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_SF * Read/write/erase SPI NOR flash
837 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
838 CONFIG_CMD_SOURCE "source" command Support
839 CONFIG_CMD_SPI * SPI serial bus support
840 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
841 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
842 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
843 CONFIG_CMD_TIMER * access to the system tick timer
844 CONFIG_CMD_USB * USB support
845 CONFIG_CMD_CDP * Cisco Discover Protocol support
846 CONFIG_CMD_MFSL * Microblaze FSL support
847 CONFIG_CMD_XIMG Load part of Multi Image
848 CONFIG_CMD_UUID * Generate random UUID or GUID string
850 EXAMPLE: If you want all functions except of network
851 support you can write:
853 #include "config_cmd_all.h"
854 #undef CONFIG_CMD_NET
857 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
859 Note: Don't enable the "icache" and "dcache" commands
860 (configuration option CONFIG_CMD_CACHE) unless you know
861 what you (and your U-Boot users) are doing. Data
862 cache cannot be enabled on systems like the
863 8260 (where accesses to the IMMR region must be
864 uncached), and it cannot be disabled on all other
865 systems where we (mis-) use the data cache to hold an
866 initial stack and some data.
869 XXX - this list needs to get updated!
871 - Removal of commands
872 If no commands are needed to boot, you can disable
873 CONFIG_CMDLINE to remove them. In this case, the command line
874 will not be available, and when U-Boot wants to execute the
875 boot command (on start-up) it will call board_run_command()
876 instead. This can reduce image size significantly for very
877 simple boot procedures.
879 - Regular expression support:
881 If this variable is defined, U-Boot is linked against
882 the SLRE (Super Light Regular Expression) library,
883 which adds regex support to some commands, as for
884 example "env grep" and "setexpr".
888 If this variable is defined, U-Boot will use a device tree
889 to configure its devices, instead of relying on statically
890 compiled #defines in the board file. This option is
891 experimental and only available on a few boards. The device
892 tree is available in the global data as gd->fdt_blob.
894 U-Boot needs to get its device tree from somewhere. This can
895 be done using one of the three options below:
898 If this variable is defined, U-Boot will embed a device tree
899 binary in its image. This device tree file should be in the
900 board directory and called <soc>-<board>.dts. The binary file
901 is then picked up in board_init_f() and made available through
902 the global data structure as gd->blob.
905 If this variable is defined, U-Boot will build a device tree
906 binary. It will be called u-boot.dtb. Architecture-specific
907 code will locate it at run-time. Generally this works by:
909 cat u-boot.bin u-boot.dtb >image.bin
911 and in fact, U-Boot does this for you, creating a file called
912 u-boot-dtb.bin which is useful in the common case. You can
913 still use the individual files if you need something more
917 If this variable is defined, U-Boot will use the device tree
918 provided by the board at runtime instead of embedding one with
919 the image. Only boards defining board_fdt_blob_setup() support
920 this option (see include/fdtdec.h file).
924 If this variable is defined, it enables watchdog
925 support for the SoC. There must be support in the SoC
926 specific code for a watchdog. When supported for a
927 specific SoC is available, then no further board specific
928 code should be needed to use it.
931 When using a watchdog circuitry external to the used
932 SoC, then define this variable and provide board
933 specific code for the "hw_watchdog_reset" function.
935 CONFIG_AT91_HW_WDT_TIMEOUT
936 specify the timeout in seconds. default 2 seconds.
939 CONFIG_VERSION_VARIABLE
940 If this variable is defined, an environment variable
941 named "ver" is created by U-Boot showing the U-Boot
942 version as printed by the "version" command.
943 Any change to this variable will be reverted at the
948 When CONFIG_CMD_DATE is selected, the type of the RTC
949 has to be selected, too. Define exactly one of the
952 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
953 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
954 CONFIG_RTC_MC146818 - use MC146818 RTC
955 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
956 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
957 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
958 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
959 CONFIG_RTC_DS164x - use Dallas DS164x RTC
960 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
961 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
962 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
963 CONFIG_SYS_RV3029_TCR - enable trickle charger on
966 Note that if the RTC uses I2C, then the I2C interface
967 must also be configured. See I2C Support, below.
970 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
972 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
973 chip-ngpio pairs that tell the PCA953X driver the number of
974 pins supported by a particular chip.
976 Note that if the GPIO device uses I2C, then the I2C interface
977 must also be configured. See I2C Support, below.
980 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
981 accesses and can checksum them or write a list of them out
982 to memory. See the 'iotrace' command for details. This is
983 useful for testing device drivers since it can confirm that
984 the driver behaves the same way before and after a code
985 change. Currently this is supported on sandbox and arm. To
986 add support for your architecture, add '#include <iotrace.h>'
987 to the bottom of arch/<arch>/include/asm/io.h and test.
989 Example output from the 'iotrace stats' command is below.
990 Note that if the trace buffer is exhausted, the checksum will
991 still continue to operate.
994 Start: 10000000 (buffer start address)
995 Size: 00010000 (buffer size)
996 Offset: 00000120 (current buffer offset)
997 Output: 10000120 (start + offset)
998 Count: 00000018 (number of trace records)
999 CRC32: 9526fb66 (CRC32 of all trace records)
1001 - Timestamp Support:
1003 When CONFIG_TIMESTAMP is selected, the timestamp
1004 (date and time) of an image is printed by image
1005 commands like bootm or iminfo. This option is
1006 automatically enabled when you select CONFIG_CMD_DATE .
1008 - Partition Labels (disklabels) Supported:
1009 Zero or more of the following:
1010 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1011 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1012 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1013 bootloader. Note 2TB partition limit; see
1015 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1017 If IDE or SCSI support is enabled (CONFIG_IDE or
1018 CONFIG_SCSI) you must configure support for at
1019 least one non-MTD partition type as well.
1022 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1023 board configurations files but used nowhere!
1025 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1026 be performed by calling the function
1027 ide_set_reset(int reset)
1028 which has to be defined in a board specific file
1033 Set this to enable ATAPI support.
1038 Set this to enable support for disks larger than 137GB
1039 Also look at CONFIG_SYS_64BIT_LBA.
1040 Whithout these , LBA48 support uses 32bit variables and will 'only'
1041 support disks up to 2.1TB.
1043 CONFIG_SYS_64BIT_LBA:
1044 When enabled, makes the IDE subsystem use 64bit sector addresses.
1048 At the moment only there is only support for the
1049 SYM53C8XX SCSI controller; define
1050 CONFIG_SCSI_SYM53C8XX to enable it.
1052 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1053 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1054 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1055 maximum numbers of LUNs, SCSI ID's and target
1057 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1059 The environment variable 'scsidevs' is set to the number of
1060 SCSI devices found during the last scan.
1062 - NETWORK Support (PCI):
1064 Support for Intel 8254x/8257x gigabit chips.
1067 Utility code for direct access to the SPI bus on Intel 8257x.
1068 This does not do anything useful unless you set at least one
1069 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1071 CONFIG_E1000_SPI_GENERIC
1072 Allow generic access to the SPI bus on the Intel 8257x, for
1073 example with the "sspi" command.
1076 Management command for E1000 devices. When used on devices
1077 with SPI support you can reprogram the EEPROM from U-Boot.
1080 Support for Intel 82557/82559/82559ER chips.
1081 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1082 write routine for first time initialisation.
1085 Support for Digital 2114x chips.
1086 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1087 modem chip initialisation (KS8761/QS6611).
1090 Support for National dp83815 chips.
1093 Support for National dp8382[01] gigabit chips.
1095 - NETWORK Support (other):
1097 CONFIG_DRIVER_AT91EMAC
1098 Support for AT91RM9200 EMAC.
1101 Define this to use reduced MII inteface
1103 CONFIG_DRIVER_AT91EMAC_QUIET
1104 If this defined, the driver is quiet.
1105 The driver doen't show link status messages.
1107 CONFIG_CALXEDA_XGMAC
1108 Support for the Calxeda XGMAC device
1111 Support for SMSC's LAN91C96 chips.
1113 CONFIG_LAN91C96_USE_32_BIT
1114 Define this to enable 32 bit addressing
1117 Support for SMSC's LAN91C111 chip
1119 CONFIG_SMC91111_BASE
1120 Define this to hold the physical address
1121 of the device (I/O space)
1123 CONFIG_SMC_USE_32_BIT
1124 Define this if data bus is 32 bits
1126 CONFIG_SMC_USE_IOFUNCS
1127 Define this to use i/o functions instead of macros
1128 (some hardware wont work with macros)
1130 CONFIG_DRIVER_TI_EMAC
1131 Support for davinci emac
1133 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1134 Define this if you have more then 3 PHYs.
1137 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1139 CONFIG_FTGMAC100_EGIGA
1140 Define this to use GE link update with gigabit PHY.
1141 Define this if FTGMAC100 is connected to gigabit PHY.
1142 If your system has 10/100 PHY only, it might not occur
1143 wrong behavior. Because PHY usually return timeout or
1144 useless data when polling gigabit status and gigabit
1145 control registers. This behavior won't affect the
1146 correctnessof 10/100 link speed update.
1149 Support for SMSC's LAN911x and LAN921x chips
1152 Define this to hold the physical address
1153 of the device (I/O space)
1155 CONFIG_SMC911X_32_BIT
1156 Define this if data bus is 32 bits
1158 CONFIG_SMC911X_16_BIT
1159 Define this if data bus is 16 bits. If your processor
1160 automatically converts one 32 bit word to two 16 bit
1161 words you may also try CONFIG_SMC911X_32_BIT.
1164 Support for Renesas on-chip Ethernet controller
1166 CONFIG_SH_ETHER_USE_PORT
1167 Define the number of ports to be used
1169 CONFIG_SH_ETHER_PHY_ADDR
1170 Define the ETH PHY's address
1172 CONFIG_SH_ETHER_CACHE_WRITEBACK
1173 If this option is set, the driver enables cache flush.
1177 Support for PWM module on the imx6.
1181 Support TPM devices.
1183 CONFIG_TPM_TIS_INFINEON
1184 Support for Infineon i2c bus TPM devices. Only one device
1185 per system is supported at this time.
1187 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1188 Define the burst count bytes upper limit
1191 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1193 CONFIG_TPM_ST33ZP24_I2C
1194 Support for STMicroelectronics ST33ZP24 I2C devices.
1195 Requires TPM_ST33ZP24 and I2C.
1197 CONFIG_TPM_ST33ZP24_SPI
1198 Support for STMicroelectronics ST33ZP24 SPI devices.
1199 Requires TPM_ST33ZP24 and SPI.
1201 CONFIG_TPM_ATMEL_TWI
1202 Support for Atmel TWI TPM device. Requires I2C support.
1205 Support for generic parallel port TPM devices. Only one device
1206 per system is supported at this time.
1208 CONFIG_TPM_TIS_BASE_ADDRESS
1209 Base address where the generic TPM device is mapped
1210 to. Contemporary x86 systems usually map it at
1214 Add tpm monitor functions.
1215 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1216 provides monitor access to authorized functions.
1219 Define this to enable the TPM support library which provides
1220 functional interfaces to some TPM commands.
1221 Requires support for a TPM device.
1223 CONFIG_TPM_AUTH_SESSIONS
1224 Define this to enable authorized functions in the TPM library.
1225 Requires CONFIG_TPM and CONFIG_SHA1.
1228 At the moment only the UHCI host controller is
1229 supported (PIP405, MIP405); define
1230 CONFIG_USB_UHCI to enable it.
1231 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1232 and define CONFIG_USB_STORAGE to enable the USB
1235 Supported are USB Keyboards and USB Floppy drives
1238 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1239 txfilltuning field in the EHCI controller on reset.
1241 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1242 HW module registers.
1245 Define the below if you wish to use the USB console.
1246 Once firmware is rebuilt from a serial console issue the
1247 command "setenv stdin usbtty; setenv stdout usbtty" and
1248 attach your USB cable. The Unix command "dmesg" should print
1249 it has found a new device. The environment variable usbtty
1250 can be set to gserial or cdc_acm to enable your device to
1251 appear to a USB host as a Linux gserial device or a
1252 Common Device Class Abstract Control Model serial device.
1253 If you select usbtty = gserial you should be able to enumerate
1255 # modprobe usbserial vendor=0xVendorID product=0xProductID
1256 else if using cdc_acm, simply setting the environment
1257 variable usbtty to be cdc_acm should suffice. The following
1258 might be defined in YourBoardName.h
1261 Define this to build a UDC device
1264 Define this to have a tty type of device available to
1265 talk to the UDC device
1268 Define this to enable the high speed support for usb
1269 device and usbtty. If this feature is enabled, a routine
1270 int is_usbd_high_speed(void)
1271 also needs to be defined by the driver to dynamically poll
1272 whether the enumeration has succeded at high speed or full
1275 CONFIG_SYS_CONSOLE_IS_IN_ENV
1276 Define this if you want stdin, stdout &/or stderr to
1279 If you have a USB-IF assigned VendorID then you may wish to
1280 define your own vendor specific values either in BoardName.h
1281 or directly in usbd_vendor_info.h. If you don't define
1282 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1283 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1284 should pretend to be a Linux device to it's target host.
1286 CONFIG_USBD_MANUFACTURER
1287 Define this string as the name of your company for
1288 - CONFIG_USBD_MANUFACTURER "my company"
1290 CONFIG_USBD_PRODUCT_NAME
1291 Define this string as the name of your product
1292 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1294 CONFIG_USBD_VENDORID
1295 Define this as your assigned Vendor ID from the USB
1296 Implementors Forum. This *must* be a genuine Vendor ID
1297 to avoid polluting the USB namespace.
1298 - CONFIG_USBD_VENDORID 0xFFFF
1300 CONFIG_USBD_PRODUCTID
1301 Define this as the unique Product ID
1303 - CONFIG_USBD_PRODUCTID 0xFFFF
1305 - ULPI Layer Support:
1306 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1307 the generic ULPI layer. The generic layer accesses the ULPI PHY
1308 via the platform viewport, so you need both the genric layer and
1309 the viewport enabled. Currently only Chipidea/ARC based
1310 viewport is supported.
1311 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1312 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1313 If your ULPI phy needs a different reference clock than the
1314 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1315 the appropriate value in Hz.
1318 The MMC controller on the Intel PXA is supported. To
1319 enable this define CONFIG_MMC. The MMC can be
1320 accessed from the boot prompt by mapping the device
1321 to physical memory similar to flash. Command line is
1322 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1323 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1326 Support for Renesas on-chip MMCIF controller
1328 CONFIG_SH_MMCIF_ADDR
1329 Define the base address of MMCIF registers
1332 Define the clock frequency for MMCIF
1334 CONFIG_SUPPORT_EMMC_BOOT
1335 Enable some additional features of the eMMC boot partitions.
1337 CONFIG_SUPPORT_EMMC_RPMB
1338 Enable the commands for reading, writing and programming the
1339 key for the Replay Protection Memory Block partition in eMMC.
1341 - USB Device Firmware Update (DFU) class support:
1342 CONFIG_USB_FUNCTION_DFU
1343 This enables the USB portion of the DFU USB class
1346 This enables the command "dfu" which is used to have
1347 U-Boot create a DFU class device via USB. This command
1348 requires that the "dfu_alt_info" environment variable be
1349 set and define the alt settings to expose to the host.
1352 This enables support for exposing (e)MMC devices via DFU.
1355 This enables support for exposing NAND devices via DFU.
1358 This enables support for exposing RAM via DFU.
1359 Note: DFU spec refer to non-volatile memory usage, but
1360 allow usages beyond the scope of spec - here RAM usage,
1361 one that would help mostly the developer.
1363 CONFIG_SYS_DFU_DATA_BUF_SIZE
1364 Dfu transfer uses a buffer before writing data to the
1365 raw storage device. Make the size (in bytes) of this buffer
1366 configurable. The size of this buffer is also configurable
1367 through the "dfu_bufsiz" environment variable.
1369 CONFIG_SYS_DFU_MAX_FILE_SIZE
1370 When updating files rather than the raw storage device,
1371 we use a static buffer to copy the file into and then write
1372 the buffer once we've been given the whole file. Define
1373 this to the maximum filesize (in bytes) for the buffer.
1374 Default is 4 MiB if undefined.
1376 DFU_DEFAULT_POLL_TIMEOUT
1377 Poll timeout [ms], is the timeout a device can send to the
1378 host. The host must wait for this timeout before sending
1379 a subsequent DFU_GET_STATUS request to the device.
1381 DFU_MANIFEST_POLL_TIMEOUT
1382 Poll timeout [ms], which the device sends to the host when
1383 entering dfuMANIFEST state. Host waits this timeout, before
1384 sending again an USB request to the device.
1386 - USB Device Android Fastboot support:
1387 CONFIG_USB_FUNCTION_FASTBOOT
1388 This enables the USB part of the fastboot gadget
1391 This enables the command "fastboot" which enables the Android
1392 fastboot mode for the platform's USB device. Fastboot is a USB
1393 protocol for downloading images, flashing and device control
1394 used on Android devices.
1395 See doc/README.android-fastboot for more information.
1397 CONFIG_ANDROID_BOOT_IMAGE
1398 This enables support for booting images which use the Android
1399 image format header.
1401 CONFIG_FASTBOOT_BUF_ADDR
1402 The fastboot protocol requires a large memory buffer for
1403 downloads. Define this to the starting RAM address to use for
1406 CONFIG_FASTBOOT_BUF_SIZE
1407 The fastboot protocol requires a large memory buffer for
1408 downloads. This buffer should be as large as possible for a
1409 platform. Define this to the size available RAM for fastboot.
1411 CONFIG_FASTBOOT_FLASH
1412 The fastboot protocol includes a "flash" command for writing
1413 the downloaded image to a non-volatile storage device. Define
1414 this to enable the "fastboot flash" command.
1416 CONFIG_FASTBOOT_FLASH_MMC_DEV
1417 The fastboot "flash" command requires additional information
1418 regarding the non-volatile storage device. Define this to
1419 the eMMC device that fastboot should use to store the image.
1421 CONFIG_FASTBOOT_GPT_NAME
1422 The fastboot "flash" command supports writing the downloaded
1423 image to the Protective MBR and the Primary GUID Partition
1424 Table. (Additionally, this downloaded image is post-processed
1425 to generate and write the Backup GUID Partition Table.)
1426 This occurs when the specified "partition name" on the
1427 "fastboot flash" command line matches this value.
1428 The default is "gpt" if undefined.
1430 CONFIG_FASTBOOT_MBR_NAME
1431 The fastboot "flash" command supports writing the downloaded
1433 This occurs when the "partition name" specified on the
1434 "fastboot flash" command line matches this value.
1435 If not defined the default value "mbr" is used.
1437 - Journaling Flash filesystem support:
1439 Define these for a default partition on a NAND device
1441 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1442 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1443 Define these for a default partition on a NOR device
1446 See Kconfig help for available keyboard drivers.
1450 Define this to enable a custom keyboard support.
1451 This simply calls drv_keyboard_init() which must be
1452 defined in your board-specific files. This option is deprecated
1453 and is only used by novena. For new boards, use driver model
1458 Enable the Freescale DIU video driver. Reference boards for
1459 SOCs that have a DIU should define this macro to enable DIU
1460 support, and should also define these other macros:
1465 CONFIG_VIDEO_SW_CURSOR
1466 CONFIG_VGA_AS_SINGLE_DEVICE
1468 CONFIG_VIDEO_BMP_LOGO
1470 The DIU driver will look for the 'video-mode' environment
1471 variable, and if defined, enable the DIU as a console during
1472 boot. See the documentation file doc/README.video for a
1473 description of this variable.
1475 - LCD Support: CONFIG_LCD
1477 Define this to enable LCD support (for output to LCD
1478 display); also select one of the supported displays
1479 by defining one of these:
1483 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1485 CONFIG_NEC_NL6448AC33:
1487 NEC NL6448AC33-18. Active, color, single scan.
1489 CONFIG_NEC_NL6448BC20
1491 NEC NL6448BC20-08. 6.5", 640x480.
1492 Active, color, single scan.
1494 CONFIG_NEC_NL6448BC33_54
1496 NEC NL6448BC33-54. 10.4", 640x480.
1497 Active, color, single scan.
1501 Sharp 320x240. Active, color, single scan.
1502 It isn't 16x9, and I am not sure what it is.
1504 CONFIG_SHARP_LQ64D341
1506 Sharp LQ64D341 display, 640x480.
1507 Active, color, single scan.
1511 HLD1045 display, 640x480.
1512 Active, color, single scan.
1516 Optrex CBL50840-2 NF-FW 99 22 M5
1518 Hitachi LMG6912RPFC-00T
1522 320x240. Black & white.
1524 CONFIG_LCD_ALIGNMENT
1526 Normally the LCD is page-aligned (typically 4KB). If this is
1527 defined then the LCD will be aligned to this value instead.
1528 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1529 here, since it is cheaper to change data cache settings on
1530 a per-section basis.
1535 Sometimes, for example if the display is mounted in portrait
1536 mode or even if it's mounted landscape but rotated by 180degree,
1537 we need to rotate our content of the display relative to the
1538 framebuffer, so that user can read the messages which are
1540 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1541 initialized with a given rotation from "vl_rot" out of
1542 "vidinfo_t" which is provided by the board specific code.
1543 The value for vl_rot is coded as following (matching to
1544 fbcon=rotate:<n> linux-kernel commandline):
1545 0 = no rotation respectively 0 degree
1546 1 = 90 degree rotation
1547 2 = 180 degree rotation
1548 3 = 270 degree rotation
1550 If CONFIG_LCD_ROTATION is not defined, the console will be
1551 initialized with 0degree rotation.
1555 Support drawing of RLE8-compressed bitmaps on the LCD.
1559 Enables an 'i2c edid' command which can read EDID
1560 information over I2C from an attached LCD display.
1562 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1564 If this option is set, the environment is checked for
1565 a variable "splashimage". If found, the usual display
1566 of logo, copyright and system information on the LCD
1567 is suppressed and the BMP image at the address
1568 specified in "splashimage" is loaded instead. The
1569 console is redirected to the "nulldev", too. This
1570 allows for a "silent" boot where a splash screen is
1571 loaded very quickly after power-on.
1573 CONFIG_SPLASHIMAGE_GUARD
1575 If this option is set, then U-Boot will prevent the environment
1576 variable "splashimage" from being set to a problematic address
1577 (see doc/README.displaying-bmps).
1578 This option is useful for targets where, due to alignment
1579 restrictions, an improperly aligned BMP image will cause a data
1580 abort. If you think you will not have problems with unaligned
1581 accesses (for example because your toolchain prevents them)
1582 there is no need to set this option.
1584 CONFIG_SPLASH_SCREEN_ALIGN
1586 If this option is set the splash image can be freely positioned
1587 on the screen. Environment variable "splashpos" specifies the
1588 position as "x,y". If a positive number is given it is used as
1589 number of pixel from left/top. If a negative number is given it
1590 is used as number of pixel from right/bottom. You can also
1591 specify 'm' for centering the image.
1594 setenv splashpos m,m
1595 => image at center of screen
1597 setenv splashpos 30,20
1598 => image at x = 30 and y = 20
1600 setenv splashpos -10,m
1601 => vertically centered image
1602 at x = dspWidth - bmpWidth - 9
1604 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1606 If this option is set, additionally to standard BMP
1607 images, gzipped BMP images can be displayed via the
1608 splashscreen support or the bmp command.
1610 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1612 If this option is set, 8-bit RLE compressed BMP images
1613 can be displayed via the splashscreen support or the
1616 - Compression support:
1619 Enabled by default to support gzip compressed images.
1623 If this option is set, support for bzip2 compressed
1624 images is included. If not, only uncompressed and gzip
1625 compressed images are supported.
1627 NOTE: the bzip2 algorithm requires a lot of RAM, so
1628 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1633 If this option is set, support for LZO compressed images
1639 The address of PHY on MII bus.
1641 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1643 The clock frequency of the MII bus
1647 If this option is set, support for speed/duplex
1648 detection of gigabit PHY is included.
1650 CONFIG_PHY_RESET_DELAY
1652 Some PHY like Intel LXT971A need extra delay after
1653 reset before any MII register access is possible.
1654 For such PHY, set this option to the usec delay
1655 required. (minimum 300usec for LXT971A)
1657 CONFIG_PHY_CMD_DELAY (ppc4xx)
1659 Some PHY like Intel LXT971A need extra delay after
1660 command issued before MII status register can be read
1665 Define a default value for the IP address to use for
1666 the default Ethernet interface, in case this is not
1667 determined through e.g. bootp.
1668 (Environment variable "ipaddr")
1670 - Server IP address:
1673 Defines a default value for the IP address of a TFTP
1674 server to contact when using the "tftboot" command.
1675 (Environment variable "serverip")
1677 CONFIG_KEEP_SERVERADDR
1679 Keeps the server's MAC address, in the env 'serveraddr'
1680 for passing to bootargs (like Linux's netconsole option)
1682 - Gateway IP address:
1685 Defines a default value for the IP address of the
1686 default router where packets to other networks are
1688 (Environment variable "gatewayip")
1693 Defines a default value for the subnet mask (or
1694 routing prefix) which is used to determine if an IP
1695 address belongs to the local subnet or needs to be
1696 forwarded through a router.
1697 (Environment variable "netmask")
1699 - Multicast TFTP Mode:
1702 Defines whether you want to support multicast TFTP as per
1703 rfc-2090; for example to work with atftp. Lets lots of targets
1704 tftp down the same boot image concurrently. Note: the Ethernet
1705 driver in use must provide a function: mcast() to join/leave a
1708 - BOOTP Recovery Mode:
1709 CONFIG_BOOTP_RANDOM_DELAY
1711 If you have many targets in a network that try to
1712 boot using BOOTP, you may want to avoid that all
1713 systems send out BOOTP requests at precisely the same
1714 moment (which would happen for instance at recovery
1715 from a power failure, when all systems will try to
1716 boot, thus flooding the BOOTP server. Defining
1717 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1718 inserted before sending out BOOTP requests. The
1719 following delays are inserted then:
1721 1st BOOTP request: delay 0 ... 1 sec
1722 2nd BOOTP request: delay 0 ... 2 sec
1723 3rd BOOTP request: delay 0 ... 4 sec
1725 BOOTP requests: delay 0 ... 8 sec
1727 CONFIG_BOOTP_ID_CACHE_SIZE
1729 BOOTP packets are uniquely identified using a 32-bit ID. The
1730 server will copy the ID from client requests to responses and
1731 U-Boot will use this to determine if it is the destination of
1732 an incoming response. Some servers will check that addresses
1733 aren't in use before handing them out (usually using an ARP
1734 ping) and therefore take up to a few hundred milliseconds to
1735 respond. Network congestion may also influence the time it
1736 takes for a response to make it back to the client. If that
1737 time is too long, U-Boot will retransmit requests. In order
1738 to allow earlier responses to still be accepted after these
1739 retransmissions, U-Boot's BOOTP client keeps a small cache of
1740 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1741 cache. The default is to keep IDs for up to four outstanding
1742 requests. Increasing this will allow U-Boot to accept offers
1743 from a BOOTP client in networks with unusually high latency.
1745 - DHCP Advanced Options:
1746 You can fine tune the DHCP functionality by defining
1747 CONFIG_BOOTP_* symbols:
1749 CONFIG_BOOTP_SUBNETMASK
1750 CONFIG_BOOTP_GATEWAY
1751 CONFIG_BOOTP_HOSTNAME
1752 CONFIG_BOOTP_NISDOMAIN
1753 CONFIG_BOOTP_BOOTPATH
1754 CONFIG_BOOTP_BOOTFILESIZE
1757 CONFIG_BOOTP_SEND_HOSTNAME
1758 CONFIG_BOOTP_NTPSERVER
1759 CONFIG_BOOTP_TIMEOFFSET
1760 CONFIG_BOOTP_VENDOREX
1761 CONFIG_BOOTP_MAY_FAIL
1763 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1764 environment variable, not the BOOTP server.
1766 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1767 after the configured retry count, the call will fail
1768 instead of starting over. This can be used to fail over
1769 to Link-local IP address configuration if the DHCP server
1772 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1773 serverip from a DHCP server, it is possible that more
1774 than one DNS serverip is offered to the client.
1775 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1776 serverip will be stored in the additional environment
1777 variable "dnsip2". The first DNS serverip is always
1778 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1781 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1782 to do a dynamic update of a DNS server. To do this, they
1783 need the hostname of the DHCP requester.
1784 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1785 of the "hostname" environment variable is passed as
1786 option 12 to the DHCP server.
1788 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1790 A 32bit value in microseconds for a delay between
1791 receiving a "DHCP Offer" and sending the "DHCP Request".
1792 This fixes a problem with certain DHCP servers that don't
1793 respond 100% of the time to a "DHCP request". E.g. On an
1794 AT91RM9200 processor running at 180MHz, this delay needed
1795 to be *at least* 15,000 usec before a Windows Server 2003
1796 DHCP server would reply 100% of the time. I recommend at
1797 least 50,000 usec to be safe. The alternative is to hope
1798 that one of the retries will be successful but note that
1799 the DHCP timeout and retry process takes a longer than
1802 - Link-local IP address negotiation:
1803 Negotiate with other link-local clients on the local network
1804 for an address that doesn't require explicit configuration.
1805 This is especially useful if a DHCP server cannot be guaranteed
1806 to exist in all environments that the device must operate.
1808 See doc/README.link-local for more information.
1811 CONFIG_CDP_DEVICE_ID
1813 The device id used in CDP trigger frames.
1815 CONFIG_CDP_DEVICE_ID_PREFIX
1817 A two character string which is prefixed to the MAC address
1822 A printf format string which contains the ascii name of
1823 the port. Normally is set to "eth%d" which sets
1824 eth0 for the first Ethernet, eth1 for the second etc.
1826 CONFIG_CDP_CAPABILITIES
1828 A 32bit integer which indicates the device capabilities;
1829 0x00000010 for a normal host which does not forwards.
1833 An ascii string containing the version of the software.
1837 An ascii string containing the name of the platform.
1841 A 32bit integer sent on the trigger.
1843 CONFIG_CDP_POWER_CONSUMPTION
1845 A 16bit integer containing the power consumption of the
1846 device in .1 of milliwatts.
1848 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1850 A byte containing the id of the VLAN.
1852 - Status LED: CONFIG_LED_STATUS
1854 Several configurations allow to display the current
1855 status using a LED. For instance, the LED will blink
1856 fast while running U-Boot code, stop blinking as
1857 soon as a reply to a BOOTP request was received, and
1858 start blinking slow once the Linux kernel is running
1859 (supported by a status LED driver in the Linux
1860 kernel). Defining CONFIG_LED_STATUS enables this
1865 CONFIG_LED_STATUS_GPIO
1866 The status LED can be connected to a GPIO pin.
1867 In such cases, the gpio_led driver can be used as a
1868 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1869 to include the gpio_led driver in the U-Boot binary.
1871 CONFIG_GPIO_LED_INVERTED_TABLE
1872 Some GPIO connected LEDs may have inverted polarity in which
1873 case the GPIO high value corresponds to LED off state and
1874 GPIO low value corresponds to LED on state.
1875 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1876 with a list of GPIO LEDs that have inverted polarity.
1878 - I2C Support: CONFIG_SYS_I2C
1880 This enable the NEW i2c subsystem, and will allow you to use
1881 i2c commands at the u-boot command line (as long as you set
1882 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1883 based realtime clock chips or other i2c devices. See
1884 common/cmd_i2c.c for a description of the command line
1887 ported i2c driver to the new framework:
1888 - drivers/i2c/soft_i2c.c:
1889 - activate first bus with CONFIG_SYS_I2C_SOFT define
1890 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1891 for defining speed and slave address
1892 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1893 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1894 for defining speed and slave address
1895 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1896 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1897 for defining speed and slave address
1898 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1899 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1900 for defining speed and slave address
1902 - drivers/i2c/fsl_i2c.c:
1903 - activate i2c driver with CONFIG_SYS_I2C_FSL
1904 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1905 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1906 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1908 - If your board supports a second fsl i2c bus, define
1909 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1910 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1911 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1914 - drivers/i2c/tegra_i2c.c:
1915 - activate this driver with CONFIG_SYS_I2C_TEGRA
1916 - This driver adds 4 i2c buses with a fix speed from
1917 100000 and the slave addr 0!
1919 - drivers/i2c/ppc4xx_i2c.c
1920 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1921 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1922 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1924 - drivers/i2c/i2c_mxc.c
1925 - activate this driver with CONFIG_SYS_I2C_MXC
1926 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1927 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1928 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1929 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1930 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1931 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1932 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1933 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1934 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1935 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1936 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1937 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1938 If those defines are not set, default value is 100000
1939 for speed, and 0 for slave.
1941 - drivers/i2c/rcar_i2c.c:
1942 - activate this driver with CONFIG_SYS_I2C_RCAR
1943 - This driver adds 4 i2c buses
1945 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1946 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1947 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1948 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1949 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1950 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1951 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1952 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1953 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1955 - drivers/i2c/sh_i2c.c:
1956 - activate this driver with CONFIG_SYS_I2C_SH
1957 - This driver adds from 2 to 5 i2c buses
1959 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1960 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1961 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1962 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1963 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1964 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1965 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1966 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1967 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1968 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1969 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1971 - drivers/i2c/omap24xx_i2c.c
1972 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1973 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1974 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1975 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1976 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1977 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1978 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1979 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1980 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1981 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1982 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1984 - drivers/i2c/zynq_i2c.c
1985 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1986 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1987 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1989 - drivers/i2c/s3c24x0_i2c.c:
1990 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1991 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1992 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1993 with a fix speed from 100000 and the slave addr 0!
1995 - drivers/i2c/ihs_i2c.c
1996 - activate this driver with CONFIG_SYS_I2C_IHS
1997 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1998 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1999 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2000 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2001 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2002 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2003 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2004 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2005 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2006 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2007 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2008 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2009 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2010 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2011 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2012 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2013 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2014 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2015 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2016 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2017 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2021 CONFIG_SYS_NUM_I2C_BUSES
2022 Hold the number of i2c buses you want to use.
2024 CONFIG_SYS_I2C_DIRECT_BUS
2025 define this, if you don't use i2c muxes on your hardware.
2026 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2029 CONFIG_SYS_I2C_MAX_HOPS
2030 define how many muxes are maximal consecutively connected
2031 on one i2c bus. If you not use i2c muxes, omit this
2034 CONFIG_SYS_I2C_BUSES
2035 hold a list of buses you want to use, only used if
2036 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2037 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2038 CONFIG_SYS_NUM_I2C_BUSES = 9:
2040 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2041 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2042 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2043 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2044 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2045 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2046 {1, {I2C_NULL_HOP}}, \
2047 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2048 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2052 bus 0 on adapter 0 without a mux
2053 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2054 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2055 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2056 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2057 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2058 bus 6 on adapter 1 without a mux
2059 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2060 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2062 If you do not have i2c muxes on your board, omit this define.
2064 - Legacy I2C Support:
2065 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2066 then the following macros need to be defined (examples are
2067 from include/configs/lwmon.h):
2071 (Optional). Any commands necessary to enable the I2C
2072 controller or configure ports.
2074 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2078 The code necessary to make the I2C data line active
2079 (driven). If the data line is open collector, this
2082 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2086 The code necessary to make the I2C data line tri-stated
2087 (inactive). If the data line is open collector, this
2090 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2094 Code that returns true if the I2C data line is high,
2097 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2101 If <bit> is true, sets the I2C data line high. If it
2102 is false, it clears it (low).
2104 eg: #define I2C_SDA(bit) \
2105 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2106 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2110 If <bit> is true, sets the I2C clock line high. If it
2111 is false, it clears it (low).
2113 eg: #define I2C_SCL(bit) \
2114 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2115 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2119 This delay is invoked four times per clock cycle so this
2120 controls the rate of data transfer. The data rate thus
2121 is 1 / (I2C_DELAY * 4). Often defined to be something
2124 #define I2C_DELAY udelay(2)
2126 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2128 If your arch supports the generic GPIO framework (asm/gpio.h),
2129 then you may alternatively define the two GPIOs that are to be
2130 used as SCL / SDA. Any of the previous I2C_xxx macros will
2131 have GPIO-based defaults assigned to them as appropriate.
2133 You should define these to the GPIO value as given directly to
2134 the generic GPIO functions.
2136 CONFIG_SYS_I2C_INIT_BOARD
2138 When a board is reset during an i2c bus transfer
2139 chips might think that the current transfer is still
2140 in progress. On some boards it is possible to access
2141 the i2c SCLK line directly, either by using the
2142 processor pin as a GPIO or by having a second pin
2143 connected to the bus. If this option is defined a
2144 custom i2c_init_board() routine in boards/xxx/board.c
2145 is run early in the boot sequence.
2147 CONFIG_I2C_MULTI_BUS
2149 This option allows the use of multiple I2C buses, each of which
2150 must have a controller. At any point in time, only one bus is
2151 active. To switch to a different bus, use the 'i2c dev' command.
2152 Note that bus numbering is zero-based.
2154 CONFIG_SYS_I2C_NOPROBES
2156 This option specifies a list of I2C devices that will be skipped
2157 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2158 is set, specify a list of bus-device pairs. Otherwise, specify
2159 a 1D array of device addresses
2162 #undef CONFIG_I2C_MULTI_BUS
2163 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2165 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2167 #define CONFIG_I2C_MULTI_BUS
2168 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2170 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2172 CONFIG_SYS_SPD_BUS_NUM
2174 If defined, then this indicates the I2C bus number for DDR SPD.
2175 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2177 CONFIG_SYS_RTC_BUS_NUM
2179 If defined, then this indicates the I2C bus number for the RTC.
2180 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2182 CONFIG_SOFT_I2C_READ_REPEATED_START
2184 defining this will force the i2c_read() function in
2185 the soft_i2c driver to perform an I2C repeated start
2186 between writing the address pointer and reading the
2187 data. If this define is omitted the default behaviour
2188 of doing a stop-start sequence will be used. Most I2C
2189 devices can use either method, but some require one or
2192 - SPI Support: CONFIG_SPI
2194 Enables SPI driver (so far only tested with
2195 SPI EEPROM, also an instance works with Crystal A/D and
2196 D/As on the SACSng board)
2200 Enables the driver for SPI controller on SuperH. Currently
2201 only SH7757 is supported.
2205 Enables a software (bit-bang) SPI driver rather than
2206 using hardware support. This is a general purpose
2207 driver that only requires three general I/O port pins
2208 (two outputs, one input) to function. If this is
2209 defined, the board configuration must define several
2210 SPI configuration items (port pins to use, etc). For
2211 an example, see include/configs/sacsng.h.
2215 Enables a hardware SPI driver for general-purpose reads
2216 and writes. As with CONFIG_SOFT_SPI, the board configuration
2217 must define a list of chip-select function pointers.
2218 Currently supported on some MPC8xxx processors. For an
2219 example, see include/configs/mpc8349emds.h.
2223 Enables the driver for the SPI controllers on i.MX and MXC
2224 SoCs. Currently i.MX31/35/51 are supported.
2226 CONFIG_SYS_SPI_MXC_WAIT
2227 Timeout for waiting until spi transfer completed.
2228 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2230 - FPGA Support: CONFIG_FPGA
2232 Enables FPGA subsystem.
2234 CONFIG_FPGA_<vendor>
2236 Enables support for specific chip vendors.
2239 CONFIG_FPGA_<family>
2241 Enables support for FPGA family.
2242 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2246 Specify the number of FPGA devices to support.
2248 CONFIG_SYS_FPGA_PROG_FEEDBACK
2250 Enable printing of hash marks during FPGA configuration.
2252 CONFIG_SYS_FPGA_CHECK_BUSY
2254 Enable checks on FPGA configuration interface busy
2255 status by the configuration function. This option
2256 will require a board or device specific function to
2261 If defined, a function that provides delays in the FPGA
2262 configuration driver.
2264 CONFIG_SYS_FPGA_CHECK_CTRLC
2265 Allow Control-C to interrupt FPGA configuration
2267 CONFIG_SYS_FPGA_CHECK_ERROR
2269 Check for configuration errors during FPGA bitfile
2270 loading. For example, abort during Virtex II
2271 configuration if the INIT_B line goes low (which
2272 indicated a CRC error).
2274 CONFIG_SYS_FPGA_WAIT_INIT
2276 Maximum time to wait for the INIT_B line to de-assert
2277 after PROB_B has been de-asserted during a Virtex II
2278 FPGA configuration sequence. The default time is 500
2281 CONFIG_SYS_FPGA_WAIT_BUSY
2283 Maximum time to wait for BUSY to de-assert during
2284 Virtex II FPGA configuration. The default is 5 ms.
2286 CONFIG_SYS_FPGA_WAIT_CONFIG
2288 Time to wait after FPGA configuration. The default is
2291 - Configuration Management:
2294 Some SoCs need special image types (e.g. U-Boot binary
2295 with a special header) as build targets. By defining
2296 CONFIG_BUILD_TARGET in the SoC / board header, this
2297 special image will be automatically built upon calling
2302 If defined, this string will be added to the U-Boot
2303 version information (U_BOOT_VERSION)
2305 - Vendor Parameter Protection:
2307 U-Boot considers the values of the environment
2308 variables "serial#" (Board Serial Number) and
2309 "ethaddr" (Ethernet Address) to be parameters that
2310 are set once by the board vendor / manufacturer, and
2311 protects these variables from casual modification by
2312 the user. Once set, these variables are read-only,
2313 and write or delete attempts are rejected. You can
2314 change this behaviour:
2316 If CONFIG_ENV_OVERWRITE is #defined in your config
2317 file, the write protection for vendor parameters is
2318 completely disabled. Anybody can change or delete
2321 Alternatively, if you define _both_ an ethaddr in the
2322 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2323 Ethernet address is installed in the environment,
2324 which can be changed exactly ONCE by the user. [The
2325 serial# is unaffected by this, i. e. it remains
2328 The same can be accomplished in a more flexible way
2329 for any variable by configuring the type of access
2330 to allow for those variables in the ".flags" variable
2331 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2336 Define this variable to enable the reservation of
2337 "protected RAM", i. e. RAM which is not overwritten
2338 by U-Boot. Define CONFIG_PRAM to hold the number of
2339 kB you want to reserve for pRAM. You can overwrite
2340 this default value by defining an environment
2341 variable "pram" to the number of kB you want to
2342 reserve. Note that the board info structure will
2343 still show the full amount of RAM. If pRAM is
2344 reserved, a new environment variable "mem" will
2345 automatically be defined to hold the amount of
2346 remaining RAM in a form that can be passed as boot
2347 argument to Linux, for instance like that:
2349 setenv bootargs ... mem=\${mem}
2352 This way you can tell Linux not to use this memory,
2353 either, which results in a memory region that will
2354 not be affected by reboots.
2356 *WARNING* If your board configuration uses automatic
2357 detection of the RAM size, you must make sure that
2358 this memory test is non-destructive. So far, the
2359 following board configurations are known to be
2362 IVMS8, IVML24, SPD8xx,
2363 HERMES, IP860, RPXlite, LWMON,
2366 - Access to physical memory region (> 4GB)
2367 Some basic support is provided for operations on memory not
2368 normally accessible to U-Boot - e.g. some architectures
2369 support access to more than 4GB of memory on 32-bit
2370 machines using physical address extension or similar.
2371 Define CONFIG_PHYSMEM to access this basic support, which
2372 currently only supports clearing the memory.
2377 Define this variable to stop the system in case of a
2378 fatal error, so that you have to reset it manually.
2379 This is probably NOT a good idea for an embedded
2380 system where you want the system to reboot
2381 automatically as fast as possible, but it may be
2382 useful during development since you can try to debug
2383 the conditions that lead to the situation.
2385 CONFIG_NET_RETRY_COUNT
2387 This variable defines the number of retries for
2388 network operations like ARP, RARP, TFTP, or BOOTP
2389 before giving up the operation. If not defined, a
2390 default value of 5 is used.
2394 Timeout waiting for an ARP reply in milliseconds.
2398 Timeout in milliseconds used in NFS protocol.
2399 If you encounter "ERROR: Cannot umount" in nfs command,
2400 try longer timeout such as
2401 #define CONFIG_NFS_TIMEOUT 10000UL
2403 - Command Interpreter:
2404 CONFIG_AUTO_COMPLETE
2406 Enable auto completion of commands using TAB.
2408 CONFIG_SYS_PROMPT_HUSH_PS2
2410 This defines the secondary prompt string, which is
2411 printed when the command interpreter needs more input
2412 to complete a command. Usually "> ".
2416 In the current implementation, the local variables
2417 space and global environment variables space are
2418 separated. Local variables are those you define by
2419 simply typing `name=value'. To access a local
2420 variable later on, you have write `$name' or
2421 `${name}'; to execute the contents of a variable
2422 directly type `$name' at the command prompt.
2424 Global environment variables are those you use
2425 setenv/printenv to work with. To run a command stored
2426 in such a variable, you need to use the run command,
2427 and you must not use the '$' sign to access them.
2429 To store commands and special characters in a
2430 variable, please use double quotation marks
2431 surrounding the whole text of the variable, instead
2432 of the backslashes before semicolons and special
2435 - Command Line Editing and History:
2436 CONFIG_CMDLINE_EDITING
2438 Enable editing and History functions for interactive
2439 command line input operations
2441 - Command Line PS1/PS2 support:
2442 CONFIG_CMDLINE_PS_SUPPORT
2444 Enable support for changing the command prompt string
2445 at run-time. Only static string is supported so far.
2446 The string is obtained from environment variables PS1
2449 - Default Environment:
2450 CONFIG_EXTRA_ENV_SETTINGS
2452 Define this to contain any number of null terminated
2453 strings (variable = value pairs) that will be part of
2454 the default environment compiled into the boot image.
2456 For example, place something like this in your
2457 board's config file:
2459 #define CONFIG_EXTRA_ENV_SETTINGS \
2463 Warning: This method is based on knowledge about the
2464 internal format how the environment is stored by the
2465 U-Boot code. This is NOT an official, exported
2466 interface! Although it is unlikely that this format
2467 will change soon, there is no guarantee either.
2468 You better know what you are doing here.
2470 Note: overly (ab)use of the default environment is
2471 discouraged. Make sure to check other ways to preset
2472 the environment like the "source" command or the
2475 CONFIG_ENV_VARS_UBOOT_CONFIG
2477 Define this in order to add variables describing the
2478 U-Boot build configuration to the default environment.
2479 These will be named arch, cpu, board, vendor, and soc.
2481 Enabling this option will cause the following to be defined:
2489 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2491 Define this in order to add variables describing certain
2492 run-time determined information about the hardware to the
2493 environment. These will be named board_name, board_rev.
2495 CONFIG_DELAY_ENVIRONMENT
2497 Normally the environment is loaded when the board is
2498 initialised so that it is available to U-Boot. This inhibits
2499 that so that the environment is not available until
2500 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2501 this is instead controlled by the value of
2502 /config/load-environment.
2504 - DataFlash Support:
2505 CONFIG_HAS_DATAFLASH
2507 Defining this option enables DataFlash features and
2508 allows to read/write in Dataflash via the standard
2511 - Serial Flash support
2514 Defining this option enables SPI flash commands
2515 'sf probe/read/write/erase/update'.
2517 Usage requires an initial 'probe' to define the serial
2518 flash parameters, followed by read/write/erase/update
2521 The following defaults may be provided by the platform
2522 to handle the common case when only a single serial
2523 flash is present on the system.
2525 CONFIG_SF_DEFAULT_BUS Bus identifier
2526 CONFIG_SF_DEFAULT_CS Chip-select
2527 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2528 CONFIG_SF_DEFAULT_SPEED in Hz
2532 Define this option to include a destructive SPI flash
2535 - SystemACE Support:
2538 Adding this option adds support for Xilinx SystemACE
2539 chips attached via some sort of local bus. The address
2540 of the chip must also be defined in the
2541 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2543 #define CONFIG_SYSTEMACE
2544 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2546 When SystemACE support is added, the "ace" device type
2547 becomes available to the fat commands, i.e. fatls.
2549 - TFTP Fixed UDP Port:
2552 If this is defined, the environment variable tftpsrcp
2553 is used to supply the TFTP UDP source port value.
2554 If tftpsrcp isn't defined, the normal pseudo-random port
2555 number generator is used.
2557 Also, the environment variable tftpdstp is used to supply
2558 the TFTP UDP destination port value. If tftpdstp isn't
2559 defined, the normal port 69 is used.
2561 The purpose for tftpsrcp is to allow a TFTP server to
2562 blindly start the TFTP transfer using the pre-configured
2563 target IP address and UDP port. This has the effect of
2564 "punching through" the (Windows XP) firewall, allowing
2565 the remainder of the TFTP transfer to proceed normally.
2566 A better solution is to properly configure the firewall,
2567 but sometimes that is not allowed.
2569 - bootcount support:
2570 CONFIG_BOOTCOUNT_LIMIT
2572 This enables the bootcounter support, see:
2573 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2576 enable special bootcounter support on at91sam9xe based boards.
2578 enable special bootcounter support on da850 based boards.
2579 CONFIG_BOOTCOUNT_RAM
2580 enable support for the bootcounter in RAM
2581 CONFIG_BOOTCOUNT_I2C
2582 enable support for the bootcounter on an i2c (like RTC) device.
2583 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2584 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2586 CONFIG_BOOTCOUNT_ALEN = address len
2588 - Show boot progress:
2589 CONFIG_SHOW_BOOT_PROGRESS
2591 Defining this option allows to add some board-
2592 specific code (calling a user-provided function
2593 "show_boot_progress(int)") that enables you to show
2594 the system's boot progress on some display (for
2595 example, some LED's) on your board. At the moment,
2596 the following checkpoints are implemented:
2599 Legacy uImage format:
2602 1 common/cmd_bootm.c before attempting to boot an image
2603 -1 common/cmd_bootm.c Image header has bad magic number
2604 2 common/cmd_bootm.c Image header has correct magic number
2605 -2 common/cmd_bootm.c Image header has bad checksum
2606 3 common/cmd_bootm.c Image header has correct checksum
2607 -3 common/cmd_bootm.c Image data has bad checksum
2608 4 common/cmd_bootm.c Image data has correct checksum
2609 -4 common/cmd_bootm.c Image is for unsupported architecture
2610 5 common/cmd_bootm.c Architecture check OK
2611 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2612 6 common/cmd_bootm.c Image Type check OK
2613 -6 common/cmd_bootm.c gunzip uncompression error
2614 -7 common/cmd_bootm.c Unimplemented compression type
2615 7 common/cmd_bootm.c Uncompression OK
2616 8 common/cmd_bootm.c No uncompress/copy overwrite error
2617 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2619 9 common/image.c Start initial ramdisk verification
2620 -10 common/image.c Ramdisk header has bad magic number
2621 -11 common/image.c Ramdisk header has bad checksum
2622 10 common/image.c Ramdisk header is OK
2623 -12 common/image.c Ramdisk data has bad checksum
2624 11 common/image.c Ramdisk data has correct checksum
2625 12 common/image.c Ramdisk verification complete, start loading
2626 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2627 13 common/image.c Start multifile image verification
2628 14 common/image.c No initial ramdisk, no multifile, continue.
2630 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2632 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2633 -31 post/post.c POST test failed, detected by post_output_backlog()
2634 -32 post/post.c POST test failed, detected by post_run_single()
2636 34 common/cmd_doc.c before loading a Image from a DOC device
2637 -35 common/cmd_doc.c Bad usage of "doc" command
2638 35 common/cmd_doc.c correct usage of "doc" command
2639 -36 common/cmd_doc.c No boot device
2640 36 common/cmd_doc.c correct boot device
2641 -37 common/cmd_doc.c Unknown Chip ID on boot device
2642 37 common/cmd_doc.c correct chip ID found, device available
2643 -38 common/cmd_doc.c Read Error on boot device
2644 38 common/cmd_doc.c reading Image header from DOC device OK
2645 -39 common/cmd_doc.c Image header has bad magic number
2646 39 common/cmd_doc.c Image header has correct magic number
2647 -40 common/cmd_doc.c Error reading Image from DOC device
2648 40 common/cmd_doc.c Image header has correct magic number
2649 41 common/cmd_ide.c before loading a Image from a IDE device
2650 -42 common/cmd_ide.c Bad usage of "ide" command
2651 42 common/cmd_ide.c correct usage of "ide" command
2652 -43 common/cmd_ide.c No boot device
2653 43 common/cmd_ide.c boot device found
2654 -44 common/cmd_ide.c Device not available
2655 44 common/cmd_ide.c Device available
2656 -45 common/cmd_ide.c wrong partition selected
2657 45 common/cmd_ide.c partition selected
2658 -46 common/cmd_ide.c Unknown partition table
2659 46 common/cmd_ide.c valid partition table found
2660 -47 common/cmd_ide.c Invalid partition type
2661 47 common/cmd_ide.c correct partition type
2662 -48 common/cmd_ide.c Error reading Image Header on boot device
2663 48 common/cmd_ide.c reading Image Header from IDE device OK
2664 -49 common/cmd_ide.c Image header has bad magic number
2665 49 common/cmd_ide.c Image header has correct magic number
2666 -50 common/cmd_ide.c Image header has bad checksum
2667 50 common/cmd_ide.c Image header has correct checksum
2668 -51 common/cmd_ide.c Error reading Image from IDE device
2669 51 common/cmd_ide.c reading Image from IDE device OK
2670 52 common/cmd_nand.c before loading a Image from a NAND device
2671 -53 common/cmd_nand.c Bad usage of "nand" command
2672 53 common/cmd_nand.c correct usage of "nand" command
2673 -54 common/cmd_nand.c No boot device
2674 54 common/cmd_nand.c boot device found
2675 -55 common/cmd_nand.c Unknown Chip ID on boot device
2676 55 common/cmd_nand.c correct chip ID found, device available
2677 -56 common/cmd_nand.c Error reading Image Header on boot device
2678 56 common/cmd_nand.c reading Image Header from NAND device OK
2679 -57 common/cmd_nand.c Image header has bad magic number
2680 57 common/cmd_nand.c Image header has correct magic number
2681 -58 common/cmd_nand.c Error reading Image from NAND device
2682 58 common/cmd_nand.c reading Image from NAND device OK
2684 -60 common/env_common.c Environment has a bad CRC, using default
2686 64 net/eth.c starting with Ethernet configuration.
2687 -64 net/eth.c no Ethernet found.
2688 65 net/eth.c Ethernet found.
2690 -80 common/cmd_net.c usage wrong
2691 80 common/cmd_net.c before calling net_loop()
2692 -81 common/cmd_net.c some error in net_loop() occurred
2693 81 common/cmd_net.c net_loop() back without error
2694 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2695 82 common/cmd_net.c trying automatic boot
2696 83 common/cmd_net.c running "source" command
2697 -83 common/cmd_net.c some error in automatic boot or "source" command
2698 84 common/cmd_net.c end without errors
2703 100 common/cmd_bootm.c Kernel FIT Image has correct format
2704 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2705 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2706 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2707 102 common/cmd_bootm.c Kernel unit name specified
2708 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2709 103 common/cmd_bootm.c Found configuration node
2710 104 common/cmd_bootm.c Got kernel subimage node offset
2711 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2712 105 common/cmd_bootm.c Kernel subimage hash verification OK
2713 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2714 106 common/cmd_bootm.c Architecture check OK
2715 -106 common/cmd_bootm.c Kernel subimage has wrong type
2716 107 common/cmd_bootm.c Kernel subimage type OK
2717 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2718 108 common/cmd_bootm.c Got kernel subimage data/size
2719 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2720 -109 common/cmd_bootm.c Can't get kernel subimage type
2721 -110 common/cmd_bootm.c Can't get kernel subimage comp
2722 -111 common/cmd_bootm.c Can't get kernel subimage os
2723 -112 common/cmd_bootm.c Can't get kernel subimage load address
2724 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2726 120 common/image.c Start initial ramdisk verification
2727 -120 common/image.c Ramdisk FIT image has incorrect format
2728 121 common/image.c Ramdisk FIT image has correct format
2729 122 common/image.c No ramdisk subimage unit name, using configuration
2730 -122 common/image.c Can't get configuration for ramdisk subimage
2731 123 common/image.c Ramdisk unit name specified
2732 -124 common/image.c Can't get ramdisk subimage node offset
2733 125 common/image.c Got ramdisk subimage node offset
2734 -125 common/image.c Ramdisk subimage hash verification failed
2735 126 common/image.c Ramdisk subimage hash verification OK
2736 -126 common/image.c Ramdisk subimage for unsupported architecture
2737 127 common/image.c Architecture check OK
2738 -127 common/image.c Can't get ramdisk subimage data/size
2739 128 common/image.c Got ramdisk subimage data/size
2740 129 common/image.c Can't get ramdisk load address
2741 -129 common/image.c Got ramdisk load address
2743 -130 common/cmd_doc.c Incorrect FIT image format
2744 131 common/cmd_doc.c FIT image format OK
2746 -140 common/cmd_ide.c Incorrect FIT image format
2747 141 common/cmd_ide.c FIT image format OK
2749 -150 common/cmd_nand.c Incorrect FIT image format
2750 151 common/cmd_nand.c FIT image format OK
2752 - legacy image format:
2753 CONFIG_IMAGE_FORMAT_LEGACY
2754 enables the legacy image format support in U-Boot.
2757 enabled if CONFIG_FIT_SIGNATURE is not defined.
2759 CONFIG_DISABLE_IMAGE_LEGACY
2760 disable the legacy image format
2762 This define is introduced, as the legacy image format is
2763 enabled per default for backward compatibility.
2765 - Standalone program support:
2766 CONFIG_STANDALONE_LOAD_ADDR
2768 This option defines a board specific value for the
2769 address where standalone program gets loaded, thus
2770 overwriting the architecture dependent default
2773 - Frame Buffer Address:
2776 Define CONFIG_FB_ADDR if you want to use specific
2777 address for frame buffer. This is typically the case
2778 when using a graphics controller has separate video
2779 memory. U-Boot will then place the frame buffer at
2780 the given address instead of dynamically reserving it
2781 in system RAM by calling lcd_setmem(), which grabs
2782 the memory for the frame buffer depending on the
2783 configured panel size.
2785 Please see board_init_f function.
2787 - Automatic software updates via TFTP server
2789 CONFIG_UPDATE_TFTP_CNT_MAX
2790 CONFIG_UPDATE_TFTP_MSEC_MAX
2792 These options enable and control the auto-update feature;
2793 for a more detailed description refer to doc/README.update.
2795 - MTD Support (mtdparts command, UBI support)
2798 Adds the MTD device infrastructure from the Linux kernel.
2799 Needed for mtdparts command support.
2801 CONFIG_MTD_PARTITIONS
2803 Adds the MTD partitioning infrastructure from the Linux
2804 kernel. Needed for UBI support.
2809 Adds commands for interacting with MTD partitions formatted
2810 with the UBI flash translation layer
2812 Requires also defining CONFIG_RBTREE
2814 CONFIG_UBI_SILENCE_MSG
2816 Make the verbose messages from UBI stop printing. This leaves
2817 warnings and errors enabled.
2820 CONFIG_MTD_UBI_WL_THRESHOLD
2821 This parameter defines the maximum difference between the highest
2822 erase counter value and the lowest erase counter value of eraseblocks
2823 of UBI devices. When this threshold is exceeded, UBI starts performing
2824 wear leveling by means of moving data from eraseblock with low erase
2825 counter to eraseblocks with high erase counter.
2827 The default value should be OK for SLC NAND flashes, NOR flashes and
2828 other flashes which have eraseblock life-cycle 100000 or more.
2829 However, in case of MLC NAND flashes which typically have eraseblock
2830 life-cycle less than 10000, the threshold should be lessened (e.g.,
2831 to 128 or 256, although it does not have to be power of 2).
2835 CONFIG_MTD_UBI_BEB_LIMIT
2836 This option specifies the maximum bad physical eraseblocks UBI
2837 expects on the MTD device (per 1024 eraseblocks). If the
2838 underlying flash does not admit of bad eraseblocks (e.g. NOR
2839 flash), this value is ignored.
2841 NAND datasheets often specify the minimum and maximum NVM
2842 (Number of Valid Blocks) for the flashes' endurance lifetime.
2843 The maximum expected bad eraseblocks per 1024 eraseblocks
2844 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2845 which gives 20 for most NANDs (MaxNVB is basically the total
2846 count of eraseblocks on the chip).
2848 To put it differently, if this value is 20, UBI will try to
2849 reserve about 1.9% of physical eraseblocks for bad blocks
2850 handling. And that will be 1.9% of eraseblocks on the entire
2851 NAND chip, not just the MTD partition UBI attaches. This means
2852 that if you have, say, a NAND flash chip admits maximum 40 bad
2853 eraseblocks, and it is split on two MTD partitions of the same
2854 size, UBI will reserve 40 eraseblocks when attaching a
2859 CONFIG_MTD_UBI_FASTMAP
2860 Fastmap is a mechanism which allows attaching an UBI device
2861 in nearly constant time. Instead of scanning the whole MTD device it
2862 only has to locate a checkpoint (called fastmap) on the device.
2863 The on-flash fastmap contains all information needed to attach
2864 the device. Using fastmap makes only sense on large devices where
2865 attaching by scanning takes long. UBI will not automatically install
2866 a fastmap on old images, but you can set the UBI parameter
2867 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2868 that fastmap-enabled images are still usable with UBI implementations
2869 without fastmap support. On typical flash devices the whole fastmap
2870 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2872 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2873 Set this parameter to enable fastmap automatically on images
2877 CONFIG_MTD_UBI_FM_DEBUG
2878 Enable UBI fastmap debug
2884 Adds commands for interacting with UBI volumes formatted as
2885 UBIFS. UBIFS is read-only in u-boot.
2887 Requires UBI support as well as CONFIG_LZO
2889 CONFIG_UBIFS_SILENCE_MSG
2891 Make the verbose messages from UBIFS stop printing. This leaves
2892 warnings and errors enabled.
2896 Enable building of SPL globally.
2899 LDSCRIPT for linking the SPL binary.
2901 CONFIG_SPL_MAX_FOOTPRINT
2902 Maximum size in memory allocated to the SPL, BSS included.
2903 When defined, the linker checks that the actual memory
2904 used by SPL from _start to __bss_end does not exceed it.
2905 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2906 must not be both defined at the same time.
2909 Maximum size of the SPL image (text, data, rodata, and
2910 linker lists sections), BSS excluded.
2911 When defined, the linker checks that the actual size does
2914 CONFIG_SPL_TEXT_BASE
2915 TEXT_BASE for linking the SPL binary.
2917 CONFIG_SPL_RELOC_TEXT_BASE
2918 Address to relocate to. If unspecified, this is equal to
2919 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2921 CONFIG_SPL_BSS_START_ADDR
2922 Link address for the BSS within the SPL binary.
2924 CONFIG_SPL_BSS_MAX_SIZE
2925 Maximum size in memory allocated to the SPL BSS.
2926 When defined, the linker checks that the actual memory used
2927 by SPL from __bss_start to __bss_end does not exceed it.
2928 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2929 must not be both defined at the same time.
2932 Adress of the start of the stack SPL will use
2934 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2935 When defined, SPL will panic() if the image it has
2936 loaded does not have a signature.
2937 Defining this is useful when code which loads images
2938 in SPL cannot guarantee that absolutely all read errors
2940 An example is the LPC32XX MLC NAND driver, which will
2941 consider that a completely unreadable NAND block is bad,
2942 and thus should be skipped silently.
2944 CONFIG_SPL_RELOC_STACK
2945 Adress of the start of the stack SPL will use after
2946 relocation. If unspecified, this is equal to
2949 CONFIG_SYS_SPL_MALLOC_START
2950 Starting address of the malloc pool used in SPL.
2951 When this option is set the full malloc is used in SPL and
2952 it is set up by spl_init() and before that, the simple malloc()
2953 can be used if CONFIG_SYS_MALLOC_F is defined.
2955 CONFIG_SYS_SPL_MALLOC_SIZE
2956 The size of the malloc pool used in SPL.
2958 CONFIG_SPL_FRAMEWORK
2959 Enable the SPL framework under common/. This framework
2960 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2961 NAND loading of the Linux Kernel.
2964 Enable booting directly to an OS from SPL.
2965 See also: doc/README.falcon
2967 CONFIG_SPL_DISPLAY_PRINT
2968 For ARM, enable an optional function to print more information
2969 about the running system.
2971 CONFIG_SPL_INIT_MINIMAL
2972 Arch init code should be built for a very small image
2974 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2975 Partition on the MMC to load U-Boot from when the MMC is being
2978 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2979 Sector to load kernel uImage from when MMC is being
2980 used in raw mode (for Falcon mode)
2982 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2983 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2984 Sector and number of sectors to load kernel argument
2985 parameters from when MMC is being used in raw mode
2988 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2989 Partition on the MMC to load U-Boot from when the MMC is being
2992 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2993 Filename to read to load U-Boot when reading from filesystem
2995 CONFIG_SPL_FS_LOAD_KERNEL_NAME
2996 Filename to read to load kernel uImage when reading
2997 from filesystem (for Falcon mode)
2999 CONFIG_SPL_FS_LOAD_ARGS_NAME
3000 Filename to read to load kernel argument parameters
3001 when reading from filesystem (for Falcon mode)
3003 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3004 Set this for NAND SPL on PPC mpc83xx targets, so that
3005 start.S waits for the rest of the SPL to load before
3006 continuing (the hardware starts execution after just
3007 loading the first page rather than the full 4K).
3009 CONFIG_SPL_SKIP_RELOCATE
3010 Avoid SPL relocation
3012 CONFIG_SPL_NAND_BASE
3013 Include nand_base.c in the SPL. Requires
3014 CONFIG_SPL_NAND_DRIVERS.
3016 CONFIG_SPL_NAND_DRIVERS
3017 SPL uses normal NAND drivers, not minimal drivers.
3020 Include standard software ECC in the SPL
3022 CONFIG_SPL_NAND_SIMPLE
3023 Support for NAND boot using simple NAND drivers that
3024 expose the cmd_ctrl() interface.
3027 Support for a lightweight UBI (fastmap) scanner and
3030 CONFIG_SPL_NAND_RAW_ONLY
3031 Support to boot only raw u-boot.bin images. Use this only
3032 if you need to save space.
3034 CONFIG_SPL_COMMON_INIT_DDR
3035 Set for common ddr init with serial presence detect in
3038 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3039 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3040 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3041 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3042 CONFIG_SYS_NAND_ECCBYTES
3043 Defines the size and behavior of the NAND that SPL uses
3046 CONFIG_SPL_NAND_BOOT
3047 Add support NAND boot
3049 CONFIG_SYS_NAND_U_BOOT_OFFS
3050 Location in NAND to read U-Boot from
3052 CONFIG_SYS_NAND_U_BOOT_DST
3053 Location in memory to load U-Boot to
3055 CONFIG_SYS_NAND_U_BOOT_SIZE
3056 Size of image to load
3058 CONFIG_SYS_NAND_U_BOOT_START
3059 Entry point in loaded image to jump to
3061 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3062 Define this if you need to first read the OOB and then the
3063 data. This is used, for example, on davinci platforms.
3065 CONFIG_SPL_OMAP3_ID_NAND
3066 Support for an OMAP3-specific set of functions to return the
3067 ID and MFR of the first attached NAND chip, if present.
3069 CONFIG_SPL_RAM_DEVICE
3070 Support for running image already present in ram, in SPL binary
3073 Image offset to which the SPL should be padded before appending
3074 the SPL payload. By default, this is defined as
3075 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3076 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3077 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3080 Final target image containing SPL and payload. Some SPLs
3081 use an arch-specific makefile fragment instead, for
3082 example if more than one image needs to be produced.
3084 CONFIG_FIT_SPL_PRINT
3085 Printing information about a FIT image adds quite a bit of
3086 code to SPL. So this is normally disabled in SPL. Use this
3087 option to re-enable it. This will affect the output of the
3088 bootm command when booting a FIT image.
3092 Enable building of TPL globally.
3095 Image offset to which the TPL should be padded before appending
3096 the TPL payload. By default, this is defined as
3097 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3098 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3099 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3101 - Interrupt support (PPC):
3103 There are common interrupt_init() and timer_interrupt()
3104 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3105 for CPU specific initialization. interrupt_init_cpu()
3106 should set decrementer_count to appropriate value. If
3107 CPU resets decrementer automatically after interrupt
3108 (ppc4xx) it should set decrementer_count to zero.
3109 timer_interrupt() calls timer_interrupt_cpu() for CPU
3110 specific handling. If board has watchdog / status_led
3111 / other_activity_monitor it works automatically from
3112 general timer_interrupt().
3115 Board initialization settings:
3116 ------------------------------
3118 During Initialization u-boot calls a number of board specific functions
3119 to allow the preparation of board specific prerequisites, e.g. pin setup
3120 before drivers are initialized. To enable these callbacks the
3121 following configuration macros have to be defined. Currently this is
3122 architecture specific, so please check arch/your_architecture/lib/board.c
3123 typically in board_init_f() and board_init_r().
3125 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3126 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3127 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3128 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3130 Configuration Settings:
3131 -----------------------
3133 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3134 Optionally it can be defined to support 64-bit memory commands.
3136 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3137 undefine this when you're short of memory.
3139 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3140 width of the commands listed in the 'help' command output.
3142 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3143 prompt for user input.
3145 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3147 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3149 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3151 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3152 the application (usually a Linux kernel) when it is
3155 - CONFIG_SYS_BAUDRATE_TABLE:
3156 List of legal baudrate settings for this board.
3158 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3159 Begin and End addresses of the area used by the
3162 - CONFIG_SYS_ALT_MEMTEST:
3163 Enable an alternate, more extensive memory test.
3165 - CONFIG_SYS_MEMTEST_SCRATCH:
3166 Scratch address used by the alternate memory test
3167 You only need to set this if address zero isn't writeable
3169 - CONFIG_SYS_MEM_RESERVE_SECURE
3170 Only implemented for ARMv8 for now.
3171 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3172 is substracted from total RAM and won't be reported to OS.
3173 This memory can be used as secure memory. A variable
3174 gd->arch.secure_ram is used to track the location. In systems
3175 the RAM base is not zero, or RAM is divided into banks,
3176 this variable needs to be recalcuated to get the address.
3178 - CONFIG_SYS_MEM_TOP_HIDE:
3179 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3180 this specified memory area will get subtracted from the top
3181 (end) of RAM and won't get "touched" at all by U-Boot. By
3182 fixing up gd->ram_size the Linux kernel should gets passed
3183 the now "corrected" memory size and won't touch it either.
3184 This should work for arch/ppc and arch/powerpc. Only Linux
3185 board ports in arch/powerpc with bootwrapper support that
3186 recalculate the memory size from the SDRAM controller setup
3187 will have to get fixed in Linux additionally.
3189 This option can be used as a workaround for the 440EPx/GRx
3190 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3193 WARNING: Please make sure that this value is a multiple of
3194 the Linux page size (normally 4k). If this is not the case,
3195 then the end address of the Linux memory will be located at a
3196 non page size aligned address and this could cause major
3199 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3200 Enable temporary baudrate change while serial download
3202 - CONFIG_SYS_SDRAM_BASE:
3203 Physical start address of SDRAM. _Must_ be 0 here.
3205 - CONFIG_SYS_FLASH_BASE:
3206 Physical start address of Flash memory.
3208 - CONFIG_SYS_MONITOR_BASE:
3209 Physical start address of boot monitor code (set by
3210 make config files to be same as the text base address
3211 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3212 CONFIG_SYS_FLASH_BASE when booting from flash.
3214 - CONFIG_SYS_MONITOR_LEN:
3215 Size of memory reserved for monitor code, used to
3216 determine _at_compile_time_ (!) if the environment is
3217 embedded within the U-Boot image, or in a separate
3220 - CONFIG_SYS_MALLOC_LEN:
3221 Size of DRAM reserved for malloc() use.
3223 - CONFIG_SYS_MALLOC_F_LEN
3224 Size of the malloc() pool for use before relocation. If
3225 this is defined, then a very simple malloc() implementation
3226 will become available before relocation. The address is just
3227 below the global data, and the stack is moved down to make
3230 This feature allocates regions with increasing addresses
3231 within the region. calloc() is supported, but realloc()
3232 is not available. free() is supported but does nothing.
3233 The memory will be freed (or in fact just forgotten) when
3234 U-Boot relocates itself.
3236 - CONFIG_SYS_MALLOC_SIMPLE
3237 Provides a simple and small malloc() and calloc() for those
3238 boards which do not use the full malloc in SPL (which is
3239 enabled with CONFIG_SYS_SPL_MALLOC_START).
3241 - CONFIG_SYS_NONCACHED_MEMORY:
3242 Size of non-cached memory area. This area of memory will be
3243 typically located right below the malloc() area and mapped
3244 uncached in the MMU. This is useful for drivers that would
3245 otherwise require a lot of explicit cache maintenance. For
3246 some drivers it's also impossible to properly maintain the
3247 cache. For example if the regions that need to be flushed
3248 are not a multiple of the cache-line size, *and* padding
3249 cannot be allocated between the regions to align them (i.e.
3250 if the HW requires a contiguous array of regions, and the
3251 size of each region is not cache-aligned), then a flush of
3252 one region may result in overwriting data that hardware has
3253 written to another region in the same cache-line. This can
3254 happen for example in network drivers where descriptors for
3255 buffers are typically smaller than the CPU cache-line (e.g.
3256 16 bytes vs. 32 or 64 bytes).
3258 Non-cached memory is only supported on 32-bit ARM at present.
3260 - CONFIG_SYS_BOOTM_LEN:
3261 Normally compressed uImages are limited to an
3262 uncompressed size of 8 MBytes. If this is not enough,
3263 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3264 to adjust this setting to your needs.
3266 - CONFIG_SYS_BOOTMAPSZ:
3267 Maximum size of memory mapped by the startup code of
3268 the Linux kernel; all data that must be processed by
3269 the Linux kernel (bd_info, boot arguments, FDT blob if
3270 used) must be put below this limit, unless "bootm_low"
3271 environment variable is defined and non-zero. In such case
3272 all data for the Linux kernel must be between "bootm_low"
3273 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3274 variable "bootm_mapsize" will override the value of
3275 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3276 then the value in "bootm_size" will be used instead.
3278 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3279 Enable initrd_high functionality. If defined then the
3280 initrd_high feature is enabled and the bootm ramdisk subcommand
3283 - CONFIG_SYS_BOOT_GET_CMDLINE:
3284 Enables allocating and saving kernel cmdline in space between
3285 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3287 - CONFIG_SYS_BOOT_GET_KBD:
3288 Enables allocating and saving a kernel copy of the bd_info in
3289 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3291 - CONFIG_SYS_MAX_FLASH_BANKS:
3292 Max number of Flash memory banks
3294 - CONFIG_SYS_MAX_FLASH_SECT:
3295 Max number of sectors on a Flash chip
3297 - CONFIG_SYS_FLASH_ERASE_TOUT:
3298 Timeout for Flash erase operations (in ms)
3300 - CONFIG_SYS_FLASH_WRITE_TOUT:
3301 Timeout for Flash write operations (in ms)
3303 - CONFIG_SYS_FLASH_LOCK_TOUT
3304 Timeout for Flash set sector lock bit operation (in ms)
3306 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3307 Timeout for Flash clear lock bits operation (in ms)
3309 - CONFIG_SYS_FLASH_PROTECTION
3310 If defined, hardware flash sectors protection is used
3311 instead of U-Boot software protection.
3313 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3315 Enable TFTP transfers directly to flash memory;
3316 without this option such a download has to be
3317 performed in two steps: (1) download to RAM, and (2)
3318 copy from RAM to flash.
3320 The two-step approach is usually more reliable, since
3321 you can check if the download worked before you erase
3322 the flash, but in some situations (when system RAM is
3323 too limited to allow for a temporary copy of the
3324 downloaded image) this option may be very useful.
3326 - CONFIG_SYS_FLASH_CFI:
3327 Define if the flash driver uses extra elements in the
3328 common flash structure for storing flash geometry.
3330 - CONFIG_FLASH_CFI_DRIVER
3331 This option also enables the building of the cfi_flash driver
3332 in the drivers directory
3334 - CONFIG_FLASH_CFI_MTD
3335 This option enables the building of the cfi_mtd driver
3336 in the drivers directory. The driver exports CFI flash
3339 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3340 Use buffered writes to flash.
3342 - CONFIG_FLASH_SPANSION_S29WS_N
3343 s29ws-n MirrorBit flash has non-standard addresses for buffered
3346 - CONFIG_SYS_FLASH_QUIET_TEST
3347 If this option is defined, the common CFI flash doesn't
3348 print it's warning upon not recognized FLASH banks. This
3349 is useful, if some of the configured banks are only
3350 optionally available.
3352 - CONFIG_FLASH_SHOW_PROGRESS
3353 If defined (must be an integer), print out countdown
3354 digits and dots. Recommended value: 45 (9..1) for 80
3355 column displays, 15 (3..1) for 40 column displays.
3357 - CONFIG_FLASH_VERIFY
3358 If defined, the content of the flash (destination) is compared
3359 against the source after the write operation. An error message
3360 will be printed when the contents are not identical.
3361 Please note that this option is useless in nearly all cases,
3362 since such flash programming errors usually are detected earlier
3363 while unprotecting/erasing/programming. Please only enable
3364 this option if you really know what you are doing.
3366 - CONFIG_SYS_RX_ETH_BUFFER:
3367 Defines the number of Ethernet receive buffers. On some
3368 Ethernet controllers it is recommended to set this value
3369 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3370 buffers can be full shortly after enabling the interface
3371 on high Ethernet traffic.
3372 Defaults to 4 if not defined.
3374 - CONFIG_ENV_MAX_ENTRIES
3376 Maximum number of entries in the hash table that is used
3377 internally to store the environment settings. The default
3378 setting is supposed to be generous and should work in most
3379 cases. This setting can be used to tune behaviour; see
3380 lib/hashtable.c for details.
3382 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3383 - CONFIG_ENV_FLAGS_LIST_STATIC
3384 Enable validation of the values given to environment variables when
3385 calling env set. Variables can be restricted to only decimal,
3386 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3387 the variables can also be restricted to IP address or MAC address.
3389 The format of the list is:
3390 type_attribute = [s|d|x|b|i|m]
3391 access_attribute = [a|r|o|c]
3392 attributes = type_attribute[access_attribute]
3393 entry = variable_name[:attributes]
3396 The type attributes are:
3397 s - String (default)
3400 b - Boolean ([1yYtT|0nNfF])
3404 The access attributes are:
3410 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3411 Define this to a list (string) to define the ".flags"
3412 environment variable in the default or embedded environment.
3414 - CONFIG_ENV_FLAGS_LIST_STATIC
3415 Define this to a list (string) to define validation that
3416 should be done if an entry is not found in the ".flags"
3417 environment variable. To override a setting in the static
3418 list, simply add an entry for the same variable name to the
3421 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3422 regular expression. This allows multiple variables to define the same
3423 flags without explicitly listing them for each variable.
3425 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3426 If defined, don't allow the -f switch to env set override variable
3430 If stdint.h is available with your toolchain you can define this
3431 option to enable it. You can provide option 'USE_STDINT=1' when
3432 building U-Boot to enable this.
3434 The following definitions that deal with the placement and management
3435 of environment data (variable area); in general, we support the
3436 following configurations:
3438 - CONFIG_BUILD_ENVCRC:
3440 Builds up envcrc with the target environment so that external utils
3441 may easily extract it and embed it in final U-Boot images.
3443 - CONFIG_ENV_IS_IN_FLASH:
3445 Define this if the environment is in flash memory.
3447 a) The environment occupies one whole flash sector, which is
3448 "embedded" in the text segment with the U-Boot code. This
3449 happens usually with "bottom boot sector" or "top boot
3450 sector" type flash chips, which have several smaller
3451 sectors at the start or the end. For instance, such a
3452 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3453 such a case you would place the environment in one of the
3454 4 kB sectors - with U-Boot code before and after it. With
3455 "top boot sector" type flash chips, you would put the
3456 environment in one of the last sectors, leaving a gap
3457 between U-Boot and the environment.
3459 - CONFIG_ENV_OFFSET:
3461 Offset of environment data (variable area) to the
3462 beginning of flash memory; for instance, with bottom boot
3463 type flash chips the second sector can be used: the offset
3464 for this sector is given here.
3466 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3470 This is just another way to specify the start address of
3471 the flash sector containing the environment (instead of
3474 - CONFIG_ENV_SECT_SIZE:
3476 Size of the sector containing the environment.
3479 b) Sometimes flash chips have few, equal sized, BIG sectors.
3480 In such a case you don't want to spend a whole sector for
3485 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3486 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3487 of this flash sector for the environment. This saves
3488 memory for the RAM copy of the environment.
3490 It may also save flash memory if you decide to use this
3491 when your environment is "embedded" within U-Boot code,
3492 since then the remainder of the flash sector could be used
3493 for U-Boot code. It should be pointed out that this is
3494 STRONGLY DISCOURAGED from a robustness point of view:
3495 updating the environment in flash makes it always
3496 necessary to erase the WHOLE sector. If something goes
3497 wrong before the contents has been restored from a copy in
3498 RAM, your target system will be dead.
3500 - CONFIG_ENV_ADDR_REDUND
3501 CONFIG_ENV_SIZE_REDUND
3503 These settings describe a second storage area used to hold
3504 a redundant copy of the environment data, so that there is
3505 a valid backup copy in case there is a power failure during
3506 a "saveenv" operation.
3508 BE CAREFUL! Any changes to the flash layout, and some changes to the
3509 source code will make it necessary to adapt <board>/u-boot.lds*
3513 - CONFIG_ENV_IS_IN_NVRAM:
3515 Define this if you have some non-volatile memory device
3516 (NVRAM, battery buffered SRAM) which you want to use for the
3522 These two #defines are used to determine the memory area you
3523 want to use for environment. It is assumed that this memory
3524 can just be read and written to, without any special
3527 BE CAREFUL! The first access to the environment happens quite early
3528 in U-Boot initialization (when we try to get the setting of for the
3529 console baudrate). You *MUST* have mapped your NVRAM area then, or
3532 Please note that even with NVRAM we still use a copy of the
3533 environment in RAM: we could work on NVRAM directly, but we want to
3534 keep settings there always unmodified except somebody uses "saveenv"
3535 to save the current settings.
3538 - CONFIG_ENV_IS_IN_EEPROM:
3540 Use this if you have an EEPROM or similar serial access
3541 device and a driver for it.
3543 - CONFIG_ENV_OFFSET:
3546 These two #defines specify the offset and size of the
3547 environment area within the total memory of your EEPROM.
3549 - CONFIG_SYS_I2C_EEPROM_ADDR:
3550 If defined, specified the chip address of the EEPROM device.
3551 The default address is zero.
3553 - CONFIG_SYS_I2C_EEPROM_BUS:
3554 If defined, specified the i2c bus of the EEPROM device.
3556 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3557 If defined, the number of bits used to address bytes in a
3558 single page in the EEPROM device. A 64 byte page, for example
3559 would require six bits.
3561 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3562 If defined, the number of milliseconds to delay between
3563 page writes. The default is zero milliseconds.
3565 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3566 The length in bytes of the EEPROM memory array address. Note
3567 that this is NOT the chip address length!
3569 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3570 EEPROM chips that implement "address overflow" are ones
3571 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3572 address and the extra bits end up in the "chip address" bit
3573 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3576 Note that we consider the length of the address field to
3577 still be one byte because the extra address bits are hidden
3578 in the chip address.
3580 - CONFIG_SYS_EEPROM_SIZE:
3581 The size in bytes of the EEPROM device.
3583 - CONFIG_ENV_EEPROM_IS_ON_I2C
3584 define this, if you have I2C and SPI activated, and your
3585 EEPROM, which holds the environment, is on the I2C bus.
3587 - CONFIG_I2C_ENV_EEPROM_BUS
3588 if you have an Environment on an EEPROM reached over
3589 I2C muxes, you can define here, how to reach this
3590 EEPROM. For example:
3592 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3594 EEPROM which holds the environment, is reached over
3595 a pca9547 i2c mux with address 0x70, channel 3.
3597 - CONFIG_ENV_IS_IN_DATAFLASH:
3599 Define this if you have a DataFlash memory device which you
3600 want to use for the environment.
3602 - CONFIG_ENV_OFFSET:
3606 These three #defines specify the offset and size of the
3607 environment area within the total memory of your DataFlash placed
3608 at the specified address.
3610 - CONFIG_ENV_IS_IN_SPI_FLASH:
3612 Define this if you have a SPI Flash memory device which you
3613 want to use for the environment.
3615 - CONFIG_ENV_OFFSET:
3618 These two #defines specify the offset and size of the
3619 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
3620 aligned to an erase sector boundary.
3622 - CONFIG_ENV_SECT_SIZE:
3624 Define the SPI flash's sector size.
3626 - CONFIG_ENV_OFFSET_REDUND (optional):
3628 This setting describes a second storage area of CONFIG_ENV_SIZE
3629 size used to hold a redundant copy of the environment data, so
3630 that there is a valid backup copy in case there is a power failure
3631 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3632 aligned to an erase sector boundary.
3634 - CONFIG_ENV_SPI_BUS (optional):
3635 - CONFIG_ENV_SPI_CS (optional):
3637 Define the SPI bus and chip select. If not defined they will be 0.
3639 - CONFIG_ENV_SPI_MAX_HZ (optional):
3641 Define the SPI max work clock. If not defined then use 1MHz.
3643 - CONFIG_ENV_SPI_MODE (optional):
3645 Define the SPI work mode. If not defined then use SPI_MODE_3.
3647 - CONFIG_ENV_IS_IN_REMOTE:
3649 Define this if you have a remote memory space which you
3650 want to use for the local device's environment.
3655 These two #defines specify the address and size of the
3656 environment area within the remote memory space. The
3657 local device can get the environment from remote memory
3658 space by SRIO or PCIE links.
3660 BE CAREFUL! For some special cases, the local device can not use
3661 "saveenv" command. For example, the local device will get the
3662 environment stored in a remote NOR flash by SRIO or PCIE link,
3663 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3665 - CONFIG_ENV_IS_IN_NAND:
3667 Define this if you have a NAND device which you want to use
3668 for the environment.
3670 - CONFIG_ENV_OFFSET:
3673 These two #defines specify the offset and size of the environment
3674 area within the first NAND device. CONFIG_ENV_OFFSET must be
3675 aligned to an erase block boundary.
3677 - CONFIG_ENV_OFFSET_REDUND (optional):
3679 This setting describes a second storage area of CONFIG_ENV_SIZE
3680 size used to hold a redundant copy of the environment data, so
3681 that there is a valid backup copy in case there is a power failure
3682 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3683 aligned to an erase block boundary.
3685 - CONFIG_ENV_RANGE (optional):
3687 Specifies the length of the region in which the environment
3688 can be written. This should be a multiple of the NAND device's
3689 block size. Specifying a range with more erase blocks than
3690 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3691 the range to be avoided.
3693 - CONFIG_ENV_OFFSET_OOB (optional):
3695 Enables support for dynamically retrieving the offset of the
3696 environment from block zero's out-of-band data. The
3697 "nand env.oob" command can be used to record this offset.
3698 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3699 using CONFIG_ENV_OFFSET_OOB.
3701 - CONFIG_NAND_ENV_DST
3703 Defines address in RAM to which the nand_spl code should copy the
3704 environment. If redundant environment is used, it will be copied to
3705 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3707 - CONFIG_ENV_IS_IN_UBI:
3709 Define this if you have an UBI volume that you want to use for the
3710 environment. This has the benefit of wear-leveling the environment
3711 accesses, which is important on NAND.
3713 - CONFIG_ENV_UBI_PART:
3715 Define this to a string that is the mtd partition containing the UBI.
3717 - CONFIG_ENV_UBI_VOLUME:
3719 Define this to the name of the volume that you want to store the
3722 - CONFIG_ENV_UBI_VOLUME_REDUND:
3724 Define this to the name of another volume to store a second copy of
3725 the environment in. This will enable redundant environments in UBI.
3726 It is assumed that both volumes are in the same MTD partition.
3728 - CONFIG_UBI_SILENCE_MSG
3729 - CONFIG_UBIFS_SILENCE_MSG
3731 You will probably want to define these to avoid a really noisy system
3732 when storing the env in UBI.
3734 - CONFIG_ENV_IS_IN_FAT:
3735 Define this if you want to use the FAT file system for the environment.
3737 - FAT_ENV_INTERFACE:
3739 Define this to a string that is the name of the block device.
3741 - FAT_ENV_DEVICE_AND_PART:
3743 Define this to a string to specify the partition of the device. It can
3746 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
3747 - "D:P": device D partition P. Error occurs if device D has no
3750 - "D" or "D:": device D partition 1 if device D has partition
3751 table, or the whole device D if has no partition
3753 - "D:auto": first partition in device D with bootable flag set.
3754 If none, first valid partition in device D. If no
3755 partition table then means device D.
3759 It's a string of the FAT file name. This file use to store the
3763 This must be enabled. Otherwise it cannot save the environment file.
3765 - CONFIG_ENV_IS_IN_MMC:
3767 Define this if you have an MMC device which you want to use for the
3770 - CONFIG_SYS_MMC_ENV_DEV:
3772 Specifies which MMC device the environment is stored in.
3774 - CONFIG_SYS_MMC_ENV_PART (optional):
3776 Specifies which MMC partition the environment is stored in. If not
3777 set, defaults to partition 0, the user area. Common values might be
3778 1 (first MMC boot partition), 2 (second MMC boot partition).
3780 - CONFIG_ENV_OFFSET:
3783 These two #defines specify the offset and size of the environment
3784 area within the specified MMC device.
3786 If offset is positive (the usual case), it is treated as relative to
3787 the start of the MMC partition. If offset is negative, it is treated
3788 as relative to the end of the MMC partition. This can be useful if
3789 your board may be fitted with different MMC devices, which have
3790 different sizes for the MMC partitions, and you always want the
3791 environment placed at the very end of the partition, to leave the
3792 maximum possible space before it, to store other data.
3794 These two values are in units of bytes, but must be aligned to an
3795 MMC sector boundary.
3797 - CONFIG_ENV_OFFSET_REDUND (optional):
3799 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3800 hold a redundant copy of the environment data. This provides a
3801 valid backup copy in case the other copy is corrupted, e.g. due
3802 to a power failure during a "saveenv" operation.
3804 This value may also be positive or negative; this is handled in the
3805 same way as CONFIG_ENV_OFFSET.
3807 This value is also in units of bytes, but must also be aligned to
3808 an MMC sector boundary.
3810 - CONFIG_ENV_SIZE_REDUND (optional):
3812 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3813 set. If this value is set, it must be set to the same value as
3816 Please note that the environment is read-only until the monitor
3817 has been relocated to RAM and a RAM copy of the environment has been
3818 created; also, when using EEPROM you will have to use getenv_f()
3819 until then to read environment variables.
3821 The environment is protected by a CRC32 checksum. Before the monitor
3822 is relocated into RAM, as a result of a bad CRC you will be working
3823 with the compiled-in default environment - *silently*!!! [This is
3824 necessary, because the first environment variable we need is the
3825 "baudrate" setting for the console - if we have a bad CRC, we don't
3826 have any device yet where we could complain.]
3828 Note: once the monitor has been relocated, then it will complain if
3829 the default environment is used; a new CRC is computed as soon as you
3830 use the "saveenv" command to store a valid environment.
3832 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3833 Echo the inverted Ethernet link state to the fault LED.
3835 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3836 also needs to be defined.
3838 - CONFIG_SYS_FAULT_MII_ADDR:
3839 MII address of the PHY to check for the Ethernet link state.
3841 - CONFIG_NS16550_MIN_FUNCTIONS:
3842 Define this if you desire to only have use of the NS16550_init
3843 and NS16550_putc functions for the serial driver located at
3844 drivers/serial/ns16550.c. This option is useful for saving
3845 space for already greatly restricted images, including but not
3846 limited to NAND_SPL configurations.
3848 - CONFIG_DISPLAY_BOARDINFO
3849 Display information about the board that U-Boot is running on
3850 when U-Boot starts up. The board function checkboard() is called
3853 - CONFIG_DISPLAY_BOARDINFO_LATE
3854 Similar to the previous option, but display this information
3855 later, once stdio is running and output goes to the LCD, if
3858 - CONFIG_BOARD_SIZE_LIMIT:
3859 Maximum size of the U-Boot image. When defined, the
3860 build system checks that the actual size does not
3863 Low Level (hardware related) configuration options:
3864 ---------------------------------------------------
3866 - CONFIG_SYS_CACHELINE_SIZE:
3867 Cache Line Size of the CPU.
3869 - CONFIG_SYS_CCSRBAR_DEFAULT:
3870 Default (power-on reset) physical address of CCSR on Freescale
3873 - CONFIG_SYS_CCSRBAR:
3874 Virtual address of CCSR. On a 32-bit build, this is typically
3875 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3877 - CONFIG_SYS_CCSRBAR_PHYS:
3878 Physical address of CCSR. CCSR can be relocated to a new
3879 physical address, if desired. In this case, this macro should
3880 be set to that address. Otherwise, it should be set to the
3881 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3882 is typically relocated on 36-bit builds. It is recommended
3883 that this macro be defined via the _HIGH and _LOW macros:
3885 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3886 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3888 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3889 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3890 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3891 used in assembly code, so it must not contain typecasts or
3892 integer size suffixes (e.g. "ULL").
3894 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3895 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3896 used in assembly code, so it must not contain typecasts or
3897 integer size suffixes (e.g. "ULL").
3899 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3900 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3901 forced to a value that ensures that CCSR is not relocated.
3903 - Floppy Disk Support:
3904 CONFIG_SYS_FDC_DRIVE_NUMBER
3906 the default drive number (default value 0)
3908 CONFIG_SYS_ISA_IO_STRIDE
3910 defines the spacing between FDC chipset registers
3913 CONFIG_SYS_ISA_IO_OFFSET
3915 defines the offset of register from address. It
3916 depends on which part of the data bus is connected to
3917 the FDC chipset. (default value 0)
3919 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3920 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3923 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3924 fdc_hw_init() is called at the beginning of the FDC
3925 setup. fdc_hw_init() must be provided by the board
3926 source code. It is used to make hardware-dependent
3930 Most IDE controllers were designed to be connected with PCI
3931 interface. Only few of them were designed for AHB interface.
3932 When software is doing ATA command and data transfer to
3933 IDE devices through IDE-AHB controller, some additional
3934 registers accessing to these kind of IDE-AHB controller
3937 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3938 DO NOT CHANGE unless you know exactly what you're
3939 doing! (11-4) [82xx systems only]
3941 - CONFIG_SYS_INIT_RAM_ADDR:
3943 Start address of memory area that can be used for
3944 initial data and stack; please note that this must be
3945 writable memory that is working WITHOUT special
3946 initialization, i. e. you CANNOT use normal RAM which
3947 will become available only after programming the
3948 memory controller and running certain initialization
3951 U-Boot uses the following memory types:
3953 - CONFIG_SYS_GBL_DATA_OFFSET:
3955 Offset of the initial data structure in the memory
3956 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3957 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3958 data is located at the end of the available space
3959 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3960 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3961 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3962 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3965 On the MPC824X (or other systems that use the data
3966 cache for initial memory) the address chosen for
3967 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3968 point to an otherwise UNUSED address space between
3969 the top of RAM and the start of the PCI space.
3971 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3973 - CONFIG_SYS_OR_TIMING_SDRAM:
3976 - CONFIG_SYS_MAMR_PTA:
3977 periodic timer for refresh
3979 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3980 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3981 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3982 CONFIG_SYS_BR1_PRELIM:
3983 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3985 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3986 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3987 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3988 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3990 - CONFIG_PCI_ENUM_ONLY
3991 Only scan through and get the devices on the buses.
3992 Don't do any setup work, presumably because someone or
3993 something has already done it, and we don't need to do it
3994 a second time. Useful for platforms that are pre-booted
3995 by coreboot or similar.
3997 - CONFIG_PCI_INDIRECT_BRIDGE:
3998 Enable support for indirect PCI bridges.
4001 Chip has SRIO or not
4004 Board has SRIO 1 port available
4007 Board has SRIO 2 port available
4009 - CONFIG_SRIO_PCIE_BOOT_MASTER
4010 Board can support master function for Boot from SRIO and PCIE
4012 - CONFIG_SYS_SRIOn_MEM_VIRT:
4013 Virtual Address of SRIO port 'n' memory region
4015 - CONFIG_SYS_SRIOn_MEM_PHYS:
4016 Physical Address of SRIO port 'n' memory region
4018 - CONFIG_SYS_SRIOn_MEM_SIZE:
4019 Size of SRIO port 'n' memory region
4021 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4022 Defined to tell the NAND controller that the NAND chip is using
4024 Not all NAND drivers use this symbol.
4025 Example of drivers that use it:
4026 - drivers/mtd/nand/ndfc.c
4027 - drivers/mtd/nand/mxc_nand.c
4029 - CONFIG_SYS_NDFC_EBC0_CFG
4030 Sets the EBC0_CFG register for the NDFC. If not defined
4031 a default value will be used.
4034 Get DDR timing information from an I2C EEPROM. Common
4035 with pluggable memory modules such as SODIMMs
4038 I2C address of the SPD EEPROM
4040 - CONFIG_SYS_SPD_BUS_NUM
4041 If SPD EEPROM is on an I2C bus other than the first
4042 one, specify here. Note that the value must resolve
4043 to something your driver can deal with.
4045 - CONFIG_SYS_DDR_RAW_TIMING
4046 Get DDR timing information from other than SPD. Common with
4047 soldered DDR chips onboard without SPD. DDR raw timing
4048 parameters are extracted from datasheet and hard-coded into
4049 header files or board specific files.
4051 - CONFIG_FSL_DDR_INTERACTIVE
4052 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4054 - CONFIG_FSL_DDR_SYNC_REFRESH
4055 Enable sync of refresh for multiple controllers.
4057 - CONFIG_FSL_DDR_BIST
4058 Enable built-in memory test for Freescale DDR controllers.
4060 - CONFIG_SYS_83XX_DDR_USES_CS0
4061 Only for 83xx systems. If specified, then DDR should
4062 be configured using CS0 and CS1 instead of CS2 and CS3.
4065 Enable RMII mode for all FECs.
4066 Note that this is a global option, we can't
4067 have one FEC in standard MII mode and another in RMII mode.
4069 - CONFIG_CRC32_VERIFY
4070 Add a verify option to the crc32 command.
4073 => crc32 -v <address> <count> <crc32>
4075 Where address/count indicate a memory area
4076 and crc32 is the correct crc32 which the
4080 Add the "loopw" memory command. This only takes effect if
4081 the memory commands are activated globally (CONFIG_CMD_MEM).
4084 Add the "mdc" and "mwc" memory commands. These are cyclic
4089 This command will print 4 bytes (10,11,12,13) each 500 ms.
4091 => mwc.l 100 12345678 10
4092 This command will write 12345678 to address 100 all 10 ms.
4094 This only takes effect if the memory commands are activated
4095 globally (CONFIG_CMD_MEM).
4097 - CONFIG_SKIP_LOWLEVEL_INIT
4098 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4099 low level initializations (like setting up the memory
4100 controller) are omitted and/or U-Boot does not
4101 relocate itself into RAM.
4103 Normally this variable MUST NOT be defined. The only
4104 exception is when U-Boot is loaded (to RAM) by some
4105 other boot loader or by a debugger which performs
4106 these initializations itself.
4108 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4109 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4110 to be skipped. The normal CP15 init (such as enabling the
4111 instruction cache) is still performed.
4114 Modifies the behaviour of start.S when compiling a loader
4115 that is executed before the actual U-Boot. E.g. when
4116 compiling a NAND SPL.
4119 Modifies the behaviour of start.S when compiling a loader
4120 that is executed after the SPL and before the actual U-Boot.
4121 It is loaded by the SPL.
4123 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4124 Only for 85xx systems. If this variable is specified, the section
4125 .resetvec is not kept and the section .bootpg is placed in the
4126 previous 4k of the .text section.
4128 - CONFIG_ARCH_MAP_SYSMEM
4129 Generally U-Boot (and in particular the md command) uses
4130 effective address. It is therefore not necessary to regard
4131 U-Boot address as virtual addresses that need to be translated
4132 to physical addresses. However, sandbox requires this, since
4133 it maintains its own little RAM buffer which contains all
4134 addressable memory. This option causes some memory accesses
4135 to be mapped through map_sysmem() / unmap_sysmem().
4137 - CONFIG_X86_RESET_VECTOR
4138 If defined, the x86 reset vector code is included. This is not
4139 needed when U-Boot is running from Coreboot.
4141 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4142 Enables the RTC32K OSC on AM33xx based plattforms
4144 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4145 Option to disable subpage write in NAND driver
4146 driver that uses this:
4147 drivers/mtd/nand/davinci_nand.c
4149 Freescale QE/FMAN Firmware Support:
4150 -----------------------------------
4152 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4153 loading of "firmware", which is encoded in the QE firmware binary format.
4154 This firmware often needs to be loaded during U-Boot booting, so macros
4155 are used to identify the storage device (NOR flash, SPI, etc) and the address
4158 - CONFIG_SYS_FMAN_FW_ADDR
4159 The address in the storage device where the FMAN microcode is located. The
4160 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4163 - CONFIG_SYS_QE_FW_ADDR
4164 The address in the storage device where the QE microcode is located. The
4165 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4168 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4169 The maximum possible size of the firmware. The firmware binary format
4170 has a field that specifies the actual size of the firmware, but it
4171 might not be possible to read any part of the firmware unless some
4172 local storage is allocated to hold the entire firmware first.
4174 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4175 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4176 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4177 virtual address in NOR flash.
4179 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4180 Specifies that QE/FMAN firmware is located in NAND flash.
4181 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4183 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4184 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4185 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4187 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4188 Specifies that QE/FMAN firmware is located in the remote (master)
4189 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4190 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4191 window->master inbound window->master LAW->the ucode address in
4192 master's memory space.
4194 Freescale Layerscape Management Complex Firmware Support:
4195 ---------------------------------------------------------
4196 The Freescale Layerscape Management Complex (MC) supports the loading of
4198 This firmware often needs to be loaded during U-Boot booting, so macros
4199 are used to identify the storage device (NOR flash, SPI, etc) and the address
4202 - CONFIG_FSL_MC_ENET
4203 Enable the MC driver for Layerscape SoCs.
4205 Freescale Layerscape Debug Server Support:
4206 -------------------------------------------
4207 The Freescale Layerscape Debug Server Support supports the loading of
4208 "Debug Server firmware" and triggering SP boot-rom.
4209 This firmware often needs to be loaded during U-Boot booting.
4211 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4212 Define alignment of reserved memory MC requires
4217 In order to achieve reproducible builds, timestamps used in the U-Boot build
4218 process have to be set to a fixed value.
4220 This is done using the SOURCE_DATE_EPOCH environment variable.
4221 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4222 option for U-Boot or an environment variable in U-Boot.
4224 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4226 Building the Software:
4227 ======================
4229 Building U-Boot has been tested in several native build environments
4230 and in many different cross environments. Of course we cannot support
4231 all possibly existing versions of cross development tools in all
4232 (potentially obsolete) versions. In case of tool chain problems we
4233 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4234 which is extensively used to build and test U-Boot.
4236 If you are not using a native environment, it is assumed that you
4237 have GNU cross compiling tools available in your path. In this case,
4238 you must set the environment variable CROSS_COMPILE in your shell.
4239 Note that no changes to the Makefile or any other source files are
4240 necessary. For example using the ELDK on a 4xx CPU, please enter:
4242 $ CROSS_COMPILE=ppc_4xx-
4243 $ export CROSS_COMPILE
4245 Note: If you wish to generate Windows versions of the utilities in
4246 the tools directory you can use the MinGW toolchain
4247 (http://www.mingw.org). Set your HOST tools to the MinGW
4248 toolchain and execute 'make tools'. For example:
4250 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4252 Binaries such as tools/mkimage.exe will be created which can
4253 be executed on computers running Windows.
4255 U-Boot is intended to be simple to build. After installing the
4256 sources you must configure U-Boot for one specific board type. This
4261 where "NAME_defconfig" is the name of one of the existing configu-
4262 rations; see boards.cfg for supported names.
4264 Note: for some board special configuration names may exist; check if
4265 additional information is available from the board vendor; for
4266 instance, the TQM823L systems are available without (standard)
4267 or with LCD support. You can select such additional "features"
4268 when choosing the configuration, i. e.
4270 make TQM823L_defconfig
4271 - will configure for a plain TQM823L, i. e. no LCD support
4273 make TQM823L_LCD_defconfig
4274 - will configure for a TQM823L with U-Boot console on LCD
4279 Finally, type "make all", and you should get some working U-Boot
4280 images ready for download to / installation on your system:
4282 - "u-boot.bin" is a raw binary image
4283 - "u-boot" is an image in ELF binary format
4284 - "u-boot.srec" is in Motorola S-Record format
4286 By default the build is performed locally and the objects are saved
4287 in the source directory. One of the two methods can be used to change
4288 this behavior and build U-Boot to some external directory:
4290 1. Add O= to the make command line invocations:
4292 make O=/tmp/build distclean
4293 make O=/tmp/build NAME_defconfig
4294 make O=/tmp/build all
4296 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4298 export KBUILD_OUTPUT=/tmp/build
4303 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4307 Please be aware that the Makefiles assume you are using GNU make, so
4308 for instance on NetBSD you might need to use "gmake" instead of
4312 If the system board that you have is not listed, then you will need
4313 to port U-Boot to your hardware platform. To do this, follow these
4316 1. Create a new directory to hold your board specific code. Add any
4317 files you need. In your board directory, you will need at least
4318 the "Makefile" and a "<board>.c".
4319 2. Create a new configuration file "include/configs/<board>.h" for
4321 3. If you're porting U-Boot to a new CPU, then also create a new
4322 directory to hold your CPU specific code. Add any files you need.
4323 4. Run "make <board>_defconfig" with your new name.
4324 5. Type "make", and you should get a working "u-boot.srec" file
4325 to be installed on your target system.
4326 6. Debug and solve any problems that might arise.
4327 [Of course, this last step is much harder than it sounds.]
4330 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4331 ==============================================================
4333 If you have modified U-Boot sources (for instance added a new board
4334 or support for new devices, a new CPU, etc.) you are expected to
4335 provide feedback to the other developers. The feedback normally takes
4336 the form of a "patch", i. e. a context diff against a certain (latest
4337 official or latest in the git repository) version of U-Boot sources.
4339 But before you submit such a patch, please verify that your modifi-
4340 cation did not break existing code. At least make sure that *ALL* of
4341 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4342 just run the buildman script (tools/buildman/buildman), which will
4343 configure and build U-Boot for ALL supported system. Be warned, this
4344 will take a while. Please see the buildman README, or run 'buildman -H'
4348 See also "U-Boot Porting Guide" below.
4351 Monitor Commands - Overview:
4352 ============================
4354 go - start application at address 'addr'
4355 run - run commands in an environment variable
4356 bootm - boot application image from memory
4357 bootp - boot image via network using BootP/TFTP protocol
4358 bootz - boot zImage from memory
4359 tftpboot- boot image via network using TFTP protocol
4360 and env variables "ipaddr" and "serverip"
4361 (and eventually "gatewayip")
4362 tftpput - upload a file via network using TFTP protocol
4363 rarpboot- boot image via network using RARP/TFTP protocol
4364 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4365 loads - load S-Record file over serial line
4366 loadb - load binary file over serial line (kermit mode)
4368 mm - memory modify (auto-incrementing)
4369 nm - memory modify (constant address)
4370 mw - memory write (fill)
4372 cmp - memory compare
4373 crc32 - checksum calculation
4374 i2c - I2C sub-system
4375 sspi - SPI utility commands
4376 base - print or set address offset
4377 printenv- print environment variables
4378 setenv - set environment variables
4379 saveenv - save environment variables to persistent storage
4380 protect - enable or disable FLASH write protection
4381 erase - erase FLASH memory
4382 flinfo - print FLASH memory information
4383 nand - NAND memory operations (see doc/README.nand)
4384 bdinfo - print Board Info structure
4385 iminfo - print header information for application image
4386 coninfo - print console devices and informations
4387 ide - IDE sub-system
4388 loop - infinite loop on address range
4389 loopw - infinite write loop on address range
4390 mtest - simple RAM test
4391 icache - enable or disable instruction cache
4392 dcache - enable or disable data cache
4393 reset - Perform RESET of the CPU
4394 echo - echo args to console
4395 version - print monitor version
4396 help - print online help
4397 ? - alias for 'help'
4400 Monitor Commands - Detailed Description:
4401 ========================================
4405 For now: just type "help <command>".
4408 Environment Variables:
4409 ======================
4411 U-Boot supports user configuration using Environment Variables which
4412 can be made persistent by saving to Flash memory.
4414 Environment Variables are set using "setenv", printed using
4415 "printenv", and saved to Flash using "saveenv". Using "setenv"
4416 without a value can be used to delete a variable from the
4417 environment. As long as you don't save the environment you are
4418 working with an in-memory copy. In case the Flash area containing the
4419 environment is erased by accident, a default environment is provided.
4421 Some configuration options can be set using Environment Variables.
4423 List of environment variables (most likely not complete):
4425 baudrate - see CONFIG_BAUDRATE
4427 bootdelay - see CONFIG_BOOTDELAY
4429 bootcmd - see CONFIG_BOOTCOMMAND
4431 bootargs - Boot arguments when booting an RTOS image
4433 bootfile - Name of the image to load with TFTP
4435 bootm_low - Memory range available for image processing in the bootm
4436 command can be restricted. This variable is given as
4437 a hexadecimal number and defines lowest address allowed
4438 for use by the bootm command. See also "bootm_size"
4439 environment variable. Address defined by "bootm_low" is
4440 also the base of the initial memory mapping for the Linux
4441 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4444 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4445 This variable is given as a hexadecimal number and it
4446 defines the size of the memory region starting at base
4447 address bootm_low that is accessible by the Linux kernel
4448 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4449 as the default value if it is defined, and bootm_size is
4452 bootm_size - Memory range available for image processing in the bootm
4453 command can be restricted. This variable is given as
4454 a hexadecimal number and defines the size of the region
4455 allowed for use by the bootm command. See also "bootm_low"
4456 environment variable.
4458 updatefile - Location of the software update file on a TFTP server, used
4459 by the automatic software update feature. Please refer to
4460 documentation in doc/README.update for more details.
4462 autoload - if set to "no" (any string beginning with 'n'),
4463 "bootp" will just load perform a lookup of the
4464 configuration from the BOOTP server, but not try to
4465 load any image using TFTP
4467 autostart - if set to "yes", an image loaded using the "bootp",
4468 "rarpboot", "tftpboot" or "diskboot" commands will
4469 be automatically started (by internally calling
4472 If set to "no", a standalone image passed to the
4473 "bootm" command will be copied to the load address
4474 (and eventually uncompressed), but NOT be started.
4475 This can be used to load and uncompress arbitrary
4478 fdt_high - if set this restricts the maximum address that the
4479 flattened device tree will be copied into upon boot.
4480 For example, if you have a system with 1 GB memory
4481 at physical address 0x10000000, while Linux kernel
4482 only recognizes the first 704 MB as low memory, you
4483 may need to set fdt_high as 0x3C000000 to have the
4484 device tree blob be copied to the maximum address
4485 of the 704 MB low memory, so that Linux kernel can
4486 access it during the boot procedure.
4488 If this is set to the special value 0xFFFFFFFF then
4489 the fdt will not be copied at all on boot. For this
4490 to work it must reside in writable memory, have
4491 sufficient padding on the end of it for u-boot to
4492 add the information it needs into it, and the memory
4493 must be accessible by the kernel.
4495 fdtcontroladdr- if set this is the address of the control flattened
4496 device tree used by U-Boot when CONFIG_OF_CONTROL is
4499 i2cfast - (PPC405GP|PPC405EP only)
4500 if set to 'y' configures Linux I2C driver for fast
4501 mode (400kHZ). This environment variable is used in
4502 initialization code. So, for changes to be effective
4503 it must be saved and board must be reset.
4505 initrd_high - restrict positioning of initrd images:
4506 If this variable is not set, initrd images will be
4507 copied to the highest possible address in RAM; this
4508 is usually what you want since it allows for
4509 maximum initrd size. If for some reason you want to
4510 make sure that the initrd image is loaded below the
4511 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4512 variable to a value of "no" or "off" or "0".
4513 Alternatively, you can set it to a maximum upper
4514 address to use (U-Boot will still check that it
4515 does not overwrite the U-Boot stack and data).
4517 For instance, when you have a system with 16 MB
4518 RAM, and want to reserve 4 MB from use by Linux,
4519 you can do this by adding "mem=12M" to the value of
4520 the "bootargs" variable. However, now you must make
4521 sure that the initrd image is placed in the first
4522 12 MB as well - this can be done with
4524 setenv initrd_high 00c00000
4526 If you set initrd_high to 0xFFFFFFFF, this is an
4527 indication to U-Boot that all addresses are legal
4528 for the Linux kernel, including addresses in flash
4529 memory. In this case U-Boot will NOT COPY the
4530 ramdisk at all. This may be useful to reduce the
4531 boot time on your system, but requires that this
4532 feature is supported by your Linux kernel.
4534 ipaddr - IP address; needed for tftpboot command
4536 loadaddr - Default load address for commands like "bootp",
4537 "rarpboot", "tftpboot", "loadb" or "diskboot"
4539 loads_echo - see CONFIG_LOADS_ECHO
4541 serverip - TFTP server IP address; needed for tftpboot command
4543 bootretry - see CONFIG_BOOT_RETRY_TIME
4545 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4547 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4549 ethprime - controls which interface is used first.
4551 ethact - controls which interface is currently active.
4552 For example you can do the following
4554 => setenv ethact FEC
4555 => ping 192.168.0.1 # traffic sent on FEC
4556 => setenv ethact SCC
4557 => ping 10.0.0.1 # traffic sent on SCC
4559 ethrotate - When set to "no" U-Boot does not go through all
4560 available network interfaces.
4561 It just stays at the currently selected interface.
4563 netretry - When set to "no" each network operation will
4564 either succeed or fail without retrying.
4565 When set to "once" the network operation will
4566 fail when all the available network interfaces
4567 are tried once without success.
4568 Useful on scripts which control the retry operation
4571 npe_ucode - set load address for the NPE microcode
4573 silent_linux - If set then Linux will be told to boot silently, by
4574 changing the console to be empty. If "yes" it will be
4575 made silent. If "no" it will not be made silent. If
4576 unset, then it will be made silent if the U-Boot console
4579 tftpsrcp - If this is set, the value is used for TFTP's
4582 tftpdstp - If this is set, the value is used for TFTP's UDP
4583 destination port instead of the Well Know Port 69.
4585 tftpblocksize - Block size to use for TFTP transfers; if not set,
4586 we use the TFTP server's default block size
4588 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4589 seconds, minimum value is 1000 = 1 second). Defines
4590 when a packet is considered to be lost so it has to
4591 be retransmitted. The default is 5000 = 5 seconds.
4592 Lowering this value may make downloads succeed
4593 faster in networks with high packet loss rates or
4594 with unreliable TFTP servers.
4596 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4597 unit, minimum value = 0). Defines how many timeouts
4598 can happen during a single file transfer before that
4599 transfer is aborted. The default is 10, and 0 means
4600 'no timeouts allowed'. Increasing this value may help
4601 downloads succeed with high packet loss rates, or with
4602 unreliable TFTP servers or client hardware.
4604 vlan - When set to a value < 4095 the traffic over
4605 Ethernet is encapsulated/received over 802.1q
4608 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4609 Unsigned value, in milliseconds. If not set, the period will
4610 be either the default (28000), or a value based on
4611 CONFIG_NET_RETRY_COUNT, if defined. This value has
4612 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4614 The following image location variables contain the location of images
4615 used in booting. The "Image" column gives the role of the image and is
4616 not an environment variable name. The other columns are environment
4617 variable names. "File Name" gives the name of the file on a TFTP
4618 server, "RAM Address" gives the location in RAM the image will be
4619 loaded to, and "Flash Location" gives the image's address in NOR
4620 flash or offset in NAND flash.
4622 *Note* - these variables don't have to be defined for all boards, some
4623 boards currently use other variables for these purposes, and some
4624 boards use these variables for other purposes.
4626 Image File Name RAM Address Flash Location
4627 ----- --------- ----------- --------------
4628 u-boot u-boot u-boot_addr_r u-boot_addr
4629 Linux kernel bootfile kernel_addr_r kernel_addr
4630 device tree blob fdtfile fdt_addr_r fdt_addr
4631 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4633 The following environment variables may be used and automatically
4634 updated by the network boot commands ("bootp" and "rarpboot"),
4635 depending the information provided by your boot server:
4637 bootfile - see above
4638 dnsip - IP address of your Domain Name Server
4639 dnsip2 - IP address of your secondary Domain Name Server
4640 gatewayip - IP address of the Gateway (Router) to use
4641 hostname - Target hostname
4643 netmask - Subnet Mask
4644 rootpath - Pathname of the root filesystem on the NFS server
4645 serverip - see above
4648 There are two special Environment Variables:
4650 serial# - contains hardware identification information such
4651 as type string and/or serial number
4652 ethaddr - Ethernet address
4654 These variables can be set only once (usually during manufacturing of
4655 the board). U-Boot refuses to delete or overwrite these variables
4656 once they have been set once.
4659 Further special Environment Variables:
4661 ver - Contains the U-Boot version string as printed
4662 with the "version" command. This variable is
4663 readonly (see CONFIG_VERSION_VARIABLE).
4666 Please note that changes to some configuration parameters may take
4667 only effect after the next boot (yes, that's just like Windoze :-).
4670 Callback functions for environment variables:
4671 ---------------------------------------------
4673 For some environment variables, the behavior of u-boot needs to change
4674 when their values are changed. This functionality allows functions to
4675 be associated with arbitrary variables. On creation, overwrite, or
4676 deletion, the callback will provide the opportunity for some side
4677 effect to happen or for the change to be rejected.
4679 The callbacks are named and associated with a function using the
4680 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4682 These callbacks are associated with variables in one of two ways. The
4683 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4684 in the board configuration to a string that defines a list of
4685 associations. The list must be in the following format:
4687 entry = variable_name[:callback_name]
4690 If the callback name is not specified, then the callback is deleted.
4691 Spaces are also allowed anywhere in the list.
4693 Callbacks can also be associated by defining the ".callbacks" variable
4694 with the same list format above. Any association in ".callbacks" will
4695 override any association in the static list. You can define
4696 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4697 ".callbacks" environment variable in the default or embedded environment.
4699 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4700 regular expression. This allows multiple variables to be connected to
4701 the same callback without explicitly listing them all out.
4704 Command Line Parsing:
4705 =====================
4707 There are two different command line parsers available with U-Boot:
4708 the old "simple" one, and the much more powerful "hush" shell:
4710 Old, simple command line parser:
4711 --------------------------------
4713 - supports environment variables (through setenv / saveenv commands)
4714 - several commands on one line, separated by ';'
4715 - variable substitution using "... ${name} ..." syntax
4716 - special characters ('$', ';') can be escaped by prefixing with '\',
4718 setenv bootcmd bootm \${address}
4719 - You can also escape text by enclosing in single apostrophes, for example:
4720 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4725 - similar to Bourne shell, with control structures like
4726 if...then...else...fi, for...do...done; while...do...done,
4727 until...do...done, ...
4728 - supports environment ("global") variables (through setenv / saveenv
4729 commands) and local shell variables (through standard shell syntax
4730 "name=value"); only environment variables can be used with "run"
4736 (1) If a command line (or an environment variable executed by a "run"
4737 command) contains several commands separated by semicolon, and
4738 one of these commands fails, then the remaining commands will be
4741 (2) If you execute several variables with one call to run (i. e.
4742 calling run with a list of variables as arguments), any failing
4743 command will cause "run" to terminate, i. e. the remaining
4744 variables are not executed.
4746 Note for Redundant Ethernet Interfaces:
4747 =======================================
4749 Some boards come with redundant Ethernet interfaces; U-Boot supports
4750 such configurations and is capable of automatic selection of a
4751 "working" interface when needed. MAC assignment works as follows:
4753 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4754 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4755 "eth1addr" (=>eth1), "eth2addr", ...
4757 If the network interface stores some valid MAC address (for instance
4758 in SROM), this is used as default address if there is NO correspon-
4759 ding setting in the environment; if the corresponding environment
4760 variable is set, this overrides the settings in the card; that means:
4762 o If the SROM has a valid MAC address, and there is no address in the
4763 environment, the SROM's address is used.
4765 o If there is no valid address in the SROM, and a definition in the
4766 environment exists, then the value from the environment variable is
4769 o If both the SROM and the environment contain a MAC address, and
4770 both addresses are the same, this MAC address is used.
4772 o If both the SROM and the environment contain a MAC address, and the
4773 addresses differ, the value from the environment is used and a
4776 o If neither SROM nor the environment contain a MAC address, an error
4777 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4778 a random, locally-assigned MAC is used.
4780 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4781 will be programmed into hardware as part of the initialization process. This
4782 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4783 The naming convention is as follows:
4784 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4789 U-Boot is capable of booting (and performing other auxiliary operations on)
4790 images in two formats:
4792 New uImage format (FIT)
4793 -----------------------
4795 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4796 to Flattened Device Tree). It allows the use of images with multiple
4797 components (several kernels, ramdisks, etc.), with contents protected by
4798 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4804 Old image format is based on binary files which can be basically anything,
4805 preceded by a special header; see the definitions in include/image.h for
4806 details; basically, the header defines the following image properties:
4808 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4809 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4810 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4811 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4813 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4814 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4815 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4816 * Compression Type (uncompressed, gzip, bzip2)
4822 The header is marked by a special Magic Number, and both the header
4823 and the data portions of the image are secured against corruption by
4830 Although U-Boot should support any OS or standalone application
4831 easily, the main focus has always been on Linux during the design of
4834 U-Boot includes many features that so far have been part of some
4835 special "boot loader" code within the Linux kernel. Also, any
4836 "initrd" images to be used are no longer part of one big Linux image;
4837 instead, kernel and "initrd" are separate images. This implementation
4838 serves several purposes:
4840 - the same features can be used for other OS or standalone
4841 applications (for instance: using compressed images to reduce the
4842 Flash memory footprint)
4844 - it becomes much easier to port new Linux kernel versions because
4845 lots of low-level, hardware dependent stuff are done by U-Boot
4847 - the same Linux kernel image can now be used with different "initrd"
4848 images; of course this also means that different kernel images can
4849 be run with the same "initrd". This makes testing easier (you don't
4850 have to build a new "zImage.initrd" Linux image when you just
4851 change a file in your "initrd"). Also, a field-upgrade of the
4852 software is easier now.
4858 Porting Linux to U-Boot based systems:
4859 ---------------------------------------
4861 U-Boot cannot save you from doing all the necessary modifications to
4862 configure the Linux device drivers for use with your target hardware
4863 (no, we don't intend to provide a full virtual machine interface to
4866 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4868 Just make sure your machine specific header file (for instance
4869 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4870 Information structure as we define in include/asm-<arch>/u-boot.h,
4871 and make sure that your definition of IMAP_ADDR uses the same value
4872 as your U-Boot configuration in CONFIG_SYS_IMMR.
4874 Note that U-Boot now has a driver model, a unified model for drivers.
4875 If you are adding a new driver, plumb it into driver model. If there
4876 is no uclass available, you are encouraged to create one. See
4880 Configuring the Linux kernel:
4881 -----------------------------
4883 No specific requirements for U-Boot. Make sure you have some root
4884 device (initial ramdisk, NFS) for your target system.
4887 Building a Linux Image:
4888 -----------------------
4890 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4891 not used. If you use recent kernel source, a new build target
4892 "uImage" will exist which automatically builds an image usable by
4893 U-Boot. Most older kernels also have support for a "pImage" target,
4894 which was introduced for our predecessor project PPCBoot and uses a
4895 100% compatible format.
4899 make TQM850L_defconfig
4904 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4905 encapsulate a compressed Linux kernel image with header information,
4906 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4908 * build a standard "vmlinux" kernel image (in ELF binary format):
4910 * convert the kernel into a raw binary image:
4912 ${CROSS_COMPILE}-objcopy -O binary \
4913 -R .note -R .comment \
4914 -S vmlinux linux.bin
4916 * compress the binary image:
4920 * package compressed binary image for U-Boot:
4922 mkimage -A ppc -O linux -T kernel -C gzip \
4923 -a 0 -e 0 -n "Linux Kernel Image" \
4924 -d linux.bin.gz uImage
4927 The "mkimage" tool can also be used to create ramdisk images for use
4928 with U-Boot, either separated from the Linux kernel image, or
4929 combined into one file. "mkimage" encapsulates the images with a 64
4930 byte header containing information about target architecture,
4931 operating system, image type, compression method, entry points, time
4932 stamp, CRC32 checksums, etc.
4934 "mkimage" can be called in two ways: to verify existing images and
4935 print the header information, or to build new images.
4937 In the first form (with "-l" option) mkimage lists the information
4938 contained in the header of an existing U-Boot image; this includes
4939 checksum verification:
4941 tools/mkimage -l image
4942 -l ==> list image header information
4944 The second form (with "-d" option) is used to build a U-Boot image
4945 from a "data file" which is used as image payload:
4947 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4948 -n name -d data_file image
4949 -A ==> set architecture to 'arch'
4950 -O ==> set operating system to 'os'
4951 -T ==> set image type to 'type'
4952 -C ==> set compression type 'comp'
4953 -a ==> set load address to 'addr' (hex)
4954 -e ==> set entry point to 'ep' (hex)
4955 -n ==> set image name to 'name'
4956 -d ==> use image data from 'datafile'
4958 Right now, all Linux kernels for PowerPC systems use the same load
4959 address (0x00000000), but the entry point address depends on the
4962 - 2.2.x kernels have the entry point at 0x0000000C,
4963 - 2.3.x and later kernels have the entry point at 0x00000000.
4965 So a typical call to build a U-Boot image would read:
4967 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4968 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4969 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4970 > examples/uImage.TQM850L
4971 Image Name: 2.4.4 kernel for TQM850L
4972 Created: Wed Jul 19 02:34:59 2000
4973 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4974 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4975 Load Address: 0x00000000
4976 Entry Point: 0x00000000
4978 To verify the contents of the image (or check for corruption):
4980 -> tools/mkimage -l examples/uImage.TQM850L
4981 Image Name: 2.4.4 kernel for TQM850L
4982 Created: Wed Jul 19 02:34:59 2000
4983 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4984 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4985 Load Address: 0x00000000
4986 Entry Point: 0x00000000
4988 NOTE: for embedded systems where boot time is critical you can trade
4989 speed for memory and install an UNCOMPRESSED image instead: this
4990 needs more space in Flash, but boots much faster since it does not
4991 need to be uncompressed:
4993 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4994 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4995 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4996 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4997 > examples/uImage.TQM850L-uncompressed
4998 Image Name: 2.4.4 kernel for TQM850L
4999 Created: Wed Jul 19 02:34:59 2000
5000 Image Type: PowerPC Linux Kernel Image (uncompressed)
5001 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5002 Load Address: 0x00000000
5003 Entry Point: 0x00000000
5006 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5007 when your kernel is intended to use an initial ramdisk:
5009 -> tools/mkimage -n 'Simple Ramdisk Image' \
5010 > -A ppc -O linux -T ramdisk -C gzip \
5011 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5012 Image Name: Simple Ramdisk Image
5013 Created: Wed Jan 12 14:01:50 2000
5014 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5015 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5016 Load Address: 0x00000000
5017 Entry Point: 0x00000000
5019 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5020 option performs the converse operation of the mkimage's second form (the "-d"
5021 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5024 tools/dumpimage -i image -T type -p position data_file
5025 -i ==> extract from the 'image' a specific 'data_file'
5026 -T ==> set image type to 'type'
5027 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5030 Installing a Linux Image:
5031 -------------------------
5033 To downloading a U-Boot image over the serial (console) interface,
5034 you must convert the image to S-Record format:
5036 objcopy -I binary -O srec examples/image examples/image.srec
5038 The 'objcopy' does not understand the information in the U-Boot
5039 image header, so the resulting S-Record file will be relative to
5040 address 0x00000000. To load it to a given address, you need to
5041 specify the target address as 'offset' parameter with the 'loads'
5044 Example: install the image to address 0x40100000 (which on the
5045 TQM8xxL is in the first Flash bank):
5047 => erase 40100000 401FFFFF
5053 ## Ready for S-Record download ...
5054 ~>examples/image.srec
5055 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5057 15989 15990 15991 15992
5058 [file transfer complete]
5060 ## Start Addr = 0x00000000
5063 You can check the success of the download using the 'iminfo' command;
5064 this includes a checksum verification so you can be sure no data
5065 corruption happened:
5069 ## Checking Image at 40100000 ...
5070 Image Name: 2.2.13 for initrd on TQM850L
5071 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5072 Data Size: 335725 Bytes = 327 kB = 0 MB
5073 Load Address: 00000000
5074 Entry Point: 0000000c
5075 Verifying Checksum ... OK
5081 The "bootm" command is used to boot an application that is stored in
5082 memory (RAM or Flash). In case of a Linux kernel image, the contents
5083 of the "bootargs" environment variable is passed to the kernel as
5084 parameters. You can check and modify this variable using the
5085 "printenv" and "setenv" commands:
5088 => printenv bootargs
5089 bootargs=root=/dev/ram
5091 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5093 => printenv bootargs
5094 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5097 ## Booting Linux kernel at 40020000 ...
5098 Image Name: 2.2.13 for NFS on TQM850L
5099 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5100 Data Size: 381681 Bytes = 372 kB = 0 MB
5101 Load Address: 00000000
5102 Entry Point: 0000000c
5103 Verifying Checksum ... OK
5104 Uncompressing Kernel Image ... OK
5105 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
5106 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5107 time_init: decrementer frequency = 187500000/60
5108 Calibrating delay loop... 49.77 BogoMIPS
5109 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5112 If you want to boot a Linux kernel with initial RAM disk, you pass
5113 the memory addresses of both the kernel and the initrd image (PPBCOOT
5114 format!) to the "bootm" command:
5116 => imi 40100000 40200000
5118 ## Checking Image at 40100000 ...
5119 Image Name: 2.2.13 for initrd on TQM850L
5120 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5121 Data Size: 335725 Bytes = 327 kB = 0 MB
5122 Load Address: 00000000
5123 Entry Point: 0000000c
5124 Verifying Checksum ... OK
5126 ## Checking Image at 40200000 ...
5127 Image Name: Simple Ramdisk Image
5128 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5129 Data Size: 566530 Bytes = 553 kB = 0 MB
5130 Load Address: 00000000
5131 Entry Point: 00000000
5132 Verifying Checksum ... OK
5134 => bootm 40100000 40200000
5135 ## Booting Linux kernel at 40100000 ...
5136 Image Name: 2.2.13 for initrd on TQM850L
5137 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5138 Data Size: 335725 Bytes = 327 kB = 0 MB
5139 Load Address: 00000000
5140 Entry Point: 0000000c
5141 Verifying Checksum ... OK
5142 Uncompressing Kernel Image ... OK
5143 ## Loading RAMDisk Image at 40200000 ...
5144 Image Name: Simple Ramdisk Image
5145 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5146 Data Size: 566530 Bytes = 553 kB = 0 MB
5147 Load Address: 00000000
5148 Entry Point: 00000000
5149 Verifying Checksum ... OK
5150 Loading Ramdisk ... OK
5151 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
5152 Boot arguments: root=/dev/ram
5153 time_init: decrementer frequency = 187500000/60
5154 Calibrating delay loop... 49.77 BogoMIPS
5156 RAMDISK: Compressed image found at block 0
5157 VFS: Mounted root (ext2 filesystem).
5161 Boot Linux and pass a flat device tree:
5164 First, U-Boot must be compiled with the appropriate defines. See the section
5165 titled "Linux Kernel Interface" above for a more in depth explanation. The
5166 following is an example of how to start a kernel and pass an updated
5172 oft=oftrees/mpc8540ads.dtb
5173 => tftp $oftaddr $oft
5174 Speed: 1000, full duplex
5176 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5177 Filename 'oftrees/mpc8540ads.dtb'.
5178 Load address: 0x300000
5181 Bytes transferred = 4106 (100a hex)
5182 => tftp $loadaddr $bootfile
5183 Speed: 1000, full duplex
5185 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5187 Load address: 0x200000
5188 Loading:############
5190 Bytes transferred = 1029407 (fb51f hex)
5195 => bootm $loadaddr - $oftaddr
5196 ## Booting image at 00200000 ...
5197 Image Name: Linux-2.6.17-dirty
5198 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5199 Data Size: 1029343 Bytes = 1005.2 kB
5200 Load Address: 00000000
5201 Entry Point: 00000000
5202 Verifying Checksum ... OK
5203 Uncompressing Kernel Image ... OK
5204 Booting using flat device tree at 0x300000
5205 Using MPC85xx ADS machine description
5206 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5210 More About U-Boot Image Types:
5211 ------------------------------
5213 U-Boot supports the following image types:
5215 "Standalone Programs" are directly runnable in the environment
5216 provided by U-Boot; it is expected that (if they behave
5217 well) you can continue to work in U-Boot after return from
5218 the Standalone Program.
5219 "OS Kernel Images" are usually images of some Embedded OS which
5220 will take over control completely. Usually these programs
5221 will install their own set of exception handlers, device
5222 drivers, set up the MMU, etc. - this means, that you cannot
5223 expect to re-enter U-Boot except by resetting the CPU.
5224 "RAMDisk Images" are more or less just data blocks, and their
5225 parameters (address, size) are passed to an OS kernel that is
5227 "Multi-File Images" contain several images, typically an OS
5228 (Linux) kernel image and one or more data images like
5229 RAMDisks. This construct is useful for instance when you want
5230 to boot over the network using BOOTP etc., where the boot
5231 server provides just a single image file, but you want to get
5232 for instance an OS kernel and a RAMDisk image.
5234 "Multi-File Images" start with a list of image sizes, each
5235 image size (in bytes) specified by an "uint32_t" in network
5236 byte order. This list is terminated by an "(uint32_t)0".
5237 Immediately after the terminating 0 follow the images, one by
5238 one, all aligned on "uint32_t" boundaries (size rounded up to
5239 a multiple of 4 bytes).
5241 "Firmware Images" are binary images containing firmware (like
5242 U-Boot or FPGA images) which usually will be programmed to
5245 "Script files" are command sequences that will be executed by
5246 U-Boot's command interpreter; this feature is especially
5247 useful when you configure U-Boot to use a real shell (hush)
5248 as command interpreter.
5250 Booting the Linux zImage:
5251 -------------------------
5253 On some platforms, it's possible to boot Linux zImage. This is done
5254 using the "bootz" command. The syntax of "bootz" command is the same
5255 as the syntax of "bootm" command.
5257 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5258 kernel with raw initrd images. The syntax is slightly different, the
5259 address of the initrd must be augmented by it's size, in the following
5260 format: "<initrd addres>:<initrd size>".
5266 One of the features of U-Boot is that you can dynamically load and
5267 run "standalone" applications, which can use some resources of
5268 U-Boot like console I/O functions or interrupt services.
5270 Two simple examples are included with the sources:
5275 'examples/hello_world.c' contains a small "Hello World" Demo
5276 application; it is automatically compiled when you build U-Boot.
5277 It's configured to run at address 0x00040004, so you can play with it
5281 ## Ready for S-Record download ...
5282 ~>examples/hello_world.srec
5283 1 2 3 4 5 6 7 8 9 10 11 ...
5284 [file transfer complete]
5286 ## Start Addr = 0x00040004
5288 => go 40004 Hello World! This is a test.
5289 ## Starting application at 0x00040004 ...
5300 Hit any key to exit ...
5302 ## Application terminated, rc = 0x0
5304 Another example, which demonstrates how to register a CPM interrupt
5305 handler with the U-Boot code, can be found in 'examples/timer.c'.
5306 Here, a CPM timer is set up to generate an interrupt every second.
5307 The interrupt service routine is trivial, just printing a '.'
5308 character, but this is just a demo program. The application can be
5309 controlled by the following keys:
5311 ? - print current values og the CPM Timer registers
5312 b - enable interrupts and start timer
5313 e - stop timer and disable interrupts
5314 q - quit application
5317 ## Ready for S-Record download ...
5318 ~>examples/timer.srec
5319 1 2 3 4 5 6 7 8 9 10 11 ...
5320 [file transfer complete]
5322 ## Start Addr = 0x00040004
5325 ## Starting application at 0x00040004 ...
5328 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5331 [q, b, e, ?] Set interval 1000000 us
5334 [q, b, e, ?] ........
5335 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5338 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5341 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5344 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5346 [q, b, e, ?] ...Stopping timer
5348 [q, b, e, ?] ## Application terminated, rc = 0x0
5354 Over time, many people have reported problems when trying to use the
5355 "minicom" terminal emulation program for serial download. I (wd)
5356 consider minicom to be broken, and recommend not to use it. Under
5357 Unix, I recommend to use C-Kermit for general purpose use (and
5358 especially for kermit binary protocol download ("loadb" command), and
5359 use "cu" for S-Record download ("loads" command). See
5360 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5361 for help with kermit.
5364 Nevertheless, if you absolutely want to use it try adding this
5365 configuration to your "File transfer protocols" section:
5367 Name Program Name U/D FullScr IO-Red. Multi
5368 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5369 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5375 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5376 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5378 Building requires a cross environment; it is known to work on
5379 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5380 need gmake since the Makefiles are not compatible with BSD make).
5381 Note that the cross-powerpc package does not install include files;
5382 attempting to build U-Boot will fail because <machine/ansi.h> is
5383 missing. This file has to be installed and patched manually:
5385 # cd /usr/pkg/cross/powerpc-netbsd/include
5387 # ln -s powerpc machine
5388 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5389 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5391 Native builds *don't* work due to incompatibilities between native
5392 and U-Boot include files.
5394 Booting assumes that (the first part of) the image booted is a
5395 stage-2 loader which in turn loads and then invokes the kernel
5396 proper. Loader sources will eventually appear in the NetBSD source
5397 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5398 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5401 Implementation Internals:
5402 =========================
5404 The following is not intended to be a complete description of every
5405 implementation detail. However, it should help to understand the
5406 inner workings of U-Boot and make it easier to port it to custom
5410 Initial Stack, Global Data:
5411 ---------------------------
5413 The implementation of U-Boot is complicated by the fact that U-Boot
5414 starts running out of ROM (flash memory), usually without access to
5415 system RAM (because the memory controller is not initialized yet).
5416 This means that we don't have writable Data or BSS segments, and BSS
5417 is not initialized as zero. To be able to get a C environment working
5418 at all, we have to allocate at least a minimal stack. Implementation
5419 options for this are defined and restricted by the CPU used: Some CPU
5420 models provide on-chip memory (like the IMMR area on MPC8xx and
5421 MPC826x processors), on others (parts of) the data cache can be
5422 locked as (mis-) used as memory, etc.
5424 Chris Hallinan posted a good summary of these issues to the
5425 U-Boot mailing list:
5427 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5428 From: "Chris Hallinan" <clh@net1plus.com>
5429 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5432 Correct me if I'm wrong, folks, but the way I understand it
5433 is this: Using DCACHE as initial RAM for Stack, etc, does not
5434 require any physical RAM backing up the cache. The cleverness
5435 is that the cache is being used as a temporary supply of
5436 necessary storage before the SDRAM controller is setup. It's
5437 beyond the scope of this list to explain the details, but you
5438 can see how this works by studying the cache architecture and
5439 operation in the architecture and processor-specific manuals.
5441 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5442 is another option for the system designer to use as an
5443 initial stack/RAM area prior to SDRAM being available. Either
5444 option should work for you. Using CS 4 should be fine if your
5445 board designers haven't used it for something that would
5446 cause you grief during the initial boot! It is frequently not
5449 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5450 with your processor/board/system design. The default value
5451 you will find in any recent u-boot distribution in
5452 walnut.h should work for you. I'd set it to a value larger
5453 than your SDRAM module. If you have a 64MB SDRAM module, set
5454 it above 400_0000. Just make sure your board has no resources
5455 that are supposed to respond to that address! That code in
5456 start.S has been around a while and should work as is when
5457 you get the config right.
5462 It is essential to remember this, since it has some impact on the C
5463 code for the initialization procedures:
5465 * Initialized global data (data segment) is read-only. Do not attempt
5468 * Do not use any uninitialized global data (or implicitly initialized
5469 as zero data - BSS segment) at all - this is undefined, initiali-
5470 zation is performed later (when relocating to RAM).
5472 * Stack space is very limited. Avoid big data buffers or things like
5475 Having only the stack as writable memory limits means we cannot use
5476 normal global data to share information between the code. But it
5477 turned out that the implementation of U-Boot can be greatly
5478 simplified by making a global data structure (gd_t) available to all
5479 functions. We could pass a pointer to this data as argument to _all_
5480 functions, but this would bloat the code. Instead we use a feature of
5481 the GCC compiler (Global Register Variables) to share the data: we
5482 place a pointer (gd) to the global data into a register which we
5483 reserve for this purpose.
5485 When choosing a register for such a purpose we are restricted by the
5486 relevant (E)ABI specifications for the current architecture, and by
5487 GCC's implementation.
5489 For PowerPC, the following registers have specific use:
5491 R2: reserved for system use
5492 R3-R4: parameter passing and return values
5493 R5-R10: parameter passing
5494 R13: small data area pointer
5498 (U-Boot also uses R12 as internal GOT pointer. r12
5499 is a volatile register so r12 needs to be reset when
5500 going back and forth between asm and C)
5502 ==> U-Boot will use R2 to hold a pointer to the global data
5504 Note: on PPC, we could use a static initializer (since the
5505 address of the global data structure is known at compile time),
5506 but it turned out that reserving a register results in somewhat
5507 smaller code - although the code savings are not that big (on
5508 average for all boards 752 bytes for the whole U-Boot image,
5509 624 text + 127 data).
5511 On ARM, the following registers are used:
5513 R0: function argument word/integer result
5514 R1-R3: function argument word
5515 R9: platform specific
5516 R10: stack limit (used only if stack checking is enabled)
5517 R11: argument (frame) pointer
5518 R12: temporary workspace
5521 R15: program counter
5523 ==> U-Boot will use R9 to hold a pointer to the global data
5525 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5527 On Nios II, the ABI is documented here:
5528 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5530 ==> U-Boot will use gp to hold a pointer to the global data
5532 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5533 to access small data sections, so gp is free.
5535 On NDS32, the following registers are used:
5537 R0-R1: argument/return
5539 R15: temporary register for assembler
5540 R16: trampoline register
5541 R28: frame pointer (FP)
5542 R29: global pointer (GP)
5543 R30: link register (LP)
5544 R31: stack pointer (SP)
5545 PC: program counter (PC)
5547 ==> U-Boot will use R10 to hold a pointer to the global data
5549 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5550 or current versions of GCC may "optimize" the code too much.
5555 U-Boot runs in system state and uses physical addresses, i.e. the
5556 MMU is not used either for address mapping nor for memory protection.
5558 The available memory is mapped to fixed addresses using the memory
5559 controller. In this process, a contiguous block is formed for each
5560 memory type (Flash, SDRAM, SRAM), even when it consists of several
5561 physical memory banks.
5563 U-Boot is installed in the first 128 kB of the first Flash bank (on
5564 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5565 booting and sizing and initializing DRAM, the code relocates itself
5566 to the upper end of DRAM. Immediately below the U-Boot code some
5567 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5568 configuration setting]. Below that, a structure with global Board
5569 Info data is placed, followed by the stack (growing downward).
5571 Additionally, some exception handler code is copied to the low 8 kB
5572 of DRAM (0x00000000 ... 0x00001FFF).
5574 So a typical memory configuration with 16 MB of DRAM could look like
5577 0x0000 0000 Exception Vector code
5580 0x0000 2000 Free for Application Use
5586 0x00FB FF20 Monitor Stack (Growing downward)
5587 0x00FB FFAC Board Info Data and permanent copy of global data
5588 0x00FC 0000 Malloc Arena
5591 0x00FE 0000 RAM Copy of Monitor Code
5592 ... eventually: LCD or video framebuffer
5593 ... eventually: pRAM (Protected RAM - unchanged by reset)
5594 0x00FF FFFF [End of RAM]
5597 System Initialization:
5598 ----------------------
5600 In the reset configuration, U-Boot starts at the reset entry point
5601 (on most PowerPC systems at address 0x00000100). Because of the reset
5602 configuration for CS0# this is a mirror of the on board Flash memory.
5603 To be able to re-map memory U-Boot then jumps to its link address.
5604 To be able to implement the initialization code in C, a (small!)
5605 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5606 which provide such a feature like), or in a locked part of the data
5607 cache. After that, U-Boot initializes the CPU core, the caches and
5610 Next, all (potentially) available memory banks are mapped using a
5611 preliminary mapping. For example, we put them on 512 MB boundaries
5612 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5613 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5614 programmed for SDRAM access. Using the temporary configuration, a
5615 simple memory test is run that determines the size of the SDRAM
5618 When there is more than one SDRAM bank, and the banks are of
5619 different size, the largest is mapped first. For equal size, the first
5620 bank (CS2#) is mapped first. The first mapping is always for address
5621 0x00000000, with any additional banks following immediately to create
5622 contiguous memory starting from 0.
5624 Then, the monitor installs itself at the upper end of the SDRAM area
5625 and allocates memory for use by malloc() and for the global Board
5626 Info data; also, the exception vector code is copied to the low RAM
5627 pages, and the final stack is set up.
5629 Only after this relocation will you have a "normal" C environment;
5630 until that you are restricted in several ways, mostly because you are
5631 running from ROM, and because the code will have to be relocated to a
5635 U-Boot Porting Guide:
5636 ----------------------
5638 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5642 int main(int argc, char *argv[])
5644 sighandler_t no_more_time;
5646 signal(SIGALRM, no_more_time);
5647 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5649 if (available_money > available_manpower) {
5650 Pay consultant to port U-Boot;
5654 Download latest U-Boot source;
5656 Subscribe to u-boot mailing list;
5659 email("Hi, I am new to U-Boot, how do I get started?");
5662 Read the README file in the top level directory;
5663 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5664 Read applicable doc/*.README;
5665 Read the source, Luke;
5666 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5669 if (available_money > toLocalCurrency ($2500))
5672 Add a lot of aggravation and time;
5674 if (a similar board exists) { /* hopefully... */
5675 cp -a board/<similar> board/<myboard>
5676 cp include/configs/<similar>.h include/configs/<myboard>.h
5678 Create your own board support subdirectory;
5679 Create your own board include/configs/<myboard>.h file;
5681 Edit new board/<myboard> files
5682 Edit new include/configs/<myboard>.h
5687 Add / modify source code;
5691 email("Hi, I am having problems...");
5693 Send patch file to the U-Boot email list;
5694 if (reasonable critiques)
5695 Incorporate improvements from email list code review;
5697 Defend code as written;
5703 void no_more_time (int sig)
5712 All contributions to U-Boot should conform to the Linux kernel
5713 coding style; see the file "Documentation/CodingStyle" and the script
5714 "scripts/Lindent" in your Linux kernel source directory.
5716 Source files originating from a different project (for example the
5717 MTD subsystem) are generally exempt from these guidelines and are not
5718 reformatted to ease subsequent migration to newer versions of those
5721 Please note that U-Boot is implemented in C (and to some small parts in
5722 Assembler); no C++ is used, so please do not use C++ style comments (//)
5725 Please also stick to the following formatting rules:
5726 - remove any trailing white space
5727 - use TAB characters for indentation and vertical alignment, not spaces
5728 - make sure NOT to use DOS '\r\n' line feeds
5729 - do not add more than 2 consecutive empty lines to source files
5730 - do not add trailing empty lines to source files
5732 Submissions which do not conform to the standards may be returned
5733 with a request to reformat the changes.
5739 Since the number of patches for U-Boot is growing, we need to
5740 establish some rules. Submissions which do not conform to these rules
5741 may be rejected, even when they contain important and valuable stuff.
5743 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5745 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5746 see http://lists.denx.de/mailman/listinfo/u-boot
5748 When you send a patch, please include the following information with
5751 * For bug fixes: a description of the bug and how your patch fixes
5752 this bug. Please try to include a way of demonstrating that the
5753 patch actually fixes something.
5755 * For new features: a description of the feature and your
5758 * A CHANGELOG entry as plaintext (separate from the patch)
5760 * For major contributions, add a MAINTAINERS file with your
5761 information and associated file and directory references.
5763 * When you add support for a new board, don't forget to add a
5764 maintainer e-mail address to the boards.cfg file, too.
5766 * If your patch adds new configuration options, don't forget to
5767 document these in the README file.
5769 * The patch itself. If you are using git (which is *strongly*
5770 recommended) you can easily generate the patch using the
5771 "git format-patch". If you then use "git send-email" to send it to
5772 the U-Boot mailing list, you will avoid most of the common problems
5773 with some other mail clients.
5775 If you cannot use git, use "diff -purN OLD NEW". If your version of
5776 diff does not support these options, then get the latest version of
5779 The current directory when running this command shall be the parent
5780 directory of the U-Boot source tree (i. e. please make sure that
5781 your patch includes sufficient directory information for the
5784 We prefer patches as plain text. MIME attachments are discouraged,
5785 and compressed attachments must not be used.
5787 * If one logical set of modifications affects or creates several
5788 files, all these changes shall be submitted in a SINGLE patch file.
5790 * Changesets that contain different, unrelated modifications shall be
5791 submitted as SEPARATE patches, one patch per changeset.
5796 * Before sending the patch, run the buildman script on your patched
5797 source tree and make sure that no errors or warnings are reported
5798 for any of the boards.
5800 * Keep your modifications to the necessary minimum: A patch
5801 containing several unrelated changes or arbitrary reformats will be
5802 returned with a request to re-formatting / split it.
5804 * If you modify existing code, make sure that your new code does not
5805 add to the memory footprint of the code ;-) Small is beautiful!
5806 When adding new features, these should compile conditionally only
5807 (using #ifdef), and the resulting code with the new feature
5808 disabled must not need more memory than the old code without your
5811 * Remember that there is a size limit of 100 kB per message on the
5812 u-boot mailing list. Bigger patches will be moderated. If they are
5813 reasonable and not too big, they will be acknowledged. But patches
5814 bigger than the size limit should be avoided.
projects / u-boot / blob