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_VIDEO_LOGO display Linux logo in
877 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
878 linux_logo.h for logo.
879 Requires CONFIG_VIDEO_LOGO
880 CONFIG_CONSOLE_EXTRA_INFO
881 additional board info beside
884 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
885 a limited number of ANSI escape sequences (cursor control,
886 erase functions and limited graphics rendition control).
888 When CONFIG_CFB_CONSOLE is defined, video console is
889 default i/o. Serial console can be forced with
890 environment 'console=serial'.
892 When CONFIG_SILENT_CONSOLE is defined, all console
893 messages (by U-Boot and Linux!) can be silenced with
894 the "silent" environment variable. See
895 doc/README.silent for more information.
897 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
899 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
903 CONFIG_BAUDRATE - in bps
904 Select one of the baudrates listed in
905 CONFIG_SYS_BAUDRATE_TABLE, see below.
906 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
908 - Console Rx buffer length
909 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
910 the maximum receive buffer length for the SMC.
911 This option is actual only for 82xx and 8xx possible.
912 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
913 must be defined, to setup the maximum idle timeout for
916 - Pre-Console Buffer:
917 Prior to the console being initialised (i.e. serial UART
918 initialised etc) all console output is silently discarded.
919 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
920 buffer any console messages prior to the console being
921 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
922 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
923 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
924 bytes are output before the console is initialised, the
925 earlier bytes are discarded.
927 Note that when printing the buffer a copy is made on the
928 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
930 'Sane' compilers will generate smaller code if
931 CONFIG_PRE_CON_BUF_SZ is a power of 2
933 - Safe printf() functions
934 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
935 the printf() functions. These are defined in
936 include/vsprintf.h and include snprintf(), vsnprintf() and
937 so on. Code size increase is approximately 300-500 bytes.
938 If this option is not given then these functions will
939 silently discard their buffer size argument - this means
940 you are not getting any overflow checking in this case.
942 - Boot Delay: CONFIG_BOOTDELAY - in seconds
943 Delay before automatically booting the default image;
944 set to -1 to disable autoboot.
945 set to -2 to autoboot with no delay and not check for abort
946 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
948 See doc/README.autoboot for these options that
949 work with CONFIG_BOOTDELAY. None are required.
950 CONFIG_BOOT_RETRY_TIME
951 CONFIG_BOOT_RETRY_MIN
952 CONFIG_AUTOBOOT_KEYED
953 CONFIG_AUTOBOOT_PROMPT
954 CONFIG_AUTOBOOT_DELAY_STR
955 CONFIG_AUTOBOOT_STOP_STR
956 CONFIG_ZERO_BOOTDELAY_CHECK
957 CONFIG_RESET_TO_RETRY
961 Only needed when CONFIG_BOOTDELAY is enabled;
962 define a command string that is automatically executed
963 when no character is read on the console interface
964 within "Boot Delay" after reset.
967 This can be used to pass arguments to the bootm
968 command. The value of CONFIG_BOOTARGS goes into the
969 environment value "bootargs".
971 CONFIG_RAMBOOT and CONFIG_NFSBOOT
972 The value of these goes into the environment as
973 "ramboot" and "nfsboot" respectively, and can be used
974 as a convenience, when switching between booting from
978 CONFIG_BOOTCOUNT_LIMIT
979 Implements a mechanism for detecting a repeating reboot
981 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
984 If no softreset save registers are found on the hardware
985 "bootcount" is stored in the environment. To prevent a
986 saveenv on all reboots, the environment variable
987 "upgrade_available" is used. If "upgrade_available" is
988 0, "bootcount" is always 0, if "upgrade_available" is
989 1 "bootcount" is incremented in the environment.
990 So the Userspace Applikation must set the "upgrade_available"
991 and "bootcount" variable to 0, if a boot was successfully.
996 When this option is #defined, the existence of the
997 environment variable "preboot" will be checked
998 immediately before starting the CONFIG_BOOTDELAY
999 countdown and/or running the auto-boot command resp.
1000 entering interactive mode.
1002 This feature is especially useful when "preboot" is
1003 automatically generated or modified. For an example
1004 see the LWMON board specific code: here "preboot" is
1005 modified when the user holds down a certain
1006 combination of keys on the (special) keyboard when
1009 - Serial Download Echo Mode:
1011 If defined to 1, all characters received during a
1012 serial download (using the "loads" command) are
1013 echoed back. This might be needed by some terminal
1014 emulations (like "cu"), but may as well just take
1015 time on others. This setting #define's the initial
1016 value of the "loads_echo" environment variable.
1018 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1019 CONFIG_KGDB_BAUDRATE
1020 Select one of the baudrates listed in
1021 CONFIG_SYS_BAUDRATE_TABLE, see below.
1023 - Monitor Functions:
1024 Monitor commands can be included or excluded
1025 from the build by using the #include files
1026 <config_cmd_all.h> and #undef'ing unwanted
1027 commands, or adding #define's for wanted commands.
1029 The default command configuration includes all commands
1030 except those marked below with a "*".
1032 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1033 CONFIG_CMD_ASKENV * ask for env variable
1034 CONFIG_CMD_BDI bdinfo
1035 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1036 CONFIG_CMD_BMP * BMP support
1037 CONFIG_CMD_BSP * Board specific commands
1038 CONFIG_CMD_BOOTD bootd
1039 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1040 CONFIG_CMD_CACHE * icache, dcache
1041 CONFIG_CMD_CLK * clock command support
1042 CONFIG_CMD_CONSOLE coninfo
1043 CONFIG_CMD_CRC32 * crc32
1044 CONFIG_CMD_DATE * support for RTC, date/time...
1045 CONFIG_CMD_DHCP * DHCP support
1046 CONFIG_CMD_DIAG * Diagnostics
1047 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1048 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1049 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1050 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1051 CONFIG_CMD_DTT * Digital Therm and Thermostat
1052 CONFIG_CMD_ECHO echo arguments
1053 CONFIG_CMD_EDITENV edit env variable
1054 CONFIG_CMD_EEPROM * EEPROM read/write support
1055 CONFIG_CMD_ELF * bootelf, bootvx
1056 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1057 CONFIG_CMD_ENV_FLAGS * display details about env flags
1058 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1059 CONFIG_CMD_EXPORTENV * export the environment
1060 CONFIG_CMD_EXT2 * ext2 command support
1061 CONFIG_CMD_EXT4 * ext4 command support
1062 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1063 that work for multiple fs types
1064 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1065 CONFIG_CMD_SAVEENV saveenv
1066 CONFIG_CMD_FDC * Floppy Disk Support
1067 CONFIG_CMD_FAT * FAT command support
1068 CONFIG_CMD_FLASH flinfo, erase, protect
1069 CONFIG_CMD_FPGA FPGA device initialization support
1070 CONFIG_CMD_FUSE * Device fuse support
1071 CONFIG_CMD_GETTIME * Get time since boot
1072 CONFIG_CMD_GO * the 'go' command (exec code)
1073 CONFIG_CMD_GREPENV * search environment
1074 CONFIG_CMD_HASH * calculate hash / digest
1075 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1076 CONFIG_CMD_I2C * I2C serial bus support
1077 CONFIG_CMD_IDE * IDE harddisk support
1078 CONFIG_CMD_IMI iminfo
1079 CONFIG_CMD_IMLS List all images found in NOR flash
1080 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1081 CONFIG_CMD_IMMAP * IMMR dump support
1082 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1083 CONFIG_CMD_IMPORTENV * import an environment
1084 CONFIG_CMD_INI * import data from an ini file into the env
1085 CONFIG_CMD_IRQ * irqinfo
1086 CONFIG_CMD_ITEST Integer/string test of 2 values
1087 CONFIG_CMD_JFFS2 * JFFS2 Support
1088 CONFIG_CMD_KGDB * kgdb
1089 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1090 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1092 CONFIG_CMD_LOADB loadb
1093 CONFIG_CMD_LOADS loads
1094 CONFIG_CMD_MD5SUM * print md5 message digest
1095 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1096 CONFIG_CMD_MEMINFO * Display detailed memory information
1097 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1099 CONFIG_CMD_MEMTEST * mtest
1100 CONFIG_CMD_MISC Misc functions like sleep etc
1101 CONFIG_CMD_MMC * MMC memory mapped support
1102 CONFIG_CMD_MII * MII utility commands
1103 CONFIG_CMD_MTDPARTS * MTD partition support
1104 CONFIG_CMD_NAND * NAND support
1105 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1106 CONFIG_CMD_NFS NFS support
1107 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1108 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1109 CONFIG_CMD_PCI * pciinfo
1110 CONFIG_CMD_PCMCIA * PCMCIA support
1111 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1113 CONFIG_CMD_PORTIO * Port I/O
1114 CONFIG_CMD_READ * Read raw data from partition
1115 CONFIG_CMD_REGINFO * Register dump
1116 CONFIG_CMD_RUN run command in env variable
1117 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1118 CONFIG_CMD_SAVES * save S record dump
1119 CONFIG_CMD_SCSI * SCSI Support
1120 CONFIG_CMD_SDRAM * print SDRAM configuration information
1121 (requires CONFIG_CMD_I2C)
1122 CONFIG_CMD_SETGETDCR Support for DCR Register access
1124 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1125 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1126 (requires CONFIG_CMD_MEMORY)
1127 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1128 CONFIG_CMD_SOURCE "source" command Support
1129 CONFIG_CMD_SPI * SPI serial bus support
1130 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1131 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1132 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1133 CONFIG_CMD_TIMER * access to the system tick timer
1134 CONFIG_CMD_USB * USB support
1135 CONFIG_CMD_CDP * Cisco Discover Protocol support
1136 CONFIG_CMD_MFSL * Microblaze FSL support
1137 CONFIG_CMD_XIMG Load part of Multi Image
1138 CONFIG_CMD_UUID * Generate random UUID or GUID string
1140 EXAMPLE: If you want all functions except of network
1141 support you can write:
1143 #include "config_cmd_all.h"
1144 #undef CONFIG_CMD_NET
1147 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1149 Note: Don't enable the "icache" and "dcache" commands
1150 (configuration option CONFIG_CMD_CACHE) unless you know
1151 what you (and your U-Boot users) are doing. Data
1152 cache cannot be enabled on systems like the 8xx or
1153 8260 (where accesses to the IMMR region must be
1154 uncached), and it cannot be disabled on all other
1155 systems where we (mis-) use the data cache to hold an
1156 initial stack and some data.
1159 XXX - this list needs to get updated!
1161 - Regular expression support:
1163 If this variable is defined, U-Boot is linked against
1164 the SLRE (Super Light Regular Expression) library,
1165 which adds regex support to some commands, as for
1166 example "env grep" and "setexpr".
1170 If this variable is defined, U-Boot will use a device tree
1171 to configure its devices, instead of relying on statically
1172 compiled #defines in the board file. This option is
1173 experimental and only available on a few boards. The device
1174 tree is available in the global data as gd->fdt_blob.
1176 U-Boot needs to get its device tree from somewhere. This can
1177 be done using one of the two options below:
1180 If this variable is defined, U-Boot will embed a device tree
1181 binary in its image. This device tree file should be in the
1182 board directory and called <soc>-<board>.dts. The binary file
1183 is then picked up in board_init_f() and made available through
1184 the global data structure as gd->blob.
1187 If this variable is defined, U-Boot will build a device tree
1188 binary. It will be called u-boot.dtb. Architecture-specific
1189 code will locate it at run-time. Generally this works by:
1191 cat u-boot.bin u-boot.dtb >image.bin
1193 and in fact, U-Boot does this for you, creating a file called
1194 u-boot-dtb.bin which is useful in the common case. You can
1195 still use the individual files if you need something more
1200 If this variable is defined, it enables watchdog
1201 support for the SoC. There must be support in the SoC
1202 specific code for a watchdog. For the 8xx and 8260
1203 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1204 register. When supported for a specific SoC is
1205 available, then no further board specific code should
1206 be needed to use it.
1209 When using a watchdog circuitry external to the used
1210 SoC, then define this variable and provide board
1211 specific code for the "hw_watchdog_reset" function.
1213 CONFIG_AT91_HW_WDT_TIMEOUT
1214 specify the timeout in seconds. default 2 seconds.
1217 CONFIG_VERSION_VARIABLE
1218 If this variable is defined, an environment variable
1219 named "ver" is created by U-Boot showing the U-Boot
1220 version as printed by the "version" command.
1221 Any change to this variable will be reverted at the
1226 When CONFIG_CMD_DATE is selected, the type of the RTC
1227 has to be selected, too. Define exactly one of the
1230 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1231 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1232 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1233 CONFIG_RTC_MC146818 - use MC146818 RTC
1234 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1235 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1236 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1237 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1238 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1239 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1240 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1241 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1242 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1245 Note that if the RTC uses I2C, then the I2C interface
1246 must also be configured. See I2C Support, below.
1249 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1251 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1252 chip-ngpio pairs that tell the PCA953X driver the number of
1253 pins supported by a particular chip.
1255 Note that if the GPIO device uses I2C, then the I2C interface
1256 must also be configured. See I2C Support, below.
1259 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1260 accesses and can checksum them or write a list of them out
1261 to memory. See the 'iotrace' command for details. This is
1262 useful for testing device drivers since it can confirm that
1263 the driver behaves the same way before and after a code
1264 change. Currently this is supported on sandbox and arm. To
1265 add support for your architecture, add '#include <iotrace.h>'
1266 to the bottom of arch/<arch>/include/asm/io.h and test.
1268 Example output from the 'iotrace stats' command is below.
1269 Note that if the trace buffer is exhausted, the checksum will
1270 still continue to operate.
1273 Start: 10000000 (buffer start address)
1274 Size: 00010000 (buffer size)
1275 Offset: 00000120 (current buffer offset)
1276 Output: 10000120 (start + offset)
1277 Count: 00000018 (number of trace records)
1278 CRC32: 9526fb66 (CRC32 of all trace records)
1280 - Timestamp Support:
1282 When CONFIG_TIMESTAMP is selected, the timestamp
1283 (date and time) of an image is printed by image
1284 commands like bootm or iminfo. This option is
1285 automatically enabled when you select CONFIG_CMD_DATE .
1287 - Partition Labels (disklabels) Supported:
1288 Zero or more of the following:
1289 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1290 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1291 Intel architecture, USB sticks, etc.
1292 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1293 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1294 bootloader. Note 2TB partition limit; see
1296 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1298 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1299 CONFIG_CMD_SCSI) you must configure support for at
1300 least one non-MTD partition type as well.
1303 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1304 board configurations files but used nowhere!
1306 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1307 be performed by calling the function
1308 ide_set_reset(int reset)
1309 which has to be defined in a board specific file
1314 Set this to enable ATAPI support.
1319 Set this to enable support for disks larger than 137GB
1320 Also look at CONFIG_SYS_64BIT_LBA.
1321 Whithout these , LBA48 support uses 32bit variables and will 'only'
1322 support disks up to 2.1TB.
1324 CONFIG_SYS_64BIT_LBA:
1325 When enabled, makes the IDE subsystem use 64bit sector addresses.
1329 At the moment only there is only support for the
1330 SYM53C8XX SCSI controller; define
1331 CONFIG_SCSI_SYM53C8XX to enable it.
1333 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1334 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1335 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1336 maximum numbers of LUNs, SCSI ID's and target
1338 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1340 The environment variable 'scsidevs' is set to the number of
1341 SCSI devices found during the last scan.
1343 - NETWORK Support (PCI):
1345 Support for Intel 8254x/8257x gigabit chips.
1348 Utility code for direct access to the SPI bus on Intel 8257x.
1349 This does not do anything useful unless you set at least one
1350 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1352 CONFIG_E1000_SPI_GENERIC
1353 Allow generic access to the SPI bus on the Intel 8257x, for
1354 example with the "sspi" command.
1357 Management command for E1000 devices. When used on devices
1358 with SPI support you can reprogram the EEPROM from U-Boot.
1361 Support for Intel 82557/82559/82559ER chips.
1362 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1363 write routine for first time initialisation.
1366 Support for Digital 2114x chips.
1367 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1368 modem chip initialisation (KS8761/QS6611).
1371 Support for National dp83815 chips.
1374 Support for National dp8382[01] gigabit chips.
1376 - NETWORK Support (other):
1378 CONFIG_DRIVER_AT91EMAC
1379 Support for AT91RM9200 EMAC.
1382 Define this to use reduced MII inteface
1384 CONFIG_DRIVER_AT91EMAC_QUIET
1385 If this defined, the driver is quiet.
1386 The driver doen't show link status messages.
1388 CONFIG_CALXEDA_XGMAC
1389 Support for the Calxeda XGMAC device
1392 Support for SMSC's LAN91C96 chips.
1394 CONFIG_LAN91C96_BASE
1395 Define this to hold the physical address
1396 of the LAN91C96's I/O space
1398 CONFIG_LAN91C96_USE_32_BIT
1399 Define this to enable 32 bit addressing
1402 Support for SMSC's LAN91C111 chip
1404 CONFIG_SMC91111_BASE
1405 Define this to hold the physical address
1406 of the device (I/O space)
1408 CONFIG_SMC_USE_32_BIT
1409 Define this if data bus is 32 bits
1411 CONFIG_SMC_USE_IOFUNCS
1412 Define this to use i/o functions instead of macros
1413 (some hardware wont work with macros)
1415 CONFIG_DRIVER_TI_EMAC
1416 Support for davinci emac
1418 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1419 Define this if you have more then 3 PHYs.
1422 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1424 CONFIG_FTGMAC100_EGIGA
1425 Define this to use GE link update with gigabit PHY.
1426 Define this if FTGMAC100 is connected to gigabit PHY.
1427 If your system has 10/100 PHY only, it might not occur
1428 wrong behavior. Because PHY usually return timeout or
1429 useless data when polling gigabit status and gigabit
1430 control registers. This behavior won't affect the
1431 correctnessof 10/100 link speed update.
1434 Support for SMSC's LAN911x and LAN921x chips
1437 Define this to hold the physical address
1438 of the device (I/O space)
1440 CONFIG_SMC911X_32_BIT
1441 Define this if data bus is 32 bits
1443 CONFIG_SMC911X_16_BIT
1444 Define this if data bus is 16 bits. If your processor
1445 automatically converts one 32 bit word to two 16 bit
1446 words you may also try CONFIG_SMC911X_32_BIT.
1449 Support for Renesas on-chip Ethernet controller
1451 CONFIG_SH_ETHER_USE_PORT
1452 Define the number of ports to be used
1454 CONFIG_SH_ETHER_PHY_ADDR
1455 Define the ETH PHY's address
1457 CONFIG_SH_ETHER_CACHE_WRITEBACK
1458 If this option is set, the driver enables cache flush.
1462 Support for PWM modul on the imx6.
1466 Support TPM devices.
1468 CONFIG_TPM_TIS_INFINEON
1469 Support for Infineon i2c bus TPM devices. Only one device
1470 per system is supported at this time.
1472 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1473 Define the burst count bytes upper limit
1475 CONFIG_TPM_ATMEL_TWI
1476 Support for Atmel TWI TPM device. Requires I2C support.
1479 Support for generic parallel port TPM devices. Only one device
1480 per system is supported at this time.
1482 CONFIG_TPM_TIS_BASE_ADDRESS
1483 Base address where the generic TPM device is mapped
1484 to. Contemporary x86 systems usually map it at
1488 Add tpm monitor functions.
1489 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1490 provides monitor access to authorized functions.
1493 Define this to enable the TPM support library which provides
1494 functional interfaces to some TPM commands.
1495 Requires support for a TPM device.
1497 CONFIG_TPM_AUTH_SESSIONS
1498 Define this to enable authorized functions in the TPM library.
1499 Requires CONFIG_TPM and CONFIG_SHA1.
1502 At the moment only the UHCI host controller is
1503 supported (PIP405, MIP405, MPC5200); define
1504 CONFIG_USB_UHCI to enable it.
1505 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1506 and define CONFIG_USB_STORAGE to enable the USB
1509 Supported are USB Keyboards and USB Floppy drives
1511 MPC5200 USB requires additional defines:
1513 for 528 MHz Clock: 0x0001bbbb
1517 for differential drivers: 0x00001000
1518 for single ended drivers: 0x00005000
1519 for differential drivers on PSC3: 0x00000100
1520 for single ended drivers on PSC3: 0x00004100
1521 CONFIG_SYS_USB_EVENT_POLL
1522 May be defined to allow interrupt polling
1523 instead of using asynchronous interrupts
1525 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1526 txfilltuning field in the EHCI controller on reset.
1528 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1529 HW module registers.
1532 Define the below if you wish to use the USB console.
1533 Once firmware is rebuilt from a serial console issue the
1534 command "setenv stdin usbtty; setenv stdout usbtty" and
1535 attach your USB cable. The Unix command "dmesg" should print
1536 it has found a new device. The environment variable usbtty
1537 can be set to gserial or cdc_acm to enable your device to
1538 appear to a USB host as a Linux gserial device or a
1539 Common Device Class Abstract Control Model serial device.
1540 If you select usbtty = gserial you should be able to enumerate
1542 # modprobe usbserial vendor=0xVendorID product=0xProductID
1543 else if using cdc_acm, simply setting the environment
1544 variable usbtty to be cdc_acm should suffice. The following
1545 might be defined in YourBoardName.h
1548 Define this to build a UDC device
1551 Define this to have a tty type of device available to
1552 talk to the UDC device
1555 Define this to enable the high speed support for usb
1556 device and usbtty. If this feature is enabled, a routine
1557 int is_usbd_high_speed(void)
1558 also needs to be defined by the driver to dynamically poll
1559 whether the enumeration has succeded at high speed or full
1562 CONFIG_SYS_CONSOLE_IS_IN_ENV
1563 Define this if you want stdin, stdout &/or stderr to
1567 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1568 Derive USB clock from external clock "blah"
1569 - CONFIG_SYS_USB_EXTC_CLK 0x02
1571 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1572 Derive USB clock from brgclk
1573 - CONFIG_SYS_USB_BRG_CLK 0x04
1575 If you have a USB-IF assigned VendorID then you may wish to
1576 define your own vendor specific values either in BoardName.h
1577 or directly in usbd_vendor_info.h. If you don't define
1578 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1579 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1580 should pretend to be a Linux device to it's target host.
1582 CONFIG_USBD_MANUFACTURER
1583 Define this string as the name of your company for
1584 - CONFIG_USBD_MANUFACTURER "my company"
1586 CONFIG_USBD_PRODUCT_NAME
1587 Define this string as the name of your product
1588 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1590 CONFIG_USBD_VENDORID
1591 Define this as your assigned Vendor ID from the USB
1592 Implementors Forum. This *must* be a genuine Vendor ID
1593 to avoid polluting the USB namespace.
1594 - CONFIG_USBD_VENDORID 0xFFFF
1596 CONFIG_USBD_PRODUCTID
1597 Define this as the unique Product ID
1599 - CONFIG_USBD_PRODUCTID 0xFFFF
1601 - ULPI Layer Support:
1602 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1603 the generic ULPI layer. The generic layer accesses the ULPI PHY
1604 via the platform viewport, so you need both the genric layer and
1605 the viewport enabled. Currently only Chipidea/ARC based
1606 viewport is supported.
1607 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1608 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1609 If your ULPI phy needs a different reference clock than the
1610 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1611 the appropriate value in Hz.
1614 The MMC controller on the Intel PXA is supported. To
1615 enable this define CONFIG_MMC. The MMC can be
1616 accessed from the boot prompt by mapping the device
1617 to physical memory similar to flash. Command line is
1618 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1619 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1622 Support for Renesas on-chip MMCIF controller
1624 CONFIG_SH_MMCIF_ADDR
1625 Define the base address of MMCIF registers
1628 Define the clock frequency for MMCIF
1631 Enable the generic MMC driver
1633 CONFIG_SUPPORT_EMMC_BOOT
1634 Enable some additional features of the eMMC boot partitions.
1636 CONFIG_SUPPORT_EMMC_RPMB
1637 Enable the commands for reading, writing and programming the
1638 key for the Replay Protection Memory Block partition in eMMC.
1640 - USB Device Firmware Update (DFU) class support:
1641 CONFIG_USB_FUNCTION_DFU
1642 This enables the USB portion of the DFU USB class
1645 This enables the command "dfu" which is used to have
1646 U-Boot create a DFU class device via USB. This command
1647 requires that the "dfu_alt_info" environment variable be
1648 set and define the alt settings to expose to the host.
1651 This enables support for exposing (e)MMC devices via DFU.
1654 This enables support for exposing NAND devices via DFU.
1657 This enables support for exposing RAM via DFU.
1658 Note: DFU spec refer to non-volatile memory usage, but
1659 allow usages beyond the scope of spec - here RAM usage,
1660 one that would help mostly the developer.
1662 CONFIG_SYS_DFU_DATA_BUF_SIZE
1663 Dfu transfer uses a buffer before writing data to the
1664 raw storage device. Make the size (in bytes) of this buffer
1665 configurable. The size of this buffer is also configurable
1666 through the "dfu_bufsiz" environment variable.
1668 CONFIG_SYS_DFU_MAX_FILE_SIZE
1669 When updating files rather than the raw storage device,
1670 we use a static buffer to copy the file into and then write
1671 the buffer once we've been given the whole file. Define
1672 this to the maximum filesize (in bytes) for the buffer.
1673 Default is 4 MiB if undefined.
1675 DFU_DEFAULT_POLL_TIMEOUT
1676 Poll timeout [ms], is the timeout a device can send to the
1677 host. The host must wait for this timeout before sending
1678 a subsequent DFU_GET_STATUS request to the device.
1680 DFU_MANIFEST_POLL_TIMEOUT
1681 Poll timeout [ms], which the device sends to the host when
1682 entering dfuMANIFEST state. Host waits this timeout, before
1683 sending again an USB request to the device.
1685 - USB Device Android Fastboot support:
1686 CONFIG_USB_FUNCTION_FASTBOOT
1687 This enables the USB part of the fastboot gadget
1690 This enables the command "fastboot" which enables the Android
1691 fastboot mode for the platform's USB device. Fastboot is a USB
1692 protocol for downloading images, flashing and device control
1693 used on Android devices.
1694 See doc/README.android-fastboot for more information.
1696 CONFIG_ANDROID_BOOT_IMAGE
1697 This enables support for booting images which use the Android
1698 image format header.
1700 CONFIG_FASTBOOT_BUF_ADDR
1701 The fastboot protocol requires a large memory buffer for
1702 downloads. Define this to the starting RAM address to use for
1705 CONFIG_FASTBOOT_BUF_SIZE
1706 The fastboot protocol requires a large memory buffer for
1707 downloads. This buffer should be as large as possible for a
1708 platform. Define this to the size available RAM for fastboot.
1710 CONFIG_FASTBOOT_FLASH
1711 The fastboot protocol includes a "flash" command for writing
1712 the downloaded image to a non-volatile storage device. Define
1713 this to enable the "fastboot flash" command.
1715 CONFIG_FASTBOOT_FLASH_MMC_DEV
1716 The fastboot "flash" command requires additional information
1717 regarding the non-volatile storage device. Define this to
1718 the eMMC device that fastboot should use to store the image.
1720 CONFIG_FASTBOOT_GPT_NAME
1721 The fastboot "flash" command supports writing the downloaded
1722 image to the Protective MBR and the Primary GUID Partition
1723 Table. (Additionally, this downloaded image is post-processed
1724 to generate and write the Backup GUID Partition Table.)
1725 This occurs when the specified "partition name" on the
1726 "fastboot flash" command line matches this value.
1727 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1729 - Journaling Flash filesystem support:
1730 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1731 CONFIG_JFFS2_NAND_DEV
1732 Define these for a default partition on a NAND device
1734 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1735 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1736 Define these for a default partition on a NOR device
1738 CONFIG_SYS_JFFS_CUSTOM_PART
1739 Define this to create an own partition. You have to provide a
1740 function struct part_info* jffs2_part_info(int part_num)
1742 If you define only one JFFS2 partition you may also want to
1743 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1744 to disable the command chpart. This is the default when you
1745 have not defined a custom partition
1747 - FAT(File Allocation Table) filesystem write function support:
1750 Define this to enable support for saving memory data as a
1751 file in FAT formatted partition.
1753 This will also enable the command "fatwrite" enabling the
1754 user to write files to FAT.
1756 CBFS (Coreboot Filesystem) support
1759 Define this to enable support for reading from a Coreboot
1760 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1763 - FAT(File Allocation Table) filesystem cluster size:
1764 CONFIG_FS_FAT_MAX_CLUSTSIZE
1766 Define the max cluster size for fat operations else
1767 a default value of 65536 will be defined.
1771 Standard PC keyboard driver with US (is default) and
1772 GERMAN key layout (switch via environment 'keymap=de') support.
1773 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1774 for cfb_console. Supports cursor blinking.
1779 Define this to enable video support (for output to
1782 CONFIG_VIDEO_CT69000
1784 Enable Chips & Technologies 69000 Video chip
1786 CONFIG_VIDEO_SMI_LYNXEM
1787 Enable Silicon Motion SMI 712/710/810 Video chip. The
1788 video output is selected via environment 'videoout'
1789 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1792 For the CT69000 and SMI_LYNXEM drivers, videomode is
1793 selected via environment 'videomode'. Two different ways
1795 - "videomode=num" 'num' is a standard LiLo mode numbers.
1796 Following standard modes are supported (* is default):
1798 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1799 -------------+---------------------------------------------
1800 8 bits | 0x301* 0x303 0x305 0x161 0x307
1801 15 bits | 0x310 0x313 0x316 0x162 0x319
1802 16 bits | 0x311 0x314 0x317 0x163 0x31A
1803 24 bits | 0x312 0x315 0x318 ? 0x31B
1804 -------------+---------------------------------------------
1805 (i.e. setenv videomode 317; saveenv; reset;)
1807 - "videomode=bootargs" all the video parameters are parsed
1808 from the bootargs. (See drivers/video/videomodes.c)
1811 CONFIG_VIDEO_SED13806
1812 Enable Epson SED13806 driver. This driver supports 8bpp
1813 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1814 or CONFIG_VIDEO_SED13806_16BPP
1817 Enable the Freescale DIU video driver. Reference boards for
1818 SOCs that have a DIU should define this macro to enable DIU
1819 support, and should also define these other macros:
1825 CONFIG_VIDEO_SW_CURSOR
1826 CONFIG_VGA_AS_SINGLE_DEVICE
1828 CONFIG_VIDEO_BMP_LOGO
1830 The DIU driver will look for the 'video-mode' environment
1831 variable, and if defined, enable the DIU as a console during
1832 boot. See the documentation file README.video for a
1833 description of this variable.
1839 Define this to enable a custom keyboard support.
1840 This simply calls drv_keyboard_init() which must be
1841 defined in your board-specific files.
1842 The only board using this so far is RBC823.
1844 - LCD Support: CONFIG_LCD
1846 Define this to enable LCD support (for output to LCD
1847 display); also select one of the supported displays
1848 by defining one of these:
1852 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1854 CONFIG_NEC_NL6448AC33:
1856 NEC NL6448AC33-18. Active, color, single scan.
1858 CONFIG_NEC_NL6448BC20
1860 NEC NL6448BC20-08. 6.5", 640x480.
1861 Active, color, single scan.
1863 CONFIG_NEC_NL6448BC33_54
1865 NEC NL6448BC33-54. 10.4", 640x480.
1866 Active, color, single scan.
1870 Sharp 320x240. Active, color, single scan.
1871 It isn't 16x9, and I am not sure what it is.
1873 CONFIG_SHARP_LQ64D341
1875 Sharp LQ64D341 display, 640x480.
1876 Active, color, single scan.
1880 HLD1045 display, 640x480.
1881 Active, color, single scan.
1885 Optrex CBL50840-2 NF-FW 99 22 M5
1887 Hitachi LMG6912RPFC-00T
1891 320x240. Black & white.
1893 Normally display is black on white background; define
1894 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1896 CONFIG_LCD_ALIGNMENT
1898 Normally the LCD is page-aligned (typically 4KB). If this is
1899 defined then the LCD will be aligned to this value instead.
1900 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1901 here, since it is cheaper to change data cache settings on
1902 a per-section basis.
1904 CONFIG_CONSOLE_SCROLL_LINES
1906 When the console need to be scrolled, this is the number of
1907 lines to scroll by. It defaults to 1. Increasing this makes
1908 the console jump but can help speed up operation when scrolling
1913 Sometimes, for example if the display is mounted in portrait
1914 mode or even if it's mounted landscape but rotated by 180degree,
1915 we need to rotate our content of the display relative to the
1916 framebuffer, so that user can read the messages which are
1918 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1919 initialized with a given rotation from "vl_rot" out of
1920 "vidinfo_t" which is provided by the board specific code.
1921 The value for vl_rot is coded as following (matching to
1922 fbcon=rotate:<n> linux-kernel commandline):
1923 0 = no rotation respectively 0 degree
1924 1 = 90 degree rotation
1925 2 = 180 degree rotation
1926 3 = 270 degree rotation
1928 If CONFIG_LCD_ROTATION is not defined, the console will be
1929 initialized with 0degree rotation.
1933 Support drawing of RLE8-compressed bitmaps on the LCD.
1937 Enables an 'i2c edid' command which can read EDID
1938 information over I2C from an attached LCD display.
1940 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1942 If this option is set, the environment is checked for
1943 a variable "splashimage". If found, the usual display
1944 of logo, copyright and system information on the LCD
1945 is suppressed and the BMP image at the address
1946 specified in "splashimage" is loaded instead. The
1947 console is redirected to the "nulldev", too. This
1948 allows for a "silent" boot where a splash screen is
1949 loaded very quickly after power-on.
1951 CONFIG_SPLASHIMAGE_GUARD
1953 If this option is set, then U-Boot will prevent the environment
1954 variable "splashimage" from being set to a problematic address
1955 (see README.displaying-bmps).
1956 This option is useful for targets where, due to alignment
1957 restrictions, an improperly aligned BMP image will cause a data
1958 abort. If you think you will not have problems with unaligned
1959 accesses (for example because your toolchain prevents them)
1960 there is no need to set this option.
1962 CONFIG_SPLASH_SCREEN_ALIGN
1964 If this option is set the splash image can be freely positioned
1965 on the screen. Environment variable "splashpos" specifies the
1966 position as "x,y". If a positive number is given it is used as
1967 number of pixel from left/top. If a negative number is given it
1968 is used as number of pixel from right/bottom. You can also
1969 specify 'm' for centering the image.
1972 setenv splashpos m,m
1973 => image at center of screen
1975 setenv splashpos 30,20
1976 => image at x = 30 and y = 20
1978 setenv splashpos -10,m
1979 => vertically centered image
1980 at x = dspWidth - bmpWidth - 9
1982 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1984 If this option is set, additionally to standard BMP
1985 images, gzipped BMP images can be displayed via the
1986 splashscreen support or the bmp command.
1988 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1990 If this option is set, 8-bit RLE compressed BMP images
1991 can be displayed via the splashscreen support or the
1994 - Do compressing for memory range:
1997 If this option is set, it would use zlib deflate method
1998 to compress the specified memory at its best effort.
2000 - Compression support:
2003 Enabled by default to support gzip compressed images.
2007 If this option is set, support for bzip2 compressed
2008 images is included. If not, only uncompressed and gzip
2009 compressed images are supported.
2011 NOTE: the bzip2 algorithm requires a lot of RAM, so
2012 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2017 If this option is set, support for lzma compressed
2020 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2021 requires an amount of dynamic memory that is given by the
2024 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2026 Where lc and lp stand for, respectively, Literal context bits
2027 and Literal pos bits.
2029 This value is upper-bounded by 14MB in the worst case. Anyway,
2030 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2031 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2032 a very small buffer.
2034 Use the lzmainfo tool to determinate the lc and lp values and
2035 then calculate the amount of needed dynamic memory (ensuring
2036 the appropriate CONFIG_SYS_MALLOC_LEN value).
2040 If this option is set, support for LZO compressed images
2046 The address of PHY on MII bus.
2048 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2050 The clock frequency of the MII bus
2054 If this option is set, support for speed/duplex
2055 detection of gigabit PHY is included.
2057 CONFIG_PHY_RESET_DELAY
2059 Some PHY like Intel LXT971A need extra delay after
2060 reset before any MII register access is possible.
2061 For such PHY, set this option to the usec delay
2062 required. (minimum 300usec for LXT971A)
2064 CONFIG_PHY_CMD_DELAY (ppc4xx)
2066 Some PHY like Intel LXT971A need extra delay after
2067 command issued before MII status register can be read
2072 Define a default value for the IP address to use for
2073 the default Ethernet interface, in case this is not
2074 determined through e.g. bootp.
2075 (Environment variable "ipaddr")
2077 - Server IP address:
2080 Defines a default value for the IP address of a TFTP
2081 server to contact when using the "tftboot" command.
2082 (Environment variable "serverip")
2084 CONFIG_KEEP_SERVERADDR
2086 Keeps the server's MAC address, in the env 'serveraddr'
2087 for passing to bootargs (like Linux's netconsole option)
2089 - Gateway IP address:
2092 Defines a default value for the IP address of the
2093 default router where packets to other networks are
2095 (Environment variable "gatewayip")
2100 Defines a default value for the subnet mask (or
2101 routing prefix) which is used to determine if an IP
2102 address belongs to the local subnet or needs to be
2103 forwarded through a router.
2104 (Environment variable "netmask")
2106 - Multicast TFTP Mode:
2109 Defines whether you want to support multicast TFTP as per
2110 rfc-2090; for example to work with atftp. Lets lots of targets
2111 tftp down the same boot image concurrently. Note: the Ethernet
2112 driver in use must provide a function: mcast() to join/leave a
2115 - BOOTP Recovery Mode:
2116 CONFIG_BOOTP_RANDOM_DELAY
2118 If you have many targets in a network that try to
2119 boot using BOOTP, you may want to avoid that all
2120 systems send out BOOTP requests at precisely the same
2121 moment (which would happen for instance at recovery
2122 from a power failure, when all systems will try to
2123 boot, thus flooding the BOOTP server. Defining
2124 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2125 inserted before sending out BOOTP requests. The
2126 following delays are inserted then:
2128 1st BOOTP request: delay 0 ... 1 sec
2129 2nd BOOTP request: delay 0 ... 2 sec
2130 3rd BOOTP request: delay 0 ... 4 sec
2132 BOOTP requests: delay 0 ... 8 sec
2134 CONFIG_BOOTP_ID_CACHE_SIZE
2136 BOOTP packets are uniquely identified using a 32-bit ID. The
2137 server will copy the ID from client requests to responses and
2138 U-Boot will use this to determine if it is the destination of
2139 an incoming response. Some servers will check that addresses
2140 aren't in use before handing them out (usually using an ARP
2141 ping) and therefore take up to a few hundred milliseconds to
2142 respond. Network congestion may also influence the time it
2143 takes for a response to make it back to the client. If that
2144 time is too long, U-Boot will retransmit requests. In order
2145 to allow earlier responses to still be accepted after these
2146 retransmissions, U-Boot's BOOTP client keeps a small cache of
2147 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2148 cache. The default is to keep IDs for up to four outstanding
2149 requests. Increasing this will allow U-Boot to accept offers
2150 from a BOOTP client in networks with unusually high latency.
2152 - DHCP Advanced Options:
2153 You can fine tune the DHCP functionality by defining
2154 CONFIG_BOOTP_* symbols:
2156 CONFIG_BOOTP_SUBNETMASK
2157 CONFIG_BOOTP_GATEWAY
2158 CONFIG_BOOTP_HOSTNAME
2159 CONFIG_BOOTP_NISDOMAIN
2160 CONFIG_BOOTP_BOOTPATH
2161 CONFIG_BOOTP_BOOTFILESIZE
2164 CONFIG_BOOTP_SEND_HOSTNAME
2165 CONFIG_BOOTP_NTPSERVER
2166 CONFIG_BOOTP_TIMEOFFSET
2167 CONFIG_BOOTP_VENDOREX
2168 CONFIG_BOOTP_MAY_FAIL
2170 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2171 environment variable, not the BOOTP server.
2173 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2174 after the configured retry count, the call will fail
2175 instead of starting over. This can be used to fail over
2176 to Link-local IP address configuration if the DHCP server
2179 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2180 serverip from a DHCP server, it is possible that more
2181 than one DNS serverip is offered to the client.
2182 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2183 serverip will be stored in the additional environment
2184 variable "dnsip2". The first DNS serverip is always
2185 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2188 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2189 to do a dynamic update of a DNS server. To do this, they
2190 need the hostname of the DHCP requester.
2191 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2192 of the "hostname" environment variable is passed as
2193 option 12 to the DHCP server.
2195 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2197 A 32bit value in microseconds for a delay between
2198 receiving a "DHCP Offer" and sending the "DHCP Request".
2199 This fixes a problem with certain DHCP servers that don't
2200 respond 100% of the time to a "DHCP request". E.g. On an
2201 AT91RM9200 processor running at 180MHz, this delay needed
2202 to be *at least* 15,000 usec before a Windows Server 2003
2203 DHCP server would reply 100% of the time. I recommend at
2204 least 50,000 usec to be safe. The alternative is to hope
2205 that one of the retries will be successful but note that
2206 the DHCP timeout and retry process takes a longer than
2209 - Link-local IP address negotiation:
2210 Negotiate with other link-local clients on the local network
2211 for an address that doesn't require explicit configuration.
2212 This is especially useful if a DHCP server cannot be guaranteed
2213 to exist in all environments that the device must operate.
2215 See doc/README.link-local for more information.
2218 CONFIG_CDP_DEVICE_ID
2220 The device id used in CDP trigger frames.
2222 CONFIG_CDP_DEVICE_ID_PREFIX
2224 A two character string which is prefixed to the MAC address
2229 A printf format string which contains the ascii name of
2230 the port. Normally is set to "eth%d" which sets
2231 eth0 for the first Ethernet, eth1 for the second etc.
2233 CONFIG_CDP_CAPABILITIES
2235 A 32bit integer which indicates the device capabilities;
2236 0x00000010 for a normal host which does not forwards.
2240 An ascii string containing the version of the software.
2244 An ascii string containing the name of the platform.
2248 A 32bit integer sent on the trigger.
2250 CONFIG_CDP_POWER_CONSUMPTION
2252 A 16bit integer containing the power consumption of the
2253 device in .1 of milliwatts.
2255 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2257 A byte containing the id of the VLAN.
2259 - Status LED: CONFIG_STATUS_LED
2261 Several configurations allow to display the current
2262 status using a LED. For instance, the LED will blink
2263 fast while running U-Boot code, stop blinking as
2264 soon as a reply to a BOOTP request was received, and
2265 start blinking slow once the Linux kernel is running
2266 (supported by a status LED driver in the Linux
2267 kernel). Defining CONFIG_STATUS_LED enables this
2273 The status LED can be connected to a GPIO pin.
2274 In such cases, the gpio_led driver can be used as a
2275 status LED backend implementation. Define CONFIG_GPIO_LED
2276 to include the gpio_led driver in the U-Boot binary.
2278 CONFIG_GPIO_LED_INVERTED_TABLE
2279 Some GPIO connected LEDs may have inverted polarity in which
2280 case the GPIO high value corresponds to LED off state and
2281 GPIO low value corresponds to LED on state.
2282 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2283 with a list of GPIO LEDs that have inverted polarity.
2285 - CAN Support: CONFIG_CAN_DRIVER
2287 Defining CONFIG_CAN_DRIVER enables CAN driver support
2288 on those systems that support this (optional)
2289 feature, like the TQM8xxL modules.
2291 - I2C Support: CONFIG_SYS_I2C
2293 This enable the NEW i2c subsystem, and will allow you to use
2294 i2c commands at the u-boot command line (as long as you set
2295 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2296 based realtime clock chips or other i2c devices. See
2297 common/cmd_i2c.c for a description of the command line
2300 ported i2c driver to the new framework:
2301 - drivers/i2c/soft_i2c.c:
2302 - activate first bus with CONFIG_SYS_I2C_SOFT define
2303 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2304 for defining speed and slave address
2305 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2306 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2307 for defining speed and slave address
2308 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2309 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2310 for defining speed and slave address
2311 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2312 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2313 for defining speed and slave address
2315 - drivers/i2c/fsl_i2c.c:
2316 - activate i2c driver with CONFIG_SYS_I2C_FSL
2317 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2318 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2319 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2321 - If your board supports a second fsl i2c bus, define
2322 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2323 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2324 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2327 - drivers/i2c/tegra_i2c.c:
2328 - activate this driver with CONFIG_SYS_I2C_TEGRA
2329 - This driver adds 4 i2c buses with a fix speed from
2330 100000 and the slave addr 0!
2332 - drivers/i2c/ppc4xx_i2c.c
2333 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2334 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2335 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2337 - drivers/i2c/i2c_mxc.c
2338 - activate this driver with CONFIG_SYS_I2C_MXC
2339 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2340 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2341 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2342 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2343 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2344 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2345 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2346 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2347 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2348 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2349 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2350 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2351 If those defines are not set, default value is 100000
2352 for speed, and 0 for slave.
2354 - drivers/i2c/rcar_i2c.c:
2355 - activate this driver with CONFIG_SYS_I2C_RCAR
2356 - This driver adds 4 i2c buses
2358 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2359 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2360 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2361 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2362 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2363 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2364 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2365 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2366 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2368 - drivers/i2c/sh_i2c.c:
2369 - activate this driver with CONFIG_SYS_I2C_SH
2370 - This driver adds from 2 to 5 i2c buses
2372 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2373 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2374 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2375 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2376 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2377 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2378 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2379 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2380 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2381 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2382 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2383 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2384 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2386 - drivers/i2c/omap24xx_i2c.c
2387 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2388 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2389 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2390 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2391 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2392 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2393 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2394 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2395 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2396 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2397 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2399 - drivers/i2c/zynq_i2c.c
2400 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2401 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2402 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2404 - drivers/i2c/s3c24x0_i2c.c:
2405 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2406 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2407 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2408 with a fix speed from 100000 and the slave addr 0!
2410 - drivers/i2c/ihs_i2c.c
2411 - activate this driver with CONFIG_SYS_I2C_IHS
2412 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2413 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2414 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2415 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2416 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2417 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2418 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2419 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2420 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2421 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2422 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2423 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2424 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2425 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2426 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2427 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2428 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2429 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2430 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2431 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2432 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2436 CONFIG_SYS_NUM_I2C_BUSES
2437 Hold the number of i2c buses you want to use. If you
2438 don't use/have i2c muxes on your i2c bus, this
2439 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2442 CONFIG_SYS_I2C_DIRECT_BUS
2443 define this, if you don't use i2c muxes on your hardware.
2444 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2447 CONFIG_SYS_I2C_MAX_HOPS
2448 define how many muxes are maximal consecutively connected
2449 on one i2c bus. If you not use i2c muxes, omit this
2452 CONFIG_SYS_I2C_BUSES
2453 hold a list of buses you want to use, only used if
2454 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2455 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2456 CONFIG_SYS_NUM_I2C_BUSES = 9:
2458 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2459 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2460 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2461 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2462 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2463 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2464 {1, {I2C_NULL_HOP}}, \
2465 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2466 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2470 bus 0 on adapter 0 without a mux
2471 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2472 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2473 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2474 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2475 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2476 bus 6 on adapter 1 without a mux
2477 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2478 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2480 If you do not have i2c muxes on your board, omit this define.
2482 - Legacy I2C Support: CONFIG_HARD_I2C
2484 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2485 provides the following compelling advantages:
2487 - more than one i2c adapter is usable
2488 - approved multibus support
2489 - better i2c mux support
2491 ** Please consider updating your I2C driver now. **
2493 These enable legacy I2C serial bus commands. Defining
2494 CONFIG_HARD_I2C will include the appropriate I2C driver
2495 for the selected CPU.
2497 This will allow you to use i2c commands at the u-boot
2498 command line (as long as you set CONFIG_CMD_I2C in
2499 CONFIG_COMMANDS) and communicate with i2c based realtime
2500 clock chips. See common/cmd_i2c.c for a description of the
2501 command line interface.
2503 CONFIG_HARD_I2C selects a hardware I2C controller.
2505 There are several other quantities that must also be
2506 defined when you define CONFIG_HARD_I2C.
2508 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2509 to be the frequency (in Hz) at which you wish your i2c bus
2510 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2511 the CPU's i2c node address).
2513 Now, the u-boot i2c code for the mpc8xx
2514 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2515 and so its address should therefore be cleared to 0 (See,
2516 eg, MPC823e User's Manual p.16-473). So, set
2517 CONFIG_SYS_I2C_SLAVE to 0.
2519 CONFIG_SYS_I2C_INIT_MPC5XXX
2521 When a board is reset during an i2c bus transfer
2522 chips might think that the current transfer is still
2523 in progress. Reset the slave devices by sending start
2524 commands until the slave device responds.
2526 That's all that's required for CONFIG_HARD_I2C.
2528 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2529 then the following macros need to be defined (examples are
2530 from include/configs/lwmon.h):
2534 (Optional). Any commands necessary to enable the I2C
2535 controller or configure ports.
2537 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2541 (Only for MPC8260 CPU). The I/O port to use (the code
2542 assumes both bits are on the same port). Valid values
2543 are 0..3 for ports A..D.
2547 The code necessary to make the I2C data line active
2548 (driven). If the data line is open collector, this
2551 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2555 The code necessary to make the I2C data line tri-stated
2556 (inactive). If the data line is open collector, this
2559 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2563 Code that returns true if the I2C data line is high,
2566 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2570 If <bit> is true, sets the I2C data line high. If it
2571 is false, it clears it (low).
2573 eg: #define I2C_SDA(bit) \
2574 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2575 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2579 If <bit> is true, sets the I2C clock line high. If it
2580 is false, it clears it (low).
2582 eg: #define I2C_SCL(bit) \
2583 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2584 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2588 This delay is invoked four times per clock cycle so this
2589 controls the rate of data transfer. The data rate thus
2590 is 1 / (I2C_DELAY * 4). Often defined to be something
2593 #define I2C_DELAY udelay(2)
2595 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2597 If your arch supports the generic GPIO framework (asm/gpio.h),
2598 then you may alternatively define the two GPIOs that are to be
2599 used as SCL / SDA. Any of the previous I2C_xxx macros will
2600 have GPIO-based defaults assigned to them as appropriate.
2602 You should define these to the GPIO value as given directly to
2603 the generic GPIO functions.
2605 CONFIG_SYS_I2C_INIT_BOARD
2607 When a board is reset during an i2c bus transfer
2608 chips might think that the current transfer is still
2609 in progress. On some boards it is possible to access
2610 the i2c SCLK line directly, either by using the
2611 processor pin as a GPIO or by having a second pin
2612 connected to the bus. If this option is defined a
2613 custom i2c_init_board() routine in boards/xxx/board.c
2614 is run early in the boot sequence.
2616 CONFIG_SYS_I2C_BOARD_LATE_INIT
2618 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2619 defined a custom i2c_board_late_init() routine in
2620 boards/xxx/board.c is run AFTER the operations in i2c_init()
2621 is completed. This callpoint can be used to unreset i2c bus
2622 using CPU i2c controller register accesses for CPUs whose i2c
2623 controller provide such a method. It is called at the end of
2624 i2c_init() to allow i2c_init operations to setup the i2c bus
2625 controller on the CPU (e.g. setting bus speed & slave address).
2627 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2629 This option enables configuration of bi_iic_fast[] flags
2630 in u-boot bd_info structure based on u-boot environment
2631 variable "i2cfast". (see also i2cfast)
2633 CONFIG_I2C_MULTI_BUS
2635 This option allows the use of multiple I2C buses, each of which
2636 must have a controller. At any point in time, only one bus is
2637 active. To switch to a different bus, use the 'i2c dev' command.
2638 Note that bus numbering is zero-based.
2640 CONFIG_SYS_I2C_NOPROBES
2642 This option specifies a list of I2C devices that will be skipped
2643 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2644 is set, specify a list of bus-device pairs. Otherwise, specify
2645 a 1D array of device addresses
2648 #undef CONFIG_I2C_MULTI_BUS
2649 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2651 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2653 #define CONFIG_I2C_MULTI_BUS
2654 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2656 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2658 CONFIG_SYS_SPD_BUS_NUM
2660 If defined, then this indicates the I2C bus number for DDR SPD.
2661 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2663 CONFIG_SYS_RTC_BUS_NUM
2665 If defined, then this indicates the I2C bus number for the RTC.
2666 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2668 CONFIG_SYS_DTT_BUS_NUM
2670 If defined, then this indicates the I2C bus number for the DTT.
2671 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2673 CONFIG_SYS_I2C_DTT_ADDR:
2675 If defined, specifies the I2C address of the DTT device.
2676 If not defined, then U-Boot uses predefined value for
2677 specified DTT device.
2679 CONFIG_SOFT_I2C_READ_REPEATED_START
2681 defining this will force the i2c_read() function in
2682 the soft_i2c driver to perform an I2C repeated start
2683 between writing the address pointer and reading the
2684 data. If this define is omitted the default behaviour
2685 of doing a stop-start sequence will be used. Most I2C
2686 devices can use either method, but some require one or
2689 - SPI Support: CONFIG_SPI
2691 Enables SPI driver (so far only tested with
2692 SPI EEPROM, also an instance works with Crystal A/D and
2693 D/As on the SACSng board)
2697 Enables the driver for SPI controller on SuperH. Currently
2698 only SH7757 is supported.
2702 Enables extended (16-bit) SPI EEPROM addressing.
2703 (symmetrical to CONFIG_I2C_X)
2707 Enables a software (bit-bang) SPI driver rather than
2708 using hardware support. This is a general purpose
2709 driver that only requires three general I/O port pins
2710 (two outputs, one input) to function. If this is
2711 defined, the board configuration must define several
2712 SPI configuration items (port pins to use, etc). For
2713 an example, see include/configs/sacsng.h.
2717 Enables a hardware SPI driver for general-purpose reads
2718 and writes. As with CONFIG_SOFT_SPI, the board configuration
2719 must define a list of chip-select function pointers.
2720 Currently supported on some MPC8xxx processors. For an
2721 example, see include/configs/mpc8349emds.h.
2725 Enables the driver for the SPI controllers on i.MX and MXC
2726 SoCs. Currently i.MX31/35/51 are supported.
2728 CONFIG_SYS_SPI_MXC_WAIT
2729 Timeout for waiting until spi transfer completed.
2730 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2732 - FPGA Support: CONFIG_FPGA
2734 Enables FPGA subsystem.
2736 CONFIG_FPGA_<vendor>
2738 Enables support for specific chip vendors.
2741 CONFIG_FPGA_<family>
2743 Enables support for FPGA family.
2744 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2748 Specify the number of FPGA devices to support.
2750 CONFIG_CMD_FPGA_LOADMK
2752 Enable support for fpga loadmk command
2754 CONFIG_CMD_FPGA_LOADP
2756 Enable support for fpga loadp command - load partial bitstream
2758 CONFIG_CMD_FPGA_LOADBP
2760 Enable support for fpga loadbp command - load partial bitstream
2763 CONFIG_SYS_FPGA_PROG_FEEDBACK
2765 Enable printing of hash marks during FPGA configuration.
2767 CONFIG_SYS_FPGA_CHECK_BUSY
2769 Enable checks on FPGA configuration interface busy
2770 status by the configuration function. This option
2771 will require a board or device specific function to
2776 If defined, a function that provides delays in the FPGA
2777 configuration driver.
2779 CONFIG_SYS_FPGA_CHECK_CTRLC
2780 Allow Control-C to interrupt FPGA configuration
2782 CONFIG_SYS_FPGA_CHECK_ERROR
2784 Check for configuration errors during FPGA bitfile
2785 loading. For example, abort during Virtex II
2786 configuration if the INIT_B line goes low (which
2787 indicated a CRC error).
2789 CONFIG_SYS_FPGA_WAIT_INIT
2791 Maximum time to wait for the INIT_B line to de-assert
2792 after PROB_B has been de-asserted during a Virtex II
2793 FPGA configuration sequence. The default time is 500
2796 CONFIG_SYS_FPGA_WAIT_BUSY
2798 Maximum time to wait for BUSY to de-assert during
2799 Virtex II FPGA configuration. The default is 5 ms.
2801 CONFIG_SYS_FPGA_WAIT_CONFIG
2803 Time to wait after FPGA configuration. The default is
2806 - Configuration Management:
2809 Some SoCs need special image types (e.g. U-Boot binary
2810 with a special header) as build targets. By defining
2811 CONFIG_BUILD_TARGET in the SoC / board header, this
2812 special image will be automatically built upon calling
2817 If defined, this string will be added to the U-Boot
2818 version information (U_BOOT_VERSION)
2820 - Vendor Parameter Protection:
2822 U-Boot considers the values of the environment
2823 variables "serial#" (Board Serial Number) and
2824 "ethaddr" (Ethernet Address) to be parameters that
2825 are set once by the board vendor / manufacturer, and
2826 protects these variables from casual modification by
2827 the user. Once set, these variables are read-only,
2828 and write or delete attempts are rejected. You can
2829 change this behaviour:
2831 If CONFIG_ENV_OVERWRITE is #defined in your config
2832 file, the write protection for vendor parameters is
2833 completely disabled. Anybody can change or delete
2836 Alternatively, if you define _both_ an ethaddr in the
2837 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2838 Ethernet address is installed in the environment,
2839 which can be changed exactly ONCE by the user. [The
2840 serial# is unaffected by this, i. e. it remains
2843 The same can be accomplished in a more flexible way
2844 for any variable by configuring the type of access
2845 to allow for those variables in the ".flags" variable
2846 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2851 Define this variable to enable the reservation of
2852 "protected RAM", i. e. RAM which is not overwritten
2853 by U-Boot. Define CONFIG_PRAM to hold the number of
2854 kB you want to reserve for pRAM. You can overwrite
2855 this default value by defining an environment
2856 variable "pram" to the number of kB you want to
2857 reserve. Note that the board info structure will
2858 still show the full amount of RAM. If pRAM is
2859 reserved, a new environment variable "mem" will
2860 automatically be defined to hold the amount of
2861 remaining RAM in a form that can be passed as boot
2862 argument to Linux, for instance like that:
2864 setenv bootargs ... mem=\${mem}
2867 This way you can tell Linux not to use this memory,
2868 either, which results in a memory region that will
2869 not be affected by reboots.
2871 *WARNING* If your board configuration uses automatic
2872 detection of the RAM size, you must make sure that
2873 this memory test is non-destructive. So far, the
2874 following board configurations are known to be
2877 IVMS8, IVML24, SPD8xx, TQM8xxL,
2878 HERMES, IP860, RPXlite, LWMON,
2881 - Access to physical memory region (> 4GB)
2882 Some basic support is provided for operations on memory not
2883 normally accessible to U-Boot - e.g. some architectures
2884 support access to more than 4GB of memory on 32-bit
2885 machines using physical address extension or similar.
2886 Define CONFIG_PHYSMEM to access this basic support, which
2887 currently only supports clearing the memory.
2892 Define this variable to stop the system in case of a
2893 fatal error, so that you have to reset it manually.
2894 This is probably NOT a good idea for an embedded
2895 system where you want the system to reboot
2896 automatically as fast as possible, but it may be
2897 useful during development since you can try to debug
2898 the conditions that lead to the situation.
2900 CONFIG_NET_RETRY_COUNT
2902 This variable defines the number of retries for
2903 network operations like ARP, RARP, TFTP, or BOOTP
2904 before giving up the operation. If not defined, a
2905 default value of 5 is used.
2909 Timeout waiting for an ARP reply in milliseconds.
2913 Timeout in milliseconds used in NFS protocol.
2914 If you encounter "ERROR: Cannot umount" in nfs command,
2915 try longer timeout such as
2916 #define CONFIG_NFS_TIMEOUT 10000UL
2918 - Command Interpreter:
2919 CONFIG_AUTO_COMPLETE
2921 Enable auto completion of commands using TAB.
2923 CONFIG_SYS_PROMPT_HUSH_PS2
2925 This defines the secondary prompt string, which is
2926 printed when the command interpreter needs more input
2927 to complete a command. Usually "> ".
2931 In the current implementation, the local variables
2932 space and global environment variables space are
2933 separated. Local variables are those you define by
2934 simply typing `name=value'. To access a local
2935 variable later on, you have write `$name' or
2936 `${name}'; to execute the contents of a variable
2937 directly type `$name' at the command prompt.
2939 Global environment variables are those you use
2940 setenv/printenv to work with. To run a command stored
2941 in such a variable, you need to use the run command,
2942 and you must not use the '$' sign to access them.
2944 To store commands and special characters in a
2945 variable, please use double quotation marks
2946 surrounding the whole text of the variable, instead
2947 of the backslashes before semicolons and special
2950 - Command Line Editing and History:
2951 CONFIG_CMDLINE_EDITING
2953 Enable editing and History functions for interactive
2954 command line input operations
2956 - Default Environment:
2957 CONFIG_EXTRA_ENV_SETTINGS
2959 Define this to contain any number of null terminated
2960 strings (variable = value pairs) that will be part of
2961 the default environment compiled into the boot image.
2963 For example, place something like this in your
2964 board's config file:
2966 #define CONFIG_EXTRA_ENV_SETTINGS \
2970 Warning: This method is based on knowledge about the
2971 internal format how the environment is stored by the
2972 U-Boot code. This is NOT an official, exported
2973 interface! Although it is unlikely that this format
2974 will change soon, there is no guarantee either.
2975 You better know what you are doing here.
2977 Note: overly (ab)use of the default environment is
2978 discouraged. Make sure to check other ways to preset
2979 the environment like the "source" command or the
2982 CONFIG_ENV_VARS_UBOOT_CONFIG
2984 Define this in order to add variables describing the
2985 U-Boot build configuration to the default environment.
2986 These will be named arch, cpu, board, vendor, and soc.
2988 Enabling this option will cause the following to be defined:
2996 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2998 Define this in order to add variables describing certain
2999 run-time determined information about the hardware to the
3000 environment. These will be named board_name, board_rev.
3002 CONFIG_DELAY_ENVIRONMENT
3004 Normally the environment is loaded when the board is
3005 initialised so that it is available to U-Boot. This inhibits
3006 that so that the environment is not available until
3007 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3008 this is instead controlled by the value of
3009 /config/load-environment.
3011 - Parallel Flash support:
3014 Traditionally U-boot was run on systems with parallel NOR
3015 flash. This option is used to disable support for parallel NOR
3016 flash. This option should be defined if the board does not have
3019 If this option is not defined one of the generic flash drivers
3020 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3021 selected or the board must provide an implementation of the
3022 flash API (see include/flash.h).
3024 - DataFlash Support:
3025 CONFIG_HAS_DATAFLASH
3027 Defining this option enables DataFlash features and
3028 allows to read/write in Dataflash via the standard
3031 - Serial Flash support
3034 Defining this option enables SPI flash commands
3035 'sf probe/read/write/erase/update'.
3037 Usage requires an initial 'probe' to define the serial
3038 flash parameters, followed by read/write/erase/update
3041 The following defaults may be provided by the platform
3042 to handle the common case when only a single serial
3043 flash is present on the system.
3045 CONFIG_SF_DEFAULT_BUS Bus identifier
3046 CONFIG_SF_DEFAULT_CS Chip-select
3047 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3048 CONFIG_SF_DEFAULT_SPEED in Hz
3052 Define this option to include a destructive SPI flash
3055 CONFIG_SF_DUAL_FLASH Dual flash memories
3057 Define this option to use dual flash support where two flash
3058 memories can be connected with a given cs line.
3059 Currently Xilinx Zynq qspi supports these type of connections.
3061 - SystemACE Support:
3064 Adding this option adds support for Xilinx SystemACE
3065 chips attached via some sort of local bus. The address
3066 of the chip must also be defined in the
3067 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3069 #define CONFIG_SYSTEMACE
3070 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3072 When SystemACE support is added, the "ace" device type
3073 becomes available to the fat commands, i.e. fatls.
3075 - TFTP Fixed UDP Port:
3078 If this is defined, the environment variable tftpsrcp
3079 is used to supply the TFTP UDP source port value.
3080 If tftpsrcp isn't defined, the normal pseudo-random port
3081 number generator is used.
3083 Also, the environment variable tftpdstp is used to supply
3084 the TFTP UDP destination port value. If tftpdstp isn't
3085 defined, the normal port 69 is used.
3087 The purpose for tftpsrcp is to allow a TFTP server to
3088 blindly start the TFTP transfer using the pre-configured
3089 target IP address and UDP port. This has the effect of
3090 "punching through" the (Windows XP) firewall, allowing
3091 the remainder of the TFTP transfer to proceed normally.
3092 A better solution is to properly configure the firewall,
3093 but sometimes that is not allowed.
3098 This enables a generic 'hash' command which can produce
3099 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3103 Enable the hash verify command (hash -v). This adds to code
3106 CONFIG_SHA1 - This option enables support of hashing using SHA1
3107 algorithm. The hash is calculated in software.
3108 CONFIG_SHA256 - This option enables support of hashing using
3109 SHA256 algorithm. The hash is calculated in software.
3110 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3111 for SHA1/SHA256 hashing.
3112 This affects the 'hash' command and also the
3113 hash_lookup_algo() function.
3114 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3115 hardware-acceleration for SHA1/SHA256 progressive hashing.
3116 Data can be streamed in a block at a time and the hashing
3117 is performed in hardware.
3119 Note: There is also a sha1sum command, which should perhaps
3120 be deprecated in favour of 'hash sha1'.
3122 - Freescale i.MX specific commands:
3123 CONFIG_CMD_HDMIDETECT
3124 This enables 'hdmidet' command which returns true if an
3125 HDMI monitor is detected. This command is i.MX 6 specific.
3128 This enables the 'bmode' (bootmode) command for forcing
3129 a boot from specific media.
3131 This is useful for forcing the ROM's usb downloader to
3132 activate upon a watchdog reset which is nice when iterating
3133 on U-Boot. Using the reset button or running bmode normal
3134 will set it back to normal. This command currently
3135 supports i.MX53 and i.MX6.
3140 This enables the RSA algorithm used for FIT image verification
3141 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3143 The Modular Exponentiation algorithm in RSA is implemented using
3144 driver model. So CONFIG_DM needs to be enabled by default for this
3145 library to function.
3147 The signing part is build into mkimage regardless of this
3148 option. The software based modular exponentiation is built into
3149 mkimage irrespective of this option.
3151 - bootcount support:
3152 CONFIG_BOOTCOUNT_LIMIT
3154 This enables the bootcounter support, see:
3155 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3158 enable special bootcounter support on at91sam9xe based boards.
3160 enable special bootcounter support on blackfin based boards.
3162 enable special bootcounter support on da850 based boards.
3163 CONFIG_BOOTCOUNT_RAM
3164 enable support for the bootcounter in RAM
3165 CONFIG_BOOTCOUNT_I2C
3166 enable support for the bootcounter on an i2c (like RTC) device.
3167 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3168 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3170 CONFIG_BOOTCOUNT_ALEN = address len
3172 - Show boot progress:
3173 CONFIG_SHOW_BOOT_PROGRESS
3175 Defining this option allows to add some board-
3176 specific code (calling a user-provided function
3177 "show_boot_progress(int)") that enables you to show
3178 the system's boot progress on some display (for
3179 example, some LED's) on your board. At the moment,
3180 the following checkpoints are implemented:
3183 Legacy uImage format:
3186 1 common/cmd_bootm.c before attempting to boot an image
3187 -1 common/cmd_bootm.c Image header has bad magic number
3188 2 common/cmd_bootm.c Image header has correct magic number
3189 -2 common/cmd_bootm.c Image header has bad checksum
3190 3 common/cmd_bootm.c Image header has correct checksum
3191 -3 common/cmd_bootm.c Image data has bad checksum
3192 4 common/cmd_bootm.c Image data has correct checksum
3193 -4 common/cmd_bootm.c Image is for unsupported architecture
3194 5 common/cmd_bootm.c Architecture check OK
3195 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3196 6 common/cmd_bootm.c Image Type check OK
3197 -6 common/cmd_bootm.c gunzip uncompression error
3198 -7 common/cmd_bootm.c Unimplemented compression type
3199 7 common/cmd_bootm.c Uncompression OK
3200 8 common/cmd_bootm.c No uncompress/copy overwrite error
3201 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3203 9 common/image.c Start initial ramdisk verification
3204 -10 common/image.c Ramdisk header has bad magic number
3205 -11 common/image.c Ramdisk header has bad checksum
3206 10 common/image.c Ramdisk header is OK
3207 -12 common/image.c Ramdisk data has bad checksum
3208 11 common/image.c Ramdisk data has correct checksum
3209 12 common/image.c Ramdisk verification complete, start loading
3210 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3211 13 common/image.c Start multifile image verification
3212 14 common/image.c No initial ramdisk, no multifile, continue.
3214 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3216 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3217 -31 post/post.c POST test failed, detected by post_output_backlog()
3218 -32 post/post.c POST test failed, detected by post_run_single()
3220 34 common/cmd_doc.c before loading a Image from a DOC device
3221 -35 common/cmd_doc.c Bad usage of "doc" command
3222 35 common/cmd_doc.c correct usage of "doc" command
3223 -36 common/cmd_doc.c No boot device
3224 36 common/cmd_doc.c correct boot device
3225 -37 common/cmd_doc.c Unknown Chip ID on boot device
3226 37 common/cmd_doc.c correct chip ID found, device available
3227 -38 common/cmd_doc.c Read Error on boot device
3228 38 common/cmd_doc.c reading Image header from DOC device OK
3229 -39 common/cmd_doc.c Image header has bad magic number
3230 39 common/cmd_doc.c Image header has correct magic number
3231 -40 common/cmd_doc.c Error reading Image from DOC device
3232 40 common/cmd_doc.c Image header has correct magic number
3233 41 common/cmd_ide.c before loading a Image from a IDE device
3234 -42 common/cmd_ide.c Bad usage of "ide" command
3235 42 common/cmd_ide.c correct usage of "ide" command
3236 -43 common/cmd_ide.c No boot device
3237 43 common/cmd_ide.c boot device found
3238 -44 common/cmd_ide.c Device not available
3239 44 common/cmd_ide.c Device available
3240 -45 common/cmd_ide.c wrong partition selected
3241 45 common/cmd_ide.c partition selected
3242 -46 common/cmd_ide.c Unknown partition table
3243 46 common/cmd_ide.c valid partition table found
3244 -47 common/cmd_ide.c Invalid partition type
3245 47 common/cmd_ide.c correct partition type
3246 -48 common/cmd_ide.c Error reading Image Header on boot device
3247 48 common/cmd_ide.c reading Image Header from IDE device OK
3248 -49 common/cmd_ide.c Image header has bad magic number
3249 49 common/cmd_ide.c Image header has correct magic number
3250 -50 common/cmd_ide.c Image header has bad checksum
3251 50 common/cmd_ide.c Image header has correct checksum
3252 -51 common/cmd_ide.c Error reading Image from IDE device
3253 51 common/cmd_ide.c reading Image from IDE device OK
3254 52 common/cmd_nand.c before loading a Image from a NAND device
3255 -53 common/cmd_nand.c Bad usage of "nand" command
3256 53 common/cmd_nand.c correct usage of "nand" command
3257 -54 common/cmd_nand.c No boot device
3258 54 common/cmd_nand.c boot device found
3259 -55 common/cmd_nand.c Unknown Chip ID on boot device
3260 55 common/cmd_nand.c correct chip ID found, device available
3261 -56 common/cmd_nand.c Error reading Image Header on boot device
3262 56 common/cmd_nand.c reading Image Header from NAND device OK
3263 -57 common/cmd_nand.c Image header has bad magic number
3264 57 common/cmd_nand.c Image header has correct magic number
3265 -58 common/cmd_nand.c Error reading Image from NAND device
3266 58 common/cmd_nand.c reading Image from NAND device OK
3268 -60 common/env_common.c Environment has a bad CRC, using default
3270 64 net/eth.c starting with Ethernet configuration.
3271 -64 net/eth.c no Ethernet found.
3272 65 net/eth.c Ethernet found.
3274 -80 common/cmd_net.c usage wrong
3275 80 common/cmd_net.c before calling net_loop()
3276 -81 common/cmd_net.c some error in net_loop() occurred
3277 81 common/cmd_net.c net_loop() back without error
3278 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3279 82 common/cmd_net.c trying automatic boot
3280 83 common/cmd_net.c running "source" command
3281 -83 common/cmd_net.c some error in automatic boot or "source" command
3282 84 common/cmd_net.c end without errors
3287 100 common/cmd_bootm.c Kernel FIT Image has correct format
3288 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3289 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3290 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3291 102 common/cmd_bootm.c Kernel unit name specified
3292 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3293 103 common/cmd_bootm.c Found configuration node
3294 104 common/cmd_bootm.c Got kernel subimage node offset
3295 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3296 105 common/cmd_bootm.c Kernel subimage hash verification OK
3297 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3298 106 common/cmd_bootm.c Architecture check OK
3299 -106 common/cmd_bootm.c Kernel subimage has wrong type
3300 107 common/cmd_bootm.c Kernel subimage type OK
3301 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3302 108 common/cmd_bootm.c Got kernel subimage data/size
3303 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3304 -109 common/cmd_bootm.c Can't get kernel subimage type
3305 -110 common/cmd_bootm.c Can't get kernel subimage comp
3306 -111 common/cmd_bootm.c Can't get kernel subimage os
3307 -112 common/cmd_bootm.c Can't get kernel subimage load address
3308 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3310 120 common/image.c Start initial ramdisk verification
3311 -120 common/image.c Ramdisk FIT image has incorrect format
3312 121 common/image.c Ramdisk FIT image has correct format
3313 122 common/image.c No ramdisk subimage unit name, using configuration
3314 -122 common/image.c Can't get configuration for ramdisk subimage
3315 123 common/image.c Ramdisk unit name specified
3316 -124 common/image.c Can't get ramdisk subimage node offset
3317 125 common/image.c Got ramdisk subimage node offset
3318 -125 common/image.c Ramdisk subimage hash verification failed
3319 126 common/image.c Ramdisk subimage hash verification OK
3320 -126 common/image.c Ramdisk subimage for unsupported architecture
3321 127 common/image.c Architecture check OK
3322 -127 common/image.c Can't get ramdisk subimage data/size
3323 128 common/image.c Got ramdisk subimage data/size
3324 129 common/image.c Can't get ramdisk load address
3325 -129 common/image.c Got ramdisk load address
3327 -130 common/cmd_doc.c Incorrect FIT image format
3328 131 common/cmd_doc.c FIT image format OK
3330 -140 common/cmd_ide.c Incorrect FIT image format
3331 141 common/cmd_ide.c FIT image format OK
3333 -150 common/cmd_nand.c Incorrect FIT image format
3334 151 common/cmd_nand.c FIT image format OK
3336 - legacy image format:
3337 CONFIG_IMAGE_FORMAT_LEGACY
3338 enables the legacy image format support in U-Boot.
3341 enabled if CONFIG_FIT_SIGNATURE is not defined.
3343 CONFIG_DISABLE_IMAGE_LEGACY
3344 disable the legacy image format
3346 This define is introduced, as the legacy image format is
3347 enabled per default for backward compatibility.
3349 - FIT image support:
3351 Enable support for the FIT uImage format.
3353 CONFIG_FIT_BEST_MATCH
3354 When no configuration is explicitly selected, default to the
3355 one whose fdt's compatibility field best matches that of
3356 U-Boot itself. A match is considered "best" if it matches the
3357 most specific compatibility entry of U-Boot's fdt's root node.
3358 The order of entries in the configuration's fdt is ignored.
3360 CONFIG_FIT_SIGNATURE
3361 This option enables signature verification of FIT uImages,
3362 using a hash signed and verified using RSA. If
3363 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3364 hashing is available using hardware, RSA library will use it.
3365 See doc/uImage.FIT/signature.txt for more details.
3367 WARNING: When relying on signed FIT images with required
3368 signature check the legacy image format is default
3369 disabled. If a board need legacy image format support
3370 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3372 CONFIG_FIT_DISABLE_SHA256
3373 Supporting SHA256 hashes has quite an impact on binary size.
3374 For constrained systems sha256 hash support can be disabled
3377 - Standalone program support:
3378 CONFIG_STANDALONE_LOAD_ADDR
3380 This option defines a board specific value for the
3381 address where standalone program gets loaded, thus
3382 overwriting the architecture dependent default
3385 - Frame Buffer Address:
3388 Define CONFIG_FB_ADDR if you want to use specific
3389 address for frame buffer. This is typically the case
3390 when using a graphics controller has separate video
3391 memory. U-Boot will then place the frame buffer at
3392 the given address instead of dynamically reserving it
3393 in system RAM by calling lcd_setmem(), which grabs
3394 the memory for the frame buffer depending on the
3395 configured panel size.
3397 Please see board_init_f function.
3399 - Automatic software updates via TFTP server
3401 CONFIG_UPDATE_TFTP_CNT_MAX
3402 CONFIG_UPDATE_TFTP_MSEC_MAX
3404 These options enable and control the auto-update feature;
3405 for a more detailed description refer to doc/README.update.
3407 - MTD Support (mtdparts command, UBI support)
3410 Adds the MTD device infrastructure from the Linux kernel.
3411 Needed for mtdparts command support.
3413 CONFIG_MTD_PARTITIONS
3415 Adds the MTD partitioning infrastructure from the Linux
3416 kernel. Needed for UBI support.
3421 Adds commands for interacting with MTD partitions formatted
3422 with the UBI flash translation layer
3424 Requires also defining CONFIG_RBTREE
3426 CONFIG_UBI_SILENCE_MSG
3428 Make the verbose messages from UBI stop printing. This leaves
3429 warnings and errors enabled.
3432 CONFIG_MTD_UBI_WL_THRESHOLD
3433 This parameter defines the maximum difference between the highest
3434 erase counter value and the lowest erase counter value of eraseblocks
3435 of UBI devices. When this threshold is exceeded, UBI starts performing
3436 wear leveling by means of moving data from eraseblock with low erase
3437 counter to eraseblocks with high erase counter.
3439 The default value should be OK for SLC NAND flashes, NOR flashes and
3440 other flashes which have eraseblock life-cycle 100000 or more.
3441 However, in case of MLC NAND flashes which typically have eraseblock
3442 life-cycle less than 10000, the threshold should be lessened (e.g.,
3443 to 128 or 256, although it does not have to be power of 2).
3447 CONFIG_MTD_UBI_BEB_LIMIT
3448 This option specifies the maximum bad physical eraseblocks UBI
3449 expects on the MTD device (per 1024 eraseblocks). If the
3450 underlying flash does not admit of bad eraseblocks (e.g. NOR
3451 flash), this value is ignored.
3453 NAND datasheets often specify the minimum and maximum NVM
3454 (Number of Valid Blocks) for the flashes' endurance lifetime.
3455 The maximum expected bad eraseblocks per 1024 eraseblocks
3456 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3457 which gives 20 for most NANDs (MaxNVB is basically the total
3458 count of eraseblocks on the chip).
3460 To put it differently, if this value is 20, UBI will try to
3461 reserve about 1.9% of physical eraseblocks for bad blocks
3462 handling. And that will be 1.9% of eraseblocks on the entire
3463 NAND chip, not just the MTD partition UBI attaches. This means
3464 that if you have, say, a NAND flash chip admits maximum 40 bad
3465 eraseblocks, and it is split on two MTD partitions of the same
3466 size, UBI will reserve 40 eraseblocks when attaching a
3471 CONFIG_MTD_UBI_FASTMAP
3472 Fastmap is a mechanism which allows attaching an UBI device
3473 in nearly constant time. Instead of scanning the whole MTD device it
3474 only has to locate a checkpoint (called fastmap) on the device.
3475 The on-flash fastmap contains all information needed to attach
3476 the device. Using fastmap makes only sense on large devices where
3477 attaching by scanning takes long. UBI will not automatically install
3478 a fastmap on old images, but you can set the UBI parameter
3479 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3480 that fastmap-enabled images are still usable with UBI implementations
3481 without fastmap support. On typical flash devices the whole fastmap
3482 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3484 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3485 Set this parameter to enable fastmap automatically on images
3489 CONFIG_MTD_UBI_FM_DEBUG
3490 Enable UBI fastmap debug
3496 Adds commands for interacting with UBI volumes formatted as
3497 UBIFS. UBIFS is read-only in u-boot.
3499 Requires UBI support as well as CONFIG_LZO
3501 CONFIG_UBIFS_SILENCE_MSG
3503 Make the verbose messages from UBIFS stop printing. This leaves
3504 warnings and errors enabled.
3508 Enable building of SPL globally.
3511 LDSCRIPT for linking the SPL binary.
3513 CONFIG_SPL_MAX_FOOTPRINT
3514 Maximum size in memory allocated to the SPL, BSS included.
3515 When defined, the linker checks that the actual memory
3516 used by SPL from _start to __bss_end does not exceed it.
3517 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3518 must not be both defined at the same time.
3521 Maximum size of the SPL image (text, data, rodata, and
3522 linker lists sections), BSS excluded.
3523 When defined, the linker checks that the actual size does
3526 CONFIG_SPL_TEXT_BASE
3527 TEXT_BASE for linking the SPL binary.
3529 CONFIG_SPL_RELOC_TEXT_BASE
3530 Address to relocate to. If unspecified, this is equal to
3531 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3533 CONFIG_SPL_BSS_START_ADDR
3534 Link address for the BSS within the SPL binary.
3536 CONFIG_SPL_BSS_MAX_SIZE
3537 Maximum size in memory allocated to the SPL BSS.
3538 When defined, the linker checks that the actual memory used
3539 by SPL from __bss_start to __bss_end does not exceed it.
3540 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3541 must not be both defined at the same time.
3544 Adress of the start of the stack SPL will use
3546 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3547 When defined, SPL will panic() if the image it has
3548 loaded does not have a signature.
3549 Defining this is useful when code which loads images
3550 in SPL cannot guarantee that absolutely all read errors
3552 An example is the LPC32XX MLC NAND driver, which will
3553 consider that a completely unreadable NAND block is bad,
3554 and thus should be skipped silently.
3556 CONFIG_SPL_RELOC_STACK
3557 Adress of the start of the stack SPL will use after
3558 relocation. If unspecified, this is equal to
3561 CONFIG_SYS_SPL_MALLOC_START
3562 Starting address of the malloc pool used in SPL.
3563 When this option is set the full malloc is used in SPL and
3564 it is set up by spl_init() and before that, the simple malloc()
3565 can be used if CONFIG_SYS_MALLOC_F is defined.
3567 CONFIG_SYS_SPL_MALLOC_SIZE
3568 The size of the malloc pool used in SPL.
3570 CONFIG_SPL_FRAMEWORK
3571 Enable the SPL framework under common/. This framework
3572 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3573 NAND loading of the Linux Kernel.
3576 Enable booting directly to an OS from SPL.
3577 See also: doc/README.falcon
3579 CONFIG_SPL_DISPLAY_PRINT
3580 For ARM, enable an optional function to print more information
3581 about the running system.
3583 CONFIG_SPL_INIT_MINIMAL
3584 Arch init code should be built for a very small image
3586 CONFIG_SPL_LIBCOMMON_SUPPORT
3587 Support for common/libcommon.o in SPL binary
3589 CONFIG_SPL_LIBDISK_SUPPORT
3590 Support for disk/libdisk.o in SPL binary
3592 CONFIG_SPL_I2C_SUPPORT
3593 Support for drivers/i2c/libi2c.o in SPL binary
3595 CONFIG_SPL_GPIO_SUPPORT
3596 Support for drivers/gpio/libgpio.o in SPL binary
3598 CONFIG_SPL_MMC_SUPPORT
3599 Support for drivers/mmc/libmmc.o in SPL binary
3601 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3602 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3603 Address and partition on the MMC to load U-Boot from
3604 when the MMC is being used in raw mode.
3606 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3607 Partition on the MMC to load U-Boot from when the MMC is being
3610 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3611 Sector to load kernel uImage from when MMC is being
3612 used in raw mode (for Falcon mode)
3614 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3615 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3616 Sector and number of sectors to load kernel argument
3617 parameters from when MMC is being used in raw mode
3620 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3621 Partition on the MMC to load U-Boot from when the MMC is being
3624 CONFIG_SPL_FAT_SUPPORT
3625 Support for fs/fat/libfat.o in SPL binary
3627 CONFIG_SPL_EXT_SUPPORT
3628 Support for EXT filesystem in SPL binary
3630 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3631 Filename to read to load U-Boot when reading from filesystem
3633 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3634 Filename to read to load kernel uImage when reading
3635 from filesystem (for Falcon mode)
3637 CONFIG_SPL_FS_LOAD_ARGS_NAME
3638 Filename to read to load kernel argument parameters
3639 when reading from filesystem (for Falcon mode)
3641 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3642 Set this for NAND SPL on PPC mpc83xx targets, so that
3643 start.S waits for the rest of the SPL to load before
3644 continuing (the hardware starts execution after just
3645 loading the first page rather than the full 4K).
3647 CONFIG_SPL_SKIP_RELOCATE
3648 Avoid SPL relocation
3650 CONFIG_SPL_NAND_BASE
3651 Include nand_base.c in the SPL. Requires
3652 CONFIG_SPL_NAND_DRIVERS.
3654 CONFIG_SPL_NAND_DRIVERS
3655 SPL uses normal NAND drivers, not minimal drivers.
3658 Include standard software ECC in the SPL
3660 CONFIG_SPL_NAND_SIMPLE
3661 Support for NAND boot using simple NAND drivers that
3662 expose the cmd_ctrl() interface.
3664 CONFIG_SPL_MTD_SUPPORT
3665 Support for the MTD subsystem within SPL. Useful for
3666 environment on NAND support within SPL.
3668 CONFIG_SPL_NAND_RAW_ONLY
3669 Support to boot only raw u-boot.bin images. Use this only
3670 if you need to save space.
3672 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3673 Set for the SPL on PPC mpc8xxx targets, support for
3674 drivers/ddr/fsl/libddr.o in SPL binary.
3676 CONFIG_SPL_COMMON_INIT_DDR
3677 Set for common ddr init with serial presence detect in
3680 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3681 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3682 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3683 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3684 CONFIG_SYS_NAND_ECCBYTES
3685 Defines the size and behavior of the NAND that SPL uses
3688 CONFIG_SPL_NAND_BOOT
3689 Add support NAND boot
3691 CONFIG_SYS_NAND_U_BOOT_OFFS
3692 Location in NAND to read U-Boot from
3694 CONFIG_SYS_NAND_U_BOOT_DST
3695 Location in memory to load U-Boot to
3697 CONFIG_SYS_NAND_U_BOOT_SIZE
3698 Size of image to load
3700 CONFIG_SYS_NAND_U_BOOT_START
3701 Entry point in loaded image to jump to
3703 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3704 Define this if you need to first read the OOB and then the
3705 data. This is used, for example, on davinci platforms.
3707 CONFIG_SPL_OMAP3_ID_NAND
3708 Support for an OMAP3-specific set of functions to return the
3709 ID and MFR of the first attached NAND chip, if present.
3711 CONFIG_SPL_SERIAL_SUPPORT
3712 Support for drivers/serial/libserial.o in SPL binary
3714 CONFIG_SPL_SPI_FLASH_SUPPORT
3715 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3717 CONFIG_SPL_SPI_SUPPORT
3718 Support for drivers/spi/libspi.o in SPL binary
3720 CONFIG_SPL_RAM_DEVICE
3721 Support for running image already present in ram, in SPL binary
3723 CONFIG_SPL_LIBGENERIC_SUPPORT
3724 Support for lib/libgeneric.o in SPL binary
3726 CONFIG_SPL_ENV_SUPPORT
3727 Support for the environment operating in SPL binary
3729 CONFIG_SPL_NET_SUPPORT
3730 Support for the net/libnet.o in SPL binary.
3731 It conflicts with SPL env from storage medium specified by
3732 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3735 Image offset to which the SPL should be padded before appending
3736 the SPL payload. By default, this is defined as
3737 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3738 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3739 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3742 Final target image containing SPL and payload. Some SPLs
3743 use an arch-specific makefile fragment instead, for
3744 example if more than one image needs to be produced.
3746 CONFIG_FIT_SPL_PRINT
3747 Printing information about a FIT image adds quite a bit of
3748 code to SPL. So this is normally disabled in SPL. Use this
3749 option to re-enable it. This will affect the output of the
3750 bootm command when booting a FIT image.
3754 Enable building of TPL globally.
3757 Image offset to which the TPL should be padded before appending
3758 the TPL payload. By default, this is defined as
3759 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3760 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3761 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3766 [so far only for SMDK2400 boards]
3768 - Modem support enable:
3769 CONFIG_MODEM_SUPPORT
3771 - RTS/CTS Flow control enable:
3774 - Modem debug support:
3775 CONFIG_MODEM_SUPPORT_DEBUG
3777 Enables debugging stuff (char screen[1024], dbg())
3778 for modem support. Useful only with BDI2000.
3780 - Interrupt support (PPC):
3782 There are common interrupt_init() and timer_interrupt()
3783 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3784 for CPU specific initialization. interrupt_init_cpu()
3785 should set decrementer_count to appropriate value. If
3786 CPU resets decrementer automatically after interrupt
3787 (ppc4xx) it should set decrementer_count to zero.
3788 timer_interrupt() calls timer_interrupt_cpu() for CPU
3789 specific handling. If board has watchdog / status_led
3790 / other_activity_monitor it works automatically from
3791 general timer_interrupt().
3795 In the target system modem support is enabled when a
3796 specific key (key combination) is pressed during
3797 power-on. Otherwise U-Boot will boot normally
3798 (autoboot). The key_pressed() function is called from
3799 board_init(). Currently key_pressed() is a dummy
3800 function, returning 1 and thus enabling modem
3803 If there are no modem init strings in the
3804 environment, U-Boot proceed to autoboot; the
3805 previous output (banner, info printfs) will be
3808 See also: doc/README.Modem
3810 Board initialization settings:
3811 ------------------------------
3813 During Initialization u-boot calls a number of board specific functions
3814 to allow the preparation of board specific prerequisites, e.g. pin setup
3815 before drivers are initialized. To enable these callbacks the
3816 following configuration macros have to be defined. Currently this is
3817 architecture specific, so please check arch/your_architecture/lib/board.c
3818 typically in board_init_f() and board_init_r().
3820 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3821 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3822 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3823 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3825 Configuration Settings:
3826 -----------------------
3828 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3829 Optionally it can be defined to support 64-bit memory commands.
3831 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3832 undefine this when you're short of memory.
3834 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3835 width of the commands listed in the 'help' command output.
3837 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3838 prompt for user input.
3840 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3842 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3844 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3846 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3847 the application (usually a Linux kernel) when it is
3850 - CONFIG_SYS_BAUDRATE_TABLE:
3851 List of legal baudrate settings for this board.
3853 - CONFIG_SYS_CONSOLE_INFO_QUIET
3854 Suppress display of console information at boot.
3856 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3857 If the board specific function
3858 extern int overwrite_console (void);
3859 returns 1, the stdin, stderr and stdout are switched to the
3860 serial port, else the settings in the environment are used.
3862 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3863 Enable the call to overwrite_console().
3865 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3866 Enable overwrite of previous console environment settings.
3868 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3869 Begin and End addresses of the area used by the
3872 - CONFIG_SYS_ALT_MEMTEST:
3873 Enable an alternate, more extensive memory test.
3875 - CONFIG_SYS_MEMTEST_SCRATCH:
3876 Scratch address used by the alternate memory test
3877 You only need to set this if address zero isn't writeable
3879 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3880 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3881 this specified memory area will get subtracted from the top
3882 (end) of RAM and won't get "touched" at all by U-Boot. By
3883 fixing up gd->ram_size the Linux kernel should gets passed
3884 the now "corrected" memory size and won't touch it either.
3885 This should work for arch/ppc and arch/powerpc. Only Linux
3886 board ports in arch/powerpc with bootwrapper support that
3887 recalculate the memory size from the SDRAM controller setup
3888 will have to get fixed in Linux additionally.
3890 This option can be used as a workaround for the 440EPx/GRx
3891 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3894 WARNING: Please make sure that this value is a multiple of
3895 the Linux page size (normally 4k). If this is not the case,
3896 then the end address of the Linux memory will be located at a
3897 non page size aligned address and this could cause major
3900 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3901 Enable temporary baudrate change while serial download
3903 - CONFIG_SYS_SDRAM_BASE:
3904 Physical start address of SDRAM. _Must_ be 0 here.
3906 - CONFIG_SYS_MBIO_BASE:
3907 Physical start address of Motherboard I/O (if using a
3910 - CONFIG_SYS_FLASH_BASE:
3911 Physical start address of Flash memory.
3913 - CONFIG_SYS_MONITOR_BASE:
3914 Physical start address of boot monitor code (set by
3915 make config files to be same as the text base address
3916 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3917 CONFIG_SYS_FLASH_BASE when booting from flash.
3919 - CONFIG_SYS_MONITOR_LEN:
3920 Size of memory reserved for monitor code, used to
3921 determine _at_compile_time_ (!) if the environment is
3922 embedded within the U-Boot image, or in a separate
3925 - CONFIG_SYS_MALLOC_LEN:
3926 Size of DRAM reserved for malloc() use.
3928 - CONFIG_SYS_MALLOC_F_LEN
3929 Size of the malloc() pool for use before relocation. If
3930 this is defined, then a very simple malloc() implementation
3931 will become available before relocation. The address is just
3932 below the global data, and the stack is moved down to make
3935 This feature allocates regions with increasing addresses
3936 within the region. calloc() is supported, but realloc()
3937 is not available. free() is supported but does nothing.
3938 The memory will be freed (or in fact just forgotten) when
3939 U-Boot relocates itself.
3941 Pre-relocation malloc() is only supported on ARM and sandbox
3942 at present but is fairly easy to enable for other archs.
3944 - CONFIG_SYS_MALLOC_SIMPLE
3945 Provides a simple and small malloc() and calloc() for those
3946 boards which do not use the full malloc in SPL (which is
3947 enabled with CONFIG_SYS_SPL_MALLOC_START).
3949 - CONFIG_SYS_NONCACHED_MEMORY:
3950 Size of non-cached memory area. This area of memory will be
3951 typically located right below the malloc() area and mapped
3952 uncached in the MMU. This is useful for drivers that would
3953 otherwise require a lot of explicit cache maintenance. For
3954 some drivers it's also impossible to properly maintain the
3955 cache. For example if the regions that need to be flushed
3956 are not a multiple of the cache-line size, *and* padding
3957 cannot be allocated between the regions to align them (i.e.
3958 if the HW requires a contiguous array of regions, and the
3959 size of each region is not cache-aligned), then a flush of
3960 one region may result in overwriting data that hardware has
3961 written to another region in the same cache-line. This can
3962 happen for example in network drivers where descriptors for
3963 buffers are typically smaller than the CPU cache-line (e.g.
3964 16 bytes vs. 32 or 64 bytes).
3966 Non-cached memory is only supported on 32-bit ARM at present.
3968 - CONFIG_SYS_BOOTM_LEN:
3969 Normally compressed uImages are limited to an
3970 uncompressed size of 8 MBytes. If this is not enough,
3971 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3972 to adjust this setting to your needs.
3974 - CONFIG_SYS_BOOTMAPSZ:
3975 Maximum size of memory mapped by the startup code of
3976 the Linux kernel; all data that must be processed by
3977 the Linux kernel (bd_info, boot arguments, FDT blob if
3978 used) must be put below this limit, unless "bootm_low"
3979 environment variable is defined and non-zero. In such case
3980 all data for the Linux kernel must be between "bootm_low"
3981 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3982 variable "bootm_mapsize" will override the value of
3983 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3984 then the value in "bootm_size" will be used instead.
3986 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3987 Enable initrd_high functionality. If defined then the
3988 initrd_high feature is enabled and the bootm ramdisk subcommand
3991 - CONFIG_SYS_BOOT_GET_CMDLINE:
3992 Enables allocating and saving kernel cmdline in space between
3993 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3995 - CONFIG_SYS_BOOT_GET_KBD:
3996 Enables allocating and saving a kernel copy of the bd_info in
3997 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3999 - CONFIG_SYS_MAX_FLASH_BANKS:
4000 Max number of Flash memory banks
4002 - CONFIG_SYS_MAX_FLASH_SECT:
4003 Max number of sectors on a Flash chip
4005 - CONFIG_SYS_FLASH_ERASE_TOUT:
4006 Timeout for Flash erase operations (in ms)
4008 - CONFIG_SYS_FLASH_WRITE_TOUT:
4009 Timeout for Flash write operations (in ms)
4011 - CONFIG_SYS_FLASH_LOCK_TOUT
4012 Timeout for Flash set sector lock bit operation (in ms)
4014 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4015 Timeout for Flash clear lock bits operation (in ms)
4017 - CONFIG_SYS_FLASH_PROTECTION
4018 If defined, hardware flash sectors protection is used
4019 instead of U-Boot software protection.
4021 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4023 Enable TFTP transfers directly to flash memory;
4024 without this option such a download has to be
4025 performed in two steps: (1) download to RAM, and (2)
4026 copy from RAM to flash.
4028 The two-step approach is usually more reliable, since
4029 you can check if the download worked before you erase
4030 the flash, but in some situations (when system RAM is
4031 too limited to allow for a temporary copy of the
4032 downloaded image) this option may be very useful.
4034 - CONFIG_SYS_FLASH_CFI:
4035 Define if the flash driver uses extra elements in the
4036 common flash structure for storing flash geometry.
4038 - CONFIG_FLASH_CFI_DRIVER
4039 This option also enables the building of the cfi_flash driver
4040 in the drivers directory
4042 - CONFIG_FLASH_CFI_MTD
4043 This option enables the building of the cfi_mtd driver
4044 in the drivers directory. The driver exports CFI flash
4047 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4048 Use buffered writes to flash.
4050 - CONFIG_FLASH_SPANSION_S29WS_N
4051 s29ws-n MirrorBit flash has non-standard addresses for buffered
4054 - CONFIG_SYS_FLASH_QUIET_TEST
4055 If this option is defined, the common CFI flash doesn't
4056 print it's warning upon not recognized FLASH banks. This
4057 is useful, if some of the configured banks are only
4058 optionally available.
4060 - CONFIG_FLASH_SHOW_PROGRESS
4061 If defined (must be an integer), print out countdown
4062 digits and dots. Recommended value: 45 (9..1) for 80
4063 column displays, 15 (3..1) for 40 column displays.
4065 - CONFIG_FLASH_VERIFY
4066 If defined, the content of the flash (destination) is compared
4067 against the source after the write operation. An error message
4068 will be printed when the contents are not identical.
4069 Please note that this option is useless in nearly all cases,
4070 since such flash programming errors usually are detected earlier
4071 while unprotecting/erasing/programming. Please only enable
4072 this option if you really know what you are doing.
4074 - CONFIG_SYS_RX_ETH_BUFFER:
4075 Defines the number of Ethernet receive buffers. On some
4076 Ethernet controllers it is recommended to set this value
4077 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4078 buffers can be full shortly after enabling the interface
4079 on high Ethernet traffic.
4080 Defaults to 4 if not defined.
4082 - CONFIG_ENV_MAX_ENTRIES
4084 Maximum number of entries in the hash table that is used
4085 internally to store the environment settings. The default
4086 setting is supposed to be generous and should work in most
4087 cases. This setting can be used to tune behaviour; see
4088 lib/hashtable.c for details.
4090 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4091 - CONFIG_ENV_FLAGS_LIST_STATIC
4092 Enable validation of the values given to environment variables when
4093 calling env set. Variables can be restricted to only decimal,
4094 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4095 the variables can also be restricted to IP address or MAC address.
4097 The format of the list is:
4098 type_attribute = [s|d|x|b|i|m]
4099 access_attribute = [a|r|o|c]
4100 attributes = type_attribute[access_attribute]
4101 entry = variable_name[:attributes]
4104 The type attributes are:
4105 s - String (default)
4108 b - Boolean ([1yYtT|0nNfF])
4112 The access attributes are:
4118 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4119 Define this to a list (string) to define the ".flags"
4120 environment variable in the default or embedded environment.
4122 - CONFIG_ENV_FLAGS_LIST_STATIC
4123 Define this to a list (string) to define validation that
4124 should be done if an entry is not found in the ".flags"
4125 environment variable. To override a setting in the static
4126 list, simply add an entry for the same variable name to the
4129 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4130 regular expression. This allows multiple variables to define the same
4131 flags without explicitly listing them for each variable.
4133 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4134 If defined, don't allow the -f switch to env set override variable
4137 - CONFIG_SYS_GENERIC_BOARD
4138 This selects the architecture-generic board system instead of the
4139 architecture-specific board files. It is intended to move boards
4140 to this new framework over time. Defining this will disable the
4141 arch/foo/lib/board.c file and use common/board_f.c and
4142 common/board_r.c instead. To use this option your architecture
4143 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4144 If you find problems enabling this option on your board please report
4145 the problem and send patches!
4147 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4148 This is set by OMAP boards for the max time that reset should
4149 be asserted. See doc/README.omap-reset-time for details on how
4150 the value can be calculated on a given board.
4153 If stdint.h is available with your toolchain you can define this
4154 option to enable it. You can provide option 'USE_STDINT=1' when
4155 building U-Boot to enable this.
4157 The following definitions that deal with the placement and management
4158 of environment data (variable area); in general, we support the
4159 following configurations:
4161 - CONFIG_BUILD_ENVCRC:
4163 Builds up envcrc with the target environment so that external utils
4164 may easily extract it and embed it in final U-Boot images.
4166 - CONFIG_ENV_IS_IN_FLASH:
4168 Define this if the environment is in flash memory.
4170 a) The environment occupies one whole flash sector, which is
4171 "embedded" in the text segment with the U-Boot code. This
4172 happens usually with "bottom boot sector" or "top boot
4173 sector" type flash chips, which have several smaller
4174 sectors at the start or the end. For instance, such a
4175 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4176 such a case you would place the environment in one of the
4177 4 kB sectors - with U-Boot code before and after it. With
4178 "top boot sector" type flash chips, you would put the
4179 environment in one of the last sectors, leaving a gap
4180 between U-Boot and the environment.
4182 - CONFIG_ENV_OFFSET:
4184 Offset of environment data (variable area) to the
4185 beginning of flash memory; for instance, with bottom boot
4186 type flash chips the second sector can be used: the offset
4187 for this sector is given here.
4189 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4193 This is just another way to specify the start address of
4194 the flash sector containing the environment (instead of
4197 - CONFIG_ENV_SECT_SIZE:
4199 Size of the sector containing the environment.
4202 b) Sometimes flash chips have few, equal sized, BIG sectors.
4203 In such a case you don't want to spend a whole sector for
4208 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4209 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4210 of this flash sector for the environment. This saves
4211 memory for the RAM copy of the environment.
4213 It may also save flash memory if you decide to use this
4214 when your environment is "embedded" within U-Boot code,
4215 since then the remainder of the flash sector could be used
4216 for U-Boot code. It should be pointed out that this is
4217 STRONGLY DISCOURAGED from a robustness point of view:
4218 updating the environment in flash makes it always
4219 necessary to erase the WHOLE sector. If something goes
4220 wrong before the contents has been restored from a copy in
4221 RAM, your target system will be dead.
4223 - CONFIG_ENV_ADDR_REDUND
4224 CONFIG_ENV_SIZE_REDUND
4226 These settings describe a second storage area used to hold
4227 a redundant copy of the environment data, so that there is
4228 a valid backup copy in case there is a power failure during
4229 a "saveenv" operation.
4231 BE CAREFUL! Any changes to the flash layout, and some changes to the
4232 source code will make it necessary to adapt <board>/u-boot.lds*
4236 - CONFIG_ENV_IS_IN_NVRAM:
4238 Define this if you have some non-volatile memory device
4239 (NVRAM, battery buffered SRAM) which you want to use for the
4245 These two #defines are used to determine the memory area you
4246 want to use for environment. It is assumed that this memory
4247 can just be read and written to, without any special
4250 BE CAREFUL! The first access to the environment happens quite early
4251 in U-Boot initialization (when we try to get the setting of for the
4252 console baudrate). You *MUST* have mapped your NVRAM area then, or
4255 Please note that even with NVRAM we still use a copy of the
4256 environment in RAM: we could work on NVRAM directly, but we want to
4257 keep settings there always unmodified except somebody uses "saveenv"
4258 to save the current settings.
4261 - CONFIG_ENV_IS_IN_EEPROM:
4263 Use this if you have an EEPROM or similar serial access
4264 device and a driver for it.
4266 - CONFIG_ENV_OFFSET:
4269 These two #defines specify the offset and size of the
4270 environment area within the total memory of your EEPROM.
4272 - CONFIG_SYS_I2C_EEPROM_ADDR:
4273 If defined, specified the chip address of the EEPROM device.
4274 The default address is zero.
4276 - CONFIG_SYS_I2C_EEPROM_BUS:
4277 If defined, specified the i2c bus of the EEPROM device.
4279 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4280 If defined, the number of bits used to address bytes in a
4281 single page in the EEPROM device. A 64 byte page, for example
4282 would require six bits.
4284 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4285 If defined, the number of milliseconds to delay between
4286 page writes. The default is zero milliseconds.
4288 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4289 The length in bytes of the EEPROM memory array address. Note
4290 that this is NOT the chip address length!
4292 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4293 EEPROM chips that implement "address overflow" are ones
4294 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4295 address and the extra bits end up in the "chip address" bit
4296 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4299 Note that we consider the length of the address field to
4300 still be one byte because the extra address bits are hidden
4301 in the chip address.
4303 - CONFIG_SYS_EEPROM_SIZE:
4304 The size in bytes of the EEPROM device.
4306 - CONFIG_ENV_EEPROM_IS_ON_I2C
4307 define this, if you have I2C and SPI activated, and your
4308 EEPROM, which holds the environment, is on the I2C bus.
4310 - CONFIG_I2C_ENV_EEPROM_BUS
4311 if you have an Environment on an EEPROM reached over
4312 I2C muxes, you can define here, how to reach this
4313 EEPROM. For example:
4315 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4317 EEPROM which holds the environment, is reached over
4318 a pca9547 i2c mux with address 0x70, channel 3.
4320 - CONFIG_ENV_IS_IN_DATAFLASH:
4322 Define this if you have a DataFlash memory device which you
4323 want to use for the environment.
4325 - CONFIG_ENV_OFFSET:
4329 These three #defines specify the offset and size of the
4330 environment area within the total memory of your DataFlash placed
4331 at the specified address.
4333 - CONFIG_ENV_IS_IN_SPI_FLASH:
4335 Define this if you have a SPI Flash memory device which you
4336 want to use for the environment.
4338 - CONFIG_ENV_OFFSET:
4341 These two #defines specify the offset and size of the
4342 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4343 aligned to an erase sector boundary.
4345 - CONFIG_ENV_SECT_SIZE:
4347 Define the SPI flash's sector size.
4349 - CONFIG_ENV_OFFSET_REDUND (optional):
4351 This setting describes a second storage area of CONFIG_ENV_SIZE
4352 size used to hold a redundant copy of the environment data, so
4353 that there is a valid backup copy in case there is a power failure
4354 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4355 aligned to an erase sector boundary.
4357 - CONFIG_ENV_SPI_BUS (optional):
4358 - CONFIG_ENV_SPI_CS (optional):
4360 Define the SPI bus and chip select. If not defined they will be 0.
4362 - CONFIG_ENV_SPI_MAX_HZ (optional):
4364 Define the SPI max work clock. If not defined then use 1MHz.
4366 - CONFIG_ENV_SPI_MODE (optional):
4368 Define the SPI work mode. If not defined then use SPI_MODE_3.
4370 - CONFIG_ENV_IS_IN_REMOTE:
4372 Define this if you have a remote memory space which you
4373 want to use for the local device's environment.
4378 These two #defines specify the address and size of the
4379 environment area within the remote memory space. The
4380 local device can get the environment from remote memory
4381 space by SRIO or PCIE links.
4383 BE CAREFUL! For some special cases, the local device can not use
4384 "saveenv" command. For example, the local device will get the
4385 environment stored in a remote NOR flash by SRIO or PCIE link,
4386 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4388 - CONFIG_ENV_IS_IN_NAND:
4390 Define this if you have a NAND device which you want to use
4391 for the environment.
4393 - CONFIG_ENV_OFFSET:
4396 These two #defines specify the offset and size of the environment
4397 area within the first NAND device. CONFIG_ENV_OFFSET must be
4398 aligned to an erase block boundary.
4400 - CONFIG_ENV_OFFSET_REDUND (optional):
4402 This setting describes a second storage area of CONFIG_ENV_SIZE
4403 size used to hold a redundant copy of the environment data, so
4404 that there is a valid backup copy in case there is a power failure
4405 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4406 aligned to an erase block boundary.
4408 - CONFIG_ENV_RANGE (optional):
4410 Specifies the length of the region in which the environment
4411 can be written. This should be a multiple of the NAND device's
4412 block size. Specifying a range with more erase blocks than
4413 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4414 the range to be avoided.
4416 - CONFIG_ENV_OFFSET_OOB (optional):
4418 Enables support for dynamically retrieving the offset of the
4419 environment from block zero's out-of-band data. The
4420 "nand env.oob" command can be used to record this offset.
4421 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4422 using CONFIG_ENV_OFFSET_OOB.
4424 - CONFIG_NAND_ENV_DST
4426 Defines address in RAM to which the nand_spl code should copy the
4427 environment. If redundant environment is used, it will be copied to
4428 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4430 - CONFIG_ENV_IS_IN_UBI:
4432 Define this if you have an UBI volume that you want to use for the
4433 environment. This has the benefit of wear-leveling the environment
4434 accesses, which is important on NAND.
4436 - CONFIG_ENV_UBI_PART:
4438 Define this to a string that is the mtd partition containing the UBI.
4440 - CONFIG_ENV_UBI_VOLUME:
4442 Define this to the name of the volume that you want to store the
4445 - CONFIG_ENV_UBI_VOLUME_REDUND:
4447 Define this to the name of another volume to store a second copy of
4448 the environment in. This will enable redundant environments in UBI.
4449 It is assumed that both volumes are in the same MTD partition.
4451 - CONFIG_UBI_SILENCE_MSG
4452 - CONFIG_UBIFS_SILENCE_MSG
4454 You will probably want to define these to avoid a really noisy system
4455 when storing the env in UBI.
4457 - CONFIG_ENV_IS_IN_FAT:
4458 Define this if you want to use the FAT file system for the environment.
4460 - FAT_ENV_INTERFACE:
4462 Define this to a string that is the name of the block device.
4464 - FAT_ENV_DEV_AND_PART:
4466 Define this to a string to specify the partition of the device. It can
4469 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4470 - "D:P": device D partition P. Error occurs if device D has no
4473 - "D" or "D:": device D partition 1 if device D has partition
4474 table, or the whole device D if has no partition
4476 - "D:auto": first partition in device D with bootable flag set.
4477 If none, first valid partition in device D. If no
4478 partition table then means device D.
4482 It's a string of the FAT file name. This file use to store the
4486 This should be defined. Otherwise it cannot save the environment file.
4488 - CONFIG_ENV_IS_IN_MMC:
4490 Define this if you have an MMC device which you want to use for the
4493 - CONFIG_SYS_MMC_ENV_DEV:
4495 Specifies which MMC device the environment is stored in.
4497 - CONFIG_SYS_MMC_ENV_PART (optional):
4499 Specifies which MMC partition the environment is stored in. If not
4500 set, defaults to partition 0, the user area. Common values might be
4501 1 (first MMC boot partition), 2 (second MMC boot partition).
4503 - CONFIG_ENV_OFFSET:
4506 These two #defines specify the offset and size of the environment
4507 area within the specified MMC device.
4509 If offset is positive (the usual case), it is treated as relative to
4510 the start of the MMC partition. If offset is negative, it is treated
4511 as relative to the end of the MMC partition. This can be useful if
4512 your board may be fitted with different MMC devices, which have
4513 different sizes for the MMC partitions, and you always want the
4514 environment placed at the very end of the partition, to leave the
4515 maximum possible space before it, to store other data.
4517 These two values are in units of bytes, but must be aligned to an
4518 MMC sector boundary.
4520 - CONFIG_ENV_OFFSET_REDUND (optional):
4522 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4523 hold a redundant copy of the environment data. This provides a
4524 valid backup copy in case the other copy is corrupted, e.g. due
4525 to a power failure during a "saveenv" operation.
4527 This value may also be positive or negative; this is handled in the
4528 same way as CONFIG_ENV_OFFSET.
4530 This value is also in units of bytes, but must also be aligned to
4531 an MMC sector boundary.
4533 - CONFIG_ENV_SIZE_REDUND (optional):
4535 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4536 set. If this value is set, it must be set to the same value as
4539 - CONFIG_SYS_SPI_INIT_OFFSET
4541 Defines offset to the initial SPI buffer area in DPRAM. The
4542 area is used at an early stage (ROM part) if the environment
4543 is configured to reside in the SPI EEPROM: We need a 520 byte
4544 scratch DPRAM area. It is used between the two initialization
4545 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4546 to be a good choice since it makes it far enough from the
4547 start of the data area as well as from the stack pointer.
4549 Please note that the environment is read-only until the monitor
4550 has been relocated to RAM and a RAM copy of the environment has been
4551 created; also, when using EEPROM you will have to use getenv_f()
4552 until then to read environment variables.
4554 The environment is protected by a CRC32 checksum. Before the monitor
4555 is relocated into RAM, as a result of a bad CRC you will be working
4556 with the compiled-in default environment - *silently*!!! [This is
4557 necessary, because the first environment variable we need is the
4558 "baudrate" setting for the console - if we have a bad CRC, we don't
4559 have any device yet where we could complain.]
4561 Note: once the monitor has been relocated, then it will complain if
4562 the default environment is used; a new CRC is computed as soon as you
4563 use the "saveenv" command to store a valid environment.
4565 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4566 Echo the inverted Ethernet link state to the fault LED.
4568 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4569 also needs to be defined.
4571 - CONFIG_SYS_FAULT_MII_ADDR:
4572 MII address of the PHY to check for the Ethernet link state.
4574 - CONFIG_NS16550_MIN_FUNCTIONS:
4575 Define this if you desire to only have use of the NS16550_init
4576 and NS16550_putc functions for the serial driver located at
4577 drivers/serial/ns16550.c. This option is useful for saving
4578 space for already greatly restricted images, including but not
4579 limited to NAND_SPL configurations.
4581 - CONFIG_DISPLAY_BOARDINFO
4582 Display information about the board that U-Boot is running on
4583 when U-Boot starts up. The board function checkboard() is called
4586 - CONFIG_DISPLAY_BOARDINFO_LATE
4587 Similar to the previous option, but display this information
4588 later, once stdio is running and output goes to the LCD, if
4591 - CONFIG_BOARD_SIZE_LIMIT:
4592 Maximum size of the U-Boot image. When defined, the
4593 build system checks that the actual size does not
4596 Low Level (hardware related) configuration options:
4597 ---------------------------------------------------
4599 - CONFIG_SYS_CACHELINE_SIZE:
4600 Cache Line Size of the CPU.
4602 - CONFIG_SYS_DEFAULT_IMMR:
4603 Default address of the IMMR after system reset.
4605 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4606 and RPXsuper) to be able to adjust the position of
4607 the IMMR register after a reset.
4609 - CONFIG_SYS_CCSRBAR_DEFAULT:
4610 Default (power-on reset) physical address of CCSR on Freescale
4613 - CONFIG_SYS_CCSRBAR:
4614 Virtual address of CCSR. On a 32-bit build, this is typically
4615 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4617 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4618 for cross-platform code that uses that macro instead.
4620 - CONFIG_SYS_CCSRBAR_PHYS:
4621 Physical address of CCSR. CCSR can be relocated to a new
4622 physical address, if desired. In this case, this macro should
4623 be set to that address. Otherwise, it should be set to the
4624 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4625 is typically relocated on 36-bit builds. It is recommended
4626 that this macro be defined via the _HIGH and _LOW macros:
4628 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4629 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4631 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4632 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4633 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4634 used in assembly code, so it must not contain typecasts or
4635 integer size suffixes (e.g. "ULL").
4637 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4638 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4639 used in assembly code, so it must not contain typecasts or
4640 integer size suffixes (e.g. "ULL").
4642 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4643 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4644 forced to a value that ensures that CCSR is not relocated.
4646 - Floppy Disk Support:
4647 CONFIG_SYS_FDC_DRIVE_NUMBER
4649 the default drive number (default value 0)
4651 CONFIG_SYS_ISA_IO_STRIDE
4653 defines the spacing between FDC chipset registers
4656 CONFIG_SYS_ISA_IO_OFFSET
4658 defines the offset of register from address. It
4659 depends on which part of the data bus is connected to
4660 the FDC chipset. (default value 0)
4662 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4663 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4666 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4667 fdc_hw_init() is called at the beginning of the FDC
4668 setup. fdc_hw_init() must be provided by the board
4669 source code. It is used to make hardware-dependent
4673 Most IDE controllers were designed to be connected with PCI
4674 interface. Only few of them were designed for AHB interface.
4675 When software is doing ATA command and data transfer to
4676 IDE devices through IDE-AHB controller, some additional
4677 registers accessing to these kind of IDE-AHB controller
4680 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4681 DO NOT CHANGE unless you know exactly what you're
4682 doing! (11-4) [MPC8xx/82xx systems only]
4684 - CONFIG_SYS_INIT_RAM_ADDR:
4686 Start address of memory area that can be used for
4687 initial data and stack; please note that this must be
4688 writable memory that is working WITHOUT special
4689 initialization, i. e. you CANNOT use normal RAM which
4690 will become available only after programming the
4691 memory controller and running certain initialization
4694 U-Boot uses the following memory types:
4695 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4696 - MPC824X: data cache
4697 - PPC4xx: data cache
4699 - CONFIG_SYS_GBL_DATA_OFFSET:
4701 Offset of the initial data structure in the memory
4702 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4703 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4704 data is located at the end of the available space
4705 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4706 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4707 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4708 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4711 On the MPC824X (or other systems that use the data
4712 cache for initial memory) the address chosen for
4713 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4714 point to an otherwise UNUSED address space between
4715 the top of RAM and the start of the PCI space.
4717 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4719 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4721 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4723 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4725 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4727 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4729 - CONFIG_SYS_OR_TIMING_SDRAM:
4732 - CONFIG_SYS_MAMR_PTA:
4733 periodic timer for refresh
4735 - CONFIG_SYS_DER: Debug Event Register (37-47)
4737 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4738 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4739 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4740 CONFIG_SYS_BR1_PRELIM:
4741 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4743 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4744 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4745 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4746 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4748 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4749 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4750 Machine Mode Register and Memory Periodic Timer
4751 Prescaler definitions (SDRAM timing)
4753 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4754 enable I2C microcode relocation patch (MPC8xx);
4755 define relocation offset in DPRAM [DSP2]
4757 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4758 enable SMC microcode relocation patch (MPC8xx);
4759 define relocation offset in DPRAM [SMC1]
4761 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4762 enable SPI microcode relocation patch (MPC8xx);
4763 define relocation offset in DPRAM [SCC4]
4765 - CONFIG_SYS_USE_OSCCLK:
4766 Use OSCM clock mode on MBX8xx board. Be careful,
4767 wrong setting might damage your board. Read
4768 doc/README.MBX before setting this variable!
4770 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4771 Offset of the bootmode word in DPRAM used by post
4772 (Power On Self Tests). This definition overrides
4773 #define'd default value in commproc.h resp.
4776 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4777 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4778 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4779 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4780 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4781 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4782 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4783 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4784 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4786 - CONFIG_PCI_DISABLE_PCIE:
4787 Disable PCI-Express on systems where it is supported but not
4790 - CONFIG_PCI_ENUM_ONLY
4791 Only scan through and get the devices on the buses.
4792 Don't do any setup work, presumably because someone or
4793 something has already done it, and we don't need to do it
4794 a second time. Useful for platforms that are pre-booted
4795 by coreboot or similar.
4797 - CONFIG_PCI_INDIRECT_BRIDGE:
4798 Enable support for indirect PCI bridges.
4801 Chip has SRIO or not
4804 Board has SRIO 1 port available
4807 Board has SRIO 2 port available
4809 - CONFIG_SRIO_PCIE_BOOT_MASTER
4810 Board can support master function for Boot from SRIO and PCIE
4812 - CONFIG_SYS_SRIOn_MEM_VIRT:
4813 Virtual Address of SRIO port 'n' memory region
4815 - CONFIG_SYS_SRIOn_MEM_PHYS:
4816 Physical Address of SRIO port 'n' memory region
4818 - CONFIG_SYS_SRIOn_MEM_SIZE:
4819 Size of SRIO port 'n' memory region
4821 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4822 Defined to tell the NAND controller that the NAND chip is using
4824 Not all NAND drivers use this symbol.
4825 Example of drivers that use it:
4826 - drivers/mtd/nand/ndfc.c
4827 - drivers/mtd/nand/mxc_nand.c
4829 - CONFIG_SYS_NDFC_EBC0_CFG
4830 Sets the EBC0_CFG register for the NDFC. If not defined
4831 a default value will be used.
4834 Get DDR timing information from an I2C EEPROM. Common
4835 with pluggable memory modules such as SODIMMs
4838 I2C address of the SPD EEPROM
4840 - CONFIG_SYS_SPD_BUS_NUM
4841 If SPD EEPROM is on an I2C bus other than the first
4842 one, specify here. Note that the value must resolve
4843 to something your driver can deal with.
4845 - CONFIG_SYS_DDR_RAW_TIMING
4846 Get DDR timing information from other than SPD. Common with
4847 soldered DDR chips onboard without SPD. DDR raw timing
4848 parameters are extracted from datasheet and hard-coded into
4849 header files or board specific files.
4851 - CONFIG_FSL_DDR_INTERACTIVE
4852 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4854 - CONFIG_FSL_DDR_SYNC_REFRESH
4855 Enable sync of refresh for multiple controllers.
4857 - CONFIG_FSL_DDR_BIST
4858 Enable built-in memory test for Freescale DDR controllers.
4860 - CONFIG_SYS_83XX_DDR_USES_CS0
4861 Only for 83xx systems. If specified, then DDR should
4862 be configured using CS0 and CS1 instead of CS2 and CS3.
4864 - CONFIG_ETHER_ON_FEC[12]
4865 Define to enable FEC[12] on a 8xx series processor.
4867 - CONFIG_FEC[12]_PHY
4868 Define to the hardcoded PHY address which corresponds
4869 to the given FEC; i. e.
4870 #define CONFIG_FEC1_PHY 4
4871 means that the PHY with address 4 is connected to FEC1
4873 When set to -1, means to probe for first available.
4875 - CONFIG_FEC[12]_PHY_NORXERR
4876 The PHY does not have a RXERR line (RMII only).
4877 (so program the FEC to ignore it).
4880 Enable RMII mode for all FECs.
4881 Note that this is a global option, we can't
4882 have one FEC in standard MII mode and another in RMII mode.
4884 - CONFIG_CRC32_VERIFY
4885 Add a verify option to the crc32 command.
4888 => crc32 -v <address> <count> <crc32>
4890 Where address/count indicate a memory area
4891 and crc32 is the correct crc32 which the
4895 Add the "loopw" memory command. This only takes effect if
4896 the memory commands are activated globally (CONFIG_CMD_MEM).
4899 Add the "mdc" and "mwc" memory commands. These are cyclic
4904 This command will print 4 bytes (10,11,12,13) each 500 ms.
4906 => mwc.l 100 12345678 10
4907 This command will write 12345678 to address 100 all 10 ms.
4909 This only takes effect if the memory commands are activated
4910 globally (CONFIG_CMD_MEM).
4912 - CONFIG_SKIP_LOWLEVEL_INIT
4913 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4914 low level initializations (like setting up the memory
4915 controller) are omitted and/or U-Boot does not
4916 relocate itself into RAM.
4918 Normally this variable MUST NOT be defined. The only
4919 exception is when U-Boot is loaded (to RAM) by some
4920 other boot loader or by a debugger which performs
4921 these initializations itself.
4924 Modifies the behaviour of start.S when compiling a loader
4925 that is executed before the actual U-Boot. E.g. when
4926 compiling a NAND SPL.
4929 Modifies the behaviour of start.S when compiling a loader
4930 that is executed after the SPL and before the actual U-Boot.
4931 It is loaded by the SPL.
4933 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4934 Only for 85xx systems. If this variable is specified, the section
4935 .resetvec is not kept and the section .bootpg is placed in the
4936 previous 4k of the .text section.
4938 - CONFIG_ARCH_MAP_SYSMEM
4939 Generally U-Boot (and in particular the md command) uses
4940 effective address. It is therefore not necessary to regard
4941 U-Boot address as virtual addresses that need to be translated
4942 to physical addresses. However, sandbox requires this, since
4943 it maintains its own little RAM buffer which contains all
4944 addressable memory. This option causes some memory accesses
4945 to be mapped through map_sysmem() / unmap_sysmem().
4947 - CONFIG_USE_ARCH_MEMCPY
4948 CONFIG_USE_ARCH_MEMSET
4949 If these options are used a optimized version of memcpy/memset will
4950 be used if available. These functions may be faster under some
4951 conditions but may increase the binary size.
4953 - CONFIG_X86_RESET_VECTOR
4954 If defined, the x86 reset vector code is included. This is not
4955 needed when U-Boot is running from Coreboot.
4958 Defines the MPU clock speed (in MHz).
4960 NOTE : currently only supported on AM335x platforms.
4962 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4963 Enables the RTC32K OSC on AM33xx based plattforms
4965 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4966 Option to disable subpage write in NAND driver
4967 driver that uses this:
4968 drivers/mtd/nand/davinci_nand.c
4970 Freescale QE/FMAN Firmware Support:
4971 -----------------------------------
4973 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4974 loading of "firmware", which is encoded in the QE firmware binary format.
4975 This firmware often needs to be loaded during U-Boot booting, so macros
4976 are used to identify the storage device (NOR flash, SPI, etc) and the address
4979 - CONFIG_SYS_FMAN_FW_ADDR
4980 The address in the storage device where the FMAN microcode is located. The
4981 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4984 - CONFIG_SYS_QE_FW_ADDR
4985 The address in the storage device where the QE microcode is located. The
4986 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4989 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4990 The maximum possible size of the firmware. The firmware binary format
4991 has a field that specifies the actual size of the firmware, but it
4992 might not be possible to read any part of the firmware unless some
4993 local storage is allocated to hold the entire firmware first.
4995 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4996 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4997 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4998 virtual address in NOR flash.
5000 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5001 Specifies that QE/FMAN firmware is located in NAND flash.
5002 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5004 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5005 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5006 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5008 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5009 Specifies that QE/FMAN firmware is located on the primary SPI
5010 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5012 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5013 Specifies that QE/FMAN firmware is located in the remote (master)
5014 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5015 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5016 window->master inbound window->master LAW->the ucode address in
5017 master's memory space.
5019 Freescale Layerscape Management Complex Firmware Support:
5020 ---------------------------------------------------------
5021 The Freescale Layerscape Management Complex (MC) supports the loading of
5023 This firmware often needs to be loaded during U-Boot booting, so macros
5024 are used to identify the storage device (NOR flash, SPI, etc) and the address
5027 - CONFIG_FSL_MC_ENET
5028 Enable the MC driver for Layerscape SoCs.
5030 - CONFIG_SYS_LS_MC_FW_ADDR
5031 The address in the storage device where the firmware is located. The
5032 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5035 - CONFIG_SYS_LS_MC_FW_LENGTH
5036 The maximum possible size of the firmware. The firmware binary format
5037 has a field that specifies the actual size of the firmware, but it
5038 might not be possible to read any part of the firmware unless some
5039 local storage is allocated to hold the entire firmware first.
5041 - CONFIG_SYS_LS_MC_FW_IN_NOR
5042 Specifies that MC firmware is located in NOR flash, mapped as
5043 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5044 virtual address in NOR flash.
5046 Freescale Layerscape Debug Server Support:
5047 -------------------------------------------
5048 The Freescale Layerscape Debug Server Support supports the loading of
5049 "Debug Server firmware" and triggering SP boot-rom.
5050 This firmware often needs to be loaded during U-Boot booting.
5052 - CONFIG_FSL_DEBUG_SERVER
5053 Enable the Debug Server for Layerscape SoCs.
5055 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5056 Define minimum DDR size required for debug server image
5058 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5059 Define minimum DDR size to be hided from top of the DDR memory
5064 In order to achieve reproducible builds, timestamps used in the U-Boot build
5065 process have to be set to a fixed value.
5067 This is done using the SOURCE_DATE_EPOCH environment variable.
5068 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5069 option for U-Boot or an environment variable in U-Boot.
5071 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5073 Building the Software:
5074 ======================
5076 Building U-Boot has been tested in several native build environments
5077 and in many different cross environments. Of course we cannot support
5078 all possibly existing versions of cross development tools in all
5079 (potentially obsolete) versions. In case of tool chain problems we
5080 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5081 which is extensively used to build and test U-Boot.
5083 If you are not using a native environment, it is assumed that you
5084 have GNU cross compiling tools available in your path. In this case,
5085 you must set the environment variable CROSS_COMPILE in your shell.
5086 Note that no changes to the Makefile or any other source files are
5087 necessary. For example using the ELDK on a 4xx CPU, please enter:
5089 $ CROSS_COMPILE=ppc_4xx-
5090 $ export CROSS_COMPILE
5092 Note: If you wish to generate Windows versions of the utilities in
5093 the tools directory you can use the MinGW toolchain
5094 (http://www.mingw.org). Set your HOST tools to the MinGW
5095 toolchain and execute 'make tools'. For example:
5097 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5099 Binaries such as tools/mkimage.exe will be created which can
5100 be executed on computers running Windows.
5102 U-Boot is intended to be simple to build. After installing the
5103 sources you must configure U-Boot for one specific board type. This
5108 where "NAME_defconfig" is the name of one of the existing configu-
5109 rations; see boards.cfg for supported names.
5111 Note: for some board special configuration names may exist; check if
5112 additional information is available from the board vendor; for
5113 instance, the TQM823L systems are available without (standard)
5114 or with LCD support. You can select such additional "features"
5115 when choosing the configuration, i. e.
5117 make TQM823L_defconfig
5118 - will configure for a plain TQM823L, i. e. no LCD support
5120 make TQM823L_LCD_defconfig
5121 - will configure for a TQM823L with U-Boot console on LCD
5126 Finally, type "make all", and you should get some working U-Boot
5127 images ready for download to / installation on your system:
5129 - "u-boot.bin" is a raw binary image
5130 - "u-boot" is an image in ELF binary format
5131 - "u-boot.srec" is in Motorola S-Record format
5133 By default the build is performed locally and the objects are saved
5134 in the source directory. One of the two methods can be used to change
5135 this behavior and build U-Boot to some external directory:
5137 1. Add O= to the make command line invocations:
5139 make O=/tmp/build distclean
5140 make O=/tmp/build NAME_defconfig
5141 make O=/tmp/build all
5143 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5145 export KBUILD_OUTPUT=/tmp/build
5150 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5154 Please be aware that the Makefiles assume you are using GNU make, so
5155 for instance on NetBSD you might need to use "gmake" instead of
5159 If the system board that you have is not listed, then you will need
5160 to port U-Boot to your hardware platform. To do this, follow these
5163 1. Add a new configuration option for your board to the toplevel
5164 "boards.cfg" file, using the existing entries as examples.
5165 Follow the instructions there to keep the boards in order.
5166 2. Create a new directory to hold your board specific code. Add any
5167 files you need. In your board directory, you will need at least
5168 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5169 3. Create a new configuration file "include/configs/<board>.h" for
5171 3. If you're porting U-Boot to a new CPU, then also create a new
5172 directory to hold your CPU specific code. Add any files you need.
5173 4. Run "make <board>_defconfig" with your new name.
5174 5. Type "make", and you should get a working "u-boot.srec" file
5175 to be installed on your target system.
5176 6. Debug and solve any problems that might arise.
5177 [Of course, this last step is much harder than it sounds.]
5180 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5181 ==============================================================
5183 If you have modified U-Boot sources (for instance added a new board
5184 or support for new devices, a new CPU, etc.) you are expected to
5185 provide feedback to the other developers. The feedback normally takes
5186 the form of a "patch", i. e. a context diff against a certain (latest
5187 official or latest in the git repository) version of U-Boot sources.
5189 But before you submit such a patch, please verify that your modifi-
5190 cation did not break existing code. At least make sure that *ALL* of
5191 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5192 just run the "MAKEALL" script, which will configure and build U-Boot
5193 for ALL supported system. Be warned, this will take a while. You can
5194 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5195 environment variable to the script, i. e. to use the ELDK cross tools
5198 CROSS_COMPILE=ppc_8xx- MAKEALL
5200 or to build on a native PowerPC system you can type
5202 CROSS_COMPILE=' ' MAKEALL
5204 When using the MAKEALL script, the default behaviour is to build
5205 U-Boot in the source directory. This location can be changed by
5206 setting the BUILD_DIR environment variable. Also, for each target
5207 built, the MAKEALL script saves two log files (<target>.ERR and
5208 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5209 location can be changed by setting the MAKEALL_LOGDIR environment
5210 variable. For example:
5212 export BUILD_DIR=/tmp/build
5213 export MAKEALL_LOGDIR=/tmp/log
5214 CROSS_COMPILE=ppc_8xx- MAKEALL
5216 With the above settings build objects are saved in the /tmp/build,
5217 log files are saved in the /tmp/log and the source tree remains clean
5218 during the whole build process.
5221 See also "U-Boot Porting Guide" below.
5224 Monitor Commands - Overview:
5225 ============================
5227 go - start application at address 'addr'
5228 run - run commands in an environment variable
5229 bootm - boot application image from memory
5230 bootp - boot image via network using BootP/TFTP protocol
5231 bootz - boot zImage from memory
5232 tftpboot- boot image via network using TFTP protocol
5233 and env variables "ipaddr" and "serverip"
5234 (and eventually "gatewayip")
5235 tftpput - upload a file via network using TFTP protocol
5236 rarpboot- boot image via network using RARP/TFTP protocol
5237 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5238 loads - load S-Record file over serial line
5239 loadb - load binary file over serial line (kermit mode)
5241 mm - memory modify (auto-incrementing)
5242 nm - memory modify (constant address)
5243 mw - memory write (fill)
5245 cmp - memory compare
5246 crc32 - checksum calculation
5247 i2c - I2C sub-system
5248 sspi - SPI utility commands
5249 base - print or set address offset
5250 printenv- print environment variables
5251 setenv - set environment variables
5252 saveenv - save environment variables to persistent storage
5253 protect - enable or disable FLASH write protection
5254 erase - erase FLASH memory
5255 flinfo - print FLASH memory information
5256 nand - NAND memory operations (see doc/README.nand)
5257 bdinfo - print Board Info structure
5258 iminfo - print header information for application image
5259 coninfo - print console devices and informations
5260 ide - IDE sub-system
5261 loop - infinite loop on address range
5262 loopw - infinite write loop on address range
5263 mtest - simple RAM test
5264 icache - enable or disable instruction cache
5265 dcache - enable or disable data cache
5266 reset - Perform RESET of the CPU
5267 echo - echo args to console
5268 version - print monitor version
5269 help - print online help
5270 ? - alias for 'help'
5273 Monitor Commands - Detailed Description:
5274 ========================================
5278 For now: just type "help <command>".
5281 Environment Variables:
5282 ======================
5284 U-Boot supports user configuration using Environment Variables which
5285 can be made persistent by saving to Flash memory.
5287 Environment Variables are set using "setenv", printed using
5288 "printenv", and saved to Flash using "saveenv". Using "setenv"
5289 without a value can be used to delete a variable from the
5290 environment. As long as you don't save the environment you are
5291 working with an in-memory copy. In case the Flash area containing the
5292 environment is erased by accident, a default environment is provided.
5294 Some configuration options can be set using Environment Variables.
5296 List of environment variables (most likely not complete):
5298 baudrate - see CONFIG_BAUDRATE
5300 bootdelay - see CONFIG_BOOTDELAY
5302 bootcmd - see CONFIG_BOOTCOMMAND
5304 bootargs - Boot arguments when booting an RTOS image
5306 bootfile - Name of the image to load with TFTP
5308 bootm_low - Memory range available for image processing in the bootm
5309 command can be restricted. This variable is given as
5310 a hexadecimal number and defines lowest address allowed
5311 for use by the bootm command. See also "bootm_size"
5312 environment variable. Address defined by "bootm_low" is
5313 also the base of the initial memory mapping for the Linux
5314 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5317 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5318 This variable is given as a hexadecimal number and it
5319 defines the size of the memory region starting at base
5320 address bootm_low that is accessible by the Linux kernel
5321 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5322 as the default value if it is defined, and bootm_size is
5325 bootm_size - Memory range available for image processing in the bootm
5326 command can be restricted. This variable is given as
5327 a hexadecimal number and defines the size of the region
5328 allowed for use by the bootm command. See also "bootm_low"
5329 environment variable.
5331 updatefile - Location of the software update file on a TFTP server, used
5332 by the automatic software update feature. Please refer to
5333 documentation in doc/README.update for more details.
5335 autoload - if set to "no" (any string beginning with 'n'),
5336 "bootp" will just load perform a lookup of the
5337 configuration from the BOOTP server, but not try to
5338 load any image using TFTP
5340 autostart - if set to "yes", an image loaded using the "bootp",
5341 "rarpboot", "tftpboot" or "diskboot" commands will
5342 be automatically started (by internally calling
5345 If set to "no", a standalone image passed to the
5346 "bootm" command will be copied to the load address
5347 (and eventually uncompressed), but NOT be started.
5348 This can be used to load and uncompress arbitrary
5351 fdt_high - if set this restricts the maximum address that the
5352 flattened device tree will be copied into upon boot.
5353 For example, if you have a system with 1 GB memory
5354 at physical address 0x10000000, while Linux kernel
5355 only recognizes the first 704 MB as low memory, you
5356 may need to set fdt_high as 0x3C000000 to have the
5357 device tree blob be copied to the maximum address
5358 of the 704 MB low memory, so that Linux kernel can
5359 access it during the boot procedure.
5361 If this is set to the special value 0xFFFFFFFF then
5362 the fdt will not be copied at all on boot. For this
5363 to work it must reside in writable memory, have
5364 sufficient padding on the end of it for u-boot to
5365 add the information it needs into it, and the memory
5366 must be accessible by the kernel.
5368 fdtcontroladdr- if set this is the address of the control flattened
5369 device tree used by U-Boot when CONFIG_OF_CONTROL is
5372 i2cfast - (PPC405GP|PPC405EP only)
5373 if set to 'y' configures Linux I2C driver for fast
5374 mode (400kHZ). This environment variable is used in
5375 initialization code. So, for changes to be effective
5376 it must be saved and board must be reset.
5378 initrd_high - restrict positioning of initrd images:
5379 If this variable is not set, initrd images will be
5380 copied to the highest possible address in RAM; this
5381 is usually what you want since it allows for
5382 maximum initrd size. If for some reason you want to
5383 make sure that the initrd image is loaded below the
5384 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5385 variable to a value of "no" or "off" or "0".
5386 Alternatively, you can set it to a maximum upper
5387 address to use (U-Boot will still check that it
5388 does not overwrite the U-Boot stack and data).
5390 For instance, when you have a system with 16 MB
5391 RAM, and want to reserve 4 MB from use by Linux,
5392 you can do this by adding "mem=12M" to the value of
5393 the "bootargs" variable. However, now you must make
5394 sure that the initrd image is placed in the first
5395 12 MB as well - this can be done with
5397 setenv initrd_high 00c00000
5399 If you set initrd_high to 0xFFFFFFFF, this is an
5400 indication to U-Boot that all addresses are legal
5401 for the Linux kernel, including addresses in flash
5402 memory. In this case U-Boot will NOT COPY the
5403 ramdisk at all. This may be useful to reduce the
5404 boot time on your system, but requires that this
5405 feature is supported by your Linux kernel.
5407 ipaddr - IP address; needed for tftpboot command
5409 loadaddr - Default load address for commands like "bootp",
5410 "rarpboot", "tftpboot", "loadb" or "diskboot"
5412 loads_echo - see CONFIG_LOADS_ECHO
5414 serverip - TFTP server IP address; needed for tftpboot command
5416 bootretry - see CONFIG_BOOT_RETRY_TIME
5418 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5420 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5422 ethprime - controls which interface is used first.
5424 ethact - controls which interface is currently active.
5425 For example you can do the following
5427 => setenv ethact FEC
5428 => ping 192.168.0.1 # traffic sent on FEC
5429 => setenv ethact SCC
5430 => ping 10.0.0.1 # traffic sent on SCC
5432 ethrotate - When set to "no" U-Boot does not go through all
5433 available network interfaces.
5434 It just stays at the currently selected interface.
5436 netretry - When set to "no" each network operation will
5437 either succeed or fail without retrying.
5438 When set to "once" the network operation will
5439 fail when all the available network interfaces
5440 are tried once without success.
5441 Useful on scripts which control the retry operation
5444 npe_ucode - set load address for the NPE microcode
5446 silent_linux - If set then Linux will be told to boot silently, by
5447 changing the console to be empty. If "yes" it will be
5448 made silent. If "no" it will not be made silent. If
5449 unset, then it will be made silent if the U-Boot console
5452 tftpsrcp - If this is set, the value is used for TFTP's
5455 tftpdstp - If this is set, the value is used for TFTP's UDP
5456 destination port instead of the Well Know Port 69.
5458 tftpblocksize - Block size to use for TFTP transfers; if not set,
5459 we use the TFTP server's default block size
5461 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5462 seconds, minimum value is 1000 = 1 second). Defines
5463 when a packet is considered to be lost so it has to
5464 be retransmitted. The default is 5000 = 5 seconds.
5465 Lowering this value may make downloads succeed
5466 faster in networks with high packet loss rates or
5467 with unreliable TFTP servers.
5469 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5470 unit, minimum value = 0). Defines how many timeouts
5471 can happen during a single file transfer before that
5472 transfer is aborted. The default is 10, and 0 means
5473 'no timeouts allowed'. Increasing this value may help
5474 downloads succeed with high packet loss rates, or with
5475 unreliable TFTP servers or client hardware.
5477 vlan - When set to a value < 4095 the traffic over
5478 Ethernet is encapsulated/received over 802.1q
5481 The following image location variables contain the location of images
5482 used in booting. The "Image" column gives the role of the image and is
5483 not an environment variable name. The other columns are environment
5484 variable names. "File Name" gives the name of the file on a TFTP
5485 server, "RAM Address" gives the location in RAM the image will be
5486 loaded to, and "Flash Location" gives the image's address in NOR
5487 flash or offset in NAND flash.
5489 *Note* - these variables don't have to be defined for all boards, some
5490 boards currently use other variables for these purposes, and some
5491 boards use these variables for other purposes.
5493 Image File Name RAM Address Flash Location
5494 ----- --------- ----------- --------------
5495 u-boot u-boot u-boot_addr_r u-boot_addr
5496 Linux kernel bootfile kernel_addr_r kernel_addr
5497 device tree blob fdtfile fdt_addr_r fdt_addr
5498 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5500 The following environment variables may be used and automatically
5501 updated by the network boot commands ("bootp" and "rarpboot"),
5502 depending the information provided by your boot server:
5504 bootfile - see above
5505 dnsip - IP address of your Domain Name Server
5506 dnsip2 - IP address of your secondary Domain Name Server
5507 gatewayip - IP address of the Gateway (Router) to use
5508 hostname - Target hostname
5510 netmask - Subnet Mask
5511 rootpath - Pathname of the root filesystem on the NFS server
5512 serverip - see above
5515 There are two special Environment Variables:
5517 serial# - contains hardware identification information such
5518 as type string and/or serial number
5519 ethaddr - Ethernet address
5521 These variables can be set only once (usually during manufacturing of
5522 the board). U-Boot refuses to delete or overwrite these variables
5523 once they have been set once.
5526 Further special Environment Variables:
5528 ver - Contains the U-Boot version string as printed
5529 with the "version" command. This variable is
5530 readonly (see CONFIG_VERSION_VARIABLE).
5533 Please note that changes to some configuration parameters may take
5534 only effect after the next boot (yes, that's just like Windoze :-).
5537 Callback functions for environment variables:
5538 ---------------------------------------------
5540 For some environment variables, the behavior of u-boot needs to change
5541 when their values are changed. This functionality allows functions to
5542 be associated with arbitrary variables. On creation, overwrite, or
5543 deletion, the callback will provide the opportunity for some side
5544 effect to happen or for the change to be rejected.
5546 The callbacks are named and associated with a function using the
5547 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5549 These callbacks are associated with variables in one of two ways. The
5550 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5551 in the board configuration to a string that defines a list of
5552 associations. The list must be in the following format:
5554 entry = variable_name[:callback_name]
5557 If the callback name is not specified, then the callback is deleted.
5558 Spaces are also allowed anywhere in the list.
5560 Callbacks can also be associated by defining the ".callbacks" variable
5561 with the same list format above. Any association in ".callbacks" will
5562 override any association in the static list. You can define
5563 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5564 ".callbacks" environment variable in the default or embedded environment.
5566 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5567 regular expression. This allows multiple variables to be connected to
5568 the same callback without explicitly listing them all out.
5571 Command Line Parsing:
5572 =====================
5574 There are two different command line parsers available with U-Boot:
5575 the old "simple" one, and the much more powerful "hush" shell:
5577 Old, simple command line parser:
5578 --------------------------------
5580 - supports environment variables (through setenv / saveenv commands)
5581 - several commands on one line, separated by ';'
5582 - variable substitution using "... ${name} ..." syntax
5583 - special characters ('$', ';') can be escaped by prefixing with '\',
5585 setenv bootcmd bootm \${address}
5586 - You can also escape text by enclosing in single apostrophes, for example:
5587 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5592 - similar to Bourne shell, with control structures like
5593 if...then...else...fi, for...do...done; while...do...done,
5594 until...do...done, ...
5595 - supports environment ("global") variables (through setenv / saveenv
5596 commands) and local shell variables (through standard shell syntax
5597 "name=value"); only environment variables can be used with "run"
5603 (1) If a command line (or an environment variable executed by a "run"
5604 command) contains several commands separated by semicolon, and
5605 one of these commands fails, then the remaining commands will be
5608 (2) If you execute several variables with one call to run (i. e.
5609 calling run with a list of variables as arguments), any failing
5610 command will cause "run" to terminate, i. e. the remaining
5611 variables are not executed.
5613 Note for Redundant Ethernet Interfaces:
5614 =======================================
5616 Some boards come with redundant Ethernet interfaces; U-Boot supports
5617 such configurations and is capable of automatic selection of a
5618 "working" interface when needed. MAC assignment works as follows:
5620 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5621 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5622 "eth1addr" (=>eth1), "eth2addr", ...
5624 If the network interface stores some valid MAC address (for instance
5625 in SROM), this is used as default address if there is NO correspon-
5626 ding setting in the environment; if the corresponding environment
5627 variable is set, this overrides the settings in the card; that means:
5629 o If the SROM has a valid MAC address, and there is no address in the
5630 environment, the SROM's address is used.
5632 o If there is no valid address in the SROM, and a definition in the
5633 environment exists, then the value from the environment variable is
5636 o If both the SROM and the environment contain a MAC address, and
5637 both addresses are the same, this MAC address is used.
5639 o If both the SROM and the environment contain a MAC address, and the
5640 addresses differ, the value from the environment is used and a
5643 o If neither SROM nor the environment contain a MAC address, an error
5644 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5645 a random, locally-assigned MAC is used.
5647 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5648 will be programmed into hardware as part of the initialization process. This
5649 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5650 The naming convention is as follows:
5651 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5656 U-Boot is capable of booting (and performing other auxiliary operations on)
5657 images in two formats:
5659 New uImage format (FIT)
5660 -----------------------
5662 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5663 to Flattened Device Tree). It allows the use of images with multiple
5664 components (several kernels, ramdisks, etc.), with contents protected by
5665 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5671 Old image format is based on binary files which can be basically anything,
5672 preceded by a special header; see the definitions in include/image.h for
5673 details; basically, the header defines the following image properties:
5675 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5676 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5677 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5678 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5680 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5681 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5682 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5683 * Compression Type (uncompressed, gzip, bzip2)
5689 The header is marked by a special Magic Number, and both the header
5690 and the data portions of the image are secured against corruption by
5697 Although U-Boot should support any OS or standalone application
5698 easily, the main focus has always been on Linux during the design of
5701 U-Boot includes many features that so far have been part of some
5702 special "boot loader" code within the Linux kernel. Also, any
5703 "initrd" images to be used are no longer part of one big Linux image;
5704 instead, kernel and "initrd" are separate images. This implementation
5705 serves several purposes:
5707 - the same features can be used for other OS or standalone
5708 applications (for instance: using compressed images to reduce the
5709 Flash memory footprint)
5711 - it becomes much easier to port new Linux kernel versions because
5712 lots of low-level, hardware dependent stuff are done by U-Boot
5714 - the same Linux kernel image can now be used with different "initrd"
5715 images; of course this also means that different kernel images can
5716 be run with the same "initrd". This makes testing easier (you don't
5717 have to build a new "zImage.initrd" Linux image when you just
5718 change a file in your "initrd"). Also, a field-upgrade of the
5719 software is easier now.
5725 Porting Linux to U-Boot based systems:
5726 ---------------------------------------
5728 U-Boot cannot save you from doing all the necessary modifications to
5729 configure the Linux device drivers for use with your target hardware
5730 (no, we don't intend to provide a full virtual machine interface to
5733 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5735 Just make sure your machine specific header file (for instance
5736 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5737 Information structure as we define in include/asm-<arch>/u-boot.h,
5738 and make sure that your definition of IMAP_ADDR uses the same value
5739 as your U-Boot configuration in CONFIG_SYS_IMMR.
5741 Note that U-Boot now has a driver model, a unified model for drivers.
5742 If you are adding a new driver, plumb it into driver model. If there
5743 is no uclass available, you are encouraged to create one. See
5747 Configuring the Linux kernel:
5748 -----------------------------
5750 No specific requirements for U-Boot. Make sure you have some root
5751 device (initial ramdisk, NFS) for your target system.
5754 Building a Linux Image:
5755 -----------------------
5757 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5758 not used. If you use recent kernel source, a new build target
5759 "uImage" will exist which automatically builds an image usable by
5760 U-Boot. Most older kernels also have support for a "pImage" target,
5761 which was introduced for our predecessor project PPCBoot and uses a
5762 100% compatible format.
5766 make TQM850L_defconfig
5771 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5772 encapsulate a compressed Linux kernel image with header information,
5773 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5775 * build a standard "vmlinux" kernel image (in ELF binary format):
5777 * convert the kernel into a raw binary image:
5779 ${CROSS_COMPILE}-objcopy -O binary \
5780 -R .note -R .comment \
5781 -S vmlinux linux.bin
5783 * compress the binary image:
5787 * package compressed binary image for U-Boot:
5789 mkimage -A ppc -O linux -T kernel -C gzip \
5790 -a 0 -e 0 -n "Linux Kernel Image" \
5791 -d linux.bin.gz uImage
5794 The "mkimage" tool can also be used to create ramdisk images for use
5795 with U-Boot, either separated from the Linux kernel image, or
5796 combined into one file. "mkimage" encapsulates the images with a 64
5797 byte header containing information about target architecture,
5798 operating system, image type, compression method, entry points, time
5799 stamp, CRC32 checksums, etc.
5801 "mkimage" can be called in two ways: to verify existing images and
5802 print the header information, or to build new images.
5804 In the first form (with "-l" option) mkimage lists the information
5805 contained in the header of an existing U-Boot image; this includes
5806 checksum verification:
5808 tools/mkimage -l image
5809 -l ==> list image header information
5811 The second form (with "-d" option) is used to build a U-Boot image
5812 from a "data file" which is used as image payload:
5814 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5815 -n name -d data_file image
5816 -A ==> set architecture to 'arch'
5817 -O ==> set operating system to 'os'
5818 -T ==> set image type to 'type'
5819 -C ==> set compression type 'comp'
5820 -a ==> set load address to 'addr' (hex)
5821 -e ==> set entry point to 'ep' (hex)
5822 -n ==> set image name to 'name'
5823 -d ==> use image data from 'datafile'
5825 Right now, all Linux kernels for PowerPC systems use the same load
5826 address (0x00000000), but the entry point address depends on the
5829 - 2.2.x kernels have the entry point at 0x0000000C,
5830 - 2.3.x and later kernels have the entry point at 0x00000000.
5832 So a typical call to build a U-Boot image would read:
5834 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5835 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5836 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5837 > examples/uImage.TQM850L
5838 Image Name: 2.4.4 kernel for TQM850L
5839 Created: Wed Jul 19 02:34:59 2000
5840 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5841 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5842 Load Address: 0x00000000
5843 Entry Point: 0x00000000
5845 To verify the contents of the image (or check for corruption):
5847 -> tools/mkimage -l examples/uImage.TQM850L
5848 Image Name: 2.4.4 kernel for TQM850L
5849 Created: Wed Jul 19 02:34:59 2000
5850 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5851 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5852 Load Address: 0x00000000
5853 Entry Point: 0x00000000
5855 NOTE: for embedded systems where boot time is critical you can trade
5856 speed for memory and install an UNCOMPRESSED image instead: this
5857 needs more space in Flash, but boots much faster since it does not
5858 need to be uncompressed:
5860 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5861 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5862 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5863 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5864 > examples/uImage.TQM850L-uncompressed
5865 Image Name: 2.4.4 kernel for TQM850L
5866 Created: Wed Jul 19 02:34:59 2000
5867 Image Type: PowerPC Linux Kernel Image (uncompressed)
5868 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5869 Load Address: 0x00000000
5870 Entry Point: 0x00000000
5873 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5874 when your kernel is intended to use an initial ramdisk:
5876 -> tools/mkimage -n 'Simple Ramdisk Image' \
5877 > -A ppc -O linux -T ramdisk -C gzip \
5878 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5879 Image Name: Simple Ramdisk Image
5880 Created: Wed Jan 12 14:01:50 2000
5881 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5882 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5883 Load Address: 0x00000000
5884 Entry Point: 0x00000000
5886 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5887 option performs the converse operation of the mkimage's second form (the "-d"
5888 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5891 tools/dumpimage -i image -T type -p position data_file
5892 -i ==> extract from the 'image' a specific 'data_file'
5893 -T ==> set image type to 'type'
5894 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5897 Installing a Linux Image:
5898 -------------------------
5900 To downloading a U-Boot image over the serial (console) interface,
5901 you must convert the image to S-Record format:
5903 objcopy -I binary -O srec examples/image examples/image.srec
5905 The 'objcopy' does not understand the information in the U-Boot
5906 image header, so the resulting S-Record file will be relative to
5907 address 0x00000000. To load it to a given address, you need to
5908 specify the target address as 'offset' parameter with the 'loads'
5911 Example: install the image to address 0x40100000 (which on the
5912 TQM8xxL is in the first Flash bank):
5914 => erase 40100000 401FFFFF
5920 ## Ready for S-Record download ...
5921 ~>examples/image.srec
5922 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5924 15989 15990 15991 15992
5925 [file transfer complete]
5927 ## Start Addr = 0x00000000
5930 You can check the success of the download using the 'iminfo' command;
5931 this includes a checksum verification so you can be sure no data
5932 corruption happened:
5936 ## Checking Image at 40100000 ...
5937 Image Name: 2.2.13 for initrd on TQM850L
5938 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5939 Data Size: 335725 Bytes = 327 kB = 0 MB
5940 Load Address: 00000000
5941 Entry Point: 0000000c
5942 Verifying Checksum ... OK
5948 The "bootm" command is used to boot an application that is stored in
5949 memory (RAM or Flash). In case of a Linux kernel image, the contents
5950 of the "bootargs" environment variable is passed to the kernel as
5951 parameters. You can check and modify this variable using the
5952 "printenv" and "setenv" commands:
5955 => printenv bootargs
5956 bootargs=root=/dev/ram
5958 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5960 => printenv bootargs
5961 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5964 ## Booting Linux kernel at 40020000 ...
5965 Image Name: 2.2.13 for NFS on TQM850L
5966 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5967 Data Size: 381681 Bytes = 372 kB = 0 MB
5968 Load Address: 00000000
5969 Entry Point: 0000000c
5970 Verifying Checksum ... OK
5971 Uncompressing Kernel Image ... OK
5972 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
5973 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5974 time_init: decrementer frequency = 187500000/60
5975 Calibrating delay loop... 49.77 BogoMIPS
5976 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5979 If you want to boot a Linux kernel with initial RAM disk, you pass
5980 the memory addresses of both the kernel and the initrd image (PPBCOOT
5981 format!) to the "bootm" command:
5983 => imi 40100000 40200000
5985 ## Checking Image at 40100000 ...
5986 Image Name: 2.2.13 for initrd on TQM850L
5987 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5988 Data Size: 335725 Bytes = 327 kB = 0 MB
5989 Load Address: 00000000
5990 Entry Point: 0000000c
5991 Verifying Checksum ... OK
5993 ## Checking Image at 40200000 ...
5994 Image Name: Simple Ramdisk Image
5995 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5996 Data Size: 566530 Bytes = 553 kB = 0 MB
5997 Load Address: 00000000
5998 Entry Point: 00000000
5999 Verifying Checksum ... OK
6001 => bootm 40100000 40200000
6002 ## Booting Linux kernel at 40100000 ...
6003 Image Name: 2.2.13 for initrd on TQM850L
6004 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6005 Data Size: 335725 Bytes = 327 kB = 0 MB
6006 Load Address: 00000000
6007 Entry Point: 0000000c
6008 Verifying Checksum ... OK
6009 Uncompressing Kernel Image ... OK
6010 ## Loading RAMDisk Image at 40200000 ...
6011 Image Name: Simple Ramdisk Image
6012 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6013 Data Size: 566530 Bytes = 553 kB = 0 MB
6014 Load Address: 00000000
6015 Entry Point: 00000000
6016 Verifying Checksum ... OK
6017 Loading Ramdisk ... OK
6018 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
6019 Boot arguments: root=/dev/ram
6020 time_init: decrementer frequency = 187500000/60
6021 Calibrating delay loop... 49.77 BogoMIPS
6023 RAMDISK: Compressed image found at block 0
6024 VFS: Mounted root (ext2 filesystem).
6028 Boot Linux and pass a flat device tree:
6031 First, U-Boot must be compiled with the appropriate defines. See the section
6032 titled "Linux Kernel Interface" above for a more in depth explanation. The
6033 following is an example of how to start a kernel and pass an updated
6039 oft=oftrees/mpc8540ads.dtb
6040 => tftp $oftaddr $oft
6041 Speed: 1000, full duplex
6043 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6044 Filename 'oftrees/mpc8540ads.dtb'.
6045 Load address: 0x300000
6048 Bytes transferred = 4106 (100a hex)
6049 => tftp $loadaddr $bootfile
6050 Speed: 1000, full duplex
6052 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6054 Load address: 0x200000
6055 Loading:############
6057 Bytes transferred = 1029407 (fb51f hex)
6062 => bootm $loadaddr - $oftaddr
6063 ## Booting image at 00200000 ...
6064 Image Name: Linux-2.6.17-dirty
6065 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6066 Data Size: 1029343 Bytes = 1005.2 kB
6067 Load Address: 00000000
6068 Entry Point: 00000000
6069 Verifying Checksum ... OK
6070 Uncompressing Kernel Image ... OK
6071 Booting using flat device tree at 0x300000
6072 Using MPC85xx ADS machine description
6073 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6077 More About U-Boot Image Types:
6078 ------------------------------
6080 U-Boot supports the following image types:
6082 "Standalone Programs" are directly runnable in the environment
6083 provided by U-Boot; it is expected that (if they behave
6084 well) you can continue to work in U-Boot after return from
6085 the Standalone Program.
6086 "OS Kernel Images" are usually images of some Embedded OS which
6087 will take over control completely. Usually these programs
6088 will install their own set of exception handlers, device
6089 drivers, set up the MMU, etc. - this means, that you cannot
6090 expect to re-enter U-Boot except by resetting the CPU.
6091 "RAMDisk Images" are more or less just data blocks, and their
6092 parameters (address, size) are passed to an OS kernel that is
6094 "Multi-File Images" contain several images, typically an OS
6095 (Linux) kernel image and one or more data images like
6096 RAMDisks. This construct is useful for instance when you want
6097 to boot over the network using BOOTP etc., where the boot
6098 server provides just a single image file, but you want to get
6099 for instance an OS kernel and a RAMDisk image.
6101 "Multi-File Images" start with a list of image sizes, each
6102 image size (in bytes) specified by an "uint32_t" in network
6103 byte order. This list is terminated by an "(uint32_t)0".
6104 Immediately after the terminating 0 follow the images, one by
6105 one, all aligned on "uint32_t" boundaries (size rounded up to
6106 a multiple of 4 bytes).
6108 "Firmware Images" are binary images containing firmware (like
6109 U-Boot or FPGA images) which usually will be programmed to
6112 "Script files" are command sequences that will be executed by
6113 U-Boot's command interpreter; this feature is especially
6114 useful when you configure U-Boot to use a real shell (hush)
6115 as command interpreter.
6117 Booting the Linux zImage:
6118 -------------------------
6120 On some platforms, it's possible to boot Linux zImage. This is done
6121 using the "bootz" command. The syntax of "bootz" command is the same
6122 as the syntax of "bootm" command.
6124 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6125 kernel with raw initrd images. The syntax is slightly different, the
6126 address of the initrd must be augmented by it's size, in the following
6127 format: "<initrd addres>:<initrd size>".
6133 One of the features of U-Boot is that you can dynamically load and
6134 run "standalone" applications, which can use some resources of
6135 U-Boot like console I/O functions or interrupt services.
6137 Two simple examples are included with the sources:
6142 'examples/hello_world.c' contains a small "Hello World" Demo
6143 application; it is automatically compiled when you build U-Boot.
6144 It's configured to run at address 0x00040004, so you can play with it
6148 ## Ready for S-Record download ...
6149 ~>examples/hello_world.srec
6150 1 2 3 4 5 6 7 8 9 10 11 ...
6151 [file transfer complete]
6153 ## Start Addr = 0x00040004
6155 => go 40004 Hello World! This is a test.
6156 ## Starting application at 0x00040004 ...
6167 Hit any key to exit ...
6169 ## Application terminated, rc = 0x0
6171 Another example, which demonstrates how to register a CPM interrupt
6172 handler with the U-Boot code, can be found in 'examples/timer.c'.
6173 Here, a CPM timer is set up to generate an interrupt every second.
6174 The interrupt service routine is trivial, just printing a '.'
6175 character, but this is just a demo program. The application can be
6176 controlled by the following keys:
6178 ? - print current values og the CPM Timer registers
6179 b - enable interrupts and start timer
6180 e - stop timer and disable interrupts
6181 q - quit application
6184 ## Ready for S-Record download ...
6185 ~>examples/timer.srec
6186 1 2 3 4 5 6 7 8 9 10 11 ...
6187 [file transfer complete]
6189 ## Start Addr = 0x00040004
6192 ## Starting application at 0x00040004 ...
6195 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6198 [q, b, e, ?] Set interval 1000000 us
6201 [q, b, e, ?] ........
6202 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6205 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6208 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6211 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6213 [q, b, e, ?] ...Stopping timer
6215 [q, b, e, ?] ## Application terminated, rc = 0x0
6221 Over time, many people have reported problems when trying to use the
6222 "minicom" terminal emulation program for serial download. I (wd)
6223 consider minicom to be broken, and recommend not to use it. Under
6224 Unix, I recommend to use C-Kermit for general purpose use (and
6225 especially for kermit binary protocol download ("loadb" command), and
6226 use "cu" for S-Record download ("loads" command). See
6227 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6228 for help with kermit.
6231 Nevertheless, if you absolutely want to use it try adding this
6232 configuration to your "File transfer protocols" section:
6234 Name Program Name U/D FullScr IO-Red. Multi
6235 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6236 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6242 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6243 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6245 Building requires a cross environment; it is known to work on
6246 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6247 need gmake since the Makefiles are not compatible with BSD make).
6248 Note that the cross-powerpc package does not install include files;
6249 attempting to build U-Boot will fail because <machine/ansi.h> is
6250 missing. This file has to be installed and patched manually:
6252 # cd /usr/pkg/cross/powerpc-netbsd/include
6254 # ln -s powerpc machine
6255 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6256 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6258 Native builds *don't* work due to incompatibilities between native
6259 and U-Boot include files.
6261 Booting assumes that (the first part of) the image booted is a
6262 stage-2 loader which in turn loads and then invokes the kernel
6263 proper. Loader sources will eventually appear in the NetBSD source
6264 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6265 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6268 Implementation Internals:
6269 =========================
6271 The following is not intended to be a complete description of every
6272 implementation detail. However, it should help to understand the
6273 inner workings of U-Boot and make it easier to port it to custom
6277 Initial Stack, Global Data:
6278 ---------------------------
6280 The implementation of U-Boot is complicated by the fact that U-Boot
6281 starts running out of ROM (flash memory), usually without access to
6282 system RAM (because the memory controller is not initialized yet).
6283 This means that we don't have writable Data or BSS segments, and BSS
6284 is not initialized as zero. To be able to get a C environment working
6285 at all, we have to allocate at least a minimal stack. Implementation
6286 options for this are defined and restricted by the CPU used: Some CPU
6287 models provide on-chip memory (like the IMMR area on MPC8xx and
6288 MPC826x processors), on others (parts of) the data cache can be
6289 locked as (mis-) used as memory, etc.
6291 Chris Hallinan posted a good summary of these issues to the
6292 U-Boot mailing list:
6294 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6295 From: "Chris Hallinan" <clh@net1plus.com>
6296 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6299 Correct me if I'm wrong, folks, but the way I understand it
6300 is this: Using DCACHE as initial RAM for Stack, etc, does not
6301 require any physical RAM backing up the cache. The cleverness
6302 is that the cache is being used as a temporary supply of
6303 necessary storage before the SDRAM controller is setup. It's
6304 beyond the scope of this list to explain the details, but you
6305 can see how this works by studying the cache architecture and
6306 operation in the architecture and processor-specific manuals.
6308 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6309 is another option for the system designer to use as an
6310 initial stack/RAM area prior to SDRAM being available. Either
6311 option should work for you. Using CS 4 should be fine if your
6312 board designers haven't used it for something that would
6313 cause you grief during the initial boot! It is frequently not
6316 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6317 with your processor/board/system design. The default value
6318 you will find in any recent u-boot distribution in
6319 walnut.h should work for you. I'd set it to a value larger
6320 than your SDRAM module. If you have a 64MB SDRAM module, set
6321 it above 400_0000. Just make sure your board has no resources
6322 that are supposed to respond to that address! That code in
6323 start.S has been around a while and should work as is when
6324 you get the config right.
6329 It is essential to remember this, since it has some impact on the C
6330 code for the initialization procedures:
6332 * Initialized global data (data segment) is read-only. Do not attempt
6335 * Do not use any uninitialized global data (or implicitly initialized
6336 as zero data - BSS segment) at all - this is undefined, initiali-
6337 zation is performed later (when relocating to RAM).
6339 * Stack space is very limited. Avoid big data buffers or things like
6342 Having only the stack as writable memory limits means we cannot use
6343 normal global data to share information between the code. But it
6344 turned out that the implementation of U-Boot can be greatly
6345 simplified by making a global data structure (gd_t) available to all
6346 functions. We could pass a pointer to this data as argument to _all_
6347 functions, but this would bloat the code. Instead we use a feature of
6348 the GCC compiler (Global Register Variables) to share the data: we
6349 place a pointer (gd) to the global data into a register which we
6350 reserve for this purpose.
6352 When choosing a register for such a purpose we are restricted by the
6353 relevant (E)ABI specifications for the current architecture, and by
6354 GCC's implementation.
6356 For PowerPC, the following registers have specific use:
6358 R2: reserved for system use
6359 R3-R4: parameter passing and return values
6360 R5-R10: parameter passing
6361 R13: small data area pointer
6365 (U-Boot also uses R12 as internal GOT pointer. r12
6366 is a volatile register so r12 needs to be reset when
6367 going back and forth between asm and C)
6369 ==> U-Boot will use R2 to hold a pointer to the global data
6371 Note: on PPC, we could use a static initializer (since the
6372 address of the global data structure is known at compile time),
6373 but it turned out that reserving a register results in somewhat
6374 smaller code - although the code savings are not that big (on
6375 average for all boards 752 bytes for the whole U-Boot image,
6376 624 text + 127 data).
6378 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6379 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6381 ==> U-Boot will use P3 to hold a pointer to the global data
6383 On ARM, the following registers are used:
6385 R0: function argument word/integer result
6386 R1-R3: function argument word
6387 R9: platform specific
6388 R10: stack limit (used only if stack checking is enabled)
6389 R11: argument (frame) pointer
6390 R12: temporary workspace
6393 R15: program counter
6395 ==> U-Boot will use R9 to hold a pointer to the global data
6397 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6399 On Nios II, the ABI is documented here:
6400 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6402 ==> U-Boot will use gp to hold a pointer to the global data
6404 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6405 to access small data sections, so gp is free.
6407 On NDS32, the following registers are used:
6409 R0-R1: argument/return
6411 R15: temporary register for assembler
6412 R16: trampoline register
6413 R28: frame pointer (FP)
6414 R29: global pointer (GP)
6415 R30: link register (LP)
6416 R31: stack pointer (SP)
6417 PC: program counter (PC)
6419 ==> U-Boot will use R10 to hold a pointer to the global data
6421 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6422 or current versions of GCC may "optimize" the code too much.
6427 U-Boot runs in system state and uses physical addresses, i.e. the
6428 MMU is not used either for address mapping nor for memory protection.
6430 The available memory is mapped to fixed addresses using the memory
6431 controller. In this process, a contiguous block is formed for each
6432 memory type (Flash, SDRAM, SRAM), even when it consists of several
6433 physical memory banks.
6435 U-Boot is installed in the first 128 kB of the first Flash bank (on
6436 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6437 booting and sizing and initializing DRAM, the code relocates itself
6438 to the upper end of DRAM. Immediately below the U-Boot code some
6439 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6440 configuration setting]. Below that, a structure with global Board
6441 Info data is placed, followed by the stack (growing downward).
6443 Additionally, some exception handler code is copied to the low 8 kB
6444 of DRAM (0x00000000 ... 0x00001FFF).
6446 So a typical memory configuration with 16 MB of DRAM could look like
6449 0x0000 0000 Exception Vector code
6452 0x0000 2000 Free for Application Use
6458 0x00FB FF20 Monitor Stack (Growing downward)
6459 0x00FB FFAC Board Info Data and permanent copy of global data
6460 0x00FC 0000 Malloc Arena
6463 0x00FE 0000 RAM Copy of Monitor Code
6464 ... eventually: LCD or video framebuffer
6465 ... eventually: pRAM (Protected RAM - unchanged by reset)
6466 0x00FF FFFF [End of RAM]
6469 System Initialization:
6470 ----------------------
6472 In the reset configuration, U-Boot starts at the reset entry point
6473 (on most PowerPC systems at address 0x00000100). Because of the reset
6474 configuration for CS0# this is a mirror of the on board Flash memory.
6475 To be able to re-map memory U-Boot then jumps to its link address.
6476 To be able to implement the initialization code in C, a (small!)
6477 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6478 which provide such a feature like MPC8xx or MPC8260), or in a locked
6479 part of the data cache. After that, U-Boot initializes the CPU core,
6480 the caches and the SIU.
6482 Next, all (potentially) available memory banks are mapped using a
6483 preliminary mapping. For example, we put them on 512 MB boundaries
6484 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6485 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6486 programmed for SDRAM access. Using the temporary configuration, a
6487 simple memory test is run that determines the size of the SDRAM
6490 When there is more than one SDRAM bank, and the banks are of
6491 different size, the largest is mapped first. For equal size, the first
6492 bank (CS2#) is mapped first. The first mapping is always for address
6493 0x00000000, with any additional banks following immediately to create
6494 contiguous memory starting from 0.
6496 Then, the monitor installs itself at the upper end of the SDRAM area
6497 and allocates memory for use by malloc() and for the global Board
6498 Info data; also, the exception vector code is copied to the low RAM
6499 pages, and the final stack is set up.
6501 Only after this relocation will you have a "normal" C environment;
6502 until that you are restricted in several ways, mostly because you are
6503 running from ROM, and because the code will have to be relocated to a
6507 U-Boot Porting Guide:
6508 ----------------------
6510 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6514 int main(int argc, char *argv[])
6516 sighandler_t no_more_time;
6518 signal(SIGALRM, no_more_time);
6519 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6521 if (available_money > available_manpower) {
6522 Pay consultant to port U-Boot;
6526 Download latest U-Boot source;
6528 Subscribe to u-boot mailing list;
6531 email("Hi, I am new to U-Boot, how do I get started?");
6534 Read the README file in the top level directory;
6535 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6536 Read applicable doc/*.README;
6537 Read the source, Luke;
6538 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6541 if (available_money > toLocalCurrency ($2500))
6544 Add a lot of aggravation and time;
6546 if (a similar board exists) { /* hopefully... */
6547 cp -a board/<similar> board/<myboard>
6548 cp include/configs/<similar>.h include/configs/<myboard>.h
6550 Create your own board support subdirectory;
6551 Create your own board include/configs/<myboard>.h file;
6553 Edit new board/<myboard> files
6554 Edit new include/configs/<myboard>.h
6559 Add / modify source code;
6563 email("Hi, I am having problems...");
6565 Send patch file to the U-Boot email list;
6566 if (reasonable critiques)
6567 Incorporate improvements from email list code review;
6569 Defend code as written;
6575 void no_more_time (int sig)
6584 All contributions to U-Boot should conform to the Linux kernel
6585 coding style; see the file "Documentation/CodingStyle" and the script
6586 "scripts/Lindent" in your Linux kernel source directory.
6588 Source files originating from a different project (for example the
6589 MTD subsystem) are generally exempt from these guidelines and are not
6590 reformatted to ease subsequent migration to newer versions of those
6593 Please note that U-Boot is implemented in C (and to some small parts in
6594 Assembler); no C++ is used, so please do not use C++ style comments (//)
6597 Please also stick to the following formatting rules:
6598 - remove any trailing white space
6599 - use TAB characters for indentation and vertical alignment, not spaces
6600 - make sure NOT to use DOS '\r\n' line feeds
6601 - do not add more than 2 consecutive empty lines to source files
6602 - do not add trailing empty lines to source files
6604 Submissions which do not conform to the standards may be returned
6605 with a request to reformat the changes.
6611 Since the number of patches for U-Boot is growing, we need to
6612 establish some rules. Submissions which do not conform to these rules
6613 may be rejected, even when they contain important and valuable stuff.
6615 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6617 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6618 see http://lists.denx.de/mailman/listinfo/u-boot
6620 When you send a patch, please include the following information with
6623 * For bug fixes: a description of the bug and how your patch fixes
6624 this bug. Please try to include a way of demonstrating that the
6625 patch actually fixes something.
6627 * For new features: a description of the feature and your
6630 * A CHANGELOG entry as plaintext (separate from the patch)
6632 * For major contributions, your entry to the CREDITS file
6634 * When you add support for a new board, don't forget to add a
6635 maintainer e-mail address to the boards.cfg file, too.
6637 * If your patch adds new configuration options, don't forget to
6638 document these in the README file.
6640 * The patch itself. If you are using git (which is *strongly*
6641 recommended) you can easily generate the patch using the
6642 "git format-patch". If you then use "git send-email" to send it to
6643 the U-Boot mailing list, you will avoid most of the common problems
6644 with some other mail clients.
6646 If you cannot use git, use "diff -purN OLD NEW". If your version of
6647 diff does not support these options, then get the latest version of
6650 The current directory when running this command shall be the parent
6651 directory of the U-Boot source tree (i. e. please make sure that
6652 your patch includes sufficient directory information for the
6655 We prefer patches as plain text. MIME attachments are discouraged,
6656 and compressed attachments must not be used.
6658 * If one logical set of modifications affects or creates several
6659 files, all these changes shall be submitted in a SINGLE patch file.
6661 * Changesets that contain different, unrelated modifications shall be
6662 submitted as SEPARATE patches, one patch per changeset.
6667 * Before sending the patch, run the MAKEALL script on your patched
6668 source tree and make sure that no errors or warnings are reported
6669 for any of the boards.
6671 * Keep your modifications to the necessary minimum: A patch
6672 containing several unrelated changes or arbitrary reformats will be
6673 returned with a request to re-formatting / split it.
6675 * If you modify existing code, make sure that your new code does not
6676 add to the memory footprint of the code ;-) Small is beautiful!
6677 When adding new features, these should compile conditionally only
6678 (using #ifdef), and the resulting code with the new feature
6679 disabled must not need more memory than the old code without your
6682 * Remember that there is a size limit of 100 kB per message on the
6683 u-boot mailing list. Bigger patches will be moderated. If they are
6684 reasonable and not too big, they will be acknowledged. But patches
6685 bigger than the size limit should be avoided.
projects / u-boot / blob