2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_761320
685 CONFIG_ARM_ERRATA_773022
686 CONFIG_ARM_ERRATA_774769
687 CONFIG_ARM_ERRATA_794072
689 If set, the workarounds for these ARM errata are applied early
690 during U-Boot startup. Note that these options force the
691 workarounds to be applied; no CPU-type/version detection
692 exists, unlike the similar options in the Linux kernel. Do not
693 set these options unless they apply!
696 Generic timer clock source frequency.
698 COUNTER_FREQUENCY_REAL
699 Generic timer clock source frequency if the real clock is
700 different from COUNTER_FREQUENCY, and can only be determined
703 NOTE: The following can be machine specific errata. These
704 do have ability to provide rudimentary version and machine
705 specific checks, but expect no product checks.
706 CONFIG_ARM_ERRATA_430973
707 CONFIG_ARM_ERRATA_454179
708 CONFIG_ARM_ERRATA_621766
709 CONFIG_ARM_ERRATA_798870
710 CONFIG_ARM_ERRATA_801819
713 CONFIG_TEGRA_SUPPORT_NON_SECURE
715 Support executing U-Boot in non-secure (NS) mode. Certain
716 impossible actions will be skipped if the CPU is in NS mode,
717 such as ARM architectural timer initialization.
719 - Linux Kernel Interface:
722 U-Boot stores all clock information in Hz
723 internally. For binary compatibility with older Linux
724 kernels (which expect the clocks passed in the
725 bd_info data to be in MHz) the environment variable
726 "clocks_in_mhz" can be defined so that U-Boot
727 converts clock data to MHZ before passing it to the
729 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
730 "clocks_in_mhz=1" is automatically included in the
733 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
735 When transferring memsize parameter to Linux, some versions
736 expect it to be in bytes, others in MB.
737 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
741 New kernel versions are expecting firmware settings to be
742 passed using flattened device trees (based on open firmware
746 * New libfdt-based support
747 * Adds the "fdt" command
748 * The bootm command automatically updates the fdt
750 OF_CPU - The proper name of the cpus node (only required for
751 MPC512X and MPC5xxx based boards).
752 OF_SOC - The proper name of the soc node (only required for
753 MPC512X and MPC5xxx based boards).
754 OF_TBCLK - The timebase frequency.
755 OF_STDOUT_PATH - The path to the console device
757 boards with QUICC Engines require OF_QE to set UCC MAC
760 CONFIG_OF_BOARD_SETUP
762 Board code has addition modification that it wants to make
763 to the flat device tree before handing it off to the kernel
765 CONFIG_OF_SYSTEM_SETUP
767 Other code has addition modification that it wants to make
768 to the flat device tree before handing it off to the kernel.
769 This causes ft_system_setup() to be called before booting
774 This define fills in the correct boot CPU in the boot
775 param header, the default value is zero if undefined.
779 U-Boot can detect if an IDE device is present or not.
780 If not, and this new config option is activated, U-Boot
781 removes the ATA node from the DTS before booting Linux,
782 so the Linux IDE driver does not probe the device and
783 crash. This is needed for buggy hardware (uc101) where
784 no pull down resistor is connected to the signal IDE5V_DD7.
786 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
788 This setting is mandatory for all boards that have only one
789 machine type and must be used to specify the machine type
790 number as it appears in the ARM machine registry
791 (see http://www.arm.linux.org.uk/developer/machines/).
792 Only boards that have multiple machine types supported
793 in a single configuration file and the machine type is
794 runtime discoverable, do not have to use this setting.
796 - vxWorks boot parameters:
798 bootvx constructs a valid bootline using the following
799 environments variables: bootdev, bootfile, ipaddr, netmask,
800 serverip, gatewayip, hostname, othbootargs.
801 It loads the vxWorks image pointed bootfile.
803 Note: If a "bootargs" environment is defined, it will overwride
804 the defaults discussed just above.
806 - Cache Configuration:
807 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
808 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
809 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
811 - Cache Configuration for ARM:
812 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
814 CONFIG_SYS_PL310_BASE - Physical base address of PL310
815 controller register space
820 Define this if you want support for Amba PrimeCell PL010 UARTs.
824 Define this if you want support for Amba PrimeCell PL011 UARTs.
828 If you have Amba PrimeCell PL011 UARTs, set this variable to
829 the clock speed of the UARTs.
833 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
834 define this to a list of base addresses for each (supported)
835 port. See e.g. include/configs/versatile.h
837 CONFIG_SERIAL_HW_FLOW_CONTROL
839 Define this variable to enable hw flow control in serial driver.
840 Current user of this option is drivers/serial/nsl16550.c driver
843 Depending on board, define exactly one serial port
844 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
845 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
846 console by defining CONFIG_8xx_CONS_NONE
848 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
849 port routines must be defined elsewhere
850 (i.e. serial_init(), serial_getc(), ...)
853 Enables console device for a color framebuffer. Needs following
854 defines (cf. smiLynxEM, i8042)
855 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
857 VIDEO_HW_RECTFILL graphic chip supports
860 VIDEO_HW_BITBLT graphic chip supports
861 bit-blit (cf. smiLynxEM)
862 VIDEO_VISIBLE_COLS visible pixel columns
864 VIDEO_VISIBLE_ROWS visible pixel rows
865 VIDEO_PIXEL_SIZE bytes per pixel
866 VIDEO_DATA_FORMAT graphic data format
867 (0-5, cf. cfb_console.c)
868 VIDEO_FB_ADRS framebuffer address
869 VIDEO_KBD_INIT_FCT keyboard int fct
870 (i.e. i8042_kbd_init())
871 VIDEO_TSTC_FCT test char fct
873 VIDEO_GETC_FCT get char fct
875 CONFIG_CONSOLE_CURSOR cursor drawing on/off
876 (requires blink timer
878 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
879 CONFIG_CONSOLE_TIME display time/date info in
881 (requires CONFIG_CMD_DATE)
882 CONFIG_VIDEO_LOGO display Linux logo in
884 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
885 linux_logo.h for logo.
886 Requires CONFIG_VIDEO_LOGO
887 CONFIG_CONSOLE_EXTRA_INFO
888 additional board info beside
891 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
892 a limited number of ANSI escape sequences (cursor control,
893 erase functions and limited graphics rendition control).
895 When CONFIG_CFB_CONSOLE is defined, video console is
896 default i/o. Serial console can be forced with
897 environment 'console=serial'.
899 When CONFIG_SILENT_CONSOLE is defined, all console
900 messages (by U-Boot and Linux!) can be silenced with
901 the "silent" environment variable. See
902 doc/README.silent for more information.
904 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
906 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
910 CONFIG_BAUDRATE - in bps
911 Select one of the baudrates listed in
912 CONFIG_SYS_BAUDRATE_TABLE, see below.
913 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
915 - Console Rx buffer length
916 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
917 the maximum receive buffer length for the SMC.
918 This option is actual only for 82xx and 8xx possible.
919 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
920 must be defined, to setup the maximum idle timeout for
923 - Pre-Console Buffer:
924 Prior to the console being initialised (i.e. serial UART
925 initialised etc) all console output is silently discarded.
926 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
927 buffer any console messages prior to the console being
928 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
929 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
930 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
931 bytes are output before the console is initialised, the
932 earlier bytes are discarded.
934 Note that when printing the buffer a copy is made on the
935 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
937 'Sane' compilers will generate smaller code if
938 CONFIG_PRE_CON_BUF_SZ is a power of 2
940 - Safe printf() functions
941 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
942 the printf() functions. These are defined in
943 include/vsprintf.h and include snprintf(), vsnprintf() and
944 so on. Code size increase is approximately 300-500 bytes.
945 If this option is not given then these functions will
946 silently discard their buffer size argument - this means
947 you are not getting any overflow checking in this case.
949 - Boot Delay: CONFIG_BOOTDELAY - in seconds
950 Delay before automatically booting the default image;
951 set to -1 to disable autoboot.
952 set to -2 to autoboot with no delay and not check for abort
953 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
955 See doc/README.autoboot for these options that
956 work with CONFIG_BOOTDELAY. None are required.
957 CONFIG_BOOT_RETRY_TIME
958 CONFIG_BOOT_RETRY_MIN
959 CONFIG_AUTOBOOT_KEYED
960 CONFIG_AUTOBOOT_PROMPT
961 CONFIG_AUTOBOOT_DELAY_STR
962 CONFIG_AUTOBOOT_STOP_STR
963 CONFIG_ZERO_BOOTDELAY_CHECK
964 CONFIG_RESET_TO_RETRY
968 Only needed when CONFIG_BOOTDELAY is enabled;
969 define a command string that is automatically executed
970 when no character is read on the console interface
971 within "Boot Delay" after reset.
974 This can be used to pass arguments to the bootm
975 command. The value of CONFIG_BOOTARGS goes into the
976 environment value "bootargs".
978 CONFIG_RAMBOOT and CONFIG_NFSBOOT
979 The value of these goes into the environment as
980 "ramboot" and "nfsboot" respectively, and can be used
981 as a convenience, when switching between booting from
985 CONFIG_BOOTCOUNT_LIMIT
986 Implements a mechanism for detecting a repeating reboot
988 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
991 If no softreset save registers are found on the hardware
992 "bootcount" is stored in the environment. To prevent a
993 saveenv on all reboots, the environment variable
994 "upgrade_available" is used. If "upgrade_available" is
995 0, "bootcount" is always 0, if "upgrade_available" is
996 1 "bootcount" is incremented in the environment.
997 So the Userspace Applikation must set the "upgrade_available"
998 and "bootcount" variable to 0, if a boot was successfully.
1000 - Pre-Boot Commands:
1003 When this option is #defined, the existence of the
1004 environment variable "preboot" will be checked
1005 immediately before starting the CONFIG_BOOTDELAY
1006 countdown and/or running the auto-boot command resp.
1007 entering interactive mode.
1009 This feature is especially useful when "preboot" is
1010 automatically generated or modified. For an example
1011 see the LWMON board specific code: here "preboot" is
1012 modified when the user holds down a certain
1013 combination of keys on the (special) keyboard when
1016 - Serial Download Echo Mode:
1018 If defined to 1, all characters received during a
1019 serial download (using the "loads" command) are
1020 echoed back. This might be needed by some terminal
1021 emulations (like "cu"), but may as well just take
1022 time on others. This setting #define's the initial
1023 value of the "loads_echo" environment variable.
1025 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1026 CONFIG_KGDB_BAUDRATE
1027 Select one of the baudrates listed in
1028 CONFIG_SYS_BAUDRATE_TABLE, see below.
1030 - Monitor Functions:
1031 Monitor commands can be included or excluded
1032 from the build by using the #include files
1033 <config_cmd_all.h> and #undef'ing unwanted
1034 commands, or adding #define's for wanted commands.
1036 The default command configuration includes all commands
1037 except those marked below with a "*".
1039 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1040 CONFIG_CMD_ASKENV * ask for env variable
1041 CONFIG_CMD_BDI bdinfo
1042 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1043 CONFIG_CMD_BMP * BMP support
1044 CONFIG_CMD_BSP * Board specific commands
1045 CONFIG_CMD_BOOTD bootd
1046 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1047 CONFIG_CMD_CACHE * icache, dcache
1048 CONFIG_CMD_CLK * clock command support
1049 CONFIG_CMD_CONSOLE coninfo
1050 CONFIG_CMD_CRC32 * crc32
1051 CONFIG_CMD_DATE * support for RTC, date/time...
1052 CONFIG_CMD_DHCP * DHCP support
1053 CONFIG_CMD_DIAG * Diagnostics
1054 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1055 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1056 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1057 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1058 CONFIG_CMD_DTT * Digital Therm and Thermostat
1059 CONFIG_CMD_ECHO echo arguments
1060 CONFIG_CMD_EDITENV edit env variable
1061 CONFIG_CMD_EEPROM * EEPROM read/write support
1062 CONFIG_CMD_ELF * bootelf, bootvx
1063 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1064 CONFIG_CMD_ENV_FLAGS * display details about env flags
1065 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1066 CONFIG_CMD_EXPORTENV * export the environment
1067 CONFIG_CMD_EXT2 * ext2 command support
1068 CONFIG_CMD_EXT4 * ext4 command support
1069 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1070 that work for multiple fs types
1071 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1072 CONFIG_CMD_SAVEENV saveenv
1073 CONFIG_CMD_FDC * Floppy Disk Support
1074 CONFIG_CMD_FAT * FAT command support
1075 CONFIG_CMD_FLASH flinfo, erase, protect
1076 CONFIG_CMD_FPGA FPGA device initialization support
1077 CONFIG_CMD_FUSE * Device fuse support
1078 CONFIG_CMD_GETTIME * Get time since boot
1079 CONFIG_CMD_GO * the 'go' command (exec code)
1080 CONFIG_CMD_GREPENV * search environment
1081 CONFIG_CMD_HASH * calculate hash / digest
1082 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1083 CONFIG_CMD_I2C * I2C serial bus support
1084 CONFIG_CMD_IDE * IDE harddisk support
1085 CONFIG_CMD_IMI iminfo
1086 CONFIG_CMD_IMLS List all images found in NOR flash
1087 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1088 CONFIG_CMD_IMMAP * IMMR dump support
1089 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1090 CONFIG_CMD_IMPORTENV * import an environment
1091 CONFIG_CMD_INI * import data from an ini file into the env
1092 CONFIG_CMD_IRQ * irqinfo
1093 CONFIG_CMD_ITEST Integer/string test of 2 values
1094 CONFIG_CMD_JFFS2 * JFFS2 Support
1095 CONFIG_CMD_KGDB * kgdb
1096 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1097 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1099 CONFIG_CMD_LOADB loadb
1100 CONFIG_CMD_LOADS loads
1101 CONFIG_CMD_MD5SUM * print md5 message digest
1102 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1103 CONFIG_CMD_MEMINFO * Display detailed memory information
1104 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1106 CONFIG_CMD_MEMTEST * mtest
1107 CONFIG_CMD_MISC Misc functions like sleep etc
1108 CONFIG_CMD_MMC * MMC memory mapped support
1109 CONFIG_CMD_MII * MII utility commands
1110 CONFIG_CMD_MTDPARTS * MTD partition support
1111 CONFIG_CMD_NAND * NAND support
1112 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1113 CONFIG_CMD_NFS NFS support
1114 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1115 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1116 CONFIG_CMD_PCI * pciinfo
1117 CONFIG_CMD_PCMCIA * PCMCIA support
1118 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1120 CONFIG_CMD_PORTIO * Port I/O
1121 CONFIG_CMD_READ * Read raw data from partition
1122 CONFIG_CMD_REGINFO * Register dump
1123 CONFIG_CMD_RUN run command in env variable
1124 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1125 CONFIG_CMD_SAVES * save S record dump
1126 CONFIG_CMD_SCSI * SCSI Support
1127 CONFIG_CMD_SDRAM * print SDRAM configuration information
1128 (requires CONFIG_CMD_I2C)
1129 CONFIG_CMD_SETGETDCR Support for DCR Register access
1131 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1132 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1133 (requires CONFIG_CMD_MEMORY)
1134 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1135 CONFIG_CMD_SOURCE "source" command Support
1136 CONFIG_CMD_SPI * SPI serial bus support
1137 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1138 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1139 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1140 CONFIG_CMD_TIMER * access to the system tick timer
1141 CONFIG_CMD_USB * USB support
1142 CONFIG_CMD_CDP * Cisco Discover Protocol support
1143 CONFIG_CMD_MFSL * Microblaze FSL support
1144 CONFIG_CMD_XIMG Load part of Multi Image
1145 CONFIG_CMD_UUID * Generate random UUID or GUID string
1147 EXAMPLE: If you want all functions except of network
1148 support you can write:
1150 #include "config_cmd_all.h"
1151 #undef CONFIG_CMD_NET
1154 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1156 Note: Don't enable the "icache" and "dcache" commands
1157 (configuration option CONFIG_CMD_CACHE) unless you know
1158 what you (and your U-Boot users) are doing. Data
1159 cache cannot be enabled on systems like the 8xx or
1160 8260 (where accesses to the IMMR region must be
1161 uncached), and it cannot be disabled on all other
1162 systems where we (mis-) use the data cache to hold an
1163 initial stack and some data.
1166 XXX - this list needs to get updated!
1168 - Regular expression support:
1170 If this variable is defined, U-Boot is linked against
1171 the SLRE (Super Light Regular Expression) library,
1172 which adds regex support to some commands, as for
1173 example "env grep" and "setexpr".
1177 If this variable is defined, U-Boot will use a device tree
1178 to configure its devices, instead of relying on statically
1179 compiled #defines in the board file. This option is
1180 experimental and only available on a few boards. The device
1181 tree is available in the global data as gd->fdt_blob.
1183 U-Boot needs to get its device tree from somewhere. This can
1184 be done using one of the two options below:
1187 If this variable is defined, U-Boot will embed a device tree
1188 binary in its image. This device tree file should be in the
1189 board directory and called <soc>-<board>.dts. The binary file
1190 is then picked up in board_init_f() and made available through
1191 the global data structure as gd->blob.
1194 If this variable is defined, U-Boot will build a device tree
1195 binary. It will be called u-boot.dtb. Architecture-specific
1196 code will locate it at run-time. Generally this works by:
1198 cat u-boot.bin u-boot.dtb >image.bin
1200 and in fact, U-Boot does this for you, creating a file called
1201 u-boot-dtb.bin which is useful in the common case. You can
1202 still use the individual files if you need something more
1207 If this variable is defined, it enables watchdog
1208 support for the SoC. There must be support in the SoC
1209 specific code for a watchdog. For the 8xx and 8260
1210 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1211 register. When supported for a specific SoC is
1212 available, then no further board specific code should
1213 be needed to use it.
1216 When using a watchdog circuitry external to the used
1217 SoC, then define this variable and provide board
1218 specific code for the "hw_watchdog_reset" function.
1220 CONFIG_AT91_HW_WDT_TIMEOUT
1221 specify the timeout in seconds. default 2 seconds.
1224 CONFIG_VERSION_VARIABLE
1225 If this variable is defined, an environment variable
1226 named "ver" is created by U-Boot showing the U-Boot
1227 version as printed by the "version" command.
1228 Any change to this variable will be reverted at the
1233 When CONFIG_CMD_DATE is selected, the type of the RTC
1234 has to be selected, too. Define exactly one of the
1237 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1238 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1239 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1240 CONFIG_RTC_MC146818 - use MC146818 RTC
1241 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1242 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1243 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1244 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1245 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1246 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1247 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1248 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1249 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1252 Note that if the RTC uses I2C, then the I2C interface
1253 must also be configured. See I2C Support, below.
1256 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1258 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1259 chip-ngpio pairs that tell the PCA953X driver the number of
1260 pins supported by a particular chip.
1262 Note that if the GPIO device uses I2C, then the I2C interface
1263 must also be configured. See I2C Support, below.
1266 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1267 accesses and can checksum them or write a list of them out
1268 to memory. See the 'iotrace' command for details. This is
1269 useful for testing device drivers since it can confirm that
1270 the driver behaves the same way before and after a code
1271 change. Currently this is supported on sandbox and arm. To
1272 add support for your architecture, add '#include <iotrace.h>'
1273 to the bottom of arch/<arch>/include/asm/io.h and test.
1275 Example output from the 'iotrace stats' command is below.
1276 Note that if the trace buffer is exhausted, the checksum will
1277 still continue to operate.
1280 Start: 10000000 (buffer start address)
1281 Size: 00010000 (buffer size)
1282 Offset: 00000120 (current buffer offset)
1283 Output: 10000120 (start + offset)
1284 Count: 00000018 (number of trace records)
1285 CRC32: 9526fb66 (CRC32 of all trace records)
1287 - Timestamp Support:
1289 When CONFIG_TIMESTAMP is selected, the timestamp
1290 (date and time) of an image is printed by image
1291 commands like bootm or iminfo. This option is
1292 automatically enabled when you select CONFIG_CMD_DATE .
1294 - Partition Labels (disklabels) Supported:
1295 Zero or more of the following:
1296 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1297 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1298 Intel architecture, USB sticks, etc.
1299 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1300 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1301 bootloader. Note 2TB partition limit; see
1303 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1305 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1306 CONFIG_CMD_SCSI) you must configure support for at
1307 least one non-MTD partition type as well.
1310 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1311 board configurations files but used nowhere!
1313 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1314 be performed by calling the function
1315 ide_set_reset(int reset)
1316 which has to be defined in a board specific file
1321 Set this to enable ATAPI support.
1326 Set this to enable support for disks larger than 137GB
1327 Also look at CONFIG_SYS_64BIT_LBA.
1328 Whithout these , LBA48 support uses 32bit variables and will 'only'
1329 support disks up to 2.1TB.
1331 CONFIG_SYS_64BIT_LBA:
1332 When enabled, makes the IDE subsystem use 64bit sector addresses.
1336 At the moment only there is only support for the
1337 SYM53C8XX SCSI controller; define
1338 CONFIG_SCSI_SYM53C8XX to enable it.
1340 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1341 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1342 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1343 maximum numbers of LUNs, SCSI ID's and target
1345 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1347 The environment variable 'scsidevs' is set to the number of
1348 SCSI devices found during the last scan.
1350 - NETWORK Support (PCI):
1352 Support for Intel 8254x/8257x gigabit chips.
1355 Utility code for direct access to the SPI bus on Intel 8257x.
1356 This does not do anything useful unless you set at least one
1357 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1359 CONFIG_E1000_SPI_GENERIC
1360 Allow generic access to the SPI bus on the Intel 8257x, for
1361 example with the "sspi" command.
1364 Management command for E1000 devices. When used on devices
1365 with SPI support you can reprogram the EEPROM from U-Boot.
1368 Support for Intel 82557/82559/82559ER chips.
1369 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1370 write routine for first time initialisation.
1373 Support for Digital 2114x chips.
1374 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1375 modem chip initialisation (KS8761/QS6611).
1378 Support for National dp83815 chips.
1381 Support for National dp8382[01] gigabit chips.
1383 - NETWORK Support (other):
1385 CONFIG_DRIVER_AT91EMAC
1386 Support for AT91RM9200 EMAC.
1389 Define this to use reduced MII inteface
1391 CONFIG_DRIVER_AT91EMAC_QUIET
1392 If this defined, the driver is quiet.
1393 The driver doen't show link status messages.
1395 CONFIG_CALXEDA_XGMAC
1396 Support for the Calxeda XGMAC device
1399 Support for SMSC's LAN91C96 chips.
1401 CONFIG_LAN91C96_BASE
1402 Define this to hold the physical address
1403 of the LAN91C96's I/O space
1405 CONFIG_LAN91C96_USE_32_BIT
1406 Define this to enable 32 bit addressing
1409 Support for SMSC's LAN91C111 chip
1411 CONFIG_SMC91111_BASE
1412 Define this to hold the physical address
1413 of the device (I/O space)
1415 CONFIG_SMC_USE_32_BIT
1416 Define this if data bus is 32 bits
1418 CONFIG_SMC_USE_IOFUNCS
1419 Define this to use i/o functions instead of macros
1420 (some hardware wont work with macros)
1422 CONFIG_DRIVER_TI_EMAC
1423 Support for davinci emac
1425 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1426 Define this if you have more then 3 PHYs.
1429 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1431 CONFIG_FTGMAC100_EGIGA
1432 Define this to use GE link update with gigabit PHY.
1433 Define this if FTGMAC100 is connected to gigabit PHY.
1434 If your system has 10/100 PHY only, it might not occur
1435 wrong behavior. Because PHY usually return timeout or
1436 useless data when polling gigabit status and gigabit
1437 control registers. This behavior won't affect the
1438 correctnessof 10/100 link speed update.
1441 Support for SMSC's LAN911x and LAN921x chips
1444 Define this to hold the physical address
1445 of the device (I/O space)
1447 CONFIG_SMC911X_32_BIT
1448 Define this if data bus is 32 bits
1450 CONFIG_SMC911X_16_BIT
1451 Define this if data bus is 16 bits. If your processor
1452 automatically converts one 32 bit word to two 16 bit
1453 words you may also try CONFIG_SMC911X_32_BIT.
1456 Support for Renesas on-chip Ethernet controller
1458 CONFIG_SH_ETHER_USE_PORT
1459 Define the number of ports to be used
1461 CONFIG_SH_ETHER_PHY_ADDR
1462 Define the ETH PHY's address
1464 CONFIG_SH_ETHER_CACHE_WRITEBACK
1465 If this option is set, the driver enables cache flush.
1469 Support for PWM modul on the imx6.
1473 Support TPM devices.
1475 CONFIG_TPM_TIS_INFINEON
1476 Support for Infineon i2c bus TPM devices. Only one device
1477 per system is supported at this time.
1479 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1480 Define the burst count bytes upper limit
1482 CONFIG_TPM_ATMEL_TWI
1483 Support for Atmel TWI TPM device. Requires I2C support.
1486 Support for generic parallel port TPM devices. Only one device
1487 per system is supported at this time.
1489 CONFIG_TPM_TIS_BASE_ADDRESS
1490 Base address where the generic TPM device is mapped
1491 to. Contemporary x86 systems usually map it at
1495 Add tpm monitor functions.
1496 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1497 provides monitor access to authorized functions.
1500 Define this to enable the TPM support library which provides
1501 functional interfaces to some TPM commands.
1502 Requires support for a TPM device.
1504 CONFIG_TPM_AUTH_SESSIONS
1505 Define this to enable authorized functions in the TPM library.
1506 Requires CONFIG_TPM and CONFIG_SHA1.
1509 At the moment only the UHCI host controller is
1510 supported (PIP405, MIP405, MPC5200); define
1511 CONFIG_USB_UHCI to enable it.
1512 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1513 and define CONFIG_USB_STORAGE to enable the USB
1516 Supported are USB Keyboards and USB Floppy drives
1518 MPC5200 USB requires additional defines:
1520 for 528 MHz Clock: 0x0001bbbb
1524 for differential drivers: 0x00001000
1525 for single ended drivers: 0x00005000
1526 for differential drivers on PSC3: 0x00000100
1527 for single ended drivers on PSC3: 0x00004100
1528 CONFIG_SYS_USB_EVENT_POLL
1529 May be defined to allow interrupt polling
1530 instead of using asynchronous interrupts
1532 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1533 txfilltuning field in the EHCI controller on reset.
1535 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1536 HW module registers.
1539 Define the below if you wish to use the USB console.
1540 Once firmware is rebuilt from a serial console issue the
1541 command "setenv stdin usbtty; setenv stdout usbtty" and
1542 attach your USB cable. The Unix command "dmesg" should print
1543 it has found a new device. The environment variable usbtty
1544 can be set to gserial or cdc_acm to enable your device to
1545 appear to a USB host as a Linux gserial device or a
1546 Common Device Class Abstract Control Model serial device.
1547 If you select usbtty = gserial you should be able to enumerate
1549 # modprobe usbserial vendor=0xVendorID product=0xProductID
1550 else if using cdc_acm, simply setting the environment
1551 variable usbtty to be cdc_acm should suffice. The following
1552 might be defined in YourBoardName.h
1555 Define this to build a UDC device
1558 Define this to have a tty type of device available to
1559 talk to the UDC device
1562 Define this to enable the high speed support for usb
1563 device and usbtty. If this feature is enabled, a routine
1564 int is_usbd_high_speed(void)
1565 also needs to be defined by the driver to dynamically poll
1566 whether the enumeration has succeded at high speed or full
1569 CONFIG_SYS_CONSOLE_IS_IN_ENV
1570 Define this if you want stdin, stdout &/or stderr to
1574 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1575 Derive USB clock from external clock "blah"
1576 - CONFIG_SYS_USB_EXTC_CLK 0x02
1578 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1579 Derive USB clock from brgclk
1580 - CONFIG_SYS_USB_BRG_CLK 0x04
1582 If you have a USB-IF assigned VendorID then you may wish to
1583 define your own vendor specific values either in BoardName.h
1584 or directly in usbd_vendor_info.h. If you don't define
1585 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1586 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1587 should pretend to be a Linux device to it's target host.
1589 CONFIG_USBD_MANUFACTURER
1590 Define this string as the name of your company for
1591 - CONFIG_USBD_MANUFACTURER "my company"
1593 CONFIG_USBD_PRODUCT_NAME
1594 Define this string as the name of your product
1595 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1597 CONFIG_USBD_VENDORID
1598 Define this as your assigned Vendor ID from the USB
1599 Implementors Forum. This *must* be a genuine Vendor ID
1600 to avoid polluting the USB namespace.
1601 - CONFIG_USBD_VENDORID 0xFFFF
1603 CONFIG_USBD_PRODUCTID
1604 Define this as the unique Product ID
1606 - CONFIG_USBD_PRODUCTID 0xFFFF
1608 - ULPI Layer Support:
1609 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1610 the generic ULPI layer. The generic layer accesses the ULPI PHY
1611 via the platform viewport, so you need both the genric layer and
1612 the viewport enabled. Currently only Chipidea/ARC based
1613 viewport is supported.
1614 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1615 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1616 If your ULPI phy needs a different reference clock than the
1617 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1618 the appropriate value in Hz.
1621 The MMC controller on the Intel PXA is supported. To
1622 enable this define CONFIG_MMC. The MMC can be
1623 accessed from the boot prompt by mapping the device
1624 to physical memory similar to flash. Command line is
1625 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1626 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1629 Support for Renesas on-chip MMCIF controller
1631 CONFIG_SH_MMCIF_ADDR
1632 Define the base address of MMCIF registers
1635 Define the clock frequency for MMCIF
1638 Enable the generic MMC driver
1640 CONFIG_SUPPORT_EMMC_BOOT
1641 Enable some additional features of the eMMC boot partitions.
1643 CONFIG_SUPPORT_EMMC_RPMB
1644 Enable the commands for reading, writing and programming the
1645 key for the Replay Protection Memory Block partition in eMMC.
1647 - USB Device Firmware Update (DFU) class support:
1648 CONFIG_USB_FUNCTION_DFU
1649 This enables the USB portion of the DFU USB class
1652 This enables the command "dfu" which is used to have
1653 U-Boot create a DFU class device via USB. This command
1654 requires that the "dfu_alt_info" environment variable be
1655 set and define the alt settings to expose to the host.
1658 This enables support for exposing (e)MMC devices via DFU.
1661 This enables support for exposing NAND devices via DFU.
1664 This enables support for exposing RAM via DFU.
1665 Note: DFU spec refer to non-volatile memory usage, but
1666 allow usages beyond the scope of spec - here RAM usage,
1667 one that would help mostly the developer.
1669 CONFIG_SYS_DFU_DATA_BUF_SIZE
1670 Dfu transfer uses a buffer before writing data to the
1671 raw storage device. Make the size (in bytes) of this buffer
1672 configurable. The size of this buffer is also configurable
1673 through the "dfu_bufsiz" environment variable.
1675 CONFIG_SYS_DFU_MAX_FILE_SIZE
1676 When updating files rather than the raw storage device,
1677 we use a static buffer to copy the file into and then write
1678 the buffer once we've been given the whole file. Define
1679 this to the maximum filesize (in bytes) for the buffer.
1680 Default is 4 MiB if undefined.
1682 DFU_DEFAULT_POLL_TIMEOUT
1683 Poll timeout [ms], is the timeout a device can send to the
1684 host. The host must wait for this timeout before sending
1685 a subsequent DFU_GET_STATUS request to the device.
1687 DFU_MANIFEST_POLL_TIMEOUT
1688 Poll timeout [ms], which the device sends to the host when
1689 entering dfuMANIFEST state. Host waits this timeout, before
1690 sending again an USB request to the device.
1692 - USB Device Android Fastboot support:
1693 CONFIG_USB_FUNCTION_FASTBOOT
1694 This enables the USB part of the fastboot gadget
1697 This enables the command "fastboot" which enables the Android
1698 fastboot mode for the platform's USB device. Fastboot is a USB
1699 protocol for downloading images, flashing and device control
1700 used on Android devices.
1701 See doc/README.android-fastboot for more information.
1703 CONFIG_ANDROID_BOOT_IMAGE
1704 This enables support for booting images which use the Android
1705 image format header.
1707 CONFIG_FASTBOOT_BUF_ADDR
1708 The fastboot protocol requires a large memory buffer for
1709 downloads. Define this to the starting RAM address to use for
1712 CONFIG_FASTBOOT_BUF_SIZE
1713 The fastboot protocol requires a large memory buffer for
1714 downloads. This buffer should be as large as possible for a
1715 platform. Define this to the size available RAM for fastboot.
1717 CONFIG_FASTBOOT_FLASH
1718 The fastboot protocol includes a "flash" command for writing
1719 the downloaded image to a non-volatile storage device. Define
1720 this to enable the "fastboot flash" command.
1722 CONFIG_FASTBOOT_FLASH_MMC_DEV
1723 The fastboot "flash" command requires additional information
1724 regarding the non-volatile storage device. Define this to
1725 the eMMC device that fastboot should use to store the image.
1727 CONFIG_FASTBOOT_GPT_NAME
1728 The fastboot "flash" command supports writing the downloaded
1729 image to the Protective MBR and the Primary GUID Partition
1730 Table. (Additionally, this downloaded image is post-processed
1731 to generate and write the Backup GUID Partition Table.)
1732 This occurs when the specified "partition name" on the
1733 "fastboot flash" command line matches this value.
1734 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1736 - Journaling Flash filesystem support:
1737 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1738 CONFIG_JFFS2_NAND_DEV
1739 Define these for a default partition on a NAND device
1741 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1742 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1743 Define these for a default partition on a NOR device
1745 CONFIG_SYS_JFFS_CUSTOM_PART
1746 Define this to create an own partition. You have to provide a
1747 function struct part_info* jffs2_part_info(int part_num)
1749 If you define only one JFFS2 partition you may also want to
1750 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1751 to disable the command chpart. This is the default when you
1752 have not defined a custom partition
1754 - FAT(File Allocation Table) filesystem write function support:
1757 Define this to enable support for saving memory data as a
1758 file in FAT formatted partition.
1760 This will also enable the command "fatwrite" enabling the
1761 user to write files to FAT.
1763 CBFS (Coreboot Filesystem) support
1766 Define this to enable support for reading from a Coreboot
1767 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1770 - FAT(File Allocation Table) filesystem cluster size:
1771 CONFIG_FS_FAT_MAX_CLUSTSIZE
1773 Define the max cluster size for fat operations else
1774 a default value of 65536 will be defined.
1779 Define this to enable standard (PC-Style) keyboard
1783 Standard PC keyboard driver with US (is default) and
1784 GERMAN key layout (switch via environment 'keymap=de') support.
1785 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1786 for cfb_console. Supports cursor blinking.
1789 Enables a Chrome OS keyboard using the CROS_EC interface.
1790 This uses CROS_EC to communicate with a second microcontroller
1791 which provides key scans on request.
1796 Define this to enable video support (for output to
1799 CONFIG_VIDEO_CT69000
1801 Enable Chips & Technologies 69000 Video chip
1803 CONFIG_VIDEO_SMI_LYNXEM
1804 Enable Silicon Motion SMI 712/710/810 Video chip. The
1805 video output is selected via environment 'videoout'
1806 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1809 For the CT69000 and SMI_LYNXEM drivers, videomode is
1810 selected via environment 'videomode'. Two different ways
1812 - "videomode=num" 'num' is a standard LiLo mode numbers.
1813 Following standard modes are supported (* is default):
1815 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1816 -------------+---------------------------------------------
1817 8 bits | 0x301* 0x303 0x305 0x161 0x307
1818 15 bits | 0x310 0x313 0x316 0x162 0x319
1819 16 bits | 0x311 0x314 0x317 0x163 0x31A
1820 24 bits | 0x312 0x315 0x318 ? 0x31B
1821 -------------+---------------------------------------------
1822 (i.e. setenv videomode 317; saveenv; reset;)
1824 - "videomode=bootargs" all the video parameters are parsed
1825 from the bootargs. (See drivers/video/videomodes.c)
1828 CONFIG_VIDEO_SED13806
1829 Enable Epson SED13806 driver. This driver supports 8bpp
1830 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1831 or CONFIG_VIDEO_SED13806_16BPP
1834 Enable the Freescale DIU video driver. Reference boards for
1835 SOCs that have a DIU should define this macro to enable DIU
1836 support, and should also define these other macros:
1842 CONFIG_VIDEO_SW_CURSOR
1843 CONFIG_VGA_AS_SINGLE_DEVICE
1845 CONFIG_VIDEO_BMP_LOGO
1847 The DIU driver will look for the 'video-mode' environment
1848 variable, and if defined, enable the DIU as a console during
1849 boot. See the documentation file README.video for a
1850 description of this variable.
1856 Define this to enable a custom keyboard support.
1857 This simply calls drv_keyboard_init() which must be
1858 defined in your board-specific files.
1859 The only board using this so far is RBC823.
1861 - LCD Support: CONFIG_LCD
1863 Define this to enable LCD support (for output to LCD
1864 display); also select one of the supported displays
1865 by defining one of these:
1869 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1871 CONFIG_NEC_NL6448AC33:
1873 NEC NL6448AC33-18. Active, color, single scan.
1875 CONFIG_NEC_NL6448BC20
1877 NEC NL6448BC20-08. 6.5", 640x480.
1878 Active, color, single scan.
1880 CONFIG_NEC_NL6448BC33_54
1882 NEC NL6448BC33-54. 10.4", 640x480.
1883 Active, color, single scan.
1887 Sharp 320x240. Active, color, single scan.
1888 It isn't 16x9, and I am not sure what it is.
1890 CONFIG_SHARP_LQ64D341
1892 Sharp LQ64D341 display, 640x480.
1893 Active, color, single scan.
1897 HLD1045 display, 640x480.
1898 Active, color, single scan.
1902 Optrex CBL50840-2 NF-FW 99 22 M5
1904 Hitachi LMG6912RPFC-00T
1908 320x240. Black & white.
1910 Normally display is black on white background; define
1911 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1913 CONFIG_LCD_ALIGNMENT
1915 Normally the LCD is page-aligned (typically 4KB). If this is
1916 defined then the LCD will be aligned to this value instead.
1917 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1918 here, since it is cheaper to change data cache settings on
1919 a per-section basis.
1921 CONFIG_CONSOLE_SCROLL_LINES
1923 When the console need to be scrolled, this is the number of
1924 lines to scroll by. It defaults to 1. Increasing this makes
1925 the console jump but can help speed up operation when scrolling
1930 Sometimes, for example if the display is mounted in portrait
1931 mode or even if it's mounted landscape but rotated by 180degree,
1932 we need to rotate our content of the display relative to the
1933 framebuffer, so that user can read the messages which are
1935 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1936 initialized with a given rotation from "vl_rot" out of
1937 "vidinfo_t" which is provided by the board specific code.
1938 The value for vl_rot is coded as following (matching to
1939 fbcon=rotate:<n> linux-kernel commandline):
1940 0 = no rotation respectively 0 degree
1941 1 = 90 degree rotation
1942 2 = 180 degree rotation
1943 3 = 270 degree rotation
1945 If CONFIG_LCD_ROTATION is not defined, the console will be
1946 initialized with 0degree rotation.
1950 Support drawing of RLE8-compressed bitmaps on the LCD.
1954 Enables an 'i2c edid' command which can read EDID
1955 information over I2C from an attached LCD display.
1957 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1959 If this option is set, the environment is checked for
1960 a variable "splashimage". If found, the usual display
1961 of logo, copyright and system information on the LCD
1962 is suppressed and the BMP image at the address
1963 specified in "splashimage" is loaded instead. The
1964 console is redirected to the "nulldev", too. This
1965 allows for a "silent" boot where a splash screen is
1966 loaded very quickly after power-on.
1968 CONFIG_SPLASHIMAGE_GUARD
1970 If this option is set, then U-Boot will prevent the environment
1971 variable "splashimage" from being set to a problematic address
1972 (see README.displaying-bmps).
1973 This option is useful for targets where, due to alignment
1974 restrictions, an improperly aligned BMP image will cause a data
1975 abort. If you think you will not have problems with unaligned
1976 accesses (for example because your toolchain prevents them)
1977 there is no need to set this option.
1979 CONFIG_SPLASH_SCREEN_ALIGN
1981 If this option is set the splash image can be freely positioned
1982 on the screen. Environment variable "splashpos" specifies the
1983 position as "x,y". If a positive number is given it is used as
1984 number of pixel from left/top. If a negative number is given it
1985 is used as number of pixel from right/bottom. You can also
1986 specify 'm' for centering the image.
1989 setenv splashpos m,m
1990 => image at center of screen
1992 setenv splashpos 30,20
1993 => image at x = 30 and y = 20
1995 setenv splashpos -10,m
1996 => vertically centered image
1997 at x = dspWidth - bmpWidth - 9
1999 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2001 If this option is set, additionally to standard BMP
2002 images, gzipped BMP images can be displayed via the
2003 splashscreen support or the bmp command.
2005 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2007 If this option is set, 8-bit RLE compressed BMP images
2008 can be displayed via the splashscreen support or the
2011 - Do compressing for memory range:
2014 If this option is set, it would use zlib deflate method
2015 to compress the specified memory at its best effort.
2017 - Compression support:
2020 Enabled by default to support gzip compressed images.
2024 If this option is set, support for bzip2 compressed
2025 images is included. If not, only uncompressed and gzip
2026 compressed images are supported.
2028 NOTE: the bzip2 algorithm requires a lot of RAM, so
2029 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2034 If this option is set, support for lzma compressed
2037 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2038 requires an amount of dynamic memory that is given by the
2041 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2043 Where lc and lp stand for, respectively, Literal context bits
2044 and Literal pos bits.
2046 This value is upper-bounded by 14MB in the worst case. Anyway,
2047 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2048 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2049 a very small buffer.
2051 Use the lzmainfo tool to determinate the lc and lp values and
2052 then calculate the amount of needed dynamic memory (ensuring
2053 the appropriate CONFIG_SYS_MALLOC_LEN value).
2057 If this option is set, support for LZO compressed images
2063 The address of PHY on MII bus.
2065 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2067 The clock frequency of the MII bus
2071 If this option is set, support for speed/duplex
2072 detection of gigabit PHY is included.
2074 CONFIG_PHY_RESET_DELAY
2076 Some PHY like Intel LXT971A need extra delay after
2077 reset before any MII register access is possible.
2078 For such PHY, set this option to the usec delay
2079 required. (minimum 300usec for LXT971A)
2081 CONFIG_PHY_CMD_DELAY (ppc4xx)
2083 Some PHY like Intel LXT971A need extra delay after
2084 command issued before MII status register can be read
2089 Define a default value for the IP address to use for
2090 the default Ethernet interface, in case this is not
2091 determined through e.g. bootp.
2092 (Environment variable "ipaddr")
2094 - Server IP address:
2097 Defines a default value for the IP address of a TFTP
2098 server to contact when using the "tftboot" command.
2099 (Environment variable "serverip")
2101 CONFIG_KEEP_SERVERADDR
2103 Keeps the server's MAC address, in the env 'serveraddr'
2104 for passing to bootargs (like Linux's netconsole option)
2106 - Gateway IP address:
2109 Defines a default value for the IP address of the
2110 default router where packets to other networks are
2112 (Environment variable "gatewayip")
2117 Defines a default value for the subnet mask (or
2118 routing prefix) which is used to determine if an IP
2119 address belongs to the local subnet or needs to be
2120 forwarded through a router.
2121 (Environment variable "netmask")
2123 - Multicast TFTP Mode:
2126 Defines whether you want to support multicast TFTP as per
2127 rfc-2090; for example to work with atftp. Lets lots of targets
2128 tftp down the same boot image concurrently. Note: the Ethernet
2129 driver in use must provide a function: mcast() to join/leave a
2132 - BOOTP Recovery Mode:
2133 CONFIG_BOOTP_RANDOM_DELAY
2135 If you have many targets in a network that try to
2136 boot using BOOTP, you may want to avoid that all
2137 systems send out BOOTP requests at precisely the same
2138 moment (which would happen for instance at recovery
2139 from a power failure, when all systems will try to
2140 boot, thus flooding the BOOTP server. Defining
2141 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2142 inserted before sending out BOOTP requests. The
2143 following delays are inserted then:
2145 1st BOOTP request: delay 0 ... 1 sec
2146 2nd BOOTP request: delay 0 ... 2 sec
2147 3rd BOOTP request: delay 0 ... 4 sec
2149 BOOTP requests: delay 0 ... 8 sec
2151 CONFIG_BOOTP_ID_CACHE_SIZE
2153 BOOTP packets are uniquely identified using a 32-bit ID. The
2154 server will copy the ID from client requests to responses and
2155 U-Boot will use this to determine if it is the destination of
2156 an incoming response. Some servers will check that addresses
2157 aren't in use before handing them out (usually using an ARP
2158 ping) and therefore take up to a few hundred milliseconds to
2159 respond. Network congestion may also influence the time it
2160 takes for a response to make it back to the client. If that
2161 time is too long, U-Boot will retransmit requests. In order
2162 to allow earlier responses to still be accepted after these
2163 retransmissions, U-Boot's BOOTP client keeps a small cache of
2164 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2165 cache. The default is to keep IDs for up to four outstanding
2166 requests. Increasing this will allow U-Boot to accept offers
2167 from a BOOTP client in networks with unusually high latency.
2169 - DHCP Advanced Options:
2170 You can fine tune the DHCP functionality by defining
2171 CONFIG_BOOTP_* symbols:
2173 CONFIG_BOOTP_SUBNETMASK
2174 CONFIG_BOOTP_GATEWAY
2175 CONFIG_BOOTP_HOSTNAME
2176 CONFIG_BOOTP_NISDOMAIN
2177 CONFIG_BOOTP_BOOTPATH
2178 CONFIG_BOOTP_BOOTFILESIZE
2181 CONFIG_BOOTP_SEND_HOSTNAME
2182 CONFIG_BOOTP_NTPSERVER
2183 CONFIG_BOOTP_TIMEOFFSET
2184 CONFIG_BOOTP_VENDOREX
2185 CONFIG_BOOTP_MAY_FAIL
2187 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2188 environment variable, not the BOOTP server.
2190 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2191 after the configured retry count, the call will fail
2192 instead of starting over. This can be used to fail over
2193 to Link-local IP address configuration if the DHCP server
2196 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2197 serverip from a DHCP server, it is possible that more
2198 than one DNS serverip is offered to the client.
2199 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2200 serverip will be stored in the additional environment
2201 variable "dnsip2". The first DNS serverip is always
2202 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2205 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2206 to do a dynamic update of a DNS server. To do this, they
2207 need the hostname of the DHCP requester.
2208 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2209 of the "hostname" environment variable is passed as
2210 option 12 to the DHCP server.
2212 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2214 A 32bit value in microseconds for a delay between
2215 receiving a "DHCP Offer" and sending the "DHCP Request".
2216 This fixes a problem with certain DHCP servers that don't
2217 respond 100% of the time to a "DHCP request". E.g. On an
2218 AT91RM9200 processor running at 180MHz, this delay needed
2219 to be *at least* 15,000 usec before a Windows Server 2003
2220 DHCP server would reply 100% of the time. I recommend at
2221 least 50,000 usec to be safe. The alternative is to hope
2222 that one of the retries will be successful but note that
2223 the DHCP timeout and retry process takes a longer than
2226 - Link-local IP address negotiation:
2227 Negotiate with other link-local clients on the local network
2228 for an address that doesn't require explicit configuration.
2229 This is especially useful if a DHCP server cannot be guaranteed
2230 to exist in all environments that the device must operate.
2232 See doc/README.link-local for more information.
2235 CONFIG_CDP_DEVICE_ID
2237 The device id used in CDP trigger frames.
2239 CONFIG_CDP_DEVICE_ID_PREFIX
2241 A two character string which is prefixed to the MAC address
2246 A printf format string which contains the ascii name of
2247 the port. Normally is set to "eth%d" which sets
2248 eth0 for the first Ethernet, eth1 for the second etc.
2250 CONFIG_CDP_CAPABILITIES
2252 A 32bit integer which indicates the device capabilities;
2253 0x00000010 for a normal host which does not forwards.
2257 An ascii string containing the version of the software.
2261 An ascii string containing the name of the platform.
2265 A 32bit integer sent on the trigger.
2267 CONFIG_CDP_POWER_CONSUMPTION
2269 A 16bit integer containing the power consumption of the
2270 device in .1 of milliwatts.
2272 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2274 A byte containing the id of the VLAN.
2276 - Status LED: CONFIG_STATUS_LED
2278 Several configurations allow to display the current
2279 status using a LED. For instance, the LED will blink
2280 fast while running U-Boot code, stop blinking as
2281 soon as a reply to a BOOTP request was received, and
2282 start blinking slow once the Linux kernel is running
2283 (supported by a status LED driver in the Linux
2284 kernel). Defining CONFIG_STATUS_LED enables this
2290 The status LED can be connected to a GPIO pin.
2291 In such cases, the gpio_led driver can be used as a
2292 status LED backend implementation. Define CONFIG_GPIO_LED
2293 to include the gpio_led driver in the U-Boot binary.
2295 CONFIG_GPIO_LED_INVERTED_TABLE
2296 Some GPIO connected LEDs may have inverted polarity in which
2297 case the GPIO high value corresponds to LED off state and
2298 GPIO low value corresponds to LED on state.
2299 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2300 with a list of GPIO LEDs that have inverted polarity.
2302 - CAN Support: CONFIG_CAN_DRIVER
2304 Defining CONFIG_CAN_DRIVER enables CAN driver support
2305 on those systems that support this (optional)
2306 feature, like the TQM8xxL modules.
2308 - I2C Support: CONFIG_SYS_I2C
2310 This enable the NEW i2c subsystem, and will allow you to use
2311 i2c commands at the u-boot command line (as long as you set
2312 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2313 based realtime clock chips or other i2c devices. See
2314 common/cmd_i2c.c for a description of the command line
2317 ported i2c driver to the new framework:
2318 - drivers/i2c/soft_i2c.c:
2319 - activate first bus with CONFIG_SYS_I2C_SOFT define
2320 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2321 for defining speed and slave address
2322 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2323 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2324 for defining speed and slave address
2325 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2326 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2327 for defining speed and slave address
2328 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2329 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2330 for defining speed and slave address
2332 - drivers/i2c/fsl_i2c.c:
2333 - activate i2c driver with CONFIG_SYS_I2C_FSL
2334 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2335 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2336 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2338 - If your board supports a second fsl i2c bus, define
2339 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2340 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2341 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2344 - drivers/i2c/tegra_i2c.c:
2345 - activate this driver with CONFIG_SYS_I2C_TEGRA
2346 - This driver adds 4 i2c buses with a fix speed from
2347 100000 and the slave addr 0!
2349 - drivers/i2c/ppc4xx_i2c.c
2350 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2351 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2352 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2354 - drivers/i2c/i2c_mxc.c
2355 - activate this driver with CONFIG_SYS_I2C_MXC
2356 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2357 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2358 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2359 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2360 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2361 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2362 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2363 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2364 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2365 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2366 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2367 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2368 If those defines are not set, default value is 100000
2369 for speed, and 0 for slave.
2371 - drivers/i2c/rcar_i2c.c:
2372 - activate this driver with CONFIG_SYS_I2C_RCAR
2373 - This driver adds 4 i2c buses
2375 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2376 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2377 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2378 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2379 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2380 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2381 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2382 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2383 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2385 - drivers/i2c/sh_i2c.c:
2386 - activate this driver with CONFIG_SYS_I2C_SH
2387 - This driver adds from 2 to 5 i2c buses
2389 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2390 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2391 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2392 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2393 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2394 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2395 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2396 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2397 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2398 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2399 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2400 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2401 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2403 - drivers/i2c/omap24xx_i2c.c
2404 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2405 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2406 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2407 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2408 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2409 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2410 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2411 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2412 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2413 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2414 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2416 - drivers/i2c/zynq_i2c.c
2417 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2418 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2419 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2421 - drivers/i2c/s3c24x0_i2c.c:
2422 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2423 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2424 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2425 with a fix speed from 100000 and the slave addr 0!
2427 - drivers/i2c/ihs_i2c.c
2428 - activate this driver with CONFIG_SYS_I2C_IHS
2429 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2430 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2431 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2432 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2433 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2434 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2435 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2436 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2437 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2438 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2439 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2440 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2441 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2442 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2443 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2444 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2445 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2446 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2447 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2448 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2449 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2453 CONFIG_SYS_NUM_I2C_BUSES
2454 Hold the number of i2c buses you want to use. If you
2455 don't use/have i2c muxes on your i2c bus, this
2456 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2459 CONFIG_SYS_I2C_DIRECT_BUS
2460 define this, if you don't use i2c muxes on your hardware.
2461 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2464 CONFIG_SYS_I2C_MAX_HOPS
2465 define how many muxes are maximal consecutively connected
2466 on one i2c bus. If you not use i2c muxes, omit this
2469 CONFIG_SYS_I2C_BUSES
2470 hold a list of buses you want to use, only used if
2471 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2472 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2473 CONFIG_SYS_NUM_I2C_BUSES = 9:
2475 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2476 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2477 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2478 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2479 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2480 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2481 {1, {I2C_NULL_HOP}}, \
2482 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2483 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2487 bus 0 on adapter 0 without a mux
2488 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2489 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2490 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2491 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2492 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2493 bus 6 on adapter 1 without a mux
2494 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2495 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2497 If you do not have i2c muxes on your board, omit this define.
2499 - Legacy I2C Support: CONFIG_HARD_I2C
2501 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2502 provides the following compelling advantages:
2504 - more than one i2c adapter is usable
2505 - approved multibus support
2506 - better i2c mux support
2508 ** Please consider updating your I2C driver now. **
2510 These enable legacy I2C serial bus commands. Defining
2511 CONFIG_HARD_I2C will include the appropriate I2C driver
2512 for the selected CPU.
2514 This will allow you to use i2c commands at the u-boot
2515 command line (as long as you set CONFIG_CMD_I2C in
2516 CONFIG_COMMANDS) and communicate with i2c based realtime
2517 clock chips. See common/cmd_i2c.c for a description of the
2518 command line interface.
2520 CONFIG_HARD_I2C selects a hardware I2C controller.
2522 There are several other quantities that must also be
2523 defined when you define CONFIG_HARD_I2C.
2525 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2526 to be the frequency (in Hz) at which you wish your i2c bus
2527 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2528 the CPU's i2c node address).
2530 Now, the u-boot i2c code for the mpc8xx
2531 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2532 and so its address should therefore be cleared to 0 (See,
2533 eg, MPC823e User's Manual p.16-473). So, set
2534 CONFIG_SYS_I2C_SLAVE to 0.
2536 CONFIG_SYS_I2C_INIT_MPC5XXX
2538 When a board is reset during an i2c bus transfer
2539 chips might think that the current transfer is still
2540 in progress. Reset the slave devices by sending start
2541 commands until the slave device responds.
2543 That's all that's required for CONFIG_HARD_I2C.
2545 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2546 then the following macros need to be defined (examples are
2547 from include/configs/lwmon.h):
2551 (Optional). Any commands necessary to enable the I2C
2552 controller or configure ports.
2554 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2558 (Only for MPC8260 CPU). The I/O port to use (the code
2559 assumes both bits are on the same port). Valid values
2560 are 0..3 for ports A..D.
2564 The code necessary to make the I2C data line active
2565 (driven). If the data line is open collector, this
2568 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2572 The code necessary to make the I2C data line tri-stated
2573 (inactive). If the data line is open collector, this
2576 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2580 Code that returns true if the I2C data line is high,
2583 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2587 If <bit> is true, sets the I2C data line high. If it
2588 is false, it clears it (low).
2590 eg: #define I2C_SDA(bit) \
2591 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2592 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2596 If <bit> is true, sets the I2C clock line high. If it
2597 is false, it clears it (low).
2599 eg: #define I2C_SCL(bit) \
2600 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2601 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2605 This delay is invoked four times per clock cycle so this
2606 controls the rate of data transfer. The data rate thus
2607 is 1 / (I2C_DELAY * 4). Often defined to be something
2610 #define I2C_DELAY udelay(2)
2612 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2614 If your arch supports the generic GPIO framework (asm/gpio.h),
2615 then you may alternatively define the two GPIOs that are to be
2616 used as SCL / SDA. Any of the previous I2C_xxx macros will
2617 have GPIO-based defaults assigned to them as appropriate.
2619 You should define these to the GPIO value as given directly to
2620 the generic GPIO functions.
2622 CONFIG_SYS_I2C_INIT_BOARD
2624 When a board is reset during an i2c bus transfer
2625 chips might think that the current transfer is still
2626 in progress. On some boards it is possible to access
2627 the i2c SCLK line directly, either by using the
2628 processor pin as a GPIO or by having a second pin
2629 connected to the bus. If this option is defined a
2630 custom i2c_init_board() routine in boards/xxx/board.c
2631 is run early in the boot sequence.
2633 CONFIG_SYS_I2C_BOARD_LATE_INIT
2635 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2636 defined a custom i2c_board_late_init() routine in
2637 boards/xxx/board.c is run AFTER the operations in i2c_init()
2638 is completed. This callpoint can be used to unreset i2c bus
2639 using CPU i2c controller register accesses for CPUs whose i2c
2640 controller provide such a method. It is called at the end of
2641 i2c_init() to allow i2c_init operations to setup the i2c bus
2642 controller on the CPU (e.g. setting bus speed & slave address).
2644 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2646 This option enables configuration of bi_iic_fast[] flags
2647 in u-boot bd_info structure based on u-boot environment
2648 variable "i2cfast". (see also i2cfast)
2650 CONFIG_I2C_MULTI_BUS
2652 This option allows the use of multiple I2C buses, each of which
2653 must have a controller. At any point in time, only one bus is
2654 active. To switch to a different bus, use the 'i2c dev' command.
2655 Note that bus numbering is zero-based.
2657 CONFIG_SYS_I2C_NOPROBES
2659 This option specifies a list of I2C devices that will be skipped
2660 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2661 is set, specify a list of bus-device pairs. Otherwise, specify
2662 a 1D array of device addresses
2665 #undef CONFIG_I2C_MULTI_BUS
2666 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2668 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2670 #define CONFIG_I2C_MULTI_BUS
2671 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2673 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2675 CONFIG_SYS_SPD_BUS_NUM
2677 If defined, then this indicates the I2C bus number for DDR SPD.
2678 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2680 CONFIG_SYS_RTC_BUS_NUM
2682 If defined, then this indicates the I2C bus number for the RTC.
2683 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2685 CONFIG_SYS_DTT_BUS_NUM
2687 If defined, then this indicates the I2C bus number for the DTT.
2688 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2690 CONFIG_SYS_I2C_DTT_ADDR:
2692 If defined, specifies the I2C address of the DTT device.
2693 If not defined, then U-Boot uses predefined value for
2694 specified DTT device.
2696 CONFIG_SOFT_I2C_READ_REPEATED_START
2698 defining this will force the i2c_read() function in
2699 the soft_i2c driver to perform an I2C repeated start
2700 between writing the address pointer and reading the
2701 data. If this define is omitted the default behaviour
2702 of doing a stop-start sequence will be used. Most I2C
2703 devices can use either method, but some require one or
2706 - SPI Support: CONFIG_SPI
2708 Enables SPI driver (so far only tested with
2709 SPI EEPROM, also an instance works with Crystal A/D and
2710 D/As on the SACSng board)
2714 Enables the driver for SPI controller on SuperH. Currently
2715 only SH7757 is supported.
2719 Enables extended (16-bit) SPI EEPROM addressing.
2720 (symmetrical to CONFIG_I2C_X)
2724 Enables a software (bit-bang) SPI driver rather than
2725 using hardware support. This is a general purpose
2726 driver that only requires three general I/O port pins
2727 (two outputs, one input) to function. If this is
2728 defined, the board configuration must define several
2729 SPI configuration items (port pins to use, etc). For
2730 an example, see include/configs/sacsng.h.
2734 Enables a hardware SPI driver for general-purpose reads
2735 and writes. As with CONFIG_SOFT_SPI, the board configuration
2736 must define a list of chip-select function pointers.
2737 Currently supported on some MPC8xxx processors. For an
2738 example, see include/configs/mpc8349emds.h.
2742 Enables the driver for the SPI controllers on i.MX and MXC
2743 SoCs. Currently i.MX31/35/51 are supported.
2745 CONFIG_SYS_SPI_MXC_WAIT
2746 Timeout for waiting until spi transfer completed.
2747 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2749 - FPGA Support: CONFIG_FPGA
2751 Enables FPGA subsystem.
2753 CONFIG_FPGA_<vendor>
2755 Enables support for specific chip vendors.
2758 CONFIG_FPGA_<family>
2760 Enables support for FPGA family.
2761 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2765 Specify the number of FPGA devices to support.
2767 CONFIG_CMD_FPGA_LOADMK
2769 Enable support for fpga loadmk command
2771 CONFIG_CMD_FPGA_LOADP
2773 Enable support for fpga loadp command - load partial bitstream
2775 CONFIG_CMD_FPGA_LOADBP
2777 Enable support for fpga loadbp command - load partial bitstream
2780 CONFIG_SYS_FPGA_PROG_FEEDBACK
2782 Enable printing of hash marks during FPGA configuration.
2784 CONFIG_SYS_FPGA_CHECK_BUSY
2786 Enable checks on FPGA configuration interface busy
2787 status by the configuration function. This option
2788 will require a board or device specific function to
2793 If defined, a function that provides delays in the FPGA
2794 configuration driver.
2796 CONFIG_SYS_FPGA_CHECK_CTRLC
2797 Allow Control-C to interrupt FPGA configuration
2799 CONFIG_SYS_FPGA_CHECK_ERROR
2801 Check for configuration errors during FPGA bitfile
2802 loading. For example, abort during Virtex II
2803 configuration if the INIT_B line goes low (which
2804 indicated a CRC error).
2806 CONFIG_SYS_FPGA_WAIT_INIT
2808 Maximum time to wait for the INIT_B line to de-assert
2809 after PROB_B has been de-asserted during a Virtex II
2810 FPGA configuration sequence. The default time is 500
2813 CONFIG_SYS_FPGA_WAIT_BUSY
2815 Maximum time to wait for BUSY to de-assert during
2816 Virtex II FPGA configuration. The default is 5 ms.
2818 CONFIG_SYS_FPGA_WAIT_CONFIG
2820 Time to wait after FPGA configuration. The default is
2823 - Configuration Management:
2826 Some SoCs need special image types (e.g. U-Boot binary
2827 with a special header) as build targets. By defining
2828 CONFIG_BUILD_TARGET in the SoC / board header, this
2829 special image will be automatically built upon calling
2834 If defined, this string will be added to the U-Boot
2835 version information (U_BOOT_VERSION)
2837 - Vendor Parameter Protection:
2839 U-Boot considers the values of the environment
2840 variables "serial#" (Board Serial Number) and
2841 "ethaddr" (Ethernet Address) to be parameters that
2842 are set once by the board vendor / manufacturer, and
2843 protects these variables from casual modification by
2844 the user. Once set, these variables are read-only,
2845 and write or delete attempts are rejected. You can
2846 change this behaviour:
2848 If CONFIG_ENV_OVERWRITE is #defined in your config
2849 file, the write protection for vendor parameters is
2850 completely disabled. Anybody can change or delete
2853 Alternatively, if you define _both_ an ethaddr in the
2854 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2855 Ethernet address is installed in the environment,
2856 which can be changed exactly ONCE by the user. [The
2857 serial# is unaffected by this, i. e. it remains
2860 The same can be accomplished in a more flexible way
2861 for any variable by configuring the type of access
2862 to allow for those variables in the ".flags" variable
2863 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2868 Define this variable to enable the reservation of
2869 "protected RAM", i. e. RAM which is not overwritten
2870 by U-Boot. Define CONFIG_PRAM to hold the number of
2871 kB you want to reserve for pRAM. You can overwrite
2872 this default value by defining an environment
2873 variable "pram" to the number of kB you want to
2874 reserve. Note that the board info structure will
2875 still show the full amount of RAM. If pRAM is
2876 reserved, a new environment variable "mem" will
2877 automatically be defined to hold the amount of
2878 remaining RAM in a form that can be passed as boot
2879 argument to Linux, for instance like that:
2881 setenv bootargs ... mem=\${mem}
2884 This way you can tell Linux not to use this memory,
2885 either, which results in a memory region that will
2886 not be affected by reboots.
2888 *WARNING* If your board configuration uses automatic
2889 detection of the RAM size, you must make sure that
2890 this memory test is non-destructive. So far, the
2891 following board configurations are known to be
2894 IVMS8, IVML24, SPD8xx, TQM8xxL,
2895 HERMES, IP860, RPXlite, LWMON,
2898 - Access to physical memory region (> 4GB)
2899 Some basic support is provided for operations on memory not
2900 normally accessible to U-Boot - e.g. some architectures
2901 support access to more than 4GB of memory on 32-bit
2902 machines using physical address extension or similar.
2903 Define CONFIG_PHYSMEM to access this basic support, which
2904 currently only supports clearing the memory.
2909 Define this variable to stop the system in case of a
2910 fatal error, so that you have to reset it manually.
2911 This is probably NOT a good idea for an embedded
2912 system where you want the system to reboot
2913 automatically as fast as possible, but it may be
2914 useful during development since you can try to debug
2915 the conditions that lead to the situation.
2917 CONFIG_NET_RETRY_COUNT
2919 This variable defines the number of retries for
2920 network operations like ARP, RARP, TFTP, or BOOTP
2921 before giving up the operation. If not defined, a
2922 default value of 5 is used.
2926 Timeout waiting for an ARP reply in milliseconds.
2930 Timeout in milliseconds used in NFS protocol.
2931 If you encounter "ERROR: Cannot umount" in nfs command,
2932 try longer timeout such as
2933 #define CONFIG_NFS_TIMEOUT 10000UL
2935 - Command Interpreter:
2936 CONFIG_AUTO_COMPLETE
2938 Enable auto completion of commands using TAB.
2940 CONFIG_SYS_PROMPT_HUSH_PS2
2942 This defines the secondary prompt string, which is
2943 printed when the command interpreter needs more input
2944 to complete a command. Usually "> ".
2948 In the current implementation, the local variables
2949 space and global environment variables space are
2950 separated. Local variables are those you define by
2951 simply typing `name=value'. To access a local
2952 variable later on, you have write `$name' or
2953 `${name}'; to execute the contents of a variable
2954 directly type `$name' at the command prompt.
2956 Global environment variables are those you use
2957 setenv/printenv to work with. To run a command stored
2958 in such a variable, you need to use the run command,
2959 and you must not use the '$' sign to access them.
2961 To store commands and special characters in a
2962 variable, please use double quotation marks
2963 surrounding the whole text of the variable, instead
2964 of the backslashes before semicolons and special
2967 - Command Line Editing and History:
2968 CONFIG_CMDLINE_EDITING
2970 Enable editing and History functions for interactive
2971 command line input operations
2973 - Default Environment:
2974 CONFIG_EXTRA_ENV_SETTINGS
2976 Define this to contain any number of null terminated
2977 strings (variable = value pairs) that will be part of
2978 the default environment compiled into the boot image.
2980 For example, place something like this in your
2981 board's config file:
2983 #define CONFIG_EXTRA_ENV_SETTINGS \
2987 Warning: This method is based on knowledge about the
2988 internal format how the environment is stored by the
2989 U-Boot code. This is NOT an official, exported
2990 interface! Although it is unlikely that this format
2991 will change soon, there is no guarantee either.
2992 You better know what you are doing here.
2994 Note: overly (ab)use of the default environment is
2995 discouraged. Make sure to check other ways to preset
2996 the environment like the "source" command or the
2999 CONFIG_ENV_VARS_UBOOT_CONFIG
3001 Define this in order to add variables describing the
3002 U-Boot build configuration to the default environment.
3003 These will be named arch, cpu, board, vendor, and soc.
3005 Enabling this option will cause the following to be defined:
3013 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3015 Define this in order to add variables describing certain
3016 run-time determined information about the hardware to the
3017 environment. These will be named board_name, board_rev.
3019 CONFIG_DELAY_ENVIRONMENT
3021 Normally the environment is loaded when the board is
3022 initialised so that it is available to U-Boot. This inhibits
3023 that so that the environment is not available until
3024 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3025 this is instead controlled by the value of
3026 /config/load-environment.
3028 - Parallel Flash support:
3031 Traditionally U-boot was run on systems with parallel NOR
3032 flash. This option is used to disable support for parallel NOR
3033 flash. This option should be defined if the board does not have
3036 If this option is not defined one of the generic flash drivers
3037 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3038 selected or the board must provide an implementation of the
3039 flash API (see include/flash.h).
3041 - DataFlash Support:
3042 CONFIG_HAS_DATAFLASH
3044 Defining this option enables DataFlash features and
3045 allows to read/write in Dataflash via the standard
3048 - Serial Flash support
3051 Defining this option enables SPI flash commands
3052 'sf probe/read/write/erase/update'.
3054 Usage requires an initial 'probe' to define the serial
3055 flash parameters, followed by read/write/erase/update
3058 The following defaults may be provided by the platform
3059 to handle the common case when only a single serial
3060 flash is present on the system.
3062 CONFIG_SF_DEFAULT_BUS Bus identifier
3063 CONFIG_SF_DEFAULT_CS Chip-select
3064 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3065 CONFIG_SF_DEFAULT_SPEED in Hz
3069 Define this option to include a destructive SPI flash
3072 CONFIG_SF_DUAL_FLASH Dual flash memories
3074 Define this option to use dual flash support where two flash
3075 memories can be connected with a given cs line.
3076 Currently Xilinx Zynq qspi supports these type of connections.
3078 - SystemACE Support:
3081 Adding this option adds support for Xilinx SystemACE
3082 chips attached via some sort of local bus. The address
3083 of the chip must also be defined in the
3084 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3086 #define CONFIG_SYSTEMACE
3087 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3089 When SystemACE support is added, the "ace" device type
3090 becomes available to the fat commands, i.e. fatls.
3092 - TFTP Fixed UDP Port:
3095 If this is defined, the environment variable tftpsrcp
3096 is used to supply the TFTP UDP source port value.
3097 If tftpsrcp isn't defined, the normal pseudo-random port
3098 number generator is used.
3100 Also, the environment variable tftpdstp is used to supply
3101 the TFTP UDP destination port value. If tftpdstp isn't
3102 defined, the normal port 69 is used.
3104 The purpose for tftpsrcp is to allow a TFTP server to
3105 blindly start the TFTP transfer using the pre-configured
3106 target IP address and UDP port. This has the effect of
3107 "punching through" the (Windows XP) firewall, allowing
3108 the remainder of the TFTP transfer to proceed normally.
3109 A better solution is to properly configure the firewall,
3110 but sometimes that is not allowed.
3115 This enables a generic 'hash' command which can produce
3116 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3120 Enable the hash verify command (hash -v). This adds to code
3123 CONFIG_SHA1 - This option enables support of hashing using SHA1
3124 algorithm. The hash is calculated in software.
3125 CONFIG_SHA256 - This option enables support of hashing using
3126 SHA256 algorithm. The hash is calculated in software.
3127 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3128 for SHA1/SHA256 hashing.
3129 This affects the 'hash' command and also the
3130 hash_lookup_algo() function.
3131 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3132 hardware-acceleration for SHA1/SHA256 progressive hashing.
3133 Data can be streamed in a block at a time and the hashing
3134 is performed in hardware.
3136 Note: There is also a sha1sum command, which should perhaps
3137 be deprecated in favour of 'hash sha1'.
3139 - Freescale i.MX specific commands:
3140 CONFIG_CMD_HDMIDETECT
3141 This enables 'hdmidet' command which returns true if an
3142 HDMI monitor is detected. This command is i.MX 6 specific.
3145 This enables the 'bmode' (bootmode) command for forcing
3146 a boot from specific media.
3148 This is useful for forcing the ROM's usb downloader to
3149 activate upon a watchdog reset which is nice when iterating
3150 on U-Boot. Using the reset button or running bmode normal
3151 will set it back to normal. This command currently
3152 supports i.MX53 and i.MX6.
3157 This enables the RSA algorithm used for FIT image verification
3158 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3160 The Modular Exponentiation algorithm in RSA is implemented using
3161 driver model. So CONFIG_DM needs to be enabled by default for this
3162 library to function.
3164 The signing part is build into mkimage regardless of this
3165 option. The software based modular exponentiation is built into
3166 mkimage irrespective of this option.
3168 - bootcount support:
3169 CONFIG_BOOTCOUNT_LIMIT
3171 This enables the bootcounter support, see:
3172 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3175 enable special bootcounter support on at91sam9xe based boards.
3177 enable special bootcounter support on blackfin based boards.
3179 enable special bootcounter support on da850 based boards.
3180 CONFIG_BOOTCOUNT_RAM
3181 enable support for the bootcounter in RAM
3182 CONFIG_BOOTCOUNT_I2C
3183 enable support for the bootcounter on an i2c (like RTC) device.
3184 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3185 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3187 CONFIG_BOOTCOUNT_ALEN = address len
3189 - Show boot progress:
3190 CONFIG_SHOW_BOOT_PROGRESS
3192 Defining this option allows to add some board-
3193 specific code (calling a user-provided function
3194 "show_boot_progress(int)") that enables you to show
3195 the system's boot progress on some display (for
3196 example, some LED's) on your board. At the moment,
3197 the following checkpoints are implemented:
3200 Legacy uImage format:
3203 1 common/cmd_bootm.c before attempting to boot an image
3204 -1 common/cmd_bootm.c Image header has bad magic number
3205 2 common/cmd_bootm.c Image header has correct magic number
3206 -2 common/cmd_bootm.c Image header has bad checksum
3207 3 common/cmd_bootm.c Image header has correct checksum
3208 -3 common/cmd_bootm.c Image data has bad checksum
3209 4 common/cmd_bootm.c Image data has correct checksum
3210 -4 common/cmd_bootm.c Image is for unsupported architecture
3211 5 common/cmd_bootm.c Architecture check OK
3212 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3213 6 common/cmd_bootm.c Image Type check OK
3214 -6 common/cmd_bootm.c gunzip uncompression error
3215 -7 common/cmd_bootm.c Unimplemented compression type
3216 7 common/cmd_bootm.c Uncompression OK
3217 8 common/cmd_bootm.c No uncompress/copy overwrite error
3218 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3220 9 common/image.c Start initial ramdisk verification
3221 -10 common/image.c Ramdisk header has bad magic number
3222 -11 common/image.c Ramdisk header has bad checksum
3223 10 common/image.c Ramdisk header is OK
3224 -12 common/image.c Ramdisk data has bad checksum
3225 11 common/image.c Ramdisk data has correct checksum
3226 12 common/image.c Ramdisk verification complete, start loading
3227 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3228 13 common/image.c Start multifile image verification
3229 14 common/image.c No initial ramdisk, no multifile, continue.
3231 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3233 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3234 -31 post/post.c POST test failed, detected by post_output_backlog()
3235 -32 post/post.c POST test failed, detected by post_run_single()
3237 34 common/cmd_doc.c before loading a Image from a DOC device
3238 -35 common/cmd_doc.c Bad usage of "doc" command
3239 35 common/cmd_doc.c correct usage of "doc" command
3240 -36 common/cmd_doc.c No boot device
3241 36 common/cmd_doc.c correct boot device
3242 -37 common/cmd_doc.c Unknown Chip ID on boot device
3243 37 common/cmd_doc.c correct chip ID found, device available
3244 -38 common/cmd_doc.c Read Error on boot device
3245 38 common/cmd_doc.c reading Image header from DOC device OK
3246 -39 common/cmd_doc.c Image header has bad magic number
3247 39 common/cmd_doc.c Image header has correct magic number
3248 -40 common/cmd_doc.c Error reading Image from DOC device
3249 40 common/cmd_doc.c Image header has correct magic number
3250 41 common/cmd_ide.c before loading a Image from a IDE device
3251 -42 common/cmd_ide.c Bad usage of "ide" command
3252 42 common/cmd_ide.c correct usage of "ide" command
3253 -43 common/cmd_ide.c No boot device
3254 43 common/cmd_ide.c boot device found
3255 -44 common/cmd_ide.c Device not available
3256 44 common/cmd_ide.c Device available
3257 -45 common/cmd_ide.c wrong partition selected
3258 45 common/cmd_ide.c partition selected
3259 -46 common/cmd_ide.c Unknown partition table
3260 46 common/cmd_ide.c valid partition table found
3261 -47 common/cmd_ide.c Invalid partition type
3262 47 common/cmd_ide.c correct partition type
3263 -48 common/cmd_ide.c Error reading Image Header on boot device
3264 48 common/cmd_ide.c reading Image Header from IDE device OK
3265 -49 common/cmd_ide.c Image header has bad magic number
3266 49 common/cmd_ide.c Image header has correct magic number
3267 -50 common/cmd_ide.c Image header has bad checksum
3268 50 common/cmd_ide.c Image header has correct checksum
3269 -51 common/cmd_ide.c Error reading Image from IDE device
3270 51 common/cmd_ide.c reading Image from IDE device OK
3271 52 common/cmd_nand.c before loading a Image from a NAND device
3272 -53 common/cmd_nand.c Bad usage of "nand" command
3273 53 common/cmd_nand.c correct usage of "nand" command
3274 -54 common/cmd_nand.c No boot device
3275 54 common/cmd_nand.c boot device found
3276 -55 common/cmd_nand.c Unknown Chip ID on boot device
3277 55 common/cmd_nand.c correct chip ID found, device available
3278 -56 common/cmd_nand.c Error reading Image Header on boot device
3279 56 common/cmd_nand.c reading Image Header from NAND device OK
3280 -57 common/cmd_nand.c Image header has bad magic number
3281 57 common/cmd_nand.c Image header has correct magic number
3282 -58 common/cmd_nand.c Error reading Image from NAND device
3283 58 common/cmd_nand.c reading Image from NAND device OK
3285 -60 common/env_common.c Environment has a bad CRC, using default
3287 64 net/eth.c starting with Ethernet configuration.
3288 -64 net/eth.c no Ethernet found.
3289 65 net/eth.c Ethernet found.
3291 -80 common/cmd_net.c usage wrong
3292 80 common/cmd_net.c before calling net_loop()
3293 -81 common/cmd_net.c some error in net_loop() occurred
3294 81 common/cmd_net.c net_loop() back without error
3295 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3296 82 common/cmd_net.c trying automatic boot
3297 83 common/cmd_net.c running "source" command
3298 -83 common/cmd_net.c some error in automatic boot or "source" command
3299 84 common/cmd_net.c end without errors
3304 100 common/cmd_bootm.c Kernel FIT Image has correct format
3305 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3306 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3307 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3308 102 common/cmd_bootm.c Kernel unit name specified
3309 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3310 103 common/cmd_bootm.c Found configuration node
3311 104 common/cmd_bootm.c Got kernel subimage node offset
3312 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3313 105 common/cmd_bootm.c Kernel subimage hash verification OK
3314 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3315 106 common/cmd_bootm.c Architecture check OK
3316 -106 common/cmd_bootm.c Kernel subimage has wrong type
3317 107 common/cmd_bootm.c Kernel subimage type OK
3318 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3319 108 common/cmd_bootm.c Got kernel subimage data/size
3320 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3321 -109 common/cmd_bootm.c Can't get kernel subimage type
3322 -110 common/cmd_bootm.c Can't get kernel subimage comp
3323 -111 common/cmd_bootm.c Can't get kernel subimage os
3324 -112 common/cmd_bootm.c Can't get kernel subimage load address
3325 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3327 120 common/image.c Start initial ramdisk verification
3328 -120 common/image.c Ramdisk FIT image has incorrect format
3329 121 common/image.c Ramdisk FIT image has correct format
3330 122 common/image.c No ramdisk subimage unit name, using configuration
3331 -122 common/image.c Can't get configuration for ramdisk subimage
3332 123 common/image.c Ramdisk unit name specified
3333 -124 common/image.c Can't get ramdisk subimage node offset
3334 125 common/image.c Got ramdisk subimage node offset
3335 -125 common/image.c Ramdisk subimage hash verification failed
3336 126 common/image.c Ramdisk subimage hash verification OK
3337 -126 common/image.c Ramdisk subimage for unsupported architecture
3338 127 common/image.c Architecture check OK
3339 -127 common/image.c Can't get ramdisk subimage data/size
3340 128 common/image.c Got ramdisk subimage data/size
3341 129 common/image.c Can't get ramdisk load address
3342 -129 common/image.c Got ramdisk load address
3344 -130 common/cmd_doc.c Incorrect FIT image format
3345 131 common/cmd_doc.c FIT image format OK
3347 -140 common/cmd_ide.c Incorrect FIT image format
3348 141 common/cmd_ide.c FIT image format OK
3350 -150 common/cmd_nand.c Incorrect FIT image format
3351 151 common/cmd_nand.c FIT image format OK
3353 - legacy image format:
3354 CONFIG_IMAGE_FORMAT_LEGACY
3355 enables the legacy image format support in U-Boot.
3358 enabled if CONFIG_FIT_SIGNATURE is not defined.
3360 CONFIG_DISABLE_IMAGE_LEGACY
3361 disable the legacy image format
3363 This define is introduced, as the legacy image format is
3364 enabled per default for backward compatibility.
3366 - FIT image support:
3368 Enable support for the FIT uImage format.
3370 CONFIG_FIT_BEST_MATCH
3371 When no configuration is explicitly selected, default to the
3372 one whose fdt's compatibility field best matches that of
3373 U-Boot itself. A match is considered "best" if it matches the
3374 most specific compatibility entry of U-Boot's fdt's root node.
3375 The order of entries in the configuration's fdt is ignored.
3377 CONFIG_FIT_SIGNATURE
3378 This option enables signature verification of FIT uImages,
3379 using a hash signed and verified using RSA. If
3380 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3381 hashing is available using hardware, RSA library will use it.
3382 See doc/uImage.FIT/signature.txt for more details.
3384 WARNING: When relying on signed FIT images with required
3385 signature check the legacy image format is default
3386 disabled. If a board need legacy image format support
3387 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3389 CONFIG_FIT_DISABLE_SHA256
3390 Supporting SHA256 hashes has quite an impact on binary size.
3391 For constrained systems sha256 hash support can be disabled
3394 - Standalone program support:
3395 CONFIG_STANDALONE_LOAD_ADDR
3397 This option defines a board specific value for the
3398 address where standalone program gets loaded, thus
3399 overwriting the architecture dependent default
3402 - Frame Buffer Address:
3405 Define CONFIG_FB_ADDR if you want to use specific
3406 address for frame buffer. This is typically the case
3407 when using a graphics controller has separate video
3408 memory. U-Boot will then place the frame buffer at
3409 the given address instead of dynamically reserving it
3410 in system RAM by calling lcd_setmem(), which grabs
3411 the memory for the frame buffer depending on the
3412 configured panel size.
3414 Please see board_init_f function.
3416 - Automatic software updates via TFTP server
3418 CONFIG_UPDATE_TFTP_CNT_MAX
3419 CONFIG_UPDATE_TFTP_MSEC_MAX
3421 These options enable and control the auto-update feature;
3422 for a more detailed description refer to doc/README.update.
3424 - MTD Support (mtdparts command, UBI support)
3427 Adds the MTD device infrastructure from the Linux kernel.
3428 Needed for mtdparts command support.
3430 CONFIG_MTD_PARTITIONS
3432 Adds the MTD partitioning infrastructure from the Linux
3433 kernel. Needed for UBI support.
3438 Adds commands for interacting with MTD partitions formatted
3439 with the UBI flash translation layer
3441 Requires also defining CONFIG_RBTREE
3443 CONFIG_UBI_SILENCE_MSG
3445 Make the verbose messages from UBI stop printing. This leaves
3446 warnings and errors enabled.
3449 CONFIG_MTD_UBI_WL_THRESHOLD
3450 This parameter defines the maximum difference between the highest
3451 erase counter value and the lowest erase counter value of eraseblocks
3452 of UBI devices. When this threshold is exceeded, UBI starts performing
3453 wear leveling by means of moving data from eraseblock with low erase
3454 counter to eraseblocks with high erase counter.
3456 The default value should be OK for SLC NAND flashes, NOR flashes and
3457 other flashes which have eraseblock life-cycle 100000 or more.
3458 However, in case of MLC NAND flashes which typically have eraseblock
3459 life-cycle less than 10000, the threshold should be lessened (e.g.,
3460 to 128 or 256, although it does not have to be power of 2).
3464 CONFIG_MTD_UBI_BEB_LIMIT
3465 This option specifies the maximum bad physical eraseblocks UBI
3466 expects on the MTD device (per 1024 eraseblocks). If the
3467 underlying flash does not admit of bad eraseblocks (e.g. NOR
3468 flash), this value is ignored.
3470 NAND datasheets often specify the minimum and maximum NVM
3471 (Number of Valid Blocks) for the flashes' endurance lifetime.
3472 The maximum expected bad eraseblocks per 1024 eraseblocks
3473 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3474 which gives 20 for most NANDs (MaxNVB is basically the total
3475 count of eraseblocks on the chip).
3477 To put it differently, if this value is 20, UBI will try to
3478 reserve about 1.9% of physical eraseblocks for bad blocks
3479 handling. And that will be 1.9% of eraseblocks on the entire
3480 NAND chip, not just the MTD partition UBI attaches. This means
3481 that if you have, say, a NAND flash chip admits maximum 40 bad
3482 eraseblocks, and it is split on two MTD partitions of the same
3483 size, UBI will reserve 40 eraseblocks when attaching a
3488 CONFIG_MTD_UBI_FASTMAP
3489 Fastmap is a mechanism which allows attaching an UBI device
3490 in nearly constant time. Instead of scanning the whole MTD device it
3491 only has to locate a checkpoint (called fastmap) on the device.
3492 The on-flash fastmap contains all information needed to attach
3493 the device. Using fastmap makes only sense on large devices where
3494 attaching by scanning takes long. UBI will not automatically install
3495 a fastmap on old images, but you can set the UBI parameter
3496 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3497 that fastmap-enabled images are still usable with UBI implementations
3498 without fastmap support. On typical flash devices the whole fastmap
3499 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3501 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3502 Set this parameter to enable fastmap automatically on images
3506 CONFIG_MTD_UBI_FM_DEBUG
3507 Enable UBI fastmap debug
3513 Adds commands for interacting with UBI volumes formatted as
3514 UBIFS. UBIFS is read-only in u-boot.
3516 Requires UBI support as well as CONFIG_LZO
3518 CONFIG_UBIFS_SILENCE_MSG
3520 Make the verbose messages from UBIFS stop printing. This leaves
3521 warnings and errors enabled.
3525 Enable building of SPL globally.
3528 LDSCRIPT for linking the SPL binary.
3530 CONFIG_SPL_MAX_FOOTPRINT
3531 Maximum size in memory allocated to the SPL, BSS included.
3532 When defined, the linker checks that the actual memory
3533 used by SPL from _start to __bss_end does not exceed it.
3534 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3535 must not be both defined at the same time.
3538 Maximum size of the SPL image (text, data, rodata, and
3539 linker lists sections), BSS excluded.
3540 When defined, the linker checks that the actual size does
3543 CONFIG_SPL_TEXT_BASE
3544 TEXT_BASE for linking the SPL binary.
3546 CONFIG_SPL_RELOC_TEXT_BASE
3547 Address to relocate to. If unspecified, this is equal to
3548 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3550 CONFIG_SPL_BSS_START_ADDR
3551 Link address for the BSS within the SPL binary.
3553 CONFIG_SPL_BSS_MAX_SIZE
3554 Maximum size in memory allocated to the SPL BSS.
3555 When defined, the linker checks that the actual memory used
3556 by SPL from __bss_start to __bss_end does not exceed it.
3557 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3558 must not be both defined at the same time.
3561 Adress of the start of the stack SPL will use
3563 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3564 When defined, SPL will panic() if the image it has
3565 loaded does not have a signature.
3566 Defining this is useful when code which loads images
3567 in SPL cannot guarantee that absolutely all read errors
3569 An example is the LPC32XX MLC NAND driver, which will
3570 consider that a completely unreadable NAND block is bad,
3571 and thus should be skipped silently.
3573 CONFIG_SPL_RELOC_STACK
3574 Adress of the start of the stack SPL will use after
3575 relocation. If unspecified, this is equal to
3578 CONFIG_SYS_SPL_MALLOC_START
3579 Starting address of the malloc pool used in SPL.
3581 CONFIG_SYS_SPL_MALLOC_SIZE
3582 The size of the malloc pool used in SPL.
3584 CONFIG_SPL_FRAMEWORK
3585 Enable the SPL framework under common/. This framework
3586 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3587 NAND loading of the Linux Kernel.
3590 Enable booting directly to an OS from SPL.
3591 See also: doc/README.falcon
3593 CONFIG_SPL_DISPLAY_PRINT
3594 For ARM, enable an optional function to print more information
3595 about the running system.
3597 CONFIG_SPL_INIT_MINIMAL
3598 Arch init code should be built for a very small image
3600 CONFIG_SPL_LIBCOMMON_SUPPORT
3601 Support for common/libcommon.o in SPL binary
3603 CONFIG_SPL_LIBDISK_SUPPORT
3604 Support for disk/libdisk.o in SPL binary
3606 CONFIG_SPL_I2C_SUPPORT
3607 Support for drivers/i2c/libi2c.o in SPL binary
3609 CONFIG_SPL_GPIO_SUPPORT
3610 Support for drivers/gpio/libgpio.o in SPL binary
3612 CONFIG_SPL_MMC_SUPPORT
3613 Support for drivers/mmc/libmmc.o in SPL binary
3615 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3616 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3617 Address and partition on the MMC to load U-Boot from
3618 when the MMC is being used in raw mode.
3620 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3621 Partition on the MMC to load U-Boot from when the MMC is being
3624 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3625 Sector to load kernel uImage from when MMC is being
3626 used in raw mode (for Falcon mode)
3628 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3629 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3630 Sector and number of sectors to load kernel argument
3631 parameters from when MMC is being used in raw mode
3634 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3635 Partition on the MMC to load U-Boot from when the MMC is being
3638 CONFIG_SPL_FAT_SUPPORT
3639 Support for fs/fat/libfat.o in SPL binary
3641 CONFIG_SPL_EXT_SUPPORT
3642 Support for EXT filesystem in SPL binary
3644 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3645 Filename to read to load U-Boot when reading from filesystem
3647 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3648 Filename to read to load kernel uImage when reading
3649 from filesystem (for Falcon mode)
3651 CONFIG_SPL_FS_LOAD_ARGS_NAME
3652 Filename to read to load kernel argument parameters
3653 when reading from filesystem (for Falcon mode)
3655 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3656 Set this for NAND SPL on PPC mpc83xx targets, so that
3657 start.S waits for the rest of the SPL to load before
3658 continuing (the hardware starts execution after just
3659 loading the first page rather than the full 4K).
3661 CONFIG_SPL_SKIP_RELOCATE
3662 Avoid SPL relocation
3664 CONFIG_SPL_NAND_BASE
3665 Include nand_base.c in the SPL. Requires
3666 CONFIG_SPL_NAND_DRIVERS.
3668 CONFIG_SPL_NAND_DRIVERS
3669 SPL uses normal NAND drivers, not minimal drivers.
3672 Include standard software ECC in the SPL
3674 CONFIG_SPL_NAND_SIMPLE
3675 Support for NAND boot using simple NAND drivers that
3676 expose the cmd_ctrl() interface.
3678 CONFIG_SPL_MTD_SUPPORT
3679 Support for the MTD subsystem within SPL. Useful for
3680 environment on NAND support within SPL.
3682 CONFIG_SPL_NAND_RAW_ONLY
3683 Support to boot only raw u-boot.bin images. Use this only
3684 if you need to save space.
3686 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3687 Set for the SPL on PPC mpc8xxx targets, support for
3688 drivers/ddr/fsl/libddr.o in SPL binary.
3690 CONFIG_SPL_COMMON_INIT_DDR
3691 Set for common ddr init with serial presence detect in
3694 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3695 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3696 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3697 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3698 CONFIG_SYS_NAND_ECCBYTES
3699 Defines the size and behavior of the NAND that SPL uses
3702 CONFIG_SPL_NAND_BOOT
3703 Add support NAND boot
3705 CONFIG_SYS_NAND_U_BOOT_OFFS
3706 Location in NAND to read U-Boot from
3708 CONFIG_SYS_NAND_U_BOOT_DST
3709 Location in memory to load U-Boot to
3711 CONFIG_SYS_NAND_U_BOOT_SIZE
3712 Size of image to load
3714 CONFIG_SYS_NAND_U_BOOT_START
3715 Entry point in loaded image to jump to
3717 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3718 Define this if you need to first read the OOB and then the
3719 data. This is used, for example, on davinci platforms.
3721 CONFIG_SPL_OMAP3_ID_NAND
3722 Support for an OMAP3-specific set of functions to return the
3723 ID and MFR of the first attached NAND chip, if present.
3725 CONFIG_SPL_SERIAL_SUPPORT
3726 Support for drivers/serial/libserial.o in SPL binary
3728 CONFIG_SPL_SPI_FLASH_SUPPORT
3729 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3731 CONFIG_SPL_SPI_SUPPORT
3732 Support for drivers/spi/libspi.o in SPL binary
3734 CONFIG_SPL_RAM_DEVICE
3735 Support for running image already present in ram, in SPL binary
3737 CONFIG_SPL_LIBGENERIC_SUPPORT
3738 Support for lib/libgeneric.o in SPL binary
3740 CONFIG_SPL_ENV_SUPPORT
3741 Support for the environment operating in SPL binary
3743 CONFIG_SPL_NET_SUPPORT
3744 Support for the net/libnet.o in SPL binary.
3745 It conflicts with SPL env from storage medium specified by
3746 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3749 Image offset to which the SPL should be padded before appending
3750 the SPL payload. By default, this is defined as
3751 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3752 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3753 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3756 Final target image containing SPL and payload. Some SPLs
3757 use an arch-specific makefile fragment instead, for
3758 example if more than one image needs to be produced.
3760 CONFIG_FIT_SPL_PRINT
3761 Printing information about a FIT image adds quite a bit of
3762 code to SPL. So this is normally disabled in SPL. Use this
3763 option to re-enable it. This will affect the output of the
3764 bootm command when booting a FIT image.
3768 Enable building of TPL globally.
3771 Image offset to which the TPL should be padded before appending
3772 the TPL payload. By default, this is defined as
3773 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3774 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3775 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3780 [so far only for SMDK2400 boards]
3782 - Modem support enable:
3783 CONFIG_MODEM_SUPPORT
3785 - RTS/CTS Flow control enable:
3788 - Modem debug support:
3789 CONFIG_MODEM_SUPPORT_DEBUG
3791 Enables debugging stuff (char screen[1024], dbg())
3792 for modem support. Useful only with BDI2000.
3794 - Interrupt support (PPC):
3796 There are common interrupt_init() and timer_interrupt()
3797 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3798 for CPU specific initialization. interrupt_init_cpu()
3799 should set decrementer_count to appropriate value. If
3800 CPU resets decrementer automatically after interrupt
3801 (ppc4xx) it should set decrementer_count to zero.
3802 timer_interrupt() calls timer_interrupt_cpu() for CPU
3803 specific handling. If board has watchdog / status_led
3804 / other_activity_monitor it works automatically from
3805 general timer_interrupt().
3809 In the target system modem support is enabled when a
3810 specific key (key combination) is pressed during
3811 power-on. Otherwise U-Boot will boot normally
3812 (autoboot). The key_pressed() function is called from
3813 board_init(). Currently key_pressed() is a dummy
3814 function, returning 1 and thus enabling modem
3817 If there are no modem init strings in the
3818 environment, U-Boot proceed to autoboot; the
3819 previous output (banner, info printfs) will be
3822 See also: doc/README.Modem
3824 Board initialization settings:
3825 ------------------------------
3827 During Initialization u-boot calls a number of board specific functions
3828 to allow the preparation of board specific prerequisites, e.g. pin setup
3829 before drivers are initialized. To enable these callbacks the
3830 following configuration macros have to be defined. Currently this is
3831 architecture specific, so please check arch/your_architecture/lib/board.c
3832 typically in board_init_f() and board_init_r().
3834 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3835 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3836 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3837 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3839 Configuration Settings:
3840 -----------------------
3842 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3843 Optionally it can be defined to support 64-bit memory commands.
3845 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3846 undefine this when you're short of memory.
3848 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3849 width of the commands listed in the 'help' command output.
3851 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3852 prompt for user input.
3854 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3856 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3858 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3860 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3861 the application (usually a Linux kernel) when it is
3864 - CONFIG_SYS_BAUDRATE_TABLE:
3865 List of legal baudrate settings for this board.
3867 - CONFIG_SYS_CONSOLE_INFO_QUIET
3868 Suppress display of console information at boot.
3870 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3871 If the board specific function
3872 extern int overwrite_console (void);
3873 returns 1, the stdin, stderr and stdout are switched to the
3874 serial port, else the settings in the environment are used.
3876 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3877 Enable the call to overwrite_console().
3879 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3880 Enable overwrite of previous console environment settings.
3882 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3883 Begin and End addresses of the area used by the
3886 - CONFIG_SYS_ALT_MEMTEST:
3887 Enable an alternate, more extensive memory test.
3889 - CONFIG_SYS_MEMTEST_SCRATCH:
3890 Scratch address used by the alternate memory test
3891 You only need to set this if address zero isn't writeable
3893 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3894 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3895 this specified memory area will get subtracted from the top
3896 (end) of RAM and won't get "touched" at all by U-Boot. By
3897 fixing up gd->ram_size the Linux kernel should gets passed
3898 the now "corrected" memory size and won't touch it either.
3899 This should work for arch/ppc and arch/powerpc. Only Linux
3900 board ports in arch/powerpc with bootwrapper support that
3901 recalculate the memory size from the SDRAM controller setup
3902 will have to get fixed in Linux additionally.
3904 This option can be used as a workaround for the 440EPx/GRx
3905 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3908 WARNING: Please make sure that this value is a multiple of
3909 the Linux page size (normally 4k). If this is not the case,
3910 then the end address of the Linux memory will be located at a
3911 non page size aligned address and this could cause major
3914 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3915 Enable temporary baudrate change while serial download
3917 - CONFIG_SYS_SDRAM_BASE:
3918 Physical start address of SDRAM. _Must_ be 0 here.
3920 - CONFIG_SYS_MBIO_BASE:
3921 Physical start address of Motherboard I/O (if using a
3924 - CONFIG_SYS_FLASH_BASE:
3925 Physical start address of Flash memory.
3927 - CONFIG_SYS_MONITOR_BASE:
3928 Physical start address of boot monitor code (set by
3929 make config files to be same as the text base address
3930 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3931 CONFIG_SYS_FLASH_BASE when booting from flash.
3933 - CONFIG_SYS_MONITOR_LEN:
3934 Size of memory reserved for monitor code, used to
3935 determine _at_compile_time_ (!) if the environment is
3936 embedded within the U-Boot image, or in a separate
3939 - CONFIG_SYS_MALLOC_LEN:
3940 Size of DRAM reserved for malloc() use.
3942 - CONFIG_SYS_MALLOC_F_LEN
3943 Size of the malloc() pool for use before relocation. If
3944 this is defined, then a very simple malloc() implementation
3945 will become available before relocation. The address is just
3946 below the global data, and the stack is moved down to make
3949 This feature allocates regions with increasing addresses
3950 within the region. calloc() is supported, but realloc()
3951 is not available. free() is supported but does nothing.
3952 The memory will be freed (or in fact just forgotten) when
3953 U-Boot relocates itself.
3955 Pre-relocation malloc() is only supported on ARM and sandbox
3956 at present but is fairly easy to enable for other archs.
3958 - CONFIG_SYS_MALLOC_SIMPLE
3959 Provides a simple and small malloc() and calloc() for those
3960 boards which do not use the full malloc in SPL (which is
3961 enabled with CONFIG_SYS_SPL_MALLOC_START).
3963 - CONFIG_SYS_NONCACHED_MEMORY:
3964 Size of non-cached memory area. This area of memory will be
3965 typically located right below the malloc() area and mapped
3966 uncached in the MMU. This is useful for drivers that would
3967 otherwise require a lot of explicit cache maintenance. For
3968 some drivers it's also impossible to properly maintain the
3969 cache. For example if the regions that need to be flushed
3970 are not a multiple of the cache-line size, *and* padding
3971 cannot be allocated between the regions to align them (i.e.
3972 if the HW requires a contiguous array of regions, and the
3973 size of each region is not cache-aligned), then a flush of
3974 one region may result in overwriting data that hardware has
3975 written to another region in the same cache-line. This can
3976 happen for example in network drivers where descriptors for
3977 buffers are typically smaller than the CPU cache-line (e.g.
3978 16 bytes vs. 32 or 64 bytes).
3980 Non-cached memory is only supported on 32-bit ARM at present.
3982 - CONFIG_SYS_BOOTM_LEN:
3983 Normally compressed uImages are limited to an
3984 uncompressed size of 8 MBytes. If this is not enough,
3985 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3986 to adjust this setting to your needs.
3988 - CONFIG_SYS_BOOTMAPSZ:
3989 Maximum size of memory mapped by the startup code of
3990 the Linux kernel; all data that must be processed by
3991 the Linux kernel (bd_info, boot arguments, FDT blob if
3992 used) must be put below this limit, unless "bootm_low"
3993 environment variable is defined and non-zero. In such case
3994 all data for the Linux kernel must be between "bootm_low"
3995 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3996 variable "bootm_mapsize" will override the value of
3997 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3998 then the value in "bootm_size" will be used instead.
4000 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4001 Enable initrd_high functionality. If defined then the
4002 initrd_high feature is enabled and the bootm ramdisk subcommand
4005 - CONFIG_SYS_BOOT_GET_CMDLINE:
4006 Enables allocating and saving kernel cmdline in space between
4007 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4009 - CONFIG_SYS_BOOT_GET_KBD:
4010 Enables allocating and saving a kernel copy of the bd_info in
4011 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4013 - CONFIG_SYS_MAX_FLASH_BANKS:
4014 Max number of Flash memory banks
4016 - CONFIG_SYS_MAX_FLASH_SECT:
4017 Max number of sectors on a Flash chip
4019 - CONFIG_SYS_FLASH_ERASE_TOUT:
4020 Timeout for Flash erase operations (in ms)
4022 - CONFIG_SYS_FLASH_WRITE_TOUT:
4023 Timeout for Flash write operations (in ms)
4025 - CONFIG_SYS_FLASH_LOCK_TOUT
4026 Timeout for Flash set sector lock bit operation (in ms)
4028 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4029 Timeout for Flash clear lock bits operation (in ms)
4031 - CONFIG_SYS_FLASH_PROTECTION
4032 If defined, hardware flash sectors protection is used
4033 instead of U-Boot software protection.
4035 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4037 Enable TFTP transfers directly to flash memory;
4038 without this option such a download has to be
4039 performed in two steps: (1) download to RAM, and (2)
4040 copy from RAM to flash.
4042 The two-step approach is usually more reliable, since
4043 you can check if the download worked before you erase
4044 the flash, but in some situations (when system RAM is
4045 too limited to allow for a temporary copy of the
4046 downloaded image) this option may be very useful.
4048 - CONFIG_SYS_FLASH_CFI:
4049 Define if the flash driver uses extra elements in the
4050 common flash structure for storing flash geometry.
4052 - CONFIG_FLASH_CFI_DRIVER
4053 This option also enables the building of the cfi_flash driver
4054 in the drivers directory
4056 - CONFIG_FLASH_CFI_MTD
4057 This option enables the building of the cfi_mtd driver
4058 in the drivers directory. The driver exports CFI flash
4061 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4062 Use buffered writes to flash.
4064 - CONFIG_FLASH_SPANSION_S29WS_N
4065 s29ws-n MirrorBit flash has non-standard addresses for buffered
4068 - CONFIG_SYS_FLASH_QUIET_TEST
4069 If this option is defined, the common CFI flash doesn't
4070 print it's warning upon not recognized FLASH banks. This
4071 is useful, if some of the configured banks are only
4072 optionally available.
4074 - CONFIG_FLASH_SHOW_PROGRESS
4075 If defined (must be an integer), print out countdown
4076 digits and dots. Recommended value: 45 (9..1) for 80
4077 column displays, 15 (3..1) for 40 column displays.
4079 - CONFIG_FLASH_VERIFY
4080 If defined, the content of the flash (destination) is compared
4081 against the source after the write operation. An error message
4082 will be printed when the contents are not identical.
4083 Please note that this option is useless in nearly all cases,
4084 since such flash programming errors usually are detected earlier
4085 while unprotecting/erasing/programming. Please only enable
4086 this option if you really know what you are doing.
4088 - CONFIG_SYS_RX_ETH_BUFFER:
4089 Defines the number of Ethernet receive buffers. On some
4090 Ethernet controllers it is recommended to set this value
4091 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4092 buffers can be full shortly after enabling the interface
4093 on high Ethernet traffic.
4094 Defaults to 4 if not defined.
4096 - CONFIG_ENV_MAX_ENTRIES
4098 Maximum number of entries in the hash table that is used
4099 internally to store the environment settings. The default
4100 setting is supposed to be generous and should work in most
4101 cases. This setting can be used to tune behaviour; see
4102 lib/hashtable.c for details.
4104 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4105 - CONFIG_ENV_FLAGS_LIST_STATIC
4106 Enable validation of the values given to environment variables when
4107 calling env set. Variables can be restricted to only decimal,
4108 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4109 the variables can also be restricted to IP address or MAC address.
4111 The format of the list is:
4112 type_attribute = [s|d|x|b|i|m]
4113 access_attribute = [a|r|o|c]
4114 attributes = type_attribute[access_attribute]
4115 entry = variable_name[:attributes]
4118 The type attributes are:
4119 s - String (default)
4122 b - Boolean ([1yYtT|0nNfF])
4126 The access attributes are:
4132 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4133 Define this to a list (string) to define the ".flags"
4134 environment variable in the default or embedded environment.
4136 - CONFIG_ENV_FLAGS_LIST_STATIC
4137 Define this to a list (string) to define validation that
4138 should be done if an entry is not found in the ".flags"
4139 environment variable. To override a setting in the static
4140 list, simply add an entry for the same variable name to the
4143 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4144 regular expression. This allows multiple variables to define the same
4145 flags without explicitly listing them for each variable.
4147 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4148 If defined, don't allow the -f switch to env set override variable
4151 - CONFIG_SYS_GENERIC_BOARD
4152 This selects the architecture-generic board system instead of the
4153 architecture-specific board files. It is intended to move boards
4154 to this new framework over time. Defining this will disable the
4155 arch/foo/lib/board.c file and use common/board_f.c and
4156 common/board_r.c instead. To use this option your architecture
4157 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4158 If you find problems enabling this option on your board please report
4159 the problem and send patches!
4161 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4162 This is set by OMAP boards for the max time that reset should
4163 be asserted. See doc/README.omap-reset-time for details on how
4164 the value can be calculated on a given board.
4167 If stdint.h is available with your toolchain you can define this
4168 option to enable it. You can provide option 'USE_STDINT=1' when
4169 building U-Boot to enable this.
4171 The following definitions that deal with the placement and management
4172 of environment data (variable area); in general, we support the
4173 following configurations:
4175 - CONFIG_BUILD_ENVCRC:
4177 Builds up envcrc with the target environment so that external utils
4178 may easily extract it and embed it in final U-Boot images.
4180 - CONFIG_ENV_IS_IN_FLASH:
4182 Define this if the environment is in flash memory.
4184 a) The environment occupies one whole flash sector, which is
4185 "embedded" in the text segment with the U-Boot code. This
4186 happens usually with "bottom boot sector" or "top boot
4187 sector" type flash chips, which have several smaller
4188 sectors at the start or the end. For instance, such a
4189 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4190 such a case you would place the environment in one of the
4191 4 kB sectors - with U-Boot code before and after it. With
4192 "top boot sector" type flash chips, you would put the
4193 environment in one of the last sectors, leaving a gap
4194 between U-Boot and the environment.
4196 - CONFIG_ENV_OFFSET:
4198 Offset of environment data (variable area) to the
4199 beginning of flash memory; for instance, with bottom boot
4200 type flash chips the second sector can be used: the offset
4201 for this sector is given here.
4203 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4207 This is just another way to specify the start address of
4208 the flash sector containing the environment (instead of
4211 - CONFIG_ENV_SECT_SIZE:
4213 Size of the sector containing the environment.
4216 b) Sometimes flash chips have few, equal sized, BIG sectors.
4217 In such a case you don't want to spend a whole sector for
4222 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4223 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4224 of this flash sector for the environment. This saves
4225 memory for the RAM copy of the environment.
4227 It may also save flash memory if you decide to use this
4228 when your environment is "embedded" within U-Boot code,
4229 since then the remainder of the flash sector could be used
4230 for U-Boot code. It should be pointed out that this is
4231 STRONGLY DISCOURAGED from a robustness point of view:
4232 updating the environment in flash makes it always
4233 necessary to erase the WHOLE sector. If something goes
4234 wrong before the contents has been restored from a copy in
4235 RAM, your target system will be dead.
4237 - CONFIG_ENV_ADDR_REDUND
4238 CONFIG_ENV_SIZE_REDUND
4240 These settings describe a second storage area used to hold
4241 a redundant copy of the environment data, so that there is
4242 a valid backup copy in case there is a power failure during
4243 a "saveenv" operation.
4245 BE CAREFUL! Any changes to the flash layout, and some changes to the
4246 source code will make it necessary to adapt <board>/u-boot.lds*
4250 - CONFIG_ENV_IS_IN_NVRAM:
4252 Define this if you have some non-volatile memory device
4253 (NVRAM, battery buffered SRAM) which you want to use for the
4259 These two #defines are used to determine the memory area you
4260 want to use for environment. It is assumed that this memory
4261 can just be read and written to, without any special
4264 BE CAREFUL! The first access to the environment happens quite early
4265 in U-Boot initialization (when we try to get the setting of for the
4266 console baudrate). You *MUST* have mapped your NVRAM area then, or
4269 Please note that even with NVRAM we still use a copy of the
4270 environment in RAM: we could work on NVRAM directly, but we want to
4271 keep settings there always unmodified except somebody uses "saveenv"
4272 to save the current settings.
4275 - CONFIG_ENV_IS_IN_EEPROM:
4277 Use this if you have an EEPROM or similar serial access
4278 device and a driver for it.
4280 - CONFIG_ENV_OFFSET:
4283 These two #defines specify the offset and size of the
4284 environment area within the total memory of your EEPROM.
4286 - CONFIG_SYS_I2C_EEPROM_ADDR:
4287 If defined, specified the chip address of the EEPROM device.
4288 The default address is zero.
4290 - CONFIG_SYS_I2C_EEPROM_BUS:
4291 If defined, specified the i2c bus of the EEPROM device.
4293 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4294 If defined, the number of bits used to address bytes in a
4295 single page in the EEPROM device. A 64 byte page, for example
4296 would require six bits.
4298 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4299 If defined, the number of milliseconds to delay between
4300 page writes. The default is zero milliseconds.
4302 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4303 The length in bytes of the EEPROM memory array address. Note
4304 that this is NOT the chip address length!
4306 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4307 EEPROM chips that implement "address overflow" are ones
4308 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4309 address and the extra bits end up in the "chip address" bit
4310 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4313 Note that we consider the length of the address field to
4314 still be one byte because the extra address bits are hidden
4315 in the chip address.
4317 - CONFIG_SYS_EEPROM_SIZE:
4318 The size in bytes of the EEPROM device.
4320 - CONFIG_ENV_EEPROM_IS_ON_I2C
4321 define this, if you have I2C and SPI activated, and your
4322 EEPROM, which holds the environment, is on the I2C bus.
4324 - CONFIG_I2C_ENV_EEPROM_BUS
4325 if you have an Environment on an EEPROM reached over
4326 I2C muxes, you can define here, how to reach this
4327 EEPROM. For example:
4329 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4331 EEPROM which holds the environment, is reached over
4332 a pca9547 i2c mux with address 0x70, channel 3.
4334 - CONFIG_ENV_IS_IN_DATAFLASH:
4336 Define this if you have a DataFlash memory device which you
4337 want to use for the environment.
4339 - CONFIG_ENV_OFFSET:
4343 These three #defines specify the offset and size of the
4344 environment area within the total memory of your DataFlash placed
4345 at the specified address.
4347 - CONFIG_ENV_IS_IN_SPI_FLASH:
4349 Define this if you have a SPI Flash memory device which you
4350 want to use for the environment.
4352 - CONFIG_ENV_OFFSET:
4355 These two #defines specify the offset and size of the
4356 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4357 aligned to an erase sector boundary.
4359 - CONFIG_ENV_SECT_SIZE:
4361 Define the SPI flash's sector size.
4363 - CONFIG_ENV_OFFSET_REDUND (optional):
4365 This setting describes a second storage area of CONFIG_ENV_SIZE
4366 size used to hold a redundant copy of the environment data, so
4367 that there is a valid backup copy in case there is a power failure
4368 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4369 aligned to an erase sector boundary.
4371 - CONFIG_ENV_SPI_BUS (optional):
4372 - CONFIG_ENV_SPI_CS (optional):
4374 Define the SPI bus and chip select. If not defined they will be 0.
4376 - CONFIG_ENV_SPI_MAX_HZ (optional):
4378 Define the SPI max work clock. If not defined then use 1MHz.
4380 - CONFIG_ENV_SPI_MODE (optional):
4382 Define the SPI work mode. If not defined then use SPI_MODE_3.
4384 - CONFIG_ENV_IS_IN_REMOTE:
4386 Define this if you have a remote memory space which you
4387 want to use for the local device's environment.
4392 These two #defines specify the address and size of the
4393 environment area within the remote memory space. The
4394 local device can get the environment from remote memory
4395 space by SRIO or PCIE links.
4397 BE CAREFUL! For some special cases, the local device can not use
4398 "saveenv" command. For example, the local device will get the
4399 environment stored in a remote NOR flash by SRIO or PCIE link,
4400 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4402 - CONFIG_ENV_IS_IN_NAND:
4404 Define this if you have a NAND device which you want to use
4405 for the environment.
4407 - CONFIG_ENV_OFFSET:
4410 These two #defines specify the offset and size of the environment
4411 area within the first NAND device. CONFIG_ENV_OFFSET must be
4412 aligned to an erase block boundary.
4414 - CONFIG_ENV_OFFSET_REDUND (optional):
4416 This setting describes a second storage area of CONFIG_ENV_SIZE
4417 size used to hold a redundant copy of the environment data, so
4418 that there is a valid backup copy in case there is a power failure
4419 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4420 aligned to an erase block boundary.
4422 - CONFIG_ENV_RANGE (optional):
4424 Specifies the length of the region in which the environment
4425 can be written. This should be a multiple of the NAND device's
4426 block size. Specifying a range with more erase blocks than
4427 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4428 the range to be avoided.
4430 - CONFIG_ENV_OFFSET_OOB (optional):
4432 Enables support for dynamically retrieving the offset of the
4433 environment from block zero's out-of-band data. The
4434 "nand env.oob" command can be used to record this offset.
4435 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4436 using CONFIG_ENV_OFFSET_OOB.
4438 - CONFIG_NAND_ENV_DST
4440 Defines address in RAM to which the nand_spl code should copy the
4441 environment. If redundant environment is used, it will be copied to
4442 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4444 - CONFIG_ENV_IS_IN_UBI:
4446 Define this if you have an UBI volume that you want to use for the
4447 environment. This has the benefit of wear-leveling the environment
4448 accesses, which is important on NAND.
4450 - CONFIG_ENV_UBI_PART:
4452 Define this to a string that is the mtd partition containing the UBI.
4454 - CONFIG_ENV_UBI_VOLUME:
4456 Define this to the name of the volume that you want to store the
4459 - CONFIG_ENV_UBI_VOLUME_REDUND:
4461 Define this to the name of another volume to store a second copy of
4462 the environment in. This will enable redundant environments in UBI.
4463 It is assumed that both volumes are in the same MTD partition.
4465 - CONFIG_UBI_SILENCE_MSG
4466 - CONFIG_UBIFS_SILENCE_MSG
4468 You will probably want to define these to avoid a really noisy system
4469 when storing the env in UBI.
4471 - CONFIG_ENV_IS_IN_FAT:
4472 Define this if you want to use the FAT file system for the environment.
4474 - FAT_ENV_INTERFACE:
4476 Define this to a string that is the name of the block device.
4478 - FAT_ENV_DEV_AND_PART:
4480 Define this to a string to specify the partition of the device. It can
4483 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4484 - "D:P": device D partition P. Error occurs if device D has no
4487 - "D" or "D:": device D partition 1 if device D has partition
4488 table, or the whole device D if has no partition
4490 - "D:auto": first partition in device D with bootable flag set.
4491 If none, first valid partition in device D. If no
4492 partition table then means device D.
4496 It's a string of the FAT file name. This file use to store the
4500 This should be defined. Otherwise it cannot save the environment file.
4502 - CONFIG_ENV_IS_IN_MMC:
4504 Define this if you have an MMC device which you want to use for the
4507 - CONFIG_SYS_MMC_ENV_DEV:
4509 Specifies which MMC device the environment is stored in.
4511 - CONFIG_SYS_MMC_ENV_PART (optional):
4513 Specifies which MMC partition the environment is stored in. If not
4514 set, defaults to partition 0, the user area. Common values might be
4515 1 (first MMC boot partition), 2 (second MMC boot partition).
4517 - CONFIG_ENV_OFFSET:
4520 These two #defines specify the offset and size of the environment
4521 area within the specified MMC device.
4523 If offset is positive (the usual case), it is treated as relative to
4524 the start of the MMC partition. If offset is negative, it is treated
4525 as relative to the end of the MMC partition. This can be useful if
4526 your board may be fitted with different MMC devices, which have
4527 different sizes for the MMC partitions, and you always want the
4528 environment placed at the very end of the partition, to leave the
4529 maximum possible space before it, to store other data.
4531 These two values are in units of bytes, but must be aligned to an
4532 MMC sector boundary.
4534 - CONFIG_ENV_OFFSET_REDUND (optional):
4536 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4537 hold a redundant copy of the environment data. This provides a
4538 valid backup copy in case the other copy is corrupted, e.g. due
4539 to a power failure during a "saveenv" operation.
4541 This value may also be positive or negative; this is handled in the
4542 same way as CONFIG_ENV_OFFSET.
4544 This value is also in units of bytes, but must also be aligned to
4545 an MMC sector boundary.
4547 - CONFIG_ENV_SIZE_REDUND (optional):
4549 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4550 set. If this value is set, it must be set to the same value as
4553 - CONFIG_SYS_SPI_INIT_OFFSET
4555 Defines offset to the initial SPI buffer area in DPRAM. The
4556 area is used at an early stage (ROM part) if the environment
4557 is configured to reside in the SPI EEPROM: We need a 520 byte
4558 scratch DPRAM area. It is used between the two initialization
4559 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4560 to be a good choice since it makes it far enough from the
4561 start of the data area as well as from the stack pointer.
4563 Please note that the environment is read-only until the monitor
4564 has been relocated to RAM and a RAM copy of the environment has been
4565 created; also, when using EEPROM you will have to use getenv_f()
4566 until then to read environment variables.
4568 The environment is protected by a CRC32 checksum. Before the monitor
4569 is relocated into RAM, as a result of a bad CRC you will be working
4570 with the compiled-in default environment - *silently*!!! [This is
4571 necessary, because the first environment variable we need is the
4572 "baudrate" setting for the console - if we have a bad CRC, we don't
4573 have any device yet where we could complain.]
4575 Note: once the monitor has been relocated, then it will complain if
4576 the default environment is used; a new CRC is computed as soon as you
4577 use the "saveenv" command to store a valid environment.
4579 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4580 Echo the inverted Ethernet link state to the fault LED.
4582 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4583 also needs to be defined.
4585 - CONFIG_SYS_FAULT_MII_ADDR:
4586 MII address of the PHY to check for the Ethernet link state.
4588 - CONFIG_NS16550_MIN_FUNCTIONS:
4589 Define this if you desire to only have use of the NS16550_init
4590 and NS16550_putc functions for the serial driver located at
4591 drivers/serial/ns16550.c. This option is useful for saving
4592 space for already greatly restricted images, including but not
4593 limited to NAND_SPL configurations.
4595 - CONFIG_DISPLAY_BOARDINFO
4596 Display information about the board that U-Boot is running on
4597 when U-Boot starts up. The board function checkboard() is called
4600 - CONFIG_DISPLAY_BOARDINFO_LATE
4601 Similar to the previous option, but display this information
4602 later, once stdio is running and output goes to the LCD, if
4605 - CONFIG_BOARD_SIZE_LIMIT:
4606 Maximum size of the U-Boot image. When defined, the
4607 build system checks that the actual size does not
4610 Low Level (hardware related) configuration options:
4611 ---------------------------------------------------
4613 - CONFIG_SYS_CACHELINE_SIZE:
4614 Cache Line Size of the CPU.
4616 - CONFIG_SYS_DEFAULT_IMMR:
4617 Default address of the IMMR after system reset.
4619 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4620 and RPXsuper) to be able to adjust the position of
4621 the IMMR register after a reset.
4623 - CONFIG_SYS_CCSRBAR_DEFAULT:
4624 Default (power-on reset) physical address of CCSR on Freescale
4627 - CONFIG_SYS_CCSRBAR:
4628 Virtual address of CCSR. On a 32-bit build, this is typically
4629 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4631 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4632 for cross-platform code that uses that macro instead.
4634 - CONFIG_SYS_CCSRBAR_PHYS:
4635 Physical address of CCSR. CCSR can be relocated to a new
4636 physical address, if desired. In this case, this macro should
4637 be set to that address. Otherwise, it should be set to the
4638 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4639 is typically relocated on 36-bit builds. It is recommended
4640 that this macro be defined via the _HIGH and _LOW macros:
4642 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4643 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4645 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4646 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4647 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4648 used in assembly code, so it must not contain typecasts or
4649 integer size suffixes (e.g. "ULL").
4651 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4652 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4653 used in assembly code, so it must not contain typecasts or
4654 integer size suffixes (e.g. "ULL").
4656 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4657 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4658 forced to a value that ensures that CCSR is not relocated.
4660 - Floppy Disk Support:
4661 CONFIG_SYS_FDC_DRIVE_NUMBER
4663 the default drive number (default value 0)
4665 CONFIG_SYS_ISA_IO_STRIDE
4667 defines the spacing between FDC chipset registers
4670 CONFIG_SYS_ISA_IO_OFFSET
4672 defines the offset of register from address. It
4673 depends on which part of the data bus is connected to
4674 the FDC chipset. (default value 0)
4676 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4677 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4680 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4681 fdc_hw_init() is called at the beginning of the FDC
4682 setup. fdc_hw_init() must be provided by the board
4683 source code. It is used to make hardware-dependent
4687 Most IDE controllers were designed to be connected with PCI
4688 interface. Only few of them were designed for AHB interface.
4689 When software is doing ATA command and data transfer to
4690 IDE devices through IDE-AHB controller, some additional
4691 registers accessing to these kind of IDE-AHB controller
4694 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4695 DO NOT CHANGE unless you know exactly what you're
4696 doing! (11-4) [MPC8xx/82xx systems only]
4698 - CONFIG_SYS_INIT_RAM_ADDR:
4700 Start address of memory area that can be used for
4701 initial data and stack; please note that this must be
4702 writable memory that is working WITHOUT special
4703 initialization, i. e. you CANNOT use normal RAM which
4704 will become available only after programming the
4705 memory controller and running certain initialization
4708 U-Boot uses the following memory types:
4709 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4710 - MPC824X: data cache
4711 - PPC4xx: data cache
4713 - CONFIG_SYS_GBL_DATA_OFFSET:
4715 Offset of the initial data structure in the memory
4716 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4717 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4718 data is located at the end of the available space
4719 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4720 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4721 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4722 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4725 On the MPC824X (or other systems that use the data
4726 cache for initial memory) the address chosen for
4727 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4728 point to an otherwise UNUSED address space between
4729 the top of RAM and the start of the PCI space.
4731 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4733 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4735 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4737 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4739 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4741 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4743 - CONFIG_SYS_OR_TIMING_SDRAM:
4746 - CONFIG_SYS_MAMR_PTA:
4747 periodic timer for refresh
4749 - CONFIG_SYS_DER: Debug Event Register (37-47)
4751 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4752 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4753 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4754 CONFIG_SYS_BR1_PRELIM:
4755 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4757 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4758 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4759 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4760 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4762 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4763 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4764 Machine Mode Register and Memory Periodic Timer
4765 Prescaler definitions (SDRAM timing)
4767 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4768 enable I2C microcode relocation patch (MPC8xx);
4769 define relocation offset in DPRAM [DSP2]
4771 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4772 enable SMC microcode relocation patch (MPC8xx);
4773 define relocation offset in DPRAM [SMC1]
4775 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4776 enable SPI microcode relocation patch (MPC8xx);
4777 define relocation offset in DPRAM [SCC4]
4779 - CONFIG_SYS_USE_OSCCLK:
4780 Use OSCM clock mode on MBX8xx board. Be careful,
4781 wrong setting might damage your board. Read
4782 doc/README.MBX before setting this variable!
4784 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4785 Offset of the bootmode word in DPRAM used by post
4786 (Power On Self Tests). This definition overrides
4787 #define'd default value in commproc.h resp.
4790 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4791 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4792 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4793 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4794 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4795 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4796 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4797 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4798 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4800 - CONFIG_PCI_DISABLE_PCIE:
4801 Disable PCI-Express on systems where it is supported but not
4804 - CONFIG_PCI_ENUM_ONLY
4805 Only scan through and get the devices on the buses.
4806 Don't do any setup work, presumably because someone or
4807 something has already done it, and we don't need to do it
4808 a second time. Useful for platforms that are pre-booted
4809 by coreboot or similar.
4811 - CONFIG_PCI_INDIRECT_BRIDGE:
4812 Enable support for indirect PCI bridges.
4815 Chip has SRIO or not
4818 Board has SRIO 1 port available
4821 Board has SRIO 2 port available
4823 - CONFIG_SRIO_PCIE_BOOT_MASTER
4824 Board can support master function for Boot from SRIO and PCIE
4826 - CONFIG_SYS_SRIOn_MEM_VIRT:
4827 Virtual Address of SRIO port 'n' memory region
4829 - CONFIG_SYS_SRIOn_MEM_PHYS:
4830 Physical Address of SRIO port 'n' memory region
4832 - CONFIG_SYS_SRIOn_MEM_SIZE:
4833 Size of SRIO port 'n' memory region
4835 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4836 Defined to tell the NAND controller that the NAND chip is using
4838 Not all NAND drivers use this symbol.
4839 Example of drivers that use it:
4840 - drivers/mtd/nand/ndfc.c
4841 - drivers/mtd/nand/mxc_nand.c
4843 - CONFIG_SYS_NDFC_EBC0_CFG
4844 Sets the EBC0_CFG register for the NDFC. If not defined
4845 a default value will be used.
4848 Get DDR timing information from an I2C EEPROM. Common
4849 with pluggable memory modules such as SODIMMs
4852 I2C address of the SPD EEPROM
4854 - CONFIG_SYS_SPD_BUS_NUM
4855 If SPD EEPROM is on an I2C bus other than the first
4856 one, specify here. Note that the value must resolve
4857 to something your driver can deal with.
4859 - CONFIG_SYS_DDR_RAW_TIMING
4860 Get DDR timing information from other than SPD. Common with
4861 soldered DDR chips onboard without SPD. DDR raw timing
4862 parameters are extracted from datasheet and hard-coded into
4863 header files or board specific files.
4865 - CONFIG_FSL_DDR_INTERACTIVE
4866 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4868 - CONFIG_FSL_DDR_SYNC_REFRESH
4869 Enable sync of refresh for multiple controllers.
4871 - CONFIG_FSL_DDR_BIST
4872 Enable built-in memory test for Freescale DDR controllers.
4874 - CONFIG_SYS_83XX_DDR_USES_CS0
4875 Only for 83xx systems. If specified, then DDR should
4876 be configured using CS0 and CS1 instead of CS2 and CS3.
4878 - CONFIG_ETHER_ON_FEC[12]
4879 Define to enable FEC[12] on a 8xx series processor.
4881 - CONFIG_FEC[12]_PHY
4882 Define to the hardcoded PHY address which corresponds
4883 to the given FEC; i. e.
4884 #define CONFIG_FEC1_PHY 4
4885 means that the PHY with address 4 is connected to FEC1
4887 When set to -1, means to probe for first available.
4889 - CONFIG_FEC[12]_PHY_NORXERR
4890 The PHY does not have a RXERR line (RMII only).
4891 (so program the FEC to ignore it).
4894 Enable RMII mode for all FECs.
4895 Note that this is a global option, we can't
4896 have one FEC in standard MII mode and another in RMII mode.
4898 - CONFIG_CRC32_VERIFY
4899 Add a verify option to the crc32 command.
4902 => crc32 -v <address> <count> <crc32>
4904 Where address/count indicate a memory area
4905 and crc32 is the correct crc32 which the
4909 Add the "loopw" memory command. This only takes effect if
4910 the memory commands are activated globally (CONFIG_CMD_MEM).
4913 Add the "mdc" and "mwc" memory commands. These are cyclic
4918 This command will print 4 bytes (10,11,12,13) each 500 ms.
4920 => mwc.l 100 12345678 10
4921 This command will write 12345678 to address 100 all 10 ms.
4923 This only takes effect if the memory commands are activated
4924 globally (CONFIG_CMD_MEM).
4926 - CONFIG_SKIP_LOWLEVEL_INIT
4927 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4928 low level initializations (like setting up the memory
4929 controller) are omitted and/or U-Boot does not
4930 relocate itself into RAM.
4932 Normally this variable MUST NOT be defined. The only
4933 exception is when U-Boot is loaded (to RAM) by some
4934 other boot loader or by a debugger which performs
4935 these initializations itself.
4938 Modifies the behaviour of start.S when compiling a loader
4939 that is executed before the actual U-Boot. E.g. when
4940 compiling a NAND SPL.
4943 Modifies the behaviour of start.S when compiling a loader
4944 that is executed after the SPL and before the actual U-Boot.
4945 It is loaded by the SPL.
4947 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4948 Only for 85xx systems. If this variable is specified, the section
4949 .resetvec is not kept and the section .bootpg is placed in the
4950 previous 4k of the .text section.
4952 - CONFIG_ARCH_MAP_SYSMEM
4953 Generally U-Boot (and in particular the md command) uses
4954 effective address. It is therefore not necessary to regard
4955 U-Boot address as virtual addresses that need to be translated
4956 to physical addresses. However, sandbox requires this, since
4957 it maintains its own little RAM buffer which contains all
4958 addressable memory. This option causes some memory accesses
4959 to be mapped through map_sysmem() / unmap_sysmem().
4961 - CONFIG_USE_ARCH_MEMCPY
4962 CONFIG_USE_ARCH_MEMSET
4963 If these options are used a optimized version of memcpy/memset will
4964 be used if available. These functions may be faster under some
4965 conditions but may increase the binary size.
4967 - CONFIG_X86_RESET_VECTOR
4968 If defined, the x86 reset vector code is included. This is not
4969 needed when U-Boot is running from Coreboot.
4972 Defines the MPU clock speed (in MHz).
4974 NOTE : currently only supported on AM335x platforms.
4976 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4977 Enables the RTC32K OSC on AM33xx based plattforms
4979 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4980 Option to disable subpage write in NAND driver
4981 driver that uses this:
4982 drivers/mtd/nand/davinci_nand.c
4984 Freescale QE/FMAN Firmware Support:
4985 -----------------------------------
4987 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4988 loading of "firmware", which is encoded in the QE firmware binary format.
4989 This firmware often needs to be loaded during U-Boot booting, so macros
4990 are used to identify the storage device (NOR flash, SPI, etc) and the address
4993 - CONFIG_SYS_FMAN_FW_ADDR
4994 The address in the storage device where the FMAN microcode is located. The
4995 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4998 - CONFIG_SYS_QE_FW_ADDR
4999 The address in the storage device where the QE microcode is located. The
5000 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5003 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5004 The maximum possible size of the firmware. The firmware binary format
5005 has a field that specifies the actual size of the firmware, but it
5006 might not be possible to read any part of the firmware unless some
5007 local storage is allocated to hold the entire firmware first.
5009 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5010 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5011 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5012 virtual address in NOR flash.
5014 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5015 Specifies that QE/FMAN firmware is located in NAND flash.
5016 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5018 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5019 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5020 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5022 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5023 Specifies that QE/FMAN firmware is located on the primary SPI
5024 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5026 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5027 Specifies that QE/FMAN firmware is located in the remote (master)
5028 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5029 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5030 window->master inbound window->master LAW->the ucode address in
5031 master's memory space.
5033 Freescale Layerscape Management Complex Firmware Support:
5034 ---------------------------------------------------------
5035 The Freescale Layerscape Management Complex (MC) supports the loading of
5037 This firmware often needs to be loaded during U-Boot booting, so macros
5038 are used to identify the storage device (NOR flash, SPI, etc) and the address
5041 - CONFIG_FSL_MC_ENET
5042 Enable the MC driver for Layerscape SoCs.
5044 - CONFIG_SYS_LS_MC_FW_ADDR
5045 The address in the storage device where the firmware is located. The
5046 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5049 - CONFIG_SYS_LS_MC_FW_LENGTH
5050 The maximum possible size of the firmware. The firmware binary format
5051 has a field that specifies the actual size of the firmware, but it
5052 might not be possible to read any part of the firmware unless some
5053 local storage is allocated to hold the entire firmware first.
5055 - CONFIG_SYS_LS_MC_FW_IN_NOR
5056 Specifies that MC firmware is located in NOR flash, mapped as
5057 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5058 virtual address in NOR flash.
5060 Freescale Layerscape Debug Server Support:
5061 -------------------------------------------
5062 The Freescale Layerscape Debug Server Support supports the loading of
5063 "Debug Server firmware" and triggering SP boot-rom.
5064 This firmware often needs to be loaded during U-Boot booting.
5066 - CONFIG_FSL_DEBUG_SERVER
5067 Enable the Debug Server for Layerscape SoCs.
5069 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5070 Define minimum DDR size required for debug server image
5072 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5073 Define minimum DDR size to be hided from top of the DDR memory
5078 In order to achieve reproducible builds, timestamps used in the U-Boot build
5079 process have to be set to a fixed value.
5081 This is done using the SOURCE_DATE_EPOCH environment variable.
5082 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5083 option for U-Boot or an environment variable in U-Boot.
5085 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5087 Building the Software:
5088 ======================
5090 Building U-Boot has been tested in several native build environments
5091 and in many different cross environments. Of course we cannot support
5092 all possibly existing versions of cross development tools in all
5093 (potentially obsolete) versions. In case of tool chain problems we
5094 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5095 which is extensively used to build and test U-Boot.
5097 If you are not using a native environment, it is assumed that you
5098 have GNU cross compiling tools available in your path. In this case,
5099 you must set the environment variable CROSS_COMPILE in your shell.
5100 Note that no changes to the Makefile or any other source files are
5101 necessary. For example using the ELDK on a 4xx CPU, please enter:
5103 $ CROSS_COMPILE=ppc_4xx-
5104 $ export CROSS_COMPILE
5106 Note: If you wish to generate Windows versions of the utilities in
5107 the tools directory you can use the MinGW toolchain
5108 (http://www.mingw.org). Set your HOST tools to the MinGW
5109 toolchain and execute 'make tools'. For example:
5111 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5113 Binaries such as tools/mkimage.exe will be created which can
5114 be executed on computers running Windows.
5116 U-Boot is intended to be simple to build. After installing the
5117 sources you must configure U-Boot for one specific board type. This
5122 where "NAME_defconfig" is the name of one of the existing configu-
5123 rations; see boards.cfg for supported names.
5125 Note: for some board special configuration names may exist; check if
5126 additional information is available from the board vendor; for
5127 instance, the TQM823L systems are available without (standard)
5128 or with LCD support. You can select such additional "features"
5129 when choosing the configuration, i. e.
5131 make TQM823L_defconfig
5132 - will configure for a plain TQM823L, i. e. no LCD support
5134 make TQM823L_LCD_defconfig
5135 - will configure for a TQM823L with U-Boot console on LCD
5140 Finally, type "make all", and you should get some working U-Boot
5141 images ready for download to / installation on your system:
5143 - "u-boot.bin" is a raw binary image
5144 - "u-boot" is an image in ELF binary format
5145 - "u-boot.srec" is in Motorola S-Record format
5147 By default the build is performed locally and the objects are saved
5148 in the source directory. One of the two methods can be used to change
5149 this behavior and build U-Boot to some external directory:
5151 1. Add O= to the make command line invocations:
5153 make O=/tmp/build distclean
5154 make O=/tmp/build NAME_defconfig
5155 make O=/tmp/build all
5157 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5159 export KBUILD_OUTPUT=/tmp/build
5164 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5168 Please be aware that the Makefiles assume you are using GNU make, so
5169 for instance on NetBSD you might need to use "gmake" instead of
5173 If the system board that you have is not listed, then you will need
5174 to port U-Boot to your hardware platform. To do this, follow these
5177 1. Add a new configuration option for your board to the toplevel
5178 "boards.cfg" file, using the existing entries as examples.
5179 Follow the instructions there to keep the boards in order.
5180 2. Create a new directory to hold your board specific code. Add any
5181 files you need. In your board directory, you will need at least
5182 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5183 3. Create a new configuration file "include/configs/<board>.h" for
5185 3. If you're porting U-Boot to a new CPU, then also create a new
5186 directory to hold your CPU specific code. Add any files you need.
5187 4. Run "make <board>_defconfig" with your new name.
5188 5. Type "make", and you should get a working "u-boot.srec" file
5189 to be installed on your target system.
5190 6. Debug and solve any problems that might arise.
5191 [Of course, this last step is much harder than it sounds.]
5194 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5195 ==============================================================
5197 If you have modified U-Boot sources (for instance added a new board
5198 or support for new devices, a new CPU, etc.) you are expected to
5199 provide feedback to the other developers. The feedback normally takes
5200 the form of a "patch", i. e. a context diff against a certain (latest
5201 official or latest in the git repository) version of U-Boot sources.
5203 But before you submit such a patch, please verify that your modifi-
5204 cation did not break existing code. At least make sure that *ALL* of
5205 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5206 just run the "MAKEALL" script, which will configure and build U-Boot
5207 for ALL supported system. Be warned, this will take a while. You can
5208 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5209 environment variable to the script, i. e. to use the ELDK cross tools
5212 CROSS_COMPILE=ppc_8xx- MAKEALL
5214 or to build on a native PowerPC system you can type
5216 CROSS_COMPILE=' ' MAKEALL
5218 When using the MAKEALL script, the default behaviour is to build
5219 U-Boot in the source directory. This location can be changed by
5220 setting the BUILD_DIR environment variable. Also, for each target
5221 built, the MAKEALL script saves two log files (<target>.ERR and
5222 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5223 location can be changed by setting the MAKEALL_LOGDIR environment
5224 variable. For example:
5226 export BUILD_DIR=/tmp/build
5227 export MAKEALL_LOGDIR=/tmp/log
5228 CROSS_COMPILE=ppc_8xx- MAKEALL
5230 With the above settings build objects are saved in the /tmp/build,
5231 log files are saved in the /tmp/log and the source tree remains clean
5232 during the whole build process.
5235 See also "U-Boot Porting Guide" below.
5238 Monitor Commands - Overview:
5239 ============================
5241 go - start application at address 'addr'
5242 run - run commands in an environment variable
5243 bootm - boot application image from memory
5244 bootp - boot image via network using BootP/TFTP protocol
5245 bootz - boot zImage from memory
5246 tftpboot- boot image via network using TFTP protocol
5247 and env variables "ipaddr" and "serverip"
5248 (and eventually "gatewayip")
5249 tftpput - upload a file via network using TFTP protocol
5250 rarpboot- boot image via network using RARP/TFTP protocol
5251 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5252 loads - load S-Record file over serial line
5253 loadb - load binary file over serial line (kermit mode)
5255 mm - memory modify (auto-incrementing)
5256 nm - memory modify (constant address)
5257 mw - memory write (fill)
5259 cmp - memory compare
5260 crc32 - checksum calculation
5261 i2c - I2C sub-system
5262 sspi - SPI utility commands
5263 base - print or set address offset
5264 printenv- print environment variables
5265 setenv - set environment variables
5266 saveenv - save environment variables to persistent storage
5267 protect - enable or disable FLASH write protection
5268 erase - erase FLASH memory
5269 flinfo - print FLASH memory information
5270 nand - NAND memory operations (see doc/README.nand)
5271 bdinfo - print Board Info structure
5272 iminfo - print header information for application image
5273 coninfo - print console devices and informations
5274 ide - IDE sub-system
5275 loop - infinite loop on address range
5276 loopw - infinite write loop on address range
5277 mtest - simple RAM test
5278 icache - enable or disable instruction cache
5279 dcache - enable or disable data cache
5280 reset - Perform RESET of the CPU
5281 echo - echo args to console
5282 version - print monitor version
5283 help - print online help
5284 ? - alias for 'help'
5287 Monitor Commands - Detailed Description:
5288 ========================================
5292 For now: just type "help <command>".
5295 Environment Variables:
5296 ======================
5298 U-Boot supports user configuration using Environment Variables which
5299 can be made persistent by saving to Flash memory.
5301 Environment Variables are set using "setenv", printed using
5302 "printenv", and saved to Flash using "saveenv". Using "setenv"
5303 without a value can be used to delete a variable from the
5304 environment. As long as you don't save the environment you are
5305 working with an in-memory copy. In case the Flash area containing the
5306 environment is erased by accident, a default environment is provided.
5308 Some configuration options can be set using Environment Variables.
5310 List of environment variables (most likely not complete):
5312 baudrate - see CONFIG_BAUDRATE
5314 bootdelay - see CONFIG_BOOTDELAY
5316 bootcmd - see CONFIG_BOOTCOMMAND
5318 bootargs - Boot arguments when booting an RTOS image
5320 bootfile - Name of the image to load with TFTP
5322 bootm_low - Memory range available for image processing in the bootm
5323 command can be restricted. This variable is given as
5324 a hexadecimal number and defines lowest address allowed
5325 for use by the bootm command. See also "bootm_size"
5326 environment variable. Address defined by "bootm_low" is
5327 also the base of the initial memory mapping for the Linux
5328 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5331 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5332 This variable is given as a hexadecimal number and it
5333 defines the size of the memory region starting at base
5334 address bootm_low that is accessible by the Linux kernel
5335 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5336 as the default value if it is defined, and bootm_size is
5339 bootm_size - Memory range available for image processing in the bootm
5340 command can be restricted. This variable is given as
5341 a hexadecimal number and defines the size of the region
5342 allowed for use by the bootm command. See also "bootm_low"
5343 environment variable.
5345 updatefile - Location of the software update file on a TFTP server, used
5346 by the automatic software update feature. Please refer to
5347 documentation in doc/README.update for more details.
5349 autoload - if set to "no" (any string beginning with 'n'),
5350 "bootp" will just load perform a lookup of the
5351 configuration from the BOOTP server, but not try to
5352 load any image using TFTP
5354 autostart - if set to "yes", an image loaded using the "bootp",
5355 "rarpboot", "tftpboot" or "diskboot" commands will
5356 be automatically started (by internally calling
5359 If set to "no", a standalone image passed to the
5360 "bootm" command will be copied to the load address
5361 (and eventually uncompressed), but NOT be started.
5362 This can be used to load and uncompress arbitrary
5365 fdt_high - if set this restricts the maximum address that the
5366 flattened device tree will be copied into upon boot.
5367 For example, if you have a system with 1 GB memory
5368 at physical address 0x10000000, while Linux kernel
5369 only recognizes the first 704 MB as low memory, you
5370 may need to set fdt_high as 0x3C000000 to have the
5371 device tree blob be copied to the maximum address
5372 of the 704 MB low memory, so that Linux kernel can
5373 access it during the boot procedure.
5375 If this is set to the special value 0xFFFFFFFF then
5376 the fdt will not be copied at all on boot. For this
5377 to work it must reside in writable memory, have
5378 sufficient padding on the end of it for u-boot to
5379 add the information it needs into it, and the memory
5380 must be accessible by the kernel.
5382 fdtcontroladdr- if set this is the address of the control flattened
5383 device tree used by U-Boot when CONFIG_OF_CONTROL is
5386 i2cfast - (PPC405GP|PPC405EP only)
5387 if set to 'y' configures Linux I2C driver for fast
5388 mode (400kHZ). This environment variable is used in
5389 initialization code. So, for changes to be effective
5390 it must be saved and board must be reset.
5392 initrd_high - restrict positioning of initrd images:
5393 If this variable is not set, initrd images will be
5394 copied to the highest possible address in RAM; this
5395 is usually what you want since it allows for
5396 maximum initrd size. If for some reason you want to
5397 make sure that the initrd image is loaded below the
5398 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5399 variable to a value of "no" or "off" or "0".
5400 Alternatively, you can set it to a maximum upper
5401 address to use (U-Boot will still check that it
5402 does not overwrite the U-Boot stack and data).
5404 For instance, when you have a system with 16 MB
5405 RAM, and want to reserve 4 MB from use by Linux,
5406 you can do this by adding "mem=12M" to the value of
5407 the "bootargs" variable. However, now you must make
5408 sure that the initrd image is placed in the first
5409 12 MB as well - this can be done with
5411 setenv initrd_high 00c00000
5413 If you set initrd_high to 0xFFFFFFFF, this is an
5414 indication to U-Boot that all addresses are legal
5415 for the Linux kernel, including addresses in flash
5416 memory. In this case U-Boot will NOT COPY the
5417 ramdisk at all. This may be useful to reduce the
5418 boot time on your system, but requires that this
5419 feature is supported by your Linux kernel.
5421 ipaddr - IP address; needed for tftpboot command
5423 loadaddr - Default load address for commands like "bootp",
5424 "rarpboot", "tftpboot", "loadb" or "diskboot"
5426 loads_echo - see CONFIG_LOADS_ECHO
5428 serverip - TFTP server IP address; needed for tftpboot command
5430 bootretry - see CONFIG_BOOT_RETRY_TIME
5432 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5434 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5436 ethprime - controls which interface is used first.
5438 ethact - controls which interface is currently active.
5439 For example you can do the following
5441 => setenv ethact FEC
5442 => ping 192.168.0.1 # traffic sent on FEC
5443 => setenv ethact SCC
5444 => ping 10.0.0.1 # traffic sent on SCC
5446 ethrotate - When set to "no" U-Boot does not go through all
5447 available network interfaces.
5448 It just stays at the currently selected interface.
5450 netretry - When set to "no" each network operation will
5451 either succeed or fail without retrying.
5452 When set to "once" the network operation will
5453 fail when all the available network interfaces
5454 are tried once without success.
5455 Useful on scripts which control the retry operation
5458 npe_ucode - set load address for the NPE microcode
5460 silent_linux - If set then Linux will be told to boot silently, by
5461 changing the console to be empty. If "yes" it will be
5462 made silent. If "no" it will not be made silent. If
5463 unset, then it will be made silent if the U-Boot console
5466 tftpsrcp - If this is set, the value is used for TFTP's
5469 tftpdstp - If this is set, the value is used for TFTP's UDP
5470 destination port instead of the Well Know Port 69.
5472 tftpblocksize - Block size to use for TFTP transfers; if not set,
5473 we use the TFTP server's default block size
5475 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5476 seconds, minimum value is 1000 = 1 second). Defines
5477 when a packet is considered to be lost so it has to
5478 be retransmitted. The default is 5000 = 5 seconds.
5479 Lowering this value may make downloads succeed
5480 faster in networks with high packet loss rates or
5481 with unreliable TFTP servers.
5483 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5484 unit, minimum value = 0). Defines how many timeouts
5485 can happen during a single file transfer before that
5486 transfer is aborted. The default is 10, and 0 means
5487 'no timeouts allowed'. Increasing this value may help
5488 downloads succeed with high packet loss rates, or with
5489 unreliable TFTP servers or client hardware.
5491 vlan - When set to a value < 4095 the traffic over
5492 Ethernet is encapsulated/received over 802.1q
5495 The following image location variables contain the location of images
5496 used in booting. The "Image" column gives the role of the image and is
5497 not an environment variable name. The other columns are environment
5498 variable names. "File Name" gives the name of the file on a TFTP
5499 server, "RAM Address" gives the location in RAM the image will be
5500 loaded to, and "Flash Location" gives the image's address in NOR
5501 flash or offset in NAND flash.
5503 *Note* - these variables don't have to be defined for all boards, some
5504 boards currently use other variables for these purposes, and some
5505 boards use these variables for other purposes.
5507 Image File Name RAM Address Flash Location
5508 ----- --------- ----------- --------------
5509 u-boot u-boot u-boot_addr_r u-boot_addr
5510 Linux kernel bootfile kernel_addr_r kernel_addr
5511 device tree blob fdtfile fdt_addr_r fdt_addr
5512 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5514 The following environment variables may be used and automatically
5515 updated by the network boot commands ("bootp" and "rarpboot"),
5516 depending the information provided by your boot server:
5518 bootfile - see above
5519 dnsip - IP address of your Domain Name Server
5520 dnsip2 - IP address of your secondary Domain Name Server
5521 gatewayip - IP address of the Gateway (Router) to use
5522 hostname - Target hostname
5524 netmask - Subnet Mask
5525 rootpath - Pathname of the root filesystem on the NFS server
5526 serverip - see above
5529 There are two special Environment Variables:
5531 serial# - contains hardware identification information such
5532 as type string and/or serial number
5533 ethaddr - Ethernet address
5535 These variables can be set only once (usually during manufacturing of
5536 the board). U-Boot refuses to delete or overwrite these variables
5537 once they have been set once.
5540 Further special Environment Variables:
5542 ver - Contains the U-Boot version string as printed
5543 with the "version" command. This variable is
5544 readonly (see CONFIG_VERSION_VARIABLE).
5547 Please note that changes to some configuration parameters may take
5548 only effect after the next boot (yes, that's just like Windoze :-).
5551 Callback functions for environment variables:
5552 ---------------------------------------------
5554 For some environment variables, the behavior of u-boot needs to change
5555 when their values are changed. This functionality allows functions to
5556 be associated with arbitrary variables. On creation, overwrite, or
5557 deletion, the callback will provide the opportunity for some side
5558 effect to happen or for the change to be rejected.
5560 The callbacks are named and associated with a function using the
5561 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5563 These callbacks are associated with variables in one of two ways. The
5564 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5565 in the board configuration to a string that defines a list of
5566 associations. The list must be in the following format:
5568 entry = variable_name[:callback_name]
5571 If the callback name is not specified, then the callback is deleted.
5572 Spaces are also allowed anywhere in the list.
5574 Callbacks can also be associated by defining the ".callbacks" variable
5575 with the same list format above. Any association in ".callbacks" will
5576 override any association in the static list. You can define
5577 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5578 ".callbacks" environment variable in the default or embedded environment.
5580 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5581 regular expression. This allows multiple variables to be connected to
5582 the same callback without explicitly listing them all out.
5585 Command Line Parsing:
5586 =====================
5588 There are two different command line parsers available with U-Boot:
5589 the old "simple" one, and the much more powerful "hush" shell:
5591 Old, simple command line parser:
5592 --------------------------------
5594 - supports environment variables (through setenv / saveenv commands)
5595 - several commands on one line, separated by ';'
5596 - variable substitution using "... ${name} ..." syntax
5597 - special characters ('$', ';') can be escaped by prefixing with '\',
5599 setenv bootcmd bootm \${address}
5600 - You can also escape text by enclosing in single apostrophes, for example:
5601 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5606 - similar to Bourne shell, with control structures like
5607 if...then...else...fi, for...do...done; while...do...done,
5608 until...do...done, ...
5609 - supports environment ("global") variables (through setenv / saveenv
5610 commands) and local shell variables (through standard shell syntax
5611 "name=value"); only environment variables can be used with "run"
5617 (1) If a command line (or an environment variable executed by a "run"
5618 command) contains several commands separated by semicolon, and
5619 one of these commands fails, then the remaining commands will be
5622 (2) If you execute several variables with one call to run (i. e.
5623 calling run with a list of variables as arguments), any failing
5624 command will cause "run" to terminate, i. e. the remaining
5625 variables are not executed.
5627 Note for Redundant Ethernet Interfaces:
5628 =======================================
5630 Some boards come with redundant Ethernet interfaces; U-Boot supports
5631 such configurations and is capable of automatic selection of a
5632 "working" interface when needed. MAC assignment works as follows:
5634 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5635 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5636 "eth1addr" (=>eth1), "eth2addr", ...
5638 If the network interface stores some valid MAC address (for instance
5639 in SROM), this is used as default address if there is NO correspon-
5640 ding setting in the environment; if the corresponding environment
5641 variable is set, this overrides the settings in the card; that means:
5643 o If the SROM has a valid MAC address, and there is no address in the
5644 environment, the SROM's address is used.
5646 o If there is no valid address in the SROM, and a definition in the
5647 environment exists, then the value from the environment variable is
5650 o If both the SROM and the environment contain a MAC address, and
5651 both addresses are the same, this MAC address is used.
5653 o If both the SROM and the environment contain a MAC address, and the
5654 addresses differ, the value from the environment is used and a
5657 o If neither SROM nor the environment contain a MAC address, an error
5658 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5659 a random, locally-assigned MAC is used.
5661 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5662 will be programmed into hardware as part of the initialization process. This
5663 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5664 The naming convention is as follows:
5665 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5670 U-Boot is capable of booting (and performing other auxiliary operations on)
5671 images in two formats:
5673 New uImage format (FIT)
5674 -----------------------
5676 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5677 to Flattened Device Tree). It allows the use of images with multiple
5678 components (several kernels, ramdisks, etc.), with contents protected by
5679 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5685 Old image format is based on binary files which can be basically anything,
5686 preceded by a special header; see the definitions in include/image.h for
5687 details; basically, the header defines the following image properties:
5689 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5690 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5691 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5692 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5694 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5695 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5696 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5697 * Compression Type (uncompressed, gzip, bzip2)
5703 The header is marked by a special Magic Number, and both the header
5704 and the data portions of the image are secured against corruption by
5711 Although U-Boot should support any OS or standalone application
5712 easily, the main focus has always been on Linux during the design of
5715 U-Boot includes many features that so far have been part of some
5716 special "boot loader" code within the Linux kernel. Also, any
5717 "initrd" images to be used are no longer part of one big Linux image;
5718 instead, kernel and "initrd" are separate images. This implementation
5719 serves several purposes:
5721 - the same features can be used for other OS or standalone
5722 applications (for instance: using compressed images to reduce the
5723 Flash memory footprint)
5725 - it becomes much easier to port new Linux kernel versions because
5726 lots of low-level, hardware dependent stuff are done by U-Boot
5728 - the same Linux kernel image can now be used with different "initrd"
5729 images; of course this also means that different kernel images can
5730 be run with the same "initrd". This makes testing easier (you don't
5731 have to build a new "zImage.initrd" Linux image when you just
5732 change a file in your "initrd"). Also, a field-upgrade of the
5733 software is easier now.
5739 Porting Linux to U-Boot based systems:
5740 ---------------------------------------
5742 U-Boot cannot save you from doing all the necessary modifications to
5743 configure the Linux device drivers for use with your target hardware
5744 (no, we don't intend to provide a full virtual machine interface to
5747 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5749 Just make sure your machine specific header file (for instance
5750 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5751 Information structure as we define in include/asm-<arch>/u-boot.h,
5752 and make sure that your definition of IMAP_ADDR uses the same value
5753 as your U-Boot configuration in CONFIG_SYS_IMMR.
5755 Note that U-Boot now has a driver model, a unified model for drivers.
5756 If you are adding a new driver, plumb it into driver model. If there
5757 is no uclass available, you are encouraged to create one. See
5761 Configuring the Linux kernel:
5762 -----------------------------
5764 No specific requirements for U-Boot. Make sure you have some root
5765 device (initial ramdisk, NFS) for your target system.
5768 Building a Linux Image:
5769 -----------------------
5771 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5772 not used. If you use recent kernel source, a new build target
5773 "uImage" will exist which automatically builds an image usable by
5774 U-Boot. Most older kernels also have support for a "pImage" target,
5775 which was introduced for our predecessor project PPCBoot and uses a
5776 100% compatible format.
5780 make TQM850L_defconfig
5785 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5786 encapsulate a compressed Linux kernel image with header information,
5787 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5789 * build a standard "vmlinux" kernel image (in ELF binary format):
5791 * convert the kernel into a raw binary image:
5793 ${CROSS_COMPILE}-objcopy -O binary \
5794 -R .note -R .comment \
5795 -S vmlinux linux.bin
5797 * compress the binary image:
5801 * package compressed binary image for U-Boot:
5803 mkimage -A ppc -O linux -T kernel -C gzip \
5804 -a 0 -e 0 -n "Linux Kernel Image" \
5805 -d linux.bin.gz uImage
5808 The "mkimage" tool can also be used to create ramdisk images for use
5809 with U-Boot, either separated from the Linux kernel image, or
5810 combined into one file. "mkimage" encapsulates the images with a 64
5811 byte header containing information about target architecture,
5812 operating system, image type, compression method, entry points, time
5813 stamp, CRC32 checksums, etc.
5815 "mkimage" can be called in two ways: to verify existing images and
5816 print the header information, or to build new images.
5818 In the first form (with "-l" option) mkimage lists the information
5819 contained in the header of an existing U-Boot image; this includes
5820 checksum verification:
5822 tools/mkimage -l image
5823 -l ==> list image header information
5825 The second form (with "-d" option) is used to build a U-Boot image
5826 from a "data file" which is used as image payload:
5828 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5829 -n name -d data_file image
5830 -A ==> set architecture to 'arch'
5831 -O ==> set operating system to 'os'
5832 -T ==> set image type to 'type'
5833 -C ==> set compression type 'comp'
5834 -a ==> set load address to 'addr' (hex)
5835 -e ==> set entry point to 'ep' (hex)
5836 -n ==> set image name to 'name'
5837 -d ==> use image data from 'datafile'
5839 Right now, all Linux kernels for PowerPC systems use the same load
5840 address (0x00000000), but the entry point address depends on the
5843 - 2.2.x kernels have the entry point at 0x0000000C,
5844 - 2.3.x and later kernels have the entry point at 0x00000000.
5846 So a typical call to build a U-Boot image would read:
5848 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5849 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5850 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5851 > examples/uImage.TQM850L
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 (gzip compressed)
5855 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5856 Load Address: 0x00000000
5857 Entry Point: 0x00000000
5859 To verify the contents of the image (or check for corruption):
5861 -> tools/mkimage -l examples/uImage.TQM850L
5862 Image Name: 2.4.4 kernel for TQM850L
5863 Created: Wed Jul 19 02:34:59 2000
5864 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5865 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5866 Load Address: 0x00000000
5867 Entry Point: 0x00000000
5869 NOTE: for embedded systems where boot time is critical you can trade
5870 speed for memory and install an UNCOMPRESSED image instead: this
5871 needs more space in Flash, but boots much faster since it does not
5872 need to be uncompressed:
5874 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5875 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5876 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5877 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5878 > examples/uImage.TQM850L-uncompressed
5879 Image Name: 2.4.4 kernel for TQM850L
5880 Created: Wed Jul 19 02:34:59 2000
5881 Image Type: PowerPC Linux Kernel Image (uncompressed)
5882 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5883 Load Address: 0x00000000
5884 Entry Point: 0x00000000
5887 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5888 when your kernel is intended to use an initial ramdisk:
5890 -> tools/mkimage -n 'Simple Ramdisk Image' \
5891 > -A ppc -O linux -T ramdisk -C gzip \
5892 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5893 Image Name: Simple Ramdisk Image
5894 Created: Wed Jan 12 14:01:50 2000
5895 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5896 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5897 Load Address: 0x00000000
5898 Entry Point: 0x00000000
5900 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5901 option performs the converse operation of the mkimage's second form (the "-d"
5902 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5905 tools/dumpimage -i image -T type -p position data_file
5906 -i ==> extract from the 'image' a specific 'data_file'
5907 -T ==> set image type to 'type'
5908 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5911 Installing a Linux Image:
5912 -------------------------
5914 To downloading a U-Boot image over the serial (console) interface,
5915 you must convert the image to S-Record format:
5917 objcopy -I binary -O srec examples/image examples/image.srec
5919 The 'objcopy' does not understand the information in the U-Boot
5920 image header, so the resulting S-Record file will be relative to
5921 address 0x00000000. To load it to a given address, you need to
5922 specify the target address as 'offset' parameter with the 'loads'
5925 Example: install the image to address 0x40100000 (which on the
5926 TQM8xxL is in the first Flash bank):
5928 => erase 40100000 401FFFFF
5934 ## Ready for S-Record download ...
5935 ~>examples/image.srec
5936 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5938 15989 15990 15991 15992
5939 [file transfer complete]
5941 ## Start Addr = 0x00000000
5944 You can check the success of the download using the 'iminfo' command;
5945 this includes a checksum verification so you can be sure no data
5946 corruption happened:
5950 ## Checking Image at 40100000 ...
5951 Image Name: 2.2.13 for initrd on TQM850L
5952 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5953 Data Size: 335725 Bytes = 327 kB = 0 MB
5954 Load Address: 00000000
5955 Entry Point: 0000000c
5956 Verifying Checksum ... OK
5962 The "bootm" command is used to boot an application that is stored in
5963 memory (RAM or Flash). In case of a Linux kernel image, the contents
5964 of the "bootargs" environment variable is passed to the kernel as
5965 parameters. You can check and modify this variable using the
5966 "printenv" and "setenv" commands:
5969 => printenv bootargs
5970 bootargs=root=/dev/ram
5972 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5974 => printenv bootargs
5975 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5978 ## Booting Linux kernel at 40020000 ...
5979 Image Name: 2.2.13 for NFS on TQM850L
5980 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5981 Data Size: 381681 Bytes = 372 kB = 0 MB
5982 Load Address: 00000000
5983 Entry Point: 0000000c
5984 Verifying Checksum ... OK
5985 Uncompressing Kernel Image ... OK
5986 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
5987 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5988 time_init: decrementer frequency = 187500000/60
5989 Calibrating delay loop... 49.77 BogoMIPS
5990 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5993 If you want to boot a Linux kernel with initial RAM disk, you pass
5994 the memory addresses of both the kernel and the initrd image (PPBCOOT
5995 format!) to the "bootm" command:
5997 => imi 40100000 40200000
5999 ## Checking Image at 40100000 ...
6000 Image Name: 2.2.13 for initrd on TQM850L
6001 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6002 Data Size: 335725 Bytes = 327 kB = 0 MB
6003 Load Address: 00000000
6004 Entry Point: 0000000c
6005 Verifying Checksum ... OK
6007 ## Checking Image at 40200000 ...
6008 Image Name: Simple Ramdisk Image
6009 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6010 Data Size: 566530 Bytes = 553 kB = 0 MB
6011 Load Address: 00000000
6012 Entry Point: 00000000
6013 Verifying Checksum ... OK
6015 => bootm 40100000 40200000
6016 ## Booting Linux kernel at 40100000 ...
6017 Image Name: 2.2.13 for initrd on TQM850L
6018 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6019 Data Size: 335725 Bytes = 327 kB = 0 MB
6020 Load Address: 00000000
6021 Entry Point: 0000000c
6022 Verifying Checksum ... OK
6023 Uncompressing Kernel Image ... OK
6024 ## Loading RAMDisk Image at 40200000 ...
6025 Image Name: Simple Ramdisk Image
6026 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6027 Data Size: 566530 Bytes = 553 kB = 0 MB
6028 Load Address: 00000000
6029 Entry Point: 00000000
6030 Verifying Checksum ... OK
6031 Loading Ramdisk ... OK
6032 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
6033 Boot arguments: root=/dev/ram
6034 time_init: decrementer frequency = 187500000/60
6035 Calibrating delay loop... 49.77 BogoMIPS
6037 RAMDISK: Compressed image found at block 0
6038 VFS: Mounted root (ext2 filesystem).
6042 Boot Linux and pass a flat device tree:
6045 First, U-Boot must be compiled with the appropriate defines. See the section
6046 titled "Linux Kernel Interface" above for a more in depth explanation. The
6047 following is an example of how to start a kernel and pass an updated
6053 oft=oftrees/mpc8540ads.dtb
6054 => tftp $oftaddr $oft
6055 Speed: 1000, full duplex
6057 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6058 Filename 'oftrees/mpc8540ads.dtb'.
6059 Load address: 0x300000
6062 Bytes transferred = 4106 (100a hex)
6063 => tftp $loadaddr $bootfile
6064 Speed: 1000, full duplex
6066 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6068 Load address: 0x200000
6069 Loading:############
6071 Bytes transferred = 1029407 (fb51f hex)
6076 => bootm $loadaddr - $oftaddr
6077 ## Booting image at 00200000 ...
6078 Image Name: Linux-2.6.17-dirty
6079 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6080 Data Size: 1029343 Bytes = 1005.2 kB
6081 Load Address: 00000000
6082 Entry Point: 00000000
6083 Verifying Checksum ... OK
6084 Uncompressing Kernel Image ... OK
6085 Booting using flat device tree at 0x300000
6086 Using MPC85xx ADS machine description
6087 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6091 More About U-Boot Image Types:
6092 ------------------------------
6094 U-Boot supports the following image types:
6096 "Standalone Programs" are directly runnable in the environment
6097 provided by U-Boot; it is expected that (if they behave
6098 well) you can continue to work in U-Boot after return from
6099 the Standalone Program.
6100 "OS Kernel Images" are usually images of some Embedded OS which
6101 will take over control completely. Usually these programs
6102 will install their own set of exception handlers, device
6103 drivers, set up the MMU, etc. - this means, that you cannot
6104 expect to re-enter U-Boot except by resetting the CPU.
6105 "RAMDisk Images" are more or less just data blocks, and their
6106 parameters (address, size) are passed to an OS kernel that is
6108 "Multi-File Images" contain several images, typically an OS
6109 (Linux) kernel image and one or more data images like
6110 RAMDisks. This construct is useful for instance when you want
6111 to boot over the network using BOOTP etc., where the boot
6112 server provides just a single image file, but you want to get
6113 for instance an OS kernel and a RAMDisk image.
6115 "Multi-File Images" start with a list of image sizes, each
6116 image size (in bytes) specified by an "uint32_t" in network
6117 byte order. This list is terminated by an "(uint32_t)0".
6118 Immediately after the terminating 0 follow the images, one by
6119 one, all aligned on "uint32_t" boundaries (size rounded up to
6120 a multiple of 4 bytes).
6122 "Firmware Images" are binary images containing firmware (like
6123 U-Boot or FPGA images) which usually will be programmed to
6126 "Script files" are command sequences that will be executed by
6127 U-Boot's command interpreter; this feature is especially
6128 useful when you configure U-Boot to use a real shell (hush)
6129 as command interpreter.
6131 Booting the Linux zImage:
6132 -------------------------
6134 On some platforms, it's possible to boot Linux zImage. This is done
6135 using the "bootz" command. The syntax of "bootz" command is the same
6136 as the syntax of "bootm" command.
6138 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6139 kernel with raw initrd images. The syntax is slightly different, the
6140 address of the initrd must be augmented by it's size, in the following
6141 format: "<initrd addres>:<initrd size>".
6147 One of the features of U-Boot is that you can dynamically load and
6148 run "standalone" applications, which can use some resources of
6149 U-Boot like console I/O functions or interrupt services.
6151 Two simple examples are included with the sources:
6156 'examples/hello_world.c' contains a small "Hello World" Demo
6157 application; it is automatically compiled when you build U-Boot.
6158 It's configured to run at address 0x00040004, so you can play with it
6162 ## Ready for S-Record download ...
6163 ~>examples/hello_world.srec
6164 1 2 3 4 5 6 7 8 9 10 11 ...
6165 [file transfer complete]
6167 ## Start Addr = 0x00040004
6169 => go 40004 Hello World! This is a test.
6170 ## Starting application at 0x00040004 ...
6181 Hit any key to exit ...
6183 ## Application terminated, rc = 0x0
6185 Another example, which demonstrates how to register a CPM interrupt
6186 handler with the U-Boot code, can be found in 'examples/timer.c'.
6187 Here, a CPM timer is set up to generate an interrupt every second.
6188 The interrupt service routine is trivial, just printing a '.'
6189 character, but this is just a demo program. The application can be
6190 controlled by the following keys:
6192 ? - print current values og the CPM Timer registers
6193 b - enable interrupts and start timer
6194 e - stop timer and disable interrupts
6195 q - quit application
6198 ## Ready for S-Record download ...
6199 ~>examples/timer.srec
6200 1 2 3 4 5 6 7 8 9 10 11 ...
6201 [file transfer complete]
6203 ## Start Addr = 0x00040004
6206 ## Starting application at 0x00040004 ...
6209 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6212 [q, b, e, ?] Set interval 1000000 us
6215 [q, b, e, ?] ........
6216 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6219 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6222 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6225 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6227 [q, b, e, ?] ...Stopping timer
6229 [q, b, e, ?] ## Application terminated, rc = 0x0
6235 Over time, many people have reported problems when trying to use the
6236 "minicom" terminal emulation program for serial download. I (wd)
6237 consider minicom to be broken, and recommend not to use it. Under
6238 Unix, I recommend to use C-Kermit for general purpose use (and
6239 especially for kermit binary protocol download ("loadb" command), and
6240 use "cu" for S-Record download ("loads" command). See
6241 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6242 for help with kermit.
6245 Nevertheless, if you absolutely want to use it try adding this
6246 configuration to your "File transfer protocols" section:
6248 Name Program Name U/D FullScr IO-Red. Multi
6249 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6250 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6256 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6257 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6259 Building requires a cross environment; it is known to work on
6260 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6261 need gmake since the Makefiles are not compatible with BSD make).
6262 Note that the cross-powerpc package does not install include files;
6263 attempting to build U-Boot will fail because <machine/ansi.h> is
6264 missing. This file has to be installed and patched manually:
6266 # cd /usr/pkg/cross/powerpc-netbsd/include
6268 # ln -s powerpc machine
6269 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6270 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6272 Native builds *don't* work due to incompatibilities between native
6273 and U-Boot include files.
6275 Booting assumes that (the first part of) the image booted is a
6276 stage-2 loader which in turn loads and then invokes the kernel
6277 proper. Loader sources will eventually appear in the NetBSD source
6278 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6279 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6282 Implementation Internals:
6283 =========================
6285 The following is not intended to be a complete description of every
6286 implementation detail. However, it should help to understand the
6287 inner workings of U-Boot and make it easier to port it to custom
6291 Initial Stack, Global Data:
6292 ---------------------------
6294 The implementation of U-Boot is complicated by the fact that U-Boot
6295 starts running out of ROM (flash memory), usually without access to
6296 system RAM (because the memory controller is not initialized yet).
6297 This means that we don't have writable Data or BSS segments, and BSS
6298 is not initialized as zero. To be able to get a C environment working
6299 at all, we have to allocate at least a minimal stack. Implementation
6300 options for this are defined and restricted by the CPU used: Some CPU
6301 models provide on-chip memory (like the IMMR area on MPC8xx and
6302 MPC826x processors), on others (parts of) the data cache can be
6303 locked as (mis-) used as memory, etc.
6305 Chris Hallinan posted a good summary of these issues to the
6306 U-Boot mailing list:
6308 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6309 From: "Chris Hallinan" <clh@net1plus.com>
6310 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6313 Correct me if I'm wrong, folks, but the way I understand it
6314 is this: Using DCACHE as initial RAM for Stack, etc, does not
6315 require any physical RAM backing up the cache. The cleverness
6316 is that the cache is being used as a temporary supply of
6317 necessary storage before the SDRAM controller is setup. It's
6318 beyond the scope of this list to explain the details, but you
6319 can see how this works by studying the cache architecture and
6320 operation in the architecture and processor-specific manuals.
6322 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6323 is another option for the system designer to use as an
6324 initial stack/RAM area prior to SDRAM being available. Either
6325 option should work for you. Using CS 4 should be fine if your
6326 board designers haven't used it for something that would
6327 cause you grief during the initial boot! It is frequently not
6330 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6331 with your processor/board/system design. The default value
6332 you will find in any recent u-boot distribution in
6333 walnut.h should work for you. I'd set it to a value larger
6334 than your SDRAM module. If you have a 64MB SDRAM module, set
6335 it above 400_0000. Just make sure your board has no resources
6336 that are supposed to respond to that address! That code in
6337 start.S has been around a while and should work as is when
6338 you get the config right.
6343 It is essential to remember this, since it has some impact on the C
6344 code for the initialization procedures:
6346 * Initialized global data (data segment) is read-only. Do not attempt
6349 * Do not use any uninitialized global data (or implicitly initialized
6350 as zero data - BSS segment) at all - this is undefined, initiali-
6351 zation is performed later (when relocating to RAM).
6353 * Stack space is very limited. Avoid big data buffers or things like
6356 Having only the stack as writable memory limits means we cannot use
6357 normal global data to share information between the code. But it
6358 turned out that the implementation of U-Boot can be greatly
6359 simplified by making a global data structure (gd_t) available to all
6360 functions. We could pass a pointer to this data as argument to _all_
6361 functions, but this would bloat the code. Instead we use a feature of
6362 the GCC compiler (Global Register Variables) to share the data: we
6363 place a pointer (gd) to the global data into a register which we
6364 reserve for this purpose.
6366 When choosing a register for such a purpose we are restricted by the
6367 relevant (E)ABI specifications for the current architecture, and by
6368 GCC's implementation.
6370 For PowerPC, the following registers have specific use:
6372 R2: reserved for system use
6373 R3-R4: parameter passing and return values
6374 R5-R10: parameter passing
6375 R13: small data area pointer
6379 (U-Boot also uses R12 as internal GOT pointer. r12
6380 is a volatile register so r12 needs to be reset when
6381 going back and forth between asm and C)
6383 ==> U-Boot will use R2 to hold a pointer to the global data
6385 Note: on PPC, we could use a static initializer (since the
6386 address of the global data structure is known at compile time),
6387 but it turned out that reserving a register results in somewhat
6388 smaller code - although the code savings are not that big (on
6389 average for all boards 752 bytes for the whole U-Boot image,
6390 624 text + 127 data).
6392 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6393 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6395 ==> U-Boot will use P3 to hold a pointer to the global data
6397 On ARM, the following registers are used:
6399 R0: function argument word/integer result
6400 R1-R3: function argument word
6401 R9: platform specific
6402 R10: stack limit (used only if stack checking is enabled)
6403 R11: argument (frame) pointer
6404 R12: temporary workspace
6407 R15: program counter
6409 ==> U-Boot will use R9 to hold a pointer to the global data
6411 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6413 On Nios II, the ABI is documented here:
6414 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6416 ==> U-Boot will use gp to hold a pointer to the global data
6418 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6419 to access small data sections, so gp is free.
6421 On NDS32, the following registers are used:
6423 R0-R1: argument/return
6425 R15: temporary register for assembler
6426 R16: trampoline register
6427 R28: frame pointer (FP)
6428 R29: global pointer (GP)
6429 R30: link register (LP)
6430 R31: stack pointer (SP)
6431 PC: program counter (PC)
6433 ==> U-Boot will use R10 to hold a pointer to the global data
6435 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6436 or current versions of GCC may "optimize" the code too much.
6441 U-Boot runs in system state and uses physical addresses, i.e. the
6442 MMU is not used either for address mapping nor for memory protection.
6444 The available memory is mapped to fixed addresses using the memory
6445 controller. In this process, a contiguous block is formed for each
6446 memory type (Flash, SDRAM, SRAM), even when it consists of several
6447 physical memory banks.
6449 U-Boot is installed in the first 128 kB of the first Flash bank (on
6450 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6451 booting and sizing and initializing DRAM, the code relocates itself
6452 to the upper end of DRAM. Immediately below the U-Boot code some
6453 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6454 configuration setting]. Below that, a structure with global Board
6455 Info data is placed, followed by the stack (growing downward).
6457 Additionally, some exception handler code is copied to the low 8 kB
6458 of DRAM (0x00000000 ... 0x00001FFF).
6460 So a typical memory configuration with 16 MB of DRAM could look like
6463 0x0000 0000 Exception Vector code
6466 0x0000 2000 Free for Application Use
6472 0x00FB FF20 Monitor Stack (Growing downward)
6473 0x00FB FFAC Board Info Data and permanent copy of global data
6474 0x00FC 0000 Malloc Arena
6477 0x00FE 0000 RAM Copy of Monitor Code
6478 ... eventually: LCD or video framebuffer
6479 ... eventually: pRAM (Protected RAM - unchanged by reset)
6480 0x00FF FFFF [End of RAM]
6483 System Initialization:
6484 ----------------------
6486 In the reset configuration, U-Boot starts at the reset entry point
6487 (on most PowerPC systems at address 0x00000100). Because of the reset
6488 configuration for CS0# this is a mirror of the on board Flash memory.
6489 To be able to re-map memory U-Boot then jumps to its link address.
6490 To be able to implement the initialization code in C, a (small!)
6491 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6492 which provide such a feature like MPC8xx or MPC8260), or in a locked
6493 part of the data cache. After that, U-Boot initializes the CPU core,
6494 the caches and the SIU.
6496 Next, all (potentially) available memory banks are mapped using a
6497 preliminary mapping. For example, we put them on 512 MB boundaries
6498 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6499 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6500 programmed for SDRAM access. Using the temporary configuration, a
6501 simple memory test is run that determines the size of the SDRAM
6504 When there is more than one SDRAM bank, and the banks are of
6505 different size, the largest is mapped first. For equal size, the first
6506 bank (CS2#) is mapped first. The first mapping is always for address
6507 0x00000000, with any additional banks following immediately to create
6508 contiguous memory starting from 0.
6510 Then, the monitor installs itself at the upper end of the SDRAM area
6511 and allocates memory for use by malloc() and for the global Board
6512 Info data; also, the exception vector code is copied to the low RAM
6513 pages, and the final stack is set up.
6515 Only after this relocation will you have a "normal" C environment;
6516 until that you are restricted in several ways, mostly because you are
6517 running from ROM, and because the code will have to be relocated to a
6521 U-Boot Porting Guide:
6522 ----------------------
6524 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6528 int main(int argc, char *argv[])
6530 sighandler_t no_more_time;
6532 signal(SIGALRM, no_more_time);
6533 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6535 if (available_money > available_manpower) {
6536 Pay consultant to port U-Boot;
6540 Download latest U-Boot source;
6542 Subscribe to u-boot mailing list;
6545 email("Hi, I am new to U-Boot, how do I get started?");
6548 Read the README file in the top level directory;
6549 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6550 Read applicable doc/*.README;
6551 Read the source, Luke;
6552 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6555 if (available_money > toLocalCurrency ($2500))
6558 Add a lot of aggravation and time;
6560 if (a similar board exists) { /* hopefully... */
6561 cp -a board/<similar> board/<myboard>
6562 cp include/configs/<similar>.h include/configs/<myboard>.h
6564 Create your own board support subdirectory;
6565 Create your own board include/configs/<myboard>.h file;
6567 Edit new board/<myboard> files
6568 Edit new include/configs/<myboard>.h
6573 Add / modify source code;
6577 email("Hi, I am having problems...");
6579 Send patch file to the U-Boot email list;
6580 if (reasonable critiques)
6581 Incorporate improvements from email list code review;
6583 Defend code as written;
6589 void no_more_time (int sig)
6598 All contributions to U-Boot should conform to the Linux kernel
6599 coding style; see the file "Documentation/CodingStyle" and the script
6600 "scripts/Lindent" in your Linux kernel source directory.
6602 Source files originating from a different project (for example the
6603 MTD subsystem) are generally exempt from these guidelines and are not
6604 reformatted to ease subsequent migration to newer versions of those
6607 Please note that U-Boot is implemented in C (and to some small parts in
6608 Assembler); no C++ is used, so please do not use C++ style comments (//)
6611 Please also stick to the following formatting rules:
6612 - remove any trailing white space
6613 - use TAB characters for indentation and vertical alignment, not spaces
6614 - make sure NOT to use DOS '\r\n' line feeds
6615 - do not add more than 2 consecutive empty lines to source files
6616 - do not add trailing empty lines to source files
6618 Submissions which do not conform to the standards may be returned
6619 with a request to reformat the changes.
6625 Since the number of patches for U-Boot is growing, we need to
6626 establish some rules. Submissions which do not conform to these rules
6627 may be rejected, even when they contain important and valuable stuff.
6629 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6631 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6632 see http://lists.denx.de/mailman/listinfo/u-boot
6634 When you send a patch, please include the following information with
6637 * For bug fixes: a description of the bug and how your patch fixes
6638 this bug. Please try to include a way of demonstrating that the
6639 patch actually fixes something.
6641 * For new features: a description of the feature and your
6644 * A CHANGELOG entry as plaintext (separate from the patch)
6646 * For major contributions, your entry to the CREDITS file
6648 * When you add support for a new board, don't forget to add a
6649 maintainer e-mail address to the boards.cfg file, too.
6651 * If your patch adds new configuration options, don't forget to
6652 document these in the README file.
6654 * The patch itself. If you are using git (which is *strongly*
6655 recommended) you can easily generate the patch using the
6656 "git format-patch". If you then use "git send-email" to send it to
6657 the U-Boot mailing list, you will avoid most of the common problems
6658 with some other mail clients.
6660 If you cannot use git, use "diff -purN OLD NEW". If your version of
6661 diff does not support these options, then get the latest version of
6664 The current directory when running this command shall be the parent
6665 directory of the U-Boot source tree (i. e. please make sure that
6666 your patch includes sufficient directory information for the
6669 We prefer patches as plain text. MIME attachments are discouraged,
6670 and compressed attachments must not be used.
6672 * If one logical set of modifications affects or creates several
6673 files, all these changes shall be submitted in a SINGLE patch file.
6675 * Changesets that contain different, unrelated modifications shall be
6676 submitted as SEPARATE patches, one patch per changeset.
6681 * Before sending the patch, run the MAKEALL script on your patched
6682 source tree and make sure that no errors or warnings are reported
6683 for any of the boards.
6685 * Keep your modifications to the necessary minimum: A patch
6686 containing several unrelated changes or arbitrary reformats will be
6687 returned with a request to re-formatting / split it.
6689 * If you modify existing code, make sure that your new code does not
6690 add to the memory footprint of the code ;-) Small is beautiful!
6691 When adding new features, these should compile conditionally only
6692 (using #ifdef), and the resulting code with the new feature
6693 disabled must not need more memory than the old code without your
6696 * Remember that there is a size limit of 100 kB per message on the
6697 u-boot mailing list. Bigger patches will be moderated. If they are
6698 reasonable and not too big, they will be acknowledged. But patches
6699 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob