2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_430973
705 CONFIG_ARM_ERRATA_454179
706 CONFIG_ARM_ERRATA_621766
707 CONFIG_ARM_ERRATA_798870
710 CONFIG_TEGRA_SUPPORT_NON_SECURE
712 Support executing U-Boot in non-secure (NS) mode. Certain
713 impossible actions will be skipped if the CPU is in NS mode,
714 such as ARM architectural timer initialization.
716 - Linux Kernel Interface:
719 U-Boot stores all clock information in Hz
720 internally. For binary compatibility with older Linux
721 kernels (which expect the clocks passed in the
722 bd_info data to be in MHz) the environment variable
723 "clocks_in_mhz" can be defined so that U-Boot
724 converts clock data to MHZ before passing it to the
726 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
727 "clocks_in_mhz=1" is automatically included in the
730 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
732 When transferring memsize parameter to Linux, some versions
733 expect it to be in bytes, others in MB.
734 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
738 New kernel versions are expecting firmware settings to be
739 passed using flattened device trees (based on open firmware
743 * New libfdt-based support
744 * Adds the "fdt" command
745 * The bootm command automatically updates the fdt
747 OF_CPU - The proper name of the cpus node (only required for
748 MPC512X and MPC5xxx based boards).
749 OF_SOC - The proper name of the soc node (only required for
750 MPC512X and MPC5xxx based boards).
751 OF_TBCLK - The timebase frequency.
752 OF_STDOUT_PATH - The path to the console device
754 boards with QUICC Engines require OF_QE to set UCC MAC
757 CONFIG_OF_BOARD_SETUP
759 Board code has addition modification that it wants to make
760 to the flat device tree before handing it off to the kernel
762 CONFIG_OF_SYSTEM_SETUP
764 Other code has addition modification that it wants to make
765 to the flat device tree before handing it off to the kernel.
766 This causes ft_system_setup() to be called before booting
771 This define fills in the correct boot CPU in the boot
772 param header, the default value is zero if undefined.
776 U-Boot can detect if an IDE device is present or not.
777 If not, and this new config option is activated, U-Boot
778 removes the ATA node from the DTS before booting Linux,
779 so the Linux IDE driver does not probe the device and
780 crash. This is needed for buggy hardware (uc101) where
781 no pull down resistor is connected to the signal IDE5V_DD7.
783 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
785 This setting is mandatory for all boards that have only one
786 machine type and must be used to specify the machine type
787 number as it appears in the ARM machine registry
788 (see http://www.arm.linux.org.uk/developer/machines/).
789 Only boards that have multiple machine types supported
790 in a single configuration file and the machine type is
791 runtime discoverable, do not have to use this setting.
793 - vxWorks boot parameters:
795 bootvx constructs a valid bootline using the following
796 environments variables: bootfile, ipaddr, serverip, hostname.
797 It loads the vxWorks image pointed bootfile.
799 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
800 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
801 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
802 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
804 CONFIG_SYS_VXWORKS_ADD_PARAMS
806 Add it at the end of the bootline. E.g "u=username pw=secret"
808 Note: If a "bootargs" environment is defined, it will overwride
809 the defaults discussed just above.
811 - Cache Configuration:
812 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
813 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
814 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
816 - Cache Configuration for ARM:
817 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
819 CONFIG_SYS_PL310_BASE - Physical base address of PL310
820 controller register space
825 Define this if you want support for Amba PrimeCell PL010 UARTs.
829 Define this if you want support for Amba PrimeCell PL011 UARTs.
833 If you have Amba PrimeCell PL011 UARTs, set this variable to
834 the clock speed of the UARTs.
838 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
839 define this to a list of base addresses for each (supported)
840 port. See e.g. include/configs/versatile.h
842 CONFIG_PL011_SERIAL_RLCR
844 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
845 have separate receive and transmit line control registers. Set
846 this variable to initialize the extra register.
848 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
850 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
851 boot loader that has already initialized the UART. Define this
852 variable to flush the UART at init time.
854 CONFIG_SERIAL_HW_FLOW_CONTROL
856 Define this variable to enable hw flow control in serial driver.
857 Current user of this option is drivers/serial/nsl16550.c driver
860 Depending on board, define exactly one serial port
861 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
862 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
863 console by defining CONFIG_8xx_CONS_NONE
865 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
866 port routines must be defined elsewhere
867 (i.e. serial_init(), serial_getc(), ...)
870 Enables console device for a color framebuffer. Needs following
871 defines (cf. smiLynxEM, i8042)
872 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
874 VIDEO_HW_RECTFILL graphic chip supports
877 VIDEO_HW_BITBLT graphic chip supports
878 bit-blit (cf. smiLynxEM)
879 VIDEO_VISIBLE_COLS visible pixel columns
881 VIDEO_VISIBLE_ROWS visible pixel rows
882 VIDEO_PIXEL_SIZE bytes per pixel
883 VIDEO_DATA_FORMAT graphic data format
884 (0-5, cf. cfb_console.c)
885 VIDEO_FB_ADRS framebuffer address
886 VIDEO_KBD_INIT_FCT keyboard int fct
887 (i.e. i8042_kbd_init())
888 VIDEO_TSTC_FCT test char fct
890 VIDEO_GETC_FCT get char fct
892 CONFIG_CONSOLE_CURSOR cursor drawing on/off
893 (requires blink timer
895 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
896 CONFIG_CONSOLE_TIME display time/date info in
898 (requires CONFIG_CMD_DATE)
899 CONFIG_VIDEO_LOGO display Linux logo in
901 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
902 linux_logo.h for logo.
903 Requires CONFIG_VIDEO_LOGO
904 CONFIG_CONSOLE_EXTRA_INFO
905 additional board info beside
908 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
909 a limited number of ANSI escape sequences (cursor control,
910 erase functions and limited graphics rendition control).
912 When CONFIG_CFB_CONSOLE is defined, video console is
913 default i/o. Serial console can be forced with
914 environment 'console=serial'.
916 When CONFIG_SILENT_CONSOLE is defined, all console
917 messages (by U-Boot and Linux!) can be silenced with
918 the "silent" environment variable. See
919 doc/README.silent for more information.
921 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
923 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
927 CONFIG_BAUDRATE - in bps
928 Select one of the baudrates listed in
929 CONFIG_SYS_BAUDRATE_TABLE, see below.
930 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
932 - Console Rx buffer length
933 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
934 the maximum receive buffer length for the SMC.
935 This option is actual only for 82xx and 8xx possible.
936 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
937 must be defined, to setup the maximum idle timeout for
940 - Pre-Console Buffer:
941 Prior to the console being initialised (i.e. serial UART
942 initialised etc) all console output is silently discarded.
943 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
944 buffer any console messages prior to the console being
945 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
946 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
947 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
948 bytes are output before the console is initialised, the
949 earlier bytes are discarded.
951 'Sane' compilers will generate smaller code if
952 CONFIG_PRE_CON_BUF_SZ is a power of 2
954 - Safe printf() functions
955 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
956 the printf() functions. These are defined in
957 include/vsprintf.h and include snprintf(), vsnprintf() and
958 so on. Code size increase is approximately 300-500 bytes.
959 If this option is not given then these functions will
960 silently discard their buffer size argument - this means
961 you are not getting any overflow checking in this case.
963 - Boot Delay: CONFIG_BOOTDELAY - in seconds
964 Delay before automatically booting the default image;
965 set to -1 to disable autoboot.
966 set to -2 to autoboot with no delay and not check for abort
967 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
969 See doc/README.autoboot for these options that
970 work with CONFIG_BOOTDELAY. None are required.
971 CONFIG_BOOT_RETRY_TIME
972 CONFIG_BOOT_RETRY_MIN
973 CONFIG_AUTOBOOT_KEYED
974 CONFIG_AUTOBOOT_PROMPT
975 CONFIG_AUTOBOOT_DELAY_STR
976 CONFIG_AUTOBOOT_STOP_STR
977 CONFIG_AUTOBOOT_DELAY_STR2
978 CONFIG_AUTOBOOT_STOP_STR2
979 CONFIG_ZERO_BOOTDELAY_CHECK
980 CONFIG_RESET_TO_RETRY
984 Only needed when CONFIG_BOOTDELAY is enabled;
985 define a command string that is automatically executed
986 when no character is read on the console interface
987 within "Boot Delay" after reset.
990 This can be used to pass arguments to the bootm
991 command. The value of CONFIG_BOOTARGS goes into the
992 environment value "bootargs".
994 CONFIG_RAMBOOT and CONFIG_NFSBOOT
995 The value of these goes into the environment as
996 "ramboot" and "nfsboot" respectively, and can be used
997 as a convenience, when switching between booting from
1001 CONFIG_BOOTCOUNT_LIMIT
1002 Implements a mechanism for detecting a repeating reboot
1004 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1006 CONFIG_BOOTCOUNT_ENV
1007 If no softreset save registers are found on the hardware
1008 "bootcount" is stored in the environment. To prevent a
1009 saveenv on all reboots, the environment variable
1010 "upgrade_available" is used. If "upgrade_available" is
1011 0, "bootcount" is always 0, if "upgrade_available" is
1012 1 "bootcount" is incremented in the environment.
1013 So the Userspace Applikation must set the "upgrade_available"
1014 and "bootcount" variable to 0, if a boot was successfully.
1016 - Pre-Boot Commands:
1019 When this option is #defined, the existence of the
1020 environment variable "preboot" will be checked
1021 immediately before starting the CONFIG_BOOTDELAY
1022 countdown and/or running the auto-boot command resp.
1023 entering interactive mode.
1025 This feature is especially useful when "preboot" is
1026 automatically generated or modified. For an example
1027 see the LWMON board specific code: here "preboot" is
1028 modified when the user holds down a certain
1029 combination of keys on the (special) keyboard when
1032 - Serial Download Echo Mode:
1034 If defined to 1, all characters received during a
1035 serial download (using the "loads" command) are
1036 echoed back. This might be needed by some terminal
1037 emulations (like "cu"), but may as well just take
1038 time on others. This setting #define's the initial
1039 value of the "loads_echo" environment variable.
1041 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1042 CONFIG_KGDB_BAUDRATE
1043 Select one of the baudrates listed in
1044 CONFIG_SYS_BAUDRATE_TABLE, see below.
1046 - Monitor Functions:
1047 Monitor commands can be included or excluded
1048 from the build by using the #include files
1049 <config_cmd_all.h> and #undef'ing unwanted
1050 commands, or using <config_cmd_default.h>
1051 and augmenting with additional #define's
1052 for wanted commands.
1054 The default command configuration includes all commands
1055 except those marked below with a "*".
1057 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1058 CONFIG_CMD_ASKENV * ask for env variable
1059 CONFIG_CMD_BDI bdinfo
1060 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1061 CONFIG_CMD_BMP * BMP support
1062 CONFIG_CMD_BSP * Board specific commands
1063 CONFIG_CMD_BOOTD bootd
1064 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1065 CONFIG_CMD_CACHE * icache, dcache
1066 CONFIG_CMD_CLK * clock command support
1067 CONFIG_CMD_CONSOLE coninfo
1068 CONFIG_CMD_CRC32 * crc32
1069 CONFIG_CMD_DATE * support for RTC, date/time...
1070 CONFIG_CMD_DHCP * DHCP support
1071 CONFIG_CMD_DIAG * Diagnostics
1072 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1073 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1074 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1075 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1076 CONFIG_CMD_DTT * Digital Therm and Thermostat
1077 CONFIG_CMD_ECHO echo arguments
1078 CONFIG_CMD_EDITENV edit env variable
1079 CONFIG_CMD_EEPROM * EEPROM read/write support
1080 CONFIG_CMD_ELF * bootelf, bootvx
1081 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1082 CONFIG_CMD_ENV_FLAGS * display details about env flags
1083 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1084 CONFIG_CMD_EXPORTENV * export the environment
1085 CONFIG_CMD_EXT2 * ext2 command support
1086 CONFIG_CMD_EXT4 * ext4 command support
1087 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1088 that work for multiple fs types
1089 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1090 CONFIG_CMD_SAVEENV saveenv
1091 CONFIG_CMD_FDC * Floppy Disk Support
1092 CONFIG_CMD_FAT * FAT command support
1093 CONFIG_CMD_FLASH flinfo, erase, protect
1094 CONFIG_CMD_FPGA FPGA device initialization support
1095 CONFIG_CMD_FUSE * Device fuse support
1096 CONFIG_CMD_GETTIME * Get time since boot
1097 CONFIG_CMD_GO * the 'go' command (exec code)
1098 CONFIG_CMD_GREPENV * search environment
1099 CONFIG_CMD_HASH * calculate hash / digest
1100 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1101 CONFIG_CMD_I2C * I2C serial bus support
1102 CONFIG_CMD_IDE * IDE harddisk support
1103 CONFIG_CMD_IMI iminfo
1104 CONFIG_CMD_IMLS List all images found in NOR flash
1105 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1106 CONFIG_CMD_IMMAP * IMMR dump support
1107 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1108 CONFIG_CMD_IMPORTENV * import an environment
1109 CONFIG_CMD_INI * import data from an ini file into the env
1110 CONFIG_CMD_IRQ * irqinfo
1111 CONFIG_CMD_ITEST Integer/string test of 2 values
1112 CONFIG_CMD_JFFS2 * JFFS2 Support
1113 CONFIG_CMD_KGDB * kgdb
1114 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1115 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1117 CONFIG_CMD_LOADB loadb
1118 CONFIG_CMD_LOADS loads
1119 CONFIG_CMD_MD5SUM * print md5 message digest
1120 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1121 CONFIG_CMD_MEMINFO * Display detailed memory information
1122 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1124 CONFIG_CMD_MEMTEST * mtest
1125 CONFIG_CMD_MISC Misc functions like sleep etc
1126 CONFIG_CMD_MMC * MMC memory mapped support
1127 CONFIG_CMD_MII * MII utility commands
1128 CONFIG_CMD_MTDPARTS * MTD partition support
1129 CONFIG_CMD_NAND * NAND support
1130 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1131 CONFIG_CMD_NFS NFS support
1132 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1133 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1134 CONFIG_CMD_PCI * pciinfo
1135 CONFIG_CMD_PCMCIA * PCMCIA support
1136 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1138 CONFIG_CMD_PORTIO * Port I/O
1139 CONFIG_CMD_READ * Read raw data from partition
1140 CONFIG_CMD_REGINFO * Register dump
1141 CONFIG_CMD_RUN run command in env variable
1142 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1143 CONFIG_CMD_SAVES * save S record dump
1144 CONFIG_CMD_SCSI * SCSI Support
1145 CONFIG_CMD_SDRAM * print SDRAM configuration information
1146 (requires CONFIG_CMD_I2C)
1147 CONFIG_CMD_SETGETDCR Support for DCR Register access
1149 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1150 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1151 (requires CONFIG_CMD_MEMORY)
1152 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1153 CONFIG_CMD_SOURCE "source" command Support
1154 CONFIG_CMD_SPI * SPI serial bus support
1155 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1156 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1157 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1158 CONFIG_CMD_TIMER * access to the system tick timer
1159 CONFIG_CMD_USB * USB support
1160 CONFIG_CMD_CDP * Cisco Discover Protocol support
1161 CONFIG_CMD_MFSL * Microblaze FSL support
1162 CONFIG_CMD_XIMG Load part of Multi Image
1163 CONFIG_CMD_UUID * Generate random UUID or GUID string
1165 EXAMPLE: If you want all functions except of network
1166 support you can write:
1168 #include "config_cmd_all.h"
1169 #undef CONFIG_CMD_NET
1172 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1174 Note: Don't enable the "icache" and "dcache" commands
1175 (configuration option CONFIG_CMD_CACHE) unless you know
1176 what you (and your U-Boot users) are doing. Data
1177 cache cannot be enabled on systems like the 8xx or
1178 8260 (where accesses to the IMMR region must be
1179 uncached), and it cannot be disabled on all other
1180 systems where we (mis-) use the data cache to hold an
1181 initial stack and some data.
1184 XXX - this list needs to get updated!
1186 - Regular expression support:
1188 If this variable is defined, U-Boot is linked against
1189 the SLRE (Super Light Regular Expression) library,
1190 which adds regex support to some commands, as for
1191 example "env grep" and "setexpr".
1195 If this variable is defined, U-Boot will use a device tree
1196 to configure its devices, instead of relying on statically
1197 compiled #defines in the board file. This option is
1198 experimental and only available on a few boards. The device
1199 tree is available in the global data as gd->fdt_blob.
1201 U-Boot needs to get its device tree from somewhere. This can
1202 be done using one of the two options below:
1205 If this variable is defined, U-Boot will embed a device tree
1206 binary in its image. This device tree file should be in the
1207 board directory and called <soc>-<board>.dts. The binary file
1208 is then picked up in board_init_f() and made available through
1209 the global data structure as gd->blob.
1212 If this variable is defined, U-Boot will build a device tree
1213 binary. It will be called u-boot.dtb. Architecture-specific
1214 code will locate it at run-time. Generally this works by:
1216 cat u-boot.bin u-boot.dtb >image.bin
1218 and in fact, U-Boot does this for you, creating a file called
1219 u-boot-dtb.bin which is useful in the common case. You can
1220 still use the individual files if you need something more
1225 If this variable is defined, it enables watchdog
1226 support for the SoC. There must be support in the SoC
1227 specific code for a watchdog. For the 8xx and 8260
1228 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1229 register. When supported for a specific SoC is
1230 available, then no further board specific code should
1231 be needed to use it.
1234 When using a watchdog circuitry external to the used
1235 SoC, then define this variable and provide board
1236 specific code for the "hw_watchdog_reset" function.
1238 CONFIG_AT91_HW_WDT_TIMEOUT
1239 specify the timeout in seconds. default 2 seconds.
1242 CONFIG_VERSION_VARIABLE
1243 If this variable is defined, an environment variable
1244 named "ver" is created by U-Boot showing the U-Boot
1245 version as printed by the "version" command.
1246 Any change to this variable will be reverted at the
1251 When CONFIG_CMD_DATE is selected, the type of the RTC
1252 has to be selected, too. Define exactly one of the
1255 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1256 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1257 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1258 CONFIG_RTC_MC146818 - use MC146818 RTC
1259 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1260 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1261 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1262 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1263 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1264 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1265 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1266 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1267 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1270 Note that if the RTC uses I2C, then the I2C interface
1271 must also be configured. See I2C Support, below.
1274 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1276 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1277 chip-ngpio pairs that tell the PCA953X driver the number of
1278 pins supported by a particular chip.
1280 Note that if the GPIO device uses I2C, then the I2C interface
1281 must also be configured. See I2C Support, below.
1284 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1285 accesses and can checksum them or write a list of them out
1286 to memory. See the 'iotrace' command for details. This is
1287 useful for testing device drivers since it can confirm that
1288 the driver behaves the same way before and after a code
1289 change. Currently this is supported on sandbox and arm. To
1290 add support for your architecture, add '#include <iotrace.h>'
1291 to the bottom of arch/<arch>/include/asm/io.h and test.
1293 Example output from the 'iotrace stats' command is below.
1294 Note that if the trace buffer is exhausted, the checksum will
1295 still continue to operate.
1298 Start: 10000000 (buffer start address)
1299 Size: 00010000 (buffer size)
1300 Offset: 00000120 (current buffer offset)
1301 Output: 10000120 (start + offset)
1302 Count: 00000018 (number of trace records)
1303 CRC32: 9526fb66 (CRC32 of all trace records)
1305 - Timestamp Support:
1307 When CONFIG_TIMESTAMP is selected, the timestamp
1308 (date and time) of an image is printed by image
1309 commands like bootm or iminfo. This option is
1310 automatically enabled when you select CONFIG_CMD_DATE .
1312 - Partition Labels (disklabels) Supported:
1313 Zero or more of the following:
1314 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1315 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1316 Intel architecture, USB sticks, etc.
1317 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1318 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1319 bootloader. Note 2TB partition limit; see
1321 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1323 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1324 CONFIG_CMD_SCSI) you must configure support for at
1325 least one non-MTD partition type as well.
1328 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1329 board configurations files but used nowhere!
1331 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1332 be performed by calling the function
1333 ide_set_reset(int reset)
1334 which has to be defined in a board specific file
1339 Set this to enable ATAPI support.
1344 Set this to enable support for disks larger than 137GB
1345 Also look at CONFIG_SYS_64BIT_LBA.
1346 Whithout these , LBA48 support uses 32bit variables and will 'only'
1347 support disks up to 2.1TB.
1349 CONFIG_SYS_64BIT_LBA:
1350 When enabled, makes the IDE subsystem use 64bit sector addresses.
1354 At the moment only there is only support for the
1355 SYM53C8XX SCSI controller; define
1356 CONFIG_SCSI_SYM53C8XX to enable it.
1358 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1359 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1360 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1361 maximum numbers of LUNs, SCSI ID's and target
1363 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1365 The environment variable 'scsidevs' is set to the number of
1366 SCSI devices found during the last scan.
1368 - NETWORK Support (PCI):
1370 Support for Intel 8254x/8257x gigabit chips.
1373 Utility code for direct access to the SPI bus on Intel 8257x.
1374 This does not do anything useful unless you set at least one
1375 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1377 CONFIG_E1000_SPI_GENERIC
1378 Allow generic access to the SPI bus on the Intel 8257x, for
1379 example with the "sspi" command.
1382 Management command for E1000 devices. When used on devices
1383 with SPI support you can reprogram the EEPROM from U-Boot.
1385 CONFIG_E1000_FALLBACK_MAC
1386 default MAC for empty EEPROM after production.
1389 Support for Intel 82557/82559/82559ER chips.
1390 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1391 write routine for first time initialisation.
1394 Support for Digital 2114x chips.
1395 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1396 modem chip initialisation (KS8761/QS6611).
1399 Support for National dp83815 chips.
1402 Support for National dp8382[01] gigabit chips.
1404 - NETWORK Support (other):
1406 CONFIG_DRIVER_AT91EMAC
1407 Support for AT91RM9200 EMAC.
1410 Define this to use reduced MII inteface
1412 CONFIG_DRIVER_AT91EMAC_QUIET
1413 If this defined, the driver is quiet.
1414 The driver doen't show link status messages.
1416 CONFIG_CALXEDA_XGMAC
1417 Support for the Calxeda XGMAC device
1420 Support for SMSC's LAN91C96 chips.
1422 CONFIG_LAN91C96_BASE
1423 Define this to hold the physical address
1424 of the LAN91C96's I/O space
1426 CONFIG_LAN91C96_USE_32_BIT
1427 Define this to enable 32 bit addressing
1430 Support for SMSC's LAN91C111 chip
1432 CONFIG_SMC91111_BASE
1433 Define this to hold the physical address
1434 of the device (I/O space)
1436 CONFIG_SMC_USE_32_BIT
1437 Define this if data bus is 32 bits
1439 CONFIG_SMC_USE_IOFUNCS
1440 Define this to use i/o functions instead of macros
1441 (some hardware wont work with macros)
1443 CONFIG_DRIVER_TI_EMAC
1444 Support for davinci emac
1446 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1447 Define this if you have more then 3 PHYs.
1450 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1452 CONFIG_FTGMAC100_EGIGA
1453 Define this to use GE link update with gigabit PHY.
1454 Define this if FTGMAC100 is connected to gigabit PHY.
1455 If your system has 10/100 PHY only, it might not occur
1456 wrong behavior. Because PHY usually return timeout or
1457 useless data when polling gigabit status and gigabit
1458 control registers. This behavior won't affect the
1459 correctnessof 10/100 link speed update.
1462 Support for SMSC's LAN911x and LAN921x chips
1465 Define this to hold the physical address
1466 of the device (I/O space)
1468 CONFIG_SMC911X_32_BIT
1469 Define this if data bus is 32 bits
1471 CONFIG_SMC911X_16_BIT
1472 Define this if data bus is 16 bits. If your processor
1473 automatically converts one 32 bit word to two 16 bit
1474 words you may also try CONFIG_SMC911X_32_BIT.
1477 Support for Renesas on-chip Ethernet controller
1479 CONFIG_SH_ETHER_USE_PORT
1480 Define the number of ports to be used
1482 CONFIG_SH_ETHER_PHY_ADDR
1483 Define the ETH PHY's address
1485 CONFIG_SH_ETHER_CACHE_WRITEBACK
1486 If this option is set, the driver enables cache flush.
1490 Support for PWM modul on the imx6.
1494 Support TPM devices.
1497 Support for i2c bus TPM devices. Only one device
1498 per system is supported at this time.
1500 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1501 Define the the i2c bus number for the TPM device
1503 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1504 Define the TPM's address on the i2c bus
1506 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1507 Define the burst count bytes upper limit
1509 CONFIG_TPM_ATMEL_TWI
1510 Support for Atmel TWI TPM device. Requires I2C support.
1513 Support for generic parallel port TPM devices. Only one device
1514 per system is supported at this time.
1516 CONFIG_TPM_TIS_BASE_ADDRESS
1517 Base address where the generic TPM device is mapped
1518 to. Contemporary x86 systems usually map it at
1522 Add tpm monitor functions.
1523 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1524 provides monitor access to authorized functions.
1527 Define this to enable the TPM support library which provides
1528 functional interfaces to some TPM commands.
1529 Requires support for a TPM device.
1531 CONFIG_TPM_AUTH_SESSIONS
1532 Define this to enable authorized functions in the TPM library.
1533 Requires CONFIG_TPM and CONFIG_SHA1.
1536 At the moment only the UHCI host controller is
1537 supported (PIP405, MIP405, MPC5200); define
1538 CONFIG_USB_UHCI to enable it.
1539 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1540 and define CONFIG_USB_STORAGE to enable the USB
1543 Supported are USB Keyboards and USB Floppy drives
1545 MPC5200 USB requires additional defines:
1547 for 528 MHz Clock: 0x0001bbbb
1551 for differential drivers: 0x00001000
1552 for single ended drivers: 0x00005000
1553 for differential drivers on PSC3: 0x00000100
1554 for single ended drivers on PSC3: 0x00004100
1555 CONFIG_SYS_USB_EVENT_POLL
1556 May be defined to allow interrupt polling
1557 instead of using asynchronous interrupts
1559 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1560 txfilltuning field in the EHCI controller on reset.
1562 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1563 HW module registers.
1566 Define the below if you wish to use the USB console.
1567 Once firmware is rebuilt from a serial console issue the
1568 command "setenv stdin usbtty; setenv stdout usbtty" and
1569 attach your USB cable. The Unix command "dmesg" should print
1570 it has found a new device. The environment variable usbtty
1571 can be set to gserial or cdc_acm to enable your device to
1572 appear to a USB host as a Linux gserial device or a
1573 Common Device Class Abstract Control Model serial device.
1574 If you select usbtty = gserial you should be able to enumerate
1576 # modprobe usbserial vendor=0xVendorID product=0xProductID
1577 else if using cdc_acm, simply setting the environment
1578 variable usbtty to be cdc_acm should suffice. The following
1579 might be defined in YourBoardName.h
1582 Define this to build a UDC device
1585 Define this to have a tty type of device available to
1586 talk to the UDC device
1589 Define this to enable the high speed support for usb
1590 device and usbtty. If this feature is enabled, a routine
1591 int is_usbd_high_speed(void)
1592 also needs to be defined by the driver to dynamically poll
1593 whether the enumeration has succeded at high speed or full
1596 CONFIG_SYS_CONSOLE_IS_IN_ENV
1597 Define this if you want stdin, stdout &/or stderr to
1601 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1602 Derive USB clock from external clock "blah"
1603 - CONFIG_SYS_USB_EXTC_CLK 0x02
1605 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1606 Derive USB clock from brgclk
1607 - CONFIG_SYS_USB_BRG_CLK 0x04
1609 If you have a USB-IF assigned VendorID then you may wish to
1610 define your own vendor specific values either in BoardName.h
1611 or directly in usbd_vendor_info.h. If you don't define
1612 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1613 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1614 should pretend to be a Linux device to it's target host.
1616 CONFIG_USBD_MANUFACTURER
1617 Define this string as the name of your company for
1618 - CONFIG_USBD_MANUFACTURER "my company"
1620 CONFIG_USBD_PRODUCT_NAME
1621 Define this string as the name of your product
1622 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1624 CONFIG_USBD_VENDORID
1625 Define this as your assigned Vendor ID from the USB
1626 Implementors Forum. This *must* be a genuine Vendor ID
1627 to avoid polluting the USB namespace.
1628 - CONFIG_USBD_VENDORID 0xFFFF
1630 CONFIG_USBD_PRODUCTID
1631 Define this as the unique Product ID
1633 - CONFIG_USBD_PRODUCTID 0xFFFF
1635 - ULPI Layer Support:
1636 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1637 the generic ULPI layer. The generic layer accesses the ULPI PHY
1638 via the platform viewport, so you need both the genric layer and
1639 the viewport enabled. Currently only Chipidea/ARC based
1640 viewport is supported.
1641 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1642 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1643 If your ULPI phy needs a different reference clock than the
1644 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1645 the appropriate value in Hz.
1648 The MMC controller on the Intel PXA is supported. To
1649 enable this define CONFIG_MMC. The MMC can be
1650 accessed from the boot prompt by mapping the device
1651 to physical memory similar to flash. Command line is
1652 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1653 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1656 Support for Renesas on-chip MMCIF controller
1658 CONFIG_SH_MMCIF_ADDR
1659 Define the base address of MMCIF registers
1662 Define the clock frequency for MMCIF
1665 Enable the generic MMC driver
1667 CONFIG_SUPPORT_EMMC_BOOT
1668 Enable some additional features of the eMMC boot partitions.
1670 CONFIG_SUPPORT_EMMC_RPMB
1671 Enable the commands for reading, writing and programming the
1672 key for the Replay Protection Memory Block partition in eMMC.
1674 - USB Device Firmware Update (DFU) class support:
1676 This enables the USB portion of the DFU USB class
1679 This enables the command "dfu" which is used to have
1680 U-Boot create a DFU class device via USB. This command
1681 requires that the "dfu_alt_info" environment variable be
1682 set and define the alt settings to expose to the host.
1685 This enables support for exposing (e)MMC devices via DFU.
1688 This enables support for exposing NAND devices via DFU.
1691 This enables support for exposing RAM via DFU.
1692 Note: DFU spec refer to non-volatile memory usage, but
1693 allow usages beyond the scope of spec - here RAM usage,
1694 one that would help mostly the developer.
1696 CONFIG_SYS_DFU_DATA_BUF_SIZE
1697 Dfu transfer uses a buffer before writing data to the
1698 raw storage device. Make the size (in bytes) of this buffer
1699 configurable. The size of this buffer is also configurable
1700 through the "dfu_bufsiz" environment variable.
1702 CONFIG_SYS_DFU_MAX_FILE_SIZE
1703 When updating files rather than the raw storage device,
1704 we use a static buffer to copy the file into and then write
1705 the buffer once we've been given the whole file. Define
1706 this to the maximum filesize (in bytes) for the buffer.
1707 Default is 4 MiB if undefined.
1709 DFU_DEFAULT_POLL_TIMEOUT
1710 Poll timeout [ms], is the timeout a device can send to the
1711 host. The host must wait for this timeout before sending
1712 a subsequent DFU_GET_STATUS request to the device.
1714 DFU_MANIFEST_POLL_TIMEOUT
1715 Poll timeout [ms], which the device sends to the host when
1716 entering dfuMANIFEST state. Host waits this timeout, before
1717 sending again an USB request to the device.
1719 - USB Device Android Fastboot support:
1721 This enables the command "fastboot" which enables the Android
1722 fastboot mode for the platform's USB device. Fastboot is a USB
1723 protocol for downloading images, flashing and device control
1724 used on Android devices.
1725 See doc/README.android-fastboot for more information.
1727 CONFIG_ANDROID_BOOT_IMAGE
1728 This enables support for booting images which use the Android
1729 image format header.
1731 CONFIG_USB_FASTBOOT_BUF_ADDR
1732 The fastboot protocol requires a large memory buffer for
1733 downloads. Define this to the starting RAM address to use for
1736 CONFIG_USB_FASTBOOT_BUF_SIZE
1737 The fastboot protocol requires a large memory buffer for
1738 downloads. This buffer should be as large as possible for a
1739 platform. Define this to the size available RAM for fastboot.
1741 CONFIG_FASTBOOT_FLASH
1742 The fastboot protocol includes a "flash" command for writing
1743 the downloaded image to a non-volatile storage device. Define
1744 this to enable the "fastboot flash" command.
1746 CONFIG_FASTBOOT_FLASH_MMC_DEV
1747 The fastboot "flash" command requires additional information
1748 regarding the non-volatile storage device. Define this to
1749 the eMMC device that fastboot should use to store the image.
1751 CONFIG_FASTBOOT_GPT_NAME
1752 The fastboot "flash" command supports writing the downloaded
1753 image to the Protective MBR and the Primary GUID Partition
1754 Table. (Additionally, this downloaded image is post-processed
1755 to generate and write the Backup GUID Partition Table.)
1756 This occurs when the specified "partition name" on the
1757 "fastboot flash" command line matches this value.
1758 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1760 - Journaling Flash filesystem support:
1761 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1762 CONFIG_JFFS2_NAND_DEV
1763 Define these for a default partition on a NAND device
1765 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1766 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1767 Define these for a default partition on a NOR device
1769 CONFIG_SYS_JFFS_CUSTOM_PART
1770 Define this to create an own partition. You have to provide a
1771 function struct part_info* jffs2_part_info(int part_num)
1773 If you define only one JFFS2 partition you may also want to
1774 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1775 to disable the command chpart. This is the default when you
1776 have not defined a custom partition
1778 - FAT(File Allocation Table) filesystem write function support:
1781 Define this to enable support for saving memory data as a
1782 file in FAT formatted partition.
1784 This will also enable the command "fatwrite" enabling the
1785 user to write files to FAT.
1787 CBFS (Coreboot Filesystem) support
1790 Define this to enable support for reading from a Coreboot
1791 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1794 - FAT(File Allocation Table) filesystem cluster size:
1795 CONFIG_FS_FAT_MAX_CLUSTSIZE
1797 Define the max cluster size for fat operations else
1798 a default value of 65536 will be defined.
1803 Define this to enable standard (PC-Style) keyboard
1807 Standard PC keyboard driver with US (is default) and
1808 GERMAN key layout (switch via environment 'keymap=de') support.
1809 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1810 for cfb_console. Supports cursor blinking.
1813 Enables a Chrome OS keyboard using the CROS_EC interface.
1814 This uses CROS_EC to communicate with a second microcontroller
1815 which provides key scans on request.
1820 Define this to enable video support (for output to
1823 CONFIG_VIDEO_CT69000
1825 Enable Chips & Technologies 69000 Video chip
1827 CONFIG_VIDEO_SMI_LYNXEM
1828 Enable Silicon Motion SMI 712/710/810 Video chip. The
1829 video output is selected via environment 'videoout'
1830 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1833 For the CT69000 and SMI_LYNXEM drivers, videomode is
1834 selected via environment 'videomode'. Two different ways
1836 - "videomode=num" 'num' is a standard LiLo mode numbers.
1837 Following standard modes are supported (* is default):
1839 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1840 -------------+---------------------------------------------
1841 8 bits | 0x301* 0x303 0x305 0x161 0x307
1842 15 bits | 0x310 0x313 0x316 0x162 0x319
1843 16 bits | 0x311 0x314 0x317 0x163 0x31A
1844 24 bits | 0x312 0x315 0x318 ? 0x31B
1845 -------------+---------------------------------------------
1846 (i.e. setenv videomode 317; saveenv; reset;)
1848 - "videomode=bootargs" all the video parameters are parsed
1849 from the bootargs. (See drivers/video/videomodes.c)
1852 CONFIG_VIDEO_SED13806
1853 Enable Epson SED13806 driver. This driver supports 8bpp
1854 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1855 or CONFIG_VIDEO_SED13806_16BPP
1858 Enable the Freescale DIU video driver. Reference boards for
1859 SOCs that have a DIU should define this macro to enable DIU
1860 support, and should also define these other macros:
1866 CONFIG_VIDEO_SW_CURSOR
1867 CONFIG_VGA_AS_SINGLE_DEVICE
1869 CONFIG_VIDEO_BMP_LOGO
1871 The DIU driver will look for the 'video-mode' environment
1872 variable, and if defined, enable the DIU as a console during
1873 boot. See the documentation file README.video for a
1874 description of this variable.
1878 Enable the VGA video / BIOS for x86. The alternative if you
1879 are using coreboot is to use the coreboot frame buffer
1886 Define this to enable a custom keyboard support.
1887 This simply calls drv_keyboard_init() which must be
1888 defined in your board-specific files.
1889 The only board using this so far is RBC823.
1891 - LCD Support: CONFIG_LCD
1893 Define this to enable LCD support (for output to LCD
1894 display); also select one of the supported displays
1895 by defining one of these:
1899 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1901 CONFIG_NEC_NL6448AC33:
1903 NEC NL6448AC33-18. Active, color, single scan.
1905 CONFIG_NEC_NL6448BC20
1907 NEC NL6448BC20-08. 6.5", 640x480.
1908 Active, color, single scan.
1910 CONFIG_NEC_NL6448BC33_54
1912 NEC NL6448BC33-54. 10.4", 640x480.
1913 Active, color, single scan.
1917 Sharp 320x240. Active, color, single scan.
1918 It isn't 16x9, and I am not sure what it is.
1920 CONFIG_SHARP_LQ64D341
1922 Sharp LQ64D341 display, 640x480.
1923 Active, color, single scan.
1927 HLD1045 display, 640x480.
1928 Active, color, single scan.
1932 Optrex CBL50840-2 NF-FW 99 22 M5
1934 Hitachi LMG6912RPFC-00T
1938 320x240. Black & white.
1940 Normally display is black on white background; define
1941 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1943 CONFIG_LCD_ALIGNMENT
1945 Normally the LCD is page-aligned (typically 4KB). If this is
1946 defined then the LCD will be aligned to this value instead.
1947 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1948 here, since it is cheaper to change data cache settings on
1949 a per-section basis.
1951 CONFIG_CONSOLE_SCROLL_LINES
1953 When the console need to be scrolled, this is the number of
1954 lines to scroll by. It defaults to 1. Increasing this makes
1955 the console jump but can help speed up operation when scrolling
1960 Sometimes, for example if the display is mounted in portrait
1961 mode or even if it's mounted landscape but rotated by 180degree,
1962 we need to rotate our content of the display relative to the
1963 framebuffer, so that user can read the messages which are
1965 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1966 initialized with a given rotation from "vl_rot" out of
1967 "vidinfo_t" which is provided by the board specific code.
1968 The value for vl_rot is coded as following (matching to
1969 fbcon=rotate:<n> linux-kernel commandline):
1970 0 = no rotation respectively 0 degree
1971 1 = 90 degree rotation
1972 2 = 180 degree rotation
1973 3 = 270 degree rotation
1975 If CONFIG_LCD_ROTATION is not defined, the console will be
1976 initialized with 0degree rotation.
1980 Support drawing of RLE8-compressed bitmaps on the LCD.
1984 Enables an 'i2c edid' command which can read EDID
1985 information over I2C from an attached LCD display.
1987 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1989 If this option is set, the environment is checked for
1990 a variable "splashimage". If found, the usual display
1991 of logo, copyright and system information on the LCD
1992 is suppressed and the BMP image at the address
1993 specified in "splashimage" is loaded instead. The
1994 console is redirected to the "nulldev", too. This
1995 allows for a "silent" boot where a splash screen is
1996 loaded very quickly after power-on.
1998 CONFIG_SPLASHIMAGE_GUARD
2000 If this option is set, then U-Boot will prevent the environment
2001 variable "splashimage" from being set to a problematic address
2002 (see README.displaying-bmps).
2003 This option is useful for targets where, due to alignment
2004 restrictions, an improperly aligned BMP image will cause a data
2005 abort. If you think you will not have problems with unaligned
2006 accesses (for example because your toolchain prevents them)
2007 there is no need to set this option.
2009 CONFIG_SPLASH_SCREEN_ALIGN
2011 If this option is set the splash image can be freely positioned
2012 on the screen. Environment variable "splashpos" specifies the
2013 position as "x,y". If a positive number is given it is used as
2014 number of pixel from left/top. If a negative number is given it
2015 is used as number of pixel from right/bottom. You can also
2016 specify 'm' for centering the image.
2019 setenv splashpos m,m
2020 => image at center of screen
2022 setenv splashpos 30,20
2023 => image at x = 30 and y = 20
2025 setenv splashpos -10,m
2026 => vertically centered image
2027 at x = dspWidth - bmpWidth - 9
2029 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2031 If this option is set, additionally to standard BMP
2032 images, gzipped BMP images can be displayed via the
2033 splashscreen support or the bmp command.
2035 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2037 If this option is set, 8-bit RLE compressed BMP images
2038 can be displayed via the splashscreen support or the
2041 - Do compressing for memory range:
2044 If this option is set, it would use zlib deflate method
2045 to compress the specified memory at its best effort.
2047 - Compression support:
2050 Enabled by default to support gzip compressed images.
2054 If this option is set, support for bzip2 compressed
2055 images is included. If not, only uncompressed and gzip
2056 compressed images are supported.
2058 NOTE: the bzip2 algorithm requires a lot of RAM, so
2059 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2064 If this option is set, support for lzma compressed
2067 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2068 requires an amount of dynamic memory that is given by the
2071 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2073 Where lc and lp stand for, respectively, Literal context bits
2074 and Literal pos bits.
2076 This value is upper-bounded by 14MB in the worst case. Anyway,
2077 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2078 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2079 a very small buffer.
2081 Use the lzmainfo tool to determinate the lc and lp values and
2082 then calculate the amount of needed dynamic memory (ensuring
2083 the appropriate CONFIG_SYS_MALLOC_LEN value).
2087 If this option is set, support for LZO compressed images
2093 The address of PHY on MII bus.
2095 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2097 The clock frequency of the MII bus
2101 If this option is set, support for speed/duplex
2102 detection of gigabit PHY is included.
2104 CONFIG_PHY_RESET_DELAY
2106 Some PHY like Intel LXT971A need extra delay after
2107 reset before any MII register access is possible.
2108 For such PHY, set this option to the usec delay
2109 required. (minimum 300usec for LXT971A)
2111 CONFIG_PHY_CMD_DELAY (ppc4xx)
2113 Some PHY like Intel LXT971A need extra delay after
2114 command issued before MII status register can be read
2124 Define a default value for Ethernet address to use
2125 for the respective Ethernet interface, in case this
2126 is not determined automatically.
2131 Define a default value for the IP address to use for
2132 the default Ethernet interface, in case this is not
2133 determined through e.g. bootp.
2134 (Environment variable "ipaddr")
2136 - Server IP address:
2139 Defines a default value for the IP address of a TFTP
2140 server to contact when using the "tftboot" command.
2141 (Environment variable "serverip")
2143 CONFIG_KEEP_SERVERADDR
2145 Keeps the server's MAC address, in the env 'serveraddr'
2146 for passing to bootargs (like Linux's netconsole option)
2148 - Gateway IP address:
2151 Defines a default value for the IP address of the
2152 default router where packets to other networks are
2154 (Environment variable "gatewayip")
2159 Defines a default value for the subnet mask (or
2160 routing prefix) which is used to determine if an IP
2161 address belongs to the local subnet or needs to be
2162 forwarded through a router.
2163 (Environment variable "netmask")
2165 - Multicast TFTP Mode:
2168 Defines whether you want to support multicast TFTP as per
2169 rfc-2090; for example to work with atftp. Lets lots of targets
2170 tftp down the same boot image concurrently. Note: the Ethernet
2171 driver in use must provide a function: mcast() to join/leave a
2174 - BOOTP Recovery Mode:
2175 CONFIG_BOOTP_RANDOM_DELAY
2177 If you have many targets in a network that try to
2178 boot using BOOTP, you may want to avoid that all
2179 systems send out BOOTP requests at precisely the same
2180 moment (which would happen for instance at recovery
2181 from a power failure, when all systems will try to
2182 boot, thus flooding the BOOTP server. Defining
2183 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2184 inserted before sending out BOOTP requests. The
2185 following delays are inserted then:
2187 1st BOOTP request: delay 0 ... 1 sec
2188 2nd BOOTP request: delay 0 ... 2 sec
2189 3rd BOOTP request: delay 0 ... 4 sec
2191 BOOTP requests: delay 0 ... 8 sec
2193 CONFIG_BOOTP_ID_CACHE_SIZE
2195 BOOTP packets are uniquely identified using a 32-bit ID. The
2196 server will copy the ID from client requests to responses and
2197 U-Boot will use this to determine if it is the destination of
2198 an incoming response. Some servers will check that addresses
2199 aren't in use before handing them out (usually using an ARP
2200 ping) and therefore take up to a few hundred milliseconds to
2201 respond. Network congestion may also influence the time it
2202 takes for a response to make it back to the client. If that
2203 time is too long, U-Boot will retransmit requests. In order
2204 to allow earlier responses to still be accepted after these
2205 retransmissions, U-Boot's BOOTP client keeps a small cache of
2206 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2207 cache. The default is to keep IDs for up to four outstanding
2208 requests. Increasing this will allow U-Boot to accept offers
2209 from a BOOTP client in networks with unusually high latency.
2211 - DHCP Advanced Options:
2212 You can fine tune the DHCP functionality by defining
2213 CONFIG_BOOTP_* symbols:
2215 CONFIG_BOOTP_SUBNETMASK
2216 CONFIG_BOOTP_GATEWAY
2217 CONFIG_BOOTP_HOSTNAME
2218 CONFIG_BOOTP_NISDOMAIN
2219 CONFIG_BOOTP_BOOTPATH
2220 CONFIG_BOOTP_BOOTFILESIZE
2223 CONFIG_BOOTP_SEND_HOSTNAME
2224 CONFIG_BOOTP_NTPSERVER
2225 CONFIG_BOOTP_TIMEOFFSET
2226 CONFIG_BOOTP_VENDOREX
2227 CONFIG_BOOTP_MAY_FAIL
2229 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2230 environment variable, not the BOOTP server.
2232 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2233 after the configured retry count, the call will fail
2234 instead of starting over. This can be used to fail over
2235 to Link-local IP address configuration if the DHCP server
2238 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2239 serverip from a DHCP server, it is possible that more
2240 than one DNS serverip is offered to the client.
2241 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2242 serverip will be stored in the additional environment
2243 variable "dnsip2". The first DNS serverip is always
2244 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2247 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2248 to do a dynamic update of a DNS server. To do this, they
2249 need the hostname of the DHCP requester.
2250 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2251 of the "hostname" environment variable is passed as
2252 option 12 to the DHCP server.
2254 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2256 A 32bit value in microseconds for a delay between
2257 receiving a "DHCP Offer" and sending the "DHCP Request".
2258 This fixes a problem with certain DHCP servers that don't
2259 respond 100% of the time to a "DHCP request". E.g. On an
2260 AT91RM9200 processor running at 180MHz, this delay needed
2261 to be *at least* 15,000 usec before a Windows Server 2003
2262 DHCP server would reply 100% of the time. I recommend at
2263 least 50,000 usec to be safe. The alternative is to hope
2264 that one of the retries will be successful but note that
2265 the DHCP timeout and retry process takes a longer than
2268 - Link-local IP address negotiation:
2269 Negotiate with other link-local clients on the local network
2270 for an address that doesn't require explicit configuration.
2271 This is especially useful if a DHCP server cannot be guaranteed
2272 to exist in all environments that the device must operate.
2274 See doc/README.link-local for more information.
2277 CONFIG_CDP_DEVICE_ID
2279 The device id used in CDP trigger frames.
2281 CONFIG_CDP_DEVICE_ID_PREFIX
2283 A two character string which is prefixed to the MAC address
2288 A printf format string which contains the ascii name of
2289 the port. Normally is set to "eth%d" which sets
2290 eth0 for the first Ethernet, eth1 for the second etc.
2292 CONFIG_CDP_CAPABILITIES
2294 A 32bit integer which indicates the device capabilities;
2295 0x00000010 for a normal host which does not forwards.
2299 An ascii string containing the version of the software.
2303 An ascii string containing the name of the platform.
2307 A 32bit integer sent on the trigger.
2309 CONFIG_CDP_POWER_CONSUMPTION
2311 A 16bit integer containing the power consumption of the
2312 device in .1 of milliwatts.
2314 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2316 A byte containing the id of the VLAN.
2318 - Status LED: CONFIG_STATUS_LED
2320 Several configurations allow to display the current
2321 status using a LED. For instance, the LED will blink
2322 fast while running U-Boot code, stop blinking as
2323 soon as a reply to a BOOTP request was received, and
2324 start blinking slow once the Linux kernel is running
2325 (supported by a status LED driver in the Linux
2326 kernel). Defining CONFIG_STATUS_LED enables this
2332 The status LED can be connected to a GPIO pin.
2333 In such cases, the gpio_led driver can be used as a
2334 status LED backend implementation. Define CONFIG_GPIO_LED
2335 to include the gpio_led driver in the U-Boot binary.
2337 CONFIG_GPIO_LED_INVERTED_TABLE
2338 Some GPIO connected LEDs may have inverted polarity in which
2339 case the GPIO high value corresponds to LED off state and
2340 GPIO low value corresponds to LED on state.
2341 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2342 with a list of GPIO LEDs that have inverted polarity.
2344 - CAN Support: CONFIG_CAN_DRIVER
2346 Defining CONFIG_CAN_DRIVER enables CAN driver support
2347 on those systems that support this (optional)
2348 feature, like the TQM8xxL modules.
2350 - I2C Support: CONFIG_SYS_I2C
2352 This enable the NEW i2c subsystem, and will allow you to use
2353 i2c commands at the u-boot command line (as long as you set
2354 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2355 based realtime clock chips or other i2c devices. See
2356 common/cmd_i2c.c for a description of the command line
2359 ported i2c driver to the new framework:
2360 - drivers/i2c/soft_i2c.c:
2361 - activate first bus with CONFIG_SYS_I2C_SOFT define
2362 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2363 for defining speed and slave address
2364 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2365 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2366 for defining speed and slave address
2367 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2368 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2369 for defining speed and slave address
2370 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2371 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2372 for defining speed and slave address
2374 - drivers/i2c/fsl_i2c.c:
2375 - activate i2c driver with CONFIG_SYS_I2C_FSL
2376 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2377 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2378 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2380 - If your board supports a second fsl i2c bus, define
2381 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2382 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2383 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2386 - drivers/i2c/tegra_i2c.c:
2387 - activate this driver with CONFIG_SYS_I2C_TEGRA
2388 - This driver adds 4 i2c buses with a fix speed from
2389 100000 and the slave addr 0!
2391 - drivers/i2c/ppc4xx_i2c.c
2392 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2393 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2394 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2396 - drivers/i2c/i2c_mxc.c
2397 - activate this driver with CONFIG_SYS_I2C_MXC
2398 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2399 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2400 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2401 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2402 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2403 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2404 If those defines are not set, default value is 100000
2405 for speed, and 0 for slave.
2406 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2407 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2409 - drivers/i2c/rcar_i2c.c:
2410 - activate this driver with CONFIG_SYS_I2C_RCAR
2411 - This driver adds 4 i2c buses
2413 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2414 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2415 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2416 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2417 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2418 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2419 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2420 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2421 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2423 - drivers/i2c/sh_i2c.c:
2424 - activate this driver with CONFIG_SYS_I2C_SH
2425 - This driver adds from 2 to 5 i2c buses
2427 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2428 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2429 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2430 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2431 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2432 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2433 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2434 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2435 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2436 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2437 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2438 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2439 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2441 - drivers/i2c/omap24xx_i2c.c
2442 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2443 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2444 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2445 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2446 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2447 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2448 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2449 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2450 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2451 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2452 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2454 - drivers/i2c/zynq_i2c.c
2455 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2456 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2457 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2459 - drivers/i2c/s3c24x0_i2c.c:
2460 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2461 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2462 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2463 with a fix speed from 100000 and the slave addr 0!
2465 - drivers/i2c/ihs_i2c.c
2466 - activate this driver with CONFIG_SYS_I2C_IHS
2467 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2468 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2469 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2470 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2471 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2472 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2473 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2474 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2475 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2476 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2477 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2478 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2482 CONFIG_SYS_NUM_I2C_BUSES
2483 Hold the number of i2c buses you want to use. If you
2484 don't use/have i2c muxes on your i2c bus, this
2485 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2488 CONFIG_SYS_I2C_DIRECT_BUS
2489 define this, if you don't use i2c muxes on your hardware.
2490 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2493 CONFIG_SYS_I2C_MAX_HOPS
2494 define how many muxes are maximal consecutively connected
2495 on one i2c bus. If you not use i2c muxes, omit this
2498 CONFIG_SYS_I2C_BUSES
2499 hold a list of buses you want to use, only used if
2500 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2501 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2502 CONFIG_SYS_NUM_I2C_BUSES = 9:
2504 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2505 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2506 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2507 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2508 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2509 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2510 {1, {I2C_NULL_HOP}}, \
2511 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2512 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2516 bus 0 on adapter 0 without a mux
2517 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2518 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2519 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2520 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2521 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2522 bus 6 on adapter 1 without a mux
2523 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2524 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2526 If you do not have i2c muxes on your board, omit this define.
2528 - Legacy I2C Support: CONFIG_HARD_I2C
2530 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2531 provides the following compelling advantages:
2533 - more than one i2c adapter is usable
2534 - approved multibus support
2535 - better i2c mux support
2537 ** Please consider updating your I2C driver now. **
2539 These enable legacy I2C serial bus commands. Defining
2540 CONFIG_HARD_I2C will include the appropriate I2C driver
2541 for the selected CPU.
2543 This will allow you to use i2c commands at the u-boot
2544 command line (as long as you set CONFIG_CMD_I2C in
2545 CONFIG_COMMANDS) and communicate with i2c based realtime
2546 clock chips. See common/cmd_i2c.c for a description of the
2547 command line interface.
2549 CONFIG_HARD_I2C selects a hardware I2C controller.
2551 There are several other quantities that must also be
2552 defined when you define CONFIG_HARD_I2C.
2554 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2555 to be the frequency (in Hz) at which you wish your i2c bus
2556 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2557 the CPU's i2c node address).
2559 Now, the u-boot i2c code for the mpc8xx
2560 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2561 and so its address should therefore be cleared to 0 (See,
2562 eg, MPC823e User's Manual p.16-473). So, set
2563 CONFIG_SYS_I2C_SLAVE to 0.
2565 CONFIG_SYS_I2C_INIT_MPC5XXX
2567 When a board is reset during an i2c bus transfer
2568 chips might think that the current transfer is still
2569 in progress. Reset the slave devices by sending start
2570 commands until the slave device responds.
2572 That's all that's required for CONFIG_HARD_I2C.
2574 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2575 then the following macros need to be defined (examples are
2576 from include/configs/lwmon.h):
2580 (Optional). Any commands necessary to enable the I2C
2581 controller or configure ports.
2583 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2587 (Only for MPC8260 CPU). The I/O port to use (the code
2588 assumes both bits are on the same port). Valid values
2589 are 0..3 for ports A..D.
2593 The code necessary to make the I2C data line active
2594 (driven). If the data line is open collector, this
2597 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2601 The code necessary to make the I2C data line tri-stated
2602 (inactive). If the data line is open collector, this
2605 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2609 Code that returns true if the I2C data line is high,
2612 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2616 If <bit> is true, sets the I2C data line high. If it
2617 is false, it clears it (low).
2619 eg: #define I2C_SDA(bit) \
2620 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2621 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2625 If <bit> is true, sets the I2C clock line high. If it
2626 is false, it clears it (low).
2628 eg: #define I2C_SCL(bit) \
2629 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2630 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2634 This delay is invoked four times per clock cycle so this
2635 controls the rate of data transfer. The data rate thus
2636 is 1 / (I2C_DELAY * 4). Often defined to be something
2639 #define I2C_DELAY udelay(2)
2641 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2643 If your arch supports the generic GPIO framework (asm/gpio.h),
2644 then you may alternatively define the two GPIOs that are to be
2645 used as SCL / SDA. Any of the previous I2C_xxx macros will
2646 have GPIO-based defaults assigned to them as appropriate.
2648 You should define these to the GPIO value as given directly to
2649 the generic GPIO functions.
2651 CONFIG_SYS_I2C_INIT_BOARD
2653 When a board is reset during an i2c bus transfer
2654 chips might think that the current transfer is still
2655 in progress. On some boards it is possible to access
2656 the i2c SCLK line directly, either by using the
2657 processor pin as a GPIO or by having a second pin
2658 connected to the bus. If this option is defined a
2659 custom i2c_init_board() routine in boards/xxx/board.c
2660 is run early in the boot sequence.
2662 CONFIG_SYS_I2C_BOARD_LATE_INIT
2664 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2665 defined a custom i2c_board_late_init() routine in
2666 boards/xxx/board.c is run AFTER the operations in i2c_init()
2667 is completed. This callpoint can be used to unreset i2c bus
2668 using CPU i2c controller register accesses for CPUs whose i2c
2669 controller provide such a method. It is called at the end of
2670 i2c_init() to allow i2c_init operations to setup the i2c bus
2671 controller on the CPU (e.g. setting bus speed & slave address).
2673 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2675 This option enables configuration of bi_iic_fast[] flags
2676 in u-boot bd_info structure based on u-boot environment
2677 variable "i2cfast". (see also i2cfast)
2679 CONFIG_I2C_MULTI_BUS
2681 This option allows the use of multiple I2C buses, each of which
2682 must have a controller. At any point in time, only one bus is
2683 active. To switch to a different bus, use the 'i2c dev' command.
2684 Note that bus numbering is zero-based.
2686 CONFIG_SYS_I2C_NOPROBES
2688 This option specifies a list of I2C devices that will be skipped
2689 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2690 is set, specify a list of bus-device pairs. Otherwise, specify
2691 a 1D array of device addresses
2694 #undef CONFIG_I2C_MULTI_BUS
2695 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2697 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2699 #define CONFIG_I2C_MULTI_BUS
2700 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2702 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2704 CONFIG_SYS_SPD_BUS_NUM
2706 If defined, then this indicates the I2C bus number for DDR SPD.
2707 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2709 CONFIG_SYS_RTC_BUS_NUM
2711 If defined, then this indicates the I2C bus number for the RTC.
2712 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2714 CONFIG_SYS_DTT_BUS_NUM
2716 If defined, then this indicates the I2C bus number for the DTT.
2717 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2719 CONFIG_SYS_I2C_DTT_ADDR:
2721 If defined, specifies the I2C address of the DTT device.
2722 If not defined, then U-Boot uses predefined value for
2723 specified DTT device.
2725 CONFIG_SOFT_I2C_READ_REPEATED_START
2727 defining this will force the i2c_read() function in
2728 the soft_i2c driver to perform an I2C repeated start
2729 between writing the address pointer and reading the
2730 data. If this define is omitted the default behaviour
2731 of doing a stop-start sequence will be used. Most I2C
2732 devices can use either method, but some require one or
2735 - SPI Support: CONFIG_SPI
2737 Enables SPI driver (so far only tested with
2738 SPI EEPROM, also an instance works with Crystal A/D and
2739 D/As on the SACSng board)
2743 Enables the driver for SPI controller on SuperH. Currently
2744 only SH7757 is supported.
2748 Enables extended (16-bit) SPI EEPROM addressing.
2749 (symmetrical to CONFIG_I2C_X)
2753 Enables a software (bit-bang) SPI driver rather than
2754 using hardware support. This is a general purpose
2755 driver that only requires three general I/O port pins
2756 (two outputs, one input) to function. If this is
2757 defined, the board configuration must define several
2758 SPI configuration items (port pins to use, etc). For
2759 an example, see include/configs/sacsng.h.
2763 Enables a hardware SPI driver for general-purpose reads
2764 and writes. As with CONFIG_SOFT_SPI, the board configuration
2765 must define a list of chip-select function pointers.
2766 Currently supported on some MPC8xxx processors. For an
2767 example, see include/configs/mpc8349emds.h.
2771 Enables the driver for the SPI controllers on i.MX and MXC
2772 SoCs. Currently i.MX31/35/51 are supported.
2774 CONFIG_SYS_SPI_MXC_WAIT
2775 Timeout for waiting until spi transfer completed.
2776 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2778 - FPGA Support: CONFIG_FPGA
2780 Enables FPGA subsystem.
2782 CONFIG_FPGA_<vendor>
2784 Enables support for specific chip vendors.
2787 CONFIG_FPGA_<family>
2789 Enables support for FPGA family.
2790 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2794 Specify the number of FPGA devices to support.
2796 CONFIG_CMD_FPGA_LOADMK
2798 Enable support for fpga loadmk command
2800 CONFIG_CMD_FPGA_LOADP
2802 Enable support for fpga loadp command - load partial bitstream
2804 CONFIG_CMD_FPGA_LOADBP
2806 Enable support for fpga loadbp command - load partial bitstream
2809 CONFIG_SYS_FPGA_PROG_FEEDBACK
2811 Enable printing of hash marks during FPGA configuration.
2813 CONFIG_SYS_FPGA_CHECK_BUSY
2815 Enable checks on FPGA configuration interface busy
2816 status by the configuration function. This option
2817 will require a board or device specific function to
2822 If defined, a function that provides delays in the FPGA
2823 configuration driver.
2825 CONFIG_SYS_FPGA_CHECK_CTRLC
2826 Allow Control-C to interrupt FPGA configuration
2828 CONFIG_SYS_FPGA_CHECK_ERROR
2830 Check for configuration errors during FPGA bitfile
2831 loading. For example, abort during Virtex II
2832 configuration if the INIT_B line goes low (which
2833 indicated a CRC error).
2835 CONFIG_SYS_FPGA_WAIT_INIT
2837 Maximum time to wait for the INIT_B line to de-assert
2838 after PROB_B has been de-asserted during a Virtex II
2839 FPGA configuration sequence. The default time is 500
2842 CONFIG_SYS_FPGA_WAIT_BUSY
2844 Maximum time to wait for BUSY to de-assert during
2845 Virtex II FPGA configuration. The default is 5 ms.
2847 CONFIG_SYS_FPGA_WAIT_CONFIG
2849 Time to wait after FPGA configuration. The default is
2852 - Configuration Management:
2855 Some SoCs need special image types (e.g. U-Boot binary
2856 with a special header) as build targets. By defining
2857 CONFIG_BUILD_TARGET in the SoC / board header, this
2858 special image will be automatically built upon calling
2863 If defined, this string will be added to the U-Boot
2864 version information (U_BOOT_VERSION)
2866 - Vendor Parameter Protection:
2868 U-Boot considers the values of the environment
2869 variables "serial#" (Board Serial Number) and
2870 "ethaddr" (Ethernet Address) to be parameters that
2871 are set once by the board vendor / manufacturer, and
2872 protects these variables from casual modification by
2873 the user. Once set, these variables are read-only,
2874 and write or delete attempts are rejected. You can
2875 change this behaviour:
2877 If CONFIG_ENV_OVERWRITE is #defined in your config
2878 file, the write protection for vendor parameters is
2879 completely disabled. Anybody can change or delete
2882 Alternatively, if you #define _both_ CONFIG_ETHADDR
2883 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2884 Ethernet address is installed in the environment,
2885 which can be changed exactly ONCE by the user. [The
2886 serial# is unaffected by this, i. e. it remains
2889 The same can be accomplished in a more flexible way
2890 for any variable by configuring the type of access
2891 to allow for those variables in the ".flags" variable
2892 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2897 Define this variable to enable the reservation of
2898 "protected RAM", i. e. RAM which is not overwritten
2899 by U-Boot. Define CONFIG_PRAM to hold the number of
2900 kB you want to reserve for pRAM. You can overwrite
2901 this default value by defining an environment
2902 variable "pram" to the number of kB you want to
2903 reserve. Note that the board info structure will
2904 still show the full amount of RAM. If pRAM is
2905 reserved, a new environment variable "mem" will
2906 automatically be defined to hold the amount of
2907 remaining RAM in a form that can be passed as boot
2908 argument to Linux, for instance like that:
2910 setenv bootargs ... mem=\${mem}
2913 This way you can tell Linux not to use this memory,
2914 either, which results in a memory region that will
2915 not be affected by reboots.
2917 *WARNING* If your board configuration uses automatic
2918 detection of the RAM size, you must make sure that
2919 this memory test is non-destructive. So far, the
2920 following board configurations are known to be
2923 IVMS8, IVML24, SPD8xx, TQM8xxL,
2924 HERMES, IP860, RPXlite, LWMON,
2927 - Access to physical memory region (> 4GB)
2928 Some basic support is provided for operations on memory not
2929 normally accessible to U-Boot - e.g. some architectures
2930 support access to more than 4GB of memory on 32-bit
2931 machines using physical address extension or similar.
2932 Define CONFIG_PHYSMEM to access this basic support, which
2933 currently only supports clearing the memory.
2938 Define this variable to stop the system in case of a
2939 fatal error, so that you have to reset it manually.
2940 This is probably NOT a good idea for an embedded
2941 system where you want the system to reboot
2942 automatically as fast as possible, but it may be
2943 useful during development since you can try to debug
2944 the conditions that lead to the situation.
2946 CONFIG_NET_RETRY_COUNT
2948 This variable defines the number of retries for
2949 network operations like ARP, RARP, TFTP, or BOOTP
2950 before giving up the operation. If not defined, a
2951 default value of 5 is used.
2955 Timeout waiting for an ARP reply in milliseconds.
2959 Timeout in milliseconds used in NFS protocol.
2960 If you encounter "ERROR: Cannot umount" in nfs command,
2961 try longer timeout such as
2962 #define CONFIG_NFS_TIMEOUT 10000UL
2964 - Command Interpreter:
2965 CONFIG_AUTO_COMPLETE
2967 Enable auto completion of commands using TAB.
2969 CONFIG_SYS_PROMPT_HUSH_PS2
2971 This defines the secondary prompt string, which is
2972 printed when the command interpreter needs more input
2973 to complete a command. Usually "> ".
2977 In the current implementation, the local variables
2978 space and global environment variables space are
2979 separated. Local variables are those you define by
2980 simply typing `name=value'. To access a local
2981 variable later on, you have write `$name' or
2982 `${name}'; to execute the contents of a variable
2983 directly type `$name' at the command prompt.
2985 Global environment variables are those you use
2986 setenv/printenv to work with. To run a command stored
2987 in such a variable, you need to use the run command,
2988 and you must not use the '$' sign to access them.
2990 To store commands and special characters in a
2991 variable, please use double quotation marks
2992 surrounding the whole text of the variable, instead
2993 of the backslashes before semicolons and special
2996 - Command Line Editing and History:
2997 CONFIG_CMDLINE_EDITING
2999 Enable editing and History functions for interactive
3000 command line input operations
3002 - Default Environment:
3003 CONFIG_EXTRA_ENV_SETTINGS
3005 Define this to contain any number of null terminated
3006 strings (variable = value pairs) that will be part of
3007 the default environment compiled into the boot image.
3009 For example, place something like this in your
3010 board's config file:
3012 #define CONFIG_EXTRA_ENV_SETTINGS \
3016 Warning: This method is based on knowledge about the
3017 internal format how the environment is stored by the
3018 U-Boot code. This is NOT an official, exported
3019 interface! Although it is unlikely that this format
3020 will change soon, there is no guarantee either.
3021 You better know what you are doing here.
3023 Note: overly (ab)use of the default environment is
3024 discouraged. Make sure to check other ways to preset
3025 the environment like the "source" command or the
3028 CONFIG_ENV_VARS_UBOOT_CONFIG
3030 Define this in order to add variables describing the
3031 U-Boot build configuration to the default environment.
3032 These will be named arch, cpu, board, vendor, and soc.
3034 Enabling this option will cause the following to be defined:
3042 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3044 Define this in order to add variables describing certain
3045 run-time determined information about the hardware to the
3046 environment. These will be named board_name, board_rev.
3048 CONFIG_DELAY_ENVIRONMENT
3050 Normally the environment is loaded when the board is
3051 initialised so that it is available to U-Boot. This inhibits
3052 that so that the environment is not available until
3053 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3054 this is instead controlled by the value of
3055 /config/load-environment.
3057 - DataFlash Support:
3058 CONFIG_HAS_DATAFLASH
3060 Defining this option enables DataFlash features and
3061 allows to read/write in Dataflash via the standard
3064 - Serial Flash support
3067 Defining this option enables SPI flash commands
3068 'sf probe/read/write/erase/update'.
3070 Usage requires an initial 'probe' to define the serial
3071 flash parameters, followed by read/write/erase/update
3074 The following defaults may be provided by the platform
3075 to handle the common case when only a single serial
3076 flash is present on the system.
3078 CONFIG_SF_DEFAULT_BUS Bus identifier
3079 CONFIG_SF_DEFAULT_CS Chip-select
3080 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3081 CONFIG_SF_DEFAULT_SPEED in Hz
3085 Define this option to include a destructive SPI flash
3088 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3090 Define this option to use the Bank addr/Extended addr
3091 support on SPI flashes which has size > 16Mbytes.
3093 CONFIG_SF_DUAL_FLASH Dual flash memories
3095 Define this option to use dual flash support where two flash
3096 memories can be connected with a given cs line.
3097 Currently Xilinx Zynq qspi supports these type of connections.
3099 - SystemACE Support:
3102 Adding this option adds support for Xilinx SystemACE
3103 chips attached via some sort of local bus. The address
3104 of the chip must also be defined in the
3105 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3107 #define CONFIG_SYSTEMACE
3108 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3110 When SystemACE support is added, the "ace" device type
3111 becomes available to the fat commands, i.e. fatls.
3113 - TFTP Fixed UDP Port:
3116 If this is defined, the environment variable tftpsrcp
3117 is used to supply the TFTP UDP source port value.
3118 If tftpsrcp isn't defined, the normal pseudo-random port
3119 number generator is used.
3121 Also, the environment variable tftpdstp is used to supply
3122 the TFTP UDP destination port value. If tftpdstp isn't
3123 defined, the normal port 69 is used.
3125 The purpose for tftpsrcp is to allow a TFTP server to
3126 blindly start the TFTP transfer using the pre-configured
3127 target IP address and UDP port. This has the effect of
3128 "punching through" the (Windows XP) firewall, allowing
3129 the remainder of the TFTP transfer to proceed normally.
3130 A better solution is to properly configure the firewall,
3131 but sometimes that is not allowed.
3136 This enables a generic 'hash' command which can produce
3137 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3141 Enable the hash verify command (hash -v). This adds to code
3144 CONFIG_SHA1 - This option enables support of hashing using SHA1
3145 algorithm. The hash is calculated in software.
3146 CONFIG_SHA256 - This option enables support of hashing using
3147 SHA256 algorithm. The hash is calculated in software.
3148 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3149 for SHA1/SHA256 hashing.
3150 This affects the 'hash' command and also the
3151 hash_lookup_algo() function.
3152 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3153 hardware-acceleration for SHA1/SHA256 progressive hashing.
3154 Data can be streamed in a block at a time and the hashing
3155 is performed in hardware.
3157 Note: There is also a sha1sum command, which should perhaps
3158 be deprecated in favour of 'hash sha1'.
3160 - Freescale i.MX specific commands:
3161 CONFIG_CMD_HDMIDETECT
3162 This enables 'hdmidet' command which returns true if an
3163 HDMI monitor is detected. This command is i.MX 6 specific.
3166 This enables the 'bmode' (bootmode) command for forcing
3167 a boot from specific media.
3169 This is useful for forcing the ROM's usb downloader to
3170 activate upon a watchdog reset which is nice when iterating
3171 on U-Boot. Using the reset button or running bmode normal
3172 will set it back to normal. This command currently
3173 supports i.MX53 and i.MX6.
3178 This enables the RSA algorithm used for FIT image verification
3179 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3181 The Modular Exponentiation algorithm in RSA is implemented using
3182 driver model. So CONFIG_DM needs to be enabled by default for this
3183 library to function.
3185 The signing part is build into mkimage regardless of this
3186 option. The software based modular exponentiation is built into
3187 mkimage irrespective of this option.
3189 - bootcount support:
3190 CONFIG_BOOTCOUNT_LIMIT
3192 This enables the bootcounter support, see:
3193 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3196 enable special bootcounter support on at91sam9xe based boards.
3198 enable special bootcounter support on blackfin based boards.
3200 enable special bootcounter support on da850 based boards.
3201 CONFIG_BOOTCOUNT_RAM
3202 enable support for the bootcounter in RAM
3203 CONFIG_BOOTCOUNT_I2C
3204 enable support for the bootcounter on an i2c (like RTC) device.
3205 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3206 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3208 CONFIG_BOOTCOUNT_ALEN = address len
3210 - Show boot progress:
3211 CONFIG_SHOW_BOOT_PROGRESS
3213 Defining this option allows to add some board-
3214 specific code (calling a user-provided function
3215 "show_boot_progress(int)") that enables you to show
3216 the system's boot progress on some display (for
3217 example, some LED's) on your board. At the moment,
3218 the following checkpoints are implemented:
3221 Legacy uImage format:
3224 1 common/cmd_bootm.c before attempting to boot an image
3225 -1 common/cmd_bootm.c Image header has bad magic number
3226 2 common/cmd_bootm.c Image header has correct magic number
3227 -2 common/cmd_bootm.c Image header has bad checksum
3228 3 common/cmd_bootm.c Image header has correct checksum
3229 -3 common/cmd_bootm.c Image data has bad checksum
3230 4 common/cmd_bootm.c Image data has correct checksum
3231 -4 common/cmd_bootm.c Image is for unsupported architecture
3232 5 common/cmd_bootm.c Architecture check OK
3233 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3234 6 common/cmd_bootm.c Image Type check OK
3235 -6 common/cmd_bootm.c gunzip uncompression error
3236 -7 common/cmd_bootm.c Unimplemented compression type
3237 7 common/cmd_bootm.c Uncompression OK
3238 8 common/cmd_bootm.c No uncompress/copy overwrite error
3239 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3241 9 common/image.c Start initial ramdisk verification
3242 -10 common/image.c Ramdisk header has bad magic number
3243 -11 common/image.c Ramdisk header has bad checksum
3244 10 common/image.c Ramdisk header is OK
3245 -12 common/image.c Ramdisk data has bad checksum
3246 11 common/image.c Ramdisk data has correct checksum
3247 12 common/image.c Ramdisk verification complete, start loading
3248 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3249 13 common/image.c Start multifile image verification
3250 14 common/image.c No initial ramdisk, no multifile, continue.
3252 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3254 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3255 -31 post/post.c POST test failed, detected by post_output_backlog()
3256 -32 post/post.c POST test failed, detected by post_run_single()
3258 34 common/cmd_doc.c before loading a Image from a DOC device
3259 -35 common/cmd_doc.c Bad usage of "doc" command
3260 35 common/cmd_doc.c correct usage of "doc" command
3261 -36 common/cmd_doc.c No boot device
3262 36 common/cmd_doc.c correct boot device
3263 -37 common/cmd_doc.c Unknown Chip ID on boot device
3264 37 common/cmd_doc.c correct chip ID found, device available
3265 -38 common/cmd_doc.c Read Error on boot device
3266 38 common/cmd_doc.c reading Image header from DOC device OK
3267 -39 common/cmd_doc.c Image header has bad magic number
3268 39 common/cmd_doc.c Image header has correct magic number
3269 -40 common/cmd_doc.c Error reading Image from DOC device
3270 40 common/cmd_doc.c Image header has correct magic number
3271 41 common/cmd_ide.c before loading a Image from a IDE device
3272 -42 common/cmd_ide.c Bad usage of "ide" command
3273 42 common/cmd_ide.c correct usage of "ide" command
3274 -43 common/cmd_ide.c No boot device
3275 43 common/cmd_ide.c boot device found
3276 -44 common/cmd_ide.c Device not available
3277 44 common/cmd_ide.c Device available
3278 -45 common/cmd_ide.c wrong partition selected
3279 45 common/cmd_ide.c partition selected
3280 -46 common/cmd_ide.c Unknown partition table
3281 46 common/cmd_ide.c valid partition table found
3282 -47 common/cmd_ide.c Invalid partition type
3283 47 common/cmd_ide.c correct partition type
3284 -48 common/cmd_ide.c Error reading Image Header on boot device
3285 48 common/cmd_ide.c reading Image Header from IDE device OK
3286 -49 common/cmd_ide.c Image header has bad magic number
3287 49 common/cmd_ide.c Image header has correct magic number
3288 -50 common/cmd_ide.c Image header has bad checksum
3289 50 common/cmd_ide.c Image header has correct checksum
3290 -51 common/cmd_ide.c Error reading Image from IDE device
3291 51 common/cmd_ide.c reading Image from IDE device OK
3292 52 common/cmd_nand.c before loading a Image from a NAND device
3293 -53 common/cmd_nand.c Bad usage of "nand" command
3294 53 common/cmd_nand.c correct usage of "nand" command
3295 -54 common/cmd_nand.c No boot device
3296 54 common/cmd_nand.c boot device found
3297 -55 common/cmd_nand.c Unknown Chip ID on boot device
3298 55 common/cmd_nand.c correct chip ID found, device available
3299 -56 common/cmd_nand.c Error reading Image Header on boot device
3300 56 common/cmd_nand.c reading Image Header from NAND device OK
3301 -57 common/cmd_nand.c Image header has bad magic number
3302 57 common/cmd_nand.c Image header has correct magic number
3303 -58 common/cmd_nand.c Error reading Image from NAND device
3304 58 common/cmd_nand.c reading Image from NAND device OK
3306 -60 common/env_common.c Environment has a bad CRC, using default
3308 64 net/eth.c starting with Ethernet configuration.
3309 -64 net/eth.c no Ethernet found.
3310 65 net/eth.c Ethernet found.
3312 -80 common/cmd_net.c usage wrong
3313 80 common/cmd_net.c before calling net_loop()
3314 -81 common/cmd_net.c some error in net_loop() occurred
3315 81 common/cmd_net.c net_loop() back without error
3316 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3317 82 common/cmd_net.c trying automatic boot
3318 83 common/cmd_net.c running "source" command
3319 -83 common/cmd_net.c some error in automatic boot or "source" command
3320 84 common/cmd_net.c end without errors
3325 100 common/cmd_bootm.c Kernel FIT Image has correct format
3326 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3327 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3328 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3329 102 common/cmd_bootm.c Kernel unit name specified
3330 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3331 103 common/cmd_bootm.c Found configuration node
3332 104 common/cmd_bootm.c Got kernel subimage node offset
3333 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3334 105 common/cmd_bootm.c Kernel subimage hash verification OK
3335 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3336 106 common/cmd_bootm.c Architecture check OK
3337 -106 common/cmd_bootm.c Kernel subimage has wrong type
3338 107 common/cmd_bootm.c Kernel subimage type OK
3339 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3340 108 common/cmd_bootm.c Got kernel subimage data/size
3341 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3342 -109 common/cmd_bootm.c Can't get kernel subimage type
3343 -110 common/cmd_bootm.c Can't get kernel subimage comp
3344 -111 common/cmd_bootm.c Can't get kernel subimage os
3345 -112 common/cmd_bootm.c Can't get kernel subimage load address
3346 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3348 120 common/image.c Start initial ramdisk verification
3349 -120 common/image.c Ramdisk FIT image has incorrect format
3350 121 common/image.c Ramdisk FIT image has correct format
3351 122 common/image.c No ramdisk subimage unit name, using configuration
3352 -122 common/image.c Can't get configuration for ramdisk subimage
3353 123 common/image.c Ramdisk unit name specified
3354 -124 common/image.c Can't get ramdisk subimage node offset
3355 125 common/image.c Got ramdisk subimage node offset
3356 -125 common/image.c Ramdisk subimage hash verification failed
3357 126 common/image.c Ramdisk subimage hash verification OK
3358 -126 common/image.c Ramdisk subimage for unsupported architecture
3359 127 common/image.c Architecture check OK
3360 -127 common/image.c Can't get ramdisk subimage data/size
3361 128 common/image.c Got ramdisk subimage data/size
3362 129 common/image.c Can't get ramdisk load address
3363 -129 common/image.c Got ramdisk load address
3365 -130 common/cmd_doc.c Incorrect FIT image format
3366 131 common/cmd_doc.c FIT image format OK
3368 -140 common/cmd_ide.c Incorrect FIT image format
3369 141 common/cmd_ide.c FIT image format OK
3371 -150 common/cmd_nand.c Incorrect FIT image format
3372 151 common/cmd_nand.c FIT image format OK
3374 - legacy image format:
3375 CONFIG_IMAGE_FORMAT_LEGACY
3376 enables the legacy image format support in U-Boot.
3379 enabled if CONFIG_FIT_SIGNATURE is not defined.
3381 CONFIG_DISABLE_IMAGE_LEGACY
3382 disable the legacy image format
3384 This define is introduced, as the legacy image format is
3385 enabled per default for backward compatibility.
3387 - FIT image support:
3389 Enable support for the FIT uImage format.
3391 CONFIG_FIT_BEST_MATCH
3392 When no configuration is explicitly selected, default to the
3393 one whose fdt's compatibility field best matches that of
3394 U-Boot itself. A match is considered "best" if it matches the
3395 most specific compatibility entry of U-Boot's fdt's root node.
3396 The order of entries in the configuration's fdt is ignored.
3398 CONFIG_FIT_SIGNATURE
3399 This option enables signature verification of FIT uImages,
3400 using a hash signed and verified using RSA. If
3401 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3402 hashing is available using hardware, RSA library will use it.
3403 See doc/uImage.FIT/signature.txt for more details.
3405 WARNING: When relying on signed FIT images with required
3406 signature check the legacy image format is default
3407 disabled. If a board need legacy image format support
3408 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3410 CONFIG_FIT_DISABLE_SHA256
3411 Supporting SHA256 hashes has quite an impact on binary size.
3412 For constrained systems sha256 hash support can be disabled
3415 - Standalone program support:
3416 CONFIG_STANDALONE_LOAD_ADDR
3418 This option defines a board specific value for the
3419 address where standalone program gets loaded, thus
3420 overwriting the architecture dependent default
3423 - Frame Buffer Address:
3426 Define CONFIG_FB_ADDR if you want to use specific
3427 address for frame buffer. This is typically the case
3428 when using a graphics controller has separate video
3429 memory. U-Boot will then place the frame buffer at
3430 the given address instead of dynamically reserving it
3431 in system RAM by calling lcd_setmem(), which grabs
3432 the memory for the frame buffer depending on the
3433 configured panel size.
3435 Please see board_init_f function.
3437 - Automatic software updates via TFTP server
3439 CONFIG_UPDATE_TFTP_CNT_MAX
3440 CONFIG_UPDATE_TFTP_MSEC_MAX
3442 These options enable and control the auto-update feature;
3443 for a more detailed description refer to doc/README.update.
3445 - MTD Support (mtdparts command, UBI support)
3448 Adds the MTD device infrastructure from the Linux kernel.
3449 Needed for mtdparts command support.
3451 CONFIG_MTD_PARTITIONS
3453 Adds the MTD partitioning infrastructure from the Linux
3454 kernel. Needed for UBI support.
3459 Adds commands for interacting with MTD partitions formatted
3460 with the UBI flash translation layer
3462 Requires also defining CONFIG_RBTREE
3464 CONFIG_UBI_SILENCE_MSG
3466 Make the verbose messages from UBI stop printing. This leaves
3467 warnings and errors enabled.
3470 CONFIG_MTD_UBI_WL_THRESHOLD
3471 This parameter defines the maximum difference between the highest
3472 erase counter value and the lowest erase counter value of eraseblocks
3473 of UBI devices. When this threshold is exceeded, UBI starts performing
3474 wear leveling by means of moving data from eraseblock with low erase
3475 counter to eraseblocks with high erase counter.
3477 The default value should be OK for SLC NAND flashes, NOR flashes and
3478 other flashes which have eraseblock life-cycle 100000 or more.
3479 However, in case of MLC NAND flashes which typically have eraseblock
3480 life-cycle less than 10000, the threshold should be lessened (e.g.,
3481 to 128 or 256, although it does not have to be power of 2).
3485 CONFIG_MTD_UBI_BEB_LIMIT
3486 This option specifies the maximum bad physical eraseblocks UBI
3487 expects on the MTD device (per 1024 eraseblocks). If the
3488 underlying flash does not admit of bad eraseblocks (e.g. NOR
3489 flash), this value is ignored.
3491 NAND datasheets often specify the minimum and maximum NVM
3492 (Number of Valid Blocks) for the flashes' endurance lifetime.
3493 The maximum expected bad eraseblocks per 1024 eraseblocks
3494 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3495 which gives 20 for most NANDs (MaxNVB is basically the total
3496 count of eraseblocks on the chip).
3498 To put it differently, if this value is 20, UBI will try to
3499 reserve about 1.9% of physical eraseblocks for bad blocks
3500 handling. And that will be 1.9% of eraseblocks on the entire
3501 NAND chip, not just the MTD partition UBI attaches. This means
3502 that if you have, say, a NAND flash chip admits maximum 40 bad
3503 eraseblocks, and it is split on two MTD partitions of the same
3504 size, UBI will reserve 40 eraseblocks when attaching a
3509 CONFIG_MTD_UBI_FASTMAP
3510 Fastmap is a mechanism which allows attaching an UBI device
3511 in nearly constant time. Instead of scanning the whole MTD device it
3512 only has to locate a checkpoint (called fastmap) on the device.
3513 The on-flash fastmap contains all information needed to attach
3514 the device. Using fastmap makes only sense on large devices where
3515 attaching by scanning takes long. UBI will not automatically install
3516 a fastmap on old images, but you can set the UBI parameter
3517 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3518 that fastmap-enabled images are still usable with UBI implementations
3519 without fastmap support. On typical flash devices the whole fastmap
3520 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3522 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3523 Set this parameter to enable fastmap automatically on images
3530 Adds commands for interacting with UBI volumes formatted as
3531 UBIFS. UBIFS is read-only in u-boot.
3533 Requires UBI support as well as CONFIG_LZO
3535 CONFIG_UBIFS_SILENCE_MSG
3537 Make the verbose messages from UBIFS stop printing. This leaves
3538 warnings and errors enabled.
3542 Enable building of SPL globally.
3545 LDSCRIPT for linking the SPL binary.
3547 CONFIG_SPL_MAX_FOOTPRINT
3548 Maximum size in memory allocated to the SPL, BSS included.
3549 When defined, the linker checks that the actual memory
3550 used by SPL from _start to __bss_end does not exceed it.
3551 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3552 must not be both defined at the same time.
3555 Maximum size of the SPL image (text, data, rodata, and
3556 linker lists sections), BSS excluded.
3557 When defined, the linker checks that the actual size does
3560 CONFIG_SPL_TEXT_BASE
3561 TEXT_BASE for linking the SPL binary.
3563 CONFIG_SPL_RELOC_TEXT_BASE
3564 Address to relocate to. If unspecified, this is equal to
3565 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3567 CONFIG_SPL_BSS_START_ADDR
3568 Link address for the BSS within the SPL binary.
3570 CONFIG_SPL_BSS_MAX_SIZE
3571 Maximum size in memory allocated to the SPL BSS.
3572 When defined, the linker checks that the actual memory used
3573 by SPL from __bss_start to __bss_end does not exceed it.
3574 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3575 must not be both defined at the same time.
3578 Adress of the start of the stack SPL will use
3580 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3581 When defined, SPL will panic() if the image it has
3582 loaded does not have a signature.
3583 Defining this is useful when code which loads images
3584 in SPL cannot guarantee that absolutely all read errors
3586 An example is the LPC32XX MLC NAND driver, which will
3587 consider that a completely unreadable NAND block is bad,
3588 and thus should be skipped silently.
3590 CONFIG_SPL_RELOC_STACK
3591 Adress of the start of the stack SPL will use after
3592 relocation. If unspecified, this is equal to
3595 CONFIG_SYS_SPL_MALLOC_START
3596 Starting address of the malloc pool used in SPL.
3598 CONFIG_SYS_SPL_MALLOC_SIZE
3599 The size of the malloc pool used in SPL.
3601 CONFIG_SPL_FRAMEWORK
3602 Enable the SPL framework under common/. This framework
3603 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3604 NAND loading of the Linux Kernel.
3607 Enable booting directly to an OS from SPL.
3608 See also: doc/README.falcon
3610 CONFIG_SPL_DISPLAY_PRINT
3611 For ARM, enable an optional function to print more information
3612 about the running system.
3614 CONFIG_SPL_INIT_MINIMAL
3615 Arch init code should be built for a very small image
3617 CONFIG_SPL_LIBCOMMON_SUPPORT
3618 Support for common/libcommon.o in SPL binary
3620 CONFIG_SPL_LIBDISK_SUPPORT
3621 Support for disk/libdisk.o in SPL binary
3623 CONFIG_SPL_I2C_SUPPORT
3624 Support for drivers/i2c/libi2c.o in SPL binary
3626 CONFIG_SPL_GPIO_SUPPORT
3627 Support for drivers/gpio/libgpio.o in SPL binary
3629 CONFIG_SPL_MMC_SUPPORT
3630 Support for drivers/mmc/libmmc.o in SPL binary
3632 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3633 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3634 Address and partition on the MMC to load U-Boot from
3635 when the MMC is being used in raw mode.
3637 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3638 Partition on the MMC to load U-Boot from when the MMC is being
3641 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3642 Sector to load kernel uImage from when MMC is being
3643 used in raw mode (for Falcon mode)
3645 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3646 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3647 Sector and number of sectors to load kernel argument
3648 parameters from when MMC is being used in raw mode
3651 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3652 Partition on the MMC to load U-Boot from when the MMC is being
3655 CONFIG_SPL_FAT_SUPPORT
3656 Support for fs/fat/libfat.o in SPL binary
3658 CONFIG_SPL_EXT_SUPPORT
3659 Support for EXT filesystem in SPL binary
3661 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3662 Filename to read to load U-Boot when reading from filesystem
3664 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3665 Filename to read to load kernel uImage when reading
3666 from filesystem (for Falcon mode)
3668 CONFIG_SPL_FS_LOAD_ARGS_NAME
3669 Filename to read to load kernel argument parameters
3670 when reading from filesystem (for Falcon mode)
3672 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3673 Set this for NAND SPL on PPC mpc83xx targets, so that
3674 start.S waits for the rest of the SPL to load before
3675 continuing (the hardware starts execution after just
3676 loading the first page rather than the full 4K).
3678 CONFIG_SPL_SKIP_RELOCATE
3679 Avoid SPL relocation
3681 CONFIG_SPL_NAND_BASE
3682 Include nand_base.c in the SPL. Requires
3683 CONFIG_SPL_NAND_DRIVERS.
3685 CONFIG_SPL_NAND_DRIVERS
3686 SPL uses normal NAND drivers, not minimal drivers.
3689 Include standard software ECC in the SPL
3691 CONFIG_SPL_NAND_SIMPLE
3692 Support for NAND boot using simple NAND drivers that
3693 expose the cmd_ctrl() interface.
3695 CONFIG_SPL_MTD_SUPPORT
3696 Support for the MTD subsystem within SPL. Useful for
3697 environment on NAND support within SPL.
3699 CONFIG_SPL_NAND_RAW_ONLY
3700 Support to boot only raw u-boot.bin images. Use this only
3701 if you need to save space.
3703 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3704 Set for the SPL on PPC mpc8xxx targets, support for
3705 drivers/ddr/fsl/libddr.o in SPL binary.
3707 CONFIG_SPL_COMMON_INIT_DDR
3708 Set for common ddr init with serial presence detect in
3711 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3712 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3713 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3714 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3715 CONFIG_SYS_NAND_ECCBYTES
3716 Defines the size and behavior of the NAND that SPL uses
3719 CONFIG_SPL_NAND_BOOT
3720 Add support NAND boot
3722 CONFIG_SYS_NAND_U_BOOT_OFFS
3723 Location in NAND to read U-Boot from
3725 CONFIG_SYS_NAND_U_BOOT_DST
3726 Location in memory to load U-Boot to
3728 CONFIG_SYS_NAND_U_BOOT_SIZE
3729 Size of image to load
3731 CONFIG_SYS_NAND_U_BOOT_START
3732 Entry point in loaded image to jump to
3734 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3735 Define this if you need to first read the OOB and then the
3736 data. This is used, for example, on davinci platforms.
3738 CONFIG_SPL_OMAP3_ID_NAND
3739 Support for an OMAP3-specific set of functions to return the
3740 ID and MFR of the first attached NAND chip, if present.
3742 CONFIG_SPL_SERIAL_SUPPORT
3743 Support for drivers/serial/libserial.o in SPL binary
3745 CONFIG_SPL_SPI_FLASH_SUPPORT
3746 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3748 CONFIG_SPL_SPI_SUPPORT
3749 Support for drivers/spi/libspi.o in SPL binary
3751 CONFIG_SPL_RAM_DEVICE
3752 Support for running image already present in ram, in SPL binary
3754 CONFIG_SPL_LIBGENERIC_SUPPORT
3755 Support for lib/libgeneric.o in SPL binary
3757 CONFIG_SPL_ENV_SUPPORT
3758 Support for the environment operating in SPL binary
3760 CONFIG_SPL_NET_SUPPORT
3761 Support for the net/libnet.o in SPL binary.
3762 It conflicts with SPL env from storage medium specified by
3763 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3766 Image offset to which the SPL should be padded before appending
3767 the SPL 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.
3773 Final target image containing SPL and payload. Some SPLs
3774 use an arch-specific makefile fragment instead, for
3775 example if more than one image needs to be produced.
3777 CONFIG_FIT_SPL_PRINT
3778 Printing information about a FIT image adds quite a bit of
3779 code to SPL. So this is normally disabled in SPL. Use this
3780 option to re-enable it. This will affect the output of the
3781 bootm command when booting a FIT image.
3785 Enable building of TPL globally.
3788 Image offset to which the TPL should be padded before appending
3789 the TPL payload. By default, this is defined as
3790 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3791 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3792 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3797 [so far only for SMDK2400 boards]
3799 - Modem support enable:
3800 CONFIG_MODEM_SUPPORT
3802 - RTS/CTS Flow control enable:
3805 - Modem debug support:
3806 CONFIG_MODEM_SUPPORT_DEBUG
3808 Enables debugging stuff (char screen[1024], dbg())
3809 for modem support. Useful only with BDI2000.
3811 - Interrupt support (PPC):
3813 There are common interrupt_init() and timer_interrupt()
3814 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3815 for CPU specific initialization. interrupt_init_cpu()
3816 should set decrementer_count to appropriate value. If
3817 CPU resets decrementer automatically after interrupt
3818 (ppc4xx) it should set decrementer_count to zero.
3819 timer_interrupt() calls timer_interrupt_cpu() for CPU
3820 specific handling. If board has watchdog / status_led
3821 / other_activity_monitor it works automatically from
3822 general timer_interrupt().
3826 In the target system modem support is enabled when a
3827 specific key (key combination) is pressed during
3828 power-on. Otherwise U-Boot will boot normally
3829 (autoboot). The key_pressed() function is called from
3830 board_init(). Currently key_pressed() is a dummy
3831 function, returning 1 and thus enabling modem
3834 If there are no modem init strings in the
3835 environment, U-Boot proceed to autoboot; the
3836 previous output (banner, info printfs) will be
3839 See also: doc/README.Modem
3841 Board initialization settings:
3842 ------------------------------
3844 During Initialization u-boot calls a number of board specific functions
3845 to allow the preparation of board specific prerequisites, e.g. pin setup
3846 before drivers are initialized. To enable these callbacks the
3847 following configuration macros have to be defined. Currently this is
3848 architecture specific, so please check arch/your_architecture/lib/board.c
3849 typically in board_init_f() and board_init_r().
3851 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3852 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3853 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3854 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3856 Configuration Settings:
3857 -----------------------
3859 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3860 Optionally it can be defined to support 64-bit memory commands.
3862 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3863 undefine this when you're short of memory.
3865 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3866 width of the commands listed in the 'help' command output.
3868 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3869 prompt for user input.
3871 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3873 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3875 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3877 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3878 the application (usually a Linux kernel) when it is
3881 - CONFIG_SYS_BAUDRATE_TABLE:
3882 List of legal baudrate settings for this board.
3884 - CONFIG_SYS_CONSOLE_INFO_QUIET
3885 Suppress display of console information at boot.
3887 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3888 If the board specific function
3889 extern int overwrite_console (void);
3890 returns 1, the stdin, stderr and stdout are switched to the
3891 serial port, else the settings in the environment are used.
3893 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3894 Enable the call to overwrite_console().
3896 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3897 Enable overwrite of previous console environment settings.
3899 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3900 Begin and End addresses of the area used by the
3903 - CONFIG_SYS_ALT_MEMTEST:
3904 Enable an alternate, more extensive memory test.
3906 - CONFIG_SYS_MEMTEST_SCRATCH:
3907 Scratch address used by the alternate memory test
3908 You only need to set this if address zero isn't writeable
3910 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3911 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3912 this specified memory area will get subtracted from the top
3913 (end) of RAM and won't get "touched" at all by U-Boot. By
3914 fixing up gd->ram_size the Linux kernel should gets passed
3915 the now "corrected" memory size and won't touch it either.
3916 This should work for arch/ppc and arch/powerpc. Only Linux
3917 board ports in arch/powerpc with bootwrapper support that
3918 recalculate the memory size from the SDRAM controller setup
3919 will have to get fixed in Linux additionally.
3921 This option can be used as a workaround for the 440EPx/GRx
3922 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3925 WARNING: Please make sure that this value is a multiple of
3926 the Linux page size (normally 4k). If this is not the case,
3927 then the end address of the Linux memory will be located at a
3928 non page size aligned address and this could cause major
3931 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3932 Enable temporary baudrate change while serial download
3934 - CONFIG_SYS_SDRAM_BASE:
3935 Physical start address of SDRAM. _Must_ be 0 here.
3937 - CONFIG_SYS_MBIO_BASE:
3938 Physical start address of Motherboard I/O (if using a
3941 - CONFIG_SYS_FLASH_BASE:
3942 Physical start address of Flash memory.
3944 - CONFIG_SYS_MONITOR_BASE:
3945 Physical start address of boot monitor code (set by
3946 make config files to be same as the text base address
3947 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3948 CONFIG_SYS_FLASH_BASE when booting from flash.
3950 - CONFIG_SYS_MONITOR_LEN:
3951 Size of memory reserved for monitor code, used to
3952 determine _at_compile_time_ (!) if the environment is
3953 embedded within the U-Boot image, or in a separate
3956 - CONFIG_SYS_MALLOC_LEN:
3957 Size of DRAM reserved for malloc() use.
3959 - CONFIG_SYS_MALLOC_F_LEN
3960 Size of the malloc() pool for use before relocation. If
3961 this is defined, then a very simple malloc() implementation
3962 will become available before relocation. The address is just
3963 below the global data, and the stack is moved down to make
3966 This feature allocates regions with increasing addresses
3967 within the region. calloc() is supported, but realloc()
3968 is not available. free() is supported but does nothing.
3969 The memory will be freed (or in fact just forgotten) when
3970 U-Boot relocates itself.
3972 Pre-relocation malloc() is only supported on ARM and sandbox
3973 at present but is fairly easy to enable for other archs.
3975 - CONFIG_SYS_MALLOC_SIMPLE
3976 Provides a simple and small malloc() and calloc() for those
3977 boards which do not use the full malloc in SPL (which is
3978 enabled with CONFIG_SYS_SPL_MALLOC_START).
3980 - CONFIG_SYS_NONCACHED_MEMORY:
3981 Size of non-cached memory area. This area of memory will be
3982 typically located right below the malloc() area and mapped
3983 uncached in the MMU. This is useful for drivers that would
3984 otherwise require a lot of explicit cache maintenance. For
3985 some drivers it's also impossible to properly maintain the
3986 cache. For example if the regions that need to be flushed
3987 are not a multiple of the cache-line size, *and* padding
3988 cannot be allocated between the regions to align them (i.e.
3989 if the HW requires a contiguous array of regions, and the
3990 size of each region is not cache-aligned), then a flush of
3991 one region may result in overwriting data that hardware has
3992 written to another region in the same cache-line. This can
3993 happen for example in network drivers where descriptors for
3994 buffers are typically smaller than the CPU cache-line (e.g.
3995 16 bytes vs. 32 or 64 bytes).
3997 Non-cached memory is only supported on 32-bit ARM at present.
3999 - CONFIG_SYS_BOOTM_LEN:
4000 Normally compressed uImages are limited to an
4001 uncompressed size of 8 MBytes. If this is not enough,
4002 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4003 to adjust this setting to your needs.
4005 - CONFIG_SYS_BOOTMAPSZ:
4006 Maximum size of memory mapped by the startup code of
4007 the Linux kernel; all data that must be processed by
4008 the Linux kernel (bd_info, boot arguments, FDT blob if
4009 used) must be put below this limit, unless "bootm_low"
4010 environment variable is defined and non-zero. In such case
4011 all data for the Linux kernel must be between "bootm_low"
4012 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4013 variable "bootm_mapsize" will override the value of
4014 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4015 then the value in "bootm_size" will be used instead.
4017 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4018 Enable initrd_high functionality. If defined then the
4019 initrd_high feature is enabled and the bootm ramdisk subcommand
4022 - CONFIG_SYS_BOOT_GET_CMDLINE:
4023 Enables allocating and saving kernel cmdline in space between
4024 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4026 - CONFIG_SYS_BOOT_GET_KBD:
4027 Enables allocating and saving a kernel copy of the bd_info in
4028 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4030 - CONFIG_SYS_MAX_FLASH_BANKS:
4031 Max number of Flash memory banks
4033 - CONFIG_SYS_MAX_FLASH_SECT:
4034 Max number of sectors on a Flash chip
4036 - CONFIG_SYS_FLASH_ERASE_TOUT:
4037 Timeout for Flash erase operations (in ms)
4039 - CONFIG_SYS_FLASH_WRITE_TOUT:
4040 Timeout for Flash write operations (in ms)
4042 - CONFIG_SYS_FLASH_LOCK_TOUT
4043 Timeout for Flash set sector lock bit operation (in ms)
4045 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4046 Timeout for Flash clear lock bits operation (in ms)
4048 - CONFIG_SYS_FLASH_PROTECTION
4049 If defined, hardware flash sectors protection is used
4050 instead of U-Boot software protection.
4052 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4054 Enable TFTP transfers directly to flash memory;
4055 without this option such a download has to be
4056 performed in two steps: (1) download to RAM, and (2)
4057 copy from RAM to flash.
4059 The two-step approach is usually more reliable, since
4060 you can check if the download worked before you erase
4061 the flash, but in some situations (when system RAM is
4062 too limited to allow for a temporary copy of the
4063 downloaded image) this option may be very useful.
4065 - CONFIG_SYS_FLASH_CFI:
4066 Define if the flash driver uses extra elements in the
4067 common flash structure for storing flash geometry.
4069 - CONFIG_FLASH_CFI_DRIVER
4070 This option also enables the building of the cfi_flash driver
4071 in the drivers directory
4073 - CONFIG_FLASH_CFI_MTD
4074 This option enables the building of the cfi_mtd driver
4075 in the drivers directory. The driver exports CFI flash
4078 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4079 Use buffered writes to flash.
4081 - CONFIG_FLASH_SPANSION_S29WS_N
4082 s29ws-n MirrorBit flash has non-standard addresses for buffered
4085 - CONFIG_SYS_FLASH_QUIET_TEST
4086 If this option is defined, the common CFI flash doesn't
4087 print it's warning upon not recognized FLASH banks. This
4088 is useful, if some of the configured banks are only
4089 optionally available.
4091 - CONFIG_FLASH_SHOW_PROGRESS
4092 If defined (must be an integer), print out countdown
4093 digits and dots. Recommended value: 45 (9..1) for 80
4094 column displays, 15 (3..1) for 40 column displays.
4096 - CONFIG_FLASH_VERIFY
4097 If defined, the content of the flash (destination) is compared
4098 against the source after the write operation. An error message
4099 will be printed when the contents are not identical.
4100 Please note that this option is useless in nearly all cases,
4101 since such flash programming errors usually are detected earlier
4102 while unprotecting/erasing/programming. Please only enable
4103 this option if you really know what you are doing.
4105 - CONFIG_SYS_RX_ETH_BUFFER:
4106 Defines the number of Ethernet receive buffers. On some
4107 Ethernet controllers it is recommended to set this value
4108 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4109 buffers can be full shortly after enabling the interface
4110 on high Ethernet traffic.
4111 Defaults to 4 if not defined.
4113 - CONFIG_ENV_MAX_ENTRIES
4115 Maximum number of entries in the hash table that is used
4116 internally to store the environment settings. The default
4117 setting is supposed to be generous and should work in most
4118 cases. This setting can be used to tune behaviour; see
4119 lib/hashtable.c for details.
4121 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4122 - CONFIG_ENV_FLAGS_LIST_STATIC
4123 Enable validation of the values given to environment variables when
4124 calling env set. Variables can be restricted to only decimal,
4125 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4126 the variables can also be restricted to IP address or MAC address.
4128 The format of the list is:
4129 type_attribute = [s|d|x|b|i|m]
4130 access_attribute = [a|r|o|c]
4131 attributes = type_attribute[access_attribute]
4132 entry = variable_name[:attributes]
4135 The type attributes are:
4136 s - String (default)
4139 b - Boolean ([1yYtT|0nNfF])
4143 The access attributes are:
4149 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4150 Define this to a list (string) to define the ".flags"
4151 environment variable in the default or embedded environment.
4153 - CONFIG_ENV_FLAGS_LIST_STATIC
4154 Define this to a list (string) to define validation that
4155 should be done if an entry is not found in the ".flags"
4156 environment variable. To override a setting in the static
4157 list, simply add an entry for the same variable name to the
4160 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4161 If defined, don't allow the -f switch to env set override variable
4164 - CONFIG_SYS_GENERIC_BOARD
4165 This selects the architecture-generic board system instead of the
4166 architecture-specific board files. It is intended to move boards
4167 to this new framework over time. Defining this will disable the
4168 arch/foo/lib/board.c file and use common/board_f.c and
4169 common/board_r.c instead. To use this option your architecture
4170 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4171 If you find problems enabling this option on your board please report
4172 the problem and send patches!
4174 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4175 This is set by OMAP boards for the max time that reset should
4176 be asserted. See doc/README.omap-reset-time for details on how
4177 the value can be calculated on a given board.
4180 If stdint.h is available with your toolchain you can define this
4181 option to enable it. You can provide option 'USE_STDINT=1' when
4182 building U-Boot to enable this.
4184 The following definitions that deal with the placement and management
4185 of environment data (variable area); in general, we support the
4186 following configurations:
4188 - CONFIG_BUILD_ENVCRC:
4190 Builds up envcrc with the target environment so that external utils
4191 may easily extract it and embed it in final U-Boot images.
4193 - CONFIG_ENV_IS_IN_FLASH:
4195 Define this if the environment is in flash memory.
4197 a) The environment occupies one whole flash sector, which is
4198 "embedded" in the text segment with the U-Boot code. This
4199 happens usually with "bottom boot sector" or "top boot
4200 sector" type flash chips, which have several smaller
4201 sectors at the start or the end. For instance, such a
4202 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4203 such a case you would place the environment in one of the
4204 4 kB sectors - with U-Boot code before and after it. With
4205 "top boot sector" type flash chips, you would put the
4206 environment in one of the last sectors, leaving a gap
4207 between U-Boot and the environment.
4209 - CONFIG_ENV_OFFSET:
4211 Offset of environment data (variable area) to the
4212 beginning of flash memory; for instance, with bottom boot
4213 type flash chips the second sector can be used: the offset
4214 for this sector is given here.
4216 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4220 This is just another way to specify the start address of
4221 the flash sector containing the environment (instead of
4224 - CONFIG_ENV_SECT_SIZE:
4226 Size of the sector containing the environment.
4229 b) Sometimes flash chips have few, equal sized, BIG sectors.
4230 In such a case you don't want to spend a whole sector for
4235 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4236 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4237 of this flash sector for the environment. This saves
4238 memory for the RAM copy of the environment.
4240 It may also save flash memory if you decide to use this
4241 when your environment is "embedded" within U-Boot code,
4242 since then the remainder of the flash sector could be used
4243 for U-Boot code. It should be pointed out that this is
4244 STRONGLY DISCOURAGED from a robustness point of view:
4245 updating the environment in flash makes it always
4246 necessary to erase the WHOLE sector. If something goes
4247 wrong before the contents has been restored from a copy in
4248 RAM, your target system will be dead.
4250 - CONFIG_ENV_ADDR_REDUND
4251 CONFIG_ENV_SIZE_REDUND
4253 These settings describe a second storage area used to hold
4254 a redundant copy of the environment data, so that there is
4255 a valid backup copy in case there is a power failure during
4256 a "saveenv" operation.
4258 BE CAREFUL! Any changes to the flash layout, and some changes to the
4259 source code will make it necessary to adapt <board>/u-boot.lds*
4263 - CONFIG_ENV_IS_IN_NVRAM:
4265 Define this if you have some non-volatile memory device
4266 (NVRAM, battery buffered SRAM) which you want to use for the
4272 These two #defines are used to determine the memory area you
4273 want to use for environment. It is assumed that this memory
4274 can just be read and written to, without any special
4277 BE CAREFUL! The first access to the environment happens quite early
4278 in U-Boot initialization (when we try to get the setting of for the
4279 console baudrate). You *MUST* have mapped your NVRAM area then, or
4282 Please note that even with NVRAM we still use a copy of the
4283 environment in RAM: we could work on NVRAM directly, but we want to
4284 keep settings there always unmodified except somebody uses "saveenv"
4285 to save the current settings.
4288 - CONFIG_ENV_IS_IN_EEPROM:
4290 Use this if you have an EEPROM or similar serial access
4291 device and a driver for it.
4293 - CONFIG_ENV_OFFSET:
4296 These two #defines specify the offset and size of the
4297 environment area within the total memory of your EEPROM.
4299 - CONFIG_SYS_I2C_EEPROM_ADDR:
4300 If defined, specified the chip address of the EEPROM device.
4301 The default address is zero.
4303 - CONFIG_SYS_I2C_EEPROM_BUS:
4304 If defined, specified the i2c bus of the EEPROM device.
4306 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4307 If defined, the number of bits used to address bytes in a
4308 single page in the EEPROM device. A 64 byte page, for example
4309 would require six bits.
4311 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4312 If defined, the number of milliseconds to delay between
4313 page writes. The default is zero milliseconds.
4315 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4316 The length in bytes of the EEPROM memory array address. Note
4317 that this is NOT the chip address length!
4319 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4320 EEPROM chips that implement "address overflow" are ones
4321 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4322 address and the extra bits end up in the "chip address" bit
4323 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4326 Note that we consider the length of the address field to
4327 still be one byte because the extra address bits are hidden
4328 in the chip address.
4330 - CONFIG_SYS_EEPROM_SIZE:
4331 The size in bytes of the EEPROM device.
4333 - CONFIG_ENV_EEPROM_IS_ON_I2C
4334 define this, if you have I2C and SPI activated, and your
4335 EEPROM, which holds the environment, is on the I2C bus.
4337 - CONFIG_I2C_ENV_EEPROM_BUS
4338 if you have an Environment on an EEPROM reached over
4339 I2C muxes, you can define here, how to reach this
4340 EEPROM. For example:
4342 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4344 EEPROM which holds the environment, is reached over
4345 a pca9547 i2c mux with address 0x70, channel 3.
4347 - CONFIG_ENV_IS_IN_DATAFLASH:
4349 Define this if you have a DataFlash memory device which you
4350 want to use for the environment.
4352 - CONFIG_ENV_OFFSET:
4356 These three #defines specify the offset and size of the
4357 environment area within the total memory of your DataFlash placed
4358 at the specified address.
4360 - CONFIG_ENV_IS_IN_SPI_FLASH:
4362 Define this if you have a SPI Flash memory device which you
4363 want to use for the environment.
4365 - CONFIG_ENV_OFFSET:
4368 These two #defines specify the offset and size of the
4369 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4370 aligned to an erase sector boundary.
4372 - CONFIG_ENV_SECT_SIZE:
4374 Define the SPI flash's sector size.
4376 - CONFIG_ENV_OFFSET_REDUND (optional):
4378 This setting describes a second storage area of CONFIG_ENV_SIZE
4379 size used to hold a redundant copy of the environment data, so
4380 that there is a valid backup copy in case there is a power failure
4381 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4382 aligned to an erase sector boundary.
4384 - CONFIG_ENV_SPI_BUS (optional):
4385 - CONFIG_ENV_SPI_CS (optional):
4387 Define the SPI bus and chip select. If not defined they will be 0.
4389 - CONFIG_ENV_SPI_MAX_HZ (optional):
4391 Define the SPI max work clock. If not defined then use 1MHz.
4393 - CONFIG_ENV_SPI_MODE (optional):
4395 Define the SPI work mode. If not defined then use SPI_MODE_3.
4397 - CONFIG_ENV_IS_IN_REMOTE:
4399 Define this if you have a remote memory space which you
4400 want to use for the local device's environment.
4405 These two #defines specify the address and size of the
4406 environment area within the remote memory space. The
4407 local device can get the environment from remote memory
4408 space by SRIO or PCIE links.
4410 BE CAREFUL! For some special cases, the local device can not use
4411 "saveenv" command. For example, the local device will get the
4412 environment stored in a remote NOR flash by SRIO or PCIE link,
4413 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4415 - CONFIG_ENV_IS_IN_NAND:
4417 Define this if you have a NAND device which you want to use
4418 for the environment.
4420 - CONFIG_ENV_OFFSET:
4423 These two #defines specify the offset and size of the environment
4424 area within the first NAND device. CONFIG_ENV_OFFSET must be
4425 aligned to an erase block boundary.
4427 - CONFIG_ENV_OFFSET_REDUND (optional):
4429 This setting describes a second storage area of CONFIG_ENV_SIZE
4430 size used to hold a redundant copy of the environment data, so
4431 that there is a valid backup copy in case there is a power failure
4432 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4433 aligned to an erase block boundary.
4435 - CONFIG_ENV_RANGE (optional):
4437 Specifies the length of the region in which the environment
4438 can be written. This should be a multiple of the NAND device's
4439 block size. Specifying a range with more erase blocks than
4440 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4441 the range to be avoided.
4443 - CONFIG_ENV_OFFSET_OOB (optional):
4445 Enables support for dynamically retrieving the offset of the
4446 environment from block zero's out-of-band data. The
4447 "nand env.oob" command can be used to record this offset.
4448 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4449 using CONFIG_ENV_OFFSET_OOB.
4451 - CONFIG_NAND_ENV_DST
4453 Defines address in RAM to which the nand_spl code should copy the
4454 environment. If redundant environment is used, it will be copied to
4455 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4457 - CONFIG_ENV_IS_IN_UBI:
4459 Define this if you have an UBI volume that you want to use for the
4460 environment. This has the benefit of wear-leveling the environment
4461 accesses, which is important on NAND.
4463 - CONFIG_ENV_UBI_PART:
4465 Define this to a string that is the mtd partition containing the UBI.
4467 - CONFIG_ENV_UBI_VOLUME:
4469 Define this to the name of the volume that you want to store the
4472 - CONFIG_ENV_UBI_VOLUME_REDUND:
4474 Define this to the name of another volume to store a second copy of
4475 the environment in. This will enable redundant environments in UBI.
4476 It is assumed that both volumes are in the same MTD partition.
4478 - CONFIG_UBI_SILENCE_MSG
4479 - CONFIG_UBIFS_SILENCE_MSG
4481 You will probably want to define these to avoid a really noisy system
4482 when storing the env in UBI.
4484 - CONFIG_ENV_IS_IN_FAT:
4485 Define this if you want to use the FAT file system for the environment.
4487 - FAT_ENV_INTERFACE:
4489 Define this to a string that is the name of the block device.
4491 - FAT_ENV_DEV_AND_PART:
4493 Define this to a string to specify the partition of the device. It can
4496 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4497 - "D:P": device D partition P. Error occurs if device D has no
4500 - "D" or "D:": device D partition 1 if device D has partition
4501 table, or the whole device D if has no partition
4503 - "D:auto": first partition in device D with bootable flag set.
4504 If none, first valid partition in device D. If no
4505 partition table then means device D.
4509 It's a string of the FAT file name. This file use to store the
4513 This should be defined. Otherwise it cannot save the environment file.
4515 - CONFIG_ENV_IS_IN_MMC:
4517 Define this if you have an MMC device which you want to use for the
4520 - CONFIG_SYS_MMC_ENV_DEV:
4522 Specifies which MMC device the environment is stored in.
4524 - CONFIG_SYS_MMC_ENV_PART (optional):
4526 Specifies which MMC partition the environment is stored in. If not
4527 set, defaults to partition 0, the user area. Common values might be
4528 1 (first MMC boot partition), 2 (second MMC boot partition).
4530 - CONFIG_ENV_OFFSET:
4533 These two #defines specify the offset and size of the environment
4534 area within the specified MMC device.
4536 If offset is positive (the usual case), it is treated as relative to
4537 the start of the MMC partition. If offset is negative, it is treated
4538 as relative to the end of the MMC partition. This can be useful if
4539 your board may be fitted with different MMC devices, which have
4540 different sizes for the MMC partitions, and you always want the
4541 environment placed at the very end of the partition, to leave the
4542 maximum possible space before it, to store other data.
4544 These two values are in units of bytes, but must be aligned to an
4545 MMC sector boundary.
4547 - CONFIG_ENV_OFFSET_REDUND (optional):
4549 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4550 hold a redundant copy of the environment data. This provides a
4551 valid backup copy in case the other copy is corrupted, e.g. due
4552 to a power failure during a "saveenv" operation.
4554 This value may also be positive or negative; this is handled in the
4555 same way as CONFIG_ENV_OFFSET.
4557 This value is also in units of bytes, but must also be aligned to
4558 an MMC sector boundary.
4560 - CONFIG_ENV_SIZE_REDUND (optional):
4562 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4563 set. If this value is set, it must be set to the same value as
4566 - CONFIG_SYS_SPI_INIT_OFFSET
4568 Defines offset to the initial SPI buffer area in DPRAM. The
4569 area is used at an early stage (ROM part) if the environment
4570 is configured to reside in the SPI EEPROM: We need a 520 byte
4571 scratch DPRAM area. It is used between the two initialization
4572 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4573 to be a good choice since it makes it far enough from the
4574 start of the data area as well as from the stack pointer.
4576 Please note that the environment is read-only until the monitor
4577 has been relocated to RAM and a RAM copy of the environment has been
4578 created; also, when using EEPROM you will have to use getenv_f()
4579 until then to read environment variables.
4581 The environment is protected by a CRC32 checksum. Before the monitor
4582 is relocated into RAM, as a result of a bad CRC you will be working
4583 with the compiled-in default environment - *silently*!!! [This is
4584 necessary, because the first environment variable we need is the
4585 "baudrate" setting for the console - if we have a bad CRC, we don't
4586 have any device yet where we could complain.]
4588 Note: once the monitor has been relocated, then it will complain if
4589 the default environment is used; a new CRC is computed as soon as you
4590 use the "saveenv" command to store a valid environment.
4592 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4593 Echo the inverted Ethernet link state to the fault LED.
4595 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4596 also needs to be defined.
4598 - CONFIG_SYS_FAULT_MII_ADDR:
4599 MII address of the PHY to check for the Ethernet link state.
4601 - CONFIG_NS16550_MIN_FUNCTIONS:
4602 Define this if you desire to only have use of the NS16550_init
4603 and NS16550_putc functions for the serial driver located at
4604 drivers/serial/ns16550.c. This option is useful for saving
4605 space for already greatly restricted images, including but not
4606 limited to NAND_SPL configurations.
4608 - CONFIG_DISPLAY_BOARDINFO
4609 Display information about the board that U-Boot is running on
4610 when U-Boot starts up. The board function checkboard() is called
4613 - CONFIG_DISPLAY_BOARDINFO_LATE
4614 Similar to the previous option, but display this information
4615 later, once stdio is running and output goes to the LCD, if
4618 - CONFIG_BOARD_SIZE_LIMIT:
4619 Maximum size of the U-Boot image. When defined, the
4620 build system checks that the actual size does not
4623 Low Level (hardware related) configuration options:
4624 ---------------------------------------------------
4626 - CONFIG_SYS_CACHELINE_SIZE:
4627 Cache Line Size of the CPU.
4629 - CONFIG_SYS_DEFAULT_IMMR:
4630 Default address of the IMMR after system reset.
4632 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4633 and RPXsuper) to be able to adjust the position of
4634 the IMMR register after a reset.
4636 - CONFIG_SYS_CCSRBAR_DEFAULT:
4637 Default (power-on reset) physical address of CCSR on Freescale
4640 - CONFIG_SYS_CCSRBAR:
4641 Virtual address of CCSR. On a 32-bit build, this is typically
4642 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4644 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4645 for cross-platform code that uses that macro instead.
4647 - CONFIG_SYS_CCSRBAR_PHYS:
4648 Physical address of CCSR. CCSR can be relocated to a new
4649 physical address, if desired. In this case, this macro should
4650 be set to that address. Otherwise, it should be set to the
4651 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4652 is typically relocated on 36-bit builds. It is recommended
4653 that this macro be defined via the _HIGH and _LOW macros:
4655 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4656 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4658 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4659 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4660 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4661 used in assembly code, so it must not contain typecasts or
4662 integer size suffixes (e.g. "ULL").
4664 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4665 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4666 used in assembly code, so it must not contain typecasts or
4667 integer size suffixes (e.g. "ULL").
4669 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4670 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4671 forced to a value that ensures that CCSR is not relocated.
4673 - Floppy Disk Support:
4674 CONFIG_SYS_FDC_DRIVE_NUMBER
4676 the default drive number (default value 0)
4678 CONFIG_SYS_ISA_IO_STRIDE
4680 defines the spacing between FDC chipset registers
4683 CONFIG_SYS_ISA_IO_OFFSET
4685 defines the offset of register from address. It
4686 depends on which part of the data bus is connected to
4687 the FDC chipset. (default value 0)
4689 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4690 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4693 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4694 fdc_hw_init() is called at the beginning of the FDC
4695 setup. fdc_hw_init() must be provided by the board
4696 source code. It is used to make hardware-dependent
4700 Most IDE controllers were designed to be connected with PCI
4701 interface. Only few of them were designed for AHB interface.
4702 When software is doing ATA command and data transfer to
4703 IDE devices through IDE-AHB controller, some additional
4704 registers accessing to these kind of IDE-AHB controller
4707 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4708 DO NOT CHANGE unless you know exactly what you're
4709 doing! (11-4) [MPC8xx/82xx systems only]
4711 - CONFIG_SYS_INIT_RAM_ADDR:
4713 Start address of memory area that can be used for
4714 initial data and stack; please note that this must be
4715 writable memory that is working WITHOUT special
4716 initialization, i. e. you CANNOT use normal RAM which
4717 will become available only after programming the
4718 memory controller and running certain initialization
4721 U-Boot uses the following memory types:
4722 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4723 - MPC824X: data cache
4724 - PPC4xx: data cache
4726 - CONFIG_SYS_GBL_DATA_OFFSET:
4728 Offset of the initial data structure in the memory
4729 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4730 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4731 data is located at the end of the available space
4732 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4733 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4734 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4735 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4738 On the MPC824X (or other systems that use the data
4739 cache for initial memory) the address chosen for
4740 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4741 point to an otherwise UNUSED address space between
4742 the top of RAM and the start of the PCI space.
4744 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4746 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4748 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4750 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4752 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4754 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4756 - CONFIG_SYS_OR_TIMING_SDRAM:
4759 - CONFIG_SYS_MAMR_PTA:
4760 periodic timer for refresh
4762 - CONFIG_SYS_DER: Debug Event Register (37-47)
4764 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4765 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4766 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4767 CONFIG_SYS_BR1_PRELIM:
4768 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4770 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4771 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4772 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4773 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4775 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4776 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4777 Machine Mode Register and Memory Periodic Timer
4778 Prescaler definitions (SDRAM timing)
4780 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4781 enable I2C microcode relocation patch (MPC8xx);
4782 define relocation offset in DPRAM [DSP2]
4784 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4785 enable SMC microcode relocation patch (MPC8xx);
4786 define relocation offset in DPRAM [SMC1]
4788 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4789 enable SPI microcode relocation patch (MPC8xx);
4790 define relocation offset in DPRAM [SCC4]
4792 - CONFIG_SYS_USE_OSCCLK:
4793 Use OSCM clock mode on MBX8xx board. Be careful,
4794 wrong setting might damage your board. Read
4795 doc/README.MBX before setting this variable!
4797 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4798 Offset of the bootmode word in DPRAM used by post
4799 (Power On Self Tests). This definition overrides
4800 #define'd default value in commproc.h resp.
4803 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4804 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4805 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4806 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4807 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4808 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4809 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4810 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4811 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4813 - CONFIG_PCI_DISABLE_PCIE:
4814 Disable PCI-Express on systems where it is supported but not
4817 - CONFIG_PCI_ENUM_ONLY
4818 Only scan through and get the devices on the buses.
4819 Don't do any setup work, presumably because someone or
4820 something has already done it, and we don't need to do it
4821 a second time. Useful for platforms that are pre-booted
4822 by coreboot or similar.
4824 - CONFIG_PCI_INDIRECT_BRIDGE:
4825 Enable support for indirect PCI bridges.
4828 Chip has SRIO or not
4831 Board has SRIO 1 port available
4834 Board has SRIO 2 port available
4836 - CONFIG_SRIO_PCIE_BOOT_MASTER
4837 Board can support master function for Boot from SRIO and PCIE
4839 - CONFIG_SYS_SRIOn_MEM_VIRT:
4840 Virtual Address of SRIO port 'n' memory region
4842 - CONFIG_SYS_SRIOn_MEM_PHYS:
4843 Physical Address of SRIO port 'n' memory region
4845 - CONFIG_SYS_SRIOn_MEM_SIZE:
4846 Size of SRIO port 'n' memory region
4848 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4849 Defined to tell the NAND controller that the NAND chip is using
4851 Not all NAND drivers use this symbol.
4852 Example of drivers that use it:
4853 - drivers/mtd/nand/ndfc.c
4854 - drivers/mtd/nand/mxc_nand.c
4856 - CONFIG_SYS_NDFC_EBC0_CFG
4857 Sets the EBC0_CFG register for the NDFC. If not defined
4858 a default value will be used.
4861 Get DDR timing information from an I2C EEPROM. Common
4862 with pluggable memory modules such as SODIMMs
4865 I2C address of the SPD EEPROM
4867 - CONFIG_SYS_SPD_BUS_NUM
4868 If SPD EEPROM is on an I2C bus other than the first
4869 one, specify here. Note that the value must resolve
4870 to something your driver can deal with.
4872 - CONFIG_SYS_DDR_RAW_TIMING
4873 Get DDR timing information from other than SPD. Common with
4874 soldered DDR chips onboard without SPD. DDR raw timing
4875 parameters are extracted from datasheet and hard-coded into
4876 header files or board specific files.
4878 - CONFIG_FSL_DDR_INTERACTIVE
4879 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4881 - CONFIG_FSL_DDR_SYNC_REFRESH
4882 Enable sync of refresh for multiple controllers.
4884 - CONFIG_FSL_DDR_BIST
4885 Enable built-in memory test for Freescale DDR controllers.
4887 - CONFIG_SYS_83XX_DDR_USES_CS0
4888 Only for 83xx systems. If specified, then DDR should
4889 be configured using CS0 and CS1 instead of CS2 and CS3.
4891 - CONFIG_ETHER_ON_FEC[12]
4892 Define to enable FEC[12] on a 8xx series processor.
4894 - CONFIG_FEC[12]_PHY
4895 Define to the hardcoded PHY address which corresponds
4896 to the given FEC; i. e.
4897 #define CONFIG_FEC1_PHY 4
4898 means that the PHY with address 4 is connected to FEC1
4900 When set to -1, means to probe for first available.
4902 - CONFIG_FEC[12]_PHY_NORXERR
4903 The PHY does not have a RXERR line (RMII only).
4904 (so program the FEC to ignore it).
4907 Enable RMII mode for all FECs.
4908 Note that this is a global option, we can't
4909 have one FEC in standard MII mode and another in RMII mode.
4911 - CONFIG_CRC32_VERIFY
4912 Add a verify option to the crc32 command.
4915 => crc32 -v <address> <count> <crc32>
4917 Where address/count indicate a memory area
4918 and crc32 is the correct crc32 which the
4922 Add the "loopw" memory command. This only takes effect if
4923 the memory commands are activated globally (CONFIG_CMD_MEM).
4926 Add the "mdc" and "mwc" memory commands. These are cyclic
4931 This command will print 4 bytes (10,11,12,13) each 500 ms.
4933 => mwc.l 100 12345678 10
4934 This command will write 12345678 to address 100 all 10 ms.
4936 This only takes effect if the memory commands are activated
4937 globally (CONFIG_CMD_MEM).
4939 - CONFIG_SKIP_LOWLEVEL_INIT
4940 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4941 low level initializations (like setting up the memory
4942 controller) are omitted and/or U-Boot does not
4943 relocate itself into RAM.
4945 Normally this variable MUST NOT be defined. The only
4946 exception is when U-Boot is loaded (to RAM) by some
4947 other boot loader or by a debugger which performs
4948 these initializations itself.
4951 Modifies the behaviour of start.S when compiling a loader
4952 that is executed before the actual U-Boot. E.g. when
4953 compiling a NAND SPL.
4956 Modifies the behaviour of start.S when compiling a loader
4957 that is executed after the SPL and before the actual U-Boot.
4958 It is loaded by the SPL.
4960 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4961 Only for 85xx systems. If this variable is specified, the section
4962 .resetvec is not kept and the section .bootpg is placed in the
4963 previous 4k of the .text section.
4965 - CONFIG_ARCH_MAP_SYSMEM
4966 Generally U-Boot (and in particular the md command) uses
4967 effective address. It is therefore not necessary to regard
4968 U-Boot address as virtual addresses that need to be translated
4969 to physical addresses. However, sandbox requires this, since
4970 it maintains its own little RAM buffer which contains all
4971 addressable memory. This option causes some memory accesses
4972 to be mapped through map_sysmem() / unmap_sysmem().
4974 - CONFIG_USE_ARCH_MEMCPY
4975 CONFIG_USE_ARCH_MEMSET
4976 If these options are used a optimized version of memcpy/memset will
4977 be used if available. These functions may be faster under some
4978 conditions but may increase the binary size.
4980 - CONFIG_X86_RESET_VECTOR
4981 If defined, the x86 reset vector code is included. This is not
4982 needed when U-Boot is running from Coreboot.
4985 Defines the MPU clock speed (in MHz).
4987 NOTE : currently only supported on AM335x platforms.
4989 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4990 Enables the RTC32K OSC on AM33xx based plattforms
4992 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4993 Option to disable subpage write in NAND driver
4994 driver that uses this:
4995 drivers/mtd/nand/davinci_nand.c
4997 Freescale QE/FMAN Firmware Support:
4998 -----------------------------------
5000 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5001 loading of "firmware", which is encoded in the QE firmware binary format.
5002 This firmware often needs to be loaded during U-Boot booting, so macros
5003 are used to identify the storage device (NOR flash, SPI, etc) and the address
5006 - CONFIG_SYS_FMAN_FW_ADDR
5007 The address in the storage device where the FMAN microcode is located. The
5008 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5011 - CONFIG_SYS_QE_FW_ADDR
5012 The address in the storage device where the QE microcode is located. The
5013 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5016 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5017 The maximum possible size of the firmware. The firmware binary format
5018 has a field that specifies the actual size of the firmware, but it
5019 might not be possible to read any part of the firmware unless some
5020 local storage is allocated to hold the entire firmware first.
5022 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5023 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5024 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5025 virtual address in NOR flash.
5027 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5028 Specifies that QE/FMAN firmware is located in NAND flash.
5029 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5031 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5032 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5033 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5035 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5036 Specifies that QE/FMAN firmware is located on the primary SPI
5037 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5039 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5040 Specifies that QE/FMAN firmware is located in the remote (master)
5041 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5042 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5043 window->master inbound window->master LAW->the ucode address in
5044 master's memory space.
5046 Freescale Layerscape Management Complex Firmware Support:
5047 ---------------------------------------------------------
5048 The Freescale Layerscape Management Complex (MC) supports the loading of
5050 This firmware often needs to be loaded during U-Boot booting, so macros
5051 are used to identify the storage device (NOR flash, SPI, etc) and the address
5054 - CONFIG_FSL_MC_ENET
5055 Enable the MC driver for Layerscape SoCs.
5057 - CONFIG_SYS_LS_MC_FW_ADDR
5058 The address in the storage device where the firmware is located. The
5059 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5062 - CONFIG_SYS_LS_MC_FW_LENGTH
5063 The maximum possible size of the firmware. The firmware binary format
5064 has a field that specifies the actual size of the firmware, but it
5065 might not be possible to read any part of the firmware unless some
5066 local storage is allocated to hold the entire firmware first.
5068 - CONFIG_SYS_LS_MC_FW_IN_NOR
5069 Specifies that MC firmware is located in NOR flash, mapped as
5070 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5071 virtual address in NOR flash.
5073 Building the Software:
5074 ======================
5076 Building U-Boot has been tested in several native build environments
5077 and in many different cross environments. Of course we cannot support
5078 all possibly existing versions of cross development tools in all
5079 (potentially obsolete) versions. In case of tool chain problems we
5080 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5081 which is extensively used to build and test U-Boot.
5083 If you are not using a native environment, it is assumed that you
5084 have GNU cross compiling tools available in your path. In this case,
5085 you must set the environment variable CROSS_COMPILE in your shell.
5086 Note that no changes to the Makefile or any other source files are
5087 necessary. For example using the ELDK on a 4xx CPU, please enter:
5089 $ CROSS_COMPILE=ppc_4xx-
5090 $ export CROSS_COMPILE
5092 Note: If you wish to generate Windows versions of the utilities in
5093 the tools directory you can use the MinGW toolchain
5094 (http://www.mingw.org). Set your HOST tools to the MinGW
5095 toolchain and execute 'make tools'. For example:
5097 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5099 Binaries such as tools/mkimage.exe will be created which can
5100 be executed on computers running Windows.
5102 U-Boot is intended to be simple to build. After installing the
5103 sources you must configure U-Boot for one specific board type. This
5108 where "NAME_defconfig" is the name of one of the existing configu-
5109 rations; see boards.cfg for supported names.
5111 Note: for some board special configuration names may exist; check if
5112 additional information is available from the board vendor; for
5113 instance, the TQM823L systems are available without (standard)
5114 or with LCD support. You can select such additional "features"
5115 when choosing the configuration, i. e.
5117 make TQM823L_defconfig
5118 - will configure for a plain TQM823L, i. e. no LCD support
5120 make TQM823L_LCD_defconfig
5121 - will configure for a TQM823L with U-Boot console on LCD
5126 Finally, type "make all", and you should get some working U-Boot
5127 images ready for download to / installation on your system:
5129 - "u-boot.bin" is a raw binary image
5130 - "u-boot" is an image in ELF binary format
5131 - "u-boot.srec" is in Motorola S-Record format
5133 By default the build is performed locally and the objects are saved
5134 in the source directory. One of the two methods can be used to change
5135 this behavior and build U-Boot to some external directory:
5137 1. Add O= to the make command line invocations:
5139 make O=/tmp/build distclean
5140 make O=/tmp/build NAME_defconfig
5141 make O=/tmp/build all
5143 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5145 export KBUILD_OUTPUT=/tmp/build
5150 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5154 Please be aware that the Makefiles assume you are using GNU make, so
5155 for instance on NetBSD you might need to use "gmake" instead of
5159 If the system board that you have is not listed, then you will need
5160 to port U-Boot to your hardware platform. To do this, follow these
5163 1. Add a new configuration option for your board to the toplevel
5164 "boards.cfg" file, using the existing entries as examples.
5165 Follow the instructions there to keep the boards in order.
5166 2. Create a new directory to hold your board specific code. Add any
5167 files you need. In your board directory, you will need at least
5168 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5169 3. Create a new configuration file "include/configs/<board>.h" for
5171 3. If you're porting U-Boot to a new CPU, then also create a new
5172 directory to hold your CPU specific code. Add any files you need.
5173 4. Run "make <board>_defconfig" with your new name.
5174 5. Type "make", and you should get a working "u-boot.srec" file
5175 to be installed on your target system.
5176 6. Debug and solve any problems that might arise.
5177 [Of course, this last step is much harder than it sounds.]
5180 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5181 ==============================================================
5183 If you have modified U-Boot sources (for instance added a new board
5184 or support for new devices, a new CPU, etc.) you are expected to
5185 provide feedback to the other developers. The feedback normally takes
5186 the form of a "patch", i. e. a context diff against a certain (latest
5187 official or latest in the git repository) version of U-Boot sources.
5189 But before you submit such a patch, please verify that your modifi-
5190 cation did not break existing code. At least make sure that *ALL* of
5191 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5192 just run the "MAKEALL" script, which will configure and build U-Boot
5193 for ALL supported system. Be warned, this will take a while. You can
5194 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5195 environment variable to the script, i. e. to use the ELDK cross tools
5198 CROSS_COMPILE=ppc_8xx- MAKEALL
5200 or to build on a native PowerPC system you can type
5202 CROSS_COMPILE=' ' MAKEALL
5204 When using the MAKEALL script, the default behaviour is to build
5205 U-Boot in the source directory. This location can be changed by
5206 setting the BUILD_DIR environment variable. Also, for each target
5207 built, the MAKEALL script saves two log files (<target>.ERR and
5208 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5209 location can be changed by setting the MAKEALL_LOGDIR environment
5210 variable. For example:
5212 export BUILD_DIR=/tmp/build
5213 export MAKEALL_LOGDIR=/tmp/log
5214 CROSS_COMPILE=ppc_8xx- MAKEALL
5216 With the above settings build objects are saved in the /tmp/build,
5217 log files are saved in the /tmp/log and the source tree remains clean
5218 during the whole build process.
5221 See also "U-Boot Porting Guide" below.
5224 Monitor Commands - Overview:
5225 ============================
5227 go - start application at address 'addr'
5228 run - run commands in an environment variable
5229 bootm - boot application image from memory
5230 bootp - boot image via network using BootP/TFTP protocol
5231 bootz - boot zImage from memory
5232 tftpboot- boot image via network using TFTP protocol
5233 and env variables "ipaddr" and "serverip"
5234 (and eventually "gatewayip")
5235 tftpput - upload a file via network using TFTP protocol
5236 rarpboot- boot image via network using RARP/TFTP protocol
5237 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5238 loads - load S-Record file over serial line
5239 loadb - load binary file over serial line (kermit mode)
5241 mm - memory modify (auto-incrementing)
5242 nm - memory modify (constant address)
5243 mw - memory write (fill)
5245 cmp - memory compare
5246 crc32 - checksum calculation
5247 i2c - I2C sub-system
5248 sspi - SPI utility commands
5249 base - print or set address offset
5250 printenv- print environment variables
5251 setenv - set environment variables
5252 saveenv - save environment variables to persistent storage
5253 protect - enable or disable FLASH write protection
5254 erase - erase FLASH memory
5255 flinfo - print FLASH memory information
5256 nand - NAND memory operations (see doc/README.nand)
5257 bdinfo - print Board Info structure
5258 iminfo - print header information for application image
5259 coninfo - print console devices and informations
5260 ide - IDE sub-system
5261 loop - infinite loop on address range
5262 loopw - infinite write loop on address range
5263 mtest - simple RAM test
5264 icache - enable or disable instruction cache
5265 dcache - enable or disable data cache
5266 reset - Perform RESET of the CPU
5267 echo - echo args to console
5268 version - print monitor version
5269 help - print online help
5270 ? - alias for 'help'
5273 Monitor Commands - Detailed Description:
5274 ========================================
5278 For now: just type "help <command>".
5281 Environment Variables:
5282 ======================
5284 U-Boot supports user configuration using Environment Variables which
5285 can be made persistent by saving to Flash memory.
5287 Environment Variables are set using "setenv", printed using
5288 "printenv", and saved to Flash using "saveenv". Using "setenv"
5289 without a value can be used to delete a variable from the
5290 environment. As long as you don't save the environment you are
5291 working with an in-memory copy. In case the Flash area containing the
5292 environment is erased by accident, a default environment is provided.
5294 Some configuration options can be set using Environment Variables.
5296 List of environment variables (most likely not complete):
5298 baudrate - see CONFIG_BAUDRATE
5300 bootdelay - see CONFIG_BOOTDELAY
5302 bootcmd - see CONFIG_BOOTCOMMAND
5304 bootargs - Boot arguments when booting an RTOS image
5306 bootfile - Name of the image to load with TFTP
5308 bootm_low - Memory range available for image processing in the bootm
5309 command can be restricted. This variable is given as
5310 a hexadecimal number and defines lowest address allowed
5311 for use by the bootm command. See also "bootm_size"
5312 environment variable. Address defined by "bootm_low" is
5313 also the base of the initial memory mapping for the Linux
5314 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5317 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5318 This variable is given as a hexadecimal number and it
5319 defines the size of the memory region starting at base
5320 address bootm_low that is accessible by the Linux kernel
5321 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5322 as the default value if it is defined, and bootm_size is
5325 bootm_size - Memory range available for image processing in the bootm
5326 command can be restricted. This variable is given as
5327 a hexadecimal number and defines the size of the region
5328 allowed for use by the bootm command. See also "bootm_low"
5329 environment variable.
5331 updatefile - Location of the software update file on a TFTP server, used
5332 by the automatic software update feature. Please refer to
5333 documentation in doc/README.update for more details.
5335 autoload - if set to "no" (any string beginning with 'n'),
5336 "bootp" will just load perform a lookup of the
5337 configuration from the BOOTP server, but not try to
5338 load any image using TFTP
5340 autostart - if set to "yes", an image loaded using the "bootp",
5341 "rarpboot", "tftpboot" or "diskboot" commands will
5342 be automatically started (by internally calling
5345 If set to "no", a standalone image passed to the
5346 "bootm" command will be copied to the load address
5347 (and eventually uncompressed), but NOT be started.
5348 This can be used to load and uncompress arbitrary
5351 fdt_high - if set this restricts the maximum address that the
5352 flattened device tree will be copied into upon boot.
5353 For example, if you have a system with 1 GB memory
5354 at physical address 0x10000000, while Linux kernel
5355 only recognizes the first 704 MB as low memory, you
5356 may need to set fdt_high as 0x3C000000 to have the
5357 device tree blob be copied to the maximum address
5358 of the 704 MB low memory, so that Linux kernel can
5359 access it during the boot procedure.
5361 If this is set to the special value 0xFFFFFFFF then
5362 the fdt will not be copied at all on boot. For this
5363 to work it must reside in writable memory, have
5364 sufficient padding on the end of it for u-boot to
5365 add the information it needs into it, and the memory
5366 must be accessible by the kernel.
5368 fdtcontroladdr- if set this is the address of the control flattened
5369 device tree used by U-Boot when CONFIG_OF_CONTROL is
5372 i2cfast - (PPC405GP|PPC405EP only)
5373 if set to 'y' configures Linux I2C driver for fast
5374 mode (400kHZ). This environment variable is used in
5375 initialization code. So, for changes to be effective
5376 it must be saved and board must be reset.
5378 initrd_high - restrict positioning of initrd images:
5379 If this variable is not set, initrd images will be
5380 copied to the highest possible address in RAM; this
5381 is usually what you want since it allows for
5382 maximum initrd size. If for some reason you want to
5383 make sure that the initrd image is loaded below the
5384 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5385 variable to a value of "no" or "off" or "0".
5386 Alternatively, you can set it to a maximum upper
5387 address to use (U-Boot will still check that it
5388 does not overwrite the U-Boot stack and data).
5390 For instance, when you have a system with 16 MB
5391 RAM, and want to reserve 4 MB from use by Linux,
5392 you can do this by adding "mem=12M" to the value of
5393 the "bootargs" variable. However, now you must make
5394 sure that the initrd image is placed in the first
5395 12 MB as well - this can be done with
5397 setenv initrd_high 00c00000
5399 If you set initrd_high to 0xFFFFFFFF, this is an
5400 indication to U-Boot that all addresses are legal
5401 for the Linux kernel, including addresses in flash
5402 memory. In this case U-Boot will NOT COPY the
5403 ramdisk at all. This may be useful to reduce the
5404 boot time on your system, but requires that this
5405 feature is supported by your Linux kernel.
5407 ipaddr - IP address; needed for tftpboot command
5409 loadaddr - Default load address for commands like "bootp",
5410 "rarpboot", "tftpboot", "loadb" or "diskboot"
5412 loads_echo - see CONFIG_LOADS_ECHO
5414 serverip - TFTP server IP address; needed for tftpboot command
5416 bootretry - see CONFIG_BOOT_RETRY_TIME
5418 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5420 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5422 ethprime - controls which interface is used first.
5424 ethact - controls which interface is currently active.
5425 For example you can do the following
5427 => setenv ethact FEC
5428 => ping 192.168.0.1 # traffic sent on FEC
5429 => setenv ethact SCC
5430 => ping 10.0.0.1 # traffic sent on SCC
5432 ethrotate - When set to "no" U-Boot does not go through all
5433 available network interfaces.
5434 It just stays at the currently selected interface.
5436 netretry - When set to "no" each network operation will
5437 either succeed or fail without retrying.
5438 When set to "once" the network operation will
5439 fail when all the available network interfaces
5440 are tried once without success.
5441 Useful on scripts which control the retry operation
5444 npe_ucode - set load address for the NPE microcode
5446 silent_linux - If set then Linux will be told to boot silently, by
5447 changing the console to be empty. If "yes" it will be
5448 made silent. If "no" it will not be made silent. If
5449 unset, then it will be made silent if the U-Boot console
5452 tftpsrcport - If this is set, the value is used for TFTP's
5455 tftpdstport - If this is set, the value is used for TFTP's UDP
5456 destination port instead of the Well Know Port 69.
5458 tftpblocksize - Block size to use for TFTP transfers; if not set,
5459 we use the TFTP server's default block size
5461 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5462 seconds, minimum value is 1000 = 1 second). Defines
5463 when a packet is considered to be lost so it has to
5464 be retransmitted. The default is 5000 = 5 seconds.
5465 Lowering this value may make downloads succeed
5466 faster in networks with high packet loss rates or
5467 with unreliable TFTP servers.
5469 vlan - When set to a value < 4095 the traffic over
5470 Ethernet is encapsulated/received over 802.1q
5473 The following image location variables contain the location of images
5474 used in booting. The "Image" column gives the role of the image and is
5475 not an environment variable name. The other columns are environment
5476 variable names. "File Name" gives the name of the file on a TFTP
5477 server, "RAM Address" gives the location in RAM the image will be
5478 loaded to, and "Flash Location" gives the image's address in NOR
5479 flash or offset in NAND flash.
5481 *Note* - these variables don't have to be defined for all boards, some
5482 boards currenlty use other variables for these purposes, and some
5483 boards use these variables for other purposes.
5485 Image File Name RAM Address Flash Location
5486 ----- --------- ----------- --------------
5487 u-boot u-boot u-boot_addr_r u-boot_addr
5488 Linux kernel bootfile kernel_addr_r kernel_addr
5489 device tree blob fdtfile fdt_addr_r fdt_addr
5490 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5492 The following environment variables may be used and automatically
5493 updated by the network boot commands ("bootp" and "rarpboot"),
5494 depending the information provided by your boot server:
5496 bootfile - see above
5497 dnsip - IP address of your Domain Name Server
5498 dnsip2 - IP address of your secondary Domain Name Server
5499 gatewayip - IP address of the Gateway (Router) to use
5500 hostname - Target hostname
5502 netmask - Subnet Mask
5503 rootpath - Pathname of the root filesystem on the NFS server
5504 serverip - see above
5507 There are two special Environment Variables:
5509 serial# - contains hardware identification information such
5510 as type string and/or serial number
5511 ethaddr - Ethernet address
5513 These variables can be set only once (usually during manufacturing of
5514 the board). U-Boot refuses to delete or overwrite these variables
5515 once they have been set once.
5518 Further special Environment Variables:
5520 ver - Contains the U-Boot version string as printed
5521 with the "version" command. This variable is
5522 readonly (see CONFIG_VERSION_VARIABLE).
5525 Please note that changes to some configuration parameters may take
5526 only effect after the next boot (yes, that's just like Windoze :-).
5529 Callback functions for environment variables:
5530 ---------------------------------------------
5532 For some environment variables, the behavior of u-boot needs to change
5533 when their values are changed. This functionality allows functions to
5534 be associated with arbitrary variables. On creation, overwrite, or
5535 deletion, the callback will provide the opportunity for some side
5536 effect to happen or for the change to be rejected.
5538 The callbacks are named and associated with a function using the
5539 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5541 These callbacks are associated with variables in one of two ways. The
5542 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5543 in the board configuration to a string that defines a list of
5544 associations. The list must be in the following format:
5546 entry = variable_name[:callback_name]
5549 If the callback name is not specified, then the callback is deleted.
5550 Spaces are also allowed anywhere in the list.
5552 Callbacks can also be associated by defining the ".callbacks" variable
5553 with the same list format above. Any association in ".callbacks" will
5554 override any association in the static list. You can define
5555 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5556 ".callbacks" environment variable in the default or embedded environment.
5559 Command Line Parsing:
5560 =====================
5562 There are two different command line parsers available with U-Boot:
5563 the old "simple" one, and the much more powerful "hush" shell:
5565 Old, simple command line parser:
5566 --------------------------------
5568 - supports environment variables (through setenv / saveenv commands)
5569 - several commands on one line, separated by ';'
5570 - variable substitution using "... ${name} ..." syntax
5571 - special characters ('$', ';') can be escaped by prefixing with '\',
5573 setenv bootcmd bootm \${address}
5574 - You can also escape text by enclosing in single apostrophes, for example:
5575 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5580 - similar to Bourne shell, with control structures like
5581 if...then...else...fi, for...do...done; while...do...done,
5582 until...do...done, ...
5583 - supports environment ("global") variables (through setenv / saveenv
5584 commands) and local shell variables (through standard shell syntax
5585 "name=value"); only environment variables can be used with "run"
5591 (1) If a command line (or an environment variable executed by a "run"
5592 command) contains several commands separated by semicolon, and
5593 one of these commands fails, then the remaining commands will be
5596 (2) If you execute several variables with one call to run (i. e.
5597 calling run with a list of variables as arguments), any failing
5598 command will cause "run" to terminate, i. e. the remaining
5599 variables are not executed.
5601 Note for Redundant Ethernet Interfaces:
5602 =======================================
5604 Some boards come with redundant Ethernet interfaces; U-Boot supports
5605 such configurations and is capable of automatic selection of a
5606 "working" interface when needed. MAC assignment works as follows:
5608 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5609 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5610 "eth1addr" (=>eth1), "eth2addr", ...
5612 If the network interface stores some valid MAC address (for instance
5613 in SROM), this is used as default address if there is NO correspon-
5614 ding setting in the environment; if the corresponding environment
5615 variable is set, this overrides the settings in the card; that means:
5617 o If the SROM has a valid MAC address, and there is no address in the
5618 environment, the SROM's address is used.
5620 o If there is no valid address in the SROM, and a definition in the
5621 environment exists, then the value from the environment variable is
5624 o If both the SROM and the environment contain a MAC address, and
5625 both addresses are the same, this MAC address is used.
5627 o If both the SROM and the environment contain a MAC address, and the
5628 addresses differ, the value from the environment is used and a
5631 o If neither SROM nor the environment contain a MAC address, an error
5634 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5635 will be programmed into hardware as part of the initialization process. This
5636 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5637 The naming convention is as follows:
5638 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5643 U-Boot is capable of booting (and performing other auxiliary operations on)
5644 images in two formats:
5646 New uImage format (FIT)
5647 -----------------------
5649 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5650 to Flattened Device Tree). It allows the use of images with multiple
5651 components (several kernels, ramdisks, etc.), with contents protected by
5652 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5658 Old image format is based on binary files which can be basically anything,
5659 preceded by a special header; see the definitions in include/image.h for
5660 details; basically, the header defines the following image properties:
5662 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5663 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5664 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5665 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5667 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5668 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5669 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5670 * Compression Type (uncompressed, gzip, bzip2)
5676 The header is marked by a special Magic Number, and both the header
5677 and the data portions of the image are secured against corruption by
5684 Although U-Boot should support any OS or standalone application
5685 easily, the main focus has always been on Linux during the design of
5688 U-Boot includes many features that so far have been part of some
5689 special "boot loader" code within the Linux kernel. Also, any
5690 "initrd" images to be used are no longer part of one big Linux image;
5691 instead, kernel and "initrd" are separate images. This implementation
5692 serves several purposes:
5694 - the same features can be used for other OS or standalone
5695 applications (for instance: using compressed images to reduce the
5696 Flash memory footprint)
5698 - it becomes much easier to port new Linux kernel versions because
5699 lots of low-level, hardware dependent stuff are done by U-Boot
5701 - the same Linux kernel image can now be used with different "initrd"
5702 images; of course this also means that different kernel images can
5703 be run with the same "initrd". This makes testing easier (you don't
5704 have to build a new "zImage.initrd" Linux image when you just
5705 change a file in your "initrd"). Also, a field-upgrade of the
5706 software is easier now.
5712 Porting Linux to U-Boot based systems:
5713 ---------------------------------------
5715 U-Boot cannot save you from doing all the necessary modifications to
5716 configure the Linux device drivers for use with your target hardware
5717 (no, we don't intend to provide a full virtual machine interface to
5720 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5722 Just make sure your machine specific header file (for instance
5723 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5724 Information structure as we define in include/asm-<arch>/u-boot.h,
5725 and make sure that your definition of IMAP_ADDR uses the same value
5726 as your U-Boot configuration in CONFIG_SYS_IMMR.
5728 Note that U-Boot now has a driver model, a unified model for drivers.
5729 If you are adding a new driver, plumb it into driver model. If there
5730 is no uclass available, you are encouraged to create one. See
5734 Configuring the Linux kernel:
5735 -----------------------------
5737 No specific requirements for U-Boot. Make sure you have some root
5738 device (initial ramdisk, NFS) for your target system.
5741 Building a Linux Image:
5742 -----------------------
5744 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5745 not used. If you use recent kernel source, a new build target
5746 "uImage" will exist which automatically builds an image usable by
5747 U-Boot. Most older kernels also have support for a "pImage" target,
5748 which was introduced for our predecessor project PPCBoot and uses a
5749 100% compatible format.
5753 make TQM850L_defconfig
5758 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5759 encapsulate a compressed Linux kernel image with header information,
5760 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5762 * build a standard "vmlinux" kernel image (in ELF binary format):
5764 * convert the kernel into a raw binary image:
5766 ${CROSS_COMPILE}-objcopy -O binary \
5767 -R .note -R .comment \
5768 -S vmlinux linux.bin
5770 * compress the binary image:
5774 * package compressed binary image for U-Boot:
5776 mkimage -A ppc -O linux -T kernel -C gzip \
5777 -a 0 -e 0 -n "Linux Kernel Image" \
5778 -d linux.bin.gz uImage
5781 The "mkimage" tool can also be used to create ramdisk images for use
5782 with U-Boot, either separated from the Linux kernel image, or
5783 combined into one file. "mkimage" encapsulates the images with a 64
5784 byte header containing information about target architecture,
5785 operating system, image type, compression method, entry points, time
5786 stamp, CRC32 checksums, etc.
5788 "mkimage" can be called in two ways: to verify existing images and
5789 print the header information, or to build new images.
5791 In the first form (with "-l" option) mkimage lists the information
5792 contained in the header of an existing U-Boot image; this includes
5793 checksum verification:
5795 tools/mkimage -l image
5796 -l ==> list image header information
5798 The second form (with "-d" option) is used to build a U-Boot image
5799 from a "data file" which is used as image payload:
5801 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5802 -n name -d data_file image
5803 -A ==> set architecture to 'arch'
5804 -O ==> set operating system to 'os'
5805 -T ==> set image type to 'type'
5806 -C ==> set compression type 'comp'
5807 -a ==> set load address to 'addr' (hex)
5808 -e ==> set entry point to 'ep' (hex)
5809 -n ==> set image name to 'name'
5810 -d ==> use image data from 'datafile'
5812 Right now, all Linux kernels for PowerPC systems use the same load
5813 address (0x00000000), but the entry point address depends on the
5816 - 2.2.x kernels have the entry point at 0x0000000C,
5817 - 2.3.x and later kernels have the entry point at 0x00000000.
5819 So a typical call to build a U-Boot image would read:
5821 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5822 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5823 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5824 > examples/uImage.TQM850L
5825 Image Name: 2.4.4 kernel for TQM850L
5826 Created: Wed Jul 19 02:34:59 2000
5827 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5828 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5829 Load Address: 0x00000000
5830 Entry Point: 0x00000000
5832 To verify the contents of the image (or check for corruption):
5834 -> tools/mkimage -l examples/uImage.TQM850L
5835 Image Name: 2.4.4 kernel for TQM850L
5836 Created: Wed Jul 19 02:34:59 2000
5837 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5838 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5839 Load Address: 0x00000000
5840 Entry Point: 0x00000000
5842 NOTE: for embedded systems where boot time is critical you can trade
5843 speed for memory and install an UNCOMPRESSED image instead: this
5844 needs more space in Flash, but boots much faster since it does not
5845 need to be uncompressed:
5847 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5848 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5849 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5850 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5851 > examples/uImage.TQM850L-uncompressed
5852 Image Name: 2.4.4 kernel for TQM850L
5853 Created: Wed Jul 19 02:34:59 2000
5854 Image Type: PowerPC Linux Kernel Image (uncompressed)
5855 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5856 Load Address: 0x00000000
5857 Entry Point: 0x00000000
5860 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5861 when your kernel is intended to use an initial ramdisk:
5863 -> tools/mkimage -n 'Simple Ramdisk Image' \
5864 > -A ppc -O linux -T ramdisk -C gzip \
5865 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5866 Image Name: Simple Ramdisk Image
5867 Created: Wed Jan 12 14:01:50 2000
5868 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5869 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5870 Load Address: 0x00000000
5871 Entry Point: 0x00000000
5873 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5874 option performs the converse operation of the mkimage's second form (the "-d"
5875 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5878 tools/dumpimage -i image -T type -p position data_file
5879 -i ==> extract from the 'image' a specific 'data_file'
5880 -T ==> set image type to 'type'
5881 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5884 Installing a Linux Image:
5885 -------------------------
5887 To downloading a U-Boot image over the serial (console) interface,
5888 you must convert the image to S-Record format:
5890 objcopy -I binary -O srec examples/image examples/image.srec
5892 The 'objcopy' does not understand the information in the U-Boot
5893 image header, so the resulting S-Record file will be relative to
5894 address 0x00000000. To load it to a given address, you need to
5895 specify the target address as 'offset' parameter with the 'loads'
5898 Example: install the image to address 0x40100000 (which on the
5899 TQM8xxL is in the first Flash bank):
5901 => erase 40100000 401FFFFF
5907 ## Ready for S-Record download ...
5908 ~>examples/image.srec
5909 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5911 15989 15990 15991 15992
5912 [file transfer complete]
5914 ## Start Addr = 0x00000000
5917 You can check the success of the download using the 'iminfo' command;
5918 this includes a checksum verification so you can be sure no data
5919 corruption happened:
5923 ## Checking Image at 40100000 ...
5924 Image Name: 2.2.13 for initrd on TQM850L
5925 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5926 Data Size: 335725 Bytes = 327 kB = 0 MB
5927 Load Address: 00000000
5928 Entry Point: 0000000c
5929 Verifying Checksum ... OK
5935 The "bootm" command is used to boot an application that is stored in
5936 memory (RAM or Flash). In case of a Linux kernel image, the contents
5937 of the "bootargs" environment variable is passed to the kernel as
5938 parameters. You can check and modify this variable using the
5939 "printenv" and "setenv" commands:
5942 => printenv bootargs
5943 bootargs=root=/dev/ram
5945 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5947 => printenv bootargs
5948 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5951 ## Booting Linux kernel at 40020000 ...
5952 Image Name: 2.2.13 for NFS on TQM850L
5953 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5954 Data Size: 381681 Bytes = 372 kB = 0 MB
5955 Load Address: 00000000
5956 Entry Point: 0000000c
5957 Verifying Checksum ... OK
5958 Uncompressing Kernel Image ... OK
5959 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
5960 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5961 time_init: decrementer frequency = 187500000/60
5962 Calibrating delay loop... 49.77 BogoMIPS
5963 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5966 If you want to boot a Linux kernel with initial RAM disk, you pass
5967 the memory addresses of both the kernel and the initrd image (PPBCOOT
5968 format!) to the "bootm" command:
5970 => imi 40100000 40200000
5972 ## Checking Image at 40100000 ...
5973 Image Name: 2.2.13 for initrd on TQM850L
5974 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5975 Data Size: 335725 Bytes = 327 kB = 0 MB
5976 Load Address: 00000000
5977 Entry Point: 0000000c
5978 Verifying Checksum ... OK
5980 ## Checking Image at 40200000 ...
5981 Image Name: Simple Ramdisk Image
5982 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5983 Data Size: 566530 Bytes = 553 kB = 0 MB
5984 Load Address: 00000000
5985 Entry Point: 00000000
5986 Verifying Checksum ... OK
5988 => bootm 40100000 40200000
5989 ## Booting Linux kernel at 40100000 ...
5990 Image Name: 2.2.13 for initrd on TQM850L
5991 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5992 Data Size: 335725 Bytes = 327 kB = 0 MB
5993 Load Address: 00000000
5994 Entry Point: 0000000c
5995 Verifying Checksum ... OK
5996 Uncompressing Kernel Image ... OK
5997 ## Loading RAMDisk Image at 40200000 ...
5998 Image Name: Simple Ramdisk Image
5999 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6000 Data Size: 566530 Bytes = 553 kB = 0 MB
6001 Load Address: 00000000
6002 Entry Point: 00000000
6003 Verifying Checksum ... OK
6004 Loading Ramdisk ... OK
6005 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
6006 Boot arguments: root=/dev/ram
6007 time_init: decrementer frequency = 187500000/60
6008 Calibrating delay loop... 49.77 BogoMIPS
6010 RAMDISK: Compressed image found at block 0
6011 VFS: Mounted root (ext2 filesystem).
6015 Boot Linux and pass a flat device tree:
6018 First, U-Boot must be compiled with the appropriate defines. See the section
6019 titled "Linux Kernel Interface" above for a more in depth explanation. The
6020 following is an example of how to start a kernel and pass an updated
6026 oft=oftrees/mpc8540ads.dtb
6027 => tftp $oftaddr $oft
6028 Speed: 1000, full duplex
6030 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6031 Filename 'oftrees/mpc8540ads.dtb'.
6032 Load address: 0x300000
6035 Bytes transferred = 4106 (100a hex)
6036 => tftp $loadaddr $bootfile
6037 Speed: 1000, full duplex
6039 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6041 Load address: 0x200000
6042 Loading:############
6044 Bytes transferred = 1029407 (fb51f hex)
6049 => bootm $loadaddr - $oftaddr
6050 ## Booting image at 00200000 ...
6051 Image Name: Linux-2.6.17-dirty
6052 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6053 Data Size: 1029343 Bytes = 1005.2 kB
6054 Load Address: 00000000
6055 Entry Point: 00000000
6056 Verifying Checksum ... OK
6057 Uncompressing Kernel Image ... OK
6058 Booting using flat device tree at 0x300000
6059 Using MPC85xx ADS machine description
6060 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6064 More About U-Boot Image Types:
6065 ------------------------------
6067 U-Boot supports the following image types:
6069 "Standalone Programs" are directly runnable in the environment
6070 provided by U-Boot; it is expected that (if they behave
6071 well) you can continue to work in U-Boot after return from
6072 the Standalone Program.
6073 "OS Kernel Images" are usually images of some Embedded OS which
6074 will take over control completely. Usually these programs
6075 will install their own set of exception handlers, device
6076 drivers, set up the MMU, etc. - this means, that you cannot
6077 expect to re-enter U-Boot except by resetting the CPU.
6078 "RAMDisk Images" are more or less just data blocks, and their
6079 parameters (address, size) are passed to an OS kernel that is
6081 "Multi-File Images" contain several images, typically an OS
6082 (Linux) kernel image and one or more data images like
6083 RAMDisks. This construct is useful for instance when you want
6084 to boot over the network using BOOTP etc., where the boot
6085 server provides just a single image file, but you want to get
6086 for instance an OS kernel and a RAMDisk image.
6088 "Multi-File Images" start with a list of image sizes, each
6089 image size (in bytes) specified by an "uint32_t" in network
6090 byte order. This list is terminated by an "(uint32_t)0".
6091 Immediately after the terminating 0 follow the images, one by
6092 one, all aligned on "uint32_t" boundaries (size rounded up to
6093 a multiple of 4 bytes).
6095 "Firmware Images" are binary images containing firmware (like
6096 U-Boot or FPGA images) which usually will be programmed to
6099 "Script files" are command sequences that will be executed by
6100 U-Boot's command interpreter; this feature is especially
6101 useful when you configure U-Boot to use a real shell (hush)
6102 as command interpreter.
6104 Booting the Linux zImage:
6105 -------------------------
6107 On some platforms, it's possible to boot Linux zImage. This is done
6108 using the "bootz" command. The syntax of "bootz" command is the same
6109 as the syntax of "bootm" command.
6111 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6112 kernel with raw initrd images. The syntax is slightly different, the
6113 address of the initrd must be augmented by it's size, in the following
6114 format: "<initrd addres>:<initrd size>".
6120 One of the features of U-Boot is that you can dynamically load and
6121 run "standalone" applications, which can use some resources of
6122 U-Boot like console I/O functions or interrupt services.
6124 Two simple examples are included with the sources:
6129 'examples/hello_world.c' contains a small "Hello World" Demo
6130 application; it is automatically compiled when you build U-Boot.
6131 It's configured to run at address 0x00040004, so you can play with it
6135 ## Ready for S-Record download ...
6136 ~>examples/hello_world.srec
6137 1 2 3 4 5 6 7 8 9 10 11 ...
6138 [file transfer complete]
6140 ## Start Addr = 0x00040004
6142 => go 40004 Hello World! This is a test.
6143 ## Starting application at 0x00040004 ...
6154 Hit any key to exit ...
6156 ## Application terminated, rc = 0x0
6158 Another example, which demonstrates how to register a CPM interrupt
6159 handler with the U-Boot code, can be found in 'examples/timer.c'.
6160 Here, a CPM timer is set up to generate an interrupt every second.
6161 The interrupt service routine is trivial, just printing a '.'
6162 character, but this is just a demo program. The application can be
6163 controlled by the following keys:
6165 ? - print current values og the CPM Timer registers
6166 b - enable interrupts and start timer
6167 e - stop timer and disable interrupts
6168 q - quit application
6171 ## Ready for S-Record download ...
6172 ~>examples/timer.srec
6173 1 2 3 4 5 6 7 8 9 10 11 ...
6174 [file transfer complete]
6176 ## Start Addr = 0x00040004
6179 ## Starting application at 0x00040004 ...
6182 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6185 [q, b, e, ?] Set interval 1000000 us
6188 [q, b, e, ?] ........
6189 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6192 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6195 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6198 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6200 [q, b, e, ?] ...Stopping timer
6202 [q, b, e, ?] ## Application terminated, rc = 0x0
6208 Over time, many people have reported problems when trying to use the
6209 "minicom" terminal emulation program for serial download. I (wd)
6210 consider minicom to be broken, and recommend not to use it. Under
6211 Unix, I recommend to use C-Kermit for general purpose use (and
6212 especially for kermit binary protocol download ("loadb" command), and
6213 use "cu" for S-Record download ("loads" command). See
6214 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6215 for help with kermit.
6218 Nevertheless, if you absolutely want to use it try adding this
6219 configuration to your "File transfer protocols" section:
6221 Name Program Name U/D FullScr IO-Red. Multi
6222 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6223 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6229 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6230 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6232 Building requires a cross environment; it is known to work on
6233 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6234 need gmake since the Makefiles are not compatible with BSD make).
6235 Note that the cross-powerpc package does not install include files;
6236 attempting to build U-Boot will fail because <machine/ansi.h> is
6237 missing. This file has to be installed and patched manually:
6239 # cd /usr/pkg/cross/powerpc-netbsd/include
6241 # ln -s powerpc machine
6242 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6243 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6245 Native builds *don't* work due to incompatibilities between native
6246 and U-Boot include files.
6248 Booting assumes that (the first part of) the image booted is a
6249 stage-2 loader which in turn loads and then invokes the kernel
6250 proper. Loader sources will eventually appear in the NetBSD source
6251 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6252 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6255 Implementation Internals:
6256 =========================
6258 The following is not intended to be a complete description of every
6259 implementation detail. However, it should help to understand the
6260 inner workings of U-Boot and make it easier to port it to custom
6264 Initial Stack, Global Data:
6265 ---------------------------
6267 The implementation of U-Boot is complicated by the fact that U-Boot
6268 starts running out of ROM (flash memory), usually without access to
6269 system RAM (because the memory controller is not initialized yet).
6270 This means that we don't have writable Data or BSS segments, and BSS
6271 is not initialized as zero. To be able to get a C environment working
6272 at all, we have to allocate at least a minimal stack. Implementation
6273 options for this are defined and restricted by the CPU used: Some CPU
6274 models provide on-chip memory (like the IMMR area on MPC8xx and
6275 MPC826x processors), on others (parts of) the data cache can be
6276 locked as (mis-) used as memory, etc.
6278 Chris Hallinan posted a good summary of these issues to the
6279 U-Boot mailing list:
6281 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6282 From: "Chris Hallinan" <clh@net1plus.com>
6283 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6286 Correct me if I'm wrong, folks, but the way I understand it
6287 is this: Using DCACHE as initial RAM for Stack, etc, does not
6288 require any physical RAM backing up the cache. The cleverness
6289 is that the cache is being used as a temporary supply of
6290 necessary storage before the SDRAM controller is setup. It's
6291 beyond the scope of this list to explain the details, but you
6292 can see how this works by studying the cache architecture and
6293 operation in the architecture and processor-specific manuals.
6295 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6296 is another option for the system designer to use as an
6297 initial stack/RAM area prior to SDRAM being available. Either
6298 option should work for you. Using CS 4 should be fine if your
6299 board designers haven't used it for something that would
6300 cause you grief during the initial boot! It is frequently not
6303 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6304 with your processor/board/system design. The default value
6305 you will find in any recent u-boot distribution in
6306 walnut.h should work for you. I'd set it to a value larger
6307 than your SDRAM module. If you have a 64MB SDRAM module, set
6308 it above 400_0000. Just make sure your board has no resources
6309 that are supposed to respond to that address! That code in
6310 start.S has been around a while and should work as is when
6311 you get the config right.
6316 It is essential to remember this, since it has some impact on the C
6317 code for the initialization procedures:
6319 * Initialized global data (data segment) is read-only. Do not attempt
6322 * Do not use any uninitialized global data (or implicitly initialized
6323 as zero data - BSS segment) at all - this is undefined, initiali-
6324 zation is performed later (when relocating to RAM).
6326 * Stack space is very limited. Avoid big data buffers or things like
6329 Having only the stack as writable memory limits means we cannot use
6330 normal global data to share information between the code. But it
6331 turned out that the implementation of U-Boot can be greatly
6332 simplified by making a global data structure (gd_t) available to all
6333 functions. We could pass a pointer to this data as argument to _all_
6334 functions, but this would bloat the code. Instead we use a feature of
6335 the GCC compiler (Global Register Variables) to share the data: we
6336 place a pointer (gd) to the global data into a register which we
6337 reserve for this purpose.
6339 When choosing a register for such a purpose we are restricted by the
6340 relevant (E)ABI specifications for the current architecture, and by
6341 GCC's implementation.
6343 For PowerPC, the following registers have specific use:
6345 R2: reserved for system use
6346 R3-R4: parameter passing and return values
6347 R5-R10: parameter passing
6348 R13: small data area pointer
6352 (U-Boot also uses R12 as internal GOT pointer. r12
6353 is a volatile register so r12 needs to be reset when
6354 going back and forth between asm and C)
6356 ==> U-Boot will use R2 to hold a pointer to the global data
6358 Note: on PPC, we could use a static initializer (since the
6359 address of the global data structure is known at compile time),
6360 but it turned out that reserving a register results in somewhat
6361 smaller code - although the code savings are not that big (on
6362 average for all boards 752 bytes for the whole U-Boot image,
6363 624 text + 127 data).
6365 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6366 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6368 ==> U-Boot will use P3 to hold a pointer to the global data
6370 On ARM, the following registers are used:
6372 R0: function argument word/integer result
6373 R1-R3: function argument word
6374 R9: platform specific
6375 R10: stack limit (used only if stack checking is enabled)
6376 R11: argument (frame) pointer
6377 R12: temporary workspace
6380 R15: program counter
6382 ==> U-Boot will use R9 to hold a pointer to the global data
6384 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6386 On Nios II, the ABI is documented here:
6387 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6389 ==> U-Boot will use gp to hold a pointer to the global data
6391 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6392 to access small data sections, so gp is free.
6394 On NDS32, the following registers are used:
6396 R0-R1: argument/return
6398 R15: temporary register for assembler
6399 R16: trampoline register
6400 R28: frame pointer (FP)
6401 R29: global pointer (GP)
6402 R30: link register (LP)
6403 R31: stack pointer (SP)
6404 PC: program counter (PC)
6406 ==> U-Boot will use R10 to hold a pointer to the global data
6408 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6409 or current versions of GCC may "optimize" the code too much.
6414 U-Boot runs in system state and uses physical addresses, i.e. the
6415 MMU is not used either for address mapping nor for memory protection.
6417 The available memory is mapped to fixed addresses using the memory
6418 controller. In this process, a contiguous block is formed for each
6419 memory type (Flash, SDRAM, SRAM), even when it consists of several
6420 physical memory banks.
6422 U-Boot is installed in the first 128 kB of the first Flash bank (on
6423 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6424 booting and sizing and initializing DRAM, the code relocates itself
6425 to the upper end of DRAM. Immediately below the U-Boot code some
6426 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6427 configuration setting]. Below that, a structure with global Board
6428 Info data is placed, followed by the stack (growing downward).
6430 Additionally, some exception handler code is copied to the low 8 kB
6431 of DRAM (0x00000000 ... 0x00001FFF).
6433 So a typical memory configuration with 16 MB of DRAM could look like
6436 0x0000 0000 Exception Vector code
6439 0x0000 2000 Free for Application Use
6445 0x00FB FF20 Monitor Stack (Growing downward)
6446 0x00FB FFAC Board Info Data and permanent copy of global data
6447 0x00FC 0000 Malloc Arena
6450 0x00FE 0000 RAM Copy of Monitor Code
6451 ... eventually: LCD or video framebuffer
6452 ... eventually: pRAM (Protected RAM - unchanged by reset)
6453 0x00FF FFFF [End of RAM]
6456 System Initialization:
6457 ----------------------
6459 In the reset configuration, U-Boot starts at the reset entry point
6460 (on most PowerPC systems at address 0x00000100). Because of the reset
6461 configuration for CS0# this is a mirror of the on board Flash memory.
6462 To be able to re-map memory U-Boot then jumps to its link address.
6463 To be able to implement the initialization code in C, a (small!)
6464 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6465 which provide such a feature like MPC8xx or MPC8260), or in a locked
6466 part of the data cache. After that, U-Boot initializes the CPU core,
6467 the caches and the SIU.
6469 Next, all (potentially) available memory banks are mapped using a
6470 preliminary mapping. For example, we put them on 512 MB boundaries
6471 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6472 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6473 programmed for SDRAM access. Using the temporary configuration, a
6474 simple memory test is run that determines the size of the SDRAM
6477 When there is more than one SDRAM bank, and the banks are of
6478 different size, the largest is mapped first. For equal size, the first
6479 bank (CS2#) is mapped first. The first mapping is always for address
6480 0x00000000, with any additional banks following immediately to create
6481 contiguous memory starting from 0.
6483 Then, the monitor installs itself at the upper end of the SDRAM area
6484 and allocates memory for use by malloc() and for the global Board
6485 Info data; also, the exception vector code is copied to the low RAM
6486 pages, and the final stack is set up.
6488 Only after this relocation will you have a "normal" C environment;
6489 until that you are restricted in several ways, mostly because you are
6490 running from ROM, and because the code will have to be relocated to a
6494 U-Boot Porting Guide:
6495 ----------------------
6497 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6501 int main(int argc, char *argv[])
6503 sighandler_t no_more_time;
6505 signal(SIGALRM, no_more_time);
6506 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6508 if (available_money > available_manpower) {
6509 Pay consultant to port U-Boot;
6513 Download latest U-Boot source;
6515 Subscribe to u-boot mailing list;
6518 email("Hi, I am new to U-Boot, how do I get started?");
6521 Read the README file in the top level directory;
6522 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6523 Read applicable doc/*.README;
6524 Read the source, Luke;
6525 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6528 if (available_money > toLocalCurrency ($2500))
6531 Add a lot of aggravation and time;
6533 if (a similar board exists) { /* hopefully... */
6534 cp -a board/<similar> board/<myboard>
6535 cp include/configs/<similar>.h include/configs/<myboard>.h
6537 Create your own board support subdirectory;
6538 Create your own board include/configs/<myboard>.h file;
6540 Edit new board/<myboard> files
6541 Edit new include/configs/<myboard>.h
6546 Add / modify source code;
6550 email("Hi, I am having problems...");
6552 Send patch file to the U-Boot email list;
6553 if (reasonable critiques)
6554 Incorporate improvements from email list code review;
6556 Defend code as written;
6562 void no_more_time (int sig)
6571 All contributions to U-Boot should conform to the Linux kernel
6572 coding style; see the file "Documentation/CodingStyle" and the script
6573 "scripts/Lindent" in your Linux kernel source directory.
6575 Source files originating from a different project (for example the
6576 MTD subsystem) are generally exempt from these guidelines and are not
6577 reformatted to ease subsequent migration to newer versions of those
6580 Please note that U-Boot is implemented in C (and to some small parts in
6581 Assembler); no C++ is used, so please do not use C++ style comments (//)
6584 Please also stick to the following formatting rules:
6585 - remove any trailing white space
6586 - use TAB characters for indentation and vertical alignment, not spaces
6587 - make sure NOT to use DOS '\r\n' line feeds
6588 - do not add more than 2 consecutive empty lines to source files
6589 - do not add trailing empty lines to source files
6591 Submissions which do not conform to the standards may be returned
6592 with a request to reformat the changes.
6598 Since the number of patches for U-Boot is growing, we need to
6599 establish some rules. Submissions which do not conform to these rules
6600 may be rejected, even when they contain important and valuable stuff.
6602 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6604 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6605 see http://lists.denx.de/mailman/listinfo/u-boot
6607 When you send a patch, please include the following information with
6610 * For bug fixes: a description of the bug and how your patch fixes
6611 this bug. Please try to include a way of demonstrating that the
6612 patch actually fixes something.
6614 * For new features: a description of the feature and your
6617 * A CHANGELOG entry as plaintext (separate from the patch)
6619 * For major contributions, your entry to the CREDITS file
6621 * When you add support for a new board, don't forget to add a
6622 maintainer e-mail address to the boards.cfg file, too.
6624 * If your patch adds new configuration options, don't forget to
6625 document these in the README file.
6627 * The patch itself. If you are using git (which is *strongly*
6628 recommended) you can easily generate the patch using the
6629 "git format-patch". If you then use "git send-email" to send it to
6630 the U-Boot mailing list, you will avoid most of the common problems
6631 with some other mail clients.
6633 If you cannot use git, use "diff -purN OLD NEW". If your version of
6634 diff does not support these options, then get the latest version of
6637 The current directory when running this command shall be the parent
6638 directory of the U-Boot source tree (i. e. please make sure that
6639 your patch includes sufficient directory information for the
6642 We prefer patches as plain text. MIME attachments are discouraged,
6643 and compressed attachments must not be used.
6645 * If one logical set of modifications affects or creates several
6646 files, all these changes shall be submitted in a SINGLE patch file.
6648 * Changesets that contain different, unrelated modifications shall be
6649 submitted as SEPARATE patches, one patch per changeset.
6654 * Before sending the patch, run the MAKEALL script on your patched
6655 source tree and make sure that no errors or warnings are reported
6656 for any of the boards.
6658 * Keep your modifications to the necessary minimum: A patch
6659 containing several unrelated changes or arbitrary reformats will be
6660 returned with a request to re-formatting / split it.
6662 * If you modify existing code, make sure that your new code does not
6663 add to the memory footprint of the code ;-) Small is beautiful!
6664 When adding new features, these should compile conditionally only
6665 (using #ifdef), and the resulting code with the new feature
6666 disabled must not need more memory than the old code without your
6669 * Remember that there is a size limit of 100 kB per message on the
6670 u-boot mailing list. Bigger patches will be moderated. If they are
6671 reasonable and not too big, they will be acknowledged. But patches
6672 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob