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. rx51_kp_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.
1770 See Kconfig help for available keyboard drivers.
1774 Define this to enable a custom keyboard support.
1775 This simply calls drv_keyboard_init() which must be
1776 defined in your board-specific files. This option is deprecated
1777 and is only used by novena. For new boards, use driver model
1783 Define this to enable video support (for output to
1786 CONFIG_VIDEO_CT69000
1788 Enable Chips & Technologies 69000 Video chip
1790 CONFIG_VIDEO_SMI_LYNXEM
1791 Enable Silicon Motion SMI 712/710/810 Video chip. The
1792 video output is selected via environment 'videoout'
1793 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1796 For the CT69000 and SMI_LYNXEM drivers, videomode is
1797 selected via environment 'videomode'. Two different ways
1799 - "videomode=num" 'num' is a standard LiLo mode numbers.
1800 Following standard modes are supported (* is default):
1802 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1803 -------------+---------------------------------------------
1804 8 bits | 0x301* 0x303 0x305 0x161 0x307
1805 15 bits | 0x310 0x313 0x316 0x162 0x319
1806 16 bits | 0x311 0x314 0x317 0x163 0x31A
1807 24 bits | 0x312 0x315 0x318 ? 0x31B
1808 -------------+---------------------------------------------
1809 (i.e. setenv videomode 317; saveenv; reset;)
1811 - "videomode=bootargs" all the video parameters are parsed
1812 from the bootargs. (See drivers/video/videomodes.c)
1815 CONFIG_VIDEO_SED13806
1816 Enable Epson SED13806 driver. This driver supports 8bpp
1817 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1818 or CONFIG_VIDEO_SED13806_16BPP
1821 Enable the Freescale DIU video driver. Reference boards for
1822 SOCs that have a DIU should define this macro to enable DIU
1823 support, and should also define these other macros:
1829 CONFIG_VIDEO_SW_CURSOR
1830 CONFIG_VGA_AS_SINGLE_DEVICE
1832 CONFIG_VIDEO_BMP_LOGO
1834 The DIU driver will look for the 'video-mode' environment
1835 variable, and if defined, enable the DIU as a console during
1836 boot. See the documentation file README.video for a
1837 description of this variable.
1839 - LCD Support: CONFIG_LCD
1841 Define this to enable LCD support (for output to LCD
1842 display); also select one of the supported displays
1843 by defining one of these:
1847 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1849 CONFIG_NEC_NL6448AC33:
1851 NEC NL6448AC33-18. Active, color, single scan.
1853 CONFIG_NEC_NL6448BC20
1855 NEC NL6448BC20-08. 6.5", 640x480.
1856 Active, color, single scan.
1858 CONFIG_NEC_NL6448BC33_54
1860 NEC NL6448BC33-54. 10.4", 640x480.
1861 Active, color, single scan.
1865 Sharp 320x240. Active, color, single scan.
1866 It isn't 16x9, and I am not sure what it is.
1868 CONFIG_SHARP_LQ64D341
1870 Sharp LQ64D341 display, 640x480.
1871 Active, color, single scan.
1875 HLD1045 display, 640x480.
1876 Active, color, single scan.
1880 Optrex CBL50840-2 NF-FW 99 22 M5
1882 Hitachi LMG6912RPFC-00T
1886 320x240. Black & white.
1888 Normally display is black on white background; define
1889 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1891 CONFIG_LCD_ALIGNMENT
1893 Normally the LCD is page-aligned (typically 4KB). If this is
1894 defined then the LCD will be aligned to this value instead.
1895 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1896 here, since it is cheaper to change data cache settings on
1897 a per-section basis.
1899 CONFIG_CONSOLE_SCROLL_LINES
1901 When the console need to be scrolled, this is the number of
1902 lines to scroll by. It defaults to 1. Increasing this makes
1903 the console jump but can help speed up operation when scrolling
1908 Sometimes, for example if the display is mounted in portrait
1909 mode or even if it's mounted landscape but rotated by 180degree,
1910 we need to rotate our content of the display relative to the
1911 framebuffer, so that user can read the messages which are
1913 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1914 initialized with a given rotation from "vl_rot" out of
1915 "vidinfo_t" which is provided by the board specific code.
1916 The value for vl_rot is coded as following (matching to
1917 fbcon=rotate:<n> linux-kernel commandline):
1918 0 = no rotation respectively 0 degree
1919 1 = 90 degree rotation
1920 2 = 180 degree rotation
1921 3 = 270 degree rotation
1923 If CONFIG_LCD_ROTATION is not defined, the console will be
1924 initialized with 0degree rotation.
1928 Support drawing of RLE8-compressed bitmaps on the LCD.
1932 Enables an 'i2c edid' command which can read EDID
1933 information over I2C from an attached LCD display.
1935 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1937 If this option is set, the environment is checked for
1938 a variable "splashimage". If found, the usual display
1939 of logo, copyright and system information on the LCD
1940 is suppressed and the BMP image at the address
1941 specified in "splashimage" is loaded instead. The
1942 console is redirected to the "nulldev", too. This
1943 allows for a "silent" boot where a splash screen is
1944 loaded very quickly after power-on.
1946 CONFIG_SPLASHIMAGE_GUARD
1948 If this option is set, then U-Boot will prevent the environment
1949 variable "splashimage" from being set to a problematic address
1950 (see README.displaying-bmps).
1951 This option is useful for targets where, due to alignment
1952 restrictions, an improperly aligned BMP image will cause a data
1953 abort. If you think you will not have problems with unaligned
1954 accesses (for example because your toolchain prevents them)
1955 there is no need to set this option.
1957 CONFIG_SPLASH_SCREEN_ALIGN
1959 If this option is set the splash image can be freely positioned
1960 on the screen. Environment variable "splashpos" specifies the
1961 position as "x,y". If a positive number is given it is used as
1962 number of pixel from left/top. If a negative number is given it
1963 is used as number of pixel from right/bottom. You can also
1964 specify 'm' for centering the image.
1967 setenv splashpos m,m
1968 => image at center of screen
1970 setenv splashpos 30,20
1971 => image at x = 30 and y = 20
1973 setenv splashpos -10,m
1974 => vertically centered image
1975 at x = dspWidth - bmpWidth - 9
1977 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1979 If this option is set, additionally to standard BMP
1980 images, gzipped BMP images can be displayed via the
1981 splashscreen support or the bmp command.
1983 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1985 If this option is set, 8-bit RLE compressed BMP images
1986 can be displayed via the splashscreen support or the
1989 - Do compressing for memory range:
1992 If this option is set, it would use zlib deflate method
1993 to compress the specified memory at its best effort.
1995 - Compression support:
1998 Enabled by default to support gzip compressed images.
2002 If this option is set, support for bzip2 compressed
2003 images is included. If not, only uncompressed and gzip
2004 compressed images are supported.
2006 NOTE: the bzip2 algorithm requires a lot of RAM, so
2007 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2012 If this option is set, support for lzma compressed
2015 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2016 requires an amount of dynamic memory that is given by the
2019 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2021 Where lc and lp stand for, respectively, Literal context bits
2022 and Literal pos bits.
2024 This value is upper-bounded by 14MB in the worst case. Anyway,
2025 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2026 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2027 a very small buffer.
2029 Use the lzmainfo tool to determinate the lc and lp values and
2030 then calculate the amount of needed dynamic memory (ensuring
2031 the appropriate CONFIG_SYS_MALLOC_LEN value).
2035 If this option is set, support for LZO compressed images
2041 The address of PHY on MII bus.
2043 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2045 The clock frequency of the MII bus
2049 If this option is set, support for speed/duplex
2050 detection of gigabit PHY is included.
2052 CONFIG_PHY_RESET_DELAY
2054 Some PHY like Intel LXT971A need extra delay after
2055 reset before any MII register access is possible.
2056 For such PHY, set this option to the usec delay
2057 required. (minimum 300usec for LXT971A)
2059 CONFIG_PHY_CMD_DELAY (ppc4xx)
2061 Some PHY like Intel LXT971A need extra delay after
2062 command issued before MII status register can be read
2067 Define a default value for the IP address to use for
2068 the default Ethernet interface, in case this is not
2069 determined through e.g. bootp.
2070 (Environment variable "ipaddr")
2072 - Server IP address:
2075 Defines a default value for the IP address of a TFTP
2076 server to contact when using the "tftboot" command.
2077 (Environment variable "serverip")
2079 CONFIG_KEEP_SERVERADDR
2081 Keeps the server's MAC address, in the env 'serveraddr'
2082 for passing to bootargs (like Linux's netconsole option)
2084 - Gateway IP address:
2087 Defines a default value for the IP address of the
2088 default router where packets to other networks are
2090 (Environment variable "gatewayip")
2095 Defines a default value for the subnet mask (or
2096 routing prefix) which is used to determine if an IP
2097 address belongs to the local subnet or needs to be
2098 forwarded through a router.
2099 (Environment variable "netmask")
2101 - Multicast TFTP Mode:
2104 Defines whether you want to support multicast TFTP as per
2105 rfc-2090; for example to work with atftp. Lets lots of targets
2106 tftp down the same boot image concurrently. Note: the Ethernet
2107 driver in use must provide a function: mcast() to join/leave a
2110 - BOOTP Recovery Mode:
2111 CONFIG_BOOTP_RANDOM_DELAY
2113 If you have many targets in a network that try to
2114 boot using BOOTP, you may want to avoid that all
2115 systems send out BOOTP requests at precisely the same
2116 moment (which would happen for instance at recovery
2117 from a power failure, when all systems will try to
2118 boot, thus flooding the BOOTP server. Defining
2119 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2120 inserted before sending out BOOTP requests. The
2121 following delays are inserted then:
2123 1st BOOTP request: delay 0 ... 1 sec
2124 2nd BOOTP request: delay 0 ... 2 sec
2125 3rd BOOTP request: delay 0 ... 4 sec
2127 BOOTP requests: delay 0 ... 8 sec
2129 CONFIG_BOOTP_ID_CACHE_SIZE
2131 BOOTP packets are uniquely identified using a 32-bit ID. The
2132 server will copy the ID from client requests to responses and
2133 U-Boot will use this to determine if it is the destination of
2134 an incoming response. Some servers will check that addresses
2135 aren't in use before handing them out (usually using an ARP
2136 ping) and therefore take up to a few hundred milliseconds to
2137 respond. Network congestion may also influence the time it
2138 takes for a response to make it back to the client. If that
2139 time is too long, U-Boot will retransmit requests. In order
2140 to allow earlier responses to still be accepted after these
2141 retransmissions, U-Boot's BOOTP client keeps a small cache of
2142 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2143 cache. The default is to keep IDs for up to four outstanding
2144 requests. Increasing this will allow U-Boot to accept offers
2145 from a BOOTP client in networks with unusually high latency.
2147 - DHCP Advanced Options:
2148 You can fine tune the DHCP functionality by defining
2149 CONFIG_BOOTP_* symbols:
2151 CONFIG_BOOTP_SUBNETMASK
2152 CONFIG_BOOTP_GATEWAY
2153 CONFIG_BOOTP_HOSTNAME
2154 CONFIG_BOOTP_NISDOMAIN
2155 CONFIG_BOOTP_BOOTPATH
2156 CONFIG_BOOTP_BOOTFILESIZE
2159 CONFIG_BOOTP_SEND_HOSTNAME
2160 CONFIG_BOOTP_NTPSERVER
2161 CONFIG_BOOTP_TIMEOFFSET
2162 CONFIG_BOOTP_VENDOREX
2163 CONFIG_BOOTP_MAY_FAIL
2165 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2166 environment variable, not the BOOTP server.
2168 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2169 after the configured retry count, the call will fail
2170 instead of starting over. This can be used to fail over
2171 to Link-local IP address configuration if the DHCP server
2174 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2175 serverip from a DHCP server, it is possible that more
2176 than one DNS serverip is offered to the client.
2177 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2178 serverip will be stored in the additional environment
2179 variable "dnsip2". The first DNS serverip is always
2180 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2183 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2184 to do a dynamic update of a DNS server. To do this, they
2185 need the hostname of the DHCP requester.
2186 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2187 of the "hostname" environment variable is passed as
2188 option 12 to the DHCP server.
2190 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2192 A 32bit value in microseconds for a delay between
2193 receiving a "DHCP Offer" and sending the "DHCP Request".
2194 This fixes a problem with certain DHCP servers that don't
2195 respond 100% of the time to a "DHCP request". E.g. On an
2196 AT91RM9200 processor running at 180MHz, this delay needed
2197 to be *at least* 15,000 usec before a Windows Server 2003
2198 DHCP server would reply 100% of the time. I recommend at
2199 least 50,000 usec to be safe. The alternative is to hope
2200 that one of the retries will be successful but note that
2201 the DHCP timeout and retry process takes a longer than
2204 - Link-local IP address negotiation:
2205 Negotiate with other link-local clients on the local network
2206 for an address that doesn't require explicit configuration.
2207 This is especially useful if a DHCP server cannot be guaranteed
2208 to exist in all environments that the device must operate.
2210 See doc/README.link-local for more information.
2213 CONFIG_CDP_DEVICE_ID
2215 The device id used in CDP trigger frames.
2217 CONFIG_CDP_DEVICE_ID_PREFIX
2219 A two character string which is prefixed to the MAC address
2224 A printf format string which contains the ascii name of
2225 the port. Normally is set to "eth%d" which sets
2226 eth0 for the first Ethernet, eth1 for the second etc.
2228 CONFIG_CDP_CAPABILITIES
2230 A 32bit integer which indicates the device capabilities;
2231 0x00000010 for a normal host which does not forwards.
2235 An ascii string containing the version of the software.
2239 An ascii string containing the name of the platform.
2243 A 32bit integer sent on the trigger.
2245 CONFIG_CDP_POWER_CONSUMPTION
2247 A 16bit integer containing the power consumption of the
2248 device in .1 of milliwatts.
2250 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2252 A byte containing the id of the VLAN.
2254 - Status LED: CONFIG_STATUS_LED
2256 Several configurations allow to display the current
2257 status using a LED. For instance, the LED will blink
2258 fast while running U-Boot code, stop blinking as
2259 soon as a reply to a BOOTP request was received, and
2260 start blinking slow once the Linux kernel is running
2261 (supported by a status LED driver in the Linux
2262 kernel). Defining CONFIG_STATUS_LED enables this
2268 The status LED can be connected to a GPIO pin.
2269 In such cases, the gpio_led driver can be used as a
2270 status LED backend implementation. Define CONFIG_GPIO_LED
2271 to include the gpio_led driver in the U-Boot binary.
2273 CONFIG_GPIO_LED_INVERTED_TABLE
2274 Some GPIO connected LEDs may have inverted polarity in which
2275 case the GPIO high value corresponds to LED off state and
2276 GPIO low value corresponds to LED on state.
2277 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2278 with a list of GPIO LEDs that have inverted polarity.
2280 - CAN Support: CONFIG_CAN_DRIVER
2282 Defining CONFIG_CAN_DRIVER enables CAN driver support
2283 on those systems that support this (optional)
2284 feature, like the TQM8xxL modules.
2286 - I2C Support: CONFIG_SYS_I2C
2288 This enable the NEW i2c subsystem, and will allow you to use
2289 i2c commands at the u-boot command line (as long as you set
2290 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2291 based realtime clock chips or other i2c devices. See
2292 common/cmd_i2c.c for a description of the command line
2295 ported i2c driver to the new framework:
2296 - drivers/i2c/soft_i2c.c:
2297 - activate first bus with CONFIG_SYS_I2C_SOFT define
2298 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2299 for defining speed and slave address
2300 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2301 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2302 for defining speed and slave address
2303 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2304 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2305 for defining speed and slave address
2306 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2307 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2308 for defining speed and slave address
2310 - drivers/i2c/fsl_i2c.c:
2311 - activate i2c driver with CONFIG_SYS_I2C_FSL
2312 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2313 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2314 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2316 - If your board supports a second fsl i2c bus, define
2317 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2318 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2319 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2322 - drivers/i2c/tegra_i2c.c:
2323 - activate this driver with CONFIG_SYS_I2C_TEGRA
2324 - This driver adds 4 i2c buses with a fix speed from
2325 100000 and the slave addr 0!
2327 - drivers/i2c/ppc4xx_i2c.c
2328 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2329 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2330 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2332 - drivers/i2c/i2c_mxc.c
2333 - activate this driver with CONFIG_SYS_I2C_MXC
2334 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2335 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2336 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2337 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2338 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2339 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2340 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2341 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2342 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2343 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2344 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2345 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2346 If those defines are not set, default value is 100000
2347 for speed, and 0 for slave.
2349 - drivers/i2c/rcar_i2c.c:
2350 - activate this driver with CONFIG_SYS_I2C_RCAR
2351 - This driver adds 4 i2c buses
2353 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2354 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2355 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2356 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2357 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2358 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2359 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2360 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2361 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2363 - drivers/i2c/sh_i2c.c:
2364 - activate this driver with CONFIG_SYS_I2C_SH
2365 - This driver adds from 2 to 5 i2c buses
2367 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2368 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2369 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2370 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2371 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2372 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2373 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2374 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2375 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2376 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2377 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2378 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2379 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2381 - drivers/i2c/omap24xx_i2c.c
2382 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2383 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2384 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2385 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2386 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2387 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2388 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2389 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2390 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2391 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2392 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2394 - drivers/i2c/zynq_i2c.c
2395 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2396 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2397 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2399 - drivers/i2c/s3c24x0_i2c.c:
2400 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2401 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2402 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2403 with a fix speed from 100000 and the slave addr 0!
2405 - drivers/i2c/ihs_i2c.c
2406 - activate this driver with CONFIG_SYS_I2C_IHS
2407 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2408 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2409 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2410 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2411 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2412 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2413 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2414 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2415 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2416 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2417 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2418 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2419 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2420 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2421 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2422 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2423 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2424 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2425 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2426 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2427 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2431 CONFIG_SYS_NUM_I2C_BUSES
2432 Hold the number of i2c buses you want to use. If you
2433 don't use/have i2c muxes on your i2c bus, this
2434 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2437 CONFIG_SYS_I2C_DIRECT_BUS
2438 define this, if you don't use i2c muxes on your hardware.
2439 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2442 CONFIG_SYS_I2C_MAX_HOPS
2443 define how many muxes are maximal consecutively connected
2444 on one i2c bus. If you not use i2c muxes, omit this
2447 CONFIG_SYS_I2C_BUSES
2448 hold a list of buses you want to use, only used if
2449 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2450 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2451 CONFIG_SYS_NUM_I2C_BUSES = 9:
2453 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2454 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2455 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2456 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2457 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2458 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2459 {1, {I2C_NULL_HOP}}, \
2460 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2461 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2465 bus 0 on adapter 0 without a mux
2466 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2467 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2468 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2469 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2470 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2471 bus 6 on adapter 1 without a mux
2472 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2473 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2475 If you do not have i2c muxes on your board, omit this define.
2477 - Legacy I2C Support: CONFIG_HARD_I2C
2479 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2480 provides the following compelling advantages:
2482 - more than one i2c adapter is usable
2483 - approved multibus support
2484 - better i2c mux support
2486 ** Please consider updating your I2C driver now. **
2488 These enable legacy I2C serial bus commands. Defining
2489 CONFIG_HARD_I2C will include the appropriate I2C driver
2490 for the selected CPU.
2492 This will allow you to use i2c commands at the u-boot
2493 command line (as long as you set CONFIG_CMD_I2C in
2494 CONFIG_COMMANDS) and communicate with i2c based realtime
2495 clock chips. See common/cmd_i2c.c for a description of the
2496 command line interface.
2498 CONFIG_HARD_I2C selects a hardware I2C controller.
2500 There are several other quantities that must also be
2501 defined when you define CONFIG_HARD_I2C.
2503 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2504 to be the frequency (in Hz) at which you wish your i2c bus
2505 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2506 the CPU's i2c node address).
2508 Now, the u-boot i2c code for the mpc8xx
2509 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2510 and so its address should therefore be cleared to 0 (See,
2511 eg, MPC823e User's Manual p.16-473). So, set
2512 CONFIG_SYS_I2C_SLAVE to 0.
2514 CONFIG_SYS_I2C_INIT_MPC5XXX
2516 When a board is reset during an i2c bus transfer
2517 chips might think that the current transfer is still
2518 in progress. Reset the slave devices by sending start
2519 commands until the slave device responds.
2521 That's all that's required for CONFIG_HARD_I2C.
2523 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2524 then the following macros need to be defined (examples are
2525 from include/configs/lwmon.h):
2529 (Optional). Any commands necessary to enable the I2C
2530 controller or configure ports.
2532 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2536 (Only for MPC8260 CPU). The I/O port to use (the code
2537 assumes both bits are on the same port). Valid values
2538 are 0..3 for ports A..D.
2542 The code necessary to make the I2C data line active
2543 (driven). If the data line is open collector, this
2546 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2550 The code necessary to make the I2C data line tri-stated
2551 (inactive). If the data line is open collector, this
2554 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2558 Code that returns true if the I2C data line is high,
2561 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2565 If <bit> is true, sets the I2C data line high. If it
2566 is false, it clears it (low).
2568 eg: #define I2C_SDA(bit) \
2569 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2570 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2574 If <bit> is true, sets the I2C clock line high. If it
2575 is false, it clears it (low).
2577 eg: #define I2C_SCL(bit) \
2578 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2579 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2583 This delay is invoked four times per clock cycle so this
2584 controls the rate of data transfer. The data rate thus
2585 is 1 / (I2C_DELAY * 4). Often defined to be something
2588 #define I2C_DELAY udelay(2)
2590 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2592 If your arch supports the generic GPIO framework (asm/gpio.h),
2593 then you may alternatively define the two GPIOs that are to be
2594 used as SCL / SDA. Any of the previous I2C_xxx macros will
2595 have GPIO-based defaults assigned to them as appropriate.
2597 You should define these to the GPIO value as given directly to
2598 the generic GPIO functions.
2600 CONFIG_SYS_I2C_INIT_BOARD
2602 When a board is reset during an i2c bus transfer
2603 chips might think that the current transfer is still
2604 in progress. On some boards it is possible to access
2605 the i2c SCLK line directly, either by using the
2606 processor pin as a GPIO or by having a second pin
2607 connected to the bus. If this option is defined a
2608 custom i2c_init_board() routine in boards/xxx/board.c
2609 is run early in the boot sequence.
2611 CONFIG_SYS_I2C_BOARD_LATE_INIT
2613 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2614 defined a custom i2c_board_late_init() routine in
2615 boards/xxx/board.c is run AFTER the operations in i2c_init()
2616 is completed. This callpoint can be used to unreset i2c bus
2617 using CPU i2c controller register accesses for CPUs whose i2c
2618 controller provide such a method. It is called at the end of
2619 i2c_init() to allow i2c_init operations to setup the i2c bus
2620 controller on the CPU (e.g. setting bus speed & slave address).
2622 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2624 This option enables configuration of bi_iic_fast[] flags
2625 in u-boot bd_info structure based on u-boot environment
2626 variable "i2cfast". (see also i2cfast)
2628 CONFIG_I2C_MULTI_BUS
2630 This option allows the use of multiple I2C buses, each of which
2631 must have a controller. At any point in time, only one bus is
2632 active. To switch to a different bus, use the 'i2c dev' command.
2633 Note that bus numbering is zero-based.
2635 CONFIG_SYS_I2C_NOPROBES
2637 This option specifies a list of I2C devices that will be skipped
2638 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2639 is set, specify a list of bus-device pairs. Otherwise, specify
2640 a 1D array of device addresses
2643 #undef CONFIG_I2C_MULTI_BUS
2644 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2646 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2648 #define CONFIG_I2C_MULTI_BUS
2649 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2651 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2653 CONFIG_SYS_SPD_BUS_NUM
2655 If defined, then this indicates the I2C bus number for DDR SPD.
2656 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2658 CONFIG_SYS_RTC_BUS_NUM
2660 If defined, then this indicates the I2C bus number for the RTC.
2661 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2663 CONFIG_SYS_DTT_BUS_NUM
2665 If defined, then this indicates the I2C bus number for the DTT.
2666 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2668 CONFIG_SYS_I2C_DTT_ADDR:
2670 If defined, specifies the I2C address of the DTT device.
2671 If not defined, then U-Boot uses predefined value for
2672 specified DTT device.
2674 CONFIG_SOFT_I2C_READ_REPEATED_START
2676 defining this will force the i2c_read() function in
2677 the soft_i2c driver to perform an I2C repeated start
2678 between writing the address pointer and reading the
2679 data. If this define is omitted the default behaviour
2680 of doing a stop-start sequence will be used. Most I2C
2681 devices can use either method, but some require one or
2684 - SPI Support: CONFIG_SPI
2686 Enables SPI driver (so far only tested with
2687 SPI EEPROM, also an instance works with Crystal A/D and
2688 D/As on the SACSng board)
2692 Enables the driver for SPI controller on SuperH. Currently
2693 only SH7757 is supported.
2697 Enables a software (bit-bang) SPI driver rather than
2698 using hardware support. This is a general purpose
2699 driver that only requires three general I/O port pins
2700 (two outputs, one input) to function. If this is
2701 defined, the board configuration must define several
2702 SPI configuration items (port pins to use, etc). For
2703 an example, see include/configs/sacsng.h.
2707 Enables a hardware SPI driver for general-purpose reads
2708 and writes. As with CONFIG_SOFT_SPI, the board configuration
2709 must define a list of chip-select function pointers.
2710 Currently supported on some MPC8xxx processors. For an
2711 example, see include/configs/mpc8349emds.h.
2715 Enables the driver for the SPI controllers on i.MX and MXC
2716 SoCs. Currently i.MX31/35/51 are supported.
2718 CONFIG_SYS_SPI_MXC_WAIT
2719 Timeout for waiting until spi transfer completed.
2720 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2722 - FPGA Support: CONFIG_FPGA
2724 Enables FPGA subsystem.
2726 CONFIG_FPGA_<vendor>
2728 Enables support for specific chip vendors.
2731 CONFIG_FPGA_<family>
2733 Enables support for FPGA family.
2734 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2738 Specify the number of FPGA devices to support.
2740 CONFIG_CMD_FPGA_LOADMK
2742 Enable support for fpga loadmk command
2744 CONFIG_CMD_FPGA_LOADP
2746 Enable support for fpga loadp command - load partial bitstream
2748 CONFIG_CMD_FPGA_LOADBP
2750 Enable support for fpga loadbp command - load partial bitstream
2753 CONFIG_SYS_FPGA_PROG_FEEDBACK
2755 Enable printing of hash marks during FPGA configuration.
2757 CONFIG_SYS_FPGA_CHECK_BUSY
2759 Enable checks on FPGA configuration interface busy
2760 status by the configuration function. This option
2761 will require a board or device specific function to
2766 If defined, a function that provides delays in the FPGA
2767 configuration driver.
2769 CONFIG_SYS_FPGA_CHECK_CTRLC
2770 Allow Control-C to interrupt FPGA configuration
2772 CONFIG_SYS_FPGA_CHECK_ERROR
2774 Check for configuration errors during FPGA bitfile
2775 loading. For example, abort during Virtex II
2776 configuration if the INIT_B line goes low (which
2777 indicated a CRC error).
2779 CONFIG_SYS_FPGA_WAIT_INIT
2781 Maximum time to wait for the INIT_B line to de-assert
2782 after PROB_B has been de-asserted during a Virtex II
2783 FPGA configuration sequence. The default time is 500
2786 CONFIG_SYS_FPGA_WAIT_BUSY
2788 Maximum time to wait for BUSY to de-assert during
2789 Virtex II FPGA configuration. The default is 5 ms.
2791 CONFIG_SYS_FPGA_WAIT_CONFIG
2793 Time to wait after FPGA configuration. The default is
2796 - Configuration Management:
2799 Some SoCs need special image types (e.g. U-Boot binary
2800 with a special header) as build targets. By defining
2801 CONFIG_BUILD_TARGET in the SoC / board header, this
2802 special image will be automatically built upon calling
2807 If defined, this string will be added to the U-Boot
2808 version information (U_BOOT_VERSION)
2810 - Vendor Parameter Protection:
2812 U-Boot considers the values of the environment
2813 variables "serial#" (Board Serial Number) and
2814 "ethaddr" (Ethernet Address) to be parameters that
2815 are set once by the board vendor / manufacturer, and
2816 protects these variables from casual modification by
2817 the user. Once set, these variables are read-only,
2818 and write or delete attempts are rejected. You can
2819 change this behaviour:
2821 If CONFIG_ENV_OVERWRITE is #defined in your config
2822 file, the write protection for vendor parameters is
2823 completely disabled. Anybody can change or delete
2826 Alternatively, if you define _both_ an ethaddr in the
2827 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2828 Ethernet address is installed in the environment,
2829 which can be changed exactly ONCE by the user. [The
2830 serial# is unaffected by this, i. e. it remains
2833 The same can be accomplished in a more flexible way
2834 for any variable by configuring the type of access
2835 to allow for those variables in the ".flags" variable
2836 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2841 Define this variable to enable the reservation of
2842 "protected RAM", i. e. RAM which is not overwritten
2843 by U-Boot. Define CONFIG_PRAM to hold the number of
2844 kB you want to reserve for pRAM. You can overwrite
2845 this default value by defining an environment
2846 variable "pram" to the number of kB you want to
2847 reserve. Note that the board info structure will
2848 still show the full amount of RAM. If pRAM is
2849 reserved, a new environment variable "mem" will
2850 automatically be defined to hold the amount of
2851 remaining RAM in a form that can be passed as boot
2852 argument to Linux, for instance like that:
2854 setenv bootargs ... mem=\${mem}
2857 This way you can tell Linux not to use this memory,
2858 either, which results in a memory region that will
2859 not be affected by reboots.
2861 *WARNING* If your board configuration uses automatic
2862 detection of the RAM size, you must make sure that
2863 this memory test is non-destructive. So far, the
2864 following board configurations are known to be
2867 IVMS8, IVML24, SPD8xx, TQM8xxL,
2868 HERMES, IP860, RPXlite, LWMON,
2871 - Access to physical memory region (> 4GB)
2872 Some basic support is provided for operations on memory not
2873 normally accessible to U-Boot - e.g. some architectures
2874 support access to more than 4GB of memory on 32-bit
2875 machines using physical address extension or similar.
2876 Define CONFIG_PHYSMEM to access this basic support, which
2877 currently only supports clearing the memory.
2882 Define this variable to stop the system in case of a
2883 fatal error, so that you have to reset it manually.
2884 This is probably NOT a good idea for an embedded
2885 system where you want the system to reboot
2886 automatically as fast as possible, but it may be
2887 useful during development since you can try to debug
2888 the conditions that lead to the situation.
2890 CONFIG_NET_RETRY_COUNT
2892 This variable defines the number of retries for
2893 network operations like ARP, RARP, TFTP, or BOOTP
2894 before giving up the operation. If not defined, a
2895 default value of 5 is used.
2899 Timeout waiting for an ARP reply in milliseconds.
2903 Timeout in milliseconds used in NFS protocol.
2904 If you encounter "ERROR: Cannot umount" in nfs command,
2905 try longer timeout such as
2906 #define CONFIG_NFS_TIMEOUT 10000UL
2908 - Command Interpreter:
2909 CONFIG_AUTO_COMPLETE
2911 Enable auto completion of commands using TAB.
2913 CONFIG_SYS_PROMPT_HUSH_PS2
2915 This defines the secondary prompt string, which is
2916 printed when the command interpreter needs more input
2917 to complete a command. Usually "> ".
2921 In the current implementation, the local variables
2922 space and global environment variables space are
2923 separated. Local variables are those you define by
2924 simply typing `name=value'. To access a local
2925 variable later on, you have write `$name' or
2926 `${name}'; to execute the contents of a variable
2927 directly type `$name' at the command prompt.
2929 Global environment variables are those you use
2930 setenv/printenv to work with. To run a command stored
2931 in such a variable, you need to use the run command,
2932 and you must not use the '$' sign to access them.
2934 To store commands and special characters in a
2935 variable, please use double quotation marks
2936 surrounding the whole text of the variable, instead
2937 of the backslashes before semicolons and special
2940 - Command Line Editing and History:
2941 CONFIG_CMDLINE_EDITING
2943 Enable editing and History functions for interactive
2944 command line input operations
2946 - Default Environment:
2947 CONFIG_EXTRA_ENV_SETTINGS
2949 Define this to contain any number of null terminated
2950 strings (variable = value pairs) that will be part of
2951 the default environment compiled into the boot image.
2953 For example, place something like this in your
2954 board's config file:
2956 #define CONFIG_EXTRA_ENV_SETTINGS \
2960 Warning: This method is based on knowledge about the
2961 internal format how the environment is stored by the
2962 U-Boot code. This is NOT an official, exported
2963 interface! Although it is unlikely that this format
2964 will change soon, there is no guarantee either.
2965 You better know what you are doing here.
2967 Note: overly (ab)use of the default environment is
2968 discouraged. Make sure to check other ways to preset
2969 the environment like the "source" command or the
2972 CONFIG_ENV_VARS_UBOOT_CONFIG
2974 Define this in order to add variables describing the
2975 U-Boot build configuration to the default environment.
2976 These will be named arch, cpu, board, vendor, and soc.
2978 Enabling this option will cause the following to be defined:
2986 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2988 Define this in order to add variables describing certain
2989 run-time determined information about the hardware to the
2990 environment. These will be named board_name, board_rev.
2992 CONFIG_DELAY_ENVIRONMENT
2994 Normally the environment is loaded when the board is
2995 initialised so that it is available to U-Boot. This inhibits
2996 that so that the environment is not available until
2997 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2998 this is instead controlled by the value of
2999 /config/load-environment.
3001 - Parallel Flash support:
3004 Traditionally U-boot was run on systems with parallel NOR
3005 flash. This option is used to disable support for parallel NOR
3006 flash. This option should be defined if the board does not have
3009 If this option is not defined one of the generic flash drivers
3010 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3011 selected or the board must provide an implementation of the
3012 flash API (see include/flash.h).
3014 - DataFlash Support:
3015 CONFIG_HAS_DATAFLASH
3017 Defining this option enables DataFlash features and
3018 allows to read/write in Dataflash via the standard
3021 - Serial Flash support
3024 Defining this option enables SPI flash commands
3025 'sf probe/read/write/erase/update'.
3027 Usage requires an initial 'probe' to define the serial
3028 flash parameters, followed by read/write/erase/update
3031 The following defaults may be provided by the platform
3032 to handle the common case when only a single serial
3033 flash is present on the system.
3035 CONFIG_SF_DEFAULT_BUS Bus identifier
3036 CONFIG_SF_DEFAULT_CS Chip-select
3037 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3038 CONFIG_SF_DEFAULT_SPEED in Hz
3042 Define this option to include a destructive SPI flash
3045 CONFIG_SF_DUAL_FLASH Dual flash memories
3047 Define this option to use dual flash support where two flash
3048 memories can be connected with a given cs line.
3049 Currently Xilinx Zynq qspi supports these type of connections.
3051 - SystemACE Support:
3054 Adding this option adds support for Xilinx SystemACE
3055 chips attached via some sort of local bus. The address
3056 of the chip must also be defined in the
3057 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3059 #define CONFIG_SYSTEMACE
3060 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3062 When SystemACE support is added, the "ace" device type
3063 becomes available to the fat commands, i.e. fatls.
3065 - TFTP Fixed UDP Port:
3068 If this is defined, the environment variable tftpsrcp
3069 is used to supply the TFTP UDP source port value.
3070 If tftpsrcp isn't defined, the normal pseudo-random port
3071 number generator is used.
3073 Also, the environment variable tftpdstp is used to supply
3074 the TFTP UDP destination port value. If tftpdstp isn't
3075 defined, the normal port 69 is used.
3077 The purpose for tftpsrcp is to allow a TFTP server to
3078 blindly start the TFTP transfer using the pre-configured
3079 target IP address and UDP port. This has the effect of
3080 "punching through" the (Windows XP) firewall, allowing
3081 the remainder of the TFTP transfer to proceed normally.
3082 A better solution is to properly configure the firewall,
3083 but sometimes that is not allowed.
3088 This enables a generic 'hash' command which can produce
3089 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3093 Enable the hash verify command (hash -v). This adds to code
3096 CONFIG_SHA1 - This option enables support of hashing using SHA1
3097 algorithm. The hash is calculated in software.
3098 CONFIG_SHA256 - This option enables support of hashing using
3099 SHA256 algorithm. The hash is calculated in software.
3100 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3101 for SHA1/SHA256 hashing.
3102 This affects the 'hash' command and also the
3103 hash_lookup_algo() function.
3104 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3105 hardware-acceleration for SHA1/SHA256 progressive hashing.
3106 Data can be streamed in a block at a time and the hashing
3107 is performed in hardware.
3109 Note: There is also a sha1sum command, which should perhaps
3110 be deprecated in favour of 'hash sha1'.
3112 - Freescale i.MX specific commands:
3113 CONFIG_CMD_HDMIDETECT
3114 This enables 'hdmidet' command which returns true if an
3115 HDMI monitor is detected. This command is i.MX 6 specific.
3118 This enables the 'bmode' (bootmode) command for forcing
3119 a boot from specific media.
3121 This is useful for forcing the ROM's usb downloader to
3122 activate upon a watchdog reset which is nice when iterating
3123 on U-Boot. Using the reset button or running bmode normal
3124 will set it back to normal. This command currently
3125 supports i.MX53 and i.MX6.
3130 This enables the RSA algorithm used for FIT image verification
3131 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3133 The Modular Exponentiation algorithm in RSA is implemented using
3134 driver model. So CONFIG_DM needs to be enabled by default for this
3135 library to function.
3137 The signing part is build into mkimage regardless of this
3138 option. The software based modular exponentiation is built into
3139 mkimage irrespective of this option.
3141 - bootcount support:
3142 CONFIG_BOOTCOUNT_LIMIT
3144 This enables the bootcounter support, see:
3145 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3148 enable special bootcounter support on at91sam9xe based boards.
3150 enable special bootcounter support on blackfin based boards.
3152 enable special bootcounter support on da850 based boards.
3153 CONFIG_BOOTCOUNT_RAM
3154 enable support for the bootcounter in RAM
3155 CONFIG_BOOTCOUNT_I2C
3156 enable support for the bootcounter on an i2c (like RTC) device.
3157 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3158 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3160 CONFIG_BOOTCOUNT_ALEN = address len
3162 - Show boot progress:
3163 CONFIG_SHOW_BOOT_PROGRESS
3165 Defining this option allows to add some board-
3166 specific code (calling a user-provided function
3167 "show_boot_progress(int)") that enables you to show
3168 the system's boot progress on some display (for
3169 example, some LED's) on your board. At the moment,
3170 the following checkpoints are implemented:
3173 Legacy uImage format:
3176 1 common/cmd_bootm.c before attempting to boot an image
3177 -1 common/cmd_bootm.c Image header has bad magic number
3178 2 common/cmd_bootm.c Image header has correct magic number
3179 -2 common/cmd_bootm.c Image header has bad checksum
3180 3 common/cmd_bootm.c Image header has correct checksum
3181 -3 common/cmd_bootm.c Image data has bad checksum
3182 4 common/cmd_bootm.c Image data has correct checksum
3183 -4 common/cmd_bootm.c Image is for unsupported architecture
3184 5 common/cmd_bootm.c Architecture check OK
3185 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3186 6 common/cmd_bootm.c Image Type check OK
3187 -6 common/cmd_bootm.c gunzip uncompression error
3188 -7 common/cmd_bootm.c Unimplemented compression type
3189 7 common/cmd_bootm.c Uncompression OK
3190 8 common/cmd_bootm.c No uncompress/copy overwrite error
3191 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3193 9 common/image.c Start initial ramdisk verification
3194 -10 common/image.c Ramdisk header has bad magic number
3195 -11 common/image.c Ramdisk header has bad checksum
3196 10 common/image.c Ramdisk header is OK
3197 -12 common/image.c Ramdisk data has bad checksum
3198 11 common/image.c Ramdisk data has correct checksum
3199 12 common/image.c Ramdisk verification complete, start loading
3200 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3201 13 common/image.c Start multifile image verification
3202 14 common/image.c No initial ramdisk, no multifile, continue.
3204 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3206 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3207 -31 post/post.c POST test failed, detected by post_output_backlog()
3208 -32 post/post.c POST test failed, detected by post_run_single()
3210 34 common/cmd_doc.c before loading a Image from a DOC device
3211 -35 common/cmd_doc.c Bad usage of "doc" command
3212 35 common/cmd_doc.c correct usage of "doc" command
3213 -36 common/cmd_doc.c No boot device
3214 36 common/cmd_doc.c correct boot device
3215 -37 common/cmd_doc.c Unknown Chip ID on boot device
3216 37 common/cmd_doc.c correct chip ID found, device available
3217 -38 common/cmd_doc.c Read Error on boot device
3218 38 common/cmd_doc.c reading Image header from DOC device OK
3219 -39 common/cmd_doc.c Image header has bad magic number
3220 39 common/cmd_doc.c Image header has correct magic number
3221 -40 common/cmd_doc.c Error reading Image from DOC device
3222 40 common/cmd_doc.c Image header has correct magic number
3223 41 common/cmd_ide.c before loading a Image from a IDE device
3224 -42 common/cmd_ide.c Bad usage of "ide" command
3225 42 common/cmd_ide.c correct usage of "ide" command
3226 -43 common/cmd_ide.c No boot device
3227 43 common/cmd_ide.c boot device found
3228 -44 common/cmd_ide.c Device not available
3229 44 common/cmd_ide.c Device available
3230 -45 common/cmd_ide.c wrong partition selected
3231 45 common/cmd_ide.c partition selected
3232 -46 common/cmd_ide.c Unknown partition table
3233 46 common/cmd_ide.c valid partition table found
3234 -47 common/cmd_ide.c Invalid partition type
3235 47 common/cmd_ide.c correct partition type
3236 -48 common/cmd_ide.c Error reading Image Header on boot device
3237 48 common/cmd_ide.c reading Image Header from IDE device OK
3238 -49 common/cmd_ide.c Image header has bad magic number
3239 49 common/cmd_ide.c Image header has correct magic number
3240 -50 common/cmd_ide.c Image header has bad checksum
3241 50 common/cmd_ide.c Image header has correct checksum
3242 -51 common/cmd_ide.c Error reading Image from IDE device
3243 51 common/cmd_ide.c reading Image from IDE device OK
3244 52 common/cmd_nand.c before loading a Image from a NAND device
3245 -53 common/cmd_nand.c Bad usage of "nand" command
3246 53 common/cmd_nand.c correct usage of "nand" command
3247 -54 common/cmd_nand.c No boot device
3248 54 common/cmd_nand.c boot device found
3249 -55 common/cmd_nand.c Unknown Chip ID on boot device
3250 55 common/cmd_nand.c correct chip ID found, device available
3251 -56 common/cmd_nand.c Error reading Image Header on boot device
3252 56 common/cmd_nand.c reading Image Header from NAND device OK
3253 -57 common/cmd_nand.c Image header has bad magic number
3254 57 common/cmd_nand.c Image header has correct magic number
3255 -58 common/cmd_nand.c Error reading Image from NAND device
3256 58 common/cmd_nand.c reading Image from NAND device OK
3258 -60 common/env_common.c Environment has a bad CRC, using default
3260 64 net/eth.c starting with Ethernet configuration.
3261 -64 net/eth.c no Ethernet found.
3262 65 net/eth.c Ethernet found.
3264 -80 common/cmd_net.c usage wrong
3265 80 common/cmd_net.c before calling net_loop()
3266 -81 common/cmd_net.c some error in net_loop() occurred
3267 81 common/cmd_net.c net_loop() back without error
3268 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3269 82 common/cmd_net.c trying automatic boot
3270 83 common/cmd_net.c running "source" command
3271 -83 common/cmd_net.c some error in automatic boot or "source" command
3272 84 common/cmd_net.c end without errors
3277 100 common/cmd_bootm.c Kernel FIT Image has correct format
3278 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3279 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3280 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3281 102 common/cmd_bootm.c Kernel unit name specified
3282 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3283 103 common/cmd_bootm.c Found configuration node
3284 104 common/cmd_bootm.c Got kernel subimage node offset
3285 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3286 105 common/cmd_bootm.c Kernel subimage hash verification OK
3287 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3288 106 common/cmd_bootm.c Architecture check OK
3289 -106 common/cmd_bootm.c Kernel subimage has wrong type
3290 107 common/cmd_bootm.c Kernel subimage type OK
3291 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3292 108 common/cmd_bootm.c Got kernel subimage data/size
3293 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3294 -109 common/cmd_bootm.c Can't get kernel subimage type
3295 -110 common/cmd_bootm.c Can't get kernel subimage comp
3296 -111 common/cmd_bootm.c Can't get kernel subimage os
3297 -112 common/cmd_bootm.c Can't get kernel subimage load address
3298 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3300 120 common/image.c Start initial ramdisk verification
3301 -120 common/image.c Ramdisk FIT image has incorrect format
3302 121 common/image.c Ramdisk FIT image has correct format
3303 122 common/image.c No ramdisk subimage unit name, using configuration
3304 -122 common/image.c Can't get configuration for ramdisk subimage
3305 123 common/image.c Ramdisk unit name specified
3306 -124 common/image.c Can't get ramdisk subimage node offset
3307 125 common/image.c Got ramdisk subimage node offset
3308 -125 common/image.c Ramdisk subimage hash verification failed
3309 126 common/image.c Ramdisk subimage hash verification OK
3310 -126 common/image.c Ramdisk subimage for unsupported architecture
3311 127 common/image.c Architecture check OK
3312 -127 common/image.c Can't get ramdisk subimage data/size
3313 128 common/image.c Got ramdisk subimage data/size
3314 129 common/image.c Can't get ramdisk load address
3315 -129 common/image.c Got ramdisk load address
3317 -130 common/cmd_doc.c Incorrect FIT image format
3318 131 common/cmd_doc.c FIT image format OK
3320 -140 common/cmd_ide.c Incorrect FIT image format
3321 141 common/cmd_ide.c FIT image format OK
3323 -150 common/cmd_nand.c Incorrect FIT image format
3324 151 common/cmd_nand.c FIT image format OK
3326 - legacy image format:
3327 CONFIG_IMAGE_FORMAT_LEGACY
3328 enables the legacy image format support in U-Boot.
3331 enabled if CONFIG_FIT_SIGNATURE is not defined.
3333 CONFIG_DISABLE_IMAGE_LEGACY
3334 disable the legacy image format
3336 This define is introduced, as the legacy image format is
3337 enabled per default for backward compatibility.
3339 - FIT image support:
3341 Enable support for the FIT uImage format.
3343 CONFIG_FIT_BEST_MATCH
3344 When no configuration is explicitly selected, default to the
3345 one whose fdt's compatibility field best matches that of
3346 U-Boot itself. A match is considered "best" if it matches the
3347 most specific compatibility entry of U-Boot's fdt's root node.
3348 The order of entries in the configuration's fdt is ignored.
3350 CONFIG_FIT_SIGNATURE
3351 This option enables signature verification of FIT uImages,
3352 using a hash signed and verified using RSA. If
3353 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3354 hashing is available using hardware, RSA library will use it.
3355 See doc/uImage.FIT/signature.txt for more details.
3357 WARNING: When relying on signed FIT images with required
3358 signature check the legacy image format is default
3359 disabled. If a board need legacy image format support
3360 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3362 CONFIG_FIT_DISABLE_SHA256
3363 Supporting SHA256 hashes has quite an impact on binary size.
3364 For constrained systems sha256 hash support can be disabled
3367 - Standalone program support:
3368 CONFIG_STANDALONE_LOAD_ADDR
3370 This option defines a board specific value for the
3371 address where standalone program gets loaded, thus
3372 overwriting the architecture dependent default
3375 - Frame Buffer Address:
3378 Define CONFIG_FB_ADDR if you want to use specific
3379 address for frame buffer. This is typically the case
3380 when using a graphics controller has separate video
3381 memory. U-Boot will then place the frame buffer at
3382 the given address instead of dynamically reserving it
3383 in system RAM by calling lcd_setmem(), which grabs
3384 the memory for the frame buffer depending on the
3385 configured panel size.
3387 Please see board_init_f function.
3389 - Automatic software updates via TFTP server
3391 CONFIG_UPDATE_TFTP_CNT_MAX
3392 CONFIG_UPDATE_TFTP_MSEC_MAX
3394 These options enable and control the auto-update feature;
3395 for a more detailed description refer to doc/README.update.
3397 - MTD Support (mtdparts command, UBI support)
3400 Adds the MTD device infrastructure from the Linux kernel.
3401 Needed for mtdparts command support.
3403 CONFIG_MTD_PARTITIONS
3405 Adds the MTD partitioning infrastructure from the Linux
3406 kernel. Needed for UBI support.
3411 Adds commands for interacting with MTD partitions formatted
3412 with the UBI flash translation layer
3414 Requires also defining CONFIG_RBTREE
3416 CONFIG_UBI_SILENCE_MSG
3418 Make the verbose messages from UBI stop printing. This leaves
3419 warnings and errors enabled.
3422 CONFIG_MTD_UBI_WL_THRESHOLD
3423 This parameter defines the maximum difference between the highest
3424 erase counter value and the lowest erase counter value of eraseblocks
3425 of UBI devices. When this threshold is exceeded, UBI starts performing
3426 wear leveling by means of moving data from eraseblock with low erase
3427 counter to eraseblocks with high erase counter.
3429 The default value should be OK for SLC NAND flashes, NOR flashes and
3430 other flashes which have eraseblock life-cycle 100000 or more.
3431 However, in case of MLC NAND flashes which typically have eraseblock
3432 life-cycle less than 10000, the threshold should be lessened (e.g.,
3433 to 128 or 256, although it does not have to be power of 2).
3437 CONFIG_MTD_UBI_BEB_LIMIT
3438 This option specifies the maximum bad physical eraseblocks UBI
3439 expects on the MTD device (per 1024 eraseblocks). If the
3440 underlying flash does not admit of bad eraseblocks (e.g. NOR
3441 flash), this value is ignored.
3443 NAND datasheets often specify the minimum and maximum NVM
3444 (Number of Valid Blocks) for the flashes' endurance lifetime.
3445 The maximum expected bad eraseblocks per 1024 eraseblocks
3446 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3447 which gives 20 for most NANDs (MaxNVB is basically the total
3448 count of eraseblocks on the chip).
3450 To put it differently, if this value is 20, UBI will try to
3451 reserve about 1.9% of physical eraseblocks for bad blocks
3452 handling. And that will be 1.9% of eraseblocks on the entire
3453 NAND chip, not just the MTD partition UBI attaches. This means
3454 that if you have, say, a NAND flash chip admits maximum 40 bad
3455 eraseblocks, and it is split on two MTD partitions of the same
3456 size, UBI will reserve 40 eraseblocks when attaching a
3461 CONFIG_MTD_UBI_FASTMAP
3462 Fastmap is a mechanism which allows attaching an UBI device
3463 in nearly constant time. Instead of scanning the whole MTD device it
3464 only has to locate a checkpoint (called fastmap) on the device.
3465 The on-flash fastmap contains all information needed to attach
3466 the device. Using fastmap makes only sense on large devices where
3467 attaching by scanning takes long. UBI will not automatically install
3468 a fastmap on old images, but you can set the UBI parameter
3469 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3470 that fastmap-enabled images are still usable with UBI implementations
3471 without fastmap support. On typical flash devices the whole fastmap
3472 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3474 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3475 Set this parameter to enable fastmap automatically on images
3479 CONFIG_MTD_UBI_FM_DEBUG
3480 Enable UBI fastmap debug
3486 Adds commands for interacting with UBI volumes formatted as
3487 UBIFS. UBIFS is read-only in u-boot.
3489 Requires UBI support as well as CONFIG_LZO
3491 CONFIG_UBIFS_SILENCE_MSG
3493 Make the verbose messages from UBIFS stop printing. This leaves
3494 warnings and errors enabled.
3498 Enable building of SPL globally.
3501 LDSCRIPT for linking the SPL binary.
3503 CONFIG_SPL_MAX_FOOTPRINT
3504 Maximum size in memory allocated to the SPL, BSS included.
3505 When defined, the linker checks that the actual memory
3506 used by SPL from _start to __bss_end does not exceed it.
3507 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3508 must not be both defined at the same time.
3511 Maximum size of the SPL image (text, data, rodata, and
3512 linker lists sections), BSS excluded.
3513 When defined, the linker checks that the actual size does
3516 CONFIG_SPL_TEXT_BASE
3517 TEXT_BASE for linking the SPL binary.
3519 CONFIG_SPL_RELOC_TEXT_BASE
3520 Address to relocate to. If unspecified, this is equal to
3521 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3523 CONFIG_SPL_BSS_START_ADDR
3524 Link address for the BSS within the SPL binary.
3526 CONFIG_SPL_BSS_MAX_SIZE
3527 Maximum size in memory allocated to the SPL BSS.
3528 When defined, the linker checks that the actual memory used
3529 by SPL from __bss_start to __bss_end does not exceed it.
3530 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3531 must not be both defined at the same time.
3534 Adress of the start of the stack SPL will use
3536 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3537 When defined, SPL will panic() if the image it has
3538 loaded does not have a signature.
3539 Defining this is useful when code which loads images
3540 in SPL cannot guarantee that absolutely all read errors
3542 An example is the LPC32XX MLC NAND driver, which will
3543 consider that a completely unreadable NAND block is bad,
3544 and thus should be skipped silently.
3546 CONFIG_SPL_RELOC_STACK
3547 Adress of the start of the stack SPL will use after
3548 relocation. If unspecified, this is equal to
3551 CONFIG_SYS_SPL_MALLOC_START
3552 Starting address of the malloc pool used in SPL.
3553 When this option is set the full malloc is used in SPL and
3554 it is set up by spl_init() and before that, the simple malloc()
3555 can be used if CONFIG_SYS_MALLOC_F is defined.
3557 CONFIG_SYS_SPL_MALLOC_SIZE
3558 The size of the malloc pool used in SPL.
3560 CONFIG_SPL_FRAMEWORK
3561 Enable the SPL framework under common/. This framework
3562 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3563 NAND loading of the Linux Kernel.
3566 Enable booting directly to an OS from SPL.
3567 See also: doc/README.falcon
3569 CONFIG_SPL_DISPLAY_PRINT
3570 For ARM, enable an optional function to print more information
3571 about the running system.
3573 CONFIG_SPL_INIT_MINIMAL
3574 Arch init code should be built for a very small image
3576 CONFIG_SPL_LIBCOMMON_SUPPORT
3577 Support for common/libcommon.o in SPL binary
3579 CONFIG_SPL_LIBDISK_SUPPORT
3580 Support for disk/libdisk.o in SPL binary
3582 CONFIG_SPL_I2C_SUPPORT
3583 Support for drivers/i2c/libi2c.o in SPL binary
3585 CONFIG_SPL_GPIO_SUPPORT
3586 Support for drivers/gpio/libgpio.o in SPL binary
3588 CONFIG_SPL_MMC_SUPPORT
3589 Support for drivers/mmc/libmmc.o in SPL binary
3591 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3592 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3593 Address and partition on the MMC to load U-Boot from
3594 when the MMC is being used in raw mode.
3596 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3597 Partition on the MMC to load U-Boot from when the MMC is being
3600 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3601 Sector to load kernel uImage from when MMC is being
3602 used in raw mode (for Falcon mode)
3604 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3605 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3606 Sector and number of sectors to load kernel argument
3607 parameters from when MMC is being used in raw mode
3610 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3611 Partition on the MMC to load U-Boot from when the MMC is being
3614 CONFIG_SPL_FAT_SUPPORT
3615 Support for fs/fat/libfat.o in SPL binary
3617 CONFIG_SPL_EXT_SUPPORT
3618 Support for EXT filesystem in SPL binary
3620 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3621 Filename to read to load U-Boot when reading from filesystem
3623 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3624 Filename to read to load kernel uImage when reading
3625 from filesystem (for Falcon mode)
3627 CONFIG_SPL_FS_LOAD_ARGS_NAME
3628 Filename to read to load kernel argument parameters
3629 when reading from filesystem (for Falcon mode)
3631 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3632 Set this for NAND SPL on PPC mpc83xx targets, so that
3633 start.S waits for the rest of the SPL to load before
3634 continuing (the hardware starts execution after just
3635 loading the first page rather than the full 4K).
3637 CONFIG_SPL_SKIP_RELOCATE
3638 Avoid SPL relocation
3640 CONFIG_SPL_NAND_BASE
3641 Include nand_base.c in the SPL. Requires
3642 CONFIG_SPL_NAND_DRIVERS.
3644 CONFIG_SPL_NAND_DRIVERS
3645 SPL uses normal NAND drivers, not minimal drivers.
3648 Include standard software ECC in the SPL
3650 CONFIG_SPL_NAND_SIMPLE
3651 Support for NAND boot using simple NAND drivers that
3652 expose the cmd_ctrl() interface.
3654 CONFIG_SPL_MTD_SUPPORT
3655 Support for the MTD subsystem within SPL. Useful for
3656 environment on NAND support within SPL.
3658 CONFIG_SPL_NAND_RAW_ONLY
3659 Support to boot only raw u-boot.bin images. Use this only
3660 if you need to save space.
3662 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3663 Set for the SPL on PPC mpc8xxx targets, support for
3664 drivers/ddr/fsl/libddr.o in SPL binary.
3666 CONFIG_SPL_COMMON_INIT_DDR
3667 Set for common ddr init with serial presence detect in
3670 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3671 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3672 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3673 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3674 CONFIG_SYS_NAND_ECCBYTES
3675 Defines the size and behavior of the NAND that SPL uses
3678 CONFIG_SPL_NAND_BOOT
3679 Add support NAND boot
3681 CONFIG_SYS_NAND_U_BOOT_OFFS
3682 Location in NAND to read U-Boot from
3684 CONFIG_SYS_NAND_U_BOOT_DST
3685 Location in memory to load U-Boot to
3687 CONFIG_SYS_NAND_U_BOOT_SIZE
3688 Size of image to load
3690 CONFIG_SYS_NAND_U_BOOT_START
3691 Entry point in loaded image to jump to
3693 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3694 Define this if you need to first read the OOB and then the
3695 data. This is used, for example, on davinci platforms.
3697 CONFIG_SPL_OMAP3_ID_NAND
3698 Support for an OMAP3-specific set of functions to return the
3699 ID and MFR of the first attached NAND chip, if present.
3701 CONFIG_SPL_SERIAL_SUPPORT
3702 Support for drivers/serial/libserial.o in SPL binary
3704 CONFIG_SPL_SPI_FLASH_SUPPORT
3705 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3707 CONFIG_SPL_SPI_SUPPORT
3708 Support for drivers/spi/libspi.o in SPL binary
3710 CONFIG_SPL_RAM_DEVICE
3711 Support for running image already present in ram, in SPL binary
3713 CONFIG_SPL_LIBGENERIC_SUPPORT
3714 Support for lib/libgeneric.o in SPL binary
3716 CONFIG_SPL_ENV_SUPPORT
3717 Support for the environment operating in SPL binary
3719 CONFIG_SPL_NET_SUPPORT
3720 Support for the net/libnet.o in SPL binary.
3721 It conflicts with SPL env from storage medium specified by
3722 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3725 Image offset to which the SPL should be padded before appending
3726 the SPL payload. By default, this is defined as
3727 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3728 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3729 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3732 Final target image containing SPL and payload. Some SPLs
3733 use an arch-specific makefile fragment instead, for
3734 example if more than one image needs to be produced.
3736 CONFIG_FIT_SPL_PRINT
3737 Printing information about a FIT image adds quite a bit of
3738 code to SPL. So this is normally disabled in SPL. Use this
3739 option to re-enable it. This will affect the output of the
3740 bootm command when booting a FIT image.
3744 Enable building of TPL globally.
3747 Image offset to which the TPL should be padded before appending
3748 the TPL payload. By default, this is defined as
3749 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3750 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3751 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3756 [so far only for SMDK2400 boards]
3758 - Modem support enable:
3759 CONFIG_MODEM_SUPPORT
3761 - RTS/CTS Flow control enable:
3764 - Modem debug support:
3765 CONFIG_MODEM_SUPPORT_DEBUG
3767 Enables debugging stuff (char screen[1024], dbg())
3768 for modem support. Useful only with BDI2000.
3770 - Interrupt support (PPC):
3772 There are common interrupt_init() and timer_interrupt()
3773 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3774 for CPU specific initialization. interrupt_init_cpu()
3775 should set decrementer_count to appropriate value. If
3776 CPU resets decrementer automatically after interrupt
3777 (ppc4xx) it should set decrementer_count to zero.
3778 timer_interrupt() calls timer_interrupt_cpu() for CPU
3779 specific handling. If board has watchdog / status_led
3780 / other_activity_monitor it works automatically from
3781 general timer_interrupt().
3785 In the target system modem support is enabled when a
3786 specific key (key combination) is pressed during
3787 power-on. Otherwise U-Boot will boot normally
3788 (autoboot). The key_pressed() function is called from
3789 board_init(). Currently key_pressed() is a dummy
3790 function, returning 1 and thus enabling modem
3793 If there are no modem init strings in the
3794 environment, U-Boot proceed to autoboot; the
3795 previous output (banner, info printfs) will be
3798 See also: doc/README.Modem
3800 Board initialization settings:
3801 ------------------------------
3803 During Initialization u-boot calls a number of board specific functions
3804 to allow the preparation of board specific prerequisites, e.g. pin setup
3805 before drivers are initialized. To enable these callbacks the
3806 following configuration macros have to be defined. Currently this is
3807 architecture specific, so please check arch/your_architecture/lib/board.c
3808 typically in board_init_f() and board_init_r().
3810 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3811 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3812 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3813 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3815 Configuration Settings:
3816 -----------------------
3818 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3819 Optionally it can be defined to support 64-bit memory commands.
3821 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3822 undefine this when you're short of memory.
3824 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3825 width of the commands listed in the 'help' command output.
3827 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3828 prompt for user input.
3830 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3832 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3834 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3836 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3837 the application (usually a Linux kernel) when it is
3840 - CONFIG_SYS_BAUDRATE_TABLE:
3841 List of legal baudrate settings for this board.
3843 - CONFIG_SYS_CONSOLE_INFO_QUIET
3844 Suppress display of console information at boot.
3846 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3847 If the board specific function
3848 extern int overwrite_console (void);
3849 returns 1, the stdin, stderr and stdout are switched to the
3850 serial port, else the settings in the environment are used.
3852 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3853 Enable the call to overwrite_console().
3855 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3856 Enable overwrite of previous console environment settings.
3858 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3859 Begin and End addresses of the area used by the
3862 - CONFIG_SYS_ALT_MEMTEST:
3863 Enable an alternate, more extensive memory test.
3865 - CONFIG_SYS_MEMTEST_SCRATCH:
3866 Scratch address used by the alternate memory test
3867 You only need to set this if address zero isn't writeable
3869 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3870 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3871 this specified memory area will get subtracted from the top
3872 (end) of RAM and won't get "touched" at all by U-Boot. By
3873 fixing up gd->ram_size the Linux kernel should gets passed
3874 the now "corrected" memory size and won't touch it either.
3875 This should work for arch/ppc and arch/powerpc. Only Linux
3876 board ports in arch/powerpc with bootwrapper support that
3877 recalculate the memory size from the SDRAM controller setup
3878 will have to get fixed in Linux additionally.
3880 This option can be used as a workaround for the 440EPx/GRx
3881 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3884 WARNING: Please make sure that this value is a multiple of
3885 the Linux page size (normally 4k). If this is not the case,
3886 then the end address of the Linux memory will be located at a
3887 non page size aligned address and this could cause major
3890 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3891 Enable temporary baudrate change while serial download
3893 - CONFIG_SYS_SDRAM_BASE:
3894 Physical start address of SDRAM. _Must_ be 0 here.
3896 - CONFIG_SYS_MBIO_BASE:
3897 Physical start address of Motherboard I/O (if using a
3900 - CONFIG_SYS_FLASH_BASE:
3901 Physical start address of Flash memory.
3903 - CONFIG_SYS_MONITOR_BASE:
3904 Physical start address of boot monitor code (set by
3905 make config files to be same as the text base address
3906 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3907 CONFIG_SYS_FLASH_BASE when booting from flash.
3909 - CONFIG_SYS_MONITOR_LEN:
3910 Size of memory reserved for monitor code, used to
3911 determine _at_compile_time_ (!) if the environment is
3912 embedded within the U-Boot image, or in a separate
3915 - CONFIG_SYS_MALLOC_LEN:
3916 Size of DRAM reserved for malloc() use.
3918 - CONFIG_SYS_MALLOC_F_LEN
3919 Size of the malloc() pool for use before relocation. If
3920 this is defined, then a very simple malloc() implementation
3921 will become available before relocation. The address is just
3922 below the global data, and the stack is moved down to make
3925 This feature allocates regions with increasing addresses
3926 within the region. calloc() is supported, but realloc()
3927 is not available. free() is supported but does nothing.
3928 The memory will be freed (or in fact just forgotten) when
3929 U-Boot relocates itself.
3931 Pre-relocation malloc() is only supported on ARM and sandbox
3932 at present but is fairly easy to enable for other archs.
3934 - CONFIG_SYS_MALLOC_SIMPLE
3935 Provides a simple and small malloc() and calloc() for those
3936 boards which do not use the full malloc in SPL (which is
3937 enabled with CONFIG_SYS_SPL_MALLOC_START).
3939 - CONFIG_SYS_NONCACHED_MEMORY:
3940 Size of non-cached memory area. This area of memory will be
3941 typically located right below the malloc() area and mapped
3942 uncached in the MMU. This is useful for drivers that would
3943 otherwise require a lot of explicit cache maintenance. For
3944 some drivers it's also impossible to properly maintain the
3945 cache. For example if the regions that need to be flushed
3946 are not a multiple of the cache-line size, *and* padding
3947 cannot be allocated between the regions to align them (i.e.
3948 if the HW requires a contiguous array of regions, and the
3949 size of each region is not cache-aligned), then a flush of
3950 one region may result in overwriting data that hardware has
3951 written to another region in the same cache-line. This can
3952 happen for example in network drivers where descriptors for
3953 buffers are typically smaller than the CPU cache-line (e.g.
3954 16 bytes vs. 32 or 64 bytes).
3956 Non-cached memory is only supported on 32-bit ARM at present.
3958 - CONFIG_SYS_BOOTM_LEN:
3959 Normally compressed uImages are limited to an
3960 uncompressed size of 8 MBytes. If this is not enough,
3961 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3962 to adjust this setting to your needs.
3964 - CONFIG_SYS_BOOTMAPSZ:
3965 Maximum size of memory mapped by the startup code of
3966 the Linux kernel; all data that must be processed by
3967 the Linux kernel (bd_info, boot arguments, FDT blob if
3968 used) must be put below this limit, unless "bootm_low"
3969 environment variable is defined and non-zero. In such case
3970 all data for the Linux kernel must be between "bootm_low"
3971 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3972 variable "bootm_mapsize" will override the value of
3973 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3974 then the value in "bootm_size" will be used instead.
3976 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3977 Enable initrd_high functionality. If defined then the
3978 initrd_high feature is enabled and the bootm ramdisk subcommand
3981 - CONFIG_SYS_BOOT_GET_CMDLINE:
3982 Enables allocating and saving kernel cmdline in space between
3983 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3985 - CONFIG_SYS_BOOT_GET_KBD:
3986 Enables allocating and saving a kernel copy of the bd_info in
3987 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3989 - CONFIG_SYS_MAX_FLASH_BANKS:
3990 Max number of Flash memory banks
3992 - CONFIG_SYS_MAX_FLASH_SECT:
3993 Max number of sectors on a Flash chip
3995 - CONFIG_SYS_FLASH_ERASE_TOUT:
3996 Timeout for Flash erase operations (in ms)
3998 - CONFIG_SYS_FLASH_WRITE_TOUT:
3999 Timeout for Flash write operations (in ms)
4001 - CONFIG_SYS_FLASH_LOCK_TOUT
4002 Timeout for Flash set sector lock bit operation (in ms)
4004 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4005 Timeout for Flash clear lock bits operation (in ms)
4007 - CONFIG_SYS_FLASH_PROTECTION
4008 If defined, hardware flash sectors protection is used
4009 instead of U-Boot software protection.
4011 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4013 Enable TFTP transfers directly to flash memory;
4014 without this option such a download has to be
4015 performed in two steps: (1) download to RAM, and (2)
4016 copy from RAM to flash.
4018 The two-step approach is usually more reliable, since
4019 you can check if the download worked before you erase
4020 the flash, but in some situations (when system RAM is
4021 too limited to allow for a temporary copy of the
4022 downloaded image) this option may be very useful.
4024 - CONFIG_SYS_FLASH_CFI:
4025 Define if the flash driver uses extra elements in the
4026 common flash structure for storing flash geometry.
4028 - CONFIG_FLASH_CFI_DRIVER
4029 This option also enables the building of the cfi_flash driver
4030 in the drivers directory
4032 - CONFIG_FLASH_CFI_MTD
4033 This option enables the building of the cfi_mtd driver
4034 in the drivers directory. The driver exports CFI flash
4037 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4038 Use buffered writes to flash.
4040 - CONFIG_FLASH_SPANSION_S29WS_N
4041 s29ws-n MirrorBit flash has non-standard addresses for buffered
4044 - CONFIG_SYS_FLASH_QUIET_TEST
4045 If this option is defined, the common CFI flash doesn't
4046 print it's warning upon not recognized FLASH banks. This
4047 is useful, if some of the configured banks are only
4048 optionally available.
4050 - CONFIG_FLASH_SHOW_PROGRESS
4051 If defined (must be an integer), print out countdown
4052 digits and dots. Recommended value: 45 (9..1) for 80
4053 column displays, 15 (3..1) for 40 column displays.
4055 - CONFIG_FLASH_VERIFY
4056 If defined, the content of the flash (destination) is compared
4057 against the source after the write operation. An error message
4058 will be printed when the contents are not identical.
4059 Please note that this option is useless in nearly all cases,
4060 since such flash programming errors usually are detected earlier
4061 while unprotecting/erasing/programming. Please only enable
4062 this option if you really know what you are doing.
4064 - CONFIG_SYS_RX_ETH_BUFFER:
4065 Defines the number of Ethernet receive buffers. On some
4066 Ethernet controllers it is recommended to set this value
4067 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4068 buffers can be full shortly after enabling the interface
4069 on high Ethernet traffic.
4070 Defaults to 4 if not defined.
4072 - CONFIG_ENV_MAX_ENTRIES
4074 Maximum number of entries in the hash table that is used
4075 internally to store the environment settings. The default
4076 setting is supposed to be generous and should work in most
4077 cases. This setting can be used to tune behaviour; see
4078 lib/hashtable.c for details.
4080 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4081 - CONFIG_ENV_FLAGS_LIST_STATIC
4082 Enable validation of the values given to environment variables when
4083 calling env set. Variables can be restricted to only decimal,
4084 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4085 the variables can also be restricted to IP address or MAC address.
4087 The format of the list is:
4088 type_attribute = [s|d|x|b|i|m]
4089 access_attribute = [a|r|o|c]
4090 attributes = type_attribute[access_attribute]
4091 entry = variable_name[:attributes]
4094 The type attributes are:
4095 s - String (default)
4098 b - Boolean ([1yYtT|0nNfF])
4102 The access attributes are:
4108 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4109 Define this to a list (string) to define the ".flags"
4110 environment variable in the default or embedded environment.
4112 - CONFIG_ENV_FLAGS_LIST_STATIC
4113 Define this to a list (string) to define validation that
4114 should be done if an entry is not found in the ".flags"
4115 environment variable. To override a setting in the static
4116 list, simply add an entry for the same variable name to the
4119 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4120 regular expression. This allows multiple variables to define the same
4121 flags without explicitly listing them for each variable.
4123 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4124 If defined, don't allow the -f switch to env set override variable
4127 - CONFIG_SYS_GENERIC_BOARD
4128 This selects the architecture-generic board system instead of the
4129 architecture-specific board files. It is intended to move boards
4130 to this new framework over time. Defining this will disable the
4131 arch/foo/lib/board.c file and use common/board_f.c and
4132 common/board_r.c instead. To use this option your architecture
4133 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4134 If you find problems enabling this option on your board please report
4135 the problem and send patches!
4137 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4138 This is set by OMAP boards for the max time that reset should
4139 be asserted. See doc/README.omap-reset-time for details on how
4140 the value can be calculated on a given board.
4143 If stdint.h is available with your toolchain you can define this
4144 option to enable it. You can provide option 'USE_STDINT=1' when
4145 building U-Boot to enable this.
4147 The following definitions that deal with the placement and management
4148 of environment data (variable area); in general, we support the
4149 following configurations:
4151 - CONFIG_BUILD_ENVCRC:
4153 Builds up envcrc with the target environment so that external utils
4154 may easily extract it and embed it in final U-Boot images.
4156 - CONFIG_ENV_IS_IN_FLASH:
4158 Define this if the environment is in flash memory.
4160 a) The environment occupies one whole flash sector, which is
4161 "embedded" in the text segment with the U-Boot code. This
4162 happens usually with "bottom boot sector" or "top boot
4163 sector" type flash chips, which have several smaller
4164 sectors at the start or the end. For instance, such a
4165 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4166 such a case you would place the environment in one of the
4167 4 kB sectors - with U-Boot code before and after it. With
4168 "top boot sector" type flash chips, you would put the
4169 environment in one of the last sectors, leaving a gap
4170 between U-Boot and the environment.
4172 - CONFIG_ENV_OFFSET:
4174 Offset of environment data (variable area) to the
4175 beginning of flash memory; for instance, with bottom boot
4176 type flash chips the second sector can be used: the offset
4177 for this sector is given here.
4179 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4183 This is just another way to specify the start address of
4184 the flash sector containing the environment (instead of
4187 - CONFIG_ENV_SECT_SIZE:
4189 Size of the sector containing the environment.
4192 b) Sometimes flash chips have few, equal sized, BIG sectors.
4193 In such a case you don't want to spend a whole sector for
4198 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4199 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4200 of this flash sector for the environment. This saves
4201 memory for the RAM copy of the environment.
4203 It may also save flash memory if you decide to use this
4204 when your environment is "embedded" within U-Boot code,
4205 since then the remainder of the flash sector could be used
4206 for U-Boot code. It should be pointed out that this is
4207 STRONGLY DISCOURAGED from a robustness point of view:
4208 updating the environment in flash makes it always
4209 necessary to erase the WHOLE sector. If something goes
4210 wrong before the contents has been restored from a copy in
4211 RAM, your target system will be dead.
4213 - CONFIG_ENV_ADDR_REDUND
4214 CONFIG_ENV_SIZE_REDUND
4216 These settings describe a second storage area used to hold
4217 a redundant copy of the environment data, so that there is
4218 a valid backup copy in case there is a power failure during
4219 a "saveenv" operation.
4221 BE CAREFUL! Any changes to the flash layout, and some changes to the
4222 source code will make it necessary to adapt <board>/u-boot.lds*
4226 - CONFIG_ENV_IS_IN_NVRAM:
4228 Define this if you have some non-volatile memory device
4229 (NVRAM, battery buffered SRAM) which you want to use for the
4235 These two #defines are used to determine the memory area you
4236 want to use for environment. It is assumed that this memory
4237 can just be read and written to, without any special
4240 BE CAREFUL! The first access to the environment happens quite early
4241 in U-Boot initialization (when we try to get the setting of for the
4242 console baudrate). You *MUST* have mapped your NVRAM area then, or
4245 Please note that even with NVRAM we still use a copy of the
4246 environment in RAM: we could work on NVRAM directly, but we want to
4247 keep settings there always unmodified except somebody uses "saveenv"
4248 to save the current settings.
4251 - CONFIG_ENV_IS_IN_EEPROM:
4253 Use this if you have an EEPROM or similar serial access
4254 device and a driver for it.
4256 - CONFIG_ENV_OFFSET:
4259 These two #defines specify the offset and size of the
4260 environment area within the total memory of your EEPROM.
4262 - CONFIG_SYS_I2C_EEPROM_ADDR:
4263 If defined, specified the chip address of the EEPROM device.
4264 The default address is zero.
4266 - CONFIG_SYS_I2C_EEPROM_BUS:
4267 If defined, specified the i2c bus of the EEPROM device.
4269 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4270 If defined, the number of bits used to address bytes in a
4271 single page in the EEPROM device. A 64 byte page, for example
4272 would require six bits.
4274 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4275 If defined, the number of milliseconds to delay between
4276 page writes. The default is zero milliseconds.
4278 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4279 The length in bytes of the EEPROM memory array address. Note
4280 that this is NOT the chip address length!
4282 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4283 EEPROM chips that implement "address overflow" are ones
4284 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4285 address and the extra bits end up in the "chip address" bit
4286 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4289 Note that we consider the length of the address field to
4290 still be one byte because the extra address bits are hidden
4291 in the chip address.
4293 - CONFIG_SYS_EEPROM_SIZE:
4294 The size in bytes of the EEPROM device.
4296 - CONFIG_ENV_EEPROM_IS_ON_I2C
4297 define this, if you have I2C and SPI activated, and your
4298 EEPROM, which holds the environment, is on the I2C bus.
4300 - CONFIG_I2C_ENV_EEPROM_BUS
4301 if you have an Environment on an EEPROM reached over
4302 I2C muxes, you can define here, how to reach this
4303 EEPROM. For example:
4305 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4307 EEPROM which holds the environment, is reached over
4308 a pca9547 i2c mux with address 0x70, channel 3.
4310 - CONFIG_ENV_IS_IN_DATAFLASH:
4312 Define this if you have a DataFlash memory device which you
4313 want to use for the environment.
4315 - CONFIG_ENV_OFFSET:
4319 These three #defines specify the offset and size of the
4320 environment area within the total memory of your DataFlash placed
4321 at the specified address.
4323 - CONFIG_ENV_IS_IN_SPI_FLASH:
4325 Define this if you have a SPI Flash memory device which you
4326 want to use for the environment.
4328 - CONFIG_ENV_OFFSET:
4331 These two #defines specify the offset and size of the
4332 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4333 aligned to an erase sector boundary.
4335 - CONFIG_ENV_SECT_SIZE:
4337 Define the SPI flash's sector size.
4339 - CONFIG_ENV_OFFSET_REDUND (optional):
4341 This setting describes a second storage area of CONFIG_ENV_SIZE
4342 size used to hold a redundant copy of the environment data, so
4343 that there is a valid backup copy in case there is a power failure
4344 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4345 aligned to an erase sector boundary.
4347 - CONFIG_ENV_SPI_BUS (optional):
4348 - CONFIG_ENV_SPI_CS (optional):
4350 Define the SPI bus and chip select. If not defined they will be 0.
4352 - CONFIG_ENV_SPI_MAX_HZ (optional):
4354 Define the SPI max work clock. If not defined then use 1MHz.
4356 - CONFIG_ENV_SPI_MODE (optional):
4358 Define the SPI work mode. If not defined then use SPI_MODE_3.
4360 - CONFIG_ENV_IS_IN_REMOTE:
4362 Define this if you have a remote memory space which you
4363 want to use for the local device's environment.
4368 These two #defines specify the address and size of the
4369 environment area within the remote memory space. The
4370 local device can get the environment from remote memory
4371 space by SRIO or PCIE links.
4373 BE CAREFUL! For some special cases, the local device can not use
4374 "saveenv" command. For example, the local device will get the
4375 environment stored in a remote NOR flash by SRIO or PCIE link,
4376 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4378 - CONFIG_ENV_IS_IN_NAND:
4380 Define this if you have a NAND device which you want to use
4381 for the environment.
4383 - CONFIG_ENV_OFFSET:
4386 These two #defines specify the offset and size of the environment
4387 area within the first NAND device. CONFIG_ENV_OFFSET must be
4388 aligned to an erase block boundary.
4390 - CONFIG_ENV_OFFSET_REDUND (optional):
4392 This setting describes a second storage area of CONFIG_ENV_SIZE
4393 size used to hold a redundant copy of the environment data, so
4394 that there is a valid backup copy in case there is a power failure
4395 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4396 aligned to an erase block boundary.
4398 - CONFIG_ENV_RANGE (optional):
4400 Specifies the length of the region in which the environment
4401 can be written. This should be a multiple of the NAND device's
4402 block size. Specifying a range with more erase blocks than
4403 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4404 the range to be avoided.
4406 - CONFIG_ENV_OFFSET_OOB (optional):
4408 Enables support for dynamically retrieving the offset of the
4409 environment from block zero's out-of-band data. The
4410 "nand env.oob" command can be used to record this offset.
4411 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4412 using CONFIG_ENV_OFFSET_OOB.
4414 - CONFIG_NAND_ENV_DST
4416 Defines address in RAM to which the nand_spl code should copy the
4417 environment. If redundant environment is used, it will be copied to
4418 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4420 - CONFIG_ENV_IS_IN_UBI:
4422 Define this if you have an UBI volume that you want to use for the
4423 environment. This has the benefit of wear-leveling the environment
4424 accesses, which is important on NAND.
4426 - CONFIG_ENV_UBI_PART:
4428 Define this to a string that is the mtd partition containing the UBI.
4430 - CONFIG_ENV_UBI_VOLUME:
4432 Define this to the name of the volume that you want to store the
4435 - CONFIG_ENV_UBI_VOLUME_REDUND:
4437 Define this to the name of another volume to store a second copy of
4438 the environment in. This will enable redundant environments in UBI.
4439 It is assumed that both volumes are in the same MTD partition.
4441 - CONFIG_UBI_SILENCE_MSG
4442 - CONFIG_UBIFS_SILENCE_MSG
4444 You will probably want to define these to avoid a really noisy system
4445 when storing the env in UBI.
4447 - CONFIG_ENV_IS_IN_FAT:
4448 Define this if you want to use the FAT file system for the environment.
4450 - FAT_ENV_INTERFACE:
4452 Define this to a string that is the name of the block device.
4454 - FAT_ENV_DEV_AND_PART:
4456 Define this to a string to specify the partition of the device. It can
4459 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4460 - "D:P": device D partition P. Error occurs if device D has no
4463 - "D" or "D:": device D partition 1 if device D has partition
4464 table, or the whole device D if has no partition
4466 - "D:auto": first partition in device D with bootable flag set.
4467 If none, first valid partition in device D. If no
4468 partition table then means device D.
4472 It's a string of the FAT file name. This file use to store the
4476 This should be defined. Otherwise it cannot save the environment file.
4478 - CONFIG_ENV_IS_IN_MMC:
4480 Define this if you have an MMC device which you want to use for the
4483 - CONFIG_SYS_MMC_ENV_DEV:
4485 Specifies which MMC device the environment is stored in.
4487 - CONFIG_SYS_MMC_ENV_PART (optional):
4489 Specifies which MMC partition the environment is stored in. If not
4490 set, defaults to partition 0, the user area. Common values might be
4491 1 (first MMC boot partition), 2 (second MMC boot partition).
4493 - CONFIG_ENV_OFFSET:
4496 These two #defines specify the offset and size of the environment
4497 area within the specified MMC device.
4499 If offset is positive (the usual case), it is treated as relative to
4500 the start of the MMC partition. If offset is negative, it is treated
4501 as relative to the end of the MMC partition. This can be useful if
4502 your board may be fitted with different MMC devices, which have
4503 different sizes for the MMC partitions, and you always want the
4504 environment placed at the very end of the partition, to leave the
4505 maximum possible space before it, to store other data.
4507 These two values are in units of bytes, but must be aligned to an
4508 MMC sector boundary.
4510 - CONFIG_ENV_OFFSET_REDUND (optional):
4512 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4513 hold a redundant copy of the environment data. This provides a
4514 valid backup copy in case the other copy is corrupted, e.g. due
4515 to a power failure during a "saveenv" operation.
4517 This value may also be positive or negative; this is handled in the
4518 same way as CONFIG_ENV_OFFSET.
4520 This value is also in units of bytes, but must also be aligned to
4521 an MMC sector boundary.
4523 - CONFIG_ENV_SIZE_REDUND (optional):
4525 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4526 set. If this value is set, it must be set to the same value as
4529 - CONFIG_SYS_SPI_INIT_OFFSET
4531 Defines offset to the initial SPI buffer area in DPRAM. The
4532 area is used at an early stage (ROM part) if the environment
4533 is configured to reside in the SPI EEPROM: We need a 520 byte
4534 scratch DPRAM area. It is used between the two initialization
4535 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4536 to be a good choice since it makes it far enough from the
4537 start of the data area as well as from the stack pointer.
4539 Please note that the environment is read-only until the monitor
4540 has been relocated to RAM and a RAM copy of the environment has been
4541 created; also, when using EEPROM you will have to use getenv_f()
4542 until then to read environment variables.
4544 The environment is protected by a CRC32 checksum. Before the monitor
4545 is relocated into RAM, as a result of a bad CRC you will be working
4546 with the compiled-in default environment - *silently*!!! [This is
4547 necessary, because the first environment variable we need is the
4548 "baudrate" setting for the console - if we have a bad CRC, we don't
4549 have any device yet where we could complain.]
4551 Note: once the monitor has been relocated, then it will complain if
4552 the default environment is used; a new CRC is computed as soon as you
4553 use the "saveenv" command to store a valid environment.
4555 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4556 Echo the inverted Ethernet link state to the fault LED.
4558 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4559 also needs to be defined.
4561 - CONFIG_SYS_FAULT_MII_ADDR:
4562 MII address of the PHY to check for the Ethernet link state.
4564 - CONFIG_NS16550_MIN_FUNCTIONS:
4565 Define this if you desire to only have use of the NS16550_init
4566 and NS16550_putc functions for the serial driver located at
4567 drivers/serial/ns16550.c. This option is useful for saving
4568 space for already greatly restricted images, including but not
4569 limited to NAND_SPL configurations.
4571 - CONFIG_DISPLAY_BOARDINFO
4572 Display information about the board that U-Boot is running on
4573 when U-Boot starts up. The board function checkboard() is called
4576 - CONFIG_DISPLAY_BOARDINFO_LATE
4577 Similar to the previous option, but display this information
4578 later, once stdio is running and output goes to the LCD, if
4581 - CONFIG_BOARD_SIZE_LIMIT:
4582 Maximum size of the U-Boot image. When defined, the
4583 build system checks that the actual size does not
4586 Low Level (hardware related) configuration options:
4587 ---------------------------------------------------
4589 - CONFIG_SYS_CACHELINE_SIZE:
4590 Cache Line Size of the CPU.
4592 - CONFIG_SYS_DEFAULT_IMMR:
4593 Default address of the IMMR after system reset.
4595 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4596 and RPXsuper) to be able to adjust the position of
4597 the IMMR register after a reset.
4599 - CONFIG_SYS_CCSRBAR_DEFAULT:
4600 Default (power-on reset) physical address of CCSR on Freescale
4603 - CONFIG_SYS_CCSRBAR:
4604 Virtual address of CCSR. On a 32-bit build, this is typically
4605 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4607 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4608 for cross-platform code that uses that macro instead.
4610 - CONFIG_SYS_CCSRBAR_PHYS:
4611 Physical address of CCSR. CCSR can be relocated to a new
4612 physical address, if desired. In this case, this macro should
4613 be set to that address. Otherwise, it should be set to the
4614 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4615 is typically relocated on 36-bit builds. It is recommended
4616 that this macro be defined via the _HIGH and _LOW macros:
4618 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4619 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4621 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4622 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4623 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4624 used in assembly code, so it must not contain typecasts or
4625 integer size suffixes (e.g. "ULL").
4627 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4628 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4629 used in assembly code, so it must not contain typecasts or
4630 integer size suffixes (e.g. "ULL").
4632 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4633 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4634 forced to a value that ensures that CCSR is not relocated.
4636 - Floppy Disk Support:
4637 CONFIG_SYS_FDC_DRIVE_NUMBER
4639 the default drive number (default value 0)
4641 CONFIG_SYS_ISA_IO_STRIDE
4643 defines the spacing between FDC chipset registers
4646 CONFIG_SYS_ISA_IO_OFFSET
4648 defines the offset of register from address. It
4649 depends on which part of the data bus is connected to
4650 the FDC chipset. (default value 0)
4652 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4653 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4656 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4657 fdc_hw_init() is called at the beginning of the FDC
4658 setup. fdc_hw_init() must be provided by the board
4659 source code. It is used to make hardware-dependent
4663 Most IDE controllers were designed to be connected with PCI
4664 interface. Only few of them were designed for AHB interface.
4665 When software is doing ATA command and data transfer to
4666 IDE devices through IDE-AHB controller, some additional
4667 registers accessing to these kind of IDE-AHB controller
4670 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4671 DO NOT CHANGE unless you know exactly what you're
4672 doing! (11-4) [MPC8xx/82xx systems only]
4674 - CONFIG_SYS_INIT_RAM_ADDR:
4676 Start address of memory area that can be used for
4677 initial data and stack; please note that this must be
4678 writable memory that is working WITHOUT special
4679 initialization, i. e. you CANNOT use normal RAM which
4680 will become available only after programming the
4681 memory controller and running certain initialization
4684 U-Boot uses the following memory types:
4685 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4686 - MPC824X: data cache
4687 - PPC4xx: data cache
4689 - CONFIG_SYS_GBL_DATA_OFFSET:
4691 Offset of the initial data structure in the memory
4692 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4693 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4694 data is located at the end of the available space
4695 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4696 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4697 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4698 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4701 On the MPC824X (or other systems that use the data
4702 cache for initial memory) the address chosen for
4703 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4704 point to an otherwise UNUSED address space between
4705 the top of RAM and the start of the PCI space.
4707 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4709 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4711 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4713 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4715 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4717 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4719 - CONFIG_SYS_OR_TIMING_SDRAM:
4722 - CONFIG_SYS_MAMR_PTA:
4723 periodic timer for refresh
4725 - CONFIG_SYS_DER: Debug Event Register (37-47)
4727 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4728 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4729 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4730 CONFIG_SYS_BR1_PRELIM:
4731 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4733 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4734 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4735 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4736 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4738 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4739 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4740 Machine Mode Register and Memory Periodic Timer
4741 Prescaler definitions (SDRAM timing)
4743 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4744 enable I2C microcode relocation patch (MPC8xx);
4745 define relocation offset in DPRAM [DSP2]
4747 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4748 enable SMC microcode relocation patch (MPC8xx);
4749 define relocation offset in DPRAM [SMC1]
4751 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4752 enable SPI microcode relocation patch (MPC8xx);
4753 define relocation offset in DPRAM [SCC4]
4755 - CONFIG_SYS_USE_OSCCLK:
4756 Use OSCM clock mode on MBX8xx board. Be careful,
4757 wrong setting might damage your board. Read
4758 doc/README.MBX before setting this variable!
4760 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4761 Offset of the bootmode word in DPRAM used by post
4762 (Power On Self Tests). This definition overrides
4763 #define'd default value in commproc.h resp.
4766 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4767 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4768 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4769 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4770 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4771 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4772 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4773 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4774 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4776 - CONFIG_PCI_DISABLE_PCIE:
4777 Disable PCI-Express on systems where it is supported but not
4780 - CONFIG_PCI_ENUM_ONLY
4781 Only scan through and get the devices on the buses.
4782 Don't do any setup work, presumably because someone or
4783 something has already done it, and we don't need to do it
4784 a second time. Useful for platforms that are pre-booted
4785 by coreboot or similar.
4787 - CONFIG_PCI_INDIRECT_BRIDGE:
4788 Enable support for indirect PCI bridges.
4791 Chip has SRIO or not
4794 Board has SRIO 1 port available
4797 Board has SRIO 2 port available
4799 - CONFIG_SRIO_PCIE_BOOT_MASTER
4800 Board can support master function for Boot from SRIO and PCIE
4802 - CONFIG_SYS_SRIOn_MEM_VIRT:
4803 Virtual Address of SRIO port 'n' memory region
4805 - CONFIG_SYS_SRIOn_MEM_PHYS:
4806 Physical Address of SRIO port 'n' memory region
4808 - CONFIG_SYS_SRIOn_MEM_SIZE:
4809 Size of SRIO port 'n' memory region
4811 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4812 Defined to tell the NAND controller that the NAND chip is using
4814 Not all NAND drivers use this symbol.
4815 Example of drivers that use it:
4816 - drivers/mtd/nand/ndfc.c
4817 - drivers/mtd/nand/mxc_nand.c
4819 - CONFIG_SYS_NDFC_EBC0_CFG
4820 Sets the EBC0_CFG register for the NDFC. If not defined
4821 a default value will be used.
4824 Get DDR timing information from an I2C EEPROM. Common
4825 with pluggable memory modules such as SODIMMs
4828 I2C address of the SPD EEPROM
4830 - CONFIG_SYS_SPD_BUS_NUM
4831 If SPD EEPROM is on an I2C bus other than the first
4832 one, specify here. Note that the value must resolve
4833 to something your driver can deal with.
4835 - CONFIG_SYS_DDR_RAW_TIMING
4836 Get DDR timing information from other than SPD. Common with
4837 soldered DDR chips onboard without SPD. DDR raw timing
4838 parameters are extracted from datasheet and hard-coded into
4839 header files or board specific files.
4841 - CONFIG_FSL_DDR_INTERACTIVE
4842 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4844 - CONFIG_FSL_DDR_SYNC_REFRESH
4845 Enable sync of refresh for multiple controllers.
4847 - CONFIG_FSL_DDR_BIST
4848 Enable built-in memory test for Freescale DDR controllers.
4850 - CONFIG_SYS_83XX_DDR_USES_CS0
4851 Only for 83xx systems. If specified, then DDR should
4852 be configured using CS0 and CS1 instead of CS2 and CS3.
4854 - CONFIG_ETHER_ON_FEC[12]
4855 Define to enable FEC[12] on a 8xx series processor.
4857 - CONFIG_FEC[12]_PHY
4858 Define to the hardcoded PHY address which corresponds
4859 to the given FEC; i. e.
4860 #define CONFIG_FEC1_PHY 4
4861 means that the PHY with address 4 is connected to FEC1
4863 When set to -1, means to probe for first available.
4865 - CONFIG_FEC[12]_PHY_NORXERR
4866 The PHY does not have a RXERR line (RMII only).
4867 (so program the FEC to ignore it).
4870 Enable RMII mode for all FECs.
4871 Note that this is a global option, we can't
4872 have one FEC in standard MII mode and another in RMII mode.
4874 - CONFIG_CRC32_VERIFY
4875 Add a verify option to the crc32 command.
4878 => crc32 -v <address> <count> <crc32>
4880 Where address/count indicate a memory area
4881 and crc32 is the correct crc32 which the
4885 Add the "loopw" memory command. This only takes effect if
4886 the memory commands are activated globally (CONFIG_CMD_MEM).
4889 Add the "mdc" and "mwc" memory commands. These are cyclic
4894 This command will print 4 bytes (10,11,12,13) each 500 ms.
4896 => mwc.l 100 12345678 10
4897 This command will write 12345678 to address 100 all 10 ms.
4899 This only takes effect if the memory commands are activated
4900 globally (CONFIG_CMD_MEM).
4902 - CONFIG_SKIP_LOWLEVEL_INIT
4903 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4904 low level initializations (like setting up the memory
4905 controller) are omitted and/or U-Boot does not
4906 relocate itself into RAM.
4908 Normally this variable MUST NOT be defined. The only
4909 exception is when U-Boot is loaded (to RAM) by some
4910 other boot loader or by a debugger which performs
4911 these initializations itself.
4914 Modifies the behaviour of start.S when compiling a loader
4915 that is executed before the actual U-Boot. E.g. when
4916 compiling a NAND SPL.
4919 Modifies the behaviour of start.S when compiling a loader
4920 that is executed after the SPL and before the actual U-Boot.
4921 It is loaded by the SPL.
4923 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4924 Only for 85xx systems. If this variable is specified, the section
4925 .resetvec is not kept and the section .bootpg is placed in the
4926 previous 4k of the .text section.
4928 - CONFIG_ARCH_MAP_SYSMEM
4929 Generally U-Boot (and in particular the md command) uses
4930 effective address. It is therefore not necessary to regard
4931 U-Boot address as virtual addresses that need to be translated
4932 to physical addresses. However, sandbox requires this, since
4933 it maintains its own little RAM buffer which contains all
4934 addressable memory. This option causes some memory accesses
4935 to be mapped through map_sysmem() / unmap_sysmem().
4937 - CONFIG_USE_ARCH_MEMCPY
4938 CONFIG_USE_ARCH_MEMSET
4939 If these options are used a optimized version of memcpy/memset will
4940 be used if available. These functions may be faster under some
4941 conditions but may increase the binary size.
4943 - CONFIG_X86_RESET_VECTOR
4944 If defined, the x86 reset vector code is included. This is not
4945 needed when U-Boot is running from Coreboot.
4948 Defines the MPU clock speed (in MHz).
4950 NOTE : currently only supported on AM335x platforms.
4952 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4953 Enables the RTC32K OSC on AM33xx based plattforms
4955 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4956 Option to disable subpage write in NAND driver
4957 driver that uses this:
4958 drivers/mtd/nand/davinci_nand.c
4960 Freescale QE/FMAN Firmware Support:
4961 -----------------------------------
4963 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4964 loading of "firmware", which is encoded in the QE firmware binary format.
4965 This firmware often needs to be loaded during U-Boot booting, so macros
4966 are used to identify the storage device (NOR flash, SPI, etc) and the address
4969 - CONFIG_SYS_FMAN_FW_ADDR
4970 The address in the storage device where the FMAN microcode is located. The
4971 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4974 - CONFIG_SYS_QE_FW_ADDR
4975 The address in the storage device where the QE microcode is located. The
4976 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4979 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4980 The maximum possible size of the firmware. The firmware binary format
4981 has a field that specifies the actual size of the firmware, but it
4982 might not be possible to read any part of the firmware unless some
4983 local storage is allocated to hold the entire firmware first.
4985 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4986 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4987 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4988 virtual address in NOR flash.
4990 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4991 Specifies that QE/FMAN firmware is located in NAND flash.
4992 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4994 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4995 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4996 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4998 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4999 Specifies that QE/FMAN firmware is located on the primary SPI
5000 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5002 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5003 Specifies that QE/FMAN firmware is located in the remote (master)
5004 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5005 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5006 window->master inbound window->master LAW->the ucode address in
5007 master's memory space.
5009 Freescale Layerscape Management Complex Firmware Support:
5010 ---------------------------------------------------------
5011 The Freescale Layerscape Management Complex (MC) supports the loading of
5013 This firmware often needs to be loaded during U-Boot booting, so macros
5014 are used to identify the storage device (NOR flash, SPI, etc) and the address
5017 - CONFIG_FSL_MC_ENET
5018 Enable the MC driver for Layerscape SoCs.
5020 - CONFIG_SYS_LS_MC_FW_ADDR
5021 The address in the storage device where the firmware is located. The
5022 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5025 - CONFIG_SYS_LS_MC_FW_LENGTH
5026 The maximum possible size of the firmware. The firmware binary format
5027 has a field that specifies the actual size of the firmware, but it
5028 might not be possible to read any part of the firmware unless some
5029 local storage is allocated to hold the entire firmware first.
5031 - CONFIG_SYS_LS_MC_FW_IN_NOR
5032 Specifies that MC firmware is located in NOR flash, mapped as
5033 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5034 virtual address in NOR flash.
5036 Freescale Layerscape Debug Server Support:
5037 -------------------------------------------
5038 The Freescale Layerscape Debug Server Support supports the loading of
5039 "Debug Server firmware" and triggering SP boot-rom.
5040 This firmware often needs to be loaded during U-Boot booting.
5042 - CONFIG_FSL_DEBUG_SERVER
5043 Enable the Debug Server for Layerscape SoCs.
5045 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5046 Define minimum DDR size required for debug server image
5048 - CONFIG_SYS_MEM_TOP_HIDE_MIN
5049 Define minimum DDR size to be hided from top of the DDR memory
5054 In order to achieve reproducible builds, timestamps used in the U-Boot build
5055 process have to be set to a fixed value.
5057 This is done using the SOURCE_DATE_EPOCH environment variable.
5058 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5059 option for U-Boot or an environment variable in U-Boot.
5061 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5063 Building the Software:
5064 ======================
5066 Building U-Boot has been tested in several native build environments
5067 and in many different cross environments. Of course we cannot support
5068 all possibly existing versions of cross development tools in all
5069 (potentially obsolete) versions. In case of tool chain problems we
5070 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5071 which is extensively used to build and test U-Boot.
5073 If you are not using a native environment, it is assumed that you
5074 have GNU cross compiling tools available in your path. In this case,
5075 you must set the environment variable CROSS_COMPILE in your shell.
5076 Note that no changes to the Makefile or any other source files are
5077 necessary. For example using the ELDK on a 4xx CPU, please enter:
5079 $ CROSS_COMPILE=ppc_4xx-
5080 $ export CROSS_COMPILE
5082 Note: If you wish to generate Windows versions of the utilities in
5083 the tools directory you can use the MinGW toolchain
5084 (http://www.mingw.org). Set your HOST tools to the MinGW
5085 toolchain and execute 'make tools'. For example:
5087 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5089 Binaries such as tools/mkimage.exe will be created which can
5090 be executed on computers running Windows.
5092 U-Boot is intended to be simple to build. After installing the
5093 sources you must configure U-Boot for one specific board type. This
5098 where "NAME_defconfig" is the name of one of the existing configu-
5099 rations; see boards.cfg for supported names.
5101 Note: for some board special configuration names may exist; check if
5102 additional information is available from the board vendor; for
5103 instance, the TQM823L systems are available without (standard)
5104 or with LCD support. You can select such additional "features"
5105 when choosing the configuration, i. e.
5107 make TQM823L_defconfig
5108 - will configure for a plain TQM823L, i. e. no LCD support
5110 make TQM823L_LCD_defconfig
5111 - will configure for a TQM823L with U-Boot console on LCD
5116 Finally, type "make all", and you should get some working U-Boot
5117 images ready for download to / installation on your system:
5119 - "u-boot.bin" is a raw binary image
5120 - "u-boot" is an image in ELF binary format
5121 - "u-boot.srec" is in Motorola S-Record format
5123 By default the build is performed locally and the objects are saved
5124 in the source directory. One of the two methods can be used to change
5125 this behavior and build U-Boot to some external directory:
5127 1. Add O= to the make command line invocations:
5129 make O=/tmp/build distclean
5130 make O=/tmp/build NAME_defconfig
5131 make O=/tmp/build all
5133 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5135 export KBUILD_OUTPUT=/tmp/build
5140 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5144 Please be aware that the Makefiles assume you are using GNU make, so
5145 for instance on NetBSD you might need to use "gmake" instead of
5149 If the system board that you have is not listed, then you will need
5150 to port U-Boot to your hardware platform. To do this, follow these
5153 1. Add a new configuration option for your board to the toplevel
5154 "boards.cfg" file, using the existing entries as examples.
5155 Follow the instructions there to keep the boards in order.
5156 2. Create a new directory to hold your board specific code. Add any
5157 files you need. In your board directory, you will need at least
5158 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5159 3. Create a new configuration file "include/configs/<board>.h" for
5161 3. If you're porting U-Boot to a new CPU, then also create a new
5162 directory to hold your CPU specific code. Add any files you need.
5163 4. Run "make <board>_defconfig" with your new name.
5164 5. Type "make", and you should get a working "u-boot.srec" file
5165 to be installed on your target system.
5166 6. Debug and solve any problems that might arise.
5167 [Of course, this last step is much harder than it sounds.]
5170 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5171 ==============================================================
5173 If you have modified U-Boot sources (for instance added a new board
5174 or support for new devices, a new CPU, etc.) you are expected to
5175 provide feedback to the other developers. The feedback normally takes
5176 the form of a "patch", i. e. a context diff against a certain (latest
5177 official or latest in the git repository) version of U-Boot sources.
5179 But before you submit such a patch, please verify that your modifi-
5180 cation did not break existing code. At least make sure that *ALL* of
5181 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5182 just run the "MAKEALL" script, which will configure and build U-Boot
5183 for ALL supported system. Be warned, this will take a while. You can
5184 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5185 environment variable to the script, i. e. to use the ELDK cross tools
5188 CROSS_COMPILE=ppc_8xx- MAKEALL
5190 or to build on a native PowerPC system you can type
5192 CROSS_COMPILE=' ' MAKEALL
5194 When using the MAKEALL script, the default behaviour is to build
5195 U-Boot in the source directory. This location can be changed by
5196 setting the BUILD_DIR environment variable. Also, for each target
5197 built, the MAKEALL script saves two log files (<target>.ERR and
5198 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5199 location can be changed by setting the MAKEALL_LOGDIR environment
5200 variable. For example:
5202 export BUILD_DIR=/tmp/build
5203 export MAKEALL_LOGDIR=/tmp/log
5204 CROSS_COMPILE=ppc_8xx- MAKEALL
5206 With the above settings build objects are saved in the /tmp/build,
5207 log files are saved in the /tmp/log and the source tree remains clean
5208 during the whole build process.
5211 See also "U-Boot Porting Guide" below.
5214 Monitor Commands - Overview:
5215 ============================
5217 go - start application at address 'addr'
5218 run - run commands in an environment variable
5219 bootm - boot application image from memory
5220 bootp - boot image via network using BootP/TFTP protocol
5221 bootz - boot zImage from memory
5222 tftpboot- boot image via network using TFTP protocol
5223 and env variables "ipaddr" and "serverip"
5224 (and eventually "gatewayip")
5225 tftpput - upload a file via network using TFTP protocol
5226 rarpboot- boot image via network using RARP/TFTP protocol
5227 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5228 loads - load S-Record file over serial line
5229 loadb - load binary file over serial line (kermit mode)
5231 mm - memory modify (auto-incrementing)
5232 nm - memory modify (constant address)
5233 mw - memory write (fill)
5235 cmp - memory compare
5236 crc32 - checksum calculation
5237 i2c - I2C sub-system
5238 sspi - SPI utility commands
5239 base - print or set address offset
5240 printenv- print environment variables
5241 setenv - set environment variables
5242 saveenv - save environment variables to persistent storage
5243 protect - enable or disable FLASH write protection
5244 erase - erase FLASH memory
5245 flinfo - print FLASH memory information
5246 nand - NAND memory operations (see doc/README.nand)
5247 bdinfo - print Board Info structure
5248 iminfo - print header information for application image
5249 coninfo - print console devices and informations
5250 ide - IDE sub-system
5251 loop - infinite loop on address range
5252 loopw - infinite write loop on address range
5253 mtest - simple RAM test
5254 icache - enable or disable instruction cache
5255 dcache - enable or disable data cache
5256 reset - Perform RESET of the CPU
5257 echo - echo args to console
5258 version - print monitor version
5259 help - print online help
5260 ? - alias for 'help'
5263 Monitor Commands - Detailed Description:
5264 ========================================
5268 For now: just type "help <command>".
5271 Environment Variables:
5272 ======================
5274 U-Boot supports user configuration using Environment Variables which
5275 can be made persistent by saving to Flash memory.
5277 Environment Variables are set using "setenv", printed using
5278 "printenv", and saved to Flash using "saveenv". Using "setenv"
5279 without a value can be used to delete a variable from the
5280 environment. As long as you don't save the environment you are
5281 working with an in-memory copy. In case the Flash area containing the
5282 environment is erased by accident, a default environment is provided.
5284 Some configuration options can be set using Environment Variables.
5286 List of environment variables (most likely not complete):
5288 baudrate - see CONFIG_BAUDRATE
5290 bootdelay - see CONFIG_BOOTDELAY
5292 bootcmd - see CONFIG_BOOTCOMMAND
5294 bootargs - Boot arguments when booting an RTOS image
5296 bootfile - Name of the image to load with TFTP
5298 bootm_low - Memory range available for image processing in the bootm
5299 command can be restricted. This variable is given as
5300 a hexadecimal number and defines lowest address allowed
5301 for use by the bootm command. See also "bootm_size"
5302 environment variable. Address defined by "bootm_low" is
5303 also the base of the initial memory mapping for the Linux
5304 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5307 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5308 This variable is given as a hexadecimal number and it
5309 defines the size of the memory region starting at base
5310 address bootm_low that is accessible by the Linux kernel
5311 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5312 as the default value if it is defined, and bootm_size is
5315 bootm_size - Memory range available for image processing in the bootm
5316 command can be restricted. This variable is given as
5317 a hexadecimal number and defines the size of the region
5318 allowed for use by the bootm command. See also "bootm_low"
5319 environment variable.
5321 updatefile - Location of the software update file on a TFTP server, used
5322 by the automatic software update feature. Please refer to
5323 documentation in doc/README.update for more details.
5325 autoload - if set to "no" (any string beginning with 'n'),
5326 "bootp" will just load perform a lookup of the
5327 configuration from the BOOTP server, but not try to
5328 load any image using TFTP
5330 autostart - if set to "yes", an image loaded using the "bootp",
5331 "rarpboot", "tftpboot" or "diskboot" commands will
5332 be automatically started (by internally calling
5335 If set to "no", a standalone image passed to the
5336 "bootm" command will be copied to the load address
5337 (and eventually uncompressed), but NOT be started.
5338 This can be used to load and uncompress arbitrary
5341 fdt_high - if set this restricts the maximum address that the
5342 flattened device tree will be copied into upon boot.
5343 For example, if you have a system with 1 GB memory
5344 at physical address 0x10000000, while Linux kernel
5345 only recognizes the first 704 MB as low memory, you
5346 may need to set fdt_high as 0x3C000000 to have the
5347 device tree blob be copied to the maximum address
5348 of the 704 MB low memory, so that Linux kernel can
5349 access it during the boot procedure.
5351 If this is set to the special value 0xFFFFFFFF then
5352 the fdt will not be copied at all on boot. For this
5353 to work it must reside in writable memory, have
5354 sufficient padding on the end of it for u-boot to
5355 add the information it needs into it, and the memory
5356 must be accessible by the kernel.
5358 fdtcontroladdr- if set this is the address of the control flattened
5359 device tree used by U-Boot when CONFIG_OF_CONTROL is
5362 i2cfast - (PPC405GP|PPC405EP only)
5363 if set to 'y' configures Linux I2C driver for fast
5364 mode (400kHZ). This environment variable is used in
5365 initialization code. So, for changes to be effective
5366 it must be saved and board must be reset.
5368 initrd_high - restrict positioning of initrd images:
5369 If this variable is not set, initrd images will be
5370 copied to the highest possible address in RAM; this
5371 is usually what you want since it allows for
5372 maximum initrd size. If for some reason you want to
5373 make sure that the initrd image is loaded below the
5374 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5375 variable to a value of "no" or "off" or "0".
5376 Alternatively, you can set it to a maximum upper
5377 address to use (U-Boot will still check that it
5378 does not overwrite the U-Boot stack and data).
5380 For instance, when you have a system with 16 MB
5381 RAM, and want to reserve 4 MB from use by Linux,
5382 you can do this by adding "mem=12M" to the value of
5383 the "bootargs" variable. However, now you must make
5384 sure that the initrd image is placed in the first
5385 12 MB as well - this can be done with
5387 setenv initrd_high 00c00000
5389 If you set initrd_high to 0xFFFFFFFF, this is an
5390 indication to U-Boot that all addresses are legal
5391 for the Linux kernel, including addresses in flash
5392 memory. In this case U-Boot will NOT COPY the
5393 ramdisk at all. This may be useful to reduce the
5394 boot time on your system, but requires that this
5395 feature is supported by your Linux kernel.
5397 ipaddr - IP address; needed for tftpboot command
5399 loadaddr - Default load address for commands like "bootp",
5400 "rarpboot", "tftpboot", "loadb" or "diskboot"
5402 loads_echo - see CONFIG_LOADS_ECHO
5404 serverip - TFTP server IP address; needed for tftpboot command
5406 bootretry - see CONFIG_BOOT_RETRY_TIME
5408 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5410 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5412 ethprime - controls which interface is used first.
5414 ethact - controls which interface is currently active.
5415 For example you can do the following
5417 => setenv ethact FEC
5418 => ping 192.168.0.1 # traffic sent on FEC
5419 => setenv ethact SCC
5420 => ping 10.0.0.1 # traffic sent on SCC
5422 ethrotate - When set to "no" U-Boot does not go through all
5423 available network interfaces.
5424 It just stays at the currently selected interface.
5426 netretry - When set to "no" each network operation will
5427 either succeed or fail without retrying.
5428 When set to "once" the network operation will
5429 fail when all the available network interfaces
5430 are tried once without success.
5431 Useful on scripts which control the retry operation
5434 npe_ucode - set load address for the NPE microcode
5436 silent_linux - If set then Linux will be told to boot silently, by
5437 changing the console to be empty. If "yes" it will be
5438 made silent. If "no" it will not be made silent. If
5439 unset, then it will be made silent if the U-Boot console
5442 tftpsrcp - If this is set, the value is used for TFTP's
5445 tftpdstp - If this is set, the value is used for TFTP's UDP
5446 destination port instead of the Well Know Port 69.
5448 tftpblocksize - Block size to use for TFTP transfers; if not set,
5449 we use the TFTP server's default block size
5451 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5452 seconds, minimum value is 1000 = 1 second). Defines
5453 when a packet is considered to be lost so it has to
5454 be retransmitted. The default is 5000 = 5 seconds.
5455 Lowering this value may make downloads succeed
5456 faster in networks with high packet loss rates or
5457 with unreliable TFTP servers.
5459 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5460 unit, minimum value = 0). Defines how many timeouts
5461 can happen during a single file transfer before that
5462 transfer is aborted. The default is 10, and 0 means
5463 'no timeouts allowed'. Increasing this value may help
5464 downloads succeed with high packet loss rates, or with
5465 unreliable TFTP servers or client hardware.
5467 vlan - When set to a value < 4095 the traffic over
5468 Ethernet is encapsulated/received over 802.1q
5471 The following image location variables contain the location of images
5472 used in booting. The "Image" column gives the role of the image and is
5473 not an environment variable name. The other columns are environment
5474 variable names. "File Name" gives the name of the file on a TFTP
5475 server, "RAM Address" gives the location in RAM the image will be
5476 loaded to, and "Flash Location" gives the image's address in NOR
5477 flash or offset in NAND flash.
5479 *Note* - these variables don't have to be defined for all boards, some
5480 boards currently use other variables for these purposes, and some
5481 boards use these variables for other purposes.
5483 Image File Name RAM Address Flash Location
5484 ----- --------- ----------- --------------
5485 u-boot u-boot u-boot_addr_r u-boot_addr
5486 Linux kernel bootfile kernel_addr_r kernel_addr
5487 device tree blob fdtfile fdt_addr_r fdt_addr
5488 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5490 The following environment variables may be used and automatically
5491 updated by the network boot commands ("bootp" and "rarpboot"),
5492 depending the information provided by your boot server:
5494 bootfile - see above
5495 dnsip - IP address of your Domain Name Server
5496 dnsip2 - IP address of your secondary Domain Name Server
5497 gatewayip - IP address of the Gateway (Router) to use
5498 hostname - Target hostname
5500 netmask - Subnet Mask
5501 rootpath - Pathname of the root filesystem on the NFS server
5502 serverip - see above
5505 There are two special Environment Variables:
5507 serial# - contains hardware identification information such
5508 as type string and/or serial number
5509 ethaddr - Ethernet address
5511 These variables can be set only once (usually during manufacturing of
5512 the board). U-Boot refuses to delete or overwrite these variables
5513 once they have been set once.
5516 Further special Environment Variables:
5518 ver - Contains the U-Boot version string as printed
5519 with the "version" command. This variable is
5520 readonly (see CONFIG_VERSION_VARIABLE).
5523 Please note that changes to some configuration parameters may take
5524 only effect after the next boot (yes, that's just like Windoze :-).
5527 Callback functions for environment variables:
5528 ---------------------------------------------
5530 For some environment variables, the behavior of u-boot needs to change
5531 when their values are changed. This functionality allows functions to
5532 be associated with arbitrary variables. On creation, overwrite, or
5533 deletion, the callback will provide the opportunity for some side
5534 effect to happen or for the change to be rejected.
5536 The callbacks are named and associated with a function using the
5537 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5539 These callbacks are associated with variables in one of two ways. The
5540 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5541 in the board configuration to a string that defines a list of
5542 associations. The list must be in the following format:
5544 entry = variable_name[:callback_name]
5547 If the callback name is not specified, then the callback is deleted.
5548 Spaces are also allowed anywhere in the list.
5550 Callbacks can also be associated by defining the ".callbacks" variable
5551 with the same list format above. Any association in ".callbacks" will
5552 override any association in the static list. You can define
5553 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5554 ".callbacks" environment variable in the default or embedded environment.
5556 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5557 regular expression. This allows multiple variables to be connected to
5558 the same callback without explicitly listing them all out.
5561 Command Line Parsing:
5562 =====================
5564 There are two different command line parsers available with U-Boot:
5565 the old "simple" one, and the much more powerful "hush" shell:
5567 Old, simple command line parser:
5568 --------------------------------
5570 - supports environment variables (through setenv / saveenv commands)
5571 - several commands on one line, separated by ';'
5572 - variable substitution using "... ${name} ..." syntax
5573 - special characters ('$', ';') can be escaped by prefixing with '\',
5575 setenv bootcmd bootm \${address}
5576 - You can also escape text by enclosing in single apostrophes, for example:
5577 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5582 - similar to Bourne shell, with control structures like
5583 if...then...else...fi, for...do...done; while...do...done,
5584 until...do...done, ...
5585 - supports environment ("global") variables (through setenv / saveenv
5586 commands) and local shell variables (through standard shell syntax
5587 "name=value"); only environment variables can be used with "run"
5593 (1) If a command line (or an environment variable executed by a "run"
5594 command) contains several commands separated by semicolon, and
5595 one of these commands fails, then the remaining commands will be
5598 (2) If you execute several variables with one call to run (i. e.
5599 calling run with a list of variables as arguments), any failing
5600 command will cause "run" to terminate, i. e. the remaining
5601 variables are not executed.
5603 Note for Redundant Ethernet Interfaces:
5604 =======================================
5606 Some boards come with redundant Ethernet interfaces; U-Boot supports
5607 such configurations and is capable of automatic selection of a
5608 "working" interface when needed. MAC assignment works as follows:
5610 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5611 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5612 "eth1addr" (=>eth1), "eth2addr", ...
5614 If the network interface stores some valid MAC address (for instance
5615 in SROM), this is used as default address if there is NO correspon-
5616 ding setting in the environment; if the corresponding environment
5617 variable is set, this overrides the settings in the card; that means:
5619 o If the SROM has a valid MAC address, and there is no address in the
5620 environment, the SROM's address is used.
5622 o If there is no valid address in the SROM, and a definition in the
5623 environment exists, then the value from the environment variable is
5626 o If both the SROM and the environment contain a MAC address, and
5627 both addresses are the same, this MAC address is used.
5629 o If both the SROM and the environment contain a MAC address, and the
5630 addresses differ, the value from the environment is used and a
5633 o If neither SROM nor the environment contain a MAC address, an error
5634 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5635 a random, locally-assigned MAC is used.
5637 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5638 will be programmed into hardware as part of the initialization process. This
5639 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5640 The naming convention is as follows:
5641 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5646 U-Boot is capable of booting (and performing other auxiliary operations on)
5647 images in two formats:
5649 New uImage format (FIT)
5650 -----------------------
5652 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5653 to Flattened Device Tree). It allows the use of images with multiple
5654 components (several kernels, ramdisks, etc.), with contents protected by
5655 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5661 Old image format is based on binary files which can be basically anything,
5662 preceded by a special header; see the definitions in include/image.h for
5663 details; basically, the header defines the following image properties:
5665 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5666 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5667 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5668 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5670 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5671 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5672 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5673 * Compression Type (uncompressed, gzip, bzip2)
5679 The header is marked by a special Magic Number, and both the header
5680 and the data portions of the image are secured against corruption by
5687 Although U-Boot should support any OS or standalone application
5688 easily, the main focus has always been on Linux during the design of
5691 U-Boot includes many features that so far have been part of some
5692 special "boot loader" code within the Linux kernel. Also, any
5693 "initrd" images to be used are no longer part of one big Linux image;
5694 instead, kernel and "initrd" are separate images. This implementation
5695 serves several purposes:
5697 - the same features can be used for other OS or standalone
5698 applications (for instance: using compressed images to reduce the
5699 Flash memory footprint)
5701 - it becomes much easier to port new Linux kernel versions because
5702 lots of low-level, hardware dependent stuff are done by U-Boot
5704 - the same Linux kernel image can now be used with different "initrd"
5705 images; of course this also means that different kernel images can
5706 be run with the same "initrd". This makes testing easier (you don't
5707 have to build a new "zImage.initrd" Linux image when you just
5708 change a file in your "initrd"). Also, a field-upgrade of the
5709 software is easier now.
5715 Porting Linux to U-Boot based systems:
5716 ---------------------------------------
5718 U-Boot cannot save you from doing all the necessary modifications to
5719 configure the Linux device drivers for use with your target hardware
5720 (no, we don't intend to provide a full virtual machine interface to
5723 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5725 Just make sure your machine specific header file (for instance
5726 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5727 Information structure as we define in include/asm-<arch>/u-boot.h,
5728 and make sure that your definition of IMAP_ADDR uses the same value
5729 as your U-Boot configuration in CONFIG_SYS_IMMR.
5731 Note that U-Boot now has a driver model, a unified model for drivers.
5732 If you are adding a new driver, plumb it into driver model. If there
5733 is no uclass available, you are encouraged to create one. See
5737 Configuring the Linux kernel:
5738 -----------------------------
5740 No specific requirements for U-Boot. Make sure you have some root
5741 device (initial ramdisk, NFS) for your target system.
5744 Building a Linux Image:
5745 -----------------------
5747 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5748 not used. If you use recent kernel source, a new build target
5749 "uImage" will exist which automatically builds an image usable by
5750 U-Boot. Most older kernels also have support for a "pImage" target,
5751 which was introduced for our predecessor project PPCBoot and uses a
5752 100% compatible format.
5756 make TQM850L_defconfig
5761 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5762 encapsulate a compressed Linux kernel image with header information,
5763 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5765 * build a standard "vmlinux" kernel image (in ELF binary format):
5767 * convert the kernel into a raw binary image:
5769 ${CROSS_COMPILE}-objcopy -O binary \
5770 -R .note -R .comment \
5771 -S vmlinux linux.bin
5773 * compress the binary image:
5777 * package compressed binary image for U-Boot:
5779 mkimage -A ppc -O linux -T kernel -C gzip \
5780 -a 0 -e 0 -n "Linux Kernel Image" \
5781 -d linux.bin.gz uImage
5784 The "mkimage" tool can also be used to create ramdisk images for use
5785 with U-Boot, either separated from the Linux kernel image, or
5786 combined into one file. "mkimage" encapsulates the images with a 64
5787 byte header containing information about target architecture,
5788 operating system, image type, compression method, entry points, time
5789 stamp, CRC32 checksums, etc.
5791 "mkimage" can be called in two ways: to verify existing images and
5792 print the header information, or to build new images.
5794 In the first form (with "-l" option) mkimage lists the information
5795 contained in the header of an existing U-Boot image; this includes
5796 checksum verification:
5798 tools/mkimage -l image
5799 -l ==> list image header information
5801 The second form (with "-d" option) is used to build a U-Boot image
5802 from a "data file" which is used as image payload:
5804 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5805 -n name -d data_file image
5806 -A ==> set architecture to 'arch'
5807 -O ==> set operating system to 'os'
5808 -T ==> set image type to 'type'
5809 -C ==> set compression type 'comp'
5810 -a ==> set load address to 'addr' (hex)
5811 -e ==> set entry point to 'ep' (hex)
5812 -n ==> set image name to 'name'
5813 -d ==> use image data from 'datafile'
5815 Right now, all Linux kernels for PowerPC systems use the same load
5816 address (0x00000000), but the entry point address depends on the
5819 - 2.2.x kernels have the entry point at 0x0000000C,
5820 - 2.3.x and later kernels have the entry point at 0x00000000.
5822 So a typical call to build a U-Boot image would read:
5824 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5825 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5826 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5827 > examples/uImage.TQM850L
5828 Image Name: 2.4.4 kernel for TQM850L
5829 Created: Wed Jul 19 02:34:59 2000
5830 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5831 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5832 Load Address: 0x00000000
5833 Entry Point: 0x00000000
5835 To verify the contents of the image (or check for corruption):
5837 -> tools/mkimage -l 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 NOTE: for embedded systems where boot time is critical you can trade
5846 speed for memory and install an UNCOMPRESSED image instead: this
5847 needs more space in Flash, but boots much faster since it does not
5848 need to be uncompressed:
5850 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5851 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5852 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5853 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5854 > examples/uImage.TQM850L-uncompressed
5855 Image Name: 2.4.4 kernel for TQM850L
5856 Created: Wed Jul 19 02:34:59 2000
5857 Image Type: PowerPC Linux Kernel Image (uncompressed)
5858 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5859 Load Address: 0x00000000
5860 Entry Point: 0x00000000
5863 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5864 when your kernel is intended to use an initial ramdisk:
5866 -> tools/mkimage -n 'Simple Ramdisk Image' \
5867 > -A ppc -O linux -T ramdisk -C gzip \
5868 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5869 Image Name: Simple Ramdisk Image
5870 Created: Wed Jan 12 14:01:50 2000
5871 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5872 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5873 Load Address: 0x00000000
5874 Entry Point: 0x00000000
5876 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5877 option performs the converse operation of the mkimage's second form (the "-d"
5878 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5881 tools/dumpimage -i image -T type -p position data_file
5882 -i ==> extract from the 'image' a specific 'data_file'
5883 -T ==> set image type to 'type'
5884 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5887 Installing a Linux Image:
5888 -------------------------
5890 To downloading a U-Boot image over the serial (console) interface,
5891 you must convert the image to S-Record format:
5893 objcopy -I binary -O srec examples/image examples/image.srec
5895 The 'objcopy' does not understand the information in the U-Boot
5896 image header, so the resulting S-Record file will be relative to
5897 address 0x00000000. To load it to a given address, you need to
5898 specify the target address as 'offset' parameter with the 'loads'
5901 Example: install the image to address 0x40100000 (which on the
5902 TQM8xxL is in the first Flash bank):
5904 => erase 40100000 401FFFFF
5910 ## Ready for S-Record download ...
5911 ~>examples/image.srec
5912 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5914 15989 15990 15991 15992
5915 [file transfer complete]
5917 ## Start Addr = 0x00000000
5920 You can check the success of the download using the 'iminfo' command;
5921 this includes a checksum verification so you can be sure no data
5922 corruption happened:
5926 ## Checking Image at 40100000 ...
5927 Image Name: 2.2.13 for initrd on TQM850L
5928 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5929 Data Size: 335725 Bytes = 327 kB = 0 MB
5930 Load Address: 00000000
5931 Entry Point: 0000000c
5932 Verifying Checksum ... OK
5938 The "bootm" command is used to boot an application that is stored in
5939 memory (RAM or Flash). In case of a Linux kernel image, the contents
5940 of the "bootargs" environment variable is passed to the kernel as
5941 parameters. You can check and modify this variable using the
5942 "printenv" and "setenv" commands:
5945 => printenv bootargs
5946 bootargs=root=/dev/ram
5948 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5950 => printenv bootargs
5951 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5954 ## Booting Linux kernel at 40020000 ...
5955 Image Name: 2.2.13 for NFS on TQM850L
5956 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5957 Data Size: 381681 Bytes = 372 kB = 0 MB
5958 Load Address: 00000000
5959 Entry Point: 0000000c
5960 Verifying Checksum ... OK
5961 Uncompressing Kernel Image ... OK
5962 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
5963 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5964 time_init: decrementer frequency = 187500000/60
5965 Calibrating delay loop... 49.77 BogoMIPS
5966 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5969 If you want to boot a Linux kernel with initial RAM disk, you pass
5970 the memory addresses of both the kernel and the initrd image (PPBCOOT
5971 format!) to the "bootm" command:
5973 => imi 40100000 40200000
5975 ## Checking Image at 40100000 ...
5976 Image Name: 2.2.13 for initrd on TQM850L
5977 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5978 Data Size: 335725 Bytes = 327 kB = 0 MB
5979 Load Address: 00000000
5980 Entry Point: 0000000c
5981 Verifying Checksum ... OK
5983 ## Checking Image at 40200000 ...
5984 Image Name: Simple Ramdisk Image
5985 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5986 Data Size: 566530 Bytes = 553 kB = 0 MB
5987 Load Address: 00000000
5988 Entry Point: 00000000
5989 Verifying Checksum ... OK
5991 => bootm 40100000 40200000
5992 ## Booting Linux kernel at 40100000 ...
5993 Image Name: 2.2.13 for initrd on TQM850L
5994 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5995 Data Size: 335725 Bytes = 327 kB = 0 MB
5996 Load Address: 00000000
5997 Entry Point: 0000000c
5998 Verifying Checksum ... OK
5999 Uncompressing Kernel Image ... OK
6000 ## Loading RAMDisk Image at 40200000 ...
6001 Image Name: Simple Ramdisk Image
6002 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6003 Data Size: 566530 Bytes = 553 kB = 0 MB
6004 Load Address: 00000000
6005 Entry Point: 00000000
6006 Verifying Checksum ... OK
6007 Loading Ramdisk ... OK
6008 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
6009 Boot arguments: root=/dev/ram
6010 time_init: decrementer frequency = 187500000/60
6011 Calibrating delay loop... 49.77 BogoMIPS
6013 RAMDISK: Compressed image found at block 0
6014 VFS: Mounted root (ext2 filesystem).
6018 Boot Linux and pass a flat device tree:
6021 First, U-Boot must be compiled with the appropriate defines. See the section
6022 titled "Linux Kernel Interface" above for a more in depth explanation. The
6023 following is an example of how to start a kernel and pass an updated
6029 oft=oftrees/mpc8540ads.dtb
6030 => tftp $oftaddr $oft
6031 Speed: 1000, full duplex
6033 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6034 Filename 'oftrees/mpc8540ads.dtb'.
6035 Load address: 0x300000
6038 Bytes transferred = 4106 (100a hex)
6039 => tftp $loadaddr $bootfile
6040 Speed: 1000, full duplex
6042 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6044 Load address: 0x200000
6045 Loading:############
6047 Bytes transferred = 1029407 (fb51f hex)
6052 => bootm $loadaddr - $oftaddr
6053 ## Booting image at 00200000 ...
6054 Image Name: Linux-2.6.17-dirty
6055 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6056 Data Size: 1029343 Bytes = 1005.2 kB
6057 Load Address: 00000000
6058 Entry Point: 00000000
6059 Verifying Checksum ... OK
6060 Uncompressing Kernel Image ... OK
6061 Booting using flat device tree at 0x300000
6062 Using MPC85xx ADS machine description
6063 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6067 More About U-Boot Image Types:
6068 ------------------------------
6070 U-Boot supports the following image types:
6072 "Standalone Programs" are directly runnable in the environment
6073 provided by U-Boot; it is expected that (if they behave
6074 well) you can continue to work in U-Boot after return from
6075 the Standalone Program.
6076 "OS Kernel Images" are usually images of some Embedded OS which
6077 will take over control completely. Usually these programs
6078 will install their own set of exception handlers, device
6079 drivers, set up the MMU, etc. - this means, that you cannot
6080 expect to re-enter U-Boot except by resetting the CPU.
6081 "RAMDisk Images" are more or less just data blocks, and their
6082 parameters (address, size) are passed to an OS kernel that is
6084 "Multi-File Images" contain several images, typically an OS
6085 (Linux) kernel image and one or more data images like
6086 RAMDisks. This construct is useful for instance when you want
6087 to boot over the network using BOOTP etc., where the boot
6088 server provides just a single image file, but you want to get
6089 for instance an OS kernel and a RAMDisk image.
6091 "Multi-File Images" start with a list of image sizes, each
6092 image size (in bytes) specified by an "uint32_t" in network
6093 byte order. This list is terminated by an "(uint32_t)0".
6094 Immediately after the terminating 0 follow the images, one by
6095 one, all aligned on "uint32_t" boundaries (size rounded up to
6096 a multiple of 4 bytes).
6098 "Firmware Images" are binary images containing firmware (like
6099 U-Boot or FPGA images) which usually will be programmed to
6102 "Script files" are command sequences that will be executed by
6103 U-Boot's command interpreter; this feature is especially
6104 useful when you configure U-Boot to use a real shell (hush)
6105 as command interpreter.
6107 Booting the Linux zImage:
6108 -------------------------
6110 On some platforms, it's possible to boot Linux zImage. This is done
6111 using the "bootz" command. The syntax of "bootz" command is the same
6112 as the syntax of "bootm" command.
6114 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6115 kernel with raw initrd images. The syntax is slightly different, the
6116 address of the initrd must be augmented by it's size, in the following
6117 format: "<initrd addres>:<initrd size>".
6123 One of the features of U-Boot is that you can dynamically load and
6124 run "standalone" applications, which can use some resources of
6125 U-Boot like console I/O functions or interrupt services.
6127 Two simple examples are included with the sources:
6132 'examples/hello_world.c' contains a small "Hello World" Demo
6133 application; it is automatically compiled when you build U-Boot.
6134 It's configured to run at address 0x00040004, so you can play with it
6138 ## Ready for S-Record download ...
6139 ~>examples/hello_world.srec
6140 1 2 3 4 5 6 7 8 9 10 11 ...
6141 [file transfer complete]
6143 ## Start Addr = 0x00040004
6145 => go 40004 Hello World! This is a test.
6146 ## Starting application at 0x00040004 ...
6157 Hit any key to exit ...
6159 ## Application terminated, rc = 0x0
6161 Another example, which demonstrates how to register a CPM interrupt
6162 handler with the U-Boot code, can be found in 'examples/timer.c'.
6163 Here, a CPM timer is set up to generate an interrupt every second.
6164 The interrupt service routine is trivial, just printing a '.'
6165 character, but this is just a demo program. The application can be
6166 controlled by the following keys:
6168 ? - print current values og the CPM Timer registers
6169 b - enable interrupts and start timer
6170 e - stop timer and disable interrupts
6171 q - quit application
6174 ## Ready for S-Record download ...
6175 ~>examples/timer.srec
6176 1 2 3 4 5 6 7 8 9 10 11 ...
6177 [file transfer complete]
6179 ## Start Addr = 0x00040004
6182 ## Starting application at 0x00040004 ...
6185 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6188 [q, b, e, ?] Set interval 1000000 us
6191 [q, b, e, ?] ........
6192 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6195 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6198 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6201 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6203 [q, b, e, ?] ...Stopping timer
6205 [q, b, e, ?] ## Application terminated, rc = 0x0
6211 Over time, many people have reported problems when trying to use the
6212 "minicom" terminal emulation program for serial download. I (wd)
6213 consider minicom to be broken, and recommend not to use it. Under
6214 Unix, I recommend to use C-Kermit for general purpose use (and
6215 especially for kermit binary protocol download ("loadb" command), and
6216 use "cu" for S-Record download ("loads" command). See
6217 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6218 for help with kermit.
6221 Nevertheless, if you absolutely want to use it try adding this
6222 configuration to your "File transfer protocols" section:
6224 Name Program Name U/D FullScr IO-Red. Multi
6225 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6226 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6232 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6233 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6235 Building requires a cross environment; it is known to work on
6236 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6237 need gmake since the Makefiles are not compatible with BSD make).
6238 Note that the cross-powerpc package does not install include files;
6239 attempting to build U-Boot will fail because <machine/ansi.h> is
6240 missing. This file has to be installed and patched manually:
6242 # cd /usr/pkg/cross/powerpc-netbsd/include
6244 # ln -s powerpc machine
6245 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6246 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6248 Native builds *don't* work due to incompatibilities between native
6249 and U-Boot include files.
6251 Booting assumes that (the first part of) the image booted is a
6252 stage-2 loader which in turn loads and then invokes the kernel
6253 proper. Loader sources will eventually appear in the NetBSD source
6254 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6255 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6258 Implementation Internals:
6259 =========================
6261 The following is not intended to be a complete description of every
6262 implementation detail. However, it should help to understand the
6263 inner workings of U-Boot and make it easier to port it to custom
6267 Initial Stack, Global Data:
6268 ---------------------------
6270 The implementation of U-Boot is complicated by the fact that U-Boot
6271 starts running out of ROM (flash memory), usually without access to
6272 system RAM (because the memory controller is not initialized yet).
6273 This means that we don't have writable Data or BSS segments, and BSS
6274 is not initialized as zero. To be able to get a C environment working
6275 at all, we have to allocate at least a minimal stack. Implementation
6276 options for this are defined and restricted by the CPU used: Some CPU
6277 models provide on-chip memory (like the IMMR area on MPC8xx and
6278 MPC826x processors), on others (parts of) the data cache can be
6279 locked as (mis-) used as memory, etc.
6281 Chris Hallinan posted a good summary of these issues to the
6282 U-Boot mailing list:
6284 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6285 From: "Chris Hallinan" <clh@net1plus.com>
6286 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6289 Correct me if I'm wrong, folks, but the way I understand it
6290 is this: Using DCACHE as initial RAM for Stack, etc, does not
6291 require any physical RAM backing up the cache. The cleverness
6292 is that the cache is being used as a temporary supply of
6293 necessary storage before the SDRAM controller is setup. It's
6294 beyond the scope of this list to explain the details, but you
6295 can see how this works by studying the cache architecture and
6296 operation in the architecture and processor-specific manuals.
6298 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6299 is another option for the system designer to use as an
6300 initial stack/RAM area prior to SDRAM being available. Either
6301 option should work for you. Using CS 4 should be fine if your
6302 board designers haven't used it for something that would
6303 cause you grief during the initial boot! It is frequently not
6306 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6307 with your processor/board/system design. The default value
6308 you will find in any recent u-boot distribution in
6309 walnut.h should work for you. I'd set it to a value larger
6310 than your SDRAM module. If you have a 64MB SDRAM module, set
6311 it above 400_0000. Just make sure your board has no resources
6312 that are supposed to respond to that address! That code in
6313 start.S has been around a while and should work as is when
6314 you get the config right.
6319 It is essential to remember this, since it has some impact on the C
6320 code for the initialization procedures:
6322 * Initialized global data (data segment) is read-only. Do not attempt
6325 * Do not use any uninitialized global data (or implicitly initialized
6326 as zero data - BSS segment) at all - this is undefined, initiali-
6327 zation is performed later (when relocating to RAM).
6329 * Stack space is very limited. Avoid big data buffers or things like
6332 Having only the stack as writable memory limits means we cannot use
6333 normal global data to share information between the code. But it
6334 turned out that the implementation of U-Boot can be greatly
6335 simplified by making a global data structure (gd_t) available to all
6336 functions. We could pass a pointer to this data as argument to _all_
6337 functions, but this would bloat the code. Instead we use a feature of
6338 the GCC compiler (Global Register Variables) to share the data: we
6339 place a pointer (gd) to the global data into a register which we
6340 reserve for this purpose.
6342 When choosing a register for such a purpose we are restricted by the
6343 relevant (E)ABI specifications for the current architecture, and by
6344 GCC's implementation.
6346 For PowerPC, the following registers have specific use:
6348 R2: reserved for system use
6349 R3-R4: parameter passing and return values
6350 R5-R10: parameter passing
6351 R13: small data area pointer
6355 (U-Boot also uses R12 as internal GOT pointer. r12
6356 is a volatile register so r12 needs to be reset when
6357 going back and forth between asm and C)
6359 ==> U-Boot will use R2 to hold a pointer to the global data
6361 Note: on PPC, we could use a static initializer (since the
6362 address of the global data structure is known at compile time),
6363 but it turned out that reserving a register results in somewhat
6364 smaller code - although the code savings are not that big (on
6365 average for all boards 752 bytes for the whole U-Boot image,
6366 624 text + 127 data).
6368 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6369 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6371 ==> U-Boot will use P3 to hold a pointer to the global data
6373 On ARM, the following registers are used:
6375 R0: function argument word/integer result
6376 R1-R3: function argument word
6377 R9: platform specific
6378 R10: stack limit (used only if stack checking is enabled)
6379 R11: argument (frame) pointer
6380 R12: temporary workspace
6383 R15: program counter
6385 ==> U-Boot will use R9 to hold a pointer to the global data
6387 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6389 On Nios II, the ABI is documented here:
6390 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6392 ==> U-Boot will use gp to hold a pointer to the global data
6394 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6395 to access small data sections, so gp is free.
6397 On NDS32, the following registers are used:
6399 R0-R1: argument/return
6401 R15: temporary register for assembler
6402 R16: trampoline register
6403 R28: frame pointer (FP)
6404 R29: global pointer (GP)
6405 R30: link register (LP)
6406 R31: stack pointer (SP)
6407 PC: program counter (PC)
6409 ==> U-Boot will use R10 to hold a pointer to the global data
6411 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6412 or current versions of GCC may "optimize" the code too much.
6417 U-Boot runs in system state and uses physical addresses, i.e. the
6418 MMU is not used either for address mapping nor for memory protection.
6420 The available memory is mapped to fixed addresses using the memory
6421 controller. In this process, a contiguous block is formed for each
6422 memory type (Flash, SDRAM, SRAM), even when it consists of several
6423 physical memory banks.
6425 U-Boot is installed in the first 128 kB of the first Flash bank (on
6426 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6427 booting and sizing and initializing DRAM, the code relocates itself
6428 to the upper end of DRAM. Immediately below the U-Boot code some
6429 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6430 configuration setting]. Below that, a structure with global Board
6431 Info data is placed, followed by the stack (growing downward).
6433 Additionally, some exception handler code is copied to the low 8 kB
6434 of DRAM (0x00000000 ... 0x00001FFF).
6436 So a typical memory configuration with 16 MB of DRAM could look like
6439 0x0000 0000 Exception Vector code
6442 0x0000 2000 Free for Application Use
6448 0x00FB FF20 Monitor Stack (Growing downward)
6449 0x00FB FFAC Board Info Data and permanent copy of global data
6450 0x00FC 0000 Malloc Arena
6453 0x00FE 0000 RAM Copy of Monitor Code
6454 ... eventually: LCD or video framebuffer
6455 ... eventually: pRAM (Protected RAM - unchanged by reset)
6456 0x00FF FFFF [End of RAM]
6459 System Initialization:
6460 ----------------------
6462 In the reset configuration, U-Boot starts at the reset entry point
6463 (on most PowerPC systems at address 0x00000100). Because of the reset
6464 configuration for CS0# this is a mirror of the on board Flash memory.
6465 To be able to re-map memory U-Boot then jumps to its link address.
6466 To be able to implement the initialization code in C, a (small!)
6467 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6468 which provide such a feature like MPC8xx or MPC8260), or in a locked
6469 part of the data cache. After that, U-Boot initializes the CPU core,
6470 the caches and the SIU.
6472 Next, all (potentially) available memory banks are mapped using a
6473 preliminary mapping. For example, we put them on 512 MB boundaries
6474 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6475 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6476 programmed for SDRAM access. Using the temporary configuration, a
6477 simple memory test is run that determines the size of the SDRAM
6480 When there is more than one SDRAM bank, and the banks are of
6481 different size, the largest is mapped first. For equal size, the first
6482 bank (CS2#) is mapped first. The first mapping is always for address
6483 0x00000000, with any additional banks following immediately to create
6484 contiguous memory starting from 0.
6486 Then, the monitor installs itself at the upper end of the SDRAM area
6487 and allocates memory for use by malloc() and for the global Board
6488 Info data; also, the exception vector code is copied to the low RAM
6489 pages, and the final stack is set up.
6491 Only after this relocation will you have a "normal" C environment;
6492 until that you are restricted in several ways, mostly because you are
6493 running from ROM, and because the code will have to be relocated to a
6497 U-Boot Porting Guide:
6498 ----------------------
6500 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6504 int main(int argc, char *argv[])
6506 sighandler_t no_more_time;
6508 signal(SIGALRM, no_more_time);
6509 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6511 if (available_money > available_manpower) {
6512 Pay consultant to port U-Boot;
6516 Download latest U-Boot source;
6518 Subscribe to u-boot mailing list;
6521 email("Hi, I am new to U-Boot, how do I get started?");
6524 Read the README file in the top level directory;
6525 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6526 Read applicable doc/*.README;
6527 Read the source, Luke;
6528 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6531 if (available_money > toLocalCurrency ($2500))
6534 Add a lot of aggravation and time;
6536 if (a similar board exists) { /* hopefully... */
6537 cp -a board/<similar> board/<myboard>
6538 cp include/configs/<similar>.h include/configs/<myboard>.h
6540 Create your own board support subdirectory;
6541 Create your own board include/configs/<myboard>.h file;
6543 Edit new board/<myboard> files
6544 Edit new include/configs/<myboard>.h
6549 Add / modify source code;
6553 email("Hi, I am having problems...");
6555 Send patch file to the U-Boot email list;
6556 if (reasonable critiques)
6557 Incorporate improvements from email list code review;
6559 Defend code as written;
6565 void no_more_time (int sig)
6574 All contributions to U-Boot should conform to the Linux kernel
6575 coding style; see the file "Documentation/CodingStyle" and the script
6576 "scripts/Lindent" in your Linux kernel source directory.
6578 Source files originating from a different project (for example the
6579 MTD subsystem) are generally exempt from these guidelines and are not
6580 reformatted to ease subsequent migration to newer versions of those
6583 Please note that U-Boot is implemented in C (and to some small parts in
6584 Assembler); no C++ is used, so please do not use C++ style comments (//)
6587 Please also stick to the following formatting rules:
6588 - remove any trailing white space
6589 - use TAB characters for indentation and vertical alignment, not spaces
6590 - make sure NOT to use DOS '\r\n' line feeds
6591 - do not add more than 2 consecutive empty lines to source files
6592 - do not add trailing empty lines to source files
6594 Submissions which do not conform to the standards may be returned
6595 with a request to reformat the changes.
6601 Since the number of patches for U-Boot is growing, we need to
6602 establish some rules. Submissions which do not conform to these rules
6603 may be rejected, even when they contain important and valuable stuff.
6605 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6607 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6608 see http://lists.denx.de/mailman/listinfo/u-boot
6610 When you send a patch, please include the following information with
6613 * For bug fixes: a description of the bug and how your patch fixes
6614 this bug. Please try to include a way of demonstrating that the
6615 patch actually fixes something.
6617 * For new features: a description of the feature and your
6620 * A CHANGELOG entry as plaintext (separate from the patch)
6622 * For major contributions, your entry to the CREDITS file
6624 * When you add support for a new board, don't forget to add a
6625 maintainer e-mail address to the boards.cfg file, too.
6627 * If your patch adds new configuration options, don't forget to
6628 document these in the README file.
6630 * The patch itself. If you are using git (which is *strongly*
6631 recommended) you can easily generate the patch using the
6632 "git format-patch". If you then use "git send-email" to send it to
6633 the U-Boot mailing list, you will avoid most of the common problems
6634 with some other mail clients.
6636 If you cannot use git, use "diff -purN OLD NEW". If your version of
6637 diff does not support these options, then get the latest version of
6640 The current directory when running this command shall be the parent
6641 directory of the U-Boot source tree (i. e. please make sure that
6642 your patch includes sufficient directory information for the
6645 We prefer patches as plain text. MIME attachments are discouraged,
6646 and compressed attachments must not be used.
6648 * If one logical set of modifications affects or creates several
6649 files, all these changes shall be submitted in a SINGLE patch file.
6651 * Changesets that contain different, unrelated modifications shall be
6652 submitted as SEPARATE patches, one patch per changeset.
6657 * Before sending the patch, run the MAKEALL script on your patched
6658 source tree and make sure that no errors or warnings are reported
6659 for any of the boards.
6661 * Keep your modifications to the necessary minimum: A patch
6662 containing several unrelated changes or arbitrary reformats will be
6663 returned with a request to re-formatting / split it.
6665 * If you modify existing code, make sure that your new code does not
6666 add to the memory footprint of the code ;-) Small is beautiful!
6667 When adding new features, these should compile conditionally only
6668 (using #ifdef), and the resulting code with the new feature
6669 disabled must not need more memory than the old code without your
6672 * Remember that there is a size limit of 100 kB per message on the
6673 u-boot mailing list. Bigger patches will be moderated. If they are
6674 reasonable and not too big, they will be acknowledged. But patches
6675 bigger than the size limit should be avoided.
projects / oweals / u-boot.git / blob