2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_defconfig".
257 Example: For a TQM823L module type:
260 make TQM823L_defconfig
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
264 directory according to the instructions in cogent/README.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Marvell Family Member
325 CONFIG_SYS_MVFS - define it if you want to enable
326 multiple fs option at one time
327 for marvell soc family
329 - MPC824X Family Member (if CONFIG_MPC824X is defined)
330 Define exactly one of
331 CONFIG_MPC8240, CONFIG_MPC8245
333 - 8xx CPU Options: (if using an MPC8xx CPU)
334 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
335 get_gclk_freq() cannot work
336 e.g. if there is no 32KHz
337 reference PIT/RTC clock
338 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
341 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
342 CONFIG_SYS_8xx_CPUCLK_MIN
343 CONFIG_SYS_8xx_CPUCLK_MAX
344 CONFIG_8xx_CPUCLK_DEFAULT
345 See doc/README.MPC866
347 CONFIG_SYS_MEASURE_CPUCLK
349 Define this to measure the actual CPU clock instead
350 of relying on the correctness of the configured
351 values. Mostly useful for board bringup to make sure
352 the PLL is locked at the intended frequency. Note
353 that this requires a (stable) reference clock (32 kHz
354 RTC clock or CONFIG_SYS_8XX_XIN)
356 CONFIG_SYS_DELAYED_ICACHE
358 Define this option if you want to enable the
359 ICache only when Code runs from RAM.
364 Specifies that the core is a 64-bit PowerPC implementation (implements
365 the "64" category of the Power ISA). This is necessary for ePAPR
366 compliance, among other possible reasons.
368 CONFIG_SYS_FSL_TBCLK_DIV
370 Defines the core time base clock divider ratio compared to the
371 system clock. On most PQ3 devices this is 8, on newer QorIQ
372 devices it can be 16 or 32. The ratio varies from SoC to Soc.
374 CONFIG_SYS_FSL_PCIE_COMPAT
376 Defines the string to utilize when trying to match PCIe device
377 tree nodes for the given platform.
379 CONFIG_SYS_PPC_E500_DEBUG_TLB
381 Enables a temporary TLB entry to be used during boot to work
382 around limitations in e500v1 and e500v2 external debugger
383 support. This reduces the portions of the boot code where
384 breakpoints and single stepping do not work. The value of this
385 symbol should be set to the TLB1 entry to be used for this
388 CONFIG_SYS_FSL_ERRATUM_A004510
390 Enables a workaround for erratum A004510. If set,
391 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
392 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
394 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
395 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
397 Defines one or two SoC revisions (low 8 bits of SVR)
398 for which the A004510 workaround should be applied.
400 The rest of SVR is either not relevant to the decision
401 of whether the erratum is present (e.g. p2040 versus
402 p2041) or is implied by the build target, which controls
403 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
405 See Freescale App Note 4493 for more information about
408 CONFIG_A003399_NOR_WORKAROUND
409 Enables a workaround for IFC erratum A003399. It is only
410 requred during NOR boot.
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 CONFIG_SYS_FSL_DSP_DDR_ADDR
418 This value denotes start offset of DDR memory which is
419 connected exclusively to the DSP cores.
421 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
422 This value denotes start offset of M2 memory
423 which is directly connected to the DSP core.
425 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
426 This value denotes start offset of M3 memory which is directly
427 connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
433 Single Source Clock is clocking mode present in some of FSL SoC's.
434 In this mode, a single differential clock is used to supply
435 clocks to the sysclock, ddrclock and usbclock.
437 CONFIG_SYS_CPC_REINIT_F
438 This CONFIG is defined when the CPC is configured as SRAM at the
439 time of U-boot entry and is required to be re-initialized.
442 Inidcates this SoC supports deep sleep feature. If deep sleep is
443 supported, core will start to execute uboot when wakes up.
445 - Generic CPU options:
446 CONFIG_SYS_GENERIC_GLOBAL_DATA
447 Defines global data is initialized in generic board board_init_f().
448 If this macro is defined, global data is created and cleared in
449 generic board board_init_f(). Without this macro, architecture/board
450 should initialize global data before calling board_init_f().
452 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
454 Defines the endianess of the CPU. Implementation of those
455 values is arch specific.
458 Freescale DDR driver in use. This type of DDR controller is
459 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
462 CONFIG_SYS_FSL_DDR_ADDR
463 Freescale DDR memory-mapped register base.
465 CONFIG_SYS_FSL_DDR_EMU
466 Specify emulator support for DDR. Some DDR features such as
467 deskew training are not available.
469 CONFIG_SYS_FSL_DDRC_GEN1
470 Freescale DDR1 controller.
472 CONFIG_SYS_FSL_DDRC_GEN2
473 Freescale DDR2 controller.
475 CONFIG_SYS_FSL_DDRC_GEN3
476 Freescale DDR3 controller.
478 CONFIG_SYS_FSL_DDRC_GEN4
479 Freescale DDR4 controller.
481 CONFIG_SYS_FSL_DDRC_ARM_GEN3
482 Freescale DDR3 controller for ARM-based SoCs.
485 Board config to use DDR1. It can be enabled for SoCs with
486 Freescale DDR1 or DDR2 controllers, depending on the board
490 Board config to use DDR2. It can be eanbeld for SoCs with
491 Freescale DDR2 or DDR3 controllers, depending on the board
495 Board config to use DDR3. It can be enabled for SoCs with
496 Freescale DDR3 or DDR3L controllers.
499 Board config to use DDR3L. It can be enabled for SoCs with
503 Board config to use DDR4. It can be enabled for SoCs with
506 CONFIG_SYS_FSL_IFC_BE
507 Defines the IFC controller register space as Big Endian
509 CONFIG_SYS_FSL_IFC_LE
510 Defines the IFC controller register space as Little Endian
512 CONFIG_SYS_FSL_PBL_PBI
513 It enables addition of RCW (Power on reset configuration) in built image.
514 Please refer doc/README.pblimage for more details
516 CONFIG_SYS_FSL_PBL_RCW
517 It adds PBI(pre-boot instructions) commands in u-boot build image.
518 PBI commands can be used to configure SoC before it starts the execution.
519 Please refer doc/README.pblimage for more details
522 It adds a target to create boot binary having SPL binary in PBI format
523 concatenated with u-boot binary.
525 CONFIG_SYS_FSL_DDR_BE
526 Defines the DDR controller register space as Big Endian
528 CONFIG_SYS_FSL_DDR_LE
529 Defines the DDR controller register space as Little Endian
531 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
532 Physical address from the view of DDR controllers. It is the
533 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
534 it could be different for ARM SoCs.
536 CONFIG_SYS_FSL_DDR_INTLV_256B
537 DDR controller interleaving on 256-byte. This is a special
538 interleaving mode, handled by Dickens for Freescale layerscape
541 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
542 Number of controllers used as main memory.
544 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
545 Number of controllers used for other than main memory.
547 CONFIG_SYS_FSL_SEC_BE
548 Defines the SEC controller register space as Big Endian
550 CONFIG_SYS_FSL_SEC_LE
551 Defines the SEC controller register space as Little Endian
553 - Intel Monahans options:
554 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
556 Defines the Monahans run mode to oscillator
557 ratio. Valid values are 8, 16, 24, 31. The core
558 frequency is this value multiplied by 13 MHz.
560 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
562 Defines the Monahans turbo mode to oscillator
563 ratio. Valid values are 1 (default if undefined) and
564 2. The core frequency as calculated above is multiplied
568 CONFIG_SYS_INIT_SP_OFFSET
570 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
571 pointer. This is needed for the temporary stack before
574 CONFIG_SYS_MIPS_CACHE_MODE
576 Cache operation mode for the MIPS CPU.
577 See also arch/mips/include/asm/mipsregs.h.
579 CONF_CM_CACHABLE_NO_WA
582 CONF_CM_CACHABLE_NONCOHERENT
586 CONF_CM_CACHABLE_ACCELERATED
588 CONFIG_SYS_XWAY_EBU_BOOTCFG
590 Special option for Lantiq XWAY SoCs for booting from NOR flash.
591 See also arch/mips/cpu/mips32/start.S.
593 CONFIG_XWAY_SWAP_BYTES
595 Enable compilation of tools/xway-swap-bytes needed for Lantiq
596 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
597 be swapped if a flash programmer is used.
600 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
602 Select high exception vectors of the ARM core, e.g., do not
603 clear the V bit of the c1 register of CP15.
605 CONFIG_SYS_THUMB_BUILD
607 Use this flag to build U-Boot using the Thumb instruction
608 set for ARM architectures. Thumb instruction set provides
609 better code density. For ARM architectures that support
610 Thumb2 this flag will result in Thumb2 code generated by
613 CONFIG_ARM_ERRATA_716044
614 CONFIG_ARM_ERRATA_742230
615 CONFIG_ARM_ERRATA_743622
616 CONFIG_ARM_ERRATA_751472
617 CONFIG_ARM_ERRATA_794072
618 CONFIG_ARM_ERRATA_761320
620 If set, the workarounds for these ARM errata are applied early
621 during U-Boot startup. Note that these options force the
622 workarounds to be applied; no CPU-type/version detection
623 exists, unlike the similar options in the Linux kernel. Do not
624 set these options unless they apply!
627 Driver model is a new framework for devices in U-Boot
628 introduced in early 2014. U-Boot is being progressively
629 moved over to this. It offers a consistent device structure,
630 supports grouping devices into classes and has built-in
631 handling of platform data and device tree.
633 To enable transition to driver model in a relatively
634 painful fashion, each subsystem can be independently
635 switched between the legacy/ad-hoc approach and the new
636 driver model using the options below. Also, many uclass
637 interfaces include compatibility features which may be
638 removed once the conversion of that subsystem is complete.
639 As a result, the API provided by the subsystem may in fact
640 not change with driver model.
642 See doc/driver-model/README.txt for more information.
646 Enable driver model. This brings in the core support,
647 including scanning of platform data on start-up. If
648 CONFIG_OF_CONTROL is enabled, the device tree will be
649 scanned also when available.
653 Enable driver model test commands. These allow you to print
654 out the driver model tree and the uclasses.
658 Enable some demo devices and the 'demo' command. These are
659 really only useful for playing around while trying to
660 understand driver model in sandbox.
664 Enable driver model in SPL. You will need to provide a
665 suitable malloc() implementation. If you are not using the
666 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
667 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
668 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
669 In most cases driver model will only allocate a few uclasses
670 and devices in SPL, so 1KB should be enable. See
671 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
676 Enable driver model for serial. This replaces
677 drivers/serial/serial.c with the serial uclass, which
678 implements serial_putc() etc. The uclass interface is
679 defined in include/serial.h.
683 Enable driver model for GPIO access. The standard GPIO
684 interface (gpio_get_value(), etc.) is then implemented by
685 the GPIO uclass. Drivers provide methods to query the
686 particular GPIOs that they provide. The uclass interface
687 is defined in include/asm-generic/gpio.h.
691 Enable driver model for SPI. The SPI slave interface
692 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
693 the SPI uclass. Drivers provide methods to access the SPI
694 buses that they control. The uclass interface is defined in
695 include/spi.h. The existing spi_slave structure is attached
696 as 'parent data' to every slave on each bus. Slaves
697 typically use driver-private data instead of extending the
702 Enable driver model for SPI flash. This SPI flash interface
703 (spi_flash_probe(), spi_flash_write(), etc.) is then
704 implemented by the SPI flash uclass. There is one standard
705 SPI flash driver which knows how to probe most chips
706 supported by U-Boot. The uclass interface is defined in
707 include/spi_flash.h, but is currently fully compatible
708 with the old interface to avoid confusion and duplication
709 during the transition parent. SPI and SPI flash must be
710 enabled together (it is not possible to use driver model
711 for one and not the other).
715 Enable driver model for the Chrome OS EC interface. This
716 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
717 but otherwise makes few changes. Since cros_ec also supports
718 I2C and LPC (which don't support driver model yet), a full
719 conversion is not yet possible.
722 ** Code size options: The following options are enabled by
723 default except in SPL. Enable them explicitly to get these
728 Enable the dm_warn() function. This can use up quite a bit
729 of space for its strings.
733 Enable registering a serial device with the stdio library.
735 CONFIG_DM_DEVICE_REMOVE
737 Enable removing of devices.
740 - Linux Kernel Interface:
743 U-Boot stores all clock information in Hz
744 internally. For binary compatibility with older Linux
745 kernels (which expect the clocks passed in the
746 bd_info data to be in MHz) the environment variable
747 "clocks_in_mhz" can be defined so that U-Boot
748 converts clock data to MHZ before passing it to the
750 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
751 "clocks_in_mhz=1" is automatically included in the
754 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
756 When transferring memsize parameter to linux, some versions
757 expect it to be in bytes, others in MB.
758 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
762 New kernel versions are expecting firmware settings to be
763 passed using flattened device trees (based on open firmware
767 * New libfdt-based support
768 * Adds the "fdt" command
769 * The bootm command automatically updates the fdt
771 OF_CPU - The proper name of the cpus node (only required for
772 MPC512X and MPC5xxx based boards).
773 OF_SOC - The proper name of the soc node (only required for
774 MPC512X and MPC5xxx based boards).
775 OF_TBCLK - The timebase frequency.
776 OF_STDOUT_PATH - The path to the console device
778 boards with QUICC Engines require OF_QE to set UCC MAC
781 CONFIG_OF_BOARD_SETUP
783 Board code has addition modification that it wants to make
784 to the flat device tree before handing it off to the kernel
786 CONFIG_OF_SYSTEM_SETUP
788 Other code has addition modification that it wants to make
789 to the flat device tree before handing it off to the kernel.
790 This causes ft_system_setup() to be called before booting
795 This define fills in the correct boot CPU in the boot
796 param header, the default value is zero if undefined.
800 U-Boot can detect if an IDE device is present or not.
801 If not, and this new config option is activated, U-Boot
802 removes the ATA node from the DTS before booting Linux,
803 so the Linux IDE driver does not probe the device and
804 crash. This is needed for buggy hardware (uc101) where
805 no pull down resistor is connected to the signal IDE5V_DD7.
807 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
809 This setting is mandatory for all boards that have only one
810 machine type and must be used to specify the machine type
811 number as it appears in the ARM machine registry
812 (see http://www.arm.linux.org.uk/developer/machines/).
813 Only boards that have multiple machine types supported
814 in a single configuration file and the machine type is
815 runtime discoverable, do not have to use this setting.
817 - vxWorks boot parameters:
819 bootvx constructs a valid bootline using the following
820 environments variables: bootfile, ipaddr, serverip, hostname.
821 It loads the vxWorks image pointed bootfile.
823 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
824 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
825 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
826 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
828 CONFIG_SYS_VXWORKS_ADD_PARAMS
830 Add it at the end of the bootline. E.g "u=username pw=secret"
832 Note: If a "bootargs" environment is defined, it will overwride
833 the defaults discussed just above.
835 - Cache Configuration:
836 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
837 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
838 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
840 - Cache Configuration for ARM:
841 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
843 CONFIG_SYS_PL310_BASE - Physical base address of PL310
844 controller register space
849 Define this if you want support for Amba PrimeCell PL010 UARTs.
853 Define this if you want support for Amba PrimeCell PL011 UARTs.
857 If you have Amba PrimeCell PL011 UARTs, set this variable to
858 the clock speed of the UARTs.
862 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
863 define this to a list of base addresses for each (supported)
864 port. See e.g. include/configs/versatile.h
866 CONFIG_PL011_SERIAL_RLCR
868 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
869 have separate receive and transmit line control registers. Set
870 this variable to initialize the extra register.
872 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
874 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
875 boot loader that has already initialized the UART. Define this
876 variable to flush the UART at init time.
878 CONFIG_SERIAL_HW_FLOW_CONTROL
880 Define this variable to enable hw flow control in serial driver.
881 Current user of this option is drivers/serial/nsl16550.c driver
884 Depending on board, define exactly one serial port
885 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
886 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
887 console by defining CONFIG_8xx_CONS_NONE
889 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
890 port routines must be defined elsewhere
891 (i.e. serial_init(), serial_getc(), ...)
894 Enables console device for a color framebuffer. Needs following
895 defines (cf. smiLynxEM, i8042)
896 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
898 VIDEO_HW_RECTFILL graphic chip supports
901 VIDEO_HW_BITBLT graphic chip supports
902 bit-blit (cf. smiLynxEM)
903 VIDEO_VISIBLE_COLS visible pixel columns
905 VIDEO_VISIBLE_ROWS visible pixel rows
906 VIDEO_PIXEL_SIZE bytes per pixel
907 VIDEO_DATA_FORMAT graphic data format
908 (0-5, cf. cfb_console.c)
909 VIDEO_FB_ADRS framebuffer address
910 VIDEO_KBD_INIT_FCT keyboard int fct
911 (i.e. i8042_kbd_init())
912 VIDEO_TSTC_FCT test char fct
914 VIDEO_GETC_FCT get char fct
916 CONFIG_CONSOLE_CURSOR cursor drawing on/off
917 (requires blink timer
919 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
920 CONFIG_CONSOLE_TIME display time/date info in
922 (requires CONFIG_CMD_DATE)
923 CONFIG_VIDEO_LOGO display Linux logo in
925 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
926 linux_logo.h for logo.
927 Requires CONFIG_VIDEO_LOGO
928 CONFIG_CONSOLE_EXTRA_INFO
929 additional board info beside
932 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
933 a limited number of ANSI escape sequences (cursor control,
934 erase functions and limited graphics rendition control).
936 When CONFIG_CFB_CONSOLE is defined, video console is
937 default i/o. Serial console can be forced with
938 environment 'console=serial'.
940 When CONFIG_SILENT_CONSOLE is defined, all console
941 messages (by U-Boot and Linux!) can be silenced with
942 the "silent" environment variable. See
943 doc/README.silent for more information.
945 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
947 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
951 CONFIG_BAUDRATE - in bps
952 Select one of the baudrates listed in
953 CONFIG_SYS_BAUDRATE_TABLE, see below.
954 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
956 - Console Rx buffer length
957 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
958 the maximum receive buffer length for the SMC.
959 This option is actual only for 82xx and 8xx possible.
960 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
961 must be defined, to setup the maximum idle timeout for
964 - Pre-Console Buffer:
965 Prior to the console being initialised (i.e. serial UART
966 initialised etc) all console output is silently discarded.
967 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
968 buffer any console messages prior to the console being
969 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
970 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
971 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
972 bytes are output before the console is initialised, the
973 earlier bytes are discarded.
975 'Sane' compilers will generate smaller code if
976 CONFIG_PRE_CON_BUF_SZ is a power of 2
978 - Safe printf() functions
979 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
980 the printf() functions. These are defined in
981 include/vsprintf.h and include snprintf(), vsnprintf() and
982 so on. Code size increase is approximately 300-500 bytes.
983 If this option is not given then these functions will
984 silently discard their buffer size argument - this means
985 you are not getting any overflow checking in this case.
987 - Boot Delay: CONFIG_BOOTDELAY - in seconds
988 Delay before automatically booting the default image;
989 set to -1 to disable autoboot.
990 set to -2 to autoboot with no delay and not check for abort
991 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
993 See doc/README.autoboot for these options that
994 work with CONFIG_BOOTDELAY. None are required.
995 CONFIG_BOOT_RETRY_TIME
996 CONFIG_BOOT_RETRY_MIN
997 CONFIG_AUTOBOOT_KEYED
998 CONFIG_AUTOBOOT_PROMPT
999 CONFIG_AUTOBOOT_DELAY_STR
1000 CONFIG_AUTOBOOT_STOP_STR
1001 CONFIG_AUTOBOOT_DELAY_STR2
1002 CONFIG_AUTOBOOT_STOP_STR2
1003 CONFIG_ZERO_BOOTDELAY_CHECK
1004 CONFIG_RESET_TO_RETRY
1008 Only needed when CONFIG_BOOTDELAY is enabled;
1009 define a command string that is automatically executed
1010 when no character is read on the console interface
1011 within "Boot Delay" after reset.
1014 This can be used to pass arguments to the bootm
1015 command. The value of CONFIG_BOOTARGS goes into the
1016 environment value "bootargs".
1018 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1019 The value of these goes into the environment as
1020 "ramboot" and "nfsboot" respectively, and can be used
1021 as a convenience, when switching between booting from
1025 CONFIG_BOOTCOUNT_LIMIT
1026 Implements a mechanism for detecting a repeating reboot
1028 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1030 CONFIG_BOOTCOUNT_ENV
1031 If no softreset save registers are found on the hardware
1032 "bootcount" is stored in the environment. To prevent a
1033 saveenv on all reboots, the environment variable
1034 "upgrade_available" is used. If "upgrade_available" is
1035 0, "bootcount" is always 0, if "upgrade_available" is
1036 1 "bootcount" is incremented in the environment.
1037 So the Userspace Applikation must set the "upgrade_available"
1038 and "bootcount" variable to 0, if a boot was successfully.
1040 - Pre-Boot Commands:
1043 When this option is #defined, the existence of the
1044 environment variable "preboot" will be checked
1045 immediately before starting the CONFIG_BOOTDELAY
1046 countdown and/or running the auto-boot command resp.
1047 entering interactive mode.
1049 This feature is especially useful when "preboot" is
1050 automatically generated or modified. For an example
1051 see the LWMON board specific code: here "preboot" is
1052 modified when the user holds down a certain
1053 combination of keys on the (special) keyboard when
1056 - Serial Download Echo Mode:
1058 If defined to 1, all characters received during a
1059 serial download (using the "loads" command) are
1060 echoed back. This might be needed by some terminal
1061 emulations (like "cu"), but may as well just take
1062 time on others. This setting #define's the initial
1063 value of the "loads_echo" environment variable.
1065 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1066 CONFIG_KGDB_BAUDRATE
1067 Select one of the baudrates listed in
1068 CONFIG_SYS_BAUDRATE_TABLE, see below.
1070 - Monitor Functions:
1071 Monitor commands can be included or excluded
1072 from the build by using the #include files
1073 <config_cmd_all.h> and #undef'ing unwanted
1074 commands, or using <config_cmd_default.h>
1075 and augmenting with additional #define's
1076 for wanted commands.
1078 The default command configuration includes all commands
1079 except those marked below with a "*".
1081 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1082 CONFIG_CMD_ASKENV * ask for env variable
1083 CONFIG_CMD_BDI bdinfo
1084 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1085 CONFIG_CMD_BMP * BMP support
1086 CONFIG_CMD_BSP * Board specific commands
1087 CONFIG_CMD_BOOTD bootd
1088 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1089 CONFIG_CMD_CACHE * icache, dcache
1090 CONFIG_CMD_CLK * clock command support
1091 CONFIG_CMD_CONSOLE coninfo
1092 CONFIG_CMD_CRC32 * crc32
1093 CONFIG_CMD_DATE * support for RTC, date/time...
1094 CONFIG_CMD_DHCP * DHCP support
1095 CONFIG_CMD_DIAG * Diagnostics
1096 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1097 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1098 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1099 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1100 CONFIG_CMD_DTT * Digital Therm and Thermostat
1101 CONFIG_CMD_ECHO echo arguments
1102 CONFIG_CMD_EDITENV edit env variable
1103 CONFIG_CMD_EEPROM * EEPROM read/write support
1104 CONFIG_CMD_ELF * bootelf, bootvx
1105 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1106 CONFIG_CMD_ENV_FLAGS * display details about env flags
1107 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1108 CONFIG_CMD_EXPORTENV * export the environment
1109 CONFIG_CMD_EXT2 * ext2 command support
1110 CONFIG_CMD_EXT4 * ext4 command support
1111 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1112 that work for multiple fs types
1113 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1114 CONFIG_CMD_SAVEENV saveenv
1115 CONFIG_CMD_FDC * Floppy Disk Support
1116 CONFIG_CMD_FAT * FAT command support
1117 CONFIG_CMD_FLASH flinfo, erase, protect
1118 CONFIG_CMD_FPGA FPGA device initialization support
1119 CONFIG_CMD_FUSE * Device fuse support
1120 CONFIG_CMD_GETTIME * Get time since boot
1121 CONFIG_CMD_GO * the 'go' command (exec code)
1122 CONFIG_CMD_GREPENV * search environment
1123 CONFIG_CMD_HASH * calculate hash / digest
1124 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1125 CONFIG_CMD_I2C * I2C serial bus support
1126 CONFIG_CMD_IDE * IDE harddisk support
1127 CONFIG_CMD_IMI iminfo
1128 CONFIG_CMD_IMLS List all images found in NOR flash
1129 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1130 CONFIG_CMD_IMMAP * IMMR dump support
1131 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1132 CONFIG_CMD_IMPORTENV * import an environment
1133 CONFIG_CMD_INI * import data from an ini file into the env
1134 CONFIG_CMD_IRQ * irqinfo
1135 CONFIG_CMD_ITEST Integer/string test of 2 values
1136 CONFIG_CMD_JFFS2 * JFFS2 Support
1137 CONFIG_CMD_KGDB * kgdb
1138 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1139 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1141 CONFIG_CMD_LOADB loadb
1142 CONFIG_CMD_LOADS loads
1143 CONFIG_CMD_MD5SUM * print md5 message digest
1144 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1145 CONFIG_CMD_MEMINFO * Display detailed memory information
1146 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1148 CONFIG_CMD_MEMTEST * mtest
1149 CONFIG_CMD_MISC Misc functions like sleep etc
1150 CONFIG_CMD_MMC * MMC memory mapped support
1151 CONFIG_CMD_MII * MII utility commands
1152 CONFIG_CMD_MTDPARTS * MTD partition support
1153 CONFIG_CMD_NAND * NAND support
1154 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1155 CONFIG_CMD_NFS NFS support
1156 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1157 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1158 CONFIG_CMD_PCI * pciinfo
1159 CONFIG_CMD_PCMCIA * PCMCIA support
1160 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1162 CONFIG_CMD_PORTIO * Port I/O
1163 CONFIG_CMD_READ * Read raw data from partition
1164 CONFIG_CMD_REGINFO * Register dump
1165 CONFIG_CMD_RUN run command in env variable
1166 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1167 CONFIG_CMD_SAVES * save S record dump
1168 CONFIG_CMD_SCSI * SCSI Support
1169 CONFIG_CMD_SDRAM * print SDRAM configuration information
1170 (requires CONFIG_CMD_I2C)
1171 CONFIG_CMD_SETGETDCR Support for DCR Register access
1173 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1174 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1175 (requires CONFIG_CMD_MEMORY)
1176 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1177 CONFIG_CMD_SOURCE "source" command Support
1178 CONFIG_CMD_SPI * SPI serial bus support
1179 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1180 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1181 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1182 CONFIG_CMD_TIMER * access to the system tick timer
1183 CONFIG_CMD_USB * USB support
1184 CONFIG_CMD_CDP * Cisco Discover Protocol support
1185 CONFIG_CMD_MFSL * Microblaze FSL support
1186 CONFIG_CMD_XIMG Load part of Multi Image
1187 CONFIG_CMD_UUID * Generate random UUID or GUID string
1189 EXAMPLE: If you want all functions except of network
1190 support you can write:
1192 #include "config_cmd_all.h"
1193 #undef CONFIG_CMD_NET
1196 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1198 Note: Don't enable the "icache" and "dcache" commands
1199 (configuration option CONFIG_CMD_CACHE) unless you know
1200 what you (and your U-Boot users) are doing. Data
1201 cache cannot be enabled on systems like the 8xx or
1202 8260 (where accesses to the IMMR region must be
1203 uncached), and it cannot be disabled on all other
1204 systems where we (mis-) use the data cache to hold an
1205 initial stack and some data.
1208 XXX - this list needs to get updated!
1210 - Regular expression support:
1212 If this variable is defined, U-Boot is linked against
1213 the SLRE (Super Light Regular Expression) library,
1214 which adds regex support to some commands, as for
1215 example "env grep" and "setexpr".
1219 If this variable is defined, U-Boot will use a device tree
1220 to configure its devices, instead of relying on statically
1221 compiled #defines in the board file. This option is
1222 experimental and only available on a few boards. The device
1223 tree is available in the global data as gd->fdt_blob.
1225 U-Boot needs to get its device tree from somewhere. This can
1226 be done using one of the two options below:
1229 If this variable is defined, U-Boot will embed a device tree
1230 binary in its image. This device tree file should be in the
1231 board directory and called <soc>-<board>.dts. The binary file
1232 is then picked up in board_init_f() and made available through
1233 the global data structure as gd->blob.
1236 If this variable is defined, U-Boot will build a device tree
1237 binary. It will be called u-boot.dtb. Architecture-specific
1238 code will locate it at run-time. Generally this works by:
1240 cat u-boot.bin u-boot.dtb >image.bin
1242 and in fact, U-Boot does this for you, creating a file called
1243 u-boot-dtb.bin which is useful in the common case. You can
1244 still use the individual files if you need something more
1249 If this variable is defined, it enables watchdog
1250 support for the SoC. There must be support in the SoC
1251 specific code for a watchdog. For the 8xx and 8260
1252 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1253 register. When supported for a specific SoC is
1254 available, then no further board specific code should
1255 be needed to use it.
1258 When using a watchdog circuitry external to the used
1259 SoC, then define this variable and provide board
1260 specific code for the "hw_watchdog_reset" function.
1263 CONFIG_VERSION_VARIABLE
1264 If this variable is defined, an environment variable
1265 named "ver" is created by U-Boot showing the U-Boot
1266 version as printed by the "version" command.
1267 Any change to this variable will be reverted at the
1272 When CONFIG_CMD_DATE is selected, the type of the RTC
1273 has to be selected, too. Define exactly one of the
1276 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1277 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1278 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1279 CONFIG_RTC_MC146818 - use MC146818 RTC
1280 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1281 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1282 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1283 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1284 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1285 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1286 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1287 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1288 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1291 Note that if the RTC uses I2C, then the I2C interface
1292 must also be configured. See I2C Support, below.
1295 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1297 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1298 chip-ngpio pairs that tell the PCA953X driver the number of
1299 pins supported by a particular chip.
1301 Note that if the GPIO device uses I2C, then the I2C interface
1302 must also be configured. See I2C Support, below.
1305 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1306 accesses and can checksum them or write a list of them out
1307 to memory. See the 'iotrace' command for details. This is
1308 useful for testing device drivers since it can confirm that
1309 the driver behaves the same way before and after a code
1310 change. Currently this is supported on sandbox and arm. To
1311 add support for your architecture, add '#include <iotrace.h>'
1312 to the bottom of arch/<arch>/include/asm/io.h and test.
1314 Example output from the 'iotrace stats' command is below.
1315 Note that if the trace buffer is exhausted, the checksum will
1316 still continue to operate.
1319 Start: 10000000 (buffer start address)
1320 Size: 00010000 (buffer size)
1321 Offset: 00000120 (current buffer offset)
1322 Output: 10000120 (start + offset)
1323 Count: 00000018 (number of trace records)
1324 CRC32: 9526fb66 (CRC32 of all trace records)
1326 - Timestamp Support:
1328 When CONFIG_TIMESTAMP is selected, the timestamp
1329 (date and time) of an image is printed by image
1330 commands like bootm or iminfo. This option is
1331 automatically enabled when you select CONFIG_CMD_DATE .
1333 - Partition Labels (disklabels) Supported:
1334 Zero or more of the following:
1335 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1336 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1337 Intel architecture, USB sticks, etc.
1338 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1339 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1340 bootloader. Note 2TB partition limit; see
1342 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1344 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1345 CONFIG_CMD_SCSI) you must configure support for at
1346 least one non-MTD partition type as well.
1349 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1350 board configurations files but used nowhere!
1352 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1353 be performed by calling the function
1354 ide_set_reset(int reset)
1355 which has to be defined in a board specific file
1360 Set this to enable ATAPI support.
1365 Set this to enable support for disks larger than 137GB
1366 Also look at CONFIG_SYS_64BIT_LBA.
1367 Whithout these , LBA48 support uses 32bit variables and will 'only'
1368 support disks up to 2.1TB.
1370 CONFIG_SYS_64BIT_LBA:
1371 When enabled, makes the IDE subsystem use 64bit sector addresses.
1375 At the moment only there is only support for the
1376 SYM53C8XX SCSI controller; define
1377 CONFIG_SCSI_SYM53C8XX to enable it.
1379 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1380 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1381 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1382 maximum numbers of LUNs, SCSI ID's and target
1384 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1386 The environment variable 'scsidevs' is set to the number of
1387 SCSI devices found during the last scan.
1389 - NETWORK Support (PCI):
1391 Support for Intel 8254x/8257x gigabit chips.
1394 Utility code for direct access to the SPI bus on Intel 8257x.
1395 This does not do anything useful unless you set at least one
1396 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1398 CONFIG_E1000_SPI_GENERIC
1399 Allow generic access to the SPI bus on the Intel 8257x, for
1400 example with the "sspi" command.
1403 Management command for E1000 devices. When used on devices
1404 with SPI support you can reprogram the EEPROM from U-Boot.
1406 CONFIG_E1000_FALLBACK_MAC
1407 default MAC for empty EEPROM after production.
1410 Support for Intel 82557/82559/82559ER chips.
1411 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1412 write routine for first time initialisation.
1415 Support for Digital 2114x chips.
1416 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1417 modem chip initialisation (KS8761/QS6611).
1420 Support for National dp83815 chips.
1423 Support for National dp8382[01] gigabit chips.
1425 - NETWORK Support (other):
1427 CONFIG_DRIVER_AT91EMAC
1428 Support for AT91RM9200 EMAC.
1431 Define this to use reduced MII inteface
1433 CONFIG_DRIVER_AT91EMAC_QUIET
1434 If this defined, the driver is quiet.
1435 The driver doen't show link status messages.
1437 CONFIG_CALXEDA_XGMAC
1438 Support for the Calxeda XGMAC device
1441 Support for SMSC's LAN91C96 chips.
1443 CONFIG_LAN91C96_BASE
1444 Define this to hold the physical address
1445 of the LAN91C96's I/O space
1447 CONFIG_LAN91C96_USE_32_BIT
1448 Define this to enable 32 bit addressing
1451 Support for SMSC's LAN91C111 chip
1453 CONFIG_SMC91111_BASE
1454 Define this to hold the physical address
1455 of the device (I/O space)
1457 CONFIG_SMC_USE_32_BIT
1458 Define this if data bus is 32 bits
1460 CONFIG_SMC_USE_IOFUNCS
1461 Define this to use i/o functions instead of macros
1462 (some hardware wont work with macros)
1464 CONFIG_DRIVER_TI_EMAC
1465 Support for davinci emac
1467 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1468 Define this if you have more then 3 PHYs.
1471 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1473 CONFIG_FTGMAC100_EGIGA
1474 Define this to use GE link update with gigabit PHY.
1475 Define this if FTGMAC100 is connected to gigabit PHY.
1476 If your system has 10/100 PHY only, it might not occur
1477 wrong behavior. Because PHY usually return timeout or
1478 useless data when polling gigabit status and gigabit
1479 control registers. This behavior won't affect the
1480 correctnessof 10/100 link speed update.
1483 Support for SMSC's LAN911x and LAN921x chips
1486 Define this to hold the physical address
1487 of the device (I/O space)
1489 CONFIG_SMC911X_32_BIT
1490 Define this if data bus is 32 bits
1492 CONFIG_SMC911X_16_BIT
1493 Define this if data bus is 16 bits. If your processor
1494 automatically converts one 32 bit word to two 16 bit
1495 words you may also try CONFIG_SMC911X_32_BIT.
1498 Support for Renesas on-chip Ethernet controller
1500 CONFIG_SH_ETHER_USE_PORT
1501 Define the number of ports to be used
1503 CONFIG_SH_ETHER_PHY_ADDR
1504 Define the ETH PHY's address
1506 CONFIG_SH_ETHER_CACHE_WRITEBACK
1507 If this option is set, the driver enables cache flush.
1511 Support for PWM modul on the imx6.
1515 Support TPM devices.
1518 Support for i2c bus TPM devices. Only one device
1519 per system is supported at this time.
1521 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1522 Define the the i2c bus number for the TPM device
1524 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1525 Define the TPM's address on the i2c bus
1527 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1528 Define the burst count bytes upper limit
1530 CONFIG_TPM_ATMEL_TWI
1531 Support for Atmel TWI TPM device. Requires I2C support.
1534 Support for generic parallel port TPM devices. Only one device
1535 per system is supported at this time.
1537 CONFIG_TPM_TIS_BASE_ADDRESS
1538 Base address where the generic TPM device is mapped
1539 to. Contemporary x86 systems usually map it at
1543 Add tpm monitor functions.
1544 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1545 provides monitor access to authorized functions.
1548 Define this to enable the TPM support library which provides
1549 functional interfaces to some TPM commands.
1550 Requires support for a TPM device.
1552 CONFIG_TPM_AUTH_SESSIONS
1553 Define this to enable authorized functions in the TPM library.
1554 Requires CONFIG_TPM and CONFIG_SHA1.
1557 At the moment only the UHCI host controller is
1558 supported (PIP405, MIP405, MPC5200); define
1559 CONFIG_USB_UHCI to enable it.
1560 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1561 and define CONFIG_USB_STORAGE to enable the USB
1564 Supported are USB Keyboards and USB Floppy drives
1566 MPC5200 USB requires additional defines:
1568 for 528 MHz Clock: 0x0001bbbb
1572 for differential drivers: 0x00001000
1573 for single ended drivers: 0x00005000
1574 for differential drivers on PSC3: 0x00000100
1575 for single ended drivers on PSC3: 0x00004100
1576 CONFIG_SYS_USB_EVENT_POLL
1577 May be defined to allow interrupt polling
1578 instead of using asynchronous interrupts
1580 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1581 txfilltuning field in the EHCI controller on reset.
1583 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1584 HW module registers.
1587 Define the below if you wish to use the USB console.
1588 Once firmware is rebuilt from a serial console issue the
1589 command "setenv stdin usbtty; setenv stdout usbtty" and
1590 attach your USB cable. The Unix command "dmesg" should print
1591 it has found a new device. The environment variable usbtty
1592 can be set to gserial or cdc_acm to enable your device to
1593 appear to a USB host as a Linux gserial device or a
1594 Common Device Class Abstract Control Model serial device.
1595 If you select usbtty = gserial you should be able to enumerate
1597 # modprobe usbserial vendor=0xVendorID product=0xProductID
1598 else if using cdc_acm, simply setting the environment
1599 variable usbtty to be cdc_acm should suffice. The following
1600 might be defined in YourBoardName.h
1603 Define this to build a UDC device
1606 Define this to have a tty type of device available to
1607 talk to the UDC device
1610 Define this to enable the high speed support for usb
1611 device and usbtty. If this feature is enabled, a routine
1612 int is_usbd_high_speed(void)
1613 also needs to be defined by the driver to dynamically poll
1614 whether the enumeration has succeded at high speed or full
1617 CONFIG_SYS_CONSOLE_IS_IN_ENV
1618 Define this if you want stdin, stdout &/or stderr to
1622 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1623 Derive USB clock from external clock "blah"
1624 - CONFIG_SYS_USB_EXTC_CLK 0x02
1626 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1627 Derive USB clock from brgclk
1628 - CONFIG_SYS_USB_BRG_CLK 0x04
1630 If you have a USB-IF assigned VendorID then you may wish to
1631 define your own vendor specific values either in BoardName.h
1632 or directly in usbd_vendor_info.h. If you don't define
1633 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1634 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1635 should pretend to be a Linux device to it's target host.
1637 CONFIG_USBD_MANUFACTURER
1638 Define this string as the name of your company for
1639 - CONFIG_USBD_MANUFACTURER "my company"
1641 CONFIG_USBD_PRODUCT_NAME
1642 Define this string as the name of your product
1643 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1645 CONFIG_USBD_VENDORID
1646 Define this as your assigned Vendor ID from the USB
1647 Implementors Forum. This *must* be a genuine Vendor ID
1648 to avoid polluting the USB namespace.
1649 - CONFIG_USBD_VENDORID 0xFFFF
1651 CONFIG_USBD_PRODUCTID
1652 Define this as the unique Product ID
1654 - CONFIG_USBD_PRODUCTID 0xFFFF
1656 - ULPI Layer Support:
1657 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1658 the generic ULPI layer. The generic layer accesses the ULPI PHY
1659 via the platform viewport, so you need both the genric layer and
1660 the viewport enabled. Currently only Chipidea/ARC based
1661 viewport is supported.
1662 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1663 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1664 If your ULPI phy needs a different reference clock than the
1665 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1666 the appropriate value in Hz.
1669 The MMC controller on the Intel PXA is supported. To
1670 enable this define CONFIG_MMC. The MMC can be
1671 accessed from the boot prompt by mapping the device
1672 to physical memory similar to flash. Command line is
1673 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1674 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1677 Support for Renesas on-chip MMCIF controller
1679 CONFIG_SH_MMCIF_ADDR
1680 Define the base address of MMCIF registers
1683 Define the clock frequency for MMCIF
1686 Enable the generic MMC driver
1688 CONFIG_SUPPORT_EMMC_BOOT
1689 Enable some additional features of the eMMC boot partitions.
1691 CONFIG_SUPPORT_EMMC_RPMB
1692 Enable the commands for reading, writing and programming the
1693 key for the Replay Protection Memory Block partition in eMMC.
1695 - USB Device Firmware Update (DFU) class support:
1697 This enables the USB portion of the DFU USB class
1700 This enables the command "dfu" which is used to have
1701 U-Boot create a DFU class device via USB. This command
1702 requires that the "dfu_alt_info" environment variable be
1703 set and define the alt settings to expose to the host.
1706 This enables support for exposing (e)MMC devices via DFU.
1709 This enables support for exposing NAND devices via DFU.
1712 This enables support for exposing RAM via DFU.
1713 Note: DFU spec refer to non-volatile memory usage, but
1714 allow usages beyond the scope of spec - here RAM usage,
1715 one that would help mostly the developer.
1717 CONFIG_SYS_DFU_DATA_BUF_SIZE
1718 Dfu transfer uses a buffer before writing data to the
1719 raw storage device. Make the size (in bytes) of this buffer
1720 configurable. The size of this buffer is also configurable
1721 through the "dfu_bufsiz" environment variable.
1723 CONFIG_SYS_DFU_MAX_FILE_SIZE
1724 When updating files rather than the raw storage device,
1725 we use a static buffer to copy the file into and then write
1726 the buffer once we've been given the whole file. Define
1727 this to the maximum filesize (in bytes) for the buffer.
1728 Default is 4 MiB if undefined.
1730 DFU_DEFAULT_POLL_TIMEOUT
1731 Poll timeout [ms], is the timeout a device can send to the
1732 host. The host must wait for this timeout before sending
1733 a subsequent DFU_GET_STATUS request to the device.
1735 DFU_MANIFEST_POLL_TIMEOUT
1736 Poll timeout [ms], which the device sends to the host when
1737 entering dfuMANIFEST state. Host waits this timeout, before
1738 sending again an USB request to the device.
1740 - USB Device Android Fastboot support:
1742 This enables the command "fastboot" which enables the Android
1743 fastboot mode for the platform's USB device. Fastboot is a USB
1744 protocol for downloading images, flashing and device control
1745 used on Android devices.
1746 See doc/README.android-fastboot for more information.
1748 CONFIG_ANDROID_BOOT_IMAGE
1749 This enables support for booting images which use the Android
1750 image format header.
1752 CONFIG_USB_FASTBOOT_BUF_ADDR
1753 The fastboot protocol requires a large memory buffer for
1754 downloads. Define this to the starting RAM address to use for
1757 CONFIG_USB_FASTBOOT_BUF_SIZE
1758 The fastboot protocol requires a large memory buffer for
1759 downloads. This buffer should be as large as possible for a
1760 platform. Define this to the size available RAM for fastboot.
1762 CONFIG_FASTBOOT_FLASH
1763 The fastboot protocol includes a "flash" command for writing
1764 the downloaded image to a non-volatile storage device. Define
1765 this to enable the "fastboot flash" command.
1767 CONFIG_FASTBOOT_FLASH_MMC_DEV
1768 The fastboot "flash" command requires additional information
1769 regarding the non-volatile storage device. Define this to
1770 the eMMC device that fastboot should use to store the image.
1772 - Journaling Flash filesystem support:
1773 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1774 CONFIG_JFFS2_NAND_DEV
1775 Define these for a default partition on a NAND device
1777 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1778 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1779 Define these for a default partition on a NOR device
1781 CONFIG_SYS_JFFS_CUSTOM_PART
1782 Define this to create an own partition. You have to provide a
1783 function struct part_info* jffs2_part_info(int part_num)
1785 If you define only one JFFS2 partition you may also want to
1786 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1787 to disable the command chpart. This is the default when you
1788 have not defined a custom partition
1790 - FAT(File Allocation Table) filesystem write function support:
1793 Define this to enable support for saving memory data as a
1794 file in FAT formatted partition.
1796 This will also enable the command "fatwrite" enabling the
1797 user to write files to FAT.
1799 CBFS (Coreboot Filesystem) support
1802 Define this to enable support for reading from a Coreboot
1803 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1806 - FAT(File Allocation Table) filesystem cluster size:
1807 CONFIG_FS_FAT_MAX_CLUSTSIZE
1809 Define the max cluster size for fat operations else
1810 a default value of 65536 will be defined.
1815 Define this to enable standard (PC-Style) keyboard
1819 Standard PC keyboard driver with US (is default) and
1820 GERMAN key layout (switch via environment 'keymap=de') support.
1821 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1822 for cfb_console. Supports cursor blinking.
1825 Enables a Chrome OS keyboard using the CROS_EC interface.
1826 This uses CROS_EC to communicate with a second microcontroller
1827 which provides key scans on request.
1832 Define this to enable video support (for output to
1835 CONFIG_VIDEO_CT69000
1837 Enable Chips & Technologies 69000 Video chip
1839 CONFIG_VIDEO_SMI_LYNXEM
1840 Enable Silicon Motion SMI 712/710/810 Video chip. The
1841 video output is selected via environment 'videoout'
1842 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1845 For the CT69000 and SMI_LYNXEM drivers, videomode is
1846 selected via environment 'videomode'. Two different ways
1848 - "videomode=num" 'num' is a standard LiLo mode numbers.
1849 Following standard modes are supported (* is default):
1851 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1852 -------------+---------------------------------------------
1853 8 bits | 0x301* 0x303 0x305 0x161 0x307
1854 15 bits | 0x310 0x313 0x316 0x162 0x319
1855 16 bits | 0x311 0x314 0x317 0x163 0x31A
1856 24 bits | 0x312 0x315 0x318 ? 0x31B
1857 -------------+---------------------------------------------
1858 (i.e. setenv videomode 317; saveenv; reset;)
1860 - "videomode=bootargs" all the video parameters are parsed
1861 from the bootargs. (See drivers/video/videomodes.c)
1864 CONFIG_VIDEO_SED13806
1865 Enable Epson SED13806 driver. This driver supports 8bpp
1866 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1867 or CONFIG_VIDEO_SED13806_16BPP
1870 Enable the Freescale DIU video driver. Reference boards for
1871 SOCs that have a DIU should define this macro to enable DIU
1872 support, and should also define these other macros:
1878 CONFIG_VIDEO_SW_CURSOR
1879 CONFIG_VGA_AS_SINGLE_DEVICE
1881 CONFIG_VIDEO_BMP_LOGO
1883 The DIU driver will look for the 'video-mode' environment
1884 variable, and if defined, enable the DIU as a console during
1885 boot. See the documentation file README.video for a
1886 description of this variable.
1890 Enable the VGA video / BIOS for x86. The alternative if you
1891 are using coreboot is to use the coreboot frame buffer
1898 Define this to enable a custom keyboard support.
1899 This simply calls drv_keyboard_init() which must be
1900 defined in your board-specific files.
1901 The only board using this so far is RBC823.
1903 - LCD Support: CONFIG_LCD
1905 Define this to enable LCD support (for output to LCD
1906 display); also select one of the supported displays
1907 by defining one of these:
1911 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1913 CONFIG_NEC_NL6448AC33:
1915 NEC NL6448AC33-18. Active, color, single scan.
1917 CONFIG_NEC_NL6448BC20
1919 NEC NL6448BC20-08. 6.5", 640x480.
1920 Active, color, single scan.
1922 CONFIG_NEC_NL6448BC33_54
1924 NEC NL6448BC33-54. 10.4", 640x480.
1925 Active, color, single scan.
1929 Sharp 320x240. Active, color, single scan.
1930 It isn't 16x9, and I am not sure what it is.
1932 CONFIG_SHARP_LQ64D341
1934 Sharp LQ64D341 display, 640x480.
1935 Active, color, single scan.
1939 HLD1045 display, 640x480.
1940 Active, color, single scan.
1944 Optrex CBL50840-2 NF-FW 99 22 M5
1946 Hitachi LMG6912RPFC-00T
1950 320x240. Black & white.
1952 Normally display is black on white background; define
1953 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1955 CONFIG_LCD_ALIGNMENT
1957 Normally the LCD is page-aligned (tyically 4KB). If this is
1958 defined then the LCD will be aligned to this value instead.
1959 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1960 here, since it is cheaper to change data cache settings on
1961 a per-section basis.
1963 CONFIG_CONSOLE_SCROLL_LINES
1965 When the console need to be scrolled, this is the number of
1966 lines to scroll by. It defaults to 1. Increasing this makes
1967 the console jump but can help speed up operation when scrolling
1972 Support drawing of RLE8-compressed bitmaps on the LCD.
1976 Enables an 'i2c edid' command which can read EDID
1977 information over I2C from an attached LCD display.
1979 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1981 If this option is set, the environment is checked for
1982 a variable "splashimage". If found, the usual display
1983 of logo, copyright and system information on the LCD
1984 is suppressed and the BMP image at the address
1985 specified in "splashimage" is loaded instead. The
1986 console is redirected to the "nulldev", too. This
1987 allows for a "silent" boot where a splash screen is
1988 loaded very quickly after power-on.
1990 CONFIG_SPLASHIMAGE_GUARD
1992 If this option is set, then U-Boot will prevent the environment
1993 variable "splashimage" from being set to a problematic address
1994 (see README.displaying-bmps).
1995 This option is useful for targets where, due to alignment
1996 restrictions, an improperly aligned BMP image will cause a data
1997 abort. If you think you will not have problems with unaligned
1998 accesses (for example because your toolchain prevents them)
1999 there is no need to set this option.
2001 CONFIG_SPLASH_SCREEN_ALIGN
2003 If this option is set the splash image can be freely positioned
2004 on the screen. Environment variable "splashpos" specifies the
2005 position as "x,y". If a positive number is given it is used as
2006 number of pixel from left/top. If a negative number is given it
2007 is used as number of pixel from right/bottom. You can also
2008 specify 'm' for centering the image.
2011 setenv splashpos m,m
2012 => image at center of screen
2014 setenv splashpos 30,20
2015 => image at x = 30 and y = 20
2017 setenv splashpos -10,m
2018 => vertically centered image
2019 at x = dspWidth - bmpWidth - 9
2021 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2023 If this option is set, additionally to standard BMP
2024 images, gzipped BMP images can be displayed via the
2025 splashscreen support or the bmp command.
2027 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2029 If this option is set, 8-bit RLE compressed BMP images
2030 can be displayed via the splashscreen support or the
2033 - Do compresssing for memory range:
2036 If this option is set, it would use zlib deflate method
2037 to compress the specified memory at its best effort.
2039 - Compression support:
2042 Enabled by default to support gzip compressed images.
2046 If this option is set, support for bzip2 compressed
2047 images is included. If not, only uncompressed and gzip
2048 compressed images are supported.
2050 NOTE: the bzip2 algorithm requires a lot of RAM, so
2051 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2056 If this option is set, support for lzma compressed
2059 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2060 requires an amount of dynamic memory that is given by the
2063 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2065 Where lc and lp stand for, respectively, Literal context bits
2066 and Literal pos bits.
2068 This value is upper-bounded by 14MB in the worst case. Anyway,
2069 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2070 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2071 a very small buffer.
2073 Use the lzmainfo tool to determinate the lc and lp values and
2074 then calculate the amount of needed dynamic memory (ensuring
2075 the appropriate CONFIG_SYS_MALLOC_LEN value).
2079 If this option is set, support for LZO compressed images
2085 The address of PHY on MII bus.
2087 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2089 The clock frequency of the MII bus
2093 If this option is set, support for speed/duplex
2094 detection of gigabit PHY is included.
2096 CONFIG_PHY_RESET_DELAY
2098 Some PHY like Intel LXT971A need extra delay after
2099 reset before any MII register access is possible.
2100 For such PHY, set this option to the usec delay
2101 required. (minimum 300usec for LXT971A)
2103 CONFIG_PHY_CMD_DELAY (ppc4xx)
2105 Some PHY like Intel LXT971A need extra delay after
2106 command issued before MII status register can be read
2116 Define a default value for Ethernet address to use
2117 for the respective Ethernet interface, in case this
2118 is not determined automatically.
2123 Define a default value for the IP address to use for
2124 the default Ethernet interface, in case this is not
2125 determined through e.g. bootp.
2126 (Environment variable "ipaddr")
2128 - Server IP address:
2131 Defines a default value for the IP address of a TFTP
2132 server to contact when using the "tftboot" command.
2133 (Environment variable "serverip")
2135 CONFIG_KEEP_SERVERADDR
2137 Keeps the server's MAC address, in the env 'serveraddr'
2138 for passing to bootargs (like Linux's netconsole option)
2140 - Gateway IP address:
2143 Defines a default value for the IP address of the
2144 default router where packets to other networks are
2146 (Environment variable "gatewayip")
2151 Defines a default value for the subnet mask (or
2152 routing prefix) which is used to determine if an IP
2153 address belongs to the local subnet or needs to be
2154 forwarded through a router.
2155 (Environment variable "netmask")
2157 - Multicast TFTP Mode:
2160 Defines whether you want to support multicast TFTP as per
2161 rfc-2090; for example to work with atftp. Lets lots of targets
2162 tftp down the same boot image concurrently. Note: the Ethernet
2163 driver in use must provide a function: mcast() to join/leave a
2166 - BOOTP Recovery Mode:
2167 CONFIG_BOOTP_RANDOM_DELAY
2169 If you have many targets in a network that try to
2170 boot using BOOTP, you may want to avoid that all
2171 systems send out BOOTP requests at precisely the same
2172 moment (which would happen for instance at recovery
2173 from a power failure, when all systems will try to
2174 boot, thus flooding the BOOTP server. Defining
2175 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2176 inserted before sending out BOOTP requests. The
2177 following delays are inserted then:
2179 1st BOOTP request: delay 0 ... 1 sec
2180 2nd BOOTP request: delay 0 ... 2 sec
2181 3rd BOOTP request: delay 0 ... 4 sec
2183 BOOTP requests: delay 0 ... 8 sec
2185 CONFIG_BOOTP_ID_CACHE_SIZE
2187 BOOTP packets are uniquely identified using a 32-bit ID. The
2188 server will copy the ID from client requests to responses and
2189 U-Boot will use this to determine if it is the destination of
2190 an incoming response. Some servers will check that addresses
2191 aren't in use before handing them out (usually using an ARP
2192 ping) and therefore take up to a few hundred milliseconds to
2193 respond. Network congestion may also influence the time it
2194 takes for a response to make it back to the client. If that
2195 time is too long, U-Boot will retransmit requests. In order
2196 to allow earlier responses to still be accepted after these
2197 retransmissions, U-Boot's BOOTP client keeps a small cache of
2198 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2199 cache. The default is to keep IDs for up to four outstanding
2200 requests. Increasing this will allow U-Boot to accept offers
2201 from a BOOTP client in networks with unusually high latency.
2203 - DHCP Advanced Options:
2204 You can fine tune the DHCP functionality by defining
2205 CONFIG_BOOTP_* symbols:
2207 CONFIG_BOOTP_SUBNETMASK
2208 CONFIG_BOOTP_GATEWAY
2209 CONFIG_BOOTP_HOSTNAME
2210 CONFIG_BOOTP_NISDOMAIN
2211 CONFIG_BOOTP_BOOTPATH
2212 CONFIG_BOOTP_BOOTFILESIZE
2215 CONFIG_BOOTP_SEND_HOSTNAME
2216 CONFIG_BOOTP_NTPSERVER
2217 CONFIG_BOOTP_TIMEOFFSET
2218 CONFIG_BOOTP_VENDOREX
2219 CONFIG_BOOTP_MAY_FAIL
2221 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2222 environment variable, not the BOOTP server.
2224 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2225 after the configured retry count, the call will fail
2226 instead of starting over. This can be used to fail over
2227 to Link-local IP address configuration if the DHCP server
2230 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2231 serverip from a DHCP server, it is possible that more
2232 than one DNS serverip is offered to the client.
2233 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2234 serverip will be stored in the additional environment
2235 variable "dnsip2". The first DNS serverip is always
2236 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2239 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2240 to do a dynamic update of a DNS server. To do this, they
2241 need the hostname of the DHCP requester.
2242 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2243 of the "hostname" environment variable is passed as
2244 option 12 to the DHCP server.
2246 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2248 A 32bit value in microseconds for a delay between
2249 receiving a "DHCP Offer" and sending the "DHCP Request".
2250 This fixes a problem with certain DHCP servers that don't
2251 respond 100% of the time to a "DHCP request". E.g. On an
2252 AT91RM9200 processor running at 180MHz, this delay needed
2253 to be *at least* 15,000 usec before a Windows Server 2003
2254 DHCP server would reply 100% of the time. I recommend at
2255 least 50,000 usec to be safe. The alternative is to hope
2256 that one of the retries will be successful but note that
2257 the DHCP timeout and retry process takes a longer than
2260 - Link-local IP address negotiation:
2261 Negotiate with other link-local clients on the local network
2262 for an address that doesn't require explicit configuration.
2263 This is especially useful if a DHCP server cannot be guaranteed
2264 to exist in all environments that the device must operate.
2266 See doc/README.link-local for more information.
2269 CONFIG_CDP_DEVICE_ID
2271 The device id used in CDP trigger frames.
2273 CONFIG_CDP_DEVICE_ID_PREFIX
2275 A two character string which is prefixed to the MAC address
2280 A printf format string which contains the ascii name of
2281 the port. Normally is set to "eth%d" which sets
2282 eth0 for the first Ethernet, eth1 for the second etc.
2284 CONFIG_CDP_CAPABILITIES
2286 A 32bit integer which indicates the device capabilities;
2287 0x00000010 for a normal host which does not forwards.
2291 An ascii string containing the version of the software.
2295 An ascii string containing the name of the platform.
2299 A 32bit integer sent on the trigger.
2301 CONFIG_CDP_POWER_CONSUMPTION
2303 A 16bit integer containing the power consumption of the
2304 device in .1 of milliwatts.
2306 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2308 A byte containing the id of the VLAN.
2310 - Status LED: CONFIG_STATUS_LED
2312 Several configurations allow to display the current
2313 status using a LED. For instance, the LED will blink
2314 fast while running U-Boot code, stop blinking as
2315 soon as a reply to a BOOTP request was received, and
2316 start blinking slow once the Linux kernel is running
2317 (supported by a status LED driver in the Linux
2318 kernel). Defining CONFIG_STATUS_LED enables this
2324 The status LED can be connected to a GPIO pin.
2325 In such cases, the gpio_led driver can be used as a
2326 status LED backend implementation. Define CONFIG_GPIO_LED
2327 to include the gpio_led driver in the U-Boot binary.
2329 CONFIG_GPIO_LED_INVERTED_TABLE
2330 Some GPIO connected LEDs may have inverted polarity in which
2331 case the GPIO high value corresponds to LED off state and
2332 GPIO low value corresponds to LED on state.
2333 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2334 with a list of GPIO LEDs that have inverted polarity.
2336 - CAN Support: CONFIG_CAN_DRIVER
2338 Defining CONFIG_CAN_DRIVER enables CAN driver support
2339 on those systems that support this (optional)
2340 feature, like the TQM8xxL modules.
2342 - I2C Support: CONFIG_SYS_I2C
2344 This enable the NEW i2c subsystem, and will allow you to use
2345 i2c commands at the u-boot command line (as long as you set
2346 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2347 based realtime clock chips or other i2c devices. See
2348 common/cmd_i2c.c for a description of the command line
2351 ported i2c driver to the new framework:
2352 - drivers/i2c/soft_i2c.c:
2353 - activate first bus with CONFIG_SYS_I2C_SOFT define
2354 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2355 for defining speed and slave address
2356 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2357 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2358 for defining speed and slave address
2359 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2360 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2361 for defining speed and slave address
2362 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2363 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2364 for defining speed and slave address
2366 - drivers/i2c/fsl_i2c.c:
2367 - activate i2c driver with CONFIG_SYS_I2C_FSL
2368 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2369 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2370 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2372 - If your board supports a second fsl i2c bus, define
2373 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2374 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2375 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2378 - drivers/i2c/tegra_i2c.c:
2379 - activate this driver with CONFIG_SYS_I2C_TEGRA
2380 - This driver adds 4 i2c buses with a fix speed from
2381 100000 and the slave addr 0!
2383 - drivers/i2c/ppc4xx_i2c.c
2384 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2385 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2386 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2388 - drivers/i2c/i2c_mxc.c
2389 - activate this driver with CONFIG_SYS_I2C_MXC
2390 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2391 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2392 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2393 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2394 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2395 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2396 If thoses defines are not set, default value is 100000
2397 for speed, and 0 for slave.
2399 - drivers/i2c/rcar_i2c.c:
2400 - activate this driver with CONFIG_SYS_I2C_RCAR
2401 - This driver adds 4 i2c buses
2403 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2404 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2405 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2406 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2407 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2408 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2409 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2410 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2411 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2413 - drivers/i2c/sh_i2c.c:
2414 - activate this driver with CONFIG_SYS_I2C_SH
2415 - This driver adds from 2 to 5 i2c buses
2417 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2418 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2419 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2420 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2421 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2422 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2423 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2424 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2425 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2426 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2427 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2428 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2429 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2431 - drivers/i2c/omap24xx_i2c.c
2432 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2433 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2434 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2435 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2436 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2437 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2438 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2439 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2440 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2441 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2442 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2444 - drivers/i2c/zynq_i2c.c
2445 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2446 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2447 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2449 - drivers/i2c/s3c24x0_i2c.c:
2450 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2451 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2452 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2453 with a fix speed from 100000 and the slave addr 0!
2455 - drivers/i2c/ihs_i2c.c
2456 - activate this driver with CONFIG_SYS_I2C_IHS
2457 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2458 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2459 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2460 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2461 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2462 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2463 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2464 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2465 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2466 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2467 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2468 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2472 CONFIG_SYS_NUM_I2C_BUSES
2473 Hold the number of i2c busses you want to use. If you
2474 don't use/have i2c muxes on your i2c bus, this
2475 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2478 CONFIG_SYS_I2C_DIRECT_BUS
2479 define this, if you don't use i2c muxes on your hardware.
2480 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2483 CONFIG_SYS_I2C_MAX_HOPS
2484 define how many muxes are maximal consecutively connected
2485 on one i2c bus. If you not use i2c muxes, omit this
2488 CONFIG_SYS_I2C_BUSES
2489 hold a list of busses you want to use, only used if
2490 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2491 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2492 CONFIG_SYS_NUM_I2C_BUSES = 9:
2494 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2495 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2496 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2497 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2498 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2499 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2500 {1, {I2C_NULL_HOP}}, \
2501 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2502 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2506 bus 0 on adapter 0 without a mux
2507 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2508 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2509 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2510 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2511 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2512 bus 6 on adapter 1 without a mux
2513 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2514 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2516 If you do not have i2c muxes on your board, omit this define.
2518 - Legacy I2C Support: CONFIG_HARD_I2C
2520 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2521 provides the following compelling advantages:
2523 - more than one i2c adapter is usable
2524 - approved multibus support
2525 - better i2c mux support
2527 ** Please consider updating your I2C driver now. **
2529 These enable legacy I2C serial bus commands. Defining
2530 CONFIG_HARD_I2C will include the appropriate I2C driver
2531 for the selected CPU.
2533 This will allow you to use i2c commands at the u-boot
2534 command line (as long as you set CONFIG_CMD_I2C in
2535 CONFIG_COMMANDS) and communicate with i2c based realtime
2536 clock chips. See common/cmd_i2c.c for a description of the
2537 command line interface.
2539 CONFIG_HARD_I2C selects a hardware I2C controller.
2541 There are several other quantities that must also be
2542 defined when you define CONFIG_HARD_I2C.
2544 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2545 to be the frequency (in Hz) at which you wish your i2c bus
2546 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2547 the CPU's i2c node address).
2549 Now, the u-boot i2c code for the mpc8xx
2550 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2551 and so its address should therefore be cleared to 0 (See,
2552 eg, MPC823e User's Manual p.16-473). So, set
2553 CONFIG_SYS_I2C_SLAVE to 0.
2555 CONFIG_SYS_I2C_INIT_MPC5XXX
2557 When a board is reset during an i2c bus transfer
2558 chips might think that the current transfer is still
2559 in progress. Reset the slave devices by sending start
2560 commands until the slave device responds.
2562 That's all that's required for CONFIG_HARD_I2C.
2564 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2565 then the following macros need to be defined (examples are
2566 from include/configs/lwmon.h):
2570 (Optional). Any commands necessary to enable the I2C
2571 controller or configure ports.
2573 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2577 (Only for MPC8260 CPU). The I/O port to use (the code
2578 assumes both bits are on the same port). Valid values
2579 are 0..3 for ports A..D.
2583 The code necessary to make the I2C data line active
2584 (driven). If the data line is open collector, this
2587 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2591 The code necessary to make the I2C data line tri-stated
2592 (inactive). If the data line is open collector, this
2595 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2599 Code that returns true if the I2C data line is high,
2602 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2606 If <bit> is true, sets the I2C data line high. If it
2607 is false, it clears it (low).
2609 eg: #define I2C_SDA(bit) \
2610 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2611 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2615 If <bit> is true, sets the I2C clock line high. If it
2616 is false, it clears it (low).
2618 eg: #define I2C_SCL(bit) \
2619 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2620 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2624 This delay is invoked four times per clock cycle so this
2625 controls the rate of data transfer. The data rate thus
2626 is 1 / (I2C_DELAY * 4). Often defined to be something
2629 #define I2C_DELAY udelay(2)
2631 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2633 If your arch supports the generic GPIO framework (asm/gpio.h),
2634 then you may alternatively define the two GPIOs that are to be
2635 used as SCL / SDA. Any of the previous I2C_xxx macros will
2636 have GPIO-based defaults assigned to them as appropriate.
2638 You should define these to the GPIO value as given directly to
2639 the generic GPIO functions.
2641 CONFIG_SYS_I2C_INIT_BOARD
2643 When a board is reset during an i2c bus transfer
2644 chips might think that the current transfer is still
2645 in progress. On some boards it is possible to access
2646 the i2c SCLK line directly, either by using the
2647 processor pin as a GPIO or by having a second pin
2648 connected to the bus. If this option is defined a
2649 custom i2c_init_board() routine in boards/xxx/board.c
2650 is run early in the boot sequence.
2652 CONFIG_SYS_I2C_BOARD_LATE_INIT
2654 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2655 defined a custom i2c_board_late_init() routine in
2656 boards/xxx/board.c is run AFTER the operations in i2c_init()
2657 is completed. This callpoint can be used to unreset i2c bus
2658 using CPU i2c controller register accesses for CPUs whose i2c
2659 controller provide such a method. It is called at the end of
2660 i2c_init() to allow i2c_init operations to setup the i2c bus
2661 controller on the CPU (e.g. setting bus speed & slave address).
2663 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2665 This option enables configuration of bi_iic_fast[] flags
2666 in u-boot bd_info structure based on u-boot environment
2667 variable "i2cfast". (see also i2cfast)
2669 CONFIG_I2C_MULTI_BUS
2671 This option allows the use of multiple I2C buses, each of which
2672 must have a controller. At any point in time, only one bus is
2673 active. To switch to a different bus, use the 'i2c dev' command.
2674 Note that bus numbering is zero-based.
2676 CONFIG_SYS_I2C_NOPROBES
2678 This option specifies a list of I2C devices that will be skipped
2679 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2680 is set, specify a list of bus-device pairs. Otherwise, specify
2681 a 1D array of device addresses
2684 #undef CONFIG_I2C_MULTI_BUS
2685 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2687 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2689 #define CONFIG_I2C_MULTI_BUS
2690 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2692 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2694 CONFIG_SYS_SPD_BUS_NUM
2696 If defined, then this indicates the I2C bus number for DDR SPD.
2697 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2699 CONFIG_SYS_RTC_BUS_NUM
2701 If defined, then this indicates the I2C bus number for the RTC.
2702 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2704 CONFIG_SYS_DTT_BUS_NUM
2706 If defined, then this indicates the I2C bus number for the DTT.
2707 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2709 CONFIG_SYS_I2C_DTT_ADDR:
2711 If defined, specifies the I2C address of the DTT device.
2712 If not defined, then U-Boot uses predefined value for
2713 specified DTT device.
2715 CONFIG_SOFT_I2C_READ_REPEATED_START
2717 defining this will force the i2c_read() function in
2718 the soft_i2c driver to perform an I2C repeated start
2719 between writing the address pointer and reading the
2720 data. If this define is omitted the default behaviour
2721 of doing a stop-start sequence will be used. Most I2C
2722 devices can use either method, but some require one or
2725 - SPI Support: CONFIG_SPI
2727 Enables SPI driver (so far only tested with
2728 SPI EEPROM, also an instance works with Crystal A/D and
2729 D/As on the SACSng board)
2733 Enables the driver for SPI controller on SuperH. Currently
2734 only SH7757 is supported.
2738 Enables extended (16-bit) SPI EEPROM addressing.
2739 (symmetrical to CONFIG_I2C_X)
2743 Enables a software (bit-bang) SPI driver rather than
2744 using hardware support. This is a general purpose
2745 driver that only requires three general I/O port pins
2746 (two outputs, one input) to function. If this is
2747 defined, the board configuration must define several
2748 SPI configuration items (port pins to use, etc). For
2749 an example, see include/configs/sacsng.h.
2753 Enables a hardware SPI driver for general-purpose reads
2754 and writes. As with CONFIG_SOFT_SPI, the board configuration
2755 must define a list of chip-select function pointers.
2756 Currently supported on some MPC8xxx processors. For an
2757 example, see include/configs/mpc8349emds.h.
2761 Enables the driver for the SPI controllers on i.MX and MXC
2762 SoCs. Currently i.MX31/35/51 are supported.
2764 CONFIG_SYS_SPI_MXC_WAIT
2765 Timeout for waiting until spi transfer completed.
2766 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2768 - FPGA Support: CONFIG_FPGA
2770 Enables FPGA subsystem.
2772 CONFIG_FPGA_<vendor>
2774 Enables support for specific chip vendors.
2777 CONFIG_FPGA_<family>
2779 Enables support for FPGA family.
2780 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2784 Specify the number of FPGA devices to support.
2786 CONFIG_CMD_FPGA_LOADMK
2788 Enable support for fpga loadmk command
2790 CONFIG_CMD_FPGA_LOADP
2792 Enable support for fpga loadp command - load partial bitstream
2794 CONFIG_CMD_FPGA_LOADBP
2796 Enable support for fpga loadbp command - load partial bitstream
2799 CONFIG_SYS_FPGA_PROG_FEEDBACK
2801 Enable printing of hash marks during FPGA configuration.
2803 CONFIG_SYS_FPGA_CHECK_BUSY
2805 Enable checks on FPGA configuration interface busy
2806 status by the configuration function. This option
2807 will require a board or device specific function to
2812 If defined, a function that provides delays in the FPGA
2813 configuration driver.
2815 CONFIG_SYS_FPGA_CHECK_CTRLC
2816 Allow Control-C to interrupt FPGA configuration
2818 CONFIG_SYS_FPGA_CHECK_ERROR
2820 Check for configuration errors during FPGA bitfile
2821 loading. For example, abort during Virtex II
2822 configuration if the INIT_B line goes low (which
2823 indicated a CRC error).
2825 CONFIG_SYS_FPGA_WAIT_INIT
2827 Maximum time to wait for the INIT_B line to deassert
2828 after PROB_B has been deasserted during a Virtex II
2829 FPGA configuration sequence. The default time is 500
2832 CONFIG_SYS_FPGA_WAIT_BUSY
2834 Maximum time to wait for BUSY to deassert during
2835 Virtex II FPGA configuration. The default is 5 ms.
2837 CONFIG_SYS_FPGA_WAIT_CONFIG
2839 Time to wait after FPGA configuration. The default is
2842 - Configuration Management:
2845 Some SoCs need special image types (e.g. U-Boot binary
2846 with a special header) as build targets. By defining
2847 CONFIG_BUILD_TARGET in the SoC / board header, this
2848 special image will be automatically built upon calling
2853 If defined, this string will be added to the U-Boot
2854 version information (U_BOOT_VERSION)
2856 - Vendor Parameter Protection:
2858 U-Boot considers the values of the environment
2859 variables "serial#" (Board Serial Number) and
2860 "ethaddr" (Ethernet Address) to be parameters that
2861 are set once by the board vendor / manufacturer, and
2862 protects these variables from casual modification by
2863 the user. Once set, these variables are read-only,
2864 and write or delete attempts are rejected. You can
2865 change this behaviour:
2867 If CONFIG_ENV_OVERWRITE is #defined in your config
2868 file, the write protection for vendor parameters is
2869 completely disabled. Anybody can change or delete
2872 Alternatively, if you #define _both_ CONFIG_ETHADDR
2873 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2874 Ethernet address is installed in the environment,
2875 which can be changed exactly ONCE by the user. [The
2876 serial# is unaffected by this, i. e. it remains
2879 The same can be accomplished in a more flexible way
2880 for any variable by configuring the type of access
2881 to allow for those variables in the ".flags" variable
2882 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2887 Define this variable to enable the reservation of
2888 "protected RAM", i. e. RAM which is not overwritten
2889 by U-Boot. Define CONFIG_PRAM to hold the number of
2890 kB you want to reserve for pRAM. You can overwrite
2891 this default value by defining an environment
2892 variable "pram" to the number of kB you want to
2893 reserve. Note that the board info structure will
2894 still show the full amount of RAM. If pRAM is
2895 reserved, a new environment variable "mem" will
2896 automatically be defined to hold the amount of
2897 remaining RAM in a form that can be passed as boot
2898 argument to Linux, for instance like that:
2900 setenv bootargs ... mem=\${mem}
2903 This way you can tell Linux not to use this memory,
2904 either, which results in a memory region that will
2905 not be affected by reboots.
2907 *WARNING* If your board configuration uses automatic
2908 detection of the RAM size, you must make sure that
2909 this memory test is non-destructive. So far, the
2910 following board configurations are known to be
2913 IVMS8, IVML24, SPD8xx, TQM8xxL,
2914 HERMES, IP860, RPXlite, LWMON,
2917 - Access to physical memory region (> 4GB)
2918 Some basic support is provided for operations on memory not
2919 normally accessible to U-Boot - e.g. some architectures
2920 support access to more than 4GB of memory on 32-bit
2921 machines using physical address extension or similar.
2922 Define CONFIG_PHYSMEM to access this basic support, which
2923 currently only supports clearing the memory.
2928 Define this variable to stop the system in case of a
2929 fatal error, so that you have to reset it manually.
2930 This is probably NOT a good idea for an embedded
2931 system where you want the system to reboot
2932 automatically as fast as possible, but it may be
2933 useful during development since you can try to debug
2934 the conditions that lead to the situation.
2936 CONFIG_NET_RETRY_COUNT
2938 This variable defines the number of retries for
2939 network operations like ARP, RARP, TFTP, or BOOTP
2940 before giving up the operation. If not defined, a
2941 default value of 5 is used.
2945 Timeout waiting for an ARP reply in milliseconds.
2949 Timeout in milliseconds used in NFS protocol.
2950 If you encounter "ERROR: Cannot umount" in nfs command,
2951 try longer timeout such as
2952 #define CONFIG_NFS_TIMEOUT 10000UL
2954 - Command Interpreter:
2955 CONFIG_AUTO_COMPLETE
2957 Enable auto completion of commands using TAB.
2959 CONFIG_SYS_PROMPT_HUSH_PS2
2961 This defines the secondary prompt string, which is
2962 printed when the command interpreter needs more input
2963 to complete a command. Usually "> ".
2967 In the current implementation, the local variables
2968 space and global environment variables space are
2969 separated. Local variables are those you define by
2970 simply typing `name=value'. To access a local
2971 variable later on, you have write `$name' or
2972 `${name}'; to execute the contents of a variable
2973 directly type `$name' at the command prompt.
2975 Global environment variables are those you use
2976 setenv/printenv to work with. To run a command stored
2977 in such a variable, you need to use the run command,
2978 and you must not use the '$' sign to access them.
2980 To store commands and special characters in a
2981 variable, please use double quotation marks
2982 surrounding the whole text of the variable, instead
2983 of the backslashes before semicolons and special
2986 - Commandline Editing and History:
2987 CONFIG_CMDLINE_EDITING
2989 Enable editing and History functions for interactive
2990 commandline input operations
2992 - Default Environment:
2993 CONFIG_EXTRA_ENV_SETTINGS
2995 Define this to contain any number of null terminated
2996 strings (variable = value pairs) that will be part of
2997 the default environment compiled into the boot image.
2999 For example, place something like this in your
3000 board's config file:
3002 #define CONFIG_EXTRA_ENV_SETTINGS \
3006 Warning: This method is based on knowledge about the
3007 internal format how the environment is stored by the
3008 U-Boot code. This is NOT an official, exported
3009 interface! Although it is unlikely that this format
3010 will change soon, there is no guarantee either.
3011 You better know what you are doing here.
3013 Note: overly (ab)use of the default environment is
3014 discouraged. Make sure to check other ways to preset
3015 the environment like the "source" command or the
3018 CONFIG_ENV_VARS_UBOOT_CONFIG
3020 Define this in order to add variables describing the
3021 U-Boot build configuration to the default environment.
3022 These will be named arch, cpu, board, vendor, and soc.
3024 Enabling this option will cause the following to be defined:
3032 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3034 Define this in order to add variables describing certain
3035 run-time determined information about the hardware to the
3036 environment. These will be named board_name, board_rev.
3038 CONFIG_DELAY_ENVIRONMENT
3040 Normally the environment is loaded when the board is
3041 intialised so that it is available to U-Boot. This inhibits
3042 that so that the environment is not available until
3043 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3044 this is instead controlled by the value of
3045 /config/load-environment.
3047 - DataFlash Support:
3048 CONFIG_HAS_DATAFLASH
3050 Defining this option enables DataFlash features and
3051 allows to read/write in Dataflash via the standard
3054 - Serial Flash support
3057 Defining this option enables SPI flash commands
3058 'sf probe/read/write/erase/update'.
3060 Usage requires an initial 'probe' to define the serial
3061 flash parameters, followed by read/write/erase/update
3064 The following defaults may be provided by the platform
3065 to handle the common case when only a single serial
3066 flash is present on the system.
3068 CONFIG_SF_DEFAULT_BUS Bus identifier
3069 CONFIG_SF_DEFAULT_CS Chip-select
3070 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3071 CONFIG_SF_DEFAULT_SPEED in Hz
3075 Define this option to include a destructive SPI flash
3078 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3080 Define this option to use the Bank addr/Extended addr
3081 support on SPI flashes which has size > 16Mbytes.
3083 CONFIG_SF_DUAL_FLASH Dual flash memories
3085 Define this option to use dual flash support where two flash
3086 memories can be connected with a given cs line.
3087 currently Xilinx Zynq qspi support these type of connections.
3089 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3090 enable the W#/Vpp signal to disable writing to the status
3091 register on ST MICRON flashes like the N25Q128.
3092 The status register write enable/disable bit, combined with
3093 the W#/VPP signal provides hardware data protection for the
3094 device as follows: When the enable/disable bit is set to 1,
3095 and the W#/VPP signal is driven LOW, the status register
3096 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3097 operation will not execute. The only way to exit this
3098 hardware-protected mode is to drive W#/VPP HIGH.
3100 - SystemACE Support:
3103 Adding this option adds support for Xilinx SystemACE
3104 chips attached via some sort of local bus. The address
3105 of the chip must also be defined in the
3106 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3108 #define CONFIG_SYSTEMACE
3109 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3111 When SystemACE support is added, the "ace" device type
3112 becomes available to the fat commands, i.e. fatls.
3114 - TFTP Fixed UDP Port:
3117 If this is defined, the environment variable tftpsrcp
3118 is used to supply the TFTP UDP source port value.
3119 If tftpsrcp isn't defined, the normal pseudo-random port
3120 number generator is used.
3122 Also, the environment variable tftpdstp is used to supply
3123 the TFTP UDP destination port value. If tftpdstp isn't
3124 defined, the normal port 69 is used.
3126 The purpose for tftpsrcp is to allow a TFTP server to
3127 blindly start the TFTP transfer using the pre-configured
3128 target IP address and UDP port. This has the effect of
3129 "punching through" the (Windows XP) firewall, allowing
3130 the remainder of the TFTP transfer to proceed normally.
3131 A better solution is to properly configure the firewall,
3132 but sometimes that is not allowed.
3137 This enables a generic 'hash' command which can produce
3138 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3142 Enable the hash verify command (hash -v). This adds to code
3145 CONFIG_SHA1 - support SHA1 hashing
3146 CONFIG_SHA256 - support SHA256 hashing
3148 Note: There is also a sha1sum command, which should perhaps
3149 be deprecated in favour of 'hash sha1'.
3151 - Freescale i.MX specific commands:
3152 CONFIG_CMD_HDMIDETECT
3153 This enables 'hdmidet' command which returns true if an
3154 HDMI monitor is detected. This command is i.MX 6 specific.
3157 This enables the 'bmode' (bootmode) command for forcing
3158 a boot from specific media.
3160 This is useful for forcing the ROM's usb downloader to
3161 activate upon a watchdog reset which is nice when iterating
3162 on U-Boot. Using the reset button or running bmode normal
3163 will set it back to normal. This command currently
3164 supports i.MX53 and i.MX6.
3169 This enables the RSA algorithm used for FIT image verification
3170 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3172 The signing part is build into mkimage regardless of this
3175 - bootcount support:
3176 CONFIG_BOOTCOUNT_LIMIT
3178 This enables the bootcounter support, see:
3179 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3182 enable special bootcounter support on at91sam9xe based boards.
3184 enable special bootcounter support on blackfin based boards.
3186 enable special bootcounter support on da850 based boards.
3187 CONFIG_BOOTCOUNT_RAM
3188 enable support for the bootcounter in RAM
3189 CONFIG_BOOTCOUNT_I2C
3190 enable support for the bootcounter on an i2c (like RTC) device.
3191 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3192 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3194 CONFIG_BOOTCOUNT_ALEN = address len
3196 - Show boot progress:
3197 CONFIG_SHOW_BOOT_PROGRESS
3199 Defining this option allows to add some board-
3200 specific code (calling a user-provided function
3201 "show_boot_progress(int)") that enables you to show
3202 the system's boot progress on some display (for
3203 example, some LED's) on your board. At the moment,
3204 the following checkpoints are implemented:
3206 - Detailed boot stage timing
3208 Define this option to get detailed timing of each stage
3209 of the boot process.
3211 CONFIG_BOOTSTAGE_USER_COUNT
3212 This is the number of available user bootstage records.
3213 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3214 a new ID will be allocated from this stash. If you exceed
3215 the limit, recording will stop.
3217 CONFIG_BOOTSTAGE_REPORT
3218 Define this to print a report before boot, similar to this:
3220 Timer summary in microseconds:
3223 3,575,678 3,575,678 board_init_f start
3224 3,575,695 17 arch_cpu_init A9
3225 3,575,777 82 arch_cpu_init done
3226 3,659,598 83,821 board_init_r start
3227 3,910,375 250,777 main_loop
3228 29,916,167 26,005,792 bootm_start
3229 30,361,327 445,160 start_kernel
3231 CONFIG_CMD_BOOTSTAGE
3232 Add a 'bootstage' command which supports printing a report
3233 and un/stashing of bootstage data.
3235 CONFIG_BOOTSTAGE_FDT
3236 Stash the bootstage information in the FDT. A root 'bootstage'
3237 node is created with each bootstage id as a child. Each child
3238 has a 'name' property and either 'mark' containing the
3239 mark time in microsecond, or 'accum' containing the
3240 accumulated time for that bootstage id in microseconds.
3245 name = "board_init_f";
3254 Code in the Linux kernel can find this in /proc/devicetree.
3256 Legacy uImage format:
3259 1 common/cmd_bootm.c before attempting to boot an image
3260 -1 common/cmd_bootm.c Image header has bad magic number
3261 2 common/cmd_bootm.c Image header has correct magic number
3262 -2 common/cmd_bootm.c Image header has bad checksum
3263 3 common/cmd_bootm.c Image header has correct checksum
3264 -3 common/cmd_bootm.c Image data has bad checksum
3265 4 common/cmd_bootm.c Image data has correct checksum
3266 -4 common/cmd_bootm.c Image is for unsupported architecture
3267 5 common/cmd_bootm.c Architecture check OK
3268 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3269 6 common/cmd_bootm.c Image Type check OK
3270 -6 common/cmd_bootm.c gunzip uncompression error
3271 -7 common/cmd_bootm.c Unimplemented compression type
3272 7 common/cmd_bootm.c Uncompression OK
3273 8 common/cmd_bootm.c No uncompress/copy overwrite error
3274 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3276 9 common/image.c Start initial ramdisk verification
3277 -10 common/image.c Ramdisk header has bad magic number
3278 -11 common/image.c Ramdisk header has bad checksum
3279 10 common/image.c Ramdisk header is OK
3280 -12 common/image.c Ramdisk data has bad checksum
3281 11 common/image.c Ramdisk data has correct checksum
3282 12 common/image.c Ramdisk verification complete, start loading
3283 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3284 13 common/image.c Start multifile image verification
3285 14 common/image.c No initial ramdisk, no multifile, continue.
3287 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3289 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3290 -31 post/post.c POST test failed, detected by post_output_backlog()
3291 -32 post/post.c POST test failed, detected by post_run_single()
3293 34 common/cmd_doc.c before loading a Image from a DOC device
3294 -35 common/cmd_doc.c Bad usage of "doc" command
3295 35 common/cmd_doc.c correct usage of "doc" command
3296 -36 common/cmd_doc.c No boot device
3297 36 common/cmd_doc.c correct boot device
3298 -37 common/cmd_doc.c Unknown Chip ID on boot device
3299 37 common/cmd_doc.c correct chip ID found, device available
3300 -38 common/cmd_doc.c Read Error on boot device
3301 38 common/cmd_doc.c reading Image header from DOC device OK
3302 -39 common/cmd_doc.c Image header has bad magic number
3303 39 common/cmd_doc.c Image header has correct magic number
3304 -40 common/cmd_doc.c Error reading Image from DOC device
3305 40 common/cmd_doc.c Image header has correct magic number
3306 41 common/cmd_ide.c before loading a Image from a IDE device
3307 -42 common/cmd_ide.c Bad usage of "ide" command
3308 42 common/cmd_ide.c correct usage of "ide" command
3309 -43 common/cmd_ide.c No boot device
3310 43 common/cmd_ide.c boot device found
3311 -44 common/cmd_ide.c Device not available
3312 44 common/cmd_ide.c Device available
3313 -45 common/cmd_ide.c wrong partition selected
3314 45 common/cmd_ide.c partition selected
3315 -46 common/cmd_ide.c Unknown partition table
3316 46 common/cmd_ide.c valid partition table found
3317 -47 common/cmd_ide.c Invalid partition type
3318 47 common/cmd_ide.c correct partition type
3319 -48 common/cmd_ide.c Error reading Image Header on boot device
3320 48 common/cmd_ide.c reading Image Header from IDE device OK
3321 -49 common/cmd_ide.c Image header has bad magic number
3322 49 common/cmd_ide.c Image header has correct magic number
3323 -50 common/cmd_ide.c Image header has bad checksum
3324 50 common/cmd_ide.c Image header has correct checksum
3325 -51 common/cmd_ide.c Error reading Image from IDE device
3326 51 common/cmd_ide.c reading Image from IDE device OK
3327 52 common/cmd_nand.c before loading a Image from a NAND device
3328 -53 common/cmd_nand.c Bad usage of "nand" command
3329 53 common/cmd_nand.c correct usage of "nand" command
3330 -54 common/cmd_nand.c No boot device
3331 54 common/cmd_nand.c boot device found
3332 -55 common/cmd_nand.c Unknown Chip ID on boot device
3333 55 common/cmd_nand.c correct chip ID found, device available
3334 -56 common/cmd_nand.c Error reading Image Header on boot device
3335 56 common/cmd_nand.c reading Image Header from NAND device OK
3336 -57 common/cmd_nand.c Image header has bad magic number
3337 57 common/cmd_nand.c Image header has correct magic number
3338 -58 common/cmd_nand.c Error reading Image from NAND device
3339 58 common/cmd_nand.c reading Image from NAND device OK
3341 -60 common/env_common.c Environment has a bad CRC, using default
3343 64 net/eth.c starting with Ethernet configuration.
3344 -64 net/eth.c no Ethernet found.
3345 65 net/eth.c Ethernet found.
3347 -80 common/cmd_net.c usage wrong
3348 80 common/cmd_net.c before calling NetLoop()
3349 -81 common/cmd_net.c some error in NetLoop() occurred
3350 81 common/cmd_net.c NetLoop() back without error
3351 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3352 82 common/cmd_net.c trying automatic boot
3353 83 common/cmd_net.c running "source" command
3354 -83 common/cmd_net.c some error in automatic boot or "source" command
3355 84 common/cmd_net.c end without errors
3360 100 common/cmd_bootm.c Kernel FIT Image has correct format
3361 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3362 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3363 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3364 102 common/cmd_bootm.c Kernel unit name specified
3365 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3366 103 common/cmd_bootm.c Found configuration node
3367 104 common/cmd_bootm.c Got kernel subimage node offset
3368 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3369 105 common/cmd_bootm.c Kernel subimage hash verification OK
3370 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3371 106 common/cmd_bootm.c Architecture check OK
3372 -106 common/cmd_bootm.c Kernel subimage has wrong type
3373 107 common/cmd_bootm.c Kernel subimage type OK
3374 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3375 108 common/cmd_bootm.c Got kernel subimage data/size
3376 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3377 -109 common/cmd_bootm.c Can't get kernel subimage type
3378 -110 common/cmd_bootm.c Can't get kernel subimage comp
3379 -111 common/cmd_bootm.c Can't get kernel subimage os
3380 -112 common/cmd_bootm.c Can't get kernel subimage load address
3381 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3383 120 common/image.c Start initial ramdisk verification
3384 -120 common/image.c Ramdisk FIT image has incorrect format
3385 121 common/image.c Ramdisk FIT image has correct format
3386 122 common/image.c No ramdisk subimage unit name, using configuration
3387 -122 common/image.c Can't get configuration for ramdisk subimage
3388 123 common/image.c Ramdisk unit name specified
3389 -124 common/image.c Can't get ramdisk subimage node offset
3390 125 common/image.c Got ramdisk subimage node offset
3391 -125 common/image.c Ramdisk subimage hash verification failed
3392 126 common/image.c Ramdisk subimage hash verification OK
3393 -126 common/image.c Ramdisk subimage for unsupported architecture
3394 127 common/image.c Architecture check OK
3395 -127 common/image.c Can't get ramdisk subimage data/size
3396 128 common/image.c Got ramdisk subimage data/size
3397 129 common/image.c Can't get ramdisk load address
3398 -129 common/image.c Got ramdisk load address
3400 -130 common/cmd_doc.c Incorrect FIT image format
3401 131 common/cmd_doc.c FIT image format OK
3403 -140 common/cmd_ide.c Incorrect FIT image format
3404 141 common/cmd_ide.c FIT image format OK
3406 -150 common/cmd_nand.c Incorrect FIT image format
3407 151 common/cmd_nand.c FIT image format OK
3409 - legacy image format:
3410 CONFIG_IMAGE_FORMAT_LEGACY
3411 enables the legacy image format support in U-Boot.
3414 enabled if CONFIG_FIT_SIGNATURE is not defined.
3416 CONFIG_DISABLE_IMAGE_LEGACY
3417 disable the legacy image format
3419 This define is introduced, as the legacy image format is
3420 enabled per default for backward compatibility.
3422 - FIT image support:
3424 Enable support for the FIT uImage format.
3426 CONFIG_FIT_BEST_MATCH
3427 When no configuration is explicitly selected, default to the
3428 one whose fdt's compatibility field best matches that of
3429 U-Boot itself. A match is considered "best" if it matches the
3430 most specific compatibility entry of U-Boot's fdt's root node.
3431 The order of entries in the configuration's fdt is ignored.
3433 CONFIG_FIT_SIGNATURE
3434 This option enables signature verification of FIT uImages,
3435 using a hash signed and verified using RSA. See
3436 doc/uImage.FIT/signature.txt for more details.
3438 WARNING: When relying on signed FIT images with required
3439 signature check the legacy image format is default
3440 disabled. If a board need legacy image format support
3441 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3443 CONFIG_FIT_DISABLE_SHA256
3444 Supporting SHA256 hashes has quite an impact on binary size.
3445 For constrained systems sha256 hash support can be disabled
3448 - Standalone program support:
3449 CONFIG_STANDALONE_LOAD_ADDR
3451 This option defines a board specific value for the
3452 address where standalone program gets loaded, thus
3453 overwriting the architecture dependent default
3456 - Frame Buffer Address:
3459 Define CONFIG_FB_ADDR if you want to use specific
3460 address for frame buffer. This is typically the case
3461 when using a graphics controller has separate video
3462 memory. U-Boot will then place the frame buffer at
3463 the given address instead of dynamically reserving it
3464 in system RAM by calling lcd_setmem(), which grabs
3465 the memory for the frame buffer depending on the
3466 configured panel size.
3468 Please see board_init_f function.
3470 - Automatic software updates via TFTP server
3472 CONFIG_UPDATE_TFTP_CNT_MAX
3473 CONFIG_UPDATE_TFTP_MSEC_MAX
3475 These options enable and control the auto-update feature;
3476 for a more detailed description refer to doc/README.update.
3478 - MTD Support (mtdparts command, UBI support)
3481 Adds the MTD device infrastructure from the Linux kernel.
3482 Needed for mtdparts command support.
3484 CONFIG_MTD_PARTITIONS
3486 Adds the MTD partitioning infrastructure from the Linux
3487 kernel. Needed for UBI support.
3489 CONFIG_MTD_NAND_VERIFY_WRITE
3490 verify if the written data is correct reread.
3495 Adds commands for interacting with MTD partitions formatted
3496 with the UBI flash translation layer
3498 Requires also defining CONFIG_RBTREE
3500 CONFIG_UBI_SILENCE_MSG
3502 Make the verbose messages from UBI stop printing. This leaves
3503 warnings and errors enabled.
3506 CONFIG_MTD_UBI_WL_THRESHOLD
3507 This parameter defines the maximum difference between the highest
3508 erase counter value and the lowest erase counter value of eraseblocks
3509 of UBI devices. When this threshold is exceeded, UBI starts performing
3510 wear leveling by means of moving data from eraseblock with low erase
3511 counter to eraseblocks with high erase counter.
3513 The default value should be OK for SLC NAND flashes, NOR flashes and
3514 other flashes which have eraseblock life-cycle 100000 or more.
3515 However, in case of MLC NAND flashes which typically have eraseblock
3516 life-cycle less than 10000, the threshold should be lessened (e.g.,
3517 to 128 or 256, although it does not have to be power of 2).
3521 CONFIG_MTD_UBI_BEB_LIMIT
3522 This option specifies the maximum bad physical eraseblocks UBI
3523 expects on the MTD device (per 1024 eraseblocks). If the
3524 underlying flash does not admit of bad eraseblocks (e.g. NOR
3525 flash), this value is ignored.
3527 NAND datasheets often specify the minimum and maximum NVM
3528 (Number of Valid Blocks) for the flashes' endurance lifetime.
3529 The maximum expected bad eraseblocks per 1024 eraseblocks
3530 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3531 which gives 20 for most NANDs (MaxNVB is basically the total
3532 count of eraseblocks on the chip).
3534 To put it differently, if this value is 20, UBI will try to
3535 reserve about 1.9% of physical eraseblocks for bad blocks
3536 handling. And that will be 1.9% of eraseblocks on the entire
3537 NAND chip, not just the MTD partition UBI attaches. This means
3538 that if you have, say, a NAND flash chip admits maximum 40 bad
3539 eraseblocks, and it is split on two MTD partitions of the same
3540 size, UBI will reserve 40 eraseblocks when attaching a
3545 CONFIG_MTD_UBI_FASTMAP
3546 Fastmap is a mechanism which allows attaching an UBI device
3547 in nearly constant time. Instead of scanning the whole MTD device it
3548 only has to locate a checkpoint (called fastmap) on the device.
3549 The on-flash fastmap contains all information needed to attach
3550 the device. Using fastmap makes only sense on large devices where
3551 attaching by scanning takes long. UBI will not automatically install
3552 a fastmap on old images, but you can set the UBI parameter
3553 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3554 that fastmap-enabled images are still usable with UBI implementations
3555 without fastmap support. On typical flash devices the whole fastmap
3556 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3558 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3559 Set this parameter to enable fastmap automatically on images
3566 Adds commands for interacting with UBI volumes formatted as
3567 UBIFS. UBIFS is read-only in u-boot.
3569 Requires UBI support as well as CONFIG_LZO
3571 CONFIG_UBIFS_SILENCE_MSG
3573 Make the verbose messages from UBIFS stop printing. This leaves
3574 warnings and errors enabled.
3578 Enable building of SPL globally.
3581 LDSCRIPT for linking the SPL binary.
3583 CONFIG_SPL_MAX_FOOTPRINT
3584 Maximum size in memory allocated to the SPL, BSS included.
3585 When defined, the linker checks that the actual memory
3586 used by SPL from _start to __bss_end does not exceed it.
3587 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3588 must not be both defined at the same time.
3591 Maximum size of the SPL image (text, data, rodata, and
3592 linker lists sections), BSS excluded.
3593 When defined, the linker checks that the actual size does
3596 CONFIG_SPL_TEXT_BASE
3597 TEXT_BASE for linking the SPL binary.
3599 CONFIG_SPL_RELOC_TEXT_BASE
3600 Address to relocate to. If unspecified, this is equal to
3601 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3603 CONFIG_SPL_BSS_START_ADDR
3604 Link address for the BSS within the SPL binary.
3606 CONFIG_SPL_BSS_MAX_SIZE
3607 Maximum size in memory allocated to the SPL BSS.
3608 When defined, the linker checks that the actual memory used
3609 by SPL from __bss_start to __bss_end does not exceed it.
3610 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3611 must not be both defined at the same time.
3614 Adress of the start of the stack SPL will use
3616 CONFIG_SPL_RELOC_STACK
3617 Adress of the start of the stack SPL will use after
3618 relocation. If unspecified, this is equal to
3621 CONFIG_SYS_SPL_MALLOC_START
3622 Starting address of the malloc pool used in SPL.
3624 CONFIG_SYS_SPL_MALLOC_SIZE
3625 The size of the malloc pool used in SPL.
3627 CONFIG_SPL_FRAMEWORK
3628 Enable the SPL framework under common/. This framework
3629 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3630 NAND loading of the Linux Kernel.
3633 Enable booting directly to an OS from SPL.
3634 See also: doc/README.falcon
3636 CONFIG_SPL_DISPLAY_PRINT
3637 For ARM, enable an optional function to print more information
3638 about the running system.
3640 CONFIG_SPL_INIT_MINIMAL
3641 Arch init code should be built for a very small image
3643 CONFIG_SPL_LIBCOMMON_SUPPORT
3644 Support for common/libcommon.o in SPL binary
3646 CONFIG_SPL_LIBDISK_SUPPORT
3647 Support for disk/libdisk.o in SPL binary
3649 CONFIG_SPL_I2C_SUPPORT
3650 Support for drivers/i2c/libi2c.o in SPL binary
3652 CONFIG_SPL_GPIO_SUPPORT
3653 Support for drivers/gpio/libgpio.o in SPL binary
3655 CONFIG_SPL_MMC_SUPPORT
3656 Support for drivers/mmc/libmmc.o in SPL binary
3658 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3659 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3660 CONFIG_SYS_MMC_SD_FS_BOOT_PARTITION
3661 Address, size and partition on the MMC to load U-Boot from
3662 when the MMC is being used in raw mode.
3664 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3665 Sector to load kernel uImage from when MMC is being
3666 used in raw mode (for Falcon mode)
3668 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3669 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3670 Sector and number of sectors to load kernel argument
3671 parameters from when MMC is being used in raw mode
3674 CONFIG_SPL_FAT_SUPPORT
3675 Support for fs/fat/libfat.o in SPL binary
3677 CONFIG_SPL_EXT_SUPPORT
3678 Support for EXT filesystem in SPL binary
3680 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3681 Filename to read to load U-Boot when reading from filesystem
3683 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3684 Filename to read to load kernel uImage when reading
3685 from filesystem (for Falcon mode)
3687 CONFIG_SPL_FS_LOAD_ARGS_NAME
3688 Filename to read to load kernel argument parameters
3689 when reading from filesystem (for Falcon mode)
3691 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3692 Set this for NAND SPL on PPC mpc83xx targets, so that
3693 start.S waits for the rest of the SPL to load before
3694 continuing (the hardware starts execution after just
3695 loading the first page rather than the full 4K).
3697 CONFIG_SPL_SKIP_RELOCATE
3698 Avoid SPL relocation
3700 CONFIG_SPL_NAND_BASE
3701 Include nand_base.c in the SPL. Requires
3702 CONFIG_SPL_NAND_DRIVERS.
3704 CONFIG_SPL_NAND_DRIVERS
3705 SPL uses normal NAND drivers, not minimal drivers.
3708 Include standard software ECC in the SPL
3710 CONFIG_SPL_NAND_SIMPLE
3711 Support for NAND boot using simple NAND drivers that
3712 expose the cmd_ctrl() interface.
3714 CONFIG_SPL_MTD_SUPPORT
3715 Support for the MTD subsystem within SPL. Useful for
3716 environment on NAND support within SPL.
3718 CONFIG_SPL_NAND_RAW_ONLY
3719 Support to boot only raw u-boot.bin images. Use this only
3720 if you need to save space.
3722 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3723 Set for the SPL on PPC mpc8xxx targets, support for
3724 drivers/ddr/fsl/libddr.o in SPL binary.
3726 CONFIG_SPL_COMMON_INIT_DDR
3727 Set for common ddr init with serial presence detect in
3730 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3731 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3732 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3733 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3734 CONFIG_SYS_NAND_ECCBYTES
3735 Defines the size and behavior of the NAND that SPL uses
3738 CONFIG_SPL_NAND_BOOT
3739 Add support NAND boot
3741 CONFIG_SYS_NAND_U_BOOT_OFFS
3742 Location in NAND to read U-Boot from
3744 CONFIG_SYS_NAND_U_BOOT_DST
3745 Location in memory to load U-Boot to
3747 CONFIG_SYS_NAND_U_BOOT_SIZE
3748 Size of image to load
3750 CONFIG_SYS_NAND_U_BOOT_START
3751 Entry point in loaded image to jump to
3753 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3754 Define this if you need to first read the OOB and then the
3755 data. This is used for example on davinci plattforms.
3757 CONFIG_SPL_OMAP3_ID_NAND
3758 Support for an OMAP3-specific set of functions to return the
3759 ID and MFR of the first attached NAND chip, if present.
3761 CONFIG_SPL_SERIAL_SUPPORT
3762 Support for drivers/serial/libserial.o in SPL binary
3764 CONFIG_SPL_SPI_FLASH_SUPPORT
3765 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3767 CONFIG_SPL_SPI_SUPPORT
3768 Support for drivers/spi/libspi.o in SPL binary
3770 CONFIG_SPL_RAM_DEVICE
3771 Support for running image already present in ram, in SPL binary
3773 CONFIG_SPL_LIBGENERIC_SUPPORT
3774 Support for lib/libgeneric.o in SPL binary
3776 CONFIG_SPL_ENV_SUPPORT
3777 Support for the environment operating in SPL binary
3779 CONFIG_SPL_NET_SUPPORT
3780 Support for the net/libnet.o in SPL binary.
3781 It conflicts with SPL env from storage medium specified by
3782 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3785 Image offset to which the SPL should be padded before appending
3786 the SPL payload. By default, this is defined as
3787 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3788 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3789 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3792 Final target image containing SPL and payload. Some SPLs
3793 use an arch-specific makefile fragment instead, for
3794 example if more than one image needs to be produced.
3796 CONFIG_FIT_SPL_PRINT
3797 Printing information about a FIT image adds quite a bit of
3798 code to SPL. So this is normally disabled in SPL. Use this
3799 option to re-enable it. This will affect the output of the
3800 bootm command when booting a FIT image.
3804 Enable building of TPL globally.
3807 Image offset to which the TPL should be padded before appending
3808 the TPL payload. By default, this is defined as
3809 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3810 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3811 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3816 [so far only for SMDK2400 boards]
3818 - Modem support enable:
3819 CONFIG_MODEM_SUPPORT
3821 - RTS/CTS Flow control enable:
3824 - Modem debug support:
3825 CONFIG_MODEM_SUPPORT_DEBUG
3827 Enables debugging stuff (char screen[1024], dbg())
3828 for modem support. Useful only with BDI2000.
3830 - Interrupt support (PPC):
3832 There are common interrupt_init() and timer_interrupt()
3833 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3834 for CPU specific initialization. interrupt_init_cpu()
3835 should set decrementer_count to appropriate value. If
3836 CPU resets decrementer automatically after interrupt
3837 (ppc4xx) it should set decrementer_count to zero.
3838 timer_interrupt() calls timer_interrupt_cpu() for CPU
3839 specific handling. If board has watchdog / status_led
3840 / other_activity_monitor it works automatically from
3841 general timer_interrupt().
3845 In the target system modem support is enabled when a
3846 specific key (key combination) is pressed during
3847 power-on. Otherwise U-Boot will boot normally
3848 (autoboot). The key_pressed() function is called from
3849 board_init(). Currently key_pressed() is a dummy
3850 function, returning 1 and thus enabling modem
3853 If there are no modem init strings in the
3854 environment, U-Boot proceed to autoboot; the
3855 previous output (banner, info printfs) will be
3858 See also: doc/README.Modem
3860 Board initialization settings:
3861 ------------------------------
3863 During Initialization u-boot calls a number of board specific functions
3864 to allow the preparation of board specific prerequisites, e.g. pin setup
3865 before drivers are initialized. To enable these callbacks the
3866 following configuration macros have to be defined. Currently this is
3867 architecture specific, so please check arch/your_architecture/lib/board.c
3868 typically in board_init_f() and board_init_r().
3870 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3871 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3872 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3873 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3875 Configuration Settings:
3876 -----------------------
3878 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3879 Optionally it can be defined to support 64-bit memory commands.
3881 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3882 undefine this when you're short of memory.
3884 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3885 width of the commands listed in the 'help' command output.
3887 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3888 prompt for user input.
3890 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3892 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3894 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3896 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3897 the application (usually a Linux kernel) when it is
3900 - CONFIG_SYS_BAUDRATE_TABLE:
3901 List of legal baudrate settings for this board.
3903 - CONFIG_SYS_CONSOLE_INFO_QUIET
3904 Suppress display of console information at boot.
3906 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3907 If the board specific function
3908 extern int overwrite_console (void);
3909 returns 1, the stdin, stderr and stdout are switched to the
3910 serial port, else the settings in the environment are used.
3912 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3913 Enable the call to overwrite_console().
3915 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3916 Enable overwrite of previous console environment settings.
3918 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3919 Begin and End addresses of the area used by the
3922 - CONFIG_SYS_ALT_MEMTEST:
3923 Enable an alternate, more extensive memory test.
3925 - CONFIG_SYS_MEMTEST_SCRATCH:
3926 Scratch address used by the alternate memory test
3927 You only need to set this if address zero isn't writeable
3929 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3930 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3931 this specified memory area will get subtracted from the top
3932 (end) of RAM and won't get "touched" at all by U-Boot. By
3933 fixing up gd->ram_size the Linux kernel should gets passed
3934 the now "corrected" memory size and won't touch it either.
3935 This should work for arch/ppc and arch/powerpc. Only Linux
3936 board ports in arch/powerpc with bootwrapper support that
3937 recalculate the memory size from the SDRAM controller setup
3938 will have to get fixed in Linux additionally.
3940 This option can be used as a workaround for the 440EPx/GRx
3941 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3944 WARNING: Please make sure that this value is a multiple of
3945 the Linux page size (normally 4k). If this is not the case,
3946 then the end address of the Linux memory will be located at a
3947 non page size aligned address and this could cause major
3950 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3951 Enable temporary baudrate change while serial download
3953 - CONFIG_SYS_SDRAM_BASE:
3954 Physical start address of SDRAM. _Must_ be 0 here.
3956 - CONFIG_SYS_MBIO_BASE:
3957 Physical start address of Motherboard I/O (if using a
3960 - CONFIG_SYS_FLASH_BASE:
3961 Physical start address of Flash memory.
3963 - CONFIG_SYS_MONITOR_BASE:
3964 Physical start address of boot monitor code (set by
3965 make config files to be same as the text base address
3966 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3967 CONFIG_SYS_FLASH_BASE when booting from flash.
3969 - CONFIG_SYS_MONITOR_LEN:
3970 Size of memory reserved for monitor code, used to
3971 determine _at_compile_time_ (!) if the environment is
3972 embedded within the U-Boot image, or in a separate
3975 - CONFIG_SYS_MALLOC_LEN:
3976 Size of DRAM reserved for malloc() use.
3978 - CONFIG_SYS_MALLOC_F_LEN
3979 Size of the malloc() pool for use before relocation. If
3980 this is defined, then a very simple malloc() implementation
3981 will become available before relocation. The address is just
3982 below the global data, and the stack is moved down to make
3985 This feature allocates regions with increasing addresses
3986 within the region. calloc() is supported, but realloc()
3987 is not available. free() is supported but does nothing.
3988 The memory will be freed (or in fact just forgotton) when
3989 U-Boot relocates itself.
3991 Pre-relocation malloc() is only supported on ARM and sandbox
3992 at present but is fairly easy to enable for other archs.
3994 - CONFIG_SYS_MALLOC_SIMPLE
3995 Provides a simple and small malloc() and calloc() for those
3996 boards which do not use the full malloc in SPL (which is
3997 enabled with CONFIG_SYS_SPL_MALLOC_START).
3999 - CONFIG_SYS_BOOTM_LEN:
4000 Normally compressed uImages are limited to an
4001 uncompressed size of 8 MBytes. If this is not enough,
4002 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4003 to adjust this setting to your needs.
4005 - CONFIG_SYS_BOOTMAPSZ:
4006 Maximum size of memory mapped by the startup code of
4007 the Linux kernel; all data that must be processed by
4008 the Linux kernel (bd_info, boot arguments, FDT blob if
4009 used) must be put below this limit, unless "bootm_low"
4010 environment variable is defined and non-zero. In such case
4011 all data for the Linux kernel must be between "bootm_low"
4012 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4013 variable "bootm_mapsize" will override the value of
4014 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4015 then the value in "bootm_size" will be used instead.
4017 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4018 Enable initrd_high functionality. If defined then the
4019 initrd_high feature is enabled and the bootm ramdisk subcommand
4022 - CONFIG_SYS_BOOT_GET_CMDLINE:
4023 Enables allocating and saving kernel cmdline in space between
4024 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4026 - CONFIG_SYS_BOOT_GET_KBD:
4027 Enables allocating and saving a kernel copy of the bd_info in
4028 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4030 - CONFIG_SYS_MAX_FLASH_BANKS:
4031 Max number of Flash memory banks
4033 - CONFIG_SYS_MAX_FLASH_SECT:
4034 Max number of sectors on a Flash chip
4036 - CONFIG_SYS_FLASH_ERASE_TOUT:
4037 Timeout for Flash erase operations (in ms)
4039 - CONFIG_SYS_FLASH_WRITE_TOUT:
4040 Timeout for Flash write operations (in ms)
4042 - CONFIG_SYS_FLASH_LOCK_TOUT
4043 Timeout for Flash set sector lock bit operation (in ms)
4045 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4046 Timeout for Flash clear lock bits operation (in ms)
4048 - CONFIG_SYS_FLASH_PROTECTION
4049 If defined, hardware flash sectors protection is used
4050 instead of U-Boot software protection.
4052 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4054 Enable TFTP transfers directly to flash memory;
4055 without this option such a download has to be
4056 performed in two steps: (1) download to RAM, and (2)
4057 copy from RAM to flash.
4059 The two-step approach is usually more reliable, since
4060 you can check if the download worked before you erase
4061 the flash, but in some situations (when system RAM is
4062 too limited to allow for a temporary copy of the
4063 downloaded image) this option may be very useful.
4065 - CONFIG_SYS_FLASH_CFI:
4066 Define if the flash driver uses extra elements in the
4067 common flash structure for storing flash geometry.
4069 - CONFIG_FLASH_CFI_DRIVER
4070 This option also enables the building of the cfi_flash driver
4071 in the drivers directory
4073 - CONFIG_FLASH_CFI_MTD
4074 This option enables the building of the cfi_mtd driver
4075 in the drivers directory. The driver exports CFI flash
4078 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4079 Use buffered writes to flash.
4081 - CONFIG_FLASH_SPANSION_S29WS_N
4082 s29ws-n MirrorBit flash has non-standard addresses for buffered
4085 - CONFIG_SYS_FLASH_QUIET_TEST
4086 If this option is defined, the common CFI flash doesn't
4087 print it's warning upon not recognized FLASH banks. This
4088 is useful, if some of the configured banks are only
4089 optionally available.
4091 - CONFIG_FLASH_SHOW_PROGRESS
4092 If defined (must be an integer), print out countdown
4093 digits and dots. Recommended value: 45 (9..1) for 80
4094 column displays, 15 (3..1) for 40 column displays.
4096 - CONFIG_FLASH_VERIFY
4097 If defined, the content of the flash (destination) is compared
4098 against the source after the write operation. An error message
4099 will be printed when the contents are not identical.
4100 Please note that this option is useless in nearly all cases,
4101 since such flash programming errors usually are detected earlier
4102 while unprotecting/erasing/programming. Please only enable
4103 this option if you really know what you are doing.
4105 - CONFIG_SYS_RX_ETH_BUFFER:
4106 Defines the number of Ethernet receive buffers. On some
4107 Ethernet controllers it is recommended to set this value
4108 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4109 buffers can be full shortly after enabling the interface
4110 on high Ethernet traffic.
4111 Defaults to 4 if not defined.
4113 - CONFIG_ENV_MAX_ENTRIES
4115 Maximum number of entries in the hash table that is used
4116 internally to store the environment settings. The default
4117 setting is supposed to be generous and should work in most
4118 cases. This setting can be used to tune behaviour; see
4119 lib/hashtable.c for details.
4121 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4122 - CONFIG_ENV_FLAGS_LIST_STATIC
4123 Enable validation of the values given to environment variables when
4124 calling env set. Variables can be restricted to only decimal,
4125 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4126 the variables can also be restricted to IP address or MAC address.
4128 The format of the list is:
4129 type_attribute = [s|d|x|b|i|m]
4130 access_atribute = [a|r|o|c]
4131 attributes = type_attribute[access_atribute]
4132 entry = variable_name[:attributes]
4135 The type attributes are:
4136 s - String (default)
4139 b - Boolean ([1yYtT|0nNfF])
4143 The access attributes are:
4149 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4150 Define this to a list (string) to define the ".flags"
4151 envirnoment variable in the default or embedded environment.
4153 - CONFIG_ENV_FLAGS_LIST_STATIC
4154 Define this to a list (string) to define validation that
4155 should be done if an entry is not found in the ".flags"
4156 environment variable. To override a setting in the static
4157 list, simply add an entry for the same variable name to the
4160 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4161 If defined, don't allow the -f switch to env set override variable
4164 - CONFIG_SYS_GENERIC_BOARD
4165 This selects the architecture-generic board system instead of the
4166 architecture-specific board files. It is intended to move boards
4167 to this new framework over time. Defining this will disable the
4168 arch/foo/lib/board.c file and use common/board_f.c and
4169 common/board_r.c instead. To use this option your architecture
4170 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4171 its config.mk file). If you find problems enabling this option on
4172 your board please report the problem and send patches!
4174 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4175 This is set by OMAP boards for the max time that reset should
4176 be asserted. See doc/README.omap-reset-time for details on how
4177 the value can be calulated on a given board.
4180 If stdint.h is available with your toolchain you can define this
4181 option to enable it. You can provide option 'USE_STDINT=1' when
4182 building U-Boot to enable this.
4184 The following definitions that deal with the placement and management
4185 of environment data (variable area); in general, we support the
4186 following configurations:
4188 - CONFIG_BUILD_ENVCRC:
4190 Builds up envcrc with the target environment so that external utils
4191 may easily extract it and embed it in final U-Boot images.
4193 - CONFIG_ENV_IS_IN_FLASH:
4195 Define this if the environment is in flash memory.
4197 a) The environment occupies one whole flash sector, which is
4198 "embedded" in the text segment with the U-Boot code. This
4199 happens usually with "bottom boot sector" or "top boot
4200 sector" type flash chips, which have several smaller
4201 sectors at the start or the end. For instance, such a
4202 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4203 such a case you would place the environment in one of the
4204 4 kB sectors - with U-Boot code before and after it. With
4205 "top boot sector" type flash chips, you would put the
4206 environment in one of the last sectors, leaving a gap
4207 between U-Boot and the environment.
4209 - CONFIG_ENV_OFFSET:
4211 Offset of environment data (variable area) to the
4212 beginning of flash memory; for instance, with bottom boot
4213 type flash chips the second sector can be used: the offset
4214 for this sector is given here.
4216 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4220 This is just another way to specify the start address of
4221 the flash sector containing the environment (instead of
4224 - CONFIG_ENV_SECT_SIZE:
4226 Size of the sector containing the environment.
4229 b) Sometimes flash chips have few, equal sized, BIG sectors.
4230 In such a case you don't want to spend a whole sector for
4235 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4236 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4237 of this flash sector for the environment. This saves
4238 memory for the RAM copy of the environment.
4240 It may also save flash memory if you decide to use this
4241 when your environment is "embedded" within U-Boot code,
4242 since then the remainder of the flash sector could be used
4243 for U-Boot code. It should be pointed out that this is
4244 STRONGLY DISCOURAGED from a robustness point of view:
4245 updating the environment in flash makes it always
4246 necessary to erase the WHOLE sector. If something goes
4247 wrong before the contents has been restored from a copy in
4248 RAM, your target system will be dead.
4250 - CONFIG_ENV_ADDR_REDUND
4251 CONFIG_ENV_SIZE_REDUND
4253 These settings describe a second storage area used to hold
4254 a redundant copy of the environment data, so that there is
4255 a valid backup copy in case there is a power failure during
4256 a "saveenv" operation.
4258 BE CAREFUL! Any changes to the flash layout, and some changes to the
4259 source code will make it necessary to adapt <board>/u-boot.lds*
4263 - CONFIG_ENV_IS_IN_NVRAM:
4265 Define this if you have some non-volatile memory device
4266 (NVRAM, battery buffered SRAM) which you want to use for the
4272 These two #defines are used to determine the memory area you
4273 want to use for environment. It is assumed that this memory
4274 can just be read and written to, without any special
4277 BE CAREFUL! The first access to the environment happens quite early
4278 in U-Boot initalization (when we try to get the setting of for the
4279 console baudrate). You *MUST* have mapped your NVRAM area then, or
4282 Please note that even with NVRAM we still use a copy of the
4283 environment in RAM: we could work on NVRAM directly, but we want to
4284 keep settings there always unmodified except somebody uses "saveenv"
4285 to save the current settings.
4288 - CONFIG_ENV_IS_IN_EEPROM:
4290 Use this if you have an EEPROM or similar serial access
4291 device and a driver for it.
4293 - CONFIG_ENV_OFFSET:
4296 These two #defines specify the offset and size of the
4297 environment area within the total memory of your EEPROM.
4299 - CONFIG_SYS_I2C_EEPROM_ADDR:
4300 If defined, specified the chip address of the EEPROM device.
4301 The default address is zero.
4303 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4304 If defined, the number of bits used to address bytes in a
4305 single page in the EEPROM device. A 64 byte page, for example
4306 would require six bits.
4308 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4309 If defined, the number of milliseconds to delay between
4310 page writes. The default is zero milliseconds.
4312 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4313 The length in bytes of the EEPROM memory array address. Note
4314 that this is NOT the chip address length!
4316 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4317 EEPROM chips that implement "address overflow" are ones
4318 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4319 address and the extra bits end up in the "chip address" bit
4320 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4323 Note that we consider the length of the address field to
4324 still be one byte because the extra address bits are hidden
4325 in the chip address.
4327 - CONFIG_SYS_EEPROM_SIZE:
4328 The size in bytes of the EEPROM device.
4330 - CONFIG_ENV_EEPROM_IS_ON_I2C
4331 define this, if you have I2C and SPI activated, and your
4332 EEPROM, which holds the environment, is on the I2C bus.
4334 - CONFIG_I2C_ENV_EEPROM_BUS
4335 if you have an Environment on an EEPROM reached over
4336 I2C muxes, you can define here, how to reach this
4337 EEPROM. For example:
4339 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4341 EEPROM which holds the environment, is reached over
4342 a pca9547 i2c mux with address 0x70, channel 3.
4344 - CONFIG_ENV_IS_IN_DATAFLASH:
4346 Define this if you have a DataFlash memory device which you
4347 want to use for the environment.
4349 - CONFIG_ENV_OFFSET:
4353 These three #defines specify the offset and size of the
4354 environment area within the total memory of your DataFlash placed
4355 at the specified address.
4357 - CONFIG_ENV_IS_IN_SPI_FLASH:
4359 Define this if you have a SPI Flash memory device which you
4360 want to use for the environment.
4362 - CONFIG_ENV_OFFSET:
4365 These two #defines specify the offset and size of the
4366 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4367 aligned to an erase sector boundary.
4369 - CONFIG_ENV_SECT_SIZE:
4371 Define the SPI flash's sector size.
4373 - CONFIG_ENV_OFFSET_REDUND (optional):
4375 This setting describes a second storage area of CONFIG_ENV_SIZE
4376 size used to hold a redundant copy of the environment data, so
4377 that there is a valid backup copy in case there is a power failure
4378 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4379 aligned to an erase sector boundary.
4381 - CONFIG_ENV_SPI_BUS (optional):
4382 - CONFIG_ENV_SPI_CS (optional):
4384 Define the SPI bus and chip select. If not defined they will be 0.
4386 - CONFIG_ENV_SPI_MAX_HZ (optional):
4388 Define the SPI max work clock. If not defined then use 1MHz.
4390 - CONFIG_ENV_SPI_MODE (optional):
4392 Define the SPI work mode. If not defined then use SPI_MODE_3.
4394 - CONFIG_ENV_IS_IN_REMOTE:
4396 Define this if you have a remote memory space which you
4397 want to use for the local device's environment.
4402 These two #defines specify the address and size of the
4403 environment area within the remote memory space. The
4404 local device can get the environment from remote memory
4405 space by SRIO or PCIE links.
4407 BE CAREFUL! For some special cases, the local device can not use
4408 "saveenv" command. For example, the local device will get the
4409 environment stored in a remote NOR flash by SRIO or PCIE link,
4410 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4412 - CONFIG_ENV_IS_IN_NAND:
4414 Define this if you have a NAND device which you want to use
4415 for the environment.
4417 - CONFIG_ENV_OFFSET:
4420 These two #defines specify the offset and size of the environment
4421 area within the first NAND device. CONFIG_ENV_OFFSET must be
4422 aligned to an erase block boundary.
4424 - CONFIG_ENV_OFFSET_REDUND (optional):
4426 This setting describes a second storage area of CONFIG_ENV_SIZE
4427 size used to hold a redundant copy of the environment data, so
4428 that there is a valid backup copy in case there is a power failure
4429 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4430 aligned to an erase block boundary.
4432 - CONFIG_ENV_RANGE (optional):
4434 Specifies the length of the region in which the environment
4435 can be written. This should be a multiple of the NAND device's
4436 block size. Specifying a range with more erase blocks than
4437 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4438 the range to be avoided.
4440 - CONFIG_ENV_OFFSET_OOB (optional):
4442 Enables support for dynamically retrieving the offset of the
4443 environment from block zero's out-of-band data. The
4444 "nand env.oob" command can be used to record this offset.
4445 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4446 using CONFIG_ENV_OFFSET_OOB.
4448 - CONFIG_NAND_ENV_DST
4450 Defines address in RAM to which the nand_spl code should copy the
4451 environment. If redundant environment is used, it will be copied to
4452 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4454 - CONFIG_ENV_IS_IN_UBI:
4456 Define this if you have an UBI volume that you want to use for the
4457 environment. This has the benefit of wear-leveling the environment
4458 accesses, which is important on NAND.
4460 - CONFIG_ENV_UBI_PART:
4462 Define this to a string that is the mtd partition containing the UBI.
4464 - CONFIG_ENV_UBI_VOLUME:
4466 Define this to the name of the volume that you want to store the
4469 - CONFIG_ENV_UBI_VOLUME_REDUND:
4471 Define this to the name of another volume to store a second copy of
4472 the environment in. This will enable redundant environments in UBI.
4473 It is assumed that both volumes are in the same MTD partition.
4475 - CONFIG_UBI_SILENCE_MSG
4476 - CONFIG_UBIFS_SILENCE_MSG
4478 You will probably want to define these to avoid a really noisy system
4479 when storing the env in UBI.
4481 - CONFIG_ENV_IS_IN_FAT:
4482 Define this if you want to use the FAT file system for the environment.
4484 - FAT_ENV_INTERFACE:
4486 Define this to a string that is the name of the block device.
4488 - FAT_ENV_DEV_AND_PART:
4490 Define this to a string to specify the partition of the device. It can
4493 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4494 - "D:P": device D partition P. Error occurs if device D has no
4497 - "D" or "D:": device D partition 1 if device D has partition
4498 table, or the whole device D if has no partition
4500 - "D:auto": first partition in device D with bootable flag set.
4501 If none, first valid paratition in device D. If no
4502 partition table then means device D.
4506 It's a string of the FAT file name. This file use to store the
4510 This should be defined. Otherwise it cannot save the envrionment file.
4512 - CONFIG_ENV_IS_IN_MMC:
4514 Define this if you have an MMC device which you want to use for the
4517 - CONFIG_SYS_MMC_ENV_DEV:
4519 Specifies which MMC device the environment is stored in.
4521 - CONFIG_SYS_MMC_ENV_PART (optional):
4523 Specifies which MMC partition the environment is stored in. If not
4524 set, defaults to partition 0, the user area. Common values might be
4525 1 (first MMC boot partition), 2 (second MMC boot partition).
4527 - CONFIG_ENV_OFFSET:
4530 These two #defines specify the offset and size of the environment
4531 area within the specified MMC device.
4533 If offset is positive (the usual case), it is treated as relative to
4534 the start of the MMC partition. If offset is negative, it is treated
4535 as relative to the end of the MMC partition. This can be useful if
4536 your board may be fitted with different MMC devices, which have
4537 different sizes for the MMC partitions, and you always want the
4538 environment placed at the very end of the partition, to leave the
4539 maximum possible space before it, to store other data.
4541 These two values are in units of bytes, but must be aligned to an
4542 MMC sector boundary.
4544 - CONFIG_ENV_OFFSET_REDUND (optional):
4546 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4547 hold a redundant copy of the environment data. This provides a
4548 valid backup copy in case the other copy is corrupted, e.g. due
4549 to a power failure during a "saveenv" operation.
4551 This value may also be positive or negative; this is handled in the
4552 same way as CONFIG_ENV_OFFSET.
4554 This value is also in units of bytes, but must also be aligned to
4555 an MMC sector boundary.
4557 - CONFIG_ENV_SIZE_REDUND (optional):
4559 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4560 set. If this value is set, it must be set to the same value as
4563 - CONFIG_SYS_SPI_INIT_OFFSET
4565 Defines offset to the initial SPI buffer area in DPRAM. The
4566 area is used at an early stage (ROM part) if the environment
4567 is configured to reside in the SPI EEPROM: We need a 520 byte
4568 scratch DPRAM area. It is used between the two initialization
4569 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4570 to be a good choice since it makes it far enough from the
4571 start of the data area as well as from the stack pointer.
4573 Please note that the environment is read-only until the monitor
4574 has been relocated to RAM and a RAM copy of the environment has been
4575 created; also, when using EEPROM you will have to use getenv_f()
4576 until then to read environment variables.
4578 The environment is protected by a CRC32 checksum. Before the monitor
4579 is relocated into RAM, as a result of a bad CRC you will be working
4580 with the compiled-in default environment - *silently*!!! [This is
4581 necessary, because the first environment variable we need is the
4582 "baudrate" setting for the console - if we have a bad CRC, we don't
4583 have any device yet where we could complain.]
4585 Note: once the monitor has been relocated, then it will complain if
4586 the default environment is used; a new CRC is computed as soon as you
4587 use the "saveenv" command to store a valid environment.
4589 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4590 Echo the inverted Ethernet link state to the fault LED.
4592 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4593 also needs to be defined.
4595 - CONFIG_SYS_FAULT_MII_ADDR:
4596 MII address of the PHY to check for the Ethernet link state.
4598 - CONFIG_NS16550_MIN_FUNCTIONS:
4599 Define this if you desire to only have use of the NS16550_init
4600 and NS16550_putc functions for the serial driver located at
4601 drivers/serial/ns16550.c. This option is useful for saving
4602 space for already greatly restricted images, including but not
4603 limited to NAND_SPL configurations.
4605 - CONFIG_DISPLAY_BOARDINFO
4606 Display information about the board that U-Boot is running on
4607 when U-Boot starts up. The board function checkboard() is called
4610 - CONFIG_DISPLAY_BOARDINFO_LATE
4611 Similar to the previous option, but display this information
4612 later, once stdio is running and output goes to the LCD, if
4615 - CONFIG_BOARD_SIZE_LIMIT:
4616 Maximum size of the U-Boot image. When defined, the
4617 build system checks that the actual size does not
4620 Low Level (hardware related) configuration options:
4621 ---------------------------------------------------
4623 - CONFIG_SYS_CACHELINE_SIZE:
4624 Cache Line Size of the CPU.
4626 - CONFIG_SYS_DEFAULT_IMMR:
4627 Default address of the IMMR after system reset.
4629 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4630 and RPXsuper) to be able to adjust the position of
4631 the IMMR register after a reset.
4633 - CONFIG_SYS_CCSRBAR_DEFAULT:
4634 Default (power-on reset) physical address of CCSR on Freescale
4637 - CONFIG_SYS_CCSRBAR:
4638 Virtual address of CCSR. On a 32-bit build, this is typically
4639 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4641 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4642 for cross-platform code that uses that macro instead.
4644 - CONFIG_SYS_CCSRBAR_PHYS:
4645 Physical address of CCSR. CCSR can be relocated to a new
4646 physical address, if desired. In this case, this macro should
4647 be set to that address. Otherwise, it should be set to the
4648 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4649 is typically relocated on 36-bit builds. It is recommended
4650 that this macro be defined via the _HIGH and _LOW macros:
4652 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4653 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4655 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4656 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4657 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4658 used in assembly code, so it must not contain typecasts or
4659 integer size suffixes (e.g. "ULL").
4661 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4662 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4663 used in assembly code, so it must not contain typecasts or
4664 integer size suffixes (e.g. "ULL").
4666 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4667 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4668 forced to a value that ensures that CCSR is not relocated.
4670 - Floppy Disk Support:
4671 CONFIG_SYS_FDC_DRIVE_NUMBER
4673 the default drive number (default value 0)
4675 CONFIG_SYS_ISA_IO_STRIDE
4677 defines the spacing between FDC chipset registers
4680 CONFIG_SYS_ISA_IO_OFFSET
4682 defines the offset of register from address. It
4683 depends on which part of the data bus is connected to
4684 the FDC chipset. (default value 0)
4686 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4687 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4690 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4691 fdc_hw_init() is called at the beginning of the FDC
4692 setup. fdc_hw_init() must be provided by the board
4693 source code. It is used to make hardware dependant
4697 Most IDE controllers were designed to be connected with PCI
4698 interface. Only few of them were designed for AHB interface.
4699 When software is doing ATA command and data transfer to
4700 IDE devices through IDE-AHB controller, some additional
4701 registers accessing to these kind of IDE-AHB controller
4704 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4705 DO NOT CHANGE unless you know exactly what you're
4706 doing! (11-4) [MPC8xx/82xx systems only]
4708 - CONFIG_SYS_INIT_RAM_ADDR:
4710 Start address of memory area that can be used for
4711 initial data and stack; please note that this must be
4712 writable memory that is working WITHOUT special
4713 initialization, i. e. you CANNOT use normal RAM which
4714 will become available only after programming the
4715 memory controller and running certain initialization
4718 U-Boot uses the following memory types:
4719 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4720 - MPC824X: data cache
4721 - PPC4xx: data cache
4723 - CONFIG_SYS_GBL_DATA_OFFSET:
4725 Offset of the initial data structure in the memory
4726 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4727 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4728 data is located at the end of the available space
4729 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4730 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4731 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4732 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4735 On the MPC824X (or other systems that use the data
4736 cache for initial memory) the address chosen for
4737 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4738 point to an otherwise UNUSED address space between
4739 the top of RAM and the start of the PCI space.
4741 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4743 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4745 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4747 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4749 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4751 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4753 - CONFIG_SYS_OR_TIMING_SDRAM:
4756 - CONFIG_SYS_MAMR_PTA:
4757 periodic timer for refresh
4759 - CONFIG_SYS_DER: Debug Event Register (37-47)
4761 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4762 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4763 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4764 CONFIG_SYS_BR1_PRELIM:
4765 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4767 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4768 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4769 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4770 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4772 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4773 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4774 Machine Mode Register and Memory Periodic Timer
4775 Prescaler definitions (SDRAM timing)
4777 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4778 enable I2C microcode relocation patch (MPC8xx);
4779 define relocation offset in DPRAM [DSP2]
4781 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4782 enable SMC microcode relocation patch (MPC8xx);
4783 define relocation offset in DPRAM [SMC1]
4785 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4786 enable SPI microcode relocation patch (MPC8xx);
4787 define relocation offset in DPRAM [SCC4]
4789 - CONFIG_SYS_USE_OSCCLK:
4790 Use OSCM clock mode on MBX8xx board. Be careful,
4791 wrong setting might damage your board. Read
4792 doc/README.MBX before setting this variable!
4794 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4795 Offset of the bootmode word in DPRAM used by post
4796 (Power On Self Tests). This definition overrides
4797 #define'd default value in commproc.h resp.
4800 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4801 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4802 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4803 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4804 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4805 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4806 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4807 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4808 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4810 - CONFIG_PCI_DISABLE_PCIE:
4811 Disable PCI-Express on systems where it is supported but not
4814 - CONFIG_PCI_ENUM_ONLY
4815 Only scan through and get the devices on the busses.
4816 Don't do any setup work, presumably because someone or
4817 something has already done it, and we don't need to do it
4818 a second time. Useful for platforms that are pre-booted
4819 by coreboot or similar.
4821 - CONFIG_PCI_INDIRECT_BRIDGE:
4822 Enable support for indirect PCI bridges.
4825 Chip has SRIO or not
4828 Board has SRIO 1 port available
4831 Board has SRIO 2 port available
4833 - CONFIG_SRIO_PCIE_BOOT_MASTER
4834 Board can support master function for Boot from SRIO and PCIE
4836 - CONFIG_SYS_SRIOn_MEM_VIRT:
4837 Virtual Address of SRIO port 'n' memory region
4839 - CONFIG_SYS_SRIOn_MEM_PHYS:
4840 Physical Address of SRIO port 'n' memory region
4842 - CONFIG_SYS_SRIOn_MEM_SIZE:
4843 Size of SRIO port 'n' memory region
4845 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4846 Defined to tell the NAND controller that the NAND chip is using
4848 Not all NAND drivers use this symbol.
4849 Example of drivers that use it:
4850 - drivers/mtd/nand/ndfc.c
4851 - drivers/mtd/nand/mxc_nand.c
4853 - CONFIG_SYS_NDFC_EBC0_CFG
4854 Sets the EBC0_CFG register for the NDFC. If not defined
4855 a default value will be used.
4858 Get DDR timing information from an I2C EEPROM. Common
4859 with pluggable memory modules such as SODIMMs
4862 I2C address of the SPD EEPROM
4864 - CONFIG_SYS_SPD_BUS_NUM
4865 If SPD EEPROM is on an I2C bus other than the first
4866 one, specify here. Note that the value must resolve
4867 to something your driver can deal with.
4869 - CONFIG_SYS_DDR_RAW_TIMING
4870 Get DDR timing information from other than SPD. Common with
4871 soldered DDR chips onboard without SPD. DDR raw timing
4872 parameters are extracted from datasheet and hard-coded into
4873 header files or board specific files.
4875 - CONFIG_FSL_DDR_INTERACTIVE
4876 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4878 - CONFIG_SYS_83XX_DDR_USES_CS0
4879 Only for 83xx systems. If specified, then DDR should
4880 be configured using CS0 and CS1 instead of CS2 and CS3.
4882 - CONFIG_ETHER_ON_FEC[12]
4883 Define to enable FEC[12] on a 8xx series processor.
4885 - CONFIG_FEC[12]_PHY
4886 Define to the hardcoded PHY address which corresponds
4887 to the given FEC; i. e.
4888 #define CONFIG_FEC1_PHY 4
4889 means that the PHY with address 4 is connected to FEC1
4891 When set to -1, means to probe for first available.
4893 - CONFIG_FEC[12]_PHY_NORXERR
4894 The PHY does not have a RXERR line (RMII only).
4895 (so program the FEC to ignore it).
4898 Enable RMII mode for all FECs.
4899 Note that this is a global option, we can't
4900 have one FEC in standard MII mode and another in RMII mode.
4902 - CONFIG_CRC32_VERIFY
4903 Add a verify option to the crc32 command.
4906 => crc32 -v <address> <count> <crc32>
4908 Where address/count indicate a memory area
4909 and crc32 is the correct crc32 which the
4913 Add the "loopw" memory command. This only takes effect if
4914 the memory commands are activated globally (CONFIG_CMD_MEM).
4917 Add the "mdc" and "mwc" memory commands. These are cyclic
4922 This command will print 4 bytes (10,11,12,13) each 500 ms.
4924 => mwc.l 100 12345678 10
4925 This command will write 12345678 to address 100 all 10 ms.
4927 This only takes effect if the memory commands are activated
4928 globally (CONFIG_CMD_MEM).
4930 - CONFIG_SKIP_LOWLEVEL_INIT
4931 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4932 low level initializations (like setting up the memory
4933 controller) are omitted and/or U-Boot does not
4934 relocate itself into RAM.
4936 Normally this variable MUST NOT be defined. The only
4937 exception is when U-Boot is loaded (to RAM) by some
4938 other boot loader or by a debugger which performs
4939 these initializations itself.
4942 Modifies the behaviour of start.S when compiling a loader
4943 that is executed before the actual U-Boot. E.g. when
4944 compiling a NAND SPL.
4947 Modifies the behaviour of start.S when compiling a loader
4948 that is executed after the SPL and before the actual U-Boot.
4949 It is loaded by the SPL.
4951 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4952 Only for 85xx systems. If this variable is specified, the section
4953 .resetvec is not kept and the section .bootpg is placed in the
4954 previous 4k of the .text section.
4956 - CONFIG_ARCH_MAP_SYSMEM
4957 Generally U-Boot (and in particular the md command) uses
4958 effective address. It is therefore not necessary to regard
4959 U-Boot address as virtual addresses that need to be translated
4960 to physical addresses. However, sandbox requires this, since
4961 it maintains its own little RAM buffer which contains all
4962 addressable memory. This option causes some memory accesses
4963 to be mapped through map_sysmem() / unmap_sysmem().
4965 - CONFIG_USE_ARCH_MEMCPY
4966 CONFIG_USE_ARCH_MEMSET
4967 If these options are used a optimized version of memcpy/memset will
4968 be used if available. These functions may be faster under some
4969 conditions but may increase the binary size.
4971 - CONFIG_X86_RESET_VECTOR
4972 If defined, the x86 reset vector code is included. This is not
4973 needed when U-Boot is running from Coreboot.
4976 Defines the MPU clock speed (in MHz).
4978 NOTE : currently only supported on AM335x platforms.
4980 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4981 Enables the RTC32K OSC on AM33xx based plattforms
4983 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4984 Option to disable subpage write in NAND driver
4985 driver that uses this:
4986 drivers/mtd/nand/davinci_nand.c
4988 Freescale QE/FMAN Firmware Support:
4989 -----------------------------------
4991 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4992 loading of "firmware", which is encoded in the QE firmware binary format.
4993 This firmware often needs to be loaded during U-Boot booting, so macros
4994 are used to identify the storage device (NOR flash, SPI, etc) and the address
4997 - CONFIG_SYS_FMAN_FW_ADDR
4998 The address in the storage device where the FMAN microcode is located. The
4999 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5002 - CONFIG_SYS_QE_FW_ADDR
5003 The address in the storage device where the QE microcode is located. The
5004 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5007 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5008 The maximum possible size of the firmware. The firmware binary format
5009 has a field that specifies the actual size of the firmware, but it
5010 might not be possible to read any part of the firmware unless some
5011 local storage is allocated to hold the entire firmware first.
5013 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5014 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5015 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5016 virtual address in NOR flash.
5018 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5019 Specifies that QE/FMAN firmware is located in NAND flash.
5020 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5022 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5023 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5024 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5026 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5027 Specifies that QE/FMAN firmware is located on the primary SPI
5028 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5030 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5031 Specifies that QE/FMAN firmware is located in the remote (master)
5032 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5033 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5034 window->master inbound window->master LAW->the ucode address in
5035 master's memory space.
5037 Freescale Layerscape Management Complex Firmware Support:
5038 ---------------------------------------------------------
5039 The Freescale Layerscape Management Complex (MC) supports the loading of
5041 This firmware often needs to be loaded during U-Boot booting, so macros
5042 are used to identify the storage device (NOR flash, SPI, etc) and the address
5045 - CONFIG_FSL_MC_ENET
5046 Enable the MC driver for Layerscape SoCs.
5048 - CONFIG_SYS_LS_MC_FW_ADDR
5049 The address in the storage device where the firmware is located. The
5050 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5053 - CONFIG_SYS_LS_MC_FW_LENGTH
5054 The maximum possible size of the firmware. The firmware binary format
5055 has a field that specifies the actual size of the firmware, but it
5056 might not be possible to read any part of the firmware unless some
5057 local storage is allocated to hold the entire firmware first.
5059 - CONFIG_SYS_LS_MC_FW_IN_NOR
5060 Specifies that MC firmware is located in NOR flash, mapped as
5061 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5062 virtual address in NOR flash.
5064 Building the Software:
5065 ======================
5067 Building U-Boot has been tested in several native build environments
5068 and in many different cross environments. Of course we cannot support
5069 all possibly existing versions of cross development tools in all
5070 (potentially obsolete) versions. In case of tool chain problems we
5071 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5072 which is extensively used to build and test U-Boot.
5074 If you are not using a native environment, it is assumed that you
5075 have GNU cross compiling tools available in your path. In this case,
5076 you must set the environment variable CROSS_COMPILE in your shell.
5077 Note that no changes to the Makefile or any other source files are
5078 necessary. For example using the ELDK on a 4xx CPU, please enter:
5080 $ CROSS_COMPILE=ppc_4xx-
5081 $ export CROSS_COMPILE
5083 Note: If you wish to generate Windows versions of the utilities in
5084 the tools directory you can use the MinGW toolchain
5085 (http://www.mingw.org). Set your HOST tools to the MinGW
5086 toolchain and execute 'make tools'. For example:
5088 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5090 Binaries such as tools/mkimage.exe will be created which can
5091 be executed on computers running Windows.
5093 U-Boot is intended to be simple to build. After installing the
5094 sources you must configure U-Boot for one specific board type. This
5099 where "NAME_defconfig" is the name of one of the existing configu-
5100 rations; see boards.cfg for supported names.
5102 Note: for some board special configuration names may exist; check if
5103 additional information is available from the board vendor; for
5104 instance, the TQM823L systems are available without (standard)
5105 or with LCD support. You can select such additional "features"
5106 when choosing the configuration, i. e.
5108 make TQM823L_defconfig
5109 - will configure for a plain TQM823L, i. e. no LCD support
5111 make TQM823L_LCD_defconfig
5112 - will configure for a TQM823L with U-Boot console on LCD
5117 Finally, type "make all", and you should get some working U-Boot
5118 images ready for download to / installation on your system:
5120 - "u-boot.bin" is a raw binary image
5121 - "u-boot" is an image in ELF binary format
5122 - "u-boot.srec" is in Motorola S-Record format
5124 By default the build is performed locally and the objects are saved
5125 in the source directory. One of the two methods can be used to change
5126 this behavior and build U-Boot to some external directory:
5128 1. Add O= to the make command line invocations:
5130 make O=/tmp/build distclean
5131 make O=/tmp/build NAME_defconfig
5132 make O=/tmp/build all
5134 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5136 export KBUILD_OUTPUT=/tmp/build
5141 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5145 Please be aware that the Makefiles assume you are using GNU make, so
5146 for instance on NetBSD you might need to use "gmake" instead of
5150 If the system board that you have is not listed, then you will need
5151 to port U-Boot to your hardware platform. To do this, follow these
5154 1. Add a new configuration option for your board to the toplevel
5155 "boards.cfg" file, using the existing entries as examples.
5156 Follow the instructions there to keep the boards in order.
5157 2. Create a new directory to hold your board specific code. Add any
5158 files you need. In your board directory, you will need at least
5159 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5160 3. Create a new configuration file "include/configs/<board>.h" for
5162 3. If you're porting U-Boot to a new CPU, then also create a new
5163 directory to hold your CPU specific code. Add any files you need.
5164 4. Run "make <board>_defconfig" with your new name.
5165 5. Type "make", and you should get a working "u-boot.srec" file
5166 to be installed on your target system.
5167 6. Debug and solve any problems that might arise.
5168 [Of course, this last step is much harder than it sounds.]
5171 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5172 ==============================================================
5174 If you have modified U-Boot sources (for instance added a new board
5175 or support for new devices, a new CPU, etc.) you are expected to
5176 provide feedback to the other developers. The feedback normally takes
5177 the form of a "patch", i. e. a context diff against a certain (latest
5178 official or latest in the git repository) version of U-Boot sources.
5180 But before you submit such a patch, please verify that your modifi-
5181 cation did not break existing code. At least make sure that *ALL* of
5182 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5183 just run the "MAKEALL" script, which will configure and build U-Boot
5184 for ALL supported system. Be warned, this will take a while. You can
5185 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5186 environment variable to the script, i. e. to use the ELDK cross tools
5189 CROSS_COMPILE=ppc_8xx- MAKEALL
5191 or to build on a native PowerPC system you can type
5193 CROSS_COMPILE=' ' MAKEALL
5195 When using the MAKEALL script, the default behaviour is to build
5196 U-Boot in the source directory. This location can be changed by
5197 setting the BUILD_DIR environment variable. Also, for each target
5198 built, the MAKEALL script saves two log files (<target>.ERR and
5199 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5200 location can be changed by setting the MAKEALL_LOGDIR environment
5201 variable. For example:
5203 export BUILD_DIR=/tmp/build
5204 export MAKEALL_LOGDIR=/tmp/log
5205 CROSS_COMPILE=ppc_8xx- MAKEALL
5207 With the above settings build objects are saved in the /tmp/build,
5208 log files are saved in the /tmp/log and the source tree remains clean
5209 during the whole build process.
5212 See also "U-Boot Porting Guide" below.
5215 Monitor Commands - Overview:
5216 ============================
5218 go - start application at address 'addr'
5219 run - run commands in an environment variable
5220 bootm - boot application image from memory
5221 bootp - boot image via network using BootP/TFTP protocol
5222 bootz - boot zImage from memory
5223 tftpboot- boot image via network using TFTP protocol
5224 and env variables "ipaddr" and "serverip"
5225 (and eventually "gatewayip")
5226 tftpput - upload a file via network using TFTP protocol
5227 rarpboot- boot image via network using RARP/TFTP protocol
5228 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5229 loads - load S-Record file over serial line
5230 loadb - load binary file over serial line (kermit mode)
5232 mm - memory modify (auto-incrementing)
5233 nm - memory modify (constant address)
5234 mw - memory write (fill)
5236 cmp - memory compare
5237 crc32 - checksum calculation
5238 i2c - I2C sub-system
5239 sspi - SPI utility commands
5240 base - print or set address offset
5241 printenv- print environment variables
5242 setenv - set environment variables
5243 saveenv - save environment variables to persistent storage
5244 protect - enable or disable FLASH write protection
5245 erase - erase FLASH memory
5246 flinfo - print FLASH memory information
5247 nand - NAND memory operations (see doc/README.nand)
5248 bdinfo - print Board Info structure
5249 iminfo - print header information for application image
5250 coninfo - print console devices and informations
5251 ide - IDE sub-system
5252 loop - infinite loop on address range
5253 loopw - infinite write loop on address range
5254 mtest - simple RAM test
5255 icache - enable or disable instruction cache
5256 dcache - enable or disable data cache
5257 reset - Perform RESET of the CPU
5258 echo - echo args to console
5259 version - print monitor version
5260 help - print online help
5261 ? - alias for 'help'
5264 Monitor Commands - Detailed Description:
5265 ========================================
5269 For now: just type "help <command>".
5272 Environment Variables:
5273 ======================
5275 U-Boot supports user configuration using Environment Variables which
5276 can be made persistent by saving to Flash memory.
5278 Environment Variables are set using "setenv", printed using
5279 "printenv", and saved to Flash using "saveenv". Using "setenv"
5280 without a value can be used to delete a variable from the
5281 environment. As long as you don't save the environment you are
5282 working with an in-memory copy. In case the Flash area containing the
5283 environment is erased by accident, a default environment is provided.
5285 Some configuration options can be set using Environment Variables.
5287 List of environment variables (most likely not complete):
5289 baudrate - see CONFIG_BAUDRATE
5291 bootdelay - see CONFIG_BOOTDELAY
5293 bootcmd - see CONFIG_BOOTCOMMAND
5295 bootargs - Boot arguments when booting an RTOS image
5297 bootfile - Name of the image to load with TFTP
5299 bootm_low - Memory range available for image processing in the bootm
5300 command can be restricted. This variable is given as
5301 a hexadecimal number and defines lowest address allowed
5302 for use by the bootm command. See also "bootm_size"
5303 environment variable. Address defined by "bootm_low" is
5304 also the base of the initial memory mapping for the Linux
5305 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5308 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5309 This variable is given as a hexadecimal number and it
5310 defines the size of the memory region starting at base
5311 address bootm_low that is accessible by the Linux kernel
5312 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5313 as the default value if it is defined, and bootm_size is
5316 bootm_size - Memory range available for image processing in the bootm
5317 command can be restricted. This variable is given as
5318 a hexadecimal number and defines the size of the region
5319 allowed for use by the bootm command. See also "bootm_low"
5320 environment variable.
5322 updatefile - Location of the software update file on a TFTP server, used
5323 by the automatic software update feature. Please refer to
5324 documentation in doc/README.update for more details.
5326 autoload - if set to "no" (any string beginning with 'n'),
5327 "bootp" will just load perform a lookup of the
5328 configuration from the BOOTP server, but not try to
5329 load any image using TFTP
5331 autostart - if set to "yes", an image loaded using the "bootp",
5332 "rarpboot", "tftpboot" or "diskboot" commands will
5333 be automatically started (by internally calling
5336 If set to "no", a standalone image passed to the
5337 "bootm" command will be copied to the load address
5338 (and eventually uncompressed), but NOT be started.
5339 This can be used to load and uncompress arbitrary
5342 fdt_high - if set this restricts the maximum address that the
5343 flattened device tree will be copied into upon boot.
5344 For example, if you have a system with 1 GB memory
5345 at physical address 0x10000000, while Linux kernel
5346 only recognizes the first 704 MB as low memory, you
5347 may need to set fdt_high as 0x3C000000 to have the
5348 device tree blob be copied to the maximum address
5349 of the 704 MB low memory, so that Linux kernel can
5350 access it during the boot procedure.
5352 If this is set to the special value 0xFFFFFFFF then
5353 the fdt will not be copied at all on boot. For this
5354 to work it must reside in writable memory, have
5355 sufficient padding on the end of it for u-boot to
5356 add the information it needs into it, and the memory
5357 must be accessible by the kernel.
5359 fdtcontroladdr- if set this is the address of the control flattened
5360 device tree used by U-Boot when CONFIG_OF_CONTROL is
5363 i2cfast - (PPC405GP|PPC405EP only)
5364 if set to 'y' configures Linux I2C driver for fast
5365 mode (400kHZ). This environment variable is used in
5366 initialization code. So, for changes to be effective
5367 it must be saved and board must be reset.
5369 initrd_high - restrict positioning of initrd images:
5370 If this variable is not set, initrd images will be
5371 copied to the highest possible address in RAM; this
5372 is usually what you want since it allows for
5373 maximum initrd size. If for some reason you want to
5374 make sure that the initrd image is loaded below the
5375 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5376 variable to a value of "no" or "off" or "0".
5377 Alternatively, you can set it to a maximum upper
5378 address to use (U-Boot will still check that it
5379 does not overwrite the U-Boot stack and data).
5381 For instance, when you have a system with 16 MB
5382 RAM, and want to reserve 4 MB from use by Linux,
5383 you can do this by adding "mem=12M" to the value of
5384 the "bootargs" variable. However, now you must make
5385 sure that the initrd image is placed in the first
5386 12 MB as well - this can be done with
5388 setenv initrd_high 00c00000
5390 If you set initrd_high to 0xFFFFFFFF, this is an
5391 indication to U-Boot that all addresses are legal
5392 for the Linux kernel, including addresses in flash
5393 memory. In this case U-Boot will NOT COPY the
5394 ramdisk at all. This may be useful to reduce the
5395 boot time on your system, but requires that this
5396 feature is supported by your Linux kernel.
5398 ipaddr - IP address; needed for tftpboot command
5400 loadaddr - Default load address for commands like "bootp",
5401 "rarpboot", "tftpboot", "loadb" or "diskboot"
5403 loads_echo - see CONFIG_LOADS_ECHO
5405 serverip - TFTP server IP address; needed for tftpboot command
5407 bootretry - see CONFIG_BOOT_RETRY_TIME
5409 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5411 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5413 ethprime - controls which interface is used first.
5415 ethact - controls which interface is currently active.
5416 For example you can do the following
5418 => setenv ethact FEC
5419 => ping 192.168.0.1 # traffic sent on FEC
5420 => setenv ethact SCC
5421 => ping 10.0.0.1 # traffic sent on SCC
5423 ethrotate - When set to "no" U-Boot does not go through all
5424 available network interfaces.
5425 It just stays at the currently selected interface.
5427 netretry - When set to "no" each network operation will
5428 either succeed or fail without retrying.
5429 When set to "once" the network operation will
5430 fail when all the available network interfaces
5431 are tried once without success.
5432 Useful on scripts which control the retry operation
5435 npe_ucode - set load address for the NPE microcode
5437 silent_linux - If set then linux will be told to boot silently, by
5438 changing the console to be empty. If "yes" it will be
5439 made silent. If "no" it will not be made silent. If
5440 unset, then it will be made silent if the U-Boot console
5443 tftpsrcport - If this is set, the value is used for TFTP's
5446 tftpdstport - If this is set, the value is used for TFTP's UDP
5447 destination port instead of the Well Know Port 69.
5449 tftpblocksize - Block size to use for TFTP transfers; if not set,
5450 we use the TFTP server's default block size
5452 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5453 seconds, minimum value is 1000 = 1 second). Defines
5454 when a packet is considered to be lost so it has to
5455 be retransmitted. The default is 5000 = 5 seconds.
5456 Lowering this value may make downloads succeed
5457 faster in networks with high packet loss rates or
5458 with unreliable TFTP servers.
5460 vlan - When set to a value < 4095 the traffic over
5461 Ethernet is encapsulated/received over 802.1q
5464 The following image location variables contain the location of images
5465 used in booting. The "Image" column gives the role of the image and is
5466 not an environment variable name. The other columns are environment
5467 variable names. "File Name" gives the name of the file on a TFTP
5468 server, "RAM Address" gives the location in RAM the image will be
5469 loaded to, and "Flash Location" gives the image's address in NOR
5470 flash or offset in NAND flash.
5472 *Note* - these variables don't have to be defined for all boards, some
5473 boards currenlty use other variables for these purposes, and some
5474 boards use these variables for other purposes.
5476 Image File Name RAM Address Flash Location
5477 ----- --------- ----------- --------------
5478 u-boot u-boot u-boot_addr_r u-boot_addr
5479 Linux kernel bootfile kernel_addr_r kernel_addr
5480 device tree blob fdtfile fdt_addr_r fdt_addr
5481 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5483 The following environment variables may be used and automatically
5484 updated by the network boot commands ("bootp" and "rarpboot"),
5485 depending the information provided by your boot server:
5487 bootfile - see above
5488 dnsip - IP address of your Domain Name Server
5489 dnsip2 - IP address of your secondary Domain Name Server
5490 gatewayip - IP address of the Gateway (Router) to use
5491 hostname - Target hostname
5493 netmask - Subnet Mask
5494 rootpath - Pathname of the root filesystem on the NFS server
5495 serverip - see above
5498 There are two special Environment Variables:
5500 serial# - contains hardware identification information such
5501 as type string and/or serial number
5502 ethaddr - Ethernet address
5504 These variables can be set only once (usually during manufacturing of
5505 the board). U-Boot refuses to delete or overwrite these variables
5506 once they have been set once.
5509 Further special Environment Variables:
5511 ver - Contains the U-Boot version string as printed
5512 with the "version" command. This variable is
5513 readonly (see CONFIG_VERSION_VARIABLE).
5516 Please note that changes to some configuration parameters may take
5517 only effect after the next boot (yes, that's just like Windoze :-).
5520 Callback functions for environment variables:
5521 ---------------------------------------------
5523 For some environment variables, the behavior of u-boot needs to change
5524 when their values are changed. This functionailty allows functions to
5525 be associated with arbitrary variables. On creation, overwrite, or
5526 deletion, the callback will provide the opportunity for some side
5527 effect to happen or for the change to be rejected.
5529 The callbacks are named and associated with a function using the
5530 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5532 These callbacks are associated with variables in one of two ways. The
5533 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5534 in the board configuration to a string that defines a list of
5535 associations. The list must be in the following format:
5537 entry = variable_name[:callback_name]
5540 If the callback name is not specified, then the callback is deleted.
5541 Spaces are also allowed anywhere in the list.
5543 Callbacks can also be associated by defining the ".callbacks" variable
5544 with the same list format above. Any association in ".callbacks" will
5545 override any association in the static list. You can define
5546 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5547 ".callbacks" envirnoment variable in the default or embedded environment.
5550 Command Line Parsing:
5551 =====================
5553 There are two different command line parsers available with U-Boot:
5554 the old "simple" one, and the much more powerful "hush" shell:
5556 Old, simple command line parser:
5557 --------------------------------
5559 - supports environment variables (through setenv / saveenv commands)
5560 - several commands on one line, separated by ';'
5561 - variable substitution using "... ${name} ..." syntax
5562 - special characters ('$', ';') can be escaped by prefixing with '\',
5564 setenv bootcmd bootm \${address}
5565 - You can also escape text by enclosing in single apostrophes, for example:
5566 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5571 - similar to Bourne shell, with control structures like
5572 if...then...else...fi, for...do...done; while...do...done,
5573 until...do...done, ...
5574 - supports environment ("global") variables (through setenv / saveenv
5575 commands) and local shell variables (through standard shell syntax
5576 "name=value"); only environment variables can be used with "run"
5582 (1) If a command line (or an environment variable executed by a "run"
5583 command) contains several commands separated by semicolon, and
5584 one of these commands fails, then the remaining commands will be
5587 (2) If you execute several variables with one call to run (i. e.
5588 calling run with a list of variables as arguments), any failing
5589 command will cause "run" to terminate, i. e. the remaining
5590 variables are not executed.
5592 Note for Redundant Ethernet Interfaces:
5593 =======================================
5595 Some boards come with redundant Ethernet interfaces; U-Boot supports
5596 such configurations and is capable of automatic selection of a
5597 "working" interface when needed. MAC assignment works as follows:
5599 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5600 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5601 "eth1addr" (=>eth1), "eth2addr", ...
5603 If the network interface stores some valid MAC address (for instance
5604 in SROM), this is used as default address if there is NO correspon-
5605 ding setting in the environment; if the corresponding environment
5606 variable is set, this overrides the settings in the card; that means:
5608 o If the SROM has a valid MAC address, and there is no address in the
5609 environment, the SROM's address is used.
5611 o If there is no valid address in the SROM, and a definition in the
5612 environment exists, then the value from the environment variable is
5615 o If both the SROM and the environment contain a MAC address, and
5616 both addresses are the same, this MAC address is used.
5618 o If both the SROM and the environment contain a MAC address, and the
5619 addresses differ, the value from the environment is used and a
5622 o If neither SROM nor the environment contain a MAC address, an error
5625 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5626 will be programmed into hardware as part of the initialization process. This
5627 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5628 The naming convention is as follows:
5629 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5634 U-Boot is capable of booting (and performing other auxiliary operations on)
5635 images in two formats:
5637 New uImage format (FIT)
5638 -----------------------
5640 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5641 to Flattened Device Tree). It allows the use of images with multiple
5642 components (several kernels, ramdisks, etc.), with contents protected by
5643 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5649 Old image format is based on binary files which can be basically anything,
5650 preceded by a special header; see the definitions in include/image.h for
5651 details; basically, the header defines the following image properties:
5653 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5654 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5655 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5656 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5658 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5659 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5660 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5661 * Compression Type (uncompressed, gzip, bzip2)
5667 The header is marked by a special Magic Number, and both the header
5668 and the data portions of the image are secured against corruption by
5675 Although U-Boot should support any OS or standalone application
5676 easily, the main focus has always been on Linux during the design of
5679 U-Boot includes many features that so far have been part of some
5680 special "boot loader" code within the Linux kernel. Also, any
5681 "initrd" images to be used are no longer part of one big Linux image;
5682 instead, kernel and "initrd" are separate images. This implementation
5683 serves several purposes:
5685 - the same features can be used for other OS or standalone
5686 applications (for instance: using compressed images to reduce the
5687 Flash memory footprint)
5689 - it becomes much easier to port new Linux kernel versions because
5690 lots of low-level, hardware dependent stuff are done by U-Boot
5692 - the same Linux kernel image can now be used with different "initrd"
5693 images; of course this also means that different kernel images can
5694 be run with the same "initrd". This makes testing easier (you don't
5695 have to build a new "zImage.initrd" Linux image when you just
5696 change a file in your "initrd"). Also, a field-upgrade of the
5697 software is easier now.
5703 Porting Linux to U-Boot based systems:
5704 ---------------------------------------
5706 U-Boot cannot save you from doing all the necessary modifications to
5707 configure the Linux device drivers for use with your target hardware
5708 (no, we don't intend to provide a full virtual machine interface to
5711 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5713 Just make sure your machine specific header file (for instance
5714 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5715 Information structure as we define in include/asm-<arch>/u-boot.h,
5716 and make sure that your definition of IMAP_ADDR uses the same value
5717 as your U-Boot configuration in CONFIG_SYS_IMMR.
5719 Note that U-Boot now has a driver model, a unified model for drivers.
5720 If you are adding a new driver, plumb it into driver model. If there
5721 is no uclass available, you are encouraged to create one. See
5725 Configuring the Linux kernel:
5726 -----------------------------
5728 No specific requirements for U-Boot. Make sure you have some root
5729 device (initial ramdisk, NFS) for your target system.
5732 Building a Linux Image:
5733 -----------------------
5735 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5736 not used. If you use recent kernel source, a new build target
5737 "uImage" will exist which automatically builds an image usable by
5738 U-Boot. Most older kernels also have support for a "pImage" target,
5739 which was introduced for our predecessor project PPCBoot and uses a
5740 100% compatible format.
5744 make TQM850L_defconfig
5749 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5750 encapsulate a compressed Linux kernel image with header information,
5751 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5753 * build a standard "vmlinux" kernel image (in ELF binary format):
5755 * convert the kernel into a raw binary image:
5757 ${CROSS_COMPILE}-objcopy -O binary \
5758 -R .note -R .comment \
5759 -S vmlinux linux.bin
5761 * compress the binary image:
5765 * package compressed binary image for U-Boot:
5767 mkimage -A ppc -O linux -T kernel -C gzip \
5768 -a 0 -e 0 -n "Linux Kernel Image" \
5769 -d linux.bin.gz uImage
5772 The "mkimage" tool can also be used to create ramdisk images for use
5773 with U-Boot, either separated from the Linux kernel image, or
5774 combined into one file. "mkimage" encapsulates the images with a 64
5775 byte header containing information about target architecture,
5776 operating system, image type, compression method, entry points, time
5777 stamp, CRC32 checksums, etc.
5779 "mkimage" can be called in two ways: to verify existing images and
5780 print the header information, or to build new images.
5782 In the first form (with "-l" option) mkimage lists the information
5783 contained in the header of an existing U-Boot image; this includes
5784 checksum verification:
5786 tools/mkimage -l image
5787 -l ==> list image header information
5789 The second form (with "-d" option) is used to build a U-Boot image
5790 from a "data file" which is used as image payload:
5792 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5793 -n name -d data_file image
5794 -A ==> set architecture to 'arch'
5795 -O ==> set operating system to 'os'
5796 -T ==> set image type to 'type'
5797 -C ==> set compression type 'comp'
5798 -a ==> set load address to 'addr' (hex)
5799 -e ==> set entry point to 'ep' (hex)
5800 -n ==> set image name to 'name'
5801 -d ==> use image data from 'datafile'
5803 Right now, all Linux kernels for PowerPC systems use the same load
5804 address (0x00000000), but the entry point address depends on the
5807 - 2.2.x kernels have the entry point at 0x0000000C,
5808 - 2.3.x and later kernels have the entry point at 0x00000000.
5810 So a typical call to build a U-Boot image would read:
5812 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5813 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5814 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5815 > examples/uImage.TQM850L
5816 Image Name: 2.4.4 kernel for TQM850L
5817 Created: Wed Jul 19 02:34:59 2000
5818 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5819 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5820 Load Address: 0x00000000
5821 Entry Point: 0x00000000
5823 To verify the contents of the image (or check for corruption):
5825 -> tools/mkimage -l examples/uImage.TQM850L
5826 Image Name: 2.4.4 kernel for TQM850L
5827 Created: Wed Jul 19 02:34:59 2000
5828 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5829 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5830 Load Address: 0x00000000
5831 Entry Point: 0x00000000
5833 NOTE: for embedded systems where boot time is critical you can trade
5834 speed for memory and install an UNCOMPRESSED image instead: this
5835 needs more space in Flash, but boots much faster since it does not
5836 need to be uncompressed:
5838 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5839 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5840 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5841 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5842 > examples/uImage.TQM850L-uncompressed
5843 Image Name: 2.4.4 kernel for TQM850L
5844 Created: Wed Jul 19 02:34:59 2000
5845 Image Type: PowerPC Linux Kernel Image (uncompressed)
5846 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5847 Load Address: 0x00000000
5848 Entry Point: 0x00000000
5851 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5852 when your kernel is intended to use an initial ramdisk:
5854 -> tools/mkimage -n 'Simple Ramdisk Image' \
5855 > -A ppc -O linux -T ramdisk -C gzip \
5856 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5857 Image Name: Simple Ramdisk Image
5858 Created: Wed Jan 12 14:01:50 2000
5859 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5860 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5861 Load Address: 0x00000000
5862 Entry Point: 0x00000000
5864 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5865 option performs the converse operation of the mkimage's second form (the "-d"
5866 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5869 tools/dumpimage -i image -p position data_file
5870 -i ==> extract from the 'image' a specific 'data_file', \
5871 indexed by 'position'
5874 Installing a Linux Image:
5875 -------------------------
5877 To downloading a U-Boot image over the serial (console) interface,
5878 you must convert the image to S-Record format:
5880 objcopy -I binary -O srec examples/image examples/image.srec
5882 The 'objcopy' does not understand the information in the U-Boot
5883 image header, so the resulting S-Record file will be relative to
5884 address 0x00000000. To load it to a given address, you need to
5885 specify the target address as 'offset' parameter with the 'loads'
5888 Example: install the image to address 0x40100000 (which on the
5889 TQM8xxL is in the first Flash bank):
5891 => erase 40100000 401FFFFF
5897 ## Ready for S-Record download ...
5898 ~>examples/image.srec
5899 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5901 15989 15990 15991 15992
5902 [file transfer complete]
5904 ## Start Addr = 0x00000000
5907 You can check the success of the download using the 'iminfo' command;
5908 this includes a checksum verification so you can be sure no data
5909 corruption happened:
5913 ## Checking Image at 40100000 ...
5914 Image Name: 2.2.13 for initrd on TQM850L
5915 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5916 Data Size: 335725 Bytes = 327 kB = 0 MB
5917 Load Address: 00000000
5918 Entry Point: 0000000c
5919 Verifying Checksum ... OK
5925 The "bootm" command is used to boot an application that is stored in
5926 memory (RAM or Flash). In case of a Linux kernel image, the contents
5927 of the "bootargs" environment variable is passed to the kernel as
5928 parameters. You can check and modify this variable using the
5929 "printenv" and "setenv" commands:
5932 => printenv bootargs
5933 bootargs=root=/dev/ram
5935 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5937 => printenv bootargs
5938 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5941 ## Booting Linux kernel at 40020000 ...
5942 Image Name: 2.2.13 for NFS on TQM850L
5943 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5944 Data Size: 381681 Bytes = 372 kB = 0 MB
5945 Load Address: 00000000
5946 Entry Point: 0000000c
5947 Verifying Checksum ... OK
5948 Uncompressing Kernel Image ... OK
5949 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
5950 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5951 time_init: decrementer frequency = 187500000/60
5952 Calibrating delay loop... 49.77 BogoMIPS
5953 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5956 If you want to boot a Linux kernel with initial RAM disk, you pass
5957 the memory addresses of both the kernel and the initrd image (PPBCOOT
5958 format!) to the "bootm" command:
5960 => imi 40100000 40200000
5962 ## Checking Image at 40100000 ...
5963 Image Name: 2.2.13 for initrd on TQM850L
5964 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5965 Data Size: 335725 Bytes = 327 kB = 0 MB
5966 Load Address: 00000000
5967 Entry Point: 0000000c
5968 Verifying Checksum ... OK
5970 ## Checking Image at 40200000 ...
5971 Image Name: Simple Ramdisk Image
5972 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5973 Data Size: 566530 Bytes = 553 kB = 0 MB
5974 Load Address: 00000000
5975 Entry Point: 00000000
5976 Verifying Checksum ... OK
5978 => bootm 40100000 40200000
5979 ## Booting Linux kernel at 40100000 ...
5980 Image Name: 2.2.13 for initrd on TQM850L
5981 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5982 Data Size: 335725 Bytes = 327 kB = 0 MB
5983 Load Address: 00000000
5984 Entry Point: 0000000c
5985 Verifying Checksum ... OK
5986 Uncompressing Kernel Image ... OK
5987 ## Loading RAMDisk Image at 40200000 ...
5988 Image Name: Simple Ramdisk Image
5989 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5990 Data Size: 566530 Bytes = 553 kB = 0 MB
5991 Load Address: 00000000
5992 Entry Point: 00000000
5993 Verifying Checksum ... OK
5994 Loading Ramdisk ... OK
5995 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
5996 Boot arguments: root=/dev/ram
5997 time_init: decrementer frequency = 187500000/60
5998 Calibrating delay loop... 49.77 BogoMIPS
6000 RAMDISK: Compressed image found at block 0
6001 VFS: Mounted root (ext2 filesystem).
6005 Boot Linux and pass a flat device tree:
6008 First, U-Boot must be compiled with the appropriate defines. See the section
6009 titled "Linux Kernel Interface" above for a more in depth explanation. The
6010 following is an example of how to start a kernel and pass an updated
6016 oft=oftrees/mpc8540ads.dtb
6017 => tftp $oftaddr $oft
6018 Speed: 1000, full duplex
6020 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6021 Filename 'oftrees/mpc8540ads.dtb'.
6022 Load address: 0x300000
6025 Bytes transferred = 4106 (100a hex)
6026 => tftp $loadaddr $bootfile
6027 Speed: 1000, full duplex
6029 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6031 Load address: 0x200000
6032 Loading:############
6034 Bytes transferred = 1029407 (fb51f hex)
6039 => bootm $loadaddr - $oftaddr
6040 ## Booting image at 00200000 ...
6041 Image Name: Linux-2.6.17-dirty
6042 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6043 Data Size: 1029343 Bytes = 1005.2 kB
6044 Load Address: 00000000
6045 Entry Point: 00000000
6046 Verifying Checksum ... OK
6047 Uncompressing Kernel Image ... OK
6048 Booting using flat device tree at 0x300000
6049 Using MPC85xx ADS machine description
6050 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6054 More About U-Boot Image Types:
6055 ------------------------------
6057 U-Boot supports the following image types:
6059 "Standalone Programs" are directly runnable in the environment
6060 provided by U-Boot; it is expected that (if they behave
6061 well) you can continue to work in U-Boot after return from
6062 the Standalone Program.
6063 "OS Kernel Images" are usually images of some Embedded OS which
6064 will take over control completely. Usually these programs
6065 will install their own set of exception handlers, device
6066 drivers, set up the MMU, etc. - this means, that you cannot
6067 expect to re-enter U-Boot except by resetting the CPU.
6068 "RAMDisk Images" are more or less just data blocks, and their
6069 parameters (address, size) are passed to an OS kernel that is
6071 "Multi-File Images" contain several images, typically an OS
6072 (Linux) kernel image and one or more data images like
6073 RAMDisks. This construct is useful for instance when you want
6074 to boot over the network using BOOTP etc., where the boot
6075 server provides just a single image file, but you want to get
6076 for instance an OS kernel and a RAMDisk image.
6078 "Multi-File Images" start with a list of image sizes, each
6079 image size (in bytes) specified by an "uint32_t" in network
6080 byte order. This list is terminated by an "(uint32_t)0".
6081 Immediately after the terminating 0 follow the images, one by
6082 one, all aligned on "uint32_t" boundaries (size rounded up to
6083 a multiple of 4 bytes).
6085 "Firmware Images" are binary images containing firmware (like
6086 U-Boot or FPGA images) which usually will be programmed to
6089 "Script files" are command sequences that will be executed by
6090 U-Boot's command interpreter; this feature is especially
6091 useful when you configure U-Boot to use a real shell (hush)
6092 as command interpreter.
6094 Booting the Linux zImage:
6095 -------------------------
6097 On some platforms, it's possible to boot Linux zImage. This is done
6098 using the "bootz" command. The syntax of "bootz" command is the same
6099 as the syntax of "bootm" command.
6101 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6102 kernel with raw initrd images. The syntax is slightly different, the
6103 address of the initrd must be augmented by it's size, in the following
6104 format: "<initrd addres>:<initrd size>".
6110 One of the features of U-Boot is that you can dynamically load and
6111 run "standalone" applications, which can use some resources of
6112 U-Boot like console I/O functions or interrupt services.
6114 Two simple examples are included with the sources:
6119 'examples/hello_world.c' contains a small "Hello World" Demo
6120 application; it is automatically compiled when you build U-Boot.
6121 It's configured to run at address 0x00040004, so you can play with it
6125 ## Ready for S-Record download ...
6126 ~>examples/hello_world.srec
6127 1 2 3 4 5 6 7 8 9 10 11 ...
6128 [file transfer complete]
6130 ## Start Addr = 0x00040004
6132 => go 40004 Hello World! This is a test.
6133 ## Starting application at 0x00040004 ...
6144 Hit any key to exit ...
6146 ## Application terminated, rc = 0x0
6148 Another example, which demonstrates how to register a CPM interrupt
6149 handler with the U-Boot code, can be found in 'examples/timer.c'.
6150 Here, a CPM timer is set up to generate an interrupt every second.
6151 The interrupt service routine is trivial, just printing a '.'
6152 character, but this is just a demo program. The application can be
6153 controlled by the following keys:
6155 ? - print current values og the CPM Timer registers
6156 b - enable interrupts and start timer
6157 e - stop timer and disable interrupts
6158 q - quit application
6161 ## Ready for S-Record download ...
6162 ~>examples/timer.srec
6163 1 2 3 4 5 6 7 8 9 10 11 ...
6164 [file transfer complete]
6166 ## Start Addr = 0x00040004
6169 ## Starting application at 0x00040004 ...
6172 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6175 [q, b, e, ?] Set interval 1000000 us
6178 [q, b, e, ?] ........
6179 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6182 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6185 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6188 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6190 [q, b, e, ?] ...Stopping timer
6192 [q, b, e, ?] ## Application terminated, rc = 0x0
6198 Over time, many people have reported problems when trying to use the
6199 "minicom" terminal emulation program for serial download. I (wd)
6200 consider minicom to be broken, and recommend not to use it. Under
6201 Unix, I recommend to use C-Kermit for general purpose use (and
6202 especially for kermit binary protocol download ("loadb" command), and
6203 use "cu" for S-Record download ("loads" command). See
6204 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6205 for help with kermit.
6208 Nevertheless, if you absolutely want to use it try adding this
6209 configuration to your "File transfer protocols" section:
6211 Name Program Name U/D FullScr IO-Red. Multi
6212 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6213 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6219 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6220 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6222 Building requires a cross environment; it is known to work on
6223 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6224 need gmake since the Makefiles are not compatible with BSD make).
6225 Note that the cross-powerpc package does not install include files;
6226 attempting to build U-Boot will fail because <machine/ansi.h> is
6227 missing. This file has to be installed and patched manually:
6229 # cd /usr/pkg/cross/powerpc-netbsd/include
6231 # ln -s powerpc machine
6232 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6233 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6235 Native builds *don't* work due to incompatibilities between native
6236 and U-Boot include files.
6238 Booting assumes that (the first part of) the image booted is a
6239 stage-2 loader which in turn loads and then invokes the kernel
6240 proper. Loader sources will eventually appear in the NetBSD source
6241 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6242 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6245 Implementation Internals:
6246 =========================
6248 The following is not intended to be a complete description of every
6249 implementation detail. However, it should help to understand the
6250 inner workings of U-Boot and make it easier to port it to custom
6254 Initial Stack, Global Data:
6255 ---------------------------
6257 The implementation of U-Boot is complicated by the fact that U-Boot
6258 starts running out of ROM (flash memory), usually without access to
6259 system RAM (because the memory controller is not initialized yet).
6260 This means that we don't have writable Data or BSS segments, and BSS
6261 is not initialized as zero. To be able to get a C environment working
6262 at all, we have to allocate at least a minimal stack. Implementation
6263 options for this are defined and restricted by the CPU used: Some CPU
6264 models provide on-chip memory (like the IMMR area on MPC8xx and
6265 MPC826x processors), on others (parts of) the data cache can be
6266 locked as (mis-) used as memory, etc.
6268 Chris Hallinan posted a good summary of these issues to the
6269 U-Boot mailing list:
6271 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6272 From: "Chris Hallinan" <clh@net1plus.com>
6273 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6276 Correct me if I'm wrong, folks, but the way I understand it
6277 is this: Using DCACHE as initial RAM for Stack, etc, does not
6278 require any physical RAM backing up the cache. The cleverness
6279 is that the cache is being used as a temporary supply of
6280 necessary storage before the SDRAM controller is setup. It's
6281 beyond the scope of this list to explain the details, but you
6282 can see how this works by studying the cache architecture and
6283 operation in the architecture and processor-specific manuals.
6285 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6286 is another option for the system designer to use as an
6287 initial stack/RAM area prior to SDRAM being available. Either
6288 option should work for you. Using CS 4 should be fine if your
6289 board designers haven't used it for something that would
6290 cause you grief during the initial boot! It is frequently not
6293 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6294 with your processor/board/system design. The default value
6295 you will find in any recent u-boot distribution in
6296 walnut.h should work for you. I'd set it to a value larger
6297 than your SDRAM module. If you have a 64MB SDRAM module, set
6298 it above 400_0000. Just make sure your board has no resources
6299 that are supposed to respond to that address! That code in
6300 start.S has been around a while and should work as is when
6301 you get the config right.
6306 It is essential to remember this, since it has some impact on the C
6307 code for the initialization procedures:
6309 * Initialized global data (data segment) is read-only. Do not attempt
6312 * Do not use any uninitialized global data (or implicitely initialized
6313 as zero data - BSS segment) at all - this is undefined, initiali-
6314 zation is performed later (when relocating to RAM).
6316 * Stack space is very limited. Avoid big data buffers or things like
6319 Having only the stack as writable memory limits means we cannot use
6320 normal global data to share information beween the code. But it
6321 turned out that the implementation of U-Boot can be greatly
6322 simplified by making a global data structure (gd_t) available to all
6323 functions. We could pass a pointer to this data as argument to _all_
6324 functions, but this would bloat the code. Instead we use a feature of
6325 the GCC compiler (Global Register Variables) to share the data: we
6326 place a pointer (gd) to the global data into a register which we
6327 reserve for this purpose.
6329 When choosing a register for such a purpose we are restricted by the
6330 relevant (E)ABI specifications for the current architecture, and by
6331 GCC's implementation.
6333 For PowerPC, the following registers have specific use:
6335 R2: reserved for system use
6336 R3-R4: parameter passing and return values
6337 R5-R10: parameter passing
6338 R13: small data area pointer
6342 (U-Boot also uses R12 as internal GOT pointer. r12
6343 is a volatile register so r12 needs to be reset when
6344 going back and forth between asm and C)
6346 ==> U-Boot will use R2 to hold a pointer to the global data
6348 Note: on PPC, we could use a static initializer (since the
6349 address of the global data structure is known at compile time),
6350 but it turned out that reserving a register results in somewhat
6351 smaller code - although the code savings are not that big (on
6352 average for all boards 752 bytes for the whole U-Boot image,
6353 624 text + 127 data).
6355 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6356 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6358 ==> U-Boot will use P3 to hold a pointer to the global data
6360 On ARM, the following registers are used:
6362 R0: function argument word/integer result
6363 R1-R3: function argument word
6364 R9: platform specific
6365 R10: stack limit (used only if stack checking is enabled)
6366 R11: argument (frame) pointer
6367 R12: temporary workspace
6370 R15: program counter
6372 ==> U-Boot will use R9 to hold a pointer to the global data
6374 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6376 On Nios II, the ABI is documented here:
6377 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6379 ==> U-Boot will use gp to hold a pointer to the global data
6381 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6382 to access small data sections, so gp is free.
6384 On NDS32, the following registers are used:
6386 R0-R1: argument/return
6388 R15: temporary register for assembler
6389 R16: trampoline register
6390 R28: frame pointer (FP)
6391 R29: global pointer (GP)
6392 R30: link register (LP)
6393 R31: stack pointer (SP)
6394 PC: program counter (PC)
6396 ==> U-Boot will use R10 to hold a pointer to the global data
6398 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6399 or current versions of GCC may "optimize" the code too much.
6404 U-Boot runs in system state and uses physical addresses, i.e. the
6405 MMU is not used either for address mapping nor for memory protection.
6407 The available memory is mapped to fixed addresses using the memory
6408 controller. In this process, a contiguous block is formed for each
6409 memory type (Flash, SDRAM, SRAM), even when it consists of several
6410 physical memory banks.
6412 U-Boot is installed in the first 128 kB of the first Flash bank (on
6413 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6414 booting and sizing and initializing DRAM, the code relocates itself
6415 to the upper end of DRAM. Immediately below the U-Boot code some
6416 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6417 configuration setting]. Below that, a structure with global Board
6418 Info data is placed, followed by the stack (growing downward).
6420 Additionally, some exception handler code is copied to the low 8 kB
6421 of DRAM (0x00000000 ... 0x00001FFF).
6423 So a typical memory configuration with 16 MB of DRAM could look like
6426 0x0000 0000 Exception Vector code
6429 0x0000 2000 Free for Application Use
6435 0x00FB FF20 Monitor Stack (Growing downward)
6436 0x00FB FFAC Board Info Data and permanent copy of global data
6437 0x00FC 0000 Malloc Arena
6440 0x00FE 0000 RAM Copy of Monitor Code
6441 ... eventually: LCD or video framebuffer
6442 ... eventually: pRAM (Protected RAM - unchanged by reset)
6443 0x00FF FFFF [End of RAM]
6446 System Initialization:
6447 ----------------------
6449 In the reset configuration, U-Boot starts at the reset entry point
6450 (on most PowerPC systems at address 0x00000100). Because of the reset
6451 configuration for CS0# this is a mirror of the onboard Flash memory.
6452 To be able to re-map memory U-Boot then jumps to its link address.
6453 To be able to implement the initialization code in C, a (small!)
6454 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6455 which provide such a feature like MPC8xx or MPC8260), or in a locked
6456 part of the data cache. After that, U-Boot initializes the CPU core,
6457 the caches and the SIU.
6459 Next, all (potentially) available memory banks are mapped using a
6460 preliminary mapping. For example, we put them on 512 MB boundaries
6461 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6462 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6463 programmed for SDRAM access. Using the temporary configuration, a
6464 simple memory test is run that determines the size of the SDRAM
6467 When there is more than one SDRAM bank, and the banks are of
6468 different size, the largest is mapped first. For equal size, the first
6469 bank (CS2#) is mapped first. The first mapping is always for address
6470 0x00000000, with any additional banks following immediately to create
6471 contiguous memory starting from 0.
6473 Then, the monitor installs itself at the upper end of the SDRAM area
6474 and allocates memory for use by malloc() and for the global Board
6475 Info data; also, the exception vector code is copied to the low RAM
6476 pages, and the final stack is set up.
6478 Only after this relocation will you have a "normal" C environment;
6479 until that you are restricted in several ways, mostly because you are
6480 running from ROM, and because the code will have to be relocated to a
6484 U-Boot Porting Guide:
6485 ----------------------
6487 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6491 int main(int argc, char *argv[])
6493 sighandler_t no_more_time;
6495 signal(SIGALRM, no_more_time);
6496 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6498 if (available_money > available_manpower) {
6499 Pay consultant to port U-Boot;
6503 Download latest U-Boot source;
6505 Subscribe to u-boot mailing list;
6508 email("Hi, I am new to U-Boot, how do I get started?");
6511 Read the README file in the top level directory;
6512 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6513 Read applicable doc/*.README;
6514 Read the source, Luke;
6515 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6518 if (available_money > toLocalCurrency ($2500))
6521 Add a lot of aggravation and time;
6523 if (a similar board exists) { /* hopefully... */
6524 cp -a board/<similar> board/<myboard>
6525 cp include/configs/<similar>.h include/configs/<myboard>.h
6527 Create your own board support subdirectory;
6528 Create your own board include/configs/<myboard>.h file;
6530 Edit new board/<myboard> files
6531 Edit new include/configs/<myboard>.h
6536 Add / modify source code;
6540 email("Hi, I am having problems...");
6542 Send patch file to the U-Boot email list;
6543 if (reasonable critiques)
6544 Incorporate improvements from email list code review;
6546 Defend code as written;
6552 void no_more_time (int sig)
6561 All contributions to U-Boot should conform to the Linux kernel
6562 coding style; see the file "Documentation/CodingStyle" and the script
6563 "scripts/Lindent" in your Linux kernel source directory.
6565 Source files originating from a different project (for example the
6566 MTD subsystem) are generally exempt from these guidelines and are not
6567 reformated to ease subsequent migration to newer versions of those
6570 Please note that U-Boot is implemented in C (and to some small parts in
6571 Assembler); no C++ is used, so please do not use C++ style comments (//)
6574 Please also stick to the following formatting rules:
6575 - remove any trailing white space
6576 - use TAB characters for indentation and vertical alignment, not spaces
6577 - make sure NOT to use DOS '\r\n' line feeds
6578 - do not add more than 2 consecutive empty lines to source files
6579 - do not add trailing empty lines to source files
6581 Submissions which do not conform to the standards may be returned
6582 with a request to reformat the changes.
6588 Since the number of patches for U-Boot is growing, we need to
6589 establish some rules. Submissions which do not conform to these rules
6590 may be rejected, even when they contain important and valuable stuff.
6592 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6594 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6595 see http://lists.denx.de/mailman/listinfo/u-boot
6597 When you send a patch, please include the following information with
6600 * For bug fixes: a description of the bug and how your patch fixes
6601 this bug. Please try to include a way of demonstrating that the
6602 patch actually fixes something.
6604 * For new features: a description of the feature and your
6607 * A CHANGELOG entry as plaintext (separate from the patch)
6609 * For major contributions, your entry to the CREDITS file
6611 * When you add support for a new board, don't forget to add a
6612 maintainer e-mail address to the boards.cfg file, too.
6614 * If your patch adds new configuration options, don't forget to
6615 document these in the README file.
6617 * The patch itself. If you are using git (which is *strongly*
6618 recommended) you can easily generate the patch using the
6619 "git format-patch". If you then use "git send-email" to send it to
6620 the U-Boot mailing list, you will avoid most of the common problems
6621 with some other mail clients.
6623 If you cannot use git, use "diff -purN OLD NEW". If your version of
6624 diff does not support these options, then get the latest version of
6627 The current directory when running this command shall be the parent
6628 directory of the U-Boot source tree (i. e. please make sure that
6629 your patch includes sufficient directory information for the
6632 We prefer patches as plain text. MIME attachments are discouraged,
6633 and compressed attachments must not be used.
6635 * If one logical set of modifications affects or creates several
6636 files, all these changes shall be submitted in a SINGLE patch file.
6638 * Changesets that contain different, unrelated modifications shall be
6639 submitted as SEPARATE patches, one patch per changeset.
6644 * Before sending the patch, run the MAKEALL script on your patched
6645 source tree and make sure that no errors or warnings are reported
6646 for any of the boards.
6648 * Keep your modifications to the necessary minimum: A patch
6649 containing several unrelated changes or arbitrary reformats will be
6650 returned with a request to re-formatting / split it.
6652 * If you modify existing code, make sure that your new code does not
6653 add to the memory footprint of the code ;-) Small is beautiful!
6654 When adding new features, these should compile conditionally only
6655 (using #ifdef), and the resulting code with the new feature
6656 disabled must not need more memory than the old code without your
6659 * Remember that there is a size limit of 100 kB per message on the
6660 u-boot mailing list. Bigger patches will be moderated. If they are
6661 reasonable and not too big, they will be acknowledged. But patches
6662 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob