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 and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 - Linux Kernel Interface:
697 U-Boot stores all clock information in Hz
698 internally. For binary compatibility with older Linux
699 kernels (which expect the clocks passed in the
700 bd_info data to be in MHz) the environment variable
701 "clocks_in_mhz" can be defined so that U-Boot
702 converts clock data to MHZ before passing it to the
704 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
705 "clocks_in_mhz=1" is automatically included in the
708 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
710 When transferring memsize parameter to Linux, some versions
711 expect it to be in bytes, others in MB.
712 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
716 New kernel versions are expecting firmware settings to be
717 passed using flattened device trees (based on open firmware
721 * New libfdt-based support
722 * Adds the "fdt" command
723 * The bootm command automatically updates the fdt
725 OF_CPU - The proper name of the cpus node (only required for
726 MPC512X and MPC5xxx based boards).
727 OF_SOC - The proper name of the soc node (only required for
728 MPC512X and MPC5xxx based boards).
729 OF_TBCLK - The timebase frequency.
730 OF_STDOUT_PATH - The path to the console device
732 boards with QUICC Engines require OF_QE to set UCC MAC
735 CONFIG_OF_BOARD_SETUP
737 Board code has addition modification that it wants to make
738 to the flat device tree before handing it off to the kernel
740 CONFIG_OF_SYSTEM_SETUP
742 Other code has addition modification that it wants to make
743 to the flat device tree before handing it off to the kernel.
744 This causes ft_system_setup() to be called before booting
749 This define fills in the correct boot CPU in the boot
750 param header, the default value is zero if undefined.
754 U-Boot can detect if an IDE device is present or not.
755 If not, and this new config option is activated, U-Boot
756 removes the ATA node from the DTS before booting Linux,
757 so the Linux IDE driver does not probe the device and
758 crash. This is needed for buggy hardware (uc101) where
759 no pull down resistor is connected to the signal IDE5V_DD7.
761 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
763 This setting is mandatory for all boards that have only one
764 machine type and must be used to specify the machine type
765 number as it appears in the ARM machine registry
766 (see http://www.arm.linux.org.uk/developer/machines/).
767 Only boards that have multiple machine types supported
768 in a single configuration file and the machine type is
769 runtime discoverable, do not have to use this setting.
771 - vxWorks boot parameters:
773 bootvx constructs a valid bootline using the following
774 environments variables: bootfile, ipaddr, serverip, hostname.
775 It loads the vxWorks image pointed bootfile.
777 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
778 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
779 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
780 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
782 CONFIG_SYS_VXWORKS_ADD_PARAMS
784 Add it at the end of the bootline. E.g "u=username pw=secret"
786 Note: If a "bootargs" environment is defined, it will overwride
787 the defaults discussed just above.
789 - Cache Configuration:
790 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
791 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
792 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
794 - Cache Configuration for ARM:
795 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
797 CONFIG_SYS_PL310_BASE - Physical base address of PL310
798 controller register space
803 Define this if you want support for Amba PrimeCell PL010 UARTs.
807 Define this if you want support for Amba PrimeCell PL011 UARTs.
811 If you have Amba PrimeCell PL011 UARTs, set this variable to
812 the clock speed of the UARTs.
816 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
817 define this to a list of base addresses for each (supported)
818 port. See e.g. include/configs/versatile.h
820 CONFIG_PL011_SERIAL_RLCR
822 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
823 have separate receive and transmit line control registers. Set
824 this variable to initialize the extra register.
826 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
828 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
829 boot loader that has already initialized the UART. Define this
830 variable to flush the UART at init time.
832 CONFIG_SERIAL_HW_FLOW_CONTROL
834 Define this variable to enable hw flow control in serial driver.
835 Current user of this option is drivers/serial/nsl16550.c driver
838 Depending on board, define exactly one serial port
839 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
840 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
841 console by defining CONFIG_8xx_CONS_NONE
843 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
844 port routines must be defined elsewhere
845 (i.e. serial_init(), serial_getc(), ...)
848 Enables console device for a color framebuffer. Needs following
849 defines (cf. smiLynxEM, i8042)
850 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
852 VIDEO_HW_RECTFILL graphic chip supports
855 VIDEO_HW_BITBLT graphic chip supports
856 bit-blit (cf. smiLynxEM)
857 VIDEO_VISIBLE_COLS visible pixel columns
859 VIDEO_VISIBLE_ROWS visible pixel rows
860 VIDEO_PIXEL_SIZE bytes per pixel
861 VIDEO_DATA_FORMAT graphic data format
862 (0-5, cf. cfb_console.c)
863 VIDEO_FB_ADRS framebuffer address
864 VIDEO_KBD_INIT_FCT keyboard int fct
865 (i.e. i8042_kbd_init())
866 VIDEO_TSTC_FCT test char fct
868 VIDEO_GETC_FCT get char fct
870 CONFIG_CONSOLE_CURSOR cursor drawing on/off
871 (requires blink timer
873 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
874 CONFIG_CONSOLE_TIME display time/date info in
876 (requires CONFIG_CMD_DATE)
877 CONFIG_VIDEO_LOGO display Linux logo in
879 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
880 linux_logo.h for logo.
881 Requires CONFIG_VIDEO_LOGO
882 CONFIG_CONSOLE_EXTRA_INFO
883 additional board info beside
886 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
887 a limited number of ANSI escape sequences (cursor control,
888 erase functions and limited graphics rendition control).
890 When CONFIG_CFB_CONSOLE is defined, video console is
891 default i/o. Serial console can be forced with
892 environment 'console=serial'.
894 When CONFIG_SILENT_CONSOLE is defined, all console
895 messages (by U-Boot and Linux!) can be silenced with
896 the "silent" environment variable. See
897 doc/README.silent for more information.
899 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
901 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
905 CONFIG_BAUDRATE - in bps
906 Select one of the baudrates listed in
907 CONFIG_SYS_BAUDRATE_TABLE, see below.
908 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
910 - Console Rx buffer length
911 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
912 the maximum receive buffer length for the SMC.
913 This option is actual only for 82xx and 8xx possible.
914 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
915 must be defined, to setup the maximum idle timeout for
918 - Pre-Console Buffer:
919 Prior to the console being initialised (i.e. serial UART
920 initialised etc) all console output is silently discarded.
921 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
922 buffer any console messages prior to the console being
923 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
924 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
925 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
926 bytes are output before the console is initialised, the
927 earlier bytes are discarded.
929 'Sane' compilers will generate smaller code if
930 CONFIG_PRE_CON_BUF_SZ is a power of 2
932 - Safe printf() functions
933 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
934 the printf() functions. These are defined in
935 include/vsprintf.h and include snprintf(), vsnprintf() and
936 so on. Code size increase is approximately 300-500 bytes.
937 If this option is not given then these functions will
938 silently discard their buffer size argument - this means
939 you are not getting any overflow checking in this case.
941 - Boot Delay: CONFIG_BOOTDELAY - in seconds
942 Delay before automatically booting the default image;
943 set to -1 to disable autoboot.
944 set to -2 to autoboot with no delay and not check for abort
945 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
947 See doc/README.autoboot for these options that
948 work with CONFIG_BOOTDELAY. None are required.
949 CONFIG_BOOT_RETRY_TIME
950 CONFIG_BOOT_RETRY_MIN
951 CONFIG_AUTOBOOT_KEYED
952 CONFIG_AUTOBOOT_PROMPT
953 CONFIG_AUTOBOOT_DELAY_STR
954 CONFIG_AUTOBOOT_STOP_STR
955 CONFIG_AUTOBOOT_DELAY_STR2
956 CONFIG_AUTOBOOT_STOP_STR2
957 CONFIG_ZERO_BOOTDELAY_CHECK
958 CONFIG_RESET_TO_RETRY
962 Only needed when CONFIG_BOOTDELAY is enabled;
963 define a command string that is automatically executed
964 when no character is read on the console interface
965 within "Boot Delay" after reset.
968 This can be used to pass arguments to the bootm
969 command. The value of CONFIG_BOOTARGS goes into the
970 environment value "bootargs".
972 CONFIG_RAMBOOT and CONFIG_NFSBOOT
973 The value of these goes into the environment as
974 "ramboot" and "nfsboot" respectively, and can be used
975 as a convenience, when switching between booting from
979 CONFIG_BOOTCOUNT_LIMIT
980 Implements a mechanism for detecting a repeating reboot
982 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
985 If no softreset save registers are found on the hardware
986 "bootcount" is stored in the environment. To prevent a
987 saveenv on all reboots, the environment variable
988 "upgrade_available" is used. If "upgrade_available" is
989 0, "bootcount" is always 0, if "upgrade_available" is
990 1 "bootcount" is incremented in the environment.
991 So the Userspace Applikation must set the "upgrade_available"
992 and "bootcount" variable to 0, if a boot was successfully.
997 When this option is #defined, the existence of the
998 environment variable "preboot" will be checked
999 immediately before starting the CONFIG_BOOTDELAY
1000 countdown and/or running the auto-boot command resp.
1001 entering interactive mode.
1003 This feature is especially useful when "preboot" is
1004 automatically generated or modified. For an example
1005 see the LWMON board specific code: here "preboot" is
1006 modified when the user holds down a certain
1007 combination of keys on the (special) keyboard when
1010 - Serial Download Echo Mode:
1012 If defined to 1, all characters received during a
1013 serial download (using the "loads" command) are
1014 echoed back. This might be needed by some terminal
1015 emulations (like "cu"), but may as well just take
1016 time on others. This setting #define's the initial
1017 value of the "loads_echo" environment variable.
1019 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1020 CONFIG_KGDB_BAUDRATE
1021 Select one of the baudrates listed in
1022 CONFIG_SYS_BAUDRATE_TABLE, see below.
1024 - Monitor Functions:
1025 Monitor commands can be included or excluded
1026 from the build by using the #include files
1027 <config_cmd_all.h> and #undef'ing unwanted
1028 commands, or using <config_cmd_default.h>
1029 and augmenting with additional #define's
1030 for wanted commands.
1032 The default command configuration includes all commands
1033 except those marked below with a "*".
1035 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1036 CONFIG_CMD_ASKENV * ask for env variable
1037 CONFIG_CMD_BDI bdinfo
1038 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1039 CONFIG_CMD_BMP * BMP support
1040 CONFIG_CMD_BSP * Board specific commands
1041 CONFIG_CMD_BOOTD bootd
1042 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1043 CONFIG_CMD_CACHE * icache, dcache
1044 CONFIG_CMD_CLK * clock command support
1045 CONFIG_CMD_CONSOLE coninfo
1046 CONFIG_CMD_CRC32 * crc32
1047 CONFIG_CMD_DATE * support for RTC, date/time...
1048 CONFIG_CMD_DHCP * DHCP support
1049 CONFIG_CMD_DIAG * Diagnostics
1050 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1051 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1052 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1053 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1054 CONFIG_CMD_DTT * Digital Therm and Thermostat
1055 CONFIG_CMD_ECHO echo arguments
1056 CONFIG_CMD_EDITENV edit env variable
1057 CONFIG_CMD_EEPROM * EEPROM read/write support
1058 CONFIG_CMD_ELF * bootelf, bootvx
1059 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1060 CONFIG_CMD_ENV_FLAGS * display details about env flags
1061 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1062 CONFIG_CMD_EXPORTENV * export the environment
1063 CONFIG_CMD_EXT2 * ext2 command support
1064 CONFIG_CMD_EXT4 * ext4 command support
1065 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1066 that work for multiple fs types
1067 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1068 CONFIG_CMD_SAVEENV saveenv
1069 CONFIG_CMD_FDC * Floppy Disk Support
1070 CONFIG_CMD_FAT * FAT command support
1071 CONFIG_CMD_FLASH flinfo, erase, protect
1072 CONFIG_CMD_FPGA FPGA device initialization support
1073 CONFIG_CMD_FUSE * Device fuse support
1074 CONFIG_CMD_GETTIME * Get time since boot
1075 CONFIG_CMD_GO * the 'go' command (exec code)
1076 CONFIG_CMD_GREPENV * search environment
1077 CONFIG_CMD_HASH * calculate hash / digest
1078 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1079 CONFIG_CMD_I2C * I2C serial bus support
1080 CONFIG_CMD_IDE * IDE harddisk support
1081 CONFIG_CMD_IMI iminfo
1082 CONFIG_CMD_IMLS List all images found in NOR flash
1083 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1084 CONFIG_CMD_IMMAP * IMMR dump support
1085 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1086 CONFIG_CMD_IMPORTENV * import an environment
1087 CONFIG_CMD_INI * import data from an ini file into the env
1088 CONFIG_CMD_IRQ * irqinfo
1089 CONFIG_CMD_ITEST Integer/string test of 2 values
1090 CONFIG_CMD_JFFS2 * JFFS2 Support
1091 CONFIG_CMD_KGDB * kgdb
1092 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1093 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1095 CONFIG_CMD_LOADB loadb
1096 CONFIG_CMD_LOADS loads
1097 CONFIG_CMD_MD5SUM * print md5 message digest
1098 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1099 CONFIG_CMD_MEMINFO * Display detailed memory information
1100 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1102 CONFIG_CMD_MEMTEST * mtest
1103 CONFIG_CMD_MISC Misc functions like sleep etc
1104 CONFIG_CMD_MMC * MMC memory mapped support
1105 CONFIG_CMD_MII * MII utility commands
1106 CONFIG_CMD_MTDPARTS * MTD partition support
1107 CONFIG_CMD_NAND * NAND support
1108 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1109 CONFIG_CMD_NFS NFS support
1110 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1111 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1112 CONFIG_CMD_PCI * pciinfo
1113 CONFIG_CMD_PCMCIA * PCMCIA support
1114 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1116 CONFIG_CMD_PORTIO * Port I/O
1117 CONFIG_CMD_READ * Read raw data from partition
1118 CONFIG_CMD_REGINFO * Register dump
1119 CONFIG_CMD_RUN run command in env variable
1120 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1121 CONFIG_CMD_SAVES * save S record dump
1122 CONFIG_CMD_SCSI * SCSI Support
1123 CONFIG_CMD_SDRAM * print SDRAM configuration information
1124 (requires CONFIG_CMD_I2C)
1125 CONFIG_CMD_SETGETDCR Support for DCR Register access
1127 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1128 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1129 (requires CONFIG_CMD_MEMORY)
1130 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1131 CONFIG_CMD_SOURCE "source" command Support
1132 CONFIG_CMD_SPI * SPI serial bus support
1133 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1134 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1135 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1136 CONFIG_CMD_TIMER * access to the system tick timer
1137 CONFIG_CMD_USB * USB support
1138 CONFIG_CMD_CDP * Cisco Discover Protocol support
1139 CONFIG_CMD_MFSL * Microblaze FSL support
1140 CONFIG_CMD_XIMG Load part of Multi Image
1141 CONFIG_CMD_UUID * Generate random UUID or GUID string
1143 EXAMPLE: If you want all functions except of network
1144 support you can write:
1146 #include "config_cmd_all.h"
1147 #undef CONFIG_CMD_NET
1150 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1152 Note: Don't enable the "icache" and "dcache" commands
1153 (configuration option CONFIG_CMD_CACHE) unless you know
1154 what you (and your U-Boot users) are doing. Data
1155 cache cannot be enabled on systems like the 8xx or
1156 8260 (where accesses to the IMMR region must be
1157 uncached), and it cannot be disabled on all other
1158 systems where we (mis-) use the data cache to hold an
1159 initial stack and some data.
1162 XXX - this list needs to get updated!
1164 - Regular expression support:
1166 If this variable is defined, U-Boot is linked against
1167 the SLRE (Super Light Regular Expression) library,
1168 which adds regex support to some commands, as for
1169 example "env grep" and "setexpr".
1173 If this variable is defined, U-Boot will use a device tree
1174 to configure its devices, instead of relying on statically
1175 compiled #defines in the board file. This option is
1176 experimental and only available on a few boards. The device
1177 tree is available in the global data as gd->fdt_blob.
1179 U-Boot needs to get its device tree from somewhere. This can
1180 be done using one of the two options below:
1183 If this variable is defined, U-Boot will embed a device tree
1184 binary in its image. This device tree file should be in the
1185 board directory and called <soc>-<board>.dts. The binary file
1186 is then picked up in board_init_f() and made available through
1187 the global data structure as gd->blob.
1190 If this variable is defined, U-Boot will build a device tree
1191 binary. It will be called u-boot.dtb. Architecture-specific
1192 code will locate it at run-time. Generally this works by:
1194 cat u-boot.bin u-boot.dtb >image.bin
1196 and in fact, U-Boot does this for you, creating a file called
1197 u-boot-dtb.bin which is useful in the common case. You can
1198 still use the individual files if you need something more
1203 If this variable is defined, it enables watchdog
1204 support for the SoC. There must be support in the SoC
1205 specific code for a watchdog. For the 8xx and 8260
1206 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1207 register. When supported for a specific SoC is
1208 available, then no further board specific code should
1209 be needed to use it.
1212 When using a watchdog circuitry external to the used
1213 SoC, then define this variable and provide board
1214 specific code for the "hw_watchdog_reset" function.
1216 CONFIG_AT91_HW_WDT_TIMEOUT
1217 specify the timeout in seconds. default 2 seconds.
1220 CONFIG_VERSION_VARIABLE
1221 If this variable is defined, an environment variable
1222 named "ver" is created by U-Boot showing the U-Boot
1223 version as printed by the "version" command.
1224 Any change to this variable will be reverted at the
1229 When CONFIG_CMD_DATE is selected, the type of the RTC
1230 has to be selected, too. Define exactly one of the
1233 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1234 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1235 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1236 CONFIG_RTC_MC146818 - use MC146818 RTC
1237 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1238 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1239 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1240 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1241 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1242 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1243 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1244 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1245 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1248 Note that if the RTC uses I2C, then the I2C interface
1249 must also be configured. See I2C Support, below.
1252 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1254 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1255 chip-ngpio pairs that tell the PCA953X driver the number of
1256 pins supported by a particular chip.
1258 Note that if the GPIO device uses I2C, then the I2C interface
1259 must also be configured. See I2C Support, below.
1262 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1263 accesses and can checksum them or write a list of them out
1264 to memory. See the 'iotrace' command for details. This is
1265 useful for testing device drivers since it can confirm that
1266 the driver behaves the same way before and after a code
1267 change. Currently this is supported on sandbox and arm. To
1268 add support for your architecture, add '#include <iotrace.h>'
1269 to the bottom of arch/<arch>/include/asm/io.h and test.
1271 Example output from the 'iotrace stats' command is below.
1272 Note that if the trace buffer is exhausted, the checksum will
1273 still continue to operate.
1276 Start: 10000000 (buffer start address)
1277 Size: 00010000 (buffer size)
1278 Offset: 00000120 (current buffer offset)
1279 Output: 10000120 (start + offset)
1280 Count: 00000018 (number of trace records)
1281 CRC32: 9526fb66 (CRC32 of all trace records)
1283 - Timestamp Support:
1285 When CONFIG_TIMESTAMP is selected, the timestamp
1286 (date and time) of an image is printed by image
1287 commands like bootm or iminfo. This option is
1288 automatically enabled when you select CONFIG_CMD_DATE .
1290 - Partition Labels (disklabels) Supported:
1291 Zero or more of the following:
1292 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1293 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1294 Intel architecture, USB sticks, etc.
1295 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1296 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1297 bootloader. Note 2TB partition limit; see
1299 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1301 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1302 CONFIG_CMD_SCSI) you must configure support for at
1303 least one non-MTD partition type as well.
1306 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1307 board configurations files but used nowhere!
1309 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1310 be performed by calling the function
1311 ide_set_reset(int reset)
1312 which has to be defined in a board specific file
1317 Set this to enable ATAPI support.
1322 Set this to enable support for disks larger than 137GB
1323 Also look at CONFIG_SYS_64BIT_LBA.
1324 Whithout these , LBA48 support uses 32bit variables and will 'only'
1325 support disks up to 2.1TB.
1327 CONFIG_SYS_64BIT_LBA:
1328 When enabled, makes the IDE subsystem use 64bit sector addresses.
1332 At the moment only there is only support for the
1333 SYM53C8XX SCSI controller; define
1334 CONFIG_SCSI_SYM53C8XX to enable it.
1336 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1337 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1338 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1339 maximum numbers of LUNs, SCSI ID's and target
1341 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1343 The environment variable 'scsidevs' is set to the number of
1344 SCSI devices found during the last scan.
1346 - NETWORK Support (PCI):
1348 Support for Intel 8254x/8257x gigabit chips.
1351 Utility code for direct access to the SPI bus on Intel 8257x.
1352 This does not do anything useful unless you set at least one
1353 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1355 CONFIG_E1000_SPI_GENERIC
1356 Allow generic access to the SPI bus on the Intel 8257x, for
1357 example with the "sspi" command.
1360 Management command for E1000 devices. When used on devices
1361 with SPI support you can reprogram the EEPROM from U-Boot.
1363 CONFIG_E1000_FALLBACK_MAC
1364 default MAC for empty EEPROM after production.
1367 Support for Intel 82557/82559/82559ER chips.
1368 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1369 write routine for first time initialisation.
1372 Support for Digital 2114x chips.
1373 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1374 modem chip initialisation (KS8761/QS6611).
1377 Support for National dp83815 chips.
1380 Support for National dp8382[01] gigabit chips.
1382 - NETWORK Support (other):
1384 CONFIG_DRIVER_AT91EMAC
1385 Support for AT91RM9200 EMAC.
1388 Define this to use reduced MII inteface
1390 CONFIG_DRIVER_AT91EMAC_QUIET
1391 If this defined, the driver is quiet.
1392 The driver doen't show link status messages.
1394 CONFIG_CALXEDA_XGMAC
1395 Support for the Calxeda XGMAC device
1398 Support for SMSC's LAN91C96 chips.
1400 CONFIG_LAN91C96_BASE
1401 Define this to hold the physical address
1402 of the LAN91C96's I/O space
1404 CONFIG_LAN91C96_USE_32_BIT
1405 Define this to enable 32 bit addressing
1408 Support for SMSC's LAN91C111 chip
1410 CONFIG_SMC91111_BASE
1411 Define this to hold the physical address
1412 of the device (I/O space)
1414 CONFIG_SMC_USE_32_BIT
1415 Define this if data bus is 32 bits
1417 CONFIG_SMC_USE_IOFUNCS
1418 Define this to use i/o functions instead of macros
1419 (some hardware wont work with macros)
1421 CONFIG_DRIVER_TI_EMAC
1422 Support for davinci emac
1424 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1425 Define this if you have more then 3 PHYs.
1428 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1430 CONFIG_FTGMAC100_EGIGA
1431 Define this to use GE link update with gigabit PHY.
1432 Define this if FTGMAC100 is connected to gigabit PHY.
1433 If your system has 10/100 PHY only, it might not occur
1434 wrong behavior. Because PHY usually return timeout or
1435 useless data when polling gigabit status and gigabit
1436 control registers. This behavior won't affect the
1437 correctnessof 10/100 link speed update.
1440 Support for SMSC's LAN911x and LAN921x chips
1443 Define this to hold the physical address
1444 of the device (I/O space)
1446 CONFIG_SMC911X_32_BIT
1447 Define this if data bus is 32 bits
1449 CONFIG_SMC911X_16_BIT
1450 Define this if data bus is 16 bits. If your processor
1451 automatically converts one 32 bit word to two 16 bit
1452 words you may also try CONFIG_SMC911X_32_BIT.
1455 Support for Renesas on-chip Ethernet controller
1457 CONFIG_SH_ETHER_USE_PORT
1458 Define the number of ports to be used
1460 CONFIG_SH_ETHER_PHY_ADDR
1461 Define the ETH PHY's address
1463 CONFIG_SH_ETHER_CACHE_WRITEBACK
1464 If this option is set, the driver enables cache flush.
1468 Support for PWM modul on the imx6.
1472 Support TPM devices.
1475 Support for i2c bus TPM devices. Only one device
1476 per system is supported at this time.
1478 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1479 Define the the i2c bus number for the TPM device
1481 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1482 Define the TPM's address on the i2c bus
1484 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1485 Define the burst count bytes upper limit
1487 CONFIG_TPM_ATMEL_TWI
1488 Support for Atmel TWI TPM device. Requires I2C support.
1491 Support for generic parallel port TPM devices. Only one device
1492 per system is supported at this time.
1494 CONFIG_TPM_TIS_BASE_ADDRESS
1495 Base address where the generic TPM device is mapped
1496 to. Contemporary x86 systems usually map it at
1500 Add tpm monitor functions.
1501 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1502 provides monitor access to authorized functions.
1505 Define this to enable the TPM support library which provides
1506 functional interfaces to some TPM commands.
1507 Requires support for a TPM device.
1509 CONFIG_TPM_AUTH_SESSIONS
1510 Define this to enable authorized functions in the TPM library.
1511 Requires CONFIG_TPM and CONFIG_SHA1.
1514 At the moment only the UHCI host controller is
1515 supported (PIP405, MIP405, MPC5200); define
1516 CONFIG_USB_UHCI to enable it.
1517 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1518 and define CONFIG_USB_STORAGE to enable the USB
1521 Supported are USB Keyboards and USB Floppy drives
1523 MPC5200 USB requires additional defines:
1525 for 528 MHz Clock: 0x0001bbbb
1529 for differential drivers: 0x00001000
1530 for single ended drivers: 0x00005000
1531 for differential drivers on PSC3: 0x00000100
1532 for single ended drivers on PSC3: 0x00004100
1533 CONFIG_SYS_USB_EVENT_POLL
1534 May be defined to allow interrupt polling
1535 instead of using asynchronous interrupts
1537 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1538 txfilltuning field in the EHCI controller on reset.
1540 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1541 HW module registers.
1544 Define the below if you wish to use the USB console.
1545 Once firmware is rebuilt from a serial console issue the
1546 command "setenv stdin usbtty; setenv stdout usbtty" and
1547 attach your USB cable. The Unix command "dmesg" should print
1548 it has found a new device. The environment variable usbtty
1549 can be set to gserial or cdc_acm to enable your device to
1550 appear to a USB host as a Linux gserial device or a
1551 Common Device Class Abstract Control Model serial device.
1552 If you select usbtty = gserial you should be able to enumerate
1554 # modprobe usbserial vendor=0xVendorID product=0xProductID
1555 else if using cdc_acm, simply setting the environment
1556 variable usbtty to be cdc_acm should suffice. The following
1557 might be defined in YourBoardName.h
1560 Define this to build a UDC device
1563 Define this to have a tty type of device available to
1564 talk to the UDC device
1567 Define this to enable the high speed support for usb
1568 device and usbtty. If this feature is enabled, a routine
1569 int is_usbd_high_speed(void)
1570 also needs to be defined by the driver to dynamically poll
1571 whether the enumeration has succeded at high speed or full
1574 CONFIG_SYS_CONSOLE_IS_IN_ENV
1575 Define this if you want stdin, stdout &/or stderr to
1579 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1580 Derive USB clock from external clock "blah"
1581 - CONFIG_SYS_USB_EXTC_CLK 0x02
1583 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1584 Derive USB clock from brgclk
1585 - CONFIG_SYS_USB_BRG_CLK 0x04
1587 If you have a USB-IF assigned VendorID then you may wish to
1588 define your own vendor specific values either in BoardName.h
1589 or directly in usbd_vendor_info.h. If you don't define
1590 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1591 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1592 should pretend to be a Linux device to it's target host.
1594 CONFIG_USBD_MANUFACTURER
1595 Define this string as the name of your company for
1596 - CONFIG_USBD_MANUFACTURER "my company"
1598 CONFIG_USBD_PRODUCT_NAME
1599 Define this string as the name of your product
1600 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1602 CONFIG_USBD_VENDORID
1603 Define this as your assigned Vendor ID from the USB
1604 Implementors Forum. This *must* be a genuine Vendor ID
1605 to avoid polluting the USB namespace.
1606 - CONFIG_USBD_VENDORID 0xFFFF
1608 CONFIG_USBD_PRODUCTID
1609 Define this as the unique Product ID
1611 - CONFIG_USBD_PRODUCTID 0xFFFF
1613 - ULPI Layer Support:
1614 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1615 the generic ULPI layer. The generic layer accesses the ULPI PHY
1616 via the platform viewport, so you need both the genric layer and
1617 the viewport enabled. Currently only Chipidea/ARC based
1618 viewport is supported.
1619 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1620 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1621 If your ULPI phy needs a different reference clock than the
1622 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1623 the appropriate value in Hz.
1626 The MMC controller on the Intel PXA is supported. To
1627 enable this define CONFIG_MMC. The MMC can be
1628 accessed from the boot prompt by mapping the device
1629 to physical memory similar to flash. Command line is
1630 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1631 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1634 Support for Renesas on-chip MMCIF controller
1636 CONFIG_SH_MMCIF_ADDR
1637 Define the base address of MMCIF registers
1640 Define the clock frequency for MMCIF
1643 Enable the generic MMC driver
1645 CONFIG_SUPPORT_EMMC_BOOT
1646 Enable some additional features of the eMMC boot partitions.
1648 CONFIG_SUPPORT_EMMC_RPMB
1649 Enable the commands for reading, writing and programming the
1650 key for the Replay Protection Memory Block partition in eMMC.
1652 - USB Device Firmware Update (DFU) class support:
1654 This enables the USB portion of the DFU USB class
1657 This enables the command "dfu" which is used to have
1658 U-Boot create a DFU class device via USB. This command
1659 requires that the "dfu_alt_info" environment variable be
1660 set and define the alt settings to expose to the host.
1663 This enables support for exposing (e)MMC devices via DFU.
1666 This enables support for exposing NAND devices via DFU.
1669 This enables support for exposing RAM via DFU.
1670 Note: DFU spec refer to non-volatile memory usage, but
1671 allow usages beyond the scope of spec - here RAM usage,
1672 one that would help mostly the developer.
1674 CONFIG_SYS_DFU_DATA_BUF_SIZE
1675 Dfu transfer uses a buffer before writing data to the
1676 raw storage device. Make the size (in bytes) of this buffer
1677 configurable. The size of this buffer is also configurable
1678 through the "dfu_bufsiz" environment variable.
1680 CONFIG_SYS_DFU_MAX_FILE_SIZE
1681 When updating files rather than the raw storage device,
1682 we use a static buffer to copy the file into and then write
1683 the buffer once we've been given the whole file. Define
1684 this to the maximum filesize (in bytes) for the buffer.
1685 Default is 4 MiB if undefined.
1687 DFU_DEFAULT_POLL_TIMEOUT
1688 Poll timeout [ms], is the timeout a device can send to the
1689 host. The host must wait for this timeout before sending
1690 a subsequent DFU_GET_STATUS request to the device.
1692 DFU_MANIFEST_POLL_TIMEOUT
1693 Poll timeout [ms], which the device sends to the host when
1694 entering dfuMANIFEST state. Host waits this timeout, before
1695 sending again an USB request to the device.
1697 - USB Device Android Fastboot support:
1699 This enables the command "fastboot" which enables the Android
1700 fastboot mode for the platform's USB device. Fastboot is a USB
1701 protocol for downloading images, flashing and device control
1702 used on Android devices.
1703 See doc/README.android-fastboot for more information.
1705 CONFIG_ANDROID_BOOT_IMAGE
1706 This enables support for booting images which use the Android
1707 image format header.
1709 CONFIG_USB_FASTBOOT_BUF_ADDR
1710 The fastboot protocol requires a large memory buffer for
1711 downloads. Define this to the starting RAM address to use for
1714 CONFIG_USB_FASTBOOT_BUF_SIZE
1715 The fastboot protocol requires a large memory buffer for
1716 downloads. This buffer should be as large as possible for a
1717 platform. Define this to the size available RAM for fastboot.
1719 CONFIG_FASTBOOT_FLASH
1720 The fastboot protocol includes a "flash" command for writing
1721 the downloaded image to a non-volatile storage device. Define
1722 this to enable the "fastboot flash" command.
1724 CONFIG_FASTBOOT_FLASH_MMC_DEV
1725 The fastboot "flash" command requires additional information
1726 regarding the non-volatile storage device. Define this to
1727 the eMMC device that fastboot should use to store the image.
1729 CONFIG_FASTBOOT_GPT_NAME
1730 The fastboot "flash" command supports writing the downloaded
1731 image to the Protective MBR and the Primary GUID Partition
1732 Table. (Additionally, this downloaded image is post-processed
1733 to generate and write the Backup GUID Partition Table.)
1734 This occurs when the specified "partition name" on the
1735 "fastboot flash" command line matches this value.
1736 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1738 - Journaling Flash filesystem support:
1739 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1740 CONFIG_JFFS2_NAND_DEV
1741 Define these for a default partition on a NAND device
1743 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1744 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1745 Define these for a default partition on a NOR device
1747 CONFIG_SYS_JFFS_CUSTOM_PART
1748 Define this to create an own partition. You have to provide a
1749 function struct part_info* jffs2_part_info(int part_num)
1751 If you define only one JFFS2 partition you may also want to
1752 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1753 to disable the command chpart. This is the default when you
1754 have not defined a custom partition
1756 - FAT(File Allocation Table) filesystem write function support:
1759 Define this to enable support for saving memory data as a
1760 file in FAT formatted partition.
1762 This will also enable the command "fatwrite" enabling the
1763 user to write files to FAT.
1765 CBFS (Coreboot Filesystem) support
1768 Define this to enable support for reading from a Coreboot
1769 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1772 - FAT(File Allocation Table) filesystem cluster size:
1773 CONFIG_FS_FAT_MAX_CLUSTSIZE
1775 Define the max cluster size for fat operations else
1776 a default value of 65536 will be defined.
1781 Define this to enable standard (PC-Style) keyboard
1785 Standard PC keyboard driver with US (is default) and
1786 GERMAN key layout (switch via environment 'keymap=de') support.
1787 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1788 for cfb_console. Supports cursor blinking.
1791 Enables a Chrome OS keyboard using the CROS_EC interface.
1792 This uses CROS_EC to communicate with a second microcontroller
1793 which provides key scans on request.
1798 Define this to enable video support (for output to
1801 CONFIG_VIDEO_CT69000
1803 Enable Chips & Technologies 69000 Video chip
1805 CONFIG_VIDEO_SMI_LYNXEM
1806 Enable Silicon Motion SMI 712/710/810 Video chip. The
1807 video output is selected via environment 'videoout'
1808 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1811 For the CT69000 and SMI_LYNXEM drivers, videomode is
1812 selected via environment 'videomode'. Two different ways
1814 - "videomode=num" 'num' is a standard LiLo mode numbers.
1815 Following standard modes are supported (* is default):
1817 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1818 -------------+---------------------------------------------
1819 8 bits | 0x301* 0x303 0x305 0x161 0x307
1820 15 bits | 0x310 0x313 0x316 0x162 0x319
1821 16 bits | 0x311 0x314 0x317 0x163 0x31A
1822 24 bits | 0x312 0x315 0x318 ? 0x31B
1823 -------------+---------------------------------------------
1824 (i.e. setenv videomode 317; saveenv; reset;)
1826 - "videomode=bootargs" all the video parameters are parsed
1827 from the bootargs. (See drivers/video/videomodes.c)
1830 CONFIG_VIDEO_SED13806
1831 Enable Epson SED13806 driver. This driver supports 8bpp
1832 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1833 or CONFIG_VIDEO_SED13806_16BPP
1836 Enable the Freescale DIU video driver. Reference boards for
1837 SOCs that have a DIU should define this macro to enable DIU
1838 support, and should also define these other macros:
1844 CONFIG_VIDEO_SW_CURSOR
1845 CONFIG_VGA_AS_SINGLE_DEVICE
1847 CONFIG_VIDEO_BMP_LOGO
1849 The DIU driver will look for the 'video-mode' environment
1850 variable, and if defined, enable the DIU as a console during
1851 boot. See the documentation file README.video for a
1852 description of this variable.
1856 Enable the VGA video / BIOS for x86. The alternative if you
1857 are using coreboot is to use the coreboot frame buffer
1864 Define this to enable a custom keyboard support.
1865 This simply calls drv_keyboard_init() which must be
1866 defined in your board-specific files.
1867 The only board using this so far is RBC823.
1869 - LCD Support: CONFIG_LCD
1871 Define this to enable LCD support (for output to LCD
1872 display); also select one of the supported displays
1873 by defining one of these:
1877 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1879 CONFIG_NEC_NL6448AC33:
1881 NEC NL6448AC33-18. Active, color, single scan.
1883 CONFIG_NEC_NL6448BC20
1885 NEC NL6448BC20-08. 6.5", 640x480.
1886 Active, color, single scan.
1888 CONFIG_NEC_NL6448BC33_54
1890 NEC NL6448BC33-54. 10.4", 640x480.
1891 Active, color, single scan.
1895 Sharp 320x240. Active, color, single scan.
1896 It isn't 16x9, and I am not sure what it is.
1898 CONFIG_SHARP_LQ64D341
1900 Sharp LQ64D341 display, 640x480.
1901 Active, color, single scan.
1905 HLD1045 display, 640x480.
1906 Active, color, single scan.
1910 Optrex CBL50840-2 NF-FW 99 22 M5
1912 Hitachi LMG6912RPFC-00T
1916 320x240. Black & white.
1918 Normally display is black on white background; define
1919 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1921 CONFIG_LCD_ALIGNMENT
1923 Normally the LCD is page-aligned (typically 4KB). If this is
1924 defined then the LCD will be aligned to this value instead.
1925 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1926 here, since it is cheaper to change data cache settings on
1927 a per-section basis.
1929 CONFIG_CONSOLE_SCROLL_LINES
1931 When the console need to be scrolled, this is the number of
1932 lines to scroll by. It defaults to 1. Increasing this makes
1933 the console jump but can help speed up operation when scrolling
1938 Support drawing of RLE8-compressed bitmaps on the LCD.
1942 Enables an 'i2c edid' command which can read EDID
1943 information over I2C from an attached LCD display.
1945 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1947 If this option is set, the environment is checked for
1948 a variable "splashimage". If found, the usual display
1949 of logo, copyright and system information on the LCD
1950 is suppressed and the BMP image at the address
1951 specified in "splashimage" is loaded instead. The
1952 console is redirected to the "nulldev", too. This
1953 allows for a "silent" boot where a splash screen is
1954 loaded very quickly after power-on.
1956 CONFIG_SPLASHIMAGE_GUARD
1958 If this option is set, then U-Boot will prevent the environment
1959 variable "splashimage" from being set to a problematic address
1960 (see README.displaying-bmps).
1961 This option is useful for targets where, due to alignment
1962 restrictions, an improperly aligned BMP image will cause a data
1963 abort. If you think you will not have problems with unaligned
1964 accesses (for example because your toolchain prevents them)
1965 there is no need to set this option.
1967 CONFIG_SPLASH_SCREEN_ALIGN
1969 If this option is set the splash image can be freely positioned
1970 on the screen. Environment variable "splashpos" specifies the
1971 position as "x,y". If a positive number is given it is used as
1972 number of pixel from left/top. If a negative number is given it
1973 is used as number of pixel from right/bottom. You can also
1974 specify 'm' for centering the image.
1977 setenv splashpos m,m
1978 => image at center of screen
1980 setenv splashpos 30,20
1981 => image at x = 30 and y = 20
1983 setenv splashpos -10,m
1984 => vertically centered image
1985 at x = dspWidth - bmpWidth - 9
1987 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1989 If this option is set, additionally to standard BMP
1990 images, gzipped BMP images can be displayed via the
1991 splashscreen support or the bmp command.
1993 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1995 If this option is set, 8-bit RLE compressed BMP images
1996 can be displayed via the splashscreen support or the
1999 - Do compressing for memory range:
2002 If this option is set, it would use zlib deflate method
2003 to compress the specified memory at its best effort.
2005 - Compression support:
2008 Enabled by default to support gzip compressed images.
2012 If this option is set, support for bzip2 compressed
2013 images is included. If not, only uncompressed and gzip
2014 compressed images are supported.
2016 NOTE: the bzip2 algorithm requires a lot of RAM, so
2017 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2022 If this option is set, support for lzma compressed
2025 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2026 requires an amount of dynamic memory that is given by the
2029 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2031 Where lc and lp stand for, respectively, Literal context bits
2032 and Literal pos bits.
2034 This value is upper-bounded by 14MB in the worst case. Anyway,
2035 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2036 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2037 a very small buffer.
2039 Use the lzmainfo tool to determinate the lc and lp values and
2040 then calculate the amount of needed dynamic memory (ensuring
2041 the appropriate CONFIG_SYS_MALLOC_LEN value).
2045 If this option is set, support for LZO compressed images
2051 The address of PHY on MII bus.
2053 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2055 The clock frequency of the MII bus
2059 If this option is set, support for speed/duplex
2060 detection of gigabit PHY is included.
2062 CONFIG_PHY_RESET_DELAY
2064 Some PHY like Intel LXT971A need extra delay after
2065 reset before any MII register access is possible.
2066 For such PHY, set this option to the usec delay
2067 required. (minimum 300usec for LXT971A)
2069 CONFIG_PHY_CMD_DELAY (ppc4xx)
2071 Some PHY like Intel LXT971A need extra delay after
2072 command issued before MII status register can be read
2082 Define a default value for Ethernet address to use
2083 for the respective Ethernet interface, in case this
2084 is not determined automatically.
2089 Define a default value for the IP address to use for
2090 the default Ethernet interface, in case this is not
2091 determined through e.g. bootp.
2092 (Environment variable "ipaddr")
2094 - Server IP address:
2097 Defines a default value for the IP address of a TFTP
2098 server to contact when using the "tftboot" command.
2099 (Environment variable "serverip")
2101 CONFIG_KEEP_SERVERADDR
2103 Keeps the server's MAC address, in the env 'serveraddr'
2104 for passing to bootargs (like Linux's netconsole option)
2106 - Gateway IP address:
2109 Defines a default value for the IP address of the
2110 default router where packets to other networks are
2112 (Environment variable "gatewayip")
2117 Defines a default value for the subnet mask (or
2118 routing prefix) which is used to determine if an IP
2119 address belongs to the local subnet or needs to be
2120 forwarded through a router.
2121 (Environment variable "netmask")
2123 - Multicast TFTP Mode:
2126 Defines whether you want to support multicast TFTP as per
2127 rfc-2090; for example to work with atftp. Lets lots of targets
2128 tftp down the same boot image concurrently. Note: the Ethernet
2129 driver in use must provide a function: mcast() to join/leave a
2132 - BOOTP Recovery Mode:
2133 CONFIG_BOOTP_RANDOM_DELAY
2135 If you have many targets in a network that try to
2136 boot using BOOTP, you may want to avoid that all
2137 systems send out BOOTP requests at precisely the same
2138 moment (which would happen for instance at recovery
2139 from a power failure, when all systems will try to
2140 boot, thus flooding the BOOTP server. Defining
2141 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2142 inserted before sending out BOOTP requests. The
2143 following delays are inserted then:
2145 1st BOOTP request: delay 0 ... 1 sec
2146 2nd BOOTP request: delay 0 ... 2 sec
2147 3rd BOOTP request: delay 0 ... 4 sec
2149 BOOTP requests: delay 0 ... 8 sec
2151 CONFIG_BOOTP_ID_CACHE_SIZE
2153 BOOTP packets are uniquely identified using a 32-bit ID. The
2154 server will copy the ID from client requests to responses and
2155 U-Boot will use this to determine if it is the destination of
2156 an incoming response. Some servers will check that addresses
2157 aren't in use before handing them out (usually using an ARP
2158 ping) and therefore take up to a few hundred milliseconds to
2159 respond. Network congestion may also influence the time it
2160 takes for a response to make it back to the client. If that
2161 time is too long, U-Boot will retransmit requests. In order
2162 to allow earlier responses to still be accepted after these
2163 retransmissions, U-Boot's BOOTP client keeps a small cache of
2164 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2165 cache. The default is to keep IDs for up to four outstanding
2166 requests. Increasing this will allow U-Boot to accept offers
2167 from a BOOTP client in networks with unusually high latency.
2169 - DHCP Advanced Options:
2170 You can fine tune the DHCP functionality by defining
2171 CONFIG_BOOTP_* symbols:
2173 CONFIG_BOOTP_SUBNETMASK
2174 CONFIG_BOOTP_GATEWAY
2175 CONFIG_BOOTP_HOSTNAME
2176 CONFIG_BOOTP_NISDOMAIN
2177 CONFIG_BOOTP_BOOTPATH
2178 CONFIG_BOOTP_BOOTFILESIZE
2181 CONFIG_BOOTP_SEND_HOSTNAME
2182 CONFIG_BOOTP_NTPSERVER
2183 CONFIG_BOOTP_TIMEOFFSET
2184 CONFIG_BOOTP_VENDOREX
2185 CONFIG_BOOTP_MAY_FAIL
2187 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2188 environment variable, not the BOOTP server.
2190 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2191 after the configured retry count, the call will fail
2192 instead of starting over. This can be used to fail over
2193 to Link-local IP address configuration if the DHCP server
2196 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2197 serverip from a DHCP server, it is possible that more
2198 than one DNS serverip is offered to the client.
2199 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2200 serverip will be stored in the additional environment
2201 variable "dnsip2". The first DNS serverip is always
2202 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2205 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2206 to do a dynamic update of a DNS server. To do this, they
2207 need the hostname of the DHCP requester.
2208 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2209 of the "hostname" environment variable is passed as
2210 option 12 to the DHCP server.
2212 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2214 A 32bit value in microseconds for a delay between
2215 receiving a "DHCP Offer" and sending the "DHCP Request".
2216 This fixes a problem with certain DHCP servers that don't
2217 respond 100% of the time to a "DHCP request". E.g. On an
2218 AT91RM9200 processor running at 180MHz, this delay needed
2219 to be *at least* 15,000 usec before a Windows Server 2003
2220 DHCP server would reply 100% of the time. I recommend at
2221 least 50,000 usec to be safe. The alternative is to hope
2222 that one of the retries will be successful but note that
2223 the DHCP timeout and retry process takes a longer than
2226 - Link-local IP address negotiation:
2227 Negotiate with other link-local clients on the local network
2228 for an address that doesn't require explicit configuration.
2229 This is especially useful if a DHCP server cannot be guaranteed
2230 to exist in all environments that the device must operate.
2232 See doc/README.link-local for more information.
2235 CONFIG_CDP_DEVICE_ID
2237 The device id used in CDP trigger frames.
2239 CONFIG_CDP_DEVICE_ID_PREFIX
2241 A two character string which is prefixed to the MAC address
2246 A printf format string which contains the ascii name of
2247 the port. Normally is set to "eth%d" which sets
2248 eth0 for the first Ethernet, eth1 for the second etc.
2250 CONFIG_CDP_CAPABILITIES
2252 A 32bit integer which indicates the device capabilities;
2253 0x00000010 for a normal host which does not forwards.
2257 An ascii string containing the version of the software.
2261 An ascii string containing the name of the platform.
2265 A 32bit integer sent on the trigger.
2267 CONFIG_CDP_POWER_CONSUMPTION
2269 A 16bit integer containing the power consumption of the
2270 device in .1 of milliwatts.
2272 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2274 A byte containing the id of the VLAN.
2276 - Status LED: CONFIG_STATUS_LED
2278 Several configurations allow to display the current
2279 status using a LED. For instance, the LED will blink
2280 fast while running U-Boot code, stop blinking as
2281 soon as a reply to a BOOTP request was received, and
2282 start blinking slow once the Linux kernel is running
2283 (supported by a status LED driver in the Linux
2284 kernel). Defining CONFIG_STATUS_LED enables this
2290 The status LED can be connected to a GPIO pin.
2291 In such cases, the gpio_led driver can be used as a
2292 status LED backend implementation. Define CONFIG_GPIO_LED
2293 to include the gpio_led driver in the U-Boot binary.
2295 CONFIG_GPIO_LED_INVERTED_TABLE
2296 Some GPIO connected LEDs may have inverted polarity in which
2297 case the GPIO high value corresponds to LED off state and
2298 GPIO low value corresponds to LED on state.
2299 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2300 with a list of GPIO LEDs that have inverted polarity.
2302 - CAN Support: CONFIG_CAN_DRIVER
2304 Defining CONFIG_CAN_DRIVER enables CAN driver support
2305 on those systems that support this (optional)
2306 feature, like the TQM8xxL modules.
2308 - I2C Support: CONFIG_SYS_I2C
2310 This enable the NEW i2c subsystem, and will allow you to use
2311 i2c commands at the u-boot command line (as long as you set
2312 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2313 based realtime clock chips or other i2c devices. See
2314 common/cmd_i2c.c for a description of the command line
2317 ported i2c driver to the new framework:
2318 - drivers/i2c/soft_i2c.c:
2319 - activate first bus with CONFIG_SYS_I2C_SOFT define
2320 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2321 for defining speed and slave address
2322 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2323 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2324 for defining speed and slave address
2325 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2326 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2327 for defining speed and slave address
2328 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2329 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2330 for defining speed and slave address
2332 - drivers/i2c/fsl_i2c.c:
2333 - activate i2c driver with CONFIG_SYS_I2C_FSL
2334 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2335 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2336 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2338 - If your board supports a second fsl i2c bus, define
2339 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2340 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2341 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2344 - drivers/i2c/tegra_i2c.c:
2345 - activate this driver with CONFIG_SYS_I2C_TEGRA
2346 - This driver adds 4 i2c buses with a fix speed from
2347 100000 and the slave addr 0!
2349 - drivers/i2c/ppc4xx_i2c.c
2350 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2351 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2352 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2354 - drivers/i2c/i2c_mxc.c
2355 - activate this driver with CONFIG_SYS_I2C_MXC
2356 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2357 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2358 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2359 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2360 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2361 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2362 If those defines are not set, default value is 100000
2363 for speed, and 0 for slave.
2365 - drivers/i2c/rcar_i2c.c:
2366 - activate this driver with CONFIG_SYS_I2C_RCAR
2367 - This driver adds 4 i2c buses
2369 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2370 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2371 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2372 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2373 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2374 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2375 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2376 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2377 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2379 - drivers/i2c/sh_i2c.c:
2380 - activate this driver with CONFIG_SYS_I2C_SH
2381 - This driver adds from 2 to 5 i2c buses
2383 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2384 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2385 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2386 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2387 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2388 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2389 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2390 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2391 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2392 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2393 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2394 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2395 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2397 - drivers/i2c/omap24xx_i2c.c
2398 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2399 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2400 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2401 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2402 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2403 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2404 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2405 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2406 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2407 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2408 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2410 - drivers/i2c/zynq_i2c.c
2411 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2412 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2413 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2415 - drivers/i2c/s3c24x0_i2c.c:
2416 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2417 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2418 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2419 with a fix speed from 100000 and the slave addr 0!
2421 - drivers/i2c/ihs_i2c.c
2422 - activate this driver with CONFIG_SYS_I2C_IHS
2423 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2424 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2425 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2426 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2427 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2428 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2429 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2430 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2431 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2432 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2433 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2434 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2438 CONFIG_SYS_NUM_I2C_BUSES
2439 Hold the number of i2c buses you want to use. If you
2440 don't use/have i2c muxes on your i2c bus, this
2441 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2444 CONFIG_SYS_I2C_DIRECT_BUS
2445 define this, if you don't use i2c muxes on your hardware.
2446 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2449 CONFIG_SYS_I2C_MAX_HOPS
2450 define how many muxes are maximal consecutively connected
2451 on one i2c bus. If you not use i2c muxes, omit this
2454 CONFIG_SYS_I2C_BUSES
2455 hold a list of buses you want to use, only used if
2456 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2457 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2458 CONFIG_SYS_NUM_I2C_BUSES = 9:
2460 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2461 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2462 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2463 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2464 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2465 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2466 {1, {I2C_NULL_HOP}}, \
2467 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2468 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2472 bus 0 on adapter 0 without a mux
2473 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2474 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2475 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2476 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2477 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2478 bus 6 on adapter 1 without a mux
2479 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2480 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2482 If you do not have i2c muxes on your board, omit this define.
2484 - Legacy I2C Support: CONFIG_HARD_I2C
2486 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2487 provides the following compelling advantages:
2489 - more than one i2c adapter is usable
2490 - approved multibus support
2491 - better i2c mux support
2493 ** Please consider updating your I2C driver now. **
2495 These enable legacy I2C serial bus commands. Defining
2496 CONFIG_HARD_I2C will include the appropriate I2C driver
2497 for the selected CPU.
2499 This will allow you to use i2c commands at the u-boot
2500 command line (as long as you set CONFIG_CMD_I2C in
2501 CONFIG_COMMANDS) and communicate with i2c based realtime
2502 clock chips. See common/cmd_i2c.c for a description of the
2503 command line interface.
2505 CONFIG_HARD_I2C selects a hardware I2C controller.
2507 There are several other quantities that must also be
2508 defined when you define CONFIG_HARD_I2C.
2510 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2511 to be the frequency (in Hz) at which you wish your i2c bus
2512 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2513 the CPU's i2c node address).
2515 Now, the u-boot i2c code for the mpc8xx
2516 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2517 and so its address should therefore be cleared to 0 (See,
2518 eg, MPC823e User's Manual p.16-473). So, set
2519 CONFIG_SYS_I2C_SLAVE to 0.
2521 CONFIG_SYS_I2C_INIT_MPC5XXX
2523 When a board is reset during an i2c bus transfer
2524 chips might think that the current transfer is still
2525 in progress. Reset the slave devices by sending start
2526 commands until the slave device responds.
2528 That's all that's required for CONFIG_HARD_I2C.
2530 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2531 then the following macros need to be defined (examples are
2532 from include/configs/lwmon.h):
2536 (Optional). Any commands necessary to enable the I2C
2537 controller or configure ports.
2539 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2543 (Only for MPC8260 CPU). The I/O port to use (the code
2544 assumes both bits are on the same port). Valid values
2545 are 0..3 for ports A..D.
2549 The code necessary to make the I2C data line active
2550 (driven). If the data line is open collector, this
2553 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2557 The code necessary to make the I2C data line tri-stated
2558 (inactive). If the data line is open collector, this
2561 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2565 Code that returns true if the I2C data line is high,
2568 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2572 If <bit> is true, sets the I2C data line high. If it
2573 is false, it clears it (low).
2575 eg: #define I2C_SDA(bit) \
2576 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2577 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2581 If <bit> is true, sets the I2C clock line high. If it
2582 is false, it clears it (low).
2584 eg: #define I2C_SCL(bit) \
2585 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2586 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2590 This delay is invoked four times per clock cycle so this
2591 controls the rate of data transfer. The data rate thus
2592 is 1 / (I2C_DELAY * 4). Often defined to be something
2595 #define I2C_DELAY udelay(2)
2597 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2599 If your arch supports the generic GPIO framework (asm/gpio.h),
2600 then you may alternatively define the two GPIOs that are to be
2601 used as SCL / SDA. Any of the previous I2C_xxx macros will
2602 have GPIO-based defaults assigned to them as appropriate.
2604 You should define these to the GPIO value as given directly to
2605 the generic GPIO functions.
2607 CONFIG_SYS_I2C_INIT_BOARD
2609 When a board is reset during an i2c bus transfer
2610 chips might think that the current transfer is still
2611 in progress. On some boards it is possible to access
2612 the i2c SCLK line directly, either by using the
2613 processor pin as a GPIO or by having a second pin
2614 connected to the bus. If this option is defined a
2615 custom i2c_init_board() routine in boards/xxx/board.c
2616 is run early in the boot sequence.
2618 CONFIG_SYS_I2C_BOARD_LATE_INIT
2620 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2621 defined a custom i2c_board_late_init() routine in
2622 boards/xxx/board.c is run AFTER the operations in i2c_init()
2623 is completed. This callpoint can be used to unreset i2c bus
2624 using CPU i2c controller register accesses for CPUs whose i2c
2625 controller provide such a method. It is called at the end of
2626 i2c_init() to allow i2c_init operations to setup the i2c bus
2627 controller on the CPU (e.g. setting bus speed & slave address).
2629 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2631 This option enables configuration of bi_iic_fast[] flags
2632 in u-boot bd_info structure based on u-boot environment
2633 variable "i2cfast". (see also i2cfast)
2635 CONFIG_I2C_MULTI_BUS
2637 This option allows the use of multiple I2C buses, each of which
2638 must have a controller. At any point in time, only one bus is
2639 active. To switch to a different bus, use the 'i2c dev' command.
2640 Note that bus numbering is zero-based.
2642 CONFIG_SYS_I2C_NOPROBES
2644 This option specifies a list of I2C devices that will be skipped
2645 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2646 is set, specify a list of bus-device pairs. Otherwise, specify
2647 a 1D array of device addresses
2650 #undef CONFIG_I2C_MULTI_BUS
2651 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2653 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2655 #define CONFIG_I2C_MULTI_BUS
2656 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2658 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2660 CONFIG_SYS_SPD_BUS_NUM
2662 If defined, then this indicates the I2C bus number for DDR SPD.
2663 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2665 CONFIG_SYS_RTC_BUS_NUM
2667 If defined, then this indicates the I2C bus number for the RTC.
2668 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2670 CONFIG_SYS_DTT_BUS_NUM
2672 If defined, then this indicates the I2C bus number for the DTT.
2673 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2675 CONFIG_SYS_I2C_DTT_ADDR:
2677 If defined, specifies the I2C address of the DTT device.
2678 If not defined, then U-Boot uses predefined value for
2679 specified DTT device.
2681 CONFIG_SOFT_I2C_READ_REPEATED_START
2683 defining this will force the i2c_read() function in
2684 the soft_i2c driver to perform an I2C repeated start
2685 between writing the address pointer and reading the
2686 data. If this define is omitted the default behaviour
2687 of doing a stop-start sequence will be used. Most I2C
2688 devices can use either method, but some require one or
2691 - SPI Support: CONFIG_SPI
2693 Enables SPI driver (so far only tested with
2694 SPI EEPROM, also an instance works with Crystal A/D and
2695 D/As on the SACSng board)
2699 Enables the driver for SPI controller on SuperH. Currently
2700 only SH7757 is supported.
2704 Enables extended (16-bit) SPI EEPROM addressing.
2705 (symmetrical to CONFIG_I2C_X)
2709 Enables a software (bit-bang) SPI driver rather than
2710 using hardware support. This is a general purpose
2711 driver that only requires three general I/O port pins
2712 (two outputs, one input) to function. If this is
2713 defined, the board configuration must define several
2714 SPI configuration items (port pins to use, etc). For
2715 an example, see include/configs/sacsng.h.
2719 Enables a hardware SPI driver for general-purpose reads
2720 and writes. As with CONFIG_SOFT_SPI, the board configuration
2721 must define a list of chip-select function pointers.
2722 Currently supported on some MPC8xxx processors. For an
2723 example, see include/configs/mpc8349emds.h.
2727 Enables the driver for the SPI controllers on i.MX and MXC
2728 SoCs. Currently i.MX31/35/51 are supported.
2730 CONFIG_SYS_SPI_MXC_WAIT
2731 Timeout for waiting until spi transfer completed.
2732 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2734 - FPGA Support: CONFIG_FPGA
2736 Enables FPGA subsystem.
2738 CONFIG_FPGA_<vendor>
2740 Enables support for specific chip vendors.
2743 CONFIG_FPGA_<family>
2745 Enables support for FPGA family.
2746 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2750 Specify the number of FPGA devices to support.
2752 CONFIG_CMD_FPGA_LOADMK
2754 Enable support for fpga loadmk command
2756 CONFIG_CMD_FPGA_LOADP
2758 Enable support for fpga loadp command - load partial bitstream
2760 CONFIG_CMD_FPGA_LOADBP
2762 Enable support for fpga loadbp command - load partial bitstream
2765 CONFIG_SYS_FPGA_PROG_FEEDBACK
2767 Enable printing of hash marks during FPGA configuration.
2769 CONFIG_SYS_FPGA_CHECK_BUSY
2771 Enable checks on FPGA configuration interface busy
2772 status by the configuration function. This option
2773 will require a board or device specific function to
2778 If defined, a function that provides delays in the FPGA
2779 configuration driver.
2781 CONFIG_SYS_FPGA_CHECK_CTRLC
2782 Allow Control-C to interrupt FPGA configuration
2784 CONFIG_SYS_FPGA_CHECK_ERROR
2786 Check for configuration errors during FPGA bitfile
2787 loading. For example, abort during Virtex II
2788 configuration if the INIT_B line goes low (which
2789 indicated a CRC error).
2791 CONFIG_SYS_FPGA_WAIT_INIT
2793 Maximum time to wait for the INIT_B line to de-assert
2794 after PROB_B has been de-asserted during a Virtex II
2795 FPGA configuration sequence. The default time is 500
2798 CONFIG_SYS_FPGA_WAIT_BUSY
2800 Maximum time to wait for BUSY to de-assert during
2801 Virtex II FPGA configuration. The default is 5 ms.
2803 CONFIG_SYS_FPGA_WAIT_CONFIG
2805 Time to wait after FPGA configuration. The default is
2808 - Configuration Management:
2811 Some SoCs need special image types (e.g. U-Boot binary
2812 with a special header) as build targets. By defining
2813 CONFIG_BUILD_TARGET in the SoC / board header, this
2814 special image will be automatically built upon calling
2819 If defined, this string will be added to the U-Boot
2820 version information (U_BOOT_VERSION)
2822 - Vendor Parameter Protection:
2824 U-Boot considers the values of the environment
2825 variables "serial#" (Board Serial Number) and
2826 "ethaddr" (Ethernet Address) to be parameters that
2827 are set once by the board vendor / manufacturer, and
2828 protects these variables from casual modification by
2829 the user. Once set, these variables are read-only,
2830 and write or delete attempts are rejected. You can
2831 change this behaviour:
2833 If CONFIG_ENV_OVERWRITE is #defined in your config
2834 file, the write protection for vendor parameters is
2835 completely disabled. Anybody can change or delete
2838 Alternatively, if you #define _both_ CONFIG_ETHADDR
2839 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2840 Ethernet address is installed in the environment,
2841 which can be changed exactly ONCE by the user. [The
2842 serial# is unaffected by this, i. e. it remains
2845 The same can be accomplished in a more flexible way
2846 for any variable by configuring the type of access
2847 to allow for those variables in the ".flags" variable
2848 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2853 Define this variable to enable the reservation of
2854 "protected RAM", i. e. RAM which is not overwritten
2855 by U-Boot. Define CONFIG_PRAM to hold the number of
2856 kB you want to reserve for pRAM. You can overwrite
2857 this default value by defining an environment
2858 variable "pram" to the number of kB you want to
2859 reserve. Note that the board info structure will
2860 still show the full amount of RAM. If pRAM is
2861 reserved, a new environment variable "mem" will
2862 automatically be defined to hold the amount of
2863 remaining RAM in a form that can be passed as boot
2864 argument to Linux, for instance like that:
2866 setenv bootargs ... mem=\${mem}
2869 This way you can tell Linux not to use this memory,
2870 either, which results in a memory region that will
2871 not be affected by reboots.
2873 *WARNING* If your board configuration uses automatic
2874 detection of the RAM size, you must make sure that
2875 this memory test is non-destructive. So far, the
2876 following board configurations are known to be
2879 IVMS8, IVML24, SPD8xx, TQM8xxL,
2880 HERMES, IP860, RPXlite, LWMON,
2883 - Access to physical memory region (> 4GB)
2884 Some basic support is provided for operations on memory not
2885 normally accessible to U-Boot - e.g. some architectures
2886 support access to more than 4GB of memory on 32-bit
2887 machines using physical address extension or similar.
2888 Define CONFIG_PHYSMEM to access this basic support, which
2889 currently only supports clearing the memory.
2894 Define this variable to stop the system in case of a
2895 fatal error, so that you have to reset it manually.
2896 This is probably NOT a good idea for an embedded
2897 system where you want the system to reboot
2898 automatically as fast as possible, but it may be
2899 useful during development since you can try to debug
2900 the conditions that lead to the situation.
2902 CONFIG_NET_RETRY_COUNT
2904 This variable defines the number of retries for
2905 network operations like ARP, RARP, TFTP, or BOOTP
2906 before giving up the operation. If not defined, a
2907 default value of 5 is used.
2911 Timeout waiting for an ARP reply in milliseconds.
2915 Timeout in milliseconds used in NFS protocol.
2916 If you encounter "ERROR: Cannot umount" in nfs command,
2917 try longer timeout such as
2918 #define CONFIG_NFS_TIMEOUT 10000UL
2920 - Command Interpreter:
2921 CONFIG_AUTO_COMPLETE
2923 Enable auto completion of commands using TAB.
2925 CONFIG_SYS_PROMPT_HUSH_PS2
2927 This defines the secondary prompt string, which is
2928 printed when the command interpreter needs more input
2929 to complete a command. Usually "> ".
2933 In the current implementation, the local variables
2934 space and global environment variables space are
2935 separated. Local variables are those you define by
2936 simply typing `name=value'. To access a local
2937 variable later on, you have write `$name' or
2938 `${name}'; to execute the contents of a variable
2939 directly type `$name' at the command prompt.
2941 Global environment variables are those you use
2942 setenv/printenv to work with. To run a command stored
2943 in such a variable, you need to use the run command,
2944 and you must not use the '$' sign to access them.
2946 To store commands and special characters in a
2947 variable, please use double quotation marks
2948 surrounding the whole text of the variable, instead
2949 of the backslashes before semicolons and special
2952 - Command Line Editing and History:
2953 CONFIG_CMDLINE_EDITING
2955 Enable editing and History functions for interactive
2956 command line input operations
2958 - Default Environment:
2959 CONFIG_EXTRA_ENV_SETTINGS
2961 Define this to contain any number of null terminated
2962 strings (variable = value pairs) that will be part of
2963 the default environment compiled into the boot image.
2965 For example, place something like this in your
2966 board's config file:
2968 #define CONFIG_EXTRA_ENV_SETTINGS \
2972 Warning: This method is based on knowledge about the
2973 internal format how the environment is stored by the
2974 U-Boot code. This is NOT an official, exported
2975 interface! Although it is unlikely that this format
2976 will change soon, there is no guarantee either.
2977 You better know what you are doing here.
2979 Note: overly (ab)use of the default environment is
2980 discouraged. Make sure to check other ways to preset
2981 the environment like the "source" command or the
2984 CONFIG_ENV_VARS_UBOOT_CONFIG
2986 Define this in order to add variables describing the
2987 U-Boot build configuration to the default environment.
2988 These will be named arch, cpu, board, vendor, and soc.
2990 Enabling this option will cause the following to be defined:
2998 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3000 Define this in order to add variables describing certain
3001 run-time determined information about the hardware to the
3002 environment. These will be named board_name, board_rev.
3004 CONFIG_DELAY_ENVIRONMENT
3006 Normally the environment is loaded when the board is
3007 initialised so that it is available to U-Boot. This inhibits
3008 that so that the environment is not available until
3009 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3010 this is instead controlled by the value of
3011 /config/load-environment.
3013 - DataFlash Support:
3014 CONFIG_HAS_DATAFLASH
3016 Defining this option enables DataFlash features and
3017 allows to read/write in Dataflash via the standard
3020 - Serial Flash support
3023 Defining this option enables SPI flash commands
3024 'sf probe/read/write/erase/update'.
3026 Usage requires an initial 'probe' to define the serial
3027 flash parameters, followed by read/write/erase/update
3030 The following defaults may be provided by the platform
3031 to handle the common case when only a single serial
3032 flash is present on the system.
3034 CONFIG_SF_DEFAULT_BUS Bus identifier
3035 CONFIG_SF_DEFAULT_CS Chip-select
3036 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3037 CONFIG_SF_DEFAULT_SPEED in Hz
3041 Define this option to include a destructive SPI flash
3044 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3046 Define this option to use the Bank addr/Extended addr
3047 support on SPI flashes which has size > 16Mbytes.
3049 CONFIG_SF_DUAL_FLASH Dual flash memories
3051 Define this option to use dual flash support where two flash
3052 memories can be connected with a given cs line.
3053 Currently Xilinx Zynq qspi supports these type of connections.
3055 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3056 enable the W#/Vpp signal to disable writing to the status
3057 register on ST MICRON flashes like the N25Q128.
3058 The status register write enable/disable bit, combined with
3059 the W#/VPP signal provides hardware data protection for the
3060 device as follows: When the enable/disable bit is set to 1,
3061 and the W#/VPP signal is driven LOW, the status register
3062 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3063 operation will not execute. The only way to exit this
3064 hardware-protected mode is to drive W#/VPP HIGH.
3066 - SystemACE Support:
3069 Adding this option adds support for Xilinx SystemACE
3070 chips attached via some sort of local bus. The address
3071 of the chip must also be defined in the
3072 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3074 #define CONFIG_SYSTEMACE
3075 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3077 When SystemACE support is added, the "ace" device type
3078 becomes available to the fat commands, i.e. fatls.
3080 - TFTP Fixed UDP Port:
3083 If this is defined, the environment variable tftpsrcp
3084 is used to supply the TFTP UDP source port value.
3085 If tftpsrcp isn't defined, the normal pseudo-random port
3086 number generator is used.
3088 Also, the environment variable tftpdstp is used to supply
3089 the TFTP UDP destination port value. If tftpdstp isn't
3090 defined, the normal port 69 is used.
3092 The purpose for tftpsrcp is to allow a TFTP server to
3093 blindly start the TFTP transfer using the pre-configured
3094 target IP address and UDP port. This has the effect of
3095 "punching through" the (Windows XP) firewall, allowing
3096 the remainder of the TFTP transfer to proceed normally.
3097 A better solution is to properly configure the firewall,
3098 but sometimes that is not allowed.
3103 This enables a generic 'hash' command which can produce
3104 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3108 Enable the hash verify command (hash -v). This adds to code
3111 CONFIG_SHA1 - This option enables support of hashing using SHA1
3112 algorithm. The hash is calculated in software.
3113 CONFIG_SHA256 - This option enables support of hashing using
3114 SHA256 algorithm. The hash is calculated in software.
3115 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3116 for SHA1/SHA256 hashing.
3117 This affects the 'hash' command and also the
3118 hash_lookup_algo() function.
3119 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3120 hardware-acceleration for SHA1/SHA256 progressive hashing.
3121 Data can be streamed in a block at a time and the hashing
3122 is performed in hardware.
3124 Note: There is also a sha1sum command, which should perhaps
3125 be deprecated in favour of 'hash sha1'.
3127 - Freescale i.MX specific commands:
3128 CONFIG_CMD_HDMIDETECT
3129 This enables 'hdmidet' command which returns true if an
3130 HDMI monitor is detected. This command is i.MX 6 specific.
3133 This enables the 'bmode' (bootmode) command for forcing
3134 a boot from specific media.
3136 This is useful for forcing the ROM's usb downloader to
3137 activate upon a watchdog reset which is nice when iterating
3138 on U-Boot. Using the reset button or running bmode normal
3139 will set it back to normal. This command currently
3140 supports i.MX53 and i.MX6.
3145 This enables the RSA algorithm used for FIT image verification
3146 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3148 The Modular Exponentiation algorithm in RSA is implemented using
3149 driver model. So CONFIG_DM needs to be enabled by default for this
3150 library to function.
3152 The signing part is build into mkimage regardless of this
3153 option. The software based modular exponentiation is built into
3154 mkimage irrespective of this option.
3156 - bootcount support:
3157 CONFIG_BOOTCOUNT_LIMIT
3159 This enables the bootcounter support, see:
3160 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3163 enable special bootcounter support on at91sam9xe based boards.
3165 enable special bootcounter support on blackfin based boards.
3167 enable special bootcounter support on da850 based boards.
3168 CONFIG_BOOTCOUNT_RAM
3169 enable support for the bootcounter in RAM
3170 CONFIG_BOOTCOUNT_I2C
3171 enable support for the bootcounter on an i2c (like RTC) device.
3172 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3173 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3175 CONFIG_BOOTCOUNT_ALEN = address len
3177 - Show boot progress:
3178 CONFIG_SHOW_BOOT_PROGRESS
3180 Defining this option allows to add some board-
3181 specific code (calling a user-provided function
3182 "show_boot_progress(int)") that enables you to show
3183 the system's boot progress on some display (for
3184 example, some LED's) on your board. At the moment,
3185 the following checkpoints are implemented:
3187 - Detailed boot stage timing
3189 Define this option to get detailed timing of each stage
3190 of the boot process.
3192 CONFIG_BOOTSTAGE_USER_COUNT
3193 This is the number of available user bootstage records.
3194 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3195 a new ID will be allocated from this stash. If you exceed
3196 the limit, recording will stop.
3198 CONFIG_BOOTSTAGE_REPORT
3199 Define this to print a report before boot, similar to this:
3201 Timer summary in microseconds:
3204 3,575,678 3,575,678 board_init_f start
3205 3,575,695 17 arch_cpu_init A9
3206 3,575,777 82 arch_cpu_init done
3207 3,659,598 83,821 board_init_r start
3208 3,910,375 250,777 main_loop
3209 29,916,167 26,005,792 bootm_start
3210 30,361,327 445,160 start_kernel
3212 CONFIG_CMD_BOOTSTAGE
3213 Add a 'bootstage' command which supports printing a report
3214 and un/stashing of bootstage data.
3216 CONFIG_BOOTSTAGE_FDT
3217 Stash the bootstage information in the FDT. A root 'bootstage'
3218 node is created with each bootstage id as a child. Each child
3219 has a 'name' property and either 'mark' containing the
3220 mark time in microsecond, or 'accum' containing the
3221 accumulated time for that bootstage id in microseconds.
3226 name = "board_init_f";
3235 Code in the Linux kernel can find this in /proc/devicetree.
3237 Legacy uImage format:
3240 1 common/cmd_bootm.c before attempting to boot an image
3241 -1 common/cmd_bootm.c Image header has bad magic number
3242 2 common/cmd_bootm.c Image header has correct magic number
3243 -2 common/cmd_bootm.c Image header has bad checksum
3244 3 common/cmd_bootm.c Image header has correct checksum
3245 -3 common/cmd_bootm.c Image data has bad checksum
3246 4 common/cmd_bootm.c Image data has correct checksum
3247 -4 common/cmd_bootm.c Image is for unsupported architecture
3248 5 common/cmd_bootm.c Architecture check OK
3249 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3250 6 common/cmd_bootm.c Image Type check OK
3251 -6 common/cmd_bootm.c gunzip uncompression error
3252 -7 common/cmd_bootm.c Unimplemented compression type
3253 7 common/cmd_bootm.c Uncompression OK
3254 8 common/cmd_bootm.c No uncompress/copy overwrite error
3255 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3257 9 common/image.c Start initial ramdisk verification
3258 -10 common/image.c Ramdisk header has bad magic number
3259 -11 common/image.c Ramdisk header has bad checksum
3260 10 common/image.c Ramdisk header is OK
3261 -12 common/image.c Ramdisk data has bad checksum
3262 11 common/image.c Ramdisk data has correct checksum
3263 12 common/image.c Ramdisk verification complete, start loading
3264 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3265 13 common/image.c Start multifile image verification
3266 14 common/image.c No initial ramdisk, no multifile, continue.
3268 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3270 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3271 -31 post/post.c POST test failed, detected by post_output_backlog()
3272 -32 post/post.c POST test failed, detected by post_run_single()
3274 34 common/cmd_doc.c before loading a Image from a DOC device
3275 -35 common/cmd_doc.c Bad usage of "doc" command
3276 35 common/cmd_doc.c correct usage of "doc" command
3277 -36 common/cmd_doc.c No boot device
3278 36 common/cmd_doc.c correct boot device
3279 -37 common/cmd_doc.c Unknown Chip ID on boot device
3280 37 common/cmd_doc.c correct chip ID found, device available
3281 -38 common/cmd_doc.c Read Error on boot device
3282 38 common/cmd_doc.c reading Image header from DOC device OK
3283 -39 common/cmd_doc.c Image header has bad magic number
3284 39 common/cmd_doc.c Image header has correct magic number
3285 -40 common/cmd_doc.c Error reading Image from DOC device
3286 40 common/cmd_doc.c Image header has correct magic number
3287 41 common/cmd_ide.c before loading a Image from a IDE device
3288 -42 common/cmd_ide.c Bad usage of "ide" command
3289 42 common/cmd_ide.c correct usage of "ide" command
3290 -43 common/cmd_ide.c No boot device
3291 43 common/cmd_ide.c boot device found
3292 -44 common/cmd_ide.c Device not available
3293 44 common/cmd_ide.c Device available
3294 -45 common/cmd_ide.c wrong partition selected
3295 45 common/cmd_ide.c partition selected
3296 -46 common/cmd_ide.c Unknown partition table
3297 46 common/cmd_ide.c valid partition table found
3298 -47 common/cmd_ide.c Invalid partition type
3299 47 common/cmd_ide.c correct partition type
3300 -48 common/cmd_ide.c Error reading Image Header on boot device
3301 48 common/cmd_ide.c reading Image Header from IDE device OK
3302 -49 common/cmd_ide.c Image header has bad magic number
3303 49 common/cmd_ide.c Image header has correct magic number
3304 -50 common/cmd_ide.c Image header has bad checksum
3305 50 common/cmd_ide.c Image header has correct checksum
3306 -51 common/cmd_ide.c Error reading Image from IDE device
3307 51 common/cmd_ide.c reading Image from IDE device OK
3308 52 common/cmd_nand.c before loading a Image from a NAND device
3309 -53 common/cmd_nand.c Bad usage of "nand" command
3310 53 common/cmd_nand.c correct usage of "nand" command
3311 -54 common/cmd_nand.c No boot device
3312 54 common/cmd_nand.c boot device found
3313 -55 common/cmd_nand.c Unknown Chip ID on boot device
3314 55 common/cmd_nand.c correct chip ID found, device available
3315 -56 common/cmd_nand.c Error reading Image Header on boot device
3316 56 common/cmd_nand.c reading Image Header from NAND device OK
3317 -57 common/cmd_nand.c Image header has bad magic number
3318 57 common/cmd_nand.c Image header has correct magic number
3319 -58 common/cmd_nand.c Error reading Image from NAND device
3320 58 common/cmd_nand.c reading Image from NAND device OK
3322 -60 common/env_common.c Environment has a bad CRC, using default
3324 64 net/eth.c starting with Ethernet configuration.
3325 -64 net/eth.c no Ethernet found.
3326 65 net/eth.c Ethernet found.
3328 -80 common/cmd_net.c usage wrong
3329 80 common/cmd_net.c before calling NetLoop()
3330 -81 common/cmd_net.c some error in NetLoop() occurred
3331 81 common/cmd_net.c NetLoop() back without error
3332 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3333 82 common/cmd_net.c trying automatic boot
3334 83 common/cmd_net.c running "source" command
3335 -83 common/cmd_net.c some error in automatic boot or "source" command
3336 84 common/cmd_net.c end without errors
3341 100 common/cmd_bootm.c Kernel FIT Image has correct format
3342 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3343 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3344 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3345 102 common/cmd_bootm.c Kernel unit name specified
3346 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3347 103 common/cmd_bootm.c Found configuration node
3348 104 common/cmd_bootm.c Got kernel subimage node offset
3349 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3350 105 common/cmd_bootm.c Kernel subimage hash verification OK
3351 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3352 106 common/cmd_bootm.c Architecture check OK
3353 -106 common/cmd_bootm.c Kernel subimage has wrong type
3354 107 common/cmd_bootm.c Kernel subimage type OK
3355 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3356 108 common/cmd_bootm.c Got kernel subimage data/size
3357 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3358 -109 common/cmd_bootm.c Can't get kernel subimage type
3359 -110 common/cmd_bootm.c Can't get kernel subimage comp
3360 -111 common/cmd_bootm.c Can't get kernel subimage os
3361 -112 common/cmd_bootm.c Can't get kernel subimage load address
3362 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3364 120 common/image.c Start initial ramdisk verification
3365 -120 common/image.c Ramdisk FIT image has incorrect format
3366 121 common/image.c Ramdisk FIT image has correct format
3367 122 common/image.c No ramdisk subimage unit name, using configuration
3368 -122 common/image.c Can't get configuration for ramdisk subimage
3369 123 common/image.c Ramdisk unit name specified
3370 -124 common/image.c Can't get ramdisk subimage node offset
3371 125 common/image.c Got ramdisk subimage node offset
3372 -125 common/image.c Ramdisk subimage hash verification failed
3373 126 common/image.c Ramdisk subimage hash verification OK
3374 -126 common/image.c Ramdisk subimage for unsupported architecture
3375 127 common/image.c Architecture check OK
3376 -127 common/image.c Can't get ramdisk subimage data/size
3377 128 common/image.c Got ramdisk subimage data/size
3378 129 common/image.c Can't get ramdisk load address
3379 -129 common/image.c Got ramdisk load address
3381 -130 common/cmd_doc.c Incorrect FIT image format
3382 131 common/cmd_doc.c FIT image format OK
3384 -140 common/cmd_ide.c Incorrect FIT image format
3385 141 common/cmd_ide.c FIT image format OK
3387 -150 common/cmd_nand.c Incorrect FIT image format
3388 151 common/cmd_nand.c FIT image format OK
3390 - legacy image format:
3391 CONFIG_IMAGE_FORMAT_LEGACY
3392 enables the legacy image format support in U-Boot.
3395 enabled if CONFIG_FIT_SIGNATURE is not defined.
3397 CONFIG_DISABLE_IMAGE_LEGACY
3398 disable the legacy image format
3400 This define is introduced, as the legacy image format is
3401 enabled per default for backward compatibility.
3403 - FIT image support:
3405 Enable support for the FIT uImage format.
3407 CONFIG_FIT_BEST_MATCH
3408 When no configuration is explicitly selected, default to the
3409 one whose fdt's compatibility field best matches that of
3410 U-Boot itself. A match is considered "best" if it matches the
3411 most specific compatibility entry of U-Boot's fdt's root node.
3412 The order of entries in the configuration's fdt is ignored.
3414 CONFIG_FIT_SIGNATURE
3415 This option enables signature verification of FIT uImages,
3416 using a hash signed and verified using RSA. If
3417 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3418 hashing is available using hardware, RSA library will use it.
3419 See doc/uImage.FIT/signature.txt for more details.
3421 WARNING: When relying on signed FIT images with required
3422 signature check the legacy image format is default
3423 disabled. If a board need legacy image format support
3424 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3426 CONFIG_FIT_DISABLE_SHA256
3427 Supporting SHA256 hashes has quite an impact on binary size.
3428 For constrained systems sha256 hash support can be disabled
3431 - Standalone program support:
3432 CONFIG_STANDALONE_LOAD_ADDR
3434 This option defines a board specific value for the
3435 address where standalone program gets loaded, thus
3436 overwriting the architecture dependent default
3439 - Frame Buffer Address:
3442 Define CONFIG_FB_ADDR if you want to use specific
3443 address for frame buffer. This is typically the case
3444 when using a graphics controller has separate video
3445 memory. U-Boot will then place the frame buffer at
3446 the given address instead of dynamically reserving it
3447 in system RAM by calling lcd_setmem(), which grabs
3448 the memory for the frame buffer depending on the
3449 configured panel size.
3451 Please see board_init_f function.
3453 - Automatic software updates via TFTP server
3455 CONFIG_UPDATE_TFTP_CNT_MAX
3456 CONFIG_UPDATE_TFTP_MSEC_MAX
3458 These options enable and control the auto-update feature;
3459 for a more detailed description refer to doc/README.update.
3461 - MTD Support (mtdparts command, UBI support)
3464 Adds the MTD device infrastructure from the Linux kernel.
3465 Needed for mtdparts command support.
3467 CONFIG_MTD_PARTITIONS
3469 Adds the MTD partitioning infrastructure from the Linux
3470 kernel. Needed for UBI support.
3472 CONFIG_MTD_NAND_VERIFY_WRITE
3473 verify if the written data is correct reread.
3478 Adds commands for interacting with MTD partitions formatted
3479 with the UBI flash translation layer
3481 Requires also defining CONFIG_RBTREE
3483 CONFIG_UBI_SILENCE_MSG
3485 Make the verbose messages from UBI stop printing. This leaves
3486 warnings and errors enabled.
3489 CONFIG_MTD_UBI_WL_THRESHOLD
3490 This parameter defines the maximum difference between the highest
3491 erase counter value and the lowest erase counter value of eraseblocks
3492 of UBI devices. When this threshold is exceeded, UBI starts performing
3493 wear leveling by means of moving data from eraseblock with low erase
3494 counter to eraseblocks with high erase counter.
3496 The default value should be OK for SLC NAND flashes, NOR flashes and
3497 other flashes which have eraseblock life-cycle 100000 or more.
3498 However, in case of MLC NAND flashes which typically have eraseblock
3499 life-cycle less than 10000, the threshold should be lessened (e.g.,
3500 to 128 or 256, although it does not have to be power of 2).
3504 CONFIG_MTD_UBI_BEB_LIMIT
3505 This option specifies the maximum bad physical eraseblocks UBI
3506 expects on the MTD device (per 1024 eraseblocks). If the
3507 underlying flash does not admit of bad eraseblocks (e.g. NOR
3508 flash), this value is ignored.
3510 NAND datasheets often specify the minimum and maximum NVM
3511 (Number of Valid Blocks) for the flashes' endurance lifetime.
3512 The maximum expected bad eraseblocks per 1024 eraseblocks
3513 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3514 which gives 20 for most NANDs (MaxNVB is basically the total
3515 count of eraseblocks on the chip).
3517 To put it differently, if this value is 20, UBI will try to
3518 reserve about 1.9% of physical eraseblocks for bad blocks
3519 handling. And that will be 1.9% of eraseblocks on the entire
3520 NAND chip, not just the MTD partition UBI attaches. This means
3521 that if you have, say, a NAND flash chip admits maximum 40 bad
3522 eraseblocks, and it is split on two MTD partitions of the same
3523 size, UBI will reserve 40 eraseblocks when attaching a
3528 CONFIG_MTD_UBI_FASTMAP
3529 Fastmap is a mechanism which allows attaching an UBI device
3530 in nearly constant time. Instead of scanning the whole MTD device it
3531 only has to locate a checkpoint (called fastmap) on the device.
3532 The on-flash fastmap contains all information needed to attach
3533 the device. Using fastmap makes only sense on large devices where
3534 attaching by scanning takes long. UBI will not automatically install
3535 a fastmap on old images, but you can set the UBI parameter
3536 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3537 that fastmap-enabled images are still usable with UBI implementations
3538 without fastmap support. On typical flash devices the whole fastmap
3539 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3541 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3542 Set this parameter to enable fastmap automatically on images
3549 Adds commands for interacting with UBI volumes formatted as
3550 UBIFS. UBIFS is read-only in u-boot.
3552 Requires UBI support as well as CONFIG_LZO
3554 CONFIG_UBIFS_SILENCE_MSG
3556 Make the verbose messages from UBIFS stop printing. This leaves
3557 warnings and errors enabled.
3561 Enable building of SPL globally.
3564 LDSCRIPT for linking the SPL binary.
3566 CONFIG_SPL_MAX_FOOTPRINT
3567 Maximum size in memory allocated to the SPL, BSS included.
3568 When defined, the linker checks that the actual memory
3569 used by SPL from _start to __bss_end does not exceed it.
3570 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3571 must not be both defined at the same time.
3574 Maximum size of the SPL image (text, data, rodata, and
3575 linker lists sections), BSS excluded.
3576 When defined, the linker checks that the actual size does
3579 CONFIG_SPL_TEXT_BASE
3580 TEXT_BASE for linking the SPL binary.
3582 CONFIG_SPL_RELOC_TEXT_BASE
3583 Address to relocate to. If unspecified, this is equal to
3584 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3586 CONFIG_SPL_BSS_START_ADDR
3587 Link address for the BSS within the SPL binary.
3589 CONFIG_SPL_BSS_MAX_SIZE
3590 Maximum size in memory allocated to the SPL BSS.
3591 When defined, the linker checks that the actual memory used
3592 by SPL from __bss_start to __bss_end does not exceed it.
3593 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3594 must not be both defined at the same time.
3597 Adress of the start of the stack SPL will use
3599 CONFIG_SPL_RELOC_STACK
3600 Adress of the start of the stack SPL will use after
3601 relocation. If unspecified, this is equal to
3604 CONFIG_SYS_SPL_MALLOC_START
3605 Starting address of the malloc pool used in SPL.
3607 CONFIG_SYS_SPL_MALLOC_SIZE
3608 The size of the malloc pool used in SPL.
3610 CONFIG_SPL_FRAMEWORK
3611 Enable the SPL framework under common/. This framework
3612 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3613 NAND loading of the Linux Kernel.
3616 Enable booting directly to an OS from SPL.
3617 See also: doc/README.falcon
3619 CONFIG_SPL_DISPLAY_PRINT
3620 For ARM, enable an optional function to print more information
3621 about the running system.
3623 CONFIG_SPL_INIT_MINIMAL
3624 Arch init code should be built for a very small image
3626 CONFIG_SPL_LIBCOMMON_SUPPORT
3627 Support for common/libcommon.o in SPL binary
3629 CONFIG_SPL_LIBDISK_SUPPORT
3630 Support for disk/libdisk.o in SPL binary
3632 CONFIG_SPL_I2C_SUPPORT
3633 Support for drivers/i2c/libi2c.o in SPL binary
3635 CONFIG_SPL_GPIO_SUPPORT
3636 Support for drivers/gpio/libgpio.o in SPL binary
3638 CONFIG_SPL_MMC_SUPPORT
3639 Support for drivers/mmc/libmmc.o in SPL binary
3641 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3642 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3643 Address and partition on the MMC to load U-Boot from
3644 when the MMC is being used in raw mode.
3646 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3647 Partition on the MMC to load U-Boot from when the MMC is being
3650 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3651 Sector to load kernel uImage from when MMC is being
3652 used in raw mode (for Falcon mode)
3654 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3655 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3656 Sector and number of sectors to load kernel argument
3657 parameters from when MMC is being used in raw mode
3660 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3661 Partition on the MMC to load U-Boot from when the MMC is being
3664 CONFIG_SPL_FAT_SUPPORT
3665 Support for fs/fat/libfat.o in SPL binary
3667 CONFIG_SPL_EXT_SUPPORT
3668 Support for EXT filesystem in SPL binary
3670 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3671 Filename to read to load U-Boot when reading from filesystem
3673 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3674 Filename to read to load kernel uImage when reading
3675 from filesystem (for Falcon mode)
3677 CONFIG_SPL_FS_LOAD_ARGS_NAME
3678 Filename to read to load kernel argument parameters
3679 when reading from filesystem (for Falcon mode)
3681 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3682 Set this for NAND SPL on PPC mpc83xx targets, so that
3683 start.S waits for the rest of the SPL to load before
3684 continuing (the hardware starts execution after just
3685 loading the first page rather than the full 4K).
3687 CONFIG_SPL_SKIP_RELOCATE
3688 Avoid SPL relocation
3690 CONFIG_SPL_NAND_BASE
3691 Include nand_base.c in the SPL. Requires
3692 CONFIG_SPL_NAND_DRIVERS.
3694 CONFIG_SPL_NAND_DRIVERS
3695 SPL uses normal NAND drivers, not minimal drivers.
3698 Include standard software ECC in the SPL
3700 CONFIG_SPL_NAND_SIMPLE
3701 Support for NAND boot using simple NAND drivers that
3702 expose the cmd_ctrl() interface.
3704 CONFIG_SPL_MTD_SUPPORT
3705 Support for the MTD subsystem within SPL. Useful for
3706 environment on NAND support within SPL.
3708 CONFIG_SPL_NAND_RAW_ONLY
3709 Support to boot only raw u-boot.bin images. Use this only
3710 if you need to save space.
3712 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3713 Set for the SPL on PPC mpc8xxx targets, support for
3714 drivers/ddr/fsl/libddr.o in SPL binary.
3716 CONFIG_SPL_COMMON_INIT_DDR
3717 Set for common ddr init with serial presence detect in
3720 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3721 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3722 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3723 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3724 CONFIG_SYS_NAND_ECCBYTES
3725 Defines the size and behavior of the NAND that SPL uses
3728 CONFIG_SPL_NAND_BOOT
3729 Add support NAND boot
3731 CONFIG_SYS_NAND_U_BOOT_OFFS
3732 Location in NAND to read U-Boot from
3734 CONFIG_SYS_NAND_U_BOOT_DST
3735 Location in memory to load U-Boot to
3737 CONFIG_SYS_NAND_U_BOOT_SIZE
3738 Size of image to load
3740 CONFIG_SYS_NAND_U_BOOT_START
3741 Entry point in loaded image to jump to
3743 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3744 Define this if you need to first read the OOB and then the
3745 data. This is used, for example, on davinci platforms.
3747 CONFIG_SPL_OMAP3_ID_NAND
3748 Support for an OMAP3-specific set of functions to return the
3749 ID and MFR of the first attached NAND chip, if present.
3751 CONFIG_SPL_SERIAL_SUPPORT
3752 Support for drivers/serial/libserial.o in SPL binary
3754 CONFIG_SPL_SPI_FLASH_SUPPORT
3755 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3757 CONFIG_SPL_SPI_SUPPORT
3758 Support for drivers/spi/libspi.o in SPL binary
3760 CONFIG_SPL_RAM_DEVICE
3761 Support for running image already present in ram, in SPL binary
3763 CONFIG_SPL_LIBGENERIC_SUPPORT
3764 Support for lib/libgeneric.o in SPL binary
3766 CONFIG_SPL_ENV_SUPPORT
3767 Support for the environment operating in SPL binary
3769 CONFIG_SPL_NET_SUPPORT
3770 Support for the net/libnet.o in SPL binary.
3771 It conflicts with SPL env from storage medium specified by
3772 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3775 Image offset to which the SPL should be padded before appending
3776 the SPL payload. By default, this is defined as
3777 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3778 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3779 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3782 Final target image containing SPL and payload. Some SPLs
3783 use an arch-specific makefile fragment instead, for
3784 example if more than one image needs to be produced.
3786 CONFIG_FIT_SPL_PRINT
3787 Printing information about a FIT image adds quite a bit of
3788 code to SPL. So this is normally disabled in SPL. Use this
3789 option to re-enable it. This will affect the output of the
3790 bootm command when booting a FIT image.
3794 Enable building of TPL globally.
3797 Image offset to which the TPL should be padded before appending
3798 the TPL payload. By default, this is defined as
3799 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3800 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3801 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3806 [so far only for SMDK2400 boards]
3808 - Modem support enable:
3809 CONFIG_MODEM_SUPPORT
3811 - RTS/CTS Flow control enable:
3814 - Modem debug support:
3815 CONFIG_MODEM_SUPPORT_DEBUG
3817 Enables debugging stuff (char screen[1024], dbg())
3818 for modem support. Useful only with BDI2000.
3820 - Interrupt support (PPC):
3822 There are common interrupt_init() and timer_interrupt()
3823 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3824 for CPU specific initialization. interrupt_init_cpu()
3825 should set decrementer_count to appropriate value. If
3826 CPU resets decrementer automatically after interrupt
3827 (ppc4xx) it should set decrementer_count to zero.
3828 timer_interrupt() calls timer_interrupt_cpu() for CPU
3829 specific handling. If board has watchdog / status_led
3830 / other_activity_monitor it works automatically from
3831 general timer_interrupt().
3835 In the target system modem support is enabled when a
3836 specific key (key combination) is pressed during
3837 power-on. Otherwise U-Boot will boot normally
3838 (autoboot). The key_pressed() function is called from
3839 board_init(). Currently key_pressed() is a dummy
3840 function, returning 1 and thus enabling modem
3843 If there are no modem init strings in the
3844 environment, U-Boot proceed to autoboot; the
3845 previous output (banner, info printfs) will be
3848 See also: doc/README.Modem
3850 Board initialization settings:
3851 ------------------------------
3853 During Initialization u-boot calls a number of board specific functions
3854 to allow the preparation of board specific prerequisites, e.g. pin setup
3855 before drivers are initialized. To enable these callbacks the
3856 following configuration macros have to be defined. Currently this is
3857 architecture specific, so please check arch/your_architecture/lib/board.c
3858 typically in board_init_f() and board_init_r().
3860 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3861 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3862 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3863 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3865 Configuration Settings:
3866 -----------------------
3868 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3869 Optionally it can be defined to support 64-bit memory commands.
3871 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3872 undefine this when you're short of memory.
3874 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3875 width of the commands listed in the 'help' command output.
3877 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3878 prompt for user input.
3880 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3882 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3884 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3886 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3887 the application (usually a Linux kernel) when it is
3890 - CONFIG_SYS_BAUDRATE_TABLE:
3891 List of legal baudrate settings for this board.
3893 - CONFIG_SYS_CONSOLE_INFO_QUIET
3894 Suppress display of console information at boot.
3896 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3897 If the board specific function
3898 extern int overwrite_console (void);
3899 returns 1, the stdin, stderr and stdout are switched to the
3900 serial port, else the settings in the environment are used.
3902 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3903 Enable the call to overwrite_console().
3905 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3906 Enable overwrite of previous console environment settings.
3908 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3909 Begin and End addresses of the area used by the
3912 - CONFIG_SYS_ALT_MEMTEST:
3913 Enable an alternate, more extensive memory test.
3915 - CONFIG_SYS_MEMTEST_SCRATCH:
3916 Scratch address used by the alternate memory test
3917 You only need to set this if address zero isn't writeable
3919 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3920 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3921 this specified memory area will get subtracted from the top
3922 (end) of RAM and won't get "touched" at all by U-Boot. By
3923 fixing up gd->ram_size the Linux kernel should gets passed
3924 the now "corrected" memory size and won't touch it either.
3925 This should work for arch/ppc and arch/powerpc. Only Linux
3926 board ports in arch/powerpc with bootwrapper support that
3927 recalculate the memory size from the SDRAM controller setup
3928 will have to get fixed in Linux additionally.
3930 This option can be used as a workaround for the 440EPx/GRx
3931 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3934 WARNING: Please make sure that this value is a multiple of
3935 the Linux page size (normally 4k). If this is not the case,
3936 then the end address of the Linux memory will be located at a
3937 non page size aligned address and this could cause major
3940 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3941 Enable temporary baudrate change while serial download
3943 - CONFIG_SYS_SDRAM_BASE:
3944 Physical start address of SDRAM. _Must_ be 0 here.
3946 - CONFIG_SYS_MBIO_BASE:
3947 Physical start address of Motherboard I/O (if using a
3950 - CONFIG_SYS_FLASH_BASE:
3951 Physical start address of Flash memory.
3953 - CONFIG_SYS_MONITOR_BASE:
3954 Physical start address of boot monitor code (set by
3955 make config files to be same as the text base address
3956 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3957 CONFIG_SYS_FLASH_BASE when booting from flash.
3959 - CONFIG_SYS_MONITOR_LEN:
3960 Size of memory reserved for monitor code, used to
3961 determine _at_compile_time_ (!) if the environment is
3962 embedded within the U-Boot image, or in a separate
3965 - CONFIG_SYS_MALLOC_LEN:
3966 Size of DRAM reserved for malloc() use.
3968 - CONFIG_SYS_MALLOC_F_LEN
3969 Size of the malloc() pool for use before relocation. If
3970 this is defined, then a very simple malloc() implementation
3971 will become available before relocation. The address is just
3972 below the global data, and the stack is moved down to make
3975 This feature allocates regions with increasing addresses
3976 within the region. calloc() is supported, but realloc()
3977 is not available. free() is supported but does nothing.
3978 The memory will be freed (or in fact just forgotten) when
3979 U-Boot relocates itself.
3981 Pre-relocation malloc() is only supported on ARM and sandbox
3982 at present but is fairly easy to enable for other archs.
3984 - CONFIG_SYS_MALLOC_SIMPLE
3985 Provides a simple and small malloc() and calloc() for those
3986 boards which do not use the full malloc in SPL (which is
3987 enabled with CONFIG_SYS_SPL_MALLOC_START).
3989 - CONFIG_SYS_NONCACHED_MEMORY:
3990 Size of non-cached memory area. This area of memory will be
3991 typically located right below the malloc() area and mapped
3992 uncached in the MMU. This is useful for drivers that would
3993 otherwise require a lot of explicit cache maintenance. For
3994 some drivers it's also impossible to properly maintain the
3995 cache. For example if the regions that need to be flushed
3996 are not a multiple of the cache-line size, *and* padding
3997 cannot be allocated between the regions to align them (i.e.
3998 if the HW requires a contiguous array of regions, and the
3999 size of each region is not cache-aligned), then a flush of
4000 one region may result in overwriting data that hardware has
4001 written to another region in the same cache-line. This can
4002 happen for example in network drivers where descriptors for
4003 buffers are typically smaller than the CPU cache-line (e.g.
4004 16 bytes vs. 32 or 64 bytes).
4006 Non-cached memory is only supported on 32-bit ARM at present.
4008 - CONFIG_SYS_BOOTM_LEN:
4009 Normally compressed uImages are limited to an
4010 uncompressed size of 8 MBytes. If this is not enough,
4011 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4012 to adjust this setting to your needs.
4014 - CONFIG_SYS_BOOTMAPSZ:
4015 Maximum size of memory mapped by the startup code of
4016 the Linux kernel; all data that must be processed by
4017 the Linux kernel (bd_info, boot arguments, FDT blob if
4018 used) must be put below this limit, unless "bootm_low"
4019 environment variable is defined and non-zero. In such case
4020 all data for the Linux kernel must be between "bootm_low"
4021 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4022 variable "bootm_mapsize" will override the value of
4023 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4024 then the value in "bootm_size" will be used instead.
4026 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4027 Enable initrd_high functionality. If defined then the
4028 initrd_high feature is enabled and the bootm ramdisk subcommand
4031 - CONFIG_SYS_BOOT_GET_CMDLINE:
4032 Enables allocating and saving kernel cmdline in space between
4033 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4035 - CONFIG_SYS_BOOT_GET_KBD:
4036 Enables allocating and saving a kernel copy of the bd_info in
4037 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4039 - CONFIG_SYS_MAX_FLASH_BANKS:
4040 Max number of Flash memory banks
4042 - CONFIG_SYS_MAX_FLASH_SECT:
4043 Max number of sectors on a Flash chip
4045 - CONFIG_SYS_FLASH_ERASE_TOUT:
4046 Timeout for Flash erase operations (in ms)
4048 - CONFIG_SYS_FLASH_WRITE_TOUT:
4049 Timeout for Flash write operations (in ms)
4051 - CONFIG_SYS_FLASH_LOCK_TOUT
4052 Timeout for Flash set sector lock bit operation (in ms)
4054 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4055 Timeout for Flash clear lock bits operation (in ms)
4057 - CONFIG_SYS_FLASH_PROTECTION
4058 If defined, hardware flash sectors protection is used
4059 instead of U-Boot software protection.
4061 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4063 Enable TFTP transfers directly to flash memory;
4064 without this option such a download has to be
4065 performed in two steps: (1) download to RAM, and (2)
4066 copy from RAM to flash.
4068 The two-step approach is usually more reliable, since
4069 you can check if the download worked before you erase
4070 the flash, but in some situations (when system RAM is
4071 too limited to allow for a temporary copy of the
4072 downloaded image) this option may be very useful.
4074 - CONFIG_SYS_FLASH_CFI:
4075 Define if the flash driver uses extra elements in the
4076 common flash structure for storing flash geometry.
4078 - CONFIG_FLASH_CFI_DRIVER
4079 This option also enables the building of the cfi_flash driver
4080 in the drivers directory
4082 - CONFIG_FLASH_CFI_MTD
4083 This option enables the building of the cfi_mtd driver
4084 in the drivers directory. The driver exports CFI flash
4087 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4088 Use buffered writes to flash.
4090 - CONFIG_FLASH_SPANSION_S29WS_N
4091 s29ws-n MirrorBit flash has non-standard addresses for buffered
4094 - CONFIG_SYS_FLASH_QUIET_TEST
4095 If this option is defined, the common CFI flash doesn't
4096 print it's warning upon not recognized FLASH banks. This
4097 is useful, if some of the configured banks are only
4098 optionally available.
4100 - CONFIG_FLASH_SHOW_PROGRESS
4101 If defined (must be an integer), print out countdown
4102 digits and dots. Recommended value: 45 (9..1) for 80
4103 column displays, 15 (3..1) for 40 column displays.
4105 - CONFIG_FLASH_VERIFY
4106 If defined, the content of the flash (destination) is compared
4107 against the source after the write operation. An error message
4108 will be printed when the contents are not identical.
4109 Please note that this option is useless in nearly all cases,
4110 since such flash programming errors usually are detected earlier
4111 while unprotecting/erasing/programming. Please only enable
4112 this option if you really know what you are doing.
4114 - CONFIG_SYS_RX_ETH_BUFFER:
4115 Defines the number of Ethernet receive buffers. On some
4116 Ethernet controllers it is recommended to set this value
4117 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4118 buffers can be full shortly after enabling the interface
4119 on high Ethernet traffic.
4120 Defaults to 4 if not defined.
4122 - CONFIG_ENV_MAX_ENTRIES
4124 Maximum number of entries in the hash table that is used
4125 internally to store the environment settings. The default
4126 setting is supposed to be generous and should work in most
4127 cases. This setting can be used to tune behaviour; see
4128 lib/hashtable.c for details.
4130 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4131 - CONFIG_ENV_FLAGS_LIST_STATIC
4132 Enable validation of the values given to environment variables when
4133 calling env set. Variables can be restricted to only decimal,
4134 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4135 the variables can also be restricted to IP address or MAC address.
4137 The format of the list is:
4138 type_attribute = [s|d|x|b|i|m]
4139 access_attribute = [a|r|o|c]
4140 attributes = type_attribute[access_attribute]
4141 entry = variable_name[:attributes]
4144 The type attributes are:
4145 s - String (default)
4148 b - Boolean ([1yYtT|0nNfF])
4152 The access attributes are:
4158 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4159 Define this to a list (string) to define the ".flags"
4160 environment variable in the default or embedded environment.
4162 - CONFIG_ENV_FLAGS_LIST_STATIC
4163 Define this to a list (string) to define validation that
4164 should be done if an entry is not found in the ".flags"
4165 environment variable. To override a setting in the static
4166 list, simply add an entry for the same variable name to the
4169 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4170 If defined, don't allow the -f switch to env set override variable
4173 - CONFIG_SYS_GENERIC_BOARD
4174 This selects the architecture-generic board system instead of the
4175 architecture-specific board files. It is intended to move boards
4176 to this new framework over time. Defining this will disable the
4177 arch/foo/lib/board.c file and use common/board_f.c and
4178 common/board_r.c instead. To use this option your architecture
4179 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4180 its config.mk file). If you find problems enabling this option on
4181 your board please report the problem and send patches!
4183 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4184 This is set by OMAP boards for the max time that reset should
4185 be asserted. See doc/README.omap-reset-time for details on how
4186 the value can be calculated on a given board.
4189 If stdint.h is available with your toolchain you can define this
4190 option to enable it. You can provide option 'USE_STDINT=1' when
4191 building U-Boot to enable this.
4193 The following definitions that deal with the placement and management
4194 of environment data (variable area); in general, we support the
4195 following configurations:
4197 - CONFIG_BUILD_ENVCRC:
4199 Builds up envcrc with the target environment so that external utils
4200 may easily extract it and embed it in final U-Boot images.
4202 - CONFIG_ENV_IS_IN_FLASH:
4204 Define this if the environment is in flash memory.
4206 a) The environment occupies one whole flash sector, which is
4207 "embedded" in the text segment with the U-Boot code. This
4208 happens usually with "bottom boot sector" or "top boot
4209 sector" type flash chips, which have several smaller
4210 sectors at the start or the end. For instance, such a
4211 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4212 such a case you would place the environment in one of the
4213 4 kB sectors - with U-Boot code before and after it. With
4214 "top boot sector" type flash chips, you would put the
4215 environment in one of the last sectors, leaving a gap
4216 between U-Boot and the environment.
4218 - CONFIG_ENV_OFFSET:
4220 Offset of environment data (variable area) to the
4221 beginning of flash memory; for instance, with bottom boot
4222 type flash chips the second sector can be used: the offset
4223 for this sector is given here.
4225 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4229 This is just another way to specify the start address of
4230 the flash sector containing the environment (instead of
4233 - CONFIG_ENV_SECT_SIZE:
4235 Size of the sector containing the environment.
4238 b) Sometimes flash chips have few, equal sized, BIG sectors.
4239 In such a case you don't want to spend a whole sector for
4244 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4245 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4246 of this flash sector for the environment. This saves
4247 memory for the RAM copy of the environment.
4249 It may also save flash memory if you decide to use this
4250 when your environment is "embedded" within U-Boot code,
4251 since then the remainder of the flash sector could be used
4252 for U-Boot code. It should be pointed out that this is
4253 STRONGLY DISCOURAGED from a robustness point of view:
4254 updating the environment in flash makes it always
4255 necessary to erase the WHOLE sector. If something goes
4256 wrong before the contents has been restored from a copy in
4257 RAM, your target system will be dead.
4259 - CONFIG_ENV_ADDR_REDUND
4260 CONFIG_ENV_SIZE_REDUND
4262 These settings describe a second storage area used to hold
4263 a redundant copy of the environment data, so that there is
4264 a valid backup copy in case there is a power failure during
4265 a "saveenv" operation.
4267 BE CAREFUL! Any changes to the flash layout, and some changes to the
4268 source code will make it necessary to adapt <board>/u-boot.lds*
4272 - CONFIG_ENV_IS_IN_NVRAM:
4274 Define this if you have some non-volatile memory device
4275 (NVRAM, battery buffered SRAM) which you want to use for the
4281 These two #defines are used to determine the memory area you
4282 want to use for environment. It is assumed that this memory
4283 can just be read and written to, without any special
4286 BE CAREFUL! The first access to the environment happens quite early
4287 in U-Boot initialization (when we try to get the setting of for the
4288 console baudrate). You *MUST* have mapped your NVRAM area then, or
4291 Please note that even with NVRAM we still use a copy of the
4292 environment in RAM: we could work on NVRAM directly, but we want to
4293 keep settings there always unmodified except somebody uses "saveenv"
4294 to save the current settings.
4297 - CONFIG_ENV_IS_IN_EEPROM:
4299 Use this if you have an EEPROM or similar serial access
4300 device and a driver for it.
4302 - CONFIG_ENV_OFFSET:
4305 These two #defines specify the offset and size of the
4306 environment area within the total memory of your EEPROM.
4308 - CONFIG_SYS_I2C_EEPROM_ADDR:
4309 If defined, specified the chip address of the EEPROM device.
4310 The default address is zero.
4312 - CONFIG_SYS_I2C_EEPROM_BUS:
4313 If defined, specified the i2c bus of the EEPROM device.
4315 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4316 If defined, the number of bits used to address bytes in a
4317 single page in the EEPROM device. A 64 byte page, for example
4318 would require six bits.
4320 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4321 If defined, the number of milliseconds to delay between
4322 page writes. The default is zero milliseconds.
4324 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4325 The length in bytes of the EEPROM memory array address. Note
4326 that this is NOT the chip address length!
4328 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4329 EEPROM chips that implement "address overflow" are ones
4330 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4331 address and the extra bits end up in the "chip address" bit
4332 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4335 Note that we consider the length of the address field to
4336 still be one byte because the extra address bits are hidden
4337 in the chip address.
4339 - CONFIG_SYS_EEPROM_SIZE:
4340 The size in bytes of the EEPROM device.
4342 - CONFIG_ENV_EEPROM_IS_ON_I2C
4343 define this, if you have I2C and SPI activated, and your
4344 EEPROM, which holds the environment, is on the I2C bus.
4346 - CONFIG_I2C_ENV_EEPROM_BUS
4347 if you have an Environment on an EEPROM reached over
4348 I2C muxes, you can define here, how to reach this
4349 EEPROM. For example:
4351 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4353 EEPROM which holds the environment, is reached over
4354 a pca9547 i2c mux with address 0x70, channel 3.
4356 - CONFIG_ENV_IS_IN_DATAFLASH:
4358 Define this if you have a DataFlash memory device which you
4359 want to use for the environment.
4361 - CONFIG_ENV_OFFSET:
4365 These three #defines specify the offset and size of the
4366 environment area within the total memory of your DataFlash placed
4367 at the specified address.
4369 - CONFIG_ENV_IS_IN_SPI_FLASH:
4371 Define this if you have a SPI Flash memory device which you
4372 want to use for the environment.
4374 - CONFIG_ENV_OFFSET:
4377 These two #defines specify the offset and size of the
4378 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4379 aligned to an erase sector boundary.
4381 - CONFIG_ENV_SECT_SIZE:
4383 Define the SPI flash's sector size.
4385 - CONFIG_ENV_OFFSET_REDUND (optional):
4387 This setting describes a second storage area of CONFIG_ENV_SIZE
4388 size used to hold a redundant copy of the environment data, so
4389 that there is a valid backup copy in case there is a power failure
4390 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4391 aligned to an erase sector boundary.
4393 - CONFIG_ENV_SPI_BUS (optional):
4394 - CONFIG_ENV_SPI_CS (optional):
4396 Define the SPI bus and chip select. If not defined they will be 0.
4398 - CONFIG_ENV_SPI_MAX_HZ (optional):
4400 Define the SPI max work clock. If not defined then use 1MHz.
4402 - CONFIG_ENV_SPI_MODE (optional):
4404 Define the SPI work mode. If not defined then use SPI_MODE_3.
4406 - CONFIG_ENV_IS_IN_REMOTE:
4408 Define this if you have a remote memory space which you
4409 want to use for the local device's environment.
4414 These two #defines specify the address and size of the
4415 environment area within the remote memory space. The
4416 local device can get the environment from remote memory
4417 space by SRIO or PCIE links.
4419 BE CAREFUL! For some special cases, the local device can not use
4420 "saveenv" command. For example, the local device will get the
4421 environment stored in a remote NOR flash by SRIO or PCIE link,
4422 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4424 - CONFIG_ENV_IS_IN_NAND:
4426 Define this if you have a NAND device which you want to use
4427 for the environment.
4429 - CONFIG_ENV_OFFSET:
4432 These two #defines specify the offset and size of the environment
4433 area within the first NAND device. CONFIG_ENV_OFFSET must be
4434 aligned to an erase block boundary.
4436 - CONFIG_ENV_OFFSET_REDUND (optional):
4438 This setting describes a second storage area of CONFIG_ENV_SIZE
4439 size used to hold a redundant copy of the environment data, so
4440 that there is a valid backup copy in case there is a power failure
4441 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4442 aligned to an erase block boundary.
4444 - CONFIG_ENV_RANGE (optional):
4446 Specifies the length of the region in which the environment
4447 can be written. This should be a multiple of the NAND device's
4448 block size. Specifying a range with more erase blocks than
4449 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4450 the range to be avoided.
4452 - CONFIG_ENV_OFFSET_OOB (optional):
4454 Enables support for dynamically retrieving the offset of the
4455 environment from block zero's out-of-band data. The
4456 "nand env.oob" command can be used to record this offset.
4457 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4458 using CONFIG_ENV_OFFSET_OOB.
4460 - CONFIG_NAND_ENV_DST
4462 Defines address in RAM to which the nand_spl code should copy the
4463 environment. If redundant environment is used, it will be copied to
4464 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4466 - CONFIG_ENV_IS_IN_UBI:
4468 Define this if you have an UBI volume that you want to use for the
4469 environment. This has the benefit of wear-leveling the environment
4470 accesses, which is important on NAND.
4472 - CONFIG_ENV_UBI_PART:
4474 Define this to a string that is the mtd partition containing the UBI.
4476 - CONFIG_ENV_UBI_VOLUME:
4478 Define this to the name of the volume that you want to store the
4481 - CONFIG_ENV_UBI_VOLUME_REDUND:
4483 Define this to the name of another volume to store a second copy of
4484 the environment in. This will enable redundant environments in UBI.
4485 It is assumed that both volumes are in the same MTD partition.
4487 - CONFIG_UBI_SILENCE_MSG
4488 - CONFIG_UBIFS_SILENCE_MSG
4490 You will probably want to define these to avoid a really noisy system
4491 when storing the env in UBI.
4493 - CONFIG_ENV_IS_IN_FAT:
4494 Define this if you want to use the FAT file system for the environment.
4496 - FAT_ENV_INTERFACE:
4498 Define this to a string that is the name of the block device.
4500 - FAT_ENV_DEV_AND_PART:
4502 Define this to a string to specify the partition of the device. It can
4505 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4506 - "D:P": device D partition P. Error occurs if device D has no
4509 - "D" or "D:": device D partition 1 if device D has partition
4510 table, or the whole device D if has no partition
4512 - "D:auto": first partition in device D with bootable flag set.
4513 If none, first valid partition in device D. If no
4514 partition table then means device D.
4518 It's a string of the FAT file name. This file use to store the
4522 This should be defined. Otherwise it cannot save the environment file.
4524 - CONFIG_ENV_IS_IN_MMC:
4526 Define this if you have an MMC device which you want to use for the
4529 - CONFIG_SYS_MMC_ENV_DEV:
4531 Specifies which MMC device the environment is stored in.
4533 - CONFIG_SYS_MMC_ENV_PART (optional):
4535 Specifies which MMC partition the environment is stored in. If not
4536 set, defaults to partition 0, the user area. Common values might be
4537 1 (first MMC boot partition), 2 (second MMC boot partition).
4539 - CONFIG_ENV_OFFSET:
4542 These two #defines specify the offset and size of the environment
4543 area within the specified MMC device.
4545 If offset is positive (the usual case), it is treated as relative to
4546 the start of the MMC partition. If offset is negative, it is treated
4547 as relative to the end of the MMC partition. This can be useful if
4548 your board may be fitted with different MMC devices, which have
4549 different sizes for the MMC partitions, and you always want the
4550 environment placed at the very end of the partition, to leave the
4551 maximum possible space before it, to store other data.
4553 These two values are in units of bytes, but must be aligned to an
4554 MMC sector boundary.
4556 - CONFIG_ENV_OFFSET_REDUND (optional):
4558 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4559 hold a redundant copy of the environment data. This provides a
4560 valid backup copy in case the other copy is corrupted, e.g. due
4561 to a power failure during a "saveenv" operation.
4563 This value may also be positive or negative; this is handled in the
4564 same way as CONFIG_ENV_OFFSET.
4566 This value is also in units of bytes, but must also be aligned to
4567 an MMC sector boundary.
4569 - CONFIG_ENV_SIZE_REDUND (optional):
4571 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4572 set. If this value is set, it must be set to the same value as
4575 - CONFIG_SYS_SPI_INIT_OFFSET
4577 Defines offset to the initial SPI buffer area in DPRAM. The
4578 area is used at an early stage (ROM part) if the environment
4579 is configured to reside in the SPI EEPROM: We need a 520 byte
4580 scratch DPRAM area. It is used between the two initialization
4581 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4582 to be a good choice since it makes it far enough from the
4583 start of the data area as well as from the stack pointer.
4585 Please note that the environment is read-only until the monitor
4586 has been relocated to RAM and a RAM copy of the environment has been
4587 created; also, when using EEPROM you will have to use getenv_f()
4588 until then to read environment variables.
4590 The environment is protected by a CRC32 checksum. Before the monitor
4591 is relocated into RAM, as a result of a bad CRC you will be working
4592 with the compiled-in default environment - *silently*!!! [This is
4593 necessary, because the first environment variable we need is the
4594 "baudrate" setting for the console - if we have a bad CRC, we don't
4595 have any device yet where we could complain.]
4597 Note: once the monitor has been relocated, then it will complain if
4598 the default environment is used; a new CRC is computed as soon as you
4599 use the "saveenv" command to store a valid environment.
4601 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4602 Echo the inverted Ethernet link state to the fault LED.
4604 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4605 also needs to be defined.
4607 - CONFIG_SYS_FAULT_MII_ADDR:
4608 MII address of the PHY to check for the Ethernet link state.
4610 - CONFIG_NS16550_MIN_FUNCTIONS:
4611 Define this if you desire to only have use of the NS16550_init
4612 and NS16550_putc functions for the serial driver located at
4613 drivers/serial/ns16550.c. This option is useful for saving
4614 space for already greatly restricted images, including but not
4615 limited to NAND_SPL configurations.
4617 - CONFIG_DISPLAY_BOARDINFO
4618 Display information about the board that U-Boot is running on
4619 when U-Boot starts up. The board function checkboard() is called
4622 - CONFIG_DISPLAY_BOARDINFO_LATE
4623 Similar to the previous option, but display this information
4624 later, once stdio is running and output goes to the LCD, if
4627 - CONFIG_BOARD_SIZE_LIMIT:
4628 Maximum size of the U-Boot image. When defined, the
4629 build system checks that the actual size does not
4632 Low Level (hardware related) configuration options:
4633 ---------------------------------------------------
4635 - CONFIG_SYS_CACHELINE_SIZE:
4636 Cache Line Size of the CPU.
4638 - CONFIG_SYS_DEFAULT_IMMR:
4639 Default address of the IMMR after system reset.
4641 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4642 and RPXsuper) to be able to adjust the position of
4643 the IMMR register after a reset.
4645 - CONFIG_SYS_CCSRBAR_DEFAULT:
4646 Default (power-on reset) physical address of CCSR on Freescale
4649 - CONFIG_SYS_CCSRBAR:
4650 Virtual address of CCSR. On a 32-bit build, this is typically
4651 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4653 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4654 for cross-platform code that uses that macro instead.
4656 - CONFIG_SYS_CCSRBAR_PHYS:
4657 Physical address of CCSR. CCSR can be relocated to a new
4658 physical address, if desired. In this case, this macro should
4659 be set to that address. Otherwise, it should be set to the
4660 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4661 is typically relocated on 36-bit builds. It is recommended
4662 that this macro be defined via the _HIGH and _LOW macros:
4664 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4665 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4667 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4668 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4669 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4670 used in assembly code, so it must not contain typecasts or
4671 integer size suffixes (e.g. "ULL").
4673 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4674 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4675 used in assembly code, so it must not contain typecasts or
4676 integer size suffixes (e.g. "ULL").
4678 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4679 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4680 forced to a value that ensures that CCSR is not relocated.
4682 - Floppy Disk Support:
4683 CONFIG_SYS_FDC_DRIVE_NUMBER
4685 the default drive number (default value 0)
4687 CONFIG_SYS_ISA_IO_STRIDE
4689 defines the spacing between FDC chipset registers
4692 CONFIG_SYS_ISA_IO_OFFSET
4694 defines the offset of register from address. It
4695 depends on which part of the data bus is connected to
4696 the FDC chipset. (default value 0)
4698 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4699 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4702 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4703 fdc_hw_init() is called at the beginning of the FDC
4704 setup. fdc_hw_init() must be provided by the board
4705 source code. It is used to make hardware-dependent
4709 Most IDE controllers were designed to be connected with PCI
4710 interface. Only few of them were designed for AHB interface.
4711 When software is doing ATA command and data transfer to
4712 IDE devices through IDE-AHB controller, some additional
4713 registers accessing to these kind of IDE-AHB controller
4716 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4717 DO NOT CHANGE unless you know exactly what you're
4718 doing! (11-4) [MPC8xx/82xx systems only]
4720 - CONFIG_SYS_INIT_RAM_ADDR:
4722 Start address of memory area that can be used for
4723 initial data and stack; please note that this must be
4724 writable memory that is working WITHOUT special
4725 initialization, i. e. you CANNOT use normal RAM which
4726 will become available only after programming the
4727 memory controller and running certain initialization
4730 U-Boot uses the following memory types:
4731 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4732 - MPC824X: data cache
4733 - PPC4xx: data cache
4735 - CONFIG_SYS_GBL_DATA_OFFSET:
4737 Offset of the initial data structure in the memory
4738 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4739 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4740 data is located at the end of the available space
4741 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4742 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4743 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4744 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4747 On the MPC824X (or other systems that use the data
4748 cache for initial memory) the address chosen for
4749 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4750 point to an otherwise UNUSED address space between
4751 the top of RAM and the start of the PCI space.
4753 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4755 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4757 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4759 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4761 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4763 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4765 - CONFIG_SYS_OR_TIMING_SDRAM:
4768 - CONFIG_SYS_MAMR_PTA:
4769 periodic timer for refresh
4771 - CONFIG_SYS_DER: Debug Event Register (37-47)
4773 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4774 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4775 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4776 CONFIG_SYS_BR1_PRELIM:
4777 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4779 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4780 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4781 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4782 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4784 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4785 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4786 Machine Mode Register and Memory Periodic Timer
4787 Prescaler definitions (SDRAM timing)
4789 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4790 enable I2C microcode relocation patch (MPC8xx);
4791 define relocation offset in DPRAM [DSP2]
4793 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4794 enable SMC microcode relocation patch (MPC8xx);
4795 define relocation offset in DPRAM [SMC1]
4797 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4798 enable SPI microcode relocation patch (MPC8xx);
4799 define relocation offset in DPRAM [SCC4]
4801 - CONFIG_SYS_USE_OSCCLK:
4802 Use OSCM clock mode on MBX8xx board. Be careful,
4803 wrong setting might damage your board. Read
4804 doc/README.MBX before setting this variable!
4806 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4807 Offset of the bootmode word in DPRAM used by post
4808 (Power On Self Tests). This definition overrides
4809 #define'd default value in commproc.h resp.
4812 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4813 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4814 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4815 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4816 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4817 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4818 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4819 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4820 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4822 - CONFIG_PCI_DISABLE_PCIE:
4823 Disable PCI-Express on systems where it is supported but not
4826 - CONFIG_PCI_ENUM_ONLY
4827 Only scan through and get the devices on the buses.
4828 Don't do any setup work, presumably because someone or
4829 something has already done it, and we don't need to do it
4830 a second time. Useful for platforms that are pre-booted
4831 by coreboot or similar.
4833 - CONFIG_PCI_INDIRECT_BRIDGE:
4834 Enable support for indirect PCI bridges.
4837 Chip has SRIO or not
4840 Board has SRIO 1 port available
4843 Board has SRIO 2 port available
4845 - CONFIG_SRIO_PCIE_BOOT_MASTER
4846 Board can support master function for Boot from SRIO and PCIE
4848 - CONFIG_SYS_SRIOn_MEM_VIRT:
4849 Virtual Address of SRIO port 'n' memory region
4851 - CONFIG_SYS_SRIOn_MEM_PHYS:
4852 Physical Address of SRIO port 'n' memory region
4854 - CONFIG_SYS_SRIOn_MEM_SIZE:
4855 Size of SRIO port 'n' memory region
4857 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4858 Defined to tell the NAND controller that the NAND chip is using
4860 Not all NAND drivers use this symbol.
4861 Example of drivers that use it:
4862 - drivers/mtd/nand/ndfc.c
4863 - drivers/mtd/nand/mxc_nand.c
4865 - CONFIG_SYS_NDFC_EBC0_CFG
4866 Sets the EBC0_CFG register for the NDFC. If not defined
4867 a default value will be used.
4870 Get DDR timing information from an I2C EEPROM. Common
4871 with pluggable memory modules such as SODIMMs
4874 I2C address of the SPD EEPROM
4876 - CONFIG_SYS_SPD_BUS_NUM
4877 If SPD EEPROM is on an I2C bus other than the first
4878 one, specify here. Note that the value must resolve
4879 to something your driver can deal with.
4881 - CONFIG_SYS_DDR_RAW_TIMING
4882 Get DDR timing information from other than SPD. Common with
4883 soldered DDR chips onboard without SPD. DDR raw timing
4884 parameters are extracted from datasheet and hard-coded into
4885 header files or board specific files.
4887 - CONFIG_FSL_DDR_INTERACTIVE
4888 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4890 - CONFIG_FSL_DDR_SYNC_REFRESH
4891 Enable sync of refresh for multiple controllers.
4893 - CONFIG_SYS_83XX_DDR_USES_CS0
4894 Only for 83xx systems. If specified, then DDR should
4895 be configured using CS0 and CS1 instead of CS2 and CS3.
4897 - CONFIG_ETHER_ON_FEC[12]
4898 Define to enable FEC[12] on a 8xx series processor.
4900 - CONFIG_FEC[12]_PHY
4901 Define to the hardcoded PHY address which corresponds
4902 to the given FEC; i. e.
4903 #define CONFIG_FEC1_PHY 4
4904 means that the PHY with address 4 is connected to FEC1
4906 When set to -1, means to probe for first available.
4908 - CONFIG_FEC[12]_PHY_NORXERR
4909 The PHY does not have a RXERR line (RMII only).
4910 (so program the FEC to ignore it).
4913 Enable RMII mode for all FECs.
4914 Note that this is a global option, we can't
4915 have one FEC in standard MII mode and another in RMII mode.
4917 - CONFIG_CRC32_VERIFY
4918 Add a verify option to the crc32 command.
4921 => crc32 -v <address> <count> <crc32>
4923 Where address/count indicate a memory area
4924 and crc32 is the correct crc32 which the
4928 Add the "loopw" memory command. This only takes effect if
4929 the memory commands are activated globally (CONFIG_CMD_MEM).
4932 Add the "mdc" and "mwc" memory commands. These are cyclic
4937 This command will print 4 bytes (10,11,12,13) each 500 ms.
4939 => mwc.l 100 12345678 10
4940 This command will write 12345678 to address 100 all 10 ms.
4942 This only takes effect if the memory commands are activated
4943 globally (CONFIG_CMD_MEM).
4945 - CONFIG_SKIP_LOWLEVEL_INIT
4946 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4947 low level initializations (like setting up the memory
4948 controller) are omitted and/or U-Boot does not
4949 relocate itself into RAM.
4951 Normally this variable MUST NOT be defined. The only
4952 exception is when U-Boot is loaded (to RAM) by some
4953 other boot loader or by a debugger which performs
4954 these initializations itself.
4957 Modifies the behaviour of start.S when compiling a loader
4958 that is executed before the actual U-Boot. E.g. when
4959 compiling a NAND SPL.
4962 Modifies the behaviour of start.S when compiling a loader
4963 that is executed after the SPL and before the actual U-Boot.
4964 It is loaded by the SPL.
4966 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4967 Only for 85xx systems. If this variable is specified, the section
4968 .resetvec is not kept and the section .bootpg is placed in the
4969 previous 4k of the .text section.
4971 - CONFIG_ARCH_MAP_SYSMEM
4972 Generally U-Boot (and in particular the md command) uses
4973 effective address. It is therefore not necessary to regard
4974 U-Boot address as virtual addresses that need to be translated
4975 to physical addresses. However, sandbox requires this, since
4976 it maintains its own little RAM buffer which contains all
4977 addressable memory. This option causes some memory accesses
4978 to be mapped through map_sysmem() / unmap_sysmem().
4980 - CONFIG_USE_ARCH_MEMCPY
4981 CONFIG_USE_ARCH_MEMSET
4982 If these options are used a optimized version of memcpy/memset will
4983 be used if available. These functions may be faster under some
4984 conditions but may increase the binary size.
4986 - CONFIG_X86_RESET_VECTOR
4987 If defined, the x86 reset vector code is included. This is not
4988 needed when U-Boot is running from Coreboot.
4991 Defines the MPU clock speed (in MHz).
4993 NOTE : currently only supported on AM335x platforms.
4995 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4996 Enables the RTC32K OSC on AM33xx based plattforms
4998 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4999 Option to disable subpage write in NAND driver
5000 driver that uses this:
5001 drivers/mtd/nand/davinci_nand.c
5003 Freescale QE/FMAN Firmware Support:
5004 -----------------------------------
5006 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5007 loading of "firmware", which is encoded in the QE firmware binary format.
5008 This firmware often needs to be loaded during U-Boot booting, so macros
5009 are used to identify the storage device (NOR flash, SPI, etc) and the address
5012 - CONFIG_SYS_FMAN_FW_ADDR
5013 The address in the storage device where the FMAN microcode is located. The
5014 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5017 - CONFIG_SYS_QE_FW_ADDR
5018 The address in the storage device where the QE microcode is located. The
5019 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5022 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5023 The maximum possible size of the firmware. The firmware binary format
5024 has a field that specifies the actual size of the firmware, but it
5025 might not be possible to read any part of the firmware unless some
5026 local storage is allocated to hold the entire firmware first.
5028 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5029 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5030 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5031 virtual address in NOR flash.
5033 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5034 Specifies that QE/FMAN firmware is located in NAND flash.
5035 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5037 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5038 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5039 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5041 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5042 Specifies that QE/FMAN firmware is located on the primary SPI
5043 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5045 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5046 Specifies that QE/FMAN firmware is located in the remote (master)
5047 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5048 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5049 window->master inbound window->master LAW->the ucode address in
5050 master's memory space.
5052 Freescale Layerscape Management Complex Firmware Support:
5053 ---------------------------------------------------------
5054 The Freescale Layerscape Management Complex (MC) supports the loading of
5056 This firmware often needs to be loaded during U-Boot booting, so macros
5057 are used to identify the storage device (NOR flash, SPI, etc) and the address
5060 - CONFIG_FSL_MC_ENET
5061 Enable the MC driver for Layerscape SoCs.
5063 - CONFIG_SYS_LS_MC_FW_ADDR
5064 The address in the storage device where the firmware is located. The
5065 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5068 - CONFIG_SYS_LS_MC_FW_LENGTH
5069 The maximum possible size of the firmware. The firmware binary format
5070 has a field that specifies the actual size of the firmware, but it
5071 might not be possible to read any part of the firmware unless some
5072 local storage is allocated to hold the entire firmware first.
5074 - CONFIG_SYS_LS_MC_FW_IN_NOR
5075 Specifies that MC firmware is located in NOR flash, mapped as
5076 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5077 virtual address in NOR flash.
5079 Building the Software:
5080 ======================
5082 Building U-Boot has been tested in several native build environments
5083 and in many different cross environments. Of course we cannot support
5084 all possibly existing versions of cross development tools in all
5085 (potentially obsolete) versions. In case of tool chain problems we
5086 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5087 which is extensively used to build and test U-Boot.
5089 If you are not using a native environment, it is assumed that you
5090 have GNU cross compiling tools available in your path. In this case,
5091 you must set the environment variable CROSS_COMPILE in your shell.
5092 Note that no changes to the Makefile or any other source files are
5093 necessary. For example using the ELDK on a 4xx CPU, please enter:
5095 $ CROSS_COMPILE=ppc_4xx-
5096 $ export CROSS_COMPILE
5098 Note: If you wish to generate Windows versions of the utilities in
5099 the tools directory you can use the MinGW toolchain
5100 (http://www.mingw.org). Set your HOST tools to the MinGW
5101 toolchain and execute 'make tools'. For example:
5103 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5105 Binaries such as tools/mkimage.exe will be created which can
5106 be executed on computers running Windows.
5108 U-Boot is intended to be simple to build. After installing the
5109 sources you must configure U-Boot for one specific board type. This
5114 where "NAME_defconfig" is the name of one of the existing configu-
5115 rations; see boards.cfg for supported names.
5117 Note: for some board special configuration names may exist; check if
5118 additional information is available from the board vendor; for
5119 instance, the TQM823L systems are available without (standard)
5120 or with LCD support. You can select such additional "features"
5121 when choosing the configuration, i. e.
5123 make TQM823L_defconfig
5124 - will configure for a plain TQM823L, i. e. no LCD support
5126 make TQM823L_LCD_defconfig
5127 - will configure for a TQM823L with U-Boot console on LCD
5132 Finally, type "make all", and you should get some working U-Boot
5133 images ready for download to / installation on your system:
5135 - "u-boot.bin" is a raw binary image
5136 - "u-boot" is an image in ELF binary format
5137 - "u-boot.srec" is in Motorola S-Record format
5139 By default the build is performed locally and the objects are saved
5140 in the source directory. One of the two methods can be used to change
5141 this behavior and build U-Boot to some external directory:
5143 1. Add O= to the make command line invocations:
5145 make O=/tmp/build distclean
5146 make O=/tmp/build NAME_defconfig
5147 make O=/tmp/build all
5149 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5151 export KBUILD_OUTPUT=/tmp/build
5156 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5160 Please be aware that the Makefiles assume you are using GNU make, so
5161 for instance on NetBSD you might need to use "gmake" instead of
5165 If the system board that you have is not listed, then you will need
5166 to port U-Boot to your hardware platform. To do this, follow these
5169 1. Add a new configuration option for your board to the toplevel
5170 "boards.cfg" file, using the existing entries as examples.
5171 Follow the instructions there to keep the boards in order.
5172 2. Create a new directory to hold your board specific code. Add any
5173 files you need. In your board directory, you will need at least
5174 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5175 3. Create a new configuration file "include/configs/<board>.h" for
5177 3. If you're porting U-Boot to a new CPU, then also create a new
5178 directory to hold your CPU specific code. Add any files you need.
5179 4. Run "make <board>_defconfig" with your new name.
5180 5. Type "make", and you should get a working "u-boot.srec" file
5181 to be installed on your target system.
5182 6. Debug and solve any problems that might arise.
5183 [Of course, this last step is much harder than it sounds.]
5186 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5187 ==============================================================
5189 If you have modified U-Boot sources (for instance added a new board
5190 or support for new devices, a new CPU, etc.) you are expected to
5191 provide feedback to the other developers. The feedback normally takes
5192 the form of a "patch", i. e. a context diff against a certain (latest
5193 official or latest in the git repository) version of U-Boot sources.
5195 But before you submit such a patch, please verify that your modifi-
5196 cation did not break existing code. At least make sure that *ALL* of
5197 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5198 just run the "MAKEALL" script, which will configure and build U-Boot
5199 for ALL supported system. Be warned, this will take a while. You can
5200 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5201 environment variable to the script, i. e. to use the ELDK cross tools
5204 CROSS_COMPILE=ppc_8xx- MAKEALL
5206 or to build on a native PowerPC system you can type
5208 CROSS_COMPILE=' ' MAKEALL
5210 When using the MAKEALL script, the default behaviour is to build
5211 U-Boot in the source directory. This location can be changed by
5212 setting the BUILD_DIR environment variable. Also, for each target
5213 built, the MAKEALL script saves two log files (<target>.ERR and
5214 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5215 location can be changed by setting the MAKEALL_LOGDIR environment
5216 variable. For example:
5218 export BUILD_DIR=/tmp/build
5219 export MAKEALL_LOGDIR=/tmp/log
5220 CROSS_COMPILE=ppc_8xx- MAKEALL
5222 With the above settings build objects are saved in the /tmp/build,
5223 log files are saved in the /tmp/log and the source tree remains clean
5224 during the whole build process.
5227 See also "U-Boot Porting Guide" below.
5230 Monitor Commands - Overview:
5231 ============================
5233 go - start application at address 'addr'
5234 run - run commands in an environment variable
5235 bootm - boot application image from memory
5236 bootp - boot image via network using BootP/TFTP protocol
5237 bootz - boot zImage from memory
5238 tftpboot- boot image via network using TFTP protocol
5239 and env variables "ipaddr" and "serverip"
5240 (and eventually "gatewayip")
5241 tftpput - upload a file via network using TFTP protocol
5242 rarpboot- boot image via network using RARP/TFTP protocol
5243 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5244 loads - load S-Record file over serial line
5245 loadb - load binary file over serial line (kermit mode)
5247 mm - memory modify (auto-incrementing)
5248 nm - memory modify (constant address)
5249 mw - memory write (fill)
5251 cmp - memory compare
5252 crc32 - checksum calculation
5253 i2c - I2C sub-system
5254 sspi - SPI utility commands
5255 base - print or set address offset
5256 printenv- print environment variables
5257 setenv - set environment variables
5258 saveenv - save environment variables to persistent storage
5259 protect - enable or disable FLASH write protection
5260 erase - erase FLASH memory
5261 flinfo - print FLASH memory information
5262 nand - NAND memory operations (see doc/README.nand)
5263 bdinfo - print Board Info structure
5264 iminfo - print header information for application image
5265 coninfo - print console devices and informations
5266 ide - IDE sub-system
5267 loop - infinite loop on address range
5268 loopw - infinite write loop on address range
5269 mtest - simple RAM test
5270 icache - enable or disable instruction cache
5271 dcache - enable or disable data cache
5272 reset - Perform RESET of the CPU
5273 echo - echo args to console
5274 version - print monitor version
5275 help - print online help
5276 ? - alias for 'help'
5279 Monitor Commands - Detailed Description:
5280 ========================================
5284 For now: just type "help <command>".
5287 Environment Variables:
5288 ======================
5290 U-Boot supports user configuration using Environment Variables which
5291 can be made persistent by saving to Flash memory.
5293 Environment Variables are set using "setenv", printed using
5294 "printenv", and saved to Flash using "saveenv". Using "setenv"
5295 without a value can be used to delete a variable from the
5296 environment. As long as you don't save the environment you are
5297 working with an in-memory copy. In case the Flash area containing the
5298 environment is erased by accident, a default environment is provided.
5300 Some configuration options can be set using Environment Variables.
5302 List of environment variables (most likely not complete):
5304 baudrate - see CONFIG_BAUDRATE
5306 bootdelay - see CONFIG_BOOTDELAY
5308 bootcmd - see CONFIG_BOOTCOMMAND
5310 bootargs - Boot arguments when booting an RTOS image
5312 bootfile - Name of the image to load with TFTP
5314 bootm_low - Memory range available for image processing in the bootm
5315 command can be restricted. This variable is given as
5316 a hexadecimal number and defines lowest address allowed
5317 for use by the bootm command. See also "bootm_size"
5318 environment variable. Address defined by "bootm_low" is
5319 also the base of the initial memory mapping for the Linux
5320 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5323 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5324 This variable is given as a hexadecimal number and it
5325 defines the size of the memory region starting at base
5326 address bootm_low that is accessible by the Linux kernel
5327 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5328 as the default value if it is defined, and bootm_size is
5331 bootm_size - Memory range available for image processing in the bootm
5332 command can be restricted. This variable is given as
5333 a hexadecimal number and defines the size of the region
5334 allowed for use by the bootm command. See also "bootm_low"
5335 environment variable.
5337 updatefile - Location of the software update file on a TFTP server, used
5338 by the automatic software update feature. Please refer to
5339 documentation in doc/README.update for more details.
5341 autoload - if set to "no" (any string beginning with 'n'),
5342 "bootp" will just load perform a lookup of the
5343 configuration from the BOOTP server, but not try to
5344 load any image using TFTP
5346 autostart - if set to "yes", an image loaded using the "bootp",
5347 "rarpboot", "tftpboot" or "diskboot" commands will
5348 be automatically started (by internally calling
5351 If set to "no", a standalone image passed to the
5352 "bootm" command will be copied to the load address
5353 (and eventually uncompressed), but NOT be started.
5354 This can be used to load and uncompress arbitrary
5357 fdt_high - if set this restricts the maximum address that the
5358 flattened device tree will be copied into upon boot.
5359 For example, if you have a system with 1 GB memory
5360 at physical address 0x10000000, while Linux kernel
5361 only recognizes the first 704 MB as low memory, you
5362 may need to set fdt_high as 0x3C000000 to have the
5363 device tree blob be copied to the maximum address
5364 of the 704 MB low memory, so that Linux kernel can
5365 access it during the boot procedure.
5367 If this is set to the special value 0xFFFFFFFF then
5368 the fdt will not be copied at all on boot. For this
5369 to work it must reside in writable memory, have
5370 sufficient padding on the end of it for u-boot to
5371 add the information it needs into it, and the memory
5372 must be accessible by the kernel.
5374 fdtcontroladdr- if set this is the address of the control flattened
5375 device tree used by U-Boot when CONFIG_OF_CONTROL is
5378 i2cfast - (PPC405GP|PPC405EP only)
5379 if set to 'y' configures Linux I2C driver for fast
5380 mode (400kHZ). This environment variable is used in
5381 initialization code. So, for changes to be effective
5382 it must be saved and board must be reset.
5384 initrd_high - restrict positioning of initrd images:
5385 If this variable is not set, initrd images will be
5386 copied to the highest possible address in RAM; this
5387 is usually what you want since it allows for
5388 maximum initrd size. If for some reason you want to
5389 make sure that the initrd image is loaded below the
5390 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5391 variable to a value of "no" or "off" or "0".
5392 Alternatively, you can set it to a maximum upper
5393 address to use (U-Boot will still check that it
5394 does not overwrite the U-Boot stack and data).
5396 For instance, when you have a system with 16 MB
5397 RAM, and want to reserve 4 MB from use by Linux,
5398 you can do this by adding "mem=12M" to the value of
5399 the "bootargs" variable. However, now you must make
5400 sure that the initrd image is placed in the first
5401 12 MB as well - this can be done with
5403 setenv initrd_high 00c00000
5405 If you set initrd_high to 0xFFFFFFFF, this is an
5406 indication to U-Boot that all addresses are legal
5407 for the Linux kernel, including addresses in flash
5408 memory. In this case U-Boot will NOT COPY the
5409 ramdisk at all. This may be useful to reduce the
5410 boot time on your system, but requires that this
5411 feature is supported by your Linux kernel.
5413 ipaddr - IP address; needed for tftpboot command
5415 loadaddr - Default load address for commands like "bootp",
5416 "rarpboot", "tftpboot", "loadb" or "diskboot"
5418 loads_echo - see CONFIG_LOADS_ECHO
5420 serverip - TFTP server IP address; needed for tftpboot command
5422 bootretry - see CONFIG_BOOT_RETRY_TIME
5424 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5426 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5428 ethprime - controls which interface is used first.
5430 ethact - controls which interface is currently active.
5431 For example you can do the following
5433 => setenv ethact FEC
5434 => ping 192.168.0.1 # traffic sent on FEC
5435 => setenv ethact SCC
5436 => ping 10.0.0.1 # traffic sent on SCC
5438 ethrotate - When set to "no" U-Boot does not go through all
5439 available network interfaces.
5440 It just stays at the currently selected interface.
5442 netretry - When set to "no" each network operation will
5443 either succeed or fail without retrying.
5444 When set to "once" the network operation will
5445 fail when all the available network interfaces
5446 are tried once without success.
5447 Useful on scripts which control the retry operation
5450 npe_ucode - set load address for the NPE microcode
5452 silent_linux - If set then Linux will be told to boot silently, by
5453 changing the console to be empty. If "yes" it will be
5454 made silent. If "no" it will not be made silent. If
5455 unset, then it will be made silent if the U-Boot console
5458 tftpsrcport - If this is set, the value is used for TFTP's
5461 tftpdstport - If this is set, the value is used for TFTP's UDP
5462 destination port instead of the Well Know Port 69.
5464 tftpblocksize - Block size to use for TFTP transfers; if not set,
5465 we use the TFTP server's default block size
5467 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5468 seconds, minimum value is 1000 = 1 second). Defines
5469 when a packet is considered to be lost so it has to
5470 be retransmitted. The default is 5000 = 5 seconds.
5471 Lowering this value may make downloads succeed
5472 faster in networks with high packet loss rates or
5473 with unreliable TFTP servers.
5475 vlan - When set to a value < 4095 the traffic over
5476 Ethernet is encapsulated/received over 802.1q
5479 The following image location variables contain the location of images
5480 used in booting. The "Image" column gives the role of the image and is
5481 not an environment variable name. The other columns are environment
5482 variable names. "File Name" gives the name of the file on a TFTP
5483 server, "RAM Address" gives the location in RAM the image will be
5484 loaded to, and "Flash Location" gives the image's address in NOR
5485 flash or offset in NAND flash.
5487 *Note* - these variables don't have to be defined for all boards, some
5488 boards currenlty use other variables for these purposes, and some
5489 boards use these variables for other purposes.
5491 Image File Name RAM Address Flash Location
5492 ----- --------- ----------- --------------
5493 u-boot u-boot u-boot_addr_r u-boot_addr
5494 Linux kernel bootfile kernel_addr_r kernel_addr
5495 device tree blob fdtfile fdt_addr_r fdt_addr
5496 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5498 The following environment variables may be used and automatically
5499 updated by the network boot commands ("bootp" and "rarpboot"),
5500 depending the information provided by your boot server:
5502 bootfile - see above
5503 dnsip - IP address of your Domain Name Server
5504 dnsip2 - IP address of your secondary Domain Name Server
5505 gatewayip - IP address of the Gateway (Router) to use
5506 hostname - Target hostname
5508 netmask - Subnet Mask
5509 rootpath - Pathname of the root filesystem on the NFS server
5510 serverip - see above
5513 There are two special Environment Variables:
5515 serial# - contains hardware identification information such
5516 as type string and/or serial number
5517 ethaddr - Ethernet address
5519 These variables can be set only once (usually during manufacturing of
5520 the board). U-Boot refuses to delete or overwrite these variables
5521 once they have been set once.
5524 Further special Environment Variables:
5526 ver - Contains the U-Boot version string as printed
5527 with the "version" command. This variable is
5528 readonly (see CONFIG_VERSION_VARIABLE).
5531 Please note that changes to some configuration parameters may take
5532 only effect after the next boot (yes, that's just like Windoze :-).
5535 Callback functions for environment variables:
5536 ---------------------------------------------
5538 For some environment variables, the behavior of u-boot needs to change
5539 when their values are changed. This functionality allows functions to
5540 be associated with arbitrary variables. On creation, overwrite, or
5541 deletion, the callback will provide the opportunity for some side
5542 effect to happen or for the change to be rejected.
5544 The callbacks are named and associated with a function using the
5545 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5547 These callbacks are associated with variables in one of two ways. The
5548 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5549 in the board configuration to a string that defines a list of
5550 associations. The list must be in the following format:
5552 entry = variable_name[:callback_name]
5555 If the callback name is not specified, then the callback is deleted.
5556 Spaces are also allowed anywhere in the list.
5558 Callbacks can also be associated by defining the ".callbacks" variable
5559 with the same list format above. Any association in ".callbacks" will
5560 override any association in the static list. You can define
5561 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5562 ".callbacks" environment variable in the default or embedded environment.
5565 Command Line Parsing:
5566 =====================
5568 There are two different command line parsers available with U-Boot:
5569 the old "simple" one, and the much more powerful "hush" shell:
5571 Old, simple command line parser:
5572 --------------------------------
5574 - supports environment variables (through setenv / saveenv commands)
5575 - several commands on one line, separated by ';'
5576 - variable substitution using "... ${name} ..." syntax
5577 - special characters ('$', ';') can be escaped by prefixing with '\',
5579 setenv bootcmd bootm \${address}
5580 - You can also escape text by enclosing in single apostrophes, for example:
5581 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5586 - similar to Bourne shell, with control structures like
5587 if...then...else...fi, for...do...done; while...do...done,
5588 until...do...done, ...
5589 - supports environment ("global") variables (through setenv / saveenv
5590 commands) and local shell variables (through standard shell syntax
5591 "name=value"); only environment variables can be used with "run"
5597 (1) If a command line (or an environment variable executed by a "run"
5598 command) contains several commands separated by semicolon, and
5599 one of these commands fails, then the remaining commands will be
5602 (2) If you execute several variables with one call to run (i. e.
5603 calling run with a list of variables as arguments), any failing
5604 command will cause "run" to terminate, i. e. the remaining
5605 variables are not executed.
5607 Note for Redundant Ethernet Interfaces:
5608 =======================================
5610 Some boards come with redundant Ethernet interfaces; U-Boot supports
5611 such configurations and is capable of automatic selection of a
5612 "working" interface when needed. MAC assignment works as follows:
5614 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5615 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5616 "eth1addr" (=>eth1), "eth2addr", ...
5618 If the network interface stores some valid MAC address (for instance
5619 in SROM), this is used as default address if there is NO correspon-
5620 ding setting in the environment; if the corresponding environment
5621 variable is set, this overrides the settings in the card; that means:
5623 o If the SROM has a valid MAC address, and there is no address in the
5624 environment, the SROM's address is used.
5626 o If there is no valid address in the SROM, and a definition in the
5627 environment exists, then the value from the environment variable is
5630 o If both the SROM and the environment contain a MAC address, and
5631 both addresses are the same, this MAC address is used.
5633 o If both the SROM and the environment contain a MAC address, and the
5634 addresses differ, the value from the environment is used and a
5637 o If neither SROM nor the environment contain a MAC address, an error
5640 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5641 will be programmed into hardware as part of the initialization process. This
5642 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5643 The naming convention is as follows:
5644 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5649 U-Boot is capable of booting (and performing other auxiliary operations on)
5650 images in two formats:
5652 New uImage format (FIT)
5653 -----------------------
5655 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5656 to Flattened Device Tree). It allows the use of images with multiple
5657 components (several kernels, ramdisks, etc.), with contents protected by
5658 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5664 Old image format is based on binary files which can be basically anything,
5665 preceded by a special header; see the definitions in include/image.h for
5666 details; basically, the header defines the following image properties:
5668 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5669 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5670 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5671 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5673 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5674 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5675 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5676 * Compression Type (uncompressed, gzip, bzip2)
5682 The header is marked by a special Magic Number, and both the header
5683 and the data portions of the image are secured against corruption by
5690 Although U-Boot should support any OS or standalone application
5691 easily, the main focus has always been on Linux during the design of
5694 U-Boot includes many features that so far have been part of some
5695 special "boot loader" code within the Linux kernel. Also, any
5696 "initrd" images to be used are no longer part of one big Linux image;
5697 instead, kernel and "initrd" are separate images. This implementation
5698 serves several purposes:
5700 - the same features can be used for other OS or standalone
5701 applications (for instance: using compressed images to reduce the
5702 Flash memory footprint)
5704 - it becomes much easier to port new Linux kernel versions because
5705 lots of low-level, hardware dependent stuff are done by U-Boot
5707 - the same Linux kernel image can now be used with different "initrd"
5708 images; of course this also means that different kernel images can
5709 be run with the same "initrd". This makes testing easier (you don't
5710 have to build a new "zImage.initrd" Linux image when you just
5711 change a file in your "initrd"). Also, a field-upgrade of the
5712 software is easier now.
5718 Porting Linux to U-Boot based systems:
5719 ---------------------------------------
5721 U-Boot cannot save you from doing all the necessary modifications to
5722 configure the Linux device drivers for use with your target hardware
5723 (no, we don't intend to provide a full virtual machine interface to
5726 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5728 Just make sure your machine specific header file (for instance
5729 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5730 Information structure as we define in include/asm-<arch>/u-boot.h,
5731 and make sure that your definition of IMAP_ADDR uses the same value
5732 as your U-Boot configuration in CONFIG_SYS_IMMR.
5734 Note that U-Boot now has a driver model, a unified model for drivers.
5735 If you are adding a new driver, plumb it into driver model. If there
5736 is no uclass available, you are encouraged to create one. See
5740 Configuring the Linux kernel:
5741 -----------------------------
5743 No specific requirements for U-Boot. Make sure you have some root
5744 device (initial ramdisk, NFS) for your target system.
5747 Building a Linux Image:
5748 -----------------------
5750 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5751 not used. If you use recent kernel source, a new build target
5752 "uImage" will exist which automatically builds an image usable by
5753 U-Boot. Most older kernels also have support for a "pImage" target,
5754 which was introduced for our predecessor project PPCBoot and uses a
5755 100% compatible format.
5759 make TQM850L_defconfig
5764 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5765 encapsulate a compressed Linux kernel image with header information,
5766 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5768 * build a standard "vmlinux" kernel image (in ELF binary format):
5770 * convert the kernel into a raw binary image:
5772 ${CROSS_COMPILE}-objcopy -O binary \
5773 -R .note -R .comment \
5774 -S vmlinux linux.bin
5776 * compress the binary image:
5780 * package compressed binary image for U-Boot:
5782 mkimage -A ppc -O linux -T kernel -C gzip \
5783 -a 0 -e 0 -n "Linux Kernel Image" \
5784 -d linux.bin.gz uImage
5787 The "mkimage" tool can also be used to create ramdisk images for use
5788 with U-Boot, either separated from the Linux kernel image, or
5789 combined into one file. "mkimage" encapsulates the images with a 64
5790 byte header containing information about target architecture,
5791 operating system, image type, compression method, entry points, time
5792 stamp, CRC32 checksums, etc.
5794 "mkimage" can be called in two ways: to verify existing images and
5795 print the header information, or to build new images.
5797 In the first form (with "-l" option) mkimage lists the information
5798 contained in the header of an existing U-Boot image; this includes
5799 checksum verification:
5801 tools/mkimage -l image
5802 -l ==> list image header information
5804 The second form (with "-d" option) is used to build a U-Boot image
5805 from a "data file" which is used as image payload:
5807 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5808 -n name -d data_file image
5809 -A ==> set architecture to 'arch'
5810 -O ==> set operating system to 'os'
5811 -T ==> set image type to 'type'
5812 -C ==> set compression type 'comp'
5813 -a ==> set load address to 'addr' (hex)
5814 -e ==> set entry point to 'ep' (hex)
5815 -n ==> set image name to 'name'
5816 -d ==> use image data from 'datafile'
5818 Right now, all Linux kernels for PowerPC systems use the same load
5819 address (0x00000000), but the entry point address depends on the
5822 - 2.2.x kernels have the entry point at 0x0000000C,
5823 - 2.3.x and later kernels have the entry point at 0x00000000.
5825 So a typical call to build a U-Boot image would read:
5827 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5828 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5829 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5830 > examples/uImage.TQM850L
5831 Image Name: 2.4.4 kernel for TQM850L
5832 Created: Wed Jul 19 02:34:59 2000
5833 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5834 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5835 Load Address: 0x00000000
5836 Entry Point: 0x00000000
5838 To verify the contents of the image (or check for corruption):
5840 -> tools/mkimage -l examples/uImage.TQM850L
5841 Image Name: 2.4.4 kernel for TQM850L
5842 Created: Wed Jul 19 02:34:59 2000
5843 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5844 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5845 Load Address: 0x00000000
5846 Entry Point: 0x00000000
5848 NOTE: for embedded systems where boot time is critical you can trade
5849 speed for memory and install an UNCOMPRESSED image instead: this
5850 needs more space in Flash, but boots much faster since it does not
5851 need to be uncompressed:
5853 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5854 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5855 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5856 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5857 > examples/uImage.TQM850L-uncompressed
5858 Image Name: 2.4.4 kernel for TQM850L
5859 Created: Wed Jul 19 02:34:59 2000
5860 Image Type: PowerPC Linux Kernel Image (uncompressed)
5861 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5862 Load Address: 0x00000000
5863 Entry Point: 0x00000000
5866 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5867 when your kernel is intended to use an initial ramdisk:
5869 -> tools/mkimage -n 'Simple Ramdisk Image' \
5870 > -A ppc -O linux -T ramdisk -C gzip \
5871 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5872 Image Name: Simple Ramdisk Image
5873 Created: Wed Jan 12 14:01:50 2000
5874 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5875 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5876 Load Address: 0x00000000
5877 Entry Point: 0x00000000
5879 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5880 option performs the converse operation of the mkimage's second form (the "-d"
5881 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5884 tools/dumpimage -i image -T type -p position data_file
5885 -i ==> extract from the 'image' a specific 'data_file'
5886 -T ==> set image type to 'type'
5887 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5890 Installing a Linux Image:
5891 -------------------------
5893 To downloading a U-Boot image over the serial (console) interface,
5894 you must convert the image to S-Record format:
5896 objcopy -I binary -O srec examples/image examples/image.srec
5898 The 'objcopy' does not understand the information in the U-Boot
5899 image header, so the resulting S-Record file will be relative to
5900 address 0x00000000. To load it to a given address, you need to
5901 specify the target address as 'offset' parameter with the 'loads'
5904 Example: install the image to address 0x40100000 (which on the
5905 TQM8xxL is in the first Flash bank):
5907 => erase 40100000 401FFFFF
5913 ## Ready for S-Record download ...
5914 ~>examples/image.srec
5915 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5917 15989 15990 15991 15992
5918 [file transfer complete]
5920 ## Start Addr = 0x00000000
5923 You can check the success of the download using the 'iminfo' command;
5924 this includes a checksum verification so you can be sure no data
5925 corruption happened:
5929 ## Checking Image at 40100000 ...
5930 Image Name: 2.2.13 for initrd on TQM850L
5931 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5932 Data Size: 335725 Bytes = 327 kB = 0 MB
5933 Load Address: 00000000
5934 Entry Point: 0000000c
5935 Verifying Checksum ... OK
5941 The "bootm" command is used to boot an application that is stored in
5942 memory (RAM or Flash). In case of a Linux kernel image, the contents
5943 of the "bootargs" environment variable is passed to the kernel as
5944 parameters. You can check and modify this variable using the
5945 "printenv" and "setenv" commands:
5948 => printenv bootargs
5949 bootargs=root=/dev/ram
5951 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5953 => printenv bootargs
5954 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5957 ## Booting Linux kernel at 40020000 ...
5958 Image Name: 2.2.13 for NFS on TQM850L
5959 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5960 Data Size: 381681 Bytes = 372 kB = 0 MB
5961 Load Address: 00000000
5962 Entry Point: 0000000c
5963 Verifying Checksum ... OK
5964 Uncompressing Kernel Image ... OK
5965 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
5966 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5967 time_init: decrementer frequency = 187500000/60
5968 Calibrating delay loop... 49.77 BogoMIPS
5969 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5972 If you want to boot a Linux kernel with initial RAM disk, you pass
5973 the memory addresses of both the kernel and the initrd image (PPBCOOT
5974 format!) to the "bootm" command:
5976 => imi 40100000 40200000
5978 ## Checking Image at 40100000 ...
5979 Image Name: 2.2.13 for initrd on TQM850L
5980 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5981 Data Size: 335725 Bytes = 327 kB = 0 MB
5982 Load Address: 00000000
5983 Entry Point: 0000000c
5984 Verifying Checksum ... OK
5986 ## Checking Image at 40200000 ...
5987 Image Name: Simple Ramdisk Image
5988 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5989 Data Size: 566530 Bytes = 553 kB = 0 MB
5990 Load Address: 00000000
5991 Entry Point: 00000000
5992 Verifying Checksum ... OK
5994 => bootm 40100000 40200000
5995 ## Booting Linux kernel at 40100000 ...
5996 Image Name: 2.2.13 for initrd on TQM850L
5997 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5998 Data Size: 335725 Bytes = 327 kB = 0 MB
5999 Load Address: 00000000
6000 Entry Point: 0000000c
6001 Verifying Checksum ... OK
6002 Uncompressing Kernel Image ... OK
6003 ## Loading RAMDisk Image at 40200000 ...
6004 Image Name: Simple Ramdisk Image
6005 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6006 Data Size: 566530 Bytes = 553 kB = 0 MB
6007 Load Address: 00000000
6008 Entry Point: 00000000
6009 Verifying Checksum ... OK
6010 Loading Ramdisk ... OK
6011 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
6012 Boot arguments: root=/dev/ram
6013 time_init: decrementer frequency = 187500000/60
6014 Calibrating delay loop... 49.77 BogoMIPS
6016 RAMDISK: Compressed image found at block 0
6017 VFS: Mounted root (ext2 filesystem).
6021 Boot Linux and pass a flat device tree:
6024 First, U-Boot must be compiled with the appropriate defines. See the section
6025 titled "Linux Kernel Interface" above for a more in depth explanation. The
6026 following is an example of how to start a kernel and pass an updated
6032 oft=oftrees/mpc8540ads.dtb
6033 => tftp $oftaddr $oft
6034 Speed: 1000, full duplex
6036 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6037 Filename 'oftrees/mpc8540ads.dtb'.
6038 Load address: 0x300000
6041 Bytes transferred = 4106 (100a hex)
6042 => tftp $loadaddr $bootfile
6043 Speed: 1000, full duplex
6045 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6047 Load address: 0x200000
6048 Loading:############
6050 Bytes transferred = 1029407 (fb51f hex)
6055 => bootm $loadaddr - $oftaddr
6056 ## Booting image at 00200000 ...
6057 Image Name: Linux-2.6.17-dirty
6058 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6059 Data Size: 1029343 Bytes = 1005.2 kB
6060 Load Address: 00000000
6061 Entry Point: 00000000
6062 Verifying Checksum ... OK
6063 Uncompressing Kernel Image ... OK
6064 Booting using flat device tree at 0x300000
6065 Using MPC85xx ADS machine description
6066 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6070 More About U-Boot Image Types:
6071 ------------------------------
6073 U-Boot supports the following image types:
6075 "Standalone Programs" are directly runnable in the environment
6076 provided by U-Boot; it is expected that (if they behave
6077 well) you can continue to work in U-Boot after return from
6078 the Standalone Program.
6079 "OS Kernel Images" are usually images of some Embedded OS which
6080 will take over control completely. Usually these programs
6081 will install their own set of exception handlers, device
6082 drivers, set up the MMU, etc. - this means, that you cannot
6083 expect to re-enter U-Boot except by resetting the CPU.
6084 "RAMDisk Images" are more or less just data blocks, and their
6085 parameters (address, size) are passed to an OS kernel that is
6087 "Multi-File Images" contain several images, typically an OS
6088 (Linux) kernel image and one or more data images like
6089 RAMDisks. This construct is useful for instance when you want
6090 to boot over the network using BOOTP etc., where the boot
6091 server provides just a single image file, but you want to get
6092 for instance an OS kernel and a RAMDisk image.
6094 "Multi-File Images" start with a list of image sizes, each
6095 image size (in bytes) specified by an "uint32_t" in network
6096 byte order. This list is terminated by an "(uint32_t)0".
6097 Immediately after the terminating 0 follow the images, one by
6098 one, all aligned on "uint32_t" boundaries (size rounded up to
6099 a multiple of 4 bytes).
6101 "Firmware Images" are binary images containing firmware (like
6102 U-Boot or FPGA images) which usually will be programmed to
6105 "Script files" are command sequences that will be executed by
6106 U-Boot's command interpreter; this feature is especially
6107 useful when you configure U-Boot to use a real shell (hush)
6108 as command interpreter.
6110 Booting the Linux zImage:
6111 -------------------------
6113 On some platforms, it's possible to boot Linux zImage. This is done
6114 using the "bootz" command. The syntax of "bootz" command is the same
6115 as the syntax of "bootm" command.
6117 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6118 kernel with raw initrd images. The syntax is slightly different, the
6119 address of the initrd must be augmented by it's size, in the following
6120 format: "<initrd addres>:<initrd size>".
6126 One of the features of U-Boot is that you can dynamically load and
6127 run "standalone" applications, which can use some resources of
6128 U-Boot like console I/O functions or interrupt services.
6130 Two simple examples are included with the sources:
6135 'examples/hello_world.c' contains a small "Hello World" Demo
6136 application; it is automatically compiled when you build U-Boot.
6137 It's configured to run at address 0x00040004, so you can play with it
6141 ## Ready for S-Record download ...
6142 ~>examples/hello_world.srec
6143 1 2 3 4 5 6 7 8 9 10 11 ...
6144 [file transfer complete]
6146 ## Start Addr = 0x00040004
6148 => go 40004 Hello World! This is a test.
6149 ## Starting application at 0x00040004 ...
6160 Hit any key to exit ...
6162 ## Application terminated, rc = 0x0
6164 Another example, which demonstrates how to register a CPM interrupt
6165 handler with the U-Boot code, can be found in 'examples/timer.c'.
6166 Here, a CPM timer is set up to generate an interrupt every second.
6167 The interrupt service routine is trivial, just printing a '.'
6168 character, but this is just a demo program. The application can be
6169 controlled by the following keys:
6171 ? - print current values og the CPM Timer registers
6172 b - enable interrupts and start timer
6173 e - stop timer and disable interrupts
6174 q - quit application
6177 ## Ready for S-Record download ...
6178 ~>examples/timer.srec
6179 1 2 3 4 5 6 7 8 9 10 11 ...
6180 [file transfer complete]
6182 ## Start Addr = 0x00040004
6185 ## Starting application at 0x00040004 ...
6188 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6191 [q, b, e, ?] Set interval 1000000 us
6194 [q, b, e, ?] ........
6195 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6198 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6201 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6204 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6206 [q, b, e, ?] ...Stopping timer
6208 [q, b, e, ?] ## Application terminated, rc = 0x0
6214 Over time, many people have reported problems when trying to use the
6215 "minicom" terminal emulation program for serial download. I (wd)
6216 consider minicom to be broken, and recommend not to use it. Under
6217 Unix, I recommend to use C-Kermit for general purpose use (and
6218 especially for kermit binary protocol download ("loadb" command), and
6219 use "cu" for S-Record download ("loads" command). See
6220 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6221 for help with kermit.
6224 Nevertheless, if you absolutely want to use it try adding this
6225 configuration to your "File transfer protocols" section:
6227 Name Program Name U/D FullScr IO-Red. Multi
6228 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6229 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6235 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6236 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6238 Building requires a cross environment; it is known to work on
6239 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6240 need gmake since the Makefiles are not compatible with BSD make).
6241 Note that the cross-powerpc package does not install include files;
6242 attempting to build U-Boot will fail because <machine/ansi.h> is
6243 missing. This file has to be installed and patched manually:
6245 # cd /usr/pkg/cross/powerpc-netbsd/include
6247 # ln -s powerpc machine
6248 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6249 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6251 Native builds *don't* work due to incompatibilities between native
6252 and U-Boot include files.
6254 Booting assumes that (the first part of) the image booted is a
6255 stage-2 loader which in turn loads and then invokes the kernel
6256 proper. Loader sources will eventually appear in the NetBSD source
6257 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6258 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6261 Implementation Internals:
6262 =========================
6264 The following is not intended to be a complete description of every
6265 implementation detail. However, it should help to understand the
6266 inner workings of U-Boot and make it easier to port it to custom
6270 Initial Stack, Global Data:
6271 ---------------------------
6273 The implementation of U-Boot is complicated by the fact that U-Boot
6274 starts running out of ROM (flash memory), usually without access to
6275 system RAM (because the memory controller is not initialized yet).
6276 This means that we don't have writable Data or BSS segments, and BSS
6277 is not initialized as zero. To be able to get a C environment working
6278 at all, we have to allocate at least a minimal stack. Implementation
6279 options for this are defined and restricted by the CPU used: Some CPU
6280 models provide on-chip memory (like the IMMR area on MPC8xx and
6281 MPC826x processors), on others (parts of) the data cache can be
6282 locked as (mis-) used as memory, etc.
6284 Chris Hallinan posted a good summary of these issues to the
6285 U-Boot mailing list:
6287 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6288 From: "Chris Hallinan" <clh@net1plus.com>
6289 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6292 Correct me if I'm wrong, folks, but the way I understand it
6293 is this: Using DCACHE as initial RAM for Stack, etc, does not
6294 require any physical RAM backing up the cache. The cleverness
6295 is that the cache is being used as a temporary supply of
6296 necessary storage before the SDRAM controller is setup. It's
6297 beyond the scope of this list to explain the details, but you
6298 can see how this works by studying the cache architecture and
6299 operation in the architecture and processor-specific manuals.
6301 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6302 is another option for the system designer to use as an
6303 initial stack/RAM area prior to SDRAM being available. Either
6304 option should work for you. Using CS 4 should be fine if your
6305 board designers haven't used it for something that would
6306 cause you grief during the initial boot! It is frequently not
6309 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6310 with your processor/board/system design. The default value
6311 you will find in any recent u-boot distribution in
6312 walnut.h should work for you. I'd set it to a value larger
6313 than your SDRAM module. If you have a 64MB SDRAM module, set
6314 it above 400_0000. Just make sure your board has no resources
6315 that are supposed to respond to that address! That code in
6316 start.S has been around a while and should work as is when
6317 you get the config right.
6322 It is essential to remember this, since it has some impact on the C
6323 code for the initialization procedures:
6325 * Initialized global data (data segment) is read-only. Do not attempt
6328 * Do not use any uninitialized global data (or implicitly initialized
6329 as zero data - BSS segment) at all - this is undefined, initiali-
6330 zation is performed later (when relocating to RAM).
6332 * Stack space is very limited. Avoid big data buffers or things like
6335 Having only the stack as writable memory limits means we cannot use
6336 normal global data to share information between the code. But it
6337 turned out that the implementation of U-Boot can be greatly
6338 simplified by making a global data structure (gd_t) available to all
6339 functions. We could pass a pointer to this data as argument to _all_
6340 functions, but this would bloat the code. Instead we use a feature of
6341 the GCC compiler (Global Register Variables) to share the data: we
6342 place a pointer (gd) to the global data into a register which we
6343 reserve for this purpose.
6345 When choosing a register for such a purpose we are restricted by the
6346 relevant (E)ABI specifications for the current architecture, and by
6347 GCC's implementation.
6349 For PowerPC, the following registers have specific use:
6351 R2: reserved for system use
6352 R3-R4: parameter passing and return values
6353 R5-R10: parameter passing
6354 R13: small data area pointer
6358 (U-Boot also uses R12 as internal GOT pointer. r12
6359 is a volatile register so r12 needs to be reset when
6360 going back and forth between asm and C)
6362 ==> U-Boot will use R2 to hold a pointer to the global data
6364 Note: on PPC, we could use a static initializer (since the
6365 address of the global data structure is known at compile time),
6366 but it turned out that reserving a register results in somewhat
6367 smaller code - although the code savings are not that big (on
6368 average for all boards 752 bytes for the whole U-Boot image,
6369 624 text + 127 data).
6371 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6372 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6374 ==> U-Boot will use P3 to hold a pointer to the global data
6376 On ARM, the following registers are used:
6378 R0: function argument word/integer result
6379 R1-R3: function argument word
6380 R9: platform specific
6381 R10: stack limit (used only if stack checking is enabled)
6382 R11: argument (frame) pointer
6383 R12: temporary workspace
6386 R15: program counter
6388 ==> U-Boot will use R9 to hold a pointer to the global data
6390 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6392 On Nios II, the ABI is documented here:
6393 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6395 ==> U-Boot will use gp to hold a pointer to the global data
6397 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6398 to access small data sections, so gp is free.
6400 On NDS32, the following registers are used:
6402 R0-R1: argument/return
6404 R15: temporary register for assembler
6405 R16: trampoline register
6406 R28: frame pointer (FP)
6407 R29: global pointer (GP)
6408 R30: link register (LP)
6409 R31: stack pointer (SP)
6410 PC: program counter (PC)
6412 ==> U-Boot will use R10 to hold a pointer to the global data
6414 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6415 or current versions of GCC may "optimize" the code too much.
6420 U-Boot runs in system state and uses physical addresses, i.e. the
6421 MMU is not used either for address mapping nor for memory protection.
6423 The available memory is mapped to fixed addresses using the memory
6424 controller. In this process, a contiguous block is formed for each
6425 memory type (Flash, SDRAM, SRAM), even when it consists of several
6426 physical memory banks.
6428 U-Boot is installed in the first 128 kB of the first Flash bank (on
6429 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6430 booting and sizing and initializing DRAM, the code relocates itself
6431 to the upper end of DRAM. Immediately below the U-Boot code some
6432 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6433 configuration setting]. Below that, a structure with global Board
6434 Info data is placed, followed by the stack (growing downward).
6436 Additionally, some exception handler code is copied to the low 8 kB
6437 of DRAM (0x00000000 ... 0x00001FFF).
6439 So a typical memory configuration with 16 MB of DRAM could look like
6442 0x0000 0000 Exception Vector code
6445 0x0000 2000 Free for Application Use
6451 0x00FB FF20 Monitor Stack (Growing downward)
6452 0x00FB FFAC Board Info Data and permanent copy of global data
6453 0x00FC 0000 Malloc Arena
6456 0x00FE 0000 RAM Copy of Monitor Code
6457 ... eventually: LCD or video framebuffer
6458 ... eventually: pRAM (Protected RAM - unchanged by reset)
6459 0x00FF FFFF [End of RAM]
6462 System Initialization:
6463 ----------------------
6465 In the reset configuration, U-Boot starts at the reset entry point
6466 (on most PowerPC systems at address 0x00000100). Because of the reset
6467 configuration for CS0# this is a mirror of the on board Flash memory.
6468 To be able to re-map memory U-Boot then jumps to its link address.
6469 To be able to implement the initialization code in C, a (small!)
6470 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6471 which provide such a feature like MPC8xx or MPC8260), or in a locked
6472 part of the data cache. After that, U-Boot initializes the CPU core,
6473 the caches and the SIU.
6475 Next, all (potentially) available memory banks are mapped using a
6476 preliminary mapping. For example, we put them on 512 MB boundaries
6477 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6478 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6479 programmed for SDRAM access. Using the temporary configuration, a
6480 simple memory test is run that determines the size of the SDRAM
6483 When there is more than one SDRAM bank, and the banks are of
6484 different size, the largest is mapped first. For equal size, the first
6485 bank (CS2#) is mapped first. The first mapping is always for address
6486 0x00000000, with any additional banks following immediately to create
6487 contiguous memory starting from 0.
6489 Then, the monitor installs itself at the upper end of the SDRAM area
6490 and allocates memory for use by malloc() and for the global Board
6491 Info data; also, the exception vector code is copied to the low RAM
6492 pages, and the final stack is set up.
6494 Only after this relocation will you have a "normal" C environment;
6495 until that you are restricted in several ways, mostly because you are
6496 running from ROM, and because the code will have to be relocated to a
6500 U-Boot Porting Guide:
6501 ----------------------
6503 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6507 int main(int argc, char *argv[])
6509 sighandler_t no_more_time;
6511 signal(SIGALRM, no_more_time);
6512 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6514 if (available_money > available_manpower) {
6515 Pay consultant to port U-Boot;
6519 Download latest U-Boot source;
6521 Subscribe to u-boot mailing list;
6524 email("Hi, I am new to U-Boot, how do I get started?");
6527 Read the README file in the top level directory;
6528 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6529 Read applicable doc/*.README;
6530 Read the source, Luke;
6531 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6534 if (available_money > toLocalCurrency ($2500))
6537 Add a lot of aggravation and time;
6539 if (a similar board exists) { /* hopefully... */
6540 cp -a board/<similar> board/<myboard>
6541 cp include/configs/<similar>.h include/configs/<myboard>.h
6543 Create your own board support subdirectory;
6544 Create your own board include/configs/<myboard>.h file;
6546 Edit new board/<myboard> files
6547 Edit new include/configs/<myboard>.h
6552 Add / modify source code;
6556 email("Hi, I am having problems...");
6558 Send patch file to the U-Boot email list;
6559 if (reasonable critiques)
6560 Incorporate improvements from email list code review;
6562 Defend code as written;
6568 void no_more_time (int sig)
6577 All contributions to U-Boot should conform to the Linux kernel
6578 coding style; see the file "Documentation/CodingStyle" and the script
6579 "scripts/Lindent" in your Linux kernel source directory.
6581 Source files originating from a different project (for example the
6582 MTD subsystem) are generally exempt from these guidelines and are not
6583 reformatted to ease subsequent migration to newer versions of those
6586 Please note that U-Boot is implemented in C (and to some small parts in
6587 Assembler); no C++ is used, so please do not use C++ style comments (//)
6590 Please also stick to the following formatting rules:
6591 - remove any trailing white space
6592 - use TAB characters for indentation and vertical alignment, not spaces
6593 - make sure NOT to use DOS '\r\n' line feeds
6594 - do not add more than 2 consecutive empty lines to source files
6595 - do not add trailing empty lines to source files
6597 Submissions which do not conform to the standards may be returned
6598 with a request to reformat the changes.
6604 Since the number of patches for U-Boot is growing, we need to
6605 establish some rules. Submissions which do not conform to these rules
6606 may be rejected, even when they contain important and valuable stuff.
6608 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6610 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6611 see http://lists.denx.de/mailman/listinfo/u-boot
6613 When you send a patch, please include the following information with
6616 * For bug fixes: a description of the bug and how your patch fixes
6617 this bug. Please try to include a way of demonstrating that the
6618 patch actually fixes something.
6620 * For new features: a description of the feature and your
6623 * A CHANGELOG entry as plaintext (separate from the patch)
6625 * For major contributions, your entry to the CREDITS file
6627 * When you add support for a new board, don't forget to add a
6628 maintainer e-mail address to the boards.cfg file, too.
6630 * If your patch adds new configuration options, don't forget to
6631 document these in the README file.
6633 * The patch itself. If you are using git (which is *strongly*
6634 recommended) you can easily generate the patch using the
6635 "git format-patch". If you then use "git send-email" to send it to
6636 the U-Boot mailing list, you will avoid most of the common problems
6637 with some other mail clients.
6639 If you cannot use git, use "diff -purN OLD NEW". If your version of
6640 diff does not support these options, then get the latest version of
6643 The current directory when running this command shall be the parent
6644 directory of the U-Boot source tree (i. e. please make sure that
6645 your patch includes sufficient directory information for the
6648 We prefer patches as plain text. MIME attachments are discouraged,
6649 and compressed attachments must not be used.
6651 * If one logical set of modifications affects or creates several
6652 files, all these changes shall be submitted in a SINGLE patch file.
6654 * Changesets that contain different, unrelated modifications shall be
6655 submitted as SEPARATE patches, one patch per changeset.
6660 * Before sending the patch, run the MAKEALL script on your patched
6661 source tree and make sure that no errors or warnings are reported
6662 for any of the boards.
6664 * Keep your modifications to the necessary minimum: A patch
6665 containing several unrelated changes or arbitrary reformats will be
6666 returned with a request to re-formatting / split it.
6668 * If you modify existing code, make sure that your new code does not
6669 add to the memory footprint of the code ;-) Small is beautiful!
6670 When adding new features, these should compile conditionally only
6671 (using #ifdef), and the resulting code with the new feature
6672 disabled must not need more memory than the old code without your
6675 * Remember that there is a size limit of 100 kB per message on the
6676 u-boot mailing list. Bigger patches will be moderated. If they are
6677 reasonable and not too big, they will be acknowledged. But patches
6678 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob