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 /ixp Files specific to Intel XScale IXP CPUs
145 /pxa Files specific to Intel XScale PXA CPUs
146 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
147 /lib Architecture specific library files
148 /avr32 Files generic to AVR32 architecture
149 /cpu CPU specific files
150 /lib Architecture specific library files
151 /blackfin Files generic to Analog Devices Blackfin architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /m68k Files generic to m68k architecture
155 /cpu CPU specific files
156 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 /lib Architecture specific library files
162 /microblaze Files generic to microblaze architecture
163 /cpu CPU specific files
164 /lib Architecture specific library files
165 /mips Files generic to MIPS architecture
166 /cpu CPU specific files
167 /mips32 Files specific to MIPS32 CPUs
168 /xburst Files specific to Ingenic XBurst CPUs
169 /lib Architecture specific library files
170 /nds32 Files generic to NDS32 architecture
171 /cpu CPU specific files
172 /n1213 Files specific to Andes Technology N1213 CPUs
173 /lib Architecture specific library files
174 /nios2 Files generic to Altera NIOS2 architecture
175 /cpu CPU specific files
176 /lib Architecture specific library files
177 /openrisc Files generic to OpenRISC architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /powerpc Files generic to PowerPC architecture
181 /cpu CPU specific files
182 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
183 /mpc5xx Files specific to Freescale MPC5xx CPUs
184 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
185 /mpc8xx Files specific to Freescale MPC8xx CPUs
186 /mpc824x Files specific to Freescale MPC824x CPUs
187 /mpc8260 Files specific to Freescale MPC8260 CPUs
188 /mpc85xx Files specific to Freescale MPC85xx CPUs
189 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
190 /lib Architecture specific library files
191 /sh Files generic to SH architecture
192 /cpu CPU specific files
193 /sh2 Files specific to sh2 CPUs
194 /sh3 Files specific to sh3 CPUs
195 /sh4 Files specific to sh4 CPUs
196 /lib Architecture specific library files
197 /sparc Files generic to SPARC architecture
198 /cpu CPU specific files
199 /leon2 Files specific to Gaisler LEON2 SPARC CPU
200 /leon3 Files specific to Gaisler LEON3 SPARC CPU
201 /lib Architecture specific library files
202 /x86 Files generic to x86 architecture
203 /cpu CPU specific files
204 /lib Architecture specific library files
205 /api Machine/arch independent API for external apps
206 /board Board dependent files
207 /common Misc architecture independent functions
208 /disk Code for disk drive partition handling
209 /doc Documentation (don't expect too much)
210 /drivers Commonly used device drivers
211 /dts Contains Makefile for building internal U-Boot fdt.
212 /examples Example code for standalone applications, etc.
213 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
214 /include Header Files
215 /lib Files generic to all architectures
216 /libfdt Library files to support flattened device trees
217 /lzma Library files to support LZMA decompression
218 /lzo Library files to support LZO decompression
220 /post Power On Self Test
221 /spl Secondary Program Loader framework
222 /tools Tools to build S-Record or U-Boot images, etc.
224 Software Configuration:
225 =======================
227 Configuration is usually done using C preprocessor defines; the
228 rationale behind that is to avoid dead code whenever possible.
230 There are two classes of configuration variables:
232 * Configuration _OPTIONS_:
233 These are selectable by the user and have names beginning with
236 * Configuration _SETTINGS_:
237 These depend on the hardware etc. and should not be meddled with if
238 you don't know what you're doing; they have names beginning with
241 Later we will add a configuration tool - probably similar to or even
242 identical to what's used for the Linux kernel. Right now, we have to
243 do the configuration by hand, which means creating some symbolic
244 links and editing some configuration files. We use the TQM8xxL boards
248 Selection of Processor Architecture and Board Type:
249 ---------------------------------------------------
251 For all supported boards there are ready-to-use default
252 configurations available; just type "make <board_name>_config".
254 Example: For a TQM823L module type:
259 For the Cogent platform, you need to specify the CPU type as well;
260 e.g. "make cogent_mpc8xx_config". And also configure the cogent
261 directory according to the instructions in cogent/README.
264 Configuration Options:
265 ----------------------
267 Configuration depends on the combination of board and CPU type; all
268 such information is kept in a configuration file
269 "include/configs/<board_name>.h".
271 Example: For a TQM823L module, all configuration settings are in
272 "include/configs/TQM823L.h".
275 Many of the options are named exactly as the corresponding Linux
276 kernel configuration options. The intention is to make it easier to
277 build a config tool - later.
280 The following options need to be configured:
282 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
284 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
286 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
287 Define exactly one, e.g. CONFIG_ATSTK1002
289 - CPU Module Type: (if CONFIG_COGENT is defined)
290 Define exactly one of
292 --- FIXME --- not tested yet:
293 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
294 CONFIG_CMA287_23, CONFIG_CMA287_50
296 - Motherboard Type: (if CONFIG_COGENT is defined)
297 Define exactly one of
298 CONFIG_CMA101, CONFIG_CMA102
300 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
301 Define one or more of
304 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
305 Define one or more of
306 CONFIG_LCD_HEARTBEAT - update a character position on
307 the LCD display every second with
310 - Board flavour: (if CONFIG_MPC8260ADS is defined)
313 CONFIG_SYS_8260ADS - original MPC8260ADS
314 CONFIG_SYS_8266ADS - MPC8266ADS
315 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
316 CONFIG_SYS_8272ADS - MPC8272ADS
318 - Marvell Family Member
319 CONFIG_SYS_MVFS - define it if you want to enable
320 multiple fs option at one time
321 for marvell soc family
323 - MPC824X Family Member (if CONFIG_MPC824X is defined)
324 Define exactly one of
325 CONFIG_MPC8240, CONFIG_MPC8245
327 - 8xx CPU Options: (if using an MPC8xx CPU)
328 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
329 get_gclk_freq() cannot work
330 e.g. if there is no 32KHz
331 reference PIT/RTC clock
332 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
335 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
336 CONFIG_SYS_8xx_CPUCLK_MIN
337 CONFIG_SYS_8xx_CPUCLK_MAX
338 CONFIG_8xx_CPUCLK_DEFAULT
339 See doc/README.MPC866
341 CONFIG_SYS_MEASURE_CPUCLK
343 Define this to measure the actual CPU clock instead
344 of relying on the correctness of the configured
345 values. Mostly useful for board bringup to make sure
346 the PLL is locked at the intended frequency. Note
347 that this requires a (stable) reference clock (32 kHz
348 RTC clock or CONFIG_SYS_8XX_XIN)
350 CONFIG_SYS_DELAYED_ICACHE
352 Define this option if you want to enable the
353 ICache only when Code runs from RAM.
358 Specifies that the core is a 64-bit PowerPC implementation (implements
359 the "64" category of the Power ISA). This is necessary for ePAPR
360 compliance, among other possible reasons.
362 CONFIG_SYS_FSL_TBCLK_DIV
364 Defines the core time base clock divider ratio compared to the
365 system clock. On most PQ3 devices this is 8, on newer QorIQ
366 devices it can be 16 or 32. The ratio varies from SoC to Soc.
368 CONFIG_SYS_FSL_PCIE_COMPAT
370 Defines the string to utilize when trying to match PCIe device
371 tree nodes for the given platform.
373 CONFIG_SYS_PPC_E500_DEBUG_TLB
375 Enables a temporary TLB entry to be used during boot to work
376 around limitations in e500v1 and e500v2 external debugger
377 support. This reduces the portions of the boot code where
378 breakpoints and single stepping do not work. The value of this
379 symbol should be set to the TLB1 entry to be used for this
382 CONFIG_SYS_FSL_ERRATUM_A004510
384 Enables a workaround for erratum A004510. If set,
385 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
386 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
391 Defines one or two SoC revisions (low 8 bits of SVR)
392 for which the A004510 workaround should be applied.
394 The rest of SVR is either not relevant to the decision
395 of whether the erratum is present (e.g. p2040 versus
396 p2041) or is implied by the build target, which controls
397 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
399 See Freescale App Note 4493 for more information about
402 CONFIG_A003399_NOR_WORKAROUND
403 Enables a workaround for IFC erratum A003399. It is only
404 requred during NOR boot.
406 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
408 This is the value to write into CCSR offset 0x18600
409 according to the A004510 workaround.
411 CONFIG_SYS_FSL_DSP_DDR_ADDR
412 This value denotes start offset of DDR memory which is
413 connected exclusively to the DSP cores.
415 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
416 This value denotes start offset of M2 memory
417 which is directly connected to the DSP core.
419 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
420 This value denotes start offset of M3 memory which is directly
421 connected to the DSP core.
423 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
424 This value denotes start offset of DSP CCSR space.
426 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
427 Single Source Clock is clocking mode present in some of FSL SoC's.
428 In this mode, a single differential clock is used to supply
429 clocks to the sysclock, ddrclock and usbclock.
431 - Generic CPU options:
432 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
434 Defines the endianess of the CPU. Implementation of those
435 values is arch specific.
438 Freescale DDR driver in use. This type of DDR controller is
439 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
442 CONFIG_SYS_FSL_DDR_ADDR
443 Freescale DDR memory-mapped register base.
445 CONFIG_SYS_FSL_DDR_EMU
446 Specify emulator support for DDR. Some DDR features such as
447 deskew training are not available.
449 CONFIG_SYS_FSL_DDRC_GEN1
450 Freescale DDR1 controller.
452 CONFIG_SYS_FSL_DDRC_GEN2
453 Freescale DDR2 controller.
455 CONFIG_SYS_FSL_DDRC_GEN3
456 Freescale DDR3 controller.
458 CONFIG_SYS_FSL_DDRC_ARM_GEN3
459 Freescale DDR3 controller for ARM-based SoCs.
462 Board config to use DDR1. It can be enabled for SoCs with
463 Freescale DDR1 or DDR2 controllers, depending on the board
467 Board config to use DDR2. It can be eanbeld for SoCs with
468 Freescale DDR2 or DDR3 controllers, depending on the board
472 Board config to use DDR3. It can be enabled for SoCs with
473 Freescale DDR3 controllers.
475 CONFIG_SYS_FSL_PBL_PBI
476 It enables addition of RCW (Power on reset configuration) in built image.
477 Please refer doc/README.pblimage for more details
479 CONFIG_SYS_FSL_PBL_RCW
480 It adds PBI(pre-boot instructions) commands in u-boot build image.
481 PBI commands can be used to configure SoC before it starts the execution.
482 Please refer doc/README.pblimage for more details
484 - Intel Monahans options:
485 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
487 Defines the Monahans run mode to oscillator
488 ratio. Valid values are 8, 16, 24, 31. The core
489 frequency is this value multiplied by 13 MHz.
491 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
493 Defines the Monahans turbo mode to oscillator
494 ratio. Valid values are 1 (default if undefined) and
495 2. The core frequency as calculated above is multiplied
499 CONFIG_SYS_INIT_SP_OFFSET
501 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
502 pointer. This is needed for the temporary stack before
505 CONFIG_SYS_MIPS_CACHE_MODE
507 Cache operation mode for the MIPS CPU.
508 See also arch/mips/include/asm/mipsregs.h.
510 CONF_CM_CACHABLE_NO_WA
513 CONF_CM_CACHABLE_NONCOHERENT
517 CONF_CM_CACHABLE_ACCELERATED
519 CONFIG_SYS_XWAY_EBU_BOOTCFG
521 Special option for Lantiq XWAY SoCs for booting from NOR flash.
522 See also arch/mips/cpu/mips32/start.S.
524 CONFIG_XWAY_SWAP_BYTES
526 Enable compilation of tools/xway-swap-bytes needed for Lantiq
527 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
528 be swapped if a flash programmer is used.
531 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
533 Select high exception vectors of the ARM core, e.g., do not
534 clear the V bit of the c1 register of CP15.
536 CONFIG_SYS_THUMB_BUILD
538 Use this flag to build U-Boot using the Thumb instruction
539 set for ARM architectures. Thumb instruction set provides
540 better code density. For ARM architectures that support
541 Thumb2 this flag will result in Thumb2 code generated by
544 CONFIG_ARM_ERRATA_716044
545 CONFIG_ARM_ERRATA_742230
546 CONFIG_ARM_ERRATA_743622
547 CONFIG_ARM_ERRATA_751472
549 If set, the workarounds for these ARM errata are applied early
550 during U-Boot startup. Note that these options force the
551 workarounds to be applied; no CPU-type/version detection
552 exists, unlike the similar options in the Linux kernel. Do not
553 set these options unless they apply!
558 The frequency of the timer returned by get_timer().
559 get_timer() must operate in milliseconds and this CONFIG
560 option must be set to 1000.
562 - Linux Kernel Interface:
565 U-Boot stores all clock information in Hz
566 internally. For binary compatibility with older Linux
567 kernels (which expect the clocks passed in the
568 bd_info data to be in MHz) the environment variable
569 "clocks_in_mhz" can be defined so that U-Boot
570 converts clock data to MHZ before passing it to the
572 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
573 "clocks_in_mhz=1" is automatically included in the
576 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
578 When transferring memsize parameter to linux, some versions
579 expect it to be in bytes, others in MB.
580 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
584 New kernel versions are expecting firmware settings to be
585 passed using flattened device trees (based on open firmware
589 * New libfdt-based support
590 * Adds the "fdt" command
591 * The bootm command automatically updates the fdt
593 OF_CPU - The proper name of the cpus node (only required for
594 MPC512X and MPC5xxx based boards).
595 OF_SOC - The proper name of the soc node (only required for
596 MPC512X and MPC5xxx based boards).
597 OF_TBCLK - The timebase frequency.
598 OF_STDOUT_PATH - The path to the console device
600 boards with QUICC Engines require OF_QE to set UCC MAC
603 CONFIG_OF_BOARD_SETUP
605 Board code has addition modification that it wants to make
606 to the flat device tree before handing it off to the kernel
610 This define fills in the correct boot CPU in the boot
611 param header, the default value is zero if undefined.
615 U-Boot can detect if an IDE device is present or not.
616 If not, and this new config option is activated, U-Boot
617 removes the ATA node from the DTS before booting Linux,
618 so the Linux IDE driver does not probe the device and
619 crash. This is needed for buggy hardware (uc101) where
620 no pull down resistor is connected to the signal IDE5V_DD7.
622 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
624 This setting is mandatory for all boards that have only one
625 machine type and must be used to specify the machine type
626 number as it appears in the ARM machine registry
627 (see http://www.arm.linux.org.uk/developer/machines/).
628 Only boards that have multiple machine types supported
629 in a single configuration file and the machine type is
630 runtime discoverable, do not have to use this setting.
632 - vxWorks boot parameters:
634 bootvx constructs a valid bootline using the following
635 environments variables: bootfile, ipaddr, serverip, hostname.
636 It loads the vxWorks image pointed bootfile.
638 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
639 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
640 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
641 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
643 CONFIG_SYS_VXWORKS_ADD_PARAMS
645 Add it at the end of the bootline. E.g "u=username pw=secret"
647 Note: If a "bootargs" environment is defined, it will overwride
648 the defaults discussed just above.
650 - Cache Configuration:
651 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
652 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
653 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
655 - Cache Configuration for ARM:
656 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
658 CONFIG_SYS_PL310_BASE - Physical base address of PL310
659 controller register space
664 Define this if you want support for Amba PrimeCell PL010 UARTs.
668 Define this if you want support for Amba PrimeCell PL011 UARTs.
672 If you have Amba PrimeCell PL011 UARTs, set this variable to
673 the clock speed of the UARTs.
677 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
678 define this to a list of base addresses for each (supported)
679 port. See e.g. include/configs/versatile.h
681 CONFIG_PL011_SERIAL_RLCR
683 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
684 have separate receive and transmit line control registers. Set
685 this variable to initialize the extra register.
687 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
689 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
690 boot loader that has already initialized the UART. Define this
691 variable to flush the UART at init time.
695 Depending on board, define exactly one serial port
696 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
697 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
698 console by defining CONFIG_8xx_CONS_NONE
700 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
701 port routines must be defined elsewhere
702 (i.e. serial_init(), serial_getc(), ...)
705 Enables console device for a color framebuffer. Needs following
706 defines (cf. smiLynxEM, i8042)
707 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
709 VIDEO_HW_RECTFILL graphic chip supports
712 VIDEO_HW_BITBLT graphic chip supports
713 bit-blit (cf. smiLynxEM)
714 VIDEO_VISIBLE_COLS visible pixel columns
716 VIDEO_VISIBLE_ROWS visible pixel rows
717 VIDEO_PIXEL_SIZE bytes per pixel
718 VIDEO_DATA_FORMAT graphic data format
719 (0-5, cf. cfb_console.c)
720 VIDEO_FB_ADRS framebuffer address
721 VIDEO_KBD_INIT_FCT keyboard int fct
722 (i.e. i8042_kbd_init())
723 VIDEO_TSTC_FCT test char fct
725 VIDEO_GETC_FCT get char fct
727 CONFIG_CONSOLE_CURSOR cursor drawing on/off
728 (requires blink timer
730 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
731 CONFIG_CONSOLE_TIME display time/date info in
733 (requires CONFIG_CMD_DATE)
734 CONFIG_VIDEO_LOGO display Linux logo in
736 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
737 linux_logo.h for logo.
738 Requires CONFIG_VIDEO_LOGO
739 CONFIG_CONSOLE_EXTRA_INFO
740 additional board info beside
743 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
744 a limited number of ANSI escape sequences (cursor control,
745 erase functions and limited graphics rendition control).
747 When CONFIG_CFB_CONSOLE is defined, video console is
748 default i/o. Serial console can be forced with
749 environment 'console=serial'.
751 When CONFIG_SILENT_CONSOLE is defined, all console
752 messages (by U-Boot and Linux!) can be silenced with
753 the "silent" environment variable. See
754 doc/README.silent for more information.
756 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
758 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
762 CONFIG_BAUDRATE - in bps
763 Select one of the baudrates listed in
764 CONFIG_SYS_BAUDRATE_TABLE, see below.
765 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
767 - Console Rx buffer length
768 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
769 the maximum receive buffer length for the SMC.
770 This option is actual only for 82xx and 8xx possible.
771 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
772 must be defined, to setup the maximum idle timeout for
775 - Pre-Console Buffer:
776 Prior to the console being initialised (i.e. serial UART
777 initialised etc) all console output is silently discarded.
778 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
779 buffer any console messages prior to the console being
780 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
781 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
782 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
783 bytes are output before the console is initialised, the
784 earlier bytes are discarded.
786 'Sane' compilers will generate smaller code if
787 CONFIG_PRE_CON_BUF_SZ is a power of 2
789 - Safe printf() functions
790 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
791 the printf() functions. These are defined in
792 include/vsprintf.h and include snprintf(), vsnprintf() and
793 so on. Code size increase is approximately 300-500 bytes.
794 If this option is not given then these functions will
795 silently discard their buffer size argument - this means
796 you are not getting any overflow checking in this case.
798 - Boot Delay: CONFIG_BOOTDELAY - in seconds
799 Delay before automatically booting the default image;
800 set to -1 to disable autoboot.
801 set to -2 to autoboot with no delay and not check for abort
802 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
804 See doc/README.autoboot for these options that
805 work with CONFIG_BOOTDELAY. None are required.
806 CONFIG_BOOT_RETRY_TIME
807 CONFIG_BOOT_RETRY_MIN
808 CONFIG_AUTOBOOT_KEYED
809 CONFIG_AUTOBOOT_PROMPT
810 CONFIG_AUTOBOOT_DELAY_STR
811 CONFIG_AUTOBOOT_STOP_STR
812 CONFIG_AUTOBOOT_DELAY_STR2
813 CONFIG_AUTOBOOT_STOP_STR2
814 CONFIG_ZERO_BOOTDELAY_CHECK
815 CONFIG_RESET_TO_RETRY
819 Only needed when CONFIG_BOOTDELAY is enabled;
820 define a command string that is automatically executed
821 when no character is read on the console interface
822 within "Boot Delay" after reset.
825 This can be used to pass arguments to the bootm
826 command. The value of CONFIG_BOOTARGS goes into the
827 environment value "bootargs".
829 CONFIG_RAMBOOT and CONFIG_NFSBOOT
830 The value of these goes into the environment as
831 "ramboot" and "nfsboot" respectively, and can be used
832 as a convenience, when switching between booting from
836 CONFIG_BOOTCOUNT_LIMIT
837 Implements a mechanism for detecting a repeating reboot
839 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
842 If no softreset save registers are found on the hardware
843 "bootcount" is stored in the environment. To prevent a
844 saveenv on all reboots, the environment variable
845 "upgrade_available" is used. If "upgrade_available" is
846 0, "bootcount" is always 0, if "upgrade_available" is
847 1 "bootcount" is incremented in the environment.
848 So the Userspace Applikation must set the "upgrade_available"
849 and "bootcount" variable to 0, if a boot was successfully.
854 When this option is #defined, the existence of the
855 environment variable "preboot" will be checked
856 immediately before starting the CONFIG_BOOTDELAY
857 countdown and/or running the auto-boot command resp.
858 entering interactive mode.
860 This feature is especially useful when "preboot" is
861 automatically generated or modified. For an example
862 see the LWMON board specific code: here "preboot" is
863 modified when the user holds down a certain
864 combination of keys on the (special) keyboard when
867 - Serial Download Echo Mode:
869 If defined to 1, all characters received during a
870 serial download (using the "loads" command) are
871 echoed back. This might be needed by some terminal
872 emulations (like "cu"), but may as well just take
873 time on others. This setting #define's the initial
874 value of the "loads_echo" environment variable.
876 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
878 Select one of the baudrates listed in
879 CONFIG_SYS_BAUDRATE_TABLE, see below.
882 Monitor commands can be included or excluded
883 from the build by using the #include files
884 <config_cmd_all.h> and #undef'ing unwanted
885 commands, or using <config_cmd_default.h>
886 and augmenting with additional #define's
889 The default command configuration includes all commands
890 except those marked below with a "*".
892 CONFIG_CMD_ASKENV * ask for env variable
893 CONFIG_CMD_BDI bdinfo
894 CONFIG_CMD_BEDBUG * Include BedBug Debugger
895 CONFIG_CMD_BMP * BMP support
896 CONFIG_CMD_BSP * Board specific commands
897 CONFIG_CMD_BOOTD bootd
898 CONFIG_CMD_CACHE * icache, dcache
899 CONFIG_CMD_CLK * clock command support
900 CONFIG_CMD_CONSOLE coninfo
901 CONFIG_CMD_CRC32 * crc32
902 CONFIG_CMD_DATE * support for RTC, date/time...
903 CONFIG_CMD_DHCP * DHCP support
904 CONFIG_CMD_DIAG * Diagnostics
905 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
906 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
907 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
908 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
909 CONFIG_CMD_DTT * Digital Therm and Thermostat
910 CONFIG_CMD_ECHO echo arguments
911 CONFIG_CMD_EDITENV edit env variable
912 CONFIG_CMD_EEPROM * EEPROM read/write support
913 CONFIG_CMD_ELF * bootelf, bootvx
914 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
915 CONFIG_CMD_ENV_FLAGS * display details about env flags
916 CONFIG_CMD_ENV_EXISTS * check existence of env variable
917 CONFIG_CMD_EXPORTENV * export the environment
918 CONFIG_CMD_EXT2 * ext2 command support
919 CONFIG_CMD_EXT4 * ext4 command support
920 CONFIG_CMD_SAVEENV saveenv
921 CONFIG_CMD_FDC * Floppy Disk Support
922 CONFIG_CMD_FAT * FAT command support
923 CONFIG_CMD_FDOS * Dos diskette Support
924 CONFIG_CMD_FLASH flinfo, erase, protect
925 CONFIG_CMD_FPGA FPGA device initialization support
926 CONFIG_CMD_FUSE * Device fuse support
927 CONFIG_CMD_GETTIME * Get time since boot
928 CONFIG_CMD_GO * the 'go' command (exec code)
929 CONFIG_CMD_GREPENV * search environment
930 CONFIG_CMD_HASH * calculate hash / digest
931 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
932 CONFIG_CMD_I2C * I2C serial bus support
933 CONFIG_CMD_IDE * IDE harddisk support
934 CONFIG_CMD_IMI iminfo
935 CONFIG_CMD_IMLS List all images found in NOR flash
936 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
937 CONFIG_CMD_IMMAP * IMMR dump support
938 CONFIG_CMD_IMPORTENV * import an environment
939 CONFIG_CMD_INI * import data from an ini file into the env
940 CONFIG_CMD_IRQ * irqinfo
941 CONFIG_CMD_ITEST Integer/string test of 2 values
942 CONFIG_CMD_JFFS2 * JFFS2 Support
943 CONFIG_CMD_KGDB * kgdb
944 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
945 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
947 CONFIG_CMD_LOADB loadb
948 CONFIG_CMD_LOADS loads
949 CONFIG_CMD_MD5SUM * print md5 message digest
950 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
951 CONFIG_CMD_MEMINFO * Display detailed memory information
952 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
954 CONFIG_CMD_MEMTEST * mtest
955 CONFIG_CMD_MISC Misc functions like sleep etc
956 CONFIG_CMD_MMC * MMC memory mapped support
957 CONFIG_CMD_MII * MII utility commands
958 CONFIG_CMD_MTDPARTS * MTD partition support
959 CONFIG_CMD_NAND * NAND support
960 CONFIG_CMD_NET bootp, tftpboot, rarpboot
961 CONFIG_CMD_NFS NFS support
962 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
963 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
964 CONFIG_CMD_PCI * pciinfo
965 CONFIG_CMD_PCMCIA * PCMCIA support
966 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
968 CONFIG_CMD_PORTIO * Port I/O
969 CONFIG_CMD_READ * Read raw data from partition
970 CONFIG_CMD_REGINFO * Register dump
971 CONFIG_CMD_RUN run command in env variable
972 CONFIG_CMD_SANDBOX * sb command to access sandbox features
973 CONFIG_CMD_SAVES * save S record dump
974 CONFIG_CMD_SCSI * SCSI Support
975 CONFIG_CMD_SDRAM * print SDRAM configuration information
976 (requires CONFIG_CMD_I2C)
977 CONFIG_CMD_SETGETDCR Support for DCR Register access
979 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
980 CONFIG_CMD_SHA1SUM * print sha1 memory digest
981 (requires CONFIG_CMD_MEMORY)
982 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
983 CONFIG_CMD_SOURCE "source" command Support
984 CONFIG_CMD_SPI * SPI serial bus support
985 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
986 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
987 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
988 CONFIG_CMD_TIMER * access to the system tick timer
989 CONFIG_CMD_USB * USB support
990 CONFIG_CMD_CDP * Cisco Discover Protocol support
991 CONFIG_CMD_MFSL * Microblaze FSL support
992 CONFIG_CMD_XIMG Load part of Multi Image
995 EXAMPLE: If you want all functions except of network
996 support you can write:
998 #include "config_cmd_all.h"
999 #undef CONFIG_CMD_NET
1002 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1004 Note: Don't enable the "icache" and "dcache" commands
1005 (configuration option CONFIG_CMD_CACHE) unless you know
1006 what you (and your U-Boot users) are doing. Data
1007 cache cannot be enabled on systems like the 8xx or
1008 8260 (where accesses to the IMMR region must be
1009 uncached), and it cannot be disabled on all other
1010 systems where we (mis-) use the data cache to hold an
1011 initial stack and some data.
1014 XXX - this list needs to get updated!
1016 - Regular expression support:
1018 If this variable is defined, U-Boot is linked against
1019 the SLRE (Super Light Regular Expression) library,
1020 which adds regex support to some commands, as for
1021 example "env grep" and "setexpr".
1025 If this variable is defined, U-Boot will use a device tree
1026 to configure its devices, instead of relying on statically
1027 compiled #defines in the board file. This option is
1028 experimental and only available on a few boards. The device
1029 tree is available in the global data as gd->fdt_blob.
1031 U-Boot needs to get its device tree from somewhere. This can
1032 be done using one of the two options below:
1035 If this variable is defined, U-Boot will embed a device tree
1036 binary in its image. This device tree file should be in the
1037 board directory and called <soc>-<board>.dts. The binary file
1038 is then picked up in board_init_f() and made available through
1039 the global data structure as gd->blob.
1042 If this variable is defined, U-Boot will build a device tree
1043 binary. It will be called u-boot.dtb. Architecture-specific
1044 code will locate it at run-time. Generally this works by:
1046 cat u-boot.bin u-boot.dtb >image.bin
1048 and in fact, U-Boot does this for you, creating a file called
1049 u-boot-dtb.bin which is useful in the common case. You can
1050 still use the individual files if you need something more
1055 If this variable is defined, it enables watchdog
1056 support for the SoC. There must be support in the SoC
1057 specific code for a watchdog. For the 8xx and 8260
1058 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1059 register. When supported for a specific SoC is
1060 available, then no further board specific code should
1061 be needed to use it.
1064 When using a watchdog circuitry external to the used
1065 SoC, then define this variable and provide board
1066 specific code for the "hw_watchdog_reset" function.
1069 CONFIG_VERSION_VARIABLE
1070 If this variable is defined, an environment variable
1071 named "ver" is created by U-Boot showing the U-Boot
1072 version as printed by the "version" command.
1073 Any change to this variable will be reverted at the
1078 When CONFIG_CMD_DATE is selected, the type of the RTC
1079 has to be selected, too. Define exactly one of the
1082 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1083 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1084 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1085 CONFIG_RTC_MC146818 - use MC146818 RTC
1086 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1087 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1088 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1089 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1090 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1091 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1092 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1093 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1096 Note that if the RTC uses I2C, then the I2C interface
1097 must also be configured. See I2C Support, below.
1100 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1102 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1103 chip-ngpio pairs that tell the PCA953X driver the number of
1104 pins supported by a particular chip.
1106 Note that if the GPIO device uses I2C, then the I2C interface
1107 must also be configured. See I2C Support, below.
1109 - Timestamp Support:
1111 When CONFIG_TIMESTAMP is selected, the timestamp
1112 (date and time) of an image is printed by image
1113 commands like bootm or iminfo. This option is
1114 automatically enabled when you select CONFIG_CMD_DATE .
1116 - Partition Labels (disklabels) Supported:
1117 Zero or more of the following:
1118 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1119 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1120 Intel architecture, USB sticks, etc.
1121 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1122 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1123 bootloader. Note 2TB partition limit; see
1125 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1127 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1128 CONFIG_CMD_SCSI) you must configure support for at
1129 least one non-MTD partition type as well.
1132 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1133 board configurations files but used nowhere!
1135 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1136 be performed by calling the function
1137 ide_set_reset(int reset)
1138 which has to be defined in a board specific file
1143 Set this to enable ATAPI support.
1148 Set this to enable support for disks larger than 137GB
1149 Also look at CONFIG_SYS_64BIT_LBA.
1150 Whithout these , LBA48 support uses 32bit variables and will 'only'
1151 support disks up to 2.1TB.
1153 CONFIG_SYS_64BIT_LBA:
1154 When enabled, makes the IDE subsystem use 64bit sector addresses.
1158 At the moment only there is only support for the
1159 SYM53C8XX SCSI controller; define
1160 CONFIG_SCSI_SYM53C8XX to enable it.
1162 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1163 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1164 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1165 maximum numbers of LUNs, SCSI ID's and target
1167 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1169 The environment variable 'scsidevs' is set to the number of
1170 SCSI devices found during the last scan.
1172 - NETWORK Support (PCI):
1174 Support for Intel 8254x/8257x gigabit chips.
1177 Utility code for direct access to the SPI bus on Intel 8257x.
1178 This does not do anything useful unless you set at least one
1179 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1181 CONFIG_E1000_SPI_GENERIC
1182 Allow generic access to the SPI bus on the Intel 8257x, for
1183 example with the "sspi" command.
1186 Management command for E1000 devices. When used on devices
1187 with SPI support you can reprogram the EEPROM from U-Boot.
1189 CONFIG_E1000_FALLBACK_MAC
1190 default MAC for empty EEPROM after production.
1193 Support for Intel 82557/82559/82559ER chips.
1194 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1195 write routine for first time initialisation.
1198 Support for Digital 2114x chips.
1199 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1200 modem chip initialisation (KS8761/QS6611).
1203 Support for National dp83815 chips.
1206 Support for National dp8382[01] gigabit chips.
1208 - NETWORK Support (other):
1210 CONFIG_DRIVER_AT91EMAC
1211 Support for AT91RM9200 EMAC.
1214 Define this to use reduced MII inteface
1216 CONFIG_DRIVER_AT91EMAC_QUIET
1217 If this defined, the driver is quiet.
1218 The driver doen't show link status messages.
1220 CONFIG_CALXEDA_XGMAC
1221 Support for the Calxeda XGMAC device
1224 Support for SMSC's LAN91C96 chips.
1226 CONFIG_LAN91C96_BASE
1227 Define this to hold the physical address
1228 of the LAN91C96's I/O space
1230 CONFIG_LAN91C96_USE_32_BIT
1231 Define this to enable 32 bit addressing
1234 Support for SMSC's LAN91C111 chip
1236 CONFIG_SMC91111_BASE
1237 Define this to hold the physical address
1238 of the device (I/O space)
1240 CONFIG_SMC_USE_32_BIT
1241 Define this if data bus is 32 bits
1243 CONFIG_SMC_USE_IOFUNCS
1244 Define this to use i/o functions instead of macros
1245 (some hardware wont work with macros)
1247 CONFIG_DRIVER_TI_EMAC
1248 Support for davinci emac
1250 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1251 Define this if you have more then 3 PHYs.
1254 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1256 CONFIG_FTGMAC100_EGIGA
1257 Define this to use GE link update with gigabit PHY.
1258 Define this if FTGMAC100 is connected to gigabit PHY.
1259 If your system has 10/100 PHY only, it might not occur
1260 wrong behavior. Because PHY usually return timeout or
1261 useless data when polling gigabit status and gigabit
1262 control registers. This behavior won't affect the
1263 correctnessof 10/100 link speed update.
1266 Support for SMSC's LAN911x and LAN921x chips
1269 Define this to hold the physical address
1270 of the device (I/O space)
1272 CONFIG_SMC911X_32_BIT
1273 Define this if data bus is 32 bits
1275 CONFIG_SMC911X_16_BIT
1276 Define this if data bus is 16 bits. If your processor
1277 automatically converts one 32 bit word to two 16 bit
1278 words you may also try CONFIG_SMC911X_32_BIT.
1281 Support for Renesas on-chip Ethernet controller
1283 CONFIG_SH_ETHER_USE_PORT
1284 Define the number of ports to be used
1286 CONFIG_SH_ETHER_PHY_ADDR
1287 Define the ETH PHY's address
1289 CONFIG_SH_ETHER_CACHE_WRITEBACK
1290 If this option is set, the driver enables cache flush.
1294 Support TPM devices.
1297 Support for i2c bus TPM devices. Only one device
1298 per system is supported at this time.
1300 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1301 Define the the i2c bus number for the TPM device
1303 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1304 Define the TPM's address on the i2c bus
1306 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1307 Define the burst count bytes upper limit
1309 CONFIG_TPM_ATMEL_TWI
1310 Support for Atmel TWI TPM device. Requires I2C support.
1313 Support for generic parallel port TPM devices. Only one device
1314 per system is supported at this time.
1316 CONFIG_TPM_TIS_BASE_ADDRESS
1317 Base address where the generic TPM device is mapped
1318 to. Contemporary x86 systems usually map it at
1322 Add tpm monitor functions.
1323 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1324 provides monitor access to authorized functions.
1327 Define this to enable the TPM support library which provides
1328 functional interfaces to some TPM commands.
1329 Requires support for a TPM device.
1331 CONFIG_TPM_AUTH_SESSIONS
1332 Define this to enable authorized functions in the TPM library.
1333 Requires CONFIG_TPM and CONFIG_SHA1.
1336 At the moment only the UHCI host controller is
1337 supported (PIP405, MIP405, MPC5200); define
1338 CONFIG_USB_UHCI to enable it.
1339 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1340 and define CONFIG_USB_STORAGE to enable the USB
1343 Supported are USB Keyboards and USB Floppy drives
1345 MPC5200 USB requires additional defines:
1347 for 528 MHz Clock: 0x0001bbbb
1351 for differential drivers: 0x00001000
1352 for single ended drivers: 0x00005000
1353 for differential drivers on PSC3: 0x00000100
1354 for single ended drivers on PSC3: 0x00004100
1355 CONFIG_SYS_USB_EVENT_POLL
1356 May be defined to allow interrupt polling
1357 instead of using asynchronous interrupts
1359 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1360 txfilltuning field in the EHCI controller on reset.
1362 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1363 interval for usb hub power-on delay.(minimum 100msec)
1366 Define the below if you wish to use the USB console.
1367 Once firmware is rebuilt from a serial console issue the
1368 command "setenv stdin usbtty; setenv stdout usbtty" and
1369 attach your USB cable. The Unix command "dmesg" should print
1370 it has found a new device. The environment variable usbtty
1371 can be set to gserial or cdc_acm to enable your device to
1372 appear to a USB host as a Linux gserial device or a
1373 Common Device Class Abstract Control Model serial device.
1374 If you select usbtty = gserial you should be able to enumerate
1376 # modprobe usbserial vendor=0xVendorID product=0xProductID
1377 else if using cdc_acm, simply setting the environment
1378 variable usbtty to be cdc_acm should suffice. The following
1379 might be defined in YourBoardName.h
1382 Define this to build a UDC device
1385 Define this to have a tty type of device available to
1386 talk to the UDC device
1389 Define this to enable the high speed support for usb
1390 device and usbtty. If this feature is enabled, a routine
1391 int is_usbd_high_speed(void)
1392 also needs to be defined by the driver to dynamically poll
1393 whether the enumeration has succeded at high speed or full
1396 CONFIG_SYS_CONSOLE_IS_IN_ENV
1397 Define this if you want stdin, stdout &/or stderr to
1401 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1402 Derive USB clock from external clock "blah"
1403 - CONFIG_SYS_USB_EXTC_CLK 0x02
1405 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1406 Derive USB clock from brgclk
1407 - CONFIG_SYS_USB_BRG_CLK 0x04
1409 If you have a USB-IF assigned VendorID then you may wish to
1410 define your own vendor specific values either in BoardName.h
1411 or directly in usbd_vendor_info.h. If you don't define
1412 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1413 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1414 should pretend to be a Linux device to it's target host.
1416 CONFIG_USBD_MANUFACTURER
1417 Define this string as the name of your company for
1418 - CONFIG_USBD_MANUFACTURER "my company"
1420 CONFIG_USBD_PRODUCT_NAME
1421 Define this string as the name of your product
1422 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1424 CONFIG_USBD_VENDORID
1425 Define this as your assigned Vendor ID from the USB
1426 Implementors Forum. This *must* be a genuine Vendor ID
1427 to avoid polluting the USB namespace.
1428 - CONFIG_USBD_VENDORID 0xFFFF
1430 CONFIG_USBD_PRODUCTID
1431 Define this as the unique Product ID
1433 - CONFIG_USBD_PRODUCTID 0xFFFF
1435 Some USB device drivers may need to check USB cable attachment.
1436 In this case you can enable following config in BoardName.h:
1437 CONFIG_USB_CABLE_CHECK
1438 This enables function definition:
1439 - usb_cable_connected() in include/usb.h
1440 Implementation of this function is board-specific.
1442 - ULPI Layer Support:
1443 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1444 the generic ULPI layer. The generic layer accesses the ULPI PHY
1445 via the platform viewport, so you need both the genric layer and
1446 the viewport enabled. Currently only Chipidea/ARC based
1447 viewport is supported.
1448 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1449 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1450 If your ULPI phy needs a different reference clock than the
1451 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1452 the appropriate value in Hz.
1455 The MMC controller on the Intel PXA is supported. To
1456 enable this define CONFIG_MMC. The MMC can be
1457 accessed from the boot prompt by mapping the device
1458 to physical memory similar to flash. Command line is
1459 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1460 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1463 Support for Renesas on-chip MMCIF controller
1465 CONFIG_SH_MMCIF_ADDR
1466 Define the base address of MMCIF registers
1469 Define the clock frequency for MMCIF
1471 - USB Device Firmware Update (DFU) class support:
1473 This enables the USB portion of the DFU USB class
1476 This enables the command "dfu" which is used to have
1477 U-Boot create a DFU class device via USB. This command
1478 requires that the "dfu_alt_info" environment variable be
1479 set and define the alt settings to expose to the host.
1482 This enables support for exposing (e)MMC devices via DFU.
1485 This enables support for exposing NAND devices via DFU.
1488 This enables support for exposing RAM via DFU.
1489 Note: DFU spec refer to non-volatile memory usage, but
1490 allow usages beyond the scope of spec - here RAM usage,
1491 one that would help mostly the developer.
1493 CONFIG_SYS_DFU_DATA_BUF_SIZE
1494 Dfu transfer uses a buffer before writing data to the
1495 raw storage device. Make the size (in bytes) of this buffer
1496 configurable. The size of this buffer is also configurable
1497 through the "dfu_bufsiz" environment variable.
1499 CONFIG_SYS_DFU_MAX_FILE_SIZE
1500 When updating files rather than the raw storage device,
1501 we use a static buffer to copy the file into and then write
1502 the buffer once we've been given the whole file. Define
1503 this to the maximum filesize (in bytes) for the buffer.
1504 Default is 4 MiB if undefined.
1506 - Journaling Flash filesystem support:
1507 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1508 CONFIG_JFFS2_NAND_DEV
1509 Define these for a default partition on a NAND device
1511 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1512 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1513 Define these for a default partition on a NOR device
1515 CONFIG_SYS_JFFS_CUSTOM_PART
1516 Define this to create an own partition. You have to provide a
1517 function struct part_info* jffs2_part_info(int part_num)
1519 If you define only one JFFS2 partition you may also want to
1520 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1521 to disable the command chpart. This is the default when you
1522 have not defined a custom partition
1524 - FAT(File Allocation Table) filesystem write function support:
1527 Define this to enable support for saving memory data as a
1528 file in FAT formatted partition.
1530 This will also enable the command "fatwrite" enabling the
1531 user to write files to FAT.
1533 CBFS (Coreboot Filesystem) support
1536 Define this to enable support for reading from a Coreboot
1537 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1543 Define this to enable standard (PC-Style) keyboard
1547 Standard PC keyboard driver with US (is default) and
1548 GERMAN key layout (switch via environment 'keymap=de') support.
1549 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1550 for cfb_console. Supports cursor blinking.
1553 Enables a Chrome OS keyboard using the CROS_EC interface.
1554 This uses CROS_EC to communicate with a second microcontroller
1555 which provides key scans on request.
1560 Define this to enable video support (for output to
1563 CONFIG_VIDEO_CT69000
1565 Enable Chips & Technologies 69000 Video chip
1567 CONFIG_VIDEO_SMI_LYNXEM
1568 Enable Silicon Motion SMI 712/710/810 Video chip. The
1569 video output is selected via environment 'videoout'
1570 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1573 For the CT69000 and SMI_LYNXEM drivers, videomode is
1574 selected via environment 'videomode'. Two different ways
1576 - "videomode=num" 'num' is a standard LiLo mode numbers.
1577 Following standard modes are supported (* is default):
1579 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1580 -------------+---------------------------------------------
1581 8 bits | 0x301* 0x303 0x305 0x161 0x307
1582 15 bits | 0x310 0x313 0x316 0x162 0x319
1583 16 bits | 0x311 0x314 0x317 0x163 0x31A
1584 24 bits | 0x312 0x315 0x318 ? 0x31B
1585 -------------+---------------------------------------------
1586 (i.e. setenv videomode 317; saveenv; reset;)
1588 - "videomode=bootargs" all the video parameters are parsed
1589 from the bootargs. (See drivers/video/videomodes.c)
1592 CONFIG_VIDEO_SED13806
1593 Enable Epson SED13806 driver. This driver supports 8bpp
1594 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1595 or CONFIG_VIDEO_SED13806_16BPP
1598 Enable the Freescale DIU video driver. Reference boards for
1599 SOCs that have a DIU should define this macro to enable DIU
1600 support, and should also define these other macros:
1606 CONFIG_VIDEO_SW_CURSOR
1607 CONFIG_VGA_AS_SINGLE_DEVICE
1609 CONFIG_VIDEO_BMP_LOGO
1611 The DIU driver will look for the 'video-mode' environment
1612 variable, and if defined, enable the DIU as a console during
1613 boot. See the documentation file README.video for a
1614 description of this variable.
1618 Enable the VGA video / BIOS for x86. The alternative if you
1619 are using coreboot is to use the coreboot frame buffer
1626 Define this to enable a custom keyboard support.
1627 This simply calls drv_keyboard_init() which must be
1628 defined in your board-specific files.
1629 The only board using this so far is RBC823.
1631 - LCD Support: CONFIG_LCD
1633 Define this to enable LCD support (for output to LCD
1634 display); also select one of the supported displays
1635 by defining one of these:
1639 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1641 CONFIG_NEC_NL6448AC33:
1643 NEC NL6448AC33-18. Active, color, single scan.
1645 CONFIG_NEC_NL6448BC20
1647 NEC NL6448BC20-08. 6.5", 640x480.
1648 Active, color, single scan.
1650 CONFIG_NEC_NL6448BC33_54
1652 NEC NL6448BC33-54. 10.4", 640x480.
1653 Active, color, single scan.
1657 Sharp 320x240. Active, color, single scan.
1658 It isn't 16x9, and I am not sure what it is.
1660 CONFIG_SHARP_LQ64D341
1662 Sharp LQ64D341 display, 640x480.
1663 Active, color, single scan.
1667 HLD1045 display, 640x480.
1668 Active, color, single scan.
1672 Optrex CBL50840-2 NF-FW 99 22 M5
1674 Hitachi LMG6912RPFC-00T
1678 320x240. Black & white.
1680 Normally display is black on white background; define
1681 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1683 CONFIG_LCD_ALIGNMENT
1685 Normally the LCD is page-aligned (tyically 4KB). If this is
1686 defined then the LCD will be aligned to this value instead.
1687 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1688 here, since it is cheaper to change data cache settings on
1689 a per-section basis.
1691 CONFIG_CONSOLE_SCROLL_LINES
1693 When the console need to be scrolled, this is the number of
1694 lines to scroll by. It defaults to 1. Increasing this makes
1695 the console jump but can help speed up operation when scrolling
1700 Support drawing of RLE8-compressed bitmaps on the LCD.
1704 Enables an 'i2c edid' command which can read EDID
1705 information over I2C from an attached LCD display.
1707 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1709 If this option is set, the environment is checked for
1710 a variable "splashimage". If found, the usual display
1711 of logo, copyright and system information on the LCD
1712 is suppressed and the BMP image at the address
1713 specified in "splashimage" is loaded instead. The
1714 console is redirected to the "nulldev", too. This
1715 allows for a "silent" boot where a splash screen is
1716 loaded very quickly after power-on.
1718 CONFIG_SPLASHIMAGE_GUARD
1720 If this option is set, then U-Boot will prevent the environment
1721 variable "splashimage" from being set to a problematic address
1722 (see README.displaying-bmps and README.arm-unaligned-accesses).
1723 This option is useful for targets where, due to alignment
1724 restrictions, an improperly aligned BMP image will cause a data
1725 abort. If you think you will not have problems with unaligned
1726 accesses (for example because your toolchain prevents them)
1727 there is no need to set this option.
1729 CONFIG_SPLASH_SCREEN_ALIGN
1731 If this option is set the splash image can be freely positioned
1732 on the screen. Environment variable "splashpos" specifies the
1733 position as "x,y". If a positive number is given it is used as
1734 number of pixel from left/top. If a negative number is given it
1735 is used as number of pixel from right/bottom. You can also
1736 specify 'm' for centering the image.
1739 setenv splashpos m,m
1740 => image at center of screen
1742 setenv splashpos 30,20
1743 => image at x = 30 and y = 20
1745 setenv splashpos -10,m
1746 => vertically centered image
1747 at x = dspWidth - bmpWidth - 9
1749 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1751 If this option is set, additionally to standard BMP
1752 images, gzipped BMP images can be displayed via the
1753 splashscreen support or the bmp command.
1755 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1757 If this option is set, 8-bit RLE compressed BMP images
1758 can be displayed via the splashscreen support or the
1761 - Do compresssing for memory range:
1764 If this option is set, it would use zlib deflate method
1765 to compress the specified memory at its best effort.
1767 - Compression support:
1770 Enabled by default to support gzip compressed images.
1774 If this option is set, support for bzip2 compressed
1775 images is included. If not, only uncompressed and gzip
1776 compressed images are supported.
1778 NOTE: the bzip2 algorithm requires a lot of RAM, so
1779 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1784 If this option is set, support for lzma compressed
1787 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1788 requires an amount of dynamic memory that is given by the
1791 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1793 Where lc and lp stand for, respectively, Literal context bits
1794 and Literal pos bits.
1796 This value is upper-bounded by 14MB in the worst case. Anyway,
1797 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1798 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1799 a very small buffer.
1801 Use the lzmainfo tool to determinate the lc and lp values and
1802 then calculate the amount of needed dynamic memory (ensuring
1803 the appropriate CONFIG_SYS_MALLOC_LEN value).
1807 If this option is set, support for LZO compressed images
1813 The address of PHY on MII bus.
1815 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1817 The clock frequency of the MII bus
1821 If this option is set, support for speed/duplex
1822 detection of gigabit PHY is included.
1824 CONFIG_PHY_RESET_DELAY
1826 Some PHY like Intel LXT971A need extra delay after
1827 reset before any MII register access is possible.
1828 For such PHY, set this option to the usec delay
1829 required. (minimum 300usec for LXT971A)
1831 CONFIG_PHY_CMD_DELAY (ppc4xx)
1833 Some PHY like Intel LXT971A need extra delay after
1834 command issued before MII status register can be read
1844 Define a default value for Ethernet address to use
1845 for the respective Ethernet interface, in case this
1846 is not determined automatically.
1851 Define a default value for the IP address to use for
1852 the default Ethernet interface, in case this is not
1853 determined through e.g. bootp.
1854 (Environment variable "ipaddr")
1856 - Server IP address:
1859 Defines a default value for the IP address of a TFTP
1860 server to contact when using the "tftboot" command.
1861 (Environment variable "serverip")
1863 CONFIG_KEEP_SERVERADDR
1865 Keeps the server's MAC address, in the env 'serveraddr'
1866 for passing to bootargs (like Linux's netconsole option)
1868 - Gateway IP address:
1871 Defines a default value for the IP address of the
1872 default router where packets to other networks are
1874 (Environment variable "gatewayip")
1879 Defines a default value for the subnet mask (or
1880 routing prefix) which is used to determine if an IP
1881 address belongs to the local subnet or needs to be
1882 forwarded through a router.
1883 (Environment variable "netmask")
1885 - Multicast TFTP Mode:
1888 Defines whether you want to support multicast TFTP as per
1889 rfc-2090; for example to work with atftp. Lets lots of targets
1890 tftp down the same boot image concurrently. Note: the Ethernet
1891 driver in use must provide a function: mcast() to join/leave a
1894 - BOOTP Recovery Mode:
1895 CONFIG_BOOTP_RANDOM_DELAY
1897 If you have many targets in a network that try to
1898 boot using BOOTP, you may want to avoid that all
1899 systems send out BOOTP requests at precisely the same
1900 moment (which would happen for instance at recovery
1901 from a power failure, when all systems will try to
1902 boot, thus flooding the BOOTP server. Defining
1903 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1904 inserted before sending out BOOTP requests. The
1905 following delays are inserted then:
1907 1st BOOTP request: delay 0 ... 1 sec
1908 2nd BOOTP request: delay 0 ... 2 sec
1909 3rd BOOTP request: delay 0 ... 4 sec
1911 BOOTP requests: delay 0 ... 8 sec
1913 - DHCP Advanced Options:
1914 You can fine tune the DHCP functionality by defining
1915 CONFIG_BOOTP_* symbols:
1917 CONFIG_BOOTP_SUBNETMASK
1918 CONFIG_BOOTP_GATEWAY
1919 CONFIG_BOOTP_HOSTNAME
1920 CONFIG_BOOTP_NISDOMAIN
1921 CONFIG_BOOTP_BOOTPATH
1922 CONFIG_BOOTP_BOOTFILESIZE
1925 CONFIG_BOOTP_SEND_HOSTNAME
1926 CONFIG_BOOTP_NTPSERVER
1927 CONFIG_BOOTP_TIMEOFFSET
1928 CONFIG_BOOTP_VENDOREX
1929 CONFIG_BOOTP_MAY_FAIL
1931 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1932 environment variable, not the BOOTP server.
1934 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1935 after the configured retry count, the call will fail
1936 instead of starting over. This can be used to fail over
1937 to Link-local IP address configuration if the DHCP server
1940 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1941 serverip from a DHCP server, it is possible that more
1942 than one DNS serverip is offered to the client.
1943 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1944 serverip will be stored in the additional environment
1945 variable "dnsip2". The first DNS serverip is always
1946 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1949 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1950 to do a dynamic update of a DNS server. To do this, they
1951 need the hostname of the DHCP requester.
1952 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1953 of the "hostname" environment variable is passed as
1954 option 12 to the DHCP server.
1956 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1958 A 32bit value in microseconds for a delay between
1959 receiving a "DHCP Offer" and sending the "DHCP Request".
1960 This fixes a problem with certain DHCP servers that don't
1961 respond 100% of the time to a "DHCP request". E.g. On an
1962 AT91RM9200 processor running at 180MHz, this delay needed
1963 to be *at least* 15,000 usec before a Windows Server 2003
1964 DHCP server would reply 100% of the time. I recommend at
1965 least 50,000 usec to be safe. The alternative is to hope
1966 that one of the retries will be successful but note that
1967 the DHCP timeout and retry process takes a longer than
1970 - Link-local IP address negotiation:
1971 Negotiate with other link-local clients on the local network
1972 for an address that doesn't require explicit configuration.
1973 This is especially useful if a DHCP server cannot be guaranteed
1974 to exist in all environments that the device must operate.
1976 See doc/README.link-local for more information.
1979 CONFIG_CDP_DEVICE_ID
1981 The device id used in CDP trigger frames.
1983 CONFIG_CDP_DEVICE_ID_PREFIX
1985 A two character string which is prefixed to the MAC address
1990 A printf format string which contains the ascii name of
1991 the port. Normally is set to "eth%d" which sets
1992 eth0 for the first Ethernet, eth1 for the second etc.
1994 CONFIG_CDP_CAPABILITIES
1996 A 32bit integer which indicates the device capabilities;
1997 0x00000010 for a normal host which does not forwards.
2001 An ascii string containing the version of the software.
2005 An ascii string containing the name of the platform.
2009 A 32bit integer sent on the trigger.
2011 CONFIG_CDP_POWER_CONSUMPTION
2013 A 16bit integer containing the power consumption of the
2014 device in .1 of milliwatts.
2016 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2018 A byte containing the id of the VLAN.
2020 - Status LED: CONFIG_STATUS_LED
2022 Several configurations allow to display the current
2023 status using a LED. For instance, the LED will blink
2024 fast while running U-Boot code, stop blinking as
2025 soon as a reply to a BOOTP request was received, and
2026 start blinking slow once the Linux kernel is running
2027 (supported by a status LED driver in the Linux
2028 kernel). Defining CONFIG_STATUS_LED enables this
2034 The status LED can be connected to a GPIO pin.
2035 In such cases, the gpio_led driver can be used as a
2036 status LED backend implementation. Define CONFIG_GPIO_LED
2037 to include the gpio_led driver in the U-Boot binary.
2039 CONFIG_GPIO_LED_INVERTED_TABLE
2040 Some GPIO connected LEDs may have inverted polarity in which
2041 case the GPIO high value corresponds to LED off state and
2042 GPIO low value corresponds to LED on state.
2043 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2044 with a list of GPIO LEDs that have inverted polarity.
2046 - CAN Support: CONFIG_CAN_DRIVER
2048 Defining CONFIG_CAN_DRIVER enables CAN driver support
2049 on those systems that support this (optional)
2050 feature, like the TQM8xxL modules.
2052 - I2C Support: CONFIG_SYS_I2C
2054 This enable the NEW i2c subsystem, and will allow you to use
2055 i2c commands at the u-boot command line (as long as you set
2056 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2057 based realtime clock chips or other i2c devices. See
2058 common/cmd_i2c.c for a description of the command line
2061 ported i2c driver to the new framework:
2062 - drivers/i2c/soft_i2c.c:
2063 - activate first bus with CONFIG_SYS_I2C_SOFT define
2064 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2065 for defining speed and slave address
2066 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2067 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2068 for defining speed and slave address
2069 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2070 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2071 for defining speed and slave address
2072 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2073 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2074 for defining speed and slave address
2076 - drivers/i2c/fsl_i2c.c:
2077 - activate i2c driver with CONFIG_SYS_I2C_FSL
2078 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2079 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2080 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2082 - If your board supports a second fsl i2c bus, define
2083 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2084 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2085 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2088 - drivers/i2c/tegra_i2c.c:
2089 - activate this driver with CONFIG_SYS_I2C_TEGRA
2090 - This driver adds 4 i2c buses with a fix speed from
2091 100000 and the slave addr 0!
2093 - drivers/i2c/ppc4xx_i2c.c
2094 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2095 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2096 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2098 - drivers/i2c/i2c_mxc.c
2099 - activate this driver with CONFIG_SYS_I2C_MXC
2100 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2101 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2102 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2103 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2104 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2105 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2106 If thoses defines are not set, default value is 100000
2107 for speed, and 0 for slave.
2109 - drivers/i2c/rcar_i2c.c:
2110 - activate this driver with CONFIG_SYS_I2C_RCAR
2111 - This driver adds 4 i2c buses
2113 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2114 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2115 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2116 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2117 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2118 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2119 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2120 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2121 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2123 - drivers/i2c/sh_i2c.c:
2124 - activate this driver with CONFIG_SYS_I2C_SH
2125 - This driver adds from 2 to 5 i2c buses
2127 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2128 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2129 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2130 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2131 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2132 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2133 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2134 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2135 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2136 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2137 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2138 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2139 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2141 - drivers/i2c/omap24xx_i2c.c
2142 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2143 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2144 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2145 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2146 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2147 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2148 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2149 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2150 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2151 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2152 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2154 - drivers/i2c/zynq_i2c.c
2155 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2156 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2157 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2159 - drivers/i2c/s3c24x0_i2c.c:
2160 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2161 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2162 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2163 with a fix speed from 100000 and the slave addr 0!
2167 CONFIG_SYS_NUM_I2C_BUSES
2168 Hold the number of i2c busses you want to use. If you
2169 don't use/have i2c muxes on your i2c bus, this
2170 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2173 CONFIG_SYS_I2C_DIRECT_BUS
2174 define this, if you don't use i2c muxes on your hardware.
2175 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2178 CONFIG_SYS_I2C_MAX_HOPS
2179 define how many muxes are maximal consecutively connected
2180 on one i2c bus. If you not use i2c muxes, omit this
2183 CONFIG_SYS_I2C_BUSES
2184 hold a list of busses you want to use, only used if
2185 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2186 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2187 CONFIG_SYS_NUM_I2C_BUSES = 9:
2189 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2190 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2191 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2192 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2193 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2194 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2195 {1, {I2C_NULL_HOP}}, \
2196 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2197 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2201 bus 0 on adapter 0 without a mux
2202 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2203 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2204 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2205 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2206 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2207 bus 6 on adapter 1 without a mux
2208 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2209 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2211 If you do not have i2c muxes on your board, omit this define.
2213 - Legacy I2C Support: CONFIG_HARD_I2C
2215 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2216 provides the following compelling advantages:
2218 - more than one i2c adapter is usable
2219 - approved multibus support
2220 - better i2c mux support
2222 ** Please consider updating your I2C driver now. **
2224 These enable legacy I2C serial bus commands. Defining
2225 CONFIG_HARD_I2C will include the appropriate I2C driver
2226 for the selected CPU.
2228 This will allow you to use i2c commands at the u-boot
2229 command line (as long as you set CONFIG_CMD_I2C in
2230 CONFIG_COMMANDS) and communicate with i2c based realtime
2231 clock chips. See common/cmd_i2c.c for a description of the
2232 command line interface.
2234 CONFIG_HARD_I2C selects a hardware I2C controller.
2236 There are several other quantities that must also be
2237 defined when you define CONFIG_HARD_I2C.
2239 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2240 to be the frequency (in Hz) at which you wish your i2c bus
2241 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2242 the CPU's i2c node address).
2244 Now, the u-boot i2c code for the mpc8xx
2245 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2246 and so its address should therefore be cleared to 0 (See,
2247 eg, MPC823e User's Manual p.16-473). So, set
2248 CONFIG_SYS_I2C_SLAVE to 0.
2250 CONFIG_SYS_I2C_INIT_MPC5XXX
2252 When a board is reset during an i2c bus transfer
2253 chips might think that the current transfer is still
2254 in progress. Reset the slave devices by sending start
2255 commands until the slave device responds.
2257 That's all that's required for CONFIG_HARD_I2C.
2259 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2260 then the following macros need to be defined (examples are
2261 from include/configs/lwmon.h):
2265 (Optional). Any commands necessary to enable the I2C
2266 controller or configure ports.
2268 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2272 (Only for MPC8260 CPU). The I/O port to use (the code
2273 assumes both bits are on the same port). Valid values
2274 are 0..3 for ports A..D.
2278 The code necessary to make the I2C data line active
2279 (driven). If the data line is open collector, this
2282 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2286 The code necessary to make the I2C data line tri-stated
2287 (inactive). If the data line is open collector, this
2290 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2294 Code that returns true if the I2C data line is high,
2297 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2301 If <bit> is true, sets the I2C data line high. If it
2302 is false, it clears it (low).
2304 eg: #define I2C_SDA(bit) \
2305 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2306 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2310 If <bit> is true, sets the I2C clock line high. If it
2311 is false, it clears it (low).
2313 eg: #define I2C_SCL(bit) \
2314 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2315 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2319 This delay is invoked four times per clock cycle so this
2320 controls the rate of data transfer. The data rate thus
2321 is 1 / (I2C_DELAY * 4). Often defined to be something
2324 #define I2C_DELAY udelay(2)
2326 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2328 If your arch supports the generic GPIO framework (asm/gpio.h),
2329 then you may alternatively define the two GPIOs that are to be
2330 used as SCL / SDA. Any of the previous I2C_xxx macros will
2331 have GPIO-based defaults assigned to them as appropriate.
2333 You should define these to the GPIO value as given directly to
2334 the generic GPIO functions.
2336 CONFIG_SYS_I2C_INIT_BOARD
2338 When a board is reset during an i2c bus transfer
2339 chips might think that the current transfer is still
2340 in progress. On some boards it is possible to access
2341 the i2c SCLK line directly, either by using the
2342 processor pin as a GPIO or by having a second pin
2343 connected to the bus. If this option is defined a
2344 custom i2c_init_board() routine in boards/xxx/board.c
2345 is run early in the boot sequence.
2347 CONFIG_SYS_I2C_BOARD_LATE_INIT
2349 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2350 defined a custom i2c_board_late_init() routine in
2351 boards/xxx/board.c is run AFTER the operations in i2c_init()
2352 is completed. This callpoint can be used to unreset i2c bus
2353 using CPU i2c controller register accesses for CPUs whose i2c
2354 controller provide such a method. It is called at the end of
2355 i2c_init() to allow i2c_init operations to setup the i2c bus
2356 controller on the CPU (e.g. setting bus speed & slave address).
2358 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2360 This option enables configuration of bi_iic_fast[] flags
2361 in u-boot bd_info structure based on u-boot environment
2362 variable "i2cfast". (see also i2cfast)
2364 CONFIG_I2C_MULTI_BUS
2366 This option allows the use of multiple I2C buses, each of which
2367 must have a controller. At any point in time, only one bus is
2368 active. To switch to a different bus, use the 'i2c dev' command.
2369 Note that bus numbering is zero-based.
2371 CONFIG_SYS_I2C_NOPROBES
2373 This option specifies a list of I2C devices that will be skipped
2374 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2375 is set, specify a list of bus-device pairs. Otherwise, specify
2376 a 1D array of device addresses
2379 #undef CONFIG_I2C_MULTI_BUS
2380 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2382 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2384 #define CONFIG_I2C_MULTI_BUS
2385 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2387 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2389 CONFIG_SYS_SPD_BUS_NUM
2391 If defined, then this indicates the I2C bus number for DDR SPD.
2392 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2394 CONFIG_SYS_RTC_BUS_NUM
2396 If defined, then this indicates the I2C bus number for the RTC.
2397 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2399 CONFIG_SYS_DTT_BUS_NUM
2401 If defined, then this indicates the I2C bus number for the DTT.
2402 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2404 CONFIG_SYS_I2C_DTT_ADDR:
2406 If defined, specifies the I2C address of the DTT device.
2407 If not defined, then U-Boot uses predefined value for
2408 specified DTT device.
2410 CONFIG_SOFT_I2C_READ_REPEATED_START
2412 defining this will force the i2c_read() function in
2413 the soft_i2c driver to perform an I2C repeated start
2414 between writing the address pointer and reading the
2415 data. If this define is omitted the default behaviour
2416 of doing a stop-start sequence will be used. Most I2C
2417 devices can use either method, but some require one or
2420 - SPI Support: CONFIG_SPI
2422 Enables SPI driver (so far only tested with
2423 SPI EEPROM, also an instance works with Crystal A/D and
2424 D/As on the SACSng board)
2428 Enables the driver for SPI controller on SuperH. Currently
2429 only SH7757 is supported.
2433 Enables extended (16-bit) SPI EEPROM addressing.
2434 (symmetrical to CONFIG_I2C_X)
2438 Enables a software (bit-bang) SPI driver rather than
2439 using hardware support. This is a general purpose
2440 driver that only requires three general I/O port pins
2441 (two outputs, one input) to function. If this is
2442 defined, the board configuration must define several
2443 SPI configuration items (port pins to use, etc). For
2444 an example, see include/configs/sacsng.h.
2448 Enables a hardware SPI driver for general-purpose reads
2449 and writes. As with CONFIG_SOFT_SPI, the board configuration
2450 must define a list of chip-select function pointers.
2451 Currently supported on some MPC8xxx processors. For an
2452 example, see include/configs/mpc8349emds.h.
2456 Enables the driver for the SPI controllers on i.MX and MXC
2457 SoCs. Currently i.MX31/35/51 are supported.
2459 - FPGA Support: CONFIG_FPGA
2461 Enables FPGA subsystem.
2463 CONFIG_FPGA_<vendor>
2465 Enables support for specific chip vendors.
2468 CONFIG_FPGA_<family>
2470 Enables support for FPGA family.
2471 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2475 Specify the number of FPGA devices to support.
2477 CONFIG_SYS_FPGA_PROG_FEEDBACK
2479 Enable printing of hash marks during FPGA configuration.
2481 CONFIG_SYS_FPGA_CHECK_BUSY
2483 Enable checks on FPGA configuration interface busy
2484 status by the configuration function. This option
2485 will require a board or device specific function to
2490 If defined, a function that provides delays in the FPGA
2491 configuration driver.
2493 CONFIG_SYS_FPGA_CHECK_CTRLC
2494 Allow Control-C to interrupt FPGA configuration
2496 CONFIG_SYS_FPGA_CHECK_ERROR
2498 Check for configuration errors during FPGA bitfile
2499 loading. For example, abort during Virtex II
2500 configuration if the INIT_B line goes low (which
2501 indicated a CRC error).
2503 CONFIG_SYS_FPGA_WAIT_INIT
2505 Maximum time to wait for the INIT_B line to deassert
2506 after PROB_B has been deasserted during a Virtex II
2507 FPGA configuration sequence. The default time is 500
2510 CONFIG_SYS_FPGA_WAIT_BUSY
2512 Maximum time to wait for BUSY to deassert during
2513 Virtex II FPGA configuration. The default is 5 ms.
2515 CONFIG_SYS_FPGA_WAIT_CONFIG
2517 Time to wait after FPGA configuration. The default is
2520 - Configuration Management:
2523 If defined, this string will be added to the U-Boot
2524 version information (U_BOOT_VERSION)
2526 - Vendor Parameter Protection:
2528 U-Boot considers the values of the environment
2529 variables "serial#" (Board Serial Number) and
2530 "ethaddr" (Ethernet Address) to be parameters that
2531 are set once by the board vendor / manufacturer, and
2532 protects these variables from casual modification by
2533 the user. Once set, these variables are read-only,
2534 and write or delete attempts are rejected. You can
2535 change this behaviour:
2537 If CONFIG_ENV_OVERWRITE is #defined in your config
2538 file, the write protection for vendor parameters is
2539 completely disabled. Anybody can change or delete
2542 Alternatively, if you #define _both_ CONFIG_ETHADDR
2543 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2544 Ethernet address is installed in the environment,
2545 which can be changed exactly ONCE by the user. [The
2546 serial# is unaffected by this, i. e. it remains
2549 The same can be accomplished in a more flexible way
2550 for any variable by configuring the type of access
2551 to allow for those variables in the ".flags" variable
2552 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2557 Define this variable to enable the reservation of
2558 "protected RAM", i. e. RAM which is not overwritten
2559 by U-Boot. Define CONFIG_PRAM to hold the number of
2560 kB you want to reserve for pRAM. You can overwrite
2561 this default value by defining an environment
2562 variable "pram" to the number of kB you want to
2563 reserve. Note that the board info structure will
2564 still show the full amount of RAM. If pRAM is
2565 reserved, a new environment variable "mem" will
2566 automatically be defined to hold the amount of
2567 remaining RAM in a form that can be passed as boot
2568 argument to Linux, for instance like that:
2570 setenv bootargs ... mem=\${mem}
2573 This way you can tell Linux not to use this memory,
2574 either, which results in a memory region that will
2575 not be affected by reboots.
2577 *WARNING* If your board configuration uses automatic
2578 detection of the RAM size, you must make sure that
2579 this memory test is non-destructive. So far, the
2580 following board configurations are known to be
2583 IVMS8, IVML24, SPD8xx, TQM8xxL,
2584 HERMES, IP860, RPXlite, LWMON,
2587 - Access to physical memory region (> 4GB)
2588 Some basic support is provided for operations on memory not
2589 normally accessible to U-Boot - e.g. some architectures
2590 support access to more than 4GB of memory on 32-bit
2591 machines using physical address extension or similar.
2592 Define CONFIG_PHYSMEM to access this basic support, which
2593 currently only supports clearing the memory.
2598 Define this variable to stop the system in case of a
2599 fatal error, so that you have to reset it manually.
2600 This is probably NOT a good idea for an embedded
2601 system where you want the system to reboot
2602 automatically as fast as possible, but it may be
2603 useful during development since you can try to debug
2604 the conditions that lead to the situation.
2606 CONFIG_NET_RETRY_COUNT
2608 This variable defines the number of retries for
2609 network operations like ARP, RARP, TFTP, or BOOTP
2610 before giving up the operation. If not defined, a
2611 default value of 5 is used.
2615 Timeout waiting for an ARP reply in milliseconds.
2619 Timeout in milliseconds used in NFS protocol.
2620 If you encounter "ERROR: Cannot umount" in nfs command,
2621 try longer timeout such as
2622 #define CONFIG_NFS_TIMEOUT 10000UL
2624 - Command Interpreter:
2625 CONFIG_AUTO_COMPLETE
2627 Enable auto completion of commands using TAB.
2629 Note that this feature has NOT been implemented yet
2630 for the "hush" shell.
2633 CONFIG_SYS_HUSH_PARSER
2635 Define this variable to enable the "hush" shell (from
2636 Busybox) as command line interpreter, thus enabling
2637 powerful command line syntax like
2638 if...then...else...fi conditionals or `&&' and '||'
2639 constructs ("shell scripts").
2641 If undefined, you get the old, much simpler behaviour
2642 with a somewhat smaller memory footprint.
2645 CONFIG_SYS_PROMPT_HUSH_PS2
2647 This defines the secondary prompt string, which is
2648 printed when the command interpreter needs more input
2649 to complete a command. Usually "> ".
2653 In the current implementation, the local variables
2654 space and global environment variables space are
2655 separated. Local variables are those you define by
2656 simply typing `name=value'. To access a local
2657 variable later on, you have write `$name' or
2658 `${name}'; to execute the contents of a variable
2659 directly type `$name' at the command prompt.
2661 Global environment variables are those you use
2662 setenv/printenv to work with. To run a command stored
2663 in such a variable, you need to use the run command,
2664 and you must not use the '$' sign to access them.
2666 To store commands and special characters in a
2667 variable, please use double quotation marks
2668 surrounding the whole text of the variable, instead
2669 of the backslashes before semicolons and special
2672 - Commandline Editing and History:
2673 CONFIG_CMDLINE_EDITING
2675 Enable editing and History functions for interactive
2676 commandline input operations
2678 - Default Environment:
2679 CONFIG_EXTRA_ENV_SETTINGS
2681 Define this to contain any number of null terminated
2682 strings (variable = value pairs) that will be part of
2683 the default environment compiled into the boot image.
2685 For example, place something like this in your
2686 board's config file:
2688 #define CONFIG_EXTRA_ENV_SETTINGS \
2692 Warning: This method is based on knowledge about the
2693 internal format how the environment is stored by the
2694 U-Boot code. This is NOT an official, exported
2695 interface! Although it is unlikely that this format
2696 will change soon, there is no guarantee either.
2697 You better know what you are doing here.
2699 Note: overly (ab)use of the default environment is
2700 discouraged. Make sure to check other ways to preset
2701 the environment like the "source" command or the
2704 CONFIG_ENV_VARS_UBOOT_CONFIG
2706 Define this in order to add variables describing the
2707 U-Boot build configuration to the default environment.
2708 These will be named arch, cpu, board, vendor, and soc.
2710 Enabling this option will cause the following to be defined:
2718 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2720 Define this in order to add variables describing certain
2721 run-time determined information about the hardware to the
2722 environment. These will be named board_name, board_rev.
2724 CONFIG_DELAY_ENVIRONMENT
2726 Normally the environment is loaded when the board is
2727 intialised so that it is available to U-Boot. This inhibits
2728 that so that the environment is not available until
2729 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2730 this is instead controlled by the value of
2731 /config/load-environment.
2733 - DataFlash Support:
2734 CONFIG_HAS_DATAFLASH
2736 Defining this option enables DataFlash features and
2737 allows to read/write in Dataflash via the standard
2740 - Serial Flash support
2743 Defining this option enables SPI flash commands
2744 'sf probe/read/write/erase/update'.
2746 Usage requires an initial 'probe' to define the serial
2747 flash parameters, followed by read/write/erase/update
2750 The following defaults may be provided by the platform
2751 to handle the common case when only a single serial
2752 flash is present on the system.
2754 CONFIG_SF_DEFAULT_BUS Bus identifier
2755 CONFIG_SF_DEFAULT_CS Chip-select
2756 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2757 CONFIG_SF_DEFAULT_SPEED in Hz
2761 Define this option to include a destructive SPI flash
2764 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2766 Define this option to use the Bank addr/Extended addr
2767 support on SPI flashes which has size > 16Mbytes.
2769 CONFIG_SF_DUAL_FLASH Dual flash memories
2771 Define this option to use dual flash support where two flash
2772 memories can be connected with a given cs line.
2773 currently Xilinx Zynq qspi support these type of connections.
2775 - SystemACE Support:
2778 Adding this option adds support for Xilinx SystemACE
2779 chips attached via some sort of local bus. The address
2780 of the chip must also be defined in the
2781 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2783 #define CONFIG_SYSTEMACE
2784 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2786 When SystemACE support is added, the "ace" device type
2787 becomes available to the fat commands, i.e. fatls.
2789 - TFTP Fixed UDP Port:
2792 If this is defined, the environment variable tftpsrcp
2793 is used to supply the TFTP UDP source port value.
2794 If tftpsrcp isn't defined, the normal pseudo-random port
2795 number generator is used.
2797 Also, the environment variable tftpdstp is used to supply
2798 the TFTP UDP destination port value. If tftpdstp isn't
2799 defined, the normal port 69 is used.
2801 The purpose for tftpsrcp is to allow a TFTP server to
2802 blindly start the TFTP transfer using the pre-configured
2803 target IP address and UDP port. This has the effect of
2804 "punching through" the (Windows XP) firewall, allowing
2805 the remainder of the TFTP transfer to proceed normally.
2806 A better solution is to properly configure the firewall,
2807 but sometimes that is not allowed.
2812 This enables a generic 'hash' command which can produce
2813 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2817 Enable the hash verify command (hash -v). This adds to code
2820 CONFIG_SHA1 - support SHA1 hashing
2821 CONFIG_SHA256 - support SHA256 hashing
2823 Note: There is also a sha1sum command, which should perhaps
2824 be deprecated in favour of 'hash sha1'.
2826 - Freescale i.MX specific commands:
2827 CONFIG_CMD_HDMIDETECT
2828 This enables 'hdmidet' command which returns true if an
2829 HDMI monitor is detected. This command is i.MX 6 specific.
2832 This enables the 'bmode' (bootmode) command for forcing
2833 a boot from specific media.
2835 This is useful for forcing the ROM's usb downloader to
2836 activate upon a watchdog reset which is nice when iterating
2837 on U-Boot. Using the reset button or running bmode normal
2838 will set it back to normal. This command currently
2839 supports i.MX53 and i.MX6.
2844 This enables the RSA algorithm used for FIT image verification
2845 in U-Boot. See doc/uImage/signature for more information.
2847 The signing part is build into mkimage regardless of this
2851 - Show boot progress:
2852 CONFIG_SHOW_BOOT_PROGRESS
2854 Defining this option allows to add some board-
2855 specific code (calling a user-provided function
2856 "show_boot_progress(int)") that enables you to show
2857 the system's boot progress on some display (for
2858 example, some LED's) on your board. At the moment,
2859 the following checkpoints are implemented:
2861 - Detailed boot stage timing
2863 Define this option to get detailed timing of each stage
2864 of the boot process.
2866 CONFIG_BOOTSTAGE_USER_COUNT
2867 This is the number of available user bootstage records.
2868 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2869 a new ID will be allocated from this stash. If you exceed
2870 the limit, recording will stop.
2872 CONFIG_BOOTSTAGE_REPORT
2873 Define this to print a report before boot, similar to this:
2875 Timer summary in microseconds:
2878 3,575,678 3,575,678 board_init_f start
2879 3,575,695 17 arch_cpu_init A9
2880 3,575,777 82 arch_cpu_init done
2881 3,659,598 83,821 board_init_r start
2882 3,910,375 250,777 main_loop
2883 29,916,167 26,005,792 bootm_start
2884 30,361,327 445,160 start_kernel
2886 CONFIG_CMD_BOOTSTAGE
2887 Add a 'bootstage' command which supports printing a report
2888 and un/stashing of bootstage data.
2890 CONFIG_BOOTSTAGE_FDT
2891 Stash the bootstage information in the FDT. A root 'bootstage'
2892 node is created with each bootstage id as a child. Each child
2893 has a 'name' property and either 'mark' containing the
2894 mark time in microsecond, or 'accum' containing the
2895 accumulated time for that bootstage id in microseconds.
2900 name = "board_init_f";
2909 Code in the Linux kernel can find this in /proc/devicetree.
2911 Legacy uImage format:
2914 1 common/cmd_bootm.c before attempting to boot an image
2915 -1 common/cmd_bootm.c Image header has bad magic number
2916 2 common/cmd_bootm.c Image header has correct magic number
2917 -2 common/cmd_bootm.c Image header has bad checksum
2918 3 common/cmd_bootm.c Image header has correct checksum
2919 -3 common/cmd_bootm.c Image data has bad checksum
2920 4 common/cmd_bootm.c Image data has correct checksum
2921 -4 common/cmd_bootm.c Image is for unsupported architecture
2922 5 common/cmd_bootm.c Architecture check OK
2923 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2924 6 common/cmd_bootm.c Image Type check OK
2925 -6 common/cmd_bootm.c gunzip uncompression error
2926 -7 common/cmd_bootm.c Unimplemented compression type
2927 7 common/cmd_bootm.c Uncompression OK
2928 8 common/cmd_bootm.c No uncompress/copy overwrite error
2929 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2931 9 common/image.c Start initial ramdisk verification
2932 -10 common/image.c Ramdisk header has bad magic number
2933 -11 common/image.c Ramdisk header has bad checksum
2934 10 common/image.c Ramdisk header is OK
2935 -12 common/image.c Ramdisk data has bad checksum
2936 11 common/image.c Ramdisk data has correct checksum
2937 12 common/image.c Ramdisk verification complete, start loading
2938 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2939 13 common/image.c Start multifile image verification
2940 14 common/image.c No initial ramdisk, no multifile, continue.
2942 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2944 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2945 -31 post/post.c POST test failed, detected by post_output_backlog()
2946 -32 post/post.c POST test failed, detected by post_run_single()
2948 34 common/cmd_doc.c before loading a Image from a DOC device
2949 -35 common/cmd_doc.c Bad usage of "doc" command
2950 35 common/cmd_doc.c correct usage of "doc" command
2951 -36 common/cmd_doc.c No boot device
2952 36 common/cmd_doc.c correct boot device
2953 -37 common/cmd_doc.c Unknown Chip ID on boot device
2954 37 common/cmd_doc.c correct chip ID found, device available
2955 -38 common/cmd_doc.c Read Error on boot device
2956 38 common/cmd_doc.c reading Image header from DOC device OK
2957 -39 common/cmd_doc.c Image header has bad magic number
2958 39 common/cmd_doc.c Image header has correct magic number
2959 -40 common/cmd_doc.c Error reading Image from DOC device
2960 40 common/cmd_doc.c Image header has correct magic number
2961 41 common/cmd_ide.c before loading a Image from a IDE device
2962 -42 common/cmd_ide.c Bad usage of "ide" command
2963 42 common/cmd_ide.c correct usage of "ide" command
2964 -43 common/cmd_ide.c No boot device
2965 43 common/cmd_ide.c boot device found
2966 -44 common/cmd_ide.c Device not available
2967 44 common/cmd_ide.c Device available
2968 -45 common/cmd_ide.c wrong partition selected
2969 45 common/cmd_ide.c partition selected
2970 -46 common/cmd_ide.c Unknown partition table
2971 46 common/cmd_ide.c valid partition table found
2972 -47 common/cmd_ide.c Invalid partition type
2973 47 common/cmd_ide.c correct partition type
2974 -48 common/cmd_ide.c Error reading Image Header on boot device
2975 48 common/cmd_ide.c reading Image Header from IDE device OK
2976 -49 common/cmd_ide.c Image header has bad magic number
2977 49 common/cmd_ide.c Image header has correct magic number
2978 -50 common/cmd_ide.c Image header has bad checksum
2979 50 common/cmd_ide.c Image header has correct checksum
2980 -51 common/cmd_ide.c Error reading Image from IDE device
2981 51 common/cmd_ide.c reading Image from IDE device OK
2982 52 common/cmd_nand.c before loading a Image from a NAND device
2983 -53 common/cmd_nand.c Bad usage of "nand" command
2984 53 common/cmd_nand.c correct usage of "nand" command
2985 -54 common/cmd_nand.c No boot device
2986 54 common/cmd_nand.c boot device found
2987 -55 common/cmd_nand.c Unknown Chip ID on boot device
2988 55 common/cmd_nand.c correct chip ID found, device available
2989 -56 common/cmd_nand.c Error reading Image Header on boot device
2990 56 common/cmd_nand.c reading Image Header from NAND device OK
2991 -57 common/cmd_nand.c Image header has bad magic number
2992 57 common/cmd_nand.c Image header has correct magic number
2993 -58 common/cmd_nand.c Error reading Image from NAND device
2994 58 common/cmd_nand.c reading Image from NAND device OK
2996 -60 common/env_common.c Environment has a bad CRC, using default
2998 64 net/eth.c starting with Ethernet configuration.
2999 -64 net/eth.c no Ethernet found.
3000 65 net/eth.c Ethernet found.
3002 -80 common/cmd_net.c usage wrong
3003 80 common/cmd_net.c before calling NetLoop()
3004 -81 common/cmd_net.c some error in NetLoop() occurred
3005 81 common/cmd_net.c NetLoop() back without error
3006 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3007 82 common/cmd_net.c trying automatic boot
3008 83 common/cmd_net.c running "source" command
3009 -83 common/cmd_net.c some error in automatic boot or "source" command
3010 84 common/cmd_net.c end without errors
3015 100 common/cmd_bootm.c Kernel FIT Image has correct format
3016 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3017 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3018 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3019 102 common/cmd_bootm.c Kernel unit name specified
3020 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3021 103 common/cmd_bootm.c Found configuration node
3022 104 common/cmd_bootm.c Got kernel subimage node offset
3023 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3024 105 common/cmd_bootm.c Kernel subimage hash verification OK
3025 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3026 106 common/cmd_bootm.c Architecture check OK
3027 -106 common/cmd_bootm.c Kernel subimage has wrong type
3028 107 common/cmd_bootm.c Kernel subimage type OK
3029 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3030 108 common/cmd_bootm.c Got kernel subimage data/size
3031 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3032 -109 common/cmd_bootm.c Can't get kernel subimage type
3033 -110 common/cmd_bootm.c Can't get kernel subimage comp
3034 -111 common/cmd_bootm.c Can't get kernel subimage os
3035 -112 common/cmd_bootm.c Can't get kernel subimage load address
3036 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3038 120 common/image.c Start initial ramdisk verification
3039 -120 common/image.c Ramdisk FIT image has incorrect format
3040 121 common/image.c Ramdisk FIT image has correct format
3041 122 common/image.c No ramdisk subimage unit name, using configuration
3042 -122 common/image.c Can't get configuration for ramdisk subimage
3043 123 common/image.c Ramdisk unit name specified
3044 -124 common/image.c Can't get ramdisk subimage node offset
3045 125 common/image.c Got ramdisk subimage node offset
3046 -125 common/image.c Ramdisk subimage hash verification failed
3047 126 common/image.c Ramdisk subimage hash verification OK
3048 -126 common/image.c Ramdisk subimage for unsupported architecture
3049 127 common/image.c Architecture check OK
3050 -127 common/image.c Can't get ramdisk subimage data/size
3051 128 common/image.c Got ramdisk subimage data/size
3052 129 common/image.c Can't get ramdisk load address
3053 -129 common/image.c Got ramdisk load address
3055 -130 common/cmd_doc.c Incorrect FIT image format
3056 131 common/cmd_doc.c FIT image format OK
3058 -140 common/cmd_ide.c Incorrect FIT image format
3059 141 common/cmd_ide.c FIT image format OK
3061 -150 common/cmd_nand.c Incorrect FIT image format
3062 151 common/cmd_nand.c FIT image format OK
3064 - FIT image support:
3066 Enable support for the FIT uImage format.
3068 CONFIG_FIT_BEST_MATCH
3069 When no configuration is explicitly selected, default to the
3070 one whose fdt's compatibility field best matches that of
3071 U-Boot itself. A match is considered "best" if it matches the
3072 most specific compatibility entry of U-Boot's fdt's root node.
3073 The order of entries in the configuration's fdt is ignored.
3075 CONFIG_FIT_SIGNATURE
3076 This option enables signature verification of FIT uImages,
3077 using a hash signed and verified using RSA. See
3078 doc/uImage.FIT/signature.txt for more details.
3080 - Standalone program support:
3081 CONFIG_STANDALONE_LOAD_ADDR
3083 This option defines a board specific value for the
3084 address where standalone program gets loaded, thus
3085 overwriting the architecture dependent default
3088 - Frame Buffer Address:
3091 Define CONFIG_FB_ADDR if you want to use specific
3092 address for frame buffer. This is typically the case
3093 when using a graphics controller has separate video
3094 memory. U-Boot will then place the frame buffer at
3095 the given address instead of dynamically reserving it
3096 in system RAM by calling lcd_setmem(), which grabs
3097 the memory for the frame buffer depending on the
3098 configured panel size.
3100 Please see board_init_f function.
3102 - Automatic software updates via TFTP server
3104 CONFIG_UPDATE_TFTP_CNT_MAX
3105 CONFIG_UPDATE_TFTP_MSEC_MAX
3107 These options enable and control the auto-update feature;
3108 for a more detailed description refer to doc/README.update.
3110 - MTD Support (mtdparts command, UBI support)
3113 Adds the MTD device infrastructure from the Linux kernel.
3114 Needed for mtdparts command support.
3116 CONFIG_MTD_PARTITIONS
3118 Adds the MTD partitioning infrastructure from the Linux
3119 kernel. Needed for UBI support.
3124 Adds commands for interacting with MTD partitions formatted
3125 with the UBI flash translation layer
3127 Requires also defining CONFIG_RBTREE
3129 CONFIG_UBI_SILENCE_MSG
3131 Make the verbose messages from UBI stop printing. This leaves
3132 warnings and errors enabled.
3137 Adds commands for interacting with UBI volumes formatted as
3138 UBIFS. UBIFS is read-only in u-boot.
3140 Requires UBI support as well as CONFIG_LZO
3142 CONFIG_UBIFS_SILENCE_MSG
3144 Make the verbose messages from UBIFS stop printing. This leaves
3145 warnings and errors enabled.
3149 Enable building of SPL globally.
3152 LDSCRIPT for linking the SPL binary.
3154 CONFIG_SPL_MAX_FOOTPRINT
3155 Maximum size in memory allocated to the SPL, BSS included.
3156 When defined, the linker checks that the actual memory
3157 used by SPL from _start to __bss_end does not exceed it.
3158 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3159 must not be both defined at the same time.
3162 Maximum size of the SPL image (text, data, rodata, and
3163 linker lists sections), BSS excluded.
3164 When defined, the linker checks that the actual size does
3167 CONFIG_SPL_TEXT_BASE
3168 TEXT_BASE for linking the SPL binary.
3170 CONFIG_SPL_RELOC_TEXT_BASE
3171 Address to relocate to. If unspecified, this is equal to
3172 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3174 CONFIG_SPL_BSS_START_ADDR
3175 Link address for the BSS within the SPL binary.
3177 CONFIG_SPL_BSS_MAX_SIZE
3178 Maximum size in memory allocated to the SPL BSS.
3179 When defined, the linker checks that the actual memory used
3180 by SPL from __bss_start to __bss_end does not exceed it.
3181 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3182 must not be both defined at the same time.
3185 Adress of the start of the stack SPL will use
3187 CONFIG_SPL_RELOC_STACK
3188 Adress of the start of the stack SPL will use after
3189 relocation. If unspecified, this is equal to
3192 CONFIG_SYS_SPL_MALLOC_START
3193 Starting address of the malloc pool used in SPL.
3195 CONFIG_SYS_SPL_MALLOC_SIZE
3196 The size of the malloc pool used in SPL.
3198 CONFIG_SPL_FRAMEWORK
3199 Enable the SPL framework under common/. This framework
3200 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3201 NAND loading of the Linux Kernel.
3203 CONFIG_SPL_DISPLAY_PRINT
3204 For ARM, enable an optional function to print more information
3205 about the running system.
3207 CONFIG_SPL_INIT_MINIMAL
3208 Arch init code should be built for a very small image
3210 CONFIG_SPL_LIBCOMMON_SUPPORT
3211 Support for common/libcommon.o in SPL binary
3213 CONFIG_SPL_LIBDISK_SUPPORT
3214 Support for disk/libdisk.o in SPL binary
3216 CONFIG_SPL_I2C_SUPPORT
3217 Support for drivers/i2c/libi2c.o in SPL binary
3219 CONFIG_SPL_GPIO_SUPPORT
3220 Support for drivers/gpio/libgpio.o in SPL binary
3222 CONFIG_SPL_MMC_SUPPORT
3223 Support for drivers/mmc/libmmc.o in SPL binary
3225 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3226 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3227 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3228 Address, size and partition on the MMC to load U-Boot from
3229 when the MMC is being used in raw mode.
3231 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3232 Sector to load kernel uImage from when MMC is being
3233 used in raw mode (for Falcon mode)
3235 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3236 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3237 Sector and number of sectors to load kernel argument
3238 parameters from when MMC is being used in raw mode
3241 CONFIG_SPL_FAT_SUPPORT
3242 Support for fs/fat/libfat.o in SPL binary
3244 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3245 Filename to read to load U-Boot when reading from FAT
3247 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3248 Filename to read to load kernel uImage when reading
3249 from FAT (for Falcon mode)
3251 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3252 Filename to read to load kernel argument parameters
3253 when reading from FAT (for Falcon mode)
3255 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3256 Set this for NAND SPL on PPC mpc83xx targets, so that
3257 start.S waits for the rest of the SPL to load before
3258 continuing (the hardware starts execution after just
3259 loading the first page rather than the full 4K).
3261 CONFIG_SPL_NAND_BASE
3262 Include nand_base.c in the SPL. Requires
3263 CONFIG_SPL_NAND_DRIVERS.
3265 CONFIG_SPL_NAND_DRIVERS
3266 SPL uses normal NAND drivers, not minimal drivers.
3269 Include standard software ECC in the SPL
3271 CONFIG_SPL_NAND_SIMPLE
3272 Support for NAND boot using simple NAND drivers that
3273 expose the cmd_ctrl() interface.
3275 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3276 Set for the SPL on PPC mpc8xxx targets, support for
3277 drivers/ddr/fsl/libddr.o in SPL binary.
3279 CONFIG_SPL_COMMON_INIT_DDR
3280 Set for common ddr init with serial presence detect in
3283 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3284 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3285 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3286 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3287 CONFIG_SYS_NAND_ECCBYTES
3288 Defines the size and behavior of the NAND that SPL uses
3291 CONFIG_SPL_NAND_BOOT
3292 Add support NAND boot
3294 CONFIG_SYS_NAND_U_BOOT_OFFS
3295 Location in NAND to read U-Boot from
3297 CONFIG_SYS_NAND_U_BOOT_DST
3298 Location in memory to load U-Boot to
3300 CONFIG_SYS_NAND_U_BOOT_SIZE
3301 Size of image to load
3303 CONFIG_SYS_NAND_U_BOOT_START
3304 Entry point in loaded image to jump to
3306 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3307 Define this if you need to first read the OOB and then the
3308 data. This is used for example on davinci plattforms.
3310 CONFIG_SPL_OMAP3_ID_NAND
3311 Support for an OMAP3-specific set of functions to return the
3312 ID and MFR of the first attached NAND chip, if present.
3314 CONFIG_SPL_SERIAL_SUPPORT
3315 Support for drivers/serial/libserial.o in SPL binary
3317 CONFIG_SPL_SPI_FLASH_SUPPORT
3318 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3320 CONFIG_SPL_SPI_SUPPORT
3321 Support for drivers/spi/libspi.o in SPL binary
3323 CONFIG_SPL_RAM_DEVICE
3324 Support for running image already present in ram, in SPL binary
3326 CONFIG_SPL_LIBGENERIC_SUPPORT
3327 Support for lib/libgeneric.o in SPL binary
3329 CONFIG_SPL_ENV_SUPPORT
3330 Support for the environment operating in SPL binary
3332 CONFIG_SPL_NET_SUPPORT
3333 Support for the net/libnet.o in SPL binary.
3334 It conflicts with SPL env from storage medium specified by
3335 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3338 Image offset to which the SPL should be padded before appending
3339 the SPL payload. By default, this is defined as
3340 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3341 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3342 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3345 Final target image containing SPL and payload. Some SPLs
3346 use an arch-specific makefile fragment instead, for
3347 example if more than one image needs to be produced.
3349 CONFIG_FIT_SPL_PRINT
3350 Printing information about a FIT image adds quite a bit of
3351 code to SPL. So this is normally disabled in SPL. Use this
3352 option to re-enable it. This will affect the output of the
3353 bootm command when booting a FIT image.
3357 Enable building of TPL globally.
3360 Image offset to which the TPL should be padded before appending
3361 the TPL payload. By default, this is defined as
3362 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3363 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3364 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3369 [so far only for SMDK2400 boards]
3371 - Modem support enable:
3372 CONFIG_MODEM_SUPPORT
3374 - RTS/CTS Flow control enable:
3377 - Modem debug support:
3378 CONFIG_MODEM_SUPPORT_DEBUG
3380 Enables debugging stuff (char screen[1024], dbg())
3381 for modem support. Useful only with BDI2000.
3383 - Interrupt support (PPC):
3385 There are common interrupt_init() and timer_interrupt()
3386 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3387 for CPU specific initialization. interrupt_init_cpu()
3388 should set decrementer_count to appropriate value. If
3389 CPU resets decrementer automatically after interrupt
3390 (ppc4xx) it should set decrementer_count to zero.
3391 timer_interrupt() calls timer_interrupt_cpu() for CPU
3392 specific handling. If board has watchdog / status_led
3393 / other_activity_monitor it works automatically from
3394 general timer_interrupt().
3398 In the target system modem support is enabled when a
3399 specific key (key combination) is pressed during
3400 power-on. Otherwise U-Boot will boot normally
3401 (autoboot). The key_pressed() function is called from
3402 board_init(). Currently key_pressed() is a dummy
3403 function, returning 1 and thus enabling modem
3406 If there are no modem init strings in the
3407 environment, U-Boot proceed to autoboot; the
3408 previous output (banner, info printfs) will be
3411 See also: doc/README.Modem
3413 Board initialization settings:
3414 ------------------------------
3416 During Initialization u-boot calls a number of board specific functions
3417 to allow the preparation of board specific prerequisites, e.g. pin setup
3418 before drivers are initialized. To enable these callbacks the
3419 following configuration macros have to be defined. Currently this is
3420 architecture specific, so please check arch/your_architecture/lib/board.c
3421 typically in board_init_f() and board_init_r().
3423 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3424 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3425 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3426 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3428 Configuration Settings:
3429 -----------------------
3431 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3432 undefine this when you're short of memory.
3434 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3435 width of the commands listed in the 'help' command output.
3437 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3438 prompt for user input.
3440 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3442 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3444 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3446 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3447 the application (usually a Linux kernel) when it is
3450 - CONFIG_SYS_BAUDRATE_TABLE:
3451 List of legal baudrate settings for this board.
3453 - CONFIG_SYS_CONSOLE_INFO_QUIET
3454 Suppress display of console information at boot.
3456 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3457 If the board specific function
3458 extern int overwrite_console (void);
3459 returns 1, the stdin, stderr and stdout are switched to the
3460 serial port, else the settings in the environment are used.
3462 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3463 Enable the call to overwrite_console().
3465 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3466 Enable overwrite of previous console environment settings.
3468 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3469 Begin and End addresses of the area used by the
3472 - CONFIG_SYS_ALT_MEMTEST:
3473 Enable an alternate, more extensive memory test.
3475 - CONFIG_SYS_MEMTEST_SCRATCH:
3476 Scratch address used by the alternate memory test
3477 You only need to set this if address zero isn't writeable
3479 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3480 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3481 this specified memory area will get subtracted from the top
3482 (end) of RAM and won't get "touched" at all by U-Boot. By
3483 fixing up gd->ram_size the Linux kernel should gets passed
3484 the now "corrected" memory size and won't touch it either.
3485 This should work for arch/ppc and arch/powerpc. Only Linux
3486 board ports in arch/powerpc with bootwrapper support that
3487 recalculate the memory size from the SDRAM controller setup
3488 will have to get fixed in Linux additionally.
3490 This option can be used as a workaround for the 440EPx/GRx
3491 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3494 WARNING: Please make sure that this value is a multiple of
3495 the Linux page size (normally 4k). If this is not the case,
3496 then the end address of the Linux memory will be located at a
3497 non page size aligned address and this could cause major
3500 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3501 Enable temporary baudrate change while serial download
3503 - CONFIG_SYS_SDRAM_BASE:
3504 Physical start address of SDRAM. _Must_ be 0 here.
3506 - CONFIG_SYS_MBIO_BASE:
3507 Physical start address of Motherboard I/O (if using a
3510 - CONFIG_SYS_FLASH_BASE:
3511 Physical start address of Flash memory.
3513 - CONFIG_SYS_MONITOR_BASE:
3514 Physical start address of boot monitor code (set by
3515 make config files to be same as the text base address
3516 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3517 CONFIG_SYS_FLASH_BASE when booting from flash.
3519 - CONFIG_SYS_MONITOR_LEN:
3520 Size of memory reserved for monitor code, used to
3521 determine _at_compile_time_ (!) if the environment is
3522 embedded within the U-Boot image, or in a separate
3525 - CONFIG_SYS_MALLOC_LEN:
3526 Size of DRAM reserved for malloc() use.
3528 - CONFIG_SYS_BOOTM_LEN:
3529 Normally compressed uImages are limited to an
3530 uncompressed size of 8 MBytes. If this is not enough,
3531 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3532 to adjust this setting to your needs.
3534 - CONFIG_SYS_BOOTMAPSZ:
3535 Maximum size of memory mapped by the startup code of
3536 the Linux kernel; all data that must be processed by
3537 the Linux kernel (bd_info, boot arguments, FDT blob if
3538 used) must be put below this limit, unless "bootm_low"
3539 environment variable is defined and non-zero. In such case
3540 all data for the Linux kernel must be between "bootm_low"
3541 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3542 variable "bootm_mapsize" will override the value of
3543 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3544 then the value in "bootm_size" will be used instead.
3546 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3547 Enable initrd_high functionality. If defined then the
3548 initrd_high feature is enabled and the bootm ramdisk subcommand
3551 - CONFIG_SYS_BOOT_GET_CMDLINE:
3552 Enables allocating and saving kernel cmdline in space between
3553 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3555 - CONFIG_SYS_BOOT_GET_KBD:
3556 Enables allocating and saving a kernel copy of the bd_info in
3557 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3559 - CONFIG_SYS_MAX_FLASH_BANKS:
3560 Max number of Flash memory banks
3562 - CONFIG_SYS_MAX_FLASH_SECT:
3563 Max number of sectors on a Flash chip
3565 - CONFIG_SYS_FLASH_ERASE_TOUT:
3566 Timeout for Flash erase operations (in ms)
3568 - CONFIG_SYS_FLASH_WRITE_TOUT:
3569 Timeout for Flash write operations (in ms)
3571 - CONFIG_SYS_FLASH_LOCK_TOUT
3572 Timeout for Flash set sector lock bit operation (in ms)
3574 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3575 Timeout for Flash clear lock bits operation (in ms)
3577 - CONFIG_SYS_FLASH_PROTECTION
3578 If defined, hardware flash sectors protection is used
3579 instead of U-Boot software protection.
3581 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3583 Enable TFTP transfers directly to flash memory;
3584 without this option such a download has to be
3585 performed in two steps: (1) download to RAM, and (2)
3586 copy from RAM to flash.
3588 The two-step approach is usually more reliable, since
3589 you can check if the download worked before you erase
3590 the flash, but in some situations (when system RAM is
3591 too limited to allow for a temporary copy of the
3592 downloaded image) this option may be very useful.
3594 - CONFIG_SYS_FLASH_CFI:
3595 Define if the flash driver uses extra elements in the
3596 common flash structure for storing flash geometry.
3598 - CONFIG_FLASH_CFI_DRIVER
3599 This option also enables the building of the cfi_flash driver
3600 in the drivers directory
3602 - CONFIG_FLASH_CFI_MTD
3603 This option enables the building of the cfi_mtd driver
3604 in the drivers directory. The driver exports CFI flash
3607 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3608 Use buffered writes to flash.
3610 - CONFIG_FLASH_SPANSION_S29WS_N
3611 s29ws-n MirrorBit flash has non-standard addresses for buffered
3614 - CONFIG_SYS_FLASH_QUIET_TEST
3615 If this option is defined, the common CFI flash doesn't
3616 print it's warning upon not recognized FLASH banks. This
3617 is useful, if some of the configured banks are only
3618 optionally available.
3620 - CONFIG_FLASH_SHOW_PROGRESS
3621 If defined (must be an integer), print out countdown
3622 digits and dots. Recommended value: 45 (9..1) for 80
3623 column displays, 15 (3..1) for 40 column displays.
3625 - CONFIG_FLASH_VERIFY
3626 If defined, the content of the flash (destination) is compared
3627 against the source after the write operation. An error message
3628 will be printed when the contents are not identical.
3629 Please note that this option is useless in nearly all cases,
3630 since such flash programming errors usually are detected earlier
3631 while unprotecting/erasing/programming. Please only enable
3632 this option if you really know what you are doing.
3634 - CONFIG_SYS_RX_ETH_BUFFER:
3635 Defines the number of Ethernet receive buffers. On some
3636 Ethernet controllers it is recommended to set this value
3637 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3638 buffers can be full shortly after enabling the interface
3639 on high Ethernet traffic.
3640 Defaults to 4 if not defined.
3642 - CONFIG_ENV_MAX_ENTRIES
3644 Maximum number of entries in the hash table that is used
3645 internally to store the environment settings. The default
3646 setting is supposed to be generous and should work in most
3647 cases. This setting can be used to tune behaviour; see
3648 lib/hashtable.c for details.
3650 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3651 - CONFIG_ENV_FLAGS_LIST_STATIC
3652 Enable validation of the values given to environment variables when
3653 calling env set. Variables can be restricted to only decimal,
3654 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3655 the variables can also be restricted to IP address or MAC address.
3657 The format of the list is:
3658 type_attribute = [s|d|x|b|i|m]
3659 access_atribute = [a|r|o|c]
3660 attributes = type_attribute[access_atribute]
3661 entry = variable_name[:attributes]
3664 The type attributes are:
3665 s - String (default)
3668 b - Boolean ([1yYtT|0nNfF])
3672 The access attributes are:
3678 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3679 Define this to a list (string) to define the ".flags"
3680 envirnoment variable in the default or embedded environment.
3682 - CONFIG_ENV_FLAGS_LIST_STATIC
3683 Define this to a list (string) to define validation that
3684 should be done if an entry is not found in the ".flags"
3685 environment variable. To override a setting in the static
3686 list, simply add an entry for the same variable name to the
3689 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3690 If defined, don't allow the -f switch to env set override variable
3693 - CONFIG_SYS_GENERIC_BOARD
3694 This selects the architecture-generic board system instead of the
3695 architecture-specific board files. It is intended to move boards
3696 to this new framework over time. Defining this will disable the
3697 arch/foo/lib/board.c file and use common/board_f.c and
3698 common/board_r.c instead. To use this option your architecture
3699 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3700 its config.mk file). If you find problems enabling this option on
3701 your board please report the problem and send patches!
3703 - CONFIG_SYS_SYM_OFFSETS
3704 This is set by architectures that use offsets for link symbols
3705 instead of absolute values. So bss_start is obtained using an
3706 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3707 directly. You should not need to touch this setting.
3709 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3710 This is set by OMAP boards for the max time that reset should
3711 be asserted. See doc/README.omap-reset-time for details on how
3712 the value can be calulated on a given board.
3714 The following definitions that deal with the placement and management
3715 of environment data (variable area); in general, we support the
3716 following configurations:
3718 - CONFIG_BUILD_ENVCRC:
3720 Builds up envcrc with the target environment so that external utils
3721 may easily extract it and embed it in final U-Boot images.
3723 - CONFIG_ENV_IS_IN_FLASH:
3725 Define this if the environment is in flash memory.
3727 a) The environment occupies one whole flash sector, which is
3728 "embedded" in the text segment with the U-Boot code. This
3729 happens usually with "bottom boot sector" or "top boot
3730 sector" type flash chips, which have several smaller
3731 sectors at the start or the end. For instance, such a
3732 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3733 such a case you would place the environment in one of the
3734 4 kB sectors - with U-Boot code before and after it. With
3735 "top boot sector" type flash chips, you would put the
3736 environment in one of the last sectors, leaving a gap
3737 between U-Boot and the environment.
3739 - CONFIG_ENV_OFFSET:
3741 Offset of environment data (variable area) to the
3742 beginning of flash memory; for instance, with bottom boot
3743 type flash chips the second sector can be used: the offset
3744 for this sector is given here.
3746 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3750 This is just another way to specify the start address of
3751 the flash sector containing the environment (instead of
3754 - CONFIG_ENV_SECT_SIZE:
3756 Size of the sector containing the environment.
3759 b) Sometimes flash chips have few, equal sized, BIG sectors.
3760 In such a case you don't want to spend a whole sector for
3765 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3766 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3767 of this flash sector for the environment. This saves
3768 memory for the RAM copy of the environment.
3770 It may also save flash memory if you decide to use this
3771 when your environment is "embedded" within U-Boot code,
3772 since then the remainder of the flash sector could be used
3773 for U-Boot code. It should be pointed out that this is
3774 STRONGLY DISCOURAGED from a robustness point of view:
3775 updating the environment in flash makes it always
3776 necessary to erase the WHOLE sector. If something goes
3777 wrong before the contents has been restored from a copy in
3778 RAM, your target system will be dead.
3780 - CONFIG_ENV_ADDR_REDUND
3781 CONFIG_ENV_SIZE_REDUND
3783 These settings describe a second storage area used to hold
3784 a redundant copy of the environment data, so that there is
3785 a valid backup copy in case there is a power failure during
3786 a "saveenv" operation.
3788 BE CAREFUL! Any changes to the flash layout, and some changes to the
3789 source code will make it necessary to adapt <board>/u-boot.lds*
3793 - CONFIG_ENV_IS_IN_NVRAM:
3795 Define this if you have some non-volatile memory device
3796 (NVRAM, battery buffered SRAM) which you want to use for the
3802 These two #defines are used to determine the memory area you
3803 want to use for environment. It is assumed that this memory
3804 can just be read and written to, without any special
3807 BE CAREFUL! The first access to the environment happens quite early
3808 in U-Boot initalization (when we try to get the setting of for the
3809 console baudrate). You *MUST* have mapped your NVRAM area then, or
3812 Please note that even with NVRAM we still use a copy of the
3813 environment in RAM: we could work on NVRAM directly, but we want to
3814 keep settings there always unmodified except somebody uses "saveenv"
3815 to save the current settings.
3818 - CONFIG_ENV_IS_IN_EEPROM:
3820 Use this if you have an EEPROM or similar serial access
3821 device and a driver for it.
3823 - CONFIG_ENV_OFFSET:
3826 These two #defines specify the offset and size of the
3827 environment area within the total memory of your EEPROM.
3829 - CONFIG_SYS_I2C_EEPROM_ADDR:
3830 If defined, specified the chip address of the EEPROM device.
3831 The default address is zero.
3833 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3834 If defined, the number of bits used to address bytes in a
3835 single page in the EEPROM device. A 64 byte page, for example
3836 would require six bits.
3838 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3839 If defined, the number of milliseconds to delay between
3840 page writes. The default is zero milliseconds.
3842 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3843 The length in bytes of the EEPROM memory array address. Note
3844 that this is NOT the chip address length!
3846 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3847 EEPROM chips that implement "address overflow" are ones
3848 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3849 address and the extra bits end up in the "chip address" bit
3850 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3853 Note that we consider the length of the address field to
3854 still be one byte because the extra address bits are hidden
3855 in the chip address.
3857 - CONFIG_SYS_EEPROM_SIZE:
3858 The size in bytes of the EEPROM device.
3860 - CONFIG_ENV_EEPROM_IS_ON_I2C
3861 define this, if you have I2C and SPI activated, and your
3862 EEPROM, which holds the environment, is on the I2C bus.
3864 - CONFIG_I2C_ENV_EEPROM_BUS
3865 if you have an Environment on an EEPROM reached over
3866 I2C muxes, you can define here, how to reach this
3867 EEPROM. For example:
3869 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3871 EEPROM which holds the environment, is reached over
3872 a pca9547 i2c mux with address 0x70, channel 3.
3874 - CONFIG_ENV_IS_IN_DATAFLASH:
3876 Define this if you have a DataFlash memory device which you
3877 want to use for the environment.
3879 - CONFIG_ENV_OFFSET:
3883 These three #defines specify the offset and size of the
3884 environment area within the total memory of your DataFlash placed
3885 at the specified address.
3887 - CONFIG_ENV_IS_IN_REMOTE:
3889 Define this if you have a remote memory space which you
3890 want to use for the local device's environment.
3895 These two #defines specify the address and size of the
3896 environment area within the remote memory space. The
3897 local device can get the environment from remote memory
3898 space by SRIO or PCIE links.
3900 BE CAREFUL! For some special cases, the local device can not use
3901 "saveenv" command. For example, the local device will get the
3902 environment stored in a remote NOR flash by SRIO or PCIE link,
3903 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3905 - CONFIG_ENV_IS_IN_NAND:
3907 Define this if you have a NAND device which you want to use
3908 for the environment.
3910 - CONFIG_ENV_OFFSET:
3913 These two #defines specify the offset and size of the environment
3914 area within the first NAND device. CONFIG_ENV_OFFSET must be
3915 aligned to an erase block boundary.
3917 - CONFIG_ENV_OFFSET_REDUND (optional):
3919 This setting describes a second storage area of CONFIG_ENV_SIZE
3920 size used to hold a redundant copy of the environment data, so
3921 that there is a valid backup copy in case there is a power failure
3922 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3923 aligned to an erase block boundary.
3925 - CONFIG_ENV_RANGE (optional):
3927 Specifies the length of the region in which the environment
3928 can be written. This should be a multiple of the NAND device's
3929 block size. Specifying a range with more erase blocks than
3930 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3931 the range to be avoided.
3933 - CONFIG_ENV_OFFSET_OOB (optional):
3935 Enables support for dynamically retrieving the offset of the
3936 environment from block zero's out-of-band data. The
3937 "nand env.oob" command can be used to record this offset.
3938 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3939 using CONFIG_ENV_OFFSET_OOB.
3941 - CONFIG_NAND_ENV_DST
3943 Defines address in RAM to which the nand_spl code should copy the
3944 environment. If redundant environment is used, it will be copied to
3945 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3947 - CONFIG_ENV_IS_IN_UBI:
3949 Define this if you have an UBI volume that you want to use for the
3950 environment. This has the benefit of wear-leveling the environment
3951 accesses, which is important on NAND.
3953 - CONFIG_ENV_UBI_PART:
3955 Define this to a string that is the mtd partition containing the UBI.
3957 - CONFIG_ENV_UBI_VOLUME:
3959 Define this to the name of the volume that you want to store the
3962 - CONFIG_ENV_UBI_VOLUME_REDUND:
3964 Define this to the name of another volume to store a second copy of
3965 the environment in. This will enable redundant environments in UBI.
3966 It is assumed that both volumes are in the same MTD partition.
3968 - CONFIG_UBI_SILENCE_MSG
3969 - CONFIG_UBIFS_SILENCE_MSG
3971 You will probably want to define these to avoid a really noisy system
3972 when storing the env in UBI.
3974 - CONFIG_ENV_IS_IN_MMC:
3976 Define this if you have an MMC device which you want to use for the
3979 - CONFIG_SYS_MMC_ENV_DEV:
3981 Specifies which MMC device the environment is stored in.
3983 - CONFIG_SYS_MMC_ENV_PART (optional):
3985 Specifies which MMC partition the environment is stored in. If not
3986 set, defaults to partition 0, the user area. Common values might be
3987 1 (first MMC boot partition), 2 (second MMC boot partition).
3989 - CONFIG_ENV_OFFSET:
3992 These two #defines specify the offset and size of the environment
3993 area within the specified MMC device.
3995 If offset is positive (the usual case), it is treated as relative to
3996 the start of the MMC partition. If offset is negative, it is treated
3997 as relative to the end of the MMC partition. This can be useful if
3998 your board may be fitted with different MMC devices, which have
3999 different sizes for the MMC partitions, and you always want the
4000 environment placed at the very end of the partition, to leave the
4001 maximum possible space before it, to store other data.
4003 These two values are in units of bytes, but must be aligned to an
4004 MMC sector boundary.
4006 - CONFIG_ENV_OFFSET_REDUND (optional):
4008 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4009 hold a redundant copy of the environment data. This provides a
4010 valid backup copy in case the other copy is corrupted, e.g. due
4011 to a power failure during a "saveenv" operation.
4013 This value may also be positive or negative; this is handled in the
4014 same way as CONFIG_ENV_OFFSET.
4016 This value is also in units of bytes, but must also be aligned to
4017 an MMC sector boundary.
4019 - CONFIG_ENV_SIZE_REDUND (optional):
4021 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4022 set. If this value is set, it must be set to the same value as
4025 - CONFIG_SYS_SPI_INIT_OFFSET
4027 Defines offset to the initial SPI buffer area in DPRAM. The
4028 area is used at an early stage (ROM part) if the environment
4029 is configured to reside in the SPI EEPROM: We need a 520 byte
4030 scratch DPRAM area. It is used between the two initialization
4031 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4032 to be a good choice since it makes it far enough from the
4033 start of the data area as well as from the stack pointer.
4035 Please note that the environment is read-only until the monitor
4036 has been relocated to RAM and a RAM copy of the environment has been
4037 created; also, when using EEPROM you will have to use getenv_f()
4038 until then to read environment variables.
4040 The environment is protected by a CRC32 checksum. Before the monitor
4041 is relocated into RAM, as a result of a bad CRC you will be working
4042 with the compiled-in default environment - *silently*!!! [This is
4043 necessary, because the first environment variable we need is the
4044 "baudrate" setting for the console - if we have a bad CRC, we don't
4045 have any device yet where we could complain.]
4047 Note: once the monitor has been relocated, then it will complain if
4048 the default environment is used; a new CRC is computed as soon as you
4049 use the "saveenv" command to store a valid environment.
4051 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4052 Echo the inverted Ethernet link state to the fault LED.
4054 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4055 also needs to be defined.
4057 - CONFIG_SYS_FAULT_MII_ADDR:
4058 MII address of the PHY to check for the Ethernet link state.
4060 - CONFIG_NS16550_MIN_FUNCTIONS:
4061 Define this if you desire to only have use of the NS16550_init
4062 and NS16550_putc functions for the serial driver located at
4063 drivers/serial/ns16550.c. This option is useful for saving
4064 space for already greatly restricted images, including but not
4065 limited to NAND_SPL configurations.
4067 - CONFIG_DISPLAY_BOARDINFO
4068 Display information about the board that U-Boot is running on
4069 when U-Boot starts up. The board function checkboard() is called
4072 - CONFIG_DISPLAY_BOARDINFO_LATE
4073 Similar to the previous option, but display this information
4074 later, once stdio is running and output goes to the LCD, if
4077 Low Level (hardware related) configuration options:
4078 ---------------------------------------------------
4080 - CONFIG_SYS_CACHELINE_SIZE:
4081 Cache Line Size of the CPU.
4083 - CONFIG_SYS_DEFAULT_IMMR:
4084 Default address of the IMMR after system reset.
4086 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4087 and RPXsuper) to be able to adjust the position of
4088 the IMMR register after a reset.
4090 - CONFIG_SYS_CCSRBAR_DEFAULT:
4091 Default (power-on reset) physical address of CCSR on Freescale
4094 - CONFIG_SYS_CCSRBAR:
4095 Virtual address of CCSR. On a 32-bit build, this is typically
4096 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4098 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4099 for cross-platform code that uses that macro instead.
4101 - CONFIG_SYS_CCSRBAR_PHYS:
4102 Physical address of CCSR. CCSR can be relocated to a new
4103 physical address, if desired. In this case, this macro should
4104 be set to that address. Otherwise, it should be set to the
4105 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4106 is typically relocated on 36-bit builds. It is recommended
4107 that this macro be defined via the _HIGH and _LOW macros:
4109 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4110 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4112 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4113 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4114 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4115 used in assembly code, so it must not contain typecasts or
4116 integer size suffixes (e.g. "ULL").
4118 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4119 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4120 used in assembly code, so it must not contain typecasts or
4121 integer size suffixes (e.g. "ULL").
4123 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4124 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4125 forced to a value that ensures that CCSR is not relocated.
4127 - Floppy Disk Support:
4128 CONFIG_SYS_FDC_DRIVE_NUMBER
4130 the default drive number (default value 0)
4132 CONFIG_SYS_ISA_IO_STRIDE
4134 defines the spacing between FDC chipset registers
4137 CONFIG_SYS_ISA_IO_OFFSET
4139 defines the offset of register from address. It
4140 depends on which part of the data bus is connected to
4141 the FDC chipset. (default value 0)
4143 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4144 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4147 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4148 fdc_hw_init() is called at the beginning of the FDC
4149 setup. fdc_hw_init() must be provided by the board
4150 source code. It is used to make hardware dependant
4154 Most IDE controllers were designed to be connected with PCI
4155 interface. Only few of them were designed for AHB interface.
4156 When software is doing ATA command and data transfer to
4157 IDE devices through IDE-AHB controller, some additional
4158 registers accessing to these kind of IDE-AHB controller
4161 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4162 DO NOT CHANGE unless you know exactly what you're
4163 doing! (11-4) [MPC8xx/82xx systems only]
4165 - CONFIG_SYS_INIT_RAM_ADDR:
4167 Start address of memory area that can be used for
4168 initial data and stack; please note that this must be
4169 writable memory that is working WITHOUT special
4170 initialization, i. e. you CANNOT use normal RAM which
4171 will become available only after programming the
4172 memory controller and running certain initialization
4175 U-Boot uses the following memory types:
4176 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4177 - MPC824X: data cache
4178 - PPC4xx: data cache
4180 - CONFIG_SYS_GBL_DATA_OFFSET:
4182 Offset of the initial data structure in the memory
4183 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4184 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4185 data is located at the end of the available space
4186 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4187 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4188 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4189 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4192 On the MPC824X (or other systems that use the data
4193 cache for initial memory) the address chosen for
4194 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4195 point to an otherwise UNUSED address space between
4196 the top of RAM and the start of the PCI space.
4198 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4200 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4202 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4204 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4206 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4208 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4210 - CONFIG_SYS_OR_TIMING_SDRAM:
4213 - CONFIG_SYS_MAMR_PTA:
4214 periodic timer for refresh
4216 - CONFIG_SYS_DER: Debug Event Register (37-47)
4218 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4219 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4220 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4221 CONFIG_SYS_BR1_PRELIM:
4222 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4224 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4225 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4226 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4227 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4229 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4230 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4231 Machine Mode Register and Memory Periodic Timer
4232 Prescaler definitions (SDRAM timing)
4234 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4235 enable I2C microcode relocation patch (MPC8xx);
4236 define relocation offset in DPRAM [DSP2]
4238 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4239 enable SMC microcode relocation patch (MPC8xx);
4240 define relocation offset in DPRAM [SMC1]
4242 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4243 enable SPI microcode relocation patch (MPC8xx);
4244 define relocation offset in DPRAM [SCC4]
4246 - CONFIG_SYS_USE_OSCCLK:
4247 Use OSCM clock mode on MBX8xx board. Be careful,
4248 wrong setting might damage your board. Read
4249 doc/README.MBX before setting this variable!
4251 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4252 Offset of the bootmode word in DPRAM used by post
4253 (Power On Self Tests). This definition overrides
4254 #define'd default value in commproc.h resp.
4257 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4258 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4259 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4260 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4261 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4262 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4263 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4264 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4265 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4267 - CONFIG_PCI_DISABLE_PCIE:
4268 Disable PCI-Express on systems where it is supported but not
4271 - CONFIG_PCI_ENUM_ONLY
4272 Only scan through and get the devices on the busses.
4273 Don't do any setup work, presumably because someone or
4274 something has already done it, and we don't need to do it
4275 a second time. Useful for platforms that are pre-booted
4276 by coreboot or similar.
4278 - CONFIG_PCI_INDIRECT_BRIDGE:
4279 Enable support for indirect PCI bridges.
4282 Chip has SRIO or not
4285 Board has SRIO 1 port available
4288 Board has SRIO 2 port available
4290 - CONFIG_SRIO_PCIE_BOOT_MASTER
4291 Board can support master function for Boot from SRIO and PCIE
4293 - CONFIG_SYS_SRIOn_MEM_VIRT:
4294 Virtual Address of SRIO port 'n' memory region
4296 - CONFIG_SYS_SRIOn_MEM_PHYS:
4297 Physical Address of SRIO port 'n' memory region
4299 - CONFIG_SYS_SRIOn_MEM_SIZE:
4300 Size of SRIO port 'n' memory region
4302 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4303 Defined to tell the NAND controller that the NAND chip is using
4305 Not all NAND drivers use this symbol.
4306 Example of drivers that use it:
4307 - drivers/mtd/nand/ndfc.c
4308 - drivers/mtd/nand/mxc_nand.c
4310 - CONFIG_SYS_NDFC_EBC0_CFG
4311 Sets the EBC0_CFG register for the NDFC. If not defined
4312 a default value will be used.
4315 Get DDR timing information from an I2C EEPROM. Common
4316 with pluggable memory modules such as SODIMMs
4319 I2C address of the SPD EEPROM
4321 - CONFIG_SYS_SPD_BUS_NUM
4322 If SPD EEPROM is on an I2C bus other than the first
4323 one, specify here. Note that the value must resolve
4324 to something your driver can deal with.
4326 - CONFIG_SYS_DDR_RAW_TIMING
4327 Get DDR timing information from other than SPD. Common with
4328 soldered DDR chips onboard without SPD. DDR raw timing
4329 parameters are extracted from datasheet and hard-coded into
4330 header files or board specific files.
4332 - CONFIG_FSL_DDR_INTERACTIVE
4333 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4335 - CONFIG_SYS_83XX_DDR_USES_CS0
4336 Only for 83xx systems. If specified, then DDR should
4337 be configured using CS0 and CS1 instead of CS2 and CS3.
4339 - CONFIG_ETHER_ON_FEC[12]
4340 Define to enable FEC[12] on a 8xx series processor.
4342 - CONFIG_FEC[12]_PHY
4343 Define to the hardcoded PHY address which corresponds
4344 to the given FEC; i. e.
4345 #define CONFIG_FEC1_PHY 4
4346 means that the PHY with address 4 is connected to FEC1
4348 When set to -1, means to probe for first available.
4350 - CONFIG_FEC[12]_PHY_NORXERR
4351 The PHY does not have a RXERR line (RMII only).
4352 (so program the FEC to ignore it).
4355 Enable RMII mode for all FECs.
4356 Note that this is a global option, we can't
4357 have one FEC in standard MII mode and another in RMII mode.
4359 - CONFIG_CRC32_VERIFY
4360 Add a verify option to the crc32 command.
4363 => crc32 -v <address> <count> <crc32>
4365 Where address/count indicate a memory area
4366 and crc32 is the correct crc32 which the
4370 Add the "loopw" memory command. This only takes effect if
4371 the memory commands are activated globally (CONFIG_CMD_MEM).
4374 Add the "mdc" and "mwc" memory commands. These are cyclic
4379 This command will print 4 bytes (10,11,12,13) each 500 ms.
4381 => mwc.l 100 12345678 10
4382 This command will write 12345678 to address 100 all 10 ms.
4384 This only takes effect if the memory commands are activated
4385 globally (CONFIG_CMD_MEM).
4387 - CONFIG_SKIP_LOWLEVEL_INIT
4388 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4389 low level initializations (like setting up the memory
4390 controller) are omitted and/or U-Boot does not
4391 relocate itself into RAM.
4393 Normally this variable MUST NOT be defined. The only
4394 exception is when U-Boot is loaded (to RAM) by some
4395 other boot loader or by a debugger which performs
4396 these initializations itself.
4399 Modifies the behaviour of start.S when compiling a loader
4400 that is executed before the actual U-Boot. E.g. when
4401 compiling a NAND SPL.
4404 Modifies the behaviour of start.S when compiling a loader
4405 that is executed after the SPL and before the actual U-Boot.
4406 It is loaded by the SPL.
4408 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4409 Only for 85xx systems. If this variable is specified, the section
4410 .resetvec is not kept and the section .bootpg is placed in the
4411 previous 4k of the .text section.
4413 - CONFIG_ARCH_MAP_SYSMEM
4414 Generally U-Boot (and in particular the md command) uses
4415 effective address. It is therefore not necessary to regard
4416 U-Boot address as virtual addresses that need to be translated
4417 to physical addresses. However, sandbox requires this, since
4418 it maintains its own little RAM buffer which contains all
4419 addressable memory. This option causes some memory accesses
4420 to be mapped through map_sysmem() / unmap_sysmem().
4422 - CONFIG_USE_ARCH_MEMCPY
4423 CONFIG_USE_ARCH_MEMSET
4424 If these options are used a optimized version of memcpy/memset will
4425 be used if available. These functions may be faster under some
4426 conditions but may increase the binary size.
4428 - CONFIG_X86_RESET_VECTOR
4429 If defined, the x86 reset vector code is included. This is not
4430 needed when U-Boot is running from Coreboot.
4433 Defines the MPU clock speed (in MHz).
4435 NOTE : currently only supported on AM335x platforms.
4437 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4438 Enables the RTC32K OSC on AM33xx based plattforms
4440 Freescale QE/FMAN Firmware Support:
4441 -----------------------------------
4443 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4444 loading of "firmware", which is encoded in the QE firmware binary format.
4445 This firmware often needs to be loaded during U-Boot booting, so macros
4446 are used to identify the storage device (NOR flash, SPI, etc) and the address
4449 - CONFIG_SYS_QE_FMAN_FW_ADDR
4450 The address in the storage device where the firmware is located. The
4451 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4454 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4455 The maximum possible size of the firmware. The firmware binary format
4456 has a field that specifies the actual size of the firmware, but it
4457 might not be possible to read any part of the firmware unless some
4458 local storage is allocated to hold the entire firmware first.
4460 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4461 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4462 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4463 virtual address in NOR flash.
4465 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4466 Specifies that QE/FMAN firmware is located in NAND flash.
4467 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4469 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4470 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4471 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4473 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4474 Specifies that QE/FMAN firmware is located on the primary SPI
4475 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4477 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4478 Specifies that QE/FMAN firmware is located in the remote (master)
4479 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4480 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4481 window->master inbound window->master LAW->the ucode address in
4482 master's memory space.
4484 Building the Software:
4485 ======================
4487 Building U-Boot has been tested in several native build environments
4488 and in many different cross environments. Of course we cannot support
4489 all possibly existing versions of cross development tools in all
4490 (potentially obsolete) versions. In case of tool chain problems we
4491 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4492 which is extensively used to build and test U-Boot.
4494 If you are not using a native environment, it is assumed that you
4495 have GNU cross compiling tools available in your path. In this case,
4496 you must set the environment variable CROSS_COMPILE in your shell.
4497 Note that no changes to the Makefile or any other source files are
4498 necessary. For example using the ELDK on a 4xx CPU, please enter:
4500 $ CROSS_COMPILE=ppc_4xx-
4501 $ export CROSS_COMPILE
4503 Note: If you wish to generate Windows versions of the utilities in
4504 the tools directory you can use the MinGW toolchain
4505 (http://www.mingw.org). Set your HOST tools to the MinGW
4506 toolchain and execute 'make tools'. For example:
4508 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4510 Binaries such as tools/mkimage.exe will be created which can
4511 be executed on computers running Windows.
4513 U-Boot is intended to be simple to build. After installing the
4514 sources you must configure U-Boot for one specific board type. This
4519 where "NAME_config" is the name of one of the existing configu-
4520 rations; see boards.cfg for supported names.
4522 Note: for some board special configuration names may exist; check if
4523 additional information is available from the board vendor; for
4524 instance, the TQM823L systems are available without (standard)
4525 or with LCD support. You can select such additional "features"
4526 when choosing the configuration, i. e.
4529 - will configure for a plain TQM823L, i. e. no LCD support
4531 make TQM823L_LCD_config
4532 - will configure for a TQM823L with U-Boot console on LCD
4537 Finally, type "make all", and you should get some working U-Boot
4538 images ready for download to / installation on your system:
4540 - "u-boot.bin" is a raw binary image
4541 - "u-boot" is an image in ELF binary format
4542 - "u-boot.srec" is in Motorola S-Record format
4544 By default the build is performed locally and the objects are saved
4545 in the source directory. One of the two methods can be used to change
4546 this behavior and build U-Boot to some external directory:
4548 1. Add O= to the make command line invocations:
4550 make O=/tmp/build distclean
4551 make O=/tmp/build NAME_config
4552 make O=/tmp/build all
4554 2. Set environment variable BUILD_DIR to point to the desired location:
4556 export BUILD_DIR=/tmp/build
4561 Note that the command line "O=" setting overrides the BUILD_DIR environment
4565 Please be aware that the Makefiles assume you are using GNU make, so
4566 for instance on NetBSD you might need to use "gmake" instead of
4570 If the system board that you have is not listed, then you will need
4571 to port U-Boot to your hardware platform. To do this, follow these
4574 1. Add a new configuration option for your board to the toplevel
4575 "boards.cfg" file, using the existing entries as examples.
4576 Follow the instructions there to keep the boards in order.
4577 2. Create a new directory to hold your board specific code. Add any
4578 files you need. In your board directory, you will need at least
4579 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4580 3. Create a new configuration file "include/configs/<board>.h" for
4582 3. If you're porting U-Boot to a new CPU, then also create a new
4583 directory to hold your CPU specific code. Add any files you need.
4584 4. Run "make <board>_config" with your new name.
4585 5. Type "make", and you should get a working "u-boot.srec" file
4586 to be installed on your target system.
4587 6. Debug and solve any problems that might arise.
4588 [Of course, this last step is much harder than it sounds.]
4591 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4592 ==============================================================
4594 If you have modified U-Boot sources (for instance added a new board
4595 or support for new devices, a new CPU, etc.) you are expected to
4596 provide feedback to the other developers. The feedback normally takes
4597 the form of a "patch", i. e. a context diff against a certain (latest
4598 official or latest in the git repository) version of U-Boot sources.
4600 But before you submit such a patch, please verify that your modifi-
4601 cation did not break existing code. At least make sure that *ALL* of
4602 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4603 just run the "MAKEALL" script, which will configure and build U-Boot
4604 for ALL supported system. Be warned, this will take a while. You can
4605 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4606 environment variable to the script, i. e. to use the ELDK cross tools
4609 CROSS_COMPILE=ppc_8xx- MAKEALL
4611 or to build on a native PowerPC system you can type
4613 CROSS_COMPILE=' ' MAKEALL
4615 When using the MAKEALL script, the default behaviour is to build
4616 U-Boot in the source directory. This location can be changed by
4617 setting the BUILD_DIR environment variable. Also, for each target
4618 built, the MAKEALL script saves two log files (<target>.ERR and
4619 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4620 location can be changed by setting the MAKEALL_LOGDIR environment
4621 variable. For example:
4623 export BUILD_DIR=/tmp/build
4624 export MAKEALL_LOGDIR=/tmp/log
4625 CROSS_COMPILE=ppc_8xx- MAKEALL
4627 With the above settings build objects are saved in the /tmp/build,
4628 log files are saved in the /tmp/log and the source tree remains clean
4629 during the whole build process.
4632 See also "U-Boot Porting Guide" below.
4635 Monitor Commands - Overview:
4636 ============================
4638 go - start application at address 'addr'
4639 run - run commands in an environment variable
4640 bootm - boot application image from memory
4641 bootp - boot image via network using BootP/TFTP protocol
4642 bootz - boot zImage from memory
4643 tftpboot- boot image via network using TFTP protocol
4644 and env variables "ipaddr" and "serverip"
4645 (and eventually "gatewayip")
4646 tftpput - upload a file via network using TFTP protocol
4647 rarpboot- boot image via network using RARP/TFTP protocol
4648 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4649 loads - load S-Record file over serial line
4650 loadb - load binary file over serial line (kermit mode)
4652 mm - memory modify (auto-incrementing)
4653 nm - memory modify (constant address)
4654 mw - memory write (fill)
4656 cmp - memory compare
4657 crc32 - checksum calculation
4658 i2c - I2C sub-system
4659 sspi - SPI utility commands
4660 base - print or set address offset
4661 printenv- print environment variables
4662 setenv - set environment variables
4663 saveenv - save environment variables to persistent storage
4664 protect - enable or disable FLASH write protection
4665 erase - erase FLASH memory
4666 flinfo - print FLASH memory information
4667 nand - NAND memory operations (see doc/README.nand)
4668 bdinfo - print Board Info structure
4669 iminfo - print header information for application image
4670 coninfo - print console devices and informations
4671 ide - IDE sub-system
4672 loop - infinite loop on address range
4673 loopw - infinite write loop on address range
4674 mtest - simple RAM test
4675 icache - enable or disable instruction cache
4676 dcache - enable or disable data cache
4677 reset - Perform RESET of the CPU
4678 echo - echo args to console
4679 version - print monitor version
4680 help - print online help
4681 ? - alias for 'help'
4684 Monitor Commands - Detailed Description:
4685 ========================================
4689 For now: just type "help <command>".
4692 Environment Variables:
4693 ======================
4695 U-Boot supports user configuration using Environment Variables which
4696 can be made persistent by saving to Flash memory.
4698 Environment Variables are set using "setenv", printed using
4699 "printenv", and saved to Flash using "saveenv". Using "setenv"
4700 without a value can be used to delete a variable from the
4701 environment. As long as you don't save the environment you are
4702 working with an in-memory copy. In case the Flash area containing the
4703 environment is erased by accident, a default environment is provided.
4705 Some configuration options can be set using Environment Variables.
4707 List of environment variables (most likely not complete):
4709 baudrate - see CONFIG_BAUDRATE
4711 bootdelay - see CONFIG_BOOTDELAY
4713 bootcmd - see CONFIG_BOOTCOMMAND
4715 bootargs - Boot arguments when booting an RTOS image
4717 bootfile - Name of the image to load with TFTP
4719 bootm_low - Memory range available for image processing in the bootm
4720 command can be restricted. This variable is given as
4721 a hexadecimal number and defines lowest address allowed
4722 for use by the bootm command. See also "bootm_size"
4723 environment variable. Address defined by "bootm_low" is
4724 also the base of the initial memory mapping for the Linux
4725 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4728 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4729 This variable is given as a hexadecimal number and it
4730 defines the size of the memory region starting at base
4731 address bootm_low that is accessible by the Linux kernel
4732 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4733 as the default value if it is defined, and bootm_size is
4736 bootm_size - Memory range available for image processing in the bootm
4737 command can be restricted. This variable is given as
4738 a hexadecimal number and defines the size of the region
4739 allowed for use by the bootm command. See also "bootm_low"
4740 environment variable.
4742 updatefile - Location of the software update file on a TFTP server, used
4743 by the automatic software update feature. Please refer to
4744 documentation in doc/README.update for more details.
4746 autoload - if set to "no" (any string beginning with 'n'),
4747 "bootp" will just load perform a lookup of the
4748 configuration from the BOOTP server, but not try to
4749 load any image using TFTP
4751 autostart - if set to "yes", an image loaded using the "bootp",
4752 "rarpboot", "tftpboot" or "diskboot" commands will
4753 be automatically started (by internally calling
4756 If set to "no", a standalone image passed to the
4757 "bootm" command will be copied to the load address
4758 (and eventually uncompressed), but NOT be started.
4759 This can be used to load and uncompress arbitrary
4762 fdt_high - if set this restricts the maximum address that the
4763 flattened device tree will be copied into upon boot.
4764 For example, if you have a system with 1 GB memory
4765 at physical address 0x10000000, while Linux kernel
4766 only recognizes the first 704 MB as low memory, you
4767 may need to set fdt_high as 0x3C000000 to have the
4768 device tree blob be copied to the maximum address
4769 of the 704 MB low memory, so that Linux kernel can
4770 access it during the boot procedure.
4772 If this is set to the special value 0xFFFFFFFF then
4773 the fdt will not be copied at all on boot. For this
4774 to work it must reside in writable memory, have
4775 sufficient padding on the end of it for u-boot to
4776 add the information it needs into it, and the memory
4777 must be accessible by the kernel.
4779 fdtcontroladdr- if set this is the address of the control flattened
4780 device tree used by U-Boot when CONFIG_OF_CONTROL is
4783 i2cfast - (PPC405GP|PPC405EP only)
4784 if set to 'y' configures Linux I2C driver for fast
4785 mode (400kHZ). This environment variable is used in
4786 initialization code. So, for changes to be effective
4787 it must be saved and board must be reset.
4789 initrd_high - restrict positioning of initrd images:
4790 If this variable is not set, initrd images will be
4791 copied to the highest possible address in RAM; this
4792 is usually what you want since it allows for
4793 maximum initrd size. If for some reason you want to
4794 make sure that the initrd image is loaded below the
4795 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4796 variable to a value of "no" or "off" or "0".
4797 Alternatively, you can set it to a maximum upper
4798 address to use (U-Boot will still check that it
4799 does not overwrite the U-Boot stack and data).
4801 For instance, when you have a system with 16 MB
4802 RAM, and want to reserve 4 MB from use by Linux,
4803 you can do this by adding "mem=12M" to the value of
4804 the "bootargs" variable. However, now you must make
4805 sure that the initrd image is placed in the first
4806 12 MB as well - this can be done with
4808 setenv initrd_high 00c00000
4810 If you set initrd_high to 0xFFFFFFFF, this is an
4811 indication to U-Boot that all addresses are legal
4812 for the Linux kernel, including addresses in flash
4813 memory. In this case U-Boot will NOT COPY the
4814 ramdisk at all. This may be useful to reduce the
4815 boot time on your system, but requires that this
4816 feature is supported by your Linux kernel.
4818 ipaddr - IP address; needed for tftpboot command
4820 loadaddr - Default load address for commands like "bootp",
4821 "rarpboot", "tftpboot", "loadb" or "diskboot"
4823 loads_echo - see CONFIG_LOADS_ECHO
4825 serverip - TFTP server IP address; needed for tftpboot command
4827 bootretry - see CONFIG_BOOT_RETRY_TIME
4829 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4831 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4833 ethprime - controls which interface is used first.
4835 ethact - controls which interface is currently active.
4836 For example you can do the following
4838 => setenv ethact FEC
4839 => ping 192.168.0.1 # traffic sent on FEC
4840 => setenv ethact SCC
4841 => ping 10.0.0.1 # traffic sent on SCC
4843 ethrotate - When set to "no" U-Boot does not go through all
4844 available network interfaces.
4845 It just stays at the currently selected interface.
4847 netretry - When set to "no" each network operation will
4848 either succeed or fail without retrying.
4849 When set to "once" the network operation will
4850 fail when all the available network interfaces
4851 are tried once without success.
4852 Useful on scripts which control the retry operation
4855 npe_ucode - set load address for the NPE microcode
4857 silent_linux - If set then linux will be told to boot silently, by
4858 changing the console to be empty. If "yes" it will be
4859 made silent. If "no" it will not be made silent. If
4860 unset, then it will be made silent if the U-Boot console
4863 tftpsrcport - If this is set, the value is used for TFTP's
4866 tftpdstport - If this is set, the value is used for TFTP's UDP
4867 destination port instead of the Well Know Port 69.
4869 tftpblocksize - Block size to use for TFTP transfers; if not set,
4870 we use the TFTP server's default block size
4872 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4873 seconds, minimum value is 1000 = 1 second). Defines
4874 when a packet is considered to be lost so it has to
4875 be retransmitted. The default is 5000 = 5 seconds.
4876 Lowering this value may make downloads succeed
4877 faster in networks with high packet loss rates or
4878 with unreliable TFTP servers.
4880 vlan - When set to a value < 4095 the traffic over
4881 Ethernet is encapsulated/received over 802.1q
4884 The following image location variables contain the location of images
4885 used in booting. The "Image" column gives the role of the image and is
4886 not an environment variable name. The other columns are environment
4887 variable names. "File Name" gives the name of the file on a TFTP
4888 server, "RAM Address" gives the location in RAM the image will be
4889 loaded to, and "Flash Location" gives the image's address in NOR
4890 flash or offset in NAND flash.
4892 *Note* - these variables don't have to be defined for all boards, some
4893 boards currenlty use other variables for these purposes, and some
4894 boards use these variables for other purposes.
4896 Image File Name RAM Address Flash Location
4897 ----- --------- ----------- --------------
4898 u-boot u-boot u-boot_addr_r u-boot_addr
4899 Linux kernel bootfile kernel_addr_r kernel_addr
4900 device tree blob fdtfile fdt_addr_r fdt_addr
4901 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4903 The following environment variables may be used and automatically
4904 updated by the network boot commands ("bootp" and "rarpboot"),
4905 depending the information provided by your boot server:
4907 bootfile - see above
4908 dnsip - IP address of your Domain Name Server
4909 dnsip2 - IP address of your secondary Domain Name Server
4910 gatewayip - IP address of the Gateway (Router) to use
4911 hostname - Target hostname
4913 netmask - Subnet Mask
4914 rootpath - Pathname of the root filesystem on the NFS server
4915 serverip - see above
4918 There are two special Environment Variables:
4920 serial# - contains hardware identification information such
4921 as type string and/or serial number
4922 ethaddr - Ethernet address
4924 These variables can be set only once (usually during manufacturing of
4925 the board). U-Boot refuses to delete or overwrite these variables
4926 once they have been set once.
4929 Further special Environment Variables:
4931 ver - Contains the U-Boot version string as printed
4932 with the "version" command. This variable is
4933 readonly (see CONFIG_VERSION_VARIABLE).
4936 Please note that changes to some configuration parameters may take
4937 only effect after the next boot (yes, that's just like Windoze :-).
4940 Callback functions for environment variables:
4941 ---------------------------------------------
4943 For some environment variables, the behavior of u-boot needs to change
4944 when their values are changed. This functionailty allows functions to
4945 be associated with arbitrary variables. On creation, overwrite, or
4946 deletion, the callback will provide the opportunity for some side
4947 effect to happen or for the change to be rejected.
4949 The callbacks are named and associated with a function using the
4950 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4952 These callbacks are associated with variables in one of two ways. The
4953 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4954 in the board configuration to a string that defines a list of
4955 associations. The list must be in the following format:
4957 entry = variable_name[:callback_name]
4960 If the callback name is not specified, then the callback is deleted.
4961 Spaces are also allowed anywhere in the list.
4963 Callbacks can also be associated by defining the ".callbacks" variable
4964 with the same list format above. Any association in ".callbacks" will
4965 override any association in the static list. You can define
4966 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4967 ".callbacks" envirnoment variable in the default or embedded environment.
4970 Command Line Parsing:
4971 =====================
4973 There are two different command line parsers available with U-Boot:
4974 the old "simple" one, and the much more powerful "hush" shell:
4976 Old, simple command line parser:
4977 --------------------------------
4979 - supports environment variables (through setenv / saveenv commands)
4980 - several commands on one line, separated by ';'
4981 - variable substitution using "... ${name} ..." syntax
4982 - special characters ('$', ';') can be escaped by prefixing with '\',
4984 setenv bootcmd bootm \${address}
4985 - You can also escape text by enclosing in single apostrophes, for example:
4986 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4991 - similar to Bourne shell, with control structures like
4992 if...then...else...fi, for...do...done; while...do...done,
4993 until...do...done, ...
4994 - supports environment ("global") variables (through setenv / saveenv
4995 commands) and local shell variables (through standard shell syntax
4996 "name=value"); only environment variables can be used with "run"
5002 (1) If a command line (or an environment variable executed by a "run"
5003 command) contains several commands separated by semicolon, and
5004 one of these commands fails, then the remaining commands will be
5007 (2) If you execute several variables with one call to run (i. e.
5008 calling run with a list of variables as arguments), any failing
5009 command will cause "run" to terminate, i. e. the remaining
5010 variables are not executed.
5012 Note for Redundant Ethernet Interfaces:
5013 =======================================
5015 Some boards come with redundant Ethernet interfaces; U-Boot supports
5016 such configurations and is capable of automatic selection of a
5017 "working" interface when needed. MAC assignment works as follows:
5019 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5020 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5021 "eth1addr" (=>eth1), "eth2addr", ...
5023 If the network interface stores some valid MAC address (for instance
5024 in SROM), this is used as default address if there is NO correspon-
5025 ding setting in the environment; if the corresponding environment
5026 variable is set, this overrides the settings in the card; that means:
5028 o If the SROM has a valid MAC address, and there is no address in the
5029 environment, the SROM's address is used.
5031 o If there is no valid address in the SROM, and a definition in the
5032 environment exists, then the value from the environment variable is
5035 o If both the SROM and the environment contain a MAC address, and
5036 both addresses are the same, this MAC address is used.
5038 o If both the SROM and the environment contain a MAC address, and the
5039 addresses differ, the value from the environment is used and a
5042 o If neither SROM nor the environment contain a MAC address, an error
5045 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5046 will be programmed into hardware as part of the initialization process. This
5047 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5048 The naming convention is as follows:
5049 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5054 U-Boot is capable of booting (and performing other auxiliary operations on)
5055 images in two formats:
5057 New uImage format (FIT)
5058 -----------------------
5060 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5061 to Flattened Device Tree). It allows the use of images with multiple
5062 components (several kernels, ramdisks, etc.), with contents protected by
5063 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5069 Old image format is based on binary files which can be basically anything,
5070 preceded by a special header; see the definitions in include/image.h for
5071 details; basically, the header defines the following image properties:
5073 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5074 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5075 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5076 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5078 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5079 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5080 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5081 * Compression Type (uncompressed, gzip, bzip2)
5087 The header is marked by a special Magic Number, and both the header
5088 and the data portions of the image are secured against corruption by
5095 Although U-Boot should support any OS or standalone application
5096 easily, the main focus has always been on Linux during the design of
5099 U-Boot includes many features that so far have been part of some
5100 special "boot loader" code within the Linux kernel. Also, any
5101 "initrd" images to be used are no longer part of one big Linux image;
5102 instead, kernel and "initrd" are separate images. This implementation
5103 serves several purposes:
5105 - the same features can be used for other OS or standalone
5106 applications (for instance: using compressed images to reduce the
5107 Flash memory footprint)
5109 - it becomes much easier to port new Linux kernel versions because
5110 lots of low-level, hardware dependent stuff are done by U-Boot
5112 - the same Linux kernel image can now be used with different "initrd"
5113 images; of course this also means that different kernel images can
5114 be run with the same "initrd". This makes testing easier (you don't
5115 have to build a new "zImage.initrd" Linux image when you just
5116 change a file in your "initrd"). Also, a field-upgrade of the
5117 software is easier now.
5123 Porting Linux to U-Boot based systems:
5124 ---------------------------------------
5126 U-Boot cannot save you from doing all the necessary modifications to
5127 configure the Linux device drivers for use with your target hardware
5128 (no, we don't intend to provide a full virtual machine interface to
5131 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5133 Just make sure your machine specific header file (for instance
5134 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5135 Information structure as we define in include/asm-<arch>/u-boot.h,
5136 and make sure that your definition of IMAP_ADDR uses the same value
5137 as your U-Boot configuration in CONFIG_SYS_IMMR.
5140 Configuring the Linux kernel:
5141 -----------------------------
5143 No specific requirements for U-Boot. Make sure you have some root
5144 device (initial ramdisk, NFS) for your target system.
5147 Building a Linux Image:
5148 -----------------------
5150 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5151 not used. If you use recent kernel source, a new build target
5152 "uImage" will exist which automatically builds an image usable by
5153 U-Boot. Most older kernels also have support for a "pImage" target,
5154 which was introduced for our predecessor project PPCBoot and uses a
5155 100% compatible format.
5164 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5165 encapsulate a compressed Linux kernel image with header information,
5166 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5168 * build a standard "vmlinux" kernel image (in ELF binary format):
5170 * convert the kernel into a raw binary image:
5172 ${CROSS_COMPILE}-objcopy -O binary \
5173 -R .note -R .comment \
5174 -S vmlinux linux.bin
5176 * compress the binary image:
5180 * package compressed binary image for U-Boot:
5182 mkimage -A ppc -O linux -T kernel -C gzip \
5183 -a 0 -e 0 -n "Linux Kernel Image" \
5184 -d linux.bin.gz uImage
5187 The "mkimage" tool can also be used to create ramdisk images for use
5188 with U-Boot, either separated from the Linux kernel image, or
5189 combined into one file. "mkimage" encapsulates the images with a 64
5190 byte header containing information about target architecture,
5191 operating system, image type, compression method, entry points, time
5192 stamp, CRC32 checksums, etc.
5194 "mkimage" can be called in two ways: to verify existing images and
5195 print the header information, or to build new images.
5197 In the first form (with "-l" option) mkimage lists the information
5198 contained in the header of an existing U-Boot image; this includes
5199 checksum verification:
5201 tools/mkimage -l image
5202 -l ==> list image header information
5204 The second form (with "-d" option) is used to build a U-Boot image
5205 from a "data file" which is used as image payload:
5207 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5208 -n name -d data_file image
5209 -A ==> set architecture to 'arch'
5210 -O ==> set operating system to 'os'
5211 -T ==> set image type to 'type'
5212 -C ==> set compression type 'comp'
5213 -a ==> set load address to 'addr' (hex)
5214 -e ==> set entry point to 'ep' (hex)
5215 -n ==> set image name to 'name'
5216 -d ==> use image data from 'datafile'
5218 Right now, all Linux kernels for PowerPC systems use the same load
5219 address (0x00000000), but the entry point address depends on the
5222 - 2.2.x kernels have the entry point at 0x0000000C,
5223 - 2.3.x and later kernels have the entry point at 0x00000000.
5225 So a typical call to build a U-Boot image would read:
5227 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5228 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5229 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5230 > examples/uImage.TQM850L
5231 Image Name: 2.4.4 kernel for TQM850L
5232 Created: Wed Jul 19 02:34:59 2000
5233 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5234 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5235 Load Address: 0x00000000
5236 Entry Point: 0x00000000
5238 To verify the contents of the image (or check for corruption):
5240 -> tools/mkimage -l examples/uImage.TQM850L
5241 Image Name: 2.4.4 kernel for TQM850L
5242 Created: Wed Jul 19 02:34:59 2000
5243 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5244 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5245 Load Address: 0x00000000
5246 Entry Point: 0x00000000
5248 NOTE: for embedded systems where boot time is critical you can trade
5249 speed for memory and install an UNCOMPRESSED image instead: this
5250 needs more space in Flash, but boots much faster since it does not
5251 need to be uncompressed:
5253 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5254 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5255 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5256 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5257 > examples/uImage.TQM850L-uncompressed
5258 Image Name: 2.4.4 kernel for TQM850L
5259 Created: Wed Jul 19 02:34:59 2000
5260 Image Type: PowerPC Linux Kernel Image (uncompressed)
5261 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5262 Load Address: 0x00000000
5263 Entry Point: 0x00000000
5266 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5267 when your kernel is intended to use an initial ramdisk:
5269 -> tools/mkimage -n 'Simple Ramdisk Image' \
5270 > -A ppc -O linux -T ramdisk -C gzip \
5271 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5272 Image Name: Simple Ramdisk Image
5273 Created: Wed Jan 12 14:01:50 2000
5274 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5275 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5276 Load Address: 0x00000000
5277 Entry Point: 0x00000000
5279 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5280 option performs the converse operation of the mkimage's second form (the "-d"
5281 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5284 tools/dumpimage -i image -p position data_file
5285 -i ==> extract from the 'image' a specific 'data_file', \
5286 indexed by 'position'
5289 Installing a Linux Image:
5290 -------------------------
5292 To downloading a U-Boot image over the serial (console) interface,
5293 you must convert the image to S-Record format:
5295 objcopy -I binary -O srec examples/image examples/image.srec
5297 The 'objcopy' does not understand the information in the U-Boot
5298 image header, so the resulting S-Record file will be relative to
5299 address 0x00000000. To load it to a given address, you need to
5300 specify the target address as 'offset' parameter with the 'loads'
5303 Example: install the image to address 0x40100000 (which on the
5304 TQM8xxL is in the first Flash bank):
5306 => erase 40100000 401FFFFF
5312 ## Ready for S-Record download ...
5313 ~>examples/image.srec
5314 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5316 15989 15990 15991 15992
5317 [file transfer complete]
5319 ## Start Addr = 0x00000000
5322 You can check the success of the download using the 'iminfo' command;
5323 this includes a checksum verification so you can be sure no data
5324 corruption happened:
5328 ## Checking Image at 40100000 ...
5329 Image Name: 2.2.13 for initrd on TQM850L
5330 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5331 Data Size: 335725 Bytes = 327 kB = 0 MB
5332 Load Address: 00000000
5333 Entry Point: 0000000c
5334 Verifying Checksum ... OK
5340 The "bootm" command is used to boot an application that is stored in
5341 memory (RAM or Flash). In case of a Linux kernel image, the contents
5342 of the "bootargs" environment variable is passed to the kernel as
5343 parameters. You can check and modify this variable using the
5344 "printenv" and "setenv" commands:
5347 => printenv bootargs
5348 bootargs=root=/dev/ram
5350 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5352 => printenv bootargs
5353 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5356 ## Booting Linux kernel at 40020000 ...
5357 Image Name: 2.2.13 for NFS on TQM850L
5358 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5359 Data Size: 381681 Bytes = 372 kB = 0 MB
5360 Load Address: 00000000
5361 Entry Point: 0000000c
5362 Verifying Checksum ... OK
5363 Uncompressing Kernel Image ... OK
5364 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
5365 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5366 time_init: decrementer frequency = 187500000/60
5367 Calibrating delay loop... 49.77 BogoMIPS
5368 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5371 If you want to boot a Linux kernel with initial RAM disk, you pass
5372 the memory addresses of both the kernel and the initrd image (PPBCOOT
5373 format!) to the "bootm" command:
5375 => imi 40100000 40200000
5377 ## Checking Image at 40100000 ...
5378 Image Name: 2.2.13 for initrd on TQM850L
5379 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5380 Data Size: 335725 Bytes = 327 kB = 0 MB
5381 Load Address: 00000000
5382 Entry Point: 0000000c
5383 Verifying Checksum ... OK
5385 ## Checking Image at 40200000 ...
5386 Image Name: Simple Ramdisk Image
5387 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5388 Data Size: 566530 Bytes = 553 kB = 0 MB
5389 Load Address: 00000000
5390 Entry Point: 00000000
5391 Verifying Checksum ... OK
5393 => bootm 40100000 40200000
5394 ## Booting Linux kernel at 40100000 ...
5395 Image Name: 2.2.13 for initrd on TQM850L
5396 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5397 Data Size: 335725 Bytes = 327 kB = 0 MB
5398 Load Address: 00000000
5399 Entry Point: 0000000c
5400 Verifying Checksum ... OK
5401 Uncompressing Kernel Image ... OK
5402 ## Loading RAMDisk Image at 40200000 ...
5403 Image Name: Simple Ramdisk Image
5404 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5405 Data Size: 566530 Bytes = 553 kB = 0 MB
5406 Load Address: 00000000
5407 Entry Point: 00000000
5408 Verifying Checksum ... OK
5409 Loading Ramdisk ... OK
5410 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
5411 Boot arguments: root=/dev/ram
5412 time_init: decrementer frequency = 187500000/60
5413 Calibrating delay loop... 49.77 BogoMIPS
5415 RAMDISK: Compressed image found at block 0
5416 VFS: Mounted root (ext2 filesystem).
5420 Boot Linux and pass a flat device tree:
5423 First, U-Boot must be compiled with the appropriate defines. See the section
5424 titled "Linux Kernel Interface" above for a more in depth explanation. The
5425 following is an example of how to start a kernel and pass an updated
5431 oft=oftrees/mpc8540ads.dtb
5432 => tftp $oftaddr $oft
5433 Speed: 1000, full duplex
5435 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5436 Filename 'oftrees/mpc8540ads.dtb'.
5437 Load address: 0x300000
5440 Bytes transferred = 4106 (100a hex)
5441 => tftp $loadaddr $bootfile
5442 Speed: 1000, full duplex
5444 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5446 Load address: 0x200000
5447 Loading:############
5449 Bytes transferred = 1029407 (fb51f hex)
5454 => bootm $loadaddr - $oftaddr
5455 ## Booting image at 00200000 ...
5456 Image Name: Linux-2.6.17-dirty
5457 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5458 Data Size: 1029343 Bytes = 1005.2 kB
5459 Load Address: 00000000
5460 Entry Point: 00000000
5461 Verifying Checksum ... OK
5462 Uncompressing Kernel Image ... OK
5463 Booting using flat device tree at 0x300000
5464 Using MPC85xx ADS machine description
5465 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5469 More About U-Boot Image Types:
5470 ------------------------------
5472 U-Boot supports the following image types:
5474 "Standalone Programs" are directly runnable in the environment
5475 provided by U-Boot; it is expected that (if they behave
5476 well) you can continue to work in U-Boot after return from
5477 the Standalone Program.
5478 "OS Kernel Images" are usually images of some Embedded OS which
5479 will take over control completely. Usually these programs
5480 will install their own set of exception handlers, device
5481 drivers, set up the MMU, etc. - this means, that you cannot
5482 expect to re-enter U-Boot except by resetting the CPU.
5483 "RAMDisk Images" are more or less just data blocks, and their
5484 parameters (address, size) are passed to an OS kernel that is
5486 "Multi-File Images" contain several images, typically an OS
5487 (Linux) kernel image and one or more data images like
5488 RAMDisks. This construct is useful for instance when you want
5489 to boot over the network using BOOTP etc., where the boot
5490 server provides just a single image file, but you want to get
5491 for instance an OS kernel and a RAMDisk image.
5493 "Multi-File Images" start with a list of image sizes, each
5494 image size (in bytes) specified by an "uint32_t" in network
5495 byte order. This list is terminated by an "(uint32_t)0".
5496 Immediately after the terminating 0 follow the images, one by
5497 one, all aligned on "uint32_t" boundaries (size rounded up to
5498 a multiple of 4 bytes).
5500 "Firmware Images" are binary images containing firmware (like
5501 U-Boot or FPGA images) which usually will be programmed to
5504 "Script files" are command sequences that will be executed by
5505 U-Boot's command interpreter; this feature is especially
5506 useful when you configure U-Boot to use a real shell (hush)
5507 as command interpreter.
5509 Booting the Linux zImage:
5510 -------------------------
5512 On some platforms, it's possible to boot Linux zImage. This is done
5513 using the "bootz" command. The syntax of "bootz" command is the same
5514 as the syntax of "bootm" command.
5516 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5517 kernel with raw initrd images. The syntax is slightly different, the
5518 address of the initrd must be augmented by it's size, in the following
5519 format: "<initrd addres>:<initrd size>".
5525 One of the features of U-Boot is that you can dynamically load and
5526 run "standalone" applications, which can use some resources of
5527 U-Boot like console I/O functions or interrupt services.
5529 Two simple examples are included with the sources:
5534 'examples/hello_world.c' contains a small "Hello World" Demo
5535 application; it is automatically compiled when you build U-Boot.
5536 It's configured to run at address 0x00040004, so you can play with it
5540 ## Ready for S-Record download ...
5541 ~>examples/hello_world.srec
5542 1 2 3 4 5 6 7 8 9 10 11 ...
5543 [file transfer complete]
5545 ## Start Addr = 0x00040004
5547 => go 40004 Hello World! This is a test.
5548 ## Starting application at 0x00040004 ...
5559 Hit any key to exit ...
5561 ## Application terminated, rc = 0x0
5563 Another example, which demonstrates how to register a CPM interrupt
5564 handler with the U-Boot code, can be found in 'examples/timer.c'.
5565 Here, a CPM timer is set up to generate an interrupt every second.
5566 The interrupt service routine is trivial, just printing a '.'
5567 character, but this is just a demo program. The application can be
5568 controlled by the following keys:
5570 ? - print current values og the CPM Timer registers
5571 b - enable interrupts and start timer
5572 e - stop timer and disable interrupts
5573 q - quit application
5576 ## Ready for S-Record download ...
5577 ~>examples/timer.srec
5578 1 2 3 4 5 6 7 8 9 10 11 ...
5579 [file transfer complete]
5581 ## Start Addr = 0x00040004
5584 ## Starting application at 0x00040004 ...
5587 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5590 [q, b, e, ?] Set interval 1000000 us
5593 [q, b, e, ?] ........
5594 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5597 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5600 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5603 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5605 [q, b, e, ?] ...Stopping timer
5607 [q, b, e, ?] ## Application terminated, rc = 0x0
5613 Over time, many people have reported problems when trying to use the
5614 "minicom" terminal emulation program for serial download. I (wd)
5615 consider minicom to be broken, and recommend not to use it. Under
5616 Unix, I recommend to use C-Kermit for general purpose use (and
5617 especially for kermit binary protocol download ("loadb" command), and
5618 use "cu" for S-Record download ("loads" command). See
5619 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5620 for help with kermit.
5623 Nevertheless, if you absolutely want to use it try adding this
5624 configuration to your "File transfer protocols" section:
5626 Name Program Name U/D FullScr IO-Red. Multi
5627 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5628 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5634 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5635 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5637 Building requires a cross environment; it is known to work on
5638 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5639 need gmake since the Makefiles are not compatible with BSD make).
5640 Note that the cross-powerpc package does not install include files;
5641 attempting to build U-Boot will fail because <machine/ansi.h> is
5642 missing. This file has to be installed and patched manually:
5644 # cd /usr/pkg/cross/powerpc-netbsd/include
5646 # ln -s powerpc machine
5647 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5648 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5650 Native builds *don't* work due to incompatibilities between native
5651 and U-Boot include files.
5653 Booting assumes that (the first part of) the image booted is a
5654 stage-2 loader which in turn loads and then invokes the kernel
5655 proper. Loader sources will eventually appear in the NetBSD source
5656 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5657 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5660 Implementation Internals:
5661 =========================
5663 The following is not intended to be a complete description of every
5664 implementation detail. However, it should help to understand the
5665 inner workings of U-Boot and make it easier to port it to custom
5669 Initial Stack, Global Data:
5670 ---------------------------
5672 The implementation of U-Boot is complicated by the fact that U-Boot
5673 starts running out of ROM (flash memory), usually without access to
5674 system RAM (because the memory controller is not initialized yet).
5675 This means that we don't have writable Data or BSS segments, and BSS
5676 is not initialized as zero. To be able to get a C environment working
5677 at all, we have to allocate at least a minimal stack. Implementation
5678 options for this are defined and restricted by the CPU used: Some CPU
5679 models provide on-chip memory (like the IMMR area on MPC8xx and
5680 MPC826x processors), on others (parts of) the data cache can be
5681 locked as (mis-) used as memory, etc.
5683 Chris Hallinan posted a good summary of these issues to the
5684 U-Boot mailing list:
5686 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5687 From: "Chris Hallinan" <clh@net1plus.com>
5688 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5691 Correct me if I'm wrong, folks, but the way I understand it
5692 is this: Using DCACHE as initial RAM for Stack, etc, does not
5693 require any physical RAM backing up the cache. The cleverness
5694 is that the cache is being used as a temporary supply of
5695 necessary storage before the SDRAM controller is setup. It's
5696 beyond the scope of this list to explain the details, but you
5697 can see how this works by studying the cache architecture and
5698 operation in the architecture and processor-specific manuals.
5700 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5701 is another option for the system designer to use as an
5702 initial stack/RAM area prior to SDRAM being available. Either
5703 option should work for you. Using CS 4 should be fine if your
5704 board designers haven't used it for something that would
5705 cause you grief during the initial boot! It is frequently not
5708 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5709 with your processor/board/system design. The default value
5710 you will find in any recent u-boot distribution in
5711 walnut.h should work for you. I'd set it to a value larger
5712 than your SDRAM module. If you have a 64MB SDRAM module, set
5713 it above 400_0000. Just make sure your board has no resources
5714 that are supposed to respond to that address! That code in
5715 start.S has been around a while and should work as is when
5716 you get the config right.
5721 It is essential to remember this, since it has some impact on the C
5722 code for the initialization procedures:
5724 * Initialized global data (data segment) is read-only. Do not attempt
5727 * Do not use any uninitialized global data (or implicitely initialized
5728 as zero data - BSS segment) at all - this is undefined, initiali-
5729 zation is performed later (when relocating to RAM).
5731 * Stack space is very limited. Avoid big data buffers or things like
5734 Having only the stack as writable memory limits means we cannot use
5735 normal global data to share information beween the code. But it
5736 turned out that the implementation of U-Boot can be greatly
5737 simplified by making a global data structure (gd_t) available to all
5738 functions. We could pass a pointer to this data as argument to _all_
5739 functions, but this would bloat the code. Instead we use a feature of
5740 the GCC compiler (Global Register Variables) to share the data: we
5741 place a pointer (gd) to the global data into a register which we
5742 reserve for this purpose.
5744 When choosing a register for such a purpose we are restricted by the
5745 relevant (E)ABI specifications for the current architecture, and by
5746 GCC's implementation.
5748 For PowerPC, the following registers have specific use:
5750 R2: reserved for system use
5751 R3-R4: parameter passing and return values
5752 R5-R10: parameter passing
5753 R13: small data area pointer
5757 (U-Boot also uses R12 as internal GOT pointer. r12
5758 is a volatile register so r12 needs to be reset when
5759 going back and forth between asm and C)
5761 ==> U-Boot will use R2 to hold a pointer to the global data
5763 Note: on PPC, we could use a static initializer (since the
5764 address of the global data structure is known at compile time),
5765 but it turned out that reserving a register results in somewhat
5766 smaller code - although the code savings are not that big (on
5767 average for all boards 752 bytes for the whole U-Boot image,
5768 624 text + 127 data).
5770 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5771 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5773 ==> U-Boot will use P3 to hold a pointer to the global data
5775 On ARM, the following registers are used:
5777 R0: function argument word/integer result
5778 R1-R3: function argument word
5779 R9: platform specific
5780 R10: stack limit (used only if stack checking is enabled)
5781 R11: argument (frame) pointer
5782 R12: temporary workspace
5785 R15: program counter
5787 ==> U-Boot will use R9 to hold a pointer to the global data
5789 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5791 On Nios II, the ABI is documented here:
5792 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5794 ==> U-Boot will use gp to hold a pointer to the global data
5796 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5797 to access small data sections, so gp is free.
5799 On NDS32, the following registers are used:
5801 R0-R1: argument/return
5803 R15: temporary register for assembler
5804 R16: trampoline register
5805 R28: frame pointer (FP)
5806 R29: global pointer (GP)
5807 R30: link register (LP)
5808 R31: stack pointer (SP)
5809 PC: program counter (PC)
5811 ==> U-Boot will use R10 to hold a pointer to the global data
5813 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5814 or current versions of GCC may "optimize" the code too much.
5819 U-Boot runs in system state and uses physical addresses, i.e. the
5820 MMU is not used either for address mapping nor for memory protection.
5822 The available memory is mapped to fixed addresses using the memory
5823 controller. In this process, a contiguous block is formed for each
5824 memory type (Flash, SDRAM, SRAM), even when it consists of several
5825 physical memory banks.
5827 U-Boot is installed in the first 128 kB of the first Flash bank (on
5828 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5829 booting and sizing and initializing DRAM, the code relocates itself
5830 to the upper end of DRAM. Immediately below the U-Boot code some
5831 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5832 configuration setting]. Below that, a structure with global Board
5833 Info data is placed, followed by the stack (growing downward).
5835 Additionally, some exception handler code is copied to the low 8 kB
5836 of DRAM (0x00000000 ... 0x00001FFF).
5838 So a typical memory configuration with 16 MB of DRAM could look like
5841 0x0000 0000 Exception Vector code
5844 0x0000 2000 Free for Application Use
5850 0x00FB FF20 Monitor Stack (Growing downward)
5851 0x00FB FFAC Board Info Data and permanent copy of global data
5852 0x00FC 0000 Malloc Arena
5855 0x00FE 0000 RAM Copy of Monitor Code
5856 ... eventually: LCD or video framebuffer
5857 ... eventually: pRAM (Protected RAM - unchanged by reset)
5858 0x00FF FFFF [End of RAM]
5861 System Initialization:
5862 ----------------------
5864 In the reset configuration, U-Boot starts at the reset entry point
5865 (on most PowerPC systems at address 0x00000100). Because of the reset
5866 configuration for CS0# this is a mirror of the onboard Flash memory.
5867 To be able to re-map memory U-Boot then jumps to its link address.
5868 To be able to implement the initialization code in C, a (small!)
5869 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5870 which provide such a feature like MPC8xx or MPC8260), or in a locked
5871 part of the data cache. After that, U-Boot initializes the CPU core,
5872 the caches and the SIU.
5874 Next, all (potentially) available memory banks are mapped using a
5875 preliminary mapping. For example, we put them on 512 MB boundaries
5876 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5877 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5878 programmed for SDRAM access. Using the temporary configuration, a
5879 simple memory test is run that determines the size of the SDRAM
5882 When there is more than one SDRAM bank, and the banks are of
5883 different size, the largest is mapped first. For equal size, the first
5884 bank (CS2#) is mapped first. The first mapping is always for address
5885 0x00000000, with any additional banks following immediately to create
5886 contiguous memory starting from 0.
5888 Then, the monitor installs itself at the upper end of the SDRAM area
5889 and allocates memory for use by malloc() and for the global Board
5890 Info data; also, the exception vector code is copied to the low RAM
5891 pages, and the final stack is set up.
5893 Only after this relocation will you have a "normal" C environment;
5894 until that you are restricted in several ways, mostly because you are
5895 running from ROM, and because the code will have to be relocated to a
5899 U-Boot Porting Guide:
5900 ----------------------
5902 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5906 int main(int argc, char *argv[])
5908 sighandler_t no_more_time;
5910 signal(SIGALRM, no_more_time);
5911 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5913 if (available_money > available_manpower) {
5914 Pay consultant to port U-Boot;
5918 Download latest U-Boot source;
5920 Subscribe to u-boot mailing list;
5923 email("Hi, I am new to U-Boot, how do I get started?");
5926 Read the README file in the top level directory;
5927 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5928 Read applicable doc/*.README;
5929 Read the source, Luke;
5930 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5933 if (available_money > toLocalCurrency ($2500))
5936 Add a lot of aggravation and time;
5938 if (a similar board exists) { /* hopefully... */
5939 cp -a board/<similar> board/<myboard>
5940 cp include/configs/<similar>.h include/configs/<myboard>.h
5942 Create your own board support subdirectory;
5943 Create your own board include/configs/<myboard>.h file;
5945 Edit new board/<myboard> files
5946 Edit new include/configs/<myboard>.h
5951 Add / modify source code;
5955 email("Hi, I am having problems...");
5957 Send patch file to the U-Boot email list;
5958 if (reasonable critiques)
5959 Incorporate improvements from email list code review;
5961 Defend code as written;
5967 void no_more_time (int sig)
5976 All contributions to U-Boot should conform to the Linux kernel
5977 coding style; see the file "Documentation/CodingStyle" and the script
5978 "scripts/Lindent" in your Linux kernel source directory.
5980 Source files originating from a different project (for example the
5981 MTD subsystem) are generally exempt from these guidelines and are not
5982 reformated to ease subsequent migration to newer versions of those
5985 Please note that U-Boot is implemented in C (and to some small parts in
5986 Assembler); no C++ is used, so please do not use C++ style comments (//)
5989 Please also stick to the following formatting rules:
5990 - remove any trailing white space
5991 - use TAB characters for indentation and vertical alignment, not spaces
5992 - make sure NOT to use DOS '\r\n' line feeds
5993 - do not add more than 2 consecutive empty lines to source files
5994 - do not add trailing empty lines to source files
5996 Submissions which do not conform to the standards may be returned
5997 with a request to reformat the changes.
6003 Since the number of patches for U-Boot is growing, we need to
6004 establish some rules. Submissions which do not conform to these rules
6005 may be rejected, even when they contain important and valuable stuff.
6007 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6009 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6010 see http://lists.denx.de/mailman/listinfo/u-boot
6012 When you send a patch, please include the following information with
6015 * For bug fixes: a description of the bug and how your patch fixes
6016 this bug. Please try to include a way of demonstrating that the
6017 patch actually fixes something.
6019 * For new features: a description of the feature and your
6022 * A CHANGELOG entry as plaintext (separate from the patch)
6024 * For major contributions, your entry to the CREDITS file
6026 * When you add support for a new board, don't forget to add a
6027 maintainer e-mail address to the boards.cfg file, too.
6029 * If your patch adds new configuration options, don't forget to
6030 document these in the README file.
6032 * The patch itself. If you are using git (which is *strongly*
6033 recommended) you can easily generate the patch using the
6034 "git format-patch". If you then use "git send-email" to send it to
6035 the U-Boot mailing list, you will avoid most of the common problems
6036 with some other mail clients.
6038 If you cannot use git, use "diff -purN OLD NEW". If your version of
6039 diff does not support these options, then get the latest version of
6042 The current directory when running this command shall be the parent
6043 directory of the U-Boot source tree (i. e. please make sure that
6044 your patch includes sufficient directory information for the
6047 We prefer patches as plain text. MIME attachments are discouraged,
6048 and compressed attachments must not be used.
6050 * If one logical set of modifications affects or creates several
6051 files, all these changes shall be submitted in a SINGLE patch file.
6053 * Changesets that contain different, unrelated modifications shall be
6054 submitted as SEPARATE patches, one patch per changeset.
6059 * Before sending the patch, run the MAKEALL script on your patched
6060 source tree and make sure that no errors or warnings are reported
6061 for any of the boards.
6063 * Keep your modifications to the necessary minimum: A patch
6064 containing several unrelated changes or arbitrary reformats will be
6065 returned with a request to re-formatting / split it.
6067 * If you modify existing code, make sure that your new code does not
6068 add to the memory footprint of the code ;-) Small is beautiful!
6069 When adding new features, these should compile conditionally only
6070 (using #ifdef), and the resulting code with the new feature
6071 disabled must not need more memory than the old code without your
6074 * Remember that there is a size limit of 100 kB per message on the
6075 u-boot mailing list. Bigger patches will be moderated. If they are
6076 reasonable and not too big, they will be acknowledged. But patches
6077 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob