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_761320
685 CONFIG_ARM_ERRATA_773022
686 CONFIG_ARM_ERRATA_774769
687 CONFIG_ARM_ERRATA_794072
689 If set, the workarounds for these ARM errata are applied early
690 during U-Boot startup. Note that these options force the
691 workarounds to be applied; no CPU-type/version detection
692 exists, unlike the similar options in the Linux kernel. Do not
693 set these options unless they apply!
696 Generic timer clock source frequency.
698 COUNTER_FREQUENCY_REAL
699 Generic timer clock source frequency if the real clock is
700 different from COUNTER_FREQUENCY, and can only be determined
703 NOTE: The following can be machine specific errata. These
704 do have ability to provide rudimentary version and machine
705 specific checks, but expect no product checks.
706 CONFIG_ARM_ERRATA_430973
707 CONFIG_ARM_ERRATA_454179
708 CONFIG_ARM_ERRATA_621766
709 CONFIG_ARM_ERRATA_798870
710 CONFIG_ARM_ERRATA_801819
713 CONFIG_TEGRA_SUPPORT_NON_SECURE
715 Support executing U-Boot in non-secure (NS) mode. Certain
716 impossible actions will be skipped if the CPU is in NS mode,
717 such as ARM architectural timer initialization.
719 - Linux Kernel Interface:
722 U-Boot stores all clock information in Hz
723 internally. For binary compatibility with older Linux
724 kernels (which expect the clocks passed in the
725 bd_info data to be in MHz) the environment variable
726 "clocks_in_mhz" can be defined so that U-Boot
727 converts clock data to MHZ before passing it to the
729 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
730 "clocks_in_mhz=1" is automatically included in the
733 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
735 When transferring memsize parameter to Linux, some versions
736 expect it to be in bytes, others in MB.
737 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
741 New kernel versions are expecting firmware settings to be
742 passed using flattened device trees (based on open firmware
746 * New libfdt-based support
747 * Adds the "fdt" command
748 * The bootm command automatically updates the fdt
750 OF_CPU - The proper name of the cpus node (only required for
751 MPC512X and MPC5xxx based boards).
752 OF_SOC - The proper name of the soc node (only required for
753 MPC512X and MPC5xxx based boards).
754 OF_TBCLK - The timebase frequency.
755 OF_STDOUT_PATH - The path to the console device
757 boards with QUICC Engines require OF_QE to set UCC MAC
760 CONFIG_OF_BOARD_SETUP
762 Board code has addition modification that it wants to make
763 to the flat device tree before handing it off to the kernel
765 CONFIG_OF_SYSTEM_SETUP
767 Other code has addition modification that it wants to make
768 to the flat device tree before handing it off to the kernel.
769 This causes ft_system_setup() to be called before booting
774 This define fills in the correct boot CPU in the boot
775 param header, the default value is zero if undefined.
779 U-Boot can detect if an IDE device is present or not.
780 If not, and this new config option is activated, U-Boot
781 removes the ATA node from the DTS before booting Linux,
782 so the Linux IDE driver does not probe the device and
783 crash. This is needed for buggy hardware (uc101) where
784 no pull down resistor is connected to the signal IDE5V_DD7.
786 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
788 This setting is mandatory for all boards that have only one
789 machine type and must be used to specify the machine type
790 number as it appears in the ARM machine registry
791 (see http://www.arm.linux.org.uk/developer/machines/).
792 Only boards that have multiple machine types supported
793 in a single configuration file and the machine type is
794 runtime discoverable, do not have to use this setting.
796 - vxWorks boot parameters:
798 bootvx constructs a valid bootline using the following
799 environments variables: bootfile, ipaddr, serverip, hostname.
800 It loads the vxWorks image pointed bootfile.
802 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
803 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
804 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
805 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
807 CONFIG_SYS_VXWORKS_ADD_PARAMS
809 Add it at the end of the bootline. E.g "u=username pw=secret"
811 Note: If a "bootargs" environment is defined, it will overwride
812 the defaults discussed just above.
814 - Cache Configuration:
815 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
816 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
817 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
819 - Cache Configuration for ARM:
820 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
822 CONFIG_SYS_PL310_BASE - Physical base address of PL310
823 controller register space
828 Define this if you want support for Amba PrimeCell PL010 UARTs.
832 Define this if you want support for Amba PrimeCell PL011 UARTs.
836 If you have Amba PrimeCell PL011 UARTs, set this variable to
837 the clock speed of the UARTs.
841 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
842 define this to a list of base addresses for each (supported)
843 port. See e.g. include/configs/versatile.h
845 CONFIG_SERIAL_HW_FLOW_CONTROL
847 Define this variable to enable hw flow control in serial driver.
848 Current user of this option is drivers/serial/nsl16550.c driver
851 Depending on board, define exactly one serial port
852 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
853 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
854 console by defining CONFIG_8xx_CONS_NONE
856 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
857 port routines must be defined elsewhere
858 (i.e. serial_init(), serial_getc(), ...)
861 Enables console device for a color framebuffer. Needs following
862 defines (cf. smiLynxEM, i8042)
863 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
865 VIDEO_HW_RECTFILL graphic chip supports
868 VIDEO_HW_BITBLT graphic chip supports
869 bit-blit (cf. smiLynxEM)
870 VIDEO_VISIBLE_COLS visible pixel columns
872 VIDEO_VISIBLE_ROWS visible pixel rows
873 VIDEO_PIXEL_SIZE bytes per pixel
874 VIDEO_DATA_FORMAT graphic data format
875 (0-5, cf. cfb_console.c)
876 VIDEO_FB_ADRS framebuffer address
877 VIDEO_KBD_INIT_FCT keyboard int fct
878 (i.e. i8042_kbd_init())
879 VIDEO_TSTC_FCT test char fct
881 VIDEO_GETC_FCT get char fct
883 CONFIG_CONSOLE_CURSOR cursor drawing on/off
884 (requires blink timer
886 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
887 CONFIG_CONSOLE_TIME display time/date info in
889 (requires CONFIG_CMD_DATE)
890 CONFIG_VIDEO_LOGO display Linux logo in
892 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
893 linux_logo.h for logo.
894 Requires CONFIG_VIDEO_LOGO
895 CONFIG_CONSOLE_EXTRA_INFO
896 additional board info beside
899 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
900 a limited number of ANSI escape sequences (cursor control,
901 erase functions and limited graphics rendition control).
903 When CONFIG_CFB_CONSOLE is defined, video console is
904 default i/o. Serial console can be forced with
905 environment 'console=serial'.
907 When CONFIG_SILENT_CONSOLE is defined, all console
908 messages (by U-Boot and Linux!) can be silenced with
909 the "silent" environment variable. See
910 doc/README.silent for more information.
912 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
914 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
918 CONFIG_BAUDRATE - in bps
919 Select one of the baudrates listed in
920 CONFIG_SYS_BAUDRATE_TABLE, see below.
921 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
923 - Console Rx buffer length
924 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
925 the maximum receive buffer length for the SMC.
926 This option is actual only for 82xx and 8xx possible.
927 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
928 must be defined, to setup the maximum idle timeout for
931 - Pre-Console Buffer:
932 Prior to the console being initialised (i.e. serial UART
933 initialised etc) all console output is silently discarded.
934 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
935 buffer any console messages prior to the console being
936 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
937 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
938 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
939 bytes are output before the console is initialised, the
940 earlier bytes are discarded.
942 Note that when printing the buffer a copy is made on the
943 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
945 'Sane' compilers will generate smaller code if
946 CONFIG_PRE_CON_BUF_SZ is a power of 2
948 - Safe printf() functions
949 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
950 the printf() functions. These are defined in
951 include/vsprintf.h and include snprintf(), vsnprintf() and
952 so on. Code size increase is approximately 300-500 bytes.
953 If this option is not given then these functions will
954 silently discard their buffer size argument - this means
955 you are not getting any overflow checking in this case.
957 - Boot Delay: CONFIG_BOOTDELAY - in seconds
958 Delay before automatically booting the default image;
959 set to -1 to disable autoboot.
960 set to -2 to autoboot with no delay and not check for abort
961 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
963 See doc/README.autoboot for these options that
964 work with CONFIG_BOOTDELAY. None are required.
965 CONFIG_BOOT_RETRY_TIME
966 CONFIG_BOOT_RETRY_MIN
967 CONFIG_AUTOBOOT_KEYED
968 CONFIG_AUTOBOOT_PROMPT
969 CONFIG_AUTOBOOT_DELAY_STR
970 CONFIG_AUTOBOOT_STOP_STR
971 CONFIG_ZERO_BOOTDELAY_CHECK
972 CONFIG_RESET_TO_RETRY
976 Only needed when CONFIG_BOOTDELAY is enabled;
977 define a command string that is automatically executed
978 when no character is read on the console interface
979 within "Boot Delay" after reset.
982 This can be used to pass arguments to the bootm
983 command. The value of CONFIG_BOOTARGS goes into the
984 environment value "bootargs".
986 CONFIG_RAMBOOT and CONFIG_NFSBOOT
987 The value of these goes into the environment as
988 "ramboot" and "nfsboot" respectively, and can be used
989 as a convenience, when switching between booting from
993 CONFIG_BOOTCOUNT_LIMIT
994 Implements a mechanism for detecting a repeating reboot
996 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
999 If no softreset save registers are found on the hardware
1000 "bootcount" is stored in the environment. To prevent a
1001 saveenv on all reboots, the environment variable
1002 "upgrade_available" is used. If "upgrade_available" is
1003 0, "bootcount" is always 0, if "upgrade_available" is
1004 1 "bootcount" is incremented in the environment.
1005 So the Userspace Applikation must set the "upgrade_available"
1006 and "bootcount" variable to 0, if a boot was successfully.
1008 - Pre-Boot Commands:
1011 When this option is #defined, the existence of the
1012 environment variable "preboot" will be checked
1013 immediately before starting the CONFIG_BOOTDELAY
1014 countdown and/or running the auto-boot command resp.
1015 entering interactive mode.
1017 This feature is especially useful when "preboot" is
1018 automatically generated or modified. For an example
1019 see the LWMON board specific code: here "preboot" is
1020 modified when the user holds down a certain
1021 combination of keys on the (special) keyboard when
1024 - Serial Download Echo Mode:
1026 If defined to 1, all characters received during a
1027 serial download (using the "loads" command) are
1028 echoed back. This might be needed by some terminal
1029 emulations (like "cu"), but may as well just take
1030 time on others. This setting #define's the initial
1031 value of the "loads_echo" environment variable.
1033 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1034 CONFIG_KGDB_BAUDRATE
1035 Select one of the baudrates listed in
1036 CONFIG_SYS_BAUDRATE_TABLE, see below.
1038 - Monitor Functions:
1039 Monitor commands can be included or excluded
1040 from the build by using the #include files
1041 <config_cmd_all.h> and #undef'ing unwanted
1042 commands, or adding #define's for wanted commands.
1044 The default command configuration includes all commands
1045 except those marked below with a "*".
1047 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1048 CONFIG_CMD_ASKENV * ask for env variable
1049 CONFIG_CMD_BDI bdinfo
1050 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1051 CONFIG_CMD_BMP * BMP support
1052 CONFIG_CMD_BSP * Board specific commands
1053 CONFIG_CMD_BOOTD bootd
1054 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1055 CONFIG_CMD_CACHE * icache, dcache
1056 CONFIG_CMD_CLK * clock command support
1057 CONFIG_CMD_CONSOLE coninfo
1058 CONFIG_CMD_CRC32 * crc32
1059 CONFIG_CMD_DATE * support for RTC, date/time...
1060 CONFIG_CMD_DHCP * DHCP support
1061 CONFIG_CMD_DIAG * Diagnostics
1062 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1063 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1064 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1065 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1066 CONFIG_CMD_DTT * Digital Therm and Thermostat
1067 CONFIG_CMD_ECHO echo arguments
1068 CONFIG_CMD_EDITENV edit env variable
1069 CONFIG_CMD_EEPROM * EEPROM read/write support
1070 CONFIG_CMD_ELF * bootelf, bootvx
1071 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1072 CONFIG_CMD_ENV_FLAGS * display details about env flags
1073 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1074 CONFIG_CMD_EXPORTENV * export the environment
1075 CONFIG_CMD_EXT2 * ext2 command support
1076 CONFIG_CMD_EXT4 * ext4 command support
1077 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1078 that work for multiple fs types
1079 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1080 CONFIG_CMD_SAVEENV saveenv
1081 CONFIG_CMD_FDC * Floppy Disk Support
1082 CONFIG_CMD_FAT * FAT command support
1083 CONFIG_CMD_FLASH flinfo, erase, protect
1084 CONFIG_CMD_FPGA FPGA device initialization support
1085 CONFIG_CMD_FUSE * Device fuse support
1086 CONFIG_CMD_GETTIME * Get time since boot
1087 CONFIG_CMD_GO * the 'go' command (exec code)
1088 CONFIG_CMD_GREPENV * search environment
1089 CONFIG_CMD_HASH * calculate hash / digest
1090 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1091 CONFIG_CMD_I2C * I2C serial bus support
1092 CONFIG_CMD_IDE * IDE harddisk support
1093 CONFIG_CMD_IMI iminfo
1094 CONFIG_CMD_IMLS List all images found in NOR flash
1095 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1096 CONFIG_CMD_IMMAP * IMMR dump support
1097 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1098 CONFIG_CMD_IMPORTENV * import an environment
1099 CONFIG_CMD_INI * import data from an ini file into the env
1100 CONFIG_CMD_IRQ * irqinfo
1101 CONFIG_CMD_ITEST Integer/string test of 2 values
1102 CONFIG_CMD_JFFS2 * JFFS2 Support
1103 CONFIG_CMD_KGDB * kgdb
1104 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1105 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1107 CONFIG_CMD_LOADB loadb
1108 CONFIG_CMD_LOADS loads
1109 CONFIG_CMD_MD5SUM * print md5 message digest
1110 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1111 CONFIG_CMD_MEMINFO * Display detailed memory information
1112 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1114 CONFIG_CMD_MEMTEST * mtest
1115 CONFIG_CMD_MISC Misc functions like sleep etc
1116 CONFIG_CMD_MMC * MMC memory mapped support
1117 CONFIG_CMD_MII * MII utility commands
1118 CONFIG_CMD_MTDPARTS * MTD partition support
1119 CONFIG_CMD_NAND * NAND support
1120 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1121 CONFIG_CMD_NFS NFS support
1122 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1123 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1124 CONFIG_CMD_PCI * pciinfo
1125 CONFIG_CMD_PCMCIA * PCMCIA support
1126 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1128 CONFIG_CMD_PORTIO * Port I/O
1129 CONFIG_CMD_READ * Read raw data from partition
1130 CONFIG_CMD_REGINFO * Register dump
1131 CONFIG_CMD_RUN run command in env variable
1132 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1133 CONFIG_CMD_SAVES * save S record dump
1134 CONFIG_CMD_SCSI * SCSI Support
1135 CONFIG_CMD_SDRAM * print SDRAM configuration information
1136 (requires CONFIG_CMD_I2C)
1137 CONFIG_CMD_SETGETDCR Support for DCR Register access
1139 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1140 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1141 (requires CONFIG_CMD_MEMORY)
1142 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1143 CONFIG_CMD_SOURCE "source" command Support
1144 CONFIG_CMD_SPI * SPI serial bus support
1145 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1146 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1147 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1148 CONFIG_CMD_TIMER * access to the system tick timer
1149 CONFIG_CMD_USB * USB support
1150 CONFIG_CMD_CDP * Cisco Discover Protocol support
1151 CONFIG_CMD_MFSL * Microblaze FSL support
1152 CONFIG_CMD_XIMG Load part of Multi Image
1153 CONFIG_CMD_UUID * Generate random UUID or GUID string
1155 EXAMPLE: If you want all functions except of network
1156 support you can write:
1158 #include "config_cmd_all.h"
1159 #undef CONFIG_CMD_NET
1162 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1164 Note: Don't enable the "icache" and "dcache" commands
1165 (configuration option CONFIG_CMD_CACHE) unless you know
1166 what you (and your U-Boot users) are doing. Data
1167 cache cannot be enabled on systems like the 8xx or
1168 8260 (where accesses to the IMMR region must be
1169 uncached), and it cannot be disabled on all other
1170 systems where we (mis-) use the data cache to hold an
1171 initial stack and some data.
1174 XXX - this list needs to get updated!
1176 - Regular expression support:
1178 If this variable is defined, U-Boot is linked against
1179 the SLRE (Super Light Regular Expression) library,
1180 which adds regex support to some commands, as for
1181 example "env grep" and "setexpr".
1185 If this variable is defined, U-Boot will use a device tree
1186 to configure its devices, instead of relying on statically
1187 compiled #defines in the board file. This option is
1188 experimental and only available on a few boards. The device
1189 tree is available in the global data as gd->fdt_blob.
1191 U-Boot needs to get its device tree from somewhere. This can
1192 be done using one of the two options below:
1195 If this variable is defined, U-Boot will embed a device tree
1196 binary in its image. This device tree file should be in the
1197 board directory and called <soc>-<board>.dts. The binary file
1198 is then picked up in board_init_f() and made available through
1199 the global data structure as gd->blob.
1202 If this variable is defined, U-Boot will build a device tree
1203 binary. It will be called u-boot.dtb. Architecture-specific
1204 code will locate it at run-time. Generally this works by:
1206 cat u-boot.bin u-boot.dtb >image.bin
1208 and in fact, U-Boot does this for you, creating a file called
1209 u-boot-dtb.bin which is useful in the common case. You can
1210 still use the individual files if you need something more
1215 If this variable is defined, it enables watchdog
1216 support for the SoC. There must be support in the SoC
1217 specific code for a watchdog. For the 8xx and 8260
1218 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1219 register. When supported for a specific SoC is
1220 available, then no further board specific code should
1221 be needed to use it.
1224 When using a watchdog circuitry external to the used
1225 SoC, then define this variable and provide board
1226 specific code for the "hw_watchdog_reset" function.
1228 CONFIG_AT91_HW_WDT_TIMEOUT
1229 specify the timeout in seconds. default 2 seconds.
1232 CONFIG_VERSION_VARIABLE
1233 If this variable is defined, an environment variable
1234 named "ver" is created by U-Boot showing the U-Boot
1235 version as printed by the "version" command.
1236 Any change to this variable will be reverted at the
1241 When CONFIG_CMD_DATE is selected, the type of the RTC
1242 has to be selected, too. Define exactly one of the
1245 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1246 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1247 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1248 CONFIG_RTC_MC146818 - use MC146818 RTC
1249 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1250 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1251 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1252 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1253 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1254 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1255 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1256 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1257 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1260 Note that if the RTC uses I2C, then the I2C interface
1261 must also be configured. See I2C Support, below.
1264 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1266 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1267 chip-ngpio pairs that tell the PCA953X driver the number of
1268 pins supported by a particular chip.
1270 Note that if the GPIO device uses I2C, then the I2C interface
1271 must also be configured. See I2C Support, below.
1274 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1275 accesses and can checksum them or write a list of them out
1276 to memory. See the 'iotrace' command for details. This is
1277 useful for testing device drivers since it can confirm that
1278 the driver behaves the same way before and after a code
1279 change. Currently this is supported on sandbox and arm. To
1280 add support for your architecture, add '#include <iotrace.h>'
1281 to the bottom of arch/<arch>/include/asm/io.h and test.
1283 Example output from the 'iotrace stats' command is below.
1284 Note that if the trace buffer is exhausted, the checksum will
1285 still continue to operate.
1288 Start: 10000000 (buffer start address)
1289 Size: 00010000 (buffer size)
1290 Offset: 00000120 (current buffer offset)
1291 Output: 10000120 (start + offset)
1292 Count: 00000018 (number of trace records)
1293 CRC32: 9526fb66 (CRC32 of all trace records)
1295 - Timestamp Support:
1297 When CONFIG_TIMESTAMP is selected, the timestamp
1298 (date and time) of an image is printed by image
1299 commands like bootm or iminfo. This option is
1300 automatically enabled when you select CONFIG_CMD_DATE .
1302 - Partition Labels (disklabels) Supported:
1303 Zero or more of the following:
1304 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1305 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1306 Intel architecture, USB sticks, etc.
1307 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1308 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1309 bootloader. Note 2TB partition limit; see
1311 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1313 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1314 CONFIG_CMD_SCSI) you must configure support for at
1315 least one non-MTD partition type as well.
1318 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1319 board configurations files but used nowhere!
1321 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1322 be performed by calling the function
1323 ide_set_reset(int reset)
1324 which has to be defined in a board specific file
1329 Set this to enable ATAPI support.
1334 Set this to enable support for disks larger than 137GB
1335 Also look at CONFIG_SYS_64BIT_LBA.
1336 Whithout these , LBA48 support uses 32bit variables and will 'only'
1337 support disks up to 2.1TB.
1339 CONFIG_SYS_64BIT_LBA:
1340 When enabled, makes the IDE subsystem use 64bit sector addresses.
1344 At the moment only there is only support for the
1345 SYM53C8XX SCSI controller; define
1346 CONFIG_SCSI_SYM53C8XX to enable it.
1348 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1349 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1350 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1351 maximum numbers of LUNs, SCSI ID's and target
1353 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1355 The environment variable 'scsidevs' is set to the number of
1356 SCSI devices found during the last scan.
1358 - NETWORK Support (PCI):
1360 Support for Intel 8254x/8257x gigabit chips.
1363 Utility code for direct access to the SPI bus on Intel 8257x.
1364 This does not do anything useful unless you set at least one
1365 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1367 CONFIG_E1000_SPI_GENERIC
1368 Allow generic access to the SPI bus on the Intel 8257x, for
1369 example with the "sspi" command.
1372 Management command for E1000 devices. When used on devices
1373 with SPI support you can reprogram the EEPROM from U-Boot.
1376 Support for Intel 82557/82559/82559ER chips.
1377 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1378 write routine for first time initialisation.
1381 Support for Digital 2114x chips.
1382 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1383 modem chip initialisation (KS8761/QS6611).
1386 Support for National dp83815 chips.
1389 Support for National dp8382[01] gigabit chips.
1391 - NETWORK Support (other):
1393 CONFIG_DRIVER_AT91EMAC
1394 Support for AT91RM9200 EMAC.
1397 Define this to use reduced MII inteface
1399 CONFIG_DRIVER_AT91EMAC_QUIET
1400 If this defined, the driver is quiet.
1401 The driver doen't show link status messages.
1403 CONFIG_CALXEDA_XGMAC
1404 Support for the Calxeda XGMAC device
1407 Support for SMSC's LAN91C96 chips.
1409 CONFIG_LAN91C96_BASE
1410 Define this to hold the physical address
1411 of the LAN91C96's I/O space
1413 CONFIG_LAN91C96_USE_32_BIT
1414 Define this to enable 32 bit addressing
1417 Support for SMSC's LAN91C111 chip
1419 CONFIG_SMC91111_BASE
1420 Define this to hold the physical address
1421 of the device (I/O space)
1423 CONFIG_SMC_USE_32_BIT
1424 Define this if data bus is 32 bits
1426 CONFIG_SMC_USE_IOFUNCS
1427 Define this to use i/o functions instead of macros
1428 (some hardware wont work with macros)
1430 CONFIG_DRIVER_TI_EMAC
1431 Support for davinci emac
1433 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1434 Define this if you have more then 3 PHYs.
1437 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1439 CONFIG_FTGMAC100_EGIGA
1440 Define this to use GE link update with gigabit PHY.
1441 Define this if FTGMAC100 is connected to gigabit PHY.
1442 If your system has 10/100 PHY only, it might not occur
1443 wrong behavior. Because PHY usually return timeout or
1444 useless data when polling gigabit status and gigabit
1445 control registers. This behavior won't affect the
1446 correctnessof 10/100 link speed update.
1449 Support for SMSC's LAN911x and LAN921x chips
1452 Define this to hold the physical address
1453 of the device (I/O space)
1455 CONFIG_SMC911X_32_BIT
1456 Define this if data bus is 32 bits
1458 CONFIG_SMC911X_16_BIT
1459 Define this if data bus is 16 bits. If your processor
1460 automatically converts one 32 bit word to two 16 bit
1461 words you may also try CONFIG_SMC911X_32_BIT.
1464 Support for Renesas on-chip Ethernet controller
1466 CONFIG_SH_ETHER_USE_PORT
1467 Define the number of ports to be used
1469 CONFIG_SH_ETHER_PHY_ADDR
1470 Define the ETH PHY's address
1472 CONFIG_SH_ETHER_CACHE_WRITEBACK
1473 If this option is set, the driver enables cache flush.
1477 Support for PWM modul on the imx6.
1481 Support TPM devices.
1484 Support for i2c bus TPM devices. Only one device
1485 per system is supported at this time.
1487 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1488 Define the burst count bytes upper limit
1490 CONFIG_TPM_ATMEL_TWI
1491 Support for Atmel TWI TPM device. Requires I2C support.
1494 Support for generic parallel port TPM devices. Only one device
1495 per system is supported at this time.
1497 CONFIG_TPM_TIS_BASE_ADDRESS
1498 Base address where the generic TPM device is mapped
1499 to. Contemporary x86 systems usually map it at
1503 Add tpm monitor functions.
1504 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1505 provides monitor access to authorized functions.
1508 Define this to enable the TPM support library which provides
1509 functional interfaces to some TPM commands.
1510 Requires support for a TPM device.
1512 CONFIG_TPM_AUTH_SESSIONS
1513 Define this to enable authorized functions in the TPM library.
1514 Requires CONFIG_TPM and CONFIG_SHA1.
1517 At the moment only the UHCI host controller is
1518 supported (PIP405, MIP405, MPC5200); define
1519 CONFIG_USB_UHCI to enable it.
1520 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1521 and define CONFIG_USB_STORAGE to enable the USB
1524 Supported are USB Keyboards and USB Floppy drives
1526 MPC5200 USB requires additional defines:
1528 for 528 MHz Clock: 0x0001bbbb
1532 for differential drivers: 0x00001000
1533 for single ended drivers: 0x00005000
1534 for differential drivers on PSC3: 0x00000100
1535 for single ended drivers on PSC3: 0x00004100
1536 CONFIG_SYS_USB_EVENT_POLL
1537 May be defined to allow interrupt polling
1538 instead of using asynchronous interrupts
1540 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1541 txfilltuning field in the EHCI controller on reset.
1543 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1544 HW module registers.
1547 Define the below if you wish to use the USB console.
1548 Once firmware is rebuilt from a serial console issue the
1549 command "setenv stdin usbtty; setenv stdout usbtty" and
1550 attach your USB cable. The Unix command "dmesg" should print
1551 it has found a new device. The environment variable usbtty
1552 can be set to gserial or cdc_acm to enable your device to
1553 appear to a USB host as a Linux gserial device or a
1554 Common Device Class Abstract Control Model serial device.
1555 If you select usbtty = gserial you should be able to enumerate
1557 # modprobe usbserial vendor=0xVendorID product=0xProductID
1558 else if using cdc_acm, simply setting the environment
1559 variable usbtty to be cdc_acm should suffice. The following
1560 might be defined in YourBoardName.h
1563 Define this to build a UDC device
1566 Define this to have a tty type of device available to
1567 talk to the UDC device
1570 Define this to enable the high speed support for usb
1571 device and usbtty. If this feature is enabled, a routine
1572 int is_usbd_high_speed(void)
1573 also needs to be defined by the driver to dynamically poll
1574 whether the enumeration has succeded at high speed or full
1577 CONFIG_SYS_CONSOLE_IS_IN_ENV
1578 Define this if you want stdin, stdout &/or stderr to
1582 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1583 Derive USB clock from external clock "blah"
1584 - CONFIG_SYS_USB_EXTC_CLK 0x02
1586 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1587 Derive USB clock from brgclk
1588 - CONFIG_SYS_USB_BRG_CLK 0x04
1590 If you have a USB-IF assigned VendorID then you may wish to
1591 define your own vendor specific values either in BoardName.h
1592 or directly in usbd_vendor_info.h. If you don't define
1593 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1594 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1595 should pretend to be a Linux device to it's target host.
1597 CONFIG_USBD_MANUFACTURER
1598 Define this string as the name of your company for
1599 - CONFIG_USBD_MANUFACTURER "my company"
1601 CONFIG_USBD_PRODUCT_NAME
1602 Define this string as the name of your product
1603 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1605 CONFIG_USBD_VENDORID
1606 Define this as your assigned Vendor ID from the USB
1607 Implementors Forum. This *must* be a genuine Vendor ID
1608 to avoid polluting the USB namespace.
1609 - CONFIG_USBD_VENDORID 0xFFFF
1611 CONFIG_USBD_PRODUCTID
1612 Define this as the unique Product ID
1614 - CONFIG_USBD_PRODUCTID 0xFFFF
1616 - ULPI Layer Support:
1617 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1618 the generic ULPI layer. The generic layer accesses the ULPI PHY
1619 via the platform viewport, so you need both the genric layer and
1620 the viewport enabled. Currently only Chipidea/ARC based
1621 viewport is supported.
1622 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1623 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1624 If your ULPI phy needs a different reference clock than the
1625 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1626 the appropriate value in Hz.
1629 The MMC controller on the Intel PXA is supported. To
1630 enable this define CONFIG_MMC. The MMC can be
1631 accessed from the boot prompt by mapping the device
1632 to physical memory similar to flash. Command line is
1633 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1634 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1637 Support for Renesas on-chip MMCIF controller
1639 CONFIG_SH_MMCIF_ADDR
1640 Define the base address of MMCIF registers
1643 Define the clock frequency for MMCIF
1646 Enable the generic MMC driver
1648 CONFIG_SUPPORT_EMMC_BOOT
1649 Enable some additional features of the eMMC boot partitions.
1651 CONFIG_SUPPORT_EMMC_RPMB
1652 Enable the commands for reading, writing and programming the
1653 key for the Replay Protection Memory Block partition in eMMC.
1655 - USB Device Firmware Update (DFU) class support:
1656 CONFIG_USB_FUNCTION_DFU
1657 This enables the USB portion of the DFU USB class
1660 This enables the command "dfu" which is used to have
1661 U-Boot create a DFU class device via USB. This command
1662 requires that the "dfu_alt_info" environment variable be
1663 set and define the alt settings to expose to the host.
1666 This enables support for exposing (e)MMC devices via DFU.
1669 This enables support for exposing NAND devices via DFU.
1672 This enables support for exposing RAM via DFU.
1673 Note: DFU spec refer to non-volatile memory usage, but
1674 allow usages beyond the scope of spec - here RAM usage,
1675 one that would help mostly the developer.
1677 CONFIG_SYS_DFU_DATA_BUF_SIZE
1678 Dfu transfer uses a buffer before writing data to the
1679 raw storage device. Make the size (in bytes) of this buffer
1680 configurable. The size of this buffer is also configurable
1681 through the "dfu_bufsiz" environment variable.
1683 CONFIG_SYS_DFU_MAX_FILE_SIZE
1684 When updating files rather than the raw storage device,
1685 we use a static buffer to copy the file into and then write
1686 the buffer once we've been given the whole file. Define
1687 this to the maximum filesize (in bytes) for the buffer.
1688 Default is 4 MiB if undefined.
1690 DFU_DEFAULT_POLL_TIMEOUT
1691 Poll timeout [ms], is the timeout a device can send to the
1692 host. The host must wait for this timeout before sending
1693 a subsequent DFU_GET_STATUS request to the device.
1695 DFU_MANIFEST_POLL_TIMEOUT
1696 Poll timeout [ms], which the device sends to the host when
1697 entering dfuMANIFEST state. Host waits this timeout, before
1698 sending again an USB request to the device.
1700 - USB Device Android Fastboot support:
1701 CONFIG_USB_FUNCTION_FASTBOOT
1702 This enables the USB part of the fastboot gadget
1705 This enables the command "fastboot" which enables the Android
1706 fastboot mode for the platform's USB device. Fastboot is a USB
1707 protocol for downloading images, flashing and device control
1708 used on Android devices.
1709 See doc/README.android-fastboot for more information.
1711 CONFIG_ANDROID_BOOT_IMAGE
1712 This enables support for booting images which use the Android
1713 image format header.
1715 CONFIG_FASTBOOT_BUF_ADDR
1716 The fastboot protocol requires a large memory buffer for
1717 downloads. Define this to the starting RAM address to use for
1720 CONFIG_FASTBOOT_BUF_SIZE
1721 The fastboot protocol requires a large memory buffer for
1722 downloads. This buffer should be as large as possible for a
1723 platform. Define this to the size available RAM for fastboot.
1725 CONFIG_FASTBOOT_FLASH
1726 The fastboot protocol includes a "flash" command for writing
1727 the downloaded image to a non-volatile storage device. Define
1728 this to enable the "fastboot flash" command.
1730 CONFIG_FASTBOOT_FLASH_MMC_DEV
1731 The fastboot "flash" command requires additional information
1732 regarding the non-volatile storage device. Define this to
1733 the eMMC device that fastboot should use to store the image.
1735 CONFIG_FASTBOOT_GPT_NAME
1736 The fastboot "flash" command supports writing the downloaded
1737 image to the Protective MBR and the Primary GUID Partition
1738 Table. (Additionally, this downloaded image is post-processed
1739 to generate and write the Backup GUID Partition Table.)
1740 This occurs when the specified "partition name" on the
1741 "fastboot flash" command line matches this value.
1742 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1744 - Journaling Flash filesystem support:
1745 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1746 CONFIG_JFFS2_NAND_DEV
1747 Define these for a default partition on a NAND device
1749 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1750 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1751 Define these for a default partition on a NOR device
1753 CONFIG_SYS_JFFS_CUSTOM_PART
1754 Define this to create an own partition. You have to provide a
1755 function struct part_info* jffs2_part_info(int part_num)
1757 If you define only one JFFS2 partition you may also want to
1758 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1759 to disable the command chpart. This is the default when you
1760 have not defined a custom partition
1762 - FAT(File Allocation Table) filesystem write function support:
1765 Define this to enable support for saving memory data as a
1766 file in FAT formatted partition.
1768 This will also enable the command "fatwrite" enabling the
1769 user to write files to FAT.
1771 CBFS (Coreboot Filesystem) support
1774 Define this to enable support for reading from a Coreboot
1775 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1778 - FAT(File Allocation Table) filesystem cluster size:
1779 CONFIG_FS_FAT_MAX_CLUSTSIZE
1781 Define the max cluster size for fat operations else
1782 a default value of 65536 will be defined.
1787 Define this to enable standard (PC-Style) keyboard
1791 Standard PC keyboard driver with US (is default) and
1792 GERMAN key layout (switch via environment 'keymap=de') support.
1793 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1794 for cfb_console. Supports cursor blinking.
1797 Enables a Chrome OS keyboard using the CROS_EC interface.
1798 This uses CROS_EC to communicate with a second microcontroller
1799 which provides key scans on request.
1804 Define this to enable video support (for output to
1807 CONFIG_VIDEO_CT69000
1809 Enable Chips & Technologies 69000 Video chip
1811 CONFIG_VIDEO_SMI_LYNXEM
1812 Enable Silicon Motion SMI 712/710/810 Video chip. The
1813 video output is selected via environment 'videoout'
1814 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1817 For the CT69000 and SMI_LYNXEM drivers, videomode is
1818 selected via environment 'videomode'. Two different ways
1820 - "videomode=num" 'num' is a standard LiLo mode numbers.
1821 Following standard modes are supported (* is default):
1823 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1824 -------------+---------------------------------------------
1825 8 bits | 0x301* 0x303 0x305 0x161 0x307
1826 15 bits | 0x310 0x313 0x316 0x162 0x319
1827 16 bits | 0x311 0x314 0x317 0x163 0x31A
1828 24 bits | 0x312 0x315 0x318 ? 0x31B
1829 -------------+---------------------------------------------
1830 (i.e. setenv videomode 317; saveenv; reset;)
1832 - "videomode=bootargs" all the video parameters are parsed
1833 from the bootargs. (See drivers/video/videomodes.c)
1836 CONFIG_VIDEO_SED13806
1837 Enable Epson SED13806 driver. This driver supports 8bpp
1838 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1839 or CONFIG_VIDEO_SED13806_16BPP
1842 Enable the Freescale DIU video driver. Reference boards for
1843 SOCs that have a DIU should define this macro to enable DIU
1844 support, and should also define these other macros:
1850 CONFIG_VIDEO_SW_CURSOR
1851 CONFIG_VGA_AS_SINGLE_DEVICE
1853 CONFIG_VIDEO_BMP_LOGO
1855 The DIU driver will look for the 'video-mode' environment
1856 variable, and if defined, enable the DIU as a console during
1857 boot. See the documentation file README.video for a
1858 description of this variable.
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 Sometimes, for example if the display is mounted in portrait
1939 mode or even if it's mounted landscape but rotated by 180degree,
1940 we need to rotate our content of the display relative to the
1941 framebuffer, so that user can read the messages which are
1943 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1944 initialized with a given rotation from "vl_rot" out of
1945 "vidinfo_t" which is provided by the board specific code.
1946 The value for vl_rot is coded as following (matching to
1947 fbcon=rotate:<n> linux-kernel commandline):
1948 0 = no rotation respectively 0 degree
1949 1 = 90 degree rotation
1950 2 = 180 degree rotation
1951 3 = 270 degree rotation
1953 If CONFIG_LCD_ROTATION is not defined, the console will be
1954 initialized with 0degree rotation.
1958 Support drawing of RLE8-compressed bitmaps on the LCD.
1962 Enables an 'i2c edid' command which can read EDID
1963 information over I2C from an attached LCD display.
1965 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1967 If this option is set, the environment is checked for
1968 a variable "splashimage". If found, the usual display
1969 of logo, copyright and system information on the LCD
1970 is suppressed and the BMP image at the address
1971 specified in "splashimage" is loaded instead. The
1972 console is redirected to the "nulldev", too. This
1973 allows for a "silent" boot where a splash screen is
1974 loaded very quickly after power-on.
1976 CONFIG_SPLASHIMAGE_GUARD
1978 If this option is set, then U-Boot will prevent the environment
1979 variable "splashimage" from being set to a problematic address
1980 (see README.displaying-bmps).
1981 This option is useful for targets where, due to alignment
1982 restrictions, an improperly aligned BMP image will cause a data
1983 abort. If you think you will not have problems with unaligned
1984 accesses (for example because your toolchain prevents them)
1985 there is no need to set this option.
1987 CONFIG_SPLASH_SCREEN_ALIGN
1989 If this option is set the splash image can be freely positioned
1990 on the screen. Environment variable "splashpos" specifies the
1991 position as "x,y". If a positive number is given it is used as
1992 number of pixel from left/top. If a negative number is given it
1993 is used as number of pixel from right/bottom. You can also
1994 specify 'm' for centering the image.
1997 setenv splashpos m,m
1998 => image at center of screen
2000 setenv splashpos 30,20
2001 => image at x = 30 and y = 20
2003 setenv splashpos -10,m
2004 => vertically centered image
2005 at x = dspWidth - bmpWidth - 9
2007 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2009 If this option is set, additionally to standard BMP
2010 images, gzipped BMP images can be displayed via the
2011 splashscreen support or the bmp command.
2013 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2015 If this option is set, 8-bit RLE compressed BMP images
2016 can be displayed via the splashscreen support or the
2019 - Do compressing for memory range:
2022 If this option is set, it would use zlib deflate method
2023 to compress the specified memory at its best effort.
2025 - Compression support:
2028 Enabled by default to support gzip compressed images.
2032 If this option is set, support for bzip2 compressed
2033 images is included. If not, only uncompressed and gzip
2034 compressed images are supported.
2036 NOTE: the bzip2 algorithm requires a lot of RAM, so
2037 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2042 If this option is set, support for lzma compressed
2045 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2046 requires an amount of dynamic memory that is given by the
2049 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2051 Where lc and lp stand for, respectively, Literal context bits
2052 and Literal pos bits.
2054 This value is upper-bounded by 14MB in the worst case. Anyway,
2055 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2056 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2057 a very small buffer.
2059 Use the lzmainfo tool to determinate the lc and lp values and
2060 then calculate the amount of needed dynamic memory (ensuring
2061 the appropriate CONFIG_SYS_MALLOC_LEN value).
2065 If this option is set, support for LZO compressed images
2071 The address of PHY on MII bus.
2073 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2075 The clock frequency of the MII bus
2079 If this option is set, support for speed/duplex
2080 detection of gigabit PHY is included.
2082 CONFIG_PHY_RESET_DELAY
2084 Some PHY like Intel LXT971A need extra delay after
2085 reset before any MII register access is possible.
2086 For such PHY, set this option to the usec delay
2087 required. (minimum 300usec for LXT971A)
2089 CONFIG_PHY_CMD_DELAY (ppc4xx)
2091 Some PHY like Intel LXT971A need extra delay after
2092 command issued before MII status register can be read
2097 Define a default value for the IP address to use for
2098 the default Ethernet interface, in case this is not
2099 determined through e.g. bootp.
2100 (Environment variable "ipaddr")
2102 - Server IP address:
2105 Defines a default value for the IP address of a TFTP
2106 server to contact when using the "tftboot" command.
2107 (Environment variable "serverip")
2109 CONFIG_KEEP_SERVERADDR
2111 Keeps the server's MAC address, in the env 'serveraddr'
2112 for passing to bootargs (like Linux's netconsole option)
2114 - Gateway IP address:
2117 Defines a default value for the IP address of the
2118 default router where packets to other networks are
2120 (Environment variable "gatewayip")
2125 Defines a default value for the subnet mask (or
2126 routing prefix) which is used to determine if an IP
2127 address belongs to the local subnet or needs to be
2128 forwarded through a router.
2129 (Environment variable "netmask")
2131 - Multicast TFTP Mode:
2134 Defines whether you want to support multicast TFTP as per
2135 rfc-2090; for example to work with atftp. Lets lots of targets
2136 tftp down the same boot image concurrently. Note: the Ethernet
2137 driver in use must provide a function: mcast() to join/leave a
2140 - BOOTP Recovery Mode:
2141 CONFIG_BOOTP_RANDOM_DELAY
2143 If you have many targets in a network that try to
2144 boot using BOOTP, you may want to avoid that all
2145 systems send out BOOTP requests at precisely the same
2146 moment (which would happen for instance at recovery
2147 from a power failure, when all systems will try to
2148 boot, thus flooding the BOOTP server. Defining
2149 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2150 inserted before sending out BOOTP requests. The
2151 following delays are inserted then:
2153 1st BOOTP request: delay 0 ... 1 sec
2154 2nd BOOTP request: delay 0 ... 2 sec
2155 3rd BOOTP request: delay 0 ... 4 sec
2157 BOOTP requests: delay 0 ... 8 sec
2159 CONFIG_BOOTP_ID_CACHE_SIZE
2161 BOOTP packets are uniquely identified using a 32-bit ID. The
2162 server will copy the ID from client requests to responses and
2163 U-Boot will use this to determine if it is the destination of
2164 an incoming response. Some servers will check that addresses
2165 aren't in use before handing them out (usually using an ARP
2166 ping) and therefore take up to a few hundred milliseconds to
2167 respond. Network congestion may also influence the time it
2168 takes for a response to make it back to the client. If that
2169 time is too long, U-Boot will retransmit requests. In order
2170 to allow earlier responses to still be accepted after these
2171 retransmissions, U-Boot's BOOTP client keeps a small cache of
2172 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2173 cache. The default is to keep IDs for up to four outstanding
2174 requests. Increasing this will allow U-Boot to accept offers
2175 from a BOOTP client in networks with unusually high latency.
2177 - DHCP Advanced Options:
2178 You can fine tune the DHCP functionality by defining
2179 CONFIG_BOOTP_* symbols:
2181 CONFIG_BOOTP_SUBNETMASK
2182 CONFIG_BOOTP_GATEWAY
2183 CONFIG_BOOTP_HOSTNAME
2184 CONFIG_BOOTP_NISDOMAIN
2185 CONFIG_BOOTP_BOOTPATH
2186 CONFIG_BOOTP_BOOTFILESIZE
2189 CONFIG_BOOTP_SEND_HOSTNAME
2190 CONFIG_BOOTP_NTPSERVER
2191 CONFIG_BOOTP_TIMEOFFSET
2192 CONFIG_BOOTP_VENDOREX
2193 CONFIG_BOOTP_MAY_FAIL
2195 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2196 environment variable, not the BOOTP server.
2198 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2199 after the configured retry count, the call will fail
2200 instead of starting over. This can be used to fail over
2201 to Link-local IP address configuration if the DHCP server
2204 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2205 serverip from a DHCP server, it is possible that more
2206 than one DNS serverip is offered to the client.
2207 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2208 serverip will be stored in the additional environment
2209 variable "dnsip2". The first DNS serverip is always
2210 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2213 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2214 to do a dynamic update of a DNS server. To do this, they
2215 need the hostname of the DHCP requester.
2216 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2217 of the "hostname" environment variable is passed as
2218 option 12 to the DHCP server.
2220 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2222 A 32bit value in microseconds for a delay between
2223 receiving a "DHCP Offer" and sending the "DHCP Request".
2224 This fixes a problem with certain DHCP servers that don't
2225 respond 100% of the time to a "DHCP request". E.g. On an
2226 AT91RM9200 processor running at 180MHz, this delay needed
2227 to be *at least* 15,000 usec before a Windows Server 2003
2228 DHCP server would reply 100% of the time. I recommend at
2229 least 50,000 usec to be safe. The alternative is to hope
2230 that one of the retries will be successful but note that
2231 the DHCP timeout and retry process takes a longer than
2234 - Link-local IP address negotiation:
2235 Negotiate with other link-local clients on the local network
2236 for an address that doesn't require explicit configuration.
2237 This is especially useful if a DHCP server cannot be guaranteed
2238 to exist in all environments that the device must operate.
2240 See doc/README.link-local for more information.
2243 CONFIG_CDP_DEVICE_ID
2245 The device id used in CDP trigger frames.
2247 CONFIG_CDP_DEVICE_ID_PREFIX
2249 A two character string which is prefixed to the MAC address
2254 A printf format string which contains the ascii name of
2255 the port. Normally is set to "eth%d" which sets
2256 eth0 for the first Ethernet, eth1 for the second etc.
2258 CONFIG_CDP_CAPABILITIES
2260 A 32bit integer which indicates the device capabilities;
2261 0x00000010 for a normal host which does not forwards.
2265 An ascii string containing the version of the software.
2269 An ascii string containing the name of the platform.
2273 A 32bit integer sent on the trigger.
2275 CONFIG_CDP_POWER_CONSUMPTION
2277 A 16bit integer containing the power consumption of the
2278 device in .1 of milliwatts.
2280 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2282 A byte containing the id of the VLAN.
2284 - Status LED: CONFIG_STATUS_LED
2286 Several configurations allow to display the current
2287 status using a LED. For instance, the LED will blink
2288 fast while running U-Boot code, stop blinking as
2289 soon as a reply to a BOOTP request was received, and
2290 start blinking slow once the Linux kernel is running
2291 (supported by a status LED driver in the Linux
2292 kernel). Defining CONFIG_STATUS_LED enables this
2298 The status LED can be connected to a GPIO pin.
2299 In such cases, the gpio_led driver can be used as a
2300 status LED backend implementation. Define CONFIG_GPIO_LED
2301 to include the gpio_led driver in the U-Boot binary.
2303 CONFIG_GPIO_LED_INVERTED_TABLE
2304 Some GPIO connected LEDs may have inverted polarity in which
2305 case the GPIO high value corresponds to LED off state and
2306 GPIO low value corresponds to LED on state.
2307 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2308 with a list of GPIO LEDs that have inverted polarity.
2310 - CAN Support: CONFIG_CAN_DRIVER
2312 Defining CONFIG_CAN_DRIVER enables CAN driver support
2313 on those systems that support this (optional)
2314 feature, like the TQM8xxL modules.
2316 - I2C Support: CONFIG_SYS_I2C
2318 This enable the NEW i2c subsystem, and will allow you to use
2319 i2c commands at the u-boot command line (as long as you set
2320 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2321 based realtime clock chips or other i2c devices. See
2322 common/cmd_i2c.c for a description of the command line
2325 ported i2c driver to the new framework:
2326 - drivers/i2c/soft_i2c.c:
2327 - activate first bus with CONFIG_SYS_I2C_SOFT define
2328 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2329 for defining speed and slave address
2330 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2331 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2332 for defining speed and slave address
2333 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2334 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2335 for defining speed and slave address
2336 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2337 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2338 for defining speed and slave address
2340 - drivers/i2c/fsl_i2c.c:
2341 - activate i2c driver with CONFIG_SYS_I2C_FSL
2342 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2343 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2344 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2346 - If your board supports a second fsl i2c bus, define
2347 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2348 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2349 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2352 - drivers/i2c/tegra_i2c.c:
2353 - activate this driver with CONFIG_SYS_I2C_TEGRA
2354 - This driver adds 4 i2c buses with a fix speed from
2355 100000 and the slave addr 0!
2357 - drivers/i2c/ppc4xx_i2c.c
2358 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2359 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2360 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2362 - drivers/i2c/i2c_mxc.c
2363 - activate this driver with CONFIG_SYS_I2C_MXC
2364 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2365 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2366 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2367 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2368 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2369 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2370 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2371 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2372 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2373 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2374 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2375 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2376 If those defines are not set, default value is 100000
2377 for speed, and 0 for slave.
2379 - drivers/i2c/rcar_i2c.c:
2380 - activate this driver with CONFIG_SYS_I2C_RCAR
2381 - This driver adds 4 i2c buses
2383 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2384 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2385 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2386 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2387 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2388 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2389 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2390 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2391 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2393 - drivers/i2c/sh_i2c.c:
2394 - activate this driver with CONFIG_SYS_I2C_SH
2395 - This driver adds from 2 to 5 i2c buses
2397 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2398 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2399 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2400 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2401 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2402 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2403 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2404 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2405 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2406 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2407 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2408 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2409 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2411 - drivers/i2c/omap24xx_i2c.c
2412 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2413 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2414 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2415 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2416 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2417 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2418 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2419 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2420 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2421 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2422 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2424 - drivers/i2c/zynq_i2c.c
2425 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2426 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2427 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2429 - drivers/i2c/s3c24x0_i2c.c:
2430 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2431 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2432 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2433 with a fix speed from 100000 and the slave addr 0!
2435 - drivers/i2c/ihs_i2c.c
2436 - activate this driver with CONFIG_SYS_I2C_IHS
2437 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2438 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2439 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2440 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2441 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2442 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2443 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2444 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2445 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2446 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2447 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2448 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2452 CONFIG_SYS_NUM_I2C_BUSES
2453 Hold the number of i2c buses you want to use. If you
2454 don't use/have i2c muxes on your i2c bus, this
2455 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2458 CONFIG_SYS_I2C_DIRECT_BUS
2459 define this, if you don't use i2c muxes on your hardware.
2460 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2463 CONFIG_SYS_I2C_MAX_HOPS
2464 define how many muxes are maximal consecutively connected
2465 on one i2c bus. If you not use i2c muxes, omit this
2468 CONFIG_SYS_I2C_BUSES
2469 hold a list of buses you want to use, only used if
2470 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2471 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2472 CONFIG_SYS_NUM_I2C_BUSES = 9:
2474 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2475 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2476 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2477 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2478 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2479 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2480 {1, {I2C_NULL_HOP}}, \
2481 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2482 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2486 bus 0 on adapter 0 without a mux
2487 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2488 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2489 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2490 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2491 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2492 bus 6 on adapter 1 without a mux
2493 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2494 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2496 If you do not have i2c muxes on your board, omit this define.
2498 - Legacy I2C Support: CONFIG_HARD_I2C
2500 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2501 provides the following compelling advantages:
2503 - more than one i2c adapter is usable
2504 - approved multibus support
2505 - better i2c mux support
2507 ** Please consider updating your I2C driver now. **
2509 These enable legacy I2C serial bus commands. Defining
2510 CONFIG_HARD_I2C will include the appropriate I2C driver
2511 for the selected CPU.
2513 This will allow you to use i2c commands at the u-boot
2514 command line (as long as you set CONFIG_CMD_I2C in
2515 CONFIG_COMMANDS) and communicate with i2c based realtime
2516 clock chips. See common/cmd_i2c.c for a description of the
2517 command line interface.
2519 CONFIG_HARD_I2C selects a hardware I2C controller.
2521 There are several other quantities that must also be
2522 defined when you define CONFIG_HARD_I2C.
2524 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2525 to be the frequency (in Hz) at which you wish your i2c bus
2526 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2527 the CPU's i2c node address).
2529 Now, the u-boot i2c code for the mpc8xx
2530 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2531 and so its address should therefore be cleared to 0 (See,
2532 eg, MPC823e User's Manual p.16-473). So, set
2533 CONFIG_SYS_I2C_SLAVE to 0.
2535 CONFIG_SYS_I2C_INIT_MPC5XXX
2537 When a board is reset during an i2c bus transfer
2538 chips might think that the current transfer is still
2539 in progress. Reset the slave devices by sending start
2540 commands until the slave device responds.
2542 That's all that's required for CONFIG_HARD_I2C.
2544 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2545 then the following macros need to be defined (examples are
2546 from include/configs/lwmon.h):
2550 (Optional). Any commands necessary to enable the I2C
2551 controller or configure ports.
2553 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2557 (Only for MPC8260 CPU). The I/O port to use (the code
2558 assumes both bits are on the same port). Valid values
2559 are 0..3 for ports A..D.
2563 The code necessary to make the I2C data line active
2564 (driven). If the data line is open collector, this
2567 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2571 The code necessary to make the I2C data line tri-stated
2572 (inactive). If the data line is open collector, this
2575 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2579 Code that returns true if the I2C data line is high,
2582 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2586 If <bit> is true, sets the I2C data line high. If it
2587 is false, it clears it (low).
2589 eg: #define I2C_SDA(bit) \
2590 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2591 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2595 If <bit> is true, sets the I2C clock line high. If it
2596 is false, it clears it (low).
2598 eg: #define I2C_SCL(bit) \
2599 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2600 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2604 This delay is invoked four times per clock cycle so this
2605 controls the rate of data transfer. The data rate thus
2606 is 1 / (I2C_DELAY * 4). Often defined to be something
2609 #define I2C_DELAY udelay(2)
2611 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2613 If your arch supports the generic GPIO framework (asm/gpio.h),
2614 then you may alternatively define the two GPIOs that are to be
2615 used as SCL / SDA. Any of the previous I2C_xxx macros will
2616 have GPIO-based defaults assigned to them as appropriate.
2618 You should define these to the GPIO value as given directly to
2619 the generic GPIO functions.
2621 CONFIG_SYS_I2C_INIT_BOARD
2623 When a board is reset during an i2c bus transfer
2624 chips might think that the current transfer is still
2625 in progress. On some boards it is possible to access
2626 the i2c SCLK line directly, either by using the
2627 processor pin as a GPIO or by having a second pin
2628 connected to the bus. If this option is defined a
2629 custom i2c_init_board() routine in boards/xxx/board.c
2630 is run early in the boot sequence.
2632 CONFIG_SYS_I2C_BOARD_LATE_INIT
2634 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2635 defined a custom i2c_board_late_init() routine in
2636 boards/xxx/board.c is run AFTER the operations in i2c_init()
2637 is completed. This callpoint can be used to unreset i2c bus
2638 using CPU i2c controller register accesses for CPUs whose i2c
2639 controller provide such a method. It is called at the end of
2640 i2c_init() to allow i2c_init operations to setup the i2c bus
2641 controller on the CPU (e.g. setting bus speed & slave address).
2643 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2645 This option enables configuration of bi_iic_fast[] flags
2646 in u-boot bd_info structure based on u-boot environment
2647 variable "i2cfast". (see also i2cfast)
2649 CONFIG_I2C_MULTI_BUS
2651 This option allows the use of multiple I2C buses, each of which
2652 must have a controller. At any point in time, only one bus is
2653 active. To switch to a different bus, use the 'i2c dev' command.
2654 Note that bus numbering is zero-based.
2656 CONFIG_SYS_I2C_NOPROBES
2658 This option specifies a list of I2C devices that will be skipped
2659 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2660 is set, specify a list of bus-device pairs. Otherwise, specify
2661 a 1D array of device addresses
2664 #undef CONFIG_I2C_MULTI_BUS
2665 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2667 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2669 #define CONFIG_I2C_MULTI_BUS
2670 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2672 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2674 CONFIG_SYS_SPD_BUS_NUM
2676 If defined, then this indicates the I2C bus number for DDR SPD.
2677 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2679 CONFIG_SYS_RTC_BUS_NUM
2681 If defined, then this indicates the I2C bus number for the RTC.
2682 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2684 CONFIG_SYS_DTT_BUS_NUM
2686 If defined, then this indicates the I2C bus number for the DTT.
2687 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2689 CONFIG_SYS_I2C_DTT_ADDR:
2691 If defined, specifies the I2C address of the DTT device.
2692 If not defined, then U-Boot uses predefined value for
2693 specified DTT device.
2695 CONFIG_SOFT_I2C_READ_REPEATED_START
2697 defining this will force the i2c_read() function in
2698 the soft_i2c driver to perform an I2C repeated start
2699 between writing the address pointer and reading the
2700 data. If this define is omitted the default behaviour
2701 of doing a stop-start sequence will be used. Most I2C
2702 devices can use either method, but some require one or
2705 - SPI Support: CONFIG_SPI
2707 Enables SPI driver (so far only tested with
2708 SPI EEPROM, also an instance works with Crystal A/D and
2709 D/As on the SACSng board)
2713 Enables the driver for SPI controller on SuperH. Currently
2714 only SH7757 is supported.
2718 Enables extended (16-bit) SPI EEPROM addressing.
2719 (symmetrical to CONFIG_I2C_X)
2723 Enables a software (bit-bang) SPI driver rather than
2724 using hardware support. This is a general purpose
2725 driver that only requires three general I/O port pins
2726 (two outputs, one input) to function. If this is
2727 defined, the board configuration must define several
2728 SPI configuration items (port pins to use, etc). For
2729 an example, see include/configs/sacsng.h.
2733 Enables a hardware SPI driver for general-purpose reads
2734 and writes. As with CONFIG_SOFT_SPI, the board configuration
2735 must define a list of chip-select function pointers.
2736 Currently supported on some MPC8xxx processors. For an
2737 example, see include/configs/mpc8349emds.h.
2741 Enables the driver for the SPI controllers on i.MX and MXC
2742 SoCs. Currently i.MX31/35/51 are supported.
2744 CONFIG_SYS_SPI_MXC_WAIT
2745 Timeout for waiting until spi transfer completed.
2746 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2748 - FPGA Support: CONFIG_FPGA
2750 Enables FPGA subsystem.
2752 CONFIG_FPGA_<vendor>
2754 Enables support for specific chip vendors.
2757 CONFIG_FPGA_<family>
2759 Enables support for FPGA family.
2760 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2764 Specify the number of FPGA devices to support.
2766 CONFIG_CMD_FPGA_LOADMK
2768 Enable support for fpga loadmk command
2770 CONFIG_CMD_FPGA_LOADP
2772 Enable support for fpga loadp command - load partial bitstream
2774 CONFIG_CMD_FPGA_LOADBP
2776 Enable support for fpga loadbp command - load partial bitstream
2779 CONFIG_SYS_FPGA_PROG_FEEDBACK
2781 Enable printing of hash marks during FPGA configuration.
2783 CONFIG_SYS_FPGA_CHECK_BUSY
2785 Enable checks on FPGA configuration interface busy
2786 status by the configuration function. This option
2787 will require a board or device specific function to
2792 If defined, a function that provides delays in the FPGA
2793 configuration driver.
2795 CONFIG_SYS_FPGA_CHECK_CTRLC
2796 Allow Control-C to interrupt FPGA configuration
2798 CONFIG_SYS_FPGA_CHECK_ERROR
2800 Check for configuration errors during FPGA bitfile
2801 loading. For example, abort during Virtex II
2802 configuration if the INIT_B line goes low (which
2803 indicated a CRC error).
2805 CONFIG_SYS_FPGA_WAIT_INIT
2807 Maximum time to wait for the INIT_B line to de-assert
2808 after PROB_B has been de-asserted during a Virtex II
2809 FPGA configuration sequence. The default time is 500
2812 CONFIG_SYS_FPGA_WAIT_BUSY
2814 Maximum time to wait for BUSY to de-assert during
2815 Virtex II FPGA configuration. The default is 5 ms.
2817 CONFIG_SYS_FPGA_WAIT_CONFIG
2819 Time to wait after FPGA configuration. The default is
2822 - Configuration Management:
2825 Some SoCs need special image types (e.g. U-Boot binary
2826 with a special header) as build targets. By defining
2827 CONFIG_BUILD_TARGET in the SoC / board header, this
2828 special image will be automatically built upon calling
2833 If defined, this string will be added to the U-Boot
2834 version information (U_BOOT_VERSION)
2836 - Vendor Parameter Protection:
2838 U-Boot considers the values of the environment
2839 variables "serial#" (Board Serial Number) and
2840 "ethaddr" (Ethernet Address) to be parameters that
2841 are set once by the board vendor / manufacturer, and
2842 protects these variables from casual modification by
2843 the user. Once set, these variables are read-only,
2844 and write or delete attempts are rejected. You can
2845 change this behaviour:
2847 If CONFIG_ENV_OVERWRITE is #defined in your config
2848 file, the write protection for vendor parameters is
2849 completely disabled. Anybody can change or delete
2852 Alternatively, if you define _both_ an ethaddr in the
2853 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2854 Ethernet address is installed in the environment,
2855 which can be changed exactly ONCE by the user. [The
2856 serial# is unaffected by this, i. e. it remains
2859 The same can be accomplished in a more flexible way
2860 for any variable by configuring the type of access
2861 to allow for those variables in the ".flags" variable
2862 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2867 Define this variable to enable the reservation of
2868 "protected RAM", i. e. RAM which is not overwritten
2869 by U-Boot. Define CONFIG_PRAM to hold the number of
2870 kB you want to reserve for pRAM. You can overwrite
2871 this default value by defining an environment
2872 variable "pram" to the number of kB you want to
2873 reserve. Note that the board info structure will
2874 still show the full amount of RAM. If pRAM is
2875 reserved, a new environment variable "mem" will
2876 automatically be defined to hold the amount of
2877 remaining RAM in a form that can be passed as boot
2878 argument to Linux, for instance like that:
2880 setenv bootargs ... mem=\${mem}
2883 This way you can tell Linux not to use this memory,
2884 either, which results in a memory region that will
2885 not be affected by reboots.
2887 *WARNING* If your board configuration uses automatic
2888 detection of the RAM size, you must make sure that
2889 this memory test is non-destructive. So far, the
2890 following board configurations are known to be
2893 IVMS8, IVML24, SPD8xx, TQM8xxL,
2894 HERMES, IP860, RPXlite, LWMON,
2897 - Access to physical memory region (> 4GB)
2898 Some basic support is provided for operations on memory not
2899 normally accessible to U-Boot - e.g. some architectures
2900 support access to more than 4GB of memory on 32-bit
2901 machines using physical address extension or similar.
2902 Define CONFIG_PHYSMEM to access this basic support, which
2903 currently only supports clearing the memory.
2908 Define this variable to stop the system in case of a
2909 fatal error, so that you have to reset it manually.
2910 This is probably NOT a good idea for an embedded
2911 system where you want the system to reboot
2912 automatically as fast as possible, but it may be
2913 useful during development since you can try to debug
2914 the conditions that lead to the situation.
2916 CONFIG_NET_RETRY_COUNT
2918 This variable defines the number of retries for
2919 network operations like ARP, RARP, TFTP, or BOOTP
2920 before giving up the operation. If not defined, a
2921 default value of 5 is used.
2925 Timeout waiting for an ARP reply in milliseconds.
2929 Timeout in milliseconds used in NFS protocol.
2930 If you encounter "ERROR: Cannot umount" in nfs command,
2931 try longer timeout such as
2932 #define CONFIG_NFS_TIMEOUT 10000UL
2934 - Command Interpreter:
2935 CONFIG_AUTO_COMPLETE
2937 Enable auto completion of commands using TAB.
2939 CONFIG_SYS_PROMPT_HUSH_PS2
2941 This defines the secondary prompt string, which is
2942 printed when the command interpreter needs more input
2943 to complete a command. Usually "> ".
2947 In the current implementation, the local variables
2948 space and global environment variables space are
2949 separated. Local variables are those you define by
2950 simply typing `name=value'. To access a local
2951 variable later on, you have write `$name' or
2952 `${name}'; to execute the contents of a variable
2953 directly type `$name' at the command prompt.
2955 Global environment variables are those you use
2956 setenv/printenv to work with. To run a command stored
2957 in such a variable, you need to use the run command,
2958 and you must not use the '$' sign to access them.
2960 To store commands and special characters in a
2961 variable, please use double quotation marks
2962 surrounding the whole text of the variable, instead
2963 of the backslashes before semicolons and special
2966 - Command Line Editing and History:
2967 CONFIG_CMDLINE_EDITING
2969 Enable editing and History functions for interactive
2970 command line input operations
2972 - Default Environment:
2973 CONFIG_EXTRA_ENV_SETTINGS
2975 Define this to contain any number of null terminated
2976 strings (variable = value pairs) that will be part of
2977 the default environment compiled into the boot image.
2979 For example, place something like this in your
2980 board's config file:
2982 #define CONFIG_EXTRA_ENV_SETTINGS \
2986 Warning: This method is based on knowledge about the
2987 internal format how the environment is stored by the
2988 U-Boot code. This is NOT an official, exported
2989 interface! Although it is unlikely that this format
2990 will change soon, there is no guarantee either.
2991 You better know what you are doing here.
2993 Note: overly (ab)use of the default environment is
2994 discouraged. Make sure to check other ways to preset
2995 the environment like the "source" command or the
2998 CONFIG_ENV_VARS_UBOOT_CONFIG
3000 Define this in order to add variables describing the
3001 U-Boot build configuration to the default environment.
3002 These will be named arch, cpu, board, vendor, and soc.
3004 Enabling this option will cause the following to be defined:
3012 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3014 Define this in order to add variables describing certain
3015 run-time determined information about the hardware to the
3016 environment. These will be named board_name, board_rev.
3018 CONFIG_DELAY_ENVIRONMENT
3020 Normally the environment is loaded when the board is
3021 initialised so that it is available to U-Boot. This inhibits
3022 that so that the environment is not available until
3023 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3024 this is instead controlled by the value of
3025 /config/load-environment.
3027 - Parallel Flash support:
3030 Traditionally U-boot was run on systems with parallel NOR
3031 flash. This option is used to disable support for parallel NOR
3032 flash. This option should be defined if the board does not have
3035 If this option is not defined one of the generic flash drivers
3036 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3037 selected or the board must provide an implementation of the
3038 flash API (see include/flash.h).
3040 - DataFlash Support:
3041 CONFIG_HAS_DATAFLASH
3043 Defining this option enables DataFlash features and
3044 allows to read/write in Dataflash via the standard
3047 - Serial Flash support
3050 Defining this option enables SPI flash commands
3051 'sf probe/read/write/erase/update'.
3053 Usage requires an initial 'probe' to define the serial
3054 flash parameters, followed by read/write/erase/update
3057 The following defaults may be provided by the platform
3058 to handle the common case when only a single serial
3059 flash is present on the system.
3061 CONFIG_SF_DEFAULT_BUS Bus identifier
3062 CONFIG_SF_DEFAULT_CS Chip-select
3063 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3064 CONFIG_SF_DEFAULT_SPEED in Hz
3068 Define this option to include a destructive SPI flash
3071 CONFIG_SF_DUAL_FLASH Dual flash memories
3073 Define this option to use dual flash support where two flash
3074 memories can be connected with a given cs line.
3075 Currently Xilinx Zynq qspi supports these type of connections.
3077 - SystemACE Support:
3080 Adding this option adds support for Xilinx SystemACE
3081 chips attached via some sort of local bus. The address
3082 of the chip must also be defined in the
3083 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3085 #define CONFIG_SYSTEMACE
3086 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3088 When SystemACE support is added, the "ace" device type
3089 becomes available to the fat commands, i.e. fatls.
3091 - TFTP Fixed UDP Port:
3094 If this is defined, the environment variable tftpsrcp
3095 is used to supply the TFTP UDP source port value.
3096 If tftpsrcp isn't defined, the normal pseudo-random port
3097 number generator is used.
3099 Also, the environment variable tftpdstp is used to supply
3100 the TFTP UDP destination port value. If tftpdstp isn't
3101 defined, the normal port 69 is used.
3103 The purpose for tftpsrcp is to allow a TFTP server to
3104 blindly start the TFTP transfer using the pre-configured
3105 target IP address and UDP port. This has the effect of
3106 "punching through" the (Windows XP) firewall, allowing
3107 the remainder of the TFTP transfer to proceed normally.
3108 A better solution is to properly configure the firewall,
3109 but sometimes that is not allowed.
3114 This enables a generic 'hash' command which can produce
3115 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3119 Enable the hash verify command (hash -v). This adds to code
3122 CONFIG_SHA1 - This option enables support of hashing using SHA1
3123 algorithm. The hash is calculated in software.
3124 CONFIG_SHA256 - This option enables support of hashing using
3125 SHA256 algorithm. The hash is calculated in software.
3126 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3127 for SHA1/SHA256 hashing.
3128 This affects the 'hash' command and also the
3129 hash_lookup_algo() function.
3130 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3131 hardware-acceleration for SHA1/SHA256 progressive hashing.
3132 Data can be streamed in a block at a time and the hashing
3133 is performed in hardware.
3135 Note: There is also a sha1sum command, which should perhaps
3136 be deprecated in favour of 'hash sha1'.
3138 - Freescale i.MX specific commands:
3139 CONFIG_CMD_HDMIDETECT
3140 This enables 'hdmidet' command which returns true if an
3141 HDMI monitor is detected. This command is i.MX 6 specific.
3144 This enables the 'bmode' (bootmode) command for forcing
3145 a boot from specific media.
3147 This is useful for forcing the ROM's usb downloader to
3148 activate upon a watchdog reset which is nice when iterating
3149 on U-Boot. Using the reset button or running bmode normal
3150 will set it back to normal. This command currently
3151 supports i.MX53 and i.MX6.
3156 This enables the RSA algorithm used for FIT image verification
3157 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3159 The Modular Exponentiation algorithm in RSA is implemented using
3160 driver model. So CONFIG_DM needs to be enabled by default for this
3161 library to function.
3163 The signing part is build into mkimage regardless of this
3164 option. The software based modular exponentiation is built into
3165 mkimage irrespective of this option.
3167 - bootcount support:
3168 CONFIG_BOOTCOUNT_LIMIT
3170 This enables the bootcounter support, see:
3171 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3174 enable special bootcounter support on at91sam9xe based boards.
3176 enable special bootcounter support on blackfin based boards.
3178 enable special bootcounter support on da850 based boards.
3179 CONFIG_BOOTCOUNT_RAM
3180 enable support for the bootcounter in RAM
3181 CONFIG_BOOTCOUNT_I2C
3182 enable support for the bootcounter on an i2c (like RTC) device.
3183 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3184 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3186 CONFIG_BOOTCOUNT_ALEN = address len
3188 - Show boot progress:
3189 CONFIG_SHOW_BOOT_PROGRESS
3191 Defining this option allows to add some board-
3192 specific code (calling a user-provided function
3193 "show_boot_progress(int)") that enables you to show
3194 the system's boot progress on some display (for
3195 example, some LED's) on your board. At the moment,
3196 the following checkpoints are implemented:
3199 Legacy uImage format:
3202 1 common/cmd_bootm.c before attempting to boot an image
3203 -1 common/cmd_bootm.c Image header has bad magic number
3204 2 common/cmd_bootm.c Image header has correct magic number
3205 -2 common/cmd_bootm.c Image header has bad checksum
3206 3 common/cmd_bootm.c Image header has correct checksum
3207 -3 common/cmd_bootm.c Image data has bad checksum
3208 4 common/cmd_bootm.c Image data has correct checksum
3209 -4 common/cmd_bootm.c Image is for unsupported architecture
3210 5 common/cmd_bootm.c Architecture check OK
3211 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3212 6 common/cmd_bootm.c Image Type check OK
3213 -6 common/cmd_bootm.c gunzip uncompression error
3214 -7 common/cmd_bootm.c Unimplemented compression type
3215 7 common/cmd_bootm.c Uncompression OK
3216 8 common/cmd_bootm.c No uncompress/copy overwrite error
3217 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3219 9 common/image.c Start initial ramdisk verification
3220 -10 common/image.c Ramdisk header has bad magic number
3221 -11 common/image.c Ramdisk header has bad checksum
3222 10 common/image.c Ramdisk header is OK
3223 -12 common/image.c Ramdisk data has bad checksum
3224 11 common/image.c Ramdisk data has correct checksum
3225 12 common/image.c Ramdisk verification complete, start loading
3226 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3227 13 common/image.c Start multifile image verification
3228 14 common/image.c No initial ramdisk, no multifile, continue.
3230 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3232 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3233 -31 post/post.c POST test failed, detected by post_output_backlog()
3234 -32 post/post.c POST test failed, detected by post_run_single()
3236 34 common/cmd_doc.c before loading a Image from a DOC device
3237 -35 common/cmd_doc.c Bad usage of "doc" command
3238 35 common/cmd_doc.c correct usage of "doc" command
3239 -36 common/cmd_doc.c No boot device
3240 36 common/cmd_doc.c correct boot device
3241 -37 common/cmd_doc.c Unknown Chip ID on boot device
3242 37 common/cmd_doc.c correct chip ID found, device available
3243 -38 common/cmd_doc.c Read Error on boot device
3244 38 common/cmd_doc.c reading Image header from DOC device OK
3245 -39 common/cmd_doc.c Image header has bad magic number
3246 39 common/cmd_doc.c Image header has correct magic number
3247 -40 common/cmd_doc.c Error reading Image from DOC device
3248 40 common/cmd_doc.c Image header has correct magic number
3249 41 common/cmd_ide.c before loading a Image from a IDE device
3250 -42 common/cmd_ide.c Bad usage of "ide" command
3251 42 common/cmd_ide.c correct usage of "ide" command
3252 -43 common/cmd_ide.c No boot device
3253 43 common/cmd_ide.c boot device found
3254 -44 common/cmd_ide.c Device not available
3255 44 common/cmd_ide.c Device available
3256 -45 common/cmd_ide.c wrong partition selected
3257 45 common/cmd_ide.c partition selected
3258 -46 common/cmd_ide.c Unknown partition table
3259 46 common/cmd_ide.c valid partition table found
3260 -47 common/cmd_ide.c Invalid partition type
3261 47 common/cmd_ide.c correct partition type
3262 -48 common/cmd_ide.c Error reading Image Header on boot device
3263 48 common/cmd_ide.c reading Image Header from IDE device OK
3264 -49 common/cmd_ide.c Image header has bad magic number
3265 49 common/cmd_ide.c Image header has correct magic number
3266 -50 common/cmd_ide.c Image header has bad checksum
3267 50 common/cmd_ide.c Image header has correct checksum
3268 -51 common/cmd_ide.c Error reading Image from IDE device
3269 51 common/cmd_ide.c reading Image from IDE device OK
3270 52 common/cmd_nand.c before loading a Image from a NAND device
3271 -53 common/cmd_nand.c Bad usage of "nand" command
3272 53 common/cmd_nand.c correct usage of "nand" command
3273 -54 common/cmd_nand.c No boot device
3274 54 common/cmd_nand.c boot device found
3275 -55 common/cmd_nand.c Unknown Chip ID on boot device
3276 55 common/cmd_nand.c correct chip ID found, device available
3277 -56 common/cmd_nand.c Error reading Image Header on boot device
3278 56 common/cmd_nand.c reading Image Header from NAND device OK
3279 -57 common/cmd_nand.c Image header has bad magic number
3280 57 common/cmd_nand.c Image header has correct magic number
3281 -58 common/cmd_nand.c Error reading Image from NAND device
3282 58 common/cmd_nand.c reading Image from NAND device OK
3284 -60 common/env_common.c Environment has a bad CRC, using default
3286 64 net/eth.c starting with Ethernet configuration.
3287 -64 net/eth.c no Ethernet found.
3288 65 net/eth.c Ethernet found.
3290 -80 common/cmd_net.c usage wrong
3291 80 common/cmd_net.c before calling net_loop()
3292 -81 common/cmd_net.c some error in net_loop() occurred
3293 81 common/cmd_net.c net_loop() back without error
3294 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3295 82 common/cmd_net.c trying automatic boot
3296 83 common/cmd_net.c running "source" command
3297 -83 common/cmd_net.c some error in automatic boot or "source" command
3298 84 common/cmd_net.c end without errors
3303 100 common/cmd_bootm.c Kernel FIT Image has correct format
3304 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3305 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3306 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3307 102 common/cmd_bootm.c Kernel unit name specified
3308 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3309 103 common/cmd_bootm.c Found configuration node
3310 104 common/cmd_bootm.c Got kernel subimage node offset
3311 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3312 105 common/cmd_bootm.c Kernel subimage hash verification OK
3313 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3314 106 common/cmd_bootm.c Architecture check OK
3315 -106 common/cmd_bootm.c Kernel subimage has wrong type
3316 107 common/cmd_bootm.c Kernel subimage type OK
3317 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3318 108 common/cmd_bootm.c Got kernel subimage data/size
3319 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3320 -109 common/cmd_bootm.c Can't get kernel subimage type
3321 -110 common/cmd_bootm.c Can't get kernel subimage comp
3322 -111 common/cmd_bootm.c Can't get kernel subimage os
3323 -112 common/cmd_bootm.c Can't get kernel subimage load address
3324 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3326 120 common/image.c Start initial ramdisk verification
3327 -120 common/image.c Ramdisk FIT image has incorrect format
3328 121 common/image.c Ramdisk FIT image has correct format
3329 122 common/image.c No ramdisk subimage unit name, using configuration
3330 -122 common/image.c Can't get configuration for ramdisk subimage
3331 123 common/image.c Ramdisk unit name specified
3332 -124 common/image.c Can't get ramdisk subimage node offset
3333 125 common/image.c Got ramdisk subimage node offset
3334 -125 common/image.c Ramdisk subimage hash verification failed
3335 126 common/image.c Ramdisk subimage hash verification OK
3336 -126 common/image.c Ramdisk subimage for unsupported architecture
3337 127 common/image.c Architecture check OK
3338 -127 common/image.c Can't get ramdisk subimage data/size
3339 128 common/image.c Got ramdisk subimage data/size
3340 129 common/image.c Can't get ramdisk load address
3341 -129 common/image.c Got ramdisk load address
3343 -130 common/cmd_doc.c Incorrect FIT image format
3344 131 common/cmd_doc.c FIT image format OK
3346 -140 common/cmd_ide.c Incorrect FIT image format
3347 141 common/cmd_ide.c FIT image format OK
3349 -150 common/cmd_nand.c Incorrect FIT image format
3350 151 common/cmd_nand.c FIT image format OK
3352 - legacy image format:
3353 CONFIG_IMAGE_FORMAT_LEGACY
3354 enables the legacy image format support in U-Boot.
3357 enabled if CONFIG_FIT_SIGNATURE is not defined.
3359 CONFIG_DISABLE_IMAGE_LEGACY
3360 disable the legacy image format
3362 This define is introduced, as the legacy image format is
3363 enabled per default for backward compatibility.
3365 - FIT image support:
3367 Enable support for the FIT uImage format.
3369 CONFIG_FIT_BEST_MATCH
3370 When no configuration is explicitly selected, default to the
3371 one whose fdt's compatibility field best matches that of
3372 U-Boot itself. A match is considered "best" if it matches the
3373 most specific compatibility entry of U-Boot's fdt's root node.
3374 The order of entries in the configuration's fdt is ignored.
3376 CONFIG_FIT_SIGNATURE
3377 This option enables signature verification of FIT uImages,
3378 using a hash signed and verified using RSA. If
3379 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3380 hashing is available using hardware, RSA library will use it.
3381 See doc/uImage.FIT/signature.txt for more details.
3383 WARNING: When relying on signed FIT images with required
3384 signature check the legacy image format is default
3385 disabled. If a board need legacy image format support
3386 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3388 CONFIG_FIT_DISABLE_SHA256
3389 Supporting SHA256 hashes has quite an impact on binary size.
3390 For constrained systems sha256 hash support can be disabled
3393 - Standalone program support:
3394 CONFIG_STANDALONE_LOAD_ADDR
3396 This option defines a board specific value for the
3397 address where standalone program gets loaded, thus
3398 overwriting the architecture dependent default
3401 - Frame Buffer Address:
3404 Define CONFIG_FB_ADDR if you want to use specific
3405 address for frame buffer. This is typically the case
3406 when using a graphics controller has separate video
3407 memory. U-Boot will then place the frame buffer at
3408 the given address instead of dynamically reserving it
3409 in system RAM by calling lcd_setmem(), which grabs
3410 the memory for the frame buffer depending on the
3411 configured panel size.
3413 Please see board_init_f function.
3415 - Automatic software updates via TFTP server
3417 CONFIG_UPDATE_TFTP_CNT_MAX
3418 CONFIG_UPDATE_TFTP_MSEC_MAX
3420 These options enable and control the auto-update feature;
3421 for a more detailed description refer to doc/README.update.
3423 - MTD Support (mtdparts command, UBI support)
3426 Adds the MTD device infrastructure from the Linux kernel.
3427 Needed for mtdparts command support.
3429 CONFIG_MTD_PARTITIONS
3431 Adds the MTD partitioning infrastructure from the Linux
3432 kernel. Needed for UBI support.
3437 Adds commands for interacting with MTD partitions formatted
3438 with the UBI flash translation layer
3440 Requires also defining CONFIG_RBTREE
3442 CONFIG_UBI_SILENCE_MSG
3444 Make the verbose messages from UBI stop printing. This leaves
3445 warnings and errors enabled.
3448 CONFIG_MTD_UBI_WL_THRESHOLD
3449 This parameter defines the maximum difference between the highest
3450 erase counter value and the lowest erase counter value of eraseblocks
3451 of UBI devices. When this threshold is exceeded, UBI starts performing
3452 wear leveling by means of moving data from eraseblock with low erase
3453 counter to eraseblocks with high erase counter.
3455 The default value should be OK for SLC NAND flashes, NOR flashes and
3456 other flashes which have eraseblock life-cycle 100000 or more.
3457 However, in case of MLC NAND flashes which typically have eraseblock
3458 life-cycle less than 10000, the threshold should be lessened (e.g.,
3459 to 128 or 256, although it does not have to be power of 2).
3463 CONFIG_MTD_UBI_BEB_LIMIT
3464 This option specifies the maximum bad physical eraseblocks UBI
3465 expects on the MTD device (per 1024 eraseblocks). If the
3466 underlying flash does not admit of bad eraseblocks (e.g. NOR
3467 flash), this value is ignored.
3469 NAND datasheets often specify the minimum and maximum NVM
3470 (Number of Valid Blocks) for the flashes' endurance lifetime.
3471 The maximum expected bad eraseblocks per 1024 eraseblocks
3472 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3473 which gives 20 for most NANDs (MaxNVB is basically the total
3474 count of eraseblocks on the chip).
3476 To put it differently, if this value is 20, UBI will try to
3477 reserve about 1.9% of physical eraseblocks for bad blocks
3478 handling. And that will be 1.9% of eraseblocks on the entire
3479 NAND chip, not just the MTD partition UBI attaches. This means
3480 that if you have, say, a NAND flash chip admits maximum 40 bad
3481 eraseblocks, and it is split on two MTD partitions of the same
3482 size, UBI will reserve 40 eraseblocks when attaching a
3487 CONFIG_MTD_UBI_FASTMAP
3488 Fastmap is a mechanism which allows attaching an UBI device
3489 in nearly constant time. Instead of scanning the whole MTD device it
3490 only has to locate a checkpoint (called fastmap) on the device.
3491 The on-flash fastmap contains all information needed to attach
3492 the device. Using fastmap makes only sense on large devices where
3493 attaching by scanning takes long. UBI will not automatically install
3494 a fastmap on old images, but you can set the UBI parameter
3495 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3496 that fastmap-enabled images are still usable with UBI implementations
3497 without fastmap support. On typical flash devices the whole fastmap
3498 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3500 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3501 Set this parameter to enable fastmap automatically on images
3508 Adds commands for interacting with UBI volumes formatted as
3509 UBIFS. UBIFS is read-only in u-boot.
3511 Requires UBI support as well as CONFIG_LZO
3513 CONFIG_UBIFS_SILENCE_MSG
3515 Make the verbose messages from UBIFS stop printing. This leaves
3516 warnings and errors enabled.
3520 Enable building of SPL globally.
3523 LDSCRIPT for linking the SPL binary.
3525 CONFIG_SPL_MAX_FOOTPRINT
3526 Maximum size in memory allocated to the SPL, BSS included.
3527 When defined, the linker checks that the actual memory
3528 used by SPL from _start to __bss_end does not exceed it.
3529 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3530 must not be both defined at the same time.
3533 Maximum size of the SPL image (text, data, rodata, and
3534 linker lists sections), BSS excluded.
3535 When defined, the linker checks that the actual size does
3538 CONFIG_SPL_TEXT_BASE
3539 TEXT_BASE for linking the SPL binary.
3541 CONFIG_SPL_RELOC_TEXT_BASE
3542 Address to relocate to. If unspecified, this is equal to
3543 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3545 CONFIG_SPL_BSS_START_ADDR
3546 Link address for the BSS within the SPL binary.
3548 CONFIG_SPL_BSS_MAX_SIZE
3549 Maximum size in memory allocated to the SPL BSS.
3550 When defined, the linker checks that the actual memory used
3551 by SPL from __bss_start to __bss_end does not exceed it.
3552 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3553 must not be both defined at the same time.
3556 Adress of the start of the stack SPL will use
3558 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3559 When defined, SPL will panic() if the image it has
3560 loaded does not have a signature.
3561 Defining this is useful when code which loads images
3562 in SPL cannot guarantee that absolutely all read errors
3564 An example is the LPC32XX MLC NAND driver, which will
3565 consider that a completely unreadable NAND block is bad,
3566 and thus should be skipped silently.
3568 CONFIG_SPL_RELOC_STACK
3569 Adress of the start of the stack SPL will use after
3570 relocation. If unspecified, this is equal to
3573 CONFIG_SYS_SPL_MALLOC_START
3574 Starting address of the malloc pool used in SPL.
3576 CONFIG_SYS_SPL_MALLOC_SIZE
3577 The size of the malloc pool used in SPL.
3579 CONFIG_SPL_FRAMEWORK
3580 Enable the SPL framework under common/. This framework
3581 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3582 NAND loading of the Linux Kernel.
3585 Enable booting directly to an OS from SPL.
3586 See also: doc/README.falcon
3588 CONFIG_SPL_DISPLAY_PRINT
3589 For ARM, enable an optional function to print more information
3590 about the running system.
3592 CONFIG_SPL_INIT_MINIMAL
3593 Arch init code should be built for a very small image
3595 CONFIG_SPL_LIBCOMMON_SUPPORT
3596 Support for common/libcommon.o in SPL binary
3598 CONFIG_SPL_LIBDISK_SUPPORT
3599 Support for disk/libdisk.o in SPL binary
3601 CONFIG_SPL_I2C_SUPPORT
3602 Support for drivers/i2c/libi2c.o in SPL binary
3604 CONFIG_SPL_GPIO_SUPPORT
3605 Support for drivers/gpio/libgpio.o in SPL binary
3607 CONFIG_SPL_MMC_SUPPORT
3608 Support for drivers/mmc/libmmc.o in SPL binary
3610 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3611 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3612 Address and partition on the MMC to load U-Boot from
3613 when the MMC is being used in raw mode.
3615 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3616 Partition on the MMC to load U-Boot from when the MMC is being
3619 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3620 Sector to load kernel uImage from when MMC is being
3621 used in raw mode (for Falcon mode)
3623 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3624 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3625 Sector and number of sectors to load kernel argument
3626 parameters from when MMC is being used in raw mode
3629 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3630 Partition on the MMC to load U-Boot from when the MMC is being
3633 CONFIG_SPL_FAT_SUPPORT
3634 Support for fs/fat/libfat.o in SPL binary
3636 CONFIG_SPL_EXT_SUPPORT
3637 Support for EXT filesystem in SPL binary
3639 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3640 Filename to read to load U-Boot when reading from filesystem
3642 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3643 Filename to read to load kernel uImage when reading
3644 from filesystem (for Falcon mode)
3646 CONFIG_SPL_FS_LOAD_ARGS_NAME
3647 Filename to read to load kernel argument parameters
3648 when reading from filesystem (for Falcon mode)
3650 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3651 Set this for NAND SPL on PPC mpc83xx targets, so that
3652 start.S waits for the rest of the SPL to load before
3653 continuing (the hardware starts execution after just
3654 loading the first page rather than the full 4K).
3656 CONFIG_SPL_SKIP_RELOCATE
3657 Avoid SPL relocation
3659 CONFIG_SPL_NAND_BASE
3660 Include nand_base.c in the SPL. Requires
3661 CONFIG_SPL_NAND_DRIVERS.
3663 CONFIG_SPL_NAND_DRIVERS
3664 SPL uses normal NAND drivers, not minimal drivers.
3667 Include standard software ECC in the SPL
3669 CONFIG_SPL_NAND_SIMPLE
3670 Support for NAND boot using simple NAND drivers that
3671 expose the cmd_ctrl() interface.
3673 CONFIG_SPL_MTD_SUPPORT
3674 Support for the MTD subsystem within SPL. Useful for
3675 environment on NAND support within SPL.
3677 CONFIG_SPL_NAND_RAW_ONLY
3678 Support to boot only raw u-boot.bin images. Use this only
3679 if you need to save space.
3681 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3682 Set for the SPL on PPC mpc8xxx targets, support for
3683 drivers/ddr/fsl/libddr.o in SPL binary.
3685 CONFIG_SPL_COMMON_INIT_DDR
3686 Set for common ddr init with serial presence detect in
3689 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3690 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3691 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3692 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3693 CONFIG_SYS_NAND_ECCBYTES
3694 Defines the size and behavior of the NAND that SPL uses
3697 CONFIG_SPL_NAND_BOOT
3698 Add support NAND boot
3700 CONFIG_SYS_NAND_U_BOOT_OFFS
3701 Location in NAND to read U-Boot from
3703 CONFIG_SYS_NAND_U_BOOT_DST
3704 Location in memory to load U-Boot to
3706 CONFIG_SYS_NAND_U_BOOT_SIZE
3707 Size of image to load
3709 CONFIG_SYS_NAND_U_BOOT_START
3710 Entry point in loaded image to jump to
3712 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3713 Define this if you need to first read the OOB and then the
3714 data. This is used, for example, on davinci platforms.
3716 CONFIG_SPL_OMAP3_ID_NAND
3717 Support for an OMAP3-specific set of functions to return the
3718 ID and MFR of the first attached NAND chip, if present.
3720 CONFIG_SPL_SERIAL_SUPPORT
3721 Support for drivers/serial/libserial.o in SPL binary
3723 CONFIG_SPL_SPI_FLASH_SUPPORT
3724 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3726 CONFIG_SPL_SPI_SUPPORT
3727 Support for drivers/spi/libspi.o in SPL binary
3729 CONFIG_SPL_RAM_DEVICE
3730 Support for running image already present in ram, in SPL binary
3732 CONFIG_SPL_LIBGENERIC_SUPPORT
3733 Support for lib/libgeneric.o in SPL binary
3735 CONFIG_SPL_ENV_SUPPORT
3736 Support for the environment operating in SPL binary
3738 CONFIG_SPL_NET_SUPPORT
3739 Support for the net/libnet.o in SPL binary.
3740 It conflicts with SPL env from storage medium specified by
3741 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3744 Image offset to which the SPL should be padded before appending
3745 the SPL payload. By default, this is defined as
3746 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3747 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3748 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3751 Final target image containing SPL and payload. Some SPLs
3752 use an arch-specific makefile fragment instead, for
3753 example if more than one image needs to be produced.
3755 CONFIG_FIT_SPL_PRINT
3756 Printing information about a FIT image adds quite a bit of
3757 code to SPL. So this is normally disabled in SPL. Use this
3758 option to re-enable it. This will affect the output of the
3759 bootm command when booting a FIT image.
3763 Enable building of TPL globally.
3766 Image offset to which the TPL should be padded before appending
3767 the TPL payload. By default, this is defined as
3768 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3769 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3770 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3775 [so far only for SMDK2400 boards]
3777 - Modem support enable:
3778 CONFIG_MODEM_SUPPORT
3780 - RTS/CTS Flow control enable:
3783 - Modem debug support:
3784 CONFIG_MODEM_SUPPORT_DEBUG
3786 Enables debugging stuff (char screen[1024], dbg())
3787 for modem support. Useful only with BDI2000.
3789 - Interrupt support (PPC):
3791 There are common interrupt_init() and timer_interrupt()
3792 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3793 for CPU specific initialization. interrupt_init_cpu()
3794 should set decrementer_count to appropriate value. If
3795 CPU resets decrementer automatically after interrupt
3796 (ppc4xx) it should set decrementer_count to zero.
3797 timer_interrupt() calls timer_interrupt_cpu() for CPU
3798 specific handling. If board has watchdog / status_led
3799 / other_activity_monitor it works automatically from
3800 general timer_interrupt().
3804 In the target system modem support is enabled when a
3805 specific key (key combination) is pressed during
3806 power-on. Otherwise U-Boot will boot normally
3807 (autoboot). The key_pressed() function is called from
3808 board_init(). Currently key_pressed() is a dummy
3809 function, returning 1 and thus enabling modem
3812 If there are no modem init strings in the
3813 environment, U-Boot proceed to autoboot; the
3814 previous output (banner, info printfs) will be
3817 See also: doc/README.Modem
3819 Board initialization settings:
3820 ------------------------------
3822 During Initialization u-boot calls a number of board specific functions
3823 to allow the preparation of board specific prerequisites, e.g. pin setup
3824 before drivers are initialized. To enable these callbacks the
3825 following configuration macros have to be defined. Currently this is
3826 architecture specific, so please check arch/your_architecture/lib/board.c
3827 typically in board_init_f() and board_init_r().
3829 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3830 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3831 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3832 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3834 Configuration Settings:
3835 -----------------------
3837 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3838 Optionally it can be defined to support 64-bit memory commands.
3840 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3841 undefine this when you're short of memory.
3843 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3844 width of the commands listed in the 'help' command output.
3846 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3847 prompt for user input.
3849 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3851 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3853 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3855 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3856 the application (usually a Linux kernel) when it is
3859 - CONFIG_SYS_BAUDRATE_TABLE:
3860 List of legal baudrate settings for this board.
3862 - CONFIG_SYS_CONSOLE_INFO_QUIET
3863 Suppress display of console information at boot.
3865 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3866 If the board specific function
3867 extern int overwrite_console (void);
3868 returns 1, the stdin, stderr and stdout are switched to the
3869 serial port, else the settings in the environment are used.
3871 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3872 Enable the call to overwrite_console().
3874 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3875 Enable overwrite of previous console environment settings.
3877 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3878 Begin and End addresses of the area used by the
3881 - CONFIG_SYS_ALT_MEMTEST:
3882 Enable an alternate, more extensive memory test.
3884 - CONFIG_SYS_MEMTEST_SCRATCH:
3885 Scratch address used by the alternate memory test
3886 You only need to set this if address zero isn't writeable
3888 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3889 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3890 this specified memory area will get subtracted from the top
3891 (end) of RAM and won't get "touched" at all by U-Boot. By
3892 fixing up gd->ram_size the Linux kernel should gets passed
3893 the now "corrected" memory size and won't touch it either.
3894 This should work for arch/ppc and arch/powerpc. Only Linux
3895 board ports in arch/powerpc with bootwrapper support that
3896 recalculate the memory size from the SDRAM controller setup
3897 will have to get fixed in Linux additionally.
3899 This option can be used as a workaround for the 440EPx/GRx
3900 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3903 WARNING: Please make sure that this value is a multiple of
3904 the Linux page size (normally 4k). If this is not the case,
3905 then the end address of the Linux memory will be located at a
3906 non page size aligned address and this could cause major
3909 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3910 Enable temporary baudrate change while serial download
3912 - CONFIG_SYS_SDRAM_BASE:
3913 Physical start address of SDRAM. _Must_ be 0 here.
3915 - CONFIG_SYS_MBIO_BASE:
3916 Physical start address of Motherboard I/O (if using a
3919 - CONFIG_SYS_FLASH_BASE:
3920 Physical start address of Flash memory.
3922 - CONFIG_SYS_MONITOR_BASE:
3923 Physical start address of boot monitor code (set by
3924 make config files to be same as the text base address
3925 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3926 CONFIG_SYS_FLASH_BASE when booting from flash.
3928 - CONFIG_SYS_MONITOR_LEN:
3929 Size of memory reserved for monitor code, used to
3930 determine _at_compile_time_ (!) if the environment is
3931 embedded within the U-Boot image, or in a separate
3934 - CONFIG_SYS_MALLOC_LEN:
3935 Size of DRAM reserved for malloc() use.
3937 - CONFIG_SYS_MALLOC_F_LEN
3938 Size of the malloc() pool for use before relocation. If
3939 this is defined, then a very simple malloc() implementation
3940 will become available before relocation. The address is just
3941 below the global data, and the stack is moved down to make
3944 This feature allocates regions with increasing addresses
3945 within the region. calloc() is supported, but realloc()
3946 is not available. free() is supported but does nothing.
3947 The memory will be freed (or in fact just forgotten) when
3948 U-Boot relocates itself.
3950 Pre-relocation malloc() is only supported on ARM and sandbox
3951 at present but is fairly easy to enable for other archs.
3953 - CONFIG_SYS_MALLOC_SIMPLE
3954 Provides a simple and small malloc() and calloc() for those
3955 boards which do not use the full malloc in SPL (which is
3956 enabled with CONFIG_SYS_SPL_MALLOC_START).
3958 - CONFIG_SYS_NONCACHED_MEMORY:
3959 Size of non-cached memory area. This area of memory will be
3960 typically located right below the malloc() area and mapped
3961 uncached in the MMU. This is useful for drivers that would
3962 otherwise require a lot of explicit cache maintenance. For
3963 some drivers it's also impossible to properly maintain the
3964 cache. For example if the regions that need to be flushed
3965 are not a multiple of the cache-line size, *and* padding
3966 cannot be allocated between the regions to align them (i.e.
3967 if the HW requires a contiguous array of regions, and the
3968 size of each region is not cache-aligned), then a flush of
3969 one region may result in overwriting data that hardware has
3970 written to another region in the same cache-line. This can
3971 happen for example in network drivers where descriptors for
3972 buffers are typically smaller than the CPU cache-line (e.g.
3973 16 bytes vs. 32 or 64 bytes).
3975 Non-cached memory is only supported on 32-bit ARM at present.
3977 - CONFIG_SYS_BOOTM_LEN:
3978 Normally compressed uImages are limited to an
3979 uncompressed size of 8 MBytes. If this is not enough,
3980 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3981 to adjust this setting to your needs.
3983 - CONFIG_SYS_BOOTMAPSZ:
3984 Maximum size of memory mapped by the startup code of
3985 the Linux kernel; all data that must be processed by
3986 the Linux kernel (bd_info, boot arguments, FDT blob if
3987 used) must be put below this limit, unless "bootm_low"
3988 environment variable is defined and non-zero. In such case
3989 all data for the Linux kernel must be between "bootm_low"
3990 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3991 variable "bootm_mapsize" will override the value of
3992 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3993 then the value in "bootm_size" will be used instead.
3995 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3996 Enable initrd_high functionality. If defined then the
3997 initrd_high feature is enabled and the bootm ramdisk subcommand
4000 - CONFIG_SYS_BOOT_GET_CMDLINE:
4001 Enables allocating and saving kernel cmdline in space between
4002 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4004 - CONFIG_SYS_BOOT_GET_KBD:
4005 Enables allocating and saving a kernel copy of the bd_info in
4006 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4008 - CONFIG_SYS_MAX_FLASH_BANKS:
4009 Max number of Flash memory banks
4011 - CONFIG_SYS_MAX_FLASH_SECT:
4012 Max number of sectors on a Flash chip
4014 - CONFIG_SYS_FLASH_ERASE_TOUT:
4015 Timeout for Flash erase operations (in ms)
4017 - CONFIG_SYS_FLASH_WRITE_TOUT:
4018 Timeout for Flash write operations (in ms)
4020 - CONFIG_SYS_FLASH_LOCK_TOUT
4021 Timeout for Flash set sector lock bit operation (in ms)
4023 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4024 Timeout for Flash clear lock bits operation (in ms)
4026 - CONFIG_SYS_FLASH_PROTECTION
4027 If defined, hardware flash sectors protection is used
4028 instead of U-Boot software protection.
4030 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4032 Enable TFTP transfers directly to flash memory;
4033 without this option such a download has to be
4034 performed in two steps: (1) download to RAM, and (2)
4035 copy from RAM to flash.
4037 The two-step approach is usually more reliable, since
4038 you can check if the download worked before you erase
4039 the flash, but in some situations (when system RAM is
4040 too limited to allow for a temporary copy of the
4041 downloaded image) this option may be very useful.
4043 - CONFIG_SYS_FLASH_CFI:
4044 Define if the flash driver uses extra elements in the
4045 common flash structure for storing flash geometry.
4047 - CONFIG_FLASH_CFI_DRIVER
4048 This option also enables the building of the cfi_flash driver
4049 in the drivers directory
4051 - CONFIG_FLASH_CFI_MTD
4052 This option enables the building of the cfi_mtd driver
4053 in the drivers directory. The driver exports CFI flash
4056 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4057 Use buffered writes to flash.
4059 - CONFIG_FLASH_SPANSION_S29WS_N
4060 s29ws-n MirrorBit flash has non-standard addresses for buffered
4063 - CONFIG_SYS_FLASH_QUIET_TEST
4064 If this option is defined, the common CFI flash doesn't
4065 print it's warning upon not recognized FLASH banks. This
4066 is useful, if some of the configured banks are only
4067 optionally available.
4069 - CONFIG_FLASH_SHOW_PROGRESS
4070 If defined (must be an integer), print out countdown
4071 digits and dots. Recommended value: 45 (9..1) for 80
4072 column displays, 15 (3..1) for 40 column displays.
4074 - CONFIG_FLASH_VERIFY
4075 If defined, the content of the flash (destination) is compared
4076 against the source after the write operation. An error message
4077 will be printed when the contents are not identical.
4078 Please note that this option is useless in nearly all cases,
4079 since such flash programming errors usually are detected earlier
4080 while unprotecting/erasing/programming. Please only enable
4081 this option if you really know what you are doing.
4083 - CONFIG_SYS_RX_ETH_BUFFER:
4084 Defines the number of Ethernet receive buffers. On some
4085 Ethernet controllers it is recommended to set this value
4086 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4087 buffers can be full shortly after enabling the interface
4088 on high Ethernet traffic.
4089 Defaults to 4 if not defined.
4091 - CONFIG_ENV_MAX_ENTRIES
4093 Maximum number of entries in the hash table that is used
4094 internally to store the environment settings. The default
4095 setting is supposed to be generous and should work in most
4096 cases. This setting can be used to tune behaviour; see
4097 lib/hashtable.c for details.
4099 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4100 - CONFIG_ENV_FLAGS_LIST_STATIC
4101 Enable validation of the values given to environment variables when
4102 calling env set. Variables can be restricted to only decimal,
4103 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4104 the variables can also be restricted to IP address or MAC address.
4106 The format of the list is:
4107 type_attribute = [s|d|x|b|i|m]
4108 access_attribute = [a|r|o|c]
4109 attributes = type_attribute[access_attribute]
4110 entry = variable_name[:attributes]
4113 The type attributes are:
4114 s - String (default)
4117 b - Boolean ([1yYtT|0nNfF])
4121 The access attributes are:
4127 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4128 Define this to a list (string) to define the ".flags"
4129 environment variable in the default or embedded environment.
4131 - CONFIG_ENV_FLAGS_LIST_STATIC
4132 Define this to a list (string) to define validation that
4133 should be done if an entry is not found in the ".flags"
4134 environment variable. To override a setting in the static
4135 list, simply add an entry for the same variable name to the
4138 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4139 regular expression. This allows multiple variables to define the same
4140 flags without explicitly listing them for each variable.
4142 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4143 If defined, don't allow the -f switch to env set override variable
4146 - CONFIG_SYS_GENERIC_BOARD
4147 This selects the architecture-generic board system instead of the
4148 architecture-specific board files. It is intended to move boards
4149 to this new framework over time. Defining this will disable the
4150 arch/foo/lib/board.c file and use common/board_f.c and
4151 common/board_r.c instead. To use this option your architecture
4152 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4153 If you find problems enabling this option on your board please report
4154 the problem and send patches!
4156 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4157 This is set by OMAP boards for the max time that reset should
4158 be asserted. See doc/README.omap-reset-time for details on how
4159 the value can be calculated on a given board.
4162 If stdint.h is available with your toolchain you can define this
4163 option to enable it. You can provide option 'USE_STDINT=1' when
4164 building U-Boot to enable this.
4166 The following definitions that deal with the placement and management
4167 of environment data (variable area); in general, we support the
4168 following configurations:
4170 - CONFIG_BUILD_ENVCRC:
4172 Builds up envcrc with the target environment so that external utils
4173 may easily extract it and embed it in final U-Boot images.
4175 - CONFIG_ENV_IS_IN_FLASH:
4177 Define this if the environment is in flash memory.
4179 a) The environment occupies one whole flash sector, which is
4180 "embedded" in the text segment with the U-Boot code. This
4181 happens usually with "bottom boot sector" or "top boot
4182 sector" type flash chips, which have several smaller
4183 sectors at the start or the end. For instance, such a
4184 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4185 such a case you would place the environment in one of the
4186 4 kB sectors - with U-Boot code before and after it. With
4187 "top boot sector" type flash chips, you would put the
4188 environment in one of the last sectors, leaving a gap
4189 between U-Boot and the environment.
4191 - CONFIG_ENV_OFFSET:
4193 Offset of environment data (variable area) to the
4194 beginning of flash memory; for instance, with bottom boot
4195 type flash chips the second sector can be used: the offset
4196 for this sector is given here.
4198 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4202 This is just another way to specify the start address of
4203 the flash sector containing the environment (instead of
4206 - CONFIG_ENV_SECT_SIZE:
4208 Size of the sector containing the environment.
4211 b) Sometimes flash chips have few, equal sized, BIG sectors.
4212 In such a case you don't want to spend a whole sector for
4217 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4218 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4219 of this flash sector for the environment. This saves
4220 memory for the RAM copy of the environment.
4222 It may also save flash memory if you decide to use this
4223 when your environment is "embedded" within U-Boot code,
4224 since then the remainder of the flash sector could be used
4225 for U-Boot code. It should be pointed out that this is
4226 STRONGLY DISCOURAGED from a robustness point of view:
4227 updating the environment in flash makes it always
4228 necessary to erase the WHOLE sector. If something goes
4229 wrong before the contents has been restored from a copy in
4230 RAM, your target system will be dead.
4232 - CONFIG_ENV_ADDR_REDUND
4233 CONFIG_ENV_SIZE_REDUND
4235 These settings describe a second storage area used to hold
4236 a redundant copy of the environment data, so that there is
4237 a valid backup copy in case there is a power failure during
4238 a "saveenv" operation.
4240 BE CAREFUL! Any changes to the flash layout, and some changes to the
4241 source code will make it necessary to adapt <board>/u-boot.lds*
4245 - CONFIG_ENV_IS_IN_NVRAM:
4247 Define this if you have some non-volatile memory device
4248 (NVRAM, battery buffered SRAM) which you want to use for the
4254 These two #defines are used to determine the memory area you
4255 want to use for environment. It is assumed that this memory
4256 can just be read and written to, without any special
4259 BE CAREFUL! The first access to the environment happens quite early
4260 in U-Boot initialization (when we try to get the setting of for the
4261 console baudrate). You *MUST* have mapped your NVRAM area then, or
4264 Please note that even with NVRAM we still use a copy of the
4265 environment in RAM: we could work on NVRAM directly, but we want to
4266 keep settings there always unmodified except somebody uses "saveenv"
4267 to save the current settings.
4270 - CONFIG_ENV_IS_IN_EEPROM:
4272 Use this if you have an EEPROM or similar serial access
4273 device and a driver for it.
4275 - CONFIG_ENV_OFFSET:
4278 These two #defines specify the offset and size of the
4279 environment area within the total memory of your EEPROM.
4281 - CONFIG_SYS_I2C_EEPROM_ADDR:
4282 If defined, specified the chip address of the EEPROM device.
4283 The default address is zero.
4285 - CONFIG_SYS_I2C_EEPROM_BUS:
4286 If defined, specified the i2c bus of the EEPROM device.
4288 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4289 If defined, the number of bits used to address bytes in a
4290 single page in the EEPROM device. A 64 byte page, for example
4291 would require six bits.
4293 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4294 If defined, the number of milliseconds to delay between
4295 page writes. The default is zero milliseconds.
4297 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4298 The length in bytes of the EEPROM memory array address. Note
4299 that this is NOT the chip address length!
4301 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4302 EEPROM chips that implement "address overflow" are ones
4303 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4304 address and the extra bits end up in the "chip address" bit
4305 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4308 Note that we consider the length of the address field to
4309 still be one byte because the extra address bits are hidden
4310 in the chip address.
4312 - CONFIG_SYS_EEPROM_SIZE:
4313 The size in bytes of the EEPROM device.
4315 - CONFIG_ENV_EEPROM_IS_ON_I2C
4316 define this, if you have I2C and SPI activated, and your
4317 EEPROM, which holds the environment, is on the I2C bus.
4319 - CONFIG_I2C_ENV_EEPROM_BUS
4320 if you have an Environment on an EEPROM reached over
4321 I2C muxes, you can define here, how to reach this
4322 EEPROM. For example:
4324 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4326 EEPROM which holds the environment, is reached over
4327 a pca9547 i2c mux with address 0x70, channel 3.
4329 - CONFIG_ENV_IS_IN_DATAFLASH:
4331 Define this if you have a DataFlash memory device which you
4332 want to use for the environment.
4334 - CONFIG_ENV_OFFSET:
4338 These three #defines specify the offset and size of the
4339 environment area within the total memory of your DataFlash placed
4340 at the specified address.
4342 - CONFIG_ENV_IS_IN_SPI_FLASH:
4344 Define this if you have a SPI Flash memory device which you
4345 want to use for the environment.
4347 - CONFIG_ENV_OFFSET:
4350 These two #defines specify the offset and size of the
4351 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4352 aligned to an erase sector boundary.
4354 - CONFIG_ENV_SECT_SIZE:
4356 Define the SPI flash's sector size.
4358 - CONFIG_ENV_OFFSET_REDUND (optional):
4360 This setting describes a second storage area of CONFIG_ENV_SIZE
4361 size used to hold a redundant copy of the environment data, so
4362 that there is a valid backup copy in case there is a power failure
4363 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4364 aligned to an erase sector boundary.
4366 - CONFIG_ENV_SPI_BUS (optional):
4367 - CONFIG_ENV_SPI_CS (optional):
4369 Define the SPI bus and chip select. If not defined they will be 0.
4371 - CONFIG_ENV_SPI_MAX_HZ (optional):
4373 Define the SPI max work clock. If not defined then use 1MHz.
4375 - CONFIG_ENV_SPI_MODE (optional):
4377 Define the SPI work mode. If not defined then use SPI_MODE_3.
4379 - CONFIG_ENV_IS_IN_REMOTE:
4381 Define this if you have a remote memory space which you
4382 want to use for the local device's environment.
4387 These two #defines specify the address and size of the
4388 environment area within the remote memory space. The
4389 local device can get the environment from remote memory
4390 space by SRIO or PCIE links.
4392 BE CAREFUL! For some special cases, the local device can not use
4393 "saveenv" command. For example, the local device will get the
4394 environment stored in a remote NOR flash by SRIO or PCIE link,
4395 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4397 - CONFIG_ENV_IS_IN_NAND:
4399 Define this if you have a NAND device which you want to use
4400 for the environment.
4402 - CONFIG_ENV_OFFSET:
4405 These two #defines specify the offset and size of the environment
4406 area within the first NAND device. CONFIG_ENV_OFFSET must be
4407 aligned to an erase block boundary.
4409 - CONFIG_ENV_OFFSET_REDUND (optional):
4411 This setting describes a second storage area of CONFIG_ENV_SIZE
4412 size used to hold a redundant copy of the environment data, so
4413 that there is a valid backup copy in case there is a power failure
4414 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4415 aligned to an erase block boundary.
4417 - CONFIG_ENV_RANGE (optional):
4419 Specifies the length of the region in which the environment
4420 can be written. This should be a multiple of the NAND device's
4421 block size. Specifying a range with more erase blocks than
4422 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4423 the range to be avoided.
4425 - CONFIG_ENV_OFFSET_OOB (optional):
4427 Enables support for dynamically retrieving the offset of the
4428 environment from block zero's out-of-band data. The
4429 "nand env.oob" command can be used to record this offset.
4430 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4431 using CONFIG_ENV_OFFSET_OOB.
4433 - CONFIG_NAND_ENV_DST
4435 Defines address in RAM to which the nand_spl code should copy the
4436 environment. If redundant environment is used, it will be copied to
4437 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4439 - CONFIG_ENV_IS_IN_UBI:
4441 Define this if you have an UBI volume that you want to use for the
4442 environment. This has the benefit of wear-leveling the environment
4443 accesses, which is important on NAND.
4445 - CONFIG_ENV_UBI_PART:
4447 Define this to a string that is the mtd partition containing the UBI.
4449 - CONFIG_ENV_UBI_VOLUME:
4451 Define this to the name of the volume that you want to store the
4454 - CONFIG_ENV_UBI_VOLUME_REDUND:
4456 Define this to the name of another volume to store a second copy of
4457 the environment in. This will enable redundant environments in UBI.
4458 It is assumed that both volumes are in the same MTD partition.
4460 - CONFIG_UBI_SILENCE_MSG
4461 - CONFIG_UBIFS_SILENCE_MSG
4463 You will probably want to define these to avoid a really noisy system
4464 when storing the env in UBI.
4466 - CONFIG_ENV_IS_IN_FAT:
4467 Define this if you want to use the FAT file system for the environment.
4469 - FAT_ENV_INTERFACE:
4471 Define this to a string that is the name of the block device.
4473 - FAT_ENV_DEV_AND_PART:
4475 Define this to a string to specify the partition of the device. It can
4478 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4479 - "D:P": device D partition P. Error occurs if device D has no
4482 - "D" or "D:": device D partition 1 if device D has partition
4483 table, or the whole device D if has no partition
4485 - "D:auto": first partition in device D with bootable flag set.
4486 If none, first valid partition in device D. If no
4487 partition table then means device D.
4491 It's a string of the FAT file name. This file use to store the
4495 This should be defined. Otherwise it cannot save the environment file.
4497 - CONFIG_ENV_IS_IN_MMC:
4499 Define this if you have an MMC device which you want to use for the
4502 - CONFIG_SYS_MMC_ENV_DEV:
4504 Specifies which MMC device the environment is stored in.
4506 - CONFIG_SYS_MMC_ENV_PART (optional):
4508 Specifies which MMC partition the environment is stored in. If not
4509 set, defaults to partition 0, the user area. Common values might be
4510 1 (first MMC boot partition), 2 (second MMC boot partition).
4512 - CONFIG_ENV_OFFSET:
4515 These two #defines specify the offset and size of the environment
4516 area within the specified MMC device.
4518 If offset is positive (the usual case), it is treated as relative to
4519 the start of the MMC partition. If offset is negative, it is treated
4520 as relative to the end of the MMC partition. This can be useful if
4521 your board may be fitted with different MMC devices, which have
4522 different sizes for the MMC partitions, and you always want the
4523 environment placed at the very end of the partition, to leave the
4524 maximum possible space before it, to store other data.
4526 These two values are in units of bytes, but must be aligned to an
4527 MMC sector boundary.
4529 - CONFIG_ENV_OFFSET_REDUND (optional):
4531 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4532 hold a redundant copy of the environment data. This provides a
4533 valid backup copy in case the other copy is corrupted, e.g. due
4534 to a power failure during a "saveenv" operation.
4536 This value may also be positive or negative; this is handled in the
4537 same way as CONFIG_ENV_OFFSET.
4539 This value is also in units of bytes, but must also be aligned to
4540 an MMC sector boundary.
4542 - CONFIG_ENV_SIZE_REDUND (optional):
4544 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4545 set. If this value is set, it must be set to the same value as
4548 - CONFIG_SYS_SPI_INIT_OFFSET
4550 Defines offset to the initial SPI buffer area in DPRAM. The
4551 area is used at an early stage (ROM part) if the environment
4552 is configured to reside in the SPI EEPROM: We need a 520 byte
4553 scratch DPRAM area. It is used between the two initialization
4554 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4555 to be a good choice since it makes it far enough from the
4556 start of the data area as well as from the stack pointer.
4558 Please note that the environment is read-only until the monitor
4559 has been relocated to RAM and a RAM copy of the environment has been
4560 created; also, when using EEPROM you will have to use getenv_f()
4561 until then to read environment variables.
4563 The environment is protected by a CRC32 checksum. Before the monitor
4564 is relocated into RAM, as a result of a bad CRC you will be working
4565 with the compiled-in default environment - *silently*!!! [This is
4566 necessary, because the first environment variable we need is the
4567 "baudrate" setting for the console - if we have a bad CRC, we don't
4568 have any device yet where we could complain.]
4570 Note: once the monitor has been relocated, then it will complain if
4571 the default environment is used; a new CRC is computed as soon as you
4572 use the "saveenv" command to store a valid environment.
4574 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4575 Echo the inverted Ethernet link state to the fault LED.
4577 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4578 also needs to be defined.
4580 - CONFIG_SYS_FAULT_MII_ADDR:
4581 MII address of the PHY to check for the Ethernet link state.
4583 - CONFIG_NS16550_MIN_FUNCTIONS:
4584 Define this if you desire to only have use of the NS16550_init
4585 and NS16550_putc functions for the serial driver located at
4586 drivers/serial/ns16550.c. This option is useful for saving
4587 space for already greatly restricted images, including but not
4588 limited to NAND_SPL configurations.
4590 - CONFIG_DISPLAY_BOARDINFO
4591 Display information about the board that U-Boot is running on
4592 when U-Boot starts up. The board function checkboard() is called
4595 - CONFIG_DISPLAY_BOARDINFO_LATE
4596 Similar to the previous option, but display this information
4597 later, once stdio is running and output goes to the LCD, if
4600 - CONFIG_BOARD_SIZE_LIMIT:
4601 Maximum size of the U-Boot image. When defined, the
4602 build system checks that the actual size does not
4605 Low Level (hardware related) configuration options:
4606 ---------------------------------------------------
4608 - CONFIG_SYS_CACHELINE_SIZE:
4609 Cache Line Size of the CPU.
4611 - CONFIG_SYS_DEFAULT_IMMR:
4612 Default address of the IMMR after system reset.
4614 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4615 and RPXsuper) to be able to adjust the position of
4616 the IMMR register after a reset.
4618 - CONFIG_SYS_CCSRBAR_DEFAULT:
4619 Default (power-on reset) physical address of CCSR on Freescale
4622 - CONFIG_SYS_CCSRBAR:
4623 Virtual address of CCSR. On a 32-bit build, this is typically
4624 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4626 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4627 for cross-platform code that uses that macro instead.
4629 - CONFIG_SYS_CCSRBAR_PHYS:
4630 Physical address of CCSR. CCSR can be relocated to a new
4631 physical address, if desired. In this case, this macro should
4632 be set to that address. Otherwise, it should be set to the
4633 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4634 is typically relocated on 36-bit builds. It is recommended
4635 that this macro be defined via the _HIGH and _LOW macros:
4637 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4638 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4640 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4641 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4642 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4643 used in assembly code, so it must not contain typecasts or
4644 integer size suffixes (e.g. "ULL").
4646 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4647 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4648 used in assembly code, so it must not contain typecasts or
4649 integer size suffixes (e.g. "ULL").
4651 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4652 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4653 forced to a value that ensures that CCSR is not relocated.
4655 - Floppy Disk Support:
4656 CONFIG_SYS_FDC_DRIVE_NUMBER
4658 the default drive number (default value 0)
4660 CONFIG_SYS_ISA_IO_STRIDE
4662 defines the spacing between FDC chipset registers
4665 CONFIG_SYS_ISA_IO_OFFSET
4667 defines the offset of register from address. It
4668 depends on which part of the data bus is connected to
4669 the FDC chipset. (default value 0)
4671 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4672 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4675 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4676 fdc_hw_init() is called at the beginning of the FDC
4677 setup. fdc_hw_init() must be provided by the board
4678 source code. It is used to make hardware-dependent
4682 Most IDE controllers were designed to be connected with PCI
4683 interface. Only few of them were designed for AHB interface.
4684 When software is doing ATA command and data transfer to
4685 IDE devices through IDE-AHB controller, some additional
4686 registers accessing to these kind of IDE-AHB controller
4689 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4690 DO NOT CHANGE unless you know exactly what you're
4691 doing! (11-4) [MPC8xx/82xx systems only]
4693 - CONFIG_SYS_INIT_RAM_ADDR:
4695 Start address of memory area that can be used for
4696 initial data and stack; please note that this must be
4697 writable memory that is working WITHOUT special
4698 initialization, i. e. you CANNOT use normal RAM which
4699 will become available only after programming the
4700 memory controller and running certain initialization
4703 U-Boot uses the following memory types:
4704 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4705 - MPC824X: data cache
4706 - PPC4xx: data cache
4708 - CONFIG_SYS_GBL_DATA_OFFSET:
4710 Offset of the initial data structure in the memory
4711 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4712 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4713 data is located at the end of the available space
4714 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4715 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4716 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4717 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4720 On the MPC824X (or other systems that use the data
4721 cache for initial memory) the address chosen for
4722 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4723 point to an otherwise UNUSED address space between
4724 the top of RAM and the start of the PCI space.
4726 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4728 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4730 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4732 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4734 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4736 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4738 - CONFIG_SYS_OR_TIMING_SDRAM:
4741 - CONFIG_SYS_MAMR_PTA:
4742 periodic timer for refresh
4744 - CONFIG_SYS_DER: Debug Event Register (37-47)
4746 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4747 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4748 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4749 CONFIG_SYS_BR1_PRELIM:
4750 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4752 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4753 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4754 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4755 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4757 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4758 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4759 Machine Mode Register and Memory Periodic Timer
4760 Prescaler definitions (SDRAM timing)
4762 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4763 enable I2C microcode relocation patch (MPC8xx);
4764 define relocation offset in DPRAM [DSP2]
4766 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4767 enable SMC microcode relocation patch (MPC8xx);
4768 define relocation offset in DPRAM [SMC1]
4770 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4771 enable SPI microcode relocation patch (MPC8xx);
4772 define relocation offset in DPRAM [SCC4]
4774 - CONFIG_SYS_USE_OSCCLK:
4775 Use OSCM clock mode on MBX8xx board. Be careful,
4776 wrong setting might damage your board. Read
4777 doc/README.MBX before setting this variable!
4779 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4780 Offset of the bootmode word in DPRAM used by post
4781 (Power On Self Tests). This definition overrides
4782 #define'd default value in commproc.h resp.
4785 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4786 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4787 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4788 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4789 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4790 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4791 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4792 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4793 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4795 - CONFIG_PCI_DISABLE_PCIE:
4796 Disable PCI-Express on systems where it is supported but not
4799 - CONFIG_PCI_ENUM_ONLY
4800 Only scan through and get the devices on the buses.
4801 Don't do any setup work, presumably because someone or
4802 something has already done it, and we don't need to do it
4803 a second time. Useful for platforms that are pre-booted
4804 by coreboot or similar.
4806 - CONFIG_PCI_INDIRECT_BRIDGE:
4807 Enable support for indirect PCI bridges.
4810 Chip has SRIO or not
4813 Board has SRIO 1 port available
4816 Board has SRIO 2 port available
4818 - CONFIG_SRIO_PCIE_BOOT_MASTER
4819 Board can support master function for Boot from SRIO and PCIE
4821 - CONFIG_SYS_SRIOn_MEM_VIRT:
4822 Virtual Address of SRIO port 'n' memory region
4824 - CONFIG_SYS_SRIOn_MEM_PHYS:
4825 Physical Address of SRIO port 'n' memory region
4827 - CONFIG_SYS_SRIOn_MEM_SIZE:
4828 Size of SRIO port 'n' memory region
4830 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4831 Defined to tell the NAND controller that the NAND chip is using
4833 Not all NAND drivers use this symbol.
4834 Example of drivers that use it:
4835 - drivers/mtd/nand/ndfc.c
4836 - drivers/mtd/nand/mxc_nand.c
4838 - CONFIG_SYS_NDFC_EBC0_CFG
4839 Sets the EBC0_CFG register for the NDFC. If not defined
4840 a default value will be used.
4843 Get DDR timing information from an I2C EEPROM. Common
4844 with pluggable memory modules such as SODIMMs
4847 I2C address of the SPD EEPROM
4849 - CONFIG_SYS_SPD_BUS_NUM
4850 If SPD EEPROM is on an I2C bus other than the first
4851 one, specify here. Note that the value must resolve
4852 to something your driver can deal with.
4854 - CONFIG_SYS_DDR_RAW_TIMING
4855 Get DDR timing information from other than SPD. Common with
4856 soldered DDR chips onboard without SPD. DDR raw timing
4857 parameters are extracted from datasheet and hard-coded into
4858 header files or board specific files.
4860 - CONFIG_FSL_DDR_INTERACTIVE
4861 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4863 - CONFIG_FSL_DDR_SYNC_REFRESH
4864 Enable sync of refresh for multiple controllers.
4866 - CONFIG_FSL_DDR_BIST
4867 Enable built-in memory test for Freescale DDR controllers.
4869 - CONFIG_SYS_83XX_DDR_USES_CS0
4870 Only for 83xx systems. If specified, then DDR should
4871 be configured using CS0 and CS1 instead of CS2 and CS3.
4873 - CONFIG_ETHER_ON_FEC[12]
4874 Define to enable FEC[12] on a 8xx series processor.
4876 - CONFIG_FEC[12]_PHY
4877 Define to the hardcoded PHY address which corresponds
4878 to the given FEC; i. e.
4879 #define CONFIG_FEC1_PHY 4
4880 means that the PHY with address 4 is connected to FEC1
4882 When set to -1, means to probe for first available.
4884 - CONFIG_FEC[12]_PHY_NORXERR
4885 The PHY does not have a RXERR line (RMII only).
4886 (so program the FEC to ignore it).
4889 Enable RMII mode for all FECs.
4890 Note that this is a global option, we can't
4891 have one FEC in standard MII mode and another in RMII mode.
4893 - CONFIG_CRC32_VERIFY
4894 Add a verify option to the crc32 command.
4897 => crc32 -v <address> <count> <crc32>
4899 Where address/count indicate a memory area
4900 and crc32 is the correct crc32 which the
4904 Add the "loopw" memory command. This only takes effect if
4905 the memory commands are activated globally (CONFIG_CMD_MEM).
4908 Add the "mdc" and "mwc" memory commands. These are cyclic
4913 This command will print 4 bytes (10,11,12,13) each 500 ms.
4915 => mwc.l 100 12345678 10
4916 This command will write 12345678 to address 100 all 10 ms.
4918 This only takes effect if the memory commands are activated
4919 globally (CONFIG_CMD_MEM).
4921 - CONFIG_SKIP_LOWLEVEL_INIT
4922 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4923 low level initializations (like setting up the memory
4924 controller) are omitted and/or U-Boot does not
4925 relocate itself into RAM.
4927 Normally this variable MUST NOT be defined. The only
4928 exception is when U-Boot is loaded (to RAM) by some
4929 other boot loader or by a debugger which performs
4930 these initializations itself.
4933 Modifies the behaviour of start.S when compiling a loader
4934 that is executed before the actual U-Boot. E.g. when
4935 compiling a NAND SPL.
4938 Modifies the behaviour of start.S when compiling a loader
4939 that is executed after the SPL and before the actual U-Boot.
4940 It is loaded by the SPL.
4942 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4943 Only for 85xx systems. If this variable is specified, the section
4944 .resetvec is not kept and the section .bootpg is placed in the
4945 previous 4k of the .text section.
4947 - CONFIG_ARCH_MAP_SYSMEM
4948 Generally U-Boot (and in particular the md command) uses
4949 effective address. It is therefore not necessary to regard
4950 U-Boot address as virtual addresses that need to be translated
4951 to physical addresses. However, sandbox requires this, since
4952 it maintains its own little RAM buffer which contains all
4953 addressable memory. This option causes some memory accesses
4954 to be mapped through map_sysmem() / unmap_sysmem().
4956 - CONFIG_USE_ARCH_MEMCPY
4957 CONFIG_USE_ARCH_MEMSET
4958 If these options are used a optimized version of memcpy/memset will
4959 be used if available. These functions may be faster under some
4960 conditions but may increase the binary size.
4962 - CONFIG_X86_RESET_VECTOR
4963 If defined, the x86 reset vector code is included. This is not
4964 needed when U-Boot is running from Coreboot.
4967 Defines the MPU clock speed (in MHz).
4969 NOTE : currently only supported on AM335x platforms.
4971 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4972 Enables the RTC32K OSC on AM33xx based plattforms
4974 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4975 Option to disable subpage write in NAND driver
4976 driver that uses this:
4977 drivers/mtd/nand/davinci_nand.c
4979 Freescale QE/FMAN Firmware Support:
4980 -----------------------------------
4982 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4983 loading of "firmware", which is encoded in the QE firmware binary format.
4984 This firmware often needs to be loaded during U-Boot booting, so macros
4985 are used to identify the storage device (NOR flash, SPI, etc) and the address
4988 - CONFIG_SYS_FMAN_FW_ADDR
4989 The address in the storage device where the FMAN microcode is located. The
4990 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4993 - CONFIG_SYS_QE_FW_ADDR
4994 The address in the storage device where the QE microcode is located. The
4995 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4998 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4999 The maximum possible size of the firmware. The firmware binary format
5000 has a field that specifies the actual size of the firmware, but it
5001 might not be possible to read any part of the firmware unless some
5002 local storage is allocated to hold the entire firmware first.
5004 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5005 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5006 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5007 virtual address in NOR flash.
5009 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5010 Specifies that QE/FMAN firmware is located in NAND flash.
5011 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5013 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5014 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5015 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5017 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5018 Specifies that QE/FMAN firmware is located on the primary SPI
5019 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5021 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5022 Specifies that QE/FMAN firmware is located in the remote (master)
5023 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5024 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5025 window->master inbound window->master LAW->the ucode address in
5026 master's memory space.
5028 Freescale Layerscape Management Complex Firmware Support:
5029 ---------------------------------------------------------
5030 The Freescale Layerscape Management Complex (MC) supports the loading of
5032 This firmware often needs to be loaded during U-Boot booting, so macros
5033 are used to identify the storage device (NOR flash, SPI, etc) and the address
5036 - CONFIG_FSL_MC_ENET
5037 Enable the MC driver for Layerscape SoCs.
5039 - CONFIG_SYS_LS_MC_FW_ADDR
5040 The address in the storage device where the firmware is located. The
5041 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5044 - CONFIG_SYS_LS_MC_FW_LENGTH
5045 The maximum possible size of the firmware. The firmware binary format
5046 has a field that specifies the actual size of the firmware, but it
5047 might not be possible to read any part of the firmware unless some
5048 local storage is allocated to hold the entire firmware first.
5050 - CONFIG_SYS_LS_MC_FW_IN_NOR
5051 Specifies that MC firmware is located in NOR flash, mapped as
5052 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5053 virtual address in NOR flash.
5055 Freescale Layerscape Debug Server Support:
5056 -------------------------------------------
5057 The Freescale Layerscape Debug Server Support supports the loading of
5058 "Debug Server firmware" and triggering SP boot-rom.
5059 This firmware often needs to be loaded during U-Boot booting.
5061 - CONFIG_FSL_DEBUG_SERVER
5062 Enable the Debug Server for Layerscape SoCs.
5064 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5065 Define minimum DDR size required for debug server image
5067 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5068 Define minimum DDR size to be hided from top of the DDR memory
5073 In order to achieve reproducible builds, timestamps used in the U-Boot build
5074 process have to be set to a fixed value.
5076 This is done using the SOURCE_DATE_EPOCH environment variable.
5077 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5078 option for U-Boot or an environment variable in U-Boot.
5080 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5082 Building the Software:
5083 ======================
5085 Building U-Boot has been tested in several native build environments
5086 and in many different cross environments. Of course we cannot support
5087 all possibly existing versions of cross development tools in all
5088 (potentially obsolete) versions. In case of tool chain problems we
5089 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5090 which is extensively used to build and test U-Boot.
5092 If you are not using a native environment, it is assumed that you
5093 have GNU cross compiling tools available in your path. In this case,
5094 you must set the environment variable CROSS_COMPILE in your shell.
5095 Note that no changes to the Makefile or any other source files are
5096 necessary. For example using the ELDK on a 4xx CPU, please enter:
5098 $ CROSS_COMPILE=ppc_4xx-
5099 $ export CROSS_COMPILE
5101 Note: If you wish to generate Windows versions of the utilities in
5102 the tools directory you can use the MinGW toolchain
5103 (http://www.mingw.org). Set your HOST tools to the MinGW
5104 toolchain and execute 'make tools'. For example:
5106 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5108 Binaries such as tools/mkimage.exe will be created which can
5109 be executed on computers running Windows.
5111 U-Boot is intended to be simple to build. After installing the
5112 sources you must configure U-Boot for one specific board type. This
5117 where "NAME_defconfig" is the name of one of the existing configu-
5118 rations; see boards.cfg for supported names.
5120 Note: for some board special configuration names may exist; check if
5121 additional information is available from the board vendor; for
5122 instance, the TQM823L systems are available without (standard)
5123 or with LCD support. You can select such additional "features"
5124 when choosing the configuration, i. e.
5126 make TQM823L_defconfig
5127 - will configure for a plain TQM823L, i. e. no LCD support
5129 make TQM823L_LCD_defconfig
5130 - will configure for a TQM823L with U-Boot console on LCD
5135 Finally, type "make all", and you should get some working U-Boot
5136 images ready for download to / installation on your system:
5138 - "u-boot.bin" is a raw binary image
5139 - "u-boot" is an image in ELF binary format
5140 - "u-boot.srec" is in Motorola S-Record format
5142 By default the build is performed locally and the objects are saved
5143 in the source directory. One of the two methods can be used to change
5144 this behavior and build U-Boot to some external directory:
5146 1. Add O= to the make command line invocations:
5148 make O=/tmp/build distclean
5149 make O=/tmp/build NAME_defconfig
5150 make O=/tmp/build all
5152 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5154 export KBUILD_OUTPUT=/tmp/build
5159 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5163 Please be aware that the Makefiles assume you are using GNU make, so
5164 for instance on NetBSD you might need to use "gmake" instead of
5168 If the system board that you have is not listed, then you will need
5169 to port U-Boot to your hardware platform. To do this, follow these
5172 1. Add a new configuration option for your board to the toplevel
5173 "boards.cfg" file, using the existing entries as examples.
5174 Follow the instructions there to keep the boards in order.
5175 2. Create a new directory to hold your board specific code. Add any
5176 files you need. In your board directory, you will need at least
5177 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5178 3. Create a new configuration file "include/configs/<board>.h" for
5180 3. If you're porting U-Boot to a new CPU, then also create a new
5181 directory to hold your CPU specific code. Add any files you need.
5182 4. Run "make <board>_defconfig" with your new name.
5183 5. Type "make", and you should get a working "u-boot.srec" file
5184 to be installed on your target system.
5185 6. Debug and solve any problems that might arise.
5186 [Of course, this last step is much harder than it sounds.]
5189 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5190 ==============================================================
5192 If you have modified U-Boot sources (for instance added a new board
5193 or support for new devices, a new CPU, etc.) you are expected to
5194 provide feedback to the other developers. The feedback normally takes
5195 the form of a "patch", i. e. a context diff against a certain (latest
5196 official or latest in the git repository) version of U-Boot sources.
5198 But before you submit such a patch, please verify that your modifi-
5199 cation did not break existing code. At least make sure that *ALL* of
5200 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5201 just run the "MAKEALL" script, which will configure and build U-Boot
5202 for ALL supported system. Be warned, this will take a while. You can
5203 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5204 environment variable to the script, i. e. to use the ELDK cross tools
5207 CROSS_COMPILE=ppc_8xx- MAKEALL
5209 or to build on a native PowerPC system you can type
5211 CROSS_COMPILE=' ' MAKEALL
5213 When using the MAKEALL script, the default behaviour is to build
5214 U-Boot in the source directory. This location can be changed by
5215 setting the BUILD_DIR environment variable. Also, for each target
5216 built, the MAKEALL script saves two log files (<target>.ERR and
5217 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5218 location can be changed by setting the MAKEALL_LOGDIR environment
5219 variable. For example:
5221 export BUILD_DIR=/tmp/build
5222 export MAKEALL_LOGDIR=/tmp/log
5223 CROSS_COMPILE=ppc_8xx- MAKEALL
5225 With the above settings build objects are saved in the /tmp/build,
5226 log files are saved in the /tmp/log and the source tree remains clean
5227 during the whole build process.
5230 See also "U-Boot Porting Guide" below.
5233 Monitor Commands - Overview:
5234 ============================
5236 go - start application at address 'addr'
5237 run - run commands in an environment variable
5238 bootm - boot application image from memory
5239 bootp - boot image via network using BootP/TFTP protocol
5240 bootz - boot zImage from memory
5241 tftpboot- boot image via network using TFTP protocol
5242 and env variables "ipaddr" and "serverip"
5243 (and eventually "gatewayip")
5244 tftpput - upload a file via network using TFTP protocol
5245 rarpboot- boot image via network using RARP/TFTP protocol
5246 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5247 loads - load S-Record file over serial line
5248 loadb - load binary file over serial line (kermit mode)
5250 mm - memory modify (auto-incrementing)
5251 nm - memory modify (constant address)
5252 mw - memory write (fill)
5254 cmp - memory compare
5255 crc32 - checksum calculation
5256 i2c - I2C sub-system
5257 sspi - SPI utility commands
5258 base - print or set address offset
5259 printenv- print environment variables
5260 setenv - set environment variables
5261 saveenv - save environment variables to persistent storage
5262 protect - enable or disable FLASH write protection
5263 erase - erase FLASH memory
5264 flinfo - print FLASH memory information
5265 nand - NAND memory operations (see doc/README.nand)
5266 bdinfo - print Board Info structure
5267 iminfo - print header information for application image
5268 coninfo - print console devices and informations
5269 ide - IDE sub-system
5270 loop - infinite loop on address range
5271 loopw - infinite write loop on address range
5272 mtest - simple RAM test
5273 icache - enable or disable instruction cache
5274 dcache - enable or disable data cache
5275 reset - Perform RESET of the CPU
5276 echo - echo args to console
5277 version - print monitor version
5278 help - print online help
5279 ? - alias for 'help'
5282 Monitor Commands - Detailed Description:
5283 ========================================
5287 For now: just type "help <command>".
5290 Environment Variables:
5291 ======================
5293 U-Boot supports user configuration using Environment Variables which
5294 can be made persistent by saving to Flash memory.
5296 Environment Variables are set using "setenv", printed using
5297 "printenv", and saved to Flash using "saveenv". Using "setenv"
5298 without a value can be used to delete a variable from the
5299 environment. As long as you don't save the environment you are
5300 working with an in-memory copy. In case the Flash area containing the
5301 environment is erased by accident, a default environment is provided.
5303 Some configuration options can be set using Environment Variables.
5305 List of environment variables (most likely not complete):
5307 baudrate - see CONFIG_BAUDRATE
5309 bootdelay - see CONFIG_BOOTDELAY
5311 bootcmd - see CONFIG_BOOTCOMMAND
5313 bootargs - Boot arguments when booting an RTOS image
5315 bootfile - Name of the image to load with TFTP
5317 bootm_low - Memory range available for image processing in the bootm
5318 command can be restricted. This variable is given as
5319 a hexadecimal number and defines lowest address allowed
5320 for use by the bootm command. See also "bootm_size"
5321 environment variable. Address defined by "bootm_low" is
5322 also the base of the initial memory mapping for the Linux
5323 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5326 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5327 This variable is given as a hexadecimal number and it
5328 defines the size of the memory region starting at base
5329 address bootm_low that is accessible by the Linux kernel
5330 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5331 as the default value if it is defined, and bootm_size is
5334 bootm_size - Memory range available for image processing in the bootm
5335 command can be restricted. This variable is given as
5336 a hexadecimal number and defines the size of the region
5337 allowed for use by the bootm command. See also "bootm_low"
5338 environment variable.
5340 updatefile - Location of the software update file on a TFTP server, used
5341 by the automatic software update feature. Please refer to
5342 documentation in doc/README.update for more details.
5344 autoload - if set to "no" (any string beginning with 'n'),
5345 "bootp" will just load perform a lookup of the
5346 configuration from the BOOTP server, but not try to
5347 load any image using TFTP
5349 autostart - if set to "yes", an image loaded using the "bootp",
5350 "rarpboot", "tftpboot" or "diskboot" commands will
5351 be automatically started (by internally calling
5354 If set to "no", a standalone image passed to the
5355 "bootm" command will be copied to the load address
5356 (and eventually uncompressed), but NOT be started.
5357 This can be used to load and uncompress arbitrary
5360 fdt_high - if set this restricts the maximum address that the
5361 flattened device tree will be copied into upon boot.
5362 For example, if you have a system with 1 GB memory
5363 at physical address 0x10000000, while Linux kernel
5364 only recognizes the first 704 MB as low memory, you
5365 may need to set fdt_high as 0x3C000000 to have the
5366 device tree blob be copied to the maximum address
5367 of the 704 MB low memory, so that Linux kernel can
5368 access it during the boot procedure.
5370 If this is set to the special value 0xFFFFFFFF then
5371 the fdt will not be copied at all on boot. For this
5372 to work it must reside in writable memory, have
5373 sufficient padding on the end of it for u-boot to
5374 add the information it needs into it, and the memory
5375 must be accessible by the kernel.
5377 fdtcontroladdr- if set this is the address of the control flattened
5378 device tree used by U-Boot when CONFIG_OF_CONTROL is
5381 i2cfast - (PPC405GP|PPC405EP only)
5382 if set to 'y' configures Linux I2C driver for fast
5383 mode (400kHZ). This environment variable is used in
5384 initialization code. So, for changes to be effective
5385 it must be saved and board must be reset.
5387 initrd_high - restrict positioning of initrd images:
5388 If this variable is not set, initrd images will be
5389 copied to the highest possible address in RAM; this
5390 is usually what you want since it allows for
5391 maximum initrd size. If for some reason you want to
5392 make sure that the initrd image is loaded below the
5393 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5394 variable to a value of "no" or "off" or "0".
5395 Alternatively, you can set it to a maximum upper
5396 address to use (U-Boot will still check that it
5397 does not overwrite the U-Boot stack and data).
5399 For instance, when you have a system with 16 MB
5400 RAM, and want to reserve 4 MB from use by Linux,
5401 you can do this by adding "mem=12M" to the value of
5402 the "bootargs" variable. However, now you must make
5403 sure that the initrd image is placed in the first
5404 12 MB as well - this can be done with
5406 setenv initrd_high 00c00000
5408 If you set initrd_high to 0xFFFFFFFF, this is an
5409 indication to U-Boot that all addresses are legal
5410 for the Linux kernel, including addresses in flash
5411 memory. In this case U-Boot will NOT COPY the
5412 ramdisk at all. This may be useful to reduce the
5413 boot time on your system, but requires that this
5414 feature is supported by your Linux kernel.
5416 ipaddr - IP address; needed for tftpboot command
5418 loadaddr - Default load address for commands like "bootp",
5419 "rarpboot", "tftpboot", "loadb" or "diskboot"
5421 loads_echo - see CONFIG_LOADS_ECHO
5423 serverip - TFTP server IP address; needed for tftpboot command
5425 bootretry - see CONFIG_BOOT_RETRY_TIME
5427 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5429 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5431 ethprime - controls which interface is used first.
5433 ethact - controls which interface is currently active.
5434 For example you can do the following
5436 => setenv ethact FEC
5437 => ping 192.168.0.1 # traffic sent on FEC
5438 => setenv ethact SCC
5439 => ping 10.0.0.1 # traffic sent on SCC
5441 ethrotate - When set to "no" U-Boot does not go through all
5442 available network interfaces.
5443 It just stays at the currently selected interface.
5445 netretry - When set to "no" each network operation will
5446 either succeed or fail without retrying.
5447 When set to "once" the network operation will
5448 fail when all the available network interfaces
5449 are tried once without success.
5450 Useful on scripts which control the retry operation
5453 npe_ucode - set load address for the NPE microcode
5455 silent_linux - If set then Linux will be told to boot silently, by
5456 changing the console to be empty. If "yes" it will be
5457 made silent. If "no" it will not be made silent. If
5458 unset, then it will be made silent if the U-Boot console
5461 tftpsrcport - If this is set, the value is used for TFTP's
5464 tftpdstport - If this is set, the value is used for TFTP's UDP
5465 destination port instead of the Well Know Port 69.
5467 tftpblocksize - Block size to use for TFTP transfers; if not set,
5468 we use the TFTP server's default block size
5470 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5471 seconds, minimum value is 1000 = 1 second). Defines
5472 when a packet is considered to be lost so it has to
5473 be retransmitted. The default is 5000 = 5 seconds.
5474 Lowering this value may make downloads succeed
5475 faster in networks with high packet loss rates or
5476 with unreliable TFTP servers.
5478 vlan - When set to a value < 4095 the traffic over
5479 Ethernet is encapsulated/received over 802.1q
5482 The following image location variables contain the location of images
5483 used in booting. The "Image" column gives the role of the image and is
5484 not an environment variable name. The other columns are environment
5485 variable names. "File Name" gives the name of the file on a TFTP
5486 server, "RAM Address" gives the location in RAM the image will be
5487 loaded to, and "Flash Location" gives the image's address in NOR
5488 flash or offset in NAND flash.
5490 *Note* - these variables don't have to be defined for all boards, some
5491 boards currently use other variables for these purposes, and some
5492 boards use these variables for other purposes.
5494 Image File Name RAM Address Flash Location
5495 ----- --------- ----------- --------------
5496 u-boot u-boot u-boot_addr_r u-boot_addr
5497 Linux kernel bootfile kernel_addr_r kernel_addr
5498 device tree blob fdtfile fdt_addr_r fdt_addr
5499 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5501 The following environment variables may be used and automatically
5502 updated by the network boot commands ("bootp" and "rarpboot"),
5503 depending the information provided by your boot server:
5505 bootfile - see above
5506 dnsip - IP address of your Domain Name Server
5507 dnsip2 - IP address of your secondary Domain Name Server
5508 gatewayip - IP address of the Gateway (Router) to use
5509 hostname - Target hostname
5511 netmask - Subnet Mask
5512 rootpath - Pathname of the root filesystem on the NFS server
5513 serverip - see above
5516 There are two special Environment Variables:
5518 serial# - contains hardware identification information such
5519 as type string and/or serial number
5520 ethaddr - Ethernet address
5522 These variables can be set only once (usually during manufacturing of
5523 the board). U-Boot refuses to delete or overwrite these variables
5524 once they have been set once.
5527 Further special Environment Variables:
5529 ver - Contains the U-Boot version string as printed
5530 with the "version" command. This variable is
5531 readonly (see CONFIG_VERSION_VARIABLE).
5534 Please note that changes to some configuration parameters may take
5535 only effect after the next boot (yes, that's just like Windoze :-).
5538 Callback functions for environment variables:
5539 ---------------------------------------------
5541 For some environment variables, the behavior of u-boot needs to change
5542 when their values are changed. This functionality allows functions to
5543 be associated with arbitrary variables. On creation, overwrite, or
5544 deletion, the callback will provide the opportunity for some side
5545 effect to happen or for the change to be rejected.
5547 The callbacks are named and associated with a function using the
5548 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5550 These callbacks are associated with variables in one of two ways. The
5551 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5552 in the board configuration to a string that defines a list of
5553 associations. The list must be in the following format:
5555 entry = variable_name[:callback_name]
5558 If the callback name is not specified, then the callback is deleted.
5559 Spaces are also allowed anywhere in the list.
5561 Callbacks can also be associated by defining the ".callbacks" variable
5562 with the same list format above. Any association in ".callbacks" will
5563 override any association in the static list. You can define
5564 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5565 ".callbacks" environment variable in the default or embedded environment.
5567 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5568 regular expression. This allows multiple variables to be connected to
5569 the same callback without explicitly listing them all out.
5572 Command Line Parsing:
5573 =====================
5575 There are two different command line parsers available with U-Boot:
5576 the old "simple" one, and the much more powerful "hush" shell:
5578 Old, simple command line parser:
5579 --------------------------------
5581 - supports environment variables (through setenv / saveenv commands)
5582 - several commands on one line, separated by ';'
5583 - variable substitution using "... ${name} ..." syntax
5584 - special characters ('$', ';') can be escaped by prefixing with '\',
5586 setenv bootcmd bootm \${address}
5587 - You can also escape text by enclosing in single apostrophes, for example:
5588 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5593 - similar to Bourne shell, with control structures like
5594 if...then...else...fi, for...do...done; while...do...done,
5595 until...do...done, ...
5596 - supports environment ("global") variables (through setenv / saveenv
5597 commands) and local shell variables (through standard shell syntax
5598 "name=value"); only environment variables can be used with "run"
5604 (1) If a command line (or an environment variable executed by a "run"
5605 command) contains several commands separated by semicolon, and
5606 one of these commands fails, then the remaining commands will be
5609 (2) If you execute several variables with one call to run (i. e.
5610 calling run with a list of variables as arguments), any failing
5611 command will cause "run" to terminate, i. e. the remaining
5612 variables are not executed.
5614 Note for Redundant Ethernet Interfaces:
5615 =======================================
5617 Some boards come with redundant Ethernet interfaces; U-Boot supports
5618 such configurations and is capable of automatic selection of a
5619 "working" interface when needed. MAC assignment works as follows:
5621 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5622 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5623 "eth1addr" (=>eth1), "eth2addr", ...
5625 If the network interface stores some valid MAC address (for instance
5626 in SROM), this is used as default address if there is NO correspon-
5627 ding setting in the environment; if the corresponding environment
5628 variable is set, this overrides the settings in the card; that means:
5630 o If the SROM has a valid MAC address, and there is no address in the
5631 environment, the SROM's address is used.
5633 o If there is no valid address in the SROM, and a definition in the
5634 environment exists, then the value from the environment variable is
5637 o If both the SROM and the environment contain a MAC address, and
5638 both addresses are the same, this MAC address is used.
5640 o If both the SROM and the environment contain a MAC address, and the
5641 addresses differ, the value from the environment is used and a
5644 o If neither SROM nor the environment contain a MAC address, an error
5645 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5646 a random, locally-assigned MAC is used.
5648 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5649 will be programmed into hardware as part of the initialization process. This
5650 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5651 The naming convention is as follows:
5652 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5657 U-Boot is capable of booting (and performing other auxiliary operations on)
5658 images in two formats:
5660 New uImage format (FIT)
5661 -----------------------
5663 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5664 to Flattened Device Tree). It allows the use of images with multiple
5665 components (several kernels, ramdisks, etc.), with contents protected by
5666 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5672 Old image format is based on binary files which can be basically anything,
5673 preceded by a special header; see the definitions in include/image.h for
5674 details; basically, the header defines the following image properties:
5676 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5677 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5678 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5679 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5681 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5682 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5683 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5684 * Compression Type (uncompressed, gzip, bzip2)
5690 The header is marked by a special Magic Number, and both the header
5691 and the data portions of the image are secured against corruption by
5698 Although U-Boot should support any OS or standalone application
5699 easily, the main focus has always been on Linux during the design of
5702 U-Boot includes many features that so far have been part of some
5703 special "boot loader" code within the Linux kernel. Also, any
5704 "initrd" images to be used are no longer part of one big Linux image;
5705 instead, kernel and "initrd" are separate images. This implementation
5706 serves several purposes:
5708 - the same features can be used for other OS or standalone
5709 applications (for instance: using compressed images to reduce the
5710 Flash memory footprint)
5712 - it becomes much easier to port new Linux kernel versions because
5713 lots of low-level, hardware dependent stuff are done by U-Boot
5715 - the same Linux kernel image can now be used with different "initrd"
5716 images; of course this also means that different kernel images can
5717 be run with the same "initrd". This makes testing easier (you don't
5718 have to build a new "zImage.initrd" Linux image when you just
5719 change a file in your "initrd"). Also, a field-upgrade of the
5720 software is easier now.
5726 Porting Linux to U-Boot based systems:
5727 ---------------------------------------
5729 U-Boot cannot save you from doing all the necessary modifications to
5730 configure the Linux device drivers for use with your target hardware
5731 (no, we don't intend to provide a full virtual machine interface to
5734 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5736 Just make sure your machine specific header file (for instance
5737 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5738 Information structure as we define in include/asm-<arch>/u-boot.h,
5739 and make sure that your definition of IMAP_ADDR uses the same value
5740 as your U-Boot configuration in CONFIG_SYS_IMMR.
5742 Note that U-Boot now has a driver model, a unified model for drivers.
5743 If you are adding a new driver, plumb it into driver model. If there
5744 is no uclass available, you are encouraged to create one. See
5748 Configuring the Linux kernel:
5749 -----------------------------
5751 No specific requirements for U-Boot. Make sure you have some root
5752 device (initial ramdisk, NFS) for your target system.
5755 Building a Linux Image:
5756 -----------------------
5758 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5759 not used. If you use recent kernel source, a new build target
5760 "uImage" will exist which automatically builds an image usable by
5761 U-Boot. Most older kernels also have support for a "pImage" target,
5762 which was introduced for our predecessor project PPCBoot and uses a
5763 100% compatible format.
5767 make TQM850L_defconfig
5772 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5773 encapsulate a compressed Linux kernel image with header information,
5774 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5776 * build a standard "vmlinux" kernel image (in ELF binary format):
5778 * convert the kernel into a raw binary image:
5780 ${CROSS_COMPILE}-objcopy -O binary \
5781 -R .note -R .comment \
5782 -S vmlinux linux.bin
5784 * compress the binary image:
5788 * package compressed binary image for U-Boot:
5790 mkimage -A ppc -O linux -T kernel -C gzip \
5791 -a 0 -e 0 -n "Linux Kernel Image" \
5792 -d linux.bin.gz uImage
5795 The "mkimage" tool can also be used to create ramdisk images for use
5796 with U-Boot, either separated from the Linux kernel image, or
5797 combined into one file. "mkimage" encapsulates the images with a 64
5798 byte header containing information about target architecture,
5799 operating system, image type, compression method, entry points, time
5800 stamp, CRC32 checksums, etc.
5802 "mkimage" can be called in two ways: to verify existing images and
5803 print the header information, or to build new images.
5805 In the first form (with "-l" option) mkimage lists the information
5806 contained in the header of an existing U-Boot image; this includes
5807 checksum verification:
5809 tools/mkimage -l image
5810 -l ==> list image header information
5812 The second form (with "-d" option) is used to build a U-Boot image
5813 from a "data file" which is used as image payload:
5815 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5816 -n name -d data_file image
5817 -A ==> set architecture to 'arch'
5818 -O ==> set operating system to 'os'
5819 -T ==> set image type to 'type'
5820 -C ==> set compression type 'comp'
5821 -a ==> set load address to 'addr' (hex)
5822 -e ==> set entry point to 'ep' (hex)
5823 -n ==> set image name to 'name'
5824 -d ==> use image data from 'datafile'
5826 Right now, all Linux kernels for PowerPC systems use the same load
5827 address (0x00000000), but the entry point address depends on the
5830 - 2.2.x kernels have the entry point at 0x0000000C,
5831 - 2.3.x and later kernels have the entry point at 0x00000000.
5833 So a typical call to build a U-Boot image would read:
5835 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5836 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5837 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5838 > examples/uImage.TQM850L
5839 Image Name: 2.4.4 kernel for TQM850L
5840 Created: Wed Jul 19 02:34:59 2000
5841 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5842 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5843 Load Address: 0x00000000
5844 Entry Point: 0x00000000
5846 To verify the contents of the image (or check for corruption):
5848 -> tools/mkimage -l examples/uImage.TQM850L
5849 Image Name: 2.4.4 kernel for TQM850L
5850 Created: Wed Jul 19 02:34:59 2000
5851 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5852 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5853 Load Address: 0x00000000
5854 Entry Point: 0x00000000
5856 NOTE: for embedded systems where boot time is critical you can trade
5857 speed for memory and install an UNCOMPRESSED image instead: this
5858 needs more space in Flash, but boots much faster since it does not
5859 need to be uncompressed:
5861 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5862 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5863 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5864 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5865 > examples/uImage.TQM850L-uncompressed
5866 Image Name: 2.4.4 kernel for TQM850L
5867 Created: Wed Jul 19 02:34:59 2000
5868 Image Type: PowerPC Linux Kernel Image (uncompressed)
5869 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5870 Load Address: 0x00000000
5871 Entry Point: 0x00000000
5874 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5875 when your kernel is intended to use an initial ramdisk:
5877 -> tools/mkimage -n 'Simple Ramdisk Image' \
5878 > -A ppc -O linux -T ramdisk -C gzip \
5879 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5880 Image Name: Simple Ramdisk Image
5881 Created: Wed Jan 12 14:01:50 2000
5882 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5883 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5884 Load Address: 0x00000000
5885 Entry Point: 0x00000000
5887 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5888 option performs the converse operation of the mkimage's second form (the "-d"
5889 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5892 tools/dumpimage -i image -T type -p position data_file
5893 -i ==> extract from the 'image' a specific 'data_file'
5894 -T ==> set image type to 'type'
5895 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5898 Installing a Linux Image:
5899 -------------------------
5901 To downloading a U-Boot image over the serial (console) interface,
5902 you must convert the image to S-Record format:
5904 objcopy -I binary -O srec examples/image examples/image.srec
5906 The 'objcopy' does not understand the information in the U-Boot
5907 image header, so the resulting S-Record file will be relative to
5908 address 0x00000000. To load it to a given address, you need to
5909 specify the target address as 'offset' parameter with the 'loads'
5912 Example: install the image to address 0x40100000 (which on the
5913 TQM8xxL is in the first Flash bank):
5915 => erase 40100000 401FFFFF
5921 ## Ready for S-Record download ...
5922 ~>examples/image.srec
5923 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5925 15989 15990 15991 15992
5926 [file transfer complete]
5928 ## Start Addr = 0x00000000
5931 You can check the success of the download using the 'iminfo' command;
5932 this includes a checksum verification so you can be sure no data
5933 corruption happened:
5937 ## Checking Image at 40100000 ...
5938 Image Name: 2.2.13 for initrd on TQM850L
5939 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5940 Data Size: 335725 Bytes = 327 kB = 0 MB
5941 Load Address: 00000000
5942 Entry Point: 0000000c
5943 Verifying Checksum ... OK
5949 The "bootm" command is used to boot an application that is stored in
5950 memory (RAM or Flash). In case of a Linux kernel image, the contents
5951 of the "bootargs" environment variable is passed to the kernel as
5952 parameters. You can check and modify this variable using the
5953 "printenv" and "setenv" commands:
5956 => printenv bootargs
5957 bootargs=root=/dev/ram
5959 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5961 => printenv bootargs
5962 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5965 ## Booting Linux kernel at 40020000 ...
5966 Image Name: 2.2.13 for NFS on TQM850L
5967 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5968 Data Size: 381681 Bytes = 372 kB = 0 MB
5969 Load Address: 00000000
5970 Entry Point: 0000000c
5971 Verifying Checksum ... OK
5972 Uncompressing Kernel Image ... OK
5973 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
5974 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5975 time_init: decrementer frequency = 187500000/60
5976 Calibrating delay loop... 49.77 BogoMIPS
5977 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5980 If you want to boot a Linux kernel with initial RAM disk, you pass
5981 the memory addresses of both the kernel and the initrd image (PPBCOOT
5982 format!) to the "bootm" command:
5984 => imi 40100000 40200000
5986 ## Checking Image at 40100000 ...
5987 Image Name: 2.2.13 for initrd on TQM850L
5988 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5989 Data Size: 335725 Bytes = 327 kB = 0 MB
5990 Load Address: 00000000
5991 Entry Point: 0000000c
5992 Verifying Checksum ... OK
5994 ## Checking Image at 40200000 ...
5995 Image Name: Simple Ramdisk Image
5996 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5997 Data Size: 566530 Bytes = 553 kB = 0 MB
5998 Load Address: 00000000
5999 Entry Point: 00000000
6000 Verifying Checksum ... OK
6002 => bootm 40100000 40200000
6003 ## Booting Linux kernel at 40100000 ...
6004 Image Name: 2.2.13 for initrd on TQM850L
6005 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6006 Data Size: 335725 Bytes = 327 kB = 0 MB
6007 Load Address: 00000000
6008 Entry Point: 0000000c
6009 Verifying Checksum ... OK
6010 Uncompressing Kernel Image ... OK
6011 ## Loading RAMDisk Image at 40200000 ...
6012 Image Name: Simple Ramdisk Image
6013 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6014 Data Size: 566530 Bytes = 553 kB = 0 MB
6015 Load Address: 00000000
6016 Entry Point: 00000000
6017 Verifying Checksum ... OK
6018 Loading Ramdisk ... OK
6019 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
6020 Boot arguments: root=/dev/ram
6021 time_init: decrementer frequency = 187500000/60
6022 Calibrating delay loop... 49.77 BogoMIPS
6024 RAMDISK: Compressed image found at block 0
6025 VFS: Mounted root (ext2 filesystem).
6029 Boot Linux and pass a flat device tree:
6032 First, U-Boot must be compiled with the appropriate defines. See the section
6033 titled "Linux Kernel Interface" above for a more in depth explanation. The
6034 following is an example of how to start a kernel and pass an updated
6040 oft=oftrees/mpc8540ads.dtb
6041 => tftp $oftaddr $oft
6042 Speed: 1000, full duplex
6044 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6045 Filename 'oftrees/mpc8540ads.dtb'.
6046 Load address: 0x300000
6049 Bytes transferred = 4106 (100a hex)
6050 => tftp $loadaddr $bootfile
6051 Speed: 1000, full duplex
6053 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6055 Load address: 0x200000
6056 Loading:############
6058 Bytes transferred = 1029407 (fb51f hex)
6063 => bootm $loadaddr - $oftaddr
6064 ## Booting image at 00200000 ...
6065 Image Name: Linux-2.6.17-dirty
6066 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6067 Data Size: 1029343 Bytes = 1005.2 kB
6068 Load Address: 00000000
6069 Entry Point: 00000000
6070 Verifying Checksum ... OK
6071 Uncompressing Kernel Image ... OK
6072 Booting using flat device tree at 0x300000
6073 Using MPC85xx ADS machine description
6074 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6078 More About U-Boot Image Types:
6079 ------------------------------
6081 U-Boot supports the following image types:
6083 "Standalone Programs" are directly runnable in the environment
6084 provided by U-Boot; it is expected that (if they behave
6085 well) you can continue to work in U-Boot after return from
6086 the Standalone Program.
6087 "OS Kernel Images" are usually images of some Embedded OS which
6088 will take over control completely. Usually these programs
6089 will install their own set of exception handlers, device
6090 drivers, set up the MMU, etc. - this means, that you cannot
6091 expect to re-enter U-Boot except by resetting the CPU.
6092 "RAMDisk Images" are more or less just data blocks, and their
6093 parameters (address, size) are passed to an OS kernel that is
6095 "Multi-File Images" contain several images, typically an OS
6096 (Linux) kernel image and one or more data images like
6097 RAMDisks. This construct is useful for instance when you want
6098 to boot over the network using BOOTP etc., where the boot
6099 server provides just a single image file, but you want to get
6100 for instance an OS kernel and a RAMDisk image.
6102 "Multi-File Images" start with a list of image sizes, each
6103 image size (in bytes) specified by an "uint32_t" in network
6104 byte order. This list is terminated by an "(uint32_t)0".
6105 Immediately after the terminating 0 follow the images, one by
6106 one, all aligned on "uint32_t" boundaries (size rounded up to
6107 a multiple of 4 bytes).
6109 "Firmware Images" are binary images containing firmware (like
6110 U-Boot or FPGA images) which usually will be programmed to
6113 "Script files" are command sequences that will be executed by
6114 U-Boot's command interpreter; this feature is especially
6115 useful when you configure U-Boot to use a real shell (hush)
6116 as command interpreter.
6118 Booting the Linux zImage:
6119 -------------------------
6121 On some platforms, it's possible to boot Linux zImage. This is done
6122 using the "bootz" command. The syntax of "bootz" command is the same
6123 as the syntax of "bootm" command.
6125 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6126 kernel with raw initrd images. The syntax is slightly different, the
6127 address of the initrd must be augmented by it's size, in the following
6128 format: "<initrd addres>:<initrd size>".
6134 One of the features of U-Boot is that you can dynamically load and
6135 run "standalone" applications, which can use some resources of
6136 U-Boot like console I/O functions or interrupt services.
6138 Two simple examples are included with the sources:
6143 'examples/hello_world.c' contains a small "Hello World" Demo
6144 application; it is automatically compiled when you build U-Boot.
6145 It's configured to run at address 0x00040004, so you can play with it
6149 ## Ready for S-Record download ...
6150 ~>examples/hello_world.srec
6151 1 2 3 4 5 6 7 8 9 10 11 ...
6152 [file transfer complete]
6154 ## Start Addr = 0x00040004
6156 => go 40004 Hello World! This is a test.
6157 ## Starting application at 0x00040004 ...
6168 Hit any key to exit ...
6170 ## Application terminated, rc = 0x0
6172 Another example, which demonstrates how to register a CPM interrupt
6173 handler with the U-Boot code, can be found in 'examples/timer.c'.
6174 Here, a CPM timer is set up to generate an interrupt every second.
6175 The interrupt service routine is trivial, just printing a '.'
6176 character, but this is just a demo program. The application can be
6177 controlled by the following keys:
6179 ? - print current values og the CPM Timer registers
6180 b - enable interrupts and start timer
6181 e - stop timer and disable interrupts
6182 q - quit application
6185 ## Ready for S-Record download ...
6186 ~>examples/timer.srec
6187 1 2 3 4 5 6 7 8 9 10 11 ...
6188 [file transfer complete]
6190 ## Start Addr = 0x00040004
6193 ## Starting application at 0x00040004 ...
6196 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6199 [q, b, e, ?] Set interval 1000000 us
6202 [q, b, e, ?] ........
6203 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6206 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6209 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6212 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6214 [q, b, e, ?] ...Stopping timer
6216 [q, b, e, ?] ## Application terminated, rc = 0x0
6222 Over time, many people have reported problems when trying to use the
6223 "minicom" terminal emulation program for serial download. I (wd)
6224 consider minicom to be broken, and recommend not to use it. Under
6225 Unix, I recommend to use C-Kermit for general purpose use (and
6226 especially for kermit binary protocol download ("loadb" command), and
6227 use "cu" for S-Record download ("loads" command). See
6228 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6229 for help with kermit.
6232 Nevertheless, if you absolutely want to use it try adding this
6233 configuration to your "File transfer protocols" section:
6235 Name Program Name U/D FullScr IO-Red. Multi
6236 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6237 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6243 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6244 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6246 Building requires a cross environment; it is known to work on
6247 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6248 need gmake since the Makefiles are not compatible with BSD make).
6249 Note that the cross-powerpc package does not install include files;
6250 attempting to build U-Boot will fail because <machine/ansi.h> is
6251 missing. This file has to be installed and patched manually:
6253 # cd /usr/pkg/cross/powerpc-netbsd/include
6255 # ln -s powerpc machine
6256 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6257 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6259 Native builds *don't* work due to incompatibilities between native
6260 and U-Boot include files.
6262 Booting assumes that (the first part of) the image booted is a
6263 stage-2 loader which in turn loads and then invokes the kernel
6264 proper. Loader sources will eventually appear in the NetBSD source
6265 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6266 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6269 Implementation Internals:
6270 =========================
6272 The following is not intended to be a complete description of every
6273 implementation detail. However, it should help to understand the
6274 inner workings of U-Boot and make it easier to port it to custom
6278 Initial Stack, Global Data:
6279 ---------------------------
6281 The implementation of U-Boot is complicated by the fact that U-Boot
6282 starts running out of ROM (flash memory), usually without access to
6283 system RAM (because the memory controller is not initialized yet).
6284 This means that we don't have writable Data or BSS segments, and BSS
6285 is not initialized as zero. To be able to get a C environment working
6286 at all, we have to allocate at least a minimal stack. Implementation
6287 options for this are defined and restricted by the CPU used: Some CPU
6288 models provide on-chip memory (like the IMMR area on MPC8xx and
6289 MPC826x processors), on others (parts of) the data cache can be
6290 locked as (mis-) used as memory, etc.
6292 Chris Hallinan posted a good summary of these issues to the
6293 U-Boot mailing list:
6295 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6296 From: "Chris Hallinan" <clh@net1plus.com>
6297 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6300 Correct me if I'm wrong, folks, but the way I understand it
6301 is this: Using DCACHE as initial RAM for Stack, etc, does not
6302 require any physical RAM backing up the cache. The cleverness
6303 is that the cache is being used as a temporary supply of
6304 necessary storage before the SDRAM controller is setup. It's
6305 beyond the scope of this list to explain the details, but you
6306 can see how this works by studying the cache architecture and
6307 operation in the architecture and processor-specific manuals.
6309 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6310 is another option for the system designer to use as an
6311 initial stack/RAM area prior to SDRAM being available. Either
6312 option should work for you. Using CS 4 should be fine if your
6313 board designers haven't used it for something that would
6314 cause you grief during the initial boot! It is frequently not
6317 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6318 with your processor/board/system design. The default value
6319 you will find in any recent u-boot distribution in
6320 walnut.h should work for you. I'd set it to a value larger
6321 than your SDRAM module. If you have a 64MB SDRAM module, set
6322 it above 400_0000. Just make sure your board has no resources
6323 that are supposed to respond to that address! That code in
6324 start.S has been around a while and should work as is when
6325 you get the config right.
6330 It is essential to remember this, since it has some impact on the C
6331 code for the initialization procedures:
6333 * Initialized global data (data segment) is read-only. Do not attempt
6336 * Do not use any uninitialized global data (or implicitly initialized
6337 as zero data - BSS segment) at all - this is undefined, initiali-
6338 zation is performed later (when relocating to RAM).
6340 * Stack space is very limited. Avoid big data buffers or things like
6343 Having only the stack as writable memory limits means we cannot use
6344 normal global data to share information between the code. But it
6345 turned out that the implementation of U-Boot can be greatly
6346 simplified by making a global data structure (gd_t) available to all
6347 functions. We could pass a pointer to this data as argument to _all_
6348 functions, but this would bloat the code. Instead we use a feature of
6349 the GCC compiler (Global Register Variables) to share the data: we
6350 place a pointer (gd) to the global data into a register which we
6351 reserve for this purpose.
6353 When choosing a register for such a purpose we are restricted by the
6354 relevant (E)ABI specifications for the current architecture, and by
6355 GCC's implementation.
6357 For PowerPC, the following registers have specific use:
6359 R2: reserved for system use
6360 R3-R4: parameter passing and return values
6361 R5-R10: parameter passing
6362 R13: small data area pointer
6366 (U-Boot also uses R12 as internal GOT pointer. r12
6367 is a volatile register so r12 needs to be reset when
6368 going back and forth between asm and C)
6370 ==> U-Boot will use R2 to hold a pointer to the global data
6372 Note: on PPC, we could use a static initializer (since the
6373 address of the global data structure is known at compile time),
6374 but it turned out that reserving a register results in somewhat
6375 smaller code - although the code savings are not that big (on
6376 average for all boards 752 bytes for the whole U-Boot image,
6377 624 text + 127 data).
6379 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6380 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6382 ==> U-Boot will use P3 to hold a pointer to the global data
6384 On ARM, the following registers are used:
6386 R0: function argument word/integer result
6387 R1-R3: function argument word
6388 R9: platform specific
6389 R10: stack limit (used only if stack checking is enabled)
6390 R11: argument (frame) pointer
6391 R12: temporary workspace
6394 R15: program counter
6396 ==> U-Boot will use R9 to hold a pointer to the global data
6398 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6400 On Nios II, the ABI is documented here:
6401 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6403 ==> U-Boot will use gp to hold a pointer to the global data
6405 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6406 to access small data sections, so gp is free.
6408 On NDS32, the following registers are used:
6410 R0-R1: argument/return
6412 R15: temporary register for assembler
6413 R16: trampoline register
6414 R28: frame pointer (FP)
6415 R29: global pointer (GP)
6416 R30: link register (LP)
6417 R31: stack pointer (SP)
6418 PC: program counter (PC)
6420 ==> U-Boot will use R10 to hold a pointer to the global data
6422 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6423 or current versions of GCC may "optimize" the code too much.
6428 U-Boot runs in system state and uses physical addresses, i.e. the
6429 MMU is not used either for address mapping nor for memory protection.
6431 The available memory is mapped to fixed addresses using the memory
6432 controller. In this process, a contiguous block is formed for each
6433 memory type (Flash, SDRAM, SRAM), even when it consists of several
6434 physical memory banks.
6436 U-Boot is installed in the first 128 kB of the first Flash bank (on
6437 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6438 booting and sizing and initializing DRAM, the code relocates itself
6439 to the upper end of DRAM. Immediately below the U-Boot code some
6440 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6441 configuration setting]. Below that, a structure with global Board
6442 Info data is placed, followed by the stack (growing downward).
6444 Additionally, some exception handler code is copied to the low 8 kB
6445 of DRAM (0x00000000 ... 0x00001FFF).
6447 So a typical memory configuration with 16 MB of DRAM could look like
6450 0x0000 0000 Exception Vector code
6453 0x0000 2000 Free for Application Use
6459 0x00FB FF20 Monitor Stack (Growing downward)
6460 0x00FB FFAC Board Info Data and permanent copy of global data
6461 0x00FC 0000 Malloc Arena
6464 0x00FE 0000 RAM Copy of Monitor Code
6465 ... eventually: LCD or video framebuffer
6466 ... eventually: pRAM (Protected RAM - unchanged by reset)
6467 0x00FF FFFF [End of RAM]
6470 System Initialization:
6471 ----------------------
6473 In the reset configuration, U-Boot starts at the reset entry point
6474 (on most PowerPC systems at address 0x00000100). Because of the reset
6475 configuration for CS0# this is a mirror of the on board Flash memory.
6476 To be able to re-map memory U-Boot then jumps to its link address.
6477 To be able to implement the initialization code in C, a (small!)
6478 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6479 which provide such a feature like MPC8xx or MPC8260), or in a locked
6480 part of the data cache. After that, U-Boot initializes the CPU core,
6481 the caches and the SIU.
6483 Next, all (potentially) available memory banks are mapped using a
6484 preliminary mapping. For example, we put them on 512 MB boundaries
6485 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6486 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6487 programmed for SDRAM access. Using the temporary configuration, a
6488 simple memory test is run that determines the size of the SDRAM
6491 When there is more than one SDRAM bank, and the banks are of
6492 different size, the largest is mapped first. For equal size, the first
6493 bank (CS2#) is mapped first. The first mapping is always for address
6494 0x00000000, with any additional banks following immediately to create
6495 contiguous memory starting from 0.
6497 Then, the monitor installs itself at the upper end of the SDRAM area
6498 and allocates memory for use by malloc() and for the global Board
6499 Info data; also, the exception vector code is copied to the low RAM
6500 pages, and the final stack is set up.
6502 Only after this relocation will you have a "normal" C environment;
6503 until that you are restricted in several ways, mostly because you are
6504 running from ROM, and because the code will have to be relocated to a
6508 U-Boot Porting Guide:
6509 ----------------------
6511 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6515 int main(int argc, char *argv[])
6517 sighandler_t no_more_time;
6519 signal(SIGALRM, no_more_time);
6520 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6522 if (available_money > available_manpower) {
6523 Pay consultant to port U-Boot;
6527 Download latest U-Boot source;
6529 Subscribe to u-boot mailing list;
6532 email("Hi, I am new to U-Boot, how do I get started?");
6535 Read the README file in the top level directory;
6536 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6537 Read applicable doc/*.README;
6538 Read the source, Luke;
6539 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6542 if (available_money > toLocalCurrency ($2500))
6545 Add a lot of aggravation and time;
6547 if (a similar board exists) { /* hopefully... */
6548 cp -a board/<similar> board/<myboard>
6549 cp include/configs/<similar>.h include/configs/<myboard>.h
6551 Create your own board support subdirectory;
6552 Create your own board include/configs/<myboard>.h file;
6554 Edit new board/<myboard> files
6555 Edit new include/configs/<myboard>.h
6560 Add / modify source code;
6564 email("Hi, I am having problems...");
6566 Send patch file to the U-Boot email list;
6567 if (reasonable critiques)
6568 Incorporate improvements from email list code review;
6570 Defend code as written;
6576 void no_more_time (int sig)
6585 All contributions to U-Boot should conform to the Linux kernel
6586 coding style; see the file "Documentation/CodingStyle" and the script
6587 "scripts/Lindent" in your Linux kernel source directory.
6589 Source files originating from a different project (for example the
6590 MTD subsystem) are generally exempt from these guidelines and are not
6591 reformatted to ease subsequent migration to newer versions of those
6594 Please note that U-Boot is implemented in C (and to some small parts in
6595 Assembler); no C++ is used, so please do not use C++ style comments (//)
6598 Please also stick to the following formatting rules:
6599 - remove any trailing white space
6600 - use TAB characters for indentation and vertical alignment, not spaces
6601 - make sure NOT to use DOS '\r\n' line feeds
6602 - do not add more than 2 consecutive empty lines to source files
6603 - do not add trailing empty lines to source files
6605 Submissions which do not conform to the standards may be returned
6606 with a request to reformat the changes.
6612 Since the number of patches for U-Boot is growing, we need to
6613 establish some rules. Submissions which do not conform to these rules
6614 may be rejected, even when they contain important and valuable stuff.
6616 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6618 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6619 see http://lists.denx.de/mailman/listinfo/u-boot
6621 When you send a patch, please include the following information with
6624 * For bug fixes: a description of the bug and how your patch fixes
6625 this bug. Please try to include a way of demonstrating that the
6626 patch actually fixes something.
6628 * For new features: a description of the feature and your
6631 * A CHANGELOG entry as plaintext (separate from the patch)
6633 * For major contributions, your entry to the CREDITS file
6635 * When you add support for a new board, don't forget to add a
6636 maintainer e-mail address to the boards.cfg file, too.
6638 * If your patch adds new configuration options, don't forget to
6639 document these in the README file.
6641 * The patch itself. If you are using git (which is *strongly*
6642 recommended) you can easily generate the patch using the
6643 "git format-patch". If you then use "git send-email" to send it to
6644 the U-Boot mailing list, you will avoid most of the common problems
6645 with some other mail clients.
6647 If you cannot use git, use "diff -purN OLD NEW". If your version of
6648 diff does not support these options, then get the latest version of
6651 The current directory when running this command shall be the parent
6652 directory of the U-Boot source tree (i. e. please make sure that
6653 your patch includes sufficient directory information for the
6656 We prefer patches as plain text. MIME attachments are discouraged,
6657 and compressed attachments must not be used.
6659 * If one logical set of modifications affects or creates several
6660 files, all these changes shall be submitted in a SINGLE patch file.
6662 * Changesets that contain different, unrelated modifications shall be
6663 submitted as SEPARATE patches, one patch per changeset.
6668 * Before sending the patch, run the MAKEALL script on your patched
6669 source tree and make sure that no errors or warnings are reported
6670 for any of the boards.
6672 * Keep your modifications to the necessary minimum: A patch
6673 containing several unrelated changes or arbitrary reformats will be
6674 returned with a request to re-formatting / split it.
6676 * If you modify existing code, make sure that your new code does not
6677 add to the memory footprint of the code ;-) Small is beautiful!
6678 When adding new features, these should compile conditionally only
6679 (using #ifdef), and the resulting code with the new feature
6680 disabled must not need more memory than the old code without your
6683 * Remember that there is a size limit of 100 kB per message on the
6684 u-boot mailing list. Bigger patches will be moderated. If they are
6685 reasonable and not too big, they will be acknowledged. But patches
6686 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob