2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_430973
705 CONFIG_ARM_ERRATA_454179
706 CONFIG_ARM_ERRATA_621766
707 CONFIG_ARM_ERRATA_798870
710 CONFIG_TEGRA_SUPPORT_NON_SECURE
712 Support executing U-Boot in non-secure (NS) mode. Certain
713 impossible actions will be skipped if the CPU is in NS mode,
714 such as ARM architectural timer initialization.
716 - Linux Kernel Interface:
719 U-Boot stores all clock information in Hz
720 internally. For binary compatibility with older Linux
721 kernels (which expect the clocks passed in the
722 bd_info data to be in MHz) the environment variable
723 "clocks_in_mhz" can be defined so that U-Boot
724 converts clock data to MHZ before passing it to the
726 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
727 "clocks_in_mhz=1" is automatically included in the
730 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
732 When transferring memsize parameter to Linux, some versions
733 expect it to be in bytes, others in MB.
734 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
738 New kernel versions are expecting firmware settings to be
739 passed using flattened device trees (based on open firmware
743 * New libfdt-based support
744 * Adds the "fdt" command
745 * The bootm command automatically updates the fdt
747 OF_CPU - The proper name of the cpus node (only required for
748 MPC512X and MPC5xxx based boards).
749 OF_SOC - The proper name of the soc node (only required for
750 MPC512X and MPC5xxx based boards).
751 OF_TBCLK - The timebase frequency.
752 OF_STDOUT_PATH - The path to the console device
754 boards with QUICC Engines require OF_QE to set UCC MAC
757 CONFIG_OF_BOARD_SETUP
759 Board code has addition modification that it wants to make
760 to the flat device tree before handing it off to the kernel
762 CONFIG_OF_SYSTEM_SETUP
764 Other code has addition modification that it wants to make
765 to the flat device tree before handing it off to the kernel.
766 This causes ft_system_setup() to be called before booting
771 This define fills in the correct boot CPU in the boot
772 param header, the default value is zero if undefined.
776 U-Boot can detect if an IDE device is present or not.
777 If not, and this new config option is activated, U-Boot
778 removes the ATA node from the DTS before booting Linux,
779 so the Linux IDE driver does not probe the device and
780 crash. This is needed for buggy hardware (uc101) where
781 no pull down resistor is connected to the signal IDE5V_DD7.
783 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
785 This setting is mandatory for all boards that have only one
786 machine type and must be used to specify the machine type
787 number as it appears in the ARM machine registry
788 (see http://www.arm.linux.org.uk/developer/machines/).
789 Only boards that have multiple machine types supported
790 in a single configuration file and the machine type is
791 runtime discoverable, do not have to use this setting.
793 - vxWorks boot parameters:
795 bootvx constructs a valid bootline using the following
796 environments variables: bootfile, ipaddr, serverip, hostname.
797 It loads the vxWorks image pointed bootfile.
799 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
800 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
801 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
802 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
804 CONFIG_SYS_VXWORKS_ADD_PARAMS
806 Add it at the end of the bootline. E.g "u=username pw=secret"
808 Note: If a "bootargs" environment is defined, it will overwride
809 the defaults discussed just above.
811 - Cache Configuration:
812 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
813 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
814 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
816 - Cache Configuration for ARM:
817 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
819 CONFIG_SYS_PL310_BASE - Physical base address of PL310
820 controller register space
825 Define this if you want support for Amba PrimeCell PL010 UARTs.
829 Define this if you want support for Amba PrimeCell PL011 UARTs.
833 If you have Amba PrimeCell PL011 UARTs, set this variable to
834 the clock speed of the UARTs.
838 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
839 define this to a list of base addresses for each (supported)
840 port. See e.g. include/configs/versatile.h
842 CONFIG_PL011_SERIAL_RLCR
844 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
845 have separate receive and transmit line control registers. Set
846 this variable to initialize the extra register.
848 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
850 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
851 boot loader that has already initialized the UART. Define this
852 variable to flush the UART at init time.
854 CONFIG_SERIAL_HW_FLOW_CONTROL
856 Define this variable to enable hw flow control in serial driver.
857 Current user of this option is drivers/serial/nsl16550.c driver
860 Depending on board, define exactly one serial port
861 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
862 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
863 console by defining CONFIG_8xx_CONS_NONE
865 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
866 port routines must be defined elsewhere
867 (i.e. serial_init(), serial_getc(), ...)
870 Enables console device for a color framebuffer. Needs following
871 defines (cf. smiLynxEM, i8042)
872 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
874 VIDEO_HW_RECTFILL graphic chip supports
877 VIDEO_HW_BITBLT graphic chip supports
878 bit-blit (cf. smiLynxEM)
879 VIDEO_VISIBLE_COLS visible pixel columns
881 VIDEO_VISIBLE_ROWS visible pixel rows
882 VIDEO_PIXEL_SIZE bytes per pixel
883 VIDEO_DATA_FORMAT graphic data format
884 (0-5, cf. cfb_console.c)
885 VIDEO_FB_ADRS framebuffer address
886 VIDEO_KBD_INIT_FCT keyboard int fct
887 (i.e. i8042_kbd_init())
888 VIDEO_TSTC_FCT test char fct
890 VIDEO_GETC_FCT get char fct
892 CONFIG_CONSOLE_CURSOR cursor drawing on/off
893 (requires blink timer
895 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
896 CONFIG_CONSOLE_TIME display time/date info in
898 (requires CONFIG_CMD_DATE)
899 CONFIG_VIDEO_LOGO display Linux logo in
901 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
902 linux_logo.h for logo.
903 Requires CONFIG_VIDEO_LOGO
904 CONFIG_CONSOLE_EXTRA_INFO
905 additional board info beside
908 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
909 a limited number of ANSI escape sequences (cursor control,
910 erase functions and limited graphics rendition control).
912 When CONFIG_CFB_CONSOLE is defined, video console is
913 default i/o. Serial console can be forced with
914 environment 'console=serial'.
916 When CONFIG_SILENT_CONSOLE is defined, all console
917 messages (by U-Boot and Linux!) can be silenced with
918 the "silent" environment variable. See
919 doc/README.silent for more information.
921 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
923 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
927 CONFIG_BAUDRATE - in bps
928 Select one of the baudrates listed in
929 CONFIG_SYS_BAUDRATE_TABLE, see below.
930 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
932 - Console Rx buffer length
933 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
934 the maximum receive buffer length for the SMC.
935 This option is actual only for 82xx and 8xx possible.
936 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
937 must be defined, to setup the maximum idle timeout for
940 - Pre-Console Buffer:
941 Prior to the console being initialised (i.e. serial UART
942 initialised etc) all console output is silently discarded.
943 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
944 buffer any console messages prior to the console being
945 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
946 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
947 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
948 bytes are output before the console is initialised, the
949 earlier bytes are discarded.
951 'Sane' compilers will generate smaller code if
952 CONFIG_PRE_CON_BUF_SZ is a power of 2
954 - Safe printf() functions
955 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
956 the printf() functions. These are defined in
957 include/vsprintf.h and include snprintf(), vsnprintf() and
958 so on. Code size increase is approximately 300-500 bytes.
959 If this option is not given then these functions will
960 silently discard their buffer size argument - this means
961 you are not getting any overflow checking in this case.
963 - Boot Delay: CONFIG_BOOTDELAY - in seconds
964 Delay before automatically booting the default image;
965 set to -1 to disable autoboot.
966 set to -2 to autoboot with no delay and not check for abort
967 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
969 See doc/README.autoboot for these options that
970 work with CONFIG_BOOTDELAY. None are required.
971 CONFIG_BOOT_RETRY_TIME
972 CONFIG_BOOT_RETRY_MIN
973 CONFIG_AUTOBOOT_KEYED
974 CONFIG_AUTOBOOT_PROMPT
975 CONFIG_AUTOBOOT_DELAY_STR
976 CONFIG_AUTOBOOT_STOP_STR
977 CONFIG_AUTOBOOT_DELAY_STR2
978 CONFIG_AUTOBOOT_STOP_STR2
979 CONFIG_ZERO_BOOTDELAY_CHECK
980 CONFIG_RESET_TO_RETRY
984 Only needed when CONFIG_BOOTDELAY is enabled;
985 define a command string that is automatically executed
986 when no character is read on the console interface
987 within "Boot Delay" after reset.
990 This can be used to pass arguments to the bootm
991 command. The value of CONFIG_BOOTARGS goes into the
992 environment value "bootargs".
994 CONFIG_RAMBOOT and CONFIG_NFSBOOT
995 The value of these goes into the environment as
996 "ramboot" and "nfsboot" respectively, and can be used
997 as a convenience, when switching between booting from
1001 CONFIG_BOOTCOUNT_LIMIT
1002 Implements a mechanism for detecting a repeating reboot
1004 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1006 CONFIG_BOOTCOUNT_ENV
1007 If no softreset save registers are found on the hardware
1008 "bootcount" is stored in the environment. To prevent a
1009 saveenv on all reboots, the environment variable
1010 "upgrade_available" is used. If "upgrade_available" is
1011 0, "bootcount" is always 0, if "upgrade_available" is
1012 1 "bootcount" is incremented in the environment.
1013 So the Userspace Applikation must set the "upgrade_available"
1014 and "bootcount" variable to 0, if a boot was successfully.
1016 - Pre-Boot Commands:
1019 When this option is #defined, the existence of the
1020 environment variable "preboot" will be checked
1021 immediately before starting the CONFIG_BOOTDELAY
1022 countdown and/or running the auto-boot command resp.
1023 entering interactive mode.
1025 This feature is especially useful when "preboot" is
1026 automatically generated or modified. For an example
1027 see the LWMON board specific code: here "preboot" is
1028 modified when the user holds down a certain
1029 combination of keys on the (special) keyboard when
1032 - Serial Download Echo Mode:
1034 If defined to 1, all characters received during a
1035 serial download (using the "loads" command) are
1036 echoed back. This might be needed by some terminal
1037 emulations (like "cu"), but may as well just take
1038 time on others. This setting #define's the initial
1039 value of the "loads_echo" environment variable.
1041 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1042 CONFIG_KGDB_BAUDRATE
1043 Select one of the baudrates listed in
1044 CONFIG_SYS_BAUDRATE_TABLE, see below.
1046 - Monitor Functions:
1047 Monitor commands can be included or excluded
1048 from the build by using the #include files
1049 <config_cmd_all.h> and #undef'ing unwanted
1050 commands, or using <config_cmd_default.h>
1051 and augmenting with additional #define's
1052 for wanted commands.
1054 The default command configuration includes all commands
1055 except those marked below with a "*".
1057 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1058 CONFIG_CMD_ASKENV * ask for env variable
1059 CONFIG_CMD_BDI bdinfo
1060 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1061 CONFIG_CMD_BMP * BMP support
1062 CONFIG_CMD_BSP * Board specific commands
1063 CONFIG_CMD_BOOTD bootd
1064 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1065 CONFIG_CMD_CACHE * icache, dcache
1066 CONFIG_CMD_CLK * clock command support
1067 CONFIG_CMD_CONSOLE coninfo
1068 CONFIG_CMD_CRC32 * crc32
1069 CONFIG_CMD_DATE * support for RTC, date/time...
1070 CONFIG_CMD_DHCP * DHCP support
1071 CONFIG_CMD_DIAG * Diagnostics
1072 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1073 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1074 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1075 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1076 CONFIG_CMD_DTT * Digital Therm and Thermostat
1077 CONFIG_CMD_ECHO echo arguments
1078 CONFIG_CMD_EDITENV edit env variable
1079 CONFIG_CMD_EEPROM * EEPROM read/write support
1080 CONFIG_CMD_ELF * bootelf, bootvx
1081 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1082 CONFIG_CMD_ENV_FLAGS * display details about env flags
1083 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1084 CONFIG_CMD_EXPORTENV * export the environment
1085 CONFIG_CMD_EXT2 * ext2 command support
1086 CONFIG_CMD_EXT4 * ext4 command support
1087 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1088 that work for multiple fs types
1089 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1090 CONFIG_CMD_SAVEENV saveenv
1091 CONFIG_CMD_FDC * Floppy Disk Support
1092 CONFIG_CMD_FAT * FAT command support
1093 CONFIG_CMD_FLASH flinfo, erase, protect
1094 CONFIG_CMD_FPGA FPGA device initialization support
1095 CONFIG_CMD_FUSE * Device fuse support
1096 CONFIG_CMD_GETTIME * Get time since boot
1097 CONFIG_CMD_GO * the 'go' command (exec code)
1098 CONFIG_CMD_GREPENV * search environment
1099 CONFIG_CMD_HASH * calculate hash / digest
1100 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1101 CONFIG_CMD_I2C * I2C serial bus support
1102 CONFIG_CMD_IDE * IDE harddisk support
1103 CONFIG_CMD_IMI iminfo
1104 CONFIG_CMD_IMLS List all images found in NOR flash
1105 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1106 CONFIG_CMD_IMMAP * IMMR dump support
1107 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1108 CONFIG_CMD_IMPORTENV * import an environment
1109 CONFIG_CMD_INI * import data from an ini file into the env
1110 CONFIG_CMD_IRQ * irqinfo
1111 CONFIG_CMD_ITEST Integer/string test of 2 values
1112 CONFIG_CMD_JFFS2 * JFFS2 Support
1113 CONFIG_CMD_KGDB * kgdb
1114 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1115 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1117 CONFIG_CMD_LOADB loadb
1118 CONFIG_CMD_LOADS loads
1119 CONFIG_CMD_MD5SUM * print md5 message digest
1120 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1121 CONFIG_CMD_MEMINFO * Display detailed memory information
1122 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1124 CONFIG_CMD_MEMTEST * mtest
1125 CONFIG_CMD_MISC Misc functions like sleep etc
1126 CONFIG_CMD_MMC * MMC memory mapped support
1127 CONFIG_CMD_MII * MII utility commands
1128 CONFIG_CMD_MTDPARTS * MTD partition support
1129 CONFIG_CMD_NAND * NAND support
1130 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1131 CONFIG_CMD_NFS NFS support
1132 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1133 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1134 CONFIG_CMD_PCI * pciinfo
1135 CONFIG_CMD_PCMCIA * PCMCIA support
1136 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1138 CONFIG_CMD_PORTIO * Port I/O
1139 CONFIG_CMD_READ * Read raw data from partition
1140 CONFIG_CMD_REGINFO * Register dump
1141 CONFIG_CMD_RUN run command in env variable
1142 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1143 CONFIG_CMD_SAVES * save S record dump
1144 CONFIG_CMD_SCSI * SCSI Support
1145 CONFIG_CMD_SDRAM * print SDRAM configuration information
1146 (requires CONFIG_CMD_I2C)
1147 CONFIG_CMD_SETGETDCR Support for DCR Register access
1149 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1150 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1151 (requires CONFIG_CMD_MEMORY)
1152 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1153 CONFIG_CMD_SOURCE "source" command Support
1154 CONFIG_CMD_SPI * SPI serial bus support
1155 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1156 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1157 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1158 CONFIG_CMD_TIMER * access to the system tick timer
1159 CONFIG_CMD_USB * USB support
1160 CONFIG_CMD_CDP * Cisco Discover Protocol support
1161 CONFIG_CMD_MFSL * Microblaze FSL support
1162 CONFIG_CMD_XIMG Load part of Multi Image
1163 CONFIG_CMD_UUID * Generate random UUID or GUID string
1165 EXAMPLE: If you want all functions except of network
1166 support you can write:
1168 #include "config_cmd_all.h"
1169 #undef CONFIG_CMD_NET
1172 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1174 Note: Don't enable the "icache" and "dcache" commands
1175 (configuration option CONFIG_CMD_CACHE) unless you know
1176 what you (and your U-Boot users) are doing. Data
1177 cache cannot be enabled on systems like the 8xx or
1178 8260 (where accesses to the IMMR region must be
1179 uncached), and it cannot be disabled on all other
1180 systems where we (mis-) use the data cache to hold an
1181 initial stack and some data.
1184 XXX - this list needs to get updated!
1186 - Regular expression support:
1188 If this variable is defined, U-Boot is linked against
1189 the SLRE (Super Light Regular Expression) library,
1190 which adds regex support to some commands, as for
1191 example "env grep" and "setexpr".
1195 If this variable is defined, U-Boot will use a device tree
1196 to configure its devices, instead of relying on statically
1197 compiled #defines in the board file. This option is
1198 experimental and only available on a few boards. The device
1199 tree is available in the global data as gd->fdt_blob.
1201 U-Boot needs to get its device tree from somewhere. This can
1202 be done using one of the two options below:
1205 If this variable is defined, U-Boot will embed a device tree
1206 binary in its image. This device tree file should be in the
1207 board directory and called <soc>-<board>.dts. The binary file
1208 is then picked up in board_init_f() and made available through
1209 the global data structure as gd->blob.
1212 If this variable is defined, U-Boot will build a device tree
1213 binary. It will be called u-boot.dtb. Architecture-specific
1214 code will locate it at run-time. Generally this works by:
1216 cat u-boot.bin u-boot.dtb >image.bin
1218 and in fact, U-Boot does this for you, creating a file called
1219 u-boot-dtb.bin which is useful in the common case. You can
1220 still use the individual files if you need something more
1225 If this variable is defined, it enables watchdog
1226 support for the SoC. There must be support in the SoC
1227 specific code for a watchdog. For the 8xx and 8260
1228 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1229 register. When supported for a specific SoC is
1230 available, then no further board specific code should
1231 be needed to use it.
1234 When using a watchdog circuitry external to the used
1235 SoC, then define this variable and provide board
1236 specific code for the "hw_watchdog_reset" function.
1238 CONFIG_AT91_HW_WDT_TIMEOUT
1239 specify the timeout in seconds. default 2 seconds.
1242 CONFIG_VERSION_VARIABLE
1243 If this variable is defined, an environment variable
1244 named "ver" is created by U-Boot showing the U-Boot
1245 version as printed by the "version" command.
1246 Any change to this variable will be reverted at the
1251 When CONFIG_CMD_DATE is selected, the type of the RTC
1252 has to be selected, too. Define exactly one of the
1255 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1256 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1257 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1258 CONFIG_RTC_MC146818 - use MC146818 RTC
1259 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1260 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1261 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1262 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1263 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1264 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1265 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1266 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1267 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1270 Note that if the RTC uses I2C, then the I2C interface
1271 must also be configured. See I2C Support, below.
1274 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1276 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1277 chip-ngpio pairs that tell the PCA953X driver the number of
1278 pins supported by a particular chip.
1280 Note that if the GPIO device uses I2C, then the I2C interface
1281 must also be configured. See I2C Support, below.
1284 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1285 accesses and can checksum them or write a list of them out
1286 to memory. See the 'iotrace' command for details. This is
1287 useful for testing device drivers since it can confirm that
1288 the driver behaves the same way before and after a code
1289 change. Currently this is supported on sandbox and arm. To
1290 add support for your architecture, add '#include <iotrace.h>'
1291 to the bottom of arch/<arch>/include/asm/io.h and test.
1293 Example output from the 'iotrace stats' command is below.
1294 Note that if the trace buffer is exhausted, the checksum will
1295 still continue to operate.
1298 Start: 10000000 (buffer start address)
1299 Size: 00010000 (buffer size)
1300 Offset: 00000120 (current buffer offset)
1301 Output: 10000120 (start + offset)
1302 Count: 00000018 (number of trace records)
1303 CRC32: 9526fb66 (CRC32 of all trace records)
1305 - Timestamp Support:
1307 When CONFIG_TIMESTAMP is selected, the timestamp
1308 (date and time) of an image is printed by image
1309 commands like bootm or iminfo. This option is
1310 automatically enabled when you select CONFIG_CMD_DATE .
1312 - Partition Labels (disklabels) Supported:
1313 Zero or more of the following:
1314 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1315 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1316 Intel architecture, USB sticks, etc.
1317 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1318 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1319 bootloader. Note 2TB partition limit; see
1321 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1323 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1324 CONFIG_CMD_SCSI) you must configure support for at
1325 least one non-MTD partition type as well.
1328 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1329 board configurations files but used nowhere!
1331 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1332 be performed by calling the function
1333 ide_set_reset(int reset)
1334 which has to be defined in a board specific file
1339 Set this to enable ATAPI support.
1344 Set this to enable support for disks larger than 137GB
1345 Also look at CONFIG_SYS_64BIT_LBA.
1346 Whithout these , LBA48 support uses 32bit variables and will 'only'
1347 support disks up to 2.1TB.
1349 CONFIG_SYS_64BIT_LBA:
1350 When enabled, makes the IDE subsystem use 64bit sector addresses.
1354 At the moment only there is only support for the
1355 SYM53C8XX SCSI controller; define
1356 CONFIG_SCSI_SYM53C8XX to enable it.
1358 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1359 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1360 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1361 maximum numbers of LUNs, SCSI ID's and target
1363 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1365 The environment variable 'scsidevs' is set to the number of
1366 SCSI devices found during the last scan.
1368 - NETWORK Support (PCI):
1370 Support for Intel 8254x/8257x gigabit chips.
1373 Utility code for direct access to the SPI bus on Intel 8257x.
1374 This does not do anything useful unless you set at least one
1375 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1377 CONFIG_E1000_SPI_GENERIC
1378 Allow generic access to the SPI bus on the Intel 8257x, for
1379 example with the "sspi" command.
1382 Management command for E1000 devices. When used on devices
1383 with SPI support you can reprogram the EEPROM from U-Boot.
1385 CONFIG_E1000_FALLBACK_MAC
1386 default MAC for empty EEPROM after production.
1389 Support for Intel 82557/82559/82559ER chips.
1390 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1391 write routine for first time initialisation.
1394 Support for Digital 2114x chips.
1395 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1396 modem chip initialisation (KS8761/QS6611).
1399 Support for National dp83815 chips.
1402 Support for National dp8382[01] gigabit chips.
1404 - NETWORK Support (other):
1406 CONFIG_DRIVER_AT91EMAC
1407 Support for AT91RM9200 EMAC.
1410 Define this to use reduced MII inteface
1412 CONFIG_DRIVER_AT91EMAC_QUIET
1413 If this defined, the driver is quiet.
1414 The driver doen't show link status messages.
1416 CONFIG_CALXEDA_XGMAC
1417 Support for the Calxeda XGMAC device
1420 Support for SMSC's LAN91C96 chips.
1422 CONFIG_LAN91C96_BASE
1423 Define this to hold the physical address
1424 of the LAN91C96's I/O space
1426 CONFIG_LAN91C96_USE_32_BIT
1427 Define this to enable 32 bit addressing
1430 Support for SMSC's LAN91C111 chip
1432 CONFIG_SMC91111_BASE
1433 Define this to hold the physical address
1434 of the device (I/O space)
1436 CONFIG_SMC_USE_32_BIT
1437 Define this if data bus is 32 bits
1439 CONFIG_SMC_USE_IOFUNCS
1440 Define this to use i/o functions instead of macros
1441 (some hardware wont work with macros)
1443 CONFIG_DRIVER_TI_EMAC
1444 Support for davinci emac
1446 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1447 Define this if you have more then 3 PHYs.
1450 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1452 CONFIG_FTGMAC100_EGIGA
1453 Define this to use GE link update with gigabit PHY.
1454 Define this if FTGMAC100 is connected to gigabit PHY.
1455 If your system has 10/100 PHY only, it might not occur
1456 wrong behavior. Because PHY usually return timeout or
1457 useless data when polling gigabit status and gigabit
1458 control registers. This behavior won't affect the
1459 correctnessof 10/100 link speed update.
1462 Support for SMSC's LAN911x and LAN921x chips
1465 Define this to hold the physical address
1466 of the device (I/O space)
1468 CONFIG_SMC911X_32_BIT
1469 Define this if data bus is 32 bits
1471 CONFIG_SMC911X_16_BIT
1472 Define this if data bus is 16 bits. If your processor
1473 automatically converts one 32 bit word to two 16 bit
1474 words you may also try CONFIG_SMC911X_32_BIT.
1477 Support for Renesas on-chip Ethernet controller
1479 CONFIG_SH_ETHER_USE_PORT
1480 Define the number of ports to be used
1482 CONFIG_SH_ETHER_PHY_ADDR
1483 Define the ETH PHY's address
1485 CONFIG_SH_ETHER_CACHE_WRITEBACK
1486 If this option is set, the driver enables cache flush.
1490 Support for PWM modul on the imx6.
1494 Support TPM devices.
1497 Support for i2c bus TPM devices. Only one device
1498 per system is supported at this time.
1500 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1501 Define the the i2c bus number for the TPM device
1503 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1504 Define the TPM's address on the i2c bus
1506 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1507 Define the burst count bytes upper limit
1509 CONFIG_TPM_ATMEL_TWI
1510 Support for Atmel TWI TPM device. Requires I2C support.
1513 Support for generic parallel port TPM devices. Only one device
1514 per system is supported at this time.
1516 CONFIG_TPM_TIS_BASE_ADDRESS
1517 Base address where the generic TPM device is mapped
1518 to. Contemporary x86 systems usually map it at
1522 Add tpm monitor functions.
1523 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1524 provides monitor access to authorized functions.
1527 Define this to enable the TPM support library which provides
1528 functional interfaces to some TPM commands.
1529 Requires support for a TPM device.
1531 CONFIG_TPM_AUTH_SESSIONS
1532 Define this to enable authorized functions in the TPM library.
1533 Requires CONFIG_TPM and CONFIG_SHA1.
1536 At the moment only the UHCI host controller is
1537 supported (PIP405, MIP405, MPC5200); define
1538 CONFIG_USB_UHCI to enable it.
1539 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1540 and define CONFIG_USB_STORAGE to enable the USB
1543 Supported are USB Keyboards and USB Floppy drives
1545 MPC5200 USB requires additional defines:
1547 for 528 MHz Clock: 0x0001bbbb
1551 for differential drivers: 0x00001000
1552 for single ended drivers: 0x00005000
1553 for differential drivers on PSC3: 0x00000100
1554 for single ended drivers on PSC3: 0x00004100
1555 CONFIG_SYS_USB_EVENT_POLL
1556 May be defined to allow interrupt polling
1557 instead of using asynchronous interrupts
1559 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1560 txfilltuning field in the EHCI controller on reset.
1562 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1563 HW module registers.
1566 Define the below if you wish to use the USB console.
1567 Once firmware is rebuilt from a serial console issue the
1568 command "setenv stdin usbtty; setenv stdout usbtty" and
1569 attach your USB cable. The Unix command "dmesg" should print
1570 it has found a new device. The environment variable usbtty
1571 can be set to gserial or cdc_acm to enable your device to
1572 appear to a USB host as a Linux gserial device or a
1573 Common Device Class Abstract Control Model serial device.
1574 If you select usbtty = gserial you should be able to enumerate
1576 # modprobe usbserial vendor=0xVendorID product=0xProductID
1577 else if using cdc_acm, simply setting the environment
1578 variable usbtty to be cdc_acm should suffice. The following
1579 might be defined in YourBoardName.h
1582 Define this to build a UDC device
1585 Define this to have a tty type of device available to
1586 talk to the UDC device
1589 Define this to enable the high speed support for usb
1590 device and usbtty. If this feature is enabled, a routine
1591 int is_usbd_high_speed(void)
1592 also needs to be defined by the driver to dynamically poll
1593 whether the enumeration has succeded at high speed or full
1596 CONFIG_SYS_CONSOLE_IS_IN_ENV
1597 Define this if you want stdin, stdout &/or stderr to
1601 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1602 Derive USB clock from external clock "blah"
1603 - CONFIG_SYS_USB_EXTC_CLK 0x02
1605 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1606 Derive USB clock from brgclk
1607 - CONFIG_SYS_USB_BRG_CLK 0x04
1609 If you have a USB-IF assigned VendorID then you may wish to
1610 define your own vendor specific values either in BoardName.h
1611 or directly in usbd_vendor_info.h. If you don't define
1612 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1613 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1614 should pretend to be a Linux device to it's target host.
1616 CONFIG_USBD_MANUFACTURER
1617 Define this string as the name of your company for
1618 - CONFIG_USBD_MANUFACTURER "my company"
1620 CONFIG_USBD_PRODUCT_NAME
1621 Define this string as the name of your product
1622 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1624 CONFIG_USBD_VENDORID
1625 Define this as your assigned Vendor ID from the USB
1626 Implementors Forum. This *must* be a genuine Vendor ID
1627 to avoid polluting the USB namespace.
1628 - CONFIG_USBD_VENDORID 0xFFFF
1630 CONFIG_USBD_PRODUCTID
1631 Define this as the unique Product ID
1633 - CONFIG_USBD_PRODUCTID 0xFFFF
1635 - ULPI Layer Support:
1636 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1637 the generic ULPI layer. The generic layer accesses the ULPI PHY
1638 via the platform viewport, so you need both the genric layer and
1639 the viewport enabled. Currently only Chipidea/ARC based
1640 viewport is supported.
1641 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1642 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1643 If your ULPI phy needs a different reference clock than the
1644 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1645 the appropriate value in Hz.
1648 The MMC controller on the Intel PXA is supported. To
1649 enable this define CONFIG_MMC. The MMC can be
1650 accessed from the boot prompt by mapping the device
1651 to physical memory similar to flash. Command line is
1652 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1653 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1656 Support for Renesas on-chip MMCIF controller
1658 CONFIG_SH_MMCIF_ADDR
1659 Define the base address of MMCIF registers
1662 Define the clock frequency for MMCIF
1665 Enable the generic MMC driver
1667 CONFIG_SUPPORT_EMMC_BOOT
1668 Enable some additional features of the eMMC boot partitions.
1670 CONFIG_SUPPORT_EMMC_RPMB
1671 Enable the commands for reading, writing and programming the
1672 key for the Replay Protection Memory Block partition in eMMC.
1674 - USB Device Firmware Update (DFU) class support:
1676 This enables the USB portion of the DFU USB class
1679 This enables the command "dfu" which is used to have
1680 U-Boot create a DFU class device via USB. This command
1681 requires that the "dfu_alt_info" environment variable be
1682 set and define the alt settings to expose to the host.
1685 This enables support for exposing (e)MMC devices via DFU.
1688 This enables support for exposing NAND devices via DFU.
1691 This enables support for exposing RAM via DFU.
1692 Note: DFU spec refer to non-volatile memory usage, but
1693 allow usages beyond the scope of spec - here RAM usage,
1694 one that would help mostly the developer.
1696 CONFIG_SYS_DFU_DATA_BUF_SIZE
1697 Dfu transfer uses a buffer before writing data to the
1698 raw storage device. Make the size (in bytes) of this buffer
1699 configurable. The size of this buffer is also configurable
1700 through the "dfu_bufsiz" environment variable.
1702 CONFIG_SYS_DFU_MAX_FILE_SIZE
1703 When updating files rather than the raw storage device,
1704 we use a static buffer to copy the file into and then write
1705 the buffer once we've been given the whole file. Define
1706 this to the maximum filesize (in bytes) for the buffer.
1707 Default is 4 MiB if undefined.
1709 DFU_DEFAULT_POLL_TIMEOUT
1710 Poll timeout [ms], is the timeout a device can send to the
1711 host. The host must wait for this timeout before sending
1712 a subsequent DFU_GET_STATUS request to the device.
1714 DFU_MANIFEST_POLL_TIMEOUT
1715 Poll timeout [ms], which the device sends to the host when
1716 entering dfuMANIFEST state. Host waits this timeout, before
1717 sending again an USB request to the device.
1719 - USB Device Android Fastboot support:
1721 This enables the command "fastboot" which enables the Android
1722 fastboot mode for the platform's USB device. Fastboot is a USB
1723 protocol for downloading images, flashing and device control
1724 used on Android devices.
1725 See doc/README.android-fastboot for more information.
1727 CONFIG_ANDROID_BOOT_IMAGE
1728 This enables support for booting images which use the Android
1729 image format header.
1731 CONFIG_USB_FASTBOOT_BUF_ADDR
1732 The fastboot protocol requires a large memory buffer for
1733 downloads. Define this to the starting RAM address to use for
1736 CONFIG_USB_FASTBOOT_BUF_SIZE
1737 The fastboot protocol requires a large memory buffer for
1738 downloads. This buffer should be as large as possible for a
1739 platform. Define this to the size available RAM for fastboot.
1741 CONFIG_FASTBOOT_FLASH
1742 The fastboot protocol includes a "flash" command for writing
1743 the downloaded image to a non-volatile storage device. Define
1744 this to enable the "fastboot flash" command.
1746 CONFIG_FASTBOOT_FLASH_MMC_DEV
1747 The fastboot "flash" command requires additional information
1748 regarding the non-volatile storage device. Define this to
1749 the eMMC device that fastboot should use to store the image.
1751 CONFIG_FASTBOOT_GPT_NAME
1752 The fastboot "flash" command supports writing the downloaded
1753 image to the Protective MBR and the Primary GUID Partition
1754 Table. (Additionally, this downloaded image is post-processed
1755 to generate and write the Backup GUID Partition Table.)
1756 This occurs when the specified "partition name" on the
1757 "fastboot flash" command line matches this value.
1758 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1760 - Journaling Flash filesystem support:
1761 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1762 CONFIG_JFFS2_NAND_DEV
1763 Define these for a default partition on a NAND device
1765 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1766 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1767 Define these for a default partition on a NOR device
1769 CONFIG_SYS_JFFS_CUSTOM_PART
1770 Define this to create an own partition. You have to provide a
1771 function struct part_info* jffs2_part_info(int part_num)
1773 If you define only one JFFS2 partition you may also want to
1774 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1775 to disable the command chpart. This is the default when you
1776 have not defined a custom partition
1778 - FAT(File Allocation Table) filesystem write function support:
1781 Define this to enable support for saving memory data as a
1782 file in FAT formatted partition.
1784 This will also enable the command "fatwrite" enabling the
1785 user to write files to FAT.
1787 CBFS (Coreboot Filesystem) support
1790 Define this to enable support for reading from a Coreboot
1791 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1794 - FAT(File Allocation Table) filesystem cluster size:
1795 CONFIG_FS_FAT_MAX_CLUSTSIZE
1797 Define the max cluster size for fat operations else
1798 a default value of 65536 will be defined.
1803 Define this to enable standard (PC-Style) keyboard
1807 Standard PC keyboard driver with US (is default) and
1808 GERMAN key layout (switch via environment 'keymap=de') support.
1809 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1810 for cfb_console. Supports cursor blinking.
1813 Enables a Chrome OS keyboard using the CROS_EC interface.
1814 This uses CROS_EC to communicate with a second microcontroller
1815 which provides key scans on request.
1820 Define this to enable video support (for output to
1823 CONFIG_VIDEO_CT69000
1825 Enable Chips & Technologies 69000 Video chip
1827 CONFIG_VIDEO_SMI_LYNXEM
1828 Enable Silicon Motion SMI 712/710/810 Video chip. The
1829 video output is selected via environment 'videoout'
1830 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1833 For the CT69000 and SMI_LYNXEM drivers, videomode is
1834 selected via environment 'videomode'. Two different ways
1836 - "videomode=num" 'num' is a standard LiLo mode numbers.
1837 Following standard modes are supported (* is default):
1839 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1840 -------------+---------------------------------------------
1841 8 bits | 0x301* 0x303 0x305 0x161 0x307
1842 15 bits | 0x310 0x313 0x316 0x162 0x319
1843 16 bits | 0x311 0x314 0x317 0x163 0x31A
1844 24 bits | 0x312 0x315 0x318 ? 0x31B
1845 -------------+---------------------------------------------
1846 (i.e. setenv videomode 317; saveenv; reset;)
1848 - "videomode=bootargs" all the video parameters are parsed
1849 from the bootargs. (See drivers/video/videomodes.c)
1852 CONFIG_VIDEO_SED13806
1853 Enable Epson SED13806 driver. This driver supports 8bpp
1854 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1855 or CONFIG_VIDEO_SED13806_16BPP
1858 Enable the Freescale DIU video driver. Reference boards for
1859 SOCs that have a DIU should define this macro to enable DIU
1860 support, and should also define these other macros:
1866 CONFIG_VIDEO_SW_CURSOR
1867 CONFIG_VGA_AS_SINGLE_DEVICE
1869 CONFIG_VIDEO_BMP_LOGO
1871 The DIU driver will look for the 'video-mode' environment
1872 variable, and if defined, enable the DIU as a console during
1873 boot. See the documentation file README.video for a
1874 description of this variable.
1880 Define this to enable a custom keyboard support.
1881 This simply calls drv_keyboard_init() which must be
1882 defined in your board-specific files.
1883 The only board using this so far is RBC823.
1885 - LCD Support: CONFIG_LCD
1887 Define this to enable LCD support (for output to LCD
1888 display); also select one of the supported displays
1889 by defining one of these:
1893 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1895 CONFIG_NEC_NL6448AC33:
1897 NEC NL6448AC33-18. Active, color, single scan.
1899 CONFIG_NEC_NL6448BC20
1901 NEC NL6448BC20-08. 6.5", 640x480.
1902 Active, color, single scan.
1904 CONFIG_NEC_NL6448BC33_54
1906 NEC NL6448BC33-54. 10.4", 640x480.
1907 Active, color, single scan.
1911 Sharp 320x240. Active, color, single scan.
1912 It isn't 16x9, and I am not sure what it is.
1914 CONFIG_SHARP_LQ64D341
1916 Sharp LQ64D341 display, 640x480.
1917 Active, color, single scan.
1921 HLD1045 display, 640x480.
1922 Active, color, single scan.
1926 Optrex CBL50840-2 NF-FW 99 22 M5
1928 Hitachi LMG6912RPFC-00T
1932 320x240. Black & white.
1934 Normally display is black on white background; define
1935 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1937 CONFIG_LCD_ALIGNMENT
1939 Normally the LCD is page-aligned (typically 4KB). If this is
1940 defined then the LCD will be aligned to this value instead.
1941 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1942 here, since it is cheaper to change data cache settings on
1943 a per-section basis.
1945 CONFIG_CONSOLE_SCROLL_LINES
1947 When the console need to be scrolled, this is the number of
1948 lines to scroll by. It defaults to 1. Increasing this makes
1949 the console jump but can help speed up operation when scrolling
1954 Sometimes, for example if the display is mounted in portrait
1955 mode or even if it's mounted landscape but rotated by 180degree,
1956 we need to rotate our content of the display relative to the
1957 framebuffer, so that user can read the messages which are
1959 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1960 initialized with a given rotation from "vl_rot" out of
1961 "vidinfo_t" which is provided by the board specific code.
1962 The value for vl_rot is coded as following (matching to
1963 fbcon=rotate:<n> linux-kernel commandline):
1964 0 = no rotation respectively 0 degree
1965 1 = 90 degree rotation
1966 2 = 180 degree rotation
1967 3 = 270 degree rotation
1969 If CONFIG_LCD_ROTATION is not defined, the console will be
1970 initialized with 0degree rotation.
1974 Support drawing of RLE8-compressed bitmaps on the LCD.
1978 Enables an 'i2c edid' command which can read EDID
1979 information over I2C from an attached LCD display.
1981 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1983 If this option is set, the environment is checked for
1984 a variable "splashimage". If found, the usual display
1985 of logo, copyright and system information on the LCD
1986 is suppressed and the BMP image at the address
1987 specified in "splashimage" is loaded instead. The
1988 console is redirected to the "nulldev", too. This
1989 allows for a "silent" boot where a splash screen is
1990 loaded very quickly after power-on.
1992 CONFIG_SPLASHIMAGE_GUARD
1994 If this option is set, then U-Boot will prevent the environment
1995 variable "splashimage" from being set to a problematic address
1996 (see README.displaying-bmps).
1997 This option is useful for targets where, due to alignment
1998 restrictions, an improperly aligned BMP image will cause a data
1999 abort. If you think you will not have problems with unaligned
2000 accesses (for example because your toolchain prevents them)
2001 there is no need to set this option.
2003 CONFIG_SPLASH_SCREEN_ALIGN
2005 If this option is set the splash image can be freely positioned
2006 on the screen. Environment variable "splashpos" specifies the
2007 position as "x,y". If a positive number is given it is used as
2008 number of pixel from left/top. If a negative number is given it
2009 is used as number of pixel from right/bottom. You can also
2010 specify 'm' for centering the image.
2013 setenv splashpos m,m
2014 => image at center of screen
2016 setenv splashpos 30,20
2017 => image at x = 30 and y = 20
2019 setenv splashpos -10,m
2020 => vertically centered image
2021 at x = dspWidth - bmpWidth - 9
2023 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2025 If this option is set, additionally to standard BMP
2026 images, gzipped BMP images can be displayed via the
2027 splashscreen support or the bmp command.
2029 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2031 If this option is set, 8-bit RLE compressed BMP images
2032 can be displayed via the splashscreen support or the
2035 - Do compressing for memory range:
2038 If this option is set, it would use zlib deflate method
2039 to compress the specified memory at its best effort.
2041 - Compression support:
2044 Enabled by default to support gzip compressed images.
2048 If this option is set, support for bzip2 compressed
2049 images is included. If not, only uncompressed and gzip
2050 compressed images are supported.
2052 NOTE: the bzip2 algorithm requires a lot of RAM, so
2053 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2058 If this option is set, support for lzma compressed
2061 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2062 requires an amount of dynamic memory that is given by the
2065 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2067 Where lc and lp stand for, respectively, Literal context bits
2068 and Literal pos bits.
2070 This value is upper-bounded by 14MB in the worst case. Anyway,
2071 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2072 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2073 a very small buffer.
2075 Use the lzmainfo tool to determinate the lc and lp values and
2076 then calculate the amount of needed dynamic memory (ensuring
2077 the appropriate CONFIG_SYS_MALLOC_LEN value).
2081 If this option is set, support for LZO compressed images
2087 The address of PHY on MII bus.
2089 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2091 The clock frequency of the MII bus
2095 If this option is set, support for speed/duplex
2096 detection of gigabit PHY is included.
2098 CONFIG_PHY_RESET_DELAY
2100 Some PHY like Intel LXT971A need extra delay after
2101 reset before any MII register access is possible.
2102 For such PHY, set this option to the usec delay
2103 required. (minimum 300usec for LXT971A)
2105 CONFIG_PHY_CMD_DELAY (ppc4xx)
2107 Some PHY like Intel LXT971A need extra delay after
2108 command issued before MII status register can be read
2118 Define a default value for Ethernet address to use
2119 for the respective Ethernet interface, in case this
2120 is not determined automatically.
2125 Define a default value for the IP address to use for
2126 the default Ethernet interface, in case this is not
2127 determined through e.g. bootp.
2128 (Environment variable "ipaddr")
2130 - Server IP address:
2133 Defines a default value for the IP address of a TFTP
2134 server to contact when using the "tftboot" command.
2135 (Environment variable "serverip")
2137 CONFIG_KEEP_SERVERADDR
2139 Keeps the server's MAC address, in the env 'serveraddr'
2140 for passing to bootargs (like Linux's netconsole option)
2142 - Gateway IP address:
2145 Defines a default value for the IP address of the
2146 default router where packets to other networks are
2148 (Environment variable "gatewayip")
2153 Defines a default value for the subnet mask (or
2154 routing prefix) which is used to determine if an IP
2155 address belongs to the local subnet or needs to be
2156 forwarded through a router.
2157 (Environment variable "netmask")
2159 - Multicast TFTP Mode:
2162 Defines whether you want to support multicast TFTP as per
2163 rfc-2090; for example to work with atftp. Lets lots of targets
2164 tftp down the same boot image concurrently. Note: the Ethernet
2165 driver in use must provide a function: mcast() to join/leave a
2168 - BOOTP Recovery Mode:
2169 CONFIG_BOOTP_RANDOM_DELAY
2171 If you have many targets in a network that try to
2172 boot using BOOTP, you may want to avoid that all
2173 systems send out BOOTP requests at precisely the same
2174 moment (which would happen for instance at recovery
2175 from a power failure, when all systems will try to
2176 boot, thus flooding the BOOTP server. Defining
2177 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2178 inserted before sending out BOOTP requests. The
2179 following delays are inserted then:
2181 1st BOOTP request: delay 0 ... 1 sec
2182 2nd BOOTP request: delay 0 ... 2 sec
2183 3rd BOOTP request: delay 0 ... 4 sec
2185 BOOTP requests: delay 0 ... 8 sec
2187 CONFIG_BOOTP_ID_CACHE_SIZE
2189 BOOTP packets are uniquely identified using a 32-bit ID. The
2190 server will copy the ID from client requests to responses and
2191 U-Boot will use this to determine if it is the destination of
2192 an incoming response. Some servers will check that addresses
2193 aren't in use before handing them out (usually using an ARP
2194 ping) and therefore take up to a few hundred milliseconds to
2195 respond. Network congestion may also influence the time it
2196 takes for a response to make it back to the client. If that
2197 time is too long, U-Boot will retransmit requests. In order
2198 to allow earlier responses to still be accepted after these
2199 retransmissions, U-Boot's BOOTP client keeps a small cache of
2200 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2201 cache. The default is to keep IDs for up to four outstanding
2202 requests. Increasing this will allow U-Boot to accept offers
2203 from a BOOTP client in networks with unusually high latency.
2205 - DHCP Advanced Options:
2206 You can fine tune the DHCP functionality by defining
2207 CONFIG_BOOTP_* symbols:
2209 CONFIG_BOOTP_SUBNETMASK
2210 CONFIG_BOOTP_GATEWAY
2211 CONFIG_BOOTP_HOSTNAME
2212 CONFIG_BOOTP_NISDOMAIN
2213 CONFIG_BOOTP_BOOTPATH
2214 CONFIG_BOOTP_BOOTFILESIZE
2217 CONFIG_BOOTP_SEND_HOSTNAME
2218 CONFIG_BOOTP_NTPSERVER
2219 CONFIG_BOOTP_TIMEOFFSET
2220 CONFIG_BOOTP_VENDOREX
2221 CONFIG_BOOTP_MAY_FAIL
2223 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2224 environment variable, not the BOOTP server.
2226 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2227 after the configured retry count, the call will fail
2228 instead of starting over. This can be used to fail over
2229 to Link-local IP address configuration if the DHCP server
2232 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2233 serverip from a DHCP server, it is possible that more
2234 than one DNS serverip is offered to the client.
2235 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2236 serverip will be stored in the additional environment
2237 variable "dnsip2". The first DNS serverip is always
2238 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2241 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2242 to do a dynamic update of a DNS server. To do this, they
2243 need the hostname of the DHCP requester.
2244 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2245 of the "hostname" environment variable is passed as
2246 option 12 to the DHCP server.
2248 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2250 A 32bit value in microseconds for a delay between
2251 receiving a "DHCP Offer" and sending the "DHCP Request".
2252 This fixes a problem with certain DHCP servers that don't
2253 respond 100% of the time to a "DHCP request". E.g. On an
2254 AT91RM9200 processor running at 180MHz, this delay needed
2255 to be *at least* 15,000 usec before a Windows Server 2003
2256 DHCP server would reply 100% of the time. I recommend at
2257 least 50,000 usec to be safe. The alternative is to hope
2258 that one of the retries will be successful but note that
2259 the DHCP timeout and retry process takes a longer than
2262 - Link-local IP address negotiation:
2263 Negotiate with other link-local clients on the local network
2264 for an address that doesn't require explicit configuration.
2265 This is especially useful if a DHCP server cannot be guaranteed
2266 to exist in all environments that the device must operate.
2268 See doc/README.link-local for more information.
2271 CONFIG_CDP_DEVICE_ID
2273 The device id used in CDP trigger frames.
2275 CONFIG_CDP_DEVICE_ID_PREFIX
2277 A two character string which is prefixed to the MAC address
2282 A printf format string which contains the ascii name of
2283 the port. Normally is set to "eth%d" which sets
2284 eth0 for the first Ethernet, eth1 for the second etc.
2286 CONFIG_CDP_CAPABILITIES
2288 A 32bit integer which indicates the device capabilities;
2289 0x00000010 for a normal host which does not forwards.
2293 An ascii string containing the version of the software.
2297 An ascii string containing the name of the platform.
2301 A 32bit integer sent on the trigger.
2303 CONFIG_CDP_POWER_CONSUMPTION
2305 A 16bit integer containing the power consumption of the
2306 device in .1 of milliwatts.
2308 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2310 A byte containing the id of the VLAN.
2312 - Status LED: CONFIG_STATUS_LED
2314 Several configurations allow to display the current
2315 status using a LED. For instance, the LED will blink
2316 fast while running U-Boot code, stop blinking as
2317 soon as a reply to a BOOTP request was received, and
2318 start blinking slow once the Linux kernel is running
2319 (supported by a status LED driver in the Linux
2320 kernel). Defining CONFIG_STATUS_LED enables this
2326 The status LED can be connected to a GPIO pin.
2327 In such cases, the gpio_led driver can be used as a
2328 status LED backend implementation. Define CONFIG_GPIO_LED
2329 to include the gpio_led driver in the U-Boot binary.
2331 CONFIG_GPIO_LED_INVERTED_TABLE
2332 Some GPIO connected LEDs may have inverted polarity in which
2333 case the GPIO high value corresponds to LED off state and
2334 GPIO low value corresponds to LED on state.
2335 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2336 with a list of GPIO LEDs that have inverted polarity.
2338 - CAN Support: CONFIG_CAN_DRIVER
2340 Defining CONFIG_CAN_DRIVER enables CAN driver support
2341 on those systems that support this (optional)
2342 feature, like the TQM8xxL modules.
2344 - I2C Support: CONFIG_SYS_I2C
2346 This enable the NEW i2c subsystem, and will allow you to use
2347 i2c commands at the u-boot command line (as long as you set
2348 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2349 based realtime clock chips or other i2c devices. See
2350 common/cmd_i2c.c for a description of the command line
2353 ported i2c driver to the new framework:
2354 - drivers/i2c/soft_i2c.c:
2355 - activate first bus with CONFIG_SYS_I2C_SOFT define
2356 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2357 for defining speed and slave address
2358 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2359 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2360 for defining speed and slave address
2361 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2362 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2363 for defining speed and slave address
2364 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2365 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2366 for defining speed and slave address
2368 - drivers/i2c/fsl_i2c.c:
2369 - activate i2c driver with CONFIG_SYS_I2C_FSL
2370 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2371 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2372 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2374 - If your board supports a second fsl i2c bus, define
2375 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2376 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2377 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2380 - drivers/i2c/tegra_i2c.c:
2381 - activate this driver with CONFIG_SYS_I2C_TEGRA
2382 - This driver adds 4 i2c buses with a fix speed from
2383 100000 and the slave addr 0!
2385 - drivers/i2c/ppc4xx_i2c.c
2386 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2387 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2388 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2390 - drivers/i2c/i2c_mxc.c
2391 - activate this driver with CONFIG_SYS_I2C_MXC
2392 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2393 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2394 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2395 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2396 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2397 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2398 If those defines are not set, default value is 100000
2399 for speed, and 0 for slave.
2400 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2401 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2403 - drivers/i2c/rcar_i2c.c:
2404 - activate this driver with CONFIG_SYS_I2C_RCAR
2405 - This driver adds 4 i2c buses
2407 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2408 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2409 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2410 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2411 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2412 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2413 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2414 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2415 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2417 - drivers/i2c/sh_i2c.c:
2418 - activate this driver with CONFIG_SYS_I2C_SH
2419 - This driver adds from 2 to 5 i2c buses
2421 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2422 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2423 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2424 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2425 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2426 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2427 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2428 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2429 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2430 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2431 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2432 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2433 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2435 - drivers/i2c/omap24xx_i2c.c
2436 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2437 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2438 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2439 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2440 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2441 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2442 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2443 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2444 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2445 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2446 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2448 - drivers/i2c/zynq_i2c.c
2449 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2450 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2451 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2453 - drivers/i2c/s3c24x0_i2c.c:
2454 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2455 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2456 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2457 with a fix speed from 100000 and the slave addr 0!
2459 - drivers/i2c/ihs_i2c.c
2460 - activate this driver with CONFIG_SYS_I2C_IHS
2461 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2462 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2463 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2464 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2465 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2466 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2467 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2468 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2469 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2470 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2471 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2472 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2476 CONFIG_SYS_NUM_I2C_BUSES
2477 Hold the number of i2c buses you want to use. If you
2478 don't use/have i2c muxes on your i2c bus, this
2479 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2482 CONFIG_SYS_I2C_DIRECT_BUS
2483 define this, if you don't use i2c muxes on your hardware.
2484 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2487 CONFIG_SYS_I2C_MAX_HOPS
2488 define how many muxes are maximal consecutively connected
2489 on one i2c bus. If you not use i2c muxes, omit this
2492 CONFIG_SYS_I2C_BUSES
2493 hold a list of buses you want to use, only used if
2494 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2495 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2496 CONFIG_SYS_NUM_I2C_BUSES = 9:
2498 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2499 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2500 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2501 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2502 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2503 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2504 {1, {I2C_NULL_HOP}}, \
2505 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2506 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2510 bus 0 on adapter 0 without a mux
2511 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2512 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2513 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2514 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2515 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2516 bus 6 on adapter 1 without a mux
2517 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2518 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2520 If you do not have i2c muxes on your board, omit this define.
2522 - Legacy I2C Support: CONFIG_HARD_I2C
2524 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2525 provides the following compelling advantages:
2527 - more than one i2c adapter is usable
2528 - approved multibus support
2529 - better i2c mux support
2531 ** Please consider updating your I2C driver now. **
2533 These enable legacy I2C serial bus commands. Defining
2534 CONFIG_HARD_I2C will include the appropriate I2C driver
2535 for the selected CPU.
2537 This will allow you to use i2c commands at the u-boot
2538 command line (as long as you set CONFIG_CMD_I2C in
2539 CONFIG_COMMANDS) and communicate with i2c based realtime
2540 clock chips. See common/cmd_i2c.c for a description of the
2541 command line interface.
2543 CONFIG_HARD_I2C selects a hardware I2C controller.
2545 There are several other quantities that must also be
2546 defined when you define CONFIG_HARD_I2C.
2548 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2549 to be the frequency (in Hz) at which you wish your i2c bus
2550 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2551 the CPU's i2c node address).
2553 Now, the u-boot i2c code for the mpc8xx
2554 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2555 and so its address should therefore be cleared to 0 (See,
2556 eg, MPC823e User's Manual p.16-473). So, set
2557 CONFIG_SYS_I2C_SLAVE to 0.
2559 CONFIG_SYS_I2C_INIT_MPC5XXX
2561 When a board is reset during an i2c bus transfer
2562 chips might think that the current transfer is still
2563 in progress. Reset the slave devices by sending start
2564 commands until the slave device responds.
2566 That's all that's required for CONFIG_HARD_I2C.
2568 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2569 then the following macros need to be defined (examples are
2570 from include/configs/lwmon.h):
2574 (Optional). Any commands necessary to enable the I2C
2575 controller or configure ports.
2577 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2581 (Only for MPC8260 CPU). The I/O port to use (the code
2582 assumes both bits are on the same port). Valid values
2583 are 0..3 for ports A..D.
2587 The code necessary to make the I2C data line active
2588 (driven). If the data line is open collector, this
2591 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2595 The code necessary to make the I2C data line tri-stated
2596 (inactive). If the data line is open collector, this
2599 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2603 Code that returns true if the I2C data line is high,
2606 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2610 If <bit> is true, sets the I2C data line high. If it
2611 is false, it clears it (low).
2613 eg: #define I2C_SDA(bit) \
2614 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2615 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2619 If <bit> is true, sets the I2C clock line high. If it
2620 is false, it clears it (low).
2622 eg: #define I2C_SCL(bit) \
2623 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2624 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2628 This delay is invoked four times per clock cycle so this
2629 controls the rate of data transfer. The data rate thus
2630 is 1 / (I2C_DELAY * 4). Often defined to be something
2633 #define I2C_DELAY udelay(2)
2635 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2637 If your arch supports the generic GPIO framework (asm/gpio.h),
2638 then you may alternatively define the two GPIOs that are to be
2639 used as SCL / SDA. Any of the previous I2C_xxx macros will
2640 have GPIO-based defaults assigned to them as appropriate.
2642 You should define these to the GPIO value as given directly to
2643 the generic GPIO functions.
2645 CONFIG_SYS_I2C_INIT_BOARD
2647 When a board is reset during an i2c bus transfer
2648 chips might think that the current transfer is still
2649 in progress. On some boards it is possible to access
2650 the i2c SCLK line directly, either by using the
2651 processor pin as a GPIO or by having a second pin
2652 connected to the bus. If this option is defined a
2653 custom i2c_init_board() routine in boards/xxx/board.c
2654 is run early in the boot sequence.
2656 CONFIG_SYS_I2C_BOARD_LATE_INIT
2658 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2659 defined a custom i2c_board_late_init() routine in
2660 boards/xxx/board.c is run AFTER the operations in i2c_init()
2661 is completed. This callpoint can be used to unreset i2c bus
2662 using CPU i2c controller register accesses for CPUs whose i2c
2663 controller provide such a method. It is called at the end of
2664 i2c_init() to allow i2c_init operations to setup the i2c bus
2665 controller on the CPU (e.g. setting bus speed & slave address).
2667 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2669 This option enables configuration of bi_iic_fast[] flags
2670 in u-boot bd_info structure based on u-boot environment
2671 variable "i2cfast". (see also i2cfast)
2673 CONFIG_I2C_MULTI_BUS
2675 This option allows the use of multiple I2C buses, each of which
2676 must have a controller. At any point in time, only one bus is
2677 active. To switch to a different bus, use the 'i2c dev' command.
2678 Note that bus numbering is zero-based.
2680 CONFIG_SYS_I2C_NOPROBES
2682 This option specifies a list of I2C devices that will be skipped
2683 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2684 is set, specify a list of bus-device pairs. Otherwise, specify
2685 a 1D array of device addresses
2688 #undef CONFIG_I2C_MULTI_BUS
2689 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2691 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2693 #define CONFIG_I2C_MULTI_BUS
2694 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2696 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2698 CONFIG_SYS_SPD_BUS_NUM
2700 If defined, then this indicates the I2C bus number for DDR SPD.
2701 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2703 CONFIG_SYS_RTC_BUS_NUM
2705 If defined, then this indicates the I2C bus number for the RTC.
2706 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2708 CONFIG_SYS_DTT_BUS_NUM
2710 If defined, then this indicates the I2C bus number for the DTT.
2711 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2713 CONFIG_SYS_I2C_DTT_ADDR:
2715 If defined, specifies the I2C address of the DTT device.
2716 If not defined, then U-Boot uses predefined value for
2717 specified DTT device.
2719 CONFIG_SOFT_I2C_READ_REPEATED_START
2721 defining this will force the i2c_read() function in
2722 the soft_i2c driver to perform an I2C repeated start
2723 between writing the address pointer and reading the
2724 data. If this define is omitted the default behaviour
2725 of doing a stop-start sequence will be used. Most I2C
2726 devices can use either method, but some require one or
2729 - SPI Support: CONFIG_SPI
2731 Enables SPI driver (so far only tested with
2732 SPI EEPROM, also an instance works with Crystal A/D and
2733 D/As on the SACSng board)
2737 Enables the driver for SPI controller on SuperH. Currently
2738 only SH7757 is supported.
2742 Enables extended (16-bit) SPI EEPROM addressing.
2743 (symmetrical to CONFIG_I2C_X)
2747 Enables a software (bit-bang) SPI driver rather than
2748 using hardware support. This is a general purpose
2749 driver that only requires three general I/O port pins
2750 (two outputs, one input) to function. If this is
2751 defined, the board configuration must define several
2752 SPI configuration items (port pins to use, etc). For
2753 an example, see include/configs/sacsng.h.
2757 Enables a hardware SPI driver for general-purpose reads
2758 and writes. As with CONFIG_SOFT_SPI, the board configuration
2759 must define a list of chip-select function pointers.
2760 Currently supported on some MPC8xxx processors. For an
2761 example, see include/configs/mpc8349emds.h.
2765 Enables the driver for the SPI controllers on i.MX and MXC
2766 SoCs. Currently i.MX31/35/51 are supported.
2768 CONFIG_SYS_SPI_MXC_WAIT
2769 Timeout for waiting until spi transfer completed.
2770 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2772 - FPGA Support: CONFIG_FPGA
2774 Enables FPGA subsystem.
2776 CONFIG_FPGA_<vendor>
2778 Enables support for specific chip vendors.
2781 CONFIG_FPGA_<family>
2783 Enables support for FPGA family.
2784 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2788 Specify the number of FPGA devices to support.
2790 CONFIG_CMD_FPGA_LOADMK
2792 Enable support for fpga loadmk command
2794 CONFIG_CMD_FPGA_LOADP
2796 Enable support for fpga loadp command - load partial bitstream
2798 CONFIG_CMD_FPGA_LOADBP
2800 Enable support for fpga loadbp command - load partial bitstream
2803 CONFIG_SYS_FPGA_PROG_FEEDBACK
2805 Enable printing of hash marks during FPGA configuration.
2807 CONFIG_SYS_FPGA_CHECK_BUSY
2809 Enable checks on FPGA configuration interface busy
2810 status by the configuration function. This option
2811 will require a board or device specific function to
2816 If defined, a function that provides delays in the FPGA
2817 configuration driver.
2819 CONFIG_SYS_FPGA_CHECK_CTRLC
2820 Allow Control-C to interrupt FPGA configuration
2822 CONFIG_SYS_FPGA_CHECK_ERROR
2824 Check for configuration errors during FPGA bitfile
2825 loading. For example, abort during Virtex II
2826 configuration if the INIT_B line goes low (which
2827 indicated a CRC error).
2829 CONFIG_SYS_FPGA_WAIT_INIT
2831 Maximum time to wait for the INIT_B line to de-assert
2832 after PROB_B has been de-asserted during a Virtex II
2833 FPGA configuration sequence. The default time is 500
2836 CONFIG_SYS_FPGA_WAIT_BUSY
2838 Maximum time to wait for BUSY to de-assert during
2839 Virtex II FPGA configuration. The default is 5 ms.
2841 CONFIG_SYS_FPGA_WAIT_CONFIG
2843 Time to wait after FPGA configuration. The default is
2846 - Configuration Management:
2849 Some SoCs need special image types (e.g. U-Boot binary
2850 with a special header) as build targets. By defining
2851 CONFIG_BUILD_TARGET in the SoC / board header, this
2852 special image will be automatically built upon calling
2857 If defined, this string will be added to the U-Boot
2858 version information (U_BOOT_VERSION)
2860 - Vendor Parameter Protection:
2862 U-Boot considers the values of the environment
2863 variables "serial#" (Board Serial Number) and
2864 "ethaddr" (Ethernet Address) to be parameters that
2865 are set once by the board vendor / manufacturer, and
2866 protects these variables from casual modification by
2867 the user. Once set, these variables are read-only,
2868 and write or delete attempts are rejected. You can
2869 change this behaviour:
2871 If CONFIG_ENV_OVERWRITE is #defined in your config
2872 file, the write protection for vendor parameters is
2873 completely disabled. Anybody can change or delete
2876 Alternatively, if you #define _both_ CONFIG_ETHADDR
2877 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2878 Ethernet address is installed in the environment,
2879 which can be changed exactly ONCE by the user. [The
2880 serial# is unaffected by this, i. e. it remains
2883 The same can be accomplished in a more flexible way
2884 for any variable by configuring the type of access
2885 to allow for those variables in the ".flags" variable
2886 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2891 Define this variable to enable the reservation of
2892 "protected RAM", i. e. RAM which is not overwritten
2893 by U-Boot. Define CONFIG_PRAM to hold the number of
2894 kB you want to reserve for pRAM. You can overwrite
2895 this default value by defining an environment
2896 variable "pram" to the number of kB you want to
2897 reserve. Note that the board info structure will
2898 still show the full amount of RAM. If pRAM is
2899 reserved, a new environment variable "mem" will
2900 automatically be defined to hold the amount of
2901 remaining RAM in a form that can be passed as boot
2902 argument to Linux, for instance like that:
2904 setenv bootargs ... mem=\${mem}
2907 This way you can tell Linux not to use this memory,
2908 either, which results in a memory region that will
2909 not be affected by reboots.
2911 *WARNING* If your board configuration uses automatic
2912 detection of the RAM size, you must make sure that
2913 this memory test is non-destructive. So far, the
2914 following board configurations are known to be
2917 IVMS8, IVML24, SPD8xx, TQM8xxL,
2918 HERMES, IP860, RPXlite, LWMON,
2921 - Access to physical memory region (> 4GB)
2922 Some basic support is provided for operations on memory not
2923 normally accessible to U-Boot - e.g. some architectures
2924 support access to more than 4GB of memory on 32-bit
2925 machines using physical address extension or similar.
2926 Define CONFIG_PHYSMEM to access this basic support, which
2927 currently only supports clearing the memory.
2932 Define this variable to stop the system in case of a
2933 fatal error, so that you have to reset it manually.
2934 This is probably NOT a good idea for an embedded
2935 system where you want the system to reboot
2936 automatically as fast as possible, but it may be
2937 useful during development since you can try to debug
2938 the conditions that lead to the situation.
2940 CONFIG_NET_RETRY_COUNT
2942 This variable defines the number of retries for
2943 network operations like ARP, RARP, TFTP, or BOOTP
2944 before giving up the operation. If not defined, a
2945 default value of 5 is used.
2949 Timeout waiting for an ARP reply in milliseconds.
2953 Timeout in milliseconds used in NFS protocol.
2954 If you encounter "ERROR: Cannot umount" in nfs command,
2955 try longer timeout such as
2956 #define CONFIG_NFS_TIMEOUT 10000UL
2958 - Command Interpreter:
2959 CONFIG_AUTO_COMPLETE
2961 Enable auto completion of commands using TAB.
2963 CONFIG_SYS_PROMPT_HUSH_PS2
2965 This defines the secondary prompt string, which is
2966 printed when the command interpreter needs more input
2967 to complete a command. Usually "> ".
2971 In the current implementation, the local variables
2972 space and global environment variables space are
2973 separated. Local variables are those you define by
2974 simply typing `name=value'. To access a local
2975 variable later on, you have write `$name' or
2976 `${name}'; to execute the contents of a variable
2977 directly type `$name' at the command prompt.
2979 Global environment variables are those you use
2980 setenv/printenv to work with. To run a command stored
2981 in such a variable, you need to use the run command,
2982 and you must not use the '$' sign to access them.
2984 To store commands and special characters in a
2985 variable, please use double quotation marks
2986 surrounding the whole text of the variable, instead
2987 of the backslashes before semicolons and special
2990 - Command Line Editing and History:
2991 CONFIG_CMDLINE_EDITING
2993 Enable editing and History functions for interactive
2994 command line input operations
2996 - Default Environment:
2997 CONFIG_EXTRA_ENV_SETTINGS
2999 Define this to contain any number of null terminated
3000 strings (variable = value pairs) that will be part of
3001 the default environment compiled into the boot image.
3003 For example, place something like this in your
3004 board's config file:
3006 #define CONFIG_EXTRA_ENV_SETTINGS \
3010 Warning: This method is based on knowledge about the
3011 internal format how the environment is stored by the
3012 U-Boot code. This is NOT an official, exported
3013 interface! Although it is unlikely that this format
3014 will change soon, there is no guarantee either.
3015 You better know what you are doing here.
3017 Note: overly (ab)use of the default environment is
3018 discouraged. Make sure to check other ways to preset
3019 the environment like the "source" command or the
3022 CONFIG_ENV_VARS_UBOOT_CONFIG
3024 Define this in order to add variables describing the
3025 U-Boot build configuration to the default environment.
3026 These will be named arch, cpu, board, vendor, and soc.
3028 Enabling this option will cause the following to be defined:
3036 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3038 Define this in order to add variables describing certain
3039 run-time determined information about the hardware to the
3040 environment. These will be named board_name, board_rev.
3042 CONFIG_DELAY_ENVIRONMENT
3044 Normally the environment is loaded when the board is
3045 initialised so that it is available to U-Boot. This inhibits
3046 that so that the environment is not available until
3047 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3048 this is instead controlled by the value of
3049 /config/load-environment.
3051 - DataFlash Support:
3052 CONFIG_HAS_DATAFLASH
3054 Defining this option enables DataFlash features and
3055 allows to read/write in Dataflash via the standard
3058 - Serial Flash support
3061 Defining this option enables SPI flash commands
3062 'sf probe/read/write/erase/update'.
3064 Usage requires an initial 'probe' to define the serial
3065 flash parameters, followed by read/write/erase/update
3068 The following defaults may be provided by the platform
3069 to handle the common case when only a single serial
3070 flash is present on the system.
3072 CONFIG_SF_DEFAULT_BUS Bus identifier
3073 CONFIG_SF_DEFAULT_CS Chip-select
3074 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3075 CONFIG_SF_DEFAULT_SPEED in Hz
3079 Define this option to include a destructive SPI flash
3082 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3084 Define this option to use the Bank addr/Extended addr
3085 support on SPI flashes which has size > 16Mbytes.
3087 CONFIG_SF_DUAL_FLASH Dual flash memories
3089 Define this option to use dual flash support where two flash
3090 memories can be connected with a given cs line.
3091 Currently Xilinx Zynq qspi supports these type of connections.
3093 - SystemACE Support:
3096 Adding this option adds support for Xilinx SystemACE
3097 chips attached via some sort of local bus. The address
3098 of the chip must also be defined in the
3099 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3101 #define CONFIG_SYSTEMACE
3102 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3104 When SystemACE support is added, the "ace" device type
3105 becomes available to the fat commands, i.e. fatls.
3107 - TFTP Fixed UDP Port:
3110 If this is defined, the environment variable tftpsrcp
3111 is used to supply the TFTP UDP source port value.
3112 If tftpsrcp isn't defined, the normal pseudo-random port
3113 number generator is used.
3115 Also, the environment variable tftpdstp is used to supply
3116 the TFTP UDP destination port value. If tftpdstp isn't
3117 defined, the normal port 69 is used.
3119 The purpose for tftpsrcp is to allow a TFTP server to
3120 blindly start the TFTP transfer using the pre-configured
3121 target IP address and UDP port. This has the effect of
3122 "punching through" the (Windows XP) firewall, allowing
3123 the remainder of the TFTP transfer to proceed normally.
3124 A better solution is to properly configure the firewall,
3125 but sometimes that is not allowed.
3130 This enables a generic 'hash' command which can produce
3131 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3135 Enable the hash verify command (hash -v). This adds to code
3138 CONFIG_SHA1 - This option enables support of hashing using SHA1
3139 algorithm. The hash is calculated in software.
3140 CONFIG_SHA256 - This option enables support of hashing using
3141 SHA256 algorithm. The hash is calculated in software.
3142 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3143 for SHA1/SHA256 hashing.
3144 This affects the 'hash' command and also the
3145 hash_lookup_algo() function.
3146 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3147 hardware-acceleration for SHA1/SHA256 progressive hashing.
3148 Data can be streamed in a block at a time and the hashing
3149 is performed in hardware.
3151 Note: There is also a sha1sum command, which should perhaps
3152 be deprecated in favour of 'hash sha1'.
3154 - Freescale i.MX specific commands:
3155 CONFIG_CMD_HDMIDETECT
3156 This enables 'hdmidet' command which returns true if an
3157 HDMI monitor is detected. This command is i.MX 6 specific.
3160 This enables the 'bmode' (bootmode) command for forcing
3161 a boot from specific media.
3163 This is useful for forcing the ROM's usb downloader to
3164 activate upon a watchdog reset which is nice when iterating
3165 on U-Boot. Using the reset button or running bmode normal
3166 will set it back to normal. This command currently
3167 supports i.MX53 and i.MX6.
3172 This enables the RSA algorithm used for FIT image verification
3173 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3175 The Modular Exponentiation algorithm in RSA is implemented using
3176 driver model. So CONFIG_DM needs to be enabled by default for this
3177 library to function.
3179 The signing part is build into mkimage regardless of this
3180 option. The software based modular exponentiation is built into
3181 mkimage irrespective of this option.
3183 - bootcount support:
3184 CONFIG_BOOTCOUNT_LIMIT
3186 This enables the bootcounter support, see:
3187 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3190 enable special bootcounter support on at91sam9xe based boards.
3192 enable special bootcounter support on blackfin based boards.
3194 enable special bootcounter support on da850 based boards.
3195 CONFIG_BOOTCOUNT_RAM
3196 enable support for the bootcounter in RAM
3197 CONFIG_BOOTCOUNT_I2C
3198 enable support for the bootcounter on an i2c (like RTC) device.
3199 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3200 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3202 CONFIG_BOOTCOUNT_ALEN = address len
3204 - Show boot progress:
3205 CONFIG_SHOW_BOOT_PROGRESS
3207 Defining this option allows to add some board-
3208 specific code (calling a user-provided function
3209 "show_boot_progress(int)") that enables you to show
3210 the system's boot progress on some display (for
3211 example, some LED's) on your board. At the moment,
3212 the following checkpoints are implemented:
3215 Legacy uImage format:
3218 1 common/cmd_bootm.c before attempting to boot an image
3219 -1 common/cmd_bootm.c Image header has bad magic number
3220 2 common/cmd_bootm.c Image header has correct magic number
3221 -2 common/cmd_bootm.c Image header has bad checksum
3222 3 common/cmd_bootm.c Image header has correct checksum
3223 -3 common/cmd_bootm.c Image data has bad checksum
3224 4 common/cmd_bootm.c Image data has correct checksum
3225 -4 common/cmd_bootm.c Image is for unsupported architecture
3226 5 common/cmd_bootm.c Architecture check OK
3227 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3228 6 common/cmd_bootm.c Image Type check OK
3229 -6 common/cmd_bootm.c gunzip uncompression error
3230 -7 common/cmd_bootm.c Unimplemented compression type
3231 7 common/cmd_bootm.c Uncompression OK
3232 8 common/cmd_bootm.c No uncompress/copy overwrite error
3233 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3235 9 common/image.c Start initial ramdisk verification
3236 -10 common/image.c Ramdisk header has bad magic number
3237 -11 common/image.c Ramdisk header has bad checksum
3238 10 common/image.c Ramdisk header is OK
3239 -12 common/image.c Ramdisk data has bad checksum
3240 11 common/image.c Ramdisk data has correct checksum
3241 12 common/image.c Ramdisk verification complete, start loading
3242 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3243 13 common/image.c Start multifile image verification
3244 14 common/image.c No initial ramdisk, no multifile, continue.
3246 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3248 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3249 -31 post/post.c POST test failed, detected by post_output_backlog()
3250 -32 post/post.c POST test failed, detected by post_run_single()
3252 34 common/cmd_doc.c before loading a Image from a DOC device
3253 -35 common/cmd_doc.c Bad usage of "doc" command
3254 35 common/cmd_doc.c correct usage of "doc" command
3255 -36 common/cmd_doc.c No boot device
3256 36 common/cmd_doc.c correct boot device
3257 -37 common/cmd_doc.c Unknown Chip ID on boot device
3258 37 common/cmd_doc.c correct chip ID found, device available
3259 -38 common/cmd_doc.c Read Error on boot device
3260 38 common/cmd_doc.c reading Image header from DOC device OK
3261 -39 common/cmd_doc.c Image header has bad magic number
3262 39 common/cmd_doc.c Image header has correct magic number
3263 -40 common/cmd_doc.c Error reading Image from DOC device
3264 40 common/cmd_doc.c Image header has correct magic number
3265 41 common/cmd_ide.c before loading a Image from a IDE device
3266 -42 common/cmd_ide.c Bad usage of "ide" command
3267 42 common/cmd_ide.c correct usage of "ide" command
3268 -43 common/cmd_ide.c No boot device
3269 43 common/cmd_ide.c boot device found
3270 -44 common/cmd_ide.c Device not available
3271 44 common/cmd_ide.c Device available
3272 -45 common/cmd_ide.c wrong partition selected
3273 45 common/cmd_ide.c partition selected
3274 -46 common/cmd_ide.c Unknown partition table
3275 46 common/cmd_ide.c valid partition table found
3276 -47 common/cmd_ide.c Invalid partition type
3277 47 common/cmd_ide.c correct partition type
3278 -48 common/cmd_ide.c Error reading Image Header on boot device
3279 48 common/cmd_ide.c reading Image Header from IDE device OK
3280 -49 common/cmd_ide.c Image header has bad magic number
3281 49 common/cmd_ide.c Image header has correct magic number
3282 -50 common/cmd_ide.c Image header has bad checksum
3283 50 common/cmd_ide.c Image header has correct checksum
3284 -51 common/cmd_ide.c Error reading Image from IDE device
3285 51 common/cmd_ide.c reading Image from IDE device OK
3286 52 common/cmd_nand.c before loading a Image from a NAND device
3287 -53 common/cmd_nand.c Bad usage of "nand" command
3288 53 common/cmd_nand.c correct usage of "nand" command
3289 -54 common/cmd_nand.c No boot device
3290 54 common/cmd_nand.c boot device found
3291 -55 common/cmd_nand.c Unknown Chip ID on boot device
3292 55 common/cmd_nand.c correct chip ID found, device available
3293 -56 common/cmd_nand.c Error reading Image Header on boot device
3294 56 common/cmd_nand.c reading Image Header from NAND device OK
3295 -57 common/cmd_nand.c Image header has bad magic number
3296 57 common/cmd_nand.c Image header has correct magic number
3297 -58 common/cmd_nand.c Error reading Image from NAND device
3298 58 common/cmd_nand.c reading Image from NAND device OK
3300 -60 common/env_common.c Environment has a bad CRC, using default
3302 64 net/eth.c starting with Ethernet configuration.
3303 -64 net/eth.c no Ethernet found.
3304 65 net/eth.c Ethernet found.
3306 -80 common/cmd_net.c usage wrong
3307 80 common/cmd_net.c before calling net_loop()
3308 -81 common/cmd_net.c some error in net_loop() occurred
3309 81 common/cmd_net.c net_loop() back without error
3310 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3311 82 common/cmd_net.c trying automatic boot
3312 83 common/cmd_net.c running "source" command
3313 -83 common/cmd_net.c some error in automatic boot or "source" command
3314 84 common/cmd_net.c end without errors
3319 100 common/cmd_bootm.c Kernel FIT Image has correct format
3320 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3321 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3322 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3323 102 common/cmd_bootm.c Kernel unit name specified
3324 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3325 103 common/cmd_bootm.c Found configuration node
3326 104 common/cmd_bootm.c Got kernel subimage node offset
3327 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3328 105 common/cmd_bootm.c Kernel subimage hash verification OK
3329 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3330 106 common/cmd_bootm.c Architecture check OK
3331 -106 common/cmd_bootm.c Kernel subimage has wrong type
3332 107 common/cmd_bootm.c Kernel subimage type OK
3333 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3334 108 common/cmd_bootm.c Got kernel subimage data/size
3335 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3336 -109 common/cmd_bootm.c Can't get kernel subimage type
3337 -110 common/cmd_bootm.c Can't get kernel subimage comp
3338 -111 common/cmd_bootm.c Can't get kernel subimage os
3339 -112 common/cmd_bootm.c Can't get kernel subimage load address
3340 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3342 120 common/image.c Start initial ramdisk verification
3343 -120 common/image.c Ramdisk FIT image has incorrect format
3344 121 common/image.c Ramdisk FIT image has correct format
3345 122 common/image.c No ramdisk subimage unit name, using configuration
3346 -122 common/image.c Can't get configuration for ramdisk subimage
3347 123 common/image.c Ramdisk unit name specified
3348 -124 common/image.c Can't get ramdisk subimage node offset
3349 125 common/image.c Got ramdisk subimage node offset
3350 -125 common/image.c Ramdisk subimage hash verification failed
3351 126 common/image.c Ramdisk subimage hash verification OK
3352 -126 common/image.c Ramdisk subimage for unsupported architecture
3353 127 common/image.c Architecture check OK
3354 -127 common/image.c Can't get ramdisk subimage data/size
3355 128 common/image.c Got ramdisk subimage data/size
3356 129 common/image.c Can't get ramdisk load address
3357 -129 common/image.c Got ramdisk load address
3359 -130 common/cmd_doc.c Incorrect FIT image format
3360 131 common/cmd_doc.c FIT image format OK
3362 -140 common/cmd_ide.c Incorrect FIT image format
3363 141 common/cmd_ide.c FIT image format OK
3365 -150 common/cmd_nand.c Incorrect FIT image format
3366 151 common/cmd_nand.c FIT image format OK
3368 - legacy image format:
3369 CONFIG_IMAGE_FORMAT_LEGACY
3370 enables the legacy image format support in U-Boot.
3373 enabled if CONFIG_FIT_SIGNATURE is not defined.
3375 CONFIG_DISABLE_IMAGE_LEGACY
3376 disable the legacy image format
3378 This define is introduced, as the legacy image format is
3379 enabled per default for backward compatibility.
3381 - FIT image support:
3383 Enable support for the FIT uImage format.
3385 CONFIG_FIT_BEST_MATCH
3386 When no configuration is explicitly selected, default to the
3387 one whose fdt's compatibility field best matches that of
3388 U-Boot itself. A match is considered "best" if it matches the
3389 most specific compatibility entry of U-Boot's fdt's root node.
3390 The order of entries in the configuration's fdt is ignored.
3392 CONFIG_FIT_SIGNATURE
3393 This option enables signature verification of FIT uImages,
3394 using a hash signed and verified using RSA. If
3395 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3396 hashing is available using hardware, RSA library will use it.
3397 See doc/uImage.FIT/signature.txt for more details.
3399 WARNING: When relying on signed FIT images with required
3400 signature check the legacy image format is default
3401 disabled. If a board need legacy image format support
3402 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3404 CONFIG_FIT_DISABLE_SHA256
3405 Supporting SHA256 hashes has quite an impact on binary size.
3406 For constrained systems sha256 hash support can be disabled
3409 - Standalone program support:
3410 CONFIG_STANDALONE_LOAD_ADDR
3412 This option defines a board specific value for the
3413 address where standalone program gets loaded, thus
3414 overwriting the architecture dependent default
3417 - Frame Buffer Address:
3420 Define CONFIG_FB_ADDR if you want to use specific
3421 address for frame buffer. This is typically the case
3422 when using a graphics controller has separate video
3423 memory. U-Boot will then place the frame buffer at
3424 the given address instead of dynamically reserving it
3425 in system RAM by calling lcd_setmem(), which grabs
3426 the memory for the frame buffer depending on the
3427 configured panel size.
3429 Please see board_init_f function.
3431 - Automatic software updates via TFTP server
3433 CONFIG_UPDATE_TFTP_CNT_MAX
3434 CONFIG_UPDATE_TFTP_MSEC_MAX
3436 These options enable and control the auto-update feature;
3437 for a more detailed description refer to doc/README.update.
3439 - MTD Support (mtdparts command, UBI support)
3442 Adds the MTD device infrastructure from the Linux kernel.
3443 Needed for mtdparts command support.
3445 CONFIG_MTD_PARTITIONS
3447 Adds the MTD partitioning infrastructure from the Linux
3448 kernel. Needed for UBI support.
3453 Adds commands for interacting with MTD partitions formatted
3454 with the UBI flash translation layer
3456 Requires also defining CONFIG_RBTREE
3458 CONFIG_UBI_SILENCE_MSG
3460 Make the verbose messages from UBI stop printing. This leaves
3461 warnings and errors enabled.
3464 CONFIG_MTD_UBI_WL_THRESHOLD
3465 This parameter defines the maximum difference between the highest
3466 erase counter value and the lowest erase counter value of eraseblocks
3467 of UBI devices. When this threshold is exceeded, UBI starts performing
3468 wear leveling by means of moving data from eraseblock with low erase
3469 counter to eraseblocks with high erase counter.
3471 The default value should be OK for SLC NAND flashes, NOR flashes and
3472 other flashes which have eraseblock life-cycle 100000 or more.
3473 However, in case of MLC NAND flashes which typically have eraseblock
3474 life-cycle less than 10000, the threshold should be lessened (e.g.,
3475 to 128 or 256, although it does not have to be power of 2).
3479 CONFIG_MTD_UBI_BEB_LIMIT
3480 This option specifies the maximum bad physical eraseblocks UBI
3481 expects on the MTD device (per 1024 eraseblocks). If the
3482 underlying flash does not admit of bad eraseblocks (e.g. NOR
3483 flash), this value is ignored.
3485 NAND datasheets often specify the minimum and maximum NVM
3486 (Number of Valid Blocks) for the flashes' endurance lifetime.
3487 The maximum expected bad eraseblocks per 1024 eraseblocks
3488 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3489 which gives 20 for most NANDs (MaxNVB is basically the total
3490 count of eraseblocks on the chip).
3492 To put it differently, if this value is 20, UBI will try to
3493 reserve about 1.9% of physical eraseblocks for bad blocks
3494 handling. And that will be 1.9% of eraseblocks on the entire
3495 NAND chip, not just the MTD partition UBI attaches. This means
3496 that if you have, say, a NAND flash chip admits maximum 40 bad
3497 eraseblocks, and it is split on two MTD partitions of the same
3498 size, UBI will reserve 40 eraseblocks when attaching a
3503 CONFIG_MTD_UBI_FASTMAP
3504 Fastmap is a mechanism which allows attaching an UBI device
3505 in nearly constant time. Instead of scanning the whole MTD device it
3506 only has to locate a checkpoint (called fastmap) on the device.
3507 The on-flash fastmap contains all information needed to attach
3508 the device. Using fastmap makes only sense on large devices where
3509 attaching by scanning takes long. UBI will not automatically install
3510 a fastmap on old images, but you can set the UBI parameter
3511 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3512 that fastmap-enabled images are still usable with UBI implementations
3513 without fastmap support. On typical flash devices the whole fastmap
3514 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3516 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3517 Set this parameter to enable fastmap automatically on images
3524 Adds commands for interacting with UBI volumes formatted as
3525 UBIFS. UBIFS is read-only in u-boot.
3527 Requires UBI support as well as CONFIG_LZO
3529 CONFIG_UBIFS_SILENCE_MSG
3531 Make the verbose messages from UBIFS stop printing. This leaves
3532 warnings and errors enabled.
3536 Enable building of SPL globally.
3539 LDSCRIPT for linking the SPL binary.
3541 CONFIG_SPL_MAX_FOOTPRINT
3542 Maximum size in memory allocated to the SPL, BSS included.
3543 When defined, the linker checks that the actual memory
3544 used by SPL from _start to __bss_end does not exceed it.
3545 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3546 must not be both defined at the same time.
3549 Maximum size of the SPL image (text, data, rodata, and
3550 linker lists sections), BSS excluded.
3551 When defined, the linker checks that the actual size does
3554 CONFIG_SPL_TEXT_BASE
3555 TEXT_BASE for linking the SPL binary.
3557 CONFIG_SPL_RELOC_TEXT_BASE
3558 Address to relocate to. If unspecified, this is equal to
3559 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3561 CONFIG_SPL_BSS_START_ADDR
3562 Link address for the BSS within the SPL binary.
3564 CONFIG_SPL_BSS_MAX_SIZE
3565 Maximum size in memory allocated to the SPL BSS.
3566 When defined, the linker checks that the actual memory used
3567 by SPL from __bss_start to __bss_end does not exceed it.
3568 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3569 must not be both defined at the same time.
3572 Adress of the start of the stack SPL will use
3574 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3575 When defined, SPL will panic() if the image it has
3576 loaded does not have a signature.
3577 Defining this is useful when code which loads images
3578 in SPL cannot guarantee that absolutely all read errors
3580 An example is the LPC32XX MLC NAND driver, which will
3581 consider that a completely unreadable NAND block is bad,
3582 and thus should be skipped silently.
3584 CONFIG_SPL_RELOC_STACK
3585 Adress of the start of the stack SPL will use after
3586 relocation. If unspecified, this is equal to
3589 CONFIG_SYS_SPL_MALLOC_START
3590 Starting address of the malloc pool used in SPL.
3592 CONFIG_SYS_SPL_MALLOC_SIZE
3593 The size of the malloc pool used in SPL.
3595 CONFIG_SPL_FRAMEWORK
3596 Enable the SPL framework under common/. This framework
3597 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3598 NAND loading of the Linux Kernel.
3601 Enable booting directly to an OS from SPL.
3602 See also: doc/README.falcon
3604 CONFIG_SPL_DISPLAY_PRINT
3605 For ARM, enable an optional function to print more information
3606 about the running system.
3608 CONFIG_SPL_INIT_MINIMAL
3609 Arch init code should be built for a very small image
3611 CONFIG_SPL_LIBCOMMON_SUPPORT
3612 Support for common/libcommon.o in SPL binary
3614 CONFIG_SPL_LIBDISK_SUPPORT
3615 Support for disk/libdisk.o in SPL binary
3617 CONFIG_SPL_I2C_SUPPORT
3618 Support for drivers/i2c/libi2c.o in SPL binary
3620 CONFIG_SPL_GPIO_SUPPORT
3621 Support for drivers/gpio/libgpio.o in SPL binary
3623 CONFIG_SPL_MMC_SUPPORT
3624 Support for drivers/mmc/libmmc.o in SPL binary
3626 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3627 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3628 Address and partition on the MMC to load U-Boot from
3629 when the MMC is being used in raw mode.
3631 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3632 Partition on the MMC to load U-Boot from when the MMC is being
3635 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3636 Sector to load kernel uImage from when MMC is being
3637 used in raw mode (for Falcon mode)
3639 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3640 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3641 Sector and number of sectors to load kernel argument
3642 parameters from when MMC is being used in raw mode
3645 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3646 Partition on the MMC to load U-Boot from when the MMC is being
3649 CONFIG_SPL_FAT_SUPPORT
3650 Support for fs/fat/libfat.o in SPL binary
3652 CONFIG_SPL_EXT_SUPPORT
3653 Support for EXT filesystem in SPL binary
3655 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3656 Filename to read to load U-Boot when reading from filesystem
3658 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3659 Filename to read to load kernel uImage when reading
3660 from filesystem (for Falcon mode)
3662 CONFIG_SPL_FS_LOAD_ARGS_NAME
3663 Filename to read to load kernel argument parameters
3664 when reading from filesystem (for Falcon mode)
3666 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3667 Set this for NAND SPL on PPC mpc83xx targets, so that
3668 start.S waits for the rest of the SPL to load before
3669 continuing (the hardware starts execution after just
3670 loading the first page rather than the full 4K).
3672 CONFIG_SPL_SKIP_RELOCATE
3673 Avoid SPL relocation
3675 CONFIG_SPL_NAND_BASE
3676 Include nand_base.c in the SPL. Requires
3677 CONFIG_SPL_NAND_DRIVERS.
3679 CONFIG_SPL_NAND_DRIVERS
3680 SPL uses normal NAND drivers, not minimal drivers.
3683 Include standard software ECC in the SPL
3685 CONFIG_SPL_NAND_SIMPLE
3686 Support for NAND boot using simple NAND drivers that
3687 expose the cmd_ctrl() interface.
3689 CONFIG_SPL_MTD_SUPPORT
3690 Support for the MTD subsystem within SPL. Useful for
3691 environment on NAND support within SPL.
3693 CONFIG_SPL_NAND_RAW_ONLY
3694 Support to boot only raw u-boot.bin images. Use this only
3695 if you need to save space.
3697 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3698 Set for the SPL on PPC mpc8xxx targets, support for
3699 drivers/ddr/fsl/libddr.o in SPL binary.
3701 CONFIG_SPL_COMMON_INIT_DDR
3702 Set for common ddr init with serial presence detect in
3705 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3706 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3707 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3708 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3709 CONFIG_SYS_NAND_ECCBYTES
3710 Defines the size and behavior of the NAND that SPL uses
3713 CONFIG_SPL_NAND_BOOT
3714 Add support NAND boot
3716 CONFIG_SYS_NAND_U_BOOT_OFFS
3717 Location in NAND to read U-Boot from
3719 CONFIG_SYS_NAND_U_BOOT_DST
3720 Location in memory to load U-Boot to
3722 CONFIG_SYS_NAND_U_BOOT_SIZE
3723 Size of image to load
3725 CONFIG_SYS_NAND_U_BOOT_START
3726 Entry point in loaded image to jump to
3728 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3729 Define this if you need to first read the OOB and then the
3730 data. This is used, for example, on davinci platforms.
3732 CONFIG_SPL_OMAP3_ID_NAND
3733 Support for an OMAP3-specific set of functions to return the
3734 ID and MFR of the first attached NAND chip, if present.
3736 CONFIG_SPL_SERIAL_SUPPORT
3737 Support for drivers/serial/libserial.o in SPL binary
3739 CONFIG_SPL_SPI_FLASH_SUPPORT
3740 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3742 CONFIG_SPL_SPI_SUPPORT
3743 Support for drivers/spi/libspi.o in SPL binary
3745 CONFIG_SPL_RAM_DEVICE
3746 Support for running image already present in ram, in SPL binary
3748 CONFIG_SPL_LIBGENERIC_SUPPORT
3749 Support for lib/libgeneric.o in SPL binary
3751 CONFIG_SPL_ENV_SUPPORT
3752 Support for the environment operating in SPL binary
3754 CONFIG_SPL_NET_SUPPORT
3755 Support for the net/libnet.o in SPL binary.
3756 It conflicts with SPL env from storage medium specified by
3757 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3760 Image offset to which the SPL should be padded before appending
3761 the SPL payload. By default, this is defined as
3762 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3763 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3764 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3767 Final target image containing SPL and payload. Some SPLs
3768 use an arch-specific makefile fragment instead, for
3769 example if more than one image needs to be produced.
3771 CONFIG_FIT_SPL_PRINT
3772 Printing information about a FIT image adds quite a bit of
3773 code to SPL. So this is normally disabled in SPL. Use this
3774 option to re-enable it. This will affect the output of the
3775 bootm command when booting a FIT image.
3779 Enable building of TPL globally.
3782 Image offset to which the TPL should be padded before appending
3783 the TPL payload. By default, this is defined as
3784 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3785 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3786 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3791 [so far only for SMDK2400 boards]
3793 - Modem support enable:
3794 CONFIG_MODEM_SUPPORT
3796 - RTS/CTS Flow control enable:
3799 - Modem debug support:
3800 CONFIG_MODEM_SUPPORT_DEBUG
3802 Enables debugging stuff (char screen[1024], dbg())
3803 for modem support. Useful only with BDI2000.
3805 - Interrupt support (PPC):
3807 There are common interrupt_init() and timer_interrupt()
3808 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3809 for CPU specific initialization. interrupt_init_cpu()
3810 should set decrementer_count to appropriate value. If
3811 CPU resets decrementer automatically after interrupt
3812 (ppc4xx) it should set decrementer_count to zero.
3813 timer_interrupt() calls timer_interrupt_cpu() for CPU
3814 specific handling. If board has watchdog / status_led
3815 / other_activity_monitor it works automatically from
3816 general timer_interrupt().
3820 In the target system modem support is enabled when a
3821 specific key (key combination) is pressed during
3822 power-on. Otherwise U-Boot will boot normally
3823 (autoboot). The key_pressed() function is called from
3824 board_init(). Currently key_pressed() is a dummy
3825 function, returning 1 and thus enabling modem
3828 If there are no modem init strings in the
3829 environment, U-Boot proceed to autoboot; the
3830 previous output (banner, info printfs) will be
3833 See also: doc/README.Modem
3835 Board initialization settings:
3836 ------------------------------
3838 During Initialization u-boot calls a number of board specific functions
3839 to allow the preparation of board specific prerequisites, e.g. pin setup
3840 before drivers are initialized. To enable these callbacks the
3841 following configuration macros have to be defined. Currently this is
3842 architecture specific, so please check arch/your_architecture/lib/board.c
3843 typically in board_init_f() and board_init_r().
3845 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3846 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3847 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3848 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3850 Configuration Settings:
3851 -----------------------
3853 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3854 Optionally it can be defined to support 64-bit memory commands.
3856 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3857 undefine this when you're short of memory.
3859 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3860 width of the commands listed in the 'help' command output.
3862 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3863 prompt for user input.
3865 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3867 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3869 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3871 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3872 the application (usually a Linux kernel) when it is
3875 - CONFIG_SYS_BAUDRATE_TABLE:
3876 List of legal baudrate settings for this board.
3878 - CONFIG_SYS_CONSOLE_INFO_QUIET
3879 Suppress display of console information at boot.
3881 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3882 If the board specific function
3883 extern int overwrite_console (void);
3884 returns 1, the stdin, stderr and stdout are switched to the
3885 serial port, else the settings in the environment are used.
3887 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3888 Enable the call to overwrite_console().
3890 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3891 Enable overwrite of previous console environment settings.
3893 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3894 Begin and End addresses of the area used by the
3897 - CONFIG_SYS_ALT_MEMTEST:
3898 Enable an alternate, more extensive memory test.
3900 - CONFIG_SYS_MEMTEST_SCRATCH:
3901 Scratch address used by the alternate memory test
3902 You only need to set this if address zero isn't writeable
3904 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3905 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3906 this specified memory area will get subtracted from the top
3907 (end) of RAM and won't get "touched" at all by U-Boot. By
3908 fixing up gd->ram_size the Linux kernel should gets passed
3909 the now "corrected" memory size and won't touch it either.
3910 This should work for arch/ppc and arch/powerpc. Only Linux
3911 board ports in arch/powerpc with bootwrapper support that
3912 recalculate the memory size from the SDRAM controller setup
3913 will have to get fixed in Linux additionally.
3915 This option can be used as a workaround for the 440EPx/GRx
3916 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3919 WARNING: Please make sure that this value is a multiple of
3920 the Linux page size (normally 4k). If this is not the case,
3921 then the end address of the Linux memory will be located at a
3922 non page size aligned address and this could cause major
3925 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3926 Enable temporary baudrate change while serial download
3928 - CONFIG_SYS_SDRAM_BASE:
3929 Physical start address of SDRAM. _Must_ be 0 here.
3931 - CONFIG_SYS_MBIO_BASE:
3932 Physical start address of Motherboard I/O (if using a
3935 - CONFIG_SYS_FLASH_BASE:
3936 Physical start address of Flash memory.
3938 - CONFIG_SYS_MONITOR_BASE:
3939 Physical start address of boot monitor code (set by
3940 make config files to be same as the text base address
3941 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3942 CONFIG_SYS_FLASH_BASE when booting from flash.
3944 - CONFIG_SYS_MONITOR_LEN:
3945 Size of memory reserved for monitor code, used to
3946 determine _at_compile_time_ (!) if the environment is
3947 embedded within the U-Boot image, or in a separate
3950 - CONFIG_SYS_MALLOC_LEN:
3951 Size of DRAM reserved for malloc() use.
3953 - CONFIG_SYS_MALLOC_F_LEN
3954 Size of the malloc() pool for use before relocation. If
3955 this is defined, then a very simple malloc() implementation
3956 will become available before relocation. The address is just
3957 below the global data, and the stack is moved down to make
3960 This feature allocates regions with increasing addresses
3961 within the region. calloc() is supported, but realloc()
3962 is not available. free() is supported but does nothing.
3963 The memory will be freed (or in fact just forgotten) when
3964 U-Boot relocates itself.
3966 Pre-relocation malloc() is only supported on ARM and sandbox
3967 at present but is fairly easy to enable for other archs.
3969 - CONFIG_SYS_MALLOC_SIMPLE
3970 Provides a simple and small malloc() and calloc() for those
3971 boards which do not use the full malloc in SPL (which is
3972 enabled with CONFIG_SYS_SPL_MALLOC_START).
3974 - CONFIG_SYS_NONCACHED_MEMORY:
3975 Size of non-cached memory area. This area of memory will be
3976 typically located right below the malloc() area and mapped
3977 uncached in the MMU. This is useful for drivers that would
3978 otherwise require a lot of explicit cache maintenance. For
3979 some drivers it's also impossible to properly maintain the
3980 cache. For example if the regions that need to be flushed
3981 are not a multiple of the cache-line size, *and* padding
3982 cannot be allocated between the regions to align them (i.e.
3983 if the HW requires a contiguous array of regions, and the
3984 size of each region is not cache-aligned), then a flush of
3985 one region may result in overwriting data that hardware has
3986 written to another region in the same cache-line. This can
3987 happen for example in network drivers where descriptors for
3988 buffers are typically smaller than the CPU cache-line (e.g.
3989 16 bytes vs. 32 or 64 bytes).
3991 Non-cached memory is only supported on 32-bit ARM at present.
3993 - CONFIG_SYS_BOOTM_LEN:
3994 Normally compressed uImages are limited to an
3995 uncompressed size of 8 MBytes. If this is not enough,
3996 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3997 to adjust this setting to your needs.
3999 - CONFIG_SYS_BOOTMAPSZ:
4000 Maximum size of memory mapped by the startup code of
4001 the Linux kernel; all data that must be processed by
4002 the Linux kernel (bd_info, boot arguments, FDT blob if
4003 used) must be put below this limit, unless "bootm_low"
4004 environment variable is defined and non-zero. In such case
4005 all data for the Linux kernel must be between "bootm_low"
4006 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4007 variable "bootm_mapsize" will override the value of
4008 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4009 then the value in "bootm_size" will be used instead.
4011 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4012 Enable initrd_high functionality. If defined then the
4013 initrd_high feature is enabled and the bootm ramdisk subcommand
4016 - CONFIG_SYS_BOOT_GET_CMDLINE:
4017 Enables allocating and saving kernel cmdline in space between
4018 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4020 - CONFIG_SYS_BOOT_GET_KBD:
4021 Enables allocating and saving a kernel copy of the bd_info in
4022 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4024 - CONFIG_SYS_MAX_FLASH_BANKS:
4025 Max number of Flash memory banks
4027 - CONFIG_SYS_MAX_FLASH_SECT:
4028 Max number of sectors on a Flash chip
4030 - CONFIG_SYS_FLASH_ERASE_TOUT:
4031 Timeout for Flash erase operations (in ms)
4033 - CONFIG_SYS_FLASH_WRITE_TOUT:
4034 Timeout for Flash write operations (in ms)
4036 - CONFIG_SYS_FLASH_LOCK_TOUT
4037 Timeout for Flash set sector lock bit operation (in ms)
4039 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4040 Timeout for Flash clear lock bits operation (in ms)
4042 - CONFIG_SYS_FLASH_PROTECTION
4043 If defined, hardware flash sectors protection is used
4044 instead of U-Boot software protection.
4046 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4048 Enable TFTP transfers directly to flash memory;
4049 without this option such a download has to be
4050 performed in two steps: (1) download to RAM, and (2)
4051 copy from RAM to flash.
4053 The two-step approach is usually more reliable, since
4054 you can check if the download worked before you erase
4055 the flash, but in some situations (when system RAM is
4056 too limited to allow for a temporary copy of the
4057 downloaded image) this option may be very useful.
4059 - CONFIG_SYS_FLASH_CFI:
4060 Define if the flash driver uses extra elements in the
4061 common flash structure for storing flash geometry.
4063 - CONFIG_FLASH_CFI_DRIVER
4064 This option also enables the building of the cfi_flash driver
4065 in the drivers directory
4067 - CONFIG_FLASH_CFI_MTD
4068 This option enables the building of the cfi_mtd driver
4069 in the drivers directory. The driver exports CFI flash
4072 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4073 Use buffered writes to flash.
4075 - CONFIG_FLASH_SPANSION_S29WS_N
4076 s29ws-n MirrorBit flash has non-standard addresses for buffered
4079 - CONFIG_SYS_FLASH_QUIET_TEST
4080 If this option is defined, the common CFI flash doesn't
4081 print it's warning upon not recognized FLASH banks. This
4082 is useful, if some of the configured banks are only
4083 optionally available.
4085 - CONFIG_FLASH_SHOW_PROGRESS
4086 If defined (must be an integer), print out countdown
4087 digits and dots. Recommended value: 45 (9..1) for 80
4088 column displays, 15 (3..1) for 40 column displays.
4090 - CONFIG_FLASH_VERIFY
4091 If defined, the content of the flash (destination) is compared
4092 against the source after the write operation. An error message
4093 will be printed when the contents are not identical.
4094 Please note that this option is useless in nearly all cases,
4095 since such flash programming errors usually are detected earlier
4096 while unprotecting/erasing/programming. Please only enable
4097 this option if you really know what you are doing.
4099 - CONFIG_SYS_RX_ETH_BUFFER:
4100 Defines the number of Ethernet receive buffers. On some
4101 Ethernet controllers it is recommended to set this value
4102 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4103 buffers can be full shortly after enabling the interface
4104 on high Ethernet traffic.
4105 Defaults to 4 if not defined.
4107 - CONFIG_ENV_MAX_ENTRIES
4109 Maximum number of entries in the hash table that is used
4110 internally to store the environment settings. The default
4111 setting is supposed to be generous and should work in most
4112 cases. This setting can be used to tune behaviour; see
4113 lib/hashtable.c for details.
4115 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4116 - CONFIG_ENV_FLAGS_LIST_STATIC
4117 Enable validation of the values given to environment variables when
4118 calling env set. Variables can be restricted to only decimal,
4119 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4120 the variables can also be restricted to IP address or MAC address.
4122 The format of the list is:
4123 type_attribute = [s|d|x|b|i|m]
4124 access_attribute = [a|r|o|c]
4125 attributes = type_attribute[access_attribute]
4126 entry = variable_name[:attributes]
4129 The type attributes are:
4130 s - String (default)
4133 b - Boolean ([1yYtT|0nNfF])
4137 The access attributes are:
4143 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4144 Define this to a list (string) to define the ".flags"
4145 environment variable in the default or embedded environment.
4147 - CONFIG_ENV_FLAGS_LIST_STATIC
4148 Define this to a list (string) to define validation that
4149 should be done if an entry is not found in the ".flags"
4150 environment variable. To override a setting in the static
4151 list, simply add an entry for the same variable name to the
4154 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4155 If defined, don't allow the -f switch to env set override variable
4158 - CONFIG_SYS_GENERIC_BOARD
4159 This selects the architecture-generic board system instead of the
4160 architecture-specific board files. It is intended to move boards
4161 to this new framework over time. Defining this will disable the
4162 arch/foo/lib/board.c file and use common/board_f.c and
4163 common/board_r.c instead. To use this option your architecture
4164 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4165 If you find problems enabling this option on your board please report
4166 the problem and send patches!
4168 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4169 This is set by OMAP boards for the max time that reset should
4170 be asserted. See doc/README.omap-reset-time for details on how
4171 the value can be calculated on a given board.
4174 If stdint.h is available with your toolchain you can define this
4175 option to enable it. You can provide option 'USE_STDINT=1' when
4176 building U-Boot to enable this.
4178 The following definitions that deal with the placement and management
4179 of environment data (variable area); in general, we support the
4180 following configurations:
4182 - CONFIG_BUILD_ENVCRC:
4184 Builds up envcrc with the target environment so that external utils
4185 may easily extract it and embed it in final U-Boot images.
4187 - CONFIG_ENV_IS_IN_FLASH:
4189 Define this if the environment is in flash memory.
4191 a) The environment occupies one whole flash sector, which is
4192 "embedded" in the text segment with the U-Boot code. This
4193 happens usually with "bottom boot sector" or "top boot
4194 sector" type flash chips, which have several smaller
4195 sectors at the start or the end. For instance, such a
4196 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4197 such a case you would place the environment in one of the
4198 4 kB sectors - with U-Boot code before and after it. With
4199 "top boot sector" type flash chips, you would put the
4200 environment in one of the last sectors, leaving a gap
4201 between U-Boot and the environment.
4203 - CONFIG_ENV_OFFSET:
4205 Offset of environment data (variable area) to the
4206 beginning of flash memory; for instance, with bottom boot
4207 type flash chips the second sector can be used: the offset
4208 for this sector is given here.
4210 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4214 This is just another way to specify the start address of
4215 the flash sector containing the environment (instead of
4218 - CONFIG_ENV_SECT_SIZE:
4220 Size of the sector containing the environment.
4223 b) Sometimes flash chips have few, equal sized, BIG sectors.
4224 In such a case you don't want to spend a whole sector for
4229 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4230 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4231 of this flash sector for the environment. This saves
4232 memory for the RAM copy of the environment.
4234 It may also save flash memory if you decide to use this
4235 when your environment is "embedded" within U-Boot code,
4236 since then the remainder of the flash sector could be used
4237 for U-Boot code. It should be pointed out that this is
4238 STRONGLY DISCOURAGED from a robustness point of view:
4239 updating the environment in flash makes it always
4240 necessary to erase the WHOLE sector. If something goes
4241 wrong before the contents has been restored from a copy in
4242 RAM, your target system will be dead.
4244 - CONFIG_ENV_ADDR_REDUND
4245 CONFIG_ENV_SIZE_REDUND
4247 These settings describe a second storage area used to hold
4248 a redundant copy of the environment data, so that there is
4249 a valid backup copy in case there is a power failure during
4250 a "saveenv" operation.
4252 BE CAREFUL! Any changes to the flash layout, and some changes to the
4253 source code will make it necessary to adapt <board>/u-boot.lds*
4257 - CONFIG_ENV_IS_IN_NVRAM:
4259 Define this if you have some non-volatile memory device
4260 (NVRAM, battery buffered SRAM) which you want to use for the
4266 These two #defines are used to determine the memory area you
4267 want to use for environment. It is assumed that this memory
4268 can just be read and written to, without any special
4271 BE CAREFUL! The first access to the environment happens quite early
4272 in U-Boot initialization (when we try to get the setting of for the
4273 console baudrate). You *MUST* have mapped your NVRAM area then, or
4276 Please note that even with NVRAM we still use a copy of the
4277 environment in RAM: we could work on NVRAM directly, but we want to
4278 keep settings there always unmodified except somebody uses "saveenv"
4279 to save the current settings.
4282 - CONFIG_ENV_IS_IN_EEPROM:
4284 Use this if you have an EEPROM or similar serial access
4285 device and a driver for it.
4287 - CONFIG_ENV_OFFSET:
4290 These two #defines specify the offset and size of the
4291 environment area within the total memory of your EEPROM.
4293 - CONFIG_SYS_I2C_EEPROM_ADDR:
4294 If defined, specified the chip address of the EEPROM device.
4295 The default address is zero.
4297 - CONFIG_SYS_I2C_EEPROM_BUS:
4298 If defined, specified the i2c bus of the EEPROM device.
4300 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4301 If defined, the number of bits used to address bytes in a
4302 single page in the EEPROM device. A 64 byte page, for example
4303 would require six bits.
4305 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4306 If defined, the number of milliseconds to delay between
4307 page writes. The default is zero milliseconds.
4309 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4310 The length in bytes of the EEPROM memory array address. Note
4311 that this is NOT the chip address length!
4313 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4314 EEPROM chips that implement "address overflow" are ones
4315 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4316 address and the extra bits end up in the "chip address" bit
4317 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4320 Note that we consider the length of the address field to
4321 still be one byte because the extra address bits are hidden
4322 in the chip address.
4324 - CONFIG_SYS_EEPROM_SIZE:
4325 The size in bytes of the EEPROM device.
4327 - CONFIG_ENV_EEPROM_IS_ON_I2C
4328 define this, if you have I2C and SPI activated, and your
4329 EEPROM, which holds the environment, is on the I2C bus.
4331 - CONFIG_I2C_ENV_EEPROM_BUS
4332 if you have an Environment on an EEPROM reached over
4333 I2C muxes, you can define here, how to reach this
4334 EEPROM. For example:
4336 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4338 EEPROM which holds the environment, is reached over
4339 a pca9547 i2c mux with address 0x70, channel 3.
4341 - CONFIG_ENV_IS_IN_DATAFLASH:
4343 Define this if you have a DataFlash memory device which you
4344 want to use for the environment.
4346 - CONFIG_ENV_OFFSET:
4350 These three #defines specify the offset and size of the
4351 environment area within the total memory of your DataFlash placed
4352 at the specified address.
4354 - CONFIG_ENV_IS_IN_SPI_FLASH:
4356 Define this if you have a SPI Flash memory device which you
4357 want to use for the environment.
4359 - CONFIG_ENV_OFFSET:
4362 These two #defines specify the offset and size of the
4363 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4364 aligned to an erase sector boundary.
4366 - CONFIG_ENV_SECT_SIZE:
4368 Define the SPI flash's sector size.
4370 - CONFIG_ENV_OFFSET_REDUND (optional):
4372 This setting describes a second storage area of CONFIG_ENV_SIZE
4373 size used to hold a redundant copy of the environment data, so
4374 that there is a valid backup copy in case there is a power failure
4375 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4376 aligned to an erase sector boundary.
4378 - CONFIG_ENV_SPI_BUS (optional):
4379 - CONFIG_ENV_SPI_CS (optional):
4381 Define the SPI bus and chip select. If not defined they will be 0.
4383 - CONFIG_ENV_SPI_MAX_HZ (optional):
4385 Define the SPI max work clock. If not defined then use 1MHz.
4387 - CONFIG_ENV_SPI_MODE (optional):
4389 Define the SPI work mode. If not defined then use SPI_MODE_3.
4391 - CONFIG_ENV_IS_IN_REMOTE:
4393 Define this if you have a remote memory space which you
4394 want to use for the local device's environment.
4399 These two #defines specify the address and size of the
4400 environment area within the remote memory space. The
4401 local device can get the environment from remote memory
4402 space by SRIO or PCIE links.
4404 BE CAREFUL! For some special cases, the local device can not use
4405 "saveenv" command. For example, the local device will get the
4406 environment stored in a remote NOR flash by SRIO or PCIE link,
4407 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4409 - CONFIG_ENV_IS_IN_NAND:
4411 Define this if you have a NAND device which you want to use
4412 for the environment.
4414 - CONFIG_ENV_OFFSET:
4417 These two #defines specify the offset and size of the environment
4418 area within the first NAND device. CONFIG_ENV_OFFSET must be
4419 aligned to an erase block boundary.
4421 - CONFIG_ENV_OFFSET_REDUND (optional):
4423 This setting describes a second storage area of CONFIG_ENV_SIZE
4424 size used to hold a redundant copy of the environment data, so
4425 that there is a valid backup copy in case there is a power failure
4426 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4427 aligned to an erase block boundary.
4429 - CONFIG_ENV_RANGE (optional):
4431 Specifies the length of the region in which the environment
4432 can be written. This should be a multiple of the NAND device's
4433 block size. Specifying a range with more erase blocks than
4434 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4435 the range to be avoided.
4437 - CONFIG_ENV_OFFSET_OOB (optional):
4439 Enables support for dynamically retrieving the offset of the
4440 environment from block zero's out-of-band data. The
4441 "nand env.oob" command can be used to record this offset.
4442 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4443 using CONFIG_ENV_OFFSET_OOB.
4445 - CONFIG_NAND_ENV_DST
4447 Defines address in RAM to which the nand_spl code should copy the
4448 environment. If redundant environment is used, it will be copied to
4449 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4451 - CONFIG_ENV_IS_IN_UBI:
4453 Define this if you have an UBI volume that you want to use for the
4454 environment. This has the benefit of wear-leveling the environment
4455 accesses, which is important on NAND.
4457 - CONFIG_ENV_UBI_PART:
4459 Define this to a string that is the mtd partition containing the UBI.
4461 - CONFIG_ENV_UBI_VOLUME:
4463 Define this to the name of the volume that you want to store the
4466 - CONFIG_ENV_UBI_VOLUME_REDUND:
4468 Define this to the name of another volume to store a second copy of
4469 the environment in. This will enable redundant environments in UBI.
4470 It is assumed that both volumes are in the same MTD partition.
4472 - CONFIG_UBI_SILENCE_MSG
4473 - CONFIG_UBIFS_SILENCE_MSG
4475 You will probably want to define these to avoid a really noisy system
4476 when storing the env in UBI.
4478 - CONFIG_ENV_IS_IN_FAT:
4479 Define this if you want to use the FAT file system for the environment.
4481 - FAT_ENV_INTERFACE:
4483 Define this to a string that is the name of the block device.
4485 - FAT_ENV_DEV_AND_PART:
4487 Define this to a string to specify the partition of the device. It can
4490 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4491 - "D:P": device D partition P. Error occurs if device D has no
4494 - "D" or "D:": device D partition 1 if device D has partition
4495 table, or the whole device D if has no partition
4497 - "D:auto": first partition in device D with bootable flag set.
4498 If none, first valid partition in device D. If no
4499 partition table then means device D.
4503 It's a string of the FAT file name. This file use to store the
4507 This should be defined. Otherwise it cannot save the environment file.
4509 - CONFIG_ENV_IS_IN_MMC:
4511 Define this if you have an MMC device which you want to use for the
4514 - CONFIG_SYS_MMC_ENV_DEV:
4516 Specifies which MMC device the environment is stored in.
4518 - CONFIG_SYS_MMC_ENV_PART (optional):
4520 Specifies which MMC partition the environment is stored in. If not
4521 set, defaults to partition 0, the user area. Common values might be
4522 1 (first MMC boot partition), 2 (second MMC boot partition).
4524 - CONFIG_ENV_OFFSET:
4527 These two #defines specify the offset and size of the environment
4528 area within the specified MMC device.
4530 If offset is positive (the usual case), it is treated as relative to
4531 the start of the MMC partition. If offset is negative, it is treated
4532 as relative to the end of the MMC partition. This can be useful if
4533 your board may be fitted with different MMC devices, which have
4534 different sizes for the MMC partitions, and you always want the
4535 environment placed at the very end of the partition, to leave the
4536 maximum possible space before it, to store other data.
4538 These two values are in units of bytes, but must be aligned to an
4539 MMC sector boundary.
4541 - CONFIG_ENV_OFFSET_REDUND (optional):
4543 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4544 hold a redundant copy of the environment data. This provides a
4545 valid backup copy in case the other copy is corrupted, e.g. due
4546 to a power failure during a "saveenv" operation.
4548 This value may also be positive or negative; this is handled in the
4549 same way as CONFIG_ENV_OFFSET.
4551 This value is also in units of bytes, but must also be aligned to
4552 an MMC sector boundary.
4554 - CONFIG_ENV_SIZE_REDUND (optional):
4556 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4557 set. If this value is set, it must be set to the same value as
4560 - CONFIG_SYS_SPI_INIT_OFFSET
4562 Defines offset to the initial SPI buffer area in DPRAM. The
4563 area is used at an early stage (ROM part) if the environment
4564 is configured to reside in the SPI EEPROM: We need a 520 byte
4565 scratch DPRAM area. It is used between the two initialization
4566 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4567 to be a good choice since it makes it far enough from the
4568 start of the data area as well as from the stack pointer.
4570 Please note that the environment is read-only until the monitor
4571 has been relocated to RAM and a RAM copy of the environment has been
4572 created; also, when using EEPROM you will have to use getenv_f()
4573 until then to read environment variables.
4575 The environment is protected by a CRC32 checksum. Before the monitor
4576 is relocated into RAM, as a result of a bad CRC you will be working
4577 with the compiled-in default environment - *silently*!!! [This is
4578 necessary, because the first environment variable we need is the
4579 "baudrate" setting for the console - if we have a bad CRC, we don't
4580 have any device yet where we could complain.]
4582 Note: once the monitor has been relocated, then it will complain if
4583 the default environment is used; a new CRC is computed as soon as you
4584 use the "saveenv" command to store a valid environment.
4586 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4587 Echo the inverted Ethernet link state to the fault LED.
4589 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4590 also needs to be defined.
4592 - CONFIG_SYS_FAULT_MII_ADDR:
4593 MII address of the PHY to check for the Ethernet link state.
4595 - CONFIG_NS16550_MIN_FUNCTIONS:
4596 Define this if you desire to only have use of the NS16550_init
4597 and NS16550_putc functions for the serial driver located at
4598 drivers/serial/ns16550.c. This option is useful for saving
4599 space for already greatly restricted images, including but not
4600 limited to NAND_SPL configurations.
4602 - CONFIG_DISPLAY_BOARDINFO
4603 Display information about the board that U-Boot is running on
4604 when U-Boot starts up. The board function checkboard() is called
4607 - CONFIG_DISPLAY_BOARDINFO_LATE
4608 Similar to the previous option, but display this information
4609 later, once stdio is running and output goes to the LCD, if
4612 - CONFIG_BOARD_SIZE_LIMIT:
4613 Maximum size of the U-Boot image. When defined, the
4614 build system checks that the actual size does not
4617 Low Level (hardware related) configuration options:
4618 ---------------------------------------------------
4620 - CONFIG_SYS_CACHELINE_SIZE:
4621 Cache Line Size of the CPU.
4623 - CONFIG_SYS_DEFAULT_IMMR:
4624 Default address of the IMMR after system reset.
4626 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4627 and RPXsuper) to be able to adjust the position of
4628 the IMMR register after a reset.
4630 - CONFIG_SYS_CCSRBAR_DEFAULT:
4631 Default (power-on reset) physical address of CCSR on Freescale
4634 - CONFIG_SYS_CCSRBAR:
4635 Virtual address of CCSR. On a 32-bit build, this is typically
4636 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4638 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4639 for cross-platform code that uses that macro instead.
4641 - CONFIG_SYS_CCSRBAR_PHYS:
4642 Physical address of CCSR. CCSR can be relocated to a new
4643 physical address, if desired. In this case, this macro should
4644 be set to that address. Otherwise, it should be set to the
4645 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4646 is typically relocated on 36-bit builds. It is recommended
4647 that this macro be defined via the _HIGH and _LOW macros:
4649 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4650 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4652 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4653 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4654 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4655 used in assembly code, so it must not contain typecasts or
4656 integer size suffixes (e.g. "ULL").
4658 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4659 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4660 used in assembly code, so it must not contain typecasts or
4661 integer size suffixes (e.g. "ULL").
4663 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4664 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4665 forced to a value that ensures that CCSR is not relocated.
4667 - Floppy Disk Support:
4668 CONFIG_SYS_FDC_DRIVE_NUMBER
4670 the default drive number (default value 0)
4672 CONFIG_SYS_ISA_IO_STRIDE
4674 defines the spacing between FDC chipset registers
4677 CONFIG_SYS_ISA_IO_OFFSET
4679 defines the offset of register from address. It
4680 depends on which part of the data bus is connected to
4681 the FDC chipset. (default value 0)
4683 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4684 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4687 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4688 fdc_hw_init() is called at the beginning of the FDC
4689 setup. fdc_hw_init() must be provided by the board
4690 source code. It is used to make hardware-dependent
4694 Most IDE controllers were designed to be connected with PCI
4695 interface. Only few of them were designed for AHB interface.
4696 When software is doing ATA command and data transfer to
4697 IDE devices through IDE-AHB controller, some additional
4698 registers accessing to these kind of IDE-AHB controller
4701 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4702 DO NOT CHANGE unless you know exactly what you're
4703 doing! (11-4) [MPC8xx/82xx systems only]
4705 - CONFIG_SYS_INIT_RAM_ADDR:
4707 Start address of memory area that can be used for
4708 initial data and stack; please note that this must be
4709 writable memory that is working WITHOUT special
4710 initialization, i. e. you CANNOT use normal RAM which
4711 will become available only after programming the
4712 memory controller and running certain initialization
4715 U-Boot uses the following memory types:
4716 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4717 - MPC824X: data cache
4718 - PPC4xx: data cache
4720 - CONFIG_SYS_GBL_DATA_OFFSET:
4722 Offset of the initial data structure in the memory
4723 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4724 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4725 data is located at the end of the available space
4726 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4727 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4728 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4729 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4732 On the MPC824X (or other systems that use the data
4733 cache for initial memory) the address chosen for
4734 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4735 point to an otherwise UNUSED address space between
4736 the top of RAM and the start of the PCI space.
4738 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4740 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4742 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4744 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4746 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4748 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4750 - CONFIG_SYS_OR_TIMING_SDRAM:
4753 - CONFIG_SYS_MAMR_PTA:
4754 periodic timer for refresh
4756 - CONFIG_SYS_DER: Debug Event Register (37-47)
4758 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4759 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4760 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4761 CONFIG_SYS_BR1_PRELIM:
4762 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4764 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4765 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4766 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4767 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4769 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4770 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4771 Machine Mode Register and Memory Periodic Timer
4772 Prescaler definitions (SDRAM timing)
4774 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4775 enable I2C microcode relocation patch (MPC8xx);
4776 define relocation offset in DPRAM [DSP2]
4778 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4779 enable SMC microcode relocation patch (MPC8xx);
4780 define relocation offset in DPRAM [SMC1]
4782 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4783 enable SPI microcode relocation patch (MPC8xx);
4784 define relocation offset in DPRAM [SCC4]
4786 - CONFIG_SYS_USE_OSCCLK:
4787 Use OSCM clock mode on MBX8xx board. Be careful,
4788 wrong setting might damage your board. Read
4789 doc/README.MBX before setting this variable!
4791 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4792 Offset of the bootmode word in DPRAM used by post
4793 (Power On Self Tests). This definition overrides
4794 #define'd default value in commproc.h resp.
4797 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4798 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4799 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4800 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4801 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4802 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4803 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4804 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4805 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4807 - CONFIG_PCI_DISABLE_PCIE:
4808 Disable PCI-Express on systems where it is supported but not
4811 - CONFIG_PCI_ENUM_ONLY
4812 Only scan through and get the devices on the buses.
4813 Don't do any setup work, presumably because someone or
4814 something has already done it, and we don't need to do it
4815 a second time. Useful for platforms that are pre-booted
4816 by coreboot or similar.
4818 - CONFIG_PCI_INDIRECT_BRIDGE:
4819 Enable support for indirect PCI bridges.
4822 Chip has SRIO or not
4825 Board has SRIO 1 port available
4828 Board has SRIO 2 port available
4830 - CONFIG_SRIO_PCIE_BOOT_MASTER
4831 Board can support master function for Boot from SRIO and PCIE
4833 - CONFIG_SYS_SRIOn_MEM_VIRT:
4834 Virtual Address of SRIO port 'n' memory region
4836 - CONFIG_SYS_SRIOn_MEM_PHYS:
4837 Physical Address of SRIO port 'n' memory region
4839 - CONFIG_SYS_SRIOn_MEM_SIZE:
4840 Size of SRIO port 'n' memory region
4842 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4843 Defined to tell the NAND controller that the NAND chip is using
4845 Not all NAND drivers use this symbol.
4846 Example of drivers that use it:
4847 - drivers/mtd/nand/ndfc.c
4848 - drivers/mtd/nand/mxc_nand.c
4850 - CONFIG_SYS_NDFC_EBC0_CFG
4851 Sets the EBC0_CFG register for the NDFC. If not defined
4852 a default value will be used.
4855 Get DDR timing information from an I2C EEPROM. Common
4856 with pluggable memory modules such as SODIMMs
4859 I2C address of the SPD EEPROM
4861 - CONFIG_SYS_SPD_BUS_NUM
4862 If SPD EEPROM is on an I2C bus other than the first
4863 one, specify here. Note that the value must resolve
4864 to something your driver can deal with.
4866 - CONFIG_SYS_DDR_RAW_TIMING
4867 Get DDR timing information from other than SPD. Common with
4868 soldered DDR chips onboard without SPD. DDR raw timing
4869 parameters are extracted from datasheet and hard-coded into
4870 header files or board specific files.
4872 - CONFIG_FSL_DDR_INTERACTIVE
4873 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4875 - CONFIG_FSL_DDR_SYNC_REFRESH
4876 Enable sync of refresh for multiple controllers.
4878 - CONFIG_FSL_DDR_BIST
4879 Enable built-in memory test for Freescale DDR controllers.
4881 - CONFIG_SYS_83XX_DDR_USES_CS0
4882 Only for 83xx systems. If specified, then DDR should
4883 be configured using CS0 and CS1 instead of CS2 and CS3.
4885 - CONFIG_ETHER_ON_FEC[12]
4886 Define to enable FEC[12] on a 8xx series processor.
4888 - CONFIG_FEC[12]_PHY
4889 Define to the hardcoded PHY address which corresponds
4890 to the given FEC; i. e.
4891 #define CONFIG_FEC1_PHY 4
4892 means that the PHY with address 4 is connected to FEC1
4894 When set to -1, means to probe for first available.
4896 - CONFIG_FEC[12]_PHY_NORXERR
4897 The PHY does not have a RXERR line (RMII only).
4898 (so program the FEC to ignore it).
4901 Enable RMII mode for all FECs.
4902 Note that this is a global option, we can't
4903 have one FEC in standard MII mode and another in RMII mode.
4905 - CONFIG_CRC32_VERIFY
4906 Add a verify option to the crc32 command.
4909 => crc32 -v <address> <count> <crc32>
4911 Where address/count indicate a memory area
4912 and crc32 is the correct crc32 which the
4916 Add the "loopw" memory command. This only takes effect if
4917 the memory commands are activated globally (CONFIG_CMD_MEM).
4920 Add the "mdc" and "mwc" memory commands. These are cyclic
4925 This command will print 4 bytes (10,11,12,13) each 500 ms.
4927 => mwc.l 100 12345678 10
4928 This command will write 12345678 to address 100 all 10 ms.
4930 This only takes effect if the memory commands are activated
4931 globally (CONFIG_CMD_MEM).
4933 - CONFIG_SKIP_LOWLEVEL_INIT
4934 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4935 low level initializations (like setting up the memory
4936 controller) are omitted and/or U-Boot does not
4937 relocate itself into RAM.
4939 Normally this variable MUST NOT be defined. The only
4940 exception is when U-Boot is loaded (to RAM) by some
4941 other boot loader or by a debugger which performs
4942 these initializations itself.
4945 Modifies the behaviour of start.S when compiling a loader
4946 that is executed before the actual U-Boot. E.g. when
4947 compiling a NAND SPL.
4950 Modifies the behaviour of start.S when compiling a loader
4951 that is executed after the SPL and before the actual U-Boot.
4952 It is loaded by the SPL.
4954 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4955 Only for 85xx systems. If this variable is specified, the section
4956 .resetvec is not kept and the section .bootpg is placed in the
4957 previous 4k of the .text section.
4959 - CONFIG_ARCH_MAP_SYSMEM
4960 Generally U-Boot (and in particular the md command) uses
4961 effective address. It is therefore not necessary to regard
4962 U-Boot address as virtual addresses that need to be translated
4963 to physical addresses. However, sandbox requires this, since
4964 it maintains its own little RAM buffer which contains all
4965 addressable memory. This option causes some memory accesses
4966 to be mapped through map_sysmem() / unmap_sysmem().
4968 - CONFIG_USE_ARCH_MEMCPY
4969 CONFIG_USE_ARCH_MEMSET
4970 If these options are used a optimized version of memcpy/memset will
4971 be used if available. These functions may be faster under some
4972 conditions but may increase the binary size.
4974 - CONFIG_X86_RESET_VECTOR
4975 If defined, the x86 reset vector code is included. This is not
4976 needed when U-Boot is running from Coreboot.
4979 Defines the MPU clock speed (in MHz).
4981 NOTE : currently only supported on AM335x platforms.
4983 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4984 Enables the RTC32K OSC on AM33xx based plattforms
4986 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4987 Option to disable subpage write in NAND driver
4988 driver that uses this:
4989 drivers/mtd/nand/davinci_nand.c
4991 Freescale QE/FMAN Firmware Support:
4992 -----------------------------------
4994 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4995 loading of "firmware", which is encoded in the QE firmware binary format.
4996 This firmware often needs to be loaded during U-Boot booting, so macros
4997 are used to identify the storage device (NOR flash, SPI, etc) and the address
5000 - CONFIG_SYS_FMAN_FW_ADDR
5001 The address in the storage device where the FMAN microcode is located. The
5002 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5005 - CONFIG_SYS_QE_FW_ADDR
5006 The address in the storage device where the QE microcode is located. The
5007 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5010 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5011 The maximum possible size of the firmware. The firmware binary format
5012 has a field that specifies the actual size of the firmware, but it
5013 might not be possible to read any part of the firmware unless some
5014 local storage is allocated to hold the entire firmware first.
5016 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5017 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5018 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5019 virtual address in NOR flash.
5021 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5022 Specifies that QE/FMAN firmware is located in NAND flash.
5023 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5025 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5026 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5027 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5029 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5030 Specifies that QE/FMAN firmware is located on the primary SPI
5031 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5033 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5034 Specifies that QE/FMAN firmware is located in the remote (master)
5035 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5036 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5037 window->master inbound window->master LAW->the ucode address in
5038 master's memory space.
5040 Freescale Layerscape Management Complex Firmware Support:
5041 ---------------------------------------------------------
5042 The Freescale Layerscape Management Complex (MC) supports the loading of
5044 This firmware often needs to be loaded during U-Boot booting, so macros
5045 are used to identify the storage device (NOR flash, SPI, etc) and the address
5048 - CONFIG_FSL_MC_ENET
5049 Enable the MC driver for Layerscape SoCs.
5051 - CONFIG_SYS_LS_MC_FW_ADDR
5052 The address in the storage device where the firmware is located. The
5053 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5056 - CONFIG_SYS_LS_MC_FW_LENGTH
5057 The maximum possible size of the firmware. The firmware binary format
5058 has a field that specifies the actual size of the firmware, but it
5059 might not be possible to read any part of the firmware unless some
5060 local storage is allocated to hold the entire firmware first.
5062 - CONFIG_SYS_LS_MC_FW_IN_NOR
5063 Specifies that MC firmware is located in NOR flash, mapped as
5064 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5065 virtual address in NOR flash.
5067 Building the Software:
5068 ======================
5070 Building U-Boot has been tested in several native build environments
5071 and in many different cross environments. Of course we cannot support
5072 all possibly existing versions of cross development tools in all
5073 (potentially obsolete) versions. In case of tool chain problems we
5074 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5075 which is extensively used to build and test U-Boot.
5077 If you are not using a native environment, it is assumed that you
5078 have GNU cross compiling tools available in your path. In this case,
5079 you must set the environment variable CROSS_COMPILE in your shell.
5080 Note that no changes to the Makefile or any other source files are
5081 necessary. For example using the ELDK on a 4xx CPU, please enter:
5083 $ CROSS_COMPILE=ppc_4xx-
5084 $ export CROSS_COMPILE
5086 Note: If you wish to generate Windows versions of the utilities in
5087 the tools directory you can use the MinGW toolchain
5088 (http://www.mingw.org). Set your HOST tools to the MinGW
5089 toolchain and execute 'make tools'. For example:
5091 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5093 Binaries such as tools/mkimage.exe will be created which can
5094 be executed on computers running Windows.
5096 U-Boot is intended to be simple to build. After installing the
5097 sources you must configure U-Boot for one specific board type. This
5102 where "NAME_defconfig" is the name of one of the existing configu-
5103 rations; see boards.cfg for supported names.
5105 Note: for some board special configuration names may exist; check if
5106 additional information is available from the board vendor; for
5107 instance, the TQM823L systems are available without (standard)
5108 or with LCD support. You can select such additional "features"
5109 when choosing the configuration, i. e.
5111 make TQM823L_defconfig
5112 - will configure for a plain TQM823L, i. e. no LCD support
5114 make TQM823L_LCD_defconfig
5115 - will configure for a TQM823L with U-Boot console on LCD
5120 Finally, type "make all", and you should get some working U-Boot
5121 images ready for download to / installation on your system:
5123 - "u-boot.bin" is a raw binary image
5124 - "u-boot" is an image in ELF binary format
5125 - "u-boot.srec" is in Motorola S-Record format
5127 By default the build is performed locally and the objects are saved
5128 in the source directory. One of the two methods can be used to change
5129 this behavior and build U-Boot to some external directory:
5131 1. Add O= to the make command line invocations:
5133 make O=/tmp/build distclean
5134 make O=/tmp/build NAME_defconfig
5135 make O=/tmp/build all
5137 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5139 export KBUILD_OUTPUT=/tmp/build
5144 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5148 Please be aware that the Makefiles assume you are using GNU make, so
5149 for instance on NetBSD you might need to use "gmake" instead of
5153 If the system board that you have is not listed, then you will need
5154 to port U-Boot to your hardware platform. To do this, follow these
5157 1. Add a new configuration option for your board to the toplevel
5158 "boards.cfg" file, using the existing entries as examples.
5159 Follow the instructions there to keep the boards in order.
5160 2. Create a new directory to hold your board specific code. Add any
5161 files you need. In your board directory, you will need at least
5162 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5163 3. Create a new configuration file "include/configs/<board>.h" for
5165 3. If you're porting U-Boot to a new CPU, then also create a new
5166 directory to hold your CPU specific code. Add any files you need.
5167 4. Run "make <board>_defconfig" with your new name.
5168 5. Type "make", and you should get a working "u-boot.srec" file
5169 to be installed on your target system.
5170 6. Debug and solve any problems that might arise.
5171 [Of course, this last step is much harder than it sounds.]
5174 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5175 ==============================================================
5177 If you have modified U-Boot sources (for instance added a new board
5178 or support for new devices, a new CPU, etc.) you are expected to
5179 provide feedback to the other developers. The feedback normally takes
5180 the form of a "patch", i. e. a context diff against a certain (latest
5181 official or latest in the git repository) version of U-Boot sources.
5183 But before you submit such a patch, please verify that your modifi-
5184 cation did not break existing code. At least make sure that *ALL* of
5185 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5186 just run the "MAKEALL" script, which will configure and build U-Boot
5187 for ALL supported system. Be warned, this will take a while. You can
5188 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5189 environment variable to the script, i. e. to use the ELDK cross tools
5192 CROSS_COMPILE=ppc_8xx- MAKEALL
5194 or to build on a native PowerPC system you can type
5196 CROSS_COMPILE=' ' MAKEALL
5198 When using the MAKEALL script, the default behaviour is to build
5199 U-Boot in the source directory. This location can be changed by
5200 setting the BUILD_DIR environment variable. Also, for each target
5201 built, the MAKEALL script saves two log files (<target>.ERR and
5202 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5203 location can be changed by setting the MAKEALL_LOGDIR environment
5204 variable. For example:
5206 export BUILD_DIR=/tmp/build
5207 export MAKEALL_LOGDIR=/tmp/log
5208 CROSS_COMPILE=ppc_8xx- MAKEALL
5210 With the above settings build objects are saved in the /tmp/build,
5211 log files are saved in the /tmp/log and the source tree remains clean
5212 during the whole build process.
5215 See also "U-Boot Porting Guide" below.
5218 Monitor Commands - Overview:
5219 ============================
5221 go - start application at address 'addr'
5222 run - run commands in an environment variable
5223 bootm - boot application image from memory
5224 bootp - boot image via network using BootP/TFTP protocol
5225 bootz - boot zImage from memory
5226 tftpboot- boot image via network using TFTP protocol
5227 and env variables "ipaddr" and "serverip"
5228 (and eventually "gatewayip")
5229 tftpput - upload a file via network using TFTP protocol
5230 rarpboot- boot image via network using RARP/TFTP protocol
5231 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5232 loads - load S-Record file over serial line
5233 loadb - load binary file over serial line (kermit mode)
5235 mm - memory modify (auto-incrementing)
5236 nm - memory modify (constant address)
5237 mw - memory write (fill)
5239 cmp - memory compare
5240 crc32 - checksum calculation
5241 i2c - I2C sub-system
5242 sspi - SPI utility commands
5243 base - print or set address offset
5244 printenv- print environment variables
5245 setenv - set environment variables
5246 saveenv - save environment variables to persistent storage
5247 protect - enable or disable FLASH write protection
5248 erase - erase FLASH memory
5249 flinfo - print FLASH memory information
5250 nand - NAND memory operations (see doc/README.nand)
5251 bdinfo - print Board Info structure
5252 iminfo - print header information for application image
5253 coninfo - print console devices and informations
5254 ide - IDE sub-system
5255 loop - infinite loop on address range
5256 loopw - infinite write loop on address range
5257 mtest - simple RAM test
5258 icache - enable or disable instruction cache
5259 dcache - enable or disable data cache
5260 reset - Perform RESET of the CPU
5261 echo - echo args to console
5262 version - print monitor version
5263 help - print online help
5264 ? - alias for 'help'
5267 Monitor Commands - Detailed Description:
5268 ========================================
5272 For now: just type "help <command>".
5275 Environment Variables:
5276 ======================
5278 U-Boot supports user configuration using Environment Variables which
5279 can be made persistent by saving to Flash memory.
5281 Environment Variables are set using "setenv", printed using
5282 "printenv", and saved to Flash using "saveenv". Using "setenv"
5283 without a value can be used to delete a variable from the
5284 environment. As long as you don't save the environment you are
5285 working with an in-memory copy. In case the Flash area containing the
5286 environment is erased by accident, a default environment is provided.
5288 Some configuration options can be set using Environment Variables.
5290 List of environment variables (most likely not complete):
5292 baudrate - see CONFIG_BAUDRATE
5294 bootdelay - see CONFIG_BOOTDELAY
5296 bootcmd - see CONFIG_BOOTCOMMAND
5298 bootargs - Boot arguments when booting an RTOS image
5300 bootfile - Name of the image to load with TFTP
5302 bootm_low - Memory range available for image processing in the bootm
5303 command can be restricted. This variable is given as
5304 a hexadecimal number and defines lowest address allowed
5305 for use by the bootm command. See also "bootm_size"
5306 environment variable. Address defined by "bootm_low" is
5307 also the base of the initial memory mapping for the Linux
5308 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5311 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5312 This variable is given as a hexadecimal number and it
5313 defines the size of the memory region starting at base
5314 address bootm_low that is accessible by the Linux kernel
5315 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5316 as the default value if it is defined, and bootm_size is
5319 bootm_size - Memory range available for image processing in the bootm
5320 command can be restricted. This variable is given as
5321 a hexadecimal number and defines the size of the region
5322 allowed for use by the bootm command. See also "bootm_low"
5323 environment variable.
5325 updatefile - Location of the software update file on a TFTP server, used
5326 by the automatic software update feature. Please refer to
5327 documentation in doc/README.update for more details.
5329 autoload - if set to "no" (any string beginning with 'n'),
5330 "bootp" will just load perform a lookup of the
5331 configuration from the BOOTP server, but not try to
5332 load any image using TFTP
5334 autostart - if set to "yes", an image loaded using the "bootp",
5335 "rarpboot", "tftpboot" or "diskboot" commands will
5336 be automatically started (by internally calling
5339 If set to "no", a standalone image passed to the
5340 "bootm" command will be copied to the load address
5341 (and eventually uncompressed), but NOT be started.
5342 This can be used to load and uncompress arbitrary
5345 fdt_high - if set this restricts the maximum address that the
5346 flattened device tree will be copied into upon boot.
5347 For example, if you have a system with 1 GB memory
5348 at physical address 0x10000000, while Linux kernel
5349 only recognizes the first 704 MB as low memory, you
5350 may need to set fdt_high as 0x3C000000 to have the
5351 device tree blob be copied to the maximum address
5352 of the 704 MB low memory, so that Linux kernel can
5353 access it during the boot procedure.
5355 If this is set to the special value 0xFFFFFFFF then
5356 the fdt will not be copied at all on boot. For this
5357 to work it must reside in writable memory, have
5358 sufficient padding on the end of it for u-boot to
5359 add the information it needs into it, and the memory
5360 must be accessible by the kernel.
5362 fdtcontroladdr- if set this is the address of the control flattened
5363 device tree used by U-Boot when CONFIG_OF_CONTROL is
5366 i2cfast - (PPC405GP|PPC405EP only)
5367 if set to 'y' configures Linux I2C driver for fast
5368 mode (400kHZ). This environment variable is used in
5369 initialization code. So, for changes to be effective
5370 it must be saved and board must be reset.
5372 initrd_high - restrict positioning of initrd images:
5373 If this variable is not set, initrd images will be
5374 copied to the highest possible address in RAM; this
5375 is usually what you want since it allows for
5376 maximum initrd size. If for some reason you want to
5377 make sure that the initrd image is loaded below the
5378 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5379 variable to a value of "no" or "off" or "0".
5380 Alternatively, you can set it to a maximum upper
5381 address to use (U-Boot will still check that it
5382 does not overwrite the U-Boot stack and data).
5384 For instance, when you have a system with 16 MB
5385 RAM, and want to reserve 4 MB from use by Linux,
5386 you can do this by adding "mem=12M" to the value of
5387 the "bootargs" variable. However, now you must make
5388 sure that the initrd image is placed in the first
5389 12 MB as well - this can be done with
5391 setenv initrd_high 00c00000
5393 If you set initrd_high to 0xFFFFFFFF, this is an
5394 indication to U-Boot that all addresses are legal
5395 for the Linux kernel, including addresses in flash
5396 memory. In this case U-Boot will NOT COPY the
5397 ramdisk at all. This may be useful to reduce the
5398 boot time on your system, but requires that this
5399 feature is supported by your Linux kernel.
5401 ipaddr - IP address; needed for tftpboot command
5403 loadaddr - Default load address for commands like "bootp",
5404 "rarpboot", "tftpboot", "loadb" or "diskboot"
5406 loads_echo - see CONFIG_LOADS_ECHO
5408 serverip - TFTP server IP address; needed for tftpboot command
5410 bootretry - see CONFIG_BOOT_RETRY_TIME
5412 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5414 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5416 ethprime - controls which interface is used first.
5418 ethact - controls which interface is currently active.
5419 For example you can do the following
5421 => setenv ethact FEC
5422 => ping 192.168.0.1 # traffic sent on FEC
5423 => setenv ethact SCC
5424 => ping 10.0.0.1 # traffic sent on SCC
5426 ethrotate - When set to "no" U-Boot does not go through all
5427 available network interfaces.
5428 It just stays at the currently selected interface.
5430 netretry - When set to "no" each network operation will
5431 either succeed or fail without retrying.
5432 When set to "once" the network operation will
5433 fail when all the available network interfaces
5434 are tried once without success.
5435 Useful on scripts which control the retry operation
5438 npe_ucode - set load address for the NPE microcode
5440 silent_linux - If set then Linux will be told to boot silently, by
5441 changing the console to be empty. If "yes" it will be
5442 made silent. If "no" it will not be made silent. If
5443 unset, then it will be made silent if the U-Boot console
5446 tftpsrcport - If this is set, the value is used for TFTP's
5449 tftpdstport - If this is set, the value is used for TFTP's UDP
5450 destination port instead of the Well Know Port 69.
5452 tftpblocksize - Block size to use for TFTP transfers; if not set,
5453 we use the TFTP server's default block size
5455 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5456 seconds, minimum value is 1000 = 1 second). Defines
5457 when a packet is considered to be lost so it has to
5458 be retransmitted. The default is 5000 = 5 seconds.
5459 Lowering this value may make downloads succeed
5460 faster in networks with high packet loss rates or
5461 with unreliable TFTP servers.
5463 vlan - When set to a value < 4095 the traffic over
5464 Ethernet is encapsulated/received over 802.1q
5467 The following image location variables contain the location of images
5468 used in booting. The "Image" column gives the role of the image and is
5469 not an environment variable name. The other columns are environment
5470 variable names. "File Name" gives the name of the file on a TFTP
5471 server, "RAM Address" gives the location in RAM the image will be
5472 loaded to, and "Flash Location" gives the image's address in NOR
5473 flash or offset in NAND flash.
5475 *Note* - these variables don't have to be defined for all boards, some
5476 boards currently use other variables for these purposes, and some
5477 boards use these variables for other purposes.
5479 Image File Name RAM Address Flash Location
5480 ----- --------- ----------- --------------
5481 u-boot u-boot u-boot_addr_r u-boot_addr
5482 Linux kernel bootfile kernel_addr_r kernel_addr
5483 device tree blob fdtfile fdt_addr_r fdt_addr
5484 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5486 The following environment variables may be used and automatically
5487 updated by the network boot commands ("bootp" and "rarpboot"),
5488 depending the information provided by your boot server:
5490 bootfile - see above
5491 dnsip - IP address of your Domain Name Server
5492 dnsip2 - IP address of your secondary Domain Name Server
5493 gatewayip - IP address of the Gateway (Router) to use
5494 hostname - Target hostname
5496 netmask - Subnet Mask
5497 rootpath - Pathname of the root filesystem on the NFS server
5498 serverip - see above
5501 There are two special Environment Variables:
5503 serial# - contains hardware identification information such
5504 as type string and/or serial number
5505 ethaddr - Ethernet address
5507 These variables can be set only once (usually during manufacturing of
5508 the board). U-Boot refuses to delete or overwrite these variables
5509 once they have been set once.
5512 Further special Environment Variables:
5514 ver - Contains the U-Boot version string as printed
5515 with the "version" command. This variable is
5516 readonly (see CONFIG_VERSION_VARIABLE).
5519 Please note that changes to some configuration parameters may take
5520 only effect after the next boot (yes, that's just like Windoze :-).
5523 Callback functions for environment variables:
5524 ---------------------------------------------
5526 For some environment variables, the behavior of u-boot needs to change
5527 when their values are changed. This functionality allows functions to
5528 be associated with arbitrary variables. On creation, overwrite, or
5529 deletion, the callback will provide the opportunity for some side
5530 effect to happen or for the change to be rejected.
5532 The callbacks are named and associated with a function using the
5533 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5535 These callbacks are associated with variables in one of two ways. The
5536 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5537 in the board configuration to a string that defines a list of
5538 associations. The list must be in the following format:
5540 entry = variable_name[:callback_name]
5543 If the callback name is not specified, then the callback is deleted.
5544 Spaces are also allowed anywhere in the list.
5546 Callbacks can also be associated by defining the ".callbacks" variable
5547 with the same list format above. Any association in ".callbacks" will
5548 override any association in the static list. You can define
5549 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5550 ".callbacks" environment variable in the default or embedded environment.
5553 Command Line Parsing:
5554 =====================
5556 There are two different command line parsers available with U-Boot:
5557 the old "simple" one, and the much more powerful "hush" shell:
5559 Old, simple command line parser:
5560 --------------------------------
5562 - supports environment variables (through setenv / saveenv commands)
5563 - several commands on one line, separated by ';'
5564 - variable substitution using "... ${name} ..." syntax
5565 - special characters ('$', ';') can be escaped by prefixing with '\',
5567 setenv bootcmd bootm \${address}
5568 - You can also escape text by enclosing in single apostrophes, for example:
5569 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5574 - similar to Bourne shell, with control structures like
5575 if...then...else...fi, for...do...done; while...do...done,
5576 until...do...done, ...
5577 - supports environment ("global") variables (through setenv / saveenv
5578 commands) and local shell variables (through standard shell syntax
5579 "name=value"); only environment variables can be used with "run"
5585 (1) If a command line (or an environment variable executed by a "run"
5586 command) contains several commands separated by semicolon, and
5587 one of these commands fails, then the remaining commands will be
5590 (2) If you execute several variables with one call to run (i. e.
5591 calling run with a list of variables as arguments), any failing
5592 command will cause "run" to terminate, i. e. the remaining
5593 variables are not executed.
5595 Note for Redundant Ethernet Interfaces:
5596 =======================================
5598 Some boards come with redundant Ethernet interfaces; U-Boot supports
5599 such configurations and is capable of automatic selection of a
5600 "working" interface when needed. MAC assignment works as follows:
5602 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5603 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5604 "eth1addr" (=>eth1), "eth2addr", ...
5606 If the network interface stores some valid MAC address (for instance
5607 in SROM), this is used as default address if there is NO correspon-
5608 ding setting in the environment; if the corresponding environment
5609 variable is set, this overrides the settings in the card; that means:
5611 o If the SROM has a valid MAC address, and there is no address in the
5612 environment, the SROM's address is used.
5614 o If there is no valid address in the SROM, and a definition in the
5615 environment exists, then the value from the environment variable is
5618 o If both the SROM and the environment contain a MAC address, and
5619 both addresses are the same, this MAC address is used.
5621 o If both the SROM and the environment contain a MAC address, and the
5622 addresses differ, the value from the environment is used and a
5625 o If neither SROM nor the environment contain a MAC address, an error
5626 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5627 a random, locally-assigned MAC is used.
5629 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5630 will be programmed into hardware as part of the initialization process. This
5631 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5632 The naming convention is as follows:
5633 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5638 U-Boot is capable of booting (and performing other auxiliary operations on)
5639 images in two formats:
5641 New uImage format (FIT)
5642 -----------------------
5644 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5645 to Flattened Device Tree). It allows the use of images with multiple
5646 components (several kernels, ramdisks, etc.), with contents protected by
5647 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5653 Old image format is based on binary files which can be basically anything,
5654 preceded by a special header; see the definitions in include/image.h for
5655 details; basically, the header defines the following image properties:
5657 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5658 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5659 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5660 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5662 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5663 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5664 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5665 * Compression Type (uncompressed, gzip, bzip2)
5671 The header is marked by a special Magic Number, and both the header
5672 and the data portions of the image are secured against corruption by
5679 Although U-Boot should support any OS or standalone application
5680 easily, the main focus has always been on Linux during the design of
5683 U-Boot includes many features that so far have been part of some
5684 special "boot loader" code within the Linux kernel. Also, any
5685 "initrd" images to be used are no longer part of one big Linux image;
5686 instead, kernel and "initrd" are separate images. This implementation
5687 serves several purposes:
5689 - the same features can be used for other OS or standalone
5690 applications (for instance: using compressed images to reduce the
5691 Flash memory footprint)
5693 - it becomes much easier to port new Linux kernel versions because
5694 lots of low-level, hardware dependent stuff are done by U-Boot
5696 - the same Linux kernel image can now be used with different "initrd"
5697 images; of course this also means that different kernel images can
5698 be run with the same "initrd". This makes testing easier (you don't
5699 have to build a new "zImage.initrd" Linux image when you just
5700 change a file in your "initrd"). Also, a field-upgrade of the
5701 software is easier now.
5707 Porting Linux to U-Boot based systems:
5708 ---------------------------------------
5710 U-Boot cannot save you from doing all the necessary modifications to
5711 configure the Linux device drivers for use with your target hardware
5712 (no, we don't intend to provide a full virtual machine interface to
5715 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5717 Just make sure your machine specific header file (for instance
5718 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5719 Information structure as we define in include/asm-<arch>/u-boot.h,
5720 and make sure that your definition of IMAP_ADDR uses the same value
5721 as your U-Boot configuration in CONFIG_SYS_IMMR.
5723 Note that U-Boot now has a driver model, a unified model for drivers.
5724 If you are adding a new driver, plumb it into driver model. If there
5725 is no uclass available, you are encouraged to create one. See
5729 Configuring the Linux kernel:
5730 -----------------------------
5732 No specific requirements for U-Boot. Make sure you have some root
5733 device (initial ramdisk, NFS) for your target system.
5736 Building a Linux Image:
5737 -----------------------
5739 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5740 not used. If you use recent kernel source, a new build target
5741 "uImage" will exist which automatically builds an image usable by
5742 U-Boot. Most older kernels also have support for a "pImage" target,
5743 which was introduced for our predecessor project PPCBoot and uses a
5744 100% compatible format.
5748 make TQM850L_defconfig
5753 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5754 encapsulate a compressed Linux kernel image with header information,
5755 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5757 * build a standard "vmlinux" kernel image (in ELF binary format):
5759 * convert the kernel into a raw binary image:
5761 ${CROSS_COMPILE}-objcopy -O binary \
5762 -R .note -R .comment \
5763 -S vmlinux linux.bin
5765 * compress the binary image:
5769 * package compressed binary image for U-Boot:
5771 mkimage -A ppc -O linux -T kernel -C gzip \
5772 -a 0 -e 0 -n "Linux Kernel Image" \
5773 -d linux.bin.gz uImage
5776 The "mkimage" tool can also be used to create ramdisk images for use
5777 with U-Boot, either separated from the Linux kernel image, or
5778 combined into one file. "mkimage" encapsulates the images with a 64
5779 byte header containing information about target architecture,
5780 operating system, image type, compression method, entry points, time
5781 stamp, CRC32 checksums, etc.
5783 "mkimage" can be called in two ways: to verify existing images and
5784 print the header information, or to build new images.
5786 In the first form (with "-l" option) mkimage lists the information
5787 contained in the header of an existing U-Boot image; this includes
5788 checksum verification:
5790 tools/mkimage -l image
5791 -l ==> list image header information
5793 The second form (with "-d" option) is used to build a U-Boot image
5794 from a "data file" which is used as image payload:
5796 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5797 -n name -d data_file image
5798 -A ==> set architecture to 'arch'
5799 -O ==> set operating system to 'os'
5800 -T ==> set image type to 'type'
5801 -C ==> set compression type 'comp'
5802 -a ==> set load address to 'addr' (hex)
5803 -e ==> set entry point to 'ep' (hex)
5804 -n ==> set image name to 'name'
5805 -d ==> use image data from 'datafile'
5807 Right now, all Linux kernels for PowerPC systems use the same load
5808 address (0x00000000), but the entry point address depends on the
5811 - 2.2.x kernels have the entry point at 0x0000000C,
5812 - 2.3.x and later kernels have the entry point at 0x00000000.
5814 So a typical call to build a U-Boot image would read:
5816 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5817 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5818 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5819 > examples/uImage.TQM850L
5820 Image Name: 2.4.4 kernel for TQM850L
5821 Created: Wed Jul 19 02:34:59 2000
5822 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5823 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5824 Load Address: 0x00000000
5825 Entry Point: 0x00000000
5827 To verify the contents of the image (or check for corruption):
5829 -> tools/mkimage -l examples/uImage.TQM850L
5830 Image Name: 2.4.4 kernel for TQM850L
5831 Created: Wed Jul 19 02:34:59 2000
5832 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5833 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5834 Load Address: 0x00000000
5835 Entry Point: 0x00000000
5837 NOTE: for embedded systems where boot time is critical you can trade
5838 speed for memory and install an UNCOMPRESSED image instead: this
5839 needs more space in Flash, but boots much faster since it does not
5840 need to be uncompressed:
5842 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5843 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5844 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5845 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5846 > examples/uImage.TQM850L-uncompressed
5847 Image Name: 2.4.4 kernel for TQM850L
5848 Created: Wed Jul 19 02:34:59 2000
5849 Image Type: PowerPC Linux Kernel Image (uncompressed)
5850 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5851 Load Address: 0x00000000
5852 Entry Point: 0x00000000
5855 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5856 when your kernel is intended to use an initial ramdisk:
5858 -> tools/mkimage -n 'Simple Ramdisk Image' \
5859 > -A ppc -O linux -T ramdisk -C gzip \
5860 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5861 Image Name: Simple Ramdisk Image
5862 Created: Wed Jan 12 14:01:50 2000
5863 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5864 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5865 Load Address: 0x00000000
5866 Entry Point: 0x00000000
5868 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5869 option performs the converse operation of the mkimage's second form (the "-d"
5870 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5873 tools/dumpimage -i image -T type -p position data_file
5874 -i ==> extract from the 'image' a specific 'data_file'
5875 -T ==> set image type to 'type'
5876 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5879 Installing a Linux Image:
5880 -------------------------
5882 To downloading a U-Boot image over the serial (console) interface,
5883 you must convert the image to S-Record format:
5885 objcopy -I binary -O srec examples/image examples/image.srec
5887 The 'objcopy' does not understand the information in the U-Boot
5888 image header, so the resulting S-Record file will be relative to
5889 address 0x00000000. To load it to a given address, you need to
5890 specify the target address as 'offset' parameter with the 'loads'
5893 Example: install the image to address 0x40100000 (which on the
5894 TQM8xxL is in the first Flash bank):
5896 => erase 40100000 401FFFFF
5902 ## Ready for S-Record download ...
5903 ~>examples/image.srec
5904 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5906 15989 15990 15991 15992
5907 [file transfer complete]
5909 ## Start Addr = 0x00000000
5912 You can check the success of the download using the 'iminfo' command;
5913 this includes a checksum verification so you can be sure no data
5914 corruption happened:
5918 ## Checking Image at 40100000 ...
5919 Image Name: 2.2.13 for initrd on TQM850L
5920 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5921 Data Size: 335725 Bytes = 327 kB = 0 MB
5922 Load Address: 00000000
5923 Entry Point: 0000000c
5924 Verifying Checksum ... OK
5930 The "bootm" command is used to boot an application that is stored in
5931 memory (RAM or Flash). In case of a Linux kernel image, the contents
5932 of the "bootargs" environment variable is passed to the kernel as
5933 parameters. You can check and modify this variable using the
5934 "printenv" and "setenv" commands:
5937 => printenv bootargs
5938 bootargs=root=/dev/ram
5940 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5942 => printenv bootargs
5943 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5946 ## Booting Linux kernel at 40020000 ...
5947 Image Name: 2.2.13 for NFS on TQM850L
5948 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5949 Data Size: 381681 Bytes = 372 kB = 0 MB
5950 Load Address: 00000000
5951 Entry Point: 0000000c
5952 Verifying Checksum ... OK
5953 Uncompressing Kernel Image ... OK
5954 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
5955 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5956 time_init: decrementer frequency = 187500000/60
5957 Calibrating delay loop... 49.77 BogoMIPS
5958 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5961 If you want to boot a Linux kernel with initial RAM disk, you pass
5962 the memory addresses of both the kernel and the initrd image (PPBCOOT
5963 format!) to the "bootm" command:
5965 => imi 40100000 40200000
5967 ## Checking Image at 40100000 ...
5968 Image Name: 2.2.13 for initrd on TQM850L
5969 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5970 Data Size: 335725 Bytes = 327 kB = 0 MB
5971 Load Address: 00000000
5972 Entry Point: 0000000c
5973 Verifying Checksum ... OK
5975 ## Checking Image at 40200000 ...
5976 Image Name: Simple Ramdisk Image
5977 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5978 Data Size: 566530 Bytes = 553 kB = 0 MB
5979 Load Address: 00000000
5980 Entry Point: 00000000
5981 Verifying Checksum ... OK
5983 => bootm 40100000 40200000
5984 ## Booting Linux kernel at 40100000 ...
5985 Image Name: 2.2.13 for initrd on TQM850L
5986 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5987 Data Size: 335725 Bytes = 327 kB = 0 MB
5988 Load Address: 00000000
5989 Entry Point: 0000000c
5990 Verifying Checksum ... OK
5991 Uncompressing Kernel Image ... OK
5992 ## Loading RAMDisk Image at 40200000 ...
5993 Image Name: Simple Ramdisk Image
5994 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5995 Data Size: 566530 Bytes = 553 kB = 0 MB
5996 Load Address: 00000000
5997 Entry Point: 00000000
5998 Verifying Checksum ... OK
5999 Loading Ramdisk ... OK
6000 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
6001 Boot arguments: root=/dev/ram
6002 time_init: decrementer frequency = 187500000/60
6003 Calibrating delay loop... 49.77 BogoMIPS
6005 RAMDISK: Compressed image found at block 0
6006 VFS: Mounted root (ext2 filesystem).
6010 Boot Linux and pass a flat device tree:
6013 First, U-Boot must be compiled with the appropriate defines. See the section
6014 titled "Linux Kernel Interface" above for a more in depth explanation. The
6015 following is an example of how to start a kernel and pass an updated
6021 oft=oftrees/mpc8540ads.dtb
6022 => tftp $oftaddr $oft
6023 Speed: 1000, full duplex
6025 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6026 Filename 'oftrees/mpc8540ads.dtb'.
6027 Load address: 0x300000
6030 Bytes transferred = 4106 (100a hex)
6031 => tftp $loadaddr $bootfile
6032 Speed: 1000, full duplex
6034 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6036 Load address: 0x200000
6037 Loading:############
6039 Bytes transferred = 1029407 (fb51f hex)
6044 => bootm $loadaddr - $oftaddr
6045 ## Booting image at 00200000 ...
6046 Image Name: Linux-2.6.17-dirty
6047 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6048 Data Size: 1029343 Bytes = 1005.2 kB
6049 Load Address: 00000000
6050 Entry Point: 00000000
6051 Verifying Checksum ... OK
6052 Uncompressing Kernel Image ... OK
6053 Booting using flat device tree at 0x300000
6054 Using MPC85xx ADS machine description
6055 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6059 More About U-Boot Image Types:
6060 ------------------------------
6062 U-Boot supports the following image types:
6064 "Standalone Programs" are directly runnable in the environment
6065 provided by U-Boot; it is expected that (if they behave
6066 well) you can continue to work in U-Boot after return from
6067 the Standalone Program.
6068 "OS Kernel Images" are usually images of some Embedded OS which
6069 will take over control completely. Usually these programs
6070 will install their own set of exception handlers, device
6071 drivers, set up the MMU, etc. - this means, that you cannot
6072 expect to re-enter U-Boot except by resetting the CPU.
6073 "RAMDisk Images" are more or less just data blocks, and their
6074 parameters (address, size) are passed to an OS kernel that is
6076 "Multi-File Images" contain several images, typically an OS
6077 (Linux) kernel image and one or more data images like
6078 RAMDisks. This construct is useful for instance when you want
6079 to boot over the network using BOOTP etc., where the boot
6080 server provides just a single image file, but you want to get
6081 for instance an OS kernel and a RAMDisk image.
6083 "Multi-File Images" start with a list of image sizes, each
6084 image size (in bytes) specified by an "uint32_t" in network
6085 byte order. This list is terminated by an "(uint32_t)0".
6086 Immediately after the terminating 0 follow the images, one by
6087 one, all aligned on "uint32_t" boundaries (size rounded up to
6088 a multiple of 4 bytes).
6090 "Firmware Images" are binary images containing firmware (like
6091 U-Boot or FPGA images) which usually will be programmed to
6094 "Script files" are command sequences that will be executed by
6095 U-Boot's command interpreter; this feature is especially
6096 useful when you configure U-Boot to use a real shell (hush)
6097 as command interpreter.
6099 Booting the Linux zImage:
6100 -------------------------
6102 On some platforms, it's possible to boot Linux zImage. This is done
6103 using the "bootz" command. The syntax of "bootz" command is the same
6104 as the syntax of "bootm" command.
6106 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6107 kernel with raw initrd images. The syntax is slightly different, the
6108 address of the initrd must be augmented by it's size, in the following
6109 format: "<initrd addres>:<initrd size>".
6115 One of the features of U-Boot is that you can dynamically load and
6116 run "standalone" applications, which can use some resources of
6117 U-Boot like console I/O functions or interrupt services.
6119 Two simple examples are included with the sources:
6124 'examples/hello_world.c' contains a small "Hello World" Demo
6125 application; it is automatically compiled when you build U-Boot.
6126 It's configured to run at address 0x00040004, so you can play with it
6130 ## Ready for S-Record download ...
6131 ~>examples/hello_world.srec
6132 1 2 3 4 5 6 7 8 9 10 11 ...
6133 [file transfer complete]
6135 ## Start Addr = 0x00040004
6137 => go 40004 Hello World! This is a test.
6138 ## Starting application at 0x00040004 ...
6149 Hit any key to exit ...
6151 ## Application terminated, rc = 0x0
6153 Another example, which demonstrates how to register a CPM interrupt
6154 handler with the U-Boot code, can be found in 'examples/timer.c'.
6155 Here, a CPM timer is set up to generate an interrupt every second.
6156 The interrupt service routine is trivial, just printing a '.'
6157 character, but this is just a demo program. The application can be
6158 controlled by the following keys:
6160 ? - print current values og the CPM Timer registers
6161 b - enable interrupts and start timer
6162 e - stop timer and disable interrupts
6163 q - quit application
6166 ## Ready for S-Record download ...
6167 ~>examples/timer.srec
6168 1 2 3 4 5 6 7 8 9 10 11 ...
6169 [file transfer complete]
6171 ## Start Addr = 0x00040004
6174 ## Starting application at 0x00040004 ...
6177 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6180 [q, b, e, ?] Set interval 1000000 us
6183 [q, b, e, ?] ........
6184 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6187 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6190 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6193 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6195 [q, b, e, ?] ...Stopping timer
6197 [q, b, e, ?] ## Application terminated, rc = 0x0
6203 Over time, many people have reported problems when trying to use the
6204 "minicom" terminal emulation program for serial download. I (wd)
6205 consider minicom to be broken, and recommend not to use it. Under
6206 Unix, I recommend to use C-Kermit for general purpose use (and
6207 especially for kermit binary protocol download ("loadb" command), and
6208 use "cu" for S-Record download ("loads" command). See
6209 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6210 for help with kermit.
6213 Nevertheless, if you absolutely want to use it try adding this
6214 configuration to your "File transfer protocols" section:
6216 Name Program Name U/D FullScr IO-Red. Multi
6217 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6218 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6224 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6225 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6227 Building requires a cross environment; it is known to work on
6228 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6229 need gmake since the Makefiles are not compatible with BSD make).
6230 Note that the cross-powerpc package does not install include files;
6231 attempting to build U-Boot will fail because <machine/ansi.h> is
6232 missing. This file has to be installed and patched manually:
6234 # cd /usr/pkg/cross/powerpc-netbsd/include
6236 # ln -s powerpc machine
6237 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6238 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6240 Native builds *don't* work due to incompatibilities between native
6241 and U-Boot include files.
6243 Booting assumes that (the first part of) the image booted is a
6244 stage-2 loader which in turn loads and then invokes the kernel
6245 proper. Loader sources will eventually appear in the NetBSD source
6246 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6247 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6250 Implementation Internals:
6251 =========================
6253 The following is not intended to be a complete description of every
6254 implementation detail. However, it should help to understand the
6255 inner workings of U-Boot and make it easier to port it to custom
6259 Initial Stack, Global Data:
6260 ---------------------------
6262 The implementation of U-Boot is complicated by the fact that U-Boot
6263 starts running out of ROM (flash memory), usually without access to
6264 system RAM (because the memory controller is not initialized yet).
6265 This means that we don't have writable Data or BSS segments, and BSS
6266 is not initialized as zero. To be able to get a C environment working
6267 at all, we have to allocate at least a minimal stack. Implementation
6268 options for this are defined and restricted by the CPU used: Some CPU
6269 models provide on-chip memory (like the IMMR area on MPC8xx and
6270 MPC826x processors), on others (parts of) the data cache can be
6271 locked as (mis-) used as memory, etc.
6273 Chris Hallinan posted a good summary of these issues to the
6274 U-Boot mailing list:
6276 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6277 From: "Chris Hallinan" <clh@net1plus.com>
6278 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6281 Correct me if I'm wrong, folks, but the way I understand it
6282 is this: Using DCACHE as initial RAM for Stack, etc, does not
6283 require any physical RAM backing up the cache. The cleverness
6284 is that the cache is being used as a temporary supply of
6285 necessary storage before the SDRAM controller is setup. It's
6286 beyond the scope of this list to explain the details, but you
6287 can see how this works by studying the cache architecture and
6288 operation in the architecture and processor-specific manuals.
6290 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6291 is another option for the system designer to use as an
6292 initial stack/RAM area prior to SDRAM being available. Either
6293 option should work for you. Using CS 4 should be fine if your
6294 board designers haven't used it for something that would
6295 cause you grief during the initial boot! It is frequently not
6298 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6299 with your processor/board/system design. The default value
6300 you will find in any recent u-boot distribution in
6301 walnut.h should work for you. I'd set it to a value larger
6302 than your SDRAM module. If you have a 64MB SDRAM module, set
6303 it above 400_0000. Just make sure your board has no resources
6304 that are supposed to respond to that address! That code in
6305 start.S has been around a while and should work as is when
6306 you get the config right.
6311 It is essential to remember this, since it has some impact on the C
6312 code for the initialization procedures:
6314 * Initialized global data (data segment) is read-only. Do not attempt
6317 * Do not use any uninitialized global data (or implicitly initialized
6318 as zero data - BSS segment) at all - this is undefined, initiali-
6319 zation is performed later (when relocating to RAM).
6321 * Stack space is very limited. Avoid big data buffers or things like
6324 Having only the stack as writable memory limits means we cannot use
6325 normal global data to share information between the code. But it
6326 turned out that the implementation of U-Boot can be greatly
6327 simplified by making a global data structure (gd_t) available to all
6328 functions. We could pass a pointer to this data as argument to _all_
6329 functions, but this would bloat the code. Instead we use a feature of
6330 the GCC compiler (Global Register Variables) to share the data: we
6331 place a pointer (gd) to the global data into a register which we
6332 reserve for this purpose.
6334 When choosing a register for such a purpose we are restricted by the
6335 relevant (E)ABI specifications for the current architecture, and by
6336 GCC's implementation.
6338 For PowerPC, the following registers have specific use:
6340 R2: reserved for system use
6341 R3-R4: parameter passing and return values
6342 R5-R10: parameter passing
6343 R13: small data area pointer
6347 (U-Boot also uses R12 as internal GOT pointer. r12
6348 is a volatile register so r12 needs to be reset when
6349 going back and forth between asm and C)
6351 ==> U-Boot will use R2 to hold a pointer to the global data
6353 Note: on PPC, we could use a static initializer (since the
6354 address of the global data structure is known at compile time),
6355 but it turned out that reserving a register results in somewhat
6356 smaller code - although the code savings are not that big (on
6357 average for all boards 752 bytes for the whole U-Boot image,
6358 624 text + 127 data).
6360 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6361 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6363 ==> U-Boot will use P3 to hold a pointer to the global data
6365 On ARM, the following registers are used:
6367 R0: function argument word/integer result
6368 R1-R3: function argument word
6369 R9: platform specific
6370 R10: stack limit (used only if stack checking is enabled)
6371 R11: argument (frame) pointer
6372 R12: temporary workspace
6375 R15: program counter
6377 ==> U-Boot will use R9 to hold a pointer to the global data
6379 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6381 On Nios II, the ABI is documented here:
6382 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6384 ==> U-Boot will use gp to hold a pointer to the global data
6386 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6387 to access small data sections, so gp is free.
6389 On NDS32, the following registers are used:
6391 R0-R1: argument/return
6393 R15: temporary register for assembler
6394 R16: trampoline register
6395 R28: frame pointer (FP)
6396 R29: global pointer (GP)
6397 R30: link register (LP)
6398 R31: stack pointer (SP)
6399 PC: program counter (PC)
6401 ==> U-Boot will use R10 to hold a pointer to the global data
6403 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6404 or current versions of GCC may "optimize" the code too much.
6409 U-Boot runs in system state and uses physical addresses, i.e. the
6410 MMU is not used either for address mapping nor for memory protection.
6412 The available memory is mapped to fixed addresses using the memory
6413 controller. In this process, a contiguous block is formed for each
6414 memory type (Flash, SDRAM, SRAM), even when it consists of several
6415 physical memory banks.
6417 U-Boot is installed in the first 128 kB of the first Flash bank (on
6418 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6419 booting and sizing and initializing DRAM, the code relocates itself
6420 to the upper end of DRAM. Immediately below the U-Boot code some
6421 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6422 configuration setting]. Below that, a structure with global Board
6423 Info data is placed, followed by the stack (growing downward).
6425 Additionally, some exception handler code is copied to the low 8 kB
6426 of DRAM (0x00000000 ... 0x00001FFF).
6428 So a typical memory configuration with 16 MB of DRAM could look like
6431 0x0000 0000 Exception Vector code
6434 0x0000 2000 Free for Application Use
6440 0x00FB FF20 Monitor Stack (Growing downward)
6441 0x00FB FFAC Board Info Data and permanent copy of global data
6442 0x00FC 0000 Malloc Arena
6445 0x00FE 0000 RAM Copy of Monitor Code
6446 ... eventually: LCD or video framebuffer
6447 ... eventually: pRAM (Protected RAM - unchanged by reset)
6448 0x00FF FFFF [End of RAM]
6451 System Initialization:
6452 ----------------------
6454 In the reset configuration, U-Boot starts at the reset entry point
6455 (on most PowerPC systems at address 0x00000100). Because of the reset
6456 configuration for CS0# this is a mirror of the on board Flash memory.
6457 To be able to re-map memory U-Boot then jumps to its link address.
6458 To be able to implement the initialization code in C, a (small!)
6459 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6460 which provide such a feature like MPC8xx or MPC8260), or in a locked
6461 part of the data cache. After that, U-Boot initializes the CPU core,
6462 the caches and the SIU.
6464 Next, all (potentially) available memory banks are mapped using a
6465 preliminary mapping. For example, we put them on 512 MB boundaries
6466 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6467 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6468 programmed for SDRAM access. Using the temporary configuration, a
6469 simple memory test is run that determines the size of the SDRAM
6472 When there is more than one SDRAM bank, and the banks are of
6473 different size, the largest is mapped first. For equal size, the first
6474 bank (CS2#) is mapped first. The first mapping is always for address
6475 0x00000000, with any additional banks following immediately to create
6476 contiguous memory starting from 0.
6478 Then, the monitor installs itself at the upper end of the SDRAM area
6479 and allocates memory for use by malloc() and for the global Board
6480 Info data; also, the exception vector code is copied to the low RAM
6481 pages, and the final stack is set up.
6483 Only after this relocation will you have a "normal" C environment;
6484 until that you are restricted in several ways, mostly because you are
6485 running from ROM, and because the code will have to be relocated to a
6489 U-Boot Porting Guide:
6490 ----------------------
6492 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6496 int main(int argc, char *argv[])
6498 sighandler_t no_more_time;
6500 signal(SIGALRM, no_more_time);
6501 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6503 if (available_money > available_manpower) {
6504 Pay consultant to port U-Boot;
6508 Download latest U-Boot source;
6510 Subscribe to u-boot mailing list;
6513 email("Hi, I am new to U-Boot, how do I get started?");
6516 Read the README file in the top level directory;
6517 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6518 Read applicable doc/*.README;
6519 Read the source, Luke;
6520 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6523 if (available_money > toLocalCurrency ($2500))
6526 Add a lot of aggravation and time;
6528 if (a similar board exists) { /* hopefully... */
6529 cp -a board/<similar> board/<myboard>
6530 cp include/configs/<similar>.h include/configs/<myboard>.h
6532 Create your own board support subdirectory;
6533 Create your own board include/configs/<myboard>.h file;
6535 Edit new board/<myboard> files
6536 Edit new include/configs/<myboard>.h
6541 Add / modify source code;
6545 email("Hi, I am having problems...");
6547 Send patch file to the U-Boot email list;
6548 if (reasonable critiques)
6549 Incorporate improvements from email list code review;
6551 Defend code as written;
6557 void no_more_time (int sig)
6566 All contributions to U-Boot should conform to the Linux kernel
6567 coding style; see the file "Documentation/CodingStyle" and the script
6568 "scripts/Lindent" in your Linux kernel source directory.
6570 Source files originating from a different project (for example the
6571 MTD subsystem) are generally exempt from these guidelines and are not
6572 reformatted to ease subsequent migration to newer versions of those
6575 Please note that U-Boot is implemented in C (and to some small parts in
6576 Assembler); no C++ is used, so please do not use C++ style comments (//)
6579 Please also stick to the following formatting rules:
6580 - remove any trailing white space
6581 - use TAB characters for indentation and vertical alignment, not spaces
6582 - make sure NOT to use DOS '\r\n' line feeds
6583 - do not add more than 2 consecutive empty lines to source files
6584 - do not add trailing empty lines to source files
6586 Submissions which do not conform to the standards may be returned
6587 with a request to reformat the changes.
6593 Since the number of patches for U-Boot is growing, we need to
6594 establish some rules. Submissions which do not conform to these rules
6595 may be rejected, even when they contain important and valuable stuff.
6597 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6599 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6600 see http://lists.denx.de/mailman/listinfo/u-boot
6602 When you send a patch, please include the following information with
6605 * For bug fixes: a description of the bug and how your patch fixes
6606 this bug. Please try to include a way of demonstrating that the
6607 patch actually fixes something.
6609 * For new features: a description of the feature and your
6612 * A CHANGELOG entry as plaintext (separate from the patch)
6614 * For major contributions, your entry to the CREDITS file
6616 * When you add support for a new board, don't forget to add a
6617 maintainer e-mail address to the boards.cfg file, too.
6619 * If your patch adds new configuration options, don't forget to
6620 document these in the README file.
6622 * The patch itself. If you are using git (which is *strongly*
6623 recommended) you can easily generate the patch using the
6624 "git format-patch". If you then use "git send-email" to send it to
6625 the U-Boot mailing list, you will avoid most of the common problems
6626 with some other mail clients.
6628 If you cannot use git, use "diff -purN OLD NEW". If your version of
6629 diff does not support these options, then get the latest version of
6632 The current directory when running this command shall be the parent
6633 directory of the U-Boot source tree (i. e. please make sure that
6634 your patch includes sufficient directory information for the
6637 We prefer patches as plain text. MIME attachments are discouraged,
6638 and compressed attachments must not be used.
6640 * If one logical set of modifications affects or creates several
6641 files, all these changes shall be submitted in a SINGLE patch file.
6643 * Changesets that contain different, unrelated modifications shall be
6644 submitted as SEPARATE patches, one patch per changeset.
6649 * Before sending the patch, run the MAKEALL script on your patched
6650 source tree and make sure that no errors or warnings are reported
6651 for any of the boards.
6653 * Keep your modifications to the necessary minimum: A patch
6654 containing several unrelated changes or arbitrary reformats will be
6655 returned with a request to re-formatting / split it.
6657 * If you modify existing code, make sure that your new code does not
6658 add to the memory footprint of the code ;-) Small is beautiful!
6659 When adding new features, these should compile conditionally only
6660 (using #ifdef), and the resulting code with the new feature
6661 disabled must not need more memory than the old code without your
6664 * Remember that there is a size limit of 100 kB per message on the
6665 u-boot mailing list. Bigger patches will be moderated. If they are
6666 reasonable and not too big, they will be acknowledged. But patches
6667 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob