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 candidate 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 /m68k Files generic to m68k architecture
141 /microblaze Files generic to microblaze architecture
142 /mips Files generic to MIPS architecture
143 /nds32 Files generic to NDS32 architecture
144 /nios2 Files generic to Altera NIOS2 architecture
145 /openrisc Files generic to OpenRISC architecture
146 /powerpc Files generic to PowerPC architecture
147 /sandbox Files generic to HW-independent "sandbox"
148 /sh Files generic to SH architecture
149 /x86 Files generic to x86 architecture
150 /api Machine/arch independent API for external apps
151 /board Board dependent files
152 /cmd U-Boot commands functions
153 /common Misc architecture independent functions
154 /configs Board default configuration files
155 /disk Code for disk drive partition handling
156 /doc Documentation (don't expect too much)
157 /drivers Commonly used device drivers
158 /dts Contains Makefile for building internal U-Boot fdt.
159 /examples Example code for standalone applications, etc.
160 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
161 /include Header Files
162 /lib Library routines generic to all architectures
163 /Licenses Various license files
165 /post Power On Self Test
166 /scripts Various build scripts and Makefiles
167 /test Various unit test files
168 /tools Tools to build S-Record or U-Boot images, etc.
170 Software Configuration:
171 =======================
173 Configuration is usually done using C preprocessor defines; the
174 rationale behind that is to avoid dead code whenever possible.
176 There are two classes of configuration variables:
178 * Configuration _OPTIONS_:
179 These are selectable by the user and have names beginning with
182 * Configuration _SETTINGS_:
183 These depend on the hardware etc. and should not be meddled with if
184 you don't know what you're doing; they have names beginning with
187 Previously, all configuration was done by hand, which involved creating
188 symbolic links and editing configuration files manually. More recently,
189 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
190 allowing you to use the "make menuconfig" command to configure your
194 Selection of Processor Architecture and Board Type:
195 ---------------------------------------------------
197 For all supported boards there are ready-to-use default
198 configurations available; just type "make <board_name>_defconfig".
200 Example: For a TQM823L module type:
203 make TQM823L_defconfig
205 Note: If you're looking for the default configuration file for a board
206 you're sure used to be there but is now missing, check the file
207 doc/README.scrapyard for a list of no longer supported boards.
212 U-Boot can be built natively to run on a Linux host using the 'sandbox'
213 board. This allows feature development which is not board- or architecture-
214 specific to be undertaken on a native platform. The sandbox is also used to
215 run some of U-Boot's tests.
217 See board/sandbox/README.sandbox for more details.
220 Board Initialisation Flow:
221 --------------------------
223 This is the intended start-up flow for boards. This should apply for both
224 SPL and U-Boot proper (i.e. they both follow the same rules).
226 Note: "SPL" stands for "Secondary Program Loader," which is explained in
227 more detail later in this file.
229 At present, SPL mostly uses a separate code path, but the function names
230 and roles of each function are the same. Some boards or architectures
231 may not conform to this. At least most ARM boards which use
232 CONFIG_SPL_FRAMEWORK conform to this.
234 Execution typically starts with an architecture-specific (and possibly
235 CPU-specific) start.S file, such as:
237 - arch/arm/cpu/armv7/start.S
238 - arch/powerpc/cpu/mpc83xx/start.S
239 - arch/mips/cpu/start.S
241 and so on. From there, three functions are called; the purpose and
242 limitations of each of these functions are described below.
245 - purpose: essential init to permit execution to reach board_init_f()
246 - no global_data or BSS
247 - there is no stack (ARMv7 may have one but it will soon be removed)
248 - must not set up SDRAM or use console
249 - must only do the bare minimum to allow execution to continue to
251 - this is almost never needed
252 - return normally from this function
255 - purpose: set up the machine ready for running board_init_r():
256 i.e. SDRAM and serial UART
257 - global_data is available
259 - BSS is not available, so you cannot use global/static variables,
260 only stack variables and global_data
262 Non-SPL-specific notes:
263 - dram_init() is called to set up DRAM. If already done in SPL this
267 - you can override the entire board_init_f() function with your own
269 - preloader_console_init() can be called here in extremis
270 - should set up SDRAM, and anything needed to make the UART work
271 - these is no need to clear BSS, it will be done by crt0.S
272 - must return normally from this function (don't call board_init_r()
275 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
276 this point the stack and global_data are relocated to below
277 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
281 - purpose: main execution, common code
282 - global_data is available
284 - BSS is available, all static/global variables can be used
285 - execution eventually continues to main_loop()
287 Non-SPL-specific notes:
288 - U-Boot is relocated to the top of memory and is now running from
292 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
293 CONFIG_SPL_STACK_R_ADDR points into SDRAM
294 - preloader_console_init() can be called here - typically this is
295 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
296 spl_board_init() function containing this call
297 - loads U-Boot or (in falcon mode) Linux
301 Configuration Options:
302 ----------------------
304 Configuration depends on the combination of board and CPU type; all
305 such information is kept in a configuration file
306 "include/configs/<board_name>.h".
308 Example: For a TQM823L module, all configuration settings are in
309 "include/configs/TQM823L.h".
312 Many of the options are named exactly as the corresponding Linux
313 kernel configuration options. The intention is to make it easier to
314 build a config tool - later.
317 The following options need to be configured:
319 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
321 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
323 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
324 Define exactly one, e.g. CONFIG_ATSTK1002
326 - Marvell Family Member
327 CONFIG_SYS_MVFS - define it if you want to enable
328 multiple fs option at one time
329 for marvell soc family
334 Specifies that the core is a 64-bit PowerPC implementation (implements
335 the "64" category of the Power ISA). This is necessary for ePAPR
336 compliance, among other possible reasons.
338 CONFIG_SYS_FSL_TBCLK_DIV
340 Defines the core time base clock divider ratio compared to the
341 system clock. On most PQ3 devices this is 8, on newer QorIQ
342 devices it can be 16 or 32. The ratio varies from SoC to Soc.
344 CONFIG_SYS_FSL_PCIE_COMPAT
346 Defines the string to utilize when trying to match PCIe device
347 tree nodes for the given platform.
349 CONFIG_SYS_FSL_ERRATUM_A004510
351 Enables a workaround for erratum A004510. If set,
352 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
353 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
355 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
356 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
358 Defines one or two SoC revisions (low 8 bits of SVR)
359 for which the A004510 workaround should be applied.
361 The rest of SVR is either not relevant to the decision
362 of whether the erratum is present (e.g. p2040 versus
363 p2041) or is implied by the build target, which controls
364 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
366 See Freescale App Note 4493 for more information about
369 CONFIG_A003399_NOR_WORKAROUND
370 Enables a workaround for IFC erratum A003399. It is only
371 required during NOR boot.
373 CONFIG_A008044_WORKAROUND
374 Enables a workaround for T1040/T1042 erratum A008044. It is only
375 required during NAND boot and valid for Rev 1.0 SoC revision
377 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
379 This is the value to write into CCSR offset 0x18600
380 according to the A004510 workaround.
382 CONFIG_SYS_FSL_DSP_DDR_ADDR
383 This value denotes start offset of DDR memory which is
384 connected exclusively to the DSP cores.
386 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
387 This value denotes start offset of M2 memory
388 which is directly connected to the DSP core.
390 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
391 This value denotes start offset of M3 memory which is directly
392 connected to the DSP core.
394 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
395 This value denotes start offset of DSP CCSR space.
397 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
398 Single Source Clock is clocking mode present in some of FSL SoC's.
399 In this mode, a single differential clock is used to supply
400 clocks to the sysclock, ddrclock and usbclock.
402 CONFIG_SYS_CPC_REINIT_F
403 This CONFIG is defined when the CPC is configured as SRAM at the
404 time of U-Boot entry and is required to be re-initialized.
407 Indicates this SoC supports deep sleep feature. If deep sleep is
408 supported, core will start to execute uboot when wakes up.
410 - Generic CPU options:
411 CONFIG_SYS_GENERIC_GLOBAL_DATA
412 Defines global data is initialized in generic board board_init_f().
413 If this macro is defined, global data is created and cleared in
414 generic board board_init_f(). Without this macro, architecture/board
415 should initialize global data before calling board_init_f().
417 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
419 Defines the endianess of the CPU. Implementation of those
420 values is arch specific.
423 Freescale DDR driver in use. This type of DDR controller is
424 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
427 CONFIG_SYS_FSL_DDR_ADDR
428 Freescale DDR memory-mapped register base.
430 CONFIG_SYS_FSL_DDR_EMU
431 Specify emulator support for DDR. Some DDR features such as
432 deskew training are not available.
434 CONFIG_SYS_FSL_DDRC_GEN1
435 Freescale DDR1 controller.
437 CONFIG_SYS_FSL_DDRC_GEN2
438 Freescale DDR2 controller.
440 CONFIG_SYS_FSL_DDRC_GEN3
441 Freescale DDR3 controller.
443 CONFIG_SYS_FSL_DDRC_GEN4
444 Freescale DDR4 controller.
446 CONFIG_SYS_FSL_DDRC_ARM_GEN3
447 Freescale DDR3 controller for ARM-based SoCs.
450 Board config to use DDR1. It can be enabled for SoCs with
451 Freescale DDR1 or DDR2 controllers, depending on the board
455 Board config to use DDR2. It can be enabled for SoCs with
456 Freescale DDR2 or DDR3 controllers, depending on the board
460 Board config to use DDR3. It can be enabled for SoCs with
461 Freescale DDR3 or DDR3L controllers.
464 Board config to use DDR3L. It can be enabled for SoCs with
468 Board config to use DDR4. It can be enabled for SoCs with
471 CONFIG_SYS_FSL_IFC_BE
472 Defines the IFC controller register space as Big Endian
474 CONFIG_SYS_FSL_IFC_LE
475 Defines the IFC controller register space as Little Endian
477 CONFIG_SYS_FSL_IFC_CLK_DIV
478 Defines divider of platform clock(clock input to IFC controller).
480 CONFIG_SYS_FSL_LBC_CLK_DIV
481 Defines divider of platform clock(clock input to eLBC controller).
483 CONFIG_SYS_FSL_PBL_PBI
484 It enables addition of RCW (Power on reset configuration) in built image.
485 Please refer doc/README.pblimage for more details
487 CONFIG_SYS_FSL_PBL_RCW
488 It adds PBI(pre-boot instructions) commands in u-boot build image.
489 PBI commands can be used to configure SoC before it starts the execution.
490 Please refer doc/README.pblimage for more details
493 It adds a target to create boot binary having SPL binary in PBI format
494 concatenated with u-boot binary.
496 CONFIG_SYS_FSL_DDR_BE
497 Defines the DDR controller register space as Big Endian
499 CONFIG_SYS_FSL_DDR_LE
500 Defines the DDR controller register space as Little Endian
502 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
503 Physical address from the view of DDR controllers. It is the
504 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
505 it could be different for ARM SoCs.
507 CONFIG_SYS_FSL_DDR_INTLV_256B
508 DDR controller interleaving on 256-byte. This is a special
509 interleaving mode, handled by Dickens for Freescale layerscape
512 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
513 Number of controllers used as main memory.
515 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
516 Number of controllers used for other than main memory.
518 CONFIG_SYS_FSL_HAS_DP_DDR
519 Defines the SoC has DP-DDR used for DPAA.
521 CONFIG_SYS_FSL_SEC_BE
522 Defines the SEC controller register space as Big Endian
524 CONFIG_SYS_FSL_SEC_LE
525 Defines the SEC controller register space as Little Endian
528 CONFIG_SYS_INIT_SP_OFFSET
530 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
531 pointer. This is needed for the temporary stack before
534 CONFIG_SYS_MIPS_CACHE_MODE
536 Cache operation mode for the MIPS CPU.
537 See also arch/mips/include/asm/mipsregs.h.
539 CONF_CM_CACHABLE_NO_WA
542 CONF_CM_CACHABLE_NONCOHERENT
546 CONF_CM_CACHABLE_ACCELERATED
548 CONFIG_SYS_XWAY_EBU_BOOTCFG
550 Special option for Lantiq XWAY SoCs for booting from NOR flash.
551 See also arch/mips/cpu/mips32/start.S.
553 CONFIG_XWAY_SWAP_BYTES
555 Enable compilation of tools/xway-swap-bytes needed for Lantiq
556 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
557 be swapped if a flash programmer is used.
560 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
562 Select high exception vectors of the ARM core, e.g., do not
563 clear the V bit of the c1 register of CP15.
566 Generic timer clock source frequency.
568 COUNTER_FREQUENCY_REAL
569 Generic timer clock source frequency if the real clock is
570 different from COUNTER_FREQUENCY, and can only be determined
574 CONFIG_TEGRA_SUPPORT_NON_SECURE
576 Support executing U-Boot in non-secure (NS) mode. Certain
577 impossible actions will be skipped if the CPU is in NS mode,
578 such as ARM architectural timer initialization.
580 - Linux Kernel Interface:
583 U-Boot stores all clock information in Hz
584 internally. For binary compatibility with older Linux
585 kernels (which expect the clocks passed in the
586 bd_info data to be in MHz) the environment variable
587 "clocks_in_mhz" can be defined so that U-Boot
588 converts clock data to MHZ before passing it to the
590 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
591 "clocks_in_mhz=1" is automatically included in the
594 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
596 When transferring memsize parameter to Linux, some versions
597 expect it to be in bytes, others in MB.
598 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
602 New kernel versions are expecting firmware settings to be
603 passed using flattened device trees (based on open firmware
607 * New libfdt-based support
608 * Adds the "fdt" command
609 * The bootm command automatically updates the fdt
611 OF_TBCLK - The timebase frequency.
612 OF_STDOUT_PATH - The path to the console device
614 boards with QUICC Engines require OF_QE to set UCC MAC
617 CONFIG_OF_BOARD_SETUP
619 Board code has addition modification that it wants to make
620 to the flat device tree before handing it off to the kernel
622 CONFIG_OF_SYSTEM_SETUP
624 Other code has addition modification that it wants to make
625 to the flat device tree before handing it off to the kernel.
626 This causes ft_system_setup() to be called before booting
631 U-Boot can detect if an IDE device is present or not.
632 If not, and this new config option is activated, U-Boot
633 removes the ATA node from the DTS before booting Linux,
634 so the Linux IDE driver does not probe the device and
635 crash. This is needed for buggy hardware (uc101) where
636 no pull down resistor is connected to the signal IDE5V_DD7.
638 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
640 This setting is mandatory for all boards that have only one
641 machine type and must be used to specify the machine type
642 number as it appears in the ARM machine registry
643 (see http://www.arm.linux.org.uk/developer/machines/).
644 Only boards that have multiple machine types supported
645 in a single configuration file and the machine type is
646 runtime discoverable, do not have to use this setting.
648 - vxWorks boot parameters:
650 bootvx constructs a valid bootline using the following
651 environments variables: bootdev, bootfile, ipaddr, netmask,
652 serverip, gatewayip, hostname, othbootargs.
653 It loads the vxWorks image pointed bootfile.
655 Note: If a "bootargs" environment is defined, it will overwride
656 the defaults discussed just above.
658 - Cache Configuration:
659 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
660 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
661 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
663 - Cache Configuration for ARM:
664 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
666 CONFIG_SYS_PL310_BASE - Physical base address of PL310
667 controller register space
672 Define this if you want support for Amba PrimeCell PL010 UARTs.
676 Define this if you want support for Amba PrimeCell PL011 UARTs.
680 If you have Amba PrimeCell PL011 UARTs, set this variable to
681 the clock speed of the UARTs.
685 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
686 define this to a list of base addresses for each (supported)
687 port. See e.g. include/configs/versatile.h
689 CONFIG_SERIAL_HW_FLOW_CONTROL
691 Define this variable to enable hw flow control in serial driver.
692 Current user of this option is drivers/serial/nsl16550.c driver
695 CONFIG_BAUDRATE - in bps
696 Select one of the baudrates listed in
697 CONFIG_SYS_BAUDRATE_TABLE, see below.
701 Only needed when CONFIG_BOOTDELAY is enabled;
702 define a command string that is automatically executed
703 when no character is read on the console interface
704 within "Boot Delay" after reset.
707 This can be used to pass arguments to the bootm
708 command. The value of CONFIG_BOOTARGS goes into the
709 environment value "bootargs".
711 CONFIG_RAMBOOT and CONFIG_NFSBOOT
712 The value of these goes into the environment as
713 "ramboot" and "nfsboot" respectively, and can be used
714 as a convenience, when switching between booting from
718 CONFIG_BOOTCOUNT_LIMIT
719 Implements a mechanism for detecting a repeating reboot
721 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
724 If no softreset save registers are found on the hardware
725 "bootcount" is stored in the environment. To prevent a
726 saveenv on all reboots, the environment variable
727 "upgrade_available" is used. If "upgrade_available" is
728 0, "bootcount" is always 0, if "upgrade_available" is
729 1 "bootcount" is incremented in the environment.
730 So the Userspace Applikation must set the "upgrade_available"
731 and "bootcount" variable to 0, if a boot was successfully.
736 When this option is #defined, the existence of the
737 environment variable "preboot" will be checked
738 immediately before starting the CONFIG_BOOTDELAY
739 countdown and/or running the auto-boot command resp.
740 entering interactive mode.
742 This feature is especially useful when "preboot" is
743 automatically generated or modified. For an example
744 see the LWMON board specific code: here "preboot" is
745 modified when the user holds down a certain
746 combination of keys on the (special) keyboard when
749 - Serial Download Echo Mode:
751 If defined to 1, all characters received during a
752 serial download (using the "loads" command) are
753 echoed back. This might be needed by some terminal
754 emulations (like "cu"), but may as well just take
755 time on others. This setting #define's the initial
756 value of the "loads_echo" environment variable.
758 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
760 Select one of the baudrates listed in
761 CONFIG_SYS_BAUDRATE_TABLE, see below.
764 Monitor commands can be included or excluded
765 from the build by using the #include files
766 <config_cmd_all.h> and #undef'ing unwanted
767 commands, or adding #define's for wanted commands.
769 The default command configuration includes all commands
770 except those marked below with a "*".
772 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
773 CONFIG_CMD_ASKENV * ask for env variable
774 CONFIG_CMD_BDI bdinfo
775 CONFIG_CMD_BOOTD bootd
776 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
777 CONFIG_CMD_CACHE * icache, dcache
778 CONFIG_CMD_CONSOLE coninfo
779 CONFIG_CMD_DHCP * DHCP support
780 CONFIG_CMD_DIAG * Diagnostics
781 CONFIG_CMD_ECHO echo arguments
782 CONFIG_CMD_EDITENV edit env variable
783 CONFIG_CMD_ELF * bootelf, bootvx
784 CONFIG_CMD_ENV_EXISTS * check existence of env variable
785 CONFIG_CMD_EXPORTENV * export the environment
786 CONFIG_CMD_EXT2 * ext2 command support
787 CONFIG_CMD_EXT4 * ext4 command support
788 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
789 that work for multiple fs types
790 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
791 CONFIG_CMD_SAVEENV saveenv
792 CONFIG_CMD_FLASH flinfo, erase, protect
793 CONFIG_CMD_FPGA FPGA device initialization support
794 CONFIG_CMD_GO * the 'go' command (exec code)
795 CONFIG_CMD_GREPENV * search environment
796 CONFIG_CMD_I2C * I2C serial bus support
797 CONFIG_CMD_IMI iminfo
798 CONFIG_CMD_IMLS List all images found in NOR flash
799 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
800 CONFIG_CMD_IMPORTENV * import an environment
801 CONFIG_CMD_INI * import data from an ini file into the env
802 CONFIG_CMD_ITEST Integer/string test of 2 values
803 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
804 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
806 CONFIG_CMD_LOADB loadb
807 CONFIG_CMD_LOADS loads
808 CONFIG_CMD_MD5SUM * print md5 message digest
809 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
810 CONFIG_CMD_MEMINFO * Display detailed memory information
811 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
813 CONFIG_CMD_MEMTEST * mtest
814 CONFIG_CMD_MISC Misc functions like sleep etc
815 CONFIG_CMD_MMC * MMC memory mapped support
816 CONFIG_CMD_MII * MII utility commands
817 CONFIG_CMD_MTDPARTS * MTD partition support
818 CONFIG_CMD_NAND * NAND support
819 CONFIG_CMD_NET bootp, tftpboot, rarpboot
820 CONFIG_CMD_NFS NFS support
821 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
822 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
823 CONFIG_CMD_PCI * pciinfo
824 CONFIG_CMD_PCMCIA * PCMCIA support
825 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
827 CONFIG_CMD_PORTIO * Port I/O
828 CONFIG_CMD_READ * Read raw data from partition
829 CONFIG_CMD_REGINFO * Register dump
830 CONFIG_CMD_RUN run command in env variable
831 CONFIG_CMD_SANDBOX * sb command to access sandbox features
832 CONFIG_CMD_SAVES * save S record dump
833 CONFIG_SCSI * SCSI Support
834 CONFIG_CMD_SDRAM * print SDRAM configuration information
835 (requires CONFIG_CMD_I2C)
836 CONFIG_CMD_SETGETDCR Support for DCR Register access
838 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
839 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
840 CONFIG_CMD_SOURCE "source" command Support
841 CONFIG_CMD_SPI * SPI serial bus support
842 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
843 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
844 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
845 CONFIG_CMD_TIMER * access to the system tick timer
846 CONFIG_CMD_USB * USB support
847 CONFIG_CMD_CDP * Cisco Discover Protocol support
848 CONFIG_CMD_MFSL * Microblaze FSL support
849 CONFIG_CMD_XIMG Load part of Multi Image
850 CONFIG_CMD_UUID * Generate random UUID or GUID string
852 EXAMPLE: If you want all functions except of network
853 support you can write:
855 #include "config_cmd_all.h"
856 #undef CONFIG_CMD_NET
859 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
861 Note: Don't enable the "icache" and "dcache" commands
862 (configuration option CONFIG_CMD_CACHE) unless you know
863 what you (and your U-Boot users) are doing. Data
864 cache cannot be enabled on systems like the
865 8260 (where accesses to the IMMR region must be
866 uncached), and it cannot be disabled on all other
867 systems where we (mis-) use the data cache to hold an
868 initial stack and some data.
871 XXX - this list needs to get updated!
873 - Removal of commands
874 If no commands are needed to boot, you can disable
875 CONFIG_CMDLINE to remove them. In this case, the command line
876 will not be available, and when U-Boot wants to execute the
877 boot command (on start-up) it will call board_run_command()
878 instead. This can reduce image size significantly for very
879 simple boot procedures.
881 - Regular expression support:
883 If this variable is defined, U-Boot is linked against
884 the SLRE (Super Light Regular Expression) library,
885 which adds regex support to some commands, as for
886 example "env grep" and "setexpr".
890 If this variable is defined, U-Boot will use a device tree
891 to configure its devices, instead of relying on statically
892 compiled #defines in the board file. This option is
893 experimental and only available on a few boards. The device
894 tree is available in the global data as gd->fdt_blob.
896 U-Boot needs to get its device tree from somewhere. This can
897 be done using one of the three options below:
900 If this variable is defined, U-Boot will embed a device tree
901 binary in its image. This device tree file should be in the
902 board directory and called <soc>-<board>.dts. The binary file
903 is then picked up in board_init_f() and made available through
904 the global data structure as gd->blob.
907 If this variable is defined, U-Boot will build a device tree
908 binary. It will be called u-boot.dtb. Architecture-specific
909 code will locate it at run-time. Generally this works by:
911 cat u-boot.bin u-boot.dtb >image.bin
913 and in fact, U-Boot does this for you, creating a file called
914 u-boot-dtb.bin which is useful in the common case. You can
915 still use the individual files if you need something more
919 If this variable is defined, U-Boot will use the device tree
920 provided by the board at runtime instead of embedding one with
921 the image. Only boards defining board_fdt_blob_setup() support
922 this option (see include/fdtdec.h file).
926 If this variable is defined, it enables watchdog
927 support for the SoC. There must be support in the SoC
928 specific code for a watchdog. When supported for a
929 specific SoC is available, then no further board specific
930 code should be needed to use it.
933 When using a watchdog circuitry external to the used
934 SoC, then define this variable and provide board
935 specific code for the "hw_watchdog_reset" function.
937 CONFIG_AT91_HW_WDT_TIMEOUT
938 specify the timeout in seconds. default 2 seconds.
941 CONFIG_VERSION_VARIABLE
942 If this variable is defined, an environment variable
943 named "ver" is created by U-Boot showing the U-Boot
944 version as printed by the "version" command.
945 Any change to this variable will be reverted at the
950 When CONFIG_CMD_DATE is selected, the type of the RTC
951 has to be selected, too. Define exactly one of the
954 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
955 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
956 CONFIG_RTC_MC146818 - use MC146818 RTC
957 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
958 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
959 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
960 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
961 CONFIG_RTC_DS164x - use Dallas DS164x RTC
962 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
963 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
964 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
965 CONFIG_SYS_RV3029_TCR - enable trickle charger on
968 Note that if the RTC uses I2C, then the I2C interface
969 must also be configured. See I2C Support, below.
972 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
974 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
975 chip-ngpio pairs that tell the PCA953X driver the number of
976 pins supported by a particular chip.
978 Note that if the GPIO device uses I2C, then the I2C interface
979 must also be configured. See I2C Support, below.
982 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
983 accesses and can checksum them or write a list of them out
984 to memory. See the 'iotrace' command for details. This is
985 useful for testing device drivers since it can confirm that
986 the driver behaves the same way before and after a code
987 change. Currently this is supported on sandbox and arm. To
988 add support for your architecture, add '#include <iotrace.h>'
989 to the bottom of arch/<arch>/include/asm/io.h and test.
991 Example output from the 'iotrace stats' command is below.
992 Note that if the trace buffer is exhausted, the checksum will
993 still continue to operate.
996 Start: 10000000 (buffer start address)
997 Size: 00010000 (buffer size)
998 Offset: 00000120 (current buffer offset)
999 Output: 10000120 (start + offset)
1000 Count: 00000018 (number of trace records)
1001 CRC32: 9526fb66 (CRC32 of all trace records)
1003 - Timestamp Support:
1005 When CONFIG_TIMESTAMP is selected, the timestamp
1006 (date and time) of an image is printed by image
1007 commands like bootm or iminfo. This option is
1008 automatically enabled when you select CONFIG_CMD_DATE .
1010 - Partition Labels (disklabels) Supported:
1011 Zero or more of the following:
1012 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1013 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1014 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1015 bootloader. Note 2TB partition limit; see
1017 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1019 If IDE or SCSI support is enabled (CONFIG_IDE or
1020 CONFIG_SCSI) you must configure support for at
1021 least one non-MTD partition type as well.
1024 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1025 board configurations files but used nowhere!
1027 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1028 be performed by calling the function
1029 ide_set_reset(int reset)
1030 which has to be defined in a board specific file
1035 Set this to enable ATAPI support.
1040 Set this to enable support for disks larger than 137GB
1041 Also look at CONFIG_SYS_64BIT_LBA.
1042 Whithout these , LBA48 support uses 32bit variables and will 'only'
1043 support disks up to 2.1TB.
1045 CONFIG_SYS_64BIT_LBA:
1046 When enabled, makes the IDE subsystem use 64bit sector addresses.
1050 At the moment only there is only support for the
1051 SYM53C8XX SCSI controller; define
1052 CONFIG_SCSI_SYM53C8XX to enable it.
1054 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1055 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1056 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1057 maximum numbers of LUNs, SCSI ID's and target
1059 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1061 The environment variable 'scsidevs' is set to the number of
1062 SCSI devices found during the last scan.
1064 - NETWORK Support (PCI):
1066 Support for Intel 8254x/8257x gigabit chips.
1069 Utility code for direct access to the SPI bus on Intel 8257x.
1070 This does not do anything useful unless you set at least one
1071 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1073 CONFIG_E1000_SPI_GENERIC
1074 Allow generic access to the SPI bus on the Intel 8257x, for
1075 example with the "sspi" command.
1078 Management command for E1000 devices. When used on devices
1079 with SPI support you can reprogram the EEPROM from U-Boot.
1082 Support for Intel 82557/82559/82559ER chips.
1083 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1084 write routine for first time initialisation.
1087 Support for Digital 2114x chips.
1088 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1089 modem chip initialisation (KS8761/QS6611).
1092 Support for National dp83815 chips.
1095 Support for National dp8382[01] gigabit chips.
1097 - NETWORK Support (other):
1099 CONFIG_DRIVER_AT91EMAC
1100 Support for AT91RM9200 EMAC.
1103 Define this to use reduced MII inteface
1105 CONFIG_DRIVER_AT91EMAC_QUIET
1106 If this defined, the driver is quiet.
1107 The driver doen't show link status messages.
1109 CONFIG_CALXEDA_XGMAC
1110 Support for the Calxeda XGMAC device
1113 Support for SMSC's LAN91C96 chips.
1115 CONFIG_LAN91C96_USE_32_BIT
1116 Define this to enable 32 bit addressing
1119 Support for SMSC's LAN91C111 chip
1121 CONFIG_SMC91111_BASE
1122 Define this to hold the physical address
1123 of the device (I/O space)
1125 CONFIG_SMC_USE_32_BIT
1126 Define this if data bus is 32 bits
1128 CONFIG_SMC_USE_IOFUNCS
1129 Define this to use i/o functions instead of macros
1130 (some hardware wont work with macros)
1132 CONFIG_DRIVER_TI_EMAC
1133 Support for davinci emac
1135 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1136 Define this if you have more then 3 PHYs.
1139 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1141 CONFIG_FTGMAC100_EGIGA
1142 Define this to use GE link update with gigabit PHY.
1143 Define this if FTGMAC100 is connected to gigabit PHY.
1144 If your system has 10/100 PHY only, it might not occur
1145 wrong behavior. Because PHY usually return timeout or
1146 useless data when polling gigabit status and gigabit
1147 control registers. This behavior won't affect the
1148 correctnessof 10/100 link speed update.
1151 Support for SMSC's LAN911x and LAN921x chips
1154 Define this to hold the physical address
1155 of the device (I/O space)
1157 CONFIG_SMC911X_32_BIT
1158 Define this if data bus is 32 bits
1160 CONFIG_SMC911X_16_BIT
1161 Define this if data bus is 16 bits. If your processor
1162 automatically converts one 32 bit word to two 16 bit
1163 words you may also try CONFIG_SMC911X_32_BIT.
1166 Support for Renesas on-chip Ethernet controller
1168 CONFIG_SH_ETHER_USE_PORT
1169 Define the number of ports to be used
1171 CONFIG_SH_ETHER_PHY_ADDR
1172 Define the ETH PHY's address
1174 CONFIG_SH_ETHER_CACHE_WRITEBACK
1175 If this option is set, the driver enables cache flush.
1179 Support for PWM module on the imx6.
1183 Support TPM devices.
1185 CONFIG_TPM_TIS_INFINEON
1186 Support for Infineon i2c bus TPM devices. Only one device
1187 per system is supported at this time.
1189 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1190 Define the burst count bytes upper limit
1193 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1195 CONFIG_TPM_ST33ZP24_I2C
1196 Support for STMicroelectronics ST33ZP24 I2C devices.
1197 Requires TPM_ST33ZP24 and I2C.
1199 CONFIG_TPM_ST33ZP24_SPI
1200 Support for STMicroelectronics ST33ZP24 SPI devices.
1201 Requires TPM_ST33ZP24 and SPI.
1203 CONFIG_TPM_ATMEL_TWI
1204 Support for Atmel TWI TPM device. Requires I2C support.
1207 Support for generic parallel port TPM devices. Only one device
1208 per system is supported at this time.
1210 CONFIG_TPM_TIS_BASE_ADDRESS
1211 Base address where the generic TPM device is mapped
1212 to. Contemporary x86 systems usually map it at
1216 Add tpm monitor functions.
1217 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1218 provides monitor access to authorized functions.
1221 Define this to enable the TPM support library which provides
1222 functional interfaces to some TPM commands.
1223 Requires support for a TPM device.
1225 CONFIG_TPM_AUTH_SESSIONS
1226 Define this to enable authorized functions in the TPM library.
1227 Requires CONFIG_TPM and CONFIG_SHA1.
1230 At the moment only the UHCI host controller is
1231 supported (PIP405, MIP405); define
1232 CONFIG_USB_UHCI to enable it.
1233 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1234 and define CONFIG_USB_STORAGE to enable the USB
1237 Supported are USB Keyboards and USB Floppy drives
1240 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1241 txfilltuning field in the EHCI controller on reset.
1243 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1244 HW module registers.
1247 Define the below if you wish to use the USB console.
1248 Once firmware is rebuilt from a serial console issue the
1249 command "setenv stdin usbtty; setenv stdout usbtty" and
1250 attach your USB cable. The Unix command "dmesg" should print
1251 it has found a new device. The environment variable usbtty
1252 can be set to gserial or cdc_acm to enable your device to
1253 appear to a USB host as a Linux gserial device or a
1254 Common Device Class Abstract Control Model serial device.
1255 If you select usbtty = gserial you should be able to enumerate
1257 # modprobe usbserial vendor=0xVendorID product=0xProductID
1258 else if using cdc_acm, simply setting the environment
1259 variable usbtty to be cdc_acm should suffice. The following
1260 might be defined in YourBoardName.h
1263 Define this to build a UDC device
1266 Define this to have a tty type of device available to
1267 talk to the UDC device
1270 Define this to enable the high speed support for usb
1271 device and usbtty. If this feature is enabled, a routine
1272 int is_usbd_high_speed(void)
1273 also needs to be defined by the driver to dynamically poll
1274 whether the enumeration has succeded at high speed or full
1277 CONFIG_SYS_CONSOLE_IS_IN_ENV
1278 Define this if you want stdin, stdout &/or stderr to
1281 If you have a USB-IF assigned VendorID then you may wish to
1282 define your own vendor specific values either in BoardName.h
1283 or directly in usbd_vendor_info.h. If you don't define
1284 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1285 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1286 should pretend to be a Linux device to it's target host.
1288 CONFIG_USBD_MANUFACTURER
1289 Define this string as the name of your company for
1290 - CONFIG_USBD_MANUFACTURER "my company"
1292 CONFIG_USBD_PRODUCT_NAME
1293 Define this string as the name of your product
1294 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1296 CONFIG_USBD_VENDORID
1297 Define this as your assigned Vendor ID from the USB
1298 Implementors Forum. This *must* be a genuine Vendor ID
1299 to avoid polluting the USB namespace.
1300 - CONFIG_USBD_VENDORID 0xFFFF
1302 CONFIG_USBD_PRODUCTID
1303 Define this as the unique Product ID
1305 - CONFIG_USBD_PRODUCTID 0xFFFF
1307 - ULPI Layer Support:
1308 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1309 the generic ULPI layer. The generic layer accesses the ULPI PHY
1310 via the platform viewport, so you need both the genric layer and
1311 the viewport enabled. Currently only Chipidea/ARC based
1312 viewport is supported.
1313 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1314 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1315 If your ULPI phy needs a different reference clock than the
1316 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1317 the appropriate value in Hz.
1320 The MMC controller on the Intel PXA is supported. To
1321 enable this define CONFIG_MMC. The MMC can be
1322 accessed from the boot prompt by mapping the device
1323 to physical memory similar to flash. Command line is
1324 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1325 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1328 Support for Renesas on-chip MMCIF controller
1330 CONFIG_SH_MMCIF_ADDR
1331 Define the base address of MMCIF registers
1334 Define the clock frequency for MMCIF
1336 CONFIG_SUPPORT_EMMC_BOOT
1337 Enable some additional features of the eMMC boot partitions.
1339 CONFIG_SUPPORT_EMMC_RPMB
1340 Enable the commands for reading, writing and programming the
1341 key for the Replay Protection Memory Block partition in eMMC.
1343 - USB Device Firmware Update (DFU) class support:
1344 CONFIG_USB_FUNCTION_DFU
1345 This enables the USB portion of the DFU USB class
1348 This enables the command "dfu" which is used to have
1349 U-Boot create a DFU class device via USB. This command
1350 requires that the "dfu_alt_info" environment variable be
1351 set and define the alt settings to expose to the host.
1354 This enables support for exposing (e)MMC devices via DFU.
1357 This enables support for exposing NAND devices via DFU.
1360 This enables support for exposing RAM via DFU.
1361 Note: DFU spec refer to non-volatile memory usage, but
1362 allow usages beyond the scope of spec - here RAM usage,
1363 one that would help mostly the developer.
1365 CONFIG_SYS_DFU_DATA_BUF_SIZE
1366 Dfu transfer uses a buffer before writing data to the
1367 raw storage device. Make the size (in bytes) of this buffer
1368 configurable. The size of this buffer is also configurable
1369 through the "dfu_bufsiz" environment variable.
1371 CONFIG_SYS_DFU_MAX_FILE_SIZE
1372 When updating files rather than the raw storage device,
1373 we use a static buffer to copy the file into and then write
1374 the buffer once we've been given the whole file. Define
1375 this to the maximum filesize (in bytes) for the buffer.
1376 Default is 4 MiB if undefined.
1378 DFU_DEFAULT_POLL_TIMEOUT
1379 Poll timeout [ms], is the timeout a device can send to the
1380 host. The host must wait for this timeout before sending
1381 a subsequent DFU_GET_STATUS request to the device.
1383 DFU_MANIFEST_POLL_TIMEOUT
1384 Poll timeout [ms], which the device sends to the host when
1385 entering dfuMANIFEST state. Host waits this timeout, before
1386 sending again an USB request to the device.
1388 - USB Device Android Fastboot support:
1389 CONFIG_USB_FUNCTION_FASTBOOT
1390 This enables the USB part of the fastboot gadget
1393 This enables the command "fastboot" which enables the Android
1394 fastboot mode for the platform's USB device. Fastboot is a USB
1395 protocol for downloading images, flashing and device control
1396 used on Android devices.
1397 See doc/README.android-fastboot for more information.
1399 CONFIG_ANDROID_BOOT_IMAGE
1400 This enables support for booting images which use the Android
1401 image format header.
1403 CONFIG_FASTBOOT_BUF_ADDR
1404 The fastboot protocol requires a large memory buffer for
1405 downloads. Define this to the starting RAM address to use for
1408 CONFIG_FASTBOOT_BUF_SIZE
1409 The fastboot protocol requires a large memory buffer for
1410 downloads. This buffer should be as large as possible for a
1411 platform. Define this to the size available RAM for fastboot.
1413 CONFIG_FASTBOOT_FLASH
1414 The fastboot protocol includes a "flash" command for writing
1415 the downloaded image to a non-volatile storage device. Define
1416 this to enable the "fastboot flash" command.
1418 CONFIG_FASTBOOT_FLASH_MMC_DEV
1419 The fastboot "flash" command requires additional information
1420 regarding the non-volatile storage device. Define this to
1421 the eMMC device that fastboot should use to store the image.
1423 CONFIG_FASTBOOT_GPT_NAME
1424 The fastboot "flash" command supports writing the downloaded
1425 image to the Protective MBR and the Primary GUID Partition
1426 Table. (Additionally, this downloaded image is post-processed
1427 to generate and write the Backup GUID Partition Table.)
1428 This occurs when the specified "partition name" on the
1429 "fastboot flash" command line matches this value.
1430 The default is "gpt" if undefined.
1432 CONFIG_FASTBOOT_MBR_NAME
1433 The fastboot "flash" command supports writing the downloaded
1435 This occurs when the "partition name" specified on the
1436 "fastboot flash" command line matches this value.
1437 If not defined the default value "mbr" is used.
1439 - Journaling Flash filesystem support:
1441 Define these for a default partition on a NAND device
1443 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1444 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1445 Define these for a default partition on a NOR device
1448 See Kconfig help for available keyboard drivers.
1452 Define this to enable a custom keyboard support.
1453 This simply calls drv_keyboard_init() which must be
1454 defined in your board-specific files. This option is deprecated
1455 and is only used by novena. For new boards, use driver model
1460 Enable the Freescale DIU video driver. Reference boards for
1461 SOCs that have a DIU should define this macro to enable DIU
1462 support, and should also define these other macros:
1467 CONFIG_VIDEO_SW_CURSOR
1468 CONFIG_VGA_AS_SINGLE_DEVICE
1470 CONFIG_VIDEO_BMP_LOGO
1472 The DIU driver will look for the 'video-mode' environment
1473 variable, and if defined, enable the DIU as a console during
1474 boot. See the documentation file doc/README.video for a
1475 description of this variable.
1477 - LCD Support: CONFIG_LCD
1479 Define this to enable LCD support (for output to LCD
1480 display); also select one of the supported displays
1481 by defining one of these:
1485 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1487 CONFIG_NEC_NL6448AC33:
1489 NEC NL6448AC33-18. Active, color, single scan.
1491 CONFIG_NEC_NL6448BC20
1493 NEC NL6448BC20-08. 6.5", 640x480.
1494 Active, color, single scan.
1496 CONFIG_NEC_NL6448BC33_54
1498 NEC NL6448BC33-54. 10.4", 640x480.
1499 Active, color, single scan.
1503 Sharp 320x240. Active, color, single scan.
1504 It isn't 16x9, and I am not sure what it is.
1506 CONFIG_SHARP_LQ64D341
1508 Sharp LQ64D341 display, 640x480.
1509 Active, color, single scan.
1513 HLD1045 display, 640x480.
1514 Active, color, single scan.
1518 Optrex CBL50840-2 NF-FW 99 22 M5
1520 Hitachi LMG6912RPFC-00T
1524 320x240. Black & white.
1526 CONFIG_LCD_ALIGNMENT
1528 Normally the LCD is page-aligned (typically 4KB). If this is
1529 defined then the LCD will be aligned to this value instead.
1530 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1531 here, since it is cheaper to change data cache settings on
1532 a per-section basis.
1537 Sometimes, for example if the display is mounted in portrait
1538 mode or even if it's mounted landscape but rotated by 180degree,
1539 we need to rotate our content of the display relative to the
1540 framebuffer, so that user can read the messages which are
1542 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1543 initialized with a given rotation from "vl_rot" out of
1544 "vidinfo_t" which is provided by the board specific code.
1545 The value for vl_rot is coded as following (matching to
1546 fbcon=rotate:<n> linux-kernel commandline):
1547 0 = no rotation respectively 0 degree
1548 1 = 90 degree rotation
1549 2 = 180 degree rotation
1550 3 = 270 degree rotation
1552 If CONFIG_LCD_ROTATION is not defined, the console will be
1553 initialized with 0degree rotation.
1557 Support drawing of RLE8-compressed bitmaps on the LCD.
1561 Enables an 'i2c edid' command which can read EDID
1562 information over I2C from an attached LCD display.
1564 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1566 If this option is set, the environment is checked for
1567 a variable "splashimage". If found, the usual display
1568 of logo, copyright and system information on the LCD
1569 is suppressed and the BMP image at the address
1570 specified in "splashimage" is loaded instead. The
1571 console is redirected to the "nulldev", too. This
1572 allows for a "silent" boot where a splash screen is
1573 loaded very quickly after power-on.
1575 CONFIG_SPLASHIMAGE_GUARD
1577 If this option is set, then U-Boot will prevent the environment
1578 variable "splashimage" from being set to a problematic address
1579 (see doc/README.displaying-bmps).
1580 This option is useful for targets where, due to alignment
1581 restrictions, an improperly aligned BMP image will cause a data
1582 abort. If you think you will not have problems with unaligned
1583 accesses (for example because your toolchain prevents them)
1584 there is no need to set this option.
1586 CONFIG_SPLASH_SCREEN_ALIGN
1588 If this option is set the splash image can be freely positioned
1589 on the screen. Environment variable "splashpos" specifies the
1590 position as "x,y". If a positive number is given it is used as
1591 number of pixel from left/top. If a negative number is given it
1592 is used as number of pixel from right/bottom. You can also
1593 specify 'm' for centering the image.
1596 setenv splashpos m,m
1597 => image at center of screen
1599 setenv splashpos 30,20
1600 => image at x = 30 and y = 20
1602 setenv splashpos -10,m
1603 => vertically centered image
1604 at x = dspWidth - bmpWidth - 9
1606 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1608 If this option is set, additionally to standard BMP
1609 images, gzipped BMP images can be displayed via the
1610 splashscreen support or the bmp command.
1612 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1614 If this option is set, 8-bit RLE compressed BMP images
1615 can be displayed via the splashscreen support or the
1618 - Compression support:
1621 Enabled by default to support gzip compressed images.
1625 If this option is set, support for bzip2 compressed
1626 images is included. If not, only uncompressed and gzip
1627 compressed images are supported.
1629 NOTE: the bzip2 algorithm requires a lot of RAM, so
1630 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1635 If this option is set, support for LZO compressed images
1641 The address of PHY on MII bus.
1643 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1645 The clock frequency of the MII bus
1649 If this option is set, support for speed/duplex
1650 detection of gigabit PHY is included.
1652 CONFIG_PHY_RESET_DELAY
1654 Some PHY like Intel LXT971A need extra delay after
1655 reset before any MII register access is possible.
1656 For such PHY, set this option to the usec delay
1657 required. (minimum 300usec for LXT971A)
1659 CONFIG_PHY_CMD_DELAY (ppc4xx)
1661 Some PHY like Intel LXT971A need extra delay after
1662 command issued before MII status register can be read
1667 Define a default value for the IP address to use for
1668 the default Ethernet interface, in case this is not
1669 determined through e.g. bootp.
1670 (Environment variable "ipaddr")
1672 - Server IP address:
1675 Defines a default value for the IP address of a TFTP
1676 server to contact when using the "tftboot" command.
1677 (Environment variable "serverip")
1679 CONFIG_KEEP_SERVERADDR
1681 Keeps the server's MAC address, in the env 'serveraddr'
1682 for passing to bootargs (like Linux's netconsole option)
1684 - Gateway IP address:
1687 Defines a default value for the IP address of the
1688 default router where packets to other networks are
1690 (Environment variable "gatewayip")
1695 Defines a default value for the subnet mask (or
1696 routing prefix) which is used to determine if an IP
1697 address belongs to the local subnet or needs to be
1698 forwarded through a router.
1699 (Environment variable "netmask")
1701 - Multicast TFTP Mode:
1704 Defines whether you want to support multicast TFTP as per
1705 rfc-2090; for example to work with atftp. Lets lots of targets
1706 tftp down the same boot image concurrently. Note: the Ethernet
1707 driver in use must provide a function: mcast() to join/leave a
1710 - BOOTP Recovery Mode:
1711 CONFIG_BOOTP_RANDOM_DELAY
1713 If you have many targets in a network that try to
1714 boot using BOOTP, you may want to avoid that all
1715 systems send out BOOTP requests at precisely the same
1716 moment (which would happen for instance at recovery
1717 from a power failure, when all systems will try to
1718 boot, thus flooding the BOOTP server. Defining
1719 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1720 inserted before sending out BOOTP requests. The
1721 following delays are inserted then:
1723 1st BOOTP request: delay 0 ... 1 sec
1724 2nd BOOTP request: delay 0 ... 2 sec
1725 3rd BOOTP request: delay 0 ... 4 sec
1727 BOOTP requests: delay 0 ... 8 sec
1729 CONFIG_BOOTP_ID_CACHE_SIZE
1731 BOOTP packets are uniquely identified using a 32-bit ID. The
1732 server will copy the ID from client requests to responses and
1733 U-Boot will use this to determine if it is the destination of
1734 an incoming response. Some servers will check that addresses
1735 aren't in use before handing them out (usually using an ARP
1736 ping) and therefore take up to a few hundred milliseconds to
1737 respond. Network congestion may also influence the time it
1738 takes for a response to make it back to the client. If that
1739 time is too long, U-Boot will retransmit requests. In order
1740 to allow earlier responses to still be accepted after these
1741 retransmissions, U-Boot's BOOTP client keeps a small cache of
1742 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1743 cache. The default is to keep IDs for up to four outstanding
1744 requests. Increasing this will allow U-Boot to accept offers
1745 from a BOOTP client in networks with unusually high latency.
1747 - DHCP Advanced Options:
1748 You can fine tune the DHCP functionality by defining
1749 CONFIG_BOOTP_* symbols:
1751 CONFIG_BOOTP_SUBNETMASK
1752 CONFIG_BOOTP_GATEWAY
1753 CONFIG_BOOTP_HOSTNAME
1754 CONFIG_BOOTP_NISDOMAIN
1755 CONFIG_BOOTP_BOOTPATH
1756 CONFIG_BOOTP_BOOTFILESIZE
1759 CONFIG_BOOTP_SEND_HOSTNAME
1760 CONFIG_BOOTP_NTPSERVER
1761 CONFIG_BOOTP_TIMEOFFSET
1762 CONFIG_BOOTP_VENDOREX
1763 CONFIG_BOOTP_MAY_FAIL
1765 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1766 environment variable, not the BOOTP server.
1768 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1769 after the configured retry count, the call will fail
1770 instead of starting over. This can be used to fail over
1771 to Link-local IP address configuration if the DHCP server
1774 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1775 serverip from a DHCP server, it is possible that more
1776 than one DNS serverip is offered to the client.
1777 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1778 serverip will be stored in the additional environment
1779 variable "dnsip2". The first DNS serverip is always
1780 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1783 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1784 to do a dynamic update of a DNS server. To do this, they
1785 need the hostname of the DHCP requester.
1786 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1787 of the "hostname" environment variable is passed as
1788 option 12 to the DHCP server.
1790 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1792 A 32bit value in microseconds for a delay between
1793 receiving a "DHCP Offer" and sending the "DHCP Request".
1794 This fixes a problem with certain DHCP servers that don't
1795 respond 100% of the time to a "DHCP request". E.g. On an
1796 AT91RM9200 processor running at 180MHz, this delay needed
1797 to be *at least* 15,000 usec before a Windows Server 2003
1798 DHCP server would reply 100% of the time. I recommend at
1799 least 50,000 usec to be safe. The alternative is to hope
1800 that one of the retries will be successful but note that
1801 the DHCP timeout and retry process takes a longer than
1804 - Link-local IP address negotiation:
1805 Negotiate with other link-local clients on the local network
1806 for an address that doesn't require explicit configuration.
1807 This is especially useful if a DHCP server cannot be guaranteed
1808 to exist in all environments that the device must operate.
1810 See doc/README.link-local for more information.
1813 CONFIG_CDP_DEVICE_ID
1815 The device id used in CDP trigger frames.
1817 CONFIG_CDP_DEVICE_ID_PREFIX
1819 A two character string which is prefixed to the MAC address
1824 A printf format string which contains the ascii name of
1825 the port. Normally is set to "eth%d" which sets
1826 eth0 for the first Ethernet, eth1 for the second etc.
1828 CONFIG_CDP_CAPABILITIES
1830 A 32bit integer which indicates the device capabilities;
1831 0x00000010 for a normal host which does not forwards.
1835 An ascii string containing the version of the software.
1839 An ascii string containing the name of the platform.
1843 A 32bit integer sent on the trigger.
1845 CONFIG_CDP_POWER_CONSUMPTION
1847 A 16bit integer containing the power consumption of the
1848 device in .1 of milliwatts.
1850 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1852 A byte containing the id of the VLAN.
1854 - Status LED: CONFIG_LED_STATUS
1856 Several configurations allow to display the current
1857 status using a LED. For instance, the LED will blink
1858 fast while running U-Boot code, stop blinking as
1859 soon as a reply to a BOOTP request was received, and
1860 start blinking slow once the Linux kernel is running
1861 (supported by a status LED driver in the Linux
1862 kernel). Defining CONFIG_LED_STATUS enables this
1867 CONFIG_LED_STATUS_GPIO
1868 The status LED can be connected to a GPIO pin.
1869 In such cases, the gpio_led driver can be used as a
1870 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1871 to include the gpio_led driver in the U-Boot binary.
1873 CONFIG_GPIO_LED_INVERTED_TABLE
1874 Some GPIO connected LEDs may have inverted polarity in which
1875 case the GPIO high value corresponds to LED off state and
1876 GPIO low value corresponds to LED on state.
1877 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1878 with a list of GPIO LEDs that have inverted polarity.
1880 - I2C Support: CONFIG_SYS_I2C
1882 This enable the NEW i2c subsystem, and will allow you to use
1883 i2c commands at the u-boot command line (as long as you set
1884 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1885 based realtime clock chips or other i2c devices. See
1886 common/cmd_i2c.c for a description of the command line
1889 ported i2c driver to the new framework:
1890 - drivers/i2c/soft_i2c.c:
1891 - activate first bus with CONFIG_SYS_I2C_SOFT define
1892 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1893 for defining speed and slave address
1894 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1895 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1896 for defining speed and slave address
1897 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1898 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1899 for defining speed and slave address
1900 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1901 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1902 for defining speed and slave address
1904 - drivers/i2c/fsl_i2c.c:
1905 - activate i2c driver with CONFIG_SYS_I2C_FSL
1906 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1907 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1908 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1910 - If your board supports a second fsl i2c bus, define
1911 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1912 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1913 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1916 - drivers/i2c/tegra_i2c.c:
1917 - activate this driver with CONFIG_SYS_I2C_TEGRA
1918 - This driver adds 4 i2c buses with a fix speed from
1919 100000 and the slave addr 0!
1921 - drivers/i2c/ppc4xx_i2c.c
1922 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1923 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1924 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1926 - drivers/i2c/i2c_mxc.c
1927 - activate this driver with CONFIG_SYS_I2C_MXC
1928 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1929 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1930 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1931 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1932 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1933 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1934 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1935 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1936 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1937 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1938 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1939 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1940 If those defines are not set, default value is 100000
1941 for speed, and 0 for slave.
1943 - drivers/i2c/rcar_i2c.c:
1944 - activate this driver with CONFIG_SYS_I2C_RCAR
1945 - This driver adds 4 i2c buses
1947 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1948 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1949 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1950 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1951 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1952 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1953 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1954 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1955 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1957 - drivers/i2c/sh_i2c.c:
1958 - activate this driver with CONFIG_SYS_I2C_SH
1959 - This driver adds from 2 to 5 i2c buses
1961 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1962 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1963 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1964 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1965 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1966 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1967 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1968 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1969 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1970 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1971 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1973 - drivers/i2c/omap24xx_i2c.c
1974 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1975 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1976 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1977 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1978 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1979 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1980 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1981 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1982 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1983 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1984 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1986 - drivers/i2c/zynq_i2c.c
1987 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1988 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1989 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1991 - drivers/i2c/s3c24x0_i2c.c:
1992 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1993 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1994 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1995 with a fix speed from 100000 and the slave addr 0!
1997 - drivers/i2c/ihs_i2c.c
1998 - activate this driver with CONFIG_SYS_I2C_IHS
1999 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2000 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2001 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2002 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2003 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2004 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2005 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2006 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2007 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2008 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2009 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2010 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2011 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2012 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2013 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2014 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2015 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2016 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2017 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2018 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2019 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2023 CONFIG_SYS_NUM_I2C_BUSES
2024 Hold the number of i2c buses you want to use.
2026 CONFIG_SYS_I2C_DIRECT_BUS
2027 define this, if you don't use i2c muxes on your hardware.
2028 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2031 CONFIG_SYS_I2C_MAX_HOPS
2032 define how many muxes are maximal consecutively connected
2033 on one i2c bus. If you not use i2c muxes, omit this
2036 CONFIG_SYS_I2C_BUSES
2037 hold a list of buses you want to use, only used if
2038 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2039 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2040 CONFIG_SYS_NUM_I2C_BUSES = 9:
2042 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2043 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2044 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2045 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2046 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2047 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2048 {1, {I2C_NULL_HOP}}, \
2049 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2050 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2054 bus 0 on adapter 0 without a mux
2055 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2056 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2057 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2058 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2059 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2060 bus 6 on adapter 1 without a mux
2061 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2062 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2064 If you do not have i2c muxes on your board, omit this define.
2066 - Legacy I2C Support:
2067 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2068 then the following macros need to be defined (examples are
2069 from include/configs/lwmon.h):
2073 (Optional). Any commands necessary to enable the I2C
2074 controller or configure ports.
2076 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2080 The code necessary to make the I2C data line active
2081 (driven). If the data line is open collector, this
2084 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2088 The code necessary to make the I2C data line tri-stated
2089 (inactive). If the data line is open collector, this
2092 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2096 Code that returns true if the I2C data line is high,
2099 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2103 If <bit> is true, sets the I2C data line high. If it
2104 is false, it clears it (low).
2106 eg: #define I2C_SDA(bit) \
2107 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2108 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2112 If <bit> is true, sets the I2C clock line high. If it
2113 is false, it clears it (low).
2115 eg: #define I2C_SCL(bit) \
2116 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2117 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2121 This delay is invoked four times per clock cycle so this
2122 controls the rate of data transfer. The data rate thus
2123 is 1 / (I2C_DELAY * 4). Often defined to be something
2126 #define I2C_DELAY udelay(2)
2128 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2130 If your arch supports the generic GPIO framework (asm/gpio.h),
2131 then you may alternatively define the two GPIOs that are to be
2132 used as SCL / SDA. Any of the previous I2C_xxx macros will
2133 have GPIO-based defaults assigned to them as appropriate.
2135 You should define these to the GPIO value as given directly to
2136 the generic GPIO functions.
2138 CONFIG_SYS_I2C_INIT_BOARD
2140 When a board is reset during an i2c bus transfer
2141 chips might think that the current transfer is still
2142 in progress. On some boards it is possible to access
2143 the i2c SCLK line directly, either by using the
2144 processor pin as a GPIO or by having a second pin
2145 connected to the bus. If this option is defined a
2146 custom i2c_init_board() routine in boards/xxx/board.c
2147 is run early in the boot sequence.
2149 CONFIG_I2C_MULTI_BUS
2151 This option allows the use of multiple I2C buses, each of which
2152 must have a controller. At any point in time, only one bus is
2153 active. To switch to a different bus, use the 'i2c dev' command.
2154 Note that bus numbering is zero-based.
2156 CONFIG_SYS_I2C_NOPROBES
2158 This option specifies a list of I2C devices that will be skipped
2159 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2160 is set, specify a list of bus-device pairs. Otherwise, specify
2161 a 1D array of device addresses
2164 #undef CONFIG_I2C_MULTI_BUS
2165 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2167 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2169 #define CONFIG_I2C_MULTI_BUS
2170 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2172 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2174 CONFIG_SYS_SPD_BUS_NUM
2176 If defined, then this indicates the I2C bus number for DDR SPD.
2177 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2179 CONFIG_SYS_RTC_BUS_NUM
2181 If defined, then this indicates the I2C bus number for the RTC.
2182 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2184 CONFIG_SOFT_I2C_READ_REPEATED_START
2186 defining this will force the i2c_read() function in
2187 the soft_i2c driver to perform an I2C repeated start
2188 between writing the address pointer and reading the
2189 data. If this define is omitted the default behaviour
2190 of doing a stop-start sequence will be used. Most I2C
2191 devices can use either method, but some require one or
2194 - SPI Support: CONFIG_SPI
2196 Enables SPI driver (so far only tested with
2197 SPI EEPROM, also an instance works with Crystal A/D and
2198 D/As on the SACSng board)
2202 Enables the driver for SPI controller on SuperH. Currently
2203 only SH7757 is supported.
2207 Enables a software (bit-bang) SPI driver rather than
2208 using hardware support. This is a general purpose
2209 driver that only requires three general I/O port pins
2210 (two outputs, one input) to function. If this is
2211 defined, the board configuration must define several
2212 SPI configuration items (port pins to use, etc). For
2213 an example, see include/configs/sacsng.h.
2217 Enables a hardware SPI driver for general-purpose reads
2218 and writes. As with CONFIG_SOFT_SPI, the board configuration
2219 must define a list of chip-select function pointers.
2220 Currently supported on some MPC8xxx processors. For an
2221 example, see include/configs/mpc8349emds.h.
2225 Enables the driver for the SPI controllers on i.MX and MXC
2226 SoCs. Currently i.MX31/35/51 are supported.
2228 CONFIG_SYS_SPI_MXC_WAIT
2229 Timeout for waiting until spi transfer completed.
2230 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2232 - FPGA Support: CONFIG_FPGA
2234 Enables FPGA subsystem.
2236 CONFIG_FPGA_<vendor>
2238 Enables support for specific chip vendors.
2241 CONFIG_FPGA_<family>
2243 Enables support for FPGA family.
2244 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2248 Specify the number of FPGA devices to support.
2250 CONFIG_SYS_FPGA_PROG_FEEDBACK
2252 Enable printing of hash marks during FPGA configuration.
2254 CONFIG_SYS_FPGA_CHECK_BUSY
2256 Enable checks on FPGA configuration interface busy
2257 status by the configuration function. This option
2258 will require a board or device specific function to
2263 If defined, a function that provides delays in the FPGA
2264 configuration driver.
2266 CONFIG_SYS_FPGA_CHECK_CTRLC
2267 Allow Control-C to interrupt FPGA configuration
2269 CONFIG_SYS_FPGA_CHECK_ERROR
2271 Check for configuration errors during FPGA bitfile
2272 loading. For example, abort during Virtex II
2273 configuration if the INIT_B line goes low (which
2274 indicated a CRC error).
2276 CONFIG_SYS_FPGA_WAIT_INIT
2278 Maximum time to wait for the INIT_B line to de-assert
2279 after PROB_B has been de-asserted during a Virtex II
2280 FPGA configuration sequence. The default time is 500
2283 CONFIG_SYS_FPGA_WAIT_BUSY
2285 Maximum time to wait for BUSY to de-assert during
2286 Virtex II FPGA configuration. The default is 5 ms.
2288 CONFIG_SYS_FPGA_WAIT_CONFIG
2290 Time to wait after FPGA configuration. The default is
2293 - Configuration Management:
2296 Some SoCs need special image types (e.g. U-Boot binary
2297 with a special header) as build targets. By defining
2298 CONFIG_BUILD_TARGET in the SoC / board header, this
2299 special image will be automatically built upon calling
2304 If defined, this string will be added to the U-Boot
2305 version information (U_BOOT_VERSION)
2307 - Vendor Parameter Protection:
2309 U-Boot considers the values of the environment
2310 variables "serial#" (Board Serial Number) and
2311 "ethaddr" (Ethernet Address) to be parameters that
2312 are set once by the board vendor / manufacturer, and
2313 protects these variables from casual modification by
2314 the user. Once set, these variables are read-only,
2315 and write or delete attempts are rejected. You can
2316 change this behaviour:
2318 If CONFIG_ENV_OVERWRITE is #defined in your config
2319 file, the write protection for vendor parameters is
2320 completely disabled. Anybody can change or delete
2323 Alternatively, if you define _both_ an ethaddr in the
2324 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2325 Ethernet address is installed in the environment,
2326 which can be changed exactly ONCE by the user. [The
2327 serial# is unaffected by this, i. e. it remains
2330 The same can be accomplished in a more flexible way
2331 for any variable by configuring the type of access
2332 to allow for those variables in the ".flags" variable
2333 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2338 Define this variable to enable the reservation of
2339 "protected RAM", i. e. RAM which is not overwritten
2340 by U-Boot. Define CONFIG_PRAM to hold the number of
2341 kB you want to reserve for pRAM. You can overwrite
2342 this default value by defining an environment
2343 variable "pram" to the number of kB you want to
2344 reserve. Note that the board info structure will
2345 still show the full amount of RAM. If pRAM is
2346 reserved, a new environment variable "mem" will
2347 automatically be defined to hold the amount of
2348 remaining RAM in a form that can be passed as boot
2349 argument to Linux, for instance like that:
2351 setenv bootargs ... mem=\${mem}
2354 This way you can tell Linux not to use this memory,
2355 either, which results in a memory region that will
2356 not be affected by reboots.
2358 *WARNING* If your board configuration uses automatic
2359 detection of the RAM size, you must make sure that
2360 this memory test is non-destructive. So far, the
2361 following board configurations are known to be
2364 IVMS8, IVML24, SPD8xx,
2365 HERMES, IP860, RPXlite, LWMON,
2368 - Access to physical memory region (> 4GB)
2369 Some basic support is provided for operations on memory not
2370 normally accessible to U-Boot - e.g. some architectures
2371 support access to more than 4GB of memory on 32-bit
2372 machines using physical address extension or similar.
2373 Define CONFIG_PHYSMEM to access this basic support, which
2374 currently only supports clearing the memory.
2379 Define this variable to stop the system in case of a
2380 fatal error, so that you have to reset it manually.
2381 This is probably NOT a good idea for an embedded
2382 system where you want the system to reboot
2383 automatically as fast as possible, but it may be
2384 useful during development since you can try to debug
2385 the conditions that lead to the situation.
2387 CONFIG_NET_RETRY_COUNT
2389 This variable defines the number of retries for
2390 network operations like ARP, RARP, TFTP, or BOOTP
2391 before giving up the operation. If not defined, a
2392 default value of 5 is used.
2396 Timeout waiting for an ARP reply in milliseconds.
2400 Timeout in milliseconds used in NFS protocol.
2401 If you encounter "ERROR: Cannot umount" in nfs command,
2402 try longer timeout such as
2403 #define CONFIG_NFS_TIMEOUT 10000UL
2405 - Command Interpreter:
2406 CONFIG_AUTO_COMPLETE
2408 Enable auto completion of commands using TAB.
2410 CONFIG_SYS_PROMPT_HUSH_PS2
2412 This defines the secondary prompt string, which is
2413 printed when the command interpreter needs more input
2414 to complete a command. Usually "> ".
2418 In the current implementation, the local variables
2419 space and global environment variables space are
2420 separated. Local variables are those you define by
2421 simply typing `name=value'. To access a local
2422 variable later on, you have write `$name' or
2423 `${name}'; to execute the contents of a variable
2424 directly type `$name' at the command prompt.
2426 Global environment variables are those you use
2427 setenv/printenv to work with. To run a command stored
2428 in such a variable, you need to use the run command,
2429 and you must not use the '$' sign to access them.
2431 To store commands and special characters in a
2432 variable, please use double quotation marks
2433 surrounding the whole text of the variable, instead
2434 of the backslashes before semicolons and special
2437 - Command Line Editing and History:
2438 CONFIG_CMDLINE_EDITING
2440 Enable editing and History functions for interactive
2441 command line input operations
2443 - Command Line PS1/PS2 support:
2444 CONFIG_CMDLINE_PS_SUPPORT
2446 Enable support for changing the command prompt string
2447 at run-time. Only static string is supported so far.
2448 The string is obtained from environment variables PS1
2451 - Default Environment:
2452 CONFIG_EXTRA_ENV_SETTINGS
2454 Define this to contain any number of null terminated
2455 strings (variable = value pairs) that will be part of
2456 the default environment compiled into the boot image.
2458 For example, place something like this in your
2459 board's config file:
2461 #define CONFIG_EXTRA_ENV_SETTINGS \
2465 Warning: This method is based on knowledge about the
2466 internal format how the environment is stored by the
2467 U-Boot code. This is NOT an official, exported
2468 interface! Although it is unlikely that this format
2469 will change soon, there is no guarantee either.
2470 You better know what you are doing here.
2472 Note: overly (ab)use of the default environment is
2473 discouraged. Make sure to check other ways to preset
2474 the environment like the "source" command or the
2477 CONFIG_ENV_VARS_UBOOT_CONFIG
2479 Define this in order to add variables describing the
2480 U-Boot build configuration to the default environment.
2481 These will be named arch, cpu, board, vendor, and soc.
2483 Enabling this option will cause the following to be defined:
2491 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2493 Define this in order to add variables describing certain
2494 run-time determined information about the hardware to the
2495 environment. These will be named board_name, board_rev.
2497 CONFIG_DELAY_ENVIRONMENT
2499 Normally the environment is loaded when the board is
2500 initialised so that it is available to U-Boot. This inhibits
2501 that so that the environment is not available until
2502 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2503 this is instead controlled by the value of
2504 /config/load-environment.
2506 - DataFlash Support:
2507 CONFIG_HAS_DATAFLASH
2509 Defining this option enables DataFlash features and
2510 allows to read/write in Dataflash via the standard
2513 - Serial Flash support
2516 Defining this option enables SPI flash commands
2517 'sf probe/read/write/erase/update'.
2519 Usage requires an initial 'probe' to define the serial
2520 flash parameters, followed by read/write/erase/update
2523 The following defaults may be provided by the platform
2524 to handle the common case when only a single serial
2525 flash is present on the system.
2527 CONFIG_SF_DEFAULT_BUS Bus identifier
2528 CONFIG_SF_DEFAULT_CS Chip-select
2529 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2530 CONFIG_SF_DEFAULT_SPEED in Hz
2534 Define this option to include a destructive SPI flash
2537 - SystemACE Support:
2540 Adding this option adds support for Xilinx SystemACE
2541 chips attached via some sort of local bus. The address
2542 of the chip must also be defined in the
2543 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2545 #define CONFIG_SYSTEMACE
2546 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2548 When SystemACE support is added, the "ace" device type
2549 becomes available to the fat commands, i.e. fatls.
2551 - TFTP Fixed UDP Port:
2554 If this is defined, the environment variable tftpsrcp
2555 is used to supply the TFTP UDP source port value.
2556 If tftpsrcp isn't defined, the normal pseudo-random port
2557 number generator is used.
2559 Also, the environment variable tftpdstp is used to supply
2560 the TFTP UDP destination port value. If tftpdstp isn't
2561 defined, the normal port 69 is used.
2563 The purpose for tftpsrcp is to allow a TFTP server to
2564 blindly start the TFTP transfer using the pre-configured
2565 target IP address and UDP port. This has the effect of
2566 "punching through" the (Windows XP) firewall, allowing
2567 the remainder of the TFTP transfer to proceed normally.
2568 A better solution is to properly configure the firewall,
2569 but sometimes that is not allowed.
2571 - bootcount support:
2572 CONFIG_BOOTCOUNT_LIMIT
2574 This enables the bootcounter support, see:
2575 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2578 enable special bootcounter support on at91sam9xe based boards.
2580 enable special bootcounter support on da850 based boards.
2581 CONFIG_BOOTCOUNT_RAM
2582 enable support for the bootcounter in RAM
2583 CONFIG_BOOTCOUNT_I2C
2584 enable support for the bootcounter on an i2c (like RTC) device.
2585 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2586 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2588 CONFIG_BOOTCOUNT_ALEN = address len
2590 - Show boot progress:
2591 CONFIG_SHOW_BOOT_PROGRESS
2593 Defining this option allows to add some board-
2594 specific code (calling a user-provided function
2595 "show_boot_progress(int)") that enables you to show
2596 the system's boot progress on some display (for
2597 example, some LED's) on your board. At the moment,
2598 the following checkpoints are implemented:
2601 Legacy uImage format:
2604 1 common/cmd_bootm.c before attempting to boot an image
2605 -1 common/cmd_bootm.c Image header has bad magic number
2606 2 common/cmd_bootm.c Image header has correct magic number
2607 -2 common/cmd_bootm.c Image header has bad checksum
2608 3 common/cmd_bootm.c Image header has correct checksum
2609 -3 common/cmd_bootm.c Image data has bad checksum
2610 4 common/cmd_bootm.c Image data has correct checksum
2611 -4 common/cmd_bootm.c Image is for unsupported architecture
2612 5 common/cmd_bootm.c Architecture check OK
2613 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2614 6 common/cmd_bootm.c Image Type check OK
2615 -6 common/cmd_bootm.c gunzip uncompression error
2616 -7 common/cmd_bootm.c Unimplemented compression type
2617 7 common/cmd_bootm.c Uncompression OK
2618 8 common/cmd_bootm.c No uncompress/copy overwrite error
2619 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2621 9 common/image.c Start initial ramdisk verification
2622 -10 common/image.c Ramdisk header has bad magic number
2623 -11 common/image.c Ramdisk header has bad checksum
2624 10 common/image.c Ramdisk header is OK
2625 -12 common/image.c Ramdisk data has bad checksum
2626 11 common/image.c Ramdisk data has correct checksum
2627 12 common/image.c Ramdisk verification complete, start loading
2628 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2629 13 common/image.c Start multifile image verification
2630 14 common/image.c No initial ramdisk, no multifile, continue.
2632 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2634 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2635 -31 post/post.c POST test failed, detected by post_output_backlog()
2636 -32 post/post.c POST test failed, detected by post_run_single()
2638 34 common/cmd_doc.c before loading a Image from a DOC device
2639 -35 common/cmd_doc.c Bad usage of "doc" command
2640 35 common/cmd_doc.c correct usage of "doc" command
2641 -36 common/cmd_doc.c No boot device
2642 36 common/cmd_doc.c correct boot device
2643 -37 common/cmd_doc.c Unknown Chip ID on boot device
2644 37 common/cmd_doc.c correct chip ID found, device available
2645 -38 common/cmd_doc.c Read Error on boot device
2646 38 common/cmd_doc.c reading Image header from DOC device OK
2647 -39 common/cmd_doc.c Image header has bad magic number
2648 39 common/cmd_doc.c Image header has correct magic number
2649 -40 common/cmd_doc.c Error reading Image from DOC device
2650 40 common/cmd_doc.c Image header has correct magic number
2651 41 common/cmd_ide.c before loading a Image from a IDE device
2652 -42 common/cmd_ide.c Bad usage of "ide" command
2653 42 common/cmd_ide.c correct usage of "ide" command
2654 -43 common/cmd_ide.c No boot device
2655 43 common/cmd_ide.c boot device found
2656 -44 common/cmd_ide.c Device not available
2657 44 common/cmd_ide.c Device available
2658 -45 common/cmd_ide.c wrong partition selected
2659 45 common/cmd_ide.c partition selected
2660 -46 common/cmd_ide.c Unknown partition table
2661 46 common/cmd_ide.c valid partition table found
2662 -47 common/cmd_ide.c Invalid partition type
2663 47 common/cmd_ide.c correct partition type
2664 -48 common/cmd_ide.c Error reading Image Header on boot device
2665 48 common/cmd_ide.c reading Image Header from IDE device OK
2666 -49 common/cmd_ide.c Image header has bad magic number
2667 49 common/cmd_ide.c Image header has correct magic number
2668 -50 common/cmd_ide.c Image header has bad checksum
2669 50 common/cmd_ide.c Image header has correct checksum
2670 -51 common/cmd_ide.c Error reading Image from IDE device
2671 51 common/cmd_ide.c reading Image from IDE device OK
2672 52 common/cmd_nand.c before loading a Image from a NAND device
2673 -53 common/cmd_nand.c Bad usage of "nand" command
2674 53 common/cmd_nand.c correct usage of "nand" command
2675 -54 common/cmd_nand.c No boot device
2676 54 common/cmd_nand.c boot device found
2677 -55 common/cmd_nand.c Unknown Chip ID on boot device
2678 55 common/cmd_nand.c correct chip ID found, device available
2679 -56 common/cmd_nand.c Error reading Image Header on boot device
2680 56 common/cmd_nand.c reading Image Header from NAND device OK
2681 -57 common/cmd_nand.c Image header has bad magic number
2682 57 common/cmd_nand.c Image header has correct magic number
2683 -58 common/cmd_nand.c Error reading Image from NAND device
2684 58 common/cmd_nand.c reading Image from NAND device OK
2686 -60 common/env_common.c Environment has a bad CRC, using default
2688 64 net/eth.c starting with Ethernet configuration.
2689 -64 net/eth.c no Ethernet found.
2690 65 net/eth.c Ethernet found.
2692 -80 common/cmd_net.c usage wrong
2693 80 common/cmd_net.c before calling net_loop()
2694 -81 common/cmd_net.c some error in net_loop() occurred
2695 81 common/cmd_net.c net_loop() back without error
2696 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2697 82 common/cmd_net.c trying automatic boot
2698 83 common/cmd_net.c running "source" command
2699 -83 common/cmd_net.c some error in automatic boot or "source" command
2700 84 common/cmd_net.c end without errors
2705 100 common/cmd_bootm.c Kernel FIT Image has correct format
2706 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2707 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2708 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2709 102 common/cmd_bootm.c Kernel unit name specified
2710 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2711 103 common/cmd_bootm.c Found configuration node
2712 104 common/cmd_bootm.c Got kernel subimage node offset
2713 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2714 105 common/cmd_bootm.c Kernel subimage hash verification OK
2715 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2716 106 common/cmd_bootm.c Architecture check OK
2717 -106 common/cmd_bootm.c Kernel subimage has wrong type
2718 107 common/cmd_bootm.c Kernel subimage type OK
2719 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2720 108 common/cmd_bootm.c Got kernel subimage data/size
2721 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2722 -109 common/cmd_bootm.c Can't get kernel subimage type
2723 -110 common/cmd_bootm.c Can't get kernel subimage comp
2724 -111 common/cmd_bootm.c Can't get kernel subimage os
2725 -112 common/cmd_bootm.c Can't get kernel subimage load address
2726 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2728 120 common/image.c Start initial ramdisk verification
2729 -120 common/image.c Ramdisk FIT image has incorrect format
2730 121 common/image.c Ramdisk FIT image has correct format
2731 122 common/image.c No ramdisk subimage unit name, using configuration
2732 -122 common/image.c Can't get configuration for ramdisk subimage
2733 123 common/image.c Ramdisk unit name specified
2734 -124 common/image.c Can't get ramdisk subimage node offset
2735 125 common/image.c Got ramdisk subimage node offset
2736 -125 common/image.c Ramdisk subimage hash verification failed
2737 126 common/image.c Ramdisk subimage hash verification OK
2738 -126 common/image.c Ramdisk subimage for unsupported architecture
2739 127 common/image.c Architecture check OK
2740 -127 common/image.c Can't get ramdisk subimage data/size
2741 128 common/image.c Got ramdisk subimage data/size
2742 129 common/image.c Can't get ramdisk load address
2743 -129 common/image.c Got ramdisk load address
2745 -130 common/cmd_doc.c Incorrect FIT image format
2746 131 common/cmd_doc.c FIT image format OK
2748 -140 common/cmd_ide.c Incorrect FIT image format
2749 141 common/cmd_ide.c FIT image format OK
2751 -150 common/cmd_nand.c Incorrect FIT image format
2752 151 common/cmd_nand.c FIT image format OK
2754 - legacy image format:
2755 CONFIG_IMAGE_FORMAT_LEGACY
2756 enables the legacy image format support in U-Boot.
2759 enabled if CONFIG_FIT_SIGNATURE is not defined.
2761 CONFIG_DISABLE_IMAGE_LEGACY
2762 disable the legacy image format
2764 This define is introduced, as the legacy image format is
2765 enabled per default for backward compatibility.
2767 - Standalone program support:
2768 CONFIG_STANDALONE_LOAD_ADDR
2770 This option defines a board specific value for the
2771 address where standalone program gets loaded, thus
2772 overwriting the architecture dependent default
2775 - Frame Buffer Address:
2778 Define CONFIG_FB_ADDR if you want to use specific
2779 address for frame buffer. This is typically the case
2780 when using a graphics controller has separate video
2781 memory. U-Boot will then place the frame buffer at
2782 the given address instead of dynamically reserving it
2783 in system RAM by calling lcd_setmem(), which grabs
2784 the memory for the frame buffer depending on the
2785 configured panel size.
2787 Please see board_init_f function.
2789 - Automatic software updates via TFTP server
2791 CONFIG_UPDATE_TFTP_CNT_MAX
2792 CONFIG_UPDATE_TFTP_MSEC_MAX
2794 These options enable and control the auto-update feature;
2795 for a more detailed description refer to doc/README.update.
2797 - MTD Support (mtdparts command, UBI support)
2800 Adds the MTD device infrastructure from the Linux kernel.
2801 Needed for mtdparts command support.
2803 CONFIG_MTD_PARTITIONS
2805 Adds the MTD partitioning infrastructure from the Linux
2806 kernel. Needed for UBI support.
2811 Adds commands for interacting with MTD partitions formatted
2812 with the UBI flash translation layer
2814 Requires also defining CONFIG_RBTREE
2816 CONFIG_UBI_SILENCE_MSG
2818 Make the verbose messages from UBI stop printing. This leaves
2819 warnings and errors enabled.
2822 CONFIG_MTD_UBI_WL_THRESHOLD
2823 This parameter defines the maximum difference between the highest
2824 erase counter value and the lowest erase counter value of eraseblocks
2825 of UBI devices. When this threshold is exceeded, UBI starts performing
2826 wear leveling by means of moving data from eraseblock with low erase
2827 counter to eraseblocks with high erase counter.
2829 The default value should be OK for SLC NAND flashes, NOR flashes and
2830 other flashes which have eraseblock life-cycle 100000 or more.
2831 However, in case of MLC NAND flashes which typically have eraseblock
2832 life-cycle less than 10000, the threshold should be lessened (e.g.,
2833 to 128 or 256, although it does not have to be power of 2).
2837 CONFIG_MTD_UBI_BEB_LIMIT
2838 This option specifies the maximum bad physical eraseblocks UBI
2839 expects on the MTD device (per 1024 eraseblocks). If the
2840 underlying flash does not admit of bad eraseblocks (e.g. NOR
2841 flash), this value is ignored.
2843 NAND datasheets often specify the minimum and maximum NVM
2844 (Number of Valid Blocks) for the flashes' endurance lifetime.
2845 The maximum expected bad eraseblocks per 1024 eraseblocks
2846 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2847 which gives 20 for most NANDs (MaxNVB is basically the total
2848 count of eraseblocks on the chip).
2850 To put it differently, if this value is 20, UBI will try to
2851 reserve about 1.9% of physical eraseblocks for bad blocks
2852 handling. And that will be 1.9% of eraseblocks on the entire
2853 NAND chip, not just the MTD partition UBI attaches. This means
2854 that if you have, say, a NAND flash chip admits maximum 40 bad
2855 eraseblocks, and it is split on two MTD partitions of the same
2856 size, UBI will reserve 40 eraseblocks when attaching a
2861 CONFIG_MTD_UBI_FASTMAP
2862 Fastmap is a mechanism which allows attaching an UBI device
2863 in nearly constant time. Instead of scanning the whole MTD device it
2864 only has to locate a checkpoint (called fastmap) on the device.
2865 The on-flash fastmap contains all information needed to attach
2866 the device. Using fastmap makes only sense on large devices where
2867 attaching by scanning takes long. UBI will not automatically install
2868 a fastmap on old images, but you can set the UBI parameter
2869 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2870 that fastmap-enabled images are still usable with UBI implementations
2871 without fastmap support. On typical flash devices the whole fastmap
2872 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2874 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2875 Set this parameter to enable fastmap automatically on images
2879 CONFIG_MTD_UBI_FM_DEBUG
2880 Enable UBI fastmap debug
2886 Adds commands for interacting with UBI volumes formatted as
2887 UBIFS. UBIFS is read-only in u-boot.
2889 Requires UBI support as well as CONFIG_LZO
2891 CONFIG_UBIFS_SILENCE_MSG
2893 Make the verbose messages from UBIFS stop printing. This leaves
2894 warnings and errors enabled.
2898 Enable building of SPL globally.
2901 LDSCRIPT for linking the SPL binary.
2903 CONFIG_SPL_MAX_FOOTPRINT
2904 Maximum size in memory allocated to the SPL, BSS included.
2905 When defined, the linker checks that the actual memory
2906 used by SPL from _start to __bss_end does not exceed it.
2907 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2908 must not be both defined at the same time.
2911 Maximum size of the SPL image (text, data, rodata, and
2912 linker lists sections), BSS excluded.
2913 When defined, the linker checks that the actual size does
2916 CONFIG_SPL_TEXT_BASE
2917 TEXT_BASE for linking the SPL binary.
2919 CONFIG_SPL_RELOC_TEXT_BASE
2920 Address to relocate to. If unspecified, this is equal to
2921 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2923 CONFIG_SPL_BSS_START_ADDR
2924 Link address for the BSS within the SPL binary.
2926 CONFIG_SPL_BSS_MAX_SIZE
2927 Maximum size in memory allocated to the SPL BSS.
2928 When defined, the linker checks that the actual memory used
2929 by SPL from __bss_start to __bss_end does not exceed it.
2930 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2931 must not be both defined at the same time.
2934 Adress of the start of the stack SPL will use
2936 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2937 When defined, SPL will panic() if the image it has
2938 loaded does not have a signature.
2939 Defining this is useful when code which loads images
2940 in SPL cannot guarantee that absolutely all read errors
2942 An example is the LPC32XX MLC NAND driver, which will
2943 consider that a completely unreadable NAND block is bad,
2944 and thus should be skipped silently.
2946 CONFIG_SPL_RELOC_STACK
2947 Adress of the start of the stack SPL will use after
2948 relocation. If unspecified, this is equal to
2951 CONFIG_SYS_SPL_MALLOC_START
2952 Starting address of the malloc pool used in SPL.
2953 When this option is set the full malloc is used in SPL and
2954 it is set up by spl_init() and before that, the simple malloc()
2955 can be used if CONFIG_SYS_MALLOC_F is defined.
2957 CONFIG_SYS_SPL_MALLOC_SIZE
2958 The size of the malloc pool used in SPL.
2960 CONFIG_SPL_FRAMEWORK
2961 Enable the SPL framework under common/. This framework
2962 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2963 NAND loading of the Linux Kernel.
2966 Enable booting directly to an OS from SPL.
2967 See also: doc/README.falcon
2969 CONFIG_SPL_DISPLAY_PRINT
2970 For ARM, enable an optional function to print more information
2971 about the running system.
2973 CONFIG_SPL_INIT_MINIMAL
2974 Arch init code should be built for a very small image
2976 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2977 Partition on the MMC to load U-Boot from when the MMC is being
2980 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2981 Sector to load kernel uImage from when MMC is being
2982 used in raw mode (for Falcon mode)
2984 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2985 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2986 Sector and number of sectors to load kernel argument
2987 parameters from when MMC is being used in raw mode
2990 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2991 Partition on the MMC to load U-Boot from when the MMC is being
2994 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2995 Filename to read to load U-Boot when reading from filesystem
2997 CONFIG_SPL_FS_LOAD_KERNEL_NAME
2998 Filename to read to load kernel uImage when reading
2999 from filesystem (for Falcon mode)
3001 CONFIG_SPL_FS_LOAD_ARGS_NAME
3002 Filename to read to load kernel argument parameters
3003 when reading from filesystem (for Falcon mode)
3005 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3006 Set this for NAND SPL on PPC mpc83xx targets, so that
3007 start.S waits for the rest of the SPL to load before
3008 continuing (the hardware starts execution after just
3009 loading the first page rather than the full 4K).
3011 CONFIG_SPL_SKIP_RELOCATE
3012 Avoid SPL relocation
3014 CONFIG_SPL_NAND_BASE
3015 Include nand_base.c in the SPL. Requires
3016 CONFIG_SPL_NAND_DRIVERS.
3018 CONFIG_SPL_NAND_DRIVERS
3019 SPL uses normal NAND drivers, not minimal drivers.
3022 Include standard software ECC in the SPL
3024 CONFIG_SPL_NAND_SIMPLE
3025 Support for NAND boot using simple NAND drivers that
3026 expose the cmd_ctrl() interface.
3029 Support for a lightweight UBI (fastmap) scanner and
3032 CONFIG_SPL_NAND_RAW_ONLY
3033 Support to boot only raw u-boot.bin images. Use this only
3034 if you need to save space.
3036 CONFIG_SPL_COMMON_INIT_DDR
3037 Set for common ddr init with serial presence detect in
3040 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3041 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3042 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3043 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3044 CONFIG_SYS_NAND_ECCBYTES
3045 Defines the size and behavior of the NAND that SPL uses
3048 CONFIG_SPL_NAND_BOOT
3049 Add support NAND boot
3051 CONFIG_SYS_NAND_U_BOOT_OFFS
3052 Location in NAND to read U-Boot from
3054 CONFIG_SYS_NAND_U_BOOT_DST
3055 Location in memory to load U-Boot to
3057 CONFIG_SYS_NAND_U_BOOT_SIZE
3058 Size of image to load
3060 CONFIG_SYS_NAND_U_BOOT_START
3061 Entry point in loaded image to jump to
3063 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3064 Define this if you need to first read the OOB and then the
3065 data. This is used, for example, on davinci platforms.
3067 CONFIG_SPL_OMAP3_ID_NAND
3068 Support for an OMAP3-specific set of functions to return the
3069 ID and MFR of the first attached NAND chip, if present.
3071 CONFIG_SPL_RAM_DEVICE
3072 Support for running image already present in ram, in SPL binary
3075 Image offset to which the SPL should be padded before appending
3076 the SPL payload. By default, this is defined as
3077 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3078 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3079 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3082 Final target image containing SPL and payload. Some SPLs
3083 use an arch-specific makefile fragment instead, for
3084 example if more than one image needs to be produced.
3086 CONFIG_FIT_SPL_PRINT
3087 Printing information about a FIT image adds quite a bit of
3088 code to SPL. So this is normally disabled in SPL. Use this
3089 option to re-enable it. This will affect the output of the
3090 bootm command when booting a FIT image.
3094 Enable building of TPL globally.
3097 Image offset to which the TPL should be padded before appending
3098 the TPL payload. By default, this is defined as
3099 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3100 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3101 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3103 - Interrupt support (PPC):
3105 There are common interrupt_init() and timer_interrupt()
3106 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3107 for CPU specific initialization. interrupt_init_cpu()
3108 should set decrementer_count to appropriate value. If
3109 CPU resets decrementer automatically after interrupt
3110 (ppc4xx) it should set decrementer_count to zero.
3111 timer_interrupt() calls timer_interrupt_cpu() for CPU
3112 specific handling. If board has watchdog / status_led
3113 / other_activity_monitor it works automatically from
3114 general timer_interrupt().
3117 Board initialization settings:
3118 ------------------------------
3120 During Initialization u-boot calls a number of board specific functions
3121 to allow the preparation of board specific prerequisites, e.g. pin setup
3122 before drivers are initialized. To enable these callbacks the
3123 following configuration macros have to be defined. Currently this is
3124 architecture specific, so please check arch/your_architecture/lib/board.c
3125 typically in board_init_f() and board_init_r().
3127 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3128 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3129 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3130 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3132 Configuration Settings:
3133 -----------------------
3135 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3136 Optionally it can be defined to support 64-bit memory commands.
3138 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3139 undefine this when you're short of memory.
3141 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3142 width of the commands listed in the 'help' command output.
3144 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3145 prompt for user input.
3147 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3149 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3151 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3153 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3154 the application (usually a Linux kernel) when it is
3157 - CONFIG_SYS_BAUDRATE_TABLE:
3158 List of legal baudrate settings for this board.
3160 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3161 Begin and End addresses of the area used by the
3164 - CONFIG_SYS_ALT_MEMTEST:
3165 Enable an alternate, more extensive memory test.
3167 - CONFIG_SYS_MEMTEST_SCRATCH:
3168 Scratch address used by the alternate memory test
3169 You only need to set this if address zero isn't writeable
3171 - CONFIG_SYS_MEM_RESERVE_SECURE
3172 Only implemented for ARMv8 for now.
3173 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3174 is substracted from total RAM and won't be reported to OS.
3175 This memory can be used as secure memory. A variable
3176 gd->arch.secure_ram is used to track the location. In systems
3177 the RAM base is not zero, or RAM is divided into banks,
3178 this variable needs to be recalcuated to get the address.
3180 - CONFIG_SYS_MEM_TOP_HIDE:
3181 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3182 this specified memory area will get subtracted from the top
3183 (end) of RAM and won't get "touched" at all by U-Boot. By
3184 fixing up gd->ram_size the Linux kernel should gets passed
3185 the now "corrected" memory size and won't touch it either.
3186 This should work for arch/ppc and arch/powerpc. Only Linux
3187 board ports in arch/powerpc with bootwrapper support that
3188 recalculate the memory size from the SDRAM controller setup
3189 will have to get fixed in Linux additionally.
3191 This option can be used as a workaround for the 440EPx/GRx
3192 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3195 WARNING: Please make sure that this value is a multiple of
3196 the Linux page size (normally 4k). If this is not the case,
3197 then the end address of the Linux memory will be located at a
3198 non page size aligned address and this could cause major
3201 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3202 Enable temporary baudrate change while serial download
3204 - CONFIG_SYS_SDRAM_BASE:
3205 Physical start address of SDRAM. _Must_ be 0 here.
3207 - CONFIG_SYS_FLASH_BASE:
3208 Physical start address of Flash memory.
3210 - CONFIG_SYS_MONITOR_BASE:
3211 Physical start address of boot monitor code (set by
3212 make config files to be same as the text base address
3213 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3214 CONFIG_SYS_FLASH_BASE when booting from flash.
3216 - CONFIG_SYS_MONITOR_LEN:
3217 Size of memory reserved for monitor code, used to
3218 determine _at_compile_time_ (!) if the environment is
3219 embedded within the U-Boot image, or in a separate
3222 - CONFIG_SYS_MALLOC_LEN:
3223 Size of DRAM reserved for malloc() use.
3225 - CONFIG_SYS_MALLOC_F_LEN
3226 Size of the malloc() pool for use before relocation. If
3227 this is defined, then a very simple malloc() implementation
3228 will become available before relocation. The address is just
3229 below the global data, and the stack is moved down to make
3232 This feature allocates regions with increasing addresses
3233 within the region. calloc() is supported, but realloc()
3234 is not available. free() is supported but does nothing.
3235 The memory will be freed (or in fact just forgotten) when
3236 U-Boot relocates itself.
3238 - CONFIG_SYS_MALLOC_SIMPLE
3239 Provides a simple and small malloc() and calloc() for those
3240 boards which do not use the full malloc in SPL (which is
3241 enabled with CONFIG_SYS_SPL_MALLOC_START).
3243 - CONFIG_SYS_NONCACHED_MEMORY:
3244 Size of non-cached memory area. This area of memory will be
3245 typically located right below the malloc() area and mapped
3246 uncached in the MMU. This is useful for drivers that would
3247 otherwise require a lot of explicit cache maintenance. For
3248 some drivers it's also impossible to properly maintain the
3249 cache. For example if the regions that need to be flushed
3250 are not a multiple of the cache-line size, *and* padding
3251 cannot be allocated between the regions to align them (i.e.
3252 if the HW requires a contiguous array of regions, and the
3253 size of each region is not cache-aligned), then a flush of
3254 one region may result in overwriting data that hardware has
3255 written to another region in the same cache-line. This can
3256 happen for example in network drivers where descriptors for
3257 buffers are typically smaller than the CPU cache-line (e.g.
3258 16 bytes vs. 32 or 64 bytes).
3260 Non-cached memory is only supported on 32-bit ARM at present.
3262 - CONFIG_SYS_BOOTM_LEN:
3263 Normally compressed uImages are limited to an
3264 uncompressed size of 8 MBytes. If this is not enough,
3265 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3266 to adjust this setting to your needs.
3268 - CONFIG_SYS_BOOTMAPSZ:
3269 Maximum size of memory mapped by the startup code of
3270 the Linux kernel; all data that must be processed by
3271 the Linux kernel (bd_info, boot arguments, FDT blob if
3272 used) must be put below this limit, unless "bootm_low"
3273 environment variable is defined and non-zero. In such case
3274 all data for the Linux kernel must be between "bootm_low"
3275 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3276 variable "bootm_mapsize" will override the value of
3277 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3278 then the value in "bootm_size" will be used instead.
3280 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3281 Enable initrd_high functionality. If defined then the
3282 initrd_high feature is enabled and the bootm ramdisk subcommand
3285 - CONFIG_SYS_BOOT_GET_CMDLINE:
3286 Enables allocating and saving kernel cmdline in space between
3287 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3289 - CONFIG_SYS_BOOT_GET_KBD:
3290 Enables allocating and saving a kernel copy of the bd_info in
3291 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3293 - CONFIG_SYS_MAX_FLASH_BANKS:
3294 Max number of Flash memory banks
3296 - CONFIG_SYS_MAX_FLASH_SECT:
3297 Max number of sectors on a Flash chip
3299 - CONFIG_SYS_FLASH_ERASE_TOUT:
3300 Timeout for Flash erase operations (in ms)
3302 - CONFIG_SYS_FLASH_WRITE_TOUT:
3303 Timeout for Flash write operations (in ms)
3305 - CONFIG_SYS_FLASH_LOCK_TOUT
3306 Timeout for Flash set sector lock bit operation (in ms)
3308 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3309 Timeout for Flash clear lock bits operation (in ms)
3311 - CONFIG_SYS_FLASH_PROTECTION
3312 If defined, hardware flash sectors protection is used
3313 instead of U-Boot software protection.
3315 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3317 Enable TFTP transfers directly to flash memory;
3318 without this option such a download has to be
3319 performed in two steps: (1) download to RAM, and (2)
3320 copy from RAM to flash.
3322 The two-step approach is usually more reliable, since
3323 you can check if the download worked before you erase
3324 the flash, but in some situations (when system RAM is
3325 too limited to allow for a temporary copy of the
3326 downloaded image) this option may be very useful.
3328 - CONFIG_SYS_FLASH_CFI:
3329 Define if the flash driver uses extra elements in the
3330 common flash structure for storing flash geometry.
3332 - CONFIG_FLASH_CFI_DRIVER
3333 This option also enables the building of the cfi_flash driver
3334 in the drivers directory
3336 - CONFIG_FLASH_CFI_MTD
3337 This option enables the building of the cfi_mtd driver
3338 in the drivers directory. The driver exports CFI flash
3341 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3342 Use buffered writes to flash.
3344 - CONFIG_FLASH_SPANSION_S29WS_N
3345 s29ws-n MirrorBit flash has non-standard addresses for buffered
3348 - CONFIG_SYS_FLASH_QUIET_TEST
3349 If this option is defined, the common CFI flash doesn't
3350 print it's warning upon not recognized FLASH banks. This
3351 is useful, if some of the configured banks are only
3352 optionally available.
3354 - CONFIG_FLASH_SHOW_PROGRESS
3355 If defined (must be an integer), print out countdown
3356 digits and dots. Recommended value: 45 (9..1) for 80
3357 column displays, 15 (3..1) for 40 column displays.
3359 - CONFIG_FLASH_VERIFY
3360 If defined, the content of the flash (destination) is compared
3361 against the source after the write operation. An error message
3362 will be printed when the contents are not identical.
3363 Please note that this option is useless in nearly all cases,
3364 since such flash programming errors usually are detected earlier
3365 while unprotecting/erasing/programming. Please only enable
3366 this option if you really know what you are doing.
3368 - CONFIG_SYS_RX_ETH_BUFFER:
3369 Defines the number of Ethernet receive buffers. On some
3370 Ethernet controllers it is recommended to set this value
3371 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3372 buffers can be full shortly after enabling the interface
3373 on high Ethernet traffic.
3374 Defaults to 4 if not defined.
3376 - CONFIG_ENV_MAX_ENTRIES
3378 Maximum number of entries in the hash table that is used
3379 internally to store the environment settings. The default
3380 setting is supposed to be generous and should work in most
3381 cases. This setting can be used to tune behaviour; see
3382 lib/hashtable.c for details.
3384 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3385 - CONFIG_ENV_FLAGS_LIST_STATIC
3386 Enable validation of the values given to environment variables when
3387 calling env set. Variables can be restricted to only decimal,
3388 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3389 the variables can also be restricted to IP address or MAC address.
3391 The format of the list is:
3392 type_attribute = [s|d|x|b|i|m]
3393 access_attribute = [a|r|o|c]
3394 attributes = type_attribute[access_attribute]
3395 entry = variable_name[:attributes]
3398 The type attributes are:
3399 s - String (default)
3402 b - Boolean ([1yYtT|0nNfF])
3406 The access attributes are:
3412 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3413 Define this to a list (string) to define the ".flags"
3414 environment variable in the default or embedded environment.
3416 - CONFIG_ENV_FLAGS_LIST_STATIC
3417 Define this to a list (string) to define validation that
3418 should be done if an entry is not found in the ".flags"
3419 environment variable. To override a setting in the static
3420 list, simply add an entry for the same variable name to the
3423 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3424 regular expression. This allows multiple variables to define the same
3425 flags without explicitly listing them for each variable.
3427 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3428 If defined, don't allow the -f switch to env set override variable
3432 If stdint.h is available with your toolchain you can define this
3433 option to enable it. You can provide option 'USE_STDINT=1' when
3434 building U-Boot to enable this.
3436 The following definitions that deal with the placement and management
3437 of environment data (variable area); in general, we support the
3438 following configurations:
3440 - CONFIG_BUILD_ENVCRC:
3442 Builds up envcrc with the target environment so that external utils
3443 may easily extract it and embed it in final U-Boot images.
3445 - CONFIG_ENV_IS_IN_FLASH:
3447 Define this if the environment is in flash memory.
3449 a) The environment occupies one whole flash sector, which is
3450 "embedded" in the text segment with the U-Boot code. This
3451 happens usually with "bottom boot sector" or "top boot
3452 sector" type flash chips, which have several smaller
3453 sectors at the start or the end. For instance, such a
3454 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3455 such a case you would place the environment in one of the
3456 4 kB sectors - with U-Boot code before and after it. With
3457 "top boot sector" type flash chips, you would put the
3458 environment in one of the last sectors, leaving a gap
3459 between U-Boot and the environment.
3461 - CONFIG_ENV_OFFSET:
3463 Offset of environment data (variable area) to the
3464 beginning of flash memory; for instance, with bottom boot
3465 type flash chips the second sector can be used: the offset
3466 for this sector is given here.
3468 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3472 This is just another way to specify the start address of
3473 the flash sector containing the environment (instead of
3476 - CONFIG_ENV_SECT_SIZE:
3478 Size of the sector containing the environment.
3481 b) Sometimes flash chips have few, equal sized, BIG sectors.
3482 In such a case you don't want to spend a whole sector for
3487 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3488 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3489 of this flash sector for the environment. This saves
3490 memory for the RAM copy of the environment.
3492 It may also save flash memory if you decide to use this
3493 when your environment is "embedded" within U-Boot code,
3494 since then the remainder of the flash sector could be used
3495 for U-Boot code. It should be pointed out that this is
3496 STRONGLY DISCOURAGED from a robustness point of view:
3497 updating the environment in flash makes it always
3498 necessary to erase the WHOLE sector. If something goes
3499 wrong before the contents has been restored from a copy in
3500 RAM, your target system will be dead.
3502 - CONFIG_ENV_ADDR_REDUND
3503 CONFIG_ENV_SIZE_REDUND
3505 These settings describe a second storage area used to hold
3506 a redundant copy of the environment data, so that there is
3507 a valid backup copy in case there is a power failure during
3508 a "saveenv" operation.
3510 BE CAREFUL! Any changes to the flash layout, and some changes to the
3511 source code will make it necessary to adapt <board>/u-boot.lds*
3515 - CONFIG_ENV_IS_IN_NVRAM:
3517 Define this if you have some non-volatile memory device
3518 (NVRAM, battery buffered SRAM) which you want to use for the
3524 These two #defines are used to determine the memory area you
3525 want to use for environment. It is assumed that this memory
3526 can just be read and written to, without any special
3529 BE CAREFUL! The first access to the environment happens quite early
3530 in U-Boot initialization (when we try to get the setting of for the
3531 console baudrate). You *MUST* have mapped your NVRAM area then, or
3534 Please note that even with NVRAM we still use a copy of the
3535 environment in RAM: we could work on NVRAM directly, but we want to
3536 keep settings there always unmodified except somebody uses "saveenv"
3537 to save the current settings.
3540 - CONFIG_ENV_IS_IN_EEPROM:
3542 Use this if you have an EEPROM or similar serial access
3543 device and a driver for it.
3545 - CONFIG_ENV_OFFSET:
3548 These two #defines specify the offset and size of the
3549 environment area within the total memory of your EEPROM.
3551 - CONFIG_SYS_I2C_EEPROM_ADDR:
3552 If defined, specified the chip address of the EEPROM device.
3553 The default address is zero.
3555 - CONFIG_SYS_I2C_EEPROM_BUS:
3556 If defined, specified the i2c bus of the EEPROM device.
3558 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3559 If defined, the number of bits used to address bytes in a
3560 single page in the EEPROM device. A 64 byte page, for example
3561 would require six bits.
3563 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3564 If defined, the number of milliseconds to delay between
3565 page writes. The default is zero milliseconds.
3567 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3568 The length in bytes of the EEPROM memory array address. Note
3569 that this is NOT the chip address length!
3571 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3572 EEPROM chips that implement "address overflow" are ones
3573 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3574 address and the extra bits end up in the "chip address" bit
3575 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3578 Note that we consider the length of the address field to
3579 still be one byte because the extra address bits are hidden
3580 in the chip address.
3582 - CONFIG_SYS_EEPROM_SIZE:
3583 The size in bytes of the EEPROM device.
3585 - CONFIG_ENV_EEPROM_IS_ON_I2C
3586 define this, if you have I2C and SPI activated, and your
3587 EEPROM, which holds the environment, is on the I2C bus.
3589 - CONFIG_I2C_ENV_EEPROM_BUS
3590 if you have an Environment on an EEPROM reached over
3591 I2C muxes, you can define here, how to reach this
3592 EEPROM. For example:
3594 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3596 EEPROM which holds the environment, is reached over
3597 a pca9547 i2c mux with address 0x70, channel 3.
3599 - CONFIG_ENV_IS_IN_DATAFLASH:
3601 Define this if you have a DataFlash memory device which you
3602 want to use for the environment.
3604 - CONFIG_ENV_OFFSET:
3608 These three #defines specify the offset and size of the
3609 environment area within the total memory of your DataFlash placed
3610 at the specified address.
3612 - CONFIG_ENV_IS_IN_SPI_FLASH:
3614 Define this if you have a SPI Flash memory device which you
3615 want to use for the environment.
3617 - CONFIG_ENV_OFFSET:
3620 These two #defines specify the offset and size of the
3621 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
3622 aligned to an erase sector boundary.
3624 - CONFIG_ENV_SECT_SIZE:
3626 Define the SPI flash's sector size.
3628 - CONFIG_ENV_OFFSET_REDUND (optional):
3630 This setting describes a second storage area of CONFIG_ENV_SIZE
3631 size used to hold a redundant copy of the environment data, so
3632 that there is a valid backup copy in case there is a power failure
3633 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3634 aligned to an erase sector boundary.
3636 - CONFIG_ENV_SPI_BUS (optional):
3637 - CONFIG_ENV_SPI_CS (optional):
3639 Define the SPI bus and chip select. If not defined they will be 0.
3641 - CONFIG_ENV_SPI_MAX_HZ (optional):
3643 Define the SPI max work clock. If not defined then use 1MHz.
3645 - CONFIG_ENV_SPI_MODE (optional):
3647 Define the SPI work mode. If not defined then use SPI_MODE_3.
3649 - CONFIG_ENV_IS_IN_REMOTE:
3651 Define this if you have a remote memory space which you
3652 want to use for the local device's environment.
3657 These two #defines specify the address and size of the
3658 environment area within the remote memory space. The
3659 local device can get the environment from remote memory
3660 space by SRIO or PCIE links.
3662 BE CAREFUL! For some special cases, the local device can not use
3663 "saveenv" command. For example, the local device will get the
3664 environment stored in a remote NOR flash by SRIO or PCIE link,
3665 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3667 - CONFIG_ENV_IS_IN_NAND:
3669 Define this if you have a NAND device which you want to use
3670 for the environment.
3672 - CONFIG_ENV_OFFSET:
3675 These two #defines specify the offset and size of the environment
3676 area within the first NAND device. CONFIG_ENV_OFFSET must be
3677 aligned to an erase block boundary.
3679 - CONFIG_ENV_OFFSET_REDUND (optional):
3681 This setting describes a second storage area of CONFIG_ENV_SIZE
3682 size used to hold a redundant copy of the environment data, so
3683 that there is a valid backup copy in case there is a power failure
3684 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3685 aligned to an erase block boundary.
3687 - CONFIG_ENV_RANGE (optional):
3689 Specifies the length of the region in which the environment
3690 can be written. This should be a multiple of the NAND device's
3691 block size. Specifying a range with more erase blocks than
3692 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3693 the range to be avoided.
3695 - CONFIG_ENV_OFFSET_OOB (optional):
3697 Enables support for dynamically retrieving the offset of the
3698 environment from block zero's out-of-band data. The
3699 "nand env.oob" command can be used to record this offset.
3700 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3701 using CONFIG_ENV_OFFSET_OOB.
3703 - CONFIG_NAND_ENV_DST
3705 Defines address in RAM to which the nand_spl code should copy the
3706 environment. If redundant environment is used, it will be copied to
3707 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3709 - CONFIG_ENV_IS_IN_UBI:
3711 Define this if you have an UBI volume that you want to use for the
3712 environment. This has the benefit of wear-leveling the environment
3713 accesses, which is important on NAND.
3715 - CONFIG_ENV_UBI_PART:
3717 Define this to a string that is the mtd partition containing the UBI.
3719 - CONFIG_ENV_UBI_VOLUME:
3721 Define this to the name of the volume that you want to store the
3724 - CONFIG_ENV_UBI_VOLUME_REDUND:
3726 Define this to the name of another volume to store a second copy of
3727 the environment in. This will enable redundant environments in UBI.
3728 It is assumed that both volumes are in the same MTD partition.
3730 - CONFIG_UBI_SILENCE_MSG
3731 - CONFIG_UBIFS_SILENCE_MSG
3733 You will probably want to define these to avoid a really noisy system
3734 when storing the env in UBI.
3736 - CONFIG_ENV_IS_IN_FAT:
3737 Define this if you want to use the FAT file system for the environment.
3739 - FAT_ENV_INTERFACE:
3741 Define this to a string that is the name of the block device.
3743 - FAT_ENV_DEVICE_AND_PART:
3745 Define this to a string to specify the partition of the device. It can
3748 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
3749 - "D:P": device D partition P. Error occurs if device D has no
3752 - "D" or "D:": device D partition 1 if device D has partition
3753 table, or the whole device D if has no partition
3755 - "D:auto": first partition in device D with bootable flag set.
3756 If none, first valid partition in device D. If no
3757 partition table then means device D.
3761 It's a string of the FAT file name. This file use to store the
3765 This must be enabled. Otherwise it cannot save the environment file.
3767 - CONFIG_ENV_IS_IN_MMC:
3769 Define this if you have an MMC device which you want to use for the
3772 - CONFIG_SYS_MMC_ENV_DEV:
3774 Specifies which MMC device the environment is stored in.
3776 - CONFIG_SYS_MMC_ENV_PART (optional):
3778 Specifies which MMC partition the environment is stored in. If not
3779 set, defaults to partition 0, the user area. Common values might be
3780 1 (first MMC boot partition), 2 (second MMC boot partition).
3782 - CONFIG_ENV_OFFSET:
3785 These two #defines specify the offset and size of the environment
3786 area within the specified MMC device.
3788 If offset is positive (the usual case), it is treated as relative to
3789 the start of the MMC partition. If offset is negative, it is treated
3790 as relative to the end of the MMC partition. This can be useful if
3791 your board may be fitted with different MMC devices, which have
3792 different sizes for the MMC partitions, and you always want the
3793 environment placed at the very end of the partition, to leave the
3794 maximum possible space before it, to store other data.
3796 These two values are in units of bytes, but must be aligned to an
3797 MMC sector boundary.
3799 - CONFIG_ENV_OFFSET_REDUND (optional):
3801 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3802 hold a redundant copy of the environment data. This provides a
3803 valid backup copy in case the other copy is corrupted, e.g. due
3804 to a power failure during a "saveenv" operation.
3806 This value may also be positive or negative; this is handled in the
3807 same way as CONFIG_ENV_OFFSET.
3809 This value is also in units of bytes, but must also be aligned to
3810 an MMC sector boundary.
3812 - CONFIG_ENV_SIZE_REDUND (optional):
3814 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3815 set. If this value is set, it must be set to the same value as
3818 Please note that the environment is read-only until the monitor
3819 has been relocated to RAM and a RAM copy of the environment has been
3820 created; also, when using EEPROM you will have to use getenv_f()
3821 until then to read environment variables.
3823 The environment is protected by a CRC32 checksum. Before the monitor
3824 is relocated into RAM, as a result of a bad CRC you will be working
3825 with the compiled-in default environment - *silently*!!! [This is
3826 necessary, because the first environment variable we need is the
3827 "baudrate" setting for the console - if we have a bad CRC, we don't
3828 have any device yet where we could complain.]
3830 Note: once the monitor has been relocated, then it will complain if
3831 the default environment is used; a new CRC is computed as soon as you
3832 use the "saveenv" command to store a valid environment.
3834 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3835 Echo the inverted Ethernet link state to the fault LED.
3837 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3838 also needs to be defined.
3840 - CONFIG_SYS_FAULT_MII_ADDR:
3841 MII address of the PHY to check for the Ethernet link state.
3843 - CONFIG_NS16550_MIN_FUNCTIONS:
3844 Define this if you desire to only have use of the NS16550_init
3845 and NS16550_putc functions for the serial driver located at
3846 drivers/serial/ns16550.c. This option is useful for saving
3847 space for already greatly restricted images, including but not
3848 limited to NAND_SPL configurations.
3850 - CONFIG_DISPLAY_BOARDINFO
3851 Display information about the board that U-Boot is running on
3852 when U-Boot starts up. The board function checkboard() is called
3855 - CONFIG_DISPLAY_BOARDINFO_LATE
3856 Similar to the previous option, but display this information
3857 later, once stdio is running and output goes to the LCD, if
3860 - CONFIG_BOARD_SIZE_LIMIT:
3861 Maximum size of the U-Boot image. When defined, the
3862 build system checks that the actual size does not
3865 Low Level (hardware related) configuration options:
3866 ---------------------------------------------------
3868 - CONFIG_SYS_CACHELINE_SIZE:
3869 Cache Line Size of the CPU.
3871 - CONFIG_SYS_CCSRBAR_DEFAULT:
3872 Default (power-on reset) physical address of CCSR on Freescale
3875 - CONFIG_SYS_CCSRBAR:
3876 Virtual address of CCSR. On a 32-bit build, this is typically
3877 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3879 - CONFIG_SYS_CCSRBAR_PHYS:
3880 Physical address of CCSR. CCSR can be relocated to a new
3881 physical address, if desired. In this case, this macro should
3882 be set to that address. Otherwise, it should be set to the
3883 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3884 is typically relocated on 36-bit builds. It is recommended
3885 that this macro be defined via the _HIGH and _LOW macros:
3887 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3888 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3890 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3891 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3892 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3893 used in assembly code, so it must not contain typecasts or
3894 integer size suffixes (e.g. "ULL").
3896 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3897 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3898 used in assembly code, so it must not contain typecasts or
3899 integer size suffixes (e.g. "ULL").
3901 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3902 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3903 forced to a value that ensures that CCSR is not relocated.
3905 - Floppy Disk Support:
3906 CONFIG_SYS_FDC_DRIVE_NUMBER
3908 the default drive number (default value 0)
3910 CONFIG_SYS_ISA_IO_STRIDE
3912 defines the spacing between FDC chipset registers
3915 CONFIG_SYS_ISA_IO_OFFSET
3917 defines the offset of register from address. It
3918 depends on which part of the data bus is connected to
3919 the FDC chipset. (default value 0)
3921 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3922 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3925 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3926 fdc_hw_init() is called at the beginning of the FDC
3927 setup. fdc_hw_init() must be provided by the board
3928 source code. It is used to make hardware-dependent
3932 Most IDE controllers were designed to be connected with PCI
3933 interface. Only few of them were designed for AHB interface.
3934 When software is doing ATA command and data transfer to
3935 IDE devices through IDE-AHB controller, some additional
3936 registers accessing to these kind of IDE-AHB controller
3939 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3940 DO NOT CHANGE unless you know exactly what you're
3941 doing! (11-4) [82xx systems only]
3943 - CONFIG_SYS_INIT_RAM_ADDR:
3945 Start address of memory area that can be used for
3946 initial data and stack; please note that this must be
3947 writable memory that is working WITHOUT special
3948 initialization, i. e. you CANNOT use normal RAM which
3949 will become available only after programming the
3950 memory controller and running certain initialization
3953 U-Boot uses the following memory types:
3954 - PPC4xx: data cache
3956 - CONFIG_SYS_GBL_DATA_OFFSET:
3958 Offset of the initial data structure in the memory
3959 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3960 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3961 data is located at the end of the available space
3962 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3963 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3964 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3965 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3968 On the MPC824X (or other systems that use the data
3969 cache for initial memory) the address chosen for
3970 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3971 point to an otherwise UNUSED address space between
3972 the top of RAM and the start of the PCI space.
3974 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3976 - CONFIG_SYS_OR_TIMING_SDRAM:
3979 - CONFIG_SYS_MAMR_PTA:
3980 periodic timer for refresh
3982 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3983 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3984 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3985 CONFIG_SYS_BR1_PRELIM:
3986 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3988 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3989 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3990 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3991 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3993 - CONFIG_PCI_DISABLE_PCIE:
3994 Disable PCI-Express on systems where it is supported but not
3997 - CONFIG_PCI_ENUM_ONLY
3998 Only scan through and get the devices on the buses.
3999 Don't do any setup work, presumably because someone or
4000 something has already done it, and we don't need to do it
4001 a second time. Useful for platforms that are pre-booted
4002 by coreboot or similar.
4004 - CONFIG_PCI_INDIRECT_BRIDGE:
4005 Enable support for indirect PCI bridges.
4008 Chip has SRIO or not
4011 Board has SRIO 1 port available
4014 Board has SRIO 2 port available
4016 - CONFIG_SRIO_PCIE_BOOT_MASTER
4017 Board can support master function for Boot from SRIO and PCIE
4019 - CONFIG_SYS_SRIOn_MEM_VIRT:
4020 Virtual Address of SRIO port 'n' memory region
4022 - CONFIG_SYS_SRIOn_MEM_PHYS:
4023 Physical Address of SRIO port 'n' memory region
4025 - CONFIG_SYS_SRIOn_MEM_SIZE:
4026 Size of SRIO port 'n' memory region
4028 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4029 Defined to tell the NAND controller that the NAND chip is using
4031 Not all NAND drivers use this symbol.
4032 Example of drivers that use it:
4033 - drivers/mtd/nand/ndfc.c
4034 - drivers/mtd/nand/mxc_nand.c
4036 - CONFIG_SYS_NDFC_EBC0_CFG
4037 Sets the EBC0_CFG register for the NDFC. If not defined
4038 a default value will be used.
4041 Get DDR timing information from an I2C EEPROM. Common
4042 with pluggable memory modules such as SODIMMs
4045 I2C address of the SPD EEPROM
4047 - CONFIG_SYS_SPD_BUS_NUM
4048 If SPD EEPROM is on an I2C bus other than the first
4049 one, specify here. Note that the value must resolve
4050 to something your driver can deal with.
4052 - CONFIG_SYS_DDR_RAW_TIMING
4053 Get DDR timing information from other than SPD. Common with
4054 soldered DDR chips onboard without SPD. DDR raw timing
4055 parameters are extracted from datasheet and hard-coded into
4056 header files or board specific files.
4058 - CONFIG_FSL_DDR_INTERACTIVE
4059 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4061 - CONFIG_FSL_DDR_SYNC_REFRESH
4062 Enable sync of refresh for multiple controllers.
4064 - CONFIG_FSL_DDR_BIST
4065 Enable built-in memory test for Freescale DDR controllers.
4067 - CONFIG_SYS_83XX_DDR_USES_CS0
4068 Only for 83xx systems. If specified, then DDR should
4069 be configured using CS0 and CS1 instead of CS2 and CS3.
4072 Enable RMII mode for all FECs.
4073 Note that this is a global option, we can't
4074 have one FEC in standard MII mode and another in RMII mode.
4076 - CONFIG_CRC32_VERIFY
4077 Add a verify option to the crc32 command.
4080 => crc32 -v <address> <count> <crc32>
4082 Where address/count indicate a memory area
4083 and crc32 is the correct crc32 which the
4087 Add the "loopw" memory command. This only takes effect if
4088 the memory commands are activated globally (CONFIG_CMD_MEM).
4091 Add the "mdc" and "mwc" memory commands. These are cyclic
4096 This command will print 4 bytes (10,11,12,13) each 500 ms.
4098 => mwc.l 100 12345678 10
4099 This command will write 12345678 to address 100 all 10 ms.
4101 This only takes effect if the memory commands are activated
4102 globally (CONFIG_CMD_MEM).
4104 - CONFIG_SKIP_LOWLEVEL_INIT
4105 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4106 low level initializations (like setting up the memory
4107 controller) are omitted and/or U-Boot does not
4108 relocate itself into RAM.
4110 Normally this variable MUST NOT be defined. The only
4111 exception is when U-Boot is loaded (to RAM) by some
4112 other boot loader or by a debugger which performs
4113 these initializations itself.
4115 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4116 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4117 to be skipped. The normal CP15 init (such as enabling the
4118 instruction cache) is still performed.
4121 Modifies the behaviour of start.S when compiling a loader
4122 that is executed before the actual U-Boot. E.g. when
4123 compiling a NAND SPL.
4126 Modifies the behaviour of start.S when compiling a loader
4127 that is executed after the SPL and before the actual U-Boot.
4128 It is loaded by the SPL.
4130 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4131 Only for 85xx systems. If this variable is specified, the section
4132 .resetvec is not kept and the section .bootpg is placed in the
4133 previous 4k of the .text section.
4135 - CONFIG_ARCH_MAP_SYSMEM
4136 Generally U-Boot (and in particular the md command) uses
4137 effective address. It is therefore not necessary to regard
4138 U-Boot address as virtual addresses that need to be translated
4139 to physical addresses. However, sandbox requires this, since
4140 it maintains its own little RAM buffer which contains all
4141 addressable memory. This option causes some memory accesses
4142 to be mapped through map_sysmem() / unmap_sysmem().
4144 - CONFIG_X86_RESET_VECTOR
4145 If defined, the x86 reset vector code is included. This is not
4146 needed when U-Boot is running from Coreboot.
4148 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4149 Enables the RTC32K OSC on AM33xx based plattforms
4151 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4152 Option to disable subpage write in NAND driver
4153 driver that uses this:
4154 drivers/mtd/nand/davinci_nand.c
4156 Freescale QE/FMAN Firmware Support:
4157 -----------------------------------
4159 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4160 loading of "firmware", which is encoded in the QE firmware binary format.
4161 This firmware often needs to be loaded during U-Boot booting, so macros
4162 are used to identify the storage device (NOR flash, SPI, etc) and the address
4165 - CONFIG_SYS_FMAN_FW_ADDR
4166 The address in the storage device where the FMAN microcode is located. The
4167 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4170 - CONFIG_SYS_QE_FW_ADDR
4171 The address in the storage device where the QE microcode is located. The
4172 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4175 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4176 The maximum possible size of the firmware. The firmware binary format
4177 has a field that specifies the actual size of the firmware, but it
4178 might not be possible to read any part of the firmware unless some
4179 local storage is allocated to hold the entire firmware first.
4181 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4182 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4183 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4184 virtual address in NOR flash.
4186 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4187 Specifies that QE/FMAN firmware is located in NAND flash.
4188 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4190 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4191 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4192 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4194 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4195 Specifies that QE/FMAN firmware is located in the remote (master)
4196 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4197 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4198 window->master inbound window->master LAW->the ucode address in
4199 master's memory space.
4201 Freescale Layerscape Management Complex Firmware Support:
4202 ---------------------------------------------------------
4203 The Freescale Layerscape Management Complex (MC) supports the loading of
4205 This firmware often needs to be loaded during U-Boot booting, so macros
4206 are used to identify the storage device (NOR flash, SPI, etc) and the address
4209 - CONFIG_FSL_MC_ENET
4210 Enable the MC driver for Layerscape SoCs.
4212 Freescale Layerscape Debug Server Support:
4213 -------------------------------------------
4214 The Freescale Layerscape Debug Server Support supports the loading of
4215 "Debug Server firmware" and triggering SP boot-rom.
4216 This firmware often needs to be loaded during U-Boot booting.
4218 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4219 Define alignment of reserved memory MC requires
4224 In order to achieve reproducible builds, timestamps used in the U-Boot build
4225 process have to be set to a fixed value.
4227 This is done using the SOURCE_DATE_EPOCH environment variable.
4228 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4229 option for U-Boot or an environment variable in U-Boot.
4231 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4233 Building the Software:
4234 ======================
4236 Building U-Boot has been tested in several native build environments
4237 and in many different cross environments. Of course we cannot support
4238 all possibly existing versions of cross development tools in all
4239 (potentially obsolete) versions. In case of tool chain problems we
4240 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4241 which is extensively used to build and test U-Boot.
4243 If you are not using a native environment, it is assumed that you
4244 have GNU cross compiling tools available in your path. In this case,
4245 you must set the environment variable CROSS_COMPILE in your shell.
4246 Note that no changes to the Makefile or any other source files are
4247 necessary. For example using the ELDK on a 4xx CPU, please enter:
4249 $ CROSS_COMPILE=ppc_4xx-
4250 $ export CROSS_COMPILE
4252 Note: If you wish to generate Windows versions of the utilities in
4253 the tools directory you can use the MinGW toolchain
4254 (http://www.mingw.org). Set your HOST tools to the MinGW
4255 toolchain and execute 'make tools'. For example:
4257 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4259 Binaries such as tools/mkimage.exe will be created which can
4260 be executed on computers running Windows.
4262 U-Boot is intended to be simple to build. After installing the
4263 sources you must configure U-Boot for one specific board type. This
4268 where "NAME_defconfig" is the name of one of the existing configu-
4269 rations; see boards.cfg for supported names.
4271 Note: for some board special configuration names may exist; check if
4272 additional information is available from the board vendor; for
4273 instance, the TQM823L systems are available without (standard)
4274 or with LCD support. You can select such additional "features"
4275 when choosing the configuration, i. e.
4277 make TQM823L_defconfig
4278 - will configure for a plain TQM823L, i. e. no LCD support
4280 make TQM823L_LCD_defconfig
4281 - will configure for a TQM823L with U-Boot console on LCD
4286 Finally, type "make all", and you should get some working U-Boot
4287 images ready for download to / installation on your system:
4289 - "u-boot.bin" is a raw binary image
4290 - "u-boot" is an image in ELF binary format
4291 - "u-boot.srec" is in Motorola S-Record format
4293 By default the build is performed locally and the objects are saved
4294 in the source directory. One of the two methods can be used to change
4295 this behavior and build U-Boot to some external directory:
4297 1. Add O= to the make command line invocations:
4299 make O=/tmp/build distclean
4300 make O=/tmp/build NAME_defconfig
4301 make O=/tmp/build all
4303 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4305 export KBUILD_OUTPUT=/tmp/build
4310 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4314 Please be aware that the Makefiles assume you are using GNU make, so
4315 for instance on NetBSD you might need to use "gmake" instead of
4319 If the system board that you have is not listed, then you will need
4320 to port U-Boot to your hardware platform. To do this, follow these
4323 1. Create a new directory to hold your board specific code. Add any
4324 files you need. In your board directory, you will need at least
4325 the "Makefile" and a "<board>.c".
4326 2. Create a new configuration file "include/configs/<board>.h" for
4328 3. If you're porting U-Boot to a new CPU, then also create a new
4329 directory to hold your CPU specific code. Add any files you need.
4330 4. Run "make <board>_defconfig" with your new name.
4331 5. Type "make", and you should get a working "u-boot.srec" file
4332 to be installed on your target system.
4333 6. Debug and solve any problems that might arise.
4334 [Of course, this last step is much harder than it sounds.]
4337 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4338 ==============================================================
4340 If you have modified U-Boot sources (for instance added a new board
4341 or support for new devices, a new CPU, etc.) you are expected to
4342 provide feedback to the other developers. The feedback normally takes
4343 the form of a "patch", i. e. a context diff against a certain (latest
4344 official or latest in the git repository) version of U-Boot sources.
4346 But before you submit such a patch, please verify that your modifi-
4347 cation did not break existing code. At least make sure that *ALL* of
4348 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4349 just run the buildman script (tools/buildman/buildman), which will
4350 configure and build U-Boot for ALL supported system. Be warned, this
4351 will take a while. Please see the buildman README, or run 'buildman -H'
4355 See also "U-Boot Porting Guide" below.
4358 Monitor Commands - Overview:
4359 ============================
4361 go - start application at address 'addr'
4362 run - run commands in an environment variable
4363 bootm - boot application image from memory
4364 bootp - boot image via network using BootP/TFTP protocol
4365 bootz - boot zImage from memory
4366 tftpboot- boot image via network using TFTP protocol
4367 and env variables "ipaddr" and "serverip"
4368 (and eventually "gatewayip")
4369 tftpput - upload a file via network using TFTP protocol
4370 rarpboot- boot image via network using RARP/TFTP protocol
4371 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4372 loads - load S-Record file over serial line
4373 loadb - load binary file over serial line (kermit mode)
4375 mm - memory modify (auto-incrementing)
4376 nm - memory modify (constant address)
4377 mw - memory write (fill)
4379 cmp - memory compare
4380 crc32 - checksum calculation
4381 i2c - I2C sub-system
4382 sspi - SPI utility commands
4383 base - print or set address offset
4384 printenv- print environment variables
4385 setenv - set environment variables
4386 saveenv - save environment variables to persistent storage
4387 protect - enable or disable FLASH write protection
4388 erase - erase FLASH memory
4389 flinfo - print FLASH memory information
4390 nand - NAND memory operations (see doc/README.nand)
4391 bdinfo - print Board Info structure
4392 iminfo - print header information for application image
4393 coninfo - print console devices and informations
4394 ide - IDE sub-system
4395 loop - infinite loop on address range
4396 loopw - infinite write loop on address range
4397 mtest - simple RAM test
4398 icache - enable or disable instruction cache
4399 dcache - enable or disable data cache
4400 reset - Perform RESET of the CPU
4401 echo - echo args to console
4402 version - print monitor version
4403 help - print online help
4404 ? - alias for 'help'
4407 Monitor Commands - Detailed Description:
4408 ========================================
4412 For now: just type "help <command>".
4415 Environment Variables:
4416 ======================
4418 U-Boot supports user configuration using Environment Variables which
4419 can be made persistent by saving to Flash memory.
4421 Environment Variables are set using "setenv", printed using
4422 "printenv", and saved to Flash using "saveenv". Using "setenv"
4423 without a value can be used to delete a variable from the
4424 environment. As long as you don't save the environment you are
4425 working with an in-memory copy. In case the Flash area containing the
4426 environment is erased by accident, a default environment is provided.
4428 Some configuration options can be set using Environment Variables.
4430 List of environment variables (most likely not complete):
4432 baudrate - see CONFIG_BAUDRATE
4434 bootdelay - see CONFIG_BOOTDELAY
4436 bootcmd - see CONFIG_BOOTCOMMAND
4438 bootargs - Boot arguments when booting an RTOS image
4440 bootfile - Name of the image to load with TFTP
4442 bootm_low - Memory range available for image processing in the bootm
4443 command can be restricted. This variable is given as
4444 a hexadecimal number and defines lowest address allowed
4445 for use by the bootm command. See also "bootm_size"
4446 environment variable. Address defined by "bootm_low" is
4447 also the base of the initial memory mapping for the Linux
4448 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4451 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4452 This variable is given as a hexadecimal number and it
4453 defines the size of the memory region starting at base
4454 address bootm_low that is accessible by the Linux kernel
4455 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4456 as the default value if it is defined, and bootm_size is
4459 bootm_size - Memory range available for image processing in the bootm
4460 command can be restricted. This variable is given as
4461 a hexadecimal number and defines the size of the region
4462 allowed for use by the bootm command. See also "bootm_low"
4463 environment variable.
4465 updatefile - Location of the software update file on a TFTP server, used
4466 by the automatic software update feature. Please refer to
4467 documentation in doc/README.update for more details.
4469 autoload - if set to "no" (any string beginning with 'n'),
4470 "bootp" will just load perform a lookup of the
4471 configuration from the BOOTP server, but not try to
4472 load any image using TFTP
4474 autostart - if set to "yes", an image loaded using the "bootp",
4475 "rarpboot", "tftpboot" or "diskboot" commands will
4476 be automatically started (by internally calling
4479 If set to "no", a standalone image passed to the
4480 "bootm" command will be copied to the load address
4481 (and eventually uncompressed), but NOT be started.
4482 This can be used to load and uncompress arbitrary
4485 fdt_high - if set this restricts the maximum address that the
4486 flattened device tree will be copied into upon boot.
4487 For example, if you have a system with 1 GB memory
4488 at physical address 0x10000000, while Linux kernel
4489 only recognizes the first 704 MB as low memory, you
4490 may need to set fdt_high as 0x3C000000 to have the
4491 device tree blob be copied to the maximum address
4492 of the 704 MB low memory, so that Linux kernel can
4493 access it during the boot procedure.
4495 If this is set to the special value 0xFFFFFFFF then
4496 the fdt will not be copied at all on boot. For this
4497 to work it must reside in writable memory, have
4498 sufficient padding on the end of it for u-boot to
4499 add the information it needs into it, and the memory
4500 must be accessible by the kernel.
4502 fdtcontroladdr- if set this is the address of the control flattened
4503 device tree used by U-Boot when CONFIG_OF_CONTROL is
4506 i2cfast - (PPC405GP|PPC405EP only)
4507 if set to 'y' configures Linux I2C driver for fast
4508 mode (400kHZ). This environment variable is used in
4509 initialization code. So, for changes to be effective
4510 it must be saved and board must be reset.
4512 initrd_high - restrict positioning of initrd images:
4513 If this variable is not set, initrd images will be
4514 copied to the highest possible address in RAM; this
4515 is usually what you want since it allows for
4516 maximum initrd size. If for some reason you want to
4517 make sure that the initrd image is loaded below the
4518 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4519 variable to a value of "no" or "off" or "0".
4520 Alternatively, you can set it to a maximum upper
4521 address to use (U-Boot will still check that it
4522 does not overwrite the U-Boot stack and data).
4524 For instance, when you have a system with 16 MB
4525 RAM, and want to reserve 4 MB from use by Linux,
4526 you can do this by adding "mem=12M" to the value of
4527 the "bootargs" variable. However, now you must make
4528 sure that the initrd image is placed in the first
4529 12 MB as well - this can be done with
4531 setenv initrd_high 00c00000
4533 If you set initrd_high to 0xFFFFFFFF, this is an
4534 indication to U-Boot that all addresses are legal
4535 for the Linux kernel, including addresses in flash
4536 memory. In this case U-Boot will NOT COPY the
4537 ramdisk at all. This may be useful to reduce the
4538 boot time on your system, but requires that this
4539 feature is supported by your Linux kernel.
4541 ipaddr - IP address; needed for tftpboot command
4543 loadaddr - Default load address for commands like "bootp",
4544 "rarpboot", "tftpboot", "loadb" or "diskboot"
4546 loads_echo - see CONFIG_LOADS_ECHO
4548 serverip - TFTP server IP address; needed for tftpboot command
4550 bootretry - see CONFIG_BOOT_RETRY_TIME
4552 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4554 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4556 ethprime - controls which interface is used first.
4558 ethact - controls which interface is currently active.
4559 For example you can do the following
4561 => setenv ethact FEC
4562 => ping 192.168.0.1 # traffic sent on FEC
4563 => setenv ethact SCC
4564 => ping 10.0.0.1 # traffic sent on SCC
4566 ethrotate - When set to "no" U-Boot does not go through all
4567 available network interfaces.
4568 It just stays at the currently selected interface.
4570 netretry - When set to "no" each network operation will
4571 either succeed or fail without retrying.
4572 When set to "once" the network operation will
4573 fail when all the available network interfaces
4574 are tried once without success.
4575 Useful on scripts which control the retry operation
4578 npe_ucode - set load address for the NPE microcode
4580 silent_linux - If set then Linux will be told to boot silently, by
4581 changing the console to be empty. If "yes" it will be
4582 made silent. If "no" it will not be made silent. If
4583 unset, then it will be made silent if the U-Boot console
4586 tftpsrcp - If this is set, the value is used for TFTP's
4589 tftpdstp - If this is set, the value is used for TFTP's UDP
4590 destination port instead of the Well Know Port 69.
4592 tftpblocksize - Block size to use for TFTP transfers; if not set,
4593 we use the TFTP server's default block size
4595 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4596 seconds, minimum value is 1000 = 1 second). Defines
4597 when a packet is considered to be lost so it has to
4598 be retransmitted. The default is 5000 = 5 seconds.
4599 Lowering this value may make downloads succeed
4600 faster in networks with high packet loss rates or
4601 with unreliable TFTP servers.
4603 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4604 unit, minimum value = 0). Defines how many timeouts
4605 can happen during a single file transfer before that
4606 transfer is aborted. The default is 10, and 0 means
4607 'no timeouts allowed'. Increasing this value may help
4608 downloads succeed with high packet loss rates, or with
4609 unreliable TFTP servers or client hardware.
4611 vlan - When set to a value < 4095 the traffic over
4612 Ethernet is encapsulated/received over 802.1q
4615 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4616 Unsigned value, in milliseconds. If not set, the period will
4617 be either the default (28000), or a value based on
4618 CONFIG_NET_RETRY_COUNT, if defined. This value has
4619 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4621 The following image location variables contain the location of images
4622 used in booting. The "Image" column gives the role of the image and is
4623 not an environment variable name. The other columns are environment
4624 variable names. "File Name" gives the name of the file on a TFTP
4625 server, "RAM Address" gives the location in RAM the image will be
4626 loaded to, and "Flash Location" gives the image's address in NOR
4627 flash or offset in NAND flash.
4629 *Note* - these variables don't have to be defined for all boards, some
4630 boards currently use other variables for these purposes, and some
4631 boards use these variables for other purposes.
4633 Image File Name RAM Address Flash Location
4634 ----- --------- ----------- --------------
4635 u-boot u-boot u-boot_addr_r u-boot_addr
4636 Linux kernel bootfile kernel_addr_r kernel_addr
4637 device tree blob fdtfile fdt_addr_r fdt_addr
4638 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4640 The following environment variables may be used and automatically
4641 updated by the network boot commands ("bootp" and "rarpboot"),
4642 depending the information provided by your boot server:
4644 bootfile - see above
4645 dnsip - IP address of your Domain Name Server
4646 dnsip2 - IP address of your secondary Domain Name Server
4647 gatewayip - IP address of the Gateway (Router) to use
4648 hostname - Target hostname
4650 netmask - Subnet Mask
4651 rootpath - Pathname of the root filesystem on the NFS server
4652 serverip - see above
4655 There are two special Environment Variables:
4657 serial# - contains hardware identification information such
4658 as type string and/or serial number
4659 ethaddr - Ethernet address
4661 These variables can be set only once (usually during manufacturing of
4662 the board). U-Boot refuses to delete or overwrite these variables
4663 once they have been set once.
4666 Further special Environment Variables:
4668 ver - Contains the U-Boot version string as printed
4669 with the "version" command. This variable is
4670 readonly (see CONFIG_VERSION_VARIABLE).
4673 Please note that changes to some configuration parameters may take
4674 only effect after the next boot (yes, that's just like Windoze :-).
4677 Callback functions for environment variables:
4678 ---------------------------------------------
4680 For some environment variables, the behavior of u-boot needs to change
4681 when their values are changed. This functionality allows functions to
4682 be associated with arbitrary variables. On creation, overwrite, or
4683 deletion, the callback will provide the opportunity for some side
4684 effect to happen or for the change to be rejected.
4686 The callbacks are named and associated with a function using the
4687 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4689 These callbacks are associated with variables in one of two ways. The
4690 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4691 in the board configuration to a string that defines a list of
4692 associations. The list must be in the following format:
4694 entry = variable_name[:callback_name]
4697 If the callback name is not specified, then the callback is deleted.
4698 Spaces are also allowed anywhere in the list.
4700 Callbacks can also be associated by defining the ".callbacks" variable
4701 with the same list format above. Any association in ".callbacks" will
4702 override any association in the static list. You can define
4703 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4704 ".callbacks" environment variable in the default or embedded environment.
4706 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4707 regular expression. This allows multiple variables to be connected to
4708 the same callback without explicitly listing them all out.
4711 Command Line Parsing:
4712 =====================
4714 There are two different command line parsers available with U-Boot:
4715 the old "simple" one, and the much more powerful "hush" shell:
4717 Old, simple command line parser:
4718 --------------------------------
4720 - supports environment variables (through setenv / saveenv commands)
4721 - several commands on one line, separated by ';'
4722 - variable substitution using "... ${name} ..." syntax
4723 - special characters ('$', ';') can be escaped by prefixing with '\',
4725 setenv bootcmd bootm \${address}
4726 - You can also escape text by enclosing in single apostrophes, for example:
4727 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4732 - similar to Bourne shell, with control structures like
4733 if...then...else...fi, for...do...done; while...do...done,
4734 until...do...done, ...
4735 - supports environment ("global") variables (through setenv / saveenv
4736 commands) and local shell variables (through standard shell syntax
4737 "name=value"); only environment variables can be used with "run"
4743 (1) If a command line (or an environment variable executed by a "run"
4744 command) contains several commands separated by semicolon, and
4745 one of these commands fails, then the remaining commands will be
4748 (2) If you execute several variables with one call to run (i. e.
4749 calling run with a list of variables as arguments), any failing
4750 command will cause "run" to terminate, i. e. the remaining
4751 variables are not executed.
4753 Note for Redundant Ethernet Interfaces:
4754 =======================================
4756 Some boards come with redundant Ethernet interfaces; U-Boot supports
4757 such configurations and is capable of automatic selection of a
4758 "working" interface when needed. MAC assignment works as follows:
4760 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4761 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4762 "eth1addr" (=>eth1), "eth2addr", ...
4764 If the network interface stores some valid MAC address (for instance
4765 in SROM), this is used as default address if there is NO correspon-
4766 ding setting in the environment; if the corresponding environment
4767 variable is set, this overrides the settings in the card; that means:
4769 o If the SROM has a valid MAC address, and there is no address in the
4770 environment, the SROM's address is used.
4772 o If there is no valid address in the SROM, and a definition in the
4773 environment exists, then the value from the environment variable is
4776 o If both the SROM and the environment contain a MAC address, and
4777 both addresses are the same, this MAC address is used.
4779 o If both the SROM and the environment contain a MAC address, and the
4780 addresses differ, the value from the environment is used and a
4783 o If neither SROM nor the environment contain a MAC address, an error
4784 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4785 a random, locally-assigned MAC is used.
4787 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4788 will be programmed into hardware as part of the initialization process. This
4789 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4790 The naming convention is as follows:
4791 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4796 U-Boot is capable of booting (and performing other auxiliary operations on)
4797 images in two formats:
4799 New uImage format (FIT)
4800 -----------------------
4802 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4803 to Flattened Device Tree). It allows the use of images with multiple
4804 components (several kernels, ramdisks, etc.), with contents protected by
4805 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4811 Old image format is based on binary files which can be basically anything,
4812 preceded by a special header; see the definitions in include/image.h for
4813 details; basically, the header defines the following image properties:
4815 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4816 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4817 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4818 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4820 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4821 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4822 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4823 * Compression Type (uncompressed, gzip, bzip2)
4829 The header is marked by a special Magic Number, and both the header
4830 and the data portions of the image are secured against corruption by
4837 Although U-Boot should support any OS or standalone application
4838 easily, the main focus has always been on Linux during the design of
4841 U-Boot includes many features that so far have been part of some
4842 special "boot loader" code within the Linux kernel. Also, any
4843 "initrd" images to be used are no longer part of one big Linux image;
4844 instead, kernel and "initrd" are separate images. This implementation
4845 serves several purposes:
4847 - the same features can be used for other OS or standalone
4848 applications (for instance: using compressed images to reduce the
4849 Flash memory footprint)
4851 - it becomes much easier to port new Linux kernel versions because
4852 lots of low-level, hardware dependent stuff are done by U-Boot
4854 - the same Linux kernel image can now be used with different "initrd"
4855 images; of course this also means that different kernel images can
4856 be run with the same "initrd". This makes testing easier (you don't
4857 have to build a new "zImage.initrd" Linux image when you just
4858 change a file in your "initrd"). Also, a field-upgrade of the
4859 software is easier now.
4865 Porting Linux to U-Boot based systems:
4866 ---------------------------------------
4868 U-Boot cannot save you from doing all the necessary modifications to
4869 configure the Linux device drivers for use with your target hardware
4870 (no, we don't intend to provide a full virtual machine interface to
4873 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4875 Just make sure your machine specific header file (for instance
4876 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4877 Information structure as we define in include/asm-<arch>/u-boot.h,
4878 and make sure that your definition of IMAP_ADDR uses the same value
4879 as your U-Boot configuration in CONFIG_SYS_IMMR.
4881 Note that U-Boot now has a driver model, a unified model for drivers.
4882 If you are adding a new driver, plumb it into driver model. If there
4883 is no uclass available, you are encouraged to create one. See
4887 Configuring the Linux kernel:
4888 -----------------------------
4890 No specific requirements for U-Boot. Make sure you have some root
4891 device (initial ramdisk, NFS) for your target system.
4894 Building a Linux Image:
4895 -----------------------
4897 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4898 not used. If you use recent kernel source, a new build target
4899 "uImage" will exist which automatically builds an image usable by
4900 U-Boot. Most older kernels also have support for a "pImage" target,
4901 which was introduced for our predecessor project PPCBoot and uses a
4902 100% compatible format.
4906 make TQM850L_defconfig
4911 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4912 encapsulate a compressed Linux kernel image with header information,
4913 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4915 * build a standard "vmlinux" kernel image (in ELF binary format):
4917 * convert the kernel into a raw binary image:
4919 ${CROSS_COMPILE}-objcopy -O binary \
4920 -R .note -R .comment \
4921 -S vmlinux linux.bin
4923 * compress the binary image:
4927 * package compressed binary image for U-Boot:
4929 mkimage -A ppc -O linux -T kernel -C gzip \
4930 -a 0 -e 0 -n "Linux Kernel Image" \
4931 -d linux.bin.gz uImage
4934 The "mkimage" tool can also be used to create ramdisk images for use
4935 with U-Boot, either separated from the Linux kernel image, or
4936 combined into one file. "mkimage" encapsulates the images with a 64
4937 byte header containing information about target architecture,
4938 operating system, image type, compression method, entry points, time
4939 stamp, CRC32 checksums, etc.
4941 "mkimage" can be called in two ways: to verify existing images and
4942 print the header information, or to build new images.
4944 In the first form (with "-l" option) mkimage lists the information
4945 contained in the header of an existing U-Boot image; this includes
4946 checksum verification:
4948 tools/mkimage -l image
4949 -l ==> list image header information
4951 The second form (with "-d" option) is used to build a U-Boot image
4952 from a "data file" which is used as image payload:
4954 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4955 -n name -d data_file image
4956 -A ==> set architecture to 'arch'
4957 -O ==> set operating system to 'os'
4958 -T ==> set image type to 'type'
4959 -C ==> set compression type 'comp'
4960 -a ==> set load address to 'addr' (hex)
4961 -e ==> set entry point to 'ep' (hex)
4962 -n ==> set image name to 'name'
4963 -d ==> use image data from 'datafile'
4965 Right now, all Linux kernels for PowerPC systems use the same load
4966 address (0x00000000), but the entry point address depends on the
4969 - 2.2.x kernels have the entry point at 0x0000000C,
4970 - 2.3.x and later kernels have the entry point at 0x00000000.
4972 So a typical call to build a U-Boot image would read:
4974 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4975 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4976 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4977 > examples/uImage.TQM850L
4978 Image Name: 2.4.4 kernel for TQM850L
4979 Created: Wed Jul 19 02:34:59 2000
4980 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4981 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4982 Load Address: 0x00000000
4983 Entry Point: 0x00000000
4985 To verify the contents of the image (or check for corruption):
4987 -> tools/mkimage -l examples/uImage.TQM850L
4988 Image Name: 2.4.4 kernel for TQM850L
4989 Created: Wed Jul 19 02:34:59 2000
4990 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4991 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4992 Load Address: 0x00000000
4993 Entry Point: 0x00000000
4995 NOTE: for embedded systems where boot time is critical you can trade
4996 speed for memory and install an UNCOMPRESSED image instead: this
4997 needs more space in Flash, but boots much faster since it does not
4998 need to be uncompressed:
5000 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5001 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5002 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5003 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5004 > examples/uImage.TQM850L-uncompressed
5005 Image Name: 2.4.4 kernel for TQM850L
5006 Created: Wed Jul 19 02:34:59 2000
5007 Image Type: PowerPC Linux Kernel Image (uncompressed)
5008 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5009 Load Address: 0x00000000
5010 Entry Point: 0x00000000
5013 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5014 when your kernel is intended to use an initial ramdisk:
5016 -> tools/mkimage -n 'Simple Ramdisk Image' \
5017 > -A ppc -O linux -T ramdisk -C gzip \
5018 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5019 Image Name: Simple Ramdisk Image
5020 Created: Wed Jan 12 14:01:50 2000
5021 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5022 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5023 Load Address: 0x00000000
5024 Entry Point: 0x00000000
5026 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5027 option performs the converse operation of the mkimage's second form (the "-d"
5028 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5031 tools/dumpimage -i image -T type -p position data_file
5032 -i ==> extract from the 'image' a specific 'data_file'
5033 -T ==> set image type to 'type'
5034 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5037 Installing a Linux Image:
5038 -------------------------
5040 To downloading a U-Boot image over the serial (console) interface,
5041 you must convert the image to S-Record format:
5043 objcopy -I binary -O srec examples/image examples/image.srec
5045 The 'objcopy' does not understand the information in the U-Boot
5046 image header, so the resulting S-Record file will be relative to
5047 address 0x00000000. To load it to a given address, you need to
5048 specify the target address as 'offset' parameter with the 'loads'
5051 Example: install the image to address 0x40100000 (which on the
5052 TQM8xxL is in the first Flash bank):
5054 => erase 40100000 401FFFFF
5060 ## Ready for S-Record download ...
5061 ~>examples/image.srec
5062 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5064 15989 15990 15991 15992
5065 [file transfer complete]
5067 ## Start Addr = 0x00000000
5070 You can check the success of the download using the 'iminfo' command;
5071 this includes a checksum verification so you can be sure no data
5072 corruption happened:
5076 ## Checking Image at 40100000 ...
5077 Image Name: 2.2.13 for initrd on TQM850L
5078 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5079 Data Size: 335725 Bytes = 327 kB = 0 MB
5080 Load Address: 00000000
5081 Entry Point: 0000000c
5082 Verifying Checksum ... OK
5088 The "bootm" command is used to boot an application that is stored in
5089 memory (RAM or Flash). In case of a Linux kernel image, the contents
5090 of the "bootargs" environment variable is passed to the kernel as
5091 parameters. You can check and modify this variable using the
5092 "printenv" and "setenv" commands:
5095 => printenv bootargs
5096 bootargs=root=/dev/ram
5098 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5100 => printenv bootargs
5101 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5104 ## Booting Linux kernel at 40020000 ...
5105 Image Name: 2.2.13 for NFS on TQM850L
5106 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5107 Data Size: 381681 Bytes = 372 kB = 0 MB
5108 Load Address: 00000000
5109 Entry Point: 0000000c
5110 Verifying Checksum ... OK
5111 Uncompressing Kernel Image ... OK
5112 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
5113 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5114 time_init: decrementer frequency = 187500000/60
5115 Calibrating delay loop... 49.77 BogoMIPS
5116 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5119 If you want to boot a Linux kernel with initial RAM disk, you pass
5120 the memory addresses of both the kernel and the initrd image (PPBCOOT
5121 format!) to the "bootm" command:
5123 => imi 40100000 40200000
5125 ## Checking Image at 40100000 ...
5126 Image Name: 2.2.13 for initrd on TQM850L
5127 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5128 Data Size: 335725 Bytes = 327 kB = 0 MB
5129 Load Address: 00000000
5130 Entry Point: 0000000c
5131 Verifying Checksum ... OK
5133 ## Checking Image at 40200000 ...
5134 Image Name: Simple Ramdisk Image
5135 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5136 Data Size: 566530 Bytes = 553 kB = 0 MB
5137 Load Address: 00000000
5138 Entry Point: 00000000
5139 Verifying Checksum ... OK
5141 => bootm 40100000 40200000
5142 ## Booting Linux kernel at 40100000 ...
5143 Image Name: 2.2.13 for initrd on TQM850L
5144 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5145 Data Size: 335725 Bytes = 327 kB = 0 MB
5146 Load Address: 00000000
5147 Entry Point: 0000000c
5148 Verifying Checksum ... OK
5149 Uncompressing Kernel Image ... OK
5150 ## Loading RAMDisk Image at 40200000 ...
5151 Image Name: Simple Ramdisk Image
5152 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5153 Data Size: 566530 Bytes = 553 kB = 0 MB
5154 Load Address: 00000000
5155 Entry Point: 00000000
5156 Verifying Checksum ... OK
5157 Loading Ramdisk ... OK
5158 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
5159 Boot arguments: root=/dev/ram
5160 time_init: decrementer frequency = 187500000/60
5161 Calibrating delay loop... 49.77 BogoMIPS
5163 RAMDISK: Compressed image found at block 0
5164 VFS: Mounted root (ext2 filesystem).
5168 Boot Linux and pass a flat device tree:
5171 First, U-Boot must be compiled with the appropriate defines. See the section
5172 titled "Linux Kernel Interface" above for a more in depth explanation. The
5173 following is an example of how to start a kernel and pass an updated
5179 oft=oftrees/mpc8540ads.dtb
5180 => tftp $oftaddr $oft
5181 Speed: 1000, full duplex
5183 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5184 Filename 'oftrees/mpc8540ads.dtb'.
5185 Load address: 0x300000
5188 Bytes transferred = 4106 (100a hex)
5189 => tftp $loadaddr $bootfile
5190 Speed: 1000, full duplex
5192 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5194 Load address: 0x200000
5195 Loading:############
5197 Bytes transferred = 1029407 (fb51f hex)
5202 => bootm $loadaddr - $oftaddr
5203 ## Booting image at 00200000 ...
5204 Image Name: Linux-2.6.17-dirty
5205 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5206 Data Size: 1029343 Bytes = 1005.2 kB
5207 Load Address: 00000000
5208 Entry Point: 00000000
5209 Verifying Checksum ... OK
5210 Uncompressing Kernel Image ... OK
5211 Booting using flat device tree at 0x300000
5212 Using MPC85xx ADS machine description
5213 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5217 More About U-Boot Image Types:
5218 ------------------------------
5220 U-Boot supports the following image types:
5222 "Standalone Programs" are directly runnable in the environment
5223 provided by U-Boot; it is expected that (if they behave
5224 well) you can continue to work in U-Boot after return from
5225 the Standalone Program.
5226 "OS Kernel Images" are usually images of some Embedded OS which
5227 will take over control completely. Usually these programs
5228 will install their own set of exception handlers, device
5229 drivers, set up the MMU, etc. - this means, that you cannot
5230 expect to re-enter U-Boot except by resetting the CPU.
5231 "RAMDisk Images" are more or less just data blocks, and their
5232 parameters (address, size) are passed to an OS kernel that is
5234 "Multi-File Images" contain several images, typically an OS
5235 (Linux) kernel image and one or more data images like
5236 RAMDisks. This construct is useful for instance when you want
5237 to boot over the network using BOOTP etc., where the boot
5238 server provides just a single image file, but you want to get
5239 for instance an OS kernel and a RAMDisk image.
5241 "Multi-File Images" start with a list of image sizes, each
5242 image size (in bytes) specified by an "uint32_t" in network
5243 byte order. This list is terminated by an "(uint32_t)0".
5244 Immediately after the terminating 0 follow the images, one by
5245 one, all aligned on "uint32_t" boundaries (size rounded up to
5246 a multiple of 4 bytes).
5248 "Firmware Images" are binary images containing firmware (like
5249 U-Boot or FPGA images) which usually will be programmed to
5252 "Script files" are command sequences that will be executed by
5253 U-Boot's command interpreter; this feature is especially
5254 useful when you configure U-Boot to use a real shell (hush)
5255 as command interpreter.
5257 Booting the Linux zImage:
5258 -------------------------
5260 On some platforms, it's possible to boot Linux zImage. This is done
5261 using the "bootz" command. The syntax of "bootz" command is the same
5262 as the syntax of "bootm" command.
5264 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5265 kernel with raw initrd images. The syntax is slightly different, the
5266 address of the initrd must be augmented by it's size, in the following
5267 format: "<initrd addres>:<initrd size>".
5273 One of the features of U-Boot is that you can dynamically load and
5274 run "standalone" applications, which can use some resources of
5275 U-Boot like console I/O functions or interrupt services.
5277 Two simple examples are included with the sources:
5282 'examples/hello_world.c' contains a small "Hello World" Demo
5283 application; it is automatically compiled when you build U-Boot.
5284 It's configured to run at address 0x00040004, so you can play with it
5288 ## Ready for S-Record download ...
5289 ~>examples/hello_world.srec
5290 1 2 3 4 5 6 7 8 9 10 11 ...
5291 [file transfer complete]
5293 ## Start Addr = 0x00040004
5295 => go 40004 Hello World! This is a test.
5296 ## Starting application at 0x00040004 ...
5307 Hit any key to exit ...
5309 ## Application terminated, rc = 0x0
5311 Another example, which demonstrates how to register a CPM interrupt
5312 handler with the U-Boot code, can be found in 'examples/timer.c'.
5313 Here, a CPM timer is set up to generate an interrupt every second.
5314 The interrupt service routine is trivial, just printing a '.'
5315 character, but this is just a demo program. The application can be
5316 controlled by the following keys:
5318 ? - print current values og the CPM Timer registers
5319 b - enable interrupts and start timer
5320 e - stop timer and disable interrupts
5321 q - quit application
5324 ## Ready for S-Record download ...
5325 ~>examples/timer.srec
5326 1 2 3 4 5 6 7 8 9 10 11 ...
5327 [file transfer complete]
5329 ## Start Addr = 0x00040004
5332 ## Starting application at 0x00040004 ...
5335 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5338 [q, b, e, ?] Set interval 1000000 us
5341 [q, b, e, ?] ........
5342 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5345 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5348 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5351 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5353 [q, b, e, ?] ...Stopping timer
5355 [q, b, e, ?] ## Application terminated, rc = 0x0
5361 Over time, many people have reported problems when trying to use the
5362 "minicom" terminal emulation program for serial download. I (wd)
5363 consider minicom to be broken, and recommend not to use it. Under
5364 Unix, I recommend to use C-Kermit for general purpose use (and
5365 especially for kermit binary protocol download ("loadb" command), and
5366 use "cu" for S-Record download ("loads" command). See
5367 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5368 for help with kermit.
5371 Nevertheless, if you absolutely want to use it try adding this
5372 configuration to your "File transfer protocols" section:
5374 Name Program Name U/D FullScr IO-Red. Multi
5375 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5376 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5382 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5383 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5385 Building requires a cross environment; it is known to work on
5386 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5387 need gmake since the Makefiles are not compatible with BSD make).
5388 Note that the cross-powerpc package does not install include files;
5389 attempting to build U-Boot will fail because <machine/ansi.h> is
5390 missing. This file has to be installed and patched manually:
5392 # cd /usr/pkg/cross/powerpc-netbsd/include
5394 # ln -s powerpc machine
5395 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5396 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5398 Native builds *don't* work due to incompatibilities between native
5399 and U-Boot include files.
5401 Booting assumes that (the first part of) the image booted is a
5402 stage-2 loader which in turn loads and then invokes the kernel
5403 proper. Loader sources will eventually appear in the NetBSD source
5404 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5405 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5408 Implementation Internals:
5409 =========================
5411 The following is not intended to be a complete description of every
5412 implementation detail. However, it should help to understand the
5413 inner workings of U-Boot and make it easier to port it to custom
5417 Initial Stack, Global Data:
5418 ---------------------------
5420 The implementation of U-Boot is complicated by the fact that U-Boot
5421 starts running out of ROM (flash memory), usually without access to
5422 system RAM (because the memory controller is not initialized yet).
5423 This means that we don't have writable Data or BSS segments, and BSS
5424 is not initialized as zero. To be able to get a C environment working
5425 at all, we have to allocate at least a minimal stack. Implementation
5426 options for this are defined and restricted by the CPU used: Some CPU
5427 models provide on-chip memory (like the IMMR area on MPC8xx and
5428 MPC826x processors), on others (parts of) the data cache can be
5429 locked as (mis-) used as memory, etc.
5431 Chris Hallinan posted a good summary of these issues to the
5432 U-Boot mailing list:
5434 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5435 From: "Chris Hallinan" <clh@net1plus.com>
5436 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5439 Correct me if I'm wrong, folks, but the way I understand it
5440 is this: Using DCACHE as initial RAM for Stack, etc, does not
5441 require any physical RAM backing up the cache. The cleverness
5442 is that the cache is being used as a temporary supply of
5443 necessary storage before the SDRAM controller is setup. It's
5444 beyond the scope of this list to explain the details, but you
5445 can see how this works by studying the cache architecture and
5446 operation in the architecture and processor-specific manuals.
5448 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5449 is another option for the system designer to use as an
5450 initial stack/RAM area prior to SDRAM being available. Either
5451 option should work for you. Using CS 4 should be fine if your
5452 board designers haven't used it for something that would
5453 cause you grief during the initial boot! It is frequently not
5456 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5457 with your processor/board/system design. The default value
5458 you will find in any recent u-boot distribution in
5459 walnut.h should work for you. I'd set it to a value larger
5460 than your SDRAM module. If you have a 64MB SDRAM module, set
5461 it above 400_0000. Just make sure your board has no resources
5462 that are supposed to respond to that address! That code in
5463 start.S has been around a while and should work as is when
5464 you get the config right.
5469 It is essential to remember this, since it has some impact on the C
5470 code for the initialization procedures:
5472 * Initialized global data (data segment) is read-only. Do not attempt
5475 * Do not use any uninitialized global data (or implicitly initialized
5476 as zero data - BSS segment) at all - this is undefined, initiali-
5477 zation is performed later (when relocating to RAM).
5479 * Stack space is very limited. Avoid big data buffers or things like
5482 Having only the stack as writable memory limits means we cannot use
5483 normal global data to share information between the code. But it
5484 turned out that the implementation of U-Boot can be greatly
5485 simplified by making a global data structure (gd_t) available to all
5486 functions. We could pass a pointer to this data as argument to _all_
5487 functions, but this would bloat the code. Instead we use a feature of
5488 the GCC compiler (Global Register Variables) to share the data: we
5489 place a pointer (gd) to the global data into a register which we
5490 reserve for this purpose.
5492 When choosing a register for such a purpose we are restricted by the
5493 relevant (E)ABI specifications for the current architecture, and by
5494 GCC's implementation.
5496 For PowerPC, the following registers have specific use:
5498 R2: reserved for system use
5499 R3-R4: parameter passing and return values
5500 R5-R10: parameter passing
5501 R13: small data area pointer
5505 (U-Boot also uses R12 as internal GOT pointer. r12
5506 is a volatile register so r12 needs to be reset when
5507 going back and forth between asm and C)
5509 ==> U-Boot will use R2 to hold a pointer to the global data
5511 Note: on PPC, we could use a static initializer (since the
5512 address of the global data structure is known at compile time),
5513 but it turned out that reserving a register results in somewhat
5514 smaller code - although the code savings are not that big (on
5515 average for all boards 752 bytes for the whole U-Boot image,
5516 624 text + 127 data).
5518 On ARM, the following registers are used:
5520 R0: function argument word/integer result
5521 R1-R3: function argument word
5522 R9: platform specific
5523 R10: stack limit (used only if stack checking is enabled)
5524 R11: argument (frame) pointer
5525 R12: temporary workspace
5528 R15: program counter
5530 ==> U-Boot will use R9 to hold a pointer to the global data
5532 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5534 On Nios II, the ABI is documented here:
5535 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5537 ==> U-Boot will use gp to hold a pointer to the global data
5539 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5540 to access small data sections, so gp is free.
5542 On NDS32, the following registers are used:
5544 R0-R1: argument/return
5546 R15: temporary register for assembler
5547 R16: trampoline register
5548 R28: frame pointer (FP)
5549 R29: global pointer (GP)
5550 R30: link register (LP)
5551 R31: stack pointer (SP)
5552 PC: program counter (PC)
5554 ==> U-Boot will use R10 to hold a pointer to the global data
5556 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5557 or current versions of GCC may "optimize" the code too much.
5562 U-Boot runs in system state and uses physical addresses, i.e. the
5563 MMU is not used either for address mapping nor for memory protection.
5565 The available memory is mapped to fixed addresses using the memory
5566 controller. In this process, a contiguous block is formed for each
5567 memory type (Flash, SDRAM, SRAM), even when it consists of several
5568 physical memory banks.
5570 U-Boot is installed in the first 128 kB of the first Flash bank (on
5571 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5572 booting and sizing and initializing DRAM, the code relocates itself
5573 to the upper end of DRAM. Immediately below the U-Boot code some
5574 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5575 configuration setting]. Below that, a structure with global Board
5576 Info data is placed, followed by the stack (growing downward).
5578 Additionally, some exception handler code is copied to the low 8 kB
5579 of DRAM (0x00000000 ... 0x00001FFF).
5581 So a typical memory configuration with 16 MB of DRAM could look like
5584 0x0000 0000 Exception Vector code
5587 0x0000 2000 Free for Application Use
5593 0x00FB FF20 Monitor Stack (Growing downward)
5594 0x00FB FFAC Board Info Data and permanent copy of global data
5595 0x00FC 0000 Malloc Arena
5598 0x00FE 0000 RAM Copy of Monitor Code
5599 ... eventually: LCD or video framebuffer
5600 ... eventually: pRAM (Protected RAM - unchanged by reset)
5601 0x00FF FFFF [End of RAM]
5604 System Initialization:
5605 ----------------------
5607 In the reset configuration, U-Boot starts at the reset entry point
5608 (on most PowerPC systems at address 0x00000100). Because of the reset
5609 configuration for CS0# this is a mirror of the on board Flash memory.
5610 To be able to re-map memory U-Boot then jumps to its link address.
5611 To be able to implement the initialization code in C, a (small!)
5612 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5613 which provide such a feature like), or in a locked part of the data
5614 cache. After that, U-Boot initializes the CPU core, the caches and
5617 Next, all (potentially) available memory banks are mapped using a
5618 preliminary mapping. For example, we put them on 512 MB boundaries
5619 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5620 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5621 programmed for SDRAM access. Using the temporary configuration, a
5622 simple memory test is run that determines the size of the SDRAM
5625 When there is more than one SDRAM bank, and the banks are of
5626 different size, the largest is mapped first. For equal size, the first
5627 bank (CS2#) is mapped first. The first mapping is always for address
5628 0x00000000, with any additional banks following immediately to create
5629 contiguous memory starting from 0.
5631 Then, the monitor installs itself at the upper end of the SDRAM area
5632 and allocates memory for use by malloc() and for the global Board
5633 Info data; also, the exception vector code is copied to the low RAM
5634 pages, and the final stack is set up.
5636 Only after this relocation will you have a "normal" C environment;
5637 until that you are restricted in several ways, mostly because you are
5638 running from ROM, and because the code will have to be relocated to a
5642 U-Boot Porting Guide:
5643 ----------------------
5645 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5649 int main(int argc, char *argv[])
5651 sighandler_t no_more_time;
5653 signal(SIGALRM, no_more_time);
5654 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5656 if (available_money > available_manpower) {
5657 Pay consultant to port U-Boot;
5661 Download latest U-Boot source;
5663 Subscribe to u-boot mailing list;
5666 email("Hi, I am new to U-Boot, how do I get started?");
5669 Read the README file in the top level directory;
5670 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5671 Read applicable doc/*.README;
5672 Read the source, Luke;
5673 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5676 if (available_money > toLocalCurrency ($2500))
5679 Add a lot of aggravation and time;
5681 if (a similar board exists) { /* hopefully... */
5682 cp -a board/<similar> board/<myboard>
5683 cp include/configs/<similar>.h include/configs/<myboard>.h
5685 Create your own board support subdirectory;
5686 Create your own board include/configs/<myboard>.h file;
5688 Edit new board/<myboard> files
5689 Edit new include/configs/<myboard>.h
5694 Add / modify source code;
5698 email("Hi, I am having problems...");
5700 Send patch file to the U-Boot email list;
5701 if (reasonable critiques)
5702 Incorporate improvements from email list code review;
5704 Defend code as written;
5710 void no_more_time (int sig)
5719 All contributions to U-Boot should conform to the Linux kernel
5720 coding style; see the file "Documentation/CodingStyle" and the script
5721 "scripts/Lindent" in your Linux kernel source directory.
5723 Source files originating from a different project (for example the
5724 MTD subsystem) are generally exempt from these guidelines and are not
5725 reformatted to ease subsequent migration to newer versions of those
5728 Please note that U-Boot is implemented in C (and to some small parts in
5729 Assembler); no C++ is used, so please do not use C++ style comments (//)
5732 Please also stick to the following formatting rules:
5733 - remove any trailing white space
5734 - use TAB characters for indentation and vertical alignment, not spaces
5735 - make sure NOT to use DOS '\r\n' line feeds
5736 - do not add more than 2 consecutive empty lines to source files
5737 - do not add trailing empty lines to source files
5739 Submissions which do not conform to the standards may be returned
5740 with a request to reformat the changes.
5746 Since the number of patches for U-Boot is growing, we need to
5747 establish some rules. Submissions which do not conform to these rules
5748 may be rejected, even when they contain important and valuable stuff.
5750 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5752 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5753 see http://lists.denx.de/mailman/listinfo/u-boot
5755 When you send a patch, please include the following information with
5758 * For bug fixes: a description of the bug and how your patch fixes
5759 this bug. Please try to include a way of demonstrating that the
5760 patch actually fixes something.
5762 * For new features: a description of the feature and your
5765 * A CHANGELOG entry as plaintext (separate from the patch)
5767 * For major contributions, add a MAINTAINERS file with your
5768 information and associated file and directory references.
5770 * When you add support for a new board, don't forget to add a
5771 maintainer e-mail address to the boards.cfg file, too.
5773 * If your patch adds new configuration options, don't forget to
5774 document these in the README file.
5776 * The patch itself. If you are using git (which is *strongly*
5777 recommended) you can easily generate the patch using the
5778 "git format-patch". If you then use "git send-email" to send it to
5779 the U-Boot mailing list, you will avoid most of the common problems
5780 with some other mail clients.
5782 If you cannot use git, use "diff -purN OLD NEW". If your version of
5783 diff does not support these options, then get the latest version of
5786 The current directory when running this command shall be the parent
5787 directory of the U-Boot source tree (i. e. please make sure that
5788 your patch includes sufficient directory information for the
5791 We prefer patches as plain text. MIME attachments are discouraged,
5792 and compressed attachments must not be used.
5794 * If one logical set of modifications affects or creates several
5795 files, all these changes shall be submitted in a SINGLE patch file.
5797 * Changesets that contain different, unrelated modifications shall be
5798 submitted as SEPARATE patches, one patch per changeset.
5803 * Before sending the patch, run the buildman script on your patched
5804 source tree and make sure that no errors or warnings are reported
5805 for any of the boards.
5807 * Keep your modifications to the necessary minimum: A patch
5808 containing several unrelated changes or arbitrary reformats will be
5809 returned with a request to re-formatting / split it.
5811 * If you modify existing code, make sure that your new code does not
5812 add to the memory footprint of the code ;-) Small is beautiful!
5813 When adding new features, these should compile conditionally only
5814 (using #ifdef), and the resulting code with the new feature
5815 disabled must not need more memory than the old code without your
5818 * Remember that there is a size limit of 100 kB per message on the
5819 u-boot mailing list. Bigger patches will be moderated. If they are
5820 reasonable and not too big, they will be acknowledged. But patches
5821 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob