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_HAS_DP_DDR
615 Defines the SoC has DP-DDR used for DPAA.
617 CONFIG_SYS_FSL_SEC_BE
618 Defines the SEC controller register space as Big Endian
620 CONFIG_SYS_FSL_SEC_LE
621 Defines the SEC controller register space as Little Endian
623 - Intel Monahans options:
624 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
626 Defines the Monahans run mode to oscillator
627 ratio. Valid values are 8, 16, 24, 31. The core
628 frequency is this value multiplied by 13 MHz.
630 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
632 Defines the Monahans turbo mode to oscillator
633 ratio. Valid values are 1 (default if undefined) and
634 2. The core frequency as calculated above is multiplied
638 CONFIG_SYS_INIT_SP_OFFSET
640 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
641 pointer. This is needed for the temporary stack before
644 CONFIG_SYS_MIPS_CACHE_MODE
646 Cache operation mode for the MIPS CPU.
647 See also arch/mips/include/asm/mipsregs.h.
649 CONF_CM_CACHABLE_NO_WA
652 CONF_CM_CACHABLE_NONCOHERENT
656 CONF_CM_CACHABLE_ACCELERATED
658 CONFIG_SYS_XWAY_EBU_BOOTCFG
660 Special option for Lantiq XWAY SoCs for booting from NOR flash.
661 See also arch/mips/cpu/mips32/start.S.
663 CONFIG_XWAY_SWAP_BYTES
665 Enable compilation of tools/xway-swap-bytes needed for Lantiq
666 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
667 be swapped if a flash programmer is used.
670 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
672 Select high exception vectors of the ARM core, e.g., do not
673 clear the V bit of the c1 register of CP15.
675 CONFIG_SYS_THUMB_BUILD
677 Use this flag to build U-Boot using the Thumb instruction
678 set for ARM architectures. Thumb instruction set provides
679 better code density. For ARM architectures that support
680 Thumb2 this flag will result in Thumb2 code generated by
683 CONFIG_ARM_ERRATA_716044
684 CONFIG_ARM_ERRATA_742230
685 CONFIG_ARM_ERRATA_743622
686 CONFIG_ARM_ERRATA_751472
687 CONFIG_ARM_ERRATA_761320
688 CONFIG_ARM_ERRATA_773022
689 CONFIG_ARM_ERRATA_774769
690 CONFIG_ARM_ERRATA_794072
692 If set, the workarounds for these ARM errata are applied early
693 during U-Boot startup. Note that these options force the
694 workarounds to be applied; no CPU-type/version detection
695 exists, unlike the similar options in the Linux kernel. Do not
696 set these options unless they apply!
699 Generic timer clock source frequency.
701 COUNTER_FREQUENCY_REAL
702 Generic timer clock source frequency if the real clock is
703 different from COUNTER_FREQUENCY, and can only be determined
706 NOTE: The following can be machine specific errata. These
707 do have ability to provide rudimentary version and machine
708 specific checks, but expect no product checks.
709 CONFIG_ARM_ERRATA_430973
710 CONFIG_ARM_ERRATA_454179
711 CONFIG_ARM_ERRATA_621766
712 CONFIG_ARM_ERRATA_798870
713 CONFIG_ARM_ERRATA_801819
716 CONFIG_TEGRA_SUPPORT_NON_SECURE
718 Support executing U-Boot in non-secure (NS) mode. Certain
719 impossible actions will be skipped if the CPU is in NS mode,
720 such as ARM architectural timer initialization.
722 - Linux Kernel Interface:
725 U-Boot stores all clock information in Hz
726 internally. For binary compatibility with older Linux
727 kernels (which expect the clocks passed in the
728 bd_info data to be in MHz) the environment variable
729 "clocks_in_mhz" can be defined so that U-Boot
730 converts clock data to MHZ before passing it to the
732 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
733 "clocks_in_mhz=1" is automatically included in the
736 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
738 When transferring memsize parameter to Linux, some versions
739 expect it to be in bytes, others in MB.
740 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
744 New kernel versions are expecting firmware settings to be
745 passed using flattened device trees (based on open firmware
749 * New libfdt-based support
750 * Adds the "fdt" command
751 * The bootm command automatically updates the fdt
753 OF_CPU - The proper name of the cpus node (only required for
754 MPC512X and MPC5xxx based boards).
755 OF_SOC - The proper name of the soc node (only required for
756 MPC512X and MPC5xxx based boards).
757 OF_TBCLK - The timebase frequency.
758 OF_STDOUT_PATH - The path to the console device
760 boards with QUICC Engines require OF_QE to set UCC MAC
763 CONFIG_OF_BOARD_SETUP
765 Board code has addition modification that it wants to make
766 to the flat device tree before handing it off to the kernel
768 CONFIG_OF_SYSTEM_SETUP
770 Other code has addition modification that it wants to make
771 to the flat device tree before handing it off to the kernel.
772 This causes ft_system_setup() to be called before booting
777 This define fills in the correct boot CPU in the boot
778 param header, the default value is zero if undefined.
782 U-Boot can detect if an IDE device is present or not.
783 If not, and this new config option is activated, U-Boot
784 removes the ATA node from the DTS before booting Linux,
785 so the Linux IDE driver does not probe the device and
786 crash. This is needed for buggy hardware (uc101) where
787 no pull down resistor is connected to the signal IDE5V_DD7.
789 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
791 This setting is mandatory for all boards that have only one
792 machine type and must be used to specify the machine type
793 number as it appears in the ARM machine registry
794 (see http://www.arm.linux.org.uk/developer/machines/).
795 Only boards that have multiple machine types supported
796 in a single configuration file and the machine type is
797 runtime discoverable, do not have to use this setting.
799 - vxWorks boot parameters:
801 bootvx constructs a valid bootline using the following
802 environments variables: bootdev, bootfile, ipaddr, netmask,
803 serverip, gatewayip, hostname, othbootargs.
804 It loads the vxWorks image pointed bootfile.
806 Note: If a "bootargs" environment is defined, it will overwride
807 the defaults discussed just above.
809 - Cache Configuration:
810 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
811 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
812 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
814 - Cache Configuration for ARM:
815 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
817 CONFIG_SYS_PL310_BASE - Physical base address of PL310
818 controller register space
823 Define this if you want support for Amba PrimeCell PL010 UARTs.
827 Define this if you want support for Amba PrimeCell PL011 UARTs.
831 If you have Amba PrimeCell PL011 UARTs, set this variable to
832 the clock speed of the UARTs.
836 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
837 define this to a list of base addresses for each (supported)
838 port. See e.g. include/configs/versatile.h
840 CONFIG_SERIAL_HW_FLOW_CONTROL
842 Define this variable to enable hw flow control in serial driver.
843 Current user of this option is drivers/serial/nsl16550.c driver
846 Depending on board, define exactly one serial port
847 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
848 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
849 console by defining CONFIG_8xx_CONS_NONE
851 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
852 port routines must be defined elsewhere
853 (i.e. serial_init(), serial_getc(), ...)
856 Enables console device for a color framebuffer. Needs following
857 defines (cf. smiLynxEM, i8042)
858 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
860 VIDEO_HW_RECTFILL graphic chip supports
863 VIDEO_HW_BITBLT graphic chip supports
864 bit-blit (cf. smiLynxEM)
865 VIDEO_VISIBLE_COLS visible pixel columns
867 VIDEO_VISIBLE_ROWS visible pixel rows
868 VIDEO_PIXEL_SIZE bytes per pixel
869 VIDEO_DATA_FORMAT graphic data format
870 (0-5, cf. cfb_console.c)
871 VIDEO_FB_ADRS framebuffer address
872 VIDEO_KBD_INIT_FCT keyboard int fct
873 (i.e. rx51_kp_init())
874 VIDEO_TSTC_FCT test char fct
876 VIDEO_GETC_FCT get char fct
878 CONFIG_VIDEO_LOGO display Linux logo in
880 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
881 linux_logo.h for logo.
882 Requires CONFIG_VIDEO_LOGO
883 CONFIG_CONSOLE_EXTRA_INFO
884 additional board info beside
887 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
888 a limited number of ANSI escape sequences (cursor control,
889 erase functions and limited graphics rendition control).
891 When CONFIG_CFB_CONSOLE is defined, video console is
892 default i/o. Serial console can be forced with
893 environment 'console=serial'.
895 When CONFIG_SILENT_CONSOLE is defined, all console
896 messages (by U-Boot and Linux!) can be silenced with
897 the "silent" environment variable. See
898 doc/README.silent for more information.
900 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
902 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
906 CONFIG_BAUDRATE - in bps
907 Select one of the baudrates listed in
908 CONFIG_SYS_BAUDRATE_TABLE, see below.
909 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
911 - Console Rx buffer length
912 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
913 the maximum receive buffer length for the SMC.
914 This option is actual only for 82xx and 8xx possible.
915 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
916 must be defined, to setup the maximum idle timeout for
919 - Pre-Console Buffer:
920 Prior to the console being initialised (i.e. serial UART
921 initialised etc) all console output is silently discarded.
922 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
923 buffer any console messages prior to the console being
924 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
925 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
926 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
927 bytes are output before the console is initialised, the
928 earlier bytes are discarded.
930 Note that when printing the buffer a copy is made on the
931 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
933 'Sane' compilers will generate smaller code if
934 CONFIG_PRE_CON_BUF_SZ is a power of 2
936 - Safe printf() functions
937 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
938 the printf() functions. These are defined in
939 include/vsprintf.h and include snprintf(), vsnprintf() and
940 so on. Code size increase is approximately 300-500 bytes.
941 If this option is not given then these functions will
942 silently discard their buffer size argument - this means
943 you are not getting any overflow checking in this case.
945 - Boot Delay: CONFIG_BOOTDELAY - in seconds
946 Delay before automatically booting the default image;
947 set to -1 to disable autoboot.
948 set to -2 to autoboot with no delay and not check for abort
949 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
951 See doc/README.autoboot for these options that
952 work with CONFIG_BOOTDELAY. None are required.
953 CONFIG_BOOT_RETRY_TIME
954 CONFIG_BOOT_RETRY_MIN
955 CONFIG_AUTOBOOT_KEYED
956 CONFIG_AUTOBOOT_PROMPT
957 CONFIG_AUTOBOOT_DELAY_STR
958 CONFIG_AUTOBOOT_STOP_STR
959 CONFIG_ZERO_BOOTDELAY_CHECK
960 CONFIG_RESET_TO_RETRY
964 Only needed when CONFIG_BOOTDELAY is enabled;
965 define a command string that is automatically executed
966 when no character is read on the console interface
967 within "Boot Delay" after reset.
970 This can be used to pass arguments to the bootm
971 command. The value of CONFIG_BOOTARGS goes into the
972 environment value "bootargs".
974 CONFIG_RAMBOOT and CONFIG_NFSBOOT
975 The value of these goes into the environment as
976 "ramboot" and "nfsboot" respectively, and can be used
977 as a convenience, when switching between booting from
981 CONFIG_BOOTCOUNT_LIMIT
982 Implements a mechanism for detecting a repeating reboot
984 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
987 If no softreset save registers are found on the hardware
988 "bootcount" is stored in the environment. To prevent a
989 saveenv on all reboots, the environment variable
990 "upgrade_available" is used. If "upgrade_available" is
991 0, "bootcount" is always 0, if "upgrade_available" is
992 1 "bootcount" is incremented in the environment.
993 So the Userspace Applikation must set the "upgrade_available"
994 and "bootcount" variable to 0, if a boot was successfully.
999 When this option is #defined, the existence of the
1000 environment variable "preboot" will be checked
1001 immediately before starting the CONFIG_BOOTDELAY
1002 countdown and/or running the auto-boot command resp.
1003 entering interactive mode.
1005 This feature is especially useful when "preboot" is
1006 automatically generated or modified. For an example
1007 see the LWMON board specific code: here "preboot" is
1008 modified when the user holds down a certain
1009 combination of keys on the (special) keyboard when
1012 - Serial Download Echo Mode:
1014 If defined to 1, all characters received during a
1015 serial download (using the "loads" command) are
1016 echoed back. This might be needed by some terminal
1017 emulations (like "cu"), but may as well just take
1018 time on others. This setting #define's the initial
1019 value of the "loads_echo" environment variable.
1021 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1022 CONFIG_KGDB_BAUDRATE
1023 Select one of the baudrates listed in
1024 CONFIG_SYS_BAUDRATE_TABLE, see below.
1026 - Monitor Functions:
1027 Monitor commands can be included or excluded
1028 from the build by using the #include files
1029 <config_cmd_all.h> and #undef'ing unwanted
1030 commands, or adding #define's for wanted commands.
1032 The default command configuration includes all commands
1033 except those marked below with a "*".
1035 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1036 CONFIG_CMD_ASKENV * ask for env variable
1037 CONFIG_CMD_BDI bdinfo
1038 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1039 CONFIG_CMD_BMP * BMP support
1040 CONFIG_CMD_BSP * Board specific commands
1041 CONFIG_CMD_BOOTD bootd
1042 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1043 CONFIG_CMD_CACHE * icache, dcache
1044 CONFIG_CMD_CLK * clock command support
1045 CONFIG_CMD_CONSOLE coninfo
1046 CONFIG_CMD_CRC32 * crc32
1047 CONFIG_CMD_DATE * support for RTC, date/time...
1048 CONFIG_CMD_DHCP * DHCP support
1049 CONFIG_CMD_DIAG * Diagnostics
1050 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1051 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1052 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1053 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1054 CONFIG_CMD_DTT * Digital Therm and Thermostat
1055 CONFIG_CMD_ECHO echo arguments
1056 CONFIG_CMD_EDITENV edit env variable
1057 CONFIG_CMD_EEPROM * EEPROM read/write support
1058 CONFIG_CMD_ELF * bootelf, bootvx
1059 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1060 CONFIG_CMD_ENV_FLAGS * display details about env flags
1061 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1062 CONFIG_CMD_EXPORTENV * export the environment
1063 CONFIG_CMD_EXT2 * ext2 command support
1064 CONFIG_CMD_EXT4 * ext4 command support
1065 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1066 that work for multiple fs types
1067 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1068 CONFIG_CMD_SAVEENV saveenv
1069 CONFIG_CMD_FDC * Floppy Disk Support
1070 CONFIG_CMD_FAT * FAT command support
1071 CONFIG_CMD_FLASH flinfo, erase, protect
1072 CONFIG_CMD_FPGA FPGA device initialization support
1073 CONFIG_CMD_FUSE * Device fuse support
1074 CONFIG_CMD_GETTIME * Get time since boot
1075 CONFIG_CMD_GO * the 'go' command (exec code)
1076 CONFIG_CMD_GREPENV * search environment
1077 CONFIG_CMD_HASH * calculate hash / digest
1078 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1079 CONFIG_CMD_I2C * I2C serial bus support
1080 CONFIG_CMD_IDE * IDE harddisk support
1081 CONFIG_CMD_IMI iminfo
1082 CONFIG_CMD_IMLS List all images found in NOR flash
1083 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1084 CONFIG_CMD_IMMAP * IMMR dump support
1085 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1086 CONFIG_CMD_IMPORTENV * import an environment
1087 CONFIG_CMD_INI * import data from an ini file into the env
1088 CONFIG_CMD_IRQ * irqinfo
1089 CONFIG_CMD_ITEST Integer/string test of 2 values
1090 CONFIG_CMD_JFFS2 * JFFS2 Support
1091 CONFIG_CMD_KGDB * kgdb
1092 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1093 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1095 CONFIG_CMD_LOADB loadb
1096 CONFIG_CMD_LOADS loads
1097 CONFIG_CMD_MD5SUM * print md5 message digest
1098 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1099 CONFIG_CMD_MEMINFO * Display detailed memory information
1100 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1102 CONFIG_CMD_MEMTEST * mtest
1103 CONFIG_CMD_MISC Misc functions like sleep etc
1104 CONFIG_CMD_MMC * MMC memory mapped support
1105 CONFIG_CMD_MII * MII utility commands
1106 CONFIG_CMD_MTDPARTS * MTD partition support
1107 CONFIG_CMD_NAND * NAND support
1108 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1109 CONFIG_CMD_NFS NFS support
1110 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1111 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1112 CONFIG_CMD_PCI * pciinfo
1113 CONFIG_CMD_PCMCIA * PCMCIA support
1114 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1116 CONFIG_CMD_PORTIO * Port I/O
1117 CONFIG_CMD_READ * Read raw data from partition
1118 CONFIG_CMD_REGINFO * Register dump
1119 CONFIG_CMD_RUN run command in env variable
1120 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1121 CONFIG_CMD_SAVES * save S record dump
1122 CONFIG_CMD_SCSI * SCSI Support
1123 CONFIG_CMD_SDRAM * print SDRAM configuration information
1124 (requires CONFIG_CMD_I2C)
1125 CONFIG_CMD_SETGETDCR Support for DCR Register access
1127 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1128 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1129 (requires CONFIG_CMD_MEMORY)
1130 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1131 CONFIG_CMD_SOURCE "source" command Support
1132 CONFIG_CMD_SPI * SPI serial bus support
1133 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1134 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1135 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1136 CONFIG_CMD_TIMER * access to the system tick timer
1137 CONFIG_CMD_USB * USB support
1138 CONFIG_CMD_CDP * Cisco Discover Protocol support
1139 CONFIG_CMD_MFSL * Microblaze FSL support
1140 CONFIG_CMD_XIMG Load part of Multi Image
1141 CONFIG_CMD_UUID * Generate random UUID or GUID string
1143 EXAMPLE: If you want all functions except of network
1144 support you can write:
1146 #include "config_cmd_all.h"
1147 #undef CONFIG_CMD_NET
1150 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1152 Note: Don't enable the "icache" and "dcache" commands
1153 (configuration option CONFIG_CMD_CACHE) unless you know
1154 what you (and your U-Boot users) are doing. Data
1155 cache cannot be enabled on systems like the 8xx or
1156 8260 (where accesses to the IMMR region must be
1157 uncached), and it cannot be disabled on all other
1158 systems where we (mis-) use the data cache to hold an
1159 initial stack and some data.
1162 XXX - this list needs to get updated!
1164 - Regular expression support:
1166 If this variable is defined, U-Boot is linked against
1167 the SLRE (Super Light Regular Expression) library,
1168 which adds regex support to some commands, as for
1169 example "env grep" and "setexpr".
1173 If this variable is defined, U-Boot will use a device tree
1174 to configure its devices, instead of relying on statically
1175 compiled #defines in the board file. This option is
1176 experimental and only available on a few boards. The device
1177 tree is available in the global data as gd->fdt_blob.
1179 U-Boot needs to get its device tree from somewhere. This can
1180 be done using one of the two options below:
1183 If this variable is defined, U-Boot will embed a device tree
1184 binary in its image. This device tree file should be in the
1185 board directory and called <soc>-<board>.dts. The binary file
1186 is then picked up in board_init_f() and made available through
1187 the global data structure as gd->blob.
1190 If this variable is defined, U-Boot will build a device tree
1191 binary. It will be called u-boot.dtb. Architecture-specific
1192 code will locate it at run-time. Generally this works by:
1194 cat u-boot.bin u-boot.dtb >image.bin
1196 and in fact, U-Boot does this for you, creating a file called
1197 u-boot-dtb.bin which is useful in the common case. You can
1198 still use the individual files if you need something more
1203 If this variable is defined, it enables watchdog
1204 support for the SoC. There must be support in the SoC
1205 specific code for a watchdog. For the 8xx and 8260
1206 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1207 register. When supported for a specific SoC is
1208 available, then no further board specific code should
1209 be needed to use it.
1212 When using a watchdog circuitry external to the used
1213 SoC, then define this variable and provide board
1214 specific code for the "hw_watchdog_reset" function.
1216 CONFIG_AT91_HW_WDT_TIMEOUT
1217 specify the timeout in seconds. default 2 seconds.
1220 CONFIG_VERSION_VARIABLE
1221 If this variable is defined, an environment variable
1222 named "ver" is created by U-Boot showing the U-Boot
1223 version as printed by the "version" command.
1224 Any change to this variable will be reverted at the
1229 When CONFIG_CMD_DATE is selected, the type of the RTC
1230 has to be selected, too. Define exactly one of the
1233 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1234 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1235 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1236 CONFIG_RTC_MC146818 - use MC146818 RTC
1237 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1238 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1239 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1240 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1241 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1242 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1243 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1244 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1245 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1248 Note that if the RTC uses I2C, then the I2C interface
1249 must also be configured. See I2C Support, below.
1252 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1254 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1255 chip-ngpio pairs that tell the PCA953X driver the number of
1256 pins supported by a particular chip.
1258 Note that if the GPIO device uses I2C, then the I2C interface
1259 must also be configured. See I2C Support, below.
1262 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1263 accesses and can checksum them or write a list of them out
1264 to memory. See the 'iotrace' command for details. This is
1265 useful for testing device drivers since it can confirm that
1266 the driver behaves the same way before and after a code
1267 change. Currently this is supported on sandbox and arm. To
1268 add support for your architecture, add '#include <iotrace.h>'
1269 to the bottom of arch/<arch>/include/asm/io.h and test.
1271 Example output from the 'iotrace stats' command is below.
1272 Note that if the trace buffer is exhausted, the checksum will
1273 still continue to operate.
1276 Start: 10000000 (buffer start address)
1277 Size: 00010000 (buffer size)
1278 Offset: 00000120 (current buffer offset)
1279 Output: 10000120 (start + offset)
1280 Count: 00000018 (number of trace records)
1281 CRC32: 9526fb66 (CRC32 of all trace records)
1283 - Timestamp Support:
1285 When CONFIG_TIMESTAMP is selected, the timestamp
1286 (date and time) of an image is printed by image
1287 commands like bootm or iminfo. This option is
1288 automatically enabled when you select CONFIG_CMD_DATE .
1290 - Partition Labels (disklabels) Supported:
1291 Zero or more of the following:
1292 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1293 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1294 Intel architecture, USB sticks, etc.
1295 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1296 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1297 bootloader. Note 2TB partition limit; see
1299 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1301 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1302 CONFIG_CMD_SCSI) you must configure support for at
1303 least one non-MTD partition type as well.
1306 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1307 board configurations files but used nowhere!
1309 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1310 be performed by calling the function
1311 ide_set_reset(int reset)
1312 which has to be defined in a board specific file
1317 Set this to enable ATAPI support.
1322 Set this to enable support for disks larger than 137GB
1323 Also look at CONFIG_SYS_64BIT_LBA.
1324 Whithout these , LBA48 support uses 32bit variables and will 'only'
1325 support disks up to 2.1TB.
1327 CONFIG_SYS_64BIT_LBA:
1328 When enabled, makes the IDE subsystem use 64bit sector addresses.
1332 At the moment only there is only support for the
1333 SYM53C8XX SCSI controller; define
1334 CONFIG_SCSI_SYM53C8XX to enable it.
1336 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1337 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1338 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1339 maximum numbers of LUNs, SCSI ID's and target
1341 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1343 The environment variable 'scsidevs' is set to the number of
1344 SCSI devices found during the last scan.
1346 - NETWORK Support (PCI):
1348 Support for Intel 8254x/8257x gigabit chips.
1351 Utility code for direct access to the SPI bus on Intel 8257x.
1352 This does not do anything useful unless you set at least one
1353 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1355 CONFIG_E1000_SPI_GENERIC
1356 Allow generic access to the SPI bus on the Intel 8257x, for
1357 example with the "sspi" command.
1360 Management command for E1000 devices. When used on devices
1361 with SPI support you can reprogram the EEPROM from U-Boot.
1364 Support for Intel 82557/82559/82559ER chips.
1365 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1366 write routine for first time initialisation.
1369 Support for Digital 2114x chips.
1370 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1371 modem chip initialisation (KS8761/QS6611).
1374 Support for National dp83815 chips.
1377 Support for National dp8382[01] gigabit chips.
1379 - NETWORK Support (other):
1381 CONFIG_DRIVER_AT91EMAC
1382 Support for AT91RM9200 EMAC.
1385 Define this to use reduced MII inteface
1387 CONFIG_DRIVER_AT91EMAC_QUIET
1388 If this defined, the driver is quiet.
1389 The driver doen't show link status messages.
1391 CONFIG_CALXEDA_XGMAC
1392 Support for the Calxeda XGMAC device
1395 Support for SMSC's LAN91C96 chips.
1397 CONFIG_LAN91C96_BASE
1398 Define this to hold the physical address
1399 of the LAN91C96's I/O space
1401 CONFIG_LAN91C96_USE_32_BIT
1402 Define this to enable 32 bit addressing
1405 Support for SMSC's LAN91C111 chip
1407 CONFIG_SMC91111_BASE
1408 Define this to hold the physical address
1409 of the device (I/O space)
1411 CONFIG_SMC_USE_32_BIT
1412 Define this if data bus is 32 bits
1414 CONFIG_SMC_USE_IOFUNCS
1415 Define this to use i/o functions instead of macros
1416 (some hardware wont work with macros)
1418 CONFIG_DRIVER_TI_EMAC
1419 Support for davinci emac
1421 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1422 Define this if you have more then 3 PHYs.
1425 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1427 CONFIG_FTGMAC100_EGIGA
1428 Define this to use GE link update with gigabit PHY.
1429 Define this if FTGMAC100 is connected to gigabit PHY.
1430 If your system has 10/100 PHY only, it might not occur
1431 wrong behavior. Because PHY usually return timeout or
1432 useless data when polling gigabit status and gigabit
1433 control registers. This behavior won't affect the
1434 correctnessof 10/100 link speed update.
1437 Support for SMSC's LAN911x and LAN921x chips
1440 Define this to hold the physical address
1441 of the device (I/O space)
1443 CONFIG_SMC911X_32_BIT
1444 Define this if data bus is 32 bits
1446 CONFIG_SMC911X_16_BIT
1447 Define this if data bus is 16 bits. If your processor
1448 automatically converts one 32 bit word to two 16 bit
1449 words you may also try CONFIG_SMC911X_32_BIT.
1452 Support for Renesas on-chip Ethernet controller
1454 CONFIG_SH_ETHER_USE_PORT
1455 Define the number of ports to be used
1457 CONFIG_SH_ETHER_PHY_ADDR
1458 Define the ETH PHY's address
1460 CONFIG_SH_ETHER_CACHE_WRITEBACK
1461 If this option is set, the driver enables cache flush.
1465 Support for PWM modul on the imx6.
1469 Support TPM devices.
1471 CONFIG_TPM_TIS_INFINEON
1472 Support for Infineon i2c bus TPM devices. Only one device
1473 per system is supported at this time.
1475 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1476 Define the burst count bytes upper limit
1478 CONFIG_TPM_ATMEL_TWI
1479 Support for Atmel TWI TPM device. Requires I2C support.
1482 Support for generic parallel port TPM devices. Only one device
1483 per system is supported at this time.
1485 CONFIG_TPM_TIS_BASE_ADDRESS
1486 Base address where the generic TPM device is mapped
1487 to. Contemporary x86 systems usually map it at
1491 Add tpm monitor functions.
1492 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1493 provides monitor access to authorized functions.
1496 Define this to enable the TPM support library which provides
1497 functional interfaces to some TPM commands.
1498 Requires support for a TPM device.
1500 CONFIG_TPM_AUTH_SESSIONS
1501 Define this to enable authorized functions in the TPM library.
1502 Requires CONFIG_TPM and CONFIG_SHA1.
1505 At the moment only the UHCI host controller is
1506 supported (PIP405, MIP405, MPC5200); define
1507 CONFIG_USB_UHCI to enable it.
1508 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1509 and define CONFIG_USB_STORAGE to enable the USB
1512 Supported are USB Keyboards and USB Floppy drives
1514 MPC5200 USB requires additional defines:
1516 for 528 MHz Clock: 0x0001bbbb
1520 for differential drivers: 0x00001000
1521 for single ended drivers: 0x00005000
1522 for differential drivers on PSC3: 0x00000100
1523 for single ended drivers on PSC3: 0x00004100
1524 CONFIG_SYS_USB_EVENT_POLL
1525 May be defined to allow interrupt polling
1526 instead of using asynchronous interrupts
1528 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1529 txfilltuning field in the EHCI controller on reset.
1531 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1532 HW module registers.
1535 Define the below if you wish to use the USB console.
1536 Once firmware is rebuilt from a serial console issue the
1537 command "setenv stdin usbtty; setenv stdout usbtty" and
1538 attach your USB cable. The Unix command "dmesg" should print
1539 it has found a new device. The environment variable usbtty
1540 can be set to gserial or cdc_acm to enable your device to
1541 appear to a USB host as a Linux gserial device or a
1542 Common Device Class Abstract Control Model serial device.
1543 If you select usbtty = gserial you should be able to enumerate
1545 # modprobe usbserial vendor=0xVendorID product=0xProductID
1546 else if using cdc_acm, simply setting the environment
1547 variable usbtty to be cdc_acm should suffice. The following
1548 might be defined in YourBoardName.h
1551 Define this to build a UDC device
1554 Define this to have a tty type of device available to
1555 talk to the UDC device
1558 Define this to enable the high speed support for usb
1559 device and usbtty. If this feature is enabled, a routine
1560 int is_usbd_high_speed(void)
1561 also needs to be defined by the driver to dynamically poll
1562 whether the enumeration has succeded at high speed or full
1565 CONFIG_SYS_CONSOLE_IS_IN_ENV
1566 Define this if you want stdin, stdout &/or stderr to
1570 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1571 Derive USB clock from external clock "blah"
1572 - CONFIG_SYS_USB_EXTC_CLK 0x02
1574 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1575 Derive USB clock from brgclk
1576 - CONFIG_SYS_USB_BRG_CLK 0x04
1578 If you have a USB-IF assigned VendorID then you may wish to
1579 define your own vendor specific values either in BoardName.h
1580 or directly in usbd_vendor_info.h. If you don't define
1581 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1582 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1583 should pretend to be a Linux device to it's target host.
1585 CONFIG_USBD_MANUFACTURER
1586 Define this string as the name of your company for
1587 - CONFIG_USBD_MANUFACTURER "my company"
1589 CONFIG_USBD_PRODUCT_NAME
1590 Define this string as the name of your product
1591 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1593 CONFIG_USBD_VENDORID
1594 Define this as your assigned Vendor ID from the USB
1595 Implementors Forum. This *must* be a genuine Vendor ID
1596 to avoid polluting the USB namespace.
1597 - CONFIG_USBD_VENDORID 0xFFFF
1599 CONFIG_USBD_PRODUCTID
1600 Define this as the unique Product ID
1602 - CONFIG_USBD_PRODUCTID 0xFFFF
1604 - ULPI Layer Support:
1605 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1606 the generic ULPI layer. The generic layer accesses the ULPI PHY
1607 via the platform viewport, so you need both the genric layer and
1608 the viewport enabled. Currently only Chipidea/ARC based
1609 viewport is supported.
1610 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1611 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1612 If your ULPI phy needs a different reference clock than the
1613 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1614 the appropriate value in Hz.
1617 The MMC controller on the Intel PXA is supported. To
1618 enable this define CONFIG_MMC. The MMC can be
1619 accessed from the boot prompt by mapping the device
1620 to physical memory similar to flash. Command line is
1621 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1622 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1625 Support for Renesas on-chip MMCIF controller
1627 CONFIG_SH_MMCIF_ADDR
1628 Define the base address of MMCIF registers
1631 Define the clock frequency for MMCIF
1634 Enable the generic MMC driver
1636 CONFIG_SUPPORT_EMMC_BOOT
1637 Enable some additional features of the eMMC boot partitions.
1639 CONFIG_SUPPORT_EMMC_RPMB
1640 Enable the commands for reading, writing and programming the
1641 key for the Replay Protection Memory Block partition in eMMC.
1643 - USB Device Firmware Update (DFU) class support:
1644 CONFIG_USB_FUNCTION_DFU
1645 This enables the USB portion of the DFU USB class
1648 This enables the command "dfu" which is used to have
1649 U-Boot create a DFU class device via USB. This command
1650 requires that the "dfu_alt_info" environment variable be
1651 set and define the alt settings to expose to the host.
1654 This enables support for exposing (e)MMC devices via DFU.
1657 This enables support for exposing NAND devices via DFU.
1660 This enables support for exposing RAM via DFU.
1661 Note: DFU spec refer to non-volatile memory usage, but
1662 allow usages beyond the scope of spec - here RAM usage,
1663 one that would help mostly the developer.
1665 CONFIG_SYS_DFU_DATA_BUF_SIZE
1666 Dfu transfer uses a buffer before writing data to the
1667 raw storage device. Make the size (in bytes) of this buffer
1668 configurable. The size of this buffer is also configurable
1669 through the "dfu_bufsiz" environment variable.
1671 CONFIG_SYS_DFU_MAX_FILE_SIZE
1672 When updating files rather than the raw storage device,
1673 we use a static buffer to copy the file into and then write
1674 the buffer once we've been given the whole file. Define
1675 this to the maximum filesize (in bytes) for the buffer.
1676 Default is 4 MiB if undefined.
1678 DFU_DEFAULT_POLL_TIMEOUT
1679 Poll timeout [ms], is the timeout a device can send to the
1680 host. The host must wait for this timeout before sending
1681 a subsequent DFU_GET_STATUS request to the device.
1683 DFU_MANIFEST_POLL_TIMEOUT
1684 Poll timeout [ms], which the device sends to the host when
1685 entering dfuMANIFEST state. Host waits this timeout, before
1686 sending again an USB request to the device.
1688 - USB Device Android Fastboot support:
1689 CONFIG_USB_FUNCTION_FASTBOOT
1690 This enables the USB part of the fastboot gadget
1693 This enables the command "fastboot" which enables the Android
1694 fastboot mode for the platform's USB device. Fastboot is a USB
1695 protocol for downloading images, flashing and device control
1696 used on Android devices.
1697 See doc/README.android-fastboot for more information.
1699 CONFIG_ANDROID_BOOT_IMAGE
1700 This enables support for booting images which use the Android
1701 image format header.
1703 CONFIG_FASTBOOT_BUF_ADDR
1704 The fastboot protocol requires a large memory buffer for
1705 downloads. Define this to the starting RAM address to use for
1708 CONFIG_FASTBOOT_BUF_SIZE
1709 The fastboot protocol requires a large memory buffer for
1710 downloads. This buffer should be as large as possible for a
1711 platform. Define this to the size available RAM for fastboot.
1713 CONFIG_FASTBOOT_FLASH
1714 The fastboot protocol includes a "flash" command for writing
1715 the downloaded image to a non-volatile storage device. Define
1716 this to enable the "fastboot flash" command.
1718 CONFIG_FASTBOOT_FLASH_MMC_DEV
1719 The fastboot "flash" command requires additional information
1720 regarding the non-volatile storage device. Define this to
1721 the eMMC device that fastboot should use to store the image.
1723 CONFIG_FASTBOOT_GPT_NAME
1724 The fastboot "flash" command supports writing the downloaded
1725 image to the Protective MBR and the Primary GUID Partition
1726 Table. (Additionally, this downloaded image is post-processed
1727 to generate and write the Backup GUID Partition Table.)
1728 This occurs when the specified "partition name" on the
1729 "fastboot flash" command line matches this value.
1730 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1732 - Journaling Flash filesystem support:
1733 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1734 CONFIG_JFFS2_NAND_DEV
1735 Define these for a default partition on a NAND device
1737 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1738 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1739 Define these for a default partition on a NOR device
1741 CONFIG_SYS_JFFS_CUSTOM_PART
1742 Define this to create an own partition. You have to provide a
1743 function struct part_info* jffs2_part_info(int part_num)
1745 If you define only one JFFS2 partition you may also want to
1746 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1747 to disable the command chpart. This is the default when you
1748 have not defined a custom partition
1750 - FAT(File Allocation Table) filesystem write function support:
1753 Define this to enable support for saving memory data as a
1754 file in FAT formatted partition.
1756 This will also enable the command "fatwrite" enabling the
1757 user to write files to FAT.
1759 CBFS (Coreboot Filesystem) support
1762 Define this to enable support for reading from a Coreboot
1763 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1766 - FAT(File Allocation Table) filesystem cluster size:
1767 CONFIG_FS_FAT_MAX_CLUSTSIZE
1769 Define the max cluster size for fat operations else
1770 a default value of 65536 will be defined.
1773 See Kconfig help for available keyboard drivers.
1777 Define this to enable a custom keyboard support.
1778 This simply calls drv_keyboard_init() which must be
1779 defined in your board-specific files. This option is deprecated
1780 and is only used by novena. For new boards, use driver model
1786 Define this to enable video support (for output to
1789 CONFIG_VIDEO_CT69000
1791 Enable Chips & Technologies 69000 Video chip
1793 CONFIG_VIDEO_SMI_LYNXEM
1794 Enable Silicon Motion SMI 712/710/810 Video chip. The
1795 video output is selected via environment 'videoout'
1796 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1799 For the CT69000 and SMI_LYNXEM drivers, videomode is
1800 selected via environment 'videomode'. Two different ways
1802 - "videomode=num" 'num' is a standard LiLo mode numbers.
1803 Following standard modes are supported (* is default):
1805 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1806 -------------+---------------------------------------------
1807 8 bits | 0x301* 0x303 0x305 0x161 0x307
1808 15 bits | 0x310 0x313 0x316 0x162 0x319
1809 16 bits | 0x311 0x314 0x317 0x163 0x31A
1810 24 bits | 0x312 0x315 0x318 ? 0x31B
1811 -------------+---------------------------------------------
1812 (i.e. setenv videomode 317; saveenv; reset;)
1814 - "videomode=bootargs" all the video parameters are parsed
1815 from the bootargs. (See drivers/video/videomodes.c)
1818 CONFIG_VIDEO_SED13806
1819 Enable Epson SED13806 driver. This driver supports 8bpp
1820 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1821 or CONFIG_VIDEO_SED13806_16BPP
1824 Enable the Freescale DIU video driver. Reference boards for
1825 SOCs that have a DIU should define this macro to enable DIU
1826 support, and should also define these other macros:
1832 CONFIG_VIDEO_SW_CURSOR
1833 CONFIG_VGA_AS_SINGLE_DEVICE
1835 CONFIG_VIDEO_BMP_LOGO
1837 The DIU driver will look for the 'video-mode' environment
1838 variable, and if defined, enable the DIU as a console during
1839 boot. See the documentation file README.video for a
1840 description of this variable.
1842 - LCD Support: CONFIG_LCD
1844 Define this to enable LCD support (for output to LCD
1845 display); also select one of the supported displays
1846 by defining one of these:
1850 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1852 CONFIG_NEC_NL6448AC33:
1854 NEC NL6448AC33-18. Active, color, single scan.
1856 CONFIG_NEC_NL6448BC20
1858 NEC NL6448BC20-08. 6.5", 640x480.
1859 Active, color, single scan.
1861 CONFIG_NEC_NL6448BC33_54
1863 NEC NL6448BC33-54. 10.4", 640x480.
1864 Active, color, single scan.
1868 Sharp 320x240. Active, color, single scan.
1869 It isn't 16x9, and I am not sure what it is.
1871 CONFIG_SHARP_LQ64D341
1873 Sharp LQ64D341 display, 640x480.
1874 Active, color, single scan.
1878 HLD1045 display, 640x480.
1879 Active, color, single scan.
1883 Optrex CBL50840-2 NF-FW 99 22 M5
1885 Hitachi LMG6912RPFC-00T
1889 320x240. Black & white.
1891 Normally display is black on white background; define
1892 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1894 CONFIG_LCD_ALIGNMENT
1896 Normally the LCD is page-aligned (typically 4KB). If this is
1897 defined then the LCD will be aligned to this value instead.
1898 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1899 here, since it is cheaper to change data cache settings on
1900 a per-section basis.
1902 CONFIG_CONSOLE_SCROLL_LINES
1904 When the console need to be scrolled, this is the number of
1905 lines to scroll by. It defaults to 1. Increasing this makes
1906 the console jump but can help speed up operation when scrolling
1911 Sometimes, for example if the display is mounted in portrait
1912 mode or even if it's mounted landscape but rotated by 180degree,
1913 we need to rotate our content of the display relative to the
1914 framebuffer, so that user can read the messages which are
1916 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1917 initialized with a given rotation from "vl_rot" out of
1918 "vidinfo_t" which is provided by the board specific code.
1919 The value for vl_rot is coded as following (matching to
1920 fbcon=rotate:<n> linux-kernel commandline):
1921 0 = no rotation respectively 0 degree
1922 1 = 90 degree rotation
1923 2 = 180 degree rotation
1924 3 = 270 degree rotation
1926 If CONFIG_LCD_ROTATION is not defined, the console will be
1927 initialized with 0degree rotation.
1931 Support drawing of RLE8-compressed bitmaps on the LCD.
1935 Enables an 'i2c edid' command which can read EDID
1936 information over I2C from an attached LCD display.
1938 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1940 If this option is set, the environment is checked for
1941 a variable "splashimage". If found, the usual display
1942 of logo, copyright and system information on the LCD
1943 is suppressed and the BMP image at the address
1944 specified in "splashimage" is loaded instead. The
1945 console is redirected to the "nulldev", too. This
1946 allows for a "silent" boot where a splash screen is
1947 loaded very quickly after power-on.
1949 CONFIG_SPLASHIMAGE_GUARD
1951 If this option is set, then U-Boot will prevent the environment
1952 variable "splashimage" from being set to a problematic address
1953 (see README.displaying-bmps).
1954 This option is useful for targets where, due to alignment
1955 restrictions, an improperly aligned BMP image will cause a data
1956 abort. If you think you will not have problems with unaligned
1957 accesses (for example because your toolchain prevents them)
1958 there is no need to set this option.
1960 CONFIG_SPLASH_SCREEN_ALIGN
1962 If this option is set the splash image can be freely positioned
1963 on the screen. Environment variable "splashpos" specifies the
1964 position as "x,y". If a positive number is given it is used as
1965 number of pixel from left/top. If a negative number is given it
1966 is used as number of pixel from right/bottom. You can also
1967 specify 'm' for centering the image.
1970 setenv splashpos m,m
1971 => image at center of screen
1973 setenv splashpos 30,20
1974 => image at x = 30 and y = 20
1976 setenv splashpos -10,m
1977 => vertically centered image
1978 at x = dspWidth - bmpWidth - 9
1980 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1982 If this option is set, additionally to standard BMP
1983 images, gzipped BMP images can be displayed via the
1984 splashscreen support or the bmp command.
1986 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1988 If this option is set, 8-bit RLE compressed BMP images
1989 can be displayed via the splashscreen support or the
1992 - Do compressing for memory range:
1995 If this option is set, it would use zlib deflate method
1996 to compress the specified memory at its best effort.
1998 - Compression support:
2001 Enabled by default to support gzip compressed images.
2005 If this option is set, support for bzip2 compressed
2006 images is included. If not, only uncompressed and gzip
2007 compressed images are supported.
2009 NOTE: the bzip2 algorithm requires a lot of RAM, so
2010 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2015 If this option is set, support for lzma compressed
2018 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2019 requires an amount of dynamic memory that is given by the
2022 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2024 Where lc and lp stand for, respectively, Literal context bits
2025 and Literal pos bits.
2027 This value is upper-bounded by 14MB in the worst case. Anyway,
2028 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2029 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2030 a very small buffer.
2032 Use the lzmainfo tool to determinate the lc and lp values and
2033 then calculate the amount of needed dynamic memory (ensuring
2034 the appropriate CONFIG_SYS_MALLOC_LEN value).
2038 If this option is set, support for LZO compressed images
2044 The address of PHY on MII bus.
2046 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2048 The clock frequency of the MII bus
2052 If this option is set, support for speed/duplex
2053 detection of gigabit PHY is included.
2055 CONFIG_PHY_RESET_DELAY
2057 Some PHY like Intel LXT971A need extra delay after
2058 reset before any MII register access is possible.
2059 For such PHY, set this option to the usec delay
2060 required. (minimum 300usec for LXT971A)
2062 CONFIG_PHY_CMD_DELAY (ppc4xx)
2064 Some PHY like Intel LXT971A need extra delay after
2065 command issued before MII status register can be read
2070 Define a default value for the IP address to use for
2071 the default Ethernet interface, in case this is not
2072 determined through e.g. bootp.
2073 (Environment variable "ipaddr")
2075 - Server IP address:
2078 Defines a default value for the IP address of a TFTP
2079 server to contact when using the "tftboot" command.
2080 (Environment variable "serverip")
2082 CONFIG_KEEP_SERVERADDR
2084 Keeps the server's MAC address, in the env 'serveraddr'
2085 for passing to bootargs (like Linux's netconsole option)
2087 - Gateway IP address:
2090 Defines a default value for the IP address of the
2091 default router where packets to other networks are
2093 (Environment variable "gatewayip")
2098 Defines a default value for the subnet mask (or
2099 routing prefix) which is used to determine if an IP
2100 address belongs to the local subnet or needs to be
2101 forwarded through a router.
2102 (Environment variable "netmask")
2104 - Multicast TFTP Mode:
2107 Defines whether you want to support multicast TFTP as per
2108 rfc-2090; for example to work with atftp. Lets lots of targets
2109 tftp down the same boot image concurrently. Note: the Ethernet
2110 driver in use must provide a function: mcast() to join/leave a
2113 - BOOTP Recovery Mode:
2114 CONFIG_BOOTP_RANDOM_DELAY
2116 If you have many targets in a network that try to
2117 boot using BOOTP, you may want to avoid that all
2118 systems send out BOOTP requests at precisely the same
2119 moment (which would happen for instance at recovery
2120 from a power failure, when all systems will try to
2121 boot, thus flooding the BOOTP server. Defining
2122 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2123 inserted before sending out BOOTP requests. The
2124 following delays are inserted then:
2126 1st BOOTP request: delay 0 ... 1 sec
2127 2nd BOOTP request: delay 0 ... 2 sec
2128 3rd BOOTP request: delay 0 ... 4 sec
2130 BOOTP requests: delay 0 ... 8 sec
2132 CONFIG_BOOTP_ID_CACHE_SIZE
2134 BOOTP packets are uniquely identified using a 32-bit ID. The
2135 server will copy the ID from client requests to responses and
2136 U-Boot will use this to determine if it is the destination of
2137 an incoming response. Some servers will check that addresses
2138 aren't in use before handing them out (usually using an ARP
2139 ping) and therefore take up to a few hundred milliseconds to
2140 respond. Network congestion may also influence the time it
2141 takes for a response to make it back to the client. If that
2142 time is too long, U-Boot will retransmit requests. In order
2143 to allow earlier responses to still be accepted after these
2144 retransmissions, U-Boot's BOOTP client keeps a small cache of
2145 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2146 cache. The default is to keep IDs for up to four outstanding
2147 requests. Increasing this will allow U-Boot to accept offers
2148 from a BOOTP client in networks with unusually high latency.
2150 - DHCP Advanced Options:
2151 You can fine tune the DHCP functionality by defining
2152 CONFIG_BOOTP_* symbols:
2154 CONFIG_BOOTP_SUBNETMASK
2155 CONFIG_BOOTP_GATEWAY
2156 CONFIG_BOOTP_HOSTNAME
2157 CONFIG_BOOTP_NISDOMAIN
2158 CONFIG_BOOTP_BOOTPATH
2159 CONFIG_BOOTP_BOOTFILESIZE
2162 CONFIG_BOOTP_SEND_HOSTNAME
2163 CONFIG_BOOTP_NTPSERVER
2164 CONFIG_BOOTP_TIMEOFFSET
2165 CONFIG_BOOTP_VENDOREX
2166 CONFIG_BOOTP_MAY_FAIL
2168 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2169 environment variable, not the BOOTP server.
2171 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2172 after the configured retry count, the call will fail
2173 instead of starting over. This can be used to fail over
2174 to Link-local IP address configuration if the DHCP server
2177 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2178 serverip from a DHCP server, it is possible that more
2179 than one DNS serverip is offered to the client.
2180 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2181 serverip will be stored in the additional environment
2182 variable "dnsip2". The first DNS serverip is always
2183 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2186 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2187 to do a dynamic update of a DNS server. To do this, they
2188 need the hostname of the DHCP requester.
2189 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2190 of the "hostname" environment variable is passed as
2191 option 12 to the DHCP server.
2193 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2195 A 32bit value in microseconds for a delay between
2196 receiving a "DHCP Offer" and sending the "DHCP Request".
2197 This fixes a problem with certain DHCP servers that don't
2198 respond 100% of the time to a "DHCP request". E.g. On an
2199 AT91RM9200 processor running at 180MHz, this delay needed
2200 to be *at least* 15,000 usec before a Windows Server 2003
2201 DHCP server would reply 100% of the time. I recommend at
2202 least 50,000 usec to be safe. The alternative is to hope
2203 that one of the retries will be successful but note that
2204 the DHCP timeout and retry process takes a longer than
2207 - Link-local IP address negotiation:
2208 Negotiate with other link-local clients on the local network
2209 for an address that doesn't require explicit configuration.
2210 This is especially useful if a DHCP server cannot be guaranteed
2211 to exist in all environments that the device must operate.
2213 See doc/README.link-local for more information.
2216 CONFIG_CDP_DEVICE_ID
2218 The device id used in CDP trigger frames.
2220 CONFIG_CDP_DEVICE_ID_PREFIX
2222 A two character string which is prefixed to the MAC address
2227 A printf format string which contains the ascii name of
2228 the port. Normally is set to "eth%d" which sets
2229 eth0 for the first Ethernet, eth1 for the second etc.
2231 CONFIG_CDP_CAPABILITIES
2233 A 32bit integer which indicates the device capabilities;
2234 0x00000010 for a normal host which does not forwards.
2238 An ascii string containing the version of the software.
2242 An ascii string containing the name of the platform.
2246 A 32bit integer sent on the trigger.
2248 CONFIG_CDP_POWER_CONSUMPTION
2250 A 16bit integer containing the power consumption of the
2251 device in .1 of milliwatts.
2253 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2255 A byte containing the id of the VLAN.
2257 - Status LED: CONFIG_STATUS_LED
2259 Several configurations allow to display the current
2260 status using a LED. For instance, the LED will blink
2261 fast while running U-Boot code, stop blinking as
2262 soon as a reply to a BOOTP request was received, and
2263 start blinking slow once the Linux kernel is running
2264 (supported by a status LED driver in the Linux
2265 kernel). Defining CONFIG_STATUS_LED enables this
2271 The status LED can be connected to a GPIO pin.
2272 In such cases, the gpio_led driver can be used as a
2273 status LED backend implementation. Define CONFIG_GPIO_LED
2274 to include the gpio_led driver in the U-Boot binary.
2276 CONFIG_GPIO_LED_INVERTED_TABLE
2277 Some GPIO connected LEDs may have inverted polarity in which
2278 case the GPIO high value corresponds to LED off state and
2279 GPIO low value corresponds to LED on state.
2280 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2281 with a list of GPIO LEDs that have inverted polarity.
2283 - CAN Support: CONFIG_CAN_DRIVER
2285 Defining CONFIG_CAN_DRIVER enables CAN driver support
2286 on those systems that support this (optional)
2287 feature, like the TQM8xxL modules.
2289 - I2C Support: CONFIG_SYS_I2C
2291 This enable the NEW i2c subsystem, and will allow you to use
2292 i2c commands at the u-boot command line (as long as you set
2293 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2294 based realtime clock chips or other i2c devices. See
2295 common/cmd_i2c.c for a description of the command line
2298 ported i2c driver to the new framework:
2299 - drivers/i2c/soft_i2c.c:
2300 - activate first bus with CONFIG_SYS_I2C_SOFT define
2301 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2302 for defining speed and slave address
2303 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2304 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2305 for defining speed and slave address
2306 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2307 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2308 for defining speed and slave address
2309 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2310 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2311 for defining speed and slave address
2313 - drivers/i2c/fsl_i2c.c:
2314 - activate i2c driver with CONFIG_SYS_I2C_FSL
2315 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2316 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2317 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2319 - If your board supports a second fsl i2c bus, define
2320 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2321 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2322 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2325 - drivers/i2c/tegra_i2c.c:
2326 - activate this driver with CONFIG_SYS_I2C_TEGRA
2327 - This driver adds 4 i2c buses with a fix speed from
2328 100000 and the slave addr 0!
2330 - drivers/i2c/ppc4xx_i2c.c
2331 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2332 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2333 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2335 - drivers/i2c/i2c_mxc.c
2336 - activate this driver with CONFIG_SYS_I2C_MXC
2337 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2338 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2339 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2340 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2341 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2342 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2343 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2344 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2345 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2346 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2347 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2348 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2349 If those defines are not set, default value is 100000
2350 for speed, and 0 for slave.
2352 - drivers/i2c/rcar_i2c.c:
2353 - activate this driver with CONFIG_SYS_I2C_RCAR
2354 - This driver adds 4 i2c buses
2356 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2357 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2358 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2359 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2360 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2361 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2362 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2363 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2364 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2366 - drivers/i2c/sh_i2c.c:
2367 - activate this driver with CONFIG_SYS_I2C_SH
2368 - This driver adds from 2 to 5 i2c buses
2370 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2371 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2372 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2373 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2374 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2375 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2376 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2377 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2378 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2379 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2380 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2381 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2382 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2384 - drivers/i2c/omap24xx_i2c.c
2385 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2386 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2387 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2388 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2389 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2390 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2391 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2392 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2393 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2394 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2395 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2397 - drivers/i2c/zynq_i2c.c
2398 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2399 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2400 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2402 - drivers/i2c/s3c24x0_i2c.c:
2403 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2404 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2405 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2406 with a fix speed from 100000 and the slave addr 0!
2408 - drivers/i2c/ihs_i2c.c
2409 - activate this driver with CONFIG_SYS_I2C_IHS
2410 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2411 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2412 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2413 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2414 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2415 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2416 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2417 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2418 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2419 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2420 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2421 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2422 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2423 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2424 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2425 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2426 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2427 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2428 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2429 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2430 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2434 CONFIG_SYS_NUM_I2C_BUSES
2435 Hold the number of i2c buses you want to use. If you
2436 don't use/have i2c muxes on your i2c bus, this
2437 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2440 CONFIG_SYS_I2C_DIRECT_BUS
2441 define this, if you don't use i2c muxes on your hardware.
2442 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2445 CONFIG_SYS_I2C_MAX_HOPS
2446 define how many muxes are maximal consecutively connected
2447 on one i2c bus. If you not use i2c muxes, omit this
2450 CONFIG_SYS_I2C_BUSES
2451 hold a list of buses you want to use, only used if
2452 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2453 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2454 CONFIG_SYS_NUM_I2C_BUSES = 9:
2456 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2457 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2458 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2459 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2460 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2461 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2462 {1, {I2C_NULL_HOP}}, \
2463 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2464 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2468 bus 0 on adapter 0 without a mux
2469 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2470 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2471 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2472 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2473 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2474 bus 6 on adapter 1 without a mux
2475 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2476 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2478 If you do not have i2c muxes on your board, omit this define.
2480 - Legacy I2C Support: CONFIG_HARD_I2C
2482 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2483 provides the following compelling advantages:
2485 - more than one i2c adapter is usable
2486 - approved multibus support
2487 - better i2c mux support
2489 ** Please consider updating your I2C driver now. **
2491 These enable legacy I2C serial bus commands. Defining
2492 CONFIG_HARD_I2C will include the appropriate I2C driver
2493 for the selected CPU.
2495 This will allow you to use i2c commands at the u-boot
2496 command line (as long as you set CONFIG_CMD_I2C in
2497 CONFIG_COMMANDS) and communicate with i2c based realtime
2498 clock chips. See common/cmd_i2c.c for a description of the
2499 command line interface.
2501 CONFIG_HARD_I2C selects a hardware I2C controller.
2503 There are several other quantities that must also be
2504 defined when you define CONFIG_HARD_I2C.
2506 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2507 to be the frequency (in Hz) at which you wish your i2c bus
2508 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2509 the CPU's i2c node address).
2511 Now, the u-boot i2c code for the mpc8xx
2512 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2513 and so its address should therefore be cleared to 0 (See,
2514 eg, MPC823e User's Manual p.16-473). So, set
2515 CONFIG_SYS_I2C_SLAVE to 0.
2517 CONFIG_SYS_I2C_INIT_MPC5XXX
2519 When a board is reset during an i2c bus transfer
2520 chips might think that the current transfer is still
2521 in progress. Reset the slave devices by sending start
2522 commands until the slave device responds.
2524 That's all that's required for CONFIG_HARD_I2C.
2526 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2527 then the following macros need to be defined (examples are
2528 from include/configs/lwmon.h):
2532 (Optional). Any commands necessary to enable the I2C
2533 controller or configure ports.
2535 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2539 (Only for MPC8260 CPU). The I/O port to use (the code
2540 assumes both bits are on the same port). Valid values
2541 are 0..3 for ports A..D.
2545 The code necessary to make the I2C data line active
2546 (driven). If the data line is open collector, this
2549 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2553 The code necessary to make the I2C data line tri-stated
2554 (inactive). If the data line is open collector, this
2557 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2561 Code that returns true if the I2C data line is high,
2564 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2568 If <bit> is true, sets the I2C data line high. If it
2569 is false, it clears it (low).
2571 eg: #define I2C_SDA(bit) \
2572 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2573 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2577 If <bit> is true, sets the I2C clock line high. If it
2578 is false, it clears it (low).
2580 eg: #define I2C_SCL(bit) \
2581 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2582 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2586 This delay is invoked four times per clock cycle so this
2587 controls the rate of data transfer. The data rate thus
2588 is 1 / (I2C_DELAY * 4). Often defined to be something
2591 #define I2C_DELAY udelay(2)
2593 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2595 If your arch supports the generic GPIO framework (asm/gpio.h),
2596 then you may alternatively define the two GPIOs that are to be
2597 used as SCL / SDA. Any of the previous I2C_xxx macros will
2598 have GPIO-based defaults assigned to them as appropriate.
2600 You should define these to the GPIO value as given directly to
2601 the generic GPIO functions.
2603 CONFIG_SYS_I2C_INIT_BOARD
2605 When a board is reset during an i2c bus transfer
2606 chips might think that the current transfer is still
2607 in progress. On some boards it is possible to access
2608 the i2c SCLK line directly, either by using the
2609 processor pin as a GPIO or by having a second pin
2610 connected to the bus. If this option is defined a
2611 custom i2c_init_board() routine in boards/xxx/board.c
2612 is run early in the boot sequence.
2614 CONFIG_SYS_I2C_BOARD_LATE_INIT
2616 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2617 defined a custom i2c_board_late_init() routine in
2618 boards/xxx/board.c is run AFTER the operations in i2c_init()
2619 is completed. This callpoint can be used to unreset i2c bus
2620 using CPU i2c controller register accesses for CPUs whose i2c
2621 controller provide such a method. It is called at the end of
2622 i2c_init() to allow i2c_init operations to setup the i2c bus
2623 controller on the CPU (e.g. setting bus speed & slave address).
2625 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2627 This option enables configuration of bi_iic_fast[] flags
2628 in u-boot bd_info structure based on u-boot environment
2629 variable "i2cfast". (see also i2cfast)
2631 CONFIG_I2C_MULTI_BUS
2633 This option allows the use of multiple I2C buses, each of which
2634 must have a controller. At any point in time, only one bus is
2635 active. To switch to a different bus, use the 'i2c dev' command.
2636 Note that bus numbering is zero-based.
2638 CONFIG_SYS_I2C_NOPROBES
2640 This option specifies a list of I2C devices that will be skipped
2641 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2642 is set, specify a list of bus-device pairs. Otherwise, specify
2643 a 1D array of device addresses
2646 #undef CONFIG_I2C_MULTI_BUS
2647 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2649 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2651 #define CONFIG_I2C_MULTI_BUS
2652 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2654 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2656 CONFIG_SYS_SPD_BUS_NUM
2658 If defined, then this indicates the I2C bus number for DDR SPD.
2659 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2661 CONFIG_SYS_RTC_BUS_NUM
2663 If defined, then this indicates the I2C bus number for the RTC.
2664 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2666 CONFIG_SYS_DTT_BUS_NUM
2668 If defined, then this indicates the I2C bus number for the DTT.
2669 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2671 CONFIG_SYS_I2C_DTT_ADDR:
2673 If defined, specifies the I2C address of the DTT device.
2674 If not defined, then U-Boot uses predefined value for
2675 specified DTT device.
2677 CONFIG_SOFT_I2C_READ_REPEATED_START
2679 defining this will force the i2c_read() function in
2680 the soft_i2c driver to perform an I2C repeated start
2681 between writing the address pointer and reading the
2682 data. If this define is omitted the default behaviour
2683 of doing a stop-start sequence will be used. Most I2C
2684 devices can use either method, but some require one or
2687 - SPI Support: CONFIG_SPI
2689 Enables SPI driver (so far only tested with
2690 SPI EEPROM, also an instance works with Crystal A/D and
2691 D/As on the SACSng board)
2695 Enables the driver for SPI controller on SuperH. Currently
2696 only SH7757 is supported.
2700 Enables a software (bit-bang) SPI driver rather than
2701 using hardware support. This is a general purpose
2702 driver that only requires three general I/O port pins
2703 (two outputs, one input) to function. If this is
2704 defined, the board configuration must define several
2705 SPI configuration items (port pins to use, etc). For
2706 an example, see include/configs/sacsng.h.
2710 Enables a hardware SPI driver for general-purpose reads
2711 and writes. As with CONFIG_SOFT_SPI, the board configuration
2712 must define a list of chip-select function pointers.
2713 Currently supported on some MPC8xxx processors. For an
2714 example, see include/configs/mpc8349emds.h.
2718 Enables the driver for the SPI controllers on i.MX and MXC
2719 SoCs. Currently i.MX31/35/51 are supported.
2721 CONFIG_SYS_SPI_MXC_WAIT
2722 Timeout for waiting until spi transfer completed.
2723 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2725 - FPGA Support: CONFIG_FPGA
2727 Enables FPGA subsystem.
2729 CONFIG_FPGA_<vendor>
2731 Enables support for specific chip vendors.
2734 CONFIG_FPGA_<family>
2736 Enables support for FPGA family.
2737 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2741 Specify the number of FPGA devices to support.
2743 CONFIG_CMD_FPGA_LOADMK
2745 Enable support for fpga loadmk command
2747 CONFIG_CMD_FPGA_LOADP
2749 Enable support for fpga loadp command - load partial bitstream
2751 CONFIG_CMD_FPGA_LOADBP
2753 Enable support for fpga loadbp command - load partial bitstream
2756 CONFIG_SYS_FPGA_PROG_FEEDBACK
2758 Enable printing of hash marks during FPGA configuration.
2760 CONFIG_SYS_FPGA_CHECK_BUSY
2762 Enable checks on FPGA configuration interface busy
2763 status by the configuration function. This option
2764 will require a board or device specific function to
2769 If defined, a function that provides delays in the FPGA
2770 configuration driver.
2772 CONFIG_SYS_FPGA_CHECK_CTRLC
2773 Allow Control-C to interrupt FPGA configuration
2775 CONFIG_SYS_FPGA_CHECK_ERROR
2777 Check for configuration errors during FPGA bitfile
2778 loading. For example, abort during Virtex II
2779 configuration if the INIT_B line goes low (which
2780 indicated a CRC error).
2782 CONFIG_SYS_FPGA_WAIT_INIT
2784 Maximum time to wait for the INIT_B line to de-assert
2785 after PROB_B has been de-asserted during a Virtex II
2786 FPGA configuration sequence. The default time is 500
2789 CONFIG_SYS_FPGA_WAIT_BUSY
2791 Maximum time to wait for BUSY to de-assert during
2792 Virtex II FPGA configuration. The default is 5 ms.
2794 CONFIG_SYS_FPGA_WAIT_CONFIG
2796 Time to wait after FPGA configuration. The default is
2799 - Configuration Management:
2802 Some SoCs need special image types (e.g. U-Boot binary
2803 with a special header) as build targets. By defining
2804 CONFIG_BUILD_TARGET in the SoC / board header, this
2805 special image will be automatically built upon calling
2810 If defined, this string will be added to the U-Boot
2811 version information (U_BOOT_VERSION)
2813 - Vendor Parameter Protection:
2815 U-Boot considers the values of the environment
2816 variables "serial#" (Board Serial Number) and
2817 "ethaddr" (Ethernet Address) to be parameters that
2818 are set once by the board vendor / manufacturer, and
2819 protects these variables from casual modification by
2820 the user. Once set, these variables are read-only,
2821 and write or delete attempts are rejected. You can
2822 change this behaviour:
2824 If CONFIG_ENV_OVERWRITE is #defined in your config
2825 file, the write protection for vendor parameters is
2826 completely disabled. Anybody can change or delete
2829 Alternatively, if you define _both_ an ethaddr in the
2830 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2831 Ethernet address is installed in the environment,
2832 which can be changed exactly ONCE by the user. [The
2833 serial# is unaffected by this, i. e. it remains
2836 The same can be accomplished in a more flexible way
2837 for any variable by configuring the type of access
2838 to allow for those variables in the ".flags" variable
2839 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2844 Define this variable to enable the reservation of
2845 "protected RAM", i. e. RAM which is not overwritten
2846 by U-Boot. Define CONFIG_PRAM to hold the number of
2847 kB you want to reserve for pRAM. You can overwrite
2848 this default value by defining an environment
2849 variable "pram" to the number of kB you want to
2850 reserve. Note that the board info structure will
2851 still show the full amount of RAM. If pRAM is
2852 reserved, a new environment variable "mem" will
2853 automatically be defined to hold the amount of
2854 remaining RAM in a form that can be passed as boot
2855 argument to Linux, for instance like that:
2857 setenv bootargs ... mem=\${mem}
2860 This way you can tell Linux not to use this memory,
2861 either, which results in a memory region that will
2862 not be affected by reboots.
2864 *WARNING* If your board configuration uses automatic
2865 detection of the RAM size, you must make sure that
2866 this memory test is non-destructive. So far, the
2867 following board configurations are known to be
2870 IVMS8, IVML24, SPD8xx, TQM8xxL,
2871 HERMES, IP860, RPXlite, LWMON,
2874 - Access to physical memory region (> 4GB)
2875 Some basic support is provided for operations on memory not
2876 normally accessible to U-Boot - e.g. some architectures
2877 support access to more than 4GB of memory on 32-bit
2878 machines using physical address extension or similar.
2879 Define CONFIG_PHYSMEM to access this basic support, which
2880 currently only supports clearing the memory.
2885 Define this variable to stop the system in case of a
2886 fatal error, so that you have to reset it manually.
2887 This is probably NOT a good idea for an embedded
2888 system where you want the system to reboot
2889 automatically as fast as possible, but it may be
2890 useful during development since you can try to debug
2891 the conditions that lead to the situation.
2893 CONFIG_NET_RETRY_COUNT
2895 This variable defines the number of retries for
2896 network operations like ARP, RARP, TFTP, or BOOTP
2897 before giving up the operation. If not defined, a
2898 default value of 5 is used.
2902 Timeout waiting for an ARP reply in milliseconds.
2906 Timeout in milliseconds used in NFS protocol.
2907 If you encounter "ERROR: Cannot umount" in nfs command,
2908 try longer timeout such as
2909 #define CONFIG_NFS_TIMEOUT 10000UL
2911 - Command Interpreter:
2912 CONFIG_AUTO_COMPLETE
2914 Enable auto completion of commands using TAB.
2916 CONFIG_SYS_PROMPT_HUSH_PS2
2918 This defines the secondary prompt string, which is
2919 printed when the command interpreter needs more input
2920 to complete a command. Usually "> ".
2924 In the current implementation, the local variables
2925 space and global environment variables space are
2926 separated. Local variables are those you define by
2927 simply typing `name=value'. To access a local
2928 variable later on, you have write `$name' or
2929 `${name}'; to execute the contents of a variable
2930 directly type `$name' at the command prompt.
2932 Global environment variables are those you use
2933 setenv/printenv to work with. To run a command stored
2934 in such a variable, you need to use the run command,
2935 and you must not use the '$' sign to access them.
2937 To store commands and special characters in a
2938 variable, please use double quotation marks
2939 surrounding the whole text of the variable, instead
2940 of the backslashes before semicolons and special
2943 - Command Line Editing and History:
2944 CONFIG_CMDLINE_EDITING
2946 Enable editing and History functions for interactive
2947 command line input operations
2949 - Default Environment:
2950 CONFIG_EXTRA_ENV_SETTINGS
2952 Define this to contain any number of null terminated
2953 strings (variable = value pairs) that will be part of
2954 the default environment compiled into the boot image.
2956 For example, place something like this in your
2957 board's config file:
2959 #define CONFIG_EXTRA_ENV_SETTINGS \
2963 Warning: This method is based on knowledge about the
2964 internal format how the environment is stored by the
2965 U-Boot code. This is NOT an official, exported
2966 interface! Although it is unlikely that this format
2967 will change soon, there is no guarantee either.
2968 You better know what you are doing here.
2970 Note: overly (ab)use of the default environment is
2971 discouraged. Make sure to check other ways to preset
2972 the environment like the "source" command or the
2975 CONFIG_ENV_VARS_UBOOT_CONFIG
2977 Define this in order to add variables describing the
2978 U-Boot build configuration to the default environment.
2979 These will be named arch, cpu, board, vendor, and soc.
2981 Enabling this option will cause the following to be defined:
2989 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2991 Define this in order to add variables describing certain
2992 run-time determined information about the hardware to the
2993 environment. These will be named board_name, board_rev.
2995 CONFIG_DELAY_ENVIRONMENT
2997 Normally the environment is loaded when the board is
2998 initialised so that it is available to U-Boot. This inhibits
2999 that so that the environment is not available until
3000 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3001 this is instead controlled by the value of
3002 /config/load-environment.
3004 - Parallel Flash support:
3007 Traditionally U-boot was run on systems with parallel NOR
3008 flash. This option is used to disable support for parallel NOR
3009 flash. This option should be defined if the board does not have
3012 If this option is not defined one of the generic flash drivers
3013 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3014 selected or the board must provide an implementation of the
3015 flash API (see include/flash.h).
3017 - DataFlash Support:
3018 CONFIG_HAS_DATAFLASH
3020 Defining this option enables DataFlash features and
3021 allows to read/write in Dataflash via the standard
3024 - Serial Flash support
3027 Defining this option enables SPI flash commands
3028 'sf probe/read/write/erase/update'.
3030 Usage requires an initial 'probe' to define the serial
3031 flash parameters, followed by read/write/erase/update
3034 The following defaults may be provided by the platform
3035 to handle the common case when only a single serial
3036 flash is present on the system.
3038 CONFIG_SF_DEFAULT_BUS Bus identifier
3039 CONFIG_SF_DEFAULT_CS Chip-select
3040 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3041 CONFIG_SF_DEFAULT_SPEED in Hz
3045 Define this option to include a destructive SPI flash
3048 CONFIG_SF_DUAL_FLASH Dual flash memories
3050 Define this option to use dual flash support where two flash
3051 memories can be connected with a given cs line.
3052 Currently Xilinx Zynq qspi supports these type of connections.
3054 - SystemACE Support:
3057 Adding this option adds support for Xilinx SystemACE
3058 chips attached via some sort of local bus. The address
3059 of the chip must also be defined in the
3060 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3062 #define CONFIG_SYSTEMACE
3063 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3065 When SystemACE support is added, the "ace" device type
3066 becomes available to the fat commands, i.e. fatls.
3068 - TFTP Fixed UDP Port:
3071 If this is defined, the environment variable tftpsrcp
3072 is used to supply the TFTP UDP source port value.
3073 If tftpsrcp isn't defined, the normal pseudo-random port
3074 number generator is used.
3076 Also, the environment variable tftpdstp is used to supply
3077 the TFTP UDP destination port value. If tftpdstp isn't
3078 defined, the normal port 69 is used.
3080 The purpose for tftpsrcp is to allow a TFTP server to
3081 blindly start the TFTP transfer using the pre-configured
3082 target IP address and UDP port. This has the effect of
3083 "punching through" the (Windows XP) firewall, allowing
3084 the remainder of the TFTP transfer to proceed normally.
3085 A better solution is to properly configure the firewall,
3086 but sometimes that is not allowed.
3091 This enables a generic 'hash' command which can produce
3092 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3096 Enable the hash verify command (hash -v). This adds to code
3099 CONFIG_SHA1 - This option enables support of hashing using SHA1
3100 algorithm. The hash is calculated in software.
3101 CONFIG_SHA256 - This option enables support of hashing using
3102 SHA256 algorithm. The hash is calculated in software.
3103 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3104 for SHA1/SHA256 hashing.
3105 This affects the 'hash' command and also the
3106 hash_lookup_algo() function.
3107 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3108 hardware-acceleration for SHA1/SHA256 progressive hashing.
3109 Data can be streamed in a block at a time and the hashing
3110 is performed in hardware.
3112 Note: There is also a sha1sum command, which should perhaps
3113 be deprecated in favour of 'hash sha1'.
3115 - Freescale i.MX specific commands:
3116 CONFIG_CMD_HDMIDETECT
3117 This enables 'hdmidet' command which returns true if an
3118 HDMI monitor is detected. This command is i.MX 6 specific.
3121 This enables the 'bmode' (bootmode) command for forcing
3122 a boot from specific media.
3124 This is useful for forcing the ROM's usb downloader to
3125 activate upon a watchdog reset which is nice when iterating
3126 on U-Boot. Using the reset button or running bmode normal
3127 will set it back to normal. This command currently
3128 supports i.MX53 and i.MX6.
3133 This enables the RSA algorithm used for FIT image verification
3134 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3136 The Modular Exponentiation algorithm in RSA is implemented using
3137 driver model. So CONFIG_DM needs to be enabled by default for this
3138 library to function.
3140 The signing part is build into mkimage regardless of this
3141 option. The software based modular exponentiation is built into
3142 mkimage irrespective of this option.
3144 - bootcount support:
3145 CONFIG_BOOTCOUNT_LIMIT
3147 This enables the bootcounter support, see:
3148 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3151 enable special bootcounter support on at91sam9xe based boards.
3153 enable special bootcounter support on blackfin based boards.
3155 enable special bootcounter support on da850 based boards.
3156 CONFIG_BOOTCOUNT_RAM
3157 enable support for the bootcounter in RAM
3158 CONFIG_BOOTCOUNT_I2C
3159 enable support for the bootcounter on an i2c (like RTC) device.
3160 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3161 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3163 CONFIG_BOOTCOUNT_ALEN = address len
3165 - Show boot progress:
3166 CONFIG_SHOW_BOOT_PROGRESS
3168 Defining this option allows to add some board-
3169 specific code (calling a user-provided function
3170 "show_boot_progress(int)") that enables you to show
3171 the system's boot progress on some display (for
3172 example, some LED's) on your board. At the moment,
3173 the following checkpoints are implemented:
3176 Legacy uImage format:
3179 1 common/cmd_bootm.c before attempting to boot an image
3180 -1 common/cmd_bootm.c Image header has bad magic number
3181 2 common/cmd_bootm.c Image header has correct magic number
3182 -2 common/cmd_bootm.c Image header has bad checksum
3183 3 common/cmd_bootm.c Image header has correct checksum
3184 -3 common/cmd_bootm.c Image data has bad checksum
3185 4 common/cmd_bootm.c Image data has correct checksum
3186 -4 common/cmd_bootm.c Image is for unsupported architecture
3187 5 common/cmd_bootm.c Architecture check OK
3188 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3189 6 common/cmd_bootm.c Image Type check OK
3190 -6 common/cmd_bootm.c gunzip uncompression error
3191 -7 common/cmd_bootm.c Unimplemented compression type
3192 7 common/cmd_bootm.c Uncompression OK
3193 8 common/cmd_bootm.c No uncompress/copy overwrite error
3194 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3196 9 common/image.c Start initial ramdisk verification
3197 -10 common/image.c Ramdisk header has bad magic number
3198 -11 common/image.c Ramdisk header has bad checksum
3199 10 common/image.c Ramdisk header is OK
3200 -12 common/image.c Ramdisk data has bad checksum
3201 11 common/image.c Ramdisk data has correct checksum
3202 12 common/image.c Ramdisk verification complete, start loading
3203 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3204 13 common/image.c Start multifile image verification
3205 14 common/image.c No initial ramdisk, no multifile, continue.
3207 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3209 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3210 -31 post/post.c POST test failed, detected by post_output_backlog()
3211 -32 post/post.c POST test failed, detected by post_run_single()
3213 34 common/cmd_doc.c before loading a Image from a DOC device
3214 -35 common/cmd_doc.c Bad usage of "doc" command
3215 35 common/cmd_doc.c correct usage of "doc" command
3216 -36 common/cmd_doc.c No boot device
3217 36 common/cmd_doc.c correct boot device
3218 -37 common/cmd_doc.c Unknown Chip ID on boot device
3219 37 common/cmd_doc.c correct chip ID found, device available
3220 -38 common/cmd_doc.c Read Error on boot device
3221 38 common/cmd_doc.c reading Image header from DOC device OK
3222 -39 common/cmd_doc.c Image header has bad magic number
3223 39 common/cmd_doc.c Image header has correct magic number
3224 -40 common/cmd_doc.c Error reading Image from DOC device
3225 40 common/cmd_doc.c Image header has correct magic number
3226 41 common/cmd_ide.c before loading a Image from a IDE device
3227 -42 common/cmd_ide.c Bad usage of "ide" command
3228 42 common/cmd_ide.c correct usage of "ide" command
3229 -43 common/cmd_ide.c No boot device
3230 43 common/cmd_ide.c boot device found
3231 -44 common/cmd_ide.c Device not available
3232 44 common/cmd_ide.c Device available
3233 -45 common/cmd_ide.c wrong partition selected
3234 45 common/cmd_ide.c partition selected
3235 -46 common/cmd_ide.c Unknown partition table
3236 46 common/cmd_ide.c valid partition table found
3237 -47 common/cmd_ide.c Invalid partition type
3238 47 common/cmd_ide.c correct partition type
3239 -48 common/cmd_ide.c Error reading Image Header on boot device
3240 48 common/cmd_ide.c reading Image Header from IDE device OK
3241 -49 common/cmd_ide.c Image header has bad magic number
3242 49 common/cmd_ide.c Image header has correct magic number
3243 -50 common/cmd_ide.c Image header has bad checksum
3244 50 common/cmd_ide.c Image header has correct checksum
3245 -51 common/cmd_ide.c Error reading Image from IDE device
3246 51 common/cmd_ide.c reading Image from IDE device OK
3247 52 common/cmd_nand.c before loading a Image from a NAND device
3248 -53 common/cmd_nand.c Bad usage of "nand" command
3249 53 common/cmd_nand.c correct usage of "nand" command
3250 -54 common/cmd_nand.c No boot device
3251 54 common/cmd_nand.c boot device found
3252 -55 common/cmd_nand.c Unknown Chip ID on boot device
3253 55 common/cmd_nand.c correct chip ID found, device available
3254 -56 common/cmd_nand.c Error reading Image Header on boot device
3255 56 common/cmd_nand.c reading Image Header from NAND device OK
3256 -57 common/cmd_nand.c Image header has bad magic number
3257 57 common/cmd_nand.c Image header has correct magic number
3258 -58 common/cmd_nand.c Error reading Image from NAND device
3259 58 common/cmd_nand.c reading Image from NAND device OK
3261 -60 common/env_common.c Environment has a bad CRC, using default
3263 64 net/eth.c starting with Ethernet configuration.
3264 -64 net/eth.c no Ethernet found.
3265 65 net/eth.c Ethernet found.
3267 -80 common/cmd_net.c usage wrong
3268 80 common/cmd_net.c before calling net_loop()
3269 -81 common/cmd_net.c some error in net_loop() occurred
3270 81 common/cmd_net.c net_loop() back without error
3271 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3272 82 common/cmd_net.c trying automatic boot
3273 83 common/cmd_net.c running "source" command
3274 -83 common/cmd_net.c some error in automatic boot or "source" command
3275 84 common/cmd_net.c end without errors
3280 100 common/cmd_bootm.c Kernel FIT Image has correct format
3281 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3282 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3283 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3284 102 common/cmd_bootm.c Kernel unit name specified
3285 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3286 103 common/cmd_bootm.c Found configuration node
3287 104 common/cmd_bootm.c Got kernel subimage node offset
3288 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3289 105 common/cmd_bootm.c Kernel subimage hash verification OK
3290 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3291 106 common/cmd_bootm.c Architecture check OK
3292 -106 common/cmd_bootm.c Kernel subimage has wrong type
3293 107 common/cmd_bootm.c Kernel subimage type OK
3294 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3295 108 common/cmd_bootm.c Got kernel subimage data/size
3296 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3297 -109 common/cmd_bootm.c Can't get kernel subimage type
3298 -110 common/cmd_bootm.c Can't get kernel subimage comp
3299 -111 common/cmd_bootm.c Can't get kernel subimage os
3300 -112 common/cmd_bootm.c Can't get kernel subimage load address
3301 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3303 120 common/image.c Start initial ramdisk verification
3304 -120 common/image.c Ramdisk FIT image has incorrect format
3305 121 common/image.c Ramdisk FIT image has correct format
3306 122 common/image.c No ramdisk subimage unit name, using configuration
3307 -122 common/image.c Can't get configuration for ramdisk subimage
3308 123 common/image.c Ramdisk unit name specified
3309 -124 common/image.c Can't get ramdisk subimage node offset
3310 125 common/image.c Got ramdisk subimage node offset
3311 -125 common/image.c Ramdisk subimage hash verification failed
3312 126 common/image.c Ramdisk subimage hash verification OK
3313 -126 common/image.c Ramdisk subimage for unsupported architecture
3314 127 common/image.c Architecture check OK
3315 -127 common/image.c Can't get ramdisk subimage data/size
3316 128 common/image.c Got ramdisk subimage data/size
3317 129 common/image.c Can't get ramdisk load address
3318 -129 common/image.c Got ramdisk load address
3320 -130 common/cmd_doc.c Incorrect FIT image format
3321 131 common/cmd_doc.c FIT image format OK
3323 -140 common/cmd_ide.c Incorrect FIT image format
3324 141 common/cmd_ide.c FIT image format OK
3326 -150 common/cmd_nand.c Incorrect FIT image format
3327 151 common/cmd_nand.c FIT image format OK
3329 - legacy image format:
3330 CONFIG_IMAGE_FORMAT_LEGACY
3331 enables the legacy image format support in U-Boot.
3334 enabled if CONFIG_FIT_SIGNATURE is not defined.
3336 CONFIG_DISABLE_IMAGE_LEGACY
3337 disable the legacy image format
3339 This define is introduced, as the legacy image format is
3340 enabled per default for backward compatibility.
3342 - FIT image support:
3344 Enable support for the FIT uImage format.
3346 CONFIG_FIT_BEST_MATCH
3347 When no configuration is explicitly selected, default to the
3348 one whose fdt's compatibility field best matches that of
3349 U-Boot itself. A match is considered "best" if it matches the
3350 most specific compatibility entry of U-Boot's fdt's root node.
3351 The order of entries in the configuration's fdt is ignored.
3353 CONFIG_FIT_SIGNATURE
3354 This option enables signature verification of FIT uImages,
3355 using a hash signed and verified using RSA. If
3356 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3357 hashing is available using hardware, RSA library will use it.
3358 See doc/uImage.FIT/signature.txt for more details.
3360 WARNING: When relying on signed FIT images with required
3361 signature check the legacy image format is default
3362 disabled. If a board need legacy image format support
3363 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3365 CONFIG_FIT_DISABLE_SHA256
3366 Supporting SHA256 hashes has quite an impact on binary size.
3367 For constrained systems sha256 hash support can be disabled
3370 - Standalone program support:
3371 CONFIG_STANDALONE_LOAD_ADDR
3373 This option defines a board specific value for the
3374 address where standalone program gets loaded, thus
3375 overwriting the architecture dependent default
3378 - Frame Buffer Address:
3381 Define CONFIG_FB_ADDR if you want to use specific
3382 address for frame buffer. This is typically the case
3383 when using a graphics controller has separate video
3384 memory. U-Boot will then place the frame buffer at
3385 the given address instead of dynamically reserving it
3386 in system RAM by calling lcd_setmem(), which grabs
3387 the memory for the frame buffer depending on the
3388 configured panel size.
3390 Please see board_init_f function.
3392 - Automatic software updates via TFTP server
3394 CONFIG_UPDATE_TFTP_CNT_MAX
3395 CONFIG_UPDATE_TFTP_MSEC_MAX
3397 These options enable and control the auto-update feature;
3398 for a more detailed description refer to doc/README.update.
3400 - MTD Support (mtdparts command, UBI support)
3403 Adds the MTD device infrastructure from the Linux kernel.
3404 Needed for mtdparts command support.
3406 CONFIG_MTD_PARTITIONS
3408 Adds the MTD partitioning infrastructure from the Linux
3409 kernel. Needed for UBI support.
3414 Adds commands for interacting with MTD partitions formatted
3415 with the UBI flash translation layer
3417 Requires also defining CONFIG_RBTREE
3419 CONFIG_UBI_SILENCE_MSG
3421 Make the verbose messages from UBI stop printing. This leaves
3422 warnings and errors enabled.
3425 CONFIG_MTD_UBI_WL_THRESHOLD
3426 This parameter defines the maximum difference between the highest
3427 erase counter value and the lowest erase counter value of eraseblocks
3428 of UBI devices. When this threshold is exceeded, UBI starts performing
3429 wear leveling by means of moving data from eraseblock with low erase
3430 counter to eraseblocks with high erase counter.
3432 The default value should be OK for SLC NAND flashes, NOR flashes and
3433 other flashes which have eraseblock life-cycle 100000 or more.
3434 However, in case of MLC NAND flashes which typically have eraseblock
3435 life-cycle less than 10000, the threshold should be lessened (e.g.,
3436 to 128 or 256, although it does not have to be power of 2).
3440 CONFIG_MTD_UBI_BEB_LIMIT
3441 This option specifies the maximum bad physical eraseblocks UBI
3442 expects on the MTD device (per 1024 eraseblocks). If the
3443 underlying flash does not admit of bad eraseblocks (e.g. NOR
3444 flash), this value is ignored.
3446 NAND datasheets often specify the minimum and maximum NVM
3447 (Number of Valid Blocks) for the flashes' endurance lifetime.
3448 The maximum expected bad eraseblocks per 1024 eraseblocks
3449 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3450 which gives 20 for most NANDs (MaxNVB is basically the total
3451 count of eraseblocks on the chip).
3453 To put it differently, if this value is 20, UBI will try to
3454 reserve about 1.9% of physical eraseblocks for bad blocks
3455 handling. And that will be 1.9% of eraseblocks on the entire
3456 NAND chip, not just the MTD partition UBI attaches. This means
3457 that if you have, say, a NAND flash chip admits maximum 40 bad
3458 eraseblocks, and it is split on two MTD partitions of the same
3459 size, UBI will reserve 40 eraseblocks when attaching a
3464 CONFIG_MTD_UBI_FASTMAP
3465 Fastmap is a mechanism which allows attaching an UBI device
3466 in nearly constant time. Instead of scanning the whole MTD device it
3467 only has to locate a checkpoint (called fastmap) on the device.
3468 The on-flash fastmap contains all information needed to attach
3469 the device. Using fastmap makes only sense on large devices where
3470 attaching by scanning takes long. UBI will not automatically install
3471 a fastmap on old images, but you can set the UBI parameter
3472 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3473 that fastmap-enabled images are still usable with UBI implementations
3474 without fastmap support. On typical flash devices the whole fastmap
3475 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3477 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3478 Set this parameter to enable fastmap automatically on images
3482 CONFIG_MTD_UBI_FM_DEBUG
3483 Enable UBI fastmap debug
3489 Adds commands for interacting with UBI volumes formatted as
3490 UBIFS. UBIFS is read-only in u-boot.
3492 Requires UBI support as well as CONFIG_LZO
3494 CONFIG_UBIFS_SILENCE_MSG
3496 Make the verbose messages from UBIFS stop printing. This leaves
3497 warnings and errors enabled.
3501 Enable building of SPL globally.
3504 LDSCRIPT for linking the SPL binary.
3506 CONFIG_SPL_MAX_FOOTPRINT
3507 Maximum size in memory allocated to the SPL, BSS included.
3508 When defined, the linker checks that the actual memory
3509 used by SPL from _start to __bss_end does not exceed it.
3510 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3511 must not be both defined at the same time.
3514 Maximum size of the SPL image (text, data, rodata, and
3515 linker lists sections), BSS excluded.
3516 When defined, the linker checks that the actual size does
3519 CONFIG_SPL_TEXT_BASE
3520 TEXT_BASE for linking the SPL binary.
3522 CONFIG_SPL_RELOC_TEXT_BASE
3523 Address to relocate to. If unspecified, this is equal to
3524 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3526 CONFIG_SPL_BSS_START_ADDR
3527 Link address for the BSS within the SPL binary.
3529 CONFIG_SPL_BSS_MAX_SIZE
3530 Maximum size in memory allocated to the SPL BSS.
3531 When defined, the linker checks that the actual memory used
3532 by SPL from __bss_start to __bss_end does not exceed it.
3533 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3534 must not be both defined at the same time.
3537 Adress of the start of the stack SPL will use
3539 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3540 When defined, SPL will panic() if the image it has
3541 loaded does not have a signature.
3542 Defining this is useful when code which loads images
3543 in SPL cannot guarantee that absolutely all read errors
3545 An example is the LPC32XX MLC NAND driver, which will
3546 consider that a completely unreadable NAND block is bad,
3547 and thus should be skipped silently.
3549 CONFIG_SPL_RELOC_STACK
3550 Adress of the start of the stack SPL will use after
3551 relocation. If unspecified, this is equal to
3554 CONFIG_SYS_SPL_MALLOC_START
3555 Starting address of the malloc pool used in SPL.
3556 When this option is set the full malloc is used in SPL and
3557 it is set up by spl_init() and before that, the simple malloc()
3558 can be used if CONFIG_SYS_MALLOC_F is defined.
3560 CONFIG_SYS_SPL_MALLOC_SIZE
3561 The size of the malloc pool used in SPL.
3563 CONFIG_SPL_FRAMEWORK
3564 Enable the SPL framework under common/. This framework
3565 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3566 NAND loading of the Linux Kernel.
3569 Enable booting directly to an OS from SPL.
3570 See also: doc/README.falcon
3572 CONFIG_SPL_DISPLAY_PRINT
3573 For ARM, enable an optional function to print more information
3574 about the running system.
3576 CONFIG_SPL_INIT_MINIMAL
3577 Arch init code should be built for a very small image
3579 CONFIG_SPL_LIBCOMMON_SUPPORT
3580 Support for common/libcommon.o in SPL binary
3582 CONFIG_SPL_LIBDISK_SUPPORT
3583 Support for disk/libdisk.o in SPL binary
3585 CONFIG_SPL_I2C_SUPPORT
3586 Support for drivers/i2c/libi2c.o in SPL binary
3588 CONFIG_SPL_GPIO_SUPPORT
3589 Support for drivers/gpio/libgpio.o in SPL binary
3591 CONFIG_SPL_MMC_SUPPORT
3592 Support for drivers/mmc/libmmc.o in SPL binary
3594 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3595 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3596 Address and partition on the MMC to load U-Boot from
3597 when the MMC is being used in raw mode.
3599 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3600 Partition on the MMC to load U-Boot from when the MMC is being
3603 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3604 Sector to load kernel uImage from when MMC is being
3605 used in raw mode (for Falcon mode)
3607 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3608 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3609 Sector and number of sectors to load kernel argument
3610 parameters from when MMC is being used in raw mode
3613 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3614 Partition on the MMC to load U-Boot from when the MMC is being
3617 CONFIG_SPL_FAT_SUPPORT
3618 Support for fs/fat/libfat.o in SPL binary
3620 CONFIG_SPL_EXT_SUPPORT
3621 Support for EXT filesystem in SPL binary
3623 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3624 Filename to read to load U-Boot when reading from filesystem
3626 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3627 Filename to read to load kernel uImage when reading
3628 from filesystem (for Falcon mode)
3630 CONFIG_SPL_FS_LOAD_ARGS_NAME
3631 Filename to read to load kernel argument parameters
3632 when reading from filesystem (for Falcon mode)
3634 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3635 Set this for NAND SPL on PPC mpc83xx targets, so that
3636 start.S waits for the rest of the SPL to load before
3637 continuing (the hardware starts execution after just
3638 loading the first page rather than the full 4K).
3640 CONFIG_SPL_SKIP_RELOCATE
3641 Avoid SPL relocation
3643 CONFIG_SPL_NAND_BASE
3644 Include nand_base.c in the SPL. Requires
3645 CONFIG_SPL_NAND_DRIVERS.
3647 CONFIG_SPL_NAND_DRIVERS
3648 SPL uses normal NAND drivers, not minimal drivers.
3651 Include standard software ECC in the SPL
3653 CONFIG_SPL_NAND_SIMPLE
3654 Support for NAND boot using simple NAND drivers that
3655 expose the cmd_ctrl() interface.
3657 CONFIG_SPL_MTD_SUPPORT
3658 Support for the MTD subsystem within SPL. Useful for
3659 environment on NAND support within SPL.
3661 CONFIG_SPL_NAND_RAW_ONLY
3662 Support to boot only raw u-boot.bin images. Use this only
3663 if you need to save space.
3665 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3666 Set for the SPL on PPC mpc8xxx targets, support for
3667 drivers/ddr/fsl/libddr.o in SPL binary.
3669 CONFIG_SPL_COMMON_INIT_DDR
3670 Set for common ddr init with serial presence detect in
3673 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3674 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3675 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3676 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3677 CONFIG_SYS_NAND_ECCBYTES
3678 Defines the size and behavior of the NAND that SPL uses
3681 CONFIG_SPL_NAND_BOOT
3682 Add support NAND boot
3684 CONFIG_SYS_NAND_U_BOOT_OFFS
3685 Location in NAND to read U-Boot from
3687 CONFIG_SYS_NAND_U_BOOT_DST
3688 Location in memory to load U-Boot to
3690 CONFIG_SYS_NAND_U_BOOT_SIZE
3691 Size of image to load
3693 CONFIG_SYS_NAND_U_BOOT_START
3694 Entry point in loaded image to jump to
3696 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3697 Define this if you need to first read the OOB and then the
3698 data. This is used, for example, on davinci platforms.
3700 CONFIG_SPL_OMAP3_ID_NAND
3701 Support for an OMAP3-specific set of functions to return the
3702 ID and MFR of the first attached NAND chip, if present.
3704 CONFIG_SPL_SERIAL_SUPPORT
3705 Support for drivers/serial/libserial.o in SPL binary
3707 CONFIG_SPL_SPI_FLASH_SUPPORT
3708 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3710 CONFIG_SPL_SPI_SUPPORT
3711 Support for drivers/spi/libspi.o in SPL binary
3713 CONFIG_SPL_RAM_DEVICE
3714 Support for running image already present in ram, in SPL binary
3716 CONFIG_SPL_LIBGENERIC_SUPPORT
3717 Support for lib/libgeneric.o in SPL binary
3719 CONFIG_SPL_ENV_SUPPORT
3720 Support for the environment operating in SPL binary
3722 CONFIG_SPL_NET_SUPPORT
3723 Support for the net/libnet.o in SPL binary.
3724 It conflicts with SPL env from storage medium specified by
3725 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3728 Image offset to which the SPL should be padded before appending
3729 the SPL payload. By default, this is defined as
3730 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3731 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3732 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3735 Final target image containing SPL and payload. Some SPLs
3736 use an arch-specific makefile fragment instead, for
3737 example if more than one image needs to be produced.
3739 CONFIG_FIT_SPL_PRINT
3740 Printing information about a FIT image adds quite a bit of
3741 code to SPL. So this is normally disabled in SPL. Use this
3742 option to re-enable it. This will affect the output of the
3743 bootm command when booting a FIT image.
3747 Enable building of TPL globally.
3750 Image offset to which the TPL should be padded before appending
3751 the TPL payload. By default, this is defined as
3752 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3753 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3754 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3759 [so far only for SMDK2400 boards]
3761 - Modem support enable:
3762 CONFIG_MODEM_SUPPORT
3764 - RTS/CTS Flow control enable:
3767 - Modem debug support:
3768 CONFIG_MODEM_SUPPORT_DEBUG
3770 Enables debugging stuff (char screen[1024], dbg())
3771 for modem support. Useful only with BDI2000.
3773 - Interrupt support (PPC):
3775 There are common interrupt_init() and timer_interrupt()
3776 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3777 for CPU specific initialization. interrupt_init_cpu()
3778 should set decrementer_count to appropriate value. If
3779 CPU resets decrementer automatically after interrupt
3780 (ppc4xx) it should set decrementer_count to zero.
3781 timer_interrupt() calls timer_interrupt_cpu() for CPU
3782 specific handling. If board has watchdog / status_led
3783 / other_activity_monitor it works automatically from
3784 general timer_interrupt().
3788 In the target system modem support is enabled when a
3789 specific key (key combination) is pressed during
3790 power-on. Otherwise U-Boot will boot normally
3791 (autoboot). The key_pressed() function is called from
3792 board_init(). Currently key_pressed() is a dummy
3793 function, returning 1 and thus enabling modem
3796 If there are no modem init strings in the
3797 environment, U-Boot proceed to autoboot; the
3798 previous output (banner, info printfs) will be
3801 See also: doc/README.Modem
3803 Board initialization settings:
3804 ------------------------------
3806 During Initialization u-boot calls a number of board specific functions
3807 to allow the preparation of board specific prerequisites, e.g. pin setup
3808 before drivers are initialized. To enable these callbacks the
3809 following configuration macros have to be defined. Currently this is
3810 architecture specific, so please check arch/your_architecture/lib/board.c
3811 typically in board_init_f() and board_init_r().
3813 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3814 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3815 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3816 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3818 Configuration Settings:
3819 -----------------------
3821 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3822 Optionally it can be defined to support 64-bit memory commands.
3824 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3825 undefine this when you're short of memory.
3827 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3828 width of the commands listed in the 'help' command output.
3830 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3831 prompt for user input.
3833 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3835 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3837 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3839 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3840 the application (usually a Linux kernel) when it is
3843 - CONFIG_SYS_BAUDRATE_TABLE:
3844 List of legal baudrate settings for this board.
3846 - CONFIG_SYS_CONSOLE_INFO_QUIET
3847 Suppress display of console information at boot.
3849 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3850 If the board specific function
3851 extern int overwrite_console (void);
3852 returns 1, the stdin, stderr and stdout are switched to the
3853 serial port, else the settings in the environment are used.
3855 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3856 Enable the call to overwrite_console().
3858 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3859 Enable overwrite of previous console environment settings.
3861 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3862 Begin and End addresses of the area used by the
3865 - CONFIG_SYS_ALT_MEMTEST:
3866 Enable an alternate, more extensive memory test.
3868 - CONFIG_SYS_MEMTEST_SCRATCH:
3869 Scratch address used by the alternate memory test
3870 You only need to set this if address zero isn't writeable
3872 - CONFIG_SYS_MEM_RESERVE_SECURE
3873 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3874 is substracted from total RAM and won't be reported to OS.
3875 This memory can be used as secure memory. A variable
3876 gd->secure_ram is used to track the location. In systems
3877 the RAM base is not zero, or RAM is divided into banks,
3878 this variable needs to be recalcuated to get the address.
3880 - CONFIG_SYS_MEM_TOP_HIDE:
3881 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3882 this specified memory area will get subtracted from the top
3883 (end) of RAM and won't get "touched" at all by U-Boot. By
3884 fixing up gd->ram_size the Linux kernel should gets passed
3885 the now "corrected" memory size and won't touch it either.
3886 This should work for arch/ppc and arch/powerpc. Only Linux
3887 board ports in arch/powerpc with bootwrapper support that
3888 recalculate the memory size from the SDRAM controller setup
3889 will have to get fixed in Linux additionally.
3891 This option can be used as a workaround for the 440EPx/GRx
3892 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3895 WARNING: Please make sure that this value is a multiple of
3896 the Linux page size (normally 4k). If this is not the case,
3897 then the end address of the Linux memory will be located at a
3898 non page size aligned address and this could cause major
3901 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3902 Enable temporary baudrate change while serial download
3904 - CONFIG_SYS_SDRAM_BASE:
3905 Physical start address of SDRAM. _Must_ be 0 here.
3907 - CONFIG_SYS_MBIO_BASE:
3908 Physical start address of Motherboard I/O (if using a
3911 - CONFIG_SYS_FLASH_BASE:
3912 Physical start address of Flash memory.
3914 - CONFIG_SYS_MONITOR_BASE:
3915 Physical start address of boot monitor code (set by
3916 make config files to be same as the text base address
3917 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3918 CONFIG_SYS_FLASH_BASE when booting from flash.
3920 - CONFIG_SYS_MONITOR_LEN:
3921 Size of memory reserved for monitor code, used to
3922 determine _at_compile_time_ (!) if the environment is
3923 embedded within the U-Boot image, or in a separate
3926 - CONFIG_SYS_MALLOC_LEN:
3927 Size of DRAM reserved for malloc() use.
3929 - CONFIG_SYS_MALLOC_F_LEN
3930 Size of the malloc() pool for use before relocation. If
3931 this is defined, then a very simple malloc() implementation
3932 will become available before relocation. The address is just
3933 below the global data, and the stack is moved down to make
3936 This feature allocates regions with increasing addresses
3937 within the region. calloc() is supported, but realloc()
3938 is not available. free() is supported but does nothing.
3939 The memory will be freed (or in fact just forgotten) when
3940 U-Boot relocates itself.
3942 Pre-relocation malloc() is only supported on ARM and sandbox
3943 at present but is fairly easy to enable for other archs.
3945 - CONFIG_SYS_MALLOC_SIMPLE
3946 Provides a simple and small malloc() and calloc() for those
3947 boards which do not use the full malloc in SPL (which is
3948 enabled with CONFIG_SYS_SPL_MALLOC_START).
3950 - CONFIG_SYS_NONCACHED_MEMORY:
3951 Size of non-cached memory area. This area of memory will be
3952 typically located right below the malloc() area and mapped
3953 uncached in the MMU. This is useful for drivers that would
3954 otherwise require a lot of explicit cache maintenance. For
3955 some drivers it's also impossible to properly maintain the
3956 cache. For example if the regions that need to be flushed
3957 are not a multiple of the cache-line size, *and* padding
3958 cannot be allocated between the regions to align them (i.e.
3959 if the HW requires a contiguous array of regions, and the
3960 size of each region is not cache-aligned), then a flush of
3961 one region may result in overwriting data that hardware has
3962 written to another region in the same cache-line. This can
3963 happen for example in network drivers where descriptors for
3964 buffers are typically smaller than the CPU cache-line (e.g.
3965 16 bytes vs. 32 or 64 bytes).
3967 Non-cached memory is only supported on 32-bit ARM at present.
3969 - CONFIG_SYS_BOOTM_LEN:
3970 Normally compressed uImages are limited to an
3971 uncompressed size of 8 MBytes. If this is not enough,
3972 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3973 to adjust this setting to your needs.
3975 - CONFIG_SYS_BOOTMAPSZ:
3976 Maximum size of memory mapped by the startup code of
3977 the Linux kernel; all data that must be processed by
3978 the Linux kernel (bd_info, boot arguments, FDT blob if
3979 used) must be put below this limit, unless "bootm_low"
3980 environment variable is defined and non-zero. In such case
3981 all data for the Linux kernel must be between "bootm_low"
3982 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3983 variable "bootm_mapsize" will override the value of
3984 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3985 then the value in "bootm_size" will be used instead.
3987 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3988 Enable initrd_high functionality. If defined then the
3989 initrd_high feature is enabled and the bootm ramdisk subcommand
3992 - CONFIG_SYS_BOOT_GET_CMDLINE:
3993 Enables allocating and saving kernel cmdline in space between
3994 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3996 - CONFIG_SYS_BOOT_GET_KBD:
3997 Enables allocating and saving a kernel copy of the bd_info in
3998 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4000 - CONFIG_SYS_MAX_FLASH_BANKS:
4001 Max number of Flash memory banks
4003 - CONFIG_SYS_MAX_FLASH_SECT:
4004 Max number of sectors on a Flash chip
4006 - CONFIG_SYS_FLASH_ERASE_TOUT:
4007 Timeout for Flash erase operations (in ms)
4009 - CONFIG_SYS_FLASH_WRITE_TOUT:
4010 Timeout for Flash write operations (in ms)
4012 - CONFIG_SYS_FLASH_LOCK_TOUT
4013 Timeout for Flash set sector lock bit operation (in ms)
4015 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4016 Timeout for Flash clear lock bits operation (in ms)
4018 - CONFIG_SYS_FLASH_PROTECTION
4019 If defined, hardware flash sectors protection is used
4020 instead of U-Boot software protection.
4022 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4024 Enable TFTP transfers directly to flash memory;
4025 without this option such a download has to be
4026 performed in two steps: (1) download to RAM, and (2)
4027 copy from RAM to flash.
4029 The two-step approach is usually more reliable, since
4030 you can check if the download worked before you erase
4031 the flash, but in some situations (when system RAM is
4032 too limited to allow for a temporary copy of the
4033 downloaded image) this option may be very useful.
4035 - CONFIG_SYS_FLASH_CFI:
4036 Define if the flash driver uses extra elements in the
4037 common flash structure for storing flash geometry.
4039 - CONFIG_FLASH_CFI_DRIVER
4040 This option also enables the building of the cfi_flash driver
4041 in the drivers directory
4043 - CONFIG_FLASH_CFI_MTD
4044 This option enables the building of the cfi_mtd driver
4045 in the drivers directory. The driver exports CFI flash
4048 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4049 Use buffered writes to flash.
4051 - CONFIG_FLASH_SPANSION_S29WS_N
4052 s29ws-n MirrorBit flash has non-standard addresses for buffered
4055 - CONFIG_SYS_FLASH_QUIET_TEST
4056 If this option is defined, the common CFI flash doesn't
4057 print it's warning upon not recognized FLASH banks. This
4058 is useful, if some of the configured banks are only
4059 optionally available.
4061 - CONFIG_FLASH_SHOW_PROGRESS
4062 If defined (must be an integer), print out countdown
4063 digits and dots. Recommended value: 45 (9..1) for 80
4064 column displays, 15 (3..1) for 40 column displays.
4066 - CONFIG_FLASH_VERIFY
4067 If defined, the content of the flash (destination) is compared
4068 against the source after the write operation. An error message
4069 will be printed when the contents are not identical.
4070 Please note that this option is useless in nearly all cases,
4071 since such flash programming errors usually are detected earlier
4072 while unprotecting/erasing/programming. Please only enable
4073 this option if you really know what you are doing.
4075 - CONFIG_SYS_RX_ETH_BUFFER:
4076 Defines the number of Ethernet receive buffers. On some
4077 Ethernet controllers it is recommended to set this value
4078 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4079 buffers can be full shortly after enabling the interface
4080 on high Ethernet traffic.
4081 Defaults to 4 if not defined.
4083 - CONFIG_ENV_MAX_ENTRIES
4085 Maximum number of entries in the hash table that is used
4086 internally to store the environment settings. The default
4087 setting is supposed to be generous and should work in most
4088 cases. This setting can be used to tune behaviour; see
4089 lib/hashtable.c for details.
4091 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4092 - CONFIG_ENV_FLAGS_LIST_STATIC
4093 Enable validation of the values given to environment variables when
4094 calling env set. Variables can be restricted to only decimal,
4095 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4096 the variables can also be restricted to IP address or MAC address.
4098 The format of the list is:
4099 type_attribute = [s|d|x|b|i|m]
4100 access_attribute = [a|r|o|c]
4101 attributes = type_attribute[access_attribute]
4102 entry = variable_name[:attributes]
4105 The type attributes are:
4106 s - String (default)
4109 b - Boolean ([1yYtT|0nNfF])
4113 The access attributes are:
4119 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4120 Define this to a list (string) to define the ".flags"
4121 environment variable in the default or embedded environment.
4123 - CONFIG_ENV_FLAGS_LIST_STATIC
4124 Define this to a list (string) to define validation that
4125 should be done if an entry is not found in the ".flags"
4126 environment variable. To override a setting in the static
4127 list, simply add an entry for the same variable name to the
4130 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4131 regular expression. This allows multiple variables to define the same
4132 flags without explicitly listing them for each variable.
4134 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4135 If defined, don't allow the -f switch to env set override variable
4138 - CONFIG_SYS_GENERIC_BOARD
4139 This selects the architecture-generic board system instead of the
4140 architecture-specific board files. It is intended to move boards
4141 to this new framework over time. Defining this will disable the
4142 arch/foo/lib/board.c file and use common/board_f.c and
4143 common/board_r.c instead. To use this option your architecture
4144 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4145 If you find problems enabling this option on your board please report
4146 the problem and send patches!
4148 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4149 This is set by OMAP boards for the max time that reset should
4150 be asserted. See doc/README.omap-reset-time for details on how
4151 the value can be calculated on a given board.
4154 If stdint.h is available with your toolchain you can define this
4155 option to enable it. You can provide option 'USE_STDINT=1' when
4156 building U-Boot to enable this.
4158 The following definitions that deal with the placement and management
4159 of environment data (variable area); in general, we support the
4160 following configurations:
4162 - CONFIG_BUILD_ENVCRC:
4164 Builds up envcrc with the target environment so that external utils
4165 may easily extract it and embed it in final U-Boot images.
4167 - CONFIG_ENV_IS_IN_FLASH:
4169 Define this if the environment is in flash memory.
4171 a) The environment occupies one whole flash sector, which is
4172 "embedded" in the text segment with the U-Boot code. This
4173 happens usually with "bottom boot sector" or "top boot
4174 sector" type flash chips, which have several smaller
4175 sectors at the start or the end. For instance, such a
4176 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4177 such a case you would place the environment in one of the
4178 4 kB sectors - with U-Boot code before and after it. With
4179 "top boot sector" type flash chips, you would put the
4180 environment in one of the last sectors, leaving a gap
4181 between U-Boot and the environment.
4183 - CONFIG_ENV_OFFSET:
4185 Offset of environment data (variable area) to the
4186 beginning of flash memory; for instance, with bottom boot
4187 type flash chips the second sector can be used: the offset
4188 for this sector is given here.
4190 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4194 This is just another way to specify the start address of
4195 the flash sector containing the environment (instead of
4198 - CONFIG_ENV_SECT_SIZE:
4200 Size of the sector containing the environment.
4203 b) Sometimes flash chips have few, equal sized, BIG sectors.
4204 In such a case you don't want to spend a whole sector for
4209 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4210 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4211 of this flash sector for the environment. This saves
4212 memory for the RAM copy of the environment.
4214 It may also save flash memory if you decide to use this
4215 when your environment is "embedded" within U-Boot code,
4216 since then the remainder of the flash sector could be used
4217 for U-Boot code. It should be pointed out that this is
4218 STRONGLY DISCOURAGED from a robustness point of view:
4219 updating the environment in flash makes it always
4220 necessary to erase the WHOLE sector. If something goes
4221 wrong before the contents has been restored from a copy in
4222 RAM, your target system will be dead.
4224 - CONFIG_ENV_ADDR_REDUND
4225 CONFIG_ENV_SIZE_REDUND
4227 These settings describe a second storage area used to hold
4228 a redundant copy of the environment data, so that there is
4229 a valid backup copy in case there is a power failure during
4230 a "saveenv" operation.
4232 BE CAREFUL! Any changes to the flash layout, and some changes to the
4233 source code will make it necessary to adapt <board>/u-boot.lds*
4237 - CONFIG_ENV_IS_IN_NVRAM:
4239 Define this if you have some non-volatile memory device
4240 (NVRAM, battery buffered SRAM) which you want to use for the
4246 These two #defines are used to determine the memory area you
4247 want to use for environment. It is assumed that this memory
4248 can just be read and written to, without any special
4251 BE CAREFUL! The first access to the environment happens quite early
4252 in U-Boot initialization (when we try to get the setting of for the
4253 console baudrate). You *MUST* have mapped your NVRAM area then, or
4256 Please note that even with NVRAM we still use a copy of the
4257 environment in RAM: we could work on NVRAM directly, but we want to
4258 keep settings there always unmodified except somebody uses "saveenv"
4259 to save the current settings.
4262 - CONFIG_ENV_IS_IN_EEPROM:
4264 Use this if you have an EEPROM or similar serial access
4265 device and a driver for it.
4267 - CONFIG_ENV_OFFSET:
4270 These two #defines specify the offset and size of the
4271 environment area within the total memory of your EEPROM.
4273 - CONFIG_SYS_I2C_EEPROM_ADDR:
4274 If defined, specified the chip address of the EEPROM device.
4275 The default address is zero.
4277 - CONFIG_SYS_I2C_EEPROM_BUS:
4278 If defined, specified the i2c bus of the EEPROM device.
4280 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4281 If defined, the number of bits used to address bytes in a
4282 single page in the EEPROM device. A 64 byte page, for example
4283 would require six bits.
4285 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4286 If defined, the number of milliseconds to delay between
4287 page writes. The default is zero milliseconds.
4289 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4290 The length in bytes of the EEPROM memory array address. Note
4291 that this is NOT the chip address length!
4293 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4294 EEPROM chips that implement "address overflow" are ones
4295 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4296 address and the extra bits end up in the "chip address" bit
4297 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4300 Note that we consider the length of the address field to
4301 still be one byte because the extra address bits are hidden
4302 in the chip address.
4304 - CONFIG_SYS_EEPROM_SIZE:
4305 The size in bytes of the EEPROM device.
4307 - CONFIG_ENV_EEPROM_IS_ON_I2C
4308 define this, if you have I2C and SPI activated, and your
4309 EEPROM, which holds the environment, is on the I2C bus.
4311 - CONFIG_I2C_ENV_EEPROM_BUS
4312 if you have an Environment on an EEPROM reached over
4313 I2C muxes, you can define here, how to reach this
4314 EEPROM. For example:
4316 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4318 EEPROM which holds the environment, is reached over
4319 a pca9547 i2c mux with address 0x70, channel 3.
4321 - CONFIG_ENV_IS_IN_DATAFLASH:
4323 Define this if you have a DataFlash memory device which you
4324 want to use for the environment.
4326 - CONFIG_ENV_OFFSET:
4330 These three #defines specify the offset and size of the
4331 environment area within the total memory of your DataFlash placed
4332 at the specified address.
4334 - CONFIG_ENV_IS_IN_SPI_FLASH:
4336 Define this if you have a SPI Flash memory device which you
4337 want to use for the environment.
4339 - CONFIG_ENV_OFFSET:
4342 These two #defines specify the offset and size of the
4343 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4344 aligned to an erase sector boundary.
4346 - CONFIG_ENV_SECT_SIZE:
4348 Define the SPI flash's sector size.
4350 - CONFIG_ENV_OFFSET_REDUND (optional):
4352 This setting describes a second storage area of CONFIG_ENV_SIZE
4353 size used to hold a redundant copy of the environment data, so
4354 that there is a valid backup copy in case there is a power failure
4355 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4356 aligned to an erase sector boundary.
4358 - CONFIG_ENV_SPI_BUS (optional):
4359 - CONFIG_ENV_SPI_CS (optional):
4361 Define the SPI bus and chip select. If not defined they will be 0.
4363 - CONFIG_ENV_SPI_MAX_HZ (optional):
4365 Define the SPI max work clock. If not defined then use 1MHz.
4367 - CONFIG_ENV_SPI_MODE (optional):
4369 Define the SPI work mode. If not defined then use SPI_MODE_3.
4371 - CONFIG_ENV_IS_IN_REMOTE:
4373 Define this if you have a remote memory space which you
4374 want to use for the local device's environment.
4379 These two #defines specify the address and size of the
4380 environment area within the remote memory space. The
4381 local device can get the environment from remote memory
4382 space by SRIO or PCIE links.
4384 BE CAREFUL! For some special cases, the local device can not use
4385 "saveenv" command. For example, the local device will get the
4386 environment stored in a remote NOR flash by SRIO or PCIE link,
4387 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4389 - CONFIG_ENV_IS_IN_NAND:
4391 Define this if you have a NAND device which you want to use
4392 for the environment.
4394 - CONFIG_ENV_OFFSET:
4397 These two #defines specify the offset and size of the environment
4398 area within the first NAND device. CONFIG_ENV_OFFSET must be
4399 aligned to an erase block boundary.
4401 - CONFIG_ENV_OFFSET_REDUND (optional):
4403 This setting describes a second storage area of CONFIG_ENV_SIZE
4404 size used to hold a redundant copy of the environment data, so
4405 that there is a valid backup copy in case there is a power failure
4406 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4407 aligned to an erase block boundary.
4409 - CONFIG_ENV_RANGE (optional):
4411 Specifies the length of the region in which the environment
4412 can be written. This should be a multiple of the NAND device's
4413 block size. Specifying a range with more erase blocks than
4414 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4415 the range to be avoided.
4417 - CONFIG_ENV_OFFSET_OOB (optional):
4419 Enables support for dynamically retrieving the offset of the
4420 environment from block zero's out-of-band data. The
4421 "nand env.oob" command can be used to record this offset.
4422 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4423 using CONFIG_ENV_OFFSET_OOB.
4425 - CONFIG_NAND_ENV_DST
4427 Defines address in RAM to which the nand_spl code should copy the
4428 environment. If redundant environment is used, it will be copied to
4429 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4431 - CONFIG_ENV_IS_IN_UBI:
4433 Define this if you have an UBI volume that you want to use for the
4434 environment. This has the benefit of wear-leveling the environment
4435 accesses, which is important on NAND.
4437 - CONFIG_ENV_UBI_PART:
4439 Define this to a string that is the mtd partition containing the UBI.
4441 - CONFIG_ENV_UBI_VOLUME:
4443 Define this to the name of the volume that you want to store the
4446 - CONFIG_ENV_UBI_VOLUME_REDUND:
4448 Define this to the name of another volume to store a second copy of
4449 the environment in. This will enable redundant environments in UBI.
4450 It is assumed that both volumes are in the same MTD partition.
4452 - CONFIG_UBI_SILENCE_MSG
4453 - CONFIG_UBIFS_SILENCE_MSG
4455 You will probably want to define these to avoid a really noisy system
4456 when storing the env in UBI.
4458 - CONFIG_ENV_IS_IN_FAT:
4459 Define this if you want to use the FAT file system for the environment.
4461 - FAT_ENV_INTERFACE:
4463 Define this to a string that is the name of the block device.
4465 - FAT_ENV_DEV_AND_PART:
4467 Define this to a string to specify the partition of the device. It can
4470 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4471 - "D:P": device D partition P. Error occurs if device D has no
4474 - "D" or "D:": device D partition 1 if device D has partition
4475 table, or the whole device D if has no partition
4477 - "D:auto": first partition in device D with bootable flag set.
4478 If none, first valid partition in device D. If no
4479 partition table then means device D.
4483 It's a string of the FAT file name. This file use to store the
4487 This should be defined. Otherwise it cannot save the environment file.
4489 - CONFIG_ENV_IS_IN_MMC:
4491 Define this if you have an MMC device which you want to use for the
4494 - CONFIG_SYS_MMC_ENV_DEV:
4496 Specifies which MMC device the environment is stored in.
4498 - CONFIG_SYS_MMC_ENV_PART (optional):
4500 Specifies which MMC partition the environment is stored in. If not
4501 set, defaults to partition 0, the user area. Common values might be
4502 1 (first MMC boot partition), 2 (second MMC boot partition).
4504 - CONFIG_ENV_OFFSET:
4507 These two #defines specify the offset and size of the environment
4508 area within the specified MMC device.
4510 If offset is positive (the usual case), it is treated as relative to
4511 the start of the MMC partition. If offset is negative, it is treated
4512 as relative to the end of the MMC partition. This can be useful if
4513 your board may be fitted with different MMC devices, which have
4514 different sizes for the MMC partitions, and you always want the
4515 environment placed at the very end of the partition, to leave the
4516 maximum possible space before it, to store other data.
4518 These two values are in units of bytes, but must be aligned to an
4519 MMC sector boundary.
4521 - CONFIG_ENV_OFFSET_REDUND (optional):
4523 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4524 hold a redundant copy of the environment data. This provides a
4525 valid backup copy in case the other copy is corrupted, e.g. due
4526 to a power failure during a "saveenv" operation.
4528 This value may also be positive or negative; this is handled in the
4529 same way as CONFIG_ENV_OFFSET.
4531 This value is also in units of bytes, but must also be aligned to
4532 an MMC sector boundary.
4534 - CONFIG_ENV_SIZE_REDUND (optional):
4536 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4537 set. If this value is set, it must be set to the same value as
4540 - CONFIG_SYS_SPI_INIT_OFFSET
4542 Defines offset to the initial SPI buffer area in DPRAM. The
4543 area is used at an early stage (ROM part) if the environment
4544 is configured to reside in the SPI EEPROM: We need a 520 byte
4545 scratch DPRAM area. It is used between the two initialization
4546 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4547 to be a good choice since it makes it far enough from the
4548 start of the data area as well as from the stack pointer.
4550 Please note that the environment is read-only until the monitor
4551 has been relocated to RAM and a RAM copy of the environment has been
4552 created; also, when using EEPROM you will have to use getenv_f()
4553 until then to read environment variables.
4555 The environment is protected by a CRC32 checksum. Before the monitor
4556 is relocated into RAM, as a result of a bad CRC you will be working
4557 with the compiled-in default environment - *silently*!!! [This is
4558 necessary, because the first environment variable we need is the
4559 "baudrate" setting for the console - if we have a bad CRC, we don't
4560 have any device yet where we could complain.]
4562 Note: once the monitor has been relocated, then it will complain if
4563 the default environment is used; a new CRC is computed as soon as you
4564 use the "saveenv" command to store a valid environment.
4566 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4567 Echo the inverted Ethernet link state to the fault LED.
4569 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4570 also needs to be defined.
4572 - CONFIG_SYS_FAULT_MII_ADDR:
4573 MII address of the PHY to check for the Ethernet link state.
4575 - CONFIG_NS16550_MIN_FUNCTIONS:
4576 Define this if you desire to only have use of the NS16550_init
4577 and NS16550_putc functions for the serial driver located at
4578 drivers/serial/ns16550.c. This option is useful for saving
4579 space for already greatly restricted images, including but not
4580 limited to NAND_SPL configurations.
4582 - CONFIG_DISPLAY_BOARDINFO
4583 Display information about the board that U-Boot is running on
4584 when U-Boot starts up. The board function checkboard() is called
4587 - CONFIG_DISPLAY_BOARDINFO_LATE
4588 Similar to the previous option, but display this information
4589 later, once stdio is running and output goes to the LCD, if
4592 - CONFIG_BOARD_SIZE_LIMIT:
4593 Maximum size of the U-Boot image. When defined, the
4594 build system checks that the actual size does not
4597 Low Level (hardware related) configuration options:
4598 ---------------------------------------------------
4600 - CONFIG_SYS_CACHELINE_SIZE:
4601 Cache Line Size of the CPU.
4603 - CONFIG_SYS_DEFAULT_IMMR:
4604 Default address of the IMMR after system reset.
4606 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4607 and RPXsuper) to be able to adjust the position of
4608 the IMMR register after a reset.
4610 - CONFIG_SYS_CCSRBAR_DEFAULT:
4611 Default (power-on reset) physical address of CCSR on Freescale
4614 - CONFIG_SYS_CCSRBAR:
4615 Virtual address of CCSR. On a 32-bit build, this is typically
4616 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4618 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4619 for cross-platform code that uses that macro instead.
4621 - CONFIG_SYS_CCSRBAR_PHYS:
4622 Physical address of CCSR. CCSR can be relocated to a new
4623 physical address, if desired. In this case, this macro should
4624 be set to that address. Otherwise, it should be set to the
4625 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4626 is typically relocated on 36-bit builds. It is recommended
4627 that this macro be defined via the _HIGH and _LOW macros:
4629 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4630 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4632 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4633 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4634 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4635 used in assembly code, so it must not contain typecasts or
4636 integer size suffixes (e.g. "ULL").
4638 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4639 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4640 used in assembly code, so it must not contain typecasts or
4641 integer size suffixes (e.g. "ULL").
4643 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4644 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4645 forced to a value that ensures that CCSR is not relocated.
4647 - Floppy Disk Support:
4648 CONFIG_SYS_FDC_DRIVE_NUMBER
4650 the default drive number (default value 0)
4652 CONFIG_SYS_ISA_IO_STRIDE
4654 defines the spacing between FDC chipset registers
4657 CONFIG_SYS_ISA_IO_OFFSET
4659 defines the offset of register from address. It
4660 depends on which part of the data bus is connected to
4661 the FDC chipset. (default value 0)
4663 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4664 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4667 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4668 fdc_hw_init() is called at the beginning of the FDC
4669 setup. fdc_hw_init() must be provided by the board
4670 source code. It is used to make hardware-dependent
4674 Most IDE controllers were designed to be connected with PCI
4675 interface. Only few of them were designed for AHB interface.
4676 When software is doing ATA command and data transfer to
4677 IDE devices through IDE-AHB controller, some additional
4678 registers accessing to these kind of IDE-AHB controller
4681 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4682 DO NOT CHANGE unless you know exactly what you're
4683 doing! (11-4) [MPC8xx/82xx systems only]
4685 - CONFIG_SYS_INIT_RAM_ADDR:
4687 Start address of memory area that can be used for
4688 initial data and stack; please note that this must be
4689 writable memory that is working WITHOUT special
4690 initialization, i. e. you CANNOT use normal RAM which
4691 will become available only after programming the
4692 memory controller and running certain initialization
4695 U-Boot uses the following memory types:
4696 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4697 - MPC824X: data cache
4698 - PPC4xx: data cache
4700 - CONFIG_SYS_GBL_DATA_OFFSET:
4702 Offset of the initial data structure in the memory
4703 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4704 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4705 data is located at the end of the available space
4706 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4707 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4708 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4709 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4712 On the MPC824X (or other systems that use the data
4713 cache for initial memory) the address chosen for
4714 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4715 point to an otherwise UNUSED address space between
4716 the top of RAM and the start of the PCI space.
4718 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4720 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4722 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4724 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4726 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4728 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4730 - CONFIG_SYS_OR_TIMING_SDRAM:
4733 - CONFIG_SYS_MAMR_PTA:
4734 periodic timer for refresh
4736 - CONFIG_SYS_DER: Debug Event Register (37-47)
4738 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4739 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4740 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4741 CONFIG_SYS_BR1_PRELIM:
4742 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4744 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4745 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4746 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4747 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4749 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4750 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4751 Machine Mode Register and Memory Periodic Timer
4752 Prescaler definitions (SDRAM timing)
4754 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4755 enable I2C microcode relocation patch (MPC8xx);
4756 define relocation offset in DPRAM [DSP2]
4758 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4759 enable SMC microcode relocation patch (MPC8xx);
4760 define relocation offset in DPRAM [SMC1]
4762 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4763 enable SPI microcode relocation patch (MPC8xx);
4764 define relocation offset in DPRAM [SCC4]
4766 - CONFIG_SYS_USE_OSCCLK:
4767 Use OSCM clock mode on MBX8xx board. Be careful,
4768 wrong setting might damage your board. Read
4769 doc/README.MBX before setting this variable!
4771 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4772 Offset of the bootmode word in DPRAM used by post
4773 (Power On Self Tests). This definition overrides
4774 #define'd default value in commproc.h resp.
4777 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4778 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4779 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4780 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4781 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4782 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4783 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4784 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4785 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4787 - CONFIG_PCI_DISABLE_PCIE:
4788 Disable PCI-Express on systems where it is supported but not
4791 - CONFIG_PCI_ENUM_ONLY
4792 Only scan through and get the devices on the buses.
4793 Don't do any setup work, presumably because someone or
4794 something has already done it, and we don't need to do it
4795 a second time. Useful for platforms that are pre-booted
4796 by coreboot or similar.
4798 - CONFIG_PCI_INDIRECT_BRIDGE:
4799 Enable support for indirect PCI bridges.
4802 Chip has SRIO or not
4805 Board has SRIO 1 port available
4808 Board has SRIO 2 port available
4810 - CONFIG_SRIO_PCIE_BOOT_MASTER
4811 Board can support master function for Boot from SRIO and PCIE
4813 - CONFIG_SYS_SRIOn_MEM_VIRT:
4814 Virtual Address of SRIO port 'n' memory region
4816 - CONFIG_SYS_SRIOn_MEM_PHYS:
4817 Physical Address of SRIO port 'n' memory region
4819 - CONFIG_SYS_SRIOn_MEM_SIZE:
4820 Size of SRIO port 'n' memory region
4822 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4823 Defined to tell the NAND controller that the NAND chip is using
4825 Not all NAND drivers use this symbol.
4826 Example of drivers that use it:
4827 - drivers/mtd/nand/ndfc.c
4828 - drivers/mtd/nand/mxc_nand.c
4830 - CONFIG_SYS_NDFC_EBC0_CFG
4831 Sets the EBC0_CFG register for the NDFC. If not defined
4832 a default value will be used.
4835 Get DDR timing information from an I2C EEPROM. Common
4836 with pluggable memory modules such as SODIMMs
4839 I2C address of the SPD EEPROM
4841 - CONFIG_SYS_SPD_BUS_NUM
4842 If SPD EEPROM is on an I2C bus other than the first
4843 one, specify here. Note that the value must resolve
4844 to something your driver can deal with.
4846 - CONFIG_SYS_DDR_RAW_TIMING
4847 Get DDR timing information from other than SPD. Common with
4848 soldered DDR chips onboard without SPD. DDR raw timing
4849 parameters are extracted from datasheet and hard-coded into
4850 header files or board specific files.
4852 - CONFIG_FSL_DDR_INTERACTIVE
4853 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4855 - CONFIG_FSL_DDR_SYNC_REFRESH
4856 Enable sync of refresh for multiple controllers.
4858 - CONFIG_FSL_DDR_BIST
4859 Enable built-in memory test for Freescale DDR controllers.
4861 - CONFIG_SYS_83XX_DDR_USES_CS0
4862 Only for 83xx systems. If specified, then DDR should
4863 be configured using CS0 and CS1 instead of CS2 and CS3.
4865 - CONFIG_ETHER_ON_FEC[12]
4866 Define to enable FEC[12] on a 8xx series processor.
4868 - CONFIG_FEC[12]_PHY
4869 Define to the hardcoded PHY address which corresponds
4870 to the given FEC; i. e.
4871 #define CONFIG_FEC1_PHY 4
4872 means that the PHY with address 4 is connected to FEC1
4874 When set to -1, means to probe for first available.
4876 - CONFIG_FEC[12]_PHY_NORXERR
4877 The PHY does not have a RXERR line (RMII only).
4878 (so program the FEC to ignore it).
4881 Enable RMII mode for all FECs.
4882 Note that this is a global option, we can't
4883 have one FEC in standard MII mode and another in RMII mode.
4885 - CONFIG_CRC32_VERIFY
4886 Add a verify option to the crc32 command.
4889 => crc32 -v <address> <count> <crc32>
4891 Where address/count indicate a memory area
4892 and crc32 is the correct crc32 which the
4896 Add the "loopw" memory command. This only takes effect if
4897 the memory commands are activated globally (CONFIG_CMD_MEM).
4900 Add the "mdc" and "mwc" memory commands. These are cyclic
4905 This command will print 4 bytes (10,11,12,13) each 500 ms.
4907 => mwc.l 100 12345678 10
4908 This command will write 12345678 to address 100 all 10 ms.
4910 This only takes effect if the memory commands are activated
4911 globally (CONFIG_CMD_MEM).
4913 - CONFIG_SKIP_LOWLEVEL_INIT
4914 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4915 low level initializations (like setting up the memory
4916 controller) are omitted and/or U-Boot does not
4917 relocate itself into RAM.
4919 Normally this variable MUST NOT be defined. The only
4920 exception is when U-Boot is loaded (to RAM) by some
4921 other boot loader or by a debugger which performs
4922 these initializations itself.
4925 Modifies the behaviour of start.S when compiling a loader
4926 that is executed before the actual U-Boot. E.g. when
4927 compiling a NAND SPL.
4930 Modifies the behaviour of start.S when compiling a loader
4931 that is executed after the SPL and before the actual U-Boot.
4932 It is loaded by the SPL.
4934 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4935 Only for 85xx systems. If this variable is specified, the section
4936 .resetvec is not kept and the section .bootpg is placed in the
4937 previous 4k of the .text section.
4939 - CONFIG_ARCH_MAP_SYSMEM
4940 Generally U-Boot (and in particular the md command) uses
4941 effective address. It is therefore not necessary to regard
4942 U-Boot address as virtual addresses that need to be translated
4943 to physical addresses. However, sandbox requires this, since
4944 it maintains its own little RAM buffer which contains all
4945 addressable memory. This option causes some memory accesses
4946 to be mapped through map_sysmem() / unmap_sysmem().
4948 - CONFIG_USE_ARCH_MEMCPY
4949 CONFIG_USE_ARCH_MEMSET
4950 If these options are used a optimized version of memcpy/memset will
4951 be used if available. These functions may be faster under some
4952 conditions but may increase the binary size.
4954 - CONFIG_X86_RESET_VECTOR
4955 If defined, the x86 reset vector code is included. This is not
4956 needed when U-Boot is running from Coreboot.
4959 Defines the MPU clock speed (in MHz).
4961 NOTE : currently only supported on AM335x platforms.
4963 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4964 Enables the RTC32K OSC on AM33xx based plattforms
4966 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4967 Option to disable subpage write in NAND driver
4968 driver that uses this:
4969 drivers/mtd/nand/davinci_nand.c
4971 Freescale QE/FMAN Firmware Support:
4972 -----------------------------------
4974 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4975 loading of "firmware", which is encoded in the QE firmware binary format.
4976 This firmware often needs to be loaded during U-Boot booting, so macros
4977 are used to identify the storage device (NOR flash, SPI, etc) and the address
4980 - CONFIG_SYS_FMAN_FW_ADDR
4981 The address in the storage device where the FMAN microcode is located. The
4982 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4985 - CONFIG_SYS_QE_FW_ADDR
4986 The address in the storage device where the QE microcode is located. The
4987 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4990 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4991 The maximum possible size of the firmware. The firmware binary format
4992 has a field that specifies the actual size of the firmware, but it
4993 might not be possible to read any part of the firmware unless some
4994 local storage is allocated to hold the entire firmware first.
4996 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4997 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4998 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4999 virtual address in NOR flash.
5001 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5002 Specifies that QE/FMAN firmware is located in NAND flash.
5003 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5005 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5006 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5007 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5009 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5010 Specifies that QE/FMAN firmware is located on the primary SPI
5011 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5013 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5014 Specifies that QE/FMAN firmware is located in the remote (master)
5015 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5016 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5017 window->master inbound window->master LAW->the ucode address in
5018 master's memory space.
5020 Freescale Layerscape Management Complex Firmware Support:
5021 ---------------------------------------------------------
5022 The Freescale Layerscape Management Complex (MC) supports the loading of
5024 This firmware often needs to be loaded during U-Boot booting, so macros
5025 are used to identify the storage device (NOR flash, SPI, etc) and the address
5028 - CONFIG_FSL_MC_ENET
5029 Enable the MC driver for Layerscape SoCs.
5031 - CONFIG_SYS_LS_MC_FW_ADDR
5032 The address in the storage device where the firmware is located. The
5033 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5036 - CONFIG_SYS_LS_MC_FW_LENGTH
5037 The maximum possible size of the firmware. The firmware binary format
5038 has a field that specifies the actual size of the firmware, but it
5039 might not be possible to read any part of the firmware unless some
5040 local storage is allocated to hold the entire firmware first.
5042 - CONFIG_SYS_LS_MC_FW_IN_NOR
5043 Specifies that MC firmware is located in NOR flash, mapped as
5044 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5045 virtual address in NOR flash.
5047 Freescale Layerscape Debug Server Support:
5048 -------------------------------------------
5049 The Freescale Layerscape Debug Server Support supports the loading of
5050 "Debug Server firmware" and triggering SP boot-rom.
5051 This firmware often needs to be loaded during U-Boot booting.
5053 - CONFIG_FSL_DEBUG_SERVER
5054 Enable the Debug Server for Layerscape SoCs.
5056 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5057 Define minimum DDR size required for debug server image
5059 - CONFIG_SYS_MC_RSV_MEM_ALIGN
5060 Define alignment of reserved memory MC requires
5065 In order to achieve reproducible builds, timestamps used in the U-Boot build
5066 process have to be set to a fixed value.
5068 This is done using the SOURCE_DATE_EPOCH environment variable.
5069 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5070 option for U-Boot or an environment variable in U-Boot.
5072 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5074 Building the Software:
5075 ======================
5077 Building U-Boot has been tested in several native build environments
5078 and in many different cross environments. Of course we cannot support
5079 all possibly existing versions of cross development tools in all
5080 (potentially obsolete) versions. In case of tool chain problems we
5081 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5082 which is extensively used to build and test U-Boot.
5084 If you are not using a native environment, it is assumed that you
5085 have GNU cross compiling tools available in your path. In this case,
5086 you must set the environment variable CROSS_COMPILE in your shell.
5087 Note that no changes to the Makefile or any other source files are
5088 necessary. For example using the ELDK on a 4xx CPU, please enter:
5090 $ CROSS_COMPILE=ppc_4xx-
5091 $ export CROSS_COMPILE
5093 Note: If you wish to generate Windows versions of the utilities in
5094 the tools directory you can use the MinGW toolchain
5095 (http://www.mingw.org). Set your HOST tools to the MinGW
5096 toolchain and execute 'make tools'. For example:
5098 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5100 Binaries such as tools/mkimage.exe will be created which can
5101 be executed on computers running Windows.
5103 U-Boot is intended to be simple to build. After installing the
5104 sources you must configure U-Boot for one specific board type. This
5109 where "NAME_defconfig" is the name of one of the existing configu-
5110 rations; see boards.cfg for supported names.
5112 Note: for some board special configuration names may exist; check if
5113 additional information is available from the board vendor; for
5114 instance, the TQM823L systems are available without (standard)
5115 or with LCD support. You can select such additional "features"
5116 when choosing the configuration, i. e.
5118 make TQM823L_defconfig
5119 - will configure for a plain TQM823L, i. e. no LCD support
5121 make TQM823L_LCD_defconfig
5122 - will configure for a TQM823L with U-Boot console on LCD
5127 Finally, type "make all", and you should get some working U-Boot
5128 images ready for download to / installation on your system:
5130 - "u-boot.bin" is a raw binary image
5131 - "u-boot" is an image in ELF binary format
5132 - "u-boot.srec" is in Motorola S-Record format
5134 By default the build is performed locally and the objects are saved
5135 in the source directory. One of the two methods can be used to change
5136 this behavior and build U-Boot to some external directory:
5138 1. Add O= to the make command line invocations:
5140 make O=/tmp/build distclean
5141 make O=/tmp/build NAME_defconfig
5142 make O=/tmp/build all
5144 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5146 export KBUILD_OUTPUT=/tmp/build
5151 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5155 Please be aware that the Makefiles assume you are using GNU make, so
5156 for instance on NetBSD you might need to use "gmake" instead of
5160 If the system board that you have is not listed, then you will need
5161 to port U-Boot to your hardware platform. To do this, follow these
5164 1. Add a new configuration option for your board to the toplevel
5165 "boards.cfg" file, using the existing entries as examples.
5166 Follow the instructions there to keep the boards in order.
5167 2. Create a new directory to hold your board specific code. Add any
5168 files you need. In your board directory, you will need at least
5169 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5170 3. Create a new configuration file "include/configs/<board>.h" for
5172 3. If you're porting U-Boot to a new CPU, then also create a new
5173 directory to hold your CPU specific code. Add any files you need.
5174 4. Run "make <board>_defconfig" with your new name.
5175 5. Type "make", and you should get a working "u-boot.srec" file
5176 to be installed on your target system.
5177 6. Debug and solve any problems that might arise.
5178 [Of course, this last step is much harder than it sounds.]
5181 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5182 ==============================================================
5184 If you have modified U-Boot sources (for instance added a new board
5185 or support for new devices, a new CPU, etc.) you are expected to
5186 provide feedback to the other developers. The feedback normally takes
5187 the form of a "patch", i. e. a context diff against a certain (latest
5188 official or latest in the git repository) version of U-Boot sources.
5190 But before you submit such a patch, please verify that your modifi-
5191 cation did not break existing code. At least make sure that *ALL* of
5192 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5193 just run the "MAKEALL" script, which will configure and build U-Boot
5194 for ALL supported system. Be warned, this will take a while. You can
5195 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5196 environment variable to the script, i. e. to use the ELDK cross tools
5199 CROSS_COMPILE=ppc_8xx- MAKEALL
5201 or to build on a native PowerPC system you can type
5203 CROSS_COMPILE=' ' MAKEALL
5205 When using the MAKEALL script, the default behaviour is to build
5206 U-Boot in the source directory. This location can be changed by
5207 setting the BUILD_DIR environment variable. Also, for each target
5208 built, the MAKEALL script saves two log files (<target>.ERR and
5209 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5210 location can be changed by setting the MAKEALL_LOGDIR environment
5211 variable. For example:
5213 export BUILD_DIR=/tmp/build
5214 export MAKEALL_LOGDIR=/tmp/log
5215 CROSS_COMPILE=ppc_8xx- MAKEALL
5217 With the above settings build objects are saved in the /tmp/build,
5218 log files are saved in the /tmp/log and the source tree remains clean
5219 during the whole build process.
5222 See also "U-Boot Porting Guide" below.
5225 Monitor Commands - Overview:
5226 ============================
5228 go - start application at address 'addr'
5229 run - run commands in an environment variable
5230 bootm - boot application image from memory
5231 bootp - boot image via network using BootP/TFTP protocol
5232 bootz - boot zImage from memory
5233 tftpboot- boot image via network using TFTP protocol
5234 and env variables "ipaddr" and "serverip"
5235 (and eventually "gatewayip")
5236 tftpput - upload a file via network using TFTP protocol
5237 rarpboot- boot image via network using RARP/TFTP protocol
5238 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5239 loads - load S-Record file over serial line
5240 loadb - load binary file over serial line (kermit mode)
5242 mm - memory modify (auto-incrementing)
5243 nm - memory modify (constant address)
5244 mw - memory write (fill)
5246 cmp - memory compare
5247 crc32 - checksum calculation
5248 i2c - I2C sub-system
5249 sspi - SPI utility commands
5250 base - print or set address offset
5251 printenv- print environment variables
5252 setenv - set environment variables
5253 saveenv - save environment variables to persistent storage
5254 protect - enable or disable FLASH write protection
5255 erase - erase FLASH memory
5256 flinfo - print FLASH memory information
5257 nand - NAND memory operations (see doc/README.nand)
5258 bdinfo - print Board Info structure
5259 iminfo - print header information for application image
5260 coninfo - print console devices and informations
5261 ide - IDE sub-system
5262 loop - infinite loop on address range
5263 loopw - infinite write loop on address range
5264 mtest - simple RAM test
5265 icache - enable or disable instruction cache
5266 dcache - enable or disable data cache
5267 reset - Perform RESET of the CPU
5268 echo - echo args to console
5269 version - print monitor version
5270 help - print online help
5271 ? - alias for 'help'
5274 Monitor Commands - Detailed Description:
5275 ========================================
5279 For now: just type "help <command>".
5282 Environment Variables:
5283 ======================
5285 U-Boot supports user configuration using Environment Variables which
5286 can be made persistent by saving to Flash memory.
5288 Environment Variables are set using "setenv", printed using
5289 "printenv", and saved to Flash using "saveenv". Using "setenv"
5290 without a value can be used to delete a variable from the
5291 environment. As long as you don't save the environment you are
5292 working with an in-memory copy. In case the Flash area containing the
5293 environment is erased by accident, a default environment is provided.
5295 Some configuration options can be set using Environment Variables.
5297 List of environment variables (most likely not complete):
5299 baudrate - see CONFIG_BAUDRATE
5301 bootdelay - see CONFIG_BOOTDELAY
5303 bootcmd - see CONFIG_BOOTCOMMAND
5305 bootargs - Boot arguments when booting an RTOS image
5307 bootfile - Name of the image to load with TFTP
5309 bootm_low - Memory range available for image processing in the bootm
5310 command can be restricted. This variable is given as
5311 a hexadecimal number and defines lowest address allowed
5312 for use by the bootm command. See also "bootm_size"
5313 environment variable. Address defined by "bootm_low" is
5314 also the base of the initial memory mapping for the Linux
5315 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5318 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5319 This variable is given as a hexadecimal number and it
5320 defines the size of the memory region starting at base
5321 address bootm_low that is accessible by the Linux kernel
5322 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5323 as the default value if it is defined, and bootm_size is
5326 bootm_size - Memory range available for image processing in the bootm
5327 command can be restricted. This variable is given as
5328 a hexadecimal number and defines the size of the region
5329 allowed for use by the bootm command. See also "bootm_low"
5330 environment variable.
5332 updatefile - Location of the software update file on a TFTP server, used
5333 by the automatic software update feature. Please refer to
5334 documentation in doc/README.update for more details.
5336 autoload - if set to "no" (any string beginning with 'n'),
5337 "bootp" will just load perform a lookup of the
5338 configuration from the BOOTP server, but not try to
5339 load any image using TFTP
5341 autostart - if set to "yes", an image loaded using the "bootp",
5342 "rarpboot", "tftpboot" or "diskboot" commands will
5343 be automatically started (by internally calling
5346 If set to "no", a standalone image passed to the
5347 "bootm" command will be copied to the load address
5348 (and eventually uncompressed), but NOT be started.
5349 This can be used to load and uncompress arbitrary
5352 fdt_high - if set this restricts the maximum address that the
5353 flattened device tree will be copied into upon boot.
5354 For example, if you have a system with 1 GB memory
5355 at physical address 0x10000000, while Linux kernel
5356 only recognizes the first 704 MB as low memory, you
5357 may need to set fdt_high as 0x3C000000 to have the
5358 device tree blob be copied to the maximum address
5359 of the 704 MB low memory, so that Linux kernel can
5360 access it during the boot procedure.
5362 If this is set to the special value 0xFFFFFFFF then
5363 the fdt will not be copied at all on boot. For this
5364 to work it must reside in writable memory, have
5365 sufficient padding on the end of it for u-boot to
5366 add the information it needs into it, and the memory
5367 must be accessible by the kernel.
5369 fdtcontroladdr- if set this is the address of the control flattened
5370 device tree used by U-Boot when CONFIG_OF_CONTROL is
5373 i2cfast - (PPC405GP|PPC405EP only)
5374 if set to 'y' configures Linux I2C driver for fast
5375 mode (400kHZ). This environment variable is used in
5376 initialization code. So, for changes to be effective
5377 it must be saved and board must be reset.
5379 initrd_high - restrict positioning of initrd images:
5380 If this variable is not set, initrd images will be
5381 copied to the highest possible address in RAM; this
5382 is usually what you want since it allows for
5383 maximum initrd size. If for some reason you want to
5384 make sure that the initrd image is loaded below the
5385 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5386 variable to a value of "no" or "off" or "0".
5387 Alternatively, you can set it to a maximum upper
5388 address to use (U-Boot will still check that it
5389 does not overwrite the U-Boot stack and data).
5391 For instance, when you have a system with 16 MB
5392 RAM, and want to reserve 4 MB from use by Linux,
5393 you can do this by adding "mem=12M" to the value of
5394 the "bootargs" variable. However, now you must make
5395 sure that the initrd image is placed in the first
5396 12 MB as well - this can be done with
5398 setenv initrd_high 00c00000
5400 If you set initrd_high to 0xFFFFFFFF, this is an
5401 indication to U-Boot that all addresses are legal
5402 for the Linux kernel, including addresses in flash
5403 memory. In this case U-Boot will NOT COPY the
5404 ramdisk at all. This may be useful to reduce the
5405 boot time on your system, but requires that this
5406 feature is supported by your Linux kernel.
5408 ipaddr - IP address; needed for tftpboot command
5410 loadaddr - Default load address for commands like "bootp",
5411 "rarpboot", "tftpboot", "loadb" or "diskboot"
5413 loads_echo - see CONFIG_LOADS_ECHO
5415 serverip - TFTP server IP address; needed for tftpboot command
5417 bootretry - see CONFIG_BOOT_RETRY_TIME
5419 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5421 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5423 ethprime - controls which interface is used first.
5425 ethact - controls which interface is currently active.
5426 For example you can do the following
5428 => setenv ethact FEC
5429 => ping 192.168.0.1 # traffic sent on FEC
5430 => setenv ethact SCC
5431 => ping 10.0.0.1 # traffic sent on SCC
5433 ethrotate - When set to "no" U-Boot does not go through all
5434 available network interfaces.
5435 It just stays at the currently selected interface.
5437 netretry - When set to "no" each network operation will
5438 either succeed or fail without retrying.
5439 When set to "once" the network operation will
5440 fail when all the available network interfaces
5441 are tried once without success.
5442 Useful on scripts which control the retry operation
5445 npe_ucode - set load address for the NPE microcode
5447 silent_linux - If set then Linux will be told to boot silently, by
5448 changing the console to be empty. If "yes" it will be
5449 made silent. If "no" it will not be made silent. If
5450 unset, then it will be made silent if the U-Boot console
5453 tftpsrcp - If this is set, the value is used for TFTP's
5456 tftpdstp - If this is set, the value is used for TFTP's UDP
5457 destination port instead of the Well Know Port 69.
5459 tftpblocksize - Block size to use for TFTP transfers; if not set,
5460 we use the TFTP server's default block size
5462 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5463 seconds, minimum value is 1000 = 1 second). Defines
5464 when a packet is considered to be lost so it has to
5465 be retransmitted. The default is 5000 = 5 seconds.
5466 Lowering this value may make downloads succeed
5467 faster in networks with high packet loss rates or
5468 with unreliable TFTP servers.
5470 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5471 unit, minimum value = 0). Defines how many timeouts
5472 can happen during a single file transfer before that
5473 transfer is aborted. The default is 10, and 0 means
5474 'no timeouts allowed'. Increasing this value may help
5475 downloads succeed with high packet loss rates, or with
5476 unreliable TFTP servers or client hardware.
5478 vlan - When set to a value < 4095 the traffic over
5479 Ethernet is encapsulated/received over 802.1q
5482 The following image location variables contain the location of images
5483 used in booting. The "Image" column gives the role of the image and is
5484 not an environment variable name. The other columns are environment
5485 variable names. "File Name" gives the name of the file on a TFTP
5486 server, "RAM Address" gives the location in RAM the image will be
5487 loaded to, and "Flash Location" gives the image's address in NOR
5488 flash or offset in NAND flash.
5490 *Note* - these variables don't have to be defined for all boards, some
5491 boards currently use other variables for these purposes, and some
5492 boards use these variables for other purposes.
5494 Image File Name RAM Address Flash Location
5495 ----- --------- ----------- --------------
5496 u-boot u-boot u-boot_addr_r u-boot_addr
5497 Linux kernel bootfile kernel_addr_r kernel_addr
5498 device tree blob fdtfile fdt_addr_r fdt_addr
5499 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5501 The following environment variables may be used and automatically
5502 updated by the network boot commands ("bootp" and "rarpboot"),
5503 depending the information provided by your boot server:
5505 bootfile - see above
5506 dnsip - IP address of your Domain Name Server
5507 dnsip2 - IP address of your secondary Domain Name Server
5508 gatewayip - IP address of the Gateway (Router) to use
5509 hostname - Target hostname
5511 netmask - Subnet Mask
5512 rootpath - Pathname of the root filesystem on the NFS server
5513 serverip - see above
5516 There are two special Environment Variables:
5518 serial# - contains hardware identification information such
5519 as type string and/or serial number
5520 ethaddr - Ethernet address
5522 These variables can be set only once (usually during manufacturing of
5523 the board). U-Boot refuses to delete or overwrite these variables
5524 once they have been set once.
5527 Further special Environment Variables:
5529 ver - Contains the U-Boot version string as printed
5530 with the "version" command. This variable is
5531 readonly (see CONFIG_VERSION_VARIABLE).
5534 Please note that changes to some configuration parameters may take
5535 only effect after the next boot (yes, that's just like Windoze :-).
5538 Callback functions for environment variables:
5539 ---------------------------------------------
5541 For some environment variables, the behavior of u-boot needs to change
5542 when their values are changed. This functionality allows functions to
5543 be associated with arbitrary variables. On creation, overwrite, or
5544 deletion, the callback will provide the opportunity for some side
5545 effect to happen or for the change to be rejected.
5547 The callbacks are named and associated with a function using the
5548 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5550 These callbacks are associated with variables in one of two ways. The
5551 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5552 in the board configuration to a string that defines a list of
5553 associations. The list must be in the following format:
5555 entry = variable_name[:callback_name]
5558 If the callback name is not specified, then the callback is deleted.
5559 Spaces are also allowed anywhere in the list.
5561 Callbacks can also be associated by defining the ".callbacks" variable
5562 with the same list format above. Any association in ".callbacks" will
5563 override any association in the static list. You can define
5564 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5565 ".callbacks" environment variable in the default or embedded environment.
5567 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5568 regular expression. This allows multiple variables to be connected to
5569 the same callback without explicitly listing them all out.
5572 Command Line Parsing:
5573 =====================
5575 There are two different command line parsers available with U-Boot:
5576 the old "simple" one, and the much more powerful "hush" shell:
5578 Old, simple command line parser:
5579 --------------------------------
5581 - supports environment variables (through setenv / saveenv commands)
5582 - several commands on one line, separated by ';'
5583 - variable substitution using "... ${name} ..." syntax
5584 - special characters ('$', ';') can be escaped by prefixing with '\',
5586 setenv bootcmd bootm \${address}
5587 - You can also escape text by enclosing in single apostrophes, for example:
5588 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5593 - similar to Bourne shell, with control structures like
5594 if...then...else...fi, for...do...done; while...do...done,
5595 until...do...done, ...
5596 - supports environment ("global") variables (through setenv / saveenv
5597 commands) and local shell variables (through standard shell syntax
5598 "name=value"); only environment variables can be used with "run"
5604 (1) If a command line (or an environment variable executed by a "run"
5605 command) contains several commands separated by semicolon, and
5606 one of these commands fails, then the remaining commands will be
5609 (2) If you execute several variables with one call to run (i. e.
5610 calling run with a list of variables as arguments), any failing
5611 command will cause "run" to terminate, i. e. the remaining
5612 variables are not executed.
5614 Note for Redundant Ethernet Interfaces:
5615 =======================================
5617 Some boards come with redundant Ethernet interfaces; U-Boot supports
5618 such configurations and is capable of automatic selection of a
5619 "working" interface when needed. MAC assignment works as follows:
5621 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5622 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5623 "eth1addr" (=>eth1), "eth2addr", ...
5625 If the network interface stores some valid MAC address (for instance
5626 in SROM), this is used as default address if there is NO correspon-
5627 ding setting in the environment; if the corresponding environment
5628 variable is set, this overrides the settings in the card; that means:
5630 o If the SROM has a valid MAC address, and there is no address in the
5631 environment, the SROM's address is used.
5633 o If there is no valid address in the SROM, and a definition in the
5634 environment exists, then the value from the environment variable is
5637 o If both the SROM and the environment contain a MAC address, and
5638 both addresses are the same, this MAC address is used.
5640 o If both the SROM and the environment contain a MAC address, and the
5641 addresses differ, the value from the environment is used and a
5644 o If neither SROM nor the environment contain a MAC address, an error
5645 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5646 a random, locally-assigned MAC is used.
5648 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5649 will be programmed into hardware as part of the initialization process. This
5650 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5651 The naming convention is as follows:
5652 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5657 U-Boot is capable of booting (and performing other auxiliary operations on)
5658 images in two formats:
5660 New uImage format (FIT)
5661 -----------------------
5663 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5664 to Flattened Device Tree). It allows the use of images with multiple
5665 components (several kernels, ramdisks, etc.), with contents protected by
5666 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5672 Old image format is based on binary files which can be basically anything,
5673 preceded by a special header; see the definitions in include/image.h for
5674 details; basically, the header defines the following image properties:
5676 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5677 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5678 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5679 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5681 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5682 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5683 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5684 * Compression Type (uncompressed, gzip, bzip2)
5690 The header is marked by a special Magic Number, and both the header
5691 and the data portions of the image are secured against corruption by
5698 Although U-Boot should support any OS or standalone application
5699 easily, the main focus has always been on Linux during the design of
5702 U-Boot includes many features that so far have been part of some
5703 special "boot loader" code within the Linux kernel. Also, any
5704 "initrd" images to be used are no longer part of one big Linux image;
5705 instead, kernel and "initrd" are separate images. This implementation
5706 serves several purposes:
5708 - the same features can be used for other OS or standalone
5709 applications (for instance: using compressed images to reduce the
5710 Flash memory footprint)
5712 - it becomes much easier to port new Linux kernel versions because
5713 lots of low-level, hardware dependent stuff are done by U-Boot
5715 - the same Linux kernel image can now be used with different "initrd"
5716 images; of course this also means that different kernel images can
5717 be run with the same "initrd". This makes testing easier (you don't
5718 have to build a new "zImage.initrd" Linux image when you just
5719 change a file in your "initrd"). Also, a field-upgrade of the
5720 software is easier now.
5726 Porting Linux to U-Boot based systems:
5727 ---------------------------------------
5729 U-Boot cannot save you from doing all the necessary modifications to
5730 configure the Linux device drivers for use with your target hardware
5731 (no, we don't intend to provide a full virtual machine interface to
5734 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5736 Just make sure your machine specific header file (for instance
5737 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5738 Information structure as we define in include/asm-<arch>/u-boot.h,
5739 and make sure that your definition of IMAP_ADDR uses the same value
5740 as your U-Boot configuration in CONFIG_SYS_IMMR.
5742 Note that U-Boot now has a driver model, a unified model for drivers.
5743 If you are adding a new driver, plumb it into driver model. If there
5744 is no uclass available, you are encouraged to create one. See
5748 Configuring the Linux kernel:
5749 -----------------------------
5751 No specific requirements for U-Boot. Make sure you have some root
5752 device (initial ramdisk, NFS) for your target system.
5755 Building a Linux Image:
5756 -----------------------
5758 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5759 not used. If you use recent kernel source, a new build target
5760 "uImage" will exist which automatically builds an image usable by
5761 U-Boot. Most older kernels also have support for a "pImage" target,
5762 which was introduced for our predecessor project PPCBoot and uses a
5763 100% compatible format.
5767 make TQM850L_defconfig
5772 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5773 encapsulate a compressed Linux kernel image with header information,
5774 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5776 * build a standard "vmlinux" kernel image (in ELF binary format):
5778 * convert the kernel into a raw binary image:
5780 ${CROSS_COMPILE}-objcopy -O binary \
5781 -R .note -R .comment \
5782 -S vmlinux linux.bin
5784 * compress the binary image:
5788 * package compressed binary image for U-Boot:
5790 mkimage -A ppc -O linux -T kernel -C gzip \
5791 -a 0 -e 0 -n "Linux Kernel Image" \
5792 -d linux.bin.gz uImage
5795 The "mkimage" tool can also be used to create ramdisk images for use
5796 with U-Boot, either separated from the Linux kernel image, or
5797 combined into one file. "mkimage" encapsulates the images with a 64
5798 byte header containing information about target architecture,
5799 operating system, image type, compression method, entry points, time
5800 stamp, CRC32 checksums, etc.
5802 "mkimage" can be called in two ways: to verify existing images and
5803 print the header information, or to build new images.
5805 In the first form (with "-l" option) mkimage lists the information
5806 contained in the header of an existing U-Boot image; this includes
5807 checksum verification:
5809 tools/mkimage -l image
5810 -l ==> list image header information
5812 The second form (with "-d" option) is used to build a U-Boot image
5813 from a "data file" which is used as image payload:
5815 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5816 -n name -d data_file image
5817 -A ==> set architecture to 'arch'
5818 -O ==> set operating system to 'os'
5819 -T ==> set image type to 'type'
5820 -C ==> set compression type 'comp'
5821 -a ==> set load address to 'addr' (hex)
5822 -e ==> set entry point to 'ep' (hex)
5823 -n ==> set image name to 'name'
5824 -d ==> use image data from 'datafile'
5826 Right now, all Linux kernels for PowerPC systems use the same load
5827 address (0x00000000), but the entry point address depends on the
5830 - 2.2.x kernels have the entry point at 0x0000000C,
5831 - 2.3.x and later kernels have the entry point at 0x00000000.
5833 So a typical call to build a U-Boot image would read:
5835 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5836 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5837 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5838 > examples/uImage.TQM850L
5839 Image Name: 2.4.4 kernel for TQM850L
5840 Created: Wed Jul 19 02:34:59 2000
5841 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5842 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5843 Load Address: 0x00000000
5844 Entry Point: 0x00000000
5846 To verify the contents of the image (or check for corruption):
5848 -> tools/mkimage -l examples/uImage.TQM850L
5849 Image Name: 2.4.4 kernel for TQM850L
5850 Created: Wed Jul 19 02:34:59 2000
5851 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5852 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5853 Load Address: 0x00000000
5854 Entry Point: 0x00000000
5856 NOTE: for embedded systems where boot time is critical you can trade
5857 speed for memory and install an UNCOMPRESSED image instead: this
5858 needs more space in Flash, but boots much faster since it does not
5859 need to be uncompressed:
5861 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5862 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5863 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5864 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5865 > examples/uImage.TQM850L-uncompressed
5866 Image Name: 2.4.4 kernel for TQM850L
5867 Created: Wed Jul 19 02:34:59 2000
5868 Image Type: PowerPC Linux Kernel Image (uncompressed)
5869 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5870 Load Address: 0x00000000
5871 Entry Point: 0x00000000
5874 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5875 when your kernel is intended to use an initial ramdisk:
5877 -> tools/mkimage -n 'Simple Ramdisk Image' \
5878 > -A ppc -O linux -T ramdisk -C gzip \
5879 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5880 Image Name: Simple Ramdisk Image
5881 Created: Wed Jan 12 14:01:50 2000
5882 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5883 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5884 Load Address: 0x00000000
5885 Entry Point: 0x00000000
5887 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5888 option performs the converse operation of the mkimage's second form (the "-d"
5889 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5892 tools/dumpimage -i image -T type -p position data_file
5893 -i ==> extract from the 'image' a specific 'data_file'
5894 -T ==> set image type to 'type'
5895 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5898 Installing a Linux Image:
5899 -------------------------
5901 To downloading a U-Boot image over the serial (console) interface,
5902 you must convert the image to S-Record format:
5904 objcopy -I binary -O srec examples/image examples/image.srec
5906 The 'objcopy' does not understand the information in the U-Boot
5907 image header, so the resulting S-Record file will be relative to
5908 address 0x00000000. To load it to a given address, you need to
5909 specify the target address as 'offset' parameter with the 'loads'
5912 Example: install the image to address 0x40100000 (which on the
5913 TQM8xxL is in the first Flash bank):
5915 => erase 40100000 401FFFFF
5921 ## Ready for S-Record download ...
5922 ~>examples/image.srec
5923 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5925 15989 15990 15991 15992
5926 [file transfer complete]
5928 ## Start Addr = 0x00000000
5931 You can check the success of the download using the 'iminfo' command;
5932 this includes a checksum verification so you can be sure no data
5933 corruption happened:
5937 ## Checking Image at 40100000 ...
5938 Image Name: 2.2.13 for initrd on TQM850L
5939 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5940 Data Size: 335725 Bytes = 327 kB = 0 MB
5941 Load Address: 00000000
5942 Entry Point: 0000000c
5943 Verifying Checksum ... OK
5949 The "bootm" command is used to boot an application that is stored in
5950 memory (RAM or Flash). In case of a Linux kernel image, the contents
5951 of the "bootargs" environment variable is passed to the kernel as
5952 parameters. You can check and modify this variable using the
5953 "printenv" and "setenv" commands:
5956 => printenv bootargs
5957 bootargs=root=/dev/ram
5959 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5961 => printenv bootargs
5962 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5965 ## Booting Linux kernel at 40020000 ...
5966 Image Name: 2.2.13 for NFS on TQM850L
5967 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5968 Data Size: 381681 Bytes = 372 kB = 0 MB
5969 Load Address: 00000000
5970 Entry Point: 0000000c
5971 Verifying Checksum ... OK
5972 Uncompressing Kernel Image ... OK
5973 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
5974 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5975 time_init: decrementer frequency = 187500000/60
5976 Calibrating delay loop... 49.77 BogoMIPS
5977 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5980 If you want to boot a Linux kernel with initial RAM disk, you pass
5981 the memory addresses of both the kernel and the initrd image (PPBCOOT
5982 format!) to the "bootm" command:
5984 => imi 40100000 40200000
5986 ## Checking Image at 40100000 ...
5987 Image Name: 2.2.13 for initrd on TQM850L
5988 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5989 Data Size: 335725 Bytes = 327 kB = 0 MB
5990 Load Address: 00000000
5991 Entry Point: 0000000c
5992 Verifying Checksum ... OK
5994 ## Checking Image at 40200000 ...
5995 Image Name: Simple Ramdisk Image
5996 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5997 Data Size: 566530 Bytes = 553 kB = 0 MB
5998 Load Address: 00000000
5999 Entry Point: 00000000
6000 Verifying Checksum ... OK
6002 => bootm 40100000 40200000
6003 ## Booting Linux kernel at 40100000 ...
6004 Image Name: 2.2.13 for initrd on TQM850L
6005 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6006 Data Size: 335725 Bytes = 327 kB = 0 MB
6007 Load Address: 00000000
6008 Entry Point: 0000000c
6009 Verifying Checksum ... OK
6010 Uncompressing Kernel Image ... OK
6011 ## Loading RAMDisk Image at 40200000 ...
6012 Image Name: Simple Ramdisk Image
6013 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6014 Data Size: 566530 Bytes = 553 kB = 0 MB
6015 Load Address: 00000000
6016 Entry Point: 00000000
6017 Verifying Checksum ... OK
6018 Loading Ramdisk ... OK
6019 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
6020 Boot arguments: root=/dev/ram
6021 time_init: decrementer frequency = 187500000/60
6022 Calibrating delay loop... 49.77 BogoMIPS
6024 RAMDISK: Compressed image found at block 0
6025 VFS: Mounted root (ext2 filesystem).
6029 Boot Linux and pass a flat device tree:
6032 First, U-Boot must be compiled with the appropriate defines. See the section
6033 titled "Linux Kernel Interface" above for a more in depth explanation. The
6034 following is an example of how to start a kernel and pass an updated
6040 oft=oftrees/mpc8540ads.dtb
6041 => tftp $oftaddr $oft
6042 Speed: 1000, full duplex
6044 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6045 Filename 'oftrees/mpc8540ads.dtb'.
6046 Load address: 0x300000
6049 Bytes transferred = 4106 (100a hex)
6050 => tftp $loadaddr $bootfile
6051 Speed: 1000, full duplex
6053 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6055 Load address: 0x200000
6056 Loading:############
6058 Bytes transferred = 1029407 (fb51f hex)
6063 => bootm $loadaddr - $oftaddr
6064 ## Booting image at 00200000 ...
6065 Image Name: Linux-2.6.17-dirty
6066 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6067 Data Size: 1029343 Bytes = 1005.2 kB
6068 Load Address: 00000000
6069 Entry Point: 00000000
6070 Verifying Checksum ... OK
6071 Uncompressing Kernel Image ... OK
6072 Booting using flat device tree at 0x300000
6073 Using MPC85xx ADS machine description
6074 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6078 More About U-Boot Image Types:
6079 ------------------------------
6081 U-Boot supports the following image types:
6083 "Standalone Programs" are directly runnable in the environment
6084 provided by U-Boot; it is expected that (if they behave
6085 well) you can continue to work in U-Boot after return from
6086 the Standalone Program.
6087 "OS Kernel Images" are usually images of some Embedded OS which
6088 will take over control completely. Usually these programs
6089 will install their own set of exception handlers, device
6090 drivers, set up the MMU, etc. - this means, that you cannot
6091 expect to re-enter U-Boot except by resetting the CPU.
6092 "RAMDisk Images" are more or less just data blocks, and their
6093 parameters (address, size) are passed to an OS kernel that is
6095 "Multi-File Images" contain several images, typically an OS
6096 (Linux) kernel image and one or more data images like
6097 RAMDisks. This construct is useful for instance when you want
6098 to boot over the network using BOOTP etc., where the boot
6099 server provides just a single image file, but you want to get
6100 for instance an OS kernel and a RAMDisk image.
6102 "Multi-File Images" start with a list of image sizes, each
6103 image size (in bytes) specified by an "uint32_t" in network
6104 byte order. This list is terminated by an "(uint32_t)0".
6105 Immediately after the terminating 0 follow the images, one by
6106 one, all aligned on "uint32_t" boundaries (size rounded up to
6107 a multiple of 4 bytes).
6109 "Firmware Images" are binary images containing firmware (like
6110 U-Boot or FPGA images) which usually will be programmed to
6113 "Script files" are command sequences that will be executed by
6114 U-Boot's command interpreter; this feature is especially
6115 useful when you configure U-Boot to use a real shell (hush)
6116 as command interpreter.
6118 Booting the Linux zImage:
6119 -------------------------
6121 On some platforms, it's possible to boot Linux zImage. This is done
6122 using the "bootz" command. The syntax of "bootz" command is the same
6123 as the syntax of "bootm" command.
6125 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6126 kernel with raw initrd images. The syntax is slightly different, the
6127 address of the initrd must be augmented by it's size, in the following
6128 format: "<initrd addres>:<initrd size>".
6134 One of the features of U-Boot is that you can dynamically load and
6135 run "standalone" applications, which can use some resources of
6136 U-Boot like console I/O functions or interrupt services.
6138 Two simple examples are included with the sources:
6143 'examples/hello_world.c' contains a small "Hello World" Demo
6144 application; it is automatically compiled when you build U-Boot.
6145 It's configured to run at address 0x00040004, so you can play with it
6149 ## Ready for S-Record download ...
6150 ~>examples/hello_world.srec
6151 1 2 3 4 5 6 7 8 9 10 11 ...
6152 [file transfer complete]
6154 ## Start Addr = 0x00040004
6156 => go 40004 Hello World! This is a test.
6157 ## Starting application at 0x00040004 ...
6168 Hit any key to exit ...
6170 ## Application terminated, rc = 0x0
6172 Another example, which demonstrates how to register a CPM interrupt
6173 handler with the U-Boot code, can be found in 'examples/timer.c'.
6174 Here, a CPM timer is set up to generate an interrupt every second.
6175 The interrupt service routine is trivial, just printing a '.'
6176 character, but this is just a demo program. The application can be
6177 controlled by the following keys:
6179 ? - print current values og the CPM Timer registers
6180 b - enable interrupts and start timer
6181 e - stop timer and disable interrupts
6182 q - quit application
6185 ## Ready for S-Record download ...
6186 ~>examples/timer.srec
6187 1 2 3 4 5 6 7 8 9 10 11 ...
6188 [file transfer complete]
6190 ## Start Addr = 0x00040004
6193 ## Starting application at 0x00040004 ...
6196 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6199 [q, b, e, ?] Set interval 1000000 us
6202 [q, b, e, ?] ........
6203 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6206 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6209 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6212 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6214 [q, b, e, ?] ...Stopping timer
6216 [q, b, e, ?] ## Application terminated, rc = 0x0
6222 Over time, many people have reported problems when trying to use the
6223 "minicom" terminal emulation program for serial download. I (wd)
6224 consider minicom to be broken, and recommend not to use it. Under
6225 Unix, I recommend to use C-Kermit for general purpose use (and
6226 especially for kermit binary protocol download ("loadb" command), and
6227 use "cu" for S-Record download ("loads" command). See
6228 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6229 for help with kermit.
6232 Nevertheless, if you absolutely want to use it try adding this
6233 configuration to your "File transfer protocols" section:
6235 Name Program Name U/D FullScr IO-Red. Multi
6236 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6237 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6243 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6244 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6246 Building requires a cross environment; it is known to work on
6247 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6248 need gmake since the Makefiles are not compatible with BSD make).
6249 Note that the cross-powerpc package does not install include files;
6250 attempting to build U-Boot will fail because <machine/ansi.h> is
6251 missing. This file has to be installed and patched manually:
6253 # cd /usr/pkg/cross/powerpc-netbsd/include
6255 # ln -s powerpc machine
6256 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6257 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6259 Native builds *don't* work due to incompatibilities between native
6260 and U-Boot include files.
6262 Booting assumes that (the first part of) the image booted is a
6263 stage-2 loader which in turn loads and then invokes the kernel
6264 proper. Loader sources will eventually appear in the NetBSD source
6265 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6266 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6269 Implementation Internals:
6270 =========================
6272 The following is not intended to be a complete description of every
6273 implementation detail. However, it should help to understand the
6274 inner workings of U-Boot and make it easier to port it to custom
6278 Initial Stack, Global Data:
6279 ---------------------------
6281 The implementation of U-Boot is complicated by the fact that U-Boot
6282 starts running out of ROM (flash memory), usually without access to
6283 system RAM (because the memory controller is not initialized yet).
6284 This means that we don't have writable Data or BSS segments, and BSS
6285 is not initialized as zero. To be able to get a C environment working
6286 at all, we have to allocate at least a minimal stack. Implementation
6287 options for this are defined and restricted by the CPU used: Some CPU
6288 models provide on-chip memory (like the IMMR area on MPC8xx and
6289 MPC826x processors), on others (parts of) the data cache can be
6290 locked as (mis-) used as memory, etc.
6292 Chris Hallinan posted a good summary of these issues to the
6293 U-Boot mailing list:
6295 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6296 From: "Chris Hallinan" <clh@net1plus.com>
6297 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6300 Correct me if I'm wrong, folks, but the way I understand it
6301 is this: Using DCACHE as initial RAM for Stack, etc, does not
6302 require any physical RAM backing up the cache. The cleverness
6303 is that the cache is being used as a temporary supply of
6304 necessary storage before the SDRAM controller is setup. It's
6305 beyond the scope of this list to explain the details, but you
6306 can see how this works by studying the cache architecture and
6307 operation in the architecture and processor-specific manuals.
6309 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6310 is another option for the system designer to use as an
6311 initial stack/RAM area prior to SDRAM being available. Either
6312 option should work for you. Using CS 4 should be fine if your
6313 board designers haven't used it for something that would
6314 cause you grief during the initial boot! It is frequently not
6317 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6318 with your processor/board/system design. The default value
6319 you will find in any recent u-boot distribution in
6320 walnut.h should work for you. I'd set it to a value larger
6321 than your SDRAM module. If you have a 64MB SDRAM module, set
6322 it above 400_0000. Just make sure your board has no resources
6323 that are supposed to respond to that address! That code in
6324 start.S has been around a while and should work as is when
6325 you get the config right.
6330 It is essential to remember this, since it has some impact on the C
6331 code for the initialization procedures:
6333 * Initialized global data (data segment) is read-only. Do not attempt
6336 * Do not use any uninitialized global data (or implicitly initialized
6337 as zero data - BSS segment) at all - this is undefined, initiali-
6338 zation is performed later (when relocating to RAM).
6340 * Stack space is very limited. Avoid big data buffers or things like
6343 Having only the stack as writable memory limits means we cannot use
6344 normal global data to share information between the code. But it
6345 turned out that the implementation of U-Boot can be greatly
6346 simplified by making a global data structure (gd_t) available to all
6347 functions. We could pass a pointer to this data as argument to _all_
6348 functions, but this would bloat the code. Instead we use a feature of
6349 the GCC compiler (Global Register Variables) to share the data: we
6350 place a pointer (gd) to the global data into a register which we
6351 reserve for this purpose.
6353 When choosing a register for such a purpose we are restricted by the
6354 relevant (E)ABI specifications for the current architecture, and by
6355 GCC's implementation.
6357 For PowerPC, the following registers have specific use:
6359 R2: reserved for system use
6360 R3-R4: parameter passing and return values
6361 R5-R10: parameter passing
6362 R13: small data area pointer
6366 (U-Boot also uses R12 as internal GOT pointer. r12
6367 is a volatile register so r12 needs to be reset when
6368 going back and forth between asm and C)
6370 ==> U-Boot will use R2 to hold a pointer to the global data
6372 Note: on PPC, we could use a static initializer (since the
6373 address of the global data structure is known at compile time),
6374 but it turned out that reserving a register results in somewhat
6375 smaller code - although the code savings are not that big (on
6376 average for all boards 752 bytes for the whole U-Boot image,
6377 624 text + 127 data).
6379 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6380 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6382 ==> U-Boot will use P3 to hold a pointer to the global data
6384 On ARM, the following registers are used:
6386 R0: function argument word/integer result
6387 R1-R3: function argument word
6388 R9: platform specific
6389 R10: stack limit (used only if stack checking is enabled)
6390 R11: argument (frame) pointer
6391 R12: temporary workspace
6394 R15: program counter
6396 ==> U-Boot will use R9 to hold a pointer to the global data
6398 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6400 On Nios II, the ABI is documented here:
6401 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6403 ==> U-Boot will use gp to hold a pointer to the global data
6405 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6406 to access small data sections, so gp is free.
6408 On NDS32, the following registers are used:
6410 R0-R1: argument/return
6412 R15: temporary register for assembler
6413 R16: trampoline register
6414 R28: frame pointer (FP)
6415 R29: global pointer (GP)
6416 R30: link register (LP)
6417 R31: stack pointer (SP)
6418 PC: program counter (PC)
6420 ==> U-Boot will use R10 to hold a pointer to the global data
6422 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6423 or current versions of GCC may "optimize" the code too much.
6428 U-Boot runs in system state and uses physical addresses, i.e. the
6429 MMU is not used either for address mapping nor for memory protection.
6431 The available memory is mapped to fixed addresses using the memory
6432 controller. In this process, a contiguous block is formed for each
6433 memory type (Flash, SDRAM, SRAM), even when it consists of several
6434 physical memory banks.
6436 U-Boot is installed in the first 128 kB of the first Flash bank (on
6437 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6438 booting and sizing and initializing DRAM, the code relocates itself
6439 to the upper end of DRAM. Immediately below the U-Boot code some
6440 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6441 configuration setting]. Below that, a structure with global Board
6442 Info data is placed, followed by the stack (growing downward).
6444 Additionally, some exception handler code is copied to the low 8 kB
6445 of DRAM (0x00000000 ... 0x00001FFF).
6447 So a typical memory configuration with 16 MB of DRAM could look like
6450 0x0000 0000 Exception Vector code
6453 0x0000 2000 Free for Application Use
6459 0x00FB FF20 Monitor Stack (Growing downward)
6460 0x00FB FFAC Board Info Data and permanent copy of global data
6461 0x00FC 0000 Malloc Arena
6464 0x00FE 0000 RAM Copy of Monitor Code
6465 ... eventually: LCD or video framebuffer
6466 ... eventually: pRAM (Protected RAM - unchanged by reset)
6467 0x00FF FFFF [End of RAM]
6470 System Initialization:
6471 ----------------------
6473 In the reset configuration, U-Boot starts at the reset entry point
6474 (on most PowerPC systems at address 0x00000100). Because of the reset
6475 configuration for CS0# this is a mirror of the on board Flash memory.
6476 To be able to re-map memory U-Boot then jumps to its link address.
6477 To be able to implement the initialization code in C, a (small!)
6478 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6479 which provide such a feature like MPC8xx or MPC8260), or in a locked
6480 part of the data cache. After that, U-Boot initializes the CPU core,
6481 the caches and the SIU.
6483 Next, all (potentially) available memory banks are mapped using a
6484 preliminary mapping. For example, we put them on 512 MB boundaries
6485 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6486 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6487 programmed for SDRAM access. Using the temporary configuration, a
6488 simple memory test is run that determines the size of the SDRAM
6491 When there is more than one SDRAM bank, and the banks are of
6492 different size, the largest is mapped first. For equal size, the first
6493 bank (CS2#) is mapped first. The first mapping is always for address
6494 0x00000000, with any additional banks following immediately to create
6495 contiguous memory starting from 0.
6497 Then, the monitor installs itself at the upper end of the SDRAM area
6498 and allocates memory for use by malloc() and for the global Board
6499 Info data; also, the exception vector code is copied to the low RAM
6500 pages, and the final stack is set up.
6502 Only after this relocation will you have a "normal" C environment;
6503 until that you are restricted in several ways, mostly because you are
6504 running from ROM, and because the code will have to be relocated to a
6508 U-Boot Porting Guide:
6509 ----------------------
6511 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6515 int main(int argc, char *argv[])
6517 sighandler_t no_more_time;
6519 signal(SIGALRM, no_more_time);
6520 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6522 if (available_money > available_manpower) {
6523 Pay consultant to port U-Boot;
6527 Download latest U-Boot source;
6529 Subscribe to u-boot mailing list;
6532 email("Hi, I am new to U-Boot, how do I get started?");
6535 Read the README file in the top level directory;
6536 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6537 Read applicable doc/*.README;
6538 Read the source, Luke;
6539 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6542 if (available_money > toLocalCurrency ($2500))
6545 Add a lot of aggravation and time;
6547 if (a similar board exists) { /* hopefully... */
6548 cp -a board/<similar> board/<myboard>
6549 cp include/configs/<similar>.h include/configs/<myboard>.h
6551 Create your own board support subdirectory;
6552 Create your own board include/configs/<myboard>.h file;
6554 Edit new board/<myboard> files
6555 Edit new include/configs/<myboard>.h
6560 Add / modify source code;
6564 email("Hi, I am having problems...");
6566 Send patch file to the U-Boot email list;
6567 if (reasonable critiques)
6568 Incorporate improvements from email list code review;
6570 Defend code as written;
6576 void no_more_time (int sig)
6585 All contributions to U-Boot should conform to the Linux kernel
6586 coding style; see the file "Documentation/CodingStyle" and the script
6587 "scripts/Lindent" in your Linux kernel source directory.
6589 Source files originating from a different project (for example the
6590 MTD subsystem) are generally exempt from these guidelines and are not
6591 reformatted to ease subsequent migration to newer versions of those
6594 Please note that U-Boot is implemented in C (and to some small parts in
6595 Assembler); no C++ is used, so please do not use C++ style comments (//)
6598 Please also stick to the following formatting rules:
6599 - remove any trailing white space
6600 - use TAB characters for indentation and vertical alignment, not spaces
6601 - make sure NOT to use DOS '\r\n' line feeds
6602 - do not add more than 2 consecutive empty lines to source files
6603 - do not add trailing empty lines to source files
6605 Submissions which do not conform to the standards may be returned
6606 with a request to reformat the changes.
6612 Since the number of patches for U-Boot is growing, we need to
6613 establish some rules. Submissions which do not conform to these rules
6614 may be rejected, even when they contain important and valuable stuff.
6616 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6618 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6619 see http://lists.denx.de/mailman/listinfo/u-boot
6621 When you send a patch, please include the following information with
6624 * For bug fixes: a description of the bug and how your patch fixes
6625 this bug. Please try to include a way of demonstrating that the
6626 patch actually fixes something.
6628 * For new features: a description of the feature and your
6631 * A CHANGELOG entry as plaintext (separate from the patch)
6633 * For major contributions, your entry to the CREDITS file
6635 * When you add support for a new board, don't forget to add a
6636 maintainer e-mail address to the boards.cfg file, too.
6638 * If your patch adds new configuration options, don't forget to
6639 document these in the README file.
6641 * The patch itself. If you are using git (which is *strongly*
6642 recommended) you can easily generate the patch using the
6643 "git format-patch". If you then use "git send-email" to send it to
6644 the U-Boot mailing list, you will avoid most of the common problems
6645 with some other mail clients.
6647 If you cannot use git, use "diff -purN OLD NEW". If your version of
6648 diff does not support these options, then get the latest version of
6651 The current directory when running this command shall be the parent
6652 directory of the U-Boot source tree (i. e. please make sure that
6653 your patch includes sufficient directory information for the
6656 We prefer patches as plain text. MIME attachments are discouraged,
6657 and compressed attachments must not be used.
6659 * If one logical set of modifications affects or creates several
6660 files, all these changes shall be submitted in a SINGLE patch file.
6662 * Changesets that contain different, unrelated modifications shall be
6663 submitted as SEPARATE patches, one patch per changeset.
6668 * Before sending the patch, run the MAKEALL script on your patched
6669 source tree and make sure that no errors or warnings are reported
6670 for any of the boards.
6672 * Keep your modifications to the necessary minimum: A patch
6673 containing several unrelated changes or arbitrary reformats will be
6674 returned with a request to re-formatting / split it.
6676 * If you modify existing code, make sure that your new code does not
6677 add to the memory footprint of the code ;-) Small is beautiful!
6678 When adding new features, these should compile conditionally only
6679 (using #ifdef), and the resulting code with the new feature
6680 disabled must not need more memory than the old code without your
6683 * Remember that there is a size limit of 100 kB per message on the
6684 u-boot mailing list. Bigger patches will be moderated. If they are
6685 reasonable and not too big, they will be acknowledged. But patches
6686 bigger than the size limit should be avoided.
projects / oweals / u-boot.git / blob