2 # (C) Copyright 2000 - 2012
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /x86 Files generic to x86 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /mips32 Files specific to MIPS32 CPUs
184 /xburst Files specific to Ingenic XBurst CPUs
185 /lib Architecture specific library files
186 /nds32 Files generic to NDS32 architecture
187 /cpu CPU specific files
188 /n1213 Files specific to Andes Technology N1213 CPUs
189 /lib Architecture specific library files
190 /nios2 Files generic to Altera NIOS2 architecture
191 /cpu CPU specific files
192 /lib Architecture specific library files
193 /powerpc Files generic to PowerPC architecture
194 /cpu CPU specific files
195 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
196 /mpc5xx Files specific to Freescale MPC5xx CPUs
197 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
198 /mpc8xx Files specific to Freescale MPC8xx CPUs
199 /mpc8220 Files specific to Freescale MPC8220 CPUs
200 /mpc824x Files specific to Freescale MPC824x CPUs
201 /mpc8260 Files specific to Freescale MPC8260 CPUs
202 /mpc85xx Files specific to Freescale MPC85xx CPUs
203 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
204 /lib Architecture specific library files
205 /sh Files generic to SH architecture
206 /cpu CPU specific files
207 /sh2 Files specific to sh2 CPUs
208 /sh3 Files specific to sh3 CPUs
209 /sh4 Files specific to sh4 CPUs
210 /lib Architecture specific library files
211 /sparc Files generic to SPARC architecture
212 /cpu CPU specific files
213 /leon2 Files specific to Gaisler LEON2 SPARC CPU
214 /leon3 Files specific to Gaisler LEON3 SPARC CPU
215 /lib Architecture specific library files
216 /api Machine/arch independent API for external apps
217 /board Board dependent files
218 /common Misc architecture independent functions
219 /disk Code for disk drive partition handling
220 /doc Documentation (don't expect too much)
221 /drivers Commonly used device drivers
222 /examples Example code for standalone applications, etc.
223 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
224 /include Header Files
225 /lib Files generic to all architectures
226 /libfdt Library files to support flattened device trees
227 /lzma Library files to support LZMA decompression
228 /lzo Library files to support LZO decompression
230 /post Power On Self Test
231 /rtc Real Time Clock drivers
232 /tools Tools to build S-Record or U-Boot images, etc.
234 Software Configuration:
235 =======================
237 Configuration is usually done using C preprocessor defines; the
238 rationale behind that is to avoid dead code whenever possible.
240 There are two classes of configuration variables:
242 * Configuration _OPTIONS_:
243 These are selectable by the user and have names beginning with
246 * Configuration _SETTINGS_:
247 These depend on the hardware etc. and should not be meddled with if
248 you don't know what you're doing; they have names beginning with
251 Later we will add a configuration tool - probably similar to or even
252 identical to what's used for the Linux kernel. Right now, we have to
253 do the configuration by hand, which means creating some symbolic
254 links and editing some configuration files. We use the TQM8xxL boards
258 Selection of Processor Architecture and Board Type:
259 ---------------------------------------------------
261 For all supported boards there are ready-to-use default
262 configurations available; just type "make <board_name>_config".
264 Example: For a TQM823L module type:
269 For the Cogent platform, you need to specify the CPU type as well;
270 e.g. "make cogent_mpc8xx_config". And also configure the cogent
271 directory according to the instructions in cogent/README.
274 Configuration Options:
275 ----------------------
277 Configuration depends on the combination of board and CPU type; all
278 such information is kept in a configuration file
279 "include/configs/<board_name>.h".
281 Example: For a TQM823L module, all configuration settings are in
282 "include/configs/TQM823L.h".
285 Many of the options are named exactly as the corresponding Linux
286 kernel configuration options. The intention is to make it easier to
287 build a config tool - later.
290 The following options need to be configured:
292 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
294 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
296 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
297 Define exactly one, e.g. CONFIG_ATSTK1002
299 - CPU Module Type: (if CONFIG_COGENT is defined)
300 Define exactly one of
302 --- FIXME --- not tested yet:
303 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
304 CONFIG_CMA287_23, CONFIG_CMA287_50
306 - Motherboard Type: (if CONFIG_COGENT is defined)
307 Define exactly one of
308 CONFIG_CMA101, CONFIG_CMA102
310 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
311 Define one or more of
314 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
315 Define one or more of
316 CONFIG_LCD_HEARTBEAT - update a character position on
317 the LCD display every second with
320 - Board flavour: (if CONFIG_MPC8260ADS is defined)
323 CONFIG_SYS_8260ADS - original MPC8260ADS
324 CONFIG_SYS_8266ADS - MPC8266ADS
325 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
326 CONFIG_SYS_8272ADS - MPC8272ADS
328 - Marvell Family Member
329 CONFIG_SYS_MVFS - define it if you want to enable
330 multiple fs option at one time
331 for marvell soc family
333 - MPC824X Family Member (if CONFIG_MPC824X is defined)
334 Define exactly one of
335 CONFIG_MPC8240, CONFIG_MPC8245
337 - 8xx CPU Options: (if using an MPC8xx CPU)
338 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
339 get_gclk_freq() cannot work
340 e.g. if there is no 32KHz
341 reference PIT/RTC clock
342 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
345 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
346 CONFIG_SYS_8xx_CPUCLK_MIN
347 CONFIG_SYS_8xx_CPUCLK_MAX
348 CONFIG_8xx_CPUCLK_DEFAULT
349 See doc/README.MPC866
351 CONFIG_SYS_MEASURE_CPUCLK
353 Define this to measure the actual CPU clock instead
354 of relying on the correctness of the configured
355 values. Mostly useful for board bringup to make sure
356 the PLL is locked at the intended frequency. Note
357 that this requires a (stable) reference clock (32 kHz
358 RTC clock or CONFIG_SYS_8XX_XIN)
360 CONFIG_SYS_DELAYED_ICACHE
362 Define this option if you want to enable the
363 ICache only when Code runs from RAM.
368 Specifies that the core is a 64-bit PowerPC implementation (implements
369 the "64" category of the Power ISA). This is necessary for ePAPR
370 compliance, among other possible reasons.
372 CONFIG_SYS_FSL_TBCLK_DIV
374 Defines the core time base clock divider ratio compared to the
375 system clock. On most PQ3 devices this is 8, on newer QorIQ
376 devices it can be 16 or 32. The ratio varies from SoC to Soc.
378 CONFIG_SYS_FSL_PCIE_COMPAT
380 Defines the string to utilize when trying to match PCIe device
381 tree nodes for the given platform.
383 CONFIG_SYS_PPC_E500_DEBUG_TLB
385 Enables a temporary TLB entry to be used during boot to work
386 around limitations in e500v1 and e500v2 external debugger
387 support. This reduces the portions of the boot code where
388 breakpoints and single stepping do not work. The value of this
389 symbol should be set to the TLB1 entry to be used for this
392 CONFIG_SYS_FSL_ERRATUM_A004510
394 Enables a workaround for erratum A004510. If set,
395 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
396 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
398 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
399 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
401 Defines one or two SoC revisions (low 8 bits of SVR)
402 for which the A004510 workaround should be applied.
404 The rest of SVR is either not relevant to the decision
405 of whether the erratum is present (e.g. p2040 versus
406 p2041) or is implied by the build target, which controls
407 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
409 See Freescale App Note 4493 for more information about
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 - Generic CPU options:
418 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
420 Defines the endianess of the CPU. Implementation of those
421 values is arch specific.
423 - Intel Monahans options:
424 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
426 Defines the Monahans run mode to oscillator
427 ratio. Valid values are 8, 16, 24, 31. The core
428 frequency is this value multiplied by 13 MHz.
430 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
432 Defines the Monahans turbo mode to oscillator
433 ratio. Valid values are 1 (default if undefined) and
434 2. The core frequency as calculated above is multiplied
438 CONFIG_SYS_INIT_SP_OFFSET
440 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
441 pointer. This is needed for the temporary stack before
444 CONFIG_SYS_MIPS_CACHE_MODE
446 Cache operation mode for the MIPS CPU.
447 See also arch/mips/include/asm/mipsregs.h.
449 CONF_CM_CACHABLE_NO_WA
452 CONF_CM_CACHABLE_NONCOHERENT
456 CONF_CM_CACHABLE_ACCELERATED
458 CONFIG_SYS_XWAY_EBU_BOOTCFG
460 Special option for Lantiq XWAY SoCs for booting from NOR flash.
461 See also arch/mips/cpu/mips32/start.S.
463 CONFIG_XWAY_SWAP_BYTES
465 Enable compilation of tools/xway-swap-bytes needed for Lantiq
466 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
467 be swapped if a flash programmer is used.
470 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
472 Select high exception vectors of the ARM core, e.g., do not
473 clear the V bit of the c1 register of CP15.
475 CONFIG_SYS_THUMB_BUILD
477 Use this flag to build U-Boot using the Thumb instruction
478 set for ARM architectures. Thumb instruction set provides
479 better code density. For ARM architectures that support
480 Thumb2 this flag will result in Thumb2 code generated by
483 - Linux Kernel Interface:
486 U-Boot stores all clock information in Hz
487 internally. For binary compatibility with older Linux
488 kernels (which expect the clocks passed in the
489 bd_info data to be in MHz) the environment variable
490 "clocks_in_mhz" can be defined so that U-Boot
491 converts clock data to MHZ before passing it to the
493 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
494 "clocks_in_mhz=1" is automatically included in the
497 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
499 When transferring memsize parameter to linux, some versions
500 expect it to be in bytes, others in MB.
501 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
505 New kernel versions are expecting firmware settings to be
506 passed using flattened device trees (based on open firmware
510 * New libfdt-based support
511 * Adds the "fdt" command
512 * The bootm command automatically updates the fdt
514 OF_CPU - The proper name of the cpus node (only required for
515 MPC512X and MPC5xxx based boards).
516 OF_SOC - The proper name of the soc node (only required for
517 MPC512X and MPC5xxx based boards).
518 OF_TBCLK - The timebase frequency.
519 OF_STDOUT_PATH - The path to the console device
521 boards with QUICC Engines require OF_QE to set UCC MAC
524 CONFIG_OF_BOARD_SETUP
526 Board code has addition modification that it wants to make
527 to the flat device tree before handing it off to the kernel
531 This define fills in the correct boot CPU in the boot
532 param header, the default value is zero if undefined.
536 U-Boot can detect if an IDE device is present or not.
537 If not, and this new config option is activated, U-Boot
538 removes the ATA node from the DTS before booting Linux,
539 so the Linux IDE driver does not probe the device and
540 crash. This is needed for buggy hardware (uc101) where
541 no pull down resistor is connected to the signal IDE5V_DD7.
543 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
545 This setting is mandatory for all boards that have only one
546 machine type and must be used to specify the machine type
547 number as it appears in the ARM machine registry
548 (see http://www.arm.linux.org.uk/developer/machines/).
549 Only boards that have multiple machine types supported
550 in a single configuration file and the machine type is
551 runtime discoverable, do not have to use this setting.
553 - vxWorks boot parameters:
555 bootvx constructs a valid bootline using the following
556 environments variables: bootfile, ipaddr, serverip, hostname.
557 It loads the vxWorks image pointed bootfile.
559 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
560 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
561 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
562 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
564 CONFIG_SYS_VXWORKS_ADD_PARAMS
566 Add it at the end of the bootline. E.g "u=username pw=secret"
568 Note: If a "bootargs" environment is defined, it will overwride
569 the defaults discussed just above.
571 - Cache Configuration:
572 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
573 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
574 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
576 - Cache Configuration for ARM:
577 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
579 CONFIG_SYS_PL310_BASE - Physical base address of PL310
580 controller register space
585 Define this if you want support for Amba PrimeCell PL010 UARTs.
589 Define this if you want support for Amba PrimeCell PL011 UARTs.
593 If you have Amba PrimeCell PL011 UARTs, set this variable to
594 the clock speed of the UARTs.
598 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
599 define this to a list of base addresses for each (supported)
600 port. See e.g. include/configs/versatile.h
602 CONFIG_PL011_SERIAL_RLCR
604 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
605 have separate receive and transmit line control registers. Set
606 this variable to initialize the extra register.
608 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
610 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
611 boot loader that has already initialized the UART. Define this
612 variable to flush the UART at init time.
616 Depending on board, define exactly one serial port
617 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
618 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
619 console by defining CONFIG_8xx_CONS_NONE
621 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
622 port routines must be defined elsewhere
623 (i.e. serial_init(), serial_getc(), ...)
626 Enables console device for a color framebuffer. Needs following
627 defines (cf. smiLynxEM, i8042)
628 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
630 VIDEO_HW_RECTFILL graphic chip supports
633 VIDEO_HW_BITBLT graphic chip supports
634 bit-blit (cf. smiLynxEM)
635 VIDEO_VISIBLE_COLS visible pixel columns
637 VIDEO_VISIBLE_ROWS visible pixel rows
638 VIDEO_PIXEL_SIZE bytes per pixel
639 VIDEO_DATA_FORMAT graphic data format
640 (0-5, cf. cfb_console.c)
641 VIDEO_FB_ADRS framebuffer address
642 VIDEO_KBD_INIT_FCT keyboard int fct
643 (i.e. i8042_kbd_init())
644 VIDEO_TSTC_FCT test char fct
646 VIDEO_GETC_FCT get char fct
648 CONFIG_CONSOLE_CURSOR cursor drawing on/off
649 (requires blink timer
651 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
652 CONFIG_CONSOLE_TIME display time/date info in
654 (requires CONFIG_CMD_DATE)
655 CONFIG_VIDEO_LOGO display Linux logo in
657 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
658 linux_logo.h for logo.
659 Requires CONFIG_VIDEO_LOGO
660 CONFIG_CONSOLE_EXTRA_INFO
661 additional board info beside
664 When CONFIG_CFB_CONSOLE is defined, video console is
665 default i/o. Serial console can be forced with
666 environment 'console=serial'.
668 When CONFIG_SILENT_CONSOLE is defined, all console
669 messages (by U-Boot and Linux!) can be silenced with
670 the "silent" environment variable. See
671 doc/README.silent for more information.
674 CONFIG_BAUDRATE - in bps
675 Select one of the baudrates listed in
676 CONFIG_SYS_BAUDRATE_TABLE, see below.
677 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
679 - Console Rx buffer length
680 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
681 the maximum receive buffer length for the SMC.
682 This option is actual only for 82xx and 8xx possible.
683 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
684 must be defined, to setup the maximum idle timeout for
687 - Pre-Console Buffer:
688 Prior to the console being initialised (i.e. serial UART
689 initialised etc) all console output is silently discarded.
690 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
691 buffer any console messages prior to the console being
692 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
693 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
694 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
695 bytes are output before the console is initialised, the
696 earlier bytes are discarded.
698 'Sane' compilers will generate smaller code if
699 CONFIG_PRE_CON_BUF_SZ is a power of 2
701 - Safe printf() functions
702 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
703 the printf() functions. These are defined in
704 include/vsprintf.h and include snprintf(), vsnprintf() and
705 so on. Code size increase is approximately 300-500 bytes.
706 If this option is not given then these functions will
707 silently discard their buffer size argument - this means
708 you are not getting any overflow checking in this case.
710 - Boot Delay: CONFIG_BOOTDELAY - in seconds
711 Delay before automatically booting the default image;
712 set to -1 to disable autoboot.
713 set to -2 to autoboot with no delay and not check for abort
714 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
716 See doc/README.autoboot for these options that
717 work with CONFIG_BOOTDELAY. None are required.
718 CONFIG_BOOT_RETRY_TIME
719 CONFIG_BOOT_RETRY_MIN
720 CONFIG_AUTOBOOT_KEYED
721 CONFIG_AUTOBOOT_PROMPT
722 CONFIG_AUTOBOOT_DELAY_STR
723 CONFIG_AUTOBOOT_STOP_STR
724 CONFIG_AUTOBOOT_DELAY_STR2
725 CONFIG_AUTOBOOT_STOP_STR2
726 CONFIG_ZERO_BOOTDELAY_CHECK
727 CONFIG_RESET_TO_RETRY
731 Only needed when CONFIG_BOOTDELAY is enabled;
732 define a command string that is automatically executed
733 when no character is read on the console interface
734 within "Boot Delay" after reset.
737 This can be used to pass arguments to the bootm
738 command. The value of CONFIG_BOOTARGS goes into the
739 environment value "bootargs".
741 CONFIG_RAMBOOT and CONFIG_NFSBOOT
742 The value of these goes into the environment as
743 "ramboot" and "nfsboot" respectively, and can be used
744 as a convenience, when switching between booting from
750 When this option is #defined, the existence of the
751 environment variable "preboot" will be checked
752 immediately before starting the CONFIG_BOOTDELAY
753 countdown and/or running the auto-boot command resp.
754 entering interactive mode.
756 This feature is especially useful when "preboot" is
757 automatically generated or modified. For an example
758 see the LWMON board specific code: here "preboot" is
759 modified when the user holds down a certain
760 combination of keys on the (special) keyboard when
763 - Serial Download Echo Mode:
765 If defined to 1, all characters received during a
766 serial download (using the "loads" command) are
767 echoed back. This might be needed by some terminal
768 emulations (like "cu"), but may as well just take
769 time on others. This setting #define's the initial
770 value of the "loads_echo" environment variable.
772 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
774 Select one of the baudrates listed in
775 CONFIG_SYS_BAUDRATE_TABLE, see below.
778 Monitor commands can be included or excluded
779 from the build by using the #include files
780 <config_cmd_all.h> and #undef'ing unwanted
781 commands, or using <config_cmd_default.h>
782 and augmenting with additional #define's
785 The default command configuration includes all commands
786 except those marked below with a "*".
788 CONFIG_CMD_ASKENV * ask for env variable
789 CONFIG_CMD_BDI bdinfo
790 CONFIG_CMD_BEDBUG * Include BedBug Debugger
791 CONFIG_CMD_BMP * BMP support
792 CONFIG_CMD_BSP * Board specific commands
793 CONFIG_CMD_BOOTD bootd
794 CONFIG_CMD_CACHE * icache, dcache
795 CONFIG_CMD_CONSOLE coninfo
796 CONFIG_CMD_CRC32 * crc32
797 CONFIG_CMD_DATE * support for RTC, date/time...
798 CONFIG_CMD_DHCP * DHCP support
799 CONFIG_CMD_DIAG * Diagnostics
800 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
801 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
802 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
803 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
804 CONFIG_CMD_DTT * Digital Therm and Thermostat
805 CONFIG_CMD_ECHO echo arguments
806 CONFIG_CMD_EDITENV edit env variable
807 CONFIG_CMD_EEPROM * EEPROM read/write support
808 CONFIG_CMD_ELF * bootelf, bootvx
809 CONFIG_CMD_EXPORTENV * export the environment
810 CONFIG_CMD_EXT2 * ext2 command support
811 CONFIG_CMD_EXT4 * ext4 command support
812 CONFIG_CMD_SAVEENV saveenv
813 CONFIG_CMD_FDC * Floppy Disk Support
814 CONFIG_CMD_FAT * FAT command support
815 CONFIG_CMD_FDOS * Dos diskette Support
816 CONFIG_CMD_FLASH flinfo, erase, protect
817 CONFIG_CMD_FPGA FPGA device initialization support
818 CONFIG_CMD_GO * the 'go' command (exec code)
819 CONFIG_CMD_GREPENV * search environment
820 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
821 CONFIG_CMD_I2C * I2C serial bus support
822 CONFIG_CMD_IDE * IDE harddisk support
823 CONFIG_CMD_IMI iminfo
824 CONFIG_CMD_IMLS List all found images
825 CONFIG_CMD_IMMAP * IMMR dump support
826 CONFIG_CMD_IMPORTENV * import an environment
827 CONFIG_CMD_INI * import data from an ini file into the env
828 CONFIG_CMD_IRQ * irqinfo
829 CONFIG_CMD_ITEST Integer/string test of 2 values
830 CONFIG_CMD_JFFS2 * JFFS2 Support
831 CONFIG_CMD_KGDB * kgdb
832 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
833 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
835 CONFIG_CMD_LOADB loadb
836 CONFIG_CMD_LOADS loads
837 CONFIG_CMD_MD5SUM print md5 message digest
838 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
839 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
841 CONFIG_CMD_MISC Misc functions like sleep etc
842 CONFIG_CMD_MMC * MMC memory mapped support
843 CONFIG_CMD_MII * MII utility commands
844 CONFIG_CMD_MTDPARTS * MTD partition support
845 CONFIG_CMD_NAND * NAND support
846 CONFIG_CMD_NET bootp, tftpboot, rarpboot
847 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
848 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
849 CONFIG_CMD_PCI * pciinfo
850 CONFIG_CMD_PCMCIA * PCMCIA support
851 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
853 CONFIG_CMD_PORTIO * Port I/O
854 CONFIG_CMD_REGINFO * Register dump
855 CONFIG_CMD_RUN run command in env variable
856 CONFIG_CMD_SAVES * save S record dump
857 CONFIG_CMD_SCSI * SCSI Support
858 CONFIG_CMD_SDRAM * print SDRAM configuration information
859 (requires CONFIG_CMD_I2C)
860 CONFIG_CMD_SETGETDCR Support for DCR Register access
862 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
863 CONFIG_CMD_SHA1SUM print sha1 memory digest
864 (requires CONFIG_CMD_MEMORY)
865 CONFIG_CMD_SOURCE "source" command Support
866 CONFIG_CMD_SPI * SPI serial bus support
867 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
868 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
869 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
870 CONFIG_CMD_TIMER * access to the system tick timer
871 CONFIG_CMD_USB * USB support
872 CONFIG_CMD_CDP * Cisco Discover Protocol support
873 CONFIG_CMD_MFSL * Microblaze FSL support
876 EXAMPLE: If you want all functions except of network
877 support you can write:
879 #include "config_cmd_all.h"
880 #undef CONFIG_CMD_NET
883 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
885 Note: Don't enable the "icache" and "dcache" commands
886 (configuration option CONFIG_CMD_CACHE) unless you know
887 what you (and your U-Boot users) are doing. Data
888 cache cannot be enabled on systems like the 8xx or
889 8260 (where accesses to the IMMR region must be
890 uncached), and it cannot be disabled on all other
891 systems where we (mis-) use the data cache to hold an
892 initial stack and some data.
895 XXX - this list needs to get updated!
899 If this variable is defined, U-Boot will use a device tree
900 to configure its devices, instead of relying on statically
901 compiled #defines in the board file. This option is
902 experimental and only available on a few boards. The device
903 tree is available in the global data as gd->fdt_blob.
905 U-Boot needs to get its device tree from somewhere. This can
906 be done using one of the two options below:
909 If this variable is defined, U-Boot will embed a device tree
910 binary in its image. This device tree file should be in the
911 board directory and called <soc>-<board>.dts. The binary file
912 is then picked up in board_init_f() and made available through
913 the global data structure as gd->blob.
916 If this variable is defined, U-Boot will build a device tree
917 binary. It will be called u-boot.dtb. Architecture-specific
918 code will locate it at run-time. Generally this works by:
920 cat u-boot.bin u-boot.dtb >image.bin
922 and in fact, U-Boot does this for you, creating a file called
923 u-boot-dtb.bin which is useful in the common case. You can
924 still use the individual files if you need something more
929 If this variable is defined, it enables watchdog
930 support for the SoC. There must be support in the SoC
931 specific code for a watchdog. For the 8xx and 8260
932 CPUs, the SIU Watchdog feature is enabled in the SYPCR
933 register. When supported for a specific SoC is
934 available, then no further board specific code should
938 When using a watchdog circuitry external to the used
939 SoC, then define this variable and provide board
940 specific code for the "hw_watchdog_reset" function.
943 CONFIG_VERSION_VARIABLE
944 If this variable is defined, an environment variable
945 named "ver" is created by U-Boot showing the U-Boot
946 version as printed by the "version" command.
947 Any change to this variable will be reverted at the
952 When CONFIG_CMD_DATE is selected, the type of the RTC
953 has to be selected, too. Define exactly one of the
956 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
957 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
958 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
959 CONFIG_RTC_MC146818 - use MC146818 RTC
960 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
961 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
962 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
963 CONFIG_RTC_DS164x - use Dallas DS164x RTC
964 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
965 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
966 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
967 CONFIG_SYS_RV3029_TCR - enable trickle charger on
970 Note that if the RTC uses I2C, then the I2C interface
971 must also be configured. See I2C Support, below.
974 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
975 CONFIG_PCA953X_INFO - enable pca953x info command
977 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
978 chip-ngpio pairs that tell the PCA953X driver the number of
979 pins supported by a particular chip.
981 Note that if the GPIO device uses I2C, then the I2C interface
982 must also be configured. See I2C Support, below.
986 When CONFIG_TIMESTAMP is selected, the timestamp
987 (date and time) of an image is printed by image
988 commands like bootm or iminfo. This option is
989 automatically enabled when you select CONFIG_CMD_DATE .
991 - Partition Labels (disklabels) Supported:
992 Zero or more of the following:
993 CONFIG_MAC_PARTITION Apple's MacOS partition table.
994 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
995 Intel architecture, USB sticks, etc.
996 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
997 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
998 bootloader. Note 2TB partition limit; see
1000 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1002 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1003 CONFIG_CMD_SCSI) you must configure support for at
1004 least one non-MTD partition type as well.
1007 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1008 board configurations files but used nowhere!
1010 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1011 be performed by calling the function
1012 ide_set_reset(int reset)
1013 which has to be defined in a board specific file
1018 Set this to enable ATAPI support.
1023 Set this to enable support for disks larger than 137GB
1024 Also look at CONFIG_SYS_64BIT_LBA.
1025 Whithout these , LBA48 support uses 32bit variables and will 'only'
1026 support disks up to 2.1TB.
1028 CONFIG_SYS_64BIT_LBA:
1029 When enabled, makes the IDE subsystem use 64bit sector addresses.
1033 At the moment only there is only support for the
1034 SYM53C8XX SCSI controller; define
1035 CONFIG_SCSI_SYM53C8XX to enable it.
1037 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1038 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1039 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1040 maximum numbers of LUNs, SCSI ID's and target
1042 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1044 - NETWORK Support (PCI):
1046 Support for Intel 8254x/8257x gigabit chips.
1049 Utility code for direct access to the SPI bus on Intel 8257x.
1050 This does not do anything useful unless you set at least one
1051 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1053 CONFIG_E1000_SPI_GENERIC
1054 Allow generic access to the SPI bus on the Intel 8257x, for
1055 example with the "sspi" command.
1058 Management command for E1000 devices. When used on devices
1059 with SPI support you can reprogram the EEPROM from U-Boot.
1061 CONFIG_E1000_FALLBACK_MAC
1062 default MAC for empty EEPROM after production.
1065 Support for Intel 82557/82559/82559ER chips.
1066 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1067 write routine for first time initialisation.
1070 Support for Digital 2114x chips.
1071 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1072 modem chip initialisation (KS8761/QS6611).
1075 Support for National dp83815 chips.
1078 Support for National dp8382[01] gigabit chips.
1080 - NETWORK Support (other):
1082 CONFIG_DRIVER_AT91EMAC
1083 Support for AT91RM9200 EMAC.
1086 Define this to use reduced MII inteface
1088 CONFIG_DRIVER_AT91EMAC_QUIET
1089 If this defined, the driver is quiet.
1090 The driver doen't show link status messages.
1092 CONFIG_CALXEDA_XGMAC
1093 Support for the Calxeda XGMAC device
1096 Support for SMSC's LAN91C96 chips.
1098 CONFIG_LAN91C96_BASE
1099 Define this to hold the physical address
1100 of the LAN91C96's I/O space
1102 CONFIG_LAN91C96_USE_32_BIT
1103 Define this to enable 32 bit addressing
1106 Support for SMSC's LAN91C111 chip
1108 CONFIG_SMC91111_BASE
1109 Define this to hold the physical address
1110 of the device (I/O space)
1112 CONFIG_SMC_USE_32_BIT
1113 Define this if data bus is 32 bits
1115 CONFIG_SMC_USE_IOFUNCS
1116 Define this to use i/o functions instead of macros
1117 (some hardware wont work with macros)
1119 CONFIG_DRIVER_TI_EMAC
1120 Support for davinci emac
1122 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1123 Define this if you have more then 3 PHYs.
1126 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1128 CONFIG_FTGMAC100_EGIGA
1129 Define this to use GE link update with gigabit PHY.
1130 Define this if FTGMAC100 is connected to gigabit PHY.
1131 If your system has 10/100 PHY only, it might not occur
1132 wrong behavior. Because PHY usually return timeout or
1133 useless data when polling gigabit status and gigabit
1134 control registers. This behavior won't affect the
1135 correctnessof 10/100 link speed update.
1138 Support for SMSC's LAN911x and LAN921x chips
1141 Define this to hold the physical address
1142 of the device (I/O space)
1144 CONFIG_SMC911X_32_BIT
1145 Define this if data bus is 32 bits
1147 CONFIG_SMC911X_16_BIT
1148 Define this if data bus is 16 bits. If your processor
1149 automatically converts one 32 bit word to two 16 bit
1150 words you may also try CONFIG_SMC911X_32_BIT.
1153 Support for Renesas on-chip Ethernet controller
1155 CONFIG_SH_ETHER_USE_PORT
1156 Define the number of ports to be used
1158 CONFIG_SH_ETHER_PHY_ADDR
1159 Define the ETH PHY's address
1161 CONFIG_SH_ETHER_CACHE_WRITEBACK
1162 If this option is set, the driver enables cache flush.
1165 CONFIG_GENERIC_LPC_TPM
1166 Support for generic parallel port TPM devices. Only one device
1167 per system is supported at this time.
1169 CONFIG_TPM_TIS_BASE_ADDRESS
1170 Base address where the generic TPM device is mapped
1171 to. Contemporary x86 systems usually map it at
1175 At the moment only the UHCI host controller is
1176 supported (PIP405, MIP405, MPC5200); define
1177 CONFIG_USB_UHCI to enable it.
1178 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1179 and define CONFIG_USB_STORAGE to enable the USB
1182 Supported are USB Keyboards and USB Floppy drives
1184 MPC5200 USB requires additional defines:
1186 for 528 MHz Clock: 0x0001bbbb
1190 for differential drivers: 0x00001000
1191 for single ended drivers: 0x00005000
1192 for differential drivers on PSC3: 0x00000100
1193 for single ended drivers on PSC3: 0x00004100
1194 CONFIG_SYS_USB_EVENT_POLL
1195 May be defined to allow interrupt polling
1196 instead of using asynchronous interrupts
1198 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1199 txfilltuning field in the EHCI controller on reset.
1202 Define the below if you wish to use the USB console.
1203 Once firmware is rebuilt from a serial console issue the
1204 command "setenv stdin usbtty; setenv stdout usbtty" and
1205 attach your USB cable. The Unix command "dmesg" should print
1206 it has found a new device. The environment variable usbtty
1207 can be set to gserial or cdc_acm to enable your device to
1208 appear to a USB host as a Linux gserial device or a
1209 Common Device Class Abstract Control Model serial device.
1210 If you select usbtty = gserial you should be able to enumerate
1212 # modprobe usbserial vendor=0xVendorID product=0xProductID
1213 else if using cdc_acm, simply setting the environment
1214 variable usbtty to be cdc_acm should suffice. The following
1215 might be defined in YourBoardName.h
1218 Define this to build a UDC device
1221 Define this to have a tty type of device available to
1222 talk to the UDC device
1225 Define this to enable the high speed support for usb
1226 device and usbtty. If this feature is enabled, a routine
1227 int is_usbd_high_speed(void)
1228 also needs to be defined by the driver to dynamically poll
1229 whether the enumeration has succeded at high speed or full
1232 CONFIG_SYS_CONSOLE_IS_IN_ENV
1233 Define this if you want stdin, stdout &/or stderr to
1237 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1238 Derive USB clock from external clock "blah"
1239 - CONFIG_SYS_USB_EXTC_CLK 0x02
1241 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1242 Derive USB clock from brgclk
1243 - CONFIG_SYS_USB_BRG_CLK 0x04
1245 If you have a USB-IF assigned VendorID then you may wish to
1246 define your own vendor specific values either in BoardName.h
1247 or directly in usbd_vendor_info.h. If you don't define
1248 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1249 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1250 should pretend to be a Linux device to it's target host.
1252 CONFIG_USBD_MANUFACTURER
1253 Define this string as the name of your company for
1254 - CONFIG_USBD_MANUFACTURER "my company"
1256 CONFIG_USBD_PRODUCT_NAME
1257 Define this string as the name of your product
1258 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1260 CONFIG_USBD_VENDORID
1261 Define this as your assigned Vendor ID from the USB
1262 Implementors Forum. This *must* be a genuine Vendor ID
1263 to avoid polluting the USB namespace.
1264 - CONFIG_USBD_VENDORID 0xFFFF
1266 CONFIG_USBD_PRODUCTID
1267 Define this as the unique Product ID
1269 - CONFIG_USBD_PRODUCTID 0xFFFF
1271 - ULPI Layer Support:
1272 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1273 the generic ULPI layer. The generic layer accesses the ULPI PHY
1274 via the platform viewport, so you need both the genric layer and
1275 the viewport enabled. Currently only Chipidea/ARC based
1276 viewport is supported.
1277 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1278 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1279 If your ULPI phy needs a different reference clock than the
1280 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1281 the appropriate value in Hz.
1284 The MMC controller on the Intel PXA is supported. To
1285 enable this define CONFIG_MMC. The MMC can be
1286 accessed from the boot prompt by mapping the device
1287 to physical memory similar to flash. Command line is
1288 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1289 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1292 Support for Renesas on-chip MMCIF controller
1294 CONFIG_SH_MMCIF_ADDR
1295 Define the base address of MMCIF registers
1298 Define the clock frequency for MMCIF
1300 - Journaling Flash filesystem support:
1301 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1302 CONFIG_JFFS2_NAND_DEV
1303 Define these for a default partition on a NAND device
1305 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1306 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1307 Define these for a default partition on a NOR device
1309 CONFIG_SYS_JFFS_CUSTOM_PART
1310 Define this to create an own partition. You have to provide a
1311 function struct part_info* jffs2_part_info(int part_num)
1313 If you define only one JFFS2 partition you may also want to
1314 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1315 to disable the command chpart. This is the default when you
1316 have not defined a custom partition
1318 - FAT(File Allocation Table) filesystem write function support:
1321 Define this to enable support for saving memory data as a
1322 file in FAT formatted partition.
1324 This will also enable the command "fatwrite" enabling the
1325 user to write files to FAT.
1327 CBFS (Coreboot Filesystem) support
1330 Define this to enable support for reading from a Coreboot
1331 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1337 Define this to enable standard (PC-Style) keyboard
1341 Standard PC keyboard driver with US (is default) and
1342 GERMAN key layout (switch via environment 'keymap=de') support.
1343 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1344 for cfb_console. Supports cursor blinking.
1349 Define this to enable video support (for output to
1352 CONFIG_VIDEO_CT69000
1354 Enable Chips & Technologies 69000 Video chip
1356 CONFIG_VIDEO_SMI_LYNXEM
1357 Enable Silicon Motion SMI 712/710/810 Video chip. The
1358 video output is selected via environment 'videoout'
1359 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1362 For the CT69000 and SMI_LYNXEM drivers, videomode is
1363 selected via environment 'videomode'. Two different ways
1365 - "videomode=num" 'num' is a standard LiLo mode numbers.
1366 Following standard modes are supported (* is default):
1368 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1369 -------------+---------------------------------------------
1370 8 bits | 0x301* 0x303 0x305 0x161 0x307
1371 15 bits | 0x310 0x313 0x316 0x162 0x319
1372 16 bits | 0x311 0x314 0x317 0x163 0x31A
1373 24 bits | 0x312 0x315 0x318 ? 0x31B
1374 -------------+---------------------------------------------
1375 (i.e. setenv videomode 317; saveenv; reset;)
1377 - "videomode=bootargs" all the video parameters are parsed
1378 from the bootargs. (See drivers/video/videomodes.c)
1381 CONFIG_VIDEO_SED13806
1382 Enable Epson SED13806 driver. This driver supports 8bpp
1383 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1384 or CONFIG_VIDEO_SED13806_16BPP
1387 Enable the Freescale DIU video driver. Reference boards for
1388 SOCs that have a DIU should define this macro to enable DIU
1389 support, and should also define these other macros:
1395 CONFIG_VIDEO_SW_CURSOR
1396 CONFIG_VGA_AS_SINGLE_DEVICE
1398 CONFIG_VIDEO_BMP_LOGO
1400 The DIU driver will look for the 'video-mode' environment
1401 variable, and if defined, enable the DIU as a console during
1402 boot. See the documentation file README.video for a
1403 description of this variable.
1408 Define this to enable a custom keyboard support.
1409 This simply calls drv_keyboard_init() which must be
1410 defined in your board-specific files.
1411 The only board using this so far is RBC823.
1413 - LCD Support: CONFIG_LCD
1415 Define this to enable LCD support (for output to LCD
1416 display); also select one of the supported displays
1417 by defining one of these:
1421 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1423 CONFIG_NEC_NL6448AC33:
1425 NEC NL6448AC33-18. Active, color, single scan.
1427 CONFIG_NEC_NL6448BC20
1429 NEC NL6448BC20-08. 6.5", 640x480.
1430 Active, color, single scan.
1432 CONFIG_NEC_NL6448BC33_54
1434 NEC NL6448BC33-54. 10.4", 640x480.
1435 Active, color, single scan.
1439 Sharp 320x240. Active, color, single scan.
1440 It isn't 16x9, and I am not sure what it is.
1442 CONFIG_SHARP_LQ64D341
1444 Sharp LQ64D341 display, 640x480.
1445 Active, color, single scan.
1449 HLD1045 display, 640x480.
1450 Active, color, single scan.
1454 Optrex CBL50840-2 NF-FW 99 22 M5
1456 Hitachi LMG6912RPFC-00T
1460 320x240. Black & white.
1462 Normally display is black on white background; define
1463 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1465 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1467 If this option is set, the environment is checked for
1468 a variable "splashimage". If found, the usual display
1469 of logo, copyright and system information on the LCD
1470 is suppressed and the BMP image at the address
1471 specified in "splashimage" is loaded instead. The
1472 console is redirected to the "nulldev", too. This
1473 allows for a "silent" boot where a splash screen is
1474 loaded very quickly after power-on.
1476 CONFIG_SPLASH_SCREEN_ALIGN
1478 If this option is set the splash image can be freely positioned
1479 on the screen. Environment variable "splashpos" specifies the
1480 position as "x,y". If a positive number is given it is used as
1481 number of pixel from left/top. If a negative number is given it
1482 is used as number of pixel from right/bottom. You can also
1483 specify 'm' for centering the image.
1486 setenv splashpos m,m
1487 => image at center of screen
1489 setenv splashpos 30,20
1490 => image at x = 30 and y = 20
1492 setenv splashpos -10,m
1493 => vertically centered image
1494 at x = dspWidth - bmpWidth - 9
1496 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1498 If this option is set, additionally to standard BMP
1499 images, gzipped BMP images can be displayed via the
1500 splashscreen support or the bmp command.
1502 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1504 If this option is set, 8-bit RLE compressed BMP images
1505 can be displayed via the splashscreen support or the
1508 - Do compresssing for memory range:
1511 If this option is set, it would use zlib deflate method
1512 to compress the specified memory at its best effort.
1514 - Compression support:
1517 If this option is set, support for bzip2 compressed
1518 images is included. If not, only uncompressed and gzip
1519 compressed images are supported.
1521 NOTE: the bzip2 algorithm requires a lot of RAM, so
1522 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1527 If this option is set, support for lzma compressed
1530 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1531 requires an amount of dynamic memory that is given by the
1534 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1536 Where lc and lp stand for, respectively, Literal context bits
1537 and Literal pos bits.
1539 This value is upper-bounded by 14MB in the worst case. Anyway,
1540 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1541 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1542 a very small buffer.
1544 Use the lzmainfo tool to determinate the lc and lp values and
1545 then calculate the amount of needed dynamic memory (ensuring
1546 the appropriate CONFIG_SYS_MALLOC_LEN value).
1551 The address of PHY on MII bus.
1553 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1555 The clock frequency of the MII bus
1559 If this option is set, support for speed/duplex
1560 detection of gigabit PHY is included.
1562 CONFIG_PHY_RESET_DELAY
1564 Some PHY like Intel LXT971A need extra delay after
1565 reset before any MII register access is possible.
1566 For such PHY, set this option to the usec delay
1567 required. (minimum 300usec for LXT971A)
1569 CONFIG_PHY_CMD_DELAY (ppc4xx)
1571 Some PHY like Intel LXT971A need extra delay after
1572 command issued before MII status register can be read
1582 Define a default value for Ethernet address to use
1583 for the respective Ethernet interface, in case this
1584 is not determined automatically.
1589 Define a default value for the IP address to use for
1590 the default Ethernet interface, in case this is not
1591 determined through e.g. bootp.
1592 (Environment variable "ipaddr")
1594 - Server IP address:
1597 Defines a default value for the IP address of a TFTP
1598 server to contact when using the "tftboot" command.
1599 (Environment variable "serverip")
1601 CONFIG_KEEP_SERVERADDR
1603 Keeps the server's MAC address, in the env 'serveraddr'
1604 for passing to bootargs (like Linux's netconsole option)
1606 - Gateway IP address:
1609 Defines a default value for the IP address of the
1610 default router where packets to other networks are
1612 (Environment variable "gatewayip")
1617 Defines a default value for the subnet mask (or
1618 routing prefix) which is used to determine if an IP
1619 address belongs to the local subnet or needs to be
1620 forwarded through a router.
1621 (Environment variable "netmask")
1623 - Multicast TFTP Mode:
1626 Defines whether you want to support multicast TFTP as per
1627 rfc-2090; for example to work with atftp. Lets lots of targets
1628 tftp down the same boot image concurrently. Note: the Ethernet
1629 driver in use must provide a function: mcast() to join/leave a
1632 - BOOTP Recovery Mode:
1633 CONFIG_BOOTP_RANDOM_DELAY
1635 If you have many targets in a network that try to
1636 boot using BOOTP, you may want to avoid that all
1637 systems send out BOOTP requests at precisely the same
1638 moment (which would happen for instance at recovery
1639 from a power failure, when all systems will try to
1640 boot, thus flooding the BOOTP server. Defining
1641 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1642 inserted before sending out BOOTP requests. The
1643 following delays are inserted then:
1645 1st BOOTP request: delay 0 ... 1 sec
1646 2nd BOOTP request: delay 0 ... 2 sec
1647 3rd BOOTP request: delay 0 ... 4 sec
1649 BOOTP requests: delay 0 ... 8 sec
1651 - DHCP Advanced Options:
1652 You can fine tune the DHCP functionality by defining
1653 CONFIG_BOOTP_* symbols:
1655 CONFIG_BOOTP_SUBNETMASK
1656 CONFIG_BOOTP_GATEWAY
1657 CONFIG_BOOTP_HOSTNAME
1658 CONFIG_BOOTP_NISDOMAIN
1659 CONFIG_BOOTP_BOOTPATH
1660 CONFIG_BOOTP_BOOTFILESIZE
1663 CONFIG_BOOTP_SEND_HOSTNAME
1664 CONFIG_BOOTP_NTPSERVER
1665 CONFIG_BOOTP_TIMEOFFSET
1666 CONFIG_BOOTP_VENDOREX
1667 CONFIG_BOOTP_MAY_FAIL
1669 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1670 environment variable, not the BOOTP server.
1672 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1673 after the configured retry count, the call will fail
1674 instead of starting over. This can be used to fail over
1675 to Link-local IP address configuration if the DHCP server
1678 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1679 serverip from a DHCP server, it is possible that more
1680 than one DNS serverip is offered to the client.
1681 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1682 serverip will be stored in the additional environment
1683 variable "dnsip2". The first DNS serverip is always
1684 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1687 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1688 to do a dynamic update of a DNS server. To do this, they
1689 need the hostname of the DHCP requester.
1690 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1691 of the "hostname" environment variable is passed as
1692 option 12 to the DHCP server.
1694 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1696 A 32bit value in microseconds for a delay between
1697 receiving a "DHCP Offer" and sending the "DHCP Request".
1698 This fixes a problem with certain DHCP servers that don't
1699 respond 100% of the time to a "DHCP request". E.g. On an
1700 AT91RM9200 processor running at 180MHz, this delay needed
1701 to be *at least* 15,000 usec before a Windows Server 2003
1702 DHCP server would reply 100% of the time. I recommend at
1703 least 50,000 usec to be safe. The alternative is to hope
1704 that one of the retries will be successful but note that
1705 the DHCP timeout and retry process takes a longer than
1708 - Link-local IP address negotiation:
1709 Negotiate with other link-local clients on the local network
1710 for an address that doesn't require explicit configuration.
1711 This is especially useful if a DHCP server cannot be guaranteed
1712 to exist in all environments that the device must operate.
1714 See doc/README.link-local for more information.
1717 CONFIG_CDP_DEVICE_ID
1719 The device id used in CDP trigger frames.
1721 CONFIG_CDP_DEVICE_ID_PREFIX
1723 A two character string which is prefixed to the MAC address
1728 A printf format string which contains the ascii name of
1729 the port. Normally is set to "eth%d" which sets
1730 eth0 for the first Ethernet, eth1 for the second etc.
1732 CONFIG_CDP_CAPABILITIES
1734 A 32bit integer which indicates the device capabilities;
1735 0x00000010 for a normal host which does not forwards.
1739 An ascii string containing the version of the software.
1743 An ascii string containing the name of the platform.
1747 A 32bit integer sent on the trigger.
1749 CONFIG_CDP_POWER_CONSUMPTION
1751 A 16bit integer containing the power consumption of the
1752 device in .1 of milliwatts.
1754 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1756 A byte containing the id of the VLAN.
1758 - Status LED: CONFIG_STATUS_LED
1760 Several configurations allow to display the current
1761 status using a LED. For instance, the LED will blink
1762 fast while running U-Boot code, stop blinking as
1763 soon as a reply to a BOOTP request was received, and
1764 start blinking slow once the Linux kernel is running
1765 (supported by a status LED driver in the Linux
1766 kernel). Defining CONFIG_STATUS_LED enables this
1769 - CAN Support: CONFIG_CAN_DRIVER
1771 Defining CONFIG_CAN_DRIVER enables CAN driver support
1772 on those systems that support this (optional)
1773 feature, like the TQM8xxL modules.
1775 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1777 These enable I2C serial bus commands. Defining either of
1778 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1779 include the appropriate I2C driver for the selected CPU.
1781 This will allow you to use i2c commands at the u-boot
1782 command line (as long as you set CONFIG_CMD_I2C in
1783 CONFIG_COMMANDS) and communicate with i2c based realtime
1784 clock chips. See common/cmd_i2c.c for a description of the
1785 command line interface.
1787 CONFIG_HARD_I2C selects a hardware I2C controller.
1789 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1790 bit-banging) driver instead of CPM or similar hardware
1793 There are several other quantities that must also be
1794 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1796 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1797 to be the frequency (in Hz) at which you wish your i2c bus
1798 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1799 the CPU's i2c node address).
1801 Now, the u-boot i2c code for the mpc8xx
1802 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1803 and so its address should therefore be cleared to 0 (See,
1804 eg, MPC823e User's Manual p.16-473). So, set
1805 CONFIG_SYS_I2C_SLAVE to 0.
1807 CONFIG_SYS_I2C_INIT_MPC5XXX
1809 When a board is reset during an i2c bus transfer
1810 chips might think that the current transfer is still
1811 in progress. Reset the slave devices by sending start
1812 commands until the slave device responds.
1814 That's all that's required for CONFIG_HARD_I2C.
1816 If you use the software i2c interface (CONFIG_SOFT_I2C)
1817 then the following macros need to be defined (examples are
1818 from include/configs/lwmon.h):
1822 (Optional). Any commands necessary to enable the I2C
1823 controller or configure ports.
1825 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1829 (Only for MPC8260 CPU). The I/O port to use (the code
1830 assumes both bits are on the same port). Valid values
1831 are 0..3 for ports A..D.
1835 The code necessary to make the I2C data line active
1836 (driven). If the data line is open collector, this
1839 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1843 The code necessary to make the I2C data line tri-stated
1844 (inactive). If the data line is open collector, this
1847 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1851 Code that returns TRUE if the I2C data line is high,
1854 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1858 If <bit> is TRUE, sets the I2C data line high. If it
1859 is FALSE, it clears it (low).
1861 eg: #define I2C_SDA(bit) \
1862 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1863 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1867 If <bit> is TRUE, sets the I2C clock line high. If it
1868 is FALSE, it clears it (low).
1870 eg: #define I2C_SCL(bit) \
1871 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1872 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1876 This delay is invoked four times per clock cycle so this
1877 controls the rate of data transfer. The data rate thus
1878 is 1 / (I2C_DELAY * 4). Often defined to be something
1881 #define I2C_DELAY udelay(2)
1883 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1885 If your arch supports the generic GPIO framework (asm/gpio.h),
1886 then you may alternatively define the two GPIOs that are to be
1887 used as SCL / SDA. Any of the previous I2C_xxx macros will
1888 have GPIO-based defaults assigned to them as appropriate.
1890 You should define these to the GPIO value as given directly to
1891 the generic GPIO functions.
1893 CONFIG_SYS_I2C_INIT_BOARD
1895 When a board is reset during an i2c bus transfer
1896 chips might think that the current transfer is still
1897 in progress. On some boards it is possible to access
1898 the i2c SCLK line directly, either by using the
1899 processor pin as a GPIO or by having a second pin
1900 connected to the bus. If this option is defined a
1901 custom i2c_init_board() routine in boards/xxx/board.c
1902 is run early in the boot sequence.
1904 CONFIG_SYS_I2C_BOARD_LATE_INIT
1906 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1907 defined a custom i2c_board_late_init() routine in
1908 boards/xxx/board.c is run AFTER the operations in i2c_init()
1909 is completed. This callpoint can be used to unreset i2c bus
1910 using CPU i2c controller register accesses for CPUs whose i2c
1911 controller provide such a method. It is called at the end of
1912 i2c_init() to allow i2c_init operations to setup the i2c bus
1913 controller on the CPU (e.g. setting bus speed & slave address).
1915 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1917 This option enables configuration of bi_iic_fast[] flags
1918 in u-boot bd_info structure based on u-boot environment
1919 variable "i2cfast". (see also i2cfast)
1921 CONFIG_I2C_MULTI_BUS
1923 This option allows the use of multiple I2C buses, each of which
1924 must have a controller. At any point in time, only one bus is
1925 active. To switch to a different bus, use the 'i2c dev' command.
1926 Note that bus numbering is zero-based.
1928 CONFIG_SYS_I2C_NOPROBES
1930 This option specifies a list of I2C devices that will be skipped
1931 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1932 is set, specify a list of bus-device pairs. Otherwise, specify
1933 a 1D array of device addresses
1936 #undef CONFIG_I2C_MULTI_BUS
1937 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1939 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1941 #define CONFIG_I2C_MULTI_BUS
1942 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1944 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1946 CONFIG_SYS_SPD_BUS_NUM
1948 If defined, then this indicates the I2C bus number for DDR SPD.
1949 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1951 CONFIG_SYS_RTC_BUS_NUM
1953 If defined, then this indicates the I2C bus number for the RTC.
1954 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1956 CONFIG_SYS_DTT_BUS_NUM
1958 If defined, then this indicates the I2C bus number for the DTT.
1959 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1961 CONFIG_SYS_I2C_DTT_ADDR:
1963 If defined, specifies the I2C address of the DTT device.
1964 If not defined, then U-Boot uses predefined value for
1965 specified DTT device.
1969 Define this option if you want to use Freescale's I2C driver in
1970 drivers/i2c/fsl_i2c.c.
1974 Define this option if you have I2C devices reached over 1 .. n
1975 I2C Muxes like the pca9544a. This option addes a new I2C
1976 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1977 new I2C Bus to the existing I2C Busses. If you select the
1978 new Bus with "i2c dev", u-bbot sends first the commandos for
1979 the muxes to activate this new "bus".
1981 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1985 Adding a new I2C Bus reached over 2 pca9544a muxes
1986 The First mux with address 70 and channel 6
1987 The Second mux with address 71 and channel 4
1989 => i2c bus pca9544a:70:6:pca9544a:71:4
1991 Use the "i2c bus" command without parameter, to get a list
1992 of I2C Busses with muxes:
1995 Busses reached over muxes:
1997 reached over Mux(es):
2000 reached over Mux(es):
2005 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2006 u-boot first sends the command to the mux@70 to enable
2007 channel 6, and then the command to the mux@71 to enable
2010 After that, you can use the "normal" i2c commands as
2011 usual to communicate with your I2C devices behind
2014 This option is actually implemented for the bitbanging
2015 algorithm in common/soft_i2c.c and for the Hardware I2C
2016 Bus on the MPC8260. But it should be not so difficult
2017 to add this option to other architectures.
2019 CONFIG_SOFT_I2C_READ_REPEATED_START
2021 defining this will force the i2c_read() function in
2022 the soft_i2c driver to perform an I2C repeated start
2023 between writing the address pointer and reading the
2024 data. If this define is omitted the default behaviour
2025 of doing a stop-start sequence will be used. Most I2C
2026 devices can use either method, but some require one or
2029 - SPI Support: CONFIG_SPI
2031 Enables SPI driver (so far only tested with
2032 SPI EEPROM, also an instance works with Crystal A/D and
2033 D/As on the SACSng board)
2037 Enables the driver for SPI controller on SuperH. Currently
2038 only SH7757 is supported.
2042 Enables extended (16-bit) SPI EEPROM addressing.
2043 (symmetrical to CONFIG_I2C_X)
2047 Enables a software (bit-bang) SPI driver rather than
2048 using hardware support. This is a general purpose
2049 driver that only requires three general I/O port pins
2050 (two outputs, one input) to function. If this is
2051 defined, the board configuration must define several
2052 SPI configuration items (port pins to use, etc). For
2053 an example, see include/configs/sacsng.h.
2057 Enables a hardware SPI driver for general-purpose reads
2058 and writes. As with CONFIG_SOFT_SPI, the board configuration
2059 must define a list of chip-select function pointers.
2060 Currently supported on some MPC8xxx processors. For an
2061 example, see include/configs/mpc8349emds.h.
2065 Enables the driver for the SPI controllers on i.MX and MXC
2066 SoCs. Currently i.MX31/35/51 are supported.
2068 - FPGA Support: CONFIG_FPGA
2070 Enables FPGA subsystem.
2072 CONFIG_FPGA_<vendor>
2074 Enables support for specific chip vendors.
2077 CONFIG_FPGA_<family>
2079 Enables support for FPGA family.
2080 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2084 Specify the number of FPGA devices to support.
2086 CONFIG_SYS_FPGA_PROG_FEEDBACK
2088 Enable printing of hash marks during FPGA configuration.
2090 CONFIG_SYS_FPGA_CHECK_BUSY
2092 Enable checks on FPGA configuration interface busy
2093 status by the configuration function. This option
2094 will require a board or device specific function to
2099 If defined, a function that provides delays in the FPGA
2100 configuration driver.
2102 CONFIG_SYS_FPGA_CHECK_CTRLC
2103 Allow Control-C to interrupt FPGA configuration
2105 CONFIG_SYS_FPGA_CHECK_ERROR
2107 Check for configuration errors during FPGA bitfile
2108 loading. For example, abort during Virtex II
2109 configuration if the INIT_B line goes low (which
2110 indicated a CRC error).
2112 CONFIG_SYS_FPGA_WAIT_INIT
2114 Maximum time to wait for the INIT_B line to deassert
2115 after PROB_B has been deasserted during a Virtex II
2116 FPGA configuration sequence. The default time is 500
2119 CONFIG_SYS_FPGA_WAIT_BUSY
2121 Maximum time to wait for BUSY to deassert during
2122 Virtex II FPGA configuration. The default is 5 ms.
2124 CONFIG_SYS_FPGA_WAIT_CONFIG
2126 Time to wait after FPGA configuration. The default is
2129 - Configuration Management:
2132 If defined, this string will be added to the U-Boot
2133 version information (U_BOOT_VERSION)
2135 - Vendor Parameter Protection:
2137 U-Boot considers the values of the environment
2138 variables "serial#" (Board Serial Number) and
2139 "ethaddr" (Ethernet Address) to be parameters that
2140 are set once by the board vendor / manufacturer, and
2141 protects these variables from casual modification by
2142 the user. Once set, these variables are read-only,
2143 and write or delete attempts are rejected. You can
2144 change this behaviour:
2146 If CONFIG_ENV_OVERWRITE is #defined in your config
2147 file, the write protection for vendor parameters is
2148 completely disabled. Anybody can change or delete
2151 Alternatively, if you #define _both_ CONFIG_ETHADDR
2152 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2153 Ethernet address is installed in the environment,
2154 which can be changed exactly ONCE by the user. [The
2155 serial# is unaffected by this, i. e. it remains
2161 Define this variable to enable the reservation of
2162 "protected RAM", i. e. RAM which is not overwritten
2163 by U-Boot. Define CONFIG_PRAM to hold the number of
2164 kB you want to reserve for pRAM. You can overwrite
2165 this default value by defining an environment
2166 variable "pram" to the number of kB you want to
2167 reserve. Note that the board info structure will
2168 still show the full amount of RAM. If pRAM is
2169 reserved, a new environment variable "mem" will
2170 automatically be defined to hold the amount of
2171 remaining RAM in a form that can be passed as boot
2172 argument to Linux, for instance like that:
2174 setenv bootargs ... mem=\${mem}
2177 This way you can tell Linux not to use this memory,
2178 either, which results in a memory region that will
2179 not be affected by reboots.
2181 *WARNING* If your board configuration uses automatic
2182 detection of the RAM size, you must make sure that
2183 this memory test is non-destructive. So far, the
2184 following board configurations are known to be
2187 IVMS8, IVML24, SPD8xx, TQM8xxL,
2188 HERMES, IP860, RPXlite, LWMON,
2194 Define this variable to stop the system in case of a
2195 fatal error, so that you have to reset it manually.
2196 This is probably NOT a good idea for an embedded
2197 system where you want the system to reboot
2198 automatically as fast as possible, but it may be
2199 useful during development since you can try to debug
2200 the conditions that lead to the situation.
2202 CONFIG_NET_RETRY_COUNT
2204 This variable defines the number of retries for
2205 network operations like ARP, RARP, TFTP, or BOOTP
2206 before giving up the operation. If not defined, a
2207 default value of 5 is used.
2211 Timeout waiting for an ARP reply in milliseconds.
2215 Timeout in milliseconds used in NFS protocol.
2216 If you encounter "ERROR: Cannot umount" in nfs command,
2217 try longer timeout such as
2218 #define CONFIG_NFS_TIMEOUT 10000UL
2220 - Command Interpreter:
2221 CONFIG_AUTO_COMPLETE
2223 Enable auto completion of commands using TAB.
2225 Note that this feature has NOT been implemented yet
2226 for the "hush" shell.
2229 CONFIG_SYS_HUSH_PARSER
2231 Define this variable to enable the "hush" shell (from
2232 Busybox) as command line interpreter, thus enabling
2233 powerful command line syntax like
2234 if...then...else...fi conditionals or `&&' and '||'
2235 constructs ("shell scripts").
2237 If undefined, you get the old, much simpler behaviour
2238 with a somewhat smaller memory footprint.
2241 CONFIG_SYS_PROMPT_HUSH_PS2
2243 This defines the secondary prompt string, which is
2244 printed when the command interpreter needs more input
2245 to complete a command. Usually "> ".
2249 In the current implementation, the local variables
2250 space and global environment variables space are
2251 separated. Local variables are those you define by
2252 simply typing `name=value'. To access a local
2253 variable later on, you have write `$name' or
2254 `${name}'; to execute the contents of a variable
2255 directly type `$name' at the command prompt.
2257 Global environment variables are those you use
2258 setenv/printenv to work with. To run a command stored
2259 in such a variable, you need to use the run command,
2260 and you must not use the '$' sign to access them.
2262 To store commands and special characters in a
2263 variable, please use double quotation marks
2264 surrounding the whole text of the variable, instead
2265 of the backslashes before semicolons and special
2268 - Commandline Editing and History:
2269 CONFIG_CMDLINE_EDITING
2271 Enable editing and History functions for interactive
2272 commandline input operations
2274 - Default Environment:
2275 CONFIG_EXTRA_ENV_SETTINGS
2277 Define this to contain any number of null terminated
2278 strings (variable = value pairs) that will be part of
2279 the default environment compiled into the boot image.
2281 For example, place something like this in your
2282 board's config file:
2284 #define CONFIG_EXTRA_ENV_SETTINGS \
2288 Warning: This method is based on knowledge about the
2289 internal format how the environment is stored by the
2290 U-Boot code. This is NOT an official, exported
2291 interface! Although it is unlikely that this format
2292 will change soon, there is no guarantee either.
2293 You better know what you are doing here.
2295 Note: overly (ab)use of the default environment is
2296 discouraged. Make sure to check other ways to preset
2297 the environment like the "source" command or the
2300 CONFIG_ENV_VARS_UBOOT_CONFIG
2302 Define this in order to add variables describing the
2303 U-Boot build configuration to the default environment.
2304 These will be named arch, cpu, board, vendor, and soc.
2306 Enabling this option will cause the following to be defined:
2314 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2316 Define this in order to add variables describing certain
2317 run-time determined information about the hardware to the
2318 environment. These will be named board_name, board_rev.
2320 - DataFlash Support:
2321 CONFIG_HAS_DATAFLASH
2323 Defining this option enables DataFlash features and
2324 allows to read/write in Dataflash via the standard
2327 - Serial Flash support
2330 Defining this option enables SPI flash commands
2331 'sf probe/read/write/erase/update'.
2333 Usage requires an initial 'probe' to define the serial
2334 flash parameters, followed by read/write/erase/update
2337 The following defaults may be provided by the platform
2338 to handle the common case when only a single serial
2339 flash is present on the system.
2341 CONFIG_SF_DEFAULT_BUS Bus identifier
2342 CONFIG_SF_DEFAULT_CS Chip-select
2343 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2344 CONFIG_SF_DEFAULT_SPEED in Hz
2346 - SystemACE Support:
2349 Adding this option adds support for Xilinx SystemACE
2350 chips attached via some sort of local bus. The address
2351 of the chip must also be defined in the
2352 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2354 #define CONFIG_SYSTEMACE
2355 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2357 When SystemACE support is added, the "ace" device type
2358 becomes available to the fat commands, i.e. fatls.
2360 - TFTP Fixed UDP Port:
2363 If this is defined, the environment variable tftpsrcp
2364 is used to supply the TFTP UDP source port value.
2365 If tftpsrcp isn't defined, the normal pseudo-random port
2366 number generator is used.
2368 Also, the environment variable tftpdstp is used to supply
2369 the TFTP UDP destination port value. If tftpdstp isn't
2370 defined, the normal port 69 is used.
2372 The purpose for tftpsrcp is to allow a TFTP server to
2373 blindly start the TFTP transfer using the pre-configured
2374 target IP address and UDP port. This has the effect of
2375 "punching through" the (Windows XP) firewall, allowing
2376 the remainder of the TFTP transfer to proceed normally.
2377 A better solution is to properly configure the firewall,
2378 but sometimes that is not allowed.
2380 - Show boot progress:
2381 CONFIG_SHOW_BOOT_PROGRESS
2383 Defining this option allows to add some board-
2384 specific code (calling a user-provided function
2385 "show_boot_progress(int)") that enables you to show
2386 the system's boot progress on some display (for
2387 example, some LED's) on your board. At the moment,
2388 the following checkpoints are implemented:
2390 - Detailed boot stage timing
2392 Define this option to get detailed timing of each stage
2393 of the boot process.
2395 CONFIG_BOOTSTAGE_USER_COUNT
2396 This is the number of available user bootstage records.
2397 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2398 a new ID will be allocated from this stash. If you exceed
2399 the limit, recording will stop.
2401 CONFIG_BOOTSTAGE_REPORT
2402 Define this to print a report before boot, similar to this:
2404 Timer summary in microseconds:
2407 3,575,678 3,575,678 board_init_f start
2408 3,575,695 17 arch_cpu_init A9
2409 3,575,777 82 arch_cpu_init done
2410 3,659,598 83,821 board_init_r start
2411 3,910,375 250,777 main_loop
2412 29,916,167 26,005,792 bootm_start
2413 30,361,327 445,160 start_kernel
2415 CONFIG_CMD_BOOTSTAGE
2416 Add a 'bootstage' command which supports printing a report
2417 and un/stashing of bootstage data.
2419 CONFIG_BOOTSTAGE_FDT
2420 Stash the bootstage information in the FDT. A root 'bootstage'
2421 node is created with each bootstage id as a child. Each child
2422 has a 'name' property and either 'mark' containing the
2423 mark time in microsecond, or 'accum' containing the
2424 accumulated time for that bootstage id in microseconds.
2429 name = "board_init_f";
2438 Code in the Linux kernel can find this in /proc/devicetree.
2440 Legacy uImage format:
2443 1 common/cmd_bootm.c before attempting to boot an image
2444 -1 common/cmd_bootm.c Image header has bad magic number
2445 2 common/cmd_bootm.c Image header has correct magic number
2446 -2 common/cmd_bootm.c Image header has bad checksum
2447 3 common/cmd_bootm.c Image header has correct checksum
2448 -3 common/cmd_bootm.c Image data has bad checksum
2449 4 common/cmd_bootm.c Image data has correct checksum
2450 -4 common/cmd_bootm.c Image is for unsupported architecture
2451 5 common/cmd_bootm.c Architecture check OK
2452 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2453 6 common/cmd_bootm.c Image Type check OK
2454 -6 common/cmd_bootm.c gunzip uncompression error
2455 -7 common/cmd_bootm.c Unimplemented compression type
2456 7 common/cmd_bootm.c Uncompression OK
2457 8 common/cmd_bootm.c No uncompress/copy overwrite error
2458 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2460 9 common/image.c Start initial ramdisk verification
2461 -10 common/image.c Ramdisk header has bad magic number
2462 -11 common/image.c Ramdisk header has bad checksum
2463 10 common/image.c Ramdisk header is OK
2464 -12 common/image.c Ramdisk data has bad checksum
2465 11 common/image.c Ramdisk data has correct checksum
2466 12 common/image.c Ramdisk verification complete, start loading
2467 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2468 13 common/image.c Start multifile image verification
2469 14 common/image.c No initial ramdisk, no multifile, continue.
2471 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2473 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2474 -31 post/post.c POST test failed, detected by post_output_backlog()
2475 -32 post/post.c POST test failed, detected by post_run_single()
2477 34 common/cmd_doc.c before loading a Image from a DOC device
2478 -35 common/cmd_doc.c Bad usage of "doc" command
2479 35 common/cmd_doc.c correct usage of "doc" command
2480 -36 common/cmd_doc.c No boot device
2481 36 common/cmd_doc.c correct boot device
2482 -37 common/cmd_doc.c Unknown Chip ID on boot device
2483 37 common/cmd_doc.c correct chip ID found, device available
2484 -38 common/cmd_doc.c Read Error on boot device
2485 38 common/cmd_doc.c reading Image header from DOC device OK
2486 -39 common/cmd_doc.c Image header has bad magic number
2487 39 common/cmd_doc.c Image header has correct magic number
2488 -40 common/cmd_doc.c Error reading Image from DOC device
2489 40 common/cmd_doc.c Image header has correct magic number
2490 41 common/cmd_ide.c before loading a Image from a IDE device
2491 -42 common/cmd_ide.c Bad usage of "ide" command
2492 42 common/cmd_ide.c correct usage of "ide" command
2493 -43 common/cmd_ide.c No boot device
2494 43 common/cmd_ide.c boot device found
2495 -44 common/cmd_ide.c Device not available
2496 44 common/cmd_ide.c Device available
2497 -45 common/cmd_ide.c wrong partition selected
2498 45 common/cmd_ide.c partition selected
2499 -46 common/cmd_ide.c Unknown partition table
2500 46 common/cmd_ide.c valid partition table found
2501 -47 common/cmd_ide.c Invalid partition type
2502 47 common/cmd_ide.c correct partition type
2503 -48 common/cmd_ide.c Error reading Image Header on boot device
2504 48 common/cmd_ide.c reading Image Header from IDE device OK
2505 -49 common/cmd_ide.c Image header has bad magic number
2506 49 common/cmd_ide.c Image header has correct magic number
2507 -50 common/cmd_ide.c Image header has bad checksum
2508 50 common/cmd_ide.c Image header has correct checksum
2509 -51 common/cmd_ide.c Error reading Image from IDE device
2510 51 common/cmd_ide.c reading Image from IDE device OK
2511 52 common/cmd_nand.c before loading a Image from a NAND device
2512 -53 common/cmd_nand.c Bad usage of "nand" command
2513 53 common/cmd_nand.c correct usage of "nand" command
2514 -54 common/cmd_nand.c No boot device
2515 54 common/cmd_nand.c boot device found
2516 -55 common/cmd_nand.c Unknown Chip ID on boot device
2517 55 common/cmd_nand.c correct chip ID found, device available
2518 -56 common/cmd_nand.c Error reading Image Header on boot device
2519 56 common/cmd_nand.c reading Image Header from NAND device OK
2520 -57 common/cmd_nand.c Image header has bad magic number
2521 57 common/cmd_nand.c Image header has correct magic number
2522 -58 common/cmd_nand.c Error reading Image from NAND device
2523 58 common/cmd_nand.c reading Image from NAND device OK
2525 -60 common/env_common.c Environment has a bad CRC, using default
2527 64 net/eth.c starting with Ethernet configuration.
2528 -64 net/eth.c no Ethernet found.
2529 65 net/eth.c Ethernet found.
2531 -80 common/cmd_net.c usage wrong
2532 80 common/cmd_net.c before calling NetLoop()
2533 -81 common/cmd_net.c some error in NetLoop() occurred
2534 81 common/cmd_net.c NetLoop() back without error
2535 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2536 82 common/cmd_net.c trying automatic boot
2537 83 common/cmd_net.c running "source" command
2538 -83 common/cmd_net.c some error in automatic boot or "source" command
2539 84 common/cmd_net.c end without errors
2544 100 common/cmd_bootm.c Kernel FIT Image has correct format
2545 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2546 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2547 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2548 102 common/cmd_bootm.c Kernel unit name specified
2549 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2550 103 common/cmd_bootm.c Found configuration node
2551 104 common/cmd_bootm.c Got kernel subimage node offset
2552 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2553 105 common/cmd_bootm.c Kernel subimage hash verification OK
2554 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2555 106 common/cmd_bootm.c Architecture check OK
2556 -106 common/cmd_bootm.c Kernel subimage has wrong type
2557 107 common/cmd_bootm.c Kernel subimage type OK
2558 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2559 108 common/cmd_bootm.c Got kernel subimage data/size
2560 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2561 -109 common/cmd_bootm.c Can't get kernel subimage type
2562 -110 common/cmd_bootm.c Can't get kernel subimage comp
2563 -111 common/cmd_bootm.c Can't get kernel subimage os
2564 -112 common/cmd_bootm.c Can't get kernel subimage load address
2565 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2567 120 common/image.c Start initial ramdisk verification
2568 -120 common/image.c Ramdisk FIT image has incorrect format
2569 121 common/image.c Ramdisk FIT image has correct format
2570 122 common/image.c No ramdisk subimage unit name, using configuration
2571 -122 common/image.c Can't get configuration for ramdisk subimage
2572 123 common/image.c Ramdisk unit name specified
2573 -124 common/image.c Can't get ramdisk subimage node offset
2574 125 common/image.c Got ramdisk subimage node offset
2575 -125 common/image.c Ramdisk subimage hash verification failed
2576 126 common/image.c Ramdisk subimage hash verification OK
2577 -126 common/image.c Ramdisk subimage for unsupported architecture
2578 127 common/image.c Architecture check OK
2579 -127 common/image.c Can't get ramdisk subimage data/size
2580 128 common/image.c Got ramdisk subimage data/size
2581 129 common/image.c Can't get ramdisk load address
2582 -129 common/image.c Got ramdisk load address
2584 -130 common/cmd_doc.c Incorrect FIT image format
2585 131 common/cmd_doc.c FIT image format OK
2587 -140 common/cmd_ide.c Incorrect FIT image format
2588 141 common/cmd_ide.c FIT image format OK
2590 -150 common/cmd_nand.c Incorrect FIT image format
2591 151 common/cmd_nand.c FIT image format OK
2593 - Standalone program support:
2594 CONFIG_STANDALONE_LOAD_ADDR
2596 This option defines a board specific value for the
2597 address where standalone program gets loaded, thus
2598 overwriting the architecture dependent default
2601 - Frame Buffer Address:
2604 Define CONFIG_FB_ADDR if you want to use specific
2605 address for frame buffer.
2606 Then system will reserve the frame buffer address to
2607 defined address instead of lcd_setmem (this function
2608 grabs the memory for frame buffer by panel's size).
2610 Please see board_init_f function.
2612 - Automatic software updates via TFTP server
2614 CONFIG_UPDATE_TFTP_CNT_MAX
2615 CONFIG_UPDATE_TFTP_MSEC_MAX
2617 These options enable and control the auto-update feature;
2618 for a more detailed description refer to doc/README.update.
2620 - MTD Support (mtdparts command, UBI support)
2623 Adds the MTD device infrastructure from the Linux kernel.
2624 Needed for mtdparts command support.
2626 CONFIG_MTD_PARTITIONS
2628 Adds the MTD partitioning infrastructure from the Linux
2629 kernel. Needed for UBI support.
2633 Enable building of SPL globally.
2636 LDSCRIPT for linking the SPL binary.
2639 Maximum binary size (text, data and rodata) of the SPL binary.
2641 CONFIG_SPL_TEXT_BASE
2642 TEXT_BASE for linking the SPL binary.
2644 CONFIG_SPL_BSS_START_ADDR
2645 Link address for the BSS within the SPL binary.
2647 CONFIG_SPL_BSS_MAX_SIZE
2648 Maximum binary size of the BSS section of the SPL binary.
2651 Adress of the start of the stack SPL will use
2653 CONFIG_SYS_SPL_MALLOC_START
2654 Starting address of the malloc pool used in SPL.
2656 CONFIG_SYS_SPL_MALLOC_SIZE
2657 The size of the malloc pool used in SPL.
2659 CONFIG_SPL_FRAMEWORK
2660 Enable the SPL framework under common/. This framework
2661 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2662 NAND loading of the Linux Kernel.
2664 CONFIG_SPL_DISPLAY_PRINT
2665 For ARM, enable an optional function to print more information
2666 about the running system.
2668 CONFIG_SPL_LIBCOMMON_SUPPORT
2669 Support for common/libcommon.o in SPL binary
2671 CONFIG_SPL_LIBDISK_SUPPORT
2672 Support for disk/libdisk.o in SPL binary
2674 CONFIG_SPL_I2C_SUPPORT
2675 Support for drivers/i2c/libi2c.o in SPL binary
2677 CONFIG_SPL_GPIO_SUPPORT
2678 Support for drivers/gpio/libgpio.o in SPL binary
2680 CONFIG_SPL_MMC_SUPPORT
2681 Support for drivers/mmc/libmmc.o in SPL binary
2683 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2684 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2685 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2686 Address, size and partition on the MMC to load U-Boot from
2687 when the MMC is being used in raw mode.
2689 CONFIG_SPL_FAT_SUPPORT
2690 Support for fs/fat/libfat.o in SPL binary
2692 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2693 Filename to read to load U-Boot when reading from FAT
2695 CONFIG_SPL_NAND_SIMPLE
2696 Support for drivers/mtd/nand/libnand.o in SPL binary
2698 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2699 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2700 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2701 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2702 CONFIG_SYS_NAND_ECCBYTES
2703 Defines the size and behavior of the NAND that SPL uses
2704 to read U-Boot with CONFIG_SPL_NAND_SIMPLE
2706 CONFIG_SYS_NAND_U_BOOT_OFFS
2707 Location in NAND for CONFIG_SPL_NAND_SIMPLE to read U-Boot
2710 CONFIG_SYS_NAND_U_BOOT_START
2711 Location in memory for CONFIG_SPL_NAND_SIMPLE to load U-Boot
2714 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2715 Define this if you need to first read the OOB and then the
2716 data. This is used for example on davinci plattforms.
2718 CONFIG_SPL_OMAP3_ID_NAND
2719 Support for an OMAP3-specific set of functions to return the
2720 ID and MFR of the first attached NAND chip, if present.
2722 CONFIG_SPL_SERIAL_SUPPORT
2723 Support for drivers/serial/libserial.o in SPL binary
2725 CONFIG_SPL_SPI_FLASH_SUPPORT
2726 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2728 CONFIG_SPL_SPI_SUPPORT
2729 Support for drivers/spi/libspi.o in SPL binary
2731 CONFIG_SPL_RAM_DEVICE
2732 Support for running image already present in ram, in SPL binary
2734 CONFIG_SPL_LIBGENERIC_SUPPORT
2735 Support for lib/libgeneric.o in SPL binary
2740 [so far only for SMDK2400 boards]
2742 - Modem support enable:
2743 CONFIG_MODEM_SUPPORT
2745 - RTS/CTS Flow control enable:
2748 - Modem debug support:
2749 CONFIG_MODEM_SUPPORT_DEBUG
2751 Enables debugging stuff (char screen[1024], dbg())
2752 for modem support. Useful only with BDI2000.
2754 - Interrupt support (PPC):
2756 There are common interrupt_init() and timer_interrupt()
2757 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2758 for CPU specific initialization. interrupt_init_cpu()
2759 should set decrementer_count to appropriate value. If
2760 CPU resets decrementer automatically after interrupt
2761 (ppc4xx) it should set decrementer_count to zero.
2762 timer_interrupt() calls timer_interrupt_cpu() for CPU
2763 specific handling. If board has watchdog / status_led
2764 / other_activity_monitor it works automatically from
2765 general timer_interrupt().
2769 In the target system modem support is enabled when a
2770 specific key (key combination) is pressed during
2771 power-on. Otherwise U-Boot will boot normally
2772 (autoboot). The key_pressed() function is called from
2773 board_init(). Currently key_pressed() is a dummy
2774 function, returning 1 and thus enabling modem
2777 If there are no modem init strings in the
2778 environment, U-Boot proceed to autoboot; the
2779 previous output (banner, info printfs) will be
2782 See also: doc/README.Modem
2784 Board initialization settings:
2785 ------------------------------
2787 During Initialization u-boot calls a number of board specific functions
2788 to allow the preparation of board specific prerequisites, e.g. pin setup
2789 before drivers are initialized. To enable these callbacks the
2790 following configuration macros have to be defined. Currently this is
2791 architecture specific, so please check arch/your_architecture/lib/board.c
2792 typically in board_init_f() and board_init_r().
2794 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2795 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2796 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2797 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2799 Configuration Settings:
2800 -----------------------
2802 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2803 undefine this when you're short of memory.
2805 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2806 width of the commands listed in the 'help' command output.
2808 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2809 prompt for user input.
2811 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2813 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2815 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2817 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2818 the application (usually a Linux kernel) when it is
2821 - CONFIG_SYS_BAUDRATE_TABLE:
2822 List of legal baudrate settings for this board.
2824 - CONFIG_SYS_CONSOLE_INFO_QUIET
2825 Suppress display of console information at boot.
2827 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2828 If the board specific function
2829 extern int overwrite_console (void);
2830 returns 1, the stdin, stderr and stdout are switched to the
2831 serial port, else the settings in the environment are used.
2833 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2834 Enable the call to overwrite_console().
2836 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2837 Enable overwrite of previous console environment settings.
2839 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2840 Begin and End addresses of the area used by the
2843 - CONFIG_SYS_ALT_MEMTEST:
2844 Enable an alternate, more extensive memory test.
2846 - CONFIG_SYS_MEMTEST_SCRATCH:
2847 Scratch address used by the alternate memory test
2848 You only need to set this if address zero isn't writeable
2850 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2851 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2852 this specified memory area will get subtracted from the top
2853 (end) of RAM and won't get "touched" at all by U-Boot. By
2854 fixing up gd->ram_size the Linux kernel should gets passed
2855 the now "corrected" memory size and won't touch it either.
2856 This should work for arch/ppc and arch/powerpc. Only Linux
2857 board ports in arch/powerpc with bootwrapper support that
2858 recalculate the memory size from the SDRAM controller setup
2859 will have to get fixed in Linux additionally.
2861 This option can be used as a workaround for the 440EPx/GRx
2862 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2865 WARNING: Please make sure that this value is a multiple of
2866 the Linux page size (normally 4k). If this is not the case,
2867 then the end address of the Linux memory will be located at a
2868 non page size aligned address and this could cause major
2871 - CONFIG_SYS_TFTP_LOADADDR:
2872 Default load address for network file downloads
2874 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2875 Enable temporary baudrate change while serial download
2877 - CONFIG_SYS_SDRAM_BASE:
2878 Physical start address of SDRAM. _Must_ be 0 here.
2880 - CONFIG_SYS_MBIO_BASE:
2881 Physical start address of Motherboard I/O (if using a
2884 - CONFIG_SYS_FLASH_BASE:
2885 Physical start address of Flash memory.
2887 - CONFIG_SYS_MONITOR_BASE:
2888 Physical start address of boot monitor code (set by
2889 make config files to be same as the text base address
2890 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2891 CONFIG_SYS_FLASH_BASE when booting from flash.
2893 - CONFIG_SYS_MONITOR_LEN:
2894 Size of memory reserved for monitor code, used to
2895 determine _at_compile_time_ (!) if the environment is
2896 embedded within the U-Boot image, or in a separate
2899 - CONFIG_SYS_MALLOC_LEN:
2900 Size of DRAM reserved for malloc() use.
2902 - CONFIG_SYS_BOOTM_LEN:
2903 Normally compressed uImages are limited to an
2904 uncompressed size of 8 MBytes. If this is not enough,
2905 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2906 to adjust this setting to your needs.
2908 - CONFIG_SYS_BOOTMAPSZ:
2909 Maximum size of memory mapped by the startup code of
2910 the Linux kernel; all data that must be processed by
2911 the Linux kernel (bd_info, boot arguments, FDT blob if
2912 used) must be put below this limit, unless "bootm_low"
2913 enviroment variable is defined and non-zero. In such case
2914 all data for the Linux kernel must be between "bootm_low"
2915 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2916 variable "bootm_mapsize" will override the value of
2917 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2918 then the value in "bootm_size" will be used instead.
2920 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2921 Enable initrd_high functionality. If defined then the
2922 initrd_high feature is enabled and the bootm ramdisk subcommand
2925 - CONFIG_SYS_BOOT_GET_CMDLINE:
2926 Enables allocating and saving kernel cmdline in space between
2927 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2929 - CONFIG_SYS_BOOT_GET_KBD:
2930 Enables allocating and saving a kernel copy of the bd_info in
2931 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2933 - CONFIG_SYS_MAX_FLASH_BANKS:
2934 Max number of Flash memory banks
2936 - CONFIG_SYS_MAX_FLASH_SECT:
2937 Max number of sectors on a Flash chip
2939 - CONFIG_SYS_FLASH_ERASE_TOUT:
2940 Timeout for Flash erase operations (in ms)
2942 - CONFIG_SYS_FLASH_WRITE_TOUT:
2943 Timeout for Flash write operations (in ms)
2945 - CONFIG_SYS_FLASH_LOCK_TOUT
2946 Timeout for Flash set sector lock bit operation (in ms)
2948 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2949 Timeout for Flash clear lock bits operation (in ms)
2951 - CONFIG_SYS_FLASH_PROTECTION
2952 If defined, hardware flash sectors protection is used
2953 instead of U-Boot software protection.
2955 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2957 Enable TFTP transfers directly to flash memory;
2958 without this option such a download has to be
2959 performed in two steps: (1) download to RAM, and (2)
2960 copy from RAM to flash.
2962 The two-step approach is usually more reliable, since
2963 you can check if the download worked before you erase
2964 the flash, but in some situations (when system RAM is
2965 too limited to allow for a temporary copy of the
2966 downloaded image) this option may be very useful.
2968 - CONFIG_SYS_FLASH_CFI:
2969 Define if the flash driver uses extra elements in the
2970 common flash structure for storing flash geometry.
2972 - CONFIG_FLASH_CFI_DRIVER
2973 This option also enables the building of the cfi_flash driver
2974 in the drivers directory
2976 - CONFIG_FLASH_CFI_MTD
2977 This option enables the building of the cfi_mtd driver
2978 in the drivers directory. The driver exports CFI flash
2981 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2982 Use buffered writes to flash.
2984 - CONFIG_FLASH_SPANSION_S29WS_N
2985 s29ws-n MirrorBit flash has non-standard addresses for buffered
2988 - CONFIG_SYS_FLASH_QUIET_TEST
2989 If this option is defined, the common CFI flash doesn't
2990 print it's warning upon not recognized FLASH banks. This
2991 is useful, if some of the configured banks are only
2992 optionally available.
2994 - CONFIG_FLASH_SHOW_PROGRESS
2995 If defined (must be an integer), print out countdown
2996 digits and dots. Recommended value: 45 (9..1) for 80
2997 column displays, 15 (3..1) for 40 column displays.
2999 - CONFIG_SYS_RX_ETH_BUFFER:
3000 Defines the number of Ethernet receive buffers. On some
3001 Ethernet controllers it is recommended to set this value
3002 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3003 buffers can be full shortly after enabling the interface
3004 on high Ethernet traffic.
3005 Defaults to 4 if not defined.
3007 - CONFIG_ENV_MAX_ENTRIES
3009 Maximum number of entries in the hash table that is used
3010 internally to store the environment settings. The default
3011 setting is supposed to be generous and should work in most
3012 cases. This setting can be used to tune behaviour; see
3013 lib/hashtable.c for details.
3015 The following definitions that deal with the placement and management
3016 of environment data (variable area); in general, we support the
3017 following configurations:
3019 - CONFIG_BUILD_ENVCRC:
3021 Builds up envcrc with the target environment so that external utils
3022 may easily extract it and embed it in final U-Boot images.
3024 - CONFIG_ENV_IS_IN_FLASH:
3026 Define this if the environment is in flash memory.
3028 a) The environment occupies one whole flash sector, which is
3029 "embedded" in the text segment with the U-Boot code. This
3030 happens usually with "bottom boot sector" or "top boot
3031 sector" type flash chips, which have several smaller
3032 sectors at the start or the end. For instance, such a
3033 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3034 such a case you would place the environment in one of the
3035 4 kB sectors - with U-Boot code before and after it. With
3036 "top boot sector" type flash chips, you would put the
3037 environment in one of the last sectors, leaving a gap
3038 between U-Boot and the environment.
3040 - CONFIG_ENV_OFFSET:
3042 Offset of environment data (variable area) to the
3043 beginning of flash memory; for instance, with bottom boot
3044 type flash chips the second sector can be used: the offset
3045 for this sector is given here.
3047 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3051 This is just another way to specify the start address of
3052 the flash sector containing the environment (instead of
3055 - CONFIG_ENV_SECT_SIZE:
3057 Size of the sector containing the environment.
3060 b) Sometimes flash chips have few, equal sized, BIG sectors.
3061 In such a case you don't want to spend a whole sector for
3066 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3067 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3068 of this flash sector for the environment. This saves
3069 memory for the RAM copy of the environment.
3071 It may also save flash memory if you decide to use this
3072 when your environment is "embedded" within U-Boot code,
3073 since then the remainder of the flash sector could be used
3074 for U-Boot code. It should be pointed out that this is
3075 STRONGLY DISCOURAGED from a robustness point of view:
3076 updating the environment in flash makes it always
3077 necessary to erase the WHOLE sector. If something goes
3078 wrong before the contents has been restored from a copy in
3079 RAM, your target system will be dead.
3081 - CONFIG_ENV_ADDR_REDUND
3082 CONFIG_ENV_SIZE_REDUND
3084 These settings describe a second storage area used to hold
3085 a redundant copy of the environment data, so that there is
3086 a valid backup copy in case there is a power failure during
3087 a "saveenv" operation.
3089 BE CAREFUL! Any changes to the flash layout, and some changes to the
3090 source code will make it necessary to adapt <board>/u-boot.lds*
3094 - CONFIG_ENV_IS_IN_NVRAM:
3096 Define this if you have some non-volatile memory device
3097 (NVRAM, battery buffered SRAM) which you want to use for the
3103 These two #defines are used to determine the memory area you
3104 want to use for environment. It is assumed that this memory
3105 can just be read and written to, without any special
3108 BE CAREFUL! The first access to the environment happens quite early
3109 in U-Boot initalization (when we try to get the setting of for the
3110 console baudrate). You *MUST* have mapped your NVRAM area then, or
3113 Please note that even with NVRAM we still use a copy of the
3114 environment in RAM: we could work on NVRAM directly, but we want to
3115 keep settings there always unmodified except somebody uses "saveenv"
3116 to save the current settings.
3119 - CONFIG_ENV_IS_IN_EEPROM:
3121 Use this if you have an EEPROM or similar serial access
3122 device and a driver for it.
3124 - CONFIG_ENV_OFFSET:
3127 These two #defines specify the offset and size of the
3128 environment area within the total memory of your EEPROM.
3130 - CONFIG_SYS_I2C_EEPROM_ADDR:
3131 If defined, specified the chip address of the EEPROM device.
3132 The default address is zero.
3134 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3135 If defined, the number of bits used to address bytes in a
3136 single page in the EEPROM device. A 64 byte page, for example
3137 would require six bits.
3139 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3140 If defined, the number of milliseconds to delay between
3141 page writes. The default is zero milliseconds.
3143 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3144 The length in bytes of the EEPROM memory array address. Note
3145 that this is NOT the chip address length!
3147 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3148 EEPROM chips that implement "address overflow" are ones
3149 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3150 address and the extra bits end up in the "chip address" bit
3151 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3154 Note that we consider the length of the address field to
3155 still be one byte because the extra address bits are hidden
3156 in the chip address.
3158 - CONFIG_SYS_EEPROM_SIZE:
3159 The size in bytes of the EEPROM device.
3161 - CONFIG_ENV_EEPROM_IS_ON_I2C
3162 define this, if you have I2C and SPI activated, and your
3163 EEPROM, which holds the environment, is on the I2C bus.
3165 - CONFIG_I2C_ENV_EEPROM_BUS
3166 if you have an Environment on an EEPROM reached over
3167 I2C muxes, you can define here, how to reach this
3168 EEPROM. For example:
3170 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3172 EEPROM which holds the environment, is reached over
3173 a pca9547 i2c mux with address 0x70, channel 3.
3175 - CONFIG_ENV_IS_IN_DATAFLASH:
3177 Define this if you have a DataFlash memory device which you
3178 want to use for the environment.
3180 - CONFIG_ENV_OFFSET:
3184 These three #defines specify the offset and size of the
3185 environment area within the total memory of your DataFlash placed
3186 at the specified address.
3188 - CONFIG_ENV_IS_IN_REMOTE:
3190 Define this if you have a remote memory space which you
3191 want to use for the local device's environment.
3196 These two #defines specify the address and size of the
3197 environment area within the remote memory space. The
3198 local device can get the environment from remote memory
3199 space by SRIO or PCIE links.
3201 BE CAREFUL! For some special cases, the local device can not use
3202 "saveenv" command. For example, the local device will get the
3203 environment stored in a remote NOR flash by SRIO or PCIE link,
3204 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3206 - CONFIG_ENV_IS_IN_NAND:
3208 Define this if you have a NAND device which you want to use
3209 for the environment.
3211 - CONFIG_ENV_OFFSET:
3214 These two #defines specify the offset and size of the environment
3215 area within the first NAND device. CONFIG_ENV_OFFSET must be
3216 aligned to an erase block boundary.
3218 - CONFIG_ENV_OFFSET_REDUND (optional):
3220 This setting describes a second storage area of CONFIG_ENV_SIZE
3221 size used to hold a redundant copy of the environment data, so
3222 that there is a valid backup copy in case there is a power failure
3223 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3224 aligned to an erase block boundary.
3226 - CONFIG_ENV_RANGE (optional):
3228 Specifies the length of the region in which the environment
3229 can be written. This should be a multiple of the NAND device's
3230 block size. Specifying a range with more erase blocks than
3231 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3232 the range to be avoided.
3234 - CONFIG_ENV_OFFSET_OOB (optional):
3236 Enables support for dynamically retrieving the offset of the
3237 environment from block zero's out-of-band data. The
3238 "nand env.oob" command can be used to record this offset.
3239 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3240 using CONFIG_ENV_OFFSET_OOB.
3242 - CONFIG_NAND_ENV_DST
3244 Defines address in RAM to which the nand_spl code should copy the
3245 environment. If redundant environment is used, it will be copied to
3246 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3248 - CONFIG_SYS_SPI_INIT_OFFSET
3250 Defines offset to the initial SPI buffer area in DPRAM. The
3251 area is used at an early stage (ROM part) if the environment
3252 is configured to reside in the SPI EEPROM: We need a 520 byte
3253 scratch DPRAM area. It is used between the two initialization
3254 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3255 to be a good choice since it makes it far enough from the
3256 start of the data area as well as from the stack pointer.
3258 Please note that the environment is read-only until the monitor
3259 has been relocated to RAM and a RAM copy of the environment has been
3260 created; also, when using EEPROM you will have to use getenv_f()
3261 until then to read environment variables.
3263 The environment is protected by a CRC32 checksum. Before the monitor
3264 is relocated into RAM, as a result of a bad CRC you will be working
3265 with the compiled-in default environment - *silently*!!! [This is
3266 necessary, because the first environment variable we need is the
3267 "baudrate" setting for the console - if we have a bad CRC, we don't
3268 have any device yet where we could complain.]
3270 Note: once the monitor has been relocated, then it will complain if
3271 the default environment is used; a new CRC is computed as soon as you
3272 use the "saveenv" command to store a valid environment.
3274 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3275 Echo the inverted Ethernet link state to the fault LED.
3277 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3278 also needs to be defined.
3280 - CONFIG_SYS_FAULT_MII_ADDR:
3281 MII address of the PHY to check for the Ethernet link state.
3283 - CONFIG_NS16550_MIN_FUNCTIONS:
3284 Define this if you desire to only have use of the NS16550_init
3285 and NS16550_putc functions for the serial driver located at
3286 drivers/serial/ns16550.c. This option is useful for saving
3287 space for already greatly restricted images, including but not
3288 limited to NAND_SPL configurations.
3290 Low Level (hardware related) configuration options:
3291 ---------------------------------------------------
3293 - CONFIG_SYS_CACHELINE_SIZE:
3294 Cache Line Size of the CPU.
3296 - CONFIG_SYS_DEFAULT_IMMR:
3297 Default address of the IMMR after system reset.
3299 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3300 and RPXsuper) to be able to adjust the position of
3301 the IMMR register after a reset.
3303 - CONFIG_SYS_CCSRBAR_DEFAULT:
3304 Default (power-on reset) physical address of CCSR on Freescale
3307 - CONFIG_SYS_CCSRBAR:
3308 Virtual address of CCSR. On a 32-bit build, this is typically
3309 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3311 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3312 for cross-platform code that uses that macro instead.
3314 - CONFIG_SYS_CCSRBAR_PHYS:
3315 Physical address of CCSR. CCSR can be relocated to a new
3316 physical address, if desired. In this case, this macro should
3317 be set to that address. Otherwise, it should be set to the
3318 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3319 is typically relocated on 36-bit builds. It is recommended
3320 that this macro be defined via the _HIGH and _LOW macros:
3322 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3323 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3325 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3326 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3327 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3328 used in assembly code, so it must not contain typecasts or
3329 integer size suffixes (e.g. "ULL").
3331 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3332 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3333 used in assembly code, so it must not contain typecasts or
3334 integer size suffixes (e.g. "ULL").
3336 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3337 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3338 forced to a value that ensures that CCSR is not relocated.
3340 - Floppy Disk Support:
3341 CONFIG_SYS_FDC_DRIVE_NUMBER
3343 the default drive number (default value 0)
3345 CONFIG_SYS_ISA_IO_STRIDE
3347 defines the spacing between FDC chipset registers
3350 CONFIG_SYS_ISA_IO_OFFSET
3352 defines the offset of register from address. It
3353 depends on which part of the data bus is connected to
3354 the FDC chipset. (default value 0)
3356 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3357 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3360 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3361 fdc_hw_init() is called at the beginning of the FDC
3362 setup. fdc_hw_init() must be provided by the board
3363 source code. It is used to make hardware dependant
3367 Most IDE controllers were designed to be connected with PCI
3368 interface. Only few of them were designed for AHB interface.
3369 When software is doing ATA command and data transfer to
3370 IDE devices through IDE-AHB controller, some additional
3371 registers accessing to these kind of IDE-AHB controller
3374 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3375 DO NOT CHANGE unless you know exactly what you're
3376 doing! (11-4) [MPC8xx/82xx systems only]
3378 - CONFIG_SYS_INIT_RAM_ADDR:
3380 Start address of memory area that can be used for
3381 initial data and stack; please note that this must be
3382 writable memory that is working WITHOUT special
3383 initialization, i. e. you CANNOT use normal RAM which
3384 will become available only after programming the
3385 memory controller and running certain initialization
3388 U-Boot uses the following memory types:
3389 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3390 - MPC824X: data cache
3391 - PPC4xx: data cache
3393 - CONFIG_SYS_GBL_DATA_OFFSET:
3395 Offset of the initial data structure in the memory
3396 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3397 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3398 data is located at the end of the available space
3399 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3400 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3401 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3402 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3405 On the MPC824X (or other systems that use the data
3406 cache for initial memory) the address chosen for
3407 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3408 point to an otherwise UNUSED address space between
3409 the top of RAM and the start of the PCI space.
3411 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3413 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3415 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3417 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3419 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3421 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3423 - CONFIG_SYS_OR_TIMING_SDRAM:
3426 - CONFIG_SYS_MAMR_PTA:
3427 periodic timer for refresh
3429 - CONFIG_SYS_DER: Debug Event Register (37-47)
3431 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3432 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3433 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3434 CONFIG_SYS_BR1_PRELIM:
3435 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3437 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3438 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3439 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3440 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3442 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3443 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3444 Machine Mode Register and Memory Periodic Timer
3445 Prescaler definitions (SDRAM timing)
3447 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3448 enable I2C microcode relocation patch (MPC8xx);
3449 define relocation offset in DPRAM [DSP2]
3451 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3452 enable SMC microcode relocation patch (MPC8xx);
3453 define relocation offset in DPRAM [SMC1]
3455 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3456 enable SPI microcode relocation patch (MPC8xx);
3457 define relocation offset in DPRAM [SCC4]
3459 - CONFIG_SYS_USE_OSCCLK:
3460 Use OSCM clock mode on MBX8xx board. Be careful,
3461 wrong setting might damage your board. Read
3462 doc/README.MBX before setting this variable!
3464 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3465 Offset of the bootmode word in DPRAM used by post
3466 (Power On Self Tests). This definition overrides
3467 #define'd default value in commproc.h resp.
3470 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3471 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3472 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3473 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3474 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3475 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3476 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3477 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3478 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3480 - CONFIG_PCI_DISABLE_PCIE:
3481 Disable PCI-Express on systems where it is supported but not
3484 - CONFIG_PCI_ENUM_ONLY
3485 Only scan through and get the devices on the busses.
3486 Don't do any setup work, presumably because someone or
3487 something has already done it, and we don't need to do it
3488 a second time. Useful for platforms that are pre-booted
3489 by coreboot or similar.
3492 Chip has SRIO or not
3495 Board has SRIO 1 port available
3498 Board has SRIO 2 port available
3500 - CONFIG_SYS_SRIOn_MEM_VIRT:
3501 Virtual Address of SRIO port 'n' memory region
3503 - CONFIG_SYS_SRIOn_MEM_PHYS:
3504 Physical Address of SRIO port 'n' memory region
3506 - CONFIG_SYS_SRIOn_MEM_SIZE:
3507 Size of SRIO port 'n' memory region
3509 - CONFIG_SYS_NDFC_16
3510 Defined to tell the NDFC that the NAND chip is using a
3513 - CONFIG_SYS_NDFC_EBC0_CFG
3514 Sets the EBC0_CFG register for the NDFC. If not defined
3515 a default value will be used.
3518 Get DDR timing information from an I2C EEPROM. Common
3519 with pluggable memory modules such as SODIMMs
3522 I2C address of the SPD EEPROM
3524 - CONFIG_SYS_SPD_BUS_NUM
3525 If SPD EEPROM is on an I2C bus other than the first
3526 one, specify here. Note that the value must resolve
3527 to something your driver can deal with.
3529 - CONFIG_SYS_DDR_RAW_TIMING
3530 Get DDR timing information from other than SPD. Common with
3531 soldered DDR chips onboard without SPD. DDR raw timing
3532 parameters are extracted from datasheet and hard-coded into
3533 header files or board specific files.
3535 - CONFIG_FSL_DDR_INTERACTIVE
3536 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3538 - CONFIG_SYS_83XX_DDR_USES_CS0
3539 Only for 83xx systems. If specified, then DDR should
3540 be configured using CS0 and CS1 instead of CS2 and CS3.
3542 - CONFIG_ETHER_ON_FEC[12]
3543 Define to enable FEC[12] on a 8xx series processor.
3545 - CONFIG_FEC[12]_PHY
3546 Define to the hardcoded PHY address which corresponds
3547 to the given FEC; i. e.
3548 #define CONFIG_FEC1_PHY 4
3549 means that the PHY with address 4 is connected to FEC1
3551 When set to -1, means to probe for first available.
3553 - CONFIG_FEC[12]_PHY_NORXERR
3554 The PHY does not have a RXERR line (RMII only).
3555 (so program the FEC to ignore it).
3558 Enable RMII mode for all FECs.
3559 Note that this is a global option, we can't
3560 have one FEC in standard MII mode and another in RMII mode.
3562 - CONFIG_CRC32_VERIFY
3563 Add a verify option to the crc32 command.
3566 => crc32 -v <address> <count> <crc32>
3568 Where address/count indicate a memory area
3569 and crc32 is the correct crc32 which the
3573 Add the "loopw" memory command. This only takes effect if
3574 the memory commands are activated globally (CONFIG_CMD_MEM).
3577 Add the "mdc" and "mwc" memory commands. These are cyclic
3582 This command will print 4 bytes (10,11,12,13) each 500 ms.
3584 => mwc.l 100 12345678 10
3585 This command will write 12345678 to address 100 all 10 ms.
3587 This only takes effect if the memory commands are activated
3588 globally (CONFIG_CMD_MEM).
3590 - CONFIG_SKIP_LOWLEVEL_INIT
3591 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3592 low level initializations (like setting up the memory
3593 controller) are omitted and/or U-Boot does not
3594 relocate itself into RAM.
3596 Normally this variable MUST NOT be defined. The only
3597 exception is when U-Boot is loaded (to RAM) by some
3598 other boot loader or by a debugger which performs
3599 these initializations itself.
3602 Modifies the behaviour of start.S when compiling a loader
3603 that is executed before the actual U-Boot. E.g. when
3604 compiling a NAND SPL.
3606 - CONFIG_USE_ARCH_MEMCPY
3607 CONFIG_USE_ARCH_MEMSET
3608 If these options are used a optimized version of memcpy/memset will
3609 be used if available. These functions may be faster under some
3610 conditions but may increase the binary size.
3612 Freescale QE/FMAN Firmware Support:
3613 -----------------------------------
3615 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3616 loading of "firmware", which is encoded in the QE firmware binary format.
3617 This firmware often needs to be loaded during U-Boot booting, so macros
3618 are used to identify the storage device (NOR flash, SPI, etc) and the address
3621 - CONFIG_SYS_QE_FMAN_FW_ADDR
3622 The address in the storage device where the firmware is located. The
3623 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3626 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3627 The maximum possible size of the firmware. The firmware binary format
3628 has a field that specifies the actual size of the firmware, but it
3629 might not be possible to read any part of the firmware unless some
3630 local storage is allocated to hold the entire firmware first.
3632 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3633 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3634 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3635 virtual address in NOR flash.
3637 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3638 Specifies that QE/FMAN firmware is located in NAND flash.
3639 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3641 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3642 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3643 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3645 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3646 Specifies that QE/FMAN firmware is located on the primary SPI
3647 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3649 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3650 Specifies that QE/FMAN firmware is located in the remote (master)
3651 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3652 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3653 window->master inbound window->master LAW->the ucode address in
3654 master's memory space.
3656 Building the Software:
3657 ======================
3659 Building U-Boot has been tested in several native build environments
3660 and in many different cross environments. Of course we cannot support
3661 all possibly existing versions of cross development tools in all
3662 (potentially obsolete) versions. In case of tool chain problems we
3663 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3664 which is extensively used to build and test U-Boot.
3666 If you are not using a native environment, it is assumed that you
3667 have GNU cross compiling tools available in your path. In this case,
3668 you must set the environment variable CROSS_COMPILE in your shell.
3669 Note that no changes to the Makefile or any other source files are
3670 necessary. For example using the ELDK on a 4xx CPU, please enter:
3672 $ CROSS_COMPILE=ppc_4xx-
3673 $ export CROSS_COMPILE
3675 Note: If you wish to generate Windows versions of the utilities in
3676 the tools directory you can use the MinGW toolchain
3677 (http://www.mingw.org). Set your HOST tools to the MinGW
3678 toolchain and execute 'make tools'. For example:
3680 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3682 Binaries such as tools/mkimage.exe will be created which can
3683 be executed on computers running Windows.
3685 U-Boot is intended to be simple to build. After installing the
3686 sources you must configure U-Boot for one specific board type. This
3691 where "NAME_config" is the name of one of the existing configu-
3692 rations; see boards.cfg for supported names.
3694 Note: for some board special configuration names may exist; check if
3695 additional information is available from the board vendor; for
3696 instance, the TQM823L systems are available without (standard)
3697 or with LCD support. You can select such additional "features"
3698 when choosing the configuration, i. e.
3701 - will configure for a plain TQM823L, i. e. no LCD support
3703 make TQM823L_LCD_config
3704 - will configure for a TQM823L with U-Boot console on LCD
3709 Finally, type "make all", and you should get some working U-Boot
3710 images ready for download to / installation on your system:
3712 - "u-boot.bin" is a raw binary image
3713 - "u-boot" is an image in ELF binary format
3714 - "u-boot.srec" is in Motorola S-Record format
3716 By default the build is performed locally and the objects are saved
3717 in the source directory. One of the two methods can be used to change
3718 this behavior and build U-Boot to some external directory:
3720 1. Add O= to the make command line invocations:
3722 make O=/tmp/build distclean
3723 make O=/tmp/build NAME_config
3724 make O=/tmp/build all
3726 2. Set environment variable BUILD_DIR to point to the desired location:
3728 export BUILD_DIR=/tmp/build
3733 Note that the command line "O=" setting overrides the BUILD_DIR environment
3737 Please be aware that the Makefiles assume you are using GNU make, so
3738 for instance on NetBSD you might need to use "gmake" instead of
3742 If the system board that you have is not listed, then you will need
3743 to port U-Boot to your hardware platform. To do this, follow these
3746 1. Add a new configuration option for your board to the toplevel
3747 "boards.cfg" file, using the existing entries as examples.
3748 Follow the instructions there to keep the boards in order.
3749 2. Create a new directory to hold your board specific code. Add any
3750 files you need. In your board directory, you will need at least
3751 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3752 3. Create a new configuration file "include/configs/<board>.h" for
3754 3. If you're porting U-Boot to a new CPU, then also create a new
3755 directory to hold your CPU specific code. Add any files you need.
3756 4. Run "make <board>_config" with your new name.
3757 5. Type "make", and you should get a working "u-boot.srec" file
3758 to be installed on your target system.
3759 6. Debug and solve any problems that might arise.
3760 [Of course, this last step is much harder than it sounds.]
3763 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3764 ==============================================================
3766 If you have modified U-Boot sources (for instance added a new board
3767 or support for new devices, a new CPU, etc.) you are expected to
3768 provide feedback to the other developers. The feedback normally takes
3769 the form of a "patch", i. e. a context diff against a certain (latest
3770 official or latest in the git repository) version of U-Boot sources.
3772 But before you submit such a patch, please verify that your modifi-
3773 cation did not break existing code. At least make sure that *ALL* of
3774 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3775 just run the "MAKEALL" script, which will configure and build U-Boot
3776 for ALL supported system. Be warned, this will take a while. You can
3777 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3778 environment variable to the script, i. e. to use the ELDK cross tools
3781 CROSS_COMPILE=ppc_8xx- MAKEALL
3783 or to build on a native PowerPC system you can type
3785 CROSS_COMPILE=' ' MAKEALL
3787 When using the MAKEALL script, the default behaviour is to build
3788 U-Boot in the source directory. This location can be changed by
3789 setting the BUILD_DIR environment variable. Also, for each target
3790 built, the MAKEALL script saves two log files (<target>.ERR and
3791 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3792 location can be changed by setting the MAKEALL_LOGDIR environment
3793 variable. For example:
3795 export BUILD_DIR=/tmp/build
3796 export MAKEALL_LOGDIR=/tmp/log
3797 CROSS_COMPILE=ppc_8xx- MAKEALL
3799 With the above settings build objects are saved in the /tmp/build,
3800 log files are saved in the /tmp/log and the source tree remains clean
3801 during the whole build process.
3804 See also "U-Boot Porting Guide" below.
3807 Monitor Commands - Overview:
3808 ============================
3810 go - start application at address 'addr'
3811 run - run commands in an environment variable
3812 bootm - boot application image from memory
3813 bootp - boot image via network using BootP/TFTP protocol
3814 bootz - boot zImage from memory
3815 tftpboot- boot image via network using TFTP protocol
3816 and env variables "ipaddr" and "serverip"
3817 (and eventually "gatewayip")
3818 tftpput - upload a file via network using TFTP protocol
3819 rarpboot- boot image via network using RARP/TFTP protocol
3820 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3821 loads - load S-Record file over serial line
3822 loadb - load binary file over serial line (kermit mode)
3824 mm - memory modify (auto-incrementing)
3825 nm - memory modify (constant address)
3826 mw - memory write (fill)
3828 cmp - memory compare
3829 crc32 - checksum calculation
3830 i2c - I2C sub-system
3831 sspi - SPI utility commands
3832 base - print or set address offset
3833 printenv- print environment variables
3834 setenv - set environment variables
3835 saveenv - save environment variables to persistent storage
3836 protect - enable or disable FLASH write protection
3837 erase - erase FLASH memory
3838 flinfo - print FLASH memory information
3839 bdinfo - print Board Info structure
3840 iminfo - print header information for application image
3841 coninfo - print console devices and informations
3842 ide - IDE sub-system
3843 loop - infinite loop on address range
3844 loopw - infinite write loop on address range
3845 mtest - simple RAM test
3846 icache - enable or disable instruction cache
3847 dcache - enable or disable data cache
3848 reset - Perform RESET of the CPU
3849 echo - echo args to console
3850 version - print monitor version
3851 help - print online help
3852 ? - alias for 'help'
3855 Monitor Commands - Detailed Description:
3856 ========================================
3860 For now: just type "help <command>".
3863 Environment Variables:
3864 ======================
3866 U-Boot supports user configuration using Environment Variables which
3867 can be made persistent by saving to Flash memory.
3869 Environment Variables are set using "setenv", printed using
3870 "printenv", and saved to Flash using "saveenv". Using "setenv"
3871 without a value can be used to delete a variable from the
3872 environment. As long as you don't save the environment you are
3873 working with an in-memory copy. In case the Flash area containing the
3874 environment is erased by accident, a default environment is provided.
3876 Some configuration options can be set using Environment Variables.
3878 List of environment variables (most likely not complete):
3880 baudrate - see CONFIG_BAUDRATE
3882 bootdelay - see CONFIG_BOOTDELAY
3884 bootcmd - see CONFIG_BOOTCOMMAND
3886 bootargs - Boot arguments when booting an RTOS image
3888 bootfile - Name of the image to load with TFTP
3890 bootm_low - Memory range available for image processing in the bootm
3891 command can be restricted. This variable is given as
3892 a hexadecimal number and defines lowest address allowed
3893 for use by the bootm command. See also "bootm_size"
3894 environment variable. Address defined by "bootm_low" is
3895 also the base of the initial memory mapping for the Linux
3896 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3899 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3900 This variable is given as a hexadecimal number and it
3901 defines the size of the memory region starting at base
3902 address bootm_low that is accessible by the Linux kernel
3903 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3904 as the default value if it is defined, and bootm_size is
3907 bootm_size - Memory range available for image processing in the bootm
3908 command can be restricted. This variable is given as
3909 a hexadecimal number and defines the size of the region
3910 allowed for use by the bootm command. See also "bootm_low"
3911 environment variable.
3913 updatefile - Location of the software update file on a TFTP server, used
3914 by the automatic software update feature. Please refer to
3915 documentation in doc/README.update for more details.
3917 autoload - if set to "no" (any string beginning with 'n'),
3918 "bootp" will just load perform a lookup of the
3919 configuration from the BOOTP server, but not try to
3920 load any image using TFTP
3922 autostart - if set to "yes", an image loaded using the "bootp",
3923 "rarpboot", "tftpboot" or "diskboot" commands will
3924 be automatically started (by internally calling
3927 If set to "no", a standalone image passed to the
3928 "bootm" command will be copied to the load address
3929 (and eventually uncompressed), but NOT be started.
3930 This can be used to load and uncompress arbitrary
3933 fdt_high - if set this restricts the maximum address that the
3934 flattened device tree will be copied into upon boot.
3935 For example, if you have a system with 1 GB memory
3936 at physical address 0x10000000, while Linux kernel
3937 only recognizes the first 704 MB as low memory, you
3938 may need to set fdt_high as 0x3C000000 to have the
3939 device tree blob be copied to the maximum address
3940 of the 704 MB low memory, so that Linux kernel can
3941 access it during the boot procedure.
3943 If this is set to the special value 0xFFFFFFFF then
3944 the fdt will not be copied at all on boot. For this
3945 to work it must reside in writable memory, have
3946 sufficient padding on the end of it for u-boot to
3947 add the information it needs into it, and the memory
3948 must be accessible by the kernel.
3950 fdtcontroladdr- if set this is the address of the control flattened
3951 device tree used by U-Boot when CONFIG_OF_CONTROL is
3954 i2cfast - (PPC405GP|PPC405EP only)
3955 if set to 'y' configures Linux I2C driver for fast
3956 mode (400kHZ). This environment variable is used in
3957 initialization code. So, for changes to be effective
3958 it must be saved and board must be reset.
3960 initrd_high - restrict positioning of initrd images:
3961 If this variable is not set, initrd images will be
3962 copied to the highest possible address in RAM; this
3963 is usually what you want since it allows for
3964 maximum initrd size. If for some reason you want to
3965 make sure that the initrd image is loaded below the
3966 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3967 variable to a value of "no" or "off" or "0".
3968 Alternatively, you can set it to a maximum upper
3969 address to use (U-Boot will still check that it
3970 does not overwrite the U-Boot stack and data).
3972 For instance, when you have a system with 16 MB
3973 RAM, and want to reserve 4 MB from use by Linux,
3974 you can do this by adding "mem=12M" to the value of
3975 the "bootargs" variable. However, now you must make
3976 sure that the initrd image is placed in the first
3977 12 MB as well - this can be done with
3979 setenv initrd_high 00c00000
3981 If you set initrd_high to 0xFFFFFFFF, this is an
3982 indication to U-Boot that all addresses are legal
3983 for the Linux kernel, including addresses in flash
3984 memory. In this case U-Boot will NOT COPY the
3985 ramdisk at all. This may be useful to reduce the
3986 boot time on your system, but requires that this
3987 feature is supported by your Linux kernel.
3989 ipaddr - IP address; needed for tftpboot command
3991 loadaddr - Default load address for commands like "bootp",
3992 "rarpboot", "tftpboot", "loadb" or "diskboot"
3994 loads_echo - see CONFIG_LOADS_ECHO
3996 serverip - TFTP server IP address; needed for tftpboot command
3998 bootretry - see CONFIG_BOOT_RETRY_TIME
4000 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4002 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4004 ethprime - controls which interface is used first.
4006 ethact - controls which interface is currently active.
4007 For example you can do the following
4009 => setenv ethact FEC
4010 => ping 192.168.0.1 # traffic sent on FEC
4011 => setenv ethact SCC
4012 => ping 10.0.0.1 # traffic sent on SCC
4014 ethrotate - When set to "no" U-Boot does not go through all
4015 available network interfaces.
4016 It just stays at the currently selected interface.
4018 netretry - When set to "no" each network operation will
4019 either succeed or fail without retrying.
4020 When set to "once" the network operation will
4021 fail when all the available network interfaces
4022 are tried once without success.
4023 Useful on scripts which control the retry operation
4026 npe_ucode - set load address for the NPE microcode
4028 tftpsrcport - If this is set, the value is used for TFTP's
4031 tftpdstport - If this is set, the value is used for TFTP's UDP
4032 destination port instead of the Well Know Port 69.
4034 tftpblocksize - Block size to use for TFTP transfers; if not set,
4035 we use the TFTP server's default block size
4037 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4038 seconds, minimum value is 1000 = 1 second). Defines
4039 when a packet is considered to be lost so it has to
4040 be retransmitted. The default is 5000 = 5 seconds.
4041 Lowering this value may make downloads succeed
4042 faster in networks with high packet loss rates or
4043 with unreliable TFTP servers.
4045 vlan - When set to a value < 4095 the traffic over
4046 Ethernet is encapsulated/received over 802.1q
4049 The following image location variables contain the location of images
4050 used in booting. The "Image" column gives the role of the image and is
4051 not an environment variable name. The other columns are environment
4052 variable names. "File Name" gives the name of the file on a TFTP
4053 server, "RAM Address" gives the location in RAM the image will be
4054 loaded to, and "Flash Location" gives the image's address in NOR
4055 flash or offset in NAND flash.
4057 *Note* - these variables don't have to be defined for all boards, some
4058 boards currenlty use other variables for these purposes, and some
4059 boards use these variables for other purposes.
4061 Image File Name RAM Address Flash Location
4062 ----- --------- ----------- --------------
4063 u-boot u-boot u-boot_addr_r u-boot_addr
4064 Linux kernel bootfile kernel_addr_r kernel_addr
4065 device tree blob fdtfile fdt_addr_r fdt_addr
4066 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4068 The following environment variables may be used and automatically
4069 updated by the network boot commands ("bootp" and "rarpboot"),
4070 depending the information provided by your boot server:
4072 bootfile - see above
4073 dnsip - IP address of your Domain Name Server
4074 dnsip2 - IP address of your secondary Domain Name Server
4075 gatewayip - IP address of the Gateway (Router) to use
4076 hostname - Target hostname
4078 netmask - Subnet Mask
4079 rootpath - Pathname of the root filesystem on the NFS server
4080 serverip - see above
4083 There are two special Environment Variables:
4085 serial# - contains hardware identification information such
4086 as type string and/or serial number
4087 ethaddr - Ethernet address
4089 These variables can be set only once (usually during manufacturing of
4090 the board). U-Boot refuses to delete or overwrite these variables
4091 once they have been set once.
4094 Further special Environment Variables:
4096 ver - Contains the U-Boot version string as printed
4097 with the "version" command. This variable is
4098 readonly (see CONFIG_VERSION_VARIABLE).
4101 Please note that changes to some configuration parameters may take
4102 only effect after the next boot (yes, that's just like Windoze :-).
4105 Command Line Parsing:
4106 =====================
4108 There are two different command line parsers available with U-Boot:
4109 the old "simple" one, and the much more powerful "hush" shell:
4111 Old, simple command line parser:
4112 --------------------------------
4114 - supports environment variables (through setenv / saveenv commands)
4115 - several commands on one line, separated by ';'
4116 - variable substitution using "... ${name} ..." syntax
4117 - special characters ('$', ';') can be escaped by prefixing with '\',
4119 setenv bootcmd bootm \${address}
4120 - You can also escape text by enclosing in single apostrophes, for example:
4121 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4126 - similar to Bourne shell, with control structures like
4127 if...then...else...fi, for...do...done; while...do...done,
4128 until...do...done, ...
4129 - supports environment ("global") variables (through setenv / saveenv
4130 commands) and local shell variables (through standard shell syntax
4131 "name=value"); only environment variables can be used with "run"
4137 (1) If a command line (or an environment variable executed by a "run"
4138 command) contains several commands separated by semicolon, and
4139 one of these commands fails, then the remaining commands will be
4142 (2) If you execute several variables with one call to run (i. e.
4143 calling run with a list of variables as arguments), any failing
4144 command will cause "run" to terminate, i. e. the remaining
4145 variables are not executed.
4147 Note for Redundant Ethernet Interfaces:
4148 =======================================
4150 Some boards come with redundant Ethernet interfaces; U-Boot supports
4151 such configurations and is capable of automatic selection of a
4152 "working" interface when needed. MAC assignment works as follows:
4154 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4155 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4156 "eth1addr" (=>eth1), "eth2addr", ...
4158 If the network interface stores some valid MAC address (for instance
4159 in SROM), this is used as default address if there is NO correspon-
4160 ding setting in the environment; if the corresponding environment
4161 variable is set, this overrides the settings in the card; that means:
4163 o If the SROM has a valid MAC address, and there is no address in the
4164 environment, the SROM's address is used.
4166 o If there is no valid address in the SROM, and a definition in the
4167 environment exists, then the value from the environment variable is
4170 o If both the SROM and the environment contain a MAC address, and
4171 both addresses are the same, this MAC address is used.
4173 o If both the SROM and the environment contain a MAC address, and the
4174 addresses differ, the value from the environment is used and a
4177 o If neither SROM nor the environment contain a MAC address, an error
4180 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4181 will be programmed into hardware as part of the initialization process. This
4182 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4183 The naming convention is as follows:
4184 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4189 U-Boot is capable of booting (and performing other auxiliary operations on)
4190 images in two formats:
4192 New uImage format (FIT)
4193 -----------------------
4195 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4196 to Flattened Device Tree). It allows the use of images with multiple
4197 components (several kernels, ramdisks, etc.), with contents protected by
4198 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4204 Old image format is based on binary files which can be basically anything,
4205 preceded by a special header; see the definitions in include/image.h for
4206 details; basically, the header defines the following image properties:
4208 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4209 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4210 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4211 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4213 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4214 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4215 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4216 * Compression Type (uncompressed, gzip, bzip2)
4222 The header is marked by a special Magic Number, and both the header
4223 and the data portions of the image are secured against corruption by
4230 Although U-Boot should support any OS or standalone application
4231 easily, the main focus has always been on Linux during the design of
4234 U-Boot includes many features that so far have been part of some
4235 special "boot loader" code within the Linux kernel. Also, any
4236 "initrd" images to be used are no longer part of one big Linux image;
4237 instead, kernel and "initrd" are separate images. This implementation
4238 serves several purposes:
4240 - the same features can be used for other OS or standalone
4241 applications (for instance: using compressed images to reduce the
4242 Flash memory footprint)
4244 - it becomes much easier to port new Linux kernel versions because
4245 lots of low-level, hardware dependent stuff are done by U-Boot
4247 - the same Linux kernel image can now be used with different "initrd"
4248 images; of course this also means that different kernel images can
4249 be run with the same "initrd". This makes testing easier (you don't
4250 have to build a new "zImage.initrd" Linux image when you just
4251 change a file in your "initrd"). Also, a field-upgrade of the
4252 software is easier now.
4258 Porting Linux to U-Boot based systems:
4259 ---------------------------------------
4261 U-Boot cannot save you from doing all the necessary modifications to
4262 configure the Linux device drivers for use with your target hardware
4263 (no, we don't intend to provide a full virtual machine interface to
4266 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4268 Just make sure your machine specific header file (for instance
4269 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4270 Information structure as we define in include/asm-<arch>/u-boot.h,
4271 and make sure that your definition of IMAP_ADDR uses the same value
4272 as your U-Boot configuration in CONFIG_SYS_IMMR.
4275 Configuring the Linux kernel:
4276 -----------------------------
4278 No specific requirements for U-Boot. Make sure you have some root
4279 device (initial ramdisk, NFS) for your target system.
4282 Building a Linux Image:
4283 -----------------------
4285 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4286 not used. If you use recent kernel source, a new build target
4287 "uImage" will exist which automatically builds an image usable by
4288 U-Boot. Most older kernels also have support for a "pImage" target,
4289 which was introduced for our predecessor project PPCBoot and uses a
4290 100% compatible format.
4299 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4300 encapsulate a compressed Linux kernel image with header information,
4301 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4303 * build a standard "vmlinux" kernel image (in ELF binary format):
4305 * convert the kernel into a raw binary image:
4307 ${CROSS_COMPILE}-objcopy -O binary \
4308 -R .note -R .comment \
4309 -S vmlinux linux.bin
4311 * compress the binary image:
4315 * package compressed binary image for U-Boot:
4317 mkimage -A ppc -O linux -T kernel -C gzip \
4318 -a 0 -e 0 -n "Linux Kernel Image" \
4319 -d linux.bin.gz uImage
4322 The "mkimage" tool can also be used to create ramdisk images for use
4323 with U-Boot, either separated from the Linux kernel image, or
4324 combined into one file. "mkimage" encapsulates the images with a 64
4325 byte header containing information about target architecture,
4326 operating system, image type, compression method, entry points, time
4327 stamp, CRC32 checksums, etc.
4329 "mkimage" can be called in two ways: to verify existing images and
4330 print the header information, or to build new images.
4332 In the first form (with "-l" option) mkimage lists the information
4333 contained in the header of an existing U-Boot image; this includes
4334 checksum verification:
4336 tools/mkimage -l image
4337 -l ==> list image header information
4339 The second form (with "-d" option) is used to build a U-Boot image
4340 from a "data file" which is used as image payload:
4342 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4343 -n name -d data_file image
4344 -A ==> set architecture to 'arch'
4345 -O ==> set operating system to 'os'
4346 -T ==> set image type to 'type'
4347 -C ==> set compression type 'comp'
4348 -a ==> set load address to 'addr' (hex)
4349 -e ==> set entry point to 'ep' (hex)
4350 -n ==> set image name to 'name'
4351 -d ==> use image data from 'datafile'
4353 Right now, all Linux kernels for PowerPC systems use the same load
4354 address (0x00000000), but the entry point address depends on the
4357 - 2.2.x kernels have the entry point at 0x0000000C,
4358 - 2.3.x and later kernels have the entry point at 0x00000000.
4360 So a typical call to build a U-Boot image would read:
4362 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4363 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4364 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4365 > examples/uImage.TQM850L
4366 Image Name: 2.4.4 kernel for TQM850L
4367 Created: Wed Jul 19 02:34:59 2000
4368 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4369 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4370 Load Address: 0x00000000
4371 Entry Point: 0x00000000
4373 To verify the contents of the image (or check for corruption):
4375 -> tools/mkimage -l examples/uImage.TQM850L
4376 Image Name: 2.4.4 kernel for TQM850L
4377 Created: Wed Jul 19 02:34:59 2000
4378 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4379 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4380 Load Address: 0x00000000
4381 Entry Point: 0x00000000
4383 NOTE: for embedded systems where boot time is critical you can trade
4384 speed for memory and install an UNCOMPRESSED image instead: this
4385 needs more space in Flash, but boots much faster since it does not
4386 need to be uncompressed:
4388 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4389 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4390 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4391 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4392 > examples/uImage.TQM850L-uncompressed
4393 Image Name: 2.4.4 kernel for TQM850L
4394 Created: Wed Jul 19 02:34:59 2000
4395 Image Type: PowerPC Linux Kernel Image (uncompressed)
4396 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4397 Load Address: 0x00000000
4398 Entry Point: 0x00000000
4401 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4402 when your kernel is intended to use an initial ramdisk:
4404 -> tools/mkimage -n 'Simple Ramdisk Image' \
4405 > -A ppc -O linux -T ramdisk -C gzip \
4406 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4407 Image Name: Simple Ramdisk Image
4408 Created: Wed Jan 12 14:01:50 2000
4409 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4410 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4411 Load Address: 0x00000000
4412 Entry Point: 0x00000000
4415 Installing a Linux Image:
4416 -------------------------
4418 To downloading a U-Boot image over the serial (console) interface,
4419 you must convert the image to S-Record format:
4421 objcopy -I binary -O srec examples/image examples/image.srec
4423 The 'objcopy' does not understand the information in the U-Boot
4424 image header, so the resulting S-Record file will be relative to
4425 address 0x00000000. To load it to a given address, you need to
4426 specify the target address as 'offset' parameter with the 'loads'
4429 Example: install the image to address 0x40100000 (which on the
4430 TQM8xxL is in the first Flash bank):
4432 => erase 40100000 401FFFFF
4438 ## Ready for S-Record download ...
4439 ~>examples/image.srec
4440 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4442 15989 15990 15991 15992
4443 [file transfer complete]
4445 ## Start Addr = 0x00000000
4448 You can check the success of the download using the 'iminfo' command;
4449 this includes a checksum verification so you can be sure no data
4450 corruption happened:
4454 ## Checking Image at 40100000 ...
4455 Image Name: 2.2.13 for initrd on TQM850L
4456 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4457 Data Size: 335725 Bytes = 327 kB = 0 MB
4458 Load Address: 00000000
4459 Entry Point: 0000000c
4460 Verifying Checksum ... OK
4466 The "bootm" command is used to boot an application that is stored in
4467 memory (RAM or Flash). In case of a Linux kernel image, the contents
4468 of the "bootargs" environment variable is passed to the kernel as
4469 parameters. You can check and modify this variable using the
4470 "printenv" and "setenv" commands:
4473 => printenv bootargs
4474 bootargs=root=/dev/ram
4476 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4478 => printenv bootargs
4479 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4482 ## Booting Linux kernel at 40020000 ...
4483 Image Name: 2.2.13 for NFS on TQM850L
4484 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4485 Data Size: 381681 Bytes = 372 kB = 0 MB
4486 Load Address: 00000000
4487 Entry Point: 0000000c
4488 Verifying Checksum ... OK
4489 Uncompressing Kernel Image ... OK
4490 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
4491 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4492 time_init: decrementer frequency = 187500000/60
4493 Calibrating delay loop... 49.77 BogoMIPS
4494 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4497 If you want to boot a Linux kernel with initial RAM disk, you pass
4498 the memory addresses of both the kernel and the initrd image (PPBCOOT
4499 format!) to the "bootm" command:
4501 => imi 40100000 40200000
4503 ## Checking Image at 40100000 ...
4504 Image Name: 2.2.13 for initrd on TQM850L
4505 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4506 Data Size: 335725 Bytes = 327 kB = 0 MB
4507 Load Address: 00000000
4508 Entry Point: 0000000c
4509 Verifying Checksum ... OK
4511 ## Checking Image at 40200000 ...
4512 Image Name: Simple Ramdisk Image
4513 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4514 Data Size: 566530 Bytes = 553 kB = 0 MB
4515 Load Address: 00000000
4516 Entry Point: 00000000
4517 Verifying Checksum ... OK
4519 => bootm 40100000 40200000
4520 ## Booting Linux kernel at 40100000 ...
4521 Image Name: 2.2.13 for initrd on TQM850L
4522 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4523 Data Size: 335725 Bytes = 327 kB = 0 MB
4524 Load Address: 00000000
4525 Entry Point: 0000000c
4526 Verifying Checksum ... OK
4527 Uncompressing Kernel Image ... OK
4528 ## Loading RAMDisk Image at 40200000 ...
4529 Image Name: Simple Ramdisk Image
4530 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4531 Data Size: 566530 Bytes = 553 kB = 0 MB
4532 Load Address: 00000000
4533 Entry Point: 00000000
4534 Verifying Checksum ... OK
4535 Loading Ramdisk ... OK
4536 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
4537 Boot arguments: root=/dev/ram
4538 time_init: decrementer frequency = 187500000/60
4539 Calibrating delay loop... 49.77 BogoMIPS
4541 RAMDISK: Compressed image found at block 0
4542 VFS: Mounted root (ext2 filesystem).
4546 Boot Linux and pass a flat device tree:
4549 First, U-Boot must be compiled with the appropriate defines. See the section
4550 titled "Linux Kernel Interface" above for a more in depth explanation. The
4551 following is an example of how to start a kernel and pass an updated
4557 oft=oftrees/mpc8540ads.dtb
4558 => tftp $oftaddr $oft
4559 Speed: 1000, full duplex
4561 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4562 Filename 'oftrees/mpc8540ads.dtb'.
4563 Load address: 0x300000
4566 Bytes transferred = 4106 (100a hex)
4567 => tftp $loadaddr $bootfile
4568 Speed: 1000, full duplex
4570 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4572 Load address: 0x200000
4573 Loading:############
4575 Bytes transferred = 1029407 (fb51f hex)
4580 => bootm $loadaddr - $oftaddr
4581 ## Booting image at 00200000 ...
4582 Image Name: Linux-2.6.17-dirty
4583 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4584 Data Size: 1029343 Bytes = 1005.2 kB
4585 Load Address: 00000000
4586 Entry Point: 00000000
4587 Verifying Checksum ... OK
4588 Uncompressing Kernel Image ... OK
4589 Booting using flat device tree at 0x300000
4590 Using MPC85xx ADS machine description
4591 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4595 More About U-Boot Image Types:
4596 ------------------------------
4598 U-Boot supports the following image types:
4600 "Standalone Programs" are directly runnable in the environment
4601 provided by U-Boot; it is expected that (if they behave
4602 well) you can continue to work in U-Boot after return from
4603 the Standalone Program.
4604 "OS Kernel Images" are usually images of some Embedded OS which
4605 will take over control completely. Usually these programs
4606 will install their own set of exception handlers, device
4607 drivers, set up the MMU, etc. - this means, that you cannot
4608 expect to re-enter U-Boot except by resetting the CPU.
4609 "RAMDisk Images" are more or less just data blocks, and their
4610 parameters (address, size) are passed to an OS kernel that is
4612 "Multi-File Images" contain several images, typically an OS
4613 (Linux) kernel image and one or more data images like
4614 RAMDisks. This construct is useful for instance when you want
4615 to boot over the network using BOOTP etc., where the boot
4616 server provides just a single image file, but you want to get
4617 for instance an OS kernel and a RAMDisk image.
4619 "Multi-File Images" start with a list of image sizes, each
4620 image size (in bytes) specified by an "uint32_t" in network
4621 byte order. This list is terminated by an "(uint32_t)0".
4622 Immediately after the terminating 0 follow the images, one by
4623 one, all aligned on "uint32_t" boundaries (size rounded up to
4624 a multiple of 4 bytes).
4626 "Firmware Images" are binary images containing firmware (like
4627 U-Boot or FPGA images) which usually will be programmed to
4630 "Script files" are command sequences that will be executed by
4631 U-Boot's command interpreter; this feature is especially
4632 useful when you configure U-Boot to use a real shell (hush)
4633 as command interpreter.
4635 Booting the Linux zImage:
4636 -------------------------
4638 On some platforms, it's possible to boot Linux zImage. This is done
4639 using the "bootz" command. The syntax of "bootz" command is the same
4640 as the syntax of "bootm" command.
4642 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4643 kernel with raw initrd images. The syntax is slightly different, the
4644 address of the initrd must be augmented by it's size, in the following
4645 format: "<initrd addres>:<initrd size>".
4651 One of the features of U-Boot is that you can dynamically load and
4652 run "standalone" applications, which can use some resources of
4653 U-Boot like console I/O functions or interrupt services.
4655 Two simple examples are included with the sources:
4660 'examples/hello_world.c' contains a small "Hello World" Demo
4661 application; it is automatically compiled when you build U-Boot.
4662 It's configured to run at address 0x00040004, so you can play with it
4666 ## Ready for S-Record download ...
4667 ~>examples/hello_world.srec
4668 1 2 3 4 5 6 7 8 9 10 11 ...
4669 [file transfer complete]
4671 ## Start Addr = 0x00040004
4673 => go 40004 Hello World! This is a test.
4674 ## Starting application at 0x00040004 ...
4685 Hit any key to exit ...
4687 ## Application terminated, rc = 0x0
4689 Another example, which demonstrates how to register a CPM interrupt
4690 handler with the U-Boot code, can be found in 'examples/timer.c'.
4691 Here, a CPM timer is set up to generate an interrupt every second.
4692 The interrupt service routine is trivial, just printing a '.'
4693 character, but this is just a demo program. The application can be
4694 controlled by the following keys:
4696 ? - print current values og the CPM Timer registers
4697 b - enable interrupts and start timer
4698 e - stop timer and disable interrupts
4699 q - quit application
4702 ## Ready for S-Record download ...
4703 ~>examples/timer.srec
4704 1 2 3 4 5 6 7 8 9 10 11 ...
4705 [file transfer complete]
4707 ## Start Addr = 0x00040004
4710 ## Starting application at 0x00040004 ...
4713 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4716 [q, b, e, ?] Set interval 1000000 us
4719 [q, b, e, ?] ........
4720 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4723 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4726 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4729 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4731 [q, b, e, ?] ...Stopping timer
4733 [q, b, e, ?] ## Application terminated, rc = 0x0
4739 Over time, many people have reported problems when trying to use the
4740 "minicom" terminal emulation program for serial download. I (wd)
4741 consider minicom to be broken, and recommend not to use it. Under
4742 Unix, I recommend to use C-Kermit for general purpose use (and
4743 especially for kermit binary protocol download ("loadb" command), and
4744 use "cu" for S-Record download ("loads" command). See
4745 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4746 for help with kermit.
4749 Nevertheless, if you absolutely want to use it try adding this
4750 configuration to your "File transfer protocols" section:
4752 Name Program Name U/D FullScr IO-Red. Multi
4753 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4754 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4760 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4761 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4763 Building requires a cross environment; it is known to work on
4764 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4765 need gmake since the Makefiles are not compatible with BSD make).
4766 Note that the cross-powerpc package does not install include files;
4767 attempting to build U-Boot will fail because <machine/ansi.h> is
4768 missing. This file has to be installed and patched manually:
4770 # cd /usr/pkg/cross/powerpc-netbsd/include
4772 # ln -s powerpc machine
4773 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4774 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4776 Native builds *don't* work due to incompatibilities between native
4777 and U-Boot include files.
4779 Booting assumes that (the first part of) the image booted is a
4780 stage-2 loader which in turn loads and then invokes the kernel
4781 proper. Loader sources will eventually appear in the NetBSD source
4782 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4783 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4786 Implementation Internals:
4787 =========================
4789 The following is not intended to be a complete description of every
4790 implementation detail. However, it should help to understand the
4791 inner workings of U-Boot and make it easier to port it to custom
4795 Initial Stack, Global Data:
4796 ---------------------------
4798 The implementation of U-Boot is complicated by the fact that U-Boot
4799 starts running out of ROM (flash memory), usually without access to
4800 system RAM (because the memory controller is not initialized yet).
4801 This means that we don't have writable Data or BSS segments, and BSS
4802 is not initialized as zero. To be able to get a C environment working
4803 at all, we have to allocate at least a minimal stack. Implementation
4804 options for this are defined and restricted by the CPU used: Some CPU
4805 models provide on-chip memory (like the IMMR area on MPC8xx and
4806 MPC826x processors), on others (parts of) the data cache can be
4807 locked as (mis-) used as memory, etc.
4809 Chris Hallinan posted a good summary of these issues to the
4810 U-Boot mailing list:
4812 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4813 From: "Chris Hallinan" <clh@net1plus.com>
4814 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4817 Correct me if I'm wrong, folks, but the way I understand it
4818 is this: Using DCACHE as initial RAM for Stack, etc, does not
4819 require any physical RAM backing up the cache. The cleverness
4820 is that the cache is being used as a temporary supply of
4821 necessary storage before the SDRAM controller is setup. It's
4822 beyond the scope of this list to explain the details, but you
4823 can see how this works by studying the cache architecture and
4824 operation in the architecture and processor-specific manuals.
4826 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4827 is another option for the system designer to use as an
4828 initial stack/RAM area prior to SDRAM being available. Either
4829 option should work for you. Using CS 4 should be fine if your
4830 board designers haven't used it for something that would
4831 cause you grief during the initial boot! It is frequently not
4834 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4835 with your processor/board/system design. The default value
4836 you will find in any recent u-boot distribution in
4837 walnut.h should work for you. I'd set it to a value larger
4838 than your SDRAM module. If you have a 64MB SDRAM module, set
4839 it above 400_0000. Just make sure your board has no resources
4840 that are supposed to respond to that address! That code in
4841 start.S has been around a while and should work as is when
4842 you get the config right.
4847 It is essential to remember this, since it has some impact on the C
4848 code for the initialization procedures:
4850 * Initialized global data (data segment) is read-only. Do not attempt
4853 * Do not use any uninitialized global data (or implicitely initialized
4854 as zero data - BSS segment) at all - this is undefined, initiali-
4855 zation is performed later (when relocating to RAM).
4857 * Stack space is very limited. Avoid big data buffers or things like
4860 Having only the stack as writable memory limits means we cannot use
4861 normal global data to share information beween the code. But it
4862 turned out that the implementation of U-Boot can be greatly
4863 simplified by making a global data structure (gd_t) available to all
4864 functions. We could pass a pointer to this data as argument to _all_
4865 functions, but this would bloat the code. Instead we use a feature of
4866 the GCC compiler (Global Register Variables) to share the data: we
4867 place a pointer (gd) to the global data into a register which we
4868 reserve for this purpose.
4870 When choosing a register for such a purpose we are restricted by the
4871 relevant (E)ABI specifications for the current architecture, and by
4872 GCC's implementation.
4874 For PowerPC, the following registers have specific use:
4876 R2: reserved for system use
4877 R3-R4: parameter passing and return values
4878 R5-R10: parameter passing
4879 R13: small data area pointer
4883 (U-Boot also uses R12 as internal GOT pointer. r12
4884 is a volatile register so r12 needs to be reset when
4885 going back and forth between asm and C)
4887 ==> U-Boot will use R2 to hold a pointer to the global data
4889 Note: on PPC, we could use a static initializer (since the
4890 address of the global data structure is known at compile time),
4891 but it turned out that reserving a register results in somewhat
4892 smaller code - although the code savings are not that big (on
4893 average for all boards 752 bytes for the whole U-Boot image,
4894 624 text + 127 data).
4896 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4897 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4899 ==> U-Boot will use P3 to hold a pointer to the global data
4901 On ARM, the following registers are used:
4903 R0: function argument word/integer result
4904 R1-R3: function argument word
4906 R10: stack limit (used only if stack checking if enabled)
4907 R11: argument (frame) pointer
4908 R12: temporary workspace
4911 R15: program counter
4913 ==> U-Boot will use R8 to hold a pointer to the global data
4915 On Nios II, the ABI is documented here:
4916 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4918 ==> U-Boot will use gp to hold a pointer to the global data
4920 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4921 to access small data sections, so gp is free.
4923 On NDS32, the following registers are used:
4925 R0-R1: argument/return
4927 R15: temporary register for assembler
4928 R16: trampoline register
4929 R28: frame pointer (FP)
4930 R29: global pointer (GP)
4931 R30: link register (LP)
4932 R31: stack pointer (SP)
4933 PC: program counter (PC)
4935 ==> U-Boot will use R10 to hold a pointer to the global data
4937 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4938 or current versions of GCC may "optimize" the code too much.
4943 U-Boot runs in system state and uses physical addresses, i.e. the
4944 MMU is not used either for address mapping nor for memory protection.
4946 The available memory is mapped to fixed addresses using the memory
4947 controller. In this process, a contiguous block is formed for each
4948 memory type (Flash, SDRAM, SRAM), even when it consists of several
4949 physical memory banks.
4951 U-Boot is installed in the first 128 kB of the first Flash bank (on
4952 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4953 booting and sizing and initializing DRAM, the code relocates itself
4954 to the upper end of DRAM. Immediately below the U-Boot code some
4955 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4956 configuration setting]. Below that, a structure with global Board
4957 Info data is placed, followed by the stack (growing downward).
4959 Additionally, some exception handler code is copied to the low 8 kB
4960 of DRAM (0x00000000 ... 0x00001FFF).
4962 So a typical memory configuration with 16 MB of DRAM could look like
4965 0x0000 0000 Exception Vector code
4968 0x0000 2000 Free for Application Use
4974 0x00FB FF20 Monitor Stack (Growing downward)
4975 0x00FB FFAC Board Info Data and permanent copy of global data
4976 0x00FC 0000 Malloc Arena
4979 0x00FE 0000 RAM Copy of Monitor Code
4980 ... eventually: LCD or video framebuffer
4981 ... eventually: pRAM (Protected RAM - unchanged by reset)
4982 0x00FF FFFF [End of RAM]
4985 System Initialization:
4986 ----------------------
4988 In the reset configuration, U-Boot starts at the reset entry point
4989 (on most PowerPC systems at address 0x00000100). Because of the reset
4990 configuration for CS0# this is a mirror of the onboard Flash memory.
4991 To be able to re-map memory U-Boot then jumps to its link address.
4992 To be able to implement the initialization code in C, a (small!)
4993 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4994 which provide such a feature like MPC8xx or MPC8260), or in a locked
4995 part of the data cache. After that, U-Boot initializes the CPU core,
4996 the caches and the SIU.
4998 Next, all (potentially) available memory banks are mapped using a
4999 preliminary mapping. For example, we put them on 512 MB boundaries
5000 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5001 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5002 programmed for SDRAM access. Using the temporary configuration, a
5003 simple memory test is run that determines the size of the SDRAM
5006 When there is more than one SDRAM bank, and the banks are of
5007 different size, the largest is mapped first. For equal size, the first
5008 bank (CS2#) is mapped first. The first mapping is always for address
5009 0x00000000, with any additional banks following immediately to create
5010 contiguous memory starting from 0.
5012 Then, the monitor installs itself at the upper end of the SDRAM area
5013 and allocates memory for use by malloc() and for the global Board
5014 Info data; also, the exception vector code is copied to the low RAM
5015 pages, and the final stack is set up.
5017 Only after this relocation will you have a "normal" C environment;
5018 until that you are restricted in several ways, mostly because you are
5019 running from ROM, and because the code will have to be relocated to a
5023 U-Boot Porting Guide:
5024 ----------------------
5026 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5030 int main(int argc, char *argv[])
5032 sighandler_t no_more_time;
5034 signal(SIGALRM, no_more_time);
5035 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5037 if (available_money > available_manpower) {
5038 Pay consultant to port U-Boot;
5042 Download latest U-Boot source;
5044 Subscribe to u-boot mailing list;
5047 email("Hi, I am new to U-Boot, how do I get started?");
5050 Read the README file in the top level directory;
5051 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5052 Read applicable doc/*.README;
5053 Read the source, Luke;
5054 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5057 if (available_money > toLocalCurrency ($2500))
5060 Add a lot of aggravation and time;
5062 if (a similar board exists) { /* hopefully... */
5063 cp -a board/<similar> board/<myboard>
5064 cp include/configs/<similar>.h include/configs/<myboard>.h
5066 Create your own board support subdirectory;
5067 Create your own board include/configs/<myboard>.h file;
5069 Edit new board/<myboard> files
5070 Edit new include/configs/<myboard>.h
5075 Add / modify source code;
5079 email("Hi, I am having problems...");
5081 Send patch file to the U-Boot email list;
5082 if (reasonable critiques)
5083 Incorporate improvements from email list code review;
5085 Defend code as written;
5091 void no_more_time (int sig)
5100 All contributions to U-Boot should conform to the Linux kernel
5101 coding style; see the file "Documentation/CodingStyle" and the script
5102 "scripts/Lindent" in your Linux kernel source directory.
5104 Source files originating from a different project (for example the
5105 MTD subsystem) are generally exempt from these guidelines and are not
5106 reformated to ease subsequent migration to newer versions of those
5109 Please note that U-Boot is implemented in C (and to some small parts in
5110 Assembler); no C++ is used, so please do not use C++ style comments (//)
5113 Please also stick to the following formatting rules:
5114 - remove any trailing white space
5115 - use TAB characters for indentation and vertical alignment, not spaces
5116 - make sure NOT to use DOS '\r\n' line feeds
5117 - do not add more than 2 consecutive empty lines to source files
5118 - do not add trailing empty lines to source files
5120 Submissions which do not conform to the standards may be returned
5121 with a request to reformat the changes.
5127 Since the number of patches for U-Boot is growing, we need to
5128 establish some rules. Submissions which do not conform to these rules
5129 may be rejected, even when they contain important and valuable stuff.
5131 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5133 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5134 see http://lists.denx.de/mailman/listinfo/u-boot
5136 When you send a patch, please include the following information with
5139 * For bug fixes: a description of the bug and how your patch fixes
5140 this bug. Please try to include a way of demonstrating that the
5141 patch actually fixes something.
5143 * For new features: a description of the feature and your
5146 * A CHANGELOG entry as plaintext (separate from the patch)
5148 * For major contributions, your entry to the CREDITS file
5150 * When you add support for a new board, don't forget to add this
5151 board to the MAINTAINERS file, too.
5153 * If your patch adds new configuration options, don't forget to
5154 document these in the README file.
5156 * The patch itself. If you are using git (which is *strongly*
5157 recommended) you can easily generate the patch using the
5158 "git format-patch". If you then use "git send-email" to send it to
5159 the U-Boot mailing list, you will avoid most of the common problems
5160 with some other mail clients.
5162 If you cannot use git, use "diff -purN OLD NEW". If your version of
5163 diff does not support these options, then get the latest version of
5166 The current directory when running this command shall be the parent
5167 directory of the U-Boot source tree (i. e. please make sure that
5168 your patch includes sufficient directory information for the
5171 We prefer patches as plain text. MIME attachments are discouraged,
5172 and compressed attachments must not be used.
5174 * If one logical set of modifications affects or creates several
5175 files, all these changes shall be submitted in a SINGLE patch file.
5177 * Changesets that contain different, unrelated modifications shall be
5178 submitted as SEPARATE patches, one patch per changeset.
5183 * Before sending the patch, run the MAKEALL script on your patched
5184 source tree and make sure that no errors or warnings are reported
5185 for any of the boards.
5187 * Keep your modifications to the necessary minimum: A patch
5188 containing several unrelated changes or arbitrary reformats will be
5189 returned with a request to re-formatting / split it.
5191 * If you modify existing code, make sure that your new code does not
5192 add to the memory footprint of the code ;-) Small is beautiful!
5193 When adding new features, these should compile conditionally only
5194 (using #ifdef), and the resulting code with the new feature
5195 disabled must not need more memory than the old code without your
5198 * Remember that there is a size limit of 100 kB per message on the
5199 u-boot mailing list. Bigger patches will be moderated. If they are
5200 reasonable and not too big, they will be acknowledged. But patches
5201 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob