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
331 - 8xx CPU Options: (if using an MPC8xx CPU)
332 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
333 get_gclk_freq() cannot work
334 e.g. if there is no 32KHz
335 reference PIT/RTC clock
336 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
339 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
340 CONFIG_SYS_8xx_CPUCLK_MIN
341 CONFIG_SYS_8xx_CPUCLK_MAX
342 CONFIG_8xx_CPUCLK_DEFAULT
343 See doc/README.MPC866
345 CONFIG_SYS_MEASURE_CPUCLK
347 Define this to measure the actual CPU clock instead
348 of relying on the correctness of the configured
349 values. Mostly useful for board bringup to make sure
350 the PLL is locked at the intended frequency. Note
351 that this requires a (stable) reference clock (32 kHz
352 RTC clock or CONFIG_SYS_8XX_XIN)
354 CONFIG_SYS_DELAYED_ICACHE
356 Define this option if you want to enable the
357 ICache only when Code runs from RAM.
362 Specifies that the core is a 64-bit PowerPC implementation (implements
363 the "64" category of the Power ISA). This is necessary for ePAPR
364 compliance, among other possible reasons.
366 CONFIG_SYS_FSL_TBCLK_DIV
368 Defines the core time base clock divider ratio compared to the
369 system clock. On most PQ3 devices this is 8, on newer QorIQ
370 devices it can be 16 or 32. The ratio varies from SoC to Soc.
372 CONFIG_SYS_FSL_PCIE_COMPAT
374 Defines the string to utilize when trying to match PCIe device
375 tree nodes for the given platform.
377 CONFIG_SYS_FSL_ERRATUM_A004510
379 Enables a workaround for erratum A004510. If set,
380 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
381 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
383 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
384 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
386 Defines one or two SoC revisions (low 8 bits of SVR)
387 for which the A004510 workaround should be applied.
389 The rest of SVR is either not relevant to the decision
390 of whether the erratum is present (e.g. p2040 versus
391 p2041) or is implied by the build target, which controls
392 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
394 See Freescale App Note 4493 for more information about
397 CONFIG_A003399_NOR_WORKAROUND
398 Enables a workaround for IFC erratum A003399. It is only
399 required during NOR boot.
401 CONFIG_A008044_WORKAROUND
402 Enables a workaround for T1040/T1042 erratum A008044. It is only
403 required during NAND boot and valid for Rev 1.0 SoC revision
405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
407 This is the value to write into CCSR offset 0x18600
408 according to the A004510 workaround.
410 CONFIG_SYS_FSL_DSP_DDR_ADDR
411 This value denotes start offset of DDR memory which is
412 connected exclusively to the DSP cores.
414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
415 This value denotes start offset of M2 memory
416 which is directly connected to the DSP core.
418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
419 This value denotes start offset of M3 memory which is directly
420 connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
423 This value denotes start offset of DSP CCSR space.
425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
426 Single Source Clock is clocking mode present in some of FSL SoC's.
427 In this mode, a single differential clock is used to supply
428 clocks to the sysclock, ddrclock and usbclock.
430 CONFIG_SYS_CPC_REINIT_F
431 This CONFIG is defined when the CPC is configured as SRAM at the
432 time of U-Boot entry and is required to be re-initialized.
435 Indicates this SoC supports deep sleep feature. If deep sleep is
436 supported, core will start to execute uboot when wakes up.
438 - Generic CPU options:
439 CONFIG_SYS_GENERIC_GLOBAL_DATA
440 Defines global data is initialized in generic board board_init_f().
441 If this macro is defined, global data is created and cleared in
442 generic board board_init_f(). Without this macro, architecture/board
443 should initialize global data before calling board_init_f().
445 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
447 Defines the endianess of the CPU. Implementation of those
448 values is arch specific.
451 Freescale DDR driver in use. This type of DDR controller is
452 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
455 CONFIG_SYS_FSL_DDR_ADDR
456 Freescale DDR memory-mapped register base.
458 CONFIG_SYS_FSL_DDR_EMU
459 Specify emulator support for DDR. Some DDR features such as
460 deskew training are not available.
462 CONFIG_SYS_FSL_DDRC_GEN1
463 Freescale DDR1 controller.
465 CONFIG_SYS_FSL_DDRC_GEN2
466 Freescale DDR2 controller.
468 CONFIG_SYS_FSL_DDRC_GEN3
469 Freescale DDR3 controller.
471 CONFIG_SYS_FSL_DDRC_GEN4
472 Freescale DDR4 controller.
474 CONFIG_SYS_FSL_DDRC_ARM_GEN3
475 Freescale DDR3 controller for ARM-based SoCs.
478 Board config to use DDR1. It can be enabled for SoCs with
479 Freescale DDR1 or DDR2 controllers, depending on the board
483 Board config to use DDR2. It can be enabled for SoCs with
484 Freescale DDR2 or DDR3 controllers, depending on the board
488 Board config to use DDR3. It can be enabled for SoCs with
489 Freescale DDR3 or DDR3L controllers.
492 Board config to use DDR3L. It can be enabled for SoCs with
496 Board config to use DDR4. It can be enabled for SoCs with
499 CONFIG_SYS_FSL_IFC_BE
500 Defines the IFC controller register space as Big Endian
502 CONFIG_SYS_FSL_IFC_LE
503 Defines the IFC controller register space as Little Endian
505 CONFIG_SYS_FSL_IFC_CLK_DIV
506 Defines divider of platform clock(clock input to IFC controller).
508 CONFIG_SYS_FSL_LBC_CLK_DIV
509 Defines divider of platform clock(clock input to eLBC controller).
511 CONFIG_SYS_FSL_PBL_PBI
512 It enables addition of RCW (Power on reset configuration) in built image.
513 Please refer doc/README.pblimage for more details
515 CONFIG_SYS_FSL_PBL_RCW
516 It adds PBI(pre-boot instructions) commands in u-boot build image.
517 PBI commands can be used to configure SoC before it starts the execution.
518 Please refer doc/README.pblimage for more details
521 It adds a target to create boot binary having SPL binary in PBI format
522 concatenated with u-boot binary.
524 CONFIG_SYS_FSL_DDR_BE
525 Defines the DDR controller register space as Big Endian
527 CONFIG_SYS_FSL_DDR_LE
528 Defines the DDR controller register space as Little Endian
530 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
531 Physical address from the view of DDR controllers. It is the
532 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
533 it could be different for ARM SoCs.
535 CONFIG_SYS_FSL_DDR_INTLV_256B
536 DDR controller interleaving on 256-byte. This is a special
537 interleaving mode, handled by Dickens for Freescale layerscape
540 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
541 Number of controllers used as main memory.
543 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
544 Number of controllers used for other than main memory.
546 CONFIG_SYS_FSL_HAS_DP_DDR
547 Defines the SoC has DP-DDR used for DPAA.
549 CONFIG_SYS_FSL_SEC_BE
550 Defines the SEC controller register space as Big Endian
552 CONFIG_SYS_FSL_SEC_LE
553 Defines the SEC controller register space as Little Endian
556 CONFIG_SYS_INIT_SP_OFFSET
558 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
559 pointer. This is needed for the temporary stack before
562 CONFIG_SYS_MIPS_CACHE_MODE
564 Cache operation mode for the MIPS CPU.
565 See also arch/mips/include/asm/mipsregs.h.
567 CONF_CM_CACHABLE_NO_WA
570 CONF_CM_CACHABLE_NONCOHERENT
574 CONF_CM_CACHABLE_ACCELERATED
576 CONFIG_SYS_XWAY_EBU_BOOTCFG
578 Special option for Lantiq XWAY SoCs for booting from NOR flash.
579 See also arch/mips/cpu/mips32/start.S.
581 CONFIG_XWAY_SWAP_BYTES
583 Enable compilation of tools/xway-swap-bytes needed for Lantiq
584 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
585 be swapped if a flash programmer is used.
588 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
590 Select high exception vectors of the ARM core, e.g., do not
591 clear the V bit of the c1 register of CP15.
594 Generic timer clock source frequency.
596 COUNTER_FREQUENCY_REAL
597 Generic timer clock source frequency if the real clock is
598 different from COUNTER_FREQUENCY, and can only be determined
602 CONFIG_TEGRA_SUPPORT_NON_SECURE
604 Support executing U-Boot in non-secure (NS) mode. Certain
605 impossible actions will be skipped if the CPU is in NS mode,
606 such as ARM architectural timer initialization.
608 - Linux Kernel Interface:
611 U-Boot stores all clock information in Hz
612 internally. For binary compatibility with older Linux
613 kernels (which expect the clocks passed in the
614 bd_info data to be in MHz) the environment variable
615 "clocks_in_mhz" can be defined so that U-Boot
616 converts clock data to MHZ before passing it to the
618 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
619 "clocks_in_mhz=1" is automatically included in the
622 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
624 When transferring memsize parameter to Linux, some versions
625 expect it to be in bytes, others in MB.
626 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
630 New kernel versions are expecting firmware settings to be
631 passed using flattened device trees (based on open firmware
635 * New libfdt-based support
636 * Adds the "fdt" command
637 * The bootm command automatically updates the fdt
639 OF_CPU - The proper name of the cpus node (only required for
640 MPC512X and MPC5xxx based boards).
641 OF_SOC - The proper name of the soc node (only required for
642 MPC512X and MPC5xxx based boards).
643 OF_TBCLK - The timebase frequency.
644 OF_STDOUT_PATH - The path to the console device
646 boards with QUICC Engines require OF_QE to set UCC MAC
649 CONFIG_OF_BOARD_SETUP
651 Board code has addition modification that it wants to make
652 to the flat device tree before handing it off to the kernel
654 CONFIG_OF_SYSTEM_SETUP
656 Other code has addition modification that it wants to make
657 to the flat device tree before handing it off to the kernel.
658 This causes ft_system_setup() to be called before booting
663 U-Boot can detect if an IDE device is present or not.
664 If not, and this new config option is activated, U-Boot
665 removes the ATA node from the DTS before booting Linux,
666 so the Linux IDE driver does not probe the device and
667 crash. This is needed for buggy hardware (uc101) where
668 no pull down resistor is connected to the signal IDE5V_DD7.
670 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
672 This setting is mandatory for all boards that have only one
673 machine type and must be used to specify the machine type
674 number as it appears in the ARM machine registry
675 (see http://www.arm.linux.org.uk/developer/machines/).
676 Only boards that have multiple machine types supported
677 in a single configuration file and the machine type is
678 runtime discoverable, do not have to use this setting.
680 - vxWorks boot parameters:
682 bootvx constructs a valid bootline using the following
683 environments variables: bootdev, bootfile, ipaddr, netmask,
684 serverip, gatewayip, hostname, othbootargs.
685 It loads the vxWorks image pointed bootfile.
687 Note: If a "bootargs" environment is defined, it will overwride
688 the defaults discussed just above.
690 - Cache Configuration:
691 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
692 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
693 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
695 - Cache Configuration for ARM:
696 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
698 CONFIG_SYS_PL310_BASE - Physical base address of PL310
699 controller register space
704 Define this if you want support for Amba PrimeCell PL010 UARTs.
708 Define this if you want support for Amba PrimeCell PL011 UARTs.
712 If you have Amba PrimeCell PL011 UARTs, set this variable to
713 the clock speed of the UARTs.
717 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
718 define this to a list of base addresses for each (supported)
719 port. See e.g. include/configs/versatile.h
721 CONFIG_SERIAL_HW_FLOW_CONTROL
723 Define this variable to enable hw flow control in serial driver.
724 Current user of this option is drivers/serial/nsl16550.c driver
727 Depending on board, define exactly one serial port
728 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
729 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
730 console by defining CONFIG_8xx_CONS_NONE
732 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
733 port routines must be defined elsewhere
734 (i.e. serial_init(), serial_getc(), ...)
737 CONFIG_BAUDRATE - in bps
738 Select one of the baudrates listed in
739 CONFIG_SYS_BAUDRATE_TABLE, see below.
740 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
742 - Console Rx buffer length
743 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
744 the maximum receive buffer length for the SMC.
745 This option is actual only for 82xx and 8xx possible.
746 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
747 must be defined, to setup the maximum idle timeout for
752 Only needed when CONFIG_BOOTDELAY is enabled;
753 define a command string that is automatically executed
754 when no character is read on the console interface
755 within "Boot Delay" after reset.
758 This can be used to pass arguments to the bootm
759 command. The value of CONFIG_BOOTARGS goes into the
760 environment value "bootargs".
762 CONFIG_RAMBOOT and CONFIG_NFSBOOT
763 The value of these goes into the environment as
764 "ramboot" and "nfsboot" respectively, and can be used
765 as a convenience, when switching between booting from
769 CONFIG_BOOTCOUNT_LIMIT
770 Implements a mechanism for detecting a repeating reboot
772 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
775 If no softreset save registers are found on the hardware
776 "bootcount" is stored in the environment. To prevent a
777 saveenv on all reboots, the environment variable
778 "upgrade_available" is used. If "upgrade_available" is
779 0, "bootcount" is always 0, if "upgrade_available" is
780 1 "bootcount" is incremented in the environment.
781 So the Userspace Applikation must set the "upgrade_available"
782 and "bootcount" variable to 0, if a boot was successfully.
787 When this option is #defined, the existence of the
788 environment variable "preboot" will be checked
789 immediately before starting the CONFIG_BOOTDELAY
790 countdown and/or running the auto-boot command resp.
791 entering interactive mode.
793 This feature is especially useful when "preboot" is
794 automatically generated or modified. For an example
795 see the LWMON board specific code: here "preboot" is
796 modified when the user holds down a certain
797 combination of keys on the (special) keyboard when
800 - Serial Download Echo Mode:
802 If defined to 1, all characters received during a
803 serial download (using the "loads" command) are
804 echoed back. This might be needed by some terminal
805 emulations (like "cu"), but may as well just take
806 time on others. This setting #define's the initial
807 value of the "loads_echo" environment variable.
809 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
811 Select one of the baudrates listed in
812 CONFIG_SYS_BAUDRATE_TABLE, see below.
815 Monitor commands can be included or excluded
816 from the build by using the #include files
817 <config_cmd_all.h> and #undef'ing unwanted
818 commands, or adding #define's for wanted commands.
820 The default command configuration includes all commands
821 except those marked below with a "*".
823 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
824 CONFIG_CMD_ASKENV * ask for env variable
825 CONFIG_CMD_BDI bdinfo
826 CONFIG_CMD_BOOTD bootd
827 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
828 CONFIG_CMD_CACHE * icache, dcache
829 CONFIG_CMD_CONSOLE coninfo
830 CONFIG_CMD_DHCP * DHCP support
831 CONFIG_CMD_DIAG * Diagnostics
832 CONFIG_CMD_ECHO echo arguments
833 CONFIG_CMD_EDITENV edit env variable
834 CONFIG_CMD_ELF * bootelf, bootvx
835 CONFIG_CMD_ENV_EXISTS * check existence of env variable
836 CONFIG_CMD_EXPORTENV * export the environment
837 CONFIG_CMD_EXT2 * ext2 command support
838 CONFIG_CMD_EXT4 * ext4 command support
839 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
840 that work for multiple fs types
841 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
842 CONFIG_CMD_SAVEENV saveenv
843 CONFIG_CMD_FLASH flinfo, erase, protect
844 CONFIG_CMD_FPGA FPGA device initialization support
845 CONFIG_CMD_GO * the 'go' command (exec code)
846 CONFIG_CMD_GREPENV * search environment
847 CONFIG_CMD_I2C * I2C serial bus support
848 CONFIG_CMD_IMI iminfo
849 CONFIG_CMD_IMLS List all images found in NOR flash
850 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
851 CONFIG_CMD_IMPORTENV * import an environment
852 CONFIG_CMD_INI * import data from an ini file into the env
853 CONFIG_CMD_ITEST Integer/string test of 2 values
854 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
855 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
857 CONFIG_CMD_LOADB loadb
858 CONFIG_CMD_LOADS loads
859 CONFIG_CMD_MD5SUM * print md5 message digest
860 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
861 CONFIG_CMD_MEMINFO * Display detailed memory information
862 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
864 CONFIG_CMD_MEMTEST * mtest
865 CONFIG_CMD_MISC Misc functions like sleep etc
866 CONFIG_CMD_MMC * MMC memory mapped support
867 CONFIG_CMD_MII * MII utility commands
868 CONFIG_CMD_MTDPARTS * MTD partition support
869 CONFIG_CMD_NAND * NAND support
870 CONFIG_CMD_NET bootp, tftpboot, rarpboot
871 CONFIG_CMD_NFS NFS support
872 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
873 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
874 CONFIG_CMD_PCI * pciinfo
875 CONFIG_CMD_PCMCIA * PCMCIA support
876 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
878 CONFIG_CMD_PORTIO * Port I/O
879 CONFIG_CMD_READ * Read raw data from partition
880 CONFIG_CMD_REGINFO * Register dump
881 CONFIG_CMD_RUN run command in env variable
882 CONFIG_CMD_SANDBOX * sb command to access sandbox features
883 CONFIG_CMD_SAVES * save S record dump
884 CONFIG_SCSI * SCSI Support
885 CONFIG_CMD_SDRAM * print SDRAM configuration information
886 (requires CONFIG_CMD_I2C)
887 CONFIG_CMD_SETGETDCR Support for DCR Register access
889 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
890 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
891 CONFIG_CMD_SOURCE "source" command Support
892 CONFIG_CMD_SPI * SPI serial bus support
893 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
894 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
895 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
896 CONFIG_CMD_TIMER * access to the system tick timer
897 CONFIG_CMD_USB * USB support
898 CONFIG_CMD_CDP * Cisco Discover Protocol support
899 CONFIG_CMD_MFSL * Microblaze FSL support
900 CONFIG_CMD_XIMG Load part of Multi Image
901 CONFIG_CMD_UUID * Generate random UUID or GUID string
903 EXAMPLE: If you want all functions except of network
904 support you can write:
906 #include "config_cmd_all.h"
907 #undef CONFIG_CMD_NET
910 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
912 Note: Don't enable the "icache" and "dcache" commands
913 (configuration option CONFIG_CMD_CACHE) unless you know
914 what you (and your U-Boot users) are doing. Data
915 cache cannot be enabled on systems like the 8xx or
916 8260 (where accesses to the IMMR region must be
917 uncached), and it cannot be disabled on all other
918 systems where we (mis-) use the data cache to hold an
919 initial stack and some data.
922 XXX - this list needs to get updated!
924 - Removal of commands
925 If no commands are needed to boot, you can disable
926 CONFIG_CMDLINE to remove them. In this case, the command line
927 will not be available, and when U-Boot wants to execute the
928 boot command (on start-up) it will call board_run_command()
929 instead. This can reduce image size significantly for very
930 simple boot procedures.
932 - Regular expression support:
934 If this variable is defined, U-Boot is linked against
935 the SLRE (Super Light Regular Expression) library,
936 which adds regex support to some commands, as for
937 example "env grep" and "setexpr".
941 If this variable is defined, U-Boot will use a device tree
942 to configure its devices, instead of relying on statically
943 compiled #defines in the board file. This option is
944 experimental and only available on a few boards. The device
945 tree is available in the global data as gd->fdt_blob.
947 U-Boot needs to get its device tree from somewhere. This can
948 be done using one of the three options below:
951 If this variable is defined, U-Boot will embed a device tree
952 binary in its image. This device tree file should be in the
953 board directory and called <soc>-<board>.dts. The binary file
954 is then picked up in board_init_f() and made available through
955 the global data structure as gd->blob.
958 If this variable is defined, U-Boot will build a device tree
959 binary. It will be called u-boot.dtb. Architecture-specific
960 code will locate it at run-time. Generally this works by:
962 cat u-boot.bin u-boot.dtb >image.bin
964 and in fact, U-Boot does this for you, creating a file called
965 u-boot-dtb.bin which is useful in the common case. You can
966 still use the individual files if you need something more
970 If this variable is defined, U-Boot will use the device tree
971 provided by the board at runtime instead of embedding one with
972 the image. Only boards defining board_fdt_blob_setup() support
973 this option (see include/fdtdec.h file).
977 If this variable is defined, it enables watchdog
978 support for the SoC. There must be support in the SoC
979 specific code for a watchdog. For the 8xx and 8260
980 CPUs, the SIU Watchdog feature is enabled in the SYPCR
981 register. When supported for a specific SoC is
982 available, then no further board specific code should
986 When using a watchdog circuitry external to the used
987 SoC, then define this variable and provide board
988 specific code for the "hw_watchdog_reset" function.
990 CONFIG_AT91_HW_WDT_TIMEOUT
991 specify the timeout in seconds. default 2 seconds.
994 CONFIG_VERSION_VARIABLE
995 If this variable is defined, an environment variable
996 named "ver" is created by U-Boot showing the U-Boot
997 version as printed by the "version" command.
998 Any change to this variable will be reverted at the
1003 When CONFIG_CMD_DATE is selected, the type of the RTC
1004 has to be selected, too. Define exactly one of the
1007 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1008 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1009 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1010 CONFIG_RTC_MC146818 - use MC146818 RTC
1011 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1012 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1013 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1014 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1015 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1016 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1017 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1018 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1019 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1022 Note that if the RTC uses I2C, then the I2C interface
1023 must also be configured. See I2C Support, below.
1026 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1028 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1029 chip-ngpio pairs that tell the PCA953X driver the number of
1030 pins supported by a particular chip.
1032 Note that if the GPIO device uses I2C, then the I2C interface
1033 must also be configured. See I2C Support, below.
1036 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1037 accesses and can checksum them or write a list of them out
1038 to memory. See the 'iotrace' command for details. This is
1039 useful for testing device drivers since it can confirm that
1040 the driver behaves the same way before and after a code
1041 change. Currently this is supported on sandbox and arm. To
1042 add support for your architecture, add '#include <iotrace.h>'
1043 to the bottom of arch/<arch>/include/asm/io.h and test.
1045 Example output from the 'iotrace stats' command is below.
1046 Note that if the trace buffer is exhausted, the checksum will
1047 still continue to operate.
1050 Start: 10000000 (buffer start address)
1051 Size: 00010000 (buffer size)
1052 Offset: 00000120 (current buffer offset)
1053 Output: 10000120 (start + offset)
1054 Count: 00000018 (number of trace records)
1055 CRC32: 9526fb66 (CRC32 of all trace records)
1057 - Timestamp Support:
1059 When CONFIG_TIMESTAMP is selected, the timestamp
1060 (date and time) of an image is printed by image
1061 commands like bootm or iminfo. This option is
1062 automatically enabled when you select CONFIG_CMD_DATE .
1064 - Partition Labels (disklabels) Supported:
1065 Zero or more of the following:
1066 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1067 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1068 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1069 bootloader. Note 2TB partition limit; see
1071 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1073 If IDE or SCSI support is enabled (CONFIG_IDE or
1074 CONFIG_SCSI) you must configure support for at
1075 least one non-MTD partition type as well.
1078 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1079 board configurations files but used nowhere!
1081 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1082 be performed by calling the function
1083 ide_set_reset(int reset)
1084 which has to be defined in a board specific file
1089 Set this to enable ATAPI support.
1094 Set this to enable support for disks larger than 137GB
1095 Also look at CONFIG_SYS_64BIT_LBA.
1096 Whithout these , LBA48 support uses 32bit variables and will 'only'
1097 support disks up to 2.1TB.
1099 CONFIG_SYS_64BIT_LBA:
1100 When enabled, makes the IDE subsystem use 64bit sector addresses.
1104 At the moment only there is only support for the
1105 SYM53C8XX SCSI controller; define
1106 CONFIG_SCSI_SYM53C8XX to enable it.
1108 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1109 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1110 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1111 maximum numbers of LUNs, SCSI ID's and target
1113 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1115 The environment variable 'scsidevs' is set to the number of
1116 SCSI devices found during the last scan.
1118 - NETWORK Support (PCI):
1120 Support for Intel 8254x/8257x gigabit chips.
1123 Utility code for direct access to the SPI bus on Intel 8257x.
1124 This does not do anything useful unless you set at least one
1125 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1127 CONFIG_E1000_SPI_GENERIC
1128 Allow generic access to the SPI bus on the Intel 8257x, for
1129 example with the "sspi" command.
1132 Management command for E1000 devices. When used on devices
1133 with SPI support you can reprogram the EEPROM from U-Boot.
1136 Support for Intel 82557/82559/82559ER chips.
1137 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1138 write routine for first time initialisation.
1141 Support for Digital 2114x chips.
1142 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1143 modem chip initialisation (KS8761/QS6611).
1146 Support for National dp83815 chips.
1149 Support for National dp8382[01] gigabit chips.
1151 - NETWORK Support (other):
1153 CONFIG_DRIVER_AT91EMAC
1154 Support for AT91RM9200 EMAC.
1157 Define this to use reduced MII inteface
1159 CONFIG_DRIVER_AT91EMAC_QUIET
1160 If this defined, the driver is quiet.
1161 The driver doen't show link status messages.
1163 CONFIG_CALXEDA_XGMAC
1164 Support for the Calxeda XGMAC device
1167 Support for SMSC's LAN91C96 chips.
1169 CONFIG_LAN91C96_USE_32_BIT
1170 Define this to enable 32 bit addressing
1173 Support for SMSC's LAN91C111 chip
1175 CONFIG_SMC91111_BASE
1176 Define this to hold the physical address
1177 of the device (I/O space)
1179 CONFIG_SMC_USE_32_BIT
1180 Define this if data bus is 32 bits
1182 CONFIG_SMC_USE_IOFUNCS
1183 Define this to use i/o functions instead of macros
1184 (some hardware wont work with macros)
1186 CONFIG_DRIVER_TI_EMAC
1187 Support for davinci emac
1189 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1190 Define this if you have more then 3 PHYs.
1193 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1195 CONFIG_FTGMAC100_EGIGA
1196 Define this to use GE link update with gigabit PHY.
1197 Define this if FTGMAC100 is connected to gigabit PHY.
1198 If your system has 10/100 PHY only, it might not occur
1199 wrong behavior. Because PHY usually return timeout or
1200 useless data when polling gigabit status and gigabit
1201 control registers. This behavior won't affect the
1202 correctnessof 10/100 link speed update.
1205 Support for SMSC's LAN911x and LAN921x chips
1208 Define this to hold the physical address
1209 of the device (I/O space)
1211 CONFIG_SMC911X_32_BIT
1212 Define this if data bus is 32 bits
1214 CONFIG_SMC911X_16_BIT
1215 Define this if data bus is 16 bits. If your processor
1216 automatically converts one 32 bit word to two 16 bit
1217 words you may also try CONFIG_SMC911X_32_BIT.
1220 Support for Renesas on-chip Ethernet controller
1222 CONFIG_SH_ETHER_USE_PORT
1223 Define the number of ports to be used
1225 CONFIG_SH_ETHER_PHY_ADDR
1226 Define the ETH PHY's address
1228 CONFIG_SH_ETHER_CACHE_WRITEBACK
1229 If this option is set, the driver enables cache flush.
1233 Support for PWM module on the imx6.
1237 Support TPM devices.
1239 CONFIG_TPM_TIS_INFINEON
1240 Support for Infineon i2c bus TPM devices. Only one device
1241 per system is supported at this time.
1243 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1244 Define the burst count bytes upper limit
1247 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1249 CONFIG_TPM_ST33ZP24_I2C
1250 Support for STMicroelectronics ST33ZP24 I2C devices.
1251 Requires TPM_ST33ZP24 and I2C.
1253 CONFIG_TPM_ST33ZP24_SPI
1254 Support for STMicroelectronics ST33ZP24 SPI devices.
1255 Requires TPM_ST33ZP24 and SPI.
1257 CONFIG_TPM_ATMEL_TWI
1258 Support for Atmel TWI TPM device. Requires I2C support.
1261 Support for generic parallel port TPM devices. Only one device
1262 per system is supported at this time.
1264 CONFIG_TPM_TIS_BASE_ADDRESS
1265 Base address where the generic TPM device is mapped
1266 to. Contemporary x86 systems usually map it at
1270 Add tpm monitor functions.
1271 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1272 provides monitor access to authorized functions.
1275 Define this to enable the TPM support library which provides
1276 functional interfaces to some TPM commands.
1277 Requires support for a TPM device.
1279 CONFIG_TPM_AUTH_SESSIONS
1280 Define this to enable authorized functions in the TPM library.
1281 Requires CONFIG_TPM and CONFIG_SHA1.
1284 At the moment only the UHCI host controller is
1285 supported (PIP405, MIP405, MPC5200); define
1286 CONFIG_USB_UHCI to enable it.
1287 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1288 and define CONFIG_USB_STORAGE to enable the USB
1291 Supported are USB Keyboards and USB Floppy drives
1293 MPC5200 USB requires additional defines:
1295 for 528 MHz Clock: 0x0001bbbb
1299 for differential drivers: 0x00001000
1300 for single ended drivers: 0x00005000
1301 for differential drivers on PSC3: 0x00000100
1302 for single ended drivers on PSC3: 0x00004100
1303 CONFIG_SYS_USB_EVENT_POLL
1304 May be defined to allow interrupt polling
1305 instead of using asynchronous interrupts
1307 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1308 txfilltuning field in the EHCI controller on reset.
1310 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1311 HW module registers.
1314 Define the below if you wish to use the USB console.
1315 Once firmware is rebuilt from a serial console issue the
1316 command "setenv stdin usbtty; setenv stdout usbtty" and
1317 attach your USB cable. The Unix command "dmesg" should print
1318 it has found a new device. The environment variable usbtty
1319 can be set to gserial or cdc_acm to enable your device to
1320 appear to a USB host as a Linux gserial device or a
1321 Common Device Class Abstract Control Model serial device.
1322 If you select usbtty = gserial you should be able to enumerate
1324 # modprobe usbserial vendor=0xVendorID product=0xProductID
1325 else if using cdc_acm, simply setting the environment
1326 variable usbtty to be cdc_acm should suffice. The following
1327 might be defined in YourBoardName.h
1330 Define this to build a UDC device
1333 Define this to have a tty type of device available to
1334 talk to the UDC device
1337 Define this to enable the high speed support for usb
1338 device and usbtty. If this feature is enabled, a routine
1339 int is_usbd_high_speed(void)
1340 also needs to be defined by the driver to dynamically poll
1341 whether the enumeration has succeded at high speed or full
1344 CONFIG_SYS_CONSOLE_IS_IN_ENV
1345 Define this if you want stdin, stdout &/or stderr to
1349 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1350 Derive USB clock from external clock "blah"
1351 - CONFIG_SYS_USB_EXTC_CLK 0x02
1353 If you have a USB-IF assigned VendorID then you may wish to
1354 define your own vendor specific values either in BoardName.h
1355 or directly in usbd_vendor_info.h. If you don't define
1356 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1357 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1358 should pretend to be a Linux device to it's target host.
1360 CONFIG_USBD_MANUFACTURER
1361 Define this string as the name of your company for
1362 - CONFIG_USBD_MANUFACTURER "my company"
1364 CONFIG_USBD_PRODUCT_NAME
1365 Define this string as the name of your product
1366 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1368 CONFIG_USBD_VENDORID
1369 Define this as your assigned Vendor ID from the USB
1370 Implementors Forum. This *must* be a genuine Vendor ID
1371 to avoid polluting the USB namespace.
1372 - CONFIG_USBD_VENDORID 0xFFFF
1374 CONFIG_USBD_PRODUCTID
1375 Define this as the unique Product ID
1377 - CONFIG_USBD_PRODUCTID 0xFFFF
1379 - ULPI Layer Support:
1380 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1381 the generic ULPI layer. The generic layer accesses the ULPI PHY
1382 via the platform viewport, so you need both the genric layer and
1383 the viewport enabled. Currently only Chipidea/ARC based
1384 viewport is supported.
1385 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1386 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1387 If your ULPI phy needs a different reference clock than the
1388 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1389 the appropriate value in Hz.
1392 The MMC controller on the Intel PXA is supported. To
1393 enable this define CONFIG_MMC. The MMC can be
1394 accessed from the boot prompt by mapping the device
1395 to physical memory similar to flash. Command line is
1396 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1397 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1400 Support for Renesas on-chip MMCIF controller
1402 CONFIG_SH_MMCIF_ADDR
1403 Define the base address of MMCIF registers
1406 Define the clock frequency for MMCIF
1408 CONFIG_SUPPORT_EMMC_BOOT
1409 Enable some additional features of the eMMC boot partitions.
1411 CONFIG_SUPPORT_EMMC_RPMB
1412 Enable the commands for reading, writing and programming the
1413 key for the Replay Protection Memory Block partition in eMMC.
1415 - USB Device Firmware Update (DFU) class support:
1416 CONFIG_USB_FUNCTION_DFU
1417 This enables the USB portion of the DFU USB class
1420 This enables the command "dfu" which is used to have
1421 U-Boot create a DFU class device via USB. This command
1422 requires that the "dfu_alt_info" environment variable be
1423 set and define the alt settings to expose to the host.
1426 This enables support for exposing (e)MMC devices via DFU.
1429 This enables support for exposing NAND devices via DFU.
1432 This enables support for exposing RAM via DFU.
1433 Note: DFU spec refer to non-volatile memory usage, but
1434 allow usages beyond the scope of spec - here RAM usage,
1435 one that would help mostly the developer.
1437 CONFIG_SYS_DFU_DATA_BUF_SIZE
1438 Dfu transfer uses a buffer before writing data to the
1439 raw storage device. Make the size (in bytes) of this buffer
1440 configurable. The size of this buffer is also configurable
1441 through the "dfu_bufsiz" environment variable.
1443 CONFIG_SYS_DFU_MAX_FILE_SIZE
1444 When updating files rather than the raw storage device,
1445 we use a static buffer to copy the file into and then write
1446 the buffer once we've been given the whole file. Define
1447 this to the maximum filesize (in bytes) for the buffer.
1448 Default is 4 MiB if undefined.
1450 DFU_DEFAULT_POLL_TIMEOUT
1451 Poll timeout [ms], is the timeout a device can send to the
1452 host. The host must wait for this timeout before sending
1453 a subsequent DFU_GET_STATUS request to the device.
1455 DFU_MANIFEST_POLL_TIMEOUT
1456 Poll timeout [ms], which the device sends to the host when
1457 entering dfuMANIFEST state. Host waits this timeout, before
1458 sending again an USB request to the device.
1460 - USB Device Android Fastboot support:
1461 CONFIG_USB_FUNCTION_FASTBOOT
1462 This enables the USB part of the fastboot gadget
1465 This enables the command "fastboot" which enables the Android
1466 fastboot mode for the platform's USB device. Fastboot is a USB
1467 protocol for downloading images, flashing and device control
1468 used on Android devices.
1469 See doc/README.android-fastboot for more information.
1471 CONFIG_ANDROID_BOOT_IMAGE
1472 This enables support for booting images which use the Android
1473 image format header.
1475 CONFIG_FASTBOOT_BUF_ADDR
1476 The fastboot protocol requires a large memory buffer for
1477 downloads. Define this to the starting RAM address to use for
1480 CONFIG_FASTBOOT_BUF_SIZE
1481 The fastboot protocol requires a large memory buffer for
1482 downloads. This buffer should be as large as possible for a
1483 platform. Define this to the size available RAM for fastboot.
1485 CONFIG_FASTBOOT_FLASH
1486 The fastboot protocol includes a "flash" command for writing
1487 the downloaded image to a non-volatile storage device. Define
1488 this to enable the "fastboot flash" command.
1490 CONFIG_FASTBOOT_FLASH_MMC_DEV
1491 The fastboot "flash" command requires additional information
1492 regarding the non-volatile storage device. Define this to
1493 the eMMC device that fastboot should use to store the image.
1495 CONFIG_FASTBOOT_GPT_NAME
1496 The fastboot "flash" command supports writing the downloaded
1497 image to the Protective MBR and the Primary GUID Partition
1498 Table. (Additionally, this downloaded image is post-processed
1499 to generate and write the Backup GUID Partition Table.)
1500 This occurs when the specified "partition name" on the
1501 "fastboot flash" command line matches this value.
1502 The default is "gpt" if undefined.
1504 CONFIG_FASTBOOT_MBR_NAME
1505 The fastboot "flash" command supports writing the downloaded
1507 This occurs when the "partition name" specified on the
1508 "fastboot flash" command line matches this value.
1509 If not defined the default value "mbr" is used.
1511 - Journaling Flash filesystem support:
1513 Define these for a default partition on a NAND device
1515 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1516 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1517 Define these for a default partition on a NOR device
1520 See Kconfig help for available keyboard drivers.
1524 Define this to enable a custom keyboard support.
1525 This simply calls drv_keyboard_init() which must be
1526 defined in your board-specific files. This option is deprecated
1527 and is only used by novena. For new boards, use driver model
1532 Enable the Freescale DIU video driver. Reference boards for
1533 SOCs that have a DIU should define this macro to enable DIU
1534 support, and should also define these other macros:
1539 CONFIG_VIDEO_SW_CURSOR
1540 CONFIG_VGA_AS_SINGLE_DEVICE
1542 CONFIG_VIDEO_BMP_LOGO
1544 The DIU driver will look for the 'video-mode' environment
1545 variable, and if defined, enable the DIU as a console during
1546 boot. See the documentation file doc/README.video for a
1547 description of this variable.
1549 - LCD Support: CONFIG_LCD
1551 Define this to enable LCD support (for output to LCD
1552 display); also select one of the supported displays
1553 by defining one of these:
1557 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1559 CONFIG_NEC_NL6448AC33:
1561 NEC NL6448AC33-18. Active, color, single scan.
1563 CONFIG_NEC_NL6448BC20
1565 NEC NL6448BC20-08. 6.5", 640x480.
1566 Active, color, single scan.
1568 CONFIG_NEC_NL6448BC33_54
1570 NEC NL6448BC33-54. 10.4", 640x480.
1571 Active, color, single scan.
1575 Sharp 320x240. Active, color, single scan.
1576 It isn't 16x9, and I am not sure what it is.
1578 CONFIG_SHARP_LQ64D341
1580 Sharp LQ64D341 display, 640x480.
1581 Active, color, single scan.
1585 HLD1045 display, 640x480.
1586 Active, color, single scan.
1590 Optrex CBL50840-2 NF-FW 99 22 M5
1592 Hitachi LMG6912RPFC-00T
1596 320x240. Black & white.
1598 CONFIG_LCD_ALIGNMENT
1600 Normally the LCD is page-aligned (typically 4KB). If this is
1601 defined then the LCD will be aligned to this value instead.
1602 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1603 here, since it is cheaper to change data cache settings on
1604 a per-section basis.
1609 Sometimes, for example if the display is mounted in portrait
1610 mode or even if it's mounted landscape but rotated by 180degree,
1611 we need to rotate our content of the display relative to the
1612 framebuffer, so that user can read the messages which are
1614 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1615 initialized with a given rotation from "vl_rot" out of
1616 "vidinfo_t" which is provided by the board specific code.
1617 The value for vl_rot is coded as following (matching to
1618 fbcon=rotate:<n> linux-kernel commandline):
1619 0 = no rotation respectively 0 degree
1620 1 = 90 degree rotation
1621 2 = 180 degree rotation
1622 3 = 270 degree rotation
1624 If CONFIG_LCD_ROTATION is not defined, the console will be
1625 initialized with 0degree rotation.
1629 Support drawing of RLE8-compressed bitmaps on the LCD.
1633 Enables an 'i2c edid' command which can read EDID
1634 information over I2C from an attached LCD display.
1636 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1638 If this option is set, the environment is checked for
1639 a variable "splashimage". If found, the usual display
1640 of logo, copyright and system information on the LCD
1641 is suppressed and the BMP image at the address
1642 specified in "splashimage" is loaded instead. The
1643 console is redirected to the "nulldev", too. This
1644 allows for a "silent" boot where a splash screen is
1645 loaded very quickly after power-on.
1647 CONFIG_SPLASHIMAGE_GUARD
1649 If this option is set, then U-Boot will prevent the environment
1650 variable "splashimage" from being set to a problematic address
1651 (see doc/README.displaying-bmps).
1652 This option is useful for targets where, due to alignment
1653 restrictions, an improperly aligned BMP image will cause a data
1654 abort. If you think you will not have problems with unaligned
1655 accesses (for example because your toolchain prevents them)
1656 there is no need to set this option.
1658 CONFIG_SPLASH_SCREEN_ALIGN
1660 If this option is set the splash image can be freely positioned
1661 on the screen. Environment variable "splashpos" specifies the
1662 position as "x,y". If a positive number is given it is used as
1663 number of pixel from left/top. If a negative number is given it
1664 is used as number of pixel from right/bottom. You can also
1665 specify 'm' for centering the image.
1668 setenv splashpos m,m
1669 => image at center of screen
1671 setenv splashpos 30,20
1672 => image at x = 30 and y = 20
1674 setenv splashpos -10,m
1675 => vertically centered image
1676 at x = dspWidth - bmpWidth - 9
1678 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1680 If this option is set, additionally to standard BMP
1681 images, gzipped BMP images can be displayed via the
1682 splashscreen support or the bmp command.
1684 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1686 If this option is set, 8-bit RLE compressed BMP images
1687 can be displayed via the splashscreen support or the
1690 - Compression support:
1693 Enabled by default to support gzip compressed images.
1697 If this option is set, support for bzip2 compressed
1698 images is included. If not, only uncompressed and gzip
1699 compressed images are supported.
1701 NOTE: the bzip2 algorithm requires a lot of RAM, so
1702 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1707 If this option is set, support for LZO compressed images
1713 The address of PHY on MII bus.
1715 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1717 The clock frequency of the MII bus
1721 If this option is set, support for speed/duplex
1722 detection of gigabit PHY is included.
1724 CONFIG_PHY_RESET_DELAY
1726 Some PHY like Intel LXT971A need extra delay after
1727 reset before any MII register access is possible.
1728 For such PHY, set this option to the usec delay
1729 required. (minimum 300usec for LXT971A)
1731 CONFIG_PHY_CMD_DELAY (ppc4xx)
1733 Some PHY like Intel LXT971A need extra delay after
1734 command issued before MII status register can be read
1739 Define a default value for the IP address to use for
1740 the default Ethernet interface, in case this is not
1741 determined through e.g. bootp.
1742 (Environment variable "ipaddr")
1744 - Server IP address:
1747 Defines a default value for the IP address of a TFTP
1748 server to contact when using the "tftboot" command.
1749 (Environment variable "serverip")
1751 CONFIG_KEEP_SERVERADDR
1753 Keeps the server's MAC address, in the env 'serveraddr'
1754 for passing to bootargs (like Linux's netconsole option)
1756 - Gateway IP address:
1759 Defines a default value for the IP address of the
1760 default router where packets to other networks are
1762 (Environment variable "gatewayip")
1767 Defines a default value for the subnet mask (or
1768 routing prefix) which is used to determine if an IP
1769 address belongs to the local subnet or needs to be
1770 forwarded through a router.
1771 (Environment variable "netmask")
1773 - Multicast TFTP Mode:
1776 Defines whether you want to support multicast TFTP as per
1777 rfc-2090; for example to work with atftp. Lets lots of targets
1778 tftp down the same boot image concurrently. Note: the Ethernet
1779 driver in use must provide a function: mcast() to join/leave a
1782 - BOOTP Recovery Mode:
1783 CONFIG_BOOTP_RANDOM_DELAY
1785 If you have many targets in a network that try to
1786 boot using BOOTP, you may want to avoid that all
1787 systems send out BOOTP requests at precisely the same
1788 moment (which would happen for instance at recovery
1789 from a power failure, when all systems will try to
1790 boot, thus flooding the BOOTP server. Defining
1791 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1792 inserted before sending out BOOTP requests. The
1793 following delays are inserted then:
1795 1st BOOTP request: delay 0 ... 1 sec
1796 2nd BOOTP request: delay 0 ... 2 sec
1797 3rd BOOTP request: delay 0 ... 4 sec
1799 BOOTP requests: delay 0 ... 8 sec
1801 CONFIG_BOOTP_ID_CACHE_SIZE
1803 BOOTP packets are uniquely identified using a 32-bit ID. The
1804 server will copy the ID from client requests to responses and
1805 U-Boot will use this to determine if it is the destination of
1806 an incoming response. Some servers will check that addresses
1807 aren't in use before handing them out (usually using an ARP
1808 ping) and therefore take up to a few hundred milliseconds to
1809 respond. Network congestion may also influence the time it
1810 takes for a response to make it back to the client. If that
1811 time is too long, U-Boot will retransmit requests. In order
1812 to allow earlier responses to still be accepted after these
1813 retransmissions, U-Boot's BOOTP client keeps a small cache of
1814 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1815 cache. The default is to keep IDs for up to four outstanding
1816 requests. Increasing this will allow U-Boot to accept offers
1817 from a BOOTP client in networks with unusually high latency.
1819 - DHCP Advanced Options:
1820 You can fine tune the DHCP functionality by defining
1821 CONFIG_BOOTP_* symbols:
1823 CONFIG_BOOTP_SUBNETMASK
1824 CONFIG_BOOTP_GATEWAY
1825 CONFIG_BOOTP_HOSTNAME
1826 CONFIG_BOOTP_NISDOMAIN
1827 CONFIG_BOOTP_BOOTPATH
1828 CONFIG_BOOTP_BOOTFILESIZE
1831 CONFIG_BOOTP_SEND_HOSTNAME
1832 CONFIG_BOOTP_NTPSERVER
1833 CONFIG_BOOTP_TIMEOFFSET
1834 CONFIG_BOOTP_VENDOREX
1835 CONFIG_BOOTP_MAY_FAIL
1837 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1838 environment variable, not the BOOTP server.
1840 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1841 after the configured retry count, the call will fail
1842 instead of starting over. This can be used to fail over
1843 to Link-local IP address configuration if the DHCP server
1846 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1847 serverip from a DHCP server, it is possible that more
1848 than one DNS serverip is offered to the client.
1849 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1850 serverip will be stored in the additional environment
1851 variable "dnsip2". The first DNS serverip is always
1852 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1855 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1856 to do a dynamic update of a DNS server. To do this, they
1857 need the hostname of the DHCP requester.
1858 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1859 of the "hostname" environment variable is passed as
1860 option 12 to the DHCP server.
1862 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1864 A 32bit value in microseconds for a delay between
1865 receiving a "DHCP Offer" and sending the "DHCP Request".
1866 This fixes a problem with certain DHCP servers that don't
1867 respond 100% of the time to a "DHCP request". E.g. On an
1868 AT91RM9200 processor running at 180MHz, this delay needed
1869 to be *at least* 15,000 usec before a Windows Server 2003
1870 DHCP server would reply 100% of the time. I recommend at
1871 least 50,000 usec to be safe. The alternative is to hope
1872 that one of the retries will be successful but note that
1873 the DHCP timeout and retry process takes a longer than
1876 - Link-local IP address negotiation:
1877 Negotiate with other link-local clients on the local network
1878 for an address that doesn't require explicit configuration.
1879 This is especially useful if a DHCP server cannot be guaranteed
1880 to exist in all environments that the device must operate.
1882 See doc/README.link-local for more information.
1885 CONFIG_CDP_DEVICE_ID
1887 The device id used in CDP trigger frames.
1889 CONFIG_CDP_DEVICE_ID_PREFIX
1891 A two character string which is prefixed to the MAC address
1896 A printf format string which contains the ascii name of
1897 the port. Normally is set to "eth%d" which sets
1898 eth0 for the first Ethernet, eth1 for the second etc.
1900 CONFIG_CDP_CAPABILITIES
1902 A 32bit integer which indicates the device capabilities;
1903 0x00000010 for a normal host which does not forwards.
1907 An ascii string containing the version of the software.
1911 An ascii string containing the name of the platform.
1915 A 32bit integer sent on the trigger.
1917 CONFIG_CDP_POWER_CONSUMPTION
1919 A 16bit integer containing the power consumption of the
1920 device in .1 of milliwatts.
1922 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1924 A byte containing the id of the VLAN.
1926 - Status LED: CONFIG_LED_STATUS
1928 Several configurations allow to display the current
1929 status using a LED. For instance, the LED will blink
1930 fast while running U-Boot code, stop blinking as
1931 soon as a reply to a BOOTP request was received, and
1932 start blinking slow once the Linux kernel is running
1933 (supported by a status LED driver in the Linux
1934 kernel). Defining CONFIG_LED_STATUS enables this
1939 CONFIG_LED_STATUS_GPIO
1940 The status LED can be connected to a GPIO pin.
1941 In such cases, the gpio_led driver can be used as a
1942 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1943 to include the gpio_led driver in the U-Boot binary.
1945 CONFIG_GPIO_LED_INVERTED_TABLE
1946 Some GPIO connected LEDs may have inverted polarity in which
1947 case the GPIO high value corresponds to LED off state and
1948 GPIO low value corresponds to LED on state.
1949 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1950 with a list of GPIO LEDs that have inverted polarity.
1952 - CAN Support: CONFIG_CAN_DRIVER
1954 Defining CONFIG_CAN_DRIVER enables CAN driver support
1955 on those systems that support this (optional)
1956 feature, like the TQM8xxL modules.
1958 - I2C Support: CONFIG_SYS_I2C
1960 This enable the NEW i2c subsystem, and will allow you to use
1961 i2c commands at the u-boot command line (as long as you set
1962 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1963 based realtime clock chips or other i2c devices. See
1964 common/cmd_i2c.c for a description of the command line
1967 ported i2c driver to the new framework:
1968 - drivers/i2c/soft_i2c.c:
1969 - activate first bus with CONFIG_SYS_I2C_SOFT define
1970 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1971 for defining speed and slave address
1972 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1973 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1974 for defining speed and slave address
1975 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1976 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1977 for defining speed and slave address
1978 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1979 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1980 for defining speed and slave address
1982 - drivers/i2c/fsl_i2c.c:
1983 - activate i2c driver with CONFIG_SYS_I2C_FSL
1984 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1985 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1986 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1988 - If your board supports a second fsl i2c bus, define
1989 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1990 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1991 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1994 - drivers/i2c/tegra_i2c.c:
1995 - activate this driver with CONFIG_SYS_I2C_TEGRA
1996 - This driver adds 4 i2c buses with a fix speed from
1997 100000 and the slave addr 0!
1999 - drivers/i2c/ppc4xx_i2c.c
2000 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2001 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2002 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2004 - drivers/i2c/i2c_mxc.c
2005 - activate this driver with CONFIG_SYS_I2C_MXC
2006 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2007 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2008 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2009 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2010 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2011 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2012 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2013 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2014 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2015 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2016 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2017 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2018 If those defines are not set, default value is 100000
2019 for speed, and 0 for slave.
2021 - drivers/i2c/rcar_i2c.c:
2022 - activate this driver with CONFIG_SYS_I2C_RCAR
2023 - This driver adds 4 i2c buses
2025 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2026 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2027 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2028 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2029 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2030 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2031 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2032 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2033 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2035 - drivers/i2c/sh_i2c.c:
2036 - activate this driver with CONFIG_SYS_I2C_SH
2037 - This driver adds from 2 to 5 i2c buses
2039 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2040 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2041 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2042 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2043 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2044 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2045 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2046 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2047 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2048 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2049 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2051 - drivers/i2c/omap24xx_i2c.c
2052 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2053 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2054 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2055 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2056 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2057 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2058 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2059 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2060 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2061 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2062 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2064 - drivers/i2c/zynq_i2c.c
2065 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2066 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2067 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2069 - drivers/i2c/s3c24x0_i2c.c:
2070 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2071 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2072 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2073 with a fix speed from 100000 and the slave addr 0!
2075 - drivers/i2c/ihs_i2c.c
2076 - activate this driver with CONFIG_SYS_I2C_IHS
2077 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2078 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2079 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2080 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2081 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2082 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2083 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2084 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2085 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2086 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2087 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2088 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2089 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2090 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2091 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2092 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2093 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2094 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2095 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2096 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2097 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2101 CONFIG_SYS_NUM_I2C_BUSES
2102 Hold the number of i2c buses you want to use.
2104 CONFIG_SYS_I2C_DIRECT_BUS
2105 define this, if you don't use i2c muxes on your hardware.
2106 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2109 CONFIG_SYS_I2C_MAX_HOPS
2110 define how many muxes are maximal consecutively connected
2111 on one i2c bus. If you not use i2c muxes, omit this
2114 CONFIG_SYS_I2C_BUSES
2115 hold a list of buses you want to use, only used if
2116 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2117 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2118 CONFIG_SYS_NUM_I2C_BUSES = 9:
2120 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2121 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2122 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2123 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2124 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2125 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2126 {1, {I2C_NULL_HOP}}, \
2127 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2128 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2132 bus 0 on adapter 0 without a mux
2133 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2134 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2135 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2136 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2137 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2138 bus 6 on adapter 1 without a mux
2139 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2140 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2142 If you do not have i2c muxes on your board, omit this define.
2144 - Legacy I2C Support:
2145 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2146 then the following macros need to be defined (examples are
2147 from include/configs/lwmon.h):
2151 (Optional). Any commands necessary to enable the I2C
2152 controller or configure ports.
2154 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2158 (Only for MPC8260 CPU). The I/O port to use (the code
2159 assumes both bits are on the same port). Valid values
2160 are 0..3 for ports A..D.
2164 The code necessary to make the I2C data line active
2165 (driven). If the data line is open collector, this
2168 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2172 The code necessary to make the I2C data line tri-stated
2173 (inactive). If the data line is open collector, this
2176 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2180 Code that returns true if the I2C data line is high,
2183 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2187 If <bit> is true, sets the I2C data line high. If it
2188 is false, it clears it (low).
2190 eg: #define I2C_SDA(bit) \
2191 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2192 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2196 If <bit> is true, sets the I2C clock line high. If it
2197 is false, it clears it (low).
2199 eg: #define I2C_SCL(bit) \
2200 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2201 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2205 This delay is invoked four times per clock cycle so this
2206 controls the rate of data transfer. The data rate thus
2207 is 1 / (I2C_DELAY * 4). Often defined to be something
2210 #define I2C_DELAY udelay(2)
2212 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2214 If your arch supports the generic GPIO framework (asm/gpio.h),
2215 then you may alternatively define the two GPIOs that are to be
2216 used as SCL / SDA. Any of the previous I2C_xxx macros will
2217 have GPIO-based defaults assigned to them as appropriate.
2219 You should define these to the GPIO value as given directly to
2220 the generic GPIO functions.
2222 CONFIG_SYS_I2C_INIT_BOARD
2224 When a board is reset during an i2c bus transfer
2225 chips might think that the current transfer is still
2226 in progress. On some boards it is possible to access
2227 the i2c SCLK line directly, either by using the
2228 processor pin as a GPIO or by having a second pin
2229 connected to the bus. If this option is defined a
2230 custom i2c_init_board() routine in boards/xxx/board.c
2231 is run early in the boot sequence.
2233 CONFIG_I2C_MULTI_BUS
2235 This option allows the use of multiple I2C buses, each of which
2236 must have a controller. At any point in time, only one bus is
2237 active. To switch to a different bus, use the 'i2c dev' command.
2238 Note that bus numbering is zero-based.
2240 CONFIG_SYS_I2C_NOPROBES
2242 This option specifies a list of I2C devices that will be skipped
2243 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2244 is set, specify a list of bus-device pairs. Otherwise, specify
2245 a 1D array of device addresses
2248 #undef CONFIG_I2C_MULTI_BUS
2249 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2251 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2253 #define CONFIG_I2C_MULTI_BUS
2254 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2256 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2258 CONFIG_SYS_SPD_BUS_NUM
2260 If defined, then this indicates the I2C bus number for DDR SPD.
2261 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2263 CONFIG_SYS_RTC_BUS_NUM
2265 If defined, then this indicates the I2C bus number for the RTC.
2266 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2268 CONFIG_SOFT_I2C_READ_REPEATED_START
2270 defining this will force the i2c_read() function in
2271 the soft_i2c driver to perform an I2C repeated start
2272 between writing the address pointer and reading the
2273 data. If this define is omitted the default behaviour
2274 of doing a stop-start sequence will be used. Most I2C
2275 devices can use either method, but some require one or
2278 - SPI Support: CONFIG_SPI
2280 Enables SPI driver (so far only tested with
2281 SPI EEPROM, also an instance works with Crystal A/D and
2282 D/As on the SACSng board)
2286 Enables the driver for SPI controller on SuperH. Currently
2287 only SH7757 is supported.
2291 Enables a software (bit-bang) SPI driver rather than
2292 using hardware support. This is a general purpose
2293 driver that only requires three general I/O port pins
2294 (two outputs, one input) to function. If this is
2295 defined, the board configuration must define several
2296 SPI configuration items (port pins to use, etc). For
2297 an example, see include/configs/sacsng.h.
2301 Enables a hardware SPI driver for general-purpose reads
2302 and writes. As with CONFIG_SOFT_SPI, the board configuration
2303 must define a list of chip-select function pointers.
2304 Currently supported on some MPC8xxx processors. For an
2305 example, see include/configs/mpc8349emds.h.
2309 Enables the driver for the SPI controllers on i.MX and MXC
2310 SoCs. Currently i.MX31/35/51 are supported.
2312 CONFIG_SYS_SPI_MXC_WAIT
2313 Timeout for waiting until spi transfer completed.
2314 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2316 - FPGA Support: CONFIG_FPGA
2318 Enables FPGA subsystem.
2320 CONFIG_FPGA_<vendor>
2322 Enables support for specific chip vendors.
2325 CONFIG_FPGA_<family>
2327 Enables support for FPGA family.
2328 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2332 Specify the number of FPGA devices to support.
2334 CONFIG_SYS_FPGA_PROG_FEEDBACK
2336 Enable printing of hash marks during FPGA configuration.
2338 CONFIG_SYS_FPGA_CHECK_BUSY
2340 Enable checks on FPGA configuration interface busy
2341 status by the configuration function. This option
2342 will require a board or device specific function to
2347 If defined, a function that provides delays in the FPGA
2348 configuration driver.
2350 CONFIG_SYS_FPGA_CHECK_CTRLC
2351 Allow Control-C to interrupt FPGA configuration
2353 CONFIG_SYS_FPGA_CHECK_ERROR
2355 Check for configuration errors during FPGA bitfile
2356 loading. For example, abort during Virtex II
2357 configuration if the INIT_B line goes low (which
2358 indicated a CRC error).
2360 CONFIG_SYS_FPGA_WAIT_INIT
2362 Maximum time to wait for the INIT_B line to de-assert
2363 after PROB_B has been de-asserted during a Virtex II
2364 FPGA configuration sequence. The default time is 500
2367 CONFIG_SYS_FPGA_WAIT_BUSY
2369 Maximum time to wait for BUSY to de-assert during
2370 Virtex II FPGA configuration. The default is 5 ms.
2372 CONFIG_SYS_FPGA_WAIT_CONFIG
2374 Time to wait after FPGA configuration. The default is
2377 - Configuration Management:
2380 Some SoCs need special image types (e.g. U-Boot binary
2381 with a special header) as build targets. By defining
2382 CONFIG_BUILD_TARGET in the SoC / board header, this
2383 special image will be automatically built upon calling
2388 If defined, this string will be added to the U-Boot
2389 version information (U_BOOT_VERSION)
2391 - Vendor Parameter Protection:
2393 U-Boot considers the values of the environment
2394 variables "serial#" (Board Serial Number) and
2395 "ethaddr" (Ethernet Address) to be parameters that
2396 are set once by the board vendor / manufacturer, and
2397 protects these variables from casual modification by
2398 the user. Once set, these variables are read-only,
2399 and write or delete attempts are rejected. You can
2400 change this behaviour:
2402 If CONFIG_ENV_OVERWRITE is #defined in your config
2403 file, the write protection for vendor parameters is
2404 completely disabled. Anybody can change or delete
2407 Alternatively, if you define _both_ an ethaddr in the
2408 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2409 Ethernet address is installed in the environment,
2410 which can be changed exactly ONCE by the user. [The
2411 serial# is unaffected by this, i. e. it remains
2414 The same can be accomplished in a more flexible way
2415 for any variable by configuring the type of access
2416 to allow for those variables in the ".flags" variable
2417 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2422 Define this variable to enable the reservation of
2423 "protected RAM", i. e. RAM which is not overwritten
2424 by U-Boot. Define CONFIG_PRAM to hold the number of
2425 kB you want to reserve for pRAM. You can overwrite
2426 this default value by defining an environment
2427 variable "pram" to the number of kB you want to
2428 reserve. Note that the board info structure will
2429 still show the full amount of RAM. If pRAM is
2430 reserved, a new environment variable "mem" will
2431 automatically be defined to hold the amount of
2432 remaining RAM in a form that can be passed as boot
2433 argument to Linux, for instance like that:
2435 setenv bootargs ... mem=\${mem}
2438 This way you can tell Linux not to use this memory,
2439 either, which results in a memory region that will
2440 not be affected by reboots.
2442 *WARNING* If your board configuration uses automatic
2443 detection of the RAM size, you must make sure that
2444 this memory test is non-destructive. So far, the
2445 following board configurations are known to be
2448 IVMS8, IVML24, SPD8xx, TQM8xxL,
2449 HERMES, IP860, RPXlite, LWMON,
2452 - Access to physical memory region (> 4GB)
2453 Some basic support is provided for operations on memory not
2454 normally accessible to U-Boot - e.g. some architectures
2455 support access to more than 4GB of memory on 32-bit
2456 machines using physical address extension or similar.
2457 Define CONFIG_PHYSMEM to access this basic support, which
2458 currently only supports clearing the memory.
2463 Define this variable to stop the system in case of a
2464 fatal error, so that you have to reset it manually.
2465 This is probably NOT a good idea for an embedded
2466 system where you want the system to reboot
2467 automatically as fast as possible, but it may be
2468 useful during development since you can try to debug
2469 the conditions that lead to the situation.
2471 CONFIG_NET_RETRY_COUNT
2473 This variable defines the number of retries for
2474 network operations like ARP, RARP, TFTP, or BOOTP
2475 before giving up the operation. If not defined, a
2476 default value of 5 is used.
2480 Timeout waiting for an ARP reply in milliseconds.
2484 Timeout in milliseconds used in NFS protocol.
2485 If you encounter "ERROR: Cannot umount" in nfs command,
2486 try longer timeout such as
2487 #define CONFIG_NFS_TIMEOUT 10000UL
2489 - Command Interpreter:
2490 CONFIG_AUTO_COMPLETE
2492 Enable auto completion of commands using TAB.
2494 CONFIG_SYS_PROMPT_HUSH_PS2
2496 This defines the secondary prompt string, which is
2497 printed when the command interpreter needs more input
2498 to complete a command. Usually "> ".
2502 In the current implementation, the local variables
2503 space and global environment variables space are
2504 separated. Local variables are those you define by
2505 simply typing `name=value'. To access a local
2506 variable later on, you have write `$name' or
2507 `${name}'; to execute the contents of a variable
2508 directly type `$name' at the command prompt.
2510 Global environment variables are those you use
2511 setenv/printenv to work with. To run a command stored
2512 in such a variable, you need to use the run command,
2513 and you must not use the '$' sign to access them.
2515 To store commands and special characters in a
2516 variable, please use double quotation marks
2517 surrounding the whole text of the variable, instead
2518 of the backslashes before semicolons and special
2521 - Command Line Editing and History:
2522 CONFIG_CMDLINE_EDITING
2524 Enable editing and History functions for interactive
2525 command line input operations
2527 - Command Line PS1/PS2 support:
2528 CONFIG_CMDLINE_PS_SUPPORT
2530 Enable support for changing the command prompt string
2531 at run-time. Only static string is supported so far.
2532 The string is obtained from environment variables PS1
2535 - Default Environment:
2536 CONFIG_EXTRA_ENV_SETTINGS
2538 Define this to contain any number of null terminated
2539 strings (variable = value pairs) that will be part of
2540 the default environment compiled into the boot image.
2542 For example, place something like this in your
2543 board's config file:
2545 #define CONFIG_EXTRA_ENV_SETTINGS \
2549 Warning: This method is based on knowledge about the
2550 internal format how the environment is stored by the
2551 U-Boot code. This is NOT an official, exported
2552 interface! Although it is unlikely that this format
2553 will change soon, there is no guarantee either.
2554 You better know what you are doing here.
2556 Note: overly (ab)use of the default environment is
2557 discouraged. Make sure to check other ways to preset
2558 the environment like the "source" command or the
2561 CONFIG_ENV_VARS_UBOOT_CONFIG
2563 Define this in order to add variables describing the
2564 U-Boot build configuration to the default environment.
2565 These will be named arch, cpu, board, vendor, and soc.
2567 Enabling this option will cause the following to be defined:
2575 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2577 Define this in order to add variables describing certain
2578 run-time determined information about the hardware to the
2579 environment. These will be named board_name, board_rev.
2581 CONFIG_DELAY_ENVIRONMENT
2583 Normally the environment is loaded when the board is
2584 initialised so that it is available to U-Boot. This inhibits
2585 that so that the environment is not available until
2586 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2587 this is instead controlled by the value of
2588 /config/load-environment.
2590 - DataFlash Support:
2591 CONFIG_HAS_DATAFLASH
2593 Defining this option enables DataFlash features and
2594 allows to read/write in Dataflash via the standard
2597 - Serial Flash support
2600 Defining this option enables SPI flash commands
2601 'sf probe/read/write/erase/update'.
2603 Usage requires an initial 'probe' to define the serial
2604 flash parameters, followed by read/write/erase/update
2607 The following defaults may be provided by the platform
2608 to handle the common case when only a single serial
2609 flash is present on the system.
2611 CONFIG_SF_DEFAULT_BUS Bus identifier
2612 CONFIG_SF_DEFAULT_CS Chip-select
2613 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2614 CONFIG_SF_DEFAULT_SPEED in Hz
2618 Define this option to include a destructive SPI flash
2621 CONFIG_SF_DUAL_FLASH Dual flash memories
2623 Define this option to use dual flash support where two flash
2624 memories can be connected with a given cs line.
2625 Currently Xilinx Zynq qspi supports these type of connections.
2627 - SystemACE Support:
2630 Adding this option adds support for Xilinx SystemACE
2631 chips attached via some sort of local bus. The address
2632 of the chip must also be defined in the
2633 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2635 #define CONFIG_SYSTEMACE
2636 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2638 When SystemACE support is added, the "ace" device type
2639 becomes available to the fat commands, i.e. fatls.
2641 - TFTP Fixed UDP Port:
2644 If this is defined, the environment variable tftpsrcp
2645 is used to supply the TFTP UDP source port value.
2646 If tftpsrcp isn't defined, the normal pseudo-random port
2647 number generator is used.
2649 Also, the environment variable tftpdstp is used to supply
2650 the TFTP UDP destination port value. If tftpdstp isn't
2651 defined, the normal port 69 is used.
2653 The purpose for tftpsrcp is to allow a TFTP server to
2654 blindly start the TFTP transfer using the pre-configured
2655 target IP address and UDP port. This has the effect of
2656 "punching through" the (Windows XP) firewall, allowing
2657 the remainder of the TFTP transfer to proceed normally.
2658 A better solution is to properly configure the firewall,
2659 but sometimes that is not allowed.
2661 - bootcount support:
2662 CONFIG_BOOTCOUNT_LIMIT
2664 This enables the bootcounter support, see:
2665 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2668 enable special bootcounter support on at91sam9xe based boards.
2670 enable special bootcounter support on da850 based boards.
2671 CONFIG_BOOTCOUNT_RAM
2672 enable support for the bootcounter in RAM
2673 CONFIG_BOOTCOUNT_I2C
2674 enable support for the bootcounter on an i2c (like RTC) device.
2675 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2676 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2678 CONFIG_BOOTCOUNT_ALEN = address len
2680 - Show boot progress:
2681 CONFIG_SHOW_BOOT_PROGRESS
2683 Defining this option allows to add some board-
2684 specific code (calling a user-provided function
2685 "show_boot_progress(int)") that enables you to show
2686 the system's boot progress on some display (for
2687 example, some LED's) on your board. At the moment,
2688 the following checkpoints are implemented:
2691 Legacy uImage format:
2694 1 common/cmd_bootm.c before attempting to boot an image
2695 -1 common/cmd_bootm.c Image header has bad magic number
2696 2 common/cmd_bootm.c Image header has correct magic number
2697 -2 common/cmd_bootm.c Image header has bad checksum
2698 3 common/cmd_bootm.c Image header has correct checksum
2699 -3 common/cmd_bootm.c Image data has bad checksum
2700 4 common/cmd_bootm.c Image data has correct checksum
2701 -4 common/cmd_bootm.c Image is for unsupported architecture
2702 5 common/cmd_bootm.c Architecture check OK
2703 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2704 6 common/cmd_bootm.c Image Type check OK
2705 -6 common/cmd_bootm.c gunzip uncompression error
2706 -7 common/cmd_bootm.c Unimplemented compression type
2707 7 common/cmd_bootm.c Uncompression OK
2708 8 common/cmd_bootm.c No uncompress/copy overwrite error
2709 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2711 9 common/image.c Start initial ramdisk verification
2712 -10 common/image.c Ramdisk header has bad magic number
2713 -11 common/image.c Ramdisk header has bad checksum
2714 10 common/image.c Ramdisk header is OK
2715 -12 common/image.c Ramdisk data has bad checksum
2716 11 common/image.c Ramdisk data has correct checksum
2717 12 common/image.c Ramdisk verification complete, start loading
2718 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2719 13 common/image.c Start multifile image verification
2720 14 common/image.c No initial ramdisk, no multifile, continue.
2722 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2724 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2725 -31 post/post.c POST test failed, detected by post_output_backlog()
2726 -32 post/post.c POST test failed, detected by post_run_single()
2728 34 common/cmd_doc.c before loading a Image from a DOC device
2729 -35 common/cmd_doc.c Bad usage of "doc" command
2730 35 common/cmd_doc.c correct usage of "doc" command
2731 -36 common/cmd_doc.c No boot device
2732 36 common/cmd_doc.c correct boot device
2733 -37 common/cmd_doc.c Unknown Chip ID on boot device
2734 37 common/cmd_doc.c correct chip ID found, device available
2735 -38 common/cmd_doc.c Read Error on boot device
2736 38 common/cmd_doc.c reading Image header from DOC device OK
2737 -39 common/cmd_doc.c Image header has bad magic number
2738 39 common/cmd_doc.c Image header has correct magic number
2739 -40 common/cmd_doc.c Error reading Image from DOC device
2740 40 common/cmd_doc.c Image header has correct magic number
2741 41 common/cmd_ide.c before loading a Image from a IDE device
2742 -42 common/cmd_ide.c Bad usage of "ide" command
2743 42 common/cmd_ide.c correct usage of "ide" command
2744 -43 common/cmd_ide.c No boot device
2745 43 common/cmd_ide.c boot device found
2746 -44 common/cmd_ide.c Device not available
2747 44 common/cmd_ide.c Device available
2748 -45 common/cmd_ide.c wrong partition selected
2749 45 common/cmd_ide.c partition selected
2750 -46 common/cmd_ide.c Unknown partition table
2751 46 common/cmd_ide.c valid partition table found
2752 -47 common/cmd_ide.c Invalid partition type
2753 47 common/cmd_ide.c correct partition type
2754 -48 common/cmd_ide.c Error reading Image Header on boot device
2755 48 common/cmd_ide.c reading Image Header from IDE device OK
2756 -49 common/cmd_ide.c Image header has bad magic number
2757 49 common/cmd_ide.c Image header has correct magic number
2758 -50 common/cmd_ide.c Image header has bad checksum
2759 50 common/cmd_ide.c Image header has correct checksum
2760 -51 common/cmd_ide.c Error reading Image from IDE device
2761 51 common/cmd_ide.c reading Image from IDE device OK
2762 52 common/cmd_nand.c before loading a Image from a NAND device
2763 -53 common/cmd_nand.c Bad usage of "nand" command
2764 53 common/cmd_nand.c correct usage of "nand" command
2765 -54 common/cmd_nand.c No boot device
2766 54 common/cmd_nand.c boot device found
2767 -55 common/cmd_nand.c Unknown Chip ID on boot device
2768 55 common/cmd_nand.c correct chip ID found, device available
2769 -56 common/cmd_nand.c Error reading Image Header on boot device
2770 56 common/cmd_nand.c reading Image Header from NAND device OK
2771 -57 common/cmd_nand.c Image header has bad magic number
2772 57 common/cmd_nand.c Image header has correct magic number
2773 -58 common/cmd_nand.c Error reading Image from NAND device
2774 58 common/cmd_nand.c reading Image from NAND device OK
2776 -60 common/env_common.c Environment has a bad CRC, using default
2778 64 net/eth.c starting with Ethernet configuration.
2779 -64 net/eth.c no Ethernet found.
2780 65 net/eth.c Ethernet found.
2782 -80 common/cmd_net.c usage wrong
2783 80 common/cmd_net.c before calling net_loop()
2784 -81 common/cmd_net.c some error in net_loop() occurred
2785 81 common/cmd_net.c net_loop() back without error
2786 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2787 82 common/cmd_net.c trying automatic boot
2788 83 common/cmd_net.c running "source" command
2789 -83 common/cmd_net.c some error in automatic boot or "source" command
2790 84 common/cmd_net.c end without errors
2795 100 common/cmd_bootm.c Kernel FIT Image has correct format
2796 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2797 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2798 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2799 102 common/cmd_bootm.c Kernel unit name specified
2800 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2801 103 common/cmd_bootm.c Found configuration node
2802 104 common/cmd_bootm.c Got kernel subimage node offset
2803 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2804 105 common/cmd_bootm.c Kernel subimage hash verification OK
2805 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2806 106 common/cmd_bootm.c Architecture check OK
2807 -106 common/cmd_bootm.c Kernel subimage has wrong type
2808 107 common/cmd_bootm.c Kernel subimage type OK
2809 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2810 108 common/cmd_bootm.c Got kernel subimage data/size
2811 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2812 -109 common/cmd_bootm.c Can't get kernel subimage type
2813 -110 common/cmd_bootm.c Can't get kernel subimage comp
2814 -111 common/cmd_bootm.c Can't get kernel subimage os
2815 -112 common/cmd_bootm.c Can't get kernel subimage load address
2816 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2818 120 common/image.c Start initial ramdisk verification
2819 -120 common/image.c Ramdisk FIT image has incorrect format
2820 121 common/image.c Ramdisk FIT image has correct format
2821 122 common/image.c No ramdisk subimage unit name, using configuration
2822 -122 common/image.c Can't get configuration for ramdisk subimage
2823 123 common/image.c Ramdisk unit name specified
2824 -124 common/image.c Can't get ramdisk subimage node offset
2825 125 common/image.c Got ramdisk subimage node offset
2826 -125 common/image.c Ramdisk subimage hash verification failed
2827 126 common/image.c Ramdisk subimage hash verification OK
2828 -126 common/image.c Ramdisk subimage for unsupported architecture
2829 127 common/image.c Architecture check OK
2830 -127 common/image.c Can't get ramdisk subimage data/size
2831 128 common/image.c Got ramdisk subimage data/size
2832 129 common/image.c Can't get ramdisk load address
2833 -129 common/image.c Got ramdisk load address
2835 -130 common/cmd_doc.c Incorrect FIT image format
2836 131 common/cmd_doc.c FIT image format OK
2838 -140 common/cmd_ide.c Incorrect FIT image format
2839 141 common/cmd_ide.c FIT image format OK
2841 -150 common/cmd_nand.c Incorrect FIT image format
2842 151 common/cmd_nand.c FIT image format OK
2844 - legacy image format:
2845 CONFIG_IMAGE_FORMAT_LEGACY
2846 enables the legacy image format support in U-Boot.
2849 enabled if CONFIG_FIT_SIGNATURE is not defined.
2851 CONFIG_DISABLE_IMAGE_LEGACY
2852 disable the legacy image format
2854 This define is introduced, as the legacy image format is
2855 enabled per default for backward compatibility.
2857 - Standalone program support:
2858 CONFIG_STANDALONE_LOAD_ADDR
2860 This option defines a board specific value for the
2861 address where standalone program gets loaded, thus
2862 overwriting the architecture dependent default
2865 - Frame Buffer Address:
2868 Define CONFIG_FB_ADDR if you want to use specific
2869 address for frame buffer. This is typically the case
2870 when using a graphics controller has separate video
2871 memory. U-Boot will then place the frame buffer at
2872 the given address instead of dynamically reserving it
2873 in system RAM by calling lcd_setmem(), which grabs
2874 the memory for the frame buffer depending on the
2875 configured panel size.
2877 Please see board_init_f function.
2879 - Automatic software updates via TFTP server
2881 CONFIG_UPDATE_TFTP_CNT_MAX
2882 CONFIG_UPDATE_TFTP_MSEC_MAX
2884 These options enable and control the auto-update feature;
2885 for a more detailed description refer to doc/README.update.
2887 - MTD Support (mtdparts command, UBI support)
2890 Adds the MTD device infrastructure from the Linux kernel.
2891 Needed for mtdparts command support.
2893 CONFIG_MTD_PARTITIONS
2895 Adds the MTD partitioning infrastructure from the Linux
2896 kernel. Needed for UBI support.
2901 Adds commands for interacting with MTD partitions formatted
2902 with the UBI flash translation layer
2904 Requires also defining CONFIG_RBTREE
2906 CONFIG_UBI_SILENCE_MSG
2908 Make the verbose messages from UBI stop printing. This leaves
2909 warnings and errors enabled.
2912 CONFIG_MTD_UBI_WL_THRESHOLD
2913 This parameter defines the maximum difference between the highest
2914 erase counter value and the lowest erase counter value of eraseblocks
2915 of UBI devices. When this threshold is exceeded, UBI starts performing
2916 wear leveling by means of moving data from eraseblock with low erase
2917 counter to eraseblocks with high erase counter.
2919 The default value should be OK for SLC NAND flashes, NOR flashes and
2920 other flashes which have eraseblock life-cycle 100000 or more.
2921 However, in case of MLC NAND flashes which typically have eraseblock
2922 life-cycle less than 10000, the threshold should be lessened (e.g.,
2923 to 128 or 256, although it does not have to be power of 2).
2927 CONFIG_MTD_UBI_BEB_LIMIT
2928 This option specifies the maximum bad physical eraseblocks UBI
2929 expects on the MTD device (per 1024 eraseblocks). If the
2930 underlying flash does not admit of bad eraseblocks (e.g. NOR
2931 flash), this value is ignored.
2933 NAND datasheets often specify the minimum and maximum NVM
2934 (Number of Valid Blocks) for the flashes' endurance lifetime.
2935 The maximum expected bad eraseblocks per 1024 eraseblocks
2936 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2937 which gives 20 for most NANDs (MaxNVB is basically the total
2938 count of eraseblocks on the chip).
2940 To put it differently, if this value is 20, UBI will try to
2941 reserve about 1.9% of physical eraseblocks for bad blocks
2942 handling. And that will be 1.9% of eraseblocks on the entire
2943 NAND chip, not just the MTD partition UBI attaches. This means
2944 that if you have, say, a NAND flash chip admits maximum 40 bad
2945 eraseblocks, and it is split on two MTD partitions of the same
2946 size, UBI will reserve 40 eraseblocks when attaching a
2951 CONFIG_MTD_UBI_FASTMAP
2952 Fastmap is a mechanism which allows attaching an UBI device
2953 in nearly constant time. Instead of scanning the whole MTD device it
2954 only has to locate a checkpoint (called fastmap) on the device.
2955 The on-flash fastmap contains all information needed to attach
2956 the device. Using fastmap makes only sense on large devices where
2957 attaching by scanning takes long. UBI will not automatically install
2958 a fastmap on old images, but you can set the UBI parameter
2959 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2960 that fastmap-enabled images are still usable with UBI implementations
2961 without fastmap support. On typical flash devices the whole fastmap
2962 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2964 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2965 Set this parameter to enable fastmap automatically on images
2969 CONFIG_MTD_UBI_FM_DEBUG
2970 Enable UBI fastmap debug
2976 Adds commands for interacting with UBI volumes formatted as
2977 UBIFS. UBIFS is read-only in u-boot.
2979 Requires UBI support as well as CONFIG_LZO
2981 CONFIG_UBIFS_SILENCE_MSG
2983 Make the verbose messages from UBIFS stop printing. This leaves
2984 warnings and errors enabled.
2988 Enable building of SPL globally.
2991 LDSCRIPT for linking the SPL binary.
2993 CONFIG_SPL_MAX_FOOTPRINT
2994 Maximum size in memory allocated to the SPL, BSS included.
2995 When defined, the linker checks that the actual memory
2996 used by SPL from _start to __bss_end does not exceed it.
2997 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2998 must not be both defined at the same time.
3001 Maximum size of the SPL image (text, data, rodata, and
3002 linker lists sections), BSS excluded.
3003 When defined, the linker checks that the actual size does
3006 CONFIG_SPL_TEXT_BASE
3007 TEXT_BASE for linking the SPL binary.
3009 CONFIG_SPL_RELOC_TEXT_BASE
3010 Address to relocate to. If unspecified, this is equal to
3011 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3013 CONFIG_SPL_BSS_START_ADDR
3014 Link address for the BSS within the SPL binary.
3016 CONFIG_SPL_BSS_MAX_SIZE
3017 Maximum size in memory allocated to the SPL BSS.
3018 When defined, the linker checks that the actual memory used
3019 by SPL from __bss_start to __bss_end does not exceed it.
3020 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3021 must not be both defined at the same time.
3024 Adress of the start of the stack SPL will use
3026 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3027 When defined, SPL will panic() if the image it has
3028 loaded does not have a signature.
3029 Defining this is useful when code which loads images
3030 in SPL cannot guarantee that absolutely all read errors
3032 An example is the LPC32XX MLC NAND driver, which will
3033 consider that a completely unreadable NAND block is bad,
3034 and thus should be skipped silently.
3036 CONFIG_SPL_RELOC_STACK
3037 Adress of the start of the stack SPL will use after
3038 relocation. If unspecified, this is equal to
3041 CONFIG_SYS_SPL_MALLOC_START
3042 Starting address of the malloc pool used in SPL.
3043 When this option is set the full malloc is used in SPL and
3044 it is set up by spl_init() and before that, the simple malloc()
3045 can be used if CONFIG_SYS_MALLOC_F is defined.
3047 CONFIG_SYS_SPL_MALLOC_SIZE
3048 The size of the malloc pool used in SPL.
3050 CONFIG_SPL_FRAMEWORK
3051 Enable the SPL framework under common/. This framework
3052 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3053 NAND loading of the Linux Kernel.
3056 Enable booting directly to an OS from SPL.
3057 See also: doc/README.falcon
3059 CONFIG_SPL_DISPLAY_PRINT
3060 For ARM, enable an optional function to print more information
3061 about the running system.
3063 CONFIG_SPL_INIT_MINIMAL
3064 Arch init code should be built for a very small image
3066 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3067 Partition on the MMC to load U-Boot from when the MMC is being
3070 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3071 Sector to load kernel uImage from when MMC is being
3072 used in raw mode (for Falcon mode)
3074 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3075 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3076 Sector and number of sectors to load kernel argument
3077 parameters from when MMC is being used in raw mode
3080 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3081 Partition on the MMC to load U-Boot from when the MMC is being
3084 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3085 Filename to read to load U-Boot when reading from filesystem
3087 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3088 Filename to read to load kernel uImage when reading
3089 from filesystem (for Falcon mode)
3091 CONFIG_SPL_FS_LOAD_ARGS_NAME
3092 Filename to read to load kernel argument parameters
3093 when reading from filesystem (for Falcon mode)
3095 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3096 Set this for NAND SPL on PPC mpc83xx targets, so that
3097 start.S waits for the rest of the SPL to load before
3098 continuing (the hardware starts execution after just
3099 loading the first page rather than the full 4K).
3101 CONFIG_SPL_SKIP_RELOCATE
3102 Avoid SPL relocation
3104 CONFIG_SPL_NAND_BASE
3105 Include nand_base.c in the SPL. Requires
3106 CONFIG_SPL_NAND_DRIVERS.
3108 CONFIG_SPL_NAND_DRIVERS
3109 SPL uses normal NAND drivers, not minimal drivers.
3112 Include standard software ECC in the SPL
3114 CONFIG_SPL_NAND_SIMPLE
3115 Support for NAND boot using simple NAND drivers that
3116 expose the cmd_ctrl() interface.
3119 Support for a lightweight UBI (fastmap) scanner and
3122 CONFIG_SPL_NAND_RAW_ONLY
3123 Support to boot only raw u-boot.bin images. Use this only
3124 if you need to save space.
3126 CONFIG_SPL_COMMON_INIT_DDR
3127 Set for common ddr init with serial presence detect in
3130 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3131 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3132 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3133 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3134 CONFIG_SYS_NAND_ECCBYTES
3135 Defines the size and behavior of the NAND that SPL uses
3138 CONFIG_SPL_NAND_BOOT
3139 Add support NAND boot
3141 CONFIG_SYS_NAND_U_BOOT_OFFS
3142 Location in NAND to read U-Boot from
3144 CONFIG_SYS_NAND_U_BOOT_DST
3145 Location in memory to load U-Boot to
3147 CONFIG_SYS_NAND_U_BOOT_SIZE
3148 Size of image to load
3150 CONFIG_SYS_NAND_U_BOOT_START
3151 Entry point in loaded image to jump to
3153 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3154 Define this if you need to first read the OOB and then the
3155 data. This is used, for example, on davinci platforms.
3157 CONFIG_SPL_OMAP3_ID_NAND
3158 Support for an OMAP3-specific set of functions to return the
3159 ID and MFR of the first attached NAND chip, if present.
3161 CONFIG_SPL_RAM_DEVICE
3162 Support for running image already present in ram, in SPL binary
3165 Image offset to which the SPL should be padded before appending
3166 the SPL payload. By default, this is defined as
3167 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3168 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3169 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3172 Final target image containing SPL and payload. Some SPLs
3173 use an arch-specific makefile fragment instead, for
3174 example if more than one image needs to be produced.
3176 CONFIG_FIT_SPL_PRINT
3177 Printing information about a FIT image adds quite a bit of
3178 code to SPL. So this is normally disabled in SPL. Use this
3179 option to re-enable it. This will affect the output of the
3180 bootm command when booting a FIT image.
3184 Enable building of TPL globally.
3187 Image offset to which the TPL should be padded before appending
3188 the TPL payload. By default, this is defined as
3189 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3190 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3191 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3193 - Interrupt support (PPC):
3195 There are common interrupt_init() and timer_interrupt()
3196 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3197 for CPU specific initialization. interrupt_init_cpu()
3198 should set decrementer_count to appropriate value. If
3199 CPU resets decrementer automatically after interrupt
3200 (ppc4xx) it should set decrementer_count to zero.
3201 timer_interrupt() calls timer_interrupt_cpu() for CPU
3202 specific handling. If board has watchdog / status_led
3203 / other_activity_monitor it works automatically from
3204 general timer_interrupt().
3207 Board initialization settings:
3208 ------------------------------
3210 During Initialization u-boot calls a number of board specific functions
3211 to allow the preparation of board specific prerequisites, e.g. pin setup
3212 before drivers are initialized. To enable these callbacks the
3213 following configuration macros have to be defined. Currently this is
3214 architecture specific, so please check arch/your_architecture/lib/board.c
3215 typically in board_init_f() and board_init_r().
3217 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3218 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3219 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3220 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3222 Configuration Settings:
3223 -----------------------
3225 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3226 Optionally it can be defined to support 64-bit memory commands.
3228 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3229 undefine this when you're short of memory.
3231 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3232 width of the commands listed in the 'help' command output.
3234 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3235 prompt for user input.
3237 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3239 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3241 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3243 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3244 the application (usually a Linux kernel) when it is
3247 - CONFIG_SYS_BAUDRATE_TABLE:
3248 List of legal baudrate settings for this board.
3250 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3251 Begin and End addresses of the area used by the
3254 - CONFIG_SYS_ALT_MEMTEST:
3255 Enable an alternate, more extensive memory test.
3257 - CONFIG_SYS_MEMTEST_SCRATCH:
3258 Scratch address used by the alternate memory test
3259 You only need to set this if address zero isn't writeable
3261 - CONFIG_SYS_MEM_RESERVE_SECURE
3262 Only implemented for ARMv8 for now.
3263 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3264 is substracted from total RAM and won't be reported to OS.
3265 This memory can be used as secure memory. A variable
3266 gd->arch.secure_ram is used to track the location. In systems
3267 the RAM base is not zero, or RAM is divided into banks,
3268 this variable needs to be recalcuated to get the address.
3270 - CONFIG_SYS_MEM_TOP_HIDE:
3271 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3272 this specified memory area will get subtracted from the top
3273 (end) of RAM and won't get "touched" at all by U-Boot. By
3274 fixing up gd->ram_size the Linux kernel should gets passed
3275 the now "corrected" memory size and won't touch it either.
3276 This should work for arch/ppc and arch/powerpc. Only Linux
3277 board ports in arch/powerpc with bootwrapper support that
3278 recalculate the memory size from the SDRAM controller setup
3279 will have to get fixed in Linux additionally.
3281 This option can be used as a workaround for the 440EPx/GRx
3282 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3285 WARNING: Please make sure that this value is a multiple of
3286 the Linux page size (normally 4k). If this is not the case,
3287 then the end address of the Linux memory will be located at a
3288 non page size aligned address and this could cause major
3291 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3292 Enable temporary baudrate change while serial download
3294 - CONFIG_SYS_SDRAM_BASE:
3295 Physical start address of SDRAM. _Must_ be 0 here.
3297 - CONFIG_SYS_FLASH_BASE:
3298 Physical start address of Flash memory.
3300 - CONFIG_SYS_MONITOR_BASE:
3301 Physical start address of boot monitor code (set by
3302 make config files to be same as the text base address
3303 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3304 CONFIG_SYS_FLASH_BASE when booting from flash.
3306 - CONFIG_SYS_MONITOR_LEN:
3307 Size of memory reserved for monitor code, used to
3308 determine _at_compile_time_ (!) if the environment is
3309 embedded within the U-Boot image, or in a separate
3312 - CONFIG_SYS_MALLOC_LEN:
3313 Size of DRAM reserved for malloc() use.
3315 - CONFIG_SYS_MALLOC_F_LEN
3316 Size of the malloc() pool for use before relocation. If
3317 this is defined, then a very simple malloc() implementation
3318 will become available before relocation. The address is just
3319 below the global data, and the stack is moved down to make
3322 This feature allocates regions with increasing addresses
3323 within the region. calloc() is supported, but realloc()
3324 is not available. free() is supported but does nothing.
3325 The memory will be freed (or in fact just forgotten) when
3326 U-Boot relocates itself.
3328 - CONFIG_SYS_MALLOC_SIMPLE
3329 Provides a simple and small malloc() and calloc() for those
3330 boards which do not use the full malloc in SPL (which is
3331 enabled with CONFIG_SYS_SPL_MALLOC_START).
3333 - CONFIG_SYS_NONCACHED_MEMORY:
3334 Size of non-cached memory area. This area of memory will be
3335 typically located right below the malloc() area and mapped
3336 uncached in the MMU. This is useful for drivers that would
3337 otherwise require a lot of explicit cache maintenance. For
3338 some drivers it's also impossible to properly maintain the
3339 cache. For example if the regions that need to be flushed
3340 are not a multiple of the cache-line size, *and* padding
3341 cannot be allocated between the regions to align them (i.e.
3342 if the HW requires a contiguous array of regions, and the
3343 size of each region is not cache-aligned), then a flush of
3344 one region may result in overwriting data that hardware has
3345 written to another region in the same cache-line. This can
3346 happen for example in network drivers where descriptors for
3347 buffers are typically smaller than the CPU cache-line (e.g.
3348 16 bytes vs. 32 or 64 bytes).
3350 Non-cached memory is only supported on 32-bit ARM at present.
3352 - CONFIG_SYS_BOOTM_LEN:
3353 Normally compressed uImages are limited to an
3354 uncompressed size of 8 MBytes. If this is not enough,
3355 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3356 to adjust this setting to your needs.
3358 - CONFIG_SYS_BOOTMAPSZ:
3359 Maximum size of memory mapped by the startup code of
3360 the Linux kernel; all data that must be processed by
3361 the Linux kernel (bd_info, boot arguments, FDT blob if
3362 used) must be put below this limit, unless "bootm_low"
3363 environment variable is defined and non-zero. In such case
3364 all data for the Linux kernel must be between "bootm_low"
3365 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3366 variable "bootm_mapsize" will override the value of
3367 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3368 then the value in "bootm_size" will be used instead.
3370 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3371 Enable initrd_high functionality. If defined then the
3372 initrd_high feature is enabled and the bootm ramdisk subcommand
3375 - CONFIG_SYS_BOOT_GET_CMDLINE:
3376 Enables allocating and saving kernel cmdline in space between
3377 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3379 - CONFIG_SYS_BOOT_GET_KBD:
3380 Enables allocating and saving a kernel copy of the bd_info in
3381 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3383 - CONFIG_SYS_MAX_FLASH_BANKS:
3384 Max number of Flash memory banks
3386 - CONFIG_SYS_MAX_FLASH_SECT:
3387 Max number of sectors on a Flash chip
3389 - CONFIG_SYS_FLASH_ERASE_TOUT:
3390 Timeout for Flash erase operations (in ms)
3392 - CONFIG_SYS_FLASH_WRITE_TOUT:
3393 Timeout for Flash write operations (in ms)
3395 - CONFIG_SYS_FLASH_LOCK_TOUT
3396 Timeout for Flash set sector lock bit operation (in ms)
3398 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3399 Timeout for Flash clear lock bits operation (in ms)
3401 - CONFIG_SYS_FLASH_PROTECTION
3402 If defined, hardware flash sectors protection is used
3403 instead of U-Boot software protection.
3405 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3407 Enable TFTP transfers directly to flash memory;
3408 without this option such a download has to be
3409 performed in two steps: (1) download to RAM, and (2)
3410 copy from RAM to flash.
3412 The two-step approach is usually more reliable, since
3413 you can check if the download worked before you erase
3414 the flash, but in some situations (when system RAM is
3415 too limited to allow for a temporary copy of the
3416 downloaded image) this option may be very useful.
3418 - CONFIG_SYS_FLASH_CFI:
3419 Define if the flash driver uses extra elements in the
3420 common flash structure for storing flash geometry.
3422 - CONFIG_FLASH_CFI_DRIVER
3423 This option also enables the building of the cfi_flash driver
3424 in the drivers directory
3426 - CONFIG_FLASH_CFI_MTD
3427 This option enables the building of the cfi_mtd driver
3428 in the drivers directory. The driver exports CFI flash
3431 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3432 Use buffered writes to flash.
3434 - CONFIG_FLASH_SPANSION_S29WS_N
3435 s29ws-n MirrorBit flash has non-standard addresses for buffered
3438 - CONFIG_SYS_FLASH_QUIET_TEST
3439 If this option is defined, the common CFI flash doesn't
3440 print it's warning upon not recognized FLASH banks. This
3441 is useful, if some of the configured banks are only
3442 optionally available.
3444 - CONFIG_FLASH_SHOW_PROGRESS
3445 If defined (must be an integer), print out countdown
3446 digits and dots. Recommended value: 45 (9..1) for 80
3447 column displays, 15 (3..1) for 40 column displays.
3449 - CONFIG_FLASH_VERIFY
3450 If defined, the content of the flash (destination) is compared
3451 against the source after the write operation. An error message
3452 will be printed when the contents are not identical.
3453 Please note that this option is useless in nearly all cases,
3454 since such flash programming errors usually are detected earlier
3455 while unprotecting/erasing/programming. Please only enable
3456 this option if you really know what you are doing.
3458 - CONFIG_SYS_RX_ETH_BUFFER:
3459 Defines the number of Ethernet receive buffers. On some
3460 Ethernet controllers it is recommended to set this value
3461 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3462 buffers can be full shortly after enabling the interface
3463 on high Ethernet traffic.
3464 Defaults to 4 if not defined.
3466 - CONFIG_ENV_MAX_ENTRIES
3468 Maximum number of entries in the hash table that is used
3469 internally to store the environment settings. The default
3470 setting is supposed to be generous and should work in most
3471 cases. This setting can be used to tune behaviour; see
3472 lib/hashtable.c for details.
3474 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3475 - CONFIG_ENV_FLAGS_LIST_STATIC
3476 Enable validation of the values given to environment variables when
3477 calling env set. Variables can be restricted to only decimal,
3478 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3479 the variables can also be restricted to IP address or MAC address.
3481 The format of the list is:
3482 type_attribute = [s|d|x|b|i|m]
3483 access_attribute = [a|r|o|c]
3484 attributes = type_attribute[access_attribute]
3485 entry = variable_name[:attributes]
3488 The type attributes are:
3489 s - String (default)
3492 b - Boolean ([1yYtT|0nNfF])
3496 The access attributes are:
3502 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3503 Define this to a list (string) to define the ".flags"
3504 environment variable in the default or embedded environment.
3506 - CONFIG_ENV_FLAGS_LIST_STATIC
3507 Define this to a list (string) to define validation that
3508 should be done if an entry is not found in the ".flags"
3509 environment variable. To override a setting in the static
3510 list, simply add an entry for the same variable name to the
3513 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3514 regular expression. This allows multiple variables to define the same
3515 flags without explicitly listing them for each variable.
3517 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3518 If defined, don't allow the -f switch to env set override variable
3522 If stdint.h is available with your toolchain you can define this
3523 option to enable it. You can provide option 'USE_STDINT=1' when
3524 building U-Boot to enable this.
3526 The following definitions that deal with the placement and management
3527 of environment data (variable area); in general, we support the
3528 following configurations:
3530 - CONFIG_BUILD_ENVCRC:
3532 Builds up envcrc with the target environment so that external utils
3533 may easily extract it and embed it in final U-Boot images.
3535 - CONFIG_ENV_IS_IN_FLASH:
3537 Define this if the environment is in flash memory.
3539 a) The environment occupies one whole flash sector, which is
3540 "embedded" in the text segment with the U-Boot code. This
3541 happens usually with "bottom boot sector" or "top boot
3542 sector" type flash chips, which have several smaller
3543 sectors at the start or the end. For instance, such a
3544 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3545 such a case you would place the environment in one of the
3546 4 kB sectors - with U-Boot code before and after it. With
3547 "top boot sector" type flash chips, you would put the
3548 environment in one of the last sectors, leaving a gap
3549 between U-Boot and the environment.
3551 - CONFIG_ENV_OFFSET:
3553 Offset of environment data (variable area) to the
3554 beginning of flash memory; for instance, with bottom boot
3555 type flash chips the second sector can be used: the offset
3556 for this sector is given here.
3558 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3562 This is just another way to specify the start address of
3563 the flash sector containing the environment (instead of
3566 - CONFIG_ENV_SECT_SIZE:
3568 Size of the sector containing the environment.
3571 b) Sometimes flash chips have few, equal sized, BIG sectors.
3572 In such a case you don't want to spend a whole sector for
3577 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3578 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3579 of this flash sector for the environment. This saves
3580 memory for the RAM copy of the environment.
3582 It may also save flash memory if you decide to use this
3583 when your environment is "embedded" within U-Boot code,
3584 since then the remainder of the flash sector could be used
3585 for U-Boot code. It should be pointed out that this is
3586 STRONGLY DISCOURAGED from a robustness point of view:
3587 updating the environment in flash makes it always
3588 necessary to erase the WHOLE sector. If something goes
3589 wrong before the contents has been restored from a copy in
3590 RAM, your target system will be dead.
3592 - CONFIG_ENV_ADDR_REDUND
3593 CONFIG_ENV_SIZE_REDUND
3595 These settings describe a second storage area used to hold
3596 a redundant copy of the environment data, so that there is
3597 a valid backup copy in case there is a power failure during
3598 a "saveenv" operation.
3600 BE CAREFUL! Any changes to the flash layout, and some changes to the
3601 source code will make it necessary to adapt <board>/u-boot.lds*
3605 - CONFIG_ENV_IS_IN_NVRAM:
3607 Define this if you have some non-volatile memory device
3608 (NVRAM, battery buffered SRAM) which you want to use for the
3614 These two #defines are used to determine the memory area you
3615 want to use for environment. It is assumed that this memory
3616 can just be read and written to, without any special
3619 BE CAREFUL! The first access to the environment happens quite early
3620 in U-Boot initialization (when we try to get the setting of for the
3621 console baudrate). You *MUST* have mapped your NVRAM area then, or
3624 Please note that even with NVRAM we still use a copy of the
3625 environment in RAM: we could work on NVRAM directly, but we want to
3626 keep settings there always unmodified except somebody uses "saveenv"
3627 to save the current settings.
3630 - CONFIG_ENV_IS_IN_EEPROM:
3632 Use this if you have an EEPROM or similar serial access
3633 device and a driver for it.
3635 - CONFIG_ENV_OFFSET:
3638 These two #defines specify the offset and size of the
3639 environment area within the total memory of your EEPROM.
3641 - CONFIG_SYS_I2C_EEPROM_ADDR:
3642 If defined, specified the chip address of the EEPROM device.
3643 The default address is zero.
3645 - CONFIG_SYS_I2C_EEPROM_BUS:
3646 If defined, specified the i2c bus of the EEPROM device.
3648 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3649 If defined, the number of bits used to address bytes in a
3650 single page in the EEPROM device. A 64 byte page, for example
3651 would require six bits.
3653 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3654 If defined, the number of milliseconds to delay between
3655 page writes. The default is zero milliseconds.
3657 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3658 The length in bytes of the EEPROM memory array address. Note
3659 that this is NOT the chip address length!
3661 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3662 EEPROM chips that implement "address overflow" are ones
3663 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3664 address and the extra bits end up in the "chip address" bit
3665 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3668 Note that we consider the length of the address field to
3669 still be one byte because the extra address bits are hidden
3670 in the chip address.
3672 - CONFIG_SYS_EEPROM_SIZE:
3673 The size in bytes of the EEPROM device.
3675 - CONFIG_ENV_EEPROM_IS_ON_I2C
3676 define this, if you have I2C and SPI activated, and your
3677 EEPROM, which holds the environment, is on the I2C bus.
3679 - CONFIG_I2C_ENV_EEPROM_BUS
3680 if you have an Environment on an EEPROM reached over
3681 I2C muxes, you can define here, how to reach this
3682 EEPROM. For example:
3684 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3686 EEPROM which holds the environment, is reached over
3687 a pca9547 i2c mux with address 0x70, channel 3.
3689 - CONFIG_ENV_IS_IN_DATAFLASH:
3691 Define this if you have a DataFlash memory device which you
3692 want to use for the environment.
3694 - CONFIG_ENV_OFFSET:
3698 These three #defines specify the offset and size of the
3699 environment area within the total memory of your DataFlash placed
3700 at the specified address.
3702 - CONFIG_ENV_IS_IN_SPI_FLASH:
3704 Define this if you have a SPI Flash memory device which you
3705 want to use for the environment.
3707 - CONFIG_ENV_OFFSET:
3710 These two #defines specify the offset and size of the
3711 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
3712 aligned to an erase sector boundary.
3714 - CONFIG_ENV_SECT_SIZE:
3716 Define the SPI flash's sector size.
3718 - CONFIG_ENV_OFFSET_REDUND (optional):
3720 This setting describes a second storage area of CONFIG_ENV_SIZE
3721 size used to hold a redundant copy of the environment data, so
3722 that there is a valid backup copy in case there is a power failure
3723 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3724 aligned to an erase sector boundary.
3726 - CONFIG_ENV_SPI_BUS (optional):
3727 - CONFIG_ENV_SPI_CS (optional):
3729 Define the SPI bus and chip select. If not defined they will be 0.
3731 - CONFIG_ENV_SPI_MAX_HZ (optional):
3733 Define the SPI max work clock. If not defined then use 1MHz.
3735 - CONFIG_ENV_SPI_MODE (optional):
3737 Define the SPI work mode. If not defined then use SPI_MODE_3.
3739 - CONFIG_ENV_IS_IN_REMOTE:
3741 Define this if you have a remote memory space which you
3742 want to use for the local device's environment.
3747 These two #defines specify the address and size of the
3748 environment area within the remote memory space. The
3749 local device can get the environment from remote memory
3750 space by SRIO or PCIE links.
3752 BE CAREFUL! For some special cases, the local device can not use
3753 "saveenv" command. For example, the local device will get the
3754 environment stored in a remote NOR flash by SRIO or PCIE link,
3755 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3757 - CONFIG_ENV_IS_IN_NAND:
3759 Define this if you have a NAND device which you want to use
3760 for the environment.
3762 - CONFIG_ENV_OFFSET:
3765 These two #defines specify the offset and size of the environment
3766 area within the first NAND device. CONFIG_ENV_OFFSET must be
3767 aligned to an erase block boundary.
3769 - CONFIG_ENV_OFFSET_REDUND (optional):
3771 This setting describes a second storage area of CONFIG_ENV_SIZE
3772 size used to hold a redundant copy of the environment data, so
3773 that there is a valid backup copy in case there is a power failure
3774 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3775 aligned to an erase block boundary.
3777 - CONFIG_ENV_RANGE (optional):
3779 Specifies the length of the region in which the environment
3780 can be written. This should be a multiple of the NAND device's
3781 block size. Specifying a range with more erase blocks than
3782 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3783 the range to be avoided.
3785 - CONFIG_ENV_OFFSET_OOB (optional):
3787 Enables support for dynamically retrieving the offset of the
3788 environment from block zero's out-of-band data. The
3789 "nand env.oob" command can be used to record this offset.
3790 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3791 using CONFIG_ENV_OFFSET_OOB.
3793 - CONFIG_NAND_ENV_DST
3795 Defines address in RAM to which the nand_spl code should copy the
3796 environment. If redundant environment is used, it will be copied to
3797 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3799 - CONFIG_ENV_IS_IN_UBI:
3801 Define this if you have an UBI volume that you want to use for the
3802 environment. This has the benefit of wear-leveling the environment
3803 accesses, which is important on NAND.
3805 - CONFIG_ENV_UBI_PART:
3807 Define this to a string that is the mtd partition containing the UBI.
3809 - CONFIG_ENV_UBI_VOLUME:
3811 Define this to the name of the volume that you want to store the
3814 - CONFIG_ENV_UBI_VOLUME_REDUND:
3816 Define this to the name of another volume to store a second copy of
3817 the environment in. This will enable redundant environments in UBI.
3818 It is assumed that both volumes are in the same MTD partition.
3820 - CONFIG_UBI_SILENCE_MSG
3821 - CONFIG_UBIFS_SILENCE_MSG
3823 You will probably want to define these to avoid a really noisy system
3824 when storing the env in UBI.
3826 - CONFIG_ENV_IS_IN_FAT:
3827 Define this if you want to use the FAT file system for the environment.
3829 - FAT_ENV_INTERFACE:
3831 Define this to a string that is the name of the block device.
3833 - FAT_ENV_DEVICE_AND_PART:
3835 Define this to a string to specify the partition of the device. It can
3838 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
3839 - "D:P": device D partition P. Error occurs if device D has no
3842 - "D" or "D:": device D partition 1 if device D has partition
3843 table, or the whole device D if has no partition
3845 - "D:auto": first partition in device D with bootable flag set.
3846 If none, first valid partition in device D. If no
3847 partition table then means device D.
3851 It's a string of the FAT file name. This file use to store the
3855 This must be enabled. Otherwise it cannot save the environment file.
3857 - CONFIG_ENV_IS_IN_MMC:
3859 Define this if you have an MMC device which you want to use for the
3862 - CONFIG_SYS_MMC_ENV_DEV:
3864 Specifies which MMC device the environment is stored in.
3866 - CONFIG_SYS_MMC_ENV_PART (optional):
3868 Specifies which MMC partition the environment is stored in. If not
3869 set, defaults to partition 0, the user area. Common values might be
3870 1 (first MMC boot partition), 2 (second MMC boot partition).
3872 - CONFIG_ENV_OFFSET:
3875 These two #defines specify the offset and size of the environment
3876 area within the specified MMC device.
3878 If offset is positive (the usual case), it is treated as relative to
3879 the start of the MMC partition. If offset is negative, it is treated
3880 as relative to the end of the MMC partition. This can be useful if
3881 your board may be fitted with different MMC devices, which have
3882 different sizes for the MMC partitions, and you always want the
3883 environment placed at the very end of the partition, to leave the
3884 maximum possible space before it, to store other data.
3886 These two values are in units of bytes, but must be aligned to an
3887 MMC sector boundary.
3889 - CONFIG_ENV_OFFSET_REDUND (optional):
3891 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3892 hold a redundant copy of the environment data. This provides a
3893 valid backup copy in case the other copy is corrupted, e.g. due
3894 to a power failure during a "saveenv" operation.
3896 This value may also be positive or negative; this is handled in the
3897 same way as CONFIG_ENV_OFFSET.
3899 This value is also in units of bytes, but must also be aligned to
3900 an MMC sector boundary.
3902 - CONFIG_ENV_SIZE_REDUND (optional):
3904 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3905 set. If this value is set, it must be set to the same value as
3908 - CONFIG_SYS_SPI_INIT_OFFSET
3910 Defines offset to the initial SPI buffer area in DPRAM. The
3911 area is used at an early stage (ROM part) if the environment
3912 is configured to reside in the SPI EEPROM: We need a 520 byte
3913 scratch DPRAM area. It is used between the two initialization
3914 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3915 to be a good choice since it makes it far enough from the
3916 start of the data area as well as from the stack pointer.
3918 Please note that the environment is read-only until the monitor
3919 has been relocated to RAM and a RAM copy of the environment has been
3920 created; also, when using EEPROM you will have to use getenv_f()
3921 until then to read environment variables.
3923 The environment is protected by a CRC32 checksum. Before the monitor
3924 is relocated into RAM, as a result of a bad CRC you will be working
3925 with the compiled-in default environment - *silently*!!! [This is
3926 necessary, because the first environment variable we need is the
3927 "baudrate" setting for the console - if we have a bad CRC, we don't
3928 have any device yet where we could complain.]
3930 Note: once the monitor has been relocated, then it will complain if
3931 the default environment is used; a new CRC is computed as soon as you
3932 use the "saveenv" command to store a valid environment.
3934 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3935 Echo the inverted Ethernet link state to the fault LED.
3937 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3938 also needs to be defined.
3940 - CONFIG_SYS_FAULT_MII_ADDR:
3941 MII address of the PHY to check for the Ethernet link state.
3943 - CONFIG_NS16550_MIN_FUNCTIONS:
3944 Define this if you desire to only have use of the NS16550_init
3945 and NS16550_putc functions for the serial driver located at
3946 drivers/serial/ns16550.c. This option is useful for saving
3947 space for already greatly restricted images, including but not
3948 limited to NAND_SPL configurations.
3950 - CONFIG_DISPLAY_BOARDINFO
3951 Display information about the board that U-Boot is running on
3952 when U-Boot starts up. The board function checkboard() is called
3955 - CONFIG_DISPLAY_BOARDINFO_LATE
3956 Similar to the previous option, but display this information
3957 later, once stdio is running and output goes to the LCD, if
3960 - CONFIG_BOARD_SIZE_LIMIT:
3961 Maximum size of the U-Boot image. When defined, the
3962 build system checks that the actual size does not
3965 Low Level (hardware related) configuration options:
3966 ---------------------------------------------------
3968 - CONFIG_SYS_CACHELINE_SIZE:
3969 Cache Line Size of the CPU.
3971 - CONFIG_SYS_DEFAULT_IMMR:
3972 Default address of the IMMR after system reset.
3974 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3975 and RPXsuper) to be able to adjust the position of
3976 the IMMR register after a reset.
3978 - CONFIG_SYS_CCSRBAR_DEFAULT:
3979 Default (power-on reset) physical address of CCSR on Freescale
3982 - CONFIG_SYS_CCSRBAR:
3983 Virtual address of CCSR. On a 32-bit build, this is typically
3984 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3986 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3987 for cross-platform code that uses that macro instead.
3989 - CONFIG_SYS_CCSRBAR_PHYS:
3990 Physical address of CCSR. CCSR can be relocated to a new
3991 physical address, if desired. In this case, this macro should
3992 be set to that address. Otherwise, it should be set to the
3993 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3994 is typically relocated on 36-bit builds. It is recommended
3995 that this macro be defined via the _HIGH and _LOW macros:
3997 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3998 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4000 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4001 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4002 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4003 used in assembly code, so it must not contain typecasts or
4004 integer size suffixes (e.g. "ULL").
4006 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4007 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4008 used in assembly code, so it must not contain typecasts or
4009 integer size suffixes (e.g. "ULL").
4011 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4012 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4013 forced to a value that ensures that CCSR is not relocated.
4015 - Floppy Disk Support:
4016 CONFIG_SYS_FDC_DRIVE_NUMBER
4018 the default drive number (default value 0)
4020 CONFIG_SYS_ISA_IO_STRIDE
4022 defines the spacing between FDC chipset registers
4025 CONFIG_SYS_ISA_IO_OFFSET
4027 defines the offset of register from address. It
4028 depends on which part of the data bus is connected to
4029 the FDC chipset. (default value 0)
4031 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4032 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4035 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4036 fdc_hw_init() is called at the beginning of the FDC
4037 setup. fdc_hw_init() must be provided by the board
4038 source code. It is used to make hardware-dependent
4042 Most IDE controllers were designed to be connected with PCI
4043 interface. Only few of them were designed for AHB interface.
4044 When software is doing ATA command and data transfer to
4045 IDE devices through IDE-AHB controller, some additional
4046 registers accessing to these kind of IDE-AHB controller
4049 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4050 DO NOT CHANGE unless you know exactly what you're
4051 doing! (11-4) [MPC8xx/82xx systems only]
4053 - CONFIG_SYS_INIT_RAM_ADDR:
4055 Start address of memory area that can be used for
4056 initial data and stack; please note that this must be
4057 writable memory that is working WITHOUT special
4058 initialization, i. e. you CANNOT use normal RAM which
4059 will become available only after programming the
4060 memory controller and running certain initialization
4063 U-Boot uses the following memory types:
4064 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4065 - MPC824X: data cache
4066 - PPC4xx: data cache
4068 - CONFIG_SYS_GBL_DATA_OFFSET:
4070 Offset of the initial data structure in the memory
4071 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4072 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4073 data is located at the end of the available space
4074 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4075 GENERATED_GBL_DATA_SIZE), and the initial stack is just
4076 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4077 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4080 On the MPC824X (or other systems that use the data
4081 cache for initial memory) the address chosen for
4082 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4083 point to an otherwise UNUSED address space between
4084 the top of RAM and the start of the PCI space.
4086 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4088 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4090 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4092 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4094 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4096 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4098 - CONFIG_SYS_OR_TIMING_SDRAM:
4101 - CONFIG_SYS_MAMR_PTA:
4102 periodic timer for refresh
4104 - CONFIG_SYS_DER: Debug Event Register (37-47)
4106 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4107 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4108 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4109 CONFIG_SYS_BR1_PRELIM:
4110 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4112 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4113 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4114 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4115 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4117 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4118 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4119 Machine Mode Register and Memory Periodic Timer
4120 Prescaler definitions (SDRAM timing)
4122 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4123 enable I2C microcode relocation patch (MPC8xx);
4124 define relocation offset in DPRAM [DSP2]
4126 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4127 enable SMC microcode relocation patch (MPC8xx);
4128 define relocation offset in DPRAM [SMC1]
4130 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4131 enable SPI microcode relocation patch (MPC8xx);
4132 define relocation offset in DPRAM [SCC4]
4134 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4135 Offset of the bootmode word in DPRAM used by post
4136 (Power On Self Tests). This definition overrides
4137 #define'd default value in commproc.h resp.
4140 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4141 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4142 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4143 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4144 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4145 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4146 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4147 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4148 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4150 - CONFIG_PCI_DISABLE_PCIE:
4151 Disable PCI-Express on systems where it is supported but not
4154 - CONFIG_PCI_ENUM_ONLY
4155 Only scan through and get the devices on the buses.
4156 Don't do any setup work, presumably because someone or
4157 something has already done it, and we don't need to do it
4158 a second time. Useful for platforms that are pre-booted
4159 by coreboot or similar.
4161 - CONFIG_PCI_INDIRECT_BRIDGE:
4162 Enable support for indirect PCI bridges.
4165 Chip has SRIO or not
4168 Board has SRIO 1 port available
4171 Board has SRIO 2 port available
4173 - CONFIG_SRIO_PCIE_BOOT_MASTER
4174 Board can support master function for Boot from SRIO and PCIE
4176 - CONFIG_SYS_SRIOn_MEM_VIRT:
4177 Virtual Address of SRIO port 'n' memory region
4179 - CONFIG_SYS_SRIOn_MEM_PHYS:
4180 Physical Address of SRIO port 'n' memory region
4182 - CONFIG_SYS_SRIOn_MEM_SIZE:
4183 Size of SRIO port 'n' memory region
4185 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4186 Defined to tell the NAND controller that the NAND chip is using
4188 Not all NAND drivers use this symbol.
4189 Example of drivers that use it:
4190 - drivers/mtd/nand/ndfc.c
4191 - drivers/mtd/nand/mxc_nand.c
4193 - CONFIG_SYS_NDFC_EBC0_CFG
4194 Sets the EBC0_CFG register for the NDFC. If not defined
4195 a default value will be used.
4198 Get DDR timing information from an I2C EEPROM. Common
4199 with pluggable memory modules such as SODIMMs
4202 I2C address of the SPD EEPROM
4204 - CONFIG_SYS_SPD_BUS_NUM
4205 If SPD EEPROM is on an I2C bus other than the first
4206 one, specify here. Note that the value must resolve
4207 to something your driver can deal with.
4209 - CONFIG_SYS_DDR_RAW_TIMING
4210 Get DDR timing information from other than SPD. Common with
4211 soldered DDR chips onboard without SPD. DDR raw timing
4212 parameters are extracted from datasheet and hard-coded into
4213 header files or board specific files.
4215 - CONFIG_FSL_DDR_INTERACTIVE
4216 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4218 - CONFIG_FSL_DDR_SYNC_REFRESH
4219 Enable sync of refresh for multiple controllers.
4221 - CONFIG_FSL_DDR_BIST
4222 Enable built-in memory test for Freescale DDR controllers.
4224 - CONFIG_SYS_83XX_DDR_USES_CS0
4225 Only for 83xx systems. If specified, then DDR should
4226 be configured using CS0 and CS1 instead of CS2 and CS3.
4228 - CONFIG_ETHER_ON_FEC[12]
4229 Define to enable FEC[12] on a 8xx series processor.
4231 - CONFIG_FEC[12]_PHY
4232 Define to the hardcoded PHY address which corresponds
4233 to the given FEC; i. e.
4234 #define CONFIG_FEC1_PHY 4
4235 means that the PHY with address 4 is connected to FEC1
4237 When set to -1, means to probe for first available.
4239 - CONFIG_FEC[12]_PHY_NORXERR
4240 The PHY does not have a RXERR line (RMII only).
4241 (so program the FEC to ignore it).
4244 Enable RMII mode for all FECs.
4245 Note that this is a global option, we can't
4246 have one FEC in standard MII mode and another in RMII mode.
4248 - CONFIG_CRC32_VERIFY
4249 Add a verify option to the crc32 command.
4252 => crc32 -v <address> <count> <crc32>
4254 Where address/count indicate a memory area
4255 and crc32 is the correct crc32 which the
4259 Add the "loopw" memory command. This only takes effect if
4260 the memory commands are activated globally (CONFIG_CMD_MEM).
4263 Add the "mdc" and "mwc" memory commands. These are cyclic
4268 This command will print 4 bytes (10,11,12,13) each 500 ms.
4270 => mwc.l 100 12345678 10
4271 This command will write 12345678 to address 100 all 10 ms.
4273 This only takes effect if the memory commands are activated
4274 globally (CONFIG_CMD_MEM).
4276 - CONFIG_SKIP_LOWLEVEL_INIT
4277 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4278 low level initializations (like setting up the memory
4279 controller) are omitted and/or U-Boot does not
4280 relocate itself into RAM.
4282 Normally this variable MUST NOT be defined. The only
4283 exception is when U-Boot is loaded (to RAM) by some
4284 other boot loader or by a debugger which performs
4285 these initializations itself.
4287 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4288 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4289 to be skipped. The normal CP15 init (such as enabling the
4290 instruction cache) is still performed.
4293 Modifies the behaviour of start.S when compiling a loader
4294 that is executed before the actual U-Boot. E.g. when
4295 compiling a NAND SPL.
4298 Modifies the behaviour of start.S when compiling a loader
4299 that is executed after the SPL and before the actual U-Boot.
4300 It is loaded by the SPL.
4302 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4303 Only for 85xx systems. If this variable is specified, the section
4304 .resetvec is not kept and the section .bootpg is placed in the
4305 previous 4k of the .text section.
4307 - CONFIG_ARCH_MAP_SYSMEM
4308 Generally U-Boot (and in particular the md command) uses
4309 effective address. It is therefore not necessary to regard
4310 U-Boot address as virtual addresses that need to be translated
4311 to physical addresses. However, sandbox requires this, since
4312 it maintains its own little RAM buffer which contains all
4313 addressable memory. This option causes some memory accesses
4314 to be mapped through map_sysmem() / unmap_sysmem().
4316 - CONFIG_X86_RESET_VECTOR
4317 If defined, the x86 reset vector code is included. This is not
4318 needed when U-Boot is running from Coreboot.
4320 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4321 Enables the RTC32K OSC on AM33xx based plattforms
4323 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4324 Option to disable subpage write in NAND driver
4325 driver that uses this:
4326 drivers/mtd/nand/davinci_nand.c
4328 Freescale QE/FMAN Firmware Support:
4329 -----------------------------------
4331 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4332 loading of "firmware", which is encoded in the QE firmware binary format.
4333 This firmware often needs to be loaded during U-Boot booting, so macros
4334 are used to identify the storage device (NOR flash, SPI, etc) and the address
4337 - CONFIG_SYS_FMAN_FW_ADDR
4338 The address in the storage device where the FMAN microcode is located. The
4339 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4342 - CONFIG_SYS_QE_FW_ADDR
4343 The address in the storage device where the QE microcode is located. The
4344 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4347 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4348 The maximum possible size of the firmware. The firmware binary format
4349 has a field that specifies the actual size of the firmware, but it
4350 might not be possible to read any part of the firmware unless some
4351 local storage is allocated to hold the entire firmware first.
4353 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4354 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4355 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4356 virtual address in NOR flash.
4358 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4359 Specifies that QE/FMAN firmware is located in NAND flash.
4360 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4362 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4363 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4364 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4366 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4367 Specifies that QE/FMAN firmware is located in the remote (master)
4368 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4369 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4370 window->master inbound window->master LAW->the ucode address in
4371 master's memory space.
4373 Freescale Layerscape Management Complex Firmware Support:
4374 ---------------------------------------------------------
4375 The Freescale Layerscape Management Complex (MC) supports the loading of
4377 This firmware often needs to be loaded during U-Boot booting, so macros
4378 are used to identify the storage device (NOR flash, SPI, etc) and the address
4381 - CONFIG_FSL_MC_ENET
4382 Enable the MC driver for Layerscape SoCs.
4384 Freescale Layerscape Debug Server Support:
4385 -------------------------------------------
4386 The Freescale Layerscape Debug Server Support supports the loading of
4387 "Debug Server firmware" and triggering SP boot-rom.
4388 This firmware often needs to be loaded during U-Boot booting.
4390 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4391 Define alignment of reserved memory MC requires
4396 In order to achieve reproducible builds, timestamps used in the U-Boot build
4397 process have to be set to a fixed value.
4399 This is done using the SOURCE_DATE_EPOCH environment variable.
4400 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4401 option for U-Boot or an environment variable in U-Boot.
4403 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4405 Building the Software:
4406 ======================
4408 Building U-Boot has been tested in several native build environments
4409 and in many different cross environments. Of course we cannot support
4410 all possibly existing versions of cross development tools in all
4411 (potentially obsolete) versions. In case of tool chain problems we
4412 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4413 which is extensively used to build and test U-Boot.
4415 If you are not using a native environment, it is assumed that you
4416 have GNU cross compiling tools available in your path. In this case,
4417 you must set the environment variable CROSS_COMPILE in your shell.
4418 Note that no changes to the Makefile or any other source files are
4419 necessary. For example using the ELDK on a 4xx CPU, please enter:
4421 $ CROSS_COMPILE=ppc_4xx-
4422 $ export CROSS_COMPILE
4424 Note: If you wish to generate Windows versions of the utilities in
4425 the tools directory you can use the MinGW toolchain
4426 (http://www.mingw.org). Set your HOST tools to the MinGW
4427 toolchain and execute 'make tools'. For example:
4429 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4431 Binaries such as tools/mkimage.exe will be created which can
4432 be executed on computers running Windows.
4434 U-Boot is intended to be simple to build. After installing the
4435 sources you must configure U-Boot for one specific board type. This
4440 where "NAME_defconfig" is the name of one of the existing configu-
4441 rations; see boards.cfg for supported names.
4443 Note: for some board special configuration names may exist; check if
4444 additional information is available from the board vendor; for
4445 instance, the TQM823L systems are available without (standard)
4446 or with LCD support. You can select such additional "features"
4447 when choosing the configuration, i. e.
4449 make TQM823L_defconfig
4450 - will configure for a plain TQM823L, i. e. no LCD support
4452 make TQM823L_LCD_defconfig
4453 - will configure for a TQM823L with U-Boot console on LCD
4458 Finally, type "make all", and you should get some working U-Boot
4459 images ready for download to / installation on your system:
4461 - "u-boot.bin" is a raw binary image
4462 - "u-boot" is an image in ELF binary format
4463 - "u-boot.srec" is in Motorola S-Record format
4465 By default the build is performed locally and the objects are saved
4466 in the source directory. One of the two methods can be used to change
4467 this behavior and build U-Boot to some external directory:
4469 1. Add O= to the make command line invocations:
4471 make O=/tmp/build distclean
4472 make O=/tmp/build NAME_defconfig
4473 make O=/tmp/build all
4475 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4477 export KBUILD_OUTPUT=/tmp/build
4482 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4486 Please be aware that the Makefiles assume you are using GNU make, so
4487 for instance on NetBSD you might need to use "gmake" instead of
4491 If the system board that you have is not listed, then you will need
4492 to port U-Boot to your hardware platform. To do this, follow these
4495 1. Create a new directory to hold your board specific code. Add any
4496 files you need. In your board directory, you will need at least
4497 the "Makefile" and a "<board>.c".
4498 2. Create a new configuration file "include/configs/<board>.h" for
4500 3. If you're porting U-Boot to a new CPU, then also create a new
4501 directory to hold your CPU specific code. Add any files you need.
4502 4. Run "make <board>_defconfig" with your new name.
4503 5. Type "make", and you should get a working "u-boot.srec" file
4504 to be installed on your target system.
4505 6. Debug and solve any problems that might arise.
4506 [Of course, this last step is much harder than it sounds.]
4509 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4510 ==============================================================
4512 If you have modified U-Boot sources (for instance added a new board
4513 or support for new devices, a new CPU, etc.) you are expected to
4514 provide feedback to the other developers. The feedback normally takes
4515 the form of a "patch", i. e. a context diff against a certain (latest
4516 official or latest in the git repository) version of U-Boot sources.
4518 But before you submit such a patch, please verify that your modifi-
4519 cation did not break existing code. At least make sure that *ALL* of
4520 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4521 just run the buildman script (tools/buildman/buildman), which will
4522 configure and build U-Boot for ALL supported system. Be warned, this
4523 will take a while. Please see the buildman README, or run 'buildman -H'
4527 See also "U-Boot Porting Guide" below.
4530 Monitor Commands - Overview:
4531 ============================
4533 go - start application at address 'addr'
4534 run - run commands in an environment variable
4535 bootm - boot application image from memory
4536 bootp - boot image via network using BootP/TFTP protocol
4537 bootz - boot zImage from memory
4538 tftpboot- boot image via network using TFTP protocol
4539 and env variables "ipaddr" and "serverip"
4540 (and eventually "gatewayip")
4541 tftpput - upload a file via network using TFTP protocol
4542 rarpboot- boot image via network using RARP/TFTP protocol
4543 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4544 loads - load S-Record file over serial line
4545 loadb - load binary file over serial line (kermit mode)
4547 mm - memory modify (auto-incrementing)
4548 nm - memory modify (constant address)
4549 mw - memory write (fill)
4551 cmp - memory compare
4552 crc32 - checksum calculation
4553 i2c - I2C sub-system
4554 sspi - SPI utility commands
4555 base - print or set address offset
4556 printenv- print environment variables
4557 setenv - set environment variables
4558 saveenv - save environment variables to persistent storage
4559 protect - enable or disable FLASH write protection
4560 erase - erase FLASH memory
4561 flinfo - print FLASH memory information
4562 nand - NAND memory operations (see doc/README.nand)
4563 bdinfo - print Board Info structure
4564 iminfo - print header information for application image
4565 coninfo - print console devices and informations
4566 ide - IDE sub-system
4567 loop - infinite loop on address range
4568 loopw - infinite write loop on address range
4569 mtest - simple RAM test
4570 icache - enable or disable instruction cache
4571 dcache - enable or disable data cache
4572 reset - Perform RESET of the CPU
4573 echo - echo args to console
4574 version - print monitor version
4575 help - print online help
4576 ? - alias for 'help'
4579 Monitor Commands - Detailed Description:
4580 ========================================
4584 For now: just type "help <command>".
4587 Environment Variables:
4588 ======================
4590 U-Boot supports user configuration using Environment Variables which
4591 can be made persistent by saving to Flash memory.
4593 Environment Variables are set using "setenv", printed using
4594 "printenv", and saved to Flash using "saveenv". Using "setenv"
4595 without a value can be used to delete a variable from the
4596 environment. As long as you don't save the environment you are
4597 working with an in-memory copy. In case the Flash area containing the
4598 environment is erased by accident, a default environment is provided.
4600 Some configuration options can be set using Environment Variables.
4602 List of environment variables (most likely not complete):
4604 baudrate - see CONFIG_BAUDRATE
4606 bootdelay - see CONFIG_BOOTDELAY
4608 bootcmd - see CONFIG_BOOTCOMMAND
4610 bootargs - Boot arguments when booting an RTOS image
4612 bootfile - Name of the image to load with TFTP
4614 bootm_low - Memory range available for image processing in the bootm
4615 command can be restricted. This variable is given as
4616 a hexadecimal number and defines lowest address allowed
4617 for use by the bootm command. See also "bootm_size"
4618 environment variable. Address defined by "bootm_low" is
4619 also the base of the initial memory mapping for the Linux
4620 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4623 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4624 This variable is given as a hexadecimal number and it
4625 defines the size of the memory region starting at base
4626 address bootm_low that is accessible by the Linux kernel
4627 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4628 as the default value if it is defined, and bootm_size is
4631 bootm_size - Memory range available for image processing in the bootm
4632 command can be restricted. This variable is given as
4633 a hexadecimal number and defines the size of the region
4634 allowed for use by the bootm command. See also "bootm_low"
4635 environment variable.
4637 updatefile - Location of the software update file on a TFTP server, used
4638 by the automatic software update feature. Please refer to
4639 documentation in doc/README.update for more details.
4641 autoload - if set to "no" (any string beginning with 'n'),
4642 "bootp" will just load perform a lookup of the
4643 configuration from the BOOTP server, but not try to
4644 load any image using TFTP
4646 autostart - if set to "yes", an image loaded using the "bootp",
4647 "rarpboot", "tftpboot" or "diskboot" commands will
4648 be automatically started (by internally calling
4651 If set to "no", a standalone image passed to the
4652 "bootm" command will be copied to the load address
4653 (and eventually uncompressed), but NOT be started.
4654 This can be used to load and uncompress arbitrary
4657 fdt_high - if set this restricts the maximum address that the
4658 flattened device tree will be copied into upon boot.
4659 For example, if you have a system with 1 GB memory
4660 at physical address 0x10000000, while Linux kernel
4661 only recognizes the first 704 MB as low memory, you
4662 may need to set fdt_high as 0x3C000000 to have the
4663 device tree blob be copied to the maximum address
4664 of the 704 MB low memory, so that Linux kernel can
4665 access it during the boot procedure.
4667 If this is set to the special value 0xFFFFFFFF then
4668 the fdt will not be copied at all on boot. For this
4669 to work it must reside in writable memory, have
4670 sufficient padding on the end of it for u-boot to
4671 add the information it needs into it, and the memory
4672 must be accessible by the kernel.
4674 fdtcontroladdr- if set this is the address of the control flattened
4675 device tree used by U-Boot when CONFIG_OF_CONTROL is
4678 i2cfast - (PPC405GP|PPC405EP only)
4679 if set to 'y' configures Linux I2C driver for fast
4680 mode (400kHZ). This environment variable is used in
4681 initialization code. So, for changes to be effective
4682 it must be saved and board must be reset.
4684 initrd_high - restrict positioning of initrd images:
4685 If this variable is not set, initrd images will be
4686 copied to the highest possible address in RAM; this
4687 is usually what you want since it allows for
4688 maximum initrd size. If for some reason you want to
4689 make sure that the initrd image is loaded below the
4690 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4691 variable to a value of "no" or "off" or "0".
4692 Alternatively, you can set it to a maximum upper
4693 address to use (U-Boot will still check that it
4694 does not overwrite the U-Boot stack and data).
4696 For instance, when you have a system with 16 MB
4697 RAM, and want to reserve 4 MB from use by Linux,
4698 you can do this by adding "mem=12M" to the value of
4699 the "bootargs" variable. However, now you must make
4700 sure that the initrd image is placed in the first
4701 12 MB as well - this can be done with
4703 setenv initrd_high 00c00000
4705 If you set initrd_high to 0xFFFFFFFF, this is an
4706 indication to U-Boot that all addresses are legal
4707 for the Linux kernel, including addresses in flash
4708 memory. In this case U-Boot will NOT COPY the
4709 ramdisk at all. This may be useful to reduce the
4710 boot time on your system, but requires that this
4711 feature is supported by your Linux kernel.
4713 ipaddr - IP address; needed for tftpboot command
4715 loadaddr - Default load address for commands like "bootp",
4716 "rarpboot", "tftpboot", "loadb" or "diskboot"
4718 loads_echo - see CONFIG_LOADS_ECHO
4720 serverip - TFTP server IP address; needed for tftpboot command
4722 bootretry - see CONFIG_BOOT_RETRY_TIME
4724 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4726 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4728 ethprime - controls which interface is used first.
4730 ethact - controls which interface is currently active.
4731 For example you can do the following
4733 => setenv ethact FEC
4734 => ping 192.168.0.1 # traffic sent on FEC
4735 => setenv ethact SCC
4736 => ping 10.0.0.1 # traffic sent on SCC
4738 ethrotate - When set to "no" U-Boot does not go through all
4739 available network interfaces.
4740 It just stays at the currently selected interface.
4742 netretry - When set to "no" each network operation will
4743 either succeed or fail without retrying.
4744 When set to "once" the network operation will
4745 fail when all the available network interfaces
4746 are tried once without success.
4747 Useful on scripts which control the retry operation
4750 npe_ucode - set load address for the NPE microcode
4752 silent_linux - If set then Linux will be told to boot silently, by
4753 changing the console to be empty. If "yes" it will be
4754 made silent. If "no" it will not be made silent. If
4755 unset, then it will be made silent if the U-Boot console
4758 tftpsrcp - If this is set, the value is used for TFTP's
4761 tftpdstp - If this is set, the value is used for TFTP's UDP
4762 destination port instead of the Well Know Port 69.
4764 tftpblocksize - Block size to use for TFTP transfers; if not set,
4765 we use the TFTP server's default block size
4767 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4768 seconds, minimum value is 1000 = 1 second). Defines
4769 when a packet is considered to be lost so it has to
4770 be retransmitted. The default is 5000 = 5 seconds.
4771 Lowering this value may make downloads succeed
4772 faster in networks with high packet loss rates or
4773 with unreliable TFTP servers.
4775 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4776 unit, minimum value = 0). Defines how many timeouts
4777 can happen during a single file transfer before that
4778 transfer is aborted. The default is 10, and 0 means
4779 'no timeouts allowed'. Increasing this value may help
4780 downloads succeed with high packet loss rates, or with
4781 unreliable TFTP servers or client hardware.
4783 vlan - When set to a value < 4095 the traffic over
4784 Ethernet is encapsulated/received over 802.1q
4787 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4788 Unsigned value, in milliseconds. If not set, the period will
4789 be either the default (28000), or a value based on
4790 CONFIG_NET_RETRY_COUNT, if defined. This value has
4791 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4793 The following image location variables contain the location of images
4794 used in booting. The "Image" column gives the role of the image and is
4795 not an environment variable name. The other columns are environment
4796 variable names. "File Name" gives the name of the file on a TFTP
4797 server, "RAM Address" gives the location in RAM the image will be
4798 loaded to, and "Flash Location" gives the image's address in NOR
4799 flash or offset in NAND flash.
4801 *Note* - these variables don't have to be defined for all boards, some
4802 boards currently use other variables for these purposes, and some
4803 boards use these variables for other purposes.
4805 Image File Name RAM Address Flash Location
4806 ----- --------- ----------- --------------
4807 u-boot u-boot u-boot_addr_r u-boot_addr
4808 Linux kernel bootfile kernel_addr_r kernel_addr
4809 device tree blob fdtfile fdt_addr_r fdt_addr
4810 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4812 The following environment variables may be used and automatically
4813 updated by the network boot commands ("bootp" and "rarpboot"),
4814 depending the information provided by your boot server:
4816 bootfile - see above
4817 dnsip - IP address of your Domain Name Server
4818 dnsip2 - IP address of your secondary Domain Name Server
4819 gatewayip - IP address of the Gateway (Router) to use
4820 hostname - Target hostname
4822 netmask - Subnet Mask
4823 rootpath - Pathname of the root filesystem on the NFS server
4824 serverip - see above
4827 There are two special Environment Variables:
4829 serial# - contains hardware identification information such
4830 as type string and/or serial number
4831 ethaddr - Ethernet address
4833 These variables can be set only once (usually during manufacturing of
4834 the board). U-Boot refuses to delete or overwrite these variables
4835 once they have been set once.
4838 Further special Environment Variables:
4840 ver - Contains the U-Boot version string as printed
4841 with the "version" command. This variable is
4842 readonly (see CONFIG_VERSION_VARIABLE).
4845 Please note that changes to some configuration parameters may take
4846 only effect after the next boot (yes, that's just like Windoze :-).
4849 Callback functions for environment variables:
4850 ---------------------------------------------
4852 For some environment variables, the behavior of u-boot needs to change
4853 when their values are changed. This functionality allows functions to
4854 be associated with arbitrary variables. On creation, overwrite, or
4855 deletion, the callback will provide the opportunity for some side
4856 effect to happen or for the change to be rejected.
4858 The callbacks are named and associated with a function using the
4859 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4861 These callbacks are associated with variables in one of two ways. The
4862 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4863 in the board configuration to a string that defines a list of
4864 associations. The list must be in the following format:
4866 entry = variable_name[:callback_name]
4869 If the callback name is not specified, then the callback is deleted.
4870 Spaces are also allowed anywhere in the list.
4872 Callbacks can also be associated by defining the ".callbacks" variable
4873 with the same list format above. Any association in ".callbacks" will
4874 override any association in the static list. You can define
4875 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4876 ".callbacks" environment variable in the default or embedded environment.
4878 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4879 regular expression. This allows multiple variables to be connected to
4880 the same callback without explicitly listing them all out.
4883 Command Line Parsing:
4884 =====================
4886 There are two different command line parsers available with U-Boot:
4887 the old "simple" one, and the much more powerful "hush" shell:
4889 Old, simple command line parser:
4890 --------------------------------
4892 - supports environment variables (through setenv / saveenv commands)
4893 - several commands on one line, separated by ';'
4894 - variable substitution using "... ${name} ..." syntax
4895 - special characters ('$', ';') can be escaped by prefixing with '\',
4897 setenv bootcmd bootm \${address}
4898 - You can also escape text by enclosing in single apostrophes, for example:
4899 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4904 - similar to Bourne shell, with control structures like
4905 if...then...else...fi, for...do...done; while...do...done,
4906 until...do...done, ...
4907 - supports environment ("global") variables (through setenv / saveenv
4908 commands) and local shell variables (through standard shell syntax
4909 "name=value"); only environment variables can be used with "run"
4915 (1) If a command line (or an environment variable executed by a "run"
4916 command) contains several commands separated by semicolon, and
4917 one of these commands fails, then the remaining commands will be
4920 (2) If you execute several variables with one call to run (i. e.
4921 calling run with a list of variables as arguments), any failing
4922 command will cause "run" to terminate, i. e. the remaining
4923 variables are not executed.
4925 Note for Redundant Ethernet Interfaces:
4926 =======================================
4928 Some boards come with redundant Ethernet interfaces; U-Boot supports
4929 such configurations and is capable of automatic selection of a
4930 "working" interface when needed. MAC assignment works as follows:
4932 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4933 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4934 "eth1addr" (=>eth1), "eth2addr", ...
4936 If the network interface stores some valid MAC address (for instance
4937 in SROM), this is used as default address if there is NO correspon-
4938 ding setting in the environment; if the corresponding environment
4939 variable is set, this overrides the settings in the card; that means:
4941 o If the SROM has a valid MAC address, and there is no address in the
4942 environment, the SROM's address is used.
4944 o If there is no valid address in the SROM, and a definition in the
4945 environment exists, then the value from the environment variable is
4948 o If both the SROM and the environment contain a MAC address, and
4949 both addresses are the same, this MAC address is used.
4951 o If both the SROM and the environment contain a MAC address, and the
4952 addresses differ, the value from the environment is used and a
4955 o If neither SROM nor the environment contain a MAC address, an error
4956 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4957 a random, locally-assigned MAC is used.
4959 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4960 will be programmed into hardware as part of the initialization process. This
4961 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4962 The naming convention is as follows:
4963 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4968 U-Boot is capable of booting (and performing other auxiliary operations on)
4969 images in two formats:
4971 New uImage format (FIT)
4972 -----------------------
4974 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4975 to Flattened Device Tree). It allows the use of images with multiple
4976 components (several kernels, ramdisks, etc.), with contents protected by
4977 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4983 Old image format is based on binary files which can be basically anything,
4984 preceded by a special header; see the definitions in include/image.h for
4985 details; basically, the header defines the following image properties:
4987 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4988 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4989 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4990 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4992 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4993 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4994 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4995 * Compression Type (uncompressed, gzip, bzip2)
5001 The header is marked by a special Magic Number, and both the header
5002 and the data portions of the image are secured against corruption by
5009 Although U-Boot should support any OS or standalone application
5010 easily, the main focus has always been on Linux during the design of
5013 U-Boot includes many features that so far have been part of some
5014 special "boot loader" code within the Linux kernel. Also, any
5015 "initrd" images to be used are no longer part of one big Linux image;
5016 instead, kernel and "initrd" are separate images. This implementation
5017 serves several purposes:
5019 - the same features can be used for other OS or standalone
5020 applications (for instance: using compressed images to reduce the
5021 Flash memory footprint)
5023 - it becomes much easier to port new Linux kernel versions because
5024 lots of low-level, hardware dependent stuff are done by U-Boot
5026 - the same Linux kernel image can now be used with different "initrd"
5027 images; of course this also means that different kernel images can
5028 be run with the same "initrd". This makes testing easier (you don't
5029 have to build a new "zImage.initrd" Linux image when you just
5030 change a file in your "initrd"). Also, a field-upgrade of the
5031 software is easier now.
5037 Porting Linux to U-Boot based systems:
5038 ---------------------------------------
5040 U-Boot cannot save you from doing all the necessary modifications to
5041 configure the Linux device drivers for use with your target hardware
5042 (no, we don't intend to provide a full virtual machine interface to
5045 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5047 Just make sure your machine specific header file (for instance
5048 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5049 Information structure as we define in include/asm-<arch>/u-boot.h,
5050 and make sure that your definition of IMAP_ADDR uses the same value
5051 as your U-Boot configuration in CONFIG_SYS_IMMR.
5053 Note that U-Boot now has a driver model, a unified model for drivers.
5054 If you are adding a new driver, plumb it into driver model. If there
5055 is no uclass available, you are encouraged to create one. See
5059 Configuring the Linux kernel:
5060 -----------------------------
5062 No specific requirements for U-Boot. Make sure you have some root
5063 device (initial ramdisk, NFS) for your target system.
5066 Building a Linux Image:
5067 -----------------------
5069 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5070 not used. If you use recent kernel source, a new build target
5071 "uImage" will exist which automatically builds an image usable by
5072 U-Boot. Most older kernels also have support for a "pImage" target,
5073 which was introduced for our predecessor project PPCBoot and uses a
5074 100% compatible format.
5078 make TQM850L_defconfig
5083 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5084 encapsulate a compressed Linux kernel image with header information,
5085 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5087 * build a standard "vmlinux" kernel image (in ELF binary format):
5089 * convert the kernel into a raw binary image:
5091 ${CROSS_COMPILE}-objcopy -O binary \
5092 -R .note -R .comment \
5093 -S vmlinux linux.bin
5095 * compress the binary image:
5099 * package compressed binary image for U-Boot:
5101 mkimage -A ppc -O linux -T kernel -C gzip \
5102 -a 0 -e 0 -n "Linux Kernel Image" \
5103 -d linux.bin.gz uImage
5106 The "mkimage" tool can also be used to create ramdisk images for use
5107 with U-Boot, either separated from the Linux kernel image, or
5108 combined into one file. "mkimage" encapsulates the images with a 64
5109 byte header containing information about target architecture,
5110 operating system, image type, compression method, entry points, time
5111 stamp, CRC32 checksums, etc.
5113 "mkimage" can be called in two ways: to verify existing images and
5114 print the header information, or to build new images.
5116 In the first form (with "-l" option) mkimage lists the information
5117 contained in the header of an existing U-Boot image; this includes
5118 checksum verification:
5120 tools/mkimage -l image
5121 -l ==> list image header information
5123 The second form (with "-d" option) is used to build a U-Boot image
5124 from a "data file" which is used as image payload:
5126 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5127 -n name -d data_file image
5128 -A ==> set architecture to 'arch'
5129 -O ==> set operating system to 'os'
5130 -T ==> set image type to 'type'
5131 -C ==> set compression type 'comp'
5132 -a ==> set load address to 'addr' (hex)
5133 -e ==> set entry point to 'ep' (hex)
5134 -n ==> set image name to 'name'
5135 -d ==> use image data from 'datafile'
5137 Right now, all Linux kernels for PowerPC systems use the same load
5138 address (0x00000000), but the entry point address depends on the
5141 - 2.2.x kernels have the entry point at 0x0000000C,
5142 - 2.3.x and later kernels have the entry point at 0x00000000.
5144 So a typical call to build a U-Boot image would read:
5146 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5147 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5148 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5149 > examples/uImage.TQM850L
5150 Image Name: 2.4.4 kernel for TQM850L
5151 Created: Wed Jul 19 02:34:59 2000
5152 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5153 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5154 Load Address: 0x00000000
5155 Entry Point: 0x00000000
5157 To verify the contents of the image (or check for corruption):
5159 -> tools/mkimage -l examples/uImage.TQM850L
5160 Image Name: 2.4.4 kernel for TQM850L
5161 Created: Wed Jul 19 02:34:59 2000
5162 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5163 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5164 Load Address: 0x00000000
5165 Entry Point: 0x00000000
5167 NOTE: for embedded systems where boot time is critical you can trade
5168 speed for memory and install an UNCOMPRESSED image instead: this
5169 needs more space in Flash, but boots much faster since it does not
5170 need to be uncompressed:
5172 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5173 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5174 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5175 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5176 > examples/uImage.TQM850L-uncompressed
5177 Image Name: 2.4.4 kernel for TQM850L
5178 Created: Wed Jul 19 02:34:59 2000
5179 Image Type: PowerPC Linux Kernel Image (uncompressed)
5180 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5181 Load Address: 0x00000000
5182 Entry Point: 0x00000000
5185 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5186 when your kernel is intended to use an initial ramdisk:
5188 -> tools/mkimage -n 'Simple Ramdisk Image' \
5189 > -A ppc -O linux -T ramdisk -C gzip \
5190 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5191 Image Name: Simple Ramdisk Image
5192 Created: Wed Jan 12 14:01:50 2000
5193 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5194 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5195 Load Address: 0x00000000
5196 Entry Point: 0x00000000
5198 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5199 option performs the converse operation of the mkimage's second form (the "-d"
5200 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5203 tools/dumpimage -i image -T type -p position data_file
5204 -i ==> extract from the 'image' a specific 'data_file'
5205 -T ==> set image type to 'type'
5206 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5209 Installing a Linux Image:
5210 -------------------------
5212 To downloading a U-Boot image over the serial (console) interface,
5213 you must convert the image to S-Record format:
5215 objcopy -I binary -O srec examples/image examples/image.srec
5217 The 'objcopy' does not understand the information in the U-Boot
5218 image header, so the resulting S-Record file will be relative to
5219 address 0x00000000. To load it to a given address, you need to
5220 specify the target address as 'offset' parameter with the 'loads'
5223 Example: install the image to address 0x40100000 (which on the
5224 TQM8xxL is in the first Flash bank):
5226 => erase 40100000 401FFFFF
5232 ## Ready for S-Record download ...
5233 ~>examples/image.srec
5234 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5236 15989 15990 15991 15992
5237 [file transfer complete]
5239 ## Start Addr = 0x00000000
5242 You can check the success of the download using the 'iminfo' command;
5243 this includes a checksum verification so you can be sure no data
5244 corruption happened:
5248 ## Checking Image at 40100000 ...
5249 Image Name: 2.2.13 for initrd on TQM850L
5250 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5251 Data Size: 335725 Bytes = 327 kB = 0 MB
5252 Load Address: 00000000
5253 Entry Point: 0000000c
5254 Verifying Checksum ... OK
5260 The "bootm" command is used to boot an application that is stored in
5261 memory (RAM or Flash). In case of a Linux kernel image, the contents
5262 of the "bootargs" environment variable is passed to the kernel as
5263 parameters. You can check and modify this variable using the
5264 "printenv" and "setenv" commands:
5267 => printenv bootargs
5268 bootargs=root=/dev/ram
5270 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5272 => printenv bootargs
5273 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5276 ## Booting Linux kernel at 40020000 ...
5277 Image Name: 2.2.13 for NFS on TQM850L
5278 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5279 Data Size: 381681 Bytes = 372 kB = 0 MB
5280 Load Address: 00000000
5281 Entry Point: 0000000c
5282 Verifying Checksum ... OK
5283 Uncompressing Kernel Image ... OK
5284 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
5285 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5286 time_init: decrementer frequency = 187500000/60
5287 Calibrating delay loop... 49.77 BogoMIPS
5288 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5291 If you want to boot a Linux kernel with initial RAM disk, you pass
5292 the memory addresses of both the kernel and the initrd image (PPBCOOT
5293 format!) to the "bootm" command:
5295 => imi 40100000 40200000
5297 ## Checking Image at 40100000 ...
5298 Image Name: 2.2.13 for initrd on TQM850L
5299 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5300 Data Size: 335725 Bytes = 327 kB = 0 MB
5301 Load Address: 00000000
5302 Entry Point: 0000000c
5303 Verifying Checksum ... OK
5305 ## Checking Image at 40200000 ...
5306 Image Name: Simple Ramdisk Image
5307 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5308 Data Size: 566530 Bytes = 553 kB = 0 MB
5309 Load Address: 00000000
5310 Entry Point: 00000000
5311 Verifying Checksum ... OK
5313 => bootm 40100000 40200000
5314 ## Booting Linux kernel at 40100000 ...
5315 Image Name: 2.2.13 for initrd on TQM850L
5316 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5317 Data Size: 335725 Bytes = 327 kB = 0 MB
5318 Load Address: 00000000
5319 Entry Point: 0000000c
5320 Verifying Checksum ... OK
5321 Uncompressing Kernel Image ... OK
5322 ## Loading RAMDisk Image at 40200000 ...
5323 Image Name: Simple Ramdisk Image
5324 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5325 Data Size: 566530 Bytes = 553 kB = 0 MB
5326 Load Address: 00000000
5327 Entry Point: 00000000
5328 Verifying Checksum ... OK
5329 Loading Ramdisk ... OK
5330 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
5331 Boot arguments: root=/dev/ram
5332 time_init: decrementer frequency = 187500000/60
5333 Calibrating delay loop... 49.77 BogoMIPS
5335 RAMDISK: Compressed image found at block 0
5336 VFS: Mounted root (ext2 filesystem).
5340 Boot Linux and pass a flat device tree:
5343 First, U-Boot must be compiled with the appropriate defines. See the section
5344 titled "Linux Kernel Interface" above for a more in depth explanation. The
5345 following is an example of how to start a kernel and pass an updated
5351 oft=oftrees/mpc8540ads.dtb
5352 => tftp $oftaddr $oft
5353 Speed: 1000, full duplex
5355 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5356 Filename 'oftrees/mpc8540ads.dtb'.
5357 Load address: 0x300000
5360 Bytes transferred = 4106 (100a hex)
5361 => tftp $loadaddr $bootfile
5362 Speed: 1000, full duplex
5364 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5366 Load address: 0x200000
5367 Loading:############
5369 Bytes transferred = 1029407 (fb51f hex)
5374 => bootm $loadaddr - $oftaddr
5375 ## Booting image at 00200000 ...
5376 Image Name: Linux-2.6.17-dirty
5377 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5378 Data Size: 1029343 Bytes = 1005.2 kB
5379 Load Address: 00000000
5380 Entry Point: 00000000
5381 Verifying Checksum ... OK
5382 Uncompressing Kernel Image ... OK
5383 Booting using flat device tree at 0x300000
5384 Using MPC85xx ADS machine description
5385 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5389 More About U-Boot Image Types:
5390 ------------------------------
5392 U-Boot supports the following image types:
5394 "Standalone Programs" are directly runnable in the environment
5395 provided by U-Boot; it is expected that (if they behave
5396 well) you can continue to work in U-Boot after return from
5397 the Standalone Program.
5398 "OS Kernel Images" are usually images of some Embedded OS which
5399 will take over control completely. Usually these programs
5400 will install their own set of exception handlers, device
5401 drivers, set up the MMU, etc. - this means, that you cannot
5402 expect to re-enter U-Boot except by resetting the CPU.
5403 "RAMDisk Images" are more or less just data blocks, and their
5404 parameters (address, size) are passed to an OS kernel that is
5406 "Multi-File Images" contain several images, typically an OS
5407 (Linux) kernel image and one or more data images like
5408 RAMDisks. This construct is useful for instance when you want
5409 to boot over the network using BOOTP etc., where the boot
5410 server provides just a single image file, but you want to get
5411 for instance an OS kernel and a RAMDisk image.
5413 "Multi-File Images" start with a list of image sizes, each
5414 image size (in bytes) specified by an "uint32_t" in network
5415 byte order. This list is terminated by an "(uint32_t)0".
5416 Immediately after the terminating 0 follow the images, one by
5417 one, all aligned on "uint32_t" boundaries (size rounded up to
5418 a multiple of 4 bytes).
5420 "Firmware Images" are binary images containing firmware (like
5421 U-Boot or FPGA images) which usually will be programmed to
5424 "Script files" are command sequences that will be executed by
5425 U-Boot's command interpreter; this feature is especially
5426 useful when you configure U-Boot to use a real shell (hush)
5427 as command interpreter.
5429 Booting the Linux zImage:
5430 -------------------------
5432 On some platforms, it's possible to boot Linux zImage. This is done
5433 using the "bootz" command. The syntax of "bootz" command is the same
5434 as the syntax of "bootm" command.
5436 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5437 kernel with raw initrd images. The syntax is slightly different, the
5438 address of the initrd must be augmented by it's size, in the following
5439 format: "<initrd addres>:<initrd size>".
5445 One of the features of U-Boot is that you can dynamically load and
5446 run "standalone" applications, which can use some resources of
5447 U-Boot like console I/O functions or interrupt services.
5449 Two simple examples are included with the sources:
5454 'examples/hello_world.c' contains a small "Hello World" Demo
5455 application; it is automatically compiled when you build U-Boot.
5456 It's configured to run at address 0x00040004, so you can play with it
5460 ## Ready for S-Record download ...
5461 ~>examples/hello_world.srec
5462 1 2 3 4 5 6 7 8 9 10 11 ...
5463 [file transfer complete]
5465 ## Start Addr = 0x00040004
5467 => go 40004 Hello World! This is a test.
5468 ## Starting application at 0x00040004 ...
5479 Hit any key to exit ...
5481 ## Application terminated, rc = 0x0
5483 Another example, which demonstrates how to register a CPM interrupt
5484 handler with the U-Boot code, can be found in 'examples/timer.c'.
5485 Here, a CPM timer is set up to generate an interrupt every second.
5486 The interrupt service routine is trivial, just printing a '.'
5487 character, but this is just a demo program. The application can be
5488 controlled by the following keys:
5490 ? - print current values og the CPM Timer registers
5491 b - enable interrupts and start timer
5492 e - stop timer and disable interrupts
5493 q - quit application
5496 ## Ready for S-Record download ...
5497 ~>examples/timer.srec
5498 1 2 3 4 5 6 7 8 9 10 11 ...
5499 [file transfer complete]
5501 ## Start Addr = 0x00040004
5504 ## Starting application at 0x00040004 ...
5507 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5510 [q, b, e, ?] Set interval 1000000 us
5513 [q, b, e, ?] ........
5514 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5517 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5520 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5523 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5525 [q, b, e, ?] ...Stopping timer
5527 [q, b, e, ?] ## Application terminated, rc = 0x0
5533 Over time, many people have reported problems when trying to use the
5534 "minicom" terminal emulation program for serial download. I (wd)
5535 consider minicom to be broken, and recommend not to use it. Under
5536 Unix, I recommend to use C-Kermit for general purpose use (and
5537 especially for kermit binary protocol download ("loadb" command), and
5538 use "cu" for S-Record download ("loads" command). See
5539 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5540 for help with kermit.
5543 Nevertheless, if you absolutely want to use it try adding this
5544 configuration to your "File transfer protocols" section:
5546 Name Program Name U/D FullScr IO-Red. Multi
5547 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5548 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5554 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5555 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5557 Building requires a cross environment; it is known to work on
5558 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5559 need gmake since the Makefiles are not compatible with BSD make).
5560 Note that the cross-powerpc package does not install include files;
5561 attempting to build U-Boot will fail because <machine/ansi.h> is
5562 missing. This file has to be installed and patched manually:
5564 # cd /usr/pkg/cross/powerpc-netbsd/include
5566 # ln -s powerpc machine
5567 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5568 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5570 Native builds *don't* work due to incompatibilities between native
5571 and U-Boot include files.
5573 Booting assumes that (the first part of) the image booted is a
5574 stage-2 loader which in turn loads and then invokes the kernel
5575 proper. Loader sources will eventually appear in the NetBSD source
5576 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5577 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5580 Implementation Internals:
5581 =========================
5583 The following is not intended to be a complete description of every
5584 implementation detail. However, it should help to understand the
5585 inner workings of U-Boot and make it easier to port it to custom
5589 Initial Stack, Global Data:
5590 ---------------------------
5592 The implementation of U-Boot is complicated by the fact that U-Boot
5593 starts running out of ROM (flash memory), usually without access to
5594 system RAM (because the memory controller is not initialized yet).
5595 This means that we don't have writable Data or BSS segments, and BSS
5596 is not initialized as zero. To be able to get a C environment working
5597 at all, we have to allocate at least a minimal stack. Implementation
5598 options for this are defined and restricted by the CPU used: Some CPU
5599 models provide on-chip memory (like the IMMR area on MPC8xx and
5600 MPC826x processors), on others (parts of) the data cache can be
5601 locked as (mis-) used as memory, etc.
5603 Chris Hallinan posted a good summary of these issues to the
5604 U-Boot mailing list:
5606 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5607 From: "Chris Hallinan" <clh@net1plus.com>
5608 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5611 Correct me if I'm wrong, folks, but the way I understand it
5612 is this: Using DCACHE as initial RAM for Stack, etc, does not
5613 require any physical RAM backing up the cache. The cleverness
5614 is that the cache is being used as a temporary supply of
5615 necessary storage before the SDRAM controller is setup. It's
5616 beyond the scope of this list to explain the details, but you
5617 can see how this works by studying the cache architecture and
5618 operation in the architecture and processor-specific manuals.
5620 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5621 is another option for the system designer to use as an
5622 initial stack/RAM area prior to SDRAM being available. Either
5623 option should work for you. Using CS 4 should be fine if your
5624 board designers haven't used it for something that would
5625 cause you grief during the initial boot! It is frequently not
5628 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5629 with your processor/board/system design. The default value
5630 you will find in any recent u-boot distribution in
5631 walnut.h should work for you. I'd set it to a value larger
5632 than your SDRAM module. If you have a 64MB SDRAM module, set
5633 it above 400_0000. Just make sure your board has no resources
5634 that are supposed to respond to that address! That code in
5635 start.S has been around a while and should work as is when
5636 you get the config right.
5641 It is essential to remember this, since it has some impact on the C
5642 code for the initialization procedures:
5644 * Initialized global data (data segment) is read-only. Do not attempt
5647 * Do not use any uninitialized global data (or implicitly initialized
5648 as zero data - BSS segment) at all - this is undefined, initiali-
5649 zation is performed later (when relocating to RAM).
5651 * Stack space is very limited. Avoid big data buffers or things like
5654 Having only the stack as writable memory limits means we cannot use
5655 normal global data to share information between the code. But it
5656 turned out that the implementation of U-Boot can be greatly
5657 simplified by making a global data structure (gd_t) available to all
5658 functions. We could pass a pointer to this data as argument to _all_
5659 functions, but this would bloat the code. Instead we use a feature of
5660 the GCC compiler (Global Register Variables) to share the data: we
5661 place a pointer (gd) to the global data into a register which we
5662 reserve for this purpose.
5664 When choosing a register for such a purpose we are restricted by the
5665 relevant (E)ABI specifications for the current architecture, and by
5666 GCC's implementation.
5668 For PowerPC, the following registers have specific use:
5670 R2: reserved for system use
5671 R3-R4: parameter passing and return values
5672 R5-R10: parameter passing
5673 R13: small data area pointer
5677 (U-Boot also uses R12 as internal GOT pointer. r12
5678 is a volatile register so r12 needs to be reset when
5679 going back and forth between asm and C)
5681 ==> U-Boot will use R2 to hold a pointer to the global data
5683 Note: on PPC, we could use a static initializer (since the
5684 address of the global data structure is known at compile time),
5685 but it turned out that reserving a register results in somewhat
5686 smaller code - although the code savings are not that big (on
5687 average for all boards 752 bytes for the whole U-Boot image,
5688 624 text + 127 data).
5690 On ARM, the following registers are used:
5692 R0: function argument word/integer result
5693 R1-R3: function argument word
5694 R9: platform specific
5695 R10: stack limit (used only if stack checking is enabled)
5696 R11: argument (frame) pointer
5697 R12: temporary workspace
5700 R15: program counter
5702 ==> U-Boot will use R9 to hold a pointer to the global data
5704 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5706 On Nios II, the ABI is documented here:
5707 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5709 ==> U-Boot will use gp to hold a pointer to the global data
5711 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5712 to access small data sections, so gp is free.
5714 On NDS32, the following registers are used:
5716 R0-R1: argument/return
5718 R15: temporary register for assembler
5719 R16: trampoline register
5720 R28: frame pointer (FP)
5721 R29: global pointer (GP)
5722 R30: link register (LP)
5723 R31: stack pointer (SP)
5724 PC: program counter (PC)
5726 ==> U-Boot will use R10 to hold a pointer to the global data
5728 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5729 or current versions of GCC may "optimize" the code too much.
5734 U-Boot runs in system state and uses physical addresses, i.e. the
5735 MMU is not used either for address mapping nor for memory protection.
5737 The available memory is mapped to fixed addresses using the memory
5738 controller. In this process, a contiguous block is formed for each
5739 memory type (Flash, SDRAM, SRAM), even when it consists of several
5740 physical memory banks.
5742 U-Boot is installed in the first 128 kB of the first Flash bank (on
5743 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5744 booting and sizing and initializing DRAM, the code relocates itself
5745 to the upper end of DRAM. Immediately below the U-Boot code some
5746 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5747 configuration setting]. Below that, a structure with global Board
5748 Info data is placed, followed by the stack (growing downward).
5750 Additionally, some exception handler code is copied to the low 8 kB
5751 of DRAM (0x00000000 ... 0x00001FFF).
5753 So a typical memory configuration with 16 MB of DRAM could look like
5756 0x0000 0000 Exception Vector code
5759 0x0000 2000 Free for Application Use
5765 0x00FB FF20 Monitor Stack (Growing downward)
5766 0x00FB FFAC Board Info Data and permanent copy of global data
5767 0x00FC 0000 Malloc Arena
5770 0x00FE 0000 RAM Copy of Monitor Code
5771 ... eventually: LCD or video framebuffer
5772 ... eventually: pRAM (Protected RAM - unchanged by reset)
5773 0x00FF FFFF [End of RAM]
5776 System Initialization:
5777 ----------------------
5779 In the reset configuration, U-Boot starts at the reset entry point
5780 (on most PowerPC systems at address 0x00000100). Because of the reset
5781 configuration for CS0# this is a mirror of the on board Flash memory.
5782 To be able to re-map memory U-Boot then jumps to its link address.
5783 To be able to implement the initialization code in C, a (small!)
5784 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5785 which provide such a feature like MPC8xx or MPC8260), or in a locked
5786 part of the data cache. After that, U-Boot initializes the CPU core,
5787 the caches and the SIU.
5789 Next, all (potentially) available memory banks are mapped using a
5790 preliminary mapping. For example, we put them on 512 MB boundaries
5791 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5792 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5793 programmed for SDRAM access. Using the temporary configuration, a
5794 simple memory test is run that determines the size of the SDRAM
5797 When there is more than one SDRAM bank, and the banks are of
5798 different size, the largest is mapped first. For equal size, the first
5799 bank (CS2#) is mapped first. The first mapping is always for address
5800 0x00000000, with any additional banks following immediately to create
5801 contiguous memory starting from 0.
5803 Then, the monitor installs itself at the upper end of the SDRAM area
5804 and allocates memory for use by malloc() and for the global Board
5805 Info data; also, the exception vector code is copied to the low RAM
5806 pages, and the final stack is set up.
5808 Only after this relocation will you have a "normal" C environment;
5809 until that you are restricted in several ways, mostly because you are
5810 running from ROM, and because the code will have to be relocated to a
5814 U-Boot Porting Guide:
5815 ----------------------
5817 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5821 int main(int argc, char *argv[])
5823 sighandler_t no_more_time;
5825 signal(SIGALRM, no_more_time);
5826 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5828 if (available_money > available_manpower) {
5829 Pay consultant to port U-Boot;
5833 Download latest U-Boot source;
5835 Subscribe to u-boot mailing list;
5838 email("Hi, I am new to U-Boot, how do I get started?");
5841 Read the README file in the top level directory;
5842 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5843 Read applicable doc/*.README;
5844 Read the source, Luke;
5845 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5848 if (available_money > toLocalCurrency ($2500))
5851 Add a lot of aggravation and time;
5853 if (a similar board exists) { /* hopefully... */
5854 cp -a board/<similar> board/<myboard>
5855 cp include/configs/<similar>.h include/configs/<myboard>.h
5857 Create your own board support subdirectory;
5858 Create your own board include/configs/<myboard>.h file;
5860 Edit new board/<myboard> files
5861 Edit new include/configs/<myboard>.h
5866 Add / modify source code;
5870 email("Hi, I am having problems...");
5872 Send patch file to the U-Boot email list;
5873 if (reasonable critiques)
5874 Incorporate improvements from email list code review;
5876 Defend code as written;
5882 void no_more_time (int sig)
5891 All contributions to U-Boot should conform to the Linux kernel
5892 coding style; see the file "Documentation/CodingStyle" and the script
5893 "scripts/Lindent" in your Linux kernel source directory.
5895 Source files originating from a different project (for example the
5896 MTD subsystem) are generally exempt from these guidelines and are not
5897 reformatted to ease subsequent migration to newer versions of those
5900 Please note that U-Boot is implemented in C (and to some small parts in
5901 Assembler); no C++ is used, so please do not use C++ style comments (//)
5904 Please also stick to the following formatting rules:
5905 - remove any trailing white space
5906 - use TAB characters for indentation and vertical alignment, not spaces
5907 - make sure NOT to use DOS '\r\n' line feeds
5908 - do not add more than 2 consecutive empty lines to source files
5909 - do not add trailing empty lines to source files
5911 Submissions which do not conform to the standards may be returned
5912 with a request to reformat the changes.
5918 Since the number of patches for U-Boot is growing, we need to
5919 establish some rules. Submissions which do not conform to these rules
5920 may be rejected, even when they contain important and valuable stuff.
5922 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5924 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5925 see http://lists.denx.de/mailman/listinfo/u-boot
5927 When you send a patch, please include the following information with
5930 * For bug fixes: a description of the bug and how your patch fixes
5931 this bug. Please try to include a way of demonstrating that the
5932 patch actually fixes something.
5934 * For new features: a description of the feature and your
5937 * A CHANGELOG entry as plaintext (separate from the patch)
5939 * For major contributions, add a MAINTAINERS file with your
5940 information and associated file and directory references.
5942 * When you add support for a new board, don't forget to add a
5943 maintainer e-mail address to the boards.cfg file, too.
5945 * If your patch adds new configuration options, don't forget to
5946 document these in the README file.
5948 * The patch itself. If you are using git (which is *strongly*
5949 recommended) you can easily generate the patch using the
5950 "git format-patch". If you then use "git send-email" to send it to
5951 the U-Boot mailing list, you will avoid most of the common problems
5952 with some other mail clients.
5954 If you cannot use git, use "diff -purN OLD NEW". If your version of
5955 diff does not support these options, then get the latest version of
5958 The current directory when running this command shall be the parent
5959 directory of the U-Boot source tree (i. e. please make sure that
5960 your patch includes sufficient directory information for the
5963 We prefer patches as plain text. MIME attachments are discouraged,
5964 and compressed attachments must not be used.
5966 * If one logical set of modifications affects or creates several
5967 files, all these changes shall be submitted in a SINGLE patch file.
5969 * Changesets that contain different, unrelated modifications shall be
5970 submitted as SEPARATE patches, one patch per changeset.
5975 * Before sending the patch, run the buildman script on your patched
5976 source tree and make sure that no errors or warnings are reported
5977 for any of the boards.
5979 * Keep your modifications to the necessary minimum: A patch
5980 containing several unrelated changes or arbitrary reformats will be
5981 returned with a request to re-formatting / split it.
5983 * If you modify existing code, make sure that your new code does not
5984 add to the memory footprint of the code ;-) Small is beautiful!
5985 When adding new features, these should compile conditionally only
5986 (using #ifdef), and the resulting code with the new feature
5987 disabled must not need more memory than the old code without your
5990 * Remember that there is a size limit of 100 kB per message on the
5991 u-boot mailing list. Bigger patches will be moderated. If they are
5992 reasonable and not too big, they will be acknowledged. But patches
5993 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob