2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Board Initialisation Flow:
277 --------------------------
279 This is the intended start-up flow for boards. This should apply for both
280 SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL
281 mostly uses a separate code path, but the funtion names and roles of each
282 function are the same. Some boards or architectures may not conform to this.
283 At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this.
285 Execution starts with start.S with three functions called during init after
286 that. The purpose and limitations of each is described below.
289 - purpose: essential init to permit execution to reach board_init_f()
290 - no global_data or BSS
291 - there is no stack (ARMv7 may have one but it will soon be removed)
292 - must not set up SDRAM or use console
293 - must only do the bare minimum to allow execution to continue to
295 - this is almost never needed
296 - return normally from this function
299 - purpose: set up the machine ready for running board_init_r():
300 i.e. SDRAM and serial UART
301 - global_data is available
303 - BSS is not available, so you cannot use global/static variables,
304 only stack variables and global_data
306 Non-SPL-specific notes:
307 - dram_init() is called to set up DRAM. If already done in SPL this
311 - you can override the entire board_init_f() function with your own
313 - preloader_console_init() can be called here in extremis
314 - should set up SDRAM, and anything needed to make the UART work
315 - these is no need to clear BSS, it will be done by crt0.S
316 - must return normally from this function (don't call board_init_r()
319 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
320 this point the stack and global_data are relocated to below
321 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
325 - purpose: main execution, common code
326 - global_data is available
328 - BSS is available, all static/global variables can be used
329 - execution eventually continues to main_loop()
331 Non-SPL-specific notes:
332 - U-Boot is relocated to the top of memory and is now running from
336 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
337 CONFIG_SPL_STACK_R_ADDR points into SDRAM
338 - preloader_console_init() can be called here - typically this is
339 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
340 spl_board_init() function containing this call
341 - loads U-Boot or (in falcon mode) Linux
345 Configuration Options:
346 ----------------------
348 Configuration depends on the combination of board and CPU type; all
349 such information is kept in a configuration file
350 "include/configs/<board_name>.h".
352 Example: For a TQM823L module, all configuration settings are in
353 "include/configs/TQM823L.h".
356 Many of the options are named exactly as the corresponding Linux
357 kernel configuration options. The intention is to make it easier to
358 build a config tool - later.
361 The following options need to be configured:
363 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
365 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
367 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
368 Define exactly one, e.g. CONFIG_ATSTK1002
370 - CPU Module Type: (if CONFIG_COGENT is defined)
371 Define exactly one of
373 --- FIXME --- not tested yet:
374 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
375 CONFIG_CMA287_23, CONFIG_CMA287_50
377 - Motherboard Type: (if CONFIG_COGENT is defined)
378 Define exactly one of
379 CONFIG_CMA101, CONFIG_CMA102
381 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
382 Define one or more of
385 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
386 Define one or more of
387 CONFIG_LCD_HEARTBEAT - update a character position on
388 the LCD display every second with
391 - Marvell Family Member
392 CONFIG_SYS_MVFS - define it if you want to enable
393 multiple fs option at one time
394 for marvell soc family
396 - 8xx CPU Options: (if using an MPC8xx CPU)
397 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
398 get_gclk_freq() cannot work
399 e.g. if there is no 32KHz
400 reference PIT/RTC clock
401 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
404 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
405 CONFIG_SYS_8xx_CPUCLK_MIN
406 CONFIG_SYS_8xx_CPUCLK_MAX
407 CONFIG_8xx_CPUCLK_DEFAULT
408 See doc/README.MPC866
410 CONFIG_SYS_MEASURE_CPUCLK
412 Define this to measure the actual CPU clock instead
413 of relying on the correctness of the configured
414 values. Mostly useful for board bringup to make sure
415 the PLL is locked at the intended frequency. Note
416 that this requires a (stable) reference clock (32 kHz
417 RTC clock or CONFIG_SYS_8XX_XIN)
419 CONFIG_SYS_DELAYED_ICACHE
421 Define this option if you want to enable the
422 ICache only when Code runs from RAM.
427 Specifies that the core is a 64-bit PowerPC implementation (implements
428 the "64" category of the Power ISA). This is necessary for ePAPR
429 compliance, among other possible reasons.
431 CONFIG_SYS_FSL_TBCLK_DIV
433 Defines the core time base clock divider ratio compared to the
434 system clock. On most PQ3 devices this is 8, on newer QorIQ
435 devices it can be 16 or 32. The ratio varies from SoC to Soc.
437 CONFIG_SYS_FSL_PCIE_COMPAT
439 Defines the string to utilize when trying to match PCIe device
440 tree nodes for the given platform.
442 CONFIG_SYS_PPC_E500_DEBUG_TLB
444 Enables a temporary TLB entry to be used during boot to work
445 around limitations in e500v1 and e500v2 external debugger
446 support. This reduces the portions of the boot code where
447 breakpoints and single stepping do not work. The value of this
448 symbol should be set to the TLB1 entry to be used for this
451 CONFIG_SYS_FSL_ERRATUM_A004510
453 Enables a workaround for erratum A004510. If set,
454 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
455 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
457 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
458 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
460 Defines one or two SoC revisions (low 8 bits of SVR)
461 for which the A004510 workaround should be applied.
463 The rest of SVR is either not relevant to the decision
464 of whether the erratum is present (e.g. p2040 versus
465 p2041) or is implied by the build target, which controls
466 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
468 See Freescale App Note 4493 for more information about
471 CONFIG_A003399_NOR_WORKAROUND
472 Enables a workaround for IFC erratum A003399. It is only
473 required during NOR boot.
475 CONFIG_A008044_WORKAROUND
476 Enables a workaround for T1040/T1042 erratum A008044. It is only
477 required during NAND boot and valid for Rev 1.0 SoC revision
479 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
481 This is the value to write into CCSR offset 0x18600
482 according to the A004510 workaround.
484 CONFIG_SYS_FSL_DSP_DDR_ADDR
485 This value denotes start offset of DDR memory which is
486 connected exclusively to the DSP cores.
488 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
489 This value denotes start offset of M2 memory
490 which is directly connected to the DSP core.
492 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
493 This value denotes start offset of M3 memory which is directly
494 connected to the DSP core.
496 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
497 This value denotes start offset of DSP CCSR space.
499 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
500 Single Source Clock is clocking mode present in some of FSL SoC's.
501 In this mode, a single differential clock is used to supply
502 clocks to the sysclock, ddrclock and usbclock.
504 CONFIG_SYS_CPC_REINIT_F
505 This CONFIG is defined when the CPC is configured as SRAM at the
506 time of U-boot entry and is required to be re-initialized.
509 Indicates this SoC supports deep sleep feature. If deep sleep is
510 supported, core will start to execute uboot when wakes up.
512 - Generic CPU options:
513 CONFIG_SYS_GENERIC_GLOBAL_DATA
514 Defines global data is initialized in generic board board_init_f().
515 If this macro is defined, global data is created and cleared in
516 generic board board_init_f(). Without this macro, architecture/board
517 should initialize global data before calling board_init_f().
519 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
521 Defines the endianess of the CPU. Implementation of those
522 values is arch specific.
525 Freescale DDR driver in use. This type of DDR controller is
526 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
529 CONFIG_SYS_FSL_DDR_ADDR
530 Freescale DDR memory-mapped register base.
532 CONFIG_SYS_FSL_DDR_EMU
533 Specify emulator support for DDR. Some DDR features such as
534 deskew training are not available.
536 CONFIG_SYS_FSL_DDRC_GEN1
537 Freescale DDR1 controller.
539 CONFIG_SYS_FSL_DDRC_GEN2
540 Freescale DDR2 controller.
542 CONFIG_SYS_FSL_DDRC_GEN3
543 Freescale DDR3 controller.
545 CONFIG_SYS_FSL_DDRC_GEN4
546 Freescale DDR4 controller.
548 CONFIG_SYS_FSL_DDRC_ARM_GEN3
549 Freescale DDR3 controller for ARM-based SoCs.
552 Board config to use DDR1. It can be enabled for SoCs with
553 Freescale DDR1 or DDR2 controllers, depending on the board
557 Board config to use DDR2. It can be eanbeld for SoCs with
558 Freescale DDR2 or DDR3 controllers, depending on the board
562 Board config to use DDR3. It can be enabled for SoCs with
563 Freescale DDR3 or DDR3L controllers.
566 Board config to use DDR3L. It can be enabled for SoCs with
570 Board config to use DDR4. It can be enabled for SoCs with
573 CONFIG_SYS_FSL_IFC_BE
574 Defines the IFC controller register space as Big Endian
576 CONFIG_SYS_FSL_IFC_LE
577 Defines the IFC controller register space as Little Endian
579 CONFIG_SYS_FSL_PBL_PBI
580 It enables addition of RCW (Power on reset configuration) in built image.
581 Please refer doc/README.pblimage for more details
583 CONFIG_SYS_FSL_PBL_RCW
584 It adds PBI(pre-boot instructions) commands in u-boot build image.
585 PBI commands can be used to configure SoC before it starts the execution.
586 Please refer doc/README.pblimage for more details
589 It adds a target to create boot binary having SPL binary in PBI format
590 concatenated with u-boot binary.
592 CONFIG_SYS_FSL_DDR_BE
593 Defines the DDR controller register space as Big Endian
595 CONFIG_SYS_FSL_DDR_LE
596 Defines the DDR controller register space as Little Endian
598 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
599 Physical address from the view of DDR controllers. It is the
600 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
601 it could be different for ARM SoCs.
603 CONFIG_SYS_FSL_DDR_INTLV_256B
604 DDR controller interleaving on 256-byte. This is a special
605 interleaving mode, handled by Dickens for Freescale layerscape
608 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
609 Number of controllers used as main memory.
611 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
612 Number of controllers used for other than main memory.
614 CONFIG_SYS_FSL_SEC_BE
615 Defines the SEC controller register space as Big Endian
617 CONFIG_SYS_FSL_SEC_LE
618 Defines the SEC controller register space as Little Endian
620 - Intel Monahans options:
621 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
623 Defines the Monahans run mode to oscillator
624 ratio. Valid values are 8, 16, 24, 31. The core
625 frequency is this value multiplied by 13 MHz.
627 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
629 Defines the Monahans turbo mode to oscillator
630 ratio. Valid values are 1 (default if undefined) and
631 2. The core frequency as calculated above is multiplied
635 CONFIG_SYS_INIT_SP_OFFSET
637 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
638 pointer. This is needed for the temporary stack before
641 CONFIG_SYS_MIPS_CACHE_MODE
643 Cache operation mode for the MIPS CPU.
644 See also arch/mips/include/asm/mipsregs.h.
646 CONF_CM_CACHABLE_NO_WA
649 CONF_CM_CACHABLE_NONCOHERENT
653 CONF_CM_CACHABLE_ACCELERATED
655 CONFIG_SYS_XWAY_EBU_BOOTCFG
657 Special option for Lantiq XWAY SoCs for booting from NOR flash.
658 See also arch/mips/cpu/mips32/start.S.
660 CONFIG_XWAY_SWAP_BYTES
662 Enable compilation of tools/xway-swap-bytes needed for Lantiq
663 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
664 be swapped if a flash programmer is used.
667 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
669 Select high exception vectors of the ARM core, e.g., do not
670 clear the V bit of the c1 register of CP15.
672 CONFIG_SYS_THUMB_BUILD
674 Use this flag to build U-Boot using the Thumb instruction
675 set for ARM architectures. Thumb instruction set provides
676 better code density. For ARM architectures that support
677 Thumb2 this flag will result in Thumb2 code generated by
680 CONFIG_ARM_ERRATA_716044
681 CONFIG_ARM_ERRATA_742230
682 CONFIG_ARM_ERRATA_743622
683 CONFIG_ARM_ERRATA_751472
684 CONFIG_ARM_ERRATA_794072
685 CONFIG_ARM_ERRATA_761320
687 If set, the workarounds for these ARM errata are applied early
688 during U-Boot startup. Note that these options force the
689 workarounds to be applied; no CPU-type/version detection
690 exists, unlike the similar options in the Linux kernel. Do not
691 set these options unless they apply!
694 Generic timer clock source frequency.
696 COUNTER_FREQUENCY_REAL
697 Generic timer clock source frequency if the real clock is
698 different from COUNTER_FREQUENCY, and can only be determined
701 NOTE: The following can be machine specific errata. These
702 do have ability to provide rudimentary version and machine
703 specific checks, but expect no product checks.
704 CONFIG_ARM_ERRATA_798870
707 CONFIG_TEGRA_SUPPORT_NON_SECURE
709 Support executing U-Boot in non-secure (NS) mode. Certain
710 impossible actions will be skipped if the CPU is in NS mode,
711 such as ARM architectural timer initialization.
714 Driver model is a new framework for devices in U-Boot
715 introduced in early 2014. U-Boot is being progressively
716 moved over to this. It offers a consistent device structure,
717 supports grouping devices into classes and has built-in
718 handling of platform data and device tree.
720 To enable transition to driver model in a relatively
721 painful fashion, each subsystem can be independently
722 switched between the legacy/ad-hoc approach and the new
723 driver model using the options below. Also, many uclass
724 interfaces include compatibility features which may be
725 removed once the conversion of that subsystem is complete.
726 As a result, the API provided by the subsystem may in fact
727 not change with driver model.
729 See doc/driver-model/README.txt for more information.
733 Enable driver model. This brings in the core support,
734 including scanning of platform data on start-up. If
735 CONFIG_OF_CONTROL is enabled, the device tree will be
736 scanned also when available.
740 Enable driver model test commands. These allow you to print
741 out the driver model tree and the uclasses.
745 Enable some demo devices and the 'demo' command. These are
746 really only useful for playing around while trying to
747 understand driver model in sandbox.
751 Enable driver model in SPL. You will need to provide a
752 suitable malloc() implementation. If you are not using the
753 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
754 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
755 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
756 In most cases driver model will only allocate a few uclasses
757 and devices in SPL, so 1KB should be enable. See
758 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
763 Enable driver model for serial. This replaces
764 drivers/serial/serial.c with the serial uclass, which
765 implements serial_putc() etc. The uclass interface is
766 defined in include/serial.h.
770 Enable driver model for GPIO access. The standard GPIO
771 interface (gpio_get_value(), etc.) is then implemented by
772 the GPIO uclass. Drivers provide methods to query the
773 particular GPIOs that they provide. The uclass interface
774 is defined in include/asm-generic/gpio.h.
778 Enable driver model for SPI. The SPI slave interface
779 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
780 the SPI uclass. Drivers provide methods to access the SPI
781 buses that they control. The uclass interface is defined in
782 include/spi.h. The existing spi_slave structure is attached
783 as 'parent data' to every slave on each bus. Slaves
784 typically use driver-private data instead of extending the
789 Enable driver model for SPI flash. This SPI flash interface
790 (spi_flash_probe(), spi_flash_write(), etc.) is then
791 implemented by the SPI flash uclass. There is one standard
792 SPI flash driver which knows how to probe most chips
793 supported by U-Boot. The uclass interface is defined in
794 include/spi_flash.h, but is currently fully compatible
795 with the old interface to avoid confusion and duplication
796 during the transition parent. SPI and SPI flash must be
797 enabled together (it is not possible to use driver model
798 for one and not the other).
802 Enable driver model for the Chrome OS EC interface. This
803 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
804 but otherwise makes few changes. Since cros_ec also supports
805 I2C and LPC (which don't support driver model yet), a full
806 conversion is not yet possible.
809 ** Code size options: The following options are enabled by
810 default except in SPL. Enable them explicitly to get these
815 Enable the dm_warn() function. This can use up quite a bit
816 of space for its strings.
820 Enable registering a serial device with the stdio library.
822 CONFIG_DM_DEVICE_REMOVE
824 Enable removing of devices.
826 - Linux Kernel Interface:
829 U-Boot stores all clock information in Hz
830 internally. For binary compatibility with older Linux
831 kernels (which expect the clocks passed in the
832 bd_info data to be in MHz) the environment variable
833 "clocks_in_mhz" can be defined so that U-Boot
834 converts clock data to MHZ before passing it to the
836 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
837 "clocks_in_mhz=1" is automatically included in the
840 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
842 When transferring memsize parameter to Linux, some versions
843 expect it to be in bytes, others in MB.
844 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
848 New kernel versions are expecting firmware settings to be
849 passed using flattened device trees (based on open firmware
853 * New libfdt-based support
854 * Adds the "fdt" command
855 * The bootm command automatically updates the fdt
857 OF_CPU - The proper name of the cpus node (only required for
858 MPC512X and MPC5xxx based boards).
859 OF_SOC - The proper name of the soc node (only required for
860 MPC512X and MPC5xxx based boards).
861 OF_TBCLK - The timebase frequency.
862 OF_STDOUT_PATH - The path to the console device
864 boards with QUICC Engines require OF_QE to set UCC MAC
867 CONFIG_OF_BOARD_SETUP
869 Board code has addition modification that it wants to make
870 to the flat device tree before handing it off to the kernel
872 CONFIG_OF_SYSTEM_SETUP
874 Other code has addition modification that it wants to make
875 to the flat device tree before handing it off to the kernel.
876 This causes ft_system_setup() to be called before booting
881 This define fills in the correct boot CPU in the boot
882 param header, the default value is zero if undefined.
886 U-Boot can detect if an IDE device is present or not.
887 If not, and this new config option is activated, U-Boot
888 removes the ATA node from the DTS before booting Linux,
889 so the Linux IDE driver does not probe the device and
890 crash. This is needed for buggy hardware (uc101) where
891 no pull down resistor is connected to the signal IDE5V_DD7.
893 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
895 This setting is mandatory for all boards that have only one
896 machine type and must be used to specify the machine type
897 number as it appears in the ARM machine registry
898 (see http://www.arm.linux.org.uk/developer/machines/).
899 Only boards that have multiple machine types supported
900 in a single configuration file and the machine type is
901 runtime discoverable, do not have to use this setting.
903 - vxWorks boot parameters:
905 bootvx constructs a valid bootline using the following
906 environments variables: bootfile, ipaddr, serverip, hostname.
907 It loads the vxWorks image pointed bootfile.
909 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
910 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
911 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
912 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
914 CONFIG_SYS_VXWORKS_ADD_PARAMS
916 Add it at the end of the bootline. E.g "u=username pw=secret"
918 Note: If a "bootargs" environment is defined, it will overwride
919 the defaults discussed just above.
921 - Cache Configuration:
922 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
923 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
924 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
926 - Cache Configuration for ARM:
927 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
929 CONFIG_SYS_PL310_BASE - Physical base address of PL310
930 controller register space
935 Define this if you want support for Amba PrimeCell PL010 UARTs.
939 Define this if you want support for Amba PrimeCell PL011 UARTs.
943 If you have Amba PrimeCell PL011 UARTs, set this variable to
944 the clock speed of the UARTs.
948 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
949 define this to a list of base addresses for each (supported)
950 port. See e.g. include/configs/versatile.h
952 CONFIG_PL011_SERIAL_RLCR
954 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
955 have separate receive and transmit line control registers. Set
956 this variable to initialize the extra register.
958 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
960 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
961 boot loader that has already initialized the UART. Define this
962 variable to flush the UART at init time.
964 CONFIG_SERIAL_HW_FLOW_CONTROL
966 Define this variable to enable hw flow control in serial driver.
967 Current user of this option is drivers/serial/nsl16550.c driver
970 Depending on board, define exactly one serial port
971 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
972 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
973 console by defining CONFIG_8xx_CONS_NONE
975 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
976 port routines must be defined elsewhere
977 (i.e. serial_init(), serial_getc(), ...)
980 Enables console device for a color framebuffer. Needs following
981 defines (cf. smiLynxEM, i8042)
982 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
984 VIDEO_HW_RECTFILL graphic chip supports
987 VIDEO_HW_BITBLT graphic chip supports
988 bit-blit (cf. smiLynxEM)
989 VIDEO_VISIBLE_COLS visible pixel columns
991 VIDEO_VISIBLE_ROWS visible pixel rows
992 VIDEO_PIXEL_SIZE bytes per pixel
993 VIDEO_DATA_FORMAT graphic data format
994 (0-5, cf. cfb_console.c)
995 VIDEO_FB_ADRS framebuffer address
996 VIDEO_KBD_INIT_FCT keyboard int fct
997 (i.e. i8042_kbd_init())
998 VIDEO_TSTC_FCT test char fct
1000 VIDEO_GETC_FCT get char fct
1002 CONFIG_CONSOLE_CURSOR cursor drawing on/off
1003 (requires blink timer
1005 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
1006 CONFIG_CONSOLE_TIME display time/date info in
1008 (requires CONFIG_CMD_DATE)
1009 CONFIG_VIDEO_LOGO display Linux logo in
1011 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
1012 linux_logo.h for logo.
1013 Requires CONFIG_VIDEO_LOGO
1014 CONFIG_CONSOLE_EXTRA_INFO
1015 additional board info beside
1018 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1019 a limited number of ANSI escape sequences (cursor control,
1020 erase functions and limited graphics rendition control).
1022 When CONFIG_CFB_CONSOLE is defined, video console is
1023 default i/o. Serial console can be forced with
1024 environment 'console=serial'.
1026 When CONFIG_SILENT_CONSOLE is defined, all console
1027 messages (by U-Boot and Linux!) can be silenced with
1028 the "silent" environment variable. See
1029 doc/README.silent for more information.
1031 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1033 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1037 CONFIG_BAUDRATE - in bps
1038 Select one of the baudrates listed in
1039 CONFIG_SYS_BAUDRATE_TABLE, see below.
1040 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1042 - Console Rx buffer length
1043 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1044 the maximum receive buffer length for the SMC.
1045 This option is actual only for 82xx and 8xx possible.
1046 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1047 must be defined, to setup the maximum idle timeout for
1050 - Pre-Console Buffer:
1051 Prior to the console being initialised (i.e. serial UART
1052 initialised etc) all console output is silently discarded.
1053 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1054 buffer any console messages prior to the console being
1055 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1056 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1057 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1058 bytes are output before the console is initialised, the
1059 earlier bytes are discarded.
1061 Note that when printing the buffer a copy is made on the
1062 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
1064 'Sane' compilers will generate smaller code if
1065 CONFIG_PRE_CON_BUF_SZ is a power of 2
1067 - Safe printf() functions
1068 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1069 the printf() functions. These are defined in
1070 include/vsprintf.h and include snprintf(), vsnprintf() and
1071 so on. Code size increase is approximately 300-500 bytes.
1072 If this option is not given then these functions will
1073 silently discard their buffer size argument - this means
1074 you are not getting any overflow checking in this case.
1076 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1077 Delay before automatically booting the default image;
1078 set to -1 to disable autoboot.
1079 set to -2 to autoboot with no delay and not check for abort
1080 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1082 See doc/README.autoboot for these options that
1083 work with CONFIG_BOOTDELAY. None are required.
1084 CONFIG_BOOT_RETRY_TIME
1085 CONFIG_BOOT_RETRY_MIN
1086 CONFIG_AUTOBOOT_KEYED
1087 CONFIG_AUTOBOOT_PROMPT
1088 CONFIG_AUTOBOOT_DELAY_STR
1089 CONFIG_AUTOBOOT_STOP_STR
1090 CONFIG_ZERO_BOOTDELAY_CHECK
1091 CONFIG_RESET_TO_RETRY
1095 Only needed when CONFIG_BOOTDELAY is enabled;
1096 define a command string that is automatically executed
1097 when no character is read on the console interface
1098 within "Boot Delay" after reset.
1101 This can be used to pass arguments to the bootm
1102 command. The value of CONFIG_BOOTARGS goes into the
1103 environment value "bootargs".
1105 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1106 The value of these goes into the environment as
1107 "ramboot" and "nfsboot" respectively, and can be used
1108 as a convenience, when switching between booting from
1112 CONFIG_BOOTCOUNT_LIMIT
1113 Implements a mechanism for detecting a repeating reboot
1115 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1117 CONFIG_BOOTCOUNT_ENV
1118 If no softreset save registers are found on the hardware
1119 "bootcount" is stored in the environment. To prevent a
1120 saveenv on all reboots, the environment variable
1121 "upgrade_available" is used. If "upgrade_available" is
1122 0, "bootcount" is always 0, if "upgrade_available" is
1123 1 "bootcount" is incremented in the environment.
1124 So the Userspace Applikation must set the "upgrade_available"
1125 and "bootcount" variable to 0, if a boot was successfully.
1127 - Pre-Boot Commands:
1130 When this option is #defined, the existence of the
1131 environment variable "preboot" will be checked
1132 immediately before starting the CONFIG_BOOTDELAY
1133 countdown and/or running the auto-boot command resp.
1134 entering interactive mode.
1136 This feature is especially useful when "preboot" is
1137 automatically generated or modified. For an example
1138 see the LWMON board specific code: here "preboot" is
1139 modified when the user holds down a certain
1140 combination of keys on the (special) keyboard when
1143 - Serial Download Echo Mode:
1145 If defined to 1, all characters received during a
1146 serial download (using the "loads" command) are
1147 echoed back. This might be needed by some terminal
1148 emulations (like "cu"), but may as well just take
1149 time on others. This setting #define's the initial
1150 value of the "loads_echo" environment variable.
1152 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1153 CONFIG_KGDB_BAUDRATE
1154 Select one of the baudrates listed in
1155 CONFIG_SYS_BAUDRATE_TABLE, see below.
1157 - Monitor Functions:
1158 Monitor commands can be included or excluded
1159 from the build by using the #include files
1160 <config_cmd_all.h> and #undef'ing unwanted
1161 commands, or adding #define's for wanted commands.
1163 The default command configuration includes all commands
1164 except those marked below with a "*".
1166 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1167 CONFIG_CMD_ASKENV * ask for env variable
1168 CONFIG_CMD_BDI bdinfo
1169 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1170 CONFIG_CMD_BMP * BMP support
1171 CONFIG_CMD_BSP * Board specific commands
1172 CONFIG_CMD_BOOTD bootd
1173 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1174 CONFIG_CMD_CACHE * icache, dcache
1175 CONFIG_CMD_CLK * clock command support
1176 CONFIG_CMD_CONSOLE coninfo
1177 CONFIG_CMD_CRC32 * crc32
1178 CONFIG_CMD_DATE * support for RTC, date/time...
1179 CONFIG_CMD_DHCP * DHCP support
1180 CONFIG_CMD_DIAG * Diagnostics
1181 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1182 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1183 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1184 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1185 CONFIG_CMD_DTT * Digital Therm and Thermostat
1186 CONFIG_CMD_ECHO echo arguments
1187 CONFIG_CMD_EDITENV edit env variable
1188 CONFIG_CMD_EEPROM * EEPROM read/write support
1189 CONFIG_CMD_ELF * bootelf, bootvx
1190 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1191 CONFIG_CMD_ENV_FLAGS * display details about env flags
1192 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1193 CONFIG_CMD_EXPORTENV * export the environment
1194 CONFIG_CMD_EXT2 * ext2 command support
1195 CONFIG_CMD_EXT4 * ext4 command support
1196 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1197 that work for multiple fs types
1198 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1199 CONFIG_CMD_SAVEENV saveenv
1200 CONFIG_CMD_FDC * Floppy Disk Support
1201 CONFIG_CMD_FAT * FAT command support
1202 CONFIG_CMD_FLASH flinfo, erase, protect
1203 CONFIG_CMD_FPGA FPGA device initialization support
1204 CONFIG_CMD_FUSE * Device fuse support
1205 CONFIG_CMD_GETTIME * Get time since boot
1206 CONFIG_CMD_GO * the 'go' command (exec code)
1207 CONFIG_CMD_GREPENV * search environment
1208 CONFIG_CMD_HASH * calculate hash / digest
1209 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1210 CONFIG_CMD_I2C * I2C serial bus support
1211 CONFIG_CMD_IDE * IDE harddisk support
1212 CONFIG_CMD_IMI iminfo
1213 CONFIG_CMD_IMLS List all images found in NOR flash
1214 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1215 CONFIG_CMD_IMMAP * IMMR dump support
1216 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1217 CONFIG_CMD_IMPORTENV * import an environment
1218 CONFIG_CMD_INI * import data from an ini file into the env
1219 CONFIG_CMD_IRQ * irqinfo
1220 CONFIG_CMD_ITEST Integer/string test of 2 values
1221 CONFIG_CMD_JFFS2 * JFFS2 Support
1222 CONFIG_CMD_KGDB * kgdb
1223 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1224 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1226 CONFIG_CMD_LOADB loadb
1227 CONFIG_CMD_LOADS loads
1228 CONFIG_CMD_MD5SUM * print md5 message digest
1229 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1230 CONFIG_CMD_MEMINFO * Display detailed memory information
1231 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1233 CONFIG_CMD_MEMTEST * mtest
1234 CONFIG_CMD_MISC Misc functions like sleep etc
1235 CONFIG_CMD_MMC * MMC memory mapped support
1236 CONFIG_CMD_MII * MII utility commands
1237 CONFIG_CMD_MTDPARTS * MTD partition support
1238 CONFIG_CMD_NAND * NAND support
1239 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1240 CONFIG_CMD_NFS NFS support
1241 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1242 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1243 CONFIG_CMD_PCI * pciinfo
1244 CONFIG_CMD_PCMCIA * PCMCIA support
1245 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1247 CONFIG_CMD_PORTIO * Port I/O
1248 CONFIG_CMD_READ * Read raw data from partition
1249 CONFIG_CMD_REGINFO * Register dump
1250 CONFIG_CMD_RUN run command in env variable
1251 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1252 CONFIG_CMD_SAVES * save S record dump
1253 CONFIG_CMD_SCSI * SCSI Support
1254 CONFIG_CMD_SDRAM * print SDRAM configuration information
1255 (requires CONFIG_CMD_I2C)
1256 CONFIG_CMD_SETGETDCR Support for DCR Register access
1258 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1259 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1260 (requires CONFIG_CMD_MEMORY)
1261 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1262 CONFIG_CMD_SOURCE "source" command Support
1263 CONFIG_CMD_SPI * SPI serial bus support
1264 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1265 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1266 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1267 CONFIG_CMD_TIMER * access to the system tick timer
1268 CONFIG_CMD_USB * USB support
1269 CONFIG_CMD_CDP * Cisco Discover Protocol support
1270 CONFIG_CMD_MFSL * Microblaze FSL support
1271 CONFIG_CMD_XIMG Load part of Multi Image
1272 CONFIG_CMD_UUID * Generate random UUID or GUID string
1274 EXAMPLE: If you want all functions except of network
1275 support you can write:
1277 #include "config_cmd_all.h"
1278 #undef CONFIG_CMD_NET
1281 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1283 Note: Don't enable the "icache" and "dcache" commands
1284 (configuration option CONFIG_CMD_CACHE) unless you know
1285 what you (and your U-Boot users) are doing. Data
1286 cache cannot be enabled on systems like the 8xx or
1287 8260 (where accesses to the IMMR region must be
1288 uncached), and it cannot be disabled on all other
1289 systems where we (mis-) use the data cache to hold an
1290 initial stack and some data.
1293 XXX - this list needs to get updated!
1295 - Regular expression support:
1297 If this variable is defined, U-Boot is linked against
1298 the SLRE (Super Light Regular Expression) library,
1299 which adds regex support to some commands, as for
1300 example "env grep" and "setexpr".
1304 If this variable is defined, U-Boot will use a device tree
1305 to configure its devices, instead of relying on statically
1306 compiled #defines in the board file. This option is
1307 experimental and only available on a few boards. The device
1308 tree is available in the global data as gd->fdt_blob.
1310 U-Boot needs to get its device tree from somewhere. This can
1311 be done using one of the two options below:
1314 If this variable is defined, U-Boot will embed a device tree
1315 binary in its image. This device tree file should be in the
1316 board directory and called <soc>-<board>.dts. The binary file
1317 is then picked up in board_init_f() and made available through
1318 the global data structure as gd->blob.
1321 If this variable is defined, U-Boot will build a device tree
1322 binary. It will be called u-boot.dtb. Architecture-specific
1323 code will locate it at run-time. Generally this works by:
1325 cat u-boot.bin u-boot.dtb >image.bin
1327 and in fact, U-Boot does this for you, creating a file called
1328 u-boot-dtb.bin which is useful in the common case. You can
1329 still use the individual files if you need something more
1334 If this variable is defined, it enables watchdog
1335 support for the SoC. There must be support in the SoC
1336 specific code for a watchdog. For the 8xx and 8260
1337 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1338 register. When supported for a specific SoC is
1339 available, then no further board specific code should
1340 be needed to use it.
1343 When using a watchdog circuitry external to the used
1344 SoC, then define this variable and provide board
1345 specific code for the "hw_watchdog_reset" function.
1347 CONFIG_AT91_HW_WDT_TIMEOUT
1348 specify the timeout in seconds. default 2 seconds.
1351 CONFIG_VERSION_VARIABLE
1352 If this variable is defined, an environment variable
1353 named "ver" is created by U-Boot showing the U-Boot
1354 version as printed by the "version" command.
1355 Any change to this variable will be reverted at the
1360 When CONFIG_CMD_DATE is selected, the type of the RTC
1361 has to be selected, too. Define exactly one of the
1364 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1365 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1366 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1367 CONFIG_RTC_MC146818 - use MC146818 RTC
1368 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1369 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1370 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1371 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1372 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1373 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1374 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1375 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1376 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1379 Note that if the RTC uses I2C, then the I2C interface
1380 must also be configured. See I2C Support, below.
1383 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1385 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1386 chip-ngpio pairs that tell the PCA953X driver the number of
1387 pins supported by a particular chip.
1389 Note that if the GPIO device uses I2C, then the I2C interface
1390 must also be configured. See I2C Support, below.
1393 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1394 accesses and can checksum them or write a list of them out
1395 to memory. See the 'iotrace' command for details. This is
1396 useful for testing device drivers since it can confirm that
1397 the driver behaves the same way before and after a code
1398 change. Currently this is supported on sandbox and arm. To
1399 add support for your architecture, add '#include <iotrace.h>'
1400 to the bottom of arch/<arch>/include/asm/io.h and test.
1402 Example output from the 'iotrace stats' command is below.
1403 Note that if the trace buffer is exhausted, the checksum will
1404 still continue to operate.
1407 Start: 10000000 (buffer start address)
1408 Size: 00010000 (buffer size)
1409 Offset: 00000120 (current buffer offset)
1410 Output: 10000120 (start + offset)
1411 Count: 00000018 (number of trace records)
1412 CRC32: 9526fb66 (CRC32 of all trace records)
1414 - Timestamp Support:
1416 When CONFIG_TIMESTAMP is selected, the timestamp
1417 (date and time) of an image is printed by image
1418 commands like bootm or iminfo. This option is
1419 automatically enabled when you select CONFIG_CMD_DATE .
1421 - Partition Labels (disklabels) Supported:
1422 Zero or more of the following:
1423 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1424 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1425 Intel architecture, USB sticks, etc.
1426 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1427 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1428 bootloader. Note 2TB partition limit; see
1430 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1432 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1433 CONFIG_CMD_SCSI) you must configure support for at
1434 least one non-MTD partition type as well.
1437 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1438 board configurations files but used nowhere!
1440 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1441 be performed by calling the function
1442 ide_set_reset(int reset)
1443 which has to be defined in a board specific file
1448 Set this to enable ATAPI support.
1453 Set this to enable support for disks larger than 137GB
1454 Also look at CONFIG_SYS_64BIT_LBA.
1455 Whithout these , LBA48 support uses 32bit variables and will 'only'
1456 support disks up to 2.1TB.
1458 CONFIG_SYS_64BIT_LBA:
1459 When enabled, makes the IDE subsystem use 64bit sector addresses.
1463 At the moment only there is only support for the
1464 SYM53C8XX SCSI controller; define
1465 CONFIG_SCSI_SYM53C8XX to enable it.
1467 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1468 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1469 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1470 maximum numbers of LUNs, SCSI ID's and target
1472 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1474 The environment variable 'scsidevs' is set to the number of
1475 SCSI devices found during the last scan.
1477 - NETWORK Support (PCI):
1479 Support for Intel 8254x/8257x gigabit chips.
1482 Utility code for direct access to the SPI bus on Intel 8257x.
1483 This does not do anything useful unless you set at least one
1484 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1486 CONFIG_E1000_SPI_GENERIC
1487 Allow generic access to the SPI bus on the Intel 8257x, for
1488 example with the "sspi" command.
1491 Management command for E1000 devices. When used on devices
1492 with SPI support you can reprogram the EEPROM from U-Boot.
1494 CONFIG_E1000_FALLBACK_MAC
1495 default MAC for empty EEPROM after production.
1498 Support for Intel 82557/82559/82559ER chips.
1499 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1500 write routine for first time initialisation.
1503 Support for Digital 2114x chips.
1504 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1505 modem chip initialisation (KS8761/QS6611).
1508 Support for National dp83815 chips.
1511 Support for National dp8382[01] gigabit chips.
1513 - NETWORK Support (other):
1515 CONFIG_DRIVER_AT91EMAC
1516 Support for AT91RM9200 EMAC.
1519 Define this to use reduced MII inteface
1521 CONFIG_DRIVER_AT91EMAC_QUIET
1522 If this defined, the driver is quiet.
1523 The driver doen't show link status messages.
1525 CONFIG_CALXEDA_XGMAC
1526 Support for the Calxeda XGMAC device
1529 Support for SMSC's LAN91C96 chips.
1531 CONFIG_LAN91C96_BASE
1532 Define this to hold the physical address
1533 of the LAN91C96's I/O space
1535 CONFIG_LAN91C96_USE_32_BIT
1536 Define this to enable 32 bit addressing
1539 Support for SMSC's LAN91C111 chip
1541 CONFIG_SMC91111_BASE
1542 Define this to hold the physical address
1543 of the device (I/O space)
1545 CONFIG_SMC_USE_32_BIT
1546 Define this if data bus is 32 bits
1548 CONFIG_SMC_USE_IOFUNCS
1549 Define this to use i/o functions instead of macros
1550 (some hardware wont work with macros)
1552 CONFIG_DRIVER_TI_EMAC
1553 Support for davinci emac
1555 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1556 Define this if you have more then 3 PHYs.
1559 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1561 CONFIG_FTGMAC100_EGIGA
1562 Define this to use GE link update with gigabit PHY.
1563 Define this if FTGMAC100 is connected to gigabit PHY.
1564 If your system has 10/100 PHY only, it might not occur
1565 wrong behavior. Because PHY usually return timeout or
1566 useless data when polling gigabit status and gigabit
1567 control registers. This behavior won't affect the
1568 correctnessof 10/100 link speed update.
1571 Support for SMSC's LAN911x and LAN921x chips
1574 Define this to hold the physical address
1575 of the device (I/O space)
1577 CONFIG_SMC911X_32_BIT
1578 Define this if data bus is 32 bits
1580 CONFIG_SMC911X_16_BIT
1581 Define this if data bus is 16 bits. If your processor
1582 automatically converts one 32 bit word to two 16 bit
1583 words you may also try CONFIG_SMC911X_32_BIT.
1586 Support for Renesas on-chip Ethernet controller
1588 CONFIG_SH_ETHER_USE_PORT
1589 Define the number of ports to be used
1591 CONFIG_SH_ETHER_PHY_ADDR
1592 Define the ETH PHY's address
1594 CONFIG_SH_ETHER_CACHE_WRITEBACK
1595 If this option is set, the driver enables cache flush.
1599 Support for PWM modul on the imx6.
1603 Support TPM devices.
1606 Support for i2c bus TPM devices. Only one device
1607 per system is supported at this time.
1609 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1610 Define the the i2c bus number for the TPM device
1612 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1613 Define the TPM's address on the i2c bus
1615 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1616 Define the burst count bytes upper limit
1618 CONFIG_TPM_ATMEL_TWI
1619 Support for Atmel TWI TPM device. Requires I2C support.
1622 Support for generic parallel port TPM devices. Only one device
1623 per system is supported at this time.
1625 CONFIG_TPM_TIS_BASE_ADDRESS
1626 Base address where the generic TPM device is mapped
1627 to. Contemporary x86 systems usually map it at
1631 Add tpm monitor functions.
1632 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1633 provides monitor access to authorized functions.
1636 Define this to enable the TPM support library which provides
1637 functional interfaces to some TPM commands.
1638 Requires support for a TPM device.
1640 CONFIG_TPM_AUTH_SESSIONS
1641 Define this to enable authorized functions in the TPM library.
1642 Requires CONFIG_TPM and CONFIG_SHA1.
1645 At the moment only the UHCI host controller is
1646 supported (PIP405, MIP405, MPC5200); define
1647 CONFIG_USB_UHCI to enable it.
1648 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1649 and define CONFIG_USB_STORAGE to enable the USB
1652 Supported are USB Keyboards and USB Floppy drives
1654 MPC5200 USB requires additional defines:
1656 for 528 MHz Clock: 0x0001bbbb
1660 for differential drivers: 0x00001000
1661 for single ended drivers: 0x00005000
1662 for differential drivers on PSC3: 0x00000100
1663 for single ended drivers on PSC3: 0x00004100
1664 CONFIG_SYS_USB_EVENT_POLL
1665 May be defined to allow interrupt polling
1666 instead of using asynchronous interrupts
1668 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1669 txfilltuning field in the EHCI controller on reset.
1671 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1672 HW module registers.
1675 Define the below if you wish to use the USB console.
1676 Once firmware is rebuilt from a serial console issue the
1677 command "setenv stdin usbtty; setenv stdout usbtty" and
1678 attach your USB cable. The Unix command "dmesg" should print
1679 it has found a new device. The environment variable usbtty
1680 can be set to gserial or cdc_acm to enable your device to
1681 appear to a USB host as a Linux gserial device or a
1682 Common Device Class Abstract Control Model serial device.
1683 If you select usbtty = gserial you should be able to enumerate
1685 # modprobe usbserial vendor=0xVendorID product=0xProductID
1686 else if using cdc_acm, simply setting the environment
1687 variable usbtty to be cdc_acm should suffice. The following
1688 might be defined in YourBoardName.h
1691 Define this to build a UDC device
1694 Define this to have a tty type of device available to
1695 talk to the UDC device
1698 Define this to enable the high speed support for usb
1699 device and usbtty. If this feature is enabled, a routine
1700 int is_usbd_high_speed(void)
1701 also needs to be defined by the driver to dynamically poll
1702 whether the enumeration has succeded at high speed or full
1705 CONFIG_SYS_CONSOLE_IS_IN_ENV
1706 Define this if you want stdin, stdout &/or stderr to
1710 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1711 Derive USB clock from external clock "blah"
1712 - CONFIG_SYS_USB_EXTC_CLK 0x02
1714 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1715 Derive USB clock from brgclk
1716 - CONFIG_SYS_USB_BRG_CLK 0x04
1718 If you have a USB-IF assigned VendorID then you may wish to
1719 define your own vendor specific values either in BoardName.h
1720 or directly in usbd_vendor_info.h. If you don't define
1721 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1722 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1723 should pretend to be a Linux device to it's target host.
1725 CONFIG_USBD_MANUFACTURER
1726 Define this string as the name of your company for
1727 - CONFIG_USBD_MANUFACTURER "my company"
1729 CONFIG_USBD_PRODUCT_NAME
1730 Define this string as the name of your product
1731 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1733 CONFIG_USBD_VENDORID
1734 Define this as your assigned Vendor ID from the USB
1735 Implementors Forum. This *must* be a genuine Vendor ID
1736 to avoid polluting the USB namespace.
1737 - CONFIG_USBD_VENDORID 0xFFFF
1739 CONFIG_USBD_PRODUCTID
1740 Define this as the unique Product ID
1742 - CONFIG_USBD_PRODUCTID 0xFFFF
1744 - ULPI Layer Support:
1745 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1746 the generic ULPI layer. The generic layer accesses the ULPI PHY
1747 via the platform viewport, so you need both the genric layer and
1748 the viewport enabled. Currently only Chipidea/ARC based
1749 viewport is supported.
1750 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1751 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1752 If your ULPI phy needs a different reference clock than the
1753 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1754 the appropriate value in Hz.
1757 The MMC controller on the Intel PXA is supported. To
1758 enable this define CONFIG_MMC. The MMC can be
1759 accessed from the boot prompt by mapping the device
1760 to physical memory similar to flash. Command line is
1761 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1762 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1765 Support for Renesas on-chip MMCIF controller
1767 CONFIG_SH_MMCIF_ADDR
1768 Define the base address of MMCIF registers
1771 Define the clock frequency for MMCIF
1774 Enable the generic MMC driver
1776 CONFIG_SUPPORT_EMMC_BOOT
1777 Enable some additional features of the eMMC boot partitions.
1779 CONFIG_SUPPORT_EMMC_RPMB
1780 Enable the commands for reading, writing and programming the
1781 key for the Replay Protection Memory Block partition in eMMC.
1783 - USB Device Firmware Update (DFU) class support:
1785 This enables the USB portion of the DFU USB class
1788 This enables the command "dfu" which is used to have
1789 U-Boot create a DFU class device via USB. This command
1790 requires that the "dfu_alt_info" environment variable be
1791 set and define the alt settings to expose to the host.
1794 This enables support for exposing (e)MMC devices via DFU.
1797 This enables support for exposing NAND devices via DFU.
1800 This enables support for exposing RAM via DFU.
1801 Note: DFU spec refer to non-volatile memory usage, but
1802 allow usages beyond the scope of spec - here RAM usage,
1803 one that would help mostly the developer.
1805 CONFIG_SYS_DFU_DATA_BUF_SIZE
1806 Dfu transfer uses a buffer before writing data to the
1807 raw storage device. Make the size (in bytes) of this buffer
1808 configurable. The size of this buffer is also configurable
1809 through the "dfu_bufsiz" environment variable.
1811 CONFIG_SYS_DFU_MAX_FILE_SIZE
1812 When updating files rather than the raw storage device,
1813 we use a static buffer to copy the file into and then write
1814 the buffer once we've been given the whole file. Define
1815 this to the maximum filesize (in bytes) for the buffer.
1816 Default is 4 MiB if undefined.
1818 DFU_DEFAULT_POLL_TIMEOUT
1819 Poll timeout [ms], is the timeout a device can send to the
1820 host. The host must wait for this timeout before sending
1821 a subsequent DFU_GET_STATUS request to the device.
1823 DFU_MANIFEST_POLL_TIMEOUT
1824 Poll timeout [ms], which the device sends to the host when
1825 entering dfuMANIFEST state. Host waits this timeout, before
1826 sending again an USB request to the device.
1828 - USB Device Android Fastboot support:
1830 This enables the command "fastboot" which enables the Android
1831 fastboot mode for the platform's USB device. Fastboot is a USB
1832 protocol for downloading images, flashing and device control
1833 used on Android devices.
1834 See doc/README.android-fastboot for more information.
1836 CONFIG_ANDROID_BOOT_IMAGE
1837 This enables support for booting images which use the Android
1838 image format header.
1840 CONFIG_USB_FASTBOOT_BUF_ADDR
1841 The fastboot protocol requires a large memory buffer for
1842 downloads. Define this to the starting RAM address to use for
1845 CONFIG_USB_FASTBOOT_BUF_SIZE
1846 The fastboot protocol requires a large memory buffer for
1847 downloads. This buffer should be as large as possible for a
1848 platform. Define this to the size available RAM for fastboot.
1850 CONFIG_FASTBOOT_FLASH
1851 The fastboot protocol includes a "flash" command for writing
1852 the downloaded image to a non-volatile storage device. Define
1853 this to enable the "fastboot flash" command.
1855 CONFIG_FASTBOOT_FLASH_MMC_DEV
1856 The fastboot "flash" command requires additional information
1857 regarding the non-volatile storage device. Define this to
1858 the eMMC device that fastboot should use to store the image.
1860 CONFIG_FASTBOOT_GPT_NAME
1861 The fastboot "flash" command supports writing the downloaded
1862 image to the Protective MBR and the Primary GUID Partition
1863 Table. (Additionally, this downloaded image is post-processed
1864 to generate and write the Backup GUID Partition Table.)
1865 This occurs when the specified "partition name" on the
1866 "fastboot flash" command line matches this value.
1867 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1869 - Journaling Flash filesystem support:
1870 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1871 CONFIG_JFFS2_NAND_DEV
1872 Define these for a default partition on a NAND device
1874 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1875 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1876 Define these for a default partition on a NOR device
1878 CONFIG_SYS_JFFS_CUSTOM_PART
1879 Define this to create an own partition. You have to provide a
1880 function struct part_info* jffs2_part_info(int part_num)
1882 If you define only one JFFS2 partition you may also want to
1883 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1884 to disable the command chpart. This is the default when you
1885 have not defined a custom partition
1887 - FAT(File Allocation Table) filesystem write function support:
1890 Define this to enable support for saving memory data as a
1891 file in FAT formatted partition.
1893 This will also enable the command "fatwrite" enabling the
1894 user to write files to FAT.
1896 CBFS (Coreboot Filesystem) support
1899 Define this to enable support for reading from a Coreboot
1900 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1903 - FAT(File Allocation Table) filesystem cluster size:
1904 CONFIG_FS_FAT_MAX_CLUSTSIZE
1906 Define the max cluster size for fat operations else
1907 a default value of 65536 will be defined.
1912 Define this to enable standard (PC-Style) keyboard
1916 Standard PC keyboard driver with US (is default) and
1917 GERMAN key layout (switch via environment 'keymap=de') support.
1918 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1919 for cfb_console. Supports cursor blinking.
1922 Enables a Chrome OS keyboard using the CROS_EC interface.
1923 This uses CROS_EC to communicate with a second microcontroller
1924 which provides key scans on request.
1929 Define this to enable video support (for output to
1932 CONFIG_VIDEO_CT69000
1934 Enable Chips & Technologies 69000 Video chip
1936 CONFIG_VIDEO_SMI_LYNXEM
1937 Enable Silicon Motion SMI 712/710/810 Video chip. The
1938 video output is selected via environment 'videoout'
1939 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1942 For the CT69000 and SMI_LYNXEM drivers, videomode is
1943 selected via environment 'videomode'. Two different ways
1945 - "videomode=num" 'num' is a standard LiLo mode numbers.
1946 Following standard modes are supported (* is default):
1948 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1949 -------------+---------------------------------------------
1950 8 bits | 0x301* 0x303 0x305 0x161 0x307
1951 15 bits | 0x310 0x313 0x316 0x162 0x319
1952 16 bits | 0x311 0x314 0x317 0x163 0x31A
1953 24 bits | 0x312 0x315 0x318 ? 0x31B
1954 -------------+---------------------------------------------
1955 (i.e. setenv videomode 317; saveenv; reset;)
1957 - "videomode=bootargs" all the video parameters are parsed
1958 from the bootargs. (See drivers/video/videomodes.c)
1961 CONFIG_VIDEO_SED13806
1962 Enable Epson SED13806 driver. This driver supports 8bpp
1963 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1964 or CONFIG_VIDEO_SED13806_16BPP
1967 Enable the Freescale DIU video driver. Reference boards for
1968 SOCs that have a DIU should define this macro to enable DIU
1969 support, and should also define these other macros:
1975 CONFIG_VIDEO_SW_CURSOR
1976 CONFIG_VGA_AS_SINGLE_DEVICE
1978 CONFIG_VIDEO_BMP_LOGO
1980 The DIU driver will look for the 'video-mode' environment
1981 variable, and if defined, enable the DIU as a console during
1982 boot. See the documentation file README.video for a
1983 description of this variable.
1989 Define this to enable a custom keyboard support.
1990 This simply calls drv_keyboard_init() which must be
1991 defined in your board-specific files.
1992 The only board using this so far is RBC823.
1994 - LCD Support: CONFIG_LCD
1996 Define this to enable LCD support (for output to LCD
1997 display); also select one of the supported displays
1998 by defining one of these:
2002 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2004 CONFIG_NEC_NL6448AC33:
2006 NEC NL6448AC33-18. Active, color, single scan.
2008 CONFIG_NEC_NL6448BC20
2010 NEC NL6448BC20-08. 6.5", 640x480.
2011 Active, color, single scan.
2013 CONFIG_NEC_NL6448BC33_54
2015 NEC NL6448BC33-54. 10.4", 640x480.
2016 Active, color, single scan.
2020 Sharp 320x240. Active, color, single scan.
2021 It isn't 16x9, and I am not sure what it is.
2023 CONFIG_SHARP_LQ64D341
2025 Sharp LQ64D341 display, 640x480.
2026 Active, color, single scan.
2030 HLD1045 display, 640x480.
2031 Active, color, single scan.
2035 Optrex CBL50840-2 NF-FW 99 22 M5
2037 Hitachi LMG6912RPFC-00T
2041 320x240. Black & white.
2043 Normally display is black on white background; define
2044 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2046 CONFIG_LCD_ALIGNMENT
2048 Normally the LCD is page-aligned (typically 4KB). If this is
2049 defined then the LCD will be aligned to this value instead.
2050 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2051 here, since it is cheaper to change data cache settings on
2052 a per-section basis.
2054 CONFIG_CONSOLE_SCROLL_LINES
2056 When the console need to be scrolled, this is the number of
2057 lines to scroll by. It defaults to 1. Increasing this makes
2058 the console jump but can help speed up operation when scrolling
2063 Sometimes, for example if the display is mounted in portrait
2064 mode or even if it's mounted landscape but rotated by 180degree,
2065 we need to rotate our content of the display relative to the
2066 framebuffer, so that user can read the messages which are
2068 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
2069 initialized with a given rotation from "vl_rot" out of
2070 "vidinfo_t" which is provided by the board specific code.
2071 The value for vl_rot is coded as following (matching to
2072 fbcon=rotate:<n> linux-kernel commandline):
2073 0 = no rotation respectively 0 degree
2074 1 = 90 degree rotation
2075 2 = 180 degree rotation
2076 3 = 270 degree rotation
2078 If CONFIG_LCD_ROTATION is not defined, the console will be
2079 initialized with 0degree rotation.
2083 Support drawing of RLE8-compressed bitmaps on the LCD.
2087 Enables an 'i2c edid' command which can read EDID
2088 information over I2C from an attached LCD display.
2090 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2092 If this option is set, the environment is checked for
2093 a variable "splashimage". If found, the usual display
2094 of logo, copyright and system information on the LCD
2095 is suppressed and the BMP image at the address
2096 specified in "splashimage" is loaded instead. The
2097 console is redirected to the "nulldev", too. This
2098 allows for a "silent" boot where a splash screen is
2099 loaded very quickly after power-on.
2101 CONFIG_SPLASHIMAGE_GUARD
2103 If this option is set, then U-Boot will prevent the environment
2104 variable "splashimage" from being set to a problematic address
2105 (see README.displaying-bmps).
2106 This option is useful for targets where, due to alignment
2107 restrictions, an improperly aligned BMP image will cause a data
2108 abort. If you think you will not have problems with unaligned
2109 accesses (for example because your toolchain prevents them)
2110 there is no need to set this option.
2112 CONFIG_SPLASH_SCREEN_ALIGN
2114 If this option is set the splash image can be freely positioned
2115 on the screen. Environment variable "splashpos" specifies the
2116 position as "x,y". If a positive number is given it is used as
2117 number of pixel from left/top. If a negative number is given it
2118 is used as number of pixel from right/bottom. You can also
2119 specify 'm' for centering the image.
2122 setenv splashpos m,m
2123 => image at center of screen
2125 setenv splashpos 30,20
2126 => image at x = 30 and y = 20
2128 setenv splashpos -10,m
2129 => vertically centered image
2130 at x = dspWidth - bmpWidth - 9
2132 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2134 If this option is set, additionally to standard BMP
2135 images, gzipped BMP images can be displayed via the
2136 splashscreen support or the bmp command.
2138 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2140 If this option is set, 8-bit RLE compressed BMP images
2141 can be displayed via the splashscreen support or the
2144 - Do compressing for memory range:
2147 If this option is set, it would use zlib deflate method
2148 to compress the specified memory at its best effort.
2150 - Compression support:
2153 Enabled by default to support gzip compressed images.
2157 If this option is set, support for bzip2 compressed
2158 images is included. If not, only uncompressed and gzip
2159 compressed images are supported.
2161 NOTE: the bzip2 algorithm requires a lot of RAM, so
2162 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2167 If this option is set, support for lzma compressed
2170 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2171 requires an amount of dynamic memory that is given by the
2174 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2176 Where lc and lp stand for, respectively, Literal context bits
2177 and Literal pos bits.
2179 This value is upper-bounded by 14MB in the worst case. Anyway,
2180 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2181 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2182 a very small buffer.
2184 Use the lzmainfo tool to determinate the lc and lp values and
2185 then calculate the amount of needed dynamic memory (ensuring
2186 the appropriate CONFIG_SYS_MALLOC_LEN value).
2190 If this option is set, support for LZO compressed images
2196 The address of PHY on MII bus.
2198 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2200 The clock frequency of the MII bus
2204 If this option is set, support for speed/duplex
2205 detection of gigabit PHY is included.
2207 CONFIG_PHY_RESET_DELAY
2209 Some PHY like Intel LXT971A need extra delay after
2210 reset before any MII register access is possible.
2211 For such PHY, set this option to the usec delay
2212 required. (minimum 300usec for LXT971A)
2214 CONFIG_PHY_CMD_DELAY (ppc4xx)
2216 Some PHY like Intel LXT971A need extra delay after
2217 command issued before MII status register can be read
2222 Define a default value for the IP address to use for
2223 the default Ethernet interface, in case this is not
2224 determined through e.g. bootp.
2225 (Environment variable "ipaddr")
2227 - Server IP address:
2230 Defines a default value for the IP address of a TFTP
2231 server to contact when using the "tftboot" command.
2232 (Environment variable "serverip")
2234 CONFIG_KEEP_SERVERADDR
2236 Keeps the server's MAC address, in the env 'serveraddr'
2237 for passing to bootargs (like Linux's netconsole option)
2239 - Gateway IP address:
2242 Defines a default value for the IP address of the
2243 default router where packets to other networks are
2245 (Environment variable "gatewayip")
2250 Defines a default value for the subnet mask (or
2251 routing prefix) which is used to determine if an IP
2252 address belongs to the local subnet or needs to be
2253 forwarded through a router.
2254 (Environment variable "netmask")
2256 - Multicast TFTP Mode:
2259 Defines whether you want to support multicast TFTP as per
2260 rfc-2090; for example to work with atftp. Lets lots of targets
2261 tftp down the same boot image concurrently. Note: the Ethernet
2262 driver in use must provide a function: mcast() to join/leave a
2265 - BOOTP Recovery Mode:
2266 CONFIG_BOOTP_RANDOM_DELAY
2268 If you have many targets in a network that try to
2269 boot using BOOTP, you may want to avoid that all
2270 systems send out BOOTP requests at precisely the same
2271 moment (which would happen for instance at recovery
2272 from a power failure, when all systems will try to
2273 boot, thus flooding the BOOTP server. Defining
2274 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2275 inserted before sending out BOOTP requests. The
2276 following delays are inserted then:
2278 1st BOOTP request: delay 0 ... 1 sec
2279 2nd BOOTP request: delay 0 ... 2 sec
2280 3rd BOOTP request: delay 0 ... 4 sec
2282 BOOTP requests: delay 0 ... 8 sec
2284 CONFIG_BOOTP_ID_CACHE_SIZE
2286 BOOTP packets are uniquely identified using a 32-bit ID. The
2287 server will copy the ID from client requests to responses and
2288 U-Boot will use this to determine if it is the destination of
2289 an incoming response. Some servers will check that addresses
2290 aren't in use before handing them out (usually using an ARP
2291 ping) and therefore take up to a few hundred milliseconds to
2292 respond. Network congestion may also influence the time it
2293 takes for a response to make it back to the client. If that
2294 time is too long, U-Boot will retransmit requests. In order
2295 to allow earlier responses to still be accepted after these
2296 retransmissions, U-Boot's BOOTP client keeps a small cache of
2297 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2298 cache. The default is to keep IDs for up to four outstanding
2299 requests. Increasing this will allow U-Boot to accept offers
2300 from a BOOTP client in networks with unusually high latency.
2302 - BOOTP Random transaction ID:
2303 CONFIG_BOOTP_RANDOM_ID
2305 The standard algorithm to generate a DHCP/BOOTP transaction ID
2306 by using the MAC address and the current time stamp may not
2307 quite unlikely produce duplicate transaction IDs from different
2308 clients in the same network. This option creates a transaction
2309 ID using the rand() function. Provided that the RNG has been
2310 seeded well, this should guarantee unique transaction IDs
2313 - DHCP Advanced Options:
2314 You can fine tune the DHCP functionality by defining
2315 CONFIG_BOOTP_* symbols:
2317 CONFIG_BOOTP_SUBNETMASK
2318 CONFIG_BOOTP_GATEWAY
2319 CONFIG_BOOTP_HOSTNAME
2320 CONFIG_BOOTP_NISDOMAIN
2321 CONFIG_BOOTP_BOOTPATH
2322 CONFIG_BOOTP_BOOTFILESIZE
2325 CONFIG_BOOTP_SEND_HOSTNAME
2326 CONFIG_BOOTP_NTPSERVER
2327 CONFIG_BOOTP_TIMEOFFSET
2328 CONFIG_BOOTP_VENDOREX
2329 CONFIG_BOOTP_MAY_FAIL
2331 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2332 environment variable, not the BOOTP server.
2334 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2335 after the configured retry count, the call will fail
2336 instead of starting over. This can be used to fail over
2337 to Link-local IP address configuration if the DHCP server
2340 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2341 serverip from a DHCP server, it is possible that more
2342 than one DNS serverip is offered to the client.
2343 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2344 serverip will be stored in the additional environment
2345 variable "dnsip2". The first DNS serverip is always
2346 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2349 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2350 to do a dynamic update of a DNS server. To do this, they
2351 need the hostname of the DHCP requester.
2352 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2353 of the "hostname" environment variable is passed as
2354 option 12 to the DHCP server.
2356 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2358 A 32bit value in microseconds for a delay between
2359 receiving a "DHCP Offer" and sending the "DHCP Request".
2360 This fixes a problem with certain DHCP servers that don't
2361 respond 100% of the time to a "DHCP request". E.g. On an
2362 AT91RM9200 processor running at 180MHz, this delay needed
2363 to be *at least* 15,000 usec before a Windows Server 2003
2364 DHCP server would reply 100% of the time. I recommend at
2365 least 50,000 usec to be safe. The alternative is to hope
2366 that one of the retries will be successful but note that
2367 the DHCP timeout and retry process takes a longer than
2370 - Link-local IP address negotiation:
2371 Negotiate with other link-local clients on the local network
2372 for an address that doesn't require explicit configuration.
2373 This is especially useful if a DHCP server cannot be guaranteed
2374 to exist in all environments that the device must operate.
2376 See doc/README.link-local for more information.
2379 CONFIG_CDP_DEVICE_ID
2381 The device id used in CDP trigger frames.
2383 CONFIG_CDP_DEVICE_ID_PREFIX
2385 A two character string which is prefixed to the MAC address
2390 A printf format string which contains the ascii name of
2391 the port. Normally is set to "eth%d" which sets
2392 eth0 for the first Ethernet, eth1 for the second etc.
2394 CONFIG_CDP_CAPABILITIES
2396 A 32bit integer which indicates the device capabilities;
2397 0x00000010 for a normal host which does not forwards.
2401 An ascii string containing the version of the software.
2405 An ascii string containing the name of the platform.
2409 A 32bit integer sent on the trigger.
2411 CONFIG_CDP_POWER_CONSUMPTION
2413 A 16bit integer containing the power consumption of the
2414 device in .1 of milliwatts.
2416 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2418 A byte containing the id of the VLAN.
2420 - Status LED: CONFIG_STATUS_LED
2422 Several configurations allow to display the current
2423 status using a LED. For instance, the LED will blink
2424 fast while running U-Boot code, stop blinking as
2425 soon as a reply to a BOOTP request was received, and
2426 start blinking slow once the Linux kernel is running
2427 (supported by a status LED driver in the Linux
2428 kernel). Defining CONFIG_STATUS_LED enables this
2434 The status LED can be connected to a GPIO pin.
2435 In such cases, the gpio_led driver can be used as a
2436 status LED backend implementation. Define CONFIG_GPIO_LED
2437 to include the gpio_led driver in the U-Boot binary.
2439 CONFIG_GPIO_LED_INVERTED_TABLE
2440 Some GPIO connected LEDs may have inverted polarity in which
2441 case the GPIO high value corresponds to LED off state and
2442 GPIO low value corresponds to LED on state.
2443 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2444 with a list of GPIO LEDs that have inverted polarity.
2446 - CAN Support: CONFIG_CAN_DRIVER
2448 Defining CONFIG_CAN_DRIVER enables CAN driver support
2449 on those systems that support this (optional)
2450 feature, like the TQM8xxL modules.
2452 - I2C Support: CONFIG_SYS_I2C
2454 This enable the NEW i2c subsystem, and will allow you to use
2455 i2c commands at the u-boot command line (as long as you set
2456 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2457 based realtime clock chips or other i2c devices. See
2458 common/cmd_i2c.c for a description of the command line
2461 ported i2c driver to the new framework:
2462 - drivers/i2c/soft_i2c.c:
2463 - activate first bus with CONFIG_SYS_I2C_SOFT define
2464 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2465 for defining speed and slave address
2466 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2467 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2468 for defining speed and slave address
2469 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2470 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2471 for defining speed and slave address
2472 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2473 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2474 for defining speed and slave address
2476 - drivers/i2c/fsl_i2c.c:
2477 - activate i2c driver with CONFIG_SYS_I2C_FSL
2478 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2479 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2480 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2482 - If your board supports a second fsl i2c bus, define
2483 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2484 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2485 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2488 - drivers/i2c/tegra_i2c.c:
2489 - activate this driver with CONFIG_SYS_I2C_TEGRA
2490 - This driver adds 4 i2c buses with a fix speed from
2491 100000 and the slave addr 0!
2493 - drivers/i2c/ppc4xx_i2c.c
2494 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2495 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2496 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2498 - drivers/i2c/i2c_mxc.c
2499 - activate this driver with CONFIG_SYS_I2C_MXC
2500 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2501 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2502 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2503 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2504 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2505 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2506 If those defines are not set, default value is 100000
2507 for speed, and 0 for slave.
2508 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2509 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2511 - drivers/i2c/rcar_i2c.c:
2512 - activate this driver with CONFIG_SYS_I2C_RCAR
2513 - This driver adds 4 i2c buses
2515 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2516 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2517 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2518 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2519 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2520 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2521 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2522 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2523 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2525 - drivers/i2c/sh_i2c.c:
2526 - activate this driver with CONFIG_SYS_I2C_SH
2527 - This driver adds from 2 to 5 i2c buses
2529 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2530 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2531 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2532 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2533 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2534 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2535 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2536 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2537 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2538 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2539 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2540 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2541 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2543 - drivers/i2c/omap24xx_i2c.c
2544 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2545 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2546 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2547 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2548 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2549 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2550 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2551 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2552 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2553 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2554 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2556 - drivers/i2c/zynq_i2c.c
2557 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2558 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2559 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2561 - drivers/i2c/s3c24x0_i2c.c:
2562 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2563 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2564 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2565 with a fix speed from 100000 and the slave addr 0!
2567 - drivers/i2c/ihs_i2c.c
2568 - activate this driver with CONFIG_SYS_I2C_IHS
2569 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2570 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2571 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2572 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2573 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2574 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2575 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2576 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2577 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2578 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2579 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2580 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2584 CONFIG_SYS_NUM_I2C_BUSES
2585 Hold the number of i2c buses you want to use. If you
2586 don't use/have i2c muxes on your i2c bus, this
2587 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2590 CONFIG_SYS_I2C_DIRECT_BUS
2591 define this, if you don't use i2c muxes on your hardware.
2592 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2595 CONFIG_SYS_I2C_MAX_HOPS
2596 define how many muxes are maximal consecutively connected
2597 on one i2c bus. If you not use i2c muxes, omit this
2600 CONFIG_SYS_I2C_BUSES
2601 hold a list of buses you want to use, only used if
2602 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2603 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2604 CONFIG_SYS_NUM_I2C_BUSES = 9:
2606 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2607 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2608 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2609 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2610 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2611 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2612 {1, {I2C_NULL_HOP}}, \
2613 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2614 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2618 bus 0 on adapter 0 without a mux
2619 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2620 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2621 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2622 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2623 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2624 bus 6 on adapter 1 without a mux
2625 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2626 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2628 If you do not have i2c muxes on your board, omit this define.
2630 - Legacy I2C Support: CONFIG_HARD_I2C
2632 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2633 provides the following compelling advantages:
2635 - more than one i2c adapter is usable
2636 - approved multibus support
2637 - better i2c mux support
2639 ** Please consider updating your I2C driver now. **
2641 These enable legacy I2C serial bus commands. Defining
2642 CONFIG_HARD_I2C will include the appropriate I2C driver
2643 for the selected CPU.
2645 This will allow you to use i2c commands at the u-boot
2646 command line (as long as you set CONFIG_CMD_I2C in
2647 CONFIG_COMMANDS) and communicate with i2c based realtime
2648 clock chips. See common/cmd_i2c.c for a description of the
2649 command line interface.
2651 CONFIG_HARD_I2C selects a hardware I2C controller.
2653 There are several other quantities that must also be
2654 defined when you define CONFIG_HARD_I2C.
2656 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2657 to be the frequency (in Hz) at which you wish your i2c bus
2658 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2659 the CPU's i2c node address).
2661 Now, the u-boot i2c code for the mpc8xx
2662 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2663 and so its address should therefore be cleared to 0 (See,
2664 eg, MPC823e User's Manual p.16-473). So, set
2665 CONFIG_SYS_I2C_SLAVE to 0.
2667 CONFIG_SYS_I2C_INIT_MPC5XXX
2669 When a board is reset during an i2c bus transfer
2670 chips might think that the current transfer is still
2671 in progress. Reset the slave devices by sending start
2672 commands until the slave device responds.
2674 That's all that's required for CONFIG_HARD_I2C.
2676 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2677 then the following macros need to be defined (examples are
2678 from include/configs/lwmon.h):
2682 (Optional). Any commands necessary to enable the I2C
2683 controller or configure ports.
2685 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2689 (Only for MPC8260 CPU). The I/O port to use (the code
2690 assumes both bits are on the same port). Valid values
2691 are 0..3 for ports A..D.
2695 The code necessary to make the I2C data line active
2696 (driven). If the data line is open collector, this
2699 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2703 The code necessary to make the I2C data line tri-stated
2704 (inactive). If the data line is open collector, this
2707 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2711 Code that returns true if the I2C data line is high,
2714 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2718 If <bit> is true, sets the I2C data line high. If it
2719 is false, it clears it (low).
2721 eg: #define I2C_SDA(bit) \
2722 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2723 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2727 If <bit> is true, sets the I2C clock line high. If it
2728 is false, it clears it (low).
2730 eg: #define I2C_SCL(bit) \
2731 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2732 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2736 This delay is invoked four times per clock cycle so this
2737 controls the rate of data transfer. The data rate thus
2738 is 1 / (I2C_DELAY * 4). Often defined to be something
2741 #define I2C_DELAY udelay(2)
2743 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2745 If your arch supports the generic GPIO framework (asm/gpio.h),
2746 then you may alternatively define the two GPIOs that are to be
2747 used as SCL / SDA. Any of the previous I2C_xxx macros will
2748 have GPIO-based defaults assigned to them as appropriate.
2750 You should define these to the GPIO value as given directly to
2751 the generic GPIO functions.
2753 CONFIG_SYS_I2C_INIT_BOARD
2755 When a board is reset during an i2c bus transfer
2756 chips might think that the current transfer is still
2757 in progress. On some boards it is possible to access
2758 the i2c SCLK line directly, either by using the
2759 processor pin as a GPIO or by having a second pin
2760 connected to the bus. If this option is defined a
2761 custom i2c_init_board() routine in boards/xxx/board.c
2762 is run early in the boot sequence.
2764 CONFIG_SYS_I2C_BOARD_LATE_INIT
2766 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2767 defined a custom i2c_board_late_init() routine in
2768 boards/xxx/board.c is run AFTER the operations in i2c_init()
2769 is completed. This callpoint can be used to unreset i2c bus
2770 using CPU i2c controller register accesses for CPUs whose i2c
2771 controller provide such a method. It is called at the end of
2772 i2c_init() to allow i2c_init operations to setup the i2c bus
2773 controller on the CPU (e.g. setting bus speed & slave address).
2775 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2777 This option enables configuration of bi_iic_fast[] flags
2778 in u-boot bd_info structure based on u-boot environment
2779 variable "i2cfast". (see also i2cfast)
2781 CONFIG_I2C_MULTI_BUS
2783 This option allows the use of multiple I2C buses, each of which
2784 must have a controller. At any point in time, only one bus is
2785 active. To switch to a different bus, use the 'i2c dev' command.
2786 Note that bus numbering is zero-based.
2788 CONFIG_SYS_I2C_NOPROBES
2790 This option specifies a list of I2C devices that will be skipped
2791 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2792 is set, specify a list of bus-device pairs. Otherwise, specify
2793 a 1D array of device addresses
2796 #undef CONFIG_I2C_MULTI_BUS
2797 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2799 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2801 #define CONFIG_I2C_MULTI_BUS
2802 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2804 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2806 CONFIG_SYS_SPD_BUS_NUM
2808 If defined, then this indicates the I2C bus number for DDR SPD.
2809 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2811 CONFIG_SYS_RTC_BUS_NUM
2813 If defined, then this indicates the I2C bus number for the RTC.
2814 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2816 CONFIG_SYS_DTT_BUS_NUM
2818 If defined, then this indicates the I2C bus number for the DTT.
2819 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2821 CONFIG_SYS_I2C_DTT_ADDR:
2823 If defined, specifies the I2C address of the DTT device.
2824 If not defined, then U-Boot uses predefined value for
2825 specified DTT device.
2827 CONFIG_SOFT_I2C_READ_REPEATED_START
2829 defining this will force the i2c_read() function in
2830 the soft_i2c driver to perform an I2C repeated start
2831 between writing the address pointer and reading the
2832 data. If this define is omitted the default behaviour
2833 of doing a stop-start sequence will be used. Most I2C
2834 devices can use either method, but some require one or
2837 - SPI Support: CONFIG_SPI
2839 Enables SPI driver (so far only tested with
2840 SPI EEPROM, also an instance works with Crystal A/D and
2841 D/As on the SACSng board)
2845 Enables the driver for SPI controller on SuperH. Currently
2846 only SH7757 is supported.
2850 Enables extended (16-bit) SPI EEPROM addressing.
2851 (symmetrical to CONFIG_I2C_X)
2855 Enables a software (bit-bang) SPI driver rather than
2856 using hardware support. This is a general purpose
2857 driver that only requires three general I/O port pins
2858 (two outputs, one input) to function. If this is
2859 defined, the board configuration must define several
2860 SPI configuration items (port pins to use, etc). For
2861 an example, see include/configs/sacsng.h.
2865 Enables a hardware SPI driver for general-purpose reads
2866 and writes. As with CONFIG_SOFT_SPI, the board configuration
2867 must define a list of chip-select function pointers.
2868 Currently supported on some MPC8xxx processors. For an
2869 example, see include/configs/mpc8349emds.h.
2873 Enables the driver for the SPI controllers on i.MX and MXC
2874 SoCs. Currently i.MX31/35/51 are supported.
2876 CONFIG_SYS_SPI_MXC_WAIT
2877 Timeout for waiting until spi transfer completed.
2878 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2880 - FPGA Support: CONFIG_FPGA
2882 Enables FPGA subsystem.
2884 CONFIG_FPGA_<vendor>
2886 Enables support for specific chip vendors.
2889 CONFIG_FPGA_<family>
2891 Enables support for FPGA family.
2892 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2896 Specify the number of FPGA devices to support.
2898 CONFIG_CMD_FPGA_LOADMK
2900 Enable support for fpga loadmk command
2902 CONFIG_CMD_FPGA_LOADP
2904 Enable support for fpga loadp command - load partial bitstream
2906 CONFIG_CMD_FPGA_LOADBP
2908 Enable support for fpga loadbp command - load partial bitstream
2911 CONFIG_SYS_FPGA_PROG_FEEDBACK
2913 Enable printing of hash marks during FPGA configuration.
2915 CONFIG_SYS_FPGA_CHECK_BUSY
2917 Enable checks on FPGA configuration interface busy
2918 status by the configuration function. This option
2919 will require a board or device specific function to
2924 If defined, a function that provides delays in the FPGA
2925 configuration driver.
2927 CONFIG_SYS_FPGA_CHECK_CTRLC
2928 Allow Control-C to interrupt FPGA configuration
2930 CONFIG_SYS_FPGA_CHECK_ERROR
2932 Check for configuration errors during FPGA bitfile
2933 loading. For example, abort during Virtex II
2934 configuration if the INIT_B line goes low (which
2935 indicated a CRC error).
2937 CONFIG_SYS_FPGA_WAIT_INIT
2939 Maximum time to wait for the INIT_B line to de-assert
2940 after PROB_B has been de-asserted during a Virtex II
2941 FPGA configuration sequence. The default time is 500
2944 CONFIG_SYS_FPGA_WAIT_BUSY
2946 Maximum time to wait for BUSY to de-assert during
2947 Virtex II FPGA configuration. The default is 5 ms.
2949 CONFIG_SYS_FPGA_WAIT_CONFIG
2951 Time to wait after FPGA configuration. The default is
2954 - Configuration Management:
2957 Some SoCs need special image types (e.g. U-Boot binary
2958 with a special header) as build targets. By defining
2959 CONFIG_BUILD_TARGET in the SoC / board header, this
2960 special image will be automatically built upon calling
2965 If defined, this string will be added to the U-Boot
2966 version information (U_BOOT_VERSION)
2968 - Vendor Parameter Protection:
2970 U-Boot considers the values of the environment
2971 variables "serial#" (Board Serial Number) and
2972 "ethaddr" (Ethernet Address) to be parameters that
2973 are set once by the board vendor / manufacturer, and
2974 protects these variables from casual modification by
2975 the user. Once set, these variables are read-only,
2976 and write or delete attempts are rejected. You can
2977 change this behaviour:
2979 If CONFIG_ENV_OVERWRITE is #defined in your config
2980 file, the write protection for vendor parameters is
2981 completely disabled. Anybody can change or delete
2984 Alternatively, if you define _both_ an ethaddr in the
2985 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2986 Ethernet address is installed in the environment,
2987 which can be changed exactly ONCE by the user. [The
2988 serial# is unaffected by this, i. e. it remains
2991 The same can be accomplished in a more flexible way
2992 for any variable by configuring the type of access
2993 to allow for those variables in the ".flags" variable
2994 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2999 Define this variable to enable the reservation of
3000 "protected RAM", i. e. RAM which is not overwritten
3001 by U-Boot. Define CONFIG_PRAM to hold the number of
3002 kB you want to reserve for pRAM. You can overwrite
3003 this default value by defining an environment
3004 variable "pram" to the number of kB you want to
3005 reserve. Note that the board info structure will
3006 still show the full amount of RAM. If pRAM is
3007 reserved, a new environment variable "mem" will
3008 automatically be defined to hold the amount of
3009 remaining RAM in a form that can be passed as boot
3010 argument to Linux, for instance like that:
3012 setenv bootargs ... mem=\${mem}
3015 This way you can tell Linux not to use this memory,
3016 either, which results in a memory region that will
3017 not be affected by reboots.
3019 *WARNING* If your board configuration uses automatic
3020 detection of the RAM size, you must make sure that
3021 this memory test is non-destructive. So far, the
3022 following board configurations are known to be
3025 IVMS8, IVML24, SPD8xx, TQM8xxL,
3026 HERMES, IP860, RPXlite, LWMON,
3029 - Access to physical memory region (> 4GB)
3030 Some basic support is provided for operations on memory not
3031 normally accessible to U-Boot - e.g. some architectures
3032 support access to more than 4GB of memory on 32-bit
3033 machines using physical address extension or similar.
3034 Define CONFIG_PHYSMEM to access this basic support, which
3035 currently only supports clearing the memory.
3040 Define this variable to stop the system in case of a
3041 fatal error, so that you have to reset it manually.
3042 This is probably NOT a good idea for an embedded
3043 system where you want the system to reboot
3044 automatically as fast as possible, but it may be
3045 useful during development since you can try to debug
3046 the conditions that lead to the situation.
3048 CONFIG_NET_RETRY_COUNT
3050 This variable defines the number of retries for
3051 network operations like ARP, RARP, TFTP, or BOOTP
3052 before giving up the operation. If not defined, a
3053 default value of 5 is used.
3057 Timeout waiting for an ARP reply in milliseconds.
3061 Timeout in milliseconds used in NFS protocol.
3062 If you encounter "ERROR: Cannot umount" in nfs command,
3063 try longer timeout such as
3064 #define CONFIG_NFS_TIMEOUT 10000UL
3066 - Command Interpreter:
3067 CONFIG_AUTO_COMPLETE
3069 Enable auto completion of commands using TAB.
3071 CONFIG_SYS_PROMPT_HUSH_PS2
3073 This defines the secondary prompt string, which is
3074 printed when the command interpreter needs more input
3075 to complete a command. Usually "> ".
3079 In the current implementation, the local variables
3080 space and global environment variables space are
3081 separated. Local variables are those you define by
3082 simply typing `name=value'. To access a local
3083 variable later on, you have write `$name' or
3084 `${name}'; to execute the contents of a variable
3085 directly type `$name' at the command prompt.
3087 Global environment variables are those you use
3088 setenv/printenv to work with. To run a command stored
3089 in such a variable, you need to use the run command,
3090 and you must not use the '$' sign to access them.
3092 To store commands and special characters in a
3093 variable, please use double quotation marks
3094 surrounding the whole text of the variable, instead
3095 of the backslashes before semicolons and special
3098 - Command Line Editing and History:
3099 CONFIG_CMDLINE_EDITING
3101 Enable editing and History functions for interactive
3102 command line input operations
3104 - Default Environment:
3105 CONFIG_EXTRA_ENV_SETTINGS
3107 Define this to contain any number of null terminated
3108 strings (variable = value pairs) that will be part of
3109 the default environment compiled into the boot image.
3111 For example, place something like this in your
3112 board's config file:
3114 #define CONFIG_EXTRA_ENV_SETTINGS \
3118 Warning: This method is based on knowledge about the
3119 internal format how the environment is stored by the
3120 U-Boot code. This is NOT an official, exported
3121 interface! Although it is unlikely that this format
3122 will change soon, there is no guarantee either.
3123 You better know what you are doing here.
3125 Note: overly (ab)use of the default environment is
3126 discouraged. Make sure to check other ways to preset
3127 the environment like the "source" command or the
3130 CONFIG_ENV_VARS_UBOOT_CONFIG
3132 Define this in order to add variables describing the
3133 U-Boot build configuration to the default environment.
3134 These will be named arch, cpu, board, vendor, and soc.
3136 Enabling this option will cause the following to be defined:
3144 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3146 Define this in order to add variables describing certain
3147 run-time determined information about the hardware to the
3148 environment. These will be named board_name, board_rev.
3150 CONFIG_DELAY_ENVIRONMENT
3152 Normally the environment is loaded when the board is
3153 initialised so that it is available to U-Boot. This inhibits
3154 that so that the environment is not available until
3155 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3156 this is instead controlled by the value of
3157 /config/load-environment.
3159 - Parallel Flash support:
3162 Traditionally U-boot was run on systems with parallel NOR
3163 flash. This option is used to disable support for parallel NOR
3164 flash. This option should be defined if the board does not have
3167 If this option is not defined one of the generic flash drivers
3168 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
3169 selected or the board must provide an implementation of the
3170 flash API (see include/flash.h).
3172 - DataFlash Support:
3173 CONFIG_HAS_DATAFLASH
3175 Defining this option enables DataFlash features and
3176 allows to read/write in Dataflash via the standard
3179 - Serial Flash support
3182 Defining this option enables SPI flash commands
3183 'sf probe/read/write/erase/update'.
3185 Usage requires an initial 'probe' to define the serial
3186 flash parameters, followed by read/write/erase/update
3189 The following defaults may be provided by the platform
3190 to handle the common case when only a single serial
3191 flash is present on the system.
3193 CONFIG_SF_DEFAULT_BUS Bus identifier
3194 CONFIG_SF_DEFAULT_CS Chip-select
3195 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3196 CONFIG_SF_DEFAULT_SPEED in Hz
3200 Define this option to include a destructive SPI flash
3203 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3205 Define this option to use the Bank addr/Extended addr
3206 support on SPI flashes which has size > 16Mbytes.
3208 CONFIG_SF_DUAL_FLASH Dual flash memories
3210 Define this option to use dual flash support where two flash
3211 memories can be connected with a given cs line.
3212 Currently Xilinx Zynq qspi supports these type of connections.
3214 CONFIG_SPI_FLASH_MTD spi-flash MTD layer
3216 Define this option to use mtd support for spi flash layer, this
3217 adapter is for translating mtd_read/mtd_write commands into
3218 spi_flash_read/spi_flash_write commands. It is not intended to
3219 use it within sf_cmd or the SPI flash subsystem. Such an adapter
3220 is needed for subsystems like UBI which can only operate on top
3223 CONFIG_SPI_FLASH_DATAFLASH SPI based Dataflash
3225 Define this option to access AT45xxx Dataflash chips support
3226 using spi flash interface.
3228 - SystemACE Support:
3231 Adding this option adds support for Xilinx SystemACE
3232 chips attached via some sort of local bus. The address
3233 of the chip must also be defined in the
3234 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3236 #define CONFIG_SYSTEMACE
3237 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3239 When SystemACE support is added, the "ace" device type
3240 becomes available to the fat commands, i.e. fatls.
3242 - TFTP Fixed UDP Port:
3245 If this is defined, the environment variable tftpsrcp
3246 is used to supply the TFTP UDP source port value.
3247 If tftpsrcp isn't defined, the normal pseudo-random port
3248 number generator is used.
3250 Also, the environment variable tftpdstp is used to supply
3251 the TFTP UDP destination port value. If tftpdstp isn't
3252 defined, the normal port 69 is used.
3254 The purpose for tftpsrcp is to allow a TFTP server to
3255 blindly start the TFTP transfer using the pre-configured
3256 target IP address and UDP port. This has the effect of
3257 "punching through" the (Windows XP) firewall, allowing
3258 the remainder of the TFTP transfer to proceed normally.
3259 A better solution is to properly configure the firewall,
3260 but sometimes that is not allowed.
3265 This enables a generic 'hash' command which can produce
3266 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3270 Enable the hash verify command (hash -v). This adds to code
3273 CONFIG_SHA1 - This option enables support of hashing using SHA1
3274 algorithm. The hash is calculated in software.
3275 CONFIG_SHA256 - This option enables support of hashing using
3276 SHA256 algorithm. The hash is calculated in software.
3277 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3278 for SHA1/SHA256 hashing.
3279 This affects the 'hash' command and also the
3280 hash_lookup_algo() function.
3281 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3282 hardware-acceleration for SHA1/SHA256 progressive hashing.
3283 Data can be streamed in a block at a time and the hashing
3284 is performed in hardware.
3286 Note: There is also a sha1sum command, which should perhaps
3287 be deprecated in favour of 'hash sha1'.
3289 - Freescale i.MX specific commands:
3290 CONFIG_CMD_HDMIDETECT
3291 This enables 'hdmidet' command which returns true if an
3292 HDMI monitor is detected. This command is i.MX 6 specific.
3295 This enables the 'bmode' (bootmode) command for forcing
3296 a boot from specific media.
3298 This is useful for forcing the ROM's usb downloader to
3299 activate upon a watchdog reset which is nice when iterating
3300 on U-Boot. Using the reset button or running bmode normal
3301 will set it back to normal. This command currently
3302 supports i.MX53 and i.MX6.
3307 This enables the RSA algorithm used for FIT image verification
3308 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3310 The Modular Exponentiation algorithm in RSA is implemented using
3311 driver model. So CONFIG_DM needs to be enabled by default for this
3312 library to function.
3314 The signing part is build into mkimage regardless of this
3315 option. The software based modular exponentiation is built into
3316 mkimage irrespective of this option.
3318 - bootcount support:
3319 CONFIG_BOOTCOUNT_LIMIT
3321 This enables the bootcounter support, see:
3322 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3325 enable special bootcounter support on at91sam9xe based boards.
3327 enable special bootcounter support on blackfin based boards.
3329 enable special bootcounter support on da850 based boards.
3330 CONFIG_BOOTCOUNT_RAM
3331 enable support for the bootcounter in RAM
3332 CONFIG_BOOTCOUNT_I2C
3333 enable support for the bootcounter on an i2c (like RTC) device.
3334 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3335 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3337 CONFIG_BOOTCOUNT_ALEN = address len
3339 - Show boot progress:
3340 CONFIG_SHOW_BOOT_PROGRESS
3342 Defining this option allows to add some board-
3343 specific code (calling a user-provided function
3344 "show_boot_progress(int)") that enables you to show
3345 the system's boot progress on some display (for
3346 example, some LED's) on your board. At the moment,
3347 the following checkpoints are implemented:
3350 Legacy uImage format:
3353 1 common/cmd_bootm.c before attempting to boot an image
3354 -1 common/cmd_bootm.c Image header has bad magic number
3355 2 common/cmd_bootm.c Image header has correct magic number
3356 -2 common/cmd_bootm.c Image header has bad checksum
3357 3 common/cmd_bootm.c Image header has correct checksum
3358 -3 common/cmd_bootm.c Image data has bad checksum
3359 4 common/cmd_bootm.c Image data has correct checksum
3360 -4 common/cmd_bootm.c Image is for unsupported architecture
3361 5 common/cmd_bootm.c Architecture check OK
3362 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3363 6 common/cmd_bootm.c Image Type check OK
3364 -6 common/cmd_bootm.c gunzip uncompression error
3365 -7 common/cmd_bootm.c Unimplemented compression type
3366 7 common/cmd_bootm.c Uncompression OK
3367 8 common/cmd_bootm.c No uncompress/copy overwrite error
3368 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3370 9 common/image.c Start initial ramdisk verification
3371 -10 common/image.c Ramdisk header has bad magic number
3372 -11 common/image.c Ramdisk header has bad checksum
3373 10 common/image.c Ramdisk header is OK
3374 -12 common/image.c Ramdisk data has bad checksum
3375 11 common/image.c Ramdisk data has correct checksum
3376 12 common/image.c Ramdisk verification complete, start loading
3377 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3378 13 common/image.c Start multifile image verification
3379 14 common/image.c No initial ramdisk, no multifile, continue.
3381 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3383 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3384 -31 post/post.c POST test failed, detected by post_output_backlog()
3385 -32 post/post.c POST test failed, detected by post_run_single()
3387 34 common/cmd_doc.c before loading a Image from a DOC device
3388 -35 common/cmd_doc.c Bad usage of "doc" command
3389 35 common/cmd_doc.c correct usage of "doc" command
3390 -36 common/cmd_doc.c No boot device
3391 36 common/cmd_doc.c correct boot device
3392 -37 common/cmd_doc.c Unknown Chip ID on boot device
3393 37 common/cmd_doc.c correct chip ID found, device available
3394 -38 common/cmd_doc.c Read Error on boot device
3395 38 common/cmd_doc.c reading Image header from DOC device OK
3396 -39 common/cmd_doc.c Image header has bad magic number
3397 39 common/cmd_doc.c Image header has correct magic number
3398 -40 common/cmd_doc.c Error reading Image from DOC device
3399 40 common/cmd_doc.c Image header has correct magic number
3400 41 common/cmd_ide.c before loading a Image from a IDE device
3401 -42 common/cmd_ide.c Bad usage of "ide" command
3402 42 common/cmd_ide.c correct usage of "ide" command
3403 -43 common/cmd_ide.c No boot device
3404 43 common/cmd_ide.c boot device found
3405 -44 common/cmd_ide.c Device not available
3406 44 common/cmd_ide.c Device available
3407 -45 common/cmd_ide.c wrong partition selected
3408 45 common/cmd_ide.c partition selected
3409 -46 common/cmd_ide.c Unknown partition table
3410 46 common/cmd_ide.c valid partition table found
3411 -47 common/cmd_ide.c Invalid partition type
3412 47 common/cmd_ide.c correct partition type
3413 -48 common/cmd_ide.c Error reading Image Header on boot device
3414 48 common/cmd_ide.c reading Image Header from IDE device OK
3415 -49 common/cmd_ide.c Image header has bad magic number
3416 49 common/cmd_ide.c Image header has correct magic number
3417 -50 common/cmd_ide.c Image header has bad checksum
3418 50 common/cmd_ide.c Image header has correct checksum
3419 -51 common/cmd_ide.c Error reading Image from IDE device
3420 51 common/cmd_ide.c reading Image from IDE device OK
3421 52 common/cmd_nand.c before loading a Image from a NAND device
3422 -53 common/cmd_nand.c Bad usage of "nand" command
3423 53 common/cmd_nand.c correct usage of "nand" command
3424 -54 common/cmd_nand.c No boot device
3425 54 common/cmd_nand.c boot device found
3426 -55 common/cmd_nand.c Unknown Chip ID on boot device
3427 55 common/cmd_nand.c correct chip ID found, device available
3428 -56 common/cmd_nand.c Error reading Image Header on boot device
3429 56 common/cmd_nand.c reading Image Header from NAND device OK
3430 -57 common/cmd_nand.c Image header has bad magic number
3431 57 common/cmd_nand.c Image header has correct magic number
3432 -58 common/cmd_nand.c Error reading Image from NAND device
3433 58 common/cmd_nand.c reading Image from NAND device OK
3435 -60 common/env_common.c Environment has a bad CRC, using default
3437 64 net/eth.c starting with Ethernet configuration.
3438 -64 net/eth.c no Ethernet found.
3439 65 net/eth.c Ethernet found.
3441 -80 common/cmd_net.c usage wrong
3442 80 common/cmd_net.c before calling net_loop()
3443 -81 common/cmd_net.c some error in net_loop() occurred
3444 81 common/cmd_net.c net_loop() back without error
3445 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3446 82 common/cmd_net.c trying automatic boot
3447 83 common/cmd_net.c running "source" command
3448 -83 common/cmd_net.c some error in automatic boot or "source" command
3449 84 common/cmd_net.c end without errors
3454 100 common/cmd_bootm.c Kernel FIT Image has correct format
3455 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3456 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3457 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3458 102 common/cmd_bootm.c Kernel unit name specified
3459 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3460 103 common/cmd_bootm.c Found configuration node
3461 104 common/cmd_bootm.c Got kernel subimage node offset
3462 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3463 105 common/cmd_bootm.c Kernel subimage hash verification OK
3464 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3465 106 common/cmd_bootm.c Architecture check OK
3466 -106 common/cmd_bootm.c Kernel subimage has wrong type
3467 107 common/cmd_bootm.c Kernel subimage type OK
3468 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3469 108 common/cmd_bootm.c Got kernel subimage data/size
3470 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3471 -109 common/cmd_bootm.c Can't get kernel subimage type
3472 -110 common/cmd_bootm.c Can't get kernel subimage comp
3473 -111 common/cmd_bootm.c Can't get kernel subimage os
3474 -112 common/cmd_bootm.c Can't get kernel subimage load address
3475 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3477 120 common/image.c Start initial ramdisk verification
3478 -120 common/image.c Ramdisk FIT image has incorrect format
3479 121 common/image.c Ramdisk FIT image has correct format
3480 122 common/image.c No ramdisk subimage unit name, using configuration
3481 -122 common/image.c Can't get configuration for ramdisk subimage
3482 123 common/image.c Ramdisk unit name specified
3483 -124 common/image.c Can't get ramdisk subimage node offset
3484 125 common/image.c Got ramdisk subimage node offset
3485 -125 common/image.c Ramdisk subimage hash verification failed
3486 126 common/image.c Ramdisk subimage hash verification OK
3487 -126 common/image.c Ramdisk subimage for unsupported architecture
3488 127 common/image.c Architecture check OK
3489 -127 common/image.c Can't get ramdisk subimage data/size
3490 128 common/image.c Got ramdisk subimage data/size
3491 129 common/image.c Can't get ramdisk load address
3492 -129 common/image.c Got ramdisk load address
3494 -130 common/cmd_doc.c Incorrect FIT image format
3495 131 common/cmd_doc.c FIT image format OK
3497 -140 common/cmd_ide.c Incorrect FIT image format
3498 141 common/cmd_ide.c FIT image format OK
3500 -150 common/cmd_nand.c Incorrect FIT image format
3501 151 common/cmd_nand.c FIT image format OK
3503 - legacy image format:
3504 CONFIG_IMAGE_FORMAT_LEGACY
3505 enables the legacy image format support in U-Boot.
3508 enabled if CONFIG_FIT_SIGNATURE is not defined.
3510 CONFIG_DISABLE_IMAGE_LEGACY
3511 disable the legacy image format
3513 This define is introduced, as the legacy image format is
3514 enabled per default for backward compatibility.
3516 - FIT image support:
3518 Enable support for the FIT uImage format.
3520 CONFIG_FIT_BEST_MATCH
3521 When no configuration is explicitly selected, default to the
3522 one whose fdt's compatibility field best matches that of
3523 U-Boot itself. A match is considered "best" if it matches the
3524 most specific compatibility entry of U-Boot's fdt's root node.
3525 The order of entries in the configuration's fdt is ignored.
3527 CONFIG_FIT_SIGNATURE
3528 This option enables signature verification of FIT uImages,
3529 using a hash signed and verified using RSA. If
3530 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3531 hashing is available using hardware, RSA library will use it.
3532 See doc/uImage.FIT/signature.txt for more details.
3534 WARNING: When relying on signed FIT images with required
3535 signature check the legacy image format is default
3536 disabled. If a board need legacy image format support
3537 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3539 CONFIG_FIT_DISABLE_SHA256
3540 Supporting SHA256 hashes has quite an impact on binary size.
3541 For constrained systems sha256 hash support can be disabled
3544 - Standalone program support:
3545 CONFIG_STANDALONE_LOAD_ADDR
3547 This option defines a board specific value for the
3548 address where standalone program gets loaded, thus
3549 overwriting the architecture dependent default
3552 - Frame Buffer Address:
3555 Define CONFIG_FB_ADDR if you want to use specific
3556 address for frame buffer. This is typically the case
3557 when using a graphics controller has separate video
3558 memory. U-Boot will then place the frame buffer at
3559 the given address instead of dynamically reserving it
3560 in system RAM by calling lcd_setmem(), which grabs
3561 the memory for the frame buffer depending on the
3562 configured panel size.
3564 Please see board_init_f function.
3566 - Automatic software updates via TFTP server
3568 CONFIG_UPDATE_TFTP_CNT_MAX
3569 CONFIG_UPDATE_TFTP_MSEC_MAX
3571 These options enable and control the auto-update feature;
3572 for a more detailed description refer to doc/README.update.
3574 - MTD Support (mtdparts command, UBI support)
3577 Adds the MTD device infrastructure from the Linux kernel.
3578 Needed for mtdparts command support.
3580 CONFIG_MTD_PARTITIONS
3582 Adds the MTD partitioning infrastructure from the Linux
3583 kernel. Needed for UBI support.
3588 Adds commands for interacting with MTD partitions formatted
3589 with the UBI flash translation layer
3591 Requires also defining CONFIG_RBTREE
3593 CONFIG_UBI_SILENCE_MSG
3595 Make the verbose messages from UBI stop printing. This leaves
3596 warnings and errors enabled.
3599 CONFIG_MTD_UBI_WL_THRESHOLD
3600 This parameter defines the maximum difference between the highest
3601 erase counter value and the lowest erase counter value of eraseblocks
3602 of UBI devices. When this threshold is exceeded, UBI starts performing
3603 wear leveling by means of moving data from eraseblock with low erase
3604 counter to eraseblocks with high erase counter.
3606 The default value should be OK for SLC NAND flashes, NOR flashes and
3607 other flashes which have eraseblock life-cycle 100000 or more.
3608 However, in case of MLC NAND flashes which typically have eraseblock
3609 life-cycle less than 10000, the threshold should be lessened (e.g.,
3610 to 128 or 256, although it does not have to be power of 2).
3614 CONFIG_MTD_UBI_BEB_LIMIT
3615 This option specifies the maximum bad physical eraseblocks UBI
3616 expects on the MTD device (per 1024 eraseblocks). If the
3617 underlying flash does not admit of bad eraseblocks (e.g. NOR
3618 flash), this value is ignored.
3620 NAND datasheets often specify the minimum and maximum NVM
3621 (Number of Valid Blocks) for the flashes' endurance lifetime.
3622 The maximum expected bad eraseblocks per 1024 eraseblocks
3623 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3624 which gives 20 for most NANDs (MaxNVB is basically the total
3625 count of eraseblocks on the chip).
3627 To put it differently, if this value is 20, UBI will try to
3628 reserve about 1.9% of physical eraseblocks for bad blocks
3629 handling. And that will be 1.9% of eraseblocks on the entire
3630 NAND chip, not just the MTD partition UBI attaches. This means
3631 that if you have, say, a NAND flash chip admits maximum 40 bad
3632 eraseblocks, and it is split on two MTD partitions of the same
3633 size, UBI will reserve 40 eraseblocks when attaching a
3638 CONFIG_MTD_UBI_FASTMAP
3639 Fastmap is a mechanism which allows attaching an UBI device
3640 in nearly constant time. Instead of scanning the whole MTD device it
3641 only has to locate a checkpoint (called fastmap) on the device.
3642 The on-flash fastmap contains all information needed to attach
3643 the device. Using fastmap makes only sense on large devices where
3644 attaching by scanning takes long. UBI will not automatically install
3645 a fastmap on old images, but you can set the UBI parameter
3646 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3647 that fastmap-enabled images are still usable with UBI implementations
3648 without fastmap support. On typical flash devices the whole fastmap
3649 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3651 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3652 Set this parameter to enable fastmap automatically on images
3659 Adds commands for interacting with UBI volumes formatted as
3660 UBIFS. UBIFS is read-only in u-boot.
3662 Requires UBI support as well as CONFIG_LZO
3664 CONFIG_UBIFS_SILENCE_MSG
3666 Make the verbose messages from UBIFS stop printing. This leaves
3667 warnings and errors enabled.
3671 Enable building of SPL globally.
3674 LDSCRIPT for linking the SPL binary.
3676 CONFIG_SPL_MAX_FOOTPRINT
3677 Maximum size in memory allocated to the SPL, BSS included.
3678 When defined, the linker checks that the actual memory
3679 used by SPL from _start to __bss_end does not exceed it.
3680 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3681 must not be both defined at the same time.
3684 Maximum size of the SPL image (text, data, rodata, and
3685 linker lists sections), BSS excluded.
3686 When defined, the linker checks that the actual size does
3689 CONFIG_SPL_TEXT_BASE
3690 TEXT_BASE for linking the SPL binary.
3692 CONFIG_SPL_RELOC_TEXT_BASE
3693 Address to relocate to. If unspecified, this is equal to
3694 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3696 CONFIG_SPL_BSS_START_ADDR
3697 Link address for the BSS within the SPL binary.
3699 CONFIG_SPL_BSS_MAX_SIZE
3700 Maximum size in memory allocated to the SPL BSS.
3701 When defined, the linker checks that the actual memory used
3702 by SPL from __bss_start to __bss_end does not exceed it.
3703 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3704 must not be both defined at the same time.
3707 Adress of the start of the stack SPL will use
3709 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3710 When defined, SPL will panic() if the image it has
3711 loaded does not have a signature.
3712 Defining this is useful when code which loads images
3713 in SPL cannot guarantee that absolutely all read errors
3715 An example is the LPC32XX MLC NAND driver, which will
3716 consider that a completely unreadable NAND block is bad,
3717 and thus should be skipped silently.
3719 CONFIG_SPL_RELOC_STACK
3720 Adress of the start of the stack SPL will use after
3721 relocation. If unspecified, this is equal to
3724 CONFIG_SYS_SPL_MALLOC_START
3725 Starting address of the malloc pool used in SPL.
3727 CONFIG_SYS_SPL_MALLOC_SIZE
3728 The size of the malloc pool used in SPL.
3730 CONFIG_SPL_FRAMEWORK
3731 Enable the SPL framework under common/. This framework
3732 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3733 NAND loading of the Linux Kernel.
3736 Enable booting directly to an OS from SPL.
3737 See also: doc/README.falcon
3739 CONFIG_SPL_DISPLAY_PRINT
3740 For ARM, enable an optional function to print more information
3741 about the running system.
3743 CONFIG_SPL_INIT_MINIMAL
3744 Arch init code should be built for a very small image
3746 CONFIG_SPL_LIBCOMMON_SUPPORT
3747 Support for common/libcommon.o in SPL binary
3749 CONFIG_SPL_LIBDISK_SUPPORT
3750 Support for disk/libdisk.o in SPL binary
3752 CONFIG_SPL_I2C_SUPPORT
3753 Support for drivers/i2c/libi2c.o in SPL binary
3755 CONFIG_SPL_GPIO_SUPPORT
3756 Support for drivers/gpio/libgpio.o in SPL binary
3758 CONFIG_SPL_MMC_SUPPORT
3759 Support for drivers/mmc/libmmc.o in SPL binary
3761 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3762 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3763 Address and partition on the MMC to load U-Boot from
3764 when the MMC is being used in raw mode.
3766 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3767 Partition on the MMC to load U-Boot from when the MMC is being
3770 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3771 Sector to load kernel uImage from when MMC is being
3772 used in raw mode (for Falcon mode)
3774 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3775 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3776 Sector and number of sectors to load kernel argument
3777 parameters from when MMC is being used in raw mode
3780 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3781 Partition on the MMC to load U-Boot from when the MMC is being
3784 CONFIG_SPL_FAT_SUPPORT
3785 Support for fs/fat/libfat.o in SPL binary
3787 CONFIG_SPL_EXT_SUPPORT
3788 Support for EXT filesystem in SPL binary
3790 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3791 Filename to read to load U-Boot when reading from filesystem
3793 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3794 Filename to read to load kernel uImage when reading
3795 from filesystem (for Falcon mode)
3797 CONFIG_SPL_FS_LOAD_ARGS_NAME
3798 Filename to read to load kernel argument parameters
3799 when reading from filesystem (for Falcon mode)
3801 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3802 Set this for NAND SPL on PPC mpc83xx targets, so that
3803 start.S waits for the rest of the SPL to load before
3804 continuing (the hardware starts execution after just
3805 loading the first page rather than the full 4K).
3807 CONFIG_SPL_SKIP_RELOCATE
3808 Avoid SPL relocation
3810 CONFIG_SPL_NAND_BASE
3811 Include nand_base.c in the SPL. Requires
3812 CONFIG_SPL_NAND_DRIVERS.
3814 CONFIG_SPL_NAND_DRIVERS
3815 SPL uses normal NAND drivers, not minimal drivers.
3818 Include standard software ECC in the SPL
3820 CONFIG_SPL_NAND_SIMPLE
3821 Support for NAND boot using simple NAND drivers that
3822 expose the cmd_ctrl() interface.
3824 CONFIG_SPL_MTD_SUPPORT
3825 Support for the MTD subsystem within SPL. Useful for
3826 environment on NAND support within SPL.
3828 CONFIG_SPL_NAND_RAW_ONLY
3829 Support to boot only raw u-boot.bin images. Use this only
3830 if you need to save space.
3832 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3833 Set for the SPL on PPC mpc8xxx targets, support for
3834 drivers/ddr/fsl/libddr.o in SPL binary.
3836 CONFIG_SPL_COMMON_INIT_DDR
3837 Set for common ddr init with serial presence detect in
3840 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3841 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3842 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3843 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3844 CONFIG_SYS_NAND_ECCBYTES
3845 Defines the size and behavior of the NAND that SPL uses
3848 CONFIG_SPL_NAND_BOOT
3849 Add support NAND boot
3851 CONFIG_SYS_NAND_U_BOOT_OFFS
3852 Location in NAND to read U-Boot from
3854 CONFIG_SYS_NAND_U_BOOT_DST
3855 Location in memory to load U-Boot to
3857 CONFIG_SYS_NAND_U_BOOT_SIZE
3858 Size of image to load
3860 CONFIG_SYS_NAND_U_BOOT_START
3861 Entry point in loaded image to jump to
3863 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3864 Define this if you need to first read the OOB and then the
3865 data. This is used, for example, on davinci platforms.
3867 CONFIG_SPL_OMAP3_ID_NAND
3868 Support for an OMAP3-specific set of functions to return the
3869 ID and MFR of the first attached NAND chip, if present.
3871 CONFIG_SPL_SERIAL_SUPPORT
3872 Support for drivers/serial/libserial.o in SPL binary
3874 CONFIG_SPL_SPI_FLASH_SUPPORT
3875 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3877 CONFIG_SPL_SPI_SUPPORT
3878 Support for drivers/spi/libspi.o in SPL binary
3880 CONFIG_SPL_RAM_DEVICE
3881 Support for running image already present in ram, in SPL binary
3883 CONFIG_SPL_LIBGENERIC_SUPPORT
3884 Support for lib/libgeneric.o in SPL binary
3886 CONFIG_SPL_ENV_SUPPORT
3887 Support for the environment operating in SPL binary
3889 CONFIG_SPL_NET_SUPPORT
3890 Support for the net/libnet.o in SPL binary.
3891 It conflicts with SPL env from storage medium specified by
3892 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3895 Image offset to which the SPL should be padded before appending
3896 the SPL payload. By default, this is defined as
3897 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3898 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3899 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3902 Final target image containing SPL and payload. Some SPLs
3903 use an arch-specific makefile fragment instead, for
3904 example if more than one image needs to be produced.
3906 CONFIG_FIT_SPL_PRINT
3907 Printing information about a FIT image adds quite a bit of
3908 code to SPL. So this is normally disabled in SPL. Use this
3909 option to re-enable it. This will affect the output of the
3910 bootm command when booting a FIT image.
3914 Enable building of TPL globally.
3917 Image offset to which the TPL should be padded before appending
3918 the TPL payload. By default, this is defined as
3919 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3920 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3921 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3926 [so far only for SMDK2400 boards]
3928 - Modem support enable:
3929 CONFIG_MODEM_SUPPORT
3931 - RTS/CTS Flow control enable:
3934 - Modem debug support:
3935 CONFIG_MODEM_SUPPORT_DEBUG
3937 Enables debugging stuff (char screen[1024], dbg())
3938 for modem support. Useful only with BDI2000.
3940 - Interrupt support (PPC):
3942 There are common interrupt_init() and timer_interrupt()
3943 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3944 for CPU specific initialization. interrupt_init_cpu()
3945 should set decrementer_count to appropriate value. If
3946 CPU resets decrementer automatically after interrupt
3947 (ppc4xx) it should set decrementer_count to zero.
3948 timer_interrupt() calls timer_interrupt_cpu() for CPU
3949 specific handling. If board has watchdog / status_led
3950 / other_activity_monitor it works automatically from
3951 general timer_interrupt().
3955 In the target system modem support is enabled when a
3956 specific key (key combination) is pressed during
3957 power-on. Otherwise U-Boot will boot normally
3958 (autoboot). The key_pressed() function is called from
3959 board_init(). Currently key_pressed() is a dummy
3960 function, returning 1 and thus enabling modem
3963 If there are no modem init strings in the
3964 environment, U-Boot proceed to autoboot; the
3965 previous output (banner, info printfs) will be
3968 See also: doc/README.Modem
3970 Board initialization settings:
3971 ------------------------------
3973 During Initialization u-boot calls a number of board specific functions
3974 to allow the preparation of board specific prerequisites, e.g. pin setup
3975 before drivers are initialized. To enable these callbacks the
3976 following configuration macros have to be defined. Currently this is
3977 architecture specific, so please check arch/your_architecture/lib/board.c
3978 typically in board_init_f() and board_init_r().
3980 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3981 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3982 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3983 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3985 Configuration Settings:
3986 -----------------------
3988 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3989 Optionally it can be defined to support 64-bit memory commands.
3991 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3992 undefine this when you're short of memory.
3994 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3995 width of the commands listed in the 'help' command output.
3997 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3998 prompt for user input.
4000 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
4002 - CONFIG_SYS_PBSIZE: Buffer size for Console output
4004 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
4006 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
4007 the application (usually a Linux kernel) when it is
4010 - CONFIG_SYS_BAUDRATE_TABLE:
4011 List of legal baudrate settings for this board.
4013 - CONFIG_SYS_CONSOLE_INFO_QUIET
4014 Suppress display of console information at boot.
4016 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4017 If the board specific function
4018 extern int overwrite_console (void);
4019 returns 1, the stdin, stderr and stdout are switched to the
4020 serial port, else the settings in the environment are used.
4022 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4023 Enable the call to overwrite_console().
4025 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4026 Enable overwrite of previous console environment settings.
4028 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4029 Begin and End addresses of the area used by the
4032 - CONFIG_SYS_ALT_MEMTEST:
4033 Enable an alternate, more extensive memory test.
4035 - CONFIG_SYS_MEMTEST_SCRATCH:
4036 Scratch address used by the alternate memory test
4037 You only need to set this if address zero isn't writeable
4039 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4040 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4041 this specified memory area will get subtracted from the top
4042 (end) of RAM and won't get "touched" at all by U-Boot. By
4043 fixing up gd->ram_size the Linux kernel should gets passed
4044 the now "corrected" memory size and won't touch it either.
4045 This should work for arch/ppc and arch/powerpc. Only Linux
4046 board ports in arch/powerpc with bootwrapper support that
4047 recalculate the memory size from the SDRAM controller setup
4048 will have to get fixed in Linux additionally.
4050 This option can be used as a workaround for the 440EPx/GRx
4051 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4054 WARNING: Please make sure that this value is a multiple of
4055 the Linux page size (normally 4k). If this is not the case,
4056 then the end address of the Linux memory will be located at a
4057 non page size aligned address and this could cause major
4060 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4061 Enable temporary baudrate change while serial download
4063 - CONFIG_SYS_SDRAM_BASE:
4064 Physical start address of SDRAM. _Must_ be 0 here.
4066 - CONFIG_SYS_MBIO_BASE:
4067 Physical start address of Motherboard I/O (if using a
4070 - CONFIG_SYS_FLASH_BASE:
4071 Physical start address of Flash memory.
4073 - CONFIG_SYS_MONITOR_BASE:
4074 Physical start address of boot monitor code (set by
4075 make config files to be same as the text base address
4076 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4077 CONFIG_SYS_FLASH_BASE when booting from flash.
4079 - CONFIG_SYS_MONITOR_LEN:
4080 Size of memory reserved for monitor code, used to
4081 determine _at_compile_time_ (!) if the environment is
4082 embedded within the U-Boot image, or in a separate
4085 - CONFIG_SYS_MALLOC_LEN:
4086 Size of DRAM reserved for malloc() use.
4088 - CONFIG_SYS_MALLOC_F_LEN
4089 Size of the malloc() pool for use before relocation. If
4090 this is defined, then a very simple malloc() implementation
4091 will become available before relocation. The address is just
4092 below the global data, and the stack is moved down to make
4095 This feature allocates regions with increasing addresses
4096 within the region. calloc() is supported, but realloc()
4097 is not available. free() is supported but does nothing.
4098 The memory will be freed (or in fact just forgotten) when
4099 U-Boot relocates itself.
4101 Pre-relocation malloc() is only supported on ARM and sandbox
4102 at present but is fairly easy to enable for other archs.
4104 - CONFIG_SYS_MALLOC_SIMPLE
4105 Provides a simple and small malloc() and calloc() for those
4106 boards which do not use the full malloc in SPL (which is
4107 enabled with CONFIG_SYS_SPL_MALLOC_START).
4109 - CONFIG_SYS_NONCACHED_MEMORY:
4110 Size of non-cached memory area. This area of memory will be
4111 typically located right below the malloc() area and mapped
4112 uncached in the MMU. This is useful for drivers that would
4113 otherwise require a lot of explicit cache maintenance. For
4114 some drivers it's also impossible to properly maintain the
4115 cache. For example if the regions that need to be flushed
4116 are not a multiple of the cache-line size, *and* padding
4117 cannot be allocated between the regions to align them (i.e.
4118 if the HW requires a contiguous array of regions, and the
4119 size of each region is not cache-aligned), then a flush of
4120 one region may result in overwriting data that hardware has
4121 written to another region in the same cache-line. This can
4122 happen for example in network drivers where descriptors for
4123 buffers are typically smaller than the CPU cache-line (e.g.
4124 16 bytes vs. 32 or 64 bytes).
4126 Non-cached memory is only supported on 32-bit ARM at present.
4128 - CONFIG_SYS_BOOTM_LEN:
4129 Normally compressed uImages are limited to an
4130 uncompressed size of 8 MBytes. If this is not enough,
4131 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4132 to adjust this setting to your needs.
4134 - CONFIG_SYS_BOOTMAPSZ:
4135 Maximum size of memory mapped by the startup code of
4136 the Linux kernel; all data that must be processed by
4137 the Linux kernel (bd_info, boot arguments, FDT blob if
4138 used) must be put below this limit, unless "bootm_low"
4139 environment variable is defined and non-zero. In such case
4140 all data for the Linux kernel must be between "bootm_low"
4141 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4142 variable "bootm_mapsize" will override the value of
4143 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4144 then the value in "bootm_size" will be used instead.
4146 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4147 Enable initrd_high functionality. If defined then the
4148 initrd_high feature is enabled and the bootm ramdisk subcommand
4151 - CONFIG_SYS_BOOT_GET_CMDLINE:
4152 Enables allocating and saving kernel cmdline in space between
4153 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4155 - CONFIG_SYS_BOOT_GET_KBD:
4156 Enables allocating and saving a kernel copy of the bd_info in
4157 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4159 - CONFIG_SYS_MAX_FLASH_BANKS:
4160 Max number of Flash memory banks
4162 - CONFIG_SYS_MAX_FLASH_SECT:
4163 Max number of sectors on a Flash chip
4165 - CONFIG_SYS_FLASH_ERASE_TOUT:
4166 Timeout for Flash erase operations (in ms)
4168 - CONFIG_SYS_FLASH_WRITE_TOUT:
4169 Timeout for Flash write operations (in ms)
4171 - CONFIG_SYS_FLASH_LOCK_TOUT
4172 Timeout for Flash set sector lock bit operation (in ms)
4174 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4175 Timeout for Flash clear lock bits operation (in ms)
4177 - CONFIG_SYS_FLASH_PROTECTION
4178 If defined, hardware flash sectors protection is used
4179 instead of U-Boot software protection.
4181 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4183 Enable TFTP transfers directly to flash memory;
4184 without this option such a download has to be
4185 performed in two steps: (1) download to RAM, and (2)
4186 copy from RAM to flash.
4188 The two-step approach is usually more reliable, since
4189 you can check if the download worked before you erase
4190 the flash, but in some situations (when system RAM is
4191 too limited to allow for a temporary copy of the
4192 downloaded image) this option may be very useful.
4194 - CONFIG_SYS_FLASH_CFI:
4195 Define if the flash driver uses extra elements in the
4196 common flash structure for storing flash geometry.
4198 - CONFIG_FLASH_CFI_DRIVER
4199 This option also enables the building of the cfi_flash driver
4200 in the drivers directory
4202 - CONFIG_FLASH_CFI_MTD
4203 This option enables the building of the cfi_mtd driver
4204 in the drivers directory. The driver exports CFI flash
4207 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4208 Use buffered writes to flash.
4210 - CONFIG_FLASH_SPANSION_S29WS_N
4211 s29ws-n MirrorBit flash has non-standard addresses for buffered
4214 - CONFIG_SYS_FLASH_QUIET_TEST
4215 If this option is defined, the common CFI flash doesn't
4216 print it's warning upon not recognized FLASH banks. This
4217 is useful, if some of the configured banks are only
4218 optionally available.
4220 - CONFIG_FLASH_SHOW_PROGRESS
4221 If defined (must be an integer), print out countdown
4222 digits and dots. Recommended value: 45 (9..1) for 80
4223 column displays, 15 (3..1) for 40 column displays.
4225 - CONFIG_FLASH_VERIFY
4226 If defined, the content of the flash (destination) is compared
4227 against the source after the write operation. An error message
4228 will be printed when the contents are not identical.
4229 Please note that this option is useless in nearly all cases,
4230 since such flash programming errors usually are detected earlier
4231 while unprotecting/erasing/programming. Please only enable
4232 this option if you really know what you are doing.
4234 - CONFIG_SYS_RX_ETH_BUFFER:
4235 Defines the number of Ethernet receive buffers. On some
4236 Ethernet controllers it is recommended to set this value
4237 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4238 buffers can be full shortly after enabling the interface
4239 on high Ethernet traffic.
4240 Defaults to 4 if not defined.
4242 - CONFIG_ENV_MAX_ENTRIES
4244 Maximum number of entries in the hash table that is used
4245 internally to store the environment settings. The default
4246 setting is supposed to be generous and should work in most
4247 cases. This setting can be used to tune behaviour; see
4248 lib/hashtable.c for details.
4250 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4251 - CONFIG_ENV_FLAGS_LIST_STATIC
4252 Enable validation of the values given to environment variables when
4253 calling env set. Variables can be restricted to only decimal,
4254 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4255 the variables can also be restricted to IP address or MAC address.
4257 The format of the list is:
4258 type_attribute = [s|d|x|b|i|m]
4259 access_attribute = [a|r|o|c]
4260 attributes = type_attribute[access_attribute]
4261 entry = variable_name[:attributes]
4264 The type attributes are:
4265 s - String (default)
4268 b - Boolean ([1yYtT|0nNfF])
4272 The access attributes are:
4278 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4279 Define this to a list (string) to define the ".flags"
4280 environment variable in the default or embedded environment.
4282 - CONFIG_ENV_FLAGS_LIST_STATIC
4283 Define this to a list (string) to define validation that
4284 should be done if an entry is not found in the ".flags"
4285 environment variable. To override a setting in the static
4286 list, simply add an entry for the same variable name to the
4289 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4290 regular expression. This allows multiple variables to define the same
4291 flags without explicitly listing them for each variable.
4293 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4294 If defined, don't allow the -f switch to env set override variable
4297 - CONFIG_SYS_GENERIC_BOARD
4298 This selects the architecture-generic board system instead of the
4299 architecture-specific board files. It is intended to move boards
4300 to this new framework over time. Defining this will disable the
4301 arch/foo/lib/board.c file and use common/board_f.c and
4302 common/board_r.c instead. To use this option your architecture
4303 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4304 If you find problems enabling this option on your board please report
4305 the problem and send patches!
4307 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4308 This is set by OMAP boards for the max time that reset should
4309 be asserted. See doc/README.omap-reset-time for details on how
4310 the value can be calculated on a given board.
4313 If stdint.h is available with your toolchain you can define this
4314 option to enable it. You can provide option 'USE_STDINT=1' when
4315 building U-Boot to enable this.
4317 The following definitions that deal with the placement and management
4318 of environment data (variable area); in general, we support the
4319 following configurations:
4321 - CONFIG_BUILD_ENVCRC:
4323 Builds up envcrc with the target environment so that external utils
4324 may easily extract it and embed it in final U-Boot images.
4326 - CONFIG_ENV_IS_IN_FLASH:
4328 Define this if the environment is in flash memory.
4330 a) The environment occupies one whole flash sector, which is
4331 "embedded" in the text segment with the U-Boot code. This
4332 happens usually with "bottom boot sector" or "top boot
4333 sector" type flash chips, which have several smaller
4334 sectors at the start or the end. For instance, such a
4335 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4336 such a case you would place the environment in one of the
4337 4 kB sectors - with U-Boot code before and after it. With
4338 "top boot sector" type flash chips, you would put the
4339 environment in one of the last sectors, leaving a gap
4340 between U-Boot and the environment.
4342 - CONFIG_ENV_OFFSET:
4344 Offset of environment data (variable area) to the
4345 beginning of flash memory; for instance, with bottom boot
4346 type flash chips the second sector can be used: the offset
4347 for this sector is given here.
4349 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4353 This is just another way to specify the start address of
4354 the flash sector containing the environment (instead of
4357 - CONFIG_ENV_SECT_SIZE:
4359 Size of the sector containing the environment.
4362 b) Sometimes flash chips have few, equal sized, BIG sectors.
4363 In such a case you don't want to spend a whole sector for
4368 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4369 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4370 of this flash sector for the environment. This saves
4371 memory for the RAM copy of the environment.
4373 It may also save flash memory if you decide to use this
4374 when your environment is "embedded" within U-Boot code,
4375 since then the remainder of the flash sector could be used
4376 for U-Boot code. It should be pointed out that this is
4377 STRONGLY DISCOURAGED from a robustness point of view:
4378 updating the environment in flash makes it always
4379 necessary to erase the WHOLE sector. If something goes
4380 wrong before the contents has been restored from a copy in
4381 RAM, your target system will be dead.
4383 - CONFIG_ENV_ADDR_REDUND
4384 CONFIG_ENV_SIZE_REDUND
4386 These settings describe a second storage area used to hold
4387 a redundant copy of the environment data, so that there is
4388 a valid backup copy in case there is a power failure during
4389 a "saveenv" operation.
4391 BE CAREFUL! Any changes to the flash layout, and some changes to the
4392 source code will make it necessary to adapt <board>/u-boot.lds*
4396 - CONFIG_ENV_IS_IN_NVRAM:
4398 Define this if you have some non-volatile memory device
4399 (NVRAM, battery buffered SRAM) which you want to use for the
4405 These two #defines are used to determine the memory area you
4406 want to use for environment. It is assumed that this memory
4407 can just be read and written to, without any special
4410 BE CAREFUL! The first access to the environment happens quite early
4411 in U-Boot initialization (when we try to get the setting of for the
4412 console baudrate). You *MUST* have mapped your NVRAM area then, or
4415 Please note that even with NVRAM we still use a copy of the
4416 environment in RAM: we could work on NVRAM directly, but we want to
4417 keep settings there always unmodified except somebody uses "saveenv"
4418 to save the current settings.
4421 - CONFIG_ENV_IS_IN_EEPROM:
4423 Use this if you have an EEPROM or similar serial access
4424 device and a driver for it.
4426 - CONFIG_ENV_OFFSET:
4429 These two #defines specify the offset and size of the
4430 environment area within the total memory of your EEPROM.
4432 - CONFIG_SYS_I2C_EEPROM_ADDR:
4433 If defined, specified the chip address of the EEPROM device.
4434 The default address is zero.
4436 - CONFIG_SYS_I2C_EEPROM_BUS:
4437 If defined, specified the i2c bus of the EEPROM device.
4439 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4440 If defined, the number of bits used to address bytes in a
4441 single page in the EEPROM device. A 64 byte page, for example
4442 would require six bits.
4444 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4445 If defined, the number of milliseconds to delay between
4446 page writes. The default is zero milliseconds.
4448 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4449 The length in bytes of the EEPROM memory array address. Note
4450 that this is NOT the chip address length!
4452 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4453 EEPROM chips that implement "address overflow" are ones
4454 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4455 address and the extra bits end up in the "chip address" bit
4456 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4459 Note that we consider the length of the address field to
4460 still be one byte because the extra address bits are hidden
4461 in the chip address.
4463 - CONFIG_SYS_EEPROM_SIZE:
4464 The size in bytes of the EEPROM device.
4466 - CONFIG_ENV_EEPROM_IS_ON_I2C
4467 define this, if you have I2C and SPI activated, and your
4468 EEPROM, which holds the environment, is on the I2C bus.
4470 - CONFIG_I2C_ENV_EEPROM_BUS
4471 if you have an Environment on an EEPROM reached over
4472 I2C muxes, you can define here, how to reach this
4473 EEPROM. For example:
4475 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4477 EEPROM which holds the environment, is reached over
4478 a pca9547 i2c mux with address 0x70, channel 3.
4480 - CONFIG_ENV_IS_IN_DATAFLASH:
4482 Define this if you have a DataFlash memory device which you
4483 want to use for the environment.
4485 - CONFIG_ENV_OFFSET:
4489 These three #defines specify the offset and size of the
4490 environment area within the total memory of your DataFlash placed
4491 at the specified address.
4493 - CONFIG_ENV_IS_IN_SPI_FLASH:
4495 Define this if you have a SPI Flash memory device which you
4496 want to use for the environment.
4498 - CONFIG_ENV_OFFSET:
4501 These two #defines specify the offset and size of the
4502 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4503 aligned to an erase sector boundary.
4505 - CONFIG_ENV_SECT_SIZE:
4507 Define the SPI flash's sector size.
4509 - CONFIG_ENV_OFFSET_REDUND (optional):
4511 This setting describes a second storage area of CONFIG_ENV_SIZE
4512 size used to hold a redundant copy of the environment data, so
4513 that there is a valid backup copy in case there is a power failure
4514 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4515 aligned to an erase sector boundary.
4517 - CONFIG_ENV_SPI_BUS (optional):
4518 - CONFIG_ENV_SPI_CS (optional):
4520 Define the SPI bus and chip select. If not defined they will be 0.
4522 - CONFIG_ENV_SPI_MAX_HZ (optional):
4524 Define the SPI max work clock. If not defined then use 1MHz.
4526 - CONFIG_ENV_SPI_MODE (optional):
4528 Define the SPI work mode. If not defined then use SPI_MODE_3.
4530 - CONFIG_ENV_IS_IN_REMOTE:
4532 Define this if you have a remote memory space which you
4533 want to use for the local device's environment.
4538 These two #defines specify the address and size of the
4539 environment area within the remote memory space. The
4540 local device can get the environment from remote memory
4541 space by SRIO or PCIE links.
4543 BE CAREFUL! For some special cases, the local device can not use
4544 "saveenv" command. For example, the local device will get the
4545 environment stored in a remote NOR flash by SRIO or PCIE link,
4546 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4548 - CONFIG_ENV_IS_IN_NAND:
4550 Define this if you have a NAND device which you want to use
4551 for the environment.
4553 - CONFIG_ENV_OFFSET:
4556 These two #defines specify the offset and size of the environment
4557 area within the first NAND device. CONFIG_ENV_OFFSET must be
4558 aligned to an erase block boundary.
4560 - CONFIG_ENV_OFFSET_REDUND (optional):
4562 This setting describes a second storage area of CONFIG_ENV_SIZE
4563 size used to hold a redundant copy of the environment data, so
4564 that there is a valid backup copy in case there is a power failure
4565 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4566 aligned to an erase block boundary.
4568 - CONFIG_ENV_RANGE (optional):
4570 Specifies the length of the region in which the environment
4571 can be written. This should be a multiple of the NAND device's
4572 block size. Specifying a range with more erase blocks than
4573 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4574 the range to be avoided.
4576 - CONFIG_ENV_OFFSET_OOB (optional):
4578 Enables support for dynamically retrieving the offset of the
4579 environment from block zero's out-of-band data. The
4580 "nand env.oob" command can be used to record this offset.
4581 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4582 using CONFIG_ENV_OFFSET_OOB.
4584 - CONFIG_NAND_ENV_DST
4586 Defines address in RAM to which the nand_spl code should copy the
4587 environment. If redundant environment is used, it will be copied to
4588 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4590 - CONFIG_ENV_IS_IN_UBI:
4592 Define this if you have an UBI volume that you want to use for the
4593 environment. This has the benefit of wear-leveling the environment
4594 accesses, which is important on NAND.
4596 - CONFIG_ENV_UBI_PART:
4598 Define this to a string that is the mtd partition containing the UBI.
4600 - CONFIG_ENV_UBI_VOLUME:
4602 Define this to the name of the volume that you want to store the
4605 - CONFIG_ENV_UBI_VOLUME_REDUND:
4607 Define this to the name of another volume to store a second copy of
4608 the environment in. This will enable redundant environments in UBI.
4609 It is assumed that both volumes are in the same MTD partition.
4611 - CONFIG_UBI_SILENCE_MSG
4612 - CONFIG_UBIFS_SILENCE_MSG
4614 You will probably want to define these to avoid a really noisy system
4615 when storing the env in UBI.
4617 - CONFIG_ENV_IS_IN_FAT:
4618 Define this if you want to use the FAT file system for the environment.
4620 - FAT_ENV_INTERFACE:
4622 Define this to a string that is the name of the block device.
4624 - FAT_ENV_DEV_AND_PART:
4626 Define this to a string to specify the partition of the device. It can
4629 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4630 - "D:P": device D partition P. Error occurs if device D has no
4633 - "D" or "D:": device D partition 1 if device D has partition
4634 table, or the whole device D if has no partition
4636 - "D:auto": first partition in device D with bootable flag set.
4637 If none, first valid partition in device D. If no
4638 partition table then means device D.
4642 It's a string of the FAT file name. This file use to store the
4646 This should be defined. Otherwise it cannot save the environment file.
4648 - CONFIG_ENV_IS_IN_MMC:
4650 Define this if you have an MMC device which you want to use for the
4653 - CONFIG_SYS_MMC_ENV_DEV:
4655 Specifies which MMC device the environment is stored in.
4657 - CONFIG_SYS_MMC_ENV_PART (optional):
4659 Specifies which MMC partition the environment is stored in. If not
4660 set, defaults to partition 0, the user area. Common values might be
4661 1 (first MMC boot partition), 2 (second MMC boot partition).
4663 - CONFIG_ENV_OFFSET:
4666 These two #defines specify the offset and size of the environment
4667 area within the specified MMC device.
4669 If offset is positive (the usual case), it is treated as relative to
4670 the start of the MMC partition. If offset is negative, it is treated
4671 as relative to the end of the MMC partition. This can be useful if
4672 your board may be fitted with different MMC devices, which have
4673 different sizes for the MMC partitions, and you always want the
4674 environment placed at the very end of the partition, to leave the
4675 maximum possible space before it, to store other data.
4677 These two values are in units of bytes, but must be aligned to an
4678 MMC sector boundary.
4680 - CONFIG_ENV_OFFSET_REDUND (optional):
4682 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4683 hold a redundant copy of the environment data. This provides a
4684 valid backup copy in case the other copy is corrupted, e.g. due
4685 to a power failure during a "saveenv" operation.
4687 This value may also be positive or negative; this is handled in the
4688 same way as CONFIG_ENV_OFFSET.
4690 This value is also in units of bytes, but must also be aligned to
4691 an MMC sector boundary.
4693 - CONFIG_ENV_SIZE_REDUND (optional):
4695 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4696 set. If this value is set, it must be set to the same value as
4699 - CONFIG_SYS_SPI_INIT_OFFSET
4701 Defines offset to the initial SPI buffer area in DPRAM. The
4702 area is used at an early stage (ROM part) if the environment
4703 is configured to reside in the SPI EEPROM: We need a 520 byte
4704 scratch DPRAM area. It is used between the two initialization
4705 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4706 to be a good choice since it makes it far enough from the
4707 start of the data area as well as from the stack pointer.
4709 Please note that the environment is read-only until the monitor
4710 has been relocated to RAM and a RAM copy of the environment has been
4711 created; also, when using EEPROM you will have to use getenv_f()
4712 until then to read environment variables.
4714 The environment is protected by a CRC32 checksum. Before the monitor
4715 is relocated into RAM, as a result of a bad CRC you will be working
4716 with the compiled-in default environment - *silently*!!! [This is
4717 necessary, because the first environment variable we need is the
4718 "baudrate" setting for the console - if we have a bad CRC, we don't
4719 have any device yet where we could complain.]
4721 Note: once the monitor has been relocated, then it will complain if
4722 the default environment is used; a new CRC is computed as soon as you
4723 use the "saveenv" command to store a valid environment.
4725 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4726 Echo the inverted Ethernet link state to the fault LED.
4728 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4729 also needs to be defined.
4731 - CONFIG_SYS_FAULT_MII_ADDR:
4732 MII address of the PHY to check for the Ethernet link state.
4734 - CONFIG_NS16550_MIN_FUNCTIONS:
4735 Define this if you desire to only have use of the NS16550_init
4736 and NS16550_putc functions for the serial driver located at
4737 drivers/serial/ns16550.c. This option is useful for saving
4738 space for already greatly restricted images, including but not
4739 limited to NAND_SPL configurations.
4741 - CONFIG_DISPLAY_BOARDINFO
4742 Display information about the board that U-Boot is running on
4743 when U-Boot starts up. The board function checkboard() is called
4746 - CONFIG_DISPLAY_BOARDINFO_LATE
4747 Similar to the previous option, but display this information
4748 later, once stdio is running and output goes to the LCD, if
4751 - CONFIG_BOARD_SIZE_LIMIT:
4752 Maximum size of the U-Boot image. When defined, the
4753 build system checks that the actual size does not
4756 Low Level (hardware related) configuration options:
4757 ---------------------------------------------------
4759 - CONFIG_SYS_CACHELINE_SIZE:
4760 Cache Line Size of the CPU.
4762 - CONFIG_SYS_DEFAULT_IMMR:
4763 Default address of the IMMR after system reset.
4765 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4766 and RPXsuper) to be able to adjust the position of
4767 the IMMR register after a reset.
4769 - CONFIG_SYS_CCSRBAR_DEFAULT:
4770 Default (power-on reset) physical address of CCSR on Freescale
4773 - CONFIG_SYS_CCSRBAR:
4774 Virtual address of CCSR. On a 32-bit build, this is typically
4775 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4777 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4778 for cross-platform code that uses that macro instead.
4780 - CONFIG_SYS_CCSRBAR_PHYS:
4781 Physical address of CCSR. CCSR can be relocated to a new
4782 physical address, if desired. In this case, this macro should
4783 be set to that address. Otherwise, it should be set to the
4784 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4785 is typically relocated on 36-bit builds. It is recommended
4786 that this macro be defined via the _HIGH and _LOW macros:
4788 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4789 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4791 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4792 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4793 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4794 used in assembly code, so it must not contain typecasts or
4795 integer size suffixes (e.g. "ULL").
4797 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4798 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4799 used in assembly code, so it must not contain typecasts or
4800 integer size suffixes (e.g. "ULL").
4802 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4803 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4804 forced to a value that ensures that CCSR is not relocated.
4806 - Floppy Disk Support:
4807 CONFIG_SYS_FDC_DRIVE_NUMBER
4809 the default drive number (default value 0)
4811 CONFIG_SYS_ISA_IO_STRIDE
4813 defines the spacing between FDC chipset registers
4816 CONFIG_SYS_ISA_IO_OFFSET
4818 defines the offset of register from address. It
4819 depends on which part of the data bus is connected to
4820 the FDC chipset. (default value 0)
4822 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4823 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4826 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4827 fdc_hw_init() is called at the beginning of the FDC
4828 setup. fdc_hw_init() must be provided by the board
4829 source code. It is used to make hardware-dependent
4833 Most IDE controllers were designed to be connected with PCI
4834 interface. Only few of them were designed for AHB interface.
4835 When software is doing ATA command and data transfer to
4836 IDE devices through IDE-AHB controller, some additional
4837 registers accessing to these kind of IDE-AHB controller
4840 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4841 DO NOT CHANGE unless you know exactly what you're
4842 doing! (11-4) [MPC8xx/82xx systems only]
4844 - CONFIG_SYS_INIT_RAM_ADDR:
4846 Start address of memory area that can be used for
4847 initial data and stack; please note that this must be
4848 writable memory that is working WITHOUT special
4849 initialization, i. e. you CANNOT use normal RAM which
4850 will become available only after programming the
4851 memory controller and running certain initialization
4854 U-Boot uses the following memory types:
4855 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4856 - MPC824X: data cache
4857 - PPC4xx: data cache
4859 - CONFIG_SYS_GBL_DATA_OFFSET:
4861 Offset of the initial data structure in the memory
4862 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4863 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4864 data is located at the end of the available space
4865 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4866 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4867 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4868 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4871 On the MPC824X (or other systems that use the data
4872 cache for initial memory) the address chosen for
4873 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4874 point to an otherwise UNUSED address space between
4875 the top of RAM and the start of the PCI space.
4877 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4879 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4881 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4883 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4885 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4887 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4889 - CONFIG_SYS_OR_TIMING_SDRAM:
4892 - CONFIG_SYS_MAMR_PTA:
4893 periodic timer for refresh
4895 - CONFIG_SYS_DER: Debug Event Register (37-47)
4897 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4898 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4899 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4900 CONFIG_SYS_BR1_PRELIM:
4901 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4903 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4904 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4905 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4906 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4908 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4909 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4910 Machine Mode Register and Memory Periodic Timer
4911 Prescaler definitions (SDRAM timing)
4913 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4914 enable I2C microcode relocation patch (MPC8xx);
4915 define relocation offset in DPRAM [DSP2]
4917 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4918 enable SMC microcode relocation patch (MPC8xx);
4919 define relocation offset in DPRAM [SMC1]
4921 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4922 enable SPI microcode relocation patch (MPC8xx);
4923 define relocation offset in DPRAM [SCC4]
4925 - CONFIG_SYS_USE_OSCCLK:
4926 Use OSCM clock mode on MBX8xx board. Be careful,
4927 wrong setting might damage your board. Read
4928 doc/README.MBX before setting this variable!
4930 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4931 Offset of the bootmode word in DPRAM used by post
4932 (Power On Self Tests). This definition overrides
4933 #define'd default value in commproc.h resp.
4936 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4937 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4938 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4939 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4940 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4941 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4942 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4943 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4944 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4946 - CONFIG_PCI_DISABLE_PCIE:
4947 Disable PCI-Express on systems where it is supported but not
4950 - CONFIG_PCI_ENUM_ONLY
4951 Only scan through and get the devices on the buses.
4952 Don't do any setup work, presumably because someone or
4953 something has already done it, and we don't need to do it
4954 a second time. Useful for platforms that are pre-booted
4955 by coreboot or similar.
4957 - CONFIG_PCI_INDIRECT_BRIDGE:
4958 Enable support for indirect PCI bridges.
4961 Chip has SRIO or not
4964 Board has SRIO 1 port available
4967 Board has SRIO 2 port available
4969 - CONFIG_SRIO_PCIE_BOOT_MASTER
4970 Board can support master function for Boot from SRIO and PCIE
4972 - CONFIG_SYS_SRIOn_MEM_VIRT:
4973 Virtual Address of SRIO port 'n' memory region
4975 - CONFIG_SYS_SRIOn_MEM_PHYS:
4976 Physical Address of SRIO port 'n' memory region
4978 - CONFIG_SYS_SRIOn_MEM_SIZE:
4979 Size of SRIO port 'n' memory region
4981 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4982 Defined to tell the NAND controller that the NAND chip is using
4984 Not all NAND drivers use this symbol.
4985 Example of drivers that use it:
4986 - drivers/mtd/nand/ndfc.c
4987 - drivers/mtd/nand/mxc_nand.c
4989 - CONFIG_SYS_NDFC_EBC0_CFG
4990 Sets the EBC0_CFG register for the NDFC. If not defined
4991 a default value will be used.
4994 Get DDR timing information from an I2C EEPROM. Common
4995 with pluggable memory modules such as SODIMMs
4998 I2C address of the SPD EEPROM
5000 - CONFIG_SYS_SPD_BUS_NUM
5001 If SPD EEPROM is on an I2C bus other than the first
5002 one, specify here. Note that the value must resolve
5003 to something your driver can deal with.
5005 - CONFIG_SYS_DDR_RAW_TIMING
5006 Get DDR timing information from other than SPD. Common with
5007 soldered DDR chips onboard without SPD. DDR raw timing
5008 parameters are extracted from datasheet and hard-coded into
5009 header files or board specific files.
5011 - CONFIG_FSL_DDR_INTERACTIVE
5012 Enable interactive DDR debugging. See doc/README.fsl-ddr.
5014 - CONFIG_FSL_DDR_SYNC_REFRESH
5015 Enable sync of refresh for multiple controllers.
5017 - CONFIG_FSL_DDR_BIST
5018 Enable built-in memory test for Freescale DDR controllers.
5020 - CONFIG_SYS_83XX_DDR_USES_CS0
5021 Only for 83xx systems. If specified, then DDR should
5022 be configured using CS0 and CS1 instead of CS2 and CS3.
5024 - CONFIG_ETHER_ON_FEC[12]
5025 Define to enable FEC[12] on a 8xx series processor.
5027 - CONFIG_FEC[12]_PHY
5028 Define to the hardcoded PHY address which corresponds
5029 to the given FEC; i. e.
5030 #define CONFIG_FEC1_PHY 4
5031 means that the PHY with address 4 is connected to FEC1
5033 When set to -1, means to probe for first available.
5035 - CONFIG_FEC[12]_PHY_NORXERR
5036 The PHY does not have a RXERR line (RMII only).
5037 (so program the FEC to ignore it).
5040 Enable RMII mode for all FECs.
5041 Note that this is a global option, we can't
5042 have one FEC in standard MII mode and another in RMII mode.
5044 - CONFIG_CRC32_VERIFY
5045 Add a verify option to the crc32 command.
5048 => crc32 -v <address> <count> <crc32>
5050 Where address/count indicate a memory area
5051 and crc32 is the correct crc32 which the
5055 Add the "loopw" memory command. This only takes effect if
5056 the memory commands are activated globally (CONFIG_CMD_MEM).
5059 Add the "mdc" and "mwc" memory commands. These are cyclic
5064 This command will print 4 bytes (10,11,12,13) each 500 ms.
5066 => mwc.l 100 12345678 10
5067 This command will write 12345678 to address 100 all 10 ms.
5069 This only takes effect if the memory commands are activated
5070 globally (CONFIG_CMD_MEM).
5072 - CONFIG_SKIP_LOWLEVEL_INIT
5073 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5074 low level initializations (like setting up the memory
5075 controller) are omitted and/or U-Boot does not
5076 relocate itself into RAM.
5078 Normally this variable MUST NOT be defined. The only
5079 exception is when U-Boot is loaded (to RAM) by some
5080 other boot loader or by a debugger which performs
5081 these initializations itself.
5084 Modifies the behaviour of start.S when compiling a loader
5085 that is executed before the actual U-Boot. E.g. when
5086 compiling a NAND SPL.
5089 Modifies the behaviour of start.S when compiling a loader
5090 that is executed after the SPL and before the actual U-Boot.
5091 It is loaded by the SPL.
5093 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5094 Only for 85xx systems. If this variable is specified, the section
5095 .resetvec is not kept and the section .bootpg is placed in the
5096 previous 4k of the .text section.
5098 - CONFIG_ARCH_MAP_SYSMEM
5099 Generally U-Boot (and in particular the md command) uses
5100 effective address. It is therefore not necessary to regard
5101 U-Boot address as virtual addresses that need to be translated
5102 to physical addresses. However, sandbox requires this, since
5103 it maintains its own little RAM buffer which contains all
5104 addressable memory. This option causes some memory accesses
5105 to be mapped through map_sysmem() / unmap_sysmem().
5107 - CONFIG_USE_ARCH_MEMCPY
5108 CONFIG_USE_ARCH_MEMSET
5109 If these options are used a optimized version of memcpy/memset will
5110 be used if available. These functions may be faster under some
5111 conditions but may increase the binary size.
5113 - CONFIG_X86_RESET_VECTOR
5114 If defined, the x86 reset vector code is included. This is not
5115 needed when U-Boot is running from Coreboot.
5118 Defines the MPU clock speed (in MHz).
5120 NOTE : currently only supported on AM335x platforms.
5122 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5123 Enables the RTC32K OSC on AM33xx based plattforms
5125 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5126 Option to disable subpage write in NAND driver
5127 driver that uses this:
5128 drivers/mtd/nand/davinci_nand.c
5130 Freescale QE/FMAN Firmware Support:
5131 -----------------------------------
5133 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5134 loading of "firmware", which is encoded in the QE firmware binary format.
5135 This firmware often needs to be loaded during U-Boot booting, so macros
5136 are used to identify the storage device (NOR flash, SPI, etc) and the address
5139 - CONFIG_SYS_FMAN_FW_ADDR
5140 The address in the storage device where the FMAN microcode is located. The
5141 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5144 - CONFIG_SYS_QE_FW_ADDR
5145 The address in the storage device where the QE microcode is located. The
5146 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5149 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5150 The maximum possible size of the firmware. The firmware binary format
5151 has a field that specifies the actual size of the firmware, but it
5152 might not be possible to read any part of the firmware unless some
5153 local storage is allocated to hold the entire firmware first.
5155 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5156 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5157 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5158 virtual address in NOR flash.
5160 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5161 Specifies that QE/FMAN firmware is located in NAND flash.
5162 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5164 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5165 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5166 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5168 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5169 Specifies that QE/FMAN firmware is located on the primary SPI
5170 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5172 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5173 Specifies that QE/FMAN firmware is located in the remote (master)
5174 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5175 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5176 window->master inbound window->master LAW->the ucode address in
5177 master's memory space.
5179 Freescale Layerscape Management Complex Firmware Support:
5180 ---------------------------------------------------------
5181 The Freescale Layerscape Management Complex (MC) supports the loading of
5183 This firmware often needs to be loaded during U-Boot booting, so macros
5184 are used to identify the storage device (NOR flash, SPI, etc) and the address
5187 - CONFIG_FSL_MC_ENET
5188 Enable the MC driver for Layerscape SoCs.
5190 - CONFIG_SYS_LS_MC_FW_ADDR
5191 The address in the storage device where the firmware is located. The
5192 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5195 - CONFIG_SYS_LS_MC_FW_LENGTH
5196 The maximum possible size of the firmware. The firmware binary format
5197 has a field that specifies the actual size of the firmware, but it
5198 might not be possible to read any part of the firmware unless some
5199 local storage is allocated to hold the entire firmware first.
5201 - CONFIG_SYS_LS_MC_FW_IN_NOR
5202 Specifies that MC firmware is located in NOR flash, mapped as
5203 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5204 virtual address in NOR flash.
5206 Building the Software:
5207 ======================
5209 Building U-Boot has been tested in several native build environments
5210 and in many different cross environments. Of course we cannot support
5211 all possibly existing versions of cross development tools in all
5212 (potentially obsolete) versions. In case of tool chain problems we
5213 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5214 which is extensively used to build and test U-Boot.
5216 If you are not using a native environment, it is assumed that you
5217 have GNU cross compiling tools available in your path. In this case,
5218 you must set the environment variable CROSS_COMPILE in your shell.
5219 Note that no changes to the Makefile or any other source files are
5220 necessary. For example using the ELDK on a 4xx CPU, please enter:
5222 $ CROSS_COMPILE=ppc_4xx-
5223 $ export CROSS_COMPILE
5225 Note: If you wish to generate Windows versions of the utilities in
5226 the tools directory you can use the MinGW toolchain
5227 (http://www.mingw.org). Set your HOST tools to the MinGW
5228 toolchain and execute 'make tools'. For example:
5230 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5232 Binaries such as tools/mkimage.exe will be created which can
5233 be executed on computers running Windows.
5235 U-Boot is intended to be simple to build. After installing the
5236 sources you must configure U-Boot for one specific board type. This
5241 where "NAME_defconfig" is the name of one of the existing configu-
5242 rations; see boards.cfg for supported names.
5244 Note: for some board special configuration names may exist; check if
5245 additional information is available from the board vendor; for
5246 instance, the TQM823L systems are available without (standard)
5247 or with LCD support. You can select such additional "features"
5248 when choosing the configuration, i. e.
5250 make TQM823L_defconfig
5251 - will configure for a plain TQM823L, i. e. no LCD support
5253 make TQM823L_LCD_defconfig
5254 - will configure for a TQM823L with U-Boot console on LCD
5259 Finally, type "make all", and you should get some working U-Boot
5260 images ready for download to / installation on your system:
5262 - "u-boot.bin" is a raw binary image
5263 - "u-boot" is an image in ELF binary format
5264 - "u-boot.srec" is in Motorola S-Record format
5266 By default the build is performed locally and the objects are saved
5267 in the source directory. One of the two methods can be used to change
5268 this behavior and build U-Boot to some external directory:
5270 1. Add O= to the make command line invocations:
5272 make O=/tmp/build distclean
5273 make O=/tmp/build NAME_defconfig
5274 make O=/tmp/build all
5276 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5278 export KBUILD_OUTPUT=/tmp/build
5283 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5287 Please be aware that the Makefiles assume you are using GNU make, so
5288 for instance on NetBSD you might need to use "gmake" instead of
5292 If the system board that you have is not listed, then you will need
5293 to port U-Boot to your hardware platform. To do this, follow these
5296 1. Add a new configuration option for your board to the toplevel
5297 "boards.cfg" file, using the existing entries as examples.
5298 Follow the instructions there to keep the boards in order.
5299 2. Create a new directory to hold your board specific code. Add any
5300 files you need. In your board directory, you will need at least
5301 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5302 3. Create a new configuration file "include/configs/<board>.h" for
5304 3. If you're porting U-Boot to a new CPU, then also create a new
5305 directory to hold your CPU specific code. Add any files you need.
5306 4. Run "make <board>_defconfig" with your new name.
5307 5. Type "make", and you should get a working "u-boot.srec" file
5308 to be installed on your target system.
5309 6. Debug and solve any problems that might arise.
5310 [Of course, this last step is much harder than it sounds.]
5313 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5314 ==============================================================
5316 If you have modified U-Boot sources (for instance added a new board
5317 or support for new devices, a new CPU, etc.) you are expected to
5318 provide feedback to the other developers. The feedback normally takes
5319 the form of a "patch", i. e. a context diff against a certain (latest
5320 official or latest in the git repository) version of U-Boot sources.
5322 But before you submit such a patch, please verify that your modifi-
5323 cation did not break existing code. At least make sure that *ALL* of
5324 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5325 just run the "MAKEALL" script, which will configure and build U-Boot
5326 for ALL supported system. Be warned, this will take a while. You can
5327 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5328 environment variable to the script, i. e. to use the ELDK cross tools
5331 CROSS_COMPILE=ppc_8xx- MAKEALL
5333 or to build on a native PowerPC system you can type
5335 CROSS_COMPILE=' ' MAKEALL
5337 When using the MAKEALL script, the default behaviour is to build
5338 U-Boot in the source directory. This location can be changed by
5339 setting the BUILD_DIR environment variable. Also, for each target
5340 built, the MAKEALL script saves two log files (<target>.ERR and
5341 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5342 location can be changed by setting the MAKEALL_LOGDIR environment
5343 variable. For example:
5345 export BUILD_DIR=/tmp/build
5346 export MAKEALL_LOGDIR=/tmp/log
5347 CROSS_COMPILE=ppc_8xx- MAKEALL
5349 With the above settings build objects are saved in the /tmp/build,
5350 log files are saved in the /tmp/log and the source tree remains clean
5351 during the whole build process.
5354 See also "U-Boot Porting Guide" below.
5357 Monitor Commands - Overview:
5358 ============================
5360 go - start application at address 'addr'
5361 run - run commands in an environment variable
5362 bootm - boot application image from memory
5363 bootp - boot image via network using BootP/TFTP protocol
5364 bootz - boot zImage from memory
5365 tftpboot- boot image via network using TFTP protocol
5366 and env variables "ipaddr" and "serverip"
5367 (and eventually "gatewayip")
5368 tftpput - upload a file via network using TFTP protocol
5369 rarpboot- boot image via network using RARP/TFTP protocol
5370 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5371 loads - load S-Record file over serial line
5372 loadb - load binary file over serial line (kermit mode)
5374 mm - memory modify (auto-incrementing)
5375 nm - memory modify (constant address)
5376 mw - memory write (fill)
5378 cmp - memory compare
5379 crc32 - checksum calculation
5380 i2c - I2C sub-system
5381 sspi - SPI utility commands
5382 base - print or set address offset
5383 printenv- print environment variables
5384 setenv - set environment variables
5385 saveenv - save environment variables to persistent storage
5386 protect - enable or disable FLASH write protection
5387 erase - erase FLASH memory
5388 flinfo - print FLASH memory information
5389 nand - NAND memory operations (see doc/README.nand)
5390 bdinfo - print Board Info structure
5391 iminfo - print header information for application image
5392 coninfo - print console devices and informations
5393 ide - IDE sub-system
5394 loop - infinite loop on address range
5395 loopw - infinite write loop on address range
5396 mtest - simple RAM test
5397 icache - enable or disable instruction cache
5398 dcache - enable or disable data cache
5399 reset - Perform RESET of the CPU
5400 echo - echo args to console
5401 version - print monitor version
5402 help - print online help
5403 ? - alias for 'help'
5406 Monitor Commands - Detailed Description:
5407 ========================================
5411 For now: just type "help <command>".
5414 Environment Variables:
5415 ======================
5417 U-Boot supports user configuration using Environment Variables which
5418 can be made persistent by saving to Flash memory.
5420 Environment Variables are set using "setenv", printed using
5421 "printenv", and saved to Flash using "saveenv". Using "setenv"
5422 without a value can be used to delete a variable from the
5423 environment. As long as you don't save the environment you are
5424 working with an in-memory copy. In case the Flash area containing the
5425 environment is erased by accident, a default environment is provided.
5427 Some configuration options can be set using Environment Variables.
5429 List of environment variables (most likely not complete):
5431 baudrate - see CONFIG_BAUDRATE
5433 bootdelay - see CONFIG_BOOTDELAY
5435 bootcmd - see CONFIG_BOOTCOMMAND
5437 bootargs - Boot arguments when booting an RTOS image
5439 bootfile - Name of the image to load with TFTP
5441 bootm_low - Memory range available for image processing in the bootm
5442 command can be restricted. This variable is given as
5443 a hexadecimal number and defines lowest address allowed
5444 for use by the bootm command. See also "bootm_size"
5445 environment variable. Address defined by "bootm_low" is
5446 also the base of the initial memory mapping for the Linux
5447 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5450 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5451 This variable is given as a hexadecimal number and it
5452 defines the size of the memory region starting at base
5453 address bootm_low that is accessible by the Linux kernel
5454 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5455 as the default value if it is defined, and bootm_size is
5458 bootm_size - Memory range available for image processing in the bootm
5459 command can be restricted. This variable is given as
5460 a hexadecimal number and defines the size of the region
5461 allowed for use by the bootm command. See also "bootm_low"
5462 environment variable.
5464 updatefile - Location of the software update file on a TFTP server, used
5465 by the automatic software update feature. Please refer to
5466 documentation in doc/README.update for more details.
5468 autoload - if set to "no" (any string beginning with 'n'),
5469 "bootp" will just load perform a lookup of the
5470 configuration from the BOOTP server, but not try to
5471 load any image using TFTP
5473 autostart - if set to "yes", an image loaded using the "bootp",
5474 "rarpboot", "tftpboot" or "diskboot" commands will
5475 be automatically started (by internally calling
5478 If set to "no", a standalone image passed to the
5479 "bootm" command will be copied to the load address
5480 (and eventually uncompressed), but NOT be started.
5481 This can be used to load and uncompress arbitrary
5484 fdt_high - if set this restricts the maximum address that the
5485 flattened device tree will be copied into upon boot.
5486 For example, if you have a system with 1 GB memory
5487 at physical address 0x10000000, while Linux kernel
5488 only recognizes the first 704 MB as low memory, you
5489 may need to set fdt_high as 0x3C000000 to have the
5490 device tree blob be copied to the maximum address
5491 of the 704 MB low memory, so that Linux kernel can
5492 access it during the boot procedure.
5494 If this is set to the special value 0xFFFFFFFF then
5495 the fdt will not be copied at all on boot. For this
5496 to work it must reside in writable memory, have
5497 sufficient padding on the end of it for u-boot to
5498 add the information it needs into it, and the memory
5499 must be accessible by the kernel.
5501 fdtcontroladdr- if set this is the address of the control flattened
5502 device tree used by U-Boot when CONFIG_OF_CONTROL is
5505 i2cfast - (PPC405GP|PPC405EP only)
5506 if set to 'y' configures Linux I2C driver for fast
5507 mode (400kHZ). This environment variable is used in
5508 initialization code. So, for changes to be effective
5509 it must be saved and board must be reset.
5511 initrd_high - restrict positioning of initrd images:
5512 If this variable is not set, initrd images will be
5513 copied to the highest possible address in RAM; this
5514 is usually what you want since it allows for
5515 maximum initrd size. If for some reason you want to
5516 make sure that the initrd image is loaded below the
5517 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5518 variable to a value of "no" or "off" or "0".
5519 Alternatively, you can set it to a maximum upper
5520 address to use (U-Boot will still check that it
5521 does not overwrite the U-Boot stack and data).
5523 For instance, when you have a system with 16 MB
5524 RAM, and want to reserve 4 MB from use by Linux,
5525 you can do this by adding "mem=12M" to the value of
5526 the "bootargs" variable. However, now you must make
5527 sure that the initrd image is placed in the first
5528 12 MB as well - this can be done with
5530 setenv initrd_high 00c00000
5532 If you set initrd_high to 0xFFFFFFFF, this is an
5533 indication to U-Boot that all addresses are legal
5534 for the Linux kernel, including addresses in flash
5535 memory. In this case U-Boot will NOT COPY the
5536 ramdisk at all. This may be useful to reduce the
5537 boot time on your system, but requires that this
5538 feature is supported by your Linux kernel.
5540 ipaddr - IP address; needed for tftpboot command
5542 loadaddr - Default load address for commands like "bootp",
5543 "rarpboot", "tftpboot", "loadb" or "diskboot"
5545 loads_echo - see CONFIG_LOADS_ECHO
5547 serverip - TFTP server IP address; needed for tftpboot command
5549 bootretry - see CONFIG_BOOT_RETRY_TIME
5551 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5553 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5555 ethprime - controls which interface is used first.
5557 ethact - controls which interface is currently active.
5558 For example you can do the following
5560 => setenv ethact FEC
5561 => ping 192.168.0.1 # traffic sent on FEC
5562 => setenv ethact SCC
5563 => ping 10.0.0.1 # traffic sent on SCC
5565 ethrotate - When set to "no" U-Boot does not go through all
5566 available network interfaces.
5567 It just stays at the currently selected interface.
5569 netretry - When set to "no" each network operation will
5570 either succeed or fail without retrying.
5571 When set to "once" the network operation will
5572 fail when all the available network interfaces
5573 are tried once without success.
5574 Useful on scripts which control the retry operation
5577 npe_ucode - set load address for the NPE microcode
5579 silent_linux - If set then Linux will be told to boot silently, by
5580 changing the console to be empty. If "yes" it will be
5581 made silent. If "no" it will not be made silent. If
5582 unset, then it will be made silent if the U-Boot console
5585 tftpsrcport - If this is set, the value is used for TFTP's
5588 tftpdstport - If this is set, the value is used for TFTP's UDP
5589 destination port instead of the Well Know Port 69.
5591 tftpblocksize - Block size to use for TFTP transfers; if not set,
5592 we use the TFTP server's default block size
5594 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5595 seconds, minimum value is 1000 = 1 second). Defines
5596 when a packet is considered to be lost so it has to
5597 be retransmitted. The default is 5000 = 5 seconds.
5598 Lowering this value may make downloads succeed
5599 faster in networks with high packet loss rates or
5600 with unreliable TFTP servers.
5602 vlan - When set to a value < 4095 the traffic over
5603 Ethernet is encapsulated/received over 802.1q
5606 The following image location variables contain the location of images
5607 used in booting. The "Image" column gives the role of the image and is
5608 not an environment variable name. The other columns are environment
5609 variable names. "File Name" gives the name of the file on a TFTP
5610 server, "RAM Address" gives the location in RAM the image will be
5611 loaded to, and "Flash Location" gives the image's address in NOR
5612 flash or offset in NAND flash.
5614 *Note* - these variables don't have to be defined for all boards, some
5615 boards currently use other variables for these purposes, and some
5616 boards use these variables for other purposes.
5618 Image File Name RAM Address Flash Location
5619 ----- --------- ----------- --------------
5620 u-boot u-boot u-boot_addr_r u-boot_addr
5621 Linux kernel bootfile kernel_addr_r kernel_addr
5622 device tree blob fdtfile fdt_addr_r fdt_addr
5623 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5625 The following environment variables may be used and automatically
5626 updated by the network boot commands ("bootp" and "rarpboot"),
5627 depending the information provided by your boot server:
5629 bootfile - see above
5630 dnsip - IP address of your Domain Name Server
5631 dnsip2 - IP address of your secondary Domain Name Server
5632 gatewayip - IP address of the Gateway (Router) to use
5633 hostname - Target hostname
5635 netmask - Subnet Mask
5636 rootpath - Pathname of the root filesystem on the NFS server
5637 serverip - see above
5640 There are two special Environment Variables:
5642 serial# - contains hardware identification information such
5643 as type string and/or serial number
5644 ethaddr - Ethernet address
5646 These variables can be set only once (usually during manufacturing of
5647 the board). U-Boot refuses to delete or overwrite these variables
5648 once they have been set once.
5651 Further special Environment Variables:
5653 ver - Contains the U-Boot version string as printed
5654 with the "version" command. This variable is
5655 readonly (see CONFIG_VERSION_VARIABLE).
5658 Please note that changes to some configuration parameters may take
5659 only effect after the next boot (yes, that's just like Windoze :-).
5662 Callback functions for environment variables:
5663 ---------------------------------------------
5665 For some environment variables, the behavior of u-boot needs to change
5666 when their values are changed. This functionality allows functions to
5667 be associated with arbitrary variables. On creation, overwrite, or
5668 deletion, the callback will provide the opportunity for some side
5669 effect to happen or for the change to be rejected.
5671 The callbacks are named and associated with a function using the
5672 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5674 These callbacks are associated with variables in one of two ways. The
5675 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5676 in the board configuration to a string that defines a list of
5677 associations. The list must be in the following format:
5679 entry = variable_name[:callback_name]
5682 If the callback name is not specified, then the callback is deleted.
5683 Spaces are also allowed anywhere in the list.
5685 Callbacks can also be associated by defining the ".callbacks" variable
5686 with the same list format above. Any association in ".callbacks" will
5687 override any association in the static list. You can define
5688 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5689 ".callbacks" environment variable in the default or embedded environment.
5691 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5692 regular expression. This allows multiple variables to be connected to
5693 the same callback without explicitly listing them all out.
5696 Command Line Parsing:
5697 =====================
5699 There are two different command line parsers available with U-Boot:
5700 the old "simple" one, and the much more powerful "hush" shell:
5702 Old, simple command line parser:
5703 --------------------------------
5705 - supports environment variables (through setenv / saveenv commands)
5706 - several commands on one line, separated by ';'
5707 - variable substitution using "... ${name} ..." syntax
5708 - special characters ('$', ';') can be escaped by prefixing with '\',
5710 setenv bootcmd bootm \${address}
5711 - You can also escape text by enclosing in single apostrophes, for example:
5712 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5717 - similar to Bourne shell, with control structures like
5718 if...then...else...fi, for...do...done; while...do...done,
5719 until...do...done, ...
5720 - supports environment ("global") variables (through setenv / saveenv
5721 commands) and local shell variables (through standard shell syntax
5722 "name=value"); only environment variables can be used with "run"
5728 (1) If a command line (or an environment variable executed by a "run"
5729 command) contains several commands separated by semicolon, and
5730 one of these commands fails, then the remaining commands will be
5733 (2) If you execute several variables with one call to run (i. e.
5734 calling run with a list of variables as arguments), any failing
5735 command will cause "run" to terminate, i. e. the remaining
5736 variables are not executed.
5738 Note for Redundant Ethernet Interfaces:
5739 =======================================
5741 Some boards come with redundant Ethernet interfaces; U-Boot supports
5742 such configurations and is capable of automatic selection of a
5743 "working" interface when needed. MAC assignment works as follows:
5745 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5746 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5747 "eth1addr" (=>eth1), "eth2addr", ...
5749 If the network interface stores some valid MAC address (for instance
5750 in SROM), this is used as default address if there is NO correspon-
5751 ding setting in the environment; if the corresponding environment
5752 variable is set, this overrides the settings in the card; that means:
5754 o If the SROM has a valid MAC address, and there is no address in the
5755 environment, the SROM's address is used.
5757 o If there is no valid address in the SROM, and a definition in the
5758 environment exists, then the value from the environment variable is
5761 o If both the SROM and the environment contain a MAC address, and
5762 both addresses are the same, this MAC address is used.
5764 o If both the SROM and the environment contain a MAC address, and the
5765 addresses differ, the value from the environment is used and a
5768 o If neither SROM nor the environment contain a MAC address, an error
5769 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5770 a random, locally-assigned MAC is used.
5772 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5773 will be programmed into hardware as part of the initialization process. This
5774 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5775 The naming convention is as follows:
5776 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5781 U-Boot is capable of booting (and performing other auxiliary operations on)
5782 images in two formats:
5784 New uImage format (FIT)
5785 -----------------------
5787 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5788 to Flattened Device Tree). It allows the use of images with multiple
5789 components (several kernels, ramdisks, etc.), with contents protected by
5790 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5796 Old image format is based on binary files which can be basically anything,
5797 preceded by a special header; see the definitions in include/image.h for
5798 details; basically, the header defines the following image properties:
5800 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5801 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5802 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5803 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5805 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5806 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5807 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5808 * Compression Type (uncompressed, gzip, bzip2)
5814 The header is marked by a special Magic Number, and both the header
5815 and the data portions of the image are secured against corruption by
5822 Although U-Boot should support any OS or standalone application
5823 easily, the main focus has always been on Linux during the design of
5826 U-Boot includes many features that so far have been part of some
5827 special "boot loader" code within the Linux kernel. Also, any
5828 "initrd" images to be used are no longer part of one big Linux image;
5829 instead, kernel and "initrd" are separate images. This implementation
5830 serves several purposes:
5832 - the same features can be used for other OS or standalone
5833 applications (for instance: using compressed images to reduce the
5834 Flash memory footprint)
5836 - it becomes much easier to port new Linux kernel versions because
5837 lots of low-level, hardware dependent stuff are done by U-Boot
5839 - the same Linux kernel image can now be used with different "initrd"
5840 images; of course this also means that different kernel images can
5841 be run with the same "initrd". This makes testing easier (you don't
5842 have to build a new "zImage.initrd" Linux image when you just
5843 change a file in your "initrd"). Also, a field-upgrade of the
5844 software is easier now.
5850 Porting Linux to U-Boot based systems:
5851 ---------------------------------------
5853 U-Boot cannot save you from doing all the necessary modifications to
5854 configure the Linux device drivers for use with your target hardware
5855 (no, we don't intend to provide a full virtual machine interface to
5858 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5860 Just make sure your machine specific header file (for instance
5861 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5862 Information structure as we define in include/asm-<arch>/u-boot.h,
5863 and make sure that your definition of IMAP_ADDR uses the same value
5864 as your U-Boot configuration in CONFIG_SYS_IMMR.
5866 Note that U-Boot now has a driver model, a unified model for drivers.
5867 If you are adding a new driver, plumb it into driver model. If there
5868 is no uclass available, you are encouraged to create one. See
5872 Configuring the Linux kernel:
5873 -----------------------------
5875 No specific requirements for U-Boot. Make sure you have some root
5876 device (initial ramdisk, NFS) for your target system.
5879 Building a Linux Image:
5880 -----------------------
5882 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5883 not used. If you use recent kernel source, a new build target
5884 "uImage" will exist which automatically builds an image usable by
5885 U-Boot. Most older kernels also have support for a "pImage" target,
5886 which was introduced for our predecessor project PPCBoot and uses a
5887 100% compatible format.
5891 make TQM850L_defconfig
5896 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5897 encapsulate a compressed Linux kernel image with header information,
5898 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5900 * build a standard "vmlinux" kernel image (in ELF binary format):
5902 * convert the kernel into a raw binary image:
5904 ${CROSS_COMPILE}-objcopy -O binary \
5905 -R .note -R .comment \
5906 -S vmlinux linux.bin
5908 * compress the binary image:
5912 * package compressed binary image for U-Boot:
5914 mkimage -A ppc -O linux -T kernel -C gzip \
5915 -a 0 -e 0 -n "Linux Kernel Image" \
5916 -d linux.bin.gz uImage
5919 The "mkimage" tool can also be used to create ramdisk images for use
5920 with U-Boot, either separated from the Linux kernel image, or
5921 combined into one file. "mkimage" encapsulates the images with a 64
5922 byte header containing information about target architecture,
5923 operating system, image type, compression method, entry points, time
5924 stamp, CRC32 checksums, etc.
5926 "mkimage" can be called in two ways: to verify existing images and
5927 print the header information, or to build new images.
5929 In the first form (with "-l" option) mkimage lists the information
5930 contained in the header of an existing U-Boot image; this includes
5931 checksum verification:
5933 tools/mkimage -l image
5934 -l ==> list image header information
5936 The second form (with "-d" option) is used to build a U-Boot image
5937 from a "data file" which is used as image payload:
5939 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5940 -n name -d data_file image
5941 -A ==> set architecture to 'arch'
5942 -O ==> set operating system to 'os'
5943 -T ==> set image type to 'type'
5944 -C ==> set compression type 'comp'
5945 -a ==> set load address to 'addr' (hex)
5946 -e ==> set entry point to 'ep' (hex)
5947 -n ==> set image name to 'name'
5948 -d ==> use image data from 'datafile'
5950 Right now, all Linux kernels for PowerPC systems use the same load
5951 address (0x00000000), but the entry point address depends on the
5954 - 2.2.x kernels have the entry point at 0x0000000C,
5955 - 2.3.x and later kernels have the entry point at 0x00000000.
5957 So a typical call to build a U-Boot image would read:
5959 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5960 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5961 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5962 > examples/uImage.TQM850L
5963 Image Name: 2.4.4 kernel for TQM850L
5964 Created: Wed Jul 19 02:34:59 2000
5965 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5966 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5967 Load Address: 0x00000000
5968 Entry Point: 0x00000000
5970 To verify the contents of the image (or check for corruption):
5972 -> tools/mkimage -l examples/uImage.TQM850L
5973 Image Name: 2.4.4 kernel for TQM850L
5974 Created: Wed Jul 19 02:34:59 2000
5975 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5976 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5977 Load Address: 0x00000000
5978 Entry Point: 0x00000000
5980 NOTE: for embedded systems where boot time is critical you can trade
5981 speed for memory and install an UNCOMPRESSED image instead: this
5982 needs more space in Flash, but boots much faster since it does not
5983 need to be uncompressed:
5985 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5986 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5987 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5988 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5989 > examples/uImage.TQM850L-uncompressed
5990 Image Name: 2.4.4 kernel for TQM850L
5991 Created: Wed Jul 19 02:34:59 2000
5992 Image Type: PowerPC Linux Kernel Image (uncompressed)
5993 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5994 Load Address: 0x00000000
5995 Entry Point: 0x00000000
5998 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5999 when your kernel is intended to use an initial ramdisk:
6001 -> tools/mkimage -n 'Simple Ramdisk Image' \
6002 > -A ppc -O linux -T ramdisk -C gzip \
6003 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
6004 Image Name: Simple Ramdisk Image
6005 Created: Wed Jan 12 14:01:50 2000
6006 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6007 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
6008 Load Address: 0x00000000
6009 Entry Point: 0x00000000
6011 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
6012 option performs the converse operation of the mkimage's second form (the "-d"
6013 option). Given an image built by mkimage, the dumpimage extracts a "data file"
6016 tools/dumpimage -i image -T type -p position data_file
6017 -i ==> extract from the 'image' a specific 'data_file'
6018 -T ==> set image type to 'type'
6019 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6022 Installing a Linux Image:
6023 -------------------------
6025 To downloading a U-Boot image over the serial (console) interface,
6026 you must convert the image to S-Record format:
6028 objcopy -I binary -O srec examples/image examples/image.srec
6030 The 'objcopy' does not understand the information in the U-Boot
6031 image header, so the resulting S-Record file will be relative to
6032 address 0x00000000. To load it to a given address, you need to
6033 specify the target address as 'offset' parameter with the 'loads'
6036 Example: install the image to address 0x40100000 (which on the
6037 TQM8xxL is in the first Flash bank):
6039 => erase 40100000 401FFFFF
6045 ## Ready for S-Record download ...
6046 ~>examples/image.srec
6047 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6049 15989 15990 15991 15992
6050 [file transfer complete]
6052 ## Start Addr = 0x00000000
6055 You can check the success of the download using the 'iminfo' command;
6056 this includes a checksum verification so you can be sure no data
6057 corruption happened:
6061 ## Checking Image at 40100000 ...
6062 Image Name: 2.2.13 for initrd on TQM850L
6063 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6064 Data Size: 335725 Bytes = 327 kB = 0 MB
6065 Load Address: 00000000
6066 Entry Point: 0000000c
6067 Verifying Checksum ... OK
6073 The "bootm" command is used to boot an application that is stored in
6074 memory (RAM or Flash). In case of a Linux kernel image, the contents
6075 of the "bootargs" environment variable is passed to the kernel as
6076 parameters. You can check and modify this variable using the
6077 "printenv" and "setenv" commands:
6080 => printenv bootargs
6081 bootargs=root=/dev/ram
6083 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6085 => printenv bootargs
6086 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6089 ## Booting Linux kernel at 40020000 ...
6090 Image Name: 2.2.13 for NFS on TQM850L
6091 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6092 Data Size: 381681 Bytes = 372 kB = 0 MB
6093 Load Address: 00000000
6094 Entry Point: 0000000c
6095 Verifying Checksum ... OK
6096 Uncompressing Kernel Image ... OK
6097 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
6098 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6099 time_init: decrementer frequency = 187500000/60
6100 Calibrating delay loop... 49.77 BogoMIPS
6101 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6104 If you want to boot a Linux kernel with initial RAM disk, you pass
6105 the memory addresses of both the kernel and the initrd image (PPBCOOT
6106 format!) to the "bootm" command:
6108 => imi 40100000 40200000
6110 ## Checking Image at 40100000 ...
6111 Image Name: 2.2.13 for initrd on TQM850L
6112 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6113 Data Size: 335725 Bytes = 327 kB = 0 MB
6114 Load Address: 00000000
6115 Entry Point: 0000000c
6116 Verifying Checksum ... OK
6118 ## Checking Image at 40200000 ...
6119 Image Name: Simple Ramdisk Image
6120 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6121 Data Size: 566530 Bytes = 553 kB = 0 MB
6122 Load Address: 00000000
6123 Entry Point: 00000000
6124 Verifying Checksum ... OK
6126 => bootm 40100000 40200000
6127 ## Booting Linux kernel at 40100000 ...
6128 Image Name: 2.2.13 for initrd on TQM850L
6129 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6130 Data Size: 335725 Bytes = 327 kB = 0 MB
6131 Load Address: 00000000
6132 Entry Point: 0000000c
6133 Verifying Checksum ... OK
6134 Uncompressing Kernel Image ... OK
6135 ## Loading RAMDisk Image at 40200000 ...
6136 Image Name: Simple Ramdisk Image
6137 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6138 Data Size: 566530 Bytes = 553 kB = 0 MB
6139 Load Address: 00000000
6140 Entry Point: 00000000
6141 Verifying Checksum ... OK
6142 Loading Ramdisk ... OK
6143 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
6144 Boot arguments: root=/dev/ram
6145 time_init: decrementer frequency = 187500000/60
6146 Calibrating delay loop... 49.77 BogoMIPS
6148 RAMDISK: Compressed image found at block 0
6149 VFS: Mounted root (ext2 filesystem).
6153 Boot Linux and pass a flat device tree:
6156 First, U-Boot must be compiled with the appropriate defines. See the section
6157 titled "Linux Kernel Interface" above for a more in depth explanation. The
6158 following is an example of how to start a kernel and pass an updated
6164 oft=oftrees/mpc8540ads.dtb
6165 => tftp $oftaddr $oft
6166 Speed: 1000, full duplex
6168 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6169 Filename 'oftrees/mpc8540ads.dtb'.
6170 Load address: 0x300000
6173 Bytes transferred = 4106 (100a hex)
6174 => tftp $loadaddr $bootfile
6175 Speed: 1000, full duplex
6177 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6179 Load address: 0x200000
6180 Loading:############
6182 Bytes transferred = 1029407 (fb51f hex)
6187 => bootm $loadaddr - $oftaddr
6188 ## Booting image at 00200000 ...
6189 Image Name: Linux-2.6.17-dirty
6190 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6191 Data Size: 1029343 Bytes = 1005.2 kB
6192 Load Address: 00000000
6193 Entry Point: 00000000
6194 Verifying Checksum ... OK
6195 Uncompressing Kernel Image ... OK
6196 Booting using flat device tree at 0x300000
6197 Using MPC85xx ADS machine description
6198 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6202 More About U-Boot Image Types:
6203 ------------------------------
6205 U-Boot supports the following image types:
6207 "Standalone Programs" are directly runnable in the environment
6208 provided by U-Boot; it is expected that (if they behave
6209 well) you can continue to work in U-Boot after return from
6210 the Standalone Program.
6211 "OS Kernel Images" are usually images of some Embedded OS which
6212 will take over control completely. Usually these programs
6213 will install their own set of exception handlers, device
6214 drivers, set up the MMU, etc. - this means, that you cannot
6215 expect to re-enter U-Boot except by resetting the CPU.
6216 "RAMDisk Images" are more or less just data blocks, and their
6217 parameters (address, size) are passed to an OS kernel that is
6219 "Multi-File Images" contain several images, typically an OS
6220 (Linux) kernel image and one or more data images like
6221 RAMDisks. This construct is useful for instance when you want
6222 to boot over the network using BOOTP etc., where the boot
6223 server provides just a single image file, but you want to get
6224 for instance an OS kernel and a RAMDisk image.
6226 "Multi-File Images" start with a list of image sizes, each
6227 image size (in bytes) specified by an "uint32_t" in network
6228 byte order. This list is terminated by an "(uint32_t)0".
6229 Immediately after the terminating 0 follow the images, one by
6230 one, all aligned on "uint32_t" boundaries (size rounded up to
6231 a multiple of 4 bytes).
6233 "Firmware Images" are binary images containing firmware (like
6234 U-Boot or FPGA images) which usually will be programmed to
6237 "Script files" are command sequences that will be executed by
6238 U-Boot's command interpreter; this feature is especially
6239 useful when you configure U-Boot to use a real shell (hush)
6240 as command interpreter.
6242 Booting the Linux zImage:
6243 -------------------------
6245 On some platforms, it's possible to boot Linux zImage. This is done
6246 using the "bootz" command. The syntax of "bootz" command is the same
6247 as the syntax of "bootm" command.
6249 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6250 kernel with raw initrd images. The syntax is slightly different, the
6251 address of the initrd must be augmented by it's size, in the following
6252 format: "<initrd addres>:<initrd size>".
6258 One of the features of U-Boot is that you can dynamically load and
6259 run "standalone" applications, which can use some resources of
6260 U-Boot like console I/O functions or interrupt services.
6262 Two simple examples are included with the sources:
6267 'examples/hello_world.c' contains a small "Hello World" Demo
6268 application; it is automatically compiled when you build U-Boot.
6269 It's configured to run at address 0x00040004, so you can play with it
6273 ## Ready for S-Record download ...
6274 ~>examples/hello_world.srec
6275 1 2 3 4 5 6 7 8 9 10 11 ...
6276 [file transfer complete]
6278 ## Start Addr = 0x00040004
6280 => go 40004 Hello World! This is a test.
6281 ## Starting application at 0x00040004 ...
6292 Hit any key to exit ...
6294 ## Application terminated, rc = 0x0
6296 Another example, which demonstrates how to register a CPM interrupt
6297 handler with the U-Boot code, can be found in 'examples/timer.c'.
6298 Here, a CPM timer is set up to generate an interrupt every second.
6299 The interrupt service routine is trivial, just printing a '.'
6300 character, but this is just a demo program. The application can be
6301 controlled by the following keys:
6303 ? - print current values og the CPM Timer registers
6304 b - enable interrupts and start timer
6305 e - stop timer and disable interrupts
6306 q - quit application
6309 ## Ready for S-Record download ...
6310 ~>examples/timer.srec
6311 1 2 3 4 5 6 7 8 9 10 11 ...
6312 [file transfer complete]
6314 ## Start Addr = 0x00040004
6317 ## Starting application at 0x00040004 ...
6320 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6323 [q, b, e, ?] Set interval 1000000 us
6326 [q, b, e, ?] ........
6327 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6330 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6333 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6336 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6338 [q, b, e, ?] ...Stopping timer
6340 [q, b, e, ?] ## Application terminated, rc = 0x0
6346 Over time, many people have reported problems when trying to use the
6347 "minicom" terminal emulation program for serial download. I (wd)
6348 consider minicom to be broken, and recommend not to use it. Under
6349 Unix, I recommend to use C-Kermit for general purpose use (and
6350 especially for kermit binary protocol download ("loadb" command), and
6351 use "cu" for S-Record download ("loads" command). See
6352 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6353 for help with kermit.
6356 Nevertheless, if you absolutely want to use it try adding this
6357 configuration to your "File transfer protocols" section:
6359 Name Program Name U/D FullScr IO-Red. Multi
6360 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6361 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6367 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6368 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6370 Building requires a cross environment; it is known to work on
6371 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6372 need gmake since the Makefiles are not compatible with BSD make).
6373 Note that the cross-powerpc package does not install include files;
6374 attempting to build U-Boot will fail because <machine/ansi.h> is
6375 missing. This file has to be installed and patched manually:
6377 # cd /usr/pkg/cross/powerpc-netbsd/include
6379 # ln -s powerpc machine
6380 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6381 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6383 Native builds *don't* work due to incompatibilities between native
6384 and U-Boot include files.
6386 Booting assumes that (the first part of) the image booted is a
6387 stage-2 loader which in turn loads and then invokes the kernel
6388 proper. Loader sources will eventually appear in the NetBSD source
6389 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6390 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6393 Implementation Internals:
6394 =========================
6396 The following is not intended to be a complete description of every
6397 implementation detail. However, it should help to understand the
6398 inner workings of U-Boot and make it easier to port it to custom
6402 Initial Stack, Global Data:
6403 ---------------------------
6405 The implementation of U-Boot is complicated by the fact that U-Boot
6406 starts running out of ROM (flash memory), usually without access to
6407 system RAM (because the memory controller is not initialized yet).
6408 This means that we don't have writable Data or BSS segments, and BSS
6409 is not initialized as zero. To be able to get a C environment working
6410 at all, we have to allocate at least a minimal stack. Implementation
6411 options for this are defined and restricted by the CPU used: Some CPU
6412 models provide on-chip memory (like the IMMR area on MPC8xx and
6413 MPC826x processors), on others (parts of) the data cache can be
6414 locked as (mis-) used as memory, etc.
6416 Chris Hallinan posted a good summary of these issues to the
6417 U-Boot mailing list:
6419 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6420 From: "Chris Hallinan" <clh@net1plus.com>
6421 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6424 Correct me if I'm wrong, folks, but the way I understand it
6425 is this: Using DCACHE as initial RAM for Stack, etc, does not
6426 require any physical RAM backing up the cache. The cleverness
6427 is that the cache is being used as a temporary supply of
6428 necessary storage before the SDRAM controller is setup. It's
6429 beyond the scope of this list to explain the details, but you
6430 can see how this works by studying the cache architecture and
6431 operation in the architecture and processor-specific manuals.
6433 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6434 is another option for the system designer to use as an
6435 initial stack/RAM area prior to SDRAM being available. Either
6436 option should work for you. Using CS 4 should be fine if your
6437 board designers haven't used it for something that would
6438 cause you grief during the initial boot! It is frequently not
6441 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6442 with your processor/board/system design. The default value
6443 you will find in any recent u-boot distribution in
6444 walnut.h should work for you. I'd set it to a value larger
6445 than your SDRAM module. If you have a 64MB SDRAM module, set
6446 it above 400_0000. Just make sure your board has no resources
6447 that are supposed to respond to that address! That code in
6448 start.S has been around a while and should work as is when
6449 you get the config right.
6454 It is essential to remember this, since it has some impact on the C
6455 code for the initialization procedures:
6457 * Initialized global data (data segment) is read-only. Do not attempt
6460 * Do not use any uninitialized global data (or implicitly initialized
6461 as zero data - BSS segment) at all - this is undefined, initiali-
6462 zation is performed later (when relocating to RAM).
6464 * Stack space is very limited. Avoid big data buffers or things like
6467 Having only the stack as writable memory limits means we cannot use
6468 normal global data to share information between the code. But it
6469 turned out that the implementation of U-Boot can be greatly
6470 simplified by making a global data structure (gd_t) available to all
6471 functions. We could pass a pointer to this data as argument to _all_
6472 functions, but this would bloat the code. Instead we use a feature of
6473 the GCC compiler (Global Register Variables) to share the data: we
6474 place a pointer (gd) to the global data into a register which we
6475 reserve for this purpose.
6477 When choosing a register for such a purpose we are restricted by the
6478 relevant (E)ABI specifications for the current architecture, and by
6479 GCC's implementation.
6481 For PowerPC, the following registers have specific use:
6483 R2: reserved for system use
6484 R3-R4: parameter passing and return values
6485 R5-R10: parameter passing
6486 R13: small data area pointer
6490 (U-Boot also uses R12 as internal GOT pointer. r12
6491 is a volatile register so r12 needs to be reset when
6492 going back and forth between asm and C)
6494 ==> U-Boot will use R2 to hold a pointer to the global data
6496 Note: on PPC, we could use a static initializer (since the
6497 address of the global data structure is known at compile time),
6498 but it turned out that reserving a register results in somewhat
6499 smaller code - although the code savings are not that big (on
6500 average for all boards 752 bytes for the whole U-Boot image,
6501 624 text + 127 data).
6503 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6504 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6506 ==> U-Boot will use P3 to hold a pointer to the global data
6508 On ARM, the following registers are used:
6510 R0: function argument word/integer result
6511 R1-R3: function argument word
6512 R9: platform specific
6513 R10: stack limit (used only if stack checking is enabled)
6514 R11: argument (frame) pointer
6515 R12: temporary workspace
6518 R15: program counter
6520 ==> U-Boot will use R9 to hold a pointer to the global data
6522 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6524 On Nios II, the ABI is documented here:
6525 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6527 ==> U-Boot will use gp to hold a pointer to the global data
6529 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6530 to access small data sections, so gp is free.
6532 On NDS32, the following registers are used:
6534 R0-R1: argument/return
6536 R15: temporary register for assembler
6537 R16: trampoline register
6538 R28: frame pointer (FP)
6539 R29: global pointer (GP)
6540 R30: link register (LP)
6541 R31: stack pointer (SP)
6542 PC: program counter (PC)
6544 ==> U-Boot will use R10 to hold a pointer to the global data
6546 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6547 or current versions of GCC may "optimize" the code too much.
6552 U-Boot runs in system state and uses physical addresses, i.e. the
6553 MMU is not used either for address mapping nor for memory protection.
6555 The available memory is mapped to fixed addresses using the memory
6556 controller. In this process, a contiguous block is formed for each
6557 memory type (Flash, SDRAM, SRAM), even when it consists of several
6558 physical memory banks.
6560 U-Boot is installed in the first 128 kB of the first Flash bank (on
6561 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6562 booting and sizing and initializing DRAM, the code relocates itself
6563 to the upper end of DRAM. Immediately below the U-Boot code some
6564 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6565 configuration setting]. Below that, a structure with global Board
6566 Info data is placed, followed by the stack (growing downward).
6568 Additionally, some exception handler code is copied to the low 8 kB
6569 of DRAM (0x00000000 ... 0x00001FFF).
6571 So a typical memory configuration with 16 MB of DRAM could look like
6574 0x0000 0000 Exception Vector code
6577 0x0000 2000 Free for Application Use
6583 0x00FB FF20 Monitor Stack (Growing downward)
6584 0x00FB FFAC Board Info Data and permanent copy of global data
6585 0x00FC 0000 Malloc Arena
6588 0x00FE 0000 RAM Copy of Monitor Code
6589 ... eventually: LCD or video framebuffer
6590 ... eventually: pRAM (Protected RAM - unchanged by reset)
6591 0x00FF FFFF [End of RAM]
6594 System Initialization:
6595 ----------------------
6597 In the reset configuration, U-Boot starts at the reset entry point
6598 (on most PowerPC systems at address 0x00000100). Because of the reset
6599 configuration for CS0# this is a mirror of the on board Flash memory.
6600 To be able to re-map memory U-Boot then jumps to its link address.
6601 To be able to implement the initialization code in C, a (small!)
6602 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6603 which provide such a feature like MPC8xx or MPC8260), or in a locked
6604 part of the data cache. After that, U-Boot initializes the CPU core,
6605 the caches and the SIU.
6607 Next, all (potentially) available memory banks are mapped using a
6608 preliminary mapping. For example, we put them on 512 MB boundaries
6609 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6610 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6611 programmed for SDRAM access. Using the temporary configuration, a
6612 simple memory test is run that determines the size of the SDRAM
6615 When there is more than one SDRAM bank, and the banks are of
6616 different size, the largest is mapped first. For equal size, the first
6617 bank (CS2#) is mapped first. The first mapping is always for address
6618 0x00000000, with any additional banks following immediately to create
6619 contiguous memory starting from 0.
6621 Then, the monitor installs itself at the upper end of the SDRAM area
6622 and allocates memory for use by malloc() and for the global Board
6623 Info data; also, the exception vector code is copied to the low RAM
6624 pages, and the final stack is set up.
6626 Only after this relocation will you have a "normal" C environment;
6627 until that you are restricted in several ways, mostly because you are
6628 running from ROM, and because the code will have to be relocated to a
6632 U-Boot Porting Guide:
6633 ----------------------
6635 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6639 int main(int argc, char *argv[])
6641 sighandler_t no_more_time;
6643 signal(SIGALRM, no_more_time);
6644 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6646 if (available_money > available_manpower) {
6647 Pay consultant to port U-Boot;
6651 Download latest U-Boot source;
6653 Subscribe to u-boot mailing list;
6656 email("Hi, I am new to U-Boot, how do I get started?");
6659 Read the README file in the top level directory;
6660 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6661 Read applicable doc/*.README;
6662 Read the source, Luke;
6663 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6666 if (available_money > toLocalCurrency ($2500))
6669 Add a lot of aggravation and time;
6671 if (a similar board exists) { /* hopefully... */
6672 cp -a board/<similar> board/<myboard>
6673 cp include/configs/<similar>.h include/configs/<myboard>.h
6675 Create your own board support subdirectory;
6676 Create your own board include/configs/<myboard>.h file;
6678 Edit new board/<myboard> files
6679 Edit new include/configs/<myboard>.h
6684 Add / modify source code;
6688 email("Hi, I am having problems...");
6690 Send patch file to the U-Boot email list;
6691 if (reasonable critiques)
6692 Incorporate improvements from email list code review;
6694 Defend code as written;
6700 void no_more_time (int sig)
6709 All contributions to U-Boot should conform to the Linux kernel
6710 coding style; see the file "Documentation/CodingStyle" and the script
6711 "scripts/Lindent" in your Linux kernel source directory.
6713 Source files originating from a different project (for example the
6714 MTD subsystem) are generally exempt from these guidelines and are not
6715 reformatted to ease subsequent migration to newer versions of those
6718 Please note that U-Boot is implemented in C (and to some small parts in
6719 Assembler); no C++ is used, so please do not use C++ style comments (//)
6722 Please also stick to the following formatting rules:
6723 - remove any trailing white space
6724 - use TAB characters for indentation and vertical alignment, not spaces
6725 - make sure NOT to use DOS '\r\n' line feeds
6726 - do not add more than 2 consecutive empty lines to source files
6727 - do not add trailing empty lines to source files
6729 Submissions which do not conform to the standards may be returned
6730 with a request to reformat the changes.
6736 Since the number of patches for U-Boot is growing, we need to
6737 establish some rules. Submissions which do not conform to these rules
6738 may be rejected, even when they contain important and valuable stuff.
6740 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6742 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6743 see http://lists.denx.de/mailman/listinfo/u-boot
6745 When you send a patch, please include the following information with
6748 * For bug fixes: a description of the bug and how your patch fixes
6749 this bug. Please try to include a way of demonstrating that the
6750 patch actually fixes something.
6752 * For new features: a description of the feature and your
6755 * A CHANGELOG entry as plaintext (separate from the patch)
6757 * For major contributions, your entry to the CREDITS file
6759 * When you add support for a new board, don't forget to add a
6760 maintainer e-mail address to the boards.cfg file, too.
6762 * If your patch adds new configuration options, don't forget to
6763 document these in the README file.
6765 * The patch itself. If you are using git (which is *strongly*
6766 recommended) you can easily generate the patch using the
6767 "git format-patch". If you then use "git send-email" to send it to
6768 the U-Boot mailing list, you will avoid most of the common problems
6769 with some other mail clients.
6771 If you cannot use git, use "diff -purN OLD NEW". If your version of
6772 diff does not support these options, then get the latest version of
6775 The current directory when running this command shall be the parent
6776 directory of the U-Boot source tree (i. e. please make sure that
6777 your patch includes sufficient directory information for the
6780 We prefer patches as plain text. MIME attachments are discouraged,
6781 and compressed attachments must not be used.
6783 * If one logical set of modifications affects or creates several
6784 files, all these changes shall be submitted in a SINGLE patch file.
6786 * Changesets that contain different, unrelated modifications shall be
6787 submitted as SEPARATE patches, one patch per changeset.
6792 * Before sending the patch, run the MAKEALL script on your patched
6793 source tree and make sure that no errors or warnings are reported
6794 for any of the boards.
6796 * Keep your modifications to the necessary minimum: A patch
6797 containing several unrelated changes or arbitrary reformats will be
6798 returned with a request to re-formatting / split it.
6800 * If you modify existing code, make sure that your new code does not
6801 add to the memory footprint of the code ;-) Small is beautiful!
6802 When adding new features, these should compile conditionally only
6803 (using #ifdef), and the resulting code with the new feature
6804 disabled must not need more memory than the old code without your
6807 * Remember that there is a size limit of 100 kB per message on the
6808 u-boot mailing list. Bigger patches will be moderated. If they are
6809 reasonable and not too big, they will be acknowledged. But patches
6810 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob