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_CONSOLE coninfo
900 CONFIG_CMD_CRC32 * crc32
901 CONFIG_CMD_DATE * support for RTC, date/time...
902 CONFIG_CMD_DHCP * DHCP support
903 CONFIG_CMD_DIAG * Diagnostics
904 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
905 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
906 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
907 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
908 CONFIG_CMD_DTT * Digital Therm and Thermostat
909 CONFIG_CMD_ECHO echo arguments
910 CONFIG_CMD_EDITENV edit env variable
911 CONFIG_CMD_EEPROM * EEPROM read/write support
912 CONFIG_CMD_ELF * bootelf, bootvx
913 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
914 CONFIG_CMD_ENV_FLAGS * display details about env flags
915 CONFIG_CMD_ENV_EXISTS * check existence of env variable
916 CONFIG_CMD_EXPORTENV * export the environment
917 CONFIG_CMD_EXT2 * ext2 command support
918 CONFIG_CMD_EXT4 * ext4 command support
919 CONFIG_CMD_SAVEENV saveenv
920 CONFIG_CMD_FDC * Floppy Disk Support
921 CONFIG_CMD_FAT * FAT command support
922 CONFIG_CMD_FDOS * Dos diskette Support
923 CONFIG_CMD_FLASH flinfo, erase, protect
924 CONFIG_CMD_FPGA FPGA device initialization support
925 CONFIG_CMD_FUSE * Device fuse support
926 CONFIG_CMD_GETTIME * Get time since boot
927 CONFIG_CMD_GO * the 'go' command (exec code)
928 CONFIG_CMD_GREPENV * search environment
929 CONFIG_CMD_HASH * calculate hash / digest
930 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
931 CONFIG_CMD_I2C * I2C serial bus support
932 CONFIG_CMD_IDE * IDE harddisk support
933 CONFIG_CMD_IMI iminfo
934 CONFIG_CMD_IMLS List all images found in NOR flash
935 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
936 CONFIG_CMD_IMMAP * IMMR dump support
937 CONFIG_CMD_IMPORTENV * import an environment
938 CONFIG_CMD_INI * import data from an ini file into the env
939 CONFIG_CMD_IRQ * irqinfo
940 CONFIG_CMD_ITEST Integer/string test of 2 values
941 CONFIG_CMD_JFFS2 * JFFS2 Support
942 CONFIG_CMD_KGDB * kgdb
943 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
944 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
946 CONFIG_CMD_LOADB loadb
947 CONFIG_CMD_LOADS loads
948 CONFIG_CMD_MD5SUM * print md5 message digest
949 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
950 CONFIG_CMD_MEMINFO * Display detailed memory information
951 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
953 CONFIG_CMD_MEMTEST * mtest
954 CONFIG_CMD_MISC Misc functions like sleep etc
955 CONFIG_CMD_MMC * MMC memory mapped support
956 CONFIG_CMD_MII * MII utility commands
957 CONFIG_CMD_MTDPARTS * MTD partition support
958 CONFIG_CMD_NAND * NAND support
959 CONFIG_CMD_NET bootp, tftpboot, rarpboot
960 CONFIG_CMD_NFS NFS support
961 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
962 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
963 CONFIG_CMD_PCI * pciinfo
964 CONFIG_CMD_PCMCIA * PCMCIA support
965 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
967 CONFIG_CMD_PORTIO * Port I/O
968 CONFIG_CMD_READ * Read raw data from partition
969 CONFIG_CMD_REGINFO * Register dump
970 CONFIG_CMD_RUN run command in env variable
971 CONFIG_CMD_SANDBOX * sb command to access sandbox features
972 CONFIG_CMD_SAVES * save S record dump
973 CONFIG_CMD_SCSI * SCSI Support
974 CONFIG_CMD_SDRAM * print SDRAM configuration information
975 (requires CONFIG_CMD_I2C)
976 CONFIG_CMD_SETGETDCR Support for DCR Register access
978 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
979 CONFIG_CMD_SHA1SUM * print sha1 memory digest
980 (requires CONFIG_CMD_MEMORY)
981 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
982 CONFIG_CMD_SOURCE "source" command Support
983 CONFIG_CMD_SPI * SPI serial bus support
984 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
985 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
986 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
987 CONFIG_CMD_TIMER * access to the system tick timer
988 CONFIG_CMD_USB * USB support
989 CONFIG_CMD_CDP * Cisco Discover Protocol support
990 CONFIG_CMD_MFSL * Microblaze FSL support
991 CONFIG_CMD_XIMG Load part of Multi Image
994 EXAMPLE: If you want all functions except of network
995 support you can write:
997 #include "config_cmd_all.h"
998 #undef CONFIG_CMD_NET
1001 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1003 Note: Don't enable the "icache" and "dcache" commands
1004 (configuration option CONFIG_CMD_CACHE) unless you know
1005 what you (and your U-Boot users) are doing. Data
1006 cache cannot be enabled on systems like the 8xx or
1007 8260 (where accesses to the IMMR region must be
1008 uncached), and it cannot be disabled on all other
1009 systems where we (mis-) use the data cache to hold an
1010 initial stack and some data.
1013 XXX - this list needs to get updated!
1015 - Regular expression support:
1017 If this variable is defined, U-Boot is linked against
1018 the SLRE (Super Light Regular Expression) library,
1019 which adds regex support to some commands, as for
1020 example "env grep" and "setexpr".
1024 If this variable is defined, U-Boot will use a device tree
1025 to configure its devices, instead of relying on statically
1026 compiled #defines in the board file. This option is
1027 experimental and only available on a few boards. The device
1028 tree is available in the global data as gd->fdt_blob.
1030 U-Boot needs to get its device tree from somewhere. This can
1031 be done using one of the two options below:
1034 If this variable is defined, U-Boot will embed a device tree
1035 binary in its image. This device tree file should be in the
1036 board directory and called <soc>-<board>.dts. The binary file
1037 is then picked up in board_init_f() and made available through
1038 the global data structure as gd->blob.
1041 If this variable is defined, U-Boot will build a device tree
1042 binary. It will be called u-boot.dtb. Architecture-specific
1043 code will locate it at run-time. Generally this works by:
1045 cat u-boot.bin u-boot.dtb >image.bin
1047 and in fact, U-Boot does this for you, creating a file called
1048 u-boot-dtb.bin which is useful in the common case. You can
1049 still use the individual files if you need something more
1054 If this variable is defined, it enables watchdog
1055 support for the SoC. There must be support in the SoC
1056 specific code for a watchdog. For the 8xx and 8260
1057 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1058 register. When supported for a specific SoC is
1059 available, then no further board specific code should
1060 be needed to use it.
1063 When using a watchdog circuitry external to the used
1064 SoC, then define this variable and provide board
1065 specific code for the "hw_watchdog_reset" function.
1068 CONFIG_VERSION_VARIABLE
1069 If this variable is defined, an environment variable
1070 named "ver" is created by U-Boot showing the U-Boot
1071 version as printed by the "version" command.
1072 Any change to this variable will be reverted at the
1077 When CONFIG_CMD_DATE is selected, the type of the RTC
1078 has to be selected, too. Define exactly one of the
1081 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1082 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1083 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1084 CONFIG_RTC_MC146818 - use MC146818 RTC
1085 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1086 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1087 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1088 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1089 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1090 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1091 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1092 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1095 Note that if the RTC uses I2C, then the I2C interface
1096 must also be configured. See I2C Support, below.
1099 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1101 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1102 chip-ngpio pairs that tell the PCA953X driver the number of
1103 pins supported by a particular chip.
1105 Note that if the GPIO device uses I2C, then the I2C interface
1106 must also be configured. See I2C Support, below.
1108 - Timestamp Support:
1110 When CONFIG_TIMESTAMP is selected, the timestamp
1111 (date and time) of an image is printed by image
1112 commands like bootm or iminfo. This option is
1113 automatically enabled when you select CONFIG_CMD_DATE .
1115 - Partition Labels (disklabels) Supported:
1116 Zero or more of the following:
1117 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1118 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1119 Intel architecture, USB sticks, etc.
1120 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1121 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1122 bootloader. Note 2TB partition limit; see
1124 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1126 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1127 CONFIG_CMD_SCSI) you must configure support for at
1128 least one non-MTD partition type as well.
1131 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1132 board configurations files but used nowhere!
1134 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1135 be performed by calling the function
1136 ide_set_reset(int reset)
1137 which has to be defined in a board specific file
1142 Set this to enable ATAPI support.
1147 Set this to enable support for disks larger than 137GB
1148 Also look at CONFIG_SYS_64BIT_LBA.
1149 Whithout these , LBA48 support uses 32bit variables and will 'only'
1150 support disks up to 2.1TB.
1152 CONFIG_SYS_64BIT_LBA:
1153 When enabled, makes the IDE subsystem use 64bit sector addresses.
1157 At the moment only there is only support for the
1158 SYM53C8XX SCSI controller; define
1159 CONFIG_SCSI_SYM53C8XX to enable it.
1161 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1162 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1163 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1164 maximum numbers of LUNs, SCSI ID's and target
1166 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1168 The environment variable 'scsidevs' is set to the number of
1169 SCSI devices found during the last scan.
1171 - NETWORK Support (PCI):
1173 Support for Intel 8254x/8257x gigabit chips.
1176 Utility code for direct access to the SPI bus on Intel 8257x.
1177 This does not do anything useful unless you set at least one
1178 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1180 CONFIG_E1000_SPI_GENERIC
1181 Allow generic access to the SPI bus on the Intel 8257x, for
1182 example with the "sspi" command.
1185 Management command for E1000 devices. When used on devices
1186 with SPI support you can reprogram the EEPROM from U-Boot.
1188 CONFIG_E1000_FALLBACK_MAC
1189 default MAC for empty EEPROM after production.
1192 Support for Intel 82557/82559/82559ER chips.
1193 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1194 write routine for first time initialisation.
1197 Support for Digital 2114x chips.
1198 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1199 modem chip initialisation (KS8761/QS6611).
1202 Support for National dp83815 chips.
1205 Support for National dp8382[01] gigabit chips.
1207 - NETWORK Support (other):
1209 CONFIG_DRIVER_AT91EMAC
1210 Support for AT91RM9200 EMAC.
1213 Define this to use reduced MII inteface
1215 CONFIG_DRIVER_AT91EMAC_QUIET
1216 If this defined, the driver is quiet.
1217 The driver doen't show link status messages.
1219 CONFIG_CALXEDA_XGMAC
1220 Support for the Calxeda XGMAC device
1223 Support for SMSC's LAN91C96 chips.
1225 CONFIG_LAN91C96_BASE
1226 Define this to hold the physical address
1227 of the LAN91C96's I/O space
1229 CONFIG_LAN91C96_USE_32_BIT
1230 Define this to enable 32 bit addressing
1233 Support for SMSC's LAN91C111 chip
1235 CONFIG_SMC91111_BASE
1236 Define this to hold the physical address
1237 of the device (I/O space)
1239 CONFIG_SMC_USE_32_BIT
1240 Define this if data bus is 32 bits
1242 CONFIG_SMC_USE_IOFUNCS
1243 Define this to use i/o functions instead of macros
1244 (some hardware wont work with macros)
1246 CONFIG_DRIVER_TI_EMAC
1247 Support for davinci emac
1249 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1250 Define this if you have more then 3 PHYs.
1253 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1255 CONFIG_FTGMAC100_EGIGA
1256 Define this to use GE link update with gigabit PHY.
1257 Define this if FTGMAC100 is connected to gigabit PHY.
1258 If your system has 10/100 PHY only, it might not occur
1259 wrong behavior. Because PHY usually return timeout or
1260 useless data when polling gigabit status and gigabit
1261 control registers. This behavior won't affect the
1262 correctnessof 10/100 link speed update.
1265 Support for SMSC's LAN911x and LAN921x chips
1268 Define this to hold the physical address
1269 of the device (I/O space)
1271 CONFIG_SMC911X_32_BIT
1272 Define this if data bus is 32 bits
1274 CONFIG_SMC911X_16_BIT
1275 Define this if data bus is 16 bits. If your processor
1276 automatically converts one 32 bit word to two 16 bit
1277 words you may also try CONFIG_SMC911X_32_BIT.
1280 Support for Renesas on-chip Ethernet controller
1282 CONFIG_SH_ETHER_USE_PORT
1283 Define the number of ports to be used
1285 CONFIG_SH_ETHER_PHY_ADDR
1286 Define the ETH PHY's address
1288 CONFIG_SH_ETHER_CACHE_WRITEBACK
1289 If this option is set, the driver enables cache flush.
1293 Support TPM devices.
1296 Support for i2c bus TPM devices. Only one device
1297 per system is supported at this time.
1299 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1300 Define the the i2c bus number for the TPM device
1302 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1303 Define the TPM's address on the i2c bus
1305 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1306 Define the burst count bytes upper limit
1308 CONFIG_TPM_ATMEL_TWI
1309 Support for Atmel TWI TPM device. Requires I2C support.
1312 Support for generic parallel port TPM devices. Only one device
1313 per system is supported at this time.
1315 CONFIG_TPM_TIS_BASE_ADDRESS
1316 Base address where the generic TPM device is mapped
1317 to. Contemporary x86 systems usually map it at
1321 Add tpm monitor functions.
1322 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1323 provides monitor access to authorized functions.
1326 Define this to enable the TPM support library which provides
1327 functional interfaces to some TPM commands.
1328 Requires support for a TPM device.
1330 CONFIG_TPM_AUTH_SESSIONS
1331 Define this to enable authorized functions in the TPM library.
1332 Requires CONFIG_TPM and CONFIG_SHA1.
1335 At the moment only the UHCI host controller is
1336 supported (PIP405, MIP405, MPC5200); define
1337 CONFIG_USB_UHCI to enable it.
1338 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1339 and define CONFIG_USB_STORAGE to enable the USB
1342 Supported are USB Keyboards and USB Floppy drives
1344 MPC5200 USB requires additional defines:
1346 for 528 MHz Clock: 0x0001bbbb
1350 for differential drivers: 0x00001000
1351 for single ended drivers: 0x00005000
1352 for differential drivers on PSC3: 0x00000100
1353 for single ended drivers on PSC3: 0x00004100
1354 CONFIG_SYS_USB_EVENT_POLL
1355 May be defined to allow interrupt polling
1356 instead of using asynchronous interrupts
1358 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1359 txfilltuning field in the EHCI controller on reset.
1361 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1362 interval for usb hub power-on delay.(minimum 100msec)
1365 Define the below if you wish to use the USB console.
1366 Once firmware is rebuilt from a serial console issue the
1367 command "setenv stdin usbtty; setenv stdout usbtty" and
1368 attach your USB cable. The Unix command "dmesg" should print
1369 it has found a new device. The environment variable usbtty
1370 can be set to gserial or cdc_acm to enable your device to
1371 appear to a USB host as a Linux gserial device or a
1372 Common Device Class Abstract Control Model serial device.
1373 If you select usbtty = gserial you should be able to enumerate
1375 # modprobe usbserial vendor=0xVendorID product=0xProductID
1376 else if using cdc_acm, simply setting the environment
1377 variable usbtty to be cdc_acm should suffice. The following
1378 might be defined in YourBoardName.h
1381 Define this to build a UDC device
1384 Define this to have a tty type of device available to
1385 talk to the UDC device
1388 Define this to enable the high speed support for usb
1389 device and usbtty. If this feature is enabled, a routine
1390 int is_usbd_high_speed(void)
1391 also needs to be defined by the driver to dynamically poll
1392 whether the enumeration has succeded at high speed or full
1395 CONFIG_SYS_CONSOLE_IS_IN_ENV
1396 Define this if you want stdin, stdout &/or stderr to
1400 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1401 Derive USB clock from external clock "blah"
1402 - CONFIG_SYS_USB_EXTC_CLK 0x02
1404 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1405 Derive USB clock from brgclk
1406 - CONFIG_SYS_USB_BRG_CLK 0x04
1408 If you have a USB-IF assigned VendorID then you may wish to
1409 define your own vendor specific values either in BoardName.h
1410 or directly in usbd_vendor_info.h. If you don't define
1411 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1412 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1413 should pretend to be a Linux device to it's target host.
1415 CONFIG_USBD_MANUFACTURER
1416 Define this string as the name of your company for
1417 - CONFIG_USBD_MANUFACTURER "my company"
1419 CONFIG_USBD_PRODUCT_NAME
1420 Define this string as the name of your product
1421 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1423 CONFIG_USBD_VENDORID
1424 Define this as your assigned Vendor ID from the USB
1425 Implementors Forum. This *must* be a genuine Vendor ID
1426 to avoid polluting the USB namespace.
1427 - CONFIG_USBD_VENDORID 0xFFFF
1429 CONFIG_USBD_PRODUCTID
1430 Define this as the unique Product ID
1432 - CONFIG_USBD_PRODUCTID 0xFFFF
1434 Some USB device drivers may need to check USB cable attachment.
1435 In this case you can enable following config in BoardName.h:
1436 CONFIG_USB_CABLE_CHECK
1437 This enables function definition:
1438 - usb_cable_connected() in include/usb.h
1439 Implementation of this function is board-specific.
1441 - ULPI Layer Support:
1442 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1443 the generic ULPI layer. The generic layer accesses the ULPI PHY
1444 via the platform viewport, so you need both the genric layer and
1445 the viewport enabled. Currently only Chipidea/ARC based
1446 viewport is supported.
1447 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1448 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1449 If your ULPI phy needs a different reference clock than the
1450 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1451 the appropriate value in Hz.
1454 The MMC controller on the Intel PXA is supported. To
1455 enable this define CONFIG_MMC. The MMC can be
1456 accessed from the boot prompt by mapping the device
1457 to physical memory similar to flash. Command line is
1458 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1459 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1462 Support for Renesas on-chip MMCIF controller
1464 CONFIG_SH_MMCIF_ADDR
1465 Define the base address of MMCIF registers
1468 Define the clock frequency for MMCIF
1470 - USB Device Firmware Update (DFU) class support:
1472 This enables the USB portion of the DFU USB class
1475 This enables the command "dfu" which is used to have
1476 U-Boot create a DFU class device via USB. This command
1477 requires that the "dfu_alt_info" environment variable be
1478 set and define the alt settings to expose to the host.
1481 This enables support for exposing (e)MMC devices via DFU.
1484 This enables support for exposing NAND devices via DFU.
1487 This enables support for exposing RAM via DFU.
1488 Note: DFU spec refer to non-volatile memory usage, but
1489 allow usages beyond the scope of spec - here RAM usage,
1490 one that would help mostly the developer.
1492 CONFIG_SYS_DFU_DATA_BUF_SIZE
1493 Dfu transfer uses a buffer before writing data to the
1494 raw storage device. Make the size (in bytes) of this buffer
1495 configurable. The size of this buffer is also configurable
1496 through the "dfu_bufsiz" environment variable.
1498 CONFIG_SYS_DFU_MAX_FILE_SIZE
1499 When updating files rather than the raw storage device,
1500 we use a static buffer to copy the file into and then write
1501 the buffer once we've been given the whole file. Define
1502 this to the maximum filesize (in bytes) for the buffer.
1503 Default is 4 MiB if undefined.
1505 - Journaling Flash filesystem support:
1506 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1507 CONFIG_JFFS2_NAND_DEV
1508 Define these for a default partition on a NAND device
1510 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1511 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1512 Define these for a default partition on a NOR device
1514 CONFIG_SYS_JFFS_CUSTOM_PART
1515 Define this to create an own partition. You have to provide a
1516 function struct part_info* jffs2_part_info(int part_num)
1518 If you define only one JFFS2 partition you may also want to
1519 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1520 to disable the command chpart. This is the default when you
1521 have not defined a custom partition
1523 - FAT(File Allocation Table) filesystem write function support:
1526 Define this to enable support for saving memory data as a
1527 file in FAT formatted partition.
1529 This will also enable the command "fatwrite" enabling the
1530 user to write files to FAT.
1532 CBFS (Coreboot Filesystem) support
1535 Define this to enable support for reading from a Coreboot
1536 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1542 Define this to enable standard (PC-Style) keyboard
1546 Standard PC keyboard driver with US (is default) and
1547 GERMAN key layout (switch via environment 'keymap=de') support.
1548 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1549 for cfb_console. Supports cursor blinking.
1552 Enables a Chrome OS keyboard using the CROS_EC interface.
1553 This uses CROS_EC to communicate with a second microcontroller
1554 which provides key scans on request.
1559 Define this to enable video support (for output to
1562 CONFIG_VIDEO_CT69000
1564 Enable Chips & Technologies 69000 Video chip
1566 CONFIG_VIDEO_SMI_LYNXEM
1567 Enable Silicon Motion SMI 712/710/810 Video chip. The
1568 video output is selected via environment 'videoout'
1569 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1572 For the CT69000 and SMI_LYNXEM drivers, videomode is
1573 selected via environment 'videomode'. Two different ways
1575 - "videomode=num" 'num' is a standard LiLo mode numbers.
1576 Following standard modes are supported (* is default):
1578 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1579 -------------+---------------------------------------------
1580 8 bits | 0x301* 0x303 0x305 0x161 0x307
1581 15 bits | 0x310 0x313 0x316 0x162 0x319
1582 16 bits | 0x311 0x314 0x317 0x163 0x31A
1583 24 bits | 0x312 0x315 0x318 ? 0x31B
1584 -------------+---------------------------------------------
1585 (i.e. setenv videomode 317; saveenv; reset;)
1587 - "videomode=bootargs" all the video parameters are parsed
1588 from the bootargs. (See drivers/video/videomodes.c)
1591 CONFIG_VIDEO_SED13806
1592 Enable Epson SED13806 driver. This driver supports 8bpp
1593 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1594 or CONFIG_VIDEO_SED13806_16BPP
1597 Enable the Freescale DIU video driver. Reference boards for
1598 SOCs that have a DIU should define this macro to enable DIU
1599 support, and should also define these other macros:
1605 CONFIG_VIDEO_SW_CURSOR
1606 CONFIG_VGA_AS_SINGLE_DEVICE
1608 CONFIG_VIDEO_BMP_LOGO
1610 The DIU driver will look for the 'video-mode' environment
1611 variable, and if defined, enable the DIU as a console during
1612 boot. See the documentation file README.video for a
1613 description of this variable.
1617 Enable the VGA video / BIOS for x86. The alternative if you
1618 are using coreboot is to use the coreboot frame buffer
1625 Define this to enable a custom keyboard support.
1626 This simply calls drv_keyboard_init() which must be
1627 defined in your board-specific files.
1628 The only board using this so far is RBC823.
1630 - LCD Support: CONFIG_LCD
1632 Define this to enable LCD support (for output to LCD
1633 display); also select one of the supported displays
1634 by defining one of these:
1638 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1640 CONFIG_NEC_NL6448AC33:
1642 NEC NL6448AC33-18. Active, color, single scan.
1644 CONFIG_NEC_NL6448BC20
1646 NEC NL6448BC20-08. 6.5", 640x480.
1647 Active, color, single scan.
1649 CONFIG_NEC_NL6448BC33_54
1651 NEC NL6448BC33-54. 10.4", 640x480.
1652 Active, color, single scan.
1656 Sharp 320x240. Active, color, single scan.
1657 It isn't 16x9, and I am not sure what it is.
1659 CONFIG_SHARP_LQ64D341
1661 Sharp LQ64D341 display, 640x480.
1662 Active, color, single scan.
1666 HLD1045 display, 640x480.
1667 Active, color, single scan.
1671 Optrex CBL50840-2 NF-FW 99 22 M5
1673 Hitachi LMG6912RPFC-00T
1677 320x240. Black & white.
1679 Normally display is black on white background; define
1680 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1682 CONFIG_LCD_ALIGNMENT
1684 Normally the LCD is page-aligned (tyically 4KB). If this is
1685 defined then the LCD will be aligned to this value instead.
1686 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1687 here, since it is cheaper to change data cache settings on
1688 a per-section basis.
1690 CONFIG_CONSOLE_SCROLL_LINES
1692 When the console need to be scrolled, this is the number of
1693 lines to scroll by. It defaults to 1. Increasing this makes
1694 the console jump but can help speed up operation when scrolling
1699 Support drawing of RLE8-compressed bitmaps on the LCD.
1703 Enables an 'i2c edid' command which can read EDID
1704 information over I2C from an attached LCD display.
1706 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1708 If this option is set, the environment is checked for
1709 a variable "splashimage". If found, the usual display
1710 of logo, copyright and system information on the LCD
1711 is suppressed and the BMP image at the address
1712 specified in "splashimage" is loaded instead. The
1713 console is redirected to the "nulldev", too. This
1714 allows for a "silent" boot where a splash screen is
1715 loaded very quickly after power-on.
1717 CONFIG_SPLASHIMAGE_GUARD
1719 If this option is set, then U-Boot will prevent the environment
1720 variable "splashimage" from being set to a problematic address
1721 (see README.displaying-bmps and README.arm-unaligned-accesses).
1722 This option is useful for targets where, due to alignment
1723 restrictions, an improperly aligned BMP image will cause a data
1724 abort. If you think you will not have problems with unaligned
1725 accesses (for example because your toolchain prevents them)
1726 there is no need to set this option.
1728 CONFIG_SPLASH_SCREEN_ALIGN
1730 If this option is set the splash image can be freely positioned
1731 on the screen. Environment variable "splashpos" specifies the
1732 position as "x,y". If a positive number is given it is used as
1733 number of pixel from left/top. If a negative number is given it
1734 is used as number of pixel from right/bottom. You can also
1735 specify 'm' for centering the image.
1738 setenv splashpos m,m
1739 => image at center of screen
1741 setenv splashpos 30,20
1742 => image at x = 30 and y = 20
1744 setenv splashpos -10,m
1745 => vertically centered image
1746 at x = dspWidth - bmpWidth - 9
1748 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1750 If this option is set, additionally to standard BMP
1751 images, gzipped BMP images can be displayed via the
1752 splashscreen support or the bmp command.
1754 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1756 If this option is set, 8-bit RLE compressed BMP images
1757 can be displayed via the splashscreen support or the
1760 - Do compresssing for memory range:
1763 If this option is set, it would use zlib deflate method
1764 to compress the specified memory at its best effort.
1766 - Compression support:
1769 Enabled by default to support gzip compressed images.
1773 If this option is set, support for bzip2 compressed
1774 images is included. If not, only uncompressed and gzip
1775 compressed images are supported.
1777 NOTE: the bzip2 algorithm requires a lot of RAM, so
1778 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1783 If this option is set, support for lzma compressed
1786 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1787 requires an amount of dynamic memory that is given by the
1790 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1792 Where lc and lp stand for, respectively, Literal context bits
1793 and Literal pos bits.
1795 This value is upper-bounded by 14MB in the worst case. Anyway,
1796 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1797 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1798 a very small buffer.
1800 Use the lzmainfo tool to determinate the lc and lp values and
1801 then calculate the amount of needed dynamic memory (ensuring
1802 the appropriate CONFIG_SYS_MALLOC_LEN value).
1806 If this option is set, support for LZO compressed images
1812 The address of PHY on MII bus.
1814 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1816 The clock frequency of the MII bus
1820 If this option is set, support for speed/duplex
1821 detection of gigabit PHY is included.
1823 CONFIG_PHY_RESET_DELAY
1825 Some PHY like Intel LXT971A need extra delay after
1826 reset before any MII register access is possible.
1827 For such PHY, set this option to the usec delay
1828 required. (minimum 300usec for LXT971A)
1830 CONFIG_PHY_CMD_DELAY (ppc4xx)
1832 Some PHY like Intel LXT971A need extra delay after
1833 command issued before MII status register can be read
1843 Define a default value for Ethernet address to use
1844 for the respective Ethernet interface, in case this
1845 is not determined automatically.
1850 Define a default value for the IP address to use for
1851 the default Ethernet interface, in case this is not
1852 determined through e.g. bootp.
1853 (Environment variable "ipaddr")
1855 - Server IP address:
1858 Defines a default value for the IP address of a TFTP
1859 server to contact when using the "tftboot" command.
1860 (Environment variable "serverip")
1862 CONFIG_KEEP_SERVERADDR
1864 Keeps the server's MAC address, in the env 'serveraddr'
1865 for passing to bootargs (like Linux's netconsole option)
1867 - Gateway IP address:
1870 Defines a default value for the IP address of the
1871 default router where packets to other networks are
1873 (Environment variable "gatewayip")
1878 Defines a default value for the subnet mask (or
1879 routing prefix) which is used to determine if an IP
1880 address belongs to the local subnet or needs to be
1881 forwarded through a router.
1882 (Environment variable "netmask")
1884 - Multicast TFTP Mode:
1887 Defines whether you want to support multicast TFTP as per
1888 rfc-2090; for example to work with atftp. Lets lots of targets
1889 tftp down the same boot image concurrently. Note: the Ethernet
1890 driver in use must provide a function: mcast() to join/leave a
1893 - BOOTP Recovery Mode:
1894 CONFIG_BOOTP_RANDOM_DELAY
1896 If you have many targets in a network that try to
1897 boot using BOOTP, you may want to avoid that all
1898 systems send out BOOTP requests at precisely the same
1899 moment (which would happen for instance at recovery
1900 from a power failure, when all systems will try to
1901 boot, thus flooding the BOOTP server. Defining
1902 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1903 inserted before sending out BOOTP requests. The
1904 following delays are inserted then:
1906 1st BOOTP request: delay 0 ... 1 sec
1907 2nd BOOTP request: delay 0 ... 2 sec
1908 3rd BOOTP request: delay 0 ... 4 sec
1910 BOOTP requests: delay 0 ... 8 sec
1912 - DHCP Advanced Options:
1913 You can fine tune the DHCP functionality by defining
1914 CONFIG_BOOTP_* symbols:
1916 CONFIG_BOOTP_SUBNETMASK
1917 CONFIG_BOOTP_GATEWAY
1918 CONFIG_BOOTP_HOSTNAME
1919 CONFIG_BOOTP_NISDOMAIN
1920 CONFIG_BOOTP_BOOTPATH
1921 CONFIG_BOOTP_BOOTFILESIZE
1924 CONFIG_BOOTP_SEND_HOSTNAME
1925 CONFIG_BOOTP_NTPSERVER
1926 CONFIG_BOOTP_TIMEOFFSET
1927 CONFIG_BOOTP_VENDOREX
1928 CONFIG_BOOTP_MAY_FAIL
1930 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1931 environment variable, not the BOOTP server.
1933 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1934 after the configured retry count, the call will fail
1935 instead of starting over. This can be used to fail over
1936 to Link-local IP address configuration if the DHCP server
1939 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1940 serverip from a DHCP server, it is possible that more
1941 than one DNS serverip is offered to the client.
1942 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1943 serverip will be stored in the additional environment
1944 variable "dnsip2". The first DNS serverip is always
1945 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1948 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1949 to do a dynamic update of a DNS server. To do this, they
1950 need the hostname of the DHCP requester.
1951 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1952 of the "hostname" environment variable is passed as
1953 option 12 to the DHCP server.
1955 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1957 A 32bit value in microseconds for a delay between
1958 receiving a "DHCP Offer" and sending the "DHCP Request".
1959 This fixes a problem with certain DHCP servers that don't
1960 respond 100% of the time to a "DHCP request". E.g. On an
1961 AT91RM9200 processor running at 180MHz, this delay needed
1962 to be *at least* 15,000 usec before a Windows Server 2003
1963 DHCP server would reply 100% of the time. I recommend at
1964 least 50,000 usec to be safe. The alternative is to hope
1965 that one of the retries will be successful but note that
1966 the DHCP timeout and retry process takes a longer than
1969 - Link-local IP address negotiation:
1970 Negotiate with other link-local clients on the local network
1971 for an address that doesn't require explicit configuration.
1972 This is especially useful if a DHCP server cannot be guaranteed
1973 to exist in all environments that the device must operate.
1975 See doc/README.link-local for more information.
1978 CONFIG_CDP_DEVICE_ID
1980 The device id used in CDP trigger frames.
1982 CONFIG_CDP_DEVICE_ID_PREFIX
1984 A two character string which is prefixed to the MAC address
1989 A printf format string which contains the ascii name of
1990 the port. Normally is set to "eth%d" which sets
1991 eth0 for the first Ethernet, eth1 for the second etc.
1993 CONFIG_CDP_CAPABILITIES
1995 A 32bit integer which indicates the device capabilities;
1996 0x00000010 for a normal host which does not forwards.
2000 An ascii string containing the version of the software.
2004 An ascii string containing the name of the platform.
2008 A 32bit integer sent on the trigger.
2010 CONFIG_CDP_POWER_CONSUMPTION
2012 A 16bit integer containing the power consumption of the
2013 device in .1 of milliwatts.
2015 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2017 A byte containing the id of the VLAN.
2019 - Status LED: CONFIG_STATUS_LED
2021 Several configurations allow to display the current
2022 status using a LED. For instance, the LED will blink
2023 fast while running U-Boot code, stop blinking as
2024 soon as a reply to a BOOTP request was received, and
2025 start blinking slow once the Linux kernel is running
2026 (supported by a status LED driver in the Linux
2027 kernel). Defining CONFIG_STATUS_LED enables this
2033 The status LED can be connected to a GPIO pin.
2034 In such cases, the gpio_led driver can be used as a
2035 status LED backend implementation. Define CONFIG_GPIO_LED
2036 to include the gpio_led driver in the U-Boot binary.
2038 CONFIG_GPIO_LED_INVERTED_TABLE
2039 Some GPIO connected LEDs may have inverted polarity in which
2040 case the GPIO high value corresponds to LED off state and
2041 GPIO low value corresponds to LED on state.
2042 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2043 with a list of GPIO LEDs that have inverted polarity.
2045 - CAN Support: CONFIG_CAN_DRIVER
2047 Defining CONFIG_CAN_DRIVER enables CAN driver support
2048 on those systems that support this (optional)
2049 feature, like the TQM8xxL modules.
2051 - I2C Support: CONFIG_SYS_I2C
2053 This enable the NEW i2c subsystem, and will allow you to use
2054 i2c commands at the u-boot command line (as long as you set
2055 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2056 based realtime clock chips or other i2c devices. See
2057 common/cmd_i2c.c for a description of the command line
2060 ported i2c driver to the new framework:
2061 - drivers/i2c/soft_i2c.c:
2062 - activate first bus with CONFIG_SYS_I2C_SOFT define
2063 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2064 for defining speed and slave address
2065 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2066 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2067 for defining speed and slave address
2068 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2069 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2070 for defining speed and slave address
2071 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2072 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2073 for defining speed and slave address
2075 - drivers/i2c/fsl_i2c.c:
2076 - activate i2c driver with CONFIG_SYS_I2C_FSL
2077 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2078 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2079 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2081 - If your board supports a second fsl i2c bus, define
2082 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2083 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2084 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2087 - drivers/i2c/tegra_i2c.c:
2088 - activate this driver with CONFIG_SYS_I2C_TEGRA
2089 - This driver adds 4 i2c buses with a fix speed from
2090 100000 and the slave addr 0!
2092 - drivers/i2c/ppc4xx_i2c.c
2093 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2094 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2095 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2097 - drivers/i2c/i2c_mxc.c
2098 - activate this driver with CONFIG_SYS_I2C_MXC
2099 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2100 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2101 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2102 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2103 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2104 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2105 If thoses defines are not set, default value is 100000
2106 for speed, and 0 for slave.
2108 - drivers/i2c/rcar_i2c.c:
2109 - activate this driver with CONFIG_SYS_I2C_RCAR
2110 - This driver adds 4 i2c buses
2112 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2113 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2114 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2115 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2116 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2117 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2118 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2119 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2120 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2122 - drivers/i2c/sh_i2c.c:
2123 - activate this driver with CONFIG_SYS_I2C_SH
2124 - This driver adds from 2 to 5 i2c buses
2126 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2127 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2128 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2129 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2130 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2131 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2132 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2133 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2134 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2135 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2136 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2137 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2138 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2140 - drivers/i2c/omap24xx_i2c.c
2141 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2142 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2143 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2144 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2145 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2146 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2147 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2148 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2149 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2150 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2151 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2153 - drivers/i2c/zynq_i2c.c
2154 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2155 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2156 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2158 - drivers/i2c/s3c24x0_i2c.c:
2159 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2160 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2161 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2162 with a fix speed from 100000 and the slave addr 0!
2166 CONFIG_SYS_NUM_I2C_BUSES
2167 Hold the number of i2c busses you want to use. If you
2168 don't use/have i2c muxes on your i2c bus, this
2169 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2172 CONFIG_SYS_I2C_DIRECT_BUS
2173 define this, if you don't use i2c muxes on your hardware.
2174 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2177 CONFIG_SYS_I2C_MAX_HOPS
2178 define how many muxes are maximal consecutively connected
2179 on one i2c bus. If you not use i2c muxes, omit this
2182 CONFIG_SYS_I2C_BUSES
2183 hold a list of busses you want to use, only used if
2184 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2185 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2186 CONFIG_SYS_NUM_I2C_BUSES = 9:
2188 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2189 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2190 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2191 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2192 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2193 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2194 {1, {I2C_NULL_HOP}}, \
2195 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2196 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2200 bus 0 on adapter 0 without a mux
2201 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2202 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2203 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2204 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2205 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2206 bus 6 on adapter 1 without a mux
2207 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2208 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2210 If you do not have i2c muxes on your board, omit this define.
2212 - Legacy I2C Support: CONFIG_HARD_I2C
2214 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2215 provides the following compelling advantages:
2217 - more than one i2c adapter is usable
2218 - approved multibus support
2219 - better i2c mux support
2221 ** Please consider updating your I2C driver now. **
2223 These enable legacy I2C serial bus commands. Defining
2224 CONFIG_HARD_I2C will include the appropriate I2C driver
2225 for the selected CPU.
2227 This will allow you to use i2c commands at the u-boot
2228 command line (as long as you set CONFIG_CMD_I2C in
2229 CONFIG_COMMANDS) and communicate with i2c based realtime
2230 clock chips. See common/cmd_i2c.c for a description of the
2231 command line interface.
2233 CONFIG_HARD_I2C selects a hardware I2C controller.
2235 There are several other quantities that must also be
2236 defined when you define CONFIG_HARD_I2C.
2238 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2239 to be the frequency (in Hz) at which you wish your i2c bus
2240 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2241 the CPU's i2c node address).
2243 Now, the u-boot i2c code for the mpc8xx
2244 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2245 and so its address should therefore be cleared to 0 (See,
2246 eg, MPC823e User's Manual p.16-473). So, set
2247 CONFIG_SYS_I2C_SLAVE to 0.
2249 CONFIG_SYS_I2C_INIT_MPC5XXX
2251 When a board is reset during an i2c bus transfer
2252 chips might think that the current transfer is still
2253 in progress. Reset the slave devices by sending start
2254 commands until the slave device responds.
2256 That's all that's required for CONFIG_HARD_I2C.
2258 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2259 then the following macros need to be defined (examples are
2260 from include/configs/lwmon.h):
2264 (Optional). Any commands necessary to enable the I2C
2265 controller or configure ports.
2267 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2271 (Only for MPC8260 CPU). The I/O port to use (the code
2272 assumes both bits are on the same port). Valid values
2273 are 0..3 for ports A..D.
2277 The code necessary to make the I2C data line active
2278 (driven). If the data line is open collector, this
2281 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2285 The code necessary to make the I2C data line tri-stated
2286 (inactive). If the data line is open collector, this
2289 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2293 Code that returns true if the I2C data line is high,
2296 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2300 If <bit> is true, sets the I2C data line high. If it
2301 is false, it clears it (low).
2303 eg: #define I2C_SDA(bit) \
2304 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2305 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2309 If <bit> is true, sets the I2C clock line high. If it
2310 is false, it clears it (low).
2312 eg: #define I2C_SCL(bit) \
2313 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2314 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2318 This delay is invoked four times per clock cycle so this
2319 controls the rate of data transfer. The data rate thus
2320 is 1 / (I2C_DELAY * 4). Often defined to be something
2323 #define I2C_DELAY udelay(2)
2325 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2327 If your arch supports the generic GPIO framework (asm/gpio.h),
2328 then you may alternatively define the two GPIOs that are to be
2329 used as SCL / SDA. Any of the previous I2C_xxx macros will
2330 have GPIO-based defaults assigned to them as appropriate.
2332 You should define these to the GPIO value as given directly to
2333 the generic GPIO functions.
2335 CONFIG_SYS_I2C_INIT_BOARD
2337 When a board is reset during an i2c bus transfer
2338 chips might think that the current transfer is still
2339 in progress. On some boards it is possible to access
2340 the i2c SCLK line directly, either by using the
2341 processor pin as a GPIO or by having a second pin
2342 connected to the bus. If this option is defined a
2343 custom i2c_init_board() routine in boards/xxx/board.c
2344 is run early in the boot sequence.
2346 CONFIG_SYS_I2C_BOARD_LATE_INIT
2348 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2349 defined a custom i2c_board_late_init() routine in
2350 boards/xxx/board.c is run AFTER the operations in i2c_init()
2351 is completed. This callpoint can be used to unreset i2c bus
2352 using CPU i2c controller register accesses for CPUs whose i2c
2353 controller provide such a method. It is called at the end of
2354 i2c_init() to allow i2c_init operations to setup the i2c bus
2355 controller on the CPU (e.g. setting bus speed & slave address).
2357 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2359 This option enables configuration of bi_iic_fast[] flags
2360 in u-boot bd_info structure based on u-boot environment
2361 variable "i2cfast". (see also i2cfast)
2363 CONFIG_I2C_MULTI_BUS
2365 This option allows the use of multiple I2C buses, each of which
2366 must have a controller. At any point in time, only one bus is
2367 active. To switch to a different bus, use the 'i2c dev' command.
2368 Note that bus numbering is zero-based.
2370 CONFIG_SYS_I2C_NOPROBES
2372 This option specifies a list of I2C devices that will be skipped
2373 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2374 is set, specify a list of bus-device pairs. Otherwise, specify
2375 a 1D array of device addresses
2378 #undef CONFIG_I2C_MULTI_BUS
2379 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2381 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2383 #define CONFIG_I2C_MULTI_BUS
2384 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2386 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2388 CONFIG_SYS_SPD_BUS_NUM
2390 If defined, then this indicates the I2C bus number for DDR SPD.
2391 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2393 CONFIG_SYS_RTC_BUS_NUM
2395 If defined, then this indicates the I2C bus number for the RTC.
2396 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2398 CONFIG_SYS_DTT_BUS_NUM
2400 If defined, then this indicates the I2C bus number for the DTT.
2401 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2403 CONFIG_SYS_I2C_DTT_ADDR:
2405 If defined, specifies the I2C address of the DTT device.
2406 If not defined, then U-Boot uses predefined value for
2407 specified DTT device.
2409 CONFIG_SOFT_I2C_READ_REPEATED_START
2411 defining this will force the i2c_read() function in
2412 the soft_i2c driver to perform an I2C repeated start
2413 between writing the address pointer and reading the
2414 data. If this define is omitted the default behaviour
2415 of doing a stop-start sequence will be used. Most I2C
2416 devices can use either method, but some require one or
2419 - SPI Support: CONFIG_SPI
2421 Enables SPI driver (so far only tested with
2422 SPI EEPROM, also an instance works with Crystal A/D and
2423 D/As on the SACSng board)
2427 Enables the driver for SPI controller on SuperH. Currently
2428 only SH7757 is supported.
2432 Enables extended (16-bit) SPI EEPROM addressing.
2433 (symmetrical to CONFIG_I2C_X)
2437 Enables a software (bit-bang) SPI driver rather than
2438 using hardware support. This is a general purpose
2439 driver that only requires three general I/O port pins
2440 (two outputs, one input) to function. If this is
2441 defined, the board configuration must define several
2442 SPI configuration items (port pins to use, etc). For
2443 an example, see include/configs/sacsng.h.
2447 Enables a hardware SPI driver for general-purpose reads
2448 and writes. As with CONFIG_SOFT_SPI, the board configuration
2449 must define a list of chip-select function pointers.
2450 Currently supported on some MPC8xxx processors. For an
2451 example, see include/configs/mpc8349emds.h.
2455 Enables the driver for the SPI controllers on i.MX and MXC
2456 SoCs. Currently i.MX31/35/51 are supported.
2458 - FPGA Support: CONFIG_FPGA
2460 Enables FPGA subsystem.
2462 CONFIG_FPGA_<vendor>
2464 Enables support for specific chip vendors.
2467 CONFIG_FPGA_<family>
2469 Enables support for FPGA family.
2470 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2474 Specify the number of FPGA devices to support.
2476 CONFIG_SYS_FPGA_PROG_FEEDBACK
2478 Enable printing of hash marks during FPGA configuration.
2480 CONFIG_SYS_FPGA_CHECK_BUSY
2482 Enable checks on FPGA configuration interface busy
2483 status by the configuration function. This option
2484 will require a board or device specific function to
2489 If defined, a function that provides delays in the FPGA
2490 configuration driver.
2492 CONFIG_SYS_FPGA_CHECK_CTRLC
2493 Allow Control-C to interrupt FPGA configuration
2495 CONFIG_SYS_FPGA_CHECK_ERROR
2497 Check for configuration errors during FPGA bitfile
2498 loading. For example, abort during Virtex II
2499 configuration if the INIT_B line goes low (which
2500 indicated a CRC error).
2502 CONFIG_SYS_FPGA_WAIT_INIT
2504 Maximum time to wait for the INIT_B line to deassert
2505 after PROB_B has been deasserted during a Virtex II
2506 FPGA configuration sequence. The default time is 500
2509 CONFIG_SYS_FPGA_WAIT_BUSY
2511 Maximum time to wait for BUSY to deassert during
2512 Virtex II FPGA configuration. The default is 5 ms.
2514 CONFIG_SYS_FPGA_WAIT_CONFIG
2516 Time to wait after FPGA configuration. The default is
2519 - Configuration Management:
2522 If defined, this string will be added to the U-Boot
2523 version information (U_BOOT_VERSION)
2525 - Vendor Parameter Protection:
2527 U-Boot considers the values of the environment
2528 variables "serial#" (Board Serial Number) and
2529 "ethaddr" (Ethernet Address) to be parameters that
2530 are set once by the board vendor / manufacturer, and
2531 protects these variables from casual modification by
2532 the user. Once set, these variables are read-only,
2533 and write or delete attempts are rejected. You can
2534 change this behaviour:
2536 If CONFIG_ENV_OVERWRITE is #defined in your config
2537 file, the write protection for vendor parameters is
2538 completely disabled. Anybody can change or delete
2541 Alternatively, if you #define _both_ CONFIG_ETHADDR
2542 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2543 Ethernet address is installed in the environment,
2544 which can be changed exactly ONCE by the user. [The
2545 serial# is unaffected by this, i. e. it remains
2548 The same can be accomplished in a more flexible way
2549 for any variable by configuring the type of access
2550 to allow for those variables in the ".flags" variable
2551 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2556 Define this variable to enable the reservation of
2557 "protected RAM", i. e. RAM which is not overwritten
2558 by U-Boot. Define CONFIG_PRAM to hold the number of
2559 kB you want to reserve for pRAM. You can overwrite
2560 this default value by defining an environment
2561 variable "pram" to the number of kB you want to
2562 reserve. Note that the board info structure will
2563 still show the full amount of RAM. If pRAM is
2564 reserved, a new environment variable "mem" will
2565 automatically be defined to hold the amount of
2566 remaining RAM in a form that can be passed as boot
2567 argument to Linux, for instance like that:
2569 setenv bootargs ... mem=\${mem}
2572 This way you can tell Linux not to use this memory,
2573 either, which results in a memory region that will
2574 not be affected by reboots.
2576 *WARNING* If your board configuration uses automatic
2577 detection of the RAM size, you must make sure that
2578 this memory test is non-destructive. So far, the
2579 following board configurations are known to be
2582 IVMS8, IVML24, SPD8xx, TQM8xxL,
2583 HERMES, IP860, RPXlite, LWMON,
2586 - Access to physical memory region (> 4GB)
2587 Some basic support is provided for operations on memory not
2588 normally accessible to U-Boot - e.g. some architectures
2589 support access to more than 4GB of memory on 32-bit
2590 machines using physical address extension or similar.
2591 Define CONFIG_PHYSMEM to access this basic support, which
2592 currently only supports clearing the memory.
2597 Define this variable to stop the system in case of a
2598 fatal error, so that you have to reset it manually.
2599 This is probably NOT a good idea for an embedded
2600 system where you want the system to reboot
2601 automatically as fast as possible, but it may be
2602 useful during development since you can try to debug
2603 the conditions that lead to the situation.
2605 CONFIG_NET_RETRY_COUNT
2607 This variable defines the number of retries for
2608 network operations like ARP, RARP, TFTP, or BOOTP
2609 before giving up the operation. If not defined, a
2610 default value of 5 is used.
2614 Timeout waiting for an ARP reply in milliseconds.
2618 Timeout in milliseconds used in NFS protocol.
2619 If you encounter "ERROR: Cannot umount" in nfs command,
2620 try longer timeout such as
2621 #define CONFIG_NFS_TIMEOUT 10000UL
2623 - Command Interpreter:
2624 CONFIG_AUTO_COMPLETE
2626 Enable auto completion of commands using TAB.
2628 Note that this feature has NOT been implemented yet
2629 for the "hush" shell.
2632 CONFIG_SYS_HUSH_PARSER
2634 Define this variable to enable the "hush" shell (from
2635 Busybox) as command line interpreter, thus enabling
2636 powerful command line syntax like
2637 if...then...else...fi conditionals or `&&' and '||'
2638 constructs ("shell scripts").
2640 If undefined, you get the old, much simpler behaviour
2641 with a somewhat smaller memory footprint.
2644 CONFIG_SYS_PROMPT_HUSH_PS2
2646 This defines the secondary prompt string, which is
2647 printed when the command interpreter needs more input
2648 to complete a command. Usually "> ".
2652 In the current implementation, the local variables
2653 space and global environment variables space are
2654 separated. Local variables are those you define by
2655 simply typing `name=value'. To access a local
2656 variable later on, you have write `$name' or
2657 `${name}'; to execute the contents of a variable
2658 directly type `$name' at the command prompt.
2660 Global environment variables are those you use
2661 setenv/printenv to work with. To run a command stored
2662 in such a variable, you need to use the run command,
2663 and you must not use the '$' sign to access them.
2665 To store commands and special characters in a
2666 variable, please use double quotation marks
2667 surrounding the whole text of the variable, instead
2668 of the backslashes before semicolons and special
2671 - Commandline Editing and History:
2672 CONFIG_CMDLINE_EDITING
2674 Enable editing and History functions for interactive
2675 commandline input operations
2677 - Default Environment:
2678 CONFIG_EXTRA_ENV_SETTINGS
2680 Define this to contain any number of null terminated
2681 strings (variable = value pairs) that will be part of
2682 the default environment compiled into the boot image.
2684 For example, place something like this in your
2685 board's config file:
2687 #define CONFIG_EXTRA_ENV_SETTINGS \
2691 Warning: This method is based on knowledge about the
2692 internal format how the environment is stored by the
2693 U-Boot code. This is NOT an official, exported
2694 interface! Although it is unlikely that this format
2695 will change soon, there is no guarantee either.
2696 You better know what you are doing here.
2698 Note: overly (ab)use of the default environment is
2699 discouraged. Make sure to check other ways to preset
2700 the environment like the "source" command or the
2703 CONFIG_ENV_VARS_UBOOT_CONFIG
2705 Define this in order to add variables describing the
2706 U-Boot build configuration to the default environment.
2707 These will be named arch, cpu, board, vendor, and soc.
2709 Enabling this option will cause the following to be defined:
2717 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2719 Define this in order to add variables describing certain
2720 run-time determined information about the hardware to the
2721 environment. These will be named board_name, board_rev.
2723 CONFIG_DELAY_ENVIRONMENT
2725 Normally the environment is loaded when the board is
2726 intialised so that it is available to U-Boot. This inhibits
2727 that so that the environment is not available until
2728 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2729 this is instead controlled by the value of
2730 /config/load-environment.
2732 - DataFlash Support:
2733 CONFIG_HAS_DATAFLASH
2735 Defining this option enables DataFlash features and
2736 allows to read/write in Dataflash via the standard
2739 - Serial Flash support
2742 Defining this option enables SPI flash commands
2743 'sf probe/read/write/erase/update'.
2745 Usage requires an initial 'probe' to define the serial
2746 flash parameters, followed by read/write/erase/update
2749 The following defaults may be provided by the platform
2750 to handle the common case when only a single serial
2751 flash is present on the system.
2753 CONFIG_SF_DEFAULT_BUS Bus identifier
2754 CONFIG_SF_DEFAULT_CS Chip-select
2755 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2756 CONFIG_SF_DEFAULT_SPEED in Hz
2760 Define this option to include a destructive SPI flash
2763 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2765 Define this option to use the Bank addr/Extended addr
2766 support on SPI flashes which has size > 16Mbytes.
2768 CONFIG_SF_DUAL_FLASH Dual flash memories
2770 Define this option to use dual flash support where two flash
2771 memories can be connected with a given cs line.
2772 currently Xilinx Zynq qspi support these type of connections.
2774 - SystemACE Support:
2777 Adding this option adds support for Xilinx SystemACE
2778 chips attached via some sort of local bus. The address
2779 of the chip must also be defined in the
2780 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2782 #define CONFIG_SYSTEMACE
2783 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2785 When SystemACE support is added, the "ace" device type
2786 becomes available to the fat commands, i.e. fatls.
2788 - TFTP Fixed UDP Port:
2791 If this is defined, the environment variable tftpsrcp
2792 is used to supply the TFTP UDP source port value.
2793 If tftpsrcp isn't defined, the normal pseudo-random port
2794 number generator is used.
2796 Also, the environment variable tftpdstp is used to supply
2797 the TFTP UDP destination port value. If tftpdstp isn't
2798 defined, the normal port 69 is used.
2800 The purpose for tftpsrcp is to allow a TFTP server to
2801 blindly start the TFTP transfer using the pre-configured
2802 target IP address and UDP port. This has the effect of
2803 "punching through" the (Windows XP) firewall, allowing
2804 the remainder of the TFTP transfer to proceed normally.
2805 A better solution is to properly configure the firewall,
2806 but sometimes that is not allowed.
2811 This enables a generic 'hash' command which can produce
2812 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2816 Enable the hash verify command (hash -v). This adds to code
2819 CONFIG_SHA1 - support SHA1 hashing
2820 CONFIG_SHA256 - support SHA256 hashing
2822 Note: There is also a sha1sum command, which should perhaps
2823 be deprecated in favour of 'hash sha1'.
2825 - Freescale i.MX specific commands:
2826 CONFIG_CMD_HDMIDETECT
2827 This enables 'hdmidet' command which returns true if an
2828 HDMI monitor is detected. This command is i.MX 6 specific.
2831 This enables the 'bmode' (bootmode) command for forcing
2832 a boot from specific media.
2834 This is useful for forcing the ROM's usb downloader to
2835 activate upon a watchdog reset which is nice when iterating
2836 on U-Boot. Using the reset button or running bmode normal
2837 will set it back to normal. This command currently
2838 supports i.MX53 and i.MX6.
2843 This enables the RSA algorithm used for FIT image verification
2844 in U-Boot. See doc/uImage/signature for more information.
2846 The signing part is build into mkimage regardless of this
2850 - Show boot progress:
2851 CONFIG_SHOW_BOOT_PROGRESS
2853 Defining this option allows to add some board-
2854 specific code (calling a user-provided function
2855 "show_boot_progress(int)") that enables you to show
2856 the system's boot progress on some display (for
2857 example, some LED's) on your board. At the moment,
2858 the following checkpoints are implemented:
2860 - Detailed boot stage timing
2862 Define this option to get detailed timing of each stage
2863 of the boot process.
2865 CONFIG_BOOTSTAGE_USER_COUNT
2866 This is the number of available user bootstage records.
2867 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2868 a new ID will be allocated from this stash. If you exceed
2869 the limit, recording will stop.
2871 CONFIG_BOOTSTAGE_REPORT
2872 Define this to print a report before boot, similar to this:
2874 Timer summary in microseconds:
2877 3,575,678 3,575,678 board_init_f start
2878 3,575,695 17 arch_cpu_init A9
2879 3,575,777 82 arch_cpu_init done
2880 3,659,598 83,821 board_init_r start
2881 3,910,375 250,777 main_loop
2882 29,916,167 26,005,792 bootm_start
2883 30,361,327 445,160 start_kernel
2885 CONFIG_CMD_BOOTSTAGE
2886 Add a 'bootstage' command which supports printing a report
2887 and un/stashing of bootstage data.
2889 CONFIG_BOOTSTAGE_FDT
2890 Stash the bootstage information in the FDT. A root 'bootstage'
2891 node is created with each bootstage id as a child. Each child
2892 has a 'name' property and either 'mark' containing the
2893 mark time in microsecond, or 'accum' containing the
2894 accumulated time for that bootstage id in microseconds.
2899 name = "board_init_f";
2908 Code in the Linux kernel can find this in /proc/devicetree.
2910 Legacy uImage format:
2913 1 common/cmd_bootm.c before attempting to boot an image
2914 -1 common/cmd_bootm.c Image header has bad magic number
2915 2 common/cmd_bootm.c Image header has correct magic number
2916 -2 common/cmd_bootm.c Image header has bad checksum
2917 3 common/cmd_bootm.c Image header has correct checksum
2918 -3 common/cmd_bootm.c Image data has bad checksum
2919 4 common/cmd_bootm.c Image data has correct checksum
2920 -4 common/cmd_bootm.c Image is for unsupported architecture
2921 5 common/cmd_bootm.c Architecture check OK
2922 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2923 6 common/cmd_bootm.c Image Type check OK
2924 -6 common/cmd_bootm.c gunzip uncompression error
2925 -7 common/cmd_bootm.c Unimplemented compression type
2926 7 common/cmd_bootm.c Uncompression OK
2927 8 common/cmd_bootm.c No uncompress/copy overwrite error
2928 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2930 9 common/image.c Start initial ramdisk verification
2931 -10 common/image.c Ramdisk header has bad magic number
2932 -11 common/image.c Ramdisk header has bad checksum
2933 10 common/image.c Ramdisk header is OK
2934 -12 common/image.c Ramdisk data has bad checksum
2935 11 common/image.c Ramdisk data has correct checksum
2936 12 common/image.c Ramdisk verification complete, start loading
2937 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2938 13 common/image.c Start multifile image verification
2939 14 common/image.c No initial ramdisk, no multifile, continue.
2941 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2943 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2944 -31 post/post.c POST test failed, detected by post_output_backlog()
2945 -32 post/post.c POST test failed, detected by post_run_single()
2947 34 common/cmd_doc.c before loading a Image from a DOC device
2948 -35 common/cmd_doc.c Bad usage of "doc" command
2949 35 common/cmd_doc.c correct usage of "doc" command
2950 -36 common/cmd_doc.c No boot device
2951 36 common/cmd_doc.c correct boot device
2952 -37 common/cmd_doc.c Unknown Chip ID on boot device
2953 37 common/cmd_doc.c correct chip ID found, device available
2954 -38 common/cmd_doc.c Read Error on boot device
2955 38 common/cmd_doc.c reading Image header from DOC device OK
2956 -39 common/cmd_doc.c Image header has bad magic number
2957 39 common/cmd_doc.c Image header has correct magic number
2958 -40 common/cmd_doc.c Error reading Image from DOC device
2959 40 common/cmd_doc.c Image header has correct magic number
2960 41 common/cmd_ide.c before loading a Image from a IDE device
2961 -42 common/cmd_ide.c Bad usage of "ide" command
2962 42 common/cmd_ide.c correct usage of "ide" command
2963 -43 common/cmd_ide.c No boot device
2964 43 common/cmd_ide.c boot device found
2965 -44 common/cmd_ide.c Device not available
2966 44 common/cmd_ide.c Device available
2967 -45 common/cmd_ide.c wrong partition selected
2968 45 common/cmd_ide.c partition selected
2969 -46 common/cmd_ide.c Unknown partition table
2970 46 common/cmd_ide.c valid partition table found
2971 -47 common/cmd_ide.c Invalid partition type
2972 47 common/cmd_ide.c correct partition type
2973 -48 common/cmd_ide.c Error reading Image Header on boot device
2974 48 common/cmd_ide.c reading Image Header from IDE device OK
2975 -49 common/cmd_ide.c Image header has bad magic number
2976 49 common/cmd_ide.c Image header has correct magic number
2977 -50 common/cmd_ide.c Image header has bad checksum
2978 50 common/cmd_ide.c Image header has correct checksum
2979 -51 common/cmd_ide.c Error reading Image from IDE device
2980 51 common/cmd_ide.c reading Image from IDE device OK
2981 52 common/cmd_nand.c before loading a Image from a NAND device
2982 -53 common/cmd_nand.c Bad usage of "nand" command
2983 53 common/cmd_nand.c correct usage of "nand" command
2984 -54 common/cmd_nand.c No boot device
2985 54 common/cmd_nand.c boot device found
2986 -55 common/cmd_nand.c Unknown Chip ID on boot device
2987 55 common/cmd_nand.c correct chip ID found, device available
2988 -56 common/cmd_nand.c Error reading Image Header on boot device
2989 56 common/cmd_nand.c reading Image Header from NAND device OK
2990 -57 common/cmd_nand.c Image header has bad magic number
2991 57 common/cmd_nand.c Image header has correct magic number
2992 -58 common/cmd_nand.c Error reading Image from NAND device
2993 58 common/cmd_nand.c reading Image from NAND device OK
2995 -60 common/env_common.c Environment has a bad CRC, using default
2997 64 net/eth.c starting with Ethernet configuration.
2998 -64 net/eth.c no Ethernet found.
2999 65 net/eth.c Ethernet found.
3001 -80 common/cmd_net.c usage wrong
3002 80 common/cmd_net.c before calling NetLoop()
3003 -81 common/cmd_net.c some error in NetLoop() occurred
3004 81 common/cmd_net.c NetLoop() back without error
3005 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3006 82 common/cmd_net.c trying automatic boot
3007 83 common/cmd_net.c running "source" command
3008 -83 common/cmd_net.c some error in automatic boot or "source" command
3009 84 common/cmd_net.c end without errors
3014 100 common/cmd_bootm.c Kernel FIT Image has correct format
3015 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3016 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3017 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3018 102 common/cmd_bootm.c Kernel unit name specified
3019 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3020 103 common/cmd_bootm.c Found configuration node
3021 104 common/cmd_bootm.c Got kernel subimage node offset
3022 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3023 105 common/cmd_bootm.c Kernel subimage hash verification OK
3024 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3025 106 common/cmd_bootm.c Architecture check OK
3026 -106 common/cmd_bootm.c Kernel subimage has wrong type
3027 107 common/cmd_bootm.c Kernel subimage type OK
3028 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3029 108 common/cmd_bootm.c Got kernel subimage data/size
3030 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3031 -109 common/cmd_bootm.c Can't get kernel subimage type
3032 -110 common/cmd_bootm.c Can't get kernel subimage comp
3033 -111 common/cmd_bootm.c Can't get kernel subimage os
3034 -112 common/cmd_bootm.c Can't get kernel subimage load address
3035 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3037 120 common/image.c Start initial ramdisk verification
3038 -120 common/image.c Ramdisk FIT image has incorrect format
3039 121 common/image.c Ramdisk FIT image has correct format
3040 122 common/image.c No ramdisk subimage unit name, using configuration
3041 -122 common/image.c Can't get configuration for ramdisk subimage
3042 123 common/image.c Ramdisk unit name specified
3043 -124 common/image.c Can't get ramdisk subimage node offset
3044 125 common/image.c Got ramdisk subimage node offset
3045 -125 common/image.c Ramdisk subimage hash verification failed
3046 126 common/image.c Ramdisk subimage hash verification OK
3047 -126 common/image.c Ramdisk subimage for unsupported architecture
3048 127 common/image.c Architecture check OK
3049 -127 common/image.c Can't get ramdisk subimage data/size
3050 128 common/image.c Got ramdisk subimage data/size
3051 129 common/image.c Can't get ramdisk load address
3052 -129 common/image.c Got ramdisk load address
3054 -130 common/cmd_doc.c Incorrect FIT image format
3055 131 common/cmd_doc.c FIT image format OK
3057 -140 common/cmd_ide.c Incorrect FIT image format
3058 141 common/cmd_ide.c FIT image format OK
3060 -150 common/cmd_nand.c Incorrect FIT image format
3061 151 common/cmd_nand.c FIT image format OK
3063 - FIT image support:
3065 Enable support for the FIT uImage format.
3067 CONFIG_FIT_BEST_MATCH
3068 When no configuration is explicitly selected, default to the
3069 one whose fdt's compatibility field best matches that of
3070 U-Boot itself. A match is considered "best" if it matches the
3071 most specific compatibility entry of U-Boot's fdt's root node.
3072 The order of entries in the configuration's fdt is ignored.
3074 CONFIG_FIT_SIGNATURE
3075 This option enables signature verification of FIT uImages,
3076 using a hash signed and verified using RSA. See
3077 doc/uImage.FIT/signature.txt for more details.
3079 - Standalone program support:
3080 CONFIG_STANDALONE_LOAD_ADDR
3082 This option defines a board specific value for the
3083 address where standalone program gets loaded, thus
3084 overwriting the architecture dependent default
3087 - Frame Buffer Address:
3090 Define CONFIG_FB_ADDR if you want to use specific
3091 address for frame buffer. This is typically the case
3092 when using a graphics controller has separate video
3093 memory. U-Boot will then place the frame buffer at
3094 the given address instead of dynamically reserving it
3095 in system RAM by calling lcd_setmem(), which grabs
3096 the memory for the frame buffer depending on the
3097 configured panel size.
3099 Please see board_init_f function.
3101 - Automatic software updates via TFTP server
3103 CONFIG_UPDATE_TFTP_CNT_MAX
3104 CONFIG_UPDATE_TFTP_MSEC_MAX
3106 These options enable and control the auto-update feature;
3107 for a more detailed description refer to doc/README.update.
3109 - MTD Support (mtdparts command, UBI support)
3112 Adds the MTD device infrastructure from the Linux kernel.
3113 Needed for mtdparts command support.
3115 CONFIG_MTD_PARTITIONS
3117 Adds the MTD partitioning infrastructure from the Linux
3118 kernel. Needed for UBI support.
3123 Adds commands for interacting with MTD partitions formatted
3124 with the UBI flash translation layer
3126 Requires also defining CONFIG_RBTREE
3128 CONFIG_UBI_SILENCE_MSG
3130 Make the verbose messages from UBI stop printing. This leaves
3131 warnings and errors enabled.
3136 Adds commands for interacting with UBI volumes formatted as
3137 UBIFS. UBIFS is read-only in u-boot.
3139 Requires UBI support as well as CONFIG_LZO
3141 CONFIG_UBIFS_SILENCE_MSG
3143 Make the verbose messages from UBIFS stop printing. This leaves
3144 warnings and errors enabled.
3148 Enable building of SPL globally.
3151 LDSCRIPT for linking the SPL binary.
3153 CONFIG_SPL_MAX_FOOTPRINT
3154 Maximum size in memory allocated to the SPL, BSS included.
3155 When defined, the linker checks that the actual memory
3156 used by SPL from _start to __bss_end does not exceed it.
3157 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3158 must not be both defined at the same time.
3161 Maximum size of the SPL image (text, data, rodata, and
3162 linker lists sections), BSS excluded.
3163 When defined, the linker checks that the actual size does
3166 CONFIG_SPL_TEXT_BASE
3167 TEXT_BASE for linking the SPL binary.
3169 CONFIG_SPL_RELOC_TEXT_BASE
3170 Address to relocate to. If unspecified, this is equal to
3171 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3173 CONFIG_SPL_BSS_START_ADDR
3174 Link address for the BSS within the SPL binary.
3176 CONFIG_SPL_BSS_MAX_SIZE
3177 Maximum size in memory allocated to the SPL BSS.
3178 When defined, the linker checks that the actual memory used
3179 by SPL from __bss_start to __bss_end does not exceed it.
3180 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3181 must not be both defined at the same time.
3184 Adress of the start of the stack SPL will use
3186 CONFIG_SPL_RELOC_STACK
3187 Adress of the start of the stack SPL will use after
3188 relocation. If unspecified, this is equal to
3191 CONFIG_SYS_SPL_MALLOC_START
3192 Starting address of the malloc pool used in SPL.
3194 CONFIG_SYS_SPL_MALLOC_SIZE
3195 The size of the malloc pool used in SPL.
3197 CONFIG_SPL_FRAMEWORK
3198 Enable the SPL framework under common/. This framework
3199 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3200 NAND loading of the Linux Kernel.
3202 CONFIG_SPL_DISPLAY_PRINT
3203 For ARM, enable an optional function to print more information
3204 about the running system.
3206 CONFIG_SPL_INIT_MINIMAL
3207 Arch init code should be built for a very small image
3209 CONFIG_SPL_LIBCOMMON_SUPPORT
3210 Support for common/libcommon.o in SPL binary
3212 CONFIG_SPL_LIBDISK_SUPPORT
3213 Support for disk/libdisk.o in SPL binary
3215 CONFIG_SPL_I2C_SUPPORT
3216 Support for drivers/i2c/libi2c.o in SPL binary
3218 CONFIG_SPL_GPIO_SUPPORT
3219 Support for drivers/gpio/libgpio.o in SPL binary
3221 CONFIG_SPL_MMC_SUPPORT
3222 Support for drivers/mmc/libmmc.o in SPL binary
3224 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3225 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3226 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3227 Address, size and partition on the MMC to load U-Boot from
3228 when the MMC is being used in raw mode.
3230 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3231 Sector to load kernel uImage from when MMC is being
3232 used in raw mode (for Falcon mode)
3234 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3235 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3236 Sector and number of sectors to load kernel argument
3237 parameters from when MMC is being used in raw mode
3240 CONFIG_SPL_FAT_SUPPORT
3241 Support for fs/fat/libfat.o in SPL binary
3243 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3244 Filename to read to load U-Boot when reading from FAT
3246 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3247 Filename to read to load kernel uImage when reading
3248 from FAT (for Falcon mode)
3250 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3251 Filename to read to load kernel argument parameters
3252 when reading from FAT (for Falcon mode)
3254 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3255 Set this for NAND SPL on PPC mpc83xx targets, so that
3256 start.S waits for the rest of the SPL to load before
3257 continuing (the hardware starts execution after just
3258 loading the first page rather than the full 4K).
3260 CONFIG_SPL_NAND_BASE
3261 Include nand_base.c in the SPL. Requires
3262 CONFIG_SPL_NAND_DRIVERS.
3264 CONFIG_SPL_NAND_DRIVERS
3265 SPL uses normal NAND drivers, not minimal drivers.
3268 Include standard software ECC in the SPL
3270 CONFIG_SPL_NAND_SIMPLE
3271 Support for NAND boot using simple NAND drivers that
3272 expose the cmd_ctrl() interface.
3274 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3275 Set for the SPL on PPC mpc8xxx targets, support for
3276 drivers/ddr/fsl/libddr.o in SPL binary.
3278 CONFIG_SPL_COMMON_INIT_DDR
3279 Set for common ddr init with serial presence detect in
3282 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3283 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3284 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3285 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3286 CONFIG_SYS_NAND_ECCBYTES
3287 Defines the size and behavior of the NAND that SPL uses
3290 CONFIG_SPL_NAND_BOOT
3291 Add support NAND boot
3293 CONFIG_SYS_NAND_U_BOOT_OFFS
3294 Location in NAND to read U-Boot from
3296 CONFIG_SYS_NAND_U_BOOT_DST
3297 Location in memory to load U-Boot to
3299 CONFIG_SYS_NAND_U_BOOT_SIZE
3300 Size of image to load
3302 CONFIG_SYS_NAND_U_BOOT_START
3303 Entry point in loaded image to jump to
3305 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3306 Define this if you need to first read the OOB and then the
3307 data. This is used for example on davinci plattforms.
3309 CONFIG_SPL_OMAP3_ID_NAND
3310 Support for an OMAP3-specific set of functions to return the
3311 ID and MFR of the first attached NAND chip, if present.
3313 CONFIG_SPL_SERIAL_SUPPORT
3314 Support for drivers/serial/libserial.o in SPL binary
3316 CONFIG_SPL_SPI_FLASH_SUPPORT
3317 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3319 CONFIG_SPL_SPI_SUPPORT
3320 Support for drivers/spi/libspi.o in SPL binary
3322 CONFIG_SPL_RAM_DEVICE
3323 Support for running image already present in ram, in SPL binary
3325 CONFIG_SPL_LIBGENERIC_SUPPORT
3326 Support for lib/libgeneric.o in SPL binary
3328 CONFIG_SPL_ENV_SUPPORT
3329 Support for the environment operating in SPL binary
3331 CONFIG_SPL_NET_SUPPORT
3332 Support for the net/libnet.o in SPL binary.
3333 It conflicts with SPL env from storage medium specified by
3334 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3337 Image offset to which the SPL should be padded before appending
3338 the SPL payload. By default, this is defined as
3339 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3340 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3341 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3344 Final target image containing SPL and payload. Some SPLs
3345 use an arch-specific makefile fragment instead, for
3346 example if more than one image needs to be produced.
3348 CONFIG_FIT_SPL_PRINT
3349 Printing information about a FIT image adds quite a bit of
3350 code to SPL. So this is normally disabled in SPL. Use this
3351 option to re-enable it. This will affect the output of the
3352 bootm command when booting a FIT image.
3356 Enable building of TPL globally.
3359 Image offset to which the TPL should be padded before appending
3360 the TPL payload. By default, this is defined as
3361 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3362 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3363 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3368 [so far only for SMDK2400 boards]
3370 - Modem support enable:
3371 CONFIG_MODEM_SUPPORT
3373 - RTS/CTS Flow control enable:
3376 - Modem debug support:
3377 CONFIG_MODEM_SUPPORT_DEBUG
3379 Enables debugging stuff (char screen[1024], dbg())
3380 for modem support. Useful only with BDI2000.
3382 - Interrupt support (PPC):
3384 There are common interrupt_init() and timer_interrupt()
3385 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3386 for CPU specific initialization. interrupt_init_cpu()
3387 should set decrementer_count to appropriate value. If
3388 CPU resets decrementer automatically after interrupt
3389 (ppc4xx) it should set decrementer_count to zero.
3390 timer_interrupt() calls timer_interrupt_cpu() for CPU
3391 specific handling. If board has watchdog / status_led
3392 / other_activity_monitor it works automatically from
3393 general timer_interrupt().
3397 In the target system modem support is enabled when a
3398 specific key (key combination) is pressed during
3399 power-on. Otherwise U-Boot will boot normally
3400 (autoboot). The key_pressed() function is called from
3401 board_init(). Currently key_pressed() is a dummy
3402 function, returning 1 and thus enabling modem
3405 If there are no modem init strings in the
3406 environment, U-Boot proceed to autoboot; the
3407 previous output (banner, info printfs) will be
3410 See also: doc/README.Modem
3412 Board initialization settings:
3413 ------------------------------
3415 During Initialization u-boot calls a number of board specific functions
3416 to allow the preparation of board specific prerequisites, e.g. pin setup
3417 before drivers are initialized. To enable these callbacks the
3418 following configuration macros have to be defined. Currently this is
3419 architecture specific, so please check arch/your_architecture/lib/board.c
3420 typically in board_init_f() and board_init_r().
3422 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3423 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3424 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3425 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3427 Configuration Settings:
3428 -----------------------
3430 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3431 undefine this when you're short of memory.
3433 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3434 width of the commands listed in the 'help' command output.
3436 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3437 prompt for user input.
3439 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3441 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3443 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3445 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3446 the application (usually a Linux kernel) when it is
3449 - CONFIG_SYS_BAUDRATE_TABLE:
3450 List of legal baudrate settings for this board.
3452 - CONFIG_SYS_CONSOLE_INFO_QUIET
3453 Suppress display of console information at boot.
3455 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3456 If the board specific function
3457 extern int overwrite_console (void);
3458 returns 1, the stdin, stderr and stdout are switched to the
3459 serial port, else the settings in the environment are used.
3461 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3462 Enable the call to overwrite_console().
3464 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3465 Enable overwrite of previous console environment settings.
3467 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3468 Begin and End addresses of the area used by the
3471 - CONFIG_SYS_ALT_MEMTEST:
3472 Enable an alternate, more extensive memory test.
3474 - CONFIG_SYS_MEMTEST_SCRATCH:
3475 Scratch address used by the alternate memory test
3476 You only need to set this if address zero isn't writeable
3478 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3479 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3480 this specified memory area will get subtracted from the top
3481 (end) of RAM and won't get "touched" at all by U-Boot. By
3482 fixing up gd->ram_size the Linux kernel should gets passed
3483 the now "corrected" memory size and won't touch it either.
3484 This should work for arch/ppc and arch/powerpc. Only Linux
3485 board ports in arch/powerpc with bootwrapper support that
3486 recalculate the memory size from the SDRAM controller setup
3487 will have to get fixed in Linux additionally.
3489 This option can be used as a workaround for the 440EPx/GRx
3490 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3493 WARNING: Please make sure that this value is a multiple of
3494 the Linux page size (normally 4k). If this is not the case,
3495 then the end address of the Linux memory will be located at a
3496 non page size aligned address and this could cause major
3499 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3500 Enable temporary baudrate change while serial download
3502 - CONFIG_SYS_SDRAM_BASE:
3503 Physical start address of SDRAM. _Must_ be 0 here.
3505 - CONFIG_SYS_MBIO_BASE:
3506 Physical start address of Motherboard I/O (if using a
3509 - CONFIG_SYS_FLASH_BASE:
3510 Physical start address of Flash memory.
3512 - CONFIG_SYS_MONITOR_BASE:
3513 Physical start address of boot monitor code (set by
3514 make config files to be same as the text base address
3515 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3516 CONFIG_SYS_FLASH_BASE when booting from flash.
3518 - CONFIG_SYS_MONITOR_LEN:
3519 Size of memory reserved for monitor code, used to
3520 determine _at_compile_time_ (!) if the environment is
3521 embedded within the U-Boot image, or in a separate
3524 - CONFIG_SYS_MALLOC_LEN:
3525 Size of DRAM reserved for malloc() use.
3527 - CONFIG_SYS_BOOTM_LEN:
3528 Normally compressed uImages are limited to an
3529 uncompressed size of 8 MBytes. If this is not enough,
3530 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3531 to adjust this setting to your needs.
3533 - CONFIG_SYS_BOOTMAPSZ:
3534 Maximum size of memory mapped by the startup code of
3535 the Linux kernel; all data that must be processed by
3536 the Linux kernel (bd_info, boot arguments, FDT blob if
3537 used) must be put below this limit, unless "bootm_low"
3538 environment variable is defined and non-zero. In such case
3539 all data for the Linux kernel must be between "bootm_low"
3540 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3541 variable "bootm_mapsize" will override the value of
3542 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3543 then the value in "bootm_size" will be used instead.
3545 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3546 Enable initrd_high functionality. If defined then the
3547 initrd_high feature is enabled and the bootm ramdisk subcommand
3550 - CONFIG_SYS_BOOT_GET_CMDLINE:
3551 Enables allocating and saving kernel cmdline in space between
3552 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3554 - CONFIG_SYS_BOOT_GET_KBD:
3555 Enables allocating and saving a kernel copy of the bd_info in
3556 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3558 - CONFIG_SYS_MAX_FLASH_BANKS:
3559 Max number of Flash memory banks
3561 - CONFIG_SYS_MAX_FLASH_SECT:
3562 Max number of sectors on a Flash chip
3564 - CONFIG_SYS_FLASH_ERASE_TOUT:
3565 Timeout for Flash erase operations (in ms)
3567 - CONFIG_SYS_FLASH_WRITE_TOUT:
3568 Timeout for Flash write operations (in ms)
3570 - CONFIG_SYS_FLASH_LOCK_TOUT
3571 Timeout for Flash set sector lock bit operation (in ms)
3573 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3574 Timeout for Flash clear lock bits operation (in ms)
3576 - CONFIG_SYS_FLASH_PROTECTION
3577 If defined, hardware flash sectors protection is used
3578 instead of U-Boot software protection.
3580 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3582 Enable TFTP transfers directly to flash memory;
3583 without this option such a download has to be
3584 performed in two steps: (1) download to RAM, and (2)
3585 copy from RAM to flash.
3587 The two-step approach is usually more reliable, since
3588 you can check if the download worked before you erase
3589 the flash, but in some situations (when system RAM is
3590 too limited to allow for a temporary copy of the
3591 downloaded image) this option may be very useful.
3593 - CONFIG_SYS_FLASH_CFI:
3594 Define if the flash driver uses extra elements in the
3595 common flash structure for storing flash geometry.
3597 - CONFIG_FLASH_CFI_DRIVER
3598 This option also enables the building of the cfi_flash driver
3599 in the drivers directory
3601 - CONFIG_FLASH_CFI_MTD
3602 This option enables the building of the cfi_mtd driver
3603 in the drivers directory. The driver exports CFI flash
3606 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3607 Use buffered writes to flash.
3609 - CONFIG_FLASH_SPANSION_S29WS_N
3610 s29ws-n MirrorBit flash has non-standard addresses for buffered
3613 - CONFIG_SYS_FLASH_QUIET_TEST
3614 If this option is defined, the common CFI flash doesn't
3615 print it's warning upon not recognized FLASH banks. This
3616 is useful, if some of the configured banks are only
3617 optionally available.
3619 - CONFIG_FLASH_SHOW_PROGRESS
3620 If defined (must be an integer), print out countdown
3621 digits and dots. Recommended value: 45 (9..1) for 80
3622 column displays, 15 (3..1) for 40 column displays.
3624 - CONFIG_FLASH_VERIFY
3625 If defined, the content of the flash (destination) is compared
3626 against the source after the write operation. An error message
3627 will be printed when the contents are not identical.
3628 Please note that this option is useless in nearly all cases,
3629 since such flash programming errors usually are detected earlier
3630 while unprotecting/erasing/programming. Please only enable
3631 this option if you really know what you are doing.
3633 - CONFIG_SYS_RX_ETH_BUFFER:
3634 Defines the number of Ethernet receive buffers. On some
3635 Ethernet controllers it is recommended to set this value
3636 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3637 buffers can be full shortly after enabling the interface
3638 on high Ethernet traffic.
3639 Defaults to 4 if not defined.
3641 - CONFIG_ENV_MAX_ENTRIES
3643 Maximum number of entries in the hash table that is used
3644 internally to store the environment settings. The default
3645 setting is supposed to be generous and should work in most
3646 cases. This setting can be used to tune behaviour; see
3647 lib/hashtable.c for details.
3649 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3650 - CONFIG_ENV_FLAGS_LIST_STATIC
3651 Enable validation of the values given to environment variables when
3652 calling env set. Variables can be restricted to only decimal,
3653 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3654 the variables can also be restricted to IP address or MAC address.
3656 The format of the list is:
3657 type_attribute = [s|d|x|b|i|m]
3658 access_atribute = [a|r|o|c]
3659 attributes = type_attribute[access_atribute]
3660 entry = variable_name[:attributes]
3663 The type attributes are:
3664 s - String (default)
3667 b - Boolean ([1yYtT|0nNfF])
3671 The access attributes are:
3677 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3678 Define this to a list (string) to define the ".flags"
3679 envirnoment variable in the default or embedded environment.
3681 - CONFIG_ENV_FLAGS_LIST_STATIC
3682 Define this to a list (string) to define validation that
3683 should be done if an entry is not found in the ".flags"
3684 environment variable. To override a setting in the static
3685 list, simply add an entry for the same variable name to the
3688 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3689 If defined, don't allow the -f switch to env set override variable
3692 - CONFIG_SYS_GENERIC_BOARD
3693 This selects the architecture-generic board system instead of the
3694 architecture-specific board files. It is intended to move boards
3695 to this new framework over time. Defining this will disable the
3696 arch/foo/lib/board.c file and use common/board_f.c and
3697 common/board_r.c instead. To use this option your architecture
3698 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3699 its config.mk file). If you find problems enabling this option on
3700 your board please report the problem and send patches!
3702 - CONFIG_SYS_SYM_OFFSETS
3703 This is set by architectures that use offsets for link symbols
3704 instead of absolute values. So bss_start is obtained using an
3705 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3706 directly. You should not need to touch this setting.
3708 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3709 This is set by OMAP boards for the max time that reset should
3710 be asserted. See doc/README.omap-reset-time for details on how
3711 the value can be calulated on a given board.
3713 The following definitions that deal with the placement and management
3714 of environment data (variable area); in general, we support the
3715 following configurations:
3717 - CONFIG_BUILD_ENVCRC:
3719 Builds up envcrc with the target environment so that external utils
3720 may easily extract it and embed it in final U-Boot images.
3722 - CONFIG_ENV_IS_IN_FLASH:
3724 Define this if the environment is in flash memory.
3726 a) The environment occupies one whole flash sector, which is
3727 "embedded" in the text segment with the U-Boot code. This
3728 happens usually with "bottom boot sector" or "top boot
3729 sector" type flash chips, which have several smaller
3730 sectors at the start or the end. For instance, such a
3731 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3732 such a case you would place the environment in one of the
3733 4 kB sectors - with U-Boot code before and after it. With
3734 "top boot sector" type flash chips, you would put the
3735 environment in one of the last sectors, leaving a gap
3736 between U-Boot and the environment.
3738 - CONFIG_ENV_OFFSET:
3740 Offset of environment data (variable area) to the
3741 beginning of flash memory; for instance, with bottom boot
3742 type flash chips the second sector can be used: the offset
3743 for this sector is given here.
3745 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3749 This is just another way to specify the start address of
3750 the flash sector containing the environment (instead of
3753 - CONFIG_ENV_SECT_SIZE:
3755 Size of the sector containing the environment.
3758 b) Sometimes flash chips have few, equal sized, BIG sectors.
3759 In such a case you don't want to spend a whole sector for
3764 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3765 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3766 of this flash sector for the environment. This saves
3767 memory for the RAM copy of the environment.
3769 It may also save flash memory if you decide to use this
3770 when your environment is "embedded" within U-Boot code,
3771 since then the remainder of the flash sector could be used
3772 for U-Boot code. It should be pointed out that this is
3773 STRONGLY DISCOURAGED from a robustness point of view:
3774 updating the environment in flash makes it always
3775 necessary to erase the WHOLE sector. If something goes
3776 wrong before the contents has been restored from a copy in
3777 RAM, your target system will be dead.
3779 - CONFIG_ENV_ADDR_REDUND
3780 CONFIG_ENV_SIZE_REDUND
3782 These settings describe a second storage area used to hold
3783 a redundant copy of the environment data, so that there is
3784 a valid backup copy in case there is a power failure during
3785 a "saveenv" operation.
3787 BE CAREFUL! Any changes to the flash layout, and some changes to the
3788 source code will make it necessary to adapt <board>/u-boot.lds*
3792 - CONFIG_ENV_IS_IN_NVRAM:
3794 Define this if you have some non-volatile memory device
3795 (NVRAM, battery buffered SRAM) which you want to use for the
3801 These two #defines are used to determine the memory area you
3802 want to use for environment. It is assumed that this memory
3803 can just be read and written to, without any special
3806 BE CAREFUL! The first access to the environment happens quite early
3807 in U-Boot initalization (when we try to get the setting of for the
3808 console baudrate). You *MUST* have mapped your NVRAM area then, or
3811 Please note that even with NVRAM we still use a copy of the
3812 environment in RAM: we could work on NVRAM directly, but we want to
3813 keep settings there always unmodified except somebody uses "saveenv"
3814 to save the current settings.
3817 - CONFIG_ENV_IS_IN_EEPROM:
3819 Use this if you have an EEPROM or similar serial access
3820 device and a driver for it.
3822 - CONFIG_ENV_OFFSET:
3825 These two #defines specify the offset and size of the
3826 environment area within the total memory of your EEPROM.
3828 - CONFIG_SYS_I2C_EEPROM_ADDR:
3829 If defined, specified the chip address of the EEPROM device.
3830 The default address is zero.
3832 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3833 If defined, the number of bits used to address bytes in a
3834 single page in the EEPROM device. A 64 byte page, for example
3835 would require six bits.
3837 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3838 If defined, the number of milliseconds to delay between
3839 page writes. The default is zero milliseconds.
3841 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3842 The length in bytes of the EEPROM memory array address. Note
3843 that this is NOT the chip address length!
3845 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3846 EEPROM chips that implement "address overflow" are ones
3847 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3848 address and the extra bits end up in the "chip address" bit
3849 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3852 Note that we consider the length of the address field to
3853 still be one byte because the extra address bits are hidden
3854 in the chip address.
3856 - CONFIG_SYS_EEPROM_SIZE:
3857 The size in bytes of the EEPROM device.
3859 - CONFIG_ENV_EEPROM_IS_ON_I2C
3860 define this, if you have I2C and SPI activated, and your
3861 EEPROM, which holds the environment, is on the I2C bus.
3863 - CONFIG_I2C_ENV_EEPROM_BUS
3864 if you have an Environment on an EEPROM reached over
3865 I2C muxes, you can define here, how to reach this
3866 EEPROM. For example:
3868 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3870 EEPROM which holds the environment, is reached over
3871 a pca9547 i2c mux with address 0x70, channel 3.
3873 - CONFIG_ENV_IS_IN_DATAFLASH:
3875 Define this if you have a DataFlash memory device which you
3876 want to use for the environment.
3878 - CONFIG_ENV_OFFSET:
3882 These three #defines specify the offset and size of the
3883 environment area within the total memory of your DataFlash placed
3884 at the specified address.
3886 - CONFIG_ENV_IS_IN_REMOTE:
3888 Define this if you have a remote memory space which you
3889 want to use for the local device's environment.
3894 These two #defines specify the address and size of the
3895 environment area within the remote memory space. The
3896 local device can get the environment from remote memory
3897 space by SRIO or PCIE links.
3899 BE CAREFUL! For some special cases, the local device can not use
3900 "saveenv" command. For example, the local device will get the
3901 environment stored in a remote NOR flash by SRIO or PCIE link,
3902 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3904 - CONFIG_ENV_IS_IN_NAND:
3906 Define this if you have a NAND device which you want to use
3907 for the environment.
3909 - CONFIG_ENV_OFFSET:
3912 These two #defines specify the offset and size of the environment
3913 area within the first NAND device. CONFIG_ENV_OFFSET must be
3914 aligned to an erase block boundary.
3916 - CONFIG_ENV_OFFSET_REDUND (optional):
3918 This setting describes a second storage area of CONFIG_ENV_SIZE
3919 size used to hold a redundant copy of the environment data, so
3920 that there is a valid backup copy in case there is a power failure
3921 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3922 aligned to an erase block boundary.
3924 - CONFIG_ENV_RANGE (optional):
3926 Specifies the length of the region in which the environment
3927 can be written. This should be a multiple of the NAND device's
3928 block size. Specifying a range with more erase blocks than
3929 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3930 the range to be avoided.
3932 - CONFIG_ENV_OFFSET_OOB (optional):
3934 Enables support for dynamically retrieving the offset of the
3935 environment from block zero's out-of-band data. The
3936 "nand env.oob" command can be used to record this offset.
3937 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3938 using CONFIG_ENV_OFFSET_OOB.
3940 - CONFIG_NAND_ENV_DST
3942 Defines address in RAM to which the nand_spl code should copy the
3943 environment. If redundant environment is used, it will be copied to
3944 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3946 - CONFIG_ENV_IS_IN_UBI:
3948 Define this if you have an UBI volume that you want to use for the
3949 environment. This has the benefit of wear-leveling the environment
3950 accesses, which is important on NAND.
3952 - CONFIG_ENV_UBI_PART:
3954 Define this to a string that is the mtd partition containing the UBI.
3956 - CONFIG_ENV_UBI_VOLUME:
3958 Define this to the name of the volume that you want to store the
3961 - CONFIG_ENV_UBI_VOLUME_REDUND:
3963 Define this to the name of another volume to store a second copy of
3964 the environment in. This will enable redundant environments in UBI.
3965 It is assumed that both volumes are in the same MTD partition.
3967 - CONFIG_UBI_SILENCE_MSG
3968 - CONFIG_UBIFS_SILENCE_MSG
3970 You will probably want to define these to avoid a really noisy system
3971 when storing the env in UBI.
3973 - CONFIG_ENV_IS_IN_MMC:
3975 Define this if you have an MMC device which you want to use for the
3978 - CONFIG_SYS_MMC_ENV_DEV:
3980 Specifies which MMC device the environment is stored in.
3982 - CONFIG_SYS_MMC_ENV_PART (optional):
3984 Specifies which MMC partition the environment is stored in. If not
3985 set, defaults to partition 0, the user area. Common values might be
3986 1 (first MMC boot partition), 2 (second MMC boot partition).
3988 - CONFIG_ENV_OFFSET:
3991 These two #defines specify the offset and size of the environment
3992 area within the specified MMC device.
3994 If offset is positive (the usual case), it is treated as relative to
3995 the start of the MMC partition. If offset is negative, it is treated
3996 as relative to the end of the MMC partition. This can be useful if
3997 your board may be fitted with different MMC devices, which have
3998 different sizes for the MMC partitions, and you always want the
3999 environment placed at the very end of the partition, to leave the
4000 maximum possible space before it, to store other data.
4002 These two values are in units of bytes, but must be aligned to an
4003 MMC sector boundary.
4005 - CONFIG_ENV_OFFSET_REDUND (optional):
4007 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4008 hold a redundant copy of the environment data. This provides a
4009 valid backup copy in case the other copy is corrupted, e.g. due
4010 to a power failure during a "saveenv" operation.
4012 This value may also be positive or negative; this is handled in the
4013 same way as CONFIG_ENV_OFFSET.
4015 This value is also in units of bytes, but must also be aligned to
4016 an MMC sector boundary.
4018 - CONFIG_ENV_SIZE_REDUND (optional):
4020 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4021 set. If this value is set, it must be set to the same value as
4024 - CONFIG_SYS_SPI_INIT_OFFSET
4026 Defines offset to the initial SPI buffer area in DPRAM. The
4027 area is used at an early stage (ROM part) if the environment
4028 is configured to reside in the SPI EEPROM: We need a 520 byte
4029 scratch DPRAM area. It is used between the two initialization
4030 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4031 to be a good choice since it makes it far enough from the
4032 start of the data area as well as from the stack pointer.
4034 Please note that the environment is read-only until the monitor
4035 has been relocated to RAM and a RAM copy of the environment has been
4036 created; also, when using EEPROM you will have to use getenv_f()
4037 until then to read environment variables.
4039 The environment is protected by a CRC32 checksum. Before the monitor
4040 is relocated into RAM, as a result of a bad CRC you will be working
4041 with the compiled-in default environment - *silently*!!! [This is
4042 necessary, because the first environment variable we need is the
4043 "baudrate" setting for the console - if we have a bad CRC, we don't
4044 have any device yet where we could complain.]
4046 Note: once the monitor has been relocated, then it will complain if
4047 the default environment is used; a new CRC is computed as soon as you
4048 use the "saveenv" command to store a valid environment.
4050 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4051 Echo the inverted Ethernet link state to the fault LED.
4053 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4054 also needs to be defined.
4056 - CONFIG_SYS_FAULT_MII_ADDR:
4057 MII address of the PHY to check for the Ethernet link state.
4059 - CONFIG_NS16550_MIN_FUNCTIONS:
4060 Define this if you desire to only have use of the NS16550_init
4061 and NS16550_putc functions for the serial driver located at
4062 drivers/serial/ns16550.c. This option is useful for saving
4063 space for already greatly restricted images, including but not
4064 limited to NAND_SPL configurations.
4066 - CONFIG_DISPLAY_BOARDINFO
4067 Display information about the board that U-Boot is running on
4068 when U-Boot starts up. The board function checkboard() is called
4071 - CONFIG_DISPLAY_BOARDINFO_LATE
4072 Similar to the previous option, but display this information
4073 later, once stdio is running and output goes to the LCD, if
4076 Low Level (hardware related) configuration options:
4077 ---------------------------------------------------
4079 - CONFIG_SYS_CACHELINE_SIZE:
4080 Cache Line Size of the CPU.
4082 - CONFIG_SYS_DEFAULT_IMMR:
4083 Default address of the IMMR after system reset.
4085 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4086 and RPXsuper) to be able to adjust the position of
4087 the IMMR register after a reset.
4089 - CONFIG_SYS_CCSRBAR_DEFAULT:
4090 Default (power-on reset) physical address of CCSR on Freescale
4093 - CONFIG_SYS_CCSRBAR:
4094 Virtual address of CCSR. On a 32-bit build, this is typically
4095 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4097 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4098 for cross-platform code that uses that macro instead.
4100 - CONFIG_SYS_CCSRBAR_PHYS:
4101 Physical address of CCSR. CCSR can be relocated to a new
4102 physical address, if desired. In this case, this macro should
4103 be set to that address. Otherwise, it should be set to the
4104 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4105 is typically relocated on 36-bit builds. It is recommended
4106 that this macro be defined via the _HIGH and _LOW macros:
4108 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4109 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4111 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4112 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4113 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4114 used in assembly code, so it must not contain typecasts or
4115 integer size suffixes (e.g. "ULL").
4117 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4118 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4119 used in assembly code, so it must not contain typecasts or
4120 integer size suffixes (e.g. "ULL").
4122 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4123 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4124 forced to a value that ensures that CCSR is not relocated.
4126 - Floppy Disk Support:
4127 CONFIG_SYS_FDC_DRIVE_NUMBER
4129 the default drive number (default value 0)
4131 CONFIG_SYS_ISA_IO_STRIDE
4133 defines the spacing between FDC chipset registers
4136 CONFIG_SYS_ISA_IO_OFFSET
4138 defines the offset of register from address. It
4139 depends on which part of the data bus is connected to
4140 the FDC chipset. (default value 0)
4142 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4143 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4146 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4147 fdc_hw_init() is called at the beginning of the FDC
4148 setup. fdc_hw_init() must be provided by the board
4149 source code. It is used to make hardware dependant
4153 Most IDE controllers were designed to be connected with PCI
4154 interface. Only few of them were designed for AHB interface.
4155 When software is doing ATA command and data transfer to
4156 IDE devices through IDE-AHB controller, some additional
4157 registers accessing to these kind of IDE-AHB controller
4160 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4161 DO NOT CHANGE unless you know exactly what you're
4162 doing! (11-4) [MPC8xx/82xx systems only]
4164 - CONFIG_SYS_INIT_RAM_ADDR:
4166 Start address of memory area that can be used for
4167 initial data and stack; please note that this must be
4168 writable memory that is working WITHOUT special
4169 initialization, i. e. you CANNOT use normal RAM which
4170 will become available only after programming the
4171 memory controller and running certain initialization
4174 U-Boot uses the following memory types:
4175 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4176 - MPC824X: data cache
4177 - PPC4xx: data cache
4179 - CONFIG_SYS_GBL_DATA_OFFSET:
4181 Offset of the initial data structure in the memory
4182 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4183 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4184 data is located at the end of the available space
4185 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4186 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4187 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4188 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4191 On the MPC824X (or other systems that use the data
4192 cache for initial memory) the address chosen for
4193 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4194 point to an otherwise UNUSED address space between
4195 the top of RAM and the start of the PCI space.
4197 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4199 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4201 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4203 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4205 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4207 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4209 - CONFIG_SYS_OR_TIMING_SDRAM:
4212 - CONFIG_SYS_MAMR_PTA:
4213 periodic timer for refresh
4215 - CONFIG_SYS_DER: Debug Event Register (37-47)
4217 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4218 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4219 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4220 CONFIG_SYS_BR1_PRELIM:
4221 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4223 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4224 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4225 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4226 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4228 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4229 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4230 Machine Mode Register and Memory Periodic Timer
4231 Prescaler definitions (SDRAM timing)
4233 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4234 enable I2C microcode relocation patch (MPC8xx);
4235 define relocation offset in DPRAM [DSP2]
4237 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4238 enable SMC microcode relocation patch (MPC8xx);
4239 define relocation offset in DPRAM [SMC1]
4241 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4242 enable SPI microcode relocation patch (MPC8xx);
4243 define relocation offset in DPRAM [SCC4]
4245 - CONFIG_SYS_USE_OSCCLK:
4246 Use OSCM clock mode on MBX8xx board. Be careful,
4247 wrong setting might damage your board. Read
4248 doc/README.MBX before setting this variable!
4250 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4251 Offset of the bootmode word in DPRAM used by post
4252 (Power On Self Tests). This definition overrides
4253 #define'd default value in commproc.h resp.
4256 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4257 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4258 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4259 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4260 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4261 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4262 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4263 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4264 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4266 - CONFIG_PCI_DISABLE_PCIE:
4267 Disable PCI-Express on systems where it is supported but not
4270 - CONFIG_PCI_ENUM_ONLY
4271 Only scan through and get the devices on the busses.
4272 Don't do any setup work, presumably because someone or
4273 something has already done it, and we don't need to do it
4274 a second time. Useful for platforms that are pre-booted
4275 by coreboot or similar.
4277 - CONFIG_PCI_INDIRECT_BRIDGE:
4278 Enable support for indirect PCI bridges.
4281 Chip has SRIO or not
4284 Board has SRIO 1 port available
4287 Board has SRIO 2 port available
4289 - CONFIG_SRIO_PCIE_BOOT_MASTER
4290 Board can support master function for Boot from SRIO and PCIE
4292 - CONFIG_SYS_SRIOn_MEM_VIRT:
4293 Virtual Address of SRIO port 'n' memory region
4295 - CONFIG_SYS_SRIOn_MEM_PHYS:
4296 Physical Address of SRIO port 'n' memory region
4298 - CONFIG_SYS_SRIOn_MEM_SIZE:
4299 Size of SRIO port 'n' memory region
4301 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4302 Defined to tell the NAND controller that the NAND chip is using
4304 Not all NAND drivers use this symbol.
4305 Example of drivers that use it:
4306 - drivers/mtd/nand/ndfc.c
4307 - drivers/mtd/nand/mxc_nand.c
4309 - CONFIG_SYS_NDFC_EBC0_CFG
4310 Sets the EBC0_CFG register for the NDFC. If not defined
4311 a default value will be used.
4314 Get DDR timing information from an I2C EEPROM. Common
4315 with pluggable memory modules such as SODIMMs
4318 I2C address of the SPD EEPROM
4320 - CONFIG_SYS_SPD_BUS_NUM
4321 If SPD EEPROM is on an I2C bus other than the first
4322 one, specify here. Note that the value must resolve
4323 to something your driver can deal with.
4325 - CONFIG_SYS_DDR_RAW_TIMING
4326 Get DDR timing information from other than SPD. Common with
4327 soldered DDR chips onboard without SPD. DDR raw timing
4328 parameters are extracted from datasheet and hard-coded into
4329 header files or board specific files.
4331 - CONFIG_FSL_DDR_INTERACTIVE
4332 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4334 - CONFIG_SYS_83XX_DDR_USES_CS0
4335 Only for 83xx systems. If specified, then DDR should
4336 be configured using CS0 and CS1 instead of CS2 and CS3.
4338 - CONFIG_ETHER_ON_FEC[12]
4339 Define to enable FEC[12] on a 8xx series processor.
4341 - CONFIG_FEC[12]_PHY
4342 Define to the hardcoded PHY address which corresponds
4343 to the given FEC; i. e.
4344 #define CONFIG_FEC1_PHY 4
4345 means that the PHY with address 4 is connected to FEC1
4347 When set to -1, means to probe for first available.
4349 - CONFIG_FEC[12]_PHY_NORXERR
4350 The PHY does not have a RXERR line (RMII only).
4351 (so program the FEC to ignore it).
4354 Enable RMII mode for all FECs.
4355 Note that this is a global option, we can't
4356 have one FEC in standard MII mode and another in RMII mode.
4358 - CONFIG_CRC32_VERIFY
4359 Add a verify option to the crc32 command.
4362 => crc32 -v <address> <count> <crc32>
4364 Where address/count indicate a memory area
4365 and crc32 is the correct crc32 which the
4369 Add the "loopw" memory command. This only takes effect if
4370 the memory commands are activated globally (CONFIG_CMD_MEM).
4373 Add the "mdc" and "mwc" memory commands. These are cyclic
4378 This command will print 4 bytes (10,11,12,13) each 500 ms.
4380 => mwc.l 100 12345678 10
4381 This command will write 12345678 to address 100 all 10 ms.
4383 This only takes effect if the memory commands are activated
4384 globally (CONFIG_CMD_MEM).
4386 - CONFIG_SKIP_LOWLEVEL_INIT
4387 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4388 low level initializations (like setting up the memory
4389 controller) are omitted and/or U-Boot does not
4390 relocate itself into RAM.
4392 Normally this variable MUST NOT be defined. The only
4393 exception is when U-Boot is loaded (to RAM) by some
4394 other boot loader or by a debugger which performs
4395 these initializations itself.
4398 Modifies the behaviour of start.S when compiling a loader
4399 that is executed before the actual U-Boot. E.g. when
4400 compiling a NAND SPL.
4403 Modifies the behaviour of start.S when compiling a loader
4404 that is executed after the SPL and before the actual U-Boot.
4405 It is loaded by the SPL.
4407 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4408 Only for 85xx systems. If this variable is specified, the section
4409 .resetvec is not kept and the section .bootpg is placed in the
4410 previous 4k of the .text section.
4412 - CONFIG_ARCH_MAP_SYSMEM
4413 Generally U-Boot (and in particular the md command) uses
4414 effective address. It is therefore not necessary to regard
4415 U-Boot address as virtual addresses that need to be translated
4416 to physical addresses. However, sandbox requires this, since
4417 it maintains its own little RAM buffer which contains all
4418 addressable memory. This option causes some memory accesses
4419 to be mapped through map_sysmem() / unmap_sysmem().
4421 - CONFIG_USE_ARCH_MEMCPY
4422 CONFIG_USE_ARCH_MEMSET
4423 If these options are used a optimized version of memcpy/memset will
4424 be used if available. These functions may be faster under some
4425 conditions but may increase the binary size.
4427 - CONFIG_X86_RESET_VECTOR
4428 If defined, the x86 reset vector code is included. This is not
4429 needed when U-Boot is running from Coreboot.
4432 Defines the MPU clock speed (in MHz).
4434 NOTE : currently only supported on AM335x platforms.
4436 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4437 Enables the RTC32K OSC on AM33xx based plattforms
4439 Freescale QE/FMAN Firmware Support:
4440 -----------------------------------
4442 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4443 loading of "firmware", which is encoded in the QE firmware binary format.
4444 This firmware often needs to be loaded during U-Boot booting, so macros
4445 are used to identify the storage device (NOR flash, SPI, etc) and the address
4448 - CONFIG_SYS_QE_FMAN_FW_ADDR
4449 The address in the storage device where the firmware is located. The
4450 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4453 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4454 The maximum possible size of the firmware. The firmware binary format
4455 has a field that specifies the actual size of the firmware, but it
4456 might not be possible to read any part of the firmware unless some
4457 local storage is allocated to hold the entire firmware first.
4459 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4460 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4461 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4462 virtual address in NOR flash.
4464 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4465 Specifies that QE/FMAN firmware is located in NAND flash.
4466 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4468 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4469 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4470 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4472 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4473 Specifies that QE/FMAN firmware is located on the primary SPI
4474 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4476 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4477 Specifies that QE/FMAN firmware is located in the remote (master)
4478 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4479 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4480 window->master inbound window->master LAW->the ucode address in
4481 master's memory space.
4483 Building the Software:
4484 ======================
4486 Building U-Boot has been tested in several native build environments
4487 and in many different cross environments. Of course we cannot support
4488 all possibly existing versions of cross development tools in all
4489 (potentially obsolete) versions. In case of tool chain problems we
4490 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4491 which is extensively used to build and test U-Boot.
4493 If you are not using a native environment, it is assumed that you
4494 have GNU cross compiling tools available in your path. In this case,
4495 you must set the environment variable CROSS_COMPILE in your shell.
4496 Note that no changes to the Makefile or any other source files are
4497 necessary. For example using the ELDK on a 4xx CPU, please enter:
4499 $ CROSS_COMPILE=ppc_4xx-
4500 $ export CROSS_COMPILE
4502 Note: If you wish to generate Windows versions of the utilities in
4503 the tools directory you can use the MinGW toolchain
4504 (http://www.mingw.org). Set your HOST tools to the MinGW
4505 toolchain and execute 'make tools'. For example:
4507 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4509 Binaries such as tools/mkimage.exe will be created which can
4510 be executed on computers running Windows.
4512 U-Boot is intended to be simple to build. After installing the
4513 sources you must configure U-Boot for one specific board type. This
4518 where "NAME_config" is the name of one of the existing configu-
4519 rations; see boards.cfg for supported names.
4521 Note: for some board special configuration names may exist; check if
4522 additional information is available from the board vendor; for
4523 instance, the TQM823L systems are available without (standard)
4524 or with LCD support. You can select such additional "features"
4525 when choosing the configuration, i. e.
4528 - will configure for a plain TQM823L, i. e. no LCD support
4530 make TQM823L_LCD_config
4531 - will configure for a TQM823L with U-Boot console on LCD
4536 Finally, type "make all", and you should get some working U-Boot
4537 images ready for download to / installation on your system:
4539 - "u-boot.bin" is a raw binary image
4540 - "u-boot" is an image in ELF binary format
4541 - "u-boot.srec" is in Motorola S-Record format
4543 By default the build is performed locally and the objects are saved
4544 in the source directory. One of the two methods can be used to change
4545 this behavior and build U-Boot to some external directory:
4547 1. Add O= to the make command line invocations:
4549 make O=/tmp/build distclean
4550 make O=/tmp/build NAME_config
4551 make O=/tmp/build all
4553 2. Set environment variable BUILD_DIR to point to the desired location:
4555 export BUILD_DIR=/tmp/build
4560 Note that the command line "O=" setting overrides the BUILD_DIR environment
4564 Please be aware that the Makefiles assume you are using GNU make, so
4565 for instance on NetBSD you might need to use "gmake" instead of
4569 If the system board that you have is not listed, then you will need
4570 to port U-Boot to your hardware platform. To do this, follow these
4573 1. Add a new configuration option for your board to the toplevel
4574 "boards.cfg" file, using the existing entries as examples.
4575 Follow the instructions there to keep the boards in order.
4576 2. Create a new directory to hold your board specific code. Add any
4577 files you need. In your board directory, you will need at least
4578 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4579 3. Create a new configuration file "include/configs/<board>.h" for
4581 3. If you're porting U-Boot to a new CPU, then also create a new
4582 directory to hold your CPU specific code. Add any files you need.
4583 4. Run "make <board>_config" with your new name.
4584 5. Type "make", and you should get a working "u-boot.srec" file
4585 to be installed on your target system.
4586 6. Debug and solve any problems that might arise.
4587 [Of course, this last step is much harder than it sounds.]
4590 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4591 ==============================================================
4593 If you have modified U-Boot sources (for instance added a new board
4594 or support for new devices, a new CPU, etc.) you are expected to
4595 provide feedback to the other developers. The feedback normally takes
4596 the form of a "patch", i. e. a context diff against a certain (latest
4597 official or latest in the git repository) version of U-Boot sources.
4599 But before you submit such a patch, please verify that your modifi-
4600 cation did not break existing code. At least make sure that *ALL* of
4601 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4602 just run the "MAKEALL" script, which will configure and build U-Boot
4603 for ALL supported system. Be warned, this will take a while. You can
4604 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4605 environment variable to the script, i. e. to use the ELDK cross tools
4608 CROSS_COMPILE=ppc_8xx- MAKEALL
4610 or to build on a native PowerPC system you can type
4612 CROSS_COMPILE=' ' MAKEALL
4614 When using the MAKEALL script, the default behaviour is to build
4615 U-Boot in the source directory. This location can be changed by
4616 setting the BUILD_DIR environment variable. Also, for each target
4617 built, the MAKEALL script saves two log files (<target>.ERR and
4618 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4619 location can be changed by setting the MAKEALL_LOGDIR environment
4620 variable. For example:
4622 export BUILD_DIR=/tmp/build
4623 export MAKEALL_LOGDIR=/tmp/log
4624 CROSS_COMPILE=ppc_8xx- MAKEALL
4626 With the above settings build objects are saved in the /tmp/build,
4627 log files are saved in the /tmp/log and the source tree remains clean
4628 during the whole build process.
4631 See also "U-Boot Porting Guide" below.
4634 Monitor Commands - Overview:
4635 ============================
4637 go - start application at address 'addr'
4638 run - run commands in an environment variable
4639 bootm - boot application image from memory
4640 bootp - boot image via network using BootP/TFTP protocol
4641 bootz - boot zImage from memory
4642 tftpboot- boot image via network using TFTP protocol
4643 and env variables "ipaddr" and "serverip"
4644 (and eventually "gatewayip")
4645 tftpput - upload a file via network using TFTP protocol
4646 rarpboot- boot image via network using RARP/TFTP protocol
4647 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4648 loads - load S-Record file over serial line
4649 loadb - load binary file over serial line (kermit mode)
4651 mm - memory modify (auto-incrementing)
4652 nm - memory modify (constant address)
4653 mw - memory write (fill)
4655 cmp - memory compare
4656 crc32 - checksum calculation
4657 i2c - I2C sub-system
4658 sspi - SPI utility commands
4659 base - print or set address offset
4660 printenv- print environment variables
4661 setenv - set environment variables
4662 saveenv - save environment variables to persistent storage
4663 protect - enable or disable FLASH write protection
4664 erase - erase FLASH memory
4665 flinfo - print FLASH memory information
4666 nand - NAND memory operations (see doc/README.nand)
4667 bdinfo - print Board Info structure
4668 iminfo - print header information for application image
4669 coninfo - print console devices and informations
4670 ide - IDE sub-system
4671 loop - infinite loop on address range
4672 loopw - infinite write loop on address range
4673 mtest - simple RAM test
4674 icache - enable or disable instruction cache
4675 dcache - enable or disable data cache
4676 reset - Perform RESET of the CPU
4677 echo - echo args to console
4678 version - print monitor version
4679 help - print online help
4680 ? - alias for 'help'
4683 Monitor Commands - Detailed Description:
4684 ========================================
4688 For now: just type "help <command>".
4691 Environment Variables:
4692 ======================
4694 U-Boot supports user configuration using Environment Variables which
4695 can be made persistent by saving to Flash memory.
4697 Environment Variables are set using "setenv", printed using
4698 "printenv", and saved to Flash using "saveenv". Using "setenv"
4699 without a value can be used to delete a variable from the
4700 environment. As long as you don't save the environment you are
4701 working with an in-memory copy. In case the Flash area containing the
4702 environment is erased by accident, a default environment is provided.
4704 Some configuration options can be set using Environment Variables.
4706 List of environment variables (most likely not complete):
4708 baudrate - see CONFIG_BAUDRATE
4710 bootdelay - see CONFIG_BOOTDELAY
4712 bootcmd - see CONFIG_BOOTCOMMAND
4714 bootargs - Boot arguments when booting an RTOS image
4716 bootfile - Name of the image to load with TFTP
4718 bootm_low - Memory range available for image processing in the bootm
4719 command can be restricted. This variable is given as
4720 a hexadecimal number and defines lowest address allowed
4721 for use by the bootm command. See also "bootm_size"
4722 environment variable. Address defined by "bootm_low" is
4723 also the base of the initial memory mapping for the Linux
4724 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4727 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4728 This variable is given as a hexadecimal number and it
4729 defines the size of the memory region starting at base
4730 address bootm_low that is accessible by the Linux kernel
4731 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4732 as the default value if it is defined, and bootm_size is
4735 bootm_size - Memory range available for image processing in the bootm
4736 command can be restricted. This variable is given as
4737 a hexadecimal number and defines the size of the region
4738 allowed for use by the bootm command. See also "bootm_low"
4739 environment variable.
4741 updatefile - Location of the software update file on a TFTP server, used
4742 by the automatic software update feature. Please refer to
4743 documentation in doc/README.update for more details.
4745 autoload - if set to "no" (any string beginning with 'n'),
4746 "bootp" will just load perform a lookup of the
4747 configuration from the BOOTP server, but not try to
4748 load any image using TFTP
4750 autostart - if set to "yes", an image loaded using the "bootp",
4751 "rarpboot", "tftpboot" or "diskboot" commands will
4752 be automatically started (by internally calling
4755 If set to "no", a standalone image passed to the
4756 "bootm" command will be copied to the load address
4757 (and eventually uncompressed), but NOT be started.
4758 This can be used to load and uncompress arbitrary
4761 fdt_high - if set this restricts the maximum address that the
4762 flattened device tree will be copied into upon boot.
4763 For example, if you have a system with 1 GB memory
4764 at physical address 0x10000000, while Linux kernel
4765 only recognizes the first 704 MB as low memory, you
4766 may need to set fdt_high as 0x3C000000 to have the
4767 device tree blob be copied to the maximum address
4768 of the 704 MB low memory, so that Linux kernel can
4769 access it during the boot procedure.
4771 If this is set to the special value 0xFFFFFFFF then
4772 the fdt will not be copied at all on boot. For this
4773 to work it must reside in writable memory, have
4774 sufficient padding on the end of it for u-boot to
4775 add the information it needs into it, and the memory
4776 must be accessible by the kernel.
4778 fdtcontroladdr- if set this is the address of the control flattened
4779 device tree used by U-Boot when CONFIG_OF_CONTROL is
4782 i2cfast - (PPC405GP|PPC405EP only)
4783 if set to 'y' configures Linux I2C driver for fast
4784 mode (400kHZ). This environment variable is used in
4785 initialization code. So, for changes to be effective
4786 it must be saved and board must be reset.
4788 initrd_high - restrict positioning of initrd images:
4789 If this variable is not set, initrd images will be
4790 copied to the highest possible address in RAM; this
4791 is usually what you want since it allows for
4792 maximum initrd size. If for some reason you want to
4793 make sure that the initrd image is loaded below the
4794 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4795 variable to a value of "no" or "off" or "0".
4796 Alternatively, you can set it to a maximum upper
4797 address to use (U-Boot will still check that it
4798 does not overwrite the U-Boot stack and data).
4800 For instance, when you have a system with 16 MB
4801 RAM, and want to reserve 4 MB from use by Linux,
4802 you can do this by adding "mem=12M" to the value of
4803 the "bootargs" variable. However, now you must make
4804 sure that the initrd image is placed in the first
4805 12 MB as well - this can be done with
4807 setenv initrd_high 00c00000
4809 If you set initrd_high to 0xFFFFFFFF, this is an
4810 indication to U-Boot that all addresses are legal
4811 for the Linux kernel, including addresses in flash
4812 memory. In this case U-Boot will NOT COPY the
4813 ramdisk at all. This may be useful to reduce the
4814 boot time on your system, but requires that this
4815 feature is supported by your Linux kernel.
4817 ipaddr - IP address; needed for tftpboot command
4819 loadaddr - Default load address for commands like "bootp",
4820 "rarpboot", "tftpboot", "loadb" or "diskboot"
4822 loads_echo - see CONFIG_LOADS_ECHO
4824 serverip - TFTP server IP address; needed for tftpboot command
4826 bootretry - see CONFIG_BOOT_RETRY_TIME
4828 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4830 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4832 ethprime - controls which interface is used first.
4834 ethact - controls which interface is currently active.
4835 For example you can do the following
4837 => setenv ethact FEC
4838 => ping 192.168.0.1 # traffic sent on FEC
4839 => setenv ethact SCC
4840 => ping 10.0.0.1 # traffic sent on SCC
4842 ethrotate - When set to "no" U-Boot does not go through all
4843 available network interfaces.
4844 It just stays at the currently selected interface.
4846 netretry - When set to "no" each network operation will
4847 either succeed or fail without retrying.
4848 When set to "once" the network operation will
4849 fail when all the available network interfaces
4850 are tried once without success.
4851 Useful on scripts which control the retry operation
4854 npe_ucode - set load address for the NPE microcode
4856 silent_linux - If set then linux will be told to boot silently, by
4857 changing the console to be empty. If "yes" it will be
4858 made silent. If "no" it will not be made silent. If
4859 unset, then it will be made silent if the U-Boot console
4862 tftpsrcport - If this is set, the value is used for TFTP's
4865 tftpdstport - If this is set, the value is used for TFTP's UDP
4866 destination port instead of the Well Know Port 69.
4868 tftpblocksize - Block size to use for TFTP transfers; if not set,
4869 we use the TFTP server's default block size
4871 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4872 seconds, minimum value is 1000 = 1 second). Defines
4873 when a packet is considered to be lost so it has to
4874 be retransmitted. The default is 5000 = 5 seconds.
4875 Lowering this value may make downloads succeed
4876 faster in networks with high packet loss rates or
4877 with unreliable TFTP servers.
4879 vlan - When set to a value < 4095 the traffic over
4880 Ethernet is encapsulated/received over 802.1q
4883 The following image location variables contain the location of images
4884 used in booting. The "Image" column gives the role of the image and is
4885 not an environment variable name. The other columns are environment
4886 variable names. "File Name" gives the name of the file on a TFTP
4887 server, "RAM Address" gives the location in RAM the image will be
4888 loaded to, and "Flash Location" gives the image's address in NOR
4889 flash or offset in NAND flash.
4891 *Note* - these variables don't have to be defined for all boards, some
4892 boards currenlty use other variables for these purposes, and some
4893 boards use these variables for other purposes.
4895 Image File Name RAM Address Flash Location
4896 ----- --------- ----------- --------------
4897 u-boot u-boot u-boot_addr_r u-boot_addr
4898 Linux kernel bootfile kernel_addr_r kernel_addr
4899 device tree blob fdtfile fdt_addr_r fdt_addr
4900 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4902 The following environment variables may be used and automatically
4903 updated by the network boot commands ("bootp" and "rarpboot"),
4904 depending the information provided by your boot server:
4906 bootfile - see above
4907 dnsip - IP address of your Domain Name Server
4908 dnsip2 - IP address of your secondary Domain Name Server
4909 gatewayip - IP address of the Gateway (Router) to use
4910 hostname - Target hostname
4912 netmask - Subnet Mask
4913 rootpath - Pathname of the root filesystem on the NFS server
4914 serverip - see above
4917 There are two special Environment Variables:
4919 serial# - contains hardware identification information such
4920 as type string and/or serial number
4921 ethaddr - Ethernet address
4923 These variables can be set only once (usually during manufacturing of
4924 the board). U-Boot refuses to delete or overwrite these variables
4925 once they have been set once.
4928 Further special Environment Variables:
4930 ver - Contains the U-Boot version string as printed
4931 with the "version" command. This variable is
4932 readonly (see CONFIG_VERSION_VARIABLE).
4935 Please note that changes to some configuration parameters may take
4936 only effect after the next boot (yes, that's just like Windoze :-).
4939 Callback functions for environment variables:
4940 ---------------------------------------------
4942 For some environment variables, the behavior of u-boot needs to change
4943 when their values are changed. This functionailty allows functions to
4944 be associated with arbitrary variables. On creation, overwrite, or
4945 deletion, the callback will provide the opportunity for some side
4946 effect to happen or for the change to be rejected.
4948 The callbacks are named and associated with a function using the
4949 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4951 These callbacks are associated with variables in one of two ways. The
4952 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4953 in the board configuration to a string that defines a list of
4954 associations. The list must be in the following format:
4956 entry = variable_name[:callback_name]
4959 If the callback name is not specified, then the callback is deleted.
4960 Spaces are also allowed anywhere in the list.
4962 Callbacks can also be associated by defining the ".callbacks" variable
4963 with the same list format above. Any association in ".callbacks" will
4964 override any association in the static list. You can define
4965 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4966 ".callbacks" envirnoment variable in the default or embedded environment.
4969 Command Line Parsing:
4970 =====================
4972 There are two different command line parsers available with U-Boot:
4973 the old "simple" one, and the much more powerful "hush" shell:
4975 Old, simple command line parser:
4976 --------------------------------
4978 - supports environment variables (through setenv / saveenv commands)
4979 - several commands on one line, separated by ';'
4980 - variable substitution using "... ${name} ..." syntax
4981 - special characters ('$', ';') can be escaped by prefixing with '\',
4983 setenv bootcmd bootm \${address}
4984 - You can also escape text by enclosing in single apostrophes, for example:
4985 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4990 - similar to Bourne shell, with control structures like
4991 if...then...else...fi, for...do...done; while...do...done,
4992 until...do...done, ...
4993 - supports environment ("global") variables (through setenv / saveenv
4994 commands) and local shell variables (through standard shell syntax
4995 "name=value"); only environment variables can be used with "run"
5001 (1) If a command line (or an environment variable executed by a "run"
5002 command) contains several commands separated by semicolon, and
5003 one of these commands fails, then the remaining commands will be
5006 (2) If you execute several variables with one call to run (i. e.
5007 calling run with a list of variables as arguments), any failing
5008 command will cause "run" to terminate, i. e. the remaining
5009 variables are not executed.
5011 Note for Redundant Ethernet Interfaces:
5012 =======================================
5014 Some boards come with redundant Ethernet interfaces; U-Boot supports
5015 such configurations and is capable of automatic selection of a
5016 "working" interface when needed. MAC assignment works as follows:
5018 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5019 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5020 "eth1addr" (=>eth1), "eth2addr", ...
5022 If the network interface stores some valid MAC address (for instance
5023 in SROM), this is used as default address if there is NO correspon-
5024 ding setting in the environment; if the corresponding environment
5025 variable is set, this overrides the settings in the card; that means:
5027 o If the SROM has a valid MAC address, and there is no address in the
5028 environment, the SROM's address is used.
5030 o If there is no valid address in the SROM, and a definition in the
5031 environment exists, then the value from the environment variable is
5034 o If both the SROM and the environment contain a MAC address, and
5035 both addresses are the same, this MAC address is used.
5037 o If both the SROM and the environment contain a MAC address, and the
5038 addresses differ, the value from the environment is used and a
5041 o If neither SROM nor the environment contain a MAC address, an error
5044 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5045 will be programmed into hardware as part of the initialization process. This
5046 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5047 The naming convention is as follows:
5048 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5053 U-Boot is capable of booting (and performing other auxiliary operations on)
5054 images in two formats:
5056 New uImage format (FIT)
5057 -----------------------
5059 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5060 to Flattened Device Tree). It allows the use of images with multiple
5061 components (several kernels, ramdisks, etc.), with contents protected by
5062 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5068 Old image format is based on binary files which can be basically anything,
5069 preceded by a special header; see the definitions in include/image.h for
5070 details; basically, the header defines the following image properties:
5072 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5073 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5074 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5075 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5077 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5078 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5079 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5080 * Compression Type (uncompressed, gzip, bzip2)
5086 The header is marked by a special Magic Number, and both the header
5087 and the data portions of the image are secured against corruption by
5094 Although U-Boot should support any OS or standalone application
5095 easily, the main focus has always been on Linux during the design of
5098 U-Boot includes many features that so far have been part of some
5099 special "boot loader" code within the Linux kernel. Also, any
5100 "initrd" images to be used are no longer part of one big Linux image;
5101 instead, kernel and "initrd" are separate images. This implementation
5102 serves several purposes:
5104 - the same features can be used for other OS or standalone
5105 applications (for instance: using compressed images to reduce the
5106 Flash memory footprint)
5108 - it becomes much easier to port new Linux kernel versions because
5109 lots of low-level, hardware dependent stuff are done by U-Boot
5111 - the same Linux kernel image can now be used with different "initrd"
5112 images; of course this also means that different kernel images can
5113 be run with the same "initrd". This makes testing easier (you don't
5114 have to build a new "zImage.initrd" Linux image when you just
5115 change a file in your "initrd"). Also, a field-upgrade of the
5116 software is easier now.
5122 Porting Linux to U-Boot based systems:
5123 ---------------------------------------
5125 U-Boot cannot save you from doing all the necessary modifications to
5126 configure the Linux device drivers for use with your target hardware
5127 (no, we don't intend to provide a full virtual machine interface to
5130 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5132 Just make sure your machine specific header file (for instance
5133 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5134 Information structure as we define in include/asm-<arch>/u-boot.h,
5135 and make sure that your definition of IMAP_ADDR uses the same value
5136 as your U-Boot configuration in CONFIG_SYS_IMMR.
5139 Configuring the Linux kernel:
5140 -----------------------------
5142 No specific requirements for U-Boot. Make sure you have some root
5143 device (initial ramdisk, NFS) for your target system.
5146 Building a Linux Image:
5147 -----------------------
5149 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5150 not used. If you use recent kernel source, a new build target
5151 "uImage" will exist which automatically builds an image usable by
5152 U-Boot. Most older kernels also have support for a "pImage" target,
5153 which was introduced for our predecessor project PPCBoot and uses a
5154 100% compatible format.
5163 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5164 encapsulate a compressed Linux kernel image with header information,
5165 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5167 * build a standard "vmlinux" kernel image (in ELF binary format):
5169 * convert the kernel into a raw binary image:
5171 ${CROSS_COMPILE}-objcopy -O binary \
5172 -R .note -R .comment \
5173 -S vmlinux linux.bin
5175 * compress the binary image:
5179 * package compressed binary image for U-Boot:
5181 mkimage -A ppc -O linux -T kernel -C gzip \
5182 -a 0 -e 0 -n "Linux Kernel Image" \
5183 -d linux.bin.gz uImage
5186 The "mkimage" tool can also be used to create ramdisk images for use
5187 with U-Boot, either separated from the Linux kernel image, or
5188 combined into one file. "mkimage" encapsulates the images with a 64
5189 byte header containing information about target architecture,
5190 operating system, image type, compression method, entry points, time
5191 stamp, CRC32 checksums, etc.
5193 "mkimage" can be called in two ways: to verify existing images and
5194 print the header information, or to build new images.
5196 In the first form (with "-l" option) mkimage lists the information
5197 contained in the header of an existing U-Boot image; this includes
5198 checksum verification:
5200 tools/mkimage -l image
5201 -l ==> list image header information
5203 The second form (with "-d" option) is used to build a U-Boot image
5204 from a "data file" which is used as image payload:
5206 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5207 -n name -d data_file image
5208 -A ==> set architecture to 'arch'
5209 -O ==> set operating system to 'os'
5210 -T ==> set image type to 'type'
5211 -C ==> set compression type 'comp'
5212 -a ==> set load address to 'addr' (hex)
5213 -e ==> set entry point to 'ep' (hex)
5214 -n ==> set image name to 'name'
5215 -d ==> use image data from 'datafile'
5217 Right now, all Linux kernels for PowerPC systems use the same load
5218 address (0x00000000), but the entry point address depends on the
5221 - 2.2.x kernels have the entry point at 0x0000000C,
5222 - 2.3.x and later kernels have the entry point at 0x00000000.
5224 So a typical call to build a U-Boot image would read:
5226 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5227 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5228 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5229 > examples/uImage.TQM850L
5230 Image Name: 2.4.4 kernel for TQM850L
5231 Created: Wed Jul 19 02:34:59 2000
5232 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5233 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5234 Load Address: 0x00000000
5235 Entry Point: 0x00000000
5237 To verify the contents of the image (or check for corruption):
5239 -> tools/mkimage -l examples/uImage.TQM850L
5240 Image Name: 2.4.4 kernel for TQM850L
5241 Created: Wed Jul 19 02:34:59 2000
5242 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5243 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5244 Load Address: 0x00000000
5245 Entry Point: 0x00000000
5247 NOTE: for embedded systems where boot time is critical you can trade
5248 speed for memory and install an UNCOMPRESSED image instead: this
5249 needs more space in Flash, but boots much faster since it does not
5250 need to be uncompressed:
5252 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5253 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5254 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5255 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5256 > examples/uImage.TQM850L-uncompressed
5257 Image Name: 2.4.4 kernel for TQM850L
5258 Created: Wed Jul 19 02:34:59 2000
5259 Image Type: PowerPC Linux Kernel Image (uncompressed)
5260 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5261 Load Address: 0x00000000
5262 Entry Point: 0x00000000
5265 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5266 when your kernel is intended to use an initial ramdisk:
5268 -> tools/mkimage -n 'Simple Ramdisk Image' \
5269 > -A ppc -O linux -T ramdisk -C gzip \
5270 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5271 Image Name: Simple Ramdisk Image
5272 Created: Wed Jan 12 14:01:50 2000
5273 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5274 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5275 Load Address: 0x00000000
5276 Entry Point: 0x00000000
5278 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5279 option performs the converse operation of the mkimage's second form (the "-d"
5280 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5283 tools/dumpimage -i image -p position data_file
5284 -i ==> extract from the 'image' a specific 'data_file', \
5285 indexed by 'position'
5288 Installing a Linux Image:
5289 -------------------------
5291 To downloading a U-Boot image over the serial (console) interface,
5292 you must convert the image to S-Record format:
5294 objcopy -I binary -O srec examples/image examples/image.srec
5296 The 'objcopy' does not understand the information in the U-Boot
5297 image header, so the resulting S-Record file will be relative to
5298 address 0x00000000. To load it to a given address, you need to
5299 specify the target address as 'offset' parameter with the 'loads'
5302 Example: install the image to address 0x40100000 (which on the
5303 TQM8xxL is in the first Flash bank):
5305 => erase 40100000 401FFFFF
5311 ## Ready for S-Record download ...
5312 ~>examples/image.srec
5313 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5315 15989 15990 15991 15992
5316 [file transfer complete]
5318 ## Start Addr = 0x00000000
5321 You can check the success of the download using the 'iminfo' command;
5322 this includes a checksum verification so you can be sure no data
5323 corruption happened:
5327 ## Checking Image at 40100000 ...
5328 Image Name: 2.2.13 for initrd on TQM850L
5329 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5330 Data Size: 335725 Bytes = 327 kB = 0 MB
5331 Load Address: 00000000
5332 Entry Point: 0000000c
5333 Verifying Checksum ... OK
5339 The "bootm" command is used to boot an application that is stored in
5340 memory (RAM or Flash). In case of a Linux kernel image, the contents
5341 of the "bootargs" environment variable is passed to the kernel as
5342 parameters. You can check and modify this variable using the
5343 "printenv" and "setenv" commands:
5346 => printenv bootargs
5347 bootargs=root=/dev/ram
5349 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5351 => printenv bootargs
5352 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5355 ## Booting Linux kernel at 40020000 ...
5356 Image Name: 2.2.13 for NFS on TQM850L
5357 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5358 Data Size: 381681 Bytes = 372 kB = 0 MB
5359 Load Address: 00000000
5360 Entry Point: 0000000c
5361 Verifying Checksum ... OK
5362 Uncompressing Kernel Image ... OK
5363 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
5364 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5365 time_init: decrementer frequency = 187500000/60
5366 Calibrating delay loop... 49.77 BogoMIPS
5367 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5370 If you want to boot a Linux kernel with initial RAM disk, you pass
5371 the memory addresses of both the kernel and the initrd image (PPBCOOT
5372 format!) to the "bootm" command:
5374 => imi 40100000 40200000
5376 ## Checking Image at 40100000 ...
5377 Image Name: 2.2.13 for initrd on TQM850L
5378 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5379 Data Size: 335725 Bytes = 327 kB = 0 MB
5380 Load Address: 00000000
5381 Entry Point: 0000000c
5382 Verifying Checksum ... OK
5384 ## Checking Image at 40200000 ...
5385 Image Name: Simple Ramdisk Image
5386 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5387 Data Size: 566530 Bytes = 553 kB = 0 MB
5388 Load Address: 00000000
5389 Entry Point: 00000000
5390 Verifying Checksum ... OK
5392 => bootm 40100000 40200000
5393 ## Booting Linux kernel at 40100000 ...
5394 Image Name: 2.2.13 for initrd on TQM850L
5395 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5396 Data Size: 335725 Bytes = 327 kB = 0 MB
5397 Load Address: 00000000
5398 Entry Point: 0000000c
5399 Verifying Checksum ... OK
5400 Uncompressing Kernel Image ... OK
5401 ## Loading RAMDisk Image at 40200000 ...
5402 Image Name: Simple Ramdisk Image
5403 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5404 Data Size: 566530 Bytes = 553 kB = 0 MB
5405 Load Address: 00000000
5406 Entry Point: 00000000
5407 Verifying Checksum ... OK
5408 Loading Ramdisk ... OK
5409 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
5410 Boot arguments: root=/dev/ram
5411 time_init: decrementer frequency = 187500000/60
5412 Calibrating delay loop... 49.77 BogoMIPS
5414 RAMDISK: Compressed image found at block 0
5415 VFS: Mounted root (ext2 filesystem).
5419 Boot Linux and pass a flat device tree:
5422 First, U-Boot must be compiled with the appropriate defines. See the section
5423 titled "Linux Kernel Interface" above for a more in depth explanation. The
5424 following is an example of how to start a kernel and pass an updated
5430 oft=oftrees/mpc8540ads.dtb
5431 => tftp $oftaddr $oft
5432 Speed: 1000, full duplex
5434 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5435 Filename 'oftrees/mpc8540ads.dtb'.
5436 Load address: 0x300000
5439 Bytes transferred = 4106 (100a hex)
5440 => tftp $loadaddr $bootfile
5441 Speed: 1000, full duplex
5443 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5445 Load address: 0x200000
5446 Loading:############
5448 Bytes transferred = 1029407 (fb51f hex)
5453 => bootm $loadaddr - $oftaddr
5454 ## Booting image at 00200000 ...
5455 Image Name: Linux-2.6.17-dirty
5456 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5457 Data Size: 1029343 Bytes = 1005.2 kB
5458 Load Address: 00000000
5459 Entry Point: 00000000
5460 Verifying Checksum ... OK
5461 Uncompressing Kernel Image ... OK
5462 Booting using flat device tree at 0x300000
5463 Using MPC85xx ADS machine description
5464 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5468 More About U-Boot Image Types:
5469 ------------------------------
5471 U-Boot supports the following image types:
5473 "Standalone Programs" are directly runnable in the environment
5474 provided by U-Boot; it is expected that (if they behave
5475 well) you can continue to work in U-Boot after return from
5476 the Standalone Program.
5477 "OS Kernel Images" are usually images of some Embedded OS which
5478 will take over control completely. Usually these programs
5479 will install their own set of exception handlers, device
5480 drivers, set up the MMU, etc. - this means, that you cannot
5481 expect to re-enter U-Boot except by resetting the CPU.
5482 "RAMDisk Images" are more or less just data blocks, and their
5483 parameters (address, size) are passed to an OS kernel that is
5485 "Multi-File Images" contain several images, typically an OS
5486 (Linux) kernel image and one or more data images like
5487 RAMDisks. This construct is useful for instance when you want
5488 to boot over the network using BOOTP etc., where the boot
5489 server provides just a single image file, but you want to get
5490 for instance an OS kernel and a RAMDisk image.
5492 "Multi-File Images" start with a list of image sizes, each
5493 image size (in bytes) specified by an "uint32_t" in network
5494 byte order. This list is terminated by an "(uint32_t)0".
5495 Immediately after the terminating 0 follow the images, one by
5496 one, all aligned on "uint32_t" boundaries (size rounded up to
5497 a multiple of 4 bytes).
5499 "Firmware Images" are binary images containing firmware (like
5500 U-Boot or FPGA images) which usually will be programmed to
5503 "Script files" are command sequences that will be executed by
5504 U-Boot's command interpreter; this feature is especially
5505 useful when you configure U-Boot to use a real shell (hush)
5506 as command interpreter.
5508 Booting the Linux zImage:
5509 -------------------------
5511 On some platforms, it's possible to boot Linux zImage. This is done
5512 using the "bootz" command. The syntax of "bootz" command is the same
5513 as the syntax of "bootm" command.
5515 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5516 kernel with raw initrd images. The syntax is slightly different, the
5517 address of the initrd must be augmented by it's size, in the following
5518 format: "<initrd addres>:<initrd size>".
5524 One of the features of U-Boot is that you can dynamically load and
5525 run "standalone" applications, which can use some resources of
5526 U-Boot like console I/O functions or interrupt services.
5528 Two simple examples are included with the sources:
5533 'examples/hello_world.c' contains a small "Hello World" Demo
5534 application; it is automatically compiled when you build U-Boot.
5535 It's configured to run at address 0x00040004, so you can play with it
5539 ## Ready for S-Record download ...
5540 ~>examples/hello_world.srec
5541 1 2 3 4 5 6 7 8 9 10 11 ...
5542 [file transfer complete]
5544 ## Start Addr = 0x00040004
5546 => go 40004 Hello World! This is a test.
5547 ## Starting application at 0x00040004 ...
5558 Hit any key to exit ...
5560 ## Application terminated, rc = 0x0
5562 Another example, which demonstrates how to register a CPM interrupt
5563 handler with the U-Boot code, can be found in 'examples/timer.c'.
5564 Here, a CPM timer is set up to generate an interrupt every second.
5565 The interrupt service routine is trivial, just printing a '.'
5566 character, but this is just a demo program. The application can be
5567 controlled by the following keys:
5569 ? - print current values og the CPM Timer registers
5570 b - enable interrupts and start timer
5571 e - stop timer and disable interrupts
5572 q - quit application
5575 ## Ready for S-Record download ...
5576 ~>examples/timer.srec
5577 1 2 3 4 5 6 7 8 9 10 11 ...
5578 [file transfer complete]
5580 ## Start Addr = 0x00040004
5583 ## Starting application at 0x00040004 ...
5586 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5589 [q, b, e, ?] Set interval 1000000 us
5592 [q, b, e, ?] ........
5593 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5596 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5599 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5602 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5604 [q, b, e, ?] ...Stopping timer
5606 [q, b, e, ?] ## Application terminated, rc = 0x0
5612 Over time, many people have reported problems when trying to use the
5613 "minicom" terminal emulation program for serial download. I (wd)
5614 consider minicom to be broken, and recommend not to use it. Under
5615 Unix, I recommend to use C-Kermit for general purpose use (and
5616 especially for kermit binary protocol download ("loadb" command), and
5617 use "cu" for S-Record download ("loads" command). See
5618 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5619 for help with kermit.
5622 Nevertheless, if you absolutely want to use it try adding this
5623 configuration to your "File transfer protocols" section:
5625 Name Program Name U/D FullScr IO-Red. Multi
5626 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5627 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5633 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5634 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5636 Building requires a cross environment; it is known to work on
5637 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5638 need gmake since the Makefiles are not compatible with BSD make).
5639 Note that the cross-powerpc package does not install include files;
5640 attempting to build U-Boot will fail because <machine/ansi.h> is
5641 missing. This file has to be installed and patched manually:
5643 # cd /usr/pkg/cross/powerpc-netbsd/include
5645 # ln -s powerpc machine
5646 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5647 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5649 Native builds *don't* work due to incompatibilities between native
5650 and U-Boot include files.
5652 Booting assumes that (the first part of) the image booted is a
5653 stage-2 loader which in turn loads and then invokes the kernel
5654 proper. Loader sources will eventually appear in the NetBSD source
5655 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5656 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5659 Implementation Internals:
5660 =========================
5662 The following is not intended to be a complete description of every
5663 implementation detail. However, it should help to understand the
5664 inner workings of U-Boot and make it easier to port it to custom
5668 Initial Stack, Global Data:
5669 ---------------------------
5671 The implementation of U-Boot is complicated by the fact that U-Boot
5672 starts running out of ROM (flash memory), usually without access to
5673 system RAM (because the memory controller is not initialized yet).
5674 This means that we don't have writable Data or BSS segments, and BSS
5675 is not initialized as zero. To be able to get a C environment working
5676 at all, we have to allocate at least a minimal stack. Implementation
5677 options for this are defined and restricted by the CPU used: Some CPU
5678 models provide on-chip memory (like the IMMR area on MPC8xx and
5679 MPC826x processors), on others (parts of) the data cache can be
5680 locked as (mis-) used as memory, etc.
5682 Chris Hallinan posted a good summary of these issues to the
5683 U-Boot mailing list:
5685 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5686 From: "Chris Hallinan" <clh@net1plus.com>
5687 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5690 Correct me if I'm wrong, folks, but the way I understand it
5691 is this: Using DCACHE as initial RAM for Stack, etc, does not
5692 require any physical RAM backing up the cache. The cleverness
5693 is that the cache is being used as a temporary supply of
5694 necessary storage before the SDRAM controller is setup. It's
5695 beyond the scope of this list to explain the details, but you
5696 can see how this works by studying the cache architecture and
5697 operation in the architecture and processor-specific manuals.
5699 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5700 is another option for the system designer to use as an
5701 initial stack/RAM area prior to SDRAM being available. Either
5702 option should work for you. Using CS 4 should be fine if your
5703 board designers haven't used it for something that would
5704 cause you grief during the initial boot! It is frequently not
5707 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5708 with your processor/board/system design. The default value
5709 you will find in any recent u-boot distribution in
5710 walnut.h should work for you. I'd set it to a value larger
5711 than your SDRAM module. If you have a 64MB SDRAM module, set
5712 it above 400_0000. Just make sure your board has no resources
5713 that are supposed to respond to that address! That code in
5714 start.S has been around a while and should work as is when
5715 you get the config right.
5720 It is essential to remember this, since it has some impact on the C
5721 code for the initialization procedures:
5723 * Initialized global data (data segment) is read-only. Do not attempt
5726 * Do not use any uninitialized global data (or implicitely initialized
5727 as zero data - BSS segment) at all - this is undefined, initiali-
5728 zation is performed later (when relocating to RAM).
5730 * Stack space is very limited. Avoid big data buffers or things like
5733 Having only the stack as writable memory limits means we cannot use
5734 normal global data to share information beween the code. But it
5735 turned out that the implementation of U-Boot can be greatly
5736 simplified by making a global data structure (gd_t) available to all
5737 functions. We could pass a pointer to this data as argument to _all_
5738 functions, but this would bloat the code. Instead we use a feature of
5739 the GCC compiler (Global Register Variables) to share the data: we
5740 place a pointer (gd) to the global data into a register which we
5741 reserve for this purpose.
5743 When choosing a register for such a purpose we are restricted by the
5744 relevant (E)ABI specifications for the current architecture, and by
5745 GCC's implementation.
5747 For PowerPC, the following registers have specific use:
5749 R2: reserved for system use
5750 R3-R4: parameter passing and return values
5751 R5-R10: parameter passing
5752 R13: small data area pointer
5756 (U-Boot also uses R12 as internal GOT pointer. r12
5757 is a volatile register so r12 needs to be reset when
5758 going back and forth between asm and C)
5760 ==> U-Boot will use R2 to hold a pointer to the global data
5762 Note: on PPC, we could use a static initializer (since the
5763 address of the global data structure is known at compile time),
5764 but it turned out that reserving a register results in somewhat
5765 smaller code - although the code savings are not that big (on
5766 average for all boards 752 bytes for the whole U-Boot image,
5767 624 text + 127 data).
5769 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5770 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5772 ==> U-Boot will use P3 to hold a pointer to the global data
5774 On ARM, the following registers are used:
5776 R0: function argument word/integer result
5777 R1-R3: function argument word
5778 R9: platform specific
5779 R10: stack limit (used only if stack checking is enabled)
5780 R11: argument (frame) pointer
5781 R12: temporary workspace
5784 R15: program counter
5786 ==> U-Boot will use R9 to hold a pointer to the global data
5788 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5790 On Nios II, the ABI is documented here:
5791 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5793 ==> U-Boot will use gp to hold a pointer to the global data
5795 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5796 to access small data sections, so gp is free.
5798 On NDS32, the following registers are used:
5800 R0-R1: argument/return
5802 R15: temporary register for assembler
5803 R16: trampoline register
5804 R28: frame pointer (FP)
5805 R29: global pointer (GP)
5806 R30: link register (LP)
5807 R31: stack pointer (SP)
5808 PC: program counter (PC)
5810 ==> U-Boot will use R10 to hold a pointer to the global data
5812 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5813 or current versions of GCC may "optimize" the code too much.
5818 U-Boot runs in system state and uses physical addresses, i.e. the
5819 MMU is not used either for address mapping nor for memory protection.
5821 The available memory is mapped to fixed addresses using the memory
5822 controller. In this process, a contiguous block is formed for each
5823 memory type (Flash, SDRAM, SRAM), even when it consists of several
5824 physical memory banks.
5826 U-Boot is installed in the first 128 kB of the first Flash bank (on
5827 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5828 booting and sizing and initializing DRAM, the code relocates itself
5829 to the upper end of DRAM. Immediately below the U-Boot code some
5830 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5831 configuration setting]. Below that, a structure with global Board
5832 Info data is placed, followed by the stack (growing downward).
5834 Additionally, some exception handler code is copied to the low 8 kB
5835 of DRAM (0x00000000 ... 0x00001FFF).
5837 So a typical memory configuration with 16 MB of DRAM could look like
5840 0x0000 0000 Exception Vector code
5843 0x0000 2000 Free for Application Use
5849 0x00FB FF20 Monitor Stack (Growing downward)
5850 0x00FB FFAC Board Info Data and permanent copy of global data
5851 0x00FC 0000 Malloc Arena
5854 0x00FE 0000 RAM Copy of Monitor Code
5855 ... eventually: LCD or video framebuffer
5856 ... eventually: pRAM (Protected RAM - unchanged by reset)
5857 0x00FF FFFF [End of RAM]
5860 System Initialization:
5861 ----------------------
5863 In the reset configuration, U-Boot starts at the reset entry point
5864 (on most PowerPC systems at address 0x00000100). Because of the reset
5865 configuration for CS0# this is a mirror of the onboard Flash memory.
5866 To be able to re-map memory U-Boot then jumps to its link address.
5867 To be able to implement the initialization code in C, a (small!)
5868 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5869 which provide such a feature like MPC8xx or MPC8260), or in a locked
5870 part of the data cache. After that, U-Boot initializes the CPU core,
5871 the caches and the SIU.
5873 Next, all (potentially) available memory banks are mapped using a
5874 preliminary mapping. For example, we put them on 512 MB boundaries
5875 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5876 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5877 programmed for SDRAM access. Using the temporary configuration, a
5878 simple memory test is run that determines the size of the SDRAM
5881 When there is more than one SDRAM bank, and the banks are of
5882 different size, the largest is mapped first. For equal size, the first
5883 bank (CS2#) is mapped first. The first mapping is always for address
5884 0x00000000, with any additional banks following immediately to create
5885 contiguous memory starting from 0.
5887 Then, the monitor installs itself at the upper end of the SDRAM area
5888 and allocates memory for use by malloc() and for the global Board
5889 Info data; also, the exception vector code is copied to the low RAM
5890 pages, and the final stack is set up.
5892 Only after this relocation will you have a "normal" C environment;
5893 until that you are restricted in several ways, mostly because you are
5894 running from ROM, and because the code will have to be relocated to a
5898 U-Boot Porting Guide:
5899 ----------------------
5901 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5905 int main(int argc, char *argv[])
5907 sighandler_t no_more_time;
5909 signal(SIGALRM, no_more_time);
5910 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5912 if (available_money > available_manpower) {
5913 Pay consultant to port U-Boot;
5917 Download latest U-Boot source;
5919 Subscribe to u-boot mailing list;
5922 email("Hi, I am new to U-Boot, how do I get started?");
5925 Read the README file in the top level directory;
5926 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5927 Read applicable doc/*.README;
5928 Read the source, Luke;
5929 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5932 if (available_money > toLocalCurrency ($2500))
5935 Add a lot of aggravation and time;
5937 if (a similar board exists) { /* hopefully... */
5938 cp -a board/<similar> board/<myboard>
5939 cp include/configs/<similar>.h include/configs/<myboard>.h
5941 Create your own board support subdirectory;
5942 Create your own board include/configs/<myboard>.h file;
5944 Edit new board/<myboard> files
5945 Edit new include/configs/<myboard>.h
5950 Add / modify source code;
5954 email("Hi, I am having problems...");
5956 Send patch file to the U-Boot email list;
5957 if (reasonable critiques)
5958 Incorporate improvements from email list code review;
5960 Defend code as written;
5966 void no_more_time (int sig)
5975 All contributions to U-Boot should conform to the Linux kernel
5976 coding style; see the file "Documentation/CodingStyle" and the script
5977 "scripts/Lindent" in your Linux kernel source directory.
5979 Source files originating from a different project (for example the
5980 MTD subsystem) are generally exempt from these guidelines and are not
5981 reformated to ease subsequent migration to newer versions of those
5984 Please note that U-Boot is implemented in C (and to some small parts in
5985 Assembler); no C++ is used, so please do not use C++ style comments (//)
5988 Please also stick to the following formatting rules:
5989 - remove any trailing white space
5990 - use TAB characters for indentation and vertical alignment, not spaces
5991 - make sure NOT to use DOS '\r\n' line feeds
5992 - do not add more than 2 consecutive empty lines to source files
5993 - do not add trailing empty lines to source files
5995 Submissions which do not conform to the standards may be returned
5996 with a request to reformat the changes.
6002 Since the number of patches for U-Boot is growing, we need to
6003 establish some rules. Submissions which do not conform to these rules
6004 may be rejected, even when they contain important and valuable stuff.
6006 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6008 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6009 see http://lists.denx.de/mailman/listinfo/u-boot
6011 When you send a patch, please include the following information with
6014 * For bug fixes: a description of the bug and how your patch fixes
6015 this bug. Please try to include a way of demonstrating that the
6016 patch actually fixes something.
6018 * For new features: a description of the feature and your
6021 * A CHANGELOG entry as plaintext (separate from the patch)
6023 * For major contributions, your entry to the CREDITS file
6025 * When you add support for a new board, don't forget to add a
6026 maintainer e-mail address to the boards.cfg file, too.
6028 * If your patch adds new configuration options, don't forget to
6029 document these in the README file.
6031 * The patch itself. If you are using git (which is *strongly*
6032 recommended) you can easily generate the patch using the
6033 "git format-patch". If you then use "git send-email" to send it to
6034 the U-Boot mailing list, you will avoid most of the common problems
6035 with some other mail clients.
6037 If you cannot use git, use "diff -purN OLD NEW". If your version of
6038 diff does not support these options, then get the latest version of
6041 The current directory when running this command shall be the parent
6042 directory of the U-Boot source tree (i. e. please make sure that
6043 your patch includes sufficient directory information for the
6046 We prefer patches as plain text. MIME attachments are discouraged,
6047 and compressed attachments must not be used.
6049 * If one logical set of modifications affects or creates several
6050 files, all these changes shall be submitted in a SINGLE patch file.
6052 * Changesets that contain different, unrelated modifications shall be
6053 submitted as SEPARATE patches, one patch per changeset.
6058 * Before sending the patch, run the MAKEALL script on your patched
6059 source tree and make sure that no errors or warnings are reported
6060 for any of the boards.
6062 * Keep your modifications to the necessary minimum: A patch
6063 containing several unrelated changes or arbitrary reformats will be
6064 returned with a request to re-formatting / split it.
6066 * If you modify existing code, make sure that your new code does not
6067 add to the memory footprint of the code ;-) Small is beautiful!
6068 When adding new features, these should compile conditionally only
6069 (using #ifdef), and the resulting code with the new feature
6070 disabled must not need more memory than the old code without your
6073 * Remember that there is a size limit of 100 kB per message on the
6074 u-boot mailing list. Bigger patches will be moderated. If they are
6075 reasonable and not too big, they will be acknowledged. But patches
6076 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob