2565 -110 common/cmd_bootm.c Can't get kernel subimage comp
2566 -111 common/cmd_bootm.c Can't get kernel subimage os
2567 -112 common/cmd_bootm.c Can't get kernel subimage load address
2568 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2570 120 common/image.c Start initial ramdisk verification
2571 -120 common/image.c Ramdisk FIT image has incorrect format
2572 121 common/image.c Ramdisk FIT image has correct format
2573 122 common/image.c No ramdisk subimage unit name, using configuration
2574 -122 common/image.c Can't get configuration for ramdisk subimage
2575 123 common/image.c Ramdisk unit name specified
2576 -124 common/image.c Can't get ramdisk subimage node offset
2577 125 common/image.c Got ramdisk subimage node offset
2578 -125 common/image.c Ramdisk subimage hash verification failed
2579 126 common/image.c Ramdisk subimage hash verification OK
2580 -126 common/image.c Ramdisk subimage for unsupported architecture
2581 127 common/image.c Architecture check OK
2582 -127 common/image.c Can't get ramdisk subimage data/size
2583 128 common/image.c Got ramdisk subimage data/size
2584 129 common/image.c Can't get ramdisk load address
2585 -129 common/image.c Got ramdisk load address
2587 -130 common/cmd_doc.c Incorrect FIT image format
2588 131 common/cmd_doc.c FIT image format OK
2590 -140 common/cmd_ide.c Incorrect FIT image format
2591 141 common/cmd_ide.c FIT image format OK
2593 -150 common/cmd_nand.c Incorrect FIT image format
2594 151 common/cmd_nand.c FIT image format OK
2596 - Standalone program support:
2597 CONFIG_STANDALONE_LOAD_ADDR
2599 This option defines a board specific value for the
2600 address where standalone program gets loaded, thus
2601 overwriting the architecture dependent default
2604 - Frame Buffer Address:
2607 Define CONFIG_FB_ADDR if you want to use specific
2608 address for frame buffer.
2609 Then system will reserve the frame buffer address to
2610 defined address instead of lcd_setmem (this function
2611 grabs the memory for frame buffer by panel's size).
2613 Please see board_init_f function.
2615 - Automatic software updates via TFTP server
2617 CONFIG_UPDATE_TFTP_CNT_MAX
2618 CONFIG_UPDATE_TFTP_MSEC_MAX
2620 These options enable and control the auto-update feature;
2621 for a more detailed description refer to doc/README.update.
2623 - MTD Support (mtdparts command, UBI support)
2626 Adds the MTD device infrastructure from the Linux kernel.
2627 Needed for mtdparts command support.
2629 CONFIG_MTD_PARTITIONS
2631 Adds the MTD partitioning infrastructure from the Linux
2632 kernel. Needed for UBI support.
2636 Enable building of SPL globally.
2639 LDSCRIPT for linking the SPL binary.
2642 Maximum binary size (text, data and rodata) of the SPL binary.
2644 CONFIG_SPL_TEXT_BASE
2645 TEXT_BASE for linking the SPL binary.
2647 CONFIG_SPL_BSS_START_ADDR
2648 Link address for the BSS within the SPL binary.
2650 CONFIG_SPL_BSS_MAX_SIZE
2651 Maximum binary size of the BSS section of the SPL binary.
2654 Adress of the start of the stack SPL will use
2656 CONFIG_SYS_SPL_MALLOC_START
2657 Starting address of the malloc pool used in SPL.
2659 CONFIG_SYS_SPL_MALLOC_SIZE
2660 The size of the malloc pool used in SPL.
2662 CONFIG_SPL_FRAMEWORK
2663 Enable the SPL framework under common/. This framework
2664 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2665 NAND loading of the Linux Kernel.
2667 CONFIG_SPL_DISPLAY_PRINT
2668 For ARM, enable an optional function to print more information
2669 about the running system.
2671 CONFIG_SPL_LIBCOMMON_SUPPORT
2672 Support for common/libcommon.o in SPL binary
2674 CONFIG_SPL_LIBDISK_SUPPORT
2675 Support for disk/libdisk.o in SPL binary
2677 CONFIG_SPL_I2C_SUPPORT
2678 Support for drivers/i2c/libi2c.o in SPL binary
2680 CONFIG_SPL_GPIO_SUPPORT
2681 Support for drivers/gpio/libgpio.o in SPL binary
2683 CONFIG_SPL_MMC_SUPPORT
2684 Support for drivers/mmc/libmmc.o in SPL binary
2686 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2687 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2688 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2689 Address, size and partition on the MMC to load U-Boot from
2690 when the MMC is being used in raw mode.
2692 CONFIG_SPL_FAT_SUPPORT
2693 Support for fs/fat/libfat.o in SPL binary
2695 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2696 Filename to read to load U-Boot when reading from FAT
2698 CONFIG_SPL_NAND_SIMPLE
2699 Support for drivers/mtd/nand/libnand.o in SPL binary
2701 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2702 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2703 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2704 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2705 CONFIG_SYS_NAND_ECCBYTES
2706 Defines the size and behavior of the NAND that SPL uses
2707 to read U-Boot with CONFIG_SPL_NAND_SIMPLE
2709 CONFIG_SYS_NAND_U_BOOT_OFFS
2710 Location in NAND for CONFIG_SPL_NAND_SIMPLE to read U-Boot
2713 CONFIG_SYS_NAND_U_BOOT_START
2714 Location in memory for CONFIG_SPL_NAND_SIMPLE to load U-Boot
2717 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2718 Define this if you need to first read the OOB and then the
2719 data. This is used for example on davinci plattforms.
2721 CONFIG_SPL_OMAP3_ID_NAND
2722 Support for an OMAP3-specific set of functions to return the
2723 ID and MFR of the first attached NAND chip, if present.
2725 CONFIG_SPL_SERIAL_SUPPORT
2726 Support for drivers/serial/libserial.o in SPL binary
2728 CONFIG_SPL_SPI_FLASH_SUPPORT
2729 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2731 CONFIG_SPL_SPI_SUPPORT
2732 Support for drivers/spi/libspi.o in SPL binary
2734 CONFIG_SPL_RAM_DEVICE
2735 Support for running image already present in ram, in SPL binary
2737 CONFIG_SPL_LIBGENERIC_SUPPORT
2738 Support for lib/libgeneric.o in SPL binary
2743 [so far only for SMDK2400 boards]
2745 - Modem support enable:
2746 CONFIG_MODEM_SUPPORT
2748 - RTS/CTS Flow control enable:
2751 - Modem debug support:
2752 CONFIG_MODEM_SUPPORT_DEBUG
2754 Enables debugging stuff (char screen[1024], dbg())
2755 for modem support. Useful only with BDI2000.
2757 - Interrupt support (PPC):
2759 There are common interrupt_init() and timer_interrupt()
2760 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2761 for CPU specific initialization. interrupt_init_cpu()
2762 should set decrementer_count to appropriate value. If
2763 CPU resets decrementer automatically after interrupt
2764 (ppc4xx) it should set decrementer_count to zero.
2765 timer_interrupt() calls timer_interrupt_cpu() for CPU
2766 specific handling. If board has watchdog / status_led
2767 / other_activity_monitor it works automatically from
2768 general timer_interrupt().
2772 In the target system modem support is enabled when a
2773 specific key (key combination) is pressed during
2774 power-on. Otherwise U-Boot will boot normally
2775 (autoboot). The key_pressed() function is called from
2776 board_init(). Currently key_pressed() is a dummy
2777 function, returning 1 and thus enabling modem
2780 If there are no modem init strings in the
2781 environment, U-Boot proceed to autoboot; the
2782 previous output (banner, info printfs) will be
2785 See also: doc/README.Modem
2787 Board initialization settings:
2788 ------------------------------
2790 During Initialization u-boot calls a number of board specific functions
2791 to allow the preparation of board specific prerequisites, e.g. pin setup
2792 before drivers are initialized. To enable these callbacks the
2793 following configuration macros have to be defined. Currently this is
2794 architecture specific, so please check arch/your_architecture/lib/board.c
2795 typically in board_init_f() and board_init_r().
2797 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2798 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2799 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2800 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2802 Configuration Settings:
2803 -----------------------
2805 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2806 undefine this when you're short of memory.
2808 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2809 width of the commands listed in the 'help' command output.
2811 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2812 prompt for user input.
2814 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2816 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2818 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2820 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2821 the application (usually a Linux kernel) when it is
2824 - CONFIG_SYS_BAUDRATE_TABLE:
2825 List of legal baudrate settings for this board.
2827 - CONFIG_SYS_CONSOLE_INFO_QUIET
2828 Suppress display of console information at boot.
2830 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2831 If the board specific function
2832 extern int overwrite_console (void);
2833 returns 1, the stdin, stderr and stdout are switched to the
2834 serial port, else the settings in the environment are used.
2836 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2837 Enable the call to overwrite_console().
2839 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2840 Enable overwrite of previous console environment settings.
2842 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2843 Begin and End addresses of the area used by the
2846 - CONFIG_SYS_ALT_MEMTEST:
2847 Enable an alternate, more extensive memory test.
2849 - CONFIG_SYS_MEMTEST_SCRATCH:
2850 Scratch address used by the alternate memory test
2851 You only need to set this if address zero isn't writeable
2853 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2854 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2855 this specified memory area will get subtracted from the top
2856 (end) of RAM and won't get "touched" at all by U-Boot. By
2857 fixing up gd->ram_size the Linux kernel should gets passed
2858 the now "corrected" memory size and won't touch it either.
2859 This should work for arch/ppc and arch/powerpc. Only Linux
2860 board ports in arch/powerpc with bootwrapper support that
2861 recalculate the memory size from the SDRAM controller setup
2862 will have to get fixed in Linux additionally.
2864 This option can be used as a workaround for the 440EPx/GRx
2865 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2868 WARNING: Please make sure that this value is a multiple of
2869 the Linux page size (normally 4k). If this is not the case,
2870 then the end address of the Linux memory will be located at a
2871 non page size aligned address and this could cause major
2874 - CONFIG_SYS_TFTP_LOADADDR:
2875 Default load address for network file downloads
2877 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2878 Enable temporary baudrate change while serial download
2880 - CONFIG_SYS_SDRAM_BASE:
2881 Physical start address of SDRAM. _Must_ be 0 here.
2883 - CONFIG_SYS_MBIO_BASE:
2884 Physical start address of Motherboard I/O (if using a
2887 - CONFIG_SYS_FLASH_BASE:
2888 Physical start address of Flash memory.
2890 - CONFIG_SYS_MONITOR_BASE:
2891 Physical start address of boot monitor code (set by
2892 make config files to be same as the text base address
2893 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2894 CONFIG_SYS_FLASH_BASE when booting from flash.
2896 - CONFIG_SYS_MONITOR_LEN:
2897 Size of memory reserved for monitor code, used to
2898 determine _at_compile_time_ (!) if the environment is
2899 embedded within the U-Boot image, or in a separate
2902 - CONFIG_SYS_MALLOC_LEN:
2903 Size of DRAM reserved for malloc() use.
2905 - CONFIG_SYS_BOOTM_LEN:
2906 Normally compressed uImages are limited to an
2907 uncompressed size of 8 MBytes. If this is not enough,
2908 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2909 to adjust this setting to your needs.
2911 - CONFIG_SYS_BOOTMAPSZ:
2912 Maximum size of memory mapped by the startup code of
2913 the Linux kernel; all data that must be processed by
2914 the Linux kernel (bd_info, boot arguments, FDT blob if
2915 used) must be put below this limit, unless "bootm_low"
2916 enviroment variable is defined and non-zero. In such case
2917 all data for the Linux kernel must be between "bootm_low"
2918 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2919 variable "bootm_mapsize" will override the value of
2920 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2921 then the value in "bootm_size" will be used instead.
2923 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2924 Enable initrd_high functionality. If defined then the
2925 initrd_high feature is enabled and the bootm ramdisk subcommand
2928 - CONFIG_SYS_BOOT_GET_CMDLINE:
2929 Enables allocating and saving kernel cmdline in space between
2930 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2932 - CONFIG_SYS_BOOT_GET_KBD:
2933 Enables allocating and saving a kernel copy of the bd_info in
2934 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2936 - CONFIG_SYS_MAX_FLASH_BANKS:
2937 Max number of Flash memory banks
2939 - CONFIG_SYS_MAX_FLASH_SECT:
2940 Max number of sectors on a Flash chip
2942 - CONFIG_SYS_FLASH_ERASE_TOUT:
2943 Timeout for Flash erase operations (in ms)
2945 - CONFIG_SYS_FLASH_WRITE_TOUT:
2946 Timeout for Flash write operations (in ms)
2948 - CONFIG_SYS_FLASH_LOCK_TOUT
2949 Timeout for Flash set sector lock bit operation (in ms)
2951 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2952 Timeout for Flash clear lock bits operation (in ms)
2954 - CONFIG_SYS_FLASH_PROTECTION
2955 If defined, hardware flash sectors protection is used
2956 instead of U-Boot software protection.
2958 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2960 Enable TFTP transfers directly to flash memory;
2961 without this option such a download has to be
2962 performed in two steps: (1) download to RAM, and (2)
2963 copy from RAM to flash.
2965 The two-step approach is usually more reliable, since
2966 you can check if the download worked before you erase
2967 the flash, but in some situations (when system RAM is
2968 too limited to allow for a temporary copy of the
2969 downloaded image) this option may be very useful.
2971 - CONFIG_SYS_FLASH_CFI:
2972 Define if the flash driver uses extra elements in the
2973 common flash structure for storing flash geometry.
2975 - CONFIG_FLASH_CFI_DRIVER
2976 This option also enables the building of the cfi_flash driver
2977 in the drivers directory
2979 - CONFIG_FLASH_CFI_MTD
2980 This option enables the building of the cfi_mtd driver
2981 in the drivers directory. The driver exports CFI flash
2984 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2985 Use buffered writes to flash.
2987 - CONFIG_FLASH_SPANSION_S29WS_N
2988 s29ws-n MirrorBit flash has non-standard addresses for buffered
2991 - CONFIG_SYS_FLASH_QUIET_TEST
2992 If this option is defined, the common CFI flash doesn't
2993 print it's warning upon not recognized FLASH banks. This
2994 is useful, if some of the configured banks are only
2995 optionally available.
2997 - CONFIG_FLASH_SHOW_PROGRESS
2998 If defined (must be an integer), print out countdown
2999 digits and dots. Recommended value: 45 (9..1) for 80
3000 column displays, 15 (3..1) for 40 column displays.
3002 - CONFIG_SYS_RX_ETH_BUFFER:
3003 Defines the number of Ethernet receive buffers. On some
3004 Ethernet controllers it is recommended to set this value
3005 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3006 buffers can be full shortly after enabling the interface
3007 on high Ethernet traffic.
3008 Defaults to 4 if not defined.
3010 - CONFIG_ENV_MAX_ENTRIES
3012 Maximum number of entries in the hash table that is used
3013 internally to store the environment settings. The default
3014 setting is supposed to be generous and should work in most
3015 cases. This setting can be used to tune behaviour; see
3016 lib/hashtable.c for details.
3018 The following definitions that deal with the placement and management
3019 of environment data (variable area); in general, we support the
3020 following configurations:
3022 - CONFIG_BUILD_ENVCRC:
3024 Builds up envcrc with the target environment so that external utils
3025 may easily extract it and embed it in final U-Boot images.
3027 - CONFIG_ENV_IS_IN_FLASH:
3029 Define this if the environment is in flash memory.
3031 a) The environment occupies one whole flash sector, which is
3032 "embedded" in the text segment with the U-Boot code. This
3033 happens usually with "bottom boot sector" or "top boot
3034 sector" type flash chips, which have several smaller
3035 sectors at the start or the end. For instance, such a
3036 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3037 such a case you would place the environment in one of the
3038 4 kB sectors - with U-Boot code before and after it. With
3039 "top boot sector" type flash chips, you would put the
3040 environment in one of the last sectors, leaving a gap
3041 between U-Boot and the environment.
3043 - CONFIG_ENV_OFFSET:
3045 Offset of environment data (variable area) to the
3046 beginning of flash memory; for instance, with bottom boot
3047 type flash chips the second sector can be used: the offset
3048 for this sector is given here.
3050 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3054 This is just another way to specify the start address of
3055 the flash sector containing the environment (instead of
3058 - CONFIG_ENV_SECT_SIZE:
3060 Size of the sector containing the environment.
3063 b) Sometimes flash chips have few, equal sized, BIG sectors.
3064 In such a case you don't want to spend a whole sector for
3069 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3070 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3071 of this flash sector for the environment. This saves
3072 memory for the RAM copy of the environment.
3074 It may also save flash memory if you decide to use this
3075 when your environment is "embedded" within U-Boot code,
3076 since then the remainder of the flash sector could be used
3077 for U-Boot code. It should be pointed out that this is
3078 STRONGLY DISCOURAGED from a robustness point of view:
3079 updating the environment in flash makes it always
3080 necessary to erase the WHOLE sector. If something goes
3081 wrong before the contents has been restored from a copy in
3082 RAM, your target system will be dead.
3084 - CONFIG_ENV_ADDR_REDUND
3085 CONFIG_ENV_SIZE_REDUND
3087 These settings describe a second storage area used to hold
3088 a redundant copy of the environment data, so that there is
3089 a valid backup copy in case there is a power failure during
3090 a "saveenv" operation.
3092 BE CAREFUL! Any changes to the flash layout, and some changes to the
3093 source code will make it necessary to adapt <board>/u-boot.lds*
3097 - CONFIG_ENV_IS_IN_NVRAM:
3099 Define this if you have some non-volatile memory device
3100 (NVRAM, battery buffered SRAM) which you want to use for the
3106 These two #defines are used to determine the memory area you
3107 want to use for environment. It is assumed that this memory
3108 can just be read and written to, without any special
3111 BE CAREFUL! The first access to the environment happens quite early
3112 in U-Boot initalization (when we try to get the setting of for the
3113 console baudrate). You *MUST* have mapped your NVRAM area then, or
3116 Please note that even with NVRAM we still use a copy of the
3117 environment in RAM: we could work on NVRAM directly, but we want to
3118 keep settings there always unmodified except somebody uses "saveenv"
3119 to save the current settings.
3122 - CONFIG_ENV_IS_IN_EEPROM:
3124 Use this if you have an EEPROM or similar serial access
3125 device and a driver for it.
3127 - CONFIG_ENV_OFFSET:
3130 These two #defines specify the offset and size of the
3131 environment area within the total memory of your EEPROM.
3133 - CONFIG_SYS_I2C_EEPROM_ADDR:
3134 If defined, specified the chip address of the EEPROM device.
3135 The default address is zero.
3137 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3138 If defined, the number of bits used to address bytes in a
3139 single page in the EEPROM device. A 64 byte page, for example
3140 would require six bits.
3142 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3143 If defined, the number of milliseconds to delay between
3144 page writes. The default is zero milliseconds.
3146 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3147 The length in bytes of the EEPROM memory array address. Note
3148 that this is NOT the chip address length!
3150 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3151 EEPROM chips that implement "address overflow" are ones
3152 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3153 address and the extra bits end up in the "chip address" bit
3154 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3157 Note that we consider the length of the address field to
3158 still be one byte because the extra address bits are hidden
3159 in the chip address.
3161 - CONFIG_SYS_EEPROM_SIZE:
3162 The size in bytes of the EEPROM device.
3164 - CONFIG_ENV_EEPROM_IS_ON_I2C
3165 define this, if you have I2C and SPI activated, and your
3166 EEPROM, which holds the environment, is on the I2C bus.
3168 - CONFIG_I2C_ENV_EEPROM_BUS
3169 if you have an Environment on an EEPROM reached over
3170 I2C muxes, you can define here, how to reach this
3171 EEPROM. For example:
3173 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3175 EEPROM which holds the environment, is reached over
3176 a pca9547 i2c mux with address 0x70, channel 3.
3178 - CONFIG_ENV_IS_IN_DATAFLASH:
3180 Define this if you have a DataFlash memory device which you
3181 want to use for the environment.
3183 - CONFIG_ENV_OFFSET:
3187 These three #defines specify the offset and size of the
3188 environment area within the total memory of your DataFlash placed
3189 at the specified address.
3191 - CONFIG_ENV_IS_IN_REMOTE:
3193 Define this if you have a remote memory space which you
3194 want to use for the local device's environment.
3199 These two #defines specify the address and size of the
3200 environment area within the remote memory space. The
3201 local device can get the environment from remote memory
3202 space by SRIO or PCIE links.
3204 BE CAREFUL! For some special cases, the local device can not use
3205 "saveenv" command. For example, the local device will get the
3206 environment stored in a remote NOR flash by SRIO or PCIE link,
3207 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3209 - CONFIG_ENV_IS_IN_NAND:
3211 Define this if you have a NAND device which you want to use
3212 for the environment.
3214 - CONFIG_ENV_OFFSET:
3217 These two #defines specify the offset and size of the environment
3218 area within the first NAND device. CONFIG_ENV_OFFSET must be
3219 aligned to an erase block boundary.
3221 - CONFIG_ENV_OFFSET_REDUND (optional):
3223 This setting describes a second storage area of CONFIG_ENV_SIZE
3224 size used to hold a redundant copy of the environment data, so
3225 that there is a valid backup copy in case there is a power failure
3226 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3227 aligned to an erase block boundary.
3229 - CONFIG_ENV_RANGE (optional):
3231 Specifies the length of the region in which the environment
3232 can be written. This should be a multiple of the NAND device's
3233 block size. Specifying a range with more erase blocks than
3234 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3235 the range to be avoided.
3237 - CONFIG_ENV_OFFSET_OOB (optional):
3239 Enables support for dynamically retrieving the offset of the
3240 environment from block zero's out-of-band data. The
3241 "nand env.oob" command can be used to record this offset.
3242 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3243 using CONFIG_ENV_OFFSET_OOB.
3245 - CONFIG_NAND_ENV_DST
3247 Defines address in RAM to which the nand_spl code should copy the
3248 environment. If redundant environment is used, it will be copied to
3249 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3251 - CONFIG_SYS_SPI_INIT_OFFSET
3253 Defines offset to the initial SPI buffer area in DPRAM. The
3254 area is used at an early stage (ROM part) if the environment
3255 is configured to reside in the SPI EEPROM: We need a 520 byte
3256 scratch DPRAM area. It is used between the two initialization
3257 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3258 to be a good choice since it makes it far enough from the
3259 start of the data area as well as from the stack pointer.
3261 Please note that the environment is read-only until the monitor
3262 has been relocated to RAM and a RAM copy of the environment has been
3263 created; also, when using EEPROM you will have to use getenv_f()
3264 until then to read environment variables.
3266 The environment is protected by a CRC32 checksum. Before the monitor
3267 is relocated into RAM, as a result of a bad CRC you will be working
3268 with the compiled-in default environment - *silently*!!! [This is
3269 necessary, because the first environment variable we need is the
3270 "baudrate" setting for the console - if we have a bad CRC, we don't
3271 have any device yet where we could complain.]
3273 Note: once the monitor has been relocated, then it will complain if
3274 the default environment is used; a new CRC is computed as soon as you
3275 use the "saveenv" command to store a valid environment.
3277 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3278 Echo the inverted Ethernet link state to the fault LED.
3280 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3281 also needs to be defined.
3283 - CONFIG_SYS_FAULT_MII_ADDR:
3284 MII address of the PHY to check for the Ethernet link state.
3286 - CONFIG_NS16550_MIN_FUNCTIONS:
3287 Define this if you desire to only have use of the NS16550_init
3288 and NS16550_putc functions for the serial driver located at
3289 drivers/serial/ns16550.c. This option is useful for saving
3290 space for already greatly restricted images, including but not
3291 limited to NAND_SPL configurations.
3293 Low Level (hardware related) configuration options:
3294 ---------------------------------------------------
3296 - CONFIG_SYS_CACHELINE_SIZE:
3297 Cache Line Size of the CPU.
3299 - CONFIG_SYS_DEFAULT_IMMR:
3300 Default address of the IMMR after system reset.
3302 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3303 and RPXsuper) to be able to adjust the position of
3304 the IMMR register after a reset.
3306 - CONFIG_SYS_CCSRBAR_DEFAULT:
3307 Default (power-on reset) physical address of CCSR on Freescale
3310 - CONFIG_SYS_CCSRBAR:
3311 Virtual address of CCSR. On a 32-bit build, this is typically
3312 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3314 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3315 for cross-platform code that uses that macro instead.
3317 - CONFIG_SYS_CCSRBAR_PHYS:
3318 Physical address of CCSR. CCSR can be relocated to a new
3319 physical address, if desired. In this case, this macro should
3320 be set to that address. Otherwise, it should be set to the
3321 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3322 is typically relocated on 36-bit builds. It is recommended
3323 that this macro be defined via the _HIGH and _LOW macros:
3325 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3326 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3328 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3329 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3330 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3331 used in assembly code, so it must not contain typecasts or
3332 integer size suffixes (e.g. "ULL").
3334 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3335 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3336 used in assembly code, so it must not contain typecasts or
3337 integer size suffixes (e.g. "ULL").
3339 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3340 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3341 forced to a value that ensures that CCSR is not relocated.
3343 - Floppy Disk Support:
3344 CONFIG_SYS_FDC_DRIVE_NUMBER
3346 the default drive number (default value 0)
3348 CONFIG_SYS_ISA_IO_STRIDE
3350 defines the spacing between FDC chipset registers
3353 CONFIG_SYS_ISA_IO_OFFSET
3355 defines the offset of register from address. It
3356 depends on which part of the data bus is connected to
3357 the FDC chipset. (default value 0)
3359 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3360 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3363 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3364 fdc_hw_init() is called at the beginning of the FDC
3365 setup. fdc_hw_init() must be provided by the board
3366 source code. It is used to make hardware dependant
3370 Most IDE controllers were designed to be connected with PCI
3371 interface. Only few of them were designed for AHB interface.
3372 When software is doing ATA command and data transfer to
3373 IDE devices through IDE-AHB controller, some additional
3374 registers accessing to these kind of IDE-AHB controller
3377 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3378 DO NOT CHANGE unless you know exactly what you're
3379 doing! (11-4) [MPC8xx/82xx systems only]
3381 - CONFIG_SYS_INIT_RAM_ADDR:
3383 Start address of memory area that can be used for
3384 initial data and stack; please note that this must be
3385 writable memory that is working WITHOUT special
3386 initialization, i. e. you CANNOT use normal RAM which
3387 will become available only after programming the
3388 memory controller and running certain initialization
3391 U-Boot uses the following memory types:
3392 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3393 - MPC824X: data cache
3394 - PPC4xx: data cache
3396 - CONFIG_SYS_GBL_DATA_OFFSET:
3398 Offset of the initial data structure in the memory
3399 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3400 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3401 data is located at the end of the available space
3402 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3403 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3404 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3405 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3408 On the MPC824X (or other systems that use the data
3409 cache for initial memory) the address chosen for
3410 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3411 point to an otherwise UNUSED address space between
3412 the top of RAM and the start of the PCI space.
3414 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3416 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3418 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3420 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3422 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3424 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3426 - CONFIG_SYS_OR_TIMING_SDRAM:
3429 - CONFIG_SYS_MAMR_PTA:
3430 periodic timer for refresh
3432 - CONFIG_SYS_DER: Debug Event Register (37-47)
3434 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3435 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3436 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3437 CONFIG_SYS_BR1_PRELIM:
3438 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3440 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3441 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3442 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3443 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3445 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3446 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3447 Machine Mode Register and Memory Periodic Timer
3448 Prescaler definitions (SDRAM timing)
3450 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3451 enable I2C microcode relocation patch (MPC8xx);
3452 define relocation offset in DPRAM [DSP2]
3454 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3455 enable SMC microcode relocation patch (MPC8xx);
3456 define relocation offset in DPRAM [SMC1]
3458 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3459 enable SPI microcode relocation patch (MPC8xx);
3460 define relocation offset in DPRAM [SCC4]
3462 - CONFIG_SYS_USE_OSCCLK:
3463 Use OSCM clock mode on MBX8xx board. Be careful,
3464 wrong setting might damage your board. Read
3465 doc/README.MBX before setting this variable!
3467 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3468 Offset of the bootmode word in DPRAM used by post
3469 (Power On Self Tests). This definition overrides
3470 #define'd default value in commproc.h resp.
3473 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3474 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3475 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3476 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3477 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3478 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3479 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3480 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3481 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3483 - CONFIG_PCI_DISABLE_PCIE:
3484 Disable PCI-Express on systems where it is supported but not
3487 - CONFIG_PCI_ENUM_ONLY
3488 Only scan through and get the devices on the busses.
3489 Don't do any setup work, presumably because someone or
3490 something has already done it, and we don't need to do it
3491 a second time. Useful for platforms that are pre-booted
3492 by coreboot or similar.
3495 Chip has SRIO or not
3498 Board has SRIO 1 port available
3501 Board has SRIO 2 port available
3503 - CONFIG_SYS_SRIOn_MEM_VIRT:
3504 Virtual Address of SRIO port 'n' memory region
3506 - CONFIG_SYS_SRIOn_MEM_PHYS:
3507 Physical Address of SRIO port 'n' memory region
3509 - CONFIG_SYS_SRIOn_MEM_SIZE:
3510 Size of SRIO port 'n' memory region
3512 - CONFIG_SYS_NDFC_16
3513 Defined to tell the NDFC that the NAND chip is using a
3516 - CONFIG_SYS_NDFC_EBC0_CFG
3517 Sets the EBC0_CFG register for the NDFC. If not defined
3518 a default value will be used.
3521 Get DDR timing information from an I2C EEPROM. Common
3522 with pluggable memory modules such as SODIMMs
3525 I2C address of the SPD EEPROM
3527 - CONFIG_SYS_SPD_BUS_NUM
3528 If SPD EEPROM is on an I2C bus other than the first
3529 one, specify here. Note that the value must resolve
3530 to something your driver can deal with.
3532 - CONFIG_SYS_DDR_RAW_TIMING
3533 Get DDR timing information from other than SPD. Common with
3534 soldered DDR chips onboard without SPD. DDR raw timing
3535 parameters are extracted from datasheet and hard-coded into
3536 header files or board specific files.
3538 - CONFIG_FSL_DDR_INTERACTIVE
3539 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3541 - CONFIG_SYS_83XX_DDR_USES_CS0
3542 Only for 83xx systems. If specified, then DDR should
3543 be configured using CS0 and CS1 instead of CS2 and CS3.
3545 - CONFIG_ETHER_ON_FEC[12]
3546 Define to enable FEC[12] on a 8xx series processor.
3548 - CONFIG_FEC[12]_PHY
3549 Define to the hardcoded PHY address which corresponds
3550 to the given FEC; i. e.
3551 #define CONFIG_FEC1_PHY 4
3552 means that the PHY with address 4 is connected to FEC1
3554 When set to -1, means to probe for first available.
3556 - CONFIG_FEC[12]_PHY_NORXERR
3557 The PHY does not have a RXERR line (RMII only).
3558 (so program the FEC to ignore it).
3561 Enable RMII mode for all FECs.
3562 Note that this is a global option, we can't
3563 have one FEC in standard MII mode and another in RMII mode.
3565 - CONFIG_CRC32_VERIFY
3566 Add a verify option to the crc32 command.
3569 => crc32 -v <address> <count> <crc32>
3571 Where address/count indicate a memory area
3572 and crc32 is the correct crc32 which the
3576 Add the "loopw" memory command. This only takes effect if
3577 the memory commands are activated globally (CONFIG_CMD_MEM).
3580 Add the "mdc" and "mwc" memory commands. These are cyclic
3585 This command will print 4 bytes (10,11,12,13) each 500 ms.
3587 => mwc.l 100 12345678 10
3588 This command will write 12345678 to address 100 all 10 ms.
3590 This only takes effect if the memory commands are activated
3591 globally (CONFIG_CMD_MEM).
3593 - CONFIG_SKIP_LOWLEVEL_INIT
3594 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3595 low level initializations (like setting up the memory
3596 controller) are omitted and/or U-Boot does not
3597 relocate itself into RAM.
3599 Normally this variable MUST NOT be defined. The only
3600 exception is when U-Boot is loaded (to RAM) by some
3601 other boot loader or by a debugger which performs
3602 these initializations itself.
3605 Modifies the behaviour of start.S when compiling a loader
3606 that is executed before the actual U-Boot. E.g. when
3607 compiling a NAND SPL.
3609 - CONFIG_USE_ARCH_MEMCPY
3610 CONFIG_USE_ARCH_MEMSET
3611 If these options are used a optimized version of memcpy/memset will
3612 be used if available. These functions may be faster under some
3613 conditions but may increase the binary size.
3615 Freescale QE/FMAN Firmware Support:
3616 -----------------------------------
3618 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3619 loading of "firmware", which is encoded in the QE firmware binary format.
3620 This firmware often needs to be loaded during U-Boot booting, so macros
3621 are used to identify the storage device (NOR flash, SPI, etc) and the address
3624 - CONFIG_SYS_QE_FMAN_FW_ADDR
3625 The address in the storage device where the firmware is located. The
3626 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3629 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3630 The maximum possible size of the firmware. The firmware binary format
3631 has a field that specifies the actual size of the firmware, but it
3632 might not be possible to read any part of the firmware unless some
3633 local storage is allocated to hold the entire firmware first.
3635 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3636 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3637 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3638 virtual address in NOR flash.
3640 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3641 Specifies that QE/FMAN firmware is located in NAND flash.
3642 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3644 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3645 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3646 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3648 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3649 Specifies that QE/FMAN firmware is located on the primary SPI
3650 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3652 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3653 Specifies that QE/FMAN firmware is located in the remote (master)
3654 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3655 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3656 window->master inbound window->master LAW->the ucode address in
3657 master's memory space.
3659 Building the Software:
3660 ======================
3662 Building U-Boot has been tested in several native build environments
3663 and in many different cross environments. Of course we cannot support
3664 all possibly existing versions of cross development tools in all
3665 (potentially obsolete) versions. In case of tool chain problems we
3666 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3667 which is extensively used to build and test U-Boot.
3669 If you are not using a native environment, it is assumed that you
3670 have GNU cross compiling tools available in your path. In this case,
3671 you must set the environment variable CROSS_COMPILE in your shell.
3672 Note that no changes to the Makefile or any other source files are
3673 necessary. For example using the ELDK on a 4xx CPU, please enter:
3675 $ CROSS_COMPILE=ppc_4xx-
3676 $ export CROSS_COMPILE
3678 Note: If you wish to generate Windows versions of the utilities in
3679 the tools directory you can use the MinGW toolchain
3680 (http://www.mingw.org). Set your HOST tools to the MinGW
3681 toolchain and execute 'make tools'. For example:
3683 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3685 Binaries such as tools/mkimage.exe will be created which can
3686 be executed on computers running Windows.
3688 U-Boot is intended to be simple to build. After installing the
3689 sources you must configure U-Boot for one specific board type. This
3694 where "NAME_config" is the name of one of the existing configu-
3695 rations; see boards.cfg for supported names.
3697 Note: for some board special configuration names may exist; check if
3698 additional information is available from the board vendor; for
3699 instance, the TQM823L systems are available without (standard)
3700 or with LCD support. You can select such additional "features"
3701 when choosing the configuration, i. e.
3704 - will configure for a plain TQM823L, i. e. no LCD support
3706 make TQM823L_LCD_config
3707 - will configure for a TQM823L with U-Boot console on LCD
3712 Finally, type "make all", and you should get some working U-Boot
3713 images ready for download to / installation on your system:
3715 - "u-boot.bin" is a raw binary image
3716 - "u-boot" is an image in ELF binary format
3717 - "u-boot.srec" is in Motorola S-Record format
3719 By default the build is performed locally and the objects are saved
3720 in the source directory. One of the two methods can be used to change
3721 this behavior and build U-Boot to some external directory:
3723 1. Add O= to the make command line invocations:
3725 make O=/tmp/build distclean
3726 make O=/tmp/build NAME_config
3727 make O=/tmp/build all
3729 2. Set environment variable BUILD_DIR to point to the desired location:
3731 export BUILD_DIR=/tmp/build
3736 Note that the command line "O=" setting overrides the BUILD_DIR environment
3740 Please be aware that the Makefiles assume you are using GNU make, so
3741 for instance on NetBSD you might need to use "gmake" instead of
3745 If the system board that you have is not listed, then you will need
3746 to port U-Boot to your hardware platform. To do this, follow these
3749 1. Add a new configuration option for your board to the toplevel
3750 "boards.cfg" file, using the existing entries as examples.
3751 Follow the instructions there to keep the boards in order.
3752 2. Create a new directory to hold your board specific code. Add any
3753 files you need. In your board directory, you will need at least
3754 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3755 3. Create a new configuration file "include/configs/<board>.h" for
3757 3. If you're porting U-Boot to a new CPU, then also create a new
3758 directory to hold your CPU specific code. Add any files you need.
3759 4. Run "make <board>_config" with your new name.
3760 5. Type "make", and you should get a working "u-boot.srec" file
3761 to be installed on your target system.
3762 6. Debug and solve any problems that might arise.
3763 [Of course, this last step is much harder than it sounds.]
3766 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3767 ==============================================================
3769 If you have modified U-Boot sources (for instance added a new board
3770 or support for new devices, a new CPU, etc.) you are expected to
3771 provide feedback to the other developers. The feedback normally takes
3772 the form of a "patch", i. e. a context diff against a certain (latest
3773 official or latest in the git repository) version of U-Boot sources.
3775 But before you submit such a patch, please verify that your modifi-
3776 cation did not break existing code. At least make sure that *ALL* of
3777 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3778 just run the "MAKEALL" script, which will configure and build U-Boot
3779 for ALL supported system. Be warned, this will take a while. You can
3780 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3781 environment variable to the script, i. e. to use the ELDK cross tools
3784 CROSS_COMPILE=ppc_8xx- MAKEALL
3786 or to build on a native PowerPC system you can type
3788 CROSS_COMPILE=' ' MAKEALL
3790 When using the MAKEALL script, the default behaviour is to build
3791 U-Boot in the source directory. This location can be changed by
3792 setting the BUILD_DIR environment variable. Also, for each target
3793 built, the MAKEALL script saves two log files (<target>.ERR and
3794 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3795 location can be changed by setting the MAKEALL_LOGDIR environment
3796 variable. For example:
3798 export BUILD_DIR=/tmp/build
3799 export MAKEALL_LOGDIR=/tmp/log
3800 CROSS_COMPILE=ppc_8xx- MAKEALL
3802 With the above settings build objects are saved in the /tmp/build,
3803 log files are saved in the /tmp/log and the source tree remains clean
3804 during the whole build process.
3807 See also "U-Boot Porting Guide" below.
3810 Monitor Commands - Overview:
3811 ============================
3813 go - start application at address 'addr'
3814 run - run commands in an environment variable
3815 bootm - boot application image from memory
3816 bootp - boot image via network using BootP/TFTP protocol
3817 bootz - boot zImage from memory
3818 tftpboot- boot image via network using TFTP protocol
3819 and env variables "ipaddr" and "serverip"
3820 (and eventually "gatewayip")
3821 tftpput - upload a file via network using TFTP protocol
3822 rarpboot- boot image via network using RARP/TFTP protocol
3823 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3824 loads - load S-Record file over serial line
3825 loadb - load binary file over serial line (kermit mode)
3827 mm - memory modify (auto-incrementing)
3828 nm - memory modify (constant address)
3829 mw - memory write (fill)
3831 cmp - memory compare
3832 crc32 - checksum calculation
3833 i2c - I2C sub-system
3834 sspi - SPI utility commands
3835 base - print or set address offset
3836 printenv- print environment variables
3837 setenv - set environment variables
3838 saveenv - save environment variables to persistent storage
3839 protect - enable or disable FLASH write protection
3840 erase - erase FLASH memory
3841 flinfo - print FLASH memory information
3842 bdinfo - print Board Info structure
3843 iminfo - print header information for application image
3844 coninfo - print console devices and informations
3845 ide - IDE sub-system
3846 loop - infinite loop on address range
3847 loopw - infinite write loop on address range
3848 mtest - simple RAM test
3849 icache - enable or disable instruction cache
3850 dcache - enable or disable data cache
3851 reset - Perform RESET of the CPU
3852 echo - echo args to console
3853 version - print monitor version
3854 help - print online help
3855 ? - alias for 'help'
3858 Monitor Commands - Detailed Description:
3859 ========================================
3863 For now: just type "help <command>".
3866 Environment Variables:
3867 ======================
3869 U-Boot supports user configuration using Environment Variables which
3870 can be made persistent by saving to Flash memory.
3872 Environment Variables are set using "setenv", printed using
3873 "printenv", and saved to Flash using "saveenv". Using "setenv"
3874 without a value can be used to delete a variable from the
3875 environment. As long as you don't save the environment you are
3876 working with an in-memory copy. In case the Flash area containing the
3877 environment is erased by accident, a default environment is provided.
3879 Some configuration options can be set using Environment Variables.
3881 List of environment variables (most likely not complete):
3883 baudrate - see CONFIG_BAUDRATE
3885 bootdelay - see CONFIG_BOOTDELAY
3887 bootcmd - see CONFIG_BOOTCOMMAND
3889 bootargs - Boot arguments when booting an RTOS image
3891 bootfile - Name of the image to load with TFTP
3893 bootm_low - Memory range available for image processing in the bootm
3894 command can be restricted. This variable is given as
3895 a hexadecimal number and defines lowest address allowed
3896 for use by the bootm command. See also "bootm_size"
3897 environment variable. Address defined by "bootm_low" is
3898 also the base of the initial memory mapping for the Linux
3899 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3902 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3903 This variable is given as a hexadecimal number and it
3904 defines the size of the memory region starting at base
3905 address bootm_low that is accessible by the Linux kernel
3906 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3907 as the default value if it is defined, and bootm_size is
3910 bootm_size - Memory range available for image processing in the bootm
3911 command can be restricted. This variable is given as
3912 a hexadecimal number and defines the size of the region
3913 allowed for use by the bootm command. See also "bootm_low"
3914 environment variable.
3916 updatefile - Location of the software update file on a TFTP server, used
3917 by the automatic software update feature. Please refer to
3918 documentation in doc/README.update for more details.
3920 autoload - if set to "no" (any string beginning with 'n'),
3921 "bootp" will just load perform a lookup of the
3922 configuration from the BOOTP server, but not try to
3923 load any image using TFTP
3925 autostart - if set to "yes", an image loaded using the "bootp",
3926 "rarpboot", "tftpboot" or "diskboot" commands will
3927 be automatically started (by internally calling
3930 If set to "no", a standalone image passed to the
3931 "bootm" command will be copied to the load address
3932 (and eventually uncompressed), but NOT be started.
3933 This can be used to load and uncompress arbitrary
3936 fdt_high - if set this restricts the maximum address that the
3937 flattened device tree will be copied into upon boot.
3938 For example, if you have a system with 1 GB memory
3939 at physical address 0x10000000, while Linux kernel
3940 only recognizes the first 704 MB as low memory, you
3941 may need to set fdt_high as 0x3C000000 to have the
3942 device tree blob be copied to the maximum address
3943 of the 704 MB low memory, so that Linux kernel can
3944 access it during the boot procedure.
3946 If this is set to the special value 0xFFFFFFFF then
3947 the fdt will not be copied at all on boot. For this
3948 to work it must reside in writable memory, have
3949 sufficient padding on the end of it for u-boot to
3950 add the information it needs into it, and the memory
3951 must be accessible by the kernel.
3953 fdtcontroladdr- if set this is the address of the control flattened
3954 device tree used by U-Boot when CONFIG_OF_CONTROL is
3957 i2cfast - (PPC405GP|PPC405EP only)
3958 if set to 'y' configures Linux I2C driver for fast
3959 mode (400kHZ). This environment variable is used in
3960 initialization code. So, for changes to be effective
3961 it must be saved and board must be reset.
3963 initrd_high - restrict positioning of initrd images:
3964 If this variable is not set, initrd images will be
3965 copied to the highest possible address in RAM; this
3966 is usually what you want since it allows for
3967 maximum initrd size. If for some reason you want to
3968 make sure that the initrd image is loaded below the
3969 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3970 variable to a value of "no" or "off" or "0".
3971 Alternatively, you can set it to a maximum upper
3972 address to use (U-Boot will still check that it
3973 does not overwrite the U-Boot stack and data).
3975 For instance, when you have a system with 16 MB
3976 RAM, and want to reserve 4 MB from use by Linux,
3977 you can do this by adding "mem=12M" to the value of
3978 the "bootargs" variable. However, now you must make
3979 sure that the initrd image is placed in the first
3980 12 MB as well - this can be done with
3982 setenv initrd_high 00c00000
3984 If you set initrd_high to 0xFFFFFFFF, this is an
3985 indication to U-Boot that all addresses are legal
3986 for the Linux kernel, including addresses in flash
3987 memory. In this case U-Boot will NOT COPY the
3988 ramdisk at all. This may be useful to reduce the
3989 boot time on your system, but requires that this
3990 feature is supported by your Linux kernel.
3992 ipaddr - IP address; needed for tftpboot command
3994 loadaddr - Default load address for commands like "bootp",
3995 "rarpboot", "tftpboot", "loadb" or "diskboot"
3997 loads_echo - see CONFIG_LOADS_ECHO
3999 serverip - TFTP server IP address; needed for tftpboot command
4001 bootretry - see CONFIG_BOOT_RETRY_TIME
4003 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4005 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4007 ethprime - controls which interface is used first.
4009 ethact - controls which interface is currently active.
4010 For example you can do the following
4012 => setenv ethact FEC
4013 => ping 192.168.0.1 # traffic sent on FEC
4014 => setenv ethact SCC
4015 => ping 10.0.0.1 # traffic sent on SCC
4017 ethrotate - When set to "no" U-Boot does not go through all
4018 available network interfaces.
4019 It just stays at the currently selected interface.
4021 netretry - When set to "no" each network operation will
4022 either succeed or fail without retrying.
4023 When set to "once" the network operation will
4024 fail when all the available network interfaces
4025 are tried once without success.
4026 Useful on scripts which control the retry operation
4029 npe_ucode - set load address for the NPE microcode
4031 tftpsrcport - If this is set, the value is used for TFTP's
4034 tftpdstport - If this is set, the value is used for TFTP's UDP
4035 destination port instead of the Well Know Port 69.
4037 tftpblocksize - Block size to use for TFTP transfers; if not set,
4038 we use the TFTP server's default block size
4040 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4041 seconds, minimum value is 1000 = 1 second). Defines
4042 when a packet is considered to be lost so it has to
4043 be retransmitted. The default is 5000 = 5 seconds.
4044 Lowering this value may make downloads succeed
4045 faster in networks with high packet loss rates or
4046 with unreliable TFTP servers.
4048 vlan - When set to a value < 4095 the traffic over
4049 Ethernet is encapsulated/received over 802.1q
4052 The following image location variables contain the location of images
4053 used in booting. The "Image" column gives the role of the image and is
4054 not an environment variable name. The other columns are environment
4055 variable names. "File Name" gives the name of the file on a TFTP
4056 server, "RAM Address" gives the location in RAM the image will be
4057 loaded to, and "Flash Location" gives the image's address in NOR
4058 flash or offset in NAND flash.
4060 *Note* - these variables don't have to be defined for all boards, some
4061 boards currenlty use other variables for these purposes, and some
4062 boards use these variables for other purposes.
4064 Image File Name RAM Address Flash Location
4065 ----- --------- ----------- --------------
4066 u-boot u-boot u-boot_addr_r u-boot_addr
4067 Linux kernel bootfile kernel_addr_r kernel_addr
4068 device tree blob fdtfile fdt_addr_r fdt_addr
4069 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4071 The following environment variables may be used and automatically
4072 updated by the network boot commands ("bootp" and "rarpboot"),
4073 depending the information provided by your boot server:
4075 bootfile - see above
4076 dnsip - IP address of your Domain Name Server
4077 dnsip2 - IP address of your secondary Domain Name Server
4078 gatewayip - IP address of the Gateway (Router) to use
4079 hostname - Target hostname
4081 netmask - Subnet Mask
4082 rootpath - Pathname of the root filesystem on the NFS server
4083 serverip - see above
4086 There are two special Environment Variables:
4088 serial# - contains hardware identification information such
4089 as type string and/or serial number
4090 ethaddr - Ethernet address
4092 These variables can be set only once (usually during manufacturing of
4093 the board). U-Boot refuses to delete or overwrite these variables
4094 once they have been set once.
4097 Further special Environment Variables:
4099 ver - Contains the U-Boot version string as printed
4100 with the "version" command. This variable is
4101 readonly (see CONFIG_VERSION_VARIABLE).
4104 Please note that changes to some configuration parameters may take
4105 only effect after the next boot (yes, that's just like Windoze :-).
4108 Command Line Parsing:
4109 =====================
4111 There are two different command line parsers available with U-Boot:
4112 the old "simple" one, and the much more powerful "hush" shell:
4114 Old, simple command line parser:
4115 --------------------------------
4117 - supports environment variables (through setenv / saveenv commands)
4118 - several commands on one line, separated by ';'
4119 - variable substitution using "... ${name} ..." syntax
4120 - special characters ('$', ';') can be escaped by prefixing with '\',
4122 setenv bootcmd bootm \${address}
4123 - You can also escape text by enclosing in single apostrophes, for example:
4124 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4129 - similar to Bourne shell, with control structures like
4130 if...then...else...fi, for...do...done; while...do...done,
4131 until...do...done, ...
4132 - supports environment ("global") variables (through setenv / saveenv
4133 commands) and local shell variables (through standard shell syntax
4134 "name=value"); only environment variables can be used with "run"
4140 (1) If a command line (or an environment variable executed by a "run"
4141 command) contains several commands separated by semicolon, and
4142 one of these commands fails, then the remaining commands will be
4145 (2) If you execute several variables with one call to run (i. e.
4146 calling run with a list of variables as arguments), any failing
4147 command will cause "run" to terminate, i. e. the remaining
4148 variables are not executed.
4150 Note for Redundant Ethernet Interfaces:
4151 =======================================
4153 Some boards come with redundant Ethernet interfaces; U-Boot supports
4154 such configurations and is capable of automatic selection of a
4155 "working" interface when needed. MAC assignment works as follows:
4157 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4158 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4159 "eth1addr" (=>eth1), "eth2addr", ...
4161 If the network interface stores some valid MAC address (for instance
4162 in SROM), this is used as default address if there is NO correspon-
4163 ding setting in the environment; if the corresponding environment
4164 variable is set, this overrides the settings in the card; that means:
4166 o If the SROM has a valid MAC address, and there is no address in the
4167 environment, the SROM's address is used.
4169 o If there is no valid address in the SROM, and a definition in the
4170 environment exists, then the value from the environment variable is
4173 o If both the SROM and the environment contain a MAC address, and
4174 both addresses are the same, this MAC address is used.
4176 o If both the SROM and the environment contain a MAC address, and the
4177 addresses differ, the value from the environment is used and a
4180 o If neither SROM nor the environment contain a MAC address, an error
4183 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4184 will be programmed into hardware as part of the initialization process. This
4185 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4186 The naming convention is as follows:
4187 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4192 U-Boot is capable of booting (and performing other auxiliary operations on)
4193 images in two formats:
4195 New uImage format (FIT)
4196 -----------------------
4198 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4199 to Flattened Device Tree). It allows the use of images with multiple
4200 components (several kernels, ramdisks, etc.), with contents protected by
4201 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4207 Old image format is based on binary files which can be basically anything,
4208 preceded by a special header; see the definitions in include/image.h for
4209 details; basically, the header defines the following image properties:
4211 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4212 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4213 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4214 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4216 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4217 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4218 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4219 * Compression Type (uncompressed, gzip, bzip2)
4225 The header is marked by a special Magic Number, and both the header
4226 and the data portions of the image are secured against corruption by
4233 Although U-Boot should support any OS or standalone application
4234 easily, the main focus has always been on Linux during the design of
4237 U-Boot includes many features that so far have been part of some
4238 special "boot loader" code within the Linux kernel. Also, any
4239 "initrd" images to be used are no longer part of one big Linux image;
4240 instead, kernel and "initrd" are separate images. This implementation
4241 serves several purposes:
4243 - the same features can be used for other OS or standalone
4244 applications (for instance: using compressed images to reduce the
4245 Flash memory footprint)
4247 - it becomes much easier to port new Linux kernel versions because
4248 lots of low-level, hardware dependent stuff are done by U-Boot
4250 - the same Linux kernel image can now be used with different "initrd"
4251 images; of course this also means that different kernel images can
4252 be run with the same "initrd". This makes testing easier (you don't
4253 have to build a new "zImage.initrd" Linux image when you just
4254 change a file in your "initrd"). Also, a field-upgrade of the
4255 software is easier now.
4261 Porting Linux to U-Boot based systems:
4262 ---------------------------------------
4264 U-Boot cannot save you from doing all the necessary modifications to
4265 configure the Linux device drivers for use with your target hardware
4266 (no, we don't intend to provide a full virtual machine interface to
4269 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4271 Just make sure your machine specific header file (for instance
4272 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4273 Information structure as we define in include/asm-<arch>/u-boot.h,
4274 and make sure that your definition of IMAP_ADDR uses the same value
4275 as your U-Boot configuration in CONFIG_SYS_IMMR.
4278 Configuring the Linux kernel:
4279 -----------------------------
4281 No specific requirements for U-Boot. Make sure you have some root
4282 device (initial ramdisk, NFS) for your target system.
4285 Building a Linux Image:
4286 -----------------------
4288 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4289 not used. If you use recent kernel source, a new build target
4290 "uImage" will exist which automatically builds an image usable by
4291 U-Boot. Most older kernels also have support for a "pImage" target,
4292 which was introduced for our predecessor project PPCBoot and uses a
4293 100% compatible format.
4302 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4303 encapsulate a compressed Linux kernel image with header information,
4304 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4306 * build a standard "vmlinux" kernel image (in ELF binary format):
4308 * convert the kernel into a raw binary image:
4310 ${CROSS_COMPILE}-objcopy -O binary \
4311 -R .note -R .comment \
4312 -S vmlinux linux.bin
4314 * compress the binary image:
4318 * package compressed binary image for U-Boot:
4320 mkimage -A ppc -O linux -T kernel -C gzip \
4321 -a 0 -e 0 -n "Linux Kernel Image" \
4322 -d linux.bin.gz uImage
4325 The "mkimage" tool can also be used to create ramdisk images for use
4326 with U-Boot, either separated from the Linux kernel image, or
4327 combined into one file. "mkimage" encapsulates the images with a 64
4328 byte header containing information about target architecture,
4329 operating system, image type, compression method, entry points, time
4330 stamp, CRC32 checksums, etc.
4332 "mkimage" can be called in two ways: to verify existing images and
4333 print the header information, or to build new images.
4335 In the first form (with "-l" option) mkimage lists the information
4336 contained in the header of an existing U-Boot image; this includes
4337 checksum verification:
4339 tools/mkimage -l image
4340 -l ==> list image header information
4342 The second form (with "-d" option) is used to build a U-Boot image
4343 from a "data file" which is used as image payload:
4345 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4346 -n name -d data_file image
4347 -A ==> set architecture to 'arch'
4348 -O ==> set operating system to 'os'
4349 -T ==> set image type to 'type'
4350 -C ==> set compression type 'comp'
4351 -a ==> set load address to 'addr' (hex)
4352 -e ==> set entry point to 'ep' (hex)
4353 -n ==> set image name to 'name'
4354 -d ==> use image data from 'datafile'
4356 Right now, all Linux kernels for PowerPC systems use the same load
4357 address (0x00000000), but the entry point address depends on the
4360 - 2.2.x kernels have the entry point at 0x0000000C,
4361 - 2.3.x and later kernels have the entry point at 0x00000000.
4363 So a typical call to build a U-Boot image would read:
4365 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4366 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4367 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4368 > examples/uImage.TQM850L
4369 Image Name: 2.4.4 kernel for TQM850L
4370 Created: Wed Jul 19 02:34:59 2000
4371 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4372 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4373 Load Address: 0x00000000
4374 Entry Point: 0x00000000
4376 To verify the contents of the image (or check for corruption):
4378 -> tools/mkimage -l examples/uImage.TQM850L
4379 Image Name: 2.4.4 kernel for TQM850L
4380 Created: Wed Jul 19 02:34:59 2000
4381 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4382 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4383 Load Address: 0x00000000
4384 Entry Point: 0x00000000
4386 NOTE: for embedded systems where boot time is critical you can trade
4387 speed for memory and install an UNCOMPRESSED image instead: this
4388 needs more space in Flash, but boots much faster since it does not
4389 need to be uncompressed:
4391 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4392 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4393 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4394 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4395 > examples/uImage.TQM850L-uncompressed
4396 Image Name: 2.4.4 kernel for TQM850L
4397 Created: Wed Jul 19 02:34:59 2000
4398 Image Type: PowerPC Linux Kernel Image (uncompressed)
4399 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4400 Load Address: 0x00000000
4401 Entry Point: 0x00000000
4404 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4405 when your kernel is intended to use an initial ramdisk:
4407 -> tools/mkimage -n 'Simple Ramdisk Image' \
4408 > -A ppc -O linux -T ramdisk -C gzip \
4409 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4410 Image Name: Simple Ramdisk Image
4411 Created: Wed Jan 12 14:01:50 2000
4412 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4413 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4414 Load Address: 0x00000000
4415 Entry Point: 0x00000000
4418 Installing a Linux Image:
4419 -------------------------
4421 To downloading a U-Boot image over the serial (console) interface,
4422 you must convert the image to S-Record format:
4424 objcopy -I binary -O srec examples/image examples/image.srec
4426 The 'objcopy' does not understand the information in the U-Boot
4427 image header, so the resulting S-Record file will be relative to
4428 address 0x00000000. To load it to a given address, you need to
4429 specify the target address as 'offset' parameter with the 'loads'
4432 Example: install the image to address 0x40100000 (which on the
4433 TQM8xxL is in the first Flash bank):
4435 => erase 40100000 401FFFFF
4441 ## Ready for S-Record download ...
4442 ~>examples/image.srec
4443 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4445 15989 15990 15991 15992
4446 [file transfer complete]
4448 ## Start Addr = 0x00000000
4451 You can check the success of the download using the 'iminfo' command;
4452 this includes a checksum verification so you can be sure no data
4453 corruption happened:
4457 ## Checking Image at 40100000 ...
4458 Image Name: 2.2.13 for initrd on TQM850L
4459 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4460 Data Size: 335725 Bytes = 327 kB = 0 MB
4461 Load Address: 00000000
4462 Entry Point: 0000000c
4463 Verifying Checksum ... OK
4469 The "bootm" command is used to boot an application that is stored in
4470 memory (RAM or Flash). In case of a Linux kernel image, the contents
4471 of the "bootargs" environment variable is passed to the kernel as
4472 parameters. You can check and modify this variable using the
4473 "printenv" and "setenv" commands:
4476 => printenv bootargs
4477 bootargs=root=/dev/ram
4479 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4481 => printenv bootargs
4482 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4485 ## Booting Linux kernel at 40020000 ...
4486 Image Name: 2.2.13 for NFS on TQM850L
4487 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4488 Data Size: 381681 Bytes = 372 kB = 0 MB
4489 Load Address: 00000000
4490 Entry Point: 0000000c
4491 Verifying Checksum ... OK
4492 Uncompressing Kernel Image ... OK
4493 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
4494 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4495 time_init: decrementer frequency = 187500000/60
4496 Calibrating delay loop... 49.77 BogoMIPS
4497 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4500 If you want to boot a Linux kernel with initial RAM disk, you pass
4501 the memory addresses of both the kernel and the initrd image (PPBCOOT
4502 format!) to the "bootm" command:
4504 => imi 40100000 40200000
4506 ## Checking Image at 40100000 ...
4507 Image Name: 2.2.13 for initrd on TQM850L
4508 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4509 Data Size: 335725 Bytes = 327 kB = 0 MB
4510 Load Address: 00000000
4511 Entry Point: 0000000c
4512 Verifying Checksum ... OK
4514 ## Checking Image at 40200000 ...
4515 Image Name: Simple Ramdisk Image
4516 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4517 Data Size: 566530 Bytes = 553 kB = 0 MB
4518 Load Address: 00000000
4519 Entry Point: 00000000
4520 Verifying Checksum ... OK
4522 => bootm 40100000 40200000
4523 ## Booting Linux kernel at 40100000 ...
4524 Image Name: 2.2.13 for initrd on TQM850L
4525 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4526 Data Size: 335725 Bytes = 327 kB = 0 MB
4527 Load Address: 00000000
4528 Entry Point: 0000000c
4529 Verifying Checksum ... OK
4530 Uncompressing Kernel Image ... OK
4531 ## Loading RAMDisk Image at 40200000 ...
4532 Image Name: Simple Ramdisk Image
4533 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4534 Data Size: 566530 Bytes = 553 kB = 0 MB
4535 Load Address: 00000000
4536 Entry Point: 00000000
4537 Verifying Checksum ... OK
4538 Loading Ramdisk ... OK
4539 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
4540 Boot arguments: root=/dev/ram
4541 time_init: decrementer frequency = 187500000/60
4542 Calibrating delay loop... 49.77 BogoMIPS
4544 RAMDISK: Compressed image found at block 0
4545 VFS: Mounted root (ext2 filesystem).
4549 Boot Linux and pass a flat device tree:
4552 First, U-Boot must be compiled with the appropriate defines. See the section
4553 titled "Linux Kernel Interface" above for a more in depth explanation. The
4554 following is an example of how to start a kernel and pass an updated
4560 oft=oftrees/mpc8540ads.dtb
4561 => tftp $oftaddr $oft
4562 Speed: 1000, full duplex
4564 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4565 Filename 'oftrees/mpc8540ads.dtb'.
4566 Load address: 0x300000
4569 Bytes transferred = 4106 (100a hex)
4570 => tftp $loadaddr $bootfile
4571 Speed: 1000, full duplex
4573 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4575 Load address: 0x200000
4576 Loading:############
4578 Bytes transferred = 1029407 (fb51f hex)
4583 => bootm $loadaddr - $oftaddr
4584 ## Booting image at 00200000 ...
4585 Image Name: Linux-2.6.17-dirty
4586 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4587 Data Size: 1029343 Bytes = 1005.2 kB
4588 Load Address: 00000000
4589 Entry Point: 00000000
4590 Verifying Checksum ... OK
4591 Uncompressing Kernel Image ... OK
4592 Booting using flat device tree at 0x300000
4593 Using MPC85xx ADS machine description
4594 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4598 More About U-Boot Image Types:
4599 ------------------------------
4601 U-Boot supports the following image types:
4603 "Standalone Programs" are directly runnable in the environment
4604 provided by U-Boot; it is expected that (if they behave
4605 well) you can continue to work in U-Boot after return from
4606 the Standalone Program.
4607 "OS Kernel Images" are usually images of some Embedded OS which
4608 will take over control completely. Usually these programs
4609 will install their own set of exception handlers, device
4610 drivers, set up the MMU, etc. - this means, that you cannot
4611 expect to re-enter U-Boot except by resetting the CPU.
4612 "RAMDisk Images" are more or less just data blocks, and their
4613 parameters (address, size) are passed to an OS kernel that is
4615 "Multi-File Images" contain several images, typically an OS
4616 (Linux) kernel image and one or more data images like
4617 RAMDisks. This construct is useful for instance when you want
4618 to boot over the network using BOOTP etc., where the boot
4619 server provides just a single image file, but you want to get
4620 for instance an OS kernel and a RAMDisk image.
4622 "Multi-File Images" start with a list of image sizes, each
4623 image size (in bytes) specified by an "uint32_t" in network
4624 byte order. This list is terminated by an "(uint32_t)0".
4625 Immediately after the terminating 0 follow the images, one by
4626 one, all aligned on "uint32_t" boundaries (size rounded up to
4627 a multiple of 4 bytes).
4629 "Firmware Images" are binary images containing firmware (like
4630 U-Boot or FPGA images) which usually will be programmed to
4633 "Script files" are command sequences that will be executed by
4634 U-Boot's command interpreter; this feature is especially
4635 useful when you configure U-Boot to use a real shell (hush)
4636 as command interpreter.
4638 Booting the Linux zImage:
4639 -------------------------
4641 On some platforms, it's possible to boot Linux zImage. This is done
4642 using the "bootz" command. The syntax of "bootz" command is the same
4643 as the syntax of "bootm" command.
4645 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4646 kernel with raw initrd images. The syntax is slightly different, the
4647 address of the initrd must be augmented by it's size, in the following
4648 format: "<initrd addres>:<initrd size>".
4654 One of the features of U-Boot is that you can dynamically load and
4655 run "standalone" applications, which can use some resources of
4656 U-Boot like console I/O functions or interrupt services.
4658 Two simple examples are included with the sources:
4663 'examples/hello_world.c' contains a small "Hello World" Demo
4664 application; it is automatically compiled when you build U-Boot.
4665 It's configured to run at address 0x00040004, so you can play with it
4669 ## Ready for S-Record download ...
4670 ~>examples/hello_world.srec
4671 1 2 3 4 5 6 7 8 9 10 11 ...
4672 [file transfer complete]
4674 ## Start Addr = 0x00040004
4676 => go 40004 Hello World! This is a test.
4677 ## Starting application at 0x00040004 ...
4688 Hit any key to exit ...
4690 ## Application terminated, rc = 0x0
4692 Another example, which demonstrates how to register a CPM interrupt
4693 handler with the U-Boot code, can be found in 'examples/timer.c'.
4694 Here, a CPM timer is set up to generate an interrupt every second.
4695 The interrupt service routine is trivial, just printing a '.'
4696 character, but this is just a demo program. The application can be
4697 controlled by the following keys:
4699 ? - print current values og the CPM Timer registers
4700 b - enable interrupts and start timer
4701 e - stop timer and disable interrupts
4702 q - quit application
4705 ## Ready for S-Record download ...
4706 ~>examples/timer.srec
4707 1 2 3 4 5 6 7 8 9 10 11 ...
4708 [file transfer complete]
4710 ## Start Addr = 0x00040004
4713 ## Starting application at 0x00040004 ...
4716 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4719 [q, b, e, ?] Set interval 1000000 us
4722 [q, b, e, ?] ........
4723 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4726 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4729 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4732 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4734 [q, b, e, ?] ...Stopping timer
4736 [q, b, e, ?] ## Application terminated, rc = 0x0
4742 Over time, many people have reported problems when trying to use the
4743 "minicom" terminal emulation program for serial download. I (wd)
4744 consider minicom to be broken, and recommend not to use it. Under
4745 Unix, I recommend to use C-Kermit for general purpose use (and
4746 especially for kermit binary protocol download ("loadb" command), and
4747 use "cu" for S-Record download ("loads" command). See
4748 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4749 for help with kermit.
4752 Nevertheless, if you absolutely want to use it try adding this
4753 configuration to your "File transfer protocols" section:
4755 Name Program Name U/D FullScr IO-Red. Multi
4756 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4757 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4763 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4764 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4766 Building requires a cross environment; it is known to work on
4767 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4768 need gmake since the Makefiles are not compatible with BSD make).
4769 Note that the cross-powerpc package does not install include files;
4770 attempting to build U-Boot will fail because <machine/ansi.h> is
4771 missing. This file has to be installed and patched manually:
4773 # cd /usr/pkg/cross/powerpc-netbsd/include
4775 # ln -s powerpc machine
4776 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4777 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4779 Native builds *don't* work due to incompatibilities between native
4780 and U-Boot include files.
4782 Booting assumes that (the first part of) the image booted is a
4783 stage-2 loader which in turn loads and then invokes the kernel
4784 proper. Loader sources will eventually appear in the NetBSD source
4785 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4786 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4789 Implementation Internals:
4790 =========================
4792 The following is not intended to be a complete description of every
4793 implementation detail. However, it should help to understand the
4794 inner workings of U-Boot and make it easier to port it to custom
4798 Initial Stack, Global Data:
4799 ---------------------------
4801 The implementation of U-Boot is complicated by the fact that U-Boot
4802 starts running out of ROM (flash memory), usually without access to
4803 system RAM (because the memory controller is not initialized yet).
4804 This means that we don't have writable Data or BSS segments, and BSS
4805 is not initialized as zero. To be able to get a C environment working
4806 at all, we have to allocate at least a minimal stack. Implementation
4807 options for this are defined and restricted by the CPU used: Some CPU
4808 models provide on-chip memory (like the IMMR area on MPC8xx and
4809 MPC826x processors), on others (parts of) the data cache can be
4810 locked as (mis-) used as memory, etc.
4812 Chris Hallinan posted a good summary of these issues to the
4813 U-Boot mailing list:
4815 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4816 From: "Chris Hallinan" <clh@net1plus.com>
4817 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4820 Correct me if I'm wrong, folks, but the way I understand it
4821 is this: Using DCACHE as initial RAM for Stack, etc, does not
4822 require any physical RAM backing up the cache. The cleverness
4823 is that the cache is being used as a temporary supply of
4824 necessary storage before the SDRAM controller is setup. It's
4825 beyond the scope of this list to explain the details, but you
4826 can see how this works by studying the cache architecture and
4827 operation in the architecture and processor-specific manuals.
4829 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4830 is another option for the system designer to use as an
4831 initial stack/RAM area prior to SDRAM being available. Either
4832 option should work for you. Using CS 4 should be fine if your
4833 board designers haven't used it for something that would
4834 cause you grief during the initial boot! It is frequently not
4837 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4838 with your processor/board/system design. The default value
4839 you will find in any recent u-boot distribution in
4840 walnut.h should work for you. I'd set it to a value larger
4841 than your SDRAM module. If you have a 64MB SDRAM module, set
4842 it above 400_0000. Just make sure your board has no resources
4843 that are supposed to respond to that address! That code in
4844 start.S has been around a while and should work as is when
4845 you get the config right.
4850 It is essential to remember this, since it has some impact on the C
4851 code for the initialization procedures:
4853 * Initialized global data (data segment) is read-only. Do not attempt
4856 * Do not use any uninitialized global data (or implicitely initialized
4857 as zero data - BSS segment) at all - this is undefined, initiali-
4858 zation is performed later (when relocating to RAM).
4860 * Stack space is very limited. Avoid big data buffers or things like
4863 Having only the stack as writable memory limits means we cannot use
4864 normal global data to share information beween the code. But it
4865 turned out that the implementation of U-Boot can be greatly
4866 simplified by making a global data structure (gd_t) available to all
4867 functions. We could pass a pointer to this data as argument to _all_
4868 functions, but this would bloat the code. Instead we use a feature of
4869 the GCC compiler (Global Register Variables) to share the data: we
4870 place a pointer (gd) to the global data into a register which we
4871 reserve for this purpose.
4873 When choosing a register for such a purpose we are restricted by the
4874 relevant (E)ABI specifications for the current architecture, and by
4875 GCC's implementation.
4877 For PowerPC, the following registers have specific use:
4879 R2: reserved for system use
4880 R3-R4: parameter passing and return values
4881 R5-R10: parameter passing
4882 R13: small data area pointer
4886 (U-Boot also uses R12 as internal GOT pointer. r12
4887 is a volatile register so r12 needs to be reset when
4888 going back and forth between asm and C)
4890 ==> U-Boot will use R2 to hold a pointer to the global data
4892 Note: on PPC, we could use a static initializer (since the
4893 address of the global data structure is known at compile time),
4894 but it turned out that reserving a register results in somewhat
4895 smaller code - although the code savings are not that big (on
4896 average for all boards 752 bytes for the whole U-Boot image,
4897 624 text + 127 data).
4899 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4900 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4902 ==> U-Boot will use P3 to hold a pointer to the global data
4904 On ARM, the following registers are used:
4906 R0: function argument word/integer result
4907 R1-R3: function argument word
4909 R10: stack limit (used only if stack checking if enabled)
4910 R11: argument (frame) pointer
4911 R12: temporary workspace
4914 R15: program counter
4916 ==> U-Boot will use R8 to hold a pointer to the global data
4918 On Nios II, the ABI is documented here:
4919 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4921 ==> U-Boot will use gp to hold a pointer to the global data
4923 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4924 to access small data sections, so gp is free.
4926 On NDS32, the following registers are used:
4928 R0-R1: argument/return
4930 R15: temporary register for assembler
4931 R16: trampoline register
4932 R28: frame pointer (FP)
4933 R29: global pointer (GP)
4934 R30: link register (LP)
4935 R31: stack pointer (SP)
4936 PC: program counter (PC)
4938 ==> U-Boot will use R10 to hold a pointer to the global data
4940 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4941 or current versions of GCC may "optimize" the code too much.
4946 U-Boot runs in system state and uses physical addresses, i.e. the
4947 MMU is not used either for address mapping nor for memory protection.
4949 The available memory is mapped to fixed addresses using the memory
4950 controller. In this process, a contiguous block is formed for each
4951 memory type (Flash, SDRAM, SRAM), even when it consists of several
4952 physical memory banks.
4954 U-Boot is installed in the first 128 kB of the first Flash bank (on
4955 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4956 booting and sizing and initializing DRAM, the code relocates itself
4957 to the upper end of DRAM. Immediately below the U-Boot code some
4958 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4959 configuration setting]. Below that, a structure with global Board
4960 Info data is placed, followed by the stack (growing downward).
4962 Additionally, some exception handler code is copied to the low 8 kB
4963 of DRAM (0x00000000 ... 0x00001FFF).
4965 So a typical memory configuration with 16 MB of DRAM could look like
4968 0x0000 0000 Exception Vector code
4971 0x0000 2000 Free for Application Use
4977 0x00FB FF20 Monitor Stack (Growing downward)
4978 0x00FB FFAC Board Info Data and permanent copy of global data
4979 0x00FC 0000 Malloc Arena
4982 0x00FE 0000 RAM Copy of Monitor Code
4983 ... eventually: LCD or video framebuffer
4984 ... eventually: pRAM (Protected RAM - unchanged by reset)
4985 0x00FF FFFF [End of RAM]
4988 System Initialization:
4989 ----------------------
4991 In the reset configuration, U-Boot starts at the reset entry point
4992 (on most PowerPC systems at address 0x00000100). Because of the reset
4993 configuration for CS0# this is a mirror of the onboard Flash memory.
4994 To be able to re-map memory U-Boot then jumps to its link address.
4995 To be able to implement the initialization code in C, a (small!)
4996 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4997 which provide such a feature like MPC8xx or MPC8260), or in a locked
4998 part of the data cache. After that, U-Boot initializes the CPU core,
4999 the caches and the SIU.
5001 Next, all (potentially) available memory banks are mapped using a
5002 preliminary mapping. For example, we put them on 512 MB boundaries
5003 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5004 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5005 programmed for SDRAM access. Using the temporary configuration, a
5006 simple memory test is run that determines the size of the SDRAM
5009 When there is more than one SDRAM bank, and the banks are of
5010 different size, the largest is mapped first. For equal size, the first
5011 bank (CS2#) is mapped first. The first mapping is always for address
5012 0x00000000, with any additional banks following immediately to create
5013 contiguous memory starting from 0.
5015 Then, the monitor installs itself at the upper end of the SDRAM area
5016 and allocates memory for use by malloc() and for the global Board
5017 Info data; also, the exception vector code is copied to the low RAM
5018 pages, and the final stack is set up.
5020 Only after this relocation will you have a "normal" C environment;
5021 until that you are restricted in several ways, mostly because you are
5022 running from ROM, and because the code will have to be relocated to a
5026 U-Boot Porting Guide:
5027 ----------------------
5029 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5033 int main(int argc, char *argv[])
5035 sighandler_t no_more_time;
5037 signal(SIGALRM, no_more_time);
5038 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5040 if (available_money > available_manpower) {
5041 Pay consultant to port U-Boot;
5045 Download latest U-Boot source;
5047 Subscribe to u-boot mailing list;
5050 email("Hi, I am new to U-Boot, how do I get started?");
5053 Read the README file in the top level directory;
5054 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5055 Read applicable doc/*.README;
5056 Read the source, Luke;
5057 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5060 if (available_money > toLocalCurrency ($2500))
5063 Add a lot of aggravation and time;
5065 if (a similar board exists) { /* hopefully... */
5066 cp -a board/<similar> board/<myboard>
5067 cp include/configs/<similar>.h include/configs/<myboard>.h
5069 Create your own board support subdirectory;
5070 Create your own board include/configs/<myboard>.h file;
5072 Edit new board/<myboard> files
5073 Edit new include/configs/<myboard>.h
5078 Add / modify source code;
5082 email("Hi, I am having problems...");
5084 Send patch file to the U-Boot email list;
5085 if (reasonable critiques)
5086 Incorporate improvements from email list code review;
5088 Defend code as written;
5094 void no_more_time (int sig)
5103 All contributions to U-Boot should conform to the Linux kernel
5104 coding style; see the file "Documentation/CodingStyle" and the script
5105 "scripts/Lindent" in your Linux kernel source directory.
5107 Source files originating from a different project (for example the
5108 MTD subsystem) are generally exempt from these guidelines and are not
5109 reformated to ease subsequent migration to newer versions of those
5112 Please note that U-Boot is implemented in C (and to some small parts in
5113 Assembler); no C++ is used, so please do not use C++ style comments (//)
5116 Please also stick to the following formatting rules:
5117 - remove any trailing white space
5118 - use TAB characters for indentation and vertical alignment, not spaces
5119 - make sure NOT to use DOS '\r\n' line feeds
5120 - do not add more than 2 consecutive empty lines to source files
5121 - do not add trailing empty lines to source files
5123 Submissions which do not conform to the standards may be returned
5124 with a request to reformat the changes.
5130 Since the number of patches for U-Boot is growing, we need to
5131 establish some rules. Submissions which do not conform to these rules
5132 may be rejected, even when they contain important and valuable stuff.
5134 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5136 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5137 see http://lists.denx.de/mailman/listinfo/u-boot
5139 When you send a patch, please include the following information with
5142 * For bug fixes: a description of the bug and how your patch fixes
5143 this bug. Please try to include a way of demonstrating that the
5144 patch actually fixes something.
5146 * For new features: a description of the feature and your
5149 * A CHANGELOG entry as plaintext (separate from the patch)
5151 * For major contributions, your entry to the CREDITS file
5153 * When you add support for a new board, don't forget to add this
5154 board to the MAINTAINERS file, too.
5156 * If your patch adds new configuration options, don't forget to
5157 document these in the README file.
5159 * The patch itself. If you are using git (which is *strongly*
5160 recommended) you can easily generate the patch using the
5161 "git format-patch". If you then use "git send-email" to send it to
5162 the U-Boot mailing list, you will avoid most of the common problems
5163 with some other mail clients.
5165 If you cannot use git, use "diff -purN OLD NEW". If your version of
5166 diff does not support these options, then get the latest version of
5169 The current directory when running this command shall be the parent
5170 directory of the U-Boot source tree (i. e. please make sure that
5171 your patch includes sufficient directory information for the
5174 We prefer patches as plain text. MIME attachments are discouraged,
5175 and compressed attachments must not be used.
5177 * If one logical set of modifications affects or creates several
5178 files, all these changes shall be submitted in a SINGLE patch file.
5180 * Changesets that contain different, unrelated modifications shall be
5181 submitted as SEPARATE patches, one patch per changeset.
5186 * Before sending the patch, run the MAKEALL script on your patched
5187 source tree and make sure that no errors or warnings are reported
5188 for any of the boards.
5190 * Keep your modifications to the necessary minimum: A patch
5191 containing several unrelated changes or arbitrary reformats will be
5192 returned with a request to re-formatting / split it.
5194 * If you modify existing code, make sure that your new code does not
5195 add to the memory footprint of the code ;-) Small is beautiful!
5196 When adding new features, these should compile conditionally only
5197 (using #ifdef), and the resulting code with the new feature
5198 disabled must not need more memory than the old code without your
5201 * Remember that there is a size limit of 100 kB per message on the
5202 u-boot mailing list. Bigger patches will be moderated. If they are
5203 reasonable and not too big, they will be acknowledged. But patches
5204 bigger than the size limit should be avoided.