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_CPU - The proper name of the cpus node (only required for
612 MPC512X and MPC5xxx based boards).
613 OF_SOC - The proper name of the soc node (only required for
614 MPC512X and MPC5xxx based boards).
615 OF_TBCLK - The timebase frequency.
616 OF_STDOUT_PATH - The path to the console device
618 boards with QUICC Engines require OF_QE to set UCC MAC
621 CONFIG_OF_BOARD_SETUP
623 Board code has addition modification that it wants to make
624 to the flat device tree before handing it off to the kernel
626 CONFIG_OF_SYSTEM_SETUP
628 Other code has addition modification that it wants to make
629 to the flat device tree before handing it off to the kernel.
630 This causes ft_system_setup() to be called before booting
635 U-Boot can detect if an IDE device is present or not.
636 If not, and this new config option is activated, U-Boot
637 removes the ATA node from the DTS before booting Linux,
638 so the Linux IDE driver does not probe the device and
639 crash. This is needed for buggy hardware (uc101) where
640 no pull down resistor is connected to the signal IDE5V_DD7.
642 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
644 This setting is mandatory for all boards that have only one
645 machine type and must be used to specify the machine type
646 number as it appears in the ARM machine registry
647 (see http://www.arm.linux.org.uk/developer/machines/).
648 Only boards that have multiple machine types supported
649 in a single configuration file and the machine type is
650 runtime discoverable, do not have to use this setting.
652 - vxWorks boot parameters:
654 bootvx constructs a valid bootline using the following
655 environments variables: bootdev, bootfile, ipaddr, netmask,
656 serverip, gatewayip, hostname, othbootargs.
657 It loads the vxWorks image pointed bootfile.
659 Note: If a "bootargs" environment is defined, it will overwride
660 the defaults discussed just above.
662 - Cache Configuration:
663 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
664 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
665 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
667 - Cache Configuration for ARM:
668 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
670 CONFIG_SYS_PL310_BASE - Physical base address of PL310
671 controller register space
676 Define this if you want support for Amba PrimeCell PL010 UARTs.
680 Define this if you want support for Amba PrimeCell PL011 UARTs.
684 If you have Amba PrimeCell PL011 UARTs, set this variable to
685 the clock speed of the UARTs.
689 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
690 define this to a list of base addresses for each (supported)
691 port. See e.g. include/configs/versatile.h
693 CONFIG_SERIAL_HW_FLOW_CONTROL
695 Define this variable to enable hw flow control in serial driver.
696 Current user of this option is drivers/serial/nsl16550.c driver
699 CONFIG_BAUDRATE - in bps
700 Select one of the baudrates listed in
701 CONFIG_SYS_BAUDRATE_TABLE, see below.
705 Only needed when CONFIG_BOOTDELAY is enabled;
706 define a command string that is automatically executed
707 when no character is read on the console interface
708 within "Boot Delay" after reset.
711 This can be used to pass arguments to the bootm
712 command. The value of CONFIG_BOOTARGS goes into the
713 environment value "bootargs".
715 CONFIG_RAMBOOT and CONFIG_NFSBOOT
716 The value of these goes into the environment as
717 "ramboot" and "nfsboot" respectively, and can be used
718 as a convenience, when switching between booting from
722 CONFIG_BOOTCOUNT_LIMIT
723 Implements a mechanism for detecting a repeating reboot
725 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
728 If no softreset save registers are found on the hardware
729 "bootcount" is stored in the environment. To prevent a
730 saveenv on all reboots, the environment variable
731 "upgrade_available" is used. If "upgrade_available" is
732 0, "bootcount" is always 0, if "upgrade_available" is
733 1 "bootcount" is incremented in the environment.
734 So the Userspace Applikation must set the "upgrade_available"
735 and "bootcount" variable to 0, if a boot was successfully.
740 When this option is #defined, the existence of the
741 environment variable "preboot" will be checked
742 immediately before starting the CONFIG_BOOTDELAY
743 countdown and/or running the auto-boot command resp.
744 entering interactive mode.
746 This feature is especially useful when "preboot" is
747 automatically generated or modified. For an example
748 see the LWMON board specific code: here "preboot" is
749 modified when the user holds down a certain
750 combination of keys on the (special) keyboard when
753 - Serial Download Echo Mode:
755 If defined to 1, all characters received during a
756 serial download (using the "loads" command) are
757 echoed back. This might be needed by some terminal
758 emulations (like "cu"), but may as well just take
759 time on others. This setting #define's the initial
760 value of the "loads_echo" environment variable.
762 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
764 Select one of the baudrates listed in
765 CONFIG_SYS_BAUDRATE_TABLE, see below.
768 Monitor commands can be included or excluded
769 from the build by using the #include files
770 <config_cmd_all.h> and #undef'ing unwanted
771 commands, or adding #define's for wanted commands.
773 The default command configuration includes all commands
774 except those marked below with a "*".
776 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
777 CONFIG_CMD_ASKENV * ask for env variable
778 CONFIG_CMD_BDI bdinfo
779 CONFIG_CMD_BOOTD bootd
780 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
781 CONFIG_CMD_CACHE * icache, dcache
782 CONFIG_CMD_CONSOLE coninfo
783 CONFIG_CMD_DHCP * DHCP support
784 CONFIG_CMD_DIAG * Diagnostics
785 CONFIG_CMD_ECHO echo arguments
786 CONFIG_CMD_EDITENV edit env variable
787 CONFIG_CMD_ELF * bootelf, bootvx
788 CONFIG_CMD_ENV_EXISTS * check existence of env variable
789 CONFIG_CMD_EXPORTENV * export the environment
790 CONFIG_CMD_EXT2 * ext2 command support
791 CONFIG_CMD_EXT4 * ext4 command support
792 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
793 that work for multiple fs types
794 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
795 CONFIG_CMD_SAVEENV saveenv
796 CONFIG_CMD_FLASH flinfo, erase, protect
797 CONFIG_CMD_FPGA FPGA device initialization support
798 CONFIG_CMD_GO * the 'go' command (exec code)
799 CONFIG_CMD_GREPENV * search environment
800 CONFIG_CMD_I2C * I2C serial bus support
801 CONFIG_CMD_IMI iminfo
802 CONFIG_CMD_IMLS List all images found in NOR flash
803 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
804 CONFIG_CMD_IMPORTENV * import an environment
805 CONFIG_CMD_INI * import data from an ini file into the env
806 CONFIG_CMD_ITEST Integer/string test of 2 values
807 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
808 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
810 CONFIG_CMD_LOADB loadb
811 CONFIG_CMD_LOADS loads
812 CONFIG_CMD_MD5SUM * print md5 message digest
813 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
814 CONFIG_CMD_MEMINFO * Display detailed memory information
815 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
817 CONFIG_CMD_MEMTEST * mtest
818 CONFIG_CMD_MISC Misc functions like sleep etc
819 CONFIG_CMD_MMC * MMC memory mapped support
820 CONFIG_CMD_MII * MII utility commands
821 CONFIG_CMD_MTDPARTS * MTD partition support
822 CONFIG_CMD_NAND * NAND support
823 CONFIG_CMD_NET bootp, tftpboot, rarpboot
824 CONFIG_CMD_NFS NFS support
825 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
826 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
827 CONFIG_CMD_PCI * pciinfo
828 CONFIG_CMD_PCMCIA * PCMCIA support
829 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
831 CONFIG_CMD_PORTIO * Port I/O
832 CONFIG_CMD_READ * Read raw data from partition
833 CONFIG_CMD_REGINFO * Register dump
834 CONFIG_CMD_RUN run command in env variable
835 CONFIG_CMD_SANDBOX * sb command to access sandbox features
836 CONFIG_CMD_SAVES * save S record dump
837 CONFIG_SCSI * SCSI Support
838 CONFIG_CMD_SDRAM * print SDRAM configuration information
839 (requires CONFIG_CMD_I2C)
840 CONFIG_CMD_SETGETDCR Support for DCR Register access
842 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
843 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
844 CONFIG_CMD_SOURCE "source" command Support
845 CONFIG_CMD_SPI * SPI serial bus support
846 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
847 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
848 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
849 CONFIG_CMD_TIMER * access to the system tick timer
850 CONFIG_CMD_USB * USB support
851 CONFIG_CMD_CDP * Cisco Discover Protocol support
852 CONFIG_CMD_MFSL * Microblaze FSL support
853 CONFIG_CMD_XIMG Load part of Multi Image
854 CONFIG_CMD_UUID * Generate random UUID or GUID string
856 EXAMPLE: If you want all functions except of network
857 support you can write:
859 #include "config_cmd_all.h"
860 #undef CONFIG_CMD_NET
863 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
865 Note: Don't enable the "icache" and "dcache" commands
866 (configuration option CONFIG_CMD_CACHE) unless you know
867 what you (and your U-Boot users) are doing. Data
868 cache cannot be enabled on systems like the
869 8260 (where accesses to the IMMR region must be
870 uncached), and it cannot be disabled on all other
871 systems where we (mis-) use the data cache to hold an
872 initial stack and some data.
875 XXX - this list needs to get updated!
877 - Removal of commands
878 If no commands are needed to boot, you can disable
879 CONFIG_CMDLINE to remove them. In this case, the command line
880 will not be available, and when U-Boot wants to execute the
881 boot command (on start-up) it will call board_run_command()
882 instead. This can reduce image size significantly for very
883 simple boot procedures.
885 - Regular expression support:
887 If this variable is defined, U-Boot is linked against
888 the SLRE (Super Light Regular Expression) library,
889 which adds regex support to some commands, as for
890 example "env grep" and "setexpr".
894 If this variable is defined, U-Boot will use a device tree
895 to configure its devices, instead of relying on statically
896 compiled #defines in the board file. This option is
897 experimental and only available on a few boards. The device
898 tree is available in the global data as gd->fdt_blob.
900 U-Boot needs to get its device tree from somewhere. This can
901 be done using one of the three options below:
904 If this variable is defined, U-Boot will embed a device tree
905 binary in its image. This device tree file should be in the
906 board directory and called <soc>-<board>.dts. The binary file
907 is then picked up in board_init_f() and made available through
908 the global data structure as gd->blob.
911 If this variable is defined, U-Boot will build a device tree
912 binary. It will be called u-boot.dtb. Architecture-specific
913 code will locate it at run-time. Generally this works by:
915 cat u-boot.bin u-boot.dtb >image.bin
917 and in fact, U-Boot does this for you, creating a file called
918 u-boot-dtb.bin which is useful in the common case. You can
919 still use the individual files if you need something more
923 If this variable is defined, U-Boot will use the device tree
924 provided by the board at runtime instead of embedding one with
925 the image. Only boards defining board_fdt_blob_setup() support
926 this option (see include/fdtdec.h file).
930 If this variable is defined, it enables watchdog
931 support for the SoC. There must be support in the SoC
932 specific code for a watchdog. When supported for a
933 specific SoC is available, then no further board specific
934 code should be needed to use it.
937 When using a watchdog circuitry external to the used
938 SoC, then define this variable and provide board
939 specific code for the "hw_watchdog_reset" function.
941 CONFIG_AT91_HW_WDT_TIMEOUT
942 specify the timeout in seconds. default 2 seconds.
945 CONFIG_VERSION_VARIABLE
946 If this variable is defined, an environment variable
947 named "ver" is created by U-Boot showing the U-Boot
948 version as printed by the "version" command.
949 Any change to this variable will be reverted at the
954 When CONFIG_CMD_DATE is selected, the type of the RTC
955 has to be selected, too. Define exactly one of the
958 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
959 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
960 CONFIG_RTC_MC146818 - use MC146818 RTC
961 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
962 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
963 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
964 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
965 CONFIG_RTC_DS164x - use Dallas DS164x RTC
966 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
967 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
968 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
969 CONFIG_SYS_RV3029_TCR - enable trickle charger on
972 Note that if the RTC uses I2C, then the I2C interface
973 must also be configured. See I2C Support, below.
976 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
978 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
979 chip-ngpio pairs that tell the PCA953X driver the number of
980 pins supported by a particular chip.
982 Note that if the GPIO device uses I2C, then the I2C interface
983 must also be configured. See I2C Support, below.
986 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
987 accesses and can checksum them or write a list of them out
988 to memory. See the 'iotrace' command for details. This is
989 useful for testing device drivers since it can confirm that
990 the driver behaves the same way before and after a code
991 change. Currently this is supported on sandbox and arm. To
992 add support for your architecture, add '#include <iotrace.h>'
993 to the bottom of arch/<arch>/include/asm/io.h and test.
995 Example output from the 'iotrace stats' command is below.
996 Note that if the trace buffer is exhausted, the checksum will
997 still continue to operate.
1000 Start: 10000000 (buffer start address)
1001 Size: 00010000 (buffer size)
1002 Offset: 00000120 (current buffer offset)
1003 Output: 10000120 (start + offset)
1004 Count: 00000018 (number of trace records)
1005 CRC32: 9526fb66 (CRC32 of all trace records)
1007 - Timestamp Support:
1009 When CONFIG_TIMESTAMP is selected, the timestamp
1010 (date and time) of an image is printed by image
1011 commands like bootm or iminfo. This option is
1012 automatically enabled when you select CONFIG_CMD_DATE .
1014 - Partition Labels (disklabels) Supported:
1015 Zero or more of the following:
1016 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1017 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1018 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1019 bootloader. Note 2TB partition limit; see
1021 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1023 If IDE or SCSI support is enabled (CONFIG_IDE or
1024 CONFIG_SCSI) you must configure support for at
1025 least one non-MTD partition type as well.
1028 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1029 board configurations files but used nowhere!
1031 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1032 be performed by calling the function
1033 ide_set_reset(int reset)
1034 which has to be defined in a board specific file
1039 Set this to enable ATAPI support.
1044 Set this to enable support for disks larger than 137GB
1045 Also look at CONFIG_SYS_64BIT_LBA.
1046 Whithout these , LBA48 support uses 32bit variables and will 'only'
1047 support disks up to 2.1TB.
1049 CONFIG_SYS_64BIT_LBA:
1050 When enabled, makes the IDE subsystem use 64bit sector addresses.
1054 At the moment only there is only support for the
1055 SYM53C8XX SCSI controller; define
1056 CONFIG_SCSI_SYM53C8XX to enable it.
1058 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1059 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1060 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1061 maximum numbers of LUNs, SCSI ID's and target
1063 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1065 The environment variable 'scsidevs' is set to the number of
1066 SCSI devices found during the last scan.
1068 - NETWORK Support (PCI):
1070 Support for Intel 8254x/8257x gigabit chips.
1073 Utility code for direct access to the SPI bus on Intel 8257x.
1074 This does not do anything useful unless you set at least one
1075 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1077 CONFIG_E1000_SPI_GENERIC
1078 Allow generic access to the SPI bus on the Intel 8257x, for
1079 example with the "sspi" command.
1082 Management command for E1000 devices. When used on devices
1083 with SPI support you can reprogram the EEPROM from U-Boot.
1086 Support for Intel 82557/82559/82559ER chips.
1087 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1088 write routine for first time initialisation.
1091 Support for Digital 2114x chips.
1092 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1093 modem chip initialisation (KS8761/QS6611).
1096 Support for National dp83815 chips.
1099 Support for National dp8382[01] gigabit chips.
1101 - NETWORK Support (other):
1103 CONFIG_DRIVER_AT91EMAC
1104 Support for AT91RM9200 EMAC.
1107 Define this to use reduced MII inteface
1109 CONFIG_DRIVER_AT91EMAC_QUIET
1110 If this defined, the driver is quiet.
1111 The driver doen't show link status messages.
1113 CONFIG_CALXEDA_XGMAC
1114 Support for the Calxeda XGMAC device
1117 Support for SMSC's LAN91C96 chips.
1119 CONFIG_LAN91C96_USE_32_BIT
1120 Define this to enable 32 bit addressing
1123 Support for SMSC's LAN91C111 chip
1125 CONFIG_SMC91111_BASE
1126 Define this to hold the physical address
1127 of the device (I/O space)
1129 CONFIG_SMC_USE_32_BIT
1130 Define this if data bus is 32 bits
1132 CONFIG_SMC_USE_IOFUNCS
1133 Define this to use i/o functions instead of macros
1134 (some hardware wont work with macros)
1136 CONFIG_DRIVER_TI_EMAC
1137 Support for davinci emac
1139 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1140 Define this if you have more then 3 PHYs.
1143 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1145 CONFIG_FTGMAC100_EGIGA
1146 Define this to use GE link update with gigabit PHY.
1147 Define this if FTGMAC100 is connected to gigabit PHY.
1148 If your system has 10/100 PHY only, it might not occur
1149 wrong behavior. Because PHY usually return timeout or
1150 useless data when polling gigabit status and gigabit
1151 control registers. This behavior won't affect the
1152 correctnessof 10/100 link speed update.
1155 Support for SMSC's LAN911x and LAN921x chips
1158 Define this to hold the physical address
1159 of the device (I/O space)
1161 CONFIG_SMC911X_32_BIT
1162 Define this if data bus is 32 bits
1164 CONFIG_SMC911X_16_BIT
1165 Define this if data bus is 16 bits. If your processor
1166 automatically converts one 32 bit word to two 16 bit
1167 words you may also try CONFIG_SMC911X_32_BIT.
1170 Support for Renesas on-chip Ethernet controller
1172 CONFIG_SH_ETHER_USE_PORT
1173 Define the number of ports to be used
1175 CONFIG_SH_ETHER_PHY_ADDR
1176 Define the ETH PHY's address
1178 CONFIG_SH_ETHER_CACHE_WRITEBACK
1179 If this option is set, the driver enables cache flush.
1183 Support for PWM module on the imx6.
1187 Support TPM devices.
1189 CONFIG_TPM_TIS_INFINEON
1190 Support for Infineon i2c bus TPM devices. Only one device
1191 per system is supported at this time.
1193 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1194 Define the burst count bytes upper limit
1197 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1199 CONFIG_TPM_ST33ZP24_I2C
1200 Support for STMicroelectronics ST33ZP24 I2C devices.
1201 Requires TPM_ST33ZP24 and I2C.
1203 CONFIG_TPM_ST33ZP24_SPI
1204 Support for STMicroelectronics ST33ZP24 SPI devices.
1205 Requires TPM_ST33ZP24 and SPI.
1207 CONFIG_TPM_ATMEL_TWI
1208 Support for Atmel TWI TPM device. Requires I2C support.
1211 Support for generic parallel port TPM devices. Only one device
1212 per system is supported at this time.
1214 CONFIG_TPM_TIS_BASE_ADDRESS
1215 Base address where the generic TPM device is mapped
1216 to. Contemporary x86 systems usually map it at
1220 Add tpm monitor functions.
1221 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1222 provides monitor access to authorized functions.
1225 Define this to enable the TPM support library which provides
1226 functional interfaces to some TPM commands.
1227 Requires support for a TPM device.
1229 CONFIG_TPM_AUTH_SESSIONS
1230 Define this to enable authorized functions in the TPM library.
1231 Requires CONFIG_TPM and CONFIG_SHA1.
1234 At the moment only the UHCI host controller is
1235 supported (PIP405, MIP405, MPC5200); define
1236 CONFIG_USB_UHCI to enable it.
1237 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1238 and define CONFIG_USB_STORAGE to enable the USB
1241 Supported are USB Keyboards and USB Floppy drives
1243 MPC5200 USB requires additional defines:
1245 for 528 MHz Clock: 0x0001bbbb
1249 for differential drivers: 0x00001000
1250 for single ended drivers: 0x00005000
1251 for differential drivers on PSC3: 0x00000100
1252 for single ended drivers on PSC3: 0x00004100
1253 CONFIG_SYS_USB_EVENT_POLL
1254 May be defined to allow interrupt polling
1255 instead of using asynchronous interrupts
1257 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1258 txfilltuning field in the EHCI controller on reset.
1260 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1261 HW module registers.
1264 Define the below if you wish to use the USB console.
1265 Once firmware is rebuilt from a serial console issue the
1266 command "setenv stdin usbtty; setenv stdout usbtty" and
1267 attach your USB cable. The Unix command "dmesg" should print
1268 it has found a new device. The environment variable usbtty
1269 can be set to gserial or cdc_acm to enable your device to
1270 appear to a USB host as a Linux gserial device or a
1271 Common Device Class Abstract Control Model serial device.
1272 If you select usbtty = gserial you should be able to enumerate
1274 # modprobe usbserial vendor=0xVendorID product=0xProductID
1275 else if using cdc_acm, simply setting the environment
1276 variable usbtty to be cdc_acm should suffice. The following
1277 might be defined in YourBoardName.h
1280 Define this to build a UDC device
1283 Define this to have a tty type of device available to
1284 talk to the UDC device
1287 Define this to enable the high speed support for usb
1288 device and usbtty. If this feature is enabled, a routine
1289 int is_usbd_high_speed(void)
1290 also needs to be defined by the driver to dynamically poll
1291 whether the enumeration has succeded at high speed or full
1294 CONFIG_SYS_CONSOLE_IS_IN_ENV
1295 Define this if you want stdin, stdout &/or stderr to
1298 If you have a USB-IF assigned VendorID then you may wish to
1299 define your own vendor specific values either in BoardName.h
1300 or directly in usbd_vendor_info.h. If you don't define
1301 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1302 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1303 should pretend to be a Linux device to it's target host.
1305 CONFIG_USBD_MANUFACTURER
1306 Define this string as the name of your company for
1307 - CONFIG_USBD_MANUFACTURER "my company"
1309 CONFIG_USBD_PRODUCT_NAME
1310 Define this string as the name of your product
1311 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1313 CONFIG_USBD_VENDORID
1314 Define this as your assigned Vendor ID from the USB
1315 Implementors Forum. This *must* be a genuine Vendor ID
1316 to avoid polluting the USB namespace.
1317 - CONFIG_USBD_VENDORID 0xFFFF
1319 CONFIG_USBD_PRODUCTID
1320 Define this as the unique Product ID
1322 - CONFIG_USBD_PRODUCTID 0xFFFF
1324 - ULPI Layer Support:
1325 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1326 the generic ULPI layer. The generic layer accesses the ULPI PHY
1327 via the platform viewport, so you need both the genric layer and
1328 the viewport enabled. Currently only Chipidea/ARC based
1329 viewport is supported.
1330 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1331 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1332 If your ULPI phy needs a different reference clock than the
1333 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1334 the appropriate value in Hz.
1337 The MMC controller on the Intel PXA is supported. To
1338 enable this define CONFIG_MMC. The MMC can be
1339 accessed from the boot prompt by mapping the device
1340 to physical memory similar to flash. Command line is
1341 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1342 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1345 Support for Renesas on-chip MMCIF controller
1347 CONFIG_SH_MMCIF_ADDR
1348 Define the base address of MMCIF registers
1351 Define the clock frequency for MMCIF
1353 CONFIG_SUPPORT_EMMC_BOOT
1354 Enable some additional features of the eMMC boot partitions.
1356 CONFIG_SUPPORT_EMMC_RPMB
1357 Enable the commands for reading, writing and programming the
1358 key for the Replay Protection Memory Block partition in eMMC.
1360 - USB Device Firmware Update (DFU) class support:
1361 CONFIG_USB_FUNCTION_DFU
1362 This enables the USB portion of the DFU USB class
1365 This enables the command "dfu" which is used to have
1366 U-Boot create a DFU class device via USB. This command
1367 requires that the "dfu_alt_info" environment variable be
1368 set and define the alt settings to expose to the host.
1371 This enables support for exposing (e)MMC devices via DFU.
1374 This enables support for exposing NAND devices via DFU.
1377 This enables support for exposing RAM via DFU.
1378 Note: DFU spec refer to non-volatile memory usage, but
1379 allow usages beyond the scope of spec - here RAM usage,
1380 one that would help mostly the developer.
1382 CONFIG_SYS_DFU_DATA_BUF_SIZE
1383 Dfu transfer uses a buffer before writing data to the
1384 raw storage device. Make the size (in bytes) of this buffer
1385 configurable. The size of this buffer is also configurable
1386 through the "dfu_bufsiz" environment variable.
1388 CONFIG_SYS_DFU_MAX_FILE_SIZE
1389 When updating files rather than the raw storage device,
1390 we use a static buffer to copy the file into and then write
1391 the buffer once we've been given the whole file. Define
1392 this to the maximum filesize (in bytes) for the buffer.
1393 Default is 4 MiB if undefined.
1395 DFU_DEFAULT_POLL_TIMEOUT
1396 Poll timeout [ms], is the timeout a device can send to the
1397 host. The host must wait for this timeout before sending
1398 a subsequent DFU_GET_STATUS request to the device.
1400 DFU_MANIFEST_POLL_TIMEOUT
1401 Poll timeout [ms], which the device sends to the host when
1402 entering dfuMANIFEST state. Host waits this timeout, before
1403 sending again an USB request to the device.
1405 - USB Device Android Fastboot support:
1406 CONFIG_USB_FUNCTION_FASTBOOT
1407 This enables the USB part of the fastboot gadget
1410 This enables the command "fastboot" which enables the Android
1411 fastboot mode for the platform's USB device. Fastboot is a USB
1412 protocol for downloading images, flashing and device control
1413 used on Android devices.
1414 See doc/README.android-fastboot for more information.
1416 CONFIG_ANDROID_BOOT_IMAGE
1417 This enables support for booting images which use the Android
1418 image format header.
1420 CONFIG_FASTBOOT_BUF_ADDR
1421 The fastboot protocol requires a large memory buffer for
1422 downloads. Define this to the starting RAM address to use for
1425 CONFIG_FASTBOOT_BUF_SIZE
1426 The fastboot protocol requires a large memory buffer for
1427 downloads. This buffer should be as large as possible for a
1428 platform. Define this to the size available RAM for fastboot.
1430 CONFIG_FASTBOOT_FLASH
1431 The fastboot protocol includes a "flash" command for writing
1432 the downloaded image to a non-volatile storage device. Define
1433 this to enable the "fastboot flash" command.
1435 CONFIG_FASTBOOT_FLASH_MMC_DEV
1436 The fastboot "flash" command requires additional information
1437 regarding the non-volatile storage device. Define this to
1438 the eMMC device that fastboot should use to store the image.
1440 CONFIG_FASTBOOT_GPT_NAME
1441 The fastboot "flash" command supports writing the downloaded
1442 image to the Protective MBR and the Primary GUID Partition
1443 Table. (Additionally, this downloaded image is post-processed
1444 to generate and write the Backup GUID Partition Table.)
1445 This occurs when the specified "partition name" on the
1446 "fastboot flash" command line matches this value.
1447 The default is "gpt" if undefined.
1449 CONFIG_FASTBOOT_MBR_NAME
1450 The fastboot "flash" command supports writing the downloaded
1452 This occurs when the "partition name" specified on the
1453 "fastboot flash" command line matches this value.
1454 If not defined the default value "mbr" is used.
1456 - Journaling Flash filesystem support:
1458 Define these for a default partition on a NAND device
1460 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1461 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1462 Define these for a default partition on a NOR device
1465 See Kconfig help for available keyboard drivers.
1469 Define this to enable a custom keyboard support.
1470 This simply calls drv_keyboard_init() which must be
1471 defined in your board-specific files. This option is deprecated
1472 and is only used by novena. For new boards, use driver model
1477 Enable the Freescale DIU video driver. Reference boards for
1478 SOCs that have a DIU should define this macro to enable DIU
1479 support, and should also define these other macros:
1484 CONFIG_VIDEO_SW_CURSOR
1485 CONFIG_VGA_AS_SINGLE_DEVICE
1487 CONFIG_VIDEO_BMP_LOGO
1489 The DIU driver will look for the 'video-mode' environment
1490 variable, and if defined, enable the DIU as a console during
1491 boot. See the documentation file doc/README.video for a
1492 description of this variable.
1494 - LCD Support: CONFIG_LCD
1496 Define this to enable LCD support (for output to LCD
1497 display); also select one of the supported displays
1498 by defining one of these:
1502 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1504 CONFIG_NEC_NL6448AC33:
1506 NEC NL6448AC33-18. Active, color, single scan.
1508 CONFIG_NEC_NL6448BC20
1510 NEC NL6448BC20-08. 6.5", 640x480.
1511 Active, color, single scan.
1513 CONFIG_NEC_NL6448BC33_54
1515 NEC NL6448BC33-54. 10.4", 640x480.
1516 Active, color, single scan.
1520 Sharp 320x240. Active, color, single scan.
1521 It isn't 16x9, and I am not sure what it is.
1523 CONFIG_SHARP_LQ64D341
1525 Sharp LQ64D341 display, 640x480.
1526 Active, color, single scan.
1530 HLD1045 display, 640x480.
1531 Active, color, single scan.
1535 Optrex CBL50840-2 NF-FW 99 22 M5
1537 Hitachi LMG6912RPFC-00T
1541 320x240. Black & white.
1543 CONFIG_LCD_ALIGNMENT
1545 Normally the LCD is page-aligned (typically 4KB). If this is
1546 defined then the LCD will be aligned to this value instead.
1547 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1548 here, since it is cheaper to change data cache settings on
1549 a per-section basis.
1554 Sometimes, for example if the display is mounted in portrait
1555 mode or even if it's mounted landscape but rotated by 180degree,
1556 we need to rotate our content of the display relative to the
1557 framebuffer, so that user can read the messages which are
1559 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1560 initialized with a given rotation from "vl_rot" out of
1561 "vidinfo_t" which is provided by the board specific code.
1562 The value for vl_rot is coded as following (matching to
1563 fbcon=rotate:<n> linux-kernel commandline):
1564 0 = no rotation respectively 0 degree
1565 1 = 90 degree rotation
1566 2 = 180 degree rotation
1567 3 = 270 degree rotation
1569 If CONFIG_LCD_ROTATION is not defined, the console will be
1570 initialized with 0degree rotation.
1574 Support drawing of RLE8-compressed bitmaps on the LCD.
1578 Enables an 'i2c edid' command which can read EDID
1579 information over I2C from an attached LCD display.
1581 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1583 If this option is set, the environment is checked for
1584 a variable "splashimage". If found, the usual display
1585 of logo, copyright and system information on the LCD
1586 is suppressed and the BMP image at the address
1587 specified in "splashimage" is loaded instead. The
1588 console is redirected to the "nulldev", too. This
1589 allows for a "silent" boot where a splash screen is
1590 loaded very quickly after power-on.
1592 CONFIG_SPLASHIMAGE_GUARD
1594 If this option is set, then U-Boot will prevent the environment
1595 variable "splashimage" from being set to a problematic address
1596 (see doc/README.displaying-bmps).
1597 This option is useful for targets where, due to alignment
1598 restrictions, an improperly aligned BMP image will cause a data
1599 abort. If you think you will not have problems with unaligned
1600 accesses (for example because your toolchain prevents them)
1601 there is no need to set this option.
1603 CONFIG_SPLASH_SCREEN_ALIGN
1605 If this option is set the splash image can be freely positioned
1606 on the screen. Environment variable "splashpos" specifies the
1607 position as "x,y". If a positive number is given it is used as
1608 number of pixel from left/top. If a negative number is given it
1609 is used as number of pixel from right/bottom. You can also
1610 specify 'm' for centering the image.
1613 setenv splashpos m,m
1614 => image at center of screen
1616 setenv splashpos 30,20
1617 => image at x = 30 and y = 20
1619 setenv splashpos -10,m
1620 => vertically centered image
1621 at x = dspWidth - bmpWidth - 9
1623 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1625 If this option is set, additionally to standard BMP
1626 images, gzipped BMP images can be displayed via the
1627 splashscreen support or the bmp command.
1629 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1631 If this option is set, 8-bit RLE compressed BMP images
1632 can be displayed via the splashscreen support or the
1635 - Compression support:
1638 Enabled by default to support gzip compressed images.
1642 If this option is set, support for bzip2 compressed
1643 images is included. If not, only uncompressed and gzip
1644 compressed images are supported.
1646 NOTE: the bzip2 algorithm requires a lot of RAM, so
1647 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1652 If this option is set, support for LZO compressed images
1658 The address of PHY on MII bus.
1660 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1662 The clock frequency of the MII bus
1666 If this option is set, support for speed/duplex
1667 detection of gigabit PHY is included.
1669 CONFIG_PHY_RESET_DELAY
1671 Some PHY like Intel LXT971A need extra delay after
1672 reset before any MII register access is possible.
1673 For such PHY, set this option to the usec delay
1674 required. (minimum 300usec for LXT971A)
1676 CONFIG_PHY_CMD_DELAY (ppc4xx)
1678 Some PHY like Intel LXT971A need extra delay after
1679 command issued before MII status register can be read
1684 Define a default value for the IP address to use for
1685 the default Ethernet interface, in case this is not
1686 determined through e.g. bootp.
1687 (Environment variable "ipaddr")
1689 - Server IP address:
1692 Defines a default value for the IP address of a TFTP
1693 server to contact when using the "tftboot" command.
1694 (Environment variable "serverip")
1696 CONFIG_KEEP_SERVERADDR
1698 Keeps the server's MAC address, in the env 'serveraddr'
1699 for passing to bootargs (like Linux's netconsole option)
1701 - Gateway IP address:
1704 Defines a default value for the IP address of the
1705 default router where packets to other networks are
1707 (Environment variable "gatewayip")
1712 Defines a default value for the subnet mask (or
1713 routing prefix) which is used to determine if an IP
1714 address belongs to the local subnet or needs to be
1715 forwarded through a router.
1716 (Environment variable "netmask")
1718 - Multicast TFTP Mode:
1721 Defines whether you want to support multicast TFTP as per
1722 rfc-2090; for example to work with atftp. Lets lots of targets
1723 tftp down the same boot image concurrently. Note: the Ethernet
1724 driver in use must provide a function: mcast() to join/leave a
1727 - BOOTP Recovery Mode:
1728 CONFIG_BOOTP_RANDOM_DELAY
1730 If you have many targets in a network that try to
1731 boot using BOOTP, you may want to avoid that all
1732 systems send out BOOTP requests at precisely the same
1733 moment (which would happen for instance at recovery
1734 from a power failure, when all systems will try to
1735 boot, thus flooding the BOOTP server. Defining
1736 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1737 inserted before sending out BOOTP requests. The
1738 following delays are inserted then:
1740 1st BOOTP request: delay 0 ... 1 sec
1741 2nd BOOTP request: delay 0 ... 2 sec
1742 3rd BOOTP request: delay 0 ... 4 sec
1744 BOOTP requests: delay 0 ... 8 sec
1746 CONFIG_BOOTP_ID_CACHE_SIZE
1748 BOOTP packets are uniquely identified using a 32-bit ID. The
1749 server will copy the ID from client requests to responses and
1750 U-Boot will use this to determine if it is the destination of
1751 an incoming response. Some servers will check that addresses
1752 aren't in use before handing them out (usually using an ARP
1753 ping) and therefore take up to a few hundred milliseconds to
1754 respond. Network congestion may also influence the time it
1755 takes for a response to make it back to the client. If that
1756 time is too long, U-Boot will retransmit requests. In order
1757 to allow earlier responses to still be accepted after these
1758 retransmissions, U-Boot's BOOTP client keeps a small cache of
1759 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1760 cache. The default is to keep IDs for up to four outstanding
1761 requests. Increasing this will allow U-Boot to accept offers
1762 from a BOOTP client in networks with unusually high latency.
1764 - DHCP Advanced Options:
1765 You can fine tune the DHCP functionality by defining
1766 CONFIG_BOOTP_* symbols:
1768 CONFIG_BOOTP_SUBNETMASK
1769 CONFIG_BOOTP_GATEWAY
1770 CONFIG_BOOTP_HOSTNAME
1771 CONFIG_BOOTP_NISDOMAIN
1772 CONFIG_BOOTP_BOOTPATH
1773 CONFIG_BOOTP_BOOTFILESIZE
1776 CONFIG_BOOTP_SEND_HOSTNAME
1777 CONFIG_BOOTP_NTPSERVER
1778 CONFIG_BOOTP_TIMEOFFSET
1779 CONFIG_BOOTP_VENDOREX
1780 CONFIG_BOOTP_MAY_FAIL
1782 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1783 environment variable, not the BOOTP server.
1785 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1786 after the configured retry count, the call will fail
1787 instead of starting over. This can be used to fail over
1788 to Link-local IP address configuration if the DHCP server
1791 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1792 serverip from a DHCP server, it is possible that more
1793 than one DNS serverip is offered to the client.
1794 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1795 serverip will be stored in the additional environment
1796 variable "dnsip2". The first DNS serverip is always
1797 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1800 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1801 to do a dynamic update of a DNS server. To do this, they
1802 need the hostname of the DHCP requester.
1803 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1804 of the "hostname" environment variable is passed as
1805 option 12 to the DHCP server.
1807 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1809 A 32bit value in microseconds for a delay between
1810 receiving a "DHCP Offer" and sending the "DHCP Request".
1811 This fixes a problem with certain DHCP servers that don't
1812 respond 100% of the time to a "DHCP request". E.g. On an
1813 AT91RM9200 processor running at 180MHz, this delay needed
1814 to be *at least* 15,000 usec before a Windows Server 2003
1815 DHCP server would reply 100% of the time. I recommend at
1816 least 50,000 usec to be safe. The alternative is to hope
1817 that one of the retries will be successful but note that
1818 the DHCP timeout and retry process takes a longer than
1821 - Link-local IP address negotiation:
1822 Negotiate with other link-local clients on the local network
1823 for an address that doesn't require explicit configuration.
1824 This is especially useful if a DHCP server cannot be guaranteed
1825 to exist in all environments that the device must operate.
1827 See doc/README.link-local for more information.
1830 CONFIG_CDP_DEVICE_ID
1832 The device id used in CDP trigger frames.
1834 CONFIG_CDP_DEVICE_ID_PREFIX
1836 A two character string which is prefixed to the MAC address
1841 A printf format string which contains the ascii name of
1842 the port. Normally is set to "eth%d" which sets
1843 eth0 for the first Ethernet, eth1 for the second etc.
1845 CONFIG_CDP_CAPABILITIES
1847 A 32bit integer which indicates the device capabilities;
1848 0x00000010 for a normal host which does not forwards.
1852 An ascii string containing the version of the software.
1856 An ascii string containing the name of the platform.
1860 A 32bit integer sent on the trigger.
1862 CONFIG_CDP_POWER_CONSUMPTION
1864 A 16bit integer containing the power consumption of the
1865 device in .1 of milliwatts.
1867 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1869 A byte containing the id of the VLAN.
1871 - Status LED: CONFIG_LED_STATUS
1873 Several configurations allow to display the current
1874 status using a LED. For instance, the LED will blink
1875 fast while running U-Boot code, stop blinking as
1876 soon as a reply to a BOOTP request was received, and
1877 start blinking slow once the Linux kernel is running
1878 (supported by a status LED driver in the Linux
1879 kernel). Defining CONFIG_LED_STATUS enables this
1884 CONFIG_LED_STATUS_GPIO
1885 The status LED can be connected to a GPIO pin.
1886 In such cases, the gpio_led driver can be used as a
1887 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1888 to include the gpio_led driver in the U-Boot binary.
1890 CONFIG_GPIO_LED_INVERTED_TABLE
1891 Some GPIO connected LEDs may have inverted polarity in which
1892 case the GPIO high value corresponds to LED off state and
1893 GPIO low value corresponds to LED on state.
1894 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1895 with a list of GPIO LEDs that have inverted polarity.
1897 - CAN Support: CONFIG_CAN_DRIVER
1899 Defining CONFIG_CAN_DRIVER enables CAN driver support
1900 on those systems that support this (optional)
1903 - I2C Support: CONFIG_SYS_I2C
1905 This enable the NEW i2c subsystem, and will allow you to use
1906 i2c commands at the u-boot command line (as long as you set
1907 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1908 based realtime clock chips or other i2c devices. See
1909 common/cmd_i2c.c for a description of the command line
1912 ported i2c driver to the new framework:
1913 - drivers/i2c/soft_i2c.c:
1914 - activate first bus with CONFIG_SYS_I2C_SOFT define
1915 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1916 for defining speed and slave address
1917 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1918 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1919 for defining speed and slave address
1920 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1921 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1922 for defining speed and slave address
1923 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1924 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1925 for defining speed and slave address
1927 - drivers/i2c/fsl_i2c.c:
1928 - activate i2c driver with CONFIG_SYS_I2C_FSL
1929 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1930 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1931 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1933 - If your board supports a second fsl i2c bus, define
1934 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1935 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1936 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1939 - drivers/i2c/tegra_i2c.c:
1940 - activate this driver with CONFIG_SYS_I2C_TEGRA
1941 - This driver adds 4 i2c buses with a fix speed from
1942 100000 and the slave addr 0!
1944 - drivers/i2c/ppc4xx_i2c.c
1945 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1946 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1947 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1949 - drivers/i2c/i2c_mxc.c
1950 - activate this driver with CONFIG_SYS_I2C_MXC
1951 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1952 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1953 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1954 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1955 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1956 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1957 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1958 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1959 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1960 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1961 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1962 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1963 If those defines are not set, default value is 100000
1964 for speed, and 0 for slave.
1966 - drivers/i2c/rcar_i2c.c:
1967 - activate this driver with CONFIG_SYS_I2C_RCAR
1968 - This driver adds 4 i2c buses
1970 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1971 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1972 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1973 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1974 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1975 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1976 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1977 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1978 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1980 - drivers/i2c/sh_i2c.c:
1981 - activate this driver with CONFIG_SYS_I2C_SH
1982 - This driver adds from 2 to 5 i2c buses
1984 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1985 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1986 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1987 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1988 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1989 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1990 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1991 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1992 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1993 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1994 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1996 - drivers/i2c/omap24xx_i2c.c
1997 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1998 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1999 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2000 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2001 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2002 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2003 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2004 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2005 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2006 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2007 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2009 - drivers/i2c/zynq_i2c.c
2010 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2011 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2012 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2014 - drivers/i2c/s3c24x0_i2c.c:
2015 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2016 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2017 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2018 with a fix speed from 100000 and the slave addr 0!
2020 - drivers/i2c/ihs_i2c.c
2021 - activate this driver with CONFIG_SYS_I2C_IHS
2022 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2023 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2024 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2025 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2026 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2027 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2028 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2029 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2030 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2031 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2032 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2033 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2034 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2035 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2036 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2037 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2038 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2039 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2040 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2041 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2042 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2046 CONFIG_SYS_NUM_I2C_BUSES
2047 Hold the number of i2c buses you want to use.
2049 CONFIG_SYS_I2C_DIRECT_BUS
2050 define this, if you don't use i2c muxes on your hardware.
2051 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2054 CONFIG_SYS_I2C_MAX_HOPS
2055 define how many muxes are maximal consecutively connected
2056 on one i2c bus. If you not use i2c muxes, omit this
2059 CONFIG_SYS_I2C_BUSES
2060 hold a list of buses you want to use, only used if
2061 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2062 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2063 CONFIG_SYS_NUM_I2C_BUSES = 9:
2065 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2066 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2067 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2068 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2069 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2070 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2071 {1, {I2C_NULL_HOP}}, \
2072 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2073 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2077 bus 0 on adapter 0 without a mux
2078 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2079 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2080 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2081 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2082 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2083 bus 6 on adapter 1 without a mux
2084 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2085 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2087 If you do not have i2c muxes on your board, omit this define.
2089 - Legacy I2C Support:
2090 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2091 then the following macros need to be defined (examples are
2092 from include/configs/lwmon.h):
2096 (Optional). Any commands necessary to enable the I2C
2097 controller or configure ports.
2099 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2103 The code necessary to make the I2C data line active
2104 (driven). If the data line is open collector, this
2107 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2111 The code necessary to make the I2C data line tri-stated
2112 (inactive). If the data line is open collector, this
2115 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2119 Code that returns true if the I2C data line is high,
2122 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2126 If <bit> is true, sets the I2C data line high. If it
2127 is false, it clears it (low).
2129 eg: #define I2C_SDA(bit) \
2130 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2131 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2135 If <bit> is true, sets the I2C clock line high. If it
2136 is false, it clears it (low).
2138 eg: #define I2C_SCL(bit) \
2139 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2140 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2144 This delay is invoked four times per clock cycle so this
2145 controls the rate of data transfer. The data rate thus
2146 is 1 / (I2C_DELAY * 4). Often defined to be something
2149 #define I2C_DELAY udelay(2)
2151 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2153 If your arch supports the generic GPIO framework (asm/gpio.h),
2154 then you may alternatively define the two GPIOs that are to be
2155 used as SCL / SDA. Any of the previous I2C_xxx macros will
2156 have GPIO-based defaults assigned to them as appropriate.
2158 You should define these to the GPIO value as given directly to
2159 the generic GPIO functions.
2161 CONFIG_SYS_I2C_INIT_BOARD
2163 When a board is reset during an i2c bus transfer
2164 chips might think that the current transfer is still
2165 in progress. On some boards it is possible to access
2166 the i2c SCLK line directly, either by using the
2167 processor pin as a GPIO or by having a second pin
2168 connected to the bus. If this option is defined a
2169 custom i2c_init_board() routine in boards/xxx/board.c
2170 is run early in the boot sequence.
2172 CONFIG_I2C_MULTI_BUS
2174 This option allows the use of multiple I2C buses, each of which
2175 must have a controller. At any point in time, only one bus is
2176 active. To switch to a different bus, use the 'i2c dev' command.
2177 Note that bus numbering is zero-based.
2179 CONFIG_SYS_I2C_NOPROBES
2181 This option specifies a list of I2C devices that will be skipped
2182 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2183 is set, specify a list of bus-device pairs. Otherwise, specify
2184 a 1D array of device addresses
2187 #undef CONFIG_I2C_MULTI_BUS
2188 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2190 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2192 #define CONFIG_I2C_MULTI_BUS
2193 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2195 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2197 CONFIG_SYS_SPD_BUS_NUM
2199 If defined, then this indicates the I2C bus number for DDR SPD.
2200 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2202 CONFIG_SYS_RTC_BUS_NUM
2204 If defined, then this indicates the I2C bus number for the RTC.
2205 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2207 CONFIG_SOFT_I2C_READ_REPEATED_START
2209 defining this will force the i2c_read() function in
2210 the soft_i2c driver to perform an I2C repeated start
2211 between writing the address pointer and reading the
2212 data. If this define is omitted the default behaviour
2213 of doing a stop-start sequence will be used. Most I2C
2214 devices can use either method, but some require one or
2217 - SPI Support: CONFIG_SPI
2219 Enables SPI driver (so far only tested with
2220 SPI EEPROM, also an instance works with Crystal A/D and
2221 D/As on the SACSng board)
2225 Enables the driver for SPI controller on SuperH. Currently
2226 only SH7757 is supported.
2230 Enables a software (bit-bang) SPI driver rather than
2231 using hardware support. This is a general purpose
2232 driver that only requires three general I/O port pins
2233 (two outputs, one input) to function. If this is
2234 defined, the board configuration must define several
2235 SPI configuration items (port pins to use, etc). For
2236 an example, see include/configs/sacsng.h.
2240 Enables a hardware SPI driver for general-purpose reads
2241 and writes. As with CONFIG_SOFT_SPI, the board configuration
2242 must define a list of chip-select function pointers.
2243 Currently supported on some MPC8xxx processors. For an
2244 example, see include/configs/mpc8349emds.h.
2248 Enables the driver for the SPI controllers on i.MX and MXC
2249 SoCs. Currently i.MX31/35/51 are supported.
2251 CONFIG_SYS_SPI_MXC_WAIT
2252 Timeout for waiting until spi transfer completed.
2253 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2255 - FPGA Support: CONFIG_FPGA
2257 Enables FPGA subsystem.
2259 CONFIG_FPGA_<vendor>
2261 Enables support for specific chip vendors.
2264 CONFIG_FPGA_<family>
2266 Enables support for FPGA family.
2267 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2271 Specify the number of FPGA devices to support.
2273 CONFIG_SYS_FPGA_PROG_FEEDBACK
2275 Enable printing of hash marks during FPGA configuration.
2277 CONFIG_SYS_FPGA_CHECK_BUSY
2279 Enable checks on FPGA configuration interface busy
2280 status by the configuration function. This option
2281 will require a board or device specific function to
2286 If defined, a function that provides delays in the FPGA
2287 configuration driver.
2289 CONFIG_SYS_FPGA_CHECK_CTRLC
2290 Allow Control-C to interrupt FPGA configuration
2292 CONFIG_SYS_FPGA_CHECK_ERROR
2294 Check for configuration errors during FPGA bitfile
2295 loading. For example, abort during Virtex II
2296 configuration if the INIT_B line goes low (which
2297 indicated a CRC error).
2299 CONFIG_SYS_FPGA_WAIT_INIT
2301 Maximum time to wait for the INIT_B line to de-assert
2302 after PROB_B has been de-asserted during a Virtex II
2303 FPGA configuration sequence. The default time is 500
2306 CONFIG_SYS_FPGA_WAIT_BUSY
2308 Maximum time to wait for BUSY to de-assert during
2309 Virtex II FPGA configuration. The default is 5 ms.
2311 CONFIG_SYS_FPGA_WAIT_CONFIG
2313 Time to wait after FPGA configuration. The default is
2316 - Configuration Management:
2319 Some SoCs need special image types (e.g. U-Boot binary
2320 with a special header) as build targets. By defining
2321 CONFIG_BUILD_TARGET in the SoC / board header, this
2322 special image will be automatically built upon calling
2327 If defined, this string will be added to the U-Boot
2328 version information (U_BOOT_VERSION)
2330 - Vendor Parameter Protection:
2332 U-Boot considers the values of the environment
2333 variables "serial#" (Board Serial Number) and
2334 "ethaddr" (Ethernet Address) to be parameters that
2335 are set once by the board vendor / manufacturer, and
2336 protects these variables from casual modification by
2337 the user. Once set, these variables are read-only,
2338 and write or delete attempts are rejected. You can
2339 change this behaviour:
2341 If CONFIG_ENV_OVERWRITE is #defined in your config
2342 file, the write protection for vendor parameters is
2343 completely disabled. Anybody can change or delete
2346 Alternatively, if you define _both_ an ethaddr in the
2347 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2348 Ethernet address is installed in the environment,
2349 which can be changed exactly ONCE by the user. [The
2350 serial# is unaffected by this, i. e. it remains
2353 The same can be accomplished in a more flexible way
2354 for any variable by configuring the type of access
2355 to allow for those variables in the ".flags" variable
2356 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2361 Define this variable to enable the reservation of
2362 "protected RAM", i. e. RAM which is not overwritten
2363 by U-Boot. Define CONFIG_PRAM to hold the number of
2364 kB you want to reserve for pRAM. You can overwrite
2365 this default value by defining an environment
2366 variable "pram" to the number of kB you want to
2367 reserve. Note that the board info structure will
2368 still show the full amount of RAM. If pRAM is
2369 reserved, a new environment variable "mem" will
2370 automatically be defined to hold the amount of
2371 remaining RAM in a form that can be passed as boot
2372 argument to Linux, for instance like that:
2374 setenv bootargs ... mem=\${mem}
2377 This way you can tell Linux not to use this memory,
2378 either, which results in a memory region that will
2379 not be affected by reboots.
2381 *WARNING* If your board configuration uses automatic
2382 detection of the RAM size, you must make sure that
2383 this memory test is non-destructive. So far, the
2384 following board configurations are known to be
2387 IVMS8, IVML24, SPD8xx,
2388 HERMES, IP860, RPXlite, LWMON,
2391 - Access to physical memory region (> 4GB)
2392 Some basic support is provided for operations on memory not
2393 normally accessible to U-Boot - e.g. some architectures
2394 support access to more than 4GB of memory on 32-bit
2395 machines using physical address extension or similar.
2396 Define CONFIG_PHYSMEM to access this basic support, which
2397 currently only supports clearing the memory.
2402 Define this variable to stop the system in case of a
2403 fatal error, so that you have to reset it manually.
2404 This is probably NOT a good idea for an embedded
2405 system where you want the system to reboot
2406 automatically as fast as possible, but it may be
2407 useful during development since you can try to debug
2408 the conditions that lead to the situation.
2410 CONFIG_NET_RETRY_COUNT
2412 This variable defines the number of retries for
2413 network operations like ARP, RARP, TFTP, or BOOTP
2414 before giving up the operation. If not defined, a
2415 default value of 5 is used.
2419 Timeout waiting for an ARP reply in milliseconds.
2423 Timeout in milliseconds used in NFS protocol.
2424 If you encounter "ERROR: Cannot umount" in nfs command,
2425 try longer timeout such as
2426 #define CONFIG_NFS_TIMEOUT 10000UL
2428 - Command Interpreter:
2429 CONFIG_AUTO_COMPLETE
2431 Enable auto completion of commands using TAB.
2433 CONFIG_SYS_PROMPT_HUSH_PS2
2435 This defines the secondary prompt string, which is
2436 printed when the command interpreter needs more input
2437 to complete a command. Usually "> ".
2441 In the current implementation, the local variables
2442 space and global environment variables space are
2443 separated. Local variables are those you define by
2444 simply typing `name=value'. To access a local
2445 variable later on, you have write `$name' or
2446 `${name}'; to execute the contents of a variable
2447 directly type `$name' at the command prompt.
2449 Global environment variables are those you use
2450 setenv/printenv to work with. To run a command stored
2451 in such a variable, you need to use the run command,
2452 and you must not use the '$' sign to access them.
2454 To store commands and special characters in a
2455 variable, please use double quotation marks
2456 surrounding the whole text of the variable, instead
2457 of the backslashes before semicolons and special
2460 - Command Line Editing and History:
2461 CONFIG_CMDLINE_EDITING
2463 Enable editing and History functions for interactive
2464 command line input operations
2466 - Command Line PS1/PS2 support:
2467 CONFIG_CMDLINE_PS_SUPPORT
2469 Enable support for changing the command prompt string
2470 at run-time. Only static string is supported so far.
2471 The string is obtained from environment variables PS1
2474 - Default Environment:
2475 CONFIG_EXTRA_ENV_SETTINGS
2477 Define this to contain any number of null terminated
2478 strings (variable = value pairs) that will be part of
2479 the default environment compiled into the boot image.
2481 For example, place something like this in your
2482 board's config file:
2484 #define CONFIG_EXTRA_ENV_SETTINGS \
2488 Warning: This method is based on knowledge about the
2489 internal format how the environment is stored by the
2490 U-Boot code. This is NOT an official, exported
2491 interface! Although it is unlikely that this format
2492 will change soon, there is no guarantee either.
2493 You better know what you are doing here.
2495 Note: overly (ab)use of the default environment is
2496 discouraged. Make sure to check other ways to preset
2497 the environment like the "source" command or the
2500 CONFIG_ENV_VARS_UBOOT_CONFIG
2502 Define this in order to add variables describing the
2503 U-Boot build configuration to the default environment.
2504 These will be named arch, cpu, board, vendor, and soc.
2506 Enabling this option will cause the following to be defined:
2514 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2516 Define this in order to add variables describing certain
2517 run-time determined information about the hardware to the
2518 environment. These will be named board_name, board_rev.
2520 CONFIG_DELAY_ENVIRONMENT
2522 Normally the environment is loaded when the board is
2523 initialised so that it is available to U-Boot. This inhibits
2524 that so that the environment is not available until
2525 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2526 this is instead controlled by the value of
2527 /config/load-environment.
2529 - DataFlash Support:
2530 CONFIG_HAS_DATAFLASH
2532 Defining this option enables DataFlash features and
2533 allows to read/write in Dataflash via the standard
2536 - Serial Flash support
2539 Defining this option enables SPI flash commands
2540 'sf probe/read/write/erase/update'.
2542 Usage requires an initial 'probe' to define the serial
2543 flash parameters, followed by read/write/erase/update
2546 The following defaults may be provided by the platform
2547 to handle the common case when only a single serial
2548 flash is present on the system.
2550 CONFIG_SF_DEFAULT_BUS Bus identifier
2551 CONFIG_SF_DEFAULT_CS Chip-select
2552 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2553 CONFIG_SF_DEFAULT_SPEED in Hz
2557 Define this option to include a destructive SPI flash
2560 CONFIG_SF_DUAL_FLASH Dual flash memories
2562 Define this option to use dual flash support where two flash
2563 memories can be connected with a given cs line.
2564 Currently Xilinx Zynq qspi supports these type of connections.
2566 - SystemACE Support:
2569 Adding this option adds support for Xilinx SystemACE
2570 chips attached via some sort of local bus. The address
2571 of the chip must also be defined in the
2572 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2574 #define CONFIG_SYSTEMACE
2575 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2577 When SystemACE support is added, the "ace" device type
2578 becomes available to the fat commands, i.e. fatls.
2580 - TFTP Fixed UDP Port:
2583 If this is defined, the environment variable tftpsrcp
2584 is used to supply the TFTP UDP source port value.
2585 If tftpsrcp isn't defined, the normal pseudo-random port
2586 number generator is used.
2588 Also, the environment variable tftpdstp is used to supply
2589 the TFTP UDP destination port value. If tftpdstp isn't
2590 defined, the normal port 69 is used.
2592 The purpose for tftpsrcp is to allow a TFTP server to
2593 blindly start the TFTP transfer using the pre-configured
2594 target IP address and UDP port. This has the effect of
2595 "punching through" the (Windows XP) firewall, allowing
2596 the remainder of the TFTP transfer to proceed normally.
2597 A better solution is to properly configure the firewall,
2598 but sometimes that is not allowed.
2600 - bootcount support:
2601 CONFIG_BOOTCOUNT_LIMIT
2603 This enables the bootcounter support, see:
2604 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2607 enable special bootcounter support on at91sam9xe based boards.
2609 enable special bootcounter support on da850 based boards.
2610 CONFIG_BOOTCOUNT_RAM
2611 enable support for the bootcounter in RAM
2612 CONFIG_BOOTCOUNT_I2C
2613 enable support for the bootcounter on an i2c (like RTC) device.
2614 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2615 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2617 CONFIG_BOOTCOUNT_ALEN = address len
2619 - Show boot progress:
2620 CONFIG_SHOW_BOOT_PROGRESS
2622 Defining this option allows to add some board-
2623 specific code (calling a user-provided function
2624 "show_boot_progress(int)") that enables you to show
2625 the system's boot progress on some display (for
2626 example, some LED's) on your board. At the moment,
2627 the following checkpoints are implemented:
2630 Legacy uImage format:
2633 1 common/cmd_bootm.c before attempting to boot an image
2634 -1 common/cmd_bootm.c Image header has bad magic number
2635 2 common/cmd_bootm.c Image header has correct magic number
2636 -2 common/cmd_bootm.c Image header has bad checksum
2637 3 common/cmd_bootm.c Image header has correct checksum
2638 -3 common/cmd_bootm.c Image data has bad checksum
2639 4 common/cmd_bootm.c Image data has correct checksum
2640 -4 common/cmd_bootm.c Image is for unsupported architecture
2641 5 common/cmd_bootm.c Architecture check OK
2642 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2643 6 common/cmd_bootm.c Image Type check OK
2644 -6 common/cmd_bootm.c gunzip uncompression error
2645 -7 common/cmd_bootm.c Unimplemented compression type
2646 7 common/cmd_bootm.c Uncompression OK
2647 8 common/cmd_bootm.c No uncompress/copy overwrite error
2648 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2650 9 common/image.c Start initial ramdisk verification
2651 -10 common/image.c Ramdisk header has bad magic number
2652 -11 common/image.c Ramdisk header has bad checksum
2653 10 common/image.c Ramdisk header is OK
2654 -12 common/image.c Ramdisk data has bad checksum
2655 11 common/image.c Ramdisk data has correct checksum
2656 12 common/image.c Ramdisk verification complete, start loading
2657 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2658 13 common/image.c Start multifile image verification
2659 14 common/image.c No initial ramdisk, no multifile, continue.
2661 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2663 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2664 -31 post/post.c POST test failed, detected by post_output_backlog()
2665 -32 post/post.c POST test failed, detected by post_run_single()
2667 34 common/cmd_doc.c before loading a Image from a DOC device
2668 -35 common/cmd_doc.c Bad usage of "doc" command
2669 35 common/cmd_doc.c correct usage of "doc" command
2670 -36 common/cmd_doc.c No boot device
2671 36 common/cmd_doc.c correct boot device
2672 -37 common/cmd_doc.c Unknown Chip ID on boot device
2673 37 common/cmd_doc.c correct chip ID found, device available
2674 -38 common/cmd_doc.c Read Error on boot device
2675 38 common/cmd_doc.c reading Image header from DOC device OK
2676 -39 common/cmd_doc.c Image header has bad magic number
2677 39 common/cmd_doc.c Image header has correct magic number
2678 -40 common/cmd_doc.c Error reading Image from DOC device
2679 40 common/cmd_doc.c Image header has correct magic number
2680 41 common/cmd_ide.c before loading a Image from a IDE device
2681 -42 common/cmd_ide.c Bad usage of "ide" command
2682 42 common/cmd_ide.c correct usage of "ide" command
2683 -43 common/cmd_ide.c No boot device
2684 43 common/cmd_ide.c boot device found
2685 -44 common/cmd_ide.c Device not available
2686 44 common/cmd_ide.c Device available
2687 -45 common/cmd_ide.c wrong partition selected
2688 45 common/cmd_ide.c partition selected
2689 -46 common/cmd_ide.c Unknown partition table
2690 46 common/cmd_ide.c valid partition table found
2691 -47 common/cmd_ide.c Invalid partition type
2692 47 common/cmd_ide.c correct partition type
2693 -48 common/cmd_ide.c Error reading Image Header on boot device
2694 48 common/cmd_ide.c reading Image Header from IDE device OK
2695 -49 common/cmd_ide.c Image header has bad magic number
2696 49 common/cmd_ide.c Image header has correct magic number
2697 -50 common/cmd_ide.c Image header has bad checksum
2698 50 common/cmd_ide.c Image header has correct checksum
2699 -51 common/cmd_ide.c Error reading Image from IDE device
2700 51 common/cmd_ide.c reading Image from IDE device OK
2701 52 common/cmd_nand.c before loading a Image from a NAND device
2702 -53 common/cmd_nand.c Bad usage of "nand" command
2703 53 common/cmd_nand.c correct usage of "nand" command
2704 -54 common/cmd_nand.c No boot device
2705 54 common/cmd_nand.c boot device found
2706 -55 common/cmd_nand.c Unknown Chip ID on boot device
2707 55 common/cmd_nand.c correct chip ID found, device available
2708 -56 common/cmd_nand.c Error reading Image Header on boot device
2709 56 common/cmd_nand.c reading Image Header from NAND device OK
2710 -57 common/cmd_nand.c Image header has bad magic number
2711 57 common/cmd_nand.c Image header has correct magic number
2712 -58 common/cmd_nand.c Error reading Image from NAND device
2713 58 common/cmd_nand.c reading Image from NAND device OK
2715 -60 common/env_common.c Environment has a bad CRC, using default
2717 64 net/eth.c starting with Ethernet configuration.
2718 -64 net/eth.c no Ethernet found.
2719 65 net/eth.c Ethernet found.
2721 -80 common/cmd_net.c usage wrong
2722 80 common/cmd_net.c before calling net_loop()
2723 -81 common/cmd_net.c some error in net_loop() occurred
2724 81 common/cmd_net.c net_loop() back without error
2725 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2726 82 common/cmd_net.c trying automatic boot
2727 83 common/cmd_net.c running "source" command
2728 -83 common/cmd_net.c some error in automatic boot or "source" command
2729 84 common/cmd_net.c end without errors
2734 100 common/cmd_bootm.c Kernel FIT Image has correct format
2735 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2736 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2737 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2738 102 common/cmd_bootm.c Kernel unit name specified
2739 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2740 103 common/cmd_bootm.c Found configuration node
2741 104 common/cmd_bootm.c Got kernel subimage node offset
2742 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2743 105 common/cmd_bootm.c Kernel subimage hash verification OK
2744 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2745 106 common/cmd_bootm.c Architecture check OK
2746 -106 common/cmd_bootm.c Kernel subimage has wrong type
2747 107 common/cmd_bootm.c Kernel subimage type OK
2748 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2749 108 common/cmd_bootm.c Got kernel subimage data/size
2750 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2751 -109 common/cmd_bootm.c Can't get kernel subimage type
2752 -110 common/cmd_bootm.c Can't get kernel subimage comp
2753 -111 common/cmd_bootm.c Can't get kernel subimage os
2754 -112 common/cmd_bootm.c Can't get kernel subimage load address
2755 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2757 120 common/image.c Start initial ramdisk verification
2758 -120 common/image.c Ramdisk FIT image has incorrect format
2759 121 common/image.c Ramdisk FIT image has correct format
2760 122 common/image.c No ramdisk subimage unit name, using configuration
2761 -122 common/image.c Can't get configuration for ramdisk subimage
2762 123 common/image.c Ramdisk unit name specified
2763 -124 common/image.c Can't get ramdisk subimage node offset
2764 125 common/image.c Got ramdisk subimage node offset
2765 -125 common/image.c Ramdisk subimage hash verification failed
2766 126 common/image.c Ramdisk subimage hash verification OK
2767 -126 common/image.c Ramdisk subimage for unsupported architecture
2768 127 common/image.c Architecture check OK
2769 -127 common/image.c Can't get ramdisk subimage data/size
2770 128 common/image.c Got ramdisk subimage data/size
2771 129 common/image.c Can't get ramdisk load address
2772 -129 common/image.c Got ramdisk load address
2774 -130 common/cmd_doc.c Incorrect FIT image format
2775 131 common/cmd_doc.c FIT image format OK
2777 -140 common/cmd_ide.c Incorrect FIT image format
2778 141 common/cmd_ide.c FIT image format OK
2780 -150 common/cmd_nand.c Incorrect FIT image format
2781 151 common/cmd_nand.c FIT image format OK
2783 - legacy image format:
2784 CONFIG_IMAGE_FORMAT_LEGACY
2785 enables the legacy image format support in U-Boot.
2788 enabled if CONFIG_FIT_SIGNATURE is not defined.
2790 CONFIG_DISABLE_IMAGE_LEGACY
2791 disable the legacy image format
2793 This define is introduced, as the legacy image format is
2794 enabled per default for backward compatibility.
2796 - Standalone program support:
2797 CONFIG_STANDALONE_LOAD_ADDR
2799 This option defines a board specific value for the
2800 address where standalone program gets loaded, thus
2801 overwriting the architecture dependent default
2804 - Frame Buffer Address:
2807 Define CONFIG_FB_ADDR if you want to use specific
2808 address for frame buffer. This is typically the case
2809 when using a graphics controller has separate video
2810 memory. U-Boot will then place the frame buffer at
2811 the given address instead of dynamically reserving it
2812 in system RAM by calling lcd_setmem(), which grabs
2813 the memory for the frame buffer depending on the
2814 configured panel size.
2816 Please see board_init_f function.
2818 - Automatic software updates via TFTP server
2820 CONFIG_UPDATE_TFTP_CNT_MAX
2821 CONFIG_UPDATE_TFTP_MSEC_MAX
2823 These options enable and control the auto-update feature;
2824 for a more detailed description refer to doc/README.update.
2826 - MTD Support (mtdparts command, UBI support)
2829 Adds the MTD device infrastructure from the Linux kernel.
2830 Needed for mtdparts command support.
2832 CONFIG_MTD_PARTITIONS
2834 Adds the MTD partitioning infrastructure from the Linux
2835 kernel. Needed for UBI support.
2840 Adds commands for interacting with MTD partitions formatted
2841 with the UBI flash translation layer
2843 Requires also defining CONFIG_RBTREE
2845 CONFIG_UBI_SILENCE_MSG
2847 Make the verbose messages from UBI stop printing. This leaves
2848 warnings and errors enabled.
2851 CONFIG_MTD_UBI_WL_THRESHOLD
2852 This parameter defines the maximum difference between the highest
2853 erase counter value and the lowest erase counter value of eraseblocks
2854 of UBI devices. When this threshold is exceeded, UBI starts performing
2855 wear leveling by means of moving data from eraseblock with low erase
2856 counter to eraseblocks with high erase counter.
2858 The default value should be OK for SLC NAND flashes, NOR flashes and
2859 other flashes which have eraseblock life-cycle 100000 or more.
2860 However, in case of MLC NAND flashes which typically have eraseblock
2861 life-cycle less than 10000, the threshold should be lessened (e.g.,
2862 to 128 or 256, although it does not have to be power of 2).
2866 CONFIG_MTD_UBI_BEB_LIMIT
2867 This option specifies the maximum bad physical eraseblocks UBI
2868 expects on the MTD device (per 1024 eraseblocks). If the
2869 underlying flash does not admit of bad eraseblocks (e.g. NOR
2870 flash), this value is ignored.
2872 NAND datasheets often specify the minimum and maximum NVM
2873 (Number of Valid Blocks) for the flashes' endurance lifetime.
2874 The maximum expected bad eraseblocks per 1024 eraseblocks
2875 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2876 which gives 20 for most NANDs (MaxNVB is basically the total
2877 count of eraseblocks on the chip).
2879 To put it differently, if this value is 20, UBI will try to
2880 reserve about 1.9% of physical eraseblocks for bad blocks
2881 handling. And that will be 1.9% of eraseblocks on the entire
2882 NAND chip, not just the MTD partition UBI attaches. This means
2883 that if you have, say, a NAND flash chip admits maximum 40 bad
2884 eraseblocks, and it is split on two MTD partitions of the same
2885 size, UBI will reserve 40 eraseblocks when attaching a
2890 CONFIG_MTD_UBI_FASTMAP
2891 Fastmap is a mechanism which allows attaching an UBI device
2892 in nearly constant time. Instead of scanning the whole MTD device it
2893 only has to locate a checkpoint (called fastmap) on the device.
2894 The on-flash fastmap contains all information needed to attach
2895 the device. Using fastmap makes only sense on large devices where
2896 attaching by scanning takes long. UBI will not automatically install
2897 a fastmap on old images, but you can set the UBI parameter
2898 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2899 that fastmap-enabled images are still usable with UBI implementations
2900 without fastmap support. On typical flash devices the whole fastmap
2901 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2903 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2904 Set this parameter to enable fastmap automatically on images
2908 CONFIG_MTD_UBI_FM_DEBUG
2909 Enable UBI fastmap debug
2915 Adds commands for interacting with UBI volumes formatted as
2916 UBIFS. UBIFS is read-only in u-boot.
2918 Requires UBI support as well as CONFIG_LZO
2920 CONFIG_UBIFS_SILENCE_MSG
2922 Make the verbose messages from UBIFS stop printing. This leaves
2923 warnings and errors enabled.
2927 Enable building of SPL globally.
2930 LDSCRIPT for linking the SPL binary.
2932 CONFIG_SPL_MAX_FOOTPRINT
2933 Maximum size in memory allocated to the SPL, BSS included.
2934 When defined, the linker checks that the actual memory
2935 used by SPL from _start to __bss_end does not exceed it.
2936 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2937 must not be both defined at the same time.
2940 Maximum size of the SPL image (text, data, rodata, and
2941 linker lists sections), BSS excluded.
2942 When defined, the linker checks that the actual size does
2945 CONFIG_SPL_TEXT_BASE
2946 TEXT_BASE for linking the SPL binary.
2948 CONFIG_SPL_RELOC_TEXT_BASE
2949 Address to relocate to. If unspecified, this is equal to
2950 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2952 CONFIG_SPL_BSS_START_ADDR
2953 Link address for the BSS within the SPL binary.
2955 CONFIG_SPL_BSS_MAX_SIZE
2956 Maximum size in memory allocated to the SPL BSS.
2957 When defined, the linker checks that the actual memory used
2958 by SPL from __bss_start to __bss_end does not exceed it.
2959 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2960 must not be both defined at the same time.
2963 Adress of the start of the stack SPL will use
2965 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2966 When defined, SPL will panic() if the image it has
2967 loaded does not have a signature.
2968 Defining this is useful when code which loads images
2969 in SPL cannot guarantee that absolutely all read errors
2971 An example is the LPC32XX MLC NAND driver, which will
2972 consider that a completely unreadable NAND block is bad,
2973 and thus should be skipped silently.
2975 CONFIG_SPL_RELOC_STACK
2976 Adress of the start of the stack SPL will use after
2977 relocation. If unspecified, this is equal to
2980 CONFIG_SYS_SPL_MALLOC_START
2981 Starting address of the malloc pool used in SPL.
2982 When this option is set the full malloc is used in SPL and
2983 it is set up by spl_init() and before that, the simple malloc()
2984 can be used if CONFIG_SYS_MALLOC_F is defined.
2986 CONFIG_SYS_SPL_MALLOC_SIZE
2987 The size of the malloc pool used in SPL.
2989 CONFIG_SPL_FRAMEWORK
2990 Enable the SPL framework under common/. This framework
2991 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2992 NAND loading of the Linux Kernel.
2995 Enable booting directly to an OS from SPL.
2996 See also: doc/README.falcon
2998 CONFIG_SPL_DISPLAY_PRINT
2999 For ARM, enable an optional function to print more information
3000 about the running system.
3002 CONFIG_SPL_INIT_MINIMAL
3003 Arch init code should be built for a very small image
3005 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3006 Partition on the MMC to load U-Boot from when the MMC is being
3009 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3010 Sector to load kernel uImage from when MMC is being
3011 used in raw mode (for Falcon mode)
3013 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3014 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3015 Sector and number of sectors to load kernel argument
3016 parameters from when MMC is being used in raw mode
3019 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3020 Partition on the MMC to load U-Boot from when the MMC is being
3023 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3024 Filename to read to load U-Boot when reading from filesystem
3026 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3027 Filename to read to load kernel uImage when reading
3028 from filesystem (for Falcon mode)
3030 CONFIG_SPL_FS_LOAD_ARGS_NAME
3031 Filename to read to load kernel argument parameters
3032 when reading from filesystem (for Falcon mode)
3034 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3035 Set this for NAND SPL on PPC mpc83xx targets, so that
3036 start.S waits for the rest of the SPL to load before
3037 continuing (the hardware starts execution after just
3038 loading the first page rather than the full 4K).
3040 CONFIG_SPL_SKIP_RELOCATE
3041 Avoid SPL relocation
3043 CONFIG_SPL_NAND_BASE
3044 Include nand_base.c in the SPL. Requires
3045 CONFIG_SPL_NAND_DRIVERS.
3047 CONFIG_SPL_NAND_DRIVERS
3048 SPL uses normal NAND drivers, not minimal drivers.
3051 Include standard software ECC in the SPL
3053 CONFIG_SPL_NAND_SIMPLE
3054 Support for NAND boot using simple NAND drivers that
3055 expose the cmd_ctrl() interface.
3058 Support for a lightweight UBI (fastmap) scanner and
3061 CONFIG_SPL_NAND_RAW_ONLY
3062 Support to boot only raw u-boot.bin images. Use this only
3063 if you need to save space.
3065 CONFIG_SPL_COMMON_INIT_DDR
3066 Set for common ddr init with serial presence detect in
3069 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3070 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3071 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3072 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3073 CONFIG_SYS_NAND_ECCBYTES
3074 Defines the size and behavior of the NAND that SPL uses
3077 CONFIG_SPL_NAND_BOOT
3078 Add support NAND boot
3080 CONFIG_SYS_NAND_U_BOOT_OFFS
3081 Location in NAND to read U-Boot from
3083 CONFIG_SYS_NAND_U_BOOT_DST
3084 Location in memory to load U-Boot to
3086 CONFIG_SYS_NAND_U_BOOT_SIZE
3087 Size of image to load
3089 CONFIG_SYS_NAND_U_BOOT_START
3090 Entry point in loaded image to jump to
3092 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3093 Define this if you need to first read the OOB and then the
3094 data. This is used, for example, on davinci platforms.
3096 CONFIG_SPL_OMAP3_ID_NAND
3097 Support for an OMAP3-specific set of functions to return the
3098 ID and MFR of the first attached NAND chip, if present.
3100 CONFIG_SPL_RAM_DEVICE
3101 Support for running image already present in ram, in SPL binary
3104 Image offset to which the SPL should be padded before appending
3105 the SPL payload. By default, this is defined as
3106 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3107 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3108 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3111 Final target image containing SPL and payload. Some SPLs
3112 use an arch-specific makefile fragment instead, for
3113 example if more than one image needs to be produced.
3115 CONFIG_FIT_SPL_PRINT
3116 Printing information about a FIT image adds quite a bit of
3117 code to SPL. So this is normally disabled in SPL. Use this
3118 option to re-enable it. This will affect the output of the
3119 bootm command when booting a FIT image.
3123 Enable building of TPL globally.
3126 Image offset to which the TPL should be padded before appending
3127 the TPL payload. By default, this is defined as
3128 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3129 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3130 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3132 - Interrupt support (PPC):
3134 There are common interrupt_init() and timer_interrupt()
3135 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3136 for CPU specific initialization. interrupt_init_cpu()
3137 should set decrementer_count to appropriate value. If
3138 CPU resets decrementer automatically after interrupt
3139 (ppc4xx) it should set decrementer_count to zero.
3140 timer_interrupt() calls timer_interrupt_cpu() for CPU
3141 specific handling. If board has watchdog / status_led
3142 / other_activity_monitor it works automatically from
3143 general timer_interrupt().
3146 Board initialization settings:
3147 ------------------------------
3149 During Initialization u-boot calls a number of board specific functions
3150 to allow the preparation of board specific prerequisites, e.g. pin setup
3151 before drivers are initialized. To enable these callbacks the
3152 following configuration macros have to be defined. Currently this is
3153 architecture specific, so please check arch/your_architecture/lib/board.c
3154 typically in board_init_f() and board_init_r().
3156 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3157 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3158 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3159 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3161 Configuration Settings:
3162 -----------------------
3164 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3165 Optionally it can be defined to support 64-bit memory commands.
3167 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3168 undefine this when you're short of memory.
3170 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3171 width of the commands listed in the 'help' command output.
3173 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3174 prompt for user input.
3176 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3178 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3180 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3182 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3183 the application (usually a Linux kernel) when it is
3186 - CONFIG_SYS_BAUDRATE_TABLE:
3187 List of legal baudrate settings for this board.
3189 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3190 Begin and End addresses of the area used by the
3193 - CONFIG_SYS_ALT_MEMTEST:
3194 Enable an alternate, more extensive memory test.
3196 - CONFIG_SYS_MEMTEST_SCRATCH:
3197 Scratch address used by the alternate memory test
3198 You only need to set this if address zero isn't writeable
3200 - CONFIG_SYS_MEM_RESERVE_SECURE
3201 Only implemented for ARMv8 for now.
3202 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3203 is substracted from total RAM and won't be reported to OS.
3204 This memory can be used as secure memory. A variable
3205 gd->arch.secure_ram is used to track the location. In systems
3206 the RAM base is not zero, or RAM is divided into banks,
3207 this variable needs to be recalcuated to get the address.
3209 - CONFIG_SYS_MEM_TOP_HIDE:
3210 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3211 this specified memory area will get subtracted from the top
3212 (end) of RAM and won't get "touched" at all by U-Boot. By
3213 fixing up gd->ram_size the Linux kernel should gets passed
3214 the now "corrected" memory size and won't touch it either.
3215 This should work for arch/ppc and arch/powerpc. Only Linux
3216 board ports in arch/powerpc with bootwrapper support that
3217 recalculate the memory size from the SDRAM controller setup
3218 will have to get fixed in Linux additionally.
3220 This option can be used as a workaround for the 440EPx/GRx
3221 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3224 WARNING: Please make sure that this value is a multiple of
3225 the Linux page size (normally 4k). If this is not the case,
3226 then the end address of the Linux memory will be located at a
3227 non page size aligned address and this could cause major
3230 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3231 Enable temporary baudrate change while serial download
3233 - CONFIG_SYS_SDRAM_BASE:
3234 Physical start address of SDRAM. _Must_ be 0 here.
3236 - CONFIG_SYS_FLASH_BASE:
3237 Physical start address of Flash memory.
3239 - CONFIG_SYS_MONITOR_BASE:
3240 Physical start address of boot monitor code (set by
3241 make config files to be same as the text base address
3242 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3243 CONFIG_SYS_FLASH_BASE when booting from flash.
3245 - CONFIG_SYS_MONITOR_LEN:
3246 Size of memory reserved for monitor code, used to
3247 determine _at_compile_time_ (!) if the environment is
3248 embedded within the U-Boot image, or in a separate
3251 - CONFIG_SYS_MALLOC_LEN:
3252 Size of DRAM reserved for malloc() use.
3254 - CONFIG_SYS_MALLOC_F_LEN
3255 Size of the malloc() pool for use before relocation. If
3256 this is defined, then a very simple malloc() implementation
3257 will become available before relocation. The address is just
3258 below the global data, and the stack is moved down to make
3261 This feature allocates regions with increasing addresses
3262 within the region. calloc() is supported, but realloc()
3263 is not available. free() is supported but does nothing.
3264 The memory will be freed (or in fact just forgotten) when
3265 U-Boot relocates itself.
3267 - CONFIG_SYS_MALLOC_SIMPLE
3268 Provides a simple and small malloc() and calloc() for those
3269 boards which do not use the full malloc in SPL (which is
3270 enabled with CONFIG_SYS_SPL_MALLOC_START).
3272 - CONFIG_SYS_NONCACHED_MEMORY:
3273 Size of non-cached memory area. This area of memory will be
3274 typically located right below the malloc() area and mapped
3275 uncached in the MMU. This is useful for drivers that would
3276 otherwise require a lot of explicit cache maintenance. For
3277 some drivers it's also impossible to properly maintain the
3278 cache. For example if the regions that need to be flushed
3279 are not a multiple of the cache-line size, *and* padding
3280 cannot be allocated between the regions to align them (i.e.
3281 if the HW requires a contiguous array of regions, and the
3282 size of each region is not cache-aligned), then a flush of
3283 one region may result in overwriting data that hardware has
3284 written to another region in the same cache-line. This can
3285 happen for example in network drivers where descriptors for
3286 buffers are typically smaller than the CPU cache-line (e.g.
3287 16 bytes vs. 32 or 64 bytes).
3289 Non-cached memory is only supported on 32-bit ARM at present.
3291 - CONFIG_SYS_BOOTM_LEN:
3292 Normally compressed uImages are limited to an
3293 uncompressed size of 8 MBytes. If this is not enough,
3294 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3295 to adjust this setting to your needs.
3297 - CONFIG_SYS_BOOTMAPSZ:
3298 Maximum size of memory mapped by the startup code of
3299 the Linux kernel; all data that must be processed by
3300 the Linux kernel (bd_info, boot arguments, FDT blob if
3301 used) must be put below this limit, unless "bootm_low"
3302 environment variable is defined and non-zero. In such case
3303 all data for the Linux kernel must be between "bootm_low"
3304 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3305 variable "bootm_mapsize" will override the value of
3306 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3307 then the value in "bootm_size" will be used instead.
3309 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3310 Enable initrd_high functionality. If defined then the
3311 initrd_high feature is enabled and the bootm ramdisk subcommand
3314 - CONFIG_SYS_BOOT_GET_CMDLINE:
3315 Enables allocating and saving kernel cmdline in space between
3316 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3318 - CONFIG_SYS_BOOT_GET_KBD:
3319 Enables allocating and saving a kernel copy of the bd_info in
3320 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3322 - CONFIG_SYS_MAX_FLASH_BANKS:
3323 Max number of Flash memory banks
3325 - CONFIG_SYS_MAX_FLASH_SECT:
3326 Max number of sectors on a Flash chip
3328 - CONFIG_SYS_FLASH_ERASE_TOUT:
3329 Timeout for Flash erase operations (in ms)
3331 - CONFIG_SYS_FLASH_WRITE_TOUT:
3332 Timeout for Flash write operations (in ms)
3334 - CONFIG_SYS_FLASH_LOCK_TOUT
3335 Timeout for Flash set sector lock bit operation (in ms)
3337 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3338 Timeout for Flash clear lock bits operation (in ms)
3340 - CONFIG_SYS_FLASH_PROTECTION
3341 If defined, hardware flash sectors protection is used
3342 instead of U-Boot software protection.
3344 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3346 Enable TFTP transfers directly to flash memory;
3347 without this option such a download has to be
3348 performed in two steps: (1) download to RAM, and (2)
3349 copy from RAM to flash.
3351 The two-step approach is usually more reliable, since
3352 you can check if the download worked before you erase
3353 the flash, but in some situations (when system RAM is
3354 too limited to allow for a temporary copy of the
3355 downloaded image) this option may be very useful.
3357 - CONFIG_SYS_FLASH_CFI:
3358 Define if the flash driver uses extra elements in the
3359 common flash structure for storing flash geometry.
3361 - CONFIG_FLASH_CFI_DRIVER
3362 This option also enables the building of the cfi_flash driver
3363 in the drivers directory
3365 - CONFIG_FLASH_CFI_MTD
3366 This option enables the building of the cfi_mtd driver
3367 in the drivers directory. The driver exports CFI flash
3370 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3371 Use buffered writes to flash.
3373 - CONFIG_FLASH_SPANSION_S29WS_N
3374 s29ws-n MirrorBit flash has non-standard addresses for buffered
3377 - CONFIG_SYS_FLASH_QUIET_TEST
3378 If this option is defined, the common CFI flash doesn't
3379 print it's warning upon not recognized FLASH banks. This
3380 is useful, if some of the configured banks are only
3381 optionally available.
3383 - CONFIG_FLASH_SHOW_PROGRESS
3384 If defined (must be an integer), print out countdown
3385 digits and dots. Recommended value: 45 (9..1) for 80
3386 column displays, 15 (3..1) for 40 column displays.
3388 - CONFIG_FLASH_VERIFY
3389 If defined, the content of the flash (destination) is compared
3390 against the source after the write operation. An error message
3391 will be printed when the contents are not identical.
3392 Please note that this option is useless in nearly all cases,
3393 since such flash programming errors usually are detected earlier
3394 while unprotecting/erasing/programming. Please only enable
3395 this option if you really know what you are doing.
3397 - CONFIG_SYS_RX_ETH_BUFFER:
3398 Defines the number of Ethernet receive buffers. On some
3399 Ethernet controllers it is recommended to set this value
3400 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3401 buffers can be full shortly after enabling the interface
3402 on high Ethernet traffic.
3403 Defaults to 4 if not defined.
3405 - CONFIG_ENV_MAX_ENTRIES
3407 Maximum number of entries in the hash table that is used
3408 internally to store the environment settings. The default
3409 setting is supposed to be generous and should work in most
3410 cases. This setting can be used to tune behaviour; see
3411 lib/hashtable.c for details.
3413 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3414 - CONFIG_ENV_FLAGS_LIST_STATIC
3415 Enable validation of the values given to environment variables when
3416 calling env set. Variables can be restricted to only decimal,
3417 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3418 the variables can also be restricted to IP address or MAC address.
3420 The format of the list is:
3421 type_attribute = [s|d|x|b|i|m]
3422 access_attribute = [a|r|o|c]
3423 attributes = type_attribute[access_attribute]
3424 entry = variable_name[:attributes]
3427 The type attributes are:
3428 s - String (default)
3431 b - Boolean ([1yYtT|0nNfF])
3435 The access attributes are:
3441 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3442 Define this to a list (string) to define the ".flags"
3443 environment variable in the default or embedded environment.
3445 - CONFIG_ENV_FLAGS_LIST_STATIC
3446 Define this to a list (string) to define validation that
3447 should be done if an entry is not found in the ".flags"
3448 environment variable. To override a setting in the static
3449 list, simply add an entry for the same variable name to the
3452 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3453 regular expression. This allows multiple variables to define the same
3454 flags without explicitly listing them for each variable.
3456 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3457 If defined, don't allow the -f switch to env set override variable
3461 If stdint.h is available with your toolchain you can define this
3462 option to enable it. You can provide option 'USE_STDINT=1' when
3463 building U-Boot to enable this.
3465 The following definitions that deal with the placement and management
3466 of environment data (variable area); in general, we support the
3467 following configurations:
3469 - CONFIG_BUILD_ENVCRC:
3471 Builds up envcrc with the target environment so that external utils
3472 may easily extract it and embed it in final U-Boot images.
3474 - CONFIG_ENV_IS_IN_FLASH:
3476 Define this if the environment is in flash memory.
3478 a) The environment occupies one whole flash sector, which is
3479 "embedded" in the text segment with the U-Boot code. This
3480 happens usually with "bottom boot sector" or "top boot
3481 sector" type flash chips, which have several smaller
3482 sectors at the start or the end. For instance, such a
3483 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3484 such a case you would place the environment in one of the
3485 4 kB sectors - with U-Boot code before and after it. With
3486 "top boot sector" type flash chips, you would put the
3487 environment in one of the last sectors, leaving a gap
3488 between U-Boot and the environment.
3490 - CONFIG_ENV_OFFSET:
3492 Offset of environment data (variable area) to the
3493 beginning of flash memory; for instance, with bottom boot
3494 type flash chips the second sector can be used: the offset
3495 for this sector is given here.
3497 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3501 This is just another way to specify the start address of
3502 the flash sector containing the environment (instead of
3505 - CONFIG_ENV_SECT_SIZE:
3507 Size of the sector containing the environment.
3510 b) Sometimes flash chips have few, equal sized, BIG sectors.
3511 In such a case you don't want to spend a whole sector for
3516 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3517 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3518 of this flash sector for the environment. This saves
3519 memory for the RAM copy of the environment.
3521 It may also save flash memory if you decide to use this
3522 when your environment is "embedded" within U-Boot code,
3523 since then the remainder of the flash sector could be used
3524 for U-Boot code. It should be pointed out that this is
3525 STRONGLY DISCOURAGED from a robustness point of view:
3526 updating the environment in flash makes it always
3527 necessary to erase the WHOLE sector. If something goes
3528 wrong before the contents has been restored from a copy in
3529 RAM, your target system will be dead.
3531 - CONFIG_ENV_ADDR_REDUND
3532 CONFIG_ENV_SIZE_REDUND
3534 These settings describe a second storage area used to hold
3535 a redundant copy of the environment data, so that there is
3536 a valid backup copy in case there is a power failure during
3537 a "saveenv" operation.
3539 BE CAREFUL! Any changes to the flash layout, and some changes to the
3540 source code will make it necessary to adapt <board>/u-boot.lds*
3544 - CONFIG_ENV_IS_IN_NVRAM:
3546 Define this if you have some non-volatile memory device
3547 (NVRAM, battery buffered SRAM) which you want to use for the
3553 These two #defines are used to determine the memory area you
3554 want to use for environment. It is assumed that this memory
3555 can just be read and written to, without any special
3558 BE CAREFUL! The first access to the environment happens quite early
3559 in U-Boot initialization (when we try to get the setting of for the
3560 console baudrate). You *MUST* have mapped your NVRAM area then, or
3563 Please note that even with NVRAM we still use a copy of the
3564 environment in RAM: we could work on NVRAM directly, but we want to
3565 keep settings there always unmodified except somebody uses "saveenv"
3566 to save the current settings.
3569 - CONFIG_ENV_IS_IN_EEPROM:
3571 Use this if you have an EEPROM or similar serial access
3572 device and a driver for it.
3574 - CONFIG_ENV_OFFSET:
3577 These two #defines specify the offset and size of the
3578 environment area within the total memory of your EEPROM.
3580 - CONFIG_SYS_I2C_EEPROM_ADDR:
3581 If defined, specified the chip address of the EEPROM device.
3582 The default address is zero.
3584 - CONFIG_SYS_I2C_EEPROM_BUS:
3585 If defined, specified the i2c bus of the EEPROM device.
3587 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3588 If defined, the number of bits used to address bytes in a
3589 single page in the EEPROM device. A 64 byte page, for example
3590 would require six bits.
3592 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3593 If defined, the number of milliseconds to delay between
3594 page writes. The default is zero milliseconds.
3596 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3597 The length in bytes of the EEPROM memory array address. Note
3598 that this is NOT the chip address length!
3600 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3601 EEPROM chips that implement "address overflow" are ones
3602 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3603 address and the extra bits end up in the "chip address" bit
3604 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3607 Note that we consider the length of the address field to
3608 still be one byte because the extra address bits are hidden
3609 in the chip address.
3611 - CONFIG_SYS_EEPROM_SIZE:
3612 The size in bytes of the EEPROM device.
3614 - CONFIG_ENV_EEPROM_IS_ON_I2C
3615 define this, if you have I2C and SPI activated, and your
3616 EEPROM, which holds the environment, is on the I2C bus.
3618 - CONFIG_I2C_ENV_EEPROM_BUS
3619 if you have an Environment on an EEPROM reached over
3620 I2C muxes, you can define here, how to reach this
3621 EEPROM. For example:
3623 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3625 EEPROM which holds the environment, is reached over
3626 a pca9547 i2c mux with address 0x70, channel 3.
3628 - CONFIG_ENV_IS_IN_DATAFLASH:
3630 Define this if you have a DataFlash memory device which you
3631 want to use for the environment.
3633 - CONFIG_ENV_OFFSET:
3637 These three #defines specify the offset and size of the
3638 environment area within the total memory of your DataFlash placed
3639 at the specified address.
3641 - CONFIG_ENV_IS_IN_SPI_FLASH:
3643 Define this if you have a SPI Flash memory device which you
3644 want to use for the environment.
3646 - CONFIG_ENV_OFFSET:
3649 These two #defines specify the offset and size of the
3650 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
3651 aligned to an erase sector boundary.
3653 - CONFIG_ENV_SECT_SIZE:
3655 Define the SPI flash's sector size.
3657 - CONFIG_ENV_OFFSET_REDUND (optional):
3659 This setting describes a second storage area of CONFIG_ENV_SIZE
3660 size used to hold a redundant copy of the environment data, so
3661 that there is a valid backup copy in case there is a power failure
3662 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3663 aligned to an erase sector boundary.
3665 - CONFIG_ENV_SPI_BUS (optional):
3666 - CONFIG_ENV_SPI_CS (optional):
3668 Define the SPI bus and chip select. If not defined they will be 0.
3670 - CONFIG_ENV_SPI_MAX_HZ (optional):
3672 Define the SPI max work clock. If not defined then use 1MHz.
3674 - CONFIG_ENV_SPI_MODE (optional):
3676 Define the SPI work mode. If not defined then use SPI_MODE_3.
3678 - CONFIG_ENV_IS_IN_REMOTE:
3680 Define this if you have a remote memory space which you
3681 want to use for the local device's environment.
3686 These two #defines specify the address and size of the
3687 environment area within the remote memory space. The
3688 local device can get the environment from remote memory
3689 space by SRIO or PCIE links.
3691 BE CAREFUL! For some special cases, the local device can not use
3692 "saveenv" command. For example, the local device will get the
3693 environment stored in a remote NOR flash by SRIO or PCIE link,
3694 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3696 - CONFIG_ENV_IS_IN_NAND:
3698 Define this if you have a NAND device which you want to use
3699 for the environment.
3701 - CONFIG_ENV_OFFSET:
3704 These two #defines specify the offset and size of the environment
3705 area within the first NAND device. CONFIG_ENV_OFFSET must be
3706 aligned to an erase block boundary.
3708 - CONFIG_ENV_OFFSET_REDUND (optional):
3710 This setting describes a second storage area of CONFIG_ENV_SIZE
3711 size used to hold a redundant copy of the environment data, so
3712 that there is a valid backup copy in case there is a power failure
3713 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3714 aligned to an erase block boundary.
3716 - CONFIG_ENV_RANGE (optional):
3718 Specifies the length of the region in which the environment
3719 can be written. This should be a multiple of the NAND device's
3720 block size. Specifying a range with more erase blocks than
3721 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3722 the range to be avoided.
3724 - CONFIG_ENV_OFFSET_OOB (optional):
3726 Enables support for dynamically retrieving the offset of the
3727 environment from block zero's out-of-band data. The
3728 "nand env.oob" command can be used to record this offset.
3729 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3730 using CONFIG_ENV_OFFSET_OOB.
3732 - CONFIG_NAND_ENV_DST
3734 Defines address in RAM to which the nand_spl code should copy the
3735 environment. If redundant environment is used, it will be copied to
3736 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3738 - CONFIG_ENV_IS_IN_UBI:
3740 Define this if you have an UBI volume that you want to use for the
3741 environment. This has the benefit of wear-leveling the environment
3742 accesses, which is important on NAND.
3744 - CONFIG_ENV_UBI_PART:
3746 Define this to a string that is the mtd partition containing the UBI.
3748 - CONFIG_ENV_UBI_VOLUME:
3750 Define this to the name of the volume that you want to store the
3753 - CONFIG_ENV_UBI_VOLUME_REDUND:
3755 Define this to the name of another volume to store a second copy of
3756 the environment in. This will enable redundant environments in UBI.
3757 It is assumed that both volumes are in the same MTD partition.
3759 - CONFIG_UBI_SILENCE_MSG
3760 - CONFIG_UBIFS_SILENCE_MSG
3762 You will probably want to define these to avoid a really noisy system
3763 when storing the env in UBI.
3765 - CONFIG_ENV_IS_IN_FAT:
3766 Define this if you want to use the FAT file system for the environment.
3768 - FAT_ENV_INTERFACE:
3770 Define this to a string that is the name of the block device.
3772 - FAT_ENV_DEVICE_AND_PART:
3774 Define this to a string to specify the partition of the device. It can
3777 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
3778 - "D:P": device D partition P. Error occurs if device D has no
3781 - "D" or "D:": device D partition 1 if device D has partition
3782 table, or the whole device D if has no partition
3784 - "D:auto": first partition in device D with bootable flag set.
3785 If none, first valid partition in device D. If no
3786 partition table then means device D.
3790 It's a string of the FAT file name. This file use to store the
3794 This must be enabled. Otherwise it cannot save the environment file.
3796 - CONFIG_ENV_IS_IN_MMC:
3798 Define this if you have an MMC device which you want to use for the
3801 - CONFIG_SYS_MMC_ENV_DEV:
3803 Specifies which MMC device the environment is stored in.
3805 - CONFIG_SYS_MMC_ENV_PART (optional):
3807 Specifies which MMC partition the environment is stored in. If not
3808 set, defaults to partition 0, the user area. Common values might be
3809 1 (first MMC boot partition), 2 (second MMC boot partition).
3811 - CONFIG_ENV_OFFSET:
3814 These two #defines specify the offset and size of the environment
3815 area within the specified MMC device.
3817 If offset is positive (the usual case), it is treated as relative to
3818 the start of the MMC partition. If offset is negative, it is treated
3819 as relative to the end of the MMC partition. This can be useful if
3820 your board may be fitted with different MMC devices, which have
3821 different sizes for the MMC partitions, and you always want the
3822 environment placed at the very end of the partition, to leave the
3823 maximum possible space before it, to store other data.
3825 These two values are in units of bytes, but must be aligned to an
3826 MMC sector boundary.
3828 - CONFIG_ENV_OFFSET_REDUND (optional):
3830 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3831 hold a redundant copy of the environment data. This provides a
3832 valid backup copy in case the other copy is corrupted, e.g. due
3833 to a power failure during a "saveenv" operation.
3835 This value may also be positive or negative; this is handled in the
3836 same way as CONFIG_ENV_OFFSET.
3838 This value is also in units of bytes, but must also be aligned to
3839 an MMC sector boundary.
3841 - CONFIG_ENV_SIZE_REDUND (optional):
3843 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3844 set. If this value is set, it must be set to the same value as
3847 Please note that the environment is read-only until the monitor
3848 has been relocated to RAM and a RAM copy of the environment has been
3849 created; also, when using EEPROM you will have to use getenv_f()
3850 until then to read environment variables.
3852 The environment is protected by a CRC32 checksum. Before the monitor
3853 is relocated into RAM, as a result of a bad CRC you will be working
3854 with the compiled-in default environment - *silently*!!! [This is
3855 necessary, because the first environment variable we need is the
3856 "baudrate" setting for the console - if we have a bad CRC, we don't
3857 have any device yet where we could complain.]
3859 Note: once the monitor has been relocated, then it will complain if
3860 the default environment is used; a new CRC is computed as soon as you
3861 use the "saveenv" command to store a valid environment.
3863 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3864 Echo the inverted Ethernet link state to the fault LED.
3866 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3867 also needs to be defined.
3869 - CONFIG_SYS_FAULT_MII_ADDR:
3870 MII address of the PHY to check for the Ethernet link state.
3872 - CONFIG_NS16550_MIN_FUNCTIONS:
3873 Define this if you desire to only have use of the NS16550_init
3874 and NS16550_putc functions for the serial driver located at
3875 drivers/serial/ns16550.c. This option is useful for saving
3876 space for already greatly restricted images, including but not
3877 limited to NAND_SPL configurations.
3879 - CONFIG_DISPLAY_BOARDINFO
3880 Display information about the board that U-Boot is running on
3881 when U-Boot starts up. The board function checkboard() is called
3884 - CONFIG_DISPLAY_BOARDINFO_LATE
3885 Similar to the previous option, but display this information
3886 later, once stdio is running and output goes to the LCD, if
3889 - CONFIG_BOARD_SIZE_LIMIT:
3890 Maximum size of the U-Boot image. When defined, the
3891 build system checks that the actual size does not
3894 Low Level (hardware related) configuration options:
3895 ---------------------------------------------------
3897 - CONFIG_SYS_CACHELINE_SIZE:
3898 Cache Line Size of the CPU.
3900 - CONFIG_SYS_CCSRBAR_DEFAULT:
3901 Default (power-on reset) physical address of CCSR on Freescale
3904 - CONFIG_SYS_CCSRBAR:
3905 Virtual address of CCSR. On a 32-bit build, this is typically
3906 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3908 - CONFIG_SYS_CCSRBAR_PHYS:
3909 Physical address of CCSR. CCSR can be relocated to a new
3910 physical address, if desired. In this case, this macro should
3911 be set to that address. Otherwise, it should be set to the
3912 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3913 is typically relocated on 36-bit builds. It is recommended
3914 that this macro be defined via the _HIGH and _LOW macros:
3916 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3917 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3919 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3920 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3921 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3922 used in assembly code, so it must not contain typecasts or
3923 integer size suffixes (e.g. "ULL").
3925 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3926 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3927 used in assembly code, so it must not contain typecasts or
3928 integer size suffixes (e.g. "ULL").
3930 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3931 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3932 forced to a value that ensures that CCSR is not relocated.
3934 - Floppy Disk Support:
3935 CONFIG_SYS_FDC_DRIVE_NUMBER
3937 the default drive number (default value 0)
3939 CONFIG_SYS_ISA_IO_STRIDE
3941 defines the spacing between FDC chipset registers
3944 CONFIG_SYS_ISA_IO_OFFSET
3946 defines the offset of register from address. It
3947 depends on which part of the data bus is connected to
3948 the FDC chipset. (default value 0)
3950 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3951 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3954 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3955 fdc_hw_init() is called at the beginning of the FDC
3956 setup. fdc_hw_init() must be provided by the board
3957 source code. It is used to make hardware-dependent
3961 Most IDE controllers were designed to be connected with PCI
3962 interface. Only few of them were designed for AHB interface.
3963 When software is doing ATA command and data transfer to
3964 IDE devices through IDE-AHB controller, some additional
3965 registers accessing to these kind of IDE-AHB controller
3968 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3969 DO NOT CHANGE unless you know exactly what you're
3970 doing! (11-4) [82xx systems only]
3972 - CONFIG_SYS_INIT_RAM_ADDR:
3974 Start address of memory area that can be used for
3975 initial data and stack; please note that this must be
3976 writable memory that is working WITHOUT special
3977 initialization, i. e. you CANNOT use normal RAM which
3978 will become available only after programming the
3979 memory controller and running certain initialization
3982 U-Boot uses the following memory types:
3983 - PPC4xx: data cache
3985 - CONFIG_SYS_GBL_DATA_OFFSET:
3987 Offset of the initial data structure in the memory
3988 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3989 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3990 data is located at the end of the available space
3991 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3992 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3993 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3994 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3997 On the MPC824X (or other systems that use the data
3998 cache for initial memory) the address chosen for
3999 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4000 point to an otherwise UNUSED address space between
4001 the top of RAM and the start of the PCI space.
4003 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4005 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4007 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4009 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4011 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4013 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4015 - CONFIG_SYS_OR_TIMING_SDRAM:
4018 - CONFIG_SYS_MAMR_PTA:
4019 periodic timer for refresh
4021 - CONFIG_SYS_DER: Debug Event Register (37-47)
4023 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4024 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4025 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4026 CONFIG_SYS_BR1_PRELIM:
4027 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4029 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4030 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4031 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4032 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4034 - CONFIG_PCI_DISABLE_PCIE:
4035 Disable PCI-Express on systems where it is supported but not
4038 - CONFIG_PCI_ENUM_ONLY
4039 Only scan through and get the devices on the buses.
4040 Don't do any setup work, presumably because someone or
4041 something has already done it, and we don't need to do it
4042 a second time. Useful for platforms that are pre-booted
4043 by coreboot or similar.
4045 - CONFIG_PCI_INDIRECT_BRIDGE:
4046 Enable support for indirect PCI bridges.
4049 Chip has SRIO or not
4052 Board has SRIO 1 port available
4055 Board has SRIO 2 port available
4057 - CONFIG_SRIO_PCIE_BOOT_MASTER
4058 Board can support master function for Boot from SRIO and PCIE
4060 - CONFIG_SYS_SRIOn_MEM_VIRT:
4061 Virtual Address of SRIO port 'n' memory region
4063 - CONFIG_SYS_SRIOn_MEM_PHYS:
4064 Physical Address of SRIO port 'n' memory region
4066 - CONFIG_SYS_SRIOn_MEM_SIZE:
4067 Size of SRIO port 'n' memory region
4069 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4070 Defined to tell the NAND controller that the NAND chip is using
4072 Not all NAND drivers use this symbol.
4073 Example of drivers that use it:
4074 - drivers/mtd/nand/ndfc.c
4075 - drivers/mtd/nand/mxc_nand.c
4077 - CONFIG_SYS_NDFC_EBC0_CFG
4078 Sets the EBC0_CFG register for the NDFC. If not defined
4079 a default value will be used.
4082 Get DDR timing information from an I2C EEPROM. Common
4083 with pluggable memory modules such as SODIMMs
4086 I2C address of the SPD EEPROM
4088 - CONFIG_SYS_SPD_BUS_NUM
4089 If SPD EEPROM is on an I2C bus other than the first
4090 one, specify here. Note that the value must resolve
4091 to something your driver can deal with.
4093 - CONFIG_SYS_DDR_RAW_TIMING
4094 Get DDR timing information from other than SPD. Common with
4095 soldered DDR chips onboard without SPD. DDR raw timing
4096 parameters are extracted from datasheet and hard-coded into
4097 header files or board specific files.
4099 - CONFIG_FSL_DDR_INTERACTIVE
4100 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4102 - CONFIG_FSL_DDR_SYNC_REFRESH
4103 Enable sync of refresh for multiple controllers.
4105 - CONFIG_FSL_DDR_BIST
4106 Enable built-in memory test for Freescale DDR controllers.
4108 - CONFIG_SYS_83XX_DDR_USES_CS0
4109 Only for 83xx systems. If specified, then DDR should
4110 be configured using CS0 and CS1 instead of CS2 and CS3.
4113 Enable RMII mode for all FECs.
4114 Note that this is a global option, we can't
4115 have one FEC in standard MII mode and another in RMII mode.
4117 - CONFIG_CRC32_VERIFY
4118 Add a verify option to the crc32 command.
4121 => crc32 -v <address> <count> <crc32>
4123 Where address/count indicate a memory area
4124 and crc32 is the correct crc32 which the
4128 Add the "loopw" memory command. This only takes effect if
4129 the memory commands are activated globally (CONFIG_CMD_MEM).
4132 Add the "mdc" and "mwc" memory commands. These are cyclic
4137 This command will print 4 bytes (10,11,12,13) each 500 ms.
4139 => mwc.l 100 12345678 10
4140 This command will write 12345678 to address 100 all 10 ms.
4142 This only takes effect if the memory commands are activated
4143 globally (CONFIG_CMD_MEM).
4145 - CONFIG_SKIP_LOWLEVEL_INIT
4146 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4147 low level initializations (like setting up the memory
4148 controller) are omitted and/or U-Boot does not
4149 relocate itself into RAM.
4151 Normally this variable MUST NOT be defined. The only
4152 exception is when U-Boot is loaded (to RAM) by some
4153 other boot loader or by a debugger which performs
4154 these initializations itself.
4156 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4157 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4158 to be skipped. The normal CP15 init (such as enabling the
4159 instruction cache) is still performed.
4162 Modifies the behaviour of start.S when compiling a loader
4163 that is executed before the actual U-Boot. E.g. when
4164 compiling a NAND SPL.
4167 Modifies the behaviour of start.S when compiling a loader
4168 that is executed after the SPL and before the actual U-Boot.
4169 It is loaded by the SPL.
4171 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4172 Only for 85xx systems. If this variable is specified, the section
4173 .resetvec is not kept and the section .bootpg is placed in the
4174 previous 4k of the .text section.
4176 - CONFIG_ARCH_MAP_SYSMEM
4177 Generally U-Boot (and in particular the md command) uses
4178 effective address. It is therefore not necessary to regard
4179 U-Boot address as virtual addresses that need to be translated
4180 to physical addresses. However, sandbox requires this, since
4181 it maintains its own little RAM buffer which contains all
4182 addressable memory. This option causes some memory accesses
4183 to be mapped through map_sysmem() / unmap_sysmem().
4185 - CONFIG_X86_RESET_VECTOR
4186 If defined, the x86 reset vector code is included. This is not
4187 needed when U-Boot is running from Coreboot.
4189 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4190 Enables the RTC32K OSC on AM33xx based plattforms
4192 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4193 Option to disable subpage write in NAND driver
4194 driver that uses this:
4195 drivers/mtd/nand/davinci_nand.c
4197 Freescale QE/FMAN Firmware Support:
4198 -----------------------------------
4200 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4201 loading of "firmware", which is encoded in the QE firmware binary format.
4202 This firmware often needs to be loaded during U-Boot booting, so macros
4203 are used to identify the storage device (NOR flash, SPI, etc) and the address
4206 - CONFIG_SYS_FMAN_FW_ADDR
4207 The address in the storage device where the FMAN microcode is located. The
4208 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4211 - CONFIG_SYS_QE_FW_ADDR
4212 The address in the storage device where the QE microcode is located. The
4213 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4216 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4217 The maximum possible size of the firmware. The firmware binary format
4218 has a field that specifies the actual size of the firmware, but it
4219 might not be possible to read any part of the firmware unless some
4220 local storage is allocated to hold the entire firmware first.
4222 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4223 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4224 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4225 virtual address in NOR flash.
4227 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4228 Specifies that QE/FMAN firmware is located in NAND flash.
4229 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4231 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4232 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4233 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4235 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4236 Specifies that QE/FMAN firmware is located in the remote (master)
4237 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4238 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4239 window->master inbound window->master LAW->the ucode address in
4240 master's memory space.
4242 Freescale Layerscape Management Complex Firmware Support:
4243 ---------------------------------------------------------
4244 The Freescale Layerscape Management Complex (MC) supports the loading of
4246 This firmware often needs to be loaded during U-Boot booting, so macros
4247 are used to identify the storage device (NOR flash, SPI, etc) and the address
4250 - CONFIG_FSL_MC_ENET
4251 Enable the MC driver for Layerscape SoCs.
4253 Freescale Layerscape Debug Server Support:
4254 -------------------------------------------
4255 The Freescale Layerscape Debug Server Support supports the loading of
4256 "Debug Server firmware" and triggering SP boot-rom.
4257 This firmware often needs to be loaded during U-Boot booting.
4259 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4260 Define alignment of reserved memory MC requires
4265 In order to achieve reproducible builds, timestamps used in the U-Boot build
4266 process have to be set to a fixed value.
4268 This is done using the SOURCE_DATE_EPOCH environment variable.
4269 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4270 option for U-Boot or an environment variable in U-Boot.
4272 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4274 Building the Software:
4275 ======================
4277 Building U-Boot has been tested in several native build environments
4278 and in many different cross environments. Of course we cannot support
4279 all possibly existing versions of cross development tools in all
4280 (potentially obsolete) versions. In case of tool chain problems we
4281 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4282 which is extensively used to build and test U-Boot.
4284 If you are not using a native environment, it is assumed that you
4285 have GNU cross compiling tools available in your path. In this case,
4286 you must set the environment variable CROSS_COMPILE in your shell.
4287 Note that no changes to the Makefile or any other source files are
4288 necessary. For example using the ELDK on a 4xx CPU, please enter:
4290 $ CROSS_COMPILE=ppc_4xx-
4291 $ export CROSS_COMPILE
4293 Note: If you wish to generate Windows versions of the utilities in
4294 the tools directory you can use the MinGW toolchain
4295 (http://www.mingw.org). Set your HOST tools to the MinGW
4296 toolchain and execute 'make tools'. For example:
4298 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4300 Binaries such as tools/mkimage.exe will be created which can
4301 be executed on computers running Windows.
4303 U-Boot is intended to be simple to build. After installing the
4304 sources you must configure U-Boot for one specific board type. This
4309 where "NAME_defconfig" is the name of one of the existing configu-
4310 rations; see boards.cfg for supported names.
4312 Note: for some board special configuration names may exist; check if
4313 additional information is available from the board vendor; for
4314 instance, the TQM823L systems are available without (standard)
4315 or with LCD support. You can select such additional "features"
4316 when choosing the configuration, i. e.
4318 make TQM823L_defconfig
4319 - will configure for a plain TQM823L, i. e. no LCD support
4321 make TQM823L_LCD_defconfig
4322 - will configure for a TQM823L with U-Boot console on LCD
4327 Finally, type "make all", and you should get some working U-Boot
4328 images ready for download to / installation on your system:
4330 - "u-boot.bin" is a raw binary image
4331 - "u-boot" is an image in ELF binary format
4332 - "u-boot.srec" is in Motorola S-Record format
4334 By default the build is performed locally and the objects are saved
4335 in the source directory. One of the two methods can be used to change
4336 this behavior and build U-Boot to some external directory:
4338 1. Add O= to the make command line invocations:
4340 make O=/tmp/build distclean
4341 make O=/tmp/build NAME_defconfig
4342 make O=/tmp/build all
4344 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4346 export KBUILD_OUTPUT=/tmp/build
4351 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4355 Please be aware that the Makefiles assume you are using GNU make, so
4356 for instance on NetBSD you might need to use "gmake" instead of
4360 If the system board that you have is not listed, then you will need
4361 to port U-Boot to your hardware platform. To do this, follow these
4364 1. Create a new directory to hold your board specific code. Add any
4365 files you need. In your board directory, you will need at least
4366 the "Makefile" and a "<board>.c".
4367 2. Create a new configuration file "include/configs/<board>.h" for
4369 3. If you're porting U-Boot to a new CPU, then also create a new
4370 directory to hold your CPU specific code. Add any files you need.
4371 4. Run "make <board>_defconfig" with your new name.
4372 5. Type "make", and you should get a working "u-boot.srec" file
4373 to be installed on your target system.
4374 6. Debug and solve any problems that might arise.
4375 [Of course, this last step is much harder than it sounds.]
4378 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4379 ==============================================================
4381 If you have modified U-Boot sources (for instance added a new board
4382 or support for new devices, a new CPU, etc.) you are expected to
4383 provide feedback to the other developers. The feedback normally takes
4384 the form of a "patch", i. e. a context diff against a certain (latest
4385 official or latest in the git repository) version of U-Boot sources.
4387 But before you submit such a patch, please verify that your modifi-
4388 cation did not break existing code. At least make sure that *ALL* of
4389 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4390 just run the buildman script (tools/buildman/buildman), which will
4391 configure and build U-Boot for ALL supported system. Be warned, this
4392 will take a while. Please see the buildman README, or run 'buildman -H'
4396 See also "U-Boot Porting Guide" below.
4399 Monitor Commands - Overview:
4400 ============================
4402 go - start application at address 'addr'
4403 run - run commands in an environment variable
4404 bootm - boot application image from memory
4405 bootp - boot image via network using BootP/TFTP protocol
4406 bootz - boot zImage from memory
4407 tftpboot- boot image via network using TFTP protocol
4408 and env variables "ipaddr" and "serverip"
4409 (and eventually "gatewayip")
4410 tftpput - upload a file via network using TFTP protocol
4411 rarpboot- boot image via network using RARP/TFTP protocol
4412 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4413 loads - load S-Record file over serial line
4414 loadb - load binary file over serial line (kermit mode)
4416 mm - memory modify (auto-incrementing)
4417 nm - memory modify (constant address)
4418 mw - memory write (fill)
4420 cmp - memory compare
4421 crc32 - checksum calculation
4422 i2c - I2C sub-system
4423 sspi - SPI utility commands
4424 base - print or set address offset
4425 printenv- print environment variables
4426 setenv - set environment variables
4427 saveenv - save environment variables to persistent storage
4428 protect - enable or disable FLASH write protection
4429 erase - erase FLASH memory
4430 flinfo - print FLASH memory information
4431 nand - NAND memory operations (see doc/README.nand)
4432 bdinfo - print Board Info structure
4433 iminfo - print header information for application image
4434 coninfo - print console devices and informations
4435 ide - IDE sub-system
4436 loop - infinite loop on address range
4437 loopw - infinite write loop on address range
4438 mtest - simple RAM test
4439 icache - enable or disable instruction cache
4440 dcache - enable or disable data cache
4441 reset - Perform RESET of the CPU
4442 echo - echo args to console
4443 version - print monitor version
4444 help - print online help
4445 ? - alias for 'help'
4448 Monitor Commands - Detailed Description:
4449 ========================================
4453 For now: just type "help <command>".
4456 Environment Variables:
4457 ======================
4459 U-Boot supports user configuration using Environment Variables which
4460 can be made persistent by saving to Flash memory.
4462 Environment Variables are set using "setenv", printed using
4463 "printenv", and saved to Flash using "saveenv". Using "setenv"
4464 without a value can be used to delete a variable from the
4465 environment. As long as you don't save the environment you are
4466 working with an in-memory copy. In case the Flash area containing the
4467 environment is erased by accident, a default environment is provided.
4469 Some configuration options can be set using Environment Variables.
4471 List of environment variables (most likely not complete):
4473 baudrate - see CONFIG_BAUDRATE
4475 bootdelay - see CONFIG_BOOTDELAY
4477 bootcmd - see CONFIG_BOOTCOMMAND
4479 bootargs - Boot arguments when booting an RTOS image
4481 bootfile - Name of the image to load with TFTP
4483 bootm_low - Memory range available for image processing in the bootm
4484 command can be restricted. This variable is given as
4485 a hexadecimal number and defines lowest address allowed
4486 for use by the bootm command. See also "bootm_size"
4487 environment variable. Address defined by "bootm_low" is
4488 also the base of the initial memory mapping for the Linux
4489 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4492 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4493 This variable is given as a hexadecimal number and it
4494 defines the size of the memory region starting at base
4495 address bootm_low that is accessible by the Linux kernel
4496 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4497 as the default value if it is defined, and bootm_size is
4500 bootm_size - Memory range available for image processing in the bootm
4501 command can be restricted. This variable is given as
4502 a hexadecimal number and defines the size of the region
4503 allowed for use by the bootm command. See also "bootm_low"
4504 environment variable.
4506 updatefile - Location of the software update file on a TFTP server, used
4507 by the automatic software update feature. Please refer to
4508 documentation in doc/README.update for more details.
4510 autoload - if set to "no" (any string beginning with 'n'),
4511 "bootp" will just load perform a lookup of the
4512 configuration from the BOOTP server, but not try to
4513 load any image using TFTP
4515 autostart - if set to "yes", an image loaded using the "bootp",
4516 "rarpboot", "tftpboot" or "diskboot" commands will
4517 be automatically started (by internally calling
4520 If set to "no", a standalone image passed to the
4521 "bootm" command will be copied to the load address
4522 (and eventually uncompressed), but NOT be started.
4523 This can be used to load and uncompress arbitrary
4526 fdt_high - if set this restricts the maximum address that the
4527 flattened device tree will be copied into upon boot.
4528 For example, if you have a system with 1 GB memory
4529 at physical address 0x10000000, while Linux kernel
4530 only recognizes the first 704 MB as low memory, you
4531 may need to set fdt_high as 0x3C000000 to have the
4532 device tree blob be copied to the maximum address
4533 of the 704 MB low memory, so that Linux kernel can
4534 access it during the boot procedure.
4536 If this is set to the special value 0xFFFFFFFF then
4537 the fdt will not be copied at all on boot. For this
4538 to work it must reside in writable memory, have
4539 sufficient padding on the end of it for u-boot to
4540 add the information it needs into it, and the memory
4541 must be accessible by the kernel.
4543 fdtcontroladdr- if set this is the address of the control flattened
4544 device tree used by U-Boot when CONFIG_OF_CONTROL is
4547 i2cfast - (PPC405GP|PPC405EP only)
4548 if set to 'y' configures Linux I2C driver for fast
4549 mode (400kHZ). This environment variable is used in
4550 initialization code. So, for changes to be effective
4551 it must be saved and board must be reset.
4553 initrd_high - restrict positioning of initrd images:
4554 If this variable is not set, initrd images will be
4555 copied to the highest possible address in RAM; this
4556 is usually what you want since it allows for
4557 maximum initrd size. If for some reason you want to
4558 make sure that the initrd image is loaded below the
4559 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4560 variable to a value of "no" or "off" or "0".
4561 Alternatively, you can set it to a maximum upper
4562 address to use (U-Boot will still check that it
4563 does not overwrite the U-Boot stack and data).
4565 For instance, when you have a system with 16 MB
4566 RAM, and want to reserve 4 MB from use by Linux,
4567 you can do this by adding "mem=12M" to the value of
4568 the "bootargs" variable. However, now you must make
4569 sure that the initrd image is placed in the first
4570 12 MB as well - this can be done with
4572 setenv initrd_high 00c00000
4574 If you set initrd_high to 0xFFFFFFFF, this is an
4575 indication to U-Boot that all addresses are legal
4576 for the Linux kernel, including addresses in flash
4577 memory. In this case U-Boot will NOT COPY the
4578 ramdisk at all. This may be useful to reduce the
4579 boot time on your system, but requires that this
4580 feature is supported by your Linux kernel.
4582 ipaddr - IP address; needed for tftpboot command
4584 loadaddr - Default load address for commands like "bootp",
4585 "rarpboot", "tftpboot", "loadb" or "diskboot"
4587 loads_echo - see CONFIG_LOADS_ECHO
4589 serverip - TFTP server IP address; needed for tftpboot command
4591 bootretry - see CONFIG_BOOT_RETRY_TIME
4593 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4595 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4597 ethprime - controls which interface is used first.
4599 ethact - controls which interface is currently active.
4600 For example you can do the following
4602 => setenv ethact FEC
4603 => ping 192.168.0.1 # traffic sent on FEC
4604 => setenv ethact SCC
4605 => ping 10.0.0.1 # traffic sent on SCC
4607 ethrotate - When set to "no" U-Boot does not go through all
4608 available network interfaces.
4609 It just stays at the currently selected interface.
4611 netretry - When set to "no" each network operation will
4612 either succeed or fail without retrying.
4613 When set to "once" the network operation will
4614 fail when all the available network interfaces
4615 are tried once without success.
4616 Useful on scripts which control the retry operation
4619 npe_ucode - set load address for the NPE microcode
4621 silent_linux - If set then Linux will be told to boot silently, by
4622 changing the console to be empty. If "yes" it will be
4623 made silent. If "no" it will not be made silent. If
4624 unset, then it will be made silent if the U-Boot console
4627 tftpsrcp - If this is set, the value is used for TFTP's
4630 tftpdstp - If this is set, the value is used for TFTP's UDP
4631 destination port instead of the Well Know Port 69.
4633 tftpblocksize - Block size to use for TFTP transfers; if not set,
4634 we use the TFTP server's default block size
4636 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4637 seconds, minimum value is 1000 = 1 second). Defines
4638 when a packet is considered to be lost so it has to
4639 be retransmitted. The default is 5000 = 5 seconds.
4640 Lowering this value may make downloads succeed
4641 faster in networks with high packet loss rates or
4642 with unreliable TFTP servers.
4644 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4645 unit, minimum value = 0). Defines how many timeouts
4646 can happen during a single file transfer before that
4647 transfer is aborted. The default is 10, and 0 means
4648 'no timeouts allowed'. Increasing this value may help
4649 downloads succeed with high packet loss rates, or with
4650 unreliable TFTP servers or client hardware.
4652 vlan - When set to a value < 4095 the traffic over
4653 Ethernet is encapsulated/received over 802.1q
4656 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4657 Unsigned value, in milliseconds. If not set, the period will
4658 be either the default (28000), or a value based on
4659 CONFIG_NET_RETRY_COUNT, if defined. This value has
4660 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4662 The following image location variables contain the location of images
4663 used in booting. The "Image" column gives the role of the image and is
4664 not an environment variable name. The other columns are environment
4665 variable names. "File Name" gives the name of the file on a TFTP
4666 server, "RAM Address" gives the location in RAM the image will be
4667 loaded to, and "Flash Location" gives the image's address in NOR
4668 flash or offset in NAND flash.
4670 *Note* - these variables don't have to be defined for all boards, some
4671 boards currently use other variables for these purposes, and some
4672 boards use these variables for other purposes.
4674 Image File Name RAM Address Flash Location
4675 ----- --------- ----------- --------------
4676 u-boot u-boot u-boot_addr_r u-boot_addr
4677 Linux kernel bootfile kernel_addr_r kernel_addr
4678 device tree blob fdtfile fdt_addr_r fdt_addr
4679 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4681 The following environment variables may be used and automatically
4682 updated by the network boot commands ("bootp" and "rarpboot"),
4683 depending the information provided by your boot server:
4685 bootfile - see above
4686 dnsip - IP address of your Domain Name Server
4687 dnsip2 - IP address of your secondary Domain Name Server
4688 gatewayip - IP address of the Gateway (Router) to use
4689 hostname - Target hostname
4691 netmask - Subnet Mask
4692 rootpath - Pathname of the root filesystem on the NFS server
4693 serverip - see above
4696 There are two special Environment Variables:
4698 serial# - contains hardware identification information such
4699 as type string and/or serial number
4700 ethaddr - Ethernet address
4702 These variables can be set only once (usually during manufacturing of
4703 the board). U-Boot refuses to delete or overwrite these variables
4704 once they have been set once.
4707 Further special Environment Variables:
4709 ver - Contains the U-Boot version string as printed
4710 with the "version" command. This variable is
4711 readonly (see CONFIG_VERSION_VARIABLE).
4714 Please note that changes to some configuration parameters may take
4715 only effect after the next boot (yes, that's just like Windoze :-).
4718 Callback functions for environment variables:
4719 ---------------------------------------------
4721 For some environment variables, the behavior of u-boot needs to change
4722 when their values are changed. This functionality allows functions to
4723 be associated with arbitrary variables. On creation, overwrite, or
4724 deletion, the callback will provide the opportunity for some side
4725 effect to happen or for the change to be rejected.
4727 The callbacks are named and associated with a function using the
4728 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4730 These callbacks are associated with variables in one of two ways. The
4731 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4732 in the board configuration to a string that defines a list of
4733 associations. The list must be in the following format:
4735 entry = variable_name[:callback_name]
4738 If the callback name is not specified, then the callback is deleted.
4739 Spaces are also allowed anywhere in the list.
4741 Callbacks can also be associated by defining the ".callbacks" variable
4742 with the same list format above. Any association in ".callbacks" will
4743 override any association in the static list. You can define
4744 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4745 ".callbacks" environment variable in the default or embedded environment.
4747 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4748 regular expression. This allows multiple variables to be connected to
4749 the same callback without explicitly listing them all out.
4752 Command Line Parsing:
4753 =====================
4755 There are two different command line parsers available with U-Boot:
4756 the old "simple" one, and the much more powerful "hush" shell:
4758 Old, simple command line parser:
4759 --------------------------------
4761 - supports environment variables (through setenv / saveenv commands)
4762 - several commands on one line, separated by ';'
4763 - variable substitution using "... ${name} ..." syntax
4764 - special characters ('$', ';') can be escaped by prefixing with '\',
4766 setenv bootcmd bootm \${address}
4767 - You can also escape text by enclosing in single apostrophes, for example:
4768 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4773 - similar to Bourne shell, with control structures like
4774 if...then...else...fi, for...do...done; while...do...done,
4775 until...do...done, ...
4776 - supports environment ("global") variables (through setenv / saveenv
4777 commands) and local shell variables (through standard shell syntax
4778 "name=value"); only environment variables can be used with "run"
4784 (1) If a command line (or an environment variable executed by a "run"
4785 command) contains several commands separated by semicolon, and
4786 one of these commands fails, then the remaining commands will be
4789 (2) If you execute several variables with one call to run (i. e.
4790 calling run with a list of variables as arguments), any failing
4791 command will cause "run" to terminate, i. e. the remaining
4792 variables are not executed.
4794 Note for Redundant Ethernet Interfaces:
4795 =======================================
4797 Some boards come with redundant Ethernet interfaces; U-Boot supports
4798 such configurations and is capable of automatic selection of a
4799 "working" interface when needed. MAC assignment works as follows:
4801 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4802 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4803 "eth1addr" (=>eth1), "eth2addr", ...
4805 If the network interface stores some valid MAC address (for instance
4806 in SROM), this is used as default address if there is NO correspon-
4807 ding setting in the environment; if the corresponding environment
4808 variable is set, this overrides the settings in the card; that means:
4810 o If the SROM has a valid MAC address, and there is no address in the
4811 environment, the SROM's address is used.
4813 o If there is no valid address in the SROM, and a definition in the
4814 environment exists, then the value from the environment variable is
4817 o If both the SROM and the environment contain a MAC address, and
4818 both addresses are the same, this MAC address is used.
4820 o If both the SROM and the environment contain a MAC address, and the
4821 addresses differ, the value from the environment is used and a
4824 o If neither SROM nor the environment contain a MAC address, an error
4825 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4826 a random, locally-assigned MAC is used.
4828 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4829 will be programmed into hardware as part of the initialization process. This
4830 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4831 The naming convention is as follows:
4832 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4837 U-Boot is capable of booting (and performing other auxiliary operations on)
4838 images in two formats:
4840 New uImage format (FIT)
4841 -----------------------
4843 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4844 to Flattened Device Tree). It allows the use of images with multiple
4845 components (several kernels, ramdisks, etc.), with contents protected by
4846 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4852 Old image format is based on binary files which can be basically anything,
4853 preceded by a special header; see the definitions in include/image.h for
4854 details; basically, the header defines the following image properties:
4856 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4857 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4858 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4859 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4861 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4862 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4863 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4864 * Compression Type (uncompressed, gzip, bzip2)
4870 The header is marked by a special Magic Number, and both the header
4871 and the data portions of the image are secured against corruption by
4878 Although U-Boot should support any OS or standalone application
4879 easily, the main focus has always been on Linux during the design of
4882 U-Boot includes many features that so far have been part of some
4883 special "boot loader" code within the Linux kernel. Also, any
4884 "initrd" images to be used are no longer part of one big Linux image;
4885 instead, kernel and "initrd" are separate images. This implementation
4886 serves several purposes:
4888 - the same features can be used for other OS or standalone
4889 applications (for instance: using compressed images to reduce the
4890 Flash memory footprint)
4892 - it becomes much easier to port new Linux kernel versions because
4893 lots of low-level, hardware dependent stuff are done by U-Boot
4895 - the same Linux kernel image can now be used with different "initrd"
4896 images; of course this also means that different kernel images can
4897 be run with the same "initrd". This makes testing easier (you don't
4898 have to build a new "zImage.initrd" Linux image when you just
4899 change a file in your "initrd"). Also, a field-upgrade of the
4900 software is easier now.
4906 Porting Linux to U-Boot based systems:
4907 ---------------------------------------
4909 U-Boot cannot save you from doing all the necessary modifications to
4910 configure the Linux device drivers for use with your target hardware
4911 (no, we don't intend to provide a full virtual machine interface to
4914 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4916 Just make sure your machine specific header file (for instance
4917 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4918 Information structure as we define in include/asm-<arch>/u-boot.h,
4919 and make sure that your definition of IMAP_ADDR uses the same value
4920 as your U-Boot configuration in CONFIG_SYS_IMMR.
4922 Note that U-Boot now has a driver model, a unified model for drivers.
4923 If you are adding a new driver, plumb it into driver model. If there
4924 is no uclass available, you are encouraged to create one. See
4928 Configuring the Linux kernel:
4929 -----------------------------
4931 No specific requirements for U-Boot. Make sure you have some root
4932 device (initial ramdisk, NFS) for your target system.
4935 Building a Linux Image:
4936 -----------------------
4938 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4939 not used. If you use recent kernel source, a new build target
4940 "uImage" will exist which automatically builds an image usable by
4941 U-Boot. Most older kernels also have support for a "pImage" target,
4942 which was introduced for our predecessor project PPCBoot and uses a
4943 100% compatible format.
4947 make TQM850L_defconfig
4952 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4953 encapsulate a compressed Linux kernel image with header information,
4954 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4956 * build a standard "vmlinux" kernel image (in ELF binary format):
4958 * convert the kernel into a raw binary image:
4960 ${CROSS_COMPILE}-objcopy -O binary \
4961 -R .note -R .comment \
4962 -S vmlinux linux.bin
4964 * compress the binary image:
4968 * package compressed binary image for U-Boot:
4970 mkimage -A ppc -O linux -T kernel -C gzip \
4971 -a 0 -e 0 -n "Linux Kernel Image" \
4972 -d linux.bin.gz uImage
4975 The "mkimage" tool can also be used to create ramdisk images for use
4976 with U-Boot, either separated from the Linux kernel image, or
4977 combined into one file. "mkimage" encapsulates the images with a 64
4978 byte header containing information about target architecture,
4979 operating system, image type, compression method, entry points, time
4980 stamp, CRC32 checksums, etc.
4982 "mkimage" can be called in two ways: to verify existing images and
4983 print the header information, or to build new images.
4985 In the first form (with "-l" option) mkimage lists the information
4986 contained in the header of an existing U-Boot image; this includes
4987 checksum verification:
4989 tools/mkimage -l image
4990 -l ==> list image header information
4992 The second form (with "-d" option) is used to build a U-Boot image
4993 from a "data file" which is used as image payload:
4995 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4996 -n name -d data_file image
4997 -A ==> set architecture to 'arch'
4998 -O ==> set operating system to 'os'
4999 -T ==> set image type to 'type'
5000 -C ==> set compression type 'comp'
5001 -a ==> set load address to 'addr' (hex)
5002 -e ==> set entry point to 'ep' (hex)
5003 -n ==> set image name to 'name'
5004 -d ==> use image data from 'datafile'
5006 Right now, all Linux kernels for PowerPC systems use the same load
5007 address (0x00000000), but the entry point address depends on the
5010 - 2.2.x kernels have the entry point at 0x0000000C,
5011 - 2.3.x and later kernels have the entry point at 0x00000000.
5013 So a typical call to build a U-Boot image would read:
5015 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5016 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5017 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5018 > examples/uImage.TQM850L
5019 Image Name: 2.4.4 kernel for TQM850L
5020 Created: Wed Jul 19 02:34:59 2000
5021 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5022 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5023 Load Address: 0x00000000
5024 Entry Point: 0x00000000
5026 To verify the contents of the image (or check for corruption):
5028 -> tools/mkimage -l examples/uImage.TQM850L
5029 Image Name: 2.4.4 kernel for TQM850L
5030 Created: Wed Jul 19 02:34:59 2000
5031 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5032 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5033 Load Address: 0x00000000
5034 Entry Point: 0x00000000
5036 NOTE: for embedded systems where boot time is critical you can trade
5037 speed for memory and install an UNCOMPRESSED image instead: this
5038 needs more space in Flash, but boots much faster since it does not
5039 need to be uncompressed:
5041 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5042 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5043 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5044 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5045 > examples/uImage.TQM850L-uncompressed
5046 Image Name: 2.4.4 kernel for TQM850L
5047 Created: Wed Jul 19 02:34:59 2000
5048 Image Type: PowerPC Linux Kernel Image (uncompressed)
5049 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5050 Load Address: 0x00000000
5051 Entry Point: 0x00000000
5054 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5055 when your kernel is intended to use an initial ramdisk:
5057 -> tools/mkimage -n 'Simple Ramdisk Image' \
5058 > -A ppc -O linux -T ramdisk -C gzip \
5059 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5060 Image Name: Simple Ramdisk Image
5061 Created: Wed Jan 12 14:01:50 2000
5062 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5063 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5064 Load Address: 0x00000000
5065 Entry Point: 0x00000000
5067 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5068 option performs the converse operation of the mkimage's second form (the "-d"
5069 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5072 tools/dumpimage -i image -T type -p position data_file
5073 -i ==> extract from the 'image' a specific 'data_file'
5074 -T ==> set image type to 'type'
5075 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5078 Installing a Linux Image:
5079 -------------------------
5081 To downloading a U-Boot image over the serial (console) interface,
5082 you must convert the image to S-Record format:
5084 objcopy -I binary -O srec examples/image examples/image.srec
5086 The 'objcopy' does not understand the information in the U-Boot
5087 image header, so the resulting S-Record file will be relative to
5088 address 0x00000000. To load it to a given address, you need to
5089 specify the target address as 'offset' parameter with the 'loads'
5092 Example: install the image to address 0x40100000 (which on the
5093 TQM8xxL is in the first Flash bank):
5095 => erase 40100000 401FFFFF
5101 ## Ready for S-Record download ...
5102 ~>examples/image.srec
5103 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5105 15989 15990 15991 15992
5106 [file transfer complete]
5108 ## Start Addr = 0x00000000
5111 You can check the success of the download using the 'iminfo' command;
5112 this includes a checksum verification so you can be sure no data
5113 corruption happened:
5117 ## Checking Image at 40100000 ...
5118 Image Name: 2.2.13 for initrd on TQM850L
5119 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5120 Data Size: 335725 Bytes = 327 kB = 0 MB
5121 Load Address: 00000000
5122 Entry Point: 0000000c
5123 Verifying Checksum ... OK
5129 The "bootm" command is used to boot an application that is stored in
5130 memory (RAM or Flash). In case of a Linux kernel image, the contents
5131 of the "bootargs" environment variable is passed to the kernel as
5132 parameters. You can check and modify this variable using the
5133 "printenv" and "setenv" commands:
5136 => printenv bootargs
5137 bootargs=root=/dev/ram
5139 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5141 => printenv bootargs
5142 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5145 ## Booting Linux kernel at 40020000 ...
5146 Image Name: 2.2.13 for NFS on TQM850L
5147 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5148 Data Size: 381681 Bytes = 372 kB = 0 MB
5149 Load Address: 00000000
5150 Entry Point: 0000000c
5151 Verifying Checksum ... OK
5152 Uncompressing Kernel Image ... OK
5153 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
5154 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5155 time_init: decrementer frequency = 187500000/60
5156 Calibrating delay loop... 49.77 BogoMIPS
5157 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5160 If you want to boot a Linux kernel with initial RAM disk, you pass
5161 the memory addresses of both the kernel and the initrd image (PPBCOOT
5162 format!) to the "bootm" command:
5164 => imi 40100000 40200000
5166 ## Checking Image at 40100000 ...
5167 Image Name: 2.2.13 for initrd on TQM850L
5168 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5169 Data Size: 335725 Bytes = 327 kB = 0 MB
5170 Load Address: 00000000
5171 Entry Point: 0000000c
5172 Verifying Checksum ... OK
5174 ## Checking Image at 40200000 ...
5175 Image Name: Simple Ramdisk Image
5176 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5177 Data Size: 566530 Bytes = 553 kB = 0 MB
5178 Load Address: 00000000
5179 Entry Point: 00000000
5180 Verifying Checksum ... OK
5182 => bootm 40100000 40200000
5183 ## Booting Linux kernel at 40100000 ...
5184 Image Name: 2.2.13 for initrd on TQM850L
5185 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5186 Data Size: 335725 Bytes = 327 kB = 0 MB
5187 Load Address: 00000000
5188 Entry Point: 0000000c
5189 Verifying Checksum ... OK
5190 Uncompressing Kernel Image ... OK
5191 ## Loading RAMDisk Image at 40200000 ...
5192 Image Name: Simple Ramdisk Image
5193 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5194 Data Size: 566530 Bytes = 553 kB = 0 MB
5195 Load Address: 00000000
5196 Entry Point: 00000000
5197 Verifying Checksum ... OK
5198 Loading Ramdisk ... OK
5199 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
5200 Boot arguments: root=/dev/ram
5201 time_init: decrementer frequency = 187500000/60
5202 Calibrating delay loop... 49.77 BogoMIPS
5204 RAMDISK: Compressed image found at block 0
5205 VFS: Mounted root (ext2 filesystem).
5209 Boot Linux and pass a flat device tree:
5212 First, U-Boot must be compiled with the appropriate defines. See the section
5213 titled "Linux Kernel Interface" above for a more in depth explanation. The
5214 following is an example of how to start a kernel and pass an updated
5220 oft=oftrees/mpc8540ads.dtb
5221 => tftp $oftaddr $oft
5222 Speed: 1000, full duplex
5224 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5225 Filename 'oftrees/mpc8540ads.dtb'.
5226 Load address: 0x300000
5229 Bytes transferred = 4106 (100a hex)
5230 => tftp $loadaddr $bootfile
5231 Speed: 1000, full duplex
5233 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5235 Load address: 0x200000
5236 Loading:############
5238 Bytes transferred = 1029407 (fb51f hex)
5243 => bootm $loadaddr - $oftaddr
5244 ## Booting image at 00200000 ...
5245 Image Name: Linux-2.6.17-dirty
5246 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5247 Data Size: 1029343 Bytes = 1005.2 kB
5248 Load Address: 00000000
5249 Entry Point: 00000000
5250 Verifying Checksum ... OK
5251 Uncompressing Kernel Image ... OK
5252 Booting using flat device tree at 0x300000
5253 Using MPC85xx ADS machine description
5254 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5258 More About U-Boot Image Types:
5259 ------------------------------
5261 U-Boot supports the following image types:
5263 "Standalone Programs" are directly runnable in the environment
5264 provided by U-Boot; it is expected that (if they behave
5265 well) you can continue to work in U-Boot after return from
5266 the Standalone Program.
5267 "OS Kernel Images" are usually images of some Embedded OS which
5268 will take over control completely. Usually these programs
5269 will install their own set of exception handlers, device
5270 drivers, set up the MMU, etc. - this means, that you cannot
5271 expect to re-enter U-Boot except by resetting the CPU.
5272 "RAMDisk Images" are more or less just data blocks, and their
5273 parameters (address, size) are passed to an OS kernel that is
5275 "Multi-File Images" contain several images, typically an OS
5276 (Linux) kernel image and one or more data images like
5277 RAMDisks. This construct is useful for instance when you want
5278 to boot over the network using BOOTP etc., where the boot
5279 server provides just a single image file, but you want to get
5280 for instance an OS kernel and a RAMDisk image.
5282 "Multi-File Images" start with a list of image sizes, each
5283 image size (in bytes) specified by an "uint32_t" in network
5284 byte order. This list is terminated by an "(uint32_t)0".
5285 Immediately after the terminating 0 follow the images, one by
5286 one, all aligned on "uint32_t" boundaries (size rounded up to
5287 a multiple of 4 bytes).
5289 "Firmware Images" are binary images containing firmware (like
5290 U-Boot or FPGA images) which usually will be programmed to
5293 "Script files" are command sequences that will be executed by
5294 U-Boot's command interpreter; this feature is especially
5295 useful when you configure U-Boot to use a real shell (hush)
5296 as command interpreter.
5298 Booting the Linux zImage:
5299 -------------------------
5301 On some platforms, it's possible to boot Linux zImage. This is done
5302 using the "bootz" command. The syntax of "bootz" command is the same
5303 as the syntax of "bootm" command.
5305 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5306 kernel with raw initrd images. The syntax is slightly different, the
5307 address of the initrd must be augmented by it's size, in the following
5308 format: "<initrd addres>:<initrd size>".
5314 One of the features of U-Boot is that you can dynamically load and
5315 run "standalone" applications, which can use some resources of
5316 U-Boot like console I/O functions or interrupt services.
5318 Two simple examples are included with the sources:
5323 'examples/hello_world.c' contains a small "Hello World" Demo
5324 application; it is automatically compiled when you build U-Boot.
5325 It's configured to run at address 0x00040004, so you can play with it
5329 ## Ready for S-Record download ...
5330 ~>examples/hello_world.srec
5331 1 2 3 4 5 6 7 8 9 10 11 ...
5332 [file transfer complete]
5334 ## Start Addr = 0x00040004
5336 => go 40004 Hello World! This is a test.
5337 ## Starting application at 0x00040004 ...
5348 Hit any key to exit ...
5350 ## Application terminated, rc = 0x0
5352 Another example, which demonstrates how to register a CPM interrupt
5353 handler with the U-Boot code, can be found in 'examples/timer.c'.
5354 Here, a CPM timer is set up to generate an interrupt every second.
5355 The interrupt service routine is trivial, just printing a '.'
5356 character, but this is just a demo program. The application can be
5357 controlled by the following keys:
5359 ? - print current values og the CPM Timer registers
5360 b - enable interrupts and start timer
5361 e - stop timer and disable interrupts
5362 q - quit application
5365 ## Ready for S-Record download ...
5366 ~>examples/timer.srec
5367 1 2 3 4 5 6 7 8 9 10 11 ...
5368 [file transfer complete]
5370 ## Start Addr = 0x00040004
5373 ## Starting application at 0x00040004 ...
5376 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5379 [q, b, e, ?] Set interval 1000000 us
5382 [q, b, e, ?] ........
5383 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5386 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5389 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5392 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5394 [q, b, e, ?] ...Stopping timer
5396 [q, b, e, ?] ## Application terminated, rc = 0x0
5402 Over time, many people have reported problems when trying to use the
5403 "minicom" terminal emulation program for serial download. I (wd)
5404 consider minicom to be broken, and recommend not to use it. Under
5405 Unix, I recommend to use C-Kermit for general purpose use (and
5406 especially for kermit binary protocol download ("loadb" command), and
5407 use "cu" for S-Record download ("loads" command). See
5408 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5409 for help with kermit.
5412 Nevertheless, if you absolutely want to use it try adding this
5413 configuration to your "File transfer protocols" section:
5415 Name Program Name U/D FullScr IO-Red. Multi
5416 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5417 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5423 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5424 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5426 Building requires a cross environment; it is known to work on
5427 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5428 need gmake since the Makefiles are not compatible with BSD make).
5429 Note that the cross-powerpc package does not install include files;
5430 attempting to build U-Boot will fail because <machine/ansi.h> is
5431 missing. This file has to be installed and patched manually:
5433 # cd /usr/pkg/cross/powerpc-netbsd/include
5435 # ln -s powerpc machine
5436 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5437 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5439 Native builds *don't* work due to incompatibilities between native
5440 and U-Boot include files.
5442 Booting assumes that (the first part of) the image booted is a
5443 stage-2 loader which in turn loads and then invokes the kernel
5444 proper. Loader sources will eventually appear in the NetBSD source
5445 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5446 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5449 Implementation Internals:
5450 =========================
5452 The following is not intended to be a complete description of every
5453 implementation detail. However, it should help to understand the
5454 inner workings of U-Boot and make it easier to port it to custom
5458 Initial Stack, Global Data:
5459 ---------------------------
5461 The implementation of U-Boot is complicated by the fact that U-Boot
5462 starts running out of ROM (flash memory), usually without access to
5463 system RAM (because the memory controller is not initialized yet).
5464 This means that we don't have writable Data or BSS segments, and BSS
5465 is not initialized as zero. To be able to get a C environment working
5466 at all, we have to allocate at least a minimal stack. Implementation
5467 options for this are defined and restricted by the CPU used: Some CPU
5468 models provide on-chip memory (like the IMMR area on MPC8xx and
5469 MPC826x processors), on others (parts of) the data cache can be
5470 locked as (mis-) used as memory, etc.
5472 Chris Hallinan posted a good summary of these issues to the
5473 U-Boot mailing list:
5475 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5476 From: "Chris Hallinan" <clh@net1plus.com>
5477 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5480 Correct me if I'm wrong, folks, but the way I understand it
5481 is this: Using DCACHE as initial RAM for Stack, etc, does not
5482 require any physical RAM backing up the cache. The cleverness
5483 is that the cache is being used as a temporary supply of
5484 necessary storage before the SDRAM controller is setup. It's
5485 beyond the scope of this list to explain the details, but you
5486 can see how this works by studying the cache architecture and
5487 operation in the architecture and processor-specific manuals.
5489 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5490 is another option for the system designer to use as an
5491 initial stack/RAM area prior to SDRAM being available. Either
5492 option should work for you. Using CS 4 should be fine if your
5493 board designers haven't used it for something that would
5494 cause you grief during the initial boot! It is frequently not
5497 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5498 with your processor/board/system design. The default value
5499 you will find in any recent u-boot distribution in
5500 walnut.h should work for you. I'd set it to a value larger
5501 than your SDRAM module. If you have a 64MB SDRAM module, set
5502 it above 400_0000. Just make sure your board has no resources
5503 that are supposed to respond to that address! That code in
5504 start.S has been around a while and should work as is when
5505 you get the config right.
5510 It is essential to remember this, since it has some impact on the C
5511 code for the initialization procedures:
5513 * Initialized global data (data segment) is read-only. Do not attempt
5516 * Do not use any uninitialized global data (or implicitly initialized
5517 as zero data - BSS segment) at all - this is undefined, initiali-
5518 zation is performed later (when relocating to RAM).
5520 * Stack space is very limited. Avoid big data buffers or things like
5523 Having only the stack as writable memory limits means we cannot use
5524 normal global data to share information between the code. But it
5525 turned out that the implementation of U-Boot can be greatly
5526 simplified by making a global data structure (gd_t) available to all
5527 functions. We could pass a pointer to this data as argument to _all_
5528 functions, but this would bloat the code. Instead we use a feature of
5529 the GCC compiler (Global Register Variables) to share the data: we
5530 place a pointer (gd) to the global data into a register which we
5531 reserve for this purpose.
5533 When choosing a register for such a purpose we are restricted by the
5534 relevant (E)ABI specifications for the current architecture, and by
5535 GCC's implementation.
5537 For PowerPC, the following registers have specific use:
5539 R2: reserved for system use
5540 R3-R4: parameter passing and return values
5541 R5-R10: parameter passing
5542 R13: small data area pointer
5546 (U-Boot also uses R12 as internal GOT pointer. r12
5547 is a volatile register so r12 needs to be reset when
5548 going back and forth between asm and C)
5550 ==> U-Boot will use R2 to hold a pointer to the global data
5552 Note: on PPC, we could use a static initializer (since the
5553 address of the global data structure is known at compile time),
5554 but it turned out that reserving a register results in somewhat
5555 smaller code - although the code savings are not that big (on
5556 average for all boards 752 bytes for the whole U-Boot image,
5557 624 text + 127 data).
5559 On ARM, the following registers are used:
5561 R0: function argument word/integer result
5562 R1-R3: function argument word
5563 R9: platform specific
5564 R10: stack limit (used only if stack checking is enabled)
5565 R11: argument (frame) pointer
5566 R12: temporary workspace
5569 R15: program counter
5571 ==> U-Boot will use R9 to hold a pointer to the global data
5573 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5575 On Nios II, the ABI is documented here:
5576 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5578 ==> U-Boot will use gp to hold a pointer to the global data
5580 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5581 to access small data sections, so gp is free.
5583 On NDS32, the following registers are used:
5585 R0-R1: argument/return
5587 R15: temporary register for assembler
5588 R16: trampoline register
5589 R28: frame pointer (FP)
5590 R29: global pointer (GP)
5591 R30: link register (LP)
5592 R31: stack pointer (SP)
5593 PC: program counter (PC)
5595 ==> U-Boot will use R10 to hold a pointer to the global data
5597 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5598 or current versions of GCC may "optimize" the code too much.
5603 U-Boot runs in system state and uses physical addresses, i.e. the
5604 MMU is not used either for address mapping nor for memory protection.
5606 The available memory is mapped to fixed addresses using the memory
5607 controller. In this process, a contiguous block is formed for each
5608 memory type (Flash, SDRAM, SRAM), even when it consists of several
5609 physical memory banks.
5611 U-Boot is installed in the first 128 kB of the first Flash bank (on
5612 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5613 booting and sizing and initializing DRAM, the code relocates itself
5614 to the upper end of DRAM. Immediately below the U-Boot code some
5615 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5616 configuration setting]. Below that, a structure with global Board
5617 Info data is placed, followed by the stack (growing downward).
5619 Additionally, some exception handler code is copied to the low 8 kB
5620 of DRAM (0x00000000 ... 0x00001FFF).
5622 So a typical memory configuration with 16 MB of DRAM could look like
5625 0x0000 0000 Exception Vector code
5628 0x0000 2000 Free for Application Use
5634 0x00FB FF20 Monitor Stack (Growing downward)
5635 0x00FB FFAC Board Info Data and permanent copy of global data
5636 0x00FC 0000 Malloc Arena
5639 0x00FE 0000 RAM Copy of Monitor Code
5640 ... eventually: LCD or video framebuffer
5641 ... eventually: pRAM (Protected RAM - unchanged by reset)
5642 0x00FF FFFF [End of RAM]
5645 System Initialization:
5646 ----------------------
5648 In the reset configuration, U-Boot starts at the reset entry point
5649 (on most PowerPC systems at address 0x00000100). Because of the reset
5650 configuration for CS0# this is a mirror of the on board Flash memory.
5651 To be able to re-map memory U-Boot then jumps to its link address.
5652 To be able to implement the initialization code in C, a (small!)
5653 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5654 which provide such a feature like), or in a locked part of the data
5655 cache. After that, U-Boot initializes the CPU core, the caches and
5658 Next, all (potentially) available memory banks are mapped using a
5659 preliminary mapping. For example, we put them on 512 MB boundaries
5660 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5661 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5662 programmed for SDRAM access. Using the temporary configuration, a
5663 simple memory test is run that determines the size of the SDRAM
5666 When there is more than one SDRAM bank, and the banks are of
5667 different size, the largest is mapped first. For equal size, the first
5668 bank (CS2#) is mapped first. The first mapping is always for address
5669 0x00000000, with any additional banks following immediately to create
5670 contiguous memory starting from 0.
5672 Then, the monitor installs itself at the upper end of the SDRAM area
5673 and allocates memory for use by malloc() and for the global Board
5674 Info data; also, the exception vector code is copied to the low RAM
5675 pages, and the final stack is set up.
5677 Only after this relocation will you have a "normal" C environment;
5678 until that you are restricted in several ways, mostly because you are
5679 running from ROM, and because the code will have to be relocated to a
5683 U-Boot Porting Guide:
5684 ----------------------
5686 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5690 int main(int argc, char *argv[])
5692 sighandler_t no_more_time;
5694 signal(SIGALRM, no_more_time);
5695 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5697 if (available_money > available_manpower) {
5698 Pay consultant to port U-Boot;
5702 Download latest U-Boot source;
5704 Subscribe to u-boot mailing list;
5707 email("Hi, I am new to U-Boot, how do I get started?");
5710 Read the README file in the top level directory;
5711 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5712 Read applicable doc/*.README;
5713 Read the source, Luke;
5714 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5717 if (available_money > toLocalCurrency ($2500))
5720 Add a lot of aggravation and time;
5722 if (a similar board exists) { /* hopefully... */
5723 cp -a board/<similar> board/<myboard>
5724 cp include/configs/<similar>.h include/configs/<myboard>.h
5726 Create your own board support subdirectory;
5727 Create your own board include/configs/<myboard>.h file;
5729 Edit new board/<myboard> files
5730 Edit new include/configs/<myboard>.h
5735 Add / modify source code;
5739 email("Hi, I am having problems...");
5741 Send patch file to the U-Boot email list;
5742 if (reasonable critiques)
5743 Incorporate improvements from email list code review;
5745 Defend code as written;
5751 void no_more_time (int sig)
5760 All contributions to U-Boot should conform to the Linux kernel
5761 coding style; see the file "Documentation/CodingStyle" and the script
5762 "scripts/Lindent" in your Linux kernel source directory.
5764 Source files originating from a different project (for example the
5765 MTD subsystem) are generally exempt from these guidelines and are not
5766 reformatted to ease subsequent migration to newer versions of those
5769 Please note that U-Boot is implemented in C (and to some small parts in
5770 Assembler); no C++ is used, so please do not use C++ style comments (//)
5773 Please also stick to the following formatting rules:
5774 - remove any trailing white space
5775 - use TAB characters for indentation and vertical alignment, not spaces
5776 - make sure NOT to use DOS '\r\n' line feeds
5777 - do not add more than 2 consecutive empty lines to source files
5778 - do not add trailing empty lines to source files
5780 Submissions which do not conform to the standards may be returned
5781 with a request to reformat the changes.
5787 Since the number of patches for U-Boot is growing, we need to
5788 establish some rules. Submissions which do not conform to these rules
5789 may be rejected, even when they contain important and valuable stuff.
5791 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5793 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5794 see http://lists.denx.de/mailman/listinfo/u-boot
5796 When you send a patch, please include the following information with
5799 * For bug fixes: a description of the bug and how your patch fixes
5800 this bug. Please try to include a way of demonstrating that the
5801 patch actually fixes something.
5803 * For new features: a description of the feature and your
5806 * A CHANGELOG entry as plaintext (separate from the patch)
5808 * For major contributions, add a MAINTAINERS file with your
5809 information and associated file and directory references.
5811 * When you add support for a new board, don't forget to add a
5812 maintainer e-mail address to the boards.cfg file, too.
5814 * If your patch adds new configuration options, don't forget to
5815 document these in the README file.
5817 * The patch itself. If you are using git (which is *strongly*
5818 recommended) you can easily generate the patch using the
5819 "git format-patch". If you then use "git send-email" to send it to
5820 the U-Boot mailing list, you will avoid most of the common problems
5821 with some other mail clients.
5823 If you cannot use git, use "diff -purN OLD NEW". If your version of
5824 diff does not support these options, then get the latest version of
5827 The current directory when running this command shall be the parent
5828 directory of the U-Boot source tree (i. e. please make sure that
5829 your patch includes sufficient directory information for the
5832 We prefer patches as plain text. MIME attachments are discouraged,
5833 and compressed attachments must not be used.
5835 * If one logical set of modifications affects or creates several
5836 files, all these changes shall be submitted in a SINGLE patch file.
5838 * Changesets that contain different, unrelated modifications shall be
5839 submitted as SEPARATE patches, one patch per changeset.
5844 * Before sending the patch, run the buildman script on your patched
5845 source tree and make sure that no errors or warnings are reported
5846 for any of the boards.
5848 * Keep your modifications to the necessary minimum: A patch
5849 containing several unrelated changes or arbitrary reformats will be
5850 returned with a request to re-formatting / split it.
5852 * If you modify existing code, make sure that your new code does not
5853 add to the memory footprint of the code ;-) Small is beautiful!
5854 When adding new features, these should compile conditionally only
5855 (using #ifdef), and the resulting code with the new feature
5856 disabled must not need more memory than the old code without your
5859 * Remember that there is a size limit of 100 kB per message on the
5860 u-boot mailing list. Bigger patches will be moderated. If they are
5861 reasonable and not too big, they will be acknowledged. But patches
5862 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob