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 file to find out who contributed
38 the specific port. In addition, there are various MAINTAINERS files
39 scattered throughout the U-Boot source identifying the people or
40 companies responsible for various boards and subsystems.
42 Note: As of August, 2010, there is no longer a CHANGELOG file in the
43 actual U-Boot source tree; however, it can be created dynamically
44 from the Git log using:
52 In case you have questions about, problems with or contributions for
53 U-Boot, you should send a message to the U-Boot mailing list at
54 <u-boot@lists.denx.de>. There is also an archive of previous traffic
55 on the mailing list - please search the archive before asking FAQ's.
56 Please see http://lists.denx.de/pipermail/u-boot and
57 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
60 Where to get source code:
61 =========================
63 The U-Boot source code is maintained in the Git repository at
64 git://www.denx.de/git/u-boot.git ; you can browse it online at
65 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
67 The "snapshot" links on this page allow you to download tarballs of
68 any version you might be interested in. Official releases are also
69 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
72 Pre-built (and tested) images are available from
73 ftp://ftp.denx.de/pub/u-boot/images/
79 - start from 8xxrom sources
80 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
82 - make it easier to add custom boards
83 - make it possible to add other [PowerPC] CPUs
84 - extend functions, especially:
85 * Provide extended interface to Linux boot loader
88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
89 - create ARMBoot project (http://sourceforge.net/projects/armboot)
90 - add other CPU families (starting with ARM)
91 - create U-Boot project (http://sourceforge.net/projects/u-boot)
92 - current project page: see http://www.denx.de/wiki/U-Boot
98 The "official" name of this project is "Das U-Boot". The spelling
99 "U-Boot" shall be used in all written text (documentation, comments
100 in source files etc.). Example:
102 This is the README file for the U-Boot project.
104 File names etc. shall be based on the string "u-boot". Examples:
106 include/asm-ppc/u-boot.h
108 #include <asm/u-boot.h>
110 Variable names, preprocessor constants etc. shall be either based on
111 the string "u_boot" or on "U_BOOT". Example:
113 U_BOOT_VERSION u_boot_logo
114 IH_OS_U_BOOT u_boot_hush_start
120 Starting with the release in October 2008, the names of the releases
121 were changed from numerical release numbers without deeper meaning
122 into a time stamp based numbering. Regular releases are identified by
123 names consisting of the calendar year and month of the release date.
124 Additional fields (if present) indicate release candidates or bug fix
125 releases in "stable" maintenance trees.
128 U-Boot v2009.11 - Release November 2009
129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
130 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
136 /arch Architecture specific files
137 /arc Files generic to ARC architecture
138 /arm Files generic to ARM architecture
139 /avr32 Files generic to AVR32 architecture
140 /blackfin Files generic to Analog Devices Blackfin architecture
141 /m68k Files generic to m68k architecture
142 /microblaze Files generic to microblaze architecture
143 /mips Files generic to MIPS architecture
144 /nds32 Files generic to NDS32 architecture
145 /nios2 Files generic to Altera NIOS2 architecture
146 /openrisc Files generic to OpenRISC architecture
147 /powerpc Files generic to PowerPC architecture
148 /sandbox Files generic to HW-independent "sandbox"
149 /sh Files generic to SH architecture
150 /sparc Files generic to SPARC architecture
151 /x86 Files generic to x86 architecture
152 /api Machine/arch independent API for external apps
153 /board Board dependent files
154 /common Misc architecture independent functions
155 /configs Board default configuration files
156 /disk Code for disk drive partition handling
157 /doc Documentation (don't expect too much)
158 /drivers Commonly used device drivers
159 /dts Contains Makefile for building internal U-Boot fdt.
160 /examples Example code for standalone applications, etc.
161 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
162 /include Header Files
163 /lib Library routines generic to all architectures
164 /Licenses Various license files
166 /post Power On Self Test
167 /scripts Various build scripts and Makefiles
168 /test Various unit test files
169 /tools Tools to build S-Record or U-Boot images, etc.
171 Software Configuration:
172 =======================
174 Configuration is usually done using C preprocessor defines; the
175 rationale behind that is to avoid dead code whenever possible.
177 There are two classes of configuration variables:
179 * Configuration _OPTIONS_:
180 These are selectable by the user and have names beginning with
183 * Configuration _SETTINGS_:
184 These depend on the hardware etc. and should not be meddled with if
185 you don't know what you're doing; they have names beginning with
188 Previously, all configuration was done by hand, which involved creating
189 symbolic links and editing configuration files manually. More recently,
190 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
191 allowing you to use the "make menuconfig" command to configure your
195 Selection of Processor Architecture and Board Type:
196 ---------------------------------------------------
198 For all supported boards there are ready-to-use default
199 configurations available; just type "make <board_name>_defconfig".
201 Example: For a TQM823L module type:
204 make TQM823L_defconfig
206 Note: If you're looking for the default configuration file for a board
207 you're sure used to be there but is now missing, check the file
208 doc/README.scrapyard for a list of no longer supported boards.
213 U-Boot can be built natively to run on a Linux host using the 'sandbox'
214 board. This allows feature development which is not board- or architecture-
215 specific to be undertaken on a native platform. The sandbox is also used to
216 run some of U-Boot's tests.
218 See board/sandbox/README.sandbox for more details.
221 Board Initialisation Flow:
222 --------------------------
224 This is the intended start-up flow for boards. This should apply for both
225 SPL and U-Boot proper (i.e. they both follow the same rules).
227 Note: "SPL" stands for "Secondary Program Loader," which is explained in
228 more detail later in this file.
230 At present, SPL mostly uses a separate code path, but the function names
231 and roles of each function are the same. Some boards or architectures
232 may not conform to this. At least most ARM boards which use
233 CONFIG_SPL_FRAMEWORK conform to this.
235 Execution typically starts with an architecture-specific (and possibly
236 CPU-specific) start.S file, such as:
238 - arch/arm/cpu/armv7/start.S
239 - arch/powerpc/cpu/mpc83xx/start.S
240 - arch/mips/cpu/start.S
242 and so on. From there, three functions are called; the purpose and
243 limitations of each of these functions are described below.
246 - purpose: essential init to permit execution to reach board_init_f()
247 - no global_data or BSS
248 - there is no stack (ARMv7 may have one but it will soon be removed)
249 - must not set up SDRAM or use console
250 - must only do the bare minimum to allow execution to continue to
252 - this is almost never needed
253 - return normally from this function
256 - purpose: set up the machine ready for running board_init_r():
257 i.e. SDRAM and serial UART
258 - global_data is available
260 - BSS is not available, so you cannot use global/static variables,
261 only stack variables and global_data
263 Non-SPL-specific notes:
264 - dram_init() is called to set up DRAM. If already done in SPL this
268 - you can override the entire board_init_f() function with your own
270 - preloader_console_init() can be called here in extremis
271 - should set up SDRAM, and anything needed to make the UART work
272 - these is no need to clear BSS, it will be done by crt0.S
273 - must return normally from this function (don't call board_init_r()
276 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
277 this point the stack and global_data are relocated to below
278 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
282 - purpose: main execution, common code
283 - global_data is available
285 - BSS is available, all static/global variables can be used
286 - execution eventually continues to main_loop()
288 Non-SPL-specific notes:
289 - U-Boot is relocated to the top of memory and is now running from
293 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
294 CONFIG_SPL_STACK_R_ADDR points into SDRAM
295 - preloader_console_init() can be called here - typically this is
296 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
297 spl_board_init() function containing this call
298 - loads U-Boot or (in falcon mode) Linux
302 Configuration Options:
303 ----------------------
305 Configuration depends on the combination of board and CPU type; all
306 such information is kept in a configuration file
307 "include/configs/<board_name>.h".
309 Example: For a TQM823L module, all configuration settings are in
310 "include/configs/TQM823L.h".
313 Many of the options are named exactly as the corresponding Linux
314 kernel configuration options. The intention is to make it easier to
315 build a config tool - later.
318 The following options need to be configured:
320 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
322 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
324 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
325 Define exactly one, e.g. CONFIG_ATSTK1002
327 - CPU Module Type: (if CONFIG_COGENT is defined)
328 Define exactly one of
330 --- FIXME --- not tested yet:
331 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
332 CONFIG_CMA287_23, CONFIG_CMA287_50
334 - Motherboard Type: (if CONFIG_COGENT is defined)
335 Define exactly one of
336 CONFIG_CMA101, CONFIG_CMA102
338 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
339 Define one or more of
342 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
343 Define one or more of
344 CONFIG_LCD_HEARTBEAT - update a character position on
345 the LCD display every second with
348 - Marvell Family Member
349 CONFIG_SYS_MVFS - define it if you want to enable
350 multiple fs option at one time
351 for marvell soc family
353 - 8xx CPU Options: (if using an MPC8xx CPU)
354 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
355 get_gclk_freq() cannot work
356 e.g. if there is no 32KHz
357 reference PIT/RTC clock
358 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
361 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
362 CONFIG_SYS_8xx_CPUCLK_MIN
363 CONFIG_SYS_8xx_CPUCLK_MAX
364 CONFIG_8xx_CPUCLK_DEFAULT
365 See doc/README.MPC866
367 CONFIG_SYS_MEASURE_CPUCLK
369 Define this to measure the actual CPU clock instead
370 of relying on the correctness of the configured
371 values. Mostly useful for board bringup to make sure
372 the PLL is locked at the intended frequency. Note
373 that this requires a (stable) reference clock (32 kHz
374 RTC clock or CONFIG_SYS_8XX_XIN)
376 CONFIG_SYS_DELAYED_ICACHE
378 Define this option if you want to enable the
379 ICache only when Code runs from RAM.
384 Specifies that the core is a 64-bit PowerPC implementation (implements
385 the "64" category of the Power ISA). This is necessary for ePAPR
386 compliance, among other possible reasons.
388 CONFIG_SYS_FSL_TBCLK_DIV
390 Defines the core time base clock divider ratio compared to the
391 system clock. On most PQ3 devices this is 8, on newer QorIQ
392 devices it can be 16 or 32. The ratio varies from SoC to Soc.
394 CONFIG_SYS_FSL_PCIE_COMPAT
396 Defines the string to utilize when trying to match PCIe device
397 tree nodes for the given platform.
399 CONFIG_SYS_PPC_E500_DEBUG_TLB
401 Enables a temporary TLB entry to be used during boot to work
402 around limitations in e500v1 and e500v2 external debugger
403 support. This reduces the portions of the boot code where
404 breakpoints and single stepping do not work. The value of this
405 symbol should be set to the TLB1 entry to be used for this
408 CONFIG_SYS_FSL_ERRATUM_A004510
410 Enables a workaround for erratum A004510. If set,
411 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
414 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
415 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
417 Defines one or two SoC revisions (low 8 bits of SVR)
418 for which the A004510 workaround should be applied.
420 The rest of SVR is either not relevant to the decision
421 of whether the erratum is present (e.g. p2040 versus
422 p2041) or is implied by the build target, which controls
423 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
425 See Freescale App Note 4493 for more information about
428 CONFIG_A003399_NOR_WORKAROUND
429 Enables a workaround for IFC erratum A003399. It is only
430 required during NOR boot.
432 CONFIG_A008044_WORKAROUND
433 Enables a workaround for T1040/T1042 erratum A008044. It is only
434 required during NAND boot and valid for Rev 1.0 SoC revision
436 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
438 This is the value to write into CCSR offset 0x18600
439 according to the A004510 workaround.
441 CONFIG_SYS_FSL_DSP_DDR_ADDR
442 This value denotes start offset of DDR memory which is
443 connected exclusively to the DSP cores.
445 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
446 This value denotes start offset of M2 memory
447 which is directly connected to the DSP core.
449 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
450 This value denotes start offset of M3 memory which is directly
451 connected to the DSP core.
453 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
454 This value denotes start offset of DSP CCSR space.
456 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
457 Single Source Clock is clocking mode present in some of FSL SoC's.
458 In this mode, a single differential clock is used to supply
459 clocks to the sysclock, ddrclock and usbclock.
461 CONFIG_SYS_CPC_REINIT_F
462 This CONFIG is defined when the CPC is configured as SRAM at the
463 time of U-Boot entry and is required to be re-initialized.
466 Indicates this SoC supports deep sleep feature. If deep sleep is
467 supported, core will start to execute uboot when wakes up.
469 - Generic CPU options:
470 CONFIG_SYS_GENERIC_GLOBAL_DATA
471 Defines global data is initialized in generic board board_init_f().
472 If this macro is defined, global data is created and cleared in
473 generic board board_init_f(). Without this macro, architecture/board
474 should initialize global data before calling board_init_f().
476 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
478 Defines the endianess of the CPU. Implementation of those
479 values is arch specific.
482 Freescale DDR driver in use. This type of DDR controller is
483 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
486 CONFIG_SYS_FSL_DDR_ADDR
487 Freescale DDR memory-mapped register base.
489 CONFIG_SYS_FSL_DDR_EMU
490 Specify emulator support for DDR. Some DDR features such as
491 deskew training are not available.
493 CONFIG_SYS_FSL_DDRC_GEN1
494 Freescale DDR1 controller.
496 CONFIG_SYS_FSL_DDRC_GEN2
497 Freescale DDR2 controller.
499 CONFIG_SYS_FSL_DDRC_GEN3
500 Freescale DDR3 controller.
502 CONFIG_SYS_FSL_DDRC_GEN4
503 Freescale DDR4 controller.
505 CONFIG_SYS_FSL_DDRC_ARM_GEN3
506 Freescale DDR3 controller for ARM-based SoCs.
509 Board config to use DDR1. It can be enabled for SoCs with
510 Freescale DDR1 or DDR2 controllers, depending on the board
514 Board config to use DDR2. It can be eanbeld for SoCs with
515 Freescale DDR2 or DDR3 controllers, depending on the board
519 Board config to use DDR3. It can be enabled for SoCs with
520 Freescale DDR3 or DDR3L controllers.
523 Board config to use DDR3L. It can be enabled for SoCs with
527 Board config to use DDR4. It can be enabled for SoCs with
530 CONFIG_SYS_FSL_IFC_BE
531 Defines the IFC controller register space as Big Endian
533 CONFIG_SYS_FSL_IFC_LE
534 Defines the IFC controller register space as Little Endian
536 CONFIG_SYS_FSL_PBL_PBI
537 It enables addition of RCW (Power on reset configuration) in built image.
538 Please refer doc/README.pblimage for more details
540 CONFIG_SYS_FSL_PBL_RCW
541 It adds PBI(pre-boot instructions) commands in u-boot build image.
542 PBI commands can be used to configure SoC before it starts the execution.
543 Please refer doc/README.pblimage for more details
546 It adds a target to create boot binary having SPL binary in PBI format
547 concatenated with u-boot binary.
549 CONFIG_SYS_FSL_DDR_BE
550 Defines the DDR controller register space as Big Endian
552 CONFIG_SYS_FSL_DDR_LE
553 Defines the DDR controller register space as Little Endian
555 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
556 Physical address from the view of DDR controllers. It is the
557 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
558 it could be different for ARM SoCs.
560 CONFIG_SYS_FSL_DDR_INTLV_256B
561 DDR controller interleaving on 256-byte. This is a special
562 interleaving mode, handled by Dickens for Freescale layerscape
565 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
566 Number of controllers used as main memory.
568 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
569 Number of controllers used for other than main memory.
571 CONFIG_SYS_FSL_HAS_DP_DDR
572 Defines the SoC has DP-DDR used for DPAA.
574 CONFIG_SYS_FSL_SEC_BE
575 Defines the SEC controller register space as Big Endian
577 CONFIG_SYS_FSL_SEC_LE
578 Defines the SEC controller register space as Little Endian
580 - Intel Monahans options:
581 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
583 Defines the Monahans run mode to oscillator
584 ratio. Valid values are 8, 16, 24, 31. The core
585 frequency is this value multiplied by 13 MHz.
587 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
589 Defines the Monahans turbo mode to oscillator
590 ratio. Valid values are 1 (default if undefined) and
591 2. The core frequency as calculated above is multiplied
595 CONFIG_SYS_INIT_SP_OFFSET
597 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
598 pointer. This is needed for the temporary stack before
601 CONFIG_SYS_MIPS_CACHE_MODE
603 Cache operation mode for the MIPS CPU.
604 See also arch/mips/include/asm/mipsregs.h.
606 CONF_CM_CACHABLE_NO_WA
609 CONF_CM_CACHABLE_NONCOHERENT
613 CONF_CM_CACHABLE_ACCELERATED
615 CONFIG_SYS_XWAY_EBU_BOOTCFG
617 Special option for Lantiq XWAY SoCs for booting from NOR flash.
618 See also arch/mips/cpu/mips32/start.S.
620 CONFIG_XWAY_SWAP_BYTES
622 Enable compilation of tools/xway-swap-bytes needed for Lantiq
623 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
624 be swapped if a flash programmer is used.
627 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
629 Select high exception vectors of the ARM core, e.g., do not
630 clear the V bit of the c1 register of CP15.
632 CONFIG_SYS_THUMB_BUILD
634 Use this flag to build U-Boot using the Thumb instruction
635 set for ARM architectures. Thumb instruction set provides
636 better code density. For ARM architectures that support
637 Thumb2 this flag will result in Thumb2 code generated by
640 CONFIG_ARM_ERRATA_716044
641 CONFIG_ARM_ERRATA_742230
642 CONFIG_ARM_ERRATA_743622
643 CONFIG_ARM_ERRATA_751472
644 CONFIG_ARM_ERRATA_761320
645 CONFIG_ARM_ERRATA_773022
646 CONFIG_ARM_ERRATA_774769
647 CONFIG_ARM_ERRATA_794072
649 If set, the workarounds for these ARM errata are applied early
650 during U-Boot startup. Note that these options force the
651 workarounds to be applied; no CPU-type/version detection
652 exists, unlike the similar options in the Linux kernel. Do not
653 set these options unless they apply!
656 Generic timer clock source frequency.
658 COUNTER_FREQUENCY_REAL
659 Generic timer clock source frequency if the real clock is
660 different from COUNTER_FREQUENCY, and can only be determined
663 NOTE: The following can be machine specific errata. These
664 do have ability to provide rudimentary version and machine
665 specific checks, but expect no product checks.
666 CONFIG_ARM_ERRATA_430973
667 CONFIG_ARM_ERRATA_454179
668 CONFIG_ARM_ERRATA_621766
669 CONFIG_ARM_ERRATA_798870
670 CONFIG_ARM_ERRATA_801819
673 CONFIG_TEGRA_SUPPORT_NON_SECURE
675 Support executing U-Boot in non-secure (NS) mode. Certain
676 impossible actions will be skipped if the CPU is in NS mode,
677 such as ARM architectural timer initialization.
679 - Linux Kernel Interface:
682 U-Boot stores all clock information in Hz
683 internally. For binary compatibility with older Linux
684 kernels (which expect the clocks passed in the
685 bd_info data to be in MHz) the environment variable
686 "clocks_in_mhz" can be defined so that U-Boot
687 converts clock data to MHZ before passing it to the
689 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
690 "clocks_in_mhz=1" is automatically included in the
693 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
695 When transferring memsize parameter to Linux, some versions
696 expect it to be in bytes, others in MB.
697 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
701 New kernel versions are expecting firmware settings to be
702 passed using flattened device trees (based on open firmware
706 * New libfdt-based support
707 * Adds the "fdt" command
708 * The bootm command automatically updates the fdt
710 OF_CPU - The proper name of the cpus node (only required for
711 MPC512X and MPC5xxx based boards).
712 OF_SOC - The proper name of the soc node (only required for
713 MPC512X and MPC5xxx based boards).
714 OF_TBCLK - The timebase frequency.
715 OF_STDOUT_PATH - The path to the console device
717 boards with QUICC Engines require OF_QE to set UCC MAC
720 CONFIG_OF_BOARD_SETUP
722 Board code has addition modification that it wants to make
723 to the flat device tree before handing it off to the kernel
725 CONFIG_OF_SYSTEM_SETUP
727 Other code has addition modification that it wants to make
728 to the flat device tree before handing it off to the kernel.
729 This causes ft_system_setup() to be called before booting
734 This define fills in the correct boot CPU in the boot
735 param header, the default value is zero if undefined.
739 U-Boot can detect if an IDE device is present or not.
740 If not, and this new config option is activated, U-Boot
741 removes the ATA node from the DTS before booting Linux,
742 so the Linux IDE driver does not probe the device and
743 crash. This is needed for buggy hardware (uc101) where
744 no pull down resistor is connected to the signal IDE5V_DD7.
746 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
748 This setting is mandatory for all boards that have only one
749 machine type and must be used to specify the machine type
750 number as it appears in the ARM machine registry
751 (see http://www.arm.linux.org.uk/developer/machines/).
752 Only boards that have multiple machine types supported
753 in a single configuration file and the machine type is
754 runtime discoverable, do not have to use this setting.
756 - vxWorks boot parameters:
758 bootvx constructs a valid bootline using the following
759 environments variables: bootdev, bootfile, ipaddr, netmask,
760 serverip, gatewayip, hostname, othbootargs.
761 It loads the vxWorks image pointed bootfile.
763 Note: If a "bootargs" environment is defined, it will overwride
764 the defaults discussed just above.
766 - Cache Configuration:
767 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
768 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
769 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
771 - Cache Configuration for ARM:
772 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
774 CONFIG_SYS_PL310_BASE - Physical base address of PL310
775 controller register space
780 Define this if you want support for Amba PrimeCell PL010 UARTs.
784 Define this if you want support for Amba PrimeCell PL011 UARTs.
788 If you have Amba PrimeCell PL011 UARTs, set this variable to
789 the clock speed of the UARTs.
793 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
794 define this to a list of base addresses for each (supported)
795 port. See e.g. include/configs/versatile.h
797 CONFIG_SERIAL_HW_FLOW_CONTROL
799 Define this variable to enable hw flow control in serial driver.
800 Current user of this option is drivers/serial/nsl16550.c driver
803 Depending on board, define exactly one serial port
804 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
805 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
806 console by defining CONFIG_8xx_CONS_NONE
808 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
809 port routines must be defined elsewhere
810 (i.e. serial_init(), serial_getc(), ...)
813 Enables console device for a color framebuffer. Needs following
814 defines (cf. smiLynxEM, i8042)
815 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
817 VIDEO_HW_RECTFILL graphic chip supports
820 VIDEO_HW_BITBLT graphic chip supports
821 bit-blit (cf. smiLynxEM)
822 VIDEO_VISIBLE_COLS visible pixel columns
824 VIDEO_VISIBLE_ROWS visible pixel rows
825 VIDEO_PIXEL_SIZE bytes per pixel
826 VIDEO_DATA_FORMAT graphic data format
827 (0-5, cf. cfb_console.c)
828 VIDEO_FB_ADRS framebuffer address
829 VIDEO_KBD_INIT_FCT keyboard int fct
830 (i.e. rx51_kp_init())
831 VIDEO_TSTC_FCT test char fct
833 VIDEO_GETC_FCT get char fct
835 CONFIG_VIDEO_LOGO display Linux logo in
837 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
838 linux_logo.h for logo.
839 Requires CONFIG_VIDEO_LOGO
840 CONFIG_CONSOLE_EXTRA_INFO
841 additional board info beside
844 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
845 a limited number of ANSI escape sequences (cursor control,
846 erase functions and limited graphics rendition control).
848 When CONFIG_CFB_CONSOLE is defined, video console is
849 default i/o. Serial console can be forced with
850 environment 'console=serial'.
852 When CONFIG_SILENT_CONSOLE is defined, all console
853 messages (by U-Boot and Linux!) can be silenced with
854 the "silent" environment variable. See
855 doc/README.silent for more information.
857 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
859 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
863 CONFIG_BAUDRATE - in bps
864 Select one of the baudrates listed in
865 CONFIG_SYS_BAUDRATE_TABLE, see below.
866 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
868 - Console Rx buffer length
869 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
870 the maximum receive buffer length for the SMC.
871 This option is actual only for 82xx and 8xx possible.
872 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
873 must be defined, to setup the maximum idle timeout for
876 - Pre-Console Buffer:
877 Prior to the console being initialised (i.e. serial UART
878 initialised etc) all console output is silently discarded.
879 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
880 buffer any console messages prior to the console being
881 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
882 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
883 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
884 bytes are output before the console is initialised, the
885 earlier bytes are discarded.
887 Note that when printing the buffer a copy is made on the
888 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
890 'Sane' compilers will generate smaller code if
891 CONFIG_PRE_CON_BUF_SZ is a power of 2
893 - Boot Delay: CONFIG_BOOTDELAY - in seconds
894 Delay before automatically booting the default image;
895 set to -1 to disable autoboot.
896 set to -2 to autoboot with no delay and not check for abort
897 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
899 See doc/README.autoboot for these options that
900 work with CONFIG_BOOTDELAY. None are required.
901 CONFIG_BOOT_RETRY_TIME
902 CONFIG_BOOT_RETRY_MIN
903 CONFIG_AUTOBOOT_KEYED
904 CONFIG_AUTOBOOT_PROMPT
905 CONFIG_AUTOBOOT_DELAY_STR
906 CONFIG_AUTOBOOT_STOP_STR
907 CONFIG_ZERO_BOOTDELAY_CHECK
908 CONFIG_RESET_TO_RETRY
912 Only needed when CONFIG_BOOTDELAY is enabled;
913 define a command string that is automatically executed
914 when no character is read on the console interface
915 within "Boot Delay" after reset.
918 This can be used to pass arguments to the bootm
919 command. The value of CONFIG_BOOTARGS goes into the
920 environment value "bootargs".
922 CONFIG_RAMBOOT and CONFIG_NFSBOOT
923 The value of these goes into the environment as
924 "ramboot" and "nfsboot" respectively, and can be used
925 as a convenience, when switching between booting from
929 CONFIG_BOOTCOUNT_LIMIT
930 Implements a mechanism for detecting a repeating reboot
932 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
935 If no softreset save registers are found on the hardware
936 "bootcount" is stored in the environment. To prevent a
937 saveenv on all reboots, the environment variable
938 "upgrade_available" is used. If "upgrade_available" is
939 0, "bootcount" is always 0, if "upgrade_available" is
940 1 "bootcount" is incremented in the environment.
941 So the Userspace Applikation must set the "upgrade_available"
942 and "bootcount" variable to 0, if a boot was successfully.
947 When this option is #defined, the existence of the
948 environment variable "preboot" will be checked
949 immediately before starting the CONFIG_BOOTDELAY
950 countdown and/or running the auto-boot command resp.
951 entering interactive mode.
953 This feature is especially useful when "preboot" is
954 automatically generated or modified. For an example
955 see the LWMON board specific code: here "preboot" is
956 modified when the user holds down a certain
957 combination of keys on the (special) keyboard when
960 - Serial Download Echo Mode:
962 If defined to 1, all characters received during a
963 serial download (using the "loads" command) are
964 echoed back. This might be needed by some terminal
965 emulations (like "cu"), but may as well just take
966 time on others. This setting #define's the initial
967 value of the "loads_echo" environment variable.
969 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
971 Select one of the baudrates listed in
972 CONFIG_SYS_BAUDRATE_TABLE, see below.
975 Monitor commands can be included or excluded
976 from the build by using the #include files
977 <config_cmd_all.h> and #undef'ing unwanted
978 commands, or adding #define's for wanted commands.
980 The default command configuration includes all commands
981 except those marked below with a "*".
983 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
984 CONFIG_CMD_ASKENV * ask for env variable
985 CONFIG_CMD_BDI bdinfo
986 CONFIG_CMD_BEDBUG * Include BedBug Debugger
987 CONFIG_CMD_BMP * BMP support
988 CONFIG_CMD_BSP * Board specific commands
989 CONFIG_CMD_BOOTD bootd
990 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
991 CONFIG_CMD_CACHE * icache, dcache
992 CONFIG_CMD_CLK * clock command support
993 CONFIG_CMD_CONSOLE coninfo
994 CONFIG_CMD_CRC32 * crc32
995 CONFIG_CMD_DATE * support for RTC, date/time...
996 CONFIG_CMD_DHCP * DHCP support
997 CONFIG_CMD_DIAG * Diagnostics
998 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
999 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1000 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1001 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1002 CONFIG_CMD_DTT * Digital Therm and Thermostat
1003 CONFIG_CMD_ECHO echo arguments
1004 CONFIG_CMD_EDITENV edit env variable
1005 CONFIG_CMD_EEPROM * EEPROM read/write support
1006 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
1007 CONFIG_CMD_ELF * bootelf, bootvx
1008 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1009 CONFIG_CMD_ENV_FLAGS * display details about env flags
1010 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1011 CONFIG_CMD_EXPORTENV * export the environment
1012 CONFIG_CMD_EXT2 * ext2 command support
1013 CONFIG_CMD_EXT4 * ext4 command support
1014 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1015 that work for multiple fs types
1016 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1017 CONFIG_CMD_SAVEENV saveenv
1018 CONFIG_CMD_FDC * Floppy Disk Support
1019 CONFIG_CMD_FAT * FAT command support
1020 CONFIG_CMD_FLASH flinfo, erase, protect
1021 CONFIG_CMD_FPGA FPGA device initialization support
1022 CONFIG_CMD_FUSE * Device fuse support
1023 CONFIG_CMD_GETTIME * Get time since boot
1024 CONFIG_CMD_GO * the 'go' command (exec code)
1025 CONFIG_CMD_GREPENV * search environment
1026 CONFIG_CMD_HASH * calculate hash / digest
1027 CONFIG_CMD_I2C * I2C serial bus support
1028 CONFIG_CMD_IDE * IDE harddisk support
1029 CONFIG_CMD_IMI iminfo
1030 CONFIG_CMD_IMLS List all images found in NOR flash
1031 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1032 CONFIG_CMD_IMMAP * IMMR dump support
1033 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1034 CONFIG_CMD_IMPORTENV * import an environment
1035 CONFIG_CMD_INI * import data from an ini file into the env
1036 CONFIG_CMD_IRQ * irqinfo
1037 CONFIG_CMD_ITEST Integer/string test of 2 values
1038 CONFIG_CMD_JFFS2 * JFFS2 Support
1039 CONFIG_CMD_KGDB * kgdb
1040 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1041 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1043 CONFIG_CMD_LOADB loadb
1044 CONFIG_CMD_LOADS loads
1045 CONFIG_CMD_MD5SUM * print md5 message digest
1046 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1047 CONFIG_CMD_MEMINFO * Display detailed memory information
1048 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1050 CONFIG_CMD_MEMTEST * mtest
1051 CONFIG_CMD_MISC Misc functions like sleep etc
1052 CONFIG_CMD_MMC * MMC memory mapped support
1053 CONFIG_CMD_MII * MII utility commands
1054 CONFIG_CMD_MTDPARTS * MTD partition support
1055 CONFIG_CMD_NAND * NAND support
1056 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1057 CONFIG_CMD_NFS NFS support
1058 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1059 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1060 CONFIG_CMD_PCI * pciinfo
1061 CONFIG_CMD_PCMCIA * PCMCIA support
1062 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1064 CONFIG_CMD_PORTIO * Port I/O
1065 CONFIG_CMD_READ * Read raw data from partition
1066 CONFIG_CMD_REGINFO * Register dump
1067 CONFIG_CMD_RUN run command in env variable
1068 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1069 CONFIG_CMD_SAVES * save S record dump
1070 CONFIG_SCSI * SCSI Support
1071 CONFIG_CMD_SDRAM * print SDRAM configuration information
1072 (requires CONFIG_CMD_I2C)
1073 CONFIG_CMD_SETGETDCR Support for DCR Register access
1075 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1076 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1077 (requires CONFIG_CMD_MEMORY)
1078 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1079 CONFIG_CMD_SOURCE "source" command Support
1080 CONFIG_CMD_SPI * SPI serial bus support
1081 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1082 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1083 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1084 CONFIG_CMD_TIMER * access to the system tick timer
1085 CONFIG_CMD_USB * USB support
1086 CONFIG_CMD_CDP * Cisco Discover Protocol support
1087 CONFIG_CMD_MFSL * Microblaze FSL support
1088 CONFIG_CMD_XIMG Load part of Multi Image
1089 CONFIG_CMD_UUID * Generate random UUID or GUID string
1091 EXAMPLE: If you want all functions except of network
1092 support you can write:
1094 #include "config_cmd_all.h"
1095 #undef CONFIG_CMD_NET
1098 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1100 Note: Don't enable the "icache" and "dcache" commands
1101 (configuration option CONFIG_CMD_CACHE) unless you know
1102 what you (and your U-Boot users) are doing. Data
1103 cache cannot be enabled on systems like the 8xx or
1104 8260 (where accesses to the IMMR region must be
1105 uncached), and it cannot be disabled on all other
1106 systems where we (mis-) use the data cache to hold an
1107 initial stack and some data.
1110 XXX - this list needs to get updated!
1112 - Removal of commands
1113 If no commands are needed to boot, you can disable
1114 CONFIG_CMDLINE to remove them. In this case, the command line
1115 will not be available, and when U-Boot wants to execute the
1116 boot command (on start-up) it will call board_run_command()
1117 instead. This can reduce image size significantly for very
1118 simple boot procedures.
1120 - Regular expression support:
1122 If this variable is defined, U-Boot is linked against
1123 the SLRE (Super Light Regular Expression) library,
1124 which adds regex support to some commands, as for
1125 example "env grep" and "setexpr".
1129 If this variable is defined, U-Boot will use a device tree
1130 to configure its devices, instead of relying on statically
1131 compiled #defines in the board file. This option is
1132 experimental and only available on a few boards. The device
1133 tree is available in the global data as gd->fdt_blob.
1135 U-Boot needs to get its device tree from somewhere. This can
1136 be done using one of the two options below:
1139 If this variable is defined, U-Boot will embed a device tree
1140 binary in its image. This device tree file should be in the
1141 board directory and called <soc>-<board>.dts. The binary file
1142 is then picked up in board_init_f() and made available through
1143 the global data structure as gd->blob.
1146 If this variable is defined, U-Boot will build a device tree
1147 binary. It will be called u-boot.dtb. Architecture-specific
1148 code will locate it at run-time. Generally this works by:
1150 cat u-boot.bin u-boot.dtb >image.bin
1152 and in fact, U-Boot does this for you, creating a file called
1153 u-boot-dtb.bin which is useful in the common case. You can
1154 still use the individual files if you need something more
1159 If this variable is defined, it enables watchdog
1160 support for the SoC. There must be support in the SoC
1161 specific code for a watchdog. For the 8xx and 8260
1162 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1163 register. When supported for a specific SoC is
1164 available, then no further board specific code should
1165 be needed to use it.
1168 When using a watchdog circuitry external to the used
1169 SoC, then define this variable and provide board
1170 specific code for the "hw_watchdog_reset" function.
1172 CONFIG_AT91_HW_WDT_TIMEOUT
1173 specify the timeout in seconds. default 2 seconds.
1176 CONFIG_VERSION_VARIABLE
1177 If this variable is defined, an environment variable
1178 named "ver" is created by U-Boot showing the U-Boot
1179 version as printed by the "version" command.
1180 Any change to this variable will be reverted at the
1185 When CONFIG_CMD_DATE is selected, the type of the RTC
1186 has to be selected, too. Define exactly one of the
1189 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1190 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1191 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1192 CONFIG_RTC_MC146818 - use MC146818 RTC
1193 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1194 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1195 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1196 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1197 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1198 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1199 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1200 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1201 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1204 Note that if the RTC uses I2C, then the I2C interface
1205 must also be configured. See I2C Support, below.
1208 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1210 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1211 chip-ngpio pairs that tell the PCA953X driver the number of
1212 pins supported by a particular chip.
1214 Note that if the GPIO device uses I2C, then the I2C interface
1215 must also be configured. See I2C Support, below.
1218 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1219 accesses and can checksum them or write a list of them out
1220 to memory. See the 'iotrace' command for details. This is
1221 useful for testing device drivers since it can confirm that
1222 the driver behaves the same way before and after a code
1223 change. Currently this is supported on sandbox and arm. To
1224 add support for your architecture, add '#include <iotrace.h>'
1225 to the bottom of arch/<arch>/include/asm/io.h and test.
1227 Example output from the 'iotrace stats' command is below.
1228 Note that if the trace buffer is exhausted, the checksum will
1229 still continue to operate.
1232 Start: 10000000 (buffer start address)
1233 Size: 00010000 (buffer size)
1234 Offset: 00000120 (current buffer offset)
1235 Output: 10000120 (start + offset)
1236 Count: 00000018 (number of trace records)
1237 CRC32: 9526fb66 (CRC32 of all trace records)
1239 - Timestamp Support:
1241 When CONFIG_TIMESTAMP is selected, the timestamp
1242 (date and time) of an image is printed by image
1243 commands like bootm or iminfo. This option is
1244 automatically enabled when you select CONFIG_CMD_DATE .
1246 - Partition Labels (disklabels) Supported:
1247 Zero or more of the following:
1248 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1249 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1250 Intel architecture, USB sticks, etc.
1251 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1252 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1253 bootloader. Note 2TB partition limit; see
1255 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1257 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1258 CONFIG_SCSI) you must configure support for at
1259 least one non-MTD partition type as well.
1262 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1263 board configurations files but used nowhere!
1265 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1266 be performed by calling the function
1267 ide_set_reset(int reset)
1268 which has to be defined in a board specific file
1273 Set this to enable ATAPI support.
1278 Set this to enable support for disks larger than 137GB
1279 Also look at CONFIG_SYS_64BIT_LBA.
1280 Whithout these , LBA48 support uses 32bit variables and will 'only'
1281 support disks up to 2.1TB.
1283 CONFIG_SYS_64BIT_LBA:
1284 When enabled, makes the IDE subsystem use 64bit sector addresses.
1288 At the moment only there is only support for the
1289 SYM53C8XX SCSI controller; define
1290 CONFIG_SCSI_SYM53C8XX to enable it.
1292 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1293 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1294 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1295 maximum numbers of LUNs, SCSI ID's and target
1297 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1299 The environment variable 'scsidevs' is set to the number of
1300 SCSI devices found during the last scan.
1302 - NETWORK Support (PCI):
1304 Support for Intel 8254x/8257x gigabit chips.
1307 Utility code for direct access to the SPI bus on Intel 8257x.
1308 This does not do anything useful unless you set at least one
1309 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1311 CONFIG_E1000_SPI_GENERIC
1312 Allow generic access to the SPI bus on the Intel 8257x, for
1313 example with the "sspi" command.
1316 Management command for E1000 devices. When used on devices
1317 with SPI support you can reprogram the EEPROM from U-Boot.
1320 Support for Intel 82557/82559/82559ER chips.
1321 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1322 write routine for first time initialisation.
1325 Support for Digital 2114x chips.
1326 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1327 modem chip initialisation (KS8761/QS6611).
1330 Support for National dp83815 chips.
1333 Support for National dp8382[01] gigabit chips.
1335 - NETWORK Support (other):
1337 CONFIG_DRIVER_AT91EMAC
1338 Support for AT91RM9200 EMAC.
1341 Define this to use reduced MII inteface
1343 CONFIG_DRIVER_AT91EMAC_QUIET
1344 If this defined, the driver is quiet.
1345 The driver doen't show link status messages.
1347 CONFIG_CALXEDA_XGMAC
1348 Support for the Calxeda XGMAC device
1351 Support for SMSC's LAN91C96 chips.
1353 CONFIG_LAN91C96_BASE
1354 Define this to hold the physical address
1355 of the LAN91C96's I/O space
1357 CONFIG_LAN91C96_USE_32_BIT
1358 Define this to enable 32 bit addressing
1361 Support for SMSC's LAN91C111 chip
1363 CONFIG_SMC91111_BASE
1364 Define this to hold the physical address
1365 of the device (I/O space)
1367 CONFIG_SMC_USE_32_BIT
1368 Define this if data bus is 32 bits
1370 CONFIG_SMC_USE_IOFUNCS
1371 Define this to use i/o functions instead of macros
1372 (some hardware wont work with macros)
1374 CONFIG_DRIVER_TI_EMAC
1375 Support for davinci emac
1377 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1378 Define this if you have more then 3 PHYs.
1381 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1383 CONFIG_FTGMAC100_EGIGA
1384 Define this to use GE link update with gigabit PHY.
1385 Define this if FTGMAC100 is connected to gigabit PHY.
1386 If your system has 10/100 PHY only, it might not occur
1387 wrong behavior. Because PHY usually return timeout or
1388 useless data when polling gigabit status and gigabit
1389 control registers. This behavior won't affect the
1390 correctnessof 10/100 link speed update.
1393 Support for SMSC's LAN911x and LAN921x chips
1396 Define this to hold the physical address
1397 of the device (I/O space)
1399 CONFIG_SMC911X_32_BIT
1400 Define this if data bus is 32 bits
1402 CONFIG_SMC911X_16_BIT
1403 Define this if data bus is 16 bits. If your processor
1404 automatically converts one 32 bit word to two 16 bit
1405 words you may also try CONFIG_SMC911X_32_BIT.
1408 Support for Renesas on-chip Ethernet controller
1410 CONFIG_SH_ETHER_USE_PORT
1411 Define the number of ports to be used
1413 CONFIG_SH_ETHER_PHY_ADDR
1414 Define the ETH PHY's address
1416 CONFIG_SH_ETHER_CACHE_WRITEBACK
1417 If this option is set, the driver enables cache flush.
1421 Support for PWM modul on the imx6.
1425 Support TPM devices.
1427 CONFIG_TPM_TIS_INFINEON
1428 Support for Infineon i2c bus TPM devices. Only one device
1429 per system is supported at this time.
1431 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1432 Define the burst count bytes upper limit
1435 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1437 CONFIG_TPM_ST33ZP24_I2C
1438 Support for STMicroelectronics ST33ZP24 I2C devices.
1439 Requires TPM_ST33ZP24 and I2C.
1441 CONFIG_TPM_ST33ZP24_SPI
1442 Support for STMicroelectronics ST33ZP24 SPI devices.
1443 Requires TPM_ST33ZP24 and SPI.
1445 CONFIG_TPM_ATMEL_TWI
1446 Support for Atmel TWI TPM device. Requires I2C support.
1449 Support for generic parallel port TPM devices. Only one device
1450 per system is supported at this time.
1452 CONFIG_TPM_TIS_BASE_ADDRESS
1453 Base address where the generic TPM device is mapped
1454 to. Contemporary x86 systems usually map it at
1458 Add tpm monitor functions.
1459 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1460 provides monitor access to authorized functions.
1463 Define this to enable the TPM support library which provides
1464 functional interfaces to some TPM commands.
1465 Requires support for a TPM device.
1467 CONFIG_TPM_AUTH_SESSIONS
1468 Define this to enable authorized functions in the TPM library.
1469 Requires CONFIG_TPM and CONFIG_SHA1.
1472 At the moment only the UHCI host controller is
1473 supported (PIP405, MIP405, MPC5200); define
1474 CONFIG_USB_UHCI to enable it.
1475 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1476 and define CONFIG_USB_STORAGE to enable the USB
1479 Supported are USB Keyboards and USB Floppy drives
1481 MPC5200 USB requires additional defines:
1483 for 528 MHz Clock: 0x0001bbbb
1487 for differential drivers: 0x00001000
1488 for single ended drivers: 0x00005000
1489 for differential drivers on PSC3: 0x00000100
1490 for single ended drivers on PSC3: 0x00004100
1491 CONFIG_SYS_USB_EVENT_POLL
1492 May be defined to allow interrupt polling
1493 instead of using asynchronous interrupts
1495 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1496 txfilltuning field in the EHCI controller on reset.
1498 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1499 HW module registers.
1502 Define the below if you wish to use the USB console.
1503 Once firmware is rebuilt from a serial console issue the
1504 command "setenv stdin usbtty; setenv stdout usbtty" and
1505 attach your USB cable. The Unix command "dmesg" should print
1506 it has found a new device. The environment variable usbtty
1507 can be set to gserial or cdc_acm to enable your device to
1508 appear to a USB host as a Linux gserial device or a
1509 Common Device Class Abstract Control Model serial device.
1510 If you select usbtty = gserial you should be able to enumerate
1512 # modprobe usbserial vendor=0xVendorID product=0xProductID
1513 else if using cdc_acm, simply setting the environment
1514 variable usbtty to be cdc_acm should suffice. The following
1515 might be defined in YourBoardName.h
1518 Define this to build a UDC device
1521 Define this to have a tty type of device available to
1522 talk to the UDC device
1525 Define this to enable the high speed support for usb
1526 device and usbtty. If this feature is enabled, a routine
1527 int is_usbd_high_speed(void)
1528 also needs to be defined by the driver to dynamically poll
1529 whether the enumeration has succeded at high speed or full
1532 CONFIG_SYS_CONSOLE_IS_IN_ENV
1533 Define this if you want stdin, stdout &/or stderr to
1537 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1538 Derive USB clock from external clock "blah"
1539 - CONFIG_SYS_USB_EXTC_CLK 0x02
1541 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1542 Derive USB clock from brgclk
1543 - CONFIG_SYS_USB_BRG_CLK 0x04
1545 If you have a USB-IF assigned VendorID then you may wish to
1546 define your own vendor specific values either in BoardName.h
1547 or directly in usbd_vendor_info.h. If you don't define
1548 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1549 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1550 should pretend to be a Linux device to it's target host.
1552 CONFIG_USBD_MANUFACTURER
1553 Define this string as the name of your company for
1554 - CONFIG_USBD_MANUFACTURER "my company"
1556 CONFIG_USBD_PRODUCT_NAME
1557 Define this string as the name of your product
1558 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1560 CONFIG_USBD_VENDORID
1561 Define this as your assigned Vendor ID from the USB
1562 Implementors Forum. This *must* be a genuine Vendor ID
1563 to avoid polluting the USB namespace.
1564 - CONFIG_USBD_VENDORID 0xFFFF
1566 CONFIG_USBD_PRODUCTID
1567 Define this as the unique Product ID
1569 - CONFIG_USBD_PRODUCTID 0xFFFF
1571 - ULPI Layer Support:
1572 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1573 the generic ULPI layer. The generic layer accesses the ULPI PHY
1574 via the platform viewport, so you need both the genric layer and
1575 the viewport enabled. Currently only Chipidea/ARC based
1576 viewport is supported.
1577 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1578 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1579 If your ULPI phy needs a different reference clock than the
1580 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1581 the appropriate value in Hz.
1584 The MMC controller on the Intel PXA is supported. To
1585 enable this define CONFIG_MMC. The MMC can be
1586 accessed from the boot prompt by mapping the device
1587 to physical memory similar to flash. Command line is
1588 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1589 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1592 Support for Renesas on-chip MMCIF controller
1594 CONFIG_SH_MMCIF_ADDR
1595 Define the base address of MMCIF registers
1598 Define the clock frequency for MMCIF
1601 Enable the generic MMC driver
1603 CONFIG_SUPPORT_EMMC_BOOT
1604 Enable some additional features of the eMMC boot partitions.
1606 CONFIG_SUPPORT_EMMC_RPMB
1607 Enable the commands for reading, writing and programming the
1608 key for the Replay Protection Memory Block partition in eMMC.
1610 - USB Device Firmware Update (DFU) class support:
1611 CONFIG_USB_FUNCTION_DFU
1612 This enables the USB portion of the DFU USB class
1615 This enables the command "dfu" which is used to have
1616 U-Boot create a DFU class device via USB. This command
1617 requires that the "dfu_alt_info" environment variable be
1618 set and define the alt settings to expose to the host.
1621 This enables support for exposing (e)MMC devices via DFU.
1624 This enables support for exposing NAND devices via DFU.
1627 This enables support for exposing RAM via DFU.
1628 Note: DFU spec refer to non-volatile memory usage, but
1629 allow usages beyond the scope of spec - here RAM usage,
1630 one that would help mostly the developer.
1632 CONFIG_SYS_DFU_DATA_BUF_SIZE
1633 Dfu transfer uses a buffer before writing data to the
1634 raw storage device. Make the size (in bytes) of this buffer
1635 configurable. The size of this buffer is also configurable
1636 through the "dfu_bufsiz" environment variable.
1638 CONFIG_SYS_DFU_MAX_FILE_SIZE
1639 When updating files rather than the raw storage device,
1640 we use a static buffer to copy the file into and then write
1641 the buffer once we've been given the whole file. Define
1642 this to the maximum filesize (in bytes) for the buffer.
1643 Default is 4 MiB if undefined.
1645 DFU_DEFAULT_POLL_TIMEOUT
1646 Poll timeout [ms], is the timeout a device can send to the
1647 host. The host must wait for this timeout before sending
1648 a subsequent DFU_GET_STATUS request to the device.
1650 DFU_MANIFEST_POLL_TIMEOUT
1651 Poll timeout [ms], which the device sends to the host when
1652 entering dfuMANIFEST state. Host waits this timeout, before
1653 sending again an USB request to the device.
1655 - USB Device Android Fastboot support:
1656 CONFIG_USB_FUNCTION_FASTBOOT
1657 This enables the USB part of the fastboot gadget
1660 This enables the command "fastboot" which enables the Android
1661 fastboot mode for the platform's USB device. Fastboot is a USB
1662 protocol for downloading images, flashing and device control
1663 used on Android devices.
1664 See doc/README.android-fastboot for more information.
1666 CONFIG_ANDROID_BOOT_IMAGE
1667 This enables support for booting images which use the Android
1668 image format header.
1670 CONFIG_FASTBOOT_BUF_ADDR
1671 The fastboot protocol requires a large memory buffer for
1672 downloads. Define this to the starting RAM address to use for
1675 CONFIG_FASTBOOT_BUF_SIZE
1676 The fastboot protocol requires a large memory buffer for
1677 downloads. This buffer should be as large as possible for a
1678 platform. Define this to the size available RAM for fastboot.
1680 CONFIG_FASTBOOT_FLASH
1681 The fastboot protocol includes a "flash" command for writing
1682 the downloaded image to a non-volatile storage device. Define
1683 this to enable the "fastboot flash" command.
1685 CONFIG_FASTBOOT_FLASH_MMC_DEV
1686 The fastboot "flash" command requires additional information
1687 regarding the non-volatile storage device. Define this to
1688 the eMMC device that fastboot should use to store the image.
1690 CONFIG_FASTBOOT_GPT_NAME
1691 The fastboot "flash" command supports writing the downloaded
1692 image to the Protective MBR and the Primary GUID Partition
1693 Table. (Additionally, this downloaded image is post-processed
1694 to generate and write the Backup GUID Partition Table.)
1695 This occurs when the specified "partition name" on the
1696 "fastboot flash" command line matches this value.
1697 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1699 - Journaling Flash filesystem support:
1700 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1701 CONFIG_JFFS2_NAND_DEV
1702 Define these for a default partition on a NAND device
1704 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1705 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1706 Define these for a default partition on a NOR device
1708 CONFIG_SYS_JFFS_CUSTOM_PART
1709 Define this to create an own partition. You have to provide a
1710 function struct part_info* jffs2_part_info(int part_num)
1712 If you define only one JFFS2 partition you may also want to
1713 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1714 to disable the command chpart. This is the default when you
1715 have not defined a custom partition
1717 - FAT(File Allocation Table) filesystem write function support:
1720 Define this to enable support for saving memory data as a
1721 file in FAT formatted partition.
1723 This will also enable the command "fatwrite" enabling the
1724 user to write files to FAT.
1726 CBFS (Coreboot Filesystem) support
1729 Define this to enable support for reading from a Coreboot
1730 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1733 - FAT(File Allocation Table) filesystem cluster size:
1734 CONFIG_FS_FAT_MAX_CLUSTSIZE
1736 Define the max cluster size for fat operations else
1737 a default value of 65536 will be defined.
1740 See Kconfig help for available keyboard drivers.
1744 Define this to enable a custom keyboard support.
1745 This simply calls drv_keyboard_init() which must be
1746 defined in your board-specific files. This option is deprecated
1747 and is only used by novena. For new boards, use driver model
1753 Define this to enable video support (for output to
1756 CONFIG_VIDEO_CT69000
1758 Enable Chips & Technologies 69000 Video chip
1760 CONFIG_VIDEO_SMI_LYNXEM
1761 Enable Silicon Motion SMI 712/710/810 Video chip. The
1762 video output is selected via environment 'videoout'
1763 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1766 For the CT69000 and SMI_LYNXEM drivers, videomode is
1767 selected via environment 'videomode'. Two different ways
1769 - "videomode=num" 'num' is a standard LiLo mode numbers.
1770 Following standard modes are supported (* is default):
1772 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1773 -------------+---------------------------------------------
1774 8 bits | 0x301* 0x303 0x305 0x161 0x307
1775 15 bits | 0x310 0x313 0x316 0x162 0x319
1776 16 bits | 0x311 0x314 0x317 0x163 0x31A
1777 24 bits | 0x312 0x315 0x318 ? 0x31B
1778 -------------+---------------------------------------------
1779 (i.e. setenv videomode 317; saveenv; reset;)
1781 - "videomode=bootargs" all the video parameters are parsed
1782 from the bootargs. (See drivers/video/videomodes.c)
1785 CONFIG_VIDEO_SED13806
1786 Enable Epson SED13806 driver. This driver supports 8bpp
1787 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1788 or CONFIG_VIDEO_SED13806_16BPP
1791 Enable the Freescale DIU video driver. Reference boards for
1792 SOCs that have a DIU should define this macro to enable DIU
1793 support, and should also define these other macros:
1799 CONFIG_VIDEO_SW_CURSOR
1800 CONFIG_VGA_AS_SINGLE_DEVICE
1802 CONFIG_VIDEO_BMP_LOGO
1804 The DIU driver will look for the 'video-mode' environment
1805 variable, and if defined, enable the DIU as a console during
1806 boot. See the documentation file doc/README.video for a
1807 description of this variable.
1809 - LCD Support: CONFIG_LCD
1811 Define this to enable LCD support (for output to LCD
1812 display); also select one of the supported displays
1813 by defining one of these:
1817 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1819 CONFIG_NEC_NL6448AC33:
1821 NEC NL6448AC33-18. Active, color, single scan.
1823 CONFIG_NEC_NL6448BC20
1825 NEC NL6448BC20-08. 6.5", 640x480.
1826 Active, color, single scan.
1828 CONFIG_NEC_NL6448BC33_54
1830 NEC NL6448BC33-54. 10.4", 640x480.
1831 Active, color, single scan.
1835 Sharp 320x240. Active, color, single scan.
1836 It isn't 16x9, and I am not sure what it is.
1838 CONFIG_SHARP_LQ64D341
1840 Sharp LQ64D341 display, 640x480.
1841 Active, color, single scan.
1845 HLD1045 display, 640x480.
1846 Active, color, single scan.
1850 Optrex CBL50840-2 NF-FW 99 22 M5
1852 Hitachi LMG6912RPFC-00T
1856 320x240. Black & white.
1858 Normally display is black on white background; define
1859 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1861 CONFIG_LCD_ALIGNMENT
1863 Normally the LCD is page-aligned (typically 4KB). If this is
1864 defined then the LCD will be aligned to this value instead.
1865 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1866 here, since it is cheaper to change data cache settings on
1867 a per-section basis.
1869 CONFIG_CONSOLE_SCROLL_LINES
1871 When the console need to be scrolled, this is the number of
1872 lines to scroll by. It defaults to 1. Increasing this makes
1873 the console jump but can help speed up operation when scrolling
1878 Sometimes, for example if the display is mounted in portrait
1879 mode or even if it's mounted landscape but rotated by 180degree,
1880 we need to rotate our content of the display relative to the
1881 framebuffer, so that user can read the messages which are
1883 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1884 initialized with a given rotation from "vl_rot" out of
1885 "vidinfo_t" which is provided by the board specific code.
1886 The value for vl_rot is coded as following (matching to
1887 fbcon=rotate:<n> linux-kernel commandline):
1888 0 = no rotation respectively 0 degree
1889 1 = 90 degree rotation
1890 2 = 180 degree rotation
1891 3 = 270 degree rotation
1893 If CONFIG_LCD_ROTATION is not defined, the console will be
1894 initialized with 0degree rotation.
1898 Support drawing of RLE8-compressed bitmaps on the LCD.
1902 Enables an 'i2c edid' command which can read EDID
1903 information over I2C from an attached LCD display.
1905 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1907 If this option is set, the environment is checked for
1908 a variable "splashimage". If found, the usual display
1909 of logo, copyright and system information on the LCD
1910 is suppressed and the BMP image at the address
1911 specified in "splashimage" is loaded instead. The
1912 console is redirected to the "nulldev", too. This
1913 allows for a "silent" boot where a splash screen is
1914 loaded very quickly after power-on.
1916 CONFIG_SPLASHIMAGE_GUARD
1918 If this option is set, then U-Boot will prevent the environment
1919 variable "splashimage" from being set to a problematic address
1920 (see doc/README.displaying-bmps).
1921 This option is useful for targets where, due to alignment
1922 restrictions, an improperly aligned BMP image will cause a data
1923 abort. If you think you will not have problems with unaligned
1924 accesses (for example because your toolchain prevents them)
1925 there is no need to set this option.
1927 CONFIG_SPLASH_SCREEN_ALIGN
1929 If this option is set the splash image can be freely positioned
1930 on the screen. Environment variable "splashpos" specifies the
1931 position as "x,y". If a positive number is given it is used as
1932 number of pixel from left/top. If a negative number is given it
1933 is used as number of pixel from right/bottom. You can also
1934 specify 'm' for centering the image.
1937 setenv splashpos m,m
1938 => image at center of screen
1940 setenv splashpos 30,20
1941 => image at x = 30 and y = 20
1943 setenv splashpos -10,m
1944 => vertically centered image
1945 at x = dspWidth - bmpWidth - 9
1947 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1949 If this option is set, additionally to standard BMP
1950 images, gzipped BMP images can be displayed via the
1951 splashscreen support or the bmp command.
1953 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1955 If this option is set, 8-bit RLE compressed BMP images
1956 can be displayed via the splashscreen support or the
1959 - Do compressing for memory range:
1962 If this option is set, it would use zlib deflate method
1963 to compress the specified memory at its best effort.
1965 - Compression support:
1968 Enabled by default to support gzip compressed images.
1972 If this option is set, support for bzip2 compressed
1973 images is included. If not, only uncompressed and gzip
1974 compressed images are supported.
1976 NOTE: the bzip2 algorithm requires a lot of RAM, so
1977 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1982 If this option is set, support for lzma compressed
1985 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1986 requires an amount of dynamic memory that is given by the
1989 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1991 Where lc and lp stand for, respectively, Literal context bits
1992 and Literal pos bits.
1994 This value is upper-bounded by 14MB in the worst case. Anyway,
1995 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1996 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1997 a very small buffer.
1999 Use the lzmainfo tool to determinate the lc and lp values and
2000 then calculate the amount of needed dynamic memory (ensuring
2001 the appropriate CONFIG_SYS_MALLOC_LEN value).
2005 If this option is set, support for LZO compressed images
2011 The address of PHY on MII bus.
2013 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2015 The clock frequency of the MII bus
2019 If this option is set, support for speed/duplex
2020 detection of gigabit PHY is included.
2022 CONFIG_PHY_RESET_DELAY
2024 Some PHY like Intel LXT971A need extra delay after
2025 reset before any MII register access is possible.
2026 For such PHY, set this option to the usec delay
2027 required. (minimum 300usec for LXT971A)
2029 CONFIG_PHY_CMD_DELAY (ppc4xx)
2031 Some PHY like Intel LXT971A need extra delay after
2032 command issued before MII status register can be read
2037 Define a default value for the IP address to use for
2038 the default Ethernet interface, in case this is not
2039 determined through e.g. bootp.
2040 (Environment variable "ipaddr")
2042 - Server IP address:
2045 Defines a default value for the IP address of a TFTP
2046 server to contact when using the "tftboot" command.
2047 (Environment variable "serverip")
2049 CONFIG_KEEP_SERVERADDR
2051 Keeps the server's MAC address, in the env 'serveraddr'
2052 for passing to bootargs (like Linux's netconsole option)
2054 - Gateway IP address:
2057 Defines a default value for the IP address of the
2058 default router where packets to other networks are
2060 (Environment variable "gatewayip")
2065 Defines a default value for the subnet mask (or
2066 routing prefix) which is used to determine if an IP
2067 address belongs to the local subnet or needs to be
2068 forwarded through a router.
2069 (Environment variable "netmask")
2071 - Multicast TFTP Mode:
2074 Defines whether you want to support multicast TFTP as per
2075 rfc-2090; for example to work with atftp. Lets lots of targets
2076 tftp down the same boot image concurrently. Note: the Ethernet
2077 driver in use must provide a function: mcast() to join/leave a
2080 - BOOTP Recovery Mode:
2081 CONFIG_BOOTP_RANDOM_DELAY
2083 If you have many targets in a network that try to
2084 boot using BOOTP, you may want to avoid that all
2085 systems send out BOOTP requests at precisely the same
2086 moment (which would happen for instance at recovery
2087 from a power failure, when all systems will try to
2088 boot, thus flooding the BOOTP server. Defining
2089 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2090 inserted before sending out BOOTP requests. The
2091 following delays are inserted then:
2093 1st BOOTP request: delay 0 ... 1 sec
2094 2nd BOOTP request: delay 0 ... 2 sec
2095 3rd BOOTP request: delay 0 ... 4 sec
2097 BOOTP requests: delay 0 ... 8 sec
2099 CONFIG_BOOTP_ID_CACHE_SIZE
2101 BOOTP packets are uniquely identified using a 32-bit ID. The
2102 server will copy the ID from client requests to responses and
2103 U-Boot will use this to determine if it is the destination of
2104 an incoming response. Some servers will check that addresses
2105 aren't in use before handing them out (usually using an ARP
2106 ping) and therefore take up to a few hundred milliseconds to
2107 respond. Network congestion may also influence the time it
2108 takes for a response to make it back to the client. If that
2109 time is too long, U-Boot will retransmit requests. In order
2110 to allow earlier responses to still be accepted after these
2111 retransmissions, U-Boot's BOOTP client keeps a small cache of
2112 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2113 cache. The default is to keep IDs for up to four outstanding
2114 requests. Increasing this will allow U-Boot to accept offers
2115 from a BOOTP client in networks with unusually high latency.
2117 - DHCP Advanced Options:
2118 You can fine tune the DHCP functionality by defining
2119 CONFIG_BOOTP_* symbols:
2121 CONFIG_BOOTP_SUBNETMASK
2122 CONFIG_BOOTP_GATEWAY
2123 CONFIG_BOOTP_HOSTNAME
2124 CONFIG_BOOTP_NISDOMAIN
2125 CONFIG_BOOTP_BOOTPATH
2126 CONFIG_BOOTP_BOOTFILESIZE
2129 CONFIG_BOOTP_SEND_HOSTNAME
2130 CONFIG_BOOTP_NTPSERVER
2131 CONFIG_BOOTP_TIMEOFFSET
2132 CONFIG_BOOTP_VENDOREX
2133 CONFIG_BOOTP_MAY_FAIL
2135 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2136 environment variable, not the BOOTP server.
2138 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2139 after the configured retry count, the call will fail
2140 instead of starting over. This can be used to fail over
2141 to Link-local IP address configuration if the DHCP server
2144 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2145 serverip from a DHCP server, it is possible that more
2146 than one DNS serverip is offered to the client.
2147 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2148 serverip will be stored in the additional environment
2149 variable "dnsip2". The first DNS serverip is always
2150 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2153 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2154 to do a dynamic update of a DNS server. To do this, they
2155 need the hostname of the DHCP requester.
2156 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2157 of the "hostname" environment variable is passed as
2158 option 12 to the DHCP server.
2160 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2162 A 32bit value in microseconds for a delay between
2163 receiving a "DHCP Offer" and sending the "DHCP Request".
2164 This fixes a problem with certain DHCP servers that don't
2165 respond 100% of the time to a "DHCP request". E.g. On an
2166 AT91RM9200 processor running at 180MHz, this delay needed
2167 to be *at least* 15,000 usec before a Windows Server 2003
2168 DHCP server would reply 100% of the time. I recommend at
2169 least 50,000 usec to be safe. The alternative is to hope
2170 that one of the retries will be successful but note that
2171 the DHCP timeout and retry process takes a longer than
2174 - Link-local IP address negotiation:
2175 Negotiate with other link-local clients on the local network
2176 for an address that doesn't require explicit configuration.
2177 This is especially useful if a DHCP server cannot be guaranteed
2178 to exist in all environments that the device must operate.
2180 See doc/README.link-local for more information.
2183 CONFIG_CDP_DEVICE_ID
2185 The device id used in CDP trigger frames.
2187 CONFIG_CDP_DEVICE_ID_PREFIX
2189 A two character string which is prefixed to the MAC address
2194 A printf format string which contains the ascii name of
2195 the port. Normally is set to "eth%d" which sets
2196 eth0 for the first Ethernet, eth1 for the second etc.
2198 CONFIG_CDP_CAPABILITIES
2200 A 32bit integer which indicates the device capabilities;
2201 0x00000010 for a normal host which does not forwards.
2205 An ascii string containing the version of the software.
2209 An ascii string containing the name of the platform.
2213 A 32bit integer sent on the trigger.
2215 CONFIG_CDP_POWER_CONSUMPTION
2217 A 16bit integer containing the power consumption of the
2218 device in .1 of milliwatts.
2220 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2222 A byte containing the id of the VLAN.
2224 - Status LED: CONFIG_STATUS_LED
2226 Several configurations allow to display the current
2227 status using a LED. For instance, the LED will blink
2228 fast while running U-Boot code, stop blinking as
2229 soon as a reply to a BOOTP request was received, and
2230 start blinking slow once the Linux kernel is running
2231 (supported by a status LED driver in the Linux
2232 kernel). Defining CONFIG_STATUS_LED enables this
2238 The status LED can be connected to a GPIO pin.
2239 In such cases, the gpio_led driver can be used as a
2240 status LED backend implementation. Define CONFIG_GPIO_LED
2241 to include the gpio_led driver in the U-Boot binary.
2243 CONFIG_GPIO_LED_INVERTED_TABLE
2244 Some GPIO connected LEDs may have inverted polarity in which
2245 case the GPIO high value corresponds to LED off state and
2246 GPIO low value corresponds to LED on state.
2247 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2248 with a list of GPIO LEDs that have inverted polarity.
2250 - CAN Support: CONFIG_CAN_DRIVER
2252 Defining CONFIG_CAN_DRIVER enables CAN driver support
2253 on those systems that support this (optional)
2254 feature, like the TQM8xxL modules.
2256 - I2C Support: CONFIG_SYS_I2C
2258 This enable the NEW i2c subsystem, and will allow you to use
2259 i2c commands at the u-boot command line (as long as you set
2260 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2261 based realtime clock chips or other i2c devices. See
2262 common/cmd_i2c.c for a description of the command line
2265 ported i2c driver to the new framework:
2266 - drivers/i2c/soft_i2c.c:
2267 - activate first bus with CONFIG_SYS_I2C_SOFT define
2268 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2269 for defining speed and slave address
2270 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2271 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2272 for defining speed and slave address
2273 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2274 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2275 for defining speed and slave address
2276 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2277 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2278 for defining speed and slave address
2280 - drivers/i2c/fsl_i2c.c:
2281 - activate i2c driver with CONFIG_SYS_I2C_FSL
2282 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2283 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2284 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2286 - If your board supports a second fsl i2c bus, define
2287 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2288 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2289 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2292 - drivers/i2c/tegra_i2c.c:
2293 - activate this driver with CONFIG_SYS_I2C_TEGRA
2294 - This driver adds 4 i2c buses with a fix speed from
2295 100000 and the slave addr 0!
2297 - drivers/i2c/ppc4xx_i2c.c
2298 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2299 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2300 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2302 - drivers/i2c/i2c_mxc.c
2303 - activate this driver with CONFIG_SYS_I2C_MXC
2304 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2305 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2306 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2307 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2308 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2309 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2310 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2311 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2312 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2313 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2314 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2315 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2316 If those defines are not set, default value is 100000
2317 for speed, and 0 for slave.
2319 - drivers/i2c/rcar_i2c.c:
2320 - activate this driver with CONFIG_SYS_I2C_RCAR
2321 - This driver adds 4 i2c buses
2323 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2324 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2325 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2326 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2327 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2328 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2329 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2330 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2331 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2333 - drivers/i2c/sh_i2c.c:
2334 - activate this driver with CONFIG_SYS_I2C_SH
2335 - This driver adds from 2 to 5 i2c buses
2337 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2338 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2339 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2340 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2341 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2342 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2343 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2344 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2345 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2346 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2347 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2348 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2349 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2351 - drivers/i2c/omap24xx_i2c.c
2352 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2353 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2354 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2355 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2356 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2357 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2358 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2359 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2360 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2361 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2362 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2364 - drivers/i2c/zynq_i2c.c
2365 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2366 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2367 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2369 - drivers/i2c/s3c24x0_i2c.c:
2370 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2371 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2372 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2373 with a fix speed from 100000 and the slave addr 0!
2375 - drivers/i2c/ihs_i2c.c
2376 - activate this driver with CONFIG_SYS_I2C_IHS
2377 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2378 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2379 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2380 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2381 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2382 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2383 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2384 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2385 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2386 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2387 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2388 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2389 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2390 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2391 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2392 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2393 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2394 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2395 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2396 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2397 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2401 CONFIG_SYS_NUM_I2C_BUSES
2402 Hold the number of i2c buses you want to use. If you
2403 don't use/have i2c muxes on your i2c bus, this
2404 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2407 CONFIG_SYS_I2C_DIRECT_BUS
2408 define this, if you don't use i2c muxes on your hardware.
2409 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2412 CONFIG_SYS_I2C_MAX_HOPS
2413 define how many muxes are maximal consecutively connected
2414 on one i2c bus. If you not use i2c muxes, omit this
2417 CONFIG_SYS_I2C_BUSES
2418 hold a list of buses you want to use, only used if
2419 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2420 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2421 CONFIG_SYS_NUM_I2C_BUSES = 9:
2423 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2424 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2425 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2426 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2427 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2428 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2429 {1, {I2C_NULL_HOP}}, \
2430 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2431 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2435 bus 0 on adapter 0 without a mux
2436 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2437 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2438 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2439 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2440 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2441 bus 6 on adapter 1 without a mux
2442 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2443 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2445 If you do not have i2c muxes on your board, omit this define.
2447 - Legacy I2C Support: CONFIG_HARD_I2C
2449 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2450 provides the following compelling advantages:
2452 - more than one i2c adapter is usable
2453 - approved multibus support
2454 - better i2c mux support
2456 ** Please consider updating your I2C driver now. **
2458 These enable legacy I2C serial bus commands. Defining
2459 CONFIG_HARD_I2C will include the appropriate I2C driver
2460 for the selected CPU.
2462 This will allow you to use i2c commands at the u-boot
2463 command line (as long as you set CONFIG_CMD_I2C in
2464 CONFIG_COMMANDS) and communicate with i2c based realtime
2465 clock chips. See common/cmd_i2c.c for a description of the
2466 command line interface.
2468 CONFIG_HARD_I2C selects a hardware I2C controller.
2470 There are several other quantities that must also be
2471 defined when you define CONFIG_HARD_I2C.
2473 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2474 to be the frequency (in Hz) at which you wish your i2c bus
2475 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2476 the CPU's i2c node address).
2478 Now, the u-boot i2c code for the mpc8xx
2479 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2480 and so its address should therefore be cleared to 0 (See,
2481 eg, MPC823e User's Manual p.16-473). So, set
2482 CONFIG_SYS_I2C_SLAVE to 0.
2484 CONFIG_SYS_I2C_INIT_MPC5XXX
2486 When a board is reset during an i2c bus transfer
2487 chips might think that the current transfer is still
2488 in progress. Reset the slave devices by sending start
2489 commands until the slave device responds.
2491 That's all that's required for CONFIG_HARD_I2C.
2493 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2494 then the following macros need to be defined (examples are
2495 from include/configs/lwmon.h):
2499 (Optional). Any commands necessary to enable the I2C
2500 controller or configure ports.
2502 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2506 (Only for MPC8260 CPU). The I/O port to use (the code
2507 assumes both bits are on the same port). Valid values
2508 are 0..3 for ports A..D.
2512 The code necessary to make the I2C data line active
2513 (driven). If the data line is open collector, this
2516 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2520 The code necessary to make the I2C data line tri-stated
2521 (inactive). If the data line is open collector, this
2524 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2528 Code that returns true if the I2C data line is high,
2531 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2535 If <bit> is true, sets the I2C data line high. If it
2536 is false, it clears it (low).
2538 eg: #define I2C_SDA(bit) \
2539 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2540 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2544 If <bit> is true, sets the I2C clock line high. If it
2545 is false, it clears it (low).
2547 eg: #define I2C_SCL(bit) \
2548 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2549 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2553 This delay is invoked four times per clock cycle so this
2554 controls the rate of data transfer. The data rate thus
2555 is 1 / (I2C_DELAY * 4). Often defined to be something
2558 #define I2C_DELAY udelay(2)
2560 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2562 If your arch supports the generic GPIO framework (asm/gpio.h),
2563 then you may alternatively define the two GPIOs that are to be
2564 used as SCL / SDA. Any of the previous I2C_xxx macros will
2565 have GPIO-based defaults assigned to them as appropriate.
2567 You should define these to the GPIO value as given directly to
2568 the generic GPIO functions.
2570 CONFIG_SYS_I2C_INIT_BOARD
2572 When a board is reset during an i2c bus transfer
2573 chips might think that the current transfer is still
2574 in progress. On some boards it is possible to access
2575 the i2c SCLK line directly, either by using the
2576 processor pin as a GPIO or by having a second pin
2577 connected to the bus. If this option is defined a
2578 custom i2c_init_board() routine in boards/xxx/board.c
2579 is run early in the boot sequence.
2581 CONFIG_SYS_I2C_BOARD_LATE_INIT
2583 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2584 defined a custom i2c_board_late_init() routine in
2585 boards/xxx/board.c is run AFTER the operations in i2c_init()
2586 is completed. This callpoint can be used to unreset i2c bus
2587 using CPU i2c controller register accesses for CPUs whose i2c
2588 controller provide such a method. It is called at the end of
2589 i2c_init() to allow i2c_init operations to setup the i2c bus
2590 controller on the CPU (e.g. setting bus speed & slave address).
2592 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2594 This option enables configuration of bi_iic_fast[] flags
2595 in u-boot bd_info structure based on u-boot environment
2596 variable "i2cfast". (see also i2cfast)
2598 CONFIG_I2C_MULTI_BUS
2600 This option allows the use of multiple I2C buses, each of which
2601 must have a controller. At any point in time, only one bus is
2602 active. To switch to a different bus, use the 'i2c dev' command.
2603 Note that bus numbering is zero-based.
2605 CONFIG_SYS_I2C_NOPROBES
2607 This option specifies a list of I2C devices that will be skipped
2608 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2609 is set, specify a list of bus-device pairs. Otherwise, specify
2610 a 1D array of device addresses
2613 #undef CONFIG_I2C_MULTI_BUS
2614 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2616 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2618 #define CONFIG_I2C_MULTI_BUS
2619 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2621 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2623 CONFIG_SYS_SPD_BUS_NUM
2625 If defined, then this indicates the I2C bus number for DDR SPD.
2626 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2628 CONFIG_SYS_RTC_BUS_NUM
2630 If defined, then this indicates the I2C bus number for the RTC.
2631 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2633 CONFIG_SYS_DTT_BUS_NUM
2635 If defined, then this indicates the I2C bus number for the DTT.
2636 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2638 CONFIG_SYS_I2C_DTT_ADDR:
2640 If defined, specifies the I2C address of the DTT device.
2641 If not defined, then U-Boot uses predefined value for
2642 specified DTT device.
2644 CONFIG_SOFT_I2C_READ_REPEATED_START
2646 defining this will force the i2c_read() function in
2647 the soft_i2c driver to perform an I2C repeated start
2648 between writing the address pointer and reading the
2649 data. If this define is omitted the default behaviour
2650 of doing a stop-start sequence will be used. Most I2C
2651 devices can use either method, but some require one or
2654 - SPI Support: CONFIG_SPI
2656 Enables SPI driver (so far only tested with
2657 SPI EEPROM, also an instance works with Crystal A/D and
2658 D/As on the SACSng board)
2662 Enables the driver for SPI controller on SuperH. Currently
2663 only SH7757 is supported.
2667 Enables a software (bit-bang) SPI driver rather than
2668 using hardware support. This is a general purpose
2669 driver that only requires three general I/O port pins
2670 (two outputs, one input) to function. If this is
2671 defined, the board configuration must define several
2672 SPI configuration items (port pins to use, etc). For
2673 an example, see include/configs/sacsng.h.
2677 Enables a hardware SPI driver for general-purpose reads
2678 and writes. As with CONFIG_SOFT_SPI, the board configuration
2679 must define a list of chip-select function pointers.
2680 Currently supported on some MPC8xxx processors. For an
2681 example, see include/configs/mpc8349emds.h.
2685 Enables the driver for the SPI controllers on i.MX and MXC
2686 SoCs. Currently i.MX31/35/51 are supported.
2688 CONFIG_SYS_SPI_MXC_WAIT
2689 Timeout for waiting until spi transfer completed.
2690 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2692 - FPGA Support: CONFIG_FPGA
2694 Enables FPGA subsystem.
2696 CONFIG_FPGA_<vendor>
2698 Enables support for specific chip vendors.
2701 CONFIG_FPGA_<family>
2703 Enables support for FPGA family.
2704 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2708 Specify the number of FPGA devices to support.
2710 CONFIG_CMD_FPGA_LOADMK
2712 Enable support for fpga loadmk command
2714 CONFIG_CMD_FPGA_LOADP
2716 Enable support for fpga loadp command - load partial bitstream
2718 CONFIG_CMD_FPGA_LOADBP
2720 Enable support for fpga loadbp command - load partial bitstream
2723 CONFIG_SYS_FPGA_PROG_FEEDBACK
2725 Enable printing of hash marks during FPGA configuration.
2727 CONFIG_SYS_FPGA_CHECK_BUSY
2729 Enable checks on FPGA configuration interface busy
2730 status by the configuration function. This option
2731 will require a board or device specific function to
2736 If defined, a function that provides delays in the FPGA
2737 configuration driver.
2739 CONFIG_SYS_FPGA_CHECK_CTRLC
2740 Allow Control-C to interrupt FPGA configuration
2742 CONFIG_SYS_FPGA_CHECK_ERROR
2744 Check for configuration errors during FPGA bitfile
2745 loading. For example, abort during Virtex II
2746 configuration if the INIT_B line goes low (which
2747 indicated a CRC error).
2749 CONFIG_SYS_FPGA_WAIT_INIT
2751 Maximum time to wait for the INIT_B line to de-assert
2752 after PROB_B has been de-asserted during a Virtex II
2753 FPGA configuration sequence. The default time is 500
2756 CONFIG_SYS_FPGA_WAIT_BUSY
2758 Maximum time to wait for BUSY to de-assert during
2759 Virtex II FPGA configuration. The default is 5 ms.
2761 CONFIG_SYS_FPGA_WAIT_CONFIG
2763 Time to wait after FPGA configuration. The default is
2766 - Configuration Management:
2769 Some SoCs need special image types (e.g. U-Boot binary
2770 with a special header) as build targets. By defining
2771 CONFIG_BUILD_TARGET in the SoC / board header, this
2772 special image will be automatically built upon calling
2777 If defined, this string will be added to the U-Boot
2778 version information (U_BOOT_VERSION)
2780 - Vendor Parameter Protection:
2782 U-Boot considers the values of the environment
2783 variables "serial#" (Board Serial Number) and
2784 "ethaddr" (Ethernet Address) to be parameters that
2785 are set once by the board vendor / manufacturer, and
2786 protects these variables from casual modification by
2787 the user. Once set, these variables are read-only,
2788 and write or delete attempts are rejected. You can
2789 change this behaviour:
2791 If CONFIG_ENV_OVERWRITE is #defined in your config
2792 file, the write protection for vendor parameters is
2793 completely disabled. Anybody can change or delete
2796 Alternatively, if you define _both_ an ethaddr in the
2797 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2798 Ethernet address is installed in the environment,
2799 which can be changed exactly ONCE by the user. [The
2800 serial# is unaffected by this, i. e. it remains
2803 The same can be accomplished in a more flexible way
2804 for any variable by configuring the type of access
2805 to allow for those variables in the ".flags" variable
2806 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2811 Define this variable to enable the reservation of
2812 "protected RAM", i. e. RAM which is not overwritten
2813 by U-Boot. Define CONFIG_PRAM to hold the number of
2814 kB you want to reserve for pRAM. You can overwrite
2815 this default value by defining an environment
2816 variable "pram" to the number of kB you want to
2817 reserve. Note that the board info structure will
2818 still show the full amount of RAM. If pRAM is
2819 reserved, a new environment variable "mem" will
2820 automatically be defined to hold the amount of
2821 remaining RAM in a form that can be passed as boot
2822 argument to Linux, for instance like that:
2824 setenv bootargs ... mem=\${mem}
2827 This way you can tell Linux not to use this memory,
2828 either, which results in a memory region that will
2829 not be affected by reboots.
2831 *WARNING* If your board configuration uses automatic
2832 detection of the RAM size, you must make sure that
2833 this memory test is non-destructive. So far, the
2834 following board configurations are known to be
2837 IVMS8, IVML24, SPD8xx, TQM8xxL,
2838 HERMES, IP860, RPXlite, LWMON,
2841 - Access to physical memory region (> 4GB)
2842 Some basic support is provided for operations on memory not
2843 normally accessible to U-Boot - e.g. some architectures
2844 support access to more than 4GB of memory on 32-bit
2845 machines using physical address extension or similar.
2846 Define CONFIG_PHYSMEM to access this basic support, which
2847 currently only supports clearing the memory.
2852 Define this variable to stop the system in case of a
2853 fatal error, so that you have to reset it manually.
2854 This is probably NOT a good idea for an embedded
2855 system where you want the system to reboot
2856 automatically as fast as possible, but it may be
2857 useful during development since you can try to debug
2858 the conditions that lead to the situation.
2860 CONFIG_NET_RETRY_COUNT
2862 This variable defines the number of retries for
2863 network operations like ARP, RARP, TFTP, or BOOTP
2864 before giving up the operation. If not defined, a
2865 default value of 5 is used.
2869 Timeout waiting for an ARP reply in milliseconds.
2873 Timeout in milliseconds used in NFS protocol.
2874 If you encounter "ERROR: Cannot umount" in nfs command,
2875 try longer timeout such as
2876 #define CONFIG_NFS_TIMEOUT 10000UL
2878 - Command Interpreter:
2879 CONFIG_AUTO_COMPLETE
2881 Enable auto completion of commands using TAB.
2883 CONFIG_SYS_PROMPT_HUSH_PS2
2885 This defines the secondary prompt string, which is
2886 printed when the command interpreter needs more input
2887 to complete a command. Usually "> ".
2891 In the current implementation, the local variables
2892 space and global environment variables space are
2893 separated. Local variables are those you define by
2894 simply typing `name=value'. To access a local
2895 variable later on, you have write `$name' or
2896 `${name}'; to execute the contents of a variable
2897 directly type `$name' at the command prompt.
2899 Global environment variables are those you use
2900 setenv/printenv to work with. To run a command stored
2901 in such a variable, you need to use the run command,
2902 and you must not use the '$' sign to access them.
2904 To store commands and special characters in a
2905 variable, please use double quotation marks
2906 surrounding the whole text of the variable, instead
2907 of the backslashes before semicolons and special
2910 - Command Line Editing and History:
2911 CONFIG_CMDLINE_EDITING
2913 Enable editing and History functions for interactive
2914 command line input operations
2916 - Command Line PS1/PS2 support:
2917 CONFIG_CMDLINE_PS_SUPPORT
2919 Enable support for changing the command prompt string
2920 at run-time. Only static string is supported so far.
2921 The string is obtained from environment variables PS1
2924 - Default Environment:
2925 CONFIG_EXTRA_ENV_SETTINGS
2927 Define this to contain any number of null terminated
2928 strings (variable = value pairs) that will be part of
2929 the default environment compiled into the boot image.
2931 For example, place something like this in your
2932 board's config file:
2934 #define CONFIG_EXTRA_ENV_SETTINGS \
2938 Warning: This method is based on knowledge about the
2939 internal format how the environment is stored by the
2940 U-Boot code. This is NOT an official, exported
2941 interface! Although it is unlikely that this format
2942 will change soon, there is no guarantee either.
2943 You better know what you are doing here.
2945 Note: overly (ab)use of the default environment is
2946 discouraged. Make sure to check other ways to preset
2947 the environment like the "source" command or the
2950 CONFIG_ENV_VARS_UBOOT_CONFIG
2952 Define this in order to add variables describing the
2953 U-Boot build configuration to the default environment.
2954 These will be named arch, cpu, board, vendor, and soc.
2956 Enabling this option will cause the following to be defined:
2964 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2966 Define this in order to add variables describing certain
2967 run-time determined information about the hardware to the
2968 environment. These will be named board_name, board_rev.
2970 CONFIG_DELAY_ENVIRONMENT
2972 Normally the environment is loaded when the board is
2973 initialised so that it is available to U-Boot. This inhibits
2974 that so that the environment is not available until
2975 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2976 this is instead controlled by the value of
2977 /config/load-environment.
2979 - Parallel Flash support:
2982 Traditionally U-Boot was run on systems with parallel NOR
2983 flash. This option is used to disable support for parallel NOR
2984 flash. This option should be defined if the board does not have
2987 If this option is not defined one of the generic flash drivers
2988 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2989 selected or the board must provide an implementation of the
2990 flash API (see include/flash.h).
2992 - DataFlash Support:
2993 CONFIG_HAS_DATAFLASH
2995 Defining this option enables DataFlash features and
2996 allows to read/write in Dataflash via the standard
2999 - Serial Flash support
3002 Defining this option enables SPI flash commands
3003 'sf probe/read/write/erase/update'.
3005 Usage requires an initial 'probe' to define the serial
3006 flash parameters, followed by read/write/erase/update
3009 The following defaults may be provided by the platform
3010 to handle the common case when only a single serial
3011 flash is present on the system.
3013 CONFIG_SF_DEFAULT_BUS Bus identifier
3014 CONFIG_SF_DEFAULT_CS Chip-select
3015 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3016 CONFIG_SF_DEFAULT_SPEED in Hz
3020 Define this option to include a destructive SPI flash
3023 CONFIG_SF_DUAL_FLASH Dual flash memories
3025 Define this option to use dual flash support where two flash
3026 memories can be connected with a given cs line.
3027 Currently Xilinx Zynq qspi supports these type of connections.
3029 - SystemACE Support:
3032 Adding this option adds support for Xilinx SystemACE
3033 chips attached via some sort of local bus. The address
3034 of the chip must also be defined in the
3035 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3037 #define CONFIG_SYSTEMACE
3038 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3040 When SystemACE support is added, the "ace" device type
3041 becomes available to the fat commands, i.e. fatls.
3043 - TFTP Fixed UDP Port:
3046 If this is defined, the environment variable tftpsrcp
3047 is used to supply the TFTP UDP source port value.
3048 If tftpsrcp isn't defined, the normal pseudo-random port
3049 number generator is used.
3051 Also, the environment variable tftpdstp is used to supply
3052 the TFTP UDP destination port value. If tftpdstp isn't
3053 defined, the normal port 69 is used.
3055 The purpose for tftpsrcp is to allow a TFTP server to
3056 blindly start the TFTP transfer using the pre-configured
3057 target IP address and UDP port. This has the effect of
3058 "punching through" the (Windows XP) firewall, allowing
3059 the remainder of the TFTP transfer to proceed normally.
3060 A better solution is to properly configure the firewall,
3061 but sometimes that is not allowed.
3066 This enables a generic 'hash' command which can produce
3067 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3071 Enable the hash verify command (hash -v). This adds to code
3074 CONFIG_SHA1 - This option enables support of hashing using SHA1
3075 algorithm. The hash is calculated in software.
3076 CONFIG_SHA256 - This option enables support of hashing using
3077 SHA256 algorithm. The hash is calculated in software.
3078 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3079 for SHA1/SHA256 hashing.
3080 This affects the 'hash' command and also the
3081 hash_lookup_algo() function.
3082 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3083 hardware-acceleration for SHA1/SHA256 progressive hashing.
3084 Data can be streamed in a block at a time and the hashing
3085 is performed in hardware.
3087 Note: There is also a sha1sum command, which should perhaps
3088 be deprecated in favour of 'hash sha1'.
3090 - Freescale i.MX specific commands:
3091 CONFIG_CMD_HDMIDETECT
3092 This enables 'hdmidet' command which returns true if an
3093 HDMI monitor is detected. This command is i.MX 6 specific.
3096 This enables the 'bmode' (bootmode) command for forcing
3097 a boot from specific media.
3099 This is useful for forcing the ROM's usb downloader to
3100 activate upon a watchdog reset which is nice when iterating
3101 on U-Boot. Using the reset button or running bmode normal
3102 will set it back to normal. This command currently
3103 supports i.MX53 and i.MX6.
3105 - bootcount support:
3106 CONFIG_BOOTCOUNT_LIMIT
3108 This enables the bootcounter support, see:
3109 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3112 enable special bootcounter support on at91sam9xe based boards.
3114 enable special bootcounter support on blackfin based boards.
3116 enable special bootcounter support on da850 based boards.
3117 CONFIG_BOOTCOUNT_RAM
3118 enable support for the bootcounter in RAM
3119 CONFIG_BOOTCOUNT_I2C
3120 enable support for the bootcounter on an i2c (like RTC) device.
3121 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3122 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3124 CONFIG_BOOTCOUNT_ALEN = address len
3126 - Show boot progress:
3127 CONFIG_SHOW_BOOT_PROGRESS
3129 Defining this option allows to add some board-
3130 specific code (calling a user-provided function
3131 "show_boot_progress(int)") that enables you to show
3132 the system's boot progress on some display (for
3133 example, some LED's) on your board. At the moment,
3134 the following checkpoints are implemented:
3137 Legacy uImage format:
3140 1 common/cmd_bootm.c before attempting to boot an image
3141 -1 common/cmd_bootm.c Image header has bad magic number
3142 2 common/cmd_bootm.c Image header has correct magic number
3143 -2 common/cmd_bootm.c Image header has bad checksum
3144 3 common/cmd_bootm.c Image header has correct checksum
3145 -3 common/cmd_bootm.c Image data has bad checksum
3146 4 common/cmd_bootm.c Image data has correct checksum
3147 -4 common/cmd_bootm.c Image is for unsupported architecture
3148 5 common/cmd_bootm.c Architecture check OK
3149 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3150 6 common/cmd_bootm.c Image Type check OK
3151 -6 common/cmd_bootm.c gunzip uncompression error
3152 -7 common/cmd_bootm.c Unimplemented compression type
3153 7 common/cmd_bootm.c Uncompression OK
3154 8 common/cmd_bootm.c No uncompress/copy overwrite error
3155 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3157 9 common/image.c Start initial ramdisk verification
3158 -10 common/image.c Ramdisk header has bad magic number
3159 -11 common/image.c Ramdisk header has bad checksum
3160 10 common/image.c Ramdisk header is OK
3161 -12 common/image.c Ramdisk data has bad checksum
3162 11 common/image.c Ramdisk data has correct checksum
3163 12 common/image.c Ramdisk verification complete, start loading
3164 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3165 13 common/image.c Start multifile image verification
3166 14 common/image.c No initial ramdisk, no multifile, continue.
3168 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3170 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3171 -31 post/post.c POST test failed, detected by post_output_backlog()
3172 -32 post/post.c POST test failed, detected by post_run_single()
3174 34 common/cmd_doc.c before loading a Image from a DOC device
3175 -35 common/cmd_doc.c Bad usage of "doc" command
3176 35 common/cmd_doc.c correct usage of "doc" command
3177 -36 common/cmd_doc.c No boot device
3178 36 common/cmd_doc.c correct boot device
3179 -37 common/cmd_doc.c Unknown Chip ID on boot device
3180 37 common/cmd_doc.c correct chip ID found, device available
3181 -38 common/cmd_doc.c Read Error on boot device
3182 38 common/cmd_doc.c reading Image header from DOC device OK
3183 -39 common/cmd_doc.c Image header has bad magic number
3184 39 common/cmd_doc.c Image header has correct magic number
3185 -40 common/cmd_doc.c Error reading Image from DOC device
3186 40 common/cmd_doc.c Image header has correct magic number
3187 41 common/cmd_ide.c before loading a Image from a IDE device
3188 -42 common/cmd_ide.c Bad usage of "ide" command
3189 42 common/cmd_ide.c correct usage of "ide" command
3190 -43 common/cmd_ide.c No boot device
3191 43 common/cmd_ide.c boot device found
3192 -44 common/cmd_ide.c Device not available
3193 44 common/cmd_ide.c Device available
3194 -45 common/cmd_ide.c wrong partition selected
3195 45 common/cmd_ide.c partition selected
3196 -46 common/cmd_ide.c Unknown partition table
3197 46 common/cmd_ide.c valid partition table found
3198 -47 common/cmd_ide.c Invalid partition type
3199 47 common/cmd_ide.c correct partition type
3200 -48 common/cmd_ide.c Error reading Image Header on boot device
3201 48 common/cmd_ide.c reading Image Header from IDE device OK
3202 -49 common/cmd_ide.c Image header has bad magic number
3203 49 common/cmd_ide.c Image header has correct magic number
3204 -50 common/cmd_ide.c Image header has bad checksum
3205 50 common/cmd_ide.c Image header has correct checksum
3206 -51 common/cmd_ide.c Error reading Image from IDE device
3207 51 common/cmd_ide.c reading Image from IDE device OK
3208 52 common/cmd_nand.c before loading a Image from a NAND device
3209 -53 common/cmd_nand.c Bad usage of "nand" command
3210 53 common/cmd_nand.c correct usage of "nand" command
3211 -54 common/cmd_nand.c No boot device
3212 54 common/cmd_nand.c boot device found
3213 -55 common/cmd_nand.c Unknown Chip ID on boot device
3214 55 common/cmd_nand.c correct chip ID found, device available
3215 -56 common/cmd_nand.c Error reading Image Header on boot device
3216 56 common/cmd_nand.c reading Image Header from NAND device OK
3217 -57 common/cmd_nand.c Image header has bad magic number
3218 57 common/cmd_nand.c Image header has correct magic number
3219 -58 common/cmd_nand.c Error reading Image from NAND device
3220 58 common/cmd_nand.c reading Image from NAND device OK
3222 -60 common/env_common.c Environment has a bad CRC, using default
3224 64 net/eth.c starting with Ethernet configuration.
3225 -64 net/eth.c no Ethernet found.
3226 65 net/eth.c Ethernet found.
3228 -80 common/cmd_net.c usage wrong
3229 80 common/cmd_net.c before calling net_loop()
3230 -81 common/cmd_net.c some error in net_loop() occurred
3231 81 common/cmd_net.c net_loop() back without error
3232 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3233 82 common/cmd_net.c trying automatic boot
3234 83 common/cmd_net.c running "source" command
3235 -83 common/cmd_net.c some error in automatic boot or "source" command
3236 84 common/cmd_net.c end without errors
3241 100 common/cmd_bootm.c Kernel FIT Image has correct format
3242 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3243 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3244 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3245 102 common/cmd_bootm.c Kernel unit name specified
3246 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3247 103 common/cmd_bootm.c Found configuration node
3248 104 common/cmd_bootm.c Got kernel subimage node offset
3249 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3250 105 common/cmd_bootm.c Kernel subimage hash verification OK
3251 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3252 106 common/cmd_bootm.c Architecture check OK
3253 -106 common/cmd_bootm.c Kernel subimage has wrong type
3254 107 common/cmd_bootm.c Kernel subimage type OK
3255 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3256 108 common/cmd_bootm.c Got kernel subimage data/size
3257 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3258 -109 common/cmd_bootm.c Can't get kernel subimage type
3259 -110 common/cmd_bootm.c Can't get kernel subimage comp
3260 -111 common/cmd_bootm.c Can't get kernel subimage os
3261 -112 common/cmd_bootm.c Can't get kernel subimage load address
3262 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3264 120 common/image.c Start initial ramdisk verification
3265 -120 common/image.c Ramdisk FIT image has incorrect format
3266 121 common/image.c Ramdisk FIT image has correct format
3267 122 common/image.c No ramdisk subimage unit name, using configuration
3268 -122 common/image.c Can't get configuration for ramdisk subimage
3269 123 common/image.c Ramdisk unit name specified
3270 -124 common/image.c Can't get ramdisk subimage node offset
3271 125 common/image.c Got ramdisk subimage node offset
3272 -125 common/image.c Ramdisk subimage hash verification failed
3273 126 common/image.c Ramdisk subimage hash verification OK
3274 -126 common/image.c Ramdisk subimage for unsupported architecture
3275 127 common/image.c Architecture check OK
3276 -127 common/image.c Can't get ramdisk subimage data/size
3277 128 common/image.c Got ramdisk subimage data/size
3278 129 common/image.c Can't get ramdisk load address
3279 -129 common/image.c Got ramdisk load address
3281 -130 common/cmd_doc.c Incorrect FIT image format
3282 131 common/cmd_doc.c FIT image format OK
3284 -140 common/cmd_ide.c Incorrect FIT image format
3285 141 common/cmd_ide.c FIT image format OK
3287 -150 common/cmd_nand.c Incorrect FIT image format
3288 151 common/cmd_nand.c FIT image format OK
3290 - legacy image format:
3291 CONFIG_IMAGE_FORMAT_LEGACY
3292 enables the legacy image format support in U-Boot.
3295 enabled if CONFIG_FIT_SIGNATURE is not defined.
3297 CONFIG_DISABLE_IMAGE_LEGACY
3298 disable the legacy image format
3300 This define is introduced, as the legacy image format is
3301 enabled per default for backward compatibility.
3303 - FIT image support:
3304 CONFIG_FIT_DISABLE_SHA256
3305 Supporting SHA256 hashes has quite an impact on binary size.
3306 For constrained systems sha256 hash support can be disabled
3309 TODO(sjg@chromium.org): Adjust this option to be positive,
3310 and move it to Kconfig
3312 - Standalone program support:
3313 CONFIG_STANDALONE_LOAD_ADDR
3315 This option defines a board specific value for the
3316 address where standalone program gets loaded, thus
3317 overwriting the architecture dependent default
3320 - Frame Buffer Address:
3323 Define CONFIG_FB_ADDR if you want to use specific
3324 address for frame buffer. This is typically the case
3325 when using a graphics controller has separate video
3326 memory. U-Boot will then place the frame buffer at
3327 the given address instead of dynamically reserving it
3328 in system RAM by calling lcd_setmem(), which grabs
3329 the memory for the frame buffer depending on the
3330 configured panel size.
3332 Please see board_init_f function.
3334 - Automatic software updates via TFTP server
3336 CONFIG_UPDATE_TFTP_CNT_MAX
3337 CONFIG_UPDATE_TFTP_MSEC_MAX
3339 These options enable and control the auto-update feature;
3340 for a more detailed description refer to doc/README.update.
3342 - MTD Support (mtdparts command, UBI support)
3345 Adds the MTD device infrastructure from the Linux kernel.
3346 Needed for mtdparts command support.
3348 CONFIG_MTD_PARTITIONS
3350 Adds the MTD partitioning infrastructure from the Linux
3351 kernel. Needed for UBI support.
3356 Adds commands for interacting with MTD partitions formatted
3357 with the UBI flash translation layer
3359 Requires also defining CONFIG_RBTREE
3361 CONFIG_UBI_SILENCE_MSG
3363 Make the verbose messages from UBI stop printing. This leaves
3364 warnings and errors enabled.
3367 CONFIG_MTD_UBI_WL_THRESHOLD
3368 This parameter defines the maximum difference between the highest
3369 erase counter value and the lowest erase counter value of eraseblocks
3370 of UBI devices. When this threshold is exceeded, UBI starts performing
3371 wear leveling by means of moving data from eraseblock with low erase
3372 counter to eraseblocks with high erase counter.
3374 The default value should be OK for SLC NAND flashes, NOR flashes and
3375 other flashes which have eraseblock life-cycle 100000 or more.
3376 However, in case of MLC NAND flashes which typically have eraseblock
3377 life-cycle less than 10000, the threshold should be lessened (e.g.,
3378 to 128 or 256, although it does not have to be power of 2).
3382 CONFIG_MTD_UBI_BEB_LIMIT
3383 This option specifies the maximum bad physical eraseblocks UBI
3384 expects on the MTD device (per 1024 eraseblocks). If the
3385 underlying flash does not admit of bad eraseblocks (e.g. NOR
3386 flash), this value is ignored.
3388 NAND datasheets often specify the minimum and maximum NVM
3389 (Number of Valid Blocks) for the flashes' endurance lifetime.
3390 The maximum expected bad eraseblocks per 1024 eraseblocks
3391 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3392 which gives 20 for most NANDs (MaxNVB is basically the total
3393 count of eraseblocks on the chip).
3395 To put it differently, if this value is 20, UBI will try to
3396 reserve about 1.9% of physical eraseblocks for bad blocks
3397 handling. And that will be 1.9% of eraseblocks on the entire
3398 NAND chip, not just the MTD partition UBI attaches. This means
3399 that if you have, say, a NAND flash chip admits maximum 40 bad
3400 eraseblocks, and it is split on two MTD partitions of the same
3401 size, UBI will reserve 40 eraseblocks when attaching a
3406 CONFIG_MTD_UBI_FASTMAP
3407 Fastmap is a mechanism which allows attaching an UBI device
3408 in nearly constant time. Instead of scanning the whole MTD device it
3409 only has to locate a checkpoint (called fastmap) on the device.
3410 The on-flash fastmap contains all information needed to attach
3411 the device. Using fastmap makes only sense on large devices where
3412 attaching by scanning takes long. UBI will not automatically install
3413 a fastmap on old images, but you can set the UBI parameter
3414 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3415 that fastmap-enabled images are still usable with UBI implementations
3416 without fastmap support. On typical flash devices the whole fastmap
3417 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3419 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3420 Set this parameter to enable fastmap automatically on images
3424 CONFIG_MTD_UBI_FM_DEBUG
3425 Enable UBI fastmap debug
3431 Adds commands for interacting with UBI volumes formatted as
3432 UBIFS. UBIFS is read-only in u-boot.
3434 Requires UBI support as well as CONFIG_LZO
3436 CONFIG_UBIFS_SILENCE_MSG
3438 Make the verbose messages from UBIFS stop printing. This leaves
3439 warnings and errors enabled.
3443 Enable building of SPL globally.
3446 LDSCRIPT for linking the SPL binary.
3448 CONFIG_SPL_MAX_FOOTPRINT
3449 Maximum size in memory allocated to the SPL, BSS included.
3450 When defined, the linker checks that the actual memory
3451 used by SPL from _start to __bss_end does not exceed it.
3452 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3453 must not be both defined at the same time.
3456 Maximum size of the SPL image (text, data, rodata, and
3457 linker lists sections), BSS excluded.
3458 When defined, the linker checks that the actual size does
3461 CONFIG_SPL_TEXT_BASE
3462 TEXT_BASE for linking the SPL binary.
3464 CONFIG_SPL_RELOC_TEXT_BASE
3465 Address to relocate to. If unspecified, this is equal to
3466 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3468 CONFIG_SPL_BSS_START_ADDR
3469 Link address for the BSS within the SPL binary.
3471 CONFIG_SPL_BSS_MAX_SIZE
3472 Maximum size in memory allocated to the SPL BSS.
3473 When defined, the linker checks that the actual memory used
3474 by SPL from __bss_start to __bss_end does not exceed it.
3475 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3476 must not be both defined at the same time.
3479 Adress of the start of the stack SPL will use
3481 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3482 When defined, SPL will panic() if the image it has
3483 loaded does not have a signature.
3484 Defining this is useful when code which loads images
3485 in SPL cannot guarantee that absolutely all read errors
3487 An example is the LPC32XX MLC NAND driver, which will
3488 consider that a completely unreadable NAND block is bad,
3489 and thus should be skipped silently.
3491 CONFIG_SPL_ABORT_ON_RAW_IMAGE
3492 When defined, SPL will proceed to another boot method
3493 if the image it has loaded does not have a signature.
3495 CONFIG_SPL_RELOC_STACK
3496 Adress of the start of the stack SPL will use after
3497 relocation. If unspecified, this is equal to
3500 CONFIG_SYS_SPL_MALLOC_START
3501 Starting address of the malloc pool used in SPL.
3502 When this option is set the full malloc is used in SPL and
3503 it is set up by spl_init() and before that, the simple malloc()
3504 can be used if CONFIG_SYS_MALLOC_F is defined.
3506 CONFIG_SYS_SPL_MALLOC_SIZE
3507 The size of the malloc pool used in SPL.
3509 CONFIG_SPL_FRAMEWORK
3510 Enable the SPL framework under common/. This framework
3511 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3512 NAND loading of the Linux Kernel.
3515 Enable booting directly to an OS from SPL.
3516 See also: doc/README.falcon
3518 CONFIG_SPL_DISPLAY_PRINT
3519 For ARM, enable an optional function to print more information
3520 about the running system.
3522 CONFIG_SPL_INIT_MINIMAL
3523 Arch init code should be built for a very small image
3525 CONFIG_SPL_LIBCOMMON_SUPPORT
3526 Support for common/libcommon.o in SPL binary
3528 CONFIG_SPL_LIBDISK_SUPPORT
3529 Support for disk/libdisk.o in SPL binary
3531 CONFIG_SPL_I2C_SUPPORT
3532 Support for drivers/i2c/libi2c.o in SPL binary
3534 CONFIG_SPL_GPIO_SUPPORT
3535 Support for drivers/gpio/libgpio.o in SPL binary
3537 CONFIG_SPL_MMC_SUPPORT
3538 Support for drivers/mmc/libmmc.o in SPL binary
3540 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3541 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3542 Address and partition on the MMC to load U-Boot from
3543 when the MMC is being used in raw mode.
3545 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3546 Partition on the MMC to load U-Boot from when the MMC is being
3549 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3550 Sector to load kernel uImage from when MMC is being
3551 used in raw mode (for Falcon mode)
3553 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3554 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3555 Sector and number of sectors to load kernel argument
3556 parameters from when MMC is being used in raw mode
3559 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3560 Partition on the MMC to load U-Boot from when the MMC is being
3563 CONFIG_SPL_FAT_SUPPORT
3564 Support for fs/fat/libfat.o in SPL binary
3566 CONFIG_SPL_EXT_SUPPORT
3567 Support for EXT filesystem in SPL binary
3569 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3570 Filename to read to load U-Boot when reading from filesystem
3572 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3573 Filename to read to load kernel uImage when reading
3574 from filesystem (for Falcon mode)
3576 CONFIG_SPL_FS_LOAD_ARGS_NAME
3577 Filename to read to load kernel argument parameters
3578 when reading from filesystem (for Falcon mode)
3580 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3581 Set this for NAND SPL on PPC mpc83xx targets, so that
3582 start.S waits for the rest of the SPL to load before
3583 continuing (the hardware starts execution after just
3584 loading the first page rather than the full 4K).
3586 CONFIG_SPL_SKIP_RELOCATE
3587 Avoid SPL relocation
3589 CONFIG_SPL_NAND_BASE
3590 Include nand_base.c in the SPL. Requires
3591 CONFIG_SPL_NAND_DRIVERS.
3593 CONFIG_SPL_NAND_DRIVERS
3594 SPL uses normal NAND drivers, not minimal drivers.
3597 Include standard software ECC in the SPL
3599 CONFIG_SPL_NAND_SIMPLE
3600 Support for NAND boot using simple NAND drivers that
3601 expose the cmd_ctrl() interface.
3603 CONFIG_SPL_MTD_SUPPORT
3604 Support for the MTD subsystem within SPL. Useful for
3605 environment on NAND support within SPL.
3607 CONFIG_SPL_NAND_RAW_ONLY
3608 Support to boot only raw u-boot.bin images. Use this only
3609 if you need to save space.
3611 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3612 Set for the SPL on PPC mpc8xxx targets, support for
3613 drivers/ddr/fsl/libddr.o in SPL binary.
3615 CONFIG_SPL_COMMON_INIT_DDR
3616 Set for common ddr init with serial presence detect in
3619 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3620 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3621 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3622 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3623 CONFIG_SYS_NAND_ECCBYTES
3624 Defines the size and behavior of the NAND that SPL uses
3627 CONFIG_SPL_NAND_BOOT
3628 Add support NAND boot
3630 CONFIG_SYS_NAND_U_BOOT_OFFS
3631 Location in NAND to read U-Boot from
3633 CONFIG_SYS_NAND_U_BOOT_DST
3634 Location in memory to load U-Boot to
3636 CONFIG_SYS_NAND_U_BOOT_SIZE
3637 Size of image to load
3639 CONFIG_SYS_NAND_U_BOOT_START
3640 Entry point in loaded image to jump to
3642 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3643 Define this if you need to first read the OOB and then the
3644 data. This is used, for example, on davinci platforms.
3646 CONFIG_SPL_OMAP3_ID_NAND
3647 Support for an OMAP3-specific set of functions to return the
3648 ID and MFR of the first attached NAND chip, if present.
3650 CONFIG_SPL_SERIAL_SUPPORT
3651 Support for drivers/serial/libserial.o in SPL binary
3653 CONFIG_SPL_SPI_FLASH_SUPPORT
3654 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3656 CONFIG_SPL_SPI_SUPPORT
3657 Support for drivers/spi/libspi.o in SPL binary
3659 CONFIG_SPL_RAM_DEVICE
3660 Support for running image already present in ram, in SPL binary
3662 CONFIG_SPL_LIBGENERIC_SUPPORT
3663 Support for lib/libgeneric.o in SPL binary
3665 CONFIG_SPL_ENV_SUPPORT
3666 Support for the environment operating in SPL binary
3668 CONFIG_SPL_NET_SUPPORT
3669 Support for the net/libnet.o in SPL binary.
3670 It conflicts with SPL env from storage medium specified by
3671 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3674 Image offset to which the SPL should be padded before appending
3675 the SPL payload. By default, this is defined as
3676 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3677 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3678 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3681 Final target image containing SPL and payload. Some SPLs
3682 use an arch-specific makefile fragment instead, for
3683 example if more than one image needs to be produced.
3685 CONFIG_FIT_SPL_PRINT
3686 Printing information about a FIT image adds quite a bit of
3687 code to SPL. So this is normally disabled in SPL. Use this
3688 option to re-enable it. This will affect the output of the
3689 bootm command when booting a FIT image.
3693 Enable building of TPL globally.
3696 Image offset to which the TPL should be padded before appending
3697 the TPL payload. By default, this is defined as
3698 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3699 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3700 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3702 - Interrupt support (PPC):
3704 There are common interrupt_init() and timer_interrupt()
3705 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3706 for CPU specific initialization. interrupt_init_cpu()
3707 should set decrementer_count to appropriate value. If
3708 CPU resets decrementer automatically after interrupt
3709 (ppc4xx) it should set decrementer_count to zero.
3710 timer_interrupt() calls timer_interrupt_cpu() for CPU
3711 specific handling. If board has watchdog / status_led
3712 / other_activity_monitor it works automatically from
3713 general timer_interrupt().
3716 Board initialization settings:
3717 ------------------------------
3719 During Initialization u-boot calls a number of board specific functions
3720 to allow the preparation of board specific prerequisites, e.g. pin setup
3721 before drivers are initialized. To enable these callbacks the
3722 following configuration macros have to be defined. Currently this is
3723 architecture specific, so please check arch/your_architecture/lib/board.c
3724 typically in board_init_f() and board_init_r().
3726 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3727 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3728 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3729 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3731 Configuration Settings:
3732 -----------------------
3734 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3735 Optionally it can be defined to support 64-bit memory commands.
3737 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3738 undefine this when you're short of memory.
3740 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3741 width of the commands listed in the 'help' command output.
3743 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3744 prompt for user input.
3746 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3748 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3750 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3752 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3753 the application (usually a Linux kernel) when it is
3756 - CONFIG_SYS_BAUDRATE_TABLE:
3757 List of legal baudrate settings for this board.
3759 - CONFIG_SYS_CONSOLE_INFO_QUIET
3760 Suppress display of console information at boot.
3762 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3763 If the board specific function
3764 extern int overwrite_console (void);
3765 returns 1, the stdin, stderr and stdout are switched to the
3766 serial port, else the settings in the environment are used.
3768 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3769 Enable the call to overwrite_console().
3771 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3772 Enable overwrite of previous console environment settings.
3774 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3775 Begin and End addresses of the area used by the
3778 - CONFIG_SYS_ALT_MEMTEST:
3779 Enable an alternate, more extensive memory test.
3781 - CONFIG_SYS_MEMTEST_SCRATCH:
3782 Scratch address used by the alternate memory test
3783 You only need to set this if address zero isn't writeable
3785 - CONFIG_SYS_MEM_RESERVE_SECURE
3786 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3787 is substracted from total RAM and won't be reported to OS.
3788 This memory can be used as secure memory. A variable
3789 gd->secure_ram is used to track the location. In systems
3790 the RAM base is not zero, or RAM is divided into banks,
3791 this variable needs to be recalcuated to get the address.
3793 - CONFIG_SYS_MEM_TOP_HIDE:
3794 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3795 this specified memory area will get subtracted from the top
3796 (end) of RAM and won't get "touched" at all by U-Boot. By
3797 fixing up gd->ram_size the Linux kernel should gets passed
3798 the now "corrected" memory size and won't touch it either.
3799 This should work for arch/ppc and arch/powerpc. Only Linux
3800 board ports in arch/powerpc with bootwrapper support that
3801 recalculate the memory size from the SDRAM controller setup
3802 will have to get fixed in Linux additionally.
3804 This option can be used as a workaround for the 440EPx/GRx
3805 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3808 WARNING: Please make sure that this value is a multiple of
3809 the Linux page size (normally 4k). If this is not the case,
3810 then the end address of the Linux memory will be located at a
3811 non page size aligned address and this could cause major
3814 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3815 Enable temporary baudrate change while serial download
3817 - CONFIG_SYS_SDRAM_BASE:
3818 Physical start address of SDRAM. _Must_ be 0 here.
3820 - CONFIG_SYS_MBIO_BASE:
3821 Physical start address of Motherboard I/O (if using a
3824 - CONFIG_SYS_FLASH_BASE:
3825 Physical start address of Flash memory.
3827 - CONFIG_SYS_MONITOR_BASE:
3828 Physical start address of boot monitor code (set by
3829 make config files to be same as the text base address
3830 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3831 CONFIG_SYS_FLASH_BASE when booting from flash.
3833 - CONFIG_SYS_MONITOR_LEN:
3834 Size of memory reserved for monitor code, used to
3835 determine _at_compile_time_ (!) if the environment is
3836 embedded within the U-Boot image, or in a separate
3839 - CONFIG_SYS_MALLOC_LEN:
3840 Size of DRAM reserved for malloc() use.
3842 - CONFIG_SYS_MALLOC_F_LEN
3843 Size of the malloc() pool for use before relocation. If
3844 this is defined, then a very simple malloc() implementation
3845 will become available before relocation. The address is just
3846 below the global data, and the stack is moved down to make
3849 This feature allocates regions with increasing addresses
3850 within the region. calloc() is supported, but realloc()
3851 is not available. free() is supported but does nothing.
3852 The memory will be freed (or in fact just forgotten) when
3853 U-Boot relocates itself.
3855 Pre-relocation malloc() is only supported on ARM and sandbox
3856 at present but is fairly easy to enable for other archs.
3858 - CONFIG_SYS_MALLOC_SIMPLE
3859 Provides a simple and small malloc() and calloc() for those
3860 boards which do not use the full malloc in SPL (which is
3861 enabled with CONFIG_SYS_SPL_MALLOC_START).
3863 - CONFIG_SYS_NONCACHED_MEMORY:
3864 Size of non-cached memory area. This area of memory will be
3865 typically located right below the malloc() area and mapped
3866 uncached in the MMU. This is useful for drivers that would
3867 otherwise require a lot of explicit cache maintenance. For
3868 some drivers it's also impossible to properly maintain the
3869 cache. For example if the regions that need to be flushed
3870 are not a multiple of the cache-line size, *and* padding
3871 cannot be allocated between the regions to align them (i.e.
3872 if the HW requires a contiguous array of regions, and the
3873 size of each region is not cache-aligned), then a flush of
3874 one region may result in overwriting data that hardware has
3875 written to another region in the same cache-line. This can
3876 happen for example in network drivers where descriptors for
3877 buffers are typically smaller than the CPU cache-line (e.g.
3878 16 bytes vs. 32 or 64 bytes).
3880 Non-cached memory is only supported on 32-bit ARM at present.
3882 - CONFIG_SYS_BOOTM_LEN:
3883 Normally compressed uImages are limited to an
3884 uncompressed size of 8 MBytes. If this is not enough,
3885 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3886 to adjust this setting to your needs.
3888 - CONFIG_SYS_BOOTMAPSZ:
3889 Maximum size of memory mapped by the startup code of
3890 the Linux kernel; all data that must be processed by
3891 the Linux kernel (bd_info, boot arguments, FDT blob if
3892 used) must be put below this limit, unless "bootm_low"
3893 environment variable is defined and non-zero. In such case
3894 all data for the Linux kernel must be between "bootm_low"
3895 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3896 variable "bootm_mapsize" will override the value of
3897 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3898 then the value in "bootm_size" will be used instead.
3900 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3901 Enable initrd_high functionality. If defined then the
3902 initrd_high feature is enabled and the bootm ramdisk subcommand
3905 - CONFIG_SYS_BOOT_GET_CMDLINE:
3906 Enables allocating and saving kernel cmdline in space between
3907 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3909 - CONFIG_SYS_BOOT_GET_KBD:
3910 Enables allocating and saving a kernel copy of the bd_info in
3911 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3913 - CONFIG_SYS_MAX_FLASH_BANKS:
3914 Max number of Flash memory banks
3916 - CONFIG_SYS_MAX_FLASH_SECT:
3917 Max number of sectors on a Flash chip
3919 - CONFIG_SYS_FLASH_ERASE_TOUT:
3920 Timeout for Flash erase operations (in ms)
3922 - CONFIG_SYS_FLASH_WRITE_TOUT:
3923 Timeout for Flash write operations (in ms)
3925 - CONFIG_SYS_FLASH_LOCK_TOUT
3926 Timeout for Flash set sector lock bit operation (in ms)
3928 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3929 Timeout for Flash clear lock bits operation (in ms)
3931 - CONFIG_SYS_FLASH_PROTECTION
3932 If defined, hardware flash sectors protection is used
3933 instead of U-Boot software protection.
3935 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3937 Enable TFTP transfers directly to flash memory;
3938 without this option such a download has to be
3939 performed in two steps: (1) download to RAM, and (2)
3940 copy from RAM to flash.
3942 The two-step approach is usually more reliable, since
3943 you can check if the download worked before you erase
3944 the flash, but in some situations (when system RAM is
3945 too limited to allow for a temporary copy of the
3946 downloaded image) this option may be very useful.
3948 - CONFIG_SYS_FLASH_CFI:
3949 Define if the flash driver uses extra elements in the
3950 common flash structure for storing flash geometry.
3952 - CONFIG_FLASH_CFI_DRIVER
3953 This option also enables the building of the cfi_flash driver
3954 in the drivers directory
3956 - CONFIG_FLASH_CFI_MTD
3957 This option enables the building of the cfi_mtd driver
3958 in the drivers directory. The driver exports CFI flash
3961 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3962 Use buffered writes to flash.
3964 - CONFIG_FLASH_SPANSION_S29WS_N
3965 s29ws-n MirrorBit flash has non-standard addresses for buffered
3968 - CONFIG_SYS_FLASH_QUIET_TEST
3969 If this option is defined, the common CFI flash doesn't
3970 print it's warning upon not recognized FLASH banks. This
3971 is useful, if some of the configured banks are only
3972 optionally available.
3974 - CONFIG_FLASH_SHOW_PROGRESS
3975 If defined (must be an integer), print out countdown
3976 digits and dots. Recommended value: 45 (9..1) for 80
3977 column displays, 15 (3..1) for 40 column displays.
3979 - CONFIG_FLASH_VERIFY
3980 If defined, the content of the flash (destination) is compared
3981 against the source after the write operation. An error message
3982 will be printed when the contents are not identical.
3983 Please note that this option is useless in nearly all cases,
3984 since such flash programming errors usually are detected earlier
3985 while unprotecting/erasing/programming. Please only enable
3986 this option if you really know what you are doing.
3988 - CONFIG_SYS_RX_ETH_BUFFER:
3989 Defines the number of Ethernet receive buffers. On some
3990 Ethernet controllers it is recommended to set this value
3991 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3992 buffers can be full shortly after enabling the interface
3993 on high Ethernet traffic.
3994 Defaults to 4 if not defined.
3996 - CONFIG_ENV_MAX_ENTRIES
3998 Maximum number of entries in the hash table that is used
3999 internally to store the environment settings. The default
4000 setting is supposed to be generous and should work in most
4001 cases. This setting can be used to tune behaviour; see
4002 lib/hashtable.c for details.
4004 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4005 - CONFIG_ENV_FLAGS_LIST_STATIC
4006 Enable validation of the values given to environment variables when
4007 calling env set. Variables can be restricted to only decimal,
4008 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4009 the variables can also be restricted to IP address or MAC address.
4011 The format of the list is:
4012 type_attribute = [s|d|x|b|i|m]
4013 access_attribute = [a|r|o|c]
4014 attributes = type_attribute[access_attribute]
4015 entry = variable_name[:attributes]
4018 The type attributes are:
4019 s - String (default)
4022 b - Boolean ([1yYtT|0nNfF])
4026 The access attributes are:
4032 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4033 Define this to a list (string) to define the ".flags"
4034 environment variable in the default or embedded environment.
4036 - CONFIG_ENV_FLAGS_LIST_STATIC
4037 Define this to a list (string) to define validation that
4038 should be done if an entry is not found in the ".flags"
4039 environment variable. To override a setting in the static
4040 list, simply add an entry for the same variable name to the
4043 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4044 regular expression. This allows multiple variables to define the same
4045 flags without explicitly listing them for each variable.
4047 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4048 If defined, don't allow the -f switch to env set override variable
4051 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4052 This is set by OMAP boards for the max time that reset should
4053 be asserted. See doc/README.omap-reset-time for details on how
4054 the value can be calculated on a given board.
4057 If stdint.h is available with your toolchain you can define this
4058 option to enable it. You can provide option 'USE_STDINT=1' when
4059 building U-Boot to enable this.
4061 The following definitions that deal with the placement and management
4062 of environment data (variable area); in general, we support the
4063 following configurations:
4065 - CONFIG_BUILD_ENVCRC:
4067 Builds up envcrc with the target environment so that external utils
4068 may easily extract it and embed it in final U-Boot images.
4070 - CONFIG_ENV_IS_IN_FLASH:
4072 Define this if the environment is in flash memory.
4074 a) The environment occupies one whole flash sector, which is
4075 "embedded" in the text segment with the U-Boot code. This
4076 happens usually with "bottom boot sector" or "top boot
4077 sector" type flash chips, which have several smaller
4078 sectors at the start or the end. For instance, such a
4079 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4080 such a case you would place the environment in one of the
4081 4 kB sectors - with U-Boot code before and after it. With
4082 "top boot sector" type flash chips, you would put the
4083 environment in one of the last sectors, leaving a gap
4084 between U-Boot and the environment.
4086 - CONFIG_ENV_OFFSET:
4088 Offset of environment data (variable area) to the
4089 beginning of flash memory; for instance, with bottom boot
4090 type flash chips the second sector can be used: the offset
4091 for this sector is given here.
4093 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4097 This is just another way to specify the start address of
4098 the flash sector containing the environment (instead of
4101 - CONFIG_ENV_SECT_SIZE:
4103 Size of the sector containing the environment.
4106 b) Sometimes flash chips have few, equal sized, BIG sectors.
4107 In such a case you don't want to spend a whole sector for
4112 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4113 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4114 of this flash sector for the environment. This saves
4115 memory for the RAM copy of the environment.
4117 It may also save flash memory if you decide to use this
4118 when your environment is "embedded" within U-Boot code,
4119 since then the remainder of the flash sector could be used
4120 for U-Boot code. It should be pointed out that this is
4121 STRONGLY DISCOURAGED from a robustness point of view:
4122 updating the environment in flash makes it always
4123 necessary to erase the WHOLE sector. If something goes
4124 wrong before the contents has been restored from a copy in
4125 RAM, your target system will be dead.
4127 - CONFIG_ENV_ADDR_REDUND
4128 CONFIG_ENV_SIZE_REDUND
4130 These settings describe a second storage area used to hold
4131 a redundant copy of the environment data, so that there is
4132 a valid backup copy in case there is a power failure during
4133 a "saveenv" operation.
4135 BE CAREFUL! Any changes to the flash layout, and some changes to the
4136 source code will make it necessary to adapt <board>/u-boot.lds*
4140 - CONFIG_ENV_IS_IN_NVRAM:
4142 Define this if you have some non-volatile memory device
4143 (NVRAM, battery buffered SRAM) which you want to use for the
4149 These two #defines are used to determine the memory area you
4150 want to use for environment. It is assumed that this memory
4151 can just be read and written to, without any special
4154 BE CAREFUL! The first access to the environment happens quite early
4155 in U-Boot initialization (when we try to get the setting of for the
4156 console baudrate). You *MUST* have mapped your NVRAM area then, or
4159 Please note that even with NVRAM we still use a copy of the
4160 environment in RAM: we could work on NVRAM directly, but we want to
4161 keep settings there always unmodified except somebody uses "saveenv"
4162 to save the current settings.
4165 - CONFIG_ENV_IS_IN_EEPROM:
4167 Use this if you have an EEPROM or similar serial access
4168 device and a driver for it.
4170 - CONFIG_ENV_OFFSET:
4173 These two #defines specify the offset and size of the
4174 environment area within the total memory of your EEPROM.
4176 - CONFIG_SYS_I2C_EEPROM_ADDR:
4177 If defined, specified the chip address of the EEPROM device.
4178 The default address is zero.
4180 - CONFIG_SYS_I2C_EEPROM_BUS:
4181 If defined, specified the i2c bus of the EEPROM device.
4183 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4184 If defined, the number of bits used to address bytes in a
4185 single page in the EEPROM device. A 64 byte page, for example
4186 would require six bits.
4188 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4189 If defined, the number of milliseconds to delay between
4190 page writes. The default is zero milliseconds.
4192 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4193 The length in bytes of the EEPROM memory array address. Note
4194 that this is NOT the chip address length!
4196 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4197 EEPROM chips that implement "address overflow" are ones
4198 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4199 address and the extra bits end up in the "chip address" bit
4200 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4203 Note that we consider the length of the address field to
4204 still be one byte because the extra address bits are hidden
4205 in the chip address.
4207 - CONFIG_SYS_EEPROM_SIZE:
4208 The size in bytes of the EEPROM device.
4210 - CONFIG_ENV_EEPROM_IS_ON_I2C
4211 define this, if you have I2C and SPI activated, and your
4212 EEPROM, which holds the environment, is on the I2C bus.
4214 - CONFIG_I2C_ENV_EEPROM_BUS
4215 if you have an Environment on an EEPROM reached over
4216 I2C muxes, you can define here, how to reach this
4217 EEPROM. For example:
4219 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4221 EEPROM which holds the environment, is reached over
4222 a pca9547 i2c mux with address 0x70, channel 3.
4224 - CONFIG_ENV_IS_IN_DATAFLASH:
4226 Define this if you have a DataFlash memory device which you
4227 want to use for the environment.
4229 - CONFIG_ENV_OFFSET:
4233 These three #defines specify the offset and size of the
4234 environment area within the total memory of your DataFlash placed
4235 at the specified address.
4237 - CONFIG_ENV_IS_IN_SPI_FLASH:
4239 Define this if you have a SPI Flash memory device which you
4240 want to use for the environment.
4242 - CONFIG_ENV_OFFSET:
4245 These two #defines specify the offset and size of the
4246 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4247 aligned to an erase sector boundary.
4249 - CONFIG_ENV_SECT_SIZE:
4251 Define the SPI flash's sector size.
4253 - CONFIG_ENV_OFFSET_REDUND (optional):
4255 This setting describes a second storage area of CONFIG_ENV_SIZE
4256 size used to hold a redundant copy of the environment data, so
4257 that there is a valid backup copy in case there is a power failure
4258 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4259 aligned to an erase sector boundary.
4261 - CONFIG_ENV_SPI_BUS (optional):
4262 - CONFIG_ENV_SPI_CS (optional):
4264 Define the SPI bus and chip select. If not defined they will be 0.
4266 - CONFIG_ENV_SPI_MAX_HZ (optional):
4268 Define the SPI max work clock. If not defined then use 1MHz.
4270 - CONFIG_ENV_SPI_MODE (optional):
4272 Define the SPI work mode. If not defined then use SPI_MODE_3.
4274 - CONFIG_ENV_IS_IN_REMOTE:
4276 Define this if you have a remote memory space which you
4277 want to use for the local device's environment.
4282 These two #defines specify the address and size of the
4283 environment area within the remote memory space. The
4284 local device can get the environment from remote memory
4285 space by SRIO or PCIE links.
4287 BE CAREFUL! For some special cases, the local device can not use
4288 "saveenv" command. For example, the local device will get the
4289 environment stored in a remote NOR flash by SRIO or PCIE link,
4290 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4292 - CONFIG_ENV_IS_IN_NAND:
4294 Define this if you have a NAND device which you want to use
4295 for the environment.
4297 - CONFIG_ENV_OFFSET:
4300 These two #defines specify the offset and size of the environment
4301 area within the first NAND device. CONFIG_ENV_OFFSET must be
4302 aligned to an erase block boundary.
4304 - CONFIG_ENV_OFFSET_REDUND (optional):
4306 This setting describes a second storage area of CONFIG_ENV_SIZE
4307 size used to hold a redundant copy of the environment data, so
4308 that there is a valid backup copy in case there is a power failure
4309 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4310 aligned to an erase block boundary.
4312 - CONFIG_ENV_RANGE (optional):
4314 Specifies the length of the region in which the environment
4315 can be written. This should be a multiple of the NAND device's
4316 block size. Specifying a range with more erase blocks than
4317 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4318 the range to be avoided.
4320 - CONFIG_ENV_OFFSET_OOB (optional):
4322 Enables support for dynamically retrieving the offset of the
4323 environment from block zero's out-of-band data. The
4324 "nand env.oob" command can be used to record this offset.
4325 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4326 using CONFIG_ENV_OFFSET_OOB.
4328 - CONFIG_NAND_ENV_DST
4330 Defines address in RAM to which the nand_spl code should copy the
4331 environment. If redundant environment is used, it will be copied to
4332 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4334 - CONFIG_ENV_IS_IN_UBI:
4336 Define this if you have an UBI volume that you want to use for the
4337 environment. This has the benefit of wear-leveling the environment
4338 accesses, which is important on NAND.
4340 - CONFIG_ENV_UBI_PART:
4342 Define this to a string that is the mtd partition containing the UBI.
4344 - CONFIG_ENV_UBI_VOLUME:
4346 Define this to the name of the volume that you want to store the
4349 - CONFIG_ENV_UBI_VOLUME_REDUND:
4351 Define this to the name of another volume to store a second copy of
4352 the environment in. This will enable redundant environments in UBI.
4353 It is assumed that both volumes are in the same MTD partition.
4355 - CONFIG_UBI_SILENCE_MSG
4356 - CONFIG_UBIFS_SILENCE_MSG
4358 You will probably want to define these to avoid a really noisy system
4359 when storing the env in UBI.
4361 - CONFIG_ENV_IS_IN_FAT:
4362 Define this if you want to use the FAT file system for the environment.
4364 - FAT_ENV_INTERFACE:
4366 Define this to a string that is the name of the block device.
4368 - FAT_ENV_DEV_AND_PART:
4370 Define this to a string to specify the partition of the device. It can
4373 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4374 - "D:P": device D partition P. Error occurs if device D has no
4377 - "D" or "D:": device D partition 1 if device D has partition
4378 table, or the whole device D if has no partition
4380 - "D:auto": first partition in device D with bootable flag set.
4381 If none, first valid partition in device D. If no
4382 partition table then means device D.
4386 It's a string of the FAT file name. This file use to store the
4390 This should be defined. Otherwise it cannot save the environment file.
4392 - CONFIG_ENV_IS_IN_MMC:
4394 Define this if you have an MMC device which you want to use for the
4397 - CONFIG_SYS_MMC_ENV_DEV:
4399 Specifies which MMC device the environment is stored in.
4401 - CONFIG_SYS_MMC_ENV_PART (optional):
4403 Specifies which MMC partition the environment is stored in. If not
4404 set, defaults to partition 0, the user area. Common values might be
4405 1 (first MMC boot partition), 2 (second MMC boot partition).
4407 - CONFIG_ENV_OFFSET:
4410 These two #defines specify the offset and size of the environment
4411 area within the specified MMC device.
4413 If offset is positive (the usual case), it is treated as relative to
4414 the start of the MMC partition. If offset is negative, it is treated
4415 as relative to the end of the MMC partition. This can be useful if
4416 your board may be fitted with different MMC devices, which have
4417 different sizes for the MMC partitions, and you always want the
4418 environment placed at the very end of the partition, to leave the
4419 maximum possible space before it, to store other data.
4421 These two values are in units of bytes, but must be aligned to an
4422 MMC sector boundary.
4424 - CONFIG_ENV_OFFSET_REDUND (optional):
4426 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4427 hold a redundant copy of the environment data. This provides a
4428 valid backup copy in case the other copy is corrupted, e.g. due
4429 to a power failure during a "saveenv" operation.
4431 This value may also be positive or negative; this is handled in the
4432 same way as CONFIG_ENV_OFFSET.
4434 This value is also in units of bytes, but must also be aligned to
4435 an MMC sector boundary.
4437 - CONFIG_ENV_SIZE_REDUND (optional):
4439 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4440 set. If this value is set, it must be set to the same value as
4443 - CONFIG_SYS_SPI_INIT_OFFSET
4445 Defines offset to the initial SPI buffer area in DPRAM. The
4446 area is used at an early stage (ROM part) if the environment
4447 is configured to reside in the SPI EEPROM: We need a 520 byte
4448 scratch DPRAM area. It is used between the two initialization
4449 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4450 to be a good choice since it makes it far enough from the
4451 start of the data area as well as from the stack pointer.
4453 Please note that the environment is read-only until the monitor
4454 has been relocated to RAM and a RAM copy of the environment has been
4455 created; also, when using EEPROM you will have to use getenv_f()
4456 until then to read environment variables.
4458 The environment is protected by a CRC32 checksum. Before the monitor
4459 is relocated into RAM, as a result of a bad CRC you will be working
4460 with the compiled-in default environment - *silently*!!! [This is
4461 necessary, because the first environment variable we need is the
4462 "baudrate" setting for the console - if we have a bad CRC, we don't
4463 have any device yet where we could complain.]
4465 Note: once the monitor has been relocated, then it will complain if
4466 the default environment is used; a new CRC is computed as soon as you
4467 use the "saveenv" command to store a valid environment.
4469 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4470 Echo the inverted Ethernet link state to the fault LED.
4472 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4473 also needs to be defined.
4475 - CONFIG_SYS_FAULT_MII_ADDR:
4476 MII address of the PHY to check for the Ethernet link state.
4478 - CONFIG_NS16550_MIN_FUNCTIONS:
4479 Define this if you desire to only have use of the NS16550_init
4480 and NS16550_putc functions for the serial driver located at
4481 drivers/serial/ns16550.c. This option is useful for saving
4482 space for already greatly restricted images, including but not
4483 limited to NAND_SPL configurations.
4485 - CONFIG_DISPLAY_BOARDINFO
4486 Display information about the board that U-Boot is running on
4487 when U-Boot starts up. The board function checkboard() is called
4490 - CONFIG_DISPLAY_BOARDINFO_LATE
4491 Similar to the previous option, but display this information
4492 later, once stdio is running and output goes to the LCD, if
4495 - CONFIG_BOARD_SIZE_LIMIT:
4496 Maximum size of the U-Boot image. When defined, the
4497 build system checks that the actual size does not
4500 Low Level (hardware related) configuration options:
4501 ---------------------------------------------------
4503 - CONFIG_SYS_CACHELINE_SIZE:
4504 Cache Line Size of the CPU.
4506 - CONFIG_SYS_DEFAULT_IMMR:
4507 Default address of the IMMR after system reset.
4509 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4510 and RPXsuper) to be able to adjust the position of
4511 the IMMR register after a reset.
4513 - CONFIG_SYS_CCSRBAR_DEFAULT:
4514 Default (power-on reset) physical address of CCSR on Freescale
4517 - CONFIG_SYS_CCSRBAR:
4518 Virtual address of CCSR. On a 32-bit build, this is typically
4519 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4521 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4522 for cross-platform code that uses that macro instead.
4524 - CONFIG_SYS_CCSRBAR_PHYS:
4525 Physical address of CCSR. CCSR can be relocated to a new
4526 physical address, if desired. In this case, this macro should
4527 be set to that address. Otherwise, it should be set to the
4528 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4529 is typically relocated on 36-bit builds. It is recommended
4530 that this macro be defined via the _HIGH and _LOW macros:
4532 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4533 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4535 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4536 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4537 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4538 used in assembly code, so it must not contain typecasts or
4539 integer size suffixes (e.g. "ULL").
4541 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4542 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4543 used in assembly code, so it must not contain typecasts or
4544 integer size suffixes (e.g. "ULL").
4546 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4547 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4548 forced to a value that ensures that CCSR is not relocated.
4550 - Floppy Disk Support:
4551 CONFIG_SYS_FDC_DRIVE_NUMBER
4553 the default drive number (default value 0)
4555 CONFIG_SYS_ISA_IO_STRIDE
4557 defines the spacing between FDC chipset registers
4560 CONFIG_SYS_ISA_IO_OFFSET
4562 defines the offset of register from address. It
4563 depends on which part of the data bus is connected to
4564 the FDC chipset. (default value 0)
4566 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4567 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4570 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4571 fdc_hw_init() is called at the beginning of the FDC
4572 setup. fdc_hw_init() must be provided by the board
4573 source code. It is used to make hardware-dependent
4577 Most IDE controllers were designed to be connected with PCI
4578 interface. Only few of them were designed for AHB interface.
4579 When software is doing ATA command and data transfer to
4580 IDE devices through IDE-AHB controller, some additional
4581 registers accessing to these kind of IDE-AHB controller
4584 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4585 DO NOT CHANGE unless you know exactly what you're
4586 doing! (11-4) [MPC8xx/82xx systems only]
4588 - CONFIG_SYS_INIT_RAM_ADDR:
4590 Start address of memory area that can be used for
4591 initial data and stack; please note that this must be
4592 writable memory that is working WITHOUT special
4593 initialization, i. e. you CANNOT use normal RAM which
4594 will become available only after programming the
4595 memory controller and running certain initialization
4598 U-Boot uses the following memory types:
4599 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4600 - MPC824X: data cache
4601 - PPC4xx: data cache
4603 - CONFIG_SYS_GBL_DATA_OFFSET:
4605 Offset of the initial data structure in the memory
4606 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4607 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4608 data is located at the end of the available space
4609 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4610 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4611 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4612 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4615 On the MPC824X (or other systems that use the data
4616 cache for initial memory) the address chosen for
4617 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4618 point to an otherwise UNUSED address space between
4619 the top of RAM and the start of the PCI space.
4621 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4623 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4625 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4627 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4629 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4631 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4633 - CONFIG_SYS_OR_TIMING_SDRAM:
4636 - CONFIG_SYS_MAMR_PTA:
4637 periodic timer for refresh
4639 - CONFIG_SYS_DER: Debug Event Register (37-47)
4641 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4642 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4643 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4644 CONFIG_SYS_BR1_PRELIM:
4645 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4647 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4648 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4649 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4650 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4652 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4653 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4654 Machine Mode Register and Memory Periodic Timer
4655 Prescaler definitions (SDRAM timing)
4657 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4658 enable I2C microcode relocation patch (MPC8xx);
4659 define relocation offset in DPRAM [DSP2]
4661 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4662 enable SMC microcode relocation patch (MPC8xx);
4663 define relocation offset in DPRAM [SMC1]
4665 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4666 enable SPI microcode relocation patch (MPC8xx);
4667 define relocation offset in DPRAM [SCC4]
4669 - CONFIG_SYS_USE_OSCCLK:
4670 Use OSCM clock mode on MBX8xx board. Be careful,
4671 wrong setting might damage your board. Read
4672 doc/README.MBX before setting this variable!
4674 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4675 Offset of the bootmode word in DPRAM used by post
4676 (Power On Self Tests). This definition overrides
4677 #define'd default value in commproc.h resp.
4680 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4681 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4682 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4683 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4684 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4685 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4686 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4687 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4688 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4690 - CONFIG_PCI_DISABLE_PCIE:
4691 Disable PCI-Express on systems where it is supported but not
4694 - CONFIG_PCI_ENUM_ONLY
4695 Only scan through and get the devices on the buses.
4696 Don't do any setup work, presumably because someone or
4697 something has already done it, and we don't need to do it
4698 a second time. Useful for platforms that are pre-booted
4699 by coreboot or similar.
4701 - CONFIG_PCI_INDIRECT_BRIDGE:
4702 Enable support for indirect PCI bridges.
4705 Chip has SRIO or not
4708 Board has SRIO 1 port available
4711 Board has SRIO 2 port available
4713 - CONFIG_SRIO_PCIE_BOOT_MASTER
4714 Board can support master function for Boot from SRIO and PCIE
4716 - CONFIG_SYS_SRIOn_MEM_VIRT:
4717 Virtual Address of SRIO port 'n' memory region
4719 - CONFIG_SYS_SRIOn_MEM_PHYS:
4720 Physical Address of SRIO port 'n' memory region
4722 - CONFIG_SYS_SRIOn_MEM_SIZE:
4723 Size of SRIO port 'n' memory region
4725 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4726 Defined to tell the NAND controller that the NAND chip is using
4728 Not all NAND drivers use this symbol.
4729 Example of drivers that use it:
4730 - drivers/mtd/nand/ndfc.c
4731 - drivers/mtd/nand/mxc_nand.c
4733 - CONFIG_SYS_NDFC_EBC0_CFG
4734 Sets the EBC0_CFG register for the NDFC. If not defined
4735 a default value will be used.
4738 Get DDR timing information from an I2C EEPROM. Common
4739 with pluggable memory modules such as SODIMMs
4742 I2C address of the SPD EEPROM
4744 - CONFIG_SYS_SPD_BUS_NUM
4745 If SPD EEPROM is on an I2C bus other than the first
4746 one, specify here. Note that the value must resolve
4747 to something your driver can deal with.
4749 - CONFIG_SYS_DDR_RAW_TIMING
4750 Get DDR timing information from other than SPD. Common with
4751 soldered DDR chips onboard without SPD. DDR raw timing
4752 parameters are extracted from datasheet and hard-coded into
4753 header files or board specific files.
4755 - CONFIG_FSL_DDR_INTERACTIVE
4756 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4758 - CONFIG_FSL_DDR_SYNC_REFRESH
4759 Enable sync of refresh for multiple controllers.
4761 - CONFIG_FSL_DDR_BIST
4762 Enable built-in memory test for Freescale DDR controllers.
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 Freescale Layerscape Debug Server Support:
4951 -------------------------------------------
4952 The Freescale Layerscape Debug Server Support supports the loading of
4953 "Debug Server firmware" and triggering SP boot-rom.
4954 This firmware often needs to be loaded during U-Boot booting.
4956 - CONFIG_FSL_DEBUG_SERVER
4957 Enable the Debug Server for Layerscape SoCs.
4959 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
4960 Define minimum DDR size required for debug server image
4962 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4963 Define alignment of reserved memory MC requires
4968 In order to achieve reproducible builds, timestamps used in the U-Boot build
4969 process have to be set to a fixed value.
4971 This is done using the SOURCE_DATE_EPOCH environment variable.
4972 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4973 option for U-Boot or an environment variable in U-Boot.
4975 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4977 Building the Software:
4978 ======================
4980 Building U-Boot has been tested in several native build environments
4981 and in many different cross environments. Of course we cannot support
4982 all possibly existing versions of cross development tools in all
4983 (potentially obsolete) versions. In case of tool chain problems we
4984 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4985 which is extensively used to build and test U-Boot.
4987 If you are not using a native environment, it is assumed that you
4988 have GNU cross compiling tools available in your path. In this case,
4989 you must set the environment variable CROSS_COMPILE in your shell.
4990 Note that no changes to the Makefile or any other source files are
4991 necessary. For example using the ELDK on a 4xx CPU, please enter:
4993 $ CROSS_COMPILE=ppc_4xx-
4994 $ export CROSS_COMPILE
4996 Note: If you wish to generate Windows versions of the utilities in
4997 the tools directory you can use the MinGW toolchain
4998 (http://www.mingw.org). Set your HOST tools to the MinGW
4999 toolchain and execute 'make tools'. For example:
5001 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5003 Binaries such as tools/mkimage.exe will be created which can
5004 be executed on computers running Windows.
5006 U-Boot is intended to be simple to build. After installing the
5007 sources you must configure U-Boot for one specific board type. This
5012 where "NAME_defconfig" is the name of one of the existing configu-
5013 rations; see boards.cfg for supported names.
5015 Note: for some board special configuration names may exist; check if
5016 additional information is available from the board vendor; for
5017 instance, the TQM823L systems are available without (standard)
5018 or with LCD support. You can select such additional "features"
5019 when choosing the configuration, i. e.
5021 make TQM823L_defconfig
5022 - will configure for a plain TQM823L, i. e. no LCD support
5024 make TQM823L_LCD_defconfig
5025 - will configure for a TQM823L with U-Boot console on LCD
5030 Finally, type "make all", and you should get some working U-Boot
5031 images ready for download to / installation on your system:
5033 - "u-boot.bin" is a raw binary image
5034 - "u-boot" is an image in ELF binary format
5035 - "u-boot.srec" is in Motorola S-Record format
5037 By default the build is performed locally and the objects are saved
5038 in the source directory. One of the two methods can be used to change
5039 this behavior and build U-Boot to some external directory:
5041 1. Add O= to the make command line invocations:
5043 make O=/tmp/build distclean
5044 make O=/tmp/build NAME_defconfig
5045 make O=/tmp/build all
5047 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5049 export KBUILD_OUTPUT=/tmp/build
5054 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5058 Please be aware that the Makefiles assume you are using GNU make, so
5059 for instance on NetBSD you might need to use "gmake" instead of
5063 If the system board that you have is not listed, then you will need
5064 to port U-Boot to your hardware platform. To do this, follow these
5067 1. Create a new directory to hold your board specific code. Add any
5068 files you need. In your board directory, you will need at least
5069 the "Makefile" and a "<board>.c".
5070 2. Create a new configuration file "include/configs/<board>.h" for
5072 3. If you're porting U-Boot to a new CPU, then also create a new
5073 directory to hold your CPU specific code. Add any files you need.
5074 4. Run "make <board>_defconfig" with your new name.
5075 5. Type "make", and you should get a working "u-boot.srec" file
5076 to be installed on your target system.
5077 6. Debug and solve any problems that might arise.
5078 [Of course, this last step is much harder than it sounds.]
5081 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5082 ==============================================================
5084 If you have modified U-Boot sources (for instance added a new board
5085 or support for new devices, a new CPU, etc.) you are expected to
5086 provide feedback to the other developers. The feedback normally takes
5087 the form of a "patch", i. e. a context diff against a certain (latest
5088 official or latest in the git repository) version of U-Boot sources.
5090 But before you submit such a patch, please verify that your modifi-
5091 cation did not break existing code. At least make sure that *ALL* of
5092 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5093 just run the "MAKEALL" script, which will configure and build U-Boot
5094 for ALL supported system. Be warned, this will take a while. You can
5095 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5096 environment variable to the script, i. e. to use the ELDK cross tools
5099 CROSS_COMPILE=ppc_8xx- MAKEALL
5101 or to build on a native PowerPC system you can type
5103 CROSS_COMPILE=' ' MAKEALL
5105 When using the MAKEALL script, the default behaviour is to build
5106 U-Boot in the source directory. This location can be changed by
5107 setting the BUILD_DIR environment variable. Also, for each target
5108 built, the MAKEALL script saves two log files (<target>.ERR and
5109 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5110 location can be changed by setting the MAKEALL_LOGDIR environment
5111 variable. For example:
5113 export BUILD_DIR=/tmp/build
5114 export MAKEALL_LOGDIR=/tmp/log
5115 CROSS_COMPILE=ppc_8xx- MAKEALL
5117 With the above settings build objects are saved in the /tmp/build,
5118 log files are saved in the /tmp/log and the source tree remains clean
5119 during the whole build process.
5122 See also "U-Boot Porting Guide" below.
5125 Monitor Commands - Overview:
5126 ============================
5128 go - start application at address 'addr'
5129 run - run commands in an environment variable
5130 bootm - boot application image from memory
5131 bootp - boot image via network using BootP/TFTP protocol
5132 bootz - boot zImage from memory
5133 tftpboot- boot image via network using TFTP protocol
5134 and env variables "ipaddr" and "serverip"
5135 (and eventually "gatewayip")
5136 tftpput - upload a file via network using TFTP protocol
5137 rarpboot- boot image via network using RARP/TFTP protocol
5138 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5139 loads - load S-Record file over serial line
5140 loadb - load binary file over serial line (kermit mode)
5142 mm - memory modify (auto-incrementing)
5143 nm - memory modify (constant address)
5144 mw - memory write (fill)
5146 cmp - memory compare
5147 crc32 - checksum calculation
5148 i2c - I2C sub-system
5149 sspi - SPI utility commands
5150 base - print or set address offset
5151 printenv- print environment variables
5152 setenv - set environment variables
5153 saveenv - save environment variables to persistent storage
5154 protect - enable or disable FLASH write protection
5155 erase - erase FLASH memory
5156 flinfo - print FLASH memory information
5157 nand - NAND memory operations (see doc/README.nand)
5158 bdinfo - print Board Info structure
5159 iminfo - print header information for application image
5160 coninfo - print console devices and informations
5161 ide - IDE sub-system
5162 loop - infinite loop on address range
5163 loopw - infinite write loop on address range
5164 mtest - simple RAM test
5165 icache - enable or disable instruction cache
5166 dcache - enable or disable data cache
5167 reset - Perform RESET of the CPU
5168 echo - echo args to console
5169 version - print monitor version
5170 help - print online help
5171 ? - alias for 'help'
5174 Monitor Commands - Detailed Description:
5175 ========================================
5179 For now: just type "help <command>".
5182 Environment Variables:
5183 ======================
5185 U-Boot supports user configuration using Environment Variables which
5186 can be made persistent by saving to Flash memory.
5188 Environment Variables are set using "setenv", printed using
5189 "printenv", and saved to Flash using "saveenv". Using "setenv"
5190 without a value can be used to delete a variable from the
5191 environment. As long as you don't save the environment you are
5192 working with an in-memory copy. In case the Flash area containing the
5193 environment is erased by accident, a default environment is provided.
5195 Some configuration options can be set using Environment Variables.
5197 List of environment variables (most likely not complete):
5199 baudrate - see CONFIG_BAUDRATE
5201 bootdelay - see CONFIG_BOOTDELAY
5203 bootcmd - see CONFIG_BOOTCOMMAND
5205 bootargs - Boot arguments when booting an RTOS image
5207 bootfile - Name of the image to load with TFTP
5209 bootm_low - Memory range available for image processing in the bootm
5210 command can be restricted. This variable is given as
5211 a hexadecimal number and defines lowest address allowed
5212 for use by the bootm command. See also "bootm_size"
5213 environment variable. Address defined by "bootm_low" is
5214 also the base of the initial memory mapping for the Linux
5215 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5218 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5219 This variable is given as a hexadecimal number and it
5220 defines the size of the memory region starting at base
5221 address bootm_low that is accessible by the Linux kernel
5222 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5223 as the default value if it is defined, and bootm_size is
5226 bootm_size - Memory range available for image processing in the bootm
5227 command can be restricted. This variable is given as
5228 a hexadecimal number and defines the size of the region
5229 allowed for use by the bootm command. See also "bootm_low"
5230 environment variable.
5232 updatefile - Location of the software update file on a TFTP server, used
5233 by the automatic software update feature. Please refer to
5234 documentation in doc/README.update for more details.
5236 autoload - if set to "no" (any string beginning with 'n'),
5237 "bootp" will just load perform a lookup of the
5238 configuration from the BOOTP server, but not try to
5239 load any image using TFTP
5241 autostart - if set to "yes", an image loaded using the "bootp",
5242 "rarpboot", "tftpboot" or "diskboot" commands will
5243 be automatically started (by internally calling
5246 If set to "no", a standalone image passed to the
5247 "bootm" command will be copied to the load address
5248 (and eventually uncompressed), but NOT be started.
5249 This can be used to load and uncompress arbitrary
5252 fdt_high - if set this restricts the maximum address that the
5253 flattened device tree will be copied into upon boot.
5254 For example, if you have a system with 1 GB memory
5255 at physical address 0x10000000, while Linux kernel
5256 only recognizes the first 704 MB as low memory, you
5257 may need to set fdt_high as 0x3C000000 to have the
5258 device tree blob be copied to the maximum address
5259 of the 704 MB low memory, so that Linux kernel can
5260 access it during the boot procedure.
5262 If this is set to the special value 0xFFFFFFFF then
5263 the fdt will not be copied at all on boot. For this
5264 to work it must reside in writable memory, have
5265 sufficient padding on the end of it for u-boot to
5266 add the information it needs into it, and the memory
5267 must be accessible by the kernel.
5269 fdtcontroladdr- if set this is the address of the control flattened
5270 device tree used by U-Boot when CONFIG_OF_CONTROL is
5273 i2cfast - (PPC405GP|PPC405EP only)
5274 if set to 'y' configures Linux I2C driver for fast
5275 mode (400kHZ). This environment variable is used in
5276 initialization code. So, for changes to be effective
5277 it must be saved and board must be reset.
5279 initrd_high - restrict positioning of initrd images:
5280 If this variable is not set, initrd images will be
5281 copied to the highest possible address in RAM; this
5282 is usually what you want since it allows for
5283 maximum initrd size. If for some reason you want to
5284 make sure that the initrd image is loaded below the
5285 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5286 variable to a value of "no" or "off" or "0".
5287 Alternatively, you can set it to a maximum upper
5288 address to use (U-Boot will still check that it
5289 does not overwrite the U-Boot stack and data).
5291 For instance, when you have a system with 16 MB
5292 RAM, and want to reserve 4 MB from use by Linux,
5293 you can do this by adding "mem=12M" to the value of
5294 the "bootargs" variable. However, now you must make
5295 sure that the initrd image is placed in the first
5296 12 MB as well - this can be done with
5298 setenv initrd_high 00c00000
5300 If you set initrd_high to 0xFFFFFFFF, this is an
5301 indication to U-Boot that all addresses are legal
5302 for the Linux kernel, including addresses in flash
5303 memory. In this case U-Boot will NOT COPY the
5304 ramdisk at all. This may be useful to reduce the
5305 boot time on your system, but requires that this
5306 feature is supported by your Linux kernel.
5308 ipaddr - IP address; needed for tftpboot command
5310 loadaddr - Default load address for commands like "bootp",
5311 "rarpboot", "tftpboot", "loadb" or "diskboot"
5313 loads_echo - see CONFIG_LOADS_ECHO
5315 serverip - TFTP server IP address; needed for tftpboot command
5317 bootretry - see CONFIG_BOOT_RETRY_TIME
5319 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5321 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5323 ethprime - controls which interface is used first.
5325 ethact - controls which interface is currently active.
5326 For example you can do the following
5328 => setenv ethact FEC
5329 => ping 192.168.0.1 # traffic sent on FEC
5330 => setenv ethact SCC
5331 => ping 10.0.0.1 # traffic sent on SCC
5333 ethrotate - When set to "no" U-Boot does not go through all
5334 available network interfaces.
5335 It just stays at the currently selected interface.
5337 netretry - When set to "no" each network operation will
5338 either succeed or fail without retrying.
5339 When set to "once" the network operation will
5340 fail when all the available network interfaces
5341 are tried once without success.
5342 Useful on scripts which control the retry operation
5345 npe_ucode - set load address for the NPE microcode
5347 silent_linux - If set then Linux will be told to boot silently, by
5348 changing the console to be empty. If "yes" it will be
5349 made silent. If "no" it will not be made silent. If
5350 unset, then it will be made silent if the U-Boot console
5353 tftpsrcp - If this is set, the value is used for TFTP's
5356 tftpdstp - If this is set, the value is used for TFTP's UDP
5357 destination port instead of the Well Know Port 69.
5359 tftpblocksize - Block size to use for TFTP transfers; if not set,
5360 we use the TFTP server's default block size
5362 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5363 seconds, minimum value is 1000 = 1 second). Defines
5364 when a packet is considered to be lost so it has to
5365 be retransmitted. The default is 5000 = 5 seconds.
5366 Lowering this value may make downloads succeed
5367 faster in networks with high packet loss rates or
5368 with unreliable TFTP servers.
5370 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5371 unit, minimum value = 0). Defines how many timeouts
5372 can happen during a single file transfer before that
5373 transfer is aborted. The default is 10, and 0 means
5374 'no timeouts allowed'. Increasing this value may help
5375 downloads succeed with high packet loss rates, or with
5376 unreliable TFTP servers or client hardware.
5378 vlan - When set to a value < 4095 the traffic over
5379 Ethernet is encapsulated/received over 802.1q
5382 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5383 Unsigned value, in milliseconds. If not set, the period will
5384 be either the default (28000), or a value based on
5385 CONFIG_NET_RETRY_COUNT, if defined. This value has
5386 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5388 The following image location variables contain the location of images
5389 used in booting. The "Image" column gives the role of the image and is
5390 not an environment variable name. The other columns are environment
5391 variable names. "File Name" gives the name of the file on a TFTP
5392 server, "RAM Address" gives the location in RAM the image will be
5393 loaded to, and "Flash Location" gives the image's address in NOR
5394 flash or offset in NAND flash.
5396 *Note* - these variables don't have to be defined for all boards, some
5397 boards currently use other variables for these purposes, and some
5398 boards use these variables for other purposes.
5400 Image File Name RAM Address Flash Location
5401 ----- --------- ----------- --------------
5402 u-boot u-boot u-boot_addr_r u-boot_addr
5403 Linux kernel bootfile kernel_addr_r kernel_addr
5404 device tree blob fdtfile fdt_addr_r fdt_addr
5405 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5407 The following environment variables may be used and automatically
5408 updated by the network boot commands ("bootp" and "rarpboot"),
5409 depending the information provided by your boot server:
5411 bootfile - see above
5412 dnsip - IP address of your Domain Name Server
5413 dnsip2 - IP address of your secondary Domain Name Server
5414 gatewayip - IP address of the Gateway (Router) to use
5415 hostname - Target hostname
5417 netmask - Subnet Mask
5418 rootpath - Pathname of the root filesystem on the NFS server
5419 serverip - see above
5422 There are two special Environment Variables:
5424 serial# - contains hardware identification information such
5425 as type string and/or serial number
5426 ethaddr - Ethernet address
5428 These variables can be set only once (usually during manufacturing of
5429 the board). U-Boot refuses to delete or overwrite these variables
5430 once they have been set once.
5433 Further special Environment Variables:
5435 ver - Contains the U-Boot version string as printed
5436 with the "version" command. This variable is
5437 readonly (see CONFIG_VERSION_VARIABLE).
5440 Please note that changes to some configuration parameters may take
5441 only effect after the next boot (yes, that's just like Windoze :-).
5444 Callback functions for environment variables:
5445 ---------------------------------------------
5447 For some environment variables, the behavior of u-boot needs to change
5448 when their values are changed. This functionality allows functions to
5449 be associated with arbitrary variables. On creation, overwrite, or
5450 deletion, the callback will provide the opportunity for some side
5451 effect to happen or for the change to be rejected.
5453 The callbacks are named and associated with a function using the
5454 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5456 These callbacks are associated with variables in one of two ways. The
5457 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5458 in the board configuration to a string that defines a list of
5459 associations. The list must be in the following format:
5461 entry = variable_name[:callback_name]
5464 If the callback name is not specified, then the callback is deleted.
5465 Spaces are also allowed anywhere in the list.
5467 Callbacks can also be associated by defining the ".callbacks" variable
5468 with the same list format above. Any association in ".callbacks" will
5469 override any association in the static list. You can define
5470 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5471 ".callbacks" environment variable in the default or embedded environment.
5473 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5474 regular expression. This allows multiple variables to be connected to
5475 the same callback without explicitly listing them all out.
5478 Command Line Parsing:
5479 =====================
5481 There are two different command line parsers available with U-Boot:
5482 the old "simple" one, and the much more powerful "hush" shell:
5484 Old, simple command line parser:
5485 --------------------------------
5487 - supports environment variables (through setenv / saveenv commands)
5488 - several commands on one line, separated by ';'
5489 - variable substitution using "... ${name} ..." syntax
5490 - special characters ('$', ';') can be escaped by prefixing with '\',
5492 setenv bootcmd bootm \${address}
5493 - You can also escape text by enclosing in single apostrophes, for example:
5494 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5499 - similar to Bourne shell, with control structures like
5500 if...then...else...fi, for...do...done; while...do...done,
5501 until...do...done, ...
5502 - supports environment ("global") variables (through setenv / saveenv
5503 commands) and local shell variables (through standard shell syntax
5504 "name=value"); only environment variables can be used with "run"
5510 (1) If a command line (or an environment variable executed by a "run"
5511 command) contains several commands separated by semicolon, and
5512 one of these commands fails, then the remaining commands will be
5515 (2) If you execute several variables with one call to run (i. e.
5516 calling run with a list of variables as arguments), any failing
5517 command will cause "run" to terminate, i. e. the remaining
5518 variables are not executed.
5520 Note for Redundant Ethernet Interfaces:
5521 =======================================
5523 Some boards come with redundant Ethernet interfaces; U-Boot supports
5524 such configurations and is capable of automatic selection of a
5525 "working" interface when needed. MAC assignment works as follows:
5527 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5528 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5529 "eth1addr" (=>eth1), "eth2addr", ...
5531 If the network interface stores some valid MAC address (for instance
5532 in SROM), this is used as default address if there is NO correspon-
5533 ding setting in the environment; if the corresponding environment
5534 variable is set, this overrides the settings in the card; that means:
5536 o If the SROM has a valid MAC address, and there is no address in the
5537 environment, the SROM's address is used.
5539 o If there is no valid address in the SROM, and a definition in the
5540 environment exists, then the value from the environment variable is
5543 o If both the SROM and the environment contain a MAC address, and
5544 both addresses are the same, this MAC address is used.
5546 o If both the SROM and the environment contain a MAC address, and the
5547 addresses differ, the value from the environment is used and a
5550 o If neither SROM nor the environment contain a MAC address, an error
5551 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5552 a random, locally-assigned MAC is used.
5554 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5555 will be programmed into hardware as part of the initialization process. This
5556 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5557 The naming convention is as follows:
5558 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5563 U-Boot is capable of booting (and performing other auxiliary operations on)
5564 images in two formats:
5566 New uImage format (FIT)
5567 -----------------------
5569 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5570 to Flattened Device Tree). It allows the use of images with multiple
5571 components (several kernels, ramdisks, etc.), with contents protected by
5572 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5578 Old image format is based on binary files which can be basically anything,
5579 preceded by a special header; see the definitions in include/image.h for
5580 details; basically, the header defines the following image properties:
5582 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5583 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5584 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5585 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5587 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5588 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5589 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5590 * Compression Type (uncompressed, gzip, bzip2)
5596 The header is marked by a special Magic Number, and both the header
5597 and the data portions of the image are secured against corruption by
5604 Although U-Boot should support any OS or standalone application
5605 easily, the main focus has always been on Linux during the design of
5608 U-Boot includes many features that so far have been part of some
5609 special "boot loader" code within the Linux kernel. Also, any
5610 "initrd" images to be used are no longer part of one big Linux image;
5611 instead, kernel and "initrd" are separate images. This implementation
5612 serves several purposes:
5614 - the same features can be used for other OS or standalone
5615 applications (for instance: using compressed images to reduce the
5616 Flash memory footprint)
5618 - it becomes much easier to port new Linux kernel versions because
5619 lots of low-level, hardware dependent stuff are done by U-Boot
5621 - the same Linux kernel image can now be used with different "initrd"
5622 images; of course this also means that different kernel images can
5623 be run with the same "initrd". This makes testing easier (you don't
5624 have to build a new "zImage.initrd" Linux image when you just
5625 change a file in your "initrd"). Also, a field-upgrade of the
5626 software is easier now.
5632 Porting Linux to U-Boot based systems:
5633 ---------------------------------------
5635 U-Boot cannot save you from doing all the necessary modifications to
5636 configure the Linux device drivers for use with your target hardware
5637 (no, we don't intend to provide a full virtual machine interface to
5640 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5642 Just make sure your machine specific header file (for instance
5643 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5644 Information structure as we define in include/asm-<arch>/u-boot.h,
5645 and make sure that your definition of IMAP_ADDR uses the same value
5646 as your U-Boot configuration in CONFIG_SYS_IMMR.
5648 Note that U-Boot now has a driver model, a unified model for drivers.
5649 If you are adding a new driver, plumb it into driver model. If there
5650 is no uclass available, you are encouraged to create one. See
5654 Configuring the Linux kernel:
5655 -----------------------------
5657 No specific requirements for U-Boot. Make sure you have some root
5658 device (initial ramdisk, NFS) for your target system.
5661 Building a Linux Image:
5662 -----------------------
5664 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5665 not used. If you use recent kernel source, a new build target
5666 "uImage" will exist which automatically builds an image usable by
5667 U-Boot. Most older kernels also have support for a "pImage" target,
5668 which was introduced for our predecessor project PPCBoot and uses a
5669 100% compatible format.
5673 make TQM850L_defconfig
5678 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5679 encapsulate a compressed Linux kernel image with header information,
5680 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5682 * build a standard "vmlinux" kernel image (in ELF binary format):
5684 * convert the kernel into a raw binary image:
5686 ${CROSS_COMPILE}-objcopy -O binary \
5687 -R .note -R .comment \
5688 -S vmlinux linux.bin
5690 * compress the binary image:
5694 * package compressed binary image for U-Boot:
5696 mkimage -A ppc -O linux -T kernel -C gzip \
5697 -a 0 -e 0 -n "Linux Kernel Image" \
5698 -d linux.bin.gz uImage
5701 The "mkimage" tool can also be used to create ramdisk images for use
5702 with U-Boot, either separated from the Linux kernel image, or
5703 combined into one file. "mkimage" encapsulates the images with a 64
5704 byte header containing information about target architecture,
5705 operating system, image type, compression method, entry points, time
5706 stamp, CRC32 checksums, etc.
5708 "mkimage" can be called in two ways: to verify existing images and
5709 print the header information, or to build new images.
5711 In the first form (with "-l" option) mkimage lists the information
5712 contained in the header of an existing U-Boot image; this includes
5713 checksum verification:
5715 tools/mkimage -l image
5716 -l ==> list image header information
5718 The second form (with "-d" option) is used to build a U-Boot image
5719 from a "data file" which is used as image payload:
5721 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5722 -n name -d data_file image
5723 -A ==> set architecture to 'arch'
5724 -O ==> set operating system to 'os'
5725 -T ==> set image type to 'type'
5726 -C ==> set compression type 'comp'
5727 -a ==> set load address to 'addr' (hex)
5728 -e ==> set entry point to 'ep' (hex)
5729 -n ==> set image name to 'name'
5730 -d ==> use image data from 'datafile'
5732 Right now, all Linux kernels for PowerPC systems use the same load
5733 address (0x00000000), but the entry point address depends on the
5736 - 2.2.x kernels have the entry point at 0x0000000C,
5737 - 2.3.x and later kernels have the entry point at 0x00000000.
5739 So a typical call to build a U-Boot image would read:
5741 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5742 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5743 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5744 > examples/uImage.TQM850L
5745 Image Name: 2.4.4 kernel for TQM850L
5746 Created: Wed Jul 19 02:34:59 2000
5747 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5748 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5749 Load Address: 0x00000000
5750 Entry Point: 0x00000000
5752 To verify the contents of the image (or check for corruption):
5754 -> tools/mkimage -l examples/uImage.TQM850L
5755 Image Name: 2.4.4 kernel for TQM850L
5756 Created: Wed Jul 19 02:34:59 2000
5757 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5758 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5759 Load Address: 0x00000000
5760 Entry Point: 0x00000000
5762 NOTE: for embedded systems where boot time is critical you can trade
5763 speed for memory and install an UNCOMPRESSED image instead: this
5764 needs more space in Flash, but boots much faster since it does not
5765 need to be uncompressed:
5767 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5768 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5769 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5770 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5771 > examples/uImage.TQM850L-uncompressed
5772 Image Name: 2.4.4 kernel for TQM850L
5773 Created: Wed Jul 19 02:34:59 2000
5774 Image Type: PowerPC Linux Kernel Image (uncompressed)
5775 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5776 Load Address: 0x00000000
5777 Entry Point: 0x00000000
5780 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5781 when your kernel is intended to use an initial ramdisk:
5783 -> tools/mkimage -n 'Simple Ramdisk Image' \
5784 > -A ppc -O linux -T ramdisk -C gzip \
5785 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5786 Image Name: Simple Ramdisk Image
5787 Created: Wed Jan 12 14:01:50 2000
5788 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5789 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5790 Load Address: 0x00000000
5791 Entry Point: 0x00000000
5793 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5794 option performs the converse operation of the mkimage's second form (the "-d"
5795 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5798 tools/dumpimage -i image -T type -p position data_file
5799 -i ==> extract from the 'image' a specific 'data_file'
5800 -T ==> set image type to 'type'
5801 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5804 Installing a Linux Image:
5805 -------------------------
5807 To downloading a U-Boot image over the serial (console) interface,
5808 you must convert the image to S-Record format:
5810 objcopy -I binary -O srec examples/image examples/image.srec
5812 The 'objcopy' does not understand the information in the U-Boot
5813 image header, so the resulting S-Record file will be relative to
5814 address 0x00000000. To load it to a given address, you need to
5815 specify the target address as 'offset' parameter with the 'loads'
5818 Example: install the image to address 0x40100000 (which on the
5819 TQM8xxL is in the first Flash bank):
5821 => erase 40100000 401FFFFF
5827 ## Ready for S-Record download ...
5828 ~>examples/image.srec
5829 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5831 15989 15990 15991 15992
5832 [file transfer complete]
5834 ## Start Addr = 0x00000000
5837 You can check the success of the download using the 'iminfo' command;
5838 this includes a checksum verification so you can be sure no data
5839 corruption happened:
5843 ## Checking Image at 40100000 ...
5844 Image Name: 2.2.13 for initrd on TQM850L
5845 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5846 Data Size: 335725 Bytes = 327 kB = 0 MB
5847 Load Address: 00000000
5848 Entry Point: 0000000c
5849 Verifying Checksum ... OK
5855 The "bootm" command is used to boot an application that is stored in
5856 memory (RAM or Flash). In case of a Linux kernel image, the contents
5857 of the "bootargs" environment variable is passed to the kernel as
5858 parameters. You can check and modify this variable using the
5859 "printenv" and "setenv" commands:
5862 => printenv bootargs
5863 bootargs=root=/dev/ram
5865 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5867 => printenv bootargs
5868 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5871 ## Booting Linux kernel at 40020000 ...
5872 Image Name: 2.2.13 for NFS on TQM850L
5873 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5874 Data Size: 381681 Bytes = 372 kB = 0 MB
5875 Load Address: 00000000
5876 Entry Point: 0000000c
5877 Verifying Checksum ... OK
5878 Uncompressing Kernel Image ... OK
5879 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
5880 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5881 time_init: decrementer frequency = 187500000/60
5882 Calibrating delay loop... 49.77 BogoMIPS
5883 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5886 If you want to boot a Linux kernel with initial RAM disk, you pass
5887 the memory addresses of both the kernel and the initrd image (PPBCOOT
5888 format!) to the "bootm" command:
5890 => imi 40100000 40200000
5892 ## Checking Image at 40100000 ...
5893 Image Name: 2.2.13 for initrd on TQM850L
5894 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5895 Data Size: 335725 Bytes = 327 kB = 0 MB
5896 Load Address: 00000000
5897 Entry Point: 0000000c
5898 Verifying Checksum ... OK
5900 ## Checking Image at 40200000 ...
5901 Image Name: Simple Ramdisk Image
5902 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5903 Data Size: 566530 Bytes = 553 kB = 0 MB
5904 Load Address: 00000000
5905 Entry Point: 00000000
5906 Verifying Checksum ... OK
5908 => bootm 40100000 40200000
5909 ## Booting Linux kernel at 40100000 ...
5910 Image Name: 2.2.13 for initrd on TQM850L
5911 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5912 Data Size: 335725 Bytes = 327 kB = 0 MB
5913 Load Address: 00000000
5914 Entry Point: 0000000c
5915 Verifying Checksum ... OK
5916 Uncompressing Kernel Image ... OK
5917 ## Loading RAMDisk Image at 40200000 ...
5918 Image Name: Simple Ramdisk Image
5919 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5920 Data Size: 566530 Bytes = 553 kB = 0 MB
5921 Load Address: 00000000
5922 Entry Point: 00000000
5923 Verifying Checksum ... OK
5924 Loading Ramdisk ... OK
5925 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
5926 Boot arguments: root=/dev/ram
5927 time_init: decrementer frequency = 187500000/60
5928 Calibrating delay loop... 49.77 BogoMIPS
5930 RAMDISK: Compressed image found at block 0
5931 VFS: Mounted root (ext2 filesystem).
5935 Boot Linux and pass a flat device tree:
5938 First, U-Boot must be compiled with the appropriate defines. See the section
5939 titled "Linux Kernel Interface" above for a more in depth explanation. The
5940 following is an example of how to start a kernel and pass an updated
5946 oft=oftrees/mpc8540ads.dtb
5947 => tftp $oftaddr $oft
5948 Speed: 1000, full duplex
5950 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5951 Filename 'oftrees/mpc8540ads.dtb'.
5952 Load address: 0x300000
5955 Bytes transferred = 4106 (100a hex)
5956 => tftp $loadaddr $bootfile
5957 Speed: 1000, full duplex
5959 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5961 Load address: 0x200000
5962 Loading:############
5964 Bytes transferred = 1029407 (fb51f hex)
5969 => bootm $loadaddr - $oftaddr
5970 ## Booting image at 00200000 ...
5971 Image Name: Linux-2.6.17-dirty
5972 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5973 Data Size: 1029343 Bytes = 1005.2 kB
5974 Load Address: 00000000
5975 Entry Point: 00000000
5976 Verifying Checksum ... OK
5977 Uncompressing Kernel Image ... OK
5978 Booting using flat device tree at 0x300000
5979 Using MPC85xx ADS machine description
5980 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5984 More About U-Boot Image Types:
5985 ------------------------------
5987 U-Boot supports the following image types:
5989 "Standalone Programs" are directly runnable in the environment
5990 provided by U-Boot; it is expected that (if they behave
5991 well) you can continue to work in U-Boot after return from
5992 the Standalone Program.
5993 "OS Kernel Images" are usually images of some Embedded OS which
5994 will take over control completely. Usually these programs
5995 will install their own set of exception handlers, device
5996 drivers, set up the MMU, etc. - this means, that you cannot
5997 expect to re-enter U-Boot except by resetting the CPU.
5998 "RAMDisk Images" are more or less just data blocks, and their
5999 parameters (address, size) are passed to an OS kernel that is
6001 "Multi-File Images" contain several images, typically an OS
6002 (Linux) kernel image and one or more data images like
6003 RAMDisks. This construct is useful for instance when you want
6004 to boot over the network using BOOTP etc., where the boot
6005 server provides just a single image file, but you want to get
6006 for instance an OS kernel and a RAMDisk image.
6008 "Multi-File Images" start with a list of image sizes, each
6009 image size (in bytes) specified by an "uint32_t" in network
6010 byte order. This list is terminated by an "(uint32_t)0".
6011 Immediately after the terminating 0 follow the images, one by
6012 one, all aligned on "uint32_t" boundaries (size rounded up to
6013 a multiple of 4 bytes).
6015 "Firmware Images" are binary images containing firmware (like
6016 U-Boot or FPGA images) which usually will be programmed to
6019 "Script files" are command sequences that will be executed by
6020 U-Boot's command interpreter; this feature is especially
6021 useful when you configure U-Boot to use a real shell (hush)
6022 as command interpreter.
6024 Booting the Linux zImage:
6025 -------------------------
6027 On some platforms, it's possible to boot Linux zImage. This is done
6028 using the "bootz" command. The syntax of "bootz" command is the same
6029 as the syntax of "bootm" command.
6031 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6032 kernel with raw initrd images. The syntax is slightly different, the
6033 address of the initrd must be augmented by it's size, in the following
6034 format: "<initrd addres>:<initrd size>".
6040 One of the features of U-Boot is that you can dynamically load and
6041 run "standalone" applications, which can use some resources of
6042 U-Boot like console I/O functions or interrupt services.
6044 Two simple examples are included with the sources:
6049 'examples/hello_world.c' contains a small "Hello World" Demo
6050 application; it is automatically compiled when you build U-Boot.
6051 It's configured to run at address 0x00040004, so you can play with it
6055 ## Ready for S-Record download ...
6056 ~>examples/hello_world.srec
6057 1 2 3 4 5 6 7 8 9 10 11 ...
6058 [file transfer complete]
6060 ## Start Addr = 0x00040004
6062 => go 40004 Hello World! This is a test.
6063 ## Starting application at 0x00040004 ...
6074 Hit any key to exit ...
6076 ## Application terminated, rc = 0x0
6078 Another example, which demonstrates how to register a CPM interrupt
6079 handler with the U-Boot code, can be found in 'examples/timer.c'.
6080 Here, a CPM timer is set up to generate an interrupt every second.
6081 The interrupt service routine is trivial, just printing a '.'
6082 character, but this is just a demo program. The application can be
6083 controlled by the following keys:
6085 ? - print current values og the CPM Timer registers
6086 b - enable interrupts and start timer
6087 e - stop timer and disable interrupts
6088 q - quit application
6091 ## Ready for S-Record download ...
6092 ~>examples/timer.srec
6093 1 2 3 4 5 6 7 8 9 10 11 ...
6094 [file transfer complete]
6096 ## Start Addr = 0x00040004
6099 ## Starting application at 0x00040004 ...
6102 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6105 [q, b, e, ?] Set interval 1000000 us
6108 [q, b, e, ?] ........
6109 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6112 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6115 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6118 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6120 [q, b, e, ?] ...Stopping timer
6122 [q, b, e, ?] ## Application terminated, rc = 0x0
6128 Over time, many people have reported problems when trying to use the
6129 "minicom" terminal emulation program for serial download. I (wd)
6130 consider minicom to be broken, and recommend not to use it. Under
6131 Unix, I recommend to use C-Kermit for general purpose use (and
6132 especially for kermit binary protocol download ("loadb" command), and
6133 use "cu" for S-Record download ("loads" command). See
6134 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6135 for help with kermit.
6138 Nevertheless, if you absolutely want to use it try adding this
6139 configuration to your "File transfer protocols" section:
6141 Name Program Name U/D FullScr IO-Red. Multi
6142 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6143 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6149 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6150 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6152 Building requires a cross environment; it is known to work on
6153 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6154 need gmake since the Makefiles are not compatible with BSD make).
6155 Note that the cross-powerpc package does not install include files;
6156 attempting to build U-Boot will fail because <machine/ansi.h> is
6157 missing. This file has to be installed and patched manually:
6159 # cd /usr/pkg/cross/powerpc-netbsd/include
6161 # ln -s powerpc machine
6162 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6163 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6165 Native builds *don't* work due to incompatibilities between native
6166 and U-Boot include files.
6168 Booting assumes that (the first part of) the image booted is a
6169 stage-2 loader which in turn loads and then invokes the kernel
6170 proper. Loader sources will eventually appear in the NetBSD source
6171 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6172 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6175 Implementation Internals:
6176 =========================
6178 The following is not intended to be a complete description of every
6179 implementation detail. However, it should help to understand the
6180 inner workings of U-Boot and make it easier to port it to custom
6184 Initial Stack, Global Data:
6185 ---------------------------
6187 The implementation of U-Boot is complicated by the fact that U-Boot
6188 starts running out of ROM (flash memory), usually without access to
6189 system RAM (because the memory controller is not initialized yet).
6190 This means that we don't have writable Data or BSS segments, and BSS
6191 is not initialized as zero. To be able to get a C environment working
6192 at all, we have to allocate at least a minimal stack. Implementation
6193 options for this are defined and restricted by the CPU used: Some CPU
6194 models provide on-chip memory (like the IMMR area on MPC8xx and
6195 MPC826x processors), on others (parts of) the data cache can be
6196 locked as (mis-) used as memory, etc.
6198 Chris Hallinan posted a good summary of these issues to the
6199 U-Boot mailing list:
6201 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6202 From: "Chris Hallinan" <clh@net1plus.com>
6203 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6206 Correct me if I'm wrong, folks, but the way I understand it
6207 is this: Using DCACHE as initial RAM for Stack, etc, does not
6208 require any physical RAM backing up the cache. The cleverness
6209 is that the cache is being used as a temporary supply of
6210 necessary storage before the SDRAM controller is setup. It's
6211 beyond the scope of this list to explain the details, but you
6212 can see how this works by studying the cache architecture and
6213 operation in the architecture and processor-specific manuals.
6215 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6216 is another option for the system designer to use as an
6217 initial stack/RAM area prior to SDRAM being available. Either
6218 option should work for you. Using CS 4 should be fine if your
6219 board designers haven't used it for something that would
6220 cause you grief during the initial boot! It is frequently not
6223 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6224 with your processor/board/system design. The default value
6225 you will find in any recent u-boot distribution in
6226 walnut.h should work for you. I'd set it to a value larger
6227 than your SDRAM module. If you have a 64MB SDRAM module, set
6228 it above 400_0000. Just make sure your board has no resources
6229 that are supposed to respond to that address! That code in
6230 start.S has been around a while and should work as is when
6231 you get the config right.
6236 It is essential to remember this, since it has some impact on the C
6237 code for the initialization procedures:
6239 * Initialized global data (data segment) is read-only. Do not attempt
6242 * Do not use any uninitialized global data (or implicitly initialized
6243 as zero data - BSS segment) at all - this is undefined, initiali-
6244 zation is performed later (when relocating to RAM).
6246 * Stack space is very limited. Avoid big data buffers or things like
6249 Having only the stack as writable memory limits means we cannot use
6250 normal global data to share information between the code. But it
6251 turned out that the implementation of U-Boot can be greatly
6252 simplified by making a global data structure (gd_t) available to all
6253 functions. We could pass a pointer to this data as argument to _all_
6254 functions, but this would bloat the code. Instead we use a feature of
6255 the GCC compiler (Global Register Variables) to share the data: we
6256 place a pointer (gd) to the global data into a register which we
6257 reserve for this purpose.
6259 When choosing a register for such a purpose we are restricted by the
6260 relevant (E)ABI specifications for the current architecture, and by
6261 GCC's implementation.
6263 For PowerPC, the following registers have specific use:
6265 R2: reserved for system use
6266 R3-R4: parameter passing and return values
6267 R5-R10: parameter passing
6268 R13: small data area pointer
6272 (U-Boot also uses R12 as internal GOT pointer. r12
6273 is a volatile register so r12 needs to be reset when
6274 going back and forth between asm and C)
6276 ==> U-Boot will use R2 to hold a pointer to the global data
6278 Note: on PPC, we could use a static initializer (since the
6279 address of the global data structure is known at compile time),
6280 but it turned out that reserving a register results in somewhat
6281 smaller code - although the code savings are not that big (on
6282 average for all boards 752 bytes for the whole U-Boot image,
6283 624 text + 127 data).
6285 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6286 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6288 ==> U-Boot will use P3 to hold a pointer to the global data
6290 On ARM, the following registers are used:
6292 R0: function argument word/integer result
6293 R1-R3: function argument word
6294 R9: platform specific
6295 R10: stack limit (used only if stack checking is enabled)
6296 R11: argument (frame) pointer
6297 R12: temporary workspace
6300 R15: program counter
6302 ==> U-Boot will use R9 to hold a pointer to the global data
6304 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6306 On Nios II, the ABI is documented here:
6307 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6309 ==> U-Boot will use gp to hold a pointer to the global data
6311 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6312 to access small data sections, so gp is free.
6314 On NDS32, the following registers are used:
6316 R0-R1: argument/return
6318 R15: temporary register for assembler
6319 R16: trampoline register
6320 R28: frame pointer (FP)
6321 R29: global pointer (GP)
6322 R30: link register (LP)
6323 R31: stack pointer (SP)
6324 PC: program counter (PC)
6326 ==> U-Boot will use R10 to hold a pointer to the global data
6328 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6329 or current versions of GCC may "optimize" the code too much.
6334 U-Boot runs in system state and uses physical addresses, i.e. the
6335 MMU is not used either for address mapping nor for memory protection.
6337 The available memory is mapped to fixed addresses using the memory
6338 controller. In this process, a contiguous block is formed for each
6339 memory type (Flash, SDRAM, SRAM), even when it consists of several
6340 physical memory banks.
6342 U-Boot is installed in the first 128 kB of the first Flash bank (on
6343 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6344 booting and sizing and initializing DRAM, the code relocates itself
6345 to the upper end of DRAM. Immediately below the U-Boot code some
6346 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6347 configuration setting]. Below that, a structure with global Board
6348 Info data is placed, followed by the stack (growing downward).
6350 Additionally, some exception handler code is copied to the low 8 kB
6351 of DRAM (0x00000000 ... 0x00001FFF).
6353 So a typical memory configuration with 16 MB of DRAM could look like
6356 0x0000 0000 Exception Vector code
6359 0x0000 2000 Free for Application Use
6365 0x00FB FF20 Monitor Stack (Growing downward)
6366 0x00FB FFAC Board Info Data and permanent copy of global data
6367 0x00FC 0000 Malloc Arena
6370 0x00FE 0000 RAM Copy of Monitor Code
6371 ... eventually: LCD or video framebuffer
6372 ... eventually: pRAM (Protected RAM - unchanged by reset)
6373 0x00FF FFFF [End of RAM]
6376 System Initialization:
6377 ----------------------
6379 In the reset configuration, U-Boot starts at the reset entry point
6380 (on most PowerPC systems at address 0x00000100). Because of the reset
6381 configuration for CS0# this is a mirror of the on board Flash memory.
6382 To be able to re-map memory U-Boot then jumps to its link address.
6383 To be able to implement the initialization code in C, a (small!)
6384 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6385 which provide such a feature like MPC8xx or MPC8260), or in a locked
6386 part of the data cache. After that, U-Boot initializes the CPU core,
6387 the caches and the SIU.
6389 Next, all (potentially) available memory banks are mapped using a
6390 preliminary mapping. For example, we put them on 512 MB boundaries
6391 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6392 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6393 programmed for SDRAM access. Using the temporary configuration, a
6394 simple memory test is run that determines the size of the SDRAM
6397 When there is more than one SDRAM bank, and the banks are of
6398 different size, the largest is mapped first. For equal size, the first
6399 bank (CS2#) is mapped first. The first mapping is always for address
6400 0x00000000, with any additional banks following immediately to create
6401 contiguous memory starting from 0.
6403 Then, the monitor installs itself at the upper end of the SDRAM area
6404 and allocates memory for use by malloc() and for the global Board
6405 Info data; also, the exception vector code is copied to the low RAM
6406 pages, and the final stack is set up.
6408 Only after this relocation will you have a "normal" C environment;
6409 until that you are restricted in several ways, mostly because you are
6410 running from ROM, and because the code will have to be relocated to a
6414 U-Boot Porting Guide:
6415 ----------------------
6417 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6421 int main(int argc, char *argv[])
6423 sighandler_t no_more_time;
6425 signal(SIGALRM, no_more_time);
6426 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6428 if (available_money > available_manpower) {
6429 Pay consultant to port U-Boot;
6433 Download latest U-Boot source;
6435 Subscribe to u-boot mailing list;
6438 email("Hi, I am new to U-Boot, how do I get started?");
6441 Read the README file in the top level directory;
6442 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6443 Read applicable doc/*.README;
6444 Read the source, Luke;
6445 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6448 if (available_money > toLocalCurrency ($2500))
6451 Add a lot of aggravation and time;
6453 if (a similar board exists) { /* hopefully... */
6454 cp -a board/<similar> board/<myboard>
6455 cp include/configs/<similar>.h include/configs/<myboard>.h
6457 Create your own board support subdirectory;
6458 Create your own board include/configs/<myboard>.h file;
6460 Edit new board/<myboard> files
6461 Edit new include/configs/<myboard>.h
6466 Add / modify source code;
6470 email("Hi, I am having problems...");
6472 Send patch file to the U-Boot email list;
6473 if (reasonable critiques)
6474 Incorporate improvements from email list code review;
6476 Defend code as written;
6482 void no_more_time (int sig)
6491 All contributions to U-Boot should conform to the Linux kernel
6492 coding style; see the file "Documentation/CodingStyle" and the script
6493 "scripts/Lindent" in your Linux kernel source directory.
6495 Source files originating from a different project (for example the
6496 MTD subsystem) are generally exempt from these guidelines and are not
6497 reformatted to ease subsequent migration to newer versions of those
6500 Please note that U-Boot is implemented in C (and to some small parts in
6501 Assembler); no C++ is used, so please do not use C++ style comments (//)
6504 Please also stick to the following formatting rules:
6505 - remove any trailing white space
6506 - use TAB characters for indentation and vertical alignment, not spaces
6507 - make sure NOT to use DOS '\r\n' line feeds
6508 - do not add more than 2 consecutive empty lines to source files
6509 - do not add trailing empty lines to source files
6511 Submissions which do not conform to the standards may be returned
6512 with a request to reformat the changes.
6518 Since the number of patches for U-Boot is growing, we need to
6519 establish some rules. Submissions which do not conform to these rules
6520 may be rejected, even when they contain important and valuable stuff.
6522 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6524 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6525 see http://lists.denx.de/mailman/listinfo/u-boot
6527 When you send a patch, please include the following information with
6530 * For bug fixes: a description of the bug and how your patch fixes
6531 this bug. Please try to include a way of demonstrating that the
6532 patch actually fixes something.
6534 * For new features: a description of the feature and your
6537 * A CHANGELOG entry as plaintext (separate from the patch)
6539 * For major contributions, add a MAINTAINERS file with your
6540 information and associated file and directory references.
6542 * When you add support for a new board, don't forget to add a
6543 maintainer e-mail address to the boards.cfg file, too.
6545 * If your patch adds new configuration options, don't forget to
6546 document these in the README file.
6548 * The patch itself. If you are using git (which is *strongly*
6549 recommended) you can easily generate the patch using the
6550 "git format-patch". If you then use "git send-email" to send it to
6551 the U-Boot mailing list, you will avoid most of the common problems
6552 with some other mail clients.
6554 If you cannot use git, use "diff -purN OLD NEW". If your version of
6555 diff does not support these options, then get the latest version of
6558 The current directory when running this command shall be the parent
6559 directory of the U-Boot source tree (i. e. please make sure that
6560 your patch includes sufficient directory information for the
6563 We prefer patches as plain text. MIME attachments are discouraged,
6564 and compressed attachments must not be used.
6566 * If one logical set of modifications affects or creates several
6567 files, all these changes shall be submitted in a SINGLE patch file.
6569 * Changesets that contain different, unrelated modifications shall be
6570 submitted as SEPARATE patches, one patch per changeset.
6575 * Before sending the patch, run the MAKEALL script on your patched
6576 source tree and make sure that no errors or warnings are reported
6577 for any of the boards.
6579 * Keep your modifications to the necessary minimum: A patch
6580 containing several unrelated changes or arbitrary reformats will be
6581 returned with a request to re-formatting / split it.
6583 * If you modify existing code, make sure that your new code does not
6584 add to the memory footprint of the code ;-) Small is beautiful!
6585 When adding new features, these should compile conditionally only
6586 (using #ifdef), and the resulting code with the new feature
6587 disabled must not need more memory than the old code without your
6590 * Remember that there is a size limit of 100 kB per message on the
6591 u-boot mailing list. Bigger patches will be moderated. If they are
6592 reasonable and not too big, they will be acknowledged. But patches
6593 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob