2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG file to find out who contributed
38 the specific port. In addition, there are various MAINTAINERS files
39 scattered throughout the U-Boot source identifying the people or
40 companies responsible for various boards and subsystems.
42 Note: As of August, 2010, there is no longer a CHANGELOG file in the
43 actual U-Boot source tree; however, it can be created dynamically
44 from the Git log using:
52 In case you have questions about, problems with or contributions for
53 U-Boot, you should send a message to the U-Boot mailing list at
54 <u-boot@lists.denx.de>. There is also an archive of previous traffic
55 on the mailing list - please search the archive before asking FAQ's.
56 Please see http://lists.denx.de/pipermail/u-boot and
57 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
60 Where to get source code:
61 =========================
63 The U-Boot source code is maintained in the Git repository at
64 git://www.denx.de/git/u-boot.git ; you can browse it online at
65 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
67 The "snapshot" links on this page allow you to download tarballs of
68 any version you might be interested in. Official releases are also
69 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
72 Pre-built (and tested) images are available from
73 ftp://ftp.denx.de/pub/u-boot/images/
79 - start from 8xxrom sources
80 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
82 - make it easier to add custom boards
83 - make it possible to add other [PowerPC] CPUs
84 - extend functions, especially:
85 * Provide extended interface to Linux boot loader
88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
89 - create ARMBoot project (http://sourceforge.net/projects/armboot)
90 - add other CPU families (starting with ARM)
91 - create U-Boot project (http://sourceforge.net/projects/u-boot)
92 - current project page: see http://www.denx.de/wiki/U-Boot
98 The "official" name of this project is "Das U-Boot". The spelling
99 "U-Boot" shall be used in all written text (documentation, comments
100 in source files etc.). Example:
102 This is the README file for the U-Boot project.
104 File names etc. shall be based on the string "u-boot". Examples:
106 include/asm-ppc/u-boot.h
108 #include <asm/u-boot.h>
110 Variable names, preprocessor constants etc. shall be either based on
111 the string "u_boot" or on "U_BOOT". Example:
113 U_BOOT_VERSION u_boot_logo
114 IH_OS_U_BOOT u_boot_hush_start
120 Starting with the release in October 2008, the names of the releases
121 were changed from numerical release numbers without deeper meaning
122 into a time stamp based numbering. Regular releases are identified by
123 names consisting of the calendar year and month of the release date.
124 Additional fields (if present) indicate release candidates or bug fix
125 releases in "stable" maintenance trees.
128 U-Boot v2009.11 - Release November 2009
129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
130 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
136 /arch Architecture specific files
137 /arc Files generic to ARC architecture
138 /arm Files generic to ARM architecture
139 /avr32 Files generic to AVR32 architecture
140 /blackfin Files generic to Analog Devices Blackfin architecture
141 /m68k Files generic to m68k architecture
142 /microblaze Files generic to microblaze architecture
143 /mips Files generic to MIPS architecture
144 /nds32 Files generic to NDS32 architecture
145 /nios2 Files generic to Altera NIOS2 architecture
146 /openrisc Files generic to OpenRISC architecture
147 /powerpc Files generic to PowerPC architecture
148 /sandbox Files generic to HW-independent "sandbox"
149 /sh Files generic to SH architecture
150 /sparc Files generic to SPARC architecture
151 /x86 Files generic to x86 architecture
152 /api Machine/arch independent API for external apps
153 /board Board dependent files
154 /cmd U-Boot commands functions
155 /common Misc architecture independent functions
156 /configs Board default configuration files
157 /disk Code for disk drive partition handling
158 /doc Documentation (don't expect too much)
159 /drivers Commonly used device drivers
160 /dts Contains Makefile for building internal U-Boot fdt.
161 /examples Example code for standalone applications, etc.
162 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
163 /include Header Files
164 /lib Library routines generic to all architectures
165 /Licenses Various license files
167 /post Power On Self Test
168 /scripts Various build scripts and Makefiles
169 /test Various unit test files
170 /tools Tools to build S-Record or U-Boot images, etc.
172 Software Configuration:
173 =======================
175 Configuration is usually done using C preprocessor defines; the
176 rationale behind that is to avoid dead code whenever possible.
178 There are two classes of configuration variables:
180 * Configuration _OPTIONS_:
181 These are selectable by the user and have names beginning with
184 * Configuration _SETTINGS_:
185 These depend on the hardware etc. and should not be meddled with if
186 you don't know what you're doing; they have names beginning with
189 Previously, all configuration was done by hand, which involved creating
190 symbolic links and editing configuration files manually. More recently,
191 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
192 allowing you to use the "make menuconfig" command to configure your
196 Selection of Processor Architecture and Board Type:
197 ---------------------------------------------------
199 For all supported boards there are ready-to-use default
200 configurations available; just type "make <board_name>_defconfig".
202 Example: For a TQM823L module type:
205 make TQM823L_defconfig
207 Note: If you're looking for the default configuration file for a board
208 you're sure used to be there but is now missing, check the file
209 doc/README.scrapyard for a list of no longer supported boards.
214 U-Boot can be built natively to run on a Linux host using the 'sandbox'
215 board. This allows feature development which is not board- or architecture-
216 specific to be undertaken on a native platform. The sandbox is also used to
217 run some of U-Boot's tests.
219 See board/sandbox/README.sandbox for more details.
222 Board Initialisation Flow:
223 --------------------------
225 This is the intended start-up flow for boards. This should apply for both
226 SPL and U-Boot proper (i.e. they both follow the same rules).
228 Note: "SPL" stands for "Secondary Program Loader," which is explained in
229 more detail later in this file.
231 At present, SPL mostly uses a separate code path, but the function names
232 and roles of each function are the same. Some boards or architectures
233 may not conform to this. At least most ARM boards which use
234 CONFIG_SPL_FRAMEWORK conform to this.
236 Execution typically starts with an architecture-specific (and possibly
237 CPU-specific) start.S file, such as:
239 - arch/arm/cpu/armv7/start.S
240 - arch/powerpc/cpu/mpc83xx/start.S
241 - arch/mips/cpu/start.S
243 and so on. From there, three functions are called; the purpose and
244 limitations of each of these functions are described below.
247 - purpose: essential init to permit execution to reach board_init_f()
248 - no global_data or BSS
249 - there is no stack (ARMv7 may have one but it will soon be removed)
250 - must not set up SDRAM or use console
251 - must only do the bare minimum to allow execution to continue to
253 - this is almost never needed
254 - return normally from this function
257 - purpose: set up the machine ready for running board_init_r():
258 i.e. SDRAM and serial UART
259 - global_data is available
261 - BSS is not available, so you cannot use global/static variables,
262 only stack variables and global_data
264 Non-SPL-specific notes:
265 - dram_init() is called to set up DRAM. If already done in SPL this
269 - you can override the entire board_init_f() function with your own
271 - preloader_console_init() can be called here in extremis
272 - should set up SDRAM, and anything needed to make the UART work
273 - these is no need to clear BSS, it will be done by crt0.S
274 - must return normally from this function (don't call board_init_r()
277 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
278 this point the stack and global_data are relocated to below
279 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
283 - purpose: main execution, common code
284 - global_data is available
286 - BSS is available, all static/global variables can be used
287 - execution eventually continues to main_loop()
289 Non-SPL-specific notes:
290 - U-Boot is relocated to the top of memory and is now running from
294 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
295 CONFIG_SPL_STACK_R_ADDR points into SDRAM
296 - preloader_console_init() can be called here - typically this is
297 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
298 spl_board_init() function containing this call
299 - loads U-Boot or (in falcon mode) Linux
303 Configuration Options:
304 ----------------------
306 Configuration depends on the combination of board and CPU type; all
307 such information is kept in a configuration file
308 "include/configs/<board_name>.h".
310 Example: For a TQM823L module, all configuration settings are in
311 "include/configs/TQM823L.h".
314 Many of the options are named exactly as the corresponding Linux
315 kernel configuration options. The intention is to make it easier to
316 build a config tool - later.
319 The following options need to be configured:
321 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
323 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
325 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
326 Define exactly one, e.g. CONFIG_ATSTK1002
328 - CPU Module Type: (if CONFIG_COGENT is defined)
329 Define exactly one of
331 --- FIXME --- not tested yet:
332 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
333 CONFIG_CMA287_23, CONFIG_CMA287_50
335 - Motherboard Type: (if CONFIG_COGENT is defined)
336 Define exactly one of
337 CONFIG_CMA101, CONFIG_CMA102
339 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
340 Define one or more of
343 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
344 Define one or more of
345 CONFIG_LCD_HEARTBEAT - update a character position on
346 the LCD display every second with
349 - Marvell Family Member
350 CONFIG_SYS_MVFS - define it if you want to enable
351 multiple fs option at one time
352 for marvell soc family
354 - 8xx CPU Options: (if using an MPC8xx CPU)
355 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
356 get_gclk_freq() cannot work
357 e.g. if there is no 32KHz
358 reference PIT/RTC clock
359 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
362 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
363 CONFIG_SYS_8xx_CPUCLK_MIN
364 CONFIG_SYS_8xx_CPUCLK_MAX
365 CONFIG_8xx_CPUCLK_DEFAULT
366 See doc/README.MPC866
368 CONFIG_SYS_MEASURE_CPUCLK
370 Define this to measure the actual CPU clock instead
371 of relying on the correctness of the configured
372 values. Mostly useful for board bringup to make sure
373 the PLL is locked at the intended frequency. Note
374 that this requires a (stable) reference clock (32 kHz
375 RTC clock or CONFIG_SYS_8XX_XIN)
377 CONFIG_SYS_DELAYED_ICACHE
379 Define this option if you want to enable the
380 ICache only when Code runs from RAM.
385 Specifies that the core is a 64-bit PowerPC implementation (implements
386 the "64" category of the Power ISA). This is necessary for ePAPR
387 compliance, among other possible reasons.
389 CONFIG_SYS_FSL_TBCLK_DIV
391 Defines the core time base clock divider ratio compared to the
392 system clock. On most PQ3 devices this is 8, on newer QorIQ
393 devices it can be 16 or 32. The ratio varies from SoC to Soc.
395 CONFIG_SYS_FSL_PCIE_COMPAT
397 Defines the string to utilize when trying to match PCIe device
398 tree nodes for the given platform.
400 CONFIG_SYS_PPC_E500_DEBUG_TLB
402 Enables a temporary TLB entry to be used during boot to work
403 around limitations in e500v1 and e500v2 external debugger
404 support. This reduces the portions of the boot code where
405 breakpoints and single stepping do not work. The value of this
406 symbol should be set to the TLB1 entry to be used for this
409 CONFIG_SYS_FSL_ERRATUM_A004510
411 Enables a workaround for erratum A004510. If set,
412 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
413 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
415 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
416 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
418 Defines one or two SoC revisions (low 8 bits of SVR)
419 for which the A004510 workaround should be applied.
421 The rest of SVR is either not relevant to the decision
422 of whether the erratum is present (e.g. p2040 versus
423 p2041) or is implied by the build target, which controls
424 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
426 See Freescale App Note 4493 for more information about
429 CONFIG_A003399_NOR_WORKAROUND
430 Enables a workaround for IFC erratum A003399. It is only
431 required during NOR boot.
433 CONFIG_A008044_WORKAROUND
434 Enables a workaround for T1040/T1042 erratum A008044. It is only
435 required during NAND boot and valid for Rev 1.0 SoC revision
437 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
439 This is the value to write into CCSR offset 0x18600
440 according to the A004510 workaround.
442 CONFIG_SYS_FSL_DSP_DDR_ADDR
443 This value denotes start offset of DDR memory which is
444 connected exclusively to the DSP cores.
446 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
447 This value denotes start offset of M2 memory
448 which is directly connected to the DSP core.
450 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
451 This value denotes start offset of M3 memory which is directly
452 connected to the DSP core.
454 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
455 This value denotes start offset of DSP CCSR space.
457 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
458 Single Source Clock is clocking mode present in some of FSL SoC's.
459 In this mode, a single differential clock is used to supply
460 clocks to the sysclock, ddrclock and usbclock.
462 CONFIG_SYS_CPC_REINIT_F
463 This CONFIG is defined when the CPC is configured as SRAM at the
464 time of U-Boot entry and is required to be re-initialized.
467 Indicates this SoC supports deep sleep feature. If deep sleep is
468 supported, core will start to execute uboot when wakes up.
470 - Generic CPU options:
471 CONFIG_SYS_GENERIC_GLOBAL_DATA
472 Defines global data is initialized in generic board board_init_f().
473 If this macro is defined, global data is created and cleared in
474 generic board board_init_f(). Without this macro, architecture/board
475 should initialize global data before calling board_init_f().
477 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
479 Defines the endianess of the CPU. Implementation of those
480 values is arch specific.
483 Freescale DDR driver in use. This type of DDR controller is
484 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
487 CONFIG_SYS_FSL_DDR_ADDR
488 Freescale DDR memory-mapped register base.
490 CONFIG_SYS_FSL_DDR_EMU
491 Specify emulator support for DDR. Some DDR features such as
492 deskew training are not available.
494 CONFIG_SYS_FSL_DDRC_GEN1
495 Freescale DDR1 controller.
497 CONFIG_SYS_FSL_DDRC_GEN2
498 Freescale DDR2 controller.
500 CONFIG_SYS_FSL_DDRC_GEN3
501 Freescale DDR3 controller.
503 CONFIG_SYS_FSL_DDRC_GEN4
504 Freescale DDR4 controller.
506 CONFIG_SYS_FSL_DDRC_ARM_GEN3
507 Freescale DDR3 controller for ARM-based SoCs.
510 Board config to use DDR1. It can be enabled for SoCs with
511 Freescale DDR1 or DDR2 controllers, depending on the board
515 Board config to use DDR2. It can be enabled for SoCs with
516 Freescale DDR2 or DDR3 controllers, depending on the board
520 Board config to use DDR3. It can be enabled for SoCs with
521 Freescale DDR3 or DDR3L controllers.
524 Board config to use DDR3L. It can be enabled for SoCs with
528 Board config to use DDR4. It can be enabled for SoCs with
531 CONFIG_SYS_FSL_IFC_BE
532 Defines the IFC controller register space as Big Endian
534 CONFIG_SYS_FSL_IFC_LE
535 Defines the IFC controller register space as Little Endian
537 CONFIG_SYS_FSL_PBL_PBI
538 It enables addition of RCW (Power on reset configuration) in built image.
539 Please refer doc/README.pblimage for more details
541 CONFIG_SYS_FSL_PBL_RCW
542 It adds PBI(pre-boot instructions) commands in u-boot build image.
543 PBI commands can be used to configure SoC before it starts the execution.
544 Please refer doc/README.pblimage for more details
547 It adds a target to create boot binary having SPL binary in PBI format
548 concatenated with u-boot binary.
550 CONFIG_SYS_FSL_DDR_BE
551 Defines the DDR controller register space as Big Endian
553 CONFIG_SYS_FSL_DDR_LE
554 Defines the DDR controller register space as Little Endian
556 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
557 Physical address from the view of DDR controllers. It is the
558 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
559 it could be different for ARM SoCs.
561 CONFIG_SYS_FSL_DDR_INTLV_256B
562 DDR controller interleaving on 256-byte. This is a special
563 interleaving mode, handled by Dickens for Freescale layerscape
566 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
567 Number of controllers used as main memory.
569 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
570 Number of controllers used for other than main memory.
572 CONFIG_SYS_FSL_HAS_DP_DDR
573 Defines the SoC has DP-DDR used for DPAA.
575 CONFIG_SYS_FSL_SEC_BE
576 Defines the SEC controller register space as Big Endian
578 CONFIG_SYS_FSL_SEC_LE
579 Defines the SEC controller register space as Little Endian
582 CONFIG_SYS_INIT_SP_OFFSET
584 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
585 pointer. This is needed for the temporary stack before
588 CONFIG_SYS_MIPS_CACHE_MODE
590 Cache operation mode for the MIPS CPU.
591 See also arch/mips/include/asm/mipsregs.h.
593 CONF_CM_CACHABLE_NO_WA
596 CONF_CM_CACHABLE_NONCOHERENT
600 CONF_CM_CACHABLE_ACCELERATED
602 CONFIG_SYS_XWAY_EBU_BOOTCFG
604 Special option for Lantiq XWAY SoCs for booting from NOR flash.
605 See also arch/mips/cpu/mips32/start.S.
607 CONFIG_XWAY_SWAP_BYTES
609 Enable compilation of tools/xway-swap-bytes needed for Lantiq
610 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
611 be swapped if a flash programmer is used.
614 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
616 Select high exception vectors of the ARM core, e.g., do not
617 clear the V bit of the c1 register of CP15.
619 CONFIG_SYS_THUMB_BUILD
621 Use this flag to build U-Boot using the Thumb instruction
622 set for ARM architectures. Thumb instruction set provides
623 better code density. For ARM architectures that support
624 Thumb2 this flag will result in Thumb2 code generated by
627 CONFIG_ARM_ERRATA_716044
628 CONFIG_ARM_ERRATA_742230
629 CONFIG_ARM_ERRATA_743622
630 CONFIG_ARM_ERRATA_751472
631 CONFIG_ARM_ERRATA_761320
632 CONFIG_ARM_ERRATA_773022
633 CONFIG_ARM_ERRATA_774769
634 CONFIG_ARM_ERRATA_794072
636 If set, the workarounds for these ARM errata are applied early
637 during U-Boot startup. Note that these options force the
638 workarounds to be applied; no CPU-type/version detection
639 exists, unlike the similar options in the Linux kernel. Do not
640 set these options unless they apply!
643 Generic timer clock source frequency.
645 COUNTER_FREQUENCY_REAL
646 Generic timer clock source frequency if the real clock is
647 different from COUNTER_FREQUENCY, and can only be determined
650 NOTE: The following can be machine specific errata. These
651 do have ability to provide rudimentary version and machine
652 specific checks, but expect no product checks.
653 CONFIG_ARM_ERRATA_430973
654 CONFIG_ARM_ERRATA_454179
655 CONFIG_ARM_ERRATA_621766
656 CONFIG_ARM_ERRATA_798870
657 CONFIG_ARM_ERRATA_801819
660 CONFIG_TEGRA_SUPPORT_NON_SECURE
662 Support executing U-Boot in non-secure (NS) mode. Certain
663 impossible actions will be skipped if the CPU is in NS mode,
664 such as ARM architectural timer initialization.
666 - Linux Kernel Interface:
669 U-Boot stores all clock information in Hz
670 internally. For binary compatibility with older Linux
671 kernels (which expect the clocks passed in the
672 bd_info data to be in MHz) the environment variable
673 "clocks_in_mhz" can be defined so that U-Boot
674 converts clock data to MHZ before passing it to the
676 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
677 "clocks_in_mhz=1" is automatically included in the
680 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
682 When transferring memsize parameter to Linux, some versions
683 expect it to be in bytes, others in MB.
684 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
688 New kernel versions are expecting firmware settings to be
689 passed using flattened device trees (based on open firmware
693 * New libfdt-based support
694 * Adds the "fdt" command
695 * The bootm command automatically updates the fdt
697 OF_CPU - The proper name of the cpus node (only required for
698 MPC512X and MPC5xxx based boards).
699 OF_SOC - The proper name of the soc node (only required for
700 MPC512X and MPC5xxx based boards).
701 OF_TBCLK - The timebase frequency.
702 OF_STDOUT_PATH - The path to the console device
704 boards with QUICC Engines require OF_QE to set UCC MAC
707 CONFIG_OF_BOARD_SETUP
709 Board code has addition modification that it wants to make
710 to the flat device tree before handing it off to the kernel
712 CONFIG_OF_SYSTEM_SETUP
714 Other code has addition modification that it wants to make
715 to the flat device tree before handing it off to the kernel.
716 This causes ft_system_setup() to be called before booting
721 This define fills in the correct boot CPU in the boot
722 param header, the default value is zero if undefined.
726 U-Boot can detect if an IDE device is present or not.
727 If not, and this new config option is activated, U-Boot
728 removes the ATA node from the DTS before booting Linux,
729 so the Linux IDE driver does not probe the device and
730 crash. This is needed for buggy hardware (uc101) where
731 no pull down resistor is connected to the signal IDE5V_DD7.
733 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
735 This setting is mandatory for all boards that have only one
736 machine type and must be used to specify the machine type
737 number as it appears in the ARM machine registry
738 (see http://www.arm.linux.org.uk/developer/machines/).
739 Only boards that have multiple machine types supported
740 in a single configuration file and the machine type is
741 runtime discoverable, do not have to use this setting.
743 - vxWorks boot parameters:
745 bootvx constructs a valid bootline using the following
746 environments variables: bootdev, bootfile, ipaddr, netmask,
747 serverip, gatewayip, hostname, othbootargs.
748 It loads the vxWorks image pointed bootfile.
750 Note: If a "bootargs" environment is defined, it will overwride
751 the defaults discussed just above.
753 - Cache Configuration:
754 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
755 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
756 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
758 - Cache Configuration for ARM:
759 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
761 CONFIG_SYS_PL310_BASE - Physical base address of PL310
762 controller register space
767 Define this if you want support for Amba PrimeCell PL010 UARTs.
771 Define this if you want support for Amba PrimeCell PL011 UARTs.
775 If you have Amba PrimeCell PL011 UARTs, set this variable to
776 the clock speed of the UARTs.
780 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
781 define this to a list of base addresses for each (supported)
782 port. See e.g. include/configs/versatile.h
784 CONFIG_SERIAL_HW_FLOW_CONTROL
786 Define this variable to enable hw flow control in serial driver.
787 Current user of this option is drivers/serial/nsl16550.c driver
790 Depending on board, define exactly one serial port
791 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
792 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
793 console by defining CONFIG_8xx_CONS_NONE
795 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
796 port routines must be defined elsewhere
797 (i.e. serial_init(), serial_getc(), ...)
800 Enables console device for a color framebuffer. Needs following
801 defines (cf. smiLynxEM, i8042)
802 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
804 VIDEO_HW_RECTFILL graphic chip supports
807 VIDEO_HW_BITBLT graphic chip supports
808 bit-blit (cf. smiLynxEM)
809 VIDEO_VISIBLE_COLS visible pixel columns
811 VIDEO_VISIBLE_ROWS visible pixel rows
812 VIDEO_PIXEL_SIZE bytes per pixel
813 VIDEO_DATA_FORMAT graphic data format
814 (0-5, cf. cfb_console.c)
815 VIDEO_FB_ADRS framebuffer address
816 VIDEO_KBD_INIT_FCT keyboard int fct
817 (i.e. rx51_kp_init())
818 VIDEO_TSTC_FCT test char fct
820 VIDEO_GETC_FCT get char fct
822 CONFIG_VIDEO_LOGO display Linux logo in
824 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
825 linux_logo.h for logo.
826 Requires CONFIG_VIDEO_LOGO
827 CONFIG_CONSOLE_EXTRA_INFO
828 additional board info beside
830 CONFIG_HIDE_LOGO_VERSION
831 do not display bootloader
834 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
835 a limited number of ANSI escape sequences (cursor control,
836 erase functions and limited graphics rendition control).
838 When CONFIG_CFB_CONSOLE is defined, video console is
839 default i/o. Serial console can be forced with
840 environment 'console=serial'.
842 When CONFIG_SILENT_CONSOLE is defined, all console
843 messages (by U-Boot and Linux!) can be silenced with
844 the "silent" environment variable. See
845 doc/README.silent for more information.
847 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
849 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
853 CONFIG_BAUDRATE - in bps
854 Select one of the baudrates listed in
855 CONFIG_SYS_BAUDRATE_TABLE, see below.
856 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
858 - Console Rx buffer length
859 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
860 the maximum receive buffer length for the SMC.
861 This option is actual only for 82xx and 8xx possible.
862 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
863 must be defined, to setup the maximum idle timeout for
866 - Pre-Console Buffer:
867 Prior to the console being initialised (i.e. serial UART
868 initialised etc) all console output is silently discarded.
869 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
870 buffer any console messages prior to the console being
871 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
872 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
873 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
874 bytes are output before the console is initialised, the
875 earlier bytes are discarded.
877 Note that when printing the buffer a copy is made on the
878 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
880 'Sane' compilers will generate smaller code if
881 CONFIG_PRE_CON_BUF_SZ is a power of 2
885 Only needed when CONFIG_BOOTDELAY is enabled;
886 define a command string that is automatically executed
887 when no character is read on the console interface
888 within "Boot Delay" after reset.
891 This can be used to pass arguments to the bootm
892 command. The value of CONFIG_BOOTARGS goes into the
893 environment value "bootargs".
895 CONFIG_RAMBOOT and CONFIG_NFSBOOT
896 The value of these goes into the environment as
897 "ramboot" and "nfsboot" respectively, and can be used
898 as a convenience, when switching between booting from
902 CONFIG_BOOTCOUNT_LIMIT
903 Implements a mechanism for detecting a repeating reboot
905 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
908 If no softreset save registers are found on the hardware
909 "bootcount" is stored in the environment. To prevent a
910 saveenv on all reboots, the environment variable
911 "upgrade_available" is used. If "upgrade_available" is
912 0, "bootcount" is always 0, if "upgrade_available" is
913 1 "bootcount" is incremented in the environment.
914 So the Userspace Applikation must set the "upgrade_available"
915 and "bootcount" variable to 0, if a boot was successfully.
920 When this option is #defined, the existence of the
921 environment variable "preboot" will be checked
922 immediately before starting the CONFIG_BOOTDELAY
923 countdown and/or running the auto-boot command resp.
924 entering interactive mode.
926 This feature is especially useful when "preboot" is
927 automatically generated or modified. For an example
928 see the LWMON board specific code: here "preboot" is
929 modified when the user holds down a certain
930 combination of keys on the (special) keyboard when
933 - Serial Download Echo Mode:
935 If defined to 1, all characters received during a
936 serial download (using the "loads" command) are
937 echoed back. This might be needed by some terminal
938 emulations (like "cu"), but may as well just take
939 time on others. This setting #define's the initial
940 value of the "loads_echo" environment variable.
942 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
944 Select one of the baudrates listed in
945 CONFIG_SYS_BAUDRATE_TABLE, see below.
948 Monitor commands can be included or excluded
949 from the build by using the #include files
950 <config_cmd_all.h> and #undef'ing unwanted
951 commands, or adding #define's for wanted commands.
953 The default command configuration includes all commands
954 except those marked below with a "*".
956 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
957 CONFIG_CMD_ASKENV * ask for env variable
958 CONFIG_CMD_BDI bdinfo
959 CONFIG_CMD_BEDBUG * Include BedBug Debugger
960 CONFIG_CMD_BMP * BMP support
961 CONFIG_CMD_BSP * Board specific commands
962 CONFIG_CMD_BOOTD bootd
963 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
964 CONFIG_CMD_CACHE * icache, dcache
965 CONFIG_CMD_CLK * clock command support
966 CONFIG_CMD_CONSOLE coninfo
967 CONFIG_CMD_CRC32 * crc32
968 CONFIG_CMD_DATE * support for RTC, date/time...
969 CONFIG_CMD_DHCP * DHCP support
970 CONFIG_CMD_DIAG * Diagnostics
971 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
972 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
973 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
974 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
975 CONFIG_CMD_DTT * Digital Therm and Thermostat
976 CONFIG_CMD_ECHO echo arguments
977 CONFIG_CMD_EDITENV edit env variable
978 CONFIG_CMD_EEPROM * EEPROM read/write support
979 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
980 CONFIG_CMD_ELF * bootelf, bootvx
981 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
982 CONFIG_CMD_ENV_FLAGS * display details about env flags
983 CONFIG_CMD_ENV_EXISTS * check existence of env variable
984 CONFIG_CMD_EXPORTENV * export the environment
985 CONFIG_CMD_EXT2 * ext2 command support
986 CONFIG_CMD_EXT4 * ext4 command support
987 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
988 that work for multiple fs types
989 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
990 CONFIG_CMD_SAVEENV saveenv
991 CONFIG_CMD_FDC * Floppy Disk Support
992 CONFIG_CMD_FAT * FAT command support
993 CONFIG_CMD_FLASH flinfo, erase, protect
994 CONFIG_CMD_FPGA FPGA device initialization support
995 CONFIG_CMD_FUSE * Device fuse support
996 CONFIG_CMD_GETTIME * Get time since boot
997 CONFIG_CMD_GO * the 'go' command (exec code)
998 CONFIG_CMD_GREPENV * search environment
999 CONFIG_CMD_HASH * calculate hash / digest
1000 CONFIG_CMD_I2C * I2C serial bus support
1001 CONFIG_CMD_IDE * IDE harddisk support
1002 CONFIG_CMD_IMI iminfo
1003 CONFIG_CMD_IMLS List all images found in NOR flash
1004 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1005 CONFIG_CMD_IMMAP * IMMR dump support
1006 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1007 CONFIG_CMD_IMPORTENV * import an environment
1008 CONFIG_CMD_INI * import data from an ini file into the env
1009 CONFIG_CMD_IRQ * irqinfo
1010 CONFIG_CMD_ITEST Integer/string test of 2 values
1011 CONFIG_CMD_JFFS2 * JFFS2 Support
1012 CONFIG_CMD_KGDB * kgdb
1013 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1014 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1016 CONFIG_CMD_LOADB loadb
1017 CONFIG_CMD_LOADS loads
1018 CONFIG_CMD_MD5SUM * print md5 message digest
1019 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1020 CONFIG_CMD_MEMINFO * Display detailed memory information
1021 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1023 CONFIG_CMD_MEMTEST * mtest
1024 CONFIG_CMD_MISC Misc functions like sleep etc
1025 CONFIG_CMD_MMC * MMC memory mapped support
1026 CONFIG_CMD_MII * MII utility commands
1027 CONFIG_CMD_MTDPARTS * MTD partition support
1028 CONFIG_CMD_NAND * NAND support
1029 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1030 CONFIG_CMD_NFS NFS support
1031 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1032 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1033 CONFIG_CMD_PCI * pciinfo
1034 CONFIG_CMD_PCMCIA * PCMCIA support
1035 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1037 CONFIG_CMD_PORTIO * Port I/O
1038 CONFIG_CMD_READ * Read raw data from partition
1039 CONFIG_CMD_REGINFO * Register dump
1040 CONFIG_CMD_RUN run command in env variable
1041 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1042 CONFIG_CMD_SAVES * save S record dump
1043 CONFIG_SCSI * SCSI Support
1044 CONFIG_CMD_SDRAM * print SDRAM configuration information
1045 (requires CONFIG_CMD_I2C)
1046 CONFIG_CMD_SETGETDCR Support for DCR Register access
1048 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1049 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1050 (requires CONFIG_CMD_MEMORY)
1051 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1052 CONFIG_CMD_SOURCE "source" command Support
1053 CONFIG_CMD_SPI * SPI serial bus support
1054 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1055 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1056 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1057 CONFIG_CMD_TIMER * access to the system tick timer
1058 CONFIG_CMD_USB * USB support
1059 CONFIG_CMD_CDP * Cisco Discover Protocol support
1060 CONFIG_CMD_MFSL * Microblaze FSL support
1061 CONFIG_CMD_XIMG Load part of Multi Image
1062 CONFIG_CMD_UUID * Generate random UUID or GUID string
1064 EXAMPLE: If you want all functions except of network
1065 support you can write:
1067 #include "config_cmd_all.h"
1068 #undef CONFIG_CMD_NET
1071 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1073 Note: Don't enable the "icache" and "dcache" commands
1074 (configuration option CONFIG_CMD_CACHE) unless you know
1075 what you (and your U-Boot users) are doing. Data
1076 cache cannot be enabled on systems like the 8xx or
1077 8260 (where accesses to the IMMR region must be
1078 uncached), and it cannot be disabled on all other
1079 systems where we (mis-) use the data cache to hold an
1080 initial stack and some data.
1083 XXX - this list needs to get updated!
1085 - Removal of commands
1086 If no commands are needed to boot, you can disable
1087 CONFIG_CMDLINE to remove them. In this case, the command line
1088 will not be available, and when U-Boot wants to execute the
1089 boot command (on start-up) it will call board_run_command()
1090 instead. This can reduce image size significantly for very
1091 simple boot procedures.
1093 - Regular expression support:
1095 If this variable is defined, U-Boot is linked against
1096 the SLRE (Super Light Regular Expression) library,
1097 which adds regex support to some commands, as for
1098 example "env grep" and "setexpr".
1102 If this variable is defined, U-Boot will use a device tree
1103 to configure its devices, instead of relying on statically
1104 compiled #defines in the board file. This option is
1105 experimental and only available on a few boards. The device
1106 tree is available in the global data as gd->fdt_blob.
1108 U-Boot needs to get its device tree from somewhere. This can
1109 be done using one of the two options below:
1112 If this variable is defined, U-Boot will embed a device tree
1113 binary in its image. This device tree file should be in the
1114 board directory and called <soc>-<board>.dts. The binary file
1115 is then picked up in board_init_f() and made available through
1116 the global data structure as gd->blob.
1119 If this variable is defined, U-Boot will build a device tree
1120 binary. It will be called u-boot.dtb. Architecture-specific
1121 code will locate it at run-time. Generally this works by:
1123 cat u-boot.bin u-boot.dtb >image.bin
1125 and in fact, U-Boot does this for you, creating a file called
1126 u-boot-dtb.bin which is useful in the common case. You can
1127 still use the individual files if you need something more
1132 If this variable is defined, it enables watchdog
1133 support for the SoC. There must be support in the SoC
1134 specific code for a watchdog. For the 8xx and 8260
1135 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1136 register. When supported for a specific SoC is
1137 available, then no further board specific code should
1138 be needed to use it.
1141 When using a watchdog circuitry external to the used
1142 SoC, then define this variable and provide board
1143 specific code for the "hw_watchdog_reset" function.
1145 CONFIG_AT91_HW_WDT_TIMEOUT
1146 specify the timeout in seconds. default 2 seconds.
1149 CONFIG_VERSION_VARIABLE
1150 If this variable is defined, an environment variable
1151 named "ver" is created by U-Boot showing the U-Boot
1152 version as printed by the "version" command.
1153 Any change to this variable will be reverted at the
1158 When CONFIG_CMD_DATE is selected, the type of the RTC
1159 has to be selected, too. Define exactly one of the
1162 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1163 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1164 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1165 CONFIG_RTC_MC146818 - use MC146818 RTC
1166 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1167 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1168 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1169 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1170 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1171 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1172 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1173 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1174 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1177 Note that if the RTC uses I2C, then the I2C interface
1178 must also be configured. See I2C Support, below.
1181 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1183 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1184 chip-ngpio pairs that tell the PCA953X driver the number of
1185 pins supported by a particular chip.
1187 Note that if the GPIO device uses I2C, then the I2C interface
1188 must also be configured. See I2C Support, below.
1191 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1192 accesses and can checksum them or write a list of them out
1193 to memory. See the 'iotrace' command for details. This is
1194 useful for testing device drivers since it can confirm that
1195 the driver behaves the same way before and after a code
1196 change. Currently this is supported on sandbox and arm. To
1197 add support for your architecture, add '#include <iotrace.h>'
1198 to the bottom of arch/<arch>/include/asm/io.h and test.
1200 Example output from the 'iotrace stats' command is below.
1201 Note that if the trace buffer is exhausted, the checksum will
1202 still continue to operate.
1205 Start: 10000000 (buffer start address)
1206 Size: 00010000 (buffer size)
1207 Offset: 00000120 (current buffer offset)
1208 Output: 10000120 (start + offset)
1209 Count: 00000018 (number of trace records)
1210 CRC32: 9526fb66 (CRC32 of all trace records)
1212 - Timestamp Support:
1214 When CONFIG_TIMESTAMP is selected, the timestamp
1215 (date and time) of an image is printed by image
1216 commands like bootm or iminfo. This option is
1217 automatically enabled when you select CONFIG_CMD_DATE .
1219 - Partition Labels (disklabels) Supported:
1220 Zero or more of the following:
1221 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1222 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1223 Intel architecture, USB sticks, etc.
1224 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1225 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1226 bootloader. Note 2TB partition limit; see
1228 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1230 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1231 CONFIG_SCSI) you must configure support for at
1232 least one non-MTD partition type as well.
1235 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1236 board configurations files but used nowhere!
1238 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1239 be performed by calling the function
1240 ide_set_reset(int reset)
1241 which has to be defined in a board specific file
1246 Set this to enable ATAPI support.
1251 Set this to enable support for disks larger than 137GB
1252 Also look at CONFIG_SYS_64BIT_LBA.
1253 Whithout these , LBA48 support uses 32bit variables and will 'only'
1254 support disks up to 2.1TB.
1256 CONFIG_SYS_64BIT_LBA:
1257 When enabled, makes the IDE subsystem use 64bit sector addresses.
1261 At the moment only there is only support for the
1262 SYM53C8XX SCSI controller; define
1263 CONFIG_SCSI_SYM53C8XX to enable it.
1265 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1266 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1267 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1268 maximum numbers of LUNs, SCSI ID's and target
1270 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1272 The environment variable 'scsidevs' is set to the number of
1273 SCSI devices found during the last scan.
1275 - NETWORK Support (PCI):
1277 Support for Intel 8254x/8257x gigabit chips.
1280 Utility code for direct access to the SPI bus on Intel 8257x.
1281 This does not do anything useful unless you set at least one
1282 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1284 CONFIG_E1000_SPI_GENERIC
1285 Allow generic access to the SPI bus on the Intel 8257x, for
1286 example with the "sspi" command.
1289 Management command for E1000 devices. When used on devices
1290 with SPI support you can reprogram the EEPROM from U-Boot.
1293 Support for Intel 82557/82559/82559ER chips.
1294 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1295 write routine for first time initialisation.
1298 Support for Digital 2114x chips.
1299 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1300 modem chip initialisation (KS8761/QS6611).
1303 Support for National dp83815 chips.
1306 Support for National dp8382[01] gigabit chips.
1308 - NETWORK Support (other):
1310 CONFIG_DRIVER_AT91EMAC
1311 Support for AT91RM9200 EMAC.
1314 Define this to use reduced MII inteface
1316 CONFIG_DRIVER_AT91EMAC_QUIET
1317 If this defined, the driver is quiet.
1318 The driver doen't show link status messages.
1320 CONFIG_CALXEDA_XGMAC
1321 Support for the Calxeda XGMAC device
1324 Support for SMSC's LAN91C96 chips.
1326 CONFIG_LAN91C96_BASE
1327 Define this to hold the physical address
1328 of the LAN91C96's I/O space
1330 CONFIG_LAN91C96_USE_32_BIT
1331 Define this to enable 32 bit addressing
1334 Support for SMSC's LAN91C111 chip
1336 CONFIG_SMC91111_BASE
1337 Define this to hold the physical address
1338 of the device (I/O space)
1340 CONFIG_SMC_USE_32_BIT
1341 Define this if data bus is 32 bits
1343 CONFIG_SMC_USE_IOFUNCS
1344 Define this to use i/o functions instead of macros
1345 (some hardware wont work with macros)
1347 CONFIG_DRIVER_TI_EMAC
1348 Support for davinci emac
1350 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1351 Define this if you have more then 3 PHYs.
1354 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1356 CONFIG_FTGMAC100_EGIGA
1357 Define this to use GE link update with gigabit PHY.
1358 Define this if FTGMAC100 is connected to gigabit PHY.
1359 If your system has 10/100 PHY only, it might not occur
1360 wrong behavior. Because PHY usually return timeout or
1361 useless data when polling gigabit status and gigabit
1362 control registers. This behavior won't affect the
1363 correctnessof 10/100 link speed update.
1366 Support for SMSC's LAN911x and LAN921x chips
1369 Define this to hold the physical address
1370 of the device (I/O space)
1372 CONFIG_SMC911X_32_BIT
1373 Define this if data bus is 32 bits
1375 CONFIG_SMC911X_16_BIT
1376 Define this if data bus is 16 bits. If your processor
1377 automatically converts one 32 bit word to two 16 bit
1378 words you may also try CONFIG_SMC911X_32_BIT.
1381 Support for Renesas on-chip Ethernet controller
1383 CONFIG_SH_ETHER_USE_PORT
1384 Define the number of ports to be used
1386 CONFIG_SH_ETHER_PHY_ADDR
1387 Define the ETH PHY's address
1389 CONFIG_SH_ETHER_CACHE_WRITEBACK
1390 If this option is set, the driver enables cache flush.
1394 Support for PWM modul on the imx6.
1398 Support TPM devices.
1400 CONFIG_TPM_TIS_INFINEON
1401 Support for Infineon i2c bus TPM devices. Only one device
1402 per system is supported at this time.
1404 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1405 Define the burst count bytes upper limit
1408 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1410 CONFIG_TPM_ST33ZP24_I2C
1411 Support for STMicroelectronics ST33ZP24 I2C devices.
1412 Requires TPM_ST33ZP24 and I2C.
1414 CONFIG_TPM_ST33ZP24_SPI
1415 Support for STMicroelectronics ST33ZP24 SPI devices.
1416 Requires TPM_ST33ZP24 and SPI.
1418 CONFIG_TPM_ATMEL_TWI
1419 Support for Atmel TWI TPM device. Requires I2C support.
1422 Support for generic parallel port TPM devices. Only one device
1423 per system is supported at this time.
1425 CONFIG_TPM_TIS_BASE_ADDRESS
1426 Base address where the generic TPM device is mapped
1427 to. Contemporary x86 systems usually map it at
1431 Add tpm monitor functions.
1432 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1433 provides monitor access to authorized functions.
1436 Define this to enable the TPM support library which provides
1437 functional interfaces to some TPM commands.
1438 Requires support for a TPM device.
1440 CONFIG_TPM_AUTH_SESSIONS
1441 Define this to enable authorized functions in the TPM library.
1442 Requires CONFIG_TPM and CONFIG_SHA1.
1445 At the moment only the UHCI host controller is
1446 supported (PIP405, MIP405, MPC5200); define
1447 CONFIG_USB_UHCI to enable it.
1448 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1449 and define CONFIG_USB_STORAGE to enable the USB
1452 Supported are USB Keyboards and USB Floppy drives
1454 MPC5200 USB requires additional defines:
1456 for 528 MHz Clock: 0x0001bbbb
1460 for differential drivers: 0x00001000
1461 for single ended drivers: 0x00005000
1462 for differential drivers on PSC3: 0x00000100
1463 for single ended drivers on PSC3: 0x00004100
1464 CONFIG_SYS_USB_EVENT_POLL
1465 May be defined to allow interrupt polling
1466 instead of using asynchronous interrupts
1468 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1469 txfilltuning field in the EHCI controller on reset.
1471 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1472 HW module registers.
1475 Define the below if you wish to use the USB console.
1476 Once firmware is rebuilt from a serial console issue the
1477 command "setenv stdin usbtty; setenv stdout usbtty" and
1478 attach your USB cable. The Unix command "dmesg" should print
1479 it has found a new device. The environment variable usbtty
1480 can be set to gserial or cdc_acm to enable your device to
1481 appear to a USB host as a Linux gserial device or a
1482 Common Device Class Abstract Control Model serial device.
1483 If you select usbtty = gserial you should be able to enumerate
1485 # modprobe usbserial vendor=0xVendorID product=0xProductID
1486 else if using cdc_acm, simply setting the environment
1487 variable usbtty to be cdc_acm should suffice. The following
1488 might be defined in YourBoardName.h
1491 Define this to build a UDC device
1494 Define this to have a tty type of device available to
1495 talk to the UDC device
1498 Define this to enable the high speed support for usb
1499 device and usbtty. If this feature is enabled, a routine
1500 int is_usbd_high_speed(void)
1501 also needs to be defined by the driver to dynamically poll
1502 whether the enumeration has succeded at high speed or full
1505 CONFIG_SYS_CONSOLE_IS_IN_ENV
1506 Define this if you want stdin, stdout &/or stderr to
1510 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1511 Derive USB clock from external clock "blah"
1512 - CONFIG_SYS_USB_EXTC_CLK 0x02
1514 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1515 Derive USB clock from brgclk
1516 - CONFIG_SYS_USB_BRG_CLK 0x04
1518 If you have a USB-IF assigned VendorID then you may wish to
1519 define your own vendor specific values either in BoardName.h
1520 or directly in usbd_vendor_info.h. If you don't define
1521 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1522 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1523 should pretend to be a Linux device to it's target host.
1525 CONFIG_USBD_MANUFACTURER
1526 Define this string as the name of your company for
1527 - CONFIG_USBD_MANUFACTURER "my company"
1529 CONFIG_USBD_PRODUCT_NAME
1530 Define this string as the name of your product
1531 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1533 CONFIG_USBD_VENDORID
1534 Define this as your assigned Vendor ID from the USB
1535 Implementors Forum. This *must* be a genuine Vendor ID
1536 to avoid polluting the USB namespace.
1537 - CONFIG_USBD_VENDORID 0xFFFF
1539 CONFIG_USBD_PRODUCTID
1540 Define this as the unique Product ID
1542 - CONFIG_USBD_PRODUCTID 0xFFFF
1544 - ULPI Layer Support:
1545 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1546 the generic ULPI layer. The generic layer accesses the ULPI PHY
1547 via the platform viewport, so you need both the genric layer and
1548 the viewport enabled. Currently only Chipidea/ARC based
1549 viewport is supported.
1550 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1551 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1552 If your ULPI phy needs a different reference clock than the
1553 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1554 the appropriate value in Hz.
1557 The MMC controller on the Intel PXA is supported. To
1558 enable this define CONFIG_MMC. The MMC can be
1559 accessed from the boot prompt by mapping the device
1560 to physical memory similar to flash. Command line is
1561 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1562 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1565 Support for Renesas on-chip MMCIF controller
1567 CONFIG_SH_MMCIF_ADDR
1568 Define the base address of MMCIF registers
1571 Define the clock frequency for MMCIF
1574 Enable the generic MMC driver
1576 CONFIG_SUPPORT_EMMC_BOOT
1577 Enable some additional features of the eMMC boot partitions.
1579 CONFIG_SUPPORT_EMMC_RPMB
1580 Enable the commands for reading, writing and programming the
1581 key for the Replay Protection Memory Block partition in eMMC.
1583 - USB Device Firmware Update (DFU) class support:
1584 CONFIG_USB_FUNCTION_DFU
1585 This enables the USB portion of the DFU USB class
1588 This enables the command "dfu" which is used to have
1589 U-Boot create a DFU class device via USB. This command
1590 requires that the "dfu_alt_info" environment variable be
1591 set and define the alt settings to expose to the host.
1594 This enables support for exposing (e)MMC devices via DFU.
1597 This enables support for exposing NAND devices via DFU.
1600 This enables support for exposing RAM via DFU.
1601 Note: DFU spec refer to non-volatile memory usage, but
1602 allow usages beyond the scope of spec - here RAM usage,
1603 one that would help mostly the developer.
1605 CONFIG_SYS_DFU_DATA_BUF_SIZE
1606 Dfu transfer uses a buffer before writing data to the
1607 raw storage device. Make the size (in bytes) of this buffer
1608 configurable. The size of this buffer is also configurable
1609 through the "dfu_bufsiz" environment variable.
1611 CONFIG_SYS_DFU_MAX_FILE_SIZE
1612 When updating files rather than the raw storage device,
1613 we use a static buffer to copy the file into and then write
1614 the buffer once we've been given the whole file. Define
1615 this to the maximum filesize (in bytes) for the buffer.
1616 Default is 4 MiB if undefined.
1618 DFU_DEFAULT_POLL_TIMEOUT
1619 Poll timeout [ms], is the timeout a device can send to the
1620 host. The host must wait for this timeout before sending
1621 a subsequent DFU_GET_STATUS request to the device.
1623 DFU_MANIFEST_POLL_TIMEOUT
1624 Poll timeout [ms], which the device sends to the host when
1625 entering dfuMANIFEST state. Host waits this timeout, before
1626 sending again an USB request to the device.
1628 - USB Device Android Fastboot support:
1629 CONFIG_USB_FUNCTION_FASTBOOT
1630 This enables the USB part of the fastboot gadget
1633 This enables the command "fastboot" which enables the Android
1634 fastboot mode for the platform's USB device. Fastboot is a USB
1635 protocol for downloading images, flashing and device control
1636 used on Android devices.
1637 See doc/README.android-fastboot for more information.
1639 CONFIG_ANDROID_BOOT_IMAGE
1640 This enables support for booting images which use the Android
1641 image format header.
1643 CONFIG_FASTBOOT_BUF_ADDR
1644 The fastboot protocol requires a large memory buffer for
1645 downloads. Define this to the starting RAM address to use for
1648 CONFIG_FASTBOOT_BUF_SIZE
1649 The fastboot protocol requires a large memory buffer for
1650 downloads. This buffer should be as large as possible for a
1651 platform. Define this to the size available RAM for fastboot.
1653 CONFIG_FASTBOOT_FLASH
1654 The fastboot protocol includes a "flash" command for writing
1655 the downloaded image to a non-volatile storage device. Define
1656 this to enable the "fastboot flash" command.
1658 CONFIG_FASTBOOT_FLASH_MMC_DEV
1659 The fastboot "flash" command requires additional information
1660 regarding the non-volatile storage device. Define this to
1661 the eMMC device that fastboot should use to store the image.
1663 CONFIG_FASTBOOT_GPT_NAME
1664 The fastboot "flash" command supports writing the downloaded
1665 image to the Protective MBR and the Primary GUID Partition
1666 Table. (Additionally, this downloaded image is post-processed
1667 to generate and write the Backup GUID Partition Table.)
1668 This occurs when the specified "partition name" on the
1669 "fastboot flash" command line matches this value.
1670 The default is "gpt" if undefined.
1672 CONFIG_FASTBOOT_MBR_NAME
1673 The fastboot "flash" command supports writing the downloaded
1675 This occurs when the "partition name" specified on the
1676 "fastboot flash" command line matches this value.
1677 If not defined the default value "mbr" is used.
1679 - Journaling Flash filesystem support:
1680 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1681 CONFIG_JFFS2_NAND_DEV
1682 Define these for a default partition on a NAND device
1684 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1685 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1686 Define these for a default partition on a NOR device
1688 CONFIG_SYS_JFFS_CUSTOM_PART
1689 Define this to create an own partition. You have to provide a
1690 function struct part_info* jffs2_part_info(int part_num)
1692 If you define only one JFFS2 partition you may also want to
1693 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1694 to disable the command chpart. This is the default when you
1695 have not defined a custom partition
1697 - FAT(File Allocation Table) filesystem write function support:
1700 Define this to enable support for saving memory data as a
1701 file in FAT formatted partition.
1703 This will also enable the command "fatwrite" enabling the
1704 user to write files to FAT.
1706 CBFS (Coreboot Filesystem) support
1709 Define this to enable support for reading from a Coreboot
1710 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1713 - FAT(File Allocation Table) filesystem cluster size:
1714 CONFIG_FS_FAT_MAX_CLUSTSIZE
1716 Define the max cluster size for fat operations else
1717 a default value of 65536 will be defined.
1720 See Kconfig help for available keyboard drivers.
1724 Define this to enable a custom keyboard support.
1725 This simply calls drv_keyboard_init() which must be
1726 defined in your board-specific files. This option is deprecated
1727 and is only used by novena. For new boards, use driver model
1733 Define this to enable video support (for output to
1736 CONFIG_VIDEO_CT69000
1738 Enable Chips & Technologies 69000 Video chip
1740 CONFIG_VIDEO_SMI_LYNXEM
1741 Enable Silicon Motion SMI 712/710/810 Video chip. The
1742 video output is selected via environment 'videoout'
1743 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1746 For the CT69000 and SMI_LYNXEM drivers, videomode is
1747 selected via environment 'videomode'. Two different ways
1749 - "videomode=num" 'num' is a standard LiLo mode numbers.
1750 Following standard modes are supported (* is default):
1752 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1753 -------------+---------------------------------------------
1754 8 bits | 0x301* 0x303 0x305 0x161 0x307
1755 15 bits | 0x310 0x313 0x316 0x162 0x319
1756 16 bits | 0x311 0x314 0x317 0x163 0x31A
1757 24 bits | 0x312 0x315 0x318 ? 0x31B
1758 -------------+---------------------------------------------
1759 (i.e. setenv videomode 317; saveenv; reset;)
1761 - "videomode=bootargs" all the video parameters are parsed
1762 from the bootargs. (See drivers/video/videomodes.c)
1765 CONFIG_VIDEO_SED13806
1766 Enable Epson SED13806 driver. This driver supports 8bpp
1767 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1768 or CONFIG_VIDEO_SED13806_16BPP
1771 Enable the Freescale DIU video driver. Reference boards for
1772 SOCs that have a DIU should define this macro to enable DIU
1773 support, and should also define these other macros:
1779 CONFIG_VIDEO_SW_CURSOR
1780 CONFIG_VGA_AS_SINGLE_DEVICE
1782 CONFIG_VIDEO_BMP_LOGO
1784 The DIU driver will look for the 'video-mode' environment
1785 variable, and if defined, enable the DIU as a console during
1786 boot. See the documentation file doc/README.video for a
1787 description of this variable.
1789 - LCD Support: CONFIG_LCD
1791 Define this to enable LCD support (for output to LCD
1792 display); also select one of the supported displays
1793 by defining one of these:
1797 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1799 CONFIG_NEC_NL6448AC33:
1801 NEC NL6448AC33-18. Active, color, single scan.
1803 CONFIG_NEC_NL6448BC20
1805 NEC NL6448BC20-08. 6.5", 640x480.
1806 Active, color, single scan.
1808 CONFIG_NEC_NL6448BC33_54
1810 NEC NL6448BC33-54. 10.4", 640x480.
1811 Active, color, single scan.
1815 Sharp 320x240. Active, color, single scan.
1816 It isn't 16x9, and I am not sure what it is.
1818 CONFIG_SHARP_LQ64D341
1820 Sharp LQ64D341 display, 640x480.
1821 Active, color, single scan.
1825 HLD1045 display, 640x480.
1826 Active, color, single scan.
1830 Optrex CBL50840-2 NF-FW 99 22 M5
1832 Hitachi LMG6912RPFC-00T
1836 320x240. Black & white.
1838 Normally display is black on white background; define
1839 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1841 CONFIG_LCD_ALIGNMENT
1843 Normally the LCD is page-aligned (typically 4KB). If this is
1844 defined then the LCD will be aligned to this value instead.
1845 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1846 here, since it is cheaper to change data cache settings on
1847 a per-section basis.
1849 CONFIG_CONSOLE_SCROLL_LINES
1851 When the console need to be scrolled, this is the number of
1852 lines to scroll by. It defaults to 1. Increasing this makes
1853 the console jump but can help speed up operation when scrolling
1858 Sometimes, for example if the display is mounted in portrait
1859 mode or even if it's mounted landscape but rotated by 180degree,
1860 we need to rotate our content of the display relative to the
1861 framebuffer, so that user can read the messages which are
1863 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1864 initialized with a given rotation from "vl_rot" out of
1865 "vidinfo_t" which is provided by the board specific code.
1866 The value for vl_rot is coded as following (matching to
1867 fbcon=rotate:<n> linux-kernel commandline):
1868 0 = no rotation respectively 0 degree
1869 1 = 90 degree rotation
1870 2 = 180 degree rotation
1871 3 = 270 degree rotation
1873 If CONFIG_LCD_ROTATION is not defined, the console will be
1874 initialized with 0degree rotation.
1878 Support drawing of RLE8-compressed bitmaps on the LCD.
1882 Enables an 'i2c edid' command which can read EDID
1883 information over I2C from an attached LCD display.
1885 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1887 If this option is set, the environment is checked for
1888 a variable "splashimage". If found, the usual display
1889 of logo, copyright and system information on the LCD
1890 is suppressed and the BMP image at the address
1891 specified in "splashimage" is loaded instead. The
1892 console is redirected to the "nulldev", too. This
1893 allows for a "silent" boot where a splash screen is
1894 loaded very quickly after power-on.
1896 CONFIG_SPLASHIMAGE_GUARD
1898 If this option is set, then U-Boot will prevent the environment
1899 variable "splashimage" from being set to a problematic address
1900 (see doc/README.displaying-bmps).
1901 This option is useful for targets where, due to alignment
1902 restrictions, an improperly aligned BMP image will cause a data
1903 abort. If you think you will not have problems with unaligned
1904 accesses (for example because your toolchain prevents them)
1905 there is no need to set this option.
1907 CONFIG_SPLASH_SCREEN_ALIGN
1909 If this option is set the splash image can be freely positioned
1910 on the screen. Environment variable "splashpos" specifies the
1911 position as "x,y". If a positive number is given it is used as
1912 number of pixel from left/top. If a negative number is given it
1913 is used as number of pixel from right/bottom. You can also
1914 specify 'm' for centering the image.
1917 setenv splashpos m,m
1918 => image at center of screen
1920 setenv splashpos 30,20
1921 => image at x = 30 and y = 20
1923 setenv splashpos -10,m
1924 => vertically centered image
1925 at x = dspWidth - bmpWidth - 9
1927 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1929 If this option is set, additionally to standard BMP
1930 images, gzipped BMP images can be displayed via the
1931 splashscreen support or the bmp command.
1933 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1935 If this option is set, 8-bit RLE compressed BMP images
1936 can be displayed via the splashscreen support or the
1939 - Do compressing for memory range:
1942 If this option is set, it would use zlib deflate method
1943 to compress the specified memory at its best effort.
1945 - Compression support:
1948 Enabled by default to support gzip compressed images.
1952 If this option is set, support for bzip2 compressed
1953 images is included. If not, only uncompressed and gzip
1954 compressed images are supported.
1956 NOTE: the bzip2 algorithm requires a lot of RAM, so
1957 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1962 If this option is set, support for lzma compressed
1965 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1966 requires an amount of dynamic memory that is given by the
1969 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1971 Where lc and lp stand for, respectively, Literal context bits
1972 and Literal pos bits.
1974 This value is upper-bounded by 14MB in the worst case. Anyway,
1975 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1976 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1977 a very small buffer.
1979 Use the lzmainfo tool to determinate the lc and lp values and
1980 then calculate the amount of needed dynamic memory (ensuring
1981 the appropriate CONFIG_SYS_MALLOC_LEN value).
1985 If this option is set, support for LZO compressed images
1991 The address of PHY on MII bus.
1993 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1995 The clock frequency of the MII bus
1999 If this option is set, support for speed/duplex
2000 detection of gigabit PHY is included.
2002 CONFIG_PHY_RESET_DELAY
2004 Some PHY like Intel LXT971A need extra delay after
2005 reset before any MII register access is possible.
2006 For such PHY, set this option to the usec delay
2007 required. (minimum 300usec for LXT971A)
2009 CONFIG_PHY_CMD_DELAY (ppc4xx)
2011 Some PHY like Intel LXT971A need extra delay after
2012 command issued before MII status register can be read
2017 Define a default value for the IP address to use for
2018 the default Ethernet interface, in case this is not
2019 determined through e.g. bootp.
2020 (Environment variable "ipaddr")
2022 - Server IP address:
2025 Defines a default value for the IP address of a TFTP
2026 server to contact when using the "tftboot" command.
2027 (Environment variable "serverip")
2029 CONFIG_KEEP_SERVERADDR
2031 Keeps the server's MAC address, in the env 'serveraddr'
2032 for passing to bootargs (like Linux's netconsole option)
2034 - Gateway IP address:
2037 Defines a default value for the IP address of the
2038 default router where packets to other networks are
2040 (Environment variable "gatewayip")
2045 Defines a default value for the subnet mask (or
2046 routing prefix) which is used to determine if an IP
2047 address belongs to the local subnet or needs to be
2048 forwarded through a router.
2049 (Environment variable "netmask")
2051 - Multicast TFTP Mode:
2054 Defines whether you want to support multicast TFTP as per
2055 rfc-2090; for example to work with atftp. Lets lots of targets
2056 tftp down the same boot image concurrently. Note: the Ethernet
2057 driver in use must provide a function: mcast() to join/leave a
2060 - BOOTP Recovery Mode:
2061 CONFIG_BOOTP_RANDOM_DELAY
2063 If you have many targets in a network that try to
2064 boot using BOOTP, you may want to avoid that all
2065 systems send out BOOTP requests at precisely the same
2066 moment (which would happen for instance at recovery
2067 from a power failure, when all systems will try to
2068 boot, thus flooding the BOOTP server. Defining
2069 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2070 inserted before sending out BOOTP requests. The
2071 following delays are inserted then:
2073 1st BOOTP request: delay 0 ... 1 sec
2074 2nd BOOTP request: delay 0 ... 2 sec
2075 3rd BOOTP request: delay 0 ... 4 sec
2077 BOOTP requests: delay 0 ... 8 sec
2079 CONFIG_BOOTP_ID_CACHE_SIZE
2081 BOOTP packets are uniquely identified using a 32-bit ID. The
2082 server will copy the ID from client requests to responses and
2083 U-Boot will use this to determine if it is the destination of
2084 an incoming response. Some servers will check that addresses
2085 aren't in use before handing them out (usually using an ARP
2086 ping) and therefore take up to a few hundred milliseconds to
2087 respond. Network congestion may also influence the time it
2088 takes for a response to make it back to the client. If that
2089 time is too long, U-Boot will retransmit requests. In order
2090 to allow earlier responses to still be accepted after these
2091 retransmissions, U-Boot's BOOTP client keeps a small cache of
2092 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2093 cache. The default is to keep IDs for up to four outstanding
2094 requests. Increasing this will allow U-Boot to accept offers
2095 from a BOOTP client in networks with unusually high latency.
2097 - DHCP Advanced Options:
2098 You can fine tune the DHCP functionality by defining
2099 CONFIG_BOOTP_* symbols:
2101 CONFIG_BOOTP_SUBNETMASK
2102 CONFIG_BOOTP_GATEWAY
2103 CONFIG_BOOTP_HOSTNAME
2104 CONFIG_BOOTP_NISDOMAIN
2105 CONFIG_BOOTP_BOOTPATH
2106 CONFIG_BOOTP_BOOTFILESIZE
2109 CONFIG_BOOTP_SEND_HOSTNAME
2110 CONFIG_BOOTP_NTPSERVER
2111 CONFIG_BOOTP_TIMEOFFSET
2112 CONFIG_BOOTP_VENDOREX
2113 CONFIG_BOOTP_MAY_FAIL
2115 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2116 environment variable, not the BOOTP server.
2118 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2119 after the configured retry count, the call will fail
2120 instead of starting over. This can be used to fail over
2121 to Link-local IP address configuration if the DHCP server
2124 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2125 serverip from a DHCP server, it is possible that more
2126 than one DNS serverip is offered to the client.
2127 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2128 serverip will be stored in the additional environment
2129 variable "dnsip2". The first DNS serverip is always
2130 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2133 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2134 to do a dynamic update of a DNS server. To do this, they
2135 need the hostname of the DHCP requester.
2136 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2137 of the "hostname" environment variable is passed as
2138 option 12 to the DHCP server.
2140 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2142 A 32bit value in microseconds for a delay between
2143 receiving a "DHCP Offer" and sending the "DHCP Request".
2144 This fixes a problem with certain DHCP servers that don't
2145 respond 100% of the time to a "DHCP request". E.g. On an
2146 AT91RM9200 processor running at 180MHz, this delay needed
2147 to be *at least* 15,000 usec before a Windows Server 2003
2148 DHCP server would reply 100% of the time. I recommend at
2149 least 50,000 usec to be safe. The alternative is to hope
2150 that one of the retries will be successful but note that
2151 the DHCP timeout and retry process takes a longer than
2154 - Link-local IP address negotiation:
2155 Negotiate with other link-local clients on the local network
2156 for an address that doesn't require explicit configuration.
2157 This is especially useful if a DHCP server cannot be guaranteed
2158 to exist in all environments that the device must operate.
2160 See doc/README.link-local for more information.
2163 CONFIG_CDP_DEVICE_ID
2165 The device id used in CDP trigger frames.
2167 CONFIG_CDP_DEVICE_ID_PREFIX
2169 A two character string which is prefixed to the MAC address
2174 A printf format string which contains the ascii name of
2175 the port. Normally is set to "eth%d" which sets
2176 eth0 for the first Ethernet, eth1 for the second etc.
2178 CONFIG_CDP_CAPABILITIES
2180 A 32bit integer which indicates the device capabilities;
2181 0x00000010 for a normal host which does not forwards.
2185 An ascii string containing the version of the software.
2189 An ascii string containing the name of the platform.
2193 A 32bit integer sent on the trigger.
2195 CONFIG_CDP_POWER_CONSUMPTION
2197 A 16bit integer containing the power consumption of the
2198 device in .1 of milliwatts.
2200 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2202 A byte containing the id of the VLAN.
2204 - Status LED: CONFIG_STATUS_LED
2206 Several configurations allow to display the current
2207 status using a LED. For instance, the LED will blink
2208 fast while running U-Boot code, stop blinking as
2209 soon as a reply to a BOOTP request was received, and
2210 start blinking slow once the Linux kernel is running
2211 (supported by a status LED driver in the Linux
2212 kernel). Defining CONFIG_STATUS_LED enables this
2218 The status LED can be connected to a GPIO pin.
2219 In such cases, the gpio_led driver can be used as a
2220 status LED backend implementation. Define CONFIG_GPIO_LED
2221 to include the gpio_led driver in the U-Boot binary.
2223 CONFIG_GPIO_LED_INVERTED_TABLE
2224 Some GPIO connected LEDs may have inverted polarity in which
2225 case the GPIO high value corresponds to LED off state and
2226 GPIO low value corresponds to LED on state.
2227 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2228 with a list of GPIO LEDs that have inverted polarity.
2230 - CAN Support: CONFIG_CAN_DRIVER
2232 Defining CONFIG_CAN_DRIVER enables CAN driver support
2233 on those systems that support this (optional)
2234 feature, like the TQM8xxL modules.
2236 - I2C Support: CONFIG_SYS_I2C
2238 This enable the NEW i2c subsystem, and will allow you to use
2239 i2c commands at the u-boot command line (as long as you set
2240 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2241 based realtime clock chips or other i2c devices. See
2242 common/cmd_i2c.c for a description of the command line
2245 ported i2c driver to the new framework:
2246 - drivers/i2c/soft_i2c.c:
2247 - activate first bus with CONFIG_SYS_I2C_SOFT define
2248 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2249 for defining speed and slave address
2250 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2251 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2252 for defining speed and slave address
2253 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2254 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2255 for defining speed and slave address
2256 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2257 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2258 for defining speed and slave address
2260 - drivers/i2c/fsl_i2c.c:
2261 - activate i2c driver with CONFIG_SYS_I2C_FSL
2262 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2263 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2264 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2266 - If your board supports a second fsl i2c bus, define
2267 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2268 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2269 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2272 - drivers/i2c/tegra_i2c.c:
2273 - activate this driver with CONFIG_SYS_I2C_TEGRA
2274 - This driver adds 4 i2c buses with a fix speed from
2275 100000 and the slave addr 0!
2277 - drivers/i2c/ppc4xx_i2c.c
2278 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2279 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2280 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2282 - drivers/i2c/i2c_mxc.c
2283 - activate this driver with CONFIG_SYS_I2C_MXC
2284 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2285 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2286 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2287 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2288 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2289 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2290 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2291 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2292 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2293 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2294 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2295 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2296 If those defines are not set, default value is 100000
2297 for speed, and 0 for slave.
2299 - drivers/i2c/rcar_i2c.c:
2300 - activate this driver with CONFIG_SYS_I2C_RCAR
2301 - This driver adds 4 i2c buses
2303 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2304 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2305 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2306 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2307 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2308 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2309 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2310 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2311 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2313 - drivers/i2c/sh_i2c.c:
2314 - activate this driver with CONFIG_SYS_I2C_SH
2315 - This driver adds from 2 to 5 i2c buses
2317 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2318 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2319 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2320 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2321 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2322 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2323 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2324 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2325 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2326 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2327 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2328 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2329 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2331 - drivers/i2c/omap24xx_i2c.c
2332 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2333 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2334 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2335 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2336 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2337 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2338 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2339 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2340 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2341 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2342 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2344 - drivers/i2c/zynq_i2c.c
2345 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2346 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2347 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2349 - drivers/i2c/s3c24x0_i2c.c:
2350 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2351 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2352 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2353 with a fix speed from 100000 and the slave addr 0!
2355 - drivers/i2c/ihs_i2c.c
2356 - activate this driver with CONFIG_SYS_I2C_IHS
2357 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2358 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2359 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2360 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2361 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2362 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2363 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2364 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2365 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2366 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2367 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2368 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2369 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2370 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2371 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2372 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2373 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2374 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2375 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2376 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2377 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2381 CONFIG_SYS_NUM_I2C_BUSES
2382 Hold the number of i2c buses you want to use. If you
2383 don't use/have i2c muxes on your i2c bus, this
2384 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2387 CONFIG_SYS_I2C_DIRECT_BUS
2388 define this, if you don't use i2c muxes on your hardware.
2389 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2392 CONFIG_SYS_I2C_MAX_HOPS
2393 define how many muxes are maximal consecutively connected
2394 on one i2c bus. If you not use i2c muxes, omit this
2397 CONFIG_SYS_I2C_BUSES
2398 hold a list of buses you want to use, only used if
2399 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2400 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2401 CONFIG_SYS_NUM_I2C_BUSES = 9:
2403 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2404 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2405 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2406 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2407 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2408 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2409 {1, {I2C_NULL_HOP}}, \
2410 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2411 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2415 bus 0 on adapter 0 without a mux
2416 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2417 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2418 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2419 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2420 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2421 bus 6 on adapter 1 without a mux
2422 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2423 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2425 If you do not have i2c muxes on your board, omit this define.
2427 - Legacy I2C Support: CONFIG_HARD_I2C
2429 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2430 provides the following compelling advantages:
2432 - more than one i2c adapter is usable
2433 - approved multibus support
2434 - better i2c mux support
2436 ** Please consider updating your I2C driver now. **
2438 These enable legacy I2C serial bus commands. Defining
2439 CONFIG_HARD_I2C will include the appropriate I2C driver
2440 for the selected CPU.
2442 This will allow you to use i2c commands at the u-boot
2443 command line (as long as you set CONFIG_CMD_I2C in
2444 CONFIG_COMMANDS) and communicate with i2c based realtime
2445 clock chips. See common/cmd_i2c.c for a description of the
2446 command line interface.
2448 CONFIG_HARD_I2C selects a hardware I2C controller.
2450 There are several other quantities that must also be
2451 defined when you define CONFIG_HARD_I2C.
2453 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2454 to be the frequency (in Hz) at which you wish your i2c bus
2455 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2456 the CPU's i2c node address).
2458 Now, the u-boot i2c code for the mpc8xx
2459 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2460 and so its address should therefore be cleared to 0 (See,
2461 eg, MPC823e User's Manual p.16-473). So, set
2462 CONFIG_SYS_I2C_SLAVE to 0.
2464 CONFIG_SYS_I2C_INIT_MPC5XXX
2466 When a board is reset during an i2c bus transfer
2467 chips might think that the current transfer is still
2468 in progress. Reset the slave devices by sending start
2469 commands until the slave device responds.
2471 That's all that's required for CONFIG_HARD_I2C.
2473 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2474 then the following macros need to be defined (examples are
2475 from include/configs/lwmon.h):
2479 (Optional). Any commands necessary to enable the I2C
2480 controller or configure ports.
2482 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2486 (Only for MPC8260 CPU). The I/O port to use (the code
2487 assumes both bits are on the same port). Valid values
2488 are 0..3 for ports A..D.
2492 The code necessary to make the I2C data line active
2493 (driven). If the data line is open collector, this
2496 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2500 The code necessary to make the I2C data line tri-stated
2501 (inactive). If the data line is open collector, this
2504 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2508 Code that returns true if the I2C data line is high,
2511 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2515 If <bit> is true, sets the I2C data line high. If it
2516 is false, it clears it (low).
2518 eg: #define I2C_SDA(bit) \
2519 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2520 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2524 If <bit> is true, sets the I2C clock line high. If it
2525 is false, it clears it (low).
2527 eg: #define I2C_SCL(bit) \
2528 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2529 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2533 This delay is invoked four times per clock cycle so this
2534 controls the rate of data transfer. The data rate thus
2535 is 1 / (I2C_DELAY * 4). Often defined to be something
2538 #define I2C_DELAY udelay(2)
2540 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2542 If your arch supports the generic GPIO framework (asm/gpio.h),
2543 then you may alternatively define the two GPIOs that are to be
2544 used as SCL / SDA. Any of the previous I2C_xxx macros will
2545 have GPIO-based defaults assigned to them as appropriate.
2547 You should define these to the GPIO value as given directly to
2548 the generic GPIO functions.
2550 CONFIG_SYS_I2C_INIT_BOARD
2552 When a board is reset during an i2c bus transfer
2553 chips might think that the current transfer is still
2554 in progress. On some boards it is possible to access
2555 the i2c SCLK line directly, either by using the
2556 processor pin as a GPIO or by having a second pin
2557 connected to the bus. If this option is defined a
2558 custom i2c_init_board() routine in boards/xxx/board.c
2559 is run early in the boot sequence.
2561 CONFIG_SYS_I2C_BOARD_LATE_INIT
2563 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2564 defined a custom i2c_board_late_init() routine in
2565 boards/xxx/board.c is run AFTER the operations in i2c_init()
2566 is completed. This callpoint can be used to unreset i2c bus
2567 using CPU i2c controller register accesses for CPUs whose i2c
2568 controller provide such a method. It is called at the end of
2569 i2c_init() to allow i2c_init operations to setup the i2c bus
2570 controller on the CPU (e.g. setting bus speed & slave address).
2572 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2574 This option enables configuration of bi_iic_fast[] flags
2575 in u-boot bd_info structure based on u-boot environment
2576 variable "i2cfast". (see also i2cfast)
2578 CONFIG_I2C_MULTI_BUS
2580 This option allows the use of multiple I2C buses, each of which
2581 must have a controller. At any point in time, only one bus is
2582 active. To switch to a different bus, use the 'i2c dev' command.
2583 Note that bus numbering is zero-based.
2585 CONFIG_SYS_I2C_NOPROBES
2587 This option specifies a list of I2C devices that will be skipped
2588 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2589 is set, specify a list of bus-device pairs. Otherwise, specify
2590 a 1D array of device addresses
2593 #undef CONFIG_I2C_MULTI_BUS
2594 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2596 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2598 #define CONFIG_I2C_MULTI_BUS
2599 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2601 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2603 CONFIG_SYS_SPD_BUS_NUM
2605 If defined, then this indicates the I2C bus number for DDR SPD.
2606 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2608 CONFIG_SYS_RTC_BUS_NUM
2610 If defined, then this indicates the I2C bus number for the RTC.
2611 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2613 CONFIG_SYS_DTT_BUS_NUM
2615 If defined, then this indicates the I2C bus number for the DTT.
2616 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2618 CONFIG_SYS_I2C_DTT_ADDR:
2620 If defined, specifies the I2C address of the DTT device.
2621 If not defined, then U-Boot uses predefined value for
2622 specified DTT device.
2624 CONFIG_SOFT_I2C_READ_REPEATED_START
2626 defining this will force the i2c_read() function in
2627 the soft_i2c driver to perform an I2C repeated start
2628 between writing the address pointer and reading the
2629 data. If this define is omitted the default behaviour
2630 of doing a stop-start sequence will be used. Most I2C
2631 devices can use either method, but some require one or
2634 - SPI Support: CONFIG_SPI
2636 Enables SPI driver (so far only tested with
2637 SPI EEPROM, also an instance works with Crystal A/D and
2638 D/As on the SACSng board)
2642 Enables the driver for SPI controller on SuperH. Currently
2643 only SH7757 is supported.
2647 Enables a software (bit-bang) SPI driver rather than
2648 using hardware support. This is a general purpose
2649 driver that only requires three general I/O port pins
2650 (two outputs, one input) to function. If this is
2651 defined, the board configuration must define several
2652 SPI configuration items (port pins to use, etc). For
2653 an example, see include/configs/sacsng.h.
2657 Enables a hardware SPI driver for general-purpose reads
2658 and writes. As with CONFIG_SOFT_SPI, the board configuration
2659 must define a list of chip-select function pointers.
2660 Currently supported on some MPC8xxx processors. For an
2661 example, see include/configs/mpc8349emds.h.
2665 Enables the driver for the SPI controllers on i.MX and MXC
2666 SoCs. Currently i.MX31/35/51 are supported.
2668 CONFIG_SYS_SPI_MXC_WAIT
2669 Timeout for waiting until spi transfer completed.
2670 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2672 - FPGA Support: CONFIG_FPGA
2674 Enables FPGA subsystem.
2676 CONFIG_FPGA_<vendor>
2678 Enables support for specific chip vendors.
2681 CONFIG_FPGA_<family>
2683 Enables support for FPGA family.
2684 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2688 Specify the number of FPGA devices to support.
2690 CONFIG_CMD_FPGA_LOADMK
2692 Enable support for fpga loadmk command
2694 CONFIG_CMD_FPGA_LOADP
2696 Enable support for fpga loadp command - load partial bitstream
2698 CONFIG_CMD_FPGA_LOADBP
2700 Enable support for fpga loadbp command - load partial bitstream
2703 CONFIG_SYS_FPGA_PROG_FEEDBACK
2705 Enable printing of hash marks during FPGA configuration.
2707 CONFIG_SYS_FPGA_CHECK_BUSY
2709 Enable checks on FPGA configuration interface busy
2710 status by the configuration function. This option
2711 will require a board or device specific function to
2716 If defined, a function that provides delays in the FPGA
2717 configuration driver.
2719 CONFIG_SYS_FPGA_CHECK_CTRLC
2720 Allow Control-C to interrupt FPGA configuration
2722 CONFIG_SYS_FPGA_CHECK_ERROR
2724 Check for configuration errors during FPGA bitfile
2725 loading. For example, abort during Virtex II
2726 configuration if the INIT_B line goes low (which
2727 indicated a CRC error).
2729 CONFIG_SYS_FPGA_WAIT_INIT
2731 Maximum time to wait for the INIT_B line to de-assert
2732 after PROB_B has been de-asserted during a Virtex II
2733 FPGA configuration sequence. The default time is 500
2736 CONFIG_SYS_FPGA_WAIT_BUSY
2738 Maximum time to wait for BUSY to de-assert during
2739 Virtex II FPGA configuration. The default is 5 ms.
2741 CONFIG_SYS_FPGA_WAIT_CONFIG
2743 Time to wait after FPGA configuration. The default is
2746 - Configuration Management:
2749 Some SoCs need special image types (e.g. U-Boot binary
2750 with a special header) as build targets. By defining
2751 CONFIG_BUILD_TARGET in the SoC / board header, this
2752 special image will be automatically built upon calling
2757 If defined, this string will be added to the U-Boot
2758 version information (U_BOOT_VERSION)
2760 - Vendor Parameter Protection:
2762 U-Boot considers the values of the environment
2763 variables "serial#" (Board Serial Number) and
2764 "ethaddr" (Ethernet Address) to be parameters that
2765 are set once by the board vendor / manufacturer, and
2766 protects these variables from casual modification by
2767 the user. Once set, these variables are read-only,
2768 and write or delete attempts are rejected. You can
2769 change this behaviour:
2771 If CONFIG_ENV_OVERWRITE is #defined in your config
2772 file, the write protection for vendor parameters is
2773 completely disabled. Anybody can change or delete
2776 Alternatively, if you define _both_ an ethaddr in the
2777 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2778 Ethernet address is installed in the environment,
2779 which can be changed exactly ONCE by the user. [The
2780 serial# is unaffected by this, i. e. it remains
2783 The same can be accomplished in a more flexible way
2784 for any variable by configuring the type of access
2785 to allow for those variables in the ".flags" variable
2786 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2791 Define this variable to enable the reservation of
2792 "protected RAM", i. e. RAM which is not overwritten
2793 by U-Boot. Define CONFIG_PRAM to hold the number of
2794 kB you want to reserve for pRAM. You can overwrite
2795 this default value by defining an environment
2796 variable "pram" to the number of kB you want to
2797 reserve. Note that the board info structure will
2798 still show the full amount of RAM. If pRAM is
2799 reserved, a new environment variable "mem" will
2800 automatically be defined to hold the amount of
2801 remaining RAM in a form that can be passed as boot
2802 argument to Linux, for instance like that:
2804 setenv bootargs ... mem=\${mem}
2807 This way you can tell Linux not to use this memory,
2808 either, which results in a memory region that will
2809 not be affected by reboots.
2811 *WARNING* If your board configuration uses automatic
2812 detection of the RAM size, you must make sure that
2813 this memory test is non-destructive. So far, the
2814 following board configurations are known to be
2817 IVMS8, IVML24, SPD8xx, TQM8xxL,
2818 HERMES, IP860, RPXlite, LWMON,
2821 - Access to physical memory region (> 4GB)
2822 Some basic support is provided for operations on memory not
2823 normally accessible to U-Boot - e.g. some architectures
2824 support access to more than 4GB of memory on 32-bit
2825 machines using physical address extension or similar.
2826 Define CONFIG_PHYSMEM to access this basic support, which
2827 currently only supports clearing the memory.
2832 Define this variable to stop the system in case of a
2833 fatal error, so that you have to reset it manually.
2834 This is probably NOT a good idea for an embedded
2835 system where you want the system to reboot
2836 automatically as fast as possible, but it may be
2837 useful during development since you can try to debug
2838 the conditions that lead to the situation.
2840 CONFIG_NET_RETRY_COUNT
2842 This variable defines the number of retries for
2843 network operations like ARP, RARP, TFTP, or BOOTP
2844 before giving up the operation. If not defined, a
2845 default value of 5 is used.
2849 Timeout waiting for an ARP reply in milliseconds.
2853 Timeout in milliseconds used in NFS protocol.
2854 If you encounter "ERROR: Cannot umount" in nfs command,
2855 try longer timeout such as
2856 #define CONFIG_NFS_TIMEOUT 10000UL
2858 - Command Interpreter:
2859 CONFIG_AUTO_COMPLETE
2861 Enable auto completion of commands using TAB.
2863 CONFIG_SYS_PROMPT_HUSH_PS2
2865 This defines the secondary prompt string, which is
2866 printed when the command interpreter needs more input
2867 to complete a command. Usually "> ".
2871 In the current implementation, the local variables
2872 space and global environment variables space are
2873 separated. Local variables are those you define by
2874 simply typing `name=value'. To access a local
2875 variable later on, you have write `$name' or
2876 `${name}'; to execute the contents of a variable
2877 directly type `$name' at the command prompt.
2879 Global environment variables are those you use
2880 setenv/printenv to work with. To run a command stored
2881 in such a variable, you need to use the run command,
2882 and you must not use the '$' sign to access them.
2884 To store commands and special characters in a
2885 variable, please use double quotation marks
2886 surrounding the whole text of the variable, instead
2887 of the backslashes before semicolons and special
2890 - Command Line Editing and History:
2891 CONFIG_CMDLINE_EDITING
2893 Enable editing and History functions for interactive
2894 command line input operations
2896 - Command Line PS1/PS2 support:
2897 CONFIG_CMDLINE_PS_SUPPORT
2899 Enable support for changing the command prompt string
2900 at run-time. Only static string is supported so far.
2901 The string is obtained from environment variables PS1
2904 - Default Environment:
2905 CONFIG_EXTRA_ENV_SETTINGS
2907 Define this to contain any number of null terminated
2908 strings (variable = value pairs) that will be part of
2909 the default environment compiled into the boot image.
2911 For example, place something like this in your
2912 board's config file:
2914 #define CONFIG_EXTRA_ENV_SETTINGS \
2918 Warning: This method is based on knowledge about the
2919 internal format how the environment is stored by the
2920 U-Boot code. This is NOT an official, exported
2921 interface! Although it is unlikely that this format
2922 will change soon, there is no guarantee either.
2923 You better know what you are doing here.
2925 Note: overly (ab)use of the default environment is
2926 discouraged. Make sure to check other ways to preset
2927 the environment like the "source" command or the
2930 CONFIG_ENV_VARS_UBOOT_CONFIG
2932 Define this in order to add variables describing the
2933 U-Boot build configuration to the default environment.
2934 These will be named arch, cpu, board, vendor, and soc.
2936 Enabling this option will cause the following to be defined:
2944 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2946 Define this in order to add variables describing certain
2947 run-time determined information about the hardware to the
2948 environment. These will be named board_name, board_rev.
2950 CONFIG_DELAY_ENVIRONMENT
2952 Normally the environment is loaded when the board is
2953 initialised so that it is available to U-Boot. This inhibits
2954 that so that the environment is not available until
2955 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2956 this is instead controlled by the value of
2957 /config/load-environment.
2959 - Parallel Flash support:
2962 Traditionally U-Boot was run on systems with parallel NOR
2963 flash. This option is used to disable support for parallel NOR
2964 flash. This option should be defined if the board does not have
2967 If this option is not defined one of the generic flash drivers
2968 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2969 selected or the board must provide an implementation of the
2970 flash API (see include/flash.h).
2972 - DataFlash Support:
2973 CONFIG_HAS_DATAFLASH
2975 Defining this option enables DataFlash features and
2976 allows to read/write in Dataflash via the standard
2979 - Serial Flash support
2982 Defining this option enables SPI flash commands
2983 'sf probe/read/write/erase/update'.
2985 Usage requires an initial 'probe' to define the serial
2986 flash parameters, followed by read/write/erase/update
2989 The following defaults may be provided by the platform
2990 to handle the common case when only a single serial
2991 flash is present on the system.
2993 CONFIG_SF_DEFAULT_BUS Bus identifier
2994 CONFIG_SF_DEFAULT_CS Chip-select
2995 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2996 CONFIG_SF_DEFAULT_SPEED in Hz
3000 Define this option to include a destructive SPI flash
3003 CONFIG_SF_DUAL_FLASH Dual flash memories
3005 Define this option to use dual flash support where two flash
3006 memories can be connected with a given cs line.
3007 Currently Xilinx Zynq qspi supports these type of connections.
3009 - SystemACE Support:
3012 Adding this option adds support for Xilinx SystemACE
3013 chips attached via some sort of local bus. The address
3014 of the chip must also be defined in the
3015 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3017 #define CONFIG_SYSTEMACE
3018 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3020 When SystemACE support is added, the "ace" device type
3021 becomes available to the fat commands, i.e. fatls.
3023 - TFTP Fixed UDP Port:
3026 If this is defined, the environment variable tftpsrcp
3027 is used to supply the TFTP UDP source port value.
3028 If tftpsrcp isn't defined, the normal pseudo-random port
3029 number generator is used.
3031 Also, the environment variable tftpdstp is used to supply
3032 the TFTP UDP destination port value. If tftpdstp isn't
3033 defined, the normal port 69 is used.
3035 The purpose for tftpsrcp is to allow a TFTP server to
3036 blindly start the TFTP transfer using the pre-configured
3037 target IP address and UDP port. This has the effect of
3038 "punching through" the (Windows XP) firewall, allowing
3039 the remainder of the TFTP transfer to proceed normally.
3040 A better solution is to properly configure the firewall,
3041 but sometimes that is not allowed.
3046 This enables a generic 'hash' command which can produce
3047 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3051 Enable the hash verify command (hash -v). This adds to code
3054 CONFIG_SHA1 - This option enables support of hashing using SHA1
3055 algorithm. The hash is calculated in software.
3056 CONFIG_SHA256 - This option enables support of hashing using
3057 SHA256 algorithm. The hash is calculated in software.
3058 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3059 for SHA1/SHA256 hashing.
3060 This affects the 'hash' command and also the
3061 hash_lookup_algo() function.
3062 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3063 hardware-acceleration for SHA1/SHA256 progressive hashing.
3064 Data can be streamed in a block at a time and the hashing
3065 is performed in hardware.
3067 Note: There is also a sha1sum command, which should perhaps
3068 be deprecated in favour of 'hash sha1'.
3070 - Freescale i.MX specific commands:
3071 CONFIG_CMD_HDMIDETECT
3072 This enables 'hdmidet' command which returns true if an
3073 HDMI monitor is detected. This command is i.MX 6 specific.
3076 This enables the 'bmode' (bootmode) command for forcing
3077 a boot from specific media.
3079 This is useful for forcing the ROM's usb downloader to
3080 activate upon a watchdog reset which is nice when iterating
3081 on U-Boot. Using the reset button or running bmode normal
3082 will set it back to normal. This command currently
3083 supports i.MX53 and i.MX6.
3085 - bootcount support:
3086 CONFIG_BOOTCOUNT_LIMIT
3088 This enables the bootcounter support, see:
3089 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3092 enable special bootcounter support on at91sam9xe based boards.
3094 enable special bootcounter support on blackfin based boards.
3096 enable special bootcounter support on da850 based boards.
3097 CONFIG_BOOTCOUNT_RAM
3098 enable support for the bootcounter in RAM
3099 CONFIG_BOOTCOUNT_I2C
3100 enable support for the bootcounter on an i2c (like RTC) device.
3101 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3102 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3104 CONFIG_BOOTCOUNT_ALEN = address len
3106 - Show boot progress:
3107 CONFIG_SHOW_BOOT_PROGRESS
3109 Defining this option allows to add some board-
3110 specific code (calling a user-provided function
3111 "show_boot_progress(int)") that enables you to show
3112 the system's boot progress on some display (for
3113 example, some LED's) on your board. At the moment,
3114 the following checkpoints are implemented:
3117 Legacy uImage format:
3120 1 common/cmd_bootm.c before attempting to boot an image
3121 -1 common/cmd_bootm.c Image header has bad magic number
3122 2 common/cmd_bootm.c Image header has correct magic number
3123 -2 common/cmd_bootm.c Image header has bad checksum
3124 3 common/cmd_bootm.c Image header has correct checksum
3125 -3 common/cmd_bootm.c Image data has bad checksum
3126 4 common/cmd_bootm.c Image data has correct checksum
3127 -4 common/cmd_bootm.c Image is for unsupported architecture
3128 5 common/cmd_bootm.c Architecture check OK
3129 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3130 6 common/cmd_bootm.c Image Type check OK
3131 -6 common/cmd_bootm.c gunzip uncompression error
3132 -7 common/cmd_bootm.c Unimplemented compression type
3133 7 common/cmd_bootm.c Uncompression OK
3134 8 common/cmd_bootm.c No uncompress/copy overwrite error
3135 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3137 9 common/image.c Start initial ramdisk verification
3138 -10 common/image.c Ramdisk header has bad magic number
3139 -11 common/image.c Ramdisk header has bad checksum
3140 10 common/image.c Ramdisk header is OK
3141 -12 common/image.c Ramdisk data has bad checksum
3142 11 common/image.c Ramdisk data has correct checksum
3143 12 common/image.c Ramdisk verification complete, start loading
3144 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3145 13 common/image.c Start multifile image verification
3146 14 common/image.c No initial ramdisk, no multifile, continue.
3148 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3150 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3151 -31 post/post.c POST test failed, detected by post_output_backlog()
3152 -32 post/post.c POST test failed, detected by post_run_single()
3154 34 common/cmd_doc.c before loading a Image from a DOC device
3155 -35 common/cmd_doc.c Bad usage of "doc" command
3156 35 common/cmd_doc.c correct usage of "doc" command
3157 -36 common/cmd_doc.c No boot device
3158 36 common/cmd_doc.c correct boot device
3159 -37 common/cmd_doc.c Unknown Chip ID on boot device
3160 37 common/cmd_doc.c correct chip ID found, device available
3161 -38 common/cmd_doc.c Read Error on boot device
3162 38 common/cmd_doc.c reading Image header from DOC device OK
3163 -39 common/cmd_doc.c Image header has bad magic number
3164 39 common/cmd_doc.c Image header has correct magic number
3165 -40 common/cmd_doc.c Error reading Image from DOC device
3166 40 common/cmd_doc.c Image header has correct magic number
3167 41 common/cmd_ide.c before loading a Image from a IDE device
3168 -42 common/cmd_ide.c Bad usage of "ide" command
3169 42 common/cmd_ide.c correct usage of "ide" command
3170 -43 common/cmd_ide.c No boot device
3171 43 common/cmd_ide.c boot device found
3172 -44 common/cmd_ide.c Device not available
3173 44 common/cmd_ide.c Device available
3174 -45 common/cmd_ide.c wrong partition selected
3175 45 common/cmd_ide.c partition selected
3176 -46 common/cmd_ide.c Unknown partition table
3177 46 common/cmd_ide.c valid partition table found
3178 -47 common/cmd_ide.c Invalid partition type
3179 47 common/cmd_ide.c correct partition type
3180 -48 common/cmd_ide.c Error reading Image Header on boot device
3181 48 common/cmd_ide.c reading Image Header from IDE device OK
3182 -49 common/cmd_ide.c Image header has bad magic number
3183 49 common/cmd_ide.c Image header has correct magic number
3184 -50 common/cmd_ide.c Image header has bad checksum
3185 50 common/cmd_ide.c Image header has correct checksum
3186 -51 common/cmd_ide.c Error reading Image from IDE device
3187 51 common/cmd_ide.c reading Image from IDE device OK
3188 52 common/cmd_nand.c before loading a Image from a NAND device
3189 -53 common/cmd_nand.c Bad usage of "nand" command
3190 53 common/cmd_nand.c correct usage of "nand" command
3191 -54 common/cmd_nand.c No boot device
3192 54 common/cmd_nand.c boot device found
3193 -55 common/cmd_nand.c Unknown Chip ID on boot device
3194 55 common/cmd_nand.c correct chip ID found, device available
3195 -56 common/cmd_nand.c Error reading Image Header on boot device
3196 56 common/cmd_nand.c reading Image Header from NAND device OK
3197 -57 common/cmd_nand.c Image header has bad magic number
3198 57 common/cmd_nand.c Image header has correct magic number
3199 -58 common/cmd_nand.c Error reading Image from NAND device
3200 58 common/cmd_nand.c reading Image from NAND device OK
3202 -60 common/env_common.c Environment has a bad CRC, using default
3204 64 net/eth.c starting with Ethernet configuration.
3205 -64 net/eth.c no Ethernet found.
3206 65 net/eth.c Ethernet found.
3208 -80 common/cmd_net.c usage wrong
3209 80 common/cmd_net.c before calling net_loop()
3210 -81 common/cmd_net.c some error in net_loop() occurred
3211 81 common/cmd_net.c net_loop() back without error
3212 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3213 82 common/cmd_net.c trying automatic boot
3214 83 common/cmd_net.c running "source" command
3215 -83 common/cmd_net.c some error in automatic boot or "source" command
3216 84 common/cmd_net.c end without errors
3221 100 common/cmd_bootm.c Kernel FIT Image has correct format
3222 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3223 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3224 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3225 102 common/cmd_bootm.c Kernel unit name specified
3226 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3227 103 common/cmd_bootm.c Found configuration node
3228 104 common/cmd_bootm.c Got kernel subimage node offset
3229 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3230 105 common/cmd_bootm.c Kernel subimage hash verification OK
3231 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3232 106 common/cmd_bootm.c Architecture check OK
3233 -106 common/cmd_bootm.c Kernel subimage has wrong type
3234 107 common/cmd_bootm.c Kernel subimage type OK
3235 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3236 108 common/cmd_bootm.c Got kernel subimage data/size
3237 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3238 -109 common/cmd_bootm.c Can't get kernel subimage type
3239 -110 common/cmd_bootm.c Can't get kernel subimage comp
3240 -111 common/cmd_bootm.c Can't get kernel subimage os
3241 -112 common/cmd_bootm.c Can't get kernel subimage load address
3242 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3244 120 common/image.c Start initial ramdisk verification
3245 -120 common/image.c Ramdisk FIT image has incorrect format
3246 121 common/image.c Ramdisk FIT image has correct format
3247 122 common/image.c No ramdisk subimage unit name, using configuration
3248 -122 common/image.c Can't get configuration for ramdisk subimage
3249 123 common/image.c Ramdisk unit name specified
3250 -124 common/image.c Can't get ramdisk subimage node offset
3251 125 common/image.c Got ramdisk subimage node offset
3252 -125 common/image.c Ramdisk subimage hash verification failed
3253 126 common/image.c Ramdisk subimage hash verification OK
3254 -126 common/image.c Ramdisk subimage for unsupported architecture
3255 127 common/image.c Architecture check OK
3256 -127 common/image.c Can't get ramdisk subimage data/size
3257 128 common/image.c Got ramdisk subimage data/size
3258 129 common/image.c Can't get ramdisk load address
3259 -129 common/image.c Got ramdisk load address
3261 -130 common/cmd_doc.c Incorrect FIT image format
3262 131 common/cmd_doc.c FIT image format OK
3264 -140 common/cmd_ide.c Incorrect FIT image format
3265 141 common/cmd_ide.c FIT image format OK
3267 -150 common/cmd_nand.c Incorrect FIT image format
3268 151 common/cmd_nand.c FIT image format OK
3270 - legacy image format:
3271 CONFIG_IMAGE_FORMAT_LEGACY
3272 enables the legacy image format support in U-Boot.
3275 enabled if CONFIG_FIT_SIGNATURE is not defined.
3277 CONFIG_DISABLE_IMAGE_LEGACY
3278 disable the legacy image format
3280 This define is introduced, as the legacy image format is
3281 enabled per default for backward compatibility.
3283 - FIT image support:
3284 CONFIG_FIT_DISABLE_SHA256
3285 Supporting SHA256 hashes has quite an impact on binary size.
3286 For constrained systems sha256 hash support can be disabled
3289 TODO(sjg@chromium.org): Adjust this option to be positive,
3290 and move it to Kconfig
3292 - Standalone program support:
3293 CONFIG_STANDALONE_LOAD_ADDR
3295 This option defines a board specific value for the
3296 address where standalone program gets loaded, thus
3297 overwriting the architecture dependent default
3300 - Frame Buffer Address:
3303 Define CONFIG_FB_ADDR if you want to use specific
3304 address for frame buffer. This is typically the case
3305 when using a graphics controller has separate video
3306 memory. U-Boot will then place the frame buffer at
3307 the given address instead of dynamically reserving it
3308 in system RAM by calling lcd_setmem(), which grabs
3309 the memory for the frame buffer depending on the
3310 configured panel size.
3312 Please see board_init_f function.
3314 - Automatic software updates via TFTP server
3316 CONFIG_UPDATE_TFTP_CNT_MAX
3317 CONFIG_UPDATE_TFTP_MSEC_MAX
3319 These options enable and control the auto-update feature;
3320 for a more detailed description refer to doc/README.update.
3322 - MTD Support (mtdparts command, UBI support)
3325 Adds the MTD device infrastructure from the Linux kernel.
3326 Needed for mtdparts command support.
3328 CONFIG_MTD_PARTITIONS
3330 Adds the MTD partitioning infrastructure from the Linux
3331 kernel. Needed for UBI support.
3336 Adds commands for interacting with MTD partitions formatted
3337 with the UBI flash translation layer
3339 Requires also defining CONFIG_RBTREE
3341 CONFIG_UBI_SILENCE_MSG
3343 Make the verbose messages from UBI stop printing. This leaves
3344 warnings and errors enabled.
3347 CONFIG_MTD_UBI_WL_THRESHOLD
3348 This parameter defines the maximum difference between the highest
3349 erase counter value and the lowest erase counter value of eraseblocks
3350 of UBI devices. When this threshold is exceeded, UBI starts performing
3351 wear leveling by means of moving data from eraseblock with low erase
3352 counter to eraseblocks with high erase counter.
3354 The default value should be OK for SLC NAND flashes, NOR flashes and
3355 other flashes which have eraseblock life-cycle 100000 or more.
3356 However, in case of MLC NAND flashes which typically have eraseblock
3357 life-cycle less than 10000, the threshold should be lessened (e.g.,
3358 to 128 or 256, although it does not have to be power of 2).
3362 CONFIG_MTD_UBI_BEB_LIMIT
3363 This option specifies the maximum bad physical eraseblocks UBI
3364 expects on the MTD device (per 1024 eraseblocks). If the
3365 underlying flash does not admit of bad eraseblocks (e.g. NOR
3366 flash), this value is ignored.
3368 NAND datasheets often specify the minimum and maximum NVM
3369 (Number of Valid Blocks) for the flashes' endurance lifetime.
3370 The maximum expected bad eraseblocks per 1024 eraseblocks
3371 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3372 which gives 20 for most NANDs (MaxNVB is basically the total
3373 count of eraseblocks on the chip).
3375 To put it differently, if this value is 20, UBI will try to
3376 reserve about 1.9% of physical eraseblocks for bad blocks
3377 handling. And that will be 1.9% of eraseblocks on the entire
3378 NAND chip, not just the MTD partition UBI attaches. This means
3379 that if you have, say, a NAND flash chip admits maximum 40 bad
3380 eraseblocks, and it is split on two MTD partitions of the same
3381 size, UBI will reserve 40 eraseblocks when attaching a
3386 CONFIG_MTD_UBI_FASTMAP
3387 Fastmap is a mechanism which allows attaching an UBI device
3388 in nearly constant time. Instead of scanning the whole MTD device it
3389 only has to locate a checkpoint (called fastmap) on the device.
3390 The on-flash fastmap contains all information needed to attach
3391 the device. Using fastmap makes only sense on large devices where
3392 attaching by scanning takes long. UBI will not automatically install
3393 a fastmap on old images, but you can set the UBI parameter
3394 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3395 that fastmap-enabled images are still usable with UBI implementations
3396 without fastmap support. On typical flash devices the whole fastmap
3397 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3399 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3400 Set this parameter to enable fastmap automatically on images
3404 CONFIG_MTD_UBI_FM_DEBUG
3405 Enable UBI fastmap debug
3411 Adds commands for interacting with UBI volumes formatted as
3412 UBIFS. UBIFS is read-only in u-boot.
3414 Requires UBI support as well as CONFIG_LZO
3416 CONFIG_UBIFS_SILENCE_MSG
3418 Make the verbose messages from UBIFS stop printing. This leaves
3419 warnings and errors enabled.
3423 Enable building of SPL globally.
3426 LDSCRIPT for linking the SPL binary.
3428 CONFIG_SPL_MAX_FOOTPRINT
3429 Maximum size in memory allocated to the SPL, BSS included.
3430 When defined, the linker checks that the actual memory
3431 used by SPL from _start to __bss_end does not exceed it.
3432 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3433 must not be both defined at the same time.
3436 Maximum size of the SPL image (text, data, rodata, and
3437 linker lists sections), BSS excluded.
3438 When defined, the linker checks that the actual size does
3441 CONFIG_SPL_TEXT_BASE
3442 TEXT_BASE for linking the SPL binary.
3444 CONFIG_SPL_RELOC_TEXT_BASE
3445 Address to relocate to. If unspecified, this is equal to
3446 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3448 CONFIG_SPL_BSS_START_ADDR
3449 Link address for the BSS within the SPL binary.
3451 CONFIG_SPL_BSS_MAX_SIZE
3452 Maximum size in memory allocated to the SPL BSS.
3453 When defined, the linker checks that the actual memory used
3454 by SPL from __bss_start to __bss_end does not exceed it.
3455 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3456 must not be both defined at the same time.
3459 Adress of the start of the stack SPL will use
3461 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3462 When defined, SPL will panic() if the image it has
3463 loaded does not have a signature.
3464 Defining this is useful when code which loads images
3465 in SPL cannot guarantee that absolutely all read errors
3467 An example is the LPC32XX MLC NAND driver, which will
3468 consider that a completely unreadable NAND block is bad,
3469 and thus should be skipped silently.
3471 CONFIG_SPL_ABORT_ON_RAW_IMAGE
3472 When defined, SPL will proceed to another boot method
3473 if the image it has loaded does not have a signature.
3475 CONFIG_SPL_RELOC_STACK
3476 Adress of the start of the stack SPL will use after
3477 relocation. If unspecified, this is equal to
3480 CONFIG_SYS_SPL_MALLOC_START
3481 Starting address of the malloc pool used in SPL.
3482 When this option is set the full malloc is used in SPL and
3483 it is set up by spl_init() and before that, the simple malloc()
3484 can be used if CONFIG_SYS_MALLOC_F is defined.
3486 CONFIG_SYS_SPL_MALLOC_SIZE
3487 The size of the malloc pool used in SPL.
3489 CONFIG_SPL_FRAMEWORK
3490 Enable the SPL framework under common/. This framework
3491 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3492 NAND loading of the Linux Kernel.
3495 Enable booting directly to an OS from SPL.
3496 See also: doc/README.falcon
3498 CONFIG_SPL_DISPLAY_PRINT
3499 For ARM, enable an optional function to print more information
3500 about the running system.
3502 CONFIG_SPL_INIT_MINIMAL
3503 Arch init code should be built for a very small image
3505 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3506 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3507 Address and partition on the MMC to load U-Boot from
3508 when the MMC is being used in raw mode.
3510 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3511 Partition on the MMC to load U-Boot from when the MMC is being
3514 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3515 Sector to load kernel uImage from when MMC is being
3516 used in raw mode (for Falcon mode)
3518 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3519 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3520 Sector and number of sectors to load kernel argument
3521 parameters from when MMC is being used in raw mode
3524 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3525 Partition on the MMC to load U-Boot from when the MMC is being
3528 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3529 Filename to read to load U-Boot when reading from filesystem
3531 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3532 Filename to read to load kernel uImage when reading
3533 from filesystem (for Falcon mode)
3535 CONFIG_SPL_FS_LOAD_ARGS_NAME
3536 Filename to read to load kernel argument parameters
3537 when reading from filesystem (for Falcon mode)
3539 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3540 Set this for NAND SPL on PPC mpc83xx targets, so that
3541 start.S waits for the rest of the SPL to load before
3542 continuing (the hardware starts execution after just
3543 loading the first page rather than the full 4K).
3545 CONFIG_SPL_SKIP_RELOCATE
3546 Avoid SPL relocation
3548 CONFIG_SPL_NAND_BASE
3549 Include nand_base.c in the SPL. Requires
3550 CONFIG_SPL_NAND_DRIVERS.
3552 CONFIG_SPL_NAND_DRIVERS
3553 SPL uses normal NAND drivers, not minimal drivers.
3556 Include standard software ECC in the SPL
3558 CONFIG_SPL_NAND_SIMPLE
3559 Support for NAND boot using simple NAND drivers that
3560 expose the cmd_ctrl() interface.
3563 Support for a lightweight UBI (fastmap) scanner and
3566 CONFIG_SPL_NAND_RAW_ONLY
3567 Support to boot only raw u-boot.bin images. Use this only
3568 if you need to save space.
3570 CONFIG_SPL_COMMON_INIT_DDR
3571 Set for common ddr init with serial presence detect in
3574 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3575 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3576 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3577 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3578 CONFIG_SYS_NAND_ECCBYTES
3579 Defines the size and behavior of the NAND that SPL uses
3582 CONFIG_SPL_NAND_BOOT
3583 Add support NAND boot
3585 CONFIG_SYS_NAND_U_BOOT_OFFS
3586 Location in NAND to read U-Boot from
3588 CONFIG_SYS_NAND_U_BOOT_DST
3589 Location in memory to load U-Boot to
3591 CONFIG_SYS_NAND_U_BOOT_SIZE
3592 Size of image to load
3594 CONFIG_SYS_NAND_U_BOOT_START
3595 Entry point in loaded image to jump to
3597 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3598 Define this if you need to first read the OOB and then the
3599 data. This is used, for example, on davinci platforms.
3601 CONFIG_SPL_OMAP3_ID_NAND
3602 Support for an OMAP3-specific set of functions to return the
3603 ID and MFR of the first attached NAND chip, if present.
3605 CONFIG_SPL_RAM_DEVICE
3606 Support for running image already present in ram, in SPL binary
3609 Image offset to which the SPL should be padded before appending
3610 the SPL payload. By default, this is defined as
3611 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3612 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3613 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3616 Final target image containing SPL and payload. Some SPLs
3617 use an arch-specific makefile fragment instead, for
3618 example if more than one image needs to be produced.
3620 CONFIG_FIT_SPL_PRINT
3621 Printing information about a FIT image adds quite a bit of
3622 code to SPL. So this is normally disabled in SPL. Use this
3623 option to re-enable it. This will affect the output of the
3624 bootm command when booting a FIT image.
3628 Enable building of TPL globally.
3631 Image offset to which the TPL should be padded before appending
3632 the TPL payload. By default, this is defined as
3633 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3634 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3635 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3637 - Interrupt support (PPC):
3639 There are common interrupt_init() and timer_interrupt()
3640 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3641 for CPU specific initialization. interrupt_init_cpu()
3642 should set decrementer_count to appropriate value. If
3643 CPU resets decrementer automatically after interrupt
3644 (ppc4xx) it should set decrementer_count to zero.
3645 timer_interrupt() calls timer_interrupt_cpu() for CPU
3646 specific handling. If board has watchdog / status_led
3647 / other_activity_monitor it works automatically from
3648 general timer_interrupt().
3651 Board initialization settings:
3652 ------------------------------
3654 During Initialization u-boot calls a number of board specific functions
3655 to allow the preparation of board specific prerequisites, e.g. pin setup
3656 before drivers are initialized. To enable these callbacks the
3657 following configuration macros have to be defined. Currently this is
3658 architecture specific, so please check arch/your_architecture/lib/board.c
3659 typically in board_init_f() and board_init_r().
3661 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3662 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3663 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3664 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3666 Configuration Settings:
3667 -----------------------
3669 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3670 Optionally it can be defined to support 64-bit memory commands.
3672 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3673 undefine this when you're short of memory.
3675 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3676 width of the commands listed in the 'help' command output.
3678 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3679 prompt for user input.
3681 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3683 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3685 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3687 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3688 the application (usually a Linux kernel) when it is
3691 - CONFIG_SYS_BAUDRATE_TABLE:
3692 List of legal baudrate settings for this board.
3694 - CONFIG_SYS_CONSOLE_INFO_QUIET
3695 Suppress display of console information at boot.
3697 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3698 If the board specific function
3699 extern int overwrite_console (void);
3700 returns 1, the stdin, stderr and stdout are switched to the
3701 serial port, else the settings in the environment are used.
3703 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3704 Enable the call to overwrite_console().
3706 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3707 Enable overwrite of previous console environment settings.
3709 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3710 Begin and End addresses of the area used by the
3713 - CONFIG_SYS_ALT_MEMTEST:
3714 Enable an alternate, more extensive memory test.
3716 - CONFIG_SYS_MEMTEST_SCRATCH:
3717 Scratch address used by the alternate memory test
3718 You only need to set this if address zero isn't writeable
3720 - CONFIG_SYS_MEM_RESERVE_SECURE
3721 Only implemented for ARMv8 for now.
3722 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3723 is substracted from total RAM and won't be reported to OS.
3724 This memory can be used as secure memory. A variable
3725 gd->arch.secure_ram is used to track the location. In systems
3726 the RAM base is not zero, or RAM is divided into banks,
3727 this variable needs to be recalcuated to get the address.
3729 - CONFIG_SYS_MEM_TOP_HIDE:
3730 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3731 this specified memory area will get subtracted from the top
3732 (end) of RAM and won't get "touched" at all by U-Boot. By
3733 fixing up gd->ram_size the Linux kernel should gets passed
3734 the now "corrected" memory size and won't touch it either.
3735 This should work for arch/ppc and arch/powerpc. Only Linux
3736 board ports in arch/powerpc with bootwrapper support that
3737 recalculate the memory size from the SDRAM controller setup
3738 will have to get fixed in Linux additionally.
3740 This option can be used as a workaround for the 440EPx/GRx
3741 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3744 WARNING: Please make sure that this value is a multiple of
3745 the Linux page size (normally 4k). If this is not the case,
3746 then the end address of the Linux memory will be located at a
3747 non page size aligned address and this could cause major
3750 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3751 Enable temporary baudrate change while serial download
3753 - CONFIG_SYS_SDRAM_BASE:
3754 Physical start address of SDRAM. _Must_ be 0 here.
3756 - CONFIG_SYS_MBIO_BASE:
3757 Physical start address of Motherboard I/O (if using a
3760 - CONFIG_SYS_FLASH_BASE:
3761 Physical start address of Flash memory.
3763 - CONFIG_SYS_MONITOR_BASE:
3764 Physical start address of boot monitor code (set by
3765 make config files to be same as the text base address
3766 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3767 CONFIG_SYS_FLASH_BASE when booting from flash.
3769 - CONFIG_SYS_MONITOR_LEN:
3770 Size of memory reserved for monitor code, used to
3771 determine _at_compile_time_ (!) if the environment is
3772 embedded within the U-Boot image, or in a separate
3775 - CONFIG_SYS_MALLOC_LEN:
3776 Size of DRAM reserved for malloc() use.
3778 - CONFIG_SYS_MALLOC_F_LEN
3779 Size of the malloc() pool for use before relocation. If
3780 this is defined, then a very simple malloc() implementation
3781 will become available before relocation. The address is just
3782 below the global data, and the stack is moved down to make
3785 This feature allocates regions with increasing addresses
3786 within the region. calloc() is supported, but realloc()
3787 is not available. free() is supported but does nothing.
3788 The memory will be freed (or in fact just forgotten) when
3789 U-Boot relocates itself.
3791 - CONFIG_SYS_MALLOC_SIMPLE
3792 Provides a simple and small malloc() and calloc() for those
3793 boards which do not use the full malloc in SPL (which is
3794 enabled with CONFIG_SYS_SPL_MALLOC_START).
3796 - CONFIG_SYS_NONCACHED_MEMORY:
3797 Size of non-cached memory area. This area of memory will be
3798 typically located right below the malloc() area and mapped
3799 uncached in the MMU. This is useful for drivers that would
3800 otherwise require a lot of explicit cache maintenance. For
3801 some drivers it's also impossible to properly maintain the
3802 cache. For example if the regions that need to be flushed
3803 are not a multiple of the cache-line size, *and* padding
3804 cannot be allocated between the regions to align them (i.e.
3805 if the HW requires a contiguous array of regions, and the
3806 size of each region is not cache-aligned), then a flush of
3807 one region may result in overwriting data that hardware has
3808 written to another region in the same cache-line. This can
3809 happen for example in network drivers where descriptors for
3810 buffers are typically smaller than the CPU cache-line (e.g.
3811 16 bytes vs. 32 or 64 bytes).
3813 Non-cached memory is only supported on 32-bit ARM at present.
3815 - CONFIG_SYS_BOOTM_LEN:
3816 Normally compressed uImages are limited to an
3817 uncompressed size of 8 MBytes. If this is not enough,
3818 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3819 to adjust this setting to your needs.
3821 - CONFIG_SYS_BOOTMAPSZ:
3822 Maximum size of memory mapped by the startup code of
3823 the Linux kernel; all data that must be processed by
3824 the Linux kernel (bd_info, boot arguments, FDT blob if
3825 used) must be put below this limit, unless "bootm_low"
3826 environment variable is defined and non-zero. In such case
3827 all data for the Linux kernel must be between "bootm_low"
3828 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3829 variable "bootm_mapsize" will override the value of
3830 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3831 then the value in "bootm_size" will be used instead.
3833 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3834 Enable initrd_high functionality. If defined then the
3835 initrd_high feature is enabled and the bootm ramdisk subcommand
3838 - CONFIG_SYS_BOOT_GET_CMDLINE:
3839 Enables allocating and saving kernel cmdline in space between
3840 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3842 - CONFIG_SYS_BOOT_GET_KBD:
3843 Enables allocating and saving a kernel copy of the bd_info in
3844 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3846 - CONFIG_SYS_MAX_FLASH_BANKS:
3847 Max number of Flash memory banks
3849 - CONFIG_SYS_MAX_FLASH_SECT:
3850 Max number of sectors on a Flash chip
3852 - CONFIG_SYS_FLASH_ERASE_TOUT:
3853 Timeout for Flash erase operations (in ms)
3855 - CONFIG_SYS_FLASH_WRITE_TOUT:
3856 Timeout for Flash write operations (in ms)
3858 - CONFIG_SYS_FLASH_LOCK_TOUT
3859 Timeout for Flash set sector lock bit operation (in ms)
3861 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3862 Timeout for Flash clear lock bits operation (in ms)
3864 - CONFIG_SYS_FLASH_PROTECTION
3865 If defined, hardware flash sectors protection is used
3866 instead of U-Boot software protection.
3868 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3870 Enable TFTP transfers directly to flash memory;
3871 without this option such a download has to be
3872 performed in two steps: (1) download to RAM, and (2)
3873 copy from RAM to flash.
3875 The two-step approach is usually more reliable, since
3876 you can check if the download worked before you erase
3877 the flash, but in some situations (when system RAM is
3878 too limited to allow for a temporary copy of the
3879 downloaded image) this option may be very useful.
3881 - CONFIG_SYS_FLASH_CFI:
3882 Define if the flash driver uses extra elements in the
3883 common flash structure for storing flash geometry.
3885 - CONFIG_FLASH_CFI_DRIVER
3886 This option also enables the building of the cfi_flash driver
3887 in the drivers directory
3889 - CONFIG_FLASH_CFI_MTD
3890 This option enables the building of the cfi_mtd driver
3891 in the drivers directory. The driver exports CFI flash
3894 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3895 Use buffered writes to flash.
3897 - CONFIG_FLASH_SPANSION_S29WS_N
3898 s29ws-n MirrorBit flash has non-standard addresses for buffered
3901 - CONFIG_SYS_FLASH_QUIET_TEST
3902 If this option is defined, the common CFI flash doesn't
3903 print it's warning upon not recognized FLASH banks. This
3904 is useful, if some of the configured banks are only
3905 optionally available.
3907 - CONFIG_FLASH_SHOW_PROGRESS
3908 If defined (must be an integer), print out countdown
3909 digits and dots. Recommended value: 45 (9..1) for 80
3910 column displays, 15 (3..1) for 40 column displays.
3912 - CONFIG_FLASH_VERIFY
3913 If defined, the content of the flash (destination) is compared
3914 against the source after the write operation. An error message
3915 will be printed when the contents are not identical.
3916 Please note that this option is useless in nearly all cases,
3917 since such flash programming errors usually are detected earlier
3918 while unprotecting/erasing/programming. Please only enable
3919 this option if you really know what you are doing.
3921 - CONFIG_SYS_RX_ETH_BUFFER:
3922 Defines the number of Ethernet receive buffers. On some
3923 Ethernet controllers it is recommended to set this value
3924 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3925 buffers can be full shortly after enabling the interface
3926 on high Ethernet traffic.
3927 Defaults to 4 if not defined.
3929 - CONFIG_ENV_MAX_ENTRIES
3931 Maximum number of entries in the hash table that is used
3932 internally to store the environment settings. The default
3933 setting is supposed to be generous and should work in most
3934 cases. This setting can be used to tune behaviour; see
3935 lib/hashtable.c for details.
3937 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3938 - CONFIG_ENV_FLAGS_LIST_STATIC
3939 Enable validation of the values given to environment variables when
3940 calling env set. Variables can be restricted to only decimal,
3941 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3942 the variables can also be restricted to IP address or MAC address.
3944 The format of the list is:
3945 type_attribute = [s|d|x|b|i|m]
3946 access_attribute = [a|r|o|c]
3947 attributes = type_attribute[access_attribute]
3948 entry = variable_name[:attributes]
3951 The type attributes are:
3952 s - String (default)
3955 b - Boolean ([1yYtT|0nNfF])
3959 The access attributes are:
3965 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3966 Define this to a list (string) to define the ".flags"
3967 environment variable in the default or embedded environment.
3969 - CONFIG_ENV_FLAGS_LIST_STATIC
3970 Define this to a list (string) to define validation that
3971 should be done if an entry is not found in the ".flags"
3972 environment variable. To override a setting in the static
3973 list, simply add an entry for the same variable name to the
3976 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3977 regular expression. This allows multiple variables to define the same
3978 flags without explicitly listing them for each variable.
3980 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3981 If defined, don't allow the -f switch to env set override variable
3984 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3985 This is set by OMAP boards for the max time that reset should
3986 be asserted. See doc/README.omap-reset-time for details on how
3987 the value can be calculated on a given board.
3990 If stdint.h is available with your toolchain you can define this
3991 option to enable it. You can provide option 'USE_STDINT=1' when
3992 building U-Boot to enable this.
3994 The following definitions that deal with the placement and management
3995 of environment data (variable area); in general, we support the
3996 following configurations:
3998 - CONFIG_BUILD_ENVCRC:
4000 Builds up envcrc with the target environment so that external utils
4001 may easily extract it and embed it in final U-Boot images.
4003 - CONFIG_ENV_IS_IN_FLASH:
4005 Define this if the environment is in flash memory.
4007 a) The environment occupies one whole flash sector, which is
4008 "embedded" in the text segment with the U-Boot code. This
4009 happens usually with "bottom boot sector" or "top boot
4010 sector" type flash chips, which have several smaller
4011 sectors at the start or the end. For instance, such a
4012 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4013 such a case you would place the environment in one of the
4014 4 kB sectors - with U-Boot code before and after it. With
4015 "top boot sector" type flash chips, you would put the
4016 environment in one of the last sectors, leaving a gap
4017 between U-Boot and the environment.
4019 - CONFIG_ENV_OFFSET:
4021 Offset of environment data (variable area) to the
4022 beginning of flash memory; for instance, with bottom boot
4023 type flash chips the second sector can be used: the offset
4024 for this sector is given here.
4026 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4030 This is just another way to specify the start address of
4031 the flash sector containing the environment (instead of
4034 - CONFIG_ENV_SECT_SIZE:
4036 Size of the sector containing the environment.
4039 b) Sometimes flash chips have few, equal sized, BIG sectors.
4040 In such a case you don't want to spend a whole sector for
4045 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4046 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4047 of this flash sector for the environment. This saves
4048 memory for the RAM copy of the environment.
4050 It may also save flash memory if you decide to use this
4051 when your environment is "embedded" within U-Boot code,
4052 since then the remainder of the flash sector could be used
4053 for U-Boot code. It should be pointed out that this is
4054 STRONGLY DISCOURAGED from a robustness point of view:
4055 updating the environment in flash makes it always
4056 necessary to erase the WHOLE sector. If something goes
4057 wrong before the contents has been restored from a copy in
4058 RAM, your target system will be dead.
4060 - CONFIG_ENV_ADDR_REDUND
4061 CONFIG_ENV_SIZE_REDUND
4063 These settings describe a second storage area used to hold
4064 a redundant copy of the environment data, so that there is
4065 a valid backup copy in case there is a power failure during
4066 a "saveenv" operation.
4068 BE CAREFUL! Any changes to the flash layout, and some changes to the
4069 source code will make it necessary to adapt <board>/u-boot.lds*
4073 - CONFIG_ENV_IS_IN_NVRAM:
4075 Define this if you have some non-volatile memory device
4076 (NVRAM, battery buffered SRAM) which you want to use for the
4082 These two #defines are used to determine the memory area you
4083 want to use for environment. It is assumed that this memory
4084 can just be read and written to, without any special
4087 BE CAREFUL! The first access to the environment happens quite early
4088 in U-Boot initialization (when we try to get the setting of for the
4089 console baudrate). You *MUST* have mapped your NVRAM area then, or
4092 Please note that even with NVRAM we still use a copy of the
4093 environment in RAM: we could work on NVRAM directly, but we want to
4094 keep settings there always unmodified except somebody uses "saveenv"
4095 to save the current settings.
4098 - CONFIG_ENV_IS_IN_EEPROM:
4100 Use this if you have an EEPROM or similar serial access
4101 device and a driver for it.
4103 - CONFIG_ENV_OFFSET:
4106 These two #defines specify the offset and size of the
4107 environment area within the total memory of your EEPROM.
4109 - CONFIG_SYS_I2C_EEPROM_ADDR:
4110 If defined, specified the chip address of the EEPROM device.
4111 The default address is zero.
4113 - CONFIG_SYS_I2C_EEPROM_BUS:
4114 If defined, specified the i2c bus of the EEPROM device.
4116 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4117 If defined, the number of bits used to address bytes in a
4118 single page in the EEPROM device. A 64 byte page, for example
4119 would require six bits.
4121 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4122 If defined, the number of milliseconds to delay between
4123 page writes. The default is zero milliseconds.
4125 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4126 The length in bytes of the EEPROM memory array address. Note
4127 that this is NOT the chip address length!
4129 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4130 EEPROM chips that implement "address overflow" are ones
4131 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4132 address and the extra bits end up in the "chip address" bit
4133 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4136 Note that we consider the length of the address field to
4137 still be one byte because the extra address bits are hidden
4138 in the chip address.
4140 - CONFIG_SYS_EEPROM_SIZE:
4141 The size in bytes of the EEPROM device.
4143 - CONFIG_ENV_EEPROM_IS_ON_I2C
4144 define this, if you have I2C and SPI activated, and your
4145 EEPROM, which holds the environment, is on the I2C bus.
4147 - CONFIG_I2C_ENV_EEPROM_BUS
4148 if you have an Environment on an EEPROM reached over
4149 I2C muxes, you can define here, how to reach this
4150 EEPROM. For example:
4152 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4154 EEPROM which holds the environment, is reached over
4155 a pca9547 i2c mux with address 0x70, channel 3.
4157 - CONFIG_ENV_IS_IN_DATAFLASH:
4159 Define this if you have a DataFlash memory device which you
4160 want to use for the environment.
4162 - CONFIG_ENV_OFFSET:
4166 These three #defines specify the offset and size of the
4167 environment area within the total memory of your DataFlash placed
4168 at the specified address.
4170 - CONFIG_ENV_IS_IN_SPI_FLASH:
4172 Define this if you have a SPI Flash memory device which you
4173 want to use for the environment.
4175 - CONFIG_ENV_OFFSET:
4178 These two #defines specify the offset and size of the
4179 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4180 aligned to an erase sector boundary.
4182 - CONFIG_ENV_SECT_SIZE:
4184 Define the SPI flash's sector size.
4186 - CONFIG_ENV_OFFSET_REDUND (optional):
4188 This setting describes a second storage area of CONFIG_ENV_SIZE
4189 size used to hold a redundant copy of the environment data, so
4190 that there is a valid backup copy in case there is a power failure
4191 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4192 aligned to an erase sector boundary.
4194 - CONFIG_ENV_SPI_BUS (optional):
4195 - CONFIG_ENV_SPI_CS (optional):
4197 Define the SPI bus and chip select. If not defined they will be 0.
4199 - CONFIG_ENV_SPI_MAX_HZ (optional):
4201 Define the SPI max work clock. If not defined then use 1MHz.
4203 - CONFIG_ENV_SPI_MODE (optional):
4205 Define the SPI work mode. If not defined then use SPI_MODE_3.
4207 - CONFIG_ENV_IS_IN_REMOTE:
4209 Define this if you have a remote memory space which you
4210 want to use for the local device's environment.
4215 These two #defines specify the address and size of the
4216 environment area within the remote memory space. The
4217 local device can get the environment from remote memory
4218 space by SRIO or PCIE links.
4220 BE CAREFUL! For some special cases, the local device can not use
4221 "saveenv" command. For example, the local device will get the
4222 environment stored in a remote NOR flash by SRIO or PCIE link,
4223 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4225 - CONFIG_ENV_IS_IN_NAND:
4227 Define this if you have a NAND device which you want to use
4228 for the environment.
4230 - CONFIG_ENV_OFFSET:
4233 These two #defines specify the offset and size of the environment
4234 area within the first NAND device. CONFIG_ENV_OFFSET must be
4235 aligned to an erase block boundary.
4237 - CONFIG_ENV_OFFSET_REDUND (optional):
4239 This setting describes a second storage area of CONFIG_ENV_SIZE
4240 size used to hold a redundant copy of the environment data, so
4241 that there is a valid backup copy in case there is a power failure
4242 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4243 aligned to an erase block boundary.
4245 - CONFIG_ENV_RANGE (optional):
4247 Specifies the length of the region in which the environment
4248 can be written. This should be a multiple of the NAND device's
4249 block size. Specifying a range with more erase blocks than
4250 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4251 the range to be avoided.
4253 - CONFIG_ENV_OFFSET_OOB (optional):
4255 Enables support for dynamically retrieving the offset of the
4256 environment from block zero's out-of-band data. The
4257 "nand env.oob" command can be used to record this offset.
4258 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4259 using CONFIG_ENV_OFFSET_OOB.
4261 - CONFIG_NAND_ENV_DST
4263 Defines address in RAM to which the nand_spl code should copy the
4264 environment. If redundant environment is used, it will be copied to
4265 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4267 - CONFIG_ENV_IS_IN_UBI:
4269 Define this if you have an UBI volume that you want to use for the
4270 environment. This has the benefit of wear-leveling the environment
4271 accesses, which is important on NAND.
4273 - CONFIG_ENV_UBI_PART:
4275 Define this to a string that is the mtd partition containing the UBI.
4277 - CONFIG_ENV_UBI_VOLUME:
4279 Define this to the name of the volume that you want to store the
4282 - CONFIG_ENV_UBI_VOLUME_REDUND:
4284 Define this to the name of another volume to store a second copy of
4285 the environment in. This will enable redundant environments in UBI.
4286 It is assumed that both volumes are in the same MTD partition.
4288 - CONFIG_UBI_SILENCE_MSG
4289 - CONFIG_UBIFS_SILENCE_MSG
4291 You will probably want to define these to avoid a really noisy system
4292 when storing the env in UBI.
4294 - CONFIG_ENV_IS_IN_FAT:
4295 Define this if you want to use the FAT file system for the environment.
4297 - FAT_ENV_INTERFACE:
4299 Define this to a string that is the name of the block device.
4301 - FAT_ENV_DEV_AND_PART:
4303 Define this to a string to specify the partition of the device. It can
4306 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4307 - "D:P": device D partition P. Error occurs if device D has no
4310 - "D" or "D:": device D partition 1 if device D has partition
4311 table, or the whole device D if has no partition
4313 - "D:auto": first partition in device D with bootable flag set.
4314 If none, first valid partition in device D. If no
4315 partition table then means device D.
4319 It's a string of the FAT file name. This file use to store the
4323 This should be defined. Otherwise it cannot save the environment file.
4325 - CONFIG_ENV_IS_IN_MMC:
4327 Define this if you have an MMC device which you want to use for the
4330 - CONFIG_SYS_MMC_ENV_DEV:
4332 Specifies which MMC device the environment is stored in.
4334 - CONFIG_SYS_MMC_ENV_PART (optional):
4336 Specifies which MMC partition the environment is stored in. If not
4337 set, defaults to partition 0, the user area. Common values might be
4338 1 (first MMC boot partition), 2 (second MMC boot partition).
4340 - CONFIG_ENV_OFFSET:
4343 These two #defines specify the offset and size of the environment
4344 area within the specified MMC device.
4346 If offset is positive (the usual case), it is treated as relative to
4347 the start of the MMC partition. If offset is negative, it is treated
4348 as relative to the end of the MMC partition. This can be useful if
4349 your board may be fitted with different MMC devices, which have
4350 different sizes for the MMC partitions, and you always want the
4351 environment placed at the very end of the partition, to leave the
4352 maximum possible space before it, to store other data.
4354 These two values are in units of bytes, but must be aligned to an
4355 MMC sector boundary.
4357 - CONFIG_ENV_OFFSET_REDUND (optional):
4359 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4360 hold a redundant copy of the environment data. This provides a
4361 valid backup copy in case the other copy is corrupted, e.g. due
4362 to a power failure during a "saveenv" operation.
4364 This value may also be positive or negative; this is handled in the
4365 same way as CONFIG_ENV_OFFSET.
4367 This value is also in units of bytes, but must also be aligned to
4368 an MMC sector boundary.
4370 - CONFIG_ENV_SIZE_REDUND (optional):
4372 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4373 set. If this value is set, it must be set to the same value as
4376 - CONFIG_SYS_SPI_INIT_OFFSET
4378 Defines offset to the initial SPI buffer area in DPRAM. The
4379 area is used at an early stage (ROM part) if the environment
4380 is configured to reside in the SPI EEPROM: We need a 520 byte
4381 scratch DPRAM area. It is used between the two initialization
4382 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4383 to be a good choice since it makes it far enough from the
4384 start of the data area as well as from the stack pointer.
4386 Please note that the environment is read-only until the monitor
4387 has been relocated to RAM and a RAM copy of the environment has been
4388 created; also, when using EEPROM you will have to use getenv_f()
4389 until then to read environment variables.
4391 The environment is protected by a CRC32 checksum. Before the monitor
4392 is relocated into RAM, as a result of a bad CRC you will be working
4393 with the compiled-in default environment - *silently*!!! [This is
4394 necessary, because the first environment variable we need is the
4395 "baudrate" setting for the console - if we have a bad CRC, we don't
4396 have any device yet where we could complain.]
4398 Note: once the monitor has been relocated, then it will complain if
4399 the default environment is used; a new CRC is computed as soon as you
4400 use the "saveenv" command to store a valid environment.
4402 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4403 Echo the inverted Ethernet link state to the fault LED.
4405 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4406 also needs to be defined.
4408 - CONFIG_SYS_FAULT_MII_ADDR:
4409 MII address of the PHY to check for the Ethernet link state.
4411 - CONFIG_NS16550_MIN_FUNCTIONS:
4412 Define this if you desire to only have use of the NS16550_init
4413 and NS16550_putc functions for the serial driver located at
4414 drivers/serial/ns16550.c. This option is useful for saving
4415 space for already greatly restricted images, including but not
4416 limited to NAND_SPL configurations.
4418 - CONFIG_DISPLAY_BOARDINFO
4419 Display information about the board that U-Boot is running on
4420 when U-Boot starts up. The board function checkboard() is called
4423 - CONFIG_DISPLAY_BOARDINFO_LATE
4424 Similar to the previous option, but display this information
4425 later, once stdio is running and output goes to the LCD, if
4428 - CONFIG_BOARD_SIZE_LIMIT:
4429 Maximum size of the U-Boot image. When defined, the
4430 build system checks that the actual size does not
4433 Low Level (hardware related) configuration options:
4434 ---------------------------------------------------
4436 - CONFIG_SYS_CACHELINE_SIZE:
4437 Cache Line Size of the CPU.
4439 - CONFIG_SYS_DEFAULT_IMMR:
4440 Default address of the IMMR after system reset.
4442 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4443 and RPXsuper) to be able to adjust the position of
4444 the IMMR register after a reset.
4446 - CONFIG_SYS_CCSRBAR_DEFAULT:
4447 Default (power-on reset) physical address of CCSR on Freescale
4450 - CONFIG_SYS_CCSRBAR:
4451 Virtual address of CCSR. On a 32-bit build, this is typically
4452 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4454 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4455 for cross-platform code that uses that macro instead.
4457 - CONFIG_SYS_CCSRBAR_PHYS:
4458 Physical address of CCSR. CCSR can be relocated to a new
4459 physical address, if desired. In this case, this macro should
4460 be set to that address. Otherwise, it should be set to the
4461 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4462 is typically relocated on 36-bit builds. It is recommended
4463 that this macro be defined via the _HIGH and _LOW macros:
4465 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4466 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4468 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4469 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4470 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4471 used in assembly code, so it must not contain typecasts or
4472 integer size suffixes (e.g. "ULL").
4474 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4475 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4476 used in assembly code, so it must not contain typecasts or
4477 integer size suffixes (e.g. "ULL").
4479 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4480 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4481 forced to a value that ensures that CCSR is not relocated.
4483 - Floppy Disk Support:
4484 CONFIG_SYS_FDC_DRIVE_NUMBER
4486 the default drive number (default value 0)
4488 CONFIG_SYS_ISA_IO_STRIDE
4490 defines the spacing between FDC chipset registers
4493 CONFIG_SYS_ISA_IO_OFFSET
4495 defines the offset of register from address. It
4496 depends on which part of the data bus is connected to
4497 the FDC chipset. (default value 0)
4499 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4500 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4503 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4504 fdc_hw_init() is called at the beginning of the FDC
4505 setup. fdc_hw_init() must be provided by the board
4506 source code. It is used to make hardware-dependent
4510 Most IDE controllers were designed to be connected with PCI
4511 interface. Only few of them were designed for AHB interface.
4512 When software is doing ATA command and data transfer to
4513 IDE devices through IDE-AHB controller, some additional
4514 registers accessing to these kind of IDE-AHB controller
4517 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4518 DO NOT CHANGE unless you know exactly what you're
4519 doing! (11-4) [MPC8xx/82xx systems only]
4521 - CONFIG_SYS_INIT_RAM_ADDR:
4523 Start address of memory area that can be used for
4524 initial data and stack; please note that this must be
4525 writable memory that is working WITHOUT special
4526 initialization, i. e. you CANNOT use normal RAM which
4527 will become available only after programming the
4528 memory controller and running certain initialization
4531 U-Boot uses the following memory types:
4532 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4533 - MPC824X: data cache
4534 - PPC4xx: data cache
4536 - CONFIG_SYS_GBL_DATA_OFFSET:
4538 Offset of the initial data structure in the memory
4539 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4540 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4541 data is located at the end of the available space
4542 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4543 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4544 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4545 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4548 On the MPC824X (or other systems that use the data
4549 cache for initial memory) the address chosen for
4550 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4551 point to an otherwise UNUSED address space between
4552 the top of RAM and the start of the PCI space.
4554 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4556 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4558 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4560 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4562 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4564 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4566 - CONFIG_SYS_OR_TIMING_SDRAM:
4569 - CONFIG_SYS_MAMR_PTA:
4570 periodic timer for refresh
4572 - CONFIG_SYS_DER: Debug Event Register (37-47)
4574 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4575 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4576 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4577 CONFIG_SYS_BR1_PRELIM:
4578 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4580 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4581 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4582 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4583 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4585 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4586 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4587 Machine Mode Register and Memory Periodic Timer
4588 Prescaler definitions (SDRAM timing)
4590 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4591 enable I2C microcode relocation patch (MPC8xx);
4592 define relocation offset in DPRAM [DSP2]
4594 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4595 enable SMC microcode relocation patch (MPC8xx);
4596 define relocation offset in DPRAM [SMC1]
4598 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4599 enable SPI microcode relocation patch (MPC8xx);
4600 define relocation offset in DPRAM [SCC4]
4602 - CONFIG_SYS_USE_OSCCLK:
4603 Use OSCM clock mode on MBX8xx board. Be careful,
4604 wrong setting might damage your board. Read
4605 doc/README.MBX before setting this variable!
4607 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4608 Offset of the bootmode word in DPRAM used by post
4609 (Power On Self Tests). This definition overrides
4610 #define'd default value in commproc.h resp.
4613 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4614 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4615 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4616 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4617 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4618 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4619 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4620 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4621 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4623 - CONFIG_PCI_DISABLE_PCIE:
4624 Disable PCI-Express on systems where it is supported but not
4627 - CONFIG_PCI_ENUM_ONLY
4628 Only scan through and get the devices on the buses.
4629 Don't do any setup work, presumably because someone or
4630 something has already done it, and we don't need to do it
4631 a second time. Useful for platforms that are pre-booted
4632 by coreboot or similar.
4634 - CONFIG_PCI_INDIRECT_BRIDGE:
4635 Enable support for indirect PCI bridges.
4638 Chip has SRIO or not
4641 Board has SRIO 1 port available
4644 Board has SRIO 2 port available
4646 - CONFIG_SRIO_PCIE_BOOT_MASTER
4647 Board can support master function for Boot from SRIO and PCIE
4649 - CONFIG_SYS_SRIOn_MEM_VIRT:
4650 Virtual Address of SRIO port 'n' memory region
4652 - CONFIG_SYS_SRIOn_MEM_PHYS:
4653 Physical Address of SRIO port 'n' memory region
4655 - CONFIG_SYS_SRIOn_MEM_SIZE:
4656 Size of SRIO port 'n' memory region
4658 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4659 Defined to tell the NAND controller that the NAND chip is using
4661 Not all NAND drivers use this symbol.
4662 Example of drivers that use it:
4663 - drivers/mtd/nand/ndfc.c
4664 - drivers/mtd/nand/mxc_nand.c
4666 - CONFIG_SYS_NDFC_EBC0_CFG
4667 Sets the EBC0_CFG register for the NDFC. If not defined
4668 a default value will be used.
4671 Get DDR timing information from an I2C EEPROM. Common
4672 with pluggable memory modules such as SODIMMs
4675 I2C address of the SPD EEPROM
4677 - CONFIG_SYS_SPD_BUS_NUM
4678 If SPD EEPROM is on an I2C bus other than the first
4679 one, specify here. Note that the value must resolve
4680 to something your driver can deal with.
4682 - CONFIG_SYS_DDR_RAW_TIMING
4683 Get DDR timing information from other than SPD. Common with
4684 soldered DDR chips onboard without SPD. DDR raw timing
4685 parameters are extracted from datasheet and hard-coded into
4686 header files or board specific files.
4688 - CONFIG_FSL_DDR_INTERACTIVE
4689 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4691 - CONFIG_FSL_DDR_SYNC_REFRESH
4692 Enable sync of refresh for multiple controllers.
4694 - CONFIG_FSL_DDR_BIST
4695 Enable built-in memory test for Freescale DDR controllers.
4697 - CONFIG_SYS_83XX_DDR_USES_CS0
4698 Only for 83xx systems. If specified, then DDR should
4699 be configured using CS0 and CS1 instead of CS2 and CS3.
4701 - CONFIG_ETHER_ON_FEC[12]
4702 Define to enable FEC[12] on a 8xx series processor.
4704 - CONFIG_FEC[12]_PHY
4705 Define to the hardcoded PHY address which corresponds
4706 to the given FEC; i. e.
4707 #define CONFIG_FEC1_PHY 4
4708 means that the PHY with address 4 is connected to FEC1
4710 When set to -1, means to probe for first available.
4712 - CONFIG_FEC[12]_PHY_NORXERR
4713 The PHY does not have a RXERR line (RMII only).
4714 (so program the FEC to ignore it).
4717 Enable RMII mode for all FECs.
4718 Note that this is a global option, we can't
4719 have one FEC in standard MII mode and another in RMII mode.
4721 - CONFIG_CRC32_VERIFY
4722 Add a verify option to the crc32 command.
4725 => crc32 -v <address> <count> <crc32>
4727 Where address/count indicate a memory area
4728 and crc32 is the correct crc32 which the
4732 Add the "loopw" memory command. This only takes effect if
4733 the memory commands are activated globally (CONFIG_CMD_MEM).
4736 Add the "mdc" and "mwc" memory commands. These are cyclic
4741 This command will print 4 bytes (10,11,12,13) each 500 ms.
4743 => mwc.l 100 12345678 10
4744 This command will write 12345678 to address 100 all 10 ms.
4746 This only takes effect if the memory commands are activated
4747 globally (CONFIG_CMD_MEM).
4749 - CONFIG_SKIP_LOWLEVEL_INIT
4750 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4751 low level initializations (like setting up the memory
4752 controller) are omitted and/or U-Boot does not
4753 relocate itself into RAM.
4755 Normally this variable MUST NOT be defined. The only
4756 exception is when U-Boot is loaded (to RAM) by some
4757 other boot loader or by a debugger which performs
4758 these initializations itself.
4760 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4761 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4762 to be skipped. The normal CP15 init (such as enabling the
4763 instruction cache) is still performed.
4766 Modifies the behaviour of start.S when compiling a loader
4767 that is executed before the actual U-Boot. E.g. when
4768 compiling a NAND SPL.
4771 Modifies the behaviour of start.S when compiling a loader
4772 that is executed after the SPL and before the actual U-Boot.
4773 It is loaded by the SPL.
4775 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4776 Only for 85xx systems. If this variable is specified, the section
4777 .resetvec is not kept and the section .bootpg is placed in the
4778 previous 4k of the .text section.
4780 - CONFIG_ARCH_MAP_SYSMEM
4781 Generally U-Boot (and in particular the md command) uses
4782 effective address. It is therefore not necessary to regard
4783 U-Boot address as virtual addresses that need to be translated
4784 to physical addresses. However, sandbox requires this, since
4785 it maintains its own little RAM buffer which contains all
4786 addressable memory. This option causes some memory accesses
4787 to be mapped through map_sysmem() / unmap_sysmem().
4789 - CONFIG_USE_ARCH_MEMCPY
4790 CONFIG_USE_ARCH_MEMSET
4791 If these options are used a optimized version of memcpy/memset will
4792 be used if available. These functions may be faster under some
4793 conditions but may increase the binary size.
4795 - CONFIG_X86_RESET_VECTOR
4796 If defined, the x86 reset vector code is included. This is not
4797 needed when U-Boot is running from Coreboot.
4800 Defines the MPU clock speed (in MHz).
4802 NOTE : currently only supported on AM335x platforms.
4804 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4805 Enables the RTC32K OSC on AM33xx based plattforms
4807 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4808 Option to disable subpage write in NAND driver
4809 driver that uses this:
4810 drivers/mtd/nand/davinci_nand.c
4812 Freescale QE/FMAN Firmware Support:
4813 -----------------------------------
4815 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4816 loading of "firmware", which is encoded in the QE firmware binary format.
4817 This firmware often needs to be loaded during U-Boot booting, so macros
4818 are used to identify the storage device (NOR flash, SPI, etc) and the address
4821 - CONFIG_SYS_FMAN_FW_ADDR
4822 The address in the storage device where the FMAN microcode is located. The
4823 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4826 - CONFIG_SYS_QE_FW_ADDR
4827 The address in the storage device where the QE microcode is located. The
4828 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4831 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4832 The maximum possible size of the firmware. The firmware binary format
4833 has a field that specifies the actual size of the firmware, but it
4834 might not be possible to read any part of the firmware unless some
4835 local storage is allocated to hold the entire firmware first.
4837 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4838 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4839 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4840 virtual address in NOR flash.
4842 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4843 Specifies that QE/FMAN firmware is located in NAND flash.
4844 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4846 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4847 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4848 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4850 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4851 Specifies that QE/FMAN firmware is located on the primary SPI
4852 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4854 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4855 Specifies that QE/FMAN firmware is located in the remote (master)
4856 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4857 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4858 window->master inbound window->master LAW->the ucode address in
4859 master's memory space.
4861 Freescale Layerscape Management Complex Firmware Support:
4862 ---------------------------------------------------------
4863 The Freescale Layerscape Management Complex (MC) supports the loading of
4865 This firmware often needs to be loaded during U-Boot booting, so macros
4866 are used to identify the storage device (NOR flash, SPI, etc) and the address
4869 - CONFIG_FSL_MC_ENET
4870 Enable the MC driver for Layerscape SoCs.
4872 - CONFIG_SYS_LS_MC_FW_ADDR
4873 The address in the storage device where the firmware is located. The
4874 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4877 - CONFIG_SYS_LS_MC_FW_LENGTH
4878 The maximum possible size of the firmware. The firmware binary format
4879 has a field that specifies the actual size of the firmware, but it
4880 might not be possible to read any part of the firmware unless some
4881 local storage is allocated to hold the entire firmware first.
4883 - CONFIG_SYS_LS_MC_FW_IN_NOR
4884 Specifies that MC firmware is located in NOR flash, mapped as
4885 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4886 virtual address in NOR flash.
4888 Freescale Layerscape Debug Server Support:
4889 -------------------------------------------
4890 The Freescale Layerscape Debug Server Support supports the loading of
4891 "Debug Server firmware" and triggering SP boot-rom.
4892 This firmware often needs to be loaded during U-Boot booting.
4894 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4895 Define alignment of reserved memory MC requires
4900 In order to achieve reproducible builds, timestamps used in the U-Boot build
4901 process have to be set to a fixed value.
4903 This is done using the SOURCE_DATE_EPOCH environment variable.
4904 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4905 option for U-Boot or an environment variable in U-Boot.
4907 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4909 Building the Software:
4910 ======================
4912 Building U-Boot has been tested in several native build environments
4913 and in many different cross environments. Of course we cannot support
4914 all possibly existing versions of cross development tools in all
4915 (potentially obsolete) versions. In case of tool chain problems we
4916 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4917 which is extensively used to build and test U-Boot.
4919 If you are not using a native environment, it is assumed that you
4920 have GNU cross compiling tools available in your path. In this case,
4921 you must set the environment variable CROSS_COMPILE in your shell.
4922 Note that no changes to the Makefile or any other source files are
4923 necessary. For example using the ELDK on a 4xx CPU, please enter:
4925 $ CROSS_COMPILE=ppc_4xx-
4926 $ export CROSS_COMPILE
4928 Note: If you wish to generate Windows versions of the utilities in
4929 the tools directory you can use the MinGW toolchain
4930 (http://www.mingw.org). Set your HOST tools to the MinGW
4931 toolchain and execute 'make tools'. For example:
4933 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4935 Binaries such as tools/mkimage.exe will be created which can
4936 be executed on computers running Windows.
4938 U-Boot is intended to be simple to build. After installing the
4939 sources you must configure U-Boot for one specific board type. This
4944 where "NAME_defconfig" is the name of one of the existing configu-
4945 rations; see boards.cfg for supported names.
4947 Note: for some board special configuration names may exist; check if
4948 additional information is available from the board vendor; for
4949 instance, the TQM823L systems are available without (standard)
4950 or with LCD support. You can select such additional "features"
4951 when choosing the configuration, i. e.
4953 make TQM823L_defconfig
4954 - will configure for a plain TQM823L, i. e. no LCD support
4956 make TQM823L_LCD_defconfig
4957 - will configure for a TQM823L with U-Boot console on LCD
4962 Finally, type "make all", and you should get some working U-Boot
4963 images ready for download to / installation on your system:
4965 - "u-boot.bin" is a raw binary image
4966 - "u-boot" is an image in ELF binary format
4967 - "u-boot.srec" is in Motorola S-Record format
4969 By default the build is performed locally and the objects are saved
4970 in the source directory. One of the two methods can be used to change
4971 this behavior and build U-Boot to some external directory:
4973 1. Add O= to the make command line invocations:
4975 make O=/tmp/build distclean
4976 make O=/tmp/build NAME_defconfig
4977 make O=/tmp/build all
4979 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4981 export KBUILD_OUTPUT=/tmp/build
4986 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4990 Please be aware that the Makefiles assume you are using GNU make, so
4991 for instance on NetBSD you might need to use "gmake" instead of
4995 If the system board that you have is not listed, then you will need
4996 to port U-Boot to your hardware platform. To do this, follow these
4999 1. Create a new directory to hold your board specific code. Add any
5000 files you need. In your board directory, you will need at least
5001 the "Makefile" and a "<board>.c".
5002 2. Create a new configuration file "include/configs/<board>.h" for
5004 3. If you're porting U-Boot to a new CPU, then also create a new
5005 directory to hold your CPU specific code. Add any files you need.
5006 4. Run "make <board>_defconfig" with your new name.
5007 5. Type "make", and you should get a working "u-boot.srec" file
5008 to be installed on your target system.
5009 6. Debug and solve any problems that might arise.
5010 [Of course, this last step is much harder than it sounds.]
5013 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5014 ==============================================================
5016 If you have modified U-Boot sources (for instance added a new board
5017 or support for new devices, a new CPU, etc.) you are expected to
5018 provide feedback to the other developers. The feedback normally takes
5019 the form of a "patch", i. e. a context diff against a certain (latest
5020 official or latest in the git repository) version of U-Boot sources.
5022 But before you submit such a patch, please verify that your modifi-
5023 cation did not break existing code. At least make sure that *ALL* of
5024 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5025 just run the buildman script (tools/buildman/buildman), which will
5026 configure and build U-Boot for ALL supported system. Be warned, this
5027 will take a while. Please see the buildman README, or run 'buildman -H'
5031 See also "U-Boot Porting Guide" below.
5034 Monitor Commands - Overview:
5035 ============================
5037 go - start application at address 'addr'
5038 run - run commands in an environment variable
5039 bootm - boot application image from memory
5040 bootp - boot image via network using BootP/TFTP protocol
5041 bootz - boot zImage from memory
5042 tftpboot- boot image via network using TFTP protocol
5043 and env variables "ipaddr" and "serverip"
5044 (and eventually "gatewayip")
5045 tftpput - upload a file via network using TFTP protocol
5046 rarpboot- boot image via network using RARP/TFTP protocol
5047 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5048 loads - load S-Record file over serial line
5049 loadb - load binary file over serial line (kermit mode)
5051 mm - memory modify (auto-incrementing)
5052 nm - memory modify (constant address)
5053 mw - memory write (fill)
5055 cmp - memory compare
5056 crc32 - checksum calculation
5057 i2c - I2C sub-system
5058 sspi - SPI utility commands
5059 base - print or set address offset
5060 printenv- print environment variables
5061 setenv - set environment variables
5062 saveenv - save environment variables to persistent storage
5063 protect - enable or disable FLASH write protection
5064 erase - erase FLASH memory
5065 flinfo - print FLASH memory information
5066 nand - NAND memory operations (see doc/README.nand)
5067 bdinfo - print Board Info structure
5068 iminfo - print header information for application image
5069 coninfo - print console devices and informations
5070 ide - IDE sub-system
5071 loop - infinite loop on address range
5072 loopw - infinite write loop on address range
5073 mtest - simple RAM test
5074 icache - enable or disable instruction cache
5075 dcache - enable or disable data cache
5076 reset - Perform RESET of the CPU
5077 echo - echo args to console
5078 version - print monitor version
5079 help - print online help
5080 ? - alias for 'help'
5083 Monitor Commands - Detailed Description:
5084 ========================================
5088 For now: just type "help <command>".
5091 Environment Variables:
5092 ======================
5094 U-Boot supports user configuration using Environment Variables which
5095 can be made persistent by saving to Flash memory.
5097 Environment Variables are set using "setenv", printed using
5098 "printenv", and saved to Flash using "saveenv". Using "setenv"
5099 without a value can be used to delete a variable from the
5100 environment. As long as you don't save the environment you are
5101 working with an in-memory copy. In case the Flash area containing the
5102 environment is erased by accident, a default environment is provided.
5104 Some configuration options can be set using Environment Variables.
5106 List of environment variables (most likely not complete):
5108 baudrate - see CONFIG_BAUDRATE
5110 bootdelay - see CONFIG_BOOTDELAY
5112 bootcmd - see CONFIG_BOOTCOMMAND
5114 bootargs - Boot arguments when booting an RTOS image
5116 bootfile - Name of the image to load with TFTP
5118 bootm_low - Memory range available for image processing in the bootm
5119 command can be restricted. This variable is given as
5120 a hexadecimal number and defines lowest address allowed
5121 for use by the bootm command. See also "bootm_size"
5122 environment variable. Address defined by "bootm_low" is
5123 also the base of the initial memory mapping for the Linux
5124 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5127 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5128 This variable is given as a hexadecimal number and it
5129 defines the size of the memory region starting at base
5130 address bootm_low that is accessible by the Linux kernel
5131 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5132 as the default value if it is defined, and bootm_size is
5135 bootm_size - Memory range available for image processing in the bootm
5136 command can be restricted. This variable is given as
5137 a hexadecimal number and defines the size of the region
5138 allowed for use by the bootm command. See also "bootm_low"
5139 environment variable.
5141 updatefile - Location of the software update file on a TFTP server, used
5142 by the automatic software update feature. Please refer to
5143 documentation in doc/README.update for more details.
5145 autoload - if set to "no" (any string beginning with 'n'),
5146 "bootp" will just load perform a lookup of the
5147 configuration from the BOOTP server, but not try to
5148 load any image using TFTP
5150 autostart - if set to "yes", an image loaded using the "bootp",
5151 "rarpboot", "tftpboot" or "diskboot" commands will
5152 be automatically started (by internally calling
5155 If set to "no", a standalone image passed to the
5156 "bootm" command will be copied to the load address
5157 (and eventually uncompressed), but NOT be started.
5158 This can be used to load and uncompress arbitrary
5161 fdt_high - if set this restricts the maximum address that the
5162 flattened device tree will be copied into upon boot.
5163 For example, if you have a system with 1 GB memory
5164 at physical address 0x10000000, while Linux kernel
5165 only recognizes the first 704 MB as low memory, you
5166 may need to set fdt_high as 0x3C000000 to have the
5167 device tree blob be copied to the maximum address
5168 of the 704 MB low memory, so that Linux kernel can
5169 access it during the boot procedure.
5171 If this is set to the special value 0xFFFFFFFF then
5172 the fdt will not be copied at all on boot. For this
5173 to work it must reside in writable memory, have
5174 sufficient padding on the end of it for u-boot to
5175 add the information it needs into it, and the memory
5176 must be accessible by the kernel.
5178 fdtcontroladdr- if set this is the address of the control flattened
5179 device tree used by U-Boot when CONFIG_OF_CONTROL is
5182 i2cfast - (PPC405GP|PPC405EP only)
5183 if set to 'y' configures Linux I2C driver for fast
5184 mode (400kHZ). This environment variable is used in
5185 initialization code. So, for changes to be effective
5186 it must be saved and board must be reset.
5188 initrd_high - restrict positioning of initrd images:
5189 If this variable is not set, initrd images will be
5190 copied to the highest possible address in RAM; this
5191 is usually what you want since it allows for
5192 maximum initrd size. If for some reason you want to
5193 make sure that the initrd image is loaded below the
5194 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5195 variable to a value of "no" or "off" or "0".
5196 Alternatively, you can set it to a maximum upper
5197 address to use (U-Boot will still check that it
5198 does not overwrite the U-Boot stack and data).
5200 For instance, when you have a system with 16 MB
5201 RAM, and want to reserve 4 MB from use by Linux,
5202 you can do this by adding "mem=12M" to the value of
5203 the "bootargs" variable. However, now you must make
5204 sure that the initrd image is placed in the first
5205 12 MB as well - this can be done with
5207 setenv initrd_high 00c00000
5209 If you set initrd_high to 0xFFFFFFFF, this is an
5210 indication to U-Boot that all addresses are legal
5211 for the Linux kernel, including addresses in flash
5212 memory. In this case U-Boot will NOT COPY the
5213 ramdisk at all. This may be useful to reduce the
5214 boot time on your system, but requires that this
5215 feature is supported by your Linux kernel.
5217 ipaddr - IP address; needed for tftpboot command
5219 loadaddr - Default load address for commands like "bootp",
5220 "rarpboot", "tftpboot", "loadb" or "diskboot"
5222 loads_echo - see CONFIG_LOADS_ECHO
5224 serverip - TFTP server IP address; needed for tftpboot command
5226 bootretry - see CONFIG_BOOT_RETRY_TIME
5228 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5230 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5232 ethprime - controls which interface is used first.
5234 ethact - controls which interface is currently active.
5235 For example you can do the following
5237 => setenv ethact FEC
5238 => ping 192.168.0.1 # traffic sent on FEC
5239 => setenv ethact SCC
5240 => ping 10.0.0.1 # traffic sent on SCC
5242 ethrotate - When set to "no" U-Boot does not go through all
5243 available network interfaces.
5244 It just stays at the currently selected interface.
5246 netretry - When set to "no" each network operation will
5247 either succeed or fail without retrying.
5248 When set to "once" the network operation will
5249 fail when all the available network interfaces
5250 are tried once without success.
5251 Useful on scripts which control the retry operation
5254 npe_ucode - set load address for the NPE microcode
5256 silent_linux - If set then Linux will be told to boot silently, by
5257 changing the console to be empty. If "yes" it will be
5258 made silent. If "no" it will not be made silent. If
5259 unset, then it will be made silent if the U-Boot console
5262 tftpsrcp - If this is set, the value is used for TFTP's
5265 tftpdstp - If this is set, the value is used for TFTP's UDP
5266 destination port instead of the Well Know Port 69.
5268 tftpblocksize - Block size to use for TFTP transfers; if not set,
5269 we use the TFTP server's default block size
5271 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5272 seconds, minimum value is 1000 = 1 second). Defines
5273 when a packet is considered to be lost so it has to
5274 be retransmitted. The default is 5000 = 5 seconds.
5275 Lowering this value may make downloads succeed
5276 faster in networks with high packet loss rates or
5277 with unreliable TFTP servers.
5279 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5280 unit, minimum value = 0). Defines how many timeouts
5281 can happen during a single file transfer before that
5282 transfer is aborted. The default is 10, and 0 means
5283 'no timeouts allowed'. Increasing this value may help
5284 downloads succeed with high packet loss rates, or with
5285 unreliable TFTP servers or client hardware.
5287 vlan - When set to a value < 4095 the traffic over
5288 Ethernet is encapsulated/received over 802.1q
5291 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5292 Unsigned value, in milliseconds. If not set, the period will
5293 be either the default (28000), or a value based on
5294 CONFIG_NET_RETRY_COUNT, if defined. This value has
5295 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5297 The following image location variables contain the location of images
5298 used in booting. The "Image" column gives the role of the image and is
5299 not an environment variable name. The other columns are environment
5300 variable names. "File Name" gives the name of the file on a TFTP
5301 server, "RAM Address" gives the location in RAM the image will be
5302 loaded to, and "Flash Location" gives the image's address in NOR
5303 flash or offset in NAND flash.
5305 *Note* - these variables don't have to be defined for all boards, some
5306 boards currently use other variables for these purposes, and some
5307 boards use these variables for other purposes.
5309 Image File Name RAM Address Flash Location
5310 ----- --------- ----------- --------------
5311 u-boot u-boot u-boot_addr_r u-boot_addr
5312 Linux kernel bootfile kernel_addr_r kernel_addr
5313 device tree blob fdtfile fdt_addr_r fdt_addr
5314 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5316 The following environment variables may be used and automatically
5317 updated by the network boot commands ("bootp" and "rarpboot"),
5318 depending the information provided by your boot server:
5320 bootfile - see above
5321 dnsip - IP address of your Domain Name Server
5322 dnsip2 - IP address of your secondary Domain Name Server
5323 gatewayip - IP address of the Gateway (Router) to use
5324 hostname - Target hostname
5326 netmask - Subnet Mask
5327 rootpath - Pathname of the root filesystem on the NFS server
5328 serverip - see above
5331 There are two special Environment Variables:
5333 serial# - contains hardware identification information such
5334 as type string and/or serial number
5335 ethaddr - Ethernet address
5337 These variables can be set only once (usually during manufacturing of
5338 the board). U-Boot refuses to delete or overwrite these variables
5339 once they have been set once.
5342 Further special Environment Variables:
5344 ver - Contains the U-Boot version string as printed
5345 with the "version" command. This variable is
5346 readonly (see CONFIG_VERSION_VARIABLE).
5349 Please note that changes to some configuration parameters may take
5350 only effect after the next boot (yes, that's just like Windoze :-).
5353 Callback functions for environment variables:
5354 ---------------------------------------------
5356 For some environment variables, the behavior of u-boot needs to change
5357 when their values are changed. This functionality allows functions to
5358 be associated with arbitrary variables. On creation, overwrite, or
5359 deletion, the callback will provide the opportunity for some side
5360 effect to happen or for the change to be rejected.
5362 The callbacks are named and associated with a function using the
5363 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5365 These callbacks are associated with variables in one of two ways. The
5366 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5367 in the board configuration to a string that defines a list of
5368 associations. The list must be in the following format:
5370 entry = variable_name[:callback_name]
5373 If the callback name is not specified, then the callback is deleted.
5374 Spaces are also allowed anywhere in the list.
5376 Callbacks can also be associated by defining the ".callbacks" variable
5377 with the same list format above. Any association in ".callbacks" will
5378 override any association in the static list. You can define
5379 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5380 ".callbacks" environment variable in the default or embedded environment.
5382 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5383 regular expression. This allows multiple variables to be connected to
5384 the same callback without explicitly listing them all out.
5387 Command Line Parsing:
5388 =====================
5390 There are two different command line parsers available with U-Boot:
5391 the old "simple" one, and the much more powerful "hush" shell:
5393 Old, simple command line parser:
5394 --------------------------------
5396 - supports environment variables (through setenv / saveenv commands)
5397 - several commands on one line, separated by ';'
5398 - variable substitution using "... ${name} ..." syntax
5399 - special characters ('$', ';') can be escaped by prefixing with '\',
5401 setenv bootcmd bootm \${address}
5402 - You can also escape text by enclosing in single apostrophes, for example:
5403 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5408 - similar to Bourne shell, with control structures like
5409 if...then...else...fi, for...do...done; while...do...done,
5410 until...do...done, ...
5411 - supports environment ("global") variables (through setenv / saveenv
5412 commands) and local shell variables (through standard shell syntax
5413 "name=value"); only environment variables can be used with "run"
5419 (1) If a command line (or an environment variable executed by a "run"
5420 command) contains several commands separated by semicolon, and
5421 one of these commands fails, then the remaining commands will be
5424 (2) If you execute several variables with one call to run (i. e.
5425 calling run with a list of variables as arguments), any failing
5426 command will cause "run" to terminate, i. e. the remaining
5427 variables are not executed.
5429 Note for Redundant Ethernet Interfaces:
5430 =======================================
5432 Some boards come with redundant Ethernet interfaces; U-Boot supports
5433 such configurations and is capable of automatic selection of a
5434 "working" interface when needed. MAC assignment works as follows:
5436 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5437 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5438 "eth1addr" (=>eth1), "eth2addr", ...
5440 If the network interface stores some valid MAC address (for instance
5441 in SROM), this is used as default address if there is NO correspon-
5442 ding setting in the environment; if the corresponding environment
5443 variable is set, this overrides the settings in the card; that means:
5445 o If the SROM has a valid MAC address, and there is no address in the
5446 environment, the SROM's address is used.
5448 o If there is no valid address in the SROM, and a definition in the
5449 environment exists, then the value from the environment variable is
5452 o If both the SROM and the environment contain a MAC address, and
5453 both addresses are the same, this MAC address is used.
5455 o If both the SROM and the environment contain a MAC address, and the
5456 addresses differ, the value from the environment is used and a
5459 o If neither SROM nor the environment contain a MAC address, an error
5460 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5461 a random, locally-assigned MAC is used.
5463 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5464 will be programmed into hardware as part of the initialization process. This
5465 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5466 The naming convention is as follows:
5467 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5472 U-Boot is capable of booting (and performing other auxiliary operations on)
5473 images in two formats:
5475 New uImage format (FIT)
5476 -----------------------
5478 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5479 to Flattened Device Tree). It allows the use of images with multiple
5480 components (several kernels, ramdisks, etc.), with contents protected by
5481 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5487 Old image format is based on binary files which can be basically anything,
5488 preceded by a special header; see the definitions in include/image.h for
5489 details; basically, the header defines the following image properties:
5491 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5492 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5493 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5494 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5496 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5497 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5498 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5499 * Compression Type (uncompressed, gzip, bzip2)
5505 The header is marked by a special Magic Number, and both the header
5506 and the data portions of the image are secured against corruption by
5513 Although U-Boot should support any OS or standalone application
5514 easily, the main focus has always been on Linux during the design of
5517 U-Boot includes many features that so far have been part of some
5518 special "boot loader" code within the Linux kernel. Also, any
5519 "initrd" images to be used are no longer part of one big Linux image;
5520 instead, kernel and "initrd" are separate images. This implementation
5521 serves several purposes:
5523 - the same features can be used for other OS or standalone
5524 applications (for instance: using compressed images to reduce the
5525 Flash memory footprint)
5527 - it becomes much easier to port new Linux kernel versions because
5528 lots of low-level, hardware dependent stuff are done by U-Boot
5530 - the same Linux kernel image can now be used with different "initrd"
5531 images; of course this also means that different kernel images can
5532 be run with the same "initrd". This makes testing easier (you don't
5533 have to build a new "zImage.initrd" Linux image when you just
5534 change a file in your "initrd"). Also, a field-upgrade of the
5535 software is easier now.
5541 Porting Linux to U-Boot based systems:
5542 ---------------------------------------
5544 U-Boot cannot save you from doing all the necessary modifications to
5545 configure the Linux device drivers for use with your target hardware
5546 (no, we don't intend to provide a full virtual machine interface to
5549 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5551 Just make sure your machine specific header file (for instance
5552 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5553 Information structure as we define in include/asm-<arch>/u-boot.h,
5554 and make sure that your definition of IMAP_ADDR uses the same value
5555 as your U-Boot configuration in CONFIG_SYS_IMMR.
5557 Note that U-Boot now has a driver model, a unified model for drivers.
5558 If you are adding a new driver, plumb it into driver model. If there
5559 is no uclass available, you are encouraged to create one. See
5563 Configuring the Linux kernel:
5564 -----------------------------
5566 No specific requirements for U-Boot. Make sure you have some root
5567 device (initial ramdisk, NFS) for your target system.
5570 Building a Linux Image:
5571 -----------------------
5573 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5574 not used. If you use recent kernel source, a new build target
5575 "uImage" will exist which automatically builds an image usable by
5576 U-Boot. Most older kernels also have support for a "pImage" target,
5577 which was introduced for our predecessor project PPCBoot and uses a
5578 100% compatible format.
5582 make TQM850L_defconfig
5587 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5588 encapsulate a compressed Linux kernel image with header information,
5589 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5591 * build a standard "vmlinux" kernel image (in ELF binary format):
5593 * convert the kernel into a raw binary image:
5595 ${CROSS_COMPILE}-objcopy -O binary \
5596 -R .note -R .comment \
5597 -S vmlinux linux.bin
5599 * compress the binary image:
5603 * package compressed binary image for U-Boot:
5605 mkimage -A ppc -O linux -T kernel -C gzip \
5606 -a 0 -e 0 -n "Linux Kernel Image" \
5607 -d linux.bin.gz uImage
5610 The "mkimage" tool can also be used to create ramdisk images for use
5611 with U-Boot, either separated from the Linux kernel image, or
5612 combined into one file. "mkimage" encapsulates the images with a 64
5613 byte header containing information about target architecture,
5614 operating system, image type, compression method, entry points, time
5615 stamp, CRC32 checksums, etc.
5617 "mkimage" can be called in two ways: to verify existing images and
5618 print the header information, or to build new images.
5620 In the first form (with "-l" option) mkimage lists the information
5621 contained in the header of an existing U-Boot image; this includes
5622 checksum verification:
5624 tools/mkimage -l image
5625 -l ==> list image header information
5627 The second form (with "-d" option) is used to build a U-Boot image
5628 from a "data file" which is used as image payload:
5630 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5631 -n name -d data_file image
5632 -A ==> set architecture to 'arch'
5633 -O ==> set operating system to 'os'
5634 -T ==> set image type to 'type'
5635 -C ==> set compression type 'comp'
5636 -a ==> set load address to 'addr' (hex)
5637 -e ==> set entry point to 'ep' (hex)
5638 -n ==> set image name to 'name'
5639 -d ==> use image data from 'datafile'
5641 Right now, all Linux kernels for PowerPC systems use the same load
5642 address (0x00000000), but the entry point address depends on the
5645 - 2.2.x kernels have the entry point at 0x0000000C,
5646 - 2.3.x and later kernels have the entry point at 0x00000000.
5648 So a typical call to build a U-Boot image would read:
5650 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5651 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5652 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5653 > examples/uImage.TQM850L
5654 Image Name: 2.4.4 kernel for TQM850L
5655 Created: Wed Jul 19 02:34:59 2000
5656 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5657 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5658 Load Address: 0x00000000
5659 Entry Point: 0x00000000
5661 To verify the contents of the image (or check for corruption):
5663 -> tools/mkimage -l examples/uImage.TQM850L
5664 Image Name: 2.4.4 kernel for TQM850L
5665 Created: Wed Jul 19 02:34:59 2000
5666 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5667 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5668 Load Address: 0x00000000
5669 Entry Point: 0x00000000
5671 NOTE: for embedded systems where boot time is critical you can trade
5672 speed for memory and install an UNCOMPRESSED image instead: this
5673 needs more space in Flash, but boots much faster since it does not
5674 need to be uncompressed:
5676 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5677 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5678 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5679 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5680 > examples/uImage.TQM850L-uncompressed
5681 Image Name: 2.4.4 kernel for TQM850L
5682 Created: Wed Jul 19 02:34:59 2000
5683 Image Type: PowerPC Linux Kernel Image (uncompressed)
5684 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5685 Load Address: 0x00000000
5686 Entry Point: 0x00000000
5689 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5690 when your kernel is intended to use an initial ramdisk:
5692 -> tools/mkimage -n 'Simple Ramdisk Image' \
5693 > -A ppc -O linux -T ramdisk -C gzip \
5694 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5695 Image Name: Simple Ramdisk Image
5696 Created: Wed Jan 12 14:01:50 2000
5697 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5698 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5699 Load Address: 0x00000000
5700 Entry Point: 0x00000000
5702 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5703 option performs the converse operation of the mkimage's second form (the "-d"
5704 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5707 tools/dumpimage -i image -T type -p position data_file
5708 -i ==> extract from the 'image' a specific 'data_file'
5709 -T ==> set image type to 'type'
5710 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5713 Installing a Linux Image:
5714 -------------------------
5716 To downloading a U-Boot image over the serial (console) interface,
5717 you must convert the image to S-Record format:
5719 objcopy -I binary -O srec examples/image examples/image.srec
5721 The 'objcopy' does not understand the information in the U-Boot
5722 image header, so the resulting S-Record file will be relative to
5723 address 0x00000000. To load it to a given address, you need to
5724 specify the target address as 'offset' parameter with the 'loads'
5727 Example: install the image to address 0x40100000 (which on the
5728 TQM8xxL is in the first Flash bank):
5730 => erase 40100000 401FFFFF
5736 ## Ready for S-Record download ...
5737 ~>examples/image.srec
5738 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5740 15989 15990 15991 15992
5741 [file transfer complete]
5743 ## Start Addr = 0x00000000
5746 You can check the success of the download using the 'iminfo' command;
5747 this includes a checksum verification so you can be sure no data
5748 corruption happened:
5752 ## Checking Image at 40100000 ...
5753 Image Name: 2.2.13 for initrd on TQM850L
5754 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5755 Data Size: 335725 Bytes = 327 kB = 0 MB
5756 Load Address: 00000000
5757 Entry Point: 0000000c
5758 Verifying Checksum ... OK
5764 The "bootm" command is used to boot an application that is stored in
5765 memory (RAM or Flash). In case of a Linux kernel image, the contents
5766 of the "bootargs" environment variable is passed to the kernel as
5767 parameters. You can check and modify this variable using the
5768 "printenv" and "setenv" commands:
5771 => printenv bootargs
5772 bootargs=root=/dev/ram
5774 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5776 => printenv bootargs
5777 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5780 ## Booting Linux kernel at 40020000 ...
5781 Image Name: 2.2.13 for NFS on TQM850L
5782 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5783 Data Size: 381681 Bytes = 372 kB = 0 MB
5784 Load Address: 00000000
5785 Entry Point: 0000000c
5786 Verifying Checksum ... OK
5787 Uncompressing Kernel Image ... OK
5788 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
5789 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5790 time_init: decrementer frequency = 187500000/60
5791 Calibrating delay loop... 49.77 BogoMIPS
5792 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5795 If you want to boot a Linux kernel with initial RAM disk, you pass
5796 the memory addresses of both the kernel and the initrd image (PPBCOOT
5797 format!) to the "bootm" command:
5799 => imi 40100000 40200000
5801 ## Checking Image at 40100000 ...
5802 Image Name: 2.2.13 for initrd on TQM850L
5803 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5804 Data Size: 335725 Bytes = 327 kB = 0 MB
5805 Load Address: 00000000
5806 Entry Point: 0000000c
5807 Verifying Checksum ... OK
5809 ## Checking Image at 40200000 ...
5810 Image Name: Simple Ramdisk Image
5811 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5812 Data Size: 566530 Bytes = 553 kB = 0 MB
5813 Load Address: 00000000
5814 Entry Point: 00000000
5815 Verifying Checksum ... OK
5817 => bootm 40100000 40200000
5818 ## Booting Linux kernel at 40100000 ...
5819 Image Name: 2.2.13 for initrd on TQM850L
5820 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5821 Data Size: 335725 Bytes = 327 kB = 0 MB
5822 Load Address: 00000000
5823 Entry Point: 0000000c
5824 Verifying Checksum ... OK
5825 Uncompressing Kernel Image ... OK
5826 ## Loading RAMDisk Image at 40200000 ...
5827 Image Name: Simple Ramdisk Image
5828 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5829 Data Size: 566530 Bytes = 553 kB = 0 MB
5830 Load Address: 00000000
5831 Entry Point: 00000000
5832 Verifying Checksum ... OK
5833 Loading Ramdisk ... OK
5834 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
5835 Boot arguments: root=/dev/ram
5836 time_init: decrementer frequency = 187500000/60
5837 Calibrating delay loop... 49.77 BogoMIPS
5839 RAMDISK: Compressed image found at block 0
5840 VFS: Mounted root (ext2 filesystem).
5844 Boot Linux and pass a flat device tree:
5847 First, U-Boot must be compiled with the appropriate defines. See the section
5848 titled "Linux Kernel Interface" above for a more in depth explanation. The
5849 following is an example of how to start a kernel and pass an updated
5855 oft=oftrees/mpc8540ads.dtb
5856 => tftp $oftaddr $oft
5857 Speed: 1000, full duplex
5859 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5860 Filename 'oftrees/mpc8540ads.dtb'.
5861 Load address: 0x300000
5864 Bytes transferred = 4106 (100a hex)
5865 => tftp $loadaddr $bootfile
5866 Speed: 1000, full duplex
5868 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5870 Load address: 0x200000
5871 Loading:############
5873 Bytes transferred = 1029407 (fb51f hex)
5878 => bootm $loadaddr - $oftaddr
5879 ## Booting image at 00200000 ...
5880 Image Name: Linux-2.6.17-dirty
5881 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5882 Data Size: 1029343 Bytes = 1005.2 kB
5883 Load Address: 00000000
5884 Entry Point: 00000000
5885 Verifying Checksum ... OK
5886 Uncompressing Kernel Image ... OK
5887 Booting using flat device tree at 0x300000
5888 Using MPC85xx ADS machine description
5889 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5893 More About U-Boot Image Types:
5894 ------------------------------
5896 U-Boot supports the following image types:
5898 "Standalone Programs" are directly runnable in the environment
5899 provided by U-Boot; it is expected that (if they behave
5900 well) you can continue to work in U-Boot after return from
5901 the Standalone Program.
5902 "OS Kernel Images" are usually images of some Embedded OS which
5903 will take over control completely. Usually these programs
5904 will install their own set of exception handlers, device
5905 drivers, set up the MMU, etc. - this means, that you cannot
5906 expect to re-enter U-Boot except by resetting the CPU.
5907 "RAMDisk Images" are more or less just data blocks, and their
5908 parameters (address, size) are passed to an OS kernel that is
5910 "Multi-File Images" contain several images, typically an OS
5911 (Linux) kernel image and one or more data images like
5912 RAMDisks. This construct is useful for instance when you want
5913 to boot over the network using BOOTP etc., where the boot
5914 server provides just a single image file, but you want to get
5915 for instance an OS kernel and a RAMDisk image.
5917 "Multi-File Images" start with a list of image sizes, each
5918 image size (in bytes) specified by an "uint32_t" in network
5919 byte order. This list is terminated by an "(uint32_t)0".
5920 Immediately after the terminating 0 follow the images, one by
5921 one, all aligned on "uint32_t" boundaries (size rounded up to
5922 a multiple of 4 bytes).
5924 "Firmware Images" are binary images containing firmware (like
5925 U-Boot or FPGA images) which usually will be programmed to
5928 "Script files" are command sequences that will be executed by
5929 U-Boot's command interpreter; this feature is especially
5930 useful when you configure U-Boot to use a real shell (hush)
5931 as command interpreter.
5933 Booting the Linux zImage:
5934 -------------------------
5936 On some platforms, it's possible to boot Linux zImage. This is done
5937 using the "bootz" command. The syntax of "bootz" command is the same
5938 as the syntax of "bootm" command.
5940 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5941 kernel with raw initrd images. The syntax is slightly different, the
5942 address of the initrd must be augmented by it's size, in the following
5943 format: "<initrd addres>:<initrd size>".
5949 One of the features of U-Boot is that you can dynamically load and
5950 run "standalone" applications, which can use some resources of
5951 U-Boot like console I/O functions or interrupt services.
5953 Two simple examples are included with the sources:
5958 'examples/hello_world.c' contains a small "Hello World" Demo
5959 application; it is automatically compiled when you build U-Boot.
5960 It's configured to run at address 0x00040004, so you can play with it
5964 ## Ready for S-Record download ...
5965 ~>examples/hello_world.srec
5966 1 2 3 4 5 6 7 8 9 10 11 ...
5967 [file transfer complete]
5969 ## Start Addr = 0x00040004
5971 => go 40004 Hello World! This is a test.
5972 ## Starting application at 0x00040004 ...
5983 Hit any key to exit ...
5985 ## Application terminated, rc = 0x0
5987 Another example, which demonstrates how to register a CPM interrupt
5988 handler with the U-Boot code, can be found in 'examples/timer.c'.
5989 Here, a CPM timer is set up to generate an interrupt every second.
5990 The interrupt service routine is trivial, just printing a '.'
5991 character, but this is just a demo program. The application can be
5992 controlled by the following keys:
5994 ? - print current values og the CPM Timer registers
5995 b - enable interrupts and start timer
5996 e - stop timer and disable interrupts
5997 q - quit application
6000 ## Ready for S-Record download ...
6001 ~>examples/timer.srec
6002 1 2 3 4 5 6 7 8 9 10 11 ...
6003 [file transfer complete]
6005 ## Start Addr = 0x00040004
6008 ## Starting application at 0x00040004 ...
6011 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6014 [q, b, e, ?] Set interval 1000000 us
6017 [q, b, e, ?] ........
6018 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6021 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6024 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6027 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6029 [q, b, e, ?] ...Stopping timer
6031 [q, b, e, ?] ## Application terminated, rc = 0x0
6037 Over time, many people have reported problems when trying to use the
6038 "minicom" terminal emulation program for serial download. I (wd)
6039 consider minicom to be broken, and recommend not to use it. Under
6040 Unix, I recommend to use C-Kermit for general purpose use (and
6041 especially for kermit binary protocol download ("loadb" command), and
6042 use "cu" for S-Record download ("loads" command). See
6043 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6044 for help with kermit.
6047 Nevertheless, if you absolutely want to use it try adding this
6048 configuration to your "File transfer protocols" section:
6050 Name Program Name U/D FullScr IO-Red. Multi
6051 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6052 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6058 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6059 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6061 Building requires a cross environment; it is known to work on
6062 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6063 need gmake since the Makefiles are not compatible with BSD make).
6064 Note that the cross-powerpc package does not install include files;
6065 attempting to build U-Boot will fail because <machine/ansi.h> is
6066 missing. This file has to be installed and patched manually:
6068 # cd /usr/pkg/cross/powerpc-netbsd/include
6070 # ln -s powerpc machine
6071 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6072 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6074 Native builds *don't* work due to incompatibilities between native
6075 and U-Boot include files.
6077 Booting assumes that (the first part of) the image booted is a
6078 stage-2 loader which in turn loads and then invokes the kernel
6079 proper. Loader sources will eventually appear in the NetBSD source
6080 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6081 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6084 Implementation Internals:
6085 =========================
6087 The following is not intended to be a complete description of every
6088 implementation detail. However, it should help to understand the
6089 inner workings of U-Boot and make it easier to port it to custom
6093 Initial Stack, Global Data:
6094 ---------------------------
6096 The implementation of U-Boot is complicated by the fact that U-Boot
6097 starts running out of ROM (flash memory), usually without access to
6098 system RAM (because the memory controller is not initialized yet).
6099 This means that we don't have writable Data or BSS segments, and BSS
6100 is not initialized as zero. To be able to get a C environment working
6101 at all, we have to allocate at least a minimal stack. Implementation
6102 options for this are defined and restricted by the CPU used: Some CPU
6103 models provide on-chip memory (like the IMMR area on MPC8xx and
6104 MPC826x processors), on others (parts of) the data cache can be
6105 locked as (mis-) used as memory, etc.
6107 Chris Hallinan posted a good summary of these issues to the
6108 U-Boot mailing list:
6110 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6111 From: "Chris Hallinan" <clh@net1plus.com>
6112 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6115 Correct me if I'm wrong, folks, but the way I understand it
6116 is this: Using DCACHE as initial RAM for Stack, etc, does not
6117 require any physical RAM backing up the cache. The cleverness
6118 is that the cache is being used as a temporary supply of
6119 necessary storage before the SDRAM controller is setup. It's
6120 beyond the scope of this list to explain the details, but you
6121 can see how this works by studying the cache architecture and
6122 operation in the architecture and processor-specific manuals.
6124 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6125 is another option for the system designer to use as an
6126 initial stack/RAM area prior to SDRAM being available. Either
6127 option should work for you. Using CS 4 should be fine if your
6128 board designers haven't used it for something that would
6129 cause you grief during the initial boot! It is frequently not
6132 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6133 with your processor/board/system design. The default value
6134 you will find in any recent u-boot distribution in
6135 walnut.h should work for you. I'd set it to a value larger
6136 than your SDRAM module. If you have a 64MB SDRAM module, set
6137 it above 400_0000. Just make sure your board has no resources
6138 that are supposed to respond to that address! That code in
6139 start.S has been around a while and should work as is when
6140 you get the config right.
6145 It is essential to remember this, since it has some impact on the C
6146 code for the initialization procedures:
6148 * Initialized global data (data segment) is read-only. Do not attempt
6151 * Do not use any uninitialized global data (or implicitly initialized
6152 as zero data - BSS segment) at all - this is undefined, initiali-
6153 zation is performed later (when relocating to RAM).
6155 * Stack space is very limited. Avoid big data buffers or things like
6158 Having only the stack as writable memory limits means we cannot use
6159 normal global data to share information between the code. But it
6160 turned out that the implementation of U-Boot can be greatly
6161 simplified by making a global data structure (gd_t) available to all
6162 functions. We could pass a pointer to this data as argument to _all_
6163 functions, but this would bloat the code. Instead we use a feature of
6164 the GCC compiler (Global Register Variables) to share the data: we
6165 place a pointer (gd) to the global data into a register which we
6166 reserve for this purpose.
6168 When choosing a register for such a purpose we are restricted by the
6169 relevant (E)ABI specifications for the current architecture, and by
6170 GCC's implementation.
6172 For PowerPC, the following registers have specific use:
6174 R2: reserved for system use
6175 R3-R4: parameter passing and return values
6176 R5-R10: parameter passing
6177 R13: small data area pointer
6181 (U-Boot also uses R12 as internal GOT pointer. r12
6182 is a volatile register so r12 needs to be reset when
6183 going back and forth between asm and C)
6185 ==> U-Boot will use R2 to hold a pointer to the global data
6187 Note: on PPC, we could use a static initializer (since the
6188 address of the global data structure is known at compile time),
6189 but it turned out that reserving a register results in somewhat
6190 smaller code - although the code savings are not that big (on
6191 average for all boards 752 bytes for the whole U-Boot image,
6192 624 text + 127 data).
6194 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6195 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6197 ==> U-Boot will use P3 to hold a pointer to the global data
6199 On ARM, the following registers are used:
6201 R0: function argument word/integer result
6202 R1-R3: function argument word
6203 R9: platform specific
6204 R10: stack limit (used only if stack checking is enabled)
6205 R11: argument (frame) pointer
6206 R12: temporary workspace
6209 R15: program counter
6211 ==> U-Boot will use R9 to hold a pointer to the global data
6213 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6215 On Nios II, the ABI is documented here:
6216 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6218 ==> U-Boot will use gp to hold a pointer to the global data
6220 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6221 to access small data sections, so gp is free.
6223 On NDS32, the following registers are used:
6225 R0-R1: argument/return
6227 R15: temporary register for assembler
6228 R16: trampoline register
6229 R28: frame pointer (FP)
6230 R29: global pointer (GP)
6231 R30: link register (LP)
6232 R31: stack pointer (SP)
6233 PC: program counter (PC)
6235 ==> U-Boot will use R10 to hold a pointer to the global data
6237 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6238 or current versions of GCC may "optimize" the code too much.
6243 U-Boot runs in system state and uses physical addresses, i.e. the
6244 MMU is not used either for address mapping nor for memory protection.
6246 The available memory is mapped to fixed addresses using the memory
6247 controller. In this process, a contiguous block is formed for each
6248 memory type (Flash, SDRAM, SRAM), even when it consists of several
6249 physical memory banks.
6251 U-Boot is installed in the first 128 kB of the first Flash bank (on
6252 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6253 booting and sizing and initializing DRAM, the code relocates itself
6254 to the upper end of DRAM. Immediately below the U-Boot code some
6255 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6256 configuration setting]. Below that, a structure with global Board
6257 Info data is placed, followed by the stack (growing downward).
6259 Additionally, some exception handler code is copied to the low 8 kB
6260 of DRAM (0x00000000 ... 0x00001FFF).
6262 So a typical memory configuration with 16 MB of DRAM could look like
6265 0x0000 0000 Exception Vector code
6268 0x0000 2000 Free for Application Use
6274 0x00FB FF20 Monitor Stack (Growing downward)
6275 0x00FB FFAC Board Info Data and permanent copy of global data
6276 0x00FC 0000 Malloc Arena
6279 0x00FE 0000 RAM Copy of Monitor Code
6280 ... eventually: LCD or video framebuffer
6281 ... eventually: pRAM (Protected RAM - unchanged by reset)
6282 0x00FF FFFF [End of RAM]
6285 System Initialization:
6286 ----------------------
6288 In the reset configuration, U-Boot starts at the reset entry point
6289 (on most PowerPC systems at address 0x00000100). Because of the reset
6290 configuration for CS0# this is a mirror of the on board Flash memory.
6291 To be able to re-map memory U-Boot then jumps to its link address.
6292 To be able to implement the initialization code in C, a (small!)
6293 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6294 which provide such a feature like MPC8xx or MPC8260), or in a locked
6295 part of the data cache. After that, U-Boot initializes the CPU core,
6296 the caches and the SIU.
6298 Next, all (potentially) available memory banks are mapped using a
6299 preliminary mapping. For example, we put them on 512 MB boundaries
6300 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6301 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6302 programmed for SDRAM access. Using the temporary configuration, a
6303 simple memory test is run that determines the size of the SDRAM
6306 When there is more than one SDRAM bank, and the banks are of
6307 different size, the largest is mapped first. For equal size, the first
6308 bank (CS2#) is mapped first. The first mapping is always for address
6309 0x00000000, with any additional banks following immediately to create
6310 contiguous memory starting from 0.
6312 Then, the monitor installs itself at the upper end of the SDRAM area
6313 and allocates memory for use by malloc() and for the global Board
6314 Info data; also, the exception vector code is copied to the low RAM
6315 pages, and the final stack is set up.
6317 Only after this relocation will you have a "normal" C environment;
6318 until that you are restricted in several ways, mostly because you are
6319 running from ROM, and because the code will have to be relocated to a
6323 U-Boot Porting Guide:
6324 ----------------------
6326 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6330 int main(int argc, char *argv[])
6332 sighandler_t no_more_time;
6334 signal(SIGALRM, no_more_time);
6335 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6337 if (available_money > available_manpower) {
6338 Pay consultant to port U-Boot;
6342 Download latest U-Boot source;
6344 Subscribe to u-boot mailing list;
6347 email("Hi, I am new to U-Boot, how do I get started?");
6350 Read the README file in the top level directory;
6351 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6352 Read applicable doc/*.README;
6353 Read the source, Luke;
6354 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6357 if (available_money > toLocalCurrency ($2500))
6360 Add a lot of aggravation and time;
6362 if (a similar board exists) { /* hopefully... */
6363 cp -a board/<similar> board/<myboard>
6364 cp include/configs/<similar>.h include/configs/<myboard>.h
6366 Create your own board support subdirectory;
6367 Create your own board include/configs/<myboard>.h file;
6369 Edit new board/<myboard> files
6370 Edit new include/configs/<myboard>.h
6375 Add / modify source code;
6379 email("Hi, I am having problems...");
6381 Send patch file to the U-Boot email list;
6382 if (reasonable critiques)
6383 Incorporate improvements from email list code review;
6385 Defend code as written;
6391 void no_more_time (int sig)
6400 All contributions to U-Boot should conform to the Linux kernel
6401 coding style; see the file "Documentation/CodingStyle" and the script
6402 "scripts/Lindent" in your Linux kernel source directory.
6404 Source files originating from a different project (for example the
6405 MTD subsystem) are generally exempt from these guidelines and are not
6406 reformatted to ease subsequent migration to newer versions of those
6409 Please note that U-Boot is implemented in C (and to some small parts in
6410 Assembler); no C++ is used, so please do not use C++ style comments (//)
6413 Please also stick to the following formatting rules:
6414 - remove any trailing white space
6415 - use TAB characters for indentation and vertical alignment, not spaces
6416 - make sure NOT to use DOS '\r\n' line feeds
6417 - do not add more than 2 consecutive empty lines to source files
6418 - do not add trailing empty lines to source files
6420 Submissions which do not conform to the standards may be returned
6421 with a request to reformat the changes.
6427 Since the number of patches for U-Boot is growing, we need to
6428 establish some rules. Submissions which do not conform to these rules
6429 may be rejected, even when they contain important and valuable stuff.
6431 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6433 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6434 see http://lists.denx.de/mailman/listinfo/u-boot
6436 When you send a patch, please include the following information with
6439 * For bug fixes: a description of the bug and how your patch fixes
6440 this bug. Please try to include a way of demonstrating that the
6441 patch actually fixes something.
6443 * For new features: a description of the feature and your
6446 * A CHANGELOG entry as plaintext (separate from the patch)
6448 * For major contributions, add a MAINTAINERS file with your
6449 information and associated file and directory references.
6451 * When you add support for a new board, don't forget to add a
6452 maintainer e-mail address to the boards.cfg file, too.
6454 * If your patch adds new configuration options, don't forget to
6455 document these in the README file.
6457 * The patch itself. If you are using git (which is *strongly*
6458 recommended) you can easily generate the patch using the
6459 "git format-patch". If you then use "git send-email" to send it to
6460 the U-Boot mailing list, you will avoid most of the common problems
6461 with some other mail clients.
6463 If you cannot use git, use "diff -purN OLD NEW". If your version of
6464 diff does not support these options, then get the latest version of
6467 The current directory when running this command shall be the parent
6468 directory of the U-Boot source tree (i. e. please make sure that
6469 your patch includes sufficient directory information for the
6472 We prefer patches as plain text. MIME attachments are discouraged,
6473 and compressed attachments must not be used.
6475 * If one logical set of modifications affects or creates several
6476 files, all these changes shall be submitted in a SINGLE patch file.
6478 * Changesets that contain different, unrelated modifications shall be
6479 submitted as SEPARATE patches, one patch per changeset.
6484 * Before sending the patch, run the buildman script on your patched
6485 source tree and make sure that no errors or warnings are reported
6486 for any of the boards.
6488 * Keep your modifications to the necessary minimum: A patch
6489 containing several unrelated changes or arbitrary reformats will be
6490 returned with a request to re-formatting / split it.
6492 * If you modify existing code, make sure that your new code does not
6493 add to the memory footprint of the code ;-) Small is beautiful!
6494 When adding new features, these should compile conditionally only
6495 (using #ifdef), and the resulting code with the new feature
6496 disabled must not need more memory than the old code without your
6499 * Remember that there is a size limit of 100 kB per message on the
6500 u-boot mailing list. Bigger patches will be moderated. If they are
6501 reasonable and not too big, they will be acknowledged. But patches
6502 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob