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 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Configuration Options:
277 ----------------------
279 Configuration depends on the combination of board and CPU type; all
280 such information is kept in a configuration file
281 "include/configs/<board_name>.h".
283 Example: For a TQM823L module, all configuration settings are in
284 "include/configs/TQM823L.h".
287 Many of the options are named exactly as the corresponding Linux
288 kernel configuration options. The intention is to make it easier to
289 build a config tool - later.
292 The following options need to be configured:
294 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
296 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
298 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
299 Define exactly one, e.g. CONFIG_ATSTK1002
301 - CPU Module Type: (if CONFIG_COGENT is defined)
302 Define exactly one of
304 --- FIXME --- not tested yet:
305 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
306 CONFIG_CMA287_23, CONFIG_CMA287_50
308 - Motherboard Type: (if CONFIG_COGENT is defined)
309 Define exactly one of
310 CONFIG_CMA101, CONFIG_CMA102
312 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
313 Define one or more of
316 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
317 Define one or more of
318 CONFIG_LCD_HEARTBEAT - update a character position on
319 the LCD display every second with
322 - Marvell Family Member
323 CONFIG_SYS_MVFS - define it if you want to enable
324 multiple fs option at one time
325 for marvell soc family
327 - 8xx CPU Options: (if using an MPC8xx CPU)
328 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
329 get_gclk_freq() cannot work
330 e.g. if there is no 32KHz
331 reference PIT/RTC clock
332 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
335 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
336 CONFIG_SYS_8xx_CPUCLK_MIN
337 CONFIG_SYS_8xx_CPUCLK_MAX
338 CONFIG_8xx_CPUCLK_DEFAULT
339 See doc/README.MPC866
341 CONFIG_SYS_MEASURE_CPUCLK
343 Define this to measure the actual CPU clock instead
344 of relying on the correctness of the configured
345 values. Mostly useful for board bringup to make sure
346 the PLL is locked at the intended frequency. Note
347 that this requires a (stable) reference clock (32 kHz
348 RTC clock or CONFIG_SYS_8XX_XIN)
350 CONFIG_SYS_DELAYED_ICACHE
352 Define this option if you want to enable the
353 ICache only when Code runs from RAM.
358 Specifies that the core is a 64-bit PowerPC implementation (implements
359 the "64" category of the Power ISA). This is necessary for ePAPR
360 compliance, among other possible reasons.
362 CONFIG_SYS_FSL_TBCLK_DIV
364 Defines the core time base clock divider ratio compared to the
365 system clock. On most PQ3 devices this is 8, on newer QorIQ
366 devices it can be 16 or 32. The ratio varies from SoC to Soc.
368 CONFIG_SYS_FSL_PCIE_COMPAT
370 Defines the string to utilize when trying to match PCIe device
371 tree nodes for the given platform.
373 CONFIG_SYS_PPC_E500_DEBUG_TLB
375 Enables a temporary TLB entry to be used during boot to work
376 around limitations in e500v1 and e500v2 external debugger
377 support. This reduces the portions of the boot code where
378 breakpoints and single stepping do not work. The value of this
379 symbol should be set to the TLB1 entry to be used for this
382 CONFIG_SYS_FSL_ERRATUM_A004510
384 Enables a workaround for erratum A004510. If set,
385 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
386 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
391 Defines one or two SoC revisions (low 8 bits of SVR)
392 for which the A004510 workaround should be applied.
394 The rest of SVR is either not relevant to the decision
395 of whether the erratum is present (e.g. p2040 versus
396 p2041) or is implied by the build target, which controls
397 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
399 See Freescale App Note 4493 for more information about
402 CONFIG_A003399_NOR_WORKAROUND
403 Enables a workaround for IFC erratum A003399. It is only
404 required during NOR boot.
406 CONFIG_A008044_WORKAROUND
407 Enables a workaround for T1040/T1042 erratum A008044. It is only
408 required during NAND boot and valid for Rev 1.0 SoC revision
410 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
412 This is the value to write into CCSR offset 0x18600
413 according to the A004510 workaround.
415 CONFIG_SYS_FSL_DSP_DDR_ADDR
416 This value denotes start offset of DDR memory which is
417 connected exclusively to the DSP cores.
419 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
420 This value denotes start offset of M2 memory
421 which is directly connected to the DSP core.
423 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
424 This value denotes start offset of M3 memory which is directly
425 connected to the DSP core.
427 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
428 This value denotes start offset of DSP CCSR space.
430 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
431 Single Source Clock is clocking mode present in some of FSL SoC's.
432 In this mode, a single differential clock is used to supply
433 clocks to the sysclock, ddrclock and usbclock.
435 CONFIG_SYS_CPC_REINIT_F
436 This CONFIG is defined when the CPC is configured as SRAM at the
437 time of U-boot entry and is required to be re-initialized.
440 Indicates this SoC supports deep sleep feature. If deep sleep is
441 supported, core will start to execute uboot when wakes up.
443 - Generic CPU options:
444 CONFIG_SYS_GENERIC_GLOBAL_DATA
445 Defines global data is initialized in generic board board_init_f().
446 If this macro is defined, global data is created and cleared in
447 generic board board_init_f(). Without this macro, architecture/board
448 should initialize global data before calling board_init_f().
450 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
452 Defines the endianess of the CPU. Implementation of those
453 values is arch specific.
456 Freescale DDR driver in use. This type of DDR controller is
457 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
460 CONFIG_SYS_FSL_DDR_ADDR
461 Freescale DDR memory-mapped register base.
463 CONFIG_SYS_FSL_DDR_EMU
464 Specify emulator support for DDR. Some DDR features such as
465 deskew training are not available.
467 CONFIG_SYS_FSL_DDRC_GEN1
468 Freescale DDR1 controller.
470 CONFIG_SYS_FSL_DDRC_GEN2
471 Freescale DDR2 controller.
473 CONFIG_SYS_FSL_DDRC_GEN3
474 Freescale DDR3 controller.
476 CONFIG_SYS_FSL_DDRC_GEN4
477 Freescale DDR4 controller.
479 CONFIG_SYS_FSL_DDRC_ARM_GEN3
480 Freescale DDR3 controller for ARM-based SoCs.
483 Board config to use DDR1. It can be enabled for SoCs with
484 Freescale DDR1 or DDR2 controllers, depending on the board
488 Board config to use DDR2. It can be eanbeld for SoCs with
489 Freescale DDR2 or DDR3 controllers, depending on the board
493 Board config to use DDR3. It can be enabled for SoCs with
494 Freescale DDR3 or DDR3L controllers.
497 Board config to use DDR3L. It can be enabled for SoCs with
501 Board config to use DDR4. It can be enabled for SoCs with
504 CONFIG_SYS_FSL_IFC_BE
505 Defines the IFC controller register space as Big Endian
507 CONFIG_SYS_FSL_IFC_LE
508 Defines the IFC controller register space as Little Endian
510 CONFIG_SYS_FSL_PBL_PBI
511 It enables addition of RCW (Power on reset configuration) in built image.
512 Please refer doc/README.pblimage for more details
514 CONFIG_SYS_FSL_PBL_RCW
515 It adds PBI(pre-boot instructions) commands in u-boot build image.
516 PBI commands can be used to configure SoC before it starts the execution.
517 Please refer doc/README.pblimage for more details
520 It adds a target to create boot binary having SPL binary in PBI format
521 concatenated with u-boot binary.
523 CONFIG_SYS_FSL_DDR_BE
524 Defines the DDR controller register space as Big Endian
526 CONFIG_SYS_FSL_DDR_LE
527 Defines the DDR controller register space as Little Endian
529 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
530 Physical address from the view of DDR controllers. It is the
531 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
532 it could be different for ARM SoCs.
534 CONFIG_SYS_FSL_DDR_INTLV_256B
535 DDR controller interleaving on 256-byte. This is a special
536 interleaving mode, handled by Dickens for Freescale layerscape
539 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
540 Number of controllers used as main memory.
542 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
543 Number of controllers used for other than main memory.
545 CONFIG_SYS_FSL_SEC_BE
546 Defines the SEC controller register space as Big Endian
548 CONFIG_SYS_FSL_SEC_LE
549 Defines the SEC controller register space as Little Endian
551 - Intel Monahans options:
552 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
554 Defines the Monahans run mode to oscillator
555 ratio. Valid values are 8, 16, 24, 31. The core
556 frequency is this value multiplied by 13 MHz.
558 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
560 Defines the Monahans turbo mode to oscillator
561 ratio. Valid values are 1 (default if undefined) and
562 2. The core frequency as calculated above is multiplied
566 CONFIG_SYS_INIT_SP_OFFSET
568 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
569 pointer. This is needed for the temporary stack before
572 CONFIG_SYS_MIPS_CACHE_MODE
574 Cache operation mode for the MIPS CPU.
575 See also arch/mips/include/asm/mipsregs.h.
577 CONF_CM_CACHABLE_NO_WA
580 CONF_CM_CACHABLE_NONCOHERENT
584 CONF_CM_CACHABLE_ACCELERATED
586 CONFIG_SYS_XWAY_EBU_BOOTCFG
588 Special option for Lantiq XWAY SoCs for booting from NOR flash.
589 See also arch/mips/cpu/mips32/start.S.
591 CONFIG_XWAY_SWAP_BYTES
593 Enable compilation of tools/xway-swap-bytes needed for Lantiq
594 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
595 be swapped if a flash programmer is used.
598 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
600 Select high exception vectors of the ARM core, e.g., do not
601 clear the V bit of the c1 register of CP15.
603 CONFIG_SYS_THUMB_BUILD
605 Use this flag to build U-Boot using the Thumb instruction
606 set for ARM architectures. Thumb instruction set provides
607 better code density. For ARM architectures that support
608 Thumb2 this flag will result in Thumb2 code generated by
611 CONFIG_ARM_ERRATA_716044
612 CONFIG_ARM_ERRATA_742230
613 CONFIG_ARM_ERRATA_743622
614 CONFIG_ARM_ERRATA_751472
615 CONFIG_ARM_ERRATA_794072
616 CONFIG_ARM_ERRATA_761320
618 If set, the workarounds for these ARM errata are applied early
619 during U-Boot startup. Note that these options force the
620 workarounds to be applied; no CPU-type/version detection
621 exists, unlike the similar options in the Linux kernel. Do not
622 set these options unless they apply!
625 CONFIG_TEGRA_SUPPORT_NON_SECURE
627 Support executing U-Boot in non-secure (NS) mode. Certain
628 impossible actions will be skipped if the CPU is in NS mode,
629 such as ARM architectural timer initialization.
632 Driver model is a new framework for devices in U-Boot
633 introduced in early 2014. U-Boot is being progressively
634 moved over to this. It offers a consistent device structure,
635 supports grouping devices into classes and has built-in
636 handling of platform data and device tree.
638 To enable transition to driver model in a relatively
639 painful fashion, each subsystem can be independently
640 switched between the legacy/ad-hoc approach and the new
641 driver model using the options below. Also, many uclass
642 interfaces include compatibility features which may be
643 removed once the conversion of that subsystem is complete.
644 As a result, the API provided by the subsystem may in fact
645 not change with driver model.
647 See doc/driver-model/README.txt for more information.
651 Enable driver model. This brings in the core support,
652 including scanning of platform data on start-up. If
653 CONFIG_OF_CONTROL is enabled, the device tree will be
654 scanned also when available.
658 Enable driver model test commands. These allow you to print
659 out the driver model tree and the uclasses.
663 Enable some demo devices and the 'demo' command. These are
664 really only useful for playing around while trying to
665 understand driver model in sandbox.
669 Enable driver model in SPL. You will need to provide a
670 suitable malloc() implementation. If you are not using the
671 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
672 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
673 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
674 In most cases driver model will only allocate a few uclasses
675 and devices in SPL, so 1KB should be enable. See
676 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
681 Enable driver model for serial. This replaces
682 drivers/serial/serial.c with the serial uclass, which
683 implements serial_putc() etc. The uclass interface is
684 defined in include/serial.h.
688 Enable driver model for GPIO access. The standard GPIO
689 interface (gpio_get_value(), etc.) is then implemented by
690 the GPIO uclass. Drivers provide methods to query the
691 particular GPIOs that they provide. The uclass interface
692 is defined in include/asm-generic/gpio.h.
696 Enable driver model for SPI. The SPI slave interface
697 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
698 the SPI uclass. Drivers provide methods to access the SPI
699 buses that they control. The uclass interface is defined in
700 include/spi.h. The existing spi_slave structure is attached
701 as 'parent data' to every slave on each bus. Slaves
702 typically use driver-private data instead of extending the
707 Enable driver model for SPI flash. This SPI flash interface
708 (spi_flash_probe(), spi_flash_write(), etc.) is then
709 implemented by the SPI flash uclass. There is one standard
710 SPI flash driver which knows how to probe most chips
711 supported by U-Boot. The uclass interface is defined in
712 include/spi_flash.h, but is currently fully compatible
713 with the old interface to avoid confusion and duplication
714 during the transition parent. SPI and SPI flash must be
715 enabled together (it is not possible to use driver model
716 for one and not the other).
720 Enable driver model for the Chrome OS EC interface. This
721 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
722 but otherwise makes few changes. Since cros_ec also supports
723 I2C and LPC (which don't support driver model yet), a full
724 conversion is not yet possible.
727 ** Code size options: The following options are enabled by
728 default except in SPL. Enable them explicitly to get these
733 Enable the dm_warn() function. This can use up quite a bit
734 of space for its strings.
738 Enable registering a serial device with the stdio library.
740 CONFIG_DM_DEVICE_REMOVE
742 Enable removing of devices.
745 - Linux Kernel Interface:
748 U-Boot stores all clock information in Hz
749 internally. For binary compatibility with older Linux
750 kernels (which expect the clocks passed in the
751 bd_info data to be in MHz) the environment variable
752 "clocks_in_mhz" can be defined so that U-Boot
753 converts clock data to MHZ before passing it to the
755 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
756 "clocks_in_mhz=1" is automatically included in the
759 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
761 When transferring memsize parameter to Linux, some versions
762 expect it to be in bytes, others in MB.
763 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
767 New kernel versions are expecting firmware settings to be
768 passed using flattened device trees (based on open firmware
772 * New libfdt-based support
773 * Adds the "fdt" command
774 * The bootm command automatically updates the fdt
776 OF_CPU - The proper name of the cpus node (only required for
777 MPC512X and MPC5xxx based boards).
778 OF_SOC - The proper name of the soc node (only required for
779 MPC512X and MPC5xxx based boards).
780 OF_TBCLK - The timebase frequency.
781 OF_STDOUT_PATH - The path to the console device
783 boards with QUICC Engines require OF_QE to set UCC MAC
786 CONFIG_OF_BOARD_SETUP
788 Board code has addition modification that it wants to make
789 to the flat device tree before handing it off to the kernel
791 CONFIG_OF_SYSTEM_SETUP
793 Other code has addition modification that it wants to make
794 to the flat device tree before handing it off to the kernel.
795 This causes ft_system_setup() to be called before booting
800 This define fills in the correct boot CPU in the boot
801 param header, the default value is zero if undefined.
805 U-Boot can detect if an IDE device is present or not.
806 If not, and this new config option is activated, U-Boot
807 removes the ATA node from the DTS before booting Linux,
808 so the Linux IDE driver does not probe the device and
809 crash. This is needed for buggy hardware (uc101) where
810 no pull down resistor is connected to the signal IDE5V_DD7.
812 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
814 This setting is mandatory for all boards that have only one
815 machine type and must be used to specify the machine type
816 number as it appears in the ARM machine registry
817 (see http://www.arm.linux.org.uk/developer/machines/).
818 Only boards that have multiple machine types supported
819 in a single configuration file and the machine type is
820 runtime discoverable, do not have to use this setting.
822 - vxWorks boot parameters:
824 bootvx constructs a valid bootline using the following
825 environments variables: bootfile, ipaddr, serverip, hostname.
826 It loads the vxWorks image pointed bootfile.
828 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
829 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
830 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
831 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
833 CONFIG_SYS_VXWORKS_ADD_PARAMS
835 Add it at the end of the bootline. E.g "u=username pw=secret"
837 Note: If a "bootargs" environment is defined, it will overwride
838 the defaults discussed just above.
840 - Cache Configuration:
841 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
842 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
843 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
845 - Cache Configuration for ARM:
846 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
848 CONFIG_SYS_PL310_BASE - Physical base address of PL310
849 controller register space
854 Define this if you want support for Amba PrimeCell PL010 UARTs.
858 Define this if you want support for Amba PrimeCell PL011 UARTs.
862 If you have Amba PrimeCell PL011 UARTs, set this variable to
863 the clock speed of the UARTs.
867 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
868 define this to a list of base addresses for each (supported)
869 port. See e.g. include/configs/versatile.h
871 CONFIG_PL011_SERIAL_RLCR
873 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
874 have separate receive and transmit line control registers. Set
875 this variable to initialize the extra register.
877 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
879 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
880 boot loader that has already initialized the UART. Define this
881 variable to flush the UART at init time.
883 CONFIG_SERIAL_HW_FLOW_CONTROL
885 Define this variable to enable hw flow control in serial driver.
886 Current user of this option is drivers/serial/nsl16550.c driver
889 Depending on board, define exactly one serial port
890 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
891 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
892 console by defining CONFIG_8xx_CONS_NONE
894 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
895 port routines must be defined elsewhere
896 (i.e. serial_init(), serial_getc(), ...)
899 Enables console device for a color framebuffer. Needs following
900 defines (cf. smiLynxEM, i8042)
901 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
903 VIDEO_HW_RECTFILL graphic chip supports
906 VIDEO_HW_BITBLT graphic chip supports
907 bit-blit (cf. smiLynxEM)
908 VIDEO_VISIBLE_COLS visible pixel columns
910 VIDEO_VISIBLE_ROWS visible pixel rows
911 VIDEO_PIXEL_SIZE bytes per pixel
912 VIDEO_DATA_FORMAT graphic data format
913 (0-5, cf. cfb_console.c)
914 VIDEO_FB_ADRS framebuffer address
915 VIDEO_KBD_INIT_FCT keyboard int fct
916 (i.e. i8042_kbd_init())
917 VIDEO_TSTC_FCT test char fct
919 VIDEO_GETC_FCT get char fct
921 CONFIG_CONSOLE_CURSOR cursor drawing on/off
922 (requires blink timer
924 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
925 CONFIG_CONSOLE_TIME display time/date info in
927 (requires CONFIG_CMD_DATE)
928 CONFIG_VIDEO_LOGO display Linux logo in
930 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
931 linux_logo.h for logo.
932 Requires CONFIG_VIDEO_LOGO
933 CONFIG_CONSOLE_EXTRA_INFO
934 additional board info beside
937 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
938 a limited number of ANSI escape sequences (cursor control,
939 erase functions and limited graphics rendition control).
941 When CONFIG_CFB_CONSOLE is defined, video console is
942 default i/o. Serial console can be forced with
943 environment 'console=serial'.
945 When CONFIG_SILENT_CONSOLE is defined, all console
946 messages (by U-Boot and Linux!) can be silenced with
947 the "silent" environment variable. See
948 doc/README.silent for more information.
950 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
952 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
956 CONFIG_BAUDRATE - in bps
957 Select one of the baudrates listed in
958 CONFIG_SYS_BAUDRATE_TABLE, see below.
959 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
961 - Console Rx buffer length
962 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
963 the maximum receive buffer length for the SMC.
964 This option is actual only for 82xx and 8xx possible.
965 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
966 must be defined, to setup the maximum idle timeout for
969 - Pre-Console Buffer:
970 Prior to the console being initialised (i.e. serial UART
971 initialised etc) all console output is silently discarded.
972 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
973 buffer any console messages prior to the console being
974 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
975 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
976 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
977 bytes are output before the console is initialised, the
978 earlier bytes are discarded.
980 'Sane' compilers will generate smaller code if
981 CONFIG_PRE_CON_BUF_SZ is a power of 2
983 - Safe printf() functions
984 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
985 the printf() functions. These are defined in
986 include/vsprintf.h and include snprintf(), vsnprintf() and
987 so on. Code size increase is approximately 300-500 bytes.
988 If this option is not given then these functions will
989 silently discard their buffer size argument - this means
990 you are not getting any overflow checking in this case.
992 - Boot Delay: CONFIG_BOOTDELAY - in seconds
993 Delay before automatically booting the default image;
994 set to -1 to disable autoboot.
995 set to -2 to autoboot with no delay and not check for abort
996 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
998 See doc/README.autoboot for these options that
999 work with CONFIG_BOOTDELAY. None are required.
1000 CONFIG_BOOT_RETRY_TIME
1001 CONFIG_BOOT_RETRY_MIN
1002 CONFIG_AUTOBOOT_KEYED
1003 CONFIG_AUTOBOOT_PROMPT
1004 CONFIG_AUTOBOOT_DELAY_STR
1005 CONFIG_AUTOBOOT_STOP_STR
1006 CONFIG_AUTOBOOT_DELAY_STR2
1007 CONFIG_AUTOBOOT_STOP_STR2
1008 CONFIG_ZERO_BOOTDELAY_CHECK
1009 CONFIG_RESET_TO_RETRY
1013 Only needed when CONFIG_BOOTDELAY is enabled;
1014 define a command string that is automatically executed
1015 when no character is read on the console interface
1016 within "Boot Delay" after reset.
1019 This can be used to pass arguments to the bootm
1020 command. The value of CONFIG_BOOTARGS goes into the
1021 environment value "bootargs".
1023 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1024 The value of these goes into the environment as
1025 "ramboot" and "nfsboot" respectively, and can be used
1026 as a convenience, when switching between booting from
1030 CONFIG_BOOTCOUNT_LIMIT
1031 Implements a mechanism for detecting a repeating reboot
1033 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1035 CONFIG_BOOTCOUNT_ENV
1036 If no softreset save registers are found on the hardware
1037 "bootcount" is stored in the environment. To prevent a
1038 saveenv on all reboots, the environment variable
1039 "upgrade_available" is used. If "upgrade_available" is
1040 0, "bootcount" is always 0, if "upgrade_available" is
1041 1 "bootcount" is incremented in the environment.
1042 So the Userspace Applikation must set the "upgrade_available"
1043 and "bootcount" variable to 0, if a boot was successfully.
1045 - Pre-Boot Commands:
1048 When this option is #defined, the existence of the
1049 environment variable "preboot" will be checked
1050 immediately before starting the CONFIG_BOOTDELAY
1051 countdown and/or running the auto-boot command resp.
1052 entering interactive mode.
1054 This feature is especially useful when "preboot" is
1055 automatically generated or modified. For an example
1056 see the LWMON board specific code: here "preboot" is
1057 modified when the user holds down a certain
1058 combination of keys on the (special) keyboard when
1061 - Serial Download Echo Mode:
1063 If defined to 1, all characters received during a
1064 serial download (using the "loads" command) are
1065 echoed back. This might be needed by some terminal
1066 emulations (like "cu"), but may as well just take
1067 time on others. This setting #define's the initial
1068 value of the "loads_echo" environment variable.
1070 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1071 CONFIG_KGDB_BAUDRATE
1072 Select one of the baudrates listed in
1073 CONFIG_SYS_BAUDRATE_TABLE, see below.
1075 - Monitor Functions:
1076 Monitor commands can be included or excluded
1077 from the build by using the #include files
1078 <config_cmd_all.h> and #undef'ing unwanted
1079 commands, or using <config_cmd_default.h>
1080 and augmenting with additional #define's
1081 for wanted commands.
1083 The default command configuration includes all commands
1084 except those marked below with a "*".
1086 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1087 CONFIG_CMD_ASKENV * ask for env variable
1088 CONFIG_CMD_BDI bdinfo
1089 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1090 CONFIG_CMD_BMP * BMP support
1091 CONFIG_CMD_BSP * Board specific commands
1092 CONFIG_CMD_BOOTD bootd
1093 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1094 CONFIG_CMD_CACHE * icache, dcache
1095 CONFIG_CMD_CLK * clock command support
1096 CONFIG_CMD_CONSOLE coninfo
1097 CONFIG_CMD_CRC32 * crc32
1098 CONFIG_CMD_DATE * support for RTC, date/time...
1099 CONFIG_CMD_DHCP * DHCP support
1100 CONFIG_CMD_DIAG * Diagnostics
1101 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1102 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1103 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1104 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1105 CONFIG_CMD_DTT * Digital Therm and Thermostat
1106 CONFIG_CMD_ECHO echo arguments
1107 CONFIG_CMD_EDITENV edit env variable
1108 CONFIG_CMD_EEPROM * EEPROM read/write support
1109 CONFIG_CMD_ELF * bootelf, bootvx
1110 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1111 CONFIG_CMD_ENV_FLAGS * display details about env flags
1112 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1113 CONFIG_CMD_EXPORTENV * export the environment
1114 CONFIG_CMD_EXT2 * ext2 command support
1115 CONFIG_CMD_EXT4 * ext4 command support
1116 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1117 that work for multiple fs types
1118 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1119 CONFIG_CMD_SAVEENV saveenv
1120 CONFIG_CMD_FDC * Floppy Disk Support
1121 CONFIG_CMD_FAT * FAT command support
1122 CONFIG_CMD_FLASH flinfo, erase, protect
1123 CONFIG_CMD_FPGA FPGA device initialization support
1124 CONFIG_CMD_FUSE * Device fuse support
1125 CONFIG_CMD_GETTIME * Get time since boot
1126 CONFIG_CMD_GO * the 'go' command (exec code)
1127 CONFIG_CMD_GREPENV * search environment
1128 CONFIG_CMD_HASH * calculate hash / digest
1129 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1130 CONFIG_CMD_I2C * I2C serial bus support
1131 CONFIG_CMD_IDE * IDE harddisk support
1132 CONFIG_CMD_IMI iminfo
1133 CONFIG_CMD_IMLS List all images found in NOR flash
1134 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1135 CONFIG_CMD_IMMAP * IMMR dump support
1136 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1137 CONFIG_CMD_IMPORTENV * import an environment
1138 CONFIG_CMD_INI * import data from an ini file into the env
1139 CONFIG_CMD_IRQ * irqinfo
1140 CONFIG_CMD_ITEST Integer/string test of 2 values
1141 CONFIG_CMD_JFFS2 * JFFS2 Support
1142 CONFIG_CMD_KGDB * kgdb
1143 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1144 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1146 CONFIG_CMD_LOADB loadb
1147 CONFIG_CMD_LOADS loads
1148 CONFIG_CMD_MD5SUM * print md5 message digest
1149 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1150 CONFIG_CMD_MEMINFO * Display detailed memory information
1151 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1153 CONFIG_CMD_MEMTEST * mtest
1154 CONFIG_CMD_MISC Misc functions like sleep etc
1155 CONFIG_CMD_MMC * MMC memory mapped support
1156 CONFIG_CMD_MII * MII utility commands
1157 CONFIG_CMD_MTDPARTS * MTD partition support
1158 CONFIG_CMD_NAND * NAND support
1159 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1160 CONFIG_CMD_NFS NFS support
1161 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1162 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1163 CONFIG_CMD_PCI * pciinfo
1164 CONFIG_CMD_PCMCIA * PCMCIA support
1165 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1167 CONFIG_CMD_PORTIO * Port I/O
1168 CONFIG_CMD_READ * Read raw data from partition
1169 CONFIG_CMD_REGINFO * Register dump
1170 CONFIG_CMD_RUN run command in env variable
1171 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1172 CONFIG_CMD_SAVES * save S record dump
1173 CONFIG_CMD_SCSI * SCSI Support
1174 CONFIG_CMD_SDRAM * print SDRAM configuration information
1175 (requires CONFIG_CMD_I2C)
1176 CONFIG_CMD_SETGETDCR Support for DCR Register access
1178 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1179 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1180 (requires CONFIG_CMD_MEMORY)
1181 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1182 CONFIG_CMD_SOURCE "source" command Support
1183 CONFIG_CMD_SPI * SPI serial bus support
1184 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1185 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1186 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1187 CONFIG_CMD_TIMER * access to the system tick timer
1188 CONFIG_CMD_USB * USB support
1189 CONFIG_CMD_CDP * Cisco Discover Protocol support
1190 CONFIG_CMD_MFSL * Microblaze FSL support
1191 CONFIG_CMD_XIMG Load part of Multi Image
1192 CONFIG_CMD_UUID * Generate random UUID or GUID string
1194 EXAMPLE: If you want all functions except of network
1195 support you can write:
1197 #include "config_cmd_all.h"
1198 #undef CONFIG_CMD_NET
1201 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1203 Note: Don't enable the "icache" and "dcache" commands
1204 (configuration option CONFIG_CMD_CACHE) unless you know
1205 what you (and your U-Boot users) are doing. Data
1206 cache cannot be enabled on systems like the 8xx or
1207 8260 (where accesses to the IMMR region must be
1208 uncached), and it cannot be disabled on all other
1209 systems where we (mis-) use the data cache to hold an
1210 initial stack and some data.
1213 XXX - this list needs to get updated!
1215 - Regular expression support:
1217 If this variable is defined, U-Boot is linked against
1218 the SLRE (Super Light Regular Expression) library,
1219 which adds regex support to some commands, as for
1220 example "env grep" and "setexpr".
1224 If this variable is defined, U-Boot will use a device tree
1225 to configure its devices, instead of relying on statically
1226 compiled #defines in the board file. This option is
1227 experimental and only available on a few boards. The device
1228 tree is available in the global data as gd->fdt_blob.
1230 U-Boot needs to get its device tree from somewhere. This can
1231 be done using one of the two options below:
1234 If this variable is defined, U-Boot will embed a device tree
1235 binary in its image. This device tree file should be in the
1236 board directory and called <soc>-<board>.dts. The binary file
1237 is then picked up in board_init_f() and made available through
1238 the global data structure as gd->blob.
1241 If this variable is defined, U-Boot will build a device tree
1242 binary. It will be called u-boot.dtb. Architecture-specific
1243 code will locate it at run-time. Generally this works by:
1245 cat u-boot.bin u-boot.dtb >image.bin
1247 and in fact, U-Boot does this for you, creating a file called
1248 u-boot-dtb.bin which is useful in the common case. You can
1249 still use the individual files if you need something more
1254 If this variable is defined, it enables watchdog
1255 support for the SoC. There must be support in the SoC
1256 specific code for a watchdog. For the 8xx and 8260
1257 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1258 register. When supported for a specific SoC is
1259 available, then no further board specific code should
1260 be needed to use it.
1263 When using a watchdog circuitry external to the used
1264 SoC, then define this variable and provide board
1265 specific code for the "hw_watchdog_reset" function.
1267 CONFIG_AT91_HW_WDT_TIMEOUT
1268 specify the timeout in seconds. default 2 seconds.
1271 CONFIG_VERSION_VARIABLE
1272 If this variable is defined, an environment variable
1273 named "ver" is created by U-Boot showing the U-Boot
1274 version as printed by the "version" command.
1275 Any change to this variable will be reverted at the
1280 When CONFIG_CMD_DATE is selected, the type of the RTC
1281 has to be selected, too. Define exactly one of the
1284 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1285 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1286 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1287 CONFIG_RTC_MC146818 - use MC146818 RTC
1288 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1289 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1290 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1291 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1292 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1293 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1294 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1295 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1296 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1299 Note that if the RTC uses I2C, then the I2C interface
1300 must also be configured. See I2C Support, below.
1303 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1305 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1306 chip-ngpio pairs that tell the PCA953X driver the number of
1307 pins supported by a particular chip.
1309 Note that if the GPIO device uses I2C, then the I2C interface
1310 must also be configured. See I2C Support, below.
1313 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1314 accesses and can checksum them or write a list of them out
1315 to memory. See the 'iotrace' command for details. This is
1316 useful for testing device drivers since it can confirm that
1317 the driver behaves the same way before and after a code
1318 change. Currently this is supported on sandbox and arm. To
1319 add support for your architecture, add '#include <iotrace.h>'
1320 to the bottom of arch/<arch>/include/asm/io.h and test.
1322 Example output from the 'iotrace stats' command is below.
1323 Note that if the trace buffer is exhausted, the checksum will
1324 still continue to operate.
1327 Start: 10000000 (buffer start address)
1328 Size: 00010000 (buffer size)
1329 Offset: 00000120 (current buffer offset)
1330 Output: 10000120 (start + offset)
1331 Count: 00000018 (number of trace records)
1332 CRC32: 9526fb66 (CRC32 of all trace records)
1334 - Timestamp Support:
1336 When CONFIG_TIMESTAMP is selected, the timestamp
1337 (date and time) of an image is printed by image
1338 commands like bootm or iminfo. This option is
1339 automatically enabled when you select CONFIG_CMD_DATE .
1341 - Partition Labels (disklabels) Supported:
1342 Zero or more of the following:
1343 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1344 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1345 Intel architecture, USB sticks, etc.
1346 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1347 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1348 bootloader. Note 2TB partition limit; see
1350 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1352 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1353 CONFIG_CMD_SCSI) you must configure support for at
1354 least one non-MTD partition type as well.
1357 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1358 board configurations files but used nowhere!
1360 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1361 be performed by calling the function
1362 ide_set_reset(int reset)
1363 which has to be defined in a board specific file
1368 Set this to enable ATAPI support.
1373 Set this to enable support for disks larger than 137GB
1374 Also look at CONFIG_SYS_64BIT_LBA.
1375 Whithout these , LBA48 support uses 32bit variables and will 'only'
1376 support disks up to 2.1TB.
1378 CONFIG_SYS_64BIT_LBA:
1379 When enabled, makes the IDE subsystem use 64bit sector addresses.
1383 At the moment only there is only support for the
1384 SYM53C8XX SCSI controller; define
1385 CONFIG_SCSI_SYM53C8XX to enable it.
1387 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1388 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1389 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1390 maximum numbers of LUNs, SCSI ID's and target
1392 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1394 The environment variable 'scsidevs' is set to the number of
1395 SCSI devices found during the last scan.
1397 - NETWORK Support (PCI):
1399 Support for Intel 8254x/8257x gigabit chips.
1402 Utility code for direct access to the SPI bus on Intel 8257x.
1403 This does not do anything useful unless you set at least one
1404 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1406 CONFIG_E1000_SPI_GENERIC
1407 Allow generic access to the SPI bus on the Intel 8257x, for
1408 example with the "sspi" command.
1411 Management command for E1000 devices. When used on devices
1412 with SPI support you can reprogram the EEPROM from U-Boot.
1414 CONFIG_E1000_FALLBACK_MAC
1415 default MAC for empty EEPROM after production.
1418 Support for Intel 82557/82559/82559ER chips.
1419 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1420 write routine for first time initialisation.
1423 Support for Digital 2114x chips.
1424 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1425 modem chip initialisation (KS8761/QS6611).
1428 Support for National dp83815 chips.
1431 Support for National dp8382[01] gigabit chips.
1433 - NETWORK Support (other):
1435 CONFIG_DRIVER_AT91EMAC
1436 Support for AT91RM9200 EMAC.
1439 Define this to use reduced MII inteface
1441 CONFIG_DRIVER_AT91EMAC_QUIET
1442 If this defined, the driver is quiet.
1443 The driver doen't show link status messages.
1445 CONFIG_CALXEDA_XGMAC
1446 Support for the Calxeda XGMAC device
1449 Support for SMSC's LAN91C96 chips.
1451 CONFIG_LAN91C96_BASE
1452 Define this to hold the physical address
1453 of the LAN91C96's I/O space
1455 CONFIG_LAN91C96_USE_32_BIT
1456 Define this to enable 32 bit addressing
1459 Support for SMSC's LAN91C111 chip
1461 CONFIG_SMC91111_BASE
1462 Define this to hold the physical address
1463 of the device (I/O space)
1465 CONFIG_SMC_USE_32_BIT
1466 Define this if data bus is 32 bits
1468 CONFIG_SMC_USE_IOFUNCS
1469 Define this to use i/o functions instead of macros
1470 (some hardware wont work with macros)
1472 CONFIG_DRIVER_TI_EMAC
1473 Support for davinci emac
1475 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1476 Define this if you have more then 3 PHYs.
1479 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1481 CONFIG_FTGMAC100_EGIGA
1482 Define this to use GE link update with gigabit PHY.
1483 Define this if FTGMAC100 is connected to gigabit PHY.
1484 If your system has 10/100 PHY only, it might not occur
1485 wrong behavior. Because PHY usually return timeout or
1486 useless data when polling gigabit status and gigabit
1487 control registers. This behavior won't affect the
1488 correctnessof 10/100 link speed update.
1491 Support for SMSC's LAN911x and LAN921x chips
1494 Define this to hold the physical address
1495 of the device (I/O space)
1497 CONFIG_SMC911X_32_BIT
1498 Define this if data bus is 32 bits
1500 CONFIG_SMC911X_16_BIT
1501 Define this if data bus is 16 bits. If your processor
1502 automatically converts one 32 bit word to two 16 bit
1503 words you may also try CONFIG_SMC911X_32_BIT.
1506 Support for Renesas on-chip Ethernet controller
1508 CONFIG_SH_ETHER_USE_PORT
1509 Define the number of ports to be used
1511 CONFIG_SH_ETHER_PHY_ADDR
1512 Define the ETH PHY's address
1514 CONFIG_SH_ETHER_CACHE_WRITEBACK
1515 If this option is set, the driver enables cache flush.
1519 Support for PWM modul on the imx6.
1523 Support TPM devices.
1526 Support for i2c bus TPM devices. Only one device
1527 per system is supported at this time.
1529 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1530 Define the the i2c bus number for the TPM device
1532 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1533 Define the TPM's address on the i2c bus
1535 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1536 Define the burst count bytes upper limit
1538 CONFIG_TPM_ATMEL_TWI
1539 Support for Atmel TWI TPM device. Requires I2C support.
1542 Support for generic parallel port TPM devices. Only one device
1543 per system is supported at this time.
1545 CONFIG_TPM_TIS_BASE_ADDRESS
1546 Base address where the generic TPM device is mapped
1547 to. Contemporary x86 systems usually map it at
1551 Add tpm monitor functions.
1552 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1553 provides monitor access to authorized functions.
1556 Define this to enable the TPM support library which provides
1557 functional interfaces to some TPM commands.
1558 Requires support for a TPM device.
1560 CONFIG_TPM_AUTH_SESSIONS
1561 Define this to enable authorized functions in the TPM library.
1562 Requires CONFIG_TPM and CONFIG_SHA1.
1565 At the moment only the UHCI host controller is
1566 supported (PIP405, MIP405, MPC5200); define
1567 CONFIG_USB_UHCI to enable it.
1568 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1569 and define CONFIG_USB_STORAGE to enable the USB
1572 Supported are USB Keyboards and USB Floppy drives
1574 MPC5200 USB requires additional defines:
1576 for 528 MHz Clock: 0x0001bbbb
1580 for differential drivers: 0x00001000
1581 for single ended drivers: 0x00005000
1582 for differential drivers on PSC3: 0x00000100
1583 for single ended drivers on PSC3: 0x00004100
1584 CONFIG_SYS_USB_EVENT_POLL
1585 May be defined to allow interrupt polling
1586 instead of using asynchronous interrupts
1588 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1589 txfilltuning field in the EHCI controller on reset.
1591 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1592 HW module registers.
1595 Define the below if you wish to use the USB console.
1596 Once firmware is rebuilt from a serial console issue the
1597 command "setenv stdin usbtty; setenv stdout usbtty" and
1598 attach your USB cable. The Unix command "dmesg" should print
1599 it has found a new device. The environment variable usbtty
1600 can be set to gserial or cdc_acm to enable your device to
1601 appear to a USB host as a Linux gserial device or a
1602 Common Device Class Abstract Control Model serial device.
1603 If you select usbtty = gserial you should be able to enumerate
1605 # modprobe usbserial vendor=0xVendorID product=0xProductID
1606 else if using cdc_acm, simply setting the environment
1607 variable usbtty to be cdc_acm should suffice. The following
1608 might be defined in YourBoardName.h
1611 Define this to build a UDC device
1614 Define this to have a tty type of device available to
1615 talk to the UDC device
1618 Define this to enable the high speed support for usb
1619 device and usbtty. If this feature is enabled, a routine
1620 int is_usbd_high_speed(void)
1621 also needs to be defined by the driver to dynamically poll
1622 whether the enumeration has succeded at high speed or full
1625 CONFIG_SYS_CONSOLE_IS_IN_ENV
1626 Define this if you want stdin, stdout &/or stderr to
1630 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1631 Derive USB clock from external clock "blah"
1632 - CONFIG_SYS_USB_EXTC_CLK 0x02
1634 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1635 Derive USB clock from brgclk
1636 - CONFIG_SYS_USB_BRG_CLK 0x04
1638 If you have a USB-IF assigned VendorID then you may wish to
1639 define your own vendor specific values either in BoardName.h
1640 or directly in usbd_vendor_info.h. If you don't define
1641 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1642 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1643 should pretend to be a Linux device to it's target host.
1645 CONFIG_USBD_MANUFACTURER
1646 Define this string as the name of your company for
1647 - CONFIG_USBD_MANUFACTURER "my company"
1649 CONFIG_USBD_PRODUCT_NAME
1650 Define this string as the name of your product
1651 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1653 CONFIG_USBD_VENDORID
1654 Define this as your assigned Vendor ID from the USB
1655 Implementors Forum. This *must* be a genuine Vendor ID
1656 to avoid polluting the USB namespace.
1657 - CONFIG_USBD_VENDORID 0xFFFF
1659 CONFIG_USBD_PRODUCTID
1660 Define this as the unique Product ID
1662 - CONFIG_USBD_PRODUCTID 0xFFFF
1664 - ULPI Layer Support:
1665 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1666 the generic ULPI layer. The generic layer accesses the ULPI PHY
1667 via the platform viewport, so you need both the genric layer and
1668 the viewport enabled. Currently only Chipidea/ARC based
1669 viewport is supported.
1670 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1671 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1672 If your ULPI phy needs a different reference clock than the
1673 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1674 the appropriate value in Hz.
1677 The MMC controller on the Intel PXA is supported. To
1678 enable this define CONFIG_MMC. The MMC can be
1679 accessed from the boot prompt by mapping the device
1680 to physical memory similar to flash. Command line is
1681 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1682 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1685 Support for Renesas on-chip MMCIF controller
1687 CONFIG_SH_MMCIF_ADDR
1688 Define the base address of MMCIF registers
1691 Define the clock frequency for MMCIF
1694 Enable the generic MMC driver
1696 CONFIG_SUPPORT_EMMC_BOOT
1697 Enable some additional features of the eMMC boot partitions.
1699 CONFIG_SUPPORT_EMMC_RPMB
1700 Enable the commands for reading, writing and programming the
1701 key for the Replay Protection Memory Block partition in eMMC.
1703 - USB Device Firmware Update (DFU) class support:
1705 This enables the USB portion of the DFU USB class
1708 This enables the command "dfu" which is used to have
1709 U-Boot create a DFU class device via USB. This command
1710 requires that the "dfu_alt_info" environment variable be
1711 set and define the alt settings to expose to the host.
1714 This enables support for exposing (e)MMC devices via DFU.
1717 This enables support for exposing NAND devices via DFU.
1720 This enables support for exposing RAM via DFU.
1721 Note: DFU spec refer to non-volatile memory usage, but
1722 allow usages beyond the scope of spec - here RAM usage,
1723 one that would help mostly the developer.
1725 CONFIG_SYS_DFU_DATA_BUF_SIZE
1726 Dfu transfer uses a buffer before writing data to the
1727 raw storage device. Make the size (in bytes) of this buffer
1728 configurable. The size of this buffer is also configurable
1729 through the "dfu_bufsiz" environment variable.
1731 CONFIG_SYS_DFU_MAX_FILE_SIZE
1732 When updating files rather than the raw storage device,
1733 we use a static buffer to copy the file into and then write
1734 the buffer once we've been given the whole file. Define
1735 this to the maximum filesize (in bytes) for the buffer.
1736 Default is 4 MiB if undefined.
1738 DFU_DEFAULT_POLL_TIMEOUT
1739 Poll timeout [ms], is the timeout a device can send to the
1740 host. The host must wait for this timeout before sending
1741 a subsequent DFU_GET_STATUS request to the device.
1743 DFU_MANIFEST_POLL_TIMEOUT
1744 Poll timeout [ms], which the device sends to the host when
1745 entering dfuMANIFEST state. Host waits this timeout, before
1746 sending again an USB request to the device.
1748 - USB Device Android Fastboot support:
1750 This enables the command "fastboot" which enables the Android
1751 fastboot mode for the platform's USB device. Fastboot is a USB
1752 protocol for downloading images, flashing and device control
1753 used on Android devices.
1754 See doc/README.android-fastboot for more information.
1756 CONFIG_ANDROID_BOOT_IMAGE
1757 This enables support for booting images which use the Android
1758 image format header.
1760 CONFIG_USB_FASTBOOT_BUF_ADDR
1761 The fastboot protocol requires a large memory buffer for
1762 downloads. Define this to the starting RAM address to use for
1765 CONFIG_USB_FASTBOOT_BUF_SIZE
1766 The fastboot protocol requires a large memory buffer for
1767 downloads. This buffer should be as large as possible for a
1768 platform. Define this to the size available RAM for fastboot.
1770 CONFIG_FASTBOOT_FLASH
1771 The fastboot protocol includes a "flash" command for writing
1772 the downloaded image to a non-volatile storage device. Define
1773 this to enable the "fastboot flash" command.
1775 CONFIG_FASTBOOT_FLASH_MMC_DEV
1776 The fastboot "flash" command requires additional information
1777 regarding the non-volatile storage device. Define this to
1778 the eMMC device that fastboot should use to store the image.
1780 CONFIG_FASTBOOT_GPT_NAME
1781 The fastboot "flash" command supports writing the downloaded
1782 image to the Protective MBR and the Primary GUID Partition
1783 Table. (Additionally, this downloaded image is post-processed
1784 to generate and write the Backup GUID Partition Table.)
1785 This occurs when the specified "partition name" on the
1786 "fastboot flash" command line matches this value.
1787 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1789 - Journaling Flash filesystem support:
1790 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1791 CONFIG_JFFS2_NAND_DEV
1792 Define these for a default partition on a NAND device
1794 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1795 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1796 Define these for a default partition on a NOR device
1798 CONFIG_SYS_JFFS_CUSTOM_PART
1799 Define this to create an own partition. You have to provide a
1800 function struct part_info* jffs2_part_info(int part_num)
1802 If you define only one JFFS2 partition you may also want to
1803 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1804 to disable the command chpart. This is the default when you
1805 have not defined a custom partition
1807 - FAT(File Allocation Table) filesystem write function support:
1810 Define this to enable support for saving memory data as a
1811 file in FAT formatted partition.
1813 This will also enable the command "fatwrite" enabling the
1814 user to write files to FAT.
1816 CBFS (Coreboot Filesystem) support
1819 Define this to enable support for reading from a Coreboot
1820 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1823 - FAT(File Allocation Table) filesystem cluster size:
1824 CONFIG_FS_FAT_MAX_CLUSTSIZE
1826 Define the max cluster size for fat operations else
1827 a default value of 65536 will be defined.
1832 Define this to enable standard (PC-Style) keyboard
1836 Standard PC keyboard driver with US (is default) and
1837 GERMAN key layout (switch via environment 'keymap=de') support.
1838 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1839 for cfb_console. Supports cursor blinking.
1842 Enables a Chrome OS keyboard using the CROS_EC interface.
1843 This uses CROS_EC to communicate with a second microcontroller
1844 which provides key scans on request.
1849 Define this to enable video support (for output to
1852 CONFIG_VIDEO_CT69000
1854 Enable Chips & Technologies 69000 Video chip
1856 CONFIG_VIDEO_SMI_LYNXEM
1857 Enable Silicon Motion SMI 712/710/810 Video chip. The
1858 video output is selected via environment 'videoout'
1859 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1862 For the CT69000 and SMI_LYNXEM drivers, videomode is
1863 selected via environment 'videomode'. Two different ways
1865 - "videomode=num" 'num' is a standard LiLo mode numbers.
1866 Following standard modes are supported (* is default):
1868 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1869 -------------+---------------------------------------------
1870 8 bits | 0x301* 0x303 0x305 0x161 0x307
1871 15 bits | 0x310 0x313 0x316 0x162 0x319
1872 16 bits | 0x311 0x314 0x317 0x163 0x31A
1873 24 bits | 0x312 0x315 0x318 ? 0x31B
1874 -------------+---------------------------------------------
1875 (i.e. setenv videomode 317; saveenv; reset;)
1877 - "videomode=bootargs" all the video parameters are parsed
1878 from the bootargs. (See drivers/video/videomodes.c)
1881 CONFIG_VIDEO_SED13806
1882 Enable Epson SED13806 driver. This driver supports 8bpp
1883 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1884 or CONFIG_VIDEO_SED13806_16BPP
1887 Enable the Freescale DIU video driver. Reference boards for
1888 SOCs that have a DIU should define this macro to enable DIU
1889 support, and should also define these other macros:
1895 CONFIG_VIDEO_SW_CURSOR
1896 CONFIG_VGA_AS_SINGLE_DEVICE
1898 CONFIG_VIDEO_BMP_LOGO
1900 The DIU driver will look for the 'video-mode' environment
1901 variable, and if defined, enable the DIU as a console during
1902 boot. See the documentation file README.video for a
1903 description of this variable.
1907 Enable the VGA video / BIOS for x86. The alternative if you
1908 are using coreboot is to use the coreboot frame buffer
1915 Define this to enable a custom keyboard support.
1916 This simply calls drv_keyboard_init() which must be
1917 defined in your board-specific files.
1918 The only board using this so far is RBC823.
1920 - LCD Support: CONFIG_LCD
1922 Define this to enable LCD support (for output to LCD
1923 display); also select one of the supported displays
1924 by defining one of these:
1928 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1930 CONFIG_NEC_NL6448AC33:
1932 NEC NL6448AC33-18. Active, color, single scan.
1934 CONFIG_NEC_NL6448BC20
1936 NEC NL6448BC20-08. 6.5", 640x480.
1937 Active, color, single scan.
1939 CONFIG_NEC_NL6448BC33_54
1941 NEC NL6448BC33-54. 10.4", 640x480.
1942 Active, color, single scan.
1946 Sharp 320x240. Active, color, single scan.
1947 It isn't 16x9, and I am not sure what it is.
1949 CONFIG_SHARP_LQ64D341
1951 Sharp LQ64D341 display, 640x480.
1952 Active, color, single scan.
1956 HLD1045 display, 640x480.
1957 Active, color, single scan.
1961 Optrex CBL50840-2 NF-FW 99 22 M5
1963 Hitachi LMG6912RPFC-00T
1967 320x240. Black & white.
1969 Normally display is black on white background; define
1970 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1972 CONFIG_LCD_ALIGNMENT
1974 Normally the LCD is page-aligned (typically 4KB). If this is
1975 defined then the LCD will be aligned to this value instead.
1976 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1977 here, since it is cheaper to change data cache settings on
1978 a per-section basis.
1980 CONFIG_CONSOLE_SCROLL_LINES
1982 When the console need to be scrolled, this is the number of
1983 lines to scroll by. It defaults to 1. Increasing this makes
1984 the console jump but can help speed up operation when scrolling
1989 Support drawing of RLE8-compressed bitmaps on the LCD.
1993 Enables an 'i2c edid' command which can read EDID
1994 information over I2C from an attached LCD display.
1996 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1998 If this option is set, the environment is checked for
1999 a variable "splashimage". If found, the usual display
2000 of logo, copyright and system information on the LCD
2001 is suppressed and the BMP image at the address
2002 specified in "splashimage" is loaded instead. The
2003 console is redirected to the "nulldev", too. This
2004 allows for a "silent" boot where a splash screen is
2005 loaded very quickly after power-on.
2007 CONFIG_SPLASHIMAGE_GUARD
2009 If this option is set, then U-Boot will prevent the environment
2010 variable "splashimage" from being set to a problematic address
2011 (see README.displaying-bmps).
2012 This option is useful for targets where, due to alignment
2013 restrictions, an improperly aligned BMP image will cause a data
2014 abort. If you think you will not have problems with unaligned
2015 accesses (for example because your toolchain prevents them)
2016 there is no need to set this option.
2018 CONFIG_SPLASH_SCREEN_ALIGN
2020 If this option is set the splash image can be freely positioned
2021 on the screen. Environment variable "splashpos" specifies the
2022 position as "x,y". If a positive number is given it is used as
2023 number of pixel from left/top. If a negative number is given it
2024 is used as number of pixel from right/bottom. You can also
2025 specify 'm' for centering the image.
2028 setenv splashpos m,m
2029 => image at center of screen
2031 setenv splashpos 30,20
2032 => image at x = 30 and y = 20
2034 setenv splashpos -10,m
2035 => vertically centered image
2036 at x = dspWidth - bmpWidth - 9
2038 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2040 If this option is set, additionally to standard BMP
2041 images, gzipped BMP images can be displayed via the
2042 splashscreen support or the bmp command.
2044 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2046 If this option is set, 8-bit RLE compressed BMP images
2047 can be displayed via the splashscreen support or the
2050 - Do compressing for memory range:
2053 If this option is set, it would use zlib deflate method
2054 to compress the specified memory at its best effort.
2056 - Compression support:
2059 Enabled by default to support gzip compressed images.
2063 If this option is set, support for bzip2 compressed
2064 images is included. If not, only uncompressed and gzip
2065 compressed images are supported.
2067 NOTE: the bzip2 algorithm requires a lot of RAM, so
2068 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2073 If this option is set, support for lzma compressed
2076 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2077 requires an amount of dynamic memory that is given by the
2080 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2082 Where lc and lp stand for, respectively, Literal context bits
2083 and Literal pos bits.
2085 This value is upper-bounded by 14MB in the worst case. Anyway,
2086 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2087 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2088 a very small buffer.
2090 Use the lzmainfo tool to determinate the lc and lp values and
2091 then calculate the amount of needed dynamic memory (ensuring
2092 the appropriate CONFIG_SYS_MALLOC_LEN value).
2096 If this option is set, support for LZO compressed images
2102 The address of PHY on MII bus.
2104 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2106 The clock frequency of the MII bus
2110 If this option is set, support for speed/duplex
2111 detection of gigabit PHY is included.
2113 CONFIG_PHY_RESET_DELAY
2115 Some PHY like Intel LXT971A need extra delay after
2116 reset before any MII register access is possible.
2117 For such PHY, set this option to the usec delay
2118 required. (minimum 300usec for LXT971A)
2120 CONFIG_PHY_CMD_DELAY (ppc4xx)
2122 Some PHY like Intel LXT971A need extra delay after
2123 command issued before MII status register can be read
2133 Define a default value for Ethernet address to use
2134 for the respective Ethernet interface, in case this
2135 is not determined automatically.
2140 Define a default value for the IP address to use for
2141 the default Ethernet interface, in case this is not
2142 determined through e.g. bootp.
2143 (Environment variable "ipaddr")
2145 - Server IP address:
2148 Defines a default value for the IP address of a TFTP
2149 server to contact when using the "tftboot" command.
2150 (Environment variable "serverip")
2152 CONFIG_KEEP_SERVERADDR
2154 Keeps the server's MAC address, in the env 'serveraddr'
2155 for passing to bootargs (like Linux's netconsole option)
2157 - Gateway IP address:
2160 Defines a default value for the IP address of the
2161 default router where packets to other networks are
2163 (Environment variable "gatewayip")
2168 Defines a default value for the subnet mask (or
2169 routing prefix) which is used to determine if an IP
2170 address belongs to the local subnet or needs to be
2171 forwarded through a router.
2172 (Environment variable "netmask")
2174 - Multicast TFTP Mode:
2177 Defines whether you want to support multicast TFTP as per
2178 rfc-2090; for example to work with atftp. Lets lots of targets
2179 tftp down the same boot image concurrently. Note: the Ethernet
2180 driver in use must provide a function: mcast() to join/leave a
2183 - BOOTP Recovery Mode:
2184 CONFIG_BOOTP_RANDOM_DELAY
2186 If you have many targets in a network that try to
2187 boot using BOOTP, you may want to avoid that all
2188 systems send out BOOTP requests at precisely the same
2189 moment (which would happen for instance at recovery
2190 from a power failure, when all systems will try to
2191 boot, thus flooding the BOOTP server. Defining
2192 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2193 inserted before sending out BOOTP requests. The
2194 following delays are inserted then:
2196 1st BOOTP request: delay 0 ... 1 sec
2197 2nd BOOTP request: delay 0 ... 2 sec
2198 3rd BOOTP request: delay 0 ... 4 sec
2200 BOOTP requests: delay 0 ... 8 sec
2202 CONFIG_BOOTP_ID_CACHE_SIZE
2204 BOOTP packets are uniquely identified using a 32-bit ID. The
2205 server will copy the ID from client requests to responses and
2206 U-Boot will use this to determine if it is the destination of
2207 an incoming response. Some servers will check that addresses
2208 aren't in use before handing them out (usually using an ARP
2209 ping) and therefore take up to a few hundred milliseconds to
2210 respond. Network congestion may also influence the time it
2211 takes for a response to make it back to the client. If that
2212 time is too long, U-Boot will retransmit requests. In order
2213 to allow earlier responses to still be accepted after these
2214 retransmissions, U-Boot's BOOTP client keeps a small cache of
2215 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2216 cache. The default is to keep IDs for up to four outstanding
2217 requests. Increasing this will allow U-Boot to accept offers
2218 from a BOOTP client in networks with unusually high latency.
2220 - BOOTP Random transaction ID:
2221 CONFIG_BOOTP_RANDOM_ID
2223 The standard algorithm to generate a DHCP/BOOTP transaction ID
2224 by using the MAC address and the current time stamp may not
2225 quite unlikely produce duplicate transaction IDs from different
2226 clients in the same network. This option creates a transaction
2227 ID using the rand() function. Provided that the RNG has been
2228 seeded well, this should guarantee unique transaction IDs
2231 - DHCP Advanced Options:
2232 You can fine tune the DHCP functionality by defining
2233 CONFIG_BOOTP_* symbols:
2235 CONFIG_BOOTP_SUBNETMASK
2236 CONFIG_BOOTP_GATEWAY
2237 CONFIG_BOOTP_HOSTNAME
2238 CONFIG_BOOTP_NISDOMAIN
2239 CONFIG_BOOTP_BOOTPATH
2240 CONFIG_BOOTP_BOOTFILESIZE
2243 CONFIG_BOOTP_SEND_HOSTNAME
2244 CONFIG_BOOTP_NTPSERVER
2245 CONFIG_BOOTP_TIMEOFFSET
2246 CONFIG_BOOTP_VENDOREX
2247 CONFIG_BOOTP_MAY_FAIL
2249 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2250 environment variable, not the BOOTP server.
2252 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2253 after the configured retry count, the call will fail
2254 instead of starting over. This can be used to fail over
2255 to Link-local IP address configuration if the DHCP server
2258 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2259 serverip from a DHCP server, it is possible that more
2260 than one DNS serverip is offered to the client.
2261 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2262 serverip will be stored in the additional environment
2263 variable "dnsip2". The first DNS serverip is always
2264 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2267 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2268 to do a dynamic update of a DNS server. To do this, they
2269 need the hostname of the DHCP requester.
2270 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2271 of the "hostname" environment variable is passed as
2272 option 12 to the DHCP server.
2274 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2276 A 32bit value in microseconds for a delay between
2277 receiving a "DHCP Offer" and sending the "DHCP Request".
2278 This fixes a problem with certain DHCP servers that don't
2279 respond 100% of the time to a "DHCP request". E.g. On an
2280 AT91RM9200 processor running at 180MHz, this delay needed
2281 to be *at least* 15,000 usec before a Windows Server 2003
2282 DHCP server would reply 100% of the time. I recommend at
2283 least 50,000 usec to be safe. The alternative is to hope
2284 that one of the retries will be successful but note that
2285 the DHCP timeout and retry process takes a longer than
2288 - Link-local IP address negotiation:
2289 Negotiate with other link-local clients on the local network
2290 for an address that doesn't require explicit configuration.
2291 This is especially useful if a DHCP server cannot be guaranteed
2292 to exist in all environments that the device must operate.
2294 See doc/README.link-local for more information.
2297 CONFIG_CDP_DEVICE_ID
2299 The device id used in CDP trigger frames.
2301 CONFIG_CDP_DEVICE_ID_PREFIX
2303 A two character string which is prefixed to the MAC address
2308 A printf format string which contains the ascii name of
2309 the port. Normally is set to "eth%d" which sets
2310 eth0 for the first Ethernet, eth1 for the second etc.
2312 CONFIG_CDP_CAPABILITIES
2314 A 32bit integer which indicates the device capabilities;
2315 0x00000010 for a normal host which does not forwards.
2319 An ascii string containing the version of the software.
2323 An ascii string containing the name of the platform.
2327 A 32bit integer sent on the trigger.
2329 CONFIG_CDP_POWER_CONSUMPTION
2331 A 16bit integer containing the power consumption of the
2332 device in .1 of milliwatts.
2334 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2336 A byte containing the id of the VLAN.
2338 - Status LED: CONFIG_STATUS_LED
2340 Several configurations allow to display the current
2341 status using a LED. For instance, the LED will blink
2342 fast while running U-Boot code, stop blinking as
2343 soon as a reply to a BOOTP request was received, and
2344 start blinking slow once the Linux kernel is running
2345 (supported by a status LED driver in the Linux
2346 kernel). Defining CONFIG_STATUS_LED enables this
2352 The status LED can be connected to a GPIO pin.
2353 In such cases, the gpio_led driver can be used as a
2354 status LED backend implementation. Define CONFIG_GPIO_LED
2355 to include the gpio_led driver in the U-Boot binary.
2357 CONFIG_GPIO_LED_INVERTED_TABLE
2358 Some GPIO connected LEDs may have inverted polarity in which
2359 case the GPIO high value corresponds to LED off state and
2360 GPIO low value corresponds to LED on state.
2361 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2362 with a list of GPIO LEDs that have inverted polarity.
2364 - CAN Support: CONFIG_CAN_DRIVER
2366 Defining CONFIG_CAN_DRIVER enables CAN driver support
2367 on those systems that support this (optional)
2368 feature, like the TQM8xxL modules.
2370 - I2C Support: CONFIG_SYS_I2C
2372 This enable the NEW i2c subsystem, and will allow you to use
2373 i2c commands at the u-boot command line (as long as you set
2374 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2375 based realtime clock chips or other i2c devices. See
2376 common/cmd_i2c.c for a description of the command line
2379 ported i2c driver to the new framework:
2380 - drivers/i2c/soft_i2c.c:
2381 - activate first bus with CONFIG_SYS_I2C_SOFT define
2382 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2383 for defining speed and slave address
2384 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2385 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2386 for defining speed and slave address
2387 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2388 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2389 for defining speed and slave address
2390 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2391 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2392 for defining speed and slave address
2394 - drivers/i2c/fsl_i2c.c:
2395 - activate i2c driver with CONFIG_SYS_I2C_FSL
2396 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2397 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2398 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2400 - If your board supports a second fsl i2c bus, define
2401 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2402 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2403 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2406 - drivers/i2c/tegra_i2c.c:
2407 - activate this driver with CONFIG_SYS_I2C_TEGRA
2408 - This driver adds 4 i2c buses with a fix speed from
2409 100000 and the slave addr 0!
2411 - drivers/i2c/ppc4xx_i2c.c
2412 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2413 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2414 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2416 - drivers/i2c/i2c_mxc.c
2417 - activate this driver with CONFIG_SYS_I2C_MXC
2418 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2419 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2420 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2421 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2422 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2423 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2424 If those defines are not set, default value is 100000
2425 for speed, and 0 for slave.
2427 - drivers/i2c/rcar_i2c.c:
2428 - activate this driver with CONFIG_SYS_I2C_RCAR
2429 - This driver adds 4 i2c buses
2431 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2432 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2433 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2434 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2435 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2436 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2437 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2438 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2439 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2441 - drivers/i2c/sh_i2c.c:
2442 - activate this driver with CONFIG_SYS_I2C_SH
2443 - This driver adds from 2 to 5 i2c buses
2445 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2446 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2447 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2448 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2449 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2450 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2451 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2452 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2453 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2454 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2455 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2456 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2457 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2459 - drivers/i2c/omap24xx_i2c.c
2460 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2461 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2462 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2463 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2464 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2465 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2466 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2467 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2468 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2469 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2470 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2472 - drivers/i2c/zynq_i2c.c
2473 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2474 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2475 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2477 - drivers/i2c/s3c24x0_i2c.c:
2478 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2479 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2480 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2481 with a fix speed from 100000 and the slave addr 0!
2483 - drivers/i2c/ihs_i2c.c
2484 - activate this driver with CONFIG_SYS_I2C_IHS
2485 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2486 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2487 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2488 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2489 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2490 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2491 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2492 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2493 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2494 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2495 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2496 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2500 CONFIG_SYS_NUM_I2C_BUSES
2501 Hold the number of i2c buses you want to use. If you
2502 don't use/have i2c muxes on your i2c bus, this
2503 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2506 CONFIG_SYS_I2C_DIRECT_BUS
2507 define this, if you don't use i2c muxes on your hardware.
2508 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2511 CONFIG_SYS_I2C_MAX_HOPS
2512 define how many muxes are maximal consecutively connected
2513 on one i2c bus. If you not use i2c muxes, omit this
2516 CONFIG_SYS_I2C_BUSES
2517 hold a list of buses you want to use, only used if
2518 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2519 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2520 CONFIG_SYS_NUM_I2C_BUSES = 9:
2522 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2523 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2524 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2525 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2526 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2527 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2528 {1, {I2C_NULL_HOP}}, \
2529 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2530 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2534 bus 0 on adapter 0 without a mux
2535 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2536 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2537 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2538 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2539 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2540 bus 6 on adapter 1 without a mux
2541 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2542 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2544 If you do not have i2c muxes on your board, omit this define.
2546 - Legacy I2C Support: CONFIG_HARD_I2C
2548 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2549 provides the following compelling advantages:
2551 - more than one i2c adapter is usable
2552 - approved multibus support
2553 - better i2c mux support
2555 ** Please consider updating your I2C driver now. **
2557 These enable legacy I2C serial bus commands. Defining
2558 CONFIG_HARD_I2C will include the appropriate I2C driver
2559 for the selected CPU.
2561 This will allow you to use i2c commands at the u-boot
2562 command line (as long as you set CONFIG_CMD_I2C in
2563 CONFIG_COMMANDS) and communicate with i2c based realtime
2564 clock chips. See common/cmd_i2c.c for a description of the
2565 command line interface.
2567 CONFIG_HARD_I2C selects a hardware I2C controller.
2569 There are several other quantities that must also be
2570 defined when you define CONFIG_HARD_I2C.
2572 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2573 to be the frequency (in Hz) at which you wish your i2c bus
2574 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2575 the CPU's i2c node address).
2577 Now, the u-boot i2c code for the mpc8xx
2578 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2579 and so its address should therefore be cleared to 0 (See,
2580 eg, MPC823e User's Manual p.16-473). So, set
2581 CONFIG_SYS_I2C_SLAVE to 0.
2583 CONFIG_SYS_I2C_INIT_MPC5XXX
2585 When a board is reset during an i2c bus transfer
2586 chips might think that the current transfer is still
2587 in progress. Reset the slave devices by sending start
2588 commands until the slave device responds.
2590 That's all that's required for CONFIG_HARD_I2C.
2592 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2593 then the following macros need to be defined (examples are
2594 from include/configs/lwmon.h):
2598 (Optional). Any commands necessary to enable the I2C
2599 controller or configure ports.
2601 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2605 (Only for MPC8260 CPU). The I/O port to use (the code
2606 assumes both bits are on the same port). Valid values
2607 are 0..3 for ports A..D.
2611 The code necessary to make the I2C data line active
2612 (driven). If the data line is open collector, this
2615 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2619 The code necessary to make the I2C data line tri-stated
2620 (inactive). If the data line is open collector, this
2623 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2627 Code that returns true if the I2C data line is high,
2630 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2634 If <bit> is true, sets the I2C data line high. If it
2635 is false, it clears it (low).
2637 eg: #define I2C_SDA(bit) \
2638 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2639 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2643 If <bit> is true, sets the I2C clock line high. If it
2644 is false, it clears it (low).
2646 eg: #define I2C_SCL(bit) \
2647 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2648 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2652 This delay is invoked four times per clock cycle so this
2653 controls the rate of data transfer. The data rate thus
2654 is 1 / (I2C_DELAY * 4). Often defined to be something
2657 #define I2C_DELAY udelay(2)
2659 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2661 If your arch supports the generic GPIO framework (asm/gpio.h),
2662 then you may alternatively define the two GPIOs that are to be
2663 used as SCL / SDA. Any of the previous I2C_xxx macros will
2664 have GPIO-based defaults assigned to them as appropriate.
2666 You should define these to the GPIO value as given directly to
2667 the generic GPIO functions.
2669 CONFIG_SYS_I2C_INIT_BOARD
2671 When a board is reset during an i2c bus transfer
2672 chips might think that the current transfer is still
2673 in progress. On some boards it is possible to access
2674 the i2c SCLK line directly, either by using the
2675 processor pin as a GPIO or by having a second pin
2676 connected to the bus. If this option is defined a
2677 custom i2c_init_board() routine in boards/xxx/board.c
2678 is run early in the boot sequence.
2680 CONFIG_SYS_I2C_BOARD_LATE_INIT
2682 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2683 defined a custom i2c_board_late_init() routine in
2684 boards/xxx/board.c is run AFTER the operations in i2c_init()
2685 is completed. This callpoint can be used to unreset i2c bus
2686 using CPU i2c controller register accesses for CPUs whose i2c
2687 controller provide such a method. It is called at the end of
2688 i2c_init() to allow i2c_init operations to setup the i2c bus
2689 controller on the CPU (e.g. setting bus speed & slave address).
2691 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2693 This option enables configuration of bi_iic_fast[] flags
2694 in u-boot bd_info structure based on u-boot environment
2695 variable "i2cfast". (see also i2cfast)
2697 CONFIG_I2C_MULTI_BUS
2699 This option allows the use of multiple I2C buses, each of which
2700 must have a controller. At any point in time, only one bus is
2701 active. To switch to a different bus, use the 'i2c dev' command.
2702 Note that bus numbering is zero-based.
2704 CONFIG_SYS_I2C_NOPROBES
2706 This option specifies a list of I2C devices that will be skipped
2707 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2708 is set, specify a list of bus-device pairs. Otherwise, specify
2709 a 1D array of device addresses
2712 #undef CONFIG_I2C_MULTI_BUS
2713 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2715 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2717 #define CONFIG_I2C_MULTI_BUS
2718 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2720 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2722 CONFIG_SYS_SPD_BUS_NUM
2724 If defined, then this indicates the I2C bus number for DDR SPD.
2725 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2727 CONFIG_SYS_RTC_BUS_NUM
2729 If defined, then this indicates the I2C bus number for the RTC.
2730 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2732 CONFIG_SYS_DTT_BUS_NUM
2734 If defined, then this indicates the I2C bus number for the DTT.
2735 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2737 CONFIG_SYS_I2C_DTT_ADDR:
2739 If defined, specifies the I2C address of the DTT device.
2740 If not defined, then U-Boot uses predefined value for
2741 specified DTT device.
2743 CONFIG_SOFT_I2C_READ_REPEATED_START
2745 defining this will force the i2c_read() function in
2746 the soft_i2c driver to perform an I2C repeated start
2747 between writing the address pointer and reading the
2748 data. If this define is omitted the default behaviour
2749 of doing a stop-start sequence will be used. Most I2C
2750 devices can use either method, but some require one or
2753 - SPI Support: CONFIG_SPI
2755 Enables SPI driver (so far only tested with
2756 SPI EEPROM, also an instance works with Crystal A/D and
2757 D/As on the SACSng board)
2761 Enables the driver for SPI controller on SuperH. Currently
2762 only SH7757 is supported.
2766 Enables extended (16-bit) SPI EEPROM addressing.
2767 (symmetrical to CONFIG_I2C_X)
2771 Enables a software (bit-bang) SPI driver rather than
2772 using hardware support. This is a general purpose
2773 driver that only requires three general I/O port pins
2774 (two outputs, one input) to function. If this is
2775 defined, the board configuration must define several
2776 SPI configuration items (port pins to use, etc). For
2777 an example, see include/configs/sacsng.h.
2781 Enables a hardware SPI driver for general-purpose reads
2782 and writes. As with CONFIG_SOFT_SPI, the board configuration
2783 must define a list of chip-select function pointers.
2784 Currently supported on some MPC8xxx processors. For an
2785 example, see include/configs/mpc8349emds.h.
2789 Enables the driver for the SPI controllers on i.MX and MXC
2790 SoCs. Currently i.MX31/35/51 are supported.
2792 CONFIG_SYS_SPI_MXC_WAIT
2793 Timeout for waiting until spi transfer completed.
2794 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2796 - FPGA Support: CONFIG_FPGA
2798 Enables FPGA subsystem.
2800 CONFIG_FPGA_<vendor>
2802 Enables support for specific chip vendors.
2805 CONFIG_FPGA_<family>
2807 Enables support for FPGA family.
2808 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2812 Specify the number of FPGA devices to support.
2814 CONFIG_CMD_FPGA_LOADMK
2816 Enable support for fpga loadmk command
2818 CONFIG_CMD_FPGA_LOADP
2820 Enable support for fpga loadp command - load partial bitstream
2822 CONFIG_CMD_FPGA_LOADBP
2824 Enable support for fpga loadbp command - load partial bitstream
2827 CONFIG_SYS_FPGA_PROG_FEEDBACK
2829 Enable printing of hash marks during FPGA configuration.
2831 CONFIG_SYS_FPGA_CHECK_BUSY
2833 Enable checks on FPGA configuration interface busy
2834 status by the configuration function. This option
2835 will require a board or device specific function to
2840 If defined, a function that provides delays in the FPGA
2841 configuration driver.
2843 CONFIG_SYS_FPGA_CHECK_CTRLC
2844 Allow Control-C to interrupt FPGA configuration
2846 CONFIG_SYS_FPGA_CHECK_ERROR
2848 Check for configuration errors during FPGA bitfile
2849 loading. For example, abort during Virtex II
2850 configuration if the INIT_B line goes low (which
2851 indicated a CRC error).
2853 CONFIG_SYS_FPGA_WAIT_INIT
2855 Maximum time to wait for the INIT_B line to de-assert
2856 after PROB_B has been de-asserted during a Virtex II
2857 FPGA configuration sequence. The default time is 500
2860 CONFIG_SYS_FPGA_WAIT_BUSY
2862 Maximum time to wait for BUSY to de-assert during
2863 Virtex II FPGA configuration. The default is 5 ms.
2865 CONFIG_SYS_FPGA_WAIT_CONFIG
2867 Time to wait after FPGA configuration. The default is
2870 - Configuration Management:
2873 Some SoCs need special image types (e.g. U-Boot binary
2874 with a special header) as build targets. By defining
2875 CONFIG_BUILD_TARGET in the SoC / board header, this
2876 special image will be automatically built upon calling
2881 If defined, this string will be added to the U-Boot
2882 version information (U_BOOT_VERSION)
2884 - Vendor Parameter Protection:
2886 U-Boot considers the values of the environment
2887 variables "serial#" (Board Serial Number) and
2888 "ethaddr" (Ethernet Address) to be parameters that
2889 are set once by the board vendor / manufacturer, and
2890 protects these variables from casual modification by
2891 the user. Once set, these variables are read-only,
2892 and write or delete attempts are rejected. You can
2893 change this behaviour:
2895 If CONFIG_ENV_OVERWRITE is #defined in your config
2896 file, the write protection for vendor parameters is
2897 completely disabled. Anybody can change or delete
2900 Alternatively, if you #define _both_ CONFIG_ETHADDR
2901 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2902 Ethernet address is installed in the environment,
2903 which can be changed exactly ONCE by the user. [The
2904 serial# is unaffected by this, i. e. it remains
2907 The same can be accomplished in a more flexible way
2908 for any variable by configuring the type of access
2909 to allow for those variables in the ".flags" variable
2910 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2915 Define this variable to enable the reservation of
2916 "protected RAM", i. e. RAM which is not overwritten
2917 by U-Boot. Define CONFIG_PRAM to hold the number of
2918 kB you want to reserve for pRAM. You can overwrite
2919 this default value by defining an environment
2920 variable "pram" to the number of kB you want to
2921 reserve. Note that the board info structure will
2922 still show the full amount of RAM. If pRAM is
2923 reserved, a new environment variable "mem" will
2924 automatically be defined to hold the amount of
2925 remaining RAM in a form that can be passed as boot
2926 argument to Linux, for instance like that:
2928 setenv bootargs ... mem=\${mem}
2931 This way you can tell Linux not to use this memory,
2932 either, which results in a memory region that will
2933 not be affected by reboots.
2935 *WARNING* If your board configuration uses automatic
2936 detection of the RAM size, you must make sure that
2937 this memory test is non-destructive. So far, the
2938 following board configurations are known to be
2941 IVMS8, IVML24, SPD8xx, TQM8xxL,
2942 HERMES, IP860, RPXlite, LWMON,
2945 - Access to physical memory region (> 4GB)
2946 Some basic support is provided for operations on memory not
2947 normally accessible to U-Boot - e.g. some architectures
2948 support access to more than 4GB of memory on 32-bit
2949 machines using physical address extension or similar.
2950 Define CONFIG_PHYSMEM to access this basic support, which
2951 currently only supports clearing the memory.
2956 Define this variable to stop the system in case of a
2957 fatal error, so that you have to reset it manually.
2958 This is probably NOT a good idea for an embedded
2959 system where you want the system to reboot
2960 automatically as fast as possible, but it may be
2961 useful during development since you can try to debug
2962 the conditions that lead to the situation.
2964 CONFIG_NET_RETRY_COUNT
2966 This variable defines the number of retries for
2967 network operations like ARP, RARP, TFTP, or BOOTP
2968 before giving up the operation. If not defined, a
2969 default value of 5 is used.
2973 Timeout waiting for an ARP reply in milliseconds.
2977 Timeout in milliseconds used in NFS protocol.
2978 If you encounter "ERROR: Cannot umount" in nfs command,
2979 try longer timeout such as
2980 #define CONFIG_NFS_TIMEOUT 10000UL
2982 - Command Interpreter:
2983 CONFIG_AUTO_COMPLETE
2985 Enable auto completion of commands using TAB.
2987 CONFIG_SYS_PROMPT_HUSH_PS2
2989 This defines the secondary prompt string, which is
2990 printed when the command interpreter needs more input
2991 to complete a command. Usually "> ".
2995 In the current implementation, the local variables
2996 space and global environment variables space are
2997 separated. Local variables are those you define by
2998 simply typing `name=value'. To access a local
2999 variable later on, you have write `$name' or
3000 `${name}'; to execute the contents of a variable
3001 directly type `$name' at the command prompt.
3003 Global environment variables are those you use
3004 setenv/printenv to work with. To run a command stored
3005 in such a variable, you need to use the run command,
3006 and you must not use the '$' sign to access them.
3008 To store commands and special characters in a
3009 variable, please use double quotation marks
3010 surrounding the whole text of the variable, instead
3011 of the backslashes before semicolons and special
3014 - Command Line Editing and History:
3015 CONFIG_CMDLINE_EDITING
3017 Enable editing and History functions for interactive
3018 command line input operations
3020 - Default Environment:
3021 CONFIG_EXTRA_ENV_SETTINGS
3023 Define this to contain any number of null terminated
3024 strings (variable = value pairs) that will be part of
3025 the default environment compiled into the boot image.
3027 For example, place something like this in your
3028 board's config file:
3030 #define CONFIG_EXTRA_ENV_SETTINGS \
3034 Warning: This method is based on knowledge about the
3035 internal format how the environment is stored by the
3036 U-Boot code. This is NOT an official, exported
3037 interface! Although it is unlikely that this format
3038 will change soon, there is no guarantee either.
3039 You better know what you are doing here.
3041 Note: overly (ab)use of the default environment is
3042 discouraged. Make sure to check other ways to preset
3043 the environment like the "source" command or the
3046 CONFIG_ENV_VARS_UBOOT_CONFIG
3048 Define this in order to add variables describing the
3049 U-Boot build configuration to the default environment.
3050 These will be named arch, cpu, board, vendor, and soc.
3052 Enabling this option will cause the following to be defined:
3060 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3062 Define this in order to add variables describing certain
3063 run-time determined information about the hardware to the
3064 environment. These will be named board_name, board_rev.
3066 CONFIG_DELAY_ENVIRONMENT
3068 Normally the environment is loaded when the board is
3069 initialised so that it is available to U-Boot. This inhibits
3070 that so that the environment is not available until
3071 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3072 this is instead controlled by the value of
3073 /config/load-environment.
3075 - DataFlash Support:
3076 CONFIG_HAS_DATAFLASH
3078 Defining this option enables DataFlash features and
3079 allows to read/write in Dataflash via the standard
3082 - Serial Flash support
3085 Defining this option enables SPI flash commands
3086 'sf probe/read/write/erase/update'.
3088 Usage requires an initial 'probe' to define the serial
3089 flash parameters, followed by read/write/erase/update
3092 The following defaults may be provided by the platform
3093 to handle the common case when only a single serial
3094 flash is present on the system.
3096 CONFIG_SF_DEFAULT_BUS Bus identifier
3097 CONFIG_SF_DEFAULT_CS Chip-select
3098 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3099 CONFIG_SF_DEFAULT_SPEED in Hz
3103 Define this option to include a destructive SPI flash
3106 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3108 Define this option to use the Bank addr/Extended addr
3109 support on SPI flashes which has size > 16Mbytes.
3111 CONFIG_SF_DUAL_FLASH Dual flash memories
3113 Define this option to use dual flash support where two flash
3114 memories can be connected with a given cs line.
3115 Currently Xilinx Zynq qspi supports these type of connections.
3117 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3118 enable the W#/Vpp signal to disable writing to the status
3119 register on ST MICRON flashes like the N25Q128.
3120 The status register write enable/disable bit, combined with
3121 the W#/VPP signal provides hardware data protection for the
3122 device as follows: When the enable/disable bit is set to 1,
3123 and the W#/VPP signal is driven LOW, the status register
3124 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3125 operation will not execute. The only way to exit this
3126 hardware-protected mode is to drive W#/VPP HIGH.
3128 - SystemACE Support:
3131 Adding this option adds support for Xilinx SystemACE
3132 chips attached via some sort of local bus. The address
3133 of the chip must also be defined in the
3134 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3136 #define CONFIG_SYSTEMACE
3137 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3139 When SystemACE support is added, the "ace" device type
3140 becomes available to the fat commands, i.e. fatls.
3142 - TFTP Fixed UDP Port:
3145 If this is defined, the environment variable tftpsrcp
3146 is used to supply the TFTP UDP source port value.
3147 If tftpsrcp isn't defined, the normal pseudo-random port
3148 number generator is used.
3150 Also, the environment variable tftpdstp is used to supply
3151 the TFTP UDP destination port value. If tftpdstp isn't
3152 defined, the normal port 69 is used.
3154 The purpose for tftpsrcp is to allow a TFTP server to
3155 blindly start the TFTP transfer using the pre-configured
3156 target IP address and UDP port. This has the effect of
3157 "punching through" the (Windows XP) firewall, allowing
3158 the remainder of the TFTP transfer to proceed normally.
3159 A better solution is to properly configure the firewall,
3160 but sometimes that is not allowed.
3165 This enables a generic 'hash' command which can produce
3166 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3170 Enable the hash verify command (hash -v). This adds to code
3173 CONFIG_SHA1 - This option enables support of hashing using SHA1
3174 algorithm. The hash is calculated in software.
3175 CONFIG_SHA256 - This option enables support of hashing using
3176 SHA256 algorithm. The hash is calculated in software.
3177 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3178 for SHA1/SHA256 hashing.
3179 This affects the 'hash' command and also the
3180 hash_lookup_algo() function.
3181 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3182 hardware-acceleration for SHA1/SHA256 progressive hashing.
3183 Data can be streamed in a block at a time and the hashing
3184 is performed in hardware.
3186 Note: There is also a sha1sum command, which should perhaps
3187 be deprecated in favour of 'hash sha1'.
3189 - Freescale i.MX specific commands:
3190 CONFIG_CMD_HDMIDETECT
3191 This enables 'hdmidet' command which returns true if an
3192 HDMI monitor is detected. This command is i.MX 6 specific.
3195 This enables the 'bmode' (bootmode) command for forcing
3196 a boot from specific media.
3198 This is useful for forcing the ROM's usb downloader to
3199 activate upon a watchdog reset which is nice when iterating
3200 on U-Boot. Using the reset button or running bmode normal
3201 will set it back to normal. This command currently
3202 supports i.MX53 and i.MX6.
3207 This enables the RSA algorithm used for FIT image verification
3208 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3210 The Modular Exponentiation algorithm in RSA is implemented using
3211 driver model. So CONFIG_DM needs to be enabled by default for this
3212 library to function.
3214 The signing part is build into mkimage regardless of this
3215 option. The software based modular exponentiation is built into
3216 mkimage irrespective of this option.
3218 - bootcount support:
3219 CONFIG_BOOTCOUNT_LIMIT
3221 This enables the bootcounter support, see:
3222 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3225 enable special bootcounter support on at91sam9xe based boards.
3227 enable special bootcounter support on blackfin based boards.
3229 enable special bootcounter support on da850 based boards.
3230 CONFIG_BOOTCOUNT_RAM
3231 enable support for the bootcounter in RAM
3232 CONFIG_BOOTCOUNT_I2C
3233 enable support for the bootcounter on an i2c (like RTC) device.
3234 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3235 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3237 CONFIG_BOOTCOUNT_ALEN = address len
3239 - Show boot progress:
3240 CONFIG_SHOW_BOOT_PROGRESS
3242 Defining this option allows to add some board-
3243 specific code (calling a user-provided function
3244 "show_boot_progress(int)") that enables you to show
3245 the system's boot progress on some display (for
3246 example, some LED's) on your board. At the moment,
3247 the following checkpoints are implemented:
3249 - Detailed boot stage timing
3251 Define this option to get detailed timing of each stage
3252 of the boot process.
3254 CONFIG_BOOTSTAGE_USER_COUNT
3255 This is the number of available user bootstage records.
3256 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3257 a new ID will be allocated from this stash. If you exceed
3258 the limit, recording will stop.
3260 CONFIG_BOOTSTAGE_REPORT
3261 Define this to print a report before boot, similar to this:
3263 Timer summary in microseconds:
3266 3,575,678 3,575,678 board_init_f start
3267 3,575,695 17 arch_cpu_init A9
3268 3,575,777 82 arch_cpu_init done
3269 3,659,598 83,821 board_init_r start
3270 3,910,375 250,777 main_loop
3271 29,916,167 26,005,792 bootm_start
3272 30,361,327 445,160 start_kernel
3274 CONFIG_CMD_BOOTSTAGE
3275 Add a 'bootstage' command which supports printing a report
3276 and un/stashing of bootstage data.
3278 CONFIG_BOOTSTAGE_FDT
3279 Stash the bootstage information in the FDT. A root 'bootstage'
3280 node is created with each bootstage id as a child. Each child
3281 has a 'name' property and either 'mark' containing the
3282 mark time in microsecond, or 'accum' containing the
3283 accumulated time for that bootstage id in microseconds.
3288 name = "board_init_f";
3297 Code in the Linux kernel can find this in /proc/devicetree.
3299 Legacy uImage format:
3302 1 common/cmd_bootm.c before attempting to boot an image
3303 -1 common/cmd_bootm.c Image header has bad magic number
3304 2 common/cmd_bootm.c Image header has correct magic number
3305 -2 common/cmd_bootm.c Image header has bad checksum
3306 3 common/cmd_bootm.c Image header has correct checksum
3307 -3 common/cmd_bootm.c Image data has bad checksum
3308 4 common/cmd_bootm.c Image data has correct checksum
3309 -4 common/cmd_bootm.c Image is for unsupported architecture
3310 5 common/cmd_bootm.c Architecture check OK
3311 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3312 6 common/cmd_bootm.c Image Type check OK
3313 -6 common/cmd_bootm.c gunzip uncompression error
3314 -7 common/cmd_bootm.c Unimplemented compression type
3315 7 common/cmd_bootm.c Uncompression OK
3316 8 common/cmd_bootm.c No uncompress/copy overwrite error
3317 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3319 9 common/image.c Start initial ramdisk verification
3320 -10 common/image.c Ramdisk header has bad magic number
3321 -11 common/image.c Ramdisk header has bad checksum
3322 10 common/image.c Ramdisk header is OK
3323 -12 common/image.c Ramdisk data has bad checksum
3324 11 common/image.c Ramdisk data has correct checksum
3325 12 common/image.c Ramdisk verification complete, start loading
3326 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3327 13 common/image.c Start multifile image verification
3328 14 common/image.c No initial ramdisk, no multifile, continue.
3330 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3332 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3333 -31 post/post.c POST test failed, detected by post_output_backlog()
3334 -32 post/post.c POST test failed, detected by post_run_single()
3336 34 common/cmd_doc.c before loading a Image from a DOC device
3337 -35 common/cmd_doc.c Bad usage of "doc" command
3338 35 common/cmd_doc.c correct usage of "doc" command
3339 -36 common/cmd_doc.c No boot device
3340 36 common/cmd_doc.c correct boot device
3341 -37 common/cmd_doc.c Unknown Chip ID on boot device
3342 37 common/cmd_doc.c correct chip ID found, device available
3343 -38 common/cmd_doc.c Read Error on boot device
3344 38 common/cmd_doc.c reading Image header from DOC device OK
3345 -39 common/cmd_doc.c Image header has bad magic number
3346 39 common/cmd_doc.c Image header has correct magic number
3347 -40 common/cmd_doc.c Error reading Image from DOC device
3348 40 common/cmd_doc.c Image header has correct magic number
3349 41 common/cmd_ide.c before loading a Image from a IDE device
3350 -42 common/cmd_ide.c Bad usage of "ide" command
3351 42 common/cmd_ide.c correct usage of "ide" command
3352 -43 common/cmd_ide.c No boot device
3353 43 common/cmd_ide.c boot device found
3354 -44 common/cmd_ide.c Device not available
3355 44 common/cmd_ide.c Device available
3356 -45 common/cmd_ide.c wrong partition selected
3357 45 common/cmd_ide.c partition selected
3358 -46 common/cmd_ide.c Unknown partition table
3359 46 common/cmd_ide.c valid partition table found
3360 -47 common/cmd_ide.c Invalid partition type
3361 47 common/cmd_ide.c correct partition type
3362 -48 common/cmd_ide.c Error reading Image Header on boot device
3363 48 common/cmd_ide.c reading Image Header from IDE device OK
3364 -49 common/cmd_ide.c Image header has bad magic number
3365 49 common/cmd_ide.c Image header has correct magic number
3366 -50 common/cmd_ide.c Image header has bad checksum
3367 50 common/cmd_ide.c Image header has correct checksum
3368 -51 common/cmd_ide.c Error reading Image from IDE device
3369 51 common/cmd_ide.c reading Image from IDE device OK
3370 52 common/cmd_nand.c before loading a Image from a NAND device
3371 -53 common/cmd_nand.c Bad usage of "nand" command
3372 53 common/cmd_nand.c correct usage of "nand" command
3373 -54 common/cmd_nand.c No boot device
3374 54 common/cmd_nand.c boot device found
3375 -55 common/cmd_nand.c Unknown Chip ID on boot device
3376 55 common/cmd_nand.c correct chip ID found, device available
3377 -56 common/cmd_nand.c Error reading Image Header on boot device
3378 56 common/cmd_nand.c reading Image Header from NAND device OK
3379 -57 common/cmd_nand.c Image header has bad magic number
3380 57 common/cmd_nand.c Image header has correct magic number
3381 -58 common/cmd_nand.c Error reading Image from NAND device
3382 58 common/cmd_nand.c reading Image from NAND device OK
3384 -60 common/env_common.c Environment has a bad CRC, using default
3386 64 net/eth.c starting with Ethernet configuration.
3387 -64 net/eth.c no Ethernet found.
3388 65 net/eth.c Ethernet found.
3390 -80 common/cmd_net.c usage wrong
3391 80 common/cmd_net.c before calling NetLoop()
3392 -81 common/cmd_net.c some error in NetLoop() occurred
3393 81 common/cmd_net.c NetLoop() back without error
3394 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3395 82 common/cmd_net.c trying automatic boot
3396 83 common/cmd_net.c running "source" command
3397 -83 common/cmd_net.c some error in automatic boot or "source" command
3398 84 common/cmd_net.c end without errors
3403 100 common/cmd_bootm.c Kernel FIT Image has correct format
3404 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3405 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3406 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3407 102 common/cmd_bootm.c Kernel unit name specified
3408 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3409 103 common/cmd_bootm.c Found configuration node
3410 104 common/cmd_bootm.c Got kernel subimage node offset
3411 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3412 105 common/cmd_bootm.c Kernel subimage hash verification OK
3413 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3414 106 common/cmd_bootm.c Architecture check OK
3415 -106 common/cmd_bootm.c Kernel subimage has wrong type
3416 107 common/cmd_bootm.c Kernel subimage type OK
3417 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3418 108 common/cmd_bootm.c Got kernel subimage data/size
3419 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3420 -109 common/cmd_bootm.c Can't get kernel subimage type
3421 -110 common/cmd_bootm.c Can't get kernel subimage comp
3422 -111 common/cmd_bootm.c Can't get kernel subimage os
3423 -112 common/cmd_bootm.c Can't get kernel subimage load address
3424 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3426 120 common/image.c Start initial ramdisk verification
3427 -120 common/image.c Ramdisk FIT image has incorrect format
3428 121 common/image.c Ramdisk FIT image has correct format
3429 122 common/image.c No ramdisk subimage unit name, using configuration
3430 -122 common/image.c Can't get configuration for ramdisk subimage
3431 123 common/image.c Ramdisk unit name specified
3432 -124 common/image.c Can't get ramdisk subimage node offset
3433 125 common/image.c Got ramdisk subimage node offset
3434 -125 common/image.c Ramdisk subimage hash verification failed
3435 126 common/image.c Ramdisk subimage hash verification OK
3436 -126 common/image.c Ramdisk subimage for unsupported architecture
3437 127 common/image.c Architecture check OK
3438 -127 common/image.c Can't get ramdisk subimage data/size
3439 128 common/image.c Got ramdisk subimage data/size
3440 129 common/image.c Can't get ramdisk load address
3441 -129 common/image.c Got ramdisk load address
3443 -130 common/cmd_doc.c Incorrect FIT image format
3444 131 common/cmd_doc.c FIT image format OK
3446 -140 common/cmd_ide.c Incorrect FIT image format
3447 141 common/cmd_ide.c FIT image format OK
3449 -150 common/cmd_nand.c Incorrect FIT image format
3450 151 common/cmd_nand.c FIT image format OK
3452 - legacy image format:
3453 CONFIG_IMAGE_FORMAT_LEGACY
3454 enables the legacy image format support in U-Boot.
3457 enabled if CONFIG_FIT_SIGNATURE is not defined.
3459 CONFIG_DISABLE_IMAGE_LEGACY
3460 disable the legacy image format
3462 This define is introduced, as the legacy image format is
3463 enabled per default for backward compatibility.
3465 - FIT image support:
3467 Enable support for the FIT uImage format.
3469 CONFIG_FIT_BEST_MATCH
3470 When no configuration is explicitly selected, default to the
3471 one whose fdt's compatibility field best matches that of
3472 U-Boot itself. A match is considered "best" if it matches the
3473 most specific compatibility entry of U-Boot's fdt's root node.
3474 The order of entries in the configuration's fdt is ignored.
3476 CONFIG_FIT_SIGNATURE
3477 This option enables signature verification of FIT uImages,
3478 using a hash signed and verified using RSA. If
3479 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3480 hashing is available using hardware, RSA library will use it.
3481 See doc/uImage.FIT/signature.txt for more details.
3483 WARNING: When relying on signed FIT images with required
3484 signature check the legacy image format is default
3485 disabled. If a board need legacy image format support
3486 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3488 CONFIG_FIT_DISABLE_SHA256
3489 Supporting SHA256 hashes has quite an impact on binary size.
3490 For constrained systems sha256 hash support can be disabled
3493 - Standalone program support:
3494 CONFIG_STANDALONE_LOAD_ADDR
3496 This option defines a board specific value for the
3497 address where standalone program gets loaded, thus
3498 overwriting the architecture dependent default
3501 - Frame Buffer Address:
3504 Define CONFIG_FB_ADDR if you want to use specific
3505 address for frame buffer. This is typically the case
3506 when using a graphics controller has separate video
3507 memory. U-Boot will then place the frame buffer at
3508 the given address instead of dynamically reserving it
3509 in system RAM by calling lcd_setmem(), which grabs
3510 the memory for the frame buffer depending on the
3511 configured panel size.
3513 Please see board_init_f function.
3515 - Automatic software updates via TFTP server
3517 CONFIG_UPDATE_TFTP_CNT_MAX
3518 CONFIG_UPDATE_TFTP_MSEC_MAX
3520 These options enable and control the auto-update feature;
3521 for a more detailed description refer to doc/README.update.
3523 - MTD Support (mtdparts command, UBI support)
3526 Adds the MTD device infrastructure from the Linux kernel.
3527 Needed for mtdparts command support.
3529 CONFIG_MTD_PARTITIONS
3531 Adds the MTD partitioning infrastructure from the Linux
3532 kernel. Needed for UBI support.
3534 CONFIG_MTD_NAND_VERIFY_WRITE
3535 verify if the written data is correct reread.
3540 Adds commands for interacting with MTD partitions formatted
3541 with the UBI flash translation layer
3543 Requires also defining CONFIG_RBTREE
3545 CONFIG_UBI_SILENCE_MSG
3547 Make the verbose messages from UBI stop printing. This leaves
3548 warnings and errors enabled.
3551 CONFIG_MTD_UBI_WL_THRESHOLD
3552 This parameter defines the maximum difference between the highest
3553 erase counter value and the lowest erase counter value of eraseblocks
3554 of UBI devices. When this threshold is exceeded, UBI starts performing
3555 wear leveling by means of moving data from eraseblock with low erase
3556 counter to eraseblocks with high erase counter.
3558 The default value should be OK for SLC NAND flashes, NOR flashes and
3559 other flashes which have eraseblock life-cycle 100000 or more.
3560 However, in case of MLC NAND flashes which typically have eraseblock
3561 life-cycle less than 10000, the threshold should be lessened (e.g.,
3562 to 128 or 256, although it does not have to be power of 2).
3566 CONFIG_MTD_UBI_BEB_LIMIT
3567 This option specifies the maximum bad physical eraseblocks UBI
3568 expects on the MTD device (per 1024 eraseblocks). If the
3569 underlying flash does not admit of bad eraseblocks (e.g. NOR
3570 flash), this value is ignored.
3572 NAND datasheets often specify the minimum and maximum NVM
3573 (Number of Valid Blocks) for the flashes' endurance lifetime.
3574 The maximum expected bad eraseblocks per 1024 eraseblocks
3575 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3576 which gives 20 for most NANDs (MaxNVB is basically the total
3577 count of eraseblocks on the chip).
3579 To put it differently, if this value is 20, UBI will try to
3580 reserve about 1.9% of physical eraseblocks for bad blocks
3581 handling. And that will be 1.9% of eraseblocks on the entire
3582 NAND chip, not just the MTD partition UBI attaches. This means
3583 that if you have, say, a NAND flash chip admits maximum 40 bad
3584 eraseblocks, and it is split on two MTD partitions of the same
3585 size, UBI will reserve 40 eraseblocks when attaching a
3590 CONFIG_MTD_UBI_FASTMAP
3591 Fastmap is a mechanism which allows attaching an UBI device
3592 in nearly constant time. Instead of scanning the whole MTD device it
3593 only has to locate a checkpoint (called fastmap) on the device.
3594 The on-flash fastmap contains all information needed to attach
3595 the device. Using fastmap makes only sense on large devices where
3596 attaching by scanning takes long. UBI will not automatically install
3597 a fastmap on old images, but you can set the UBI parameter
3598 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3599 that fastmap-enabled images are still usable with UBI implementations
3600 without fastmap support. On typical flash devices the whole fastmap
3601 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3603 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3604 Set this parameter to enable fastmap automatically on images
3611 Adds commands for interacting with UBI volumes formatted as
3612 UBIFS. UBIFS is read-only in u-boot.
3614 Requires UBI support as well as CONFIG_LZO
3616 CONFIG_UBIFS_SILENCE_MSG
3618 Make the verbose messages from UBIFS stop printing. This leaves
3619 warnings and errors enabled.
3623 Enable building of SPL globally.
3626 LDSCRIPT for linking the SPL binary.
3628 CONFIG_SPL_MAX_FOOTPRINT
3629 Maximum size in memory allocated to the SPL, BSS included.
3630 When defined, the linker checks that the actual memory
3631 used by SPL from _start to __bss_end does not exceed it.
3632 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3633 must not be both defined at the same time.
3636 Maximum size of the SPL image (text, data, rodata, and
3637 linker lists sections), BSS excluded.
3638 When defined, the linker checks that the actual size does
3641 CONFIG_SPL_TEXT_BASE
3642 TEXT_BASE for linking the SPL binary.
3644 CONFIG_SPL_RELOC_TEXT_BASE
3645 Address to relocate to. If unspecified, this is equal to
3646 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3648 CONFIG_SPL_BSS_START_ADDR
3649 Link address for the BSS within the SPL binary.
3651 CONFIG_SPL_BSS_MAX_SIZE
3652 Maximum size in memory allocated to the SPL BSS.
3653 When defined, the linker checks that the actual memory used
3654 by SPL from __bss_start to __bss_end does not exceed it.
3655 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3656 must not be both defined at the same time.
3659 Adress of the start of the stack SPL will use
3661 CONFIG_SPL_RELOC_STACK
3662 Adress of the start of the stack SPL will use after
3663 relocation. If unspecified, this is equal to
3666 CONFIG_SYS_SPL_MALLOC_START
3667 Starting address of the malloc pool used in SPL.
3669 CONFIG_SYS_SPL_MALLOC_SIZE
3670 The size of the malloc pool used in SPL.
3672 CONFIG_SPL_FRAMEWORK
3673 Enable the SPL framework under common/. This framework
3674 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3675 NAND loading of the Linux Kernel.
3678 Enable booting directly to an OS from SPL.
3679 See also: doc/README.falcon
3681 CONFIG_SPL_DISPLAY_PRINT
3682 For ARM, enable an optional function to print more information
3683 about the running system.
3685 CONFIG_SPL_INIT_MINIMAL
3686 Arch init code should be built for a very small image
3688 CONFIG_SPL_LIBCOMMON_SUPPORT
3689 Support for common/libcommon.o in SPL binary
3691 CONFIG_SPL_LIBDISK_SUPPORT
3692 Support for disk/libdisk.o in SPL binary
3694 CONFIG_SPL_I2C_SUPPORT
3695 Support for drivers/i2c/libi2c.o in SPL binary
3697 CONFIG_SPL_GPIO_SUPPORT
3698 Support for drivers/gpio/libgpio.o in SPL binary
3700 CONFIG_SPL_MMC_SUPPORT
3701 Support for drivers/mmc/libmmc.o in SPL binary
3703 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3704 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3705 Address and partition on the MMC to load U-Boot from
3706 when the MMC is being used in raw mode.
3708 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3709 Partition on the MMC to load U-Boot from when the MMC is being
3712 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3713 Sector to load kernel uImage from when MMC is being
3714 used in raw mode (for Falcon mode)
3716 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3717 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3718 Sector and number of sectors to load kernel argument
3719 parameters from when MMC is being used in raw mode
3722 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3723 Partition on the MMC to load U-Boot from when the MMC is being
3726 CONFIG_SPL_FAT_SUPPORT
3727 Support for fs/fat/libfat.o in SPL binary
3729 CONFIG_SPL_EXT_SUPPORT
3730 Support for EXT filesystem in SPL binary
3732 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3733 Filename to read to load U-Boot when reading from filesystem
3735 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3736 Filename to read to load kernel uImage when reading
3737 from filesystem (for Falcon mode)
3739 CONFIG_SPL_FS_LOAD_ARGS_NAME
3740 Filename to read to load kernel argument parameters
3741 when reading from filesystem (for Falcon mode)
3743 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3744 Set this for NAND SPL on PPC mpc83xx targets, so that
3745 start.S waits for the rest of the SPL to load before
3746 continuing (the hardware starts execution after just
3747 loading the first page rather than the full 4K).
3749 CONFIG_SPL_SKIP_RELOCATE
3750 Avoid SPL relocation
3752 CONFIG_SPL_NAND_BASE
3753 Include nand_base.c in the SPL. Requires
3754 CONFIG_SPL_NAND_DRIVERS.
3756 CONFIG_SPL_NAND_DRIVERS
3757 SPL uses normal NAND drivers, not minimal drivers.
3760 Include standard software ECC in the SPL
3762 CONFIG_SPL_NAND_SIMPLE
3763 Support for NAND boot using simple NAND drivers that
3764 expose the cmd_ctrl() interface.
3766 CONFIG_SPL_MTD_SUPPORT
3767 Support for the MTD subsystem within SPL. Useful for
3768 environment on NAND support within SPL.
3770 CONFIG_SPL_NAND_RAW_ONLY
3771 Support to boot only raw u-boot.bin images. Use this only
3772 if you need to save space.
3774 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3775 Set for the SPL on PPC mpc8xxx targets, support for
3776 drivers/ddr/fsl/libddr.o in SPL binary.
3778 CONFIG_SPL_COMMON_INIT_DDR
3779 Set for common ddr init with serial presence detect in
3782 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3783 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3784 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3785 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3786 CONFIG_SYS_NAND_ECCBYTES
3787 Defines the size and behavior of the NAND that SPL uses
3790 CONFIG_SPL_NAND_BOOT
3791 Add support NAND boot
3793 CONFIG_SYS_NAND_U_BOOT_OFFS
3794 Location in NAND to read U-Boot from
3796 CONFIG_SYS_NAND_U_BOOT_DST
3797 Location in memory to load U-Boot to
3799 CONFIG_SYS_NAND_U_BOOT_SIZE
3800 Size of image to load
3802 CONFIG_SYS_NAND_U_BOOT_START
3803 Entry point in loaded image to jump to
3805 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3806 Define this if you need to first read the OOB and then the
3807 data. This is used, for example, on davinci platforms.
3809 CONFIG_SPL_OMAP3_ID_NAND
3810 Support for an OMAP3-specific set of functions to return the
3811 ID and MFR of the first attached NAND chip, if present.
3813 CONFIG_SPL_SERIAL_SUPPORT
3814 Support for drivers/serial/libserial.o in SPL binary
3816 CONFIG_SPL_SPI_FLASH_SUPPORT
3817 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3819 CONFIG_SPL_SPI_SUPPORT
3820 Support for drivers/spi/libspi.o in SPL binary
3822 CONFIG_SPL_RAM_DEVICE
3823 Support for running image already present in ram, in SPL binary
3825 CONFIG_SPL_LIBGENERIC_SUPPORT
3826 Support for lib/libgeneric.o in SPL binary
3828 CONFIG_SPL_ENV_SUPPORT
3829 Support for the environment operating in SPL binary
3831 CONFIG_SPL_NET_SUPPORT
3832 Support for the net/libnet.o in SPL binary.
3833 It conflicts with SPL env from storage medium specified by
3834 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3837 Image offset to which the SPL should be padded before appending
3838 the SPL payload. By default, this is defined as
3839 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3840 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3841 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3844 Final target image containing SPL and payload. Some SPLs
3845 use an arch-specific makefile fragment instead, for
3846 example if more than one image needs to be produced.
3848 CONFIG_FIT_SPL_PRINT
3849 Printing information about a FIT image adds quite a bit of
3850 code to SPL. So this is normally disabled in SPL. Use this
3851 option to re-enable it. This will affect the output of the
3852 bootm command when booting a FIT image.
3856 Enable building of TPL globally.
3859 Image offset to which the TPL should be padded before appending
3860 the TPL payload. By default, this is defined as
3861 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3862 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3863 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3868 [so far only for SMDK2400 boards]
3870 - Modem support enable:
3871 CONFIG_MODEM_SUPPORT
3873 - RTS/CTS Flow control enable:
3876 - Modem debug support:
3877 CONFIG_MODEM_SUPPORT_DEBUG
3879 Enables debugging stuff (char screen[1024], dbg())
3880 for modem support. Useful only with BDI2000.
3882 - Interrupt support (PPC):
3884 There are common interrupt_init() and timer_interrupt()
3885 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3886 for CPU specific initialization. interrupt_init_cpu()
3887 should set decrementer_count to appropriate value. If
3888 CPU resets decrementer automatically after interrupt
3889 (ppc4xx) it should set decrementer_count to zero.
3890 timer_interrupt() calls timer_interrupt_cpu() for CPU
3891 specific handling. If board has watchdog / status_led
3892 / other_activity_monitor it works automatically from
3893 general timer_interrupt().
3897 In the target system modem support is enabled when a
3898 specific key (key combination) is pressed during
3899 power-on. Otherwise U-Boot will boot normally
3900 (autoboot). The key_pressed() function is called from
3901 board_init(). Currently key_pressed() is a dummy
3902 function, returning 1 and thus enabling modem
3905 If there are no modem init strings in the
3906 environment, U-Boot proceed to autoboot; the
3907 previous output (banner, info printfs) will be
3910 See also: doc/README.Modem
3912 Board initialization settings:
3913 ------------------------------
3915 During Initialization u-boot calls a number of board specific functions
3916 to allow the preparation of board specific prerequisites, e.g. pin setup
3917 before drivers are initialized. To enable these callbacks the
3918 following configuration macros have to be defined. Currently this is
3919 architecture specific, so please check arch/your_architecture/lib/board.c
3920 typically in board_init_f() and board_init_r().
3922 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3923 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3924 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3925 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3927 Configuration Settings:
3928 -----------------------
3930 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3931 Optionally it can be defined to support 64-bit memory commands.
3933 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3934 undefine this when you're short of memory.
3936 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3937 width of the commands listed in the 'help' command output.
3939 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3940 prompt for user input.
3942 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3944 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3946 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3948 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3949 the application (usually a Linux kernel) when it is
3952 - CONFIG_SYS_BAUDRATE_TABLE:
3953 List of legal baudrate settings for this board.
3955 - CONFIG_SYS_CONSOLE_INFO_QUIET
3956 Suppress display of console information at boot.
3958 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3959 If the board specific function
3960 extern int overwrite_console (void);
3961 returns 1, the stdin, stderr and stdout are switched to the
3962 serial port, else the settings in the environment are used.
3964 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3965 Enable the call to overwrite_console().
3967 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3968 Enable overwrite of previous console environment settings.
3970 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3971 Begin and End addresses of the area used by the
3974 - CONFIG_SYS_ALT_MEMTEST:
3975 Enable an alternate, more extensive memory test.
3977 - CONFIG_SYS_MEMTEST_SCRATCH:
3978 Scratch address used by the alternate memory test
3979 You only need to set this if address zero isn't writeable
3981 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3982 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3983 this specified memory area will get subtracted from the top
3984 (end) of RAM and won't get "touched" at all by U-Boot. By
3985 fixing up gd->ram_size the Linux kernel should gets passed
3986 the now "corrected" memory size and won't touch it either.
3987 This should work for arch/ppc and arch/powerpc. Only Linux
3988 board ports in arch/powerpc with bootwrapper support that
3989 recalculate the memory size from the SDRAM controller setup
3990 will have to get fixed in Linux additionally.
3992 This option can be used as a workaround for the 440EPx/GRx
3993 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3996 WARNING: Please make sure that this value is a multiple of
3997 the Linux page size (normally 4k). If this is not the case,
3998 then the end address of the Linux memory will be located at a
3999 non page size aligned address and this could cause major
4002 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4003 Enable temporary baudrate change while serial download
4005 - CONFIG_SYS_SDRAM_BASE:
4006 Physical start address of SDRAM. _Must_ be 0 here.
4008 - CONFIG_SYS_MBIO_BASE:
4009 Physical start address of Motherboard I/O (if using a
4012 - CONFIG_SYS_FLASH_BASE:
4013 Physical start address of Flash memory.
4015 - CONFIG_SYS_MONITOR_BASE:
4016 Physical start address of boot monitor code (set by
4017 make config files to be same as the text base address
4018 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4019 CONFIG_SYS_FLASH_BASE when booting from flash.
4021 - CONFIG_SYS_MONITOR_LEN:
4022 Size of memory reserved for monitor code, used to
4023 determine _at_compile_time_ (!) if the environment is
4024 embedded within the U-Boot image, or in a separate
4027 - CONFIG_SYS_MALLOC_LEN:
4028 Size of DRAM reserved for malloc() use.
4030 - CONFIG_SYS_MALLOC_F_LEN
4031 Size of the malloc() pool for use before relocation. If
4032 this is defined, then a very simple malloc() implementation
4033 will become available before relocation. The address is just
4034 below the global data, and the stack is moved down to make
4037 This feature allocates regions with increasing addresses
4038 within the region. calloc() is supported, but realloc()
4039 is not available. free() is supported but does nothing.
4040 The memory will be freed (or in fact just forgotten) when
4041 U-Boot relocates itself.
4043 Pre-relocation malloc() is only supported on ARM and sandbox
4044 at present but is fairly easy to enable for other archs.
4046 - CONFIG_SYS_MALLOC_SIMPLE
4047 Provides a simple and small malloc() and calloc() for those
4048 boards which do not use the full malloc in SPL (which is
4049 enabled with CONFIG_SYS_SPL_MALLOC_START).
4051 - CONFIG_SYS_NONCACHED_MEMORY:
4052 Size of non-cached memory area. This area of memory will be
4053 typically located right below the malloc() area and mapped
4054 uncached in the MMU. This is useful for drivers that would
4055 otherwise require a lot of explicit cache maintenance. For
4056 some drivers it's also impossible to properly maintain the
4057 cache. For example if the regions that need to be flushed
4058 are not a multiple of the cache-line size, *and* padding
4059 cannot be allocated between the regions to align them (i.e.
4060 if the HW requires a contiguous array of regions, and the
4061 size of each region is not cache-aligned), then a flush of
4062 one region may result in overwriting data that hardware has
4063 written to another region in the same cache-line. This can
4064 happen for example in network drivers where descriptors for
4065 buffers are typically smaller than the CPU cache-line (e.g.
4066 16 bytes vs. 32 or 64 bytes).
4068 Non-cached memory is only supported on 32-bit ARM at present.
4070 - CONFIG_SYS_BOOTM_LEN:
4071 Normally compressed uImages are limited to an
4072 uncompressed size of 8 MBytes. If this is not enough,
4073 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4074 to adjust this setting to your needs.
4076 - CONFIG_SYS_BOOTMAPSZ:
4077 Maximum size of memory mapped by the startup code of
4078 the Linux kernel; all data that must be processed by
4079 the Linux kernel (bd_info, boot arguments, FDT blob if
4080 used) must be put below this limit, unless "bootm_low"
4081 environment variable is defined and non-zero. In such case
4082 all data for the Linux kernel must be between "bootm_low"
4083 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4084 variable "bootm_mapsize" will override the value of
4085 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4086 then the value in "bootm_size" will be used instead.
4088 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4089 Enable initrd_high functionality. If defined then the
4090 initrd_high feature is enabled and the bootm ramdisk subcommand
4093 - CONFIG_SYS_BOOT_GET_CMDLINE:
4094 Enables allocating and saving kernel cmdline in space between
4095 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4097 - CONFIG_SYS_BOOT_GET_KBD:
4098 Enables allocating and saving a kernel copy of the bd_info in
4099 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4101 - CONFIG_SYS_MAX_FLASH_BANKS:
4102 Max number of Flash memory banks
4104 - CONFIG_SYS_MAX_FLASH_SECT:
4105 Max number of sectors on a Flash chip
4107 - CONFIG_SYS_FLASH_ERASE_TOUT:
4108 Timeout for Flash erase operations (in ms)
4110 - CONFIG_SYS_FLASH_WRITE_TOUT:
4111 Timeout for Flash write operations (in ms)
4113 - CONFIG_SYS_FLASH_LOCK_TOUT
4114 Timeout for Flash set sector lock bit operation (in ms)
4116 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4117 Timeout for Flash clear lock bits operation (in ms)
4119 - CONFIG_SYS_FLASH_PROTECTION
4120 If defined, hardware flash sectors protection is used
4121 instead of U-Boot software protection.
4123 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4125 Enable TFTP transfers directly to flash memory;
4126 without this option such a download has to be
4127 performed in two steps: (1) download to RAM, and (2)
4128 copy from RAM to flash.
4130 The two-step approach is usually more reliable, since
4131 you can check if the download worked before you erase
4132 the flash, but in some situations (when system RAM is
4133 too limited to allow for a temporary copy of the
4134 downloaded image) this option may be very useful.
4136 - CONFIG_SYS_FLASH_CFI:
4137 Define if the flash driver uses extra elements in the
4138 common flash structure for storing flash geometry.
4140 - CONFIG_FLASH_CFI_DRIVER
4141 This option also enables the building of the cfi_flash driver
4142 in the drivers directory
4144 - CONFIG_FLASH_CFI_MTD
4145 This option enables the building of the cfi_mtd driver
4146 in the drivers directory. The driver exports CFI flash
4149 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4150 Use buffered writes to flash.
4152 - CONFIG_FLASH_SPANSION_S29WS_N
4153 s29ws-n MirrorBit flash has non-standard addresses for buffered
4156 - CONFIG_SYS_FLASH_QUIET_TEST
4157 If this option is defined, the common CFI flash doesn't
4158 print it's warning upon not recognized FLASH banks. This
4159 is useful, if some of the configured banks are only
4160 optionally available.
4162 - CONFIG_FLASH_SHOW_PROGRESS
4163 If defined (must be an integer), print out countdown
4164 digits and dots. Recommended value: 45 (9..1) for 80
4165 column displays, 15 (3..1) for 40 column displays.
4167 - CONFIG_FLASH_VERIFY
4168 If defined, the content of the flash (destination) is compared
4169 against the source after the write operation. An error message
4170 will be printed when the contents are not identical.
4171 Please note that this option is useless in nearly all cases,
4172 since such flash programming errors usually are detected earlier
4173 while unprotecting/erasing/programming. Please only enable
4174 this option if you really know what you are doing.
4176 - CONFIG_SYS_RX_ETH_BUFFER:
4177 Defines the number of Ethernet receive buffers. On some
4178 Ethernet controllers it is recommended to set this value
4179 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4180 buffers can be full shortly after enabling the interface
4181 on high Ethernet traffic.
4182 Defaults to 4 if not defined.
4184 - CONFIG_ENV_MAX_ENTRIES
4186 Maximum number of entries in the hash table that is used
4187 internally to store the environment settings. The default
4188 setting is supposed to be generous and should work in most
4189 cases. This setting can be used to tune behaviour; see
4190 lib/hashtable.c for details.
4192 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4193 - CONFIG_ENV_FLAGS_LIST_STATIC
4194 Enable validation of the values given to environment variables when
4195 calling env set. Variables can be restricted to only decimal,
4196 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4197 the variables can also be restricted to IP address or MAC address.
4199 The format of the list is:
4200 type_attribute = [s|d|x|b|i|m]
4201 access_attribute = [a|r|o|c]
4202 attributes = type_attribute[access_attribute]
4203 entry = variable_name[:attributes]
4206 The type attributes are:
4207 s - String (default)
4210 b - Boolean ([1yYtT|0nNfF])
4214 The access attributes are:
4220 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4221 Define this to a list (string) to define the ".flags"
4222 environment variable in the default or embedded environment.
4224 - CONFIG_ENV_FLAGS_LIST_STATIC
4225 Define this to a list (string) to define validation that
4226 should be done if an entry is not found in the ".flags"
4227 environment variable. To override a setting in the static
4228 list, simply add an entry for the same variable name to the
4231 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4232 If defined, don't allow the -f switch to env set override variable
4235 - CONFIG_SYS_GENERIC_BOARD
4236 This selects the architecture-generic board system instead of the
4237 architecture-specific board files. It is intended to move boards
4238 to this new framework over time. Defining this will disable the
4239 arch/foo/lib/board.c file and use common/board_f.c and
4240 common/board_r.c instead. To use this option your architecture
4241 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4242 its config.mk file). If you find problems enabling this option on
4243 your board please report the problem and send patches!
4245 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4246 This is set by OMAP boards for the max time that reset should
4247 be asserted. See doc/README.omap-reset-time for details on how
4248 the value can be calculated on a given board.
4251 If stdint.h is available with your toolchain you can define this
4252 option to enable it. You can provide option 'USE_STDINT=1' when
4253 building U-Boot to enable this.
4255 The following definitions that deal with the placement and management
4256 of environment data (variable area); in general, we support the
4257 following configurations:
4259 - CONFIG_BUILD_ENVCRC:
4261 Builds up envcrc with the target environment so that external utils
4262 may easily extract it and embed it in final U-Boot images.
4264 - CONFIG_ENV_IS_IN_FLASH:
4266 Define this if the environment is in flash memory.
4268 a) The environment occupies one whole flash sector, which is
4269 "embedded" in the text segment with the U-Boot code. This
4270 happens usually with "bottom boot sector" or "top boot
4271 sector" type flash chips, which have several smaller
4272 sectors at the start or the end. For instance, such a
4273 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4274 such a case you would place the environment in one of the
4275 4 kB sectors - with U-Boot code before and after it. With
4276 "top boot sector" type flash chips, you would put the
4277 environment in one of the last sectors, leaving a gap
4278 between U-Boot and the environment.
4280 - CONFIG_ENV_OFFSET:
4282 Offset of environment data (variable area) to the
4283 beginning of flash memory; for instance, with bottom boot
4284 type flash chips the second sector can be used: the offset
4285 for this sector is given here.
4287 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4291 This is just another way to specify the start address of
4292 the flash sector containing the environment (instead of
4295 - CONFIG_ENV_SECT_SIZE:
4297 Size of the sector containing the environment.
4300 b) Sometimes flash chips have few, equal sized, BIG sectors.
4301 In such a case you don't want to spend a whole sector for
4306 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4307 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4308 of this flash sector for the environment. This saves
4309 memory for the RAM copy of the environment.
4311 It may also save flash memory if you decide to use this
4312 when your environment is "embedded" within U-Boot code,
4313 since then the remainder of the flash sector could be used
4314 for U-Boot code. It should be pointed out that this is
4315 STRONGLY DISCOURAGED from a robustness point of view:
4316 updating the environment in flash makes it always
4317 necessary to erase the WHOLE sector. If something goes
4318 wrong before the contents has been restored from a copy in
4319 RAM, your target system will be dead.
4321 - CONFIG_ENV_ADDR_REDUND
4322 CONFIG_ENV_SIZE_REDUND
4324 These settings describe a second storage area used to hold
4325 a redundant copy of the environment data, so that there is
4326 a valid backup copy in case there is a power failure during
4327 a "saveenv" operation.
4329 BE CAREFUL! Any changes to the flash layout, and some changes to the
4330 source code will make it necessary to adapt <board>/u-boot.lds*
4334 - CONFIG_ENV_IS_IN_NVRAM:
4336 Define this if you have some non-volatile memory device
4337 (NVRAM, battery buffered SRAM) which you want to use for the
4343 These two #defines are used to determine the memory area you
4344 want to use for environment. It is assumed that this memory
4345 can just be read and written to, without any special
4348 BE CAREFUL! The first access to the environment happens quite early
4349 in U-Boot initialization (when we try to get the setting of for the
4350 console baudrate). You *MUST* have mapped your NVRAM area then, or
4353 Please note that even with NVRAM we still use a copy of the
4354 environment in RAM: we could work on NVRAM directly, but we want to
4355 keep settings there always unmodified except somebody uses "saveenv"
4356 to save the current settings.
4359 - CONFIG_ENV_IS_IN_EEPROM:
4361 Use this if you have an EEPROM or similar serial access
4362 device and a driver for it.
4364 - CONFIG_ENV_OFFSET:
4367 These two #defines specify the offset and size of the
4368 environment area within the total memory of your EEPROM.
4370 - CONFIG_SYS_I2C_EEPROM_ADDR:
4371 If defined, specified the chip address of the EEPROM device.
4372 The default address is zero.
4374 - CONFIG_SYS_I2C_EEPROM_BUS:
4375 If defined, specified the i2c bus of the EEPROM device.
4377 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4378 If defined, the number of bits used to address bytes in a
4379 single page in the EEPROM device. A 64 byte page, for example
4380 would require six bits.
4382 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4383 If defined, the number of milliseconds to delay between
4384 page writes. The default is zero milliseconds.
4386 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4387 The length in bytes of the EEPROM memory array address. Note
4388 that this is NOT the chip address length!
4390 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4391 EEPROM chips that implement "address overflow" are ones
4392 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4393 address and the extra bits end up in the "chip address" bit
4394 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4397 Note that we consider the length of the address field to
4398 still be one byte because the extra address bits are hidden
4399 in the chip address.
4401 - CONFIG_SYS_EEPROM_SIZE:
4402 The size in bytes of the EEPROM device.
4404 - CONFIG_ENV_EEPROM_IS_ON_I2C
4405 define this, if you have I2C and SPI activated, and your
4406 EEPROM, which holds the environment, is on the I2C bus.
4408 - CONFIG_I2C_ENV_EEPROM_BUS
4409 if you have an Environment on an EEPROM reached over
4410 I2C muxes, you can define here, how to reach this
4411 EEPROM. For example:
4413 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4415 EEPROM which holds the environment, is reached over
4416 a pca9547 i2c mux with address 0x70, channel 3.
4418 - CONFIG_ENV_IS_IN_DATAFLASH:
4420 Define this if you have a DataFlash memory device which you
4421 want to use for the environment.
4423 - CONFIG_ENV_OFFSET:
4427 These three #defines specify the offset and size of the
4428 environment area within the total memory of your DataFlash placed
4429 at the specified address.
4431 - CONFIG_ENV_IS_IN_SPI_FLASH:
4433 Define this if you have a SPI Flash memory device which you
4434 want to use for the environment.
4436 - CONFIG_ENV_OFFSET:
4439 These two #defines specify the offset and size of the
4440 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4441 aligned to an erase sector boundary.
4443 - CONFIG_ENV_SECT_SIZE:
4445 Define the SPI flash's sector size.
4447 - CONFIG_ENV_OFFSET_REDUND (optional):
4449 This setting describes a second storage area of CONFIG_ENV_SIZE
4450 size used to hold a redundant copy of the environment data, so
4451 that there is a valid backup copy in case there is a power failure
4452 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4453 aligned to an erase sector boundary.
4455 - CONFIG_ENV_SPI_BUS (optional):
4456 - CONFIG_ENV_SPI_CS (optional):
4458 Define the SPI bus and chip select. If not defined they will be 0.
4460 - CONFIG_ENV_SPI_MAX_HZ (optional):
4462 Define the SPI max work clock. If not defined then use 1MHz.
4464 - CONFIG_ENV_SPI_MODE (optional):
4466 Define the SPI work mode. If not defined then use SPI_MODE_3.
4468 - CONFIG_ENV_IS_IN_REMOTE:
4470 Define this if you have a remote memory space which you
4471 want to use for the local device's environment.
4476 These two #defines specify the address and size of the
4477 environment area within the remote memory space. The
4478 local device can get the environment from remote memory
4479 space by SRIO or PCIE links.
4481 BE CAREFUL! For some special cases, the local device can not use
4482 "saveenv" command. For example, the local device will get the
4483 environment stored in a remote NOR flash by SRIO or PCIE link,
4484 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4486 - CONFIG_ENV_IS_IN_NAND:
4488 Define this if you have a NAND device which you want to use
4489 for the environment.
4491 - CONFIG_ENV_OFFSET:
4494 These two #defines specify the offset and size of the environment
4495 area within the first NAND device. CONFIG_ENV_OFFSET must be
4496 aligned to an erase block boundary.
4498 - CONFIG_ENV_OFFSET_REDUND (optional):
4500 This setting describes a second storage area of CONFIG_ENV_SIZE
4501 size used to hold a redundant copy of the environment data, so
4502 that there is a valid backup copy in case there is a power failure
4503 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4504 aligned to an erase block boundary.
4506 - CONFIG_ENV_RANGE (optional):
4508 Specifies the length of the region in which the environment
4509 can be written. This should be a multiple of the NAND device's
4510 block size. Specifying a range with more erase blocks than
4511 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4512 the range to be avoided.
4514 - CONFIG_ENV_OFFSET_OOB (optional):
4516 Enables support for dynamically retrieving the offset of the
4517 environment from block zero's out-of-band data. The
4518 "nand env.oob" command can be used to record this offset.
4519 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4520 using CONFIG_ENV_OFFSET_OOB.
4522 - CONFIG_NAND_ENV_DST
4524 Defines address in RAM to which the nand_spl code should copy the
4525 environment. If redundant environment is used, it will be copied to
4526 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4528 - CONFIG_ENV_IS_IN_UBI:
4530 Define this if you have an UBI volume that you want to use for the
4531 environment. This has the benefit of wear-leveling the environment
4532 accesses, which is important on NAND.
4534 - CONFIG_ENV_UBI_PART:
4536 Define this to a string that is the mtd partition containing the UBI.
4538 - CONFIG_ENV_UBI_VOLUME:
4540 Define this to the name of the volume that you want to store the
4543 - CONFIG_ENV_UBI_VOLUME_REDUND:
4545 Define this to the name of another volume to store a second copy of
4546 the environment in. This will enable redundant environments in UBI.
4547 It is assumed that both volumes are in the same MTD partition.
4549 - CONFIG_UBI_SILENCE_MSG
4550 - CONFIG_UBIFS_SILENCE_MSG
4552 You will probably want to define these to avoid a really noisy system
4553 when storing the env in UBI.
4555 - CONFIG_ENV_IS_IN_FAT:
4556 Define this if you want to use the FAT file system for the environment.
4558 - FAT_ENV_INTERFACE:
4560 Define this to a string that is the name of the block device.
4562 - FAT_ENV_DEV_AND_PART:
4564 Define this to a string to specify the partition of the device. It can
4567 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4568 - "D:P": device D partition P. Error occurs if device D has no
4571 - "D" or "D:": device D partition 1 if device D has partition
4572 table, or the whole device D if has no partition
4574 - "D:auto": first partition in device D with bootable flag set.
4575 If none, first valid partition in device D. If no
4576 partition table then means device D.
4580 It's a string of the FAT file name. This file use to store the
4584 This should be defined. Otherwise it cannot save the environment file.
4586 - CONFIG_ENV_IS_IN_MMC:
4588 Define this if you have an MMC device which you want to use for the
4591 - CONFIG_SYS_MMC_ENV_DEV:
4593 Specifies which MMC device the environment is stored in.
4595 - CONFIG_SYS_MMC_ENV_PART (optional):
4597 Specifies which MMC partition the environment is stored in. If not
4598 set, defaults to partition 0, the user area. Common values might be
4599 1 (first MMC boot partition), 2 (second MMC boot partition).
4601 - CONFIG_ENV_OFFSET:
4604 These two #defines specify the offset and size of the environment
4605 area within the specified MMC device.
4607 If offset is positive (the usual case), it is treated as relative to
4608 the start of the MMC partition. If offset is negative, it is treated
4609 as relative to the end of the MMC partition. This can be useful if
4610 your board may be fitted with different MMC devices, which have
4611 different sizes for the MMC partitions, and you always want the
4612 environment placed at the very end of the partition, to leave the
4613 maximum possible space before it, to store other data.
4615 These two values are in units of bytes, but must be aligned to an
4616 MMC sector boundary.
4618 - CONFIG_ENV_OFFSET_REDUND (optional):
4620 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4621 hold a redundant copy of the environment data. This provides a
4622 valid backup copy in case the other copy is corrupted, e.g. due
4623 to a power failure during a "saveenv" operation.
4625 This value may also be positive or negative; this is handled in the
4626 same way as CONFIG_ENV_OFFSET.
4628 This value is also in units of bytes, but must also be aligned to
4629 an MMC sector boundary.
4631 - CONFIG_ENV_SIZE_REDUND (optional):
4633 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4634 set. If this value is set, it must be set to the same value as
4637 - CONFIG_SYS_SPI_INIT_OFFSET
4639 Defines offset to the initial SPI buffer area in DPRAM. The
4640 area is used at an early stage (ROM part) if the environment
4641 is configured to reside in the SPI EEPROM: We need a 520 byte
4642 scratch DPRAM area. It is used between the two initialization
4643 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4644 to be a good choice since it makes it far enough from the
4645 start of the data area as well as from the stack pointer.
4647 Please note that the environment is read-only until the monitor
4648 has been relocated to RAM and a RAM copy of the environment has been
4649 created; also, when using EEPROM you will have to use getenv_f()
4650 until then to read environment variables.
4652 The environment is protected by a CRC32 checksum. Before the monitor
4653 is relocated into RAM, as a result of a bad CRC you will be working
4654 with the compiled-in default environment - *silently*!!! [This is
4655 necessary, because the first environment variable we need is the
4656 "baudrate" setting for the console - if we have a bad CRC, we don't
4657 have any device yet where we could complain.]
4659 Note: once the monitor has been relocated, then it will complain if
4660 the default environment is used; a new CRC is computed as soon as you
4661 use the "saveenv" command to store a valid environment.
4663 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4664 Echo the inverted Ethernet link state to the fault LED.
4666 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4667 also needs to be defined.
4669 - CONFIG_SYS_FAULT_MII_ADDR:
4670 MII address of the PHY to check for the Ethernet link state.
4672 - CONFIG_NS16550_MIN_FUNCTIONS:
4673 Define this if you desire to only have use of the NS16550_init
4674 and NS16550_putc functions for the serial driver located at
4675 drivers/serial/ns16550.c. This option is useful for saving
4676 space for already greatly restricted images, including but not
4677 limited to NAND_SPL configurations.
4679 - CONFIG_DISPLAY_BOARDINFO
4680 Display information about the board that U-Boot is running on
4681 when U-Boot starts up. The board function checkboard() is called
4684 - CONFIG_DISPLAY_BOARDINFO_LATE
4685 Similar to the previous option, but display this information
4686 later, once stdio is running and output goes to the LCD, if
4689 - CONFIG_BOARD_SIZE_LIMIT:
4690 Maximum size of the U-Boot image. When defined, the
4691 build system checks that the actual size does not
4694 Low Level (hardware related) configuration options:
4695 ---------------------------------------------------
4697 - CONFIG_SYS_CACHELINE_SIZE:
4698 Cache Line Size of the CPU.
4700 - CONFIG_SYS_DEFAULT_IMMR:
4701 Default address of the IMMR after system reset.
4703 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4704 and RPXsuper) to be able to adjust the position of
4705 the IMMR register after a reset.
4707 - CONFIG_SYS_CCSRBAR_DEFAULT:
4708 Default (power-on reset) physical address of CCSR on Freescale
4711 - CONFIG_SYS_CCSRBAR:
4712 Virtual address of CCSR. On a 32-bit build, this is typically
4713 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4715 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4716 for cross-platform code that uses that macro instead.
4718 - CONFIG_SYS_CCSRBAR_PHYS:
4719 Physical address of CCSR. CCSR can be relocated to a new
4720 physical address, if desired. In this case, this macro should
4721 be set to that address. Otherwise, it should be set to the
4722 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4723 is typically relocated on 36-bit builds. It is recommended
4724 that this macro be defined via the _HIGH and _LOW macros:
4726 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4727 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4729 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4730 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4731 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4732 used in assembly code, so it must not contain typecasts or
4733 integer size suffixes (e.g. "ULL").
4735 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4736 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4737 used in assembly code, so it must not contain typecasts or
4738 integer size suffixes (e.g. "ULL").
4740 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4741 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4742 forced to a value that ensures that CCSR is not relocated.
4744 - Floppy Disk Support:
4745 CONFIG_SYS_FDC_DRIVE_NUMBER
4747 the default drive number (default value 0)
4749 CONFIG_SYS_ISA_IO_STRIDE
4751 defines the spacing between FDC chipset registers
4754 CONFIG_SYS_ISA_IO_OFFSET
4756 defines the offset of register from address. It
4757 depends on which part of the data bus is connected to
4758 the FDC chipset. (default value 0)
4760 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4761 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4764 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4765 fdc_hw_init() is called at the beginning of the FDC
4766 setup. fdc_hw_init() must be provided by the board
4767 source code. It is used to make hardware-dependent
4771 Most IDE controllers were designed to be connected with PCI
4772 interface. Only few of them were designed for AHB interface.
4773 When software is doing ATA command and data transfer to
4774 IDE devices through IDE-AHB controller, some additional
4775 registers accessing to these kind of IDE-AHB controller
4778 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4779 DO NOT CHANGE unless you know exactly what you're
4780 doing! (11-4) [MPC8xx/82xx systems only]
4782 - CONFIG_SYS_INIT_RAM_ADDR:
4784 Start address of memory area that can be used for
4785 initial data and stack; please note that this must be
4786 writable memory that is working WITHOUT special
4787 initialization, i. e. you CANNOT use normal RAM which
4788 will become available only after programming the
4789 memory controller and running certain initialization
4792 U-Boot uses the following memory types:
4793 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4794 - MPC824X: data cache
4795 - PPC4xx: data cache
4797 - CONFIG_SYS_GBL_DATA_OFFSET:
4799 Offset of the initial data structure in the memory
4800 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4801 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4802 data is located at the end of the available space
4803 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4804 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4805 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4806 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4809 On the MPC824X (or other systems that use the data
4810 cache for initial memory) the address chosen for
4811 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4812 point to an otherwise UNUSED address space between
4813 the top of RAM and the start of the PCI space.
4815 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4817 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4819 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4821 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4823 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4825 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4827 - CONFIG_SYS_OR_TIMING_SDRAM:
4830 - CONFIG_SYS_MAMR_PTA:
4831 periodic timer for refresh
4833 - CONFIG_SYS_DER: Debug Event Register (37-47)
4835 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4836 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4837 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4838 CONFIG_SYS_BR1_PRELIM:
4839 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4841 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4842 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4843 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4844 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4846 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4847 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4848 Machine Mode Register and Memory Periodic Timer
4849 Prescaler definitions (SDRAM timing)
4851 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4852 enable I2C microcode relocation patch (MPC8xx);
4853 define relocation offset in DPRAM [DSP2]
4855 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4856 enable SMC microcode relocation patch (MPC8xx);
4857 define relocation offset in DPRAM [SMC1]
4859 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4860 enable SPI microcode relocation patch (MPC8xx);
4861 define relocation offset in DPRAM [SCC4]
4863 - CONFIG_SYS_USE_OSCCLK:
4864 Use OSCM clock mode on MBX8xx board. Be careful,
4865 wrong setting might damage your board. Read
4866 doc/README.MBX before setting this variable!
4868 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4869 Offset of the bootmode word in DPRAM used by post
4870 (Power On Self Tests). This definition overrides
4871 #define'd default value in commproc.h resp.
4874 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4875 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4876 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4877 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4878 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4879 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4880 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4881 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4882 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4884 - CONFIG_PCI_DISABLE_PCIE:
4885 Disable PCI-Express on systems where it is supported but not
4888 - CONFIG_PCI_ENUM_ONLY
4889 Only scan through and get the devices on the buses.
4890 Don't do any setup work, presumably because someone or
4891 something has already done it, and we don't need to do it
4892 a second time. Useful for platforms that are pre-booted
4893 by coreboot or similar.
4895 - CONFIG_PCI_INDIRECT_BRIDGE:
4896 Enable support for indirect PCI bridges.
4899 Chip has SRIO or not
4902 Board has SRIO 1 port available
4905 Board has SRIO 2 port available
4907 - CONFIG_SRIO_PCIE_BOOT_MASTER
4908 Board can support master function for Boot from SRIO and PCIE
4910 - CONFIG_SYS_SRIOn_MEM_VIRT:
4911 Virtual Address of SRIO port 'n' memory region
4913 - CONFIG_SYS_SRIOn_MEM_PHYS:
4914 Physical Address of SRIO port 'n' memory region
4916 - CONFIG_SYS_SRIOn_MEM_SIZE:
4917 Size of SRIO port 'n' memory region
4919 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4920 Defined to tell the NAND controller that the NAND chip is using
4922 Not all NAND drivers use this symbol.
4923 Example of drivers that use it:
4924 - drivers/mtd/nand/ndfc.c
4925 - drivers/mtd/nand/mxc_nand.c
4927 - CONFIG_SYS_NDFC_EBC0_CFG
4928 Sets the EBC0_CFG register for the NDFC. If not defined
4929 a default value will be used.
4932 Get DDR timing information from an I2C EEPROM. Common
4933 with pluggable memory modules such as SODIMMs
4936 I2C address of the SPD EEPROM
4938 - CONFIG_SYS_SPD_BUS_NUM
4939 If SPD EEPROM is on an I2C bus other than the first
4940 one, specify here. Note that the value must resolve
4941 to something your driver can deal with.
4943 - CONFIG_SYS_DDR_RAW_TIMING
4944 Get DDR timing information from other than SPD. Common with
4945 soldered DDR chips onboard without SPD. DDR raw timing
4946 parameters are extracted from datasheet and hard-coded into
4947 header files or board specific files.
4949 - CONFIG_FSL_DDR_INTERACTIVE
4950 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4952 - CONFIG_FSL_DDR_SYNC_REFRESH
4953 Enable sync of refresh for multiple controllers.
4955 - CONFIG_SYS_83XX_DDR_USES_CS0
4956 Only for 83xx systems. If specified, then DDR should
4957 be configured using CS0 and CS1 instead of CS2 and CS3.
4959 - CONFIG_ETHER_ON_FEC[12]
4960 Define to enable FEC[12] on a 8xx series processor.
4962 - CONFIG_FEC[12]_PHY
4963 Define to the hardcoded PHY address which corresponds
4964 to the given FEC; i. e.
4965 #define CONFIG_FEC1_PHY 4
4966 means that the PHY with address 4 is connected to FEC1
4968 When set to -1, means to probe for first available.
4970 - CONFIG_FEC[12]_PHY_NORXERR
4971 The PHY does not have a RXERR line (RMII only).
4972 (so program the FEC to ignore it).
4975 Enable RMII mode for all FECs.
4976 Note that this is a global option, we can't
4977 have one FEC in standard MII mode and another in RMII mode.
4979 - CONFIG_CRC32_VERIFY
4980 Add a verify option to the crc32 command.
4983 => crc32 -v <address> <count> <crc32>
4985 Where address/count indicate a memory area
4986 and crc32 is the correct crc32 which the
4990 Add the "loopw" memory command. This only takes effect if
4991 the memory commands are activated globally (CONFIG_CMD_MEM).
4994 Add the "mdc" and "mwc" memory commands. These are cyclic
4999 This command will print 4 bytes (10,11,12,13) each 500 ms.
5001 => mwc.l 100 12345678 10
5002 This command will write 12345678 to address 100 all 10 ms.
5004 This only takes effect if the memory commands are activated
5005 globally (CONFIG_CMD_MEM).
5007 - CONFIG_SKIP_LOWLEVEL_INIT
5008 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5009 low level initializations (like setting up the memory
5010 controller) are omitted and/or U-Boot does not
5011 relocate itself into RAM.
5013 Normally this variable MUST NOT be defined. The only
5014 exception is when U-Boot is loaded (to RAM) by some
5015 other boot loader or by a debugger which performs
5016 these initializations itself.
5019 Modifies the behaviour of start.S when compiling a loader
5020 that is executed before the actual U-Boot. E.g. when
5021 compiling a NAND SPL.
5024 Modifies the behaviour of start.S when compiling a loader
5025 that is executed after the SPL and before the actual U-Boot.
5026 It is loaded by the SPL.
5028 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5029 Only for 85xx systems. If this variable is specified, the section
5030 .resetvec is not kept and the section .bootpg is placed in the
5031 previous 4k of the .text section.
5033 - CONFIG_ARCH_MAP_SYSMEM
5034 Generally U-Boot (and in particular the md command) uses
5035 effective address. It is therefore not necessary to regard
5036 U-Boot address as virtual addresses that need to be translated
5037 to physical addresses. However, sandbox requires this, since
5038 it maintains its own little RAM buffer which contains all
5039 addressable memory. This option causes some memory accesses
5040 to be mapped through map_sysmem() / unmap_sysmem().
5042 - CONFIG_USE_ARCH_MEMCPY
5043 CONFIG_USE_ARCH_MEMSET
5044 If these options are used a optimized version of memcpy/memset will
5045 be used if available. These functions may be faster under some
5046 conditions but may increase the binary size.
5048 - CONFIG_X86_RESET_VECTOR
5049 If defined, the x86 reset vector code is included. This is not
5050 needed when U-Boot is running from Coreboot.
5053 Defines the MPU clock speed (in MHz).
5055 NOTE : currently only supported on AM335x platforms.
5057 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5058 Enables the RTC32K OSC on AM33xx based plattforms
5060 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5061 Option to disable subpage write in NAND driver
5062 driver that uses this:
5063 drivers/mtd/nand/davinci_nand.c
5065 Freescale QE/FMAN Firmware Support:
5066 -----------------------------------
5068 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5069 loading of "firmware", which is encoded in the QE firmware binary format.
5070 This firmware often needs to be loaded during U-Boot booting, so macros
5071 are used to identify the storage device (NOR flash, SPI, etc) and the address
5074 - CONFIG_SYS_FMAN_FW_ADDR
5075 The address in the storage device where the FMAN microcode is located. The
5076 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5079 - CONFIG_SYS_QE_FW_ADDR
5080 The address in the storage device where the QE microcode is located. The
5081 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5084 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5085 The maximum possible size of the firmware. The firmware binary format
5086 has a field that specifies the actual size of the firmware, but it
5087 might not be possible to read any part of the firmware unless some
5088 local storage is allocated to hold the entire firmware first.
5090 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5091 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5092 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5093 virtual address in NOR flash.
5095 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5096 Specifies that QE/FMAN firmware is located in NAND flash.
5097 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5099 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5100 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5101 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5103 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5104 Specifies that QE/FMAN firmware is located on the primary SPI
5105 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5107 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5108 Specifies that QE/FMAN firmware is located in the remote (master)
5109 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5110 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5111 window->master inbound window->master LAW->the ucode address in
5112 master's memory space.
5114 Freescale Layerscape Management Complex Firmware Support:
5115 ---------------------------------------------------------
5116 The Freescale Layerscape Management Complex (MC) supports the loading of
5118 This firmware often needs to be loaded during U-Boot booting, so macros
5119 are used to identify the storage device (NOR flash, SPI, etc) and the address
5122 - CONFIG_FSL_MC_ENET
5123 Enable the MC driver for Layerscape SoCs.
5125 - CONFIG_SYS_LS_MC_FW_ADDR
5126 The address in the storage device where the firmware is located. The
5127 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5130 - CONFIG_SYS_LS_MC_FW_LENGTH
5131 The maximum possible size of the firmware. The firmware binary format
5132 has a field that specifies the actual size of the firmware, but it
5133 might not be possible to read any part of the firmware unless some
5134 local storage is allocated to hold the entire firmware first.
5136 - CONFIG_SYS_LS_MC_FW_IN_NOR
5137 Specifies that MC firmware is located in NOR flash, mapped as
5138 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5139 virtual address in NOR flash.
5141 Building the Software:
5142 ======================
5144 Building U-Boot has been tested in several native build environments
5145 and in many different cross environments. Of course we cannot support
5146 all possibly existing versions of cross development tools in all
5147 (potentially obsolete) versions. In case of tool chain problems we
5148 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5149 which is extensively used to build and test U-Boot.
5151 If you are not using a native environment, it is assumed that you
5152 have GNU cross compiling tools available in your path. In this case,
5153 you must set the environment variable CROSS_COMPILE in your shell.
5154 Note that no changes to the Makefile or any other source files are
5155 necessary. For example using the ELDK on a 4xx CPU, please enter:
5157 $ CROSS_COMPILE=ppc_4xx-
5158 $ export CROSS_COMPILE
5160 Note: If you wish to generate Windows versions of the utilities in
5161 the tools directory you can use the MinGW toolchain
5162 (http://www.mingw.org). Set your HOST tools to the MinGW
5163 toolchain and execute 'make tools'. For example:
5165 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5167 Binaries such as tools/mkimage.exe will be created which can
5168 be executed on computers running Windows.
5170 U-Boot is intended to be simple to build. After installing the
5171 sources you must configure U-Boot for one specific board type. This
5176 where "NAME_defconfig" is the name of one of the existing configu-
5177 rations; see boards.cfg for supported names.
5179 Note: for some board special configuration names may exist; check if
5180 additional information is available from the board vendor; for
5181 instance, the TQM823L systems are available without (standard)
5182 or with LCD support. You can select such additional "features"
5183 when choosing the configuration, i. e.
5185 make TQM823L_defconfig
5186 - will configure for a plain TQM823L, i. e. no LCD support
5188 make TQM823L_LCD_defconfig
5189 - will configure for a TQM823L with U-Boot console on LCD
5194 Finally, type "make all", and you should get some working U-Boot
5195 images ready for download to / installation on your system:
5197 - "u-boot.bin" is a raw binary image
5198 - "u-boot" is an image in ELF binary format
5199 - "u-boot.srec" is in Motorola S-Record format
5201 By default the build is performed locally and the objects are saved
5202 in the source directory. One of the two methods can be used to change
5203 this behavior and build U-Boot to some external directory:
5205 1. Add O= to the make command line invocations:
5207 make O=/tmp/build distclean
5208 make O=/tmp/build NAME_defconfig
5209 make O=/tmp/build all
5211 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5213 export KBUILD_OUTPUT=/tmp/build
5218 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5222 Please be aware that the Makefiles assume you are using GNU make, so
5223 for instance on NetBSD you might need to use "gmake" instead of
5227 If the system board that you have is not listed, then you will need
5228 to port U-Boot to your hardware platform. To do this, follow these
5231 1. Add a new configuration option for your board to the toplevel
5232 "boards.cfg" file, using the existing entries as examples.
5233 Follow the instructions there to keep the boards in order.
5234 2. Create a new directory to hold your board specific code. Add any
5235 files you need. In your board directory, you will need at least
5236 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5237 3. Create a new configuration file "include/configs/<board>.h" for
5239 3. If you're porting U-Boot to a new CPU, then also create a new
5240 directory to hold your CPU specific code. Add any files you need.
5241 4. Run "make <board>_defconfig" with your new name.
5242 5. Type "make", and you should get a working "u-boot.srec" file
5243 to be installed on your target system.
5244 6. Debug and solve any problems that might arise.
5245 [Of course, this last step is much harder than it sounds.]
5248 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5249 ==============================================================
5251 If you have modified U-Boot sources (for instance added a new board
5252 or support for new devices, a new CPU, etc.) you are expected to
5253 provide feedback to the other developers. The feedback normally takes
5254 the form of a "patch", i. e. a context diff against a certain (latest
5255 official or latest in the git repository) version of U-Boot sources.
5257 But before you submit such a patch, please verify that your modifi-
5258 cation did not break existing code. At least make sure that *ALL* of
5259 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5260 just run the "MAKEALL" script, which will configure and build U-Boot
5261 for ALL supported system. Be warned, this will take a while. You can
5262 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5263 environment variable to the script, i. e. to use the ELDK cross tools
5266 CROSS_COMPILE=ppc_8xx- MAKEALL
5268 or to build on a native PowerPC system you can type
5270 CROSS_COMPILE=' ' MAKEALL
5272 When using the MAKEALL script, the default behaviour is to build
5273 U-Boot in the source directory. This location can be changed by
5274 setting the BUILD_DIR environment variable. Also, for each target
5275 built, the MAKEALL script saves two log files (<target>.ERR and
5276 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5277 location can be changed by setting the MAKEALL_LOGDIR environment
5278 variable. For example:
5280 export BUILD_DIR=/tmp/build
5281 export MAKEALL_LOGDIR=/tmp/log
5282 CROSS_COMPILE=ppc_8xx- MAKEALL
5284 With the above settings build objects are saved in the /tmp/build,
5285 log files are saved in the /tmp/log and the source tree remains clean
5286 during the whole build process.
5289 See also "U-Boot Porting Guide" below.
5292 Monitor Commands - Overview:
5293 ============================
5295 go - start application at address 'addr'
5296 run - run commands in an environment variable
5297 bootm - boot application image from memory
5298 bootp - boot image via network using BootP/TFTP protocol
5299 bootz - boot zImage from memory
5300 tftpboot- boot image via network using TFTP protocol
5301 and env variables "ipaddr" and "serverip"
5302 (and eventually "gatewayip")
5303 tftpput - upload a file via network using TFTP protocol
5304 rarpboot- boot image via network using RARP/TFTP protocol
5305 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5306 loads - load S-Record file over serial line
5307 loadb - load binary file over serial line (kermit mode)
5309 mm - memory modify (auto-incrementing)
5310 nm - memory modify (constant address)
5311 mw - memory write (fill)
5313 cmp - memory compare
5314 crc32 - checksum calculation
5315 i2c - I2C sub-system
5316 sspi - SPI utility commands
5317 base - print or set address offset
5318 printenv- print environment variables
5319 setenv - set environment variables
5320 saveenv - save environment variables to persistent storage
5321 protect - enable or disable FLASH write protection
5322 erase - erase FLASH memory
5323 flinfo - print FLASH memory information
5324 nand - NAND memory operations (see doc/README.nand)
5325 bdinfo - print Board Info structure
5326 iminfo - print header information for application image
5327 coninfo - print console devices and informations
5328 ide - IDE sub-system
5329 loop - infinite loop on address range
5330 loopw - infinite write loop on address range
5331 mtest - simple RAM test
5332 icache - enable or disable instruction cache
5333 dcache - enable or disable data cache
5334 reset - Perform RESET of the CPU
5335 echo - echo args to console
5336 version - print monitor version
5337 help - print online help
5338 ? - alias for 'help'
5341 Monitor Commands - Detailed Description:
5342 ========================================
5346 For now: just type "help <command>".
5349 Environment Variables:
5350 ======================
5352 U-Boot supports user configuration using Environment Variables which
5353 can be made persistent by saving to Flash memory.
5355 Environment Variables are set using "setenv", printed using
5356 "printenv", and saved to Flash using "saveenv". Using "setenv"
5357 without a value can be used to delete a variable from the
5358 environment. As long as you don't save the environment you are
5359 working with an in-memory copy. In case the Flash area containing the
5360 environment is erased by accident, a default environment is provided.
5362 Some configuration options can be set using Environment Variables.
5364 List of environment variables (most likely not complete):
5366 baudrate - see CONFIG_BAUDRATE
5368 bootdelay - see CONFIG_BOOTDELAY
5370 bootcmd - see CONFIG_BOOTCOMMAND
5372 bootargs - Boot arguments when booting an RTOS image
5374 bootfile - Name of the image to load with TFTP
5376 bootm_low - Memory range available for image processing in the bootm
5377 command can be restricted. This variable is given as
5378 a hexadecimal number and defines lowest address allowed
5379 for use by the bootm command. See also "bootm_size"
5380 environment variable. Address defined by "bootm_low" is
5381 also the base of the initial memory mapping for the Linux
5382 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5385 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5386 This variable is given as a hexadecimal number and it
5387 defines the size of the memory region starting at base
5388 address bootm_low that is accessible by the Linux kernel
5389 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5390 as the default value if it is defined, and bootm_size is
5393 bootm_size - Memory range available for image processing in the bootm
5394 command can be restricted. This variable is given as
5395 a hexadecimal number and defines the size of the region
5396 allowed for use by the bootm command. See also "bootm_low"
5397 environment variable.
5399 updatefile - Location of the software update file on a TFTP server, used
5400 by the automatic software update feature. Please refer to
5401 documentation in doc/README.update for more details.
5403 autoload - if set to "no" (any string beginning with 'n'),
5404 "bootp" will just load perform a lookup of the
5405 configuration from the BOOTP server, but not try to
5406 load any image using TFTP
5408 autostart - if set to "yes", an image loaded using the "bootp",
5409 "rarpboot", "tftpboot" or "diskboot" commands will
5410 be automatically started (by internally calling
5413 If set to "no", a standalone image passed to the
5414 "bootm" command will be copied to the load address
5415 (and eventually uncompressed), but NOT be started.
5416 This can be used to load and uncompress arbitrary
5419 fdt_high - if set this restricts the maximum address that the
5420 flattened device tree will be copied into upon boot.
5421 For example, if you have a system with 1 GB memory
5422 at physical address 0x10000000, while Linux kernel
5423 only recognizes the first 704 MB as low memory, you
5424 may need to set fdt_high as 0x3C000000 to have the
5425 device tree blob be copied to the maximum address
5426 of the 704 MB low memory, so that Linux kernel can
5427 access it during the boot procedure.
5429 If this is set to the special value 0xFFFFFFFF then
5430 the fdt will not be copied at all on boot. For this
5431 to work it must reside in writable memory, have
5432 sufficient padding on the end of it for u-boot to
5433 add the information it needs into it, and the memory
5434 must be accessible by the kernel.
5436 fdtcontroladdr- if set this is the address of the control flattened
5437 device tree used by U-Boot when CONFIG_OF_CONTROL is
5440 i2cfast - (PPC405GP|PPC405EP only)
5441 if set to 'y' configures Linux I2C driver for fast
5442 mode (400kHZ). This environment variable is used in
5443 initialization code. So, for changes to be effective
5444 it must be saved and board must be reset.
5446 initrd_high - restrict positioning of initrd images:
5447 If this variable is not set, initrd images will be
5448 copied to the highest possible address in RAM; this
5449 is usually what you want since it allows for
5450 maximum initrd size. If for some reason you want to
5451 make sure that the initrd image is loaded below the
5452 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5453 variable to a value of "no" or "off" or "0".
5454 Alternatively, you can set it to a maximum upper
5455 address to use (U-Boot will still check that it
5456 does not overwrite the U-Boot stack and data).
5458 For instance, when you have a system with 16 MB
5459 RAM, and want to reserve 4 MB from use by Linux,
5460 you can do this by adding "mem=12M" to the value of
5461 the "bootargs" variable. However, now you must make
5462 sure that the initrd image is placed in the first
5463 12 MB as well - this can be done with
5465 setenv initrd_high 00c00000
5467 If you set initrd_high to 0xFFFFFFFF, this is an
5468 indication to U-Boot that all addresses are legal
5469 for the Linux kernel, including addresses in flash
5470 memory. In this case U-Boot will NOT COPY the
5471 ramdisk at all. This may be useful to reduce the
5472 boot time on your system, but requires that this
5473 feature is supported by your Linux kernel.
5475 ipaddr - IP address; needed for tftpboot command
5477 loadaddr - Default load address for commands like "bootp",
5478 "rarpboot", "tftpboot", "loadb" or "diskboot"
5480 loads_echo - see CONFIG_LOADS_ECHO
5482 serverip - TFTP server IP address; needed for tftpboot command
5484 bootretry - see CONFIG_BOOT_RETRY_TIME
5486 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5488 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5490 ethprime - controls which interface is used first.
5492 ethact - controls which interface is currently active.
5493 For example you can do the following
5495 => setenv ethact FEC
5496 => ping 192.168.0.1 # traffic sent on FEC
5497 => setenv ethact SCC
5498 => ping 10.0.0.1 # traffic sent on SCC
5500 ethrotate - When set to "no" U-Boot does not go through all
5501 available network interfaces.
5502 It just stays at the currently selected interface.
5504 netretry - When set to "no" each network operation will
5505 either succeed or fail without retrying.
5506 When set to "once" the network operation will
5507 fail when all the available network interfaces
5508 are tried once without success.
5509 Useful on scripts which control the retry operation
5512 npe_ucode - set load address for the NPE microcode
5514 silent_linux - If set then Linux will be told to boot silently, by
5515 changing the console to be empty. If "yes" it will be
5516 made silent. If "no" it will not be made silent. If
5517 unset, then it will be made silent if the U-Boot console
5520 tftpsrcport - If this is set, the value is used for TFTP's
5523 tftpdstport - If this is set, the value is used for TFTP's UDP
5524 destination port instead of the Well Know Port 69.
5526 tftpblocksize - Block size to use for TFTP transfers; if not set,
5527 we use the TFTP server's default block size
5529 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5530 seconds, minimum value is 1000 = 1 second). Defines
5531 when a packet is considered to be lost so it has to
5532 be retransmitted. The default is 5000 = 5 seconds.
5533 Lowering this value may make downloads succeed
5534 faster in networks with high packet loss rates or
5535 with unreliable TFTP servers.
5537 vlan - When set to a value < 4095 the traffic over
5538 Ethernet is encapsulated/received over 802.1q
5541 The following image location variables contain the location of images
5542 used in booting. The "Image" column gives the role of the image and is
5543 not an environment variable name. The other columns are environment
5544 variable names. "File Name" gives the name of the file on a TFTP
5545 server, "RAM Address" gives the location in RAM the image will be
5546 loaded to, and "Flash Location" gives the image's address in NOR
5547 flash or offset in NAND flash.
5549 *Note* - these variables don't have to be defined for all boards, some
5550 boards currenlty use other variables for these purposes, and some
5551 boards use these variables for other purposes.
5553 Image File Name RAM Address Flash Location
5554 ----- --------- ----------- --------------
5555 u-boot u-boot u-boot_addr_r u-boot_addr
5556 Linux kernel bootfile kernel_addr_r kernel_addr
5557 device tree blob fdtfile fdt_addr_r fdt_addr
5558 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5560 The following environment variables may be used and automatically
5561 updated by the network boot commands ("bootp" and "rarpboot"),
5562 depending the information provided by your boot server:
5564 bootfile - see above
5565 dnsip - IP address of your Domain Name Server
5566 dnsip2 - IP address of your secondary Domain Name Server
5567 gatewayip - IP address of the Gateway (Router) to use
5568 hostname - Target hostname
5570 netmask - Subnet Mask
5571 rootpath - Pathname of the root filesystem on the NFS server
5572 serverip - see above
5575 There are two special Environment Variables:
5577 serial# - contains hardware identification information such
5578 as type string and/or serial number
5579 ethaddr - Ethernet address
5581 These variables can be set only once (usually during manufacturing of
5582 the board). U-Boot refuses to delete or overwrite these variables
5583 once they have been set once.
5586 Further special Environment Variables:
5588 ver - Contains the U-Boot version string as printed
5589 with the "version" command. This variable is
5590 readonly (see CONFIG_VERSION_VARIABLE).
5593 Please note that changes to some configuration parameters may take
5594 only effect after the next boot (yes, that's just like Windoze :-).
5597 Callback functions for environment variables:
5598 ---------------------------------------------
5600 For some environment variables, the behavior of u-boot needs to change
5601 when their values are changed. This functionality allows functions to
5602 be associated with arbitrary variables. On creation, overwrite, or
5603 deletion, the callback will provide the opportunity for some side
5604 effect to happen or for the change to be rejected.
5606 The callbacks are named and associated with a function using the
5607 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5609 These callbacks are associated with variables in one of two ways. The
5610 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5611 in the board configuration to a string that defines a list of
5612 associations. The list must be in the following format:
5614 entry = variable_name[:callback_name]
5617 If the callback name is not specified, then the callback is deleted.
5618 Spaces are also allowed anywhere in the list.
5620 Callbacks can also be associated by defining the ".callbacks" variable
5621 with the same list format above. Any association in ".callbacks" will
5622 override any association in the static list. You can define
5623 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5624 ".callbacks" environment variable in the default or embedded environment.
5627 Command Line Parsing:
5628 =====================
5630 There are two different command line parsers available with U-Boot:
5631 the old "simple" one, and the much more powerful "hush" shell:
5633 Old, simple command line parser:
5634 --------------------------------
5636 - supports environment variables (through setenv / saveenv commands)
5637 - several commands on one line, separated by ';'
5638 - variable substitution using "... ${name} ..." syntax
5639 - special characters ('$', ';') can be escaped by prefixing with '\',
5641 setenv bootcmd bootm \${address}
5642 - You can also escape text by enclosing in single apostrophes, for example:
5643 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5648 - similar to Bourne shell, with control structures like
5649 if...then...else...fi, for...do...done; while...do...done,
5650 until...do...done, ...
5651 - supports environment ("global") variables (through setenv / saveenv
5652 commands) and local shell variables (through standard shell syntax
5653 "name=value"); only environment variables can be used with "run"
5659 (1) If a command line (or an environment variable executed by a "run"
5660 command) contains several commands separated by semicolon, and
5661 one of these commands fails, then the remaining commands will be
5664 (2) If you execute several variables with one call to run (i. e.
5665 calling run with a list of variables as arguments), any failing
5666 command will cause "run" to terminate, i. e. the remaining
5667 variables are not executed.
5669 Note for Redundant Ethernet Interfaces:
5670 =======================================
5672 Some boards come with redundant Ethernet interfaces; U-Boot supports
5673 such configurations and is capable of automatic selection of a
5674 "working" interface when needed. MAC assignment works as follows:
5676 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5677 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5678 "eth1addr" (=>eth1), "eth2addr", ...
5680 If the network interface stores some valid MAC address (for instance
5681 in SROM), this is used as default address if there is NO correspon-
5682 ding setting in the environment; if the corresponding environment
5683 variable is set, this overrides the settings in the card; that means:
5685 o If the SROM has a valid MAC address, and there is no address in the
5686 environment, the SROM's address is used.
5688 o If there is no valid address in the SROM, and a definition in the
5689 environment exists, then the value from the environment variable is
5692 o If both the SROM and the environment contain a MAC address, and
5693 both addresses are the same, this MAC address is used.
5695 o If both the SROM and the environment contain a MAC address, and the
5696 addresses differ, the value from the environment is used and a
5699 o If neither SROM nor the environment contain a MAC address, an error
5702 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5703 will be programmed into hardware as part of the initialization process. This
5704 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5705 The naming convention is as follows:
5706 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5711 U-Boot is capable of booting (and performing other auxiliary operations on)
5712 images in two formats:
5714 New uImage format (FIT)
5715 -----------------------
5717 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5718 to Flattened Device Tree). It allows the use of images with multiple
5719 components (several kernels, ramdisks, etc.), with contents protected by
5720 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5726 Old image format is based on binary files which can be basically anything,
5727 preceded by a special header; see the definitions in include/image.h for
5728 details; basically, the header defines the following image properties:
5730 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5731 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5732 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5733 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5735 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5736 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5737 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5738 * Compression Type (uncompressed, gzip, bzip2)
5744 The header is marked by a special Magic Number, and both the header
5745 and the data portions of the image are secured against corruption by
5752 Although U-Boot should support any OS or standalone application
5753 easily, the main focus has always been on Linux during the design of
5756 U-Boot includes many features that so far have been part of some
5757 special "boot loader" code within the Linux kernel. Also, any
5758 "initrd" images to be used are no longer part of one big Linux image;
5759 instead, kernel and "initrd" are separate images. This implementation
5760 serves several purposes:
5762 - the same features can be used for other OS or standalone
5763 applications (for instance: using compressed images to reduce the
5764 Flash memory footprint)
5766 - it becomes much easier to port new Linux kernel versions because
5767 lots of low-level, hardware dependent stuff are done by U-Boot
5769 - the same Linux kernel image can now be used with different "initrd"
5770 images; of course this also means that different kernel images can
5771 be run with the same "initrd". This makes testing easier (you don't
5772 have to build a new "zImage.initrd" Linux image when you just
5773 change a file in your "initrd"). Also, a field-upgrade of the
5774 software is easier now.
5780 Porting Linux to U-Boot based systems:
5781 ---------------------------------------
5783 U-Boot cannot save you from doing all the necessary modifications to
5784 configure the Linux device drivers for use with your target hardware
5785 (no, we don't intend to provide a full virtual machine interface to
5788 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5790 Just make sure your machine specific header file (for instance
5791 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5792 Information structure as we define in include/asm-<arch>/u-boot.h,
5793 and make sure that your definition of IMAP_ADDR uses the same value
5794 as your U-Boot configuration in CONFIG_SYS_IMMR.
5796 Note that U-Boot now has a driver model, a unified model for drivers.
5797 If you are adding a new driver, plumb it into driver model. If there
5798 is no uclass available, you are encouraged to create one. See
5802 Configuring the Linux kernel:
5803 -----------------------------
5805 No specific requirements for U-Boot. Make sure you have some root
5806 device (initial ramdisk, NFS) for your target system.
5809 Building a Linux Image:
5810 -----------------------
5812 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5813 not used. If you use recent kernel source, a new build target
5814 "uImage" will exist which automatically builds an image usable by
5815 U-Boot. Most older kernels also have support for a "pImage" target,
5816 which was introduced for our predecessor project PPCBoot and uses a
5817 100% compatible format.
5821 make TQM850L_defconfig
5826 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5827 encapsulate a compressed Linux kernel image with header information,
5828 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5830 * build a standard "vmlinux" kernel image (in ELF binary format):
5832 * convert the kernel into a raw binary image:
5834 ${CROSS_COMPILE}-objcopy -O binary \
5835 -R .note -R .comment \
5836 -S vmlinux linux.bin
5838 * compress the binary image:
5842 * package compressed binary image for U-Boot:
5844 mkimage -A ppc -O linux -T kernel -C gzip \
5845 -a 0 -e 0 -n "Linux Kernel Image" \
5846 -d linux.bin.gz uImage
5849 The "mkimage" tool can also be used to create ramdisk images for use
5850 with U-Boot, either separated from the Linux kernel image, or
5851 combined into one file. "mkimage" encapsulates the images with a 64
5852 byte header containing information about target architecture,
5853 operating system, image type, compression method, entry points, time
5854 stamp, CRC32 checksums, etc.
5856 "mkimage" can be called in two ways: to verify existing images and
5857 print the header information, or to build new images.
5859 In the first form (with "-l" option) mkimage lists the information
5860 contained in the header of an existing U-Boot image; this includes
5861 checksum verification:
5863 tools/mkimage -l image
5864 -l ==> list image header information
5866 The second form (with "-d" option) is used to build a U-Boot image
5867 from a "data file" which is used as image payload:
5869 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5870 -n name -d data_file image
5871 -A ==> set architecture to 'arch'
5872 -O ==> set operating system to 'os'
5873 -T ==> set image type to 'type'
5874 -C ==> set compression type 'comp'
5875 -a ==> set load address to 'addr' (hex)
5876 -e ==> set entry point to 'ep' (hex)
5877 -n ==> set image name to 'name'
5878 -d ==> use image data from 'datafile'
5880 Right now, all Linux kernels for PowerPC systems use the same load
5881 address (0x00000000), but the entry point address depends on the
5884 - 2.2.x kernels have the entry point at 0x0000000C,
5885 - 2.3.x and later kernels have the entry point at 0x00000000.
5887 So a typical call to build a U-Boot image would read:
5889 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5890 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5891 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5892 > examples/uImage.TQM850L
5893 Image Name: 2.4.4 kernel for TQM850L
5894 Created: Wed Jul 19 02:34:59 2000
5895 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5896 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5897 Load Address: 0x00000000
5898 Entry Point: 0x00000000
5900 To verify the contents of the image (or check for corruption):
5902 -> tools/mkimage -l examples/uImage.TQM850L
5903 Image Name: 2.4.4 kernel for TQM850L
5904 Created: Wed Jul 19 02:34:59 2000
5905 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5906 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5907 Load Address: 0x00000000
5908 Entry Point: 0x00000000
5910 NOTE: for embedded systems where boot time is critical you can trade
5911 speed for memory and install an UNCOMPRESSED image instead: this
5912 needs more space in Flash, but boots much faster since it does not
5913 need to be uncompressed:
5915 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5916 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5917 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5918 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5919 > examples/uImage.TQM850L-uncompressed
5920 Image Name: 2.4.4 kernel for TQM850L
5921 Created: Wed Jul 19 02:34:59 2000
5922 Image Type: PowerPC Linux Kernel Image (uncompressed)
5923 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5924 Load Address: 0x00000000
5925 Entry Point: 0x00000000
5928 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5929 when your kernel is intended to use an initial ramdisk:
5931 -> tools/mkimage -n 'Simple Ramdisk Image' \
5932 > -A ppc -O linux -T ramdisk -C gzip \
5933 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5934 Image Name: Simple Ramdisk Image
5935 Created: Wed Jan 12 14:01:50 2000
5936 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5937 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5938 Load Address: 0x00000000
5939 Entry Point: 0x00000000
5941 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5942 option performs the converse operation of the mkimage's second form (the "-d"
5943 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5946 tools/dumpimage -i image -T type -p position data_file
5947 -i ==> extract from the 'image' a specific 'data_file'
5948 -T ==> set image type to 'type'
5949 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5952 Installing a Linux Image:
5953 -------------------------
5955 To downloading a U-Boot image over the serial (console) interface,
5956 you must convert the image to S-Record format:
5958 objcopy -I binary -O srec examples/image examples/image.srec
5960 The 'objcopy' does not understand the information in the U-Boot
5961 image header, so the resulting S-Record file will be relative to
5962 address 0x00000000. To load it to a given address, you need to
5963 specify the target address as 'offset' parameter with the 'loads'
5966 Example: install the image to address 0x40100000 (which on the
5967 TQM8xxL is in the first Flash bank):
5969 => erase 40100000 401FFFFF
5975 ## Ready for S-Record download ...
5976 ~>examples/image.srec
5977 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5979 15989 15990 15991 15992
5980 [file transfer complete]
5982 ## Start Addr = 0x00000000
5985 You can check the success of the download using the 'iminfo' command;
5986 this includes a checksum verification so you can be sure no data
5987 corruption happened:
5991 ## Checking Image at 40100000 ...
5992 Image Name: 2.2.13 for initrd on TQM850L
5993 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5994 Data Size: 335725 Bytes = 327 kB = 0 MB
5995 Load Address: 00000000
5996 Entry Point: 0000000c
5997 Verifying Checksum ... OK
6003 The "bootm" command is used to boot an application that is stored in
6004 memory (RAM or Flash). In case of a Linux kernel image, the contents
6005 of the "bootargs" environment variable is passed to the kernel as
6006 parameters. You can check and modify this variable using the
6007 "printenv" and "setenv" commands:
6010 => printenv bootargs
6011 bootargs=root=/dev/ram
6013 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6015 => printenv bootargs
6016 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6019 ## Booting Linux kernel at 40020000 ...
6020 Image Name: 2.2.13 for NFS on TQM850L
6021 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6022 Data Size: 381681 Bytes = 372 kB = 0 MB
6023 Load Address: 00000000
6024 Entry Point: 0000000c
6025 Verifying Checksum ... OK
6026 Uncompressing Kernel Image ... OK
6027 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
6028 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6029 time_init: decrementer frequency = 187500000/60
6030 Calibrating delay loop... 49.77 BogoMIPS
6031 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6034 If you want to boot a Linux kernel with initial RAM disk, you pass
6035 the memory addresses of both the kernel and the initrd image (PPBCOOT
6036 format!) to the "bootm" command:
6038 => imi 40100000 40200000
6040 ## Checking Image at 40100000 ...
6041 Image Name: 2.2.13 for initrd on TQM850L
6042 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6043 Data Size: 335725 Bytes = 327 kB = 0 MB
6044 Load Address: 00000000
6045 Entry Point: 0000000c
6046 Verifying Checksum ... OK
6048 ## Checking Image at 40200000 ...
6049 Image Name: Simple Ramdisk Image
6050 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6051 Data Size: 566530 Bytes = 553 kB = 0 MB
6052 Load Address: 00000000
6053 Entry Point: 00000000
6054 Verifying Checksum ... OK
6056 => bootm 40100000 40200000
6057 ## Booting Linux kernel at 40100000 ...
6058 Image Name: 2.2.13 for initrd on TQM850L
6059 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6060 Data Size: 335725 Bytes = 327 kB = 0 MB
6061 Load Address: 00000000
6062 Entry Point: 0000000c
6063 Verifying Checksum ... OK
6064 Uncompressing Kernel Image ... OK
6065 ## Loading RAMDisk Image at 40200000 ...
6066 Image Name: Simple Ramdisk Image
6067 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6068 Data Size: 566530 Bytes = 553 kB = 0 MB
6069 Load Address: 00000000
6070 Entry Point: 00000000
6071 Verifying Checksum ... OK
6072 Loading Ramdisk ... OK
6073 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
6074 Boot arguments: root=/dev/ram
6075 time_init: decrementer frequency = 187500000/60
6076 Calibrating delay loop... 49.77 BogoMIPS
6078 RAMDISK: Compressed image found at block 0
6079 VFS: Mounted root (ext2 filesystem).
6083 Boot Linux and pass a flat device tree:
6086 First, U-Boot must be compiled with the appropriate defines. See the section
6087 titled "Linux Kernel Interface" above for a more in depth explanation. The
6088 following is an example of how to start a kernel and pass an updated
6094 oft=oftrees/mpc8540ads.dtb
6095 => tftp $oftaddr $oft
6096 Speed: 1000, full duplex
6098 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6099 Filename 'oftrees/mpc8540ads.dtb'.
6100 Load address: 0x300000
6103 Bytes transferred = 4106 (100a hex)
6104 => tftp $loadaddr $bootfile
6105 Speed: 1000, full duplex
6107 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6109 Load address: 0x200000
6110 Loading:############
6112 Bytes transferred = 1029407 (fb51f hex)
6117 => bootm $loadaddr - $oftaddr
6118 ## Booting image at 00200000 ...
6119 Image Name: Linux-2.6.17-dirty
6120 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6121 Data Size: 1029343 Bytes = 1005.2 kB
6122 Load Address: 00000000
6123 Entry Point: 00000000
6124 Verifying Checksum ... OK
6125 Uncompressing Kernel Image ... OK
6126 Booting using flat device tree at 0x300000
6127 Using MPC85xx ADS machine description
6128 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6132 More About U-Boot Image Types:
6133 ------------------------------
6135 U-Boot supports the following image types:
6137 "Standalone Programs" are directly runnable in the environment
6138 provided by U-Boot; it is expected that (if they behave
6139 well) you can continue to work in U-Boot after return from
6140 the Standalone Program.
6141 "OS Kernel Images" are usually images of some Embedded OS which
6142 will take over control completely. Usually these programs
6143 will install their own set of exception handlers, device
6144 drivers, set up the MMU, etc. - this means, that you cannot
6145 expect to re-enter U-Boot except by resetting the CPU.
6146 "RAMDisk Images" are more or less just data blocks, and their
6147 parameters (address, size) are passed to an OS kernel that is
6149 "Multi-File Images" contain several images, typically an OS
6150 (Linux) kernel image and one or more data images like
6151 RAMDisks. This construct is useful for instance when you want
6152 to boot over the network using BOOTP etc., where the boot
6153 server provides just a single image file, but you want to get
6154 for instance an OS kernel and a RAMDisk image.
6156 "Multi-File Images" start with a list of image sizes, each
6157 image size (in bytes) specified by an "uint32_t" in network
6158 byte order. This list is terminated by an "(uint32_t)0".
6159 Immediately after the terminating 0 follow the images, one by
6160 one, all aligned on "uint32_t" boundaries (size rounded up to
6161 a multiple of 4 bytes).
6163 "Firmware Images" are binary images containing firmware (like
6164 U-Boot or FPGA images) which usually will be programmed to
6167 "Script files" are command sequences that will be executed by
6168 U-Boot's command interpreter; this feature is especially
6169 useful when you configure U-Boot to use a real shell (hush)
6170 as command interpreter.
6172 Booting the Linux zImage:
6173 -------------------------
6175 On some platforms, it's possible to boot Linux zImage. This is done
6176 using the "bootz" command. The syntax of "bootz" command is the same
6177 as the syntax of "bootm" command.
6179 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6180 kernel with raw initrd images. The syntax is slightly different, the
6181 address of the initrd must be augmented by it's size, in the following
6182 format: "<initrd addres>:<initrd size>".
6188 One of the features of U-Boot is that you can dynamically load and
6189 run "standalone" applications, which can use some resources of
6190 U-Boot like console I/O functions or interrupt services.
6192 Two simple examples are included with the sources:
6197 'examples/hello_world.c' contains a small "Hello World" Demo
6198 application; it is automatically compiled when you build U-Boot.
6199 It's configured to run at address 0x00040004, so you can play with it
6203 ## Ready for S-Record download ...
6204 ~>examples/hello_world.srec
6205 1 2 3 4 5 6 7 8 9 10 11 ...
6206 [file transfer complete]
6208 ## Start Addr = 0x00040004
6210 => go 40004 Hello World! This is a test.
6211 ## Starting application at 0x00040004 ...
6222 Hit any key to exit ...
6224 ## Application terminated, rc = 0x0
6226 Another example, which demonstrates how to register a CPM interrupt
6227 handler with the U-Boot code, can be found in 'examples/timer.c'.
6228 Here, a CPM timer is set up to generate an interrupt every second.
6229 The interrupt service routine is trivial, just printing a '.'
6230 character, but this is just a demo program. The application can be
6231 controlled by the following keys:
6233 ? - print current values og the CPM Timer registers
6234 b - enable interrupts and start timer
6235 e - stop timer and disable interrupts
6236 q - quit application
6239 ## Ready for S-Record download ...
6240 ~>examples/timer.srec
6241 1 2 3 4 5 6 7 8 9 10 11 ...
6242 [file transfer complete]
6244 ## Start Addr = 0x00040004
6247 ## Starting application at 0x00040004 ...
6250 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6253 [q, b, e, ?] Set interval 1000000 us
6256 [q, b, e, ?] ........
6257 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6260 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6263 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6266 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6268 [q, b, e, ?] ...Stopping timer
6270 [q, b, e, ?] ## Application terminated, rc = 0x0
6276 Over time, many people have reported problems when trying to use the
6277 "minicom" terminal emulation program for serial download. I (wd)
6278 consider minicom to be broken, and recommend not to use it. Under
6279 Unix, I recommend to use C-Kermit for general purpose use (and
6280 especially for kermit binary protocol download ("loadb" command), and
6281 use "cu" for S-Record download ("loads" command). See
6282 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6283 for help with kermit.
6286 Nevertheless, if you absolutely want to use it try adding this
6287 configuration to your "File transfer protocols" section:
6289 Name Program Name U/D FullScr IO-Red. Multi
6290 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6291 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6297 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6298 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6300 Building requires a cross environment; it is known to work on
6301 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6302 need gmake since the Makefiles are not compatible with BSD make).
6303 Note that the cross-powerpc package does not install include files;
6304 attempting to build U-Boot will fail because <machine/ansi.h> is
6305 missing. This file has to be installed and patched manually:
6307 # cd /usr/pkg/cross/powerpc-netbsd/include
6309 # ln -s powerpc machine
6310 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6311 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6313 Native builds *don't* work due to incompatibilities between native
6314 and U-Boot include files.
6316 Booting assumes that (the first part of) the image booted is a
6317 stage-2 loader which in turn loads and then invokes the kernel
6318 proper. Loader sources will eventually appear in the NetBSD source
6319 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6320 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6323 Implementation Internals:
6324 =========================
6326 The following is not intended to be a complete description of every
6327 implementation detail. However, it should help to understand the
6328 inner workings of U-Boot and make it easier to port it to custom
6332 Initial Stack, Global Data:
6333 ---------------------------
6335 The implementation of U-Boot is complicated by the fact that U-Boot
6336 starts running out of ROM (flash memory), usually without access to
6337 system RAM (because the memory controller is not initialized yet).
6338 This means that we don't have writable Data or BSS segments, and BSS
6339 is not initialized as zero. To be able to get a C environment working
6340 at all, we have to allocate at least a minimal stack. Implementation
6341 options for this are defined and restricted by the CPU used: Some CPU
6342 models provide on-chip memory (like the IMMR area on MPC8xx and
6343 MPC826x processors), on others (parts of) the data cache can be
6344 locked as (mis-) used as memory, etc.
6346 Chris Hallinan posted a good summary of these issues to the
6347 U-Boot mailing list:
6349 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6350 From: "Chris Hallinan" <clh@net1plus.com>
6351 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6354 Correct me if I'm wrong, folks, but the way I understand it
6355 is this: Using DCACHE as initial RAM for Stack, etc, does not
6356 require any physical RAM backing up the cache. The cleverness
6357 is that the cache is being used as a temporary supply of
6358 necessary storage before the SDRAM controller is setup. It's
6359 beyond the scope of this list to explain the details, but you
6360 can see how this works by studying the cache architecture and
6361 operation in the architecture and processor-specific manuals.
6363 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6364 is another option for the system designer to use as an
6365 initial stack/RAM area prior to SDRAM being available. Either
6366 option should work for you. Using CS 4 should be fine if your
6367 board designers haven't used it for something that would
6368 cause you grief during the initial boot! It is frequently not
6371 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6372 with your processor/board/system design. The default value
6373 you will find in any recent u-boot distribution in
6374 walnut.h should work for you. I'd set it to a value larger
6375 than your SDRAM module. If you have a 64MB SDRAM module, set
6376 it above 400_0000. Just make sure your board has no resources
6377 that are supposed to respond to that address! That code in
6378 start.S has been around a while and should work as is when
6379 you get the config right.
6384 It is essential to remember this, since it has some impact on the C
6385 code for the initialization procedures:
6387 * Initialized global data (data segment) is read-only. Do not attempt
6390 * Do not use any uninitialized global data (or implicitly initialized
6391 as zero data - BSS segment) at all - this is undefined, initiali-
6392 zation is performed later (when relocating to RAM).
6394 * Stack space is very limited. Avoid big data buffers or things like
6397 Having only the stack as writable memory limits means we cannot use
6398 normal global data to share information between the code. But it
6399 turned out that the implementation of U-Boot can be greatly
6400 simplified by making a global data structure (gd_t) available to all
6401 functions. We could pass a pointer to this data as argument to _all_
6402 functions, but this would bloat the code. Instead we use a feature of
6403 the GCC compiler (Global Register Variables) to share the data: we
6404 place a pointer (gd) to the global data into a register which we
6405 reserve for this purpose.
6407 When choosing a register for such a purpose we are restricted by the
6408 relevant (E)ABI specifications for the current architecture, and by
6409 GCC's implementation.
6411 For PowerPC, the following registers have specific use:
6413 R2: reserved for system use
6414 R3-R4: parameter passing and return values
6415 R5-R10: parameter passing
6416 R13: small data area pointer
6420 (U-Boot also uses R12 as internal GOT pointer. r12
6421 is a volatile register so r12 needs to be reset when
6422 going back and forth between asm and C)
6424 ==> U-Boot will use R2 to hold a pointer to the global data
6426 Note: on PPC, we could use a static initializer (since the
6427 address of the global data structure is known at compile time),
6428 but it turned out that reserving a register results in somewhat
6429 smaller code - although the code savings are not that big (on
6430 average for all boards 752 bytes for the whole U-Boot image,
6431 624 text + 127 data).
6433 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6434 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6436 ==> U-Boot will use P3 to hold a pointer to the global data
6438 On ARM, the following registers are used:
6440 R0: function argument word/integer result
6441 R1-R3: function argument word
6442 R9: platform specific
6443 R10: stack limit (used only if stack checking is enabled)
6444 R11: argument (frame) pointer
6445 R12: temporary workspace
6448 R15: program counter
6450 ==> U-Boot will use R9 to hold a pointer to the global data
6452 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6454 On Nios II, the ABI is documented here:
6455 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6457 ==> U-Boot will use gp to hold a pointer to the global data
6459 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6460 to access small data sections, so gp is free.
6462 On NDS32, the following registers are used:
6464 R0-R1: argument/return
6466 R15: temporary register for assembler
6467 R16: trampoline register
6468 R28: frame pointer (FP)
6469 R29: global pointer (GP)
6470 R30: link register (LP)
6471 R31: stack pointer (SP)
6472 PC: program counter (PC)
6474 ==> U-Boot will use R10 to hold a pointer to the global data
6476 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6477 or current versions of GCC may "optimize" the code too much.
6482 U-Boot runs in system state and uses physical addresses, i.e. the
6483 MMU is not used either for address mapping nor for memory protection.
6485 The available memory is mapped to fixed addresses using the memory
6486 controller. In this process, a contiguous block is formed for each
6487 memory type (Flash, SDRAM, SRAM), even when it consists of several
6488 physical memory banks.
6490 U-Boot is installed in the first 128 kB of the first Flash bank (on
6491 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6492 booting and sizing and initializing DRAM, the code relocates itself
6493 to the upper end of DRAM. Immediately below the U-Boot code some
6494 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6495 configuration setting]. Below that, a structure with global Board
6496 Info data is placed, followed by the stack (growing downward).
6498 Additionally, some exception handler code is copied to the low 8 kB
6499 of DRAM (0x00000000 ... 0x00001FFF).
6501 So a typical memory configuration with 16 MB of DRAM could look like
6504 0x0000 0000 Exception Vector code
6507 0x0000 2000 Free for Application Use
6513 0x00FB FF20 Monitor Stack (Growing downward)
6514 0x00FB FFAC Board Info Data and permanent copy of global data
6515 0x00FC 0000 Malloc Arena
6518 0x00FE 0000 RAM Copy of Monitor Code
6519 ... eventually: LCD or video framebuffer
6520 ... eventually: pRAM (Protected RAM - unchanged by reset)
6521 0x00FF FFFF [End of RAM]
6524 System Initialization:
6525 ----------------------
6527 In the reset configuration, U-Boot starts at the reset entry point
6528 (on most PowerPC systems at address 0x00000100). Because of the reset
6529 configuration for CS0# this is a mirror of the on board Flash memory.
6530 To be able to re-map memory U-Boot then jumps to its link address.
6531 To be able to implement the initialization code in C, a (small!)
6532 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6533 which provide such a feature like MPC8xx or MPC8260), or in a locked
6534 part of the data cache. After that, U-Boot initializes the CPU core,
6535 the caches and the SIU.
6537 Next, all (potentially) available memory banks are mapped using a
6538 preliminary mapping. For example, we put them on 512 MB boundaries
6539 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6540 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6541 programmed for SDRAM access. Using the temporary configuration, a
6542 simple memory test is run that determines the size of the SDRAM
6545 When there is more than one SDRAM bank, and the banks are of
6546 different size, the largest is mapped first. For equal size, the first
6547 bank (CS2#) is mapped first. The first mapping is always for address
6548 0x00000000, with any additional banks following immediately to create
6549 contiguous memory starting from 0.
6551 Then, the monitor installs itself at the upper end of the SDRAM area
6552 and allocates memory for use by malloc() and for the global Board
6553 Info data; also, the exception vector code is copied to the low RAM
6554 pages, and the final stack is set up.
6556 Only after this relocation will you have a "normal" C environment;
6557 until that you are restricted in several ways, mostly because you are
6558 running from ROM, and because the code will have to be relocated to a
6562 U-Boot Porting Guide:
6563 ----------------------
6565 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6569 int main(int argc, char *argv[])
6571 sighandler_t no_more_time;
6573 signal(SIGALRM, no_more_time);
6574 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6576 if (available_money > available_manpower) {
6577 Pay consultant to port U-Boot;
6581 Download latest U-Boot source;
6583 Subscribe to u-boot mailing list;
6586 email("Hi, I am new to U-Boot, how do I get started?");
6589 Read the README file in the top level directory;
6590 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6591 Read applicable doc/*.README;
6592 Read the source, Luke;
6593 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6596 if (available_money > toLocalCurrency ($2500))
6599 Add a lot of aggravation and time;
6601 if (a similar board exists) { /* hopefully... */
6602 cp -a board/<similar> board/<myboard>
6603 cp include/configs/<similar>.h include/configs/<myboard>.h
6605 Create your own board support subdirectory;
6606 Create your own board include/configs/<myboard>.h file;
6608 Edit new board/<myboard> files
6609 Edit new include/configs/<myboard>.h
6614 Add / modify source code;
6618 email("Hi, I am having problems...");
6620 Send patch file to the U-Boot email list;
6621 if (reasonable critiques)
6622 Incorporate improvements from email list code review;
6624 Defend code as written;
6630 void no_more_time (int sig)
6639 All contributions to U-Boot should conform to the Linux kernel
6640 coding style; see the file "Documentation/CodingStyle" and the script
6641 "scripts/Lindent" in your Linux kernel source directory.
6643 Source files originating from a different project (for example the
6644 MTD subsystem) are generally exempt from these guidelines and are not
6645 reformatted to ease subsequent migration to newer versions of those
6648 Please note that U-Boot is implemented in C (and to some small parts in
6649 Assembler); no C++ is used, so please do not use C++ style comments (//)
6652 Please also stick to the following formatting rules:
6653 - remove any trailing white space
6654 - use TAB characters for indentation and vertical alignment, not spaces
6655 - make sure NOT to use DOS '\r\n' line feeds
6656 - do not add more than 2 consecutive empty lines to source files
6657 - do not add trailing empty lines to source files
6659 Submissions which do not conform to the standards may be returned
6660 with a request to reformat the changes.
6666 Since the number of patches for U-Boot is growing, we need to
6667 establish some rules. Submissions which do not conform to these rules
6668 may be rejected, even when they contain important and valuable stuff.
6670 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6672 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6673 see http://lists.denx.de/mailman/listinfo/u-boot
6675 When you send a patch, please include the following information with
6678 * For bug fixes: a description of the bug and how your patch fixes
6679 this bug. Please try to include a way of demonstrating that the
6680 patch actually fixes something.
6682 * For new features: a description of the feature and your
6685 * A CHANGELOG entry as plaintext (separate from the patch)
6687 * For major contributions, your entry to the CREDITS file
6689 * When you add support for a new board, don't forget to add a
6690 maintainer e-mail address to the boards.cfg file, too.
6692 * If your patch adds new configuration options, don't forget to
6693 document these in the README file.
6695 * The patch itself. If you are using git (which is *strongly*
6696 recommended) you can easily generate the patch using the
6697 "git format-patch". If you then use "git send-email" to send it to
6698 the U-Boot mailing list, you will avoid most of the common problems
6699 with some other mail clients.
6701 If you cannot use git, use "diff -purN OLD NEW". If your version of
6702 diff does not support these options, then get the latest version of
6705 The current directory when running this command shall be the parent
6706 directory of the U-Boot source tree (i. e. please make sure that
6707 your patch includes sufficient directory information for the
6710 We prefer patches as plain text. MIME attachments are discouraged,
6711 and compressed attachments must not be used.
6713 * If one logical set of modifications affects or creates several
6714 files, all these changes shall be submitted in a SINGLE patch file.
6716 * Changesets that contain different, unrelated modifications shall be
6717 submitted as SEPARATE patches, one patch per changeset.
6722 * Before sending the patch, run the MAKEALL script on your patched
6723 source tree and make sure that no errors or warnings are reported
6724 for any of the boards.
6726 * Keep your modifications to the necessary minimum: A patch
6727 containing several unrelated changes or arbitrary reformats will be
6728 returned with a request to re-formatting / split it.
6730 * If you modify existing code, make sure that your new code does not
6731 add to the memory footprint of the code ;-) Small is beautiful!
6732 When adding new features, these should compile conditionally only
6733 (using #ifdef), and the resulting code with the new feature
6734 disabled must not need more memory than the old code without your
6737 * Remember that there is a size limit of 100 kB per message on the
6738 u-boot mailing list. Bigger patches will be moderated. If they are
6739 reasonable and not too big, they will be acknowledged. But patches
6740 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob