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.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Board flavour: (if CONFIG_MPC8260ADS is defined)
327 CONFIG_SYS_8260ADS - original MPC8260ADS
328 CONFIG_SYS_8266ADS - MPC8266ADS
329 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
330 CONFIG_SYS_8272ADS - MPC8272ADS
332 - Marvell Family Member
333 CONFIG_SYS_MVFS - define it if you want to enable
334 multiple fs option at one time
335 for marvell soc family
337 - MPC824X Family Member (if CONFIG_MPC824X is defined)
338 Define exactly one of
339 CONFIG_MPC8240, CONFIG_MPC8245
341 - 8xx CPU Options: (if using an MPC8xx CPU)
342 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
343 get_gclk_freq() cannot work
344 e.g. if there is no 32KHz
345 reference PIT/RTC clock
346 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
349 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
350 CONFIG_SYS_8xx_CPUCLK_MIN
351 CONFIG_SYS_8xx_CPUCLK_MAX
352 CONFIG_8xx_CPUCLK_DEFAULT
353 See doc/README.MPC866
355 CONFIG_SYS_MEASURE_CPUCLK
357 Define this to measure the actual CPU clock instead
358 of relying on the correctness of the configured
359 values. Mostly useful for board bringup to make sure
360 the PLL is locked at the intended frequency. Note
361 that this requires a (stable) reference clock (32 kHz
362 RTC clock or CONFIG_SYS_8XX_XIN)
364 CONFIG_SYS_DELAYED_ICACHE
366 Define this option if you want to enable the
367 ICache only when Code runs from RAM.
372 Specifies that the core is a 64-bit PowerPC implementation (implements
373 the "64" category of the Power ISA). This is necessary for ePAPR
374 compliance, among other possible reasons.
376 CONFIG_SYS_FSL_TBCLK_DIV
378 Defines the core time base clock divider ratio compared to the
379 system clock. On most PQ3 devices this is 8, on newer QorIQ
380 devices it can be 16 or 32. The ratio varies from SoC to Soc.
382 CONFIG_SYS_FSL_PCIE_COMPAT
384 Defines the string to utilize when trying to match PCIe device
385 tree nodes for the given platform.
387 CONFIG_SYS_PPC_E500_DEBUG_TLB
389 Enables a temporary TLB entry to be used during boot to work
390 around limitations in e500v1 and e500v2 external debugger
391 support. This reduces the portions of the boot code where
392 breakpoints and single stepping do not work. The value of this
393 symbol should be set to the TLB1 entry to be used for this
396 CONFIG_SYS_FSL_ERRATUM_A004510
398 Enables a workaround for erratum A004510. If set,
399 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
400 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
402 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
405 Defines one or two SoC revisions (low 8 bits of SVR)
406 for which the A004510 workaround should be applied.
408 The rest of SVR is either not relevant to the decision
409 of whether the erratum is present (e.g. p2040 versus
410 p2041) or is implied by the build target, which controls
411 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
413 See Freescale App Note 4493 for more information about
416 CONFIG_A003399_NOR_WORKAROUND
417 Enables a workaround for IFC erratum A003399. It is only
418 requred during NOR boot.
420 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
422 This is the value to write into CCSR offset 0x18600
423 according to the A004510 workaround.
425 CONFIG_SYS_FSL_DSP_DDR_ADDR
426 This value denotes start offset of DDR memory which is
427 connected exclusively to the DSP cores.
429 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
430 This value denotes start offset of M2 memory
431 which is directly connected to the DSP core.
433 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
434 This value denotes start offset of M3 memory which is directly
435 connected to the DSP core.
437 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
438 This value denotes start offset of DSP CCSR space.
440 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
441 Single Source Clock is clocking mode present in some of FSL SoC's.
442 In this mode, a single differential clock is used to supply
443 clocks to the sysclock, ddrclock and usbclock.
445 CONFIG_SYS_CPC_REINIT_F
446 This CONFIG is defined when the CPC is configured as SRAM at the
447 time of U-boot entry and is required to be re-initialized.
450 Inidcates this SoC supports deep sleep feature. If deep sleep is
451 supported, core will start to execute uboot when wakes up.
453 - Generic CPU options:
454 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
456 Defines the endianess of the CPU. Implementation of those
457 values is arch specific.
460 Freescale DDR driver in use. This type of DDR controller is
461 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
464 CONFIG_SYS_FSL_DDR_ADDR
465 Freescale DDR memory-mapped register base.
467 CONFIG_SYS_FSL_DDR_EMU
468 Specify emulator support for DDR. Some DDR features such as
469 deskew training are not available.
471 CONFIG_SYS_FSL_DDRC_GEN1
472 Freescale DDR1 controller.
474 CONFIG_SYS_FSL_DDRC_GEN2
475 Freescale DDR2 controller.
477 CONFIG_SYS_FSL_DDRC_GEN3
478 Freescale DDR3 controller.
480 CONFIG_SYS_FSL_DDRC_GEN4
481 Freescale DDR4 controller.
483 CONFIG_SYS_FSL_DDRC_ARM_GEN3
484 Freescale DDR3 controller for ARM-based SoCs.
487 Board config to use DDR1. It can be enabled for SoCs with
488 Freescale DDR1 or DDR2 controllers, depending on the board
492 Board config to use DDR2. It can be eanbeld for SoCs with
493 Freescale DDR2 or DDR3 controllers, depending on the board
497 Board config to use DDR3. It can be enabled for SoCs with
498 Freescale DDR3 or DDR3L controllers.
501 Board config to use DDR3L. It can be enabled for SoCs with
505 Board config to use DDR4. It can be enabled for SoCs with
508 CONFIG_SYS_FSL_IFC_BE
509 Defines the IFC controller register space as Big Endian
511 CONFIG_SYS_FSL_IFC_LE
512 Defines the IFC controller register space as Little Endian
514 CONFIG_SYS_FSL_PBL_PBI
515 It enables addition of RCW (Power on reset configuration) in built image.
516 Please refer doc/README.pblimage for more details
518 CONFIG_SYS_FSL_PBL_RCW
519 It adds PBI(pre-boot instructions) commands in u-boot build image.
520 PBI commands can be used to configure SoC before it starts the execution.
521 Please refer doc/README.pblimage for more details
524 It adds a target to create boot binary having SPL binary in PBI format
525 concatenated with u-boot binary.
527 CONFIG_SYS_FSL_DDR_BE
528 Defines the DDR controller register space as Big Endian
530 CONFIG_SYS_FSL_DDR_LE
531 Defines the DDR controller register space as Little Endian
533 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
534 Physical address from the view of DDR controllers. It is the
535 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
536 it could be different for ARM SoCs.
538 CONFIG_SYS_FSL_DDR_INTLV_256B
539 DDR controller interleaving on 256-byte. This is a special
540 interleaving mode, handled by Dickens for Freescale layerscape
543 - Intel Monahans options:
544 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
546 Defines the Monahans run mode to oscillator
547 ratio. Valid values are 8, 16, 24, 31. The core
548 frequency is this value multiplied by 13 MHz.
550 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
552 Defines the Monahans turbo mode to oscillator
553 ratio. Valid values are 1 (default if undefined) and
554 2. The core frequency as calculated above is multiplied
558 CONFIG_SYS_INIT_SP_OFFSET
560 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
561 pointer. This is needed for the temporary stack before
564 CONFIG_SYS_MIPS_CACHE_MODE
566 Cache operation mode for the MIPS CPU.
567 See also arch/mips/include/asm/mipsregs.h.
569 CONF_CM_CACHABLE_NO_WA
572 CONF_CM_CACHABLE_NONCOHERENT
576 CONF_CM_CACHABLE_ACCELERATED
578 CONFIG_SYS_XWAY_EBU_BOOTCFG
580 Special option for Lantiq XWAY SoCs for booting from NOR flash.
581 See also arch/mips/cpu/mips32/start.S.
583 CONFIG_XWAY_SWAP_BYTES
585 Enable compilation of tools/xway-swap-bytes needed for Lantiq
586 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
587 be swapped if a flash programmer is used.
590 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
592 Select high exception vectors of the ARM core, e.g., do not
593 clear the V bit of the c1 register of CP15.
595 CONFIG_SYS_THUMB_BUILD
597 Use this flag to build U-Boot using the Thumb instruction
598 set for ARM architectures. Thumb instruction set provides
599 better code density. For ARM architectures that support
600 Thumb2 this flag will result in Thumb2 code generated by
603 CONFIG_ARM_ERRATA_716044
604 CONFIG_ARM_ERRATA_742230
605 CONFIG_ARM_ERRATA_743622
606 CONFIG_ARM_ERRATA_751472
607 CONFIG_ARM_ERRATA_794072
608 CONFIG_ARM_ERRATA_761320
610 If set, the workarounds for these ARM errata are applied early
611 during U-Boot startup. Note that these options force the
612 workarounds to be applied; no CPU-type/version detection
613 exists, unlike the similar options in the Linux kernel. Do not
614 set these options unless they apply!
619 The frequency of the timer returned by get_timer().
620 get_timer() must operate in milliseconds and this CONFIG
621 option must be set to 1000.
623 - Linux Kernel Interface:
626 U-Boot stores all clock information in Hz
627 internally. For binary compatibility with older Linux
628 kernels (which expect the clocks passed in the
629 bd_info data to be in MHz) the environment variable
630 "clocks_in_mhz" can be defined so that U-Boot
631 converts clock data to MHZ before passing it to the
633 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
634 "clocks_in_mhz=1" is automatically included in the
637 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
639 When transferring memsize parameter to linux, some versions
640 expect it to be in bytes, others in MB.
641 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
645 New kernel versions are expecting firmware settings to be
646 passed using flattened device trees (based on open firmware
650 * New libfdt-based support
651 * Adds the "fdt" command
652 * The bootm command automatically updates the fdt
654 OF_CPU - The proper name of the cpus node (only required for
655 MPC512X and MPC5xxx based boards).
656 OF_SOC - The proper name of the soc node (only required for
657 MPC512X and MPC5xxx based boards).
658 OF_TBCLK - The timebase frequency.
659 OF_STDOUT_PATH - The path to the console device
661 boards with QUICC Engines require OF_QE to set UCC MAC
664 CONFIG_OF_BOARD_SETUP
666 Board code has addition modification that it wants to make
667 to the flat device tree before handing it off to the kernel
671 This define fills in the correct boot CPU in the boot
672 param header, the default value is zero if undefined.
676 U-Boot can detect if an IDE device is present or not.
677 If not, and this new config option is activated, U-Boot
678 removes the ATA node from the DTS before booting Linux,
679 so the Linux IDE driver does not probe the device and
680 crash. This is needed for buggy hardware (uc101) where
681 no pull down resistor is connected to the signal IDE5V_DD7.
683 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
685 This setting is mandatory for all boards that have only one
686 machine type and must be used to specify the machine type
687 number as it appears in the ARM machine registry
688 (see http://www.arm.linux.org.uk/developer/machines/).
689 Only boards that have multiple machine types supported
690 in a single configuration file and the machine type is
691 runtime discoverable, do not have to use this setting.
693 - vxWorks boot parameters:
695 bootvx constructs a valid bootline using the following
696 environments variables: bootfile, ipaddr, serverip, hostname.
697 It loads the vxWorks image pointed bootfile.
699 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
700 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
701 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
702 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
704 CONFIG_SYS_VXWORKS_ADD_PARAMS
706 Add it at the end of the bootline. E.g "u=username pw=secret"
708 Note: If a "bootargs" environment is defined, it will overwride
709 the defaults discussed just above.
711 - Cache Configuration:
712 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
713 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
714 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
716 - Cache Configuration for ARM:
717 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
719 CONFIG_SYS_PL310_BASE - Physical base address of PL310
720 controller register space
725 Define this if you want support for Amba PrimeCell PL010 UARTs.
729 Define this if you want support for Amba PrimeCell PL011 UARTs.
733 If you have Amba PrimeCell PL011 UARTs, set this variable to
734 the clock speed of the UARTs.
738 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
739 define this to a list of base addresses for each (supported)
740 port. See e.g. include/configs/versatile.h
742 CONFIG_PL011_SERIAL_RLCR
744 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
745 have separate receive and transmit line control registers. Set
746 this variable to initialize the extra register.
748 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
750 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
751 boot loader that has already initialized the UART. Define this
752 variable to flush the UART at init time.
756 Depending on board, define exactly one serial port
757 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
758 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
759 console by defining CONFIG_8xx_CONS_NONE
761 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
762 port routines must be defined elsewhere
763 (i.e. serial_init(), serial_getc(), ...)
766 Enables console device for a color framebuffer. Needs following
767 defines (cf. smiLynxEM, i8042)
768 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
770 VIDEO_HW_RECTFILL graphic chip supports
773 VIDEO_HW_BITBLT graphic chip supports
774 bit-blit (cf. smiLynxEM)
775 VIDEO_VISIBLE_COLS visible pixel columns
777 VIDEO_VISIBLE_ROWS visible pixel rows
778 VIDEO_PIXEL_SIZE bytes per pixel
779 VIDEO_DATA_FORMAT graphic data format
780 (0-5, cf. cfb_console.c)
781 VIDEO_FB_ADRS framebuffer address
782 VIDEO_KBD_INIT_FCT keyboard int fct
783 (i.e. i8042_kbd_init())
784 VIDEO_TSTC_FCT test char fct
786 VIDEO_GETC_FCT get char fct
788 CONFIG_CONSOLE_CURSOR cursor drawing on/off
789 (requires blink timer
791 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
792 CONFIG_CONSOLE_TIME display time/date info in
794 (requires CONFIG_CMD_DATE)
795 CONFIG_VIDEO_LOGO display Linux logo in
797 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
798 linux_logo.h for logo.
799 Requires CONFIG_VIDEO_LOGO
800 CONFIG_CONSOLE_EXTRA_INFO
801 additional board info beside
804 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
805 a limited number of ANSI escape sequences (cursor control,
806 erase functions and limited graphics rendition control).
808 When CONFIG_CFB_CONSOLE is defined, video console is
809 default i/o. Serial console can be forced with
810 environment 'console=serial'.
812 When CONFIG_SILENT_CONSOLE is defined, all console
813 messages (by U-Boot and Linux!) can be silenced with
814 the "silent" environment variable. See
815 doc/README.silent for more information.
817 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
819 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
823 CONFIG_BAUDRATE - in bps
824 Select one of the baudrates listed in
825 CONFIG_SYS_BAUDRATE_TABLE, see below.
826 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
828 - Console Rx buffer length
829 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
830 the maximum receive buffer length for the SMC.
831 This option is actual only for 82xx and 8xx possible.
832 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
833 must be defined, to setup the maximum idle timeout for
836 - Pre-Console Buffer:
837 Prior to the console being initialised (i.e. serial UART
838 initialised etc) all console output is silently discarded.
839 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
840 buffer any console messages prior to the console being
841 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
842 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
843 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
844 bytes are output before the console is initialised, the
845 earlier bytes are discarded.
847 'Sane' compilers will generate smaller code if
848 CONFIG_PRE_CON_BUF_SZ is a power of 2
850 - Safe printf() functions
851 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
852 the printf() functions. These are defined in
853 include/vsprintf.h and include snprintf(), vsnprintf() and
854 so on. Code size increase is approximately 300-500 bytes.
855 If this option is not given then these functions will
856 silently discard their buffer size argument - this means
857 you are not getting any overflow checking in this case.
859 - Boot Delay: CONFIG_BOOTDELAY - in seconds
860 Delay before automatically booting the default image;
861 set to -1 to disable autoboot.
862 set to -2 to autoboot with no delay and not check for abort
863 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
865 See doc/README.autoboot for these options that
866 work with CONFIG_BOOTDELAY. None are required.
867 CONFIG_BOOT_RETRY_TIME
868 CONFIG_BOOT_RETRY_MIN
869 CONFIG_AUTOBOOT_KEYED
870 CONFIG_AUTOBOOT_PROMPT
871 CONFIG_AUTOBOOT_DELAY_STR
872 CONFIG_AUTOBOOT_STOP_STR
873 CONFIG_AUTOBOOT_DELAY_STR2
874 CONFIG_AUTOBOOT_STOP_STR2
875 CONFIG_ZERO_BOOTDELAY_CHECK
876 CONFIG_RESET_TO_RETRY
880 Only needed when CONFIG_BOOTDELAY is enabled;
881 define a command string that is automatically executed
882 when no character is read on the console interface
883 within "Boot Delay" after reset.
886 This can be used to pass arguments to the bootm
887 command. The value of CONFIG_BOOTARGS goes into the
888 environment value "bootargs".
890 CONFIG_RAMBOOT and CONFIG_NFSBOOT
891 The value of these goes into the environment as
892 "ramboot" and "nfsboot" respectively, and can be used
893 as a convenience, when switching between booting from
897 CONFIG_BOOTCOUNT_LIMIT
898 Implements a mechanism for detecting a repeating reboot
900 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
903 If no softreset save registers are found on the hardware
904 "bootcount" is stored in the environment. To prevent a
905 saveenv on all reboots, the environment variable
906 "upgrade_available" is used. If "upgrade_available" is
907 0, "bootcount" is always 0, if "upgrade_available" is
908 1 "bootcount" is incremented in the environment.
909 So the Userspace Applikation must set the "upgrade_available"
910 and "bootcount" variable to 0, if a boot was successfully.
915 When this option is #defined, the existence of the
916 environment variable "preboot" will be checked
917 immediately before starting the CONFIG_BOOTDELAY
918 countdown and/or running the auto-boot command resp.
919 entering interactive mode.
921 This feature is especially useful when "preboot" is
922 automatically generated or modified. For an example
923 see the LWMON board specific code: here "preboot" is
924 modified when the user holds down a certain
925 combination of keys on the (special) keyboard when
928 - Serial Download Echo Mode:
930 If defined to 1, all characters received during a
931 serial download (using the "loads" command) are
932 echoed back. This might be needed by some terminal
933 emulations (like "cu"), but may as well just take
934 time on others. This setting #define's the initial
935 value of the "loads_echo" environment variable.
937 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
939 Select one of the baudrates listed in
940 CONFIG_SYS_BAUDRATE_TABLE, see below.
943 Monitor commands can be included or excluded
944 from the build by using the #include files
945 <config_cmd_all.h> and #undef'ing unwanted
946 commands, or using <config_cmd_default.h>
947 and augmenting with additional #define's
950 The default command configuration includes all commands
951 except those marked below with a "*".
953 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
954 CONFIG_CMD_ASKENV * ask for env variable
955 CONFIG_CMD_BDI bdinfo
956 CONFIG_CMD_BEDBUG * Include BedBug Debugger
957 CONFIG_CMD_BMP * BMP support
958 CONFIG_CMD_BSP * Board specific commands
959 CONFIG_CMD_BOOTD bootd
960 CONFIG_CMD_CACHE * icache, dcache
961 CONFIG_CMD_CLK * clock command support
962 CONFIG_CMD_CONSOLE coninfo
963 CONFIG_CMD_CRC32 * crc32
964 CONFIG_CMD_DATE * support for RTC, date/time...
965 CONFIG_CMD_DHCP * DHCP support
966 CONFIG_CMD_DIAG * Diagnostics
967 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
968 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
969 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
970 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
971 CONFIG_CMD_DTT * Digital Therm and Thermostat
972 CONFIG_CMD_ECHO echo arguments
973 CONFIG_CMD_EDITENV edit env variable
974 CONFIG_CMD_EEPROM * EEPROM read/write support
975 CONFIG_CMD_ELF * bootelf, bootvx
976 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
977 CONFIG_CMD_ENV_FLAGS * display details about env flags
978 CONFIG_CMD_ENV_EXISTS * check existence of env variable
979 CONFIG_CMD_EXPORTENV * export the environment
980 CONFIG_CMD_EXT2 * ext2 command support
981 CONFIG_CMD_EXT4 * ext4 command support
982 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
983 that work for multiple fs types
984 CONFIG_CMD_SAVEENV saveenv
985 CONFIG_CMD_FDC * Floppy Disk Support
986 CONFIG_CMD_FAT * FAT command support
987 CONFIG_CMD_FLASH flinfo, erase, protect
988 CONFIG_CMD_FPGA FPGA device initialization support
989 CONFIG_CMD_FUSE * Device fuse support
990 CONFIG_CMD_GETTIME * Get time since boot
991 CONFIG_CMD_GO * the 'go' command (exec code)
992 CONFIG_CMD_GREPENV * search environment
993 CONFIG_CMD_HASH * calculate hash / digest
994 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
995 CONFIG_CMD_I2C * I2C serial bus support
996 CONFIG_CMD_IDE * IDE harddisk support
997 CONFIG_CMD_IMI iminfo
998 CONFIG_CMD_IMLS List all images found in NOR flash
999 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1000 CONFIG_CMD_IMMAP * IMMR dump support
1001 CONFIG_CMD_IMPORTENV * import an environment
1002 CONFIG_CMD_INI * import data from an ini file into the env
1003 CONFIG_CMD_IRQ * irqinfo
1004 CONFIG_CMD_ITEST Integer/string test of 2 values
1005 CONFIG_CMD_JFFS2 * JFFS2 Support
1006 CONFIG_CMD_KGDB * kgdb
1007 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1008 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1010 CONFIG_CMD_LOADB loadb
1011 CONFIG_CMD_LOADS loads
1012 CONFIG_CMD_MD5SUM * print md5 message digest
1013 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1014 CONFIG_CMD_MEMINFO * Display detailed memory information
1015 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1017 CONFIG_CMD_MEMTEST * mtest
1018 CONFIG_CMD_MISC Misc functions like sleep etc
1019 CONFIG_CMD_MMC * MMC memory mapped support
1020 CONFIG_CMD_MII * MII utility commands
1021 CONFIG_CMD_MTDPARTS * MTD partition support
1022 CONFIG_CMD_NAND * NAND support
1023 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1024 CONFIG_CMD_NFS NFS support
1025 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1026 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1027 CONFIG_CMD_PCI * pciinfo
1028 CONFIG_CMD_PCMCIA * PCMCIA support
1029 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1031 CONFIG_CMD_PORTIO * Port I/O
1032 CONFIG_CMD_READ * Read raw data from partition
1033 CONFIG_CMD_REGINFO * Register dump
1034 CONFIG_CMD_RUN run command in env variable
1035 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1036 CONFIG_CMD_SAVES * save S record dump
1037 CONFIG_CMD_SCSI * SCSI Support
1038 CONFIG_CMD_SDRAM * print SDRAM configuration information
1039 (requires CONFIG_CMD_I2C)
1040 CONFIG_CMD_SETGETDCR Support for DCR Register access
1042 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1043 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1044 (requires CONFIG_CMD_MEMORY)
1045 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1046 CONFIG_CMD_SOURCE "source" command Support
1047 CONFIG_CMD_SPI * SPI serial bus support
1048 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1049 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1050 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1051 CONFIG_CMD_TIMER * access to the system tick timer
1052 CONFIG_CMD_USB * USB support
1053 CONFIG_CMD_CDP * Cisco Discover Protocol support
1054 CONFIG_CMD_MFSL * Microblaze FSL support
1055 CONFIG_CMD_XIMG Load part of Multi Image
1056 CONFIG_CMD_UUID * Generate random UUID or GUID string
1058 EXAMPLE: If you want all functions except of network
1059 support you can write:
1061 #include "config_cmd_all.h"
1062 #undef CONFIG_CMD_NET
1065 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1067 Note: Don't enable the "icache" and "dcache" commands
1068 (configuration option CONFIG_CMD_CACHE) unless you know
1069 what you (and your U-Boot users) are doing. Data
1070 cache cannot be enabled on systems like the 8xx or
1071 8260 (where accesses to the IMMR region must be
1072 uncached), and it cannot be disabled on all other
1073 systems where we (mis-) use the data cache to hold an
1074 initial stack and some data.
1077 XXX - this list needs to get updated!
1079 - Regular expression support:
1081 If this variable is defined, U-Boot is linked against
1082 the SLRE (Super Light Regular Expression) library,
1083 which adds regex support to some commands, as for
1084 example "env grep" and "setexpr".
1088 If this variable is defined, U-Boot will use a device tree
1089 to configure its devices, instead of relying on statically
1090 compiled #defines in the board file. This option is
1091 experimental and only available on a few boards. The device
1092 tree is available in the global data as gd->fdt_blob.
1094 U-Boot needs to get its device tree from somewhere. This can
1095 be done using one of the two options below:
1098 If this variable is defined, U-Boot will embed a device tree
1099 binary in its image. This device tree file should be in the
1100 board directory and called <soc>-<board>.dts. The binary file
1101 is then picked up in board_init_f() and made available through
1102 the global data structure as gd->blob.
1105 If this variable is defined, U-Boot will build a device tree
1106 binary. It will be called u-boot.dtb. Architecture-specific
1107 code will locate it at run-time. Generally this works by:
1109 cat u-boot.bin u-boot.dtb >image.bin
1111 and in fact, U-Boot does this for you, creating a file called
1112 u-boot-dtb.bin which is useful in the common case. You can
1113 still use the individual files if you need something more
1118 If this variable is defined, it enables watchdog
1119 support for the SoC. There must be support in the SoC
1120 specific code for a watchdog. For the 8xx and 8260
1121 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1122 register. When supported for a specific SoC is
1123 available, then no further board specific code should
1124 be needed to use it.
1127 When using a watchdog circuitry external to the used
1128 SoC, then define this variable and provide board
1129 specific code for the "hw_watchdog_reset" function.
1132 CONFIG_VERSION_VARIABLE
1133 If this variable is defined, an environment variable
1134 named "ver" is created by U-Boot showing the U-Boot
1135 version as printed by the "version" command.
1136 Any change to this variable will be reverted at the
1141 When CONFIG_CMD_DATE is selected, the type of the RTC
1142 has to be selected, too. Define exactly one of the
1145 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1146 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1147 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1148 CONFIG_RTC_MC146818 - use MC146818 RTC
1149 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1150 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1151 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1152 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1153 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1154 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1155 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1156 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1159 Note that if the RTC uses I2C, then the I2C interface
1160 must also be configured. See I2C Support, below.
1163 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1165 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1166 chip-ngpio pairs that tell the PCA953X driver the number of
1167 pins supported by a particular chip.
1169 Note that if the GPIO device uses I2C, then the I2C interface
1170 must also be configured. See I2C Support, below.
1172 - Timestamp Support:
1174 When CONFIG_TIMESTAMP is selected, the timestamp
1175 (date and time) of an image is printed by image
1176 commands like bootm or iminfo. This option is
1177 automatically enabled when you select CONFIG_CMD_DATE .
1179 - Partition Labels (disklabels) Supported:
1180 Zero or more of the following:
1181 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1182 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1183 Intel architecture, USB sticks, etc.
1184 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1185 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1186 bootloader. Note 2TB partition limit; see
1188 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1190 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1191 CONFIG_CMD_SCSI) you must configure support for at
1192 least one non-MTD partition type as well.
1195 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1196 board configurations files but used nowhere!
1198 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1199 be performed by calling the function
1200 ide_set_reset(int reset)
1201 which has to be defined in a board specific file
1206 Set this to enable ATAPI support.
1211 Set this to enable support for disks larger than 137GB
1212 Also look at CONFIG_SYS_64BIT_LBA.
1213 Whithout these , LBA48 support uses 32bit variables and will 'only'
1214 support disks up to 2.1TB.
1216 CONFIG_SYS_64BIT_LBA:
1217 When enabled, makes the IDE subsystem use 64bit sector addresses.
1221 At the moment only there is only support for the
1222 SYM53C8XX SCSI controller; define
1223 CONFIG_SCSI_SYM53C8XX to enable it.
1225 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1226 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1227 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1228 maximum numbers of LUNs, SCSI ID's and target
1230 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1232 The environment variable 'scsidevs' is set to the number of
1233 SCSI devices found during the last scan.
1235 - NETWORK Support (PCI):
1237 Support for Intel 8254x/8257x gigabit chips.
1240 Utility code for direct access to the SPI bus on Intel 8257x.
1241 This does not do anything useful unless you set at least one
1242 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1244 CONFIG_E1000_SPI_GENERIC
1245 Allow generic access to the SPI bus on the Intel 8257x, for
1246 example with the "sspi" command.
1249 Management command for E1000 devices. When used on devices
1250 with SPI support you can reprogram the EEPROM from U-Boot.
1252 CONFIG_E1000_FALLBACK_MAC
1253 default MAC for empty EEPROM after production.
1256 Support for Intel 82557/82559/82559ER chips.
1257 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1258 write routine for first time initialisation.
1261 Support for Digital 2114x chips.
1262 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1263 modem chip initialisation (KS8761/QS6611).
1266 Support for National dp83815 chips.
1269 Support for National dp8382[01] gigabit chips.
1271 - NETWORK Support (other):
1273 CONFIG_DRIVER_AT91EMAC
1274 Support for AT91RM9200 EMAC.
1277 Define this to use reduced MII inteface
1279 CONFIG_DRIVER_AT91EMAC_QUIET
1280 If this defined, the driver is quiet.
1281 The driver doen't show link status messages.
1283 CONFIG_CALXEDA_XGMAC
1284 Support for the Calxeda XGMAC device
1287 Support for SMSC's LAN91C96 chips.
1289 CONFIG_LAN91C96_BASE
1290 Define this to hold the physical address
1291 of the LAN91C96's I/O space
1293 CONFIG_LAN91C96_USE_32_BIT
1294 Define this to enable 32 bit addressing
1297 Support for SMSC's LAN91C111 chip
1299 CONFIG_SMC91111_BASE
1300 Define this to hold the physical address
1301 of the device (I/O space)
1303 CONFIG_SMC_USE_32_BIT
1304 Define this if data bus is 32 bits
1306 CONFIG_SMC_USE_IOFUNCS
1307 Define this to use i/o functions instead of macros
1308 (some hardware wont work with macros)
1310 CONFIG_DRIVER_TI_EMAC
1311 Support for davinci emac
1313 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1314 Define this if you have more then 3 PHYs.
1317 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1319 CONFIG_FTGMAC100_EGIGA
1320 Define this to use GE link update with gigabit PHY.
1321 Define this if FTGMAC100 is connected to gigabit PHY.
1322 If your system has 10/100 PHY only, it might not occur
1323 wrong behavior. Because PHY usually return timeout or
1324 useless data when polling gigabit status and gigabit
1325 control registers. This behavior won't affect the
1326 correctnessof 10/100 link speed update.
1329 Support for SMSC's LAN911x and LAN921x chips
1332 Define this to hold the physical address
1333 of the device (I/O space)
1335 CONFIG_SMC911X_32_BIT
1336 Define this if data bus is 32 bits
1338 CONFIG_SMC911X_16_BIT
1339 Define this if data bus is 16 bits. If your processor
1340 automatically converts one 32 bit word to two 16 bit
1341 words you may also try CONFIG_SMC911X_32_BIT.
1344 Support for Renesas on-chip Ethernet controller
1346 CONFIG_SH_ETHER_USE_PORT
1347 Define the number of ports to be used
1349 CONFIG_SH_ETHER_PHY_ADDR
1350 Define the ETH PHY's address
1352 CONFIG_SH_ETHER_CACHE_WRITEBACK
1353 If this option is set, the driver enables cache flush.
1357 Support TPM devices.
1360 Support for i2c bus TPM devices. Only one device
1361 per system is supported at this time.
1363 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1364 Define the the i2c bus number for the TPM device
1366 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1367 Define the TPM's address on the i2c bus
1369 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1370 Define the burst count bytes upper limit
1372 CONFIG_TPM_ATMEL_TWI
1373 Support for Atmel TWI TPM device. Requires I2C support.
1376 Support for generic parallel port TPM devices. Only one device
1377 per system is supported at this time.
1379 CONFIG_TPM_TIS_BASE_ADDRESS
1380 Base address where the generic TPM device is mapped
1381 to. Contemporary x86 systems usually map it at
1385 Add tpm monitor functions.
1386 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1387 provides monitor access to authorized functions.
1390 Define this to enable the TPM support library which provides
1391 functional interfaces to some TPM commands.
1392 Requires support for a TPM device.
1394 CONFIG_TPM_AUTH_SESSIONS
1395 Define this to enable authorized functions in the TPM library.
1396 Requires CONFIG_TPM and CONFIG_SHA1.
1399 At the moment only the UHCI host controller is
1400 supported (PIP405, MIP405, MPC5200); define
1401 CONFIG_USB_UHCI to enable it.
1402 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1403 and define CONFIG_USB_STORAGE to enable the USB
1406 Supported are USB Keyboards and USB Floppy drives
1408 MPC5200 USB requires additional defines:
1410 for 528 MHz Clock: 0x0001bbbb
1414 for differential drivers: 0x00001000
1415 for single ended drivers: 0x00005000
1416 for differential drivers on PSC3: 0x00000100
1417 for single ended drivers on PSC3: 0x00004100
1418 CONFIG_SYS_USB_EVENT_POLL
1419 May be defined to allow interrupt polling
1420 instead of using asynchronous interrupts
1422 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1423 txfilltuning field in the EHCI controller on reset.
1425 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1426 interval for usb hub power-on delay.(minimum 100msec)
1429 Define the below if you wish to use the USB console.
1430 Once firmware is rebuilt from a serial console issue the
1431 command "setenv stdin usbtty; setenv stdout usbtty" and
1432 attach your USB cable. The Unix command "dmesg" should print
1433 it has found a new device. The environment variable usbtty
1434 can be set to gserial or cdc_acm to enable your device to
1435 appear to a USB host as a Linux gserial device or a
1436 Common Device Class Abstract Control Model serial device.
1437 If you select usbtty = gserial you should be able to enumerate
1439 # modprobe usbserial vendor=0xVendorID product=0xProductID
1440 else if using cdc_acm, simply setting the environment
1441 variable usbtty to be cdc_acm should suffice. The following
1442 might be defined in YourBoardName.h
1445 Define this to build a UDC device
1448 Define this to have a tty type of device available to
1449 talk to the UDC device
1452 Define this to enable the high speed support for usb
1453 device and usbtty. If this feature is enabled, a routine
1454 int is_usbd_high_speed(void)
1455 also needs to be defined by the driver to dynamically poll
1456 whether the enumeration has succeded at high speed or full
1459 CONFIG_SYS_CONSOLE_IS_IN_ENV
1460 Define this if you want stdin, stdout &/or stderr to
1464 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1465 Derive USB clock from external clock "blah"
1466 - CONFIG_SYS_USB_EXTC_CLK 0x02
1468 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1469 Derive USB clock from brgclk
1470 - CONFIG_SYS_USB_BRG_CLK 0x04
1472 If you have a USB-IF assigned VendorID then you may wish to
1473 define your own vendor specific values either in BoardName.h
1474 or directly in usbd_vendor_info.h. If you don't define
1475 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1476 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1477 should pretend to be a Linux device to it's target host.
1479 CONFIG_USBD_MANUFACTURER
1480 Define this string as the name of your company for
1481 - CONFIG_USBD_MANUFACTURER "my company"
1483 CONFIG_USBD_PRODUCT_NAME
1484 Define this string as the name of your product
1485 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1487 CONFIG_USBD_VENDORID
1488 Define this as your assigned Vendor ID from the USB
1489 Implementors Forum. This *must* be a genuine Vendor ID
1490 to avoid polluting the USB namespace.
1491 - CONFIG_USBD_VENDORID 0xFFFF
1493 CONFIG_USBD_PRODUCTID
1494 Define this as the unique Product ID
1496 - CONFIG_USBD_PRODUCTID 0xFFFF
1498 - ULPI Layer Support:
1499 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1500 the generic ULPI layer. The generic layer accesses the ULPI PHY
1501 via the platform viewport, so you need both the genric layer and
1502 the viewport enabled. Currently only Chipidea/ARC based
1503 viewport is supported.
1504 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1505 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1506 If your ULPI phy needs a different reference clock than the
1507 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1508 the appropriate value in Hz.
1511 The MMC controller on the Intel PXA is supported. To
1512 enable this define CONFIG_MMC. The MMC can be
1513 accessed from the boot prompt by mapping the device
1514 to physical memory similar to flash. Command line is
1515 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1516 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1519 Support for Renesas on-chip MMCIF controller
1521 CONFIG_SH_MMCIF_ADDR
1522 Define the base address of MMCIF registers
1525 Define the clock frequency for MMCIF
1527 - USB Device Firmware Update (DFU) class support:
1529 This enables the USB portion of the DFU USB class
1532 This enables the command "dfu" which is used to have
1533 U-Boot create a DFU class device via USB. This command
1534 requires that the "dfu_alt_info" environment variable be
1535 set and define the alt settings to expose to the host.
1538 This enables support for exposing (e)MMC devices via DFU.
1541 This enables support for exposing NAND devices via DFU.
1544 This enables support for exposing RAM via DFU.
1545 Note: DFU spec refer to non-volatile memory usage, but
1546 allow usages beyond the scope of spec - here RAM usage,
1547 one that would help mostly the developer.
1549 CONFIG_SYS_DFU_DATA_BUF_SIZE
1550 Dfu transfer uses a buffer before writing data to the
1551 raw storage device. Make the size (in bytes) of this buffer
1552 configurable. The size of this buffer is also configurable
1553 through the "dfu_bufsiz" environment variable.
1555 CONFIG_SYS_DFU_MAX_FILE_SIZE
1556 When updating files rather than the raw storage device,
1557 we use a static buffer to copy the file into and then write
1558 the buffer once we've been given the whole file. Define
1559 this to the maximum filesize (in bytes) for the buffer.
1560 Default is 4 MiB if undefined.
1562 DFU_DEFAULT_POLL_TIMEOUT
1563 Poll timeout [ms], is the timeout a device can send to the
1564 host. The host must wait for this timeout before sending
1565 a subsequent DFU_GET_STATUS request to the device.
1567 DFU_MANIFEST_POLL_TIMEOUT
1568 Poll timeout [ms], which the device sends to the host when
1569 entering dfuMANIFEST state. Host waits this timeout, before
1570 sending again an USB request to the device.
1572 - Journaling Flash filesystem support:
1573 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1574 CONFIG_JFFS2_NAND_DEV
1575 Define these for a default partition on a NAND device
1577 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1578 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1579 Define these for a default partition on a NOR device
1581 CONFIG_SYS_JFFS_CUSTOM_PART
1582 Define this to create an own partition. You have to provide a
1583 function struct part_info* jffs2_part_info(int part_num)
1585 If you define only one JFFS2 partition you may also want to
1586 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1587 to disable the command chpart. This is the default when you
1588 have not defined a custom partition
1590 - FAT(File Allocation Table) filesystem write function support:
1593 Define this to enable support for saving memory data as a
1594 file in FAT formatted partition.
1596 This will also enable the command "fatwrite" enabling the
1597 user to write files to FAT.
1599 CBFS (Coreboot Filesystem) support
1602 Define this to enable support for reading from a Coreboot
1603 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1609 Define this to enable standard (PC-Style) keyboard
1613 Standard PC keyboard driver with US (is default) and
1614 GERMAN key layout (switch via environment 'keymap=de') support.
1615 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1616 for cfb_console. Supports cursor blinking.
1619 Enables a Chrome OS keyboard using the CROS_EC interface.
1620 This uses CROS_EC to communicate with a second microcontroller
1621 which provides key scans on request.
1626 Define this to enable video support (for output to
1629 CONFIG_VIDEO_CT69000
1631 Enable Chips & Technologies 69000 Video chip
1633 CONFIG_VIDEO_SMI_LYNXEM
1634 Enable Silicon Motion SMI 712/710/810 Video chip. The
1635 video output is selected via environment 'videoout'
1636 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1639 For the CT69000 and SMI_LYNXEM drivers, videomode is
1640 selected via environment 'videomode'. Two different ways
1642 - "videomode=num" 'num' is a standard LiLo mode numbers.
1643 Following standard modes are supported (* is default):
1645 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1646 -------------+---------------------------------------------
1647 8 bits | 0x301* 0x303 0x305 0x161 0x307
1648 15 bits | 0x310 0x313 0x316 0x162 0x319
1649 16 bits | 0x311 0x314 0x317 0x163 0x31A
1650 24 bits | 0x312 0x315 0x318 ? 0x31B
1651 -------------+---------------------------------------------
1652 (i.e. setenv videomode 317; saveenv; reset;)
1654 - "videomode=bootargs" all the video parameters are parsed
1655 from the bootargs. (See drivers/video/videomodes.c)
1658 CONFIG_VIDEO_SED13806
1659 Enable Epson SED13806 driver. This driver supports 8bpp
1660 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1661 or CONFIG_VIDEO_SED13806_16BPP
1664 Enable the Freescale DIU video driver. Reference boards for
1665 SOCs that have a DIU should define this macro to enable DIU
1666 support, and should also define these other macros:
1672 CONFIG_VIDEO_SW_CURSOR
1673 CONFIG_VGA_AS_SINGLE_DEVICE
1675 CONFIG_VIDEO_BMP_LOGO
1677 The DIU driver will look for the 'video-mode' environment
1678 variable, and if defined, enable the DIU as a console during
1679 boot. See the documentation file README.video for a
1680 description of this variable.
1684 Enable the VGA video / BIOS for x86. The alternative if you
1685 are using coreboot is to use the coreboot frame buffer
1692 Define this to enable a custom keyboard support.
1693 This simply calls drv_keyboard_init() which must be
1694 defined in your board-specific files.
1695 The only board using this so far is RBC823.
1697 - LCD Support: CONFIG_LCD
1699 Define this to enable LCD support (for output to LCD
1700 display); also select one of the supported displays
1701 by defining one of these:
1705 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1707 CONFIG_NEC_NL6448AC33:
1709 NEC NL6448AC33-18. Active, color, single scan.
1711 CONFIG_NEC_NL6448BC20
1713 NEC NL6448BC20-08. 6.5", 640x480.
1714 Active, color, single scan.
1716 CONFIG_NEC_NL6448BC33_54
1718 NEC NL6448BC33-54. 10.4", 640x480.
1719 Active, color, single scan.
1723 Sharp 320x240. Active, color, single scan.
1724 It isn't 16x9, and I am not sure what it is.
1726 CONFIG_SHARP_LQ64D341
1728 Sharp LQ64D341 display, 640x480.
1729 Active, color, single scan.
1733 HLD1045 display, 640x480.
1734 Active, color, single scan.
1738 Optrex CBL50840-2 NF-FW 99 22 M5
1740 Hitachi LMG6912RPFC-00T
1744 320x240. Black & white.
1746 Normally display is black on white background; define
1747 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1749 CONFIG_LCD_ALIGNMENT
1751 Normally the LCD is page-aligned (tyically 4KB). If this is
1752 defined then the LCD will be aligned to this value instead.
1753 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1754 here, since it is cheaper to change data cache settings on
1755 a per-section basis.
1757 CONFIG_CONSOLE_SCROLL_LINES
1759 When the console need to be scrolled, this is the number of
1760 lines to scroll by. It defaults to 1. Increasing this makes
1761 the console jump but can help speed up operation when scrolling
1766 Support drawing of RLE8-compressed bitmaps on the LCD.
1770 Enables an 'i2c edid' command which can read EDID
1771 information over I2C from an attached LCD display.
1773 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1775 If this option is set, the environment is checked for
1776 a variable "splashimage". If found, the usual display
1777 of logo, copyright and system information on the LCD
1778 is suppressed and the BMP image at the address
1779 specified in "splashimage" is loaded instead. The
1780 console is redirected to the "nulldev", too. This
1781 allows for a "silent" boot where a splash screen is
1782 loaded very quickly after power-on.
1784 CONFIG_SPLASHIMAGE_GUARD
1786 If this option is set, then U-Boot will prevent the environment
1787 variable "splashimage" from being set to a problematic address
1788 (see README.displaying-bmps).
1789 This option is useful for targets where, due to alignment
1790 restrictions, an improperly aligned BMP image will cause a data
1791 abort. If you think you will not have problems with unaligned
1792 accesses (for example because your toolchain prevents them)
1793 there is no need to set this option.
1795 CONFIG_SPLASH_SCREEN_ALIGN
1797 If this option is set the splash image can be freely positioned
1798 on the screen. Environment variable "splashpos" specifies the
1799 position as "x,y". If a positive number is given it is used as
1800 number of pixel from left/top. If a negative number is given it
1801 is used as number of pixel from right/bottom. You can also
1802 specify 'm' for centering the image.
1805 setenv splashpos m,m
1806 => image at center of screen
1808 setenv splashpos 30,20
1809 => image at x = 30 and y = 20
1811 setenv splashpos -10,m
1812 => vertically centered image
1813 at x = dspWidth - bmpWidth - 9
1815 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1817 If this option is set, additionally to standard BMP
1818 images, gzipped BMP images can be displayed via the
1819 splashscreen support or the bmp command.
1821 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1823 If this option is set, 8-bit RLE compressed BMP images
1824 can be displayed via the splashscreen support or the
1827 - Do compresssing for memory range:
1830 If this option is set, it would use zlib deflate method
1831 to compress the specified memory at its best effort.
1833 - Compression support:
1836 Enabled by default to support gzip compressed images.
1840 If this option is set, support for bzip2 compressed
1841 images is included. If not, only uncompressed and gzip
1842 compressed images are supported.
1844 NOTE: the bzip2 algorithm requires a lot of RAM, so
1845 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1850 If this option is set, support for lzma compressed
1853 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1854 requires an amount of dynamic memory that is given by the
1857 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1859 Where lc and lp stand for, respectively, Literal context bits
1860 and Literal pos bits.
1862 This value is upper-bounded by 14MB in the worst case. Anyway,
1863 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1864 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1865 a very small buffer.
1867 Use the lzmainfo tool to determinate the lc and lp values and
1868 then calculate the amount of needed dynamic memory (ensuring
1869 the appropriate CONFIG_SYS_MALLOC_LEN value).
1873 If this option is set, support for LZO compressed images
1879 The address of PHY on MII bus.
1881 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1883 The clock frequency of the MII bus
1887 If this option is set, support for speed/duplex
1888 detection of gigabit PHY is included.
1890 CONFIG_PHY_RESET_DELAY
1892 Some PHY like Intel LXT971A need extra delay after
1893 reset before any MII register access is possible.
1894 For such PHY, set this option to the usec delay
1895 required. (minimum 300usec for LXT971A)
1897 CONFIG_PHY_CMD_DELAY (ppc4xx)
1899 Some PHY like Intel LXT971A need extra delay after
1900 command issued before MII status register can be read
1910 Define a default value for Ethernet address to use
1911 for the respective Ethernet interface, in case this
1912 is not determined automatically.
1917 Define a default value for the IP address to use for
1918 the default Ethernet interface, in case this is not
1919 determined through e.g. bootp.
1920 (Environment variable "ipaddr")
1922 - Server IP address:
1925 Defines a default value for the IP address of a TFTP
1926 server to contact when using the "tftboot" command.
1927 (Environment variable "serverip")
1929 CONFIG_KEEP_SERVERADDR
1931 Keeps the server's MAC address, in the env 'serveraddr'
1932 for passing to bootargs (like Linux's netconsole option)
1934 - Gateway IP address:
1937 Defines a default value for the IP address of the
1938 default router where packets to other networks are
1940 (Environment variable "gatewayip")
1945 Defines a default value for the subnet mask (or
1946 routing prefix) which is used to determine if an IP
1947 address belongs to the local subnet or needs to be
1948 forwarded through a router.
1949 (Environment variable "netmask")
1951 - Multicast TFTP Mode:
1954 Defines whether you want to support multicast TFTP as per
1955 rfc-2090; for example to work with atftp. Lets lots of targets
1956 tftp down the same boot image concurrently. Note: the Ethernet
1957 driver in use must provide a function: mcast() to join/leave a
1960 - BOOTP Recovery Mode:
1961 CONFIG_BOOTP_RANDOM_DELAY
1963 If you have many targets in a network that try to
1964 boot using BOOTP, you may want to avoid that all
1965 systems send out BOOTP requests at precisely the same
1966 moment (which would happen for instance at recovery
1967 from a power failure, when all systems will try to
1968 boot, thus flooding the BOOTP server. Defining
1969 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1970 inserted before sending out BOOTP requests. The
1971 following delays are inserted then:
1973 1st BOOTP request: delay 0 ... 1 sec
1974 2nd BOOTP request: delay 0 ... 2 sec
1975 3rd BOOTP request: delay 0 ... 4 sec
1977 BOOTP requests: delay 0 ... 8 sec
1979 - DHCP Advanced Options:
1980 You can fine tune the DHCP functionality by defining
1981 CONFIG_BOOTP_* symbols:
1983 CONFIG_BOOTP_SUBNETMASK
1984 CONFIG_BOOTP_GATEWAY
1985 CONFIG_BOOTP_HOSTNAME
1986 CONFIG_BOOTP_NISDOMAIN
1987 CONFIG_BOOTP_BOOTPATH
1988 CONFIG_BOOTP_BOOTFILESIZE
1991 CONFIG_BOOTP_SEND_HOSTNAME
1992 CONFIG_BOOTP_NTPSERVER
1993 CONFIG_BOOTP_TIMEOFFSET
1994 CONFIG_BOOTP_VENDOREX
1995 CONFIG_BOOTP_MAY_FAIL
1997 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1998 environment variable, not the BOOTP server.
2000 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2001 after the configured retry count, the call will fail
2002 instead of starting over. This can be used to fail over
2003 to Link-local IP address configuration if the DHCP server
2006 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2007 serverip from a DHCP server, it is possible that more
2008 than one DNS serverip is offered to the client.
2009 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2010 serverip will be stored in the additional environment
2011 variable "dnsip2". The first DNS serverip is always
2012 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2015 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2016 to do a dynamic update of a DNS server. To do this, they
2017 need the hostname of the DHCP requester.
2018 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2019 of the "hostname" environment variable is passed as
2020 option 12 to the DHCP server.
2022 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2024 A 32bit value in microseconds for a delay between
2025 receiving a "DHCP Offer" and sending the "DHCP Request".
2026 This fixes a problem with certain DHCP servers that don't
2027 respond 100% of the time to a "DHCP request". E.g. On an
2028 AT91RM9200 processor running at 180MHz, this delay needed
2029 to be *at least* 15,000 usec before a Windows Server 2003
2030 DHCP server would reply 100% of the time. I recommend at
2031 least 50,000 usec to be safe. The alternative is to hope
2032 that one of the retries will be successful but note that
2033 the DHCP timeout and retry process takes a longer than
2036 - Link-local IP address negotiation:
2037 Negotiate with other link-local clients on the local network
2038 for an address that doesn't require explicit configuration.
2039 This is especially useful if a DHCP server cannot be guaranteed
2040 to exist in all environments that the device must operate.
2042 See doc/README.link-local for more information.
2045 CONFIG_CDP_DEVICE_ID
2047 The device id used in CDP trigger frames.
2049 CONFIG_CDP_DEVICE_ID_PREFIX
2051 A two character string which is prefixed to the MAC address
2056 A printf format string which contains the ascii name of
2057 the port. Normally is set to "eth%d" which sets
2058 eth0 for the first Ethernet, eth1 for the second etc.
2060 CONFIG_CDP_CAPABILITIES
2062 A 32bit integer which indicates the device capabilities;
2063 0x00000010 for a normal host which does not forwards.
2067 An ascii string containing the version of the software.
2071 An ascii string containing the name of the platform.
2075 A 32bit integer sent on the trigger.
2077 CONFIG_CDP_POWER_CONSUMPTION
2079 A 16bit integer containing the power consumption of the
2080 device in .1 of milliwatts.
2082 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2084 A byte containing the id of the VLAN.
2086 - Status LED: CONFIG_STATUS_LED
2088 Several configurations allow to display the current
2089 status using a LED. For instance, the LED will blink
2090 fast while running U-Boot code, stop blinking as
2091 soon as a reply to a BOOTP request was received, and
2092 start blinking slow once the Linux kernel is running
2093 (supported by a status LED driver in the Linux
2094 kernel). Defining CONFIG_STATUS_LED enables this
2100 The status LED can be connected to a GPIO pin.
2101 In such cases, the gpio_led driver can be used as a
2102 status LED backend implementation. Define CONFIG_GPIO_LED
2103 to include the gpio_led driver in the U-Boot binary.
2105 CONFIG_GPIO_LED_INVERTED_TABLE
2106 Some GPIO connected LEDs may have inverted polarity in which
2107 case the GPIO high value corresponds to LED off state and
2108 GPIO low value corresponds to LED on state.
2109 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2110 with a list of GPIO LEDs that have inverted polarity.
2112 - CAN Support: CONFIG_CAN_DRIVER
2114 Defining CONFIG_CAN_DRIVER enables CAN driver support
2115 on those systems that support this (optional)
2116 feature, like the TQM8xxL modules.
2118 - I2C Support: CONFIG_SYS_I2C
2120 This enable the NEW i2c subsystem, and will allow you to use
2121 i2c commands at the u-boot command line (as long as you set
2122 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2123 based realtime clock chips or other i2c devices. See
2124 common/cmd_i2c.c for a description of the command line
2127 ported i2c driver to the new framework:
2128 - drivers/i2c/soft_i2c.c:
2129 - activate first bus with CONFIG_SYS_I2C_SOFT define
2130 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2131 for defining speed and slave address
2132 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2133 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2134 for defining speed and slave address
2135 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2136 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2137 for defining speed and slave address
2138 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2139 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2140 for defining speed and slave address
2142 - drivers/i2c/fsl_i2c.c:
2143 - activate i2c driver with CONFIG_SYS_I2C_FSL
2144 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2145 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2146 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2148 - If your board supports a second fsl i2c bus, define
2149 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2150 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2151 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2154 - drivers/i2c/tegra_i2c.c:
2155 - activate this driver with CONFIG_SYS_I2C_TEGRA
2156 - This driver adds 4 i2c buses with a fix speed from
2157 100000 and the slave addr 0!
2159 - drivers/i2c/ppc4xx_i2c.c
2160 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2161 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2162 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2164 - drivers/i2c/i2c_mxc.c
2165 - activate this driver with CONFIG_SYS_I2C_MXC
2166 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2167 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2168 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2169 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2170 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2171 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2172 If thoses defines are not set, default value is 100000
2173 for speed, and 0 for slave.
2175 - drivers/i2c/rcar_i2c.c:
2176 - activate this driver with CONFIG_SYS_I2C_RCAR
2177 - This driver adds 4 i2c buses
2179 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2180 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2181 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2182 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2183 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2184 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2185 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2186 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2187 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2189 - drivers/i2c/sh_i2c.c:
2190 - activate this driver with CONFIG_SYS_I2C_SH
2191 - This driver adds from 2 to 5 i2c buses
2193 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2194 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2195 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2196 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2197 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2198 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2199 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2200 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2201 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2202 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2203 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2204 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2205 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2207 - drivers/i2c/omap24xx_i2c.c
2208 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2209 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2210 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2211 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2212 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2213 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2214 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2215 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2216 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2217 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2218 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2220 - drivers/i2c/zynq_i2c.c
2221 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2222 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2223 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2225 - drivers/i2c/s3c24x0_i2c.c:
2226 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2227 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2228 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2229 with a fix speed from 100000 and the slave addr 0!
2233 CONFIG_SYS_NUM_I2C_BUSES
2234 Hold the number of i2c busses you want to use. If you
2235 don't use/have i2c muxes on your i2c bus, this
2236 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2239 CONFIG_SYS_I2C_DIRECT_BUS
2240 define this, if you don't use i2c muxes on your hardware.
2241 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2244 CONFIG_SYS_I2C_MAX_HOPS
2245 define how many muxes are maximal consecutively connected
2246 on one i2c bus. If you not use i2c muxes, omit this
2249 CONFIG_SYS_I2C_BUSES
2250 hold a list of busses you want to use, only used if
2251 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2252 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2253 CONFIG_SYS_NUM_I2C_BUSES = 9:
2255 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2256 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2257 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2258 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2259 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2260 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2261 {1, {I2C_NULL_HOP}}, \
2262 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2263 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2267 bus 0 on adapter 0 without a mux
2268 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2269 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2270 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2271 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2272 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2273 bus 6 on adapter 1 without a mux
2274 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2275 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2277 If you do not have i2c muxes on your board, omit this define.
2279 - Legacy I2C Support: CONFIG_HARD_I2C
2281 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2282 provides the following compelling advantages:
2284 - more than one i2c adapter is usable
2285 - approved multibus support
2286 - better i2c mux support
2288 ** Please consider updating your I2C driver now. **
2290 These enable legacy I2C serial bus commands. Defining
2291 CONFIG_HARD_I2C will include the appropriate I2C driver
2292 for the selected CPU.
2294 This will allow you to use i2c commands at the u-boot
2295 command line (as long as you set CONFIG_CMD_I2C in
2296 CONFIG_COMMANDS) and communicate with i2c based realtime
2297 clock chips. See common/cmd_i2c.c for a description of the
2298 command line interface.
2300 CONFIG_HARD_I2C selects a hardware I2C controller.
2302 There are several other quantities that must also be
2303 defined when you define CONFIG_HARD_I2C.
2305 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2306 to be the frequency (in Hz) at which you wish your i2c bus
2307 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2308 the CPU's i2c node address).
2310 Now, the u-boot i2c code for the mpc8xx
2311 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2312 and so its address should therefore be cleared to 0 (See,
2313 eg, MPC823e User's Manual p.16-473). So, set
2314 CONFIG_SYS_I2C_SLAVE to 0.
2316 CONFIG_SYS_I2C_INIT_MPC5XXX
2318 When a board is reset during an i2c bus transfer
2319 chips might think that the current transfer is still
2320 in progress. Reset the slave devices by sending start
2321 commands until the slave device responds.
2323 That's all that's required for CONFIG_HARD_I2C.
2325 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2326 then the following macros need to be defined (examples are
2327 from include/configs/lwmon.h):
2331 (Optional). Any commands necessary to enable the I2C
2332 controller or configure ports.
2334 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2338 (Only for MPC8260 CPU). The I/O port to use (the code
2339 assumes both bits are on the same port). Valid values
2340 are 0..3 for ports A..D.
2344 The code necessary to make the I2C data line active
2345 (driven). If the data line is open collector, this
2348 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2352 The code necessary to make the I2C data line tri-stated
2353 (inactive). If the data line is open collector, this
2356 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2360 Code that returns true if the I2C data line is high,
2363 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2367 If <bit> is true, sets the I2C data line high. If it
2368 is false, it clears it (low).
2370 eg: #define I2C_SDA(bit) \
2371 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2372 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2376 If <bit> is true, sets the I2C clock line high. If it
2377 is false, it clears it (low).
2379 eg: #define I2C_SCL(bit) \
2380 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2381 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2385 This delay is invoked four times per clock cycle so this
2386 controls the rate of data transfer. The data rate thus
2387 is 1 / (I2C_DELAY * 4). Often defined to be something
2390 #define I2C_DELAY udelay(2)
2392 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2394 If your arch supports the generic GPIO framework (asm/gpio.h),
2395 then you may alternatively define the two GPIOs that are to be
2396 used as SCL / SDA. Any of the previous I2C_xxx macros will
2397 have GPIO-based defaults assigned to them as appropriate.
2399 You should define these to the GPIO value as given directly to
2400 the generic GPIO functions.
2402 CONFIG_SYS_I2C_INIT_BOARD
2404 When a board is reset during an i2c bus transfer
2405 chips might think that the current transfer is still
2406 in progress. On some boards it is possible to access
2407 the i2c SCLK line directly, either by using the
2408 processor pin as a GPIO or by having a second pin
2409 connected to the bus. If this option is defined a
2410 custom i2c_init_board() routine in boards/xxx/board.c
2411 is run early in the boot sequence.
2413 CONFIG_SYS_I2C_BOARD_LATE_INIT
2415 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2416 defined a custom i2c_board_late_init() routine in
2417 boards/xxx/board.c is run AFTER the operations in i2c_init()
2418 is completed. This callpoint can be used to unreset i2c bus
2419 using CPU i2c controller register accesses for CPUs whose i2c
2420 controller provide such a method. It is called at the end of
2421 i2c_init() to allow i2c_init operations to setup the i2c bus
2422 controller on the CPU (e.g. setting bus speed & slave address).
2424 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2426 This option enables configuration of bi_iic_fast[] flags
2427 in u-boot bd_info structure based on u-boot environment
2428 variable "i2cfast". (see also i2cfast)
2430 CONFIG_I2C_MULTI_BUS
2432 This option allows the use of multiple I2C buses, each of which
2433 must have a controller. At any point in time, only one bus is
2434 active. To switch to a different bus, use the 'i2c dev' command.
2435 Note that bus numbering is zero-based.
2437 CONFIG_SYS_I2C_NOPROBES
2439 This option specifies a list of I2C devices that will be skipped
2440 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2441 is set, specify a list of bus-device pairs. Otherwise, specify
2442 a 1D array of device addresses
2445 #undef CONFIG_I2C_MULTI_BUS
2446 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2448 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2450 #define CONFIG_I2C_MULTI_BUS
2451 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2453 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2455 CONFIG_SYS_SPD_BUS_NUM
2457 If defined, then this indicates the I2C bus number for DDR SPD.
2458 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2460 CONFIG_SYS_RTC_BUS_NUM
2462 If defined, then this indicates the I2C bus number for the RTC.
2463 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2465 CONFIG_SYS_DTT_BUS_NUM
2467 If defined, then this indicates the I2C bus number for the DTT.
2468 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2470 CONFIG_SYS_I2C_DTT_ADDR:
2472 If defined, specifies the I2C address of the DTT device.
2473 If not defined, then U-Boot uses predefined value for
2474 specified DTT device.
2476 CONFIG_SOFT_I2C_READ_REPEATED_START
2478 defining this will force the i2c_read() function in
2479 the soft_i2c driver to perform an I2C repeated start
2480 between writing the address pointer and reading the
2481 data. If this define is omitted the default behaviour
2482 of doing a stop-start sequence will be used. Most I2C
2483 devices can use either method, but some require one or
2486 - SPI Support: CONFIG_SPI
2488 Enables SPI driver (so far only tested with
2489 SPI EEPROM, also an instance works with Crystal A/D and
2490 D/As on the SACSng board)
2494 Enables the driver for SPI controller on SuperH. Currently
2495 only SH7757 is supported.
2499 Enables extended (16-bit) SPI EEPROM addressing.
2500 (symmetrical to CONFIG_I2C_X)
2504 Enables a software (bit-bang) SPI driver rather than
2505 using hardware support. This is a general purpose
2506 driver that only requires three general I/O port pins
2507 (two outputs, one input) to function. If this is
2508 defined, the board configuration must define several
2509 SPI configuration items (port pins to use, etc). For
2510 an example, see include/configs/sacsng.h.
2514 Enables a hardware SPI driver for general-purpose reads
2515 and writes. As with CONFIG_SOFT_SPI, the board configuration
2516 must define a list of chip-select function pointers.
2517 Currently supported on some MPC8xxx processors. For an
2518 example, see include/configs/mpc8349emds.h.
2522 Enables the driver for the SPI controllers on i.MX and MXC
2523 SoCs. Currently i.MX31/35/51 are supported.
2525 - FPGA Support: CONFIG_FPGA
2527 Enables FPGA subsystem.
2529 CONFIG_FPGA_<vendor>
2531 Enables support for specific chip vendors.
2534 CONFIG_FPGA_<family>
2536 Enables support for FPGA family.
2537 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2541 Specify the number of FPGA devices to support.
2543 CONFIG_SYS_FPGA_PROG_FEEDBACK
2545 Enable printing of hash marks during FPGA configuration.
2547 CONFIG_SYS_FPGA_CHECK_BUSY
2549 Enable checks on FPGA configuration interface busy
2550 status by the configuration function. This option
2551 will require a board or device specific function to
2556 If defined, a function that provides delays in the FPGA
2557 configuration driver.
2559 CONFIG_SYS_FPGA_CHECK_CTRLC
2560 Allow Control-C to interrupt FPGA configuration
2562 CONFIG_SYS_FPGA_CHECK_ERROR
2564 Check for configuration errors during FPGA bitfile
2565 loading. For example, abort during Virtex II
2566 configuration if the INIT_B line goes low (which
2567 indicated a CRC error).
2569 CONFIG_SYS_FPGA_WAIT_INIT
2571 Maximum time to wait for the INIT_B line to deassert
2572 after PROB_B has been deasserted during a Virtex II
2573 FPGA configuration sequence. The default time is 500
2576 CONFIG_SYS_FPGA_WAIT_BUSY
2578 Maximum time to wait for BUSY to deassert during
2579 Virtex II FPGA configuration. The default is 5 ms.
2581 CONFIG_SYS_FPGA_WAIT_CONFIG
2583 Time to wait after FPGA configuration. The default is
2586 - Configuration Management:
2589 If defined, this string will be added to the U-Boot
2590 version information (U_BOOT_VERSION)
2592 - Vendor Parameter Protection:
2594 U-Boot considers the values of the environment
2595 variables "serial#" (Board Serial Number) and
2596 "ethaddr" (Ethernet Address) to be parameters that
2597 are set once by the board vendor / manufacturer, and
2598 protects these variables from casual modification by
2599 the user. Once set, these variables are read-only,
2600 and write or delete attempts are rejected. You can
2601 change this behaviour:
2603 If CONFIG_ENV_OVERWRITE is #defined in your config
2604 file, the write protection for vendor parameters is
2605 completely disabled. Anybody can change or delete
2608 Alternatively, if you #define _both_ CONFIG_ETHADDR
2609 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2610 Ethernet address is installed in the environment,
2611 which can be changed exactly ONCE by the user. [The
2612 serial# is unaffected by this, i. e. it remains
2615 The same can be accomplished in a more flexible way
2616 for any variable by configuring the type of access
2617 to allow for those variables in the ".flags" variable
2618 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2623 Define this variable to enable the reservation of
2624 "protected RAM", i. e. RAM which is not overwritten
2625 by U-Boot. Define CONFIG_PRAM to hold the number of
2626 kB you want to reserve for pRAM. You can overwrite
2627 this default value by defining an environment
2628 variable "pram" to the number of kB you want to
2629 reserve. Note that the board info structure will
2630 still show the full amount of RAM. If pRAM is
2631 reserved, a new environment variable "mem" will
2632 automatically be defined to hold the amount of
2633 remaining RAM in a form that can be passed as boot
2634 argument to Linux, for instance like that:
2636 setenv bootargs ... mem=\${mem}
2639 This way you can tell Linux not to use this memory,
2640 either, which results in a memory region that will
2641 not be affected by reboots.
2643 *WARNING* If your board configuration uses automatic
2644 detection of the RAM size, you must make sure that
2645 this memory test is non-destructive. So far, the
2646 following board configurations are known to be
2649 IVMS8, IVML24, SPD8xx, TQM8xxL,
2650 HERMES, IP860, RPXlite, LWMON,
2653 - Access to physical memory region (> 4GB)
2654 Some basic support is provided for operations on memory not
2655 normally accessible to U-Boot - e.g. some architectures
2656 support access to more than 4GB of memory on 32-bit
2657 machines using physical address extension or similar.
2658 Define CONFIG_PHYSMEM to access this basic support, which
2659 currently only supports clearing the memory.
2664 Define this variable to stop the system in case of a
2665 fatal error, so that you have to reset it manually.
2666 This is probably NOT a good idea for an embedded
2667 system where you want the system to reboot
2668 automatically as fast as possible, but it may be
2669 useful during development since you can try to debug
2670 the conditions that lead to the situation.
2672 CONFIG_NET_RETRY_COUNT
2674 This variable defines the number of retries for
2675 network operations like ARP, RARP, TFTP, or BOOTP
2676 before giving up the operation. If not defined, a
2677 default value of 5 is used.
2681 Timeout waiting for an ARP reply in milliseconds.
2685 Timeout in milliseconds used in NFS protocol.
2686 If you encounter "ERROR: Cannot umount" in nfs command,
2687 try longer timeout such as
2688 #define CONFIG_NFS_TIMEOUT 10000UL
2690 - Command Interpreter:
2691 CONFIG_AUTO_COMPLETE
2693 Enable auto completion of commands using TAB.
2695 Note that this feature has NOT been implemented yet
2696 for the "hush" shell.
2699 CONFIG_SYS_HUSH_PARSER
2701 Define this variable to enable the "hush" shell (from
2702 Busybox) as command line interpreter, thus enabling
2703 powerful command line syntax like
2704 if...then...else...fi conditionals or `&&' and '||'
2705 constructs ("shell scripts").
2707 If undefined, you get the old, much simpler behaviour
2708 with a somewhat smaller memory footprint.
2711 CONFIG_SYS_PROMPT_HUSH_PS2
2713 This defines the secondary prompt string, which is
2714 printed when the command interpreter needs more input
2715 to complete a command. Usually "> ".
2719 In the current implementation, the local variables
2720 space and global environment variables space are
2721 separated. Local variables are those you define by
2722 simply typing `name=value'. To access a local
2723 variable later on, you have write `$name' or
2724 `${name}'; to execute the contents of a variable
2725 directly type `$name' at the command prompt.
2727 Global environment variables are those you use
2728 setenv/printenv to work with. To run a command stored
2729 in such a variable, you need to use the run command,
2730 and you must not use the '$' sign to access them.
2732 To store commands and special characters in a
2733 variable, please use double quotation marks
2734 surrounding the whole text of the variable, instead
2735 of the backslashes before semicolons and special
2738 - Commandline Editing and History:
2739 CONFIG_CMDLINE_EDITING
2741 Enable editing and History functions for interactive
2742 commandline input operations
2744 - Default Environment:
2745 CONFIG_EXTRA_ENV_SETTINGS
2747 Define this to contain any number of null terminated
2748 strings (variable = value pairs) that will be part of
2749 the default environment compiled into the boot image.
2751 For example, place something like this in your
2752 board's config file:
2754 #define CONFIG_EXTRA_ENV_SETTINGS \
2758 Warning: This method is based on knowledge about the
2759 internal format how the environment is stored by the
2760 U-Boot code. This is NOT an official, exported
2761 interface! Although it is unlikely that this format
2762 will change soon, there is no guarantee either.
2763 You better know what you are doing here.
2765 Note: overly (ab)use of the default environment is
2766 discouraged. Make sure to check other ways to preset
2767 the environment like the "source" command or the
2770 CONFIG_ENV_VARS_UBOOT_CONFIG
2772 Define this in order to add variables describing the
2773 U-Boot build configuration to the default environment.
2774 These will be named arch, cpu, board, vendor, and soc.
2776 Enabling this option will cause the following to be defined:
2784 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2786 Define this in order to add variables describing certain
2787 run-time determined information about the hardware to the
2788 environment. These will be named board_name, board_rev.
2790 CONFIG_DELAY_ENVIRONMENT
2792 Normally the environment is loaded when the board is
2793 intialised so that it is available to U-Boot. This inhibits
2794 that so that the environment is not available until
2795 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2796 this is instead controlled by the value of
2797 /config/load-environment.
2799 - DataFlash Support:
2800 CONFIG_HAS_DATAFLASH
2802 Defining this option enables DataFlash features and
2803 allows to read/write in Dataflash via the standard
2806 - Serial Flash support
2809 Defining this option enables SPI flash commands
2810 'sf probe/read/write/erase/update'.
2812 Usage requires an initial 'probe' to define the serial
2813 flash parameters, followed by read/write/erase/update
2816 The following defaults may be provided by the platform
2817 to handle the common case when only a single serial
2818 flash is present on the system.
2820 CONFIG_SF_DEFAULT_BUS Bus identifier
2821 CONFIG_SF_DEFAULT_CS Chip-select
2822 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2823 CONFIG_SF_DEFAULT_SPEED in Hz
2827 Define this option to include a destructive SPI flash
2830 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2832 Define this option to use the Bank addr/Extended addr
2833 support on SPI flashes which has size > 16Mbytes.
2835 CONFIG_SF_DUAL_FLASH Dual flash memories
2837 Define this option to use dual flash support where two flash
2838 memories can be connected with a given cs line.
2839 currently Xilinx Zynq qspi support these type of connections.
2841 - SystemACE Support:
2844 Adding this option adds support for Xilinx SystemACE
2845 chips attached via some sort of local bus. The address
2846 of the chip must also be defined in the
2847 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2849 #define CONFIG_SYSTEMACE
2850 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2852 When SystemACE support is added, the "ace" device type
2853 becomes available to the fat commands, i.e. fatls.
2855 - TFTP Fixed UDP Port:
2858 If this is defined, the environment variable tftpsrcp
2859 is used to supply the TFTP UDP source port value.
2860 If tftpsrcp isn't defined, the normal pseudo-random port
2861 number generator is used.
2863 Also, the environment variable tftpdstp is used to supply
2864 the TFTP UDP destination port value. If tftpdstp isn't
2865 defined, the normal port 69 is used.
2867 The purpose for tftpsrcp is to allow a TFTP server to
2868 blindly start the TFTP transfer using the pre-configured
2869 target IP address and UDP port. This has the effect of
2870 "punching through" the (Windows XP) firewall, allowing
2871 the remainder of the TFTP transfer to proceed normally.
2872 A better solution is to properly configure the firewall,
2873 but sometimes that is not allowed.
2878 This enables a generic 'hash' command which can produce
2879 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2883 Enable the hash verify command (hash -v). This adds to code
2886 CONFIG_SHA1 - support SHA1 hashing
2887 CONFIG_SHA256 - support SHA256 hashing
2889 Note: There is also a sha1sum command, which should perhaps
2890 be deprecated in favour of 'hash sha1'.
2892 - Freescale i.MX specific commands:
2893 CONFIG_CMD_HDMIDETECT
2894 This enables 'hdmidet' command which returns true if an
2895 HDMI monitor is detected. This command is i.MX 6 specific.
2898 This enables the 'bmode' (bootmode) command for forcing
2899 a boot from specific media.
2901 This is useful for forcing the ROM's usb downloader to
2902 activate upon a watchdog reset which is nice when iterating
2903 on U-Boot. Using the reset button or running bmode normal
2904 will set it back to normal. This command currently
2905 supports i.MX53 and i.MX6.
2910 This enables the RSA algorithm used for FIT image verification
2911 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2913 The signing part is build into mkimage regardless of this
2916 - bootcount support:
2917 CONFIG_BOOTCOUNT_LIMIT
2919 This enables the bootcounter support, see:
2920 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2923 enable special bootcounter support on at91sam9xe based boards.
2925 enable special bootcounter support on blackfin based boards.
2927 enable special bootcounter support on da850 based boards.
2928 CONFIG_BOOTCOUNT_RAM
2929 enable support for the bootcounter in RAM
2930 CONFIG_BOOTCOUNT_I2C
2931 enable support for the bootcounter on an i2c (like RTC) device.
2932 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2933 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2935 CONFIG_BOOTCOUNT_ALEN = address len
2937 - Show boot progress:
2938 CONFIG_SHOW_BOOT_PROGRESS
2940 Defining this option allows to add some board-
2941 specific code (calling a user-provided function
2942 "show_boot_progress(int)") that enables you to show
2943 the system's boot progress on some display (for
2944 example, some LED's) on your board. At the moment,
2945 the following checkpoints are implemented:
2947 - Detailed boot stage timing
2949 Define this option to get detailed timing of each stage
2950 of the boot process.
2952 CONFIG_BOOTSTAGE_USER_COUNT
2953 This is the number of available user bootstage records.
2954 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2955 a new ID will be allocated from this stash. If you exceed
2956 the limit, recording will stop.
2958 CONFIG_BOOTSTAGE_REPORT
2959 Define this to print a report before boot, similar to this:
2961 Timer summary in microseconds:
2964 3,575,678 3,575,678 board_init_f start
2965 3,575,695 17 arch_cpu_init A9
2966 3,575,777 82 arch_cpu_init done
2967 3,659,598 83,821 board_init_r start
2968 3,910,375 250,777 main_loop
2969 29,916,167 26,005,792 bootm_start
2970 30,361,327 445,160 start_kernel
2972 CONFIG_CMD_BOOTSTAGE
2973 Add a 'bootstage' command which supports printing a report
2974 and un/stashing of bootstage data.
2976 CONFIG_BOOTSTAGE_FDT
2977 Stash the bootstage information in the FDT. A root 'bootstage'
2978 node is created with each bootstage id as a child. Each child
2979 has a 'name' property and either 'mark' containing the
2980 mark time in microsecond, or 'accum' containing the
2981 accumulated time for that bootstage id in microseconds.
2986 name = "board_init_f";
2995 Code in the Linux kernel can find this in /proc/devicetree.
2997 Legacy uImage format:
3000 1 common/cmd_bootm.c before attempting to boot an image
3001 -1 common/cmd_bootm.c Image header has bad magic number
3002 2 common/cmd_bootm.c Image header has correct magic number
3003 -2 common/cmd_bootm.c Image header has bad checksum
3004 3 common/cmd_bootm.c Image header has correct checksum
3005 -3 common/cmd_bootm.c Image data has bad checksum
3006 4 common/cmd_bootm.c Image data has correct checksum
3007 -4 common/cmd_bootm.c Image is for unsupported architecture
3008 5 common/cmd_bootm.c Architecture check OK
3009 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3010 6 common/cmd_bootm.c Image Type check OK
3011 -6 common/cmd_bootm.c gunzip uncompression error
3012 -7 common/cmd_bootm.c Unimplemented compression type
3013 7 common/cmd_bootm.c Uncompression OK
3014 8 common/cmd_bootm.c No uncompress/copy overwrite error
3015 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3017 9 common/image.c Start initial ramdisk verification
3018 -10 common/image.c Ramdisk header has bad magic number
3019 -11 common/image.c Ramdisk header has bad checksum
3020 10 common/image.c Ramdisk header is OK
3021 -12 common/image.c Ramdisk data has bad checksum
3022 11 common/image.c Ramdisk data has correct checksum
3023 12 common/image.c Ramdisk verification complete, start loading
3024 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3025 13 common/image.c Start multifile image verification
3026 14 common/image.c No initial ramdisk, no multifile, continue.
3028 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3030 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3031 -31 post/post.c POST test failed, detected by post_output_backlog()
3032 -32 post/post.c POST test failed, detected by post_run_single()
3034 34 common/cmd_doc.c before loading a Image from a DOC device
3035 -35 common/cmd_doc.c Bad usage of "doc" command
3036 35 common/cmd_doc.c correct usage of "doc" command
3037 -36 common/cmd_doc.c No boot device
3038 36 common/cmd_doc.c correct boot device
3039 -37 common/cmd_doc.c Unknown Chip ID on boot device
3040 37 common/cmd_doc.c correct chip ID found, device available
3041 -38 common/cmd_doc.c Read Error on boot device
3042 38 common/cmd_doc.c reading Image header from DOC device OK
3043 -39 common/cmd_doc.c Image header has bad magic number
3044 39 common/cmd_doc.c Image header has correct magic number
3045 -40 common/cmd_doc.c Error reading Image from DOC device
3046 40 common/cmd_doc.c Image header has correct magic number
3047 41 common/cmd_ide.c before loading a Image from a IDE device
3048 -42 common/cmd_ide.c Bad usage of "ide" command
3049 42 common/cmd_ide.c correct usage of "ide" command
3050 -43 common/cmd_ide.c No boot device
3051 43 common/cmd_ide.c boot device found
3052 -44 common/cmd_ide.c Device not available
3053 44 common/cmd_ide.c Device available
3054 -45 common/cmd_ide.c wrong partition selected
3055 45 common/cmd_ide.c partition selected
3056 -46 common/cmd_ide.c Unknown partition table
3057 46 common/cmd_ide.c valid partition table found
3058 -47 common/cmd_ide.c Invalid partition type
3059 47 common/cmd_ide.c correct partition type
3060 -48 common/cmd_ide.c Error reading Image Header on boot device
3061 48 common/cmd_ide.c reading Image Header from IDE device OK
3062 -49 common/cmd_ide.c Image header has bad magic number
3063 49 common/cmd_ide.c Image header has correct magic number
3064 -50 common/cmd_ide.c Image header has bad checksum
3065 50 common/cmd_ide.c Image header has correct checksum
3066 -51 common/cmd_ide.c Error reading Image from IDE device
3067 51 common/cmd_ide.c reading Image from IDE device OK
3068 52 common/cmd_nand.c before loading a Image from a NAND device
3069 -53 common/cmd_nand.c Bad usage of "nand" command
3070 53 common/cmd_nand.c correct usage of "nand" command
3071 -54 common/cmd_nand.c No boot device
3072 54 common/cmd_nand.c boot device found
3073 -55 common/cmd_nand.c Unknown Chip ID on boot device
3074 55 common/cmd_nand.c correct chip ID found, device available
3075 -56 common/cmd_nand.c Error reading Image Header on boot device
3076 56 common/cmd_nand.c reading Image Header from NAND device OK
3077 -57 common/cmd_nand.c Image header has bad magic number
3078 57 common/cmd_nand.c Image header has correct magic number
3079 -58 common/cmd_nand.c Error reading Image from NAND device
3080 58 common/cmd_nand.c reading Image from NAND device OK
3082 -60 common/env_common.c Environment has a bad CRC, using default
3084 64 net/eth.c starting with Ethernet configuration.
3085 -64 net/eth.c no Ethernet found.
3086 65 net/eth.c Ethernet found.
3088 -80 common/cmd_net.c usage wrong
3089 80 common/cmd_net.c before calling NetLoop()
3090 -81 common/cmd_net.c some error in NetLoop() occurred
3091 81 common/cmd_net.c NetLoop() back without error
3092 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3093 82 common/cmd_net.c trying automatic boot
3094 83 common/cmd_net.c running "source" command
3095 -83 common/cmd_net.c some error in automatic boot or "source" command
3096 84 common/cmd_net.c end without errors
3101 100 common/cmd_bootm.c Kernel FIT Image has correct format
3102 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3103 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3104 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3105 102 common/cmd_bootm.c Kernel unit name specified
3106 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3107 103 common/cmd_bootm.c Found configuration node
3108 104 common/cmd_bootm.c Got kernel subimage node offset
3109 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3110 105 common/cmd_bootm.c Kernel subimage hash verification OK
3111 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3112 106 common/cmd_bootm.c Architecture check OK
3113 -106 common/cmd_bootm.c Kernel subimage has wrong type
3114 107 common/cmd_bootm.c Kernel subimage type OK
3115 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3116 108 common/cmd_bootm.c Got kernel subimage data/size
3117 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3118 -109 common/cmd_bootm.c Can't get kernel subimage type
3119 -110 common/cmd_bootm.c Can't get kernel subimage comp
3120 -111 common/cmd_bootm.c Can't get kernel subimage os
3121 -112 common/cmd_bootm.c Can't get kernel subimage load address
3122 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3124 120 common/image.c Start initial ramdisk verification
3125 -120 common/image.c Ramdisk FIT image has incorrect format
3126 121 common/image.c Ramdisk FIT image has correct format
3127 122 common/image.c No ramdisk subimage unit name, using configuration
3128 -122 common/image.c Can't get configuration for ramdisk subimage
3129 123 common/image.c Ramdisk unit name specified
3130 -124 common/image.c Can't get ramdisk subimage node offset
3131 125 common/image.c Got ramdisk subimage node offset
3132 -125 common/image.c Ramdisk subimage hash verification failed
3133 126 common/image.c Ramdisk subimage hash verification OK
3134 -126 common/image.c Ramdisk subimage for unsupported architecture
3135 127 common/image.c Architecture check OK
3136 -127 common/image.c Can't get ramdisk subimage data/size
3137 128 common/image.c Got ramdisk subimage data/size
3138 129 common/image.c Can't get ramdisk load address
3139 -129 common/image.c Got ramdisk load address
3141 -130 common/cmd_doc.c Incorrect FIT image format
3142 131 common/cmd_doc.c FIT image format OK
3144 -140 common/cmd_ide.c Incorrect FIT image format
3145 141 common/cmd_ide.c FIT image format OK
3147 -150 common/cmd_nand.c Incorrect FIT image format
3148 151 common/cmd_nand.c FIT image format OK
3150 - FIT image support:
3152 Enable support for the FIT uImage format.
3154 CONFIG_FIT_BEST_MATCH
3155 When no configuration is explicitly selected, default to the
3156 one whose fdt's compatibility field best matches that of
3157 U-Boot itself. A match is considered "best" if it matches the
3158 most specific compatibility entry of U-Boot's fdt's root node.
3159 The order of entries in the configuration's fdt is ignored.
3161 CONFIG_FIT_SIGNATURE
3162 This option enables signature verification of FIT uImages,
3163 using a hash signed and verified using RSA. See
3164 doc/uImage.FIT/signature.txt for more details.
3166 - Standalone program support:
3167 CONFIG_STANDALONE_LOAD_ADDR
3169 This option defines a board specific value for the
3170 address where standalone program gets loaded, thus
3171 overwriting the architecture dependent default
3174 - Frame Buffer Address:
3177 Define CONFIG_FB_ADDR if you want to use specific
3178 address for frame buffer. This is typically the case
3179 when using a graphics controller has separate video
3180 memory. U-Boot will then place the frame buffer at
3181 the given address instead of dynamically reserving it
3182 in system RAM by calling lcd_setmem(), which grabs
3183 the memory for the frame buffer depending on the
3184 configured panel size.
3186 Please see board_init_f function.
3188 - Automatic software updates via TFTP server
3190 CONFIG_UPDATE_TFTP_CNT_MAX
3191 CONFIG_UPDATE_TFTP_MSEC_MAX
3193 These options enable and control the auto-update feature;
3194 for a more detailed description refer to doc/README.update.
3196 - MTD Support (mtdparts command, UBI support)
3199 Adds the MTD device infrastructure from the Linux kernel.
3200 Needed for mtdparts command support.
3202 CONFIG_MTD_PARTITIONS
3204 Adds the MTD partitioning infrastructure from the Linux
3205 kernel. Needed for UBI support.
3210 Adds commands for interacting with MTD partitions formatted
3211 with the UBI flash translation layer
3213 Requires also defining CONFIG_RBTREE
3215 CONFIG_UBI_SILENCE_MSG
3217 Make the verbose messages from UBI stop printing. This leaves
3218 warnings and errors enabled.
3223 Adds commands for interacting with UBI volumes formatted as
3224 UBIFS. UBIFS is read-only in u-boot.
3226 Requires UBI support as well as CONFIG_LZO
3228 CONFIG_UBIFS_SILENCE_MSG
3230 Make the verbose messages from UBIFS stop printing. This leaves
3231 warnings and errors enabled.
3235 Enable building of SPL globally.
3238 LDSCRIPT for linking the SPL binary.
3240 CONFIG_SPL_MAX_FOOTPRINT
3241 Maximum size in memory allocated to the SPL, BSS included.
3242 When defined, the linker checks that the actual memory
3243 used by SPL from _start to __bss_end does not exceed it.
3244 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3245 must not be both defined at the same time.
3248 Maximum size of the SPL image (text, data, rodata, and
3249 linker lists sections), BSS excluded.
3250 When defined, the linker checks that the actual size does
3253 CONFIG_SPL_TEXT_BASE
3254 TEXT_BASE for linking the SPL binary.
3256 CONFIG_SPL_RELOC_TEXT_BASE
3257 Address to relocate to. If unspecified, this is equal to
3258 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3260 CONFIG_SPL_BSS_START_ADDR
3261 Link address for the BSS within the SPL binary.
3263 CONFIG_SPL_BSS_MAX_SIZE
3264 Maximum size in memory allocated to the SPL BSS.
3265 When defined, the linker checks that the actual memory used
3266 by SPL from __bss_start to __bss_end does not exceed it.
3267 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3268 must not be both defined at the same time.
3271 Adress of the start of the stack SPL will use
3273 CONFIG_SPL_RELOC_STACK
3274 Adress of the start of the stack SPL will use after
3275 relocation. If unspecified, this is equal to
3278 CONFIG_SYS_SPL_MALLOC_START
3279 Starting address of the malloc pool used in SPL.
3281 CONFIG_SYS_SPL_MALLOC_SIZE
3282 The size of the malloc pool used in SPL.
3284 CONFIG_SPL_FRAMEWORK
3285 Enable the SPL framework under common/. This framework
3286 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3287 NAND loading of the Linux Kernel.
3290 Enable booting directly to an OS from SPL.
3291 See also: doc/README.falcon
3293 CONFIG_SPL_DISPLAY_PRINT
3294 For ARM, enable an optional function to print more information
3295 about the running system.
3297 CONFIG_SPL_INIT_MINIMAL
3298 Arch init code should be built for a very small image
3300 CONFIG_SPL_LIBCOMMON_SUPPORT
3301 Support for common/libcommon.o in SPL binary
3303 CONFIG_SPL_LIBDISK_SUPPORT
3304 Support for disk/libdisk.o in SPL binary
3306 CONFIG_SPL_I2C_SUPPORT
3307 Support for drivers/i2c/libi2c.o in SPL binary
3309 CONFIG_SPL_GPIO_SUPPORT
3310 Support for drivers/gpio/libgpio.o in SPL binary
3312 CONFIG_SPL_MMC_SUPPORT
3313 Support for drivers/mmc/libmmc.o in SPL binary
3315 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3316 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3317 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3318 Address, size and partition on the MMC to load U-Boot from
3319 when the MMC is being used in raw mode.
3321 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3322 Sector to load kernel uImage from when MMC is being
3323 used in raw mode (for Falcon mode)
3325 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3326 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3327 Sector and number of sectors to load kernel argument
3328 parameters from when MMC is being used in raw mode
3331 CONFIG_SPL_FAT_SUPPORT
3332 Support for fs/fat/libfat.o in SPL binary
3334 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3335 Filename to read to load U-Boot when reading from FAT
3337 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3338 Filename to read to load kernel uImage when reading
3339 from FAT (for Falcon mode)
3341 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3342 Filename to read to load kernel argument parameters
3343 when reading from FAT (for Falcon mode)
3345 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3346 Set this for NAND SPL on PPC mpc83xx targets, so that
3347 start.S waits for the rest of the SPL to load before
3348 continuing (the hardware starts execution after just
3349 loading the first page rather than the full 4K).
3351 CONFIG_SPL_SKIP_RELOCATE
3352 Avoid SPL relocation
3354 CONFIG_SPL_NAND_BASE
3355 Include nand_base.c in the SPL. Requires
3356 CONFIG_SPL_NAND_DRIVERS.
3358 CONFIG_SPL_NAND_DRIVERS
3359 SPL uses normal NAND drivers, not minimal drivers.
3362 Include standard software ECC in the SPL
3364 CONFIG_SPL_NAND_SIMPLE
3365 Support for NAND boot using simple NAND drivers that
3366 expose the cmd_ctrl() interface.
3368 CONFIG_SPL_MTD_SUPPORT
3369 Support for the MTD subsystem within SPL. Useful for
3370 environment on NAND support within SPL.
3372 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3373 Set for the SPL on PPC mpc8xxx targets, support for
3374 drivers/ddr/fsl/libddr.o in SPL binary.
3376 CONFIG_SPL_COMMON_INIT_DDR
3377 Set for common ddr init with serial presence detect in
3380 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3381 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3382 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3383 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3384 CONFIG_SYS_NAND_ECCBYTES
3385 Defines the size and behavior of the NAND that SPL uses
3388 CONFIG_SPL_NAND_BOOT
3389 Add support NAND boot
3391 CONFIG_SYS_NAND_U_BOOT_OFFS
3392 Location in NAND to read U-Boot from
3394 CONFIG_SYS_NAND_U_BOOT_DST
3395 Location in memory to load U-Boot to
3397 CONFIG_SYS_NAND_U_BOOT_SIZE
3398 Size of image to load
3400 CONFIG_SYS_NAND_U_BOOT_START
3401 Entry point in loaded image to jump to
3403 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3404 Define this if you need to first read the OOB and then the
3405 data. This is used for example on davinci plattforms.
3407 CONFIG_SPL_OMAP3_ID_NAND
3408 Support for an OMAP3-specific set of functions to return the
3409 ID and MFR of the first attached NAND chip, if present.
3411 CONFIG_SPL_SERIAL_SUPPORT
3412 Support for drivers/serial/libserial.o in SPL binary
3414 CONFIG_SPL_SPI_FLASH_SUPPORT
3415 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3417 CONFIG_SPL_SPI_SUPPORT
3418 Support for drivers/spi/libspi.o in SPL binary
3420 CONFIG_SPL_RAM_DEVICE
3421 Support for running image already present in ram, in SPL binary
3423 CONFIG_SPL_LIBGENERIC_SUPPORT
3424 Support for lib/libgeneric.o in SPL binary
3426 CONFIG_SPL_ENV_SUPPORT
3427 Support for the environment operating in SPL binary
3429 CONFIG_SPL_NET_SUPPORT
3430 Support for the net/libnet.o in SPL binary.
3431 It conflicts with SPL env from storage medium specified by
3432 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3435 Image offset to which the SPL should be padded before appending
3436 the SPL payload. By default, this is defined as
3437 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3438 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3439 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3442 Final target image containing SPL and payload. Some SPLs
3443 use an arch-specific makefile fragment instead, for
3444 example if more than one image needs to be produced.
3446 CONFIG_FIT_SPL_PRINT
3447 Printing information about a FIT image adds quite a bit of
3448 code to SPL. So this is normally disabled in SPL. Use this
3449 option to re-enable it. This will affect the output of the
3450 bootm command when booting a FIT image.
3454 Enable building of TPL globally.
3457 Image offset to which the TPL should be padded before appending
3458 the TPL payload. By default, this is defined as
3459 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3460 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3461 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3466 [so far only for SMDK2400 boards]
3468 - Modem support enable:
3469 CONFIG_MODEM_SUPPORT
3471 - RTS/CTS Flow control enable:
3474 - Modem debug support:
3475 CONFIG_MODEM_SUPPORT_DEBUG
3477 Enables debugging stuff (char screen[1024], dbg())
3478 for modem support. Useful only with BDI2000.
3480 - Interrupt support (PPC):
3482 There are common interrupt_init() and timer_interrupt()
3483 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3484 for CPU specific initialization. interrupt_init_cpu()
3485 should set decrementer_count to appropriate value. If
3486 CPU resets decrementer automatically after interrupt
3487 (ppc4xx) it should set decrementer_count to zero.
3488 timer_interrupt() calls timer_interrupt_cpu() for CPU
3489 specific handling. If board has watchdog / status_led
3490 / other_activity_monitor it works automatically from
3491 general timer_interrupt().
3495 In the target system modem support is enabled when a
3496 specific key (key combination) is pressed during
3497 power-on. Otherwise U-Boot will boot normally
3498 (autoboot). The key_pressed() function is called from
3499 board_init(). Currently key_pressed() is a dummy
3500 function, returning 1 and thus enabling modem
3503 If there are no modem init strings in the
3504 environment, U-Boot proceed to autoboot; the
3505 previous output (banner, info printfs) will be
3508 See also: doc/README.Modem
3510 Board initialization settings:
3511 ------------------------------
3513 During Initialization u-boot calls a number of board specific functions
3514 to allow the preparation of board specific prerequisites, e.g. pin setup
3515 before drivers are initialized. To enable these callbacks the
3516 following configuration macros have to be defined. Currently this is
3517 architecture specific, so please check arch/your_architecture/lib/board.c
3518 typically in board_init_f() and board_init_r().
3520 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3521 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3522 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3523 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3525 Configuration Settings:
3526 -----------------------
3528 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3529 Optionally it can be defined to support 64-bit memory commands.
3531 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3532 undefine this when you're short of memory.
3534 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3535 width of the commands listed in the 'help' command output.
3537 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3538 prompt for user input.
3540 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3542 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3544 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3546 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3547 the application (usually a Linux kernel) when it is
3550 - CONFIG_SYS_BAUDRATE_TABLE:
3551 List of legal baudrate settings for this board.
3553 - CONFIG_SYS_CONSOLE_INFO_QUIET
3554 Suppress display of console information at boot.
3556 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3557 If the board specific function
3558 extern int overwrite_console (void);
3559 returns 1, the stdin, stderr and stdout are switched to the
3560 serial port, else the settings in the environment are used.
3562 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3563 Enable the call to overwrite_console().
3565 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3566 Enable overwrite of previous console environment settings.
3568 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3569 Begin and End addresses of the area used by the
3572 - CONFIG_SYS_ALT_MEMTEST:
3573 Enable an alternate, more extensive memory test.
3575 - CONFIG_SYS_MEMTEST_SCRATCH:
3576 Scratch address used by the alternate memory test
3577 You only need to set this if address zero isn't writeable
3579 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3580 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3581 this specified memory area will get subtracted from the top
3582 (end) of RAM and won't get "touched" at all by U-Boot. By
3583 fixing up gd->ram_size the Linux kernel should gets passed
3584 the now "corrected" memory size and won't touch it either.
3585 This should work for arch/ppc and arch/powerpc. Only Linux
3586 board ports in arch/powerpc with bootwrapper support that
3587 recalculate the memory size from the SDRAM controller setup
3588 will have to get fixed in Linux additionally.
3590 This option can be used as a workaround for the 440EPx/GRx
3591 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3594 WARNING: Please make sure that this value is a multiple of
3595 the Linux page size (normally 4k). If this is not the case,
3596 then the end address of the Linux memory will be located at a
3597 non page size aligned address and this could cause major
3600 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3601 Enable temporary baudrate change while serial download
3603 - CONFIG_SYS_SDRAM_BASE:
3604 Physical start address of SDRAM. _Must_ be 0 here.
3606 - CONFIG_SYS_MBIO_BASE:
3607 Physical start address of Motherboard I/O (if using a
3610 - CONFIG_SYS_FLASH_BASE:
3611 Physical start address of Flash memory.
3613 - CONFIG_SYS_MONITOR_BASE:
3614 Physical start address of boot monitor code (set by
3615 make config files to be same as the text base address
3616 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3617 CONFIG_SYS_FLASH_BASE when booting from flash.
3619 - CONFIG_SYS_MONITOR_LEN:
3620 Size of memory reserved for monitor code, used to
3621 determine _at_compile_time_ (!) if the environment is
3622 embedded within the U-Boot image, or in a separate
3625 - CONFIG_SYS_MALLOC_LEN:
3626 Size of DRAM reserved for malloc() use.
3628 - CONFIG_SYS_BOOTM_LEN:
3629 Normally compressed uImages are limited to an
3630 uncompressed size of 8 MBytes. If this is not enough,
3631 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3632 to adjust this setting to your needs.
3634 - CONFIG_SYS_BOOTMAPSZ:
3635 Maximum size of memory mapped by the startup code of
3636 the Linux kernel; all data that must be processed by
3637 the Linux kernel (bd_info, boot arguments, FDT blob if
3638 used) must be put below this limit, unless "bootm_low"
3639 environment variable is defined and non-zero. In such case
3640 all data for the Linux kernel must be between "bootm_low"
3641 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3642 variable "bootm_mapsize" will override the value of
3643 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3644 then the value in "bootm_size" will be used instead.
3646 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3647 Enable initrd_high functionality. If defined then the
3648 initrd_high feature is enabled and the bootm ramdisk subcommand
3651 - CONFIG_SYS_BOOT_GET_CMDLINE:
3652 Enables allocating and saving kernel cmdline in space between
3653 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3655 - CONFIG_SYS_BOOT_GET_KBD:
3656 Enables allocating and saving a kernel copy of the bd_info in
3657 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3659 - CONFIG_SYS_MAX_FLASH_BANKS:
3660 Max number of Flash memory banks
3662 - CONFIG_SYS_MAX_FLASH_SECT:
3663 Max number of sectors on a Flash chip
3665 - CONFIG_SYS_FLASH_ERASE_TOUT:
3666 Timeout for Flash erase operations (in ms)
3668 - CONFIG_SYS_FLASH_WRITE_TOUT:
3669 Timeout for Flash write operations (in ms)
3671 - CONFIG_SYS_FLASH_LOCK_TOUT
3672 Timeout for Flash set sector lock bit operation (in ms)
3674 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3675 Timeout for Flash clear lock bits operation (in ms)
3677 - CONFIG_SYS_FLASH_PROTECTION
3678 If defined, hardware flash sectors protection is used
3679 instead of U-Boot software protection.
3681 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3683 Enable TFTP transfers directly to flash memory;
3684 without this option such a download has to be
3685 performed in two steps: (1) download to RAM, and (2)
3686 copy from RAM to flash.
3688 The two-step approach is usually more reliable, since
3689 you can check if the download worked before you erase
3690 the flash, but in some situations (when system RAM is
3691 too limited to allow for a temporary copy of the
3692 downloaded image) this option may be very useful.
3694 - CONFIG_SYS_FLASH_CFI:
3695 Define if the flash driver uses extra elements in the
3696 common flash structure for storing flash geometry.
3698 - CONFIG_FLASH_CFI_DRIVER
3699 This option also enables the building of the cfi_flash driver
3700 in the drivers directory
3702 - CONFIG_FLASH_CFI_MTD
3703 This option enables the building of the cfi_mtd driver
3704 in the drivers directory. The driver exports CFI flash
3707 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3708 Use buffered writes to flash.
3710 - CONFIG_FLASH_SPANSION_S29WS_N
3711 s29ws-n MirrorBit flash has non-standard addresses for buffered
3714 - CONFIG_SYS_FLASH_QUIET_TEST
3715 If this option is defined, the common CFI flash doesn't
3716 print it's warning upon not recognized FLASH banks. This
3717 is useful, if some of the configured banks are only
3718 optionally available.
3720 - CONFIG_FLASH_SHOW_PROGRESS
3721 If defined (must be an integer), print out countdown
3722 digits and dots. Recommended value: 45 (9..1) for 80
3723 column displays, 15 (3..1) for 40 column displays.
3725 - CONFIG_FLASH_VERIFY
3726 If defined, the content of the flash (destination) is compared
3727 against the source after the write operation. An error message
3728 will be printed when the contents are not identical.
3729 Please note that this option is useless in nearly all cases,
3730 since such flash programming errors usually are detected earlier
3731 while unprotecting/erasing/programming. Please only enable
3732 this option if you really know what you are doing.
3734 - CONFIG_SYS_RX_ETH_BUFFER:
3735 Defines the number of Ethernet receive buffers. On some
3736 Ethernet controllers it is recommended to set this value
3737 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3738 buffers can be full shortly after enabling the interface
3739 on high Ethernet traffic.
3740 Defaults to 4 if not defined.
3742 - CONFIG_ENV_MAX_ENTRIES
3744 Maximum number of entries in the hash table that is used
3745 internally to store the environment settings. The default
3746 setting is supposed to be generous and should work in most
3747 cases. This setting can be used to tune behaviour; see
3748 lib/hashtable.c for details.
3750 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3751 - CONFIG_ENV_FLAGS_LIST_STATIC
3752 Enable validation of the values given to environment variables when
3753 calling env set. Variables can be restricted to only decimal,
3754 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3755 the variables can also be restricted to IP address or MAC address.
3757 The format of the list is:
3758 type_attribute = [s|d|x|b|i|m]
3759 access_atribute = [a|r|o|c]
3760 attributes = type_attribute[access_atribute]
3761 entry = variable_name[:attributes]
3764 The type attributes are:
3765 s - String (default)
3768 b - Boolean ([1yYtT|0nNfF])
3772 The access attributes are:
3778 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3779 Define this to a list (string) to define the ".flags"
3780 envirnoment variable in the default or embedded environment.
3782 - CONFIG_ENV_FLAGS_LIST_STATIC
3783 Define this to a list (string) to define validation that
3784 should be done if an entry is not found in the ".flags"
3785 environment variable. To override a setting in the static
3786 list, simply add an entry for the same variable name to the
3789 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3790 If defined, don't allow the -f switch to env set override variable
3793 - CONFIG_SYS_GENERIC_BOARD
3794 This selects the architecture-generic board system instead of the
3795 architecture-specific board files. It is intended to move boards
3796 to this new framework over time. Defining this will disable the
3797 arch/foo/lib/board.c file and use common/board_f.c and
3798 common/board_r.c instead. To use this option your architecture
3799 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3800 its config.mk file). If you find problems enabling this option on
3801 your board please report the problem and send patches!
3803 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3804 This is set by OMAP boards for the max time that reset should
3805 be asserted. See doc/README.omap-reset-time for details on how
3806 the value can be calulated on a given board.
3808 The following definitions that deal with the placement and management
3809 of environment data (variable area); in general, we support the
3810 following configurations:
3812 - CONFIG_BUILD_ENVCRC:
3814 Builds up envcrc with the target environment so that external utils
3815 may easily extract it and embed it in final U-Boot images.
3817 - CONFIG_ENV_IS_IN_FLASH:
3819 Define this if the environment is in flash memory.
3821 a) The environment occupies one whole flash sector, which is
3822 "embedded" in the text segment with the U-Boot code. This
3823 happens usually with "bottom boot sector" or "top boot
3824 sector" type flash chips, which have several smaller
3825 sectors at the start or the end. For instance, such a
3826 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3827 such a case you would place the environment in one of the
3828 4 kB sectors - with U-Boot code before and after it. With
3829 "top boot sector" type flash chips, you would put the
3830 environment in one of the last sectors, leaving a gap
3831 between U-Boot and the environment.
3833 - CONFIG_ENV_OFFSET:
3835 Offset of environment data (variable area) to the
3836 beginning of flash memory; for instance, with bottom boot
3837 type flash chips the second sector can be used: the offset
3838 for this sector is given here.
3840 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3844 This is just another way to specify the start address of
3845 the flash sector containing the environment (instead of
3848 - CONFIG_ENV_SECT_SIZE:
3850 Size of the sector containing the environment.
3853 b) Sometimes flash chips have few, equal sized, BIG sectors.
3854 In such a case you don't want to spend a whole sector for
3859 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3860 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3861 of this flash sector for the environment. This saves
3862 memory for the RAM copy of the environment.
3864 It may also save flash memory if you decide to use this
3865 when your environment is "embedded" within U-Boot code,
3866 since then the remainder of the flash sector could be used
3867 for U-Boot code. It should be pointed out that this is
3868 STRONGLY DISCOURAGED from a robustness point of view:
3869 updating the environment in flash makes it always
3870 necessary to erase the WHOLE sector. If something goes
3871 wrong before the contents has been restored from a copy in
3872 RAM, your target system will be dead.
3874 - CONFIG_ENV_ADDR_REDUND
3875 CONFIG_ENV_SIZE_REDUND
3877 These settings describe a second storage area used to hold
3878 a redundant copy of the environment data, so that there is
3879 a valid backup copy in case there is a power failure during
3880 a "saveenv" operation.
3882 BE CAREFUL! Any changes to the flash layout, and some changes to the
3883 source code will make it necessary to adapt <board>/u-boot.lds*
3887 - CONFIG_ENV_IS_IN_NVRAM:
3889 Define this if you have some non-volatile memory device
3890 (NVRAM, battery buffered SRAM) which you want to use for the
3896 These two #defines are used to determine the memory area you
3897 want to use for environment. It is assumed that this memory
3898 can just be read and written to, without any special
3901 BE CAREFUL! The first access to the environment happens quite early
3902 in U-Boot initalization (when we try to get the setting of for the
3903 console baudrate). You *MUST* have mapped your NVRAM area then, or
3906 Please note that even with NVRAM we still use a copy of the
3907 environment in RAM: we could work on NVRAM directly, but we want to
3908 keep settings there always unmodified except somebody uses "saveenv"
3909 to save the current settings.
3912 - CONFIG_ENV_IS_IN_EEPROM:
3914 Use this if you have an EEPROM or similar serial access
3915 device and a driver for it.
3917 - CONFIG_ENV_OFFSET:
3920 These two #defines specify the offset and size of the
3921 environment area within the total memory of your EEPROM.
3923 - CONFIG_SYS_I2C_EEPROM_ADDR:
3924 If defined, specified the chip address of the EEPROM device.
3925 The default address is zero.
3927 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3928 If defined, the number of bits used to address bytes in a
3929 single page in the EEPROM device. A 64 byte page, for example
3930 would require six bits.
3932 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3933 If defined, the number of milliseconds to delay between
3934 page writes. The default is zero milliseconds.
3936 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3937 The length in bytes of the EEPROM memory array address. Note
3938 that this is NOT the chip address length!
3940 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3941 EEPROM chips that implement "address overflow" are ones
3942 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3943 address and the extra bits end up in the "chip address" bit
3944 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3947 Note that we consider the length of the address field to
3948 still be one byte because the extra address bits are hidden
3949 in the chip address.
3951 - CONFIG_SYS_EEPROM_SIZE:
3952 The size in bytes of the EEPROM device.
3954 - CONFIG_ENV_EEPROM_IS_ON_I2C
3955 define this, if you have I2C and SPI activated, and your
3956 EEPROM, which holds the environment, is on the I2C bus.
3958 - CONFIG_I2C_ENV_EEPROM_BUS
3959 if you have an Environment on an EEPROM reached over
3960 I2C muxes, you can define here, how to reach this
3961 EEPROM. For example:
3963 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3965 EEPROM which holds the environment, is reached over
3966 a pca9547 i2c mux with address 0x70, channel 3.
3968 - CONFIG_ENV_IS_IN_DATAFLASH:
3970 Define this if you have a DataFlash memory device which you
3971 want to use for the environment.
3973 - CONFIG_ENV_OFFSET:
3977 These three #defines specify the offset and size of the
3978 environment area within the total memory of your DataFlash placed
3979 at the specified address.
3981 - CONFIG_ENV_IS_IN_REMOTE:
3983 Define this if you have a remote memory space which you
3984 want to use for the local device's environment.
3989 These two #defines specify the address and size of the
3990 environment area within the remote memory space. The
3991 local device can get the environment from remote memory
3992 space by SRIO or PCIE links.
3994 BE CAREFUL! For some special cases, the local device can not use
3995 "saveenv" command. For example, the local device will get the
3996 environment stored in a remote NOR flash by SRIO or PCIE link,
3997 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3999 - CONFIG_ENV_IS_IN_NAND:
4001 Define this if you have a NAND device which you want to use
4002 for the environment.
4004 - CONFIG_ENV_OFFSET:
4007 These two #defines specify the offset and size of the environment
4008 area within the first NAND device. CONFIG_ENV_OFFSET must be
4009 aligned to an erase block boundary.
4011 - CONFIG_ENV_OFFSET_REDUND (optional):
4013 This setting describes a second storage area of CONFIG_ENV_SIZE
4014 size used to hold a redundant copy of the environment data, so
4015 that there is a valid backup copy in case there is a power failure
4016 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4017 aligned to an erase block boundary.
4019 - CONFIG_ENV_RANGE (optional):
4021 Specifies the length of the region in which the environment
4022 can be written. This should be a multiple of the NAND device's
4023 block size. Specifying a range with more erase blocks than
4024 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4025 the range to be avoided.
4027 - CONFIG_ENV_OFFSET_OOB (optional):
4029 Enables support for dynamically retrieving the offset of the
4030 environment from block zero's out-of-band data. The
4031 "nand env.oob" command can be used to record this offset.
4032 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4033 using CONFIG_ENV_OFFSET_OOB.
4035 - CONFIG_NAND_ENV_DST
4037 Defines address in RAM to which the nand_spl code should copy the
4038 environment. If redundant environment is used, it will be copied to
4039 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4041 - CONFIG_ENV_IS_IN_UBI:
4043 Define this if you have an UBI volume that you want to use for the
4044 environment. This has the benefit of wear-leveling the environment
4045 accesses, which is important on NAND.
4047 - CONFIG_ENV_UBI_PART:
4049 Define this to a string that is the mtd partition containing the UBI.
4051 - CONFIG_ENV_UBI_VOLUME:
4053 Define this to the name of the volume that you want to store the
4056 - CONFIG_ENV_UBI_VOLUME_REDUND:
4058 Define this to the name of another volume to store a second copy of
4059 the environment in. This will enable redundant environments in UBI.
4060 It is assumed that both volumes are in the same MTD partition.
4062 - CONFIG_UBI_SILENCE_MSG
4063 - CONFIG_UBIFS_SILENCE_MSG
4065 You will probably want to define these to avoid a really noisy system
4066 when storing the env in UBI.
4068 - CONFIG_ENV_IS_IN_MMC:
4070 Define this if you have an MMC device which you want to use for the
4073 - CONFIG_SYS_MMC_ENV_DEV:
4075 Specifies which MMC device the environment is stored in.
4077 - CONFIG_SYS_MMC_ENV_PART (optional):
4079 Specifies which MMC partition the environment is stored in. If not
4080 set, defaults to partition 0, the user area. Common values might be
4081 1 (first MMC boot partition), 2 (second MMC boot partition).
4083 - CONFIG_ENV_OFFSET:
4086 These two #defines specify the offset and size of the environment
4087 area within the specified MMC device.
4089 If offset is positive (the usual case), it is treated as relative to
4090 the start of the MMC partition. If offset is negative, it is treated
4091 as relative to the end of the MMC partition. This can be useful if
4092 your board may be fitted with different MMC devices, which have
4093 different sizes for the MMC partitions, and you always want the
4094 environment placed at the very end of the partition, to leave the
4095 maximum possible space before it, to store other data.
4097 These two values are in units of bytes, but must be aligned to an
4098 MMC sector boundary.
4100 - CONFIG_ENV_OFFSET_REDUND (optional):
4102 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4103 hold a redundant copy of the environment data. This provides a
4104 valid backup copy in case the other copy is corrupted, e.g. due
4105 to a power failure during a "saveenv" operation.
4107 This value may also be positive or negative; this is handled in the
4108 same way as CONFIG_ENV_OFFSET.
4110 This value is also in units of bytes, but must also be aligned to
4111 an MMC sector boundary.
4113 - CONFIG_ENV_SIZE_REDUND (optional):
4115 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4116 set. If this value is set, it must be set to the same value as
4119 - CONFIG_SYS_SPI_INIT_OFFSET
4121 Defines offset to the initial SPI buffer area in DPRAM. The
4122 area is used at an early stage (ROM part) if the environment
4123 is configured to reside in the SPI EEPROM: We need a 520 byte
4124 scratch DPRAM area. It is used between the two initialization
4125 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4126 to be a good choice since it makes it far enough from the
4127 start of the data area as well as from the stack pointer.
4129 Please note that the environment is read-only until the monitor
4130 has been relocated to RAM and a RAM copy of the environment has been
4131 created; also, when using EEPROM you will have to use getenv_f()
4132 until then to read environment variables.
4134 The environment is protected by a CRC32 checksum. Before the monitor
4135 is relocated into RAM, as a result of a bad CRC you will be working
4136 with the compiled-in default environment - *silently*!!! [This is
4137 necessary, because the first environment variable we need is the
4138 "baudrate" setting for the console - if we have a bad CRC, we don't
4139 have any device yet where we could complain.]
4141 Note: once the monitor has been relocated, then it will complain if
4142 the default environment is used; a new CRC is computed as soon as you
4143 use the "saveenv" command to store a valid environment.
4145 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4146 Echo the inverted Ethernet link state to the fault LED.
4148 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4149 also needs to be defined.
4151 - CONFIG_SYS_FAULT_MII_ADDR:
4152 MII address of the PHY to check for the Ethernet link state.
4154 - CONFIG_NS16550_MIN_FUNCTIONS:
4155 Define this if you desire to only have use of the NS16550_init
4156 and NS16550_putc functions for the serial driver located at
4157 drivers/serial/ns16550.c. This option is useful for saving
4158 space for already greatly restricted images, including but not
4159 limited to NAND_SPL configurations.
4161 - CONFIG_DISPLAY_BOARDINFO
4162 Display information about the board that U-Boot is running on
4163 when U-Boot starts up. The board function checkboard() is called
4166 - CONFIG_DISPLAY_BOARDINFO_LATE
4167 Similar to the previous option, but display this information
4168 later, once stdio is running and output goes to the LCD, if
4171 Low Level (hardware related) configuration options:
4172 ---------------------------------------------------
4174 - CONFIG_SYS_CACHELINE_SIZE:
4175 Cache Line Size of the CPU.
4177 - CONFIG_SYS_DEFAULT_IMMR:
4178 Default address of the IMMR after system reset.
4180 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4181 and RPXsuper) to be able to adjust the position of
4182 the IMMR register after a reset.
4184 - CONFIG_SYS_CCSRBAR_DEFAULT:
4185 Default (power-on reset) physical address of CCSR on Freescale
4188 - CONFIG_SYS_CCSRBAR:
4189 Virtual address of CCSR. On a 32-bit build, this is typically
4190 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4192 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4193 for cross-platform code that uses that macro instead.
4195 - CONFIG_SYS_CCSRBAR_PHYS:
4196 Physical address of CCSR. CCSR can be relocated to a new
4197 physical address, if desired. In this case, this macro should
4198 be set to that address. Otherwise, it should be set to the
4199 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4200 is typically relocated on 36-bit builds. It is recommended
4201 that this macro be defined via the _HIGH and _LOW macros:
4203 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4204 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4206 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4207 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4208 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4209 used in assembly code, so it must not contain typecasts or
4210 integer size suffixes (e.g. "ULL").
4212 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4213 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4214 used in assembly code, so it must not contain typecasts or
4215 integer size suffixes (e.g. "ULL").
4217 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4218 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4219 forced to a value that ensures that CCSR is not relocated.
4221 - Floppy Disk Support:
4222 CONFIG_SYS_FDC_DRIVE_NUMBER
4224 the default drive number (default value 0)
4226 CONFIG_SYS_ISA_IO_STRIDE
4228 defines the spacing between FDC chipset registers
4231 CONFIG_SYS_ISA_IO_OFFSET
4233 defines the offset of register from address. It
4234 depends on which part of the data bus is connected to
4235 the FDC chipset. (default value 0)
4237 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4238 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4241 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4242 fdc_hw_init() is called at the beginning of the FDC
4243 setup. fdc_hw_init() must be provided by the board
4244 source code. It is used to make hardware dependant
4248 Most IDE controllers were designed to be connected with PCI
4249 interface. Only few of them were designed for AHB interface.
4250 When software is doing ATA command and data transfer to
4251 IDE devices through IDE-AHB controller, some additional
4252 registers accessing to these kind of IDE-AHB controller
4255 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4256 DO NOT CHANGE unless you know exactly what you're
4257 doing! (11-4) [MPC8xx/82xx systems only]
4259 - CONFIG_SYS_INIT_RAM_ADDR:
4261 Start address of memory area that can be used for
4262 initial data and stack; please note that this must be
4263 writable memory that is working WITHOUT special
4264 initialization, i. e. you CANNOT use normal RAM which
4265 will become available only after programming the
4266 memory controller and running certain initialization
4269 U-Boot uses the following memory types:
4270 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4271 - MPC824X: data cache
4272 - PPC4xx: data cache
4274 - CONFIG_SYS_GBL_DATA_OFFSET:
4276 Offset of the initial data structure in the memory
4277 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4278 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4279 data is located at the end of the available space
4280 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4281 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4282 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4283 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4286 On the MPC824X (or other systems that use the data
4287 cache for initial memory) the address chosen for
4288 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4289 point to an otherwise UNUSED address space between
4290 the top of RAM and the start of the PCI space.
4292 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4294 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4296 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4298 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4300 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4302 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4304 - CONFIG_SYS_OR_TIMING_SDRAM:
4307 - CONFIG_SYS_MAMR_PTA:
4308 periodic timer for refresh
4310 - CONFIG_SYS_DER: Debug Event Register (37-47)
4312 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4313 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4314 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4315 CONFIG_SYS_BR1_PRELIM:
4316 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4318 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4319 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4320 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4321 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4323 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4324 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4325 Machine Mode Register and Memory Periodic Timer
4326 Prescaler definitions (SDRAM timing)
4328 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4329 enable I2C microcode relocation patch (MPC8xx);
4330 define relocation offset in DPRAM [DSP2]
4332 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4333 enable SMC microcode relocation patch (MPC8xx);
4334 define relocation offset in DPRAM [SMC1]
4336 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4337 enable SPI microcode relocation patch (MPC8xx);
4338 define relocation offset in DPRAM [SCC4]
4340 - CONFIG_SYS_USE_OSCCLK:
4341 Use OSCM clock mode on MBX8xx board. Be careful,
4342 wrong setting might damage your board. Read
4343 doc/README.MBX before setting this variable!
4345 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4346 Offset of the bootmode word in DPRAM used by post
4347 (Power On Self Tests). This definition overrides
4348 #define'd default value in commproc.h resp.
4351 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4352 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4353 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4354 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4355 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4356 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4357 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4358 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4359 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4361 - CONFIG_PCI_DISABLE_PCIE:
4362 Disable PCI-Express on systems where it is supported but not
4365 - CONFIG_PCI_ENUM_ONLY
4366 Only scan through and get the devices on the busses.
4367 Don't do any setup work, presumably because someone or
4368 something has already done it, and we don't need to do it
4369 a second time. Useful for platforms that are pre-booted
4370 by coreboot or similar.
4372 - CONFIG_PCI_INDIRECT_BRIDGE:
4373 Enable support for indirect PCI bridges.
4376 Chip has SRIO or not
4379 Board has SRIO 1 port available
4382 Board has SRIO 2 port available
4384 - CONFIG_SRIO_PCIE_BOOT_MASTER
4385 Board can support master function for Boot from SRIO and PCIE
4387 - CONFIG_SYS_SRIOn_MEM_VIRT:
4388 Virtual Address of SRIO port 'n' memory region
4390 - CONFIG_SYS_SRIOn_MEM_PHYS:
4391 Physical Address of SRIO port 'n' memory region
4393 - CONFIG_SYS_SRIOn_MEM_SIZE:
4394 Size of SRIO port 'n' memory region
4396 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4397 Defined to tell the NAND controller that the NAND chip is using
4399 Not all NAND drivers use this symbol.
4400 Example of drivers that use it:
4401 - drivers/mtd/nand/ndfc.c
4402 - drivers/mtd/nand/mxc_nand.c
4404 - CONFIG_SYS_NDFC_EBC0_CFG
4405 Sets the EBC0_CFG register for the NDFC. If not defined
4406 a default value will be used.
4409 Get DDR timing information from an I2C EEPROM. Common
4410 with pluggable memory modules such as SODIMMs
4413 I2C address of the SPD EEPROM
4415 - CONFIG_SYS_SPD_BUS_NUM
4416 If SPD EEPROM is on an I2C bus other than the first
4417 one, specify here. Note that the value must resolve
4418 to something your driver can deal with.
4420 - CONFIG_SYS_DDR_RAW_TIMING
4421 Get DDR timing information from other than SPD. Common with
4422 soldered DDR chips onboard without SPD. DDR raw timing
4423 parameters are extracted from datasheet and hard-coded into
4424 header files or board specific files.
4426 - CONFIG_FSL_DDR_INTERACTIVE
4427 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4429 - CONFIG_SYS_83XX_DDR_USES_CS0
4430 Only for 83xx systems. If specified, then DDR should
4431 be configured using CS0 and CS1 instead of CS2 and CS3.
4433 - CONFIG_ETHER_ON_FEC[12]
4434 Define to enable FEC[12] on a 8xx series processor.
4436 - CONFIG_FEC[12]_PHY
4437 Define to the hardcoded PHY address which corresponds
4438 to the given FEC; i. e.
4439 #define CONFIG_FEC1_PHY 4
4440 means that the PHY with address 4 is connected to FEC1
4442 When set to -1, means to probe for first available.
4444 - CONFIG_FEC[12]_PHY_NORXERR
4445 The PHY does not have a RXERR line (RMII only).
4446 (so program the FEC to ignore it).
4449 Enable RMII mode for all FECs.
4450 Note that this is a global option, we can't
4451 have one FEC in standard MII mode and another in RMII mode.
4453 - CONFIG_CRC32_VERIFY
4454 Add a verify option to the crc32 command.
4457 => crc32 -v <address> <count> <crc32>
4459 Where address/count indicate a memory area
4460 and crc32 is the correct crc32 which the
4464 Add the "loopw" memory command. This only takes effect if
4465 the memory commands are activated globally (CONFIG_CMD_MEM).
4468 Add the "mdc" and "mwc" memory commands. These are cyclic
4473 This command will print 4 bytes (10,11,12,13) each 500 ms.
4475 => mwc.l 100 12345678 10
4476 This command will write 12345678 to address 100 all 10 ms.
4478 This only takes effect if the memory commands are activated
4479 globally (CONFIG_CMD_MEM).
4481 - CONFIG_SKIP_LOWLEVEL_INIT
4482 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4483 low level initializations (like setting up the memory
4484 controller) are omitted and/or U-Boot does not
4485 relocate itself into RAM.
4487 Normally this variable MUST NOT be defined. The only
4488 exception is when U-Boot is loaded (to RAM) by some
4489 other boot loader or by a debugger which performs
4490 these initializations itself.
4493 Modifies the behaviour of start.S when compiling a loader
4494 that is executed before the actual U-Boot. E.g. when
4495 compiling a NAND SPL.
4498 Modifies the behaviour of start.S when compiling a loader
4499 that is executed after the SPL and before the actual U-Boot.
4500 It is loaded by the SPL.
4502 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4503 Only for 85xx systems. If this variable is specified, the section
4504 .resetvec is not kept and the section .bootpg is placed in the
4505 previous 4k of the .text section.
4507 - CONFIG_ARCH_MAP_SYSMEM
4508 Generally U-Boot (and in particular the md command) uses
4509 effective address. It is therefore not necessary to regard
4510 U-Boot address as virtual addresses that need to be translated
4511 to physical addresses. However, sandbox requires this, since
4512 it maintains its own little RAM buffer which contains all
4513 addressable memory. This option causes some memory accesses
4514 to be mapped through map_sysmem() / unmap_sysmem().
4516 - CONFIG_USE_ARCH_MEMCPY
4517 CONFIG_USE_ARCH_MEMSET
4518 If these options are used a optimized version of memcpy/memset will
4519 be used if available. These functions may be faster under some
4520 conditions but may increase the binary size.
4522 - CONFIG_X86_RESET_VECTOR
4523 If defined, the x86 reset vector code is included. This is not
4524 needed when U-Boot is running from Coreboot.
4527 Defines the MPU clock speed (in MHz).
4529 NOTE : currently only supported on AM335x platforms.
4531 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4532 Enables the RTC32K OSC on AM33xx based plattforms
4534 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4535 Option to disable subpage write in NAND driver
4536 driver that uses this:
4537 drivers/mtd/nand/davinci_nand.c
4539 Freescale QE/FMAN Firmware Support:
4540 -----------------------------------
4542 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4543 loading of "firmware", which is encoded in the QE firmware binary format.
4544 This firmware often needs to be loaded during U-Boot booting, so macros
4545 are used to identify the storage device (NOR flash, SPI, etc) and the address
4548 - CONFIG_SYS_FMAN_FW_ADDR
4549 The address in the storage device where the FMAN microcode is located. The
4550 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4553 - CONFIG_SYS_QE_FW_ADDR
4554 The address in the storage device where the QE microcode is located. The
4555 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4558 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4559 The maximum possible size of the firmware. The firmware binary format
4560 has a field that specifies the actual size of the firmware, but it
4561 might not be possible to read any part of the firmware unless some
4562 local storage is allocated to hold the entire firmware first.
4564 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4565 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4566 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4567 virtual address in NOR flash.
4569 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4570 Specifies that QE/FMAN firmware is located in NAND flash.
4571 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4573 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4574 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4575 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4577 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4578 Specifies that QE/FMAN firmware is located on the primary SPI
4579 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4581 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4582 Specifies that QE/FMAN firmware is located in the remote (master)
4583 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4584 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4585 window->master inbound window->master LAW->the ucode address in
4586 master's memory space.
4588 Building the Software:
4589 ======================
4591 Building U-Boot has been tested in several native build environments
4592 and in many different cross environments. Of course we cannot support
4593 all possibly existing versions of cross development tools in all
4594 (potentially obsolete) versions. In case of tool chain problems we
4595 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4596 which is extensively used to build and test U-Boot.
4598 If you are not using a native environment, it is assumed that you
4599 have GNU cross compiling tools available in your path. In this case,
4600 you must set the environment variable CROSS_COMPILE in your shell.
4601 Note that no changes to the Makefile or any other source files are
4602 necessary. For example using the ELDK on a 4xx CPU, please enter:
4604 $ CROSS_COMPILE=ppc_4xx-
4605 $ export CROSS_COMPILE
4607 Note: If you wish to generate Windows versions of the utilities in
4608 the tools directory you can use the MinGW toolchain
4609 (http://www.mingw.org). Set your HOST tools to the MinGW
4610 toolchain and execute 'make tools'. For example:
4612 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4614 Binaries such as tools/mkimage.exe will be created which can
4615 be executed on computers running Windows.
4617 U-Boot is intended to be simple to build. After installing the
4618 sources you must configure U-Boot for one specific board type. This
4623 where "NAME_config" is the name of one of the existing configu-
4624 rations; see boards.cfg for supported names.
4626 Note: for some board special configuration names may exist; check if
4627 additional information is available from the board vendor; for
4628 instance, the TQM823L systems are available without (standard)
4629 or with LCD support. You can select such additional "features"
4630 when choosing the configuration, i. e.
4633 - will configure for a plain TQM823L, i. e. no LCD support
4635 make TQM823L_LCD_config
4636 - will configure for a TQM823L with U-Boot console on LCD
4641 Finally, type "make all", and you should get some working U-Boot
4642 images ready for download to / installation on your system:
4644 - "u-boot.bin" is a raw binary image
4645 - "u-boot" is an image in ELF binary format
4646 - "u-boot.srec" is in Motorola S-Record format
4648 By default the build is performed locally and the objects are saved
4649 in the source directory. One of the two methods can be used to change
4650 this behavior and build U-Boot to some external directory:
4652 1. Add O= to the make command line invocations:
4654 make O=/tmp/build distclean
4655 make O=/tmp/build NAME_config
4656 make O=/tmp/build all
4658 2. Set environment variable BUILD_DIR to point to the desired location:
4660 export BUILD_DIR=/tmp/build
4665 Note that the command line "O=" setting overrides the BUILD_DIR environment
4669 Please be aware that the Makefiles assume you are using GNU make, so
4670 for instance on NetBSD you might need to use "gmake" instead of
4674 If the system board that you have is not listed, then you will need
4675 to port U-Boot to your hardware platform. To do this, follow these
4678 1. Add a new configuration option for your board to the toplevel
4679 "boards.cfg" file, using the existing entries as examples.
4680 Follow the instructions there to keep the boards in order.
4681 2. Create a new directory to hold your board specific code. Add any
4682 files you need. In your board directory, you will need at least
4683 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4684 3. Create a new configuration file "include/configs/<board>.h" for
4686 3. If you're porting U-Boot to a new CPU, then also create a new
4687 directory to hold your CPU specific code. Add any files you need.
4688 4. Run "make <board>_config" with your new name.
4689 5. Type "make", and you should get a working "u-boot.srec" file
4690 to be installed on your target system.
4691 6. Debug and solve any problems that might arise.
4692 [Of course, this last step is much harder than it sounds.]
4695 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4696 ==============================================================
4698 If you have modified U-Boot sources (for instance added a new board
4699 or support for new devices, a new CPU, etc.) you are expected to
4700 provide feedback to the other developers. The feedback normally takes
4701 the form of a "patch", i. e. a context diff against a certain (latest
4702 official or latest in the git repository) version of U-Boot sources.
4704 But before you submit such a patch, please verify that your modifi-
4705 cation did not break existing code. At least make sure that *ALL* of
4706 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4707 just run the "MAKEALL" script, which will configure and build U-Boot
4708 for ALL supported system. Be warned, this will take a while. You can
4709 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4710 environment variable to the script, i. e. to use the ELDK cross tools
4713 CROSS_COMPILE=ppc_8xx- MAKEALL
4715 or to build on a native PowerPC system you can type
4717 CROSS_COMPILE=' ' MAKEALL
4719 When using the MAKEALL script, the default behaviour is to build
4720 U-Boot in the source directory. This location can be changed by
4721 setting the BUILD_DIR environment variable. Also, for each target
4722 built, the MAKEALL script saves two log files (<target>.ERR and
4723 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4724 location can be changed by setting the MAKEALL_LOGDIR environment
4725 variable. For example:
4727 export BUILD_DIR=/tmp/build
4728 export MAKEALL_LOGDIR=/tmp/log
4729 CROSS_COMPILE=ppc_8xx- MAKEALL
4731 With the above settings build objects are saved in the /tmp/build,
4732 log files are saved in the /tmp/log and the source tree remains clean
4733 during the whole build process.
4736 See also "U-Boot Porting Guide" below.
4739 Monitor Commands - Overview:
4740 ============================
4742 go - start application at address 'addr'
4743 run - run commands in an environment variable
4744 bootm - boot application image from memory
4745 bootp - boot image via network using BootP/TFTP protocol
4746 bootz - boot zImage from memory
4747 tftpboot- boot image via network using TFTP protocol
4748 and env variables "ipaddr" and "serverip"
4749 (and eventually "gatewayip")
4750 tftpput - upload a file via network using TFTP protocol
4751 rarpboot- boot image via network using RARP/TFTP protocol
4752 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4753 loads - load S-Record file over serial line
4754 loadb - load binary file over serial line (kermit mode)
4756 mm - memory modify (auto-incrementing)
4757 nm - memory modify (constant address)
4758 mw - memory write (fill)
4760 cmp - memory compare
4761 crc32 - checksum calculation
4762 i2c - I2C sub-system
4763 sspi - SPI utility commands
4764 base - print or set address offset
4765 printenv- print environment variables
4766 setenv - set environment variables
4767 saveenv - save environment variables to persistent storage
4768 protect - enable or disable FLASH write protection
4769 erase - erase FLASH memory
4770 flinfo - print FLASH memory information
4771 nand - NAND memory operations (see doc/README.nand)
4772 bdinfo - print Board Info structure
4773 iminfo - print header information for application image
4774 coninfo - print console devices and informations
4775 ide - IDE sub-system
4776 loop - infinite loop on address range
4777 loopw - infinite write loop on address range
4778 mtest - simple RAM test
4779 icache - enable or disable instruction cache
4780 dcache - enable or disable data cache
4781 reset - Perform RESET of the CPU
4782 echo - echo args to console
4783 version - print monitor version
4784 help - print online help
4785 ? - alias for 'help'
4788 Monitor Commands - Detailed Description:
4789 ========================================
4793 For now: just type "help <command>".
4796 Environment Variables:
4797 ======================
4799 U-Boot supports user configuration using Environment Variables which
4800 can be made persistent by saving to Flash memory.
4802 Environment Variables are set using "setenv", printed using
4803 "printenv", and saved to Flash using "saveenv". Using "setenv"
4804 without a value can be used to delete a variable from the
4805 environment. As long as you don't save the environment you are
4806 working with an in-memory copy. In case the Flash area containing the
4807 environment is erased by accident, a default environment is provided.
4809 Some configuration options can be set using Environment Variables.
4811 List of environment variables (most likely not complete):
4813 baudrate - see CONFIG_BAUDRATE
4815 bootdelay - see CONFIG_BOOTDELAY
4817 bootcmd - see CONFIG_BOOTCOMMAND
4819 bootargs - Boot arguments when booting an RTOS image
4821 bootfile - Name of the image to load with TFTP
4823 bootm_low - Memory range available for image processing in the bootm
4824 command can be restricted. This variable is given as
4825 a hexadecimal number and defines lowest address allowed
4826 for use by the bootm command. See also "bootm_size"
4827 environment variable. Address defined by "bootm_low" is
4828 also the base of the initial memory mapping for the Linux
4829 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4832 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4833 This variable is given as a hexadecimal number and it
4834 defines the size of the memory region starting at base
4835 address bootm_low that is accessible by the Linux kernel
4836 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4837 as the default value if it is defined, and bootm_size is
4840 bootm_size - Memory range available for image processing in the bootm
4841 command can be restricted. This variable is given as
4842 a hexadecimal number and defines the size of the region
4843 allowed for use by the bootm command. See also "bootm_low"
4844 environment variable.
4846 updatefile - Location of the software update file on a TFTP server, used
4847 by the automatic software update feature. Please refer to
4848 documentation in doc/README.update for more details.
4850 autoload - if set to "no" (any string beginning with 'n'),
4851 "bootp" will just load perform a lookup of the
4852 configuration from the BOOTP server, but not try to
4853 load any image using TFTP
4855 autostart - if set to "yes", an image loaded using the "bootp",
4856 "rarpboot", "tftpboot" or "diskboot" commands will
4857 be automatically started (by internally calling
4860 If set to "no", a standalone image passed to the
4861 "bootm" command will be copied to the load address
4862 (and eventually uncompressed), but NOT be started.
4863 This can be used to load and uncompress arbitrary
4866 fdt_high - if set this restricts the maximum address that the
4867 flattened device tree will be copied into upon boot.
4868 For example, if you have a system with 1 GB memory
4869 at physical address 0x10000000, while Linux kernel
4870 only recognizes the first 704 MB as low memory, you
4871 may need to set fdt_high as 0x3C000000 to have the
4872 device tree blob be copied to the maximum address
4873 of the 704 MB low memory, so that Linux kernel can
4874 access it during the boot procedure.
4876 If this is set to the special value 0xFFFFFFFF then
4877 the fdt will not be copied at all on boot. For this
4878 to work it must reside in writable memory, have
4879 sufficient padding on the end of it for u-boot to
4880 add the information it needs into it, and the memory
4881 must be accessible by the kernel.
4883 fdtcontroladdr- if set this is the address of the control flattened
4884 device tree used by U-Boot when CONFIG_OF_CONTROL is
4887 i2cfast - (PPC405GP|PPC405EP only)
4888 if set to 'y' configures Linux I2C driver for fast
4889 mode (400kHZ). This environment variable is used in
4890 initialization code. So, for changes to be effective
4891 it must be saved and board must be reset.
4893 initrd_high - restrict positioning of initrd images:
4894 If this variable is not set, initrd images will be
4895 copied to the highest possible address in RAM; this
4896 is usually what you want since it allows for
4897 maximum initrd size. If for some reason you want to
4898 make sure that the initrd image is loaded below the
4899 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4900 variable to a value of "no" or "off" or "0".
4901 Alternatively, you can set it to a maximum upper
4902 address to use (U-Boot will still check that it
4903 does not overwrite the U-Boot stack and data).
4905 For instance, when you have a system with 16 MB
4906 RAM, and want to reserve 4 MB from use by Linux,
4907 you can do this by adding "mem=12M" to the value of
4908 the "bootargs" variable. However, now you must make
4909 sure that the initrd image is placed in the first
4910 12 MB as well - this can be done with
4912 setenv initrd_high 00c00000
4914 If you set initrd_high to 0xFFFFFFFF, this is an
4915 indication to U-Boot that all addresses are legal
4916 for the Linux kernel, including addresses in flash
4917 memory. In this case U-Boot will NOT COPY the
4918 ramdisk at all. This may be useful to reduce the
4919 boot time on your system, but requires that this
4920 feature is supported by your Linux kernel.
4922 ipaddr - IP address; needed for tftpboot command
4924 loadaddr - Default load address for commands like "bootp",
4925 "rarpboot", "tftpboot", "loadb" or "diskboot"
4927 loads_echo - see CONFIG_LOADS_ECHO
4929 serverip - TFTP server IP address; needed for tftpboot command
4931 bootretry - see CONFIG_BOOT_RETRY_TIME
4933 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4935 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4937 ethprime - controls which interface is used first.
4939 ethact - controls which interface is currently active.
4940 For example you can do the following
4942 => setenv ethact FEC
4943 => ping 192.168.0.1 # traffic sent on FEC
4944 => setenv ethact SCC
4945 => ping 10.0.0.1 # traffic sent on SCC
4947 ethrotate - When set to "no" U-Boot does not go through all
4948 available network interfaces.
4949 It just stays at the currently selected interface.
4951 netretry - When set to "no" each network operation will
4952 either succeed or fail without retrying.
4953 When set to "once" the network operation will
4954 fail when all the available network interfaces
4955 are tried once without success.
4956 Useful on scripts which control the retry operation
4959 npe_ucode - set load address for the NPE microcode
4961 silent_linux - If set then linux will be told to boot silently, by
4962 changing the console to be empty. If "yes" it will be
4963 made silent. If "no" it will not be made silent. If
4964 unset, then it will be made silent if the U-Boot console
4967 tftpsrcport - If this is set, the value is used for TFTP's
4970 tftpdstport - If this is set, the value is used for TFTP's UDP
4971 destination port instead of the Well Know Port 69.
4973 tftpblocksize - Block size to use for TFTP transfers; if not set,
4974 we use the TFTP server's default block size
4976 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4977 seconds, minimum value is 1000 = 1 second). Defines
4978 when a packet is considered to be lost so it has to
4979 be retransmitted. The default is 5000 = 5 seconds.
4980 Lowering this value may make downloads succeed
4981 faster in networks with high packet loss rates or
4982 with unreliable TFTP servers.
4984 vlan - When set to a value < 4095 the traffic over
4985 Ethernet is encapsulated/received over 802.1q
4988 The following image location variables contain the location of images
4989 used in booting. The "Image" column gives the role of the image and is
4990 not an environment variable name. The other columns are environment
4991 variable names. "File Name" gives the name of the file on a TFTP
4992 server, "RAM Address" gives the location in RAM the image will be
4993 loaded to, and "Flash Location" gives the image's address in NOR
4994 flash or offset in NAND flash.
4996 *Note* - these variables don't have to be defined for all boards, some
4997 boards currenlty use other variables for these purposes, and some
4998 boards use these variables for other purposes.
5000 Image File Name RAM Address Flash Location
5001 ----- --------- ----------- --------------
5002 u-boot u-boot u-boot_addr_r u-boot_addr
5003 Linux kernel bootfile kernel_addr_r kernel_addr
5004 device tree blob fdtfile fdt_addr_r fdt_addr
5005 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5007 The following environment variables may be used and automatically
5008 updated by the network boot commands ("bootp" and "rarpboot"),
5009 depending the information provided by your boot server:
5011 bootfile - see above
5012 dnsip - IP address of your Domain Name Server
5013 dnsip2 - IP address of your secondary Domain Name Server
5014 gatewayip - IP address of the Gateway (Router) to use
5015 hostname - Target hostname
5017 netmask - Subnet Mask
5018 rootpath - Pathname of the root filesystem on the NFS server
5019 serverip - see above
5022 There are two special Environment Variables:
5024 serial# - contains hardware identification information such
5025 as type string and/or serial number
5026 ethaddr - Ethernet address
5028 These variables can be set only once (usually during manufacturing of
5029 the board). U-Boot refuses to delete or overwrite these variables
5030 once they have been set once.
5033 Further special Environment Variables:
5035 ver - Contains the U-Boot version string as printed
5036 with the "version" command. This variable is
5037 readonly (see CONFIG_VERSION_VARIABLE).
5040 Please note that changes to some configuration parameters may take
5041 only effect after the next boot (yes, that's just like Windoze :-).
5044 Callback functions for environment variables:
5045 ---------------------------------------------
5047 For some environment variables, the behavior of u-boot needs to change
5048 when their values are changed. This functionailty allows functions to
5049 be associated with arbitrary variables. On creation, overwrite, or
5050 deletion, the callback will provide the opportunity for some side
5051 effect to happen or for the change to be rejected.
5053 The callbacks are named and associated with a function using the
5054 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5056 These callbacks are associated with variables in one of two ways. The
5057 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5058 in the board configuration to a string that defines a list of
5059 associations. The list must be in the following format:
5061 entry = variable_name[:callback_name]
5064 If the callback name is not specified, then the callback is deleted.
5065 Spaces are also allowed anywhere in the list.
5067 Callbacks can also be associated by defining the ".callbacks" variable
5068 with the same list format above. Any association in ".callbacks" will
5069 override any association in the static list. You can define
5070 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5071 ".callbacks" envirnoment variable in the default or embedded environment.
5074 Command Line Parsing:
5075 =====================
5077 There are two different command line parsers available with U-Boot:
5078 the old "simple" one, and the much more powerful "hush" shell:
5080 Old, simple command line parser:
5081 --------------------------------
5083 - supports environment variables (through setenv / saveenv commands)
5084 - several commands on one line, separated by ';'
5085 - variable substitution using "... ${name} ..." syntax
5086 - special characters ('$', ';') can be escaped by prefixing with '\',
5088 setenv bootcmd bootm \${address}
5089 - You can also escape text by enclosing in single apostrophes, for example:
5090 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5095 - similar to Bourne shell, with control structures like
5096 if...then...else...fi, for...do...done; while...do...done,
5097 until...do...done, ...
5098 - supports environment ("global") variables (through setenv / saveenv
5099 commands) and local shell variables (through standard shell syntax
5100 "name=value"); only environment variables can be used with "run"
5106 (1) If a command line (or an environment variable executed by a "run"
5107 command) contains several commands separated by semicolon, and
5108 one of these commands fails, then the remaining commands will be
5111 (2) If you execute several variables with one call to run (i. e.
5112 calling run with a list of variables as arguments), any failing
5113 command will cause "run" to terminate, i. e. the remaining
5114 variables are not executed.
5116 Note for Redundant Ethernet Interfaces:
5117 =======================================
5119 Some boards come with redundant Ethernet interfaces; U-Boot supports
5120 such configurations and is capable of automatic selection of a
5121 "working" interface when needed. MAC assignment works as follows:
5123 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5124 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5125 "eth1addr" (=>eth1), "eth2addr", ...
5127 If the network interface stores some valid MAC address (for instance
5128 in SROM), this is used as default address if there is NO correspon-
5129 ding setting in the environment; if the corresponding environment
5130 variable is set, this overrides the settings in the card; that means:
5132 o If the SROM has a valid MAC address, and there is no address in the
5133 environment, the SROM's address is used.
5135 o If there is no valid address in the SROM, and a definition in the
5136 environment exists, then the value from the environment variable is
5139 o If both the SROM and the environment contain a MAC address, and
5140 both addresses are the same, this MAC address is used.
5142 o If both the SROM and the environment contain a MAC address, and the
5143 addresses differ, the value from the environment is used and a
5146 o If neither SROM nor the environment contain a MAC address, an error
5149 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5150 will be programmed into hardware as part of the initialization process. This
5151 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5152 The naming convention is as follows:
5153 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5158 U-Boot is capable of booting (and performing other auxiliary operations on)
5159 images in two formats:
5161 New uImage format (FIT)
5162 -----------------------
5164 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5165 to Flattened Device Tree). It allows the use of images with multiple
5166 components (several kernels, ramdisks, etc.), with contents protected by
5167 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5173 Old image format is based on binary files which can be basically anything,
5174 preceded by a special header; see the definitions in include/image.h for
5175 details; basically, the header defines the following image properties:
5177 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5178 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5179 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5180 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5182 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5183 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5184 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5185 * Compression Type (uncompressed, gzip, bzip2)
5191 The header is marked by a special Magic Number, and both the header
5192 and the data portions of the image are secured against corruption by
5199 Although U-Boot should support any OS or standalone application
5200 easily, the main focus has always been on Linux during the design of
5203 U-Boot includes many features that so far have been part of some
5204 special "boot loader" code within the Linux kernel. Also, any
5205 "initrd" images to be used are no longer part of one big Linux image;
5206 instead, kernel and "initrd" are separate images. This implementation
5207 serves several purposes:
5209 - the same features can be used for other OS or standalone
5210 applications (for instance: using compressed images to reduce the
5211 Flash memory footprint)
5213 - it becomes much easier to port new Linux kernel versions because
5214 lots of low-level, hardware dependent stuff are done by U-Boot
5216 - the same Linux kernel image can now be used with different "initrd"
5217 images; of course this also means that different kernel images can
5218 be run with the same "initrd". This makes testing easier (you don't
5219 have to build a new "zImage.initrd" Linux image when you just
5220 change a file in your "initrd"). Also, a field-upgrade of the
5221 software is easier now.
5227 Porting Linux to U-Boot based systems:
5228 ---------------------------------------
5230 U-Boot cannot save you from doing all the necessary modifications to
5231 configure the Linux device drivers for use with your target hardware
5232 (no, we don't intend to provide a full virtual machine interface to
5235 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5237 Just make sure your machine specific header file (for instance
5238 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5239 Information structure as we define in include/asm-<arch>/u-boot.h,
5240 and make sure that your definition of IMAP_ADDR uses the same value
5241 as your U-Boot configuration in CONFIG_SYS_IMMR.
5244 Configuring the Linux kernel:
5245 -----------------------------
5247 No specific requirements for U-Boot. Make sure you have some root
5248 device (initial ramdisk, NFS) for your target system.
5251 Building a Linux Image:
5252 -----------------------
5254 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5255 not used. If you use recent kernel source, a new build target
5256 "uImage" will exist which automatically builds an image usable by
5257 U-Boot. Most older kernels also have support for a "pImage" target,
5258 which was introduced for our predecessor project PPCBoot and uses a
5259 100% compatible format.
5268 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5269 encapsulate a compressed Linux kernel image with header information,
5270 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5272 * build a standard "vmlinux" kernel image (in ELF binary format):
5274 * convert the kernel into a raw binary image:
5276 ${CROSS_COMPILE}-objcopy -O binary \
5277 -R .note -R .comment \
5278 -S vmlinux linux.bin
5280 * compress the binary image:
5284 * package compressed binary image for U-Boot:
5286 mkimage -A ppc -O linux -T kernel -C gzip \
5287 -a 0 -e 0 -n "Linux Kernel Image" \
5288 -d linux.bin.gz uImage
5291 The "mkimage" tool can also be used to create ramdisk images for use
5292 with U-Boot, either separated from the Linux kernel image, or
5293 combined into one file. "mkimage" encapsulates the images with a 64
5294 byte header containing information about target architecture,
5295 operating system, image type, compression method, entry points, time
5296 stamp, CRC32 checksums, etc.
5298 "mkimage" can be called in two ways: to verify existing images and
5299 print the header information, or to build new images.
5301 In the first form (with "-l" option) mkimage lists the information
5302 contained in the header of an existing U-Boot image; this includes
5303 checksum verification:
5305 tools/mkimage -l image
5306 -l ==> list image header information
5308 The second form (with "-d" option) is used to build a U-Boot image
5309 from a "data file" which is used as image payload:
5311 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5312 -n name -d data_file image
5313 -A ==> set architecture to 'arch'
5314 -O ==> set operating system to 'os'
5315 -T ==> set image type to 'type'
5316 -C ==> set compression type 'comp'
5317 -a ==> set load address to 'addr' (hex)
5318 -e ==> set entry point to 'ep' (hex)
5319 -n ==> set image name to 'name'
5320 -d ==> use image data from 'datafile'
5322 Right now, all Linux kernels for PowerPC systems use the same load
5323 address (0x00000000), but the entry point address depends on the
5326 - 2.2.x kernels have the entry point at 0x0000000C,
5327 - 2.3.x and later kernels have the entry point at 0x00000000.
5329 So a typical call to build a U-Boot image would read:
5331 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5332 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5333 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5334 > examples/uImage.TQM850L
5335 Image Name: 2.4.4 kernel for TQM850L
5336 Created: Wed Jul 19 02:34:59 2000
5337 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5338 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5339 Load Address: 0x00000000
5340 Entry Point: 0x00000000
5342 To verify the contents of the image (or check for corruption):
5344 -> tools/mkimage -l examples/uImage.TQM850L
5345 Image Name: 2.4.4 kernel for TQM850L
5346 Created: Wed Jul 19 02:34:59 2000
5347 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5348 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5349 Load Address: 0x00000000
5350 Entry Point: 0x00000000
5352 NOTE: for embedded systems where boot time is critical you can trade
5353 speed for memory and install an UNCOMPRESSED image instead: this
5354 needs more space in Flash, but boots much faster since it does not
5355 need to be uncompressed:
5357 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5358 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5359 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5360 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5361 > examples/uImage.TQM850L-uncompressed
5362 Image Name: 2.4.4 kernel for TQM850L
5363 Created: Wed Jul 19 02:34:59 2000
5364 Image Type: PowerPC Linux Kernel Image (uncompressed)
5365 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5366 Load Address: 0x00000000
5367 Entry Point: 0x00000000
5370 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5371 when your kernel is intended to use an initial ramdisk:
5373 -> tools/mkimage -n 'Simple Ramdisk Image' \
5374 > -A ppc -O linux -T ramdisk -C gzip \
5375 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5376 Image Name: Simple Ramdisk Image
5377 Created: Wed Jan 12 14:01:50 2000
5378 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5379 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5380 Load Address: 0x00000000
5381 Entry Point: 0x00000000
5383 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5384 option performs the converse operation of the mkimage's second form (the "-d"
5385 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5388 tools/dumpimage -i image -p position data_file
5389 -i ==> extract from the 'image' a specific 'data_file', \
5390 indexed by 'position'
5393 Installing a Linux Image:
5394 -------------------------
5396 To downloading a U-Boot image over the serial (console) interface,
5397 you must convert the image to S-Record format:
5399 objcopy -I binary -O srec examples/image examples/image.srec
5401 The 'objcopy' does not understand the information in the U-Boot
5402 image header, so the resulting S-Record file will be relative to
5403 address 0x00000000. To load it to a given address, you need to
5404 specify the target address as 'offset' parameter with the 'loads'
5407 Example: install the image to address 0x40100000 (which on the
5408 TQM8xxL is in the first Flash bank):
5410 => erase 40100000 401FFFFF
5416 ## Ready for S-Record download ...
5417 ~>examples/image.srec
5418 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5420 15989 15990 15991 15992
5421 [file transfer complete]
5423 ## Start Addr = 0x00000000
5426 You can check the success of the download using the 'iminfo' command;
5427 this includes a checksum verification so you can be sure no data
5428 corruption happened:
5432 ## Checking Image at 40100000 ...
5433 Image Name: 2.2.13 for initrd on TQM850L
5434 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5435 Data Size: 335725 Bytes = 327 kB = 0 MB
5436 Load Address: 00000000
5437 Entry Point: 0000000c
5438 Verifying Checksum ... OK
5444 The "bootm" command is used to boot an application that is stored in
5445 memory (RAM or Flash). In case of a Linux kernel image, the contents
5446 of the "bootargs" environment variable is passed to the kernel as
5447 parameters. You can check and modify this variable using the
5448 "printenv" and "setenv" commands:
5451 => printenv bootargs
5452 bootargs=root=/dev/ram
5454 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5456 => printenv bootargs
5457 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5460 ## Booting Linux kernel at 40020000 ...
5461 Image Name: 2.2.13 for NFS on TQM850L
5462 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5463 Data Size: 381681 Bytes = 372 kB = 0 MB
5464 Load Address: 00000000
5465 Entry Point: 0000000c
5466 Verifying Checksum ... OK
5467 Uncompressing Kernel Image ... OK
5468 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
5469 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5470 time_init: decrementer frequency = 187500000/60
5471 Calibrating delay loop... 49.77 BogoMIPS
5472 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5475 If you want to boot a Linux kernel with initial RAM disk, you pass
5476 the memory addresses of both the kernel and the initrd image (PPBCOOT
5477 format!) to the "bootm" command:
5479 => imi 40100000 40200000
5481 ## Checking Image at 40100000 ...
5482 Image Name: 2.2.13 for initrd on TQM850L
5483 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5484 Data Size: 335725 Bytes = 327 kB = 0 MB
5485 Load Address: 00000000
5486 Entry Point: 0000000c
5487 Verifying Checksum ... OK
5489 ## Checking Image at 40200000 ...
5490 Image Name: Simple Ramdisk Image
5491 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5492 Data Size: 566530 Bytes = 553 kB = 0 MB
5493 Load Address: 00000000
5494 Entry Point: 00000000
5495 Verifying Checksum ... OK
5497 => bootm 40100000 40200000
5498 ## Booting Linux kernel at 40100000 ...
5499 Image Name: 2.2.13 for initrd on TQM850L
5500 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5501 Data Size: 335725 Bytes = 327 kB = 0 MB
5502 Load Address: 00000000
5503 Entry Point: 0000000c
5504 Verifying Checksum ... OK
5505 Uncompressing Kernel Image ... OK
5506 ## Loading RAMDisk Image at 40200000 ...
5507 Image Name: Simple Ramdisk Image
5508 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5509 Data Size: 566530 Bytes = 553 kB = 0 MB
5510 Load Address: 00000000
5511 Entry Point: 00000000
5512 Verifying Checksum ... OK
5513 Loading Ramdisk ... OK
5514 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
5515 Boot arguments: root=/dev/ram
5516 time_init: decrementer frequency = 187500000/60
5517 Calibrating delay loop... 49.77 BogoMIPS
5519 RAMDISK: Compressed image found at block 0
5520 VFS: Mounted root (ext2 filesystem).
5524 Boot Linux and pass a flat device tree:
5527 First, U-Boot must be compiled with the appropriate defines. See the section
5528 titled "Linux Kernel Interface" above for a more in depth explanation. The
5529 following is an example of how to start a kernel and pass an updated
5535 oft=oftrees/mpc8540ads.dtb
5536 => tftp $oftaddr $oft
5537 Speed: 1000, full duplex
5539 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5540 Filename 'oftrees/mpc8540ads.dtb'.
5541 Load address: 0x300000
5544 Bytes transferred = 4106 (100a hex)
5545 => tftp $loadaddr $bootfile
5546 Speed: 1000, full duplex
5548 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5550 Load address: 0x200000
5551 Loading:############
5553 Bytes transferred = 1029407 (fb51f hex)
5558 => bootm $loadaddr - $oftaddr
5559 ## Booting image at 00200000 ...
5560 Image Name: Linux-2.6.17-dirty
5561 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5562 Data Size: 1029343 Bytes = 1005.2 kB
5563 Load Address: 00000000
5564 Entry Point: 00000000
5565 Verifying Checksum ... OK
5566 Uncompressing Kernel Image ... OK
5567 Booting using flat device tree at 0x300000
5568 Using MPC85xx ADS machine description
5569 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5573 More About U-Boot Image Types:
5574 ------------------------------
5576 U-Boot supports the following image types:
5578 "Standalone Programs" are directly runnable in the environment
5579 provided by U-Boot; it is expected that (if they behave
5580 well) you can continue to work in U-Boot after return from
5581 the Standalone Program.
5582 "OS Kernel Images" are usually images of some Embedded OS which
5583 will take over control completely. Usually these programs
5584 will install their own set of exception handlers, device
5585 drivers, set up the MMU, etc. - this means, that you cannot
5586 expect to re-enter U-Boot except by resetting the CPU.
5587 "RAMDisk Images" are more or less just data blocks, and their
5588 parameters (address, size) are passed to an OS kernel that is
5590 "Multi-File Images" contain several images, typically an OS
5591 (Linux) kernel image and one or more data images like
5592 RAMDisks. This construct is useful for instance when you want
5593 to boot over the network using BOOTP etc., where the boot
5594 server provides just a single image file, but you want to get
5595 for instance an OS kernel and a RAMDisk image.
5597 "Multi-File Images" start with a list of image sizes, each
5598 image size (in bytes) specified by an "uint32_t" in network
5599 byte order. This list is terminated by an "(uint32_t)0".
5600 Immediately after the terminating 0 follow the images, one by
5601 one, all aligned on "uint32_t" boundaries (size rounded up to
5602 a multiple of 4 bytes).
5604 "Firmware Images" are binary images containing firmware (like
5605 U-Boot or FPGA images) which usually will be programmed to
5608 "Script files" are command sequences that will be executed by
5609 U-Boot's command interpreter; this feature is especially
5610 useful when you configure U-Boot to use a real shell (hush)
5611 as command interpreter.
5613 Booting the Linux zImage:
5614 -------------------------
5616 On some platforms, it's possible to boot Linux zImage. This is done
5617 using the "bootz" command. The syntax of "bootz" command is the same
5618 as the syntax of "bootm" command.
5620 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5621 kernel with raw initrd images. The syntax is slightly different, the
5622 address of the initrd must be augmented by it's size, in the following
5623 format: "<initrd addres>:<initrd size>".
5629 One of the features of U-Boot is that you can dynamically load and
5630 run "standalone" applications, which can use some resources of
5631 U-Boot like console I/O functions or interrupt services.
5633 Two simple examples are included with the sources:
5638 'examples/hello_world.c' contains a small "Hello World" Demo
5639 application; it is automatically compiled when you build U-Boot.
5640 It's configured to run at address 0x00040004, so you can play with it
5644 ## Ready for S-Record download ...
5645 ~>examples/hello_world.srec
5646 1 2 3 4 5 6 7 8 9 10 11 ...
5647 [file transfer complete]
5649 ## Start Addr = 0x00040004
5651 => go 40004 Hello World! This is a test.
5652 ## Starting application at 0x00040004 ...
5663 Hit any key to exit ...
5665 ## Application terminated, rc = 0x0
5667 Another example, which demonstrates how to register a CPM interrupt
5668 handler with the U-Boot code, can be found in 'examples/timer.c'.
5669 Here, a CPM timer is set up to generate an interrupt every second.
5670 The interrupt service routine is trivial, just printing a '.'
5671 character, but this is just a demo program. The application can be
5672 controlled by the following keys:
5674 ? - print current values og the CPM Timer registers
5675 b - enable interrupts and start timer
5676 e - stop timer and disable interrupts
5677 q - quit application
5680 ## Ready for S-Record download ...
5681 ~>examples/timer.srec
5682 1 2 3 4 5 6 7 8 9 10 11 ...
5683 [file transfer complete]
5685 ## Start Addr = 0x00040004
5688 ## Starting application at 0x00040004 ...
5691 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5694 [q, b, e, ?] Set interval 1000000 us
5697 [q, b, e, ?] ........
5698 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5701 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5704 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5707 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5709 [q, b, e, ?] ...Stopping timer
5711 [q, b, e, ?] ## Application terminated, rc = 0x0
5717 Over time, many people have reported problems when trying to use the
5718 "minicom" terminal emulation program for serial download. I (wd)
5719 consider minicom to be broken, and recommend not to use it. Under
5720 Unix, I recommend to use C-Kermit for general purpose use (and
5721 especially for kermit binary protocol download ("loadb" command), and
5722 use "cu" for S-Record download ("loads" command). See
5723 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5724 for help with kermit.
5727 Nevertheless, if you absolutely want to use it try adding this
5728 configuration to your "File transfer protocols" section:
5730 Name Program Name U/D FullScr IO-Red. Multi
5731 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5732 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5738 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5739 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5741 Building requires a cross environment; it is known to work on
5742 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5743 need gmake since the Makefiles are not compatible with BSD make).
5744 Note that the cross-powerpc package does not install include files;
5745 attempting to build U-Boot will fail because <machine/ansi.h> is
5746 missing. This file has to be installed and patched manually:
5748 # cd /usr/pkg/cross/powerpc-netbsd/include
5750 # ln -s powerpc machine
5751 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5752 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5754 Native builds *don't* work due to incompatibilities between native
5755 and U-Boot include files.
5757 Booting assumes that (the first part of) the image booted is a
5758 stage-2 loader which in turn loads and then invokes the kernel
5759 proper. Loader sources will eventually appear in the NetBSD source
5760 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5761 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5764 Implementation Internals:
5765 =========================
5767 The following is not intended to be a complete description of every
5768 implementation detail. However, it should help to understand the
5769 inner workings of U-Boot and make it easier to port it to custom
5773 Initial Stack, Global Data:
5774 ---------------------------
5776 The implementation of U-Boot is complicated by the fact that U-Boot
5777 starts running out of ROM (flash memory), usually without access to
5778 system RAM (because the memory controller is not initialized yet).
5779 This means that we don't have writable Data or BSS segments, and BSS
5780 is not initialized as zero. To be able to get a C environment working
5781 at all, we have to allocate at least a minimal stack. Implementation
5782 options for this are defined and restricted by the CPU used: Some CPU
5783 models provide on-chip memory (like the IMMR area on MPC8xx and
5784 MPC826x processors), on others (parts of) the data cache can be
5785 locked as (mis-) used as memory, etc.
5787 Chris Hallinan posted a good summary of these issues to the
5788 U-Boot mailing list:
5790 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5791 From: "Chris Hallinan" <clh@net1plus.com>
5792 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5795 Correct me if I'm wrong, folks, but the way I understand it
5796 is this: Using DCACHE as initial RAM for Stack, etc, does not
5797 require any physical RAM backing up the cache. The cleverness
5798 is that the cache is being used as a temporary supply of
5799 necessary storage before the SDRAM controller is setup. It's
5800 beyond the scope of this list to explain the details, but you
5801 can see how this works by studying the cache architecture and
5802 operation in the architecture and processor-specific manuals.
5804 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5805 is another option for the system designer to use as an
5806 initial stack/RAM area prior to SDRAM being available. Either
5807 option should work for you. Using CS 4 should be fine if your
5808 board designers haven't used it for something that would
5809 cause you grief during the initial boot! It is frequently not
5812 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5813 with your processor/board/system design. The default value
5814 you will find in any recent u-boot distribution in
5815 walnut.h should work for you. I'd set it to a value larger
5816 than your SDRAM module. If you have a 64MB SDRAM module, set
5817 it above 400_0000. Just make sure your board has no resources
5818 that are supposed to respond to that address! That code in
5819 start.S has been around a while and should work as is when
5820 you get the config right.
5825 It is essential to remember this, since it has some impact on the C
5826 code for the initialization procedures:
5828 * Initialized global data (data segment) is read-only. Do not attempt
5831 * Do not use any uninitialized global data (or implicitely initialized
5832 as zero data - BSS segment) at all - this is undefined, initiali-
5833 zation is performed later (when relocating to RAM).
5835 * Stack space is very limited. Avoid big data buffers or things like
5838 Having only the stack as writable memory limits means we cannot use
5839 normal global data to share information beween the code. But it
5840 turned out that the implementation of U-Boot can be greatly
5841 simplified by making a global data structure (gd_t) available to all
5842 functions. We could pass a pointer to this data as argument to _all_
5843 functions, but this would bloat the code. Instead we use a feature of
5844 the GCC compiler (Global Register Variables) to share the data: we
5845 place a pointer (gd) to the global data into a register which we
5846 reserve for this purpose.
5848 When choosing a register for such a purpose we are restricted by the
5849 relevant (E)ABI specifications for the current architecture, and by
5850 GCC's implementation.
5852 For PowerPC, the following registers have specific use:
5854 R2: reserved for system use
5855 R3-R4: parameter passing and return values
5856 R5-R10: parameter passing
5857 R13: small data area pointer
5861 (U-Boot also uses R12 as internal GOT pointer. r12
5862 is a volatile register so r12 needs to be reset when
5863 going back and forth between asm and C)
5865 ==> U-Boot will use R2 to hold a pointer to the global data
5867 Note: on PPC, we could use a static initializer (since the
5868 address of the global data structure is known at compile time),
5869 but it turned out that reserving a register results in somewhat
5870 smaller code - although the code savings are not that big (on
5871 average for all boards 752 bytes for the whole U-Boot image,
5872 624 text + 127 data).
5874 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5875 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5877 ==> U-Boot will use P3 to hold a pointer to the global data
5879 On ARM, the following registers are used:
5881 R0: function argument word/integer result
5882 R1-R3: function argument word
5883 R9: platform specific
5884 R10: stack limit (used only if stack checking is enabled)
5885 R11: argument (frame) pointer
5886 R12: temporary workspace
5889 R15: program counter
5891 ==> U-Boot will use R9 to hold a pointer to the global data
5893 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5895 On Nios II, the ABI is documented here:
5896 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5898 ==> U-Boot will use gp to hold a pointer to the global data
5900 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5901 to access small data sections, so gp is free.
5903 On NDS32, the following registers are used:
5905 R0-R1: argument/return
5907 R15: temporary register for assembler
5908 R16: trampoline register
5909 R28: frame pointer (FP)
5910 R29: global pointer (GP)
5911 R30: link register (LP)
5912 R31: stack pointer (SP)
5913 PC: program counter (PC)
5915 ==> U-Boot will use R10 to hold a pointer to the global data
5917 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5918 or current versions of GCC may "optimize" the code too much.
5923 U-Boot runs in system state and uses physical addresses, i.e. the
5924 MMU is not used either for address mapping nor for memory protection.
5926 The available memory is mapped to fixed addresses using the memory
5927 controller. In this process, a contiguous block is formed for each
5928 memory type (Flash, SDRAM, SRAM), even when it consists of several
5929 physical memory banks.
5931 U-Boot is installed in the first 128 kB of the first Flash bank (on
5932 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5933 booting and sizing and initializing DRAM, the code relocates itself
5934 to the upper end of DRAM. Immediately below the U-Boot code some
5935 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5936 configuration setting]. Below that, a structure with global Board
5937 Info data is placed, followed by the stack (growing downward).
5939 Additionally, some exception handler code is copied to the low 8 kB
5940 of DRAM (0x00000000 ... 0x00001FFF).
5942 So a typical memory configuration with 16 MB of DRAM could look like
5945 0x0000 0000 Exception Vector code
5948 0x0000 2000 Free for Application Use
5954 0x00FB FF20 Monitor Stack (Growing downward)
5955 0x00FB FFAC Board Info Data and permanent copy of global data
5956 0x00FC 0000 Malloc Arena
5959 0x00FE 0000 RAM Copy of Monitor Code
5960 ... eventually: LCD or video framebuffer
5961 ... eventually: pRAM (Protected RAM - unchanged by reset)
5962 0x00FF FFFF [End of RAM]
5965 System Initialization:
5966 ----------------------
5968 In the reset configuration, U-Boot starts at the reset entry point
5969 (on most PowerPC systems at address 0x00000100). Because of the reset
5970 configuration for CS0# this is a mirror of the onboard Flash memory.
5971 To be able to re-map memory U-Boot then jumps to its link address.
5972 To be able to implement the initialization code in C, a (small!)
5973 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5974 which provide such a feature like MPC8xx or MPC8260), or in a locked
5975 part of the data cache. After that, U-Boot initializes the CPU core,
5976 the caches and the SIU.
5978 Next, all (potentially) available memory banks are mapped using a
5979 preliminary mapping. For example, we put them on 512 MB boundaries
5980 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5981 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5982 programmed for SDRAM access. Using the temporary configuration, a
5983 simple memory test is run that determines the size of the SDRAM
5986 When there is more than one SDRAM bank, and the banks are of
5987 different size, the largest is mapped first. For equal size, the first
5988 bank (CS2#) is mapped first. The first mapping is always for address
5989 0x00000000, with any additional banks following immediately to create
5990 contiguous memory starting from 0.
5992 Then, the monitor installs itself at the upper end of the SDRAM area
5993 and allocates memory for use by malloc() and for the global Board
5994 Info data; also, the exception vector code is copied to the low RAM
5995 pages, and the final stack is set up.
5997 Only after this relocation will you have a "normal" C environment;
5998 until that you are restricted in several ways, mostly because you are
5999 running from ROM, and because the code will have to be relocated to a
6003 U-Boot Porting Guide:
6004 ----------------------
6006 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6010 int main(int argc, char *argv[])
6012 sighandler_t no_more_time;
6014 signal(SIGALRM, no_more_time);
6015 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6017 if (available_money > available_manpower) {
6018 Pay consultant to port U-Boot;
6022 Download latest U-Boot source;
6024 Subscribe to u-boot mailing list;
6027 email("Hi, I am new to U-Boot, how do I get started?");
6030 Read the README file in the top level directory;
6031 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6032 Read applicable doc/*.README;
6033 Read the source, Luke;
6034 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6037 if (available_money > toLocalCurrency ($2500))
6040 Add a lot of aggravation and time;
6042 if (a similar board exists) { /* hopefully... */
6043 cp -a board/<similar> board/<myboard>
6044 cp include/configs/<similar>.h include/configs/<myboard>.h
6046 Create your own board support subdirectory;
6047 Create your own board include/configs/<myboard>.h file;
6049 Edit new board/<myboard> files
6050 Edit new include/configs/<myboard>.h
6055 Add / modify source code;
6059 email("Hi, I am having problems...");
6061 Send patch file to the U-Boot email list;
6062 if (reasonable critiques)
6063 Incorporate improvements from email list code review;
6065 Defend code as written;
6071 void no_more_time (int sig)
6080 All contributions to U-Boot should conform to the Linux kernel
6081 coding style; see the file "Documentation/CodingStyle" and the script
6082 "scripts/Lindent" in your Linux kernel source directory.
6084 Source files originating from a different project (for example the
6085 MTD subsystem) are generally exempt from these guidelines and are not
6086 reformated to ease subsequent migration to newer versions of those
6089 Please note that U-Boot is implemented in C (and to some small parts in
6090 Assembler); no C++ is used, so please do not use C++ style comments (//)
6093 Please also stick to the following formatting rules:
6094 - remove any trailing white space
6095 - use TAB characters for indentation and vertical alignment, not spaces
6096 - make sure NOT to use DOS '\r\n' line feeds
6097 - do not add more than 2 consecutive empty lines to source files
6098 - do not add trailing empty lines to source files
6100 Submissions which do not conform to the standards may be returned
6101 with a request to reformat the changes.
6107 Since the number of patches for U-Boot is growing, we need to
6108 establish some rules. Submissions which do not conform to these rules
6109 may be rejected, even when they contain important and valuable stuff.
6111 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6113 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6114 see http://lists.denx.de/mailman/listinfo/u-boot
6116 When you send a patch, please include the following information with
6119 * For bug fixes: a description of the bug and how your patch fixes
6120 this bug. Please try to include a way of demonstrating that the
6121 patch actually fixes something.
6123 * For new features: a description of the feature and your
6126 * A CHANGELOG entry as plaintext (separate from the patch)
6128 * For major contributions, your entry to the CREDITS file
6130 * When you add support for a new board, don't forget to add a
6131 maintainer e-mail address to the boards.cfg file, too.
6133 * If your patch adds new configuration options, don't forget to
6134 document these in the README file.
6136 * The patch itself. If you are using git (which is *strongly*
6137 recommended) you can easily generate the patch using the
6138 "git format-patch". If you then use "git send-email" to send it to
6139 the U-Boot mailing list, you will avoid most of the common problems
6140 with some other mail clients.
6142 If you cannot use git, use "diff -purN OLD NEW". If your version of
6143 diff does not support these options, then get the latest version of
6146 The current directory when running this command shall be the parent
6147 directory of the U-Boot source tree (i. e. please make sure that
6148 your patch includes sufficient directory information for the
6151 We prefer patches as plain text. MIME attachments are discouraged,
6152 and compressed attachments must not be used.
6154 * If one logical set of modifications affects or creates several
6155 files, all these changes shall be submitted in a SINGLE patch file.
6157 * Changesets that contain different, unrelated modifications shall be
6158 submitted as SEPARATE patches, one patch per changeset.
6163 * Before sending the patch, run the MAKEALL script on your patched
6164 source tree and make sure that no errors or warnings are reported
6165 for any of the boards.
6167 * Keep your modifications to the necessary minimum: A patch
6168 containing several unrelated changes or arbitrary reformats will be
6169 returned with a request to re-formatting / split it.
6171 * If you modify existing code, make sure that your new code does not
6172 add to the memory footprint of the code ;-) Small is beautiful!
6173 When adding new features, these should compile conditionally only
6174 (using #ifdef), and the resulting code with the new feature
6175 disabled must not need more memory than the old code without your
6178 * Remember that there is a size limit of 100 kB per message on the
6179 u-boot mailing list. Bigger patches will be moderated. If they are
6180 reasonable and not too big, they will be acknowledged. But patches
6181 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob