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_ANSI is defined, console will support
665 a limited number of ANSI escape sequences (cursor control,
666 erase functions and limited graphics rendition control).
668 When CONFIG_CFB_CONSOLE is defined, video console is
669 default i/o. Serial console can be forced with
670 environment 'console=serial'.
672 When CONFIG_SILENT_CONSOLE is defined, all console
673 messages (by U-Boot and Linux!) can be silenced with
674 the "silent" environment variable. See
675 doc/README.silent for more information.
678 CONFIG_BAUDRATE - in bps
679 Select one of the baudrates listed in
680 CONFIG_SYS_BAUDRATE_TABLE, see below.
681 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
683 - Console Rx buffer length
684 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
685 the maximum receive buffer length for the SMC.
686 This option is actual only for 82xx and 8xx possible.
687 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
688 must be defined, to setup the maximum idle timeout for
691 - Pre-Console Buffer:
692 Prior to the console being initialised (i.e. serial UART
693 initialised etc) all console output is silently discarded.
694 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
695 buffer any console messages prior to the console being
696 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
697 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
698 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
699 bytes are output before the console is initialised, the
700 earlier bytes are discarded.
702 'Sane' compilers will generate smaller code if
703 CONFIG_PRE_CON_BUF_SZ is a power of 2
705 - Safe printf() functions
706 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
707 the printf() functions. These are defined in
708 include/vsprintf.h and include snprintf(), vsnprintf() and
709 so on. Code size increase is approximately 300-500 bytes.
710 If this option is not given then these functions will
711 silently discard their buffer size argument - this means
712 you are not getting any overflow checking in this case.
714 - Boot Delay: CONFIG_BOOTDELAY - in seconds
715 Delay before automatically booting the default image;
716 set to -1 to disable autoboot.
717 set to -2 to autoboot with no delay and not check for abort
718 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
720 See doc/README.autoboot for these options that
721 work with CONFIG_BOOTDELAY. None are required.
722 CONFIG_BOOT_RETRY_TIME
723 CONFIG_BOOT_RETRY_MIN
724 CONFIG_AUTOBOOT_KEYED
725 CONFIG_AUTOBOOT_PROMPT
726 CONFIG_AUTOBOOT_DELAY_STR
727 CONFIG_AUTOBOOT_STOP_STR
728 CONFIG_AUTOBOOT_DELAY_STR2
729 CONFIG_AUTOBOOT_STOP_STR2
730 CONFIG_ZERO_BOOTDELAY_CHECK
731 CONFIG_RESET_TO_RETRY
735 Only needed when CONFIG_BOOTDELAY is enabled;
736 define a command string that is automatically executed
737 when no character is read on the console interface
738 within "Boot Delay" after reset.
741 This can be used to pass arguments to the bootm
742 command. The value of CONFIG_BOOTARGS goes into the
743 environment value "bootargs".
745 CONFIG_RAMBOOT and CONFIG_NFSBOOT
746 The value of these goes into the environment as
747 "ramboot" and "nfsboot" respectively, and can be used
748 as a convenience, when switching between booting from
754 When this option is #defined, the existence of the
755 environment variable "preboot" will be checked
756 immediately before starting the CONFIG_BOOTDELAY
757 countdown and/or running the auto-boot command resp.
758 entering interactive mode.
760 This feature is especially useful when "preboot" is
761 automatically generated or modified. For an example
762 see the LWMON board specific code: here "preboot" is
763 modified when the user holds down a certain
764 combination of keys on the (special) keyboard when
767 - Serial Download Echo Mode:
769 If defined to 1, all characters received during a
770 serial download (using the "loads" command) are
771 echoed back. This might be needed by some terminal
772 emulations (like "cu"), but may as well just take
773 time on others. This setting #define's the initial
774 value of the "loads_echo" environment variable.
776 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
778 Select one of the baudrates listed in
779 CONFIG_SYS_BAUDRATE_TABLE, see below.
782 Monitor commands can be included or excluded
783 from the build by using the #include files
784 <config_cmd_all.h> and #undef'ing unwanted
785 commands, or using <config_cmd_default.h>
786 and augmenting with additional #define's
789 The default command configuration includes all commands
790 except those marked below with a "*".
792 CONFIG_CMD_ASKENV * ask for env variable
793 CONFIG_CMD_BDI bdinfo
794 CONFIG_CMD_BEDBUG * Include BedBug Debugger
795 CONFIG_CMD_BMP * BMP support
796 CONFIG_CMD_BSP * Board specific commands
797 CONFIG_CMD_BOOTD bootd
798 CONFIG_CMD_CACHE * icache, dcache
799 CONFIG_CMD_CONSOLE coninfo
800 CONFIG_CMD_CRC32 * crc32
801 CONFIG_CMD_DATE * support for RTC, date/time...
802 CONFIG_CMD_DHCP * DHCP support
803 CONFIG_CMD_DIAG * Diagnostics
804 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
805 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
806 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
807 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
808 CONFIG_CMD_DTT * Digital Therm and Thermostat
809 CONFIG_CMD_ECHO echo arguments
810 CONFIG_CMD_EDITENV edit env variable
811 CONFIG_CMD_EEPROM * EEPROM read/write support
812 CONFIG_CMD_ELF * bootelf, bootvx
813 CONFIG_CMD_EXPORTENV * export the environment
814 CONFIG_CMD_EXT2 * ext2 command support
815 CONFIG_CMD_EXT4 * ext4 command support
816 CONFIG_CMD_SAVEENV saveenv
817 CONFIG_CMD_FDC * Floppy Disk Support
818 CONFIG_CMD_FAT * FAT command support
819 CONFIG_CMD_FDOS * Dos diskette Support
820 CONFIG_CMD_FLASH flinfo, erase, protect
821 CONFIG_CMD_FPGA FPGA device initialization support
822 CONFIG_CMD_GO * the 'go' command (exec code)
823 CONFIG_CMD_GREPENV * search environment
824 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
825 CONFIG_CMD_I2C * I2C serial bus support
826 CONFIG_CMD_IDE * IDE harddisk support
827 CONFIG_CMD_IMI iminfo
828 CONFIG_CMD_IMLS List all found images
829 CONFIG_CMD_IMMAP * IMMR dump support
830 CONFIG_CMD_IMPORTENV * import an environment
831 CONFIG_CMD_INI * import data from an ini file into the env
832 CONFIG_CMD_IRQ * irqinfo
833 CONFIG_CMD_ITEST Integer/string test of 2 values
834 CONFIG_CMD_JFFS2 * JFFS2 Support
835 CONFIG_CMD_KGDB * kgdb
836 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
837 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
839 CONFIG_CMD_LOADB loadb
840 CONFIG_CMD_LOADS loads
841 CONFIG_CMD_MD5SUM print md5 message digest
842 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
843 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
845 CONFIG_CMD_MISC Misc functions like sleep etc
846 CONFIG_CMD_MMC * MMC memory mapped support
847 CONFIG_CMD_MII * MII utility commands
848 CONFIG_CMD_MTDPARTS * MTD partition support
849 CONFIG_CMD_NAND * NAND support
850 CONFIG_CMD_NET bootp, tftpboot, rarpboot
851 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
852 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
853 CONFIG_CMD_PCI * pciinfo
854 CONFIG_CMD_PCMCIA * PCMCIA support
855 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
857 CONFIG_CMD_PORTIO * Port I/O
858 CONFIG_CMD_REGINFO * Register dump
859 CONFIG_CMD_RUN run command in env variable
860 CONFIG_CMD_SAVES * save S record dump
861 CONFIG_CMD_SCSI * SCSI Support
862 CONFIG_CMD_SDRAM * print SDRAM configuration information
863 (requires CONFIG_CMD_I2C)
864 CONFIG_CMD_SETGETDCR Support for DCR Register access
866 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
867 CONFIG_CMD_SHA1SUM print sha1 memory digest
868 (requires CONFIG_CMD_MEMORY)
869 CONFIG_CMD_SOURCE "source" command Support
870 CONFIG_CMD_SPI * SPI serial bus support
871 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
872 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
873 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
874 CONFIG_CMD_TIMER * access to the system tick timer
875 CONFIG_CMD_USB * USB support
876 CONFIG_CMD_CDP * Cisco Discover Protocol support
877 CONFIG_CMD_MFSL * Microblaze FSL support
880 EXAMPLE: If you want all functions except of network
881 support you can write:
883 #include "config_cmd_all.h"
884 #undef CONFIG_CMD_NET
887 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
889 Note: Don't enable the "icache" and "dcache" commands
890 (configuration option CONFIG_CMD_CACHE) unless you know
891 what you (and your U-Boot users) are doing. Data
892 cache cannot be enabled on systems like the 8xx or
893 8260 (where accesses to the IMMR region must be
894 uncached), and it cannot be disabled on all other
895 systems where we (mis-) use the data cache to hold an
896 initial stack and some data.
899 XXX - this list needs to get updated!
903 If this variable is defined, U-Boot will use a device tree
904 to configure its devices, instead of relying on statically
905 compiled #defines in the board file. This option is
906 experimental and only available on a few boards. The device
907 tree is available in the global data as gd->fdt_blob.
909 U-Boot needs to get its device tree from somewhere. This can
910 be done using one of the two options below:
913 If this variable is defined, U-Boot will embed a device tree
914 binary in its image. This device tree file should be in the
915 board directory and called <soc>-<board>.dts. The binary file
916 is then picked up in board_init_f() and made available through
917 the global data structure as gd->blob.
920 If this variable is defined, U-Boot will build a device tree
921 binary. It will be called u-boot.dtb. Architecture-specific
922 code will locate it at run-time. Generally this works by:
924 cat u-boot.bin u-boot.dtb >image.bin
926 and in fact, U-Boot does this for you, creating a file called
927 u-boot-dtb.bin which is useful in the common case. You can
928 still use the individual files if you need something more
933 If this variable is defined, it enables watchdog
934 support for the SoC. There must be support in the SoC
935 specific code for a watchdog. For the 8xx and 8260
936 CPUs, the SIU Watchdog feature is enabled in the SYPCR
937 register. When supported for a specific SoC is
938 available, then no further board specific code should
942 When using a watchdog circuitry external to the used
943 SoC, then define this variable and provide board
944 specific code for the "hw_watchdog_reset" function.
947 CONFIG_VERSION_VARIABLE
948 If this variable is defined, an environment variable
949 named "ver" is created by U-Boot showing the U-Boot
950 version as printed by the "version" command.
951 Any change to this variable will be reverted at the
956 When CONFIG_CMD_DATE is selected, the type of the RTC
957 has to be selected, too. Define exactly one of the
960 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
961 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
962 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
963 CONFIG_RTC_MC146818 - use MC146818 RTC
964 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
965 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
966 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
967 CONFIG_RTC_DS164x - use Dallas DS164x RTC
968 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
969 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
970 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
971 CONFIG_SYS_RV3029_TCR - enable trickle charger on
974 Note that if the RTC uses I2C, then the I2C interface
975 must also be configured. See I2C Support, below.
978 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
979 CONFIG_PCA953X_INFO - enable pca953x info command
981 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
982 chip-ngpio pairs that tell the PCA953X driver the number of
983 pins supported by a particular chip.
985 Note that if the GPIO device uses I2C, then the I2C interface
986 must also be configured. See I2C Support, below.
990 When CONFIG_TIMESTAMP is selected, the timestamp
991 (date and time) of an image is printed by image
992 commands like bootm or iminfo. This option is
993 automatically enabled when you select CONFIG_CMD_DATE .
995 - Partition Labels (disklabels) Supported:
996 Zero or more of the following:
997 CONFIG_MAC_PARTITION Apple's MacOS partition table.
998 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
999 Intel architecture, USB sticks, etc.
1000 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1001 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1002 bootloader. Note 2TB partition limit; see
1004 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1006 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1007 CONFIG_CMD_SCSI) you must configure support for at
1008 least one non-MTD partition type as well.
1011 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1012 board configurations files but used nowhere!
1014 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1015 be performed by calling the function
1016 ide_set_reset(int reset)
1017 which has to be defined in a board specific file
1022 Set this to enable ATAPI support.
1027 Set this to enable support for disks larger than 137GB
1028 Also look at CONFIG_SYS_64BIT_LBA.
1029 Whithout these , LBA48 support uses 32bit variables and will 'only'
1030 support disks up to 2.1TB.
1032 CONFIG_SYS_64BIT_LBA:
1033 When enabled, makes the IDE subsystem use 64bit sector addresses.
1037 At the moment only there is only support for the
1038 SYM53C8XX SCSI controller; define
1039 CONFIG_SCSI_SYM53C8XX to enable it.
1041 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1042 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1043 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1044 maximum numbers of LUNs, SCSI ID's and target
1046 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1048 The environment variable 'scsidevs' is set to the number of
1049 SCSI devices found during the last scan.
1051 - NETWORK Support (PCI):
1053 Support for Intel 8254x/8257x gigabit chips.
1056 Utility code for direct access to the SPI bus on Intel 8257x.
1057 This does not do anything useful unless you set at least one
1058 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1060 CONFIG_E1000_SPI_GENERIC
1061 Allow generic access to the SPI bus on the Intel 8257x, for
1062 example with the "sspi" command.
1065 Management command for E1000 devices. When used on devices
1066 with SPI support you can reprogram the EEPROM from U-Boot.
1068 CONFIG_E1000_FALLBACK_MAC
1069 default MAC for empty EEPROM after production.
1072 Support for Intel 82557/82559/82559ER chips.
1073 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1074 write routine for first time initialisation.
1077 Support for Digital 2114x chips.
1078 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1079 modem chip initialisation (KS8761/QS6611).
1082 Support for National dp83815 chips.
1085 Support for National dp8382[01] gigabit chips.
1087 - NETWORK Support (other):
1089 CONFIG_DRIVER_AT91EMAC
1090 Support for AT91RM9200 EMAC.
1093 Define this to use reduced MII inteface
1095 CONFIG_DRIVER_AT91EMAC_QUIET
1096 If this defined, the driver is quiet.
1097 The driver doen't show link status messages.
1099 CONFIG_CALXEDA_XGMAC
1100 Support for the Calxeda XGMAC device
1103 Support for SMSC's LAN91C96 chips.
1105 CONFIG_LAN91C96_BASE
1106 Define this to hold the physical address
1107 of the LAN91C96's I/O space
1109 CONFIG_LAN91C96_USE_32_BIT
1110 Define this to enable 32 bit addressing
1113 Support for SMSC's LAN91C111 chip
1115 CONFIG_SMC91111_BASE
1116 Define this to hold the physical address
1117 of the device (I/O space)
1119 CONFIG_SMC_USE_32_BIT
1120 Define this if data bus is 32 bits
1122 CONFIG_SMC_USE_IOFUNCS
1123 Define this to use i/o functions instead of macros
1124 (some hardware wont work with macros)
1126 CONFIG_DRIVER_TI_EMAC
1127 Support for davinci emac
1129 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1130 Define this if you have more then 3 PHYs.
1133 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1135 CONFIG_FTGMAC100_EGIGA
1136 Define this to use GE link update with gigabit PHY.
1137 Define this if FTGMAC100 is connected to gigabit PHY.
1138 If your system has 10/100 PHY only, it might not occur
1139 wrong behavior. Because PHY usually return timeout or
1140 useless data when polling gigabit status and gigabit
1141 control registers. This behavior won't affect the
1142 correctnessof 10/100 link speed update.
1145 Support for SMSC's LAN911x and LAN921x chips
1148 Define this to hold the physical address
1149 of the device (I/O space)
1151 CONFIG_SMC911X_32_BIT
1152 Define this if data bus is 32 bits
1154 CONFIG_SMC911X_16_BIT
1155 Define this if data bus is 16 bits. If your processor
1156 automatically converts one 32 bit word to two 16 bit
1157 words you may also try CONFIG_SMC911X_32_BIT.
1160 Support for Renesas on-chip Ethernet controller
1162 CONFIG_SH_ETHER_USE_PORT
1163 Define the number of ports to be used
1165 CONFIG_SH_ETHER_PHY_ADDR
1166 Define the ETH PHY's address
1168 CONFIG_SH_ETHER_CACHE_WRITEBACK
1169 If this option is set, the driver enables cache flush.
1172 CONFIG_GENERIC_LPC_TPM
1173 Support for generic parallel port TPM devices. Only one device
1174 per system is supported at this time.
1176 CONFIG_TPM_TIS_BASE_ADDRESS
1177 Base address where the generic TPM device is mapped
1178 to. Contemporary x86 systems usually map it at
1182 At the moment only the UHCI host controller is
1183 supported (PIP405, MIP405, MPC5200); define
1184 CONFIG_USB_UHCI to enable it.
1185 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1186 and define CONFIG_USB_STORAGE to enable the USB
1189 Supported are USB Keyboards and USB Floppy drives
1191 MPC5200 USB requires additional defines:
1193 for 528 MHz Clock: 0x0001bbbb
1197 for differential drivers: 0x00001000
1198 for single ended drivers: 0x00005000
1199 for differential drivers on PSC3: 0x00000100
1200 for single ended drivers on PSC3: 0x00004100
1201 CONFIG_SYS_USB_EVENT_POLL
1202 May be defined to allow interrupt polling
1203 instead of using asynchronous interrupts
1205 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1206 txfilltuning field in the EHCI controller on reset.
1209 Define the below if you wish to use the USB console.
1210 Once firmware is rebuilt from a serial console issue the
1211 command "setenv stdin usbtty; setenv stdout usbtty" and
1212 attach your USB cable. The Unix command "dmesg" should print
1213 it has found a new device. The environment variable usbtty
1214 can be set to gserial or cdc_acm to enable your device to
1215 appear to a USB host as a Linux gserial device or a
1216 Common Device Class Abstract Control Model serial device.
1217 If you select usbtty = gserial you should be able to enumerate
1219 # modprobe usbserial vendor=0xVendorID product=0xProductID
1220 else if using cdc_acm, simply setting the environment
1221 variable usbtty to be cdc_acm should suffice. The following
1222 might be defined in YourBoardName.h
1225 Define this to build a UDC device
1228 Define this to have a tty type of device available to
1229 talk to the UDC device
1232 Define this to enable the high speed support for usb
1233 device and usbtty. If this feature is enabled, a routine
1234 int is_usbd_high_speed(void)
1235 also needs to be defined by the driver to dynamically poll
1236 whether the enumeration has succeded at high speed or full
1239 CONFIG_SYS_CONSOLE_IS_IN_ENV
1240 Define this if you want stdin, stdout &/or stderr to
1244 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1245 Derive USB clock from external clock "blah"
1246 - CONFIG_SYS_USB_EXTC_CLK 0x02
1248 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1249 Derive USB clock from brgclk
1250 - CONFIG_SYS_USB_BRG_CLK 0x04
1252 If you have a USB-IF assigned VendorID then you may wish to
1253 define your own vendor specific values either in BoardName.h
1254 or directly in usbd_vendor_info.h. If you don't define
1255 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1256 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1257 should pretend to be a Linux device to it's target host.
1259 CONFIG_USBD_MANUFACTURER
1260 Define this string as the name of your company for
1261 - CONFIG_USBD_MANUFACTURER "my company"
1263 CONFIG_USBD_PRODUCT_NAME
1264 Define this string as the name of your product
1265 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1267 CONFIG_USBD_VENDORID
1268 Define this as your assigned Vendor ID from the USB
1269 Implementors Forum. This *must* be a genuine Vendor ID
1270 to avoid polluting the USB namespace.
1271 - CONFIG_USBD_VENDORID 0xFFFF
1273 CONFIG_USBD_PRODUCTID
1274 Define this as the unique Product ID
1276 - CONFIG_USBD_PRODUCTID 0xFFFF
1278 - ULPI Layer Support:
1279 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1280 the generic ULPI layer. The generic layer accesses the ULPI PHY
1281 via the platform viewport, so you need both the genric layer and
1282 the viewport enabled. Currently only Chipidea/ARC based
1283 viewport is supported.
1284 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1285 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1286 If your ULPI phy needs a different reference clock than the
1287 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1288 the appropriate value in Hz.
1291 The MMC controller on the Intel PXA is supported. To
1292 enable this define CONFIG_MMC. The MMC can be
1293 accessed from the boot prompt by mapping the device
1294 to physical memory similar to flash. Command line is
1295 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1296 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1299 Support for Renesas on-chip MMCIF controller
1301 CONFIG_SH_MMCIF_ADDR
1302 Define the base address of MMCIF registers
1305 Define the clock frequency for MMCIF
1307 - Journaling Flash filesystem support:
1308 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1309 CONFIG_JFFS2_NAND_DEV
1310 Define these for a default partition on a NAND device
1312 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1313 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1314 Define these for a default partition on a NOR device
1316 CONFIG_SYS_JFFS_CUSTOM_PART
1317 Define this to create an own partition. You have to provide a
1318 function struct part_info* jffs2_part_info(int part_num)
1320 If you define only one JFFS2 partition you may also want to
1321 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1322 to disable the command chpart. This is the default when you
1323 have not defined a custom partition
1325 - FAT(File Allocation Table) filesystem write function support:
1328 Define this to enable support for saving memory data as a
1329 file in FAT formatted partition.
1331 This will also enable the command "fatwrite" enabling the
1332 user to write files to FAT.
1334 CBFS (Coreboot Filesystem) support
1337 Define this to enable support for reading from a Coreboot
1338 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1344 Define this to enable standard (PC-Style) keyboard
1348 Standard PC keyboard driver with US (is default) and
1349 GERMAN key layout (switch via environment 'keymap=de') support.
1350 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1351 for cfb_console. Supports cursor blinking.
1356 Define this to enable video support (for output to
1359 CONFIG_VIDEO_CT69000
1361 Enable Chips & Technologies 69000 Video chip
1363 CONFIG_VIDEO_SMI_LYNXEM
1364 Enable Silicon Motion SMI 712/710/810 Video chip. The
1365 video output is selected via environment 'videoout'
1366 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1369 For the CT69000 and SMI_LYNXEM drivers, videomode is
1370 selected via environment 'videomode'. Two different ways
1372 - "videomode=num" 'num' is a standard LiLo mode numbers.
1373 Following standard modes are supported (* is default):
1375 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1376 -------------+---------------------------------------------
1377 8 bits | 0x301* 0x303 0x305 0x161 0x307
1378 15 bits | 0x310 0x313 0x316 0x162 0x319
1379 16 bits | 0x311 0x314 0x317 0x163 0x31A
1380 24 bits | 0x312 0x315 0x318 ? 0x31B
1381 -------------+---------------------------------------------
1382 (i.e. setenv videomode 317; saveenv; reset;)
1384 - "videomode=bootargs" all the video parameters are parsed
1385 from the bootargs. (See drivers/video/videomodes.c)
1388 CONFIG_VIDEO_SED13806
1389 Enable Epson SED13806 driver. This driver supports 8bpp
1390 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1391 or CONFIG_VIDEO_SED13806_16BPP
1394 Enable the Freescale DIU video driver. Reference boards for
1395 SOCs that have a DIU should define this macro to enable DIU
1396 support, and should also define these other macros:
1402 CONFIG_VIDEO_SW_CURSOR
1403 CONFIG_VGA_AS_SINGLE_DEVICE
1405 CONFIG_VIDEO_BMP_LOGO
1407 The DIU driver will look for the 'video-mode' environment
1408 variable, and if defined, enable the DIU as a console during
1409 boot. See the documentation file README.video for a
1410 description of this variable.
1415 Define this to enable a custom keyboard support.
1416 This simply calls drv_keyboard_init() which must be
1417 defined in your board-specific files.
1418 The only board using this so far is RBC823.
1420 - LCD Support: CONFIG_LCD
1422 Define this to enable LCD support (for output to LCD
1423 display); also select one of the supported displays
1424 by defining one of these:
1428 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1430 CONFIG_NEC_NL6448AC33:
1432 NEC NL6448AC33-18. Active, color, single scan.
1434 CONFIG_NEC_NL6448BC20
1436 NEC NL6448BC20-08. 6.5", 640x480.
1437 Active, color, single scan.
1439 CONFIG_NEC_NL6448BC33_54
1441 NEC NL6448BC33-54. 10.4", 640x480.
1442 Active, color, single scan.
1446 Sharp 320x240. Active, color, single scan.
1447 It isn't 16x9, and I am not sure what it is.
1449 CONFIG_SHARP_LQ64D341
1451 Sharp LQ64D341 display, 640x480.
1452 Active, color, single scan.
1456 HLD1045 display, 640x480.
1457 Active, color, single scan.
1461 Optrex CBL50840-2 NF-FW 99 22 M5
1463 Hitachi LMG6912RPFC-00T
1467 320x240. Black & white.
1469 Normally display is black on white background; define
1470 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1474 Support drawing of RLE8-compressed bitmaps on the LCD.
1477 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1479 If this option is set, the environment is checked for
1480 a variable "splashimage". If found, the usual display
1481 of logo, copyright and system information on the LCD
1482 is suppressed and the BMP image at the address
1483 specified in "splashimage" is loaded instead. The
1484 console is redirected to the "nulldev", too. This
1485 allows for a "silent" boot where a splash screen is
1486 loaded very quickly after power-on.
1488 CONFIG_SPLASH_SCREEN_ALIGN
1490 If this option is set the splash image can be freely positioned
1491 on the screen. Environment variable "splashpos" specifies the
1492 position as "x,y". If a positive number is given it is used as
1493 number of pixel from left/top. If a negative number is given it
1494 is used as number of pixel from right/bottom. You can also
1495 specify 'm' for centering the image.
1498 setenv splashpos m,m
1499 => image at center of screen
1501 setenv splashpos 30,20
1502 => image at x = 30 and y = 20
1504 setenv splashpos -10,m
1505 => vertically centered image
1506 at x = dspWidth - bmpWidth - 9
1508 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1510 If this option is set, additionally to standard BMP
1511 images, gzipped BMP images can be displayed via the
1512 splashscreen support or the bmp command.
1514 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1516 If this option is set, 8-bit RLE compressed BMP images
1517 can be displayed via the splashscreen support or the
1520 - Do compresssing for memory range:
1523 If this option is set, it would use zlib deflate method
1524 to compress the specified memory at its best effort.
1526 - Compression support:
1529 If this option is set, support for bzip2 compressed
1530 images is included. If not, only uncompressed and gzip
1531 compressed images are supported.
1533 NOTE: the bzip2 algorithm requires a lot of RAM, so
1534 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1539 If this option is set, support for lzma compressed
1542 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1543 requires an amount of dynamic memory that is given by the
1546 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1548 Where lc and lp stand for, respectively, Literal context bits
1549 and Literal pos bits.
1551 This value is upper-bounded by 14MB in the worst case. Anyway,
1552 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1553 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1554 a very small buffer.
1556 Use the lzmainfo tool to determinate the lc and lp values and
1557 then calculate the amount of needed dynamic memory (ensuring
1558 the appropriate CONFIG_SYS_MALLOC_LEN value).
1563 The address of PHY on MII bus.
1565 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1567 The clock frequency of the MII bus
1571 If this option is set, support for speed/duplex
1572 detection of gigabit PHY is included.
1574 CONFIG_PHY_RESET_DELAY
1576 Some PHY like Intel LXT971A need extra delay after
1577 reset before any MII register access is possible.
1578 For such PHY, set this option to the usec delay
1579 required. (minimum 300usec for LXT971A)
1581 CONFIG_PHY_CMD_DELAY (ppc4xx)
1583 Some PHY like Intel LXT971A need extra delay after
1584 command issued before MII status register can be read
1594 Define a default value for Ethernet address to use
1595 for the respective Ethernet interface, in case this
1596 is not determined automatically.
1601 Define a default value for the IP address to use for
1602 the default Ethernet interface, in case this is not
1603 determined through e.g. bootp.
1604 (Environment variable "ipaddr")
1606 - Server IP address:
1609 Defines a default value for the IP address of a TFTP
1610 server to contact when using the "tftboot" command.
1611 (Environment variable "serverip")
1613 CONFIG_KEEP_SERVERADDR
1615 Keeps the server's MAC address, in the env 'serveraddr'
1616 for passing to bootargs (like Linux's netconsole option)
1618 - Gateway IP address:
1621 Defines a default value for the IP address of the
1622 default router where packets to other networks are
1624 (Environment variable "gatewayip")
1629 Defines a default value for the subnet mask (or
1630 routing prefix) which is used to determine if an IP
1631 address belongs to the local subnet or needs to be
1632 forwarded through a router.
1633 (Environment variable "netmask")
1635 - Multicast TFTP Mode:
1638 Defines whether you want to support multicast TFTP as per
1639 rfc-2090; for example to work with atftp. Lets lots of targets
1640 tftp down the same boot image concurrently. Note: the Ethernet
1641 driver in use must provide a function: mcast() to join/leave a
1644 - BOOTP Recovery Mode:
1645 CONFIG_BOOTP_RANDOM_DELAY
1647 If you have many targets in a network that try to
1648 boot using BOOTP, you may want to avoid that all
1649 systems send out BOOTP requests at precisely the same
1650 moment (which would happen for instance at recovery
1651 from a power failure, when all systems will try to
1652 boot, thus flooding the BOOTP server. Defining
1653 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1654 inserted before sending out BOOTP requests. The
1655 following delays are inserted then:
1657 1st BOOTP request: delay 0 ... 1 sec
1658 2nd BOOTP request: delay 0 ... 2 sec
1659 3rd BOOTP request: delay 0 ... 4 sec
1661 BOOTP requests: delay 0 ... 8 sec
1663 - DHCP Advanced Options:
1664 You can fine tune the DHCP functionality by defining
1665 CONFIG_BOOTP_* symbols:
1667 CONFIG_BOOTP_SUBNETMASK
1668 CONFIG_BOOTP_GATEWAY
1669 CONFIG_BOOTP_HOSTNAME
1670 CONFIG_BOOTP_NISDOMAIN
1671 CONFIG_BOOTP_BOOTPATH
1672 CONFIG_BOOTP_BOOTFILESIZE
1675 CONFIG_BOOTP_SEND_HOSTNAME
1676 CONFIG_BOOTP_NTPSERVER
1677 CONFIG_BOOTP_TIMEOFFSET
1678 CONFIG_BOOTP_VENDOREX
1679 CONFIG_BOOTP_MAY_FAIL
1681 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1682 environment variable, not the BOOTP server.
1684 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1685 after the configured retry count, the call will fail
1686 instead of starting over. This can be used to fail over
1687 to Link-local IP address configuration if the DHCP server
1690 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1691 serverip from a DHCP server, it is possible that more
1692 than one DNS serverip is offered to the client.
1693 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1694 serverip will be stored in the additional environment
1695 variable "dnsip2". The first DNS serverip is always
1696 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1699 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1700 to do a dynamic update of a DNS server. To do this, they
1701 need the hostname of the DHCP requester.
1702 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1703 of the "hostname" environment variable is passed as
1704 option 12 to the DHCP server.
1706 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1708 A 32bit value in microseconds for a delay between
1709 receiving a "DHCP Offer" and sending the "DHCP Request".
1710 This fixes a problem with certain DHCP servers that don't
1711 respond 100% of the time to a "DHCP request". E.g. On an
1712 AT91RM9200 processor running at 180MHz, this delay needed
1713 to be *at least* 15,000 usec before a Windows Server 2003
1714 DHCP server would reply 100% of the time. I recommend at
1715 least 50,000 usec to be safe. The alternative is to hope
1716 that one of the retries will be successful but note that
1717 the DHCP timeout and retry process takes a longer than
1720 - Link-local IP address negotiation:
1721 Negotiate with other link-local clients on the local network
1722 for an address that doesn't require explicit configuration.
1723 This is especially useful if a DHCP server cannot be guaranteed
1724 to exist in all environments that the device must operate.
1726 See doc/README.link-local for more information.
1729 CONFIG_CDP_DEVICE_ID
1731 The device id used in CDP trigger frames.
1733 CONFIG_CDP_DEVICE_ID_PREFIX
1735 A two character string which is prefixed to the MAC address
1740 A printf format string which contains the ascii name of
1741 the port. Normally is set to "eth%d" which sets
1742 eth0 for the first Ethernet, eth1 for the second etc.
1744 CONFIG_CDP_CAPABILITIES
1746 A 32bit integer which indicates the device capabilities;
1747 0x00000010 for a normal host which does not forwards.
1751 An ascii string containing the version of the software.
1755 An ascii string containing the name of the platform.
1759 A 32bit integer sent on the trigger.
1761 CONFIG_CDP_POWER_CONSUMPTION
1763 A 16bit integer containing the power consumption of the
1764 device in .1 of milliwatts.
1766 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1768 A byte containing the id of the VLAN.
1770 - Status LED: CONFIG_STATUS_LED
1772 Several configurations allow to display the current
1773 status using a LED. For instance, the LED will blink
1774 fast while running U-Boot code, stop blinking as
1775 soon as a reply to a BOOTP request was received, and
1776 start blinking slow once the Linux kernel is running
1777 (supported by a status LED driver in the Linux
1778 kernel). Defining CONFIG_STATUS_LED enables this
1781 - CAN Support: CONFIG_CAN_DRIVER
1783 Defining CONFIG_CAN_DRIVER enables CAN driver support
1784 on those systems that support this (optional)
1785 feature, like the TQM8xxL modules.
1787 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1789 These enable I2C serial bus commands. Defining either of
1790 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1791 include the appropriate I2C driver for the selected CPU.
1793 This will allow you to use i2c commands at the u-boot
1794 command line (as long as you set CONFIG_CMD_I2C in
1795 CONFIG_COMMANDS) and communicate with i2c based realtime
1796 clock chips. See common/cmd_i2c.c for a description of the
1797 command line interface.
1799 CONFIG_HARD_I2C selects a hardware I2C controller.
1801 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1802 bit-banging) driver instead of CPM or similar hardware
1805 There are several other quantities that must also be
1806 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1808 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1809 to be the frequency (in Hz) at which you wish your i2c bus
1810 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1811 the CPU's i2c node address).
1813 Now, the u-boot i2c code for the mpc8xx
1814 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1815 and so its address should therefore be cleared to 0 (See,
1816 eg, MPC823e User's Manual p.16-473). So, set
1817 CONFIG_SYS_I2C_SLAVE to 0.
1819 CONFIG_SYS_I2C_INIT_MPC5XXX
1821 When a board is reset during an i2c bus transfer
1822 chips might think that the current transfer is still
1823 in progress. Reset the slave devices by sending start
1824 commands until the slave device responds.
1826 That's all that's required for CONFIG_HARD_I2C.
1828 If you use the software i2c interface (CONFIG_SOFT_I2C)
1829 then the following macros need to be defined (examples are
1830 from include/configs/lwmon.h):
1834 (Optional). Any commands necessary to enable the I2C
1835 controller or configure ports.
1837 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1841 (Only for MPC8260 CPU). The I/O port to use (the code
1842 assumes both bits are on the same port). Valid values
1843 are 0..3 for ports A..D.
1847 The code necessary to make the I2C data line active
1848 (driven). If the data line is open collector, this
1851 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1855 The code necessary to make the I2C data line tri-stated
1856 (inactive). If the data line is open collector, this
1859 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1863 Code that returns TRUE if the I2C data line is high,
1866 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1870 If <bit> is TRUE, sets the I2C data line high. If it
1871 is FALSE, it clears it (low).
1873 eg: #define I2C_SDA(bit) \
1874 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1875 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1879 If <bit> is TRUE, sets the I2C clock line high. If it
1880 is FALSE, it clears it (low).
1882 eg: #define I2C_SCL(bit) \
1883 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1884 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1888 This delay is invoked four times per clock cycle so this
1889 controls the rate of data transfer. The data rate thus
1890 is 1 / (I2C_DELAY * 4). Often defined to be something
1893 #define I2C_DELAY udelay(2)
1895 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1897 If your arch supports the generic GPIO framework (asm/gpio.h),
1898 then you may alternatively define the two GPIOs that are to be
1899 used as SCL / SDA. Any of the previous I2C_xxx macros will
1900 have GPIO-based defaults assigned to them as appropriate.
1902 You should define these to the GPIO value as given directly to
1903 the generic GPIO functions.
1905 CONFIG_SYS_I2C_INIT_BOARD
1907 When a board is reset during an i2c bus transfer
1908 chips might think that the current transfer is still
1909 in progress. On some boards it is possible to access
1910 the i2c SCLK line directly, either by using the
1911 processor pin as a GPIO or by having a second pin
1912 connected to the bus. If this option is defined a
1913 custom i2c_init_board() routine in boards/xxx/board.c
1914 is run early in the boot sequence.
1916 CONFIG_SYS_I2C_BOARD_LATE_INIT
1918 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1919 defined a custom i2c_board_late_init() routine in
1920 boards/xxx/board.c is run AFTER the operations in i2c_init()
1921 is completed. This callpoint can be used to unreset i2c bus
1922 using CPU i2c controller register accesses for CPUs whose i2c
1923 controller provide such a method. It is called at the end of
1924 i2c_init() to allow i2c_init operations to setup the i2c bus
1925 controller on the CPU (e.g. setting bus speed & slave address).
1927 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1929 This option enables configuration of bi_iic_fast[] flags
1930 in u-boot bd_info structure based on u-boot environment
1931 variable "i2cfast". (see also i2cfast)
1933 CONFIG_I2C_MULTI_BUS
1935 This option allows the use of multiple I2C buses, each of which
1936 must have a controller. At any point in time, only one bus is
1937 active. To switch to a different bus, use the 'i2c dev' command.
1938 Note that bus numbering is zero-based.
1940 CONFIG_SYS_I2C_NOPROBES
1942 This option specifies a list of I2C devices that will be skipped
1943 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1944 is set, specify a list of bus-device pairs. Otherwise, specify
1945 a 1D array of device addresses
1948 #undef CONFIG_I2C_MULTI_BUS
1949 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1951 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1953 #define CONFIG_I2C_MULTI_BUS
1954 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1956 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1958 CONFIG_SYS_SPD_BUS_NUM
1960 If defined, then this indicates the I2C bus number for DDR SPD.
1961 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1963 CONFIG_SYS_RTC_BUS_NUM
1965 If defined, then this indicates the I2C bus number for the RTC.
1966 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1968 CONFIG_SYS_DTT_BUS_NUM
1970 If defined, then this indicates the I2C bus number for the DTT.
1971 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1973 CONFIG_SYS_I2C_DTT_ADDR:
1975 If defined, specifies the I2C address of the DTT device.
1976 If not defined, then U-Boot uses predefined value for
1977 specified DTT device.
1981 Define this option if you want to use Freescale's I2C driver in
1982 drivers/i2c/fsl_i2c.c.
1986 Define this option if you have I2C devices reached over 1 .. n
1987 I2C Muxes like the pca9544a. This option addes a new I2C
1988 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1989 new I2C Bus to the existing I2C Busses. If you select the
1990 new Bus with "i2c dev", u-bbot sends first the commandos for
1991 the muxes to activate this new "bus".
1993 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1997 Adding a new I2C Bus reached over 2 pca9544a muxes
1998 The First mux with address 70 and channel 6
1999 The Second mux with address 71 and channel 4
2001 => i2c bus pca9544a:70:6:pca9544a:71:4
2003 Use the "i2c bus" command without parameter, to get a list
2004 of I2C Busses with muxes:
2007 Busses reached over muxes:
2009 reached over Mux(es):
2012 reached over Mux(es):
2017 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2018 u-boot first sends the command to the mux@70 to enable
2019 channel 6, and then the command to the mux@71 to enable
2022 After that, you can use the "normal" i2c commands as
2023 usual to communicate with your I2C devices behind
2026 This option is actually implemented for the bitbanging
2027 algorithm in common/soft_i2c.c and for the Hardware I2C
2028 Bus on the MPC8260. But it should be not so difficult
2029 to add this option to other architectures.
2031 CONFIG_SOFT_I2C_READ_REPEATED_START
2033 defining this will force the i2c_read() function in
2034 the soft_i2c driver to perform an I2C repeated start
2035 between writing the address pointer and reading the
2036 data. If this define is omitted the default behaviour
2037 of doing a stop-start sequence will be used. Most I2C
2038 devices can use either method, but some require one or
2041 - SPI Support: CONFIG_SPI
2043 Enables SPI driver (so far only tested with
2044 SPI EEPROM, also an instance works with Crystal A/D and
2045 D/As on the SACSng board)
2049 Enables the driver for SPI controller on SuperH. Currently
2050 only SH7757 is supported.
2054 Enables extended (16-bit) SPI EEPROM addressing.
2055 (symmetrical to CONFIG_I2C_X)
2059 Enables a software (bit-bang) SPI driver rather than
2060 using hardware support. This is a general purpose
2061 driver that only requires three general I/O port pins
2062 (two outputs, one input) to function. If this is
2063 defined, the board configuration must define several
2064 SPI configuration items (port pins to use, etc). For
2065 an example, see include/configs/sacsng.h.
2069 Enables a hardware SPI driver for general-purpose reads
2070 and writes. As with CONFIG_SOFT_SPI, the board configuration
2071 must define a list of chip-select function pointers.
2072 Currently supported on some MPC8xxx processors. For an
2073 example, see include/configs/mpc8349emds.h.
2077 Enables the driver for the SPI controllers on i.MX and MXC
2078 SoCs. Currently i.MX31/35/51 are supported.
2080 - FPGA Support: CONFIG_FPGA
2082 Enables FPGA subsystem.
2084 CONFIG_FPGA_<vendor>
2086 Enables support for specific chip vendors.
2089 CONFIG_FPGA_<family>
2091 Enables support for FPGA family.
2092 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2096 Specify the number of FPGA devices to support.
2098 CONFIG_SYS_FPGA_PROG_FEEDBACK
2100 Enable printing of hash marks during FPGA configuration.
2102 CONFIG_SYS_FPGA_CHECK_BUSY
2104 Enable checks on FPGA configuration interface busy
2105 status by the configuration function. This option
2106 will require a board or device specific function to
2111 If defined, a function that provides delays in the FPGA
2112 configuration driver.
2114 CONFIG_SYS_FPGA_CHECK_CTRLC
2115 Allow Control-C to interrupt FPGA configuration
2117 CONFIG_SYS_FPGA_CHECK_ERROR
2119 Check for configuration errors during FPGA bitfile
2120 loading. For example, abort during Virtex II
2121 configuration if the INIT_B line goes low (which
2122 indicated a CRC error).
2124 CONFIG_SYS_FPGA_WAIT_INIT
2126 Maximum time to wait for the INIT_B line to deassert
2127 after PROB_B has been deasserted during a Virtex II
2128 FPGA configuration sequence. The default time is 500
2131 CONFIG_SYS_FPGA_WAIT_BUSY
2133 Maximum time to wait for BUSY to deassert during
2134 Virtex II FPGA configuration. The default is 5 ms.
2136 CONFIG_SYS_FPGA_WAIT_CONFIG
2138 Time to wait after FPGA configuration. The default is
2141 - Configuration Management:
2144 If defined, this string will be added to the U-Boot
2145 version information (U_BOOT_VERSION)
2147 - Vendor Parameter Protection:
2149 U-Boot considers the values of the environment
2150 variables "serial#" (Board Serial Number) and
2151 "ethaddr" (Ethernet Address) to be parameters that
2152 are set once by the board vendor / manufacturer, and
2153 protects these variables from casual modification by
2154 the user. Once set, these variables are read-only,
2155 and write or delete attempts are rejected. You can
2156 change this behaviour:
2158 If CONFIG_ENV_OVERWRITE is #defined in your config
2159 file, the write protection for vendor parameters is
2160 completely disabled. Anybody can change or delete
2163 Alternatively, if you #define _both_ CONFIG_ETHADDR
2164 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2165 Ethernet address is installed in the environment,
2166 which can be changed exactly ONCE by the user. [The
2167 serial# is unaffected by this, i. e. it remains
2173 Define this variable to enable the reservation of
2174 "protected RAM", i. e. RAM which is not overwritten
2175 by U-Boot. Define CONFIG_PRAM to hold the number of
2176 kB you want to reserve for pRAM. You can overwrite
2177 this default value by defining an environment
2178 variable "pram" to the number of kB you want to
2179 reserve. Note that the board info structure will
2180 still show the full amount of RAM. If pRAM is
2181 reserved, a new environment variable "mem" will
2182 automatically be defined to hold the amount of
2183 remaining RAM in a form that can be passed as boot
2184 argument to Linux, for instance like that:
2186 setenv bootargs ... mem=\${mem}
2189 This way you can tell Linux not to use this memory,
2190 either, which results in a memory region that will
2191 not be affected by reboots.
2193 *WARNING* If your board configuration uses automatic
2194 detection of the RAM size, you must make sure that
2195 this memory test is non-destructive. So far, the
2196 following board configurations are known to be
2199 IVMS8, IVML24, SPD8xx, TQM8xxL,
2200 HERMES, IP860, RPXlite, LWMON,
2206 Define this variable to stop the system in case of a
2207 fatal error, so that you have to reset it manually.
2208 This is probably NOT a good idea for an embedded
2209 system where you want the system to reboot
2210 automatically as fast as possible, but it may be
2211 useful during development since you can try to debug
2212 the conditions that lead to the situation.
2214 CONFIG_NET_RETRY_COUNT
2216 This variable defines the number of retries for
2217 network operations like ARP, RARP, TFTP, or BOOTP
2218 before giving up the operation. If not defined, a
2219 default value of 5 is used.
2223 Timeout waiting for an ARP reply in milliseconds.
2227 Timeout in milliseconds used in NFS protocol.
2228 If you encounter "ERROR: Cannot umount" in nfs command,
2229 try longer timeout such as
2230 #define CONFIG_NFS_TIMEOUT 10000UL
2232 - Command Interpreter:
2233 CONFIG_AUTO_COMPLETE
2235 Enable auto completion of commands using TAB.
2237 Note that this feature has NOT been implemented yet
2238 for the "hush" shell.
2241 CONFIG_SYS_HUSH_PARSER
2243 Define this variable to enable the "hush" shell (from
2244 Busybox) as command line interpreter, thus enabling
2245 powerful command line syntax like
2246 if...then...else...fi conditionals or `&&' and '||'
2247 constructs ("shell scripts").
2249 If undefined, you get the old, much simpler behaviour
2250 with a somewhat smaller memory footprint.
2253 CONFIG_SYS_PROMPT_HUSH_PS2
2255 This defines the secondary prompt string, which is
2256 printed when the command interpreter needs more input
2257 to complete a command. Usually "> ".
2261 In the current implementation, the local variables
2262 space and global environment variables space are
2263 separated. Local variables are those you define by
2264 simply typing `name=value'. To access a local
2265 variable later on, you have write `$name' or
2266 `${name}'; to execute the contents of a variable
2267 directly type `$name' at the command prompt.
2269 Global environment variables are those you use
2270 setenv/printenv to work with. To run a command stored
2271 in such a variable, you need to use the run command,
2272 and you must not use the '$' sign to access them.
2274 To store commands and special characters in a
2275 variable, please use double quotation marks
2276 surrounding the whole text of the variable, instead
2277 of the backslashes before semicolons and special
2280 - Commandline Editing and History:
2281 CONFIG_CMDLINE_EDITING
2283 Enable editing and History functions for interactive
2284 commandline input operations
2286 - Default Environment:
2287 CONFIG_EXTRA_ENV_SETTINGS
2289 Define this to contain any number of null terminated
2290 strings (variable = value pairs) that will be part of
2291 the default environment compiled into the boot image.
2293 For example, place something like this in your
2294 board's config file:
2296 #define CONFIG_EXTRA_ENV_SETTINGS \
2300 Warning: This method is based on knowledge about the
2301 internal format how the environment is stored by the
2302 U-Boot code. This is NOT an official, exported
2303 interface! Although it is unlikely that this format
2304 will change soon, there is no guarantee either.
2305 You better know what you are doing here.
2307 Note: overly (ab)use of the default environment is
2308 discouraged. Make sure to check other ways to preset
2309 the environment like the "source" command or the
2312 CONFIG_ENV_VARS_UBOOT_CONFIG
2314 Define this in order to add variables describing the
2315 U-Boot build configuration to the default environment.
2316 These will be named arch, cpu, board, vendor, and soc.
2318 Enabling this option will cause the following to be defined:
2326 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2328 Define this in order to add variables describing certain
2329 run-time determined information about the hardware to the
2330 environment. These will be named board_name, board_rev.
2332 - DataFlash Support:
2333 CONFIG_HAS_DATAFLASH
2335 Defining this option enables DataFlash features and
2336 allows to read/write in Dataflash via the standard
2339 - Serial Flash support
2342 Defining this option enables SPI flash commands
2343 'sf probe/read/write/erase/update'.
2345 Usage requires an initial 'probe' to define the serial
2346 flash parameters, followed by read/write/erase/update
2349 The following defaults may be provided by the platform
2350 to handle the common case when only a single serial
2351 flash is present on the system.
2353 CONFIG_SF_DEFAULT_BUS Bus identifier
2354 CONFIG_SF_DEFAULT_CS Chip-select
2355 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2356 CONFIG_SF_DEFAULT_SPEED in Hz
2358 - SystemACE Support:
2361 Adding this option adds support for Xilinx SystemACE
2362 chips attached via some sort of local bus. The address
2363 of the chip must also be defined in the
2364 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2366 #define CONFIG_SYSTEMACE
2367 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2369 When SystemACE support is added, the "ace" device type
2370 becomes available to the fat commands, i.e. fatls.
2372 - TFTP Fixed UDP Port:
2375 If this is defined, the environment variable tftpsrcp
2376 is used to supply the TFTP UDP source port value.
2377 If tftpsrcp isn't defined, the normal pseudo-random port
2378 number generator is used.
2380 Also, the environment variable tftpdstp is used to supply
2381 the TFTP UDP destination port value. If tftpdstp isn't
2382 defined, the normal port 69 is used.
2384 The purpose for tftpsrcp is to allow a TFTP server to
2385 blindly start the TFTP transfer using the pre-configured
2386 target IP address and UDP port. This has the effect of
2387 "punching through" the (Windows XP) firewall, allowing
2388 the remainder of the TFTP transfer to proceed normally.
2389 A better solution is to properly configure the firewall,
2390 but sometimes that is not allowed.
2392 - Show boot progress:
2393 CONFIG_SHOW_BOOT_PROGRESS
2395 Defining this option allows to add some board-
2396 specific code (calling a user-provided function
2397 "show_boot_progress(int)") that enables you to show
2398 the system's boot progress on some display (for
2399 example, some LED's) on your board. At the moment,
2400 the following checkpoints are implemented:
2402 - Detailed boot stage timing
2404 Define this option to get detailed timing of each stage
2405 of the boot process.
2407 CONFIG_BOOTSTAGE_USER_COUNT
2408 This is the number of available user bootstage records.
2409 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2410 a new ID will be allocated from this stash. If you exceed
2411 the limit, recording will stop.
2413 CONFIG_BOOTSTAGE_REPORT
2414 Define this to print a report before boot, similar to this:
2416 Timer summary in microseconds:
2419 3,575,678 3,575,678 board_init_f start
2420 3,575,695 17 arch_cpu_init A9
2421 3,575,777 82 arch_cpu_init done
2422 3,659,598 83,821 board_init_r start
2423 3,910,375 250,777 main_loop
2424 29,916,167 26,005,792 bootm_start
2425 30,361,327 445,160 start_kernel
2427 CONFIG_CMD_BOOTSTAGE
2428 Add a 'bootstage' command which supports printing a report
2429 and un/stashing of bootstage data.
2431 CONFIG_BOOTSTAGE_FDT
2432 Stash the bootstage information in the FDT. A root 'bootstage'
2433 node is created with each bootstage id as a child. Each child
2434 has a 'name' property and either 'mark' containing the
2435 mark time in microsecond, or 'accum' containing the
2436 accumulated time for that bootstage id in microseconds.
2441 name = "board_init_f";
2450 Code in the Linux kernel can find this in /proc/devicetree.
2452 Legacy uImage format:
2455 1 common/cmd_bootm.c before attempting to boot an image
2456 -1 common/cmd_bootm.c Image header has bad magic number
2457 2 common/cmd_bootm.c Image header has correct magic number
2458 -2 common/cmd_bootm.c Image header has bad checksum
2459 3 common/cmd_bootm.c Image header has correct checksum
2460 -3 common/cmd_bootm.c Image data has bad checksum
2461 4 common/cmd_bootm.c Image data has correct checksum
2462 -4 common/cmd_bootm.c Image is for unsupported architecture
2463 5 common/cmd_bootm.c Architecture check OK
2464 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2465 6 common/cmd_bootm.c Image Type check OK
2466 -6 common/cmd_bootm.c gunzip uncompression error
2467 -7 common/cmd_bootm.c Unimplemented compression type
2468 7 common/cmd_bootm.c Uncompression OK
2469 8 common/cmd_bootm.c No uncompress/copy overwrite error
2470 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2472 9 common/image.c Start initial ramdisk verification
2473 -10 common/image.c Ramdisk header has bad magic number
2474 -11 common/image.c Ramdisk header has bad checksum
2475 10 common/image.c Ramdisk header is OK
2476 -12 common/image.c Ramdisk data has bad checksum
2477 11 common/image.c Ramdisk data has correct checksum
2478 12 common/image.c Ramdisk verification complete, start loading
2479 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2480 13 common/image.c Start multifile image verification
2481 14 common/image.c No initial ramdisk, no multifile, continue.
2483 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2485 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2486 -31 post/post.c POST test failed, detected by post_output_backlog()
2487 -32 post/post.c POST test failed, detected by post_run_single()
2489 34 common/cmd_doc.c before loading a Image from a DOC device
2490 -35 common/cmd_doc.c Bad usage of "doc" command
2491 35 common/cmd_doc.c correct usage of "doc" command
2492 -36 common/cmd_doc.c No boot device
2493 36 common/cmd_doc.c correct boot device
2494 -37 common/cmd_doc.c Unknown Chip ID on boot device
2495 37 common/cmd_doc.c correct chip ID found, device available
2496 -38 common/cmd_doc.c Read Error on boot device
2497 38 common/cmd_doc.c reading Image header from DOC device OK
2498 -39 common/cmd_doc.c Image header has bad magic number
2499 39 common/cmd_doc.c Image header has correct magic number
2500 -40 common/cmd_doc.c Error reading Image from DOC device
2501 40 common/cmd_doc.c Image header has correct magic number
2502 41 common/cmd_ide.c before loading a Image from a IDE device
2503 -42 common/cmd_ide.c Bad usage of "ide" command
2504 42 common/cmd_ide.c correct usage of "ide" command
2505 -43 common/cmd_ide.c No boot device
2506 43 common/cmd_ide.c boot device found
2507 -44 common/cmd_ide.c Device not available
2508 44 common/cmd_ide.c Device available
2509 -45 common/cmd_ide.c wrong partition selected
2510 45 common/cmd_ide.c partition selected
2511 -46 common/cmd_ide.c Unknown partition table
2512 46 common/cmd_ide.c valid partition table found
2513 -47 common/cmd_ide.c Invalid partition type
2514 47 common/cmd_ide.c correct partition type
2515 -48 common/cmd_ide.c Error reading Image Header on boot device
2516 48 common/cmd_ide.c reading Image Header from IDE device OK
2517 -49 common/cmd_ide.c Image header has bad magic number
2518 49 common/cmd_ide.c Image header has correct magic number
2519 -50 common/cmd_ide.c Image header has bad checksum
2520 50 common/cmd_ide.c Image header has correct checksum
2521 -51 common/cmd_ide.c Error reading Image from IDE device
2522 51 common/cmd_ide.c reading Image from IDE device OK
2523 52 common/cmd_nand.c before loading a Image from a NAND device
2524 -53 common/cmd_nand.c Bad usage of "nand" command
2525 53 common/cmd_nand.c correct usage of "nand" command
2526 -54 common/cmd_nand.c No boot device
2527 54 common/cmd_nand.c boot device found
2528 -55 common/cmd_nand.c Unknown Chip ID on boot device
2529 55 common/cmd_nand.c correct chip ID found, device available
2530 -56 common/cmd_nand.c Error reading Image Header on boot device
2531 56 common/cmd_nand.c reading Image Header from NAND device OK
2532 -57 common/cmd_nand.c Image header has bad magic number
2533 57 common/cmd_nand.c Image header has correct magic number
2534 -58 common/cmd_nand.c Error reading Image from NAND device
2535 58 common/cmd_nand.c reading Image from NAND device OK
2537 -60 common/env_common.c Environment has a bad CRC, using default
2539 64 net/eth.c starting with Ethernet configuration.
2540 -64 net/eth.c no Ethernet found.
2541 65 net/eth.c Ethernet found.
2543 -80 common/cmd_net.c usage wrong
2544 80 common/cmd_net.c before calling NetLoop()
2545 -81 common/cmd_net.c some error in NetLoop() occurred
2546 81 common/cmd_net.c NetLoop() back without error
2547 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2548 82 common/cmd_net.c trying automatic boot
2549 83 common/cmd_net.c running "source" command
2550 -83 common/cmd_net.c some error in automatic boot or "source" command
2551 84 common/cmd_net.c end without errors
2556 100 common/cmd_bootm.c Kernel FIT Image has correct format
2557 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2558 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2559 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2560 102 common/cmd_bootm.c Kernel unit name specified
2561 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2562 103 common/cmd_bootm.c Found configuration node
2563 104 common/cmd_bootm.c Got kernel subimage node offset
2564 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2565 105 common/cmd_bootm.c Kernel subimage hash verification OK
2566 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2567 106 common/cmd_bootm.c Architecture check OK
2568 -106 common/cmd_bootm.c Kernel subimage has wrong type
2569 107 common/cmd_bootm.c Kernel subimage type OK
2570 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2571 108 common/cmd_bootm.c Got kernel subimage data/size
2572 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2573 -109 common/cmd_bootm.c Can't get kernel subimage type
2574 -110 common/cmd_bootm.c Can't get kernel subimage comp
2575 -111 common/cmd_bootm.c Can't get kernel subimage os
2576 -112 common/cmd_bootm.c Can't get kernel subimage load address
2577 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2579 120 common/image.c Start initial ramdisk verification
2580 -120 common/image.c Ramdisk FIT image has incorrect format
2581 121 common/image.c Ramdisk FIT image has correct format
2582 122 common/image.c No ramdisk subimage unit name, using configuration
2583 -122 common/image.c Can't get configuration for ramdisk subimage
2584 123 common/image.c Ramdisk unit name specified
2585 -124 common/image.c Can't get ramdisk subimage node offset
2586 125 common/image.c Got ramdisk subimage node offset
2587 -125 common/image.c Ramdisk subimage hash verification failed
2588 126 common/image.c Ramdisk subimage hash verification OK
2589 -126 common/image.c Ramdisk subimage for unsupported architecture
2590 127 common/image.c Architecture check OK
2591 -127 common/image.c Can't get ramdisk subimage data/size
2592 128 common/image.c Got ramdisk subimage data/size
2593 129 common/image.c Can't get ramdisk load address
2594 -129 common/image.c Got ramdisk load address
2596 -130 common/cmd_doc.c Incorrect FIT image format
2597 131 common/cmd_doc.c FIT image format OK
2599 -140 common/cmd_ide.c Incorrect FIT image format
2600 141 common/cmd_ide.c FIT image format OK
2602 -150 common/cmd_nand.c Incorrect FIT image format
2603 151 common/cmd_nand.c FIT image format OK
2605 - FIT image support:
2607 Enable support for the FIT uImage format.
2609 CONFIG_FIT_BEST_MATCH
2610 When no configuration is explicitly selected, default to the
2611 one whose fdt's compatibility field best matches that of
2612 U-Boot itself. A match is considered "best" if it matches the
2613 most specific compatibility entry of U-Boot's fdt's root node.
2614 The order of entries in the configuration's fdt is ignored.
2616 - Standalone program support:
2617 CONFIG_STANDALONE_LOAD_ADDR
2619 This option defines a board specific value for the
2620 address where standalone program gets loaded, thus
2621 overwriting the architecture dependent default
2624 - Frame Buffer Address:
2627 Define CONFIG_FB_ADDR if you want to use specific
2628 address for frame buffer.
2629 Then system will reserve the frame buffer address to
2630 defined address instead of lcd_setmem (this function
2631 grabs the memory for frame buffer by panel's size).
2633 Please see board_init_f function.
2635 - Automatic software updates via TFTP server
2637 CONFIG_UPDATE_TFTP_CNT_MAX
2638 CONFIG_UPDATE_TFTP_MSEC_MAX
2640 These options enable and control the auto-update feature;
2641 for a more detailed description refer to doc/README.update.
2643 - MTD Support (mtdparts command, UBI support)
2646 Adds the MTD device infrastructure from the Linux kernel.
2647 Needed for mtdparts command support.
2649 CONFIG_MTD_PARTITIONS
2651 Adds the MTD partitioning infrastructure from the Linux
2652 kernel. Needed for UBI support.
2656 Enable building of SPL globally.
2659 LDSCRIPT for linking the SPL binary.
2662 Maximum binary size (text, data and rodata) of the SPL binary.
2664 CONFIG_SPL_TEXT_BASE
2665 TEXT_BASE for linking the SPL binary.
2667 CONFIG_SPL_BSS_START_ADDR
2668 Link address for the BSS within the SPL binary.
2670 CONFIG_SPL_BSS_MAX_SIZE
2671 Maximum binary size of the BSS section of the SPL binary.
2674 Adress of the start of the stack SPL will use
2676 CONFIG_SYS_SPL_MALLOC_START
2677 Starting address of the malloc pool used in SPL.
2679 CONFIG_SYS_SPL_MALLOC_SIZE
2680 The size of the malloc pool used in SPL.
2682 CONFIG_SPL_FRAMEWORK
2683 Enable the SPL framework under common/. This framework
2684 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2685 NAND loading of the Linux Kernel.
2687 CONFIG_SPL_DISPLAY_PRINT
2688 For ARM, enable an optional function to print more information
2689 about the running system.
2691 CONFIG_SPL_LIBCOMMON_SUPPORT
2692 Support for common/libcommon.o in SPL binary
2694 CONFIG_SPL_LIBDISK_SUPPORT
2695 Support for disk/libdisk.o in SPL binary
2697 CONFIG_SPL_I2C_SUPPORT
2698 Support for drivers/i2c/libi2c.o in SPL binary
2700 CONFIG_SPL_GPIO_SUPPORT
2701 Support for drivers/gpio/libgpio.o in SPL binary
2703 CONFIG_SPL_MMC_SUPPORT
2704 Support for drivers/mmc/libmmc.o in SPL binary
2706 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2707 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2708 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2709 Address, size and partition on the MMC to load U-Boot from
2710 when the MMC is being used in raw mode.
2712 CONFIG_SPL_FAT_SUPPORT
2713 Support for fs/fat/libfat.o in SPL binary
2715 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2716 Filename to read to load U-Boot when reading from FAT
2718 CONFIG_SPL_NAND_SIMPLE
2719 Support for drivers/mtd/nand/libnand.o in SPL binary
2721 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2722 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2723 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2724 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2725 CONFIG_SYS_NAND_ECCBYTES
2726 Defines the size and behavior of the NAND that SPL uses
2727 to read U-Boot with CONFIG_SPL_NAND_SIMPLE
2729 CONFIG_SYS_NAND_U_BOOT_OFFS
2730 Location in NAND for CONFIG_SPL_NAND_SIMPLE to read U-Boot
2733 CONFIG_SYS_NAND_U_BOOT_START
2734 Location in memory for CONFIG_SPL_NAND_SIMPLE to load U-Boot
2737 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2738 Define this if you need to first read the OOB and then the
2739 data. This is used for example on davinci plattforms.
2741 CONFIG_SPL_OMAP3_ID_NAND
2742 Support for an OMAP3-specific set of functions to return the
2743 ID and MFR of the first attached NAND chip, if present.
2745 CONFIG_SPL_SERIAL_SUPPORT
2746 Support for drivers/serial/libserial.o in SPL binary
2748 CONFIG_SPL_SPI_FLASH_SUPPORT
2749 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2751 CONFIG_SPL_SPI_SUPPORT
2752 Support for drivers/spi/libspi.o in SPL binary
2754 CONFIG_SPL_RAM_DEVICE
2755 Support for running image already present in ram, in SPL binary
2757 CONFIG_SPL_LIBGENERIC_SUPPORT
2758 Support for lib/libgeneric.o in SPL binary
2763 [so far only for SMDK2400 boards]
2765 - Modem support enable:
2766 CONFIG_MODEM_SUPPORT
2768 - RTS/CTS Flow control enable:
2771 - Modem debug support:
2772 CONFIG_MODEM_SUPPORT_DEBUG
2774 Enables debugging stuff (char screen[1024], dbg())
2775 for modem support. Useful only with BDI2000.
2777 - Interrupt support (PPC):
2779 There are common interrupt_init() and timer_interrupt()
2780 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2781 for CPU specific initialization. interrupt_init_cpu()
2782 should set decrementer_count to appropriate value. If
2783 CPU resets decrementer automatically after interrupt
2784 (ppc4xx) it should set decrementer_count to zero.
2785 timer_interrupt() calls timer_interrupt_cpu() for CPU
2786 specific handling. If board has watchdog / status_led
2787 / other_activity_monitor it works automatically from
2788 general timer_interrupt().
2792 In the target system modem support is enabled when a
2793 specific key (key combination) is pressed during
2794 power-on. Otherwise U-Boot will boot normally
2795 (autoboot). The key_pressed() function is called from
2796 board_init(). Currently key_pressed() is a dummy
2797 function, returning 1 and thus enabling modem
2800 If there are no modem init strings in the
2801 environment, U-Boot proceed to autoboot; the
2802 previous output (banner, info printfs) will be
2805 See also: doc/README.Modem
2807 Board initialization settings:
2808 ------------------------------
2810 During Initialization u-boot calls a number of board specific functions
2811 to allow the preparation of board specific prerequisites, e.g. pin setup
2812 before drivers are initialized. To enable these callbacks the
2813 following configuration macros have to be defined. Currently this is
2814 architecture specific, so please check arch/your_architecture/lib/board.c
2815 typically in board_init_f() and board_init_r().
2817 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2818 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2819 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2820 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2822 Configuration Settings:
2823 -----------------------
2825 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2826 undefine this when you're short of memory.
2828 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2829 width of the commands listed in the 'help' command output.
2831 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2832 prompt for user input.
2834 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2836 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2838 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2840 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2841 the application (usually a Linux kernel) when it is
2844 - CONFIG_SYS_BAUDRATE_TABLE:
2845 List of legal baudrate settings for this board.
2847 - CONFIG_SYS_CONSOLE_INFO_QUIET
2848 Suppress display of console information at boot.
2850 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2851 If the board specific function
2852 extern int overwrite_console (void);
2853 returns 1, the stdin, stderr and stdout are switched to the
2854 serial port, else the settings in the environment are used.
2856 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2857 Enable the call to overwrite_console().
2859 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2860 Enable overwrite of previous console environment settings.
2862 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2863 Begin and End addresses of the area used by the
2866 - CONFIG_SYS_ALT_MEMTEST:
2867 Enable an alternate, more extensive memory test.
2869 - CONFIG_SYS_MEMTEST_SCRATCH:
2870 Scratch address used by the alternate memory test
2871 You only need to set this if address zero isn't writeable
2873 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2874 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2875 this specified memory area will get subtracted from the top
2876 (end) of RAM and won't get "touched" at all by U-Boot. By
2877 fixing up gd->ram_size the Linux kernel should gets passed
2878 the now "corrected" memory size and won't touch it either.
2879 This should work for arch/ppc and arch/powerpc. Only Linux
2880 board ports in arch/powerpc with bootwrapper support that
2881 recalculate the memory size from the SDRAM controller setup
2882 will have to get fixed in Linux additionally.
2884 This option can be used as a workaround for the 440EPx/GRx
2885 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2888 WARNING: Please make sure that this value is a multiple of
2889 the Linux page size (normally 4k). If this is not the case,
2890 then the end address of the Linux memory will be located at a
2891 non page size aligned address and this could cause major
2894 - CONFIG_SYS_TFTP_LOADADDR:
2895 Default load address for network file downloads
2897 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2898 Enable temporary baudrate change while serial download
2900 - CONFIG_SYS_SDRAM_BASE:
2901 Physical start address of SDRAM. _Must_ be 0 here.
2903 - CONFIG_SYS_MBIO_BASE:
2904 Physical start address of Motherboard I/O (if using a
2907 - CONFIG_SYS_FLASH_BASE:
2908 Physical start address of Flash memory.
2910 - CONFIG_SYS_MONITOR_BASE:
2911 Physical start address of boot monitor code (set by
2912 make config files to be same as the text base address
2913 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2914 CONFIG_SYS_FLASH_BASE when booting from flash.
2916 - CONFIG_SYS_MONITOR_LEN:
2917 Size of memory reserved for monitor code, used to
2918 determine _at_compile_time_ (!) if the environment is
2919 embedded within the U-Boot image, or in a separate
2922 - CONFIG_SYS_MALLOC_LEN:
2923 Size of DRAM reserved for malloc() use.
2925 - CONFIG_SYS_BOOTM_LEN:
2926 Normally compressed uImages are limited to an
2927 uncompressed size of 8 MBytes. If this is not enough,
2928 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2929 to adjust this setting to your needs.
2931 - CONFIG_SYS_BOOTMAPSZ:
2932 Maximum size of memory mapped by the startup code of
2933 the Linux kernel; all data that must be processed by
2934 the Linux kernel (bd_info, boot arguments, FDT blob if
2935 used) must be put below this limit, unless "bootm_low"
2936 enviroment variable is defined and non-zero. In such case
2937 all data for the Linux kernel must be between "bootm_low"
2938 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2939 variable "bootm_mapsize" will override the value of
2940 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2941 then the value in "bootm_size" will be used instead.
2943 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2944 Enable initrd_high functionality. If defined then the
2945 initrd_high feature is enabled and the bootm ramdisk subcommand
2948 - CONFIG_SYS_BOOT_GET_CMDLINE:
2949 Enables allocating and saving kernel cmdline in space between
2950 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2952 - CONFIG_SYS_BOOT_GET_KBD:
2953 Enables allocating and saving a kernel copy of the bd_info in
2954 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2956 - CONFIG_SYS_MAX_FLASH_BANKS:
2957 Max number of Flash memory banks
2959 - CONFIG_SYS_MAX_FLASH_SECT:
2960 Max number of sectors on a Flash chip
2962 - CONFIG_SYS_FLASH_ERASE_TOUT:
2963 Timeout for Flash erase operations (in ms)
2965 - CONFIG_SYS_FLASH_WRITE_TOUT:
2966 Timeout for Flash write operations (in ms)
2968 - CONFIG_SYS_FLASH_LOCK_TOUT
2969 Timeout for Flash set sector lock bit operation (in ms)
2971 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2972 Timeout for Flash clear lock bits operation (in ms)
2974 - CONFIG_SYS_FLASH_PROTECTION
2975 If defined, hardware flash sectors protection is used
2976 instead of U-Boot software protection.
2978 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2980 Enable TFTP transfers directly to flash memory;
2981 without this option such a download has to be
2982 performed in two steps: (1) download to RAM, and (2)
2983 copy from RAM to flash.
2985 The two-step approach is usually more reliable, since
2986 you can check if the download worked before you erase
2987 the flash, but in some situations (when system RAM is
2988 too limited to allow for a temporary copy of the
2989 downloaded image) this option may be very useful.
2991 - CONFIG_SYS_FLASH_CFI:
2992 Define if the flash driver uses extra elements in the
2993 common flash structure for storing flash geometry.
2995 - CONFIG_FLASH_CFI_DRIVER
2996 This option also enables the building of the cfi_flash driver
2997 in the drivers directory
2999 - CONFIG_FLASH_CFI_MTD
3000 This option enables the building of the cfi_mtd driver
3001 in the drivers directory. The driver exports CFI flash
3004 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3005 Use buffered writes to flash.
3007 - CONFIG_FLASH_SPANSION_S29WS_N
3008 s29ws-n MirrorBit flash has non-standard addresses for buffered
3011 - CONFIG_SYS_FLASH_QUIET_TEST
3012 If this option is defined, the common CFI flash doesn't
3013 print it's warning upon not recognized FLASH banks. This
3014 is useful, if some of the configured banks are only
3015 optionally available.
3017 - CONFIG_FLASH_SHOW_PROGRESS
3018 If defined (must be an integer), print out countdown
3019 digits and dots. Recommended value: 45 (9..1) for 80
3020 column displays, 15 (3..1) for 40 column displays.
3022 - CONFIG_SYS_RX_ETH_BUFFER:
3023 Defines the number of Ethernet receive buffers. On some
3024 Ethernet controllers it is recommended to set this value
3025 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3026 buffers can be full shortly after enabling the interface
3027 on high Ethernet traffic.
3028 Defaults to 4 if not defined.
3030 - CONFIG_ENV_MAX_ENTRIES
3032 Maximum number of entries in the hash table that is used
3033 internally to store the environment settings. The default
3034 setting is supposed to be generous and should work in most
3035 cases. This setting can be used to tune behaviour; see
3036 lib/hashtable.c for details.
3038 The following definitions that deal with the placement and management
3039 of environment data (variable area); in general, we support the
3040 following configurations:
3042 - CONFIG_BUILD_ENVCRC:
3044 Builds up envcrc with the target environment so that external utils
3045 may easily extract it and embed it in final U-Boot images.
3047 - CONFIG_ENV_IS_IN_FLASH:
3049 Define this if the environment is in flash memory.
3051 a) The environment occupies one whole flash sector, which is
3052 "embedded" in the text segment with the U-Boot code. This
3053 happens usually with "bottom boot sector" or "top boot
3054 sector" type flash chips, which have several smaller
3055 sectors at the start or the end. For instance, such a
3056 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3057 such a case you would place the environment in one of the
3058 4 kB sectors - with U-Boot code before and after it. With
3059 "top boot sector" type flash chips, you would put the
3060 environment in one of the last sectors, leaving a gap
3061 between U-Boot and the environment.
3063 - CONFIG_ENV_OFFSET:
3065 Offset of environment data (variable area) to the
3066 beginning of flash memory; for instance, with bottom boot
3067 type flash chips the second sector can be used: the offset
3068 for this sector is given here.
3070 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3074 This is just another way to specify the start address of
3075 the flash sector containing the environment (instead of
3078 - CONFIG_ENV_SECT_SIZE:
3080 Size of the sector containing the environment.
3083 b) Sometimes flash chips have few, equal sized, BIG sectors.
3084 In such a case you don't want to spend a whole sector for
3089 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3090 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3091 of this flash sector for the environment. This saves
3092 memory for the RAM copy of the environment.
3094 It may also save flash memory if you decide to use this
3095 when your environment is "embedded" within U-Boot code,
3096 since then the remainder of the flash sector could be used
3097 for U-Boot code. It should be pointed out that this is
3098 STRONGLY DISCOURAGED from a robustness point of view:
3099 updating the environment in flash makes it always
3100 necessary to erase the WHOLE sector. If something goes
3101 wrong before the contents has been restored from a copy in
3102 RAM, your target system will be dead.
3104 - CONFIG_ENV_ADDR_REDUND
3105 CONFIG_ENV_SIZE_REDUND
3107 These settings describe a second storage area used to hold
3108 a redundant copy of the environment data, so that there is
3109 a valid backup copy in case there is a power failure during
3110 a "saveenv" operation.
3112 BE CAREFUL! Any changes to the flash layout, and some changes to the
3113 source code will make it necessary to adapt <board>/u-boot.lds*
3117 - CONFIG_ENV_IS_IN_NVRAM:
3119 Define this if you have some non-volatile memory device
3120 (NVRAM, battery buffered SRAM) which you want to use for the
3126 These two #defines are used to determine the memory area you
3127 want to use for environment. It is assumed that this memory
3128 can just be read and written to, without any special
3131 BE CAREFUL! The first access to the environment happens quite early
3132 in U-Boot initalization (when we try to get the setting of for the
3133 console baudrate). You *MUST* have mapped your NVRAM area then, or
3136 Please note that even with NVRAM we still use a copy of the
3137 environment in RAM: we could work on NVRAM directly, but we want to
3138 keep settings there always unmodified except somebody uses "saveenv"
3139 to save the current settings.
3142 - CONFIG_ENV_IS_IN_EEPROM:
3144 Use this if you have an EEPROM or similar serial access
3145 device and a driver for it.
3147 - CONFIG_ENV_OFFSET:
3150 These two #defines specify the offset and size of the
3151 environment area within the total memory of your EEPROM.
3153 - CONFIG_SYS_I2C_EEPROM_ADDR:
3154 If defined, specified the chip address of the EEPROM device.
3155 The default address is zero.
3157 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3158 If defined, the number of bits used to address bytes in a
3159 single page in the EEPROM device. A 64 byte page, for example
3160 would require six bits.
3162 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3163 If defined, the number of milliseconds to delay between
3164 page writes. The default is zero milliseconds.
3166 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3167 The length in bytes of the EEPROM memory array address. Note
3168 that this is NOT the chip address length!
3170 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3171 EEPROM chips that implement "address overflow" are ones
3172 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3173 address and the extra bits end up in the "chip address" bit
3174 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3177 Note that we consider the length of the address field to
3178 still be one byte because the extra address bits are hidden
3179 in the chip address.
3181 - CONFIG_SYS_EEPROM_SIZE:
3182 The size in bytes of the EEPROM device.
3184 - CONFIG_ENV_EEPROM_IS_ON_I2C
3185 define this, if you have I2C and SPI activated, and your
3186 EEPROM, which holds the environment, is on the I2C bus.
3188 - CONFIG_I2C_ENV_EEPROM_BUS
3189 if you have an Environment on an EEPROM reached over
3190 I2C muxes, you can define here, how to reach this
3191 EEPROM. For example:
3193 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3195 EEPROM which holds the environment, is reached over
3196 a pca9547 i2c mux with address 0x70, channel 3.
3198 - CONFIG_ENV_IS_IN_DATAFLASH:
3200 Define this if you have a DataFlash memory device which you
3201 want to use for the environment.
3203 - CONFIG_ENV_OFFSET:
3207 These three #defines specify the offset and size of the
3208 environment area within the total memory of your DataFlash placed
3209 at the specified address.
3211 - CONFIG_ENV_IS_IN_REMOTE:
3213 Define this if you have a remote memory space which you
3214 want to use for the local device's environment.
3219 These two #defines specify the address and size of the
3220 environment area within the remote memory space. The
3221 local device can get the environment from remote memory
3222 space by SRIO or PCIE links.
3224 BE CAREFUL! For some special cases, the local device can not use
3225 "saveenv" command. For example, the local device will get the
3226 environment stored in a remote NOR flash by SRIO or PCIE link,
3227 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3229 - CONFIG_ENV_IS_IN_NAND:
3231 Define this if you have a NAND device which you want to use
3232 for the environment.
3234 - CONFIG_ENV_OFFSET:
3237 These two #defines specify the offset and size of the environment
3238 area within the first NAND device. CONFIG_ENV_OFFSET must be
3239 aligned to an erase block boundary.
3241 - CONFIG_ENV_OFFSET_REDUND (optional):
3243 This setting describes a second storage area of CONFIG_ENV_SIZE
3244 size used to hold a redundant copy of the environment data, so
3245 that there is a valid backup copy in case there is a power failure
3246 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3247 aligned to an erase block boundary.
3249 - CONFIG_ENV_RANGE (optional):
3251 Specifies the length of the region in which the environment
3252 can be written. This should be a multiple of the NAND device's
3253 block size. Specifying a range with more erase blocks than
3254 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3255 the range to be avoided.
3257 - CONFIG_ENV_OFFSET_OOB (optional):
3259 Enables support for dynamically retrieving the offset of the
3260 environment from block zero's out-of-band data. The
3261 "nand env.oob" command can be used to record this offset.
3262 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3263 using CONFIG_ENV_OFFSET_OOB.
3265 - CONFIG_NAND_ENV_DST
3267 Defines address in RAM to which the nand_spl code should copy the
3268 environment. If redundant environment is used, it will be copied to
3269 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3271 - CONFIG_SYS_SPI_INIT_OFFSET
3273 Defines offset to the initial SPI buffer area in DPRAM. The
3274 area is used at an early stage (ROM part) if the environment
3275 is configured to reside in the SPI EEPROM: We need a 520 byte
3276 scratch DPRAM area. It is used between the two initialization
3277 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3278 to be a good choice since it makes it far enough from the
3279 start of the data area as well as from the stack pointer.
3281 Please note that the environment is read-only until the monitor
3282 has been relocated to RAM and a RAM copy of the environment has been
3283 created; also, when using EEPROM you will have to use getenv_f()
3284 until then to read environment variables.
3286 The environment is protected by a CRC32 checksum. Before the monitor
3287 is relocated into RAM, as a result of a bad CRC you will be working
3288 with the compiled-in default environment - *silently*!!! [This is
3289 necessary, because the first environment variable we need is the
3290 "baudrate" setting for the console - if we have a bad CRC, we don't
3291 have any device yet where we could complain.]
3293 Note: once the monitor has been relocated, then it will complain if
3294 the default environment is used; a new CRC is computed as soon as you
3295 use the "saveenv" command to store a valid environment.
3297 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3298 Echo the inverted Ethernet link state to the fault LED.
3300 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3301 also needs to be defined.
3303 - CONFIG_SYS_FAULT_MII_ADDR:
3304 MII address of the PHY to check for the Ethernet link state.
3306 - CONFIG_NS16550_MIN_FUNCTIONS:
3307 Define this if you desire to only have use of the NS16550_init
3308 and NS16550_putc functions for the serial driver located at
3309 drivers/serial/ns16550.c. This option is useful for saving
3310 space for already greatly restricted images, including but not
3311 limited to NAND_SPL configurations.
3313 Low Level (hardware related) configuration options:
3314 ---------------------------------------------------
3316 - CONFIG_SYS_CACHELINE_SIZE:
3317 Cache Line Size of the CPU.
3319 - CONFIG_SYS_DEFAULT_IMMR:
3320 Default address of the IMMR after system reset.
3322 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3323 and RPXsuper) to be able to adjust the position of
3324 the IMMR register after a reset.
3326 - CONFIG_SYS_CCSRBAR_DEFAULT:
3327 Default (power-on reset) physical address of CCSR on Freescale
3330 - CONFIG_SYS_CCSRBAR:
3331 Virtual address of CCSR. On a 32-bit build, this is typically
3332 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3334 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3335 for cross-platform code that uses that macro instead.
3337 - CONFIG_SYS_CCSRBAR_PHYS:
3338 Physical address of CCSR. CCSR can be relocated to a new
3339 physical address, if desired. In this case, this macro should
3340 be set to that address. Otherwise, it should be set to the
3341 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3342 is typically relocated on 36-bit builds. It is recommended
3343 that this macro be defined via the _HIGH and _LOW macros:
3345 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3346 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3348 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3349 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3350 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3351 used in assembly code, so it must not contain typecasts or
3352 integer size suffixes (e.g. "ULL").
3354 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3355 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3356 used in assembly code, so it must not contain typecasts or
3357 integer size suffixes (e.g. "ULL").
3359 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3360 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3361 forced to a value that ensures that CCSR is not relocated.
3363 - Floppy Disk Support:
3364 CONFIG_SYS_FDC_DRIVE_NUMBER
3366 the default drive number (default value 0)
3368 CONFIG_SYS_ISA_IO_STRIDE
3370 defines the spacing between FDC chipset registers
3373 CONFIG_SYS_ISA_IO_OFFSET
3375 defines the offset of register from address. It
3376 depends on which part of the data bus is connected to
3377 the FDC chipset. (default value 0)
3379 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3380 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3383 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3384 fdc_hw_init() is called at the beginning of the FDC
3385 setup. fdc_hw_init() must be provided by the board
3386 source code. It is used to make hardware dependant
3390 Most IDE controllers were designed to be connected with PCI
3391 interface. Only few of them were designed for AHB interface.
3392 When software is doing ATA command and data transfer to
3393 IDE devices through IDE-AHB controller, some additional
3394 registers accessing to these kind of IDE-AHB controller
3397 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3398 DO NOT CHANGE unless you know exactly what you're
3399 doing! (11-4) [MPC8xx/82xx systems only]
3401 - CONFIG_SYS_INIT_RAM_ADDR:
3403 Start address of memory area that can be used for
3404 initial data and stack; please note that this must be
3405 writable memory that is working WITHOUT special
3406 initialization, i. e. you CANNOT use normal RAM which
3407 will become available only after programming the
3408 memory controller and running certain initialization
3411 U-Boot uses the following memory types:
3412 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3413 - MPC824X: data cache
3414 - PPC4xx: data cache
3416 - CONFIG_SYS_GBL_DATA_OFFSET:
3418 Offset of the initial data structure in the memory
3419 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3420 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3421 data is located at the end of the available space
3422 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3423 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3424 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3425 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3428 On the MPC824X (or other systems that use the data
3429 cache for initial memory) the address chosen for
3430 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3431 point to an otherwise UNUSED address space between
3432 the top of RAM and the start of the PCI space.
3434 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3436 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3438 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3440 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3442 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3444 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3446 - CONFIG_SYS_OR_TIMING_SDRAM:
3449 - CONFIG_SYS_MAMR_PTA:
3450 periodic timer for refresh
3452 - CONFIG_SYS_DER: Debug Event Register (37-47)
3454 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3455 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3456 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3457 CONFIG_SYS_BR1_PRELIM:
3458 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3460 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3461 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3462 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3463 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3465 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3466 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3467 Machine Mode Register and Memory Periodic Timer
3468 Prescaler definitions (SDRAM timing)
3470 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3471 enable I2C microcode relocation patch (MPC8xx);
3472 define relocation offset in DPRAM [DSP2]
3474 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3475 enable SMC microcode relocation patch (MPC8xx);
3476 define relocation offset in DPRAM [SMC1]
3478 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3479 enable SPI microcode relocation patch (MPC8xx);
3480 define relocation offset in DPRAM [SCC4]
3482 - CONFIG_SYS_USE_OSCCLK:
3483 Use OSCM clock mode on MBX8xx board. Be careful,
3484 wrong setting might damage your board. Read
3485 doc/README.MBX before setting this variable!
3487 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3488 Offset of the bootmode word in DPRAM used by post
3489 (Power On Self Tests). This definition overrides
3490 #define'd default value in commproc.h resp.
3493 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3494 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3495 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3496 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3497 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3498 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3499 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3500 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3501 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3503 - CONFIG_PCI_DISABLE_PCIE:
3504 Disable PCI-Express on systems where it is supported but not
3507 - CONFIG_PCI_ENUM_ONLY
3508 Only scan through and get the devices on the busses.
3509 Don't do any setup work, presumably because someone or
3510 something has already done it, and we don't need to do it
3511 a second time. Useful for platforms that are pre-booted
3512 by coreboot or similar.
3515 Chip has SRIO or not
3518 Board has SRIO 1 port available
3521 Board has SRIO 2 port available
3523 - CONFIG_SYS_SRIOn_MEM_VIRT:
3524 Virtual Address of SRIO port 'n' memory region
3526 - CONFIG_SYS_SRIOn_MEM_PHYS:
3527 Physical Address of SRIO port 'n' memory region
3529 - CONFIG_SYS_SRIOn_MEM_SIZE:
3530 Size of SRIO port 'n' memory region
3532 - CONFIG_SYS_NDFC_16
3533 Defined to tell the NDFC that the NAND chip is using a
3536 - CONFIG_SYS_NDFC_EBC0_CFG
3537 Sets the EBC0_CFG register for the NDFC. If not defined
3538 a default value will be used.
3541 Get DDR timing information from an I2C EEPROM. Common
3542 with pluggable memory modules such as SODIMMs
3545 I2C address of the SPD EEPROM
3547 - CONFIG_SYS_SPD_BUS_NUM
3548 If SPD EEPROM is on an I2C bus other than the first
3549 one, specify here. Note that the value must resolve
3550 to something your driver can deal with.
3552 - CONFIG_SYS_DDR_RAW_TIMING
3553 Get DDR timing information from other than SPD. Common with
3554 soldered DDR chips onboard without SPD. DDR raw timing
3555 parameters are extracted from datasheet and hard-coded into
3556 header files or board specific files.
3558 - CONFIG_FSL_DDR_INTERACTIVE
3559 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3561 - CONFIG_SYS_83XX_DDR_USES_CS0
3562 Only for 83xx systems. If specified, then DDR should
3563 be configured using CS0 and CS1 instead of CS2 and CS3.
3565 - CONFIG_ETHER_ON_FEC[12]
3566 Define to enable FEC[12] on a 8xx series processor.
3568 - CONFIG_FEC[12]_PHY
3569 Define to the hardcoded PHY address which corresponds
3570 to the given FEC; i. e.
3571 #define CONFIG_FEC1_PHY 4
3572 means that the PHY with address 4 is connected to FEC1
3574 When set to -1, means to probe for first available.
3576 - CONFIG_FEC[12]_PHY_NORXERR
3577 The PHY does not have a RXERR line (RMII only).
3578 (so program the FEC to ignore it).
3581 Enable RMII mode for all FECs.
3582 Note that this is a global option, we can't
3583 have one FEC in standard MII mode and another in RMII mode.
3585 - CONFIG_CRC32_VERIFY
3586 Add a verify option to the crc32 command.
3589 => crc32 -v <address> <count> <crc32>
3591 Where address/count indicate a memory area
3592 and crc32 is the correct crc32 which the
3596 Add the "loopw" memory command. This only takes effect if
3597 the memory commands are activated globally (CONFIG_CMD_MEM).
3600 Add the "mdc" and "mwc" memory commands. These are cyclic
3605 This command will print 4 bytes (10,11,12,13) each 500 ms.
3607 => mwc.l 100 12345678 10
3608 This command will write 12345678 to address 100 all 10 ms.
3610 This only takes effect if the memory commands are activated
3611 globally (CONFIG_CMD_MEM).
3613 - CONFIG_SKIP_LOWLEVEL_INIT
3614 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3615 low level initializations (like setting up the memory
3616 controller) are omitted and/or U-Boot does not
3617 relocate itself into RAM.
3619 Normally this variable MUST NOT be defined. The only
3620 exception is when U-Boot is loaded (to RAM) by some
3621 other boot loader or by a debugger which performs
3622 these initializations itself.
3625 Modifies the behaviour of start.S when compiling a loader
3626 that is executed before the actual U-Boot. E.g. when
3627 compiling a NAND SPL.
3629 - CONFIG_USE_ARCH_MEMCPY
3630 CONFIG_USE_ARCH_MEMSET
3631 If these options are used a optimized version of memcpy/memset will
3632 be used if available. These functions may be faster under some
3633 conditions but may increase the binary size.
3635 Freescale QE/FMAN Firmware Support:
3636 -----------------------------------
3638 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3639 loading of "firmware", which is encoded in the QE firmware binary format.
3640 This firmware often needs to be loaded during U-Boot booting, so macros
3641 are used to identify the storage device (NOR flash, SPI, etc) and the address
3644 - CONFIG_SYS_QE_FMAN_FW_ADDR
3645 The address in the storage device where the firmware is located. The
3646 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3649 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3650 The maximum possible size of the firmware. The firmware binary format
3651 has a field that specifies the actual size of the firmware, but it
3652 might not be possible to read any part of the firmware unless some
3653 local storage is allocated to hold the entire firmware first.
3655 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3656 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3657 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3658 virtual address in NOR flash.
3660 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3661 Specifies that QE/FMAN firmware is located in NAND flash.
3662 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3664 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3665 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3666 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3668 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3669 Specifies that QE/FMAN firmware is located on the primary SPI
3670 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3672 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3673 Specifies that QE/FMAN firmware is located in the remote (master)
3674 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3675 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3676 window->master inbound window->master LAW->the ucode address in
3677 master's memory space.
3679 Building the Software:
3680 ======================
3682 Building U-Boot has been tested in several native build environments
3683 and in many different cross environments. Of course we cannot support
3684 all possibly existing versions of cross development tools in all
3685 (potentially obsolete) versions. In case of tool chain problems we
3686 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3687 which is extensively used to build and test U-Boot.
3689 If you are not using a native environment, it is assumed that you
3690 have GNU cross compiling tools available in your path. In this case,
3691 you must set the environment variable CROSS_COMPILE in your shell.
3692 Note that no changes to the Makefile or any other source files are
3693 necessary. For example using the ELDK on a 4xx CPU, please enter:
3695 $ CROSS_COMPILE=ppc_4xx-
3696 $ export CROSS_COMPILE
3698 Note: If you wish to generate Windows versions of the utilities in
3699 the tools directory you can use the MinGW toolchain
3700 (http://www.mingw.org). Set your HOST tools to the MinGW
3701 toolchain and execute 'make tools'. For example:
3703 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3705 Binaries such as tools/mkimage.exe will be created which can
3706 be executed on computers running Windows.
3708 U-Boot is intended to be simple to build. After installing the
3709 sources you must configure U-Boot for one specific board type. This
3714 where "NAME_config" is the name of one of the existing configu-
3715 rations; see boards.cfg for supported names.
3717 Note: for some board special configuration names may exist; check if
3718 additional information is available from the board vendor; for
3719 instance, the TQM823L systems are available without (standard)
3720 or with LCD support. You can select such additional "features"
3721 when choosing the configuration, i. e.
3724 - will configure for a plain TQM823L, i. e. no LCD support
3726 make TQM823L_LCD_config
3727 - will configure for a TQM823L with U-Boot console on LCD
3732 Finally, type "make all", and you should get some working U-Boot
3733 images ready for download to / installation on your system:
3735 - "u-boot.bin" is a raw binary image
3736 - "u-boot" is an image in ELF binary format
3737 - "u-boot.srec" is in Motorola S-Record format
3739 By default the build is performed locally and the objects are saved
3740 in the source directory. One of the two methods can be used to change
3741 this behavior and build U-Boot to some external directory:
3743 1. Add O= to the make command line invocations:
3745 make O=/tmp/build distclean
3746 make O=/tmp/build NAME_config
3747 make O=/tmp/build all
3749 2. Set environment variable BUILD_DIR to point to the desired location:
3751 export BUILD_DIR=/tmp/build
3756 Note that the command line "O=" setting overrides the BUILD_DIR environment
3760 Please be aware that the Makefiles assume you are using GNU make, so
3761 for instance on NetBSD you might need to use "gmake" instead of
3765 If the system board that you have is not listed, then you will need
3766 to port U-Boot to your hardware platform. To do this, follow these
3769 1. Add a new configuration option for your board to the toplevel
3770 "boards.cfg" file, using the existing entries as examples.
3771 Follow the instructions there to keep the boards in order.
3772 2. Create a new directory to hold your board specific code. Add any
3773 files you need. In your board directory, you will need at least
3774 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3775 3. Create a new configuration file "include/configs/<board>.h" for
3777 3. If you're porting U-Boot to a new CPU, then also create a new
3778 directory to hold your CPU specific code. Add any files you need.
3779 4. Run "make <board>_config" with your new name.
3780 5. Type "make", and you should get a working "u-boot.srec" file
3781 to be installed on your target system.
3782 6. Debug and solve any problems that might arise.
3783 [Of course, this last step is much harder than it sounds.]
3786 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3787 ==============================================================
3789 If you have modified U-Boot sources (for instance added a new board
3790 or support for new devices, a new CPU, etc.) you are expected to
3791 provide feedback to the other developers. The feedback normally takes
3792 the form of a "patch", i. e. a context diff against a certain (latest
3793 official or latest in the git repository) version of U-Boot sources.
3795 But before you submit such a patch, please verify that your modifi-
3796 cation did not break existing code. At least make sure that *ALL* of
3797 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3798 just run the "MAKEALL" script, which will configure and build U-Boot
3799 for ALL supported system. Be warned, this will take a while. You can
3800 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3801 environment variable to the script, i. e. to use the ELDK cross tools
3804 CROSS_COMPILE=ppc_8xx- MAKEALL
3806 or to build on a native PowerPC system you can type
3808 CROSS_COMPILE=' ' MAKEALL
3810 When using the MAKEALL script, the default behaviour is to build
3811 U-Boot in the source directory. This location can be changed by
3812 setting the BUILD_DIR environment variable. Also, for each target
3813 built, the MAKEALL script saves two log files (<target>.ERR and
3814 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3815 location can be changed by setting the MAKEALL_LOGDIR environment
3816 variable. For example:
3818 export BUILD_DIR=/tmp/build
3819 export MAKEALL_LOGDIR=/tmp/log
3820 CROSS_COMPILE=ppc_8xx- MAKEALL
3822 With the above settings build objects are saved in the /tmp/build,
3823 log files are saved in the /tmp/log and the source tree remains clean
3824 during the whole build process.
3827 See also "U-Boot Porting Guide" below.
3830 Monitor Commands - Overview:
3831 ============================
3833 go - start application at address 'addr'
3834 run - run commands in an environment variable
3835 bootm - boot application image from memory
3836 bootp - boot image via network using BootP/TFTP protocol
3837 bootz - boot zImage from memory
3838 tftpboot- boot image via network using TFTP protocol
3839 and env variables "ipaddr" and "serverip"
3840 (and eventually "gatewayip")
3841 tftpput - upload a file via network using TFTP protocol
3842 rarpboot- boot image via network using RARP/TFTP protocol
3843 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3844 loads - load S-Record file over serial line
3845 loadb - load binary file over serial line (kermit mode)
3847 mm - memory modify (auto-incrementing)
3848 nm - memory modify (constant address)
3849 mw - memory write (fill)
3851 cmp - memory compare
3852 crc32 - checksum calculation
3853 i2c - I2C sub-system
3854 sspi - SPI utility commands
3855 base - print or set address offset
3856 printenv- print environment variables
3857 setenv - set environment variables
3858 saveenv - save environment variables to persistent storage
3859 protect - enable or disable FLASH write protection
3860 erase - erase FLASH memory
3861 flinfo - print FLASH memory information
3862 bdinfo - print Board Info structure
3863 iminfo - print header information for application image
3864 coninfo - print console devices and informations
3865 ide - IDE sub-system
3866 loop - infinite loop on address range
3867 loopw - infinite write loop on address range
3868 mtest - simple RAM test
3869 icache - enable or disable instruction cache
3870 dcache - enable or disable data cache
3871 reset - Perform RESET of the CPU
3872 echo - echo args to console
3873 version - print monitor version
3874 help - print online help
3875 ? - alias for 'help'
3878 Monitor Commands - Detailed Description:
3879 ========================================
3883 For now: just type "help <command>".
3886 Environment Variables:
3887 ======================
3889 U-Boot supports user configuration using Environment Variables which
3890 can be made persistent by saving to Flash memory.
3892 Environment Variables are set using "setenv", printed using
3893 "printenv", and saved to Flash using "saveenv". Using "setenv"
3894 without a value can be used to delete a variable from the
3895 environment. As long as you don't save the environment you are
3896 working with an in-memory copy. In case the Flash area containing the
3897 environment is erased by accident, a default environment is provided.
3899 Some configuration options can be set using Environment Variables.
3901 List of environment variables (most likely not complete):
3903 baudrate - see CONFIG_BAUDRATE
3905 bootdelay - see CONFIG_BOOTDELAY
3907 bootcmd - see CONFIG_BOOTCOMMAND
3909 bootargs - Boot arguments when booting an RTOS image
3911 bootfile - Name of the image to load with TFTP
3913 bootm_low - Memory range available for image processing in the bootm
3914 command can be restricted. This variable is given as
3915 a hexadecimal number and defines lowest address allowed
3916 for use by the bootm command. See also "bootm_size"
3917 environment variable. Address defined by "bootm_low" is
3918 also the base of the initial memory mapping for the Linux
3919 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3922 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3923 This variable is given as a hexadecimal number and it
3924 defines the size of the memory region starting at base
3925 address bootm_low that is accessible by the Linux kernel
3926 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3927 as the default value if it is defined, and bootm_size is
3930 bootm_size - Memory range available for image processing in the bootm
3931 command can be restricted. This variable is given as
3932 a hexadecimal number and defines the size of the region
3933 allowed for use by the bootm command. See also "bootm_low"
3934 environment variable.
3936 updatefile - Location of the software update file on a TFTP server, used
3937 by the automatic software update feature. Please refer to
3938 documentation in doc/README.update for more details.
3940 autoload - if set to "no" (any string beginning with 'n'),
3941 "bootp" will just load perform a lookup of the
3942 configuration from the BOOTP server, but not try to
3943 load any image using TFTP
3945 autostart - if set to "yes", an image loaded using the "bootp",
3946 "rarpboot", "tftpboot" or "diskboot" commands will
3947 be automatically started (by internally calling
3950 If set to "no", a standalone image passed to the
3951 "bootm" command will be copied to the load address
3952 (and eventually uncompressed), but NOT be started.
3953 This can be used to load and uncompress arbitrary
3956 fdt_high - if set this restricts the maximum address that the
3957 flattened device tree will be copied into upon boot.
3958 For example, if you have a system with 1 GB memory
3959 at physical address 0x10000000, while Linux kernel
3960 only recognizes the first 704 MB as low memory, you
3961 may need to set fdt_high as 0x3C000000 to have the
3962 device tree blob be copied to the maximum address
3963 of the 704 MB low memory, so that Linux kernel can
3964 access it during the boot procedure.
3966 If this is set to the special value 0xFFFFFFFF then
3967 the fdt will not be copied at all on boot. For this
3968 to work it must reside in writable memory, have
3969 sufficient padding on the end of it for u-boot to
3970 add the information it needs into it, and the memory
3971 must be accessible by the kernel.
3973 fdtcontroladdr- if set this is the address of the control flattened
3974 device tree used by U-Boot when CONFIG_OF_CONTROL is
3977 i2cfast - (PPC405GP|PPC405EP only)
3978 if set to 'y' configures Linux I2C driver for fast
3979 mode (400kHZ). This environment variable is used in
3980 initialization code. So, for changes to be effective
3981 it must be saved and board must be reset.
3983 initrd_high - restrict positioning of initrd images:
3984 If this variable is not set, initrd images will be
3985 copied to the highest possible address in RAM; this
3986 is usually what you want since it allows for
3987 maximum initrd size. If for some reason you want to
3988 make sure that the initrd image is loaded below the
3989 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3990 variable to a value of "no" or "off" or "0".
3991 Alternatively, you can set it to a maximum upper
3992 address to use (U-Boot will still check that it
3993 does not overwrite the U-Boot stack and data).
3995 For instance, when you have a system with 16 MB
3996 RAM, and want to reserve 4 MB from use by Linux,
3997 you can do this by adding "mem=12M" to the value of
3998 the "bootargs" variable. However, now you must make
3999 sure that the initrd image is placed in the first
4000 12 MB as well - this can be done with
4002 setenv initrd_high 00c00000
4004 If you set initrd_high to 0xFFFFFFFF, this is an
4005 indication to U-Boot that all addresses are legal
4006 for the Linux kernel, including addresses in flash
4007 memory. In this case U-Boot will NOT COPY the
4008 ramdisk at all. This may be useful to reduce the
4009 boot time on your system, but requires that this
4010 feature is supported by your Linux kernel.
4012 ipaddr - IP address; needed for tftpboot command
4014 loadaddr - Default load address for commands like "bootp",
4015 "rarpboot", "tftpboot", "loadb" or "diskboot"
4017 loads_echo - see CONFIG_LOADS_ECHO
4019 serverip - TFTP server IP address; needed for tftpboot command
4021 bootretry - see CONFIG_BOOT_RETRY_TIME
4023 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4025 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4027 ethprime - controls which interface is used first.
4029 ethact - controls which interface is currently active.
4030 For example you can do the following
4032 => setenv ethact FEC
4033 => ping 192.168.0.1 # traffic sent on FEC
4034 => setenv ethact SCC
4035 => ping 10.0.0.1 # traffic sent on SCC
4037 ethrotate - When set to "no" U-Boot does not go through all
4038 available network interfaces.
4039 It just stays at the currently selected interface.
4041 netretry - When set to "no" each network operation will
4042 either succeed or fail without retrying.
4043 When set to "once" the network operation will
4044 fail when all the available network interfaces
4045 are tried once without success.
4046 Useful on scripts which control the retry operation
4049 npe_ucode - set load address for the NPE microcode
4051 tftpsrcport - If this is set, the value is used for TFTP's
4054 tftpdstport - If this is set, the value is used for TFTP's UDP
4055 destination port instead of the Well Know Port 69.
4057 tftpblocksize - Block size to use for TFTP transfers; if not set,
4058 we use the TFTP server's default block size
4060 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4061 seconds, minimum value is 1000 = 1 second). Defines
4062 when a packet is considered to be lost so it has to
4063 be retransmitted. The default is 5000 = 5 seconds.
4064 Lowering this value may make downloads succeed
4065 faster in networks with high packet loss rates or
4066 with unreliable TFTP servers.
4068 vlan - When set to a value < 4095 the traffic over
4069 Ethernet is encapsulated/received over 802.1q
4072 The following image location variables contain the location of images
4073 used in booting. The "Image" column gives the role of the image and is
4074 not an environment variable name. The other columns are environment
4075 variable names. "File Name" gives the name of the file on a TFTP
4076 server, "RAM Address" gives the location in RAM the image will be
4077 loaded to, and "Flash Location" gives the image's address in NOR
4078 flash or offset in NAND flash.
4080 *Note* - these variables don't have to be defined for all boards, some
4081 boards currenlty use other variables for these purposes, and some
4082 boards use these variables for other purposes.
4084 Image File Name RAM Address Flash Location
4085 ----- --------- ----------- --------------
4086 u-boot u-boot u-boot_addr_r u-boot_addr
4087 Linux kernel bootfile kernel_addr_r kernel_addr
4088 device tree blob fdtfile fdt_addr_r fdt_addr
4089 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4091 The following environment variables may be used and automatically
4092 updated by the network boot commands ("bootp" and "rarpboot"),
4093 depending the information provided by your boot server:
4095 bootfile - see above
4096 dnsip - IP address of your Domain Name Server
4097 dnsip2 - IP address of your secondary Domain Name Server
4098 gatewayip - IP address of the Gateway (Router) to use
4099 hostname - Target hostname
4101 netmask - Subnet Mask
4102 rootpath - Pathname of the root filesystem on the NFS server
4103 serverip - see above
4106 There are two special Environment Variables:
4108 serial# - contains hardware identification information such
4109 as type string and/or serial number
4110 ethaddr - Ethernet address
4112 These variables can be set only once (usually during manufacturing of
4113 the board). U-Boot refuses to delete or overwrite these variables
4114 once they have been set once.
4117 Further special Environment Variables:
4119 ver - Contains the U-Boot version string as printed
4120 with the "version" command. This variable is
4121 readonly (see CONFIG_VERSION_VARIABLE).
4124 Please note that changes to some configuration parameters may take
4125 only effect after the next boot (yes, that's just like Windoze :-).
4128 Command Line Parsing:
4129 =====================
4131 There are two different command line parsers available with U-Boot:
4132 the old "simple" one, and the much more powerful "hush" shell:
4134 Old, simple command line parser:
4135 --------------------------------
4137 - supports environment variables (through setenv / saveenv commands)
4138 - several commands on one line, separated by ';'
4139 - variable substitution using "... ${name} ..." syntax
4140 - special characters ('$', ';') can be escaped by prefixing with '\',
4142 setenv bootcmd bootm \${address}
4143 - You can also escape text by enclosing in single apostrophes, for example:
4144 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4149 - similar to Bourne shell, with control structures like
4150 if...then...else...fi, for...do...done; while...do...done,
4151 until...do...done, ...
4152 - supports environment ("global") variables (through setenv / saveenv
4153 commands) and local shell variables (through standard shell syntax
4154 "name=value"); only environment variables can be used with "run"
4160 (1) If a command line (or an environment variable executed by a "run"
4161 command) contains several commands separated by semicolon, and
4162 one of these commands fails, then the remaining commands will be
4165 (2) If you execute several variables with one call to run (i. e.
4166 calling run with a list of variables as arguments), any failing
4167 command will cause "run" to terminate, i. e. the remaining
4168 variables are not executed.
4170 Note for Redundant Ethernet Interfaces:
4171 =======================================
4173 Some boards come with redundant Ethernet interfaces; U-Boot supports
4174 such configurations and is capable of automatic selection of a
4175 "working" interface when needed. MAC assignment works as follows:
4177 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4178 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4179 "eth1addr" (=>eth1), "eth2addr", ...
4181 If the network interface stores some valid MAC address (for instance
4182 in SROM), this is used as default address if there is NO correspon-
4183 ding setting in the environment; if the corresponding environment
4184 variable is set, this overrides the settings in the card; that means:
4186 o If the SROM has a valid MAC address, and there is no address in the
4187 environment, the SROM's address is used.
4189 o If there is no valid address in the SROM, and a definition in the
4190 environment exists, then the value from the environment variable is
4193 o If both the SROM and the environment contain a MAC address, and
4194 both addresses are the same, this MAC address is used.
4196 o If both the SROM and the environment contain a MAC address, and the
4197 addresses differ, the value from the environment is used and a
4200 o If neither SROM nor the environment contain a MAC address, an error
4203 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4204 will be programmed into hardware as part of the initialization process. This
4205 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4206 The naming convention is as follows:
4207 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4212 U-Boot is capable of booting (and performing other auxiliary operations on)
4213 images in two formats:
4215 New uImage format (FIT)
4216 -----------------------
4218 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4219 to Flattened Device Tree). It allows the use of images with multiple
4220 components (several kernels, ramdisks, etc.), with contents protected by
4221 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4227 Old image format is based on binary files which can be basically anything,
4228 preceded by a special header; see the definitions in include/image.h for
4229 details; basically, the header defines the following image properties:
4231 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4232 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4233 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4234 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4236 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4237 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4238 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4239 * Compression Type (uncompressed, gzip, bzip2)
4245 The header is marked by a special Magic Number, and both the header
4246 and the data portions of the image are secured against corruption by
4253 Although U-Boot should support any OS or standalone application
4254 easily, the main focus has always been on Linux during the design of
4257 U-Boot includes many features that so far have been part of some
4258 special "boot loader" code within the Linux kernel. Also, any
4259 "initrd" images to be used are no longer part of one big Linux image;
4260 instead, kernel and "initrd" are separate images. This implementation
4261 serves several purposes:
4263 - the same features can be used for other OS or standalone
4264 applications (for instance: using compressed images to reduce the
4265 Flash memory footprint)
4267 - it becomes much easier to port new Linux kernel versions because
4268 lots of low-level, hardware dependent stuff are done by U-Boot
4270 - the same Linux kernel image can now be used with different "initrd"
4271 images; of course this also means that different kernel images can
4272 be run with the same "initrd". This makes testing easier (you don't
4273 have to build a new "zImage.initrd" Linux image when you just
4274 change a file in your "initrd"). Also, a field-upgrade of the
4275 software is easier now.
4281 Porting Linux to U-Boot based systems:
4282 ---------------------------------------
4284 U-Boot cannot save you from doing all the necessary modifications to
4285 configure the Linux device drivers for use with your target hardware
4286 (no, we don't intend to provide a full virtual machine interface to
4289 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4291 Just make sure your machine specific header file (for instance
4292 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4293 Information structure as we define in include/asm-<arch>/u-boot.h,
4294 and make sure that your definition of IMAP_ADDR uses the same value
4295 as your U-Boot configuration in CONFIG_SYS_IMMR.
4298 Configuring the Linux kernel:
4299 -----------------------------
4301 No specific requirements for U-Boot. Make sure you have some root
4302 device (initial ramdisk, NFS) for your target system.
4305 Building a Linux Image:
4306 -----------------------
4308 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4309 not used. If you use recent kernel source, a new build target
4310 "uImage" will exist which automatically builds an image usable by
4311 U-Boot. Most older kernels also have support for a "pImage" target,
4312 which was introduced for our predecessor project PPCBoot and uses a
4313 100% compatible format.
4322 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4323 encapsulate a compressed Linux kernel image with header information,
4324 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4326 * build a standard "vmlinux" kernel image (in ELF binary format):
4328 * convert the kernel into a raw binary image:
4330 ${CROSS_COMPILE}-objcopy -O binary \
4331 -R .note -R .comment \
4332 -S vmlinux linux.bin
4334 * compress the binary image:
4338 * package compressed binary image for U-Boot:
4340 mkimage -A ppc -O linux -T kernel -C gzip \
4341 -a 0 -e 0 -n "Linux Kernel Image" \
4342 -d linux.bin.gz uImage
4345 The "mkimage" tool can also be used to create ramdisk images for use
4346 with U-Boot, either separated from the Linux kernel image, or
4347 combined into one file. "mkimage" encapsulates the images with a 64
4348 byte header containing information about target architecture,
4349 operating system, image type, compression method, entry points, time
4350 stamp, CRC32 checksums, etc.
4352 "mkimage" can be called in two ways: to verify existing images and
4353 print the header information, or to build new images.
4355 In the first form (with "-l" option) mkimage lists the information
4356 contained in the header of an existing U-Boot image; this includes
4357 checksum verification:
4359 tools/mkimage -l image
4360 -l ==> list image header information
4362 The second form (with "-d" option) is used to build a U-Boot image
4363 from a "data file" which is used as image payload:
4365 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4366 -n name -d data_file image
4367 -A ==> set architecture to 'arch'
4368 -O ==> set operating system to 'os'
4369 -T ==> set image type to 'type'
4370 -C ==> set compression type 'comp'
4371 -a ==> set load address to 'addr' (hex)
4372 -e ==> set entry point to 'ep' (hex)
4373 -n ==> set image name to 'name'
4374 -d ==> use image data from 'datafile'
4376 Right now, all Linux kernels for PowerPC systems use the same load
4377 address (0x00000000), but the entry point address depends on the
4380 - 2.2.x kernels have the entry point at 0x0000000C,
4381 - 2.3.x and later kernels have the entry point at 0x00000000.
4383 So a typical call to build a U-Boot image would read:
4385 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4386 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4387 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4388 > examples/uImage.TQM850L
4389 Image Name: 2.4.4 kernel for TQM850L
4390 Created: Wed Jul 19 02:34:59 2000
4391 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4392 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4393 Load Address: 0x00000000
4394 Entry Point: 0x00000000
4396 To verify the contents of the image (or check for corruption):
4398 -> tools/mkimage -l examples/uImage.TQM850L
4399 Image Name: 2.4.4 kernel for TQM850L
4400 Created: Wed Jul 19 02:34:59 2000
4401 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4402 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4403 Load Address: 0x00000000
4404 Entry Point: 0x00000000
4406 NOTE: for embedded systems where boot time is critical you can trade
4407 speed for memory and install an UNCOMPRESSED image instead: this
4408 needs more space in Flash, but boots much faster since it does not
4409 need to be uncompressed:
4411 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4412 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4413 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4414 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4415 > examples/uImage.TQM850L-uncompressed
4416 Image Name: 2.4.4 kernel for TQM850L
4417 Created: Wed Jul 19 02:34:59 2000
4418 Image Type: PowerPC Linux Kernel Image (uncompressed)
4419 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4420 Load Address: 0x00000000
4421 Entry Point: 0x00000000
4424 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4425 when your kernel is intended to use an initial ramdisk:
4427 -> tools/mkimage -n 'Simple Ramdisk Image' \
4428 > -A ppc -O linux -T ramdisk -C gzip \
4429 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4430 Image Name: Simple Ramdisk Image
4431 Created: Wed Jan 12 14:01:50 2000
4432 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4433 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4434 Load Address: 0x00000000
4435 Entry Point: 0x00000000
4438 Installing a Linux Image:
4439 -------------------------
4441 To downloading a U-Boot image over the serial (console) interface,
4442 you must convert the image to S-Record format:
4444 objcopy -I binary -O srec examples/image examples/image.srec
4446 The 'objcopy' does not understand the information in the U-Boot
4447 image header, so the resulting S-Record file will be relative to
4448 address 0x00000000. To load it to a given address, you need to
4449 specify the target address as 'offset' parameter with the 'loads'
4452 Example: install the image to address 0x40100000 (which on the
4453 TQM8xxL is in the first Flash bank):
4455 => erase 40100000 401FFFFF
4461 ## Ready for S-Record download ...
4462 ~>examples/image.srec
4463 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4465 15989 15990 15991 15992
4466 [file transfer complete]
4468 ## Start Addr = 0x00000000
4471 You can check the success of the download using the 'iminfo' command;
4472 this includes a checksum verification so you can be sure no data
4473 corruption happened:
4477 ## Checking Image at 40100000 ...
4478 Image Name: 2.2.13 for initrd on TQM850L
4479 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4480 Data Size: 335725 Bytes = 327 kB = 0 MB
4481 Load Address: 00000000
4482 Entry Point: 0000000c
4483 Verifying Checksum ... OK
4489 The "bootm" command is used to boot an application that is stored in
4490 memory (RAM or Flash). In case of a Linux kernel image, the contents
4491 of the "bootargs" environment variable is passed to the kernel as
4492 parameters. You can check and modify this variable using the
4493 "printenv" and "setenv" commands:
4496 => printenv bootargs
4497 bootargs=root=/dev/ram
4499 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4501 => printenv bootargs
4502 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4505 ## Booting Linux kernel at 40020000 ...
4506 Image Name: 2.2.13 for NFS on TQM850L
4507 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4508 Data Size: 381681 Bytes = 372 kB = 0 MB
4509 Load Address: 00000000
4510 Entry Point: 0000000c
4511 Verifying Checksum ... OK
4512 Uncompressing Kernel Image ... OK
4513 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
4514 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4515 time_init: decrementer frequency = 187500000/60
4516 Calibrating delay loop... 49.77 BogoMIPS
4517 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4520 If you want to boot a Linux kernel with initial RAM disk, you pass
4521 the memory addresses of both the kernel and the initrd image (PPBCOOT
4522 format!) to the "bootm" command:
4524 => imi 40100000 40200000
4526 ## Checking Image at 40100000 ...
4527 Image Name: 2.2.13 for initrd on TQM850L
4528 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4529 Data Size: 335725 Bytes = 327 kB = 0 MB
4530 Load Address: 00000000
4531 Entry Point: 0000000c
4532 Verifying Checksum ... OK
4534 ## Checking Image at 40200000 ...
4535 Image Name: Simple Ramdisk Image
4536 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4537 Data Size: 566530 Bytes = 553 kB = 0 MB
4538 Load Address: 00000000
4539 Entry Point: 00000000
4540 Verifying Checksum ... OK
4542 => bootm 40100000 40200000
4543 ## Booting Linux kernel at 40100000 ...
4544 Image Name: 2.2.13 for initrd on TQM850L
4545 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4546 Data Size: 335725 Bytes = 327 kB = 0 MB
4547 Load Address: 00000000
4548 Entry Point: 0000000c
4549 Verifying Checksum ... OK
4550 Uncompressing Kernel Image ... OK
4551 ## Loading RAMDisk Image at 40200000 ...
4552 Image Name: Simple Ramdisk Image
4553 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4554 Data Size: 566530 Bytes = 553 kB = 0 MB
4555 Load Address: 00000000
4556 Entry Point: 00000000
4557 Verifying Checksum ... OK
4558 Loading Ramdisk ... OK
4559 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
4560 Boot arguments: root=/dev/ram
4561 time_init: decrementer frequency = 187500000/60
4562 Calibrating delay loop... 49.77 BogoMIPS
4564 RAMDISK: Compressed image found at block 0
4565 VFS: Mounted root (ext2 filesystem).
4569 Boot Linux and pass a flat device tree:
4572 First, U-Boot must be compiled with the appropriate defines. See the section
4573 titled "Linux Kernel Interface" above for a more in depth explanation. The
4574 following is an example of how to start a kernel and pass an updated
4580 oft=oftrees/mpc8540ads.dtb
4581 => tftp $oftaddr $oft
4582 Speed: 1000, full duplex
4584 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4585 Filename 'oftrees/mpc8540ads.dtb'.
4586 Load address: 0x300000
4589 Bytes transferred = 4106 (100a hex)
4590 => tftp $loadaddr $bootfile
4591 Speed: 1000, full duplex
4593 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4595 Load address: 0x200000
4596 Loading:############
4598 Bytes transferred = 1029407 (fb51f hex)
4603 => bootm $loadaddr - $oftaddr
4604 ## Booting image at 00200000 ...
4605 Image Name: Linux-2.6.17-dirty
4606 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4607 Data Size: 1029343 Bytes = 1005.2 kB
4608 Load Address: 00000000
4609 Entry Point: 00000000
4610 Verifying Checksum ... OK
4611 Uncompressing Kernel Image ... OK
4612 Booting using flat device tree at 0x300000
4613 Using MPC85xx ADS machine description
4614 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4618 More About U-Boot Image Types:
4619 ------------------------------
4621 U-Boot supports the following image types:
4623 "Standalone Programs" are directly runnable in the environment
4624 provided by U-Boot; it is expected that (if they behave
4625 well) you can continue to work in U-Boot after return from
4626 the Standalone Program.
4627 "OS Kernel Images" are usually images of some Embedded OS which
4628 will take over control completely. Usually these programs
4629 will install their own set of exception handlers, device
4630 drivers, set up the MMU, etc. - this means, that you cannot
4631 expect to re-enter U-Boot except by resetting the CPU.
4632 "RAMDisk Images" are more or less just data blocks, and their
4633 parameters (address, size) are passed to an OS kernel that is
4635 "Multi-File Images" contain several images, typically an OS
4636 (Linux) kernel image and one or more data images like
4637 RAMDisks. This construct is useful for instance when you want
4638 to boot over the network using BOOTP etc., where the boot
4639 server provides just a single image file, but you want to get
4640 for instance an OS kernel and a RAMDisk image.
4642 "Multi-File Images" start with a list of image sizes, each
4643 image size (in bytes) specified by an "uint32_t" in network
4644 byte order. This list is terminated by an "(uint32_t)0".
4645 Immediately after the terminating 0 follow the images, one by
4646 one, all aligned on "uint32_t" boundaries (size rounded up to
4647 a multiple of 4 bytes).
4649 "Firmware Images" are binary images containing firmware (like
4650 U-Boot or FPGA images) which usually will be programmed to
4653 "Script files" are command sequences that will be executed by
4654 U-Boot's command interpreter; this feature is especially
4655 useful when you configure U-Boot to use a real shell (hush)
4656 as command interpreter.
4658 Booting the Linux zImage:
4659 -------------------------
4661 On some platforms, it's possible to boot Linux zImage. This is done
4662 using the "bootz" command. The syntax of "bootz" command is the same
4663 as the syntax of "bootm" command.
4665 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4666 kernel with raw initrd images. The syntax is slightly different, the
4667 address of the initrd must be augmented by it's size, in the following
4668 format: "<initrd addres>:<initrd size>".
4674 One of the features of U-Boot is that you can dynamically load and
4675 run "standalone" applications, which can use some resources of
4676 U-Boot like console I/O functions or interrupt services.
4678 Two simple examples are included with the sources:
4683 'examples/hello_world.c' contains a small "Hello World" Demo
4684 application; it is automatically compiled when you build U-Boot.
4685 It's configured to run at address 0x00040004, so you can play with it
4689 ## Ready for S-Record download ...
4690 ~>examples/hello_world.srec
4691 1 2 3 4 5 6 7 8 9 10 11 ...
4692 [file transfer complete]
4694 ## Start Addr = 0x00040004
4696 => go 40004 Hello World! This is a test.
4697 ## Starting application at 0x00040004 ...
4708 Hit any key to exit ...
4710 ## Application terminated, rc = 0x0
4712 Another example, which demonstrates how to register a CPM interrupt
4713 handler with the U-Boot code, can be found in 'examples/timer.c'.
4714 Here, a CPM timer is set up to generate an interrupt every second.
4715 The interrupt service routine is trivial, just printing a '.'
4716 character, but this is just a demo program. The application can be
4717 controlled by the following keys:
4719 ? - print current values og the CPM Timer registers
4720 b - enable interrupts and start timer
4721 e - stop timer and disable interrupts
4722 q - quit application
4725 ## Ready for S-Record download ...
4726 ~>examples/timer.srec
4727 1 2 3 4 5 6 7 8 9 10 11 ...
4728 [file transfer complete]
4730 ## Start Addr = 0x00040004
4733 ## Starting application at 0x00040004 ...
4736 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4739 [q, b, e, ?] Set interval 1000000 us
4742 [q, b, e, ?] ........
4743 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4746 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4749 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4752 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4754 [q, b, e, ?] ...Stopping timer
4756 [q, b, e, ?] ## Application terminated, rc = 0x0
4762 Over time, many people have reported problems when trying to use the
4763 "minicom" terminal emulation program for serial download. I (wd)
4764 consider minicom to be broken, and recommend not to use it. Under
4765 Unix, I recommend to use C-Kermit for general purpose use (and
4766 especially for kermit binary protocol download ("loadb" command), and
4767 use "cu" for S-Record download ("loads" command). See
4768 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4769 for help with kermit.
4772 Nevertheless, if you absolutely want to use it try adding this
4773 configuration to your "File transfer protocols" section:
4775 Name Program Name U/D FullScr IO-Red. Multi
4776 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4777 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4783 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4784 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4786 Building requires a cross environment; it is known to work on
4787 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4788 need gmake since the Makefiles are not compatible with BSD make).
4789 Note that the cross-powerpc package does not install include files;
4790 attempting to build U-Boot will fail because <machine/ansi.h> is
4791 missing. This file has to be installed and patched manually:
4793 # cd /usr/pkg/cross/powerpc-netbsd/include
4795 # ln -s powerpc machine
4796 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4797 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4799 Native builds *don't* work due to incompatibilities between native
4800 and U-Boot include files.
4802 Booting assumes that (the first part of) the image booted is a
4803 stage-2 loader which in turn loads and then invokes the kernel
4804 proper. Loader sources will eventually appear in the NetBSD source
4805 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4806 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4809 Implementation Internals:
4810 =========================
4812 The following is not intended to be a complete description of every
4813 implementation detail. However, it should help to understand the
4814 inner workings of U-Boot and make it easier to port it to custom
4818 Initial Stack, Global Data:
4819 ---------------------------
4821 The implementation of U-Boot is complicated by the fact that U-Boot
4822 starts running out of ROM (flash memory), usually without access to
4823 system RAM (because the memory controller is not initialized yet).
4824 This means that we don't have writable Data or BSS segments, and BSS
4825 is not initialized as zero. To be able to get a C environment working
4826 at all, we have to allocate at least a minimal stack. Implementation
4827 options for this are defined and restricted by the CPU used: Some CPU
4828 models provide on-chip memory (like the IMMR area on MPC8xx and
4829 MPC826x processors), on others (parts of) the data cache can be
4830 locked as (mis-) used as memory, etc.
4832 Chris Hallinan posted a good summary of these issues to the
4833 U-Boot mailing list:
4835 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4836 From: "Chris Hallinan" <clh@net1plus.com>
4837 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4840 Correct me if I'm wrong, folks, but the way I understand it
4841 is this: Using DCACHE as initial RAM for Stack, etc, does not
4842 require any physical RAM backing up the cache. The cleverness
4843 is that the cache is being used as a temporary supply of
4844 necessary storage before the SDRAM controller is setup. It's
4845 beyond the scope of this list to explain the details, but you
4846 can see how this works by studying the cache architecture and
4847 operation in the architecture and processor-specific manuals.
4849 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4850 is another option for the system designer to use as an
4851 initial stack/RAM area prior to SDRAM being available. Either
4852 option should work for you. Using CS 4 should be fine if your
4853 board designers haven't used it for something that would
4854 cause you grief during the initial boot! It is frequently not
4857 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4858 with your processor/board/system design. The default value
4859 you will find in any recent u-boot distribution in
4860 walnut.h should work for you. I'd set it to a value larger
4861 than your SDRAM module. If you have a 64MB SDRAM module, set
4862 it above 400_0000. Just make sure your board has no resources
4863 that are supposed to respond to that address! That code in
4864 start.S has been around a while and should work as is when
4865 you get the config right.
4870 It is essential to remember this, since it has some impact on the C
4871 code for the initialization procedures:
4873 * Initialized global data (data segment) is read-only. Do not attempt
4876 * Do not use any uninitialized global data (or implicitely initialized
4877 as zero data - BSS segment) at all - this is undefined, initiali-
4878 zation is performed later (when relocating to RAM).
4880 * Stack space is very limited. Avoid big data buffers or things like
4883 Having only the stack as writable memory limits means we cannot use
4884 normal global data to share information beween the code. But it
4885 turned out that the implementation of U-Boot can be greatly
4886 simplified by making a global data structure (gd_t) available to all
4887 functions. We could pass a pointer to this data as argument to _all_
4888 functions, but this would bloat the code. Instead we use a feature of
4889 the GCC compiler (Global Register Variables) to share the data: we
4890 place a pointer (gd) to the global data into a register which we
4891 reserve for this purpose.
4893 When choosing a register for such a purpose we are restricted by the
4894 relevant (E)ABI specifications for the current architecture, and by
4895 GCC's implementation.
4897 For PowerPC, the following registers have specific use:
4899 R2: reserved for system use
4900 R3-R4: parameter passing and return values
4901 R5-R10: parameter passing
4902 R13: small data area pointer
4906 (U-Boot also uses R12 as internal GOT pointer. r12
4907 is a volatile register so r12 needs to be reset when
4908 going back and forth between asm and C)
4910 ==> U-Boot will use R2 to hold a pointer to the global data
4912 Note: on PPC, we could use a static initializer (since the
4913 address of the global data structure is known at compile time),
4914 but it turned out that reserving a register results in somewhat
4915 smaller code - although the code savings are not that big (on
4916 average for all boards 752 bytes for the whole U-Boot image,
4917 624 text + 127 data).
4919 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4920 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4922 ==> U-Boot will use P3 to hold a pointer to the global data
4924 On ARM, the following registers are used:
4926 R0: function argument word/integer result
4927 R1-R3: function argument word
4929 R10: stack limit (used only if stack checking if enabled)
4930 R11: argument (frame) pointer
4931 R12: temporary workspace
4934 R15: program counter
4936 ==> U-Boot will use R8 to hold a pointer to the global data
4938 On Nios II, the ABI is documented here:
4939 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4941 ==> U-Boot will use gp to hold a pointer to the global data
4943 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4944 to access small data sections, so gp is free.
4946 On NDS32, the following registers are used:
4948 R0-R1: argument/return
4950 R15: temporary register for assembler
4951 R16: trampoline register
4952 R28: frame pointer (FP)
4953 R29: global pointer (GP)
4954 R30: link register (LP)
4955 R31: stack pointer (SP)
4956 PC: program counter (PC)
4958 ==> U-Boot will use R10 to hold a pointer to the global data
4960 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4961 or current versions of GCC may "optimize" the code too much.
4966 U-Boot runs in system state and uses physical addresses, i.e. the
4967 MMU is not used either for address mapping nor for memory protection.
4969 The available memory is mapped to fixed addresses using the memory
4970 controller. In this process, a contiguous block is formed for each
4971 memory type (Flash, SDRAM, SRAM), even when it consists of several
4972 physical memory banks.
4974 U-Boot is installed in the first 128 kB of the first Flash bank (on
4975 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4976 booting and sizing and initializing DRAM, the code relocates itself
4977 to the upper end of DRAM. Immediately below the U-Boot code some
4978 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4979 configuration setting]. Below that, a structure with global Board
4980 Info data is placed, followed by the stack (growing downward).
4982 Additionally, some exception handler code is copied to the low 8 kB
4983 of DRAM (0x00000000 ... 0x00001FFF).
4985 So a typical memory configuration with 16 MB of DRAM could look like
4988 0x0000 0000 Exception Vector code
4991 0x0000 2000 Free for Application Use
4997 0x00FB FF20 Monitor Stack (Growing downward)
4998 0x00FB FFAC Board Info Data and permanent copy of global data
4999 0x00FC 0000 Malloc Arena
5002 0x00FE 0000 RAM Copy of Monitor Code
5003 ... eventually: LCD or video framebuffer
5004 ... eventually: pRAM (Protected RAM - unchanged by reset)
5005 0x00FF FFFF [End of RAM]
5008 System Initialization:
5009 ----------------------
5011 In the reset configuration, U-Boot starts at the reset entry point
5012 (on most PowerPC systems at address 0x00000100). Because of the reset
5013 configuration for CS0# this is a mirror of the onboard Flash memory.
5014 To be able to re-map memory U-Boot then jumps to its link address.
5015 To be able to implement the initialization code in C, a (small!)
5016 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5017 which provide such a feature like MPC8xx or MPC8260), or in a locked
5018 part of the data cache. After that, U-Boot initializes the CPU core,
5019 the caches and the SIU.
5021 Next, all (potentially) available memory banks are mapped using a
5022 preliminary mapping. For example, we put them on 512 MB boundaries
5023 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5024 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5025 programmed for SDRAM access. Using the temporary configuration, a
5026 simple memory test is run that determines the size of the SDRAM
5029 When there is more than one SDRAM bank, and the banks are of
5030 different size, the largest is mapped first. For equal size, the first
5031 bank (CS2#) is mapped first. The first mapping is always for address
5032 0x00000000, with any additional banks following immediately to create
5033 contiguous memory starting from 0.
5035 Then, the monitor installs itself at the upper end of the SDRAM area
5036 and allocates memory for use by malloc() and for the global Board
5037 Info data; also, the exception vector code is copied to the low RAM
5038 pages, and the final stack is set up.
5040 Only after this relocation will you have a "normal" C environment;
5041 until that you are restricted in several ways, mostly because you are
5042 running from ROM, and because the code will have to be relocated to a
5046 U-Boot Porting Guide:
5047 ----------------------
5049 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5053 int main(int argc, char *argv[])
5055 sighandler_t no_more_time;
5057 signal(SIGALRM, no_more_time);
5058 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5060 if (available_money > available_manpower) {
5061 Pay consultant to port U-Boot;
5065 Download latest U-Boot source;
5067 Subscribe to u-boot mailing list;
5070 email("Hi, I am new to U-Boot, how do I get started?");
5073 Read the README file in the top level directory;
5074 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5075 Read applicable doc/*.README;
5076 Read the source, Luke;
5077 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5080 if (available_money > toLocalCurrency ($2500))
5083 Add a lot of aggravation and time;
5085 if (a similar board exists) { /* hopefully... */
5086 cp -a board/<similar> board/<myboard>
5087 cp include/configs/<similar>.h include/configs/<myboard>.h
5089 Create your own board support subdirectory;
5090 Create your own board include/configs/<myboard>.h file;
5092 Edit new board/<myboard> files
5093 Edit new include/configs/<myboard>.h
5098 Add / modify source code;
5102 email("Hi, I am having problems...");
5104 Send patch file to the U-Boot email list;
5105 if (reasonable critiques)
5106 Incorporate improvements from email list code review;
5108 Defend code as written;
5114 void no_more_time (int sig)
5123 All contributions to U-Boot should conform to the Linux kernel
5124 coding style; see the file "Documentation/CodingStyle" and the script
5125 "scripts/Lindent" in your Linux kernel source directory.
5127 Source files originating from a different project (for example the
5128 MTD subsystem) are generally exempt from these guidelines and are not
5129 reformated to ease subsequent migration to newer versions of those
5132 Please note that U-Boot is implemented in C (and to some small parts in
5133 Assembler); no C++ is used, so please do not use C++ style comments (//)
5136 Please also stick to the following formatting rules:
5137 - remove any trailing white space
5138 - use TAB characters for indentation and vertical alignment, not spaces
5139 - make sure NOT to use DOS '\r\n' line feeds
5140 - do not add more than 2 consecutive empty lines to source files
5141 - do not add trailing empty lines to source files
5143 Submissions which do not conform to the standards may be returned
5144 with a request to reformat the changes.
5150 Since the number of patches for U-Boot is growing, we need to
5151 establish some rules. Submissions which do not conform to these rules
5152 may be rejected, even when they contain important and valuable stuff.
5154 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5156 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5157 see http://lists.denx.de/mailman/listinfo/u-boot
5159 When you send a patch, please include the following information with
5162 * For bug fixes: a description of the bug and how your patch fixes
5163 this bug. Please try to include a way of demonstrating that the
5164 patch actually fixes something.
5166 * For new features: a description of the feature and your
5169 * A CHANGELOG entry as plaintext (separate from the patch)
5171 * For major contributions, your entry to the CREDITS file
5173 * When you add support for a new board, don't forget to add this
5174 board to the MAINTAINERS file, too.
5176 * If your patch adds new configuration options, don't forget to
5177 document these in the README file.
5179 * The patch itself. If you are using git (which is *strongly*
5180 recommended) you can easily generate the patch using the
5181 "git format-patch". If you then use "git send-email" to send it to
5182 the U-Boot mailing list, you will avoid most of the common problems
5183 with some other mail clients.
5185 If you cannot use git, use "diff -purN OLD NEW". If your version of
5186 diff does not support these options, then get the latest version of
5189 The current directory when running this command shall be the parent
5190 directory of the U-Boot source tree (i. e. please make sure that
5191 your patch includes sufficient directory information for the
5194 We prefer patches as plain text. MIME attachments are discouraged,
5195 and compressed attachments must not be used.
5197 * If one logical set of modifications affects or creates several
5198 files, all these changes shall be submitted in a SINGLE patch file.
5200 * Changesets that contain different, unrelated modifications shall be
5201 submitted as SEPARATE patches, one patch per changeset.
5206 * Before sending the patch, run the MAKEALL script on your patched
5207 source tree and make sure that no errors or warnings are reported
5208 for any of the boards.
5210 * Keep your modifications to the necessary minimum: A patch
5211 containing several unrelated changes or arbitrary reformats will be
5212 returned with a request to re-formatting / split it.
5214 * If you modify existing code, make sure that your new code does not
5215 add to the memory footprint of the code ;-) Small is beautiful!
5216 When adding new features, these should compile conditionally only
5217 (using #ifdef), and the resulting code with the new feature
5218 disabled must not need more memory than the old code without your
5221 * Remember that there is a size limit of 100 kB per message on the
5222 u-boot mailing list. Bigger patches will be moderated. If they are
5223 reasonable and not too big, they will be acknowledged. But patches
5224 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob