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_A008044_WORKAROUND
413 Enables a workaround for T1040/T1042 erratum A008044. It is only
414 requred during NAND boot and valid for Rev 1.0 SoC revision
416 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
418 This is the value to write into CCSR offset 0x18600
419 according to the A004510 workaround.
421 CONFIG_SYS_FSL_DSP_DDR_ADDR
422 This value denotes start offset of DDR memory which is
423 connected exclusively to the DSP cores.
425 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
426 This value denotes start offset of M2 memory
427 which is directly connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
430 This value denotes start offset of M3 memory which is directly
431 connected to the DSP core.
433 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
434 This value denotes start offset of DSP CCSR space.
436 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
437 Single Source Clock is clocking mode present in some of FSL SoC's.
438 In this mode, a single differential clock is used to supply
439 clocks to the sysclock, ddrclock and usbclock.
441 CONFIG_SYS_CPC_REINIT_F
442 This CONFIG is defined when the CPC is configured as SRAM at the
443 time of U-boot entry and is required to be re-initialized.
446 Inidcates this SoC supports deep sleep feature. If deep sleep is
447 supported, core will start to execute uboot when wakes up.
449 - Generic CPU options:
450 CONFIG_SYS_GENERIC_GLOBAL_DATA
451 Defines global data is initialized in generic board board_init_f().
452 If this macro is defined, global data is created and cleared in
453 generic board board_init_f(). Without this macro, architecture/board
454 should initialize global data before calling board_init_f().
456 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
458 Defines the endianess of the CPU. Implementation of those
459 values is arch specific.
462 Freescale DDR driver in use. This type of DDR controller is
463 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
466 CONFIG_SYS_FSL_DDR_ADDR
467 Freescale DDR memory-mapped register base.
469 CONFIG_SYS_FSL_DDR_EMU
470 Specify emulator support for DDR. Some DDR features such as
471 deskew training are not available.
473 CONFIG_SYS_FSL_DDRC_GEN1
474 Freescale DDR1 controller.
476 CONFIG_SYS_FSL_DDRC_GEN2
477 Freescale DDR2 controller.
479 CONFIG_SYS_FSL_DDRC_GEN3
480 Freescale DDR3 controller.
482 CONFIG_SYS_FSL_DDRC_GEN4
483 Freescale DDR4 controller.
485 CONFIG_SYS_FSL_DDRC_ARM_GEN3
486 Freescale DDR3 controller for ARM-based SoCs.
489 Board config to use DDR1. It can be enabled for SoCs with
490 Freescale DDR1 or DDR2 controllers, depending on the board
494 Board config to use DDR2. It can be eanbeld for SoCs with
495 Freescale DDR2 or DDR3 controllers, depending on the board
499 Board config to use DDR3. It can be enabled for SoCs with
500 Freescale DDR3 or DDR3L controllers.
503 Board config to use DDR3L. It can be enabled for SoCs with
507 Board config to use DDR4. It can be enabled for SoCs with
510 CONFIG_SYS_FSL_IFC_BE
511 Defines the IFC controller register space as Big Endian
513 CONFIG_SYS_FSL_IFC_LE
514 Defines the IFC controller register space as Little Endian
516 CONFIG_SYS_FSL_PBL_PBI
517 It enables addition of RCW (Power on reset configuration) in built image.
518 Please refer doc/README.pblimage for more details
520 CONFIG_SYS_FSL_PBL_RCW
521 It adds PBI(pre-boot instructions) commands in u-boot build image.
522 PBI commands can be used to configure SoC before it starts the execution.
523 Please refer doc/README.pblimage for more details
526 It adds a target to create boot binary having SPL binary in PBI format
527 concatenated with u-boot binary.
529 CONFIG_SYS_FSL_DDR_BE
530 Defines the DDR controller register space as Big Endian
532 CONFIG_SYS_FSL_DDR_LE
533 Defines the DDR controller register space as Little Endian
535 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
536 Physical address from the view of DDR controllers. It is the
537 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
538 it could be different for ARM SoCs.
540 CONFIG_SYS_FSL_DDR_INTLV_256B
541 DDR controller interleaving on 256-byte. This is a special
542 interleaving mode, handled by Dickens for Freescale layerscape
545 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
546 Number of controllers used as main memory.
548 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
549 Number of controllers used for other than main memory.
551 CONFIG_SYS_FSL_SEC_BE
552 Defines the SEC controller register space as Big Endian
554 CONFIG_SYS_FSL_SEC_LE
555 Defines the SEC controller register space as Little Endian
557 - Intel Monahans options:
558 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
560 Defines the Monahans run mode to oscillator
561 ratio. Valid values are 8, 16, 24, 31. The core
562 frequency is this value multiplied by 13 MHz.
564 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
566 Defines the Monahans turbo mode to oscillator
567 ratio. Valid values are 1 (default if undefined) and
568 2. The core frequency as calculated above is multiplied
572 CONFIG_SYS_INIT_SP_OFFSET
574 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
575 pointer. This is needed for the temporary stack before
578 CONFIG_SYS_MIPS_CACHE_MODE
580 Cache operation mode for the MIPS CPU.
581 See also arch/mips/include/asm/mipsregs.h.
583 CONF_CM_CACHABLE_NO_WA
586 CONF_CM_CACHABLE_NONCOHERENT
590 CONF_CM_CACHABLE_ACCELERATED
592 CONFIG_SYS_XWAY_EBU_BOOTCFG
594 Special option for Lantiq XWAY SoCs for booting from NOR flash.
595 See also arch/mips/cpu/mips32/start.S.
597 CONFIG_XWAY_SWAP_BYTES
599 Enable compilation of tools/xway-swap-bytes needed for Lantiq
600 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
601 be swapped if a flash programmer is used.
604 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
606 Select high exception vectors of the ARM core, e.g., do not
607 clear the V bit of the c1 register of CP15.
609 CONFIG_SYS_THUMB_BUILD
611 Use this flag to build U-Boot using the Thumb instruction
612 set for ARM architectures. Thumb instruction set provides
613 better code density. For ARM architectures that support
614 Thumb2 this flag will result in Thumb2 code generated by
617 CONFIG_ARM_ERRATA_716044
618 CONFIG_ARM_ERRATA_742230
619 CONFIG_ARM_ERRATA_743622
620 CONFIG_ARM_ERRATA_751472
621 CONFIG_ARM_ERRATA_794072
622 CONFIG_ARM_ERRATA_761320
624 If set, the workarounds for these ARM errata are applied early
625 during U-Boot startup. Note that these options force the
626 workarounds to be applied; no CPU-type/version detection
627 exists, unlike the similar options in the Linux kernel. Do not
628 set these options unless they apply!
631 Driver model is a new framework for devices in U-Boot
632 introduced in early 2014. U-Boot is being progressively
633 moved over to this. It offers a consistent device structure,
634 supports grouping devices into classes and has built-in
635 handling of platform data and device tree.
637 To enable transition to driver model in a relatively
638 painful fashion, each subsystem can be independently
639 switched between the legacy/ad-hoc approach and the new
640 driver model using the options below. Also, many uclass
641 interfaces include compatibility features which may be
642 removed once the conversion of that subsystem is complete.
643 As a result, the API provided by the subsystem may in fact
644 not change with driver model.
646 See doc/driver-model/README.txt for more information.
650 Enable driver model. This brings in the core support,
651 including scanning of platform data on start-up. If
652 CONFIG_OF_CONTROL is enabled, the device tree will be
653 scanned also when available.
657 Enable driver model test commands. These allow you to print
658 out the driver model tree and the uclasses.
662 Enable some demo devices and the 'demo' command. These are
663 really only useful for playing around while trying to
664 understand driver model in sandbox.
668 Enable driver model in SPL. You will need to provide a
669 suitable malloc() implementation. If you are not using the
670 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
671 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
672 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
673 In most cases driver model will only allocate a few uclasses
674 and devices in SPL, so 1KB should be enable. See
675 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
680 Enable driver model for serial. This replaces
681 drivers/serial/serial.c with the serial uclass, which
682 implements serial_putc() etc. The uclass interface is
683 defined in include/serial.h.
687 Enable driver model for GPIO access. The standard GPIO
688 interface (gpio_get_value(), etc.) is then implemented by
689 the GPIO uclass. Drivers provide methods to query the
690 particular GPIOs that they provide. The uclass interface
691 is defined in include/asm-generic/gpio.h.
695 Enable driver model for SPI. The SPI slave interface
696 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
697 the SPI uclass. Drivers provide methods to access the SPI
698 buses that they control. The uclass interface is defined in
699 include/spi.h. The existing spi_slave structure is attached
700 as 'parent data' to every slave on each bus. Slaves
701 typically use driver-private data instead of extending the
706 Enable driver model for SPI flash. This SPI flash interface
707 (spi_flash_probe(), spi_flash_write(), etc.) is then
708 implemented by the SPI flash uclass. There is one standard
709 SPI flash driver which knows how to probe most chips
710 supported by U-Boot. The uclass interface is defined in
711 include/spi_flash.h, but is currently fully compatible
712 with the old interface to avoid confusion and duplication
713 during the transition parent. SPI and SPI flash must be
714 enabled together (it is not possible to use driver model
715 for one and not the other).
719 Enable driver model for the Chrome OS EC interface. This
720 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
721 but otherwise makes few changes. Since cros_ec also supports
722 I2C and LPC (which don't support driver model yet), a full
723 conversion is not yet possible.
726 ** Code size options: The following options are enabled by
727 default except in SPL. Enable them explicitly to get these
732 Enable the dm_warn() function. This can use up quite a bit
733 of space for its strings.
737 Enable registering a serial device with the stdio library.
739 CONFIG_DM_DEVICE_REMOVE
741 Enable removing of devices.
744 - Linux Kernel Interface:
747 U-Boot stores all clock information in Hz
748 internally. For binary compatibility with older Linux
749 kernels (which expect the clocks passed in the
750 bd_info data to be in MHz) the environment variable
751 "clocks_in_mhz" can be defined so that U-Boot
752 converts clock data to MHZ before passing it to the
754 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
755 "clocks_in_mhz=1" is automatically included in the
758 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
760 When transferring memsize parameter to linux, some versions
761 expect it to be in bytes, others in MB.
762 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
766 New kernel versions are expecting firmware settings to be
767 passed using flattened device trees (based on open firmware
771 * New libfdt-based support
772 * Adds the "fdt" command
773 * The bootm command automatically updates the fdt
775 OF_CPU - The proper name of the cpus node (only required for
776 MPC512X and MPC5xxx based boards).
777 OF_SOC - The proper name of the soc node (only required for
778 MPC512X and MPC5xxx based boards).
779 OF_TBCLK - The timebase frequency.
780 OF_STDOUT_PATH - The path to the console device
782 boards with QUICC Engines require OF_QE to set UCC MAC
785 CONFIG_OF_BOARD_SETUP
787 Board code has addition modification that it wants to make
788 to the flat device tree before handing it off to the kernel
790 CONFIG_OF_SYSTEM_SETUP
792 Other code has addition modification that it wants to make
793 to the flat device tree before handing it off to the kernel.
794 This causes ft_system_setup() to be called before booting
799 This define fills in the correct boot CPU in the boot
800 param header, the default value is zero if undefined.
804 U-Boot can detect if an IDE device is present or not.
805 If not, and this new config option is activated, U-Boot
806 removes the ATA node from the DTS before booting Linux,
807 so the Linux IDE driver does not probe the device and
808 crash. This is needed for buggy hardware (uc101) where
809 no pull down resistor is connected to the signal IDE5V_DD7.
811 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
813 This setting is mandatory for all boards that have only one
814 machine type and must be used to specify the machine type
815 number as it appears in the ARM machine registry
816 (see http://www.arm.linux.org.uk/developer/machines/).
817 Only boards that have multiple machine types supported
818 in a single configuration file and the machine type is
819 runtime discoverable, do not have to use this setting.
821 - vxWorks boot parameters:
823 bootvx constructs a valid bootline using the following
824 environments variables: bootfile, ipaddr, serverip, hostname.
825 It loads the vxWorks image pointed bootfile.
827 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
828 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
829 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
830 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
832 CONFIG_SYS_VXWORKS_ADD_PARAMS
834 Add it at the end of the bootline. E.g "u=username pw=secret"
836 Note: If a "bootargs" environment is defined, it will overwride
837 the defaults discussed just above.
839 - Cache Configuration:
840 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
841 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
842 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
844 - Cache Configuration for ARM:
845 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
847 CONFIG_SYS_PL310_BASE - Physical base address of PL310
848 controller register space
853 Define this if you want support for Amba PrimeCell PL010 UARTs.
857 Define this if you want support for Amba PrimeCell PL011 UARTs.
861 If you have Amba PrimeCell PL011 UARTs, set this variable to
862 the clock speed of the UARTs.
866 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
867 define this to a list of base addresses for each (supported)
868 port. See e.g. include/configs/versatile.h
870 CONFIG_PL011_SERIAL_RLCR
872 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
873 have separate receive and transmit line control registers. Set
874 this variable to initialize the extra register.
876 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
878 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
879 boot loader that has already initialized the UART. Define this
880 variable to flush the UART at init time.
882 CONFIG_SERIAL_HW_FLOW_CONTROL
884 Define this variable to enable hw flow control in serial driver.
885 Current user of this option is drivers/serial/nsl16550.c driver
888 Depending on board, define exactly one serial port
889 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
890 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
891 console by defining CONFIG_8xx_CONS_NONE
893 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
894 port routines must be defined elsewhere
895 (i.e. serial_init(), serial_getc(), ...)
898 Enables console device for a color framebuffer. Needs following
899 defines (cf. smiLynxEM, i8042)
900 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
902 VIDEO_HW_RECTFILL graphic chip supports
905 VIDEO_HW_BITBLT graphic chip supports
906 bit-blit (cf. smiLynxEM)
907 VIDEO_VISIBLE_COLS visible pixel columns
909 VIDEO_VISIBLE_ROWS visible pixel rows
910 VIDEO_PIXEL_SIZE bytes per pixel
911 VIDEO_DATA_FORMAT graphic data format
912 (0-5, cf. cfb_console.c)
913 VIDEO_FB_ADRS framebuffer address
914 VIDEO_KBD_INIT_FCT keyboard int fct
915 (i.e. i8042_kbd_init())
916 VIDEO_TSTC_FCT test char fct
918 VIDEO_GETC_FCT get char fct
920 CONFIG_CONSOLE_CURSOR cursor drawing on/off
921 (requires blink timer
923 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
924 CONFIG_CONSOLE_TIME display time/date info in
926 (requires CONFIG_CMD_DATE)
927 CONFIG_VIDEO_LOGO display Linux logo in
929 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
930 linux_logo.h for logo.
931 Requires CONFIG_VIDEO_LOGO
932 CONFIG_CONSOLE_EXTRA_INFO
933 additional board info beside
936 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
937 a limited number of ANSI escape sequences (cursor control,
938 erase functions and limited graphics rendition control).
940 When CONFIG_CFB_CONSOLE is defined, video console is
941 default i/o. Serial console can be forced with
942 environment 'console=serial'.
944 When CONFIG_SILENT_CONSOLE is defined, all console
945 messages (by U-Boot and Linux!) can be silenced with
946 the "silent" environment variable. See
947 doc/README.silent for more information.
949 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
951 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
955 CONFIG_BAUDRATE - in bps
956 Select one of the baudrates listed in
957 CONFIG_SYS_BAUDRATE_TABLE, see below.
958 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
960 - Console Rx buffer length
961 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
962 the maximum receive buffer length for the SMC.
963 This option is actual only for 82xx and 8xx possible.
964 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
965 must be defined, to setup the maximum idle timeout for
968 - Pre-Console Buffer:
969 Prior to the console being initialised (i.e. serial UART
970 initialised etc) all console output is silently discarded.
971 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
972 buffer any console messages prior to the console being
973 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
974 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
975 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
976 bytes are output before the console is initialised, the
977 earlier bytes are discarded.
979 'Sane' compilers will generate smaller code if
980 CONFIG_PRE_CON_BUF_SZ is a power of 2
982 - Safe printf() functions
983 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
984 the printf() functions. These are defined in
985 include/vsprintf.h and include snprintf(), vsnprintf() and
986 so on. Code size increase is approximately 300-500 bytes.
987 If this option is not given then these functions will
988 silently discard their buffer size argument - this means
989 you are not getting any overflow checking in this case.
991 - Boot Delay: CONFIG_BOOTDELAY - in seconds
992 Delay before automatically booting the default image;
993 set to -1 to disable autoboot.
994 set to -2 to autoboot with no delay and not check for abort
995 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
997 See doc/README.autoboot for these options that
998 work with CONFIG_BOOTDELAY. None are required.
999 CONFIG_BOOT_RETRY_TIME
1000 CONFIG_BOOT_RETRY_MIN
1001 CONFIG_AUTOBOOT_KEYED
1002 CONFIG_AUTOBOOT_PROMPT
1003 CONFIG_AUTOBOOT_DELAY_STR
1004 CONFIG_AUTOBOOT_STOP_STR
1005 CONFIG_AUTOBOOT_DELAY_STR2
1006 CONFIG_AUTOBOOT_STOP_STR2
1007 CONFIG_ZERO_BOOTDELAY_CHECK
1008 CONFIG_RESET_TO_RETRY
1012 Only needed when CONFIG_BOOTDELAY is enabled;
1013 define a command string that is automatically executed
1014 when no character is read on the console interface
1015 within "Boot Delay" after reset.
1018 This can be used to pass arguments to the bootm
1019 command. The value of CONFIG_BOOTARGS goes into the
1020 environment value "bootargs".
1022 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1023 The value of these goes into the environment as
1024 "ramboot" and "nfsboot" respectively, and can be used
1025 as a convenience, when switching between booting from
1029 CONFIG_BOOTCOUNT_LIMIT
1030 Implements a mechanism for detecting a repeating reboot
1032 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1034 CONFIG_BOOTCOUNT_ENV
1035 If no softreset save registers are found on the hardware
1036 "bootcount" is stored in the environment. To prevent a
1037 saveenv on all reboots, the environment variable
1038 "upgrade_available" is used. If "upgrade_available" is
1039 0, "bootcount" is always 0, if "upgrade_available" is
1040 1 "bootcount" is incremented in the environment.
1041 So the Userspace Applikation must set the "upgrade_available"
1042 and "bootcount" variable to 0, if a boot was successfully.
1044 - Pre-Boot Commands:
1047 When this option is #defined, the existence of the
1048 environment variable "preboot" will be checked
1049 immediately before starting the CONFIG_BOOTDELAY
1050 countdown and/or running the auto-boot command resp.
1051 entering interactive mode.
1053 This feature is especially useful when "preboot" is
1054 automatically generated or modified. For an example
1055 see the LWMON board specific code: here "preboot" is
1056 modified when the user holds down a certain
1057 combination of keys on the (special) keyboard when
1060 - Serial Download Echo Mode:
1062 If defined to 1, all characters received during a
1063 serial download (using the "loads" command) are
1064 echoed back. This might be needed by some terminal
1065 emulations (like "cu"), but may as well just take
1066 time on others. This setting #define's the initial
1067 value of the "loads_echo" environment variable.
1069 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1070 CONFIG_KGDB_BAUDRATE
1071 Select one of the baudrates listed in
1072 CONFIG_SYS_BAUDRATE_TABLE, see below.
1074 - Monitor Functions:
1075 Monitor commands can be included or excluded
1076 from the build by using the #include files
1077 <config_cmd_all.h> and #undef'ing unwanted
1078 commands, or using <config_cmd_default.h>
1079 and augmenting with additional #define's
1080 for wanted commands.
1082 The default command configuration includes all commands
1083 except those marked below with a "*".
1085 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1086 CONFIG_CMD_ASKENV * ask for env variable
1087 CONFIG_CMD_BDI bdinfo
1088 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1089 CONFIG_CMD_BMP * BMP support
1090 CONFIG_CMD_BSP * Board specific commands
1091 CONFIG_CMD_BOOTD bootd
1092 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1093 CONFIG_CMD_CACHE * icache, dcache
1094 CONFIG_CMD_CLK * clock command support
1095 CONFIG_CMD_CONSOLE coninfo
1096 CONFIG_CMD_CRC32 * crc32
1097 CONFIG_CMD_DATE * support for RTC, date/time...
1098 CONFIG_CMD_DHCP * DHCP support
1099 CONFIG_CMD_DIAG * Diagnostics
1100 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1101 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1102 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1103 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1104 CONFIG_CMD_DTT * Digital Therm and Thermostat
1105 CONFIG_CMD_ECHO echo arguments
1106 CONFIG_CMD_EDITENV edit env variable
1107 CONFIG_CMD_EEPROM * EEPROM read/write support
1108 CONFIG_CMD_ELF * bootelf, bootvx
1109 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1110 CONFIG_CMD_ENV_FLAGS * display details about env flags
1111 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1112 CONFIG_CMD_EXPORTENV * export the environment
1113 CONFIG_CMD_EXT2 * ext2 command support
1114 CONFIG_CMD_EXT4 * ext4 command support
1115 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1116 that work for multiple fs types
1117 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1118 CONFIG_CMD_SAVEENV saveenv
1119 CONFIG_CMD_FDC * Floppy Disk Support
1120 CONFIG_CMD_FAT * FAT command support
1121 CONFIG_CMD_FLASH flinfo, erase, protect
1122 CONFIG_CMD_FPGA FPGA device initialization support
1123 CONFIG_CMD_FUSE * Device fuse support
1124 CONFIG_CMD_GETTIME * Get time since boot
1125 CONFIG_CMD_GO * the 'go' command (exec code)
1126 CONFIG_CMD_GREPENV * search environment
1127 CONFIG_CMD_HASH * calculate hash / digest
1128 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1129 CONFIG_CMD_I2C * I2C serial bus support
1130 CONFIG_CMD_IDE * IDE harddisk support
1131 CONFIG_CMD_IMI iminfo
1132 CONFIG_CMD_IMLS List all images found in NOR flash
1133 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1134 CONFIG_CMD_IMMAP * IMMR dump support
1135 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1136 CONFIG_CMD_IMPORTENV * import an environment
1137 CONFIG_CMD_INI * import data from an ini file into the env
1138 CONFIG_CMD_IRQ * irqinfo
1139 CONFIG_CMD_ITEST Integer/string test of 2 values
1140 CONFIG_CMD_JFFS2 * JFFS2 Support
1141 CONFIG_CMD_KGDB * kgdb
1142 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1143 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1145 CONFIG_CMD_LOADB loadb
1146 CONFIG_CMD_LOADS loads
1147 CONFIG_CMD_MD5SUM * print md5 message digest
1148 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1149 CONFIG_CMD_MEMINFO * Display detailed memory information
1150 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1152 CONFIG_CMD_MEMTEST * mtest
1153 CONFIG_CMD_MISC Misc functions like sleep etc
1154 CONFIG_CMD_MMC * MMC memory mapped support
1155 CONFIG_CMD_MII * MII utility commands
1156 CONFIG_CMD_MTDPARTS * MTD partition support
1157 CONFIG_CMD_NAND * NAND support
1158 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1159 CONFIG_CMD_NFS NFS support
1160 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1161 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1162 CONFIG_CMD_PCI * pciinfo
1163 CONFIG_CMD_PCMCIA * PCMCIA support
1164 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1166 CONFIG_CMD_PORTIO * Port I/O
1167 CONFIG_CMD_READ * Read raw data from partition
1168 CONFIG_CMD_REGINFO * Register dump
1169 CONFIG_CMD_RUN run command in env variable
1170 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1171 CONFIG_CMD_SAVES * save S record dump
1172 CONFIG_CMD_SCSI * SCSI Support
1173 CONFIG_CMD_SDRAM * print SDRAM configuration information
1174 (requires CONFIG_CMD_I2C)
1175 CONFIG_CMD_SETGETDCR Support for DCR Register access
1177 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1178 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1179 (requires CONFIG_CMD_MEMORY)
1180 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1181 CONFIG_CMD_SOURCE "source" command Support
1182 CONFIG_CMD_SPI * SPI serial bus support
1183 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1184 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1185 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1186 CONFIG_CMD_TIMER * access to the system tick timer
1187 CONFIG_CMD_USB * USB support
1188 CONFIG_CMD_CDP * Cisco Discover Protocol support
1189 CONFIG_CMD_MFSL * Microblaze FSL support
1190 CONFIG_CMD_XIMG Load part of Multi Image
1191 CONFIG_CMD_UUID * Generate random UUID or GUID string
1193 EXAMPLE: If you want all functions except of network
1194 support you can write:
1196 #include "config_cmd_all.h"
1197 #undef CONFIG_CMD_NET
1200 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1202 Note: Don't enable the "icache" and "dcache" commands
1203 (configuration option CONFIG_CMD_CACHE) unless you know
1204 what you (and your U-Boot users) are doing. Data
1205 cache cannot be enabled on systems like the 8xx or
1206 8260 (where accesses to the IMMR region must be
1207 uncached), and it cannot be disabled on all other
1208 systems where we (mis-) use the data cache to hold an
1209 initial stack and some data.
1212 XXX - this list needs to get updated!
1214 - Regular expression support:
1216 If this variable is defined, U-Boot is linked against
1217 the SLRE (Super Light Regular Expression) library,
1218 which adds regex support to some commands, as for
1219 example "env grep" and "setexpr".
1223 If this variable is defined, U-Boot will use a device tree
1224 to configure its devices, instead of relying on statically
1225 compiled #defines in the board file. This option is
1226 experimental and only available on a few boards. The device
1227 tree is available in the global data as gd->fdt_blob.
1229 U-Boot needs to get its device tree from somewhere. This can
1230 be done using one of the two options below:
1233 If this variable is defined, U-Boot will embed a device tree
1234 binary in its image. This device tree file should be in the
1235 board directory and called <soc>-<board>.dts. The binary file
1236 is then picked up in board_init_f() and made available through
1237 the global data structure as gd->blob.
1240 If this variable is defined, U-Boot will build a device tree
1241 binary. It will be called u-boot.dtb. Architecture-specific
1242 code will locate it at run-time. Generally this works by:
1244 cat u-boot.bin u-boot.dtb >image.bin
1246 and in fact, U-Boot does this for you, creating a file called
1247 u-boot-dtb.bin which is useful in the common case. You can
1248 still use the individual files if you need something more
1253 If this variable is defined, it enables watchdog
1254 support for the SoC. There must be support in the SoC
1255 specific code for a watchdog. For the 8xx and 8260
1256 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1257 register. When supported for a specific SoC is
1258 available, then no further board specific code should
1259 be needed to use it.
1262 When using a watchdog circuitry external to the used
1263 SoC, then define this variable and provide board
1264 specific code for the "hw_watchdog_reset" function.
1267 CONFIG_VERSION_VARIABLE
1268 If this variable is defined, an environment variable
1269 named "ver" is created by U-Boot showing the U-Boot
1270 version as printed by the "version" command.
1271 Any change to this variable will be reverted at the
1276 When CONFIG_CMD_DATE is selected, the type of the RTC
1277 has to be selected, too. Define exactly one of the
1280 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1281 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1282 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1283 CONFIG_RTC_MC146818 - use MC146818 RTC
1284 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1285 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1286 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1287 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1288 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1289 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1290 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1291 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1292 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1295 Note that if the RTC uses I2C, then the I2C interface
1296 must also be configured. See I2C Support, below.
1299 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1301 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1302 chip-ngpio pairs that tell the PCA953X driver the number of
1303 pins supported by a particular chip.
1305 Note that if the GPIO device uses I2C, then the I2C interface
1306 must also be configured. See I2C Support, below.
1309 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1310 accesses and can checksum them or write a list of them out
1311 to memory. See the 'iotrace' command for details. This is
1312 useful for testing device drivers since it can confirm that
1313 the driver behaves the same way before and after a code
1314 change. Currently this is supported on sandbox and arm. To
1315 add support for your architecture, add '#include <iotrace.h>'
1316 to the bottom of arch/<arch>/include/asm/io.h and test.
1318 Example output from the 'iotrace stats' command is below.
1319 Note that if the trace buffer is exhausted, the checksum will
1320 still continue to operate.
1323 Start: 10000000 (buffer start address)
1324 Size: 00010000 (buffer size)
1325 Offset: 00000120 (current buffer offset)
1326 Output: 10000120 (start + offset)
1327 Count: 00000018 (number of trace records)
1328 CRC32: 9526fb66 (CRC32 of all trace records)
1330 - Timestamp Support:
1332 When CONFIG_TIMESTAMP is selected, the timestamp
1333 (date and time) of an image is printed by image
1334 commands like bootm or iminfo. This option is
1335 automatically enabled when you select CONFIG_CMD_DATE .
1337 - Partition Labels (disklabels) Supported:
1338 Zero or more of the following:
1339 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1340 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1341 Intel architecture, USB sticks, etc.
1342 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1343 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1344 bootloader. Note 2TB partition limit; see
1346 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1348 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1349 CONFIG_CMD_SCSI) you must configure support for at
1350 least one non-MTD partition type as well.
1353 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1354 board configurations files but used nowhere!
1356 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1357 be performed by calling the function
1358 ide_set_reset(int reset)
1359 which has to be defined in a board specific file
1364 Set this to enable ATAPI support.
1369 Set this to enable support for disks larger than 137GB
1370 Also look at CONFIG_SYS_64BIT_LBA.
1371 Whithout these , LBA48 support uses 32bit variables and will 'only'
1372 support disks up to 2.1TB.
1374 CONFIG_SYS_64BIT_LBA:
1375 When enabled, makes the IDE subsystem use 64bit sector addresses.
1379 At the moment only there is only support for the
1380 SYM53C8XX SCSI controller; define
1381 CONFIG_SCSI_SYM53C8XX to enable it.
1383 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1384 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1385 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1386 maximum numbers of LUNs, SCSI ID's and target
1388 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1390 The environment variable 'scsidevs' is set to the number of
1391 SCSI devices found during the last scan.
1393 - NETWORK Support (PCI):
1395 Support for Intel 8254x/8257x gigabit chips.
1398 Utility code for direct access to the SPI bus on Intel 8257x.
1399 This does not do anything useful unless you set at least one
1400 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1402 CONFIG_E1000_SPI_GENERIC
1403 Allow generic access to the SPI bus on the Intel 8257x, for
1404 example with the "sspi" command.
1407 Management command for E1000 devices. When used on devices
1408 with SPI support you can reprogram the EEPROM from U-Boot.
1410 CONFIG_E1000_FALLBACK_MAC
1411 default MAC for empty EEPROM after production.
1414 Support for Intel 82557/82559/82559ER chips.
1415 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1416 write routine for first time initialisation.
1419 Support for Digital 2114x chips.
1420 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1421 modem chip initialisation (KS8761/QS6611).
1424 Support for National dp83815 chips.
1427 Support for National dp8382[01] gigabit chips.
1429 - NETWORK Support (other):
1431 CONFIG_DRIVER_AT91EMAC
1432 Support for AT91RM9200 EMAC.
1435 Define this to use reduced MII inteface
1437 CONFIG_DRIVER_AT91EMAC_QUIET
1438 If this defined, the driver is quiet.
1439 The driver doen't show link status messages.
1441 CONFIG_CALXEDA_XGMAC
1442 Support for the Calxeda XGMAC device
1445 Support for SMSC's LAN91C96 chips.
1447 CONFIG_LAN91C96_BASE
1448 Define this to hold the physical address
1449 of the LAN91C96's I/O space
1451 CONFIG_LAN91C96_USE_32_BIT
1452 Define this to enable 32 bit addressing
1455 Support for SMSC's LAN91C111 chip
1457 CONFIG_SMC91111_BASE
1458 Define this to hold the physical address
1459 of the device (I/O space)
1461 CONFIG_SMC_USE_32_BIT
1462 Define this if data bus is 32 bits
1464 CONFIG_SMC_USE_IOFUNCS
1465 Define this to use i/o functions instead of macros
1466 (some hardware wont work with macros)
1468 CONFIG_DRIVER_TI_EMAC
1469 Support for davinci emac
1471 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1472 Define this if you have more then 3 PHYs.
1475 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1477 CONFIG_FTGMAC100_EGIGA
1478 Define this to use GE link update with gigabit PHY.
1479 Define this if FTGMAC100 is connected to gigabit PHY.
1480 If your system has 10/100 PHY only, it might not occur
1481 wrong behavior. Because PHY usually return timeout or
1482 useless data when polling gigabit status and gigabit
1483 control registers. This behavior won't affect the
1484 correctnessof 10/100 link speed update.
1487 Support for SMSC's LAN911x and LAN921x chips
1490 Define this to hold the physical address
1491 of the device (I/O space)
1493 CONFIG_SMC911X_32_BIT
1494 Define this if data bus is 32 bits
1496 CONFIG_SMC911X_16_BIT
1497 Define this if data bus is 16 bits. If your processor
1498 automatically converts one 32 bit word to two 16 bit
1499 words you may also try CONFIG_SMC911X_32_BIT.
1502 Support for Renesas on-chip Ethernet controller
1504 CONFIG_SH_ETHER_USE_PORT
1505 Define the number of ports to be used
1507 CONFIG_SH_ETHER_PHY_ADDR
1508 Define the ETH PHY's address
1510 CONFIG_SH_ETHER_CACHE_WRITEBACK
1511 If this option is set, the driver enables cache flush.
1515 Support for PWM modul on the imx6.
1519 Support TPM devices.
1522 Support for i2c bus TPM devices. Only one device
1523 per system is supported at this time.
1525 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1526 Define the the i2c bus number for the TPM device
1528 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1529 Define the TPM's address on the i2c bus
1531 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1532 Define the burst count bytes upper limit
1534 CONFIG_TPM_ATMEL_TWI
1535 Support for Atmel TWI TPM device. Requires I2C support.
1538 Support for generic parallel port TPM devices. Only one device
1539 per system is supported at this time.
1541 CONFIG_TPM_TIS_BASE_ADDRESS
1542 Base address where the generic TPM device is mapped
1543 to. Contemporary x86 systems usually map it at
1547 Add tpm monitor functions.
1548 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1549 provides monitor access to authorized functions.
1552 Define this to enable the TPM support library which provides
1553 functional interfaces to some TPM commands.
1554 Requires support for a TPM device.
1556 CONFIG_TPM_AUTH_SESSIONS
1557 Define this to enable authorized functions in the TPM library.
1558 Requires CONFIG_TPM and CONFIG_SHA1.
1561 At the moment only the UHCI host controller is
1562 supported (PIP405, MIP405, MPC5200); define
1563 CONFIG_USB_UHCI to enable it.
1564 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1565 and define CONFIG_USB_STORAGE to enable the USB
1568 Supported are USB Keyboards and USB Floppy drives
1570 MPC5200 USB requires additional defines:
1572 for 528 MHz Clock: 0x0001bbbb
1576 for differential drivers: 0x00001000
1577 for single ended drivers: 0x00005000
1578 for differential drivers on PSC3: 0x00000100
1579 for single ended drivers on PSC3: 0x00004100
1580 CONFIG_SYS_USB_EVENT_POLL
1581 May be defined to allow interrupt polling
1582 instead of using asynchronous interrupts
1584 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1585 txfilltuning field in the EHCI controller on reset.
1587 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1588 HW module registers.
1591 Define the below if you wish to use the USB console.
1592 Once firmware is rebuilt from a serial console issue the
1593 command "setenv stdin usbtty; setenv stdout usbtty" and
1594 attach your USB cable. The Unix command "dmesg" should print
1595 it has found a new device. The environment variable usbtty
1596 can be set to gserial or cdc_acm to enable your device to
1597 appear to a USB host as a Linux gserial device or a
1598 Common Device Class Abstract Control Model serial device.
1599 If you select usbtty = gserial you should be able to enumerate
1601 # modprobe usbserial vendor=0xVendorID product=0xProductID
1602 else if using cdc_acm, simply setting the environment
1603 variable usbtty to be cdc_acm should suffice. The following
1604 might be defined in YourBoardName.h
1607 Define this to build a UDC device
1610 Define this to have a tty type of device available to
1611 talk to the UDC device
1614 Define this to enable the high speed support for usb
1615 device and usbtty. If this feature is enabled, a routine
1616 int is_usbd_high_speed(void)
1617 also needs to be defined by the driver to dynamically poll
1618 whether the enumeration has succeded at high speed or full
1621 CONFIG_SYS_CONSOLE_IS_IN_ENV
1622 Define this if you want stdin, stdout &/or stderr to
1626 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1627 Derive USB clock from external clock "blah"
1628 - CONFIG_SYS_USB_EXTC_CLK 0x02
1630 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1631 Derive USB clock from brgclk
1632 - CONFIG_SYS_USB_BRG_CLK 0x04
1634 If you have a USB-IF assigned VendorID then you may wish to
1635 define your own vendor specific values either in BoardName.h
1636 or directly in usbd_vendor_info.h. If you don't define
1637 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1638 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1639 should pretend to be a Linux device to it's target host.
1641 CONFIG_USBD_MANUFACTURER
1642 Define this string as the name of your company for
1643 - CONFIG_USBD_MANUFACTURER "my company"
1645 CONFIG_USBD_PRODUCT_NAME
1646 Define this string as the name of your product
1647 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1649 CONFIG_USBD_VENDORID
1650 Define this as your assigned Vendor ID from the USB
1651 Implementors Forum. This *must* be a genuine Vendor ID
1652 to avoid polluting the USB namespace.
1653 - CONFIG_USBD_VENDORID 0xFFFF
1655 CONFIG_USBD_PRODUCTID
1656 Define this as the unique Product ID
1658 - CONFIG_USBD_PRODUCTID 0xFFFF
1660 - ULPI Layer Support:
1661 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1662 the generic ULPI layer. The generic layer accesses the ULPI PHY
1663 via the platform viewport, so you need both the genric layer and
1664 the viewport enabled. Currently only Chipidea/ARC based
1665 viewport is supported.
1666 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1667 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1668 If your ULPI phy needs a different reference clock than the
1669 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1670 the appropriate value in Hz.
1673 The MMC controller on the Intel PXA is supported. To
1674 enable this define CONFIG_MMC. The MMC can be
1675 accessed from the boot prompt by mapping the device
1676 to physical memory similar to flash. Command line is
1677 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1678 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1681 Support for Renesas on-chip MMCIF controller
1683 CONFIG_SH_MMCIF_ADDR
1684 Define the base address of MMCIF registers
1687 Define the clock frequency for MMCIF
1690 Enable the generic MMC driver
1692 CONFIG_SUPPORT_EMMC_BOOT
1693 Enable some additional features of the eMMC boot partitions.
1695 CONFIG_SUPPORT_EMMC_RPMB
1696 Enable the commands for reading, writing and programming the
1697 key for the Replay Protection Memory Block partition in eMMC.
1699 - USB Device Firmware Update (DFU) class support:
1701 This enables the USB portion of the DFU USB class
1704 This enables the command "dfu" which is used to have
1705 U-Boot create a DFU class device via USB. This command
1706 requires that the "dfu_alt_info" environment variable be
1707 set and define the alt settings to expose to the host.
1710 This enables support for exposing (e)MMC devices via DFU.
1713 This enables support for exposing NAND devices via DFU.
1716 This enables support for exposing RAM via DFU.
1717 Note: DFU spec refer to non-volatile memory usage, but
1718 allow usages beyond the scope of spec - here RAM usage,
1719 one that would help mostly the developer.
1721 CONFIG_SYS_DFU_DATA_BUF_SIZE
1722 Dfu transfer uses a buffer before writing data to the
1723 raw storage device. Make the size (in bytes) of this buffer
1724 configurable. The size of this buffer is also configurable
1725 through the "dfu_bufsiz" environment variable.
1727 CONFIG_SYS_DFU_MAX_FILE_SIZE
1728 When updating files rather than the raw storage device,
1729 we use a static buffer to copy the file into and then write
1730 the buffer once we've been given the whole file. Define
1731 this to the maximum filesize (in bytes) for the buffer.
1732 Default is 4 MiB if undefined.
1734 DFU_DEFAULT_POLL_TIMEOUT
1735 Poll timeout [ms], is the timeout a device can send to the
1736 host. The host must wait for this timeout before sending
1737 a subsequent DFU_GET_STATUS request to the device.
1739 DFU_MANIFEST_POLL_TIMEOUT
1740 Poll timeout [ms], which the device sends to the host when
1741 entering dfuMANIFEST state. Host waits this timeout, before
1742 sending again an USB request to the device.
1744 - USB Device Android Fastboot support:
1746 This enables the command "fastboot" which enables the Android
1747 fastboot mode for the platform's USB device. Fastboot is a USB
1748 protocol for downloading images, flashing and device control
1749 used on Android devices.
1750 See doc/README.android-fastboot for more information.
1752 CONFIG_ANDROID_BOOT_IMAGE
1753 This enables support for booting images which use the Android
1754 image format header.
1756 CONFIG_USB_FASTBOOT_BUF_ADDR
1757 The fastboot protocol requires a large memory buffer for
1758 downloads. Define this to the starting RAM address to use for
1761 CONFIG_USB_FASTBOOT_BUF_SIZE
1762 The fastboot protocol requires a large memory buffer for
1763 downloads. This buffer should be as large as possible for a
1764 platform. Define this to the size available RAM for fastboot.
1766 CONFIG_FASTBOOT_FLASH
1767 The fastboot protocol includes a "flash" command for writing
1768 the downloaded image to a non-volatile storage device. Define
1769 this to enable the "fastboot flash" command.
1771 CONFIG_FASTBOOT_FLASH_MMC_DEV
1772 The fastboot "flash" command requires additional information
1773 regarding the non-volatile storage device. Define this to
1774 the eMMC device that fastboot should use to store the image.
1776 - Journaling Flash filesystem support:
1777 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1778 CONFIG_JFFS2_NAND_DEV
1779 Define these for a default partition on a NAND device
1781 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1782 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1783 Define these for a default partition on a NOR device
1785 CONFIG_SYS_JFFS_CUSTOM_PART
1786 Define this to create an own partition. You have to provide a
1787 function struct part_info* jffs2_part_info(int part_num)
1789 If you define only one JFFS2 partition you may also want to
1790 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1791 to disable the command chpart. This is the default when you
1792 have not defined a custom partition
1794 - FAT(File Allocation Table) filesystem write function support:
1797 Define this to enable support for saving memory data as a
1798 file in FAT formatted partition.
1800 This will also enable the command "fatwrite" enabling the
1801 user to write files to FAT.
1803 CBFS (Coreboot Filesystem) support
1806 Define this to enable support for reading from a Coreboot
1807 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1810 - FAT(File Allocation Table) filesystem cluster size:
1811 CONFIG_FS_FAT_MAX_CLUSTSIZE
1813 Define the max cluster size for fat operations else
1814 a default value of 65536 will be defined.
1819 Define this to enable standard (PC-Style) keyboard
1823 Standard PC keyboard driver with US (is default) and
1824 GERMAN key layout (switch via environment 'keymap=de') support.
1825 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1826 for cfb_console. Supports cursor blinking.
1829 Enables a Chrome OS keyboard using the CROS_EC interface.
1830 This uses CROS_EC to communicate with a second microcontroller
1831 which provides key scans on request.
1836 Define this to enable video support (for output to
1839 CONFIG_VIDEO_CT69000
1841 Enable Chips & Technologies 69000 Video chip
1843 CONFIG_VIDEO_SMI_LYNXEM
1844 Enable Silicon Motion SMI 712/710/810 Video chip. The
1845 video output is selected via environment 'videoout'
1846 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1849 For the CT69000 and SMI_LYNXEM drivers, videomode is
1850 selected via environment 'videomode'. Two different ways
1852 - "videomode=num" 'num' is a standard LiLo mode numbers.
1853 Following standard modes are supported (* is default):
1855 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1856 -------------+---------------------------------------------
1857 8 bits | 0x301* 0x303 0x305 0x161 0x307
1858 15 bits | 0x310 0x313 0x316 0x162 0x319
1859 16 bits | 0x311 0x314 0x317 0x163 0x31A
1860 24 bits | 0x312 0x315 0x318 ? 0x31B
1861 -------------+---------------------------------------------
1862 (i.e. setenv videomode 317; saveenv; reset;)
1864 - "videomode=bootargs" all the video parameters are parsed
1865 from the bootargs. (See drivers/video/videomodes.c)
1868 CONFIG_VIDEO_SED13806
1869 Enable Epson SED13806 driver. This driver supports 8bpp
1870 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1871 or CONFIG_VIDEO_SED13806_16BPP
1874 Enable the Freescale DIU video driver. Reference boards for
1875 SOCs that have a DIU should define this macro to enable DIU
1876 support, and should also define these other macros:
1882 CONFIG_VIDEO_SW_CURSOR
1883 CONFIG_VGA_AS_SINGLE_DEVICE
1885 CONFIG_VIDEO_BMP_LOGO
1887 The DIU driver will look for the 'video-mode' environment
1888 variable, and if defined, enable the DIU as a console during
1889 boot. See the documentation file README.video for a
1890 description of this variable.
1894 Enable the VGA video / BIOS for x86. The alternative if you
1895 are using coreboot is to use the coreboot frame buffer
1902 Define this to enable a custom keyboard support.
1903 This simply calls drv_keyboard_init() which must be
1904 defined in your board-specific files.
1905 The only board using this so far is RBC823.
1907 - LCD Support: CONFIG_LCD
1909 Define this to enable LCD support (for output to LCD
1910 display); also select one of the supported displays
1911 by defining one of these:
1915 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1917 CONFIG_NEC_NL6448AC33:
1919 NEC NL6448AC33-18. Active, color, single scan.
1921 CONFIG_NEC_NL6448BC20
1923 NEC NL6448BC20-08. 6.5", 640x480.
1924 Active, color, single scan.
1926 CONFIG_NEC_NL6448BC33_54
1928 NEC NL6448BC33-54. 10.4", 640x480.
1929 Active, color, single scan.
1933 Sharp 320x240. Active, color, single scan.
1934 It isn't 16x9, and I am not sure what it is.
1936 CONFIG_SHARP_LQ64D341
1938 Sharp LQ64D341 display, 640x480.
1939 Active, color, single scan.
1943 HLD1045 display, 640x480.
1944 Active, color, single scan.
1948 Optrex CBL50840-2 NF-FW 99 22 M5
1950 Hitachi LMG6912RPFC-00T
1954 320x240. Black & white.
1956 Normally display is black on white background; define
1957 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1959 CONFIG_LCD_ALIGNMENT
1961 Normally the LCD is page-aligned (tyically 4KB). If this is
1962 defined then the LCD will be aligned to this value instead.
1963 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1964 here, since it is cheaper to change data cache settings on
1965 a per-section basis.
1967 CONFIG_CONSOLE_SCROLL_LINES
1969 When the console need to be scrolled, this is the number of
1970 lines to scroll by. It defaults to 1. Increasing this makes
1971 the console jump but can help speed up operation when scrolling
1976 Support drawing of RLE8-compressed bitmaps on the LCD.
1980 Enables an 'i2c edid' command which can read EDID
1981 information over I2C from an attached LCD display.
1983 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1985 If this option is set, the environment is checked for
1986 a variable "splashimage". If found, the usual display
1987 of logo, copyright and system information on the LCD
1988 is suppressed and the BMP image at the address
1989 specified in "splashimage" is loaded instead. The
1990 console is redirected to the "nulldev", too. This
1991 allows for a "silent" boot where a splash screen is
1992 loaded very quickly after power-on.
1994 CONFIG_SPLASHIMAGE_GUARD
1996 If this option is set, then U-Boot will prevent the environment
1997 variable "splashimage" from being set to a problematic address
1998 (see README.displaying-bmps).
1999 This option is useful for targets where, due to alignment
2000 restrictions, an improperly aligned BMP image will cause a data
2001 abort. If you think you will not have problems with unaligned
2002 accesses (for example because your toolchain prevents them)
2003 there is no need to set this option.
2005 CONFIG_SPLASH_SCREEN_ALIGN
2007 If this option is set the splash image can be freely positioned
2008 on the screen. Environment variable "splashpos" specifies the
2009 position as "x,y". If a positive number is given it is used as
2010 number of pixel from left/top. If a negative number is given it
2011 is used as number of pixel from right/bottom. You can also
2012 specify 'm' for centering the image.
2015 setenv splashpos m,m
2016 => image at center of screen
2018 setenv splashpos 30,20
2019 => image at x = 30 and y = 20
2021 setenv splashpos -10,m
2022 => vertically centered image
2023 at x = dspWidth - bmpWidth - 9
2025 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2027 If this option is set, additionally to standard BMP
2028 images, gzipped BMP images can be displayed via the
2029 splashscreen support or the bmp command.
2031 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2033 If this option is set, 8-bit RLE compressed BMP images
2034 can be displayed via the splashscreen support or the
2037 - Do compresssing for memory range:
2040 If this option is set, it would use zlib deflate method
2041 to compress the specified memory at its best effort.
2043 - Compression support:
2046 Enabled by default to support gzip compressed images.
2050 If this option is set, support for bzip2 compressed
2051 images is included. If not, only uncompressed and gzip
2052 compressed images are supported.
2054 NOTE: the bzip2 algorithm requires a lot of RAM, so
2055 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2060 If this option is set, support for lzma compressed
2063 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2064 requires an amount of dynamic memory that is given by the
2067 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2069 Where lc and lp stand for, respectively, Literal context bits
2070 and Literal pos bits.
2072 This value is upper-bounded by 14MB in the worst case. Anyway,
2073 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2074 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2075 a very small buffer.
2077 Use the lzmainfo tool to determinate the lc and lp values and
2078 then calculate the amount of needed dynamic memory (ensuring
2079 the appropriate CONFIG_SYS_MALLOC_LEN value).
2083 If this option is set, support for LZO compressed images
2089 The address of PHY on MII bus.
2091 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2093 The clock frequency of the MII bus
2097 If this option is set, support for speed/duplex
2098 detection of gigabit PHY is included.
2100 CONFIG_PHY_RESET_DELAY
2102 Some PHY like Intel LXT971A need extra delay after
2103 reset before any MII register access is possible.
2104 For such PHY, set this option to the usec delay
2105 required. (minimum 300usec for LXT971A)
2107 CONFIG_PHY_CMD_DELAY (ppc4xx)
2109 Some PHY like Intel LXT971A need extra delay after
2110 command issued before MII status register can be read
2120 Define a default value for Ethernet address to use
2121 for the respective Ethernet interface, in case this
2122 is not determined automatically.
2127 Define a default value for the IP address to use for
2128 the default Ethernet interface, in case this is not
2129 determined through e.g. bootp.
2130 (Environment variable "ipaddr")
2132 - Server IP address:
2135 Defines a default value for the IP address of a TFTP
2136 server to contact when using the "tftboot" command.
2137 (Environment variable "serverip")
2139 CONFIG_KEEP_SERVERADDR
2141 Keeps the server's MAC address, in the env 'serveraddr'
2142 for passing to bootargs (like Linux's netconsole option)
2144 - Gateway IP address:
2147 Defines a default value for the IP address of the
2148 default router where packets to other networks are
2150 (Environment variable "gatewayip")
2155 Defines a default value for the subnet mask (or
2156 routing prefix) which is used to determine if an IP
2157 address belongs to the local subnet or needs to be
2158 forwarded through a router.
2159 (Environment variable "netmask")
2161 - Multicast TFTP Mode:
2164 Defines whether you want to support multicast TFTP as per
2165 rfc-2090; for example to work with atftp. Lets lots of targets
2166 tftp down the same boot image concurrently. Note: the Ethernet
2167 driver in use must provide a function: mcast() to join/leave a
2170 - BOOTP Recovery Mode:
2171 CONFIG_BOOTP_RANDOM_DELAY
2173 If you have many targets in a network that try to
2174 boot using BOOTP, you may want to avoid that all
2175 systems send out BOOTP requests at precisely the same
2176 moment (which would happen for instance at recovery
2177 from a power failure, when all systems will try to
2178 boot, thus flooding the BOOTP server. Defining
2179 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2180 inserted before sending out BOOTP requests. The
2181 following delays are inserted then:
2183 1st BOOTP request: delay 0 ... 1 sec
2184 2nd BOOTP request: delay 0 ... 2 sec
2185 3rd BOOTP request: delay 0 ... 4 sec
2187 BOOTP requests: delay 0 ... 8 sec
2189 CONFIG_BOOTP_ID_CACHE_SIZE
2191 BOOTP packets are uniquely identified using a 32-bit ID. The
2192 server will copy the ID from client requests to responses and
2193 U-Boot will use this to determine if it is the destination of
2194 an incoming response. Some servers will check that addresses
2195 aren't in use before handing them out (usually using an ARP
2196 ping) and therefore take up to a few hundred milliseconds to
2197 respond. Network congestion may also influence the time it
2198 takes for a response to make it back to the client. If that
2199 time is too long, U-Boot will retransmit requests. In order
2200 to allow earlier responses to still be accepted after these
2201 retransmissions, U-Boot's BOOTP client keeps a small cache of
2202 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2203 cache. The default is to keep IDs for up to four outstanding
2204 requests. Increasing this will allow U-Boot to accept offers
2205 from a BOOTP client in networks with unusually high latency.
2207 - DHCP Advanced Options:
2208 You can fine tune the DHCP functionality by defining
2209 CONFIG_BOOTP_* symbols:
2211 CONFIG_BOOTP_SUBNETMASK
2212 CONFIG_BOOTP_GATEWAY
2213 CONFIG_BOOTP_HOSTNAME
2214 CONFIG_BOOTP_NISDOMAIN
2215 CONFIG_BOOTP_BOOTPATH
2216 CONFIG_BOOTP_BOOTFILESIZE
2219 CONFIG_BOOTP_SEND_HOSTNAME
2220 CONFIG_BOOTP_NTPSERVER
2221 CONFIG_BOOTP_TIMEOFFSET
2222 CONFIG_BOOTP_VENDOREX
2223 CONFIG_BOOTP_MAY_FAIL
2225 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2226 environment variable, not the BOOTP server.
2228 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2229 after the configured retry count, the call will fail
2230 instead of starting over. This can be used to fail over
2231 to Link-local IP address configuration if the DHCP server
2234 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2235 serverip from a DHCP server, it is possible that more
2236 than one DNS serverip is offered to the client.
2237 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2238 serverip will be stored in the additional environment
2239 variable "dnsip2". The first DNS serverip is always
2240 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2243 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2244 to do a dynamic update of a DNS server. To do this, they
2245 need the hostname of the DHCP requester.
2246 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2247 of the "hostname" environment variable is passed as
2248 option 12 to the DHCP server.
2250 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2252 A 32bit value in microseconds for a delay between
2253 receiving a "DHCP Offer" and sending the "DHCP Request".
2254 This fixes a problem with certain DHCP servers that don't
2255 respond 100% of the time to a "DHCP request". E.g. On an
2256 AT91RM9200 processor running at 180MHz, this delay needed
2257 to be *at least* 15,000 usec before a Windows Server 2003
2258 DHCP server would reply 100% of the time. I recommend at
2259 least 50,000 usec to be safe. The alternative is to hope
2260 that one of the retries will be successful but note that
2261 the DHCP timeout and retry process takes a longer than
2264 - Link-local IP address negotiation:
2265 Negotiate with other link-local clients on the local network
2266 for an address that doesn't require explicit configuration.
2267 This is especially useful if a DHCP server cannot be guaranteed
2268 to exist in all environments that the device must operate.
2270 See doc/README.link-local for more information.
2273 CONFIG_CDP_DEVICE_ID
2275 The device id used in CDP trigger frames.
2277 CONFIG_CDP_DEVICE_ID_PREFIX
2279 A two character string which is prefixed to the MAC address
2284 A printf format string which contains the ascii name of
2285 the port. Normally is set to "eth%d" which sets
2286 eth0 for the first Ethernet, eth1 for the second etc.
2288 CONFIG_CDP_CAPABILITIES
2290 A 32bit integer which indicates the device capabilities;
2291 0x00000010 for a normal host which does not forwards.
2295 An ascii string containing the version of the software.
2299 An ascii string containing the name of the platform.
2303 A 32bit integer sent on the trigger.
2305 CONFIG_CDP_POWER_CONSUMPTION
2307 A 16bit integer containing the power consumption of the
2308 device in .1 of milliwatts.
2310 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2312 A byte containing the id of the VLAN.
2314 - Status LED: CONFIG_STATUS_LED
2316 Several configurations allow to display the current
2317 status using a LED. For instance, the LED will blink
2318 fast while running U-Boot code, stop blinking as
2319 soon as a reply to a BOOTP request was received, and
2320 start blinking slow once the Linux kernel is running
2321 (supported by a status LED driver in the Linux
2322 kernel). Defining CONFIG_STATUS_LED enables this
2328 The status LED can be connected to a GPIO pin.
2329 In such cases, the gpio_led driver can be used as a
2330 status LED backend implementation. Define CONFIG_GPIO_LED
2331 to include the gpio_led driver in the U-Boot binary.
2333 CONFIG_GPIO_LED_INVERTED_TABLE
2334 Some GPIO connected LEDs may have inverted polarity in which
2335 case the GPIO high value corresponds to LED off state and
2336 GPIO low value corresponds to LED on state.
2337 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2338 with a list of GPIO LEDs that have inverted polarity.
2340 - CAN Support: CONFIG_CAN_DRIVER
2342 Defining CONFIG_CAN_DRIVER enables CAN driver support
2343 on those systems that support this (optional)
2344 feature, like the TQM8xxL modules.
2346 - I2C Support: CONFIG_SYS_I2C
2348 This enable the NEW i2c subsystem, and will allow you to use
2349 i2c commands at the u-boot command line (as long as you set
2350 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2351 based realtime clock chips or other i2c devices. See
2352 common/cmd_i2c.c for a description of the command line
2355 ported i2c driver to the new framework:
2356 - drivers/i2c/soft_i2c.c:
2357 - activate first bus with CONFIG_SYS_I2C_SOFT define
2358 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2359 for defining speed and slave address
2360 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2361 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2362 for defining speed and slave address
2363 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2364 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2365 for defining speed and slave address
2366 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2367 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2368 for defining speed and slave address
2370 - drivers/i2c/fsl_i2c.c:
2371 - activate i2c driver with CONFIG_SYS_I2C_FSL
2372 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2373 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2374 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2376 - If your board supports a second fsl i2c bus, define
2377 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2378 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2379 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2382 - drivers/i2c/tegra_i2c.c:
2383 - activate this driver with CONFIG_SYS_I2C_TEGRA
2384 - This driver adds 4 i2c buses with a fix speed from
2385 100000 and the slave addr 0!
2387 - drivers/i2c/ppc4xx_i2c.c
2388 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2389 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2390 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2392 - drivers/i2c/i2c_mxc.c
2393 - activate this driver with CONFIG_SYS_I2C_MXC
2394 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2395 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2396 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2397 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2398 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2399 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2400 If thoses defines are not set, default value is 100000
2401 for speed, and 0 for slave.
2403 - drivers/i2c/rcar_i2c.c:
2404 - activate this driver with CONFIG_SYS_I2C_RCAR
2405 - This driver adds 4 i2c buses
2407 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2408 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2409 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2410 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2411 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2412 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2413 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2414 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2415 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2417 - drivers/i2c/sh_i2c.c:
2418 - activate this driver with CONFIG_SYS_I2C_SH
2419 - This driver adds from 2 to 5 i2c buses
2421 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2422 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2423 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2424 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2425 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2426 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2427 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2428 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2429 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2430 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2431 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2432 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2433 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2435 - drivers/i2c/omap24xx_i2c.c
2436 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2437 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2438 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2439 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2440 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2441 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2442 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2443 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2444 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2445 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2446 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2448 - drivers/i2c/zynq_i2c.c
2449 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2450 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2451 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2453 - drivers/i2c/s3c24x0_i2c.c:
2454 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2455 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2456 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2457 with a fix speed from 100000 and the slave addr 0!
2459 - drivers/i2c/ihs_i2c.c
2460 - activate this driver with CONFIG_SYS_I2C_IHS
2461 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2462 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2463 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2464 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2465 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2466 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2467 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2468 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2469 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2470 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2471 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2472 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2476 CONFIG_SYS_NUM_I2C_BUSES
2477 Hold the number of i2c busses you want to use. If you
2478 don't use/have i2c muxes on your i2c bus, this
2479 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2482 CONFIG_SYS_I2C_DIRECT_BUS
2483 define this, if you don't use i2c muxes on your hardware.
2484 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2487 CONFIG_SYS_I2C_MAX_HOPS
2488 define how many muxes are maximal consecutively connected
2489 on one i2c bus. If you not use i2c muxes, omit this
2492 CONFIG_SYS_I2C_BUSES
2493 hold a list of busses you want to use, only used if
2494 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2495 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2496 CONFIG_SYS_NUM_I2C_BUSES = 9:
2498 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2499 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2500 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2501 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2502 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2503 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2504 {1, {I2C_NULL_HOP}}, \
2505 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2506 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2510 bus 0 on adapter 0 without a mux
2511 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2512 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2513 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2514 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2515 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2516 bus 6 on adapter 1 without a mux
2517 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2518 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2520 If you do not have i2c muxes on your board, omit this define.
2522 - Legacy I2C Support: CONFIG_HARD_I2C
2524 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2525 provides the following compelling advantages:
2527 - more than one i2c adapter is usable
2528 - approved multibus support
2529 - better i2c mux support
2531 ** Please consider updating your I2C driver now. **
2533 These enable legacy I2C serial bus commands. Defining
2534 CONFIG_HARD_I2C will include the appropriate I2C driver
2535 for the selected CPU.
2537 This will allow you to use i2c commands at the u-boot
2538 command line (as long as you set CONFIG_CMD_I2C in
2539 CONFIG_COMMANDS) and communicate with i2c based realtime
2540 clock chips. See common/cmd_i2c.c for a description of the
2541 command line interface.
2543 CONFIG_HARD_I2C selects a hardware I2C controller.
2545 There are several other quantities that must also be
2546 defined when you define CONFIG_HARD_I2C.
2548 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2549 to be the frequency (in Hz) at which you wish your i2c bus
2550 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2551 the CPU's i2c node address).
2553 Now, the u-boot i2c code for the mpc8xx
2554 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2555 and so its address should therefore be cleared to 0 (See,
2556 eg, MPC823e User's Manual p.16-473). So, set
2557 CONFIG_SYS_I2C_SLAVE to 0.
2559 CONFIG_SYS_I2C_INIT_MPC5XXX
2561 When a board is reset during an i2c bus transfer
2562 chips might think that the current transfer is still
2563 in progress. Reset the slave devices by sending start
2564 commands until the slave device responds.
2566 That's all that's required for CONFIG_HARD_I2C.
2568 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2569 then the following macros need to be defined (examples are
2570 from include/configs/lwmon.h):
2574 (Optional). Any commands necessary to enable the I2C
2575 controller or configure ports.
2577 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2581 (Only for MPC8260 CPU). The I/O port to use (the code
2582 assumes both bits are on the same port). Valid values
2583 are 0..3 for ports A..D.
2587 The code necessary to make the I2C data line active
2588 (driven). If the data line is open collector, this
2591 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2595 The code necessary to make the I2C data line tri-stated
2596 (inactive). If the data line is open collector, this
2599 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2603 Code that returns true if the I2C data line is high,
2606 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2610 If <bit> is true, sets the I2C data line high. If it
2611 is false, it clears it (low).
2613 eg: #define I2C_SDA(bit) \
2614 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2615 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2619 If <bit> is true, sets the I2C clock line high. If it
2620 is false, it clears it (low).
2622 eg: #define I2C_SCL(bit) \
2623 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2624 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2628 This delay is invoked four times per clock cycle so this
2629 controls the rate of data transfer. The data rate thus
2630 is 1 / (I2C_DELAY * 4). Often defined to be something
2633 #define I2C_DELAY udelay(2)
2635 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2637 If your arch supports the generic GPIO framework (asm/gpio.h),
2638 then you may alternatively define the two GPIOs that are to be
2639 used as SCL / SDA. Any of the previous I2C_xxx macros will
2640 have GPIO-based defaults assigned to them as appropriate.
2642 You should define these to the GPIO value as given directly to
2643 the generic GPIO functions.
2645 CONFIG_SYS_I2C_INIT_BOARD
2647 When a board is reset during an i2c bus transfer
2648 chips might think that the current transfer is still
2649 in progress. On some boards it is possible to access
2650 the i2c SCLK line directly, either by using the
2651 processor pin as a GPIO or by having a second pin
2652 connected to the bus. If this option is defined a
2653 custom i2c_init_board() routine in boards/xxx/board.c
2654 is run early in the boot sequence.
2656 CONFIG_SYS_I2C_BOARD_LATE_INIT
2658 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2659 defined a custom i2c_board_late_init() routine in
2660 boards/xxx/board.c is run AFTER the operations in i2c_init()
2661 is completed. This callpoint can be used to unreset i2c bus
2662 using CPU i2c controller register accesses for CPUs whose i2c
2663 controller provide such a method. It is called at the end of
2664 i2c_init() to allow i2c_init operations to setup the i2c bus
2665 controller on the CPU (e.g. setting bus speed & slave address).
2667 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2669 This option enables configuration of bi_iic_fast[] flags
2670 in u-boot bd_info structure based on u-boot environment
2671 variable "i2cfast". (see also i2cfast)
2673 CONFIG_I2C_MULTI_BUS
2675 This option allows the use of multiple I2C buses, each of which
2676 must have a controller. At any point in time, only one bus is
2677 active. To switch to a different bus, use the 'i2c dev' command.
2678 Note that bus numbering is zero-based.
2680 CONFIG_SYS_I2C_NOPROBES
2682 This option specifies a list of I2C devices that will be skipped
2683 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2684 is set, specify a list of bus-device pairs. Otherwise, specify
2685 a 1D array of device addresses
2688 #undef CONFIG_I2C_MULTI_BUS
2689 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2691 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2693 #define CONFIG_I2C_MULTI_BUS
2694 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2696 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2698 CONFIG_SYS_SPD_BUS_NUM
2700 If defined, then this indicates the I2C bus number for DDR SPD.
2701 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2703 CONFIG_SYS_RTC_BUS_NUM
2705 If defined, then this indicates the I2C bus number for the RTC.
2706 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2708 CONFIG_SYS_DTT_BUS_NUM
2710 If defined, then this indicates the I2C bus number for the DTT.
2711 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2713 CONFIG_SYS_I2C_DTT_ADDR:
2715 If defined, specifies the I2C address of the DTT device.
2716 If not defined, then U-Boot uses predefined value for
2717 specified DTT device.
2719 CONFIG_SOFT_I2C_READ_REPEATED_START
2721 defining this will force the i2c_read() function in
2722 the soft_i2c driver to perform an I2C repeated start
2723 between writing the address pointer and reading the
2724 data. If this define is omitted the default behaviour
2725 of doing a stop-start sequence will be used. Most I2C
2726 devices can use either method, but some require one or
2729 - SPI Support: CONFIG_SPI
2731 Enables SPI driver (so far only tested with
2732 SPI EEPROM, also an instance works with Crystal A/D and
2733 D/As on the SACSng board)
2737 Enables the driver for SPI controller on SuperH. Currently
2738 only SH7757 is supported.
2742 Enables extended (16-bit) SPI EEPROM addressing.
2743 (symmetrical to CONFIG_I2C_X)
2747 Enables a software (bit-bang) SPI driver rather than
2748 using hardware support. This is a general purpose
2749 driver that only requires three general I/O port pins
2750 (two outputs, one input) to function. If this is
2751 defined, the board configuration must define several
2752 SPI configuration items (port pins to use, etc). For
2753 an example, see include/configs/sacsng.h.
2757 Enables a hardware SPI driver for general-purpose reads
2758 and writes. As with CONFIG_SOFT_SPI, the board configuration
2759 must define a list of chip-select function pointers.
2760 Currently supported on some MPC8xxx processors. For an
2761 example, see include/configs/mpc8349emds.h.
2765 Enables the driver for the SPI controllers on i.MX and MXC
2766 SoCs. Currently i.MX31/35/51 are supported.
2768 CONFIG_SYS_SPI_MXC_WAIT
2769 Timeout for waiting until spi transfer completed.
2770 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2772 - FPGA Support: CONFIG_FPGA
2774 Enables FPGA subsystem.
2776 CONFIG_FPGA_<vendor>
2778 Enables support for specific chip vendors.
2781 CONFIG_FPGA_<family>
2783 Enables support for FPGA family.
2784 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2788 Specify the number of FPGA devices to support.
2790 CONFIG_CMD_FPGA_LOADMK
2792 Enable support for fpga loadmk command
2794 CONFIG_CMD_FPGA_LOADP
2796 Enable support for fpga loadp command - load partial bitstream
2798 CONFIG_CMD_FPGA_LOADBP
2800 Enable support for fpga loadbp command - load partial bitstream
2803 CONFIG_SYS_FPGA_PROG_FEEDBACK
2805 Enable printing of hash marks during FPGA configuration.
2807 CONFIG_SYS_FPGA_CHECK_BUSY
2809 Enable checks on FPGA configuration interface busy
2810 status by the configuration function. This option
2811 will require a board or device specific function to
2816 If defined, a function that provides delays in the FPGA
2817 configuration driver.
2819 CONFIG_SYS_FPGA_CHECK_CTRLC
2820 Allow Control-C to interrupt FPGA configuration
2822 CONFIG_SYS_FPGA_CHECK_ERROR
2824 Check for configuration errors during FPGA bitfile
2825 loading. For example, abort during Virtex II
2826 configuration if the INIT_B line goes low (which
2827 indicated a CRC error).
2829 CONFIG_SYS_FPGA_WAIT_INIT
2831 Maximum time to wait for the INIT_B line to deassert
2832 after PROB_B has been deasserted during a Virtex II
2833 FPGA configuration sequence. The default time is 500
2836 CONFIG_SYS_FPGA_WAIT_BUSY
2838 Maximum time to wait for BUSY to deassert during
2839 Virtex II FPGA configuration. The default is 5 ms.
2841 CONFIG_SYS_FPGA_WAIT_CONFIG
2843 Time to wait after FPGA configuration. The default is
2846 - Configuration Management:
2849 Some SoCs need special image types (e.g. U-Boot binary
2850 with a special header) as build targets. By defining
2851 CONFIG_BUILD_TARGET in the SoC / board header, this
2852 special image will be automatically built upon calling
2857 If defined, this string will be added to the U-Boot
2858 version information (U_BOOT_VERSION)
2860 - Vendor Parameter Protection:
2862 U-Boot considers the values of the environment
2863 variables "serial#" (Board Serial Number) and
2864 "ethaddr" (Ethernet Address) to be parameters that
2865 are set once by the board vendor / manufacturer, and
2866 protects these variables from casual modification by
2867 the user. Once set, these variables are read-only,
2868 and write or delete attempts are rejected. You can
2869 change this behaviour:
2871 If CONFIG_ENV_OVERWRITE is #defined in your config
2872 file, the write protection for vendor parameters is
2873 completely disabled. Anybody can change or delete
2876 Alternatively, if you #define _both_ CONFIG_ETHADDR
2877 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2878 Ethernet address is installed in the environment,
2879 which can be changed exactly ONCE by the user. [The
2880 serial# is unaffected by this, i. e. it remains
2883 The same can be accomplished in a more flexible way
2884 for any variable by configuring the type of access
2885 to allow for those variables in the ".flags" variable
2886 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2891 Define this variable to enable the reservation of
2892 "protected RAM", i. e. RAM which is not overwritten
2893 by U-Boot. Define CONFIG_PRAM to hold the number of
2894 kB you want to reserve for pRAM. You can overwrite
2895 this default value by defining an environment
2896 variable "pram" to the number of kB you want to
2897 reserve. Note that the board info structure will
2898 still show the full amount of RAM. If pRAM is
2899 reserved, a new environment variable "mem" will
2900 automatically be defined to hold the amount of
2901 remaining RAM in a form that can be passed as boot
2902 argument to Linux, for instance like that:
2904 setenv bootargs ... mem=\${mem}
2907 This way you can tell Linux not to use this memory,
2908 either, which results in a memory region that will
2909 not be affected by reboots.
2911 *WARNING* If your board configuration uses automatic
2912 detection of the RAM size, you must make sure that
2913 this memory test is non-destructive. So far, the
2914 following board configurations are known to be
2917 IVMS8, IVML24, SPD8xx, TQM8xxL,
2918 HERMES, IP860, RPXlite, LWMON,
2921 - Access to physical memory region (> 4GB)
2922 Some basic support is provided for operations on memory not
2923 normally accessible to U-Boot - e.g. some architectures
2924 support access to more than 4GB of memory on 32-bit
2925 machines using physical address extension or similar.
2926 Define CONFIG_PHYSMEM to access this basic support, which
2927 currently only supports clearing the memory.
2932 Define this variable to stop the system in case of a
2933 fatal error, so that you have to reset it manually.
2934 This is probably NOT a good idea for an embedded
2935 system where you want the system to reboot
2936 automatically as fast as possible, but it may be
2937 useful during development since you can try to debug
2938 the conditions that lead to the situation.
2940 CONFIG_NET_RETRY_COUNT
2942 This variable defines the number of retries for
2943 network operations like ARP, RARP, TFTP, or BOOTP
2944 before giving up the operation. If not defined, a
2945 default value of 5 is used.
2949 Timeout waiting for an ARP reply in milliseconds.
2953 Timeout in milliseconds used in NFS protocol.
2954 If you encounter "ERROR: Cannot umount" in nfs command,
2955 try longer timeout such as
2956 #define CONFIG_NFS_TIMEOUT 10000UL
2958 - Command Interpreter:
2959 CONFIG_AUTO_COMPLETE
2961 Enable auto completion of commands using TAB.
2963 CONFIG_SYS_PROMPT_HUSH_PS2
2965 This defines the secondary prompt string, which is
2966 printed when the command interpreter needs more input
2967 to complete a command. Usually "> ".
2971 In the current implementation, the local variables
2972 space and global environment variables space are
2973 separated. Local variables are those you define by
2974 simply typing `name=value'. To access a local
2975 variable later on, you have write `$name' or
2976 `${name}'; to execute the contents of a variable
2977 directly type `$name' at the command prompt.
2979 Global environment variables are those you use
2980 setenv/printenv to work with. To run a command stored
2981 in such a variable, you need to use the run command,
2982 and you must not use the '$' sign to access them.
2984 To store commands and special characters in a
2985 variable, please use double quotation marks
2986 surrounding the whole text of the variable, instead
2987 of the backslashes before semicolons and special
2990 - Commandline Editing and History:
2991 CONFIG_CMDLINE_EDITING
2993 Enable editing and History functions for interactive
2994 commandline input operations
2996 - Default Environment:
2997 CONFIG_EXTRA_ENV_SETTINGS
2999 Define this to contain any number of null terminated
3000 strings (variable = value pairs) that will be part of
3001 the default environment compiled into the boot image.
3003 For example, place something like this in your
3004 board's config file:
3006 #define CONFIG_EXTRA_ENV_SETTINGS \
3010 Warning: This method is based on knowledge about the
3011 internal format how the environment is stored by the
3012 U-Boot code. This is NOT an official, exported
3013 interface! Although it is unlikely that this format
3014 will change soon, there is no guarantee either.
3015 You better know what you are doing here.
3017 Note: overly (ab)use of the default environment is
3018 discouraged. Make sure to check other ways to preset
3019 the environment like the "source" command or the
3022 CONFIG_ENV_VARS_UBOOT_CONFIG
3024 Define this in order to add variables describing the
3025 U-Boot build configuration to the default environment.
3026 These will be named arch, cpu, board, vendor, and soc.
3028 Enabling this option will cause the following to be defined:
3036 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3038 Define this in order to add variables describing certain
3039 run-time determined information about the hardware to the
3040 environment. These will be named board_name, board_rev.
3042 CONFIG_DELAY_ENVIRONMENT
3044 Normally the environment is loaded when the board is
3045 intialised so that it is available to U-Boot. This inhibits
3046 that so that the environment is not available until
3047 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3048 this is instead controlled by the value of
3049 /config/load-environment.
3051 - DataFlash Support:
3052 CONFIG_HAS_DATAFLASH
3054 Defining this option enables DataFlash features and
3055 allows to read/write in Dataflash via the standard
3058 - Serial Flash support
3061 Defining this option enables SPI flash commands
3062 'sf probe/read/write/erase/update'.
3064 Usage requires an initial 'probe' to define the serial
3065 flash parameters, followed by read/write/erase/update
3068 The following defaults may be provided by the platform
3069 to handle the common case when only a single serial
3070 flash is present on the system.
3072 CONFIG_SF_DEFAULT_BUS Bus identifier
3073 CONFIG_SF_DEFAULT_CS Chip-select
3074 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3075 CONFIG_SF_DEFAULT_SPEED in Hz
3079 Define this option to include a destructive SPI flash
3082 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3084 Define this option to use the Bank addr/Extended addr
3085 support on SPI flashes which has size > 16Mbytes.
3087 CONFIG_SF_DUAL_FLASH Dual flash memories
3089 Define this option to use dual flash support where two flash
3090 memories can be connected with a given cs line.
3091 currently Xilinx Zynq qspi support these type of connections.
3093 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3094 enable the W#/Vpp signal to disable writing to the status
3095 register on ST MICRON flashes like the N25Q128.
3096 The status register write enable/disable bit, combined with
3097 the W#/VPP signal provides hardware data protection for the
3098 device as follows: When the enable/disable bit is set to 1,
3099 and the W#/VPP signal is driven LOW, the status register
3100 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3101 operation will not execute. The only way to exit this
3102 hardware-protected mode is to drive W#/VPP HIGH.
3104 - SystemACE Support:
3107 Adding this option adds support for Xilinx SystemACE
3108 chips attached via some sort of local bus. The address
3109 of the chip must also be defined in the
3110 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3112 #define CONFIG_SYSTEMACE
3113 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3115 When SystemACE support is added, the "ace" device type
3116 becomes available to the fat commands, i.e. fatls.
3118 - TFTP Fixed UDP Port:
3121 If this is defined, the environment variable tftpsrcp
3122 is used to supply the TFTP UDP source port value.
3123 If tftpsrcp isn't defined, the normal pseudo-random port
3124 number generator is used.
3126 Also, the environment variable tftpdstp is used to supply
3127 the TFTP UDP destination port value. If tftpdstp isn't
3128 defined, the normal port 69 is used.
3130 The purpose for tftpsrcp is to allow a TFTP server to
3131 blindly start the TFTP transfer using the pre-configured
3132 target IP address and UDP port. This has the effect of
3133 "punching through" the (Windows XP) firewall, allowing
3134 the remainder of the TFTP transfer to proceed normally.
3135 A better solution is to properly configure the firewall,
3136 but sometimes that is not allowed.
3141 This enables a generic 'hash' command which can produce
3142 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3146 Enable the hash verify command (hash -v). This adds to code
3149 CONFIG_SHA1 - support SHA1 hashing
3150 CONFIG_SHA256 - support SHA256 hashing
3152 Note: There is also a sha1sum command, which should perhaps
3153 be deprecated in favour of 'hash sha1'.
3155 - Freescale i.MX specific commands:
3156 CONFIG_CMD_HDMIDETECT
3157 This enables 'hdmidet' command which returns true if an
3158 HDMI monitor is detected. This command is i.MX 6 specific.
3161 This enables the 'bmode' (bootmode) command for forcing
3162 a boot from specific media.
3164 This is useful for forcing the ROM's usb downloader to
3165 activate upon a watchdog reset which is nice when iterating
3166 on U-Boot. Using the reset button or running bmode normal
3167 will set it back to normal. This command currently
3168 supports i.MX53 and i.MX6.
3173 This enables the RSA algorithm used for FIT image verification
3174 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3176 The signing part is build into mkimage regardless of this
3179 - bootcount support:
3180 CONFIG_BOOTCOUNT_LIMIT
3182 This enables the bootcounter support, see:
3183 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3186 enable special bootcounter support on at91sam9xe based boards.
3188 enable special bootcounter support on blackfin based boards.
3190 enable special bootcounter support on da850 based boards.
3191 CONFIG_BOOTCOUNT_RAM
3192 enable support for the bootcounter in RAM
3193 CONFIG_BOOTCOUNT_I2C
3194 enable support for the bootcounter on an i2c (like RTC) device.
3195 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3196 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3198 CONFIG_BOOTCOUNT_ALEN = address len
3200 - Show boot progress:
3201 CONFIG_SHOW_BOOT_PROGRESS
3203 Defining this option allows to add some board-
3204 specific code (calling a user-provided function
3205 "show_boot_progress(int)") that enables you to show
3206 the system's boot progress on some display (for
3207 example, some LED's) on your board. At the moment,
3208 the following checkpoints are implemented:
3210 - Detailed boot stage timing
3212 Define this option to get detailed timing of each stage
3213 of the boot process.
3215 CONFIG_BOOTSTAGE_USER_COUNT
3216 This is the number of available user bootstage records.
3217 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3218 a new ID will be allocated from this stash. If you exceed
3219 the limit, recording will stop.
3221 CONFIG_BOOTSTAGE_REPORT
3222 Define this to print a report before boot, similar to this:
3224 Timer summary in microseconds:
3227 3,575,678 3,575,678 board_init_f start
3228 3,575,695 17 arch_cpu_init A9
3229 3,575,777 82 arch_cpu_init done
3230 3,659,598 83,821 board_init_r start
3231 3,910,375 250,777 main_loop
3232 29,916,167 26,005,792 bootm_start
3233 30,361,327 445,160 start_kernel
3235 CONFIG_CMD_BOOTSTAGE
3236 Add a 'bootstage' command which supports printing a report
3237 and un/stashing of bootstage data.
3239 CONFIG_BOOTSTAGE_FDT
3240 Stash the bootstage information in the FDT. A root 'bootstage'
3241 node is created with each bootstage id as a child. Each child
3242 has a 'name' property and either 'mark' containing the
3243 mark time in microsecond, or 'accum' containing the
3244 accumulated time for that bootstage id in microseconds.
3249 name = "board_init_f";
3258 Code in the Linux kernel can find this in /proc/devicetree.
3260 Legacy uImage format:
3263 1 common/cmd_bootm.c before attempting to boot an image
3264 -1 common/cmd_bootm.c Image header has bad magic number
3265 2 common/cmd_bootm.c Image header has correct magic number
3266 -2 common/cmd_bootm.c Image header has bad checksum
3267 3 common/cmd_bootm.c Image header has correct checksum
3268 -3 common/cmd_bootm.c Image data has bad checksum
3269 4 common/cmd_bootm.c Image data has correct checksum
3270 -4 common/cmd_bootm.c Image is for unsupported architecture
3271 5 common/cmd_bootm.c Architecture check OK
3272 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3273 6 common/cmd_bootm.c Image Type check OK
3274 -6 common/cmd_bootm.c gunzip uncompression error
3275 -7 common/cmd_bootm.c Unimplemented compression type
3276 7 common/cmd_bootm.c Uncompression OK
3277 8 common/cmd_bootm.c No uncompress/copy overwrite error
3278 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3280 9 common/image.c Start initial ramdisk verification
3281 -10 common/image.c Ramdisk header has bad magic number
3282 -11 common/image.c Ramdisk header has bad checksum
3283 10 common/image.c Ramdisk header is OK
3284 -12 common/image.c Ramdisk data has bad checksum
3285 11 common/image.c Ramdisk data has correct checksum
3286 12 common/image.c Ramdisk verification complete, start loading
3287 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3288 13 common/image.c Start multifile image verification
3289 14 common/image.c No initial ramdisk, no multifile, continue.
3291 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3293 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3294 -31 post/post.c POST test failed, detected by post_output_backlog()
3295 -32 post/post.c POST test failed, detected by post_run_single()
3297 34 common/cmd_doc.c before loading a Image from a DOC device
3298 -35 common/cmd_doc.c Bad usage of "doc" command
3299 35 common/cmd_doc.c correct usage of "doc" command
3300 -36 common/cmd_doc.c No boot device
3301 36 common/cmd_doc.c correct boot device
3302 -37 common/cmd_doc.c Unknown Chip ID on boot device
3303 37 common/cmd_doc.c correct chip ID found, device available
3304 -38 common/cmd_doc.c Read Error on boot device
3305 38 common/cmd_doc.c reading Image header from DOC device OK
3306 -39 common/cmd_doc.c Image header has bad magic number
3307 39 common/cmd_doc.c Image header has correct magic number
3308 -40 common/cmd_doc.c Error reading Image from DOC device
3309 40 common/cmd_doc.c Image header has correct magic number
3310 41 common/cmd_ide.c before loading a Image from a IDE device
3311 -42 common/cmd_ide.c Bad usage of "ide" command
3312 42 common/cmd_ide.c correct usage of "ide" command
3313 -43 common/cmd_ide.c No boot device
3314 43 common/cmd_ide.c boot device found
3315 -44 common/cmd_ide.c Device not available
3316 44 common/cmd_ide.c Device available
3317 -45 common/cmd_ide.c wrong partition selected
3318 45 common/cmd_ide.c partition selected
3319 -46 common/cmd_ide.c Unknown partition table
3320 46 common/cmd_ide.c valid partition table found
3321 -47 common/cmd_ide.c Invalid partition type
3322 47 common/cmd_ide.c correct partition type
3323 -48 common/cmd_ide.c Error reading Image Header on boot device
3324 48 common/cmd_ide.c reading Image Header from IDE device OK
3325 -49 common/cmd_ide.c Image header has bad magic number
3326 49 common/cmd_ide.c Image header has correct magic number
3327 -50 common/cmd_ide.c Image header has bad checksum
3328 50 common/cmd_ide.c Image header has correct checksum
3329 -51 common/cmd_ide.c Error reading Image from IDE device
3330 51 common/cmd_ide.c reading Image from IDE device OK
3331 52 common/cmd_nand.c before loading a Image from a NAND device
3332 -53 common/cmd_nand.c Bad usage of "nand" command
3333 53 common/cmd_nand.c correct usage of "nand" command
3334 -54 common/cmd_nand.c No boot device
3335 54 common/cmd_nand.c boot device found
3336 -55 common/cmd_nand.c Unknown Chip ID on boot device
3337 55 common/cmd_nand.c correct chip ID found, device available
3338 -56 common/cmd_nand.c Error reading Image Header on boot device
3339 56 common/cmd_nand.c reading Image Header from NAND device OK
3340 -57 common/cmd_nand.c Image header has bad magic number
3341 57 common/cmd_nand.c Image header has correct magic number
3342 -58 common/cmd_nand.c Error reading Image from NAND device
3343 58 common/cmd_nand.c reading Image from NAND device OK
3345 -60 common/env_common.c Environment has a bad CRC, using default
3347 64 net/eth.c starting with Ethernet configuration.
3348 -64 net/eth.c no Ethernet found.
3349 65 net/eth.c Ethernet found.
3351 -80 common/cmd_net.c usage wrong
3352 80 common/cmd_net.c before calling NetLoop()
3353 -81 common/cmd_net.c some error in NetLoop() occurred
3354 81 common/cmd_net.c NetLoop() back without error
3355 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3356 82 common/cmd_net.c trying automatic boot
3357 83 common/cmd_net.c running "source" command
3358 -83 common/cmd_net.c some error in automatic boot or "source" command
3359 84 common/cmd_net.c end without errors
3364 100 common/cmd_bootm.c Kernel FIT Image has correct format
3365 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3366 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3367 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3368 102 common/cmd_bootm.c Kernel unit name specified
3369 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3370 103 common/cmd_bootm.c Found configuration node
3371 104 common/cmd_bootm.c Got kernel subimage node offset
3372 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3373 105 common/cmd_bootm.c Kernel subimage hash verification OK
3374 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3375 106 common/cmd_bootm.c Architecture check OK
3376 -106 common/cmd_bootm.c Kernel subimage has wrong type
3377 107 common/cmd_bootm.c Kernel subimage type OK
3378 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3379 108 common/cmd_bootm.c Got kernel subimage data/size
3380 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3381 -109 common/cmd_bootm.c Can't get kernel subimage type
3382 -110 common/cmd_bootm.c Can't get kernel subimage comp
3383 -111 common/cmd_bootm.c Can't get kernel subimage os
3384 -112 common/cmd_bootm.c Can't get kernel subimage load address
3385 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3387 120 common/image.c Start initial ramdisk verification
3388 -120 common/image.c Ramdisk FIT image has incorrect format
3389 121 common/image.c Ramdisk FIT image has correct format
3390 122 common/image.c No ramdisk subimage unit name, using configuration
3391 -122 common/image.c Can't get configuration for ramdisk subimage
3392 123 common/image.c Ramdisk unit name specified
3393 -124 common/image.c Can't get ramdisk subimage node offset
3394 125 common/image.c Got ramdisk subimage node offset
3395 -125 common/image.c Ramdisk subimage hash verification failed
3396 126 common/image.c Ramdisk subimage hash verification OK
3397 -126 common/image.c Ramdisk subimage for unsupported architecture
3398 127 common/image.c Architecture check OK
3399 -127 common/image.c Can't get ramdisk subimage data/size
3400 128 common/image.c Got ramdisk subimage data/size
3401 129 common/image.c Can't get ramdisk load address
3402 -129 common/image.c Got ramdisk load address
3404 -130 common/cmd_doc.c Incorrect FIT image format
3405 131 common/cmd_doc.c FIT image format OK
3407 -140 common/cmd_ide.c Incorrect FIT image format
3408 141 common/cmd_ide.c FIT image format OK
3410 -150 common/cmd_nand.c Incorrect FIT image format
3411 151 common/cmd_nand.c FIT image format OK
3413 - legacy image format:
3414 CONFIG_IMAGE_FORMAT_LEGACY
3415 enables the legacy image format support in U-Boot.
3418 enabled if CONFIG_FIT_SIGNATURE is not defined.
3420 CONFIG_DISABLE_IMAGE_LEGACY
3421 disable the legacy image format
3423 This define is introduced, as the legacy image format is
3424 enabled per default for backward compatibility.
3426 - FIT image support:
3428 Enable support for the FIT uImage format.
3430 CONFIG_FIT_BEST_MATCH
3431 When no configuration is explicitly selected, default to the
3432 one whose fdt's compatibility field best matches that of
3433 U-Boot itself. A match is considered "best" if it matches the
3434 most specific compatibility entry of U-Boot's fdt's root node.
3435 The order of entries in the configuration's fdt is ignored.
3437 CONFIG_FIT_SIGNATURE
3438 This option enables signature verification of FIT uImages,
3439 using a hash signed and verified using RSA. See
3440 doc/uImage.FIT/signature.txt for more details.
3442 WARNING: When relying on signed FIT images with required
3443 signature check the legacy image format is default
3444 disabled. If a board need legacy image format support
3445 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3447 CONFIG_FIT_DISABLE_SHA256
3448 Supporting SHA256 hashes has quite an impact on binary size.
3449 For constrained systems sha256 hash support can be disabled
3452 - Standalone program support:
3453 CONFIG_STANDALONE_LOAD_ADDR
3455 This option defines a board specific value for the
3456 address where standalone program gets loaded, thus
3457 overwriting the architecture dependent default
3460 - Frame Buffer Address:
3463 Define CONFIG_FB_ADDR if you want to use specific
3464 address for frame buffer. This is typically the case
3465 when using a graphics controller has separate video
3466 memory. U-Boot will then place the frame buffer at
3467 the given address instead of dynamically reserving it
3468 in system RAM by calling lcd_setmem(), which grabs
3469 the memory for the frame buffer depending on the
3470 configured panel size.
3472 Please see board_init_f function.
3474 - Automatic software updates via TFTP server
3476 CONFIG_UPDATE_TFTP_CNT_MAX
3477 CONFIG_UPDATE_TFTP_MSEC_MAX
3479 These options enable and control the auto-update feature;
3480 for a more detailed description refer to doc/README.update.
3482 - MTD Support (mtdparts command, UBI support)
3485 Adds the MTD device infrastructure from the Linux kernel.
3486 Needed for mtdparts command support.
3488 CONFIG_MTD_PARTITIONS
3490 Adds the MTD partitioning infrastructure from the Linux
3491 kernel. Needed for UBI support.
3493 CONFIG_MTD_NAND_VERIFY_WRITE
3494 verify if the written data is correct reread.
3499 Adds commands for interacting with MTD partitions formatted
3500 with the UBI flash translation layer
3502 Requires also defining CONFIG_RBTREE
3504 CONFIG_UBI_SILENCE_MSG
3506 Make the verbose messages from UBI stop printing. This leaves
3507 warnings and errors enabled.
3510 CONFIG_MTD_UBI_WL_THRESHOLD
3511 This parameter defines the maximum difference between the highest
3512 erase counter value and the lowest erase counter value of eraseblocks
3513 of UBI devices. When this threshold is exceeded, UBI starts performing
3514 wear leveling by means of moving data from eraseblock with low erase
3515 counter to eraseblocks with high erase counter.
3517 The default value should be OK for SLC NAND flashes, NOR flashes and
3518 other flashes which have eraseblock life-cycle 100000 or more.
3519 However, in case of MLC NAND flashes which typically have eraseblock
3520 life-cycle less than 10000, the threshold should be lessened (e.g.,
3521 to 128 or 256, although it does not have to be power of 2).
3525 CONFIG_MTD_UBI_BEB_LIMIT
3526 This option specifies the maximum bad physical eraseblocks UBI
3527 expects on the MTD device (per 1024 eraseblocks). If the
3528 underlying flash does not admit of bad eraseblocks (e.g. NOR
3529 flash), this value is ignored.
3531 NAND datasheets often specify the minimum and maximum NVM
3532 (Number of Valid Blocks) for the flashes' endurance lifetime.
3533 The maximum expected bad eraseblocks per 1024 eraseblocks
3534 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3535 which gives 20 for most NANDs (MaxNVB is basically the total
3536 count of eraseblocks on the chip).
3538 To put it differently, if this value is 20, UBI will try to
3539 reserve about 1.9% of physical eraseblocks for bad blocks
3540 handling. And that will be 1.9% of eraseblocks on the entire
3541 NAND chip, not just the MTD partition UBI attaches. This means
3542 that if you have, say, a NAND flash chip admits maximum 40 bad
3543 eraseblocks, and it is split on two MTD partitions of the same
3544 size, UBI will reserve 40 eraseblocks when attaching a
3549 CONFIG_MTD_UBI_FASTMAP
3550 Fastmap is a mechanism which allows attaching an UBI device
3551 in nearly constant time. Instead of scanning the whole MTD device it
3552 only has to locate a checkpoint (called fastmap) on the device.
3553 The on-flash fastmap contains all information needed to attach
3554 the device. Using fastmap makes only sense on large devices where
3555 attaching by scanning takes long. UBI will not automatically install
3556 a fastmap on old images, but you can set the UBI parameter
3557 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3558 that fastmap-enabled images are still usable with UBI implementations
3559 without fastmap support. On typical flash devices the whole fastmap
3560 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3562 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3563 Set this parameter to enable fastmap automatically on images
3570 Adds commands for interacting with UBI volumes formatted as
3571 UBIFS. UBIFS is read-only in u-boot.
3573 Requires UBI support as well as CONFIG_LZO
3575 CONFIG_UBIFS_SILENCE_MSG
3577 Make the verbose messages from UBIFS stop printing. This leaves
3578 warnings and errors enabled.
3582 Enable building of SPL globally.
3585 LDSCRIPT for linking the SPL binary.
3587 CONFIG_SPL_MAX_FOOTPRINT
3588 Maximum size in memory allocated to the SPL, BSS included.
3589 When defined, the linker checks that the actual memory
3590 used by SPL from _start to __bss_end does not exceed it.
3591 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3592 must not be both defined at the same time.
3595 Maximum size of the SPL image (text, data, rodata, and
3596 linker lists sections), BSS excluded.
3597 When defined, the linker checks that the actual size does
3600 CONFIG_SPL_TEXT_BASE
3601 TEXT_BASE for linking the SPL binary.
3603 CONFIG_SPL_RELOC_TEXT_BASE
3604 Address to relocate to. If unspecified, this is equal to
3605 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3607 CONFIG_SPL_BSS_START_ADDR
3608 Link address for the BSS within the SPL binary.
3610 CONFIG_SPL_BSS_MAX_SIZE
3611 Maximum size in memory allocated to the SPL BSS.
3612 When defined, the linker checks that the actual memory used
3613 by SPL from __bss_start to __bss_end does not exceed it.
3614 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3615 must not be both defined at the same time.
3618 Adress of the start of the stack SPL will use
3620 CONFIG_SPL_RELOC_STACK
3621 Adress of the start of the stack SPL will use after
3622 relocation. If unspecified, this is equal to
3625 CONFIG_SYS_SPL_MALLOC_START
3626 Starting address of the malloc pool used in SPL.
3628 CONFIG_SYS_SPL_MALLOC_SIZE
3629 The size of the malloc pool used in SPL.
3631 CONFIG_SPL_FRAMEWORK
3632 Enable the SPL framework under common/. This framework
3633 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3634 NAND loading of the Linux Kernel.
3637 Enable booting directly to an OS from SPL.
3638 See also: doc/README.falcon
3640 CONFIG_SPL_DISPLAY_PRINT
3641 For ARM, enable an optional function to print more information
3642 about the running system.
3644 CONFIG_SPL_INIT_MINIMAL
3645 Arch init code should be built for a very small image
3647 CONFIG_SPL_LIBCOMMON_SUPPORT
3648 Support for common/libcommon.o in SPL binary
3650 CONFIG_SPL_LIBDISK_SUPPORT
3651 Support for disk/libdisk.o in SPL binary
3653 CONFIG_SPL_I2C_SUPPORT
3654 Support for drivers/i2c/libi2c.o in SPL binary
3656 CONFIG_SPL_GPIO_SUPPORT
3657 Support for drivers/gpio/libgpio.o in SPL binary
3659 CONFIG_SPL_MMC_SUPPORT
3660 Support for drivers/mmc/libmmc.o in SPL binary
3662 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3663 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3664 Address and partition on the MMC to load U-Boot from
3665 when the MMC is being used in raw mode.
3667 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3668 Partition on the MMC to load U-Boot from when the MMC is being
3671 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3672 Sector to load kernel uImage from when MMC is being
3673 used in raw mode (for Falcon mode)
3675 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3676 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3677 Sector and number of sectors to load kernel argument
3678 parameters from when MMC is being used in raw mode
3681 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3682 Partition on the MMC to load U-Boot from when the MMC is being
3685 CONFIG_SPL_FAT_SUPPORT
3686 Support for fs/fat/libfat.o in SPL binary
3688 CONFIG_SPL_EXT_SUPPORT
3689 Support for EXT filesystem in SPL binary
3691 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3692 Filename to read to load U-Boot when reading from filesystem
3694 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3695 Filename to read to load kernel uImage when reading
3696 from filesystem (for Falcon mode)
3698 CONFIG_SPL_FS_LOAD_ARGS_NAME
3699 Filename to read to load kernel argument parameters
3700 when reading from filesystem (for Falcon mode)
3702 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3703 Set this for NAND SPL on PPC mpc83xx targets, so that
3704 start.S waits for the rest of the SPL to load before
3705 continuing (the hardware starts execution after just
3706 loading the first page rather than the full 4K).
3708 CONFIG_SPL_SKIP_RELOCATE
3709 Avoid SPL relocation
3711 CONFIG_SPL_NAND_BASE
3712 Include nand_base.c in the SPL. Requires
3713 CONFIG_SPL_NAND_DRIVERS.
3715 CONFIG_SPL_NAND_DRIVERS
3716 SPL uses normal NAND drivers, not minimal drivers.
3719 Include standard software ECC in the SPL
3721 CONFIG_SPL_NAND_SIMPLE
3722 Support for NAND boot using simple NAND drivers that
3723 expose the cmd_ctrl() interface.
3725 CONFIG_SPL_MTD_SUPPORT
3726 Support for the MTD subsystem within SPL. Useful for
3727 environment on NAND support within SPL.
3729 CONFIG_SPL_NAND_RAW_ONLY
3730 Support to boot only raw u-boot.bin images. Use this only
3731 if you need to save space.
3733 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3734 Set for the SPL on PPC mpc8xxx targets, support for
3735 drivers/ddr/fsl/libddr.o in SPL binary.
3737 CONFIG_SPL_COMMON_INIT_DDR
3738 Set for common ddr init with serial presence detect in
3741 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3742 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3743 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3744 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3745 CONFIG_SYS_NAND_ECCBYTES
3746 Defines the size and behavior of the NAND that SPL uses
3749 CONFIG_SPL_NAND_BOOT
3750 Add support NAND boot
3752 CONFIG_SYS_NAND_U_BOOT_OFFS
3753 Location in NAND to read U-Boot from
3755 CONFIG_SYS_NAND_U_BOOT_DST
3756 Location in memory to load U-Boot to
3758 CONFIG_SYS_NAND_U_BOOT_SIZE
3759 Size of image to load
3761 CONFIG_SYS_NAND_U_BOOT_START
3762 Entry point in loaded image to jump to
3764 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3765 Define this if you need to first read the OOB and then the
3766 data. This is used for example on davinci plattforms.
3768 CONFIG_SPL_OMAP3_ID_NAND
3769 Support for an OMAP3-specific set of functions to return the
3770 ID and MFR of the first attached NAND chip, if present.
3772 CONFIG_SPL_SERIAL_SUPPORT
3773 Support for drivers/serial/libserial.o in SPL binary
3775 CONFIG_SPL_SPI_FLASH_SUPPORT
3776 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3778 CONFIG_SPL_SPI_SUPPORT
3779 Support for drivers/spi/libspi.o in SPL binary
3781 CONFIG_SPL_RAM_DEVICE
3782 Support for running image already present in ram, in SPL binary
3784 CONFIG_SPL_LIBGENERIC_SUPPORT
3785 Support for lib/libgeneric.o in SPL binary
3787 CONFIG_SPL_ENV_SUPPORT
3788 Support for the environment operating in SPL binary
3790 CONFIG_SPL_NET_SUPPORT
3791 Support for the net/libnet.o in SPL binary.
3792 It conflicts with SPL env from storage medium specified by
3793 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3796 Image offset to which the SPL should be padded before appending
3797 the SPL payload. By default, this is defined as
3798 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3799 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3800 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3803 Final target image containing SPL and payload. Some SPLs
3804 use an arch-specific makefile fragment instead, for
3805 example if more than one image needs to be produced.
3807 CONFIG_FIT_SPL_PRINT
3808 Printing information about a FIT image adds quite a bit of
3809 code to SPL. So this is normally disabled in SPL. Use this
3810 option to re-enable it. This will affect the output of the
3811 bootm command when booting a FIT image.
3815 Enable building of TPL globally.
3818 Image offset to which the TPL should be padded before appending
3819 the TPL payload. By default, this is defined as
3820 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3821 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3822 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3827 [so far only for SMDK2400 boards]
3829 - Modem support enable:
3830 CONFIG_MODEM_SUPPORT
3832 - RTS/CTS Flow control enable:
3835 - Modem debug support:
3836 CONFIG_MODEM_SUPPORT_DEBUG
3838 Enables debugging stuff (char screen[1024], dbg())
3839 for modem support. Useful only with BDI2000.
3841 - Interrupt support (PPC):
3843 There are common interrupt_init() and timer_interrupt()
3844 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3845 for CPU specific initialization. interrupt_init_cpu()
3846 should set decrementer_count to appropriate value. If
3847 CPU resets decrementer automatically after interrupt
3848 (ppc4xx) it should set decrementer_count to zero.
3849 timer_interrupt() calls timer_interrupt_cpu() for CPU
3850 specific handling. If board has watchdog / status_led
3851 / other_activity_monitor it works automatically from
3852 general timer_interrupt().
3856 In the target system modem support is enabled when a
3857 specific key (key combination) is pressed during
3858 power-on. Otherwise U-Boot will boot normally
3859 (autoboot). The key_pressed() function is called from
3860 board_init(). Currently key_pressed() is a dummy
3861 function, returning 1 and thus enabling modem
3864 If there are no modem init strings in the
3865 environment, U-Boot proceed to autoboot; the
3866 previous output (banner, info printfs) will be
3869 See also: doc/README.Modem
3871 Board initialization settings:
3872 ------------------------------
3874 During Initialization u-boot calls a number of board specific functions
3875 to allow the preparation of board specific prerequisites, e.g. pin setup
3876 before drivers are initialized. To enable these callbacks the
3877 following configuration macros have to be defined. Currently this is
3878 architecture specific, so please check arch/your_architecture/lib/board.c
3879 typically in board_init_f() and board_init_r().
3881 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3882 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3883 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3884 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3886 Configuration Settings:
3887 -----------------------
3889 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3890 Optionally it can be defined to support 64-bit memory commands.
3892 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3893 undefine this when you're short of memory.
3895 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3896 width of the commands listed in the 'help' command output.
3898 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3899 prompt for user input.
3901 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3903 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3905 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3907 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3908 the application (usually a Linux kernel) when it is
3911 - CONFIG_SYS_BAUDRATE_TABLE:
3912 List of legal baudrate settings for this board.
3914 - CONFIG_SYS_CONSOLE_INFO_QUIET
3915 Suppress display of console information at boot.
3917 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3918 If the board specific function
3919 extern int overwrite_console (void);
3920 returns 1, the stdin, stderr and stdout are switched to the
3921 serial port, else the settings in the environment are used.
3923 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3924 Enable the call to overwrite_console().
3926 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3927 Enable overwrite of previous console environment settings.
3929 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3930 Begin and End addresses of the area used by the
3933 - CONFIG_SYS_ALT_MEMTEST:
3934 Enable an alternate, more extensive memory test.
3936 - CONFIG_SYS_MEMTEST_SCRATCH:
3937 Scratch address used by the alternate memory test
3938 You only need to set this if address zero isn't writeable
3940 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3941 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3942 this specified memory area will get subtracted from the top
3943 (end) of RAM and won't get "touched" at all by U-Boot. By
3944 fixing up gd->ram_size the Linux kernel should gets passed
3945 the now "corrected" memory size and won't touch it either.
3946 This should work for arch/ppc and arch/powerpc. Only Linux
3947 board ports in arch/powerpc with bootwrapper support that
3948 recalculate the memory size from the SDRAM controller setup
3949 will have to get fixed in Linux additionally.
3951 This option can be used as a workaround for the 440EPx/GRx
3952 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3955 WARNING: Please make sure that this value is a multiple of
3956 the Linux page size (normally 4k). If this is not the case,
3957 then the end address of the Linux memory will be located at a
3958 non page size aligned address and this could cause major
3961 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3962 Enable temporary baudrate change while serial download
3964 - CONFIG_SYS_SDRAM_BASE:
3965 Physical start address of SDRAM. _Must_ be 0 here.
3967 - CONFIG_SYS_MBIO_BASE:
3968 Physical start address of Motherboard I/O (if using a
3971 - CONFIG_SYS_FLASH_BASE:
3972 Physical start address of Flash memory.
3974 - CONFIG_SYS_MONITOR_BASE:
3975 Physical start address of boot monitor code (set by
3976 make config files to be same as the text base address
3977 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3978 CONFIG_SYS_FLASH_BASE when booting from flash.
3980 - CONFIG_SYS_MONITOR_LEN:
3981 Size of memory reserved for monitor code, used to
3982 determine _at_compile_time_ (!) if the environment is
3983 embedded within the U-Boot image, or in a separate
3986 - CONFIG_SYS_MALLOC_LEN:
3987 Size of DRAM reserved for malloc() use.
3989 - CONFIG_SYS_MALLOC_F_LEN
3990 Size of the malloc() pool for use before relocation. If
3991 this is defined, then a very simple malloc() implementation
3992 will become available before relocation. The address is just
3993 below the global data, and the stack is moved down to make
3996 This feature allocates regions with increasing addresses
3997 within the region. calloc() is supported, but realloc()
3998 is not available. free() is supported but does nothing.
3999 The memory will be freed (or in fact just forgotton) when
4000 U-Boot relocates itself.
4002 Pre-relocation malloc() is only supported on ARM and sandbox
4003 at present but is fairly easy to enable for other archs.
4005 - CONFIG_SYS_MALLOC_SIMPLE
4006 Provides a simple and small malloc() and calloc() for those
4007 boards which do not use the full malloc in SPL (which is
4008 enabled with CONFIG_SYS_SPL_MALLOC_START).
4010 - CONFIG_SYS_BOOTM_LEN:
4011 Normally compressed uImages are limited to an
4012 uncompressed size of 8 MBytes. If this is not enough,
4013 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4014 to adjust this setting to your needs.
4016 - CONFIG_SYS_BOOTMAPSZ:
4017 Maximum size of memory mapped by the startup code of
4018 the Linux kernel; all data that must be processed by
4019 the Linux kernel (bd_info, boot arguments, FDT blob if
4020 used) must be put below this limit, unless "bootm_low"
4021 environment variable is defined and non-zero. In such case
4022 all data for the Linux kernel must be between "bootm_low"
4023 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4024 variable "bootm_mapsize" will override the value of
4025 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4026 then the value in "bootm_size" will be used instead.
4028 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4029 Enable initrd_high functionality. If defined then the
4030 initrd_high feature is enabled and the bootm ramdisk subcommand
4033 - CONFIG_SYS_BOOT_GET_CMDLINE:
4034 Enables allocating and saving kernel cmdline in space between
4035 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4037 - CONFIG_SYS_BOOT_GET_KBD:
4038 Enables allocating and saving a kernel copy of the bd_info in
4039 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4041 - CONFIG_SYS_MAX_FLASH_BANKS:
4042 Max number of Flash memory banks
4044 - CONFIG_SYS_MAX_FLASH_SECT:
4045 Max number of sectors on a Flash chip
4047 - CONFIG_SYS_FLASH_ERASE_TOUT:
4048 Timeout for Flash erase operations (in ms)
4050 - CONFIG_SYS_FLASH_WRITE_TOUT:
4051 Timeout for Flash write operations (in ms)
4053 - CONFIG_SYS_FLASH_LOCK_TOUT
4054 Timeout for Flash set sector lock bit operation (in ms)
4056 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4057 Timeout for Flash clear lock bits operation (in ms)
4059 - CONFIG_SYS_FLASH_PROTECTION
4060 If defined, hardware flash sectors protection is used
4061 instead of U-Boot software protection.
4063 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4065 Enable TFTP transfers directly to flash memory;
4066 without this option such a download has to be
4067 performed in two steps: (1) download to RAM, and (2)
4068 copy from RAM to flash.
4070 The two-step approach is usually more reliable, since
4071 you can check if the download worked before you erase
4072 the flash, but in some situations (when system RAM is
4073 too limited to allow for a temporary copy of the
4074 downloaded image) this option may be very useful.
4076 - CONFIG_SYS_FLASH_CFI:
4077 Define if the flash driver uses extra elements in the
4078 common flash structure for storing flash geometry.
4080 - CONFIG_FLASH_CFI_DRIVER
4081 This option also enables the building of the cfi_flash driver
4082 in the drivers directory
4084 - CONFIG_FLASH_CFI_MTD
4085 This option enables the building of the cfi_mtd driver
4086 in the drivers directory. The driver exports CFI flash
4089 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4090 Use buffered writes to flash.
4092 - CONFIG_FLASH_SPANSION_S29WS_N
4093 s29ws-n MirrorBit flash has non-standard addresses for buffered
4096 - CONFIG_SYS_FLASH_QUIET_TEST
4097 If this option is defined, the common CFI flash doesn't
4098 print it's warning upon not recognized FLASH banks. This
4099 is useful, if some of the configured banks are only
4100 optionally available.
4102 - CONFIG_FLASH_SHOW_PROGRESS
4103 If defined (must be an integer), print out countdown
4104 digits and dots. Recommended value: 45 (9..1) for 80
4105 column displays, 15 (3..1) for 40 column displays.
4107 - CONFIG_FLASH_VERIFY
4108 If defined, the content of the flash (destination) is compared
4109 against the source after the write operation. An error message
4110 will be printed when the contents are not identical.
4111 Please note that this option is useless in nearly all cases,
4112 since such flash programming errors usually are detected earlier
4113 while unprotecting/erasing/programming. Please only enable
4114 this option if you really know what you are doing.
4116 - CONFIG_SYS_RX_ETH_BUFFER:
4117 Defines the number of Ethernet receive buffers. On some
4118 Ethernet controllers it is recommended to set this value
4119 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4120 buffers can be full shortly after enabling the interface
4121 on high Ethernet traffic.
4122 Defaults to 4 if not defined.
4124 - CONFIG_ENV_MAX_ENTRIES
4126 Maximum number of entries in the hash table that is used
4127 internally to store the environment settings. The default
4128 setting is supposed to be generous and should work in most
4129 cases. This setting can be used to tune behaviour; see
4130 lib/hashtable.c for details.
4132 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4133 - CONFIG_ENV_FLAGS_LIST_STATIC
4134 Enable validation of the values given to environment variables when
4135 calling env set. Variables can be restricted to only decimal,
4136 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4137 the variables can also be restricted to IP address or MAC address.
4139 The format of the list is:
4140 type_attribute = [s|d|x|b|i|m]
4141 access_atribute = [a|r|o|c]
4142 attributes = type_attribute[access_atribute]
4143 entry = variable_name[:attributes]
4146 The type attributes are:
4147 s - String (default)
4150 b - Boolean ([1yYtT|0nNfF])
4154 The access attributes are:
4160 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4161 Define this to a list (string) to define the ".flags"
4162 envirnoment variable in the default or embedded environment.
4164 - CONFIG_ENV_FLAGS_LIST_STATIC
4165 Define this to a list (string) to define validation that
4166 should be done if an entry is not found in the ".flags"
4167 environment variable. To override a setting in the static
4168 list, simply add an entry for the same variable name to the
4171 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4172 If defined, don't allow the -f switch to env set override variable
4175 - CONFIG_SYS_GENERIC_BOARD
4176 This selects the architecture-generic board system instead of the
4177 architecture-specific board files. It is intended to move boards
4178 to this new framework over time. Defining this will disable the
4179 arch/foo/lib/board.c file and use common/board_f.c and
4180 common/board_r.c instead. To use this option your architecture
4181 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4182 its config.mk file). If you find problems enabling this option on
4183 your board please report the problem and send patches!
4185 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4186 This is set by OMAP boards for the max time that reset should
4187 be asserted. See doc/README.omap-reset-time for details on how
4188 the value can be calulated on a given board.
4191 If stdint.h is available with your toolchain you can define this
4192 option to enable it. You can provide option 'USE_STDINT=1' when
4193 building U-Boot to enable this.
4195 The following definitions that deal with the placement and management
4196 of environment data (variable area); in general, we support the
4197 following configurations:
4199 - CONFIG_BUILD_ENVCRC:
4201 Builds up envcrc with the target environment so that external utils
4202 may easily extract it and embed it in final U-Boot images.
4204 - CONFIG_ENV_IS_IN_FLASH:
4206 Define this if the environment is in flash memory.
4208 a) The environment occupies one whole flash sector, which is
4209 "embedded" in the text segment with the U-Boot code. This
4210 happens usually with "bottom boot sector" or "top boot
4211 sector" type flash chips, which have several smaller
4212 sectors at the start or the end. For instance, such a
4213 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4214 such a case you would place the environment in one of the
4215 4 kB sectors - with U-Boot code before and after it. With
4216 "top boot sector" type flash chips, you would put the
4217 environment in one of the last sectors, leaving a gap
4218 between U-Boot and the environment.
4220 - CONFIG_ENV_OFFSET:
4222 Offset of environment data (variable area) to the
4223 beginning of flash memory; for instance, with bottom boot
4224 type flash chips the second sector can be used: the offset
4225 for this sector is given here.
4227 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4231 This is just another way to specify the start address of
4232 the flash sector containing the environment (instead of
4235 - CONFIG_ENV_SECT_SIZE:
4237 Size of the sector containing the environment.
4240 b) Sometimes flash chips have few, equal sized, BIG sectors.
4241 In such a case you don't want to spend a whole sector for
4246 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4247 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4248 of this flash sector for the environment. This saves
4249 memory for the RAM copy of the environment.
4251 It may also save flash memory if you decide to use this
4252 when your environment is "embedded" within U-Boot code,
4253 since then the remainder of the flash sector could be used
4254 for U-Boot code. It should be pointed out that this is
4255 STRONGLY DISCOURAGED from a robustness point of view:
4256 updating the environment in flash makes it always
4257 necessary to erase the WHOLE sector. If something goes
4258 wrong before the contents has been restored from a copy in
4259 RAM, your target system will be dead.
4261 - CONFIG_ENV_ADDR_REDUND
4262 CONFIG_ENV_SIZE_REDUND
4264 These settings describe a second storage area used to hold
4265 a redundant copy of the environment data, so that there is
4266 a valid backup copy in case there is a power failure during
4267 a "saveenv" operation.
4269 BE CAREFUL! Any changes to the flash layout, and some changes to the
4270 source code will make it necessary to adapt <board>/u-boot.lds*
4274 - CONFIG_ENV_IS_IN_NVRAM:
4276 Define this if you have some non-volatile memory device
4277 (NVRAM, battery buffered SRAM) which you want to use for the
4283 These two #defines are used to determine the memory area you
4284 want to use for environment. It is assumed that this memory
4285 can just be read and written to, without any special
4288 BE CAREFUL! The first access to the environment happens quite early
4289 in U-Boot initalization (when we try to get the setting of for the
4290 console baudrate). You *MUST* have mapped your NVRAM area then, or
4293 Please note that even with NVRAM we still use a copy of the
4294 environment in RAM: we could work on NVRAM directly, but we want to
4295 keep settings there always unmodified except somebody uses "saveenv"
4296 to save the current settings.
4299 - CONFIG_ENV_IS_IN_EEPROM:
4301 Use this if you have an EEPROM or similar serial access
4302 device and a driver for it.
4304 - CONFIG_ENV_OFFSET:
4307 These two #defines specify the offset and size of the
4308 environment area within the total memory of your EEPROM.
4310 - CONFIG_SYS_I2C_EEPROM_ADDR:
4311 If defined, specified the chip address of the EEPROM device.
4312 The default address is zero.
4314 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4315 If defined, the number of bits used to address bytes in a
4316 single page in the EEPROM device. A 64 byte page, for example
4317 would require six bits.
4319 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4320 If defined, the number of milliseconds to delay between
4321 page writes. The default is zero milliseconds.
4323 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4324 The length in bytes of the EEPROM memory array address. Note
4325 that this is NOT the chip address length!
4327 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4328 EEPROM chips that implement "address overflow" are ones
4329 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4330 address and the extra bits end up in the "chip address" bit
4331 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4334 Note that we consider the length of the address field to
4335 still be one byte because the extra address bits are hidden
4336 in the chip address.
4338 - CONFIG_SYS_EEPROM_SIZE:
4339 The size in bytes of the EEPROM device.
4341 - CONFIG_ENV_EEPROM_IS_ON_I2C
4342 define this, if you have I2C and SPI activated, and your
4343 EEPROM, which holds the environment, is on the I2C bus.
4345 - CONFIG_I2C_ENV_EEPROM_BUS
4346 if you have an Environment on an EEPROM reached over
4347 I2C muxes, you can define here, how to reach this
4348 EEPROM. For example:
4350 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4352 EEPROM which holds the environment, is reached over
4353 a pca9547 i2c mux with address 0x70, channel 3.
4355 - CONFIG_ENV_IS_IN_DATAFLASH:
4357 Define this if you have a DataFlash memory device which you
4358 want to use for the environment.
4360 - CONFIG_ENV_OFFSET:
4364 These three #defines specify the offset and size of the
4365 environment area within the total memory of your DataFlash placed
4366 at the specified address.
4368 - CONFIG_ENV_IS_IN_SPI_FLASH:
4370 Define this if you have a SPI Flash memory device which you
4371 want to use for the environment.
4373 - CONFIG_ENV_OFFSET:
4376 These two #defines specify the offset and size of the
4377 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4378 aligned to an erase sector boundary.
4380 - CONFIG_ENV_SECT_SIZE:
4382 Define the SPI flash's sector size.
4384 - CONFIG_ENV_OFFSET_REDUND (optional):
4386 This setting describes a second storage area of CONFIG_ENV_SIZE
4387 size used to hold a redundant copy of the environment data, so
4388 that there is a valid backup copy in case there is a power failure
4389 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4390 aligned to an erase sector boundary.
4392 - CONFIG_ENV_SPI_BUS (optional):
4393 - CONFIG_ENV_SPI_CS (optional):
4395 Define the SPI bus and chip select. If not defined they will be 0.
4397 - CONFIG_ENV_SPI_MAX_HZ (optional):
4399 Define the SPI max work clock. If not defined then use 1MHz.
4401 - CONFIG_ENV_SPI_MODE (optional):
4403 Define the SPI work mode. If not defined then use SPI_MODE_3.
4405 - CONFIG_ENV_IS_IN_REMOTE:
4407 Define this if you have a remote memory space which you
4408 want to use for the local device's environment.
4413 These two #defines specify the address and size of the
4414 environment area within the remote memory space. The
4415 local device can get the environment from remote memory
4416 space by SRIO or PCIE links.
4418 BE CAREFUL! For some special cases, the local device can not use
4419 "saveenv" command. For example, the local device will get the
4420 environment stored in a remote NOR flash by SRIO or PCIE link,
4421 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4423 - CONFIG_ENV_IS_IN_NAND:
4425 Define this if you have a NAND device which you want to use
4426 for the environment.
4428 - CONFIG_ENV_OFFSET:
4431 These two #defines specify the offset and size of the environment
4432 area within the first NAND device. CONFIG_ENV_OFFSET must be
4433 aligned to an erase block boundary.
4435 - CONFIG_ENV_OFFSET_REDUND (optional):
4437 This setting describes a second storage area of CONFIG_ENV_SIZE
4438 size used to hold a redundant copy of the environment data, so
4439 that there is a valid backup copy in case there is a power failure
4440 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4441 aligned to an erase block boundary.
4443 - CONFIG_ENV_RANGE (optional):
4445 Specifies the length of the region in which the environment
4446 can be written. This should be a multiple of the NAND device's
4447 block size. Specifying a range with more erase blocks than
4448 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4449 the range to be avoided.
4451 - CONFIG_ENV_OFFSET_OOB (optional):
4453 Enables support for dynamically retrieving the offset of the
4454 environment from block zero's out-of-band data. The
4455 "nand env.oob" command can be used to record this offset.
4456 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4457 using CONFIG_ENV_OFFSET_OOB.
4459 - CONFIG_NAND_ENV_DST
4461 Defines address in RAM to which the nand_spl code should copy the
4462 environment. If redundant environment is used, it will be copied to
4463 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4465 - CONFIG_ENV_IS_IN_UBI:
4467 Define this if you have an UBI volume that you want to use for the
4468 environment. This has the benefit of wear-leveling the environment
4469 accesses, which is important on NAND.
4471 - CONFIG_ENV_UBI_PART:
4473 Define this to a string that is the mtd partition containing the UBI.
4475 - CONFIG_ENV_UBI_VOLUME:
4477 Define this to the name of the volume that you want to store the
4480 - CONFIG_ENV_UBI_VOLUME_REDUND:
4482 Define this to the name of another volume to store a second copy of
4483 the environment in. This will enable redundant environments in UBI.
4484 It is assumed that both volumes are in the same MTD partition.
4486 - CONFIG_UBI_SILENCE_MSG
4487 - CONFIG_UBIFS_SILENCE_MSG
4489 You will probably want to define these to avoid a really noisy system
4490 when storing the env in UBI.
4492 - CONFIG_ENV_IS_IN_FAT:
4493 Define this if you want to use the FAT file system for the environment.
4495 - FAT_ENV_INTERFACE:
4497 Define this to a string that is the name of the block device.
4499 - FAT_ENV_DEV_AND_PART:
4501 Define this to a string to specify the partition of the device. It can
4504 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4505 - "D:P": device D partition P. Error occurs if device D has no
4508 - "D" or "D:": device D partition 1 if device D has partition
4509 table, or the whole device D if has no partition
4511 - "D:auto": first partition in device D with bootable flag set.
4512 If none, first valid paratition in device D. If no
4513 partition table then means device D.
4517 It's a string of the FAT file name. This file use to store the
4521 This should be defined. Otherwise it cannot save the envrionment file.
4523 - CONFIG_ENV_IS_IN_MMC:
4525 Define this if you have an MMC device which you want to use for the
4528 - CONFIG_SYS_MMC_ENV_DEV:
4530 Specifies which MMC device the environment is stored in.
4532 - CONFIG_SYS_MMC_ENV_PART (optional):
4534 Specifies which MMC partition the environment is stored in. If not
4535 set, defaults to partition 0, the user area. Common values might be
4536 1 (first MMC boot partition), 2 (second MMC boot partition).
4538 - CONFIG_ENV_OFFSET:
4541 These two #defines specify the offset and size of the environment
4542 area within the specified MMC device.
4544 If offset is positive (the usual case), it is treated as relative to
4545 the start of the MMC partition. If offset is negative, it is treated
4546 as relative to the end of the MMC partition. This can be useful if
4547 your board may be fitted with different MMC devices, which have
4548 different sizes for the MMC partitions, and you always want the
4549 environment placed at the very end of the partition, to leave the
4550 maximum possible space before it, to store other data.
4552 These two values are in units of bytes, but must be aligned to an
4553 MMC sector boundary.
4555 - CONFIG_ENV_OFFSET_REDUND (optional):
4557 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4558 hold a redundant copy of the environment data. This provides a
4559 valid backup copy in case the other copy is corrupted, e.g. due
4560 to a power failure during a "saveenv" operation.
4562 This value may also be positive or negative; this is handled in the
4563 same way as CONFIG_ENV_OFFSET.
4565 This value is also in units of bytes, but must also be aligned to
4566 an MMC sector boundary.
4568 - CONFIG_ENV_SIZE_REDUND (optional):
4570 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4571 set. If this value is set, it must be set to the same value as
4574 - CONFIG_SYS_SPI_INIT_OFFSET
4576 Defines offset to the initial SPI buffer area in DPRAM. The
4577 area is used at an early stage (ROM part) if the environment
4578 is configured to reside in the SPI EEPROM: We need a 520 byte
4579 scratch DPRAM area. It is used between the two initialization
4580 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4581 to be a good choice since it makes it far enough from the
4582 start of the data area as well as from the stack pointer.
4584 Please note that the environment is read-only until the monitor
4585 has been relocated to RAM and a RAM copy of the environment has been
4586 created; also, when using EEPROM you will have to use getenv_f()
4587 until then to read environment variables.
4589 The environment is protected by a CRC32 checksum. Before the monitor
4590 is relocated into RAM, as a result of a bad CRC you will be working
4591 with the compiled-in default environment - *silently*!!! [This is
4592 necessary, because the first environment variable we need is the
4593 "baudrate" setting for the console - if we have a bad CRC, we don't
4594 have any device yet where we could complain.]
4596 Note: once the monitor has been relocated, then it will complain if
4597 the default environment is used; a new CRC is computed as soon as you
4598 use the "saveenv" command to store a valid environment.
4600 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4601 Echo the inverted Ethernet link state to the fault LED.
4603 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4604 also needs to be defined.
4606 - CONFIG_SYS_FAULT_MII_ADDR:
4607 MII address of the PHY to check for the Ethernet link state.
4609 - CONFIG_NS16550_MIN_FUNCTIONS:
4610 Define this if you desire to only have use of the NS16550_init
4611 and NS16550_putc functions for the serial driver located at
4612 drivers/serial/ns16550.c. This option is useful for saving
4613 space for already greatly restricted images, including but not
4614 limited to NAND_SPL configurations.
4616 - CONFIG_DISPLAY_BOARDINFO
4617 Display information about the board that U-Boot is running on
4618 when U-Boot starts up. The board function checkboard() is called
4621 - CONFIG_DISPLAY_BOARDINFO_LATE
4622 Similar to the previous option, but display this information
4623 later, once stdio is running and output goes to the LCD, if
4626 - CONFIG_BOARD_SIZE_LIMIT:
4627 Maximum size of the U-Boot image. When defined, the
4628 build system checks that the actual size does not
4631 Low Level (hardware related) configuration options:
4632 ---------------------------------------------------
4634 - CONFIG_SYS_CACHELINE_SIZE:
4635 Cache Line Size of the CPU.
4637 - CONFIG_SYS_DEFAULT_IMMR:
4638 Default address of the IMMR after system reset.
4640 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4641 and RPXsuper) to be able to adjust the position of
4642 the IMMR register after a reset.
4644 - CONFIG_SYS_CCSRBAR_DEFAULT:
4645 Default (power-on reset) physical address of CCSR on Freescale
4648 - CONFIG_SYS_CCSRBAR:
4649 Virtual address of CCSR. On a 32-bit build, this is typically
4650 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4652 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4653 for cross-platform code that uses that macro instead.
4655 - CONFIG_SYS_CCSRBAR_PHYS:
4656 Physical address of CCSR. CCSR can be relocated to a new
4657 physical address, if desired. In this case, this macro should
4658 be set to that address. Otherwise, it should be set to the
4659 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4660 is typically relocated on 36-bit builds. It is recommended
4661 that this macro be defined via the _HIGH and _LOW macros:
4663 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4664 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4666 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4667 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4668 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4669 used in assembly code, so it must not contain typecasts or
4670 integer size suffixes (e.g. "ULL").
4672 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4673 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4674 used in assembly code, so it must not contain typecasts or
4675 integer size suffixes (e.g. "ULL").
4677 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4678 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4679 forced to a value that ensures that CCSR is not relocated.
4681 - Floppy Disk Support:
4682 CONFIG_SYS_FDC_DRIVE_NUMBER
4684 the default drive number (default value 0)
4686 CONFIG_SYS_ISA_IO_STRIDE
4688 defines the spacing between FDC chipset registers
4691 CONFIG_SYS_ISA_IO_OFFSET
4693 defines the offset of register from address. It
4694 depends on which part of the data bus is connected to
4695 the FDC chipset. (default value 0)
4697 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4698 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4701 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4702 fdc_hw_init() is called at the beginning of the FDC
4703 setup. fdc_hw_init() must be provided by the board
4704 source code. It is used to make hardware dependant
4708 Most IDE controllers were designed to be connected with PCI
4709 interface. Only few of them were designed for AHB interface.
4710 When software is doing ATA command and data transfer to
4711 IDE devices through IDE-AHB controller, some additional
4712 registers accessing to these kind of IDE-AHB controller
4715 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4716 DO NOT CHANGE unless you know exactly what you're
4717 doing! (11-4) [MPC8xx/82xx systems only]
4719 - CONFIG_SYS_INIT_RAM_ADDR:
4721 Start address of memory area that can be used for
4722 initial data and stack; please note that this must be
4723 writable memory that is working WITHOUT special
4724 initialization, i. e. you CANNOT use normal RAM which
4725 will become available only after programming the
4726 memory controller and running certain initialization
4729 U-Boot uses the following memory types:
4730 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4731 - MPC824X: data cache
4732 - PPC4xx: data cache
4734 - CONFIG_SYS_GBL_DATA_OFFSET:
4736 Offset of the initial data structure in the memory
4737 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4738 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4739 data is located at the end of the available space
4740 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4741 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4742 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4743 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4746 On the MPC824X (or other systems that use the data
4747 cache for initial memory) the address chosen for
4748 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4749 point to an otherwise UNUSED address space between
4750 the top of RAM and the start of the PCI space.
4752 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4754 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4756 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4758 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4760 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4762 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4764 - CONFIG_SYS_OR_TIMING_SDRAM:
4767 - CONFIG_SYS_MAMR_PTA:
4768 periodic timer for refresh
4770 - CONFIG_SYS_DER: Debug Event Register (37-47)
4772 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4773 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4774 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4775 CONFIG_SYS_BR1_PRELIM:
4776 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4778 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4779 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4780 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4781 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4783 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4784 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4785 Machine Mode Register and Memory Periodic Timer
4786 Prescaler definitions (SDRAM timing)
4788 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4789 enable I2C microcode relocation patch (MPC8xx);
4790 define relocation offset in DPRAM [DSP2]
4792 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4793 enable SMC microcode relocation patch (MPC8xx);
4794 define relocation offset in DPRAM [SMC1]
4796 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4797 enable SPI microcode relocation patch (MPC8xx);
4798 define relocation offset in DPRAM [SCC4]
4800 - CONFIG_SYS_USE_OSCCLK:
4801 Use OSCM clock mode on MBX8xx board. Be careful,
4802 wrong setting might damage your board. Read
4803 doc/README.MBX before setting this variable!
4805 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4806 Offset of the bootmode word in DPRAM used by post
4807 (Power On Self Tests). This definition overrides
4808 #define'd default value in commproc.h resp.
4811 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4812 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4813 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4814 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4815 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4816 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4817 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4818 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4819 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4821 - CONFIG_PCI_DISABLE_PCIE:
4822 Disable PCI-Express on systems where it is supported but not
4825 - CONFIG_PCI_ENUM_ONLY
4826 Only scan through and get the devices on the busses.
4827 Don't do any setup work, presumably because someone or
4828 something has already done it, and we don't need to do it
4829 a second time. Useful for platforms that are pre-booted
4830 by coreboot or similar.
4832 - CONFIG_PCI_INDIRECT_BRIDGE:
4833 Enable support for indirect PCI bridges.
4836 Chip has SRIO or not
4839 Board has SRIO 1 port available
4842 Board has SRIO 2 port available
4844 - CONFIG_SRIO_PCIE_BOOT_MASTER
4845 Board can support master function for Boot from SRIO and PCIE
4847 - CONFIG_SYS_SRIOn_MEM_VIRT:
4848 Virtual Address of SRIO port 'n' memory region
4850 - CONFIG_SYS_SRIOn_MEM_PHYS:
4851 Physical Address of SRIO port 'n' memory region
4853 - CONFIG_SYS_SRIOn_MEM_SIZE:
4854 Size of SRIO port 'n' memory region
4856 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4857 Defined to tell the NAND controller that the NAND chip is using
4859 Not all NAND drivers use this symbol.
4860 Example of drivers that use it:
4861 - drivers/mtd/nand/ndfc.c
4862 - drivers/mtd/nand/mxc_nand.c
4864 - CONFIG_SYS_NDFC_EBC0_CFG
4865 Sets the EBC0_CFG register for the NDFC. If not defined
4866 a default value will be used.
4869 Get DDR timing information from an I2C EEPROM. Common
4870 with pluggable memory modules such as SODIMMs
4873 I2C address of the SPD EEPROM
4875 - CONFIG_SYS_SPD_BUS_NUM
4876 If SPD EEPROM is on an I2C bus other than the first
4877 one, specify here. Note that the value must resolve
4878 to something your driver can deal with.
4880 - CONFIG_SYS_DDR_RAW_TIMING
4881 Get DDR timing information from other than SPD. Common with
4882 soldered DDR chips onboard without SPD. DDR raw timing
4883 parameters are extracted from datasheet and hard-coded into
4884 header files or board specific files.
4886 - CONFIG_FSL_DDR_INTERACTIVE
4887 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4889 - CONFIG_SYS_83XX_DDR_USES_CS0
4890 Only for 83xx systems. If specified, then DDR should
4891 be configured using CS0 and CS1 instead of CS2 and CS3.
4893 - CONFIG_ETHER_ON_FEC[12]
4894 Define to enable FEC[12] on a 8xx series processor.
4896 - CONFIG_FEC[12]_PHY
4897 Define to the hardcoded PHY address which corresponds
4898 to the given FEC; i. e.
4899 #define CONFIG_FEC1_PHY 4
4900 means that the PHY with address 4 is connected to FEC1
4902 When set to -1, means to probe for first available.
4904 - CONFIG_FEC[12]_PHY_NORXERR
4905 The PHY does not have a RXERR line (RMII only).
4906 (so program the FEC to ignore it).
4909 Enable RMII mode for all FECs.
4910 Note that this is a global option, we can't
4911 have one FEC in standard MII mode and another in RMII mode.
4913 - CONFIG_CRC32_VERIFY
4914 Add a verify option to the crc32 command.
4917 => crc32 -v <address> <count> <crc32>
4919 Where address/count indicate a memory area
4920 and crc32 is the correct crc32 which the
4924 Add the "loopw" memory command. This only takes effect if
4925 the memory commands are activated globally (CONFIG_CMD_MEM).
4928 Add the "mdc" and "mwc" memory commands. These are cyclic
4933 This command will print 4 bytes (10,11,12,13) each 500 ms.
4935 => mwc.l 100 12345678 10
4936 This command will write 12345678 to address 100 all 10 ms.
4938 This only takes effect if the memory commands are activated
4939 globally (CONFIG_CMD_MEM).
4941 - CONFIG_SKIP_LOWLEVEL_INIT
4942 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4943 low level initializations (like setting up the memory
4944 controller) are omitted and/or U-Boot does not
4945 relocate itself into RAM.
4947 Normally this variable MUST NOT be defined. The only
4948 exception is when U-Boot is loaded (to RAM) by some
4949 other boot loader or by a debugger which performs
4950 these initializations itself.
4953 Modifies the behaviour of start.S when compiling a loader
4954 that is executed before the actual U-Boot. E.g. when
4955 compiling a NAND SPL.
4958 Modifies the behaviour of start.S when compiling a loader
4959 that is executed after the SPL and before the actual U-Boot.
4960 It is loaded by the SPL.
4962 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4963 Only for 85xx systems. If this variable is specified, the section
4964 .resetvec is not kept and the section .bootpg is placed in the
4965 previous 4k of the .text section.
4967 - CONFIG_ARCH_MAP_SYSMEM
4968 Generally U-Boot (and in particular the md command) uses
4969 effective address. It is therefore not necessary to regard
4970 U-Boot address as virtual addresses that need to be translated
4971 to physical addresses. However, sandbox requires this, since
4972 it maintains its own little RAM buffer which contains all
4973 addressable memory. This option causes some memory accesses
4974 to be mapped through map_sysmem() / unmap_sysmem().
4976 - CONFIG_USE_ARCH_MEMCPY
4977 CONFIG_USE_ARCH_MEMSET
4978 If these options are used a optimized version of memcpy/memset will
4979 be used if available. These functions may be faster under some
4980 conditions but may increase the binary size.
4982 - CONFIG_X86_RESET_VECTOR
4983 If defined, the x86 reset vector code is included. This is not
4984 needed when U-Boot is running from Coreboot.
4987 Defines the MPU clock speed (in MHz).
4989 NOTE : currently only supported on AM335x platforms.
4991 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4992 Enables the RTC32K OSC on AM33xx based plattforms
4994 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4995 Option to disable subpage write in NAND driver
4996 driver that uses this:
4997 drivers/mtd/nand/davinci_nand.c
4999 Freescale QE/FMAN Firmware Support:
5000 -----------------------------------
5002 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5003 loading of "firmware", which is encoded in the QE firmware binary format.
5004 This firmware often needs to be loaded during U-Boot booting, so macros
5005 are used to identify the storage device (NOR flash, SPI, etc) and the address
5008 - CONFIG_SYS_FMAN_FW_ADDR
5009 The address in the storage device where the FMAN microcode is located. The
5010 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5013 - CONFIG_SYS_QE_FW_ADDR
5014 The address in the storage device where the QE microcode is located. The
5015 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5018 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5019 The maximum possible size of the firmware. The firmware binary format
5020 has a field that specifies the actual size of the firmware, but it
5021 might not be possible to read any part of the firmware unless some
5022 local storage is allocated to hold the entire firmware first.
5024 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5025 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5026 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5027 virtual address in NOR flash.
5029 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5030 Specifies that QE/FMAN firmware is located in NAND flash.
5031 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5033 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5034 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5035 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5037 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5038 Specifies that QE/FMAN firmware is located on the primary SPI
5039 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5041 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5042 Specifies that QE/FMAN firmware is located in the remote (master)
5043 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5044 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5045 window->master inbound window->master LAW->the ucode address in
5046 master's memory space.
5048 Freescale Layerscape Management Complex Firmware Support:
5049 ---------------------------------------------------------
5050 The Freescale Layerscape Management Complex (MC) supports the loading of
5052 This firmware often needs to be loaded during U-Boot booting, so macros
5053 are used to identify the storage device (NOR flash, SPI, etc) and the address
5056 - CONFIG_FSL_MC_ENET
5057 Enable the MC driver for Layerscape SoCs.
5059 - CONFIG_SYS_LS_MC_FW_ADDR
5060 The address in the storage device where the firmware is located. The
5061 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5064 - CONFIG_SYS_LS_MC_FW_LENGTH
5065 The maximum possible size of the firmware. The firmware binary format
5066 has a field that specifies the actual size of the firmware, but it
5067 might not be possible to read any part of the firmware unless some
5068 local storage is allocated to hold the entire firmware first.
5070 - CONFIG_SYS_LS_MC_FW_IN_NOR
5071 Specifies that MC firmware is located in NOR flash, mapped as
5072 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5073 virtual address in NOR flash.
5075 Building the Software:
5076 ======================
5078 Building U-Boot has been tested in several native build environments
5079 and in many different cross environments. Of course we cannot support
5080 all possibly existing versions of cross development tools in all
5081 (potentially obsolete) versions. In case of tool chain problems we
5082 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5083 which is extensively used to build and test U-Boot.
5085 If you are not using a native environment, it is assumed that you
5086 have GNU cross compiling tools available in your path. In this case,
5087 you must set the environment variable CROSS_COMPILE in your shell.
5088 Note that no changes to the Makefile or any other source files are
5089 necessary. For example using the ELDK on a 4xx CPU, please enter:
5091 $ CROSS_COMPILE=ppc_4xx-
5092 $ export CROSS_COMPILE
5094 Note: If you wish to generate Windows versions of the utilities in
5095 the tools directory you can use the MinGW toolchain
5096 (http://www.mingw.org). Set your HOST tools to the MinGW
5097 toolchain and execute 'make tools'. For example:
5099 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5101 Binaries such as tools/mkimage.exe will be created which can
5102 be executed on computers running Windows.
5104 U-Boot is intended to be simple to build. After installing the
5105 sources you must configure U-Boot for one specific board type. This
5110 where "NAME_defconfig" is the name of one of the existing configu-
5111 rations; see boards.cfg for supported names.
5113 Note: for some board special configuration names may exist; check if
5114 additional information is available from the board vendor; for
5115 instance, the TQM823L systems are available without (standard)
5116 or with LCD support. You can select such additional "features"
5117 when choosing the configuration, i. e.
5119 make TQM823L_defconfig
5120 - will configure for a plain TQM823L, i. e. no LCD support
5122 make TQM823L_LCD_defconfig
5123 - will configure for a TQM823L with U-Boot console on LCD
5128 Finally, type "make all", and you should get some working U-Boot
5129 images ready for download to / installation on your system:
5131 - "u-boot.bin" is a raw binary image
5132 - "u-boot" is an image in ELF binary format
5133 - "u-boot.srec" is in Motorola S-Record format
5135 By default the build is performed locally and the objects are saved
5136 in the source directory. One of the two methods can be used to change
5137 this behavior and build U-Boot to some external directory:
5139 1. Add O= to the make command line invocations:
5141 make O=/tmp/build distclean
5142 make O=/tmp/build NAME_defconfig
5143 make O=/tmp/build all
5145 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5147 export KBUILD_OUTPUT=/tmp/build
5152 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5156 Please be aware that the Makefiles assume you are using GNU make, so
5157 for instance on NetBSD you might need to use "gmake" instead of
5161 If the system board that you have is not listed, then you will need
5162 to port U-Boot to your hardware platform. To do this, follow these
5165 1. Add a new configuration option for your board to the toplevel
5166 "boards.cfg" file, using the existing entries as examples.
5167 Follow the instructions there to keep the boards in order.
5168 2. Create a new directory to hold your board specific code. Add any
5169 files you need. In your board directory, you will need at least
5170 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5171 3. Create a new configuration file "include/configs/<board>.h" for
5173 3. If you're porting U-Boot to a new CPU, then also create a new
5174 directory to hold your CPU specific code. Add any files you need.
5175 4. Run "make <board>_defconfig" with your new name.
5176 5. Type "make", and you should get a working "u-boot.srec" file
5177 to be installed on your target system.
5178 6. Debug and solve any problems that might arise.
5179 [Of course, this last step is much harder than it sounds.]
5182 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5183 ==============================================================
5185 If you have modified U-Boot sources (for instance added a new board
5186 or support for new devices, a new CPU, etc.) you are expected to
5187 provide feedback to the other developers. The feedback normally takes
5188 the form of a "patch", i. e. a context diff against a certain (latest
5189 official or latest in the git repository) version of U-Boot sources.
5191 But before you submit such a patch, please verify that your modifi-
5192 cation did not break existing code. At least make sure that *ALL* of
5193 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5194 just run the "MAKEALL" script, which will configure and build U-Boot
5195 for ALL supported system. Be warned, this will take a while. You can
5196 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5197 environment variable to the script, i. e. to use the ELDK cross tools
5200 CROSS_COMPILE=ppc_8xx- MAKEALL
5202 or to build on a native PowerPC system you can type
5204 CROSS_COMPILE=' ' MAKEALL
5206 When using the MAKEALL script, the default behaviour is to build
5207 U-Boot in the source directory. This location can be changed by
5208 setting the BUILD_DIR environment variable. Also, for each target
5209 built, the MAKEALL script saves two log files (<target>.ERR and
5210 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5211 location can be changed by setting the MAKEALL_LOGDIR environment
5212 variable. For example:
5214 export BUILD_DIR=/tmp/build
5215 export MAKEALL_LOGDIR=/tmp/log
5216 CROSS_COMPILE=ppc_8xx- MAKEALL
5218 With the above settings build objects are saved in the /tmp/build,
5219 log files are saved in the /tmp/log and the source tree remains clean
5220 during the whole build process.
5223 See also "U-Boot Porting Guide" below.
5226 Monitor Commands - Overview:
5227 ============================
5229 go - start application at address 'addr'
5230 run - run commands in an environment variable
5231 bootm - boot application image from memory
5232 bootp - boot image via network using BootP/TFTP protocol
5233 bootz - boot zImage from memory
5234 tftpboot- boot image via network using TFTP protocol
5235 and env variables "ipaddr" and "serverip"
5236 (and eventually "gatewayip")
5237 tftpput - upload a file via network using TFTP protocol
5238 rarpboot- boot image via network using RARP/TFTP protocol
5239 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5240 loads - load S-Record file over serial line
5241 loadb - load binary file over serial line (kermit mode)
5243 mm - memory modify (auto-incrementing)
5244 nm - memory modify (constant address)
5245 mw - memory write (fill)
5247 cmp - memory compare
5248 crc32 - checksum calculation
5249 i2c - I2C sub-system
5250 sspi - SPI utility commands
5251 base - print or set address offset
5252 printenv- print environment variables
5253 setenv - set environment variables
5254 saveenv - save environment variables to persistent storage
5255 protect - enable or disable FLASH write protection
5256 erase - erase FLASH memory
5257 flinfo - print FLASH memory information
5258 nand - NAND memory operations (see doc/README.nand)
5259 bdinfo - print Board Info structure
5260 iminfo - print header information for application image
5261 coninfo - print console devices and informations
5262 ide - IDE sub-system
5263 loop - infinite loop on address range
5264 loopw - infinite write loop on address range
5265 mtest - simple RAM test
5266 icache - enable or disable instruction cache
5267 dcache - enable or disable data cache
5268 reset - Perform RESET of the CPU
5269 echo - echo args to console
5270 version - print monitor version
5271 help - print online help
5272 ? - alias for 'help'
5275 Monitor Commands - Detailed Description:
5276 ========================================
5280 For now: just type "help <command>".
5283 Environment Variables:
5284 ======================
5286 U-Boot supports user configuration using Environment Variables which
5287 can be made persistent by saving to Flash memory.
5289 Environment Variables are set using "setenv", printed using
5290 "printenv", and saved to Flash using "saveenv". Using "setenv"
5291 without a value can be used to delete a variable from the
5292 environment. As long as you don't save the environment you are
5293 working with an in-memory copy. In case the Flash area containing the
5294 environment is erased by accident, a default environment is provided.
5296 Some configuration options can be set using Environment Variables.
5298 List of environment variables (most likely not complete):
5300 baudrate - see CONFIG_BAUDRATE
5302 bootdelay - see CONFIG_BOOTDELAY
5304 bootcmd - see CONFIG_BOOTCOMMAND
5306 bootargs - Boot arguments when booting an RTOS image
5308 bootfile - Name of the image to load with TFTP
5310 bootm_low - Memory range available for image processing in the bootm
5311 command can be restricted. This variable is given as
5312 a hexadecimal number and defines lowest address allowed
5313 for use by the bootm command. See also "bootm_size"
5314 environment variable. Address defined by "bootm_low" is
5315 also the base of the initial memory mapping for the Linux
5316 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5319 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5320 This variable is given as a hexadecimal number and it
5321 defines the size of the memory region starting at base
5322 address bootm_low that is accessible by the Linux kernel
5323 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5324 as the default value if it is defined, and bootm_size is
5327 bootm_size - Memory range available for image processing in the bootm
5328 command can be restricted. This variable is given as
5329 a hexadecimal number and defines the size of the region
5330 allowed for use by the bootm command. See also "bootm_low"
5331 environment variable.
5333 updatefile - Location of the software update file on a TFTP server, used
5334 by the automatic software update feature. Please refer to
5335 documentation in doc/README.update for more details.
5337 autoload - if set to "no" (any string beginning with 'n'),
5338 "bootp" will just load perform a lookup of the
5339 configuration from the BOOTP server, but not try to
5340 load any image using TFTP
5342 autostart - if set to "yes", an image loaded using the "bootp",
5343 "rarpboot", "tftpboot" or "diskboot" commands will
5344 be automatically started (by internally calling
5347 If set to "no", a standalone image passed to the
5348 "bootm" command will be copied to the load address
5349 (and eventually uncompressed), but NOT be started.
5350 This can be used to load and uncompress arbitrary
5353 fdt_high - if set this restricts the maximum address that the
5354 flattened device tree will be copied into upon boot.
5355 For example, if you have a system with 1 GB memory
5356 at physical address 0x10000000, while Linux kernel
5357 only recognizes the first 704 MB as low memory, you
5358 may need to set fdt_high as 0x3C000000 to have the
5359 device tree blob be copied to the maximum address
5360 of the 704 MB low memory, so that Linux kernel can
5361 access it during the boot procedure.
5363 If this is set to the special value 0xFFFFFFFF then
5364 the fdt will not be copied at all on boot. For this
5365 to work it must reside in writable memory, have
5366 sufficient padding on the end of it for u-boot to
5367 add the information it needs into it, and the memory
5368 must be accessible by the kernel.
5370 fdtcontroladdr- if set this is the address of the control flattened
5371 device tree used by U-Boot when CONFIG_OF_CONTROL is
5374 i2cfast - (PPC405GP|PPC405EP only)
5375 if set to 'y' configures Linux I2C driver for fast
5376 mode (400kHZ). This environment variable is used in
5377 initialization code. So, for changes to be effective
5378 it must be saved and board must be reset.
5380 initrd_high - restrict positioning of initrd images:
5381 If this variable is not set, initrd images will be
5382 copied to the highest possible address in RAM; this
5383 is usually what you want since it allows for
5384 maximum initrd size. If for some reason you want to
5385 make sure that the initrd image is loaded below the
5386 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5387 variable to a value of "no" or "off" or "0".
5388 Alternatively, you can set it to a maximum upper
5389 address to use (U-Boot will still check that it
5390 does not overwrite the U-Boot stack and data).
5392 For instance, when you have a system with 16 MB
5393 RAM, and want to reserve 4 MB from use by Linux,
5394 you can do this by adding "mem=12M" to the value of
5395 the "bootargs" variable. However, now you must make
5396 sure that the initrd image is placed in the first
5397 12 MB as well - this can be done with
5399 setenv initrd_high 00c00000
5401 If you set initrd_high to 0xFFFFFFFF, this is an
5402 indication to U-Boot that all addresses are legal
5403 for the Linux kernel, including addresses in flash
5404 memory. In this case U-Boot will NOT COPY the
5405 ramdisk at all. This may be useful to reduce the
5406 boot time on your system, but requires that this
5407 feature is supported by your Linux kernel.
5409 ipaddr - IP address; needed for tftpboot command
5411 loadaddr - Default load address for commands like "bootp",
5412 "rarpboot", "tftpboot", "loadb" or "diskboot"
5414 loads_echo - see CONFIG_LOADS_ECHO
5416 serverip - TFTP server IP address; needed for tftpboot command
5418 bootretry - see CONFIG_BOOT_RETRY_TIME
5420 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5422 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5424 ethprime - controls which interface is used first.
5426 ethact - controls which interface is currently active.
5427 For example you can do the following
5429 => setenv ethact FEC
5430 => ping 192.168.0.1 # traffic sent on FEC
5431 => setenv ethact SCC
5432 => ping 10.0.0.1 # traffic sent on SCC
5434 ethrotate - When set to "no" U-Boot does not go through all
5435 available network interfaces.
5436 It just stays at the currently selected interface.
5438 netretry - When set to "no" each network operation will
5439 either succeed or fail without retrying.
5440 When set to "once" the network operation will
5441 fail when all the available network interfaces
5442 are tried once without success.
5443 Useful on scripts which control the retry operation
5446 npe_ucode - set load address for the NPE microcode
5448 silent_linux - If set then linux will be told to boot silently, by
5449 changing the console to be empty. If "yes" it will be
5450 made silent. If "no" it will not be made silent. If
5451 unset, then it will be made silent if the U-Boot console
5454 tftpsrcport - If this is set, the value is used for TFTP's
5457 tftpdstport - If this is set, the value is used for TFTP's UDP
5458 destination port instead of the Well Know Port 69.
5460 tftpblocksize - Block size to use for TFTP transfers; if not set,
5461 we use the TFTP server's default block size
5463 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5464 seconds, minimum value is 1000 = 1 second). Defines
5465 when a packet is considered to be lost so it has to
5466 be retransmitted. The default is 5000 = 5 seconds.
5467 Lowering this value may make downloads succeed
5468 faster in networks with high packet loss rates or
5469 with unreliable TFTP servers.
5471 vlan - When set to a value < 4095 the traffic over
5472 Ethernet is encapsulated/received over 802.1q
5475 The following image location variables contain the location of images
5476 used in booting. The "Image" column gives the role of the image and is
5477 not an environment variable name. The other columns are environment
5478 variable names. "File Name" gives the name of the file on a TFTP
5479 server, "RAM Address" gives the location in RAM the image will be
5480 loaded to, and "Flash Location" gives the image's address in NOR
5481 flash or offset in NAND flash.
5483 *Note* - these variables don't have to be defined for all boards, some
5484 boards currenlty use other variables for these purposes, and some
5485 boards use these variables for other purposes.
5487 Image File Name RAM Address Flash Location
5488 ----- --------- ----------- --------------
5489 u-boot u-boot u-boot_addr_r u-boot_addr
5490 Linux kernel bootfile kernel_addr_r kernel_addr
5491 device tree blob fdtfile fdt_addr_r fdt_addr
5492 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5494 The following environment variables may be used and automatically
5495 updated by the network boot commands ("bootp" and "rarpboot"),
5496 depending the information provided by your boot server:
5498 bootfile - see above
5499 dnsip - IP address of your Domain Name Server
5500 dnsip2 - IP address of your secondary Domain Name Server
5501 gatewayip - IP address of the Gateway (Router) to use
5502 hostname - Target hostname
5504 netmask - Subnet Mask
5505 rootpath - Pathname of the root filesystem on the NFS server
5506 serverip - see above
5509 There are two special Environment Variables:
5511 serial# - contains hardware identification information such
5512 as type string and/or serial number
5513 ethaddr - Ethernet address
5515 These variables can be set only once (usually during manufacturing of
5516 the board). U-Boot refuses to delete or overwrite these variables
5517 once they have been set once.
5520 Further special Environment Variables:
5522 ver - Contains the U-Boot version string as printed
5523 with the "version" command. This variable is
5524 readonly (see CONFIG_VERSION_VARIABLE).
5527 Please note that changes to some configuration parameters may take
5528 only effect after the next boot (yes, that's just like Windoze :-).
5531 Callback functions for environment variables:
5532 ---------------------------------------------
5534 For some environment variables, the behavior of u-boot needs to change
5535 when their values are changed. This functionailty allows functions to
5536 be associated with arbitrary variables. On creation, overwrite, or
5537 deletion, the callback will provide the opportunity for some side
5538 effect to happen or for the change to be rejected.
5540 The callbacks are named and associated with a function using the
5541 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5543 These callbacks are associated with variables in one of two ways. The
5544 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5545 in the board configuration to a string that defines a list of
5546 associations. The list must be in the following format:
5548 entry = variable_name[:callback_name]
5551 If the callback name is not specified, then the callback is deleted.
5552 Spaces are also allowed anywhere in the list.
5554 Callbacks can also be associated by defining the ".callbacks" variable
5555 with the same list format above. Any association in ".callbacks" will
5556 override any association in the static list. You can define
5557 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5558 ".callbacks" envirnoment variable in the default or embedded environment.
5561 Command Line Parsing:
5562 =====================
5564 There are two different command line parsers available with U-Boot:
5565 the old "simple" one, and the much more powerful "hush" shell:
5567 Old, simple command line parser:
5568 --------------------------------
5570 - supports environment variables (through setenv / saveenv commands)
5571 - several commands on one line, separated by ';'
5572 - variable substitution using "... ${name} ..." syntax
5573 - special characters ('$', ';') can be escaped by prefixing with '\',
5575 setenv bootcmd bootm \${address}
5576 - You can also escape text by enclosing in single apostrophes, for example:
5577 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5582 - similar to Bourne shell, with control structures like
5583 if...then...else...fi, for...do...done; while...do...done,
5584 until...do...done, ...
5585 - supports environment ("global") variables (through setenv / saveenv
5586 commands) and local shell variables (through standard shell syntax
5587 "name=value"); only environment variables can be used with "run"
5593 (1) If a command line (or an environment variable executed by a "run"
5594 command) contains several commands separated by semicolon, and
5595 one of these commands fails, then the remaining commands will be
5598 (2) If you execute several variables with one call to run (i. e.
5599 calling run with a list of variables as arguments), any failing
5600 command will cause "run" to terminate, i. e. the remaining
5601 variables are not executed.
5603 Note for Redundant Ethernet Interfaces:
5604 =======================================
5606 Some boards come with redundant Ethernet interfaces; U-Boot supports
5607 such configurations and is capable of automatic selection of a
5608 "working" interface when needed. MAC assignment works as follows:
5610 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5611 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5612 "eth1addr" (=>eth1), "eth2addr", ...
5614 If the network interface stores some valid MAC address (for instance
5615 in SROM), this is used as default address if there is NO correspon-
5616 ding setting in the environment; if the corresponding environment
5617 variable is set, this overrides the settings in the card; that means:
5619 o If the SROM has a valid MAC address, and there is no address in the
5620 environment, the SROM's address is used.
5622 o If there is no valid address in the SROM, and a definition in the
5623 environment exists, then the value from the environment variable is
5626 o If both the SROM and the environment contain a MAC address, and
5627 both addresses are the same, this MAC address is used.
5629 o If both the SROM and the environment contain a MAC address, and the
5630 addresses differ, the value from the environment is used and a
5633 o If neither SROM nor the environment contain a MAC address, an error
5636 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5637 will be programmed into hardware as part of the initialization process. This
5638 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5639 The naming convention is as follows:
5640 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5645 U-Boot is capable of booting (and performing other auxiliary operations on)
5646 images in two formats:
5648 New uImage format (FIT)
5649 -----------------------
5651 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5652 to Flattened Device Tree). It allows the use of images with multiple
5653 components (several kernels, ramdisks, etc.), with contents protected by
5654 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5660 Old image format is based on binary files which can be basically anything,
5661 preceded by a special header; see the definitions in include/image.h for
5662 details; basically, the header defines the following image properties:
5664 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5665 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5666 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5667 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5669 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5670 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5671 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5672 * Compression Type (uncompressed, gzip, bzip2)
5678 The header is marked by a special Magic Number, and both the header
5679 and the data portions of the image are secured against corruption by
5686 Although U-Boot should support any OS or standalone application
5687 easily, the main focus has always been on Linux during the design of
5690 U-Boot includes many features that so far have been part of some
5691 special "boot loader" code within the Linux kernel. Also, any
5692 "initrd" images to be used are no longer part of one big Linux image;
5693 instead, kernel and "initrd" are separate images. This implementation
5694 serves several purposes:
5696 - the same features can be used for other OS or standalone
5697 applications (for instance: using compressed images to reduce the
5698 Flash memory footprint)
5700 - it becomes much easier to port new Linux kernel versions because
5701 lots of low-level, hardware dependent stuff are done by U-Boot
5703 - the same Linux kernel image can now be used with different "initrd"
5704 images; of course this also means that different kernel images can
5705 be run with the same "initrd". This makes testing easier (you don't
5706 have to build a new "zImage.initrd" Linux image when you just
5707 change a file in your "initrd"). Also, a field-upgrade of the
5708 software is easier now.
5714 Porting Linux to U-Boot based systems:
5715 ---------------------------------------
5717 U-Boot cannot save you from doing all the necessary modifications to
5718 configure the Linux device drivers for use with your target hardware
5719 (no, we don't intend to provide a full virtual machine interface to
5722 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5724 Just make sure your machine specific header file (for instance
5725 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5726 Information structure as we define in include/asm-<arch>/u-boot.h,
5727 and make sure that your definition of IMAP_ADDR uses the same value
5728 as your U-Boot configuration in CONFIG_SYS_IMMR.
5730 Note that U-Boot now has a driver model, a unified model for drivers.
5731 If you are adding a new driver, plumb it into driver model. If there
5732 is no uclass available, you are encouraged to create one. See
5736 Configuring the Linux kernel:
5737 -----------------------------
5739 No specific requirements for U-Boot. Make sure you have some root
5740 device (initial ramdisk, NFS) for your target system.
5743 Building a Linux Image:
5744 -----------------------
5746 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5747 not used. If you use recent kernel source, a new build target
5748 "uImage" will exist which automatically builds an image usable by
5749 U-Boot. Most older kernels also have support for a "pImage" target,
5750 which was introduced for our predecessor project PPCBoot and uses a
5751 100% compatible format.
5755 make TQM850L_defconfig
5760 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5761 encapsulate a compressed Linux kernel image with header information,
5762 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5764 * build a standard "vmlinux" kernel image (in ELF binary format):
5766 * convert the kernel into a raw binary image:
5768 ${CROSS_COMPILE}-objcopy -O binary \
5769 -R .note -R .comment \
5770 -S vmlinux linux.bin
5772 * compress the binary image:
5776 * package compressed binary image for U-Boot:
5778 mkimage -A ppc -O linux -T kernel -C gzip \
5779 -a 0 -e 0 -n "Linux Kernel Image" \
5780 -d linux.bin.gz uImage
5783 The "mkimage" tool can also be used to create ramdisk images for use
5784 with U-Boot, either separated from the Linux kernel image, or
5785 combined into one file. "mkimage" encapsulates the images with a 64
5786 byte header containing information about target architecture,
5787 operating system, image type, compression method, entry points, time
5788 stamp, CRC32 checksums, etc.
5790 "mkimage" can be called in two ways: to verify existing images and
5791 print the header information, or to build new images.
5793 In the first form (with "-l" option) mkimage lists the information
5794 contained in the header of an existing U-Boot image; this includes
5795 checksum verification:
5797 tools/mkimage -l image
5798 -l ==> list image header information
5800 The second form (with "-d" option) is used to build a U-Boot image
5801 from a "data file" which is used as image payload:
5803 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5804 -n name -d data_file image
5805 -A ==> set architecture to 'arch'
5806 -O ==> set operating system to 'os'
5807 -T ==> set image type to 'type'
5808 -C ==> set compression type 'comp'
5809 -a ==> set load address to 'addr' (hex)
5810 -e ==> set entry point to 'ep' (hex)
5811 -n ==> set image name to 'name'
5812 -d ==> use image data from 'datafile'
5814 Right now, all Linux kernels for PowerPC systems use the same load
5815 address (0x00000000), but the entry point address depends on the
5818 - 2.2.x kernels have the entry point at 0x0000000C,
5819 - 2.3.x and later kernels have the entry point at 0x00000000.
5821 So a typical call to build a U-Boot image would read:
5823 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5824 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5825 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5826 > examples/uImage.TQM850L
5827 Image Name: 2.4.4 kernel for TQM850L
5828 Created: Wed Jul 19 02:34:59 2000
5829 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5830 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5831 Load Address: 0x00000000
5832 Entry Point: 0x00000000
5834 To verify the contents of the image (or check for corruption):
5836 -> tools/mkimage -l examples/uImage.TQM850L
5837 Image Name: 2.4.4 kernel for TQM850L
5838 Created: Wed Jul 19 02:34:59 2000
5839 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5840 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5841 Load Address: 0x00000000
5842 Entry Point: 0x00000000
5844 NOTE: for embedded systems where boot time is critical you can trade
5845 speed for memory and install an UNCOMPRESSED image instead: this
5846 needs more space in Flash, but boots much faster since it does not
5847 need to be uncompressed:
5849 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5850 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5851 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5852 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5853 > examples/uImage.TQM850L-uncompressed
5854 Image Name: 2.4.4 kernel for TQM850L
5855 Created: Wed Jul 19 02:34:59 2000
5856 Image Type: PowerPC Linux Kernel Image (uncompressed)
5857 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5858 Load Address: 0x00000000
5859 Entry Point: 0x00000000
5862 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5863 when your kernel is intended to use an initial ramdisk:
5865 -> tools/mkimage -n 'Simple Ramdisk Image' \
5866 > -A ppc -O linux -T ramdisk -C gzip \
5867 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5868 Image Name: Simple Ramdisk Image
5869 Created: Wed Jan 12 14:01:50 2000
5870 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5871 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5872 Load Address: 0x00000000
5873 Entry Point: 0x00000000
5875 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5876 option performs the converse operation of the mkimage's second form (the "-d"
5877 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5880 tools/dumpimage -i image -p position data_file
5881 -i ==> extract from the 'image' a specific 'data_file', \
5882 indexed by 'position'
5885 Installing a Linux Image:
5886 -------------------------
5888 To downloading a U-Boot image over the serial (console) interface,
5889 you must convert the image to S-Record format:
5891 objcopy -I binary -O srec examples/image examples/image.srec
5893 The 'objcopy' does not understand the information in the U-Boot
5894 image header, so the resulting S-Record file will be relative to
5895 address 0x00000000. To load it to a given address, you need to
5896 specify the target address as 'offset' parameter with the 'loads'
5899 Example: install the image to address 0x40100000 (which on the
5900 TQM8xxL is in the first Flash bank):
5902 => erase 40100000 401FFFFF
5908 ## Ready for S-Record download ...
5909 ~>examples/image.srec
5910 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5912 15989 15990 15991 15992
5913 [file transfer complete]
5915 ## Start Addr = 0x00000000
5918 You can check the success of the download using the 'iminfo' command;
5919 this includes a checksum verification so you can be sure no data
5920 corruption happened:
5924 ## Checking Image at 40100000 ...
5925 Image Name: 2.2.13 for initrd on TQM850L
5926 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5927 Data Size: 335725 Bytes = 327 kB = 0 MB
5928 Load Address: 00000000
5929 Entry Point: 0000000c
5930 Verifying Checksum ... OK
5936 The "bootm" command is used to boot an application that is stored in
5937 memory (RAM or Flash). In case of a Linux kernel image, the contents
5938 of the "bootargs" environment variable is passed to the kernel as
5939 parameters. You can check and modify this variable using the
5940 "printenv" and "setenv" commands:
5943 => printenv bootargs
5944 bootargs=root=/dev/ram
5946 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5948 => printenv bootargs
5949 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5952 ## Booting Linux kernel at 40020000 ...
5953 Image Name: 2.2.13 for NFS on TQM850L
5954 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5955 Data Size: 381681 Bytes = 372 kB = 0 MB
5956 Load Address: 00000000
5957 Entry Point: 0000000c
5958 Verifying Checksum ... OK
5959 Uncompressing Kernel Image ... OK
5960 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
5961 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5962 time_init: decrementer frequency = 187500000/60
5963 Calibrating delay loop... 49.77 BogoMIPS
5964 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5967 If you want to boot a Linux kernel with initial RAM disk, you pass
5968 the memory addresses of both the kernel and the initrd image (PPBCOOT
5969 format!) to the "bootm" command:
5971 => imi 40100000 40200000
5973 ## Checking Image at 40100000 ...
5974 Image Name: 2.2.13 for initrd on TQM850L
5975 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5976 Data Size: 335725 Bytes = 327 kB = 0 MB
5977 Load Address: 00000000
5978 Entry Point: 0000000c
5979 Verifying Checksum ... OK
5981 ## Checking Image at 40200000 ...
5982 Image Name: Simple Ramdisk Image
5983 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5984 Data Size: 566530 Bytes = 553 kB = 0 MB
5985 Load Address: 00000000
5986 Entry Point: 00000000
5987 Verifying Checksum ... OK
5989 => bootm 40100000 40200000
5990 ## Booting Linux kernel at 40100000 ...
5991 Image Name: 2.2.13 for initrd on TQM850L
5992 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5993 Data Size: 335725 Bytes = 327 kB = 0 MB
5994 Load Address: 00000000
5995 Entry Point: 0000000c
5996 Verifying Checksum ... OK
5997 Uncompressing Kernel Image ... OK
5998 ## Loading RAMDisk Image at 40200000 ...
5999 Image Name: Simple Ramdisk Image
6000 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6001 Data Size: 566530 Bytes = 553 kB = 0 MB
6002 Load Address: 00000000
6003 Entry Point: 00000000
6004 Verifying Checksum ... OK
6005 Loading Ramdisk ... OK
6006 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
6007 Boot arguments: root=/dev/ram
6008 time_init: decrementer frequency = 187500000/60
6009 Calibrating delay loop... 49.77 BogoMIPS
6011 RAMDISK: Compressed image found at block 0
6012 VFS: Mounted root (ext2 filesystem).
6016 Boot Linux and pass a flat device tree:
6019 First, U-Boot must be compiled with the appropriate defines. See the section
6020 titled "Linux Kernel Interface" above for a more in depth explanation. The
6021 following is an example of how to start a kernel and pass an updated
6027 oft=oftrees/mpc8540ads.dtb
6028 => tftp $oftaddr $oft
6029 Speed: 1000, full duplex
6031 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6032 Filename 'oftrees/mpc8540ads.dtb'.
6033 Load address: 0x300000
6036 Bytes transferred = 4106 (100a hex)
6037 => tftp $loadaddr $bootfile
6038 Speed: 1000, full duplex
6040 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6042 Load address: 0x200000
6043 Loading:############
6045 Bytes transferred = 1029407 (fb51f hex)
6050 => bootm $loadaddr - $oftaddr
6051 ## Booting image at 00200000 ...
6052 Image Name: Linux-2.6.17-dirty
6053 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6054 Data Size: 1029343 Bytes = 1005.2 kB
6055 Load Address: 00000000
6056 Entry Point: 00000000
6057 Verifying Checksum ... OK
6058 Uncompressing Kernel Image ... OK
6059 Booting using flat device tree at 0x300000
6060 Using MPC85xx ADS machine description
6061 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6065 More About U-Boot Image Types:
6066 ------------------------------
6068 U-Boot supports the following image types:
6070 "Standalone Programs" are directly runnable in the environment
6071 provided by U-Boot; it is expected that (if they behave
6072 well) you can continue to work in U-Boot after return from
6073 the Standalone Program.
6074 "OS Kernel Images" are usually images of some Embedded OS which
6075 will take over control completely. Usually these programs
6076 will install their own set of exception handlers, device
6077 drivers, set up the MMU, etc. - this means, that you cannot
6078 expect to re-enter U-Boot except by resetting the CPU.
6079 "RAMDisk Images" are more or less just data blocks, and their
6080 parameters (address, size) are passed to an OS kernel that is
6082 "Multi-File Images" contain several images, typically an OS
6083 (Linux) kernel image and one or more data images like
6084 RAMDisks. This construct is useful for instance when you want
6085 to boot over the network using BOOTP etc., where the boot
6086 server provides just a single image file, but you want to get
6087 for instance an OS kernel and a RAMDisk image.
6089 "Multi-File Images" start with a list of image sizes, each
6090 image size (in bytes) specified by an "uint32_t" in network
6091 byte order. This list is terminated by an "(uint32_t)0".
6092 Immediately after the terminating 0 follow the images, one by
6093 one, all aligned on "uint32_t" boundaries (size rounded up to
6094 a multiple of 4 bytes).
6096 "Firmware Images" are binary images containing firmware (like
6097 U-Boot or FPGA images) which usually will be programmed to
6100 "Script files" are command sequences that will be executed by
6101 U-Boot's command interpreter; this feature is especially
6102 useful when you configure U-Boot to use a real shell (hush)
6103 as command interpreter.
6105 Booting the Linux zImage:
6106 -------------------------
6108 On some platforms, it's possible to boot Linux zImage. This is done
6109 using the "bootz" command. The syntax of "bootz" command is the same
6110 as the syntax of "bootm" command.
6112 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6113 kernel with raw initrd images. The syntax is slightly different, the
6114 address of the initrd must be augmented by it's size, in the following
6115 format: "<initrd addres>:<initrd size>".
6121 One of the features of U-Boot is that you can dynamically load and
6122 run "standalone" applications, which can use some resources of
6123 U-Boot like console I/O functions or interrupt services.
6125 Two simple examples are included with the sources:
6130 'examples/hello_world.c' contains a small "Hello World" Demo
6131 application; it is automatically compiled when you build U-Boot.
6132 It's configured to run at address 0x00040004, so you can play with it
6136 ## Ready for S-Record download ...
6137 ~>examples/hello_world.srec
6138 1 2 3 4 5 6 7 8 9 10 11 ...
6139 [file transfer complete]
6141 ## Start Addr = 0x00040004
6143 => go 40004 Hello World! This is a test.
6144 ## Starting application at 0x00040004 ...
6155 Hit any key to exit ...
6157 ## Application terminated, rc = 0x0
6159 Another example, which demonstrates how to register a CPM interrupt
6160 handler with the U-Boot code, can be found in 'examples/timer.c'.
6161 Here, a CPM timer is set up to generate an interrupt every second.
6162 The interrupt service routine is trivial, just printing a '.'
6163 character, but this is just a demo program. The application can be
6164 controlled by the following keys:
6166 ? - print current values og the CPM Timer registers
6167 b - enable interrupts and start timer
6168 e - stop timer and disable interrupts
6169 q - quit application
6172 ## Ready for S-Record download ...
6173 ~>examples/timer.srec
6174 1 2 3 4 5 6 7 8 9 10 11 ...
6175 [file transfer complete]
6177 ## Start Addr = 0x00040004
6180 ## Starting application at 0x00040004 ...
6183 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6186 [q, b, e, ?] Set interval 1000000 us
6189 [q, b, e, ?] ........
6190 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6193 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6196 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6199 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6201 [q, b, e, ?] ...Stopping timer
6203 [q, b, e, ?] ## Application terminated, rc = 0x0
6209 Over time, many people have reported problems when trying to use the
6210 "minicom" terminal emulation program for serial download. I (wd)
6211 consider minicom to be broken, and recommend not to use it. Under
6212 Unix, I recommend to use C-Kermit for general purpose use (and
6213 especially for kermit binary protocol download ("loadb" command), and
6214 use "cu" for S-Record download ("loads" command). See
6215 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6216 for help with kermit.
6219 Nevertheless, if you absolutely want to use it try adding this
6220 configuration to your "File transfer protocols" section:
6222 Name Program Name U/D FullScr IO-Red. Multi
6223 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6224 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6230 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6231 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6233 Building requires a cross environment; it is known to work on
6234 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6235 need gmake since the Makefiles are not compatible with BSD make).
6236 Note that the cross-powerpc package does not install include files;
6237 attempting to build U-Boot will fail because <machine/ansi.h> is
6238 missing. This file has to be installed and patched manually:
6240 # cd /usr/pkg/cross/powerpc-netbsd/include
6242 # ln -s powerpc machine
6243 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6244 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6246 Native builds *don't* work due to incompatibilities between native
6247 and U-Boot include files.
6249 Booting assumes that (the first part of) the image booted is a
6250 stage-2 loader which in turn loads and then invokes the kernel
6251 proper. Loader sources will eventually appear in the NetBSD source
6252 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6253 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6256 Implementation Internals:
6257 =========================
6259 The following is not intended to be a complete description of every
6260 implementation detail. However, it should help to understand the
6261 inner workings of U-Boot and make it easier to port it to custom
6265 Initial Stack, Global Data:
6266 ---------------------------
6268 The implementation of U-Boot is complicated by the fact that U-Boot
6269 starts running out of ROM (flash memory), usually without access to
6270 system RAM (because the memory controller is not initialized yet).
6271 This means that we don't have writable Data or BSS segments, and BSS
6272 is not initialized as zero. To be able to get a C environment working
6273 at all, we have to allocate at least a minimal stack. Implementation
6274 options for this are defined and restricted by the CPU used: Some CPU
6275 models provide on-chip memory (like the IMMR area on MPC8xx and
6276 MPC826x processors), on others (parts of) the data cache can be
6277 locked as (mis-) used as memory, etc.
6279 Chris Hallinan posted a good summary of these issues to the
6280 U-Boot mailing list:
6282 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6283 From: "Chris Hallinan" <clh@net1plus.com>
6284 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6287 Correct me if I'm wrong, folks, but the way I understand it
6288 is this: Using DCACHE as initial RAM for Stack, etc, does not
6289 require any physical RAM backing up the cache. The cleverness
6290 is that the cache is being used as a temporary supply of
6291 necessary storage before the SDRAM controller is setup. It's
6292 beyond the scope of this list to explain the details, but you
6293 can see how this works by studying the cache architecture and
6294 operation in the architecture and processor-specific manuals.
6296 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6297 is another option for the system designer to use as an
6298 initial stack/RAM area prior to SDRAM being available. Either
6299 option should work for you. Using CS 4 should be fine if your
6300 board designers haven't used it for something that would
6301 cause you grief during the initial boot! It is frequently not
6304 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6305 with your processor/board/system design. The default value
6306 you will find in any recent u-boot distribution in
6307 walnut.h should work for you. I'd set it to a value larger
6308 than your SDRAM module. If you have a 64MB SDRAM module, set
6309 it above 400_0000. Just make sure your board has no resources
6310 that are supposed to respond to that address! That code in
6311 start.S has been around a while and should work as is when
6312 you get the config right.
6317 It is essential to remember this, since it has some impact on the C
6318 code for the initialization procedures:
6320 * Initialized global data (data segment) is read-only. Do not attempt
6323 * Do not use any uninitialized global data (or implicitely initialized
6324 as zero data - BSS segment) at all - this is undefined, initiali-
6325 zation is performed later (when relocating to RAM).
6327 * Stack space is very limited. Avoid big data buffers or things like
6330 Having only the stack as writable memory limits means we cannot use
6331 normal global data to share information beween the code. But it
6332 turned out that the implementation of U-Boot can be greatly
6333 simplified by making a global data structure (gd_t) available to all
6334 functions. We could pass a pointer to this data as argument to _all_
6335 functions, but this would bloat the code. Instead we use a feature of
6336 the GCC compiler (Global Register Variables) to share the data: we
6337 place a pointer (gd) to the global data into a register which we
6338 reserve for this purpose.
6340 When choosing a register for such a purpose we are restricted by the
6341 relevant (E)ABI specifications for the current architecture, and by
6342 GCC's implementation.
6344 For PowerPC, the following registers have specific use:
6346 R2: reserved for system use
6347 R3-R4: parameter passing and return values
6348 R5-R10: parameter passing
6349 R13: small data area pointer
6353 (U-Boot also uses R12 as internal GOT pointer. r12
6354 is a volatile register so r12 needs to be reset when
6355 going back and forth between asm and C)
6357 ==> U-Boot will use R2 to hold a pointer to the global data
6359 Note: on PPC, we could use a static initializer (since the
6360 address of the global data structure is known at compile time),
6361 but it turned out that reserving a register results in somewhat
6362 smaller code - although the code savings are not that big (on
6363 average for all boards 752 bytes for the whole U-Boot image,
6364 624 text + 127 data).
6366 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6367 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6369 ==> U-Boot will use P3 to hold a pointer to the global data
6371 On ARM, the following registers are used:
6373 R0: function argument word/integer result
6374 R1-R3: function argument word
6375 R9: platform specific
6376 R10: stack limit (used only if stack checking is enabled)
6377 R11: argument (frame) pointer
6378 R12: temporary workspace
6381 R15: program counter
6383 ==> U-Boot will use R9 to hold a pointer to the global data
6385 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6387 On Nios II, the ABI is documented here:
6388 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6390 ==> U-Boot will use gp to hold a pointer to the global data
6392 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6393 to access small data sections, so gp is free.
6395 On NDS32, the following registers are used:
6397 R0-R1: argument/return
6399 R15: temporary register for assembler
6400 R16: trampoline register
6401 R28: frame pointer (FP)
6402 R29: global pointer (GP)
6403 R30: link register (LP)
6404 R31: stack pointer (SP)
6405 PC: program counter (PC)
6407 ==> U-Boot will use R10 to hold a pointer to the global data
6409 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6410 or current versions of GCC may "optimize" the code too much.
6415 U-Boot runs in system state and uses physical addresses, i.e. the
6416 MMU is not used either for address mapping nor for memory protection.
6418 The available memory is mapped to fixed addresses using the memory
6419 controller. In this process, a contiguous block is formed for each
6420 memory type (Flash, SDRAM, SRAM), even when it consists of several
6421 physical memory banks.
6423 U-Boot is installed in the first 128 kB of the first Flash bank (on
6424 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6425 booting and sizing and initializing DRAM, the code relocates itself
6426 to the upper end of DRAM. Immediately below the U-Boot code some
6427 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6428 configuration setting]. Below that, a structure with global Board
6429 Info data is placed, followed by the stack (growing downward).
6431 Additionally, some exception handler code is copied to the low 8 kB
6432 of DRAM (0x00000000 ... 0x00001FFF).
6434 So a typical memory configuration with 16 MB of DRAM could look like
6437 0x0000 0000 Exception Vector code
6440 0x0000 2000 Free for Application Use
6446 0x00FB FF20 Monitor Stack (Growing downward)
6447 0x00FB FFAC Board Info Data and permanent copy of global data
6448 0x00FC 0000 Malloc Arena
6451 0x00FE 0000 RAM Copy of Monitor Code
6452 ... eventually: LCD or video framebuffer
6453 ... eventually: pRAM (Protected RAM - unchanged by reset)
6454 0x00FF FFFF [End of RAM]
6457 System Initialization:
6458 ----------------------
6460 In the reset configuration, U-Boot starts at the reset entry point
6461 (on most PowerPC systems at address 0x00000100). Because of the reset
6462 configuration for CS0# this is a mirror of the onboard Flash memory.
6463 To be able to re-map memory U-Boot then jumps to its link address.
6464 To be able to implement the initialization code in C, a (small!)
6465 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6466 which provide such a feature like MPC8xx or MPC8260), or in a locked
6467 part of the data cache. After that, U-Boot initializes the CPU core,
6468 the caches and the SIU.
6470 Next, all (potentially) available memory banks are mapped using a
6471 preliminary mapping. For example, we put them on 512 MB boundaries
6472 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6473 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6474 programmed for SDRAM access. Using the temporary configuration, a
6475 simple memory test is run that determines the size of the SDRAM
6478 When there is more than one SDRAM bank, and the banks are of
6479 different size, the largest is mapped first. For equal size, the first
6480 bank (CS2#) is mapped first. The first mapping is always for address
6481 0x00000000, with any additional banks following immediately to create
6482 contiguous memory starting from 0.
6484 Then, the monitor installs itself at the upper end of the SDRAM area
6485 and allocates memory for use by malloc() and for the global Board
6486 Info data; also, the exception vector code is copied to the low RAM
6487 pages, and the final stack is set up.
6489 Only after this relocation will you have a "normal" C environment;
6490 until that you are restricted in several ways, mostly because you are
6491 running from ROM, and because the code will have to be relocated to a
6495 U-Boot Porting Guide:
6496 ----------------------
6498 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6502 int main(int argc, char *argv[])
6504 sighandler_t no_more_time;
6506 signal(SIGALRM, no_more_time);
6507 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6509 if (available_money > available_manpower) {
6510 Pay consultant to port U-Boot;
6514 Download latest U-Boot source;
6516 Subscribe to u-boot mailing list;
6519 email("Hi, I am new to U-Boot, how do I get started?");
6522 Read the README file in the top level directory;
6523 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6524 Read applicable doc/*.README;
6525 Read the source, Luke;
6526 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6529 if (available_money > toLocalCurrency ($2500))
6532 Add a lot of aggravation and time;
6534 if (a similar board exists) { /* hopefully... */
6535 cp -a board/<similar> board/<myboard>
6536 cp include/configs/<similar>.h include/configs/<myboard>.h
6538 Create your own board support subdirectory;
6539 Create your own board include/configs/<myboard>.h file;
6541 Edit new board/<myboard> files
6542 Edit new include/configs/<myboard>.h
6547 Add / modify source code;
6551 email("Hi, I am having problems...");
6553 Send patch file to the U-Boot email list;
6554 if (reasonable critiques)
6555 Incorporate improvements from email list code review;
6557 Defend code as written;
6563 void no_more_time (int sig)
6572 All contributions to U-Boot should conform to the Linux kernel
6573 coding style; see the file "Documentation/CodingStyle" and the script
6574 "scripts/Lindent" in your Linux kernel source directory.
6576 Source files originating from a different project (for example the
6577 MTD subsystem) are generally exempt from these guidelines and are not
6578 reformated to ease subsequent migration to newer versions of those
6581 Please note that U-Boot is implemented in C (and to some small parts in
6582 Assembler); no C++ is used, so please do not use C++ style comments (//)
6585 Please also stick to the following formatting rules:
6586 - remove any trailing white space
6587 - use TAB characters for indentation and vertical alignment, not spaces
6588 - make sure NOT to use DOS '\r\n' line feeds
6589 - do not add more than 2 consecutive empty lines to source files
6590 - do not add trailing empty lines to source files
6592 Submissions which do not conform to the standards may be returned
6593 with a request to reformat the changes.
6599 Since the number of patches for U-Boot is growing, we need to
6600 establish some rules. Submissions which do not conform to these rules
6601 may be rejected, even when they contain important and valuable stuff.
6603 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6605 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6606 see http://lists.denx.de/mailman/listinfo/u-boot
6608 When you send a patch, please include the following information with
6611 * For bug fixes: a description of the bug and how your patch fixes
6612 this bug. Please try to include a way of demonstrating that the
6613 patch actually fixes something.
6615 * For new features: a description of the feature and your
6618 * A CHANGELOG entry as plaintext (separate from the patch)
6620 * For major contributions, your entry to the CREDITS file
6622 * When you add support for a new board, don't forget to add a
6623 maintainer e-mail address to the boards.cfg file, too.
6625 * If your patch adds new configuration options, don't forget to
6626 document these in the README file.
6628 * The patch itself. If you are using git (which is *strongly*
6629 recommended) you can easily generate the patch using the
6630 "git format-patch". If you then use "git send-email" to send it to
6631 the U-Boot mailing list, you will avoid most of the common problems
6632 with some other mail clients.
6634 If you cannot use git, use "diff -purN OLD NEW". If your version of
6635 diff does not support these options, then get the latest version of
6638 The current directory when running this command shall be the parent
6639 directory of the U-Boot source tree (i. e. please make sure that
6640 your patch includes sufficient directory information for the
6643 We prefer patches as plain text. MIME attachments are discouraged,
6644 and compressed attachments must not be used.
6646 * If one logical set of modifications affects or creates several
6647 files, all these changes shall be submitted in a SINGLE patch file.
6649 * Changesets that contain different, unrelated modifications shall be
6650 submitted as SEPARATE patches, one patch per changeset.
6655 * Before sending the patch, run the MAKEALL script on your patched
6656 source tree and make sure that no errors or warnings are reported
6657 for any of the boards.
6659 * Keep your modifications to the necessary minimum: A patch
6660 containing several unrelated changes or arbitrary reformats will be
6661 returned with a request to re-formatting / split it.
6663 * If you modify existing code, make sure that your new code does not
6664 add to the memory footprint of the code ;-) Small is beautiful!
6665 When adding new features, these should compile conditionally only
6666 (using #ifdef), and the resulting code with the new feature
6667 disabled must not need more memory than the old code without your
6670 * Remember that there is a size limit of 100 kB per message on the
6671 u-boot mailing list. Bigger patches will be moderated. If they are
6672 reasonable and not too big, they will be acknowledged. But patches
6673 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob