2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_defconfig".
257 Example: For a TQM823L module type:
260 make TQM823L_defconfig
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
264 directory according to the instructions in cogent/README.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Marvell Family Member
325 CONFIG_SYS_MVFS - define it if you want to enable
326 multiple fs option at one time
327 for marvell soc family
329 - MPC824X Family Member (if CONFIG_MPC824X is defined)
330 Define exactly one of
331 CONFIG_MPC8240, CONFIG_MPC8245
333 - 8xx CPU Options: (if using an MPC8xx CPU)
334 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
335 get_gclk_freq() cannot work
336 e.g. if there is no 32KHz
337 reference PIT/RTC clock
338 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
341 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
342 CONFIG_SYS_8xx_CPUCLK_MIN
343 CONFIG_SYS_8xx_CPUCLK_MAX
344 CONFIG_8xx_CPUCLK_DEFAULT
345 See doc/README.MPC866
347 CONFIG_SYS_MEASURE_CPUCLK
349 Define this to measure the actual CPU clock instead
350 of relying on the correctness of the configured
351 values. Mostly useful for board bringup to make sure
352 the PLL is locked at the intended frequency. Note
353 that this requires a (stable) reference clock (32 kHz
354 RTC clock or CONFIG_SYS_8XX_XIN)
356 CONFIG_SYS_DELAYED_ICACHE
358 Define this option if you want to enable the
359 ICache only when Code runs from RAM.
364 Specifies that the core is a 64-bit PowerPC implementation (implements
365 the "64" category of the Power ISA). This is necessary for ePAPR
366 compliance, among other possible reasons.
368 CONFIG_SYS_FSL_TBCLK_DIV
370 Defines the core time base clock divider ratio compared to the
371 system clock. On most PQ3 devices this is 8, on newer QorIQ
372 devices it can be 16 or 32. The ratio varies from SoC to Soc.
374 CONFIG_SYS_FSL_PCIE_COMPAT
376 Defines the string to utilize when trying to match PCIe device
377 tree nodes for the given platform.
379 CONFIG_SYS_PPC_E500_DEBUG_TLB
381 Enables a temporary TLB entry to be used during boot to work
382 around limitations in e500v1 and e500v2 external debugger
383 support. This reduces the portions of the boot code where
384 breakpoints and single stepping do not work. The value of this
385 symbol should be set to the TLB1 entry to be used for this
388 CONFIG_SYS_FSL_ERRATUM_A004510
390 Enables a workaround for erratum A004510. If set,
391 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
392 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
394 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
395 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
397 Defines one or two SoC revisions (low 8 bits of SVR)
398 for which the A004510 workaround should be applied.
400 The rest of SVR is either not relevant to the decision
401 of whether the erratum is present (e.g. p2040 versus
402 p2041) or is implied by the build target, which controls
403 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
405 See Freescale App Note 4493 for more information about
408 CONFIG_A003399_NOR_WORKAROUND
409 Enables a workaround for IFC erratum A003399. It is only
410 requred during NOR boot.
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 CONFIG_SYS_FSL_DSP_DDR_ADDR
418 This value denotes start offset of DDR memory which is
419 connected exclusively to the DSP cores.
421 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
422 This value denotes start offset of M2 memory
423 which is directly connected to the DSP core.
425 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
426 This value denotes start offset of M3 memory which is directly
427 connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
433 Single Source Clock is clocking mode present in some of FSL SoC's.
434 In this mode, a single differential clock is used to supply
435 clocks to the sysclock, ddrclock and usbclock.
437 CONFIG_SYS_CPC_REINIT_F
438 This CONFIG is defined when the CPC is configured as SRAM at the
439 time of U-boot entry and is required to be re-initialized.
442 Inidcates this SoC supports deep sleep feature. If deep sleep is
443 supported, core will start to execute uboot when wakes up.
445 - Generic CPU options:
446 CONFIG_SYS_GENERIC_GLOBAL_DATA
447 Defines global data is initialized in generic board board_init_f().
448 If this macro is defined, global data is created and cleared in
449 generic board board_init_f(). Without this macro, architecture/board
450 should initialize global data before calling board_init_f().
452 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
454 Defines the endianess of the CPU. Implementation of those
455 values is arch specific.
458 Freescale DDR driver in use. This type of DDR controller is
459 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
462 CONFIG_SYS_FSL_DDR_ADDR
463 Freescale DDR memory-mapped register base.
465 CONFIG_SYS_FSL_DDR_EMU
466 Specify emulator support for DDR. Some DDR features such as
467 deskew training are not available.
469 CONFIG_SYS_FSL_DDRC_GEN1
470 Freescale DDR1 controller.
472 CONFIG_SYS_FSL_DDRC_GEN2
473 Freescale DDR2 controller.
475 CONFIG_SYS_FSL_DDRC_GEN3
476 Freescale DDR3 controller.
478 CONFIG_SYS_FSL_DDRC_GEN4
479 Freescale DDR4 controller.
481 CONFIG_SYS_FSL_DDRC_ARM_GEN3
482 Freescale DDR3 controller for ARM-based SoCs.
485 Board config to use DDR1. It can be enabled for SoCs with
486 Freescale DDR1 or DDR2 controllers, depending on the board
490 Board config to use DDR2. It can be eanbeld for SoCs with
491 Freescale DDR2 or DDR3 controllers, depending on the board
495 Board config to use DDR3. It can be enabled for SoCs with
496 Freescale DDR3 or DDR3L controllers.
499 Board config to use DDR3L. It can be enabled for SoCs with
503 Board config to use DDR4. It can be enabled for SoCs with
506 CONFIG_SYS_FSL_IFC_BE
507 Defines the IFC controller register space as Big Endian
509 CONFIG_SYS_FSL_IFC_LE
510 Defines the IFC controller register space as Little Endian
512 CONFIG_SYS_FSL_PBL_PBI
513 It enables addition of RCW (Power on reset configuration) in built image.
514 Please refer doc/README.pblimage for more details
516 CONFIG_SYS_FSL_PBL_RCW
517 It adds PBI(pre-boot instructions) commands in u-boot build image.
518 PBI commands can be used to configure SoC before it starts the execution.
519 Please refer doc/README.pblimage for more details
522 It adds a target to create boot binary having SPL binary in PBI format
523 concatenated with u-boot binary.
525 CONFIG_SYS_FSL_DDR_BE
526 Defines the DDR controller register space as Big Endian
528 CONFIG_SYS_FSL_DDR_LE
529 Defines the DDR controller register space as Little Endian
531 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
532 Physical address from the view of DDR controllers. It is the
533 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
534 it could be different for ARM SoCs.
536 CONFIG_SYS_FSL_DDR_INTLV_256B
537 DDR controller interleaving on 256-byte. This is a special
538 interleaving mode, handled by Dickens for Freescale layerscape
541 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
542 Number of controllers used as main memory.
544 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
545 Number of controllers used for other than main memory.
547 CONFIG_SYS_FSL_SEC_BE
548 Defines the SEC controller register space as Big Endian
550 CONFIG_SYS_FSL_SEC_LE
551 Defines the SEC controller register space as Little Endian
553 - Intel Monahans options:
554 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
556 Defines the Monahans run mode to oscillator
557 ratio. Valid values are 8, 16, 24, 31. The core
558 frequency is this value multiplied by 13 MHz.
560 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
562 Defines the Monahans turbo mode to oscillator
563 ratio. Valid values are 1 (default if undefined) and
564 2. The core frequency as calculated above is multiplied
568 CONFIG_SYS_INIT_SP_OFFSET
570 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
571 pointer. This is needed for the temporary stack before
574 CONFIG_SYS_MIPS_CACHE_MODE
576 Cache operation mode for the MIPS CPU.
577 See also arch/mips/include/asm/mipsregs.h.
579 CONF_CM_CACHABLE_NO_WA
582 CONF_CM_CACHABLE_NONCOHERENT
586 CONF_CM_CACHABLE_ACCELERATED
588 CONFIG_SYS_XWAY_EBU_BOOTCFG
590 Special option for Lantiq XWAY SoCs for booting from NOR flash.
591 See also arch/mips/cpu/mips32/start.S.
593 CONFIG_XWAY_SWAP_BYTES
595 Enable compilation of tools/xway-swap-bytes needed for Lantiq
596 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
597 be swapped if a flash programmer is used.
600 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
602 Select high exception vectors of the ARM core, e.g., do not
603 clear the V bit of the c1 register of CP15.
605 CONFIG_SYS_THUMB_BUILD
607 Use this flag to build U-Boot using the Thumb instruction
608 set for ARM architectures. Thumb instruction set provides
609 better code density. For ARM architectures that support
610 Thumb2 this flag will result in Thumb2 code generated by
613 CONFIG_ARM_ERRATA_716044
614 CONFIG_ARM_ERRATA_742230
615 CONFIG_ARM_ERRATA_743622
616 CONFIG_ARM_ERRATA_751472
617 CONFIG_ARM_ERRATA_794072
618 CONFIG_ARM_ERRATA_761320
620 If set, the workarounds for these ARM errata are applied early
621 during U-Boot startup. Note that these options force the
622 workarounds to be applied; no CPU-type/version detection
623 exists, unlike the similar options in the Linux kernel. Do not
624 set these options unless they apply!
626 - Linux Kernel Interface:
629 U-Boot stores all clock information in Hz
630 internally. For binary compatibility with older Linux
631 kernels (which expect the clocks passed in the
632 bd_info data to be in MHz) the environment variable
633 "clocks_in_mhz" can be defined so that U-Boot
634 converts clock data to MHZ before passing it to the
636 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
637 "clocks_in_mhz=1" is automatically included in the
640 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
642 When transferring memsize parameter to linux, some versions
643 expect it to be in bytes, others in MB.
644 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
648 New kernel versions are expecting firmware settings to be
649 passed using flattened device trees (based on open firmware
653 * New libfdt-based support
654 * Adds the "fdt" command
655 * The bootm command automatically updates the fdt
657 OF_CPU - The proper name of the cpus node (only required for
658 MPC512X and MPC5xxx based boards).
659 OF_SOC - The proper name of the soc node (only required for
660 MPC512X and MPC5xxx based boards).
661 OF_TBCLK - The timebase frequency.
662 OF_STDOUT_PATH - The path to the console device
664 boards with QUICC Engines require OF_QE to set UCC MAC
667 CONFIG_OF_BOARD_SETUP
669 Board code has addition modification that it wants to make
670 to the flat device tree before handing it off to the kernel
674 This define fills in the correct boot CPU in the boot
675 param header, the default value is zero if undefined.
679 U-Boot can detect if an IDE device is present or not.
680 If not, and this new config option is activated, U-Boot
681 removes the ATA node from the DTS before booting Linux,
682 so the Linux IDE driver does not probe the device and
683 crash. This is needed for buggy hardware (uc101) where
684 no pull down resistor is connected to the signal IDE5V_DD7.
686 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
688 This setting is mandatory for all boards that have only one
689 machine type and must be used to specify the machine type
690 number as it appears in the ARM machine registry
691 (see http://www.arm.linux.org.uk/developer/machines/).
692 Only boards that have multiple machine types supported
693 in a single configuration file and the machine type is
694 runtime discoverable, do not have to use this setting.
696 - vxWorks boot parameters:
698 bootvx constructs a valid bootline using the following
699 environments variables: bootfile, ipaddr, serverip, hostname.
700 It loads the vxWorks image pointed bootfile.
702 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
703 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
704 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
705 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
707 CONFIG_SYS_VXWORKS_ADD_PARAMS
709 Add it at the end of the bootline. E.g "u=username pw=secret"
711 Note: If a "bootargs" environment is defined, it will overwride
712 the defaults discussed just above.
714 - Cache Configuration:
715 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
716 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
717 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
719 - Cache Configuration for ARM:
720 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
722 CONFIG_SYS_PL310_BASE - Physical base address of PL310
723 controller register space
728 Define this if you want support for Amba PrimeCell PL010 UARTs.
732 Define this if you want support for Amba PrimeCell PL011 UARTs.
736 If you have Amba PrimeCell PL011 UARTs, set this variable to
737 the clock speed of the UARTs.
741 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
742 define this to a list of base addresses for each (supported)
743 port. See e.g. include/configs/versatile.h
745 CONFIG_PL011_SERIAL_RLCR
747 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
748 have separate receive and transmit line control registers. Set
749 this variable to initialize the extra register.
751 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
753 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
754 boot loader that has already initialized the UART. Define this
755 variable to flush the UART at init time.
757 CONFIG_SERIAL_HW_FLOW_CONTROL
759 Define this variable to enable hw flow control in serial driver.
760 Current user of this option is drivers/serial/nsl16550.c driver
763 Depending on board, define exactly one serial port
764 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
765 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
766 console by defining CONFIG_8xx_CONS_NONE
768 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
769 port routines must be defined elsewhere
770 (i.e. serial_init(), serial_getc(), ...)
773 Enables console device for a color framebuffer. Needs following
774 defines (cf. smiLynxEM, i8042)
775 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
777 VIDEO_HW_RECTFILL graphic chip supports
780 VIDEO_HW_BITBLT graphic chip supports
781 bit-blit (cf. smiLynxEM)
782 VIDEO_VISIBLE_COLS visible pixel columns
784 VIDEO_VISIBLE_ROWS visible pixel rows
785 VIDEO_PIXEL_SIZE bytes per pixel
786 VIDEO_DATA_FORMAT graphic data format
787 (0-5, cf. cfb_console.c)
788 VIDEO_FB_ADRS framebuffer address
789 VIDEO_KBD_INIT_FCT keyboard int fct
790 (i.e. i8042_kbd_init())
791 VIDEO_TSTC_FCT test char fct
793 VIDEO_GETC_FCT get char fct
795 CONFIG_CONSOLE_CURSOR cursor drawing on/off
796 (requires blink timer
798 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
799 CONFIG_CONSOLE_TIME display time/date info in
801 (requires CONFIG_CMD_DATE)
802 CONFIG_VIDEO_LOGO display Linux logo in
804 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
805 linux_logo.h for logo.
806 Requires CONFIG_VIDEO_LOGO
807 CONFIG_CONSOLE_EXTRA_INFO
808 additional board info beside
811 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
812 a limited number of ANSI escape sequences (cursor control,
813 erase functions and limited graphics rendition control).
815 When CONFIG_CFB_CONSOLE is defined, video console is
816 default i/o. Serial console can be forced with
817 environment 'console=serial'.
819 When CONFIG_SILENT_CONSOLE is defined, all console
820 messages (by U-Boot and Linux!) can be silenced with
821 the "silent" environment variable. See
822 doc/README.silent for more information.
824 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
826 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
830 CONFIG_BAUDRATE - in bps
831 Select one of the baudrates listed in
832 CONFIG_SYS_BAUDRATE_TABLE, see below.
833 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
835 - Console Rx buffer length
836 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
837 the maximum receive buffer length for the SMC.
838 This option is actual only for 82xx and 8xx possible.
839 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
840 must be defined, to setup the maximum idle timeout for
843 - Pre-Console Buffer:
844 Prior to the console being initialised (i.e. serial UART
845 initialised etc) all console output is silently discarded.
846 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
847 buffer any console messages prior to the console being
848 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
849 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
850 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
851 bytes are output before the console is initialised, the
852 earlier bytes are discarded.
854 'Sane' compilers will generate smaller code if
855 CONFIG_PRE_CON_BUF_SZ is a power of 2
857 - Safe printf() functions
858 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
859 the printf() functions. These are defined in
860 include/vsprintf.h and include snprintf(), vsnprintf() and
861 so on. Code size increase is approximately 300-500 bytes.
862 If this option is not given then these functions will
863 silently discard their buffer size argument - this means
864 you are not getting any overflow checking in this case.
866 - Boot Delay: CONFIG_BOOTDELAY - in seconds
867 Delay before automatically booting the default image;
868 set to -1 to disable autoboot.
869 set to -2 to autoboot with no delay and not check for abort
870 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
872 See doc/README.autoboot for these options that
873 work with CONFIG_BOOTDELAY. None are required.
874 CONFIG_BOOT_RETRY_TIME
875 CONFIG_BOOT_RETRY_MIN
876 CONFIG_AUTOBOOT_KEYED
877 CONFIG_AUTOBOOT_PROMPT
878 CONFIG_AUTOBOOT_DELAY_STR
879 CONFIG_AUTOBOOT_STOP_STR
880 CONFIG_AUTOBOOT_DELAY_STR2
881 CONFIG_AUTOBOOT_STOP_STR2
882 CONFIG_ZERO_BOOTDELAY_CHECK
883 CONFIG_RESET_TO_RETRY
887 Only needed when CONFIG_BOOTDELAY is enabled;
888 define a command string that is automatically executed
889 when no character is read on the console interface
890 within "Boot Delay" after reset.
893 This can be used to pass arguments to the bootm
894 command. The value of CONFIG_BOOTARGS goes into the
895 environment value "bootargs".
897 CONFIG_RAMBOOT and CONFIG_NFSBOOT
898 The value of these goes into the environment as
899 "ramboot" and "nfsboot" respectively, and can be used
900 as a convenience, when switching between booting from
904 CONFIG_BOOTCOUNT_LIMIT
905 Implements a mechanism for detecting a repeating reboot
907 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
910 If no softreset save registers are found on the hardware
911 "bootcount" is stored in the environment. To prevent a
912 saveenv on all reboots, the environment variable
913 "upgrade_available" is used. If "upgrade_available" is
914 0, "bootcount" is always 0, if "upgrade_available" is
915 1 "bootcount" is incremented in the environment.
916 So the Userspace Applikation must set the "upgrade_available"
917 and "bootcount" variable to 0, if a boot was successfully.
922 When this option is #defined, the existence of the
923 environment variable "preboot" will be checked
924 immediately before starting the CONFIG_BOOTDELAY
925 countdown and/or running the auto-boot command resp.
926 entering interactive mode.
928 This feature is especially useful when "preboot" is
929 automatically generated or modified. For an example
930 see the LWMON board specific code: here "preboot" is
931 modified when the user holds down a certain
932 combination of keys on the (special) keyboard when
935 - Serial Download Echo Mode:
937 If defined to 1, all characters received during a
938 serial download (using the "loads" command) are
939 echoed back. This might be needed by some terminal
940 emulations (like "cu"), but may as well just take
941 time on others. This setting #define's the initial
942 value of the "loads_echo" environment variable.
944 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
946 Select one of the baudrates listed in
947 CONFIG_SYS_BAUDRATE_TABLE, see below.
950 Monitor commands can be included or excluded
951 from the build by using the #include files
952 <config_cmd_all.h> and #undef'ing unwanted
953 commands, or using <config_cmd_default.h>
954 and augmenting with additional #define's
957 The default command configuration includes all commands
958 except those marked below with a "*".
960 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
961 CONFIG_CMD_ASKENV * ask for env variable
962 CONFIG_CMD_BDI bdinfo
963 CONFIG_CMD_BEDBUG * Include BedBug Debugger
964 CONFIG_CMD_BMP * BMP support
965 CONFIG_CMD_BSP * Board specific commands
966 CONFIG_CMD_BOOTD bootd
967 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
968 CONFIG_CMD_CACHE * icache, dcache
969 CONFIG_CMD_CLK * clock command support
970 CONFIG_CMD_CONSOLE coninfo
971 CONFIG_CMD_CRC32 * crc32
972 CONFIG_CMD_DATE * support for RTC, date/time...
973 CONFIG_CMD_DHCP * DHCP support
974 CONFIG_CMD_DIAG * Diagnostics
975 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
976 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
977 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
978 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
979 CONFIG_CMD_DTT * Digital Therm and Thermostat
980 CONFIG_CMD_ECHO echo arguments
981 CONFIG_CMD_EDITENV edit env variable
982 CONFIG_CMD_EEPROM * EEPROM read/write support
983 CONFIG_CMD_ELF * bootelf, bootvx
984 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
985 CONFIG_CMD_ENV_FLAGS * display details about env flags
986 CONFIG_CMD_ENV_EXISTS * check existence of env variable
987 CONFIG_CMD_EXPORTENV * export the environment
988 CONFIG_CMD_EXT2 * ext2 command support
989 CONFIG_CMD_EXT4 * ext4 command support
990 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
991 that work for multiple fs types
992 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
993 CONFIG_CMD_SAVEENV saveenv
994 CONFIG_CMD_FDC * Floppy Disk Support
995 CONFIG_CMD_FAT * FAT command support
996 CONFIG_CMD_FLASH flinfo, erase, protect
997 CONFIG_CMD_FPGA FPGA device initialization support
998 CONFIG_CMD_FUSE * Device fuse support
999 CONFIG_CMD_GETTIME * Get time since boot
1000 CONFIG_CMD_GO * the 'go' command (exec code)
1001 CONFIG_CMD_GREPENV * search environment
1002 CONFIG_CMD_HASH * calculate hash / digest
1003 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1004 CONFIG_CMD_I2C * I2C serial bus support
1005 CONFIG_CMD_IDE * IDE harddisk support
1006 CONFIG_CMD_IMI iminfo
1007 CONFIG_CMD_IMLS List all images found in NOR flash
1008 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1009 CONFIG_CMD_IMMAP * IMMR dump support
1010 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1011 CONFIG_CMD_IMPORTENV * import an environment
1012 CONFIG_CMD_INI * import data from an ini file into the env
1013 CONFIG_CMD_IRQ * irqinfo
1014 CONFIG_CMD_ITEST Integer/string test of 2 values
1015 CONFIG_CMD_JFFS2 * JFFS2 Support
1016 CONFIG_CMD_KGDB * kgdb
1017 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1018 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1020 CONFIG_CMD_LOADB loadb
1021 CONFIG_CMD_LOADS loads
1022 CONFIG_CMD_MD5SUM * print md5 message digest
1023 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1024 CONFIG_CMD_MEMINFO * Display detailed memory information
1025 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1027 CONFIG_CMD_MEMTEST * mtest
1028 CONFIG_CMD_MISC Misc functions like sleep etc
1029 CONFIG_CMD_MMC * MMC memory mapped support
1030 CONFIG_CMD_MII * MII utility commands
1031 CONFIG_CMD_MTDPARTS * MTD partition support
1032 CONFIG_CMD_NAND * NAND support
1033 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1034 CONFIG_CMD_NFS NFS support
1035 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1036 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1037 CONFIG_CMD_PCI * pciinfo
1038 CONFIG_CMD_PCMCIA * PCMCIA support
1039 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1041 CONFIG_CMD_PORTIO * Port I/O
1042 CONFIG_CMD_READ * Read raw data from partition
1043 CONFIG_CMD_REGINFO * Register dump
1044 CONFIG_CMD_RUN run command in env variable
1045 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1046 CONFIG_CMD_SAVES * save S record dump
1047 CONFIG_CMD_SCSI * SCSI Support
1048 CONFIG_CMD_SDRAM * print SDRAM configuration information
1049 (requires CONFIG_CMD_I2C)
1050 CONFIG_CMD_SETGETDCR Support for DCR Register access
1052 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1053 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1054 (requires CONFIG_CMD_MEMORY)
1055 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1056 CONFIG_CMD_SOURCE "source" command Support
1057 CONFIG_CMD_SPI * SPI serial bus support
1058 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1059 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1060 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1061 CONFIG_CMD_TIMER * access to the system tick timer
1062 CONFIG_CMD_USB * USB support
1063 CONFIG_CMD_CDP * Cisco Discover Protocol support
1064 CONFIG_CMD_MFSL * Microblaze FSL support
1065 CONFIG_CMD_XIMG Load part of Multi Image
1066 CONFIG_CMD_UUID * Generate random UUID or GUID string
1068 EXAMPLE: If you want all functions except of network
1069 support you can write:
1071 #include "config_cmd_all.h"
1072 #undef CONFIG_CMD_NET
1075 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1077 Note: Don't enable the "icache" and "dcache" commands
1078 (configuration option CONFIG_CMD_CACHE) unless you know
1079 what you (and your U-Boot users) are doing. Data
1080 cache cannot be enabled on systems like the 8xx or
1081 8260 (where accesses to the IMMR region must be
1082 uncached), and it cannot be disabled on all other
1083 systems where we (mis-) use the data cache to hold an
1084 initial stack and some data.
1087 XXX - this list needs to get updated!
1089 - Regular expression support:
1091 If this variable is defined, U-Boot is linked against
1092 the SLRE (Super Light Regular Expression) library,
1093 which adds regex support to some commands, as for
1094 example "env grep" and "setexpr".
1098 If this variable is defined, U-Boot will use a device tree
1099 to configure its devices, instead of relying on statically
1100 compiled #defines in the board file. This option is
1101 experimental and only available on a few boards. The device
1102 tree is available in the global data as gd->fdt_blob.
1104 U-Boot needs to get its device tree from somewhere. This can
1105 be done using one of the two options below:
1108 If this variable is defined, U-Boot will embed a device tree
1109 binary in its image. This device tree file should be in the
1110 board directory and called <soc>-<board>.dts. The binary file
1111 is then picked up in board_init_f() and made available through
1112 the global data structure as gd->blob.
1115 If this variable is defined, U-Boot will build a device tree
1116 binary. It will be called u-boot.dtb. Architecture-specific
1117 code will locate it at run-time. Generally this works by:
1119 cat u-boot.bin u-boot.dtb >image.bin
1121 and in fact, U-Boot does this for you, creating a file called
1122 u-boot-dtb.bin which is useful in the common case. You can
1123 still use the individual files if you need something more
1128 If this variable is defined, it enables watchdog
1129 support for the SoC. There must be support in the SoC
1130 specific code for a watchdog. For the 8xx and 8260
1131 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1132 register. When supported for a specific SoC is
1133 available, then no further board specific code should
1134 be needed to use it.
1137 When using a watchdog circuitry external to the used
1138 SoC, then define this variable and provide board
1139 specific code for the "hw_watchdog_reset" function.
1142 CONFIG_VERSION_VARIABLE
1143 If this variable is defined, an environment variable
1144 named "ver" is created by U-Boot showing the U-Boot
1145 version as printed by the "version" command.
1146 Any change to this variable will be reverted at the
1151 When CONFIG_CMD_DATE is selected, the type of the RTC
1152 has to be selected, too. Define exactly one of the
1155 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1156 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1157 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1158 CONFIG_RTC_MC146818 - use MC146818 RTC
1159 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1160 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1161 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1162 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1163 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1164 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1165 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1166 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1167 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1170 Note that if the RTC uses I2C, then the I2C interface
1171 must also be configured. See I2C Support, below.
1174 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1176 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1177 chip-ngpio pairs that tell the PCA953X driver the number of
1178 pins supported by a particular chip.
1180 Note that if the GPIO device uses I2C, then the I2C interface
1181 must also be configured. See I2C Support, below.
1184 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1185 accesses and can checksum them or write a list of them out
1186 to memory. See the 'iotrace' command for details. This is
1187 useful for testing device drivers since it can confirm that
1188 the driver behaves the same way before and after a code
1189 change. Currently this is supported on sandbox and arm. To
1190 add support for your architecture, add '#include <iotrace.h>'
1191 to the bottom of arch/<arch>/include/asm/io.h and test.
1193 Example output from the 'iotrace stats' command is below.
1194 Note that if the trace buffer is exhausted, the checksum will
1195 still continue to operate.
1198 Start: 10000000 (buffer start address)
1199 Size: 00010000 (buffer size)
1200 Offset: 00000120 (current buffer offset)
1201 Output: 10000120 (start + offset)
1202 Count: 00000018 (number of trace records)
1203 CRC32: 9526fb66 (CRC32 of all trace records)
1205 - Timestamp Support:
1207 When CONFIG_TIMESTAMP is selected, the timestamp
1208 (date and time) of an image is printed by image
1209 commands like bootm or iminfo. This option is
1210 automatically enabled when you select CONFIG_CMD_DATE .
1212 - Partition Labels (disklabels) Supported:
1213 Zero or more of the following:
1214 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1215 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1216 Intel architecture, USB sticks, etc.
1217 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1218 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1219 bootloader. Note 2TB partition limit; see
1221 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1223 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1224 CONFIG_CMD_SCSI) you must configure support for at
1225 least one non-MTD partition type as well.
1228 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1229 board configurations files but used nowhere!
1231 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1232 be performed by calling the function
1233 ide_set_reset(int reset)
1234 which has to be defined in a board specific file
1239 Set this to enable ATAPI support.
1244 Set this to enable support for disks larger than 137GB
1245 Also look at CONFIG_SYS_64BIT_LBA.
1246 Whithout these , LBA48 support uses 32bit variables and will 'only'
1247 support disks up to 2.1TB.
1249 CONFIG_SYS_64BIT_LBA:
1250 When enabled, makes the IDE subsystem use 64bit sector addresses.
1254 At the moment only there is only support for the
1255 SYM53C8XX SCSI controller; define
1256 CONFIG_SCSI_SYM53C8XX to enable it.
1258 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1259 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1260 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1261 maximum numbers of LUNs, SCSI ID's and target
1263 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1265 The environment variable 'scsidevs' is set to the number of
1266 SCSI devices found during the last scan.
1268 - NETWORK Support (PCI):
1270 Support for Intel 8254x/8257x gigabit chips.
1273 Utility code for direct access to the SPI bus on Intel 8257x.
1274 This does not do anything useful unless you set at least one
1275 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1277 CONFIG_E1000_SPI_GENERIC
1278 Allow generic access to the SPI bus on the Intel 8257x, for
1279 example with the "sspi" command.
1282 Management command for E1000 devices. When used on devices
1283 with SPI support you can reprogram the EEPROM from U-Boot.
1285 CONFIG_E1000_FALLBACK_MAC
1286 default MAC for empty EEPROM after production.
1289 Support for Intel 82557/82559/82559ER chips.
1290 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1291 write routine for first time initialisation.
1294 Support for Digital 2114x chips.
1295 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1296 modem chip initialisation (KS8761/QS6611).
1299 Support for National dp83815 chips.
1302 Support for National dp8382[01] gigabit chips.
1304 - NETWORK Support (other):
1306 CONFIG_DRIVER_AT91EMAC
1307 Support for AT91RM9200 EMAC.
1310 Define this to use reduced MII inteface
1312 CONFIG_DRIVER_AT91EMAC_QUIET
1313 If this defined, the driver is quiet.
1314 The driver doen't show link status messages.
1316 CONFIG_CALXEDA_XGMAC
1317 Support for the Calxeda XGMAC device
1320 Support for SMSC's LAN91C96 chips.
1322 CONFIG_LAN91C96_BASE
1323 Define this to hold the physical address
1324 of the LAN91C96's I/O space
1326 CONFIG_LAN91C96_USE_32_BIT
1327 Define this to enable 32 bit addressing
1330 Support for SMSC's LAN91C111 chip
1332 CONFIG_SMC91111_BASE
1333 Define this to hold the physical address
1334 of the device (I/O space)
1336 CONFIG_SMC_USE_32_BIT
1337 Define this if data bus is 32 bits
1339 CONFIG_SMC_USE_IOFUNCS
1340 Define this to use i/o functions instead of macros
1341 (some hardware wont work with macros)
1343 CONFIG_DRIVER_TI_EMAC
1344 Support for davinci emac
1346 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1347 Define this if you have more then 3 PHYs.
1350 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1352 CONFIG_FTGMAC100_EGIGA
1353 Define this to use GE link update with gigabit PHY.
1354 Define this if FTGMAC100 is connected to gigabit PHY.
1355 If your system has 10/100 PHY only, it might not occur
1356 wrong behavior. Because PHY usually return timeout or
1357 useless data when polling gigabit status and gigabit
1358 control registers. This behavior won't affect the
1359 correctnessof 10/100 link speed update.
1362 Support for SMSC's LAN911x and LAN921x chips
1365 Define this to hold the physical address
1366 of the device (I/O space)
1368 CONFIG_SMC911X_32_BIT
1369 Define this if data bus is 32 bits
1371 CONFIG_SMC911X_16_BIT
1372 Define this if data bus is 16 bits. If your processor
1373 automatically converts one 32 bit word to two 16 bit
1374 words you may also try CONFIG_SMC911X_32_BIT.
1377 Support for Renesas on-chip Ethernet controller
1379 CONFIG_SH_ETHER_USE_PORT
1380 Define the number of ports to be used
1382 CONFIG_SH_ETHER_PHY_ADDR
1383 Define the ETH PHY's address
1385 CONFIG_SH_ETHER_CACHE_WRITEBACK
1386 If this option is set, the driver enables cache flush.
1390 Support for PWM modul on the imx6.
1394 Support TPM devices.
1397 Support for i2c bus TPM devices. Only one device
1398 per system is supported at this time.
1400 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1401 Define the the i2c bus number for the TPM device
1403 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1404 Define the TPM's address on the i2c bus
1406 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1407 Define the burst count bytes upper limit
1409 CONFIG_TPM_ATMEL_TWI
1410 Support for Atmel TWI TPM device. Requires I2C support.
1413 Support for generic parallel port TPM devices. Only one device
1414 per system is supported at this time.
1416 CONFIG_TPM_TIS_BASE_ADDRESS
1417 Base address where the generic TPM device is mapped
1418 to. Contemporary x86 systems usually map it at
1422 Add tpm monitor functions.
1423 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1424 provides monitor access to authorized functions.
1427 Define this to enable the TPM support library which provides
1428 functional interfaces to some TPM commands.
1429 Requires support for a TPM device.
1431 CONFIG_TPM_AUTH_SESSIONS
1432 Define this to enable authorized functions in the TPM library.
1433 Requires CONFIG_TPM and CONFIG_SHA1.
1436 At the moment only the UHCI host controller is
1437 supported (PIP405, MIP405, MPC5200); define
1438 CONFIG_USB_UHCI to enable it.
1439 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1440 and define CONFIG_USB_STORAGE to enable the USB
1443 Supported are USB Keyboards and USB Floppy drives
1445 MPC5200 USB requires additional defines:
1447 for 528 MHz Clock: 0x0001bbbb
1451 for differential drivers: 0x00001000
1452 for single ended drivers: 0x00005000
1453 for differential drivers on PSC3: 0x00000100
1454 for single ended drivers on PSC3: 0x00004100
1455 CONFIG_SYS_USB_EVENT_POLL
1456 May be defined to allow interrupt polling
1457 instead of using asynchronous interrupts
1459 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1460 txfilltuning field in the EHCI controller on reset.
1462 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1463 HW module registers.
1466 Define the below if you wish to use the USB console.
1467 Once firmware is rebuilt from a serial console issue the
1468 command "setenv stdin usbtty; setenv stdout usbtty" and
1469 attach your USB cable. The Unix command "dmesg" should print
1470 it has found a new device. The environment variable usbtty
1471 can be set to gserial or cdc_acm to enable your device to
1472 appear to a USB host as a Linux gserial device or a
1473 Common Device Class Abstract Control Model serial device.
1474 If you select usbtty = gserial you should be able to enumerate
1476 # modprobe usbserial vendor=0xVendorID product=0xProductID
1477 else if using cdc_acm, simply setting the environment
1478 variable usbtty to be cdc_acm should suffice. The following
1479 might be defined in YourBoardName.h
1482 Define this to build a UDC device
1485 Define this to have a tty type of device available to
1486 talk to the UDC device
1489 Define this to enable the high speed support for usb
1490 device and usbtty. If this feature is enabled, a routine
1491 int is_usbd_high_speed(void)
1492 also needs to be defined by the driver to dynamically poll
1493 whether the enumeration has succeded at high speed or full
1496 CONFIG_SYS_CONSOLE_IS_IN_ENV
1497 Define this if you want stdin, stdout &/or stderr to
1501 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1502 Derive USB clock from external clock "blah"
1503 - CONFIG_SYS_USB_EXTC_CLK 0x02
1505 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1506 Derive USB clock from brgclk
1507 - CONFIG_SYS_USB_BRG_CLK 0x04
1509 If you have a USB-IF assigned VendorID then you may wish to
1510 define your own vendor specific values either in BoardName.h
1511 or directly in usbd_vendor_info.h. If you don't define
1512 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1513 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1514 should pretend to be a Linux device to it's target host.
1516 CONFIG_USBD_MANUFACTURER
1517 Define this string as the name of your company for
1518 - CONFIG_USBD_MANUFACTURER "my company"
1520 CONFIG_USBD_PRODUCT_NAME
1521 Define this string as the name of your product
1522 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1524 CONFIG_USBD_VENDORID
1525 Define this as your assigned Vendor ID from the USB
1526 Implementors Forum. This *must* be a genuine Vendor ID
1527 to avoid polluting the USB namespace.
1528 - CONFIG_USBD_VENDORID 0xFFFF
1530 CONFIG_USBD_PRODUCTID
1531 Define this as the unique Product ID
1533 - CONFIG_USBD_PRODUCTID 0xFFFF
1535 - ULPI Layer Support:
1536 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1537 the generic ULPI layer. The generic layer accesses the ULPI PHY
1538 via the platform viewport, so you need both the genric layer and
1539 the viewport enabled. Currently only Chipidea/ARC based
1540 viewport is supported.
1541 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1542 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1543 If your ULPI phy needs a different reference clock than the
1544 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1545 the appropriate value in Hz.
1548 The MMC controller on the Intel PXA is supported. To
1549 enable this define CONFIG_MMC. The MMC can be
1550 accessed from the boot prompt by mapping the device
1551 to physical memory similar to flash. Command line is
1552 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1553 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1556 Support for Renesas on-chip MMCIF controller
1558 CONFIG_SH_MMCIF_ADDR
1559 Define the base address of MMCIF registers
1562 Define the clock frequency for MMCIF
1565 Enable the generic MMC driver
1567 CONFIG_SUPPORT_EMMC_BOOT
1568 Enable some additional features of the eMMC boot partitions.
1570 CONFIG_SUPPORT_EMMC_RPMB
1571 Enable the commands for reading, writing and programming the
1572 key for the Replay Protection Memory Block partition in eMMC.
1574 - USB Device Firmware Update (DFU) class support:
1576 This enables the USB portion of the DFU USB class
1579 This enables the command "dfu" which is used to have
1580 U-Boot create a DFU class device via USB. This command
1581 requires that the "dfu_alt_info" environment variable be
1582 set and define the alt settings to expose to the host.
1585 This enables support for exposing (e)MMC devices via DFU.
1588 This enables support for exposing NAND devices via DFU.
1591 This enables support for exposing RAM via DFU.
1592 Note: DFU spec refer to non-volatile memory usage, but
1593 allow usages beyond the scope of spec - here RAM usage,
1594 one that would help mostly the developer.
1596 CONFIG_SYS_DFU_DATA_BUF_SIZE
1597 Dfu transfer uses a buffer before writing data to the
1598 raw storage device. Make the size (in bytes) of this buffer
1599 configurable. The size of this buffer is also configurable
1600 through the "dfu_bufsiz" environment variable.
1602 CONFIG_SYS_DFU_MAX_FILE_SIZE
1603 When updating files rather than the raw storage device,
1604 we use a static buffer to copy the file into and then write
1605 the buffer once we've been given the whole file. Define
1606 this to the maximum filesize (in bytes) for the buffer.
1607 Default is 4 MiB if undefined.
1609 DFU_DEFAULT_POLL_TIMEOUT
1610 Poll timeout [ms], is the timeout a device can send to the
1611 host. The host must wait for this timeout before sending
1612 a subsequent DFU_GET_STATUS request to the device.
1614 DFU_MANIFEST_POLL_TIMEOUT
1615 Poll timeout [ms], which the device sends to the host when
1616 entering dfuMANIFEST state. Host waits this timeout, before
1617 sending again an USB request to the device.
1619 - USB Device Android Fastboot support:
1621 This enables the command "fastboot" which enables the Android
1622 fastboot mode for the platform's USB device. Fastboot is a USB
1623 protocol for downloading images, flashing and device control
1624 used on Android devices.
1625 See doc/README.android-fastboot for more information.
1627 CONFIG_ANDROID_BOOT_IMAGE
1628 This enables support for booting images which use the Android
1629 image format header.
1631 CONFIG_USB_FASTBOOT_BUF_ADDR
1632 The fastboot protocol requires a large memory buffer for
1633 downloads. Define this to the starting RAM address to use for
1636 CONFIG_USB_FASTBOOT_BUF_SIZE
1637 The fastboot protocol requires a large memory buffer for
1638 downloads. This buffer should be as large as possible for a
1639 platform. Define this to the size available RAM for fastboot.
1641 CONFIG_FASTBOOT_FLASH
1642 The fastboot protocol includes a "flash" command for writing
1643 the downloaded image to a non-volatile storage device. Define
1644 this to enable the "fastboot flash" command.
1646 CONFIG_FASTBOOT_FLASH_MMC_DEV
1647 The fastboot "flash" command requires additional information
1648 regarding the non-volatile storage device. Define this to
1649 the eMMC device that fastboot should use to store the image.
1651 - Journaling Flash filesystem support:
1652 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1653 CONFIG_JFFS2_NAND_DEV
1654 Define these for a default partition on a NAND device
1656 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1657 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1658 Define these for a default partition on a NOR device
1660 CONFIG_SYS_JFFS_CUSTOM_PART
1661 Define this to create an own partition. You have to provide a
1662 function struct part_info* jffs2_part_info(int part_num)
1664 If you define only one JFFS2 partition you may also want to
1665 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1666 to disable the command chpart. This is the default when you
1667 have not defined a custom partition
1669 - FAT(File Allocation Table) filesystem write function support:
1672 Define this to enable support for saving memory data as a
1673 file in FAT formatted partition.
1675 This will also enable the command "fatwrite" enabling the
1676 user to write files to FAT.
1678 CBFS (Coreboot Filesystem) support
1681 Define this to enable support for reading from a Coreboot
1682 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1685 - FAT(File Allocation Table) filesystem cluster size:
1686 CONFIG_FS_FAT_MAX_CLUSTSIZE
1688 Define the max cluster size for fat operations else
1689 a default value of 65536 will be defined.
1694 Define this to enable standard (PC-Style) keyboard
1698 Standard PC keyboard driver with US (is default) and
1699 GERMAN key layout (switch via environment 'keymap=de') support.
1700 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1701 for cfb_console. Supports cursor blinking.
1704 Enables a Chrome OS keyboard using the CROS_EC interface.
1705 This uses CROS_EC to communicate with a second microcontroller
1706 which provides key scans on request.
1711 Define this to enable video support (for output to
1714 CONFIG_VIDEO_CT69000
1716 Enable Chips & Technologies 69000 Video chip
1718 CONFIG_VIDEO_SMI_LYNXEM
1719 Enable Silicon Motion SMI 712/710/810 Video chip. The
1720 video output is selected via environment 'videoout'
1721 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1724 For the CT69000 and SMI_LYNXEM drivers, videomode is
1725 selected via environment 'videomode'. Two different ways
1727 - "videomode=num" 'num' is a standard LiLo mode numbers.
1728 Following standard modes are supported (* is default):
1730 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1731 -------------+---------------------------------------------
1732 8 bits | 0x301* 0x303 0x305 0x161 0x307
1733 15 bits | 0x310 0x313 0x316 0x162 0x319
1734 16 bits | 0x311 0x314 0x317 0x163 0x31A
1735 24 bits | 0x312 0x315 0x318 ? 0x31B
1736 -------------+---------------------------------------------
1737 (i.e. setenv videomode 317; saveenv; reset;)
1739 - "videomode=bootargs" all the video parameters are parsed
1740 from the bootargs. (See drivers/video/videomodes.c)
1743 CONFIG_VIDEO_SED13806
1744 Enable Epson SED13806 driver. This driver supports 8bpp
1745 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1746 or CONFIG_VIDEO_SED13806_16BPP
1749 Enable the Freescale DIU video driver. Reference boards for
1750 SOCs that have a DIU should define this macro to enable DIU
1751 support, and should also define these other macros:
1757 CONFIG_VIDEO_SW_CURSOR
1758 CONFIG_VGA_AS_SINGLE_DEVICE
1760 CONFIG_VIDEO_BMP_LOGO
1762 The DIU driver will look for the 'video-mode' environment
1763 variable, and if defined, enable the DIU as a console during
1764 boot. See the documentation file README.video for a
1765 description of this variable.
1769 Enable the VGA video / BIOS for x86. The alternative if you
1770 are using coreboot is to use the coreboot frame buffer
1777 Define this to enable a custom keyboard support.
1778 This simply calls drv_keyboard_init() which must be
1779 defined in your board-specific files.
1780 The only board using this so far is RBC823.
1782 - LCD Support: CONFIG_LCD
1784 Define this to enable LCD support (for output to LCD
1785 display); also select one of the supported displays
1786 by defining one of these:
1790 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1792 CONFIG_NEC_NL6448AC33:
1794 NEC NL6448AC33-18. Active, color, single scan.
1796 CONFIG_NEC_NL6448BC20
1798 NEC NL6448BC20-08. 6.5", 640x480.
1799 Active, color, single scan.
1801 CONFIG_NEC_NL6448BC33_54
1803 NEC NL6448BC33-54. 10.4", 640x480.
1804 Active, color, single scan.
1808 Sharp 320x240. Active, color, single scan.
1809 It isn't 16x9, and I am not sure what it is.
1811 CONFIG_SHARP_LQ64D341
1813 Sharp LQ64D341 display, 640x480.
1814 Active, color, single scan.
1818 HLD1045 display, 640x480.
1819 Active, color, single scan.
1823 Optrex CBL50840-2 NF-FW 99 22 M5
1825 Hitachi LMG6912RPFC-00T
1829 320x240. Black & white.
1831 Normally display is black on white background; define
1832 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1834 CONFIG_LCD_ALIGNMENT
1836 Normally the LCD is page-aligned (tyically 4KB). If this is
1837 defined then the LCD will be aligned to this value instead.
1838 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1839 here, since it is cheaper to change data cache settings on
1840 a per-section basis.
1842 CONFIG_CONSOLE_SCROLL_LINES
1844 When the console need to be scrolled, this is the number of
1845 lines to scroll by. It defaults to 1. Increasing this makes
1846 the console jump but can help speed up operation when scrolling
1851 Support drawing of RLE8-compressed bitmaps on the LCD.
1855 Enables an 'i2c edid' command which can read EDID
1856 information over I2C from an attached LCD display.
1858 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1860 If this option is set, the environment is checked for
1861 a variable "splashimage". If found, the usual display
1862 of logo, copyright and system information on the LCD
1863 is suppressed and the BMP image at the address
1864 specified in "splashimage" is loaded instead. The
1865 console is redirected to the "nulldev", too. This
1866 allows for a "silent" boot where a splash screen is
1867 loaded very quickly after power-on.
1869 CONFIG_SPLASHIMAGE_GUARD
1871 If this option is set, then U-Boot will prevent the environment
1872 variable "splashimage" from being set to a problematic address
1873 (see README.displaying-bmps).
1874 This option is useful for targets where, due to alignment
1875 restrictions, an improperly aligned BMP image will cause a data
1876 abort. If you think you will not have problems with unaligned
1877 accesses (for example because your toolchain prevents them)
1878 there is no need to set this option.
1880 CONFIG_SPLASH_SCREEN_ALIGN
1882 If this option is set the splash image can be freely positioned
1883 on the screen. Environment variable "splashpos" specifies the
1884 position as "x,y". If a positive number is given it is used as
1885 number of pixel from left/top. If a negative number is given it
1886 is used as number of pixel from right/bottom. You can also
1887 specify 'm' for centering the image.
1890 setenv splashpos m,m
1891 => image at center of screen
1893 setenv splashpos 30,20
1894 => image at x = 30 and y = 20
1896 setenv splashpos -10,m
1897 => vertically centered image
1898 at x = dspWidth - bmpWidth - 9
1900 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1902 If this option is set, additionally to standard BMP
1903 images, gzipped BMP images can be displayed via the
1904 splashscreen support or the bmp command.
1906 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1908 If this option is set, 8-bit RLE compressed BMP images
1909 can be displayed via the splashscreen support or the
1912 - Do compresssing for memory range:
1915 If this option is set, it would use zlib deflate method
1916 to compress the specified memory at its best effort.
1918 - Compression support:
1921 Enabled by default to support gzip compressed images.
1925 If this option is set, support for bzip2 compressed
1926 images is included. If not, only uncompressed and gzip
1927 compressed images are supported.
1929 NOTE: the bzip2 algorithm requires a lot of RAM, so
1930 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1935 If this option is set, support for lzma compressed
1938 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1939 requires an amount of dynamic memory that is given by the
1942 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1944 Where lc and lp stand for, respectively, Literal context bits
1945 and Literal pos bits.
1947 This value is upper-bounded by 14MB in the worst case. Anyway,
1948 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1949 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1950 a very small buffer.
1952 Use the lzmainfo tool to determinate the lc and lp values and
1953 then calculate the amount of needed dynamic memory (ensuring
1954 the appropriate CONFIG_SYS_MALLOC_LEN value).
1958 If this option is set, support for LZO compressed images
1964 The address of PHY on MII bus.
1966 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1968 The clock frequency of the MII bus
1972 If this option is set, support for speed/duplex
1973 detection of gigabit PHY is included.
1975 CONFIG_PHY_RESET_DELAY
1977 Some PHY like Intel LXT971A need extra delay after
1978 reset before any MII register access is possible.
1979 For such PHY, set this option to the usec delay
1980 required. (minimum 300usec for LXT971A)
1982 CONFIG_PHY_CMD_DELAY (ppc4xx)
1984 Some PHY like Intel LXT971A need extra delay after
1985 command issued before MII status register can be read
1995 Define a default value for Ethernet address to use
1996 for the respective Ethernet interface, in case this
1997 is not determined automatically.
2002 Define a default value for the IP address to use for
2003 the default Ethernet interface, in case this is not
2004 determined through e.g. bootp.
2005 (Environment variable "ipaddr")
2007 - Server IP address:
2010 Defines a default value for the IP address of a TFTP
2011 server to contact when using the "tftboot" command.
2012 (Environment variable "serverip")
2014 CONFIG_KEEP_SERVERADDR
2016 Keeps the server's MAC address, in the env 'serveraddr'
2017 for passing to bootargs (like Linux's netconsole option)
2019 - Gateway IP address:
2022 Defines a default value for the IP address of the
2023 default router where packets to other networks are
2025 (Environment variable "gatewayip")
2030 Defines a default value for the subnet mask (or
2031 routing prefix) which is used to determine if an IP
2032 address belongs to the local subnet or needs to be
2033 forwarded through a router.
2034 (Environment variable "netmask")
2036 - Multicast TFTP Mode:
2039 Defines whether you want to support multicast TFTP as per
2040 rfc-2090; for example to work with atftp. Lets lots of targets
2041 tftp down the same boot image concurrently. Note: the Ethernet
2042 driver in use must provide a function: mcast() to join/leave a
2045 - BOOTP Recovery Mode:
2046 CONFIG_BOOTP_RANDOM_DELAY
2048 If you have many targets in a network that try to
2049 boot using BOOTP, you may want to avoid that all
2050 systems send out BOOTP requests at precisely the same
2051 moment (which would happen for instance at recovery
2052 from a power failure, when all systems will try to
2053 boot, thus flooding the BOOTP server. Defining
2054 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2055 inserted before sending out BOOTP requests. The
2056 following delays are inserted then:
2058 1st BOOTP request: delay 0 ... 1 sec
2059 2nd BOOTP request: delay 0 ... 2 sec
2060 3rd BOOTP request: delay 0 ... 4 sec
2062 BOOTP requests: delay 0 ... 8 sec
2064 CONFIG_BOOTP_ID_CACHE_SIZE
2066 BOOTP packets are uniquely identified using a 32-bit ID. The
2067 server will copy the ID from client requests to responses and
2068 U-Boot will use this to determine if it is the destination of
2069 an incoming response. Some servers will check that addresses
2070 aren't in use before handing them out (usually using an ARP
2071 ping) and therefore take up to a few hundred milliseconds to
2072 respond. Network congestion may also influence the time it
2073 takes for a response to make it back to the client. If that
2074 time is too long, U-Boot will retransmit requests. In order
2075 to allow earlier responses to still be accepted after these
2076 retransmissions, U-Boot's BOOTP client keeps a small cache of
2077 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2078 cache. The default is to keep IDs for up to four outstanding
2079 requests. Increasing this will allow U-Boot to accept offers
2080 from a BOOTP client in networks with unusually high latency.
2082 - DHCP Advanced Options:
2083 You can fine tune the DHCP functionality by defining
2084 CONFIG_BOOTP_* symbols:
2086 CONFIG_BOOTP_SUBNETMASK
2087 CONFIG_BOOTP_GATEWAY
2088 CONFIG_BOOTP_HOSTNAME
2089 CONFIG_BOOTP_NISDOMAIN
2090 CONFIG_BOOTP_BOOTPATH
2091 CONFIG_BOOTP_BOOTFILESIZE
2094 CONFIG_BOOTP_SEND_HOSTNAME
2095 CONFIG_BOOTP_NTPSERVER
2096 CONFIG_BOOTP_TIMEOFFSET
2097 CONFIG_BOOTP_VENDOREX
2098 CONFIG_BOOTP_MAY_FAIL
2100 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2101 environment variable, not the BOOTP server.
2103 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2104 after the configured retry count, the call will fail
2105 instead of starting over. This can be used to fail over
2106 to Link-local IP address configuration if the DHCP server
2109 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2110 serverip from a DHCP server, it is possible that more
2111 than one DNS serverip is offered to the client.
2112 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2113 serverip will be stored in the additional environment
2114 variable "dnsip2". The first DNS serverip is always
2115 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2118 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2119 to do a dynamic update of a DNS server. To do this, they
2120 need the hostname of the DHCP requester.
2121 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2122 of the "hostname" environment variable is passed as
2123 option 12 to the DHCP server.
2125 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2127 A 32bit value in microseconds for a delay between
2128 receiving a "DHCP Offer" and sending the "DHCP Request".
2129 This fixes a problem with certain DHCP servers that don't
2130 respond 100% of the time to a "DHCP request". E.g. On an
2131 AT91RM9200 processor running at 180MHz, this delay needed
2132 to be *at least* 15,000 usec before a Windows Server 2003
2133 DHCP server would reply 100% of the time. I recommend at
2134 least 50,000 usec to be safe. The alternative is to hope
2135 that one of the retries will be successful but note that
2136 the DHCP timeout and retry process takes a longer than
2139 - Link-local IP address negotiation:
2140 Negotiate with other link-local clients on the local network
2141 for an address that doesn't require explicit configuration.
2142 This is especially useful if a DHCP server cannot be guaranteed
2143 to exist in all environments that the device must operate.
2145 See doc/README.link-local for more information.
2148 CONFIG_CDP_DEVICE_ID
2150 The device id used in CDP trigger frames.
2152 CONFIG_CDP_DEVICE_ID_PREFIX
2154 A two character string which is prefixed to the MAC address
2159 A printf format string which contains the ascii name of
2160 the port. Normally is set to "eth%d" which sets
2161 eth0 for the first Ethernet, eth1 for the second etc.
2163 CONFIG_CDP_CAPABILITIES
2165 A 32bit integer which indicates the device capabilities;
2166 0x00000010 for a normal host which does not forwards.
2170 An ascii string containing the version of the software.
2174 An ascii string containing the name of the platform.
2178 A 32bit integer sent on the trigger.
2180 CONFIG_CDP_POWER_CONSUMPTION
2182 A 16bit integer containing the power consumption of the
2183 device in .1 of milliwatts.
2185 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2187 A byte containing the id of the VLAN.
2189 - Status LED: CONFIG_STATUS_LED
2191 Several configurations allow to display the current
2192 status using a LED. For instance, the LED will blink
2193 fast while running U-Boot code, stop blinking as
2194 soon as a reply to a BOOTP request was received, and
2195 start blinking slow once the Linux kernel is running
2196 (supported by a status LED driver in the Linux
2197 kernel). Defining CONFIG_STATUS_LED enables this
2203 The status LED can be connected to a GPIO pin.
2204 In such cases, the gpio_led driver can be used as a
2205 status LED backend implementation. Define CONFIG_GPIO_LED
2206 to include the gpio_led driver in the U-Boot binary.
2208 CONFIG_GPIO_LED_INVERTED_TABLE
2209 Some GPIO connected LEDs may have inverted polarity in which
2210 case the GPIO high value corresponds to LED off state and
2211 GPIO low value corresponds to LED on state.
2212 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2213 with a list of GPIO LEDs that have inverted polarity.
2215 - CAN Support: CONFIG_CAN_DRIVER
2217 Defining CONFIG_CAN_DRIVER enables CAN driver support
2218 on those systems that support this (optional)
2219 feature, like the TQM8xxL modules.
2221 - I2C Support: CONFIG_SYS_I2C
2223 This enable the NEW i2c subsystem, and will allow you to use
2224 i2c commands at the u-boot command line (as long as you set
2225 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2226 based realtime clock chips or other i2c devices. See
2227 common/cmd_i2c.c for a description of the command line
2230 ported i2c driver to the new framework:
2231 - drivers/i2c/soft_i2c.c:
2232 - activate first bus with CONFIG_SYS_I2C_SOFT define
2233 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2234 for defining speed and slave address
2235 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2236 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2237 for defining speed and slave address
2238 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2239 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2240 for defining speed and slave address
2241 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2242 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2243 for defining speed and slave address
2245 - drivers/i2c/fsl_i2c.c:
2246 - activate i2c driver with CONFIG_SYS_I2C_FSL
2247 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2248 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2249 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2251 - If your board supports a second fsl i2c bus, define
2252 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2253 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2254 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2257 - drivers/i2c/tegra_i2c.c:
2258 - activate this driver with CONFIG_SYS_I2C_TEGRA
2259 - This driver adds 4 i2c buses with a fix speed from
2260 100000 and the slave addr 0!
2262 - drivers/i2c/ppc4xx_i2c.c
2263 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2264 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2265 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2267 - drivers/i2c/i2c_mxc.c
2268 - activate this driver with CONFIG_SYS_I2C_MXC
2269 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2270 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2271 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2272 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2273 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2274 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2275 If thoses defines are not set, default value is 100000
2276 for speed, and 0 for slave.
2278 - drivers/i2c/rcar_i2c.c:
2279 - activate this driver with CONFIG_SYS_I2C_RCAR
2280 - This driver adds 4 i2c buses
2282 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2283 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2284 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2285 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2286 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2287 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2288 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2289 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2290 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2292 - drivers/i2c/sh_i2c.c:
2293 - activate this driver with CONFIG_SYS_I2C_SH
2294 - This driver adds from 2 to 5 i2c buses
2296 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2297 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2298 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2299 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2300 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2301 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2302 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2303 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2304 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2305 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2306 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2307 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2308 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2310 - drivers/i2c/omap24xx_i2c.c
2311 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2312 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2313 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2314 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2315 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2316 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2317 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2318 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2319 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2320 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2321 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2323 - drivers/i2c/zynq_i2c.c
2324 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2325 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2326 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2328 - drivers/i2c/s3c24x0_i2c.c:
2329 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2330 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2331 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2332 with a fix speed from 100000 and the slave addr 0!
2334 - drivers/i2c/ihs_i2c.c
2335 - activate this driver with CONFIG_SYS_I2C_IHS
2336 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2337 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2338 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2339 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2340 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2341 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2342 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2343 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2344 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2345 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2346 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2347 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2351 CONFIG_SYS_NUM_I2C_BUSES
2352 Hold the number of i2c busses you want to use. If you
2353 don't use/have i2c muxes on your i2c bus, this
2354 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2357 CONFIG_SYS_I2C_DIRECT_BUS
2358 define this, if you don't use i2c muxes on your hardware.
2359 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2362 CONFIG_SYS_I2C_MAX_HOPS
2363 define how many muxes are maximal consecutively connected
2364 on one i2c bus. If you not use i2c muxes, omit this
2367 CONFIG_SYS_I2C_BUSES
2368 hold a list of busses you want to use, only used if
2369 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2370 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2371 CONFIG_SYS_NUM_I2C_BUSES = 9:
2373 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2374 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2375 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2376 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2377 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2378 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2379 {1, {I2C_NULL_HOP}}, \
2380 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2381 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2385 bus 0 on adapter 0 without a mux
2386 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2387 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2388 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2389 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2390 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2391 bus 6 on adapter 1 without a mux
2392 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2393 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2395 If you do not have i2c muxes on your board, omit this define.
2397 - Legacy I2C Support: CONFIG_HARD_I2C
2399 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2400 provides the following compelling advantages:
2402 - more than one i2c adapter is usable
2403 - approved multibus support
2404 - better i2c mux support
2406 ** Please consider updating your I2C driver now. **
2408 These enable legacy I2C serial bus commands. Defining
2409 CONFIG_HARD_I2C will include the appropriate I2C driver
2410 for the selected CPU.
2412 This will allow you to use i2c commands at the u-boot
2413 command line (as long as you set CONFIG_CMD_I2C in
2414 CONFIG_COMMANDS) and communicate with i2c based realtime
2415 clock chips. See common/cmd_i2c.c for a description of the
2416 command line interface.
2418 CONFIG_HARD_I2C selects a hardware I2C controller.
2420 There are several other quantities that must also be
2421 defined when you define CONFIG_HARD_I2C.
2423 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2424 to be the frequency (in Hz) at which you wish your i2c bus
2425 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2426 the CPU's i2c node address).
2428 Now, the u-boot i2c code for the mpc8xx
2429 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2430 and so its address should therefore be cleared to 0 (See,
2431 eg, MPC823e User's Manual p.16-473). So, set
2432 CONFIG_SYS_I2C_SLAVE to 0.
2434 CONFIG_SYS_I2C_INIT_MPC5XXX
2436 When a board is reset during an i2c bus transfer
2437 chips might think that the current transfer is still
2438 in progress. Reset the slave devices by sending start
2439 commands until the slave device responds.
2441 That's all that's required for CONFIG_HARD_I2C.
2443 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2444 then the following macros need to be defined (examples are
2445 from include/configs/lwmon.h):
2449 (Optional). Any commands necessary to enable the I2C
2450 controller or configure ports.
2452 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2456 (Only for MPC8260 CPU). The I/O port to use (the code
2457 assumes both bits are on the same port). Valid values
2458 are 0..3 for ports A..D.
2462 The code necessary to make the I2C data line active
2463 (driven). If the data line is open collector, this
2466 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2470 The code necessary to make the I2C data line tri-stated
2471 (inactive). If the data line is open collector, this
2474 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2478 Code that returns true if the I2C data line is high,
2481 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2485 If <bit> is true, sets the I2C data line high. If it
2486 is false, it clears it (low).
2488 eg: #define I2C_SDA(bit) \
2489 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2490 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2494 If <bit> is true, sets the I2C clock line high. If it
2495 is false, it clears it (low).
2497 eg: #define I2C_SCL(bit) \
2498 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2499 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2503 This delay is invoked four times per clock cycle so this
2504 controls the rate of data transfer. The data rate thus
2505 is 1 / (I2C_DELAY * 4). Often defined to be something
2508 #define I2C_DELAY udelay(2)
2510 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2512 If your arch supports the generic GPIO framework (asm/gpio.h),
2513 then you may alternatively define the two GPIOs that are to be
2514 used as SCL / SDA. Any of the previous I2C_xxx macros will
2515 have GPIO-based defaults assigned to them as appropriate.
2517 You should define these to the GPIO value as given directly to
2518 the generic GPIO functions.
2520 CONFIG_SYS_I2C_INIT_BOARD
2522 When a board is reset during an i2c bus transfer
2523 chips might think that the current transfer is still
2524 in progress. On some boards it is possible to access
2525 the i2c SCLK line directly, either by using the
2526 processor pin as a GPIO or by having a second pin
2527 connected to the bus. If this option is defined a
2528 custom i2c_init_board() routine in boards/xxx/board.c
2529 is run early in the boot sequence.
2531 CONFIG_SYS_I2C_BOARD_LATE_INIT
2533 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2534 defined a custom i2c_board_late_init() routine in
2535 boards/xxx/board.c is run AFTER the operations in i2c_init()
2536 is completed. This callpoint can be used to unreset i2c bus
2537 using CPU i2c controller register accesses for CPUs whose i2c
2538 controller provide such a method. It is called at the end of
2539 i2c_init() to allow i2c_init operations to setup the i2c bus
2540 controller on the CPU (e.g. setting bus speed & slave address).
2542 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2544 This option enables configuration of bi_iic_fast[] flags
2545 in u-boot bd_info structure based on u-boot environment
2546 variable "i2cfast". (see also i2cfast)
2548 CONFIG_I2C_MULTI_BUS
2550 This option allows the use of multiple I2C buses, each of which
2551 must have a controller. At any point in time, only one bus is
2552 active. To switch to a different bus, use the 'i2c dev' command.
2553 Note that bus numbering is zero-based.
2555 CONFIG_SYS_I2C_NOPROBES
2557 This option specifies a list of I2C devices that will be skipped
2558 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2559 is set, specify a list of bus-device pairs. Otherwise, specify
2560 a 1D array of device addresses
2563 #undef CONFIG_I2C_MULTI_BUS
2564 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2566 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2568 #define CONFIG_I2C_MULTI_BUS
2569 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2571 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2573 CONFIG_SYS_SPD_BUS_NUM
2575 If defined, then this indicates the I2C bus number for DDR SPD.
2576 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2578 CONFIG_SYS_RTC_BUS_NUM
2580 If defined, then this indicates the I2C bus number for the RTC.
2581 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2583 CONFIG_SYS_DTT_BUS_NUM
2585 If defined, then this indicates the I2C bus number for the DTT.
2586 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2588 CONFIG_SYS_I2C_DTT_ADDR:
2590 If defined, specifies the I2C address of the DTT device.
2591 If not defined, then U-Boot uses predefined value for
2592 specified DTT device.
2594 CONFIG_SOFT_I2C_READ_REPEATED_START
2596 defining this will force the i2c_read() function in
2597 the soft_i2c driver to perform an I2C repeated start
2598 between writing the address pointer and reading the
2599 data. If this define is omitted the default behaviour
2600 of doing a stop-start sequence will be used. Most I2C
2601 devices can use either method, but some require one or
2604 - SPI Support: CONFIG_SPI
2606 Enables SPI driver (so far only tested with
2607 SPI EEPROM, also an instance works with Crystal A/D and
2608 D/As on the SACSng board)
2612 Enables the driver for SPI controller on SuperH. Currently
2613 only SH7757 is supported.
2617 Enables extended (16-bit) SPI EEPROM addressing.
2618 (symmetrical to CONFIG_I2C_X)
2622 Enables a software (bit-bang) SPI driver rather than
2623 using hardware support. This is a general purpose
2624 driver that only requires three general I/O port pins
2625 (two outputs, one input) to function. If this is
2626 defined, the board configuration must define several
2627 SPI configuration items (port pins to use, etc). For
2628 an example, see include/configs/sacsng.h.
2632 Enables a hardware SPI driver for general-purpose reads
2633 and writes. As with CONFIG_SOFT_SPI, the board configuration
2634 must define a list of chip-select function pointers.
2635 Currently supported on some MPC8xxx processors. For an
2636 example, see include/configs/mpc8349emds.h.
2640 Enables the driver for the SPI controllers on i.MX and MXC
2641 SoCs. Currently i.MX31/35/51 are supported.
2643 CONFIG_SYS_SPI_MXC_WAIT
2644 Timeout for waiting until spi transfer completed.
2645 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2647 - FPGA Support: CONFIG_FPGA
2649 Enables FPGA subsystem.
2651 CONFIG_FPGA_<vendor>
2653 Enables support for specific chip vendors.
2656 CONFIG_FPGA_<family>
2658 Enables support for FPGA family.
2659 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2663 Specify the number of FPGA devices to support.
2665 CONFIG_CMD_FPGA_LOADMK
2667 Enable support for fpga loadmk command
2669 CONFIG_CMD_FPGA_LOADP
2671 Enable support for fpga loadp command - load partial bitstream
2673 CONFIG_CMD_FPGA_LOADBP
2675 Enable support for fpga loadbp command - load partial bitstream
2678 CONFIG_SYS_FPGA_PROG_FEEDBACK
2680 Enable printing of hash marks during FPGA configuration.
2682 CONFIG_SYS_FPGA_CHECK_BUSY
2684 Enable checks on FPGA configuration interface busy
2685 status by the configuration function. This option
2686 will require a board or device specific function to
2691 If defined, a function that provides delays in the FPGA
2692 configuration driver.
2694 CONFIG_SYS_FPGA_CHECK_CTRLC
2695 Allow Control-C to interrupt FPGA configuration
2697 CONFIG_SYS_FPGA_CHECK_ERROR
2699 Check for configuration errors during FPGA bitfile
2700 loading. For example, abort during Virtex II
2701 configuration if the INIT_B line goes low (which
2702 indicated a CRC error).
2704 CONFIG_SYS_FPGA_WAIT_INIT
2706 Maximum time to wait for the INIT_B line to deassert
2707 after PROB_B has been deasserted during a Virtex II
2708 FPGA configuration sequence. The default time is 500
2711 CONFIG_SYS_FPGA_WAIT_BUSY
2713 Maximum time to wait for BUSY to deassert during
2714 Virtex II FPGA configuration. The default is 5 ms.
2716 CONFIG_SYS_FPGA_WAIT_CONFIG
2718 Time to wait after FPGA configuration. The default is
2721 - Configuration Management:
2724 Some SoCs need special image types (e.g. U-Boot binary
2725 with a special header) as build targets. By defining
2726 CONFIG_BUILD_TARGET in the SoC / board header, this
2727 special image will be automatically built upon calling
2732 If defined, this string will be added to the U-Boot
2733 version information (U_BOOT_VERSION)
2735 - Vendor Parameter Protection:
2737 U-Boot considers the values of the environment
2738 variables "serial#" (Board Serial Number) and
2739 "ethaddr" (Ethernet Address) to be parameters that
2740 are set once by the board vendor / manufacturer, and
2741 protects these variables from casual modification by
2742 the user. Once set, these variables are read-only,
2743 and write or delete attempts are rejected. You can
2744 change this behaviour:
2746 If CONFIG_ENV_OVERWRITE is #defined in your config
2747 file, the write protection for vendor parameters is
2748 completely disabled. Anybody can change or delete
2751 Alternatively, if you #define _both_ CONFIG_ETHADDR
2752 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2753 Ethernet address is installed in the environment,
2754 which can be changed exactly ONCE by the user. [The
2755 serial# is unaffected by this, i. e. it remains
2758 The same can be accomplished in a more flexible way
2759 for any variable by configuring the type of access
2760 to allow for those variables in the ".flags" variable
2761 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2766 Define this variable to enable the reservation of
2767 "protected RAM", i. e. RAM which is not overwritten
2768 by U-Boot. Define CONFIG_PRAM to hold the number of
2769 kB you want to reserve for pRAM. You can overwrite
2770 this default value by defining an environment
2771 variable "pram" to the number of kB you want to
2772 reserve. Note that the board info structure will
2773 still show the full amount of RAM. If pRAM is
2774 reserved, a new environment variable "mem" will
2775 automatically be defined to hold the amount of
2776 remaining RAM in a form that can be passed as boot
2777 argument to Linux, for instance like that:
2779 setenv bootargs ... mem=\${mem}
2782 This way you can tell Linux not to use this memory,
2783 either, which results in a memory region that will
2784 not be affected by reboots.
2786 *WARNING* If your board configuration uses automatic
2787 detection of the RAM size, you must make sure that
2788 this memory test is non-destructive. So far, the
2789 following board configurations are known to be
2792 IVMS8, IVML24, SPD8xx, TQM8xxL,
2793 HERMES, IP860, RPXlite, LWMON,
2796 - Access to physical memory region (> 4GB)
2797 Some basic support is provided for operations on memory not
2798 normally accessible to U-Boot - e.g. some architectures
2799 support access to more than 4GB of memory on 32-bit
2800 machines using physical address extension or similar.
2801 Define CONFIG_PHYSMEM to access this basic support, which
2802 currently only supports clearing the memory.
2807 Define this variable to stop the system in case of a
2808 fatal error, so that you have to reset it manually.
2809 This is probably NOT a good idea for an embedded
2810 system where you want the system to reboot
2811 automatically as fast as possible, but it may be
2812 useful during development since you can try to debug
2813 the conditions that lead to the situation.
2815 CONFIG_NET_RETRY_COUNT
2817 This variable defines the number of retries for
2818 network operations like ARP, RARP, TFTP, or BOOTP
2819 before giving up the operation. If not defined, a
2820 default value of 5 is used.
2824 Timeout waiting for an ARP reply in milliseconds.
2828 Timeout in milliseconds used in NFS protocol.
2829 If you encounter "ERROR: Cannot umount" in nfs command,
2830 try longer timeout such as
2831 #define CONFIG_NFS_TIMEOUT 10000UL
2833 - Command Interpreter:
2834 CONFIG_AUTO_COMPLETE
2836 Enable auto completion of commands using TAB.
2838 CONFIG_SYS_HUSH_PARSER
2840 Define this variable to enable the "hush" shell (from
2841 Busybox) as command line interpreter, thus enabling
2842 powerful command line syntax like
2843 if...then...else...fi conditionals or `&&' and '||'
2844 constructs ("shell scripts").
2846 If undefined, you get the old, much simpler behaviour
2847 with a somewhat smaller memory footprint.
2850 CONFIG_SYS_PROMPT_HUSH_PS2
2852 This defines the secondary prompt string, which is
2853 printed when the command interpreter needs more input
2854 to complete a command. Usually "> ".
2858 In the current implementation, the local variables
2859 space and global environment variables space are
2860 separated. Local variables are those you define by
2861 simply typing `name=value'. To access a local
2862 variable later on, you have write `$name' or
2863 `${name}'; to execute the contents of a variable
2864 directly type `$name' at the command prompt.
2866 Global environment variables are those you use
2867 setenv/printenv to work with. To run a command stored
2868 in such a variable, you need to use the run command,
2869 and you must not use the '$' sign to access them.
2871 To store commands and special characters in a
2872 variable, please use double quotation marks
2873 surrounding the whole text of the variable, instead
2874 of the backslashes before semicolons and special
2877 - Commandline Editing and History:
2878 CONFIG_CMDLINE_EDITING
2880 Enable editing and History functions for interactive
2881 commandline input operations
2883 - Default Environment:
2884 CONFIG_EXTRA_ENV_SETTINGS
2886 Define this to contain any number of null terminated
2887 strings (variable = value pairs) that will be part of
2888 the default environment compiled into the boot image.
2890 For example, place something like this in your
2891 board's config file:
2893 #define CONFIG_EXTRA_ENV_SETTINGS \
2897 Warning: This method is based on knowledge about the
2898 internal format how the environment is stored by the
2899 U-Boot code. This is NOT an official, exported
2900 interface! Although it is unlikely that this format
2901 will change soon, there is no guarantee either.
2902 You better know what you are doing here.
2904 Note: overly (ab)use of the default environment is
2905 discouraged. Make sure to check other ways to preset
2906 the environment like the "source" command or the
2909 CONFIG_ENV_VARS_UBOOT_CONFIG
2911 Define this in order to add variables describing the
2912 U-Boot build configuration to the default environment.
2913 These will be named arch, cpu, board, vendor, and soc.
2915 Enabling this option will cause the following to be defined:
2923 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2925 Define this in order to add variables describing certain
2926 run-time determined information about the hardware to the
2927 environment. These will be named board_name, board_rev.
2929 CONFIG_DELAY_ENVIRONMENT
2931 Normally the environment is loaded when the board is
2932 intialised so that it is available to U-Boot. This inhibits
2933 that so that the environment is not available until
2934 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2935 this is instead controlled by the value of
2936 /config/load-environment.
2938 - DataFlash Support:
2939 CONFIG_HAS_DATAFLASH
2941 Defining this option enables DataFlash features and
2942 allows to read/write in Dataflash via the standard
2945 - Serial Flash support
2948 Defining this option enables SPI flash commands
2949 'sf probe/read/write/erase/update'.
2951 Usage requires an initial 'probe' to define the serial
2952 flash parameters, followed by read/write/erase/update
2955 The following defaults may be provided by the platform
2956 to handle the common case when only a single serial
2957 flash is present on the system.
2959 CONFIG_SF_DEFAULT_BUS Bus identifier
2960 CONFIG_SF_DEFAULT_CS Chip-select
2961 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2962 CONFIG_SF_DEFAULT_SPEED in Hz
2966 Define this option to include a destructive SPI flash
2969 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2971 Define this option to use the Bank addr/Extended addr
2972 support on SPI flashes which has size > 16Mbytes.
2974 CONFIG_SF_DUAL_FLASH Dual flash memories
2976 Define this option to use dual flash support where two flash
2977 memories can be connected with a given cs line.
2978 currently Xilinx Zynq qspi support these type of connections.
2980 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
2981 enable the W#/Vpp signal to disable writing to the status
2982 register on ST MICRON flashes like the N25Q128.
2983 The status register write enable/disable bit, combined with
2984 the W#/VPP signal provides hardware data protection for the
2985 device as follows: When the enable/disable bit is set to 1,
2986 and the W#/VPP signal is driven LOW, the status register
2987 nonvolatile bits become read-only and the WRITE STATUS REGISTER
2988 operation will not execute. The only way to exit this
2989 hardware-protected mode is to drive W#/VPP HIGH.
2991 - SystemACE Support:
2994 Adding this option adds support for Xilinx SystemACE
2995 chips attached via some sort of local bus. The address
2996 of the chip must also be defined in the
2997 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2999 #define CONFIG_SYSTEMACE
3000 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3002 When SystemACE support is added, the "ace" device type
3003 becomes available to the fat commands, i.e. fatls.
3005 - TFTP Fixed UDP Port:
3008 If this is defined, the environment variable tftpsrcp
3009 is used to supply the TFTP UDP source port value.
3010 If tftpsrcp isn't defined, the normal pseudo-random port
3011 number generator is used.
3013 Also, the environment variable tftpdstp is used to supply
3014 the TFTP UDP destination port value. If tftpdstp isn't
3015 defined, the normal port 69 is used.
3017 The purpose for tftpsrcp is to allow a TFTP server to
3018 blindly start the TFTP transfer using the pre-configured
3019 target IP address and UDP port. This has the effect of
3020 "punching through" the (Windows XP) firewall, allowing
3021 the remainder of the TFTP transfer to proceed normally.
3022 A better solution is to properly configure the firewall,
3023 but sometimes that is not allowed.
3028 This enables a generic 'hash' command which can produce
3029 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3033 Enable the hash verify command (hash -v). This adds to code
3036 CONFIG_SHA1 - support SHA1 hashing
3037 CONFIG_SHA256 - support SHA256 hashing
3039 Note: There is also a sha1sum command, which should perhaps
3040 be deprecated in favour of 'hash sha1'.
3042 - Freescale i.MX specific commands:
3043 CONFIG_CMD_HDMIDETECT
3044 This enables 'hdmidet' command which returns true if an
3045 HDMI monitor is detected. This command is i.MX 6 specific.
3048 This enables the 'bmode' (bootmode) command for forcing
3049 a boot from specific media.
3051 This is useful for forcing the ROM's usb downloader to
3052 activate upon a watchdog reset which is nice when iterating
3053 on U-Boot. Using the reset button or running bmode normal
3054 will set it back to normal. This command currently
3055 supports i.MX53 and i.MX6.
3060 This enables the RSA algorithm used for FIT image verification
3061 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3063 The signing part is build into mkimage regardless of this
3066 - bootcount support:
3067 CONFIG_BOOTCOUNT_LIMIT
3069 This enables the bootcounter support, see:
3070 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3073 enable special bootcounter support on at91sam9xe based boards.
3075 enable special bootcounter support on blackfin based boards.
3077 enable special bootcounter support on da850 based boards.
3078 CONFIG_BOOTCOUNT_RAM
3079 enable support for the bootcounter in RAM
3080 CONFIG_BOOTCOUNT_I2C
3081 enable support for the bootcounter on an i2c (like RTC) device.
3082 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3083 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3085 CONFIG_BOOTCOUNT_ALEN = address len
3087 - Show boot progress:
3088 CONFIG_SHOW_BOOT_PROGRESS
3090 Defining this option allows to add some board-
3091 specific code (calling a user-provided function
3092 "show_boot_progress(int)") that enables you to show
3093 the system's boot progress on some display (for
3094 example, some LED's) on your board. At the moment,
3095 the following checkpoints are implemented:
3097 - Detailed boot stage timing
3099 Define this option to get detailed timing of each stage
3100 of the boot process.
3102 CONFIG_BOOTSTAGE_USER_COUNT
3103 This is the number of available user bootstage records.
3104 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3105 a new ID will be allocated from this stash. If you exceed
3106 the limit, recording will stop.
3108 CONFIG_BOOTSTAGE_REPORT
3109 Define this to print a report before boot, similar to this:
3111 Timer summary in microseconds:
3114 3,575,678 3,575,678 board_init_f start
3115 3,575,695 17 arch_cpu_init A9
3116 3,575,777 82 arch_cpu_init done
3117 3,659,598 83,821 board_init_r start
3118 3,910,375 250,777 main_loop
3119 29,916,167 26,005,792 bootm_start
3120 30,361,327 445,160 start_kernel
3122 CONFIG_CMD_BOOTSTAGE
3123 Add a 'bootstage' command which supports printing a report
3124 and un/stashing of bootstage data.
3126 CONFIG_BOOTSTAGE_FDT
3127 Stash the bootstage information in the FDT. A root 'bootstage'
3128 node is created with each bootstage id as a child. Each child
3129 has a 'name' property and either 'mark' containing the
3130 mark time in microsecond, or 'accum' containing the
3131 accumulated time for that bootstage id in microseconds.
3136 name = "board_init_f";
3145 Code in the Linux kernel can find this in /proc/devicetree.
3147 Legacy uImage format:
3150 1 common/cmd_bootm.c before attempting to boot an image
3151 -1 common/cmd_bootm.c Image header has bad magic number
3152 2 common/cmd_bootm.c Image header has correct magic number
3153 -2 common/cmd_bootm.c Image header has bad checksum
3154 3 common/cmd_bootm.c Image header has correct checksum
3155 -3 common/cmd_bootm.c Image data has bad checksum
3156 4 common/cmd_bootm.c Image data has correct checksum
3157 -4 common/cmd_bootm.c Image is for unsupported architecture
3158 5 common/cmd_bootm.c Architecture check OK
3159 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3160 6 common/cmd_bootm.c Image Type check OK
3161 -6 common/cmd_bootm.c gunzip uncompression error
3162 -7 common/cmd_bootm.c Unimplemented compression type
3163 7 common/cmd_bootm.c Uncompression OK
3164 8 common/cmd_bootm.c No uncompress/copy overwrite error
3165 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3167 9 common/image.c Start initial ramdisk verification
3168 -10 common/image.c Ramdisk header has bad magic number
3169 -11 common/image.c Ramdisk header has bad checksum
3170 10 common/image.c Ramdisk header is OK
3171 -12 common/image.c Ramdisk data has bad checksum
3172 11 common/image.c Ramdisk data has correct checksum
3173 12 common/image.c Ramdisk verification complete, start loading
3174 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3175 13 common/image.c Start multifile image verification
3176 14 common/image.c No initial ramdisk, no multifile, continue.
3178 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3180 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3181 -31 post/post.c POST test failed, detected by post_output_backlog()
3182 -32 post/post.c POST test failed, detected by post_run_single()
3184 34 common/cmd_doc.c before loading a Image from a DOC device
3185 -35 common/cmd_doc.c Bad usage of "doc" command
3186 35 common/cmd_doc.c correct usage of "doc" command
3187 -36 common/cmd_doc.c No boot device
3188 36 common/cmd_doc.c correct boot device
3189 -37 common/cmd_doc.c Unknown Chip ID on boot device
3190 37 common/cmd_doc.c correct chip ID found, device available
3191 -38 common/cmd_doc.c Read Error on boot device
3192 38 common/cmd_doc.c reading Image header from DOC device OK
3193 -39 common/cmd_doc.c Image header has bad magic number
3194 39 common/cmd_doc.c Image header has correct magic number
3195 -40 common/cmd_doc.c Error reading Image from DOC device
3196 40 common/cmd_doc.c Image header has correct magic number
3197 41 common/cmd_ide.c before loading a Image from a IDE device
3198 -42 common/cmd_ide.c Bad usage of "ide" command
3199 42 common/cmd_ide.c correct usage of "ide" command
3200 -43 common/cmd_ide.c No boot device
3201 43 common/cmd_ide.c boot device found
3202 -44 common/cmd_ide.c Device not available
3203 44 common/cmd_ide.c Device available
3204 -45 common/cmd_ide.c wrong partition selected
3205 45 common/cmd_ide.c partition selected
3206 -46 common/cmd_ide.c Unknown partition table
3207 46 common/cmd_ide.c valid partition table found
3208 -47 common/cmd_ide.c Invalid partition type
3209 47 common/cmd_ide.c correct partition type
3210 -48 common/cmd_ide.c Error reading Image Header on boot device
3211 48 common/cmd_ide.c reading Image Header from IDE device OK
3212 -49 common/cmd_ide.c Image header has bad magic number
3213 49 common/cmd_ide.c Image header has correct magic number
3214 -50 common/cmd_ide.c Image header has bad checksum
3215 50 common/cmd_ide.c Image header has correct checksum
3216 -51 common/cmd_ide.c Error reading Image from IDE device
3217 51 common/cmd_ide.c reading Image from IDE device OK
3218 52 common/cmd_nand.c before loading a Image from a NAND device
3219 -53 common/cmd_nand.c Bad usage of "nand" command
3220 53 common/cmd_nand.c correct usage of "nand" command
3221 -54 common/cmd_nand.c No boot device
3222 54 common/cmd_nand.c boot device found
3223 -55 common/cmd_nand.c Unknown Chip ID on boot device
3224 55 common/cmd_nand.c correct chip ID found, device available
3225 -56 common/cmd_nand.c Error reading Image Header on boot device
3226 56 common/cmd_nand.c reading Image Header from NAND device OK
3227 -57 common/cmd_nand.c Image header has bad magic number
3228 57 common/cmd_nand.c Image header has correct magic number
3229 -58 common/cmd_nand.c Error reading Image from NAND device
3230 58 common/cmd_nand.c reading Image from NAND device OK
3232 -60 common/env_common.c Environment has a bad CRC, using default
3234 64 net/eth.c starting with Ethernet configuration.
3235 -64 net/eth.c no Ethernet found.
3236 65 net/eth.c Ethernet found.
3238 -80 common/cmd_net.c usage wrong
3239 80 common/cmd_net.c before calling NetLoop()
3240 -81 common/cmd_net.c some error in NetLoop() occurred
3241 81 common/cmd_net.c NetLoop() back without error
3242 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3243 82 common/cmd_net.c trying automatic boot
3244 83 common/cmd_net.c running "source" command
3245 -83 common/cmd_net.c some error in automatic boot or "source" command
3246 84 common/cmd_net.c end without errors
3251 100 common/cmd_bootm.c Kernel FIT Image has correct format
3252 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3253 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3254 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3255 102 common/cmd_bootm.c Kernel unit name specified
3256 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3257 103 common/cmd_bootm.c Found configuration node
3258 104 common/cmd_bootm.c Got kernel subimage node offset
3259 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3260 105 common/cmd_bootm.c Kernel subimage hash verification OK
3261 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3262 106 common/cmd_bootm.c Architecture check OK
3263 -106 common/cmd_bootm.c Kernel subimage has wrong type
3264 107 common/cmd_bootm.c Kernel subimage type OK
3265 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3266 108 common/cmd_bootm.c Got kernel subimage data/size
3267 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3268 -109 common/cmd_bootm.c Can't get kernel subimage type
3269 -110 common/cmd_bootm.c Can't get kernel subimage comp
3270 -111 common/cmd_bootm.c Can't get kernel subimage os
3271 -112 common/cmd_bootm.c Can't get kernel subimage load address
3272 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3274 120 common/image.c Start initial ramdisk verification
3275 -120 common/image.c Ramdisk FIT image has incorrect format
3276 121 common/image.c Ramdisk FIT image has correct format
3277 122 common/image.c No ramdisk subimage unit name, using configuration
3278 -122 common/image.c Can't get configuration for ramdisk subimage
3279 123 common/image.c Ramdisk unit name specified
3280 -124 common/image.c Can't get ramdisk subimage node offset
3281 125 common/image.c Got ramdisk subimage node offset
3282 -125 common/image.c Ramdisk subimage hash verification failed
3283 126 common/image.c Ramdisk subimage hash verification OK
3284 -126 common/image.c Ramdisk subimage for unsupported architecture
3285 127 common/image.c Architecture check OK
3286 -127 common/image.c Can't get ramdisk subimage data/size
3287 128 common/image.c Got ramdisk subimage data/size
3288 129 common/image.c Can't get ramdisk load address
3289 -129 common/image.c Got ramdisk load address
3291 -130 common/cmd_doc.c Incorrect FIT image format
3292 131 common/cmd_doc.c FIT image format OK
3294 -140 common/cmd_ide.c Incorrect FIT image format
3295 141 common/cmd_ide.c FIT image format OK
3297 -150 common/cmd_nand.c Incorrect FIT image format
3298 151 common/cmd_nand.c FIT image format OK
3300 - legacy image format:
3301 CONFIG_IMAGE_FORMAT_LEGACY
3302 enables the legacy image format support in U-Boot.
3305 enabled if CONFIG_FIT_SIGNATURE is not defined.
3307 CONFIG_DISABLE_IMAGE_LEGACY
3308 disable the legacy image format
3310 This define is introduced, as the legacy image format is
3311 enabled per default for backward compatibility.
3313 - FIT image support:
3315 Enable support for the FIT uImage format.
3317 CONFIG_FIT_BEST_MATCH
3318 When no configuration is explicitly selected, default to the
3319 one whose fdt's compatibility field best matches that of
3320 U-Boot itself. A match is considered "best" if it matches the
3321 most specific compatibility entry of U-Boot's fdt's root node.
3322 The order of entries in the configuration's fdt is ignored.
3324 CONFIG_FIT_SIGNATURE
3325 This option enables signature verification of FIT uImages,
3326 using a hash signed and verified using RSA. See
3327 doc/uImage.FIT/signature.txt for more details.
3329 WARNING: When relying on signed FIT images with required
3330 signature check the legacy image format is default
3331 disabled. If a board need legacy image format support
3332 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3334 CONFIG_FIT_DISABLE_SHA256
3335 Supporting SHA256 hashes has quite an impact on binary size.
3336 For constrained systems sha256 hash support can be disabled
3339 - Standalone program support:
3340 CONFIG_STANDALONE_LOAD_ADDR
3342 This option defines a board specific value for the
3343 address where standalone program gets loaded, thus
3344 overwriting the architecture dependent default
3347 - Frame Buffer Address:
3350 Define CONFIG_FB_ADDR if you want to use specific
3351 address for frame buffer. This is typically the case
3352 when using a graphics controller has separate video
3353 memory. U-Boot will then place the frame buffer at
3354 the given address instead of dynamically reserving it
3355 in system RAM by calling lcd_setmem(), which grabs
3356 the memory for the frame buffer depending on the
3357 configured panel size.
3359 Please see board_init_f function.
3361 - Automatic software updates via TFTP server
3363 CONFIG_UPDATE_TFTP_CNT_MAX
3364 CONFIG_UPDATE_TFTP_MSEC_MAX
3366 These options enable and control the auto-update feature;
3367 for a more detailed description refer to doc/README.update.
3369 - MTD Support (mtdparts command, UBI support)
3372 Adds the MTD device infrastructure from the Linux kernel.
3373 Needed for mtdparts command support.
3375 CONFIG_MTD_PARTITIONS
3377 Adds the MTD partitioning infrastructure from the Linux
3378 kernel. Needed for UBI support.
3380 CONFIG_MTD_NAND_VERIFY_WRITE
3381 verify if the written data is correct reread.
3386 Adds commands for interacting with MTD partitions formatted
3387 with the UBI flash translation layer
3389 Requires also defining CONFIG_RBTREE
3391 CONFIG_UBI_SILENCE_MSG
3393 Make the verbose messages from UBI stop printing. This leaves
3394 warnings and errors enabled.
3397 CONFIG_MTD_UBI_WL_THRESHOLD
3398 This parameter defines the maximum difference between the highest
3399 erase counter value and the lowest erase counter value of eraseblocks
3400 of UBI devices. When this threshold is exceeded, UBI starts performing
3401 wear leveling by means of moving data from eraseblock with low erase
3402 counter to eraseblocks with high erase counter.
3404 The default value should be OK for SLC NAND flashes, NOR flashes and
3405 other flashes which have eraseblock life-cycle 100000 or more.
3406 However, in case of MLC NAND flashes which typically have eraseblock
3407 life-cycle less than 10000, the threshold should be lessened (e.g.,
3408 to 128 or 256, although it does not have to be power of 2).
3412 CONFIG_MTD_UBI_BEB_LIMIT
3413 This option specifies the maximum bad physical eraseblocks UBI
3414 expects on the MTD device (per 1024 eraseblocks). If the
3415 underlying flash does not admit of bad eraseblocks (e.g. NOR
3416 flash), this value is ignored.
3418 NAND datasheets often specify the minimum and maximum NVM
3419 (Number of Valid Blocks) for the flashes' endurance lifetime.
3420 The maximum expected bad eraseblocks per 1024 eraseblocks
3421 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3422 which gives 20 for most NANDs (MaxNVB is basically the total
3423 count of eraseblocks on the chip).
3425 To put it differently, if this value is 20, UBI will try to
3426 reserve about 1.9% of physical eraseblocks for bad blocks
3427 handling. And that will be 1.9% of eraseblocks on the entire
3428 NAND chip, not just the MTD partition UBI attaches. This means
3429 that if you have, say, a NAND flash chip admits maximum 40 bad
3430 eraseblocks, and it is split on two MTD partitions of the same
3431 size, UBI will reserve 40 eraseblocks when attaching a
3436 CONFIG_MTD_UBI_FASTMAP
3437 Fastmap is a mechanism which allows attaching an UBI device
3438 in nearly constant time. Instead of scanning the whole MTD device it
3439 only has to locate a checkpoint (called fastmap) on the device.
3440 The on-flash fastmap contains all information needed to attach
3441 the device. Using fastmap makes only sense on large devices where
3442 attaching by scanning takes long. UBI will not automatically install
3443 a fastmap on old images, but you can set the UBI parameter
3444 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3445 that fastmap-enabled images are still usable with UBI implementations
3446 without fastmap support. On typical flash devices the whole fastmap
3447 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3449 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3450 Set this parameter to enable fastmap automatically on images
3457 Adds commands for interacting with UBI volumes formatted as
3458 UBIFS. UBIFS is read-only in u-boot.
3460 Requires UBI support as well as CONFIG_LZO
3462 CONFIG_UBIFS_SILENCE_MSG
3464 Make the verbose messages from UBIFS stop printing. This leaves
3465 warnings and errors enabled.
3469 Enable building of SPL globally.
3472 LDSCRIPT for linking the SPL binary.
3474 CONFIG_SPL_MAX_FOOTPRINT
3475 Maximum size in memory allocated to the SPL, BSS included.
3476 When defined, the linker checks that the actual memory
3477 used by SPL from _start to __bss_end does not exceed it.
3478 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3479 must not be both defined at the same time.
3482 Maximum size of the SPL image (text, data, rodata, and
3483 linker lists sections), BSS excluded.
3484 When defined, the linker checks that the actual size does
3487 CONFIG_SPL_TEXT_BASE
3488 TEXT_BASE for linking the SPL binary.
3490 CONFIG_SPL_RELOC_TEXT_BASE
3491 Address to relocate to. If unspecified, this is equal to
3492 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3494 CONFIG_SPL_BSS_START_ADDR
3495 Link address for the BSS within the SPL binary.
3497 CONFIG_SPL_BSS_MAX_SIZE
3498 Maximum size in memory allocated to the SPL BSS.
3499 When defined, the linker checks that the actual memory used
3500 by SPL from __bss_start to __bss_end does not exceed it.
3501 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3502 must not be both defined at the same time.
3505 Adress of the start of the stack SPL will use
3507 CONFIG_SPL_RELOC_STACK
3508 Adress of the start of the stack SPL will use after
3509 relocation. If unspecified, this is equal to
3512 CONFIG_SYS_SPL_MALLOC_START
3513 Starting address of the malloc pool used in SPL.
3515 CONFIG_SYS_SPL_MALLOC_SIZE
3516 The size of the malloc pool used in SPL.
3518 CONFIG_SPL_FRAMEWORK
3519 Enable the SPL framework under common/. This framework
3520 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3521 NAND loading of the Linux Kernel.
3524 Enable booting directly to an OS from SPL.
3525 See also: doc/README.falcon
3527 CONFIG_SPL_DISPLAY_PRINT
3528 For ARM, enable an optional function to print more information
3529 about the running system.
3531 CONFIG_SPL_INIT_MINIMAL
3532 Arch init code should be built for a very small image
3534 CONFIG_SPL_LIBCOMMON_SUPPORT
3535 Support for common/libcommon.o in SPL binary
3537 CONFIG_SPL_LIBDISK_SUPPORT
3538 Support for disk/libdisk.o in SPL binary
3540 CONFIG_SPL_I2C_SUPPORT
3541 Support for drivers/i2c/libi2c.o in SPL binary
3543 CONFIG_SPL_GPIO_SUPPORT
3544 Support for drivers/gpio/libgpio.o in SPL binary
3546 CONFIG_SPL_MMC_SUPPORT
3547 Support for drivers/mmc/libmmc.o in SPL binary
3549 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3550 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3551 CONFIG_SYS_MMC_SD_FS_BOOT_PARTITION
3552 Address, size and partition on the MMC to load U-Boot from
3553 when the MMC is being used in raw mode.
3555 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3556 Sector to load kernel uImage from when MMC is being
3557 used in raw mode (for Falcon mode)
3559 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3560 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3561 Sector and number of sectors to load kernel argument
3562 parameters from when MMC is being used in raw mode
3565 CONFIG_SPL_FAT_SUPPORT
3566 Support for fs/fat/libfat.o in SPL binary
3568 CONFIG_SPL_EXT_SUPPORT
3569 Support for EXT filesystem in SPL binary
3571 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3572 Filename to read to load U-Boot when reading from filesystem
3574 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3575 Filename to read to load kernel uImage when reading
3576 from filesystem (for Falcon mode)
3578 CONFIG_SPL_FS_LOAD_ARGS_NAME
3579 Filename to read to load kernel argument parameters
3580 when reading from filesystem (for Falcon mode)
3582 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3583 Set this for NAND SPL on PPC mpc83xx targets, so that
3584 start.S waits for the rest of the SPL to load before
3585 continuing (the hardware starts execution after just
3586 loading the first page rather than the full 4K).
3588 CONFIG_SPL_SKIP_RELOCATE
3589 Avoid SPL relocation
3591 CONFIG_SPL_NAND_BASE
3592 Include nand_base.c in the SPL. Requires
3593 CONFIG_SPL_NAND_DRIVERS.
3595 CONFIG_SPL_NAND_DRIVERS
3596 SPL uses normal NAND drivers, not minimal drivers.
3599 Include standard software ECC in the SPL
3601 CONFIG_SPL_NAND_SIMPLE
3602 Support for NAND boot using simple NAND drivers that
3603 expose the cmd_ctrl() interface.
3605 CONFIG_SPL_MTD_SUPPORT
3606 Support for the MTD subsystem within SPL. Useful for
3607 environment on NAND support within SPL.
3609 CONFIG_SPL_NAND_RAW_ONLY
3610 Support to boot only raw u-boot.bin images. Use this only
3611 if you need to save space.
3613 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3614 Set for the SPL on PPC mpc8xxx targets, support for
3615 drivers/ddr/fsl/libddr.o in SPL binary.
3617 CONFIG_SPL_COMMON_INIT_DDR
3618 Set for common ddr init with serial presence detect in
3621 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3622 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3623 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3624 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3625 CONFIG_SYS_NAND_ECCBYTES
3626 Defines the size and behavior of the NAND that SPL uses
3629 CONFIG_SPL_NAND_BOOT
3630 Add support NAND boot
3632 CONFIG_SYS_NAND_U_BOOT_OFFS
3633 Location in NAND to read U-Boot from
3635 CONFIG_SYS_NAND_U_BOOT_DST
3636 Location in memory to load U-Boot to
3638 CONFIG_SYS_NAND_U_BOOT_SIZE
3639 Size of image to load
3641 CONFIG_SYS_NAND_U_BOOT_START
3642 Entry point in loaded image to jump to
3644 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3645 Define this if you need to first read the OOB and then the
3646 data. This is used for example on davinci plattforms.
3648 CONFIG_SPL_OMAP3_ID_NAND
3649 Support for an OMAP3-specific set of functions to return the
3650 ID and MFR of the first attached NAND chip, if present.
3652 CONFIG_SPL_SERIAL_SUPPORT
3653 Support for drivers/serial/libserial.o in SPL binary
3655 CONFIG_SPL_SPI_FLASH_SUPPORT
3656 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3658 CONFIG_SPL_SPI_SUPPORT
3659 Support for drivers/spi/libspi.o in SPL binary
3661 CONFIG_SPL_RAM_DEVICE
3662 Support for running image already present in ram, in SPL binary
3664 CONFIG_SPL_LIBGENERIC_SUPPORT
3665 Support for lib/libgeneric.o in SPL binary
3667 CONFIG_SPL_ENV_SUPPORT
3668 Support for the environment operating in SPL binary
3670 CONFIG_SPL_NET_SUPPORT
3671 Support for the net/libnet.o in SPL binary.
3672 It conflicts with SPL env from storage medium specified by
3673 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3676 Image offset to which the SPL should be padded before appending
3677 the SPL payload. By default, this is defined as
3678 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3679 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3680 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3683 Final target image containing SPL and payload. Some SPLs
3684 use an arch-specific makefile fragment instead, for
3685 example if more than one image needs to be produced.
3687 CONFIG_FIT_SPL_PRINT
3688 Printing information about a FIT image adds quite a bit of
3689 code to SPL. So this is normally disabled in SPL. Use this
3690 option to re-enable it. This will affect the output of the
3691 bootm command when booting a FIT image.
3695 Enable building of TPL globally.
3698 Image offset to which the TPL should be padded before appending
3699 the TPL payload. By default, this is defined as
3700 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3701 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3702 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3707 [so far only for SMDK2400 boards]
3709 - Modem support enable:
3710 CONFIG_MODEM_SUPPORT
3712 - RTS/CTS Flow control enable:
3715 - Modem debug support:
3716 CONFIG_MODEM_SUPPORT_DEBUG
3718 Enables debugging stuff (char screen[1024], dbg())
3719 for modem support. Useful only with BDI2000.
3721 - Interrupt support (PPC):
3723 There are common interrupt_init() and timer_interrupt()
3724 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3725 for CPU specific initialization. interrupt_init_cpu()
3726 should set decrementer_count to appropriate value. If
3727 CPU resets decrementer automatically after interrupt
3728 (ppc4xx) it should set decrementer_count to zero.
3729 timer_interrupt() calls timer_interrupt_cpu() for CPU
3730 specific handling. If board has watchdog / status_led
3731 / other_activity_monitor it works automatically from
3732 general timer_interrupt().
3736 In the target system modem support is enabled when a
3737 specific key (key combination) is pressed during
3738 power-on. Otherwise U-Boot will boot normally
3739 (autoboot). The key_pressed() function is called from
3740 board_init(). Currently key_pressed() is a dummy
3741 function, returning 1 and thus enabling modem
3744 If there are no modem init strings in the
3745 environment, U-Boot proceed to autoboot; the
3746 previous output (banner, info printfs) will be
3749 See also: doc/README.Modem
3751 Board initialization settings:
3752 ------------------------------
3754 During Initialization u-boot calls a number of board specific functions
3755 to allow the preparation of board specific prerequisites, e.g. pin setup
3756 before drivers are initialized. To enable these callbacks the
3757 following configuration macros have to be defined. Currently this is
3758 architecture specific, so please check arch/your_architecture/lib/board.c
3759 typically in board_init_f() and board_init_r().
3761 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3762 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3763 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3764 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3766 Configuration Settings:
3767 -----------------------
3769 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3770 Optionally it can be defined to support 64-bit memory commands.
3772 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3773 undefine this when you're short of memory.
3775 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3776 width of the commands listed in the 'help' command output.
3778 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3779 prompt for user input.
3781 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3783 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3785 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3787 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3788 the application (usually a Linux kernel) when it is
3791 - CONFIG_SYS_BAUDRATE_TABLE:
3792 List of legal baudrate settings for this board.
3794 - CONFIG_SYS_CONSOLE_INFO_QUIET
3795 Suppress display of console information at boot.
3797 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3798 If the board specific function
3799 extern int overwrite_console (void);
3800 returns 1, the stdin, stderr and stdout are switched to the
3801 serial port, else the settings in the environment are used.
3803 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3804 Enable the call to overwrite_console().
3806 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3807 Enable overwrite of previous console environment settings.
3809 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3810 Begin and End addresses of the area used by the
3813 - CONFIG_SYS_ALT_MEMTEST:
3814 Enable an alternate, more extensive memory test.
3816 - CONFIG_SYS_MEMTEST_SCRATCH:
3817 Scratch address used by the alternate memory test
3818 You only need to set this if address zero isn't writeable
3820 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3821 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3822 this specified memory area will get subtracted from the top
3823 (end) of RAM and won't get "touched" at all by U-Boot. By
3824 fixing up gd->ram_size the Linux kernel should gets passed
3825 the now "corrected" memory size and won't touch it either.
3826 This should work for arch/ppc and arch/powerpc. Only Linux
3827 board ports in arch/powerpc with bootwrapper support that
3828 recalculate the memory size from the SDRAM controller setup
3829 will have to get fixed in Linux additionally.
3831 This option can be used as a workaround for the 440EPx/GRx
3832 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3835 WARNING: Please make sure that this value is a multiple of
3836 the Linux page size (normally 4k). If this is not the case,
3837 then the end address of the Linux memory will be located at a
3838 non page size aligned address and this could cause major
3841 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3842 Enable temporary baudrate change while serial download
3844 - CONFIG_SYS_SDRAM_BASE:
3845 Physical start address of SDRAM. _Must_ be 0 here.
3847 - CONFIG_SYS_MBIO_BASE:
3848 Physical start address of Motherboard I/O (if using a
3851 - CONFIG_SYS_FLASH_BASE:
3852 Physical start address of Flash memory.
3854 - CONFIG_SYS_MONITOR_BASE:
3855 Physical start address of boot monitor code (set by
3856 make config files to be same as the text base address
3857 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3858 CONFIG_SYS_FLASH_BASE when booting from flash.
3860 - CONFIG_SYS_MONITOR_LEN:
3861 Size of memory reserved for monitor code, used to
3862 determine _at_compile_time_ (!) if the environment is
3863 embedded within the U-Boot image, or in a separate
3866 - CONFIG_SYS_MALLOC_LEN:
3867 Size of DRAM reserved for malloc() use.
3869 - CONFIG_SYS_MALLOC_F_LEN
3870 Size of the malloc() pool for use before relocation. If
3871 this is defined, then a very simple malloc() implementation
3872 will become available before relocation. The address is just
3873 below the global data, and the stack is moved down to make
3876 This feature allocates regions with increasing addresses
3877 within the region. calloc() is supported, but realloc()
3878 is not available. free() is supported but does nothing.
3879 The memory will be freed (or in fact just forgotton) when
3880 U-Boot relocates itself.
3882 Pre-relocation malloc() is only supported on ARM and sandbox
3883 at present but is fairly easy to enable for other archs.
3885 - CONFIG_SYS_BOOTM_LEN:
3886 Normally compressed uImages are limited to an
3887 uncompressed size of 8 MBytes. If this is not enough,
3888 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3889 to adjust this setting to your needs.
3891 - CONFIG_SYS_BOOTMAPSZ:
3892 Maximum size of memory mapped by the startup code of
3893 the Linux kernel; all data that must be processed by
3894 the Linux kernel (bd_info, boot arguments, FDT blob if
3895 used) must be put below this limit, unless "bootm_low"
3896 environment variable is defined and non-zero. In such case
3897 all data for the Linux kernel must be between "bootm_low"
3898 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3899 variable "bootm_mapsize" will override the value of
3900 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3901 then the value in "bootm_size" will be used instead.
3903 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3904 Enable initrd_high functionality. If defined then the
3905 initrd_high feature is enabled and the bootm ramdisk subcommand
3908 - CONFIG_SYS_BOOT_GET_CMDLINE:
3909 Enables allocating and saving kernel cmdline in space between
3910 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3912 - CONFIG_SYS_BOOT_GET_KBD:
3913 Enables allocating and saving a kernel copy of the bd_info in
3914 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3916 - CONFIG_SYS_MAX_FLASH_BANKS:
3917 Max number of Flash memory banks
3919 - CONFIG_SYS_MAX_FLASH_SECT:
3920 Max number of sectors on a Flash chip
3922 - CONFIG_SYS_FLASH_ERASE_TOUT:
3923 Timeout for Flash erase operations (in ms)
3925 - CONFIG_SYS_FLASH_WRITE_TOUT:
3926 Timeout for Flash write operations (in ms)
3928 - CONFIG_SYS_FLASH_LOCK_TOUT
3929 Timeout for Flash set sector lock bit operation (in ms)
3931 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3932 Timeout for Flash clear lock bits operation (in ms)
3934 - CONFIG_SYS_FLASH_PROTECTION
3935 If defined, hardware flash sectors protection is used
3936 instead of U-Boot software protection.
3938 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3940 Enable TFTP transfers directly to flash memory;
3941 without this option such a download has to be
3942 performed in two steps: (1) download to RAM, and (2)
3943 copy from RAM to flash.
3945 The two-step approach is usually more reliable, since
3946 you can check if the download worked before you erase
3947 the flash, but in some situations (when system RAM is
3948 too limited to allow for a temporary copy of the
3949 downloaded image) this option may be very useful.
3951 - CONFIG_SYS_FLASH_CFI:
3952 Define if the flash driver uses extra elements in the
3953 common flash structure for storing flash geometry.
3955 - CONFIG_FLASH_CFI_DRIVER
3956 This option also enables the building of the cfi_flash driver
3957 in the drivers directory
3959 - CONFIG_FLASH_CFI_MTD
3960 This option enables the building of the cfi_mtd driver
3961 in the drivers directory. The driver exports CFI flash
3964 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3965 Use buffered writes to flash.
3967 - CONFIG_FLASH_SPANSION_S29WS_N
3968 s29ws-n MirrorBit flash has non-standard addresses for buffered
3971 - CONFIG_SYS_FLASH_QUIET_TEST
3972 If this option is defined, the common CFI flash doesn't
3973 print it's warning upon not recognized FLASH banks. This
3974 is useful, if some of the configured banks are only
3975 optionally available.
3977 - CONFIG_FLASH_SHOW_PROGRESS
3978 If defined (must be an integer), print out countdown
3979 digits and dots. Recommended value: 45 (9..1) for 80
3980 column displays, 15 (3..1) for 40 column displays.
3982 - CONFIG_FLASH_VERIFY
3983 If defined, the content of the flash (destination) is compared
3984 against the source after the write operation. An error message
3985 will be printed when the contents are not identical.
3986 Please note that this option is useless in nearly all cases,
3987 since such flash programming errors usually are detected earlier
3988 while unprotecting/erasing/programming. Please only enable
3989 this option if you really know what you are doing.
3991 - CONFIG_SYS_RX_ETH_BUFFER:
3992 Defines the number of Ethernet receive buffers. On some
3993 Ethernet controllers it is recommended to set this value
3994 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3995 buffers can be full shortly after enabling the interface
3996 on high Ethernet traffic.
3997 Defaults to 4 if not defined.
3999 - CONFIG_ENV_MAX_ENTRIES
4001 Maximum number of entries in the hash table that is used
4002 internally to store the environment settings. The default
4003 setting is supposed to be generous and should work in most
4004 cases. This setting can be used to tune behaviour; see
4005 lib/hashtable.c for details.
4007 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4008 - CONFIG_ENV_FLAGS_LIST_STATIC
4009 Enable validation of the values given to environment variables when
4010 calling env set. Variables can be restricted to only decimal,
4011 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4012 the variables can also be restricted to IP address or MAC address.
4014 The format of the list is:
4015 type_attribute = [s|d|x|b|i|m]
4016 access_atribute = [a|r|o|c]
4017 attributes = type_attribute[access_atribute]
4018 entry = variable_name[:attributes]
4021 The type attributes are:
4022 s - String (default)
4025 b - Boolean ([1yYtT|0nNfF])
4029 The access attributes are:
4035 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4036 Define this to a list (string) to define the ".flags"
4037 envirnoment variable in the default or embedded environment.
4039 - CONFIG_ENV_FLAGS_LIST_STATIC
4040 Define this to a list (string) to define validation that
4041 should be done if an entry is not found in the ".flags"
4042 environment variable. To override a setting in the static
4043 list, simply add an entry for the same variable name to the
4046 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4047 If defined, don't allow the -f switch to env set override variable
4050 - CONFIG_SYS_GENERIC_BOARD
4051 This selects the architecture-generic board system instead of the
4052 architecture-specific board files. It is intended to move boards
4053 to this new framework over time. Defining this will disable the
4054 arch/foo/lib/board.c file and use common/board_f.c and
4055 common/board_r.c instead. To use this option your architecture
4056 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4057 its config.mk file). If you find problems enabling this option on
4058 your board please report the problem and send patches!
4060 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4061 This is set by OMAP boards for the max time that reset should
4062 be asserted. See doc/README.omap-reset-time for details on how
4063 the value can be calulated on a given board.
4066 If stdint.h is available with your toolchain you can define this
4067 option to enable it. You can provide option 'USE_STDINT=1' when
4068 building U-Boot to enable this.
4070 The following definitions that deal with the placement and management
4071 of environment data (variable area); in general, we support the
4072 following configurations:
4074 - CONFIG_BUILD_ENVCRC:
4076 Builds up envcrc with the target environment so that external utils
4077 may easily extract it and embed it in final U-Boot images.
4079 - CONFIG_ENV_IS_IN_FLASH:
4081 Define this if the environment is in flash memory.
4083 a) The environment occupies one whole flash sector, which is
4084 "embedded" in the text segment with the U-Boot code. This
4085 happens usually with "bottom boot sector" or "top boot
4086 sector" type flash chips, which have several smaller
4087 sectors at the start or the end. For instance, such a
4088 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4089 such a case you would place the environment in one of the
4090 4 kB sectors - with U-Boot code before and after it. With
4091 "top boot sector" type flash chips, you would put the
4092 environment in one of the last sectors, leaving a gap
4093 between U-Boot and the environment.
4095 - CONFIG_ENV_OFFSET:
4097 Offset of environment data (variable area) to the
4098 beginning of flash memory; for instance, with bottom boot
4099 type flash chips the second sector can be used: the offset
4100 for this sector is given here.
4102 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4106 This is just another way to specify the start address of
4107 the flash sector containing the environment (instead of
4110 - CONFIG_ENV_SECT_SIZE:
4112 Size of the sector containing the environment.
4115 b) Sometimes flash chips have few, equal sized, BIG sectors.
4116 In such a case you don't want to spend a whole sector for
4121 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4122 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4123 of this flash sector for the environment. This saves
4124 memory for the RAM copy of the environment.
4126 It may also save flash memory if you decide to use this
4127 when your environment is "embedded" within U-Boot code,
4128 since then the remainder of the flash sector could be used
4129 for U-Boot code. It should be pointed out that this is
4130 STRONGLY DISCOURAGED from a robustness point of view:
4131 updating the environment in flash makes it always
4132 necessary to erase the WHOLE sector. If something goes
4133 wrong before the contents has been restored from a copy in
4134 RAM, your target system will be dead.
4136 - CONFIG_ENV_ADDR_REDUND
4137 CONFIG_ENV_SIZE_REDUND
4139 These settings describe a second storage area used to hold
4140 a redundant copy of the environment data, so that there is
4141 a valid backup copy in case there is a power failure during
4142 a "saveenv" operation.
4144 BE CAREFUL! Any changes to the flash layout, and some changes to the
4145 source code will make it necessary to adapt <board>/u-boot.lds*
4149 - CONFIG_ENV_IS_IN_NVRAM:
4151 Define this if you have some non-volatile memory device
4152 (NVRAM, battery buffered SRAM) which you want to use for the
4158 These two #defines are used to determine the memory area you
4159 want to use for environment. It is assumed that this memory
4160 can just be read and written to, without any special
4163 BE CAREFUL! The first access to the environment happens quite early
4164 in U-Boot initalization (when we try to get the setting of for the
4165 console baudrate). You *MUST* have mapped your NVRAM area then, or
4168 Please note that even with NVRAM we still use a copy of the
4169 environment in RAM: we could work on NVRAM directly, but we want to
4170 keep settings there always unmodified except somebody uses "saveenv"
4171 to save the current settings.
4174 - CONFIG_ENV_IS_IN_EEPROM:
4176 Use this if you have an EEPROM or similar serial access
4177 device and a driver for it.
4179 - CONFIG_ENV_OFFSET:
4182 These two #defines specify the offset and size of the
4183 environment area within the total memory of your EEPROM.
4185 - CONFIG_SYS_I2C_EEPROM_ADDR:
4186 If defined, specified the chip address of the EEPROM device.
4187 The default address is zero.
4189 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4190 If defined, the number of bits used to address bytes in a
4191 single page in the EEPROM device. A 64 byte page, for example
4192 would require six bits.
4194 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4195 If defined, the number of milliseconds to delay between
4196 page writes. The default is zero milliseconds.
4198 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4199 The length in bytes of the EEPROM memory array address. Note
4200 that this is NOT the chip address length!
4202 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4203 EEPROM chips that implement "address overflow" are ones
4204 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4205 address and the extra bits end up in the "chip address" bit
4206 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4209 Note that we consider the length of the address field to
4210 still be one byte because the extra address bits are hidden
4211 in the chip address.
4213 - CONFIG_SYS_EEPROM_SIZE:
4214 The size in bytes of the EEPROM device.
4216 - CONFIG_ENV_EEPROM_IS_ON_I2C
4217 define this, if you have I2C and SPI activated, and your
4218 EEPROM, which holds the environment, is on the I2C bus.
4220 - CONFIG_I2C_ENV_EEPROM_BUS
4221 if you have an Environment on an EEPROM reached over
4222 I2C muxes, you can define here, how to reach this
4223 EEPROM. For example:
4225 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4227 EEPROM which holds the environment, is reached over
4228 a pca9547 i2c mux with address 0x70, channel 3.
4230 - CONFIG_ENV_IS_IN_DATAFLASH:
4232 Define this if you have a DataFlash memory device which you
4233 want to use for the environment.
4235 - CONFIG_ENV_OFFSET:
4239 These three #defines specify the offset and size of the
4240 environment area within the total memory of your DataFlash placed
4241 at the specified address.
4243 - CONFIG_ENV_IS_IN_SPI_FLASH:
4245 Define this if you have a SPI Flash memory device which you
4246 want to use for the environment.
4248 - CONFIG_ENV_OFFSET:
4251 These two #defines specify the offset and size of the
4252 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4253 aligned to an erase sector boundary.
4255 - CONFIG_ENV_SECT_SIZE:
4257 Define the SPI flash's sector size.
4259 - CONFIG_ENV_OFFSET_REDUND (optional):
4261 This setting describes a second storage area of CONFIG_ENV_SIZE
4262 size used to hold a redundant copy of the environment data, so
4263 that there is a valid backup copy in case there is a power failure
4264 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4265 aligned to an erase sector boundary.
4267 - CONFIG_ENV_SPI_BUS (optional):
4268 - CONFIG_ENV_SPI_CS (optional):
4270 Define the SPI bus and chip select. If not defined they will be 0.
4272 - CONFIG_ENV_SPI_MAX_HZ (optional):
4274 Define the SPI max work clock. If not defined then use 1MHz.
4276 - CONFIG_ENV_SPI_MODE (optional):
4278 Define the SPI work mode. If not defined then use SPI_MODE_3.
4280 - CONFIG_ENV_IS_IN_REMOTE:
4282 Define this if you have a remote memory space which you
4283 want to use for the local device's environment.
4288 These two #defines specify the address and size of the
4289 environment area within the remote memory space. The
4290 local device can get the environment from remote memory
4291 space by SRIO or PCIE links.
4293 BE CAREFUL! For some special cases, the local device can not use
4294 "saveenv" command. For example, the local device will get the
4295 environment stored in a remote NOR flash by SRIO or PCIE link,
4296 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4298 - CONFIG_ENV_IS_IN_NAND:
4300 Define this if you have a NAND device which you want to use
4301 for the environment.
4303 - CONFIG_ENV_OFFSET:
4306 These two #defines specify the offset and size of the environment
4307 area within the first NAND device. CONFIG_ENV_OFFSET must be
4308 aligned to an erase block boundary.
4310 - CONFIG_ENV_OFFSET_REDUND (optional):
4312 This setting describes a second storage area of CONFIG_ENV_SIZE
4313 size used to hold a redundant copy of the environment data, so
4314 that there is a valid backup copy in case there is a power failure
4315 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4316 aligned to an erase block boundary.
4318 - CONFIG_ENV_RANGE (optional):
4320 Specifies the length of the region in which the environment
4321 can be written. This should be a multiple of the NAND device's
4322 block size. Specifying a range with more erase blocks than
4323 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4324 the range to be avoided.
4326 - CONFIG_ENV_OFFSET_OOB (optional):
4328 Enables support for dynamically retrieving the offset of the
4329 environment from block zero's out-of-band data. The
4330 "nand env.oob" command can be used to record this offset.
4331 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4332 using CONFIG_ENV_OFFSET_OOB.
4334 - CONFIG_NAND_ENV_DST
4336 Defines address in RAM to which the nand_spl code should copy the
4337 environment. If redundant environment is used, it will be copied to
4338 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4340 - CONFIG_ENV_IS_IN_UBI:
4342 Define this if you have an UBI volume that you want to use for the
4343 environment. This has the benefit of wear-leveling the environment
4344 accesses, which is important on NAND.
4346 - CONFIG_ENV_UBI_PART:
4348 Define this to a string that is the mtd partition containing the UBI.
4350 - CONFIG_ENV_UBI_VOLUME:
4352 Define this to the name of the volume that you want to store the
4355 - CONFIG_ENV_UBI_VOLUME_REDUND:
4357 Define this to the name of another volume to store a second copy of
4358 the environment in. This will enable redundant environments in UBI.
4359 It is assumed that both volumes are in the same MTD partition.
4361 - CONFIG_UBI_SILENCE_MSG
4362 - CONFIG_UBIFS_SILENCE_MSG
4364 You will probably want to define these to avoid a really noisy system
4365 when storing the env in UBI.
4367 - CONFIG_ENV_IS_IN_FAT:
4368 Define this if you want to use the FAT file system for the environment.
4370 - FAT_ENV_INTERFACE:
4372 Define this to a string that is the name of the block device.
4374 - FAT_ENV_DEV_AND_PART:
4376 Define this to a string to specify the partition of the device. It can
4379 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4380 - "D:P": device D partition P. Error occurs if device D has no
4383 - "D" or "D:": device D partition 1 if device D has partition
4384 table, or the whole device D if has no partition
4386 - "D:auto": first partition in device D with bootable flag set.
4387 If none, first valid paratition in device D. If no
4388 partition table then means device D.
4392 It's a string of the FAT file name. This file use to store the
4396 This should be defined. Otherwise it cannot save the envrionment file.
4398 - CONFIG_ENV_IS_IN_MMC:
4400 Define this if you have an MMC device which you want to use for the
4403 - CONFIG_SYS_MMC_ENV_DEV:
4405 Specifies which MMC device the environment is stored in.
4407 - CONFIG_SYS_MMC_ENV_PART (optional):
4409 Specifies which MMC partition the environment is stored in. If not
4410 set, defaults to partition 0, the user area. Common values might be
4411 1 (first MMC boot partition), 2 (second MMC boot partition).
4413 - CONFIG_ENV_OFFSET:
4416 These two #defines specify the offset and size of the environment
4417 area within the specified MMC device.
4419 If offset is positive (the usual case), it is treated as relative to
4420 the start of the MMC partition. If offset is negative, it is treated
4421 as relative to the end of the MMC partition. This can be useful if
4422 your board may be fitted with different MMC devices, which have
4423 different sizes for the MMC partitions, and you always want the
4424 environment placed at the very end of the partition, to leave the
4425 maximum possible space before it, to store other data.
4427 These two values are in units of bytes, but must be aligned to an
4428 MMC sector boundary.
4430 - CONFIG_ENV_OFFSET_REDUND (optional):
4432 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4433 hold a redundant copy of the environment data. This provides a
4434 valid backup copy in case the other copy is corrupted, e.g. due
4435 to a power failure during a "saveenv" operation.
4437 This value may also be positive or negative; this is handled in the
4438 same way as CONFIG_ENV_OFFSET.
4440 This value is also in units of bytes, but must also be aligned to
4441 an MMC sector boundary.
4443 - CONFIG_ENV_SIZE_REDUND (optional):
4445 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4446 set. If this value is set, it must be set to the same value as
4449 - CONFIG_SYS_SPI_INIT_OFFSET
4451 Defines offset to the initial SPI buffer area in DPRAM. The
4452 area is used at an early stage (ROM part) if the environment
4453 is configured to reside in the SPI EEPROM: We need a 520 byte
4454 scratch DPRAM area. It is used between the two initialization
4455 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4456 to be a good choice since it makes it far enough from the
4457 start of the data area as well as from the stack pointer.
4459 Please note that the environment is read-only until the monitor
4460 has been relocated to RAM and a RAM copy of the environment has been
4461 created; also, when using EEPROM you will have to use getenv_f()
4462 until then to read environment variables.
4464 The environment is protected by a CRC32 checksum. Before the monitor
4465 is relocated into RAM, as a result of a bad CRC you will be working
4466 with the compiled-in default environment - *silently*!!! [This is
4467 necessary, because the first environment variable we need is the
4468 "baudrate" setting for the console - if we have a bad CRC, we don't
4469 have any device yet where we could complain.]
4471 Note: once the monitor has been relocated, then it will complain if
4472 the default environment is used; a new CRC is computed as soon as you
4473 use the "saveenv" command to store a valid environment.
4475 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4476 Echo the inverted Ethernet link state to the fault LED.
4478 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4479 also needs to be defined.
4481 - CONFIG_SYS_FAULT_MII_ADDR:
4482 MII address of the PHY to check for the Ethernet link state.
4484 - CONFIG_NS16550_MIN_FUNCTIONS:
4485 Define this if you desire to only have use of the NS16550_init
4486 and NS16550_putc functions for the serial driver located at
4487 drivers/serial/ns16550.c. This option is useful for saving
4488 space for already greatly restricted images, including but not
4489 limited to NAND_SPL configurations.
4491 - CONFIG_DISPLAY_BOARDINFO
4492 Display information about the board that U-Boot is running on
4493 when U-Boot starts up. The board function checkboard() is called
4496 - CONFIG_DISPLAY_BOARDINFO_LATE
4497 Similar to the previous option, but display this information
4498 later, once stdio is running and output goes to the LCD, if
4501 - CONFIG_BOARD_SIZE_LIMIT:
4502 Maximum size of the U-Boot image. When defined, the
4503 build system checks that the actual size does not
4506 Low Level (hardware related) configuration options:
4507 ---------------------------------------------------
4509 - CONFIG_SYS_CACHELINE_SIZE:
4510 Cache Line Size of the CPU.
4512 - CONFIG_SYS_DEFAULT_IMMR:
4513 Default address of the IMMR after system reset.
4515 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4516 and RPXsuper) to be able to adjust the position of
4517 the IMMR register after a reset.
4519 - CONFIG_SYS_CCSRBAR_DEFAULT:
4520 Default (power-on reset) physical address of CCSR on Freescale
4523 - CONFIG_SYS_CCSRBAR:
4524 Virtual address of CCSR. On a 32-bit build, this is typically
4525 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4527 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4528 for cross-platform code that uses that macro instead.
4530 - CONFIG_SYS_CCSRBAR_PHYS:
4531 Physical address of CCSR. CCSR can be relocated to a new
4532 physical address, if desired. In this case, this macro should
4533 be set to that address. Otherwise, it should be set to the
4534 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4535 is typically relocated on 36-bit builds. It is recommended
4536 that this macro be defined via the _HIGH and _LOW macros:
4538 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4539 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4541 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4542 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4543 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4544 used in assembly code, so it must not contain typecasts or
4545 integer size suffixes (e.g. "ULL").
4547 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4548 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4549 used in assembly code, so it must not contain typecasts or
4550 integer size suffixes (e.g. "ULL").
4552 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4553 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4554 forced to a value that ensures that CCSR is not relocated.
4556 - Floppy Disk Support:
4557 CONFIG_SYS_FDC_DRIVE_NUMBER
4559 the default drive number (default value 0)
4561 CONFIG_SYS_ISA_IO_STRIDE
4563 defines the spacing between FDC chipset registers
4566 CONFIG_SYS_ISA_IO_OFFSET
4568 defines the offset of register from address. It
4569 depends on which part of the data bus is connected to
4570 the FDC chipset. (default value 0)
4572 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4573 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4576 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4577 fdc_hw_init() is called at the beginning of the FDC
4578 setup. fdc_hw_init() must be provided by the board
4579 source code. It is used to make hardware dependant
4583 Most IDE controllers were designed to be connected with PCI
4584 interface. Only few of them were designed for AHB interface.
4585 When software is doing ATA command and data transfer to
4586 IDE devices through IDE-AHB controller, some additional
4587 registers accessing to these kind of IDE-AHB controller
4590 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4591 DO NOT CHANGE unless you know exactly what you're
4592 doing! (11-4) [MPC8xx/82xx systems only]
4594 - CONFIG_SYS_INIT_RAM_ADDR:
4596 Start address of memory area that can be used for
4597 initial data and stack; please note that this must be
4598 writable memory that is working WITHOUT special
4599 initialization, i. e. you CANNOT use normal RAM which
4600 will become available only after programming the
4601 memory controller and running certain initialization
4604 U-Boot uses the following memory types:
4605 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4606 - MPC824X: data cache
4607 - PPC4xx: data cache
4609 - CONFIG_SYS_GBL_DATA_OFFSET:
4611 Offset of the initial data structure in the memory
4612 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4613 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4614 data is located at the end of the available space
4615 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4616 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4617 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4618 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4621 On the MPC824X (or other systems that use the data
4622 cache for initial memory) the address chosen for
4623 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4624 point to an otherwise UNUSED address space between
4625 the top of RAM and the start of the PCI space.
4627 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4629 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4631 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4633 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4635 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4637 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4639 - CONFIG_SYS_OR_TIMING_SDRAM:
4642 - CONFIG_SYS_MAMR_PTA:
4643 periodic timer for refresh
4645 - CONFIG_SYS_DER: Debug Event Register (37-47)
4647 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4648 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4649 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4650 CONFIG_SYS_BR1_PRELIM:
4651 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4653 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4654 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4655 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4656 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4658 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4659 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4660 Machine Mode Register and Memory Periodic Timer
4661 Prescaler definitions (SDRAM timing)
4663 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4664 enable I2C microcode relocation patch (MPC8xx);
4665 define relocation offset in DPRAM [DSP2]
4667 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4668 enable SMC microcode relocation patch (MPC8xx);
4669 define relocation offset in DPRAM [SMC1]
4671 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4672 enable SPI microcode relocation patch (MPC8xx);
4673 define relocation offset in DPRAM [SCC4]
4675 - CONFIG_SYS_USE_OSCCLK:
4676 Use OSCM clock mode on MBX8xx board. Be careful,
4677 wrong setting might damage your board. Read
4678 doc/README.MBX before setting this variable!
4680 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4681 Offset of the bootmode word in DPRAM used by post
4682 (Power On Self Tests). This definition overrides
4683 #define'd default value in commproc.h resp.
4686 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4687 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4688 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4689 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4690 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4691 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4692 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4693 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4694 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4696 - CONFIG_PCI_DISABLE_PCIE:
4697 Disable PCI-Express on systems where it is supported but not
4700 - CONFIG_PCI_ENUM_ONLY
4701 Only scan through and get the devices on the busses.
4702 Don't do any setup work, presumably because someone or
4703 something has already done it, and we don't need to do it
4704 a second time. Useful for platforms that are pre-booted
4705 by coreboot or similar.
4707 - CONFIG_PCI_INDIRECT_BRIDGE:
4708 Enable support for indirect PCI bridges.
4711 Chip has SRIO or not
4714 Board has SRIO 1 port available
4717 Board has SRIO 2 port available
4719 - CONFIG_SRIO_PCIE_BOOT_MASTER
4720 Board can support master function for Boot from SRIO and PCIE
4722 - CONFIG_SYS_SRIOn_MEM_VIRT:
4723 Virtual Address of SRIO port 'n' memory region
4725 - CONFIG_SYS_SRIOn_MEM_PHYS:
4726 Physical Address of SRIO port 'n' memory region
4728 - CONFIG_SYS_SRIOn_MEM_SIZE:
4729 Size of SRIO port 'n' memory region
4731 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4732 Defined to tell the NAND controller that the NAND chip is using
4734 Not all NAND drivers use this symbol.
4735 Example of drivers that use it:
4736 - drivers/mtd/nand/ndfc.c
4737 - drivers/mtd/nand/mxc_nand.c
4739 - CONFIG_SYS_NDFC_EBC0_CFG
4740 Sets the EBC0_CFG register for the NDFC. If not defined
4741 a default value will be used.
4744 Get DDR timing information from an I2C EEPROM. Common
4745 with pluggable memory modules such as SODIMMs
4748 I2C address of the SPD EEPROM
4750 - CONFIG_SYS_SPD_BUS_NUM
4751 If SPD EEPROM is on an I2C bus other than the first
4752 one, specify here. Note that the value must resolve
4753 to something your driver can deal with.
4755 - CONFIG_SYS_DDR_RAW_TIMING
4756 Get DDR timing information from other than SPD. Common with
4757 soldered DDR chips onboard without SPD. DDR raw timing
4758 parameters are extracted from datasheet and hard-coded into
4759 header files or board specific files.
4761 - CONFIG_FSL_DDR_INTERACTIVE
4762 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4764 - CONFIG_SYS_83XX_DDR_USES_CS0
4765 Only for 83xx systems. If specified, then DDR should
4766 be configured using CS0 and CS1 instead of CS2 and CS3.
4768 - CONFIG_ETHER_ON_FEC[12]
4769 Define to enable FEC[12] on a 8xx series processor.
4771 - CONFIG_FEC[12]_PHY
4772 Define to the hardcoded PHY address which corresponds
4773 to the given FEC; i. e.
4774 #define CONFIG_FEC1_PHY 4
4775 means that the PHY with address 4 is connected to FEC1
4777 When set to -1, means to probe for first available.
4779 - CONFIG_FEC[12]_PHY_NORXERR
4780 The PHY does not have a RXERR line (RMII only).
4781 (so program the FEC to ignore it).
4784 Enable RMII mode for all FECs.
4785 Note that this is a global option, we can't
4786 have one FEC in standard MII mode and another in RMII mode.
4788 - CONFIG_CRC32_VERIFY
4789 Add a verify option to the crc32 command.
4792 => crc32 -v <address> <count> <crc32>
4794 Where address/count indicate a memory area
4795 and crc32 is the correct crc32 which the
4799 Add the "loopw" memory command. This only takes effect if
4800 the memory commands are activated globally (CONFIG_CMD_MEM).
4803 Add the "mdc" and "mwc" memory commands. These are cyclic
4808 This command will print 4 bytes (10,11,12,13) each 500 ms.
4810 => mwc.l 100 12345678 10
4811 This command will write 12345678 to address 100 all 10 ms.
4813 This only takes effect if the memory commands are activated
4814 globally (CONFIG_CMD_MEM).
4816 - CONFIG_SKIP_LOWLEVEL_INIT
4817 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4818 low level initializations (like setting up the memory
4819 controller) are omitted and/or U-Boot does not
4820 relocate itself into RAM.
4822 Normally this variable MUST NOT be defined. The only
4823 exception is when U-Boot is loaded (to RAM) by some
4824 other boot loader or by a debugger which performs
4825 these initializations itself.
4828 Modifies the behaviour of start.S when compiling a loader
4829 that is executed before the actual U-Boot. E.g. when
4830 compiling a NAND SPL.
4833 Modifies the behaviour of start.S when compiling a loader
4834 that is executed after the SPL and before the actual U-Boot.
4835 It is loaded by the SPL.
4837 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4838 Only for 85xx systems. If this variable is specified, the section
4839 .resetvec is not kept and the section .bootpg is placed in the
4840 previous 4k of the .text section.
4842 - CONFIG_ARCH_MAP_SYSMEM
4843 Generally U-Boot (and in particular the md command) uses
4844 effective address. It is therefore not necessary to regard
4845 U-Boot address as virtual addresses that need to be translated
4846 to physical addresses. However, sandbox requires this, since
4847 it maintains its own little RAM buffer which contains all
4848 addressable memory. This option causes some memory accesses
4849 to be mapped through map_sysmem() / unmap_sysmem().
4851 - CONFIG_USE_ARCH_MEMCPY
4852 CONFIG_USE_ARCH_MEMSET
4853 If these options are used a optimized version of memcpy/memset will
4854 be used if available. These functions may be faster under some
4855 conditions but may increase the binary size.
4857 - CONFIG_X86_RESET_VECTOR
4858 If defined, the x86 reset vector code is included. This is not
4859 needed when U-Boot is running from Coreboot.
4862 Defines the MPU clock speed (in MHz).
4864 NOTE : currently only supported on AM335x platforms.
4866 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4867 Enables the RTC32K OSC on AM33xx based plattforms
4869 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4870 Option to disable subpage write in NAND driver
4871 driver that uses this:
4872 drivers/mtd/nand/davinci_nand.c
4874 Freescale QE/FMAN Firmware Support:
4875 -----------------------------------
4877 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4878 loading of "firmware", which is encoded in the QE firmware binary format.
4879 This firmware often needs to be loaded during U-Boot booting, so macros
4880 are used to identify the storage device (NOR flash, SPI, etc) and the address
4883 - CONFIG_SYS_FMAN_FW_ADDR
4884 The address in the storage device where the FMAN microcode is located. The
4885 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4888 - CONFIG_SYS_QE_FW_ADDR
4889 The address in the storage device where the QE microcode is located. The
4890 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4893 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4894 The maximum possible size of the firmware. The firmware binary format
4895 has a field that specifies the actual size of the firmware, but it
4896 might not be possible to read any part of the firmware unless some
4897 local storage is allocated to hold the entire firmware first.
4899 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4900 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4901 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4902 virtual address in NOR flash.
4904 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4905 Specifies that QE/FMAN firmware is located in NAND flash.
4906 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4908 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4909 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4910 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4912 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4913 Specifies that QE/FMAN firmware is located on the primary SPI
4914 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4916 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4917 Specifies that QE/FMAN firmware is located in the remote (master)
4918 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4919 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4920 window->master inbound window->master LAW->the ucode address in
4921 master's memory space.
4923 Freescale Layerscape Management Complex Firmware Support:
4924 ---------------------------------------------------------
4925 The Freescale Layerscape Management Complex (MC) supports the loading of
4927 This firmware often needs to be loaded during U-Boot booting, so macros
4928 are used to identify the storage device (NOR flash, SPI, etc) and the address
4931 - CONFIG_FSL_MC_ENET
4932 Enable the MC driver for Layerscape SoCs.
4934 - CONFIG_SYS_LS_MC_FW_ADDR
4935 The address in the storage device where the firmware is located. The
4936 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4939 - CONFIG_SYS_LS_MC_FW_LENGTH
4940 The maximum possible size of the firmware. The firmware binary format
4941 has a field that specifies the actual size of the firmware, but it
4942 might not be possible to read any part of the firmware unless some
4943 local storage is allocated to hold the entire firmware first.
4945 - CONFIG_SYS_LS_MC_FW_IN_NOR
4946 Specifies that MC firmware is located in NOR flash, mapped as
4947 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4948 virtual address in NOR flash.
4950 Building the Software:
4951 ======================
4953 Building U-Boot has been tested in several native build environments
4954 and in many different cross environments. Of course we cannot support
4955 all possibly existing versions of cross development tools in all
4956 (potentially obsolete) versions. In case of tool chain problems we
4957 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4958 which is extensively used to build and test U-Boot.
4960 If you are not using a native environment, it is assumed that you
4961 have GNU cross compiling tools available in your path. In this case,
4962 you must set the environment variable CROSS_COMPILE in your shell.
4963 Note that no changes to the Makefile or any other source files are
4964 necessary. For example using the ELDK on a 4xx CPU, please enter:
4966 $ CROSS_COMPILE=ppc_4xx-
4967 $ export CROSS_COMPILE
4969 Note: If you wish to generate Windows versions of the utilities in
4970 the tools directory you can use the MinGW toolchain
4971 (http://www.mingw.org). Set your HOST tools to the MinGW
4972 toolchain and execute 'make tools'. For example:
4974 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4976 Binaries such as tools/mkimage.exe will be created which can
4977 be executed on computers running Windows.
4979 U-Boot is intended to be simple to build. After installing the
4980 sources you must configure U-Boot for one specific board type. This
4985 where "NAME_defconfig" is the name of one of the existing configu-
4986 rations; see boards.cfg for supported names.
4988 Note: for some board special configuration names may exist; check if
4989 additional information is available from the board vendor; for
4990 instance, the TQM823L systems are available without (standard)
4991 or with LCD support. You can select such additional "features"
4992 when choosing the configuration, i. e.
4994 make TQM823L_defconfig
4995 - will configure for a plain TQM823L, i. e. no LCD support
4997 make TQM823L_LCD_defconfig
4998 - will configure for a TQM823L with U-Boot console on LCD
5003 Finally, type "make all", and you should get some working U-Boot
5004 images ready for download to / installation on your system:
5006 - "u-boot.bin" is a raw binary image
5007 - "u-boot" is an image in ELF binary format
5008 - "u-boot.srec" is in Motorola S-Record format
5010 By default the build is performed locally and the objects are saved
5011 in the source directory. One of the two methods can be used to change
5012 this behavior and build U-Boot to some external directory:
5014 1. Add O= to the make command line invocations:
5016 make O=/tmp/build distclean
5017 make O=/tmp/build NAME_defconfig
5018 make O=/tmp/build all
5020 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5022 export KBUILD_OUTPUT=/tmp/build
5027 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5031 Please be aware that the Makefiles assume you are using GNU make, so
5032 for instance on NetBSD you might need to use "gmake" instead of
5036 If the system board that you have is not listed, then you will need
5037 to port U-Boot to your hardware platform. To do this, follow these
5040 1. Add a new configuration option for your board to the toplevel
5041 "boards.cfg" file, using the existing entries as examples.
5042 Follow the instructions there to keep the boards in order.
5043 2. Create a new directory to hold your board specific code. Add any
5044 files you need. In your board directory, you will need at least
5045 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5046 3. Create a new configuration file "include/configs/<board>.h" for
5048 3. If you're porting U-Boot to a new CPU, then also create a new
5049 directory to hold your CPU specific code. Add any files you need.
5050 4. Run "make <board>_defconfig" with your new name.
5051 5. Type "make", and you should get a working "u-boot.srec" file
5052 to be installed on your target system.
5053 6. Debug and solve any problems that might arise.
5054 [Of course, this last step is much harder than it sounds.]
5057 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5058 ==============================================================
5060 If you have modified U-Boot sources (for instance added a new board
5061 or support for new devices, a new CPU, etc.) you are expected to
5062 provide feedback to the other developers. The feedback normally takes
5063 the form of a "patch", i. e. a context diff against a certain (latest
5064 official or latest in the git repository) version of U-Boot sources.
5066 But before you submit such a patch, please verify that your modifi-
5067 cation did not break existing code. At least make sure that *ALL* of
5068 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5069 just run the "MAKEALL" script, which will configure and build U-Boot
5070 for ALL supported system. Be warned, this will take a while. You can
5071 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5072 environment variable to the script, i. e. to use the ELDK cross tools
5075 CROSS_COMPILE=ppc_8xx- MAKEALL
5077 or to build on a native PowerPC system you can type
5079 CROSS_COMPILE=' ' MAKEALL
5081 When using the MAKEALL script, the default behaviour is to build
5082 U-Boot in the source directory. This location can be changed by
5083 setting the BUILD_DIR environment variable. Also, for each target
5084 built, the MAKEALL script saves two log files (<target>.ERR and
5085 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5086 location can be changed by setting the MAKEALL_LOGDIR environment
5087 variable. For example:
5089 export BUILD_DIR=/tmp/build
5090 export MAKEALL_LOGDIR=/tmp/log
5091 CROSS_COMPILE=ppc_8xx- MAKEALL
5093 With the above settings build objects are saved in the /tmp/build,
5094 log files are saved in the /tmp/log and the source tree remains clean
5095 during the whole build process.
5098 See also "U-Boot Porting Guide" below.
5101 Monitor Commands - Overview:
5102 ============================
5104 go - start application at address 'addr'
5105 run - run commands in an environment variable
5106 bootm - boot application image from memory
5107 bootp - boot image via network using BootP/TFTP protocol
5108 bootz - boot zImage from memory
5109 tftpboot- boot image via network using TFTP protocol
5110 and env variables "ipaddr" and "serverip"
5111 (and eventually "gatewayip")
5112 tftpput - upload a file via network using TFTP protocol
5113 rarpboot- boot image via network using RARP/TFTP protocol
5114 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5115 loads - load S-Record file over serial line
5116 loadb - load binary file over serial line (kermit mode)
5118 mm - memory modify (auto-incrementing)
5119 nm - memory modify (constant address)
5120 mw - memory write (fill)
5122 cmp - memory compare
5123 crc32 - checksum calculation
5124 i2c - I2C sub-system
5125 sspi - SPI utility commands
5126 base - print or set address offset
5127 printenv- print environment variables
5128 setenv - set environment variables
5129 saveenv - save environment variables to persistent storage
5130 protect - enable or disable FLASH write protection
5131 erase - erase FLASH memory
5132 flinfo - print FLASH memory information
5133 nand - NAND memory operations (see doc/README.nand)
5134 bdinfo - print Board Info structure
5135 iminfo - print header information for application image
5136 coninfo - print console devices and informations
5137 ide - IDE sub-system
5138 loop - infinite loop on address range
5139 loopw - infinite write loop on address range
5140 mtest - simple RAM test
5141 icache - enable or disable instruction cache
5142 dcache - enable or disable data cache
5143 reset - Perform RESET of the CPU
5144 echo - echo args to console
5145 version - print monitor version
5146 help - print online help
5147 ? - alias for 'help'
5150 Monitor Commands - Detailed Description:
5151 ========================================
5155 For now: just type "help <command>".
5158 Environment Variables:
5159 ======================
5161 U-Boot supports user configuration using Environment Variables which
5162 can be made persistent by saving to Flash memory.
5164 Environment Variables are set using "setenv", printed using
5165 "printenv", and saved to Flash using "saveenv". Using "setenv"
5166 without a value can be used to delete a variable from the
5167 environment. As long as you don't save the environment you are
5168 working with an in-memory copy. In case the Flash area containing the
5169 environment is erased by accident, a default environment is provided.
5171 Some configuration options can be set using Environment Variables.
5173 List of environment variables (most likely not complete):
5175 baudrate - see CONFIG_BAUDRATE
5177 bootdelay - see CONFIG_BOOTDELAY
5179 bootcmd - see CONFIG_BOOTCOMMAND
5181 bootargs - Boot arguments when booting an RTOS image
5183 bootfile - Name of the image to load with TFTP
5185 bootm_low - Memory range available for image processing in the bootm
5186 command can be restricted. This variable is given as
5187 a hexadecimal number and defines lowest address allowed
5188 for use by the bootm command. See also "bootm_size"
5189 environment variable. Address defined by "bootm_low" is
5190 also the base of the initial memory mapping for the Linux
5191 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5194 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5195 This variable is given as a hexadecimal number and it
5196 defines the size of the memory region starting at base
5197 address bootm_low that is accessible by the Linux kernel
5198 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5199 as the default value if it is defined, and bootm_size is
5202 bootm_size - Memory range available for image processing in the bootm
5203 command can be restricted. This variable is given as
5204 a hexadecimal number and defines the size of the region
5205 allowed for use by the bootm command. See also "bootm_low"
5206 environment variable.
5208 updatefile - Location of the software update file on a TFTP server, used
5209 by the automatic software update feature. Please refer to
5210 documentation in doc/README.update for more details.
5212 autoload - if set to "no" (any string beginning with 'n'),
5213 "bootp" will just load perform a lookup of the
5214 configuration from the BOOTP server, but not try to
5215 load any image using TFTP
5217 autostart - if set to "yes", an image loaded using the "bootp",
5218 "rarpboot", "tftpboot" or "diskboot" commands will
5219 be automatically started (by internally calling
5222 If set to "no", a standalone image passed to the
5223 "bootm" command will be copied to the load address
5224 (and eventually uncompressed), but NOT be started.
5225 This can be used to load and uncompress arbitrary
5228 fdt_high - if set this restricts the maximum address that the
5229 flattened device tree will be copied into upon boot.
5230 For example, if you have a system with 1 GB memory
5231 at physical address 0x10000000, while Linux kernel
5232 only recognizes the first 704 MB as low memory, you
5233 may need to set fdt_high as 0x3C000000 to have the
5234 device tree blob be copied to the maximum address
5235 of the 704 MB low memory, so that Linux kernel can
5236 access it during the boot procedure.
5238 If this is set to the special value 0xFFFFFFFF then
5239 the fdt will not be copied at all on boot. For this
5240 to work it must reside in writable memory, have
5241 sufficient padding on the end of it for u-boot to
5242 add the information it needs into it, and the memory
5243 must be accessible by the kernel.
5245 fdtcontroladdr- if set this is the address of the control flattened
5246 device tree used by U-Boot when CONFIG_OF_CONTROL is
5249 i2cfast - (PPC405GP|PPC405EP only)
5250 if set to 'y' configures Linux I2C driver for fast
5251 mode (400kHZ). This environment variable is used in
5252 initialization code. So, for changes to be effective
5253 it must be saved and board must be reset.
5255 initrd_high - restrict positioning of initrd images:
5256 If this variable is not set, initrd images will be
5257 copied to the highest possible address in RAM; this
5258 is usually what you want since it allows for
5259 maximum initrd size. If for some reason you want to
5260 make sure that the initrd image is loaded below the
5261 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5262 variable to a value of "no" or "off" or "0".
5263 Alternatively, you can set it to a maximum upper
5264 address to use (U-Boot will still check that it
5265 does not overwrite the U-Boot stack and data).
5267 For instance, when you have a system with 16 MB
5268 RAM, and want to reserve 4 MB from use by Linux,
5269 you can do this by adding "mem=12M" to the value of
5270 the "bootargs" variable. However, now you must make
5271 sure that the initrd image is placed in the first
5272 12 MB as well - this can be done with
5274 setenv initrd_high 00c00000
5276 If you set initrd_high to 0xFFFFFFFF, this is an
5277 indication to U-Boot that all addresses are legal
5278 for the Linux kernel, including addresses in flash
5279 memory. In this case U-Boot will NOT COPY the
5280 ramdisk at all. This may be useful to reduce the
5281 boot time on your system, but requires that this
5282 feature is supported by your Linux kernel.
5284 ipaddr - IP address; needed for tftpboot command
5286 loadaddr - Default load address for commands like "bootp",
5287 "rarpboot", "tftpboot", "loadb" or "diskboot"
5289 loads_echo - see CONFIG_LOADS_ECHO
5291 serverip - TFTP server IP address; needed for tftpboot command
5293 bootretry - see CONFIG_BOOT_RETRY_TIME
5295 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5297 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5299 ethprime - controls which interface is used first.
5301 ethact - controls which interface is currently active.
5302 For example you can do the following
5304 => setenv ethact FEC
5305 => ping 192.168.0.1 # traffic sent on FEC
5306 => setenv ethact SCC
5307 => ping 10.0.0.1 # traffic sent on SCC
5309 ethrotate - When set to "no" U-Boot does not go through all
5310 available network interfaces.
5311 It just stays at the currently selected interface.
5313 netretry - When set to "no" each network operation will
5314 either succeed or fail without retrying.
5315 When set to "once" the network operation will
5316 fail when all the available network interfaces
5317 are tried once without success.
5318 Useful on scripts which control the retry operation
5321 npe_ucode - set load address for the NPE microcode
5323 silent_linux - If set then linux will be told to boot silently, by
5324 changing the console to be empty. If "yes" it will be
5325 made silent. If "no" it will not be made silent. If
5326 unset, then it will be made silent if the U-Boot console
5329 tftpsrcport - If this is set, the value is used for TFTP's
5332 tftpdstport - If this is set, the value is used for TFTP's UDP
5333 destination port instead of the Well Know Port 69.
5335 tftpblocksize - Block size to use for TFTP transfers; if not set,
5336 we use the TFTP server's default block size
5338 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5339 seconds, minimum value is 1000 = 1 second). Defines
5340 when a packet is considered to be lost so it has to
5341 be retransmitted. The default is 5000 = 5 seconds.
5342 Lowering this value may make downloads succeed
5343 faster in networks with high packet loss rates or
5344 with unreliable TFTP servers.
5346 vlan - When set to a value < 4095 the traffic over
5347 Ethernet is encapsulated/received over 802.1q
5350 The following image location variables contain the location of images
5351 used in booting. The "Image" column gives the role of the image and is
5352 not an environment variable name. The other columns are environment
5353 variable names. "File Name" gives the name of the file on a TFTP
5354 server, "RAM Address" gives the location in RAM the image will be
5355 loaded to, and "Flash Location" gives the image's address in NOR
5356 flash or offset in NAND flash.
5358 *Note* - these variables don't have to be defined for all boards, some
5359 boards currenlty use other variables for these purposes, and some
5360 boards use these variables for other purposes.
5362 Image File Name RAM Address Flash Location
5363 ----- --------- ----------- --------------
5364 u-boot u-boot u-boot_addr_r u-boot_addr
5365 Linux kernel bootfile kernel_addr_r kernel_addr
5366 device tree blob fdtfile fdt_addr_r fdt_addr
5367 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5369 The following environment variables may be used and automatically
5370 updated by the network boot commands ("bootp" and "rarpboot"),
5371 depending the information provided by your boot server:
5373 bootfile - see above
5374 dnsip - IP address of your Domain Name Server
5375 dnsip2 - IP address of your secondary Domain Name Server
5376 gatewayip - IP address of the Gateway (Router) to use
5377 hostname - Target hostname
5379 netmask - Subnet Mask
5380 rootpath - Pathname of the root filesystem on the NFS server
5381 serverip - see above
5384 There are two special Environment Variables:
5386 serial# - contains hardware identification information such
5387 as type string and/or serial number
5388 ethaddr - Ethernet address
5390 These variables can be set only once (usually during manufacturing of
5391 the board). U-Boot refuses to delete or overwrite these variables
5392 once they have been set once.
5395 Further special Environment Variables:
5397 ver - Contains the U-Boot version string as printed
5398 with the "version" command. This variable is
5399 readonly (see CONFIG_VERSION_VARIABLE).
5402 Please note that changes to some configuration parameters may take
5403 only effect after the next boot (yes, that's just like Windoze :-).
5406 Callback functions for environment variables:
5407 ---------------------------------------------
5409 For some environment variables, the behavior of u-boot needs to change
5410 when their values are changed. This functionailty allows functions to
5411 be associated with arbitrary variables. On creation, overwrite, or
5412 deletion, the callback will provide the opportunity for some side
5413 effect to happen or for the change to be rejected.
5415 The callbacks are named and associated with a function using the
5416 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5418 These callbacks are associated with variables in one of two ways. The
5419 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5420 in the board configuration to a string that defines a list of
5421 associations. The list must be in the following format:
5423 entry = variable_name[:callback_name]
5426 If the callback name is not specified, then the callback is deleted.
5427 Spaces are also allowed anywhere in the list.
5429 Callbacks can also be associated by defining the ".callbacks" variable
5430 with the same list format above. Any association in ".callbacks" will
5431 override any association in the static list. You can define
5432 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5433 ".callbacks" envirnoment variable in the default or embedded environment.
5436 Command Line Parsing:
5437 =====================
5439 There are two different command line parsers available with U-Boot:
5440 the old "simple" one, and the much more powerful "hush" shell:
5442 Old, simple command line parser:
5443 --------------------------------
5445 - supports environment variables (through setenv / saveenv commands)
5446 - several commands on one line, separated by ';'
5447 - variable substitution using "... ${name} ..." syntax
5448 - special characters ('$', ';') can be escaped by prefixing with '\',
5450 setenv bootcmd bootm \${address}
5451 - You can also escape text by enclosing in single apostrophes, for example:
5452 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5457 - similar to Bourne shell, with control structures like
5458 if...then...else...fi, for...do...done; while...do...done,
5459 until...do...done, ...
5460 - supports environment ("global") variables (through setenv / saveenv
5461 commands) and local shell variables (through standard shell syntax
5462 "name=value"); only environment variables can be used with "run"
5468 (1) If a command line (or an environment variable executed by a "run"
5469 command) contains several commands separated by semicolon, and
5470 one of these commands fails, then the remaining commands will be
5473 (2) If you execute several variables with one call to run (i. e.
5474 calling run with a list of variables as arguments), any failing
5475 command will cause "run" to terminate, i. e. the remaining
5476 variables are not executed.
5478 Note for Redundant Ethernet Interfaces:
5479 =======================================
5481 Some boards come with redundant Ethernet interfaces; U-Boot supports
5482 such configurations and is capable of automatic selection of a
5483 "working" interface when needed. MAC assignment works as follows:
5485 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5486 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5487 "eth1addr" (=>eth1), "eth2addr", ...
5489 If the network interface stores some valid MAC address (for instance
5490 in SROM), this is used as default address if there is NO correspon-
5491 ding setting in the environment; if the corresponding environment
5492 variable is set, this overrides the settings in the card; that means:
5494 o If the SROM has a valid MAC address, and there is no address in the
5495 environment, the SROM's address is used.
5497 o If there is no valid address in the SROM, and a definition in the
5498 environment exists, then the value from the environment variable is
5501 o If both the SROM and the environment contain a MAC address, and
5502 both addresses are the same, this MAC address is used.
5504 o If both the SROM and the environment contain a MAC address, and the
5505 addresses differ, the value from the environment is used and a
5508 o If neither SROM nor the environment contain a MAC address, an error
5511 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5512 will be programmed into hardware as part of the initialization process. This
5513 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5514 The naming convention is as follows:
5515 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5520 U-Boot is capable of booting (and performing other auxiliary operations on)
5521 images in two formats:
5523 New uImage format (FIT)
5524 -----------------------
5526 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5527 to Flattened Device Tree). It allows the use of images with multiple
5528 components (several kernels, ramdisks, etc.), with contents protected by
5529 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5535 Old image format is based on binary files which can be basically anything,
5536 preceded by a special header; see the definitions in include/image.h for
5537 details; basically, the header defines the following image properties:
5539 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5540 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5541 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5542 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5544 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5545 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5546 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5547 * Compression Type (uncompressed, gzip, bzip2)
5553 The header is marked by a special Magic Number, and both the header
5554 and the data portions of the image are secured against corruption by
5561 Although U-Boot should support any OS or standalone application
5562 easily, the main focus has always been on Linux during the design of
5565 U-Boot includes many features that so far have been part of some
5566 special "boot loader" code within the Linux kernel. Also, any
5567 "initrd" images to be used are no longer part of one big Linux image;
5568 instead, kernel and "initrd" are separate images. This implementation
5569 serves several purposes:
5571 - the same features can be used for other OS or standalone
5572 applications (for instance: using compressed images to reduce the
5573 Flash memory footprint)
5575 - it becomes much easier to port new Linux kernel versions because
5576 lots of low-level, hardware dependent stuff are done by U-Boot
5578 - the same Linux kernel image can now be used with different "initrd"
5579 images; of course this also means that different kernel images can
5580 be run with the same "initrd". This makes testing easier (you don't
5581 have to build a new "zImage.initrd" Linux image when you just
5582 change a file in your "initrd"). Also, a field-upgrade of the
5583 software is easier now.
5589 Porting Linux to U-Boot based systems:
5590 ---------------------------------------
5592 U-Boot cannot save you from doing all the necessary modifications to
5593 configure the Linux device drivers for use with your target hardware
5594 (no, we don't intend to provide a full virtual machine interface to
5597 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5599 Just make sure your machine specific header file (for instance
5600 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5601 Information structure as we define in include/asm-<arch>/u-boot.h,
5602 and make sure that your definition of IMAP_ADDR uses the same value
5603 as your U-Boot configuration in CONFIG_SYS_IMMR.
5605 Note that U-Boot now has a driver model, a unified model for drivers.
5606 If you are adding a new driver, plumb it into driver model. If there
5607 is no uclass available, you are encouraged to create one. See
5611 Configuring the Linux kernel:
5612 -----------------------------
5614 No specific requirements for U-Boot. Make sure you have some root
5615 device (initial ramdisk, NFS) for your target system.
5618 Building a Linux Image:
5619 -----------------------
5621 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5622 not used. If you use recent kernel source, a new build target
5623 "uImage" will exist which automatically builds an image usable by
5624 U-Boot. Most older kernels also have support for a "pImage" target,
5625 which was introduced for our predecessor project PPCBoot and uses a
5626 100% compatible format.
5630 make TQM850L_defconfig
5635 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5636 encapsulate a compressed Linux kernel image with header information,
5637 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5639 * build a standard "vmlinux" kernel image (in ELF binary format):
5641 * convert the kernel into a raw binary image:
5643 ${CROSS_COMPILE}-objcopy -O binary \
5644 -R .note -R .comment \
5645 -S vmlinux linux.bin
5647 * compress the binary image:
5651 * package compressed binary image for U-Boot:
5653 mkimage -A ppc -O linux -T kernel -C gzip \
5654 -a 0 -e 0 -n "Linux Kernel Image" \
5655 -d linux.bin.gz uImage
5658 The "mkimage" tool can also be used to create ramdisk images for use
5659 with U-Boot, either separated from the Linux kernel image, or
5660 combined into one file. "mkimage" encapsulates the images with a 64
5661 byte header containing information about target architecture,
5662 operating system, image type, compression method, entry points, time
5663 stamp, CRC32 checksums, etc.
5665 "mkimage" can be called in two ways: to verify existing images and
5666 print the header information, or to build new images.
5668 In the first form (with "-l" option) mkimage lists the information
5669 contained in the header of an existing U-Boot image; this includes
5670 checksum verification:
5672 tools/mkimage -l image
5673 -l ==> list image header information
5675 The second form (with "-d" option) is used to build a U-Boot image
5676 from a "data file" which is used as image payload:
5678 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5679 -n name -d data_file image
5680 -A ==> set architecture to 'arch'
5681 -O ==> set operating system to 'os'
5682 -T ==> set image type to 'type'
5683 -C ==> set compression type 'comp'
5684 -a ==> set load address to 'addr' (hex)
5685 -e ==> set entry point to 'ep' (hex)
5686 -n ==> set image name to 'name'
5687 -d ==> use image data from 'datafile'
5689 Right now, all Linux kernels for PowerPC systems use the same load
5690 address (0x00000000), but the entry point address depends on the
5693 - 2.2.x kernels have the entry point at 0x0000000C,
5694 - 2.3.x and later kernels have the entry point at 0x00000000.
5696 So a typical call to build a U-Boot image would read:
5698 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5699 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5700 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5701 > examples/uImage.TQM850L
5702 Image Name: 2.4.4 kernel for TQM850L
5703 Created: Wed Jul 19 02:34:59 2000
5704 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5705 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5706 Load Address: 0x00000000
5707 Entry Point: 0x00000000
5709 To verify the contents of the image (or check for corruption):
5711 -> tools/mkimage -l examples/uImage.TQM850L
5712 Image Name: 2.4.4 kernel for TQM850L
5713 Created: Wed Jul 19 02:34:59 2000
5714 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5715 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5716 Load Address: 0x00000000
5717 Entry Point: 0x00000000
5719 NOTE: for embedded systems where boot time is critical you can trade
5720 speed for memory and install an UNCOMPRESSED image instead: this
5721 needs more space in Flash, but boots much faster since it does not
5722 need to be uncompressed:
5724 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5725 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5726 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5727 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5728 > examples/uImage.TQM850L-uncompressed
5729 Image Name: 2.4.4 kernel for TQM850L
5730 Created: Wed Jul 19 02:34:59 2000
5731 Image Type: PowerPC Linux Kernel Image (uncompressed)
5732 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5733 Load Address: 0x00000000
5734 Entry Point: 0x00000000
5737 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5738 when your kernel is intended to use an initial ramdisk:
5740 -> tools/mkimage -n 'Simple Ramdisk Image' \
5741 > -A ppc -O linux -T ramdisk -C gzip \
5742 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5743 Image Name: Simple Ramdisk Image
5744 Created: Wed Jan 12 14:01:50 2000
5745 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5746 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5747 Load Address: 0x00000000
5748 Entry Point: 0x00000000
5750 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5751 option performs the converse operation of the mkimage's second form (the "-d"
5752 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5755 tools/dumpimage -i image -p position data_file
5756 -i ==> extract from the 'image' a specific 'data_file', \
5757 indexed by 'position'
5760 Installing a Linux Image:
5761 -------------------------
5763 To downloading a U-Boot image over the serial (console) interface,
5764 you must convert the image to S-Record format:
5766 objcopy -I binary -O srec examples/image examples/image.srec
5768 The 'objcopy' does not understand the information in the U-Boot
5769 image header, so the resulting S-Record file will be relative to
5770 address 0x00000000. To load it to a given address, you need to
5771 specify the target address as 'offset' parameter with the 'loads'
5774 Example: install the image to address 0x40100000 (which on the
5775 TQM8xxL is in the first Flash bank):
5777 => erase 40100000 401FFFFF
5783 ## Ready for S-Record download ...
5784 ~>examples/image.srec
5785 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5787 15989 15990 15991 15992
5788 [file transfer complete]
5790 ## Start Addr = 0x00000000
5793 You can check the success of the download using the 'iminfo' command;
5794 this includes a checksum verification so you can be sure no data
5795 corruption happened:
5799 ## Checking Image at 40100000 ...
5800 Image Name: 2.2.13 for initrd on TQM850L
5801 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5802 Data Size: 335725 Bytes = 327 kB = 0 MB
5803 Load Address: 00000000
5804 Entry Point: 0000000c
5805 Verifying Checksum ... OK
5811 The "bootm" command is used to boot an application that is stored in
5812 memory (RAM or Flash). In case of a Linux kernel image, the contents
5813 of the "bootargs" environment variable is passed to the kernel as
5814 parameters. You can check and modify this variable using the
5815 "printenv" and "setenv" commands:
5818 => printenv bootargs
5819 bootargs=root=/dev/ram
5821 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5823 => printenv bootargs
5824 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5827 ## Booting Linux kernel at 40020000 ...
5828 Image Name: 2.2.13 for NFS on TQM850L
5829 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5830 Data Size: 381681 Bytes = 372 kB = 0 MB
5831 Load Address: 00000000
5832 Entry Point: 0000000c
5833 Verifying Checksum ... OK
5834 Uncompressing Kernel Image ... OK
5835 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5836 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5837 time_init: decrementer frequency = 187500000/60
5838 Calibrating delay loop... 49.77 BogoMIPS
5839 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5842 If you want to boot a Linux kernel with initial RAM disk, you pass
5843 the memory addresses of both the kernel and the initrd image (PPBCOOT
5844 format!) to the "bootm" command:
5846 => imi 40100000 40200000
5848 ## Checking Image at 40100000 ...
5849 Image Name: 2.2.13 for initrd on TQM850L
5850 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5851 Data Size: 335725 Bytes = 327 kB = 0 MB
5852 Load Address: 00000000
5853 Entry Point: 0000000c
5854 Verifying Checksum ... OK
5856 ## Checking Image at 40200000 ...
5857 Image Name: Simple Ramdisk Image
5858 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5859 Data Size: 566530 Bytes = 553 kB = 0 MB
5860 Load Address: 00000000
5861 Entry Point: 00000000
5862 Verifying Checksum ... OK
5864 => bootm 40100000 40200000
5865 ## Booting Linux kernel at 40100000 ...
5866 Image Name: 2.2.13 for initrd on TQM850L
5867 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5868 Data Size: 335725 Bytes = 327 kB = 0 MB
5869 Load Address: 00000000
5870 Entry Point: 0000000c
5871 Verifying Checksum ... OK
5872 Uncompressing Kernel Image ... OK
5873 ## Loading RAMDisk Image at 40200000 ...
5874 Image Name: Simple Ramdisk Image
5875 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5876 Data Size: 566530 Bytes = 553 kB = 0 MB
5877 Load Address: 00000000
5878 Entry Point: 00000000
5879 Verifying Checksum ... OK
5880 Loading Ramdisk ... OK
5881 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5882 Boot arguments: root=/dev/ram
5883 time_init: decrementer frequency = 187500000/60
5884 Calibrating delay loop... 49.77 BogoMIPS
5886 RAMDISK: Compressed image found at block 0
5887 VFS: Mounted root (ext2 filesystem).
5891 Boot Linux and pass a flat device tree:
5894 First, U-Boot must be compiled with the appropriate defines. See the section
5895 titled "Linux Kernel Interface" above for a more in depth explanation. The
5896 following is an example of how to start a kernel and pass an updated
5902 oft=oftrees/mpc8540ads.dtb
5903 => tftp $oftaddr $oft
5904 Speed: 1000, full duplex
5906 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5907 Filename 'oftrees/mpc8540ads.dtb'.
5908 Load address: 0x300000
5911 Bytes transferred = 4106 (100a hex)
5912 => tftp $loadaddr $bootfile
5913 Speed: 1000, full duplex
5915 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5917 Load address: 0x200000
5918 Loading:############
5920 Bytes transferred = 1029407 (fb51f hex)
5925 => bootm $loadaddr - $oftaddr
5926 ## Booting image at 00200000 ...
5927 Image Name: Linux-2.6.17-dirty
5928 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5929 Data Size: 1029343 Bytes = 1005.2 kB
5930 Load Address: 00000000
5931 Entry Point: 00000000
5932 Verifying Checksum ... OK
5933 Uncompressing Kernel Image ... OK
5934 Booting using flat device tree at 0x300000
5935 Using MPC85xx ADS machine description
5936 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5940 More About U-Boot Image Types:
5941 ------------------------------
5943 U-Boot supports the following image types:
5945 "Standalone Programs" are directly runnable in the environment
5946 provided by U-Boot; it is expected that (if they behave
5947 well) you can continue to work in U-Boot after return from
5948 the Standalone Program.
5949 "OS Kernel Images" are usually images of some Embedded OS which
5950 will take over control completely. Usually these programs
5951 will install their own set of exception handlers, device
5952 drivers, set up the MMU, etc. - this means, that you cannot
5953 expect to re-enter U-Boot except by resetting the CPU.
5954 "RAMDisk Images" are more or less just data blocks, and their
5955 parameters (address, size) are passed to an OS kernel that is
5957 "Multi-File Images" contain several images, typically an OS
5958 (Linux) kernel image and one or more data images like
5959 RAMDisks. This construct is useful for instance when you want
5960 to boot over the network using BOOTP etc., where the boot
5961 server provides just a single image file, but you want to get
5962 for instance an OS kernel and a RAMDisk image.
5964 "Multi-File Images" start with a list of image sizes, each
5965 image size (in bytes) specified by an "uint32_t" in network
5966 byte order. This list is terminated by an "(uint32_t)0".
5967 Immediately after the terminating 0 follow the images, one by
5968 one, all aligned on "uint32_t" boundaries (size rounded up to
5969 a multiple of 4 bytes).
5971 "Firmware Images" are binary images containing firmware (like
5972 U-Boot or FPGA images) which usually will be programmed to
5975 "Script files" are command sequences that will be executed by
5976 U-Boot's command interpreter; this feature is especially
5977 useful when you configure U-Boot to use a real shell (hush)
5978 as command interpreter.
5980 Booting the Linux zImage:
5981 -------------------------
5983 On some platforms, it's possible to boot Linux zImage. This is done
5984 using the "bootz" command. The syntax of "bootz" command is the same
5985 as the syntax of "bootm" command.
5987 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5988 kernel with raw initrd images. The syntax is slightly different, the
5989 address of the initrd must be augmented by it's size, in the following
5990 format: "<initrd addres>:<initrd size>".
5996 One of the features of U-Boot is that you can dynamically load and
5997 run "standalone" applications, which can use some resources of
5998 U-Boot like console I/O functions or interrupt services.
6000 Two simple examples are included with the sources:
6005 'examples/hello_world.c' contains a small "Hello World" Demo
6006 application; it is automatically compiled when you build U-Boot.
6007 It's configured to run at address 0x00040004, so you can play with it
6011 ## Ready for S-Record download ...
6012 ~>examples/hello_world.srec
6013 1 2 3 4 5 6 7 8 9 10 11 ...
6014 [file transfer complete]
6016 ## Start Addr = 0x00040004
6018 => go 40004 Hello World! This is a test.
6019 ## Starting application at 0x00040004 ...
6030 Hit any key to exit ...
6032 ## Application terminated, rc = 0x0
6034 Another example, which demonstrates how to register a CPM interrupt
6035 handler with the U-Boot code, can be found in 'examples/timer.c'.
6036 Here, a CPM timer is set up to generate an interrupt every second.
6037 The interrupt service routine is trivial, just printing a '.'
6038 character, but this is just a demo program. The application can be
6039 controlled by the following keys:
6041 ? - print current values og the CPM Timer registers
6042 b - enable interrupts and start timer
6043 e - stop timer and disable interrupts
6044 q - quit application
6047 ## Ready for S-Record download ...
6048 ~>examples/timer.srec
6049 1 2 3 4 5 6 7 8 9 10 11 ...
6050 [file transfer complete]
6052 ## Start Addr = 0x00040004
6055 ## Starting application at 0x00040004 ...
6058 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6061 [q, b, e, ?] Set interval 1000000 us
6064 [q, b, e, ?] ........
6065 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6068 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6071 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6074 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6076 [q, b, e, ?] ...Stopping timer
6078 [q, b, e, ?] ## Application terminated, rc = 0x0
6084 Over time, many people have reported problems when trying to use the
6085 "minicom" terminal emulation program for serial download. I (wd)
6086 consider minicom to be broken, and recommend not to use it. Under
6087 Unix, I recommend to use C-Kermit for general purpose use (and
6088 especially for kermit binary protocol download ("loadb" command), and
6089 use "cu" for S-Record download ("loads" command). See
6090 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6091 for help with kermit.
6094 Nevertheless, if you absolutely want to use it try adding this
6095 configuration to your "File transfer protocols" section:
6097 Name Program Name U/D FullScr IO-Red. Multi
6098 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6099 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6105 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6106 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6108 Building requires a cross environment; it is known to work on
6109 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6110 need gmake since the Makefiles are not compatible with BSD make).
6111 Note that the cross-powerpc package does not install include files;
6112 attempting to build U-Boot will fail because <machine/ansi.h> is
6113 missing. This file has to be installed and patched manually:
6115 # cd /usr/pkg/cross/powerpc-netbsd/include
6117 # ln -s powerpc machine
6118 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6119 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6121 Native builds *don't* work due to incompatibilities between native
6122 and U-Boot include files.
6124 Booting assumes that (the first part of) the image booted is a
6125 stage-2 loader which in turn loads and then invokes the kernel
6126 proper. Loader sources will eventually appear in the NetBSD source
6127 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6128 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6131 Implementation Internals:
6132 =========================
6134 The following is not intended to be a complete description of every
6135 implementation detail. However, it should help to understand the
6136 inner workings of U-Boot and make it easier to port it to custom
6140 Initial Stack, Global Data:
6141 ---------------------------
6143 The implementation of U-Boot is complicated by the fact that U-Boot
6144 starts running out of ROM (flash memory), usually without access to
6145 system RAM (because the memory controller is not initialized yet).
6146 This means that we don't have writable Data or BSS segments, and BSS
6147 is not initialized as zero. To be able to get a C environment working
6148 at all, we have to allocate at least a minimal stack. Implementation
6149 options for this are defined and restricted by the CPU used: Some CPU
6150 models provide on-chip memory (like the IMMR area on MPC8xx and
6151 MPC826x processors), on others (parts of) the data cache can be
6152 locked as (mis-) used as memory, etc.
6154 Chris Hallinan posted a good summary of these issues to the
6155 U-Boot mailing list:
6157 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6158 From: "Chris Hallinan" <clh@net1plus.com>
6159 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6162 Correct me if I'm wrong, folks, but the way I understand it
6163 is this: Using DCACHE as initial RAM for Stack, etc, does not
6164 require any physical RAM backing up the cache. The cleverness
6165 is that the cache is being used as a temporary supply of
6166 necessary storage before the SDRAM controller is setup. It's
6167 beyond the scope of this list to explain the details, but you
6168 can see how this works by studying the cache architecture and
6169 operation in the architecture and processor-specific manuals.
6171 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6172 is another option for the system designer to use as an
6173 initial stack/RAM area prior to SDRAM being available. Either
6174 option should work for you. Using CS 4 should be fine if your
6175 board designers haven't used it for something that would
6176 cause you grief during the initial boot! It is frequently not
6179 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6180 with your processor/board/system design. The default value
6181 you will find in any recent u-boot distribution in
6182 walnut.h should work for you. I'd set it to a value larger
6183 than your SDRAM module. If you have a 64MB SDRAM module, set
6184 it above 400_0000. Just make sure your board has no resources
6185 that are supposed to respond to that address! That code in
6186 start.S has been around a while and should work as is when
6187 you get the config right.
6192 It is essential to remember this, since it has some impact on the C
6193 code for the initialization procedures:
6195 * Initialized global data (data segment) is read-only. Do not attempt
6198 * Do not use any uninitialized global data (or implicitely initialized
6199 as zero data - BSS segment) at all - this is undefined, initiali-
6200 zation is performed later (when relocating to RAM).
6202 * Stack space is very limited. Avoid big data buffers or things like
6205 Having only the stack as writable memory limits means we cannot use
6206 normal global data to share information beween the code. But it
6207 turned out that the implementation of U-Boot can be greatly
6208 simplified by making a global data structure (gd_t) available to all
6209 functions. We could pass a pointer to this data as argument to _all_
6210 functions, but this would bloat the code. Instead we use a feature of
6211 the GCC compiler (Global Register Variables) to share the data: we
6212 place a pointer (gd) to the global data into a register which we
6213 reserve for this purpose.
6215 When choosing a register for such a purpose we are restricted by the
6216 relevant (E)ABI specifications for the current architecture, and by
6217 GCC's implementation.
6219 For PowerPC, the following registers have specific use:
6221 R2: reserved for system use
6222 R3-R4: parameter passing and return values
6223 R5-R10: parameter passing
6224 R13: small data area pointer
6228 (U-Boot also uses R12 as internal GOT pointer. r12
6229 is a volatile register so r12 needs to be reset when
6230 going back and forth between asm and C)
6232 ==> U-Boot will use R2 to hold a pointer to the global data
6234 Note: on PPC, we could use a static initializer (since the
6235 address of the global data structure is known at compile time),
6236 but it turned out that reserving a register results in somewhat
6237 smaller code - although the code savings are not that big (on
6238 average for all boards 752 bytes for the whole U-Boot image,
6239 624 text + 127 data).
6241 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6242 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6244 ==> U-Boot will use P3 to hold a pointer to the global data
6246 On ARM, the following registers are used:
6248 R0: function argument word/integer result
6249 R1-R3: function argument word
6250 R9: platform specific
6251 R10: stack limit (used only if stack checking is enabled)
6252 R11: argument (frame) pointer
6253 R12: temporary workspace
6256 R15: program counter
6258 ==> U-Boot will use R9 to hold a pointer to the global data
6260 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6262 On Nios II, the ABI is documented here:
6263 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6265 ==> U-Boot will use gp to hold a pointer to the global data
6267 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6268 to access small data sections, so gp is free.
6270 On NDS32, the following registers are used:
6272 R0-R1: argument/return
6274 R15: temporary register for assembler
6275 R16: trampoline register
6276 R28: frame pointer (FP)
6277 R29: global pointer (GP)
6278 R30: link register (LP)
6279 R31: stack pointer (SP)
6280 PC: program counter (PC)
6282 ==> U-Boot will use R10 to hold a pointer to the global data
6284 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6285 or current versions of GCC may "optimize" the code too much.
6290 U-Boot runs in system state and uses physical addresses, i.e. the
6291 MMU is not used either for address mapping nor for memory protection.
6293 The available memory is mapped to fixed addresses using the memory
6294 controller. In this process, a contiguous block is formed for each
6295 memory type (Flash, SDRAM, SRAM), even when it consists of several
6296 physical memory banks.
6298 U-Boot is installed in the first 128 kB of the first Flash bank (on
6299 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6300 booting and sizing and initializing DRAM, the code relocates itself
6301 to the upper end of DRAM. Immediately below the U-Boot code some
6302 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6303 configuration setting]. Below that, a structure with global Board
6304 Info data is placed, followed by the stack (growing downward).
6306 Additionally, some exception handler code is copied to the low 8 kB
6307 of DRAM (0x00000000 ... 0x00001FFF).
6309 So a typical memory configuration with 16 MB of DRAM could look like
6312 0x0000 0000 Exception Vector code
6315 0x0000 2000 Free for Application Use
6321 0x00FB FF20 Monitor Stack (Growing downward)
6322 0x00FB FFAC Board Info Data and permanent copy of global data
6323 0x00FC 0000 Malloc Arena
6326 0x00FE 0000 RAM Copy of Monitor Code
6327 ... eventually: LCD or video framebuffer
6328 ... eventually: pRAM (Protected RAM - unchanged by reset)
6329 0x00FF FFFF [End of RAM]
6332 System Initialization:
6333 ----------------------
6335 In the reset configuration, U-Boot starts at the reset entry point
6336 (on most PowerPC systems at address 0x00000100). Because of the reset
6337 configuration for CS0# this is a mirror of the onboard Flash memory.
6338 To be able to re-map memory U-Boot then jumps to its link address.
6339 To be able to implement the initialization code in C, a (small!)
6340 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6341 which provide such a feature like MPC8xx or MPC8260), or in a locked
6342 part of the data cache. After that, U-Boot initializes the CPU core,
6343 the caches and the SIU.
6345 Next, all (potentially) available memory banks are mapped using a
6346 preliminary mapping. For example, we put them on 512 MB boundaries
6347 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6348 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6349 programmed for SDRAM access. Using the temporary configuration, a
6350 simple memory test is run that determines the size of the SDRAM
6353 When there is more than one SDRAM bank, and the banks are of
6354 different size, the largest is mapped first. For equal size, the first
6355 bank (CS2#) is mapped first. The first mapping is always for address
6356 0x00000000, with any additional banks following immediately to create
6357 contiguous memory starting from 0.
6359 Then, the monitor installs itself at the upper end of the SDRAM area
6360 and allocates memory for use by malloc() and for the global Board
6361 Info data; also, the exception vector code is copied to the low RAM
6362 pages, and the final stack is set up.
6364 Only after this relocation will you have a "normal" C environment;
6365 until that you are restricted in several ways, mostly because you are
6366 running from ROM, and because the code will have to be relocated to a
6370 U-Boot Porting Guide:
6371 ----------------------
6373 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6377 int main(int argc, char *argv[])
6379 sighandler_t no_more_time;
6381 signal(SIGALRM, no_more_time);
6382 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6384 if (available_money > available_manpower) {
6385 Pay consultant to port U-Boot;
6389 Download latest U-Boot source;
6391 Subscribe to u-boot mailing list;
6394 email("Hi, I am new to U-Boot, how do I get started?");
6397 Read the README file in the top level directory;
6398 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6399 Read applicable doc/*.README;
6400 Read the source, Luke;
6401 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6404 if (available_money > toLocalCurrency ($2500))
6407 Add a lot of aggravation and time;
6409 if (a similar board exists) { /* hopefully... */
6410 cp -a board/<similar> board/<myboard>
6411 cp include/configs/<similar>.h include/configs/<myboard>.h
6413 Create your own board support subdirectory;
6414 Create your own board include/configs/<myboard>.h file;
6416 Edit new board/<myboard> files
6417 Edit new include/configs/<myboard>.h
6422 Add / modify source code;
6426 email("Hi, I am having problems...");
6428 Send patch file to the U-Boot email list;
6429 if (reasonable critiques)
6430 Incorporate improvements from email list code review;
6432 Defend code as written;
6438 void no_more_time (int sig)
6447 All contributions to U-Boot should conform to the Linux kernel
6448 coding style; see the file "Documentation/CodingStyle" and the script
6449 "scripts/Lindent" in your Linux kernel source directory.
6451 Source files originating from a different project (for example the
6452 MTD subsystem) are generally exempt from these guidelines and are not
6453 reformated to ease subsequent migration to newer versions of those
6456 Please note that U-Boot is implemented in C (and to some small parts in
6457 Assembler); no C++ is used, so please do not use C++ style comments (//)
6460 Please also stick to the following formatting rules:
6461 - remove any trailing white space
6462 - use TAB characters for indentation and vertical alignment, not spaces
6463 - make sure NOT to use DOS '\r\n' line feeds
6464 - do not add more than 2 consecutive empty lines to source files
6465 - do not add trailing empty lines to source files
6467 Submissions which do not conform to the standards may be returned
6468 with a request to reformat the changes.
6474 Since the number of patches for U-Boot is growing, we need to
6475 establish some rules. Submissions which do not conform to these rules
6476 may be rejected, even when they contain important and valuable stuff.
6478 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6480 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6481 see http://lists.denx.de/mailman/listinfo/u-boot
6483 When you send a patch, please include the following information with
6486 * For bug fixes: a description of the bug and how your patch fixes
6487 this bug. Please try to include a way of demonstrating that the
6488 patch actually fixes something.
6490 * For new features: a description of the feature and your
6493 * A CHANGELOG entry as plaintext (separate from the patch)
6495 * For major contributions, your entry to the CREDITS file
6497 * When you add support for a new board, don't forget to add a
6498 maintainer e-mail address to the boards.cfg file, too.
6500 * If your patch adds new configuration options, don't forget to
6501 document these in the README file.
6503 * The patch itself. If you are using git (which is *strongly*
6504 recommended) you can easily generate the patch using the
6505 "git format-patch". If you then use "git send-email" to send it to
6506 the U-Boot mailing list, you will avoid most of the common problems
6507 with some other mail clients.
6509 If you cannot use git, use "diff -purN OLD NEW". If your version of
6510 diff does not support these options, then get the latest version of
6513 The current directory when running this command shall be the parent
6514 directory of the U-Boot source tree (i. e. please make sure that
6515 your patch includes sufficient directory information for the
6518 We prefer patches as plain text. MIME attachments are discouraged,
6519 and compressed attachments must not be used.
6521 * If one logical set of modifications affects or creates several
6522 files, all these changes shall be submitted in a SINGLE patch file.
6524 * Changesets that contain different, unrelated modifications shall be
6525 submitted as SEPARATE patches, one patch per changeset.
6530 * Before sending the patch, run the MAKEALL script on your patched
6531 source tree and make sure that no errors or warnings are reported
6532 for any of the boards.
6534 * Keep your modifications to the necessary minimum: A patch
6535 containing several unrelated changes or arbitrary reformats will be
6536 returned with a request to re-formatting / split it.
6538 * If you modify existing code, make sure that your new code does not
6539 add to the memory footprint of the code ;-) Small is beautiful!
6540 When adding new features, these should compile conditionally only
6541 (using #ifdef), and the resulting code with the new feature
6542 disabled must not need more memory than the old code without your
6545 * Remember that there is a size limit of 100 kB per message on the
6546 u-boot mailing list. Bigger patches will be moderated. If they are
6547 reasonable and not too big, they will be acknowledged. But patches
6548 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob