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_ELF * bootelf, bootvx
1007 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1008 CONFIG_CMD_ENV_FLAGS * display details about env flags
1009 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1010 CONFIG_CMD_EXPORTENV * export the environment
1011 CONFIG_CMD_EXT2 * ext2 command support
1012 CONFIG_CMD_EXT4 * ext4 command support
1013 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1014 that work for multiple fs types
1015 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1016 CONFIG_CMD_SAVEENV saveenv
1017 CONFIG_CMD_FDC * Floppy Disk Support
1018 CONFIG_CMD_FAT * FAT command support
1019 CONFIG_CMD_FLASH flinfo, erase, protect
1020 CONFIG_CMD_FPGA FPGA device initialization support
1021 CONFIG_CMD_FUSE * Device fuse support
1022 CONFIG_CMD_GETTIME * Get time since boot
1023 CONFIG_CMD_GO * the 'go' command (exec code)
1024 CONFIG_CMD_GREPENV * search environment
1025 CONFIG_CMD_HASH * calculate hash / digest
1026 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
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_CMD_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 - Regular expression support:
1114 If this variable is defined, U-Boot is linked against
1115 the SLRE (Super Light Regular Expression) library,
1116 which adds regex support to some commands, as for
1117 example "env grep" and "setexpr".
1121 If this variable is defined, U-Boot will use a device tree
1122 to configure its devices, instead of relying on statically
1123 compiled #defines in the board file. This option is
1124 experimental and only available on a few boards. The device
1125 tree is available in the global data as gd->fdt_blob.
1127 U-Boot needs to get its device tree from somewhere. This can
1128 be done using one of the two options below:
1131 If this variable is defined, U-Boot will embed a device tree
1132 binary in its image. This device tree file should be in the
1133 board directory and called <soc>-<board>.dts. The binary file
1134 is then picked up in board_init_f() and made available through
1135 the global data structure as gd->blob.
1138 If this variable is defined, U-Boot will build a device tree
1139 binary. It will be called u-boot.dtb. Architecture-specific
1140 code will locate it at run-time. Generally this works by:
1142 cat u-boot.bin u-boot.dtb >image.bin
1144 and in fact, U-Boot does this for you, creating a file called
1145 u-boot-dtb.bin which is useful in the common case. You can
1146 still use the individual files if you need something more
1151 If this variable is defined, it enables watchdog
1152 support for the SoC. There must be support in the SoC
1153 specific code for a watchdog. For the 8xx and 8260
1154 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1155 register. When supported for a specific SoC is
1156 available, then no further board specific code should
1157 be needed to use it.
1160 When using a watchdog circuitry external to the used
1161 SoC, then define this variable and provide board
1162 specific code for the "hw_watchdog_reset" function.
1164 CONFIG_AT91_HW_WDT_TIMEOUT
1165 specify the timeout in seconds. default 2 seconds.
1168 CONFIG_VERSION_VARIABLE
1169 If this variable is defined, an environment variable
1170 named "ver" is created by U-Boot showing the U-Boot
1171 version as printed by the "version" command.
1172 Any change to this variable will be reverted at the
1177 When CONFIG_CMD_DATE is selected, the type of the RTC
1178 has to be selected, too. Define exactly one of the
1181 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1182 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1183 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1184 CONFIG_RTC_MC146818 - use MC146818 RTC
1185 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1186 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1187 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1188 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1189 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1190 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1191 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1192 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1193 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1196 Note that if the RTC uses I2C, then the I2C interface
1197 must also be configured. See I2C Support, below.
1200 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1202 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1203 chip-ngpio pairs that tell the PCA953X driver the number of
1204 pins supported by a particular chip.
1206 Note that if the GPIO device uses I2C, then the I2C interface
1207 must also be configured. See I2C Support, below.
1210 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1211 accesses and can checksum them or write a list of them out
1212 to memory. See the 'iotrace' command for details. This is
1213 useful for testing device drivers since it can confirm that
1214 the driver behaves the same way before and after a code
1215 change. Currently this is supported on sandbox and arm. To
1216 add support for your architecture, add '#include <iotrace.h>'
1217 to the bottom of arch/<arch>/include/asm/io.h and test.
1219 Example output from the 'iotrace stats' command is below.
1220 Note that if the trace buffer is exhausted, the checksum will
1221 still continue to operate.
1224 Start: 10000000 (buffer start address)
1225 Size: 00010000 (buffer size)
1226 Offset: 00000120 (current buffer offset)
1227 Output: 10000120 (start + offset)
1228 Count: 00000018 (number of trace records)
1229 CRC32: 9526fb66 (CRC32 of all trace records)
1231 - Timestamp Support:
1233 When CONFIG_TIMESTAMP is selected, the timestamp
1234 (date and time) of an image is printed by image
1235 commands like bootm or iminfo. This option is
1236 automatically enabled when you select CONFIG_CMD_DATE .
1238 - Partition Labels (disklabels) Supported:
1239 Zero or more of the following:
1240 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1241 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1242 Intel architecture, USB sticks, etc.
1243 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1244 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1245 bootloader. Note 2TB partition limit; see
1247 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1249 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1250 CONFIG_CMD_SCSI) you must configure support for at
1251 least one non-MTD partition type as well.
1254 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1255 board configurations files but used nowhere!
1257 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1258 be performed by calling the function
1259 ide_set_reset(int reset)
1260 which has to be defined in a board specific file
1265 Set this to enable ATAPI support.
1270 Set this to enable support for disks larger than 137GB
1271 Also look at CONFIG_SYS_64BIT_LBA.
1272 Whithout these , LBA48 support uses 32bit variables and will 'only'
1273 support disks up to 2.1TB.
1275 CONFIG_SYS_64BIT_LBA:
1276 When enabled, makes the IDE subsystem use 64bit sector addresses.
1280 At the moment only there is only support for the
1281 SYM53C8XX SCSI controller; define
1282 CONFIG_SCSI_SYM53C8XX to enable it.
1284 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1285 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1286 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1287 maximum numbers of LUNs, SCSI ID's and target
1289 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1291 The environment variable 'scsidevs' is set to the number of
1292 SCSI devices found during the last scan.
1294 - NETWORK Support (PCI):
1296 Support for Intel 8254x/8257x gigabit chips.
1299 Utility code for direct access to the SPI bus on Intel 8257x.
1300 This does not do anything useful unless you set at least one
1301 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1303 CONFIG_E1000_SPI_GENERIC
1304 Allow generic access to the SPI bus on the Intel 8257x, for
1305 example with the "sspi" command.
1308 Management command for E1000 devices. When used on devices
1309 with SPI support you can reprogram the EEPROM from U-Boot.
1312 Support for Intel 82557/82559/82559ER chips.
1313 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1314 write routine for first time initialisation.
1317 Support for Digital 2114x chips.
1318 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1319 modem chip initialisation (KS8761/QS6611).
1322 Support for National dp83815 chips.
1325 Support for National dp8382[01] gigabit chips.
1327 - NETWORK Support (other):
1329 CONFIG_DRIVER_AT91EMAC
1330 Support for AT91RM9200 EMAC.
1333 Define this to use reduced MII inteface
1335 CONFIG_DRIVER_AT91EMAC_QUIET
1336 If this defined, the driver is quiet.
1337 The driver doen't show link status messages.
1339 CONFIG_CALXEDA_XGMAC
1340 Support for the Calxeda XGMAC device
1343 Support for SMSC's LAN91C96 chips.
1345 CONFIG_LAN91C96_BASE
1346 Define this to hold the physical address
1347 of the LAN91C96's I/O space
1349 CONFIG_LAN91C96_USE_32_BIT
1350 Define this to enable 32 bit addressing
1353 Support for SMSC's LAN91C111 chip
1355 CONFIG_SMC91111_BASE
1356 Define this to hold the physical address
1357 of the device (I/O space)
1359 CONFIG_SMC_USE_32_BIT
1360 Define this if data bus is 32 bits
1362 CONFIG_SMC_USE_IOFUNCS
1363 Define this to use i/o functions instead of macros
1364 (some hardware wont work with macros)
1366 CONFIG_DRIVER_TI_EMAC
1367 Support for davinci emac
1369 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1370 Define this if you have more then 3 PHYs.
1373 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1375 CONFIG_FTGMAC100_EGIGA
1376 Define this to use GE link update with gigabit PHY.
1377 Define this if FTGMAC100 is connected to gigabit PHY.
1378 If your system has 10/100 PHY only, it might not occur
1379 wrong behavior. Because PHY usually return timeout or
1380 useless data when polling gigabit status and gigabit
1381 control registers. This behavior won't affect the
1382 correctnessof 10/100 link speed update.
1385 Support for SMSC's LAN911x and LAN921x chips
1388 Define this to hold the physical address
1389 of the device (I/O space)
1391 CONFIG_SMC911X_32_BIT
1392 Define this if data bus is 32 bits
1394 CONFIG_SMC911X_16_BIT
1395 Define this if data bus is 16 bits. If your processor
1396 automatically converts one 32 bit word to two 16 bit
1397 words you may also try CONFIG_SMC911X_32_BIT.
1400 Support for Renesas on-chip Ethernet controller
1402 CONFIG_SH_ETHER_USE_PORT
1403 Define the number of ports to be used
1405 CONFIG_SH_ETHER_PHY_ADDR
1406 Define the ETH PHY's address
1408 CONFIG_SH_ETHER_CACHE_WRITEBACK
1409 If this option is set, the driver enables cache flush.
1413 Support for PWM modul on the imx6.
1417 Support TPM devices.
1419 CONFIG_TPM_TIS_INFINEON
1420 Support for Infineon i2c bus TPM devices. Only one device
1421 per system is supported at this time.
1423 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1424 Define the burst count bytes upper limit
1426 CONFIG_TPM_ATMEL_TWI
1427 Support for Atmel TWI TPM device. Requires I2C support.
1430 Support for generic parallel port TPM devices. Only one device
1431 per system is supported at this time.
1433 CONFIG_TPM_TIS_BASE_ADDRESS
1434 Base address where the generic TPM device is mapped
1435 to. Contemporary x86 systems usually map it at
1439 Add tpm monitor functions.
1440 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1441 provides monitor access to authorized functions.
1444 Define this to enable the TPM support library which provides
1445 functional interfaces to some TPM commands.
1446 Requires support for a TPM device.
1448 CONFIG_TPM_AUTH_SESSIONS
1449 Define this to enable authorized functions in the TPM library.
1450 Requires CONFIG_TPM and CONFIG_SHA1.
1453 At the moment only the UHCI host controller is
1454 supported (PIP405, MIP405, MPC5200); define
1455 CONFIG_USB_UHCI to enable it.
1456 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1457 and define CONFIG_USB_STORAGE to enable the USB
1460 Supported are USB Keyboards and USB Floppy drives
1462 MPC5200 USB requires additional defines:
1464 for 528 MHz Clock: 0x0001bbbb
1468 for differential drivers: 0x00001000
1469 for single ended drivers: 0x00005000
1470 for differential drivers on PSC3: 0x00000100
1471 for single ended drivers on PSC3: 0x00004100
1472 CONFIG_SYS_USB_EVENT_POLL
1473 May be defined to allow interrupt polling
1474 instead of using asynchronous interrupts
1476 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1477 txfilltuning field in the EHCI controller on reset.
1479 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1480 HW module registers.
1483 Define the below if you wish to use the USB console.
1484 Once firmware is rebuilt from a serial console issue the
1485 command "setenv stdin usbtty; setenv stdout usbtty" and
1486 attach your USB cable. The Unix command "dmesg" should print
1487 it has found a new device. The environment variable usbtty
1488 can be set to gserial or cdc_acm to enable your device to
1489 appear to a USB host as a Linux gserial device or a
1490 Common Device Class Abstract Control Model serial device.
1491 If you select usbtty = gserial you should be able to enumerate
1493 # modprobe usbserial vendor=0xVendorID product=0xProductID
1494 else if using cdc_acm, simply setting the environment
1495 variable usbtty to be cdc_acm should suffice. The following
1496 might be defined in YourBoardName.h
1499 Define this to build a UDC device
1502 Define this to have a tty type of device available to
1503 talk to the UDC device
1506 Define this to enable the high speed support for usb
1507 device and usbtty. If this feature is enabled, a routine
1508 int is_usbd_high_speed(void)
1509 also needs to be defined by the driver to dynamically poll
1510 whether the enumeration has succeded at high speed or full
1513 CONFIG_SYS_CONSOLE_IS_IN_ENV
1514 Define this if you want stdin, stdout &/or stderr to
1518 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1519 Derive USB clock from external clock "blah"
1520 - CONFIG_SYS_USB_EXTC_CLK 0x02
1522 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1523 Derive USB clock from brgclk
1524 - CONFIG_SYS_USB_BRG_CLK 0x04
1526 If you have a USB-IF assigned VendorID then you may wish to
1527 define your own vendor specific values either in BoardName.h
1528 or directly in usbd_vendor_info.h. If you don't define
1529 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1530 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1531 should pretend to be a Linux device to it's target host.
1533 CONFIG_USBD_MANUFACTURER
1534 Define this string as the name of your company for
1535 - CONFIG_USBD_MANUFACTURER "my company"
1537 CONFIG_USBD_PRODUCT_NAME
1538 Define this string as the name of your product
1539 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1541 CONFIG_USBD_VENDORID
1542 Define this as your assigned Vendor ID from the USB
1543 Implementors Forum. This *must* be a genuine Vendor ID
1544 to avoid polluting the USB namespace.
1545 - CONFIG_USBD_VENDORID 0xFFFF
1547 CONFIG_USBD_PRODUCTID
1548 Define this as the unique Product ID
1550 - CONFIG_USBD_PRODUCTID 0xFFFF
1552 - ULPI Layer Support:
1553 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1554 the generic ULPI layer. The generic layer accesses the ULPI PHY
1555 via the platform viewport, so you need both the genric layer and
1556 the viewport enabled. Currently only Chipidea/ARC based
1557 viewport is supported.
1558 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1559 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1560 If your ULPI phy needs a different reference clock than the
1561 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1562 the appropriate value in Hz.
1565 The MMC controller on the Intel PXA is supported. To
1566 enable this define CONFIG_MMC. The MMC can be
1567 accessed from the boot prompt by mapping the device
1568 to physical memory similar to flash. Command line is
1569 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1570 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1573 Support for Renesas on-chip MMCIF controller
1575 CONFIG_SH_MMCIF_ADDR
1576 Define the base address of MMCIF registers
1579 Define the clock frequency for MMCIF
1582 Enable the generic MMC driver
1584 CONFIG_SUPPORT_EMMC_BOOT
1585 Enable some additional features of the eMMC boot partitions.
1587 CONFIG_SUPPORT_EMMC_RPMB
1588 Enable the commands for reading, writing and programming the
1589 key for the Replay Protection Memory Block partition in eMMC.
1591 - USB Device Firmware Update (DFU) class support:
1592 CONFIG_USB_FUNCTION_DFU
1593 This enables the USB portion of the DFU USB class
1596 This enables the command "dfu" which is used to have
1597 U-Boot create a DFU class device via USB. This command
1598 requires that the "dfu_alt_info" environment variable be
1599 set and define the alt settings to expose to the host.
1602 This enables support for exposing (e)MMC devices via DFU.
1605 This enables support for exposing NAND devices via DFU.
1608 This enables support for exposing RAM via DFU.
1609 Note: DFU spec refer to non-volatile memory usage, but
1610 allow usages beyond the scope of spec - here RAM usage,
1611 one that would help mostly the developer.
1613 CONFIG_SYS_DFU_DATA_BUF_SIZE
1614 Dfu transfer uses a buffer before writing data to the
1615 raw storage device. Make the size (in bytes) of this buffer
1616 configurable. The size of this buffer is also configurable
1617 through the "dfu_bufsiz" environment variable.
1619 CONFIG_SYS_DFU_MAX_FILE_SIZE
1620 When updating files rather than the raw storage device,
1621 we use a static buffer to copy the file into and then write
1622 the buffer once we've been given the whole file. Define
1623 this to the maximum filesize (in bytes) for the buffer.
1624 Default is 4 MiB if undefined.
1626 DFU_DEFAULT_POLL_TIMEOUT
1627 Poll timeout [ms], is the timeout a device can send to the
1628 host. The host must wait for this timeout before sending
1629 a subsequent DFU_GET_STATUS request to the device.
1631 DFU_MANIFEST_POLL_TIMEOUT
1632 Poll timeout [ms], which the device sends to the host when
1633 entering dfuMANIFEST state. Host waits this timeout, before
1634 sending again an USB request to the device.
1636 - USB Device Android Fastboot support:
1637 CONFIG_USB_FUNCTION_FASTBOOT
1638 This enables the USB part of the fastboot gadget
1641 This enables the command "fastboot" which enables the Android
1642 fastboot mode for the platform's USB device. Fastboot is a USB
1643 protocol for downloading images, flashing and device control
1644 used on Android devices.
1645 See doc/README.android-fastboot for more information.
1647 CONFIG_ANDROID_BOOT_IMAGE
1648 This enables support for booting images which use the Android
1649 image format header.
1651 CONFIG_FASTBOOT_BUF_ADDR
1652 The fastboot protocol requires a large memory buffer for
1653 downloads. Define this to the starting RAM address to use for
1656 CONFIG_FASTBOOT_BUF_SIZE
1657 The fastboot protocol requires a large memory buffer for
1658 downloads. This buffer should be as large as possible for a
1659 platform. Define this to the size available RAM for fastboot.
1661 CONFIG_FASTBOOT_FLASH
1662 The fastboot protocol includes a "flash" command for writing
1663 the downloaded image to a non-volatile storage device. Define
1664 this to enable the "fastboot flash" command.
1666 CONFIG_FASTBOOT_FLASH_MMC_DEV
1667 The fastboot "flash" command requires additional information
1668 regarding the non-volatile storage device. Define this to
1669 the eMMC device that fastboot should use to store the image.
1671 CONFIG_FASTBOOT_GPT_NAME
1672 The fastboot "flash" command supports writing the downloaded
1673 image to the Protective MBR and the Primary GUID Partition
1674 Table. (Additionally, this downloaded image is post-processed
1675 to generate and write the Backup GUID Partition Table.)
1676 This occurs when the specified "partition name" on the
1677 "fastboot flash" command line matches this value.
1678 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1680 - Journaling Flash filesystem support:
1681 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1682 CONFIG_JFFS2_NAND_DEV
1683 Define these for a default partition on a NAND device
1685 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1686 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1687 Define these for a default partition on a NOR device
1689 CONFIG_SYS_JFFS_CUSTOM_PART
1690 Define this to create an own partition. You have to provide a
1691 function struct part_info* jffs2_part_info(int part_num)
1693 If you define only one JFFS2 partition you may also want to
1694 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1695 to disable the command chpart. This is the default when you
1696 have not defined a custom partition
1698 - FAT(File Allocation Table) filesystem write function support:
1701 Define this to enable support for saving memory data as a
1702 file in FAT formatted partition.
1704 This will also enable the command "fatwrite" enabling the
1705 user to write files to FAT.
1707 CBFS (Coreboot Filesystem) support
1710 Define this to enable support for reading from a Coreboot
1711 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1714 - FAT(File Allocation Table) filesystem cluster size:
1715 CONFIG_FS_FAT_MAX_CLUSTSIZE
1717 Define the max cluster size for fat operations else
1718 a default value of 65536 will be defined.
1721 See Kconfig help for available keyboard drivers.
1725 Define this to enable a custom keyboard support.
1726 This simply calls drv_keyboard_init() which must be
1727 defined in your board-specific files. This option is deprecated
1728 and is only used by novena. For new boards, use driver model
1734 Define this to enable video support (for output to
1737 CONFIG_VIDEO_CT69000
1739 Enable Chips & Technologies 69000 Video chip
1741 CONFIG_VIDEO_SMI_LYNXEM
1742 Enable Silicon Motion SMI 712/710/810 Video chip. The
1743 video output is selected via environment 'videoout'
1744 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1747 For the CT69000 and SMI_LYNXEM drivers, videomode is
1748 selected via environment 'videomode'. Two different ways
1750 - "videomode=num" 'num' is a standard LiLo mode numbers.
1751 Following standard modes are supported (* is default):
1753 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1754 -------------+---------------------------------------------
1755 8 bits | 0x301* 0x303 0x305 0x161 0x307
1756 15 bits | 0x310 0x313 0x316 0x162 0x319
1757 16 bits | 0x311 0x314 0x317 0x163 0x31A
1758 24 bits | 0x312 0x315 0x318 ? 0x31B
1759 -------------+---------------------------------------------
1760 (i.e. setenv videomode 317; saveenv; reset;)
1762 - "videomode=bootargs" all the video parameters are parsed
1763 from the bootargs. (See drivers/video/videomodes.c)
1766 CONFIG_VIDEO_SED13806
1767 Enable Epson SED13806 driver. This driver supports 8bpp
1768 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1769 or CONFIG_VIDEO_SED13806_16BPP
1772 Enable the Freescale DIU video driver. Reference boards for
1773 SOCs that have a DIU should define this macro to enable DIU
1774 support, and should also define these other macros:
1780 CONFIG_VIDEO_SW_CURSOR
1781 CONFIG_VGA_AS_SINGLE_DEVICE
1783 CONFIG_VIDEO_BMP_LOGO
1785 The DIU driver will look for the 'video-mode' environment
1786 variable, and if defined, enable the DIU as a console during
1787 boot. See the documentation file README.video for a
1788 description of this variable.
1790 - LCD Support: CONFIG_LCD
1792 Define this to enable LCD support (for output to LCD
1793 display); also select one of the supported displays
1794 by defining one of these:
1798 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1800 CONFIG_NEC_NL6448AC33:
1802 NEC NL6448AC33-18. Active, color, single scan.
1804 CONFIG_NEC_NL6448BC20
1806 NEC NL6448BC20-08. 6.5", 640x480.
1807 Active, color, single scan.
1809 CONFIG_NEC_NL6448BC33_54
1811 NEC NL6448BC33-54. 10.4", 640x480.
1812 Active, color, single scan.
1816 Sharp 320x240. Active, color, single scan.
1817 It isn't 16x9, and I am not sure what it is.
1819 CONFIG_SHARP_LQ64D341
1821 Sharp LQ64D341 display, 640x480.
1822 Active, color, single scan.
1826 HLD1045 display, 640x480.
1827 Active, color, single scan.
1831 Optrex CBL50840-2 NF-FW 99 22 M5
1833 Hitachi LMG6912RPFC-00T
1837 320x240. Black & white.
1839 Normally display is black on white background; define
1840 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1842 CONFIG_LCD_ALIGNMENT
1844 Normally the LCD is page-aligned (typically 4KB). If this is
1845 defined then the LCD will be aligned to this value instead.
1846 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1847 here, since it is cheaper to change data cache settings on
1848 a per-section basis.
1850 CONFIG_CONSOLE_SCROLL_LINES
1852 When the console need to be scrolled, this is the number of
1853 lines to scroll by. It defaults to 1. Increasing this makes
1854 the console jump but can help speed up operation when scrolling
1859 Sometimes, for example if the display is mounted in portrait
1860 mode or even if it's mounted landscape but rotated by 180degree,
1861 we need to rotate our content of the display relative to the
1862 framebuffer, so that user can read the messages which are
1864 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1865 initialized with a given rotation from "vl_rot" out of
1866 "vidinfo_t" which is provided by the board specific code.
1867 The value for vl_rot is coded as following (matching to
1868 fbcon=rotate:<n> linux-kernel commandline):
1869 0 = no rotation respectively 0 degree
1870 1 = 90 degree rotation
1871 2 = 180 degree rotation
1872 3 = 270 degree rotation
1874 If CONFIG_LCD_ROTATION is not defined, the console will be
1875 initialized with 0degree rotation.
1879 Support drawing of RLE8-compressed bitmaps on the LCD.
1883 Enables an 'i2c edid' command which can read EDID
1884 information over I2C from an attached LCD display.
1886 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1888 If this option is set, the environment is checked for
1889 a variable "splashimage". If found, the usual display
1890 of logo, copyright and system information on the LCD
1891 is suppressed and the BMP image at the address
1892 specified in "splashimage" is loaded instead. The
1893 console is redirected to the "nulldev", too. This
1894 allows for a "silent" boot where a splash screen is
1895 loaded very quickly after power-on.
1897 CONFIG_SPLASHIMAGE_GUARD
1899 If this option is set, then U-Boot will prevent the environment
1900 variable "splashimage" from being set to a problematic address
1901 (see README.displaying-bmps).
1902 This option is useful for targets where, due to alignment
1903 restrictions, an improperly aligned BMP image will cause a data
1904 abort. If you think you will not have problems with unaligned
1905 accesses (for example because your toolchain prevents them)
1906 there is no need to set this option.
1908 CONFIG_SPLASH_SCREEN_ALIGN
1910 If this option is set the splash image can be freely positioned
1911 on the screen. Environment variable "splashpos" specifies the
1912 position as "x,y". If a positive number is given it is used as
1913 number of pixel from left/top. If a negative number is given it
1914 is used as number of pixel from right/bottom. You can also
1915 specify 'm' for centering the image.
1918 setenv splashpos m,m
1919 => image at center of screen
1921 setenv splashpos 30,20
1922 => image at x = 30 and y = 20
1924 setenv splashpos -10,m
1925 => vertically centered image
1926 at x = dspWidth - bmpWidth - 9
1928 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1930 If this option is set, additionally to standard BMP
1931 images, gzipped BMP images can be displayed via the
1932 splashscreen support or the bmp command.
1934 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1936 If this option is set, 8-bit RLE compressed BMP images
1937 can be displayed via the splashscreen support or the
1940 - Do compressing for memory range:
1943 If this option is set, it would use zlib deflate method
1944 to compress the specified memory at its best effort.
1946 - Compression support:
1949 Enabled by default to support gzip compressed images.
1953 If this option is set, support for bzip2 compressed
1954 images is included. If not, only uncompressed and gzip
1955 compressed images are supported.
1957 NOTE: the bzip2 algorithm requires a lot of RAM, so
1958 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1963 If this option is set, support for lzma compressed
1966 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1967 requires an amount of dynamic memory that is given by the
1970 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1972 Where lc and lp stand for, respectively, Literal context bits
1973 and Literal pos bits.
1975 This value is upper-bounded by 14MB in the worst case. Anyway,
1976 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1977 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1978 a very small buffer.
1980 Use the lzmainfo tool to determinate the lc and lp values and
1981 then calculate the amount of needed dynamic memory (ensuring
1982 the appropriate CONFIG_SYS_MALLOC_LEN value).
1986 If this option is set, support for LZO compressed images
1992 The address of PHY on MII bus.
1994 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1996 The clock frequency of the MII bus
2000 If this option is set, support for speed/duplex
2001 detection of gigabit PHY is included.
2003 CONFIG_PHY_RESET_DELAY
2005 Some PHY like Intel LXT971A need extra delay after
2006 reset before any MII register access is possible.
2007 For such PHY, set this option to the usec delay
2008 required. (minimum 300usec for LXT971A)
2010 CONFIG_PHY_CMD_DELAY (ppc4xx)
2012 Some PHY like Intel LXT971A need extra delay after
2013 command issued before MII status register can be read
2018 Define a default value for the IP address to use for
2019 the default Ethernet interface, in case this is not
2020 determined through e.g. bootp.
2021 (Environment variable "ipaddr")
2023 - Server IP address:
2026 Defines a default value for the IP address of a TFTP
2027 server to contact when using the "tftboot" command.
2028 (Environment variable "serverip")
2030 CONFIG_KEEP_SERVERADDR
2032 Keeps the server's MAC address, in the env 'serveraddr'
2033 for passing to bootargs (like Linux's netconsole option)
2035 - Gateway IP address:
2038 Defines a default value for the IP address of the
2039 default router where packets to other networks are
2041 (Environment variable "gatewayip")
2046 Defines a default value for the subnet mask (or
2047 routing prefix) which is used to determine if an IP
2048 address belongs to the local subnet or needs to be
2049 forwarded through a router.
2050 (Environment variable "netmask")
2052 - Multicast TFTP Mode:
2055 Defines whether you want to support multicast TFTP as per
2056 rfc-2090; for example to work with atftp. Lets lots of targets
2057 tftp down the same boot image concurrently. Note: the Ethernet
2058 driver in use must provide a function: mcast() to join/leave a
2061 - BOOTP Recovery Mode:
2062 CONFIG_BOOTP_RANDOM_DELAY
2064 If you have many targets in a network that try to
2065 boot using BOOTP, you may want to avoid that all
2066 systems send out BOOTP requests at precisely the same
2067 moment (which would happen for instance at recovery
2068 from a power failure, when all systems will try to
2069 boot, thus flooding the BOOTP server. Defining
2070 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2071 inserted before sending out BOOTP requests. The
2072 following delays are inserted then:
2074 1st BOOTP request: delay 0 ... 1 sec
2075 2nd BOOTP request: delay 0 ... 2 sec
2076 3rd BOOTP request: delay 0 ... 4 sec
2078 BOOTP requests: delay 0 ... 8 sec
2080 CONFIG_BOOTP_ID_CACHE_SIZE
2082 BOOTP packets are uniquely identified using a 32-bit ID. The
2083 server will copy the ID from client requests to responses and
2084 U-Boot will use this to determine if it is the destination of
2085 an incoming response. Some servers will check that addresses
2086 aren't in use before handing them out (usually using an ARP
2087 ping) and therefore take up to a few hundred milliseconds to
2088 respond. Network congestion may also influence the time it
2089 takes for a response to make it back to the client. If that
2090 time is too long, U-Boot will retransmit requests. In order
2091 to allow earlier responses to still be accepted after these
2092 retransmissions, U-Boot's BOOTP client keeps a small cache of
2093 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2094 cache. The default is to keep IDs for up to four outstanding
2095 requests. Increasing this will allow U-Boot to accept offers
2096 from a BOOTP client in networks with unusually high latency.
2098 - DHCP Advanced Options:
2099 You can fine tune the DHCP functionality by defining
2100 CONFIG_BOOTP_* symbols:
2102 CONFIG_BOOTP_SUBNETMASK
2103 CONFIG_BOOTP_GATEWAY
2104 CONFIG_BOOTP_HOSTNAME
2105 CONFIG_BOOTP_NISDOMAIN
2106 CONFIG_BOOTP_BOOTPATH
2107 CONFIG_BOOTP_BOOTFILESIZE
2110 CONFIG_BOOTP_SEND_HOSTNAME
2111 CONFIG_BOOTP_NTPSERVER
2112 CONFIG_BOOTP_TIMEOFFSET
2113 CONFIG_BOOTP_VENDOREX
2114 CONFIG_BOOTP_MAY_FAIL
2116 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2117 environment variable, not the BOOTP server.
2119 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2120 after the configured retry count, the call will fail
2121 instead of starting over. This can be used to fail over
2122 to Link-local IP address configuration if the DHCP server
2125 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2126 serverip from a DHCP server, it is possible that more
2127 than one DNS serverip is offered to the client.
2128 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2129 serverip will be stored in the additional environment
2130 variable "dnsip2". The first DNS serverip is always
2131 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2134 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2135 to do a dynamic update of a DNS server. To do this, they
2136 need the hostname of the DHCP requester.
2137 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2138 of the "hostname" environment variable is passed as
2139 option 12 to the DHCP server.
2141 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2143 A 32bit value in microseconds for a delay between
2144 receiving a "DHCP Offer" and sending the "DHCP Request".
2145 This fixes a problem with certain DHCP servers that don't
2146 respond 100% of the time to a "DHCP request". E.g. On an
2147 AT91RM9200 processor running at 180MHz, this delay needed
2148 to be *at least* 15,000 usec before a Windows Server 2003
2149 DHCP server would reply 100% of the time. I recommend at
2150 least 50,000 usec to be safe. The alternative is to hope
2151 that one of the retries will be successful but note that
2152 the DHCP timeout and retry process takes a longer than
2155 - Link-local IP address negotiation:
2156 Negotiate with other link-local clients on the local network
2157 for an address that doesn't require explicit configuration.
2158 This is especially useful if a DHCP server cannot be guaranteed
2159 to exist in all environments that the device must operate.
2161 See doc/README.link-local for more information.
2164 CONFIG_CDP_DEVICE_ID
2166 The device id used in CDP trigger frames.
2168 CONFIG_CDP_DEVICE_ID_PREFIX
2170 A two character string which is prefixed to the MAC address
2175 A printf format string which contains the ascii name of
2176 the port. Normally is set to "eth%d" which sets
2177 eth0 for the first Ethernet, eth1 for the second etc.
2179 CONFIG_CDP_CAPABILITIES
2181 A 32bit integer which indicates the device capabilities;
2182 0x00000010 for a normal host which does not forwards.
2186 An ascii string containing the version of the software.
2190 An ascii string containing the name of the platform.
2194 A 32bit integer sent on the trigger.
2196 CONFIG_CDP_POWER_CONSUMPTION
2198 A 16bit integer containing the power consumption of the
2199 device in .1 of milliwatts.
2201 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2203 A byte containing the id of the VLAN.
2205 - Status LED: CONFIG_STATUS_LED
2207 Several configurations allow to display the current
2208 status using a LED. For instance, the LED will blink
2209 fast while running U-Boot code, stop blinking as
2210 soon as a reply to a BOOTP request was received, and
2211 start blinking slow once the Linux kernel is running
2212 (supported by a status LED driver in the Linux
2213 kernel). Defining CONFIG_STATUS_LED enables this
2219 The status LED can be connected to a GPIO pin.
2220 In such cases, the gpio_led driver can be used as a
2221 status LED backend implementation. Define CONFIG_GPIO_LED
2222 to include the gpio_led driver in the U-Boot binary.
2224 CONFIG_GPIO_LED_INVERTED_TABLE
2225 Some GPIO connected LEDs may have inverted polarity in which
2226 case the GPIO high value corresponds to LED off state and
2227 GPIO low value corresponds to LED on state.
2228 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2229 with a list of GPIO LEDs that have inverted polarity.
2231 - CAN Support: CONFIG_CAN_DRIVER
2233 Defining CONFIG_CAN_DRIVER enables CAN driver support
2234 on those systems that support this (optional)
2235 feature, like the TQM8xxL modules.
2237 - I2C Support: CONFIG_SYS_I2C
2239 This enable the NEW i2c subsystem, and will allow you to use
2240 i2c commands at the u-boot command line (as long as you set
2241 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2242 based realtime clock chips or other i2c devices. See
2243 common/cmd_i2c.c for a description of the command line
2246 ported i2c driver to the new framework:
2247 - drivers/i2c/soft_i2c.c:
2248 - activate first bus with CONFIG_SYS_I2C_SOFT define
2249 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2250 for defining speed and slave address
2251 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2252 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2253 for defining speed and slave address
2254 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2255 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2256 for defining speed and slave address
2257 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2258 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2259 for defining speed and slave address
2261 - drivers/i2c/fsl_i2c.c:
2262 - activate i2c driver with CONFIG_SYS_I2C_FSL
2263 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2264 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2265 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2267 - If your board supports a second fsl i2c bus, define
2268 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2269 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2270 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2273 - drivers/i2c/tegra_i2c.c:
2274 - activate this driver with CONFIG_SYS_I2C_TEGRA
2275 - This driver adds 4 i2c buses with a fix speed from
2276 100000 and the slave addr 0!
2278 - drivers/i2c/ppc4xx_i2c.c
2279 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2280 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2281 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2283 - drivers/i2c/i2c_mxc.c
2284 - activate this driver with CONFIG_SYS_I2C_MXC
2285 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2286 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2287 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2288 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2289 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2290 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2291 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2292 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2293 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2294 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2295 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2296 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2297 If those defines are not set, default value is 100000
2298 for speed, and 0 for slave.
2300 - drivers/i2c/rcar_i2c.c:
2301 - activate this driver with CONFIG_SYS_I2C_RCAR
2302 - This driver adds 4 i2c buses
2304 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2305 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2306 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2307 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2308 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2309 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2310 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2311 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2312 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2314 - drivers/i2c/sh_i2c.c:
2315 - activate this driver with CONFIG_SYS_I2C_SH
2316 - This driver adds from 2 to 5 i2c buses
2318 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2319 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2320 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2321 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2322 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2323 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2324 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2325 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2326 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2327 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2328 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2329 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2330 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2332 - drivers/i2c/omap24xx_i2c.c
2333 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2334 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2335 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2336 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2337 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2338 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2339 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2340 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2341 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2342 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2343 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2345 - drivers/i2c/zynq_i2c.c
2346 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2347 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2348 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2350 - drivers/i2c/s3c24x0_i2c.c:
2351 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2352 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2353 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2354 with a fix speed from 100000 and the slave addr 0!
2356 - drivers/i2c/ihs_i2c.c
2357 - activate this driver with CONFIG_SYS_I2C_IHS
2358 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2359 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2360 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2361 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2362 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2363 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2364 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2365 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2366 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2367 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2368 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2369 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2370 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2371 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2372 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2373 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2374 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2375 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2376 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2377 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2378 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2382 CONFIG_SYS_NUM_I2C_BUSES
2383 Hold the number of i2c buses you want to use. If you
2384 don't use/have i2c muxes on your i2c bus, this
2385 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2388 CONFIG_SYS_I2C_DIRECT_BUS
2389 define this, if you don't use i2c muxes on your hardware.
2390 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2393 CONFIG_SYS_I2C_MAX_HOPS
2394 define how many muxes are maximal consecutively connected
2395 on one i2c bus. If you not use i2c muxes, omit this
2398 CONFIG_SYS_I2C_BUSES
2399 hold a list of buses you want to use, only used if
2400 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2401 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2402 CONFIG_SYS_NUM_I2C_BUSES = 9:
2404 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2405 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2406 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2407 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2408 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2409 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2410 {1, {I2C_NULL_HOP}}, \
2411 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2412 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2416 bus 0 on adapter 0 without a mux
2417 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2418 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2419 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2420 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2421 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2422 bus 6 on adapter 1 without a mux
2423 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2424 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2426 If you do not have i2c muxes on your board, omit this define.
2428 - Legacy I2C Support: CONFIG_HARD_I2C
2430 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2431 provides the following compelling advantages:
2433 - more than one i2c adapter is usable
2434 - approved multibus support
2435 - better i2c mux support
2437 ** Please consider updating your I2C driver now. **
2439 These enable legacy I2C serial bus commands. Defining
2440 CONFIG_HARD_I2C will include the appropriate I2C driver
2441 for the selected CPU.
2443 This will allow you to use i2c commands at the u-boot
2444 command line (as long as you set CONFIG_CMD_I2C in
2445 CONFIG_COMMANDS) and communicate with i2c based realtime
2446 clock chips. See common/cmd_i2c.c for a description of the
2447 command line interface.
2449 CONFIG_HARD_I2C selects a hardware I2C controller.
2451 There are several other quantities that must also be
2452 defined when you define CONFIG_HARD_I2C.
2454 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2455 to be the frequency (in Hz) at which you wish your i2c bus
2456 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2457 the CPU's i2c node address).
2459 Now, the u-boot i2c code for the mpc8xx
2460 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2461 and so its address should therefore be cleared to 0 (See,
2462 eg, MPC823e User's Manual p.16-473). So, set
2463 CONFIG_SYS_I2C_SLAVE to 0.
2465 CONFIG_SYS_I2C_INIT_MPC5XXX
2467 When a board is reset during an i2c bus transfer
2468 chips might think that the current transfer is still
2469 in progress. Reset the slave devices by sending start
2470 commands until the slave device responds.
2472 That's all that's required for CONFIG_HARD_I2C.
2474 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2475 then the following macros need to be defined (examples are
2476 from include/configs/lwmon.h):
2480 (Optional). Any commands necessary to enable the I2C
2481 controller or configure ports.
2483 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2487 (Only for MPC8260 CPU). The I/O port to use (the code
2488 assumes both bits are on the same port). Valid values
2489 are 0..3 for ports A..D.
2493 The code necessary to make the I2C data line active
2494 (driven). If the data line is open collector, this
2497 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2501 The code necessary to make the I2C data line tri-stated
2502 (inactive). If the data line is open collector, this
2505 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2509 Code that returns true if the I2C data line is high,
2512 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2516 If <bit> is true, sets the I2C data line high. If it
2517 is false, it clears it (low).
2519 eg: #define I2C_SDA(bit) \
2520 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2521 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2525 If <bit> is true, sets the I2C clock line high. If it
2526 is false, it clears it (low).
2528 eg: #define I2C_SCL(bit) \
2529 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2530 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2534 This delay is invoked four times per clock cycle so this
2535 controls the rate of data transfer. The data rate thus
2536 is 1 / (I2C_DELAY * 4). Often defined to be something
2539 #define I2C_DELAY udelay(2)
2541 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2543 If your arch supports the generic GPIO framework (asm/gpio.h),
2544 then you may alternatively define the two GPIOs that are to be
2545 used as SCL / SDA. Any of the previous I2C_xxx macros will
2546 have GPIO-based defaults assigned to them as appropriate.
2548 You should define these to the GPIO value as given directly to
2549 the generic GPIO functions.
2551 CONFIG_SYS_I2C_INIT_BOARD
2553 When a board is reset during an i2c bus transfer
2554 chips might think that the current transfer is still
2555 in progress. On some boards it is possible to access
2556 the i2c SCLK line directly, either by using the
2557 processor pin as a GPIO or by having a second pin
2558 connected to the bus. If this option is defined a
2559 custom i2c_init_board() routine in boards/xxx/board.c
2560 is run early in the boot sequence.
2562 CONFIG_SYS_I2C_BOARD_LATE_INIT
2564 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2565 defined a custom i2c_board_late_init() routine in
2566 boards/xxx/board.c is run AFTER the operations in i2c_init()
2567 is completed. This callpoint can be used to unreset i2c bus
2568 using CPU i2c controller register accesses for CPUs whose i2c
2569 controller provide such a method. It is called at the end of
2570 i2c_init() to allow i2c_init operations to setup the i2c bus
2571 controller on the CPU (e.g. setting bus speed & slave address).
2573 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2575 This option enables configuration of bi_iic_fast[] flags
2576 in u-boot bd_info structure based on u-boot environment
2577 variable "i2cfast". (see also i2cfast)
2579 CONFIG_I2C_MULTI_BUS
2581 This option allows the use of multiple I2C buses, each of which
2582 must have a controller. At any point in time, only one bus is
2583 active. To switch to a different bus, use the 'i2c dev' command.
2584 Note that bus numbering is zero-based.
2586 CONFIG_SYS_I2C_NOPROBES
2588 This option specifies a list of I2C devices that will be skipped
2589 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2590 is set, specify a list of bus-device pairs. Otherwise, specify
2591 a 1D array of device addresses
2594 #undef CONFIG_I2C_MULTI_BUS
2595 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2597 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2599 #define CONFIG_I2C_MULTI_BUS
2600 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2602 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2604 CONFIG_SYS_SPD_BUS_NUM
2606 If defined, then this indicates the I2C bus number for DDR SPD.
2607 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2609 CONFIG_SYS_RTC_BUS_NUM
2611 If defined, then this indicates the I2C bus number for the RTC.
2612 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2614 CONFIG_SYS_DTT_BUS_NUM
2616 If defined, then this indicates the I2C bus number for the DTT.
2617 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2619 CONFIG_SYS_I2C_DTT_ADDR:
2621 If defined, specifies the I2C address of the DTT device.
2622 If not defined, then U-Boot uses predefined value for
2623 specified DTT device.
2625 CONFIG_SOFT_I2C_READ_REPEATED_START
2627 defining this will force the i2c_read() function in
2628 the soft_i2c driver to perform an I2C repeated start
2629 between writing the address pointer and reading the
2630 data. If this define is omitted the default behaviour
2631 of doing a stop-start sequence will be used. Most I2C
2632 devices can use either method, but some require one or
2635 - SPI Support: CONFIG_SPI
2637 Enables SPI driver (so far only tested with
2638 SPI EEPROM, also an instance works with Crystal A/D and
2639 D/As on the SACSng board)
2643 Enables the driver for SPI controller on SuperH. Currently
2644 only SH7757 is supported.
2648 Enables a software (bit-bang) SPI driver rather than
2649 using hardware support. This is a general purpose
2650 driver that only requires three general I/O port pins
2651 (two outputs, one input) to function. If this is
2652 defined, the board configuration must define several
2653 SPI configuration items (port pins to use, etc). For
2654 an example, see include/configs/sacsng.h.
2658 Enables a hardware SPI driver for general-purpose reads
2659 and writes. As with CONFIG_SOFT_SPI, the board configuration
2660 must define a list of chip-select function pointers.
2661 Currently supported on some MPC8xxx processors. For an
2662 example, see include/configs/mpc8349emds.h.
2666 Enables the driver for the SPI controllers on i.MX and MXC
2667 SoCs. Currently i.MX31/35/51 are supported.
2669 CONFIG_SYS_SPI_MXC_WAIT
2670 Timeout for waiting until spi transfer completed.
2671 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2673 - FPGA Support: CONFIG_FPGA
2675 Enables FPGA subsystem.
2677 CONFIG_FPGA_<vendor>
2679 Enables support for specific chip vendors.
2682 CONFIG_FPGA_<family>
2684 Enables support for FPGA family.
2685 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2689 Specify the number of FPGA devices to support.
2691 CONFIG_CMD_FPGA_LOADMK
2693 Enable support for fpga loadmk command
2695 CONFIG_CMD_FPGA_LOADP
2697 Enable support for fpga loadp command - load partial bitstream
2699 CONFIG_CMD_FPGA_LOADBP
2701 Enable support for fpga loadbp command - load partial bitstream
2704 CONFIG_SYS_FPGA_PROG_FEEDBACK
2706 Enable printing of hash marks during FPGA configuration.
2708 CONFIG_SYS_FPGA_CHECK_BUSY
2710 Enable checks on FPGA configuration interface busy
2711 status by the configuration function. This option
2712 will require a board or device specific function to
2717 If defined, a function that provides delays in the FPGA
2718 configuration driver.
2720 CONFIG_SYS_FPGA_CHECK_CTRLC
2721 Allow Control-C to interrupt FPGA configuration
2723 CONFIG_SYS_FPGA_CHECK_ERROR
2725 Check for configuration errors during FPGA bitfile
2726 loading. For example, abort during Virtex II
2727 configuration if the INIT_B line goes low (which
2728 indicated a CRC error).
2730 CONFIG_SYS_FPGA_WAIT_INIT
2732 Maximum time to wait for the INIT_B line to de-assert
2733 after PROB_B has been de-asserted during a Virtex II
2734 FPGA configuration sequence. The default time is 500
2737 CONFIG_SYS_FPGA_WAIT_BUSY
2739 Maximum time to wait for BUSY to de-assert during
2740 Virtex II FPGA configuration. The default is 5 ms.
2742 CONFIG_SYS_FPGA_WAIT_CONFIG
2744 Time to wait after FPGA configuration. The default is
2747 - Configuration Management:
2750 Some SoCs need special image types (e.g. U-Boot binary
2751 with a special header) as build targets. By defining
2752 CONFIG_BUILD_TARGET in the SoC / board header, this
2753 special image will be automatically built upon calling
2758 If defined, this string will be added to the U-Boot
2759 version information (U_BOOT_VERSION)
2761 - Vendor Parameter Protection:
2763 U-Boot considers the values of the environment
2764 variables "serial#" (Board Serial Number) and
2765 "ethaddr" (Ethernet Address) to be parameters that
2766 are set once by the board vendor / manufacturer, and
2767 protects these variables from casual modification by
2768 the user. Once set, these variables are read-only,
2769 and write or delete attempts are rejected. You can
2770 change this behaviour:
2772 If CONFIG_ENV_OVERWRITE is #defined in your config
2773 file, the write protection for vendor parameters is
2774 completely disabled. Anybody can change or delete
2777 Alternatively, if you define _both_ an ethaddr in the
2778 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2779 Ethernet address is installed in the environment,
2780 which can be changed exactly ONCE by the user. [The
2781 serial# is unaffected by this, i. e. it remains
2784 The same can be accomplished in a more flexible way
2785 for any variable by configuring the type of access
2786 to allow for those variables in the ".flags" variable
2787 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2792 Define this variable to enable the reservation of
2793 "protected RAM", i. e. RAM which is not overwritten
2794 by U-Boot. Define CONFIG_PRAM to hold the number of
2795 kB you want to reserve for pRAM. You can overwrite
2796 this default value by defining an environment
2797 variable "pram" to the number of kB you want to
2798 reserve. Note that the board info structure will
2799 still show the full amount of RAM. If pRAM is
2800 reserved, a new environment variable "mem" will
2801 automatically be defined to hold the amount of
2802 remaining RAM in a form that can be passed as boot
2803 argument to Linux, for instance like that:
2805 setenv bootargs ... mem=\${mem}
2808 This way you can tell Linux not to use this memory,
2809 either, which results in a memory region that will
2810 not be affected by reboots.
2812 *WARNING* If your board configuration uses automatic
2813 detection of the RAM size, you must make sure that
2814 this memory test is non-destructive. So far, the
2815 following board configurations are known to be
2818 IVMS8, IVML24, SPD8xx, TQM8xxL,
2819 HERMES, IP860, RPXlite, LWMON,
2822 - Access to physical memory region (> 4GB)
2823 Some basic support is provided for operations on memory not
2824 normally accessible to U-Boot - e.g. some architectures
2825 support access to more than 4GB of memory on 32-bit
2826 machines using physical address extension or similar.
2827 Define CONFIG_PHYSMEM to access this basic support, which
2828 currently only supports clearing the memory.
2833 Define this variable to stop the system in case of a
2834 fatal error, so that you have to reset it manually.
2835 This is probably NOT a good idea for an embedded
2836 system where you want the system to reboot
2837 automatically as fast as possible, but it may be
2838 useful during development since you can try to debug
2839 the conditions that lead to the situation.
2841 CONFIG_NET_RETRY_COUNT
2843 This variable defines the number of retries for
2844 network operations like ARP, RARP, TFTP, or BOOTP
2845 before giving up the operation. If not defined, a
2846 default value of 5 is used.
2850 Timeout waiting for an ARP reply in milliseconds.
2854 Timeout in milliseconds used in NFS protocol.
2855 If you encounter "ERROR: Cannot umount" in nfs command,
2856 try longer timeout such as
2857 #define CONFIG_NFS_TIMEOUT 10000UL
2859 - Command Interpreter:
2860 CONFIG_AUTO_COMPLETE
2862 Enable auto completion of commands using TAB.
2864 CONFIG_SYS_PROMPT_HUSH_PS2
2866 This defines the secondary prompt string, which is
2867 printed when the command interpreter needs more input
2868 to complete a command. Usually "> ".
2872 In the current implementation, the local variables
2873 space and global environment variables space are
2874 separated. Local variables are those you define by
2875 simply typing `name=value'. To access a local
2876 variable later on, you have write `$name' or
2877 `${name}'; to execute the contents of a variable
2878 directly type `$name' at the command prompt.
2880 Global environment variables are those you use
2881 setenv/printenv to work with. To run a command stored
2882 in such a variable, you need to use the run command,
2883 and you must not use the '$' sign to access them.
2885 To store commands and special characters in a
2886 variable, please use double quotation marks
2887 surrounding the whole text of the variable, instead
2888 of the backslashes before semicolons and special
2891 - Command Line Editing and History:
2892 CONFIG_CMDLINE_EDITING
2894 Enable editing and History functions for interactive
2895 command line input operations
2897 - Default Environment:
2898 CONFIG_EXTRA_ENV_SETTINGS
2900 Define this to contain any number of null terminated
2901 strings (variable = value pairs) that will be part of
2902 the default environment compiled into the boot image.
2904 For example, place something like this in your
2905 board's config file:
2907 #define CONFIG_EXTRA_ENV_SETTINGS \
2911 Warning: This method is based on knowledge about the
2912 internal format how the environment is stored by the
2913 U-Boot code. This is NOT an official, exported
2914 interface! Although it is unlikely that this format
2915 will change soon, there is no guarantee either.
2916 You better know what you are doing here.
2918 Note: overly (ab)use of the default environment is
2919 discouraged. Make sure to check other ways to preset
2920 the environment like the "source" command or the
2923 CONFIG_ENV_VARS_UBOOT_CONFIG
2925 Define this in order to add variables describing the
2926 U-Boot build configuration to the default environment.
2927 These will be named arch, cpu, board, vendor, and soc.
2929 Enabling this option will cause the following to be defined:
2937 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2939 Define this in order to add variables describing certain
2940 run-time determined information about the hardware to the
2941 environment. These will be named board_name, board_rev.
2943 CONFIG_DELAY_ENVIRONMENT
2945 Normally the environment is loaded when the board is
2946 initialised so that it is available to U-Boot. This inhibits
2947 that so that the environment is not available until
2948 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2949 this is instead controlled by the value of
2950 /config/load-environment.
2952 - Parallel Flash support:
2955 Traditionally U-boot was run on systems with parallel NOR
2956 flash. This option is used to disable support for parallel NOR
2957 flash. This option should be defined if the board does not have
2960 If this option is not defined one of the generic flash drivers
2961 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2962 selected or the board must provide an implementation of the
2963 flash API (see include/flash.h).
2965 - DataFlash Support:
2966 CONFIG_HAS_DATAFLASH
2968 Defining this option enables DataFlash features and
2969 allows to read/write in Dataflash via the standard
2972 - Serial Flash support
2975 Defining this option enables SPI flash commands
2976 'sf probe/read/write/erase/update'.
2978 Usage requires an initial 'probe' to define the serial
2979 flash parameters, followed by read/write/erase/update
2982 The following defaults may be provided by the platform
2983 to handle the common case when only a single serial
2984 flash is present on the system.
2986 CONFIG_SF_DEFAULT_BUS Bus identifier
2987 CONFIG_SF_DEFAULT_CS Chip-select
2988 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2989 CONFIG_SF_DEFAULT_SPEED in Hz
2993 Define this option to include a destructive SPI flash
2996 CONFIG_SF_DUAL_FLASH Dual flash memories
2998 Define this option to use dual flash support where two flash
2999 memories can be connected with a given cs line.
3000 Currently Xilinx Zynq qspi supports these type of connections.
3002 - SystemACE Support:
3005 Adding this option adds support for Xilinx SystemACE
3006 chips attached via some sort of local bus. The address
3007 of the chip must also be defined in the
3008 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3010 #define CONFIG_SYSTEMACE
3011 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3013 When SystemACE support is added, the "ace" device type
3014 becomes available to the fat commands, i.e. fatls.
3016 - TFTP Fixed UDP Port:
3019 If this is defined, the environment variable tftpsrcp
3020 is used to supply the TFTP UDP source port value.
3021 If tftpsrcp isn't defined, the normal pseudo-random port
3022 number generator is used.
3024 Also, the environment variable tftpdstp is used to supply
3025 the TFTP UDP destination port value. If tftpdstp isn't
3026 defined, the normal port 69 is used.
3028 The purpose for tftpsrcp is to allow a TFTP server to
3029 blindly start the TFTP transfer using the pre-configured
3030 target IP address and UDP port. This has the effect of
3031 "punching through" the (Windows XP) firewall, allowing
3032 the remainder of the TFTP transfer to proceed normally.
3033 A better solution is to properly configure the firewall,
3034 but sometimes that is not allowed.
3039 This enables a generic 'hash' command which can produce
3040 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3044 Enable the hash verify command (hash -v). This adds to code
3047 CONFIG_SHA1 - This option enables support of hashing using SHA1
3048 algorithm. The hash is calculated in software.
3049 CONFIG_SHA256 - This option enables support of hashing using
3050 SHA256 algorithm. The hash is calculated in software.
3051 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3052 for SHA1/SHA256 hashing.
3053 This affects the 'hash' command and also the
3054 hash_lookup_algo() function.
3055 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3056 hardware-acceleration for SHA1/SHA256 progressive hashing.
3057 Data can be streamed in a block at a time and the hashing
3058 is performed in hardware.
3060 Note: There is also a sha1sum command, which should perhaps
3061 be deprecated in favour of 'hash sha1'.
3063 - Freescale i.MX specific commands:
3064 CONFIG_CMD_HDMIDETECT
3065 This enables 'hdmidet' command which returns true if an
3066 HDMI monitor is detected. This command is i.MX 6 specific.
3069 This enables the 'bmode' (bootmode) command for forcing
3070 a boot from specific media.
3072 This is useful for forcing the ROM's usb downloader to
3073 activate upon a watchdog reset which is nice when iterating
3074 on U-Boot. Using the reset button or running bmode normal
3075 will set it back to normal. This command currently
3076 supports i.MX53 and i.MX6.
3081 This enables the RSA algorithm used for FIT image verification
3082 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3084 The Modular Exponentiation algorithm in RSA is implemented using
3085 driver model. So CONFIG_DM needs to be enabled by default for this
3086 library to function.
3088 The signing part is build into mkimage regardless of this
3089 option. The software based modular exponentiation is built into
3090 mkimage irrespective of this option.
3092 - bootcount support:
3093 CONFIG_BOOTCOUNT_LIMIT
3095 This enables the bootcounter support, see:
3096 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3099 enable special bootcounter support on at91sam9xe based boards.
3101 enable special bootcounter support on blackfin based boards.
3103 enable special bootcounter support on da850 based boards.
3104 CONFIG_BOOTCOUNT_RAM
3105 enable support for the bootcounter in RAM
3106 CONFIG_BOOTCOUNT_I2C
3107 enable support for the bootcounter on an i2c (like RTC) device.
3108 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3109 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3111 CONFIG_BOOTCOUNT_ALEN = address len
3113 - Show boot progress:
3114 CONFIG_SHOW_BOOT_PROGRESS
3116 Defining this option allows to add some board-
3117 specific code (calling a user-provided function
3118 "show_boot_progress(int)") that enables you to show
3119 the system's boot progress on some display (for
3120 example, some LED's) on your board. At the moment,
3121 the following checkpoints are implemented:
3124 Legacy uImage format:
3127 1 common/cmd_bootm.c before attempting to boot an image
3128 -1 common/cmd_bootm.c Image header has bad magic number
3129 2 common/cmd_bootm.c Image header has correct magic number
3130 -2 common/cmd_bootm.c Image header has bad checksum
3131 3 common/cmd_bootm.c Image header has correct checksum
3132 -3 common/cmd_bootm.c Image data has bad checksum
3133 4 common/cmd_bootm.c Image data has correct checksum
3134 -4 common/cmd_bootm.c Image is for unsupported architecture
3135 5 common/cmd_bootm.c Architecture check OK
3136 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3137 6 common/cmd_bootm.c Image Type check OK
3138 -6 common/cmd_bootm.c gunzip uncompression error
3139 -7 common/cmd_bootm.c Unimplemented compression type
3140 7 common/cmd_bootm.c Uncompression OK
3141 8 common/cmd_bootm.c No uncompress/copy overwrite error
3142 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3144 9 common/image.c Start initial ramdisk verification
3145 -10 common/image.c Ramdisk header has bad magic number
3146 -11 common/image.c Ramdisk header has bad checksum
3147 10 common/image.c Ramdisk header is OK
3148 -12 common/image.c Ramdisk data has bad checksum
3149 11 common/image.c Ramdisk data has correct checksum
3150 12 common/image.c Ramdisk verification complete, start loading
3151 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3152 13 common/image.c Start multifile image verification
3153 14 common/image.c No initial ramdisk, no multifile, continue.
3155 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3157 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3158 -31 post/post.c POST test failed, detected by post_output_backlog()
3159 -32 post/post.c POST test failed, detected by post_run_single()
3161 34 common/cmd_doc.c before loading a Image from a DOC device
3162 -35 common/cmd_doc.c Bad usage of "doc" command
3163 35 common/cmd_doc.c correct usage of "doc" command
3164 -36 common/cmd_doc.c No boot device
3165 36 common/cmd_doc.c correct boot device
3166 -37 common/cmd_doc.c Unknown Chip ID on boot device
3167 37 common/cmd_doc.c correct chip ID found, device available
3168 -38 common/cmd_doc.c Read Error on boot device
3169 38 common/cmd_doc.c reading Image header from DOC device OK
3170 -39 common/cmd_doc.c Image header has bad magic number
3171 39 common/cmd_doc.c Image header has correct magic number
3172 -40 common/cmd_doc.c Error reading Image from DOC device
3173 40 common/cmd_doc.c Image header has correct magic number
3174 41 common/cmd_ide.c before loading a Image from a IDE device
3175 -42 common/cmd_ide.c Bad usage of "ide" command
3176 42 common/cmd_ide.c correct usage of "ide" command
3177 -43 common/cmd_ide.c No boot device
3178 43 common/cmd_ide.c boot device found
3179 -44 common/cmd_ide.c Device not available
3180 44 common/cmd_ide.c Device available
3181 -45 common/cmd_ide.c wrong partition selected
3182 45 common/cmd_ide.c partition selected
3183 -46 common/cmd_ide.c Unknown partition table
3184 46 common/cmd_ide.c valid partition table found
3185 -47 common/cmd_ide.c Invalid partition type
3186 47 common/cmd_ide.c correct partition type
3187 -48 common/cmd_ide.c Error reading Image Header on boot device
3188 48 common/cmd_ide.c reading Image Header from IDE device OK
3189 -49 common/cmd_ide.c Image header has bad magic number
3190 49 common/cmd_ide.c Image header has correct magic number
3191 -50 common/cmd_ide.c Image header has bad checksum
3192 50 common/cmd_ide.c Image header has correct checksum
3193 -51 common/cmd_ide.c Error reading Image from IDE device
3194 51 common/cmd_ide.c reading Image from IDE device OK
3195 52 common/cmd_nand.c before loading a Image from a NAND device
3196 -53 common/cmd_nand.c Bad usage of "nand" command
3197 53 common/cmd_nand.c correct usage of "nand" command
3198 -54 common/cmd_nand.c No boot device
3199 54 common/cmd_nand.c boot device found
3200 -55 common/cmd_nand.c Unknown Chip ID on boot device
3201 55 common/cmd_nand.c correct chip ID found, device available
3202 -56 common/cmd_nand.c Error reading Image Header on boot device
3203 56 common/cmd_nand.c reading Image Header from NAND device OK
3204 -57 common/cmd_nand.c Image header has bad magic number
3205 57 common/cmd_nand.c Image header has correct magic number
3206 -58 common/cmd_nand.c Error reading Image from NAND device
3207 58 common/cmd_nand.c reading Image from NAND device OK
3209 -60 common/env_common.c Environment has a bad CRC, using default
3211 64 net/eth.c starting with Ethernet configuration.
3212 -64 net/eth.c no Ethernet found.
3213 65 net/eth.c Ethernet found.
3215 -80 common/cmd_net.c usage wrong
3216 80 common/cmd_net.c before calling net_loop()
3217 -81 common/cmd_net.c some error in net_loop() occurred
3218 81 common/cmd_net.c net_loop() back without error
3219 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3220 82 common/cmd_net.c trying automatic boot
3221 83 common/cmd_net.c running "source" command
3222 -83 common/cmd_net.c some error in automatic boot or "source" command
3223 84 common/cmd_net.c end without errors
3228 100 common/cmd_bootm.c Kernel FIT Image has correct format
3229 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3230 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3231 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3232 102 common/cmd_bootm.c Kernel unit name specified
3233 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3234 103 common/cmd_bootm.c Found configuration node
3235 104 common/cmd_bootm.c Got kernel subimage node offset
3236 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3237 105 common/cmd_bootm.c Kernel subimage hash verification OK
3238 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3239 106 common/cmd_bootm.c Architecture check OK
3240 -106 common/cmd_bootm.c Kernel subimage has wrong type
3241 107 common/cmd_bootm.c Kernel subimage type OK
3242 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3243 108 common/cmd_bootm.c Got kernel subimage data/size
3244 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3245 -109 common/cmd_bootm.c Can't get kernel subimage type
3246 -110 common/cmd_bootm.c Can't get kernel subimage comp
3247 -111 common/cmd_bootm.c Can't get kernel subimage os
3248 -112 common/cmd_bootm.c Can't get kernel subimage load address
3249 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3251 120 common/image.c Start initial ramdisk verification
3252 -120 common/image.c Ramdisk FIT image has incorrect format
3253 121 common/image.c Ramdisk FIT image has correct format
3254 122 common/image.c No ramdisk subimage unit name, using configuration
3255 -122 common/image.c Can't get configuration for ramdisk subimage
3256 123 common/image.c Ramdisk unit name specified
3257 -124 common/image.c Can't get ramdisk subimage node offset
3258 125 common/image.c Got ramdisk subimage node offset
3259 -125 common/image.c Ramdisk subimage hash verification failed
3260 126 common/image.c Ramdisk subimage hash verification OK
3261 -126 common/image.c Ramdisk subimage for unsupported architecture
3262 127 common/image.c Architecture check OK
3263 -127 common/image.c Can't get ramdisk subimage data/size
3264 128 common/image.c Got ramdisk subimage data/size
3265 129 common/image.c Can't get ramdisk load address
3266 -129 common/image.c Got ramdisk load address
3268 -130 common/cmd_doc.c Incorrect FIT image format
3269 131 common/cmd_doc.c FIT image format OK
3271 -140 common/cmd_ide.c Incorrect FIT image format
3272 141 common/cmd_ide.c FIT image format OK
3274 -150 common/cmd_nand.c Incorrect FIT image format
3275 151 common/cmd_nand.c FIT image format OK
3277 - legacy image format:
3278 CONFIG_IMAGE_FORMAT_LEGACY
3279 enables the legacy image format support in U-Boot.
3282 enabled if CONFIG_FIT_SIGNATURE is not defined.
3284 CONFIG_DISABLE_IMAGE_LEGACY
3285 disable the legacy image format
3287 This define is introduced, as the legacy image format is
3288 enabled per default for backward compatibility.
3290 - FIT image support:
3292 Enable support for the FIT uImage format.
3294 CONFIG_FIT_BEST_MATCH
3295 When no configuration is explicitly selected, default to the
3296 one whose fdt's compatibility field best matches that of
3297 U-Boot itself. A match is considered "best" if it matches the
3298 most specific compatibility entry of U-Boot's fdt's root node.
3299 The order of entries in the configuration's fdt is ignored.
3301 CONFIG_FIT_SIGNATURE
3302 This option enables signature verification of FIT uImages,
3303 using a hash signed and verified using RSA. If
3304 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3305 hashing is available using hardware, RSA library will use it.
3306 See doc/uImage.FIT/signature.txt for more details.
3308 WARNING: When relying on signed FIT images with required
3309 signature check the legacy image format is default
3310 disabled. If a board need legacy image format support
3311 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3313 CONFIG_FIT_DISABLE_SHA256
3314 Supporting SHA256 hashes has quite an impact on binary size.
3315 For constrained systems sha256 hash support can be disabled
3318 - Standalone program support:
3319 CONFIG_STANDALONE_LOAD_ADDR
3321 This option defines a board specific value for the
3322 address where standalone program gets loaded, thus
3323 overwriting the architecture dependent default
3326 - Frame Buffer Address:
3329 Define CONFIG_FB_ADDR if you want to use specific
3330 address for frame buffer. This is typically the case
3331 when using a graphics controller has separate video
3332 memory. U-Boot will then place the frame buffer at
3333 the given address instead of dynamically reserving it
3334 in system RAM by calling lcd_setmem(), which grabs
3335 the memory for the frame buffer depending on the
3336 configured panel size.
3338 Please see board_init_f function.
3340 - Automatic software updates via TFTP server
3342 CONFIG_UPDATE_TFTP_CNT_MAX
3343 CONFIG_UPDATE_TFTP_MSEC_MAX
3345 These options enable and control the auto-update feature;
3346 for a more detailed description refer to doc/README.update.
3348 - MTD Support (mtdparts command, UBI support)
3351 Adds the MTD device infrastructure from the Linux kernel.
3352 Needed for mtdparts command support.
3354 CONFIG_MTD_PARTITIONS
3356 Adds the MTD partitioning infrastructure from the Linux
3357 kernel. Needed for UBI support.
3362 Adds commands for interacting with MTD partitions formatted
3363 with the UBI flash translation layer
3365 Requires also defining CONFIG_RBTREE
3367 CONFIG_UBI_SILENCE_MSG
3369 Make the verbose messages from UBI stop printing. This leaves
3370 warnings and errors enabled.
3373 CONFIG_MTD_UBI_WL_THRESHOLD
3374 This parameter defines the maximum difference between the highest
3375 erase counter value and the lowest erase counter value of eraseblocks
3376 of UBI devices. When this threshold is exceeded, UBI starts performing
3377 wear leveling by means of moving data from eraseblock with low erase
3378 counter to eraseblocks with high erase counter.
3380 The default value should be OK for SLC NAND flashes, NOR flashes and
3381 other flashes which have eraseblock life-cycle 100000 or more.
3382 However, in case of MLC NAND flashes which typically have eraseblock
3383 life-cycle less than 10000, the threshold should be lessened (e.g.,
3384 to 128 or 256, although it does not have to be power of 2).
3388 CONFIG_MTD_UBI_BEB_LIMIT
3389 This option specifies the maximum bad physical eraseblocks UBI
3390 expects on the MTD device (per 1024 eraseblocks). If the
3391 underlying flash does not admit of bad eraseblocks (e.g. NOR
3392 flash), this value is ignored.
3394 NAND datasheets often specify the minimum and maximum NVM
3395 (Number of Valid Blocks) for the flashes' endurance lifetime.
3396 The maximum expected bad eraseblocks per 1024 eraseblocks
3397 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3398 which gives 20 for most NANDs (MaxNVB is basically the total
3399 count of eraseblocks on the chip).
3401 To put it differently, if this value is 20, UBI will try to
3402 reserve about 1.9% of physical eraseblocks for bad blocks
3403 handling. And that will be 1.9% of eraseblocks on the entire
3404 NAND chip, not just the MTD partition UBI attaches. This means
3405 that if you have, say, a NAND flash chip admits maximum 40 bad
3406 eraseblocks, and it is split on two MTD partitions of the same
3407 size, UBI will reserve 40 eraseblocks when attaching a
3412 CONFIG_MTD_UBI_FASTMAP
3413 Fastmap is a mechanism which allows attaching an UBI device
3414 in nearly constant time. Instead of scanning the whole MTD device it
3415 only has to locate a checkpoint (called fastmap) on the device.
3416 The on-flash fastmap contains all information needed to attach
3417 the device. Using fastmap makes only sense on large devices where
3418 attaching by scanning takes long. UBI will not automatically install
3419 a fastmap on old images, but you can set the UBI parameter
3420 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3421 that fastmap-enabled images are still usable with UBI implementations
3422 without fastmap support. On typical flash devices the whole fastmap
3423 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3425 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3426 Set this parameter to enable fastmap automatically on images
3430 CONFIG_MTD_UBI_FM_DEBUG
3431 Enable UBI fastmap debug
3437 Adds commands for interacting with UBI volumes formatted as
3438 UBIFS. UBIFS is read-only in u-boot.
3440 Requires UBI support as well as CONFIG_LZO
3442 CONFIG_UBIFS_SILENCE_MSG
3444 Make the verbose messages from UBIFS stop printing. This leaves
3445 warnings and errors enabled.
3449 Enable building of SPL globally.
3452 LDSCRIPT for linking the SPL binary.
3454 CONFIG_SPL_MAX_FOOTPRINT
3455 Maximum size in memory allocated to the SPL, BSS included.
3456 When defined, the linker checks that the actual memory
3457 used by SPL from _start to __bss_end does not exceed it.
3458 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3459 must not be both defined at the same time.
3462 Maximum size of the SPL image (text, data, rodata, and
3463 linker lists sections), BSS excluded.
3464 When defined, the linker checks that the actual size does
3467 CONFIG_SPL_TEXT_BASE
3468 TEXT_BASE for linking the SPL binary.
3470 CONFIG_SPL_RELOC_TEXT_BASE
3471 Address to relocate to. If unspecified, this is equal to
3472 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3474 CONFIG_SPL_BSS_START_ADDR
3475 Link address for the BSS within the SPL binary.
3477 CONFIG_SPL_BSS_MAX_SIZE
3478 Maximum size in memory allocated to the SPL BSS.
3479 When defined, the linker checks that the actual memory used
3480 by SPL from __bss_start to __bss_end does not exceed it.
3481 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3482 must not be both defined at the same time.
3485 Adress of the start of the stack SPL will use
3487 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3488 When defined, SPL will panic() if the image it has
3489 loaded does not have a signature.
3490 Defining this is useful when code which loads images
3491 in SPL cannot guarantee that absolutely all read errors
3493 An example is the LPC32XX MLC NAND driver, which will
3494 consider that a completely unreadable NAND block is bad,
3495 and thus should be skipped silently.
3497 CONFIG_SPL_RELOC_STACK
3498 Adress of the start of the stack SPL will use after
3499 relocation. If unspecified, this is equal to
3502 CONFIG_SYS_SPL_MALLOC_START
3503 Starting address of the malloc pool used in SPL.
3504 When this option is set the full malloc is used in SPL and
3505 it is set up by spl_init() and before that, the simple malloc()
3506 can be used if CONFIG_SYS_MALLOC_F is defined.
3508 CONFIG_SYS_SPL_MALLOC_SIZE
3509 The size of the malloc pool used in SPL.
3511 CONFIG_SPL_FRAMEWORK
3512 Enable the SPL framework under common/. This framework
3513 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3514 NAND loading of the Linux Kernel.
3517 Enable booting directly to an OS from SPL.
3518 See also: doc/README.falcon
3520 CONFIG_SPL_DISPLAY_PRINT
3521 For ARM, enable an optional function to print more information
3522 about the running system.
3524 CONFIG_SPL_INIT_MINIMAL
3525 Arch init code should be built for a very small image
3527 CONFIG_SPL_LIBCOMMON_SUPPORT
3528 Support for common/libcommon.o in SPL binary
3530 CONFIG_SPL_LIBDISK_SUPPORT
3531 Support for disk/libdisk.o in SPL binary
3533 CONFIG_SPL_I2C_SUPPORT
3534 Support for drivers/i2c/libi2c.o in SPL binary
3536 CONFIG_SPL_GPIO_SUPPORT
3537 Support for drivers/gpio/libgpio.o in SPL binary
3539 CONFIG_SPL_MMC_SUPPORT
3540 Support for drivers/mmc/libmmc.o in SPL binary
3542 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3543 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3544 Address and partition on the MMC to load U-Boot from
3545 when the MMC is being used in raw mode.
3547 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3548 Partition on the MMC to load U-Boot from when the MMC is being
3551 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3552 Sector to load kernel uImage from when MMC is being
3553 used in raw mode (for Falcon mode)
3555 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3556 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3557 Sector and number of sectors to load kernel argument
3558 parameters from when MMC is being used in raw mode
3561 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3562 Partition on the MMC to load U-Boot from when the MMC is being
3565 CONFIG_SPL_FAT_SUPPORT
3566 Support for fs/fat/libfat.o in SPL binary
3568 CONFIG_SPL_EXT_SUPPORT
3569 Support for EXT filesystem in SPL binary
3571 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3572 Filename to read to load U-Boot when reading from filesystem
3574 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3575 Filename to read to load kernel uImage when reading
3576 from filesystem (for Falcon mode)
3578 CONFIG_SPL_FS_LOAD_ARGS_NAME
3579 Filename to read to load kernel argument parameters
3580 when reading from filesystem (for Falcon mode)
3582 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3583 Set this for NAND SPL on PPC mpc83xx targets, so that
3584 start.S waits for the rest of the SPL to load before
3585 continuing (the hardware starts execution after just
3586 loading the first page rather than the full 4K).
3588 CONFIG_SPL_SKIP_RELOCATE
3589 Avoid SPL relocation
3591 CONFIG_SPL_NAND_BASE
3592 Include nand_base.c in the SPL. Requires
3593 CONFIG_SPL_NAND_DRIVERS.
3595 CONFIG_SPL_NAND_DRIVERS
3596 SPL uses normal NAND drivers, not minimal drivers.
3599 Include standard software ECC in the SPL
3601 CONFIG_SPL_NAND_SIMPLE
3602 Support for NAND boot using simple NAND drivers that
3603 expose the cmd_ctrl() interface.
3605 CONFIG_SPL_MTD_SUPPORT
3606 Support for the MTD subsystem within SPL. Useful for
3607 environment on NAND support within SPL.
3609 CONFIG_SPL_NAND_RAW_ONLY
3610 Support to boot only raw u-boot.bin images. Use this only
3611 if you need to save space.
3613 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3614 Set for the SPL on PPC mpc8xxx targets, support for
3615 drivers/ddr/fsl/libddr.o in SPL binary.
3617 CONFIG_SPL_COMMON_INIT_DDR
3618 Set for common ddr init with serial presence detect in
3621 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3622 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3623 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3624 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3625 CONFIG_SYS_NAND_ECCBYTES
3626 Defines the size and behavior of the NAND that SPL uses
3629 CONFIG_SPL_NAND_BOOT
3630 Add support NAND boot
3632 CONFIG_SYS_NAND_U_BOOT_OFFS
3633 Location in NAND to read U-Boot from
3635 CONFIG_SYS_NAND_U_BOOT_DST
3636 Location in memory to load U-Boot to
3638 CONFIG_SYS_NAND_U_BOOT_SIZE
3639 Size of image to load
3641 CONFIG_SYS_NAND_U_BOOT_START
3642 Entry point in loaded image to jump to
3644 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3645 Define this if you need to first read the OOB and then the
3646 data. This is used, for example, on davinci platforms.
3648 CONFIG_SPL_OMAP3_ID_NAND
3649 Support for an OMAP3-specific set of functions to return the
3650 ID and MFR of the first attached NAND chip, if present.
3652 CONFIG_SPL_SERIAL_SUPPORT
3653 Support for drivers/serial/libserial.o in SPL binary
3655 CONFIG_SPL_SPI_FLASH_SUPPORT
3656 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3658 CONFIG_SPL_SPI_SUPPORT
3659 Support for drivers/spi/libspi.o in SPL binary
3661 CONFIG_SPL_RAM_DEVICE
3662 Support for running image already present in ram, in SPL binary
3664 CONFIG_SPL_LIBGENERIC_SUPPORT
3665 Support for lib/libgeneric.o in SPL binary
3667 CONFIG_SPL_ENV_SUPPORT
3668 Support for the environment operating in SPL binary
3670 CONFIG_SPL_NET_SUPPORT
3671 Support for the net/libnet.o in SPL binary.
3672 It conflicts with SPL env from storage medium specified by
3673 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3676 Image offset to which the SPL should be padded before appending
3677 the SPL payload. By default, this is defined as
3678 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3679 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3680 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3683 Final target image containing SPL and payload. Some SPLs
3684 use an arch-specific makefile fragment instead, for
3685 example if more than one image needs to be produced.
3687 CONFIG_FIT_SPL_PRINT
3688 Printing information about a FIT image adds quite a bit of
3689 code to SPL. So this is normally disabled in SPL. Use this
3690 option to re-enable it. This will affect the output of the
3691 bootm command when booting a FIT image.
3695 Enable building of TPL globally.
3698 Image offset to which the TPL should be padded before appending
3699 the TPL payload. By default, this is defined as
3700 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3701 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3702 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3707 [so far only for SMDK2400 boards]
3709 - Modem support enable:
3710 CONFIG_MODEM_SUPPORT
3712 - RTS/CTS Flow control enable:
3715 - Modem debug support:
3716 CONFIG_MODEM_SUPPORT_DEBUG
3718 Enables debugging stuff (char screen[1024], dbg())
3719 for modem support. Useful only with BDI2000.
3721 - Interrupt support (PPC):
3723 There are common interrupt_init() and timer_interrupt()
3724 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3725 for CPU specific initialization. interrupt_init_cpu()
3726 should set decrementer_count to appropriate value. If
3727 CPU resets decrementer automatically after interrupt
3728 (ppc4xx) it should set decrementer_count to zero.
3729 timer_interrupt() calls timer_interrupt_cpu() for CPU
3730 specific handling. If board has watchdog / status_led
3731 / other_activity_monitor it works automatically from
3732 general timer_interrupt().
3736 In the target system modem support is enabled when a
3737 specific key (key combination) is pressed during
3738 power-on. Otherwise U-Boot will boot normally
3739 (autoboot). The key_pressed() function is called from
3740 board_init(). Currently key_pressed() is a dummy
3741 function, returning 1 and thus enabling modem
3744 If there are no modem init strings in the
3745 environment, U-Boot proceed to autoboot; the
3746 previous output (banner, info printfs) will be
3749 See also: doc/README.Modem
3751 Board initialization settings:
3752 ------------------------------
3754 During Initialization u-boot calls a number of board specific functions
3755 to allow the preparation of board specific prerequisites, e.g. pin setup
3756 before drivers are initialized. To enable these callbacks the
3757 following configuration macros have to be defined. Currently this is
3758 architecture specific, so please check arch/your_architecture/lib/board.c
3759 typically in board_init_f() and board_init_r().
3761 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3762 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3763 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3764 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3766 Configuration Settings:
3767 -----------------------
3769 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3770 Optionally it can be defined to support 64-bit memory commands.
3772 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3773 undefine this when you're short of memory.
3775 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3776 width of the commands listed in the 'help' command output.
3778 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3779 prompt for user input.
3781 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3783 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3785 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3787 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3788 the application (usually a Linux kernel) when it is
3791 - CONFIG_SYS_BAUDRATE_TABLE:
3792 List of legal baudrate settings for this board.
3794 - CONFIG_SYS_CONSOLE_INFO_QUIET
3795 Suppress display of console information at boot.
3797 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3798 If the board specific function
3799 extern int overwrite_console (void);
3800 returns 1, the stdin, stderr and stdout are switched to the
3801 serial port, else the settings in the environment are used.
3803 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3804 Enable the call to overwrite_console().
3806 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3807 Enable overwrite of previous console environment settings.
3809 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3810 Begin and End addresses of the area used by the
3813 - CONFIG_SYS_ALT_MEMTEST:
3814 Enable an alternate, more extensive memory test.
3816 - CONFIG_SYS_MEMTEST_SCRATCH:
3817 Scratch address used by the alternate memory test
3818 You only need to set this if address zero isn't writeable
3820 - CONFIG_SYS_MEM_RESERVE_SECURE
3821 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3822 is substracted from total RAM and won't be reported to OS.
3823 This memory can be used as secure memory. A variable
3824 gd->secure_ram is used to track the location. In systems
3825 the RAM base is not zero, or RAM is divided into banks,
3826 this variable needs to be recalcuated to get the address.
3828 - CONFIG_SYS_MEM_TOP_HIDE:
3829 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3830 this specified memory area will get subtracted from the top
3831 (end) of RAM and won't get "touched" at all by U-Boot. By
3832 fixing up gd->ram_size the Linux kernel should gets passed
3833 the now "corrected" memory size and won't touch it either.
3834 This should work for arch/ppc and arch/powerpc. Only Linux
3835 board ports in arch/powerpc with bootwrapper support that
3836 recalculate the memory size from the SDRAM controller setup
3837 will have to get fixed in Linux additionally.
3839 This option can be used as a workaround for the 440EPx/GRx
3840 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3843 WARNING: Please make sure that this value is a multiple of
3844 the Linux page size (normally 4k). If this is not the case,
3845 then the end address of the Linux memory will be located at a
3846 non page size aligned address and this could cause major
3849 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3850 Enable temporary baudrate change while serial download
3852 - CONFIG_SYS_SDRAM_BASE:
3853 Physical start address of SDRAM. _Must_ be 0 here.
3855 - CONFIG_SYS_MBIO_BASE:
3856 Physical start address of Motherboard I/O (if using a
3859 - CONFIG_SYS_FLASH_BASE:
3860 Physical start address of Flash memory.
3862 - CONFIG_SYS_MONITOR_BASE:
3863 Physical start address of boot monitor code (set by
3864 make config files to be same as the text base address
3865 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3866 CONFIG_SYS_FLASH_BASE when booting from flash.
3868 - CONFIG_SYS_MONITOR_LEN:
3869 Size of memory reserved for monitor code, used to
3870 determine _at_compile_time_ (!) if the environment is
3871 embedded within the U-Boot image, or in a separate
3874 - CONFIG_SYS_MALLOC_LEN:
3875 Size of DRAM reserved for malloc() use.
3877 - CONFIG_SYS_MALLOC_F_LEN
3878 Size of the malloc() pool for use before relocation. If
3879 this is defined, then a very simple malloc() implementation
3880 will become available before relocation. The address is just
3881 below the global data, and the stack is moved down to make
3884 This feature allocates regions with increasing addresses
3885 within the region. calloc() is supported, but realloc()
3886 is not available. free() is supported but does nothing.
3887 The memory will be freed (or in fact just forgotten) when
3888 U-Boot relocates itself.
3890 Pre-relocation malloc() is only supported on ARM and sandbox
3891 at present but is fairly easy to enable for other archs.
3893 - CONFIG_SYS_MALLOC_SIMPLE
3894 Provides a simple and small malloc() and calloc() for those
3895 boards which do not use the full malloc in SPL (which is
3896 enabled with CONFIG_SYS_SPL_MALLOC_START).
3898 - CONFIG_SYS_NONCACHED_MEMORY:
3899 Size of non-cached memory area. This area of memory will be
3900 typically located right below the malloc() area and mapped
3901 uncached in the MMU. This is useful for drivers that would
3902 otherwise require a lot of explicit cache maintenance. For
3903 some drivers it's also impossible to properly maintain the
3904 cache. For example if the regions that need to be flushed
3905 are not a multiple of the cache-line size, *and* padding
3906 cannot be allocated between the regions to align them (i.e.
3907 if the HW requires a contiguous array of regions, and the
3908 size of each region is not cache-aligned), then a flush of
3909 one region may result in overwriting data that hardware has
3910 written to another region in the same cache-line. This can
3911 happen for example in network drivers where descriptors for
3912 buffers are typically smaller than the CPU cache-line (e.g.
3913 16 bytes vs. 32 or 64 bytes).
3915 Non-cached memory is only supported on 32-bit ARM at present.
3917 - CONFIG_SYS_BOOTM_LEN:
3918 Normally compressed uImages are limited to an
3919 uncompressed size of 8 MBytes. If this is not enough,
3920 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3921 to adjust this setting to your needs.
3923 - CONFIG_SYS_BOOTMAPSZ:
3924 Maximum size of memory mapped by the startup code of
3925 the Linux kernel; all data that must be processed by
3926 the Linux kernel (bd_info, boot arguments, FDT blob if
3927 used) must be put below this limit, unless "bootm_low"
3928 environment variable is defined and non-zero. In such case
3929 all data for the Linux kernel must be between "bootm_low"
3930 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3931 variable "bootm_mapsize" will override the value of
3932 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3933 then the value in "bootm_size" will be used instead.
3935 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3936 Enable initrd_high functionality. If defined then the
3937 initrd_high feature is enabled and the bootm ramdisk subcommand
3940 - CONFIG_SYS_BOOT_GET_CMDLINE:
3941 Enables allocating and saving kernel cmdline in space between
3942 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3944 - CONFIG_SYS_BOOT_GET_KBD:
3945 Enables allocating and saving a kernel copy of the bd_info in
3946 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3948 - CONFIG_SYS_MAX_FLASH_BANKS:
3949 Max number of Flash memory banks
3951 - CONFIG_SYS_MAX_FLASH_SECT:
3952 Max number of sectors on a Flash chip
3954 - CONFIG_SYS_FLASH_ERASE_TOUT:
3955 Timeout for Flash erase operations (in ms)
3957 - CONFIG_SYS_FLASH_WRITE_TOUT:
3958 Timeout for Flash write operations (in ms)
3960 - CONFIG_SYS_FLASH_LOCK_TOUT
3961 Timeout for Flash set sector lock bit operation (in ms)
3963 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3964 Timeout for Flash clear lock bits operation (in ms)
3966 - CONFIG_SYS_FLASH_PROTECTION
3967 If defined, hardware flash sectors protection is used
3968 instead of U-Boot software protection.
3970 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3972 Enable TFTP transfers directly to flash memory;
3973 without this option such a download has to be
3974 performed in two steps: (1) download to RAM, and (2)
3975 copy from RAM to flash.
3977 The two-step approach is usually more reliable, since
3978 you can check if the download worked before you erase
3979 the flash, but in some situations (when system RAM is
3980 too limited to allow for a temporary copy of the
3981 downloaded image) this option may be very useful.
3983 - CONFIG_SYS_FLASH_CFI:
3984 Define if the flash driver uses extra elements in the
3985 common flash structure for storing flash geometry.
3987 - CONFIG_FLASH_CFI_DRIVER
3988 This option also enables the building of the cfi_flash driver
3989 in the drivers directory
3991 - CONFIG_FLASH_CFI_MTD
3992 This option enables the building of the cfi_mtd driver
3993 in the drivers directory. The driver exports CFI flash
3996 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3997 Use buffered writes to flash.
3999 - CONFIG_FLASH_SPANSION_S29WS_N
4000 s29ws-n MirrorBit flash has non-standard addresses for buffered
4003 - CONFIG_SYS_FLASH_QUIET_TEST
4004 If this option is defined, the common CFI flash doesn't
4005 print it's warning upon not recognized FLASH banks. This
4006 is useful, if some of the configured banks are only
4007 optionally available.
4009 - CONFIG_FLASH_SHOW_PROGRESS
4010 If defined (must be an integer), print out countdown
4011 digits and dots. Recommended value: 45 (9..1) for 80
4012 column displays, 15 (3..1) for 40 column displays.
4014 - CONFIG_FLASH_VERIFY
4015 If defined, the content of the flash (destination) is compared
4016 against the source after the write operation. An error message
4017 will be printed when the contents are not identical.
4018 Please note that this option is useless in nearly all cases,
4019 since such flash programming errors usually are detected earlier
4020 while unprotecting/erasing/programming. Please only enable
4021 this option if you really know what you are doing.
4023 - CONFIG_SYS_RX_ETH_BUFFER:
4024 Defines the number of Ethernet receive buffers. On some
4025 Ethernet controllers it is recommended to set this value
4026 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4027 buffers can be full shortly after enabling the interface
4028 on high Ethernet traffic.
4029 Defaults to 4 if not defined.
4031 - CONFIG_ENV_MAX_ENTRIES
4033 Maximum number of entries in the hash table that is used
4034 internally to store the environment settings. The default
4035 setting is supposed to be generous and should work in most
4036 cases. This setting can be used to tune behaviour; see
4037 lib/hashtable.c for details.
4039 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4040 - CONFIG_ENV_FLAGS_LIST_STATIC
4041 Enable validation of the values given to environment variables when
4042 calling env set. Variables can be restricted to only decimal,
4043 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4044 the variables can also be restricted to IP address or MAC address.
4046 The format of the list is:
4047 type_attribute = [s|d|x|b|i|m]
4048 access_attribute = [a|r|o|c]
4049 attributes = type_attribute[access_attribute]
4050 entry = variable_name[:attributes]
4053 The type attributes are:
4054 s - String (default)
4057 b - Boolean ([1yYtT|0nNfF])
4061 The access attributes are:
4067 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4068 Define this to a list (string) to define the ".flags"
4069 environment variable in the default or embedded environment.
4071 - CONFIG_ENV_FLAGS_LIST_STATIC
4072 Define this to a list (string) to define validation that
4073 should be done if an entry is not found in the ".flags"
4074 environment variable. To override a setting in the static
4075 list, simply add an entry for the same variable name to the
4078 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4079 regular expression. This allows multiple variables to define the same
4080 flags without explicitly listing them for each variable.
4082 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4083 If defined, don't allow the -f switch to env set override variable
4086 - CONFIG_SYS_GENERIC_BOARD
4087 This selects the architecture-generic board system instead of the
4088 architecture-specific board files. It is intended to move boards
4089 to this new framework over time. Defining this will disable the
4090 arch/foo/lib/board.c file and use common/board_f.c and
4091 common/board_r.c instead. To use this option your architecture
4092 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4093 If you find problems enabling this option on your board please report
4094 the problem and send patches!
4096 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4097 This is set by OMAP boards for the max time that reset should
4098 be asserted. See doc/README.omap-reset-time for details on how
4099 the value can be calculated on a given board.
4102 If stdint.h is available with your toolchain you can define this
4103 option to enable it. You can provide option 'USE_STDINT=1' when
4104 building U-Boot to enable this.
4106 The following definitions that deal with the placement and management
4107 of environment data (variable area); in general, we support the
4108 following configurations:
4110 - CONFIG_BUILD_ENVCRC:
4112 Builds up envcrc with the target environment so that external utils
4113 may easily extract it and embed it in final U-Boot images.
4115 - CONFIG_ENV_IS_IN_FLASH:
4117 Define this if the environment is in flash memory.
4119 a) The environment occupies one whole flash sector, which is
4120 "embedded" in the text segment with the U-Boot code. This
4121 happens usually with "bottom boot sector" or "top boot
4122 sector" type flash chips, which have several smaller
4123 sectors at the start or the end. For instance, such a
4124 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4125 such a case you would place the environment in one of the
4126 4 kB sectors - with U-Boot code before and after it. With
4127 "top boot sector" type flash chips, you would put the
4128 environment in one of the last sectors, leaving a gap
4129 between U-Boot and the environment.
4131 - CONFIG_ENV_OFFSET:
4133 Offset of environment data (variable area) to the
4134 beginning of flash memory; for instance, with bottom boot
4135 type flash chips the second sector can be used: the offset
4136 for this sector is given here.
4138 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4142 This is just another way to specify the start address of
4143 the flash sector containing the environment (instead of
4146 - CONFIG_ENV_SECT_SIZE:
4148 Size of the sector containing the environment.
4151 b) Sometimes flash chips have few, equal sized, BIG sectors.
4152 In such a case you don't want to spend a whole sector for
4157 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4158 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4159 of this flash sector for the environment. This saves
4160 memory for the RAM copy of the environment.
4162 It may also save flash memory if you decide to use this
4163 when your environment is "embedded" within U-Boot code,
4164 since then the remainder of the flash sector could be used
4165 for U-Boot code. It should be pointed out that this is
4166 STRONGLY DISCOURAGED from a robustness point of view:
4167 updating the environment in flash makes it always
4168 necessary to erase the WHOLE sector. If something goes
4169 wrong before the contents has been restored from a copy in
4170 RAM, your target system will be dead.
4172 - CONFIG_ENV_ADDR_REDUND
4173 CONFIG_ENV_SIZE_REDUND
4175 These settings describe a second storage area used to hold
4176 a redundant copy of the environment data, so that there is
4177 a valid backup copy in case there is a power failure during
4178 a "saveenv" operation.
4180 BE CAREFUL! Any changes to the flash layout, and some changes to the
4181 source code will make it necessary to adapt <board>/u-boot.lds*
4185 - CONFIG_ENV_IS_IN_NVRAM:
4187 Define this if you have some non-volatile memory device
4188 (NVRAM, battery buffered SRAM) which you want to use for the
4194 These two #defines are used to determine the memory area you
4195 want to use for environment. It is assumed that this memory
4196 can just be read and written to, without any special
4199 BE CAREFUL! The first access to the environment happens quite early
4200 in U-Boot initialization (when we try to get the setting of for the
4201 console baudrate). You *MUST* have mapped your NVRAM area then, or
4204 Please note that even with NVRAM we still use a copy of the
4205 environment in RAM: we could work on NVRAM directly, but we want to
4206 keep settings there always unmodified except somebody uses "saveenv"
4207 to save the current settings.
4210 - CONFIG_ENV_IS_IN_EEPROM:
4212 Use this if you have an EEPROM or similar serial access
4213 device and a driver for it.
4215 - CONFIG_ENV_OFFSET:
4218 These two #defines specify the offset and size of the
4219 environment area within the total memory of your EEPROM.
4221 - CONFIG_SYS_I2C_EEPROM_ADDR:
4222 If defined, specified the chip address of the EEPROM device.
4223 The default address is zero.
4225 - CONFIG_SYS_I2C_EEPROM_BUS:
4226 If defined, specified the i2c bus of the EEPROM device.
4228 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4229 If defined, the number of bits used to address bytes in a
4230 single page in the EEPROM device. A 64 byte page, for example
4231 would require six bits.
4233 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4234 If defined, the number of milliseconds to delay between
4235 page writes. The default is zero milliseconds.
4237 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4238 The length in bytes of the EEPROM memory array address. Note
4239 that this is NOT the chip address length!
4241 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4242 EEPROM chips that implement "address overflow" are ones
4243 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4244 address and the extra bits end up in the "chip address" bit
4245 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4248 Note that we consider the length of the address field to
4249 still be one byte because the extra address bits are hidden
4250 in the chip address.
4252 - CONFIG_SYS_EEPROM_SIZE:
4253 The size in bytes of the EEPROM device.
4255 - CONFIG_ENV_EEPROM_IS_ON_I2C
4256 define this, if you have I2C and SPI activated, and your
4257 EEPROM, which holds the environment, is on the I2C bus.
4259 - CONFIG_I2C_ENV_EEPROM_BUS
4260 if you have an Environment on an EEPROM reached over
4261 I2C muxes, you can define here, how to reach this
4262 EEPROM. For example:
4264 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4266 EEPROM which holds the environment, is reached over
4267 a pca9547 i2c mux with address 0x70, channel 3.
4269 - CONFIG_ENV_IS_IN_DATAFLASH:
4271 Define this if you have a DataFlash memory device which you
4272 want to use for the environment.
4274 - CONFIG_ENV_OFFSET:
4278 These three #defines specify the offset and size of the
4279 environment area within the total memory of your DataFlash placed
4280 at the specified address.
4282 - CONFIG_ENV_IS_IN_SPI_FLASH:
4284 Define this if you have a SPI Flash memory device which you
4285 want to use for the environment.
4287 - CONFIG_ENV_OFFSET:
4290 These two #defines specify the offset and size of the
4291 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4292 aligned to an erase sector boundary.
4294 - CONFIG_ENV_SECT_SIZE:
4296 Define the SPI flash's sector size.
4298 - CONFIG_ENV_OFFSET_REDUND (optional):
4300 This setting describes a second storage area of CONFIG_ENV_SIZE
4301 size used to hold a redundant copy of the environment data, so
4302 that there is a valid backup copy in case there is a power failure
4303 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4304 aligned to an erase sector boundary.
4306 - CONFIG_ENV_SPI_BUS (optional):
4307 - CONFIG_ENV_SPI_CS (optional):
4309 Define the SPI bus and chip select. If not defined they will be 0.
4311 - CONFIG_ENV_SPI_MAX_HZ (optional):
4313 Define the SPI max work clock. If not defined then use 1MHz.
4315 - CONFIG_ENV_SPI_MODE (optional):
4317 Define the SPI work mode. If not defined then use SPI_MODE_3.
4319 - CONFIG_ENV_IS_IN_REMOTE:
4321 Define this if you have a remote memory space which you
4322 want to use for the local device's environment.
4327 These two #defines specify the address and size of the
4328 environment area within the remote memory space. The
4329 local device can get the environment from remote memory
4330 space by SRIO or PCIE links.
4332 BE CAREFUL! For some special cases, the local device can not use
4333 "saveenv" command. For example, the local device will get the
4334 environment stored in a remote NOR flash by SRIO or PCIE link,
4335 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4337 - CONFIG_ENV_IS_IN_NAND:
4339 Define this if you have a NAND device which you want to use
4340 for the environment.
4342 - CONFIG_ENV_OFFSET:
4345 These two #defines specify the offset and size of the environment
4346 area within the first NAND device. CONFIG_ENV_OFFSET must be
4347 aligned to an erase block boundary.
4349 - CONFIG_ENV_OFFSET_REDUND (optional):
4351 This setting describes a second storage area of CONFIG_ENV_SIZE
4352 size used to hold a redundant copy of the environment data, so
4353 that there is a valid backup copy in case there is a power failure
4354 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4355 aligned to an erase block boundary.
4357 - CONFIG_ENV_RANGE (optional):
4359 Specifies the length of the region in which the environment
4360 can be written. This should be a multiple of the NAND device's
4361 block size. Specifying a range with more erase blocks than
4362 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4363 the range to be avoided.
4365 - CONFIG_ENV_OFFSET_OOB (optional):
4367 Enables support for dynamically retrieving the offset of the
4368 environment from block zero's out-of-band data. The
4369 "nand env.oob" command can be used to record this offset.
4370 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4371 using CONFIG_ENV_OFFSET_OOB.
4373 - CONFIG_NAND_ENV_DST
4375 Defines address in RAM to which the nand_spl code should copy the
4376 environment. If redundant environment is used, it will be copied to
4377 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4379 - CONFIG_ENV_IS_IN_UBI:
4381 Define this if you have an UBI volume that you want to use for the
4382 environment. This has the benefit of wear-leveling the environment
4383 accesses, which is important on NAND.
4385 - CONFIG_ENV_UBI_PART:
4387 Define this to a string that is the mtd partition containing the UBI.
4389 - CONFIG_ENV_UBI_VOLUME:
4391 Define this to the name of the volume that you want to store the
4394 - CONFIG_ENV_UBI_VOLUME_REDUND:
4396 Define this to the name of another volume to store a second copy of
4397 the environment in. This will enable redundant environments in UBI.
4398 It is assumed that both volumes are in the same MTD partition.
4400 - CONFIG_UBI_SILENCE_MSG
4401 - CONFIG_UBIFS_SILENCE_MSG
4403 You will probably want to define these to avoid a really noisy system
4404 when storing the env in UBI.
4406 - CONFIG_ENV_IS_IN_FAT:
4407 Define this if you want to use the FAT file system for the environment.
4409 - FAT_ENV_INTERFACE:
4411 Define this to a string that is the name of the block device.
4413 - FAT_ENV_DEV_AND_PART:
4415 Define this to a string to specify the partition of the device. It can
4418 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4419 - "D:P": device D partition P. Error occurs if device D has no
4422 - "D" or "D:": device D partition 1 if device D has partition
4423 table, or the whole device D if has no partition
4425 - "D:auto": first partition in device D with bootable flag set.
4426 If none, first valid partition in device D. If no
4427 partition table then means device D.
4431 It's a string of the FAT file name. This file use to store the
4435 This should be defined. Otherwise it cannot save the environment file.
4437 - CONFIG_ENV_IS_IN_MMC:
4439 Define this if you have an MMC device which you want to use for the
4442 - CONFIG_SYS_MMC_ENV_DEV:
4444 Specifies which MMC device the environment is stored in.
4446 - CONFIG_SYS_MMC_ENV_PART (optional):
4448 Specifies which MMC partition the environment is stored in. If not
4449 set, defaults to partition 0, the user area. Common values might be
4450 1 (first MMC boot partition), 2 (second MMC boot partition).
4452 - CONFIG_ENV_OFFSET:
4455 These two #defines specify the offset and size of the environment
4456 area within the specified MMC device.
4458 If offset is positive (the usual case), it is treated as relative to
4459 the start of the MMC partition. If offset is negative, it is treated
4460 as relative to the end of the MMC partition. This can be useful if
4461 your board may be fitted with different MMC devices, which have
4462 different sizes for the MMC partitions, and you always want the
4463 environment placed at the very end of the partition, to leave the
4464 maximum possible space before it, to store other data.
4466 These two values are in units of bytes, but must be aligned to an
4467 MMC sector boundary.
4469 - CONFIG_ENV_OFFSET_REDUND (optional):
4471 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4472 hold a redundant copy of the environment data. This provides a
4473 valid backup copy in case the other copy is corrupted, e.g. due
4474 to a power failure during a "saveenv" operation.
4476 This value may also be positive or negative; this is handled in the
4477 same way as CONFIG_ENV_OFFSET.
4479 This value is also in units of bytes, but must also be aligned to
4480 an MMC sector boundary.
4482 - CONFIG_ENV_SIZE_REDUND (optional):
4484 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4485 set. If this value is set, it must be set to the same value as
4488 - CONFIG_SYS_SPI_INIT_OFFSET
4490 Defines offset to the initial SPI buffer area in DPRAM. The
4491 area is used at an early stage (ROM part) if the environment
4492 is configured to reside in the SPI EEPROM: We need a 520 byte
4493 scratch DPRAM area. It is used between the two initialization
4494 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4495 to be a good choice since it makes it far enough from the
4496 start of the data area as well as from the stack pointer.
4498 Please note that the environment is read-only until the monitor
4499 has been relocated to RAM and a RAM copy of the environment has been
4500 created; also, when using EEPROM you will have to use getenv_f()
4501 until then to read environment variables.
4503 The environment is protected by a CRC32 checksum. Before the monitor
4504 is relocated into RAM, as a result of a bad CRC you will be working
4505 with the compiled-in default environment - *silently*!!! [This is
4506 necessary, because the first environment variable we need is the
4507 "baudrate" setting for the console - if we have a bad CRC, we don't
4508 have any device yet where we could complain.]
4510 Note: once the monitor has been relocated, then it will complain if
4511 the default environment is used; a new CRC is computed as soon as you
4512 use the "saveenv" command to store a valid environment.
4514 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4515 Echo the inverted Ethernet link state to the fault LED.
4517 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4518 also needs to be defined.
4520 - CONFIG_SYS_FAULT_MII_ADDR:
4521 MII address of the PHY to check for the Ethernet link state.
4523 - CONFIG_NS16550_MIN_FUNCTIONS:
4524 Define this if you desire to only have use of the NS16550_init
4525 and NS16550_putc functions for the serial driver located at
4526 drivers/serial/ns16550.c. This option is useful for saving
4527 space for already greatly restricted images, including but not
4528 limited to NAND_SPL configurations.
4530 - CONFIG_DISPLAY_BOARDINFO
4531 Display information about the board that U-Boot is running on
4532 when U-Boot starts up. The board function checkboard() is called
4535 - CONFIG_DISPLAY_BOARDINFO_LATE
4536 Similar to the previous option, but display this information
4537 later, once stdio is running and output goes to the LCD, if
4540 - CONFIG_BOARD_SIZE_LIMIT:
4541 Maximum size of the U-Boot image. When defined, the
4542 build system checks that the actual size does not
4545 Low Level (hardware related) configuration options:
4546 ---------------------------------------------------
4548 - CONFIG_SYS_CACHELINE_SIZE:
4549 Cache Line Size of the CPU.
4551 - CONFIG_SYS_DEFAULT_IMMR:
4552 Default address of the IMMR after system reset.
4554 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4555 and RPXsuper) to be able to adjust the position of
4556 the IMMR register after a reset.
4558 - CONFIG_SYS_CCSRBAR_DEFAULT:
4559 Default (power-on reset) physical address of CCSR on Freescale
4562 - CONFIG_SYS_CCSRBAR:
4563 Virtual address of CCSR. On a 32-bit build, this is typically
4564 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4566 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4567 for cross-platform code that uses that macro instead.
4569 - CONFIG_SYS_CCSRBAR_PHYS:
4570 Physical address of CCSR. CCSR can be relocated to a new
4571 physical address, if desired. In this case, this macro should
4572 be set to that address. Otherwise, it should be set to the
4573 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4574 is typically relocated on 36-bit builds. It is recommended
4575 that this macro be defined via the _HIGH and _LOW macros:
4577 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4578 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4580 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4581 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4582 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4583 used in assembly code, so it must not contain typecasts or
4584 integer size suffixes (e.g. "ULL").
4586 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4587 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4588 used in assembly code, so it must not contain typecasts or
4589 integer size suffixes (e.g. "ULL").
4591 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4592 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4593 forced to a value that ensures that CCSR is not relocated.
4595 - Floppy Disk Support:
4596 CONFIG_SYS_FDC_DRIVE_NUMBER
4598 the default drive number (default value 0)
4600 CONFIG_SYS_ISA_IO_STRIDE
4602 defines the spacing between FDC chipset registers
4605 CONFIG_SYS_ISA_IO_OFFSET
4607 defines the offset of register from address. It
4608 depends on which part of the data bus is connected to
4609 the FDC chipset. (default value 0)
4611 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4612 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4615 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4616 fdc_hw_init() is called at the beginning of the FDC
4617 setup. fdc_hw_init() must be provided by the board
4618 source code. It is used to make hardware-dependent
4622 Most IDE controllers were designed to be connected with PCI
4623 interface. Only few of them were designed for AHB interface.
4624 When software is doing ATA command and data transfer to
4625 IDE devices through IDE-AHB controller, some additional
4626 registers accessing to these kind of IDE-AHB controller
4629 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4630 DO NOT CHANGE unless you know exactly what you're
4631 doing! (11-4) [MPC8xx/82xx systems only]
4633 - CONFIG_SYS_INIT_RAM_ADDR:
4635 Start address of memory area that can be used for
4636 initial data and stack; please note that this must be
4637 writable memory that is working WITHOUT special
4638 initialization, i. e. you CANNOT use normal RAM which
4639 will become available only after programming the
4640 memory controller and running certain initialization
4643 U-Boot uses the following memory types:
4644 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4645 - MPC824X: data cache
4646 - PPC4xx: data cache
4648 - CONFIG_SYS_GBL_DATA_OFFSET:
4650 Offset of the initial data structure in the memory
4651 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4652 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4653 data is located at the end of the available space
4654 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4655 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4656 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4657 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4660 On the MPC824X (or other systems that use the data
4661 cache for initial memory) the address chosen for
4662 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4663 point to an otherwise UNUSED address space between
4664 the top of RAM and the start of the PCI space.
4666 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4668 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4670 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4672 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4674 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4676 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4678 - CONFIG_SYS_OR_TIMING_SDRAM:
4681 - CONFIG_SYS_MAMR_PTA:
4682 periodic timer for refresh
4684 - CONFIG_SYS_DER: Debug Event Register (37-47)
4686 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4687 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4688 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4689 CONFIG_SYS_BR1_PRELIM:
4690 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4692 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4693 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4694 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4695 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4697 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4698 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4699 Machine Mode Register and Memory Periodic Timer
4700 Prescaler definitions (SDRAM timing)
4702 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4703 enable I2C microcode relocation patch (MPC8xx);
4704 define relocation offset in DPRAM [DSP2]
4706 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4707 enable SMC microcode relocation patch (MPC8xx);
4708 define relocation offset in DPRAM [SMC1]
4710 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4711 enable SPI microcode relocation patch (MPC8xx);
4712 define relocation offset in DPRAM [SCC4]
4714 - CONFIG_SYS_USE_OSCCLK:
4715 Use OSCM clock mode on MBX8xx board. Be careful,
4716 wrong setting might damage your board. Read
4717 doc/README.MBX before setting this variable!
4719 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4720 Offset of the bootmode word in DPRAM used by post
4721 (Power On Self Tests). This definition overrides
4722 #define'd default value in commproc.h resp.
4725 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4726 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4727 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4728 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4729 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4730 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4731 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4732 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4733 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4735 - CONFIG_PCI_DISABLE_PCIE:
4736 Disable PCI-Express on systems where it is supported but not
4739 - CONFIG_PCI_ENUM_ONLY
4740 Only scan through and get the devices on the buses.
4741 Don't do any setup work, presumably because someone or
4742 something has already done it, and we don't need to do it
4743 a second time. Useful for platforms that are pre-booted
4744 by coreboot or similar.
4746 - CONFIG_PCI_INDIRECT_BRIDGE:
4747 Enable support for indirect PCI bridges.
4750 Chip has SRIO or not
4753 Board has SRIO 1 port available
4756 Board has SRIO 2 port available
4758 - CONFIG_SRIO_PCIE_BOOT_MASTER
4759 Board can support master function for Boot from SRIO and PCIE
4761 - CONFIG_SYS_SRIOn_MEM_VIRT:
4762 Virtual Address of SRIO port 'n' memory region
4764 - CONFIG_SYS_SRIOn_MEM_PHYS:
4765 Physical Address of SRIO port 'n' memory region
4767 - CONFIG_SYS_SRIOn_MEM_SIZE:
4768 Size of SRIO port 'n' memory region
4770 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4771 Defined to tell the NAND controller that the NAND chip is using
4773 Not all NAND drivers use this symbol.
4774 Example of drivers that use it:
4775 - drivers/mtd/nand/ndfc.c
4776 - drivers/mtd/nand/mxc_nand.c
4778 - CONFIG_SYS_NDFC_EBC0_CFG
4779 Sets the EBC0_CFG register for the NDFC. If not defined
4780 a default value will be used.
4783 Get DDR timing information from an I2C EEPROM. Common
4784 with pluggable memory modules such as SODIMMs
4787 I2C address of the SPD EEPROM
4789 - CONFIG_SYS_SPD_BUS_NUM
4790 If SPD EEPROM is on an I2C bus other than the first
4791 one, specify here. Note that the value must resolve
4792 to something your driver can deal with.
4794 - CONFIG_SYS_DDR_RAW_TIMING
4795 Get DDR timing information from other than SPD. Common with
4796 soldered DDR chips onboard without SPD. DDR raw timing
4797 parameters are extracted from datasheet and hard-coded into
4798 header files or board specific files.
4800 - CONFIG_FSL_DDR_INTERACTIVE
4801 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4803 - CONFIG_FSL_DDR_SYNC_REFRESH
4804 Enable sync of refresh for multiple controllers.
4806 - CONFIG_FSL_DDR_BIST
4807 Enable built-in memory test for Freescale DDR controllers.
4809 - CONFIG_SYS_83XX_DDR_USES_CS0
4810 Only for 83xx systems. If specified, then DDR should
4811 be configured using CS0 and CS1 instead of CS2 and CS3.
4813 - CONFIG_ETHER_ON_FEC[12]
4814 Define to enable FEC[12] on a 8xx series processor.
4816 - CONFIG_FEC[12]_PHY
4817 Define to the hardcoded PHY address which corresponds
4818 to the given FEC; i. e.
4819 #define CONFIG_FEC1_PHY 4
4820 means that the PHY with address 4 is connected to FEC1
4822 When set to -1, means to probe for first available.
4824 - CONFIG_FEC[12]_PHY_NORXERR
4825 The PHY does not have a RXERR line (RMII only).
4826 (so program the FEC to ignore it).
4829 Enable RMII mode for all FECs.
4830 Note that this is a global option, we can't
4831 have one FEC in standard MII mode and another in RMII mode.
4833 - CONFIG_CRC32_VERIFY
4834 Add a verify option to the crc32 command.
4837 => crc32 -v <address> <count> <crc32>
4839 Where address/count indicate a memory area
4840 and crc32 is the correct crc32 which the
4844 Add the "loopw" memory command. This only takes effect if
4845 the memory commands are activated globally (CONFIG_CMD_MEM).
4848 Add the "mdc" and "mwc" memory commands. These are cyclic
4853 This command will print 4 bytes (10,11,12,13) each 500 ms.
4855 => mwc.l 100 12345678 10
4856 This command will write 12345678 to address 100 all 10 ms.
4858 This only takes effect if the memory commands are activated
4859 globally (CONFIG_CMD_MEM).
4861 - CONFIG_SKIP_LOWLEVEL_INIT
4862 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4863 low level initializations (like setting up the memory
4864 controller) are omitted and/or U-Boot does not
4865 relocate itself into RAM.
4867 Normally this variable MUST NOT be defined. The only
4868 exception is when U-Boot is loaded (to RAM) by some
4869 other boot loader or by a debugger which performs
4870 these initializations itself.
4873 Modifies the behaviour of start.S when compiling a loader
4874 that is executed before the actual U-Boot. E.g. when
4875 compiling a NAND SPL.
4878 Modifies the behaviour of start.S when compiling a loader
4879 that is executed after the SPL and before the actual U-Boot.
4880 It is loaded by the SPL.
4882 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4883 Only for 85xx systems. If this variable is specified, the section
4884 .resetvec is not kept and the section .bootpg is placed in the
4885 previous 4k of the .text section.
4887 - CONFIG_ARCH_MAP_SYSMEM
4888 Generally U-Boot (and in particular the md command) uses
4889 effective address. It is therefore not necessary to regard
4890 U-Boot address as virtual addresses that need to be translated
4891 to physical addresses. However, sandbox requires this, since
4892 it maintains its own little RAM buffer which contains all
4893 addressable memory. This option causes some memory accesses
4894 to be mapped through map_sysmem() / unmap_sysmem().
4896 - CONFIG_USE_ARCH_MEMCPY
4897 CONFIG_USE_ARCH_MEMSET
4898 If these options are used a optimized version of memcpy/memset will
4899 be used if available. These functions may be faster under some
4900 conditions but may increase the binary size.
4902 - CONFIG_X86_RESET_VECTOR
4903 If defined, the x86 reset vector code is included. This is not
4904 needed when U-Boot is running from Coreboot.
4907 Defines the MPU clock speed (in MHz).
4909 NOTE : currently only supported on AM335x platforms.
4911 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4912 Enables the RTC32K OSC on AM33xx based plattforms
4914 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4915 Option to disable subpage write in NAND driver
4916 driver that uses this:
4917 drivers/mtd/nand/davinci_nand.c
4919 Freescale QE/FMAN Firmware Support:
4920 -----------------------------------
4922 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4923 loading of "firmware", which is encoded in the QE firmware binary format.
4924 This firmware often needs to be loaded during U-Boot booting, so macros
4925 are used to identify the storage device (NOR flash, SPI, etc) and the address
4928 - CONFIG_SYS_FMAN_FW_ADDR
4929 The address in the storage device where the FMAN microcode is located. The
4930 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4933 - CONFIG_SYS_QE_FW_ADDR
4934 The address in the storage device where the QE microcode is located. The
4935 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4938 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4939 The maximum possible size of the firmware. The firmware binary format
4940 has a field that specifies the actual size of the firmware, but it
4941 might not be possible to read any part of the firmware unless some
4942 local storage is allocated to hold the entire firmware first.
4944 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4945 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4946 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4947 virtual address in NOR flash.
4949 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4950 Specifies that QE/FMAN firmware is located in NAND flash.
4951 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4953 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4954 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4955 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4957 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4958 Specifies that QE/FMAN firmware is located on the primary SPI
4959 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4961 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4962 Specifies that QE/FMAN firmware is located in the remote (master)
4963 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4964 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4965 window->master inbound window->master LAW->the ucode address in
4966 master's memory space.
4968 Freescale Layerscape Management Complex Firmware Support:
4969 ---------------------------------------------------------
4970 The Freescale Layerscape Management Complex (MC) supports the loading of
4972 This firmware often needs to be loaded during U-Boot booting, so macros
4973 are used to identify the storage device (NOR flash, SPI, etc) and the address
4976 - CONFIG_FSL_MC_ENET
4977 Enable the MC driver for Layerscape SoCs.
4979 - CONFIG_SYS_LS_MC_FW_ADDR
4980 The address in the storage device where the firmware is located. The
4981 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4984 - CONFIG_SYS_LS_MC_FW_LENGTH
4985 The maximum possible size of the firmware. The firmware binary format
4986 has a field that specifies the actual size of the firmware, but it
4987 might not be possible to read any part of the firmware unless some
4988 local storage is allocated to hold the entire firmware first.
4990 - CONFIG_SYS_LS_MC_FW_IN_NOR
4991 Specifies that MC firmware is located in NOR flash, mapped as
4992 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4993 virtual address in NOR flash.
4995 Freescale Layerscape Debug Server Support:
4996 -------------------------------------------
4997 The Freescale Layerscape Debug Server Support supports the loading of
4998 "Debug Server firmware" and triggering SP boot-rom.
4999 This firmware often needs to be loaded during U-Boot booting.
5001 - CONFIG_FSL_DEBUG_SERVER
5002 Enable the Debug Server for Layerscape SoCs.
5004 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5005 Define minimum DDR size required for debug server image
5007 - CONFIG_SYS_MC_RSV_MEM_ALIGN
5008 Define alignment of reserved memory MC requires
5013 In order to achieve reproducible builds, timestamps used in the U-Boot build
5014 process have to be set to a fixed value.
5016 This is done using the SOURCE_DATE_EPOCH environment variable.
5017 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5018 option for U-Boot or an environment variable in U-Boot.
5020 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5022 Building the Software:
5023 ======================
5025 Building U-Boot has been tested in several native build environments
5026 and in many different cross environments. Of course we cannot support
5027 all possibly existing versions of cross development tools in all
5028 (potentially obsolete) versions. In case of tool chain problems we
5029 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5030 which is extensively used to build and test U-Boot.
5032 If you are not using a native environment, it is assumed that you
5033 have GNU cross compiling tools available in your path. In this case,
5034 you must set the environment variable CROSS_COMPILE in your shell.
5035 Note that no changes to the Makefile or any other source files are
5036 necessary. For example using the ELDK on a 4xx CPU, please enter:
5038 $ CROSS_COMPILE=ppc_4xx-
5039 $ export CROSS_COMPILE
5041 Note: If you wish to generate Windows versions of the utilities in
5042 the tools directory you can use the MinGW toolchain
5043 (http://www.mingw.org). Set your HOST tools to the MinGW
5044 toolchain and execute 'make tools'. For example:
5046 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5048 Binaries such as tools/mkimage.exe will be created which can
5049 be executed on computers running Windows.
5051 U-Boot is intended to be simple to build. After installing the
5052 sources you must configure U-Boot for one specific board type. This
5057 where "NAME_defconfig" is the name of one of the existing configu-
5058 rations; see boards.cfg for supported names.
5060 Note: for some board special configuration names may exist; check if
5061 additional information is available from the board vendor; for
5062 instance, the TQM823L systems are available without (standard)
5063 or with LCD support. You can select such additional "features"
5064 when choosing the configuration, i. e.
5066 make TQM823L_defconfig
5067 - will configure for a plain TQM823L, i. e. no LCD support
5069 make TQM823L_LCD_defconfig
5070 - will configure for a TQM823L with U-Boot console on LCD
5075 Finally, type "make all", and you should get some working U-Boot
5076 images ready for download to / installation on your system:
5078 - "u-boot.bin" is a raw binary image
5079 - "u-boot" is an image in ELF binary format
5080 - "u-boot.srec" is in Motorola S-Record format
5082 By default the build is performed locally and the objects are saved
5083 in the source directory. One of the two methods can be used to change
5084 this behavior and build U-Boot to some external directory:
5086 1. Add O= to the make command line invocations:
5088 make O=/tmp/build distclean
5089 make O=/tmp/build NAME_defconfig
5090 make O=/tmp/build all
5092 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5094 export KBUILD_OUTPUT=/tmp/build
5099 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5103 Please be aware that the Makefiles assume you are using GNU make, so
5104 for instance on NetBSD you might need to use "gmake" instead of
5108 If the system board that you have is not listed, then you will need
5109 to port U-Boot to your hardware platform. To do this, follow these
5112 1. Create a new directory to hold your board specific code. Add any
5113 files you need. In your board directory, you will need at least
5114 the "Makefile" and a "<board>.c".
5115 2. Create a new configuration file "include/configs/<board>.h" for
5117 3. If you're porting U-Boot to a new CPU, then also create a new
5118 directory to hold your CPU specific code. Add any files you need.
5119 4. Run "make <board>_defconfig" with your new name.
5120 5. Type "make", and you should get a working "u-boot.srec" file
5121 to be installed on your target system.
5122 6. Debug and solve any problems that might arise.
5123 [Of course, this last step is much harder than it sounds.]
5126 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5127 ==============================================================
5129 If you have modified U-Boot sources (for instance added a new board
5130 or support for new devices, a new CPU, etc.) you are expected to
5131 provide feedback to the other developers. The feedback normally takes
5132 the form of a "patch", i. e. a context diff against a certain (latest
5133 official or latest in the git repository) version of U-Boot sources.
5135 But before you submit such a patch, please verify that your modifi-
5136 cation did not break existing code. At least make sure that *ALL* of
5137 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5138 just run the "MAKEALL" script, which will configure and build U-Boot
5139 for ALL supported system. Be warned, this will take a while. You can
5140 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5141 environment variable to the script, i. e. to use the ELDK cross tools
5144 CROSS_COMPILE=ppc_8xx- MAKEALL
5146 or to build on a native PowerPC system you can type
5148 CROSS_COMPILE=' ' MAKEALL
5150 When using the MAKEALL script, the default behaviour is to build
5151 U-Boot in the source directory. This location can be changed by
5152 setting the BUILD_DIR environment variable. Also, for each target
5153 built, the MAKEALL script saves two log files (<target>.ERR and
5154 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5155 location can be changed by setting the MAKEALL_LOGDIR environment
5156 variable. For example:
5158 export BUILD_DIR=/tmp/build
5159 export MAKEALL_LOGDIR=/tmp/log
5160 CROSS_COMPILE=ppc_8xx- MAKEALL
5162 With the above settings build objects are saved in the /tmp/build,
5163 log files are saved in the /tmp/log and the source tree remains clean
5164 during the whole build process.
5167 See also "U-Boot Porting Guide" below.
5170 Monitor Commands - Overview:
5171 ============================
5173 go - start application at address 'addr'
5174 run - run commands in an environment variable
5175 bootm - boot application image from memory
5176 bootp - boot image via network using BootP/TFTP protocol
5177 bootz - boot zImage from memory
5178 tftpboot- boot image via network using TFTP protocol
5179 and env variables "ipaddr" and "serverip"
5180 (and eventually "gatewayip")
5181 tftpput - upload a file via network using TFTP protocol
5182 rarpboot- boot image via network using RARP/TFTP protocol
5183 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5184 loads - load S-Record file over serial line
5185 loadb - load binary file over serial line (kermit mode)
5187 mm - memory modify (auto-incrementing)
5188 nm - memory modify (constant address)
5189 mw - memory write (fill)
5191 cmp - memory compare
5192 crc32 - checksum calculation
5193 i2c - I2C sub-system
5194 sspi - SPI utility commands
5195 base - print or set address offset
5196 printenv- print environment variables
5197 setenv - set environment variables
5198 saveenv - save environment variables to persistent storage
5199 protect - enable or disable FLASH write protection
5200 erase - erase FLASH memory
5201 flinfo - print FLASH memory information
5202 nand - NAND memory operations (see doc/README.nand)
5203 bdinfo - print Board Info structure
5204 iminfo - print header information for application image
5205 coninfo - print console devices and informations
5206 ide - IDE sub-system
5207 loop - infinite loop on address range
5208 loopw - infinite write loop on address range
5209 mtest - simple RAM test
5210 icache - enable or disable instruction cache
5211 dcache - enable or disable data cache
5212 reset - Perform RESET of the CPU
5213 echo - echo args to console
5214 version - print monitor version
5215 help - print online help
5216 ? - alias for 'help'
5219 Monitor Commands - Detailed Description:
5220 ========================================
5224 For now: just type "help <command>".
5227 Environment Variables:
5228 ======================
5230 U-Boot supports user configuration using Environment Variables which
5231 can be made persistent by saving to Flash memory.
5233 Environment Variables are set using "setenv", printed using
5234 "printenv", and saved to Flash using "saveenv". Using "setenv"
5235 without a value can be used to delete a variable from the
5236 environment. As long as you don't save the environment you are
5237 working with an in-memory copy. In case the Flash area containing the
5238 environment is erased by accident, a default environment is provided.
5240 Some configuration options can be set using Environment Variables.
5242 List of environment variables (most likely not complete):
5244 baudrate - see CONFIG_BAUDRATE
5246 bootdelay - see CONFIG_BOOTDELAY
5248 bootcmd - see CONFIG_BOOTCOMMAND
5250 bootargs - Boot arguments when booting an RTOS image
5252 bootfile - Name of the image to load with TFTP
5254 bootm_low - Memory range available for image processing in the bootm
5255 command can be restricted. This variable is given as
5256 a hexadecimal number and defines lowest address allowed
5257 for use by the bootm command. See also "bootm_size"
5258 environment variable. Address defined by "bootm_low" is
5259 also the base of the initial memory mapping for the Linux
5260 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5263 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5264 This variable is given as a hexadecimal number and it
5265 defines the size of the memory region starting at base
5266 address bootm_low that is accessible by the Linux kernel
5267 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5268 as the default value if it is defined, and bootm_size is
5271 bootm_size - Memory range available for image processing in the bootm
5272 command can be restricted. This variable is given as
5273 a hexadecimal number and defines the size of the region
5274 allowed for use by the bootm command. See also "bootm_low"
5275 environment variable.
5277 updatefile - Location of the software update file on a TFTP server, used
5278 by the automatic software update feature. Please refer to
5279 documentation in doc/README.update for more details.
5281 autoload - if set to "no" (any string beginning with 'n'),
5282 "bootp" will just load perform a lookup of the
5283 configuration from the BOOTP server, but not try to
5284 load any image using TFTP
5286 autostart - if set to "yes", an image loaded using the "bootp",
5287 "rarpboot", "tftpboot" or "diskboot" commands will
5288 be automatically started (by internally calling
5291 If set to "no", a standalone image passed to the
5292 "bootm" command will be copied to the load address
5293 (and eventually uncompressed), but NOT be started.
5294 This can be used to load and uncompress arbitrary
5297 fdt_high - if set this restricts the maximum address that the
5298 flattened device tree will be copied into upon boot.
5299 For example, if you have a system with 1 GB memory
5300 at physical address 0x10000000, while Linux kernel
5301 only recognizes the first 704 MB as low memory, you
5302 may need to set fdt_high as 0x3C000000 to have the
5303 device tree blob be copied to the maximum address
5304 of the 704 MB low memory, so that Linux kernel can
5305 access it during the boot procedure.
5307 If this is set to the special value 0xFFFFFFFF then
5308 the fdt will not be copied at all on boot. For this
5309 to work it must reside in writable memory, have
5310 sufficient padding on the end of it for u-boot to
5311 add the information it needs into it, and the memory
5312 must be accessible by the kernel.
5314 fdtcontroladdr- if set this is the address of the control flattened
5315 device tree used by U-Boot when CONFIG_OF_CONTROL is
5318 i2cfast - (PPC405GP|PPC405EP only)
5319 if set to 'y' configures Linux I2C driver for fast
5320 mode (400kHZ). This environment variable is used in
5321 initialization code. So, for changes to be effective
5322 it must be saved and board must be reset.
5324 initrd_high - restrict positioning of initrd images:
5325 If this variable is not set, initrd images will be
5326 copied to the highest possible address in RAM; this
5327 is usually what you want since it allows for
5328 maximum initrd size. If for some reason you want to
5329 make sure that the initrd image is loaded below the
5330 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5331 variable to a value of "no" or "off" or "0".
5332 Alternatively, you can set it to a maximum upper
5333 address to use (U-Boot will still check that it
5334 does not overwrite the U-Boot stack and data).
5336 For instance, when you have a system with 16 MB
5337 RAM, and want to reserve 4 MB from use by Linux,
5338 you can do this by adding "mem=12M" to the value of
5339 the "bootargs" variable. However, now you must make
5340 sure that the initrd image is placed in the first
5341 12 MB as well - this can be done with
5343 setenv initrd_high 00c00000
5345 If you set initrd_high to 0xFFFFFFFF, this is an
5346 indication to U-Boot that all addresses are legal
5347 for the Linux kernel, including addresses in flash
5348 memory. In this case U-Boot will NOT COPY the
5349 ramdisk at all. This may be useful to reduce the
5350 boot time on your system, but requires that this
5351 feature is supported by your Linux kernel.
5353 ipaddr - IP address; needed for tftpboot command
5355 loadaddr - Default load address for commands like "bootp",
5356 "rarpboot", "tftpboot", "loadb" or "diskboot"
5358 loads_echo - see CONFIG_LOADS_ECHO
5360 serverip - TFTP server IP address; needed for tftpboot command
5362 bootretry - see CONFIG_BOOT_RETRY_TIME
5364 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5366 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5368 ethprime - controls which interface is used first.
5370 ethact - controls which interface is currently active.
5371 For example you can do the following
5373 => setenv ethact FEC
5374 => ping 192.168.0.1 # traffic sent on FEC
5375 => setenv ethact SCC
5376 => ping 10.0.0.1 # traffic sent on SCC
5378 ethrotate - When set to "no" U-Boot does not go through all
5379 available network interfaces.
5380 It just stays at the currently selected interface.
5382 netretry - When set to "no" each network operation will
5383 either succeed or fail without retrying.
5384 When set to "once" the network operation will
5385 fail when all the available network interfaces
5386 are tried once without success.
5387 Useful on scripts which control the retry operation
5390 npe_ucode - set load address for the NPE microcode
5392 silent_linux - If set then Linux will be told to boot silently, by
5393 changing the console to be empty. If "yes" it will be
5394 made silent. If "no" it will not be made silent. If
5395 unset, then it will be made silent if the U-Boot console
5398 tftpsrcp - If this is set, the value is used for TFTP's
5401 tftpdstp - If this is set, the value is used for TFTP's UDP
5402 destination port instead of the Well Know Port 69.
5404 tftpblocksize - Block size to use for TFTP transfers; if not set,
5405 we use the TFTP server's default block size
5407 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5408 seconds, minimum value is 1000 = 1 second). Defines
5409 when a packet is considered to be lost so it has to
5410 be retransmitted. The default is 5000 = 5 seconds.
5411 Lowering this value may make downloads succeed
5412 faster in networks with high packet loss rates or
5413 with unreliable TFTP servers.
5415 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5416 unit, minimum value = 0). Defines how many timeouts
5417 can happen during a single file transfer before that
5418 transfer is aborted. The default is 10, and 0 means
5419 'no timeouts allowed'. Increasing this value may help
5420 downloads succeed with high packet loss rates, or with
5421 unreliable TFTP servers or client hardware.
5423 vlan - When set to a value < 4095 the traffic over
5424 Ethernet is encapsulated/received over 802.1q
5427 The following image location variables contain the location of images
5428 used in booting. The "Image" column gives the role of the image and is
5429 not an environment variable name. The other columns are environment
5430 variable names. "File Name" gives the name of the file on a TFTP
5431 server, "RAM Address" gives the location in RAM the image will be
5432 loaded to, and "Flash Location" gives the image's address in NOR
5433 flash or offset in NAND flash.
5435 *Note* - these variables don't have to be defined for all boards, some
5436 boards currently use other variables for these purposes, and some
5437 boards use these variables for other purposes.
5439 Image File Name RAM Address Flash Location
5440 ----- --------- ----------- --------------
5441 u-boot u-boot u-boot_addr_r u-boot_addr
5442 Linux kernel bootfile kernel_addr_r kernel_addr
5443 device tree blob fdtfile fdt_addr_r fdt_addr
5444 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5446 The following environment variables may be used and automatically
5447 updated by the network boot commands ("bootp" and "rarpboot"),
5448 depending the information provided by your boot server:
5450 bootfile - see above
5451 dnsip - IP address of your Domain Name Server
5452 dnsip2 - IP address of your secondary Domain Name Server
5453 gatewayip - IP address of the Gateway (Router) to use
5454 hostname - Target hostname
5456 netmask - Subnet Mask
5457 rootpath - Pathname of the root filesystem on the NFS server
5458 serverip - see above
5461 There are two special Environment Variables:
5463 serial# - contains hardware identification information such
5464 as type string and/or serial number
5465 ethaddr - Ethernet address
5467 These variables can be set only once (usually during manufacturing of
5468 the board). U-Boot refuses to delete or overwrite these variables
5469 once they have been set once.
5472 Further special Environment Variables:
5474 ver - Contains the U-Boot version string as printed
5475 with the "version" command. This variable is
5476 readonly (see CONFIG_VERSION_VARIABLE).
5479 Please note that changes to some configuration parameters may take
5480 only effect after the next boot (yes, that's just like Windoze :-).
5483 Callback functions for environment variables:
5484 ---------------------------------------------
5486 For some environment variables, the behavior of u-boot needs to change
5487 when their values are changed. This functionality allows functions to
5488 be associated with arbitrary variables. On creation, overwrite, or
5489 deletion, the callback will provide the opportunity for some side
5490 effect to happen or for the change to be rejected.
5492 The callbacks are named and associated with a function using the
5493 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5495 These callbacks are associated with variables in one of two ways. The
5496 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5497 in the board configuration to a string that defines a list of
5498 associations. The list must be in the following format:
5500 entry = variable_name[:callback_name]
5503 If the callback name is not specified, then the callback is deleted.
5504 Spaces are also allowed anywhere in the list.
5506 Callbacks can also be associated by defining the ".callbacks" variable
5507 with the same list format above. Any association in ".callbacks" will
5508 override any association in the static list. You can define
5509 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5510 ".callbacks" environment variable in the default or embedded environment.
5512 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5513 regular expression. This allows multiple variables to be connected to
5514 the same callback without explicitly listing them all out.
5517 Command Line Parsing:
5518 =====================
5520 There are two different command line parsers available with U-Boot:
5521 the old "simple" one, and the much more powerful "hush" shell:
5523 Old, simple command line parser:
5524 --------------------------------
5526 - supports environment variables (through setenv / saveenv commands)
5527 - several commands on one line, separated by ';'
5528 - variable substitution using "... ${name} ..." syntax
5529 - special characters ('$', ';') can be escaped by prefixing with '\',
5531 setenv bootcmd bootm \${address}
5532 - You can also escape text by enclosing in single apostrophes, for example:
5533 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5538 - similar to Bourne shell, with control structures like
5539 if...then...else...fi, for...do...done; while...do...done,
5540 until...do...done, ...
5541 - supports environment ("global") variables (through setenv / saveenv
5542 commands) and local shell variables (through standard shell syntax
5543 "name=value"); only environment variables can be used with "run"
5549 (1) If a command line (or an environment variable executed by a "run"
5550 command) contains several commands separated by semicolon, and
5551 one of these commands fails, then the remaining commands will be
5554 (2) If you execute several variables with one call to run (i. e.
5555 calling run with a list of variables as arguments), any failing
5556 command will cause "run" to terminate, i. e. the remaining
5557 variables are not executed.
5559 Note for Redundant Ethernet Interfaces:
5560 =======================================
5562 Some boards come with redundant Ethernet interfaces; U-Boot supports
5563 such configurations and is capable of automatic selection of a
5564 "working" interface when needed. MAC assignment works as follows:
5566 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5567 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5568 "eth1addr" (=>eth1), "eth2addr", ...
5570 If the network interface stores some valid MAC address (for instance
5571 in SROM), this is used as default address if there is NO correspon-
5572 ding setting in the environment; if the corresponding environment
5573 variable is set, this overrides the settings in the card; that means:
5575 o If the SROM has a valid MAC address, and there is no address in the
5576 environment, the SROM's address is used.
5578 o If there is no valid address in the SROM, and a definition in the
5579 environment exists, then the value from the environment variable is
5582 o If both the SROM and the environment contain a MAC address, and
5583 both addresses are the same, this MAC address is used.
5585 o If both the SROM and the environment contain a MAC address, and the
5586 addresses differ, the value from the environment is used and a
5589 o If neither SROM nor the environment contain a MAC address, an error
5590 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5591 a random, locally-assigned MAC is used.
5593 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5594 will be programmed into hardware as part of the initialization process. This
5595 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5596 The naming convention is as follows:
5597 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5602 U-Boot is capable of booting (and performing other auxiliary operations on)
5603 images in two formats:
5605 New uImage format (FIT)
5606 -----------------------
5608 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5609 to Flattened Device Tree). It allows the use of images with multiple
5610 components (several kernels, ramdisks, etc.), with contents protected by
5611 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5617 Old image format is based on binary files which can be basically anything,
5618 preceded by a special header; see the definitions in include/image.h for
5619 details; basically, the header defines the following image properties:
5621 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5622 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5623 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5624 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5626 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5627 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5628 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5629 * Compression Type (uncompressed, gzip, bzip2)
5635 The header is marked by a special Magic Number, and both the header
5636 and the data portions of the image are secured against corruption by
5643 Although U-Boot should support any OS or standalone application
5644 easily, the main focus has always been on Linux during the design of
5647 U-Boot includes many features that so far have been part of some
5648 special "boot loader" code within the Linux kernel. Also, any
5649 "initrd" images to be used are no longer part of one big Linux image;
5650 instead, kernel and "initrd" are separate images. This implementation
5651 serves several purposes:
5653 - the same features can be used for other OS or standalone
5654 applications (for instance: using compressed images to reduce the
5655 Flash memory footprint)
5657 - it becomes much easier to port new Linux kernel versions because
5658 lots of low-level, hardware dependent stuff are done by U-Boot
5660 - the same Linux kernel image can now be used with different "initrd"
5661 images; of course this also means that different kernel images can
5662 be run with the same "initrd". This makes testing easier (you don't
5663 have to build a new "zImage.initrd" Linux image when you just
5664 change a file in your "initrd"). Also, a field-upgrade of the
5665 software is easier now.
5671 Porting Linux to U-Boot based systems:
5672 ---------------------------------------
5674 U-Boot cannot save you from doing all the necessary modifications to
5675 configure the Linux device drivers for use with your target hardware
5676 (no, we don't intend to provide a full virtual machine interface to
5679 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5681 Just make sure your machine specific header file (for instance
5682 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5683 Information structure as we define in include/asm-<arch>/u-boot.h,
5684 and make sure that your definition of IMAP_ADDR uses the same value
5685 as your U-Boot configuration in CONFIG_SYS_IMMR.
5687 Note that U-Boot now has a driver model, a unified model for drivers.
5688 If you are adding a new driver, plumb it into driver model. If there
5689 is no uclass available, you are encouraged to create one. See
5693 Configuring the Linux kernel:
5694 -----------------------------
5696 No specific requirements for U-Boot. Make sure you have some root
5697 device (initial ramdisk, NFS) for your target system.
5700 Building a Linux Image:
5701 -----------------------
5703 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5704 not used. If you use recent kernel source, a new build target
5705 "uImage" will exist which automatically builds an image usable by
5706 U-Boot. Most older kernels also have support for a "pImage" target,
5707 which was introduced for our predecessor project PPCBoot and uses a
5708 100% compatible format.
5712 make TQM850L_defconfig
5717 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5718 encapsulate a compressed Linux kernel image with header information,
5719 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5721 * build a standard "vmlinux" kernel image (in ELF binary format):
5723 * convert the kernel into a raw binary image:
5725 ${CROSS_COMPILE}-objcopy -O binary \
5726 -R .note -R .comment \
5727 -S vmlinux linux.bin
5729 * compress the binary image:
5733 * package compressed binary image for U-Boot:
5735 mkimage -A ppc -O linux -T kernel -C gzip \
5736 -a 0 -e 0 -n "Linux Kernel Image" \
5737 -d linux.bin.gz uImage
5740 The "mkimage" tool can also be used to create ramdisk images for use
5741 with U-Boot, either separated from the Linux kernel image, or
5742 combined into one file. "mkimage" encapsulates the images with a 64
5743 byte header containing information about target architecture,
5744 operating system, image type, compression method, entry points, time
5745 stamp, CRC32 checksums, etc.
5747 "mkimage" can be called in two ways: to verify existing images and
5748 print the header information, or to build new images.
5750 In the first form (with "-l" option) mkimage lists the information
5751 contained in the header of an existing U-Boot image; this includes
5752 checksum verification:
5754 tools/mkimage -l image
5755 -l ==> list image header information
5757 The second form (with "-d" option) is used to build a U-Boot image
5758 from a "data file" which is used as image payload:
5760 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5761 -n name -d data_file image
5762 -A ==> set architecture to 'arch'
5763 -O ==> set operating system to 'os'
5764 -T ==> set image type to 'type'
5765 -C ==> set compression type 'comp'
5766 -a ==> set load address to 'addr' (hex)
5767 -e ==> set entry point to 'ep' (hex)
5768 -n ==> set image name to 'name'
5769 -d ==> use image data from 'datafile'
5771 Right now, all Linux kernels for PowerPC systems use the same load
5772 address (0x00000000), but the entry point address depends on the
5775 - 2.2.x kernels have the entry point at 0x0000000C,
5776 - 2.3.x and later kernels have the entry point at 0x00000000.
5778 So a typical call to build a U-Boot image would read:
5780 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5781 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5782 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5783 > examples/uImage.TQM850L
5784 Image Name: 2.4.4 kernel for TQM850L
5785 Created: Wed Jul 19 02:34:59 2000
5786 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5787 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5788 Load Address: 0x00000000
5789 Entry Point: 0x00000000
5791 To verify the contents of the image (or check for corruption):
5793 -> tools/mkimage -l examples/uImage.TQM850L
5794 Image Name: 2.4.4 kernel for TQM850L
5795 Created: Wed Jul 19 02:34:59 2000
5796 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5797 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5798 Load Address: 0x00000000
5799 Entry Point: 0x00000000
5801 NOTE: for embedded systems where boot time is critical you can trade
5802 speed for memory and install an UNCOMPRESSED image instead: this
5803 needs more space in Flash, but boots much faster since it does not
5804 need to be uncompressed:
5806 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5807 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5808 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5809 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5810 > examples/uImage.TQM850L-uncompressed
5811 Image Name: 2.4.4 kernel for TQM850L
5812 Created: Wed Jul 19 02:34:59 2000
5813 Image Type: PowerPC Linux Kernel Image (uncompressed)
5814 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5815 Load Address: 0x00000000
5816 Entry Point: 0x00000000
5819 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5820 when your kernel is intended to use an initial ramdisk:
5822 -> tools/mkimage -n 'Simple Ramdisk Image' \
5823 > -A ppc -O linux -T ramdisk -C gzip \
5824 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5825 Image Name: Simple Ramdisk Image
5826 Created: Wed Jan 12 14:01:50 2000
5827 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5828 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5829 Load Address: 0x00000000
5830 Entry Point: 0x00000000
5832 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5833 option performs the converse operation of the mkimage's second form (the "-d"
5834 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5837 tools/dumpimage -i image -T type -p position data_file
5838 -i ==> extract from the 'image' a specific 'data_file'
5839 -T ==> set image type to 'type'
5840 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5843 Installing a Linux Image:
5844 -------------------------
5846 To downloading a U-Boot image over the serial (console) interface,
5847 you must convert the image to S-Record format:
5849 objcopy -I binary -O srec examples/image examples/image.srec
5851 The 'objcopy' does not understand the information in the U-Boot
5852 image header, so the resulting S-Record file will be relative to
5853 address 0x00000000. To load it to a given address, you need to
5854 specify the target address as 'offset' parameter with the 'loads'
5857 Example: install the image to address 0x40100000 (which on the
5858 TQM8xxL is in the first Flash bank):
5860 => erase 40100000 401FFFFF
5866 ## Ready for S-Record download ...
5867 ~>examples/image.srec
5868 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5870 15989 15990 15991 15992
5871 [file transfer complete]
5873 ## Start Addr = 0x00000000
5876 You can check the success of the download using the 'iminfo' command;
5877 this includes a checksum verification so you can be sure no data
5878 corruption happened:
5882 ## Checking Image at 40100000 ...
5883 Image Name: 2.2.13 for initrd on TQM850L
5884 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5885 Data Size: 335725 Bytes = 327 kB = 0 MB
5886 Load Address: 00000000
5887 Entry Point: 0000000c
5888 Verifying Checksum ... OK
5894 The "bootm" command is used to boot an application that is stored in
5895 memory (RAM or Flash). In case of a Linux kernel image, the contents
5896 of the "bootargs" environment variable is passed to the kernel as
5897 parameters. You can check and modify this variable using the
5898 "printenv" and "setenv" commands:
5901 => printenv bootargs
5902 bootargs=root=/dev/ram
5904 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5906 => printenv bootargs
5907 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5910 ## Booting Linux kernel at 40020000 ...
5911 Image Name: 2.2.13 for NFS on TQM850L
5912 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5913 Data Size: 381681 Bytes = 372 kB = 0 MB
5914 Load Address: 00000000
5915 Entry Point: 0000000c
5916 Verifying Checksum ... OK
5917 Uncompressing Kernel Image ... OK
5918 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
5919 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5920 time_init: decrementer frequency = 187500000/60
5921 Calibrating delay loop... 49.77 BogoMIPS
5922 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5925 If you want to boot a Linux kernel with initial RAM disk, you pass
5926 the memory addresses of both the kernel and the initrd image (PPBCOOT
5927 format!) to the "bootm" command:
5929 => imi 40100000 40200000
5931 ## Checking Image at 40100000 ...
5932 Image Name: 2.2.13 for initrd on TQM850L
5933 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5934 Data Size: 335725 Bytes = 327 kB = 0 MB
5935 Load Address: 00000000
5936 Entry Point: 0000000c
5937 Verifying Checksum ... OK
5939 ## Checking Image at 40200000 ...
5940 Image Name: Simple Ramdisk Image
5941 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5942 Data Size: 566530 Bytes = 553 kB = 0 MB
5943 Load Address: 00000000
5944 Entry Point: 00000000
5945 Verifying Checksum ... OK
5947 => bootm 40100000 40200000
5948 ## Booting Linux kernel at 40100000 ...
5949 Image Name: 2.2.13 for initrd on TQM850L
5950 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5951 Data Size: 335725 Bytes = 327 kB = 0 MB
5952 Load Address: 00000000
5953 Entry Point: 0000000c
5954 Verifying Checksum ... OK
5955 Uncompressing Kernel Image ... OK
5956 ## Loading RAMDisk Image at 40200000 ...
5957 Image Name: Simple Ramdisk Image
5958 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5959 Data Size: 566530 Bytes = 553 kB = 0 MB
5960 Load Address: 00000000
5961 Entry Point: 00000000
5962 Verifying Checksum ... OK
5963 Loading Ramdisk ... OK
5964 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
5965 Boot arguments: root=/dev/ram
5966 time_init: decrementer frequency = 187500000/60
5967 Calibrating delay loop... 49.77 BogoMIPS
5969 RAMDISK: Compressed image found at block 0
5970 VFS: Mounted root (ext2 filesystem).
5974 Boot Linux and pass a flat device tree:
5977 First, U-Boot must be compiled with the appropriate defines. See the section
5978 titled "Linux Kernel Interface" above for a more in depth explanation. The
5979 following is an example of how to start a kernel and pass an updated
5985 oft=oftrees/mpc8540ads.dtb
5986 => tftp $oftaddr $oft
5987 Speed: 1000, full duplex
5989 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5990 Filename 'oftrees/mpc8540ads.dtb'.
5991 Load address: 0x300000
5994 Bytes transferred = 4106 (100a hex)
5995 => tftp $loadaddr $bootfile
5996 Speed: 1000, full duplex
5998 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6000 Load address: 0x200000
6001 Loading:############
6003 Bytes transferred = 1029407 (fb51f hex)
6008 => bootm $loadaddr - $oftaddr
6009 ## Booting image at 00200000 ...
6010 Image Name: Linux-2.6.17-dirty
6011 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6012 Data Size: 1029343 Bytes = 1005.2 kB
6013 Load Address: 00000000
6014 Entry Point: 00000000
6015 Verifying Checksum ... OK
6016 Uncompressing Kernel Image ... OK
6017 Booting using flat device tree at 0x300000
6018 Using MPC85xx ADS machine description
6019 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6023 More About U-Boot Image Types:
6024 ------------------------------
6026 U-Boot supports the following image types:
6028 "Standalone Programs" are directly runnable in the environment
6029 provided by U-Boot; it is expected that (if they behave
6030 well) you can continue to work in U-Boot after return from
6031 the Standalone Program.
6032 "OS Kernel Images" are usually images of some Embedded OS which
6033 will take over control completely. Usually these programs
6034 will install their own set of exception handlers, device
6035 drivers, set up the MMU, etc. - this means, that you cannot
6036 expect to re-enter U-Boot except by resetting the CPU.
6037 "RAMDisk Images" are more or less just data blocks, and their
6038 parameters (address, size) are passed to an OS kernel that is
6040 "Multi-File Images" contain several images, typically an OS
6041 (Linux) kernel image and one or more data images like
6042 RAMDisks. This construct is useful for instance when you want
6043 to boot over the network using BOOTP etc., where the boot
6044 server provides just a single image file, but you want to get
6045 for instance an OS kernel and a RAMDisk image.
6047 "Multi-File Images" start with a list of image sizes, each
6048 image size (in bytes) specified by an "uint32_t" in network
6049 byte order. This list is terminated by an "(uint32_t)0".
6050 Immediately after the terminating 0 follow the images, one by
6051 one, all aligned on "uint32_t" boundaries (size rounded up to
6052 a multiple of 4 bytes).
6054 "Firmware Images" are binary images containing firmware (like
6055 U-Boot or FPGA images) which usually will be programmed to
6058 "Script files" are command sequences that will be executed by
6059 U-Boot's command interpreter; this feature is especially
6060 useful when you configure U-Boot to use a real shell (hush)
6061 as command interpreter.
6063 Booting the Linux zImage:
6064 -------------------------
6066 On some platforms, it's possible to boot Linux zImage. This is done
6067 using the "bootz" command. The syntax of "bootz" command is the same
6068 as the syntax of "bootm" command.
6070 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6071 kernel with raw initrd images. The syntax is slightly different, the
6072 address of the initrd must be augmented by it's size, in the following
6073 format: "<initrd addres>:<initrd size>".
6079 One of the features of U-Boot is that you can dynamically load and
6080 run "standalone" applications, which can use some resources of
6081 U-Boot like console I/O functions or interrupt services.
6083 Two simple examples are included with the sources:
6088 'examples/hello_world.c' contains a small "Hello World" Demo
6089 application; it is automatically compiled when you build U-Boot.
6090 It's configured to run at address 0x00040004, so you can play with it
6094 ## Ready for S-Record download ...
6095 ~>examples/hello_world.srec
6096 1 2 3 4 5 6 7 8 9 10 11 ...
6097 [file transfer complete]
6099 ## Start Addr = 0x00040004
6101 => go 40004 Hello World! This is a test.
6102 ## Starting application at 0x00040004 ...
6113 Hit any key to exit ...
6115 ## Application terminated, rc = 0x0
6117 Another example, which demonstrates how to register a CPM interrupt
6118 handler with the U-Boot code, can be found in 'examples/timer.c'.
6119 Here, a CPM timer is set up to generate an interrupt every second.
6120 The interrupt service routine is trivial, just printing a '.'
6121 character, but this is just a demo program. The application can be
6122 controlled by the following keys:
6124 ? - print current values og the CPM Timer registers
6125 b - enable interrupts and start timer
6126 e - stop timer and disable interrupts
6127 q - quit application
6130 ## Ready for S-Record download ...
6131 ~>examples/timer.srec
6132 1 2 3 4 5 6 7 8 9 10 11 ...
6133 [file transfer complete]
6135 ## Start Addr = 0x00040004
6138 ## Starting application at 0x00040004 ...
6141 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6144 [q, b, e, ?] Set interval 1000000 us
6147 [q, b, e, ?] ........
6148 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6151 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6154 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6157 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6159 [q, b, e, ?] ...Stopping timer
6161 [q, b, e, ?] ## Application terminated, rc = 0x0
6167 Over time, many people have reported problems when trying to use the
6168 "minicom" terminal emulation program for serial download. I (wd)
6169 consider minicom to be broken, and recommend not to use it. Under
6170 Unix, I recommend to use C-Kermit for general purpose use (and
6171 especially for kermit binary protocol download ("loadb" command), and
6172 use "cu" for S-Record download ("loads" command). See
6173 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6174 for help with kermit.
6177 Nevertheless, if you absolutely want to use it try adding this
6178 configuration to your "File transfer protocols" section:
6180 Name Program Name U/D FullScr IO-Red. Multi
6181 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6182 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6188 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6189 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6191 Building requires a cross environment; it is known to work on
6192 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6193 need gmake since the Makefiles are not compatible with BSD make).
6194 Note that the cross-powerpc package does not install include files;
6195 attempting to build U-Boot will fail because <machine/ansi.h> is
6196 missing. This file has to be installed and patched manually:
6198 # cd /usr/pkg/cross/powerpc-netbsd/include
6200 # ln -s powerpc machine
6201 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6202 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6204 Native builds *don't* work due to incompatibilities between native
6205 and U-Boot include files.
6207 Booting assumes that (the first part of) the image booted is a
6208 stage-2 loader which in turn loads and then invokes the kernel
6209 proper. Loader sources will eventually appear in the NetBSD source
6210 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6211 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6214 Implementation Internals:
6215 =========================
6217 The following is not intended to be a complete description of every
6218 implementation detail. However, it should help to understand the
6219 inner workings of U-Boot and make it easier to port it to custom
6223 Initial Stack, Global Data:
6224 ---------------------------
6226 The implementation of U-Boot is complicated by the fact that U-Boot
6227 starts running out of ROM (flash memory), usually without access to
6228 system RAM (because the memory controller is not initialized yet).
6229 This means that we don't have writable Data or BSS segments, and BSS
6230 is not initialized as zero. To be able to get a C environment working
6231 at all, we have to allocate at least a minimal stack. Implementation
6232 options for this are defined and restricted by the CPU used: Some CPU
6233 models provide on-chip memory (like the IMMR area on MPC8xx and
6234 MPC826x processors), on others (parts of) the data cache can be
6235 locked as (mis-) used as memory, etc.
6237 Chris Hallinan posted a good summary of these issues to the
6238 U-Boot mailing list:
6240 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6241 From: "Chris Hallinan" <clh@net1plus.com>
6242 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6245 Correct me if I'm wrong, folks, but the way I understand it
6246 is this: Using DCACHE as initial RAM for Stack, etc, does not
6247 require any physical RAM backing up the cache. The cleverness
6248 is that the cache is being used as a temporary supply of
6249 necessary storage before the SDRAM controller is setup. It's
6250 beyond the scope of this list to explain the details, but you
6251 can see how this works by studying the cache architecture and
6252 operation in the architecture and processor-specific manuals.
6254 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6255 is another option for the system designer to use as an
6256 initial stack/RAM area prior to SDRAM being available. Either
6257 option should work for you. Using CS 4 should be fine if your
6258 board designers haven't used it for something that would
6259 cause you grief during the initial boot! It is frequently not
6262 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6263 with your processor/board/system design. The default value
6264 you will find in any recent u-boot distribution in
6265 walnut.h should work for you. I'd set it to a value larger
6266 than your SDRAM module. If you have a 64MB SDRAM module, set
6267 it above 400_0000. Just make sure your board has no resources
6268 that are supposed to respond to that address! That code in
6269 start.S has been around a while and should work as is when
6270 you get the config right.
6275 It is essential to remember this, since it has some impact on the C
6276 code for the initialization procedures:
6278 * Initialized global data (data segment) is read-only. Do not attempt
6281 * Do not use any uninitialized global data (or implicitly initialized
6282 as zero data - BSS segment) at all - this is undefined, initiali-
6283 zation is performed later (when relocating to RAM).
6285 * Stack space is very limited. Avoid big data buffers or things like
6288 Having only the stack as writable memory limits means we cannot use
6289 normal global data to share information between the code. But it
6290 turned out that the implementation of U-Boot can be greatly
6291 simplified by making a global data structure (gd_t) available to all
6292 functions. We could pass a pointer to this data as argument to _all_
6293 functions, but this would bloat the code. Instead we use a feature of
6294 the GCC compiler (Global Register Variables) to share the data: we
6295 place a pointer (gd) to the global data into a register which we
6296 reserve for this purpose.
6298 When choosing a register for such a purpose we are restricted by the
6299 relevant (E)ABI specifications for the current architecture, and by
6300 GCC's implementation.
6302 For PowerPC, the following registers have specific use:
6304 R2: reserved for system use
6305 R3-R4: parameter passing and return values
6306 R5-R10: parameter passing
6307 R13: small data area pointer
6311 (U-Boot also uses R12 as internal GOT pointer. r12
6312 is a volatile register so r12 needs to be reset when
6313 going back and forth between asm and C)
6315 ==> U-Boot will use R2 to hold a pointer to the global data
6317 Note: on PPC, we could use a static initializer (since the
6318 address of the global data structure is known at compile time),
6319 but it turned out that reserving a register results in somewhat
6320 smaller code - although the code savings are not that big (on
6321 average for all boards 752 bytes for the whole U-Boot image,
6322 624 text + 127 data).
6324 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6325 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6327 ==> U-Boot will use P3 to hold a pointer to the global data
6329 On ARM, the following registers are used:
6331 R0: function argument word/integer result
6332 R1-R3: function argument word
6333 R9: platform specific
6334 R10: stack limit (used only if stack checking is enabled)
6335 R11: argument (frame) pointer
6336 R12: temporary workspace
6339 R15: program counter
6341 ==> U-Boot will use R9 to hold a pointer to the global data
6343 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6345 On Nios II, the ABI is documented here:
6346 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6348 ==> U-Boot will use gp to hold a pointer to the global data
6350 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6351 to access small data sections, so gp is free.
6353 On NDS32, the following registers are used:
6355 R0-R1: argument/return
6357 R15: temporary register for assembler
6358 R16: trampoline register
6359 R28: frame pointer (FP)
6360 R29: global pointer (GP)
6361 R30: link register (LP)
6362 R31: stack pointer (SP)
6363 PC: program counter (PC)
6365 ==> U-Boot will use R10 to hold a pointer to the global data
6367 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6368 or current versions of GCC may "optimize" the code too much.
6373 U-Boot runs in system state and uses physical addresses, i.e. the
6374 MMU is not used either for address mapping nor for memory protection.
6376 The available memory is mapped to fixed addresses using the memory
6377 controller. In this process, a contiguous block is formed for each
6378 memory type (Flash, SDRAM, SRAM), even when it consists of several
6379 physical memory banks.
6381 U-Boot is installed in the first 128 kB of the first Flash bank (on
6382 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6383 booting and sizing and initializing DRAM, the code relocates itself
6384 to the upper end of DRAM. Immediately below the U-Boot code some
6385 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6386 configuration setting]. Below that, a structure with global Board
6387 Info data is placed, followed by the stack (growing downward).
6389 Additionally, some exception handler code is copied to the low 8 kB
6390 of DRAM (0x00000000 ... 0x00001FFF).
6392 So a typical memory configuration with 16 MB of DRAM could look like
6395 0x0000 0000 Exception Vector code
6398 0x0000 2000 Free for Application Use
6404 0x00FB FF20 Monitor Stack (Growing downward)
6405 0x00FB FFAC Board Info Data and permanent copy of global data
6406 0x00FC 0000 Malloc Arena
6409 0x00FE 0000 RAM Copy of Monitor Code
6410 ... eventually: LCD or video framebuffer
6411 ... eventually: pRAM (Protected RAM - unchanged by reset)
6412 0x00FF FFFF [End of RAM]
6415 System Initialization:
6416 ----------------------
6418 In the reset configuration, U-Boot starts at the reset entry point
6419 (on most PowerPC systems at address 0x00000100). Because of the reset
6420 configuration for CS0# this is a mirror of the on board Flash memory.
6421 To be able to re-map memory U-Boot then jumps to its link address.
6422 To be able to implement the initialization code in C, a (small!)
6423 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6424 which provide such a feature like MPC8xx or MPC8260), or in a locked
6425 part of the data cache. After that, U-Boot initializes the CPU core,
6426 the caches and the SIU.
6428 Next, all (potentially) available memory banks are mapped using a
6429 preliminary mapping. For example, we put them on 512 MB boundaries
6430 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6431 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6432 programmed for SDRAM access. Using the temporary configuration, a
6433 simple memory test is run that determines the size of the SDRAM
6436 When there is more than one SDRAM bank, and the banks are of
6437 different size, the largest is mapped first. For equal size, the first
6438 bank (CS2#) is mapped first. The first mapping is always for address
6439 0x00000000, with any additional banks following immediately to create
6440 contiguous memory starting from 0.
6442 Then, the monitor installs itself at the upper end of the SDRAM area
6443 and allocates memory for use by malloc() and for the global Board
6444 Info data; also, the exception vector code is copied to the low RAM
6445 pages, and the final stack is set up.
6447 Only after this relocation will you have a "normal" C environment;
6448 until that you are restricted in several ways, mostly because you are
6449 running from ROM, and because the code will have to be relocated to a
6453 U-Boot Porting Guide:
6454 ----------------------
6456 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6460 int main(int argc, char *argv[])
6462 sighandler_t no_more_time;
6464 signal(SIGALRM, no_more_time);
6465 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6467 if (available_money > available_manpower) {
6468 Pay consultant to port U-Boot;
6472 Download latest U-Boot source;
6474 Subscribe to u-boot mailing list;
6477 email("Hi, I am new to U-Boot, how do I get started?");
6480 Read the README file in the top level directory;
6481 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6482 Read applicable doc/*.README;
6483 Read the source, Luke;
6484 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6487 if (available_money > toLocalCurrency ($2500))
6490 Add a lot of aggravation and time;
6492 if (a similar board exists) { /* hopefully... */
6493 cp -a board/<similar> board/<myboard>
6494 cp include/configs/<similar>.h include/configs/<myboard>.h
6496 Create your own board support subdirectory;
6497 Create your own board include/configs/<myboard>.h file;
6499 Edit new board/<myboard> files
6500 Edit new include/configs/<myboard>.h
6505 Add / modify source code;
6509 email("Hi, I am having problems...");
6511 Send patch file to the U-Boot email list;
6512 if (reasonable critiques)
6513 Incorporate improvements from email list code review;
6515 Defend code as written;
6521 void no_more_time (int sig)
6530 All contributions to U-Boot should conform to the Linux kernel
6531 coding style; see the file "Documentation/CodingStyle" and the script
6532 "scripts/Lindent" in your Linux kernel source directory.
6534 Source files originating from a different project (for example the
6535 MTD subsystem) are generally exempt from these guidelines and are not
6536 reformatted to ease subsequent migration to newer versions of those
6539 Please note that U-Boot is implemented in C (and to some small parts in
6540 Assembler); no C++ is used, so please do not use C++ style comments (//)
6543 Please also stick to the following formatting rules:
6544 - remove any trailing white space
6545 - use TAB characters for indentation and vertical alignment, not spaces
6546 - make sure NOT to use DOS '\r\n' line feeds
6547 - do not add more than 2 consecutive empty lines to source files
6548 - do not add trailing empty lines to source files
6550 Submissions which do not conform to the standards may be returned
6551 with a request to reformat the changes.
6557 Since the number of patches for U-Boot is growing, we need to
6558 establish some rules. Submissions which do not conform to these rules
6559 may be rejected, even when they contain important and valuable stuff.
6561 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6563 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6564 see http://lists.denx.de/mailman/listinfo/u-boot
6566 When you send a patch, please include the following information with
6569 * For bug fixes: a description of the bug and how your patch fixes
6570 this bug. Please try to include a way of demonstrating that the
6571 patch actually fixes something.
6573 * For new features: a description of the feature and your
6576 * A CHANGELOG entry as plaintext (separate from the patch)
6578 * For major contributions, add a MAINTAINERS file with your
6579 information and associated file and directory references.
6581 * When you add support for a new board, don't forget to add a
6582 maintainer e-mail address to the boards.cfg file, too.
6584 * If your patch adds new configuration options, don't forget to
6585 document these in the README file.
6587 * The patch itself. If you are using git (which is *strongly*
6588 recommended) you can easily generate the patch using the
6589 "git format-patch". If you then use "git send-email" to send it to
6590 the U-Boot mailing list, you will avoid most of the common problems
6591 with some other mail clients.
6593 If you cannot use git, use "diff -purN OLD NEW". If your version of
6594 diff does not support these options, then get the latest version of
6597 The current directory when running this command shall be the parent
6598 directory of the U-Boot source tree (i. e. please make sure that
6599 your patch includes sufficient directory information for the
6602 We prefer patches as plain text. MIME attachments are discouraged,
6603 and compressed attachments must not be used.
6605 * If one logical set of modifications affects or creates several
6606 files, all these changes shall be submitted in a SINGLE patch file.
6608 * Changesets that contain different, unrelated modifications shall be
6609 submitted as SEPARATE patches, one patch per changeset.
6614 * Before sending the patch, run the MAKEALL script on your patched
6615 source tree and make sure that no errors or warnings are reported
6616 for any of the boards.
6618 * Keep your modifications to the necessary minimum: A patch
6619 containing several unrelated changes or arbitrary reformats will be
6620 returned with a request to re-formatting / split it.
6622 * If you modify existing code, make sure that your new code does not
6623 add to the memory footprint of the code ;-) Small is beautiful!
6624 When adding new features, these should compile conditionally only
6625 (using #ifdef), and the resulting code with the new feature
6626 disabled must not need more memory than the old code without your
6629 * Remember that there is a size limit of 100 kB per message on the
6630 u-boot mailing list. Bigger patches will be moderated. If they are
6631 reasonable and not too big, they will be acknowledged. But patches
6632 bigger than the size limit should be avoided.
projects / u-boot / blob