2 # (C) Copyright 2000 - 2013
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
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_defconfig".
257 Example: For a TQM823L module type:
260 make TQM823L_defconfig
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
264 directory according to the instructions in cogent/README.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Marvell Family Member
325 CONFIG_SYS_MVFS - define it if you want to enable
326 multiple fs option at one time
327 for marvell soc family
329 - MPC824X Family Member (if CONFIG_MPC824X is defined)
330 Define exactly one of
331 CONFIG_MPC8240, CONFIG_MPC8245
333 - 8xx CPU Options: (if using an MPC8xx CPU)
334 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
335 get_gclk_freq() cannot work
336 e.g. if there is no 32KHz
337 reference PIT/RTC clock
338 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
341 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
342 CONFIG_SYS_8xx_CPUCLK_MIN
343 CONFIG_SYS_8xx_CPUCLK_MAX
344 CONFIG_8xx_CPUCLK_DEFAULT
345 See doc/README.MPC866
347 CONFIG_SYS_MEASURE_CPUCLK
349 Define this to measure the actual CPU clock instead
350 of relying on the correctness of the configured
351 values. Mostly useful for board bringup to make sure
352 the PLL is locked at the intended frequency. Note
353 that this requires a (stable) reference clock (32 kHz
354 RTC clock or CONFIG_SYS_8XX_XIN)
356 CONFIG_SYS_DELAYED_ICACHE
358 Define this option if you want to enable the
359 ICache only when Code runs from RAM.
364 Specifies that the core is a 64-bit PowerPC implementation (implements
365 the "64" category of the Power ISA). This is necessary for ePAPR
366 compliance, among other possible reasons.
368 CONFIG_SYS_FSL_TBCLK_DIV
370 Defines the core time base clock divider ratio compared to the
371 system clock. On most PQ3 devices this is 8, on newer QorIQ
372 devices it can be 16 or 32. The ratio varies from SoC to Soc.
374 CONFIG_SYS_FSL_PCIE_COMPAT
376 Defines the string to utilize when trying to match PCIe device
377 tree nodes for the given platform.
379 CONFIG_SYS_PPC_E500_DEBUG_TLB
381 Enables a temporary TLB entry to be used during boot to work
382 around limitations in e500v1 and e500v2 external debugger
383 support. This reduces the portions of the boot code where
384 breakpoints and single stepping do not work. The value of this
385 symbol should be set to the TLB1 entry to be used for this
388 CONFIG_SYS_FSL_ERRATUM_A004510
390 Enables a workaround for erratum A004510. If set,
391 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
392 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
394 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
395 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
397 Defines one or two SoC revisions (low 8 bits of SVR)
398 for which the A004510 workaround should be applied.
400 The rest of SVR is either not relevant to the decision
401 of whether the erratum is present (e.g. p2040 versus
402 p2041) or is implied by the build target, which controls
403 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
405 See Freescale App Note 4493 for more information about
408 CONFIG_A003399_NOR_WORKAROUND
409 Enables a workaround for IFC erratum A003399. It is only
410 requred during NOR boot.
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 CONFIG_SYS_FSL_DSP_DDR_ADDR
418 This value denotes start offset of DDR memory which is
419 connected exclusively to the DSP cores.
421 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
422 This value denotes start offset of M2 memory
423 which is directly connected to the DSP core.
425 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
426 This value denotes start offset of M3 memory which is directly
427 connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
433 Single Source Clock is clocking mode present in some of FSL SoC's.
434 In this mode, a single differential clock is used to supply
435 clocks to the sysclock, ddrclock and usbclock.
437 CONFIG_SYS_CPC_REINIT_F
438 This CONFIG is defined when the CPC is configured as SRAM at the
439 time of U-boot entry and is required to be re-initialized.
442 Inidcates this SoC supports deep sleep feature. If deep sleep is
443 supported, core will start to execute uboot when wakes up.
445 - Generic CPU options:
446 CONFIG_SYS_GENERIC_GLOBAL_DATA
447 Defines global data is initialized in generic board board_init_f().
448 If this macro is defined, global data is created and cleared in
449 generic board board_init_f(). Without this macro, architecture/board
450 should initialize global data before calling board_init_f().
452 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
454 Defines the endianess of the CPU. Implementation of those
455 values is arch specific.
458 Freescale DDR driver in use. This type of DDR controller is
459 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
462 CONFIG_SYS_FSL_DDR_ADDR
463 Freescale DDR memory-mapped register base.
465 CONFIG_SYS_FSL_DDR_EMU
466 Specify emulator support for DDR. Some DDR features such as
467 deskew training are not available.
469 CONFIG_SYS_FSL_DDRC_GEN1
470 Freescale DDR1 controller.
472 CONFIG_SYS_FSL_DDRC_GEN2
473 Freescale DDR2 controller.
475 CONFIG_SYS_FSL_DDRC_GEN3
476 Freescale DDR3 controller.
478 CONFIG_SYS_FSL_DDRC_GEN4
479 Freescale DDR4 controller.
481 CONFIG_SYS_FSL_DDRC_ARM_GEN3
482 Freescale DDR3 controller for ARM-based SoCs.
485 Board config to use DDR1. It can be enabled for SoCs with
486 Freescale DDR1 or DDR2 controllers, depending on the board
490 Board config to use DDR2. It can be eanbeld for SoCs with
491 Freescale DDR2 or DDR3 controllers, depending on the board
495 Board config to use DDR3. It can be enabled for SoCs with
496 Freescale DDR3 or DDR3L controllers.
499 Board config to use DDR3L. It can be enabled for SoCs with
503 Board config to use DDR4. It can be enabled for SoCs with
506 CONFIG_SYS_FSL_IFC_BE
507 Defines the IFC controller register space as Big Endian
509 CONFIG_SYS_FSL_IFC_LE
510 Defines the IFC controller register space as Little Endian
512 CONFIG_SYS_FSL_PBL_PBI
513 It enables addition of RCW (Power on reset configuration) in built image.
514 Please refer doc/README.pblimage for more details
516 CONFIG_SYS_FSL_PBL_RCW
517 It adds PBI(pre-boot instructions) commands in u-boot build image.
518 PBI commands can be used to configure SoC before it starts the execution.
519 Please refer doc/README.pblimage for more details
522 It adds a target to create boot binary having SPL binary in PBI format
523 concatenated with u-boot binary.
525 CONFIG_SYS_FSL_DDR_BE
526 Defines the DDR controller register space as Big Endian
528 CONFIG_SYS_FSL_DDR_LE
529 Defines the DDR controller register space as Little Endian
531 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
532 Physical address from the view of DDR controllers. It is the
533 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
534 it could be different for ARM SoCs.
536 CONFIG_SYS_FSL_DDR_INTLV_256B
537 DDR controller interleaving on 256-byte. This is a special
538 interleaving mode, handled by Dickens for Freescale layerscape
541 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
542 Number of controllers used as main memory.
544 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
545 Number of controllers used for other than main memory.
547 CONFIG_SYS_FSL_SEC_BE
548 Defines the SEC controller register space as Big Endian
550 CONFIG_SYS_FSL_SEC_LE
551 Defines the SEC controller register space as Little Endian
553 - Intel Monahans options:
554 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
556 Defines the Monahans run mode to oscillator
557 ratio. Valid values are 8, 16, 24, 31. The core
558 frequency is this value multiplied by 13 MHz.
560 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
562 Defines the Monahans turbo mode to oscillator
563 ratio. Valid values are 1 (default if undefined) and
564 2. The core frequency as calculated above is multiplied
568 CONFIG_SYS_INIT_SP_OFFSET
570 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
571 pointer. This is needed for the temporary stack before
574 CONFIG_SYS_MIPS_CACHE_MODE
576 Cache operation mode for the MIPS CPU.
577 See also arch/mips/include/asm/mipsregs.h.
579 CONF_CM_CACHABLE_NO_WA
582 CONF_CM_CACHABLE_NONCOHERENT
586 CONF_CM_CACHABLE_ACCELERATED
588 CONFIG_SYS_XWAY_EBU_BOOTCFG
590 Special option for Lantiq XWAY SoCs for booting from NOR flash.
591 See also arch/mips/cpu/mips32/start.S.
593 CONFIG_XWAY_SWAP_BYTES
595 Enable compilation of tools/xway-swap-bytes needed for Lantiq
596 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
597 be swapped if a flash programmer is used.
600 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
602 Select high exception vectors of the ARM core, e.g., do not
603 clear the V bit of the c1 register of CP15.
605 CONFIG_SYS_THUMB_BUILD
607 Use this flag to build U-Boot using the Thumb instruction
608 set for ARM architectures. Thumb instruction set provides
609 better code density. For ARM architectures that support
610 Thumb2 this flag will result in Thumb2 code generated by
613 CONFIG_ARM_ERRATA_716044
614 CONFIG_ARM_ERRATA_742230
615 CONFIG_ARM_ERRATA_743622
616 CONFIG_ARM_ERRATA_751472
617 CONFIG_ARM_ERRATA_794072
618 CONFIG_ARM_ERRATA_761320
620 If set, the workarounds for these ARM errata are applied early
621 during U-Boot startup. Note that these options force the
622 workarounds to be applied; no CPU-type/version detection
623 exists, unlike the similar options in the Linux kernel. Do not
624 set these options unless they apply!
627 Driver model is a new framework for devices in U-Boot
628 introduced in early 2014. U-Boot is being progressively
629 moved over to this. It offers a consistent device structure,
630 supports grouping devices into classes and has built-in
631 handling of platform data and device tree.
633 To enable transition to driver model in a relatively
634 painful fashion, each subsystem can be independently
635 switched between the legacy/ad-hoc approach and the new
636 driver model using the options below. Also, many uclass
637 interfaces include compatibility features which may be
638 removed once the conversion of that subsystem is complete.
639 As a result, the API provided by the subsystem may in fact
640 not change with driver model.
642 See doc/driver-model/README.txt for more information.
646 Enable driver model. This brings in the core support,
647 including scanning of platform data on start-up. If
648 CONFIG_OF_CONTROL is enabled, the device tree will be
649 scanned also when available.
653 Enable driver model test commands. These allow you to print
654 out the driver model tree and the uclasses.
658 Enable some demo devices and the 'demo' command. These are
659 really only useful for playing around while trying to
660 understand driver model in sandbox.
664 Enable driver model in SPL. You will need to provide a
665 suitable malloc() implementation. If you are not using the
666 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
667 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
668 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
669 In most cases driver model will only allocate a few uclasses
670 and devices in SPL, so 1KB should be enable. See
671 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
676 Enable driver model for serial. This replaces
677 drivers/serial/serial.c with the serial uclass, which
678 implements serial_putc() etc. The uclass interface is
679 defined in include/serial.h.
683 Enable driver model for GPIO access. The standard GPIO
684 interface (gpio_get_value(), etc.) is then implemented by
685 the GPIO uclass. Drivers provide methods to query the
686 particular GPIOs that they provide. The uclass interface
687 is defined in include/asm-generic/gpio.h.
691 Enable driver model for SPI. The SPI slave interface
692 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
693 the SPI uclass. Drivers provide methods to access the SPI
694 buses that they control. The uclass interface is defined in
695 include/spi.h. The existing spi_slave structure is attached
696 as 'parent data' to every slave on each bus. Slaves
697 typically use driver-private data instead of extending the
702 Enable driver model for SPI flash. This SPI flash interface
703 (spi_flash_probe(), spi_flash_write(), etc.) is then
704 implemented by the SPI flash uclass. There is one standard
705 SPI flash driver which knows how to probe most chips
706 supported by U-Boot. The uclass interface is defined in
707 include/spi_flash.h, but is currently fully compatible
708 with the old interface to avoid confusion and duplication
709 during the transition parent. SPI and SPI flash must be
710 enabled together (it is not possible to use driver model
711 for one and not the other).
715 Enable driver model for the Chrome OS EC interface. This
716 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
717 but otherwise makes few changes. Since cros_ec also supports
718 I2C and LPC (which don't support driver model yet), a full
719 conversion is not yet possible.
722 ** Code size options: The following options are enabled by
723 default except in SPL. Enable them explicitly to get these
728 Enable the dm_warn() function. This can use up quite a bit
729 of space for its strings.
733 Enable registering a serial device with the stdio library.
735 CONFIG_DM_DEVICE_REMOVE
737 Enable removing of devices.
740 - Linux Kernel Interface:
743 U-Boot stores all clock information in Hz
744 internally. For binary compatibility with older Linux
745 kernels (which expect the clocks passed in the
746 bd_info data to be in MHz) the environment variable
747 "clocks_in_mhz" can be defined so that U-Boot
748 converts clock data to MHZ before passing it to the
750 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
751 "clocks_in_mhz=1" is automatically included in the
754 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
756 When transferring memsize parameter to linux, some versions
757 expect it to be in bytes, others in MB.
758 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
762 New kernel versions are expecting firmware settings to be
763 passed using flattened device trees (based on open firmware
767 * New libfdt-based support
768 * Adds the "fdt" command
769 * The bootm command automatically updates the fdt
771 OF_CPU - The proper name of the cpus node (only required for
772 MPC512X and MPC5xxx based boards).
773 OF_SOC - The proper name of the soc node (only required for
774 MPC512X and MPC5xxx based boards).
775 OF_TBCLK - The timebase frequency.
776 OF_STDOUT_PATH - The path to the console device
778 boards with QUICC Engines require OF_QE to set UCC MAC
781 CONFIG_OF_BOARD_SETUP
783 Board code has addition modification that it wants to make
784 to the flat device tree before handing it off to the kernel
788 This define fills in the correct boot CPU in the boot
789 param header, the default value is zero if undefined.
793 U-Boot can detect if an IDE device is present or not.
794 If not, and this new config option is activated, U-Boot
795 removes the ATA node from the DTS before booting Linux,
796 so the Linux IDE driver does not probe the device and
797 crash. This is needed for buggy hardware (uc101) where
798 no pull down resistor is connected to the signal IDE5V_DD7.
800 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
802 This setting is mandatory for all boards that have only one
803 machine type and must be used to specify the machine type
804 number as it appears in the ARM machine registry
805 (see http://www.arm.linux.org.uk/developer/machines/).
806 Only boards that have multiple machine types supported
807 in a single configuration file and the machine type is
808 runtime discoverable, do not have to use this setting.
810 - vxWorks boot parameters:
812 bootvx constructs a valid bootline using the following
813 environments variables: bootfile, ipaddr, serverip, hostname.
814 It loads the vxWorks image pointed bootfile.
816 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
817 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
818 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
819 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
821 CONFIG_SYS_VXWORKS_ADD_PARAMS
823 Add it at the end of the bootline. E.g "u=username pw=secret"
825 Note: If a "bootargs" environment is defined, it will overwride
826 the defaults discussed just above.
828 - Cache Configuration:
829 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
830 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
831 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
833 - Cache Configuration for ARM:
834 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
836 CONFIG_SYS_PL310_BASE - Physical base address of PL310
837 controller register space
842 Define this if you want support for Amba PrimeCell PL010 UARTs.
846 Define this if you want support for Amba PrimeCell PL011 UARTs.
850 If you have Amba PrimeCell PL011 UARTs, set this variable to
851 the clock speed of the UARTs.
855 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
856 define this to a list of base addresses for each (supported)
857 port. See e.g. include/configs/versatile.h
859 CONFIG_PL011_SERIAL_RLCR
861 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
862 have separate receive and transmit line control registers. Set
863 this variable to initialize the extra register.
865 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
867 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
868 boot loader that has already initialized the UART. Define this
869 variable to flush the UART at init time.
871 CONFIG_SERIAL_HW_FLOW_CONTROL
873 Define this variable to enable hw flow control in serial driver.
874 Current user of this option is drivers/serial/nsl16550.c driver
877 Depending on board, define exactly one serial port
878 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
879 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
880 console by defining CONFIG_8xx_CONS_NONE
882 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
883 port routines must be defined elsewhere
884 (i.e. serial_init(), serial_getc(), ...)
887 Enables console device for a color framebuffer. Needs following
888 defines (cf. smiLynxEM, i8042)
889 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
891 VIDEO_HW_RECTFILL graphic chip supports
894 VIDEO_HW_BITBLT graphic chip supports
895 bit-blit (cf. smiLynxEM)
896 VIDEO_VISIBLE_COLS visible pixel columns
898 VIDEO_VISIBLE_ROWS visible pixel rows
899 VIDEO_PIXEL_SIZE bytes per pixel
900 VIDEO_DATA_FORMAT graphic data format
901 (0-5, cf. cfb_console.c)
902 VIDEO_FB_ADRS framebuffer address
903 VIDEO_KBD_INIT_FCT keyboard int fct
904 (i.e. i8042_kbd_init())
905 VIDEO_TSTC_FCT test char fct
907 VIDEO_GETC_FCT get char fct
909 CONFIG_CONSOLE_CURSOR cursor drawing on/off
910 (requires blink timer
912 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
913 CONFIG_CONSOLE_TIME display time/date info in
915 (requires CONFIG_CMD_DATE)
916 CONFIG_VIDEO_LOGO display Linux logo in
918 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
919 linux_logo.h for logo.
920 Requires CONFIG_VIDEO_LOGO
921 CONFIG_CONSOLE_EXTRA_INFO
922 additional board info beside
925 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
926 a limited number of ANSI escape sequences (cursor control,
927 erase functions and limited graphics rendition control).
929 When CONFIG_CFB_CONSOLE is defined, video console is
930 default i/o. Serial console can be forced with
931 environment 'console=serial'.
933 When CONFIG_SILENT_CONSOLE is defined, all console
934 messages (by U-Boot and Linux!) can be silenced with
935 the "silent" environment variable. See
936 doc/README.silent for more information.
938 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
940 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
944 CONFIG_BAUDRATE - in bps
945 Select one of the baudrates listed in
946 CONFIG_SYS_BAUDRATE_TABLE, see below.
947 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
949 - Console Rx buffer length
950 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
951 the maximum receive buffer length for the SMC.
952 This option is actual only for 82xx and 8xx possible.
953 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
954 must be defined, to setup the maximum idle timeout for
957 - Pre-Console Buffer:
958 Prior to the console being initialised (i.e. serial UART
959 initialised etc) all console output is silently discarded.
960 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
961 buffer any console messages prior to the console being
962 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
963 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
964 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
965 bytes are output before the console is initialised, the
966 earlier bytes are discarded.
968 'Sane' compilers will generate smaller code if
969 CONFIG_PRE_CON_BUF_SZ is a power of 2
971 - Safe printf() functions
972 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
973 the printf() functions. These are defined in
974 include/vsprintf.h and include snprintf(), vsnprintf() and
975 so on. Code size increase is approximately 300-500 bytes.
976 If this option is not given then these functions will
977 silently discard their buffer size argument - this means
978 you are not getting any overflow checking in this case.
980 - Boot Delay: CONFIG_BOOTDELAY - in seconds
981 Delay before automatically booting the default image;
982 set to -1 to disable autoboot.
983 set to -2 to autoboot with no delay and not check for abort
984 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
986 See doc/README.autoboot for these options that
987 work with CONFIG_BOOTDELAY. None are required.
988 CONFIG_BOOT_RETRY_TIME
989 CONFIG_BOOT_RETRY_MIN
990 CONFIG_AUTOBOOT_KEYED
991 CONFIG_AUTOBOOT_PROMPT
992 CONFIG_AUTOBOOT_DELAY_STR
993 CONFIG_AUTOBOOT_STOP_STR
994 CONFIG_AUTOBOOT_DELAY_STR2
995 CONFIG_AUTOBOOT_STOP_STR2
996 CONFIG_ZERO_BOOTDELAY_CHECK
997 CONFIG_RESET_TO_RETRY
1001 Only needed when CONFIG_BOOTDELAY is enabled;
1002 define a command string that is automatically executed
1003 when no character is read on the console interface
1004 within "Boot Delay" after reset.
1007 This can be used to pass arguments to the bootm
1008 command. The value of CONFIG_BOOTARGS goes into the
1009 environment value "bootargs".
1011 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1012 The value of these goes into the environment as
1013 "ramboot" and "nfsboot" respectively, and can be used
1014 as a convenience, when switching between booting from
1018 CONFIG_BOOTCOUNT_LIMIT
1019 Implements a mechanism for detecting a repeating reboot
1021 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1023 CONFIG_BOOTCOUNT_ENV
1024 If no softreset save registers are found on the hardware
1025 "bootcount" is stored in the environment. To prevent a
1026 saveenv on all reboots, the environment variable
1027 "upgrade_available" is used. If "upgrade_available" is
1028 0, "bootcount" is always 0, if "upgrade_available" is
1029 1 "bootcount" is incremented in the environment.
1030 So the Userspace Applikation must set the "upgrade_available"
1031 and "bootcount" variable to 0, if a boot was successfully.
1033 - Pre-Boot Commands:
1036 When this option is #defined, the existence of the
1037 environment variable "preboot" will be checked
1038 immediately before starting the CONFIG_BOOTDELAY
1039 countdown and/or running the auto-boot command resp.
1040 entering interactive mode.
1042 This feature is especially useful when "preboot" is
1043 automatically generated or modified. For an example
1044 see the LWMON board specific code: here "preboot" is
1045 modified when the user holds down a certain
1046 combination of keys on the (special) keyboard when
1049 - Serial Download Echo Mode:
1051 If defined to 1, all characters received during a
1052 serial download (using the "loads" command) are
1053 echoed back. This might be needed by some terminal
1054 emulations (like "cu"), but may as well just take
1055 time on others. This setting #define's the initial
1056 value of the "loads_echo" environment variable.
1058 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1059 CONFIG_KGDB_BAUDRATE
1060 Select one of the baudrates listed in
1061 CONFIG_SYS_BAUDRATE_TABLE, see below.
1063 - Monitor Functions:
1064 Monitor commands can be included or excluded
1065 from the build by using the #include files
1066 <config_cmd_all.h> and #undef'ing unwanted
1067 commands, or using <config_cmd_default.h>
1068 and augmenting with additional #define's
1069 for wanted commands.
1071 The default command configuration includes all commands
1072 except those marked below with a "*".
1074 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1075 CONFIG_CMD_ASKENV * ask for env variable
1076 CONFIG_CMD_BDI bdinfo
1077 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1078 CONFIG_CMD_BMP * BMP support
1079 CONFIG_CMD_BSP * Board specific commands
1080 CONFIG_CMD_BOOTD bootd
1081 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1082 CONFIG_CMD_CACHE * icache, dcache
1083 CONFIG_CMD_CLK * clock command support
1084 CONFIG_CMD_CONSOLE coninfo
1085 CONFIG_CMD_CRC32 * crc32
1086 CONFIG_CMD_DATE * support for RTC, date/time...
1087 CONFIG_CMD_DHCP * DHCP support
1088 CONFIG_CMD_DIAG * Diagnostics
1089 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1090 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1091 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1092 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1093 CONFIG_CMD_DTT * Digital Therm and Thermostat
1094 CONFIG_CMD_ECHO echo arguments
1095 CONFIG_CMD_EDITENV edit env variable
1096 CONFIG_CMD_EEPROM * EEPROM read/write support
1097 CONFIG_CMD_ELF * bootelf, bootvx
1098 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1099 CONFIG_CMD_ENV_FLAGS * display details about env flags
1100 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1101 CONFIG_CMD_EXPORTENV * export the environment
1102 CONFIG_CMD_EXT2 * ext2 command support
1103 CONFIG_CMD_EXT4 * ext4 command support
1104 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1105 that work for multiple fs types
1106 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1107 CONFIG_CMD_SAVEENV saveenv
1108 CONFIG_CMD_FDC * Floppy Disk Support
1109 CONFIG_CMD_FAT * FAT command support
1110 CONFIG_CMD_FLASH flinfo, erase, protect
1111 CONFIG_CMD_FPGA FPGA device initialization support
1112 CONFIG_CMD_FUSE * Device fuse support
1113 CONFIG_CMD_GETTIME * Get time since boot
1114 CONFIG_CMD_GO * the 'go' command (exec code)
1115 CONFIG_CMD_GREPENV * search environment
1116 CONFIG_CMD_HASH * calculate hash / digest
1117 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1118 CONFIG_CMD_I2C * I2C serial bus support
1119 CONFIG_CMD_IDE * IDE harddisk support
1120 CONFIG_CMD_IMI iminfo
1121 CONFIG_CMD_IMLS List all images found in NOR flash
1122 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1123 CONFIG_CMD_IMMAP * IMMR dump support
1124 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1125 CONFIG_CMD_IMPORTENV * import an environment
1126 CONFIG_CMD_INI * import data from an ini file into the env
1127 CONFIG_CMD_IRQ * irqinfo
1128 CONFIG_CMD_ITEST Integer/string test of 2 values
1129 CONFIG_CMD_JFFS2 * JFFS2 Support
1130 CONFIG_CMD_KGDB * kgdb
1131 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1132 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1134 CONFIG_CMD_LOADB loadb
1135 CONFIG_CMD_LOADS loads
1136 CONFIG_CMD_MD5SUM * print md5 message digest
1137 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1138 CONFIG_CMD_MEMINFO * Display detailed memory information
1139 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1141 CONFIG_CMD_MEMTEST * mtest
1142 CONFIG_CMD_MISC Misc functions like sleep etc
1143 CONFIG_CMD_MMC * MMC memory mapped support
1144 CONFIG_CMD_MII * MII utility commands
1145 CONFIG_CMD_MTDPARTS * MTD partition support
1146 CONFIG_CMD_NAND * NAND support
1147 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1148 CONFIG_CMD_NFS NFS support
1149 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1150 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1151 CONFIG_CMD_PCI * pciinfo
1152 CONFIG_CMD_PCMCIA * PCMCIA support
1153 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1155 CONFIG_CMD_PORTIO * Port I/O
1156 CONFIG_CMD_READ * Read raw data from partition
1157 CONFIG_CMD_REGINFO * Register dump
1158 CONFIG_CMD_RUN run command in env variable
1159 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1160 CONFIG_CMD_SAVES * save S record dump
1161 CONFIG_CMD_SCSI * SCSI Support
1162 CONFIG_CMD_SDRAM * print SDRAM configuration information
1163 (requires CONFIG_CMD_I2C)
1164 CONFIG_CMD_SETGETDCR Support for DCR Register access
1166 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1167 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1168 (requires CONFIG_CMD_MEMORY)
1169 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1170 CONFIG_CMD_SOURCE "source" command Support
1171 CONFIG_CMD_SPI * SPI serial bus support
1172 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1173 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1174 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1175 CONFIG_CMD_TIMER * access to the system tick timer
1176 CONFIG_CMD_USB * USB support
1177 CONFIG_CMD_CDP * Cisco Discover Protocol support
1178 CONFIG_CMD_MFSL * Microblaze FSL support
1179 CONFIG_CMD_XIMG Load part of Multi Image
1180 CONFIG_CMD_UUID * Generate random UUID or GUID string
1182 EXAMPLE: If you want all functions except of network
1183 support you can write:
1185 #include "config_cmd_all.h"
1186 #undef CONFIG_CMD_NET
1189 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1191 Note: Don't enable the "icache" and "dcache" commands
1192 (configuration option CONFIG_CMD_CACHE) unless you know
1193 what you (and your U-Boot users) are doing. Data
1194 cache cannot be enabled on systems like the 8xx or
1195 8260 (where accesses to the IMMR region must be
1196 uncached), and it cannot be disabled on all other
1197 systems where we (mis-) use the data cache to hold an
1198 initial stack and some data.
1201 XXX - this list needs to get updated!
1203 - Regular expression support:
1205 If this variable is defined, U-Boot is linked against
1206 the SLRE (Super Light Regular Expression) library,
1207 which adds regex support to some commands, as for
1208 example "env grep" and "setexpr".
1212 If this variable is defined, U-Boot will use a device tree
1213 to configure its devices, instead of relying on statically
1214 compiled #defines in the board file. This option is
1215 experimental and only available on a few boards. The device
1216 tree is available in the global data as gd->fdt_blob.
1218 U-Boot needs to get its device tree from somewhere. This can
1219 be done using one of the two options below:
1222 If this variable is defined, U-Boot will embed a device tree
1223 binary in its image. This device tree file should be in the
1224 board directory and called <soc>-<board>.dts. The binary file
1225 is then picked up in board_init_f() and made available through
1226 the global data structure as gd->blob.
1229 If this variable is defined, U-Boot will build a device tree
1230 binary. It will be called u-boot.dtb. Architecture-specific
1231 code will locate it at run-time. Generally this works by:
1233 cat u-boot.bin u-boot.dtb >image.bin
1235 and in fact, U-Boot does this for you, creating a file called
1236 u-boot-dtb.bin which is useful in the common case. You can
1237 still use the individual files if you need something more
1242 If this variable is defined, it enables watchdog
1243 support for the SoC. There must be support in the SoC
1244 specific code for a watchdog. For the 8xx and 8260
1245 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1246 register. When supported for a specific SoC is
1247 available, then no further board specific code should
1248 be needed to use it.
1251 When using a watchdog circuitry external to the used
1252 SoC, then define this variable and provide board
1253 specific code for the "hw_watchdog_reset" function.
1256 CONFIG_VERSION_VARIABLE
1257 If this variable is defined, an environment variable
1258 named "ver" is created by U-Boot showing the U-Boot
1259 version as printed by the "version" command.
1260 Any change to this variable will be reverted at the
1265 When CONFIG_CMD_DATE is selected, the type of the RTC
1266 has to be selected, too. Define exactly one of the
1269 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1270 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1271 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1272 CONFIG_RTC_MC146818 - use MC146818 RTC
1273 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1274 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1275 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1276 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1277 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1278 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1279 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1280 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1281 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1284 Note that if the RTC uses I2C, then the I2C interface
1285 must also be configured. See I2C Support, below.
1288 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1290 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1291 chip-ngpio pairs that tell the PCA953X driver the number of
1292 pins supported by a particular chip.
1294 Note that if the GPIO device uses I2C, then the I2C interface
1295 must also be configured. See I2C Support, below.
1298 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1299 accesses and can checksum them or write a list of them out
1300 to memory. See the 'iotrace' command for details. This is
1301 useful for testing device drivers since it can confirm that
1302 the driver behaves the same way before and after a code
1303 change. Currently this is supported on sandbox and arm. To
1304 add support for your architecture, add '#include <iotrace.h>'
1305 to the bottom of arch/<arch>/include/asm/io.h and test.
1307 Example output from the 'iotrace stats' command is below.
1308 Note that if the trace buffer is exhausted, the checksum will
1309 still continue to operate.
1312 Start: 10000000 (buffer start address)
1313 Size: 00010000 (buffer size)
1314 Offset: 00000120 (current buffer offset)
1315 Output: 10000120 (start + offset)
1316 Count: 00000018 (number of trace records)
1317 CRC32: 9526fb66 (CRC32 of all trace records)
1319 - Timestamp Support:
1321 When CONFIG_TIMESTAMP is selected, the timestamp
1322 (date and time) of an image is printed by image
1323 commands like bootm or iminfo. This option is
1324 automatically enabled when you select CONFIG_CMD_DATE .
1326 - Partition Labels (disklabels) Supported:
1327 Zero or more of the following:
1328 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1329 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1330 Intel architecture, USB sticks, etc.
1331 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1332 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1333 bootloader. Note 2TB partition limit; see
1335 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1337 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1338 CONFIG_CMD_SCSI) you must configure support for at
1339 least one non-MTD partition type as well.
1342 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1343 board configurations files but used nowhere!
1345 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1346 be performed by calling the function
1347 ide_set_reset(int reset)
1348 which has to be defined in a board specific file
1353 Set this to enable ATAPI support.
1358 Set this to enable support for disks larger than 137GB
1359 Also look at CONFIG_SYS_64BIT_LBA.
1360 Whithout these , LBA48 support uses 32bit variables and will 'only'
1361 support disks up to 2.1TB.
1363 CONFIG_SYS_64BIT_LBA:
1364 When enabled, makes the IDE subsystem use 64bit sector addresses.
1368 At the moment only there is only support for the
1369 SYM53C8XX SCSI controller; define
1370 CONFIG_SCSI_SYM53C8XX to enable it.
1372 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1373 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1374 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1375 maximum numbers of LUNs, SCSI ID's and target
1377 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1379 The environment variable 'scsidevs' is set to the number of
1380 SCSI devices found during the last scan.
1382 - NETWORK Support (PCI):
1384 Support for Intel 8254x/8257x gigabit chips.
1387 Utility code for direct access to the SPI bus on Intel 8257x.
1388 This does not do anything useful unless you set at least one
1389 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1391 CONFIG_E1000_SPI_GENERIC
1392 Allow generic access to the SPI bus on the Intel 8257x, for
1393 example with the "sspi" command.
1396 Management command for E1000 devices. When used on devices
1397 with SPI support you can reprogram the EEPROM from U-Boot.
1399 CONFIG_E1000_FALLBACK_MAC
1400 default MAC for empty EEPROM after production.
1403 Support for Intel 82557/82559/82559ER chips.
1404 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1405 write routine for first time initialisation.
1408 Support for Digital 2114x chips.
1409 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1410 modem chip initialisation (KS8761/QS6611).
1413 Support for National dp83815 chips.
1416 Support for National dp8382[01] gigabit chips.
1418 - NETWORK Support (other):
1420 CONFIG_DRIVER_AT91EMAC
1421 Support for AT91RM9200 EMAC.
1424 Define this to use reduced MII inteface
1426 CONFIG_DRIVER_AT91EMAC_QUIET
1427 If this defined, the driver is quiet.
1428 The driver doen't show link status messages.
1430 CONFIG_CALXEDA_XGMAC
1431 Support for the Calxeda XGMAC device
1434 Support for SMSC's LAN91C96 chips.
1436 CONFIG_LAN91C96_BASE
1437 Define this to hold the physical address
1438 of the LAN91C96's I/O space
1440 CONFIG_LAN91C96_USE_32_BIT
1441 Define this to enable 32 bit addressing
1444 Support for SMSC's LAN91C111 chip
1446 CONFIG_SMC91111_BASE
1447 Define this to hold the physical address
1448 of the device (I/O space)
1450 CONFIG_SMC_USE_32_BIT
1451 Define this if data bus is 32 bits
1453 CONFIG_SMC_USE_IOFUNCS
1454 Define this to use i/o functions instead of macros
1455 (some hardware wont work with macros)
1457 CONFIG_DRIVER_TI_EMAC
1458 Support for davinci emac
1460 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1461 Define this if you have more then 3 PHYs.
1464 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1466 CONFIG_FTGMAC100_EGIGA
1467 Define this to use GE link update with gigabit PHY.
1468 Define this if FTGMAC100 is connected to gigabit PHY.
1469 If your system has 10/100 PHY only, it might not occur
1470 wrong behavior. Because PHY usually return timeout or
1471 useless data when polling gigabit status and gigabit
1472 control registers. This behavior won't affect the
1473 correctnessof 10/100 link speed update.
1476 Support for SMSC's LAN911x and LAN921x chips
1479 Define this to hold the physical address
1480 of the device (I/O space)
1482 CONFIG_SMC911X_32_BIT
1483 Define this if data bus is 32 bits
1485 CONFIG_SMC911X_16_BIT
1486 Define this if data bus is 16 bits. If your processor
1487 automatically converts one 32 bit word to two 16 bit
1488 words you may also try CONFIG_SMC911X_32_BIT.
1491 Support for Renesas on-chip Ethernet controller
1493 CONFIG_SH_ETHER_USE_PORT
1494 Define the number of ports to be used
1496 CONFIG_SH_ETHER_PHY_ADDR
1497 Define the ETH PHY's address
1499 CONFIG_SH_ETHER_CACHE_WRITEBACK
1500 If this option is set, the driver enables cache flush.
1504 Support for PWM modul on the imx6.
1508 Support TPM devices.
1511 Support for i2c bus TPM devices. Only one device
1512 per system is supported at this time.
1514 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1515 Define the the i2c bus number for the TPM device
1517 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1518 Define the TPM's address on the i2c bus
1520 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1521 Define the burst count bytes upper limit
1523 CONFIG_TPM_ATMEL_TWI
1524 Support for Atmel TWI TPM device. Requires I2C support.
1527 Support for generic parallel port TPM devices. Only one device
1528 per system is supported at this time.
1530 CONFIG_TPM_TIS_BASE_ADDRESS
1531 Base address where the generic TPM device is mapped
1532 to. Contemporary x86 systems usually map it at
1536 Add tpm monitor functions.
1537 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1538 provides monitor access to authorized functions.
1541 Define this to enable the TPM support library which provides
1542 functional interfaces to some TPM commands.
1543 Requires support for a TPM device.
1545 CONFIG_TPM_AUTH_SESSIONS
1546 Define this to enable authorized functions in the TPM library.
1547 Requires CONFIG_TPM and CONFIG_SHA1.
1550 At the moment only the UHCI host controller is
1551 supported (PIP405, MIP405, MPC5200); define
1552 CONFIG_USB_UHCI to enable it.
1553 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1554 and define CONFIG_USB_STORAGE to enable the USB
1557 Supported are USB Keyboards and USB Floppy drives
1559 MPC5200 USB requires additional defines:
1561 for 528 MHz Clock: 0x0001bbbb
1565 for differential drivers: 0x00001000
1566 for single ended drivers: 0x00005000
1567 for differential drivers on PSC3: 0x00000100
1568 for single ended drivers on PSC3: 0x00004100
1569 CONFIG_SYS_USB_EVENT_POLL
1570 May be defined to allow interrupt polling
1571 instead of using asynchronous interrupts
1573 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1574 txfilltuning field in the EHCI controller on reset.
1576 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1577 HW module registers.
1580 Define the below if you wish to use the USB console.
1581 Once firmware is rebuilt from a serial console issue the
1582 command "setenv stdin usbtty; setenv stdout usbtty" and
1583 attach your USB cable. The Unix command "dmesg" should print
1584 it has found a new device. The environment variable usbtty
1585 can be set to gserial or cdc_acm to enable your device to
1586 appear to a USB host as a Linux gserial device or a
1587 Common Device Class Abstract Control Model serial device.
1588 If you select usbtty = gserial you should be able to enumerate
1590 # modprobe usbserial vendor=0xVendorID product=0xProductID
1591 else if using cdc_acm, simply setting the environment
1592 variable usbtty to be cdc_acm should suffice. The following
1593 might be defined in YourBoardName.h
1596 Define this to build a UDC device
1599 Define this to have a tty type of device available to
1600 talk to the UDC device
1603 Define this to enable the high speed support for usb
1604 device and usbtty. If this feature is enabled, a routine
1605 int is_usbd_high_speed(void)
1606 also needs to be defined by the driver to dynamically poll
1607 whether the enumeration has succeded at high speed or full
1610 CONFIG_SYS_CONSOLE_IS_IN_ENV
1611 Define this if you want stdin, stdout &/or stderr to
1615 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1616 Derive USB clock from external clock "blah"
1617 - CONFIG_SYS_USB_EXTC_CLK 0x02
1619 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1620 Derive USB clock from brgclk
1621 - CONFIG_SYS_USB_BRG_CLK 0x04
1623 If you have a USB-IF assigned VendorID then you may wish to
1624 define your own vendor specific values either in BoardName.h
1625 or directly in usbd_vendor_info.h. If you don't define
1626 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1627 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1628 should pretend to be a Linux device to it's target host.
1630 CONFIG_USBD_MANUFACTURER
1631 Define this string as the name of your company for
1632 - CONFIG_USBD_MANUFACTURER "my company"
1634 CONFIG_USBD_PRODUCT_NAME
1635 Define this string as the name of your product
1636 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1638 CONFIG_USBD_VENDORID
1639 Define this as your assigned Vendor ID from the USB
1640 Implementors Forum. This *must* be a genuine Vendor ID
1641 to avoid polluting the USB namespace.
1642 - CONFIG_USBD_VENDORID 0xFFFF
1644 CONFIG_USBD_PRODUCTID
1645 Define this as the unique Product ID
1647 - CONFIG_USBD_PRODUCTID 0xFFFF
1649 - ULPI Layer Support:
1650 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1651 the generic ULPI layer. The generic layer accesses the ULPI PHY
1652 via the platform viewport, so you need both the genric layer and
1653 the viewport enabled. Currently only Chipidea/ARC based
1654 viewport is supported.
1655 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1656 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1657 If your ULPI phy needs a different reference clock than the
1658 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1659 the appropriate value in Hz.
1662 The MMC controller on the Intel PXA is supported. To
1663 enable this define CONFIG_MMC. The MMC can be
1664 accessed from the boot prompt by mapping the device
1665 to physical memory similar to flash. Command line is
1666 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1667 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1670 Support for Renesas on-chip MMCIF controller
1672 CONFIG_SH_MMCIF_ADDR
1673 Define the base address of MMCIF registers
1676 Define the clock frequency for MMCIF
1679 Enable the generic MMC driver
1681 CONFIG_SUPPORT_EMMC_BOOT
1682 Enable some additional features of the eMMC boot partitions.
1684 CONFIG_SUPPORT_EMMC_RPMB
1685 Enable the commands for reading, writing and programming the
1686 key for the Replay Protection Memory Block partition in eMMC.
1688 - USB Device Firmware Update (DFU) class support:
1690 This enables the USB portion of the DFU USB class
1693 This enables the command "dfu" which is used to have
1694 U-Boot create a DFU class device via USB. This command
1695 requires that the "dfu_alt_info" environment variable be
1696 set and define the alt settings to expose to the host.
1699 This enables support for exposing (e)MMC devices via DFU.
1702 This enables support for exposing NAND devices via DFU.
1705 This enables support for exposing RAM via DFU.
1706 Note: DFU spec refer to non-volatile memory usage, but
1707 allow usages beyond the scope of spec - here RAM usage,
1708 one that would help mostly the developer.
1710 CONFIG_SYS_DFU_DATA_BUF_SIZE
1711 Dfu transfer uses a buffer before writing data to the
1712 raw storage device. Make the size (in bytes) of this buffer
1713 configurable. The size of this buffer is also configurable
1714 through the "dfu_bufsiz" environment variable.
1716 CONFIG_SYS_DFU_MAX_FILE_SIZE
1717 When updating files rather than the raw storage device,
1718 we use a static buffer to copy the file into and then write
1719 the buffer once we've been given the whole file. Define
1720 this to the maximum filesize (in bytes) for the buffer.
1721 Default is 4 MiB if undefined.
1723 DFU_DEFAULT_POLL_TIMEOUT
1724 Poll timeout [ms], is the timeout a device can send to the
1725 host. The host must wait for this timeout before sending
1726 a subsequent DFU_GET_STATUS request to the device.
1728 DFU_MANIFEST_POLL_TIMEOUT
1729 Poll timeout [ms], which the device sends to the host when
1730 entering dfuMANIFEST state. Host waits this timeout, before
1731 sending again an USB request to the device.
1733 - USB Device Android Fastboot support:
1735 This enables the command "fastboot" which enables the Android
1736 fastboot mode for the platform's USB device. Fastboot is a USB
1737 protocol for downloading images, flashing and device control
1738 used on Android devices.
1739 See doc/README.android-fastboot for more information.
1741 CONFIG_ANDROID_BOOT_IMAGE
1742 This enables support for booting images which use the Android
1743 image format header.
1745 CONFIG_USB_FASTBOOT_BUF_ADDR
1746 The fastboot protocol requires a large memory buffer for
1747 downloads. Define this to the starting RAM address to use for
1750 CONFIG_USB_FASTBOOT_BUF_SIZE
1751 The fastboot protocol requires a large memory buffer for
1752 downloads. This buffer should be as large as possible for a
1753 platform. Define this to the size available RAM for fastboot.
1755 CONFIG_FASTBOOT_FLASH
1756 The fastboot protocol includes a "flash" command for writing
1757 the downloaded image to a non-volatile storage device. Define
1758 this to enable the "fastboot flash" command.
1760 CONFIG_FASTBOOT_FLASH_MMC_DEV
1761 The fastboot "flash" command requires additional information
1762 regarding the non-volatile storage device. Define this to
1763 the eMMC device that fastboot should use to store the image.
1765 - Journaling Flash filesystem support:
1766 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1767 CONFIG_JFFS2_NAND_DEV
1768 Define these for a default partition on a NAND device
1770 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1771 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1772 Define these for a default partition on a NOR device
1774 CONFIG_SYS_JFFS_CUSTOM_PART
1775 Define this to create an own partition. You have to provide a
1776 function struct part_info* jffs2_part_info(int part_num)
1778 If you define only one JFFS2 partition you may also want to
1779 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1780 to disable the command chpart. This is the default when you
1781 have not defined a custom partition
1783 - FAT(File Allocation Table) filesystem write function support:
1786 Define this to enable support for saving memory data as a
1787 file in FAT formatted partition.
1789 This will also enable the command "fatwrite" enabling the
1790 user to write files to FAT.
1792 CBFS (Coreboot Filesystem) support
1795 Define this to enable support for reading from a Coreboot
1796 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1799 - FAT(File Allocation Table) filesystem cluster size:
1800 CONFIG_FS_FAT_MAX_CLUSTSIZE
1802 Define the max cluster size for fat operations else
1803 a default value of 65536 will be defined.
1808 Define this to enable standard (PC-Style) keyboard
1812 Standard PC keyboard driver with US (is default) and
1813 GERMAN key layout (switch via environment 'keymap=de') support.
1814 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1815 for cfb_console. Supports cursor blinking.
1818 Enables a Chrome OS keyboard using the CROS_EC interface.
1819 This uses CROS_EC to communicate with a second microcontroller
1820 which provides key scans on request.
1825 Define this to enable video support (for output to
1828 CONFIG_VIDEO_CT69000
1830 Enable Chips & Technologies 69000 Video chip
1832 CONFIG_VIDEO_SMI_LYNXEM
1833 Enable Silicon Motion SMI 712/710/810 Video chip. The
1834 video output is selected via environment 'videoout'
1835 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1838 For the CT69000 and SMI_LYNXEM drivers, videomode is
1839 selected via environment 'videomode'. Two different ways
1841 - "videomode=num" 'num' is a standard LiLo mode numbers.
1842 Following standard modes are supported (* is default):
1844 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1845 -------------+---------------------------------------------
1846 8 bits | 0x301* 0x303 0x305 0x161 0x307
1847 15 bits | 0x310 0x313 0x316 0x162 0x319
1848 16 bits | 0x311 0x314 0x317 0x163 0x31A
1849 24 bits | 0x312 0x315 0x318 ? 0x31B
1850 -------------+---------------------------------------------
1851 (i.e. setenv videomode 317; saveenv; reset;)
1853 - "videomode=bootargs" all the video parameters are parsed
1854 from the bootargs. (See drivers/video/videomodes.c)
1857 CONFIG_VIDEO_SED13806
1858 Enable Epson SED13806 driver. This driver supports 8bpp
1859 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1860 or CONFIG_VIDEO_SED13806_16BPP
1863 Enable the Freescale DIU video driver. Reference boards for
1864 SOCs that have a DIU should define this macro to enable DIU
1865 support, and should also define these other macros:
1871 CONFIG_VIDEO_SW_CURSOR
1872 CONFIG_VGA_AS_SINGLE_DEVICE
1874 CONFIG_VIDEO_BMP_LOGO
1876 The DIU driver will look for the 'video-mode' environment
1877 variable, and if defined, enable the DIU as a console during
1878 boot. See the documentation file README.video for a
1879 description of this variable.
1883 Enable the VGA video / BIOS for x86. The alternative if you
1884 are using coreboot is to use the coreboot frame buffer
1891 Define this to enable a custom keyboard support.
1892 This simply calls drv_keyboard_init() which must be
1893 defined in your board-specific files.
1894 The only board using this so far is RBC823.
1896 - LCD Support: CONFIG_LCD
1898 Define this to enable LCD support (for output to LCD
1899 display); also select one of the supported displays
1900 by defining one of these:
1904 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1906 CONFIG_NEC_NL6448AC33:
1908 NEC NL6448AC33-18. Active, color, single scan.
1910 CONFIG_NEC_NL6448BC20
1912 NEC NL6448BC20-08. 6.5", 640x480.
1913 Active, color, single scan.
1915 CONFIG_NEC_NL6448BC33_54
1917 NEC NL6448BC33-54. 10.4", 640x480.
1918 Active, color, single scan.
1922 Sharp 320x240. Active, color, single scan.
1923 It isn't 16x9, and I am not sure what it is.
1925 CONFIG_SHARP_LQ64D341
1927 Sharp LQ64D341 display, 640x480.
1928 Active, color, single scan.
1932 HLD1045 display, 640x480.
1933 Active, color, single scan.
1937 Optrex CBL50840-2 NF-FW 99 22 M5
1939 Hitachi LMG6912RPFC-00T
1943 320x240. Black & white.
1945 Normally display is black on white background; define
1946 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1948 CONFIG_LCD_ALIGNMENT
1950 Normally the LCD is page-aligned (tyically 4KB). If this is
1951 defined then the LCD will be aligned to this value instead.
1952 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1953 here, since it is cheaper to change data cache settings on
1954 a per-section basis.
1956 CONFIG_CONSOLE_SCROLL_LINES
1958 When the console need to be scrolled, this is the number of
1959 lines to scroll by. It defaults to 1. Increasing this makes
1960 the console jump but can help speed up operation when scrolling
1965 Support drawing of RLE8-compressed bitmaps on the LCD.
1969 Enables an 'i2c edid' command which can read EDID
1970 information over I2C from an attached LCD display.
1972 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1974 If this option is set, the environment is checked for
1975 a variable "splashimage". If found, the usual display
1976 of logo, copyright and system information on the LCD
1977 is suppressed and the BMP image at the address
1978 specified in "splashimage" is loaded instead. The
1979 console is redirected to the "nulldev", too. This
1980 allows for a "silent" boot where a splash screen is
1981 loaded very quickly after power-on.
1983 CONFIG_SPLASHIMAGE_GUARD
1985 If this option is set, then U-Boot will prevent the environment
1986 variable "splashimage" from being set to a problematic address
1987 (see README.displaying-bmps).
1988 This option is useful for targets where, due to alignment
1989 restrictions, an improperly aligned BMP image will cause a data
1990 abort. If you think you will not have problems with unaligned
1991 accesses (for example because your toolchain prevents them)
1992 there is no need to set this option.
1994 CONFIG_SPLASH_SCREEN_ALIGN
1996 If this option is set the splash image can be freely positioned
1997 on the screen. Environment variable "splashpos" specifies the
1998 position as "x,y". If a positive number is given it is used as
1999 number of pixel from left/top. If a negative number is given it
2000 is used as number of pixel from right/bottom. You can also
2001 specify 'm' for centering the image.
2004 setenv splashpos m,m
2005 => image at center of screen
2007 setenv splashpos 30,20
2008 => image at x = 30 and y = 20
2010 setenv splashpos -10,m
2011 => vertically centered image
2012 at x = dspWidth - bmpWidth - 9
2014 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2016 If this option is set, additionally to standard BMP
2017 images, gzipped BMP images can be displayed via the
2018 splashscreen support or the bmp command.
2020 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2022 If this option is set, 8-bit RLE compressed BMP images
2023 can be displayed via the splashscreen support or the
2026 - Do compresssing for memory range:
2029 If this option is set, it would use zlib deflate method
2030 to compress the specified memory at its best effort.
2032 - Compression support:
2035 Enabled by default to support gzip compressed images.
2039 If this option is set, support for bzip2 compressed
2040 images is included. If not, only uncompressed and gzip
2041 compressed images are supported.
2043 NOTE: the bzip2 algorithm requires a lot of RAM, so
2044 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2049 If this option is set, support for lzma compressed
2052 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2053 requires an amount of dynamic memory that is given by the
2056 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2058 Where lc and lp stand for, respectively, Literal context bits
2059 and Literal pos bits.
2061 This value is upper-bounded by 14MB in the worst case. Anyway,
2062 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2063 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2064 a very small buffer.
2066 Use the lzmainfo tool to determinate the lc and lp values and
2067 then calculate the amount of needed dynamic memory (ensuring
2068 the appropriate CONFIG_SYS_MALLOC_LEN value).
2072 If this option is set, support for LZO compressed images
2078 The address of PHY on MII bus.
2080 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2082 The clock frequency of the MII bus
2086 If this option is set, support for speed/duplex
2087 detection of gigabit PHY is included.
2089 CONFIG_PHY_RESET_DELAY
2091 Some PHY like Intel LXT971A need extra delay after
2092 reset before any MII register access is possible.
2093 For such PHY, set this option to the usec delay
2094 required. (minimum 300usec for LXT971A)
2096 CONFIG_PHY_CMD_DELAY (ppc4xx)
2098 Some PHY like Intel LXT971A need extra delay after
2099 command issued before MII status register can be read
2109 Define a default value for Ethernet address to use
2110 for the respective Ethernet interface, in case this
2111 is not determined automatically.
2116 Define a default value for the IP address to use for
2117 the default Ethernet interface, in case this is not
2118 determined through e.g. bootp.
2119 (Environment variable "ipaddr")
2121 - Server IP address:
2124 Defines a default value for the IP address of a TFTP
2125 server to contact when using the "tftboot" command.
2126 (Environment variable "serverip")
2128 CONFIG_KEEP_SERVERADDR
2130 Keeps the server's MAC address, in the env 'serveraddr'
2131 for passing to bootargs (like Linux's netconsole option)
2133 - Gateway IP address:
2136 Defines a default value for the IP address of the
2137 default router where packets to other networks are
2139 (Environment variable "gatewayip")
2144 Defines a default value for the subnet mask (or
2145 routing prefix) which is used to determine if an IP
2146 address belongs to the local subnet or needs to be
2147 forwarded through a router.
2148 (Environment variable "netmask")
2150 - Multicast TFTP Mode:
2153 Defines whether you want to support multicast TFTP as per
2154 rfc-2090; for example to work with atftp. Lets lots of targets
2155 tftp down the same boot image concurrently. Note: the Ethernet
2156 driver in use must provide a function: mcast() to join/leave a
2159 - BOOTP Recovery Mode:
2160 CONFIG_BOOTP_RANDOM_DELAY
2162 If you have many targets in a network that try to
2163 boot using BOOTP, you may want to avoid that all
2164 systems send out BOOTP requests at precisely the same
2165 moment (which would happen for instance at recovery
2166 from a power failure, when all systems will try to
2167 boot, thus flooding the BOOTP server. Defining
2168 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2169 inserted before sending out BOOTP requests. The
2170 following delays are inserted then:
2172 1st BOOTP request: delay 0 ... 1 sec
2173 2nd BOOTP request: delay 0 ... 2 sec
2174 3rd BOOTP request: delay 0 ... 4 sec
2176 BOOTP requests: delay 0 ... 8 sec
2178 CONFIG_BOOTP_ID_CACHE_SIZE
2180 BOOTP packets are uniquely identified using a 32-bit ID. The
2181 server will copy the ID from client requests to responses and
2182 U-Boot will use this to determine if it is the destination of
2183 an incoming response. Some servers will check that addresses
2184 aren't in use before handing them out (usually using an ARP
2185 ping) and therefore take up to a few hundred milliseconds to
2186 respond. Network congestion may also influence the time it
2187 takes for a response to make it back to the client. If that
2188 time is too long, U-Boot will retransmit requests. In order
2189 to allow earlier responses to still be accepted after these
2190 retransmissions, U-Boot's BOOTP client keeps a small cache of
2191 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2192 cache. The default is to keep IDs for up to four outstanding
2193 requests. Increasing this will allow U-Boot to accept offers
2194 from a BOOTP client in networks with unusually high latency.
2196 - DHCP Advanced Options:
2197 You can fine tune the DHCP functionality by defining
2198 CONFIG_BOOTP_* symbols:
2200 CONFIG_BOOTP_SUBNETMASK
2201 CONFIG_BOOTP_GATEWAY
2202 CONFIG_BOOTP_HOSTNAME
2203 CONFIG_BOOTP_NISDOMAIN
2204 CONFIG_BOOTP_BOOTPATH
2205 CONFIG_BOOTP_BOOTFILESIZE
2208 CONFIG_BOOTP_SEND_HOSTNAME
2209 CONFIG_BOOTP_NTPSERVER
2210 CONFIG_BOOTP_TIMEOFFSET
2211 CONFIG_BOOTP_VENDOREX
2212 CONFIG_BOOTP_MAY_FAIL
2214 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2215 environment variable, not the BOOTP server.
2217 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2218 after the configured retry count, the call will fail
2219 instead of starting over. This can be used to fail over
2220 to Link-local IP address configuration if the DHCP server
2223 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2224 serverip from a DHCP server, it is possible that more
2225 than one DNS serverip is offered to the client.
2226 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2227 serverip will be stored in the additional environment
2228 variable "dnsip2". The first DNS serverip is always
2229 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2232 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2233 to do a dynamic update of a DNS server. To do this, they
2234 need the hostname of the DHCP requester.
2235 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2236 of the "hostname" environment variable is passed as
2237 option 12 to the DHCP server.
2239 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2241 A 32bit value in microseconds for a delay between
2242 receiving a "DHCP Offer" and sending the "DHCP Request".
2243 This fixes a problem with certain DHCP servers that don't
2244 respond 100% of the time to a "DHCP request". E.g. On an
2245 AT91RM9200 processor running at 180MHz, this delay needed
2246 to be *at least* 15,000 usec before a Windows Server 2003
2247 DHCP server would reply 100% of the time. I recommend at
2248 least 50,000 usec to be safe. The alternative is to hope
2249 that one of the retries will be successful but note that
2250 the DHCP timeout and retry process takes a longer than
2253 - Link-local IP address negotiation:
2254 Negotiate with other link-local clients on the local network
2255 for an address that doesn't require explicit configuration.
2256 This is especially useful if a DHCP server cannot be guaranteed
2257 to exist in all environments that the device must operate.
2259 See doc/README.link-local for more information.
2262 CONFIG_CDP_DEVICE_ID
2264 The device id used in CDP trigger frames.
2266 CONFIG_CDP_DEVICE_ID_PREFIX
2268 A two character string which is prefixed to the MAC address
2273 A printf format string which contains the ascii name of
2274 the port. Normally is set to "eth%d" which sets
2275 eth0 for the first Ethernet, eth1 for the second etc.
2277 CONFIG_CDP_CAPABILITIES
2279 A 32bit integer which indicates the device capabilities;
2280 0x00000010 for a normal host which does not forwards.
2284 An ascii string containing the version of the software.
2288 An ascii string containing the name of the platform.
2292 A 32bit integer sent on the trigger.
2294 CONFIG_CDP_POWER_CONSUMPTION
2296 A 16bit integer containing the power consumption of the
2297 device in .1 of milliwatts.
2299 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2301 A byte containing the id of the VLAN.
2303 - Status LED: CONFIG_STATUS_LED
2305 Several configurations allow to display the current
2306 status using a LED. For instance, the LED will blink
2307 fast while running U-Boot code, stop blinking as
2308 soon as a reply to a BOOTP request was received, and
2309 start blinking slow once the Linux kernel is running
2310 (supported by a status LED driver in the Linux
2311 kernel). Defining CONFIG_STATUS_LED enables this
2317 The status LED can be connected to a GPIO pin.
2318 In such cases, the gpio_led driver can be used as a
2319 status LED backend implementation. Define CONFIG_GPIO_LED
2320 to include the gpio_led driver in the U-Boot binary.
2322 CONFIG_GPIO_LED_INVERTED_TABLE
2323 Some GPIO connected LEDs may have inverted polarity in which
2324 case the GPIO high value corresponds to LED off state and
2325 GPIO low value corresponds to LED on state.
2326 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2327 with a list of GPIO LEDs that have inverted polarity.
2329 - CAN Support: CONFIG_CAN_DRIVER
2331 Defining CONFIG_CAN_DRIVER enables CAN driver support
2332 on those systems that support this (optional)
2333 feature, like the TQM8xxL modules.
2335 - I2C Support: CONFIG_SYS_I2C
2337 This enable the NEW i2c subsystem, and will allow you to use
2338 i2c commands at the u-boot command line (as long as you set
2339 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2340 based realtime clock chips or other i2c devices. See
2341 common/cmd_i2c.c for a description of the command line
2344 ported i2c driver to the new framework:
2345 - drivers/i2c/soft_i2c.c:
2346 - activate first bus with CONFIG_SYS_I2C_SOFT define
2347 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2348 for defining speed and slave address
2349 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2350 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2351 for defining speed and slave address
2352 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2353 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2354 for defining speed and slave address
2355 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2356 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2357 for defining speed and slave address
2359 - drivers/i2c/fsl_i2c.c:
2360 - activate i2c driver with CONFIG_SYS_I2C_FSL
2361 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2362 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2363 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2365 - If your board supports a second fsl i2c bus, define
2366 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2367 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2368 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2371 - drivers/i2c/tegra_i2c.c:
2372 - activate this driver with CONFIG_SYS_I2C_TEGRA
2373 - This driver adds 4 i2c buses with a fix speed from
2374 100000 and the slave addr 0!
2376 - drivers/i2c/ppc4xx_i2c.c
2377 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2378 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2379 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2381 - drivers/i2c/i2c_mxc.c
2382 - activate this driver with CONFIG_SYS_I2C_MXC
2383 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2384 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2385 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2386 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2387 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2388 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2389 If thoses defines are not set, default value is 100000
2390 for speed, and 0 for slave.
2392 - drivers/i2c/rcar_i2c.c:
2393 - activate this driver with CONFIG_SYS_I2C_RCAR
2394 - This driver adds 4 i2c buses
2396 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2397 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2398 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2399 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2400 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2401 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2402 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2403 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2404 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2406 - drivers/i2c/sh_i2c.c:
2407 - activate this driver with CONFIG_SYS_I2C_SH
2408 - This driver adds from 2 to 5 i2c buses
2410 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2411 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2412 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2413 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2414 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2415 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2416 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2417 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2418 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2419 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2420 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2421 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2422 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2424 - drivers/i2c/omap24xx_i2c.c
2425 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2426 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2427 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2428 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2429 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2430 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2431 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2432 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2433 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2434 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2435 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2437 - drivers/i2c/zynq_i2c.c
2438 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2439 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2440 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2442 - drivers/i2c/s3c24x0_i2c.c:
2443 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2444 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2445 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2446 with a fix speed from 100000 and the slave addr 0!
2448 - drivers/i2c/ihs_i2c.c
2449 - activate this driver with CONFIG_SYS_I2C_IHS
2450 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2451 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2452 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2453 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2454 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2455 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2456 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2457 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2458 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2459 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2460 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2461 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2465 CONFIG_SYS_NUM_I2C_BUSES
2466 Hold the number of i2c busses you want to use. If you
2467 don't use/have i2c muxes on your i2c bus, this
2468 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2471 CONFIG_SYS_I2C_DIRECT_BUS
2472 define this, if you don't use i2c muxes on your hardware.
2473 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2476 CONFIG_SYS_I2C_MAX_HOPS
2477 define how many muxes are maximal consecutively connected
2478 on one i2c bus. If you not use i2c muxes, omit this
2481 CONFIG_SYS_I2C_BUSES
2482 hold a list of busses you want to use, only used if
2483 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2484 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2485 CONFIG_SYS_NUM_I2C_BUSES = 9:
2487 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2488 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2489 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2490 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2491 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2492 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2493 {1, {I2C_NULL_HOP}}, \
2494 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2495 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2499 bus 0 on adapter 0 without a mux
2500 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2501 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2502 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2503 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2504 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2505 bus 6 on adapter 1 without a mux
2506 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2507 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2509 If you do not have i2c muxes on your board, omit this define.
2511 - Legacy I2C Support: CONFIG_HARD_I2C
2513 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2514 provides the following compelling advantages:
2516 - more than one i2c adapter is usable
2517 - approved multibus support
2518 - better i2c mux support
2520 ** Please consider updating your I2C driver now. **
2522 These enable legacy I2C serial bus commands. Defining
2523 CONFIG_HARD_I2C will include the appropriate I2C driver
2524 for the selected CPU.
2526 This will allow you to use i2c commands at the u-boot
2527 command line (as long as you set CONFIG_CMD_I2C in
2528 CONFIG_COMMANDS) and communicate with i2c based realtime
2529 clock chips. See common/cmd_i2c.c for a description of the
2530 command line interface.
2532 CONFIG_HARD_I2C selects a hardware I2C controller.
2534 There are several other quantities that must also be
2535 defined when you define CONFIG_HARD_I2C.
2537 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2538 to be the frequency (in Hz) at which you wish your i2c bus
2539 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2540 the CPU's i2c node address).
2542 Now, the u-boot i2c code for the mpc8xx
2543 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2544 and so its address should therefore be cleared to 0 (See,
2545 eg, MPC823e User's Manual p.16-473). So, set
2546 CONFIG_SYS_I2C_SLAVE to 0.
2548 CONFIG_SYS_I2C_INIT_MPC5XXX
2550 When a board is reset during an i2c bus transfer
2551 chips might think that the current transfer is still
2552 in progress. Reset the slave devices by sending start
2553 commands until the slave device responds.
2555 That's all that's required for CONFIG_HARD_I2C.
2557 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2558 then the following macros need to be defined (examples are
2559 from include/configs/lwmon.h):
2563 (Optional). Any commands necessary to enable the I2C
2564 controller or configure ports.
2566 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2570 (Only for MPC8260 CPU). The I/O port to use (the code
2571 assumes both bits are on the same port). Valid values
2572 are 0..3 for ports A..D.
2576 The code necessary to make the I2C data line active
2577 (driven). If the data line is open collector, this
2580 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2584 The code necessary to make the I2C data line tri-stated
2585 (inactive). If the data line is open collector, this
2588 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2592 Code that returns true if the I2C data line is high,
2595 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2599 If <bit> is true, sets the I2C data line high. If it
2600 is false, it clears it (low).
2602 eg: #define I2C_SDA(bit) \
2603 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2604 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2608 If <bit> is true, sets the I2C clock line high. If it
2609 is false, it clears it (low).
2611 eg: #define I2C_SCL(bit) \
2612 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2613 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2617 This delay is invoked four times per clock cycle so this
2618 controls the rate of data transfer. The data rate thus
2619 is 1 / (I2C_DELAY * 4). Often defined to be something
2622 #define I2C_DELAY udelay(2)
2624 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2626 If your arch supports the generic GPIO framework (asm/gpio.h),
2627 then you may alternatively define the two GPIOs that are to be
2628 used as SCL / SDA. Any of the previous I2C_xxx macros will
2629 have GPIO-based defaults assigned to them as appropriate.
2631 You should define these to the GPIO value as given directly to
2632 the generic GPIO functions.
2634 CONFIG_SYS_I2C_INIT_BOARD
2636 When a board is reset during an i2c bus transfer
2637 chips might think that the current transfer is still
2638 in progress. On some boards it is possible to access
2639 the i2c SCLK line directly, either by using the
2640 processor pin as a GPIO or by having a second pin
2641 connected to the bus. If this option is defined a
2642 custom i2c_init_board() routine in boards/xxx/board.c
2643 is run early in the boot sequence.
2645 CONFIG_SYS_I2C_BOARD_LATE_INIT
2647 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2648 defined a custom i2c_board_late_init() routine in
2649 boards/xxx/board.c is run AFTER the operations in i2c_init()
2650 is completed. This callpoint can be used to unreset i2c bus
2651 using CPU i2c controller register accesses for CPUs whose i2c
2652 controller provide such a method. It is called at the end of
2653 i2c_init() to allow i2c_init operations to setup the i2c bus
2654 controller on the CPU (e.g. setting bus speed & slave address).
2656 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2658 This option enables configuration of bi_iic_fast[] flags
2659 in u-boot bd_info structure based on u-boot environment
2660 variable "i2cfast". (see also i2cfast)
2662 CONFIG_I2C_MULTI_BUS
2664 This option allows the use of multiple I2C buses, each of which
2665 must have a controller. At any point in time, only one bus is
2666 active. To switch to a different bus, use the 'i2c dev' command.
2667 Note that bus numbering is zero-based.
2669 CONFIG_SYS_I2C_NOPROBES
2671 This option specifies a list of I2C devices that will be skipped
2672 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2673 is set, specify a list of bus-device pairs. Otherwise, specify
2674 a 1D array of device addresses
2677 #undef CONFIG_I2C_MULTI_BUS
2678 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2680 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2682 #define CONFIG_I2C_MULTI_BUS
2683 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2685 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2687 CONFIG_SYS_SPD_BUS_NUM
2689 If defined, then this indicates the I2C bus number for DDR SPD.
2690 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2692 CONFIG_SYS_RTC_BUS_NUM
2694 If defined, then this indicates the I2C bus number for the RTC.
2695 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2697 CONFIG_SYS_DTT_BUS_NUM
2699 If defined, then this indicates the I2C bus number for the DTT.
2700 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2702 CONFIG_SYS_I2C_DTT_ADDR:
2704 If defined, specifies the I2C address of the DTT device.
2705 If not defined, then U-Boot uses predefined value for
2706 specified DTT device.
2708 CONFIG_SOFT_I2C_READ_REPEATED_START
2710 defining this will force the i2c_read() function in
2711 the soft_i2c driver to perform an I2C repeated start
2712 between writing the address pointer and reading the
2713 data. If this define is omitted the default behaviour
2714 of doing a stop-start sequence will be used. Most I2C
2715 devices can use either method, but some require one or
2718 - SPI Support: CONFIG_SPI
2720 Enables SPI driver (so far only tested with
2721 SPI EEPROM, also an instance works with Crystal A/D and
2722 D/As on the SACSng board)
2726 Enables the driver for SPI controller on SuperH. Currently
2727 only SH7757 is supported.
2731 Enables extended (16-bit) SPI EEPROM addressing.
2732 (symmetrical to CONFIG_I2C_X)
2736 Enables a software (bit-bang) SPI driver rather than
2737 using hardware support. This is a general purpose
2738 driver that only requires three general I/O port pins
2739 (two outputs, one input) to function. If this is
2740 defined, the board configuration must define several
2741 SPI configuration items (port pins to use, etc). For
2742 an example, see include/configs/sacsng.h.
2746 Enables a hardware SPI driver for general-purpose reads
2747 and writes. As with CONFIG_SOFT_SPI, the board configuration
2748 must define a list of chip-select function pointers.
2749 Currently supported on some MPC8xxx processors. For an
2750 example, see include/configs/mpc8349emds.h.
2754 Enables the driver for the SPI controllers on i.MX and MXC
2755 SoCs. Currently i.MX31/35/51 are supported.
2757 CONFIG_SYS_SPI_MXC_WAIT
2758 Timeout for waiting until spi transfer completed.
2759 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2761 - FPGA Support: CONFIG_FPGA
2763 Enables FPGA subsystem.
2765 CONFIG_FPGA_<vendor>
2767 Enables support for specific chip vendors.
2770 CONFIG_FPGA_<family>
2772 Enables support for FPGA family.
2773 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2777 Specify the number of FPGA devices to support.
2779 CONFIG_CMD_FPGA_LOADMK
2781 Enable support for fpga loadmk command
2783 CONFIG_CMD_FPGA_LOADP
2785 Enable support for fpga loadp command - load partial bitstream
2787 CONFIG_CMD_FPGA_LOADBP
2789 Enable support for fpga loadbp command - load partial bitstream
2792 CONFIG_SYS_FPGA_PROG_FEEDBACK
2794 Enable printing of hash marks during FPGA configuration.
2796 CONFIG_SYS_FPGA_CHECK_BUSY
2798 Enable checks on FPGA configuration interface busy
2799 status by the configuration function. This option
2800 will require a board or device specific function to
2805 If defined, a function that provides delays in the FPGA
2806 configuration driver.
2808 CONFIG_SYS_FPGA_CHECK_CTRLC
2809 Allow Control-C to interrupt FPGA configuration
2811 CONFIG_SYS_FPGA_CHECK_ERROR
2813 Check for configuration errors during FPGA bitfile
2814 loading. For example, abort during Virtex II
2815 configuration if the INIT_B line goes low (which
2816 indicated a CRC error).
2818 CONFIG_SYS_FPGA_WAIT_INIT
2820 Maximum time to wait for the INIT_B line to deassert
2821 after PROB_B has been deasserted during a Virtex II
2822 FPGA configuration sequence. The default time is 500
2825 CONFIG_SYS_FPGA_WAIT_BUSY
2827 Maximum time to wait for BUSY to deassert during
2828 Virtex II FPGA configuration. The default is 5 ms.
2830 CONFIG_SYS_FPGA_WAIT_CONFIG
2832 Time to wait after FPGA configuration. The default is
2835 - Configuration Management:
2838 Some SoCs need special image types (e.g. U-Boot binary
2839 with a special header) as build targets. By defining
2840 CONFIG_BUILD_TARGET in the SoC / board header, this
2841 special image will be automatically built upon calling
2846 If defined, this string will be added to the U-Boot
2847 version information (U_BOOT_VERSION)
2849 - Vendor Parameter Protection:
2851 U-Boot considers the values of the environment
2852 variables "serial#" (Board Serial Number) and
2853 "ethaddr" (Ethernet Address) to be parameters that
2854 are set once by the board vendor / manufacturer, and
2855 protects these variables from casual modification by
2856 the user. Once set, these variables are read-only,
2857 and write or delete attempts are rejected. You can
2858 change this behaviour:
2860 If CONFIG_ENV_OVERWRITE is #defined in your config
2861 file, the write protection for vendor parameters is
2862 completely disabled. Anybody can change or delete
2865 Alternatively, if you #define _both_ CONFIG_ETHADDR
2866 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2867 Ethernet address is installed in the environment,
2868 which can be changed exactly ONCE by the user. [The
2869 serial# is unaffected by this, i. e. it remains
2872 The same can be accomplished in a more flexible way
2873 for any variable by configuring the type of access
2874 to allow for those variables in the ".flags" variable
2875 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2880 Define this variable to enable the reservation of
2881 "protected RAM", i. e. RAM which is not overwritten
2882 by U-Boot. Define CONFIG_PRAM to hold the number of
2883 kB you want to reserve for pRAM. You can overwrite
2884 this default value by defining an environment
2885 variable "pram" to the number of kB you want to
2886 reserve. Note that the board info structure will
2887 still show the full amount of RAM. If pRAM is
2888 reserved, a new environment variable "mem" will
2889 automatically be defined to hold the amount of
2890 remaining RAM in a form that can be passed as boot
2891 argument to Linux, for instance like that:
2893 setenv bootargs ... mem=\${mem}
2896 This way you can tell Linux not to use this memory,
2897 either, which results in a memory region that will
2898 not be affected by reboots.
2900 *WARNING* If your board configuration uses automatic
2901 detection of the RAM size, you must make sure that
2902 this memory test is non-destructive. So far, the
2903 following board configurations are known to be
2906 IVMS8, IVML24, SPD8xx, TQM8xxL,
2907 HERMES, IP860, RPXlite, LWMON,
2910 - Access to physical memory region (> 4GB)
2911 Some basic support is provided for operations on memory not
2912 normally accessible to U-Boot - e.g. some architectures
2913 support access to more than 4GB of memory on 32-bit
2914 machines using physical address extension or similar.
2915 Define CONFIG_PHYSMEM to access this basic support, which
2916 currently only supports clearing the memory.
2921 Define this variable to stop the system in case of a
2922 fatal error, so that you have to reset it manually.
2923 This is probably NOT a good idea for an embedded
2924 system where you want the system to reboot
2925 automatically as fast as possible, but it may be
2926 useful during development since you can try to debug
2927 the conditions that lead to the situation.
2929 CONFIG_NET_RETRY_COUNT
2931 This variable defines the number of retries for
2932 network operations like ARP, RARP, TFTP, or BOOTP
2933 before giving up the operation. If not defined, a
2934 default value of 5 is used.
2938 Timeout waiting for an ARP reply in milliseconds.
2942 Timeout in milliseconds used in NFS protocol.
2943 If you encounter "ERROR: Cannot umount" in nfs command,
2944 try longer timeout such as
2945 #define CONFIG_NFS_TIMEOUT 10000UL
2947 - Command Interpreter:
2948 CONFIG_AUTO_COMPLETE
2950 Enable auto completion of commands using TAB.
2952 CONFIG_SYS_PROMPT_HUSH_PS2
2954 This defines the secondary prompt string, which is
2955 printed when the command interpreter needs more input
2956 to complete a command. Usually "> ".
2960 In the current implementation, the local variables
2961 space and global environment variables space are
2962 separated. Local variables are those you define by
2963 simply typing `name=value'. To access a local
2964 variable later on, you have write `$name' or
2965 `${name}'; to execute the contents of a variable
2966 directly type `$name' at the command prompt.
2968 Global environment variables are those you use
2969 setenv/printenv to work with. To run a command stored
2970 in such a variable, you need to use the run command,
2971 and you must not use the '$' sign to access them.
2973 To store commands and special characters in a
2974 variable, please use double quotation marks
2975 surrounding the whole text of the variable, instead
2976 of the backslashes before semicolons and special
2979 - Commandline Editing and History:
2980 CONFIG_CMDLINE_EDITING
2982 Enable editing and History functions for interactive
2983 commandline input operations
2985 - Default Environment:
2986 CONFIG_EXTRA_ENV_SETTINGS
2988 Define this to contain any number of null terminated
2989 strings (variable = value pairs) that will be part of
2990 the default environment compiled into the boot image.
2992 For example, place something like this in your
2993 board's config file:
2995 #define CONFIG_EXTRA_ENV_SETTINGS \
2999 Warning: This method is based on knowledge about the
3000 internal format how the environment is stored by the
3001 U-Boot code. This is NOT an official, exported
3002 interface! Although it is unlikely that this format
3003 will change soon, there is no guarantee either.
3004 You better know what you are doing here.
3006 Note: overly (ab)use of the default environment is
3007 discouraged. Make sure to check other ways to preset
3008 the environment like the "source" command or the
3011 CONFIG_ENV_VARS_UBOOT_CONFIG
3013 Define this in order to add variables describing the
3014 U-Boot build configuration to the default environment.
3015 These will be named arch, cpu, board, vendor, and soc.
3017 Enabling this option will cause the following to be defined:
3025 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3027 Define this in order to add variables describing certain
3028 run-time determined information about the hardware to the
3029 environment. These will be named board_name, board_rev.
3031 CONFIG_DELAY_ENVIRONMENT
3033 Normally the environment is loaded when the board is
3034 intialised so that it is available to U-Boot. This inhibits
3035 that so that the environment is not available until
3036 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3037 this is instead controlled by the value of
3038 /config/load-environment.
3040 - DataFlash Support:
3041 CONFIG_HAS_DATAFLASH
3043 Defining this option enables DataFlash features and
3044 allows to read/write in Dataflash via the standard
3047 - Serial Flash support
3050 Defining this option enables SPI flash commands
3051 'sf probe/read/write/erase/update'.
3053 Usage requires an initial 'probe' to define the serial
3054 flash parameters, followed by read/write/erase/update
3057 The following defaults may be provided by the platform
3058 to handle the common case when only a single serial
3059 flash is present on the system.
3061 CONFIG_SF_DEFAULT_BUS Bus identifier
3062 CONFIG_SF_DEFAULT_CS Chip-select
3063 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3064 CONFIG_SF_DEFAULT_SPEED in Hz
3068 Define this option to include a destructive SPI flash
3071 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3073 Define this option to use the Bank addr/Extended addr
3074 support on SPI flashes which has size > 16Mbytes.
3076 CONFIG_SF_DUAL_FLASH Dual flash memories
3078 Define this option to use dual flash support where two flash
3079 memories can be connected with a given cs line.
3080 currently Xilinx Zynq qspi support these type of connections.
3082 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3083 enable the W#/Vpp signal to disable writing to the status
3084 register on ST MICRON flashes like the N25Q128.
3085 The status register write enable/disable bit, combined with
3086 the W#/VPP signal provides hardware data protection for the
3087 device as follows: When the enable/disable bit is set to 1,
3088 and the W#/VPP signal is driven LOW, the status register
3089 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3090 operation will not execute. The only way to exit this
3091 hardware-protected mode is to drive W#/VPP HIGH.
3093 - SystemACE Support:
3096 Adding this option adds support for Xilinx SystemACE
3097 chips attached via some sort of local bus. The address
3098 of the chip must also be defined in the
3099 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3101 #define CONFIG_SYSTEMACE
3102 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3104 When SystemACE support is added, the "ace" device type
3105 becomes available to the fat commands, i.e. fatls.
3107 - TFTP Fixed UDP Port:
3110 If this is defined, the environment variable tftpsrcp
3111 is used to supply the TFTP UDP source port value.
3112 If tftpsrcp isn't defined, the normal pseudo-random port
3113 number generator is used.
3115 Also, the environment variable tftpdstp is used to supply
3116 the TFTP UDP destination port value. If tftpdstp isn't
3117 defined, the normal port 69 is used.
3119 The purpose for tftpsrcp is to allow a TFTP server to
3120 blindly start the TFTP transfer using the pre-configured
3121 target IP address and UDP port. This has the effect of
3122 "punching through" the (Windows XP) firewall, allowing
3123 the remainder of the TFTP transfer to proceed normally.
3124 A better solution is to properly configure the firewall,
3125 but sometimes that is not allowed.
3130 This enables a generic 'hash' command which can produce
3131 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3135 Enable the hash verify command (hash -v). This adds to code
3138 CONFIG_SHA1 - support SHA1 hashing
3139 CONFIG_SHA256 - support SHA256 hashing
3141 Note: There is also a sha1sum command, which should perhaps
3142 be deprecated in favour of 'hash sha1'.
3144 - Freescale i.MX specific commands:
3145 CONFIG_CMD_HDMIDETECT
3146 This enables 'hdmidet' command which returns true if an
3147 HDMI monitor is detected. This command is i.MX 6 specific.
3150 This enables the 'bmode' (bootmode) command for forcing
3151 a boot from specific media.
3153 This is useful for forcing the ROM's usb downloader to
3154 activate upon a watchdog reset which is nice when iterating
3155 on U-Boot. Using the reset button or running bmode normal
3156 will set it back to normal. This command currently
3157 supports i.MX53 and i.MX6.
3162 This enables the RSA algorithm used for FIT image verification
3163 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3165 The signing part is build into mkimage regardless of this
3168 - bootcount support:
3169 CONFIG_BOOTCOUNT_LIMIT
3171 This enables the bootcounter support, see:
3172 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3175 enable special bootcounter support on at91sam9xe based boards.
3177 enable special bootcounter support on blackfin based boards.
3179 enable special bootcounter support on da850 based boards.
3180 CONFIG_BOOTCOUNT_RAM
3181 enable support for the bootcounter in RAM
3182 CONFIG_BOOTCOUNT_I2C
3183 enable support for the bootcounter on an i2c (like RTC) device.
3184 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3185 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3187 CONFIG_BOOTCOUNT_ALEN = address len
3189 - Show boot progress:
3190 CONFIG_SHOW_BOOT_PROGRESS
3192 Defining this option allows to add some board-
3193 specific code (calling a user-provided function
3194 "show_boot_progress(int)") that enables you to show
3195 the system's boot progress on some display (for
3196 example, some LED's) on your board. At the moment,
3197 the following checkpoints are implemented:
3199 - Detailed boot stage timing
3201 Define this option to get detailed timing of each stage
3202 of the boot process.
3204 CONFIG_BOOTSTAGE_USER_COUNT
3205 This is the number of available user bootstage records.
3206 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3207 a new ID will be allocated from this stash. If you exceed
3208 the limit, recording will stop.
3210 CONFIG_BOOTSTAGE_REPORT
3211 Define this to print a report before boot, similar to this:
3213 Timer summary in microseconds:
3216 3,575,678 3,575,678 board_init_f start
3217 3,575,695 17 arch_cpu_init A9
3218 3,575,777 82 arch_cpu_init done
3219 3,659,598 83,821 board_init_r start
3220 3,910,375 250,777 main_loop
3221 29,916,167 26,005,792 bootm_start
3222 30,361,327 445,160 start_kernel
3224 CONFIG_CMD_BOOTSTAGE
3225 Add a 'bootstage' command which supports printing a report
3226 and un/stashing of bootstage data.
3228 CONFIG_BOOTSTAGE_FDT
3229 Stash the bootstage information in the FDT. A root 'bootstage'
3230 node is created with each bootstage id as a child. Each child
3231 has a 'name' property and either 'mark' containing the
3232 mark time in microsecond, or 'accum' containing the
3233 accumulated time for that bootstage id in microseconds.
3238 name = "board_init_f";
3247 Code in the Linux kernel can find this in /proc/devicetree.
3249 Legacy uImage format:
3252 1 common/cmd_bootm.c before attempting to boot an image
3253 -1 common/cmd_bootm.c Image header has bad magic number
3254 2 common/cmd_bootm.c Image header has correct magic number
3255 -2 common/cmd_bootm.c Image header has bad checksum
3256 3 common/cmd_bootm.c Image header has correct checksum
3257 -3 common/cmd_bootm.c Image data has bad checksum
3258 4 common/cmd_bootm.c Image data has correct checksum
3259 -4 common/cmd_bootm.c Image is for unsupported architecture
3260 5 common/cmd_bootm.c Architecture check OK
3261 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3262 6 common/cmd_bootm.c Image Type check OK
3263 -6 common/cmd_bootm.c gunzip uncompression error
3264 -7 common/cmd_bootm.c Unimplemented compression type
3265 7 common/cmd_bootm.c Uncompression OK
3266 8 common/cmd_bootm.c No uncompress/copy overwrite error
3267 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3269 9 common/image.c Start initial ramdisk verification
3270 -10 common/image.c Ramdisk header has bad magic number
3271 -11 common/image.c Ramdisk header has bad checksum
3272 10 common/image.c Ramdisk header is OK
3273 -12 common/image.c Ramdisk data has bad checksum
3274 11 common/image.c Ramdisk data has correct checksum
3275 12 common/image.c Ramdisk verification complete, start loading
3276 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3277 13 common/image.c Start multifile image verification
3278 14 common/image.c No initial ramdisk, no multifile, continue.
3280 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3282 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3283 -31 post/post.c POST test failed, detected by post_output_backlog()
3284 -32 post/post.c POST test failed, detected by post_run_single()
3286 34 common/cmd_doc.c before loading a Image from a DOC device
3287 -35 common/cmd_doc.c Bad usage of "doc" command
3288 35 common/cmd_doc.c correct usage of "doc" command
3289 -36 common/cmd_doc.c No boot device
3290 36 common/cmd_doc.c correct boot device
3291 -37 common/cmd_doc.c Unknown Chip ID on boot device
3292 37 common/cmd_doc.c correct chip ID found, device available
3293 -38 common/cmd_doc.c Read Error on boot device
3294 38 common/cmd_doc.c reading Image header from DOC device OK
3295 -39 common/cmd_doc.c Image header has bad magic number
3296 39 common/cmd_doc.c Image header has correct magic number
3297 -40 common/cmd_doc.c Error reading Image from DOC device
3298 40 common/cmd_doc.c Image header has correct magic number
3299 41 common/cmd_ide.c before loading a Image from a IDE device
3300 -42 common/cmd_ide.c Bad usage of "ide" command
3301 42 common/cmd_ide.c correct usage of "ide" command
3302 -43 common/cmd_ide.c No boot device
3303 43 common/cmd_ide.c boot device found
3304 -44 common/cmd_ide.c Device not available
3305 44 common/cmd_ide.c Device available
3306 -45 common/cmd_ide.c wrong partition selected
3307 45 common/cmd_ide.c partition selected
3308 -46 common/cmd_ide.c Unknown partition table
3309 46 common/cmd_ide.c valid partition table found
3310 -47 common/cmd_ide.c Invalid partition type
3311 47 common/cmd_ide.c correct partition type
3312 -48 common/cmd_ide.c Error reading Image Header on boot device
3313 48 common/cmd_ide.c reading Image Header from IDE device OK
3314 -49 common/cmd_ide.c Image header has bad magic number
3315 49 common/cmd_ide.c Image header has correct magic number
3316 -50 common/cmd_ide.c Image header has bad checksum
3317 50 common/cmd_ide.c Image header has correct checksum
3318 -51 common/cmd_ide.c Error reading Image from IDE device
3319 51 common/cmd_ide.c reading Image from IDE device OK
3320 52 common/cmd_nand.c before loading a Image from a NAND device
3321 -53 common/cmd_nand.c Bad usage of "nand" command
3322 53 common/cmd_nand.c correct usage of "nand" command
3323 -54 common/cmd_nand.c No boot device
3324 54 common/cmd_nand.c boot device found
3325 -55 common/cmd_nand.c Unknown Chip ID on boot device
3326 55 common/cmd_nand.c correct chip ID found, device available
3327 -56 common/cmd_nand.c Error reading Image Header on boot device
3328 56 common/cmd_nand.c reading Image Header from NAND device OK
3329 -57 common/cmd_nand.c Image header has bad magic number
3330 57 common/cmd_nand.c Image header has correct magic number
3331 -58 common/cmd_nand.c Error reading Image from NAND device
3332 58 common/cmd_nand.c reading Image from NAND device OK
3334 -60 common/env_common.c Environment has a bad CRC, using default
3336 64 net/eth.c starting with Ethernet configuration.
3337 -64 net/eth.c no Ethernet found.
3338 65 net/eth.c Ethernet found.
3340 -80 common/cmd_net.c usage wrong
3341 80 common/cmd_net.c before calling NetLoop()
3342 -81 common/cmd_net.c some error in NetLoop() occurred
3343 81 common/cmd_net.c NetLoop() back without error
3344 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3345 82 common/cmd_net.c trying automatic boot
3346 83 common/cmd_net.c running "source" command
3347 -83 common/cmd_net.c some error in automatic boot or "source" command
3348 84 common/cmd_net.c end without errors
3353 100 common/cmd_bootm.c Kernel FIT Image has correct format
3354 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3355 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3356 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3357 102 common/cmd_bootm.c Kernel unit name specified
3358 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3359 103 common/cmd_bootm.c Found configuration node
3360 104 common/cmd_bootm.c Got kernel subimage node offset
3361 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3362 105 common/cmd_bootm.c Kernel subimage hash verification OK
3363 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3364 106 common/cmd_bootm.c Architecture check OK
3365 -106 common/cmd_bootm.c Kernel subimage has wrong type
3366 107 common/cmd_bootm.c Kernel subimage type OK
3367 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3368 108 common/cmd_bootm.c Got kernel subimage data/size
3369 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3370 -109 common/cmd_bootm.c Can't get kernel subimage type
3371 -110 common/cmd_bootm.c Can't get kernel subimage comp
3372 -111 common/cmd_bootm.c Can't get kernel subimage os
3373 -112 common/cmd_bootm.c Can't get kernel subimage load address
3374 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3376 120 common/image.c Start initial ramdisk verification
3377 -120 common/image.c Ramdisk FIT image has incorrect format
3378 121 common/image.c Ramdisk FIT image has correct format
3379 122 common/image.c No ramdisk subimage unit name, using configuration
3380 -122 common/image.c Can't get configuration for ramdisk subimage
3381 123 common/image.c Ramdisk unit name specified
3382 -124 common/image.c Can't get ramdisk subimage node offset
3383 125 common/image.c Got ramdisk subimage node offset
3384 -125 common/image.c Ramdisk subimage hash verification failed
3385 126 common/image.c Ramdisk subimage hash verification OK
3386 -126 common/image.c Ramdisk subimage for unsupported architecture
3387 127 common/image.c Architecture check OK
3388 -127 common/image.c Can't get ramdisk subimage data/size
3389 128 common/image.c Got ramdisk subimage data/size
3390 129 common/image.c Can't get ramdisk load address
3391 -129 common/image.c Got ramdisk load address
3393 -130 common/cmd_doc.c Incorrect FIT image format
3394 131 common/cmd_doc.c FIT image format OK
3396 -140 common/cmd_ide.c Incorrect FIT image format
3397 141 common/cmd_ide.c FIT image format OK
3399 -150 common/cmd_nand.c Incorrect FIT image format
3400 151 common/cmd_nand.c FIT image format OK
3402 - legacy image format:
3403 CONFIG_IMAGE_FORMAT_LEGACY
3404 enables the legacy image format support in U-Boot.
3407 enabled if CONFIG_FIT_SIGNATURE is not defined.
3409 CONFIG_DISABLE_IMAGE_LEGACY
3410 disable the legacy image format
3412 This define is introduced, as the legacy image format is
3413 enabled per default for backward compatibility.
3415 - FIT image support:
3417 Enable support for the FIT uImage format.
3419 CONFIG_FIT_BEST_MATCH
3420 When no configuration is explicitly selected, default to the
3421 one whose fdt's compatibility field best matches that of
3422 U-Boot itself. A match is considered "best" if it matches the
3423 most specific compatibility entry of U-Boot's fdt's root node.
3424 The order of entries in the configuration's fdt is ignored.
3426 CONFIG_FIT_SIGNATURE
3427 This option enables signature verification of FIT uImages,
3428 using a hash signed and verified using RSA. See
3429 doc/uImage.FIT/signature.txt for more details.
3431 WARNING: When relying on signed FIT images with required
3432 signature check the legacy image format is default
3433 disabled. If a board need legacy image format support
3434 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3436 CONFIG_FIT_DISABLE_SHA256
3437 Supporting SHA256 hashes has quite an impact on binary size.
3438 For constrained systems sha256 hash support can be disabled
3441 - Standalone program support:
3442 CONFIG_STANDALONE_LOAD_ADDR
3444 This option defines a board specific value for the
3445 address where standalone program gets loaded, thus
3446 overwriting the architecture dependent default
3449 - Frame Buffer Address:
3452 Define CONFIG_FB_ADDR if you want to use specific
3453 address for frame buffer. This is typically the case
3454 when using a graphics controller has separate video
3455 memory. U-Boot will then place the frame buffer at
3456 the given address instead of dynamically reserving it
3457 in system RAM by calling lcd_setmem(), which grabs
3458 the memory for the frame buffer depending on the
3459 configured panel size.
3461 Please see board_init_f function.
3463 - Automatic software updates via TFTP server
3465 CONFIG_UPDATE_TFTP_CNT_MAX
3466 CONFIG_UPDATE_TFTP_MSEC_MAX
3468 These options enable and control the auto-update feature;
3469 for a more detailed description refer to doc/README.update.
3471 - MTD Support (mtdparts command, UBI support)
3474 Adds the MTD device infrastructure from the Linux kernel.
3475 Needed for mtdparts command support.
3477 CONFIG_MTD_PARTITIONS
3479 Adds the MTD partitioning infrastructure from the Linux
3480 kernel. Needed for UBI support.
3482 CONFIG_MTD_NAND_VERIFY_WRITE
3483 verify if the written data is correct reread.
3488 Adds commands for interacting with MTD partitions formatted
3489 with the UBI flash translation layer
3491 Requires also defining CONFIG_RBTREE
3493 CONFIG_UBI_SILENCE_MSG
3495 Make the verbose messages from UBI stop printing. This leaves
3496 warnings and errors enabled.
3499 CONFIG_MTD_UBI_WL_THRESHOLD
3500 This parameter defines the maximum difference between the highest
3501 erase counter value and the lowest erase counter value of eraseblocks
3502 of UBI devices. When this threshold is exceeded, UBI starts performing
3503 wear leveling by means of moving data from eraseblock with low erase
3504 counter to eraseblocks with high erase counter.
3506 The default value should be OK for SLC NAND flashes, NOR flashes and
3507 other flashes which have eraseblock life-cycle 100000 or more.
3508 However, in case of MLC NAND flashes which typically have eraseblock
3509 life-cycle less than 10000, the threshold should be lessened (e.g.,
3510 to 128 or 256, although it does not have to be power of 2).
3514 CONFIG_MTD_UBI_BEB_LIMIT
3515 This option specifies the maximum bad physical eraseblocks UBI
3516 expects on the MTD device (per 1024 eraseblocks). If the
3517 underlying flash does not admit of bad eraseblocks (e.g. NOR
3518 flash), this value is ignored.
3520 NAND datasheets often specify the minimum and maximum NVM
3521 (Number of Valid Blocks) for the flashes' endurance lifetime.
3522 The maximum expected bad eraseblocks per 1024 eraseblocks
3523 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3524 which gives 20 for most NANDs (MaxNVB is basically the total
3525 count of eraseblocks on the chip).
3527 To put it differently, if this value is 20, UBI will try to
3528 reserve about 1.9% of physical eraseblocks for bad blocks
3529 handling. And that will be 1.9% of eraseblocks on the entire
3530 NAND chip, not just the MTD partition UBI attaches. This means
3531 that if you have, say, a NAND flash chip admits maximum 40 bad
3532 eraseblocks, and it is split on two MTD partitions of the same
3533 size, UBI will reserve 40 eraseblocks when attaching a
3538 CONFIG_MTD_UBI_FASTMAP
3539 Fastmap is a mechanism which allows attaching an UBI device
3540 in nearly constant time. Instead of scanning the whole MTD device it
3541 only has to locate a checkpoint (called fastmap) on the device.
3542 The on-flash fastmap contains all information needed to attach
3543 the device. Using fastmap makes only sense on large devices where
3544 attaching by scanning takes long. UBI will not automatically install
3545 a fastmap on old images, but you can set the UBI parameter
3546 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3547 that fastmap-enabled images are still usable with UBI implementations
3548 without fastmap support. On typical flash devices the whole fastmap
3549 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3551 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3552 Set this parameter to enable fastmap automatically on images
3559 Adds commands for interacting with UBI volumes formatted as
3560 UBIFS. UBIFS is read-only in u-boot.
3562 Requires UBI support as well as CONFIG_LZO
3564 CONFIG_UBIFS_SILENCE_MSG
3566 Make the verbose messages from UBIFS stop printing. This leaves
3567 warnings and errors enabled.
3571 Enable building of SPL globally.
3574 LDSCRIPT for linking the SPL binary.
3576 CONFIG_SPL_MAX_FOOTPRINT
3577 Maximum size in memory allocated to the SPL, BSS included.
3578 When defined, the linker checks that the actual memory
3579 used by SPL from _start to __bss_end does not exceed it.
3580 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3581 must not be both defined at the same time.
3584 Maximum size of the SPL image (text, data, rodata, and
3585 linker lists sections), BSS excluded.
3586 When defined, the linker checks that the actual size does
3589 CONFIG_SPL_TEXT_BASE
3590 TEXT_BASE for linking the SPL binary.
3592 CONFIG_SPL_RELOC_TEXT_BASE
3593 Address to relocate to. If unspecified, this is equal to
3594 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3596 CONFIG_SPL_BSS_START_ADDR
3597 Link address for the BSS within the SPL binary.
3599 CONFIG_SPL_BSS_MAX_SIZE
3600 Maximum size in memory allocated to the SPL BSS.
3601 When defined, the linker checks that the actual memory used
3602 by SPL from __bss_start to __bss_end does not exceed it.
3603 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3604 must not be both defined at the same time.
3607 Adress of the start of the stack SPL will use
3609 CONFIG_SPL_RELOC_STACK
3610 Adress of the start of the stack SPL will use after
3611 relocation. If unspecified, this is equal to
3614 CONFIG_SYS_SPL_MALLOC_START
3615 Starting address of the malloc pool used in SPL.
3617 CONFIG_SYS_SPL_MALLOC_SIZE
3618 The size of the malloc pool used in SPL.
3620 CONFIG_SPL_FRAMEWORK
3621 Enable the SPL framework under common/. This framework
3622 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3623 NAND loading of the Linux Kernel.
3626 Enable booting directly to an OS from SPL.
3627 See also: doc/README.falcon
3629 CONFIG_SPL_DISPLAY_PRINT
3630 For ARM, enable an optional function to print more information
3631 about the running system.
3633 CONFIG_SPL_INIT_MINIMAL
3634 Arch init code should be built for a very small image
3636 CONFIG_SPL_LIBCOMMON_SUPPORT
3637 Support for common/libcommon.o in SPL binary
3639 CONFIG_SPL_LIBDISK_SUPPORT
3640 Support for disk/libdisk.o in SPL binary
3642 CONFIG_SPL_I2C_SUPPORT
3643 Support for drivers/i2c/libi2c.o in SPL binary
3645 CONFIG_SPL_GPIO_SUPPORT
3646 Support for drivers/gpio/libgpio.o in SPL binary
3648 CONFIG_SPL_MMC_SUPPORT
3649 Support for drivers/mmc/libmmc.o in SPL binary
3651 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3652 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3653 CONFIG_SYS_MMC_SD_FS_BOOT_PARTITION
3654 Address, size and partition on the MMC to load U-Boot from
3655 when the MMC is being used in raw mode.
3657 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3658 Sector to load kernel uImage from when MMC is being
3659 used in raw mode (for Falcon mode)
3661 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3662 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3663 Sector and number of sectors to load kernel argument
3664 parameters from when MMC is being used in raw mode
3667 CONFIG_SPL_FAT_SUPPORT
3668 Support for fs/fat/libfat.o in SPL binary
3670 CONFIG_SPL_EXT_SUPPORT
3671 Support for EXT filesystem in SPL binary
3673 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3674 Filename to read to load U-Boot when reading from filesystem
3676 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3677 Filename to read to load kernel uImage when reading
3678 from filesystem (for Falcon mode)
3680 CONFIG_SPL_FS_LOAD_ARGS_NAME
3681 Filename to read to load kernel argument parameters
3682 when reading from filesystem (for Falcon mode)
3684 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3685 Set this for NAND SPL on PPC mpc83xx targets, so that
3686 start.S waits for the rest of the SPL to load before
3687 continuing (the hardware starts execution after just
3688 loading the first page rather than the full 4K).
3690 CONFIG_SPL_SKIP_RELOCATE
3691 Avoid SPL relocation
3693 CONFIG_SPL_NAND_BASE
3694 Include nand_base.c in the SPL. Requires
3695 CONFIG_SPL_NAND_DRIVERS.
3697 CONFIG_SPL_NAND_DRIVERS
3698 SPL uses normal NAND drivers, not minimal drivers.
3701 Include standard software ECC in the SPL
3703 CONFIG_SPL_NAND_SIMPLE
3704 Support for NAND boot using simple NAND drivers that
3705 expose the cmd_ctrl() interface.
3707 CONFIG_SPL_MTD_SUPPORT
3708 Support for the MTD subsystem within SPL. Useful for
3709 environment on NAND support within SPL.
3711 CONFIG_SPL_NAND_RAW_ONLY
3712 Support to boot only raw u-boot.bin images. Use this only
3713 if you need to save space.
3715 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3716 Set for the SPL on PPC mpc8xxx targets, support for
3717 drivers/ddr/fsl/libddr.o in SPL binary.
3719 CONFIG_SPL_COMMON_INIT_DDR
3720 Set for common ddr init with serial presence detect in
3723 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3724 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3725 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3726 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3727 CONFIG_SYS_NAND_ECCBYTES
3728 Defines the size and behavior of the NAND that SPL uses
3731 CONFIG_SPL_NAND_BOOT
3732 Add support NAND boot
3734 CONFIG_SYS_NAND_U_BOOT_OFFS
3735 Location in NAND to read U-Boot from
3737 CONFIG_SYS_NAND_U_BOOT_DST
3738 Location in memory to load U-Boot to
3740 CONFIG_SYS_NAND_U_BOOT_SIZE
3741 Size of image to load
3743 CONFIG_SYS_NAND_U_BOOT_START
3744 Entry point in loaded image to jump to
3746 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3747 Define this if you need to first read the OOB and then the
3748 data. This is used for example on davinci plattforms.
3750 CONFIG_SPL_OMAP3_ID_NAND
3751 Support for an OMAP3-specific set of functions to return the
3752 ID and MFR of the first attached NAND chip, if present.
3754 CONFIG_SPL_SERIAL_SUPPORT
3755 Support for drivers/serial/libserial.o in SPL binary
3757 CONFIG_SPL_SPI_FLASH_SUPPORT
3758 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3760 CONFIG_SPL_SPI_SUPPORT
3761 Support for drivers/spi/libspi.o in SPL binary
3763 CONFIG_SPL_RAM_DEVICE
3764 Support for running image already present in ram, in SPL binary
3766 CONFIG_SPL_LIBGENERIC_SUPPORT
3767 Support for lib/libgeneric.o in SPL binary
3769 CONFIG_SPL_ENV_SUPPORT
3770 Support for the environment operating in SPL binary
3772 CONFIG_SPL_NET_SUPPORT
3773 Support for the net/libnet.o in SPL binary.
3774 It conflicts with SPL env from storage medium specified by
3775 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3778 Image offset to which the SPL should be padded before appending
3779 the SPL payload. By default, this is defined as
3780 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3781 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3782 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3785 Final target image containing SPL and payload. Some SPLs
3786 use an arch-specific makefile fragment instead, for
3787 example if more than one image needs to be produced.
3789 CONFIG_FIT_SPL_PRINT
3790 Printing information about a FIT image adds quite a bit of
3791 code to SPL. So this is normally disabled in SPL. Use this
3792 option to re-enable it. This will affect the output of the
3793 bootm command when booting a FIT image.
3797 Enable building of TPL globally.
3800 Image offset to which the TPL should be padded before appending
3801 the TPL payload. By default, this is defined as
3802 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3803 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3804 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3809 [so far only for SMDK2400 boards]
3811 - Modem support enable:
3812 CONFIG_MODEM_SUPPORT
3814 - RTS/CTS Flow control enable:
3817 - Modem debug support:
3818 CONFIG_MODEM_SUPPORT_DEBUG
3820 Enables debugging stuff (char screen[1024], dbg())
3821 for modem support. Useful only with BDI2000.
3823 - Interrupt support (PPC):
3825 There are common interrupt_init() and timer_interrupt()
3826 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3827 for CPU specific initialization. interrupt_init_cpu()
3828 should set decrementer_count to appropriate value. If
3829 CPU resets decrementer automatically after interrupt
3830 (ppc4xx) it should set decrementer_count to zero.
3831 timer_interrupt() calls timer_interrupt_cpu() for CPU
3832 specific handling. If board has watchdog / status_led
3833 / other_activity_monitor it works automatically from
3834 general timer_interrupt().
3838 In the target system modem support is enabled when a
3839 specific key (key combination) is pressed during
3840 power-on. Otherwise U-Boot will boot normally
3841 (autoboot). The key_pressed() function is called from
3842 board_init(). Currently key_pressed() is a dummy
3843 function, returning 1 and thus enabling modem
3846 If there are no modem init strings in the
3847 environment, U-Boot proceed to autoboot; the
3848 previous output (banner, info printfs) will be
3851 See also: doc/README.Modem
3853 Board initialization settings:
3854 ------------------------------
3856 During Initialization u-boot calls a number of board specific functions
3857 to allow the preparation of board specific prerequisites, e.g. pin setup
3858 before drivers are initialized. To enable these callbacks the
3859 following configuration macros have to be defined. Currently this is
3860 architecture specific, so please check arch/your_architecture/lib/board.c
3861 typically in board_init_f() and board_init_r().
3863 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3864 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3865 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3866 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3868 Configuration Settings:
3869 -----------------------
3871 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3872 Optionally it can be defined to support 64-bit memory commands.
3874 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3875 undefine this when you're short of memory.
3877 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3878 width of the commands listed in the 'help' command output.
3880 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3881 prompt for user input.
3883 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3885 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3887 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3889 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3890 the application (usually a Linux kernel) when it is
3893 - CONFIG_SYS_BAUDRATE_TABLE:
3894 List of legal baudrate settings for this board.
3896 - CONFIG_SYS_CONSOLE_INFO_QUIET
3897 Suppress display of console information at boot.
3899 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3900 If the board specific function
3901 extern int overwrite_console (void);
3902 returns 1, the stdin, stderr and stdout are switched to the
3903 serial port, else the settings in the environment are used.
3905 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3906 Enable the call to overwrite_console().
3908 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3909 Enable overwrite of previous console environment settings.
3911 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3912 Begin and End addresses of the area used by the
3915 - CONFIG_SYS_ALT_MEMTEST:
3916 Enable an alternate, more extensive memory test.
3918 - CONFIG_SYS_MEMTEST_SCRATCH:
3919 Scratch address used by the alternate memory test
3920 You only need to set this if address zero isn't writeable
3922 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3923 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3924 this specified memory area will get subtracted from the top
3925 (end) of RAM and won't get "touched" at all by U-Boot. By
3926 fixing up gd->ram_size the Linux kernel should gets passed
3927 the now "corrected" memory size and won't touch it either.
3928 This should work for arch/ppc and arch/powerpc. Only Linux
3929 board ports in arch/powerpc with bootwrapper support that
3930 recalculate the memory size from the SDRAM controller setup
3931 will have to get fixed in Linux additionally.
3933 This option can be used as a workaround for the 440EPx/GRx
3934 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3937 WARNING: Please make sure that this value is a multiple of
3938 the Linux page size (normally 4k). If this is not the case,
3939 then the end address of the Linux memory will be located at a
3940 non page size aligned address and this could cause major
3943 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3944 Enable temporary baudrate change while serial download
3946 - CONFIG_SYS_SDRAM_BASE:
3947 Physical start address of SDRAM. _Must_ be 0 here.
3949 - CONFIG_SYS_MBIO_BASE:
3950 Physical start address of Motherboard I/O (if using a
3953 - CONFIG_SYS_FLASH_BASE:
3954 Physical start address of Flash memory.
3956 - CONFIG_SYS_MONITOR_BASE:
3957 Physical start address of boot monitor code (set by
3958 make config files to be same as the text base address
3959 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3960 CONFIG_SYS_FLASH_BASE when booting from flash.
3962 - CONFIG_SYS_MONITOR_LEN:
3963 Size of memory reserved for monitor code, used to
3964 determine _at_compile_time_ (!) if the environment is
3965 embedded within the U-Boot image, or in a separate
3968 - CONFIG_SYS_MALLOC_LEN:
3969 Size of DRAM reserved for malloc() use.
3971 - CONFIG_SYS_MALLOC_F_LEN
3972 Size of the malloc() pool for use before relocation. If
3973 this is defined, then a very simple malloc() implementation
3974 will become available before relocation. The address is just
3975 below the global data, and the stack is moved down to make
3978 This feature allocates regions with increasing addresses
3979 within the region. calloc() is supported, but realloc()
3980 is not available. free() is supported but does nothing.
3981 The memory will be freed (or in fact just forgotton) when
3982 U-Boot relocates itself.
3984 Pre-relocation malloc() is only supported on ARM and sandbox
3985 at present but is fairly easy to enable for other archs.
3987 - CONFIG_SYS_MALLOC_SIMPLE
3988 Provides a simple and small malloc() and calloc() for those
3989 boards which do not use the full malloc in SPL (which is
3990 enabled with CONFIG_SYS_SPL_MALLOC_START).
3992 - CONFIG_SYS_BOOTM_LEN:
3993 Normally compressed uImages are limited to an
3994 uncompressed size of 8 MBytes. If this is not enough,
3995 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3996 to adjust this setting to your needs.
3998 - CONFIG_SYS_BOOTMAPSZ:
3999 Maximum size of memory mapped by the startup code of
4000 the Linux kernel; all data that must be processed by
4001 the Linux kernel (bd_info, boot arguments, FDT blob if
4002 used) must be put below this limit, unless "bootm_low"
4003 environment variable is defined and non-zero. In such case
4004 all data for the Linux kernel must be between "bootm_low"
4005 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4006 variable "bootm_mapsize" will override the value of
4007 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4008 then the value in "bootm_size" will be used instead.
4010 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4011 Enable initrd_high functionality. If defined then the
4012 initrd_high feature is enabled and the bootm ramdisk subcommand
4015 - CONFIG_SYS_BOOT_GET_CMDLINE:
4016 Enables allocating and saving kernel cmdline in space between
4017 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4019 - CONFIG_SYS_BOOT_GET_KBD:
4020 Enables allocating and saving a kernel copy of the bd_info in
4021 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4023 - CONFIG_SYS_MAX_FLASH_BANKS:
4024 Max number of Flash memory banks
4026 - CONFIG_SYS_MAX_FLASH_SECT:
4027 Max number of sectors on a Flash chip
4029 - CONFIG_SYS_FLASH_ERASE_TOUT:
4030 Timeout for Flash erase operations (in ms)
4032 - CONFIG_SYS_FLASH_WRITE_TOUT:
4033 Timeout for Flash write operations (in ms)
4035 - CONFIG_SYS_FLASH_LOCK_TOUT
4036 Timeout for Flash set sector lock bit operation (in ms)
4038 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4039 Timeout for Flash clear lock bits operation (in ms)
4041 - CONFIG_SYS_FLASH_PROTECTION
4042 If defined, hardware flash sectors protection is used
4043 instead of U-Boot software protection.
4045 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4047 Enable TFTP transfers directly to flash memory;
4048 without this option such a download has to be
4049 performed in two steps: (1) download to RAM, and (2)
4050 copy from RAM to flash.
4052 The two-step approach is usually more reliable, since
4053 you can check if the download worked before you erase
4054 the flash, but in some situations (when system RAM is
4055 too limited to allow for a temporary copy of the
4056 downloaded image) this option may be very useful.
4058 - CONFIG_SYS_FLASH_CFI:
4059 Define if the flash driver uses extra elements in the
4060 common flash structure for storing flash geometry.
4062 - CONFIG_FLASH_CFI_DRIVER
4063 This option also enables the building of the cfi_flash driver
4064 in the drivers directory
4066 - CONFIG_FLASH_CFI_MTD
4067 This option enables the building of the cfi_mtd driver
4068 in the drivers directory. The driver exports CFI flash
4071 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4072 Use buffered writes to flash.
4074 - CONFIG_FLASH_SPANSION_S29WS_N
4075 s29ws-n MirrorBit flash has non-standard addresses for buffered
4078 - CONFIG_SYS_FLASH_QUIET_TEST
4079 If this option is defined, the common CFI flash doesn't
4080 print it's warning upon not recognized FLASH banks. This
4081 is useful, if some of the configured banks are only
4082 optionally available.
4084 - CONFIG_FLASH_SHOW_PROGRESS
4085 If defined (must be an integer), print out countdown
4086 digits and dots. Recommended value: 45 (9..1) for 80
4087 column displays, 15 (3..1) for 40 column displays.
4089 - CONFIG_FLASH_VERIFY
4090 If defined, the content of the flash (destination) is compared
4091 against the source after the write operation. An error message
4092 will be printed when the contents are not identical.
4093 Please note that this option is useless in nearly all cases,
4094 since such flash programming errors usually are detected earlier
4095 while unprotecting/erasing/programming. Please only enable
4096 this option if you really know what you are doing.
4098 - CONFIG_SYS_RX_ETH_BUFFER:
4099 Defines the number of Ethernet receive buffers. On some
4100 Ethernet controllers it is recommended to set this value
4101 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4102 buffers can be full shortly after enabling the interface
4103 on high Ethernet traffic.
4104 Defaults to 4 if not defined.
4106 - CONFIG_ENV_MAX_ENTRIES
4108 Maximum number of entries in the hash table that is used
4109 internally to store the environment settings. The default
4110 setting is supposed to be generous and should work in most
4111 cases. This setting can be used to tune behaviour; see
4112 lib/hashtable.c for details.
4114 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4115 - CONFIG_ENV_FLAGS_LIST_STATIC
4116 Enable validation of the values given to environment variables when
4117 calling env set. Variables can be restricted to only decimal,
4118 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4119 the variables can also be restricted to IP address or MAC address.
4121 The format of the list is:
4122 type_attribute = [s|d|x|b|i|m]
4123 access_atribute = [a|r|o|c]
4124 attributes = type_attribute[access_atribute]
4125 entry = variable_name[:attributes]
4128 The type attributes are:
4129 s - String (default)
4132 b - Boolean ([1yYtT|0nNfF])
4136 The access attributes are:
4142 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4143 Define this to a list (string) to define the ".flags"
4144 envirnoment variable in the default or embedded environment.
4146 - CONFIG_ENV_FLAGS_LIST_STATIC
4147 Define this to a list (string) to define validation that
4148 should be done if an entry is not found in the ".flags"
4149 environment variable. To override a setting in the static
4150 list, simply add an entry for the same variable name to the
4153 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4154 If defined, don't allow the -f switch to env set override variable
4157 - CONFIG_SYS_GENERIC_BOARD
4158 This selects the architecture-generic board system instead of the
4159 architecture-specific board files. It is intended to move boards
4160 to this new framework over time. Defining this will disable the
4161 arch/foo/lib/board.c file and use common/board_f.c and
4162 common/board_r.c instead. To use this option your architecture
4163 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4164 its config.mk file). If you find problems enabling this option on
4165 your board please report the problem and send patches!
4167 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4168 This is set by OMAP boards for the max time that reset should
4169 be asserted. See doc/README.omap-reset-time for details on how
4170 the value can be calulated on a given board.
4173 If stdint.h is available with your toolchain you can define this
4174 option to enable it. You can provide option 'USE_STDINT=1' when
4175 building U-Boot to enable this.
4177 The following definitions that deal with the placement and management
4178 of environment data (variable area); in general, we support the
4179 following configurations:
4181 - CONFIG_BUILD_ENVCRC:
4183 Builds up envcrc with the target environment so that external utils
4184 may easily extract it and embed it in final U-Boot images.
4186 - CONFIG_ENV_IS_IN_FLASH:
4188 Define this if the environment is in flash memory.
4190 a) The environment occupies one whole flash sector, which is
4191 "embedded" in the text segment with the U-Boot code. This
4192 happens usually with "bottom boot sector" or "top boot
4193 sector" type flash chips, which have several smaller
4194 sectors at the start or the end. For instance, such a
4195 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4196 such a case you would place the environment in one of the
4197 4 kB sectors - with U-Boot code before and after it. With
4198 "top boot sector" type flash chips, you would put the
4199 environment in one of the last sectors, leaving a gap
4200 between U-Boot and the environment.
4202 - CONFIG_ENV_OFFSET:
4204 Offset of environment data (variable area) to the
4205 beginning of flash memory; for instance, with bottom boot
4206 type flash chips the second sector can be used: the offset
4207 for this sector is given here.
4209 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4213 This is just another way to specify the start address of
4214 the flash sector containing the environment (instead of
4217 - CONFIG_ENV_SECT_SIZE:
4219 Size of the sector containing the environment.
4222 b) Sometimes flash chips have few, equal sized, BIG sectors.
4223 In such a case you don't want to spend a whole sector for
4228 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4229 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4230 of this flash sector for the environment. This saves
4231 memory for the RAM copy of the environment.
4233 It may also save flash memory if you decide to use this
4234 when your environment is "embedded" within U-Boot code,
4235 since then the remainder of the flash sector could be used
4236 for U-Boot code. It should be pointed out that this is
4237 STRONGLY DISCOURAGED from a robustness point of view:
4238 updating the environment in flash makes it always
4239 necessary to erase the WHOLE sector. If something goes
4240 wrong before the contents has been restored from a copy in
4241 RAM, your target system will be dead.
4243 - CONFIG_ENV_ADDR_REDUND
4244 CONFIG_ENV_SIZE_REDUND
4246 These settings describe a second storage area used to hold
4247 a redundant copy of the environment data, so that there is
4248 a valid backup copy in case there is a power failure during
4249 a "saveenv" operation.
4251 BE CAREFUL! Any changes to the flash layout, and some changes to the
4252 source code will make it necessary to adapt <board>/u-boot.lds*
4256 - CONFIG_ENV_IS_IN_NVRAM:
4258 Define this if you have some non-volatile memory device
4259 (NVRAM, battery buffered SRAM) which you want to use for the
4265 These two #defines are used to determine the memory area you
4266 want to use for environment. It is assumed that this memory
4267 can just be read and written to, without any special
4270 BE CAREFUL! The first access to the environment happens quite early
4271 in U-Boot initalization (when we try to get the setting of for the
4272 console baudrate). You *MUST* have mapped your NVRAM area then, or
4275 Please note that even with NVRAM we still use a copy of the
4276 environment in RAM: we could work on NVRAM directly, but we want to
4277 keep settings there always unmodified except somebody uses "saveenv"
4278 to save the current settings.
4281 - CONFIG_ENV_IS_IN_EEPROM:
4283 Use this if you have an EEPROM or similar serial access
4284 device and a driver for it.
4286 - CONFIG_ENV_OFFSET:
4289 These two #defines specify the offset and size of the
4290 environment area within the total memory of your EEPROM.
4292 - CONFIG_SYS_I2C_EEPROM_ADDR:
4293 If defined, specified the chip address of the EEPROM device.
4294 The default address is zero.
4296 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4297 If defined, the number of bits used to address bytes in a
4298 single page in the EEPROM device. A 64 byte page, for example
4299 would require six bits.
4301 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4302 If defined, the number of milliseconds to delay between
4303 page writes. The default is zero milliseconds.
4305 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4306 The length in bytes of the EEPROM memory array address. Note
4307 that this is NOT the chip address length!
4309 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4310 EEPROM chips that implement "address overflow" are ones
4311 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4312 address and the extra bits end up in the "chip address" bit
4313 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4316 Note that we consider the length of the address field to
4317 still be one byte because the extra address bits are hidden
4318 in the chip address.
4320 - CONFIG_SYS_EEPROM_SIZE:
4321 The size in bytes of the EEPROM device.
4323 - CONFIG_ENV_EEPROM_IS_ON_I2C
4324 define this, if you have I2C and SPI activated, and your
4325 EEPROM, which holds the environment, is on the I2C bus.
4327 - CONFIG_I2C_ENV_EEPROM_BUS
4328 if you have an Environment on an EEPROM reached over
4329 I2C muxes, you can define here, how to reach this
4330 EEPROM. For example:
4332 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4334 EEPROM which holds the environment, is reached over
4335 a pca9547 i2c mux with address 0x70, channel 3.
4337 - CONFIG_ENV_IS_IN_DATAFLASH:
4339 Define this if you have a DataFlash memory device which you
4340 want to use for the environment.
4342 - CONFIG_ENV_OFFSET:
4346 These three #defines specify the offset and size of the
4347 environment area within the total memory of your DataFlash placed
4348 at the specified address.
4350 - CONFIG_ENV_IS_IN_SPI_FLASH:
4352 Define this if you have a SPI Flash memory device which you
4353 want to use for the environment.
4355 - CONFIG_ENV_OFFSET:
4358 These two #defines specify the offset and size of the
4359 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4360 aligned to an erase sector boundary.
4362 - CONFIG_ENV_SECT_SIZE:
4364 Define the SPI flash's sector size.
4366 - CONFIG_ENV_OFFSET_REDUND (optional):
4368 This setting describes a second storage area of CONFIG_ENV_SIZE
4369 size used to hold a redundant copy of the environment data, so
4370 that there is a valid backup copy in case there is a power failure
4371 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4372 aligned to an erase sector boundary.
4374 - CONFIG_ENV_SPI_BUS (optional):
4375 - CONFIG_ENV_SPI_CS (optional):
4377 Define the SPI bus and chip select. If not defined they will be 0.
4379 - CONFIG_ENV_SPI_MAX_HZ (optional):
4381 Define the SPI max work clock. If not defined then use 1MHz.
4383 - CONFIG_ENV_SPI_MODE (optional):
4385 Define the SPI work mode. If not defined then use SPI_MODE_3.
4387 - CONFIG_ENV_IS_IN_REMOTE:
4389 Define this if you have a remote memory space which you
4390 want to use for the local device's environment.
4395 These two #defines specify the address and size of the
4396 environment area within the remote memory space. The
4397 local device can get the environment from remote memory
4398 space by SRIO or PCIE links.
4400 BE CAREFUL! For some special cases, the local device can not use
4401 "saveenv" command. For example, the local device will get the
4402 environment stored in a remote NOR flash by SRIO or PCIE link,
4403 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4405 - CONFIG_ENV_IS_IN_NAND:
4407 Define this if you have a NAND device which you want to use
4408 for the environment.
4410 - CONFIG_ENV_OFFSET:
4413 These two #defines specify the offset and size of the environment
4414 area within the first NAND device. CONFIG_ENV_OFFSET must be
4415 aligned to an erase block boundary.
4417 - CONFIG_ENV_OFFSET_REDUND (optional):
4419 This setting describes a second storage area of CONFIG_ENV_SIZE
4420 size used to hold a redundant copy of the environment data, so
4421 that there is a valid backup copy in case there is a power failure
4422 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4423 aligned to an erase block boundary.
4425 - CONFIG_ENV_RANGE (optional):
4427 Specifies the length of the region in which the environment
4428 can be written. This should be a multiple of the NAND device's
4429 block size. Specifying a range with more erase blocks than
4430 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4431 the range to be avoided.
4433 - CONFIG_ENV_OFFSET_OOB (optional):
4435 Enables support for dynamically retrieving the offset of the
4436 environment from block zero's out-of-band data. The
4437 "nand env.oob" command can be used to record this offset.
4438 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4439 using CONFIG_ENV_OFFSET_OOB.
4441 - CONFIG_NAND_ENV_DST
4443 Defines address in RAM to which the nand_spl code should copy the
4444 environment. If redundant environment is used, it will be copied to
4445 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4447 - CONFIG_ENV_IS_IN_UBI:
4449 Define this if you have an UBI volume that you want to use for the
4450 environment. This has the benefit of wear-leveling the environment
4451 accesses, which is important on NAND.
4453 - CONFIG_ENV_UBI_PART:
4455 Define this to a string that is the mtd partition containing the UBI.
4457 - CONFIG_ENV_UBI_VOLUME:
4459 Define this to the name of the volume that you want to store the
4462 - CONFIG_ENV_UBI_VOLUME_REDUND:
4464 Define this to the name of another volume to store a second copy of
4465 the environment in. This will enable redundant environments in UBI.
4466 It is assumed that both volumes are in the same MTD partition.
4468 - CONFIG_UBI_SILENCE_MSG
4469 - CONFIG_UBIFS_SILENCE_MSG
4471 You will probably want to define these to avoid a really noisy system
4472 when storing the env in UBI.
4474 - CONFIG_ENV_IS_IN_FAT:
4475 Define this if you want to use the FAT file system for the environment.
4477 - FAT_ENV_INTERFACE:
4479 Define this to a string that is the name of the block device.
4481 - FAT_ENV_DEV_AND_PART:
4483 Define this to a string to specify the partition of the device. It can
4486 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4487 - "D:P": device D partition P. Error occurs if device D has no
4490 - "D" or "D:": device D partition 1 if device D has partition
4491 table, or the whole device D if has no partition
4493 - "D:auto": first partition in device D with bootable flag set.
4494 If none, first valid paratition in device D. If no
4495 partition table then means device D.
4499 It's a string of the FAT file name. This file use to store the
4503 This should be defined. Otherwise it cannot save the envrionment file.
4505 - CONFIG_ENV_IS_IN_MMC:
4507 Define this if you have an MMC device which you want to use for the
4510 - CONFIG_SYS_MMC_ENV_DEV:
4512 Specifies which MMC device the environment is stored in.
4514 - CONFIG_SYS_MMC_ENV_PART (optional):
4516 Specifies which MMC partition the environment is stored in. If not
4517 set, defaults to partition 0, the user area. Common values might be
4518 1 (first MMC boot partition), 2 (second MMC boot partition).
4520 - CONFIG_ENV_OFFSET:
4523 These two #defines specify the offset and size of the environment
4524 area within the specified MMC device.
4526 If offset is positive (the usual case), it is treated as relative to
4527 the start of the MMC partition. If offset is negative, it is treated
4528 as relative to the end of the MMC partition. This can be useful if
4529 your board may be fitted with different MMC devices, which have
4530 different sizes for the MMC partitions, and you always want the
4531 environment placed at the very end of the partition, to leave the
4532 maximum possible space before it, to store other data.
4534 These two values are in units of bytes, but must be aligned to an
4535 MMC sector boundary.
4537 - CONFIG_ENV_OFFSET_REDUND (optional):
4539 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4540 hold a redundant copy of the environment data. This provides a
4541 valid backup copy in case the other copy is corrupted, e.g. due
4542 to a power failure during a "saveenv" operation.
4544 This value may also be positive or negative; this is handled in the
4545 same way as CONFIG_ENV_OFFSET.
4547 This value is also in units of bytes, but must also be aligned to
4548 an MMC sector boundary.
4550 - CONFIG_ENV_SIZE_REDUND (optional):
4552 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4553 set. If this value is set, it must be set to the same value as
4556 - CONFIG_SYS_SPI_INIT_OFFSET
4558 Defines offset to the initial SPI buffer area in DPRAM. The
4559 area is used at an early stage (ROM part) if the environment
4560 is configured to reside in the SPI EEPROM: We need a 520 byte
4561 scratch DPRAM area. It is used between the two initialization
4562 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4563 to be a good choice since it makes it far enough from the
4564 start of the data area as well as from the stack pointer.
4566 Please note that the environment is read-only until the monitor
4567 has been relocated to RAM and a RAM copy of the environment has been
4568 created; also, when using EEPROM you will have to use getenv_f()
4569 until then to read environment variables.
4571 The environment is protected by a CRC32 checksum. Before the monitor
4572 is relocated into RAM, as a result of a bad CRC you will be working
4573 with the compiled-in default environment - *silently*!!! [This is
4574 necessary, because the first environment variable we need is the
4575 "baudrate" setting for the console - if we have a bad CRC, we don't
4576 have any device yet where we could complain.]
4578 Note: once the monitor has been relocated, then it will complain if
4579 the default environment is used; a new CRC is computed as soon as you
4580 use the "saveenv" command to store a valid environment.
4582 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4583 Echo the inverted Ethernet link state to the fault LED.
4585 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4586 also needs to be defined.
4588 - CONFIG_SYS_FAULT_MII_ADDR:
4589 MII address of the PHY to check for the Ethernet link state.
4591 - CONFIG_NS16550_MIN_FUNCTIONS:
4592 Define this if you desire to only have use of the NS16550_init
4593 and NS16550_putc functions for the serial driver located at
4594 drivers/serial/ns16550.c. This option is useful for saving
4595 space for already greatly restricted images, including but not
4596 limited to NAND_SPL configurations.
4598 - CONFIG_DISPLAY_BOARDINFO
4599 Display information about the board that U-Boot is running on
4600 when U-Boot starts up. The board function checkboard() is called
4603 - CONFIG_DISPLAY_BOARDINFO_LATE
4604 Similar to the previous option, but display this information
4605 later, once stdio is running and output goes to the LCD, if
4608 - CONFIG_BOARD_SIZE_LIMIT:
4609 Maximum size of the U-Boot image. When defined, the
4610 build system checks that the actual size does not
4613 Low Level (hardware related) configuration options:
4614 ---------------------------------------------------
4616 - CONFIG_SYS_CACHELINE_SIZE:
4617 Cache Line Size of the CPU.
4619 - CONFIG_SYS_DEFAULT_IMMR:
4620 Default address of the IMMR after system reset.
4622 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4623 and RPXsuper) to be able to adjust the position of
4624 the IMMR register after a reset.
4626 - CONFIG_SYS_CCSRBAR_DEFAULT:
4627 Default (power-on reset) physical address of CCSR on Freescale
4630 - CONFIG_SYS_CCSRBAR:
4631 Virtual address of CCSR. On a 32-bit build, this is typically
4632 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4634 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4635 for cross-platform code that uses that macro instead.
4637 - CONFIG_SYS_CCSRBAR_PHYS:
4638 Physical address of CCSR. CCSR can be relocated to a new
4639 physical address, if desired. In this case, this macro should
4640 be set to that address. Otherwise, it should be set to the
4641 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4642 is typically relocated on 36-bit builds. It is recommended
4643 that this macro be defined via the _HIGH and _LOW macros:
4645 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4646 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4648 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4649 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4650 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4651 used in assembly code, so it must not contain typecasts or
4652 integer size suffixes (e.g. "ULL").
4654 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4655 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4656 used in assembly code, so it must not contain typecasts or
4657 integer size suffixes (e.g. "ULL").
4659 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4660 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4661 forced to a value that ensures that CCSR is not relocated.
4663 - Floppy Disk Support:
4664 CONFIG_SYS_FDC_DRIVE_NUMBER
4666 the default drive number (default value 0)
4668 CONFIG_SYS_ISA_IO_STRIDE
4670 defines the spacing between FDC chipset registers
4673 CONFIG_SYS_ISA_IO_OFFSET
4675 defines the offset of register from address. It
4676 depends on which part of the data bus is connected to
4677 the FDC chipset. (default value 0)
4679 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4680 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4683 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4684 fdc_hw_init() is called at the beginning of the FDC
4685 setup. fdc_hw_init() must be provided by the board
4686 source code. It is used to make hardware dependant
4690 Most IDE controllers were designed to be connected with PCI
4691 interface. Only few of them were designed for AHB interface.
4692 When software is doing ATA command and data transfer to
4693 IDE devices through IDE-AHB controller, some additional
4694 registers accessing to these kind of IDE-AHB controller
4697 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4698 DO NOT CHANGE unless you know exactly what you're
4699 doing! (11-4) [MPC8xx/82xx systems only]
4701 - CONFIG_SYS_INIT_RAM_ADDR:
4703 Start address of memory area that can be used for
4704 initial data and stack; please note that this must be
4705 writable memory that is working WITHOUT special
4706 initialization, i. e. you CANNOT use normal RAM which
4707 will become available only after programming the
4708 memory controller and running certain initialization
4711 U-Boot uses the following memory types:
4712 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4713 - MPC824X: data cache
4714 - PPC4xx: data cache
4716 - CONFIG_SYS_GBL_DATA_OFFSET:
4718 Offset of the initial data structure in the memory
4719 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4720 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4721 data is located at the end of the available space
4722 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4723 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4724 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4725 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4728 On the MPC824X (or other systems that use the data
4729 cache for initial memory) the address chosen for
4730 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4731 point to an otherwise UNUSED address space between
4732 the top of RAM and the start of the PCI space.
4734 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4736 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4738 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4740 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4742 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4744 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4746 - CONFIG_SYS_OR_TIMING_SDRAM:
4749 - CONFIG_SYS_MAMR_PTA:
4750 periodic timer for refresh
4752 - CONFIG_SYS_DER: Debug Event Register (37-47)
4754 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4755 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4756 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4757 CONFIG_SYS_BR1_PRELIM:
4758 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4760 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4761 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4762 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4763 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4765 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4766 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4767 Machine Mode Register and Memory Periodic Timer
4768 Prescaler definitions (SDRAM timing)
4770 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4771 enable I2C microcode relocation patch (MPC8xx);
4772 define relocation offset in DPRAM [DSP2]
4774 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4775 enable SMC microcode relocation patch (MPC8xx);
4776 define relocation offset in DPRAM [SMC1]
4778 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4779 enable SPI microcode relocation patch (MPC8xx);
4780 define relocation offset in DPRAM [SCC4]
4782 - CONFIG_SYS_USE_OSCCLK:
4783 Use OSCM clock mode on MBX8xx board. Be careful,
4784 wrong setting might damage your board. Read
4785 doc/README.MBX before setting this variable!
4787 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4788 Offset of the bootmode word in DPRAM used by post
4789 (Power On Self Tests). This definition overrides
4790 #define'd default value in commproc.h resp.
4793 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4794 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4795 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4796 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4797 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4798 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4799 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4800 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4801 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4803 - CONFIG_PCI_DISABLE_PCIE:
4804 Disable PCI-Express on systems where it is supported but not
4807 - CONFIG_PCI_ENUM_ONLY
4808 Only scan through and get the devices on the busses.
4809 Don't do any setup work, presumably because someone or
4810 something has already done it, and we don't need to do it
4811 a second time. Useful for platforms that are pre-booted
4812 by coreboot or similar.
4814 - CONFIG_PCI_INDIRECT_BRIDGE:
4815 Enable support for indirect PCI bridges.
4818 Chip has SRIO or not
4821 Board has SRIO 1 port available
4824 Board has SRIO 2 port available
4826 - CONFIG_SRIO_PCIE_BOOT_MASTER
4827 Board can support master function for Boot from SRIO and PCIE
4829 - CONFIG_SYS_SRIOn_MEM_VIRT:
4830 Virtual Address of SRIO port 'n' memory region
4832 - CONFIG_SYS_SRIOn_MEM_PHYS:
4833 Physical Address of SRIO port 'n' memory region
4835 - CONFIG_SYS_SRIOn_MEM_SIZE:
4836 Size of SRIO port 'n' memory region
4838 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4839 Defined to tell the NAND controller that the NAND chip is using
4841 Not all NAND drivers use this symbol.
4842 Example of drivers that use it:
4843 - drivers/mtd/nand/ndfc.c
4844 - drivers/mtd/nand/mxc_nand.c
4846 - CONFIG_SYS_NDFC_EBC0_CFG
4847 Sets the EBC0_CFG register for the NDFC. If not defined
4848 a default value will be used.
4851 Get DDR timing information from an I2C EEPROM. Common
4852 with pluggable memory modules such as SODIMMs
4855 I2C address of the SPD EEPROM
4857 - CONFIG_SYS_SPD_BUS_NUM
4858 If SPD EEPROM is on an I2C bus other than the first
4859 one, specify here. Note that the value must resolve
4860 to something your driver can deal with.
4862 - CONFIG_SYS_DDR_RAW_TIMING
4863 Get DDR timing information from other than SPD. Common with
4864 soldered DDR chips onboard without SPD. DDR raw timing
4865 parameters are extracted from datasheet and hard-coded into
4866 header files or board specific files.
4868 - CONFIG_FSL_DDR_INTERACTIVE
4869 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4871 - CONFIG_SYS_83XX_DDR_USES_CS0
4872 Only for 83xx systems. If specified, then DDR should
4873 be configured using CS0 and CS1 instead of CS2 and CS3.
4875 - CONFIG_ETHER_ON_FEC[12]
4876 Define to enable FEC[12] on a 8xx series processor.
4878 - CONFIG_FEC[12]_PHY
4879 Define to the hardcoded PHY address which corresponds
4880 to the given FEC; i. e.
4881 #define CONFIG_FEC1_PHY 4
4882 means that the PHY with address 4 is connected to FEC1
4884 When set to -1, means to probe for first available.
4886 - CONFIG_FEC[12]_PHY_NORXERR
4887 The PHY does not have a RXERR line (RMII only).
4888 (so program the FEC to ignore it).
4891 Enable RMII mode for all FECs.
4892 Note that this is a global option, we can't
4893 have one FEC in standard MII mode and another in RMII mode.
4895 - CONFIG_CRC32_VERIFY
4896 Add a verify option to the crc32 command.
4899 => crc32 -v <address> <count> <crc32>
4901 Where address/count indicate a memory area
4902 and crc32 is the correct crc32 which the
4906 Add the "loopw" memory command. This only takes effect if
4907 the memory commands are activated globally (CONFIG_CMD_MEM).
4910 Add the "mdc" and "mwc" memory commands. These are cyclic
4915 This command will print 4 bytes (10,11,12,13) each 500 ms.
4917 => mwc.l 100 12345678 10
4918 This command will write 12345678 to address 100 all 10 ms.
4920 This only takes effect if the memory commands are activated
4921 globally (CONFIG_CMD_MEM).
4923 - CONFIG_SKIP_LOWLEVEL_INIT
4924 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4925 low level initializations (like setting up the memory
4926 controller) are omitted and/or U-Boot does not
4927 relocate itself into RAM.
4929 Normally this variable MUST NOT be defined. The only
4930 exception is when U-Boot is loaded (to RAM) by some
4931 other boot loader or by a debugger which performs
4932 these initializations itself.
4935 Modifies the behaviour of start.S when compiling a loader
4936 that is executed before the actual U-Boot. E.g. when
4937 compiling a NAND SPL.
4940 Modifies the behaviour of start.S when compiling a loader
4941 that is executed after the SPL and before the actual U-Boot.
4942 It is loaded by the SPL.
4944 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4945 Only for 85xx systems. If this variable is specified, the section
4946 .resetvec is not kept and the section .bootpg is placed in the
4947 previous 4k of the .text section.
4949 - CONFIG_ARCH_MAP_SYSMEM
4950 Generally U-Boot (and in particular the md command) uses
4951 effective address. It is therefore not necessary to regard
4952 U-Boot address as virtual addresses that need to be translated
4953 to physical addresses. However, sandbox requires this, since
4954 it maintains its own little RAM buffer which contains all
4955 addressable memory. This option causes some memory accesses
4956 to be mapped through map_sysmem() / unmap_sysmem().
4958 - CONFIG_USE_ARCH_MEMCPY
4959 CONFIG_USE_ARCH_MEMSET
4960 If these options are used a optimized version of memcpy/memset will
4961 be used if available. These functions may be faster under some
4962 conditions but may increase the binary size.
4964 - CONFIG_X86_RESET_VECTOR
4965 If defined, the x86 reset vector code is included. This is not
4966 needed when U-Boot is running from Coreboot.
4969 Defines the MPU clock speed (in MHz).
4971 NOTE : currently only supported on AM335x platforms.
4973 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4974 Enables the RTC32K OSC on AM33xx based plattforms
4976 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4977 Option to disable subpage write in NAND driver
4978 driver that uses this:
4979 drivers/mtd/nand/davinci_nand.c
4981 Freescale QE/FMAN Firmware Support:
4982 -----------------------------------
4984 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4985 loading of "firmware", which is encoded in the QE firmware binary format.
4986 This firmware often needs to be loaded during U-Boot booting, so macros
4987 are used to identify the storage device (NOR flash, SPI, etc) and the address
4990 - CONFIG_SYS_FMAN_FW_ADDR
4991 The address in the storage device where the FMAN microcode is located. The
4992 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4995 - CONFIG_SYS_QE_FW_ADDR
4996 The address in the storage device where the QE microcode is located. The
4997 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5000 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5001 The maximum possible size of the firmware. The firmware binary format
5002 has a field that specifies the actual size of the firmware, but it
5003 might not be possible to read any part of the firmware unless some
5004 local storage is allocated to hold the entire firmware first.
5006 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5007 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5008 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5009 virtual address in NOR flash.
5011 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5012 Specifies that QE/FMAN firmware is located in NAND flash.
5013 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5015 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5016 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5017 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5019 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5020 Specifies that QE/FMAN firmware is located on the primary SPI
5021 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5023 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5024 Specifies that QE/FMAN firmware is located in the remote (master)
5025 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5026 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5027 window->master inbound window->master LAW->the ucode address in
5028 master's memory space.
5030 Freescale Layerscape Management Complex Firmware Support:
5031 ---------------------------------------------------------
5032 The Freescale Layerscape Management Complex (MC) supports the loading of
5034 This firmware often needs to be loaded during U-Boot booting, so macros
5035 are used to identify the storage device (NOR flash, SPI, etc) and the address
5038 - CONFIG_FSL_MC_ENET
5039 Enable the MC driver for Layerscape SoCs.
5041 - CONFIG_SYS_LS_MC_FW_ADDR
5042 The address in the storage device where the firmware is located. The
5043 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5046 - CONFIG_SYS_LS_MC_FW_LENGTH
5047 The maximum possible size of the firmware. The firmware binary format
5048 has a field that specifies the actual size of the firmware, but it
5049 might not be possible to read any part of the firmware unless some
5050 local storage is allocated to hold the entire firmware first.
5052 - CONFIG_SYS_LS_MC_FW_IN_NOR
5053 Specifies that MC firmware is located in NOR flash, mapped as
5054 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5055 virtual address in NOR flash.
5057 Building the Software:
5058 ======================
5060 Building U-Boot has been tested in several native build environments
5061 and in many different cross environments. Of course we cannot support
5062 all possibly existing versions of cross development tools in all
5063 (potentially obsolete) versions. In case of tool chain problems we
5064 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5065 which is extensively used to build and test U-Boot.
5067 If you are not using a native environment, it is assumed that you
5068 have GNU cross compiling tools available in your path. In this case,
5069 you must set the environment variable CROSS_COMPILE in your shell.
5070 Note that no changes to the Makefile or any other source files are
5071 necessary. For example using the ELDK on a 4xx CPU, please enter:
5073 $ CROSS_COMPILE=ppc_4xx-
5074 $ export CROSS_COMPILE
5076 Note: If you wish to generate Windows versions of the utilities in
5077 the tools directory you can use the MinGW toolchain
5078 (http://www.mingw.org). Set your HOST tools to the MinGW
5079 toolchain and execute 'make tools'. For example:
5081 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5083 Binaries such as tools/mkimage.exe will be created which can
5084 be executed on computers running Windows.
5086 U-Boot is intended to be simple to build. After installing the
5087 sources you must configure U-Boot for one specific board type. This
5092 where "NAME_defconfig" is the name of one of the existing configu-
5093 rations; see boards.cfg for supported names.
5095 Note: for some board special configuration names may exist; check if
5096 additional information is available from the board vendor; for
5097 instance, the TQM823L systems are available without (standard)
5098 or with LCD support. You can select such additional "features"
5099 when choosing the configuration, i. e.
5101 make TQM823L_defconfig
5102 - will configure for a plain TQM823L, i. e. no LCD support
5104 make TQM823L_LCD_defconfig
5105 - will configure for a TQM823L with U-Boot console on LCD
5110 Finally, type "make all", and you should get some working U-Boot
5111 images ready for download to / installation on your system:
5113 - "u-boot.bin" is a raw binary image
5114 - "u-boot" is an image in ELF binary format
5115 - "u-boot.srec" is in Motorola S-Record format
5117 By default the build is performed locally and the objects are saved
5118 in the source directory. One of the two methods can be used to change
5119 this behavior and build U-Boot to some external directory:
5121 1. Add O= to the make command line invocations:
5123 make O=/tmp/build distclean
5124 make O=/tmp/build NAME_defconfig
5125 make O=/tmp/build all
5127 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5129 export KBUILD_OUTPUT=/tmp/build
5134 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5138 Please be aware that the Makefiles assume you are using GNU make, so
5139 for instance on NetBSD you might need to use "gmake" instead of
5143 If the system board that you have is not listed, then you will need
5144 to port U-Boot to your hardware platform. To do this, follow these
5147 1. Add a new configuration option for your board to the toplevel
5148 "boards.cfg" file, using the existing entries as examples.
5149 Follow the instructions there to keep the boards in order.
5150 2. Create a new directory to hold your board specific code. Add any
5151 files you need. In your board directory, you will need at least
5152 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5153 3. Create a new configuration file "include/configs/<board>.h" for
5155 3. If you're porting U-Boot to a new CPU, then also create a new
5156 directory to hold your CPU specific code. Add any files you need.
5157 4. Run "make <board>_defconfig" with your new name.
5158 5. Type "make", and you should get a working "u-boot.srec" file
5159 to be installed on your target system.
5160 6. Debug and solve any problems that might arise.
5161 [Of course, this last step is much harder than it sounds.]
5164 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5165 ==============================================================
5167 If you have modified U-Boot sources (for instance added a new board
5168 or support for new devices, a new CPU, etc.) you are expected to
5169 provide feedback to the other developers. The feedback normally takes
5170 the form of a "patch", i. e. a context diff against a certain (latest
5171 official or latest in the git repository) version of U-Boot sources.
5173 But before you submit such a patch, please verify that your modifi-
5174 cation did not break existing code. At least make sure that *ALL* of
5175 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5176 just run the "MAKEALL" script, which will configure and build U-Boot
5177 for ALL supported system. Be warned, this will take a while. You can
5178 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5179 environment variable to the script, i. e. to use the ELDK cross tools
5182 CROSS_COMPILE=ppc_8xx- MAKEALL
5184 or to build on a native PowerPC system you can type
5186 CROSS_COMPILE=' ' MAKEALL
5188 When using the MAKEALL script, the default behaviour is to build
5189 U-Boot in the source directory. This location can be changed by
5190 setting the BUILD_DIR environment variable. Also, for each target
5191 built, the MAKEALL script saves two log files (<target>.ERR and
5192 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5193 location can be changed by setting the MAKEALL_LOGDIR environment
5194 variable. For example:
5196 export BUILD_DIR=/tmp/build
5197 export MAKEALL_LOGDIR=/tmp/log
5198 CROSS_COMPILE=ppc_8xx- MAKEALL
5200 With the above settings build objects are saved in the /tmp/build,
5201 log files are saved in the /tmp/log and the source tree remains clean
5202 during the whole build process.
5205 See also "U-Boot Porting Guide" below.
5208 Monitor Commands - Overview:
5209 ============================
5211 go - start application at address 'addr'
5212 run - run commands in an environment variable
5213 bootm - boot application image from memory
5214 bootp - boot image via network using BootP/TFTP protocol
5215 bootz - boot zImage from memory
5216 tftpboot- boot image via network using TFTP protocol
5217 and env variables "ipaddr" and "serverip"
5218 (and eventually "gatewayip")
5219 tftpput - upload a file via network using TFTP protocol
5220 rarpboot- boot image via network using RARP/TFTP protocol
5221 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5222 loads - load S-Record file over serial line
5223 loadb - load binary file over serial line (kermit mode)
5225 mm - memory modify (auto-incrementing)
5226 nm - memory modify (constant address)
5227 mw - memory write (fill)
5229 cmp - memory compare
5230 crc32 - checksum calculation
5231 i2c - I2C sub-system
5232 sspi - SPI utility commands
5233 base - print or set address offset
5234 printenv- print environment variables
5235 setenv - set environment variables
5236 saveenv - save environment variables to persistent storage
5237 protect - enable or disable FLASH write protection
5238 erase - erase FLASH memory
5239 flinfo - print FLASH memory information
5240 nand - NAND memory operations (see doc/README.nand)
5241 bdinfo - print Board Info structure
5242 iminfo - print header information for application image
5243 coninfo - print console devices and informations
5244 ide - IDE sub-system
5245 loop - infinite loop on address range
5246 loopw - infinite write loop on address range
5247 mtest - simple RAM test
5248 icache - enable or disable instruction cache
5249 dcache - enable or disable data cache
5250 reset - Perform RESET of the CPU
5251 echo - echo args to console
5252 version - print monitor version
5253 help - print online help
5254 ? - alias for 'help'
5257 Monitor Commands - Detailed Description:
5258 ========================================
5262 For now: just type "help <command>".
5265 Environment Variables:
5266 ======================
5268 U-Boot supports user configuration using Environment Variables which
5269 can be made persistent by saving to Flash memory.
5271 Environment Variables are set using "setenv", printed using
5272 "printenv", and saved to Flash using "saveenv". Using "setenv"
5273 without a value can be used to delete a variable from the
5274 environment. As long as you don't save the environment you are
5275 working with an in-memory copy. In case the Flash area containing the
5276 environment is erased by accident, a default environment is provided.
5278 Some configuration options can be set using Environment Variables.
5280 List of environment variables (most likely not complete):
5282 baudrate - see CONFIG_BAUDRATE
5284 bootdelay - see CONFIG_BOOTDELAY
5286 bootcmd - see CONFIG_BOOTCOMMAND
5288 bootargs - Boot arguments when booting an RTOS image
5290 bootfile - Name of the image to load with TFTP
5292 bootm_low - Memory range available for image processing in the bootm
5293 command can be restricted. This variable is given as
5294 a hexadecimal number and defines lowest address allowed
5295 for use by the bootm command. See also "bootm_size"
5296 environment variable. Address defined by "bootm_low" is
5297 also the base of the initial memory mapping for the Linux
5298 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5301 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5302 This variable is given as a hexadecimal number and it
5303 defines the size of the memory region starting at base
5304 address bootm_low that is accessible by the Linux kernel
5305 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5306 as the default value if it is defined, and bootm_size is
5309 bootm_size - Memory range available for image processing in the bootm
5310 command can be restricted. This variable is given as
5311 a hexadecimal number and defines the size of the region
5312 allowed for use by the bootm command. See also "bootm_low"
5313 environment variable.
5315 updatefile - Location of the software update file on a TFTP server, used
5316 by the automatic software update feature. Please refer to
5317 documentation in doc/README.update for more details.
5319 autoload - if set to "no" (any string beginning with 'n'),
5320 "bootp" will just load perform a lookup of the
5321 configuration from the BOOTP server, but not try to
5322 load any image using TFTP
5324 autostart - if set to "yes", an image loaded using the "bootp",
5325 "rarpboot", "tftpboot" or "diskboot" commands will
5326 be automatically started (by internally calling
5329 If set to "no", a standalone image passed to the
5330 "bootm" command will be copied to the load address
5331 (and eventually uncompressed), but NOT be started.
5332 This can be used to load and uncompress arbitrary
5335 fdt_high - if set this restricts the maximum address that the
5336 flattened device tree will be copied into upon boot.
5337 For example, if you have a system with 1 GB memory
5338 at physical address 0x10000000, while Linux kernel
5339 only recognizes the first 704 MB as low memory, you
5340 may need to set fdt_high as 0x3C000000 to have the
5341 device tree blob be copied to the maximum address
5342 of the 704 MB low memory, so that Linux kernel can
5343 access it during the boot procedure.
5345 If this is set to the special value 0xFFFFFFFF then
5346 the fdt will not be copied at all on boot. For this
5347 to work it must reside in writable memory, have
5348 sufficient padding on the end of it for u-boot to
5349 add the information it needs into it, and the memory
5350 must be accessible by the kernel.
5352 fdtcontroladdr- if set this is the address of the control flattened
5353 device tree used by U-Boot when CONFIG_OF_CONTROL is
5356 i2cfast - (PPC405GP|PPC405EP only)
5357 if set to 'y' configures Linux I2C driver for fast
5358 mode (400kHZ). This environment variable is used in
5359 initialization code. So, for changes to be effective
5360 it must be saved and board must be reset.
5362 initrd_high - restrict positioning of initrd images:
5363 If this variable is not set, initrd images will be
5364 copied to the highest possible address in RAM; this
5365 is usually what you want since it allows for
5366 maximum initrd size. If for some reason you want to
5367 make sure that the initrd image is loaded below the
5368 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5369 variable to a value of "no" or "off" or "0".
5370 Alternatively, you can set it to a maximum upper
5371 address to use (U-Boot will still check that it
5372 does not overwrite the U-Boot stack and data).
5374 For instance, when you have a system with 16 MB
5375 RAM, and want to reserve 4 MB from use by Linux,
5376 you can do this by adding "mem=12M" to the value of
5377 the "bootargs" variable. However, now you must make
5378 sure that the initrd image is placed in the first
5379 12 MB as well - this can be done with
5381 setenv initrd_high 00c00000
5383 If you set initrd_high to 0xFFFFFFFF, this is an
5384 indication to U-Boot that all addresses are legal
5385 for the Linux kernel, including addresses in flash
5386 memory. In this case U-Boot will NOT COPY the
5387 ramdisk at all. This may be useful to reduce the
5388 boot time on your system, but requires that this
5389 feature is supported by your Linux kernel.
5391 ipaddr - IP address; needed for tftpboot command
5393 loadaddr - Default load address for commands like "bootp",
5394 "rarpboot", "tftpboot", "loadb" or "diskboot"
5396 loads_echo - see CONFIG_LOADS_ECHO
5398 serverip - TFTP server IP address; needed for tftpboot command
5400 bootretry - see CONFIG_BOOT_RETRY_TIME
5402 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5404 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5406 ethprime - controls which interface is used first.
5408 ethact - controls which interface is currently active.
5409 For example you can do the following
5411 => setenv ethact FEC
5412 => ping 192.168.0.1 # traffic sent on FEC
5413 => setenv ethact SCC
5414 => ping 10.0.0.1 # traffic sent on SCC
5416 ethrotate - When set to "no" U-Boot does not go through all
5417 available network interfaces.
5418 It just stays at the currently selected interface.
5420 netretry - When set to "no" each network operation will
5421 either succeed or fail without retrying.
5422 When set to "once" the network operation will
5423 fail when all the available network interfaces
5424 are tried once without success.
5425 Useful on scripts which control the retry operation
5428 npe_ucode - set load address for the NPE microcode
5430 silent_linux - If set then linux will be told to boot silently, by
5431 changing the console to be empty. If "yes" it will be
5432 made silent. If "no" it will not be made silent. If
5433 unset, then it will be made silent if the U-Boot console
5436 tftpsrcport - If this is set, the value is used for TFTP's
5439 tftpdstport - If this is set, the value is used for TFTP's UDP
5440 destination port instead of the Well Know Port 69.
5442 tftpblocksize - Block size to use for TFTP transfers; if not set,
5443 we use the TFTP server's default block size
5445 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5446 seconds, minimum value is 1000 = 1 second). Defines
5447 when a packet is considered to be lost so it has to
5448 be retransmitted. The default is 5000 = 5 seconds.
5449 Lowering this value may make downloads succeed
5450 faster in networks with high packet loss rates or
5451 with unreliable TFTP servers.
5453 vlan - When set to a value < 4095 the traffic over
5454 Ethernet is encapsulated/received over 802.1q
5457 The following image location variables contain the location of images
5458 used in booting. The "Image" column gives the role of the image and is
5459 not an environment variable name. The other columns are environment
5460 variable names. "File Name" gives the name of the file on a TFTP
5461 server, "RAM Address" gives the location in RAM the image will be
5462 loaded to, and "Flash Location" gives the image's address in NOR
5463 flash or offset in NAND flash.
5465 *Note* - these variables don't have to be defined for all boards, some
5466 boards currenlty use other variables for these purposes, and some
5467 boards use these variables for other purposes.
5469 Image File Name RAM Address Flash Location
5470 ----- --------- ----------- --------------
5471 u-boot u-boot u-boot_addr_r u-boot_addr
5472 Linux kernel bootfile kernel_addr_r kernel_addr
5473 device tree blob fdtfile fdt_addr_r fdt_addr
5474 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5476 The following environment variables may be used and automatically
5477 updated by the network boot commands ("bootp" and "rarpboot"),
5478 depending the information provided by your boot server:
5480 bootfile - see above
5481 dnsip - IP address of your Domain Name Server
5482 dnsip2 - IP address of your secondary Domain Name Server
5483 gatewayip - IP address of the Gateway (Router) to use
5484 hostname - Target hostname
5486 netmask - Subnet Mask
5487 rootpath - Pathname of the root filesystem on the NFS server
5488 serverip - see above
5491 There are two special Environment Variables:
5493 serial# - contains hardware identification information such
5494 as type string and/or serial number
5495 ethaddr - Ethernet address
5497 These variables can be set only once (usually during manufacturing of
5498 the board). U-Boot refuses to delete or overwrite these variables
5499 once they have been set once.
5502 Further special Environment Variables:
5504 ver - Contains the U-Boot version string as printed
5505 with the "version" command. This variable is
5506 readonly (see CONFIG_VERSION_VARIABLE).
5509 Please note that changes to some configuration parameters may take
5510 only effect after the next boot (yes, that's just like Windoze :-).
5513 Callback functions for environment variables:
5514 ---------------------------------------------
5516 For some environment variables, the behavior of u-boot needs to change
5517 when their values are changed. This functionailty allows functions to
5518 be associated with arbitrary variables. On creation, overwrite, or
5519 deletion, the callback will provide the opportunity for some side
5520 effect to happen or for the change to be rejected.
5522 The callbacks are named and associated with a function using the
5523 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5525 These callbacks are associated with variables in one of two ways. The
5526 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5527 in the board configuration to a string that defines a list of
5528 associations. The list must be in the following format:
5530 entry = variable_name[:callback_name]
5533 If the callback name is not specified, then the callback is deleted.
5534 Spaces are also allowed anywhere in the list.
5536 Callbacks can also be associated by defining the ".callbacks" variable
5537 with the same list format above. Any association in ".callbacks" will
5538 override any association in the static list. You can define
5539 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5540 ".callbacks" envirnoment variable in the default or embedded environment.
5543 Command Line Parsing:
5544 =====================
5546 There are two different command line parsers available with U-Boot:
5547 the old "simple" one, and the much more powerful "hush" shell:
5549 Old, simple command line parser:
5550 --------------------------------
5552 - supports environment variables (through setenv / saveenv commands)
5553 - several commands on one line, separated by ';'
5554 - variable substitution using "... ${name} ..." syntax
5555 - special characters ('$', ';') can be escaped by prefixing with '\',
5557 setenv bootcmd bootm \${address}
5558 - You can also escape text by enclosing in single apostrophes, for example:
5559 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5564 - similar to Bourne shell, with control structures like
5565 if...then...else...fi, for...do...done; while...do...done,
5566 until...do...done, ...
5567 - supports environment ("global") variables (through setenv / saveenv
5568 commands) and local shell variables (through standard shell syntax
5569 "name=value"); only environment variables can be used with "run"
5575 (1) If a command line (or an environment variable executed by a "run"
5576 command) contains several commands separated by semicolon, and
5577 one of these commands fails, then the remaining commands will be
5580 (2) If you execute several variables with one call to run (i. e.
5581 calling run with a list of variables as arguments), any failing
5582 command will cause "run" to terminate, i. e. the remaining
5583 variables are not executed.
5585 Note for Redundant Ethernet Interfaces:
5586 =======================================
5588 Some boards come with redundant Ethernet interfaces; U-Boot supports
5589 such configurations and is capable of automatic selection of a
5590 "working" interface when needed. MAC assignment works as follows:
5592 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5593 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5594 "eth1addr" (=>eth1), "eth2addr", ...
5596 If the network interface stores some valid MAC address (for instance
5597 in SROM), this is used as default address if there is NO correspon-
5598 ding setting in the environment; if the corresponding environment
5599 variable is set, this overrides the settings in the card; that means:
5601 o If the SROM has a valid MAC address, and there is no address in the
5602 environment, the SROM's address is used.
5604 o If there is no valid address in the SROM, and a definition in the
5605 environment exists, then the value from the environment variable is
5608 o If both the SROM and the environment contain a MAC address, and
5609 both addresses are the same, this MAC address is used.
5611 o If both the SROM and the environment contain a MAC address, and the
5612 addresses differ, the value from the environment is used and a
5615 o If neither SROM nor the environment contain a MAC address, an error
5618 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5619 will be programmed into hardware as part of the initialization process. This
5620 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5621 The naming convention is as follows:
5622 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5627 U-Boot is capable of booting (and performing other auxiliary operations on)
5628 images in two formats:
5630 New uImage format (FIT)
5631 -----------------------
5633 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5634 to Flattened Device Tree). It allows the use of images with multiple
5635 components (several kernels, ramdisks, etc.), with contents protected by
5636 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5642 Old image format is based on binary files which can be basically anything,
5643 preceded by a special header; see the definitions in include/image.h for
5644 details; basically, the header defines the following image properties:
5646 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5647 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5648 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5649 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5651 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5652 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5653 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5654 * Compression Type (uncompressed, gzip, bzip2)
5660 The header is marked by a special Magic Number, and both the header
5661 and the data portions of the image are secured against corruption by
5668 Although U-Boot should support any OS or standalone application
5669 easily, the main focus has always been on Linux during the design of
5672 U-Boot includes many features that so far have been part of some
5673 special "boot loader" code within the Linux kernel. Also, any
5674 "initrd" images to be used are no longer part of one big Linux image;
5675 instead, kernel and "initrd" are separate images. This implementation
5676 serves several purposes:
5678 - the same features can be used for other OS or standalone
5679 applications (for instance: using compressed images to reduce the
5680 Flash memory footprint)
5682 - it becomes much easier to port new Linux kernel versions because
5683 lots of low-level, hardware dependent stuff are done by U-Boot
5685 - the same Linux kernel image can now be used with different "initrd"
5686 images; of course this also means that different kernel images can
5687 be run with the same "initrd". This makes testing easier (you don't
5688 have to build a new "zImage.initrd" Linux image when you just
5689 change a file in your "initrd"). Also, a field-upgrade of the
5690 software is easier now.
5696 Porting Linux to U-Boot based systems:
5697 ---------------------------------------
5699 U-Boot cannot save you from doing all the necessary modifications to
5700 configure the Linux device drivers for use with your target hardware
5701 (no, we don't intend to provide a full virtual machine interface to
5704 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5706 Just make sure your machine specific header file (for instance
5707 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5708 Information structure as we define in include/asm-<arch>/u-boot.h,
5709 and make sure that your definition of IMAP_ADDR uses the same value
5710 as your U-Boot configuration in CONFIG_SYS_IMMR.
5712 Note that U-Boot now has a driver model, a unified model for drivers.
5713 If you are adding a new driver, plumb it into driver model. If there
5714 is no uclass available, you are encouraged to create one. See
5718 Configuring the Linux kernel:
5719 -----------------------------
5721 No specific requirements for U-Boot. Make sure you have some root
5722 device (initial ramdisk, NFS) for your target system.
5725 Building a Linux Image:
5726 -----------------------
5728 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5729 not used. If you use recent kernel source, a new build target
5730 "uImage" will exist which automatically builds an image usable by
5731 U-Boot. Most older kernels also have support for a "pImage" target,
5732 which was introduced for our predecessor project PPCBoot and uses a
5733 100% compatible format.
5737 make TQM850L_defconfig
5742 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5743 encapsulate a compressed Linux kernel image with header information,
5744 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5746 * build a standard "vmlinux" kernel image (in ELF binary format):
5748 * convert the kernel into a raw binary image:
5750 ${CROSS_COMPILE}-objcopy -O binary \
5751 -R .note -R .comment \
5752 -S vmlinux linux.bin
5754 * compress the binary image:
5758 * package compressed binary image for U-Boot:
5760 mkimage -A ppc -O linux -T kernel -C gzip \
5761 -a 0 -e 0 -n "Linux Kernel Image" \
5762 -d linux.bin.gz uImage
5765 The "mkimage" tool can also be used to create ramdisk images for use
5766 with U-Boot, either separated from the Linux kernel image, or
5767 combined into one file. "mkimage" encapsulates the images with a 64
5768 byte header containing information about target architecture,
5769 operating system, image type, compression method, entry points, time
5770 stamp, CRC32 checksums, etc.
5772 "mkimage" can be called in two ways: to verify existing images and
5773 print the header information, or to build new images.
5775 In the first form (with "-l" option) mkimage lists the information
5776 contained in the header of an existing U-Boot image; this includes
5777 checksum verification:
5779 tools/mkimage -l image
5780 -l ==> list image header information
5782 The second form (with "-d" option) is used to build a U-Boot image
5783 from a "data file" which is used as image payload:
5785 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5786 -n name -d data_file image
5787 -A ==> set architecture to 'arch'
5788 -O ==> set operating system to 'os'
5789 -T ==> set image type to 'type'
5790 -C ==> set compression type 'comp'
5791 -a ==> set load address to 'addr' (hex)
5792 -e ==> set entry point to 'ep' (hex)
5793 -n ==> set image name to 'name'
5794 -d ==> use image data from 'datafile'
5796 Right now, all Linux kernels for PowerPC systems use the same load
5797 address (0x00000000), but the entry point address depends on the
5800 - 2.2.x kernels have the entry point at 0x0000000C,
5801 - 2.3.x and later kernels have the entry point at 0x00000000.
5803 So a typical call to build a U-Boot image would read:
5805 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5806 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5807 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5808 > examples/uImage.TQM850L
5809 Image Name: 2.4.4 kernel for TQM850L
5810 Created: Wed Jul 19 02:34:59 2000
5811 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5812 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5813 Load Address: 0x00000000
5814 Entry Point: 0x00000000
5816 To verify the contents of the image (or check for corruption):
5818 -> tools/mkimage -l examples/uImage.TQM850L
5819 Image Name: 2.4.4 kernel for TQM850L
5820 Created: Wed Jul 19 02:34:59 2000
5821 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5822 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5823 Load Address: 0x00000000
5824 Entry Point: 0x00000000
5826 NOTE: for embedded systems where boot time is critical you can trade
5827 speed for memory and install an UNCOMPRESSED image instead: this
5828 needs more space in Flash, but boots much faster since it does not
5829 need to be uncompressed:
5831 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5832 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5833 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5834 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5835 > examples/uImage.TQM850L-uncompressed
5836 Image Name: 2.4.4 kernel for TQM850L
5837 Created: Wed Jul 19 02:34:59 2000
5838 Image Type: PowerPC Linux Kernel Image (uncompressed)
5839 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5840 Load Address: 0x00000000
5841 Entry Point: 0x00000000
5844 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5845 when your kernel is intended to use an initial ramdisk:
5847 -> tools/mkimage -n 'Simple Ramdisk Image' \
5848 > -A ppc -O linux -T ramdisk -C gzip \
5849 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5850 Image Name: Simple Ramdisk Image
5851 Created: Wed Jan 12 14:01:50 2000
5852 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5853 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5854 Load Address: 0x00000000
5855 Entry Point: 0x00000000
5857 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5858 option performs the converse operation of the mkimage's second form (the "-d"
5859 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5862 tools/dumpimage -i image -p position data_file
5863 -i ==> extract from the 'image' a specific 'data_file', \
5864 indexed by 'position'
5867 Installing a Linux Image:
5868 -------------------------
5870 To downloading a U-Boot image over the serial (console) interface,
5871 you must convert the image to S-Record format:
5873 objcopy -I binary -O srec examples/image examples/image.srec
5875 The 'objcopy' does not understand the information in the U-Boot
5876 image header, so the resulting S-Record file will be relative to
5877 address 0x00000000. To load it to a given address, you need to
5878 specify the target address as 'offset' parameter with the 'loads'
5881 Example: install the image to address 0x40100000 (which on the
5882 TQM8xxL is in the first Flash bank):
5884 => erase 40100000 401FFFFF
5890 ## Ready for S-Record download ...
5891 ~>examples/image.srec
5892 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5894 15989 15990 15991 15992
5895 [file transfer complete]
5897 ## Start Addr = 0x00000000
5900 You can check the success of the download using the 'iminfo' command;
5901 this includes a checksum verification so you can be sure no data
5902 corruption happened:
5906 ## Checking Image at 40100000 ...
5907 Image Name: 2.2.13 for initrd on TQM850L
5908 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5909 Data Size: 335725 Bytes = 327 kB = 0 MB
5910 Load Address: 00000000
5911 Entry Point: 0000000c
5912 Verifying Checksum ... OK
5918 The "bootm" command is used to boot an application that is stored in
5919 memory (RAM or Flash). In case of a Linux kernel image, the contents
5920 of the "bootargs" environment variable is passed to the kernel as
5921 parameters. You can check and modify this variable using the
5922 "printenv" and "setenv" commands:
5925 => printenv bootargs
5926 bootargs=root=/dev/ram
5928 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5930 => printenv bootargs
5931 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5934 ## Booting Linux kernel at 40020000 ...
5935 Image Name: 2.2.13 for NFS on TQM850L
5936 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5937 Data Size: 381681 Bytes = 372 kB = 0 MB
5938 Load Address: 00000000
5939 Entry Point: 0000000c
5940 Verifying Checksum ... OK
5941 Uncompressing Kernel Image ... OK
5942 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5943 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5944 time_init: decrementer frequency = 187500000/60
5945 Calibrating delay loop... 49.77 BogoMIPS
5946 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5949 If you want to boot a Linux kernel with initial RAM disk, you pass
5950 the memory addresses of both the kernel and the initrd image (PPBCOOT
5951 format!) to the "bootm" command:
5953 => imi 40100000 40200000
5955 ## Checking Image at 40100000 ...
5956 Image Name: 2.2.13 for initrd on TQM850L
5957 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5958 Data Size: 335725 Bytes = 327 kB = 0 MB
5959 Load Address: 00000000
5960 Entry Point: 0000000c
5961 Verifying Checksum ... OK
5963 ## Checking Image at 40200000 ...
5964 Image Name: Simple Ramdisk Image
5965 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5966 Data Size: 566530 Bytes = 553 kB = 0 MB
5967 Load Address: 00000000
5968 Entry Point: 00000000
5969 Verifying Checksum ... OK
5971 => bootm 40100000 40200000
5972 ## Booting Linux kernel at 40100000 ...
5973 Image Name: 2.2.13 for initrd on TQM850L
5974 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5975 Data Size: 335725 Bytes = 327 kB = 0 MB
5976 Load Address: 00000000
5977 Entry Point: 0000000c
5978 Verifying Checksum ... OK
5979 Uncompressing Kernel Image ... OK
5980 ## Loading RAMDisk Image at 40200000 ...
5981 Image Name: Simple Ramdisk Image
5982 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5983 Data Size: 566530 Bytes = 553 kB = 0 MB
5984 Load Address: 00000000
5985 Entry Point: 00000000
5986 Verifying Checksum ... OK
5987 Loading Ramdisk ... OK
5988 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5989 Boot arguments: root=/dev/ram
5990 time_init: decrementer frequency = 187500000/60
5991 Calibrating delay loop... 49.77 BogoMIPS
5993 RAMDISK: Compressed image found at block 0
5994 VFS: Mounted root (ext2 filesystem).
5998 Boot Linux and pass a flat device tree:
6001 First, U-Boot must be compiled with the appropriate defines. See the section
6002 titled "Linux Kernel Interface" above for a more in depth explanation. The
6003 following is an example of how to start a kernel and pass an updated
6009 oft=oftrees/mpc8540ads.dtb
6010 => tftp $oftaddr $oft
6011 Speed: 1000, full duplex
6013 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6014 Filename 'oftrees/mpc8540ads.dtb'.
6015 Load address: 0x300000
6018 Bytes transferred = 4106 (100a hex)
6019 => tftp $loadaddr $bootfile
6020 Speed: 1000, full duplex
6022 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6024 Load address: 0x200000
6025 Loading:############
6027 Bytes transferred = 1029407 (fb51f hex)
6032 => bootm $loadaddr - $oftaddr
6033 ## Booting image at 00200000 ...
6034 Image Name: Linux-2.6.17-dirty
6035 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6036 Data Size: 1029343 Bytes = 1005.2 kB
6037 Load Address: 00000000
6038 Entry Point: 00000000
6039 Verifying Checksum ... OK
6040 Uncompressing Kernel Image ... OK
6041 Booting using flat device tree at 0x300000
6042 Using MPC85xx ADS machine description
6043 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6047 More About U-Boot Image Types:
6048 ------------------------------
6050 U-Boot supports the following image types:
6052 "Standalone Programs" are directly runnable in the environment
6053 provided by U-Boot; it is expected that (if they behave
6054 well) you can continue to work in U-Boot after return from
6055 the Standalone Program.
6056 "OS Kernel Images" are usually images of some Embedded OS which
6057 will take over control completely. Usually these programs
6058 will install their own set of exception handlers, device
6059 drivers, set up the MMU, etc. - this means, that you cannot
6060 expect to re-enter U-Boot except by resetting the CPU.
6061 "RAMDisk Images" are more or less just data blocks, and their
6062 parameters (address, size) are passed to an OS kernel that is
6064 "Multi-File Images" contain several images, typically an OS
6065 (Linux) kernel image and one or more data images like
6066 RAMDisks. This construct is useful for instance when you want
6067 to boot over the network using BOOTP etc., where the boot
6068 server provides just a single image file, but you want to get
6069 for instance an OS kernel and a RAMDisk image.
6071 "Multi-File Images" start with a list of image sizes, each
6072 image size (in bytes) specified by an "uint32_t" in network
6073 byte order. This list is terminated by an "(uint32_t)0".
6074 Immediately after the terminating 0 follow the images, one by
6075 one, all aligned on "uint32_t" boundaries (size rounded up to
6076 a multiple of 4 bytes).
6078 "Firmware Images" are binary images containing firmware (like
6079 U-Boot or FPGA images) which usually will be programmed to
6082 "Script files" are command sequences that will be executed by
6083 U-Boot's command interpreter; this feature is especially
6084 useful when you configure U-Boot to use a real shell (hush)
6085 as command interpreter.
6087 Booting the Linux zImage:
6088 -------------------------
6090 On some platforms, it's possible to boot Linux zImage. This is done
6091 using the "bootz" command. The syntax of "bootz" command is the same
6092 as the syntax of "bootm" command.
6094 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6095 kernel with raw initrd images. The syntax is slightly different, the
6096 address of the initrd must be augmented by it's size, in the following
6097 format: "<initrd addres>:<initrd size>".
6103 One of the features of U-Boot is that you can dynamically load and
6104 run "standalone" applications, which can use some resources of
6105 U-Boot like console I/O functions or interrupt services.
6107 Two simple examples are included with the sources:
6112 'examples/hello_world.c' contains a small "Hello World" Demo
6113 application; it is automatically compiled when you build U-Boot.
6114 It's configured to run at address 0x00040004, so you can play with it
6118 ## Ready for S-Record download ...
6119 ~>examples/hello_world.srec
6120 1 2 3 4 5 6 7 8 9 10 11 ...
6121 [file transfer complete]
6123 ## Start Addr = 0x00040004
6125 => go 40004 Hello World! This is a test.
6126 ## Starting application at 0x00040004 ...
6137 Hit any key to exit ...
6139 ## Application terminated, rc = 0x0
6141 Another example, which demonstrates how to register a CPM interrupt
6142 handler with the U-Boot code, can be found in 'examples/timer.c'.
6143 Here, a CPM timer is set up to generate an interrupt every second.
6144 The interrupt service routine is trivial, just printing a '.'
6145 character, but this is just a demo program. The application can be
6146 controlled by the following keys:
6148 ? - print current values og the CPM Timer registers
6149 b - enable interrupts and start timer
6150 e - stop timer and disable interrupts
6151 q - quit application
6154 ## Ready for S-Record download ...
6155 ~>examples/timer.srec
6156 1 2 3 4 5 6 7 8 9 10 11 ...
6157 [file transfer complete]
6159 ## Start Addr = 0x00040004
6162 ## Starting application at 0x00040004 ...
6165 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6168 [q, b, e, ?] Set interval 1000000 us
6171 [q, b, e, ?] ........
6172 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6175 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6178 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6181 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6183 [q, b, e, ?] ...Stopping timer
6185 [q, b, e, ?] ## Application terminated, rc = 0x0
6191 Over time, many people have reported problems when trying to use the
6192 "minicom" terminal emulation program for serial download. I (wd)
6193 consider minicom to be broken, and recommend not to use it. Under
6194 Unix, I recommend to use C-Kermit for general purpose use (and
6195 especially for kermit binary protocol download ("loadb" command), and
6196 use "cu" for S-Record download ("loads" command). See
6197 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6198 for help with kermit.
6201 Nevertheless, if you absolutely want to use it try adding this
6202 configuration to your "File transfer protocols" section:
6204 Name Program Name U/D FullScr IO-Red. Multi
6205 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6206 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6212 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6213 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6215 Building requires a cross environment; it is known to work on
6216 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6217 need gmake since the Makefiles are not compatible with BSD make).
6218 Note that the cross-powerpc package does not install include files;
6219 attempting to build U-Boot will fail because <machine/ansi.h> is
6220 missing. This file has to be installed and patched manually:
6222 # cd /usr/pkg/cross/powerpc-netbsd/include
6224 # ln -s powerpc machine
6225 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6226 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6228 Native builds *don't* work due to incompatibilities between native
6229 and U-Boot include files.
6231 Booting assumes that (the first part of) the image booted is a
6232 stage-2 loader which in turn loads and then invokes the kernel
6233 proper. Loader sources will eventually appear in the NetBSD source
6234 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6235 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6238 Implementation Internals:
6239 =========================
6241 The following is not intended to be a complete description of every
6242 implementation detail. However, it should help to understand the
6243 inner workings of U-Boot and make it easier to port it to custom
6247 Initial Stack, Global Data:
6248 ---------------------------
6250 The implementation of U-Boot is complicated by the fact that U-Boot
6251 starts running out of ROM (flash memory), usually without access to
6252 system RAM (because the memory controller is not initialized yet).
6253 This means that we don't have writable Data or BSS segments, and BSS
6254 is not initialized as zero. To be able to get a C environment working
6255 at all, we have to allocate at least a minimal stack. Implementation
6256 options for this are defined and restricted by the CPU used: Some CPU
6257 models provide on-chip memory (like the IMMR area on MPC8xx and
6258 MPC826x processors), on others (parts of) the data cache can be
6259 locked as (mis-) used as memory, etc.
6261 Chris Hallinan posted a good summary of these issues to the
6262 U-Boot mailing list:
6264 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6266 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6269 Correct me if I'm wrong, folks, but the way I understand it
6270 is this: Using DCACHE as initial RAM for Stack, etc, does not
6271 require any physical RAM backing up the cache. The cleverness
6272 is that the cache is being used as a temporary supply of
6273 necessary storage before the SDRAM controller is setup. It's
6274 beyond the scope of this list to explain the details, but you
6275 can see how this works by studying the cache architecture and
6276 operation in the architecture and processor-specific manuals.
6278 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6279 is another option for the system designer to use as an
6280 initial stack/RAM area prior to SDRAM being available. Either
6281 option should work for you. Using CS 4 should be fine if your
6282 board designers haven't used it for something that would
6283 cause you grief during the initial boot! It is frequently not
6286 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6287 with your processor/board/system design. The default value
6288 you will find in any recent u-boot distribution in
6289 walnut.h should work for you. I'd set it to a value larger
6290 than your SDRAM module. If you have a 64MB SDRAM module, set
6291 it above 400_0000. Just make sure your board has no resources
6292 that are supposed to respond to that address! That code in
6293 start.S has been around a while and should work as is when
6294 you get the config right.
6299 It is essential to remember this, since it has some impact on the C
6300 code for the initialization procedures:
6302 * Initialized global data (data segment) is read-only. Do not attempt
6305 * Do not use any uninitialized global data (or implicitely initialized
6306 as zero data - BSS segment) at all - this is undefined, initiali-
6307 zation is performed later (when relocating to RAM).
6309 * Stack space is very limited. Avoid big data buffers or things like
6312 Having only the stack as writable memory limits means we cannot use
6313 normal global data to share information beween the code. But it
6314 turned out that the implementation of U-Boot can be greatly
6315 simplified by making a global data structure (gd_t) available to all
6316 functions. We could pass a pointer to this data as argument to _all_
6317 functions, but this would bloat the code. Instead we use a feature of
6318 the GCC compiler (Global Register Variables) to share the data: we
6319 place a pointer (gd) to the global data into a register which we
6320 reserve for this purpose.
6322 When choosing a register for such a purpose we are restricted by the
6323 relevant (E)ABI specifications for the current architecture, and by
6324 GCC's implementation.
6326 For PowerPC, the following registers have specific use:
6328 R2: reserved for system use
6329 R3-R4: parameter passing and return values
6330 R5-R10: parameter passing
6331 R13: small data area pointer
6335 (U-Boot also uses R12 as internal GOT pointer. r12
6336 is a volatile register so r12 needs to be reset when
6337 going back and forth between asm and C)
6339 ==> U-Boot will use R2 to hold a pointer to the global data
6341 Note: on PPC, we could use a static initializer (since the
6342 address of the global data structure is known at compile time),
6343 but it turned out that reserving a register results in somewhat
6344 smaller code - although the code savings are not that big (on
6345 average for all boards 752 bytes for the whole U-Boot image,
6346 624 text + 127 data).
6348 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6349 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6351 ==> U-Boot will use P3 to hold a pointer to the global data
6353 On ARM, the following registers are used:
6355 R0: function argument word/integer result
6356 R1-R3: function argument word
6357 R9: platform specific
6358 R10: stack limit (used only if stack checking is enabled)
6359 R11: argument (frame) pointer
6360 R12: temporary workspace
6363 R15: program counter
6365 ==> U-Boot will use R9 to hold a pointer to the global data
6367 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6369 On Nios II, the ABI is documented here:
6370 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6372 ==> U-Boot will use gp to hold a pointer to the global data
6374 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6375 to access small data sections, so gp is free.
6377 On NDS32, the following registers are used:
6379 R0-R1: argument/return
6381 R15: temporary register for assembler
6382 R16: trampoline register
6383 R28: frame pointer (FP)
6384 R29: global pointer (GP)
6385 R30: link register (LP)
6386 R31: stack pointer (SP)
6387 PC: program counter (PC)
6389 ==> U-Boot will use R10 to hold a pointer to the global data
6391 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6392 or current versions of GCC may "optimize" the code too much.
6397 U-Boot runs in system state and uses physical addresses, i.e. the
6398 MMU is not used either for address mapping nor for memory protection.
6400 The available memory is mapped to fixed addresses using the memory
6401 controller. In this process, a contiguous block is formed for each
6402 memory type (Flash, SDRAM, SRAM), even when it consists of several
6403 physical memory banks.
6405 U-Boot is installed in the first 128 kB of the first Flash bank (on
6406 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6407 booting and sizing and initializing DRAM, the code relocates itself
6408 to the upper end of DRAM. Immediately below the U-Boot code some
6409 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6410 configuration setting]. Below that, a structure with global Board
6411 Info data is placed, followed by the stack (growing downward).
6413 Additionally, some exception handler code is copied to the low 8 kB
6414 of DRAM (0x00000000 ... 0x00001FFF).
6416 So a typical memory configuration with 16 MB of DRAM could look like
6419 0x0000 0000 Exception Vector code
6422 0x0000 2000 Free for Application Use
6428 0x00FB FF20 Monitor Stack (Growing downward)
6429 0x00FB FFAC Board Info Data and permanent copy of global data
6430 0x00FC 0000 Malloc Arena
6433 0x00FE 0000 RAM Copy of Monitor Code
6434 ... eventually: LCD or video framebuffer
6435 ... eventually: pRAM (Protected RAM - unchanged by reset)
6436 0x00FF FFFF [End of RAM]
6439 System Initialization:
6440 ----------------------
6442 In the reset configuration, U-Boot starts at the reset entry point
6443 (on most PowerPC systems at address 0x00000100). Because of the reset
6444 configuration for CS0# this is a mirror of the onboard Flash memory.
6445 To be able to re-map memory U-Boot then jumps to its link address.
6446 To be able to implement the initialization code in C, a (small!)
6447 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6448 which provide such a feature like MPC8xx or MPC8260), or in a locked
6449 part of the data cache. After that, U-Boot initializes the CPU core,
6450 the caches and the SIU.
6452 Next, all (potentially) available memory banks are mapped using a
6453 preliminary mapping. For example, we put them on 512 MB boundaries
6454 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6455 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6456 programmed for SDRAM access. Using the temporary configuration, a
6457 simple memory test is run that determines the size of the SDRAM
6460 When there is more than one SDRAM bank, and the banks are of
6461 different size, the largest is mapped first. For equal size, the first
6462 bank (CS2#) is mapped first. The first mapping is always for address
6463 0x00000000, with any additional banks following immediately to create
6464 contiguous memory starting from 0.
6466 Then, the monitor installs itself at the upper end of the SDRAM area
6467 and allocates memory for use by malloc() and for the global Board
6468 Info data; also, the exception vector code is copied to the low RAM
6469 pages, and the final stack is set up.
6471 Only after this relocation will you have a "normal" C environment;
6472 until that you are restricted in several ways, mostly because you are
6473 running from ROM, and because the code will have to be relocated to a
6477 U-Boot Porting Guide:
6478 ----------------------
6480 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6484 int main(int argc, char *argv[])
6486 sighandler_t no_more_time;
6488 signal(SIGALRM, no_more_time);
6489 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6491 if (available_money > available_manpower) {
6492 Pay consultant to port U-Boot;
6496 Download latest U-Boot source;
6498 Subscribe to u-boot mailing list;
6501 email("Hi, I am new to U-Boot, how do I get started?");
6504 Read the README file in the top level directory;
6505 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6506 Read applicable doc/*.README;
6507 Read the source, Luke;
6508 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6511 if (available_money > toLocalCurrency ($2500))
6514 Add a lot of aggravation and time;
6516 if (a similar board exists) { /* hopefully... */
6517 cp -a board/<similar> board/<myboard>
6518 cp include/configs/<similar>.h include/configs/<myboard>.h
6520 Create your own board support subdirectory;
6521 Create your own board include/configs/<myboard>.h file;
6523 Edit new board/<myboard> files
6524 Edit new include/configs/<myboard>.h
6529 Add / modify source code;
6533 email("Hi, I am having problems...");
6535 Send patch file to the U-Boot email list;
6536 if (reasonable critiques)
6537 Incorporate improvements from email list code review;
6539 Defend code as written;
6545 void no_more_time (int sig)
6554 All contributions to U-Boot should conform to the Linux kernel
6555 coding style; see the file "Documentation/CodingStyle" and the script
6556 "scripts/Lindent" in your Linux kernel source directory.
6558 Source files originating from a different project (for example the
6559 MTD subsystem) are generally exempt from these guidelines and are not
6560 reformated to ease subsequent migration to newer versions of those
6563 Please note that U-Boot is implemented in C (and to some small parts in
6564 Assembler); no C++ is used, so please do not use C++ style comments (//)
6567 Please also stick to the following formatting rules:
6568 - remove any trailing white space
6569 - use TAB characters for indentation and vertical alignment, not spaces
6570 - make sure NOT to use DOS '\r\n' line feeds
6571 - do not add more than 2 consecutive empty lines to source files
6572 - do not add trailing empty lines to source files
6574 Submissions which do not conform to the standards may be returned
6575 with a request to reformat the changes.
6581 Since the number of patches for U-Boot is growing, we need to
6582 establish some rules. Submissions which do not conform to these rules
6583 may be rejected, even when they contain important and valuable stuff.
6585 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6588 see http://lists.denx.de/mailman/listinfo/u-boot
6590 When you send a patch, please include the following information with
6593 * For bug fixes: a description of the bug and how your patch fixes
6594 this bug. Please try to include a way of demonstrating that the
6595 patch actually fixes something.
6597 * For new features: a description of the feature and your
6600 * A CHANGELOG entry as plaintext (separate from the patch)
6602 * For major contributions, your entry to the CREDITS file
6604 * When you add support for a new board, don't forget to add a
6605 maintainer e-mail address to the boards.cfg file, too.
6607 * If your patch adds new configuration options, don't forget to
6608 document these in the README file.
6610 * The patch itself. If you are using git (which is *strongly*
6611 recommended) you can easily generate the patch using the
6612 "git format-patch". If you then use "git send-email" to send it to
6613 the U-Boot mailing list, you will avoid most of the common problems
6614 with some other mail clients.
6616 If you cannot use git, use "diff -purN OLD NEW". If your version of
6617 diff does not support these options, then get the latest version of
6620 The current directory when running this command shall be the parent
6621 directory of the U-Boot source tree (i. e. please make sure that
6622 your patch includes sufficient directory information for the
6625 We prefer patches as plain text. MIME attachments are discouraged,
6626 and compressed attachments must not be used.
6628 * If one logical set of modifications affects or creates several
6629 files, all these changes shall be submitted in a SINGLE patch file.
6631 * Changesets that contain different, unrelated modifications shall be
6632 submitted as SEPARATE patches, one patch per changeset.
6637 * Before sending the patch, run the MAKEALL script on your patched
6638 source tree and make sure that no errors or warnings are reported
6639 for any of the boards.
6641 * Keep your modifications to the necessary minimum: A patch
6642 containing several unrelated changes or arbitrary reformats will be
6643 returned with a request to re-formatting / split it.
6645 * If you modify existing code, make sure that your new code does not
6646 add to the memory footprint of the code ;-) Small is beautiful!
6647 When adding new features, these should compile conditionally only
6648 (using #ifdef), and the resulting code with the new feature
6649 disabled must not need more memory than the old code without your
6652 * Remember that there is a size limit of 100 kB per message on the
6653 u-boot mailing list. Bigger patches will be moderated. If they are
6654 reasonable and not too big, they will be acknowledged. But patches
6655 bigger than the size limit should be avoided.
projects / J-u-boot.git / blob