2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /pxa Files specific to Intel XScale PXA CPUs
145 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 /lib Architecture specific library files
147 /avr32 Files generic to AVR32 architecture
148 /cpu CPU specific files
149 /lib Architecture specific library files
150 /blackfin Files generic to Analog Devices Blackfin architecture
151 /cpu CPU specific files
152 /lib Architecture specific library files
153 /m68k Files generic to m68k architecture
154 /cpu CPU specific files
155 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
156 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
157 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
158 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
159 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
160 /lib Architecture specific library files
161 /microblaze Files generic to microblaze architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /mips Files generic to MIPS architecture
165 /cpu CPU specific files
166 /mips32 Files specific to MIPS32 CPUs
167 /xburst Files specific to Ingenic XBurst CPUs
168 /lib Architecture specific library files
169 /nds32 Files generic to NDS32 architecture
170 /cpu CPU specific files
171 /n1213 Files specific to Andes Technology N1213 CPUs
172 /lib Architecture specific library files
173 /nios2 Files generic to Altera NIOS2 architecture
174 /cpu CPU specific files
175 /lib Architecture specific library files
176 /openrisc Files generic to OpenRISC architecture
177 /cpu CPU specific files
178 /lib Architecture specific library files
179 /powerpc Files generic to PowerPC architecture
180 /cpu CPU specific files
181 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
182 /mpc5xx Files specific to Freescale MPC5xx CPUs
183 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
184 /mpc8xx Files specific to Freescale MPC8xx CPUs
185 /mpc824x Files specific to Freescale MPC824x CPUs
186 /mpc8260 Files specific to Freescale MPC8260 CPUs
187 /mpc85xx Files specific to Freescale MPC85xx CPUs
188 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
189 /lib Architecture specific library files
190 /sh Files generic to SH architecture
191 /cpu CPU specific files
192 /sh2 Files specific to sh2 CPUs
193 /sh3 Files specific to sh3 CPUs
194 /sh4 Files specific to sh4 CPUs
195 /lib Architecture specific library files
196 /sparc Files generic to SPARC architecture
197 /cpu CPU specific files
198 /leon2 Files specific to Gaisler LEON2 SPARC CPU
199 /leon3 Files specific to Gaisler LEON3 SPARC CPU
200 /lib Architecture specific library files
201 /x86 Files generic to x86 architecture
202 /cpu CPU specific files
203 /lib Architecture specific library files
204 /api Machine/arch independent API for external apps
205 /board Board dependent files
206 /common Misc architecture independent functions
207 /disk Code for disk drive partition handling
208 /doc Documentation (don't expect too much)
209 /drivers Commonly used device drivers
210 /dts Contains Makefile for building internal U-Boot fdt.
211 /examples Example code for standalone applications, etc.
212 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
213 /include Header Files
214 /lib Files generic to all architectures
215 /libfdt Library files to support flattened device trees
216 /lzma Library files to support LZMA decompression
217 /lzo Library files to support LZO decompression
219 /post Power On Self Test
220 /spl Secondary Program Loader framework
221 /tools Tools to build S-Record or U-Boot images, etc.
223 Software Configuration:
224 =======================
226 Configuration is usually done using C preprocessor defines; the
227 rationale behind that is to avoid dead code whenever possible.
229 There are two classes of configuration variables:
231 * Configuration _OPTIONS_:
232 These are selectable by the user and have names beginning with
235 * Configuration _SETTINGS_:
236 These depend on the hardware etc. and should not be meddled with if
237 you don't know what you're doing; they have names beginning with
240 Later we will add a configuration tool - probably similar to or even
241 identical to what's used for the Linux kernel. Right now, we have to
242 do the configuration by hand, which means creating some symbolic
243 links and editing some configuration files. We use the TQM8xxL boards
247 Selection of Processor Architecture and Board Type:
248 ---------------------------------------------------
250 For all supported boards there are ready-to-use default
251 configurations available; just type "make <board_name>_config".
253 Example: For a TQM823L module type:
258 For the Cogent platform, you need to specify the CPU type as well;
259 e.g. "make cogent_mpc8xx_config". And also configure the cogent
260 directory according to the instructions in cogent/README.
263 Configuration Options:
264 ----------------------
266 Configuration depends on the combination of board and CPU type; all
267 such information is kept in a configuration file
268 "include/configs/<board_name>.h".
270 Example: For a TQM823L module, all configuration settings are in
271 "include/configs/TQM823L.h".
274 Many of the options are named exactly as the corresponding Linux
275 kernel configuration options. The intention is to make it easier to
276 build a config tool - later.
279 The following options need to be configured:
281 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
283 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
285 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
286 Define exactly one, e.g. CONFIG_ATSTK1002
288 - CPU Module Type: (if CONFIG_COGENT is defined)
289 Define exactly one of
291 --- FIXME --- not tested yet:
292 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
293 CONFIG_CMA287_23, CONFIG_CMA287_50
295 - Motherboard Type: (if CONFIG_COGENT is defined)
296 Define exactly one of
297 CONFIG_CMA101, CONFIG_CMA102
299 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
300 Define one or more of
303 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
304 Define one or more of
305 CONFIG_LCD_HEARTBEAT - update a character position on
306 the LCD display every second with
309 - Board flavour: (if CONFIG_MPC8260ADS is defined)
312 CONFIG_SYS_8260ADS - original MPC8260ADS
313 CONFIG_SYS_8266ADS - MPC8266ADS
314 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
315 CONFIG_SYS_8272ADS - MPC8272ADS
317 - Marvell Family Member
318 CONFIG_SYS_MVFS - define it if you want to enable
319 multiple fs option at one time
320 for marvell soc family
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
357 Specifies that the core is a 64-bit PowerPC implementation (implements
358 the "64" category of the Power ISA). This is necessary for ePAPR
359 compliance, among other possible reasons.
361 CONFIG_SYS_FSL_TBCLK_DIV
363 Defines the core time base clock divider ratio compared to the
364 system clock. On most PQ3 devices this is 8, on newer QorIQ
365 devices it can be 16 or 32. The ratio varies from SoC to Soc.
367 CONFIG_SYS_FSL_PCIE_COMPAT
369 Defines the string to utilize when trying to match PCIe device
370 tree nodes for the given platform.
372 CONFIG_SYS_PPC_E500_DEBUG_TLB
374 Enables a temporary TLB entry to be used during boot to work
375 around limitations in e500v1 and e500v2 external debugger
376 support. This reduces the portions of the boot code where
377 breakpoints and single stepping do not work. The value of this
378 symbol should be set to the TLB1 entry to be used for this
381 CONFIG_SYS_FSL_ERRATUM_A004510
383 Enables a workaround for erratum A004510. If set,
384 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
385 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
390 Defines one or two SoC revisions (low 8 bits of SVR)
391 for which the A004510 workaround should be applied.
393 The rest of SVR is either not relevant to the decision
394 of whether the erratum is present (e.g. p2040 versus
395 p2041) or is implied by the build target, which controls
396 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
398 See Freescale App Note 4493 for more information about
401 CONFIG_A003399_NOR_WORKAROUND
402 Enables a workaround for IFC erratum A003399. It is only
403 requred during NOR boot.
405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
407 This is the value to write into CCSR offset 0x18600
408 according to the A004510 workaround.
410 CONFIG_SYS_FSL_DSP_DDR_ADDR
411 This value denotes start offset of DDR memory which is
412 connected exclusively to the DSP cores.
414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
415 This value denotes start offset of M2 memory
416 which is directly connected to the DSP core.
418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
419 This value denotes start offset of M3 memory which is directly
420 connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
423 This value denotes start offset of DSP CCSR space.
425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
426 Single Source Clock is clocking mode present in some of FSL SoC's.
427 In this mode, a single differential clock is used to supply
428 clocks to the sysclock, ddrclock and usbclock.
430 - Generic CPU options:
431 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
433 Defines the endianess of the CPU. Implementation of those
434 values is arch specific.
437 Freescale DDR driver in use. This type of DDR controller is
438 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
441 CONFIG_SYS_FSL_DDR_ADDR
442 Freescale DDR memory-mapped register base.
444 CONFIG_SYS_FSL_DDR_EMU
445 Specify emulator support for DDR. Some DDR features such as
446 deskew training are not available.
448 CONFIG_SYS_FSL_DDRC_GEN1
449 Freescale DDR1 controller.
451 CONFIG_SYS_FSL_DDRC_GEN2
452 Freescale DDR2 controller.
454 CONFIG_SYS_FSL_DDRC_GEN3
455 Freescale DDR3 controller.
457 CONFIG_SYS_FSL_DDRC_ARM_GEN3
458 Freescale DDR3 controller for ARM-based SoCs.
461 Board config to use DDR1. It can be enabled for SoCs with
462 Freescale DDR1 or DDR2 controllers, depending on the board
466 Board config to use DDR2. It can be eanbeld for SoCs with
467 Freescale DDR2 or DDR3 controllers, depending on the board
471 Board config to use DDR3. It can be enabled for SoCs with
472 Freescale DDR3 controllers.
474 CONFIG_SYS_FSL_PBL_PBI
475 It enables addition of RCW (Power on reset configuration) in built image.
476 Please refer doc/README.pblimage for more details
478 CONFIG_SYS_FSL_PBL_RCW
479 It adds PBI(pre-boot instructions) commands in u-boot build image.
480 PBI commands can be used to configure SoC before it starts the execution.
481 Please refer doc/README.pblimage for more details
483 - Intel Monahans options:
484 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
486 Defines the Monahans run mode to oscillator
487 ratio. Valid values are 8, 16, 24, 31. The core
488 frequency is this value multiplied by 13 MHz.
490 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
492 Defines the Monahans turbo mode to oscillator
493 ratio. Valid values are 1 (default if undefined) and
494 2. The core frequency as calculated above is multiplied
498 CONFIG_SYS_INIT_SP_OFFSET
500 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
501 pointer. This is needed for the temporary stack before
504 CONFIG_SYS_MIPS_CACHE_MODE
506 Cache operation mode for the MIPS CPU.
507 See also arch/mips/include/asm/mipsregs.h.
509 CONF_CM_CACHABLE_NO_WA
512 CONF_CM_CACHABLE_NONCOHERENT
516 CONF_CM_CACHABLE_ACCELERATED
518 CONFIG_SYS_XWAY_EBU_BOOTCFG
520 Special option for Lantiq XWAY SoCs for booting from NOR flash.
521 See also arch/mips/cpu/mips32/start.S.
523 CONFIG_XWAY_SWAP_BYTES
525 Enable compilation of tools/xway-swap-bytes needed for Lantiq
526 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
527 be swapped if a flash programmer is used.
530 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
532 Select high exception vectors of the ARM core, e.g., do not
533 clear the V bit of the c1 register of CP15.
535 CONFIG_SYS_THUMB_BUILD
537 Use this flag to build U-Boot using the Thumb instruction
538 set for ARM architectures. Thumb instruction set provides
539 better code density. For ARM architectures that support
540 Thumb2 this flag will result in Thumb2 code generated by
543 CONFIG_ARM_ERRATA_716044
544 CONFIG_ARM_ERRATA_742230
545 CONFIG_ARM_ERRATA_743622
546 CONFIG_ARM_ERRATA_751472
548 If set, the workarounds for these ARM errata are applied early
549 during U-Boot startup. Note that these options force the
550 workarounds to be applied; no CPU-type/version detection
551 exists, unlike the similar options in the Linux kernel. Do not
552 set these options unless they apply!
557 The frequency of the timer returned by get_timer().
558 get_timer() must operate in milliseconds and this CONFIG
559 option must be set to 1000.
561 - Linux Kernel Interface:
564 U-Boot stores all clock information in Hz
565 internally. For binary compatibility with older Linux
566 kernels (which expect the clocks passed in the
567 bd_info data to be in MHz) the environment variable
568 "clocks_in_mhz" can be defined so that U-Boot
569 converts clock data to MHZ before passing it to the
571 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
572 "clocks_in_mhz=1" is automatically included in the
575 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
577 When transferring memsize parameter to linux, some versions
578 expect it to be in bytes, others in MB.
579 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
583 New kernel versions are expecting firmware settings to be
584 passed using flattened device trees (based on open firmware
588 * New libfdt-based support
589 * Adds the "fdt" command
590 * The bootm command automatically updates the fdt
592 OF_CPU - The proper name of the cpus node (only required for
593 MPC512X and MPC5xxx based boards).
594 OF_SOC - The proper name of the soc node (only required for
595 MPC512X and MPC5xxx based boards).
596 OF_TBCLK - The timebase frequency.
597 OF_STDOUT_PATH - The path to the console device
599 boards with QUICC Engines require OF_QE to set UCC MAC
602 CONFIG_OF_BOARD_SETUP
604 Board code has addition modification that it wants to make
605 to the flat device tree before handing it off to the kernel
609 This define fills in the correct boot CPU in the boot
610 param header, the default value is zero if undefined.
614 U-Boot can detect if an IDE device is present or not.
615 If not, and this new config option is activated, U-Boot
616 removes the ATA node from the DTS before booting Linux,
617 so the Linux IDE driver does not probe the device and
618 crash. This is needed for buggy hardware (uc101) where
619 no pull down resistor is connected to the signal IDE5V_DD7.
621 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
623 This setting is mandatory for all boards that have only one
624 machine type and must be used to specify the machine type
625 number as it appears in the ARM machine registry
626 (see http://www.arm.linux.org.uk/developer/machines/).
627 Only boards that have multiple machine types supported
628 in a single configuration file and the machine type is
629 runtime discoverable, do not have to use this setting.
631 - vxWorks boot parameters:
633 bootvx constructs a valid bootline using the following
634 environments variables: bootfile, ipaddr, serverip, hostname.
635 It loads the vxWorks image pointed bootfile.
637 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
638 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
639 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
640 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
642 CONFIG_SYS_VXWORKS_ADD_PARAMS
644 Add it at the end of the bootline. E.g "u=username pw=secret"
646 Note: If a "bootargs" environment is defined, it will overwride
647 the defaults discussed just above.
649 - Cache Configuration:
650 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
651 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
652 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
654 - Cache Configuration for ARM:
655 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
657 CONFIG_SYS_PL310_BASE - Physical base address of PL310
658 controller register space
663 Define this if you want support for Amba PrimeCell PL010 UARTs.
667 Define this if you want support for Amba PrimeCell PL011 UARTs.
671 If you have Amba PrimeCell PL011 UARTs, set this variable to
672 the clock speed of the UARTs.
676 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
677 define this to a list of base addresses for each (supported)
678 port. See e.g. include/configs/versatile.h
680 CONFIG_PL011_SERIAL_RLCR
682 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
683 have separate receive and transmit line control registers. Set
684 this variable to initialize the extra register.
686 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
688 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
689 boot loader that has already initialized the UART. Define this
690 variable to flush the UART at init time.
694 Depending on board, define exactly one serial port
695 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
696 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
697 console by defining CONFIG_8xx_CONS_NONE
699 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
700 port routines must be defined elsewhere
701 (i.e. serial_init(), serial_getc(), ...)
704 Enables console device for a color framebuffer. Needs following
705 defines (cf. smiLynxEM, i8042)
706 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
708 VIDEO_HW_RECTFILL graphic chip supports
711 VIDEO_HW_BITBLT graphic chip supports
712 bit-blit (cf. smiLynxEM)
713 VIDEO_VISIBLE_COLS visible pixel columns
715 VIDEO_VISIBLE_ROWS visible pixel rows
716 VIDEO_PIXEL_SIZE bytes per pixel
717 VIDEO_DATA_FORMAT graphic data format
718 (0-5, cf. cfb_console.c)
719 VIDEO_FB_ADRS framebuffer address
720 VIDEO_KBD_INIT_FCT keyboard int fct
721 (i.e. i8042_kbd_init())
722 VIDEO_TSTC_FCT test char fct
724 VIDEO_GETC_FCT get char fct
726 CONFIG_CONSOLE_CURSOR cursor drawing on/off
727 (requires blink timer
729 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
730 CONFIG_CONSOLE_TIME display time/date info in
732 (requires CONFIG_CMD_DATE)
733 CONFIG_VIDEO_LOGO display Linux logo in
735 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
736 linux_logo.h for logo.
737 Requires CONFIG_VIDEO_LOGO
738 CONFIG_CONSOLE_EXTRA_INFO
739 additional board info beside
742 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
743 a limited number of ANSI escape sequences (cursor control,
744 erase functions and limited graphics rendition control).
746 When CONFIG_CFB_CONSOLE is defined, video console is
747 default i/o. Serial console can be forced with
748 environment 'console=serial'.
750 When CONFIG_SILENT_CONSOLE is defined, all console
751 messages (by U-Boot and Linux!) can be silenced with
752 the "silent" environment variable. See
753 doc/README.silent for more information.
755 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
757 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
761 CONFIG_BAUDRATE - in bps
762 Select one of the baudrates listed in
763 CONFIG_SYS_BAUDRATE_TABLE, see below.
764 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
766 - Console Rx buffer length
767 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
768 the maximum receive buffer length for the SMC.
769 This option is actual only for 82xx and 8xx possible.
770 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
771 must be defined, to setup the maximum idle timeout for
774 - Pre-Console Buffer:
775 Prior to the console being initialised (i.e. serial UART
776 initialised etc) all console output is silently discarded.
777 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
778 buffer any console messages prior to the console being
779 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
780 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
781 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
782 bytes are output before the console is initialised, the
783 earlier bytes are discarded.
785 'Sane' compilers will generate smaller code if
786 CONFIG_PRE_CON_BUF_SZ is a power of 2
788 - Safe printf() functions
789 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
790 the printf() functions. These are defined in
791 include/vsprintf.h and include snprintf(), vsnprintf() and
792 so on. Code size increase is approximately 300-500 bytes.
793 If this option is not given then these functions will
794 silently discard their buffer size argument - this means
795 you are not getting any overflow checking in this case.
797 - Boot Delay: CONFIG_BOOTDELAY - in seconds
798 Delay before automatically booting the default image;
799 set to -1 to disable autoboot.
800 set to -2 to autoboot with no delay and not check for abort
801 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
803 See doc/README.autoboot for these options that
804 work with CONFIG_BOOTDELAY. None are required.
805 CONFIG_BOOT_RETRY_TIME
806 CONFIG_BOOT_RETRY_MIN
807 CONFIG_AUTOBOOT_KEYED
808 CONFIG_AUTOBOOT_PROMPT
809 CONFIG_AUTOBOOT_DELAY_STR
810 CONFIG_AUTOBOOT_STOP_STR
811 CONFIG_AUTOBOOT_DELAY_STR2
812 CONFIG_AUTOBOOT_STOP_STR2
813 CONFIG_ZERO_BOOTDELAY_CHECK
814 CONFIG_RESET_TO_RETRY
818 Only needed when CONFIG_BOOTDELAY is enabled;
819 define a command string that is automatically executed
820 when no character is read on the console interface
821 within "Boot Delay" after reset.
824 This can be used to pass arguments to the bootm
825 command. The value of CONFIG_BOOTARGS goes into the
826 environment value "bootargs".
828 CONFIG_RAMBOOT and CONFIG_NFSBOOT
829 The value of these goes into the environment as
830 "ramboot" and "nfsboot" respectively, and can be used
831 as a convenience, when switching between booting from
835 CONFIG_BOOTCOUNT_LIMIT
836 Implements a mechanism for detecting a repeating reboot
838 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
841 If no softreset save registers are found on the hardware
842 "bootcount" is stored in the environment. To prevent a
843 saveenv on all reboots, the environment variable
844 "upgrade_available" is used. If "upgrade_available" is
845 0, "bootcount" is always 0, if "upgrade_available" is
846 1 "bootcount" is incremented in the environment.
847 So the Userspace Applikation must set the "upgrade_available"
848 and "bootcount" variable to 0, if a boot was successfully.
853 When this option is #defined, the existence of the
854 environment variable "preboot" will be checked
855 immediately before starting the CONFIG_BOOTDELAY
856 countdown and/or running the auto-boot command resp.
857 entering interactive mode.
859 This feature is especially useful when "preboot" is
860 automatically generated or modified. For an example
861 see the LWMON board specific code: here "preboot" is
862 modified when the user holds down a certain
863 combination of keys on the (special) keyboard when
866 - Serial Download Echo Mode:
868 If defined to 1, all characters received during a
869 serial download (using the "loads" command) are
870 echoed back. This might be needed by some terminal
871 emulations (like "cu"), but may as well just take
872 time on others. This setting #define's the initial
873 value of the "loads_echo" environment variable.
875 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
877 Select one of the baudrates listed in
878 CONFIG_SYS_BAUDRATE_TABLE, see below.
881 Monitor commands can be included or excluded
882 from the build by using the #include files
883 <config_cmd_all.h> and #undef'ing unwanted
884 commands, or using <config_cmd_default.h>
885 and augmenting with additional #define's
888 The default command configuration includes all commands
889 except those marked below with a "*".
891 CONFIG_CMD_ASKENV * ask for env variable
892 CONFIG_CMD_BDI bdinfo
893 CONFIG_CMD_BEDBUG * Include BedBug Debugger
894 CONFIG_CMD_BMP * BMP support
895 CONFIG_CMD_BSP * Board specific commands
896 CONFIG_CMD_BOOTD bootd
897 CONFIG_CMD_CACHE * icache, dcache
898 CONFIG_CMD_CONSOLE coninfo
899 CONFIG_CMD_CRC32 * crc32
900 CONFIG_CMD_DATE * support for RTC, date/time...
901 CONFIG_CMD_DHCP * DHCP support
902 CONFIG_CMD_DIAG * Diagnostics
903 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
904 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
905 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
906 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
907 CONFIG_CMD_DTT * Digital Therm and Thermostat
908 CONFIG_CMD_ECHO echo arguments
909 CONFIG_CMD_EDITENV edit env variable
910 CONFIG_CMD_EEPROM * EEPROM read/write support
911 CONFIG_CMD_ELF * bootelf, bootvx
912 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
913 CONFIG_CMD_ENV_FLAGS * display details about env flags
914 CONFIG_CMD_ENV_EXISTS * check existence of env variable
915 CONFIG_CMD_EXPORTENV * export the environment
916 CONFIG_CMD_EXT2 * ext2 command support
917 CONFIG_CMD_EXT4 * ext4 command support
918 CONFIG_CMD_SAVEENV saveenv
919 CONFIG_CMD_FDC * Floppy Disk Support
920 CONFIG_CMD_FAT * FAT command support
921 CONFIG_CMD_FDOS * Dos diskette Support
922 CONFIG_CMD_FLASH flinfo, erase, protect
923 CONFIG_CMD_FPGA FPGA device initialization support
924 CONFIG_CMD_FUSE * Device fuse support
925 CONFIG_CMD_GETTIME * Get time since boot
926 CONFIG_CMD_GO * the 'go' command (exec code)
927 CONFIG_CMD_GREPENV * search environment
928 CONFIG_CMD_HASH * calculate hash / digest
929 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
930 CONFIG_CMD_I2C * I2C serial bus support
931 CONFIG_CMD_IDE * IDE harddisk support
932 CONFIG_CMD_IMI iminfo
933 CONFIG_CMD_IMLS List all images found in NOR flash
934 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
935 CONFIG_CMD_IMMAP * IMMR dump support
936 CONFIG_CMD_IMPORTENV * import an environment
937 CONFIG_CMD_INI * import data from an ini file into the env
938 CONFIG_CMD_IRQ * irqinfo
939 CONFIG_CMD_ITEST Integer/string test of 2 values
940 CONFIG_CMD_JFFS2 * JFFS2 Support
941 CONFIG_CMD_KGDB * kgdb
942 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
943 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
945 CONFIG_CMD_LOADB loadb
946 CONFIG_CMD_LOADS loads
947 CONFIG_CMD_MD5SUM * print md5 message digest
948 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
949 CONFIG_CMD_MEMINFO * Display detailed memory information
950 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
952 CONFIG_CMD_MEMTEST * mtest
953 CONFIG_CMD_MISC Misc functions like sleep etc
954 CONFIG_CMD_MMC * MMC memory mapped support
955 CONFIG_CMD_MII * MII utility commands
956 CONFIG_CMD_MTDPARTS * MTD partition support
957 CONFIG_CMD_NAND * NAND support
958 CONFIG_CMD_NET bootp, tftpboot, rarpboot
959 CONFIG_CMD_NFS NFS support
960 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
961 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
962 CONFIG_CMD_PCI * pciinfo
963 CONFIG_CMD_PCMCIA * PCMCIA support
964 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
966 CONFIG_CMD_PORTIO * Port I/O
967 CONFIG_CMD_READ * Read raw data from partition
968 CONFIG_CMD_REGINFO * Register dump
969 CONFIG_CMD_RUN run command in env variable
970 CONFIG_CMD_SANDBOX * sb command to access sandbox features
971 CONFIG_CMD_SAVES * save S record dump
972 CONFIG_CMD_SCSI * SCSI Support
973 CONFIG_CMD_SDRAM * print SDRAM configuration information
974 (requires CONFIG_CMD_I2C)
975 CONFIG_CMD_SETGETDCR Support for DCR Register access
977 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
978 CONFIG_CMD_SHA1SUM * print sha1 memory digest
979 (requires CONFIG_CMD_MEMORY)
980 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
981 CONFIG_CMD_SOURCE "source" command Support
982 CONFIG_CMD_SPI * SPI serial bus support
983 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
984 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
985 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
986 CONFIG_CMD_TIMER * access to the system tick timer
987 CONFIG_CMD_USB * USB support
988 CONFIG_CMD_CDP * Cisco Discover Protocol support
989 CONFIG_CMD_MFSL * Microblaze FSL support
990 CONFIG_CMD_XIMG Load part of Multi Image
993 EXAMPLE: If you want all functions except of network
994 support you can write:
996 #include "config_cmd_all.h"
997 #undef CONFIG_CMD_NET
1000 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1002 Note: Don't enable the "icache" and "dcache" commands
1003 (configuration option CONFIG_CMD_CACHE) unless you know
1004 what you (and your U-Boot users) are doing. Data
1005 cache cannot be enabled on systems like the 8xx or
1006 8260 (where accesses to the IMMR region must be
1007 uncached), and it cannot be disabled on all other
1008 systems where we (mis-) use the data cache to hold an
1009 initial stack and some data.
1012 XXX - this list needs to get updated!
1014 - Regular expression support:
1016 If this variable is defined, U-Boot is linked against
1017 the SLRE (Super Light Regular Expression) library,
1018 which adds regex support to some commands, as for
1019 example "env grep" and "setexpr".
1023 If this variable is defined, U-Boot will use a device tree
1024 to configure its devices, instead of relying on statically
1025 compiled #defines in the board file. This option is
1026 experimental and only available on a few boards. The device
1027 tree is available in the global data as gd->fdt_blob.
1029 U-Boot needs to get its device tree from somewhere. This can
1030 be done using one of the two options below:
1033 If this variable is defined, U-Boot will embed a device tree
1034 binary in its image. This device tree file should be in the
1035 board directory and called <soc>-<board>.dts. The binary file
1036 is then picked up in board_init_f() and made available through
1037 the global data structure as gd->blob.
1040 If this variable is defined, U-Boot will build a device tree
1041 binary. It will be called u-boot.dtb. Architecture-specific
1042 code will locate it at run-time. Generally this works by:
1044 cat u-boot.bin u-boot.dtb >image.bin
1046 and in fact, U-Boot does this for you, creating a file called
1047 u-boot-dtb.bin which is useful in the common case. You can
1048 still use the individual files if you need something more
1053 If this variable is defined, it enables watchdog
1054 support for the SoC. There must be support in the SoC
1055 specific code for a watchdog. For the 8xx and 8260
1056 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1057 register. When supported for a specific SoC is
1058 available, then no further board specific code should
1059 be needed to use it.
1062 When using a watchdog circuitry external to the used
1063 SoC, then define this variable and provide board
1064 specific code for the "hw_watchdog_reset" function.
1067 CONFIG_VERSION_VARIABLE
1068 If this variable is defined, an environment variable
1069 named "ver" is created by U-Boot showing the U-Boot
1070 version as printed by the "version" command.
1071 Any change to this variable will be reverted at the
1076 When CONFIG_CMD_DATE is selected, the type of the RTC
1077 has to be selected, too. Define exactly one of the
1080 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1081 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1082 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1083 CONFIG_RTC_MC146818 - use MC146818 RTC
1084 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1085 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1086 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1087 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1088 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1089 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1090 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1091 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1094 Note that if the RTC uses I2C, then the I2C interface
1095 must also be configured. See I2C Support, below.
1098 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1100 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1101 chip-ngpio pairs that tell the PCA953X driver the number of
1102 pins supported by a particular chip.
1104 Note that if the GPIO device uses I2C, then the I2C interface
1105 must also be configured. See I2C Support, below.
1107 - Timestamp Support:
1109 When CONFIG_TIMESTAMP is selected, the timestamp
1110 (date and time) of an image is printed by image
1111 commands like bootm or iminfo. This option is
1112 automatically enabled when you select CONFIG_CMD_DATE .
1114 - Partition Labels (disklabels) Supported:
1115 Zero or more of the following:
1116 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1117 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1118 Intel architecture, USB sticks, etc.
1119 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1120 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1121 bootloader. Note 2TB partition limit; see
1123 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1125 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1126 CONFIG_CMD_SCSI) you must configure support for at
1127 least one non-MTD partition type as well.
1130 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1131 board configurations files but used nowhere!
1133 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1134 be performed by calling the function
1135 ide_set_reset(int reset)
1136 which has to be defined in a board specific file
1141 Set this to enable ATAPI support.
1146 Set this to enable support for disks larger than 137GB
1147 Also look at CONFIG_SYS_64BIT_LBA.
1148 Whithout these , LBA48 support uses 32bit variables and will 'only'
1149 support disks up to 2.1TB.
1151 CONFIG_SYS_64BIT_LBA:
1152 When enabled, makes the IDE subsystem use 64bit sector addresses.
1156 At the moment only there is only support for the
1157 SYM53C8XX SCSI controller; define
1158 CONFIG_SCSI_SYM53C8XX to enable it.
1160 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1161 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1162 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1163 maximum numbers of LUNs, SCSI ID's and target
1165 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1167 The environment variable 'scsidevs' is set to the number of
1168 SCSI devices found during the last scan.
1170 - NETWORK Support (PCI):
1172 Support for Intel 8254x/8257x gigabit chips.
1175 Utility code for direct access to the SPI bus on Intel 8257x.
1176 This does not do anything useful unless you set at least one
1177 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1179 CONFIG_E1000_SPI_GENERIC
1180 Allow generic access to the SPI bus on the Intel 8257x, for
1181 example with the "sspi" command.
1184 Management command for E1000 devices. When used on devices
1185 with SPI support you can reprogram the EEPROM from U-Boot.
1187 CONFIG_E1000_FALLBACK_MAC
1188 default MAC for empty EEPROM after production.
1191 Support for Intel 82557/82559/82559ER chips.
1192 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1193 write routine for first time initialisation.
1196 Support for Digital 2114x chips.
1197 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1198 modem chip initialisation (KS8761/QS6611).
1201 Support for National dp83815 chips.
1204 Support for National dp8382[01] gigabit chips.
1206 - NETWORK Support (other):
1208 CONFIG_DRIVER_AT91EMAC
1209 Support for AT91RM9200 EMAC.
1212 Define this to use reduced MII inteface
1214 CONFIG_DRIVER_AT91EMAC_QUIET
1215 If this defined, the driver is quiet.
1216 The driver doen't show link status messages.
1218 CONFIG_CALXEDA_XGMAC
1219 Support for the Calxeda XGMAC device
1222 Support for SMSC's LAN91C96 chips.
1224 CONFIG_LAN91C96_BASE
1225 Define this to hold the physical address
1226 of the LAN91C96's I/O space
1228 CONFIG_LAN91C96_USE_32_BIT
1229 Define this to enable 32 bit addressing
1232 Support for SMSC's LAN91C111 chip
1234 CONFIG_SMC91111_BASE
1235 Define this to hold the physical address
1236 of the device (I/O space)
1238 CONFIG_SMC_USE_32_BIT
1239 Define this if data bus is 32 bits
1241 CONFIG_SMC_USE_IOFUNCS
1242 Define this to use i/o functions instead of macros
1243 (some hardware wont work with macros)
1245 CONFIG_DRIVER_TI_EMAC
1246 Support for davinci emac
1248 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1249 Define this if you have more then 3 PHYs.
1252 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1254 CONFIG_FTGMAC100_EGIGA
1255 Define this to use GE link update with gigabit PHY.
1256 Define this if FTGMAC100 is connected to gigabit PHY.
1257 If your system has 10/100 PHY only, it might not occur
1258 wrong behavior. Because PHY usually return timeout or
1259 useless data when polling gigabit status and gigabit
1260 control registers. This behavior won't affect the
1261 correctnessof 10/100 link speed update.
1264 Support for SMSC's LAN911x and LAN921x chips
1267 Define this to hold the physical address
1268 of the device (I/O space)
1270 CONFIG_SMC911X_32_BIT
1271 Define this if data bus is 32 bits
1273 CONFIG_SMC911X_16_BIT
1274 Define this if data bus is 16 bits. If your processor
1275 automatically converts one 32 bit word to two 16 bit
1276 words you may also try CONFIG_SMC911X_32_BIT.
1279 Support for Renesas on-chip Ethernet controller
1281 CONFIG_SH_ETHER_USE_PORT
1282 Define the number of ports to be used
1284 CONFIG_SH_ETHER_PHY_ADDR
1285 Define the ETH PHY's address
1287 CONFIG_SH_ETHER_CACHE_WRITEBACK
1288 If this option is set, the driver enables cache flush.
1292 Support TPM devices.
1295 Support for i2c bus TPM devices. Only one device
1296 per system is supported at this time.
1298 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1299 Define the the i2c bus number for the TPM device
1301 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1302 Define the TPM's address on the i2c bus
1304 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1305 Define the burst count bytes upper limit
1307 CONFIG_TPM_ATMEL_TWI
1308 Support for Atmel TWI TPM device. Requires I2C support.
1311 Support for generic parallel port TPM devices. Only one device
1312 per system is supported at this time.
1314 CONFIG_TPM_TIS_BASE_ADDRESS
1315 Base address where the generic TPM device is mapped
1316 to. Contemporary x86 systems usually map it at
1320 Add tpm monitor functions.
1321 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1322 provides monitor access to authorized functions.
1325 Define this to enable the TPM support library which provides
1326 functional interfaces to some TPM commands.
1327 Requires support for a TPM device.
1329 CONFIG_TPM_AUTH_SESSIONS
1330 Define this to enable authorized functions in the TPM library.
1331 Requires CONFIG_TPM and CONFIG_SHA1.
1334 At the moment only the UHCI host controller is
1335 supported (PIP405, MIP405, MPC5200); define
1336 CONFIG_USB_UHCI to enable it.
1337 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1338 and define CONFIG_USB_STORAGE to enable the USB
1341 Supported are USB Keyboards and USB Floppy drives
1343 MPC5200 USB requires additional defines:
1345 for 528 MHz Clock: 0x0001bbbb
1349 for differential drivers: 0x00001000
1350 for single ended drivers: 0x00005000
1351 for differential drivers on PSC3: 0x00000100
1352 for single ended drivers on PSC3: 0x00004100
1353 CONFIG_SYS_USB_EVENT_POLL
1354 May be defined to allow interrupt polling
1355 instead of using asynchronous interrupts
1357 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1358 txfilltuning field in the EHCI controller on reset.
1360 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1361 interval for usb hub power-on delay.(minimum 100msec)
1364 Define the below if you wish to use the USB console.
1365 Once firmware is rebuilt from a serial console issue the
1366 command "setenv stdin usbtty; setenv stdout usbtty" and
1367 attach your USB cable. The Unix command "dmesg" should print
1368 it has found a new device. The environment variable usbtty
1369 can be set to gserial or cdc_acm to enable your device to
1370 appear to a USB host as a Linux gserial device or a
1371 Common Device Class Abstract Control Model serial device.
1372 If you select usbtty = gserial you should be able to enumerate
1374 # modprobe usbserial vendor=0xVendorID product=0xProductID
1375 else if using cdc_acm, simply setting the environment
1376 variable usbtty to be cdc_acm should suffice. The following
1377 might be defined in YourBoardName.h
1380 Define this to build a UDC device
1383 Define this to have a tty type of device available to
1384 talk to the UDC device
1387 Define this to enable the high speed support for usb
1388 device and usbtty. If this feature is enabled, a routine
1389 int is_usbd_high_speed(void)
1390 also needs to be defined by the driver to dynamically poll
1391 whether the enumeration has succeded at high speed or full
1394 CONFIG_SYS_CONSOLE_IS_IN_ENV
1395 Define this if you want stdin, stdout &/or stderr to
1399 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1400 Derive USB clock from external clock "blah"
1401 - CONFIG_SYS_USB_EXTC_CLK 0x02
1403 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1404 Derive USB clock from brgclk
1405 - CONFIG_SYS_USB_BRG_CLK 0x04
1407 If you have a USB-IF assigned VendorID then you may wish to
1408 define your own vendor specific values either in BoardName.h
1409 or directly in usbd_vendor_info.h. If you don't define
1410 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1411 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1412 should pretend to be a Linux device to it's target host.
1414 CONFIG_USBD_MANUFACTURER
1415 Define this string as the name of your company for
1416 - CONFIG_USBD_MANUFACTURER "my company"
1418 CONFIG_USBD_PRODUCT_NAME
1419 Define this string as the name of your product
1420 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1422 CONFIG_USBD_VENDORID
1423 Define this as your assigned Vendor ID from the USB
1424 Implementors Forum. This *must* be a genuine Vendor ID
1425 to avoid polluting the USB namespace.
1426 - CONFIG_USBD_VENDORID 0xFFFF
1428 CONFIG_USBD_PRODUCTID
1429 Define this as the unique Product ID
1431 - CONFIG_USBD_PRODUCTID 0xFFFF
1433 Some USB device drivers may need to check USB cable attachment.
1434 In this case you can enable following config in BoardName.h:
1435 CONFIG_USB_CABLE_CHECK
1436 This enables function definition:
1437 - usb_cable_connected() in include/usb.h
1438 Implementation of this function is board-specific.
1440 - ULPI Layer Support:
1441 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1442 the generic ULPI layer. The generic layer accesses the ULPI PHY
1443 via the platform viewport, so you need both the genric layer and
1444 the viewport enabled. Currently only Chipidea/ARC based
1445 viewport is supported.
1446 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1447 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1448 If your ULPI phy needs a different reference clock than the
1449 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1450 the appropriate value in Hz.
1453 The MMC controller on the Intel PXA is supported. To
1454 enable this define CONFIG_MMC. The MMC can be
1455 accessed from the boot prompt by mapping the device
1456 to physical memory similar to flash. Command line is
1457 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1458 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1461 Support for Renesas on-chip MMCIF controller
1463 CONFIG_SH_MMCIF_ADDR
1464 Define the base address of MMCIF registers
1467 Define the clock frequency for MMCIF
1469 - USB Device Firmware Update (DFU) class support:
1471 This enables the USB portion of the DFU USB class
1474 This enables the command "dfu" which is used to have
1475 U-Boot create a DFU class device via USB. This command
1476 requires that the "dfu_alt_info" environment variable be
1477 set and define the alt settings to expose to the host.
1480 This enables support for exposing (e)MMC devices via DFU.
1483 This enables support for exposing NAND devices via DFU.
1486 This enables support for exposing RAM via DFU.
1487 Note: DFU spec refer to non-volatile memory usage, but
1488 allow usages beyond the scope of spec - here RAM usage,
1489 one that would help mostly the developer.
1491 CONFIG_SYS_DFU_DATA_BUF_SIZE
1492 Dfu transfer uses a buffer before writing data to the
1493 raw storage device. Make the size (in bytes) of this buffer
1494 configurable. The size of this buffer is also configurable
1495 through the "dfu_bufsiz" environment variable.
1497 CONFIG_SYS_DFU_MAX_FILE_SIZE
1498 When updating files rather than the raw storage device,
1499 we use a static buffer to copy the file into and then write
1500 the buffer once we've been given the whole file. Define
1501 this to the maximum filesize (in bytes) for the buffer.
1502 Default is 4 MiB if undefined.
1504 - Journaling Flash filesystem support:
1505 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1506 CONFIG_JFFS2_NAND_DEV
1507 Define these for a default partition on a NAND device
1509 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1510 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1511 Define these for a default partition on a NOR device
1513 CONFIG_SYS_JFFS_CUSTOM_PART
1514 Define this to create an own partition. You have to provide a
1515 function struct part_info* jffs2_part_info(int part_num)
1517 If you define only one JFFS2 partition you may also want to
1518 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1519 to disable the command chpart. This is the default when you
1520 have not defined a custom partition
1522 - FAT(File Allocation Table) filesystem write function support:
1525 Define this to enable support for saving memory data as a
1526 file in FAT formatted partition.
1528 This will also enable the command "fatwrite" enabling the
1529 user to write files to FAT.
1531 CBFS (Coreboot Filesystem) support
1534 Define this to enable support for reading from a Coreboot
1535 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1541 Define this to enable standard (PC-Style) keyboard
1545 Standard PC keyboard driver with US (is default) and
1546 GERMAN key layout (switch via environment 'keymap=de') support.
1547 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1548 for cfb_console. Supports cursor blinking.
1551 Enables a Chrome OS keyboard using the CROS_EC interface.
1552 This uses CROS_EC to communicate with a second microcontroller
1553 which provides key scans on request.
1558 Define this to enable video support (for output to
1561 CONFIG_VIDEO_CT69000
1563 Enable Chips & Technologies 69000 Video chip
1565 CONFIG_VIDEO_SMI_LYNXEM
1566 Enable Silicon Motion SMI 712/710/810 Video chip. The
1567 video output is selected via environment 'videoout'
1568 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1571 For the CT69000 and SMI_LYNXEM drivers, videomode is
1572 selected via environment 'videomode'. Two different ways
1574 - "videomode=num" 'num' is a standard LiLo mode numbers.
1575 Following standard modes are supported (* is default):
1577 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1578 -------------+---------------------------------------------
1579 8 bits | 0x301* 0x303 0x305 0x161 0x307
1580 15 bits | 0x310 0x313 0x316 0x162 0x319
1581 16 bits | 0x311 0x314 0x317 0x163 0x31A
1582 24 bits | 0x312 0x315 0x318 ? 0x31B
1583 -------------+---------------------------------------------
1584 (i.e. setenv videomode 317; saveenv; reset;)
1586 - "videomode=bootargs" all the video parameters are parsed
1587 from the bootargs. (See drivers/video/videomodes.c)
1590 CONFIG_VIDEO_SED13806
1591 Enable Epson SED13806 driver. This driver supports 8bpp
1592 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1593 or CONFIG_VIDEO_SED13806_16BPP
1596 Enable the Freescale DIU video driver. Reference boards for
1597 SOCs that have a DIU should define this macro to enable DIU
1598 support, and should also define these other macros:
1604 CONFIG_VIDEO_SW_CURSOR
1605 CONFIG_VGA_AS_SINGLE_DEVICE
1607 CONFIG_VIDEO_BMP_LOGO
1609 The DIU driver will look for the 'video-mode' environment
1610 variable, and if defined, enable the DIU as a console during
1611 boot. See the documentation file README.video for a
1612 description of this variable.
1616 Enable the VGA video / BIOS for x86. The alternative if you
1617 are using coreboot is to use the coreboot frame buffer
1624 Define this to enable a custom keyboard support.
1625 This simply calls drv_keyboard_init() which must be
1626 defined in your board-specific files.
1627 The only board using this so far is RBC823.
1629 - LCD Support: CONFIG_LCD
1631 Define this to enable LCD support (for output to LCD
1632 display); also select one of the supported displays
1633 by defining one of these:
1637 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1639 CONFIG_NEC_NL6448AC33:
1641 NEC NL6448AC33-18. Active, color, single scan.
1643 CONFIG_NEC_NL6448BC20
1645 NEC NL6448BC20-08. 6.5", 640x480.
1646 Active, color, single scan.
1648 CONFIG_NEC_NL6448BC33_54
1650 NEC NL6448BC33-54. 10.4", 640x480.
1651 Active, color, single scan.
1655 Sharp 320x240. Active, color, single scan.
1656 It isn't 16x9, and I am not sure what it is.
1658 CONFIG_SHARP_LQ64D341
1660 Sharp LQ64D341 display, 640x480.
1661 Active, color, single scan.
1665 HLD1045 display, 640x480.
1666 Active, color, single scan.
1670 Optrex CBL50840-2 NF-FW 99 22 M5
1672 Hitachi LMG6912RPFC-00T
1676 320x240. Black & white.
1678 Normally display is black on white background; define
1679 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1681 CONFIG_LCD_ALIGNMENT
1683 Normally the LCD is page-aligned (tyically 4KB). If this is
1684 defined then the LCD will be aligned to this value instead.
1685 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1686 here, since it is cheaper to change data cache settings on
1687 a per-section basis.
1689 CONFIG_CONSOLE_SCROLL_LINES
1691 When the console need to be scrolled, this is the number of
1692 lines to scroll by. It defaults to 1. Increasing this makes
1693 the console jump but can help speed up operation when scrolling
1698 Support drawing of RLE8-compressed bitmaps on the LCD.
1702 Enables an 'i2c edid' command which can read EDID
1703 information over I2C from an attached LCD display.
1705 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1707 If this option is set, the environment is checked for
1708 a variable "splashimage". If found, the usual display
1709 of logo, copyright and system information on the LCD
1710 is suppressed and the BMP image at the address
1711 specified in "splashimage" is loaded instead. The
1712 console is redirected to the "nulldev", too. This
1713 allows for a "silent" boot where a splash screen is
1714 loaded very quickly after power-on.
1716 CONFIG_SPLASHIMAGE_GUARD
1718 If this option is set, then U-Boot will prevent the environment
1719 variable "splashimage" from being set to a problematic address
1720 (see README.displaying-bmps and README.arm-unaligned-accesses).
1721 This option is useful for targets where, due to alignment
1722 restrictions, an improperly aligned BMP image will cause a data
1723 abort. If you think you will not have problems with unaligned
1724 accesses (for example because your toolchain prevents them)
1725 there is no need to set this option.
1727 CONFIG_SPLASH_SCREEN_ALIGN
1729 If this option is set the splash image can be freely positioned
1730 on the screen. Environment variable "splashpos" specifies the
1731 position as "x,y". If a positive number is given it is used as
1732 number of pixel from left/top. If a negative number is given it
1733 is used as number of pixel from right/bottom. You can also
1734 specify 'm' for centering the image.
1737 setenv splashpos m,m
1738 => image at center of screen
1740 setenv splashpos 30,20
1741 => image at x = 30 and y = 20
1743 setenv splashpos -10,m
1744 => vertically centered image
1745 at x = dspWidth - bmpWidth - 9
1747 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1749 If this option is set, additionally to standard BMP
1750 images, gzipped BMP images can be displayed via the
1751 splashscreen support or the bmp command.
1753 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1755 If this option is set, 8-bit RLE compressed BMP images
1756 can be displayed via the splashscreen support or the
1759 - Do compresssing for memory range:
1762 If this option is set, it would use zlib deflate method
1763 to compress the specified memory at its best effort.
1765 - Compression support:
1768 Enabled by default to support gzip compressed images.
1772 If this option is set, support for bzip2 compressed
1773 images is included. If not, only uncompressed and gzip
1774 compressed images are supported.
1776 NOTE: the bzip2 algorithm requires a lot of RAM, so
1777 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1782 If this option is set, support for lzma compressed
1785 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1786 requires an amount of dynamic memory that is given by the
1789 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1791 Where lc and lp stand for, respectively, Literal context bits
1792 and Literal pos bits.
1794 This value is upper-bounded by 14MB in the worst case. Anyway,
1795 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1796 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1797 a very small buffer.
1799 Use the lzmainfo tool to determinate the lc and lp values and
1800 then calculate the amount of needed dynamic memory (ensuring
1801 the appropriate CONFIG_SYS_MALLOC_LEN value).
1805 If this option is set, support for LZO compressed images
1811 The address of PHY on MII bus.
1813 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1815 The clock frequency of the MII bus
1819 If this option is set, support for speed/duplex
1820 detection of gigabit PHY is included.
1822 CONFIG_PHY_RESET_DELAY
1824 Some PHY like Intel LXT971A need extra delay after
1825 reset before any MII register access is possible.
1826 For such PHY, set this option to the usec delay
1827 required. (minimum 300usec for LXT971A)
1829 CONFIG_PHY_CMD_DELAY (ppc4xx)
1831 Some PHY like Intel LXT971A need extra delay after
1832 command issued before MII status register can be read
1842 Define a default value for Ethernet address to use
1843 for the respective Ethernet interface, in case this
1844 is not determined automatically.
1849 Define a default value for the IP address to use for
1850 the default Ethernet interface, in case this is not
1851 determined through e.g. bootp.
1852 (Environment variable "ipaddr")
1854 - Server IP address:
1857 Defines a default value for the IP address of a TFTP
1858 server to contact when using the "tftboot" command.
1859 (Environment variable "serverip")
1861 CONFIG_KEEP_SERVERADDR
1863 Keeps the server's MAC address, in the env 'serveraddr'
1864 for passing to bootargs (like Linux's netconsole option)
1866 - Gateway IP address:
1869 Defines a default value for the IP address of the
1870 default router where packets to other networks are
1872 (Environment variable "gatewayip")
1877 Defines a default value for the subnet mask (or
1878 routing prefix) which is used to determine if an IP
1879 address belongs to the local subnet or needs to be
1880 forwarded through a router.
1881 (Environment variable "netmask")
1883 - Multicast TFTP Mode:
1886 Defines whether you want to support multicast TFTP as per
1887 rfc-2090; for example to work with atftp. Lets lots of targets
1888 tftp down the same boot image concurrently. Note: the Ethernet
1889 driver in use must provide a function: mcast() to join/leave a
1892 - BOOTP Recovery Mode:
1893 CONFIG_BOOTP_RANDOM_DELAY
1895 If you have many targets in a network that try to
1896 boot using BOOTP, you may want to avoid that all
1897 systems send out BOOTP requests at precisely the same
1898 moment (which would happen for instance at recovery
1899 from a power failure, when all systems will try to
1900 boot, thus flooding the BOOTP server. Defining
1901 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1902 inserted before sending out BOOTP requests. The
1903 following delays are inserted then:
1905 1st BOOTP request: delay 0 ... 1 sec
1906 2nd BOOTP request: delay 0 ... 2 sec
1907 3rd BOOTP request: delay 0 ... 4 sec
1909 BOOTP requests: delay 0 ... 8 sec
1911 - DHCP Advanced Options:
1912 You can fine tune the DHCP functionality by defining
1913 CONFIG_BOOTP_* symbols:
1915 CONFIG_BOOTP_SUBNETMASK
1916 CONFIG_BOOTP_GATEWAY
1917 CONFIG_BOOTP_HOSTNAME
1918 CONFIG_BOOTP_NISDOMAIN
1919 CONFIG_BOOTP_BOOTPATH
1920 CONFIG_BOOTP_BOOTFILESIZE
1923 CONFIG_BOOTP_SEND_HOSTNAME
1924 CONFIG_BOOTP_NTPSERVER
1925 CONFIG_BOOTP_TIMEOFFSET
1926 CONFIG_BOOTP_VENDOREX
1927 CONFIG_BOOTP_MAY_FAIL
1929 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1930 environment variable, not the BOOTP server.
1932 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1933 after the configured retry count, the call will fail
1934 instead of starting over. This can be used to fail over
1935 to Link-local IP address configuration if the DHCP server
1938 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1939 serverip from a DHCP server, it is possible that more
1940 than one DNS serverip is offered to the client.
1941 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1942 serverip will be stored in the additional environment
1943 variable "dnsip2". The first DNS serverip is always
1944 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1947 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1948 to do a dynamic update of a DNS server. To do this, they
1949 need the hostname of the DHCP requester.
1950 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1951 of the "hostname" environment variable is passed as
1952 option 12 to the DHCP server.
1954 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1956 A 32bit value in microseconds for a delay between
1957 receiving a "DHCP Offer" and sending the "DHCP Request".
1958 This fixes a problem with certain DHCP servers that don't
1959 respond 100% of the time to a "DHCP request". E.g. On an
1960 AT91RM9200 processor running at 180MHz, this delay needed
1961 to be *at least* 15,000 usec before a Windows Server 2003
1962 DHCP server would reply 100% of the time. I recommend at
1963 least 50,000 usec to be safe. The alternative is to hope
1964 that one of the retries will be successful but note that
1965 the DHCP timeout and retry process takes a longer than
1968 - Link-local IP address negotiation:
1969 Negotiate with other link-local clients on the local network
1970 for an address that doesn't require explicit configuration.
1971 This is especially useful if a DHCP server cannot be guaranteed
1972 to exist in all environments that the device must operate.
1974 See doc/README.link-local for more information.
1977 CONFIG_CDP_DEVICE_ID
1979 The device id used in CDP trigger frames.
1981 CONFIG_CDP_DEVICE_ID_PREFIX
1983 A two character string which is prefixed to the MAC address
1988 A printf format string which contains the ascii name of
1989 the port. Normally is set to "eth%d" which sets
1990 eth0 for the first Ethernet, eth1 for the second etc.
1992 CONFIG_CDP_CAPABILITIES
1994 A 32bit integer which indicates the device capabilities;
1995 0x00000010 for a normal host which does not forwards.
1999 An ascii string containing the version of the software.
2003 An ascii string containing the name of the platform.
2007 A 32bit integer sent on the trigger.
2009 CONFIG_CDP_POWER_CONSUMPTION
2011 A 16bit integer containing the power consumption of the
2012 device in .1 of milliwatts.
2014 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2016 A byte containing the id of the VLAN.
2018 - Status LED: CONFIG_STATUS_LED
2020 Several configurations allow to display the current
2021 status using a LED. For instance, the LED will blink
2022 fast while running U-Boot code, stop blinking as
2023 soon as a reply to a BOOTP request was received, and
2024 start blinking slow once the Linux kernel is running
2025 (supported by a status LED driver in the Linux
2026 kernel). Defining CONFIG_STATUS_LED enables this
2032 The status LED can be connected to a GPIO pin.
2033 In such cases, the gpio_led driver can be used as a
2034 status LED backend implementation. Define CONFIG_GPIO_LED
2035 to include the gpio_led driver in the U-Boot binary.
2037 CONFIG_GPIO_LED_INVERTED_TABLE
2038 Some GPIO connected LEDs may have inverted polarity in which
2039 case the GPIO high value corresponds to LED off state and
2040 GPIO low value corresponds to LED on state.
2041 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2042 with a list of GPIO LEDs that have inverted polarity.
2044 - CAN Support: CONFIG_CAN_DRIVER
2046 Defining CONFIG_CAN_DRIVER enables CAN driver support
2047 on those systems that support this (optional)
2048 feature, like the TQM8xxL modules.
2050 - I2C Support: CONFIG_SYS_I2C
2052 This enable the NEW i2c subsystem, and will allow you to use
2053 i2c commands at the u-boot command line (as long as you set
2054 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2055 based realtime clock chips or other i2c devices. See
2056 common/cmd_i2c.c for a description of the command line
2059 ported i2c driver to the new framework:
2060 - drivers/i2c/soft_i2c.c:
2061 - activate first bus with CONFIG_SYS_I2C_SOFT define
2062 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2063 for defining speed and slave address
2064 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2065 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2066 for defining speed and slave address
2067 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2068 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2069 for defining speed and slave address
2070 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2071 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2072 for defining speed and slave address
2074 - drivers/i2c/fsl_i2c.c:
2075 - activate i2c driver with CONFIG_SYS_I2C_FSL
2076 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2077 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2078 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2080 - If your board supports a second fsl i2c bus, define
2081 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2082 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2083 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2086 - drivers/i2c/tegra_i2c.c:
2087 - activate this driver with CONFIG_SYS_I2C_TEGRA
2088 - This driver adds 4 i2c buses with a fix speed from
2089 100000 and the slave addr 0!
2091 - drivers/i2c/ppc4xx_i2c.c
2092 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2093 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2094 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2096 - drivers/i2c/i2c_mxc.c
2097 - activate this driver with CONFIG_SYS_I2C_MXC
2098 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2099 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2100 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2101 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2102 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2103 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2104 If thoses defines are not set, default value is 100000
2105 for speed, and 0 for slave.
2107 - drivers/i2c/rcar_i2c.c:
2108 - activate this driver with CONFIG_SYS_I2C_RCAR
2109 - This driver adds 4 i2c buses
2111 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2112 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2113 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2114 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2115 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2116 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2117 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2118 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2119 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2121 - drivers/i2c/sh_i2c.c:
2122 - activate this driver with CONFIG_SYS_I2C_SH
2123 - This driver adds from 2 to 5 i2c buses
2125 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2126 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2127 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2128 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2129 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2130 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2131 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2132 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2133 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2134 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2135 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2136 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2137 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2139 - drivers/i2c/omap24xx_i2c.c
2140 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2141 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2142 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2143 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2144 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2145 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2146 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2147 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2148 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2149 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2150 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2152 - drivers/i2c/zynq_i2c.c
2153 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2154 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2155 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2157 - drivers/i2c/s3c24x0_i2c.c:
2158 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2159 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2160 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2161 with a fix speed from 100000 and the slave addr 0!
2165 CONFIG_SYS_NUM_I2C_BUSES
2166 Hold the number of i2c busses you want to use. If you
2167 don't use/have i2c muxes on your i2c bus, this
2168 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2171 CONFIG_SYS_I2C_DIRECT_BUS
2172 define this, if you don't use i2c muxes on your hardware.
2173 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2176 CONFIG_SYS_I2C_MAX_HOPS
2177 define how many muxes are maximal consecutively connected
2178 on one i2c bus. If you not use i2c muxes, omit this
2181 CONFIG_SYS_I2C_BUSES
2182 hold a list of busses you want to use, only used if
2183 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2184 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2185 CONFIG_SYS_NUM_I2C_BUSES = 9:
2187 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2188 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2189 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2190 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2191 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2192 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2193 {1, {I2C_NULL_HOP}}, \
2194 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2195 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2199 bus 0 on adapter 0 without a mux
2200 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2201 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2202 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2203 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2204 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2205 bus 6 on adapter 1 without a mux
2206 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2207 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2209 If you do not have i2c muxes on your board, omit this define.
2211 - Legacy I2C Support: CONFIG_HARD_I2C
2213 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2214 provides the following compelling advantages:
2216 - more than one i2c adapter is usable
2217 - approved multibus support
2218 - better i2c mux support
2220 ** Please consider updating your I2C driver now. **
2222 These enable legacy I2C serial bus commands. Defining
2223 CONFIG_HARD_I2C will include the appropriate I2C driver
2224 for the selected CPU.
2226 This will allow you to use i2c commands at the u-boot
2227 command line (as long as you set CONFIG_CMD_I2C in
2228 CONFIG_COMMANDS) and communicate with i2c based realtime
2229 clock chips. See common/cmd_i2c.c for a description of the
2230 command line interface.
2232 CONFIG_HARD_I2C selects a hardware I2C controller.
2234 There are several other quantities that must also be
2235 defined when you define CONFIG_HARD_I2C.
2237 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2238 to be the frequency (in Hz) at which you wish your i2c bus
2239 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2240 the CPU's i2c node address).
2242 Now, the u-boot i2c code for the mpc8xx
2243 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2244 and so its address should therefore be cleared to 0 (See,
2245 eg, MPC823e User's Manual p.16-473). So, set
2246 CONFIG_SYS_I2C_SLAVE to 0.
2248 CONFIG_SYS_I2C_INIT_MPC5XXX
2250 When a board is reset during an i2c bus transfer
2251 chips might think that the current transfer is still
2252 in progress. Reset the slave devices by sending start
2253 commands until the slave device responds.
2255 That's all that's required for CONFIG_HARD_I2C.
2257 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2258 then the following macros need to be defined (examples are
2259 from include/configs/lwmon.h):
2263 (Optional). Any commands necessary to enable the I2C
2264 controller or configure ports.
2266 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2270 (Only for MPC8260 CPU). The I/O port to use (the code
2271 assumes both bits are on the same port). Valid values
2272 are 0..3 for ports A..D.
2276 The code necessary to make the I2C data line active
2277 (driven). If the data line is open collector, this
2280 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2284 The code necessary to make the I2C data line tri-stated
2285 (inactive). If the data line is open collector, this
2288 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2292 Code that returns true if the I2C data line is high,
2295 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2299 If <bit> is true, sets the I2C data line high. If it
2300 is false, it clears it (low).
2302 eg: #define I2C_SDA(bit) \
2303 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2304 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2308 If <bit> is true, sets the I2C clock line high. If it
2309 is false, it clears it (low).
2311 eg: #define I2C_SCL(bit) \
2312 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2313 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2317 This delay is invoked four times per clock cycle so this
2318 controls the rate of data transfer. The data rate thus
2319 is 1 / (I2C_DELAY * 4). Often defined to be something
2322 #define I2C_DELAY udelay(2)
2324 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2326 If your arch supports the generic GPIO framework (asm/gpio.h),
2327 then you may alternatively define the two GPIOs that are to be
2328 used as SCL / SDA. Any of the previous I2C_xxx macros will
2329 have GPIO-based defaults assigned to them as appropriate.
2331 You should define these to the GPIO value as given directly to
2332 the generic GPIO functions.
2334 CONFIG_SYS_I2C_INIT_BOARD
2336 When a board is reset during an i2c bus transfer
2337 chips might think that the current transfer is still
2338 in progress. On some boards it is possible to access
2339 the i2c SCLK line directly, either by using the
2340 processor pin as a GPIO or by having a second pin
2341 connected to the bus. If this option is defined a
2342 custom i2c_init_board() routine in boards/xxx/board.c
2343 is run early in the boot sequence.
2345 CONFIG_SYS_I2C_BOARD_LATE_INIT
2347 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2348 defined a custom i2c_board_late_init() routine in
2349 boards/xxx/board.c is run AFTER the operations in i2c_init()
2350 is completed. This callpoint can be used to unreset i2c bus
2351 using CPU i2c controller register accesses for CPUs whose i2c
2352 controller provide such a method. It is called at the end of
2353 i2c_init() to allow i2c_init operations to setup the i2c bus
2354 controller on the CPU (e.g. setting bus speed & slave address).
2356 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2358 This option enables configuration of bi_iic_fast[] flags
2359 in u-boot bd_info structure based on u-boot environment
2360 variable "i2cfast". (see also i2cfast)
2362 CONFIG_I2C_MULTI_BUS
2364 This option allows the use of multiple I2C buses, each of which
2365 must have a controller. At any point in time, only one bus is
2366 active. To switch to a different bus, use the 'i2c dev' command.
2367 Note that bus numbering is zero-based.
2369 CONFIG_SYS_I2C_NOPROBES
2371 This option specifies a list of I2C devices that will be skipped
2372 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2373 is set, specify a list of bus-device pairs. Otherwise, specify
2374 a 1D array of device addresses
2377 #undef CONFIG_I2C_MULTI_BUS
2378 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2380 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2382 #define CONFIG_I2C_MULTI_BUS
2383 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2385 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2387 CONFIG_SYS_SPD_BUS_NUM
2389 If defined, then this indicates the I2C bus number for DDR SPD.
2390 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2392 CONFIG_SYS_RTC_BUS_NUM
2394 If defined, then this indicates the I2C bus number for the RTC.
2395 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2397 CONFIG_SYS_DTT_BUS_NUM
2399 If defined, then this indicates the I2C bus number for the DTT.
2400 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2402 CONFIG_SYS_I2C_DTT_ADDR:
2404 If defined, specifies the I2C address of the DTT device.
2405 If not defined, then U-Boot uses predefined value for
2406 specified DTT device.
2408 CONFIG_SOFT_I2C_READ_REPEATED_START
2410 defining this will force the i2c_read() function in
2411 the soft_i2c driver to perform an I2C repeated start
2412 between writing the address pointer and reading the
2413 data. If this define is omitted the default behaviour
2414 of doing a stop-start sequence will be used. Most I2C
2415 devices can use either method, but some require one or
2418 - SPI Support: CONFIG_SPI
2420 Enables SPI driver (so far only tested with
2421 SPI EEPROM, also an instance works with Crystal A/D and
2422 D/As on the SACSng board)
2426 Enables the driver for SPI controller on SuperH. Currently
2427 only SH7757 is supported.
2431 Enables extended (16-bit) SPI EEPROM addressing.
2432 (symmetrical to CONFIG_I2C_X)
2436 Enables a software (bit-bang) SPI driver rather than
2437 using hardware support. This is a general purpose
2438 driver that only requires three general I/O port pins
2439 (two outputs, one input) to function. If this is
2440 defined, the board configuration must define several
2441 SPI configuration items (port pins to use, etc). For
2442 an example, see include/configs/sacsng.h.
2446 Enables a hardware SPI driver for general-purpose reads
2447 and writes. As with CONFIG_SOFT_SPI, the board configuration
2448 must define a list of chip-select function pointers.
2449 Currently supported on some MPC8xxx processors. For an
2450 example, see include/configs/mpc8349emds.h.
2454 Enables the driver for the SPI controllers on i.MX and MXC
2455 SoCs. Currently i.MX31/35/51 are supported.
2457 - FPGA Support: CONFIG_FPGA
2459 Enables FPGA subsystem.
2461 CONFIG_FPGA_<vendor>
2463 Enables support for specific chip vendors.
2466 CONFIG_FPGA_<family>
2468 Enables support for FPGA family.
2469 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2473 Specify the number of FPGA devices to support.
2475 CONFIG_SYS_FPGA_PROG_FEEDBACK
2477 Enable printing of hash marks during FPGA configuration.
2479 CONFIG_SYS_FPGA_CHECK_BUSY
2481 Enable checks on FPGA configuration interface busy
2482 status by the configuration function. This option
2483 will require a board or device specific function to
2488 If defined, a function that provides delays in the FPGA
2489 configuration driver.
2491 CONFIG_SYS_FPGA_CHECK_CTRLC
2492 Allow Control-C to interrupt FPGA configuration
2494 CONFIG_SYS_FPGA_CHECK_ERROR
2496 Check for configuration errors during FPGA bitfile
2497 loading. For example, abort during Virtex II
2498 configuration if the INIT_B line goes low (which
2499 indicated a CRC error).
2501 CONFIG_SYS_FPGA_WAIT_INIT
2503 Maximum time to wait for the INIT_B line to deassert
2504 after PROB_B has been deasserted during a Virtex II
2505 FPGA configuration sequence. The default time is 500
2508 CONFIG_SYS_FPGA_WAIT_BUSY
2510 Maximum time to wait for BUSY to deassert during
2511 Virtex II FPGA configuration. The default is 5 ms.
2513 CONFIG_SYS_FPGA_WAIT_CONFIG
2515 Time to wait after FPGA configuration. The default is
2518 - Configuration Management:
2521 If defined, this string will be added to the U-Boot
2522 version information (U_BOOT_VERSION)
2524 - Vendor Parameter Protection:
2526 U-Boot considers the values of the environment
2527 variables "serial#" (Board Serial Number) and
2528 "ethaddr" (Ethernet Address) to be parameters that
2529 are set once by the board vendor / manufacturer, and
2530 protects these variables from casual modification by
2531 the user. Once set, these variables are read-only,
2532 and write or delete attempts are rejected. You can
2533 change this behaviour:
2535 If CONFIG_ENV_OVERWRITE is #defined in your config
2536 file, the write protection for vendor parameters is
2537 completely disabled. Anybody can change or delete
2540 Alternatively, if you #define _both_ CONFIG_ETHADDR
2541 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2542 Ethernet address is installed in the environment,
2543 which can be changed exactly ONCE by the user. [The
2544 serial# is unaffected by this, i. e. it remains
2547 The same can be accomplished in a more flexible way
2548 for any variable by configuring the type of access
2549 to allow for those variables in the ".flags" variable
2550 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2555 Define this variable to enable the reservation of
2556 "protected RAM", i. e. RAM which is not overwritten
2557 by U-Boot. Define CONFIG_PRAM to hold the number of
2558 kB you want to reserve for pRAM. You can overwrite
2559 this default value by defining an environment
2560 variable "pram" to the number of kB you want to
2561 reserve. Note that the board info structure will
2562 still show the full amount of RAM. If pRAM is
2563 reserved, a new environment variable "mem" will
2564 automatically be defined to hold the amount of
2565 remaining RAM in a form that can be passed as boot
2566 argument to Linux, for instance like that:
2568 setenv bootargs ... mem=\${mem}
2571 This way you can tell Linux not to use this memory,
2572 either, which results in a memory region that will
2573 not be affected by reboots.
2575 *WARNING* If your board configuration uses automatic
2576 detection of the RAM size, you must make sure that
2577 this memory test is non-destructive. So far, the
2578 following board configurations are known to be
2581 IVMS8, IVML24, SPD8xx, TQM8xxL,
2582 HERMES, IP860, RPXlite, LWMON,
2585 - Access to physical memory region (> 4GB)
2586 Some basic support is provided for operations on memory not
2587 normally accessible to U-Boot - e.g. some architectures
2588 support access to more than 4GB of memory on 32-bit
2589 machines using physical address extension or similar.
2590 Define CONFIG_PHYSMEM to access this basic support, which
2591 currently only supports clearing the memory.
2596 Define this variable to stop the system in case of a
2597 fatal error, so that you have to reset it manually.
2598 This is probably NOT a good idea for an embedded
2599 system where you want the system to reboot
2600 automatically as fast as possible, but it may be
2601 useful during development since you can try to debug
2602 the conditions that lead to the situation.
2604 CONFIG_NET_RETRY_COUNT
2606 This variable defines the number of retries for
2607 network operations like ARP, RARP, TFTP, or BOOTP
2608 before giving up the operation. If not defined, a
2609 default value of 5 is used.
2613 Timeout waiting for an ARP reply in milliseconds.
2617 Timeout in milliseconds used in NFS protocol.
2618 If you encounter "ERROR: Cannot umount" in nfs command,
2619 try longer timeout such as
2620 #define CONFIG_NFS_TIMEOUT 10000UL
2622 - Command Interpreter:
2623 CONFIG_AUTO_COMPLETE
2625 Enable auto completion of commands using TAB.
2627 Note that this feature has NOT been implemented yet
2628 for the "hush" shell.
2631 CONFIG_SYS_HUSH_PARSER
2633 Define this variable to enable the "hush" shell (from
2634 Busybox) as command line interpreter, thus enabling
2635 powerful command line syntax like
2636 if...then...else...fi conditionals or `&&' and '||'
2637 constructs ("shell scripts").
2639 If undefined, you get the old, much simpler behaviour
2640 with a somewhat smaller memory footprint.
2643 CONFIG_SYS_PROMPT_HUSH_PS2
2645 This defines the secondary prompt string, which is
2646 printed when the command interpreter needs more input
2647 to complete a command. Usually "> ".
2651 In the current implementation, the local variables
2652 space and global environment variables space are
2653 separated. Local variables are those you define by
2654 simply typing `name=value'. To access a local
2655 variable later on, you have write `$name' or
2656 `${name}'; to execute the contents of a variable
2657 directly type `$name' at the command prompt.
2659 Global environment variables are those you use
2660 setenv/printenv to work with. To run a command stored
2661 in such a variable, you need to use the run command,
2662 and you must not use the '$' sign to access them.
2664 To store commands and special characters in a
2665 variable, please use double quotation marks
2666 surrounding the whole text of the variable, instead
2667 of the backslashes before semicolons and special
2670 - Commandline Editing and History:
2671 CONFIG_CMDLINE_EDITING
2673 Enable editing and History functions for interactive
2674 commandline input operations
2676 - Default Environment:
2677 CONFIG_EXTRA_ENV_SETTINGS
2679 Define this to contain any number of null terminated
2680 strings (variable = value pairs) that will be part of
2681 the default environment compiled into the boot image.
2683 For example, place something like this in your
2684 board's config file:
2686 #define CONFIG_EXTRA_ENV_SETTINGS \
2690 Warning: This method is based on knowledge about the
2691 internal format how the environment is stored by the
2692 U-Boot code. This is NOT an official, exported
2693 interface! Although it is unlikely that this format
2694 will change soon, there is no guarantee either.
2695 You better know what you are doing here.
2697 Note: overly (ab)use of the default environment is
2698 discouraged. Make sure to check other ways to preset
2699 the environment like the "source" command or the
2702 CONFIG_ENV_VARS_UBOOT_CONFIG
2704 Define this in order to add variables describing the
2705 U-Boot build configuration to the default environment.
2706 These will be named arch, cpu, board, vendor, and soc.
2708 Enabling this option will cause the following to be defined:
2716 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2718 Define this in order to add variables describing certain
2719 run-time determined information about the hardware to the
2720 environment. These will be named board_name, board_rev.
2722 CONFIG_DELAY_ENVIRONMENT
2724 Normally the environment is loaded when the board is
2725 intialised so that it is available to U-Boot. This inhibits
2726 that so that the environment is not available until
2727 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2728 this is instead controlled by the value of
2729 /config/load-environment.
2731 - DataFlash Support:
2732 CONFIG_HAS_DATAFLASH
2734 Defining this option enables DataFlash features and
2735 allows to read/write in Dataflash via the standard
2738 - Serial Flash support
2741 Defining this option enables SPI flash commands
2742 'sf probe/read/write/erase/update'.
2744 Usage requires an initial 'probe' to define the serial
2745 flash parameters, followed by read/write/erase/update
2748 The following defaults may be provided by the platform
2749 to handle the common case when only a single serial
2750 flash is present on the system.
2752 CONFIG_SF_DEFAULT_BUS Bus identifier
2753 CONFIG_SF_DEFAULT_CS Chip-select
2754 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2755 CONFIG_SF_DEFAULT_SPEED in Hz
2759 Define this option to include a destructive SPI flash
2762 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2764 Define this option to use the Bank addr/Extended addr
2765 support on SPI flashes which has size > 16Mbytes.
2767 CONFIG_SF_DUAL_FLASH Dual flash memories
2769 Define this option to use dual flash support where two flash
2770 memories can be connected with a given cs line.
2771 currently Xilinx Zynq qspi support these type of connections.
2773 - SystemACE Support:
2776 Adding this option adds support for Xilinx SystemACE
2777 chips attached via some sort of local bus. The address
2778 of the chip must also be defined in the
2779 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2781 #define CONFIG_SYSTEMACE
2782 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2784 When SystemACE support is added, the "ace" device type
2785 becomes available to the fat commands, i.e. fatls.
2787 - TFTP Fixed UDP Port:
2790 If this is defined, the environment variable tftpsrcp
2791 is used to supply the TFTP UDP source port value.
2792 If tftpsrcp isn't defined, the normal pseudo-random port
2793 number generator is used.
2795 Also, the environment variable tftpdstp is used to supply
2796 the TFTP UDP destination port value. If tftpdstp isn't
2797 defined, the normal port 69 is used.
2799 The purpose for tftpsrcp is to allow a TFTP server to
2800 blindly start the TFTP transfer using the pre-configured
2801 target IP address and UDP port. This has the effect of
2802 "punching through" the (Windows XP) firewall, allowing
2803 the remainder of the TFTP transfer to proceed normally.
2804 A better solution is to properly configure the firewall,
2805 but sometimes that is not allowed.
2810 This enables a generic 'hash' command which can produce
2811 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2815 Enable the hash verify command (hash -v). This adds to code
2818 CONFIG_SHA1 - support SHA1 hashing
2819 CONFIG_SHA256 - support SHA256 hashing
2821 Note: There is also a sha1sum command, which should perhaps
2822 be deprecated in favour of 'hash sha1'.
2824 - Freescale i.MX specific commands:
2825 CONFIG_CMD_HDMIDETECT
2826 This enables 'hdmidet' command which returns true if an
2827 HDMI monitor is detected. This command is i.MX 6 specific.
2830 This enables the 'bmode' (bootmode) command for forcing
2831 a boot from specific media.
2833 This is useful for forcing the ROM's usb downloader to
2834 activate upon a watchdog reset which is nice when iterating
2835 on U-Boot. Using the reset button or running bmode normal
2836 will set it back to normal. This command currently
2837 supports i.MX53 and i.MX6.
2842 This enables the RSA algorithm used for FIT image verification
2843 in U-Boot. See doc/uImage/signature for more information.
2845 The signing part is build into mkimage regardless of this
2849 - Show boot progress:
2850 CONFIG_SHOW_BOOT_PROGRESS
2852 Defining this option allows to add some board-
2853 specific code (calling a user-provided function
2854 "show_boot_progress(int)") that enables you to show
2855 the system's boot progress on some display (for
2856 example, some LED's) on your board. At the moment,
2857 the following checkpoints are implemented:
2859 - Detailed boot stage timing
2861 Define this option to get detailed timing of each stage
2862 of the boot process.
2864 CONFIG_BOOTSTAGE_USER_COUNT
2865 This is the number of available user bootstage records.
2866 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2867 a new ID will be allocated from this stash. If you exceed
2868 the limit, recording will stop.
2870 CONFIG_BOOTSTAGE_REPORT
2871 Define this to print a report before boot, similar to this:
2873 Timer summary in microseconds:
2876 3,575,678 3,575,678 board_init_f start
2877 3,575,695 17 arch_cpu_init A9
2878 3,575,777 82 arch_cpu_init done
2879 3,659,598 83,821 board_init_r start
2880 3,910,375 250,777 main_loop
2881 29,916,167 26,005,792 bootm_start
2882 30,361,327 445,160 start_kernel
2884 CONFIG_CMD_BOOTSTAGE
2885 Add a 'bootstage' command which supports printing a report
2886 and un/stashing of bootstage data.
2888 CONFIG_BOOTSTAGE_FDT
2889 Stash the bootstage information in the FDT. A root 'bootstage'
2890 node is created with each bootstage id as a child. Each child
2891 has a 'name' property and either 'mark' containing the
2892 mark time in microsecond, or 'accum' containing the
2893 accumulated time for that bootstage id in microseconds.
2898 name = "board_init_f";
2907 Code in the Linux kernel can find this in /proc/devicetree.
2909 Legacy uImage format:
2912 1 common/cmd_bootm.c before attempting to boot an image
2913 -1 common/cmd_bootm.c Image header has bad magic number
2914 2 common/cmd_bootm.c Image header has correct magic number
2915 -2 common/cmd_bootm.c Image header has bad checksum
2916 3 common/cmd_bootm.c Image header has correct checksum
2917 -3 common/cmd_bootm.c Image data has bad checksum
2918 4 common/cmd_bootm.c Image data has correct checksum
2919 -4 common/cmd_bootm.c Image is for unsupported architecture
2920 5 common/cmd_bootm.c Architecture check OK
2921 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2922 6 common/cmd_bootm.c Image Type check OK
2923 -6 common/cmd_bootm.c gunzip uncompression error
2924 -7 common/cmd_bootm.c Unimplemented compression type
2925 7 common/cmd_bootm.c Uncompression OK
2926 8 common/cmd_bootm.c No uncompress/copy overwrite error
2927 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2929 9 common/image.c Start initial ramdisk verification
2930 -10 common/image.c Ramdisk header has bad magic number
2931 -11 common/image.c Ramdisk header has bad checksum
2932 10 common/image.c Ramdisk header is OK
2933 -12 common/image.c Ramdisk data has bad checksum
2934 11 common/image.c Ramdisk data has correct checksum
2935 12 common/image.c Ramdisk verification complete, start loading
2936 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2937 13 common/image.c Start multifile image verification
2938 14 common/image.c No initial ramdisk, no multifile, continue.
2940 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2942 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2943 -31 post/post.c POST test failed, detected by post_output_backlog()
2944 -32 post/post.c POST test failed, detected by post_run_single()
2946 34 common/cmd_doc.c before loading a Image from a DOC device
2947 -35 common/cmd_doc.c Bad usage of "doc" command
2948 35 common/cmd_doc.c correct usage of "doc" command
2949 -36 common/cmd_doc.c No boot device
2950 36 common/cmd_doc.c correct boot device
2951 -37 common/cmd_doc.c Unknown Chip ID on boot device
2952 37 common/cmd_doc.c correct chip ID found, device available
2953 -38 common/cmd_doc.c Read Error on boot device
2954 38 common/cmd_doc.c reading Image header from DOC device OK
2955 -39 common/cmd_doc.c Image header has bad magic number
2956 39 common/cmd_doc.c Image header has correct magic number
2957 -40 common/cmd_doc.c Error reading Image from DOC device
2958 40 common/cmd_doc.c Image header has correct magic number
2959 41 common/cmd_ide.c before loading a Image from a IDE device
2960 -42 common/cmd_ide.c Bad usage of "ide" command
2961 42 common/cmd_ide.c correct usage of "ide" command
2962 -43 common/cmd_ide.c No boot device
2963 43 common/cmd_ide.c boot device found
2964 -44 common/cmd_ide.c Device not available
2965 44 common/cmd_ide.c Device available
2966 -45 common/cmd_ide.c wrong partition selected
2967 45 common/cmd_ide.c partition selected
2968 -46 common/cmd_ide.c Unknown partition table
2969 46 common/cmd_ide.c valid partition table found
2970 -47 common/cmd_ide.c Invalid partition type
2971 47 common/cmd_ide.c correct partition type
2972 -48 common/cmd_ide.c Error reading Image Header on boot device
2973 48 common/cmd_ide.c reading Image Header from IDE device OK
2974 -49 common/cmd_ide.c Image header has bad magic number
2975 49 common/cmd_ide.c Image header has correct magic number
2976 -50 common/cmd_ide.c Image header has bad checksum
2977 50 common/cmd_ide.c Image header has correct checksum
2978 -51 common/cmd_ide.c Error reading Image from IDE device
2979 51 common/cmd_ide.c reading Image from IDE device OK
2980 52 common/cmd_nand.c before loading a Image from a NAND device
2981 -53 common/cmd_nand.c Bad usage of "nand" command
2982 53 common/cmd_nand.c correct usage of "nand" command
2983 -54 common/cmd_nand.c No boot device
2984 54 common/cmd_nand.c boot device found
2985 -55 common/cmd_nand.c Unknown Chip ID on boot device
2986 55 common/cmd_nand.c correct chip ID found, device available
2987 -56 common/cmd_nand.c Error reading Image Header on boot device
2988 56 common/cmd_nand.c reading Image Header from NAND device OK
2989 -57 common/cmd_nand.c Image header has bad magic number
2990 57 common/cmd_nand.c Image header has correct magic number
2991 -58 common/cmd_nand.c Error reading Image from NAND device
2992 58 common/cmd_nand.c reading Image from NAND device OK
2994 -60 common/env_common.c Environment has a bad CRC, using default
2996 64 net/eth.c starting with Ethernet configuration.
2997 -64 net/eth.c no Ethernet found.
2998 65 net/eth.c Ethernet found.
3000 -80 common/cmd_net.c usage wrong
3001 80 common/cmd_net.c before calling NetLoop()
3002 -81 common/cmd_net.c some error in NetLoop() occurred
3003 81 common/cmd_net.c NetLoop() back without error
3004 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3005 82 common/cmd_net.c trying automatic boot
3006 83 common/cmd_net.c running "source" command
3007 -83 common/cmd_net.c some error in automatic boot or "source" command
3008 84 common/cmd_net.c end without errors
3013 100 common/cmd_bootm.c Kernel FIT Image has correct format
3014 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3015 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3016 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3017 102 common/cmd_bootm.c Kernel unit name specified
3018 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3019 103 common/cmd_bootm.c Found configuration node
3020 104 common/cmd_bootm.c Got kernel subimage node offset
3021 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3022 105 common/cmd_bootm.c Kernel subimage hash verification OK
3023 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3024 106 common/cmd_bootm.c Architecture check OK
3025 -106 common/cmd_bootm.c Kernel subimage has wrong type
3026 107 common/cmd_bootm.c Kernel subimage type OK
3027 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3028 108 common/cmd_bootm.c Got kernel subimage data/size
3029 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3030 -109 common/cmd_bootm.c Can't get kernel subimage type
3031 -110 common/cmd_bootm.c Can't get kernel subimage comp
3032 -111 common/cmd_bootm.c Can't get kernel subimage os
3033 -112 common/cmd_bootm.c Can't get kernel subimage load address
3034 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3036 120 common/image.c Start initial ramdisk verification
3037 -120 common/image.c Ramdisk FIT image has incorrect format
3038 121 common/image.c Ramdisk FIT image has correct format
3039 122 common/image.c No ramdisk subimage unit name, using configuration
3040 -122 common/image.c Can't get configuration for ramdisk subimage
3041 123 common/image.c Ramdisk unit name specified
3042 -124 common/image.c Can't get ramdisk subimage node offset
3043 125 common/image.c Got ramdisk subimage node offset
3044 -125 common/image.c Ramdisk subimage hash verification failed
3045 126 common/image.c Ramdisk subimage hash verification OK
3046 -126 common/image.c Ramdisk subimage for unsupported architecture
3047 127 common/image.c Architecture check OK
3048 -127 common/image.c Can't get ramdisk subimage data/size
3049 128 common/image.c Got ramdisk subimage data/size
3050 129 common/image.c Can't get ramdisk load address
3051 -129 common/image.c Got ramdisk load address
3053 -130 common/cmd_doc.c Incorrect FIT image format
3054 131 common/cmd_doc.c FIT image format OK
3056 -140 common/cmd_ide.c Incorrect FIT image format
3057 141 common/cmd_ide.c FIT image format OK
3059 -150 common/cmd_nand.c Incorrect FIT image format
3060 151 common/cmd_nand.c FIT image format OK
3062 - FIT image support:
3064 Enable support for the FIT uImage format.
3066 CONFIG_FIT_BEST_MATCH
3067 When no configuration is explicitly selected, default to the
3068 one whose fdt's compatibility field best matches that of
3069 U-Boot itself. A match is considered "best" if it matches the
3070 most specific compatibility entry of U-Boot's fdt's root node.
3071 The order of entries in the configuration's fdt is ignored.
3073 CONFIG_FIT_SIGNATURE
3074 This option enables signature verification of FIT uImages,
3075 using a hash signed and verified using RSA. See
3076 doc/uImage.FIT/signature.txt for more details.
3078 - Standalone program support:
3079 CONFIG_STANDALONE_LOAD_ADDR
3081 This option defines a board specific value for the
3082 address where standalone program gets loaded, thus
3083 overwriting the architecture dependent default
3086 - Frame Buffer Address:
3089 Define CONFIG_FB_ADDR if you want to use specific
3090 address for frame buffer. This is typically the case
3091 when using a graphics controller has separate video
3092 memory. U-Boot will then place the frame buffer at
3093 the given address instead of dynamically reserving it
3094 in system RAM by calling lcd_setmem(), which grabs
3095 the memory for the frame buffer depending on the
3096 configured panel size.
3098 Please see board_init_f function.
3100 - Automatic software updates via TFTP server
3102 CONFIG_UPDATE_TFTP_CNT_MAX
3103 CONFIG_UPDATE_TFTP_MSEC_MAX
3105 These options enable and control the auto-update feature;
3106 for a more detailed description refer to doc/README.update.
3108 - MTD Support (mtdparts command, UBI support)
3111 Adds the MTD device infrastructure from the Linux kernel.
3112 Needed for mtdparts command support.
3114 CONFIG_MTD_PARTITIONS
3116 Adds the MTD partitioning infrastructure from the Linux
3117 kernel. Needed for UBI support.
3122 Adds commands for interacting with MTD partitions formatted
3123 with the UBI flash translation layer
3125 Requires also defining CONFIG_RBTREE
3127 CONFIG_UBI_SILENCE_MSG
3129 Make the verbose messages from UBI stop printing. This leaves
3130 warnings and errors enabled.
3135 Adds commands for interacting with UBI volumes formatted as
3136 UBIFS. UBIFS is read-only in u-boot.
3138 Requires UBI support as well as CONFIG_LZO
3140 CONFIG_UBIFS_SILENCE_MSG
3142 Make the verbose messages from UBIFS stop printing. This leaves
3143 warnings and errors enabled.
3147 Enable building of SPL globally.
3150 LDSCRIPT for linking the SPL binary.
3152 CONFIG_SPL_MAX_FOOTPRINT
3153 Maximum size in memory allocated to the SPL, BSS included.
3154 When defined, the linker checks that the actual memory
3155 used by SPL from _start to __bss_end does not exceed it.
3156 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3157 must not be both defined at the same time.
3160 Maximum size of the SPL image (text, data, rodata, and
3161 linker lists sections), BSS excluded.
3162 When defined, the linker checks that the actual size does
3165 CONFIG_SPL_TEXT_BASE
3166 TEXT_BASE for linking the SPL binary.
3168 CONFIG_SPL_RELOC_TEXT_BASE
3169 Address to relocate to. If unspecified, this is equal to
3170 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3172 CONFIG_SPL_BSS_START_ADDR
3173 Link address for the BSS within the SPL binary.
3175 CONFIG_SPL_BSS_MAX_SIZE
3176 Maximum size in memory allocated to the SPL BSS.
3177 When defined, the linker checks that the actual memory used
3178 by SPL from __bss_start to __bss_end does not exceed it.
3179 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3180 must not be both defined at the same time.
3183 Adress of the start of the stack SPL will use
3185 CONFIG_SPL_RELOC_STACK
3186 Adress of the start of the stack SPL will use after
3187 relocation. If unspecified, this is equal to
3190 CONFIG_SYS_SPL_MALLOC_START
3191 Starting address of the malloc pool used in SPL.
3193 CONFIG_SYS_SPL_MALLOC_SIZE
3194 The size of the malloc pool used in SPL.
3196 CONFIG_SPL_FRAMEWORK
3197 Enable the SPL framework under common/. This framework
3198 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3199 NAND loading of the Linux Kernel.
3201 CONFIG_SPL_DISPLAY_PRINT
3202 For ARM, enable an optional function to print more information
3203 about the running system.
3205 CONFIG_SPL_INIT_MINIMAL
3206 Arch init code should be built for a very small image
3208 CONFIG_SPL_LIBCOMMON_SUPPORT
3209 Support for common/libcommon.o in SPL binary
3211 CONFIG_SPL_LIBDISK_SUPPORT
3212 Support for disk/libdisk.o in SPL binary
3214 CONFIG_SPL_I2C_SUPPORT
3215 Support for drivers/i2c/libi2c.o in SPL binary
3217 CONFIG_SPL_GPIO_SUPPORT
3218 Support for drivers/gpio/libgpio.o in SPL binary
3220 CONFIG_SPL_MMC_SUPPORT
3221 Support for drivers/mmc/libmmc.o in SPL binary
3223 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3224 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3225 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3226 Address, size and partition on the MMC to load U-Boot from
3227 when the MMC is being used in raw mode.
3229 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3230 Sector to load kernel uImage from when MMC is being
3231 used in raw mode (for Falcon mode)
3233 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3234 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3235 Sector and number of sectors to load kernel argument
3236 parameters from when MMC is being used in raw mode
3239 CONFIG_SPL_FAT_SUPPORT
3240 Support for fs/fat/libfat.o in SPL binary
3242 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3243 Filename to read to load U-Boot when reading from FAT
3245 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3246 Filename to read to load kernel uImage when reading
3247 from FAT (for Falcon mode)
3249 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3250 Filename to read to load kernel argument parameters
3251 when reading from FAT (for Falcon mode)
3253 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3254 Set this for NAND SPL on PPC mpc83xx targets, so that
3255 start.S waits for the rest of the SPL to load before
3256 continuing (the hardware starts execution after just
3257 loading the first page rather than the full 4K).
3259 CONFIG_SPL_NAND_BASE
3260 Include nand_base.c in the SPL. Requires
3261 CONFIG_SPL_NAND_DRIVERS.
3263 CONFIG_SPL_NAND_DRIVERS
3264 SPL uses normal NAND drivers, not minimal drivers.
3267 Include standard software ECC in the SPL
3269 CONFIG_SPL_NAND_SIMPLE
3270 Support for NAND boot using simple NAND drivers that
3271 expose the cmd_ctrl() interface.
3273 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3274 Set for the SPL on PPC mpc8xxx targets, support for
3275 drivers/ddr/fsl/libddr.o in SPL binary.
3277 CONFIG_SPL_COMMON_INIT_DDR
3278 Set for common ddr init with serial presence detect in
3281 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3282 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3283 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3284 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3285 CONFIG_SYS_NAND_ECCBYTES
3286 Defines the size and behavior of the NAND that SPL uses
3289 CONFIG_SPL_NAND_BOOT
3290 Add support NAND boot
3292 CONFIG_SYS_NAND_U_BOOT_OFFS
3293 Location in NAND to read U-Boot from
3295 CONFIG_SYS_NAND_U_BOOT_DST
3296 Location in memory to load U-Boot to
3298 CONFIG_SYS_NAND_U_BOOT_SIZE
3299 Size of image to load
3301 CONFIG_SYS_NAND_U_BOOT_START
3302 Entry point in loaded image to jump to
3304 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3305 Define this if you need to first read the OOB and then the
3306 data. This is used for example on davinci plattforms.
3308 CONFIG_SPL_OMAP3_ID_NAND
3309 Support for an OMAP3-specific set of functions to return the
3310 ID and MFR of the first attached NAND chip, if present.
3312 CONFIG_SPL_SERIAL_SUPPORT
3313 Support for drivers/serial/libserial.o in SPL binary
3315 CONFIG_SPL_SPI_FLASH_SUPPORT
3316 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3318 CONFIG_SPL_SPI_SUPPORT
3319 Support for drivers/spi/libspi.o in SPL binary
3321 CONFIG_SPL_RAM_DEVICE
3322 Support for running image already present in ram, in SPL binary
3324 CONFIG_SPL_LIBGENERIC_SUPPORT
3325 Support for lib/libgeneric.o in SPL binary
3327 CONFIG_SPL_ENV_SUPPORT
3328 Support for the environment operating in SPL binary
3330 CONFIG_SPL_NET_SUPPORT
3331 Support for the net/libnet.o in SPL binary.
3332 It conflicts with SPL env from storage medium specified by
3333 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3336 Image offset to which the SPL should be padded before appending
3337 the SPL payload. By default, this is defined as
3338 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3339 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3340 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3343 Final target image containing SPL and payload. Some SPLs
3344 use an arch-specific makefile fragment instead, for
3345 example if more than one image needs to be produced.
3347 CONFIG_FIT_SPL_PRINT
3348 Printing information about a FIT image adds quite a bit of
3349 code to SPL. So this is normally disabled in SPL. Use this
3350 option to re-enable it. This will affect the output of the
3351 bootm command when booting a FIT image.
3355 Enable building of TPL globally.
3358 Image offset to which the TPL should be padded before appending
3359 the TPL payload. By default, this is defined as
3360 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3361 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3362 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3367 [so far only for SMDK2400 boards]
3369 - Modem support enable:
3370 CONFIG_MODEM_SUPPORT
3372 - RTS/CTS Flow control enable:
3375 - Modem debug support:
3376 CONFIG_MODEM_SUPPORT_DEBUG
3378 Enables debugging stuff (char screen[1024], dbg())
3379 for modem support. Useful only with BDI2000.
3381 - Interrupt support (PPC):
3383 There are common interrupt_init() and timer_interrupt()
3384 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3385 for CPU specific initialization. interrupt_init_cpu()
3386 should set decrementer_count to appropriate value. If
3387 CPU resets decrementer automatically after interrupt
3388 (ppc4xx) it should set decrementer_count to zero.
3389 timer_interrupt() calls timer_interrupt_cpu() for CPU
3390 specific handling. If board has watchdog / status_led
3391 / other_activity_monitor it works automatically from
3392 general timer_interrupt().
3396 In the target system modem support is enabled when a
3397 specific key (key combination) is pressed during
3398 power-on. Otherwise U-Boot will boot normally
3399 (autoboot). The key_pressed() function is called from
3400 board_init(). Currently key_pressed() is a dummy
3401 function, returning 1 and thus enabling modem
3404 If there are no modem init strings in the
3405 environment, U-Boot proceed to autoboot; the
3406 previous output (banner, info printfs) will be
3409 See also: doc/README.Modem
3411 Board initialization settings:
3412 ------------------------------
3414 During Initialization u-boot calls a number of board specific functions
3415 to allow the preparation of board specific prerequisites, e.g. pin setup
3416 before drivers are initialized. To enable these callbacks the
3417 following configuration macros have to be defined. Currently this is
3418 architecture specific, so please check arch/your_architecture/lib/board.c
3419 typically in board_init_f() and board_init_r().
3421 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3422 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3423 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3424 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3426 Configuration Settings:
3427 -----------------------
3429 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3430 undefine this when you're short of memory.
3432 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3433 width of the commands listed in the 'help' command output.
3435 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3436 prompt for user input.
3438 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3440 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3442 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3444 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3445 the application (usually a Linux kernel) when it is
3448 - CONFIG_SYS_BAUDRATE_TABLE:
3449 List of legal baudrate settings for this board.
3451 - CONFIG_SYS_CONSOLE_INFO_QUIET
3452 Suppress display of console information at boot.
3454 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3455 If the board specific function
3456 extern int overwrite_console (void);
3457 returns 1, the stdin, stderr and stdout are switched to the
3458 serial port, else the settings in the environment are used.
3460 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3461 Enable the call to overwrite_console().
3463 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3464 Enable overwrite of previous console environment settings.
3466 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3467 Begin and End addresses of the area used by the
3470 - CONFIG_SYS_ALT_MEMTEST:
3471 Enable an alternate, more extensive memory test.
3473 - CONFIG_SYS_MEMTEST_SCRATCH:
3474 Scratch address used by the alternate memory test
3475 You only need to set this if address zero isn't writeable
3477 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3478 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3479 this specified memory area will get subtracted from the top
3480 (end) of RAM and won't get "touched" at all by U-Boot. By
3481 fixing up gd->ram_size the Linux kernel should gets passed
3482 the now "corrected" memory size and won't touch it either.
3483 This should work for arch/ppc and arch/powerpc. Only Linux
3484 board ports in arch/powerpc with bootwrapper support that
3485 recalculate the memory size from the SDRAM controller setup
3486 will have to get fixed in Linux additionally.
3488 This option can be used as a workaround for the 440EPx/GRx
3489 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3492 WARNING: Please make sure that this value is a multiple of
3493 the Linux page size (normally 4k). If this is not the case,
3494 then the end address of the Linux memory will be located at a
3495 non page size aligned address and this could cause major
3498 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3499 Enable temporary baudrate change while serial download
3501 - CONFIG_SYS_SDRAM_BASE:
3502 Physical start address of SDRAM. _Must_ be 0 here.
3504 - CONFIG_SYS_MBIO_BASE:
3505 Physical start address of Motherboard I/O (if using a
3508 - CONFIG_SYS_FLASH_BASE:
3509 Physical start address of Flash memory.
3511 - CONFIG_SYS_MONITOR_BASE:
3512 Physical start address of boot monitor code (set by
3513 make config files to be same as the text base address
3514 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3515 CONFIG_SYS_FLASH_BASE when booting from flash.
3517 - CONFIG_SYS_MONITOR_LEN:
3518 Size of memory reserved for monitor code, used to
3519 determine _at_compile_time_ (!) if the environment is
3520 embedded within the U-Boot image, or in a separate
3523 - CONFIG_SYS_MALLOC_LEN:
3524 Size of DRAM reserved for malloc() use.
3526 - CONFIG_SYS_BOOTM_LEN:
3527 Normally compressed uImages are limited to an
3528 uncompressed size of 8 MBytes. If this is not enough,
3529 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3530 to adjust this setting to your needs.
3532 - CONFIG_SYS_BOOTMAPSZ:
3533 Maximum size of memory mapped by the startup code of
3534 the Linux kernel; all data that must be processed by
3535 the Linux kernel (bd_info, boot arguments, FDT blob if
3536 used) must be put below this limit, unless "bootm_low"
3537 environment variable is defined and non-zero. In such case
3538 all data for the Linux kernel must be between "bootm_low"
3539 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3540 variable "bootm_mapsize" will override the value of
3541 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3542 then the value in "bootm_size" will be used instead.
3544 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3545 Enable initrd_high functionality. If defined then the
3546 initrd_high feature is enabled and the bootm ramdisk subcommand
3549 - CONFIG_SYS_BOOT_GET_CMDLINE:
3550 Enables allocating and saving kernel cmdline in space between
3551 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3553 - CONFIG_SYS_BOOT_GET_KBD:
3554 Enables allocating and saving a kernel copy of the bd_info in
3555 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3557 - CONFIG_SYS_MAX_FLASH_BANKS:
3558 Max number of Flash memory banks
3560 - CONFIG_SYS_MAX_FLASH_SECT:
3561 Max number of sectors on a Flash chip
3563 - CONFIG_SYS_FLASH_ERASE_TOUT:
3564 Timeout for Flash erase operations (in ms)
3566 - CONFIG_SYS_FLASH_WRITE_TOUT:
3567 Timeout for Flash write operations (in ms)
3569 - CONFIG_SYS_FLASH_LOCK_TOUT
3570 Timeout for Flash set sector lock bit operation (in ms)
3572 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3573 Timeout for Flash clear lock bits operation (in ms)
3575 - CONFIG_SYS_FLASH_PROTECTION
3576 If defined, hardware flash sectors protection is used
3577 instead of U-Boot software protection.
3579 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3581 Enable TFTP transfers directly to flash memory;
3582 without this option such a download has to be
3583 performed in two steps: (1) download to RAM, and (2)
3584 copy from RAM to flash.
3586 The two-step approach is usually more reliable, since
3587 you can check if the download worked before you erase
3588 the flash, but in some situations (when system RAM is
3589 too limited to allow for a temporary copy of the
3590 downloaded image) this option may be very useful.
3592 - CONFIG_SYS_FLASH_CFI:
3593 Define if the flash driver uses extra elements in the
3594 common flash structure for storing flash geometry.
3596 - CONFIG_FLASH_CFI_DRIVER
3597 This option also enables the building of the cfi_flash driver
3598 in the drivers directory
3600 - CONFIG_FLASH_CFI_MTD
3601 This option enables the building of the cfi_mtd driver
3602 in the drivers directory. The driver exports CFI flash
3605 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3606 Use buffered writes to flash.
3608 - CONFIG_FLASH_SPANSION_S29WS_N
3609 s29ws-n MirrorBit flash has non-standard addresses for buffered
3612 - CONFIG_SYS_FLASH_QUIET_TEST
3613 If this option is defined, the common CFI flash doesn't
3614 print it's warning upon not recognized FLASH banks. This
3615 is useful, if some of the configured banks are only
3616 optionally available.
3618 - CONFIG_FLASH_SHOW_PROGRESS
3619 If defined (must be an integer), print out countdown
3620 digits and dots. Recommended value: 45 (9..1) for 80
3621 column displays, 15 (3..1) for 40 column displays.
3623 - CONFIG_FLASH_VERIFY
3624 If defined, the content of the flash (destination) is compared
3625 against the source after the write operation. An error message
3626 will be printed when the contents are not identical.
3627 Please note that this option is useless in nearly all cases,
3628 since such flash programming errors usually are detected earlier
3629 while unprotecting/erasing/programming. Please only enable
3630 this option if you really know what you are doing.
3632 - CONFIG_SYS_RX_ETH_BUFFER:
3633 Defines the number of Ethernet receive buffers. On some
3634 Ethernet controllers it is recommended to set this value
3635 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3636 buffers can be full shortly after enabling the interface
3637 on high Ethernet traffic.
3638 Defaults to 4 if not defined.
3640 - CONFIG_ENV_MAX_ENTRIES
3642 Maximum number of entries in the hash table that is used
3643 internally to store the environment settings. The default
3644 setting is supposed to be generous and should work in most
3645 cases. This setting can be used to tune behaviour; see
3646 lib/hashtable.c for details.
3648 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3649 - CONFIG_ENV_FLAGS_LIST_STATIC
3650 Enable validation of the values given to environment variables when
3651 calling env set. Variables can be restricted to only decimal,
3652 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3653 the variables can also be restricted to IP address or MAC address.
3655 The format of the list is:
3656 type_attribute = [s|d|x|b|i|m]
3657 access_atribute = [a|r|o|c]
3658 attributes = type_attribute[access_atribute]
3659 entry = variable_name[:attributes]
3662 The type attributes are:
3663 s - String (default)
3666 b - Boolean ([1yYtT|0nNfF])
3670 The access attributes are:
3676 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3677 Define this to a list (string) to define the ".flags"
3678 envirnoment variable in the default or embedded environment.
3680 - CONFIG_ENV_FLAGS_LIST_STATIC
3681 Define this to a list (string) to define validation that
3682 should be done if an entry is not found in the ".flags"
3683 environment variable. To override a setting in the static
3684 list, simply add an entry for the same variable name to the
3687 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3688 If defined, don't allow the -f switch to env set override variable
3691 - CONFIG_SYS_GENERIC_BOARD
3692 This selects the architecture-generic board system instead of the
3693 architecture-specific board files. It is intended to move boards
3694 to this new framework over time. Defining this will disable the
3695 arch/foo/lib/board.c file and use common/board_f.c and
3696 common/board_r.c instead. To use this option your architecture
3697 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3698 its config.mk file). If you find problems enabling this option on
3699 your board please report the problem and send patches!
3701 - CONFIG_SYS_SYM_OFFSETS
3702 This is set by architectures that use offsets for link symbols
3703 instead of absolute values. So bss_start is obtained using an
3704 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3705 directly. You should not need to touch this setting.
3707 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3708 This is set by OMAP boards for the max time that reset should
3709 be asserted. See doc/README.omap-reset-time for details on how
3710 the value can be calulated on a given board.
3712 The following definitions that deal with the placement and management
3713 of environment data (variable area); in general, we support the
3714 following configurations:
3716 - CONFIG_BUILD_ENVCRC:
3718 Builds up envcrc with the target environment so that external utils
3719 may easily extract it and embed it in final U-Boot images.
3721 - CONFIG_ENV_IS_IN_FLASH:
3723 Define this if the environment is in flash memory.
3725 a) The environment occupies one whole flash sector, which is
3726 "embedded" in the text segment with the U-Boot code. This
3727 happens usually with "bottom boot sector" or "top boot
3728 sector" type flash chips, which have several smaller
3729 sectors at the start or the end. For instance, such a
3730 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3731 such a case you would place the environment in one of the
3732 4 kB sectors - with U-Boot code before and after it. With
3733 "top boot sector" type flash chips, you would put the
3734 environment in one of the last sectors, leaving a gap
3735 between U-Boot and the environment.
3737 - CONFIG_ENV_OFFSET:
3739 Offset of environment data (variable area) to the
3740 beginning of flash memory; for instance, with bottom boot
3741 type flash chips the second sector can be used: the offset
3742 for this sector is given here.
3744 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3748 This is just another way to specify the start address of
3749 the flash sector containing the environment (instead of
3752 - CONFIG_ENV_SECT_SIZE:
3754 Size of the sector containing the environment.
3757 b) Sometimes flash chips have few, equal sized, BIG sectors.
3758 In such a case you don't want to spend a whole sector for
3763 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3764 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3765 of this flash sector for the environment. This saves
3766 memory for the RAM copy of the environment.
3768 It may also save flash memory if you decide to use this
3769 when your environment is "embedded" within U-Boot code,
3770 since then the remainder of the flash sector could be used
3771 for U-Boot code. It should be pointed out that this is
3772 STRONGLY DISCOURAGED from a robustness point of view:
3773 updating the environment in flash makes it always
3774 necessary to erase the WHOLE sector. If something goes
3775 wrong before the contents has been restored from a copy in
3776 RAM, your target system will be dead.
3778 - CONFIG_ENV_ADDR_REDUND
3779 CONFIG_ENV_SIZE_REDUND
3781 These settings describe a second storage area used to hold
3782 a redundant copy of the environment data, so that there is
3783 a valid backup copy in case there is a power failure during
3784 a "saveenv" operation.
3786 BE CAREFUL! Any changes to the flash layout, and some changes to the
3787 source code will make it necessary to adapt <board>/u-boot.lds*
3791 - CONFIG_ENV_IS_IN_NVRAM:
3793 Define this if you have some non-volatile memory device
3794 (NVRAM, battery buffered SRAM) which you want to use for the
3800 These two #defines are used to determine the memory area you
3801 want to use for environment. It is assumed that this memory
3802 can just be read and written to, without any special
3805 BE CAREFUL! The first access to the environment happens quite early
3806 in U-Boot initalization (when we try to get the setting of for the
3807 console baudrate). You *MUST* have mapped your NVRAM area then, or
3810 Please note that even with NVRAM we still use a copy of the
3811 environment in RAM: we could work on NVRAM directly, but we want to
3812 keep settings there always unmodified except somebody uses "saveenv"
3813 to save the current settings.
3816 - CONFIG_ENV_IS_IN_EEPROM:
3818 Use this if you have an EEPROM or similar serial access
3819 device and a driver for it.
3821 - CONFIG_ENV_OFFSET:
3824 These two #defines specify the offset and size of the
3825 environment area within the total memory of your EEPROM.
3827 - CONFIG_SYS_I2C_EEPROM_ADDR:
3828 If defined, specified the chip address of the EEPROM device.
3829 The default address is zero.
3831 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3832 If defined, the number of bits used to address bytes in a
3833 single page in the EEPROM device. A 64 byte page, for example
3834 would require six bits.
3836 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3837 If defined, the number of milliseconds to delay between
3838 page writes. The default is zero milliseconds.
3840 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3841 The length in bytes of the EEPROM memory array address. Note
3842 that this is NOT the chip address length!
3844 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3845 EEPROM chips that implement "address overflow" are ones
3846 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3847 address and the extra bits end up in the "chip address" bit
3848 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3851 Note that we consider the length of the address field to
3852 still be one byte because the extra address bits are hidden
3853 in the chip address.
3855 - CONFIG_SYS_EEPROM_SIZE:
3856 The size in bytes of the EEPROM device.
3858 - CONFIG_ENV_EEPROM_IS_ON_I2C
3859 define this, if you have I2C and SPI activated, and your
3860 EEPROM, which holds the environment, is on the I2C bus.
3862 - CONFIG_I2C_ENV_EEPROM_BUS
3863 if you have an Environment on an EEPROM reached over
3864 I2C muxes, you can define here, how to reach this
3865 EEPROM. For example:
3867 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3869 EEPROM which holds the environment, is reached over
3870 a pca9547 i2c mux with address 0x70, channel 3.
3872 - CONFIG_ENV_IS_IN_DATAFLASH:
3874 Define this if you have a DataFlash memory device which you
3875 want to use for the environment.
3877 - CONFIG_ENV_OFFSET:
3881 These three #defines specify the offset and size of the
3882 environment area within the total memory of your DataFlash placed
3883 at the specified address.
3885 - CONFIG_ENV_IS_IN_REMOTE:
3887 Define this if you have a remote memory space which you
3888 want to use for the local device's environment.
3893 These two #defines specify the address and size of the
3894 environment area within the remote memory space. The
3895 local device can get the environment from remote memory
3896 space by SRIO or PCIE links.
3898 BE CAREFUL! For some special cases, the local device can not use
3899 "saveenv" command. For example, the local device will get the
3900 environment stored in a remote NOR flash by SRIO or PCIE link,
3901 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3903 - CONFIG_ENV_IS_IN_NAND:
3905 Define this if you have a NAND device which you want to use
3906 for the environment.
3908 - CONFIG_ENV_OFFSET:
3911 These two #defines specify the offset and size of the environment
3912 area within the first NAND device. CONFIG_ENV_OFFSET must be
3913 aligned to an erase block boundary.
3915 - CONFIG_ENV_OFFSET_REDUND (optional):
3917 This setting describes a second storage area of CONFIG_ENV_SIZE
3918 size used to hold a redundant copy of the environment data, so
3919 that there is a valid backup copy in case there is a power failure
3920 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3921 aligned to an erase block boundary.
3923 - CONFIG_ENV_RANGE (optional):
3925 Specifies the length of the region in which the environment
3926 can be written. This should be a multiple of the NAND device's
3927 block size. Specifying a range with more erase blocks than
3928 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3929 the range to be avoided.
3931 - CONFIG_ENV_OFFSET_OOB (optional):
3933 Enables support for dynamically retrieving the offset of the
3934 environment from block zero's out-of-band data. The
3935 "nand env.oob" command can be used to record this offset.
3936 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3937 using CONFIG_ENV_OFFSET_OOB.
3939 - CONFIG_NAND_ENV_DST
3941 Defines address in RAM to which the nand_spl code should copy the
3942 environment. If redundant environment is used, it will be copied to
3943 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3945 - CONFIG_ENV_IS_IN_UBI:
3947 Define this if you have an UBI volume that you want to use for the
3948 environment. This has the benefit of wear-leveling the environment
3949 accesses, which is important on NAND.
3951 - CONFIG_ENV_UBI_PART:
3953 Define this to a string that is the mtd partition containing the UBI.
3955 - CONFIG_ENV_UBI_VOLUME:
3957 Define this to the name of the volume that you want to store the
3960 - CONFIG_ENV_UBI_VOLUME_REDUND:
3962 Define this to the name of another volume to store a second copy of
3963 the environment in. This will enable redundant environments in UBI.
3964 It is assumed that both volumes are in the same MTD partition.
3966 - CONFIG_UBI_SILENCE_MSG
3967 - CONFIG_UBIFS_SILENCE_MSG
3969 You will probably want to define these to avoid a really noisy system
3970 when storing the env in UBI.
3972 - CONFIG_ENV_IS_IN_MMC:
3974 Define this if you have an MMC device which you want to use for the
3977 - CONFIG_SYS_MMC_ENV_DEV:
3979 Specifies which MMC device the environment is stored in.
3981 - CONFIG_SYS_MMC_ENV_PART (optional):
3983 Specifies which MMC partition the environment is stored in. If not
3984 set, defaults to partition 0, the user area. Common values might be
3985 1 (first MMC boot partition), 2 (second MMC boot partition).
3987 - CONFIG_ENV_OFFSET:
3990 These two #defines specify the offset and size of the environment
3991 area within the specified MMC device.
3993 If offset is positive (the usual case), it is treated as relative to
3994 the start of the MMC partition. If offset is negative, it is treated
3995 as relative to the end of the MMC partition. This can be useful if
3996 your board may be fitted with different MMC devices, which have
3997 different sizes for the MMC partitions, and you always want the
3998 environment placed at the very end of the partition, to leave the
3999 maximum possible space before it, to store other data.
4001 These two values are in units of bytes, but must be aligned to an
4002 MMC sector boundary.
4004 - CONFIG_ENV_OFFSET_REDUND (optional):
4006 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4007 hold a redundant copy of the environment data. This provides a
4008 valid backup copy in case the other copy is corrupted, e.g. due
4009 to a power failure during a "saveenv" operation.
4011 This value may also be positive or negative; this is handled in the
4012 same way as CONFIG_ENV_OFFSET.
4014 This value is also in units of bytes, but must also be aligned to
4015 an MMC sector boundary.
4017 - CONFIG_ENV_SIZE_REDUND (optional):
4019 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4020 set. If this value is set, it must be set to the same value as
4023 - CONFIG_SYS_SPI_INIT_OFFSET
4025 Defines offset to the initial SPI buffer area in DPRAM. The
4026 area is used at an early stage (ROM part) if the environment
4027 is configured to reside in the SPI EEPROM: We need a 520 byte
4028 scratch DPRAM area. It is used between the two initialization
4029 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4030 to be a good choice since it makes it far enough from the
4031 start of the data area as well as from the stack pointer.
4033 Please note that the environment is read-only until the monitor
4034 has been relocated to RAM and a RAM copy of the environment has been
4035 created; also, when using EEPROM you will have to use getenv_f()
4036 until then to read environment variables.
4038 The environment is protected by a CRC32 checksum. Before the monitor
4039 is relocated into RAM, as a result of a bad CRC you will be working
4040 with the compiled-in default environment - *silently*!!! [This is
4041 necessary, because the first environment variable we need is the
4042 "baudrate" setting for the console - if we have a bad CRC, we don't
4043 have any device yet where we could complain.]
4045 Note: once the monitor has been relocated, then it will complain if
4046 the default environment is used; a new CRC is computed as soon as you
4047 use the "saveenv" command to store a valid environment.
4049 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4050 Echo the inverted Ethernet link state to the fault LED.
4052 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4053 also needs to be defined.
4055 - CONFIG_SYS_FAULT_MII_ADDR:
4056 MII address of the PHY to check for the Ethernet link state.
4058 - CONFIG_NS16550_MIN_FUNCTIONS:
4059 Define this if you desire to only have use of the NS16550_init
4060 and NS16550_putc functions for the serial driver located at
4061 drivers/serial/ns16550.c. This option is useful for saving
4062 space for already greatly restricted images, including but not
4063 limited to NAND_SPL configurations.
4065 - CONFIG_DISPLAY_BOARDINFO
4066 Display information about the board that U-Boot is running on
4067 when U-Boot starts up. The board function checkboard() is called
4070 - CONFIG_DISPLAY_BOARDINFO_LATE
4071 Similar to the previous option, but display this information
4072 later, once stdio is running and output goes to the LCD, if
4075 Low Level (hardware related) configuration options:
4076 ---------------------------------------------------
4078 - CONFIG_SYS_CACHELINE_SIZE:
4079 Cache Line Size of the CPU.
4081 - CONFIG_SYS_DEFAULT_IMMR:
4082 Default address of the IMMR after system reset.
4084 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4085 and RPXsuper) to be able to adjust the position of
4086 the IMMR register after a reset.
4088 - CONFIG_SYS_CCSRBAR_DEFAULT:
4089 Default (power-on reset) physical address of CCSR on Freescale
4092 - CONFIG_SYS_CCSRBAR:
4093 Virtual address of CCSR. On a 32-bit build, this is typically
4094 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4096 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4097 for cross-platform code that uses that macro instead.
4099 - CONFIG_SYS_CCSRBAR_PHYS:
4100 Physical address of CCSR. CCSR can be relocated to a new
4101 physical address, if desired. In this case, this macro should
4102 be set to that address. Otherwise, it should be set to the
4103 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4104 is typically relocated on 36-bit builds. It is recommended
4105 that this macro be defined via the _HIGH and _LOW macros:
4107 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4108 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4110 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4111 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4112 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4113 used in assembly code, so it must not contain typecasts or
4114 integer size suffixes (e.g. "ULL").
4116 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4117 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4118 used in assembly code, so it must not contain typecasts or
4119 integer size suffixes (e.g. "ULL").
4121 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4122 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4123 forced to a value that ensures that CCSR is not relocated.
4125 - Floppy Disk Support:
4126 CONFIG_SYS_FDC_DRIVE_NUMBER
4128 the default drive number (default value 0)
4130 CONFIG_SYS_ISA_IO_STRIDE
4132 defines the spacing between FDC chipset registers
4135 CONFIG_SYS_ISA_IO_OFFSET
4137 defines the offset of register from address. It
4138 depends on which part of the data bus is connected to
4139 the FDC chipset. (default value 0)
4141 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4142 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4145 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4146 fdc_hw_init() is called at the beginning of the FDC
4147 setup. fdc_hw_init() must be provided by the board
4148 source code. It is used to make hardware dependant
4152 Most IDE controllers were designed to be connected with PCI
4153 interface. Only few of them were designed for AHB interface.
4154 When software is doing ATA command and data transfer to
4155 IDE devices through IDE-AHB controller, some additional
4156 registers accessing to these kind of IDE-AHB controller
4159 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4160 DO NOT CHANGE unless you know exactly what you're
4161 doing! (11-4) [MPC8xx/82xx systems only]
4163 - CONFIG_SYS_INIT_RAM_ADDR:
4165 Start address of memory area that can be used for
4166 initial data and stack; please note that this must be
4167 writable memory that is working WITHOUT special
4168 initialization, i. e. you CANNOT use normal RAM which
4169 will become available only after programming the
4170 memory controller and running certain initialization
4173 U-Boot uses the following memory types:
4174 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4175 - MPC824X: data cache
4176 - PPC4xx: data cache
4178 - CONFIG_SYS_GBL_DATA_OFFSET:
4180 Offset of the initial data structure in the memory
4181 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4182 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4183 data is located at the end of the available space
4184 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4185 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4186 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4187 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4190 On the MPC824X (or other systems that use the data
4191 cache for initial memory) the address chosen for
4192 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4193 point to an otherwise UNUSED address space between
4194 the top of RAM and the start of the PCI space.
4196 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4198 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4200 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4202 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4204 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4206 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4208 - CONFIG_SYS_OR_TIMING_SDRAM:
4211 - CONFIG_SYS_MAMR_PTA:
4212 periodic timer for refresh
4214 - CONFIG_SYS_DER: Debug Event Register (37-47)
4216 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4217 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4218 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4219 CONFIG_SYS_BR1_PRELIM:
4220 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4222 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4223 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4224 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4225 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4227 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4228 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4229 Machine Mode Register and Memory Periodic Timer
4230 Prescaler definitions (SDRAM timing)
4232 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4233 enable I2C microcode relocation patch (MPC8xx);
4234 define relocation offset in DPRAM [DSP2]
4236 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4237 enable SMC microcode relocation patch (MPC8xx);
4238 define relocation offset in DPRAM [SMC1]
4240 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4241 enable SPI microcode relocation patch (MPC8xx);
4242 define relocation offset in DPRAM [SCC4]
4244 - CONFIG_SYS_USE_OSCCLK:
4245 Use OSCM clock mode on MBX8xx board. Be careful,
4246 wrong setting might damage your board. Read
4247 doc/README.MBX before setting this variable!
4249 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4250 Offset of the bootmode word in DPRAM used by post
4251 (Power On Self Tests). This definition overrides
4252 #define'd default value in commproc.h resp.
4255 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4256 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4257 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4258 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4259 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4260 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4261 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4262 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4263 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4265 - CONFIG_PCI_DISABLE_PCIE:
4266 Disable PCI-Express on systems where it is supported but not
4269 - CONFIG_PCI_ENUM_ONLY
4270 Only scan through and get the devices on the busses.
4271 Don't do any setup work, presumably because someone or
4272 something has already done it, and we don't need to do it
4273 a second time. Useful for platforms that are pre-booted
4274 by coreboot or similar.
4276 - CONFIG_PCI_INDIRECT_BRIDGE:
4277 Enable support for indirect PCI bridges.
4280 Chip has SRIO or not
4283 Board has SRIO 1 port available
4286 Board has SRIO 2 port available
4288 - CONFIG_SRIO_PCIE_BOOT_MASTER
4289 Board can support master function for Boot from SRIO and PCIE
4291 - CONFIG_SYS_SRIOn_MEM_VIRT:
4292 Virtual Address of SRIO port 'n' memory region
4294 - CONFIG_SYS_SRIOn_MEM_PHYS:
4295 Physical Address of SRIO port 'n' memory region
4297 - CONFIG_SYS_SRIOn_MEM_SIZE:
4298 Size of SRIO port 'n' memory region
4300 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4301 Defined to tell the NAND controller that the NAND chip is using
4303 Not all NAND drivers use this symbol.
4304 Example of drivers that use it:
4305 - drivers/mtd/nand/ndfc.c
4306 - drivers/mtd/nand/mxc_nand.c
4308 - CONFIG_SYS_NDFC_EBC0_CFG
4309 Sets the EBC0_CFG register for the NDFC. If not defined
4310 a default value will be used.
4313 Get DDR timing information from an I2C EEPROM. Common
4314 with pluggable memory modules such as SODIMMs
4317 I2C address of the SPD EEPROM
4319 - CONFIG_SYS_SPD_BUS_NUM
4320 If SPD EEPROM is on an I2C bus other than the first
4321 one, specify here. Note that the value must resolve
4322 to something your driver can deal with.
4324 - CONFIG_SYS_DDR_RAW_TIMING
4325 Get DDR timing information from other than SPD. Common with
4326 soldered DDR chips onboard without SPD. DDR raw timing
4327 parameters are extracted from datasheet and hard-coded into
4328 header files or board specific files.
4330 - CONFIG_FSL_DDR_INTERACTIVE
4331 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4333 - CONFIG_SYS_83XX_DDR_USES_CS0
4334 Only for 83xx systems. If specified, then DDR should
4335 be configured using CS0 and CS1 instead of CS2 and CS3.
4337 - CONFIG_ETHER_ON_FEC[12]
4338 Define to enable FEC[12] on a 8xx series processor.
4340 - CONFIG_FEC[12]_PHY
4341 Define to the hardcoded PHY address which corresponds
4342 to the given FEC; i. e.
4343 #define CONFIG_FEC1_PHY 4
4344 means that the PHY with address 4 is connected to FEC1
4346 When set to -1, means to probe for first available.
4348 - CONFIG_FEC[12]_PHY_NORXERR
4349 The PHY does not have a RXERR line (RMII only).
4350 (so program the FEC to ignore it).
4353 Enable RMII mode for all FECs.
4354 Note that this is a global option, we can't
4355 have one FEC in standard MII mode and another in RMII mode.
4357 - CONFIG_CRC32_VERIFY
4358 Add a verify option to the crc32 command.
4361 => crc32 -v <address> <count> <crc32>
4363 Where address/count indicate a memory area
4364 and crc32 is the correct crc32 which the
4368 Add the "loopw" memory command. This only takes effect if
4369 the memory commands are activated globally (CONFIG_CMD_MEM).
4372 Add the "mdc" and "mwc" memory commands. These are cyclic
4377 This command will print 4 bytes (10,11,12,13) each 500 ms.
4379 => mwc.l 100 12345678 10
4380 This command will write 12345678 to address 100 all 10 ms.
4382 This only takes effect if the memory commands are activated
4383 globally (CONFIG_CMD_MEM).
4385 - CONFIG_SKIP_LOWLEVEL_INIT
4386 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4387 low level initializations (like setting up the memory
4388 controller) are omitted and/or U-Boot does not
4389 relocate itself into RAM.
4391 Normally this variable MUST NOT be defined. The only
4392 exception is when U-Boot is loaded (to RAM) by some
4393 other boot loader or by a debugger which performs
4394 these initializations itself.
4397 Modifies the behaviour of start.S when compiling a loader
4398 that is executed before the actual U-Boot. E.g. when
4399 compiling a NAND SPL.
4402 Modifies the behaviour of start.S when compiling a loader
4403 that is executed after the SPL and before the actual U-Boot.
4404 It is loaded by the SPL.
4406 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4407 Only for 85xx systems. If this variable is specified, the section
4408 .resetvec is not kept and the section .bootpg is placed in the
4409 previous 4k of the .text section.
4411 - CONFIG_ARCH_MAP_SYSMEM
4412 Generally U-Boot (and in particular the md command) uses
4413 effective address. It is therefore not necessary to regard
4414 U-Boot address as virtual addresses that need to be translated
4415 to physical addresses. However, sandbox requires this, since
4416 it maintains its own little RAM buffer which contains all
4417 addressable memory. This option causes some memory accesses
4418 to be mapped through map_sysmem() / unmap_sysmem().
4420 - CONFIG_USE_ARCH_MEMCPY
4421 CONFIG_USE_ARCH_MEMSET
4422 If these options are used a optimized version of memcpy/memset will
4423 be used if available. These functions may be faster under some
4424 conditions but may increase the binary size.
4426 - CONFIG_X86_RESET_VECTOR
4427 If defined, the x86 reset vector code is included. This is not
4428 needed when U-Boot is running from Coreboot.
4431 Defines the MPU clock speed (in MHz).
4433 NOTE : currently only supported on AM335x platforms.
4435 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4436 Enables the RTC32K OSC on AM33xx based plattforms
4438 Freescale QE/FMAN Firmware Support:
4439 -----------------------------------
4441 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4442 loading of "firmware", which is encoded in the QE firmware binary format.
4443 This firmware often needs to be loaded during U-Boot booting, so macros
4444 are used to identify the storage device (NOR flash, SPI, etc) and the address
4447 - CONFIG_SYS_QE_FMAN_FW_ADDR
4448 The address in the storage device where the firmware is located. The
4449 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4452 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4453 The maximum possible size of the firmware. The firmware binary format
4454 has a field that specifies the actual size of the firmware, but it
4455 might not be possible to read any part of the firmware unless some
4456 local storage is allocated to hold the entire firmware first.
4458 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4459 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4460 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4461 virtual address in NOR flash.
4463 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4464 Specifies that QE/FMAN firmware is located in NAND flash.
4465 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4467 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4468 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4469 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4471 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4472 Specifies that QE/FMAN firmware is located on the primary SPI
4473 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4475 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4476 Specifies that QE/FMAN firmware is located in the remote (master)
4477 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4478 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4479 window->master inbound window->master LAW->the ucode address in
4480 master's memory space.
4482 Building the Software:
4483 ======================
4485 Building U-Boot has been tested in several native build environments
4486 and in many different cross environments. Of course we cannot support
4487 all possibly existing versions of cross development tools in all
4488 (potentially obsolete) versions. In case of tool chain problems we
4489 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4490 which is extensively used to build and test U-Boot.
4492 If you are not using a native environment, it is assumed that you
4493 have GNU cross compiling tools available in your path. In this case,
4494 you must set the environment variable CROSS_COMPILE in your shell.
4495 Note that no changes to the Makefile or any other source files are
4496 necessary. For example using the ELDK on a 4xx CPU, please enter:
4498 $ CROSS_COMPILE=ppc_4xx-
4499 $ export CROSS_COMPILE
4501 Note: If you wish to generate Windows versions of the utilities in
4502 the tools directory you can use the MinGW toolchain
4503 (http://www.mingw.org). Set your HOST tools to the MinGW
4504 toolchain and execute 'make tools'. For example:
4506 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4508 Binaries such as tools/mkimage.exe will be created which can
4509 be executed on computers running Windows.
4511 U-Boot is intended to be simple to build. After installing the
4512 sources you must configure U-Boot for one specific board type. This
4517 where "NAME_config" is the name of one of the existing configu-
4518 rations; see boards.cfg for supported names.
4520 Note: for some board special configuration names may exist; check if
4521 additional information is available from the board vendor; for
4522 instance, the TQM823L systems are available without (standard)
4523 or with LCD support. You can select such additional "features"
4524 when choosing the configuration, i. e.
4527 - will configure for a plain TQM823L, i. e. no LCD support
4529 make TQM823L_LCD_config
4530 - will configure for a TQM823L with U-Boot console on LCD
4535 Finally, type "make all", and you should get some working U-Boot
4536 images ready for download to / installation on your system:
4538 - "u-boot.bin" is a raw binary image
4539 - "u-boot" is an image in ELF binary format
4540 - "u-boot.srec" is in Motorola S-Record format
4542 By default the build is performed locally and the objects are saved
4543 in the source directory. One of the two methods can be used to change
4544 this behavior and build U-Boot to some external directory:
4546 1. Add O= to the make command line invocations:
4548 make O=/tmp/build distclean
4549 make O=/tmp/build NAME_config
4550 make O=/tmp/build all
4552 2. Set environment variable BUILD_DIR to point to the desired location:
4554 export BUILD_DIR=/tmp/build
4559 Note that the command line "O=" setting overrides the BUILD_DIR environment
4563 Please be aware that the Makefiles assume you are using GNU make, so
4564 for instance on NetBSD you might need to use "gmake" instead of
4568 If the system board that you have is not listed, then you will need
4569 to port U-Boot to your hardware platform. To do this, follow these
4572 1. Add a new configuration option for your board to the toplevel
4573 "boards.cfg" file, using the existing entries as examples.
4574 Follow the instructions there to keep the boards in order.
4575 2. Create a new directory to hold your board specific code. Add any
4576 files you need. In your board directory, you will need at least
4577 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4578 3. Create a new configuration file "include/configs/<board>.h" for
4580 3. If you're porting U-Boot to a new CPU, then also create a new
4581 directory to hold your CPU specific code. Add any files you need.
4582 4. Run "make <board>_config" with your new name.
4583 5. Type "make", and you should get a working "u-boot.srec" file
4584 to be installed on your target system.
4585 6. Debug and solve any problems that might arise.
4586 [Of course, this last step is much harder than it sounds.]
4589 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4590 ==============================================================
4592 If you have modified U-Boot sources (for instance added a new board
4593 or support for new devices, a new CPU, etc.) you are expected to
4594 provide feedback to the other developers. The feedback normally takes
4595 the form of a "patch", i. e. a context diff against a certain (latest
4596 official or latest in the git repository) version of U-Boot sources.
4598 But before you submit such a patch, please verify that your modifi-
4599 cation did not break existing code. At least make sure that *ALL* of
4600 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4601 just run the "MAKEALL" script, which will configure and build U-Boot
4602 for ALL supported system. Be warned, this will take a while. You can
4603 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4604 environment variable to the script, i. e. to use the ELDK cross tools
4607 CROSS_COMPILE=ppc_8xx- MAKEALL
4609 or to build on a native PowerPC system you can type
4611 CROSS_COMPILE=' ' MAKEALL
4613 When using the MAKEALL script, the default behaviour is to build
4614 U-Boot in the source directory. This location can be changed by
4615 setting the BUILD_DIR environment variable. Also, for each target
4616 built, the MAKEALL script saves two log files (<target>.ERR and
4617 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4618 location can be changed by setting the MAKEALL_LOGDIR environment
4619 variable. For example:
4621 export BUILD_DIR=/tmp/build
4622 export MAKEALL_LOGDIR=/tmp/log
4623 CROSS_COMPILE=ppc_8xx- MAKEALL
4625 With the above settings build objects are saved in the /tmp/build,
4626 log files are saved in the /tmp/log and the source tree remains clean
4627 during the whole build process.
4630 See also "U-Boot Porting Guide" below.
4633 Monitor Commands - Overview:
4634 ============================
4636 go - start application at address 'addr'
4637 run - run commands in an environment variable
4638 bootm - boot application image from memory
4639 bootp - boot image via network using BootP/TFTP protocol
4640 bootz - boot zImage from memory
4641 tftpboot- boot image via network using TFTP protocol
4642 and env variables "ipaddr" and "serverip"
4643 (and eventually "gatewayip")
4644 tftpput - upload a file via network using TFTP protocol
4645 rarpboot- boot image via network using RARP/TFTP protocol
4646 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4647 loads - load S-Record file over serial line
4648 loadb - load binary file over serial line (kermit mode)
4650 mm - memory modify (auto-incrementing)
4651 nm - memory modify (constant address)
4652 mw - memory write (fill)
4654 cmp - memory compare
4655 crc32 - checksum calculation
4656 i2c - I2C sub-system
4657 sspi - SPI utility commands
4658 base - print or set address offset
4659 printenv- print environment variables
4660 setenv - set environment variables
4661 saveenv - save environment variables to persistent storage
4662 protect - enable or disable FLASH write protection
4663 erase - erase FLASH memory
4664 flinfo - print FLASH memory information
4665 nand - NAND memory operations (see doc/README.nand)
4666 bdinfo - print Board Info structure
4667 iminfo - print header information for application image
4668 coninfo - print console devices and informations
4669 ide - IDE sub-system
4670 loop - infinite loop on address range
4671 loopw - infinite write loop on address range
4672 mtest - simple RAM test
4673 icache - enable or disable instruction cache
4674 dcache - enable or disable data cache
4675 reset - Perform RESET of the CPU
4676 echo - echo args to console
4677 version - print monitor version
4678 help - print online help
4679 ? - alias for 'help'
4682 Monitor Commands - Detailed Description:
4683 ========================================
4687 For now: just type "help <command>".
4690 Environment Variables:
4691 ======================
4693 U-Boot supports user configuration using Environment Variables which
4694 can be made persistent by saving to Flash memory.
4696 Environment Variables are set using "setenv", printed using
4697 "printenv", and saved to Flash using "saveenv". Using "setenv"
4698 without a value can be used to delete a variable from the
4699 environment. As long as you don't save the environment you are
4700 working with an in-memory copy. In case the Flash area containing the
4701 environment is erased by accident, a default environment is provided.
4703 Some configuration options can be set using Environment Variables.
4705 List of environment variables (most likely not complete):
4707 baudrate - see CONFIG_BAUDRATE
4709 bootdelay - see CONFIG_BOOTDELAY
4711 bootcmd - see CONFIG_BOOTCOMMAND
4713 bootargs - Boot arguments when booting an RTOS image
4715 bootfile - Name of the image to load with TFTP
4717 bootm_low - Memory range available for image processing in the bootm
4718 command can be restricted. This variable is given as
4719 a hexadecimal number and defines lowest address allowed
4720 for use by the bootm command. See also "bootm_size"
4721 environment variable. Address defined by "bootm_low" is
4722 also the base of the initial memory mapping for the Linux
4723 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4726 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4727 This variable is given as a hexadecimal number and it
4728 defines the size of the memory region starting at base
4729 address bootm_low that is accessible by the Linux kernel
4730 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4731 as the default value if it is defined, and bootm_size is
4734 bootm_size - Memory range available for image processing in the bootm
4735 command can be restricted. This variable is given as
4736 a hexadecimal number and defines the size of the region
4737 allowed for use by the bootm command. See also "bootm_low"
4738 environment variable.
4740 updatefile - Location of the software update file on a TFTP server, used
4741 by the automatic software update feature. Please refer to
4742 documentation in doc/README.update for more details.
4744 autoload - if set to "no" (any string beginning with 'n'),
4745 "bootp" will just load perform a lookup of the
4746 configuration from the BOOTP server, but not try to
4747 load any image using TFTP
4749 autostart - if set to "yes", an image loaded using the "bootp",
4750 "rarpboot", "tftpboot" or "diskboot" commands will
4751 be automatically started (by internally calling
4754 If set to "no", a standalone image passed to the
4755 "bootm" command will be copied to the load address
4756 (and eventually uncompressed), but NOT be started.
4757 This can be used to load and uncompress arbitrary
4760 fdt_high - if set this restricts the maximum address that the
4761 flattened device tree will be copied into upon boot.
4762 For example, if you have a system with 1 GB memory
4763 at physical address 0x10000000, while Linux kernel
4764 only recognizes the first 704 MB as low memory, you
4765 may need to set fdt_high as 0x3C000000 to have the
4766 device tree blob be copied to the maximum address
4767 of the 704 MB low memory, so that Linux kernel can
4768 access it during the boot procedure.
4770 If this is set to the special value 0xFFFFFFFF then
4771 the fdt will not be copied at all on boot. For this
4772 to work it must reside in writable memory, have
4773 sufficient padding on the end of it for u-boot to
4774 add the information it needs into it, and the memory
4775 must be accessible by the kernel.
4777 fdtcontroladdr- if set this is the address of the control flattened
4778 device tree used by U-Boot when CONFIG_OF_CONTROL is
4781 i2cfast - (PPC405GP|PPC405EP only)
4782 if set to 'y' configures Linux I2C driver for fast
4783 mode (400kHZ). This environment variable is used in
4784 initialization code. So, for changes to be effective
4785 it must be saved and board must be reset.
4787 initrd_high - restrict positioning of initrd images:
4788 If this variable is not set, initrd images will be
4789 copied to the highest possible address in RAM; this
4790 is usually what you want since it allows for
4791 maximum initrd size. If for some reason you want to
4792 make sure that the initrd image is loaded below the
4793 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4794 variable to a value of "no" or "off" or "0".
4795 Alternatively, you can set it to a maximum upper
4796 address to use (U-Boot will still check that it
4797 does not overwrite the U-Boot stack and data).
4799 For instance, when you have a system with 16 MB
4800 RAM, and want to reserve 4 MB from use by Linux,
4801 you can do this by adding "mem=12M" to the value of
4802 the "bootargs" variable. However, now you must make
4803 sure that the initrd image is placed in the first
4804 12 MB as well - this can be done with
4806 setenv initrd_high 00c00000
4808 If you set initrd_high to 0xFFFFFFFF, this is an
4809 indication to U-Boot that all addresses are legal
4810 for the Linux kernel, including addresses in flash
4811 memory. In this case U-Boot will NOT COPY the
4812 ramdisk at all. This may be useful to reduce the
4813 boot time on your system, but requires that this
4814 feature is supported by your Linux kernel.
4816 ipaddr - IP address; needed for tftpboot command
4818 loadaddr - Default load address for commands like "bootp",
4819 "rarpboot", "tftpboot", "loadb" or "diskboot"
4821 loads_echo - see CONFIG_LOADS_ECHO
4823 serverip - TFTP server IP address; needed for tftpboot command
4825 bootretry - see CONFIG_BOOT_RETRY_TIME
4827 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4829 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4831 ethprime - controls which interface is used first.
4833 ethact - controls which interface is currently active.
4834 For example you can do the following
4836 => setenv ethact FEC
4837 => ping 192.168.0.1 # traffic sent on FEC
4838 => setenv ethact SCC
4839 => ping 10.0.0.1 # traffic sent on SCC
4841 ethrotate - When set to "no" U-Boot does not go through all
4842 available network interfaces.
4843 It just stays at the currently selected interface.
4845 netretry - When set to "no" each network operation will
4846 either succeed or fail without retrying.
4847 When set to "once" the network operation will
4848 fail when all the available network interfaces
4849 are tried once without success.
4850 Useful on scripts which control the retry operation
4853 npe_ucode - set load address for the NPE microcode
4855 silent_linux - If set then linux will be told to boot silently, by
4856 changing the console to be empty. If "yes" it will be
4857 made silent. If "no" it will not be made silent. If
4858 unset, then it will be made silent if the U-Boot console
4861 tftpsrcport - If this is set, the value is used for TFTP's
4864 tftpdstport - If this is set, the value is used for TFTP's UDP
4865 destination port instead of the Well Know Port 69.
4867 tftpblocksize - Block size to use for TFTP transfers; if not set,
4868 we use the TFTP server's default block size
4870 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4871 seconds, minimum value is 1000 = 1 second). Defines
4872 when a packet is considered to be lost so it has to
4873 be retransmitted. The default is 5000 = 5 seconds.
4874 Lowering this value may make downloads succeed
4875 faster in networks with high packet loss rates or
4876 with unreliable TFTP servers.
4878 vlan - When set to a value < 4095 the traffic over
4879 Ethernet is encapsulated/received over 802.1q
4882 The following image location variables contain the location of images
4883 used in booting. The "Image" column gives the role of the image and is
4884 not an environment variable name. The other columns are environment
4885 variable names. "File Name" gives the name of the file on a TFTP
4886 server, "RAM Address" gives the location in RAM the image will be
4887 loaded to, and "Flash Location" gives the image's address in NOR
4888 flash or offset in NAND flash.
4890 *Note* - these variables don't have to be defined for all boards, some
4891 boards currenlty use other variables for these purposes, and some
4892 boards use these variables for other purposes.
4894 Image File Name RAM Address Flash Location
4895 ----- --------- ----------- --------------
4896 u-boot u-boot u-boot_addr_r u-boot_addr
4897 Linux kernel bootfile kernel_addr_r kernel_addr
4898 device tree blob fdtfile fdt_addr_r fdt_addr
4899 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4901 The following environment variables may be used and automatically
4902 updated by the network boot commands ("bootp" and "rarpboot"),
4903 depending the information provided by your boot server:
4905 bootfile - see above
4906 dnsip - IP address of your Domain Name Server
4907 dnsip2 - IP address of your secondary Domain Name Server
4908 gatewayip - IP address of the Gateway (Router) to use
4909 hostname - Target hostname
4911 netmask - Subnet Mask
4912 rootpath - Pathname of the root filesystem on the NFS server
4913 serverip - see above
4916 There are two special Environment Variables:
4918 serial# - contains hardware identification information such
4919 as type string and/or serial number
4920 ethaddr - Ethernet address
4922 These variables can be set only once (usually during manufacturing of
4923 the board). U-Boot refuses to delete or overwrite these variables
4924 once they have been set once.
4927 Further special Environment Variables:
4929 ver - Contains the U-Boot version string as printed
4930 with the "version" command. This variable is
4931 readonly (see CONFIG_VERSION_VARIABLE).
4934 Please note that changes to some configuration parameters may take
4935 only effect after the next boot (yes, that's just like Windoze :-).
4938 Callback functions for environment variables:
4939 ---------------------------------------------
4941 For some environment variables, the behavior of u-boot needs to change
4942 when their values are changed. This functionailty allows functions to
4943 be associated with arbitrary variables. On creation, overwrite, or
4944 deletion, the callback will provide the opportunity for some side
4945 effect to happen or for the change to be rejected.
4947 The callbacks are named and associated with a function using the
4948 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4950 These callbacks are associated with variables in one of two ways. The
4951 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4952 in the board configuration to a string that defines a list of
4953 associations. The list must be in the following format:
4955 entry = variable_name[:callback_name]
4958 If the callback name is not specified, then the callback is deleted.
4959 Spaces are also allowed anywhere in the list.
4961 Callbacks can also be associated by defining the ".callbacks" variable
4962 with the same list format above. Any association in ".callbacks" will
4963 override any association in the static list. You can define
4964 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4965 ".callbacks" envirnoment variable in the default or embedded environment.
4968 Command Line Parsing:
4969 =====================
4971 There are two different command line parsers available with U-Boot:
4972 the old "simple" one, and the much more powerful "hush" shell:
4974 Old, simple command line parser:
4975 --------------------------------
4977 - supports environment variables (through setenv / saveenv commands)
4978 - several commands on one line, separated by ';'
4979 - variable substitution using "... ${name} ..." syntax
4980 - special characters ('$', ';') can be escaped by prefixing with '\',
4982 setenv bootcmd bootm \${address}
4983 - You can also escape text by enclosing in single apostrophes, for example:
4984 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4989 - similar to Bourne shell, with control structures like
4990 if...then...else...fi, for...do...done; while...do...done,
4991 until...do...done, ...
4992 - supports environment ("global") variables (through setenv / saveenv
4993 commands) and local shell variables (through standard shell syntax
4994 "name=value"); only environment variables can be used with "run"
5000 (1) If a command line (or an environment variable executed by a "run"
5001 command) contains several commands separated by semicolon, and
5002 one of these commands fails, then the remaining commands will be
5005 (2) If you execute several variables with one call to run (i. e.
5006 calling run with a list of variables as arguments), any failing
5007 command will cause "run" to terminate, i. e. the remaining
5008 variables are not executed.
5010 Note for Redundant Ethernet Interfaces:
5011 =======================================
5013 Some boards come with redundant Ethernet interfaces; U-Boot supports
5014 such configurations and is capable of automatic selection of a
5015 "working" interface when needed. MAC assignment works as follows:
5017 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5018 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5019 "eth1addr" (=>eth1), "eth2addr", ...
5021 If the network interface stores some valid MAC address (for instance
5022 in SROM), this is used as default address if there is NO correspon-
5023 ding setting in the environment; if the corresponding environment
5024 variable is set, this overrides the settings in the card; that means:
5026 o If the SROM has a valid MAC address, and there is no address in the
5027 environment, the SROM's address is used.
5029 o If there is no valid address in the SROM, and a definition in the
5030 environment exists, then the value from the environment variable is
5033 o If both the SROM and the environment contain a MAC address, and
5034 both addresses are the same, this MAC address is used.
5036 o If both the SROM and the environment contain a MAC address, and the
5037 addresses differ, the value from the environment is used and a
5040 o If neither SROM nor the environment contain a MAC address, an error
5043 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5044 will be programmed into hardware as part of the initialization process. This
5045 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5046 The naming convention is as follows:
5047 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5052 U-Boot is capable of booting (and performing other auxiliary operations on)
5053 images in two formats:
5055 New uImage format (FIT)
5056 -----------------------
5058 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5059 to Flattened Device Tree). It allows the use of images with multiple
5060 components (several kernels, ramdisks, etc.), with contents protected by
5061 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5067 Old image format is based on binary files which can be basically anything,
5068 preceded by a special header; see the definitions in include/image.h for
5069 details; basically, the header defines the following image properties:
5071 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5072 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5073 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5074 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5076 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5077 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5078 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5079 * Compression Type (uncompressed, gzip, bzip2)
5085 The header is marked by a special Magic Number, and both the header
5086 and the data portions of the image are secured against corruption by
5093 Although U-Boot should support any OS or standalone application
5094 easily, the main focus has always been on Linux during the design of
5097 U-Boot includes many features that so far have been part of some
5098 special "boot loader" code within the Linux kernel. Also, any
5099 "initrd" images to be used are no longer part of one big Linux image;
5100 instead, kernel and "initrd" are separate images. This implementation
5101 serves several purposes:
5103 - the same features can be used for other OS or standalone
5104 applications (for instance: using compressed images to reduce the
5105 Flash memory footprint)
5107 - it becomes much easier to port new Linux kernel versions because
5108 lots of low-level, hardware dependent stuff are done by U-Boot
5110 - the same Linux kernel image can now be used with different "initrd"
5111 images; of course this also means that different kernel images can
5112 be run with the same "initrd". This makes testing easier (you don't
5113 have to build a new "zImage.initrd" Linux image when you just
5114 change a file in your "initrd"). Also, a field-upgrade of the
5115 software is easier now.
5121 Porting Linux to U-Boot based systems:
5122 ---------------------------------------
5124 U-Boot cannot save you from doing all the necessary modifications to
5125 configure the Linux device drivers for use with your target hardware
5126 (no, we don't intend to provide a full virtual machine interface to
5129 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5131 Just make sure your machine specific header file (for instance
5132 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5133 Information structure as we define in include/asm-<arch>/u-boot.h,
5134 and make sure that your definition of IMAP_ADDR uses the same value
5135 as your U-Boot configuration in CONFIG_SYS_IMMR.
5138 Configuring the Linux kernel:
5139 -----------------------------
5141 No specific requirements for U-Boot. Make sure you have some root
5142 device (initial ramdisk, NFS) for your target system.
5145 Building a Linux Image:
5146 -----------------------
5148 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5149 not used. If you use recent kernel source, a new build target
5150 "uImage" will exist which automatically builds an image usable by
5151 U-Boot. Most older kernels also have support for a "pImage" target,
5152 which was introduced for our predecessor project PPCBoot and uses a
5153 100% compatible format.
5162 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5163 encapsulate a compressed Linux kernel image with header information,
5164 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5166 * build a standard "vmlinux" kernel image (in ELF binary format):
5168 * convert the kernel into a raw binary image:
5170 ${CROSS_COMPILE}-objcopy -O binary \
5171 -R .note -R .comment \
5172 -S vmlinux linux.bin
5174 * compress the binary image:
5178 * package compressed binary image for U-Boot:
5180 mkimage -A ppc -O linux -T kernel -C gzip \
5181 -a 0 -e 0 -n "Linux Kernel Image" \
5182 -d linux.bin.gz uImage
5185 The "mkimage" tool can also be used to create ramdisk images for use
5186 with U-Boot, either separated from the Linux kernel image, or
5187 combined into one file. "mkimage" encapsulates the images with a 64
5188 byte header containing information about target architecture,
5189 operating system, image type, compression method, entry points, time
5190 stamp, CRC32 checksums, etc.
5192 "mkimage" can be called in two ways: to verify existing images and
5193 print the header information, or to build new images.
5195 In the first form (with "-l" option) mkimage lists the information
5196 contained in the header of an existing U-Boot image; this includes
5197 checksum verification:
5199 tools/mkimage -l image
5200 -l ==> list image header information
5202 The second form (with "-d" option) is used to build a U-Boot image
5203 from a "data file" which is used as image payload:
5205 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5206 -n name -d data_file image
5207 -A ==> set architecture to 'arch'
5208 -O ==> set operating system to 'os'
5209 -T ==> set image type to 'type'
5210 -C ==> set compression type 'comp'
5211 -a ==> set load address to 'addr' (hex)
5212 -e ==> set entry point to 'ep' (hex)
5213 -n ==> set image name to 'name'
5214 -d ==> use image data from 'datafile'
5216 Right now, all Linux kernels for PowerPC systems use the same load
5217 address (0x00000000), but the entry point address depends on the
5220 - 2.2.x kernels have the entry point at 0x0000000C,
5221 - 2.3.x and later kernels have the entry point at 0x00000000.
5223 So a typical call to build a U-Boot image would read:
5225 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5226 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5227 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5228 > examples/uImage.TQM850L
5229 Image Name: 2.4.4 kernel for TQM850L
5230 Created: Wed Jul 19 02:34:59 2000
5231 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5232 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5233 Load Address: 0x00000000
5234 Entry Point: 0x00000000
5236 To verify the contents of the image (or check for corruption):
5238 -> tools/mkimage -l examples/uImage.TQM850L
5239 Image Name: 2.4.4 kernel for TQM850L
5240 Created: Wed Jul 19 02:34:59 2000
5241 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5242 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5243 Load Address: 0x00000000
5244 Entry Point: 0x00000000
5246 NOTE: for embedded systems where boot time is critical you can trade
5247 speed for memory and install an UNCOMPRESSED image instead: this
5248 needs more space in Flash, but boots much faster since it does not
5249 need to be uncompressed:
5251 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5252 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5253 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5254 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5255 > examples/uImage.TQM850L-uncompressed
5256 Image Name: 2.4.4 kernel for TQM850L
5257 Created: Wed Jul 19 02:34:59 2000
5258 Image Type: PowerPC Linux Kernel Image (uncompressed)
5259 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5260 Load Address: 0x00000000
5261 Entry Point: 0x00000000
5264 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5265 when your kernel is intended to use an initial ramdisk:
5267 -> tools/mkimage -n 'Simple Ramdisk Image' \
5268 > -A ppc -O linux -T ramdisk -C gzip \
5269 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5270 Image Name: Simple Ramdisk Image
5271 Created: Wed Jan 12 14:01:50 2000
5272 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5273 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5274 Load Address: 0x00000000
5275 Entry Point: 0x00000000
5277 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5278 option performs the converse operation of the mkimage's second form (the "-d"
5279 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5282 tools/dumpimage -i image -p position data_file
5283 -i ==> extract from the 'image' a specific 'data_file', \
5284 indexed by 'position'
5287 Installing a Linux Image:
5288 -------------------------
5290 To downloading a U-Boot image over the serial (console) interface,
5291 you must convert the image to S-Record format:
5293 objcopy -I binary -O srec examples/image examples/image.srec
5295 The 'objcopy' does not understand the information in the U-Boot
5296 image header, so the resulting S-Record file will be relative to
5297 address 0x00000000. To load it to a given address, you need to
5298 specify the target address as 'offset' parameter with the 'loads'
5301 Example: install the image to address 0x40100000 (which on the
5302 TQM8xxL is in the first Flash bank):
5304 => erase 40100000 401FFFFF
5310 ## Ready for S-Record download ...
5311 ~>examples/image.srec
5312 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5314 15989 15990 15991 15992
5315 [file transfer complete]
5317 ## Start Addr = 0x00000000
5320 You can check the success of the download using the 'iminfo' command;
5321 this includes a checksum verification so you can be sure no data
5322 corruption happened:
5326 ## Checking Image at 40100000 ...
5327 Image Name: 2.2.13 for initrd on TQM850L
5328 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5329 Data Size: 335725 Bytes = 327 kB = 0 MB
5330 Load Address: 00000000
5331 Entry Point: 0000000c
5332 Verifying Checksum ... OK
5338 The "bootm" command is used to boot an application that is stored in
5339 memory (RAM or Flash). In case of a Linux kernel image, the contents
5340 of the "bootargs" environment variable is passed to the kernel as
5341 parameters. You can check and modify this variable using the
5342 "printenv" and "setenv" commands:
5345 => printenv bootargs
5346 bootargs=root=/dev/ram
5348 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5350 => printenv bootargs
5351 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5354 ## Booting Linux kernel at 40020000 ...
5355 Image Name: 2.2.13 for NFS on TQM850L
5356 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5357 Data Size: 381681 Bytes = 372 kB = 0 MB
5358 Load Address: 00000000
5359 Entry Point: 0000000c
5360 Verifying Checksum ... OK
5361 Uncompressing Kernel Image ... OK
5362 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
5363 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5364 time_init: decrementer frequency = 187500000/60
5365 Calibrating delay loop... 49.77 BogoMIPS
5366 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5369 If you want to boot a Linux kernel with initial RAM disk, you pass
5370 the memory addresses of both the kernel and the initrd image (PPBCOOT
5371 format!) to the "bootm" command:
5373 => imi 40100000 40200000
5375 ## Checking Image at 40100000 ...
5376 Image Name: 2.2.13 for initrd on TQM850L
5377 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5378 Data Size: 335725 Bytes = 327 kB = 0 MB
5379 Load Address: 00000000
5380 Entry Point: 0000000c
5381 Verifying Checksum ... OK
5383 ## Checking Image at 40200000 ...
5384 Image Name: Simple Ramdisk Image
5385 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5386 Data Size: 566530 Bytes = 553 kB = 0 MB
5387 Load Address: 00000000
5388 Entry Point: 00000000
5389 Verifying Checksum ... OK
5391 => bootm 40100000 40200000
5392 ## Booting Linux kernel at 40100000 ...
5393 Image Name: 2.2.13 for initrd on TQM850L
5394 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5395 Data Size: 335725 Bytes = 327 kB = 0 MB
5396 Load Address: 00000000
5397 Entry Point: 0000000c
5398 Verifying Checksum ... OK
5399 Uncompressing Kernel Image ... OK
5400 ## Loading RAMDisk Image at 40200000 ...
5401 Image Name: Simple Ramdisk Image
5402 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5403 Data Size: 566530 Bytes = 553 kB = 0 MB
5404 Load Address: 00000000
5405 Entry Point: 00000000
5406 Verifying Checksum ... OK
5407 Loading Ramdisk ... OK
5408 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
5409 Boot arguments: root=/dev/ram
5410 time_init: decrementer frequency = 187500000/60
5411 Calibrating delay loop... 49.77 BogoMIPS
5413 RAMDISK: Compressed image found at block 0
5414 VFS: Mounted root (ext2 filesystem).
5418 Boot Linux and pass a flat device tree:
5421 First, U-Boot must be compiled with the appropriate defines. See the section
5422 titled "Linux Kernel Interface" above for a more in depth explanation. The
5423 following is an example of how to start a kernel and pass an updated
5429 oft=oftrees/mpc8540ads.dtb
5430 => tftp $oftaddr $oft
5431 Speed: 1000, full duplex
5433 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5434 Filename 'oftrees/mpc8540ads.dtb'.
5435 Load address: 0x300000
5438 Bytes transferred = 4106 (100a hex)
5439 => tftp $loadaddr $bootfile
5440 Speed: 1000, full duplex
5442 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5444 Load address: 0x200000
5445 Loading:############
5447 Bytes transferred = 1029407 (fb51f hex)
5452 => bootm $loadaddr - $oftaddr
5453 ## Booting image at 00200000 ...
5454 Image Name: Linux-2.6.17-dirty
5455 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5456 Data Size: 1029343 Bytes = 1005.2 kB
5457 Load Address: 00000000
5458 Entry Point: 00000000
5459 Verifying Checksum ... OK
5460 Uncompressing Kernel Image ... OK
5461 Booting using flat device tree at 0x300000
5462 Using MPC85xx ADS machine description
5463 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5467 More About U-Boot Image Types:
5468 ------------------------------
5470 U-Boot supports the following image types:
5472 "Standalone Programs" are directly runnable in the environment
5473 provided by U-Boot; it is expected that (if they behave
5474 well) you can continue to work in U-Boot after return from
5475 the Standalone Program.
5476 "OS Kernel Images" are usually images of some Embedded OS which
5477 will take over control completely. Usually these programs
5478 will install their own set of exception handlers, device
5479 drivers, set up the MMU, etc. - this means, that you cannot
5480 expect to re-enter U-Boot except by resetting the CPU.
5481 "RAMDisk Images" are more or less just data blocks, and their
5482 parameters (address, size) are passed to an OS kernel that is
5484 "Multi-File Images" contain several images, typically an OS
5485 (Linux) kernel image and one or more data images like
5486 RAMDisks. This construct is useful for instance when you want
5487 to boot over the network using BOOTP etc., where the boot
5488 server provides just a single image file, but you want to get
5489 for instance an OS kernel and a RAMDisk image.
5491 "Multi-File Images" start with a list of image sizes, each
5492 image size (in bytes) specified by an "uint32_t" in network
5493 byte order. This list is terminated by an "(uint32_t)0".
5494 Immediately after the terminating 0 follow the images, one by
5495 one, all aligned on "uint32_t" boundaries (size rounded up to
5496 a multiple of 4 bytes).
5498 "Firmware Images" are binary images containing firmware (like
5499 U-Boot or FPGA images) which usually will be programmed to
5502 "Script files" are command sequences that will be executed by
5503 U-Boot's command interpreter; this feature is especially
5504 useful when you configure U-Boot to use a real shell (hush)
5505 as command interpreter.
5507 Booting the Linux zImage:
5508 -------------------------
5510 On some platforms, it's possible to boot Linux zImage. This is done
5511 using the "bootz" command. The syntax of "bootz" command is the same
5512 as the syntax of "bootm" command.
5514 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5515 kernel with raw initrd images. The syntax is slightly different, the
5516 address of the initrd must be augmented by it's size, in the following
5517 format: "<initrd addres>:<initrd size>".
5523 One of the features of U-Boot is that you can dynamically load and
5524 run "standalone" applications, which can use some resources of
5525 U-Boot like console I/O functions or interrupt services.
5527 Two simple examples are included with the sources:
5532 'examples/hello_world.c' contains a small "Hello World" Demo
5533 application; it is automatically compiled when you build U-Boot.
5534 It's configured to run at address 0x00040004, so you can play with it
5538 ## Ready for S-Record download ...
5539 ~>examples/hello_world.srec
5540 1 2 3 4 5 6 7 8 9 10 11 ...
5541 [file transfer complete]
5543 ## Start Addr = 0x00040004
5545 => go 40004 Hello World! This is a test.
5546 ## Starting application at 0x00040004 ...
5557 Hit any key to exit ...
5559 ## Application terminated, rc = 0x0
5561 Another example, which demonstrates how to register a CPM interrupt
5562 handler with the U-Boot code, can be found in 'examples/timer.c'.
5563 Here, a CPM timer is set up to generate an interrupt every second.
5564 The interrupt service routine is trivial, just printing a '.'
5565 character, but this is just a demo program. The application can be
5566 controlled by the following keys:
5568 ? - print current values og the CPM Timer registers
5569 b - enable interrupts and start timer
5570 e - stop timer and disable interrupts
5571 q - quit application
5574 ## Ready for S-Record download ...
5575 ~>examples/timer.srec
5576 1 2 3 4 5 6 7 8 9 10 11 ...
5577 [file transfer complete]
5579 ## Start Addr = 0x00040004
5582 ## Starting application at 0x00040004 ...
5585 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5588 [q, b, e, ?] Set interval 1000000 us
5591 [q, b, e, ?] ........
5592 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5595 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5598 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5601 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5603 [q, b, e, ?] ...Stopping timer
5605 [q, b, e, ?] ## Application terminated, rc = 0x0
5611 Over time, many people have reported problems when trying to use the
5612 "minicom" terminal emulation program for serial download. I (wd)
5613 consider minicom to be broken, and recommend not to use it. Under
5614 Unix, I recommend to use C-Kermit for general purpose use (and
5615 especially for kermit binary protocol download ("loadb" command), and
5616 use "cu" for S-Record download ("loads" command). See
5617 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5618 for help with kermit.
5621 Nevertheless, if you absolutely want to use it try adding this
5622 configuration to your "File transfer protocols" section:
5624 Name Program Name U/D FullScr IO-Red. Multi
5625 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5626 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5632 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5633 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5635 Building requires a cross environment; it is known to work on
5636 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5637 need gmake since the Makefiles are not compatible with BSD make).
5638 Note that the cross-powerpc package does not install include files;
5639 attempting to build U-Boot will fail because <machine/ansi.h> is
5640 missing. This file has to be installed and patched manually:
5642 # cd /usr/pkg/cross/powerpc-netbsd/include
5644 # ln -s powerpc machine
5645 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5646 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5648 Native builds *don't* work due to incompatibilities between native
5649 and U-Boot include files.
5651 Booting assumes that (the first part of) the image booted is a
5652 stage-2 loader which in turn loads and then invokes the kernel
5653 proper. Loader sources will eventually appear in the NetBSD source
5654 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5655 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5658 Implementation Internals:
5659 =========================
5661 The following is not intended to be a complete description of every
5662 implementation detail. However, it should help to understand the
5663 inner workings of U-Boot and make it easier to port it to custom
5667 Initial Stack, Global Data:
5668 ---------------------------
5670 The implementation of U-Boot is complicated by the fact that U-Boot
5671 starts running out of ROM (flash memory), usually without access to
5672 system RAM (because the memory controller is not initialized yet).
5673 This means that we don't have writable Data or BSS segments, and BSS
5674 is not initialized as zero. To be able to get a C environment working
5675 at all, we have to allocate at least a minimal stack. Implementation
5676 options for this are defined and restricted by the CPU used: Some CPU
5677 models provide on-chip memory (like the IMMR area on MPC8xx and
5678 MPC826x processors), on others (parts of) the data cache can be
5679 locked as (mis-) used as memory, etc.
5681 Chris Hallinan posted a good summary of these issues to the
5682 U-Boot mailing list:
5684 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5685 From: "Chris Hallinan" <clh@net1plus.com>
5686 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5689 Correct me if I'm wrong, folks, but the way I understand it
5690 is this: Using DCACHE as initial RAM for Stack, etc, does not
5691 require any physical RAM backing up the cache. The cleverness
5692 is that the cache is being used as a temporary supply of
5693 necessary storage before the SDRAM controller is setup. It's
5694 beyond the scope of this list to explain the details, but you
5695 can see how this works by studying the cache architecture and
5696 operation in the architecture and processor-specific manuals.
5698 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5699 is another option for the system designer to use as an
5700 initial stack/RAM area prior to SDRAM being available. Either
5701 option should work for you. Using CS 4 should be fine if your
5702 board designers haven't used it for something that would
5703 cause you grief during the initial boot! It is frequently not
5706 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5707 with your processor/board/system design. The default value
5708 you will find in any recent u-boot distribution in
5709 walnut.h should work for you. I'd set it to a value larger
5710 than your SDRAM module. If you have a 64MB SDRAM module, set
5711 it above 400_0000. Just make sure your board has no resources
5712 that are supposed to respond to that address! That code in
5713 start.S has been around a while and should work as is when
5714 you get the config right.
5719 It is essential to remember this, since it has some impact on the C
5720 code for the initialization procedures:
5722 * Initialized global data (data segment) is read-only. Do not attempt
5725 * Do not use any uninitialized global data (or implicitely initialized
5726 as zero data - BSS segment) at all - this is undefined, initiali-
5727 zation is performed later (when relocating to RAM).
5729 * Stack space is very limited. Avoid big data buffers or things like
5732 Having only the stack as writable memory limits means we cannot use
5733 normal global data to share information beween the code. But it
5734 turned out that the implementation of U-Boot can be greatly
5735 simplified by making a global data structure (gd_t) available to all
5736 functions. We could pass a pointer to this data as argument to _all_
5737 functions, but this would bloat the code. Instead we use a feature of
5738 the GCC compiler (Global Register Variables) to share the data: we
5739 place a pointer (gd) to the global data into a register which we
5740 reserve for this purpose.
5742 When choosing a register for such a purpose we are restricted by the
5743 relevant (E)ABI specifications for the current architecture, and by
5744 GCC's implementation.
5746 For PowerPC, the following registers have specific use:
5748 R2: reserved for system use
5749 R3-R4: parameter passing and return values
5750 R5-R10: parameter passing
5751 R13: small data area pointer
5755 (U-Boot also uses R12 as internal GOT pointer. r12
5756 is a volatile register so r12 needs to be reset when
5757 going back and forth between asm and C)
5759 ==> U-Boot will use R2 to hold a pointer to the global data
5761 Note: on PPC, we could use a static initializer (since the
5762 address of the global data structure is known at compile time),
5763 but it turned out that reserving a register results in somewhat
5764 smaller code - although the code savings are not that big (on
5765 average for all boards 752 bytes for the whole U-Boot image,
5766 624 text + 127 data).
5768 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5769 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5771 ==> U-Boot will use P3 to hold a pointer to the global data
5773 On ARM, the following registers are used:
5775 R0: function argument word/integer result
5776 R1-R3: function argument word
5777 R9: platform specific
5778 R10: stack limit (used only if stack checking is enabled)
5779 R11: argument (frame) pointer
5780 R12: temporary workspace
5783 R15: program counter
5785 ==> U-Boot will use R9 to hold a pointer to the global data
5787 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5789 On Nios II, the ABI is documented here:
5790 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5792 ==> U-Boot will use gp to hold a pointer to the global data
5794 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5795 to access small data sections, so gp is free.
5797 On NDS32, the following registers are used:
5799 R0-R1: argument/return
5801 R15: temporary register for assembler
5802 R16: trampoline register
5803 R28: frame pointer (FP)
5804 R29: global pointer (GP)
5805 R30: link register (LP)
5806 R31: stack pointer (SP)
5807 PC: program counter (PC)
5809 ==> U-Boot will use R10 to hold a pointer to the global data
5811 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5812 or current versions of GCC may "optimize" the code too much.
5817 U-Boot runs in system state and uses physical addresses, i.e. the
5818 MMU is not used either for address mapping nor for memory protection.
5820 The available memory is mapped to fixed addresses using the memory
5821 controller. In this process, a contiguous block is formed for each
5822 memory type (Flash, SDRAM, SRAM), even when it consists of several
5823 physical memory banks.
5825 U-Boot is installed in the first 128 kB of the first Flash bank (on
5826 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5827 booting and sizing and initializing DRAM, the code relocates itself
5828 to the upper end of DRAM. Immediately below the U-Boot code some
5829 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5830 configuration setting]. Below that, a structure with global Board
5831 Info data is placed, followed by the stack (growing downward).
5833 Additionally, some exception handler code is copied to the low 8 kB
5834 of DRAM (0x00000000 ... 0x00001FFF).
5836 So a typical memory configuration with 16 MB of DRAM could look like
5839 0x0000 0000 Exception Vector code
5842 0x0000 2000 Free for Application Use
5848 0x00FB FF20 Monitor Stack (Growing downward)
5849 0x00FB FFAC Board Info Data and permanent copy of global data
5850 0x00FC 0000 Malloc Arena
5853 0x00FE 0000 RAM Copy of Monitor Code
5854 ... eventually: LCD or video framebuffer
5855 ... eventually: pRAM (Protected RAM - unchanged by reset)
5856 0x00FF FFFF [End of RAM]
5859 System Initialization:
5860 ----------------------
5862 In the reset configuration, U-Boot starts at the reset entry point
5863 (on most PowerPC systems at address 0x00000100). Because of the reset
5864 configuration for CS0# this is a mirror of the onboard Flash memory.
5865 To be able to re-map memory U-Boot then jumps to its link address.
5866 To be able to implement the initialization code in C, a (small!)
5867 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5868 which provide such a feature like MPC8xx or MPC8260), or in a locked
5869 part of the data cache. After that, U-Boot initializes the CPU core,
5870 the caches and the SIU.
5872 Next, all (potentially) available memory banks are mapped using a
5873 preliminary mapping. For example, we put them on 512 MB boundaries
5874 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5875 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5876 programmed for SDRAM access. Using the temporary configuration, a
5877 simple memory test is run that determines the size of the SDRAM
5880 When there is more than one SDRAM bank, and the banks are of
5881 different size, the largest is mapped first. For equal size, the first
5882 bank (CS2#) is mapped first. The first mapping is always for address
5883 0x00000000, with any additional banks following immediately to create
5884 contiguous memory starting from 0.
5886 Then, the monitor installs itself at the upper end of the SDRAM area
5887 and allocates memory for use by malloc() and for the global Board
5888 Info data; also, the exception vector code is copied to the low RAM
5889 pages, and the final stack is set up.
5891 Only after this relocation will you have a "normal" C environment;
5892 until that you are restricted in several ways, mostly because you are
5893 running from ROM, and because the code will have to be relocated to a
5897 U-Boot Porting Guide:
5898 ----------------------
5900 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5904 int main(int argc, char *argv[])
5906 sighandler_t no_more_time;
5908 signal(SIGALRM, no_more_time);
5909 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5911 if (available_money > available_manpower) {
5912 Pay consultant to port U-Boot;
5916 Download latest U-Boot source;
5918 Subscribe to u-boot mailing list;
5921 email("Hi, I am new to U-Boot, how do I get started?");
5924 Read the README file in the top level directory;
5925 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5926 Read applicable doc/*.README;
5927 Read the source, Luke;
5928 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5931 if (available_money > toLocalCurrency ($2500))
5934 Add a lot of aggravation and time;
5936 if (a similar board exists) { /* hopefully... */
5937 cp -a board/<similar> board/<myboard>
5938 cp include/configs/<similar>.h include/configs/<myboard>.h
5940 Create your own board support subdirectory;
5941 Create your own board include/configs/<myboard>.h file;
5943 Edit new board/<myboard> files
5944 Edit new include/configs/<myboard>.h
5949 Add / modify source code;
5953 email("Hi, I am having problems...");
5955 Send patch file to the U-Boot email list;
5956 if (reasonable critiques)
5957 Incorporate improvements from email list code review;
5959 Defend code as written;
5965 void no_more_time (int sig)
5974 All contributions to U-Boot should conform to the Linux kernel
5975 coding style; see the file "Documentation/CodingStyle" and the script
5976 "scripts/Lindent" in your Linux kernel source directory.
5978 Source files originating from a different project (for example the
5979 MTD subsystem) are generally exempt from these guidelines and are not
5980 reformated to ease subsequent migration to newer versions of those
5983 Please note that U-Boot is implemented in C (and to some small parts in
5984 Assembler); no C++ is used, so please do not use C++ style comments (//)
5987 Please also stick to the following formatting rules:
5988 - remove any trailing white space
5989 - use TAB characters for indentation and vertical alignment, not spaces
5990 - make sure NOT to use DOS '\r\n' line feeds
5991 - do not add more than 2 consecutive empty lines to source files
5992 - do not add trailing empty lines to source files
5994 Submissions which do not conform to the standards may be returned
5995 with a request to reformat the changes.
6001 Since the number of patches for U-Boot is growing, we need to
6002 establish some rules. Submissions which do not conform to these rules
6003 may be rejected, even when they contain important and valuable stuff.
6005 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6007 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6008 see http://lists.denx.de/mailman/listinfo/u-boot
6010 When you send a patch, please include the following information with
6013 * For bug fixes: a description of the bug and how your patch fixes
6014 this bug. Please try to include a way of demonstrating that the
6015 patch actually fixes something.
6017 * For new features: a description of the feature and your
6020 * A CHANGELOG entry as plaintext (separate from the patch)
6022 * For major contributions, your entry to the CREDITS file
6024 * When you add support for a new board, don't forget to add a
6025 maintainer e-mail address to the boards.cfg file, too.
6027 * If your patch adds new configuration options, don't forget to
6028 document these in the README file.
6030 * The patch itself. If you are using git (which is *strongly*
6031 recommended) you can easily generate the patch using the
6032 "git format-patch". If you then use "git send-email" to send it to
6033 the U-Boot mailing list, you will avoid most of the common problems
6034 with some other mail clients.
6036 If you cannot use git, use "diff -purN OLD NEW". If your version of
6037 diff does not support these options, then get the latest version of
6040 The current directory when running this command shall be the parent
6041 directory of the U-Boot source tree (i. e. please make sure that
6042 your patch includes sufficient directory information for the
6045 We prefer patches as plain text. MIME attachments are discouraged,
6046 and compressed attachments must not be used.
6048 * If one logical set of modifications affects or creates several
6049 files, all these changes shall be submitted in a SINGLE patch file.
6051 * Changesets that contain different, unrelated modifications shall be
6052 submitted as SEPARATE patches, one patch per changeset.
6057 * Before sending the patch, run the MAKEALL script on your patched
6058 source tree and make sure that no errors or warnings are reported
6059 for any of the boards.
6061 * Keep your modifications to the necessary minimum: A patch
6062 containing several unrelated changes or arbitrary reformats will be
6063 returned with a request to re-formatting / split it.
6065 * If you modify existing code, make sure that your new code does not
6066 add to the memory footprint of the code ;-) Small is beautiful!
6067 When adding new features, these should compile conditionally only
6068 (using #ifdef), and the resulting code with the new feature
6069 disabled must not need more memory than the old code without your
6072 * Remember that there is a size limit of 100 kB per message on the
6073 u-boot mailing list. Bigger patches will be moderated. If they are
6074 reasonable and not too big, they will be acknowledged. But patches
6075 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob