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 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_config".
257 Example: For a TQM823L module type:
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_config". And also configure the cogent
264 directory according to the instructions in cogent/README.
267 Configuration Options:
268 ----------------------
270 Configuration depends on the combination of board and CPU type; all
271 such information is kept in a configuration file
272 "include/configs/<board_name>.h".
274 Example: For a TQM823L module, all configuration settings are in
275 "include/configs/TQM823L.h".
278 Many of the options are named exactly as the corresponding Linux
279 kernel configuration options. The intention is to make it easier to
280 build a config tool - later.
283 The following options need to be configured:
285 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
287 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
289 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
290 Define exactly one, e.g. CONFIG_ATSTK1002
292 - CPU Module Type: (if CONFIG_COGENT is defined)
293 Define exactly one of
295 --- FIXME --- not tested yet:
296 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
297 CONFIG_CMA287_23, CONFIG_CMA287_50
299 - Motherboard Type: (if CONFIG_COGENT is defined)
300 Define exactly one of
301 CONFIG_CMA101, CONFIG_CMA102
303 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
304 Define one or more of
307 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
308 Define one or more of
309 CONFIG_LCD_HEARTBEAT - update a character position on
310 the LCD display every second with
313 - Board flavour: (if CONFIG_MPC8260ADS is defined)
316 CONFIG_SYS_8260ADS - original MPC8260ADS
317 CONFIG_SYS_8266ADS - MPC8266ADS
318 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
319 CONFIG_SYS_8272ADS - MPC8272ADS
321 - Marvell Family Member
322 CONFIG_SYS_MVFS - define it if you want to enable
323 multiple fs option at one time
324 for marvell soc family
326 - MPC824X Family Member (if CONFIG_MPC824X is defined)
327 Define exactly one of
328 CONFIG_MPC8240, CONFIG_MPC8245
330 - 8xx CPU Options: (if using an MPC8xx CPU)
331 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
332 get_gclk_freq() cannot work
333 e.g. if there is no 32KHz
334 reference PIT/RTC clock
335 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
338 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
339 CONFIG_SYS_8xx_CPUCLK_MIN
340 CONFIG_SYS_8xx_CPUCLK_MAX
341 CONFIG_8xx_CPUCLK_DEFAULT
342 See doc/README.MPC866
344 CONFIG_SYS_MEASURE_CPUCLK
346 Define this to measure the actual CPU clock instead
347 of relying on the correctness of the configured
348 values. Mostly useful for board bringup to make sure
349 the PLL is locked at the intended frequency. Note
350 that this requires a (stable) reference clock (32 kHz
351 RTC clock or CONFIG_SYS_8XX_XIN)
353 CONFIG_SYS_DELAYED_ICACHE
355 Define this option if you want to enable the
356 ICache only when Code runs from RAM.
361 Specifies that the core is a 64-bit PowerPC implementation (implements
362 the "64" category of the Power ISA). This is necessary for ePAPR
363 compliance, among other possible reasons.
365 CONFIG_SYS_FSL_TBCLK_DIV
367 Defines the core time base clock divider ratio compared to the
368 system clock. On most PQ3 devices this is 8, on newer QorIQ
369 devices it can be 16 or 32. The ratio varies from SoC to Soc.
371 CONFIG_SYS_FSL_PCIE_COMPAT
373 Defines the string to utilize when trying to match PCIe device
374 tree nodes for the given platform.
376 CONFIG_SYS_PPC_E500_DEBUG_TLB
378 Enables a temporary TLB entry to be used during boot to work
379 around limitations in e500v1 and e500v2 external debugger
380 support. This reduces the portions of the boot code where
381 breakpoints and single stepping do not work. The value of this
382 symbol should be set to the TLB1 entry to be used for this
385 CONFIG_SYS_FSL_ERRATUM_A004510
387 Enables a workaround for erratum A004510. If set,
388 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
389 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
391 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
392 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
394 Defines one or two SoC revisions (low 8 bits of SVR)
395 for which the A004510 workaround should be applied.
397 The rest of SVR is either not relevant to the decision
398 of whether the erratum is present (e.g. p2040 versus
399 p2041) or is implied by the build target, which controls
400 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
402 See Freescale App Note 4493 for more information about
405 CONFIG_A003399_NOR_WORKAROUND
406 Enables a workaround for IFC erratum A003399. It is only
407 requred during NOR boot.
409 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
411 This is the value to write into CCSR offset 0x18600
412 according to the A004510 workaround.
414 CONFIG_SYS_FSL_DSP_DDR_ADDR
415 This value denotes start offset of DDR memory which is
416 connected exclusively to the DSP cores.
418 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
419 This value denotes start offset of M2 memory
420 which is directly connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
423 This value denotes start offset of M3 memory which is directly
424 connected to the DSP core.
426 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
427 This value denotes start offset of DSP CCSR space.
429 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
430 Single Source Clock is clocking mode present in some of FSL SoC's.
431 In this mode, a single differential clock is used to supply
432 clocks to the sysclock, ddrclock and usbclock.
434 - Generic CPU options:
435 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
437 Defines the endianess of the CPU. Implementation of those
438 values is arch specific.
441 Freescale DDR driver in use. This type of DDR controller is
442 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
445 CONFIG_SYS_FSL_DDR_ADDR
446 Freescale DDR memory-mapped register base.
448 CONFIG_SYS_FSL_DDR_EMU
449 Specify emulator support for DDR. Some DDR features such as
450 deskew training are not available.
452 CONFIG_SYS_FSL_DDRC_GEN1
453 Freescale DDR1 controller.
455 CONFIG_SYS_FSL_DDRC_GEN2
456 Freescale DDR2 controller.
458 CONFIG_SYS_FSL_DDRC_GEN3
459 Freescale DDR3 controller.
461 CONFIG_SYS_FSL_DDRC_ARM_GEN3
462 Freescale DDR3 controller for ARM-based SoCs.
465 Board config to use DDR1. It can be enabled for SoCs with
466 Freescale DDR1 or DDR2 controllers, depending on the board
470 Board config to use DDR2. It can be eanbeld for SoCs with
471 Freescale DDR2 or DDR3 controllers, depending on the board
475 Board config to use DDR3. It can be enabled for SoCs with
476 Freescale DDR3 controllers.
478 CONFIG_SYS_FSL_IFC_BE
479 Defines the IFC controller register space as Big Endian
481 CONFIG_SYS_FSL_IFC_LE
482 Defines the IFC controller register space as Little Endian
484 CONFIG_SYS_FSL_PBL_PBI
485 It enables addition of RCW (Power on reset configuration) in built image.
486 Please refer doc/README.pblimage for more details
488 CONFIG_SYS_FSL_PBL_RCW
489 It adds PBI(pre-boot instructions) commands in u-boot build image.
490 PBI commands can be used to configure SoC before it starts the execution.
491 Please refer doc/README.pblimage for more details
493 CONFIG_SYS_FSL_DDR_BE
494 Defines the DDR controller register space as Big Endian
496 CONFIG_SYS_FSL_DDR_LE
497 Defines the DDR controller register space as Little Endian
499 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
500 Physical address from the view of DDR controllers. It is the
501 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
502 it could be different for ARM SoCs.
504 CONFIG_SYS_FSL_DDR_INTLV_256B
505 DDR controller interleaving on 256-byte. This is a special
506 interleaving mode, handled by Dickens for Freescale layerscape
509 - Intel Monahans options:
510 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
512 Defines the Monahans run mode to oscillator
513 ratio. Valid values are 8, 16, 24, 31. The core
514 frequency is this value multiplied by 13 MHz.
516 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
518 Defines the Monahans turbo mode to oscillator
519 ratio. Valid values are 1 (default if undefined) and
520 2. The core frequency as calculated above is multiplied
524 CONFIG_SYS_INIT_SP_OFFSET
526 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
527 pointer. This is needed for the temporary stack before
530 CONFIG_SYS_MIPS_CACHE_MODE
532 Cache operation mode for the MIPS CPU.
533 See also arch/mips/include/asm/mipsregs.h.
535 CONF_CM_CACHABLE_NO_WA
538 CONF_CM_CACHABLE_NONCOHERENT
542 CONF_CM_CACHABLE_ACCELERATED
544 CONFIG_SYS_XWAY_EBU_BOOTCFG
546 Special option for Lantiq XWAY SoCs for booting from NOR flash.
547 See also arch/mips/cpu/mips32/start.S.
549 CONFIG_XWAY_SWAP_BYTES
551 Enable compilation of tools/xway-swap-bytes needed for Lantiq
552 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
553 be swapped if a flash programmer is used.
556 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
558 Select high exception vectors of the ARM core, e.g., do not
559 clear the V bit of the c1 register of CP15.
561 CONFIG_SYS_THUMB_BUILD
563 Use this flag to build U-Boot using the Thumb instruction
564 set for ARM architectures. Thumb instruction set provides
565 better code density. For ARM architectures that support
566 Thumb2 this flag will result in Thumb2 code generated by
569 CONFIG_ARM_ERRATA_716044
570 CONFIG_ARM_ERRATA_742230
571 CONFIG_ARM_ERRATA_743622
572 CONFIG_ARM_ERRATA_751472
573 CONFIG_ARM_ERRATA_794072
574 CONFIG_ARM_ERRATA_761320
576 If set, the workarounds for these ARM errata are applied early
577 during U-Boot startup. Note that these options force the
578 workarounds to be applied; no CPU-type/version detection
579 exists, unlike the similar options in the Linux kernel. Do not
580 set these options unless they apply!
585 The frequency of the timer returned by get_timer().
586 get_timer() must operate in milliseconds and this CONFIG
587 option must be set to 1000.
589 - Linux Kernel Interface:
592 U-Boot stores all clock information in Hz
593 internally. For binary compatibility with older Linux
594 kernels (which expect the clocks passed in the
595 bd_info data to be in MHz) the environment variable
596 "clocks_in_mhz" can be defined so that U-Boot
597 converts clock data to MHZ before passing it to the
599 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
600 "clocks_in_mhz=1" is automatically included in the
603 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
605 When transferring memsize parameter to linux, some versions
606 expect it to be in bytes, others in MB.
607 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
611 New kernel versions are expecting firmware settings to be
612 passed using flattened device trees (based on open firmware
616 * New libfdt-based support
617 * Adds the "fdt" command
618 * The bootm command automatically updates the fdt
620 OF_CPU - The proper name of the cpus node (only required for
621 MPC512X and MPC5xxx based boards).
622 OF_SOC - The proper name of the soc node (only required for
623 MPC512X and MPC5xxx based boards).
624 OF_TBCLK - The timebase frequency.
625 OF_STDOUT_PATH - The path to the console device
627 boards with QUICC Engines require OF_QE to set UCC MAC
630 CONFIG_OF_BOARD_SETUP
632 Board code has addition modification that it wants to make
633 to the flat device tree before handing it off to the kernel
637 This define fills in the correct boot CPU in the boot
638 param header, the default value is zero if undefined.
642 U-Boot can detect if an IDE device is present or not.
643 If not, and this new config option is activated, U-Boot
644 removes the ATA node from the DTS before booting Linux,
645 so the Linux IDE driver does not probe the device and
646 crash. This is needed for buggy hardware (uc101) where
647 no pull down resistor is connected to the signal IDE5V_DD7.
649 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
651 This setting is mandatory for all boards that have only one
652 machine type and must be used to specify the machine type
653 number as it appears in the ARM machine registry
654 (see http://www.arm.linux.org.uk/developer/machines/).
655 Only boards that have multiple machine types supported
656 in a single configuration file and the machine type is
657 runtime discoverable, do not have to use this setting.
659 - vxWorks boot parameters:
661 bootvx constructs a valid bootline using the following
662 environments variables: bootfile, ipaddr, serverip, hostname.
663 It loads the vxWorks image pointed bootfile.
665 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
666 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
667 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
668 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
670 CONFIG_SYS_VXWORKS_ADD_PARAMS
672 Add it at the end of the bootline. E.g "u=username pw=secret"
674 Note: If a "bootargs" environment is defined, it will overwride
675 the defaults discussed just above.
677 - Cache Configuration:
678 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
679 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
680 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
682 - Cache Configuration for ARM:
683 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
685 CONFIG_SYS_PL310_BASE - Physical base address of PL310
686 controller register space
691 Define this if you want support for Amba PrimeCell PL010 UARTs.
695 Define this if you want support for Amba PrimeCell PL011 UARTs.
699 If you have Amba PrimeCell PL011 UARTs, set this variable to
700 the clock speed of the UARTs.
704 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
705 define this to a list of base addresses for each (supported)
706 port. See e.g. include/configs/versatile.h
708 CONFIG_PL011_SERIAL_RLCR
710 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
711 have separate receive and transmit line control registers. Set
712 this variable to initialize the extra register.
714 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
716 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
717 boot loader that has already initialized the UART. Define this
718 variable to flush the UART at init time.
722 Depending on board, define exactly one serial port
723 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
724 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
725 console by defining CONFIG_8xx_CONS_NONE
727 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
728 port routines must be defined elsewhere
729 (i.e. serial_init(), serial_getc(), ...)
732 Enables console device for a color framebuffer. Needs following
733 defines (cf. smiLynxEM, i8042)
734 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
736 VIDEO_HW_RECTFILL graphic chip supports
739 VIDEO_HW_BITBLT graphic chip supports
740 bit-blit (cf. smiLynxEM)
741 VIDEO_VISIBLE_COLS visible pixel columns
743 VIDEO_VISIBLE_ROWS visible pixel rows
744 VIDEO_PIXEL_SIZE bytes per pixel
745 VIDEO_DATA_FORMAT graphic data format
746 (0-5, cf. cfb_console.c)
747 VIDEO_FB_ADRS framebuffer address
748 VIDEO_KBD_INIT_FCT keyboard int fct
749 (i.e. i8042_kbd_init())
750 VIDEO_TSTC_FCT test char fct
752 VIDEO_GETC_FCT get char fct
754 CONFIG_CONSOLE_CURSOR cursor drawing on/off
755 (requires blink timer
757 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
758 CONFIG_CONSOLE_TIME display time/date info in
760 (requires CONFIG_CMD_DATE)
761 CONFIG_VIDEO_LOGO display Linux logo in
763 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
764 linux_logo.h for logo.
765 Requires CONFIG_VIDEO_LOGO
766 CONFIG_CONSOLE_EXTRA_INFO
767 additional board info beside
770 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
771 a limited number of ANSI escape sequences (cursor control,
772 erase functions and limited graphics rendition control).
774 When CONFIG_CFB_CONSOLE is defined, video console is
775 default i/o. Serial console can be forced with
776 environment 'console=serial'.
778 When CONFIG_SILENT_CONSOLE is defined, all console
779 messages (by U-Boot and Linux!) can be silenced with
780 the "silent" environment variable. See
781 doc/README.silent for more information.
783 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
785 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
789 CONFIG_BAUDRATE - in bps
790 Select one of the baudrates listed in
791 CONFIG_SYS_BAUDRATE_TABLE, see below.
792 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
794 - Console Rx buffer length
795 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
796 the maximum receive buffer length for the SMC.
797 This option is actual only for 82xx and 8xx possible.
798 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
799 must be defined, to setup the maximum idle timeout for
802 - Pre-Console Buffer:
803 Prior to the console being initialised (i.e. serial UART
804 initialised etc) all console output is silently discarded.
805 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
806 buffer any console messages prior to the console being
807 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
808 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
809 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
810 bytes are output before the console is initialised, the
811 earlier bytes are discarded.
813 'Sane' compilers will generate smaller code if
814 CONFIG_PRE_CON_BUF_SZ is a power of 2
816 - Safe printf() functions
817 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
818 the printf() functions. These are defined in
819 include/vsprintf.h and include snprintf(), vsnprintf() and
820 so on. Code size increase is approximately 300-500 bytes.
821 If this option is not given then these functions will
822 silently discard their buffer size argument - this means
823 you are not getting any overflow checking in this case.
825 - Boot Delay: CONFIG_BOOTDELAY - in seconds
826 Delay before automatically booting the default image;
827 set to -1 to disable autoboot.
828 set to -2 to autoboot with no delay and not check for abort
829 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
831 See doc/README.autoboot for these options that
832 work with CONFIG_BOOTDELAY. None are required.
833 CONFIG_BOOT_RETRY_TIME
834 CONFIG_BOOT_RETRY_MIN
835 CONFIG_AUTOBOOT_KEYED
836 CONFIG_AUTOBOOT_PROMPT
837 CONFIG_AUTOBOOT_DELAY_STR
838 CONFIG_AUTOBOOT_STOP_STR
839 CONFIG_AUTOBOOT_DELAY_STR2
840 CONFIG_AUTOBOOT_STOP_STR2
841 CONFIG_ZERO_BOOTDELAY_CHECK
842 CONFIG_RESET_TO_RETRY
846 Only needed when CONFIG_BOOTDELAY is enabled;
847 define a command string that is automatically executed
848 when no character is read on the console interface
849 within "Boot Delay" after reset.
852 This can be used to pass arguments to the bootm
853 command. The value of CONFIG_BOOTARGS goes into the
854 environment value "bootargs".
856 CONFIG_RAMBOOT and CONFIG_NFSBOOT
857 The value of these goes into the environment as
858 "ramboot" and "nfsboot" respectively, and can be used
859 as a convenience, when switching between booting from
863 CONFIG_BOOTCOUNT_LIMIT
864 Implements a mechanism for detecting a repeating reboot
866 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
869 If no softreset save registers are found on the hardware
870 "bootcount" is stored in the environment. To prevent a
871 saveenv on all reboots, the environment variable
872 "upgrade_available" is used. If "upgrade_available" is
873 0, "bootcount" is always 0, if "upgrade_available" is
874 1 "bootcount" is incremented in the environment.
875 So the Userspace Applikation must set the "upgrade_available"
876 and "bootcount" variable to 0, if a boot was successfully.
881 When this option is #defined, the existence of the
882 environment variable "preboot" will be checked
883 immediately before starting the CONFIG_BOOTDELAY
884 countdown and/or running the auto-boot command resp.
885 entering interactive mode.
887 This feature is especially useful when "preboot" is
888 automatically generated or modified. For an example
889 see the LWMON board specific code: here "preboot" is
890 modified when the user holds down a certain
891 combination of keys on the (special) keyboard when
894 - Serial Download Echo Mode:
896 If defined to 1, all characters received during a
897 serial download (using the "loads" command) are
898 echoed back. This might be needed by some terminal
899 emulations (like "cu"), but may as well just take
900 time on others. This setting #define's the initial
901 value of the "loads_echo" environment variable.
903 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
905 Select one of the baudrates listed in
906 CONFIG_SYS_BAUDRATE_TABLE, see below.
909 Monitor commands can be included or excluded
910 from the build by using the #include files
911 <config_cmd_all.h> and #undef'ing unwanted
912 commands, or using <config_cmd_default.h>
913 and augmenting with additional #define's
916 The default command configuration includes all commands
917 except those marked below with a "*".
919 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
920 CONFIG_CMD_ASKENV * ask for env variable
921 CONFIG_CMD_BDI bdinfo
922 CONFIG_CMD_BEDBUG * Include BedBug Debugger
923 CONFIG_CMD_BMP * BMP support
924 CONFIG_CMD_BSP * Board specific commands
925 CONFIG_CMD_BOOTD bootd
926 CONFIG_CMD_CACHE * icache, dcache
927 CONFIG_CMD_CLK * clock command support
928 CONFIG_CMD_CONSOLE coninfo
929 CONFIG_CMD_CRC32 * crc32
930 CONFIG_CMD_DATE * support for RTC, date/time...
931 CONFIG_CMD_DHCP * DHCP support
932 CONFIG_CMD_DIAG * Diagnostics
933 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
934 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
935 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
936 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
937 CONFIG_CMD_DTT * Digital Therm and Thermostat
938 CONFIG_CMD_ECHO echo arguments
939 CONFIG_CMD_EDITENV edit env variable
940 CONFIG_CMD_EEPROM * EEPROM read/write support
941 CONFIG_CMD_ELF * bootelf, bootvx
942 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
943 CONFIG_CMD_ENV_FLAGS * display details about env flags
944 CONFIG_CMD_ENV_EXISTS * check existence of env variable
945 CONFIG_CMD_EXPORTENV * export the environment
946 CONFIG_CMD_EXT2 * ext2 command support
947 CONFIG_CMD_EXT4 * ext4 command support
948 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
949 that work for multiple fs types
950 CONFIG_CMD_SAVEENV saveenv
951 CONFIG_CMD_FDC * Floppy Disk Support
952 CONFIG_CMD_FAT * FAT command support
953 CONFIG_CMD_FLASH flinfo, erase, protect
954 CONFIG_CMD_FPGA FPGA device initialization support
955 CONFIG_CMD_FUSE * Device fuse support
956 CONFIG_CMD_GETTIME * Get time since boot
957 CONFIG_CMD_GO * the 'go' command (exec code)
958 CONFIG_CMD_GREPENV * search environment
959 CONFIG_CMD_HASH * calculate hash / digest
960 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
961 CONFIG_CMD_I2C * I2C serial bus support
962 CONFIG_CMD_IDE * IDE harddisk support
963 CONFIG_CMD_IMI iminfo
964 CONFIG_CMD_IMLS List all images found in NOR flash
965 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
966 CONFIG_CMD_IMMAP * IMMR dump support
967 CONFIG_CMD_IMPORTENV * import an environment
968 CONFIG_CMD_INI * import data from an ini file into the env
969 CONFIG_CMD_IRQ * irqinfo
970 CONFIG_CMD_ITEST Integer/string test of 2 values
971 CONFIG_CMD_JFFS2 * JFFS2 Support
972 CONFIG_CMD_KGDB * kgdb
973 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
974 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
976 CONFIG_CMD_LOADB loadb
977 CONFIG_CMD_LOADS loads
978 CONFIG_CMD_MD5SUM * print md5 message digest
979 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
980 CONFIG_CMD_MEMINFO * Display detailed memory information
981 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
983 CONFIG_CMD_MEMTEST * mtest
984 CONFIG_CMD_MISC Misc functions like sleep etc
985 CONFIG_CMD_MMC * MMC memory mapped support
986 CONFIG_CMD_MII * MII utility commands
987 CONFIG_CMD_MTDPARTS * MTD partition support
988 CONFIG_CMD_NAND * NAND support
989 CONFIG_CMD_NET bootp, tftpboot, rarpboot
990 CONFIG_CMD_NFS NFS support
991 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
992 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
993 CONFIG_CMD_PCI * pciinfo
994 CONFIG_CMD_PCMCIA * PCMCIA support
995 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
997 CONFIG_CMD_PORTIO * Port I/O
998 CONFIG_CMD_READ * Read raw data from partition
999 CONFIG_CMD_REGINFO * Register dump
1000 CONFIG_CMD_RUN run command in env variable
1001 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1002 CONFIG_CMD_SAVES * save S record dump
1003 CONFIG_CMD_SCSI * SCSI Support
1004 CONFIG_CMD_SDRAM * print SDRAM configuration information
1005 (requires CONFIG_CMD_I2C)
1006 CONFIG_CMD_SETGETDCR Support for DCR Register access
1008 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1009 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1010 (requires CONFIG_CMD_MEMORY)
1011 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1012 CONFIG_CMD_SOURCE "source" command Support
1013 CONFIG_CMD_SPI * SPI serial bus support
1014 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1015 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1016 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1017 CONFIG_CMD_TIMER * access to the system tick timer
1018 CONFIG_CMD_USB * USB support
1019 CONFIG_CMD_CDP * Cisco Discover Protocol support
1020 CONFIG_CMD_MFSL * Microblaze FSL support
1021 CONFIG_CMD_XIMG Load part of Multi Image
1022 CONFIG_CMD_UUID * Generate random UUID or GUID string
1024 EXAMPLE: If you want all functions except of network
1025 support you can write:
1027 #include "config_cmd_all.h"
1028 #undef CONFIG_CMD_NET
1031 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1033 Note: Don't enable the "icache" and "dcache" commands
1034 (configuration option CONFIG_CMD_CACHE) unless you know
1035 what you (and your U-Boot users) are doing. Data
1036 cache cannot be enabled on systems like the 8xx or
1037 8260 (where accesses to the IMMR region must be
1038 uncached), and it cannot be disabled on all other
1039 systems where we (mis-) use the data cache to hold an
1040 initial stack and some data.
1043 XXX - this list needs to get updated!
1045 - Regular expression support:
1047 If this variable is defined, U-Boot is linked against
1048 the SLRE (Super Light Regular Expression) library,
1049 which adds regex support to some commands, as for
1050 example "env grep" and "setexpr".
1054 If this variable is defined, U-Boot will use a device tree
1055 to configure its devices, instead of relying on statically
1056 compiled #defines in the board file. This option is
1057 experimental and only available on a few boards. The device
1058 tree is available in the global data as gd->fdt_blob.
1060 U-Boot needs to get its device tree from somewhere. This can
1061 be done using one of the two options below:
1064 If this variable is defined, U-Boot will embed a device tree
1065 binary in its image. This device tree file should be in the
1066 board directory and called <soc>-<board>.dts. The binary file
1067 is then picked up in board_init_f() and made available through
1068 the global data structure as gd->blob.
1071 If this variable is defined, U-Boot will build a device tree
1072 binary. It will be called u-boot.dtb. Architecture-specific
1073 code will locate it at run-time. Generally this works by:
1075 cat u-boot.bin u-boot.dtb >image.bin
1077 and in fact, U-Boot does this for you, creating a file called
1078 u-boot-dtb.bin which is useful in the common case. You can
1079 still use the individual files if you need something more
1084 If this variable is defined, it enables watchdog
1085 support for the SoC. There must be support in the SoC
1086 specific code for a watchdog. For the 8xx and 8260
1087 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1088 register. When supported for a specific SoC is
1089 available, then no further board specific code should
1090 be needed to use it.
1093 When using a watchdog circuitry external to the used
1094 SoC, then define this variable and provide board
1095 specific code for the "hw_watchdog_reset" function.
1098 CONFIG_VERSION_VARIABLE
1099 If this variable is defined, an environment variable
1100 named "ver" is created by U-Boot showing the U-Boot
1101 version as printed by the "version" command.
1102 Any change to this variable will be reverted at the
1107 When CONFIG_CMD_DATE is selected, the type of the RTC
1108 has to be selected, too. Define exactly one of the
1111 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1112 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1113 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1114 CONFIG_RTC_MC146818 - use MC146818 RTC
1115 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1116 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1117 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1118 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1119 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1120 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1121 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1122 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1125 Note that if the RTC uses I2C, then the I2C interface
1126 must also be configured. See I2C Support, below.
1129 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1131 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1132 chip-ngpio pairs that tell the PCA953X driver the number of
1133 pins supported by a particular chip.
1135 Note that if the GPIO device uses I2C, then the I2C interface
1136 must also be configured. See I2C Support, below.
1138 - Timestamp Support:
1140 When CONFIG_TIMESTAMP is selected, the timestamp
1141 (date and time) of an image is printed by image
1142 commands like bootm or iminfo. This option is
1143 automatically enabled when you select CONFIG_CMD_DATE .
1145 - Partition Labels (disklabels) Supported:
1146 Zero or more of the following:
1147 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1148 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1149 Intel architecture, USB sticks, etc.
1150 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1151 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1152 bootloader. Note 2TB partition limit; see
1154 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1156 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1157 CONFIG_CMD_SCSI) you must configure support for at
1158 least one non-MTD partition type as well.
1161 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1162 board configurations files but used nowhere!
1164 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1165 be performed by calling the function
1166 ide_set_reset(int reset)
1167 which has to be defined in a board specific file
1172 Set this to enable ATAPI support.
1177 Set this to enable support for disks larger than 137GB
1178 Also look at CONFIG_SYS_64BIT_LBA.
1179 Whithout these , LBA48 support uses 32bit variables and will 'only'
1180 support disks up to 2.1TB.
1182 CONFIG_SYS_64BIT_LBA:
1183 When enabled, makes the IDE subsystem use 64bit sector addresses.
1187 At the moment only there is only support for the
1188 SYM53C8XX SCSI controller; define
1189 CONFIG_SCSI_SYM53C8XX to enable it.
1191 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1192 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1193 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1194 maximum numbers of LUNs, SCSI ID's and target
1196 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1198 The environment variable 'scsidevs' is set to the number of
1199 SCSI devices found during the last scan.
1201 - NETWORK Support (PCI):
1203 Support for Intel 8254x/8257x gigabit chips.
1206 Utility code for direct access to the SPI bus on Intel 8257x.
1207 This does not do anything useful unless you set at least one
1208 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1210 CONFIG_E1000_SPI_GENERIC
1211 Allow generic access to the SPI bus on the Intel 8257x, for
1212 example with the "sspi" command.
1215 Management command for E1000 devices. When used on devices
1216 with SPI support you can reprogram the EEPROM from U-Boot.
1218 CONFIG_E1000_FALLBACK_MAC
1219 default MAC for empty EEPROM after production.
1222 Support for Intel 82557/82559/82559ER chips.
1223 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1224 write routine for first time initialisation.
1227 Support for Digital 2114x chips.
1228 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1229 modem chip initialisation (KS8761/QS6611).
1232 Support for National dp83815 chips.
1235 Support for National dp8382[01] gigabit chips.
1237 - NETWORK Support (other):
1239 CONFIG_DRIVER_AT91EMAC
1240 Support for AT91RM9200 EMAC.
1243 Define this to use reduced MII inteface
1245 CONFIG_DRIVER_AT91EMAC_QUIET
1246 If this defined, the driver is quiet.
1247 The driver doen't show link status messages.
1249 CONFIG_CALXEDA_XGMAC
1250 Support for the Calxeda XGMAC device
1253 Support for SMSC's LAN91C96 chips.
1255 CONFIG_LAN91C96_BASE
1256 Define this to hold the physical address
1257 of the LAN91C96's I/O space
1259 CONFIG_LAN91C96_USE_32_BIT
1260 Define this to enable 32 bit addressing
1263 Support for SMSC's LAN91C111 chip
1265 CONFIG_SMC91111_BASE
1266 Define this to hold the physical address
1267 of the device (I/O space)
1269 CONFIG_SMC_USE_32_BIT
1270 Define this if data bus is 32 bits
1272 CONFIG_SMC_USE_IOFUNCS
1273 Define this to use i/o functions instead of macros
1274 (some hardware wont work with macros)
1276 CONFIG_DRIVER_TI_EMAC
1277 Support for davinci emac
1279 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1280 Define this if you have more then 3 PHYs.
1283 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1285 CONFIG_FTGMAC100_EGIGA
1286 Define this to use GE link update with gigabit PHY.
1287 Define this if FTGMAC100 is connected to gigabit PHY.
1288 If your system has 10/100 PHY only, it might not occur
1289 wrong behavior. Because PHY usually return timeout or
1290 useless data when polling gigabit status and gigabit
1291 control registers. This behavior won't affect the
1292 correctnessof 10/100 link speed update.
1295 Support for SMSC's LAN911x and LAN921x chips
1298 Define this to hold the physical address
1299 of the device (I/O space)
1301 CONFIG_SMC911X_32_BIT
1302 Define this if data bus is 32 bits
1304 CONFIG_SMC911X_16_BIT
1305 Define this if data bus is 16 bits. If your processor
1306 automatically converts one 32 bit word to two 16 bit
1307 words you may also try CONFIG_SMC911X_32_BIT.
1310 Support for Renesas on-chip Ethernet controller
1312 CONFIG_SH_ETHER_USE_PORT
1313 Define the number of ports to be used
1315 CONFIG_SH_ETHER_PHY_ADDR
1316 Define the ETH PHY's address
1318 CONFIG_SH_ETHER_CACHE_WRITEBACK
1319 If this option is set, the driver enables cache flush.
1323 Support TPM devices.
1326 Support for i2c bus TPM devices. Only one device
1327 per system is supported at this time.
1329 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1330 Define the the i2c bus number for the TPM device
1332 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1333 Define the TPM's address on the i2c bus
1335 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1336 Define the burst count bytes upper limit
1338 CONFIG_TPM_ATMEL_TWI
1339 Support for Atmel TWI TPM device. Requires I2C support.
1342 Support for generic parallel port TPM devices. Only one device
1343 per system is supported at this time.
1345 CONFIG_TPM_TIS_BASE_ADDRESS
1346 Base address where the generic TPM device is mapped
1347 to. Contemporary x86 systems usually map it at
1351 Add tpm monitor functions.
1352 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1353 provides monitor access to authorized functions.
1356 Define this to enable the TPM support library which provides
1357 functional interfaces to some TPM commands.
1358 Requires support for a TPM device.
1360 CONFIG_TPM_AUTH_SESSIONS
1361 Define this to enable authorized functions in the TPM library.
1362 Requires CONFIG_TPM and CONFIG_SHA1.
1365 At the moment only the UHCI host controller is
1366 supported (PIP405, MIP405, MPC5200); define
1367 CONFIG_USB_UHCI to enable it.
1368 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1369 and define CONFIG_USB_STORAGE to enable the USB
1372 Supported are USB Keyboards and USB Floppy drives
1374 MPC5200 USB requires additional defines:
1376 for 528 MHz Clock: 0x0001bbbb
1380 for differential drivers: 0x00001000
1381 for single ended drivers: 0x00005000
1382 for differential drivers on PSC3: 0x00000100
1383 for single ended drivers on PSC3: 0x00004100
1384 CONFIG_SYS_USB_EVENT_POLL
1385 May be defined to allow interrupt polling
1386 instead of using asynchronous interrupts
1388 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1389 txfilltuning field in the EHCI controller on reset.
1391 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1392 interval for usb hub power-on delay.(minimum 100msec)
1395 Define the below if you wish to use the USB console.
1396 Once firmware is rebuilt from a serial console issue the
1397 command "setenv stdin usbtty; setenv stdout usbtty" and
1398 attach your USB cable. The Unix command "dmesg" should print
1399 it has found a new device. The environment variable usbtty
1400 can be set to gserial or cdc_acm to enable your device to
1401 appear to a USB host as a Linux gserial device or a
1402 Common Device Class Abstract Control Model serial device.
1403 If you select usbtty = gserial you should be able to enumerate
1405 # modprobe usbserial vendor=0xVendorID product=0xProductID
1406 else if using cdc_acm, simply setting the environment
1407 variable usbtty to be cdc_acm should suffice. The following
1408 might be defined in YourBoardName.h
1411 Define this to build a UDC device
1414 Define this to have a tty type of device available to
1415 talk to the UDC device
1418 Define this to enable the high speed support for usb
1419 device and usbtty. If this feature is enabled, a routine
1420 int is_usbd_high_speed(void)
1421 also needs to be defined by the driver to dynamically poll
1422 whether the enumeration has succeded at high speed or full
1425 CONFIG_SYS_CONSOLE_IS_IN_ENV
1426 Define this if you want stdin, stdout &/or stderr to
1430 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1431 Derive USB clock from external clock "blah"
1432 - CONFIG_SYS_USB_EXTC_CLK 0x02
1434 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1435 Derive USB clock from brgclk
1436 - CONFIG_SYS_USB_BRG_CLK 0x04
1438 If you have a USB-IF assigned VendorID then you may wish to
1439 define your own vendor specific values either in BoardName.h
1440 or directly in usbd_vendor_info.h. If you don't define
1441 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1442 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1443 should pretend to be a Linux device to it's target host.
1445 CONFIG_USBD_MANUFACTURER
1446 Define this string as the name of your company for
1447 - CONFIG_USBD_MANUFACTURER "my company"
1449 CONFIG_USBD_PRODUCT_NAME
1450 Define this string as the name of your product
1451 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1453 CONFIG_USBD_VENDORID
1454 Define this as your assigned Vendor ID from the USB
1455 Implementors Forum. This *must* be a genuine Vendor ID
1456 to avoid polluting the USB namespace.
1457 - CONFIG_USBD_VENDORID 0xFFFF
1459 CONFIG_USBD_PRODUCTID
1460 Define this as the unique Product ID
1462 - CONFIG_USBD_PRODUCTID 0xFFFF
1464 Some USB device drivers may need to check USB cable attachment.
1465 In this case you can enable following config in BoardName.h:
1466 CONFIG_USB_CABLE_CHECK
1467 This enables function definition:
1468 - usb_cable_connected() in include/usb.h
1469 Implementation of this function is board-specific.
1471 - ULPI Layer Support:
1472 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1473 the generic ULPI layer. The generic layer accesses the ULPI PHY
1474 via the platform viewport, so you need both the genric layer and
1475 the viewport enabled. Currently only Chipidea/ARC based
1476 viewport is supported.
1477 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1478 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1479 If your ULPI phy needs a different reference clock than the
1480 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1481 the appropriate value in Hz.
1484 The MMC controller on the Intel PXA is supported. To
1485 enable this define CONFIG_MMC. The MMC can be
1486 accessed from the boot prompt by mapping the device
1487 to physical memory similar to flash. Command line is
1488 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1489 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1492 Support for Renesas on-chip MMCIF controller
1494 CONFIG_SH_MMCIF_ADDR
1495 Define the base address of MMCIF registers
1498 Define the clock frequency for MMCIF
1500 - USB Device Firmware Update (DFU) class support:
1502 This enables the USB portion of the DFU USB class
1505 This enables the command "dfu" which is used to have
1506 U-Boot create a DFU class device via USB. This command
1507 requires that the "dfu_alt_info" environment variable be
1508 set and define the alt settings to expose to the host.
1511 This enables support for exposing (e)MMC devices via DFU.
1514 This enables support for exposing NAND devices via DFU.
1517 This enables support for exposing RAM via DFU.
1518 Note: DFU spec refer to non-volatile memory usage, but
1519 allow usages beyond the scope of spec - here RAM usage,
1520 one that would help mostly the developer.
1522 CONFIG_SYS_DFU_DATA_BUF_SIZE
1523 Dfu transfer uses a buffer before writing data to the
1524 raw storage device. Make the size (in bytes) of this buffer
1525 configurable. The size of this buffer is also configurable
1526 through the "dfu_bufsiz" environment variable.
1528 CONFIG_SYS_DFU_MAX_FILE_SIZE
1529 When updating files rather than the raw storage device,
1530 we use a static buffer to copy the file into and then write
1531 the buffer once we've been given the whole file. Define
1532 this to the maximum filesize (in bytes) for the buffer.
1533 Default is 4 MiB if undefined.
1535 DFU_DEFAULT_POLL_TIMEOUT
1536 Poll timeout [ms], is the timeout a device can send to the
1537 host. The host must wait for this timeout before sending
1538 a subsequent DFU_GET_STATUS request to the device.
1540 DFU_MANIFEST_POLL_TIMEOUT
1541 Poll timeout [ms], which the device sends to the host when
1542 entering dfuMANIFEST state. Host waits this timeout, before
1543 sending again an USB request to the device.
1545 - Journaling Flash filesystem support:
1546 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1547 CONFIG_JFFS2_NAND_DEV
1548 Define these for a default partition on a NAND device
1550 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1551 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1552 Define these for a default partition on a NOR device
1554 CONFIG_SYS_JFFS_CUSTOM_PART
1555 Define this to create an own partition. You have to provide a
1556 function struct part_info* jffs2_part_info(int part_num)
1558 If you define only one JFFS2 partition you may also want to
1559 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1560 to disable the command chpart. This is the default when you
1561 have not defined a custom partition
1563 - FAT(File Allocation Table) filesystem write function support:
1566 Define this to enable support for saving memory data as a
1567 file in FAT formatted partition.
1569 This will also enable the command "fatwrite" enabling the
1570 user to write files to FAT.
1572 CBFS (Coreboot Filesystem) support
1575 Define this to enable support for reading from a Coreboot
1576 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1582 Define this to enable standard (PC-Style) keyboard
1586 Standard PC keyboard driver with US (is default) and
1587 GERMAN key layout (switch via environment 'keymap=de') support.
1588 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1589 for cfb_console. Supports cursor blinking.
1592 Enables a Chrome OS keyboard using the CROS_EC interface.
1593 This uses CROS_EC to communicate with a second microcontroller
1594 which provides key scans on request.
1599 Define this to enable video support (for output to
1602 CONFIG_VIDEO_CT69000
1604 Enable Chips & Technologies 69000 Video chip
1606 CONFIG_VIDEO_SMI_LYNXEM
1607 Enable Silicon Motion SMI 712/710/810 Video chip. The
1608 video output is selected via environment 'videoout'
1609 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1612 For the CT69000 and SMI_LYNXEM drivers, videomode is
1613 selected via environment 'videomode'. Two different ways
1615 - "videomode=num" 'num' is a standard LiLo mode numbers.
1616 Following standard modes are supported (* is default):
1618 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1619 -------------+---------------------------------------------
1620 8 bits | 0x301* 0x303 0x305 0x161 0x307
1621 15 bits | 0x310 0x313 0x316 0x162 0x319
1622 16 bits | 0x311 0x314 0x317 0x163 0x31A
1623 24 bits | 0x312 0x315 0x318 ? 0x31B
1624 -------------+---------------------------------------------
1625 (i.e. setenv videomode 317; saveenv; reset;)
1627 - "videomode=bootargs" all the video parameters are parsed
1628 from the bootargs. (See drivers/video/videomodes.c)
1631 CONFIG_VIDEO_SED13806
1632 Enable Epson SED13806 driver. This driver supports 8bpp
1633 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1634 or CONFIG_VIDEO_SED13806_16BPP
1637 Enable the Freescale DIU video driver. Reference boards for
1638 SOCs that have a DIU should define this macro to enable DIU
1639 support, and should also define these other macros:
1645 CONFIG_VIDEO_SW_CURSOR
1646 CONFIG_VGA_AS_SINGLE_DEVICE
1648 CONFIG_VIDEO_BMP_LOGO
1650 The DIU driver will look for the 'video-mode' environment
1651 variable, and if defined, enable the DIU as a console during
1652 boot. See the documentation file README.video for a
1653 description of this variable.
1657 Enable the VGA video / BIOS for x86. The alternative if you
1658 are using coreboot is to use the coreboot frame buffer
1665 Define this to enable a custom keyboard support.
1666 This simply calls drv_keyboard_init() which must be
1667 defined in your board-specific files.
1668 The only board using this so far is RBC823.
1670 - LCD Support: CONFIG_LCD
1672 Define this to enable LCD support (for output to LCD
1673 display); also select one of the supported displays
1674 by defining one of these:
1678 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1680 CONFIG_NEC_NL6448AC33:
1682 NEC NL6448AC33-18. Active, color, single scan.
1684 CONFIG_NEC_NL6448BC20
1686 NEC NL6448BC20-08. 6.5", 640x480.
1687 Active, color, single scan.
1689 CONFIG_NEC_NL6448BC33_54
1691 NEC NL6448BC33-54. 10.4", 640x480.
1692 Active, color, single scan.
1696 Sharp 320x240. Active, color, single scan.
1697 It isn't 16x9, and I am not sure what it is.
1699 CONFIG_SHARP_LQ64D341
1701 Sharp LQ64D341 display, 640x480.
1702 Active, color, single scan.
1706 HLD1045 display, 640x480.
1707 Active, color, single scan.
1711 Optrex CBL50840-2 NF-FW 99 22 M5
1713 Hitachi LMG6912RPFC-00T
1717 320x240. Black & white.
1719 Normally display is black on white background; define
1720 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1722 CONFIG_LCD_ALIGNMENT
1724 Normally the LCD is page-aligned (tyically 4KB). If this is
1725 defined then the LCD will be aligned to this value instead.
1726 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1727 here, since it is cheaper to change data cache settings on
1728 a per-section basis.
1730 CONFIG_CONSOLE_SCROLL_LINES
1732 When the console need to be scrolled, this is the number of
1733 lines to scroll by. It defaults to 1. Increasing this makes
1734 the console jump but can help speed up operation when scrolling
1739 Support drawing of RLE8-compressed bitmaps on the LCD.
1743 Enables an 'i2c edid' command which can read EDID
1744 information over I2C from an attached LCD display.
1746 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1748 If this option is set, the environment is checked for
1749 a variable "splashimage". If found, the usual display
1750 of logo, copyright and system information on the LCD
1751 is suppressed and the BMP image at the address
1752 specified in "splashimage" is loaded instead. The
1753 console is redirected to the "nulldev", too. This
1754 allows for a "silent" boot where a splash screen is
1755 loaded very quickly after power-on.
1757 CONFIG_SPLASHIMAGE_GUARD
1759 If this option is set, then U-Boot will prevent the environment
1760 variable "splashimage" from being set to a problematic address
1761 (see README.displaying-bmps).
1762 This option is useful for targets where, due to alignment
1763 restrictions, an improperly aligned BMP image will cause a data
1764 abort. If you think you will not have problems with unaligned
1765 accesses (for example because your toolchain prevents them)
1766 there is no need to set this option.
1768 CONFIG_SPLASH_SCREEN_ALIGN
1770 If this option is set the splash image can be freely positioned
1771 on the screen. Environment variable "splashpos" specifies the
1772 position as "x,y". If a positive number is given it is used as
1773 number of pixel from left/top. If a negative number is given it
1774 is used as number of pixel from right/bottom. You can also
1775 specify 'm' for centering the image.
1778 setenv splashpos m,m
1779 => image at center of screen
1781 setenv splashpos 30,20
1782 => image at x = 30 and y = 20
1784 setenv splashpos -10,m
1785 => vertically centered image
1786 at x = dspWidth - bmpWidth - 9
1788 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1790 If this option is set, additionally to standard BMP
1791 images, gzipped BMP images can be displayed via the
1792 splashscreen support or the bmp command.
1794 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1796 If this option is set, 8-bit RLE compressed BMP images
1797 can be displayed via the splashscreen support or the
1800 - Do compresssing for memory range:
1803 If this option is set, it would use zlib deflate method
1804 to compress the specified memory at its best effort.
1806 - Compression support:
1809 Enabled by default to support gzip compressed images.
1813 If this option is set, support for bzip2 compressed
1814 images is included. If not, only uncompressed and gzip
1815 compressed images are supported.
1817 NOTE: the bzip2 algorithm requires a lot of RAM, so
1818 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1823 If this option is set, support for lzma compressed
1826 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1827 requires an amount of dynamic memory that is given by the
1830 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1832 Where lc and lp stand for, respectively, Literal context bits
1833 and Literal pos bits.
1835 This value is upper-bounded by 14MB in the worst case. Anyway,
1836 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1837 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1838 a very small buffer.
1840 Use the lzmainfo tool to determinate the lc and lp values and
1841 then calculate the amount of needed dynamic memory (ensuring
1842 the appropriate CONFIG_SYS_MALLOC_LEN value).
1846 If this option is set, support for LZO compressed images
1852 The address of PHY on MII bus.
1854 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1856 The clock frequency of the MII bus
1860 If this option is set, support for speed/duplex
1861 detection of gigabit PHY is included.
1863 CONFIG_PHY_RESET_DELAY
1865 Some PHY like Intel LXT971A need extra delay after
1866 reset before any MII register access is possible.
1867 For such PHY, set this option to the usec delay
1868 required. (minimum 300usec for LXT971A)
1870 CONFIG_PHY_CMD_DELAY (ppc4xx)
1872 Some PHY like Intel LXT971A need extra delay after
1873 command issued before MII status register can be read
1883 Define a default value for Ethernet address to use
1884 for the respective Ethernet interface, in case this
1885 is not determined automatically.
1890 Define a default value for the IP address to use for
1891 the default Ethernet interface, in case this is not
1892 determined through e.g. bootp.
1893 (Environment variable "ipaddr")
1895 - Server IP address:
1898 Defines a default value for the IP address of a TFTP
1899 server to contact when using the "tftboot" command.
1900 (Environment variable "serverip")
1902 CONFIG_KEEP_SERVERADDR
1904 Keeps the server's MAC address, in the env 'serveraddr'
1905 for passing to bootargs (like Linux's netconsole option)
1907 - Gateway IP address:
1910 Defines a default value for the IP address of the
1911 default router where packets to other networks are
1913 (Environment variable "gatewayip")
1918 Defines a default value for the subnet mask (or
1919 routing prefix) which is used to determine if an IP
1920 address belongs to the local subnet or needs to be
1921 forwarded through a router.
1922 (Environment variable "netmask")
1924 - Multicast TFTP Mode:
1927 Defines whether you want to support multicast TFTP as per
1928 rfc-2090; for example to work with atftp. Lets lots of targets
1929 tftp down the same boot image concurrently. Note: the Ethernet
1930 driver in use must provide a function: mcast() to join/leave a
1933 - BOOTP Recovery Mode:
1934 CONFIG_BOOTP_RANDOM_DELAY
1936 If you have many targets in a network that try to
1937 boot using BOOTP, you may want to avoid that all
1938 systems send out BOOTP requests at precisely the same
1939 moment (which would happen for instance at recovery
1940 from a power failure, when all systems will try to
1941 boot, thus flooding the BOOTP server. Defining
1942 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1943 inserted before sending out BOOTP requests. The
1944 following delays are inserted then:
1946 1st BOOTP request: delay 0 ... 1 sec
1947 2nd BOOTP request: delay 0 ... 2 sec
1948 3rd BOOTP request: delay 0 ... 4 sec
1950 BOOTP requests: delay 0 ... 8 sec
1952 - DHCP Advanced Options:
1953 You can fine tune the DHCP functionality by defining
1954 CONFIG_BOOTP_* symbols:
1956 CONFIG_BOOTP_SUBNETMASK
1957 CONFIG_BOOTP_GATEWAY
1958 CONFIG_BOOTP_HOSTNAME
1959 CONFIG_BOOTP_NISDOMAIN
1960 CONFIG_BOOTP_BOOTPATH
1961 CONFIG_BOOTP_BOOTFILESIZE
1964 CONFIG_BOOTP_SEND_HOSTNAME
1965 CONFIG_BOOTP_NTPSERVER
1966 CONFIG_BOOTP_TIMEOFFSET
1967 CONFIG_BOOTP_VENDOREX
1968 CONFIG_BOOTP_MAY_FAIL
1970 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1971 environment variable, not the BOOTP server.
1973 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1974 after the configured retry count, the call will fail
1975 instead of starting over. This can be used to fail over
1976 to Link-local IP address configuration if the DHCP server
1979 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1980 serverip from a DHCP server, it is possible that more
1981 than one DNS serverip is offered to the client.
1982 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1983 serverip will be stored in the additional environment
1984 variable "dnsip2". The first DNS serverip is always
1985 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1988 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1989 to do a dynamic update of a DNS server. To do this, they
1990 need the hostname of the DHCP requester.
1991 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1992 of the "hostname" environment variable is passed as
1993 option 12 to the DHCP server.
1995 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1997 A 32bit value in microseconds for a delay between
1998 receiving a "DHCP Offer" and sending the "DHCP Request".
1999 This fixes a problem with certain DHCP servers that don't
2000 respond 100% of the time to a "DHCP request". E.g. On an
2001 AT91RM9200 processor running at 180MHz, this delay needed
2002 to be *at least* 15,000 usec before a Windows Server 2003
2003 DHCP server would reply 100% of the time. I recommend at
2004 least 50,000 usec to be safe. The alternative is to hope
2005 that one of the retries will be successful but note that
2006 the DHCP timeout and retry process takes a longer than
2009 - Link-local IP address negotiation:
2010 Negotiate with other link-local clients on the local network
2011 for an address that doesn't require explicit configuration.
2012 This is especially useful if a DHCP server cannot be guaranteed
2013 to exist in all environments that the device must operate.
2015 See doc/README.link-local for more information.
2018 CONFIG_CDP_DEVICE_ID
2020 The device id used in CDP trigger frames.
2022 CONFIG_CDP_DEVICE_ID_PREFIX
2024 A two character string which is prefixed to the MAC address
2029 A printf format string which contains the ascii name of
2030 the port. Normally is set to "eth%d" which sets
2031 eth0 for the first Ethernet, eth1 for the second etc.
2033 CONFIG_CDP_CAPABILITIES
2035 A 32bit integer which indicates the device capabilities;
2036 0x00000010 for a normal host which does not forwards.
2040 An ascii string containing the version of the software.
2044 An ascii string containing the name of the platform.
2048 A 32bit integer sent on the trigger.
2050 CONFIG_CDP_POWER_CONSUMPTION
2052 A 16bit integer containing the power consumption of the
2053 device in .1 of milliwatts.
2055 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2057 A byte containing the id of the VLAN.
2059 - Status LED: CONFIG_STATUS_LED
2061 Several configurations allow to display the current
2062 status using a LED. For instance, the LED will blink
2063 fast while running U-Boot code, stop blinking as
2064 soon as a reply to a BOOTP request was received, and
2065 start blinking slow once the Linux kernel is running
2066 (supported by a status LED driver in the Linux
2067 kernel). Defining CONFIG_STATUS_LED enables this
2073 The status LED can be connected to a GPIO pin.
2074 In such cases, the gpio_led driver can be used as a
2075 status LED backend implementation. Define CONFIG_GPIO_LED
2076 to include the gpio_led driver in the U-Boot binary.
2078 CONFIG_GPIO_LED_INVERTED_TABLE
2079 Some GPIO connected LEDs may have inverted polarity in which
2080 case the GPIO high value corresponds to LED off state and
2081 GPIO low value corresponds to LED on state.
2082 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2083 with a list of GPIO LEDs that have inverted polarity.
2085 - CAN Support: CONFIG_CAN_DRIVER
2087 Defining CONFIG_CAN_DRIVER enables CAN driver support
2088 on those systems that support this (optional)
2089 feature, like the TQM8xxL modules.
2091 - I2C Support: CONFIG_SYS_I2C
2093 This enable the NEW i2c subsystem, and will allow you to use
2094 i2c commands at the u-boot command line (as long as you set
2095 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2096 based realtime clock chips or other i2c devices. See
2097 common/cmd_i2c.c for a description of the command line
2100 ported i2c driver to the new framework:
2101 - drivers/i2c/soft_i2c.c:
2102 - activate first bus with CONFIG_SYS_I2C_SOFT define
2103 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2104 for defining speed and slave address
2105 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2106 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2107 for defining speed and slave address
2108 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2109 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2110 for defining speed and slave address
2111 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2112 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2113 for defining speed and slave address
2115 - drivers/i2c/fsl_i2c.c:
2116 - activate i2c driver with CONFIG_SYS_I2C_FSL
2117 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2118 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2119 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2121 - If your board supports a second fsl i2c bus, define
2122 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2123 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2124 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2127 - drivers/i2c/tegra_i2c.c:
2128 - activate this driver with CONFIG_SYS_I2C_TEGRA
2129 - This driver adds 4 i2c buses with a fix speed from
2130 100000 and the slave addr 0!
2132 - drivers/i2c/ppc4xx_i2c.c
2133 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2134 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2135 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2137 - drivers/i2c/i2c_mxc.c
2138 - activate this driver with CONFIG_SYS_I2C_MXC
2139 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2140 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2141 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2142 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2143 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2144 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2145 If thoses defines are not set, default value is 100000
2146 for speed, and 0 for slave.
2148 - drivers/i2c/rcar_i2c.c:
2149 - activate this driver with CONFIG_SYS_I2C_RCAR
2150 - This driver adds 4 i2c buses
2152 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2153 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2154 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2155 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2156 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2157 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2158 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2159 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2160 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2162 - drivers/i2c/sh_i2c.c:
2163 - activate this driver with CONFIG_SYS_I2C_SH
2164 - This driver adds from 2 to 5 i2c buses
2166 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2167 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2168 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2169 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2170 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2171 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2172 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2173 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2174 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2175 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2176 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2177 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2178 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2180 - drivers/i2c/omap24xx_i2c.c
2181 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2182 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2183 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2184 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2185 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2186 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2187 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2188 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2189 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2190 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2191 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2193 - drivers/i2c/zynq_i2c.c
2194 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2195 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2196 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2198 - drivers/i2c/s3c24x0_i2c.c:
2199 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2200 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2201 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2202 with a fix speed from 100000 and the slave addr 0!
2206 CONFIG_SYS_NUM_I2C_BUSES
2207 Hold the number of i2c busses you want to use. If you
2208 don't use/have i2c muxes on your i2c bus, this
2209 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2212 CONFIG_SYS_I2C_DIRECT_BUS
2213 define this, if you don't use i2c muxes on your hardware.
2214 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2217 CONFIG_SYS_I2C_MAX_HOPS
2218 define how many muxes are maximal consecutively connected
2219 on one i2c bus. If you not use i2c muxes, omit this
2222 CONFIG_SYS_I2C_BUSES
2223 hold a list of busses you want to use, only used if
2224 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2225 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2226 CONFIG_SYS_NUM_I2C_BUSES = 9:
2228 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2229 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2230 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2231 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2232 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2233 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2234 {1, {I2C_NULL_HOP}}, \
2235 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2236 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2240 bus 0 on adapter 0 without a mux
2241 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2242 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2243 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2244 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2245 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2246 bus 6 on adapter 1 without a mux
2247 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2248 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2250 If you do not have i2c muxes on your board, omit this define.
2252 - Legacy I2C Support: CONFIG_HARD_I2C
2254 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2255 provides the following compelling advantages:
2257 - more than one i2c adapter is usable
2258 - approved multibus support
2259 - better i2c mux support
2261 ** Please consider updating your I2C driver now. **
2263 These enable legacy I2C serial bus commands. Defining
2264 CONFIG_HARD_I2C will include the appropriate I2C driver
2265 for the selected CPU.
2267 This will allow you to use i2c commands at the u-boot
2268 command line (as long as you set CONFIG_CMD_I2C in
2269 CONFIG_COMMANDS) and communicate with i2c based realtime
2270 clock chips. See common/cmd_i2c.c for a description of the
2271 command line interface.
2273 CONFIG_HARD_I2C selects a hardware I2C controller.
2275 There are several other quantities that must also be
2276 defined when you define CONFIG_HARD_I2C.
2278 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2279 to be the frequency (in Hz) at which you wish your i2c bus
2280 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2281 the CPU's i2c node address).
2283 Now, the u-boot i2c code for the mpc8xx
2284 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2285 and so its address should therefore be cleared to 0 (See,
2286 eg, MPC823e User's Manual p.16-473). So, set
2287 CONFIG_SYS_I2C_SLAVE to 0.
2289 CONFIG_SYS_I2C_INIT_MPC5XXX
2291 When a board is reset during an i2c bus transfer
2292 chips might think that the current transfer is still
2293 in progress. Reset the slave devices by sending start
2294 commands until the slave device responds.
2296 That's all that's required for CONFIG_HARD_I2C.
2298 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2299 then the following macros need to be defined (examples are
2300 from include/configs/lwmon.h):
2304 (Optional). Any commands necessary to enable the I2C
2305 controller or configure ports.
2307 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2311 (Only for MPC8260 CPU). The I/O port to use (the code
2312 assumes both bits are on the same port). Valid values
2313 are 0..3 for ports A..D.
2317 The code necessary to make the I2C data line active
2318 (driven). If the data line is open collector, this
2321 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2325 The code necessary to make the I2C data line tri-stated
2326 (inactive). If the data line is open collector, this
2329 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2333 Code that returns true if the I2C data line is high,
2336 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2340 If <bit> is true, sets the I2C data line high. If it
2341 is false, it clears it (low).
2343 eg: #define I2C_SDA(bit) \
2344 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2345 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2349 If <bit> is true, sets the I2C clock line high. If it
2350 is false, it clears it (low).
2352 eg: #define I2C_SCL(bit) \
2353 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2354 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2358 This delay is invoked four times per clock cycle so this
2359 controls the rate of data transfer. The data rate thus
2360 is 1 / (I2C_DELAY * 4). Often defined to be something
2363 #define I2C_DELAY udelay(2)
2365 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2367 If your arch supports the generic GPIO framework (asm/gpio.h),
2368 then you may alternatively define the two GPIOs that are to be
2369 used as SCL / SDA. Any of the previous I2C_xxx macros will
2370 have GPIO-based defaults assigned to them as appropriate.
2372 You should define these to the GPIO value as given directly to
2373 the generic GPIO functions.
2375 CONFIG_SYS_I2C_INIT_BOARD
2377 When a board is reset during an i2c bus transfer
2378 chips might think that the current transfer is still
2379 in progress. On some boards it is possible to access
2380 the i2c SCLK line directly, either by using the
2381 processor pin as a GPIO or by having a second pin
2382 connected to the bus. If this option is defined a
2383 custom i2c_init_board() routine in boards/xxx/board.c
2384 is run early in the boot sequence.
2386 CONFIG_SYS_I2C_BOARD_LATE_INIT
2388 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2389 defined a custom i2c_board_late_init() routine in
2390 boards/xxx/board.c is run AFTER the operations in i2c_init()
2391 is completed. This callpoint can be used to unreset i2c bus
2392 using CPU i2c controller register accesses for CPUs whose i2c
2393 controller provide such a method. It is called at the end of
2394 i2c_init() to allow i2c_init operations to setup the i2c bus
2395 controller on the CPU (e.g. setting bus speed & slave address).
2397 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2399 This option enables configuration of bi_iic_fast[] flags
2400 in u-boot bd_info structure based on u-boot environment
2401 variable "i2cfast". (see also i2cfast)
2403 CONFIG_I2C_MULTI_BUS
2405 This option allows the use of multiple I2C buses, each of which
2406 must have a controller. At any point in time, only one bus is
2407 active. To switch to a different bus, use the 'i2c dev' command.
2408 Note that bus numbering is zero-based.
2410 CONFIG_SYS_I2C_NOPROBES
2412 This option specifies a list of I2C devices that will be skipped
2413 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2414 is set, specify a list of bus-device pairs. Otherwise, specify
2415 a 1D array of device addresses
2418 #undef CONFIG_I2C_MULTI_BUS
2419 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2421 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2423 #define CONFIG_I2C_MULTI_BUS
2424 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2426 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2428 CONFIG_SYS_SPD_BUS_NUM
2430 If defined, then this indicates the I2C bus number for DDR SPD.
2431 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2433 CONFIG_SYS_RTC_BUS_NUM
2435 If defined, then this indicates the I2C bus number for the RTC.
2436 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2438 CONFIG_SYS_DTT_BUS_NUM
2440 If defined, then this indicates the I2C bus number for the DTT.
2441 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2443 CONFIG_SYS_I2C_DTT_ADDR:
2445 If defined, specifies the I2C address of the DTT device.
2446 If not defined, then U-Boot uses predefined value for
2447 specified DTT device.
2449 CONFIG_SOFT_I2C_READ_REPEATED_START
2451 defining this will force the i2c_read() function in
2452 the soft_i2c driver to perform an I2C repeated start
2453 between writing the address pointer and reading the
2454 data. If this define is omitted the default behaviour
2455 of doing a stop-start sequence will be used. Most I2C
2456 devices can use either method, but some require one or
2459 - SPI Support: CONFIG_SPI
2461 Enables SPI driver (so far only tested with
2462 SPI EEPROM, also an instance works with Crystal A/D and
2463 D/As on the SACSng board)
2467 Enables the driver for SPI controller on SuperH. Currently
2468 only SH7757 is supported.
2472 Enables extended (16-bit) SPI EEPROM addressing.
2473 (symmetrical to CONFIG_I2C_X)
2477 Enables a software (bit-bang) SPI driver rather than
2478 using hardware support. This is a general purpose
2479 driver that only requires three general I/O port pins
2480 (two outputs, one input) to function. If this is
2481 defined, the board configuration must define several
2482 SPI configuration items (port pins to use, etc). For
2483 an example, see include/configs/sacsng.h.
2487 Enables a hardware SPI driver for general-purpose reads
2488 and writes. As with CONFIG_SOFT_SPI, the board configuration
2489 must define a list of chip-select function pointers.
2490 Currently supported on some MPC8xxx processors. For an
2491 example, see include/configs/mpc8349emds.h.
2495 Enables the driver for the SPI controllers on i.MX and MXC
2496 SoCs. Currently i.MX31/35/51 are supported.
2498 - FPGA Support: CONFIG_FPGA
2500 Enables FPGA subsystem.
2502 CONFIG_FPGA_<vendor>
2504 Enables support for specific chip vendors.
2507 CONFIG_FPGA_<family>
2509 Enables support for FPGA family.
2510 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2514 Specify the number of FPGA devices to support.
2516 CONFIG_SYS_FPGA_PROG_FEEDBACK
2518 Enable printing of hash marks during FPGA configuration.
2520 CONFIG_SYS_FPGA_CHECK_BUSY
2522 Enable checks on FPGA configuration interface busy
2523 status by the configuration function. This option
2524 will require a board or device specific function to
2529 If defined, a function that provides delays in the FPGA
2530 configuration driver.
2532 CONFIG_SYS_FPGA_CHECK_CTRLC
2533 Allow Control-C to interrupt FPGA configuration
2535 CONFIG_SYS_FPGA_CHECK_ERROR
2537 Check for configuration errors during FPGA bitfile
2538 loading. For example, abort during Virtex II
2539 configuration if the INIT_B line goes low (which
2540 indicated a CRC error).
2542 CONFIG_SYS_FPGA_WAIT_INIT
2544 Maximum time to wait for the INIT_B line to deassert
2545 after PROB_B has been deasserted during a Virtex II
2546 FPGA configuration sequence. The default time is 500
2549 CONFIG_SYS_FPGA_WAIT_BUSY
2551 Maximum time to wait for BUSY to deassert during
2552 Virtex II FPGA configuration. The default is 5 ms.
2554 CONFIG_SYS_FPGA_WAIT_CONFIG
2556 Time to wait after FPGA configuration. The default is
2559 - Configuration Management:
2562 If defined, this string will be added to the U-Boot
2563 version information (U_BOOT_VERSION)
2565 - Vendor Parameter Protection:
2567 U-Boot considers the values of the environment
2568 variables "serial#" (Board Serial Number) and
2569 "ethaddr" (Ethernet Address) to be parameters that
2570 are set once by the board vendor / manufacturer, and
2571 protects these variables from casual modification by
2572 the user. Once set, these variables are read-only,
2573 and write or delete attempts are rejected. You can
2574 change this behaviour:
2576 If CONFIG_ENV_OVERWRITE is #defined in your config
2577 file, the write protection for vendor parameters is
2578 completely disabled. Anybody can change or delete
2581 Alternatively, if you #define _both_ CONFIG_ETHADDR
2582 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2583 Ethernet address is installed in the environment,
2584 which can be changed exactly ONCE by the user. [The
2585 serial# is unaffected by this, i. e. it remains
2588 The same can be accomplished in a more flexible way
2589 for any variable by configuring the type of access
2590 to allow for those variables in the ".flags" variable
2591 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2596 Define this variable to enable the reservation of
2597 "protected RAM", i. e. RAM which is not overwritten
2598 by U-Boot. Define CONFIG_PRAM to hold the number of
2599 kB you want to reserve for pRAM. You can overwrite
2600 this default value by defining an environment
2601 variable "pram" to the number of kB you want to
2602 reserve. Note that the board info structure will
2603 still show the full amount of RAM. If pRAM is
2604 reserved, a new environment variable "mem" will
2605 automatically be defined to hold the amount of
2606 remaining RAM in a form that can be passed as boot
2607 argument to Linux, for instance like that:
2609 setenv bootargs ... mem=\${mem}
2612 This way you can tell Linux not to use this memory,
2613 either, which results in a memory region that will
2614 not be affected by reboots.
2616 *WARNING* If your board configuration uses automatic
2617 detection of the RAM size, you must make sure that
2618 this memory test is non-destructive. So far, the
2619 following board configurations are known to be
2622 IVMS8, IVML24, SPD8xx, TQM8xxL,
2623 HERMES, IP860, RPXlite, LWMON,
2626 - Access to physical memory region (> 4GB)
2627 Some basic support is provided for operations on memory not
2628 normally accessible to U-Boot - e.g. some architectures
2629 support access to more than 4GB of memory on 32-bit
2630 machines using physical address extension or similar.
2631 Define CONFIG_PHYSMEM to access this basic support, which
2632 currently only supports clearing the memory.
2637 Define this variable to stop the system in case of a
2638 fatal error, so that you have to reset it manually.
2639 This is probably NOT a good idea for an embedded
2640 system where you want the system to reboot
2641 automatically as fast as possible, but it may be
2642 useful during development since you can try to debug
2643 the conditions that lead to the situation.
2645 CONFIG_NET_RETRY_COUNT
2647 This variable defines the number of retries for
2648 network operations like ARP, RARP, TFTP, or BOOTP
2649 before giving up the operation. If not defined, a
2650 default value of 5 is used.
2654 Timeout waiting for an ARP reply in milliseconds.
2658 Timeout in milliseconds used in NFS protocol.
2659 If you encounter "ERROR: Cannot umount" in nfs command,
2660 try longer timeout such as
2661 #define CONFIG_NFS_TIMEOUT 10000UL
2663 - Command Interpreter:
2664 CONFIG_AUTO_COMPLETE
2666 Enable auto completion of commands using TAB.
2668 Note that this feature has NOT been implemented yet
2669 for the "hush" shell.
2672 CONFIG_SYS_HUSH_PARSER
2674 Define this variable to enable the "hush" shell (from
2675 Busybox) as command line interpreter, thus enabling
2676 powerful command line syntax like
2677 if...then...else...fi conditionals or `&&' and '||'
2678 constructs ("shell scripts").
2680 If undefined, you get the old, much simpler behaviour
2681 with a somewhat smaller memory footprint.
2684 CONFIG_SYS_PROMPT_HUSH_PS2
2686 This defines the secondary prompt string, which is
2687 printed when the command interpreter needs more input
2688 to complete a command. Usually "> ".
2692 In the current implementation, the local variables
2693 space and global environment variables space are
2694 separated. Local variables are those you define by
2695 simply typing `name=value'. To access a local
2696 variable later on, you have write `$name' or
2697 `${name}'; to execute the contents of a variable
2698 directly type `$name' at the command prompt.
2700 Global environment variables are those you use
2701 setenv/printenv to work with. To run a command stored
2702 in such a variable, you need to use the run command,
2703 and you must not use the '$' sign to access them.
2705 To store commands and special characters in a
2706 variable, please use double quotation marks
2707 surrounding the whole text of the variable, instead
2708 of the backslashes before semicolons and special
2711 - Commandline Editing and History:
2712 CONFIG_CMDLINE_EDITING
2714 Enable editing and History functions for interactive
2715 commandline input operations
2717 - Default Environment:
2718 CONFIG_EXTRA_ENV_SETTINGS
2720 Define this to contain any number of null terminated
2721 strings (variable = value pairs) that will be part of
2722 the default environment compiled into the boot image.
2724 For example, place something like this in your
2725 board's config file:
2727 #define CONFIG_EXTRA_ENV_SETTINGS \
2731 Warning: This method is based on knowledge about the
2732 internal format how the environment is stored by the
2733 U-Boot code. This is NOT an official, exported
2734 interface! Although it is unlikely that this format
2735 will change soon, there is no guarantee either.
2736 You better know what you are doing here.
2738 Note: overly (ab)use of the default environment is
2739 discouraged. Make sure to check other ways to preset
2740 the environment like the "source" command or the
2743 CONFIG_ENV_VARS_UBOOT_CONFIG
2745 Define this in order to add variables describing the
2746 U-Boot build configuration to the default environment.
2747 These will be named arch, cpu, board, vendor, and soc.
2749 Enabling this option will cause the following to be defined:
2757 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2759 Define this in order to add variables describing certain
2760 run-time determined information about the hardware to the
2761 environment. These will be named board_name, board_rev.
2763 CONFIG_DELAY_ENVIRONMENT
2765 Normally the environment is loaded when the board is
2766 intialised so that it is available to U-Boot. This inhibits
2767 that so that the environment is not available until
2768 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2769 this is instead controlled by the value of
2770 /config/load-environment.
2772 - DataFlash Support:
2773 CONFIG_HAS_DATAFLASH
2775 Defining this option enables DataFlash features and
2776 allows to read/write in Dataflash via the standard
2779 - Serial Flash support
2782 Defining this option enables SPI flash commands
2783 'sf probe/read/write/erase/update'.
2785 Usage requires an initial 'probe' to define the serial
2786 flash parameters, followed by read/write/erase/update
2789 The following defaults may be provided by the platform
2790 to handle the common case when only a single serial
2791 flash is present on the system.
2793 CONFIG_SF_DEFAULT_BUS Bus identifier
2794 CONFIG_SF_DEFAULT_CS Chip-select
2795 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2796 CONFIG_SF_DEFAULT_SPEED in Hz
2800 Define this option to include a destructive SPI flash
2803 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2805 Define this option to use the Bank addr/Extended addr
2806 support on SPI flashes which has size > 16Mbytes.
2808 CONFIG_SF_DUAL_FLASH Dual flash memories
2810 Define this option to use dual flash support where two flash
2811 memories can be connected with a given cs line.
2812 currently Xilinx Zynq qspi support these type of connections.
2814 - SystemACE Support:
2817 Adding this option adds support for Xilinx SystemACE
2818 chips attached via some sort of local bus. The address
2819 of the chip must also be defined in the
2820 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2822 #define CONFIG_SYSTEMACE
2823 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2825 When SystemACE support is added, the "ace" device type
2826 becomes available to the fat commands, i.e. fatls.
2828 - TFTP Fixed UDP Port:
2831 If this is defined, the environment variable tftpsrcp
2832 is used to supply the TFTP UDP source port value.
2833 If tftpsrcp isn't defined, the normal pseudo-random port
2834 number generator is used.
2836 Also, the environment variable tftpdstp is used to supply
2837 the TFTP UDP destination port value. If tftpdstp isn't
2838 defined, the normal port 69 is used.
2840 The purpose for tftpsrcp is to allow a TFTP server to
2841 blindly start the TFTP transfer using the pre-configured
2842 target IP address and UDP port. This has the effect of
2843 "punching through" the (Windows XP) firewall, allowing
2844 the remainder of the TFTP transfer to proceed normally.
2845 A better solution is to properly configure the firewall,
2846 but sometimes that is not allowed.
2851 This enables a generic 'hash' command which can produce
2852 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2856 Enable the hash verify command (hash -v). This adds to code
2859 CONFIG_SHA1 - support SHA1 hashing
2860 CONFIG_SHA256 - support SHA256 hashing
2862 Note: There is also a sha1sum command, which should perhaps
2863 be deprecated in favour of 'hash sha1'.
2865 - Freescale i.MX specific commands:
2866 CONFIG_CMD_HDMIDETECT
2867 This enables 'hdmidet' command which returns true if an
2868 HDMI monitor is detected. This command is i.MX 6 specific.
2871 This enables the 'bmode' (bootmode) command for forcing
2872 a boot from specific media.
2874 This is useful for forcing the ROM's usb downloader to
2875 activate upon a watchdog reset which is nice when iterating
2876 on U-Boot. Using the reset button or running bmode normal
2877 will set it back to normal. This command currently
2878 supports i.MX53 and i.MX6.
2883 This enables the RSA algorithm used for FIT image verification
2884 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2886 The signing part is build into mkimage regardless of this
2889 - bootcount support:
2890 CONFIG_BOOTCOUNT_LIMIT
2892 This enables the bootcounter support, see:
2893 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2896 enable special bootcounter support on at91sam9xe based boards.
2898 enable special bootcounter support on blackfin based boards.
2900 enable special bootcounter support on da850 based boards.
2901 CONFIG_BOOTCOUNT_RAM
2902 enable support for the bootcounter in RAM
2903 CONFIG_BOOTCOUNT_I2C
2904 enable support for the bootcounter on an i2c (like RTC) device.
2905 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2906 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2908 CONFIG_BOOTCOUNT_ALEN = address len
2910 - Show boot progress:
2911 CONFIG_SHOW_BOOT_PROGRESS
2913 Defining this option allows to add some board-
2914 specific code (calling a user-provided function
2915 "show_boot_progress(int)") that enables you to show
2916 the system's boot progress on some display (for
2917 example, some LED's) on your board. At the moment,
2918 the following checkpoints are implemented:
2920 - Detailed boot stage timing
2922 Define this option to get detailed timing of each stage
2923 of the boot process.
2925 CONFIG_BOOTSTAGE_USER_COUNT
2926 This is the number of available user bootstage records.
2927 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2928 a new ID will be allocated from this stash. If you exceed
2929 the limit, recording will stop.
2931 CONFIG_BOOTSTAGE_REPORT
2932 Define this to print a report before boot, similar to this:
2934 Timer summary in microseconds:
2937 3,575,678 3,575,678 board_init_f start
2938 3,575,695 17 arch_cpu_init A9
2939 3,575,777 82 arch_cpu_init done
2940 3,659,598 83,821 board_init_r start
2941 3,910,375 250,777 main_loop
2942 29,916,167 26,005,792 bootm_start
2943 30,361,327 445,160 start_kernel
2945 CONFIG_CMD_BOOTSTAGE
2946 Add a 'bootstage' command which supports printing a report
2947 and un/stashing of bootstage data.
2949 CONFIG_BOOTSTAGE_FDT
2950 Stash the bootstage information in the FDT. A root 'bootstage'
2951 node is created with each bootstage id as a child. Each child
2952 has a 'name' property and either 'mark' containing the
2953 mark time in microsecond, or 'accum' containing the
2954 accumulated time for that bootstage id in microseconds.
2959 name = "board_init_f";
2968 Code in the Linux kernel can find this in /proc/devicetree.
2970 Legacy uImage format:
2973 1 common/cmd_bootm.c before attempting to boot an image
2974 -1 common/cmd_bootm.c Image header has bad magic number
2975 2 common/cmd_bootm.c Image header has correct magic number
2976 -2 common/cmd_bootm.c Image header has bad checksum
2977 3 common/cmd_bootm.c Image header has correct checksum
2978 -3 common/cmd_bootm.c Image data has bad checksum
2979 4 common/cmd_bootm.c Image data has correct checksum
2980 -4 common/cmd_bootm.c Image is for unsupported architecture
2981 5 common/cmd_bootm.c Architecture check OK
2982 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2983 6 common/cmd_bootm.c Image Type check OK
2984 -6 common/cmd_bootm.c gunzip uncompression error
2985 -7 common/cmd_bootm.c Unimplemented compression type
2986 7 common/cmd_bootm.c Uncompression OK
2987 8 common/cmd_bootm.c No uncompress/copy overwrite error
2988 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2990 9 common/image.c Start initial ramdisk verification
2991 -10 common/image.c Ramdisk header has bad magic number
2992 -11 common/image.c Ramdisk header has bad checksum
2993 10 common/image.c Ramdisk header is OK
2994 -12 common/image.c Ramdisk data has bad checksum
2995 11 common/image.c Ramdisk data has correct checksum
2996 12 common/image.c Ramdisk verification complete, start loading
2997 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2998 13 common/image.c Start multifile image verification
2999 14 common/image.c No initial ramdisk, no multifile, continue.
3001 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3003 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3004 -31 post/post.c POST test failed, detected by post_output_backlog()
3005 -32 post/post.c POST test failed, detected by post_run_single()
3007 34 common/cmd_doc.c before loading a Image from a DOC device
3008 -35 common/cmd_doc.c Bad usage of "doc" command
3009 35 common/cmd_doc.c correct usage of "doc" command
3010 -36 common/cmd_doc.c No boot device
3011 36 common/cmd_doc.c correct boot device
3012 -37 common/cmd_doc.c Unknown Chip ID on boot device
3013 37 common/cmd_doc.c correct chip ID found, device available
3014 -38 common/cmd_doc.c Read Error on boot device
3015 38 common/cmd_doc.c reading Image header from DOC device OK
3016 -39 common/cmd_doc.c Image header has bad magic number
3017 39 common/cmd_doc.c Image header has correct magic number
3018 -40 common/cmd_doc.c Error reading Image from DOC device
3019 40 common/cmd_doc.c Image header has correct magic number
3020 41 common/cmd_ide.c before loading a Image from a IDE device
3021 -42 common/cmd_ide.c Bad usage of "ide" command
3022 42 common/cmd_ide.c correct usage of "ide" command
3023 -43 common/cmd_ide.c No boot device
3024 43 common/cmd_ide.c boot device found
3025 -44 common/cmd_ide.c Device not available
3026 44 common/cmd_ide.c Device available
3027 -45 common/cmd_ide.c wrong partition selected
3028 45 common/cmd_ide.c partition selected
3029 -46 common/cmd_ide.c Unknown partition table
3030 46 common/cmd_ide.c valid partition table found
3031 -47 common/cmd_ide.c Invalid partition type
3032 47 common/cmd_ide.c correct partition type
3033 -48 common/cmd_ide.c Error reading Image Header on boot device
3034 48 common/cmd_ide.c reading Image Header from IDE device OK
3035 -49 common/cmd_ide.c Image header has bad magic number
3036 49 common/cmd_ide.c Image header has correct magic number
3037 -50 common/cmd_ide.c Image header has bad checksum
3038 50 common/cmd_ide.c Image header has correct checksum
3039 -51 common/cmd_ide.c Error reading Image from IDE device
3040 51 common/cmd_ide.c reading Image from IDE device OK
3041 52 common/cmd_nand.c before loading a Image from a NAND device
3042 -53 common/cmd_nand.c Bad usage of "nand" command
3043 53 common/cmd_nand.c correct usage of "nand" command
3044 -54 common/cmd_nand.c No boot device
3045 54 common/cmd_nand.c boot device found
3046 -55 common/cmd_nand.c Unknown Chip ID on boot device
3047 55 common/cmd_nand.c correct chip ID found, device available
3048 -56 common/cmd_nand.c Error reading Image Header on boot device
3049 56 common/cmd_nand.c reading Image Header from NAND device OK
3050 -57 common/cmd_nand.c Image header has bad magic number
3051 57 common/cmd_nand.c Image header has correct magic number
3052 -58 common/cmd_nand.c Error reading Image from NAND device
3053 58 common/cmd_nand.c reading Image from NAND device OK
3055 -60 common/env_common.c Environment has a bad CRC, using default
3057 64 net/eth.c starting with Ethernet configuration.
3058 -64 net/eth.c no Ethernet found.
3059 65 net/eth.c Ethernet found.
3061 -80 common/cmd_net.c usage wrong
3062 80 common/cmd_net.c before calling NetLoop()
3063 -81 common/cmd_net.c some error in NetLoop() occurred
3064 81 common/cmd_net.c NetLoop() back without error
3065 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3066 82 common/cmd_net.c trying automatic boot
3067 83 common/cmd_net.c running "source" command
3068 -83 common/cmd_net.c some error in automatic boot or "source" command
3069 84 common/cmd_net.c end without errors
3074 100 common/cmd_bootm.c Kernel FIT Image has correct format
3075 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3076 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3077 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3078 102 common/cmd_bootm.c Kernel unit name specified
3079 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3080 103 common/cmd_bootm.c Found configuration node
3081 104 common/cmd_bootm.c Got kernel subimage node offset
3082 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3083 105 common/cmd_bootm.c Kernel subimage hash verification OK
3084 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3085 106 common/cmd_bootm.c Architecture check OK
3086 -106 common/cmd_bootm.c Kernel subimage has wrong type
3087 107 common/cmd_bootm.c Kernel subimage type OK
3088 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3089 108 common/cmd_bootm.c Got kernel subimage data/size
3090 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3091 -109 common/cmd_bootm.c Can't get kernel subimage type
3092 -110 common/cmd_bootm.c Can't get kernel subimage comp
3093 -111 common/cmd_bootm.c Can't get kernel subimage os
3094 -112 common/cmd_bootm.c Can't get kernel subimage load address
3095 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3097 120 common/image.c Start initial ramdisk verification
3098 -120 common/image.c Ramdisk FIT image has incorrect format
3099 121 common/image.c Ramdisk FIT image has correct format
3100 122 common/image.c No ramdisk subimage unit name, using configuration
3101 -122 common/image.c Can't get configuration for ramdisk subimage
3102 123 common/image.c Ramdisk unit name specified
3103 -124 common/image.c Can't get ramdisk subimage node offset
3104 125 common/image.c Got ramdisk subimage node offset
3105 -125 common/image.c Ramdisk subimage hash verification failed
3106 126 common/image.c Ramdisk subimage hash verification OK
3107 -126 common/image.c Ramdisk subimage for unsupported architecture
3108 127 common/image.c Architecture check OK
3109 -127 common/image.c Can't get ramdisk subimage data/size
3110 128 common/image.c Got ramdisk subimage data/size
3111 129 common/image.c Can't get ramdisk load address
3112 -129 common/image.c Got ramdisk load address
3114 -130 common/cmd_doc.c Incorrect FIT image format
3115 131 common/cmd_doc.c FIT image format OK
3117 -140 common/cmd_ide.c Incorrect FIT image format
3118 141 common/cmd_ide.c FIT image format OK
3120 -150 common/cmd_nand.c Incorrect FIT image format
3121 151 common/cmd_nand.c FIT image format OK
3123 - FIT image support:
3125 Enable support for the FIT uImage format.
3127 CONFIG_FIT_BEST_MATCH
3128 When no configuration is explicitly selected, default to the
3129 one whose fdt's compatibility field best matches that of
3130 U-Boot itself. A match is considered "best" if it matches the
3131 most specific compatibility entry of U-Boot's fdt's root node.
3132 The order of entries in the configuration's fdt is ignored.
3134 CONFIG_FIT_SIGNATURE
3135 This option enables signature verification of FIT uImages,
3136 using a hash signed and verified using RSA. See
3137 doc/uImage.FIT/signature.txt for more details.
3139 - Standalone program support:
3140 CONFIG_STANDALONE_LOAD_ADDR
3142 This option defines a board specific value for the
3143 address where standalone program gets loaded, thus
3144 overwriting the architecture dependent default
3147 - Frame Buffer Address:
3150 Define CONFIG_FB_ADDR if you want to use specific
3151 address for frame buffer. This is typically the case
3152 when using a graphics controller has separate video
3153 memory. U-Boot will then place the frame buffer at
3154 the given address instead of dynamically reserving it
3155 in system RAM by calling lcd_setmem(), which grabs
3156 the memory for the frame buffer depending on the
3157 configured panel size.
3159 Please see board_init_f function.
3161 - Automatic software updates via TFTP server
3163 CONFIG_UPDATE_TFTP_CNT_MAX
3164 CONFIG_UPDATE_TFTP_MSEC_MAX
3166 These options enable and control the auto-update feature;
3167 for a more detailed description refer to doc/README.update.
3169 - MTD Support (mtdparts command, UBI support)
3172 Adds the MTD device infrastructure from the Linux kernel.
3173 Needed for mtdparts command support.
3175 CONFIG_MTD_PARTITIONS
3177 Adds the MTD partitioning infrastructure from the Linux
3178 kernel. Needed for UBI support.
3183 Adds commands for interacting with MTD partitions formatted
3184 with the UBI flash translation layer
3186 Requires also defining CONFIG_RBTREE
3188 CONFIG_UBI_SILENCE_MSG
3190 Make the verbose messages from UBI stop printing. This leaves
3191 warnings and errors enabled.
3196 Adds commands for interacting with UBI volumes formatted as
3197 UBIFS. UBIFS is read-only in u-boot.
3199 Requires UBI support as well as CONFIG_LZO
3201 CONFIG_UBIFS_SILENCE_MSG
3203 Make the verbose messages from UBIFS stop printing. This leaves
3204 warnings and errors enabled.
3208 Enable building of SPL globally.
3211 LDSCRIPT for linking the SPL binary.
3213 CONFIG_SPL_MAX_FOOTPRINT
3214 Maximum size in memory allocated to the SPL, BSS included.
3215 When defined, the linker checks that the actual memory
3216 used by SPL from _start to __bss_end does not exceed it.
3217 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3218 must not be both defined at the same time.
3221 Maximum size of the SPL image (text, data, rodata, and
3222 linker lists sections), BSS excluded.
3223 When defined, the linker checks that the actual size does
3226 CONFIG_SPL_TEXT_BASE
3227 TEXT_BASE for linking the SPL binary.
3229 CONFIG_SPL_RELOC_TEXT_BASE
3230 Address to relocate to. If unspecified, this is equal to
3231 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3233 CONFIG_SPL_BSS_START_ADDR
3234 Link address for the BSS within the SPL binary.
3236 CONFIG_SPL_BSS_MAX_SIZE
3237 Maximum size in memory allocated to the SPL BSS.
3238 When defined, the linker checks that the actual memory used
3239 by SPL from __bss_start to __bss_end does not exceed it.
3240 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3241 must not be both defined at the same time.
3244 Adress of the start of the stack SPL will use
3246 CONFIG_SPL_RELOC_STACK
3247 Adress of the start of the stack SPL will use after
3248 relocation. If unspecified, this is equal to
3251 CONFIG_SYS_SPL_MALLOC_START
3252 Starting address of the malloc pool used in SPL.
3254 CONFIG_SYS_SPL_MALLOC_SIZE
3255 The size of the malloc pool used in SPL.
3257 CONFIG_SPL_FRAMEWORK
3258 Enable the SPL framework under common/. This framework
3259 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3260 NAND loading of the Linux Kernel.
3262 CONFIG_SPL_DISPLAY_PRINT
3263 For ARM, enable an optional function to print more information
3264 about the running system.
3266 CONFIG_SPL_INIT_MINIMAL
3267 Arch init code should be built for a very small image
3269 CONFIG_SPL_LIBCOMMON_SUPPORT
3270 Support for common/libcommon.o in SPL binary
3272 CONFIG_SPL_LIBDISK_SUPPORT
3273 Support for disk/libdisk.o in SPL binary
3275 CONFIG_SPL_I2C_SUPPORT
3276 Support for drivers/i2c/libi2c.o in SPL binary
3278 CONFIG_SPL_GPIO_SUPPORT
3279 Support for drivers/gpio/libgpio.o in SPL binary
3281 CONFIG_SPL_MMC_SUPPORT
3282 Support for drivers/mmc/libmmc.o in SPL binary
3284 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3285 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3286 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3287 Address, size and partition on the MMC to load U-Boot from
3288 when the MMC is being used in raw mode.
3290 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3291 Sector to load kernel uImage from when MMC is being
3292 used in raw mode (for Falcon mode)
3294 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3295 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3296 Sector and number of sectors to load kernel argument
3297 parameters from when MMC is being used in raw mode
3300 CONFIG_SPL_FAT_SUPPORT
3301 Support for fs/fat/libfat.o in SPL binary
3303 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3304 Filename to read to load U-Boot when reading from FAT
3306 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3307 Filename to read to load kernel uImage when reading
3308 from FAT (for Falcon mode)
3310 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3311 Filename to read to load kernel argument parameters
3312 when reading from FAT (for Falcon mode)
3314 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3315 Set this for NAND SPL on PPC mpc83xx targets, so that
3316 start.S waits for the rest of the SPL to load before
3317 continuing (the hardware starts execution after just
3318 loading the first page rather than the full 4K).
3320 CONFIG_SPL_NAND_BASE
3321 Include nand_base.c in the SPL. Requires
3322 CONFIG_SPL_NAND_DRIVERS.
3324 CONFIG_SPL_NAND_DRIVERS
3325 SPL uses normal NAND drivers, not minimal drivers.
3328 Include standard software ECC in the SPL
3330 CONFIG_SPL_NAND_SIMPLE
3331 Support for NAND boot using simple NAND drivers that
3332 expose the cmd_ctrl() interface.
3334 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3335 Set for the SPL on PPC mpc8xxx targets, support for
3336 drivers/ddr/fsl/libddr.o in SPL binary.
3338 CONFIG_SPL_COMMON_INIT_DDR
3339 Set for common ddr init with serial presence detect in
3342 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3343 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3344 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3345 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3346 CONFIG_SYS_NAND_ECCBYTES
3347 Defines the size and behavior of the NAND that SPL uses
3350 CONFIG_SPL_NAND_BOOT
3351 Add support NAND boot
3353 CONFIG_SYS_NAND_U_BOOT_OFFS
3354 Location in NAND to read U-Boot from
3356 CONFIG_SYS_NAND_U_BOOT_DST
3357 Location in memory to load U-Boot to
3359 CONFIG_SYS_NAND_U_BOOT_SIZE
3360 Size of image to load
3362 CONFIG_SYS_NAND_U_BOOT_START
3363 Entry point in loaded image to jump to
3365 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3366 Define this if you need to first read the OOB and then the
3367 data. This is used for example on davinci plattforms.
3369 CONFIG_SPL_OMAP3_ID_NAND
3370 Support for an OMAP3-specific set of functions to return the
3371 ID and MFR of the first attached NAND chip, if present.
3373 CONFIG_SPL_SERIAL_SUPPORT
3374 Support for drivers/serial/libserial.o in SPL binary
3376 CONFIG_SPL_SPI_FLASH_SUPPORT
3377 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3379 CONFIG_SPL_SPI_SUPPORT
3380 Support for drivers/spi/libspi.o in SPL binary
3382 CONFIG_SPL_RAM_DEVICE
3383 Support for running image already present in ram, in SPL binary
3385 CONFIG_SPL_LIBGENERIC_SUPPORT
3386 Support for lib/libgeneric.o in SPL binary
3388 CONFIG_SPL_ENV_SUPPORT
3389 Support for the environment operating in SPL binary
3391 CONFIG_SPL_NET_SUPPORT
3392 Support for the net/libnet.o in SPL binary.
3393 It conflicts with SPL env from storage medium specified by
3394 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3397 Image offset to which the SPL should be padded before appending
3398 the SPL payload. By default, this is defined as
3399 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3400 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3401 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3404 Final target image containing SPL and payload. Some SPLs
3405 use an arch-specific makefile fragment instead, for
3406 example if more than one image needs to be produced.
3408 CONFIG_FIT_SPL_PRINT
3409 Printing information about a FIT image adds quite a bit of
3410 code to SPL. So this is normally disabled in SPL. Use this
3411 option to re-enable it. This will affect the output of the
3412 bootm command when booting a FIT image.
3416 Enable building of TPL globally.
3419 Image offset to which the TPL should be padded before appending
3420 the TPL payload. By default, this is defined as
3421 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3422 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3423 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3428 [so far only for SMDK2400 boards]
3430 - Modem support enable:
3431 CONFIG_MODEM_SUPPORT
3433 - RTS/CTS Flow control enable:
3436 - Modem debug support:
3437 CONFIG_MODEM_SUPPORT_DEBUG
3439 Enables debugging stuff (char screen[1024], dbg())
3440 for modem support. Useful only with BDI2000.
3442 - Interrupt support (PPC):
3444 There are common interrupt_init() and timer_interrupt()
3445 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3446 for CPU specific initialization. interrupt_init_cpu()
3447 should set decrementer_count to appropriate value. If
3448 CPU resets decrementer automatically after interrupt
3449 (ppc4xx) it should set decrementer_count to zero.
3450 timer_interrupt() calls timer_interrupt_cpu() for CPU
3451 specific handling. If board has watchdog / status_led
3452 / other_activity_monitor it works automatically from
3453 general timer_interrupt().
3457 In the target system modem support is enabled when a
3458 specific key (key combination) is pressed during
3459 power-on. Otherwise U-Boot will boot normally
3460 (autoboot). The key_pressed() function is called from
3461 board_init(). Currently key_pressed() is a dummy
3462 function, returning 1 and thus enabling modem
3465 If there are no modem init strings in the
3466 environment, U-Boot proceed to autoboot; the
3467 previous output (banner, info printfs) will be
3470 See also: doc/README.Modem
3472 Board initialization settings:
3473 ------------------------------
3475 During Initialization u-boot calls a number of board specific functions
3476 to allow the preparation of board specific prerequisites, e.g. pin setup
3477 before drivers are initialized. To enable these callbacks the
3478 following configuration macros have to be defined. Currently this is
3479 architecture specific, so please check arch/your_architecture/lib/board.c
3480 typically in board_init_f() and board_init_r().
3482 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3483 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3484 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3485 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3487 Configuration Settings:
3488 -----------------------
3490 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3491 Optionally it can be defined to support 64-bit memory commands.
3493 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3494 undefine this when you're short of memory.
3496 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3497 width of the commands listed in the 'help' command output.
3499 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3500 prompt for user input.
3502 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3504 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3506 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3508 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3509 the application (usually a Linux kernel) when it is
3512 - CONFIG_SYS_BAUDRATE_TABLE:
3513 List of legal baudrate settings for this board.
3515 - CONFIG_SYS_CONSOLE_INFO_QUIET
3516 Suppress display of console information at boot.
3518 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3519 If the board specific function
3520 extern int overwrite_console (void);
3521 returns 1, the stdin, stderr and stdout are switched to the
3522 serial port, else the settings in the environment are used.
3524 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3525 Enable the call to overwrite_console().
3527 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3528 Enable overwrite of previous console environment settings.
3530 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3531 Begin and End addresses of the area used by the
3534 - CONFIG_SYS_ALT_MEMTEST:
3535 Enable an alternate, more extensive memory test.
3537 - CONFIG_SYS_MEMTEST_SCRATCH:
3538 Scratch address used by the alternate memory test
3539 You only need to set this if address zero isn't writeable
3541 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3542 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3543 this specified memory area will get subtracted from the top
3544 (end) of RAM and won't get "touched" at all by U-Boot. By
3545 fixing up gd->ram_size the Linux kernel should gets passed
3546 the now "corrected" memory size and won't touch it either.
3547 This should work for arch/ppc and arch/powerpc. Only Linux
3548 board ports in arch/powerpc with bootwrapper support that
3549 recalculate the memory size from the SDRAM controller setup
3550 will have to get fixed in Linux additionally.
3552 This option can be used as a workaround for the 440EPx/GRx
3553 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3556 WARNING: Please make sure that this value is a multiple of
3557 the Linux page size (normally 4k). If this is not the case,
3558 then the end address of the Linux memory will be located at a
3559 non page size aligned address and this could cause major
3562 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3563 Enable temporary baudrate change while serial download
3565 - CONFIG_SYS_SDRAM_BASE:
3566 Physical start address of SDRAM. _Must_ be 0 here.
3568 - CONFIG_SYS_MBIO_BASE:
3569 Physical start address of Motherboard I/O (if using a
3572 - CONFIG_SYS_FLASH_BASE:
3573 Physical start address of Flash memory.
3575 - CONFIG_SYS_MONITOR_BASE:
3576 Physical start address of boot monitor code (set by
3577 make config files to be same as the text base address
3578 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3579 CONFIG_SYS_FLASH_BASE when booting from flash.
3581 - CONFIG_SYS_MONITOR_LEN:
3582 Size of memory reserved for monitor code, used to
3583 determine _at_compile_time_ (!) if the environment is
3584 embedded within the U-Boot image, or in a separate
3587 - CONFIG_SYS_MALLOC_LEN:
3588 Size of DRAM reserved for malloc() use.
3590 - CONFIG_SYS_BOOTM_LEN:
3591 Normally compressed uImages are limited to an
3592 uncompressed size of 8 MBytes. If this is not enough,
3593 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3594 to adjust this setting to your needs.
3596 - CONFIG_SYS_BOOTMAPSZ:
3597 Maximum size of memory mapped by the startup code of
3598 the Linux kernel; all data that must be processed by
3599 the Linux kernel (bd_info, boot arguments, FDT blob if
3600 used) must be put below this limit, unless "bootm_low"
3601 environment variable is defined and non-zero. In such case
3602 all data for the Linux kernel must be between "bootm_low"
3603 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3604 variable "bootm_mapsize" will override the value of
3605 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3606 then the value in "bootm_size" will be used instead.
3608 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3609 Enable initrd_high functionality. If defined then the
3610 initrd_high feature is enabled and the bootm ramdisk subcommand
3613 - CONFIG_SYS_BOOT_GET_CMDLINE:
3614 Enables allocating and saving kernel cmdline in space between
3615 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3617 - CONFIG_SYS_BOOT_GET_KBD:
3618 Enables allocating and saving a kernel copy of the bd_info in
3619 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3621 - CONFIG_SYS_MAX_FLASH_BANKS:
3622 Max number of Flash memory banks
3624 - CONFIG_SYS_MAX_FLASH_SECT:
3625 Max number of sectors on a Flash chip
3627 - CONFIG_SYS_FLASH_ERASE_TOUT:
3628 Timeout for Flash erase operations (in ms)
3630 - CONFIG_SYS_FLASH_WRITE_TOUT:
3631 Timeout for Flash write operations (in ms)
3633 - CONFIG_SYS_FLASH_LOCK_TOUT
3634 Timeout for Flash set sector lock bit operation (in ms)
3636 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3637 Timeout for Flash clear lock bits operation (in ms)
3639 - CONFIG_SYS_FLASH_PROTECTION
3640 If defined, hardware flash sectors protection is used
3641 instead of U-Boot software protection.
3643 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3645 Enable TFTP transfers directly to flash memory;
3646 without this option such a download has to be
3647 performed in two steps: (1) download to RAM, and (2)
3648 copy from RAM to flash.
3650 The two-step approach is usually more reliable, since
3651 you can check if the download worked before you erase
3652 the flash, but in some situations (when system RAM is
3653 too limited to allow for a temporary copy of the
3654 downloaded image) this option may be very useful.
3656 - CONFIG_SYS_FLASH_CFI:
3657 Define if the flash driver uses extra elements in the
3658 common flash structure for storing flash geometry.
3660 - CONFIG_FLASH_CFI_DRIVER
3661 This option also enables the building of the cfi_flash driver
3662 in the drivers directory
3664 - CONFIG_FLASH_CFI_MTD
3665 This option enables the building of the cfi_mtd driver
3666 in the drivers directory. The driver exports CFI flash
3669 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3670 Use buffered writes to flash.
3672 - CONFIG_FLASH_SPANSION_S29WS_N
3673 s29ws-n MirrorBit flash has non-standard addresses for buffered
3676 - CONFIG_SYS_FLASH_QUIET_TEST
3677 If this option is defined, the common CFI flash doesn't
3678 print it's warning upon not recognized FLASH banks. This
3679 is useful, if some of the configured banks are only
3680 optionally available.
3682 - CONFIG_FLASH_SHOW_PROGRESS
3683 If defined (must be an integer), print out countdown
3684 digits and dots. Recommended value: 45 (9..1) for 80
3685 column displays, 15 (3..1) for 40 column displays.
3687 - CONFIG_FLASH_VERIFY
3688 If defined, the content of the flash (destination) is compared
3689 against the source after the write operation. An error message
3690 will be printed when the contents are not identical.
3691 Please note that this option is useless in nearly all cases,
3692 since such flash programming errors usually are detected earlier
3693 while unprotecting/erasing/programming. Please only enable
3694 this option if you really know what you are doing.
3696 - CONFIG_SYS_RX_ETH_BUFFER:
3697 Defines the number of Ethernet receive buffers. On some
3698 Ethernet controllers it is recommended to set this value
3699 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3700 buffers can be full shortly after enabling the interface
3701 on high Ethernet traffic.
3702 Defaults to 4 if not defined.
3704 - CONFIG_ENV_MAX_ENTRIES
3706 Maximum number of entries in the hash table that is used
3707 internally to store the environment settings. The default
3708 setting is supposed to be generous and should work in most
3709 cases. This setting can be used to tune behaviour; see
3710 lib/hashtable.c for details.
3712 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3713 - CONFIG_ENV_FLAGS_LIST_STATIC
3714 Enable validation of the values given to environment variables when
3715 calling env set. Variables can be restricted to only decimal,
3716 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3717 the variables can also be restricted to IP address or MAC address.
3719 The format of the list is:
3720 type_attribute = [s|d|x|b|i|m]
3721 access_atribute = [a|r|o|c]
3722 attributes = type_attribute[access_atribute]
3723 entry = variable_name[:attributes]
3726 The type attributes are:
3727 s - String (default)
3730 b - Boolean ([1yYtT|0nNfF])
3734 The access attributes are:
3740 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3741 Define this to a list (string) to define the ".flags"
3742 envirnoment variable in the default or embedded environment.
3744 - CONFIG_ENV_FLAGS_LIST_STATIC
3745 Define this to a list (string) to define validation that
3746 should be done if an entry is not found in the ".flags"
3747 environment variable. To override a setting in the static
3748 list, simply add an entry for the same variable name to the
3751 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3752 If defined, don't allow the -f switch to env set override variable
3755 - CONFIG_SYS_GENERIC_BOARD
3756 This selects the architecture-generic board system instead of the
3757 architecture-specific board files. It is intended to move boards
3758 to this new framework over time. Defining this will disable the
3759 arch/foo/lib/board.c file and use common/board_f.c and
3760 common/board_r.c instead. To use this option your architecture
3761 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3762 its config.mk file). If you find problems enabling this option on
3763 your board please report the problem and send patches!
3765 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3766 This is set by OMAP boards for the max time that reset should
3767 be asserted. See doc/README.omap-reset-time for details on how
3768 the value can be calulated on a given board.
3770 The following definitions that deal with the placement and management
3771 of environment data (variable area); in general, we support the
3772 following configurations:
3774 - CONFIG_BUILD_ENVCRC:
3776 Builds up envcrc with the target environment so that external utils
3777 may easily extract it and embed it in final U-Boot images.
3779 - CONFIG_ENV_IS_IN_FLASH:
3781 Define this if the environment is in flash memory.
3783 a) The environment occupies one whole flash sector, which is
3784 "embedded" in the text segment with the U-Boot code. This
3785 happens usually with "bottom boot sector" or "top boot
3786 sector" type flash chips, which have several smaller
3787 sectors at the start or the end. For instance, such a
3788 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3789 such a case you would place the environment in one of the
3790 4 kB sectors - with U-Boot code before and after it. With
3791 "top boot sector" type flash chips, you would put the
3792 environment in one of the last sectors, leaving a gap
3793 between U-Boot and the environment.
3795 - CONFIG_ENV_OFFSET:
3797 Offset of environment data (variable area) to the
3798 beginning of flash memory; for instance, with bottom boot
3799 type flash chips the second sector can be used: the offset
3800 for this sector is given here.
3802 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3806 This is just another way to specify the start address of
3807 the flash sector containing the environment (instead of
3810 - CONFIG_ENV_SECT_SIZE:
3812 Size of the sector containing the environment.
3815 b) Sometimes flash chips have few, equal sized, BIG sectors.
3816 In such a case you don't want to spend a whole sector for
3821 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3822 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3823 of this flash sector for the environment. This saves
3824 memory for the RAM copy of the environment.
3826 It may also save flash memory if you decide to use this
3827 when your environment is "embedded" within U-Boot code,
3828 since then the remainder of the flash sector could be used
3829 for U-Boot code. It should be pointed out that this is
3830 STRONGLY DISCOURAGED from a robustness point of view:
3831 updating the environment in flash makes it always
3832 necessary to erase the WHOLE sector. If something goes
3833 wrong before the contents has been restored from a copy in
3834 RAM, your target system will be dead.
3836 - CONFIG_ENV_ADDR_REDUND
3837 CONFIG_ENV_SIZE_REDUND
3839 These settings describe a second storage area used to hold
3840 a redundant copy of the environment data, so that there is
3841 a valid backup copy in case there is a power failure during
3842 a "saveenv" operation.
3844 BE CAREFUL! Any changes to the flash layout, and some changes to the
3845 source code will make it necessary to adapt <board>/u-boot.lds*
3849 - CONFIG_ENV_IS_IN_NVRAM:
3851 Define this if you have some non-volatile memory device
3852 (NVRAM, battery buffered SRAM) which you want to use for the
3858 These two #defines are used to determine the memory area you
3859 want to use for environment. It is assumed that this memory
3860 can just be read and written to, without any special
3863 BE CAREFUL! The first access to the environment happens quite early
3864 in U-Boot initalization (when we try to get the setting of for the
3865 console baudrate). You *MUST* have mapped your NVRAM area then, or
3868 Please note that even with NVRAM we still use a copy of the
3869 environment in RAM: we could work on NVRAM directly, but we want to
3870 keep settings there always unmodified except somebody uses "saveenv"
3871 to save the current settings.
3874 - CONFIG_ENV_IS_IN_EEPROM:
3876 Use this if you have an EEPROM or similar serial access
3877 device and a driver for it.
3879 - CONFIG_ENV_OFFSET:
3882 These two #defines specify the offset and size of the
3883 environment area within the total memory of your EEPROM.
3885 - CONFIG_SYS_I2C_EEPROM_ADDR:
3886 If defined, specified the chip address of the EEPROM device.
3887 The default address is zero.
3889 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3890 If defined, the number of bits used to address bytes in a
3891 single page in the EEPROM device. A 64 byte page, for example
3892 would require six bits.
3894 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3895 If defined, the number of milliseconds to delay between
3896 page writes. The default is zero milliseconds.
3898 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3899 The length in bytes of the EEPROM memory array address. Note
3900 that this is NOT the chip address length!
3902 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3903 EEPROM chips that implement "address overflow" are ones
3904 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3905 address and the extra bits end up in the "chip address" bit
3906 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3909 Note that we consider the length of the address field to
3910 still be one byte because the extra address bits are hidden
3911 in the chip address.
3913 - CONFIG_SYS_EEPROM_SIZE:
3914 The size in bytes of the EEPROM device.
3916 - CONFIG_ENV_EEPROM_IS_ON_I2C
3917 define this, if you have I2C and SPI activated, and your
3918 EEPROM, which holds the environment, is on the I2C bus.
3920 - CONFIG_I2C_ENV_EEPROM_BUS
3921 if you have an Environment on an EEPROM reached over
3922 I2C muxes, you can define here, how to reach this
3923 EEPROM. For example:
3925 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3927 EEPROM which holds the environment, is reached over
3928 a pca9547 i2c mux with address 0x70, channel 3.
3930 - CONFIG_ENV_IS_IN_DATAFLASH:
3932 Define this if you have a DataFlash memory device which you
3933 want to use for the environment.
3935 - CONFIG_ENV_OFFSET:
3939 These three #defines specify the offset and size of the
3940 environment area within the total memory of your DataFlash placed
3941 at the specified address.
3943 - CONFIG_ENV_IS_IN_REMOTE:
3945 Define this if you have a remote memory space which you
3946 want to use for the local device's environment.
3951 These two #defines specify the address and size of the
3952 environment area within the remote memory space. The
3953 local device can get the environment from remote memory
3954 space by SRIO or PCIE links.
3956 BE CAREFUL! For some special cases, the local device can not use
3957 "saveenv" command. For example, the local device will get the
3958 environment stored in a remote NOR flash by SRIO or PCIE link,
3959 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3961 - CONFIG_ENV_IS_IN_NAND:
3963 Define this if you have a NAND device which you want to use
3964 for the environment.
3966 - CONFIG_ENV_OFFSET:
3969 These two #defines specify the offset and size of the environment
3970 area within the first NAND device. CONFIG_ENV_OFFSET must be
3971 aligned to an erase block boundary.
3973 - CONFIG_ENV_OFFSET_REDUND (optional):
3975 This setting describes a second storage area of CONFIG_ENV_SIZE
3976 size used to hold a redundant copy of the environment data, so
3977 that there is a valid backup copy in case there is a power failure
3978 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3979 aligned to an erase block boundary.
3981 - CONFIG_ENV_RANGE (optional):
3983 Specifies the length of the region in which the environment
3984 can be written. This should be a multiple of the NAND device's
3985 block size. Specifying a range with more erase blocks than
3986 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3987 the range to be avoided.
3989 - CONFIG_ENV_OFFSET_OOB (optional):
3991 Enables support for dynamically retrieving the offset of the
3992 environment from block zero's out-of-band data. The
3993 "nand env.oob" command can be used to record this offset.
3994 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3995 using CONFIG_ENV_OFFSET_OOB.
3997 - CONFIG_NAND_ENV_DST
3999 Defines address in RAM to which the nand_spl code should copy the
4000 environment. If redundant environment is used, it will be copied to
4001 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4003 - CONFIG_ENV_IS_IN_UBI:
4005 Define this if you have an UBI volume that you want to use for the
4006 environment. This has the benefit of wear-leveling the environment
4007 accesses, which is important on NAND.
4009 - CONFIG_ENV_UBI_PART:
4011 Define this to a string that is the mtd partition containing the UBI.
4013 - CONFIG_ENV_UBI_VOLUME:
4015 Define this to the name of the volume that you want to store the
4018 - CONFIG_ENV_UBI_VOLUME_REDUND:
4020 Define this to the name of another volume to store a second copy of
4021 the environment in. This will enable redundant environments in UBI.
4022 It is assumed that both volumes are in the same MTD partition.
4024 - CONFIG_UBI_SILENCE_MSG
4025 - CONFIG_UBIFS_SILENCE_MSG
4027 You will probably want to define these to avoid a really noisy system
4028 when storing the env in UBI.
4030 - CONFIG_ENV_IS_IN_MMC:
4032 Define this if you have an MMC device which you want to use for the
4035 - CONFIG_SYS_MMC_ENV_DEV:
4037 Specifies which MMC device the environment is stored in.
4039 - CONFIG_SYS_MMC_ENV_PART (optional):
4041 Specifies which MMC partition the environment is stored in. If not
4042 set, defaults to partition 0, the user area. Common values might be
4043 1 (first MMC boot partition), 2 (second MMC boot partition).
4045 - CONFIG_ENV_OFFSET:
4048 These two #defines specify the offset and size of the environment
4049 area within the specified MMC device.
4051 If offset is positive (the usual case), it is treated as relative to
4052 the start of the MMC partition. If offset is negative, it is treated
4053 as relative to the end of the MMC partition. This can be useful if
4054 your board may be fitted with different MMC devices, which have
4055 different sizes for the MMC partitions, and you always want the
4056 environment placed at the very end of the partition, to leave the
4057 maximum possible space before it, to store other data.
4059 These two values are in units of bytes, but must be aligned to an
4060 MMC sector boundary.
4062 - CONFIG_ENV_OFFSET_REDUND (optional):
4064 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4065 hold a redundant copy of the environment data. This provides a
4066 valid backup copy in case the other copy is corrupted, e.g. due
4067 to a power failure during a "saveenv" operation.
4069 This value may also be positive or negative; this is handled in the
4070 same way as CONFIG_ENV_OFFSET.
4072 This value is also in units of bytes, but must also be aligned to
4073 an MMC sector boundary.
4075 - CONFIG_ENV_SIZE_REDUND (optional):
4077 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4078 set. If this value is set, it must be set to the same value as
4081 - CONFIG_SYS_SPI_INIT_OFFSET
4083 Defines offset to the initial SPI buffer area in DPRAM. The
4084 area is used at an early stage (ROM part) if the environment
4085 is configured to reside in the SPI EEPROM: We need a 520 byte
4086 scratch DPRAM area. It is used between the two initialization
4087 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4088 to be a good choice since it makes it far enough from the
4089 start of the data area as well as from the stack pointer.
4091 Please note that the environment is read-only until the monitor
4092 has been relocated to RAM and a RAM copy of the environment has been
4093 created; also, when using EEPROM you will have to use getenv_f()
4094 until then to read environment variables.
4096 The environment is protected by a CRC32 checksum. Before the monitor
4097 is relocated into RAM, as a result of a bad CRC you will be working
4098 with the compiled-in default environment - *silently*!!! [This is
4099 necessary, because the first environment variable we need is the
4100 "baudrate" setting for the console - if we have a bad CRC, we don't
4101 have any device yet where we could complain.]
4103 Note: once the monitor has been relocated, then it will complain if
4104 the default environment is used; a new CRC is computed as soon as you
4105 use the "saveenv" command to store a valid environment.
4107 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4108 Echo the inverted Ethernet link state to the fault LED.
4110 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4111 also needs to be defined.
4113 - CONFIG_SYS_FAULT_MII_ADDR:
4114 MII address of the PHY to check for the Ethernet link state.
4116 - CONFIG_NS16550_MIN_FUNCTIONS:
4117 Define this if you desire to only have use of the NS16550_init
4118 and NS16550_putc functions for the serial driver located at
4119 drivers/serial/ns16550.c. This option is useful for saving
4120 space for already greatly restricted images, including but not
4121 limited to NAND_SPL configurations.
4123 - CONFIG_DISPLAY_BOARDINFO
4124 Display information about the board that U-Boot is running on
4125 when U-Boot starts up. The board function checkboard() is called
4128 - CONFIG_DISPLAY_BOARDINFO_LATE
4129 Similar to the previous option, but display this information
4130 later, once stdio is running and output goes to the LCD, if
4133 Low Level (hardware related) configuration options:
4134 ---------------------------------------------------
4136 - CONFIG_SYS_CACHELINE_SIZE:
4137 Cache Line Size of the CPU.
4139 - CONFIG_SYS_DEFAULT_IMMR:
4140 Default address of the IMMR after system reset.
4142 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4143 and RPXsuper) to be able to adjust the position of
4144 the IMMR register after a reset.
4146 - CONFIG_SYS_CCSRBAR_DEFAULT:
4147 Default (power-on reset) physical address of CCSR on Freescale
4150 - CONFIG_SYS_CCSRBAR:
4151 Virtual address of CCSR. On a 32-bit build, this is typically
4152 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4154 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4155 for cross-platform code that uses that macro instead.
4157 - CONFIG_SYS_CCSRBAR_PHYS:
4158 Physical address of CCSR. CCSR can be relocated to a new
4159 physical address, if desired. In this case, this macro should
4160 be set to that address. Otherwise, it should be set to the
4161 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4162 is typically relocated on 36-bit builds. It is recommended
4163 that this macro be defined via the _HIGH and _LOW macros:
4165 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4166 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4168 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4169 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4170 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4171 used in assembly code, so it must not contain typecasts or
4172 integer size suffixes (e.g. "ULL").
4174 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4175 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4176 used in assembly code, so it must not contain typecasts or
4177 integer size suffixes (e.g. "ULL").
4179 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4180 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4181 forced to a value that ensures that CCSR is not relocated.
4183 - Floppy Disk Support:
4184 CONFIG_SYS_FDC_DRIVE_NUMBER
4186 the default drive number (default value 0)
4188 CONFIG_SYS_ISA_IO_STRIDE
4190 defines the spacing between FDC chipset registers
4193 CONFIG_SYS_ISA_IO_OFFSET
4195 defines the offset of register from address. It
4196 depends on which part of the data bus is connected to
4197 the FDC chipset. (default value 0)
4199 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4200 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4203 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4204 fdc_hw_init() is called at the beginning of the FDC
4205 setup. fdc_hw_init() must be provided by the board
4206 source code. It is used to make hardware dependant
4210 Most IDE controllers were designed to be connected with PCI
4211 interface. Only few of them were designed for AHB interface.
4212 When software is doing ATA command and data transfer to
4213 IDE devices through IDE-AHB controller, some additional
4214 registers accessing to these kind of IDE-AHB controller
4217 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4218 DO NOT CHANGE unless you know exactly what you're
4219 doing! (11-4) [MPC8xx/82xx systems only]
4221 - CONFIG_SYS_INIT_RAM_ADDR:
4223 Start address of memory area that can be used for
4224 initial data and stack; please note that this must be
4225 writable memory that is working WITHOUT special
4226 initialization, i. e. you CANNOT use normal RAM which
4227 will become available only after programming the
4228 memory controller and running certain initialization
4231 U-Boot uses the following memory types:
4232 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4233 - MPC824X: data cache
4234 - PPC4xx: data cache
4236 - CONFIG_SYS_GBL_DATA_OFFSET:
4238 Offset of the initial data structure in the memory
4239 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4240 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4241 data is located at the end of the available space
4242 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4243 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4244 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4245 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4248 On the MPC824X (or other systems that use the data
4249 cache for initial memory) the address chosen for
4250 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4251 point to an otherwise UNUSED address space between
4252 the top of RAM and the start of the PCI space.
4254 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4256 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4258 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4260 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4262 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4264 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4266 - CONFIG_SYS_OR_TIMING_SDRAM:
4269 - CONFIG_SYS_MAMR_PTA:
4270 periodic timer for refresh
4272 - CONFIG_SYS_DER: Debug Event Register (37-47)
4274 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4275 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4276 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4277 CONFIG_SYS_BR1_PRELIM:
4278 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4280 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4281 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4282 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4283 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4285 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4286 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4287 Machine Mode Register and Memory Periodic Timer
4288 Prescaler definitions (SDRAM timing)
4290 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4291 enable I2C microcode relocation patch (MPC8xx);
4292 define relocation offset in DPRAM [DSP2]
4294 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4295 enable SMC microcode relocation patch (MPC8xx);
4296 define relocation offset in DPRAM [SMC1]
4298 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4299 enable SPI microcode relocation patch (MPC8xx);
4300 define relocation offset in DPRAM [SCC4]
4302 - CONFIG_SYS_USE_OSCCLK:
4303 Use OSCM clock mode on MBX8xx board. Be careful,
4304 wrong setting might damage your board. Read
4305 doc/README.MBX before setting this variable!
4307 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4308 Offset of the bootmode word in DPRAM used by post
4309 (Power On Self Tests). This definition overrides
4310 #define'd default value in commproc.h resp.
4313 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4314 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4315 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4316 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4317 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4318 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4319 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4320 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4321 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4323 - CONFIG_PCI_DISABLE_PCIE:
4324 Disable PCI-Express on systems where it is supported but not
4327 - CONFIG_PCI_ENUM_ONLY
4328 Only scan through and get the devices on the busses.
4329 Don't do any setup work, presumably because someone or
4330 something has already done it, and we don't need to do it
4331 a second time. Useful for platforms that are pre-booted
4332 by coreboot or similar.
4334 - CONFIG_PCI_INDIRECT_BRIDGE:
4335 Enable support for indirect PCI bridges.
4338 Chip has SRIO or not
4341 Board has SRIO 1 port available
4344 Board has SRIO 2 port available
4346 - CONFIG_SRIO_PCIE_BOOT_MASTER
4347 Board can support master function for Boot from SRIO and PCIE
4349 - CONFIG_SYS_SRIOn_MEM_VIRT:
4350 Virtual Address of SRIO port 'n' memory region
4352 - CONFIG_SYS_SRIOn_MEM_PHYS:
4353 Physical Address of SRIO port 'n' memory region
4355 - CONFIG_SYS_SRIOn_MEM_SIZE:
4356 Size of SRIO port 'n' memory region
4358 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4359 Defined to tell the NAND controller that the NAND chip is using
4361 Not all NAND drivers use this symbol.
4362 Example of drivers that use it:
4363 - drivers/mtd/nand/ndfc.c
4364 - drivers/mtd/nand/mxc_nand.c
4366 - CONFIG_SYS_NDFC_EBC0_CFG
4367 Sets the EBC0_CFG register for the NDFC. If not defined
4368 a default value will be used.
4371 Get DDR timing information from an I2C EEPROM. Common
4372 with pluggable memory modules such as SODIMMs
4375 I2C address of the SPD EEPROM
4377 - CONFIG_SYS_SPD_BUS_NUM
4378 If SPD EEPROM is on an I2C bus other than the first
4379 one, specify here. Note that the value must resolve
4380 to something your driver can deal with.
4382 - CONFIG_SYS_DDR_RAW_TIMING
4383 Get DDR timing information from other than SPD. Common with
4384 soldered DDR chips onboard without SPD. DDR raw timing
4385 parameters are extracted from datasheet and hard-coded into
4386 header files or board specific files.
4388 - CONFIG_FSL_DDR_INTERACTIVE
4389 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4391 - CONFIG_SYS_83XX_DDR_USES_CS0
4392 Only for 83xx systems. If specified, then DDR should
4393 be configured using CS0 and CS1 instead of CS2 and CS3.
4395 - CONFIG_ETHER_ON_FEC[12]
4396 Define to enable FEC[12] on a 8xx series processor.
4398 - CONFIG_FEC[12]_PHY
4399 Define to the hardcoded PHY address which corresponds
4400 to the given FEC; i. e.
4401 #define CONFIG_FEC1_PHY 4
4402 means that the PHY with address 4 is connected to FEC1
4404 When set to -1, means to probe for first available.
4406 - CONFIG_FEC[12]_PHY_NORXERR
4407 The PHY does not have a RXERR line (RMII only).
4408 (so program the FEC to ignore it).
4411 Enable RMII mode for all FECs.
4412 Note that this is a global option, we can't
4413 have one FEC in standard MII mode and another in RMII mode.
4415 - CONFIG_CRC32_VERIFY
4416 Add a verify option to the crc32 command.
4419 => crc32 -v <address> <count> <crc32>
4421 Where address/count indicate a memory area
4422 and crc32 is the correct crc32 which the
4426 Add the "loopw" memory command. This only takes effect if
4427 the memory commands are activated globally (CONFIG_CMD_MEM).
4430 Add the "mdc" and "mwc" memory commands. These are cyclic
4435 This command will print 4 bytes (10,11,12,13) each 500 ms.
4437 => mwc.l 100 12345678 10
4438 This command will write 12345678 to address 100 all 10 ms.
4440 This only takes effect if the memory commands are activated
4441 globally (CONFIG_CMD_MEM).
4443 - CONFIG_SKIP_LOWLEVEL_INIT
4444 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4445 low level initializations (like setting up the memory
4446 controller) are omitted and/or U-Boot does not
4447 relocate itself into RAM.
4449 Normally this variable MUST NOT be defined. The only
4450 exception is when U-Boot is loaded (to RAM) by some
4451 other boot loader or by a debugger which performs
4452 these initializations itself.
4455 Modifies the behaviour of start.S when compiling a loader
4456 that is executed before the actual U-Boot. E.g. when
4457 compiling a NAND SPL.
4460 Modifies the behaviour of start.S when compiling a loader
4461 that is executed after the SPL and before the actual U-Boot.
4462 It is loaded by the SPL.
4464 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4465 Only for 85xx systems. If this variable is specified, the section
4466 .resetvec is not kept and the section .bootpg is placed in the
4467 previous 4k of the .text section.
4469 - CONFIG_ARCH_MAP_SYSMEM
4470 Generally U-Boot (and in particular the md command) uses
4471 effective address. It is therefore not necessary to regard
4472 U-Boot address as virtual addresses that need to be translated
4473 to physical addresses. However, sandbox requires this, since
4474 it maintains its own little RAM buffer which contains all
4475 addressable memory. This option causes some memory accesses
4476 to be mapped through map_sysmem() / unmap_sysmem().
4478 - CONFIG_USE_ARCH_MEMCPY
4479 CONFIG_USE_ARCH_MEMSET
4480 If these options are used a optimized version of memcpy/memset will
4481 be used if available. These functions may be faster under some
4482 conditions but may increase the binary size.
4484 - CONFIG_X86_RESET_VECTOR
4485 If defined, the x86 reset vector code is included. This is not
4486 needed when U-Boot is running from Coreboot.
4489 Defines the MPU clock speed (in MHz).
4491 NOTE : currently only supported on AM335x platforms.
4493 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4494 Enables the RTC32K OSC on AM33xx based plattforms
4496 Freescale QE/FMAN Firmware Support:
4497 -----------------------------------
4499 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4500 loading of "firmware", which is encoded in the QE firmware binary format.
4501 This firmware often needs to be loaded during U-Boot booting, so macros
4502 are used to identify the storage device (NOR flash, SPI, etc) and the address
4505 - CONFIG_SYS_QE_FMAN_FW_ADDR
4506 The address in the storage device where the firmware is located. The
4507 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4510 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4511 The maximum possible size of the firmware. The firmware binary format
4512 has a field that specifies the actual size of the firmware, but it
4513 might not be possible to read any part of the firmware unless some
4514 local storage is allocated to hold the entire firmware first.
4516 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4517 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4518 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4519 virtual address in NOR flash.
4521 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4522 Specifies that QE/FMAN firmware is located in NAND flash.
4523 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4525 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4526 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4527 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4529 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4530 Specifies that QE/FMAN firmware is located on the primary SPI
4531 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4533 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4534 Specifies that QE/FMAN firmware is located in the remote (master)
4535 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4536 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4537 window->master inbound window->master LAW->the ucode address in
4538 master's memory space.
4540 Building the Software:
4541 ======================
4543 Building U-Boot has been tested in several native build environments
4544 and in many different cross environments. Of course we cannot support
4545 all possibly existing versions of cross development tools in all
4546 (potentially obsolete) versions. In case of tool chain problems we
4547 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4548 which is extensively used to build and test U-Boot.
4550 If you are not using a native environment, it is assumed that you
4551 have GNU cross compiling tools available in your path. In this case,
4552 you must set the environment variable CROSS_COMPILE in your shell.
4553 Note that no changes to the Makefile or any other source files are
4554 necessary. For example using the ELDK on a 4xx CPU, please enter:
4556 $ CROSS_COMPILE=ppc_4xx-
4557 $ export CROSS_COMPILE
4559 Note: If you wish to generate Windows versions of the utilities in
4560 the tools directory you can use the MinGW toolchain
4561 (http://www.mingw.org). Set your HOST tools to the MinGW
4562 toolchain and execute 'make tools'. For example:
4564 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4566 Binaries such as tools/mkimage.exe will be created which can
4567 be executed on computers running Windows.
4569 U-Boot is intended to be simple to build. After installing the
4570 sources you must configure U-Boot for one specific board type. This
4575 where "NAME_config" is the name of one of the existing configu-
4576 rations; see boards.cfg for supported names.
4578 Note: for some board special configuration names may exist; check if
4579 additional information is available from the board vendor; for
4580 instance, the TQM823L systems are available without (standard)
4581 or with LCD support. You can select such additional "features"
4582 when choosing the configuration, i. e.
4585 - will configure for a plain TQM823L, i. e. no LCD support
4587 make TQM823L_LCD_config
4588 - will configure for a TQM823L with U-Boot console on LCD
4593 Finally, type "make all", and you should get some working U-Boot
4594 images ready for download to / installation on your system:
4596 - "u-boot.bin" is a raw binary image
4597 - "u-boot" is an image in ELF binary format
4598 - "u-boot.srec" is in Motorola S-Record format
4600 By default the build is performed locally and the objects are saved
4601 in the source directory. One of the two methods can be used to change
4602 this behavior and build U-Boot to some external directory:
4604 1. Add O= to the make command line invocations:
4606 make O=/tmp/build distclean
4607 make O=/tmp/build NAME_config
4608 make O=/tmp/build all
4610 2. Set environment variable BUILD_DIR to point to the desired location:
4612 export BUILD_DIR=/tmp/build
4617 Note that the command line "O=" setting overrides the BUILD_DIR environment
4621 Please be aware that the Makefiles assume you are using GNU make, so
4622 for instance on NetBSD you might need to use "gmake" instead of
4626 If the system board that you have is not listed, then you will need
4627 to port U-Boot to your hardware platform. To do this, follow these
4630 1. Add a new configuration option for your board to the toplevel
4631 "boards.cfg" file, using the existing entries as examples.
4632 Follow the instructions there to keep the boards in order.
4633 2. Create a new directory to hold your board specific code. Add any
4634 files you need. In your board directory, you will need at least
4635 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4636 3. Create a new configuration file "include/configs/<board>.h" for
4638 3. If you're porting U-Boot to a new CPU, then also create a new
4639 directory to hold your CPU specific code. Add any files you need.
4640 4. Run "make <board>_config" with your new name.
4641 5. Type "make", and you should get a working "u-boot.srec" file
4642 to be installed on your target system.
4643 6. Debug and solve any problems that might arise.
4644 [Of course, this last step is much harder than it sounds.]
4647 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4648 ==============================================================
4650 If you have modified U-Boot sources (for instance added a new board
4651 or support for new devices, a new CPU, etc.) you are expected to
4652 provide feedback to the other developers. The feedback normally takes
4653 the form of a "patch", i. e. a context diff against a certain (latest
4654 official or latest in the git repository) version of U-Boot sources.
4656 But before you submit such a patch, please verify that your modifi-
4657 cation did not break existing code. At least make sure that *ALL* of
4658 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4659 just run the "MAKEALL" script, which will configure and build U-Boot
4660 for ALL supported system. Be warned, this will take a while. You can
4661 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4662 environment variable to the script, i. e. to use the ELDK cross tools
4665 CROSS_COMPILE=ppc_8xx- MAKEALL
4667 or to build on a native PowerPC system you can type
4669 CROSS_COMPILE=' ' MAKEALL
4671 When using the MAKEALL script, the default behaviour is to build
4672 U-Boot in the source directory. This location can be changed by
4673 setting the BUILD_DIR environment variable. Also, for each target
4674 built, the MAKEALL script saves two log files (<target>.ERR and
4675 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4676 location can be changed by setting the MAKEALL_LOGDIR environment
4677 variable. For example:
4679 export BUILD_DIR=/tmp/build
4680 export MAKEALL_LOGDIR=/tmp/log
4681 CROSS_COMPILE=ppc_8xx- MAKEALL
4683 With the above settings build objects are saved in the /tmp/build,
4684 log files are saved in the /tmp/log and the source tree remains clean
4685 during the whole build process.
4688 See also "U-Boot Porting Guide" below.
4691 Monitor Commands - Overview:
4692 ============================
4694 go - start application at address 'addr'
4695 run - run commands in an environment variable
4696 bootm - boot application image from memory
4697 bootp - boot image via network using BootP/TFTP protocol
4698 bootz - boot zImage from memory
4699 tftpboot- boot image via network using TFTP protocol
4700 and env variables "ipaddr" and "serverip"
4701 (and eventually "gatewayip")
4702 tftpput - upload a file via network using TFTP protocol
4703 rarpboot- boot image via network using RARP/TFTP protocol
4704 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4705 loads - load S-Record file over serial line
4706 loadb - load binary file over serial line (kermit mode)
4708 mm - memory modify (auto-incrementing)
4709 nm - memory modify (constant address)
4710 mw - memory write (fill)
4712 cmp - memory compare
4713 crc32 - checksum calculation
4714 i2c - I2C sub-system
4715 sspi - SPI utility commands
4716 base - print or set address offset
4717 printenv- print environment variables
4718 setenv - set environment variables
4719 saveenv - save environment variables to persistent storage
4720 protect - enable or disable FLASH write protection
4721 erase - erase FLASH memory
4722 flinfo - print FLASH memory information
4723 nand - NAND memory operations (see doc/README.nand)
4724 bdinfo - print Board Info structure
4725 iminfo - print header information for application image
4726 coninfo - print console devices and informations
4727 ide - IDE sub-system
4728 loop - infinite loop on address range
4729 loopw - infinite write loop on address range
4730 mtest - simple RAM test
4731 icache - enable or disable instruction cache
4732 dcache - enable or disable data cache
4733 reset - Perform RESET of the CPU
4734 echo - echo args to console
4735 version - print monitor version
4736 help - print online help
4737 ? - alias for 'help'
4740 Monitor Commands - Detailed Description:
4741 ========================================
4745 For now: just type "help <command>".
4748 Environment Variables:
4749 ======================
4751 U-Boot supports user configuration using Environment Variables which
4752 can be made persistent by saving to Flash memory.
4754 Environment Variables are set using "setenv", printed using
4755 "printenv", and saved to Flash using "saveenv". Using "setenv"
4756 without a value can be used to delete a variable from the
4757 environment. As long as you don't save the environment you are
4758 working with an in-memory copy. In case the Flash area containing the
4759 environment is erased by accident, a default environment is provided.
4761 Some configuration options can be set using Environment Variables.
4763 List of environment variables (most likely not complete):
4765 baudrate - see CONFIG_BAUDRATE
4767 bootdelay - see CONFIG_BOOTDELAY
4769 bootcmd - see CONFIG_BOOTCOMMAND
4771 bootargs - Boot arguments when booting an RTOS image
4773 bootfile - Name of the image to load with TFTP
4775 bootm_low - Memory range available for image processing in the bootm
4776 command can be restricted. This variable is given as
4777 a hexadecimal number and defines lowest address allowed
4778 for use by the bootm command. See also "bootm_size"
4779 environment variable. Address defined by "bootm_low" is
4780 also the base of the initial memory mapping for the Linux
4781 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4784 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4785 This variable is given as a hexadecimal number and it
4786 defines the size of the memory region starting at base
4787 address bootm_low that is accessible by the Linux kernel
4788 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4789 as the default value if it is defined, and bootm_size is
4792 bootm_size - Memory range available for image processing in the bootm
4793 command can be restricted. This variable is given as
4794 a hexadecimal number and defines the size of the region
4795 allowed for use by the bootm command. See also "bootm_low"
4796 environment variable.
4798 updatefile - Location of the software update file on a TFTP server, used
4799 by the automatic software update feature. Please refer to
4800 documentation in doc/README.update for more details.
4802 autoload - if set to "no" (any string beginning with 'n'),
4803 "bootp" will just load perform a lookup of the
4804 configuration from the BOOTP server, but not try to
4805 load any image using TFTP
4807 autostart - if set to "yes", an image loaded using the "bootp",
4808 "rarpboot", "tftpboot" or "diskboot" commands will
4809 be automatically started (by internally calling
4812 If set to "no", a standalone image passed to the
4813 "bootm" command will be copied to the load address
4814 (and eventually uncompressed), but NOT be started.
4815 This can be used to load and uncompress arbitrary
4818 fdt_high - if set this restricts the maximum address that the
4819 flattened device tree will be copied into upon boot.
4820 For example, if you have a system with 1 GB memory
4821 at physical address 0x10000000, while Linux kernel
4822 only recognizes the first 704 MB as low memory, you
4823 may need to set fdt_high as 0x3C000000 to have the
4824 device tree blob be copied to the maximum address
4825 of the 704 MB low memory, so that Linux kernel can
4826 access it during the boot procedure.
4828 If this is set to the special value 0xFFFFFFFF then
4829 the fdt will not be copied at all on boot. For this
4830 to work it must reside in writable memory, have
4831 sufficient padding on the end of it for u-boot to
4832 add the information it needs into it, and the memory
4833 must be accessible by the kernel.
4835 fdtcontroladdr- if set this is the address of the control flattened
4836 device tree used by U-Boot when CONFIG_OF_CONTROL is
4839 i2cfast - (PPC405GP|PPC405EP only)
4840 if set to 'y' configures Linux I2C driver for fast
4841 mode (400kHZ). This environment variable is used in
4842 initialization code. So, for changes to be effective
4843 it must be saved and board must be reset.
4845 initrd_high - restrict positioning of initrd images:
4846 If this variable is not set, initrd images will be
4847 copied to the highest possible address in RAM; this
4848 is usually what you want since it allows for
4849 maximum initrd size. If for some reason you want to
4850 make sure that the initrd image is loaded below the
4851 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4852 variable to a value of "no" or "off" or "0".
4853 Alternatively, you can set it to a maximum upper
4854 address to use (U-Boot will still check that it
4855 does not overwrite the U-Boot stack and data).
4857 For instance, when you have a system with 16 MB
4858 RAM, and want to reserve 4 MB from use by Linux,
4859 you can do this by adding "mem=12M" to the value of
4860 the "bootargs" variable. However, now you must make
4861 sure that the initrd image is placed in the first
4862 12 MB as well - this can be done with
4864 setenv initrd_high 00c00000
4866 If you set initrd_high to 0xFFFFFFFF, this is an
4867 indication to U-Boot that all addresses are legal
4868 for the Linux kernel, including addresses in flash
4869 memory. In this case U-Boot will NOT COPY the
4870 ramdisk at all. This may be useful to reduce the
4871 boot time on your system, but requires that this
4872 feature is supported by your Linux kernel.
4874 ipaddr - IP address; needed for tftpboot command
4876 loadaddr - Default load address for commands like "bootp",
4877 "rarpboot", "tftpboot", "loadb" or "diskboot"
4879 loads_echo - see CONFIG_LOADS_ECHO
4881 serverip - TFTP server IP address; needed for tftpboot command
4883 bootretry - see CONFIG_BOOT_RETRY_TIME
4885 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4887 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4889 ethprime - controls which interface is used first.
4891 ethact - controls which interface is currently active.
4892 For example you can do the following
4894 => setenv ethact FEC
4895 => ping 192.168.0.1 # traffic sent on FEC
4896 => setenv ethact SCC
4897 => ping 10.0.0.1 # traffic sent on SCC
4899 ethrotate - When set to "no" U-Boot does not go through all
4900 available network interfaces.
4901 It just stays at the currently selected interface.
4903 netretry - When set to "no" each network operation will
4904 either succeed or fail without retrying.
4905 When set to "once" the network operation will
4906 fail when all the available network interfaces
4907 are tried once without success.
4908 Useful on scripts which control the retry operation
4911 npe_ucode - set load address for the NPE microcode
4913 silent_linux - If set then linux will be told to boot silently, by
4914 changing the console to be empty. If "yes" it will be
4915 made silent. If "no" it will not be made silent. If
4916 unset, then it will be made silent if the U-Boot console
4919 tftpsrcport - If this is set, the value is used for TFTP's
4922 tftpdstport - If this is set, the value is used for TFTP's UDP
4923 destination port instead of the Well Know Port 69.
4925 tftpblocksize - Block size to use for TFTP transfers; if not set,
4926 we use the TFTP server's default block size
4928 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4929 seconds, minimum value is 1000 = 1 second). Defines
4930 when a packet is considered to be lost so it has to
4931 be retransmitted. The default is 5000 = 5 seconds.
4932 Lowering this value may make downloads succeed
4933 faster in networks with high packet loss rates or
4934 with unreliable TFTP servers.
4936 vlan - When set to a value < 4095 the traffic over
4937 Ethernet is encapsulated/received over 802.1q
4940 The following image location variables contain the location of images
4941 used in booting. The "Image" column gives the role of the image and is
4942 not an environment variable name. The other columns are environment
4943 variable names. "File Name" gives the name of the file on a TFTP
4944 server, "RAM Address" gives the location in RAM the image will be
4945 loaded to, and "Flash Location" gives the image's address in NOR
4946 flash or offset in NAND flash.
4948 *Note* - these variables don't have to be defined for all boards, some
4949 boards currenlty use other variables for these purposes, and some
4950 boards use these variables for other purposes.
4952 Image File Name RAM Address Flash Location
4953 ----- --------- ----------- --------------
4954 u-boot u-boot u-boot_addr_r u-boot_addr
4955 Linux kernel bootfile kernel_addr_r kernel_addr
4956 device tree blob fdtfile fdt_addr_r fdt_addr
4957 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4959 The following environment variables may be used and automatically
4960 updated by the network boot commands ("bootp" and "rarpboot"),
4961 depending the information provided by your boot server:
4963 bootfile - see above
4964 dnsip - IP address of your Domain Name Server
4965 dnsip2 - IP address of your secondary Domain Name Server
4966 gatewayip - IP address of the Gateway (Router) to use
4967 hostname - Target hostname
4969 netmask - Subnet Mask
4970 rootpath - Pathname of the root filesystem on the NFS server
4971 serverip - see above
4974 There are two special Environment Variables:
4976 serial# - contains hardware identification information such
4977 as type string and/or serial number
4978 ethaddr - Ethernet address
4980 These variables can be set only once (usually during manufacturing of
4981 the board). U-Boot refuses to delete or overwrite these variables
4982 once they have been set once.
4985 Further special Environment Variables:
4987 ver - Contains the U-Boot version string as printed
4988 with the "version" command. This variable is
4989 readonly (see CONFIG_VERSION_VARIABLE).
4992 Please note that changes to some configuration parameters may take
4993 only effect after the next boot (yes, that's just like Windoze :-).
4996 Callback functions for environment variables:
4997 ---------------------------------------------
4999 For some environment variables, the behavior of u-boot needs to change
5000 when their values are changed. This functionailty allows functions to
5001 be associated with arbitrary variables. On creation, overwrite, or
5002 deletion, the callback will provide the opportunity for some side
5003 effect to happen or for the change to be rejected.
5005 The callbacks are named and associated with a function using the
5006 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5008 These callbacks are associated with variables in one of two ways. The
5009 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5010 in the board configuration to a string that defines a list of
5011 associations. The list must be in the following format:
5013 entry = variable_name[:callback_name]
5016 If the callback name is not specified, then the callback is deleted.
5017 Spaces are also allowed anywhere in the list.
5019 Callbacks can also be associated by defining the ".callbacks" variable
5020 with the same list format above. Any association in ".callbacks" will
5021 override any association in the static list. You can define
5022 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5023 ".callbacks" envirnoment variable in the default or embedded environment.
5026 Command Line Parsing:
5027 =====================
5029 There are two different command line parsers available with U-Boot:
5030 the old "simple" one, and the much more powerful "hush" shell:
5032 Old, simple command line parser:
5033 --------------------------------
5035 - supports environment variables (through setenv / saveenv commands)
5036 - several commands on one line, separated by ';'
5037 - variable substitution using "... ${name} ..." syntax
5038 - special characters ('$', ';') can be escaped by prefixing with '\',
5040 setenv bootcmd bootm \${address}
5041 - You can also escape text by enclosing in single apostrophes, for example:
5042 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5047 - similar to Bourne shell, with control structures like
5048 if...then...else...fi, for...do...done; while...do...done,
5049 until...do...done, ...
5050 - supports environment ("global") variables (through setenv / saveenv
5051 commands) and local shell variables (through standard shell syntax
5052 "name=value"); only environment variables can be used with "run"
5058 (1) If a command line (or an environment variable executed by a "run"
5059 command) contains several commands separated by semicolon, and
5060 one of these commands fails, then the remaining commands will be
5063 (2) If you execute several variables with one call to run (i. e.
5064 calling run with a list of variables as arguments), any failing
5065 command will cause "run" to terminate, i. e. the remaining
5066 variables are not executed.
5068 Note for Redundant Ethernet Interfaces:
5069 =======================================
5071 Some boards come with redundant Ethernet interfaces; U-Boot supports
5072 such configurations and is capable of automatic selection of a
5073 "working" interface when needed. MAC assignment works as follows:
5075 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5076 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5077 "eth1addr" (=>eth1), "eth2addr", ...
5079 If the network interface stores some valid MAC address (for instance
5080 in SROM), this is used as default address if there is NO correspon-
5081 ding setting in the environment; if the corresponding environment
5082 variable is set, this overrides the settings in the card; that means:
5084 o If the SROM has a valid MAC address, and there is no address in the
5085 environment, the SROM's address is used.
5087 o If there is no valid address in the SROM, and a definition in the
5088 environment exists, then the value from the environment variable is
5091 o If both the SROM and the environment contain a MAC address, and
5092 both addresses are the same, this MAC address is used.
5094 o If both the SROM and the environment contain a MAC address, and the
5095 addresses differ, the value from the environment is used and a
5098 o If neither SROM nor the environment contain a MAC address, an error
5101 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5102 will be programmed into hardware as part of the initialization process. This
5103 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5104 The naming convention is as follows:
5105 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5110 U-Boot is capable of booting (and performing other auxiliary operations on)
5111 images in two formats:
5113 New uImage format (FIT)
5114 -----------------------
5116 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5117 to Flattened Device Tree). It allows the use of images with multiple
5118 components (several kernels, ramdisks, etc.), with contents protected by
5119 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5125 Old image format is based on binary files which can be basically anything,
5126 preceded by a special header; see the definitions in include/image.h for
5127 details; basically, the header defines the following image properties:
5129 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5130 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5131 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5132 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5134 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5135 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5136 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5137 * Compression Type (uncompressed, gzip, bzip2)
5143 The header is marked by a special Magic Number, and both the header
5144 and the data portions of the image are secured against corruption by
5151 Although U-Boot should support any OS or standalone application
5152 easily, the main focus has always been on Linux during the design of
5155 U-Boot includes many features that so far have been part of some
5156 special "boot loader" code within the Linux kernel. Also, any
5157 "initrd" images to be used are no longer part of one big Linux image;
5158 instead, kernel and "initrd" are separate images. This implementation
5159 serves several purposes:
5161 - the same features can be used for other OS or standalone
5162 applications (for instance: using compressed images to reduce the
5163 Flash memory footprint)
5165 - it becomes much easier to port new Linux kernel versions because
5166 lots of low-level, hardware dependent stuff are done by U-Boot
5168 - the same Linux kernel image can now be used with different "initrd"
5169 images; of course this also means that different kernel images can
5170 be run with the same "initrd". This makes testing easier (you don't
5171 have to build a new "zImage.initrd" Linux image when you just
5172 change a file in your "initrd"). Also, a field-upgrade of the
5173 software is easier now.
5179 Porting Linux to U-Boot based systems:
5180 ---------------------------------------
5182 U-Boot cannot save you from doing all the necessary modifications to
5183 configure the Linux device drivers for use with your target hardware
5184 (no, we don't intend to provide a full virtual machine interface to
5187 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5189 Just make sure your machine specific header file (for instance
5190 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5191 Information structure as we define in include/asm-<arch>/u-boot.h,
5192 and make sure that your definition of IMAP_ADDR uses the same value
5193 as your U-Boot configuration in CONFIG_SYS_IMMR.
5196 Configuring the Linux kernel:
5197 -----------------------------
5199 No specific requirements for U-Boot. Make sure you have some root
5200 device (initial ramdisk, NFS) for your target system.
5203 Building a Linux Image:
5204 -----------------------
5206 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5207 not used. If you use recent kernel source, a new build target
5208 "uImage" will exist which automatically builds an image usable by
5209 U-Boot. Most older kernels also have support for a "pImage" target,
5210 which was introduced for our predecessor project PPCBoot and uses a
5211 100% compatible format.
5220 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5221 encapsulate a compressed Linux kernel image with header information,
5222 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5224 * build a standard "vmlinux" kernel image (in ELF binary format):
5226 * convert the kernel into a raw binary image:
5228 ${CROSS_COMPILE}-objcopy -O binary \
5229 -R .note -R .comment \
5230 -S vmlinux linux.bin
5232 * compress the binary image:
5236 * package compressed binary image for U-Boot:
5238 mkimage -A ppc -O linux -T kernel -C gzip \
5239 -a 0 -e 0 -n "Linux Kernel Image" \
5240 -d linux.bin.gz uImage
5243 The "mkimage" tool can also be used to create ramdisk images for use
5244 with U-Boot, either separated from the Linux kernel image, or
5245 combined into one file. "mkimage" encapsulates the images with a 64
5246 byte header containing information about target architecture,
5247 operating system, image type, compression method, entry points, time
5248 stamp, CRC32 checksums, etc.
5250 "mkimage" can be called in two ways: to verify existing images and
5251 print the header information, or to build new images.
5253 In the first form (with "-l" option) mkimage lists the information
5254 contained in the header of an existing U-Boot image; this includes
5255 checksum verification:
5257 tools/mkimage -l image
5258 -l ==> list image header information
5260 The second form (with "-d" option) is used to build a U-Boot image
5261 from a "data file" which is used as image payload:
5263 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5264 -n name -d data_file image
5265 -A ==> set architecture to 'arch'
5266 -O ==> set operating system to 'os'
5267 -T ==> set image type to 'type'
5268 -C ==> set compression type 'comp'
5269 -a ==> set load address to 'addr' (hex)
5270 -e ==> set entry point to 'ep' (hex)
5271 -n ==> set image name to 'name'
5272 -d ==> use image data from 'datafile'
5274 Right now, all Linux kernels for PowerPC systems use the same load
5275 address (0x00000000), but the entry point address depends on the
5278 - 2.2.x kernels have the entry point at 0x0000000C,
5279 - 2.3.x and later kernels have the entry point at 0x00000000.
5281 So a typical call to build a U-Boot image would read:
5283 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5284 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5285 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5286 > examples/uImage.TQM850L
5287 Image Name: 2.4.4 kernel for TQM850L
5288 Created: Wed Jul 19 02:34:59 2000
5289 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5290 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5291 Load Address: 0x00000000
5292 Entry Point: 0x00000000
5294 To verify the contents of the image (or check for corruption):
5296 -> tools/mkimage -l examples/uImage.TQM850L
5297 Image Name: 2.4.4 kernel for TQM850L
5298 Created: Wed Jul 19 02:34:59 2000
5299 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5300 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5301 Load Address: 0x00000000
5302 Entry Point: 0x00000000
5304 NOTE: for embedded systems where boot time is critical you can trade
5305 speed for memory and install an UNCOMPRESSED image instead: this
5306 needs more space in Flash, but boots much faster since it does not
5307 need to be uncompressed:
5309 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5310 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5311 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5312 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5313 > examples/uImage.TQM850L-uncompressed
5314 Image Name: 2.4.4 kernel for TQM850L
5315 Created: Wed Jul 19 02:34:59 2000
5316 Image Type: PowerPC Linux Kernel Image (uncompressed)
5317 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5318 Load Address: 0x00000000
5319 Entry Point: 0x00000000
5322 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5323 when your kernel is intended to use an initial ramdisk:
5325 -> tools/mkimage -n 'Simple Ramdisk Image' \
5326 > -A ppc -O linux -T ramdisk -C gzip \
5327 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5328 Image Name: Simple Ramdisk Image
5329 Created: Wed Jan 12 14:01:50 2000
5330 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5331 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5332 Load Address: 0x00000000
5333 Entry Point: 0x00000000
5335 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5336 option performs the converse operation of the mkimage's second form (the "-d"
5337 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5340 tools/dumpimage -i image -p position data_file
5341 -i ==> extract from the 'image' a specific 'data_file', \
5342 indexed by 'position'
5345 Installing a Linux Image:
5346 -------------------------
5348 To downloading a U-Boot image over the serial (console) interface,
5349 you must convert the image to S-Record format:
5351 objcopy -I binary -O srec examples/image examples/image.srec
5353 The 'objcopy' does not understand the information in the U-Boot
5354 image header, so the resulting S-Record file will be relative to
5355 address 0x00000000. To load it to a given address, you need to
5356 specify the target address as 'offset' parameter with the 'loads'
5359 Example: install the image to address 0x40100000 (which on the
5360 TQM8xxL is in the first Flash bank):
5362 => erase 40100000 401FFFFF
5368 ## Ready for S-Record download ...
5369 ~>examples/image.srec
5370 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5372 15989 15990 15991 15992
5373 [file transfer complete]
5375 ## Start Addr = 0x00000000
5378 You can check the success of the download using the 'iminfo' command;
5379 this includes a checksum verification so you can be sure no data
5380 corruption happened:
5384 ## Checking Image at 40100000 ...
5385 Image Name: 2.2.13 for initrd on TQM850L
5386 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5387 Data Size: 335725 Bytes = 327 kB = 0 MB
5388 Load Address: 00000000
5389 Entry Point: 0000000c
5390 Verifying Checksum ... OK
5396 The "bootm" command is used to boot an application that is stored in
5397 memory (RAM or Flash). In case of a Linux kernel image, the contents
5398 of the "bootargs" environment variable is passed to the kernel as
5399 parameters. You can check and modify this variable using the
5400 "printenv" and "setenv" commands:
5403 => printenv bootargs
5404 bootargs=root=/dev/ram
5406 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5408 => printenv bootargs
5409 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5412 ## Booting Linux kernel at 40020000 ...
5413 Image Name: 2.2.13 for NFS on TQM850L
5414 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5415 Data Size: 381681 Bytes = 372 kB = 0 MB
5416 Load Address: 00000000
5417 Entry Point: 0000000c
5418 Verifying Checksum ... OK
5419 Uncompressing Kernel Image ... OK
5420 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
5421 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5422 time_init: decrementer frequency = 187500000/60
5423 Calibrating delay loop... 49.77 BogoMIPS
5424 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5427 If you want to boot a Linux kernel with initial RAM disk, you pass
5428 the memory addresses of both the kernel and the initrd image (PPBCOOT
5429 format!) to the "bootm" command:
5431 => imi 40100000 40200000
5433 ## Checking Image at 40100000 ...
5434 Image Name: 2.2.13 for initrd on TQM850L
5435 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5436 Data Size: 335725 Bytes = 327 kB = 0 MB
5437 Load Address: 00000000
5438 Entry Point: 0000000c
5439 Verifying Checksum ... OK
5441 ## Checking Image at 40200000 ...
5442 Image Name: Simple Ramdisk Image
5443 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5444 Data Size: 566530 Bytes = 553 kB = 0 MB
5445 Load Address: 00000000
5446 Entry Point: 00000000
5447 Verifying Checksum ... OK
5449 => bootm 40100000 40200000
5450 ## Booting Linux kernel at 40100000 ...
5451 Image Name: 2.2.13 for initrd on TQM850L
5452 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5453 Data Size: 335725 Bytes = 327 kB = 0 MB
5454 Load Address: 00000000
5455 Entry Point: 0000000c
5456 Verifying Checksum ... OK
5457 Uncompressing Kernel Image ... OK
5458 ## Loading RAMDisk Image at 40200000 ...
5459 Image Name: Simple Ramdisk Image
5460 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5461 Data Size: 566530 Bytes = 553 kB = 0 MB
5462 Load Address: 00000000
5463 Entry Point: 00000000
5464 Verifying Checksum ... OK
5465 Loading Ramdisk ... OK
5466 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
5467 Boot arguments: root=/dev/ram
5468 time_init: decrementer frequency = 187500000/60
5469 Calibrating delay loop... 49.77 BogoMIPS
5471 RAMDISK: Compressed image found at block 0
5472 VFS: Mounted root (ext2 filesystem).
5476 Boot Linux and pass a flat device tree:
5479 First, U-Boot must be compiled with the appropriate defines. See the section
5480 titled "Linux Kernel Interface" above for a more in depth explanation. The
5481 following is an example of how to start a kernel and pass an updated
5487 oft=oftrees/mpc8540ads.dtb
5488 => tftp $oftaddr $oft
5489 Speed: 1000, full duplex
5491 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5492 Filename 'oftrees/mpc8540ads.dtb'.
5493 Load address: 0x300000
5496 Bytes transferred = 4106 (100a hex)
5497 => tftp $loadaddr $bootfile
5498 Speed: 1000, full duplex
5500 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5502 Load address: 0x200000
5503 Loading:############
5505 Bytes transferred = 1029407 (fb51f hex)
5510 => bootm $loadaddr - $oftaddr
5511 ## Booting image at 00200000 ...
5512 Image Name: Linux-2.6.17-dirty
5513 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5514 Data Size: 1029343 Bytes = 1005.2 kB
5515 Load Address: 00000000
5516 Entry Point: 00000000
5517 Verifying Checksum ... OK
5518 Uncompressing Kernel Image ... OK
5519 Booting using flat device tree at 0x300000
5520 Using MPC85xx ADS machine description
5521 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5525 More About U-Boot Image Types:
5526 ------------------------------
5528 U-Boot supports the following image types:
5530 "Standalone Programs" are directly runnable in the environment
5531 provided by U-Boot; it is expected that (if they behave
5532 well) you can continue to work in U-Boot after return from
5533 the Standalone Program.
5534 "OS Kernel Images" are usually images of some Embedded OS which
5535 will take over control completely. Usually these programs
5536 will install their own set of exception handlers, device
5537 drivers, set up the MMU, etc. - this means, that you cannot
5538 expect to re-enter U-Boot except by resetting the CPU.
5539 "RAMDisk Images" are more or less just data blocks, and their
5540 parameters (address, size) are passed to an OS kernel that is
5542 "Multi-File Images" contain several images, typically an OS
5543 (Linux) kernel image and one or more data images like
5544 RAMDisks. This construct is useful for instance when you want
5545 to boot over the network using BOOTP etc., where the boot
5546 server provides just a single image file, but you want to get
5547 for instance an OS kernel and a RAMDisk image.
5549 "Multi-File Images" start with a list of image sizes, each
5550 image size (in bytes) specified by an "uint32_t" in network
5551 byte order. This list is terminated by an "(uint32_t)0".
5552 Immediately after the terminating 0 follow the images, one by
5553 one, all aligned on "uint32_t" boundaries (size rounded up to
5554 a multiple of 4 bytes).
5556 "Firmware Images" are binary images containing firmware (like
5557 U-Boot or FPGA images) which usually will be programmed to
5560 "Script files" are command sequences that will be executed by
5561 U-Boot's command interpreter; this feature is especially
5562 useful when you configure U-Boot to use a real shell (hush)
5563 as command interpreter.
5565 Booting the Linux zImage:
5566 -------------------------
5568 On some platforms, it's possible to boot Linux zImage. This is done
5569 using the "bootz" command. The syntax of "bootz" command is the same
5570 as the syntax of "bootm" command.
5572 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5573 kernel with raw initrd images. The syntax is slightly different, the
5574 address of the initrd must be augmented by it's size, in the following
5575 format: "<initrd addres>:<initrd size>".
5581 One of the features of U-Boot is that you can dynamically load and
5582 run "standalone" applications, which can use some resources of
5583 U-Boot like console I/O functions or interrupt services.
5585 Two simple examples are included with the sources:
5590 'examples/hello_world.c' contains a small "Hello World" Demo
5591 application; it is automatically compiled when you build U-Boot.
5592 It's configured to run at address 0x00040004, so you can play with it
5596 ## Ready for S-Record download ...
5597 ~>examples/hello_world.srec
5598 1 2 3 4 5 6 7 8 9 10 11 ...
5599 [file transfer complete]
5601 ## Start Addr = 0x00040004
5603 => go 40004 Hello World! This is a test.
5604 ## Starting application at 0x00040004 ...
5615 Hit any key to exit ...
5617 ## Application terminated, rc = 0x0
5619 Another example, which demonstrates how to register a CPM interrupt
5620 handler with the U-Boot code, can be found in 'examples/timer.c'.
5621 Here, a CPM timer is set up to generate an interrupt every second.
5622 The interrupt service routine is trivial, just printing a '.'
5623 character, but this is just a demo program. The application can be
5624 controlled by the following keys:
5626 ? - print current values og the CPM Timer registers
5627 b - enable interrupts and start timer
5628 e - stop timer and disable interrupts
5629 q - quit application
5632 ## Ready for S-Record download ...
5633 ~>examples/timer.srec
5634 1 2 3 4 5 6 7 8 9 10 11 ...
5635 [file transfer complete]
5637 ## Start Addr = 0x00040004
5640 ## Starting application at 0x00040004 ...
5643 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5646 [q, b, e, ?] Set interval 1000000 us
5649 [q, b, e, ?] ........
5650 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5653 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5656 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5659 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5661 [q, b, e, ?] ...Stopping timer
5663 [q, b, e, ?] ## Application terminated, rc = 0x0
5669 Over time, many people have reported problems when trying to use the
5670 "minicom" terminal emulation program for serial download. I (wd)
5671 consider minicom to be broken, and recommend not to use it. Under
5672 Unix, I recommend to use C-Kermit for general purpose use (and
5673 especially for kermit binary protocol download ("loadb" command), and
5674 use "cu" for S-Record download ("loads" command). See
5675 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5676 for help with kermit.
5679 Nevertheless, if you absolutely want to use it try adding this
5680 configuration to your "File transfer protocols" section:
5682 Name Program Name U/D FullScr IO-Red. Multi
5683 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5684 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5690 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5691 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5693 Building requires a cross environment; it is known to work on
5694 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5695 need gmake since the Makefiles are not compatible with BSD make).
5696 Note that the cross-powerpc package does not install include files;
5697 attempting to build U-Boot will fail because <machine/ansi.h> is
5698 missing. This file has to be installed and patched manually:
5700 # cd /usr/pkg/cross/powerpc-netbsd/include
5702 # ln -s powerpc machine
5703 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5704 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5706 Native builds *don't* work due to incompatibilities between native
5707 and U-Boot include files.
5709 Booting assumes that (the first part of) the image booted is a
5710 stage-2 loader which in turn loads and then invokes the kernel
5711 proper. Loader sources will eventually appear in the NetBSD source
5712 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5713 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5716 Implementation Internals:
5717 =========================
5719 The following is not intended to be a complete description of every
5720 implementation detail. However, it should help to understand the
5721 inner workings of U-Boot and make it easier to port it to custom
5725 Initial Stack, Global Data:
5726 ---------------------------
5728 The implementation of U-Boot is complicated by the fact that U-Boot
5729 starts running out of ROM (flash memory), usually without access to
5730 system RAM (because the memory controller is not initialized yet).
5731 This means that we don't have writable Data or BSS segments, and BSS
5732 is not initialized as zero. To be able to get a C environment working
5733 at all, we have to allocate at least a minimal stack. Implementation
5734 options for this are defined and restricted by the CPU used: Some CPU
5735 models provide on-chip memory (like the IMMR area on MPC8xx and
5736 MPC826x processors), on others (parts of) the data cache can be
5737 locked as (mis-) used as memory, etc.
5739 Chris Hallinan posted a good summary of these issues to the
5740 U-Boot mailing list:
5742 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5743 From: "Chris Hallinan" <clh@net1plus.com>
5744 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5747 Correct me if I'm wrong, folks, but the way I understand it
5748 is this: Using DCACHE as initial RAM for Stack, etc, does not
5749 require any physical RAM backing up the cache. The cleverness
5750 is that the cache is being used as a temporary supply of
5751 necessary storage before the SDRAM controller is setup. It's
5752 beyond the scope of this list to explain the details, but you
5753 can see how this works by studying the cache architecture and
5754 operation in the architecture and processor-specific manuals.
5756 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5757 is another option for the system designer to use as an
5758 initial stack/RAM area prior to SDRAM being available. Either
5759 option should work for you. Using CS 4 should be fine if your
5760 board designers haven't used it for something that would
5761 cause you grief during the initial boot! It is frequently not
5764 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5765 with your processor/board/system design. The default value
5766 you will find in any recent u-boot distribution in
5767 walnut.h should work for you. I'd set it to a value larger
5768 than your SDRAM module. If you have a 64MB SDRAM module, set
5769 it above 400_0000. Just make sure your board has no resources
5770 that are supposed to respond to that address! That code in
5771 start.S has been around a while and should work as is when
5772 you get the config right.
5777 It is essential to remember this, since it has some impact on the C
5778 code for the initialization procedures:
5780 * Initialized global data (data segment) is read-only. Do not attempt
5783 * Do not use any uninitialized global data (or implicitely initialized
5784 as zero data - BSS segment) at all - this is undefined, initiali-
5785 zation is performed later (when relocating to RAM).
5787 * Stack space is very limited. Avoid big data buffers or things like
5790 Having only the stack as writable memory limits means we cannot use
5791 normal global data to share information beween the code. But it
5792 turned out that the implementation of U-Boot can be greatly
5793 simplified by making a global data structure (gd_t) available to all
5794 functions. We could pass a pointer to this data as argument to _all_
5795 functions, but this would bloat the code. Instead we use a feature of
5796 the GCC compiler (Global Register Variables) to share the data: we
5797 place a pointer (gd) to the global data into a register which we
5798 reserve for this purpose.
5800 When choosing a register for such a purpose we are restricted by the
5801 relevant (E)ABI specifications for the current architecture, and by
5802 GCC's implementation.
5804 For PowerPC, the following registers have specific use:
5806 R2: reserved for system use
5807 R3-R4: parameter passing and return values
5808 R5-R10: parameter passing
5809 R13: small data area pointer
5813 (U-Boot also uses R12 as internal GOT pointer. r12
5814 is a volatile register so r12 needs to be reset when
5815 going back and forth between asm and C)
5817 ==> U-Boot will use R2 to hold a pointer to the global data
5819 Note: on PPC, we could use a static initializer (since the
5820 address of the global data structure is known at compile time),
5821 but it turned out that reserving a register results in somewhat
5822 smaller code - although the code savings are not that big (on
5823 average for all boards 752 bytes for the whole U-Boot image,
5824 624 text + 127 data).
5826 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5827 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5829 ==> U-Boot will use P3 to hold a pointer to the global data
5831 On ARM, the following registers are used:
5833 R0: function argument word/integer result
5834 R1-R3: function argument word
5835 R9: platform specific
5836 R10: stack limit (used only if stack checking is enabled)
5837 R11: argument (frame) pointer
5838 R12: temporary workspace
5841 R15: program counter
5843 ==> U-Boot will use R9 to hold a pointer to the global data
5845 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5847 On Nios II, the ABI is documented here:
5848 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5850 ==> U-Boot will use gp to hold a pointer to the global data
5852 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5853 to access small data sections, so gp is free.
5855 On NDS32, the following registers are used:
5857 R0-R1: argument/return
5859 R15: temporary register for assembler
5860 R16: trampoline register
5861 R28: frame pointer (FP)
5862 R29: global pointer (GP)
5863 R30: link register (LP)
5864 R31: stack pointer (SP)
5865 PC: program counter (PC)
5867 ==> U-Boot will use R10 to hold a pointer to the global data
5869 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5870 or current versions of GCC may "optimize" the code too much.
5875 U-Boot runs in system state and uses physical addresses, i.e. the
5876 MMU is not used either for address mapping nor for memory protection.
5878 The available memory is mapped to fixed addresses using the memory
5879 controller. In this process, a contiguous block is formed for each
5880 memory type (Flash, SDRAM, SRAM), even when it consists of several
5881 physical memory banks.
5883 U-Boot is installed in the first 128 kB of the first Flash bank (on
5884 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5885 booting and sizing and initializing DRAM, the code relocates itself
5886 to the upper end of DRAM. Immediately below the U-Boot code some
5887 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5888 configuration setting]. Below that, a structure with global Board
5889 Info data is placed, followed by the stack (growing downward).
5891 Additionally, some exception handler code is copied to the low 8 kB
5892 of DRAM (0x00000000 ... 0x00001FFF).
5894 So a typical memory configuration with 16 MB of DRAM could look like
5897 0x0000 0000 Exception Vector code
5900 0x0000 2000 Free for Application Use
5906 0x00FB FF20 Monitor Stack (Growing downward)
5907 0x00FB FFAC Board Info Data and permanent copy of global data
5908 0x00FC 0000 Malloc Arena
5911 0x00FE 0000 RAM Copy of Monitor Code
5912 ... eventually: LCD or video framebuffer
5913 ... eventually: pRAM (Protected RAM - unchanged by reset)
5914 0x00FF FFFF [End of RAM]
5917 System Initialization:
5918 ----------------------
5920 In the reset configuration, U-Boot starts at the reset entry point
5921 (on most PowerPC systems at address 0x00000100). Because of the reset
5922 configuration for CS0# this is a mirror of the onboard Flash memory.
5923 To be able to re-map memory U-Boot then jumps to its link address.
5924 To be able to implement the initialization code in C, a (small!)
5925 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5926 which provide such a feature like MPC8xx or MPC8260), or in a locked
5927 part of the data cache. After that, U-Boot initializes the CPU core,
5928 the caches and the SIU.
5930 Next, all (potentially) available memory banks are mapped using a
5931 preliminary mapping. For example, we put them on 512 MB boundaries
5932 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5933 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5934 programmed for SDRAM access. Using the temporary configuration, a
5935 simple memory test is run that determines the size of the SDRAM
5938 When there is more than one SDRAM bank, and the banks are of
5939 different size, the largest is mapped first. For equal size, the first
5940 bank (CS2#) is mapped first. The first mapping is always for address
5941 0x00000000, with any additional banks following immediately to create
5942 contiguous memory starting from 0.
5944 Then, the monitor installs itself at the upper end of the SDRAM area
5945 and allocates memory for use by malloc() and for the global Board
5946 Info data; also, the exception vector code is copied to the low RAM
5947 pages, and the final stack is set up.
5949 Only after this relocation will you have a "normal" C environment;
5950 until that you are restricted in several ways, mostly because you are
5951 running from ROM, and because the code will have to be relocated to a
5955 U-Boot Porting Guide:
5956 ----------------------
5958 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5962 int main(int argc, char *argv[])
5964 sighandler_t no_more_time;
5966 signal(SIGALRM, no_more_time);
5967 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5969 if (available_money > available_manpower) {
5970 Pay consultant to port U-Boot;
5974 Download latest U-Boot source;
5976 Subscribe to u-boot mailing list;
5979 email("Hi, I am new to U-Boot, how do I get started?");
5982 Read the README file in the top level directory;
5983 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5984 Read applicable doc/*.README;
5985 Read the source, Luke;
5986 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5989 if (available_money > toLocalCurrency ($2500))
5992 Add a lot of aggravation and time;
5994 if (a similar board exists) { /* hopefully... */
5995 cp -a board/<similar> board/<myboard>
5996 cp include/configs/<similar>.h include/configs/<myboard>.h
5998 Create your own board support subdirectory;
5999 Create your own board include/configs/<myboard>.h file;
6001 Edit new board/<myboard> files
6002 Edit new include/configs/<myboard>.h
6007 Add / modify source code;
6011 email("Hi, I am having problems...");
6013 Send patch file to the U-Boot email list;
6014 if (reasonable critiques)
6015 Incorporate improvements from email list code review;
6017 Defend code as written;
6023 void no_more_time (int sig)
6032 All contributions to U-Boot should conform to the Linux kernel
6033 coding style; see the file "Documentation/CodingStyle" and the script
6034 "scripts/Lindent" in your Linux kernel source directory.
6036 Source files originating from a different project (for example the
6037 MTD subsystem) are generally exempt from these guidelines and are not
6038 reformated to ease subsequent migration to newer versions of those
6041 Please note that U-Boot is implemented in C (and to some small parts in
6042 Assembler); no C++ is used, so please do not use C++ style comments (//)
6045 Please also stick to the following formatting rules:
6046 - remove any trailing white space
6047 - use TAB characters for indentation and vertical alignment, not spaces
6048 - make sure NOT to use DOS '\r\n' line feeds
6049 - do not add more than 2 consecutive empty lines to source files
6050 - do not add trailing empty lines to source files
6052 Submissions which do not conform to the standards may be returned
6053 with a request to reformat the changes.
6059 Since the number of patches for U-Boot is growing, we need to
6060 establish some rules. Submissions which do not conform to these rules
6061 may be rejected, even when they contain important and valuable stuff.
6063 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6065 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6066 see http://lists.denx.de/mailman/listinfo/u-boot
6068 When you send a patch, please include the following information with
6071 * For bug fixes: a description of the bug and how your patch fixes
6072 this bug. Please try to include a way of demonstrating that the
6073 patch actually fixes something.
6075 * For new features: a description of the feature and your
6078 * A CHANGELOG entry as plaintext (separate from the patch)
6080 * For major contributions, your entry to the CREDITS file
6082 * When you add support for a new board, don't forget to add a
6083 maintainer e-mail address to the boards.cfg file, too.
6085 * If your patch adds new configuration options, don't forget to
6086 document these in the README file.
6088 * The patch itself. If you are using git (which is *strongly*
6089 recommended) you can easily generate the patch using the
6090 "git format-patch". If you then use "git send-email" to send it to
6091 the U-Boot mailing list, you will avoid most of the common problems
6092 with some other mail clients.
6094 If you cannot use git, use "diff -purN OLD NEW". If your version of
6095 diff does not support these options, then get the latest version of
6098 The current directory when running this command shall be the parent
6099 directory of the U-Boot source tree (i. e. please make sure that
6100 your patch includes sufficient directory information for the
6103 We prefer patches as plain text. MIME attachments are discouraged,
6104 and compressed attachments must not be used.
6106 * If one logical set of modifications affects or creates several
6107 files, all these changes shall be submitted in a SINGLE patch file.
6109 * Changesets that contain different, unrelated modifications shall be
6110 submitted as SEPARATE patches, one patch per changeset.
6115 * Before sending the patch, run the MAKEALL script on your patched
6116 source tree and make sure that no errors or warnings are reported
6117 for any of the boards.
6119 * Keep your modifications to the necessary minimum: A patch
6120 containing several unrelated changes or arbitrary reformats will be
6121 returned with a request to re-formatting / split it.
6123 * If you modify existing code, make sure that your new code does not
6124 add to the memory footprint of the code ;-) Small is beautiful!
6125 When adding new features, these should compile conditionally only
6126 (using #ifdef), and the resulting code with the new feature
6127 disabled must not need more memory than the old code without your
6130 * Remember that there is a size limit of 100 kB per message on the
6131 u-boot mailing list. Bigger patches will be moderated. If they are
6132 reasonable and not too big, they will be acknowledged. But patches
6133 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob