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!
693 NOTE: The following can be machine specific errata. These
694 do have ability to provide rudimentary version and machine
695 specific checks, but expect no product checks.
696 CONFIG_ARM_ERRATA_430973
697 CONFIG_ARM_ERRATA_454179
698 CONFIG_ARM_ERRATA_798870
701 CONFIG_TEGRA_SUPPORT_NON_SECURE
703 Support executing U-Boot in non-secure (NS) mode. Certain
704 impossible actions will be skipped if the CPU is in NS mode,
705 such as ARM architectural timer initialization.
708 Driver model is a new framework for devices in U-Boot
709 introduced in early 2014. U-Boot is being progressively
710 moved over to this. It offers a consistent device structure,
711 supports grouping devices into classes and has built-in
712 handling of platform data and device tree.
714 To enable transition to driver model in a relatively
715 painful fashion, each subsystem can be independently
716 switched between the legacy/ad-hoc approach and the new
717 driver model using the options below. Also, many uclass
718 interfaces include compatibility features which may be
719 removed once the conversion of that subsystem is complete.
720 As a result, the API provided by the subsystem may in fact
721 not change with driver model.
723 See doc/driver-model/README.txt for more information.
727 Enable driver model. This brings in the core support,
728 including scanning of platform data on start-up. If
729 CONFIG_OF_CONTROL is enabled, the device tree will be
730 scanned also when available.
734 Enable driver model test commands. These allow you to print
735 out the driver model tree and the uclasses.
739 Enable some demo devices and the 'demo' command. These are
740 really only useful for playing around while trying to
741 understand driver model in sandbox.
745 Enable driver model in SPL. You will need to provide a
746 suitable malloc() implementation. If you are not using the
747 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
748 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
749 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
750 In most cases driver model will only allocate a few uclasses
751 and devices in SPL, so 1KB should be enable. See
752 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
757 Enable driver model for serial. This replaces
758 drivers/serial/serial.c with the serial uclass, which
759 implements serial_putc() etc. The uclass interface is
760 defined in include/serial.h.
764 Enable driver model for GPIO access. The standard GPIO
765 interface (gpio_get_value(), etc.) is then implemented by
766 the GPIO uclass. Drivers provide methods to query the
767 particular GPIOs that they provide. The uclass interface
768 is defined in include/asm-generic/gpio.h.
772 Enable driver model for SPI. The SPI slave interface
773 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
774 the SPI uclass. Drivers provide methods to access the SPI
775 buses that they control. The uclass interface is defined in
776 include/spi.h. The existing spi_slave structure is attached
777 as 'parent data' to every slave on each bus. Slaves
778 typically use driver-private data instead of extending the
783 Enable driver model for SPI flash. This SPI flash interface
784 (spi_flash_probe(), spi_flash_write(), etc.) is then
785 implemented by the SPI flash uclass. There is one standard
786 SPI flash driver which knows how to probe most chips
787 supported by U-Boot. The uclass interface is defined in
788 include/spi_flash.h, but is currently fully compatible
789 with the old interface to avoid confusion and duplication
790 during the transition parent. SPI and SPI flash must be
791 enabled together (it is not possible to use driver model
792 for one and not the other).
796 Enable driver model for the Chrome OS EC interface. This
797 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
798 but otherwise makes few changes. Since cros_ec also supports
799 I2C and LPC (which don't support driver model yet), a full
800 conversion is not yet possible.
803 ** Code size options: The following options are enabled by
804 default except in SPL. Enable them explicitly to get these
809 Enable the dm_warn() function. This can use up quite a bit
810 of space for its strings.
814 Enable registering a serial device with the stdio library.
816 CONFIG_DM_DEVICE_REMOVE
818 Enable removing of devices.
820 - Linux Kernel Interface:
823 U-Boot stores all clock information in Hz
824 internally. For binary compatibility with older Linux
825 kernels (which expect the clocks passed in the
826 bd_info data to be in MHz) the environment variable
827 "clocks_in_mhz" can be defined so that U-Boot
828 converts clock data to MHZ before passing it to the
830 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
831 "clocks_in_mhz=1" is automatically included in the
834 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
836 When transferring memsize parameter to Linux, some versions
837 expect it to be in bytes, others in MB.
838 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
842 New kernel versions are expecting firmware settings to be
843 passed using flattened device trees (based on open firmware
847 * New libfdt-based support
848 * Adds the "fdt" command
849 * The bootm command automatically updates the fdt
851 OF_CPU - The proper name of the cpus node (only required for
852 MPC512X and MPC5xxx based boards).
853 OF_SOC - The proper name of the soc node (only required for
854 MPC512X and MPC5xxx based boards).
855 OF_TBCLK - The timebase frequency.
856 OF_STDOUT_PATH - The path to the console device
858 boards with QUICC Engines require OF_QE to set UCC MAC
861 CONFIG_OF_BOARD_SETUP
863 Board code has addition modification that it wants to make
864 to the flat device tree before handing it off to the kernel
866 CONFIG_OF_SYSTEM_SETUP
868 Other code has addition modification that it wants to make
869 to the flat device tree before handing it off to the kernel.
870 This causes ft_system_setup() to be called before booting
875 This define fills in the correct boot CPU in the boot
876 param header, the default value is zero if undefined.
880 U-Boot can detect if an IDE device is present or not.
881 If not, and this new config option is activated, U-Boot
882 removes the ATA node from the DTS before booting Linux,
883 so the Linux IDE driver does not probe the device and
884 crash. This is needed for buggy hardware (uc101) where
885 no pull down resistor is connected to the signal IDE5V_DD7.
887 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
889 This setting is mandatory for all boards that have only one
890 machine type and must be used to specify the machine type
891 number as it appears in the ARM machine registry
892 (see http://www.arm.linux.org.uk/developer/machines/).
893 Only boards that have multiple machine types supported
894 in a single configuration file and the machine type is
895 runtime discoverable, do not have to use this setting.
897 - vxWorks boot parameters:
899 bootvx constructs a valid bootline using the following
900 environments variables: bootfile, ipaddr, serverip, hostname.
901 It loads the vxWorks image pointed bootfile.
903 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
904 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
905 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
906 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
908 CONFIG_SYS_VXWORKS_ADD_PARAMS
910 Add it at the end of the bootline. E.g "u=username pw=secret"
912 Note: If a "bootargs" environment is defined, it will overwride
913 the defaults discussed just above.
915 - Cache Configuration:
916 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
917 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
918 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
920 - Cache Configuration for ARM:
921 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
923 CONFIG_SYS_PL310_BASE - Physical base address of PL310
924 controller register space
929 Define this if you want support for Amba PrimeCell PL010 UARTs.
933 Define this if you want support for Amba PrimeCell PL011 UARTs.
937 If you have Amba PrimeCell PL011 UARTs, set this variable to
938 the clock speed of the UARTs.
942 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
943 define this to a list of base addresses for each (supported)
944 port. See e.g. include/configs/versatile.h
946 CONFIG_PL011_SERIAL_RLCR
948 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
949 have separate receive and transmit line control registers. Set
950 this variable to initialize the extra register.
952 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
954 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
955 boot loader that has already initialized the UART. Define this
956 variable to flush the UART at init time.
958 CONFIG_SERIAL_HW_FLOW_CONTROL
960 Define this variable to enable hw flow control in serial driver.
961 Current user of this option is drivers/serial/nsl16550.c driver
964 Depending on board, define exactly one serial port
965 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
966 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
967 console by defining CONFIG_8xx_CONS_NONE
969 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
970 port routines must be defined elsewhere
971 (i.e. serial_init(), serial_getc(), ...)
974 Enables console device for a color framebuffer. Needs following
975 defines (cf. smiLynxEM, i8042)
976 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
978 VIDEO_HW_RECTFILL graphic chip supports
981 VIDEO_HW_BITBLT graphic chip supports
982 bit-blit (cf. smiLynxEM)
983 VIDEO_VISIBLE_COLS visible pixel columns
985 VIDEO_VISIBLE_ROWS visible pixel rows
986 VIDEO_PIXEL_SIZE bytes per pixel
987 VIDEO_DATA_FORMAT graphic data format
988 (0-5, cf. cfb_console.c)
989 VIDEO_FB_ADRS framebuffer address
990 VIDEO_KBD_INIT_FCT keyboard int fct
991 (i.e. i8042_kbd_init())
992 VIDEO_TSTC_FCT test char fct
994 VIDEO_GETC_FCT get char fct
996 CONFIG_CONSOLE_CURSOR cursor drawing on/off
997 (requires blink timer
999 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
1000 CONFIG_CONSOLE_TIME display time/date info in
1002 (requires CONFIG_CMD_DATE)
1003 CONFIG_VIDEO_LOGO display Linux logo in
1005 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
1006 linux_logo.h for logo.
1007 Requires CONFIG_VIDEO_LOGO
1008 CONFIG_CONSOLE_EXTRA_INFO
1009 additional board info beside
1012 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
1013 a limited number of ANSI escape sequences (cursor control,
1014 erase functions and limited graphics rendition control).
1016 When CONFIG_CFB_CONSOLE is defined, video console is
1017 default i/o. Serial console can be forced with
1018 environment 'console=serial'.
1020 When CONFIG_SILENT_CONSOLE is defined, all console
1021 messages (by U-Boot and Linux!) can be silenced with
1022 the "silent" environment variable. See
1023 doc/README.silent for more information.
1025 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
1027 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
1031 CONFIG_BAUDRATE - in bps
1032 Select one of the baudrates listed in
1033 CONFIG_SYS_BAUDRATE_TABLE, see below.
1034 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
1036 - Console Rx buffer length
1037 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
1038 the maximum receive buffer length for the SMC.
1039 This option is actual only for 82xx and 8xx possible.
1040 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
1041 must be defined, to setup the maximum idle timeout for
1044 - Pre-Console Buffer:
1045 Prior to the console being initialised (i.e. serial UART
1046 initialised etc) all console output is silently discarded.
1047 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
1048 buffer any console messages prior to the console being
1049 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
1050 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
1051 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
1052 bytes are output before the console is initialised, the
1053 earlier bytes are discarded.
1055 'Sane' compilers will generate smaller code if
1056 CONFIG_PRE_CON_BUF_SZ is a power of 2
1058 - Safe printf() functions
1059 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
1060 the printf() functions. These are defined in
1061 include/vsprintf.h and include snprintf(), vsnprintf() and
1062 so on. Code size increase is approximately 300-500 bytes.
1063 If this option is not given then these functions will
1064 silently discard their buffer size argument - this means
1065 you are not getting any overflow checking in this case.
1067 - Boot Delay: CONFIG_BOOTDELAY - in seconds
1068 Delay before automatically booting the default image;
1069 set to -1 to disable autoboot.
1070 set to -2 to autoboot with no delay and not check for abort
1071 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
1073 See doc/README.autoboot for these options that
1074 work with CONFIG_BOOTDELAY. None are required.
1075 CONFIG_BOOT_RETRY_TIME
1076 CONFIG_BOOT_RETRY_MIN
1077 CONFIG_AUTOBOOT_KEYED
1078 CONFIG_AUTOBOOT_PROMPT
1079 CONFIG_AUTOBOOT_DELAY_STR
1080 CONFIG_AUTOBOOT_STOP_STR
1081 CONFIG_AUTOBOOT_DELAY_STR2
1082 CONFIG_AUTOBOOT_STOP_STR2
1083 CONFIG_ZERO_BOOTDELAY_CHECK
1084 CONFIG_RESET_TO_RETRY
1088 Only needed when CONFIG_BOOTDELAY is enabled;
1089 define a command string that is automatically executed
1090 when no character is read on the console interface
1091 within "Boot Delay" after reset.
1094 This can be used to pass arguments to the bootm
1095 command. The value of CONFIG_BOOTARGS goes into the
1096 environment value "bootargs".
1098 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1099 The value of these goes into the environment as
1100 "ramboot" and "nfsboot" respectively, and can be used
1101 as a convenience, when switching between booting from
1105 CONFIG_BOOTCOUNT_LIMIT
1106 Implements a mechanism for detecting a repeating reboot
1108 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1110 CONFIG_BOOTCOUNT_ENV
1111 If no softreset save registers are found on the hardware
1112 "bootcount" is stored in the environment. To prevent a
1113 saveenv on all reboots, the environment variable
1114 "upgrade_available" is used. If "upgrade_available" is
1115 0, "bootcount" is always 0, if "upgrade_available" is
1116 1 "bootcount" is incremented in the environment.
1117 So the Userspace Applikation must set the "upgrade_available"
1118 and "bootcount" variable to 0, if a boot was successfully.
1120 - Pre-Boot Commands:
1123 When this option is #defined, the existence of the
1124 environment variable "preboot" will be checked
1125 immediately before starting the CONFIG_BOOTDELAY
1126 countdown and/or running the auto-boot command resp.
1127 entering interactive mode.
1129 This feature is especially useful when "preboot" is
1130 automatically generated or modified. For an example
1131 see the LWMON board specific code: here "preboot" is
1132 modified when the user holds down a certain
1133 combination of keys on the (special) keyboard when
1136 - Serial Download Echo Mode:
1138 If defined to 1, all characters received during a
1139 serial download (using the "loads" command) are
1140 echoed back. This might be needed by some terminal
1141 emulations (like "cu"), but may as well just take
1142 time on others. This setting #define's the initial
1143 value of the "loads_echo" environment variable.
1145 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1146 CONFIG_KGDB_BAUDRATE
1147 Select one of the baudrates listed in
1148 CONFIG_SYS_BAUDRATE_TABLE, see below.
1150 - Monitor Functions:
1151 Monitor commands can be included or excluded
1152 from the build by using the #include files
1153 <config_cmd_all.h> and #undef'ing unwanted
1154 commands, or using <config_cmd_default.h>
1155 and augmenting with additional #define's
1156 for wanted commands.
1158 The default command configuration includes all commands
1159 except those marked below with a "*".
1161 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1162 CONFIG_CMD_ASKENV * ask for env variable
1163 CONFIG_CMD_BDI bdinfo
1164 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1165 CONFIG_CMD_BMP * BMP support
1166 CONFIG_CMD_BSP * Board specific commands
1167 CONFIG_CMD_BOOTD bootd
1168 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1169 CONFIG_CMD_CACHE * icache, dcache
1170 CONFIG_CMD_CLK * clock command support
1171 CONFIG_CMD_CONSOLE coninfo
1172 CONFIG_CMD_CRC32 * crc32
1173 CONFIG_CMD_DATE * support for RTC, date/time...
1174 CONFIG_CMD_DHCP * DHCP support
1175 CONFIG_CMD_DIAG * Diagnostics
1176 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1177 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1178 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1179 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1180 CONFIG_CMD_DTT * Digital Therm and Thermostat
1181 CONFIG_CMD_ECHO echo arguments
1182 CONFIG_CMD_EDITENV edit env variable
1183 CONFIG_CMD_EEPROM * EEPROM read/write support
1184 CONFIG_CMD_ELF * bootelf, bootvx
1185 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1186 CONFIG_CMD_ENV_FLAGS * display details about env flags
1187 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1188 CONFIG_CMD_EXPORTENV * export the environment
1189 CONFIG_CMD_EXT2 * ext2 command support
1190 CONFIG_CMD_EXT4 * ext4 command support
1191 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1192 that work for multiple fs types
1193 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1194 CONFIG_CMD_SAVEENV saveenv
1195 CONFIG_CMD_FDC * Floppy Disk Support
1196 CONFIG_CMD_FAT * FAT command support
1197 CONFIG_CMD_FLASH flinfo, erase, protect
1198 CONFIG_CMD_FPGA FPGA device initialization support
1199 CONFIG_CMD_FUSE * Device fuse support
1200 CONFIG_CMD_GETTIME * Get time since boot
1201 CONFIG_CMD_GO * the 'go' command (exec code)
1202 CONFIG_CMD_GREPENV * search environment
1203 CONFIG_CMD_HASH * calculate hash / digest
1204 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1205 CONFIG_CMD_I2C * I2C serial bus support
1206 CONFIG_CMD_IDE * IDE harddisk support
1207 CONFIG_CMD_IMI iminfo
1208 CONFIG_CMD_IMLS List all images found in NOR flash
1209 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1210 CONFIG_CMD_IMMAP * IMMR dump support
1211 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1212 CONFIG_CMD_IMPORTENV * import an environment
1213 CONFIG_CMD_INI * import data from an ini file into the env
1214 CONFIG_CMD_IRQ * irqinfo
1215 CONFIG_CMD_ITEST Integer/string test of 2 values
1216 CONFIG_CMD_JFFS2 * JFFS2 Support
1217 CONFIG_CMD_KGDB * kgdb
1218 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1219 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1221 CONFIG_CMD_LOADB loadb
1222 CONFIG_CMD_LOADS loads
1223 CONFIG_CMD_MD5SUM * print md5 message digest
1224 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1225 CONFIG_CMD_MEMINFO * Display detailed memory information
1226 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1228 CONFIG_CMD_MEMTEST * mtest
1229 CONFIG_CMD_MISC Misc functions like sleep etc
1230 CONFIG_CMD_MMC * MMC memory mapped support
1231 CONFIG_CMD_MII * MII utility commands
1232 CONFIG_CMD_MTDPARTS * MTD partition support
1233 CONFIG_CMD_NAND * NAND support
1234 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1235 CONFIG_CMD_NFS NFS support
1236 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1237 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1238 CONFIG_CMD_PCI * pciinfo
1239 CONFIG_CMD_PCMCIA * PCMCIA support
1240 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1242 CONFIG_CMD_PORTIO * Port I/O
1243 CONFIG_CMD_READ * Read raw data from partition
1244 CONFIG_CMD_REGINFO * Register dump
1245 CONFIG_CMD_RUN run command in env variable
1246 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1247 CONFIG_CMD_SAVES * save S record dump
1248 CONFIG_CMD_SCSI * SCSI Support
1249 CONFIG_CMD_SDRAM * print SDRAM configuration information
1250 (requires CONFIG_CMD_I2C)
1251 CONFIG_CMD_SETGETDCR Support for DCR Register access
1253 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1254 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1255 (requires CONFIG_CMD_MEMORY)
1256 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1257 CONFIG_CMD_SOURCE "source" command Support
1258 CONFIG_CMD_SPI * SPI serial bus support
1259 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1260 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1261 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1262 CONFIG_CMD_TIMER * access to the system tick timer
1263 CONFIG_CMD_USB * USB support
1264 CONFIG_CMD_CDP * Cisco Discover Protocol support
1265 CONFIG_CMD_MFSL * Microblaze FSL support
1266 CONFIG_CMD_XIMG Load part of Multi Image
1267 CONFIG_CMD_UUID * Generate random UUID or GUID string
1269 EXAMPLE: If you want all functions except of network
1270 support you can write:
1272 #include "config_cmd_all.h"
1273 #undef CONFIG_CMD_NET
1276 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1278 Note: Don't enable the "icache" and "dcache" commands
1279 (configuration option CONFIG_CMD_CACHE) unless you know
1280 what you (and your U-Boot users) are doing. Data
1281 cache cannot be enabled on systems like the 8xx or
1282 8260 (where accesses to the IMMR region must be
1283 uncached), and it cannot be disabled on all other
1284 systems where we (mis-) use the data cache to hold an
1285 initial stack and some data.
1288 XXX - this list needs to get updated!
1290 - Regular expression support:
1292 If this variable is defined, U-Boot is linked against
1293 the SLRE (Super Light Regular Expression) library,
1294 which adds regex support to some commands, as for
1295 example "env grep" and "setexpr".
1299 If this variable is defined, U-Boot will use a device tree
1300 to configure its devices, instead of relying on statically
1301 compiled #defines in the board file. This option is
1302 experimental and only available on a few boards. The device
1303 tree is available in the global data as gd->fdt_blob.
1305 U-Boot needs to get its device tree from somewhere. This can
1306 be done using one of the two options below:
1309 If this variable is defined, U-Boot will embed a device tree
1310 binary in its image. This device tree file should be in the
1311 board directory and called <soc>-<board>.dts. The binary file
1312 is then picked up in board_init_f() and made available through
1313 the global data structure as gd->blob.
1316 If this variable is defined, U-Boot will build a device tree
1317 binary. It will be called u-boot.dtb. Architecture-specific
1318 code will locate it at run-time. Generally this works by:
1320 cat u-boot.bin u-boot.dtb >image.bin
1322 and in fact, U-Boot does this for you, creating a file called
1323 u-boot-dtb.bin which is useful in the common case. You can
1324 still use the individual files if you need something more
1329 If this variable is defined, it enables watchdog
1330 support for the SoC. There must be support in the SoC
1331 specific code for a watchdog. For the 8xx and 8260
1332 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1333 register. When supported for a specific SoC is
1334 available, then no further board specific code should
1335 be needed to use it.
1338 When using a watchdog circuitry external to the used
1339 SoC, then define this variable and provide board
1340 specific code for the "hw_watchdog_reset" function.
1342 CONFIG_AT91_HW_WDT_TIMEOUT
1343 specify the timeout in seconds. default 2 seconds.
1346 CONFIG_VERSION_VARIABLE
1347 If this variable is defined, an environment variable
1348 named "ver" is created by U-Boot showing the U-Boot
1349 version as printed by the "version" command.
1350 Any change to this variable will be reverted at the
1355 When CONFIG_CMD_DATE is selected, the type of the RTC
1356 has to be selected, too. Define exactly one of the
1359 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1360 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1361 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1362 CONFIG_RTC_MC146818 - use MC146818 RTC
1363 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1364 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1365 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1366 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1367 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1368 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1369 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1370 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1371 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1374 Note that if the RTC uses I2C, then the I2C interface
1375 must also be configured. See I2C Support, below.
1378 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1380 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1381 chip-ngpio pairs that tell the PCA953X driver the number of
1382 pins supported by a particular chip.
1384 Note that if the GPIO device uses I2C, then the I2C interface
1385 must also be configured. See I2C Support, below.
1388 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1389 accesses and can checksum them or write a list of them out
1390 to memory. See the 'iotrace' command for details. This is
1391 useful for testing device drivers since it can confirm that
1392 the driver behaves the same way before and after a code
1393 change. Currently this is supported on sandbox and arm. To
1394 add support for your architecture, add '#include <iotrace.h>'
1395 to the bottom of arch/<arch>/include/asm/io.h and test.
1397 Example output from the 'iotrace stats' command is below.
1398 Note that if the trace buffer is exhausted, the checksum will
1399 still continue to operate.
1402 Start: 10000000 (buffer start address)
1403 Size: 00010000 (buffer size)
1404 Offset: 00000120 (current buffer offset)
1405 Output: 10000120 (start + offset)
1406 Count: 00000018 (number of trace records)
1407 CRC32: 9526fb66 (CRC32 of all trace records)
1409 - Timestamp Support:
1411 When CONFIG_TIMESTAMP is selected, the timestamp
1412 (date and time) of an image is printed by image
1413 commands like bootm or iminfo. This option is
1414 automatically enabled when you select CONFIG_CMD_DATE .
1416 - Partition Labels (disklabels) Supported:
1417 Zero or more of the following:
1418 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1419 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1420 Intel architecture, USB sticks, etc.
1421 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1422 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1423 bootloader. Note 2TB partition limit; see
1425 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1427 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1428 CONFIG_CMD_SCSI) you must configure support for at
1429 least one non-MTD partition type as well.
1432 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1433 board configurations files but used nowhere!
1435 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1436 be performed by calling the function
1437 ide_set_reset(int reset)
1438 which has to be defined in a board specific file
1443 Set this to enable ATAPI support.
1448 Set this to enable support for disks larger than 137GB
1449 Also look at CONFIG_SYS_64BIT_LBA.
1450 Whithout these , LBA48 support uses 32bit variables and will 'only'
1451 support disks up to 2.1TB.
1453 CONFIG_SYS_64BIT_LBA:
1454 When enabled, makes the IDE subsystem use 64bit sector addresses.
1458 At the moment only there is only support for the
1459 SYM53C8XX SCSI controller; define
1460 CONFIG_SCSI_SYM53C8XX to enable it.
1462 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1463 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1464 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1465 maximum numbers of LUNs, SCSI ID's and target
1467 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1469 The environment variable 'scsidevs' is set to the number of
1470 SCSI devices found during the last scan.
1472 - NETWORK Support (PCI):
1474 Support for Intel 8254x/8257x gigabit chips.
1477 Utility code for direct access to the SPI bus on Intel 8257x.
1478 This does not do anything useful unless you set at least one
1479 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1481 CONFIG_E1000_SPI_GENERIC
1482 Allow generic access to the SPI bus on the Intel 8257x, for
1483 example with the "sspi" command.
1486 Management command for E1000 devices. When used on devices
1487 with SPI support you can reprogram the EEPROM from U-Boot.
1489 CONFIG_E1000_FALLBACK_MAC
1490 default MAC for empty EEPROM after production.
1493 Support for Intel 82557/82559/82559ER chips.
1494 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1495 write routine for first time initialisation.
1498 Support for Digital 2114x chips.
1499 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1500 modem chip initialisation (KS8761/QS6611).
1503 Support for National dp83815 chips.
1506 Support for National dp8382[01] gigabit chips.
1508 - NETWORK Support (other):
1510 CONFIG_DRIVER_AT91EMAC
1511 Support for AT91RM9200 EMAC.
1514 Define this to use reduced MII inteface
1516 CONFIG_DRIVER_AT91EMAC_QUIET
1517 If this defined, the driver is quiet.
1518 The driver doen't show link status messages.
1520 CONFIG_CALXEDA_XGMAC
1521 Support for the Calxeda XGMAC device
1524 Support for SMSC's LAN91C96 chips.
1526 CONFIG_LAN91C96_BASE
1527 Define this to hold the physical address
1528 of the LAN91C96's I/O space
1530 CONFIG_LAN91C96_USE_32_BIT
1531 Define this to enable 32 bit addressing
1534 Support for SMSC's LAN91C111 chip
1536 CONFIG_SMC91111_BASE
1537 Define this to hold the physical address
1538 of the device (I/O space)
1540 CONFIG_SMC_USE_32_BIT
1541 Define this if data bus is 32 bits
1543 CONFIG_SMC_USE_IOFUNCS
1544 Define this to use i/o functions instead of macros
1545 (some hardware wont work with macros)
1547 CONFIG_DRIVER_TI_EMAC
1548 Support for davinci emac
1550 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1551 Define this if you have more then 3 PHYs.
1554 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1556 CONFIG_FTGMAC100_EGIGA
1557 Define this to use GE link update with gigabit PHY.
1558 Define this if FTGMAC100 is connected to gigabit PHY.
1559 If your system has 10/100 PHY only, it might not occur
1560 wrong behavior. Because PHY usually return timeout or
1561 useless data when polling gigabit status and gigabit
1562 control registers. This behavior won't affect the
1563 correctnessof 10/100 link speed update.
1566 Support for SMSC's LAN911x and LAN921x chips
1569 Define this to hold the physical address
1570 of the device (I/O space)
1572 CONFIG_SMC911X_32_BIT
1573 Define this if data bus is 32 bits
1575 CONFIG_SMC911X_16_BIT
1576 Define this if data bus is 16 bits. If your processor
1577 automatically converts one 32 bit word to two 16 bit
1578 words you may also try CONFIG_SMC911X_32_BIT.
1581 Support for Renesas on-chip Ethernet controller
1583 CONFIG_SH_ETHER_USE_PORT
1584 Define the number of ports to be used
1586 CONFIG_SH_ETHER_PHY_ADDR
1587 Define the ETH PHY's address
1589 CONFIG_SH_ETHER_CACHE_WRITEBACK
1590 If this option is set, the driver enables cache flush.
1594 Support for PWM modul on the imx6.
1598 Support TPM devices.
1601 Support for i2c bus TPM devices. Only one device
1602 per system is supported at this time.
1604 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1605 Define the the i2c bus number for the TPM device
1607 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1608 Define the TPM's address on the i2c bus
1610 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1611 Define the burst count bytes upper limit
1613 CONFIG_TPM_ATMEL_TWI
1614 Support for Atmel TWI TPM device. Requires I2C support.
1617 Support for generic parallel port TPM devices. Only one device
1618 per system is supported at this time.
1620 CONFIG_TPM_TIS_BASE_ADDRESS
1621 Base address where the generic TPM device is mapped
1622 to. Contemporary x86 systems usually map it at
1626 Add tpm monitor functions.
1627 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1628 provides monitor access to authorized functions.
1631 Define this to enable the TPM support library which provides
1632 functional interfaces to some TPM commands.
1633 Requires support for a TPM device.
1635 CONFIG_TPM_AUTH_SESSIONS
1636 Define this to enable authorized functions in the TPM library.
1637 Requires CONFIG_TPM and CONFIG_SHA1.
1640 At the moment only the UHCI host controller is
1641 supported (PIP405, MIP405, MPC5200); define
1642 CONFIG_USB_UHCI to enable it.
1643 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1644 and define CONFIG_USB_STORAGE to enable the USB
1647 Supported are USB Keyboards and USB Floppy drives
1649 MPC5200 USB requires additional defines:
1651 for 528 MHz Clock: 0x0001bbbb
1655 for differential drivers: 0x00001000
1656 for single ended drivers: 0x00005000
1657 for differential drivers on PSC3: 0x00000100
1658 for single ended drivers on PSC3: 0x00004100
1659 CONFIG_SYS_USB_EVENT_POLL
1660 May be defined to allow interrupt polling
1661 instead of using asynchronous interrupts
1663 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1664 txfilltuning field in the EHCI controller on reset.
1666 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1667 HW module registers.
1670 Define the below if you wish to use the USB console.
1671 Once firmware is rebuilt from a serial console issue the
1672 command "setenv stdin usbtty; setenv stdout usbtty" and
1673 attach your USB cable. The Unix command "dmesg" should print
1674 it has found a new device. The environment variable usbtty
1675 can be set to gserial or cdc_acm to enable your device to
1676 appear to a USB host as a Linux gserial device or a
1677 Common Device Class Abstract Control Model serial device.
1678 If you select usbtty = gserial you should be able to enumerate
1680 # modprobe usbserial vendor=0xVendorID product=0xProductID
1681 else if using cdc_acm, simply setting the environment
1682 variable usbtty to be cdc_acm should suffice. The following
1683 might be defined in YourBoardName.h
1686 Define this to build a UDC device
1689 Define this to have a tty type of device available to
1690 talk to the UDC device
1693 Define this to enable the high speed support for usb
1694 device and usbtty. If this feature is enabled, a routine
1695 int is_usbd_high_speed(void)
1696 also needs to be defined by the driver to dynamically poll
1697 whether the enumeration has succeded at high speed or full
1700 CONFIG_SYS_CONSOLE_IS_IN_ENV
1701 Define this if you want stdin, stdout &/or stderr to
1705 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1706 Derive USB clock from external clock "blah"
1707 - CONFIG_SYS_USB_EXTC_CLK 0x02
1709 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1710 Derive USB clock from brgclk
1711 - CONFIG_SYS_USB_BRG_CLK 0x04
1713 If you have a USB-IF assigned VendorID then you may wish to
1714 define your own vendor specific values either in BoardName.h
1715 or directly in usbd_vendor_info.h. If you don't define
1716 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1717 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1718 should pretend to be a Linux device to it's target host.
1720 CONFIG_USBD_MANUFACTURER
1721 Define this string as the name of your company for
1722 - CONFIG_USBD_MANUFACTURER "my company"
1724 CONFIG_USBD_PRODUCT_NAME
1725 Define this string as the name of your product
1726 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1728 CONFIG_USBD_VENDORID
1729 Define this as your assigned Vendor ID from the USB
1730 Implementors Forum. This *must* be a genuine Vendor ID
1731 to avoid polluting the USB namespace.
1732 - CONFIG_USBD_VENDORID 0xFFFF
1734 CONFIG_USBD_PRODUCTID
1735 Define this as the unique Product ID
1737 - CONFIG_USBD_PRODUCTID 0xFFFF
1739 - ULPI Layer Support:
1740 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1741 the generic ULPI layer. The generic layer accesses the ULPI PHY
1742 via the platform viewport, so you need both the genric layer and
1743 the viewport enabled. Currently only Chipidea/ARC based
1744 viewport is supported.
1745 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1746 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1747 If your ULPI phy needs a different reference clock than the
1748 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1749 the appropriate value in Hz.
1752 The MMC controller on the Intel PXA is supported. To
1753 enable this define CONFIG_MMC. The MMC can be
1754 accessed from the boot prompt by mapping the device
1755 to physical memory similar to flash. Command line is
1756 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1757 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1760 Support for Renesas on-chip MMCIF controller
1762 CONFIG_SH_MMCIF_ADDR
1763 Define the base address of MMCIF registers
1766 Define the clock frequency for MMCIF
1769 Enable the generic MMC driver
1771 CONFIG_SUPPORT_EMMC_BOOT
1772 Enable some additional features of the eMMC boot partitions.
1774 CONFIG_SUPPORT_EMMC_RPMB
1775 Enable the commands for reading, writing and programming the
1776 key for the Replay Protection Memory Block partition in eMMC.
1778 - USB Device Firmware Update (DFU) class support:
1780 This enables the USB portion of the DFU USB class
1783 This enables the command "dfu" which is used to have
1784 U-Boot create a DFU class device via USB. This command
1785 requires that the "dfu_alt_info" environment variable be
1786 set and define the alt settings to expose to the host.
1789 This enables support for exposing (e)MMC devices via DFU.
1792 This enables support for exposing NAND devices via DFU.
1795 This enables support for exposing RAM via DFU.
1796 Note: DFU spec refer to non-volatile memory usage, but
1797 allow usages beyond the scope of spec - here RAM usage,
1798 one that would help mostly the developer.
1800 CONFIG_SYS_DFU_DATA_BUF_SIZE
1801 Dfu transfer uses a buffer before writing data to the
1802 raw storage device. Make the size (in bytes) of this buffer
1803 configurable. The size of this buffer is also configurable
1804 through the "dfu_bufsiz" environment variable.
1806 CONFIG_SYS_DFU_MAX_FILE_SIZE
1807 When updating files rather than the raw storage device,
1808 we use a static buffer to copy the file into and then write
1809 the buffer once we've been given the whole file. Define
1810 this to the maximum filesize (in bytes) for the buffer.
1811 Default is 4 MiB if undefined.
1813 DFU_DEFAULT_POLL_TIMEOUT
1814 Poll timeout [ms], is the timeout a device can send to the
1815 host. The host must wait for this timeout before sending
1816 a subsequent DFU_GET_STATUS request to the device.
1818 DFU_MANIFEST_POLL_TIMEOUT
1819 Poll timeout [ms], which the device sends to the host when
1820 entering dfuMANIFEST state. Host waits this timeout, before
1821 sending again an USB request to the device.
1823 - USB Device Android Fastboot support:
1825 This enables the command "fastboot" which enables the Android
1826 fastboot mode for the platform's USB device. Fastboot is a USB
1827 protocol for downloading images, flashing and device control
1828 used on Android devices.
1829 See doc/README.android-fastboot for more information.
1831 CONFIG_ANDROID_BOOT_IMAGE
1832 This enables support for booting images which use the Android
1833 image format header.
1835 CONFIG_USB_FASTBOOT_BUF_ADDR
1836 The fastboot protocol requires a large memory buffer for
1837 downloads. Define this to the starting RAM address to use for
1840 CONFIG_USB_FASTBOOT_BUF_SIZE
1841 The fastboot protocol requires a large memory buffer for
1842 downloads. This buffer should be as large as possible for a
1843 platform. Define this to the size available RAM for fastboot.
1845 CONFIG_FASTBOOT_FLASH
1846 The fastboot protocol includes a "flash" command for writing
1847 the downloaded image to a non-volatile storage device. Define
1848 this to enable the "fastboot flash" command.
1850 CONFIG_FASTBOOT_FLASH_MMC_DEV
1851 The fastboot "flash" command requires additional information
1852 regarding the non-volatile storage device. Define this to
1853 the eMMC device that fastboot should use to store the image.
1855 CONFIG_FASTBOOT_GPT_NAME
1856 The fastboot "flash" command supports writing the downloaded
1857 image to the Protective MBR and the Primary GUID Partition
1858 Table. (Additionally, this downloaded image is post-processed
1859 to generate and write the Backup GUID Partition Table.)
1860 This occurs when the specified "partition name" on the
1861 "fastboot flash" command line matches this value.
1862 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1864 - Journaling Flash filesystem support:
1865 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1866 CONFIG_JFFS2_NAND_DEV
1867 Define these for a default partition on a NAND device
1869 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1870 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1871 Define these for a default partition on a NOR device
1873 CONFIG_SYS_JFFS_CUSTOM_PART
1874 Define this to create an own partition. You have to provide a
1875 function struct part_info* jffs2_part_info(int part_num)
1877 If you define only one JFFS2 partition you may also want to
1878 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1879 to disable the command chpart. This is the default when you
1880 have not defined a custom partition
1882 - FAT(File Allocation Table) filesystem write function support:
1885 Define this to enable support for saving memory data as a
1886 file in FAT formatted partition.
1888 This will also enable the command "fatwrite" enabling the
1889 user to write files to FAT.
1891 CBFS (Coreboot Filesystem) support
1894 Define this to enable support for reading from a Coreboot
1895 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1898 - FAT(File Allocation Table) filesystem cluster size:
1899 CONFIG_FS_FAT_MAX_CLUSTSIZE
1901 Define the max cluster size for fat operations else
1902 a default value of 65536 will be defined.
1907 Define this to enable standard (PC-Style) keyboard
1911 Standard PC keyboard driver with US (is default) and
1912 GERMAN key layout (switch via environment 'keymap=de') support.
1913 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1914 for cfb_console. Supports cursor blinking.
1917 Enables a Chrome OS keyboard using the CROS_EC interface.
1918 This uses CROS_EC to communicate with a second microcontroller
1919 which provides key scans on request.
1924 Define this to enable video support (for output to
1927 CONFIG_VIDEO_CT69000
1929 Enable Chips & Technologies 69000 Video chip
1931 CONFIG_VIDEO_SMI_LYNXEM
1932 Enable Silicon Motion SMI 712/710/810 Video chip. The
1933 video output is selected via environment 'videoout'
1934 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1937 For the CT69000 and SMI_LYNXEM drivers, videomode is
1938 selected via environment 'videomode'. Two different ways
1940 - "videomode=num" 'num' is a standard LiLo mode numbers.
1941 Following standard modes are supported (* is default):
1943 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1944 -------------+---------------------------------------------
1945 8 bits | 0x301* 0x303 0x305 0x161 0x307
1946 15 bits | 0x310 0x313 0x316 0x162 0x319
1947 16 bits | 0x311 0x314 0x317 0x163 0x31A
1948 24 bits | 0x312 0x315 0x318 ? 0x31B
1949 -------------+---------------------------------------------
1950 (i.e. setenv videomode 317; saveenv; reset;)
1952 - "videomode=bootargs" all the video parameters are parsed
1953 from the bootargs. (See drivers/video/videomodes.c)
1956 CONFIG_VIDEO_SED13806
1957 Enable Epson SED13806 driver. This driver supports 8bpp
1958 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1959 or CONFIG_VIDEO_SED13806_16BPP
1962 Enable the Freescale DIU video driver. Reference boards for
1963 SOCs that have a DIU should define this macro to enable DIU
1964 support, and should also define these other macros:
1970 CONFIG_VIDEO_SW_CURSOR
1971 CONFIG_VGA_AS_SINGLE_DEVICE
1973 CONFIG_VIDEO_BMP_LOGO
1975 The DIU driver will look for the 'video-mode' environment
1976 variable, and if defined, enable the DIU as a console during
1977 boot. See the documentation file README.video for a
1978 description of this variable.
1982 Enable the VGA video / BIOS for x86. The alternative if you
1983 are using coreboot is to use the coreboot frame buffer
1990 Define this to enable a custom keyboard support.
1991 This simply calls drv_keyboard_init() which must be
1992 defined in your board-specific files.
1993 The only board using this so far is RBC823.
1995 - LCD Support: CONFIG_LCD
1997 Define this to enable LCD support (for output to LCD
1998 display); also select one of the supported displays
1999 by defining one of these:
2003 HITACHI TX09D70VM1CCA, 3.5", 240x320.
2005 CONFIG_NEC_NL6448AC33:
2007 NEC NL6448AC33-18. Active, color, single scan.
2009 CONFIG_NEC_NL6448BC20
2011 NEC NL6448BC20-08. 6.5", 640x480.
2012 Active, color, single scan.
2014 CONFIG_NEC_NL6448BC33_54
2016 NEC NL6448BC33-54. 10.4", 640x480.
2017 Active, color, single scan.
2021 Sharp 320x240. Active, color, single scan.
2022 It isn't 16x9, and I am not sure what it is.
2024 CONFIG_SHARP_LQ64D341
2026 Sharp LQ64D341 display, 640x480.
2027 Active, color, single scan.
2031 HLD1045 display, 640x480.
2032 Active, color, single scan.
2036 Optrex CBL50840-2 NF-FW 99 22 M5
2038 Hitachi LMG6912RPFC-00T
2042 320x240. Black & white.
2044 Normally display is black on white background; define
2045 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
2047 CONFIG_LCD_ALIGNMENT
2049 Normally the LCD is page-aligned (typically 4KB). If this is
2050 defined then the LCD will be aligned to this value instead.
2051 For ARM it is sometimes useful to use MMU_SECTION_SIZE
2052 here, since it is cheaper to change data cache settings on
2053 a per-section basis.
2055 CONFIG_CONSOLE_SCROLL_LINES
2057 When the console need to be scrolled, this is the number of
2058 lines to scroll by. It defaults to 1. Increasing this makes
2059 the console jump but can help speed up operation when scrolling
2064 Support drawing of RLE8-compressed bitmaps on the LCD.
2068 Enables an 'i2c edid' command which can read EDID
2069 information over I2C from an attached LCD display.
2071 - Splash Screen Support: CONFIG_SPLASH_SCREEN
2073 If this option is set, the environment is checked for
2074 a variable "splashimage". If found, the usual display
2075 of logo, copyright and system information on the LCD
2076 is suppressed and the BMP image at the address
2077 specified in "splashimage" is loaded instead. The
2078 console is redirected to the "nulldev", too. This
2079 allows for a "silent" boot where a splash screen is
2080 loaded very quickly after power-on.
2082 CONFIG_SPLASHIMAGE_GUARD
2084 If this option is set, then U-Boot will prevent the environment
2085 variable "splashimage" from being set to a problematic address
2086 (see README.displaying-bmps).
2087 This option is useful for targets where, due to alignment
2088 restrictions, an improperly aligned BMP image will cause a data
2089 abort. If you think you will not have problems with unaligned
2090 accesses (for example because your toolchain prevents them)
2091 there is no need to set this option.
2093 CONFIG_SPLASH_SCREEN_ALIGN
2095 If this option is set the splash image can be freely positioned
2096 on the screen. Environment variable "splashpos" specifies the
2097 position as "x,y". If a positive number is given it is used as
2098 number of pixel from left/top. If a negative number is given it
2099 is used as number of pixel from right/bottom. You can also
2100 specify 'm' for centering the image.
2103 setenv splashpos m,m
2104 => image at center of screen
2106 setenv splashpos 30,20
2107 => image at x = 30 and y = 20
2109 setenv splashpos -10,m
2110 => vertically centered image
2111 at x = dspWidth - bmpWidth - 9
2113 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2115 If this option is set, additionally to standard BMP
2116 images, gzipped BMP images can be displayed via the
2117 splashscreen support or the bmp command.
2119 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2121 If this option is set, 8-bit RLE compressed BMP images
2122 can be displayed via the splashscreen support or the
2125 - Do compressing for memory range:
2128 If this option is set, it would use zlib deflate method
2129 to compress the specified memory at its best effort.
2131 - Compression support:
2134 Enabled by default to support gzip compressed images.
2138 If this option is set, support for bzip2 compressed
2139 images is included. If not, only uncompressed and gzip
2140 compressed images are supported.
2142 NOTE: the bzip2 algorithm requires a lot of RAM, so
2143 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2148 If this option is set, support for lzma compressed
2151 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2152 requires an amount of dynamic memory that is given by the
2155 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2157 Where lc and lp stand for, respectively, Literal context bits
2158 and Literal pos bits.
2160 This value is upper-bounded by 14MB in the worst case. Anyway,
2161 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2162 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2163 a very small buffer.
2165 Use the lzmainfo tool to determinate the lc and lp values and
2166 then calculate the amount of needed dynamic memory (ensuring
2167 the appropriate CONFIG_SYS_MALLOC_LEN value).
2171 If this option is set, support for LZO compressed images
2177 The address of PHY on MII bus.
2179 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2181 The clock frequency of the MII bus
2185 If this option is set, support for speed/duplex
2186 detection of gigabit PHY is included.
2188 CONFIG_PHY_RESET_DELAY
2190 Some PHY like Intel LXT971A need extra delay after
2191 reset before any MII register access is possible.
2192 For such PHY, set this option to the usec delay
2193 required. (minimum 300usec for LXT971A)
2195 CONFIG_PHY_CMD_DELAY (ppc4xx)
2197 Some PHY like Intel LXT971A need extra delay after
2198 command issued before MII status register can be read
2208 Define a default value for Ethernet address to use
2209 for the respective Ethernet interface, in case this
2210 is not determined automatically.
2215 Define a default value for the IP address to use for
2216 the default Ethernet interface, in case this is not
2217 determined through e.g. bootp.
2218 (Environment variable "ipaddr")
2220 - Server IP address:
2223 Defines a default value for the IP address of a TFTP
2224 server to contact when using the "tftboot" command.
2225 (Environment variable "serverip")
2227 CONFIG_KEEP_SERVERADDR
2229 Keeps the server's MAC address, in the env 'serveraddr'
2230 for passing to bootargs (like Linux's netconsole option)
2232 - Gateway IP address:
2235 Defines a default value for the IP address of the
2236 default router where packets to other networks are
2238 (Environment variable "gatewayip")
2243 Defines a default value for the subnet mask (or
2244 routing prefix) which is used to determine if an IP
2245 address belongs to the local subnet or needs to be
2246 forwarded through a router.
2247 (Environment variable "netmask")
2249 - Multicast TFTP Mode:
2252 Defines whether you want to support multicast TFTP as per
2253 rfc-2090; for example to work with atftp. Lets lots of targets
2254 tftp down the same boot image concurrently. Note: the Ethernet
2255 driver in use must provide a function: mcast() to join/leave a
2258 - BOOTP Recovery Mode:
2259 CONFIG_BOOTP_RANDOM_DELAY
2261 If you have many targets in a network that try to
2262 boot using BOOTP, you may want to avoid that all
2263 systems send out BOOTP requests at precisely the same
2264 moment (which would happen for instance at recovery
2265 from a power failure, when all systems will try to
2266 boot, thus flooding the BOOTP server. Defining
2267 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2268 inserted before sending out BOOTP requests. The
2269 following delays are inserted then:
2271 1st BOOTP request: delay 0 ... 1 sec
2272 2nd BOOTP request: delay 0 ... 2 sec
2273 3rd BOOTP request: delay 0 ... 4 sec
2275 BOOTP requests: delay 0 ... 8 sec
2277 CONFIG_BOOTP_ID_CACHE_SIZE
2279 BOOTP packets are uniquely identified using a 32-bit ID. The
2280 server will copy the ID from client requests to responses and
2281 U-Boot will use this to determine if it is the destination of
2282 an incoming response. Some servers will check that addresses
2283 aren't in use before handing them out (usually using an ARP
2284 ping) and therefore take up to a few hundred milliseconds to
2285 respond. Network congestion may also influence the time it
2286 takes for a response to make it back to the client. If that
2287 time is too long, U-Boot will retransmit requests. In order
2288 to allow earlier responses to still be accepted after these
2289 retransmissions, U-Boot's BOOTP client keeps a small cache of
2290 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2291 cache. The default is to keep IDs for up to four outstanding
2292 requests. Increasing this will allow U-Boot to accept offers
2293 from a BOOTP client in networks with unusually high latency.
2295 - DHCP Advanced Options:
2296 You can fine tune the DHCP functionality by defining
2297 CONFIG_BOOTP_* symbols:
2299 CONFIG_BOOTP_SUBNETMASK
2300 CONFIG_BOOTP_GATEWAY
2301 CONFIG_BOOTP_HOSTNAME
2302 CONFIG_BOOTP_NISDOMAIN
2303 CONFIG_BOOTP_BOOTPATH
2304 CONFIG_BOOTP_BOOTFILESIZE
2307 CONFIG_BOOTP_SEND_HOSTNAME
2308 CONFIG_BOOTP_NTPSERVER
2309 CONFIG_BOOTP_TIMEOFFSET
2310 CONFIG_BOOTP_VENDOREX
2311 CONFIG_BOOTP_MAY_FAIL
2313 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2314 environment variable, not the BOOTP server.
2316 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2317 after the configured retry count, the call will fail
2318 instead of starting over. This can be used to fail over
2319 to Link-local IP address configuration if the DHCP server
2322 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2323 serverip from a DHCP server, it is possible that more
2324 than one DNS serverip is offered to the client.
2325 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2326 serverip will be stored in the additional environment
2327 variable "dnsip2". The first DNS serverip is always
2328 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2331 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2332 to do a dynamic update of a DNS server. To do this, they
2333 need the hostname of the DHCP requester.
2334 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2335 of the "hostname" environment variable is passed as
2336 option 12 to the DHCP server.
2338 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2340 A 32bit value in microseconds for a delay between
2341 receiving a "DHCP Offer" and sending the "DHCP Request".
2342 This fixes a problem with certain DHCP servers that don't
2343 respond 100% of the time to a "DHCP request". E.g. On an
2344 AT91RM9200 processor running at 180MHz, this delay needed
2345 to be *at least* 15,000 usec before a Windows Server 2003
2346 DHCP server would reply 100% of the time. I recommend at
2347 least 50,000 usec to be safe. The alternative is to hope
2348 that one of the retries will be successful but note that
2349 the DHCP timeout and retry process takes a longer than
2352 - Link-local IP address negotiation:
2353 Negotiate with other link-local clients on the local network
2354 for an address that doesn't require explicit configuration.
2355 This is especially useful if a DHCP server cannot be guaranteed
2356 to exist in all environments that the device must operate.
2358 See doc/README.link-local for more information.
2361 CONFIG_CDP_DEVICE_ID
2363 The device id used in CDP trigger frames.
2365 CONFIG_CDP_DEVICE_ID_PREFIX
2367 A two character string which is prefixed to the MAC address
2372 A printf format string which contains the ascii name of
2373 the port. Normally is set to "eth%d" which sets
2374 eth0 for the first Ethernet, eth1 for the second etc.
2376 CONFIG_CDP_CAPABILITIES
2378 A 32bit integer which indicates the device capabilities;
2379 0x00000010 for a normal host which does not forwards.
2383 An ascii string containing the version of the software.
2387 An ascii string containing the name of the platform.
2391 A 32bit integer sent on the trigger.
2393 CONFIG_CDP_POWER_CONSUMPTION
2395 A 16bit integer containing the power consumption of the
2396 device in .1 of milliwatts.
2398 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2400 A byte containing the id of the VLAN.
2402 - Status LED: CONFIG_STATUS_LED
2404 Several configurations allow to display the current
2405 status using a LED. For instance, the LED will blink
2406 fast while running U-Boot code, stop blinking as
2407 soon as a reply to a BOOTP request was received, and
2408 start blinking slow once the Linux kernel is running
2409 (supported by a status LED driver in the Linux
2410 kernel). Defining CONFIG_STATUS_LED enables this
2416 The status LED can be connected to a GPIO pin.
2417 In such cases, the gpio_led driver can be used as a
2418 status LED backend implementation. Define CONFIG_GPIO_LED
2419 to include the gpio_led driver in the U-Boot binary.
2421 CONFIG_GPIO_LED_INVERTED_TABLE
2422 Some GPIO connected LEDs may have inverted polarity in which
2423 case the GPIO high value corresponds to LED off state and
2424 GPIO low value corresponds to LED on state.
2425 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2426 with a list of GPIO LEDs that have inverted polarity.
2428 - CAN Support: CONFIG_CAN_DRIVER
2430 Defining CONFIG_CAN_DRIVER enables CAN driver support
2431 on those systems that support this (optional)
2432 feature, like the TQM8xxL modules.
2434 - I2C Support: CONFIG_SYS_I2C
2436 This enable the NEW i2c subsystem, and will allow you to use
2437 i2c commands at the u-boot command line (as long as you set
2438 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2439 based realtime clock chips or other i2c devices. See
2440 common/cmd_i2c.c for a description of the command line
2443 ported i2c driver to the new framework:
2444 - drivers/i2c/soft_i2c.c:
2445 - activate first bus with CONFIG_SYS_I2C_SOFT define
2446 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2447 for defining speed and slave address
2448 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2449 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2450 for defining speed and slave address
2451 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2452 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2453 for defining speed and slave address
2454 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2455 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2456 for defining speed and slave address
2458 - drivers/i2c/fsl_i2c.c:
2459 - activate i2c driver with CONFIG_SYS_I2C_FSL
2460 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2461 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2462 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2464 - If your board supports a second fsl i2c bus, define
2465 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2466 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2467 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2470 - drivers/i2c/tegra_i2c.c:
2471 - activate this driver with CONFIG_SYS_I2C_TEGRA
2472 - This driver adds 4 i2c buses with a fix speed from
2473 100000 and the slave addr 0!
2475 - drivers/i2c/ppc4xx_i2c.c
2476 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2477 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2478 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2480 - drivers/i2c/i2c_mxc.c
2481 - activate this driver with CONFIG_SYS_I2C_MXC
2482 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2483 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2484 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2485 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2486 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2487 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2488 If those defines are not set, default value is 100000
2489 for speed, and 0 for slave.
2491 - drivers/i2c/rcar_i2c.c:
2492 - activate this driver with CONFIG_SYS_I2C_RCAR
2493 - This driver adds 4 i2c buses
2495 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2496 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2497 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2498 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2499 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2500 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2501 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2502 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2503 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2505 - drivers/i2c/sh_i2c.c:
2506 - activate this driver with CONFIG_SYS_I2C_SH
2507 - This driver adds from 2 to 5 i2c buses
2509 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2510 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2511 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2512 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2513 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2514 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2515 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2516 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2517 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2518 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2519 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2520 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2521 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2523 - drivers/i2c/omap24xx_i2c.c
2524 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2525 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2526 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2527 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2528 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2529 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2530 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2531 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2532 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2533 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2534 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2536 - drivers/i2c/zynq_i2c.c
2537 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2538 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2539 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2541 - drivers/i2c/s3c24x0_i2c.c:
2542 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2543 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2544 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2545 with a fix speed from 100000 and the slave addr 0!
2547 - drivers/i2c/ihs_i2c.c
2548 - activate this driver with CONFIG_SYS_I2C_IHS
2549 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2550 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2551 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2552 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2553 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2554 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2555 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2556 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2557 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2558 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2559 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2560 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2564 CONFIG_SYS_NUM_I2C_BUSES
2565 Hold the number of i2c buses you want to use. If you
2566 don't use/have i2c muxes on your i2c bus, this
2567 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2570 CONFIG_SYS_I2C_DIRECT_BUS
2571 define this, if you don't use i2c muxes on your hardware.
2572 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2575 CONFIG_SYS_I2C_MAX_HOPS
2576 define how many muxes are maximal consecutively connected
2577 on one i2c bus. If you not use i2c muxes, omit this
2580 CONFIG_SYS_I2C_BUSES
2581 hold a list of buses you want to use, only used if
2582 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2583 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2584 CONFIG_SYS_NUM_I2C_BUSES = 9:
2586 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2587 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2588 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2589 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2590 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2591 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2592 {1, {I2C_NULL_HOP}}, \
2593 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2594 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2598 bus 0 on adapter 0 without a mux
2599 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2600 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2601 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2602 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2603 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2604 bus 6 on adapter 1 without a mux
2605 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2606 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2608 If you do not have i2c muxes on your board, omit this define.
2610 - Legacy I2C Support: CONFIG_HARD_I2C
2612 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2613 provides the following compelling advantages:
2615 - more than one i2c adapter is usable
2616 - approved multibus support
2617 - better i2c mux support
2619 ** Please consider updating your I2C driver now. **
2621 These enable legacy I2C serial bus commands. Defining
2622 CONFIG_HARD_I2C will include the appropriate I2C driver
2623 for the selected CPU.
2625 This will allow you to use i2c commands at the u-boot
2626 command line (as long as you set CONFIG_CMD_I2C in
2627 CONFIG_COMMANDS) and communicate with i2c based realtime
2628 clock chips. See common/cmd_i2c.c for a description of the
2629 command line interface.
2631 CONFIG_HARD_I2C selects a hardware I2C controller.
2633 There are several other quantities that must also be
2634 defined when you define CONFIG_HARD_I2C.
2636 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2637 to be the frequency (in Hz) at which you wish your i2c bus
2638 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2639 the CPU's i2c node address).
2641 Now, the u-boot i2c code for the mpc8xx
2642 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2643 and so its address should therefore be cleared to 0 (See,
2644 eg, MPC823e User's Manual p.16-473). So, set
2645 CONFIG_SYS_I2C_SLAVE to 0.
2647 CONFIG_SYS_I2C_INIT_MPC5XXX
2649 When a board is reset during an i2c bus transfer
2650 chips might think that the current transfer is still
2651 in progress. Reset the slave devices by sending start
2652 commands until the slave device responds.
2654 That's all that's required for CONFIG_HARD_I2C.
2656 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2657 then the following macros need to be defined (examples are
2658 from include/configs/lwmon.h):
2662 (Optional). Any commands necessary to enable the I2C
2663 controller or configure ports.
2665 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2669 (Only for MPC8260 CPU). The I/O port to use (the code
2670 assumes both bits are on the same port). Valid values
2671 are 0..3 for ports A..D.
2675 The code necessary to make the I2C data line active
2676 (driven). If the data line is open collector, this
2679 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2683 The code necessary to make the I2C data line tri-stated
2684 (inactive). If the data line is open collector, this
2687 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2691 Code that returns true if the I2C data line is high,
2694 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2698 If <bit> is true, sets the I2C data line high. If it
2699 is false, it clears it (low).
2701 eg: #define I2C_SDA(bit) \
2702 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2703 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2707 If <bit> is true, sets the I2C clock line high. If it
2708 is false, it clears it (low).
2710 eg: #define I2C_SCL(bit) \
2711 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2712 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2716 This delay is invoked four times per clock cycle so this
2717 controls the rate of data transfer. The data rate thus
2718 is 1 / (I2C_DELAY * 4). Often defined to be something
2721 #define I2C_DELAY udelay(2)
2723 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2725 If your arch supports the generic GPIO framework (asm/gpio.h),
2726 then you may alternatively define the two GPIOs that are to be
2727 used as SCL / SDA. Any of the previous I2C_xxx macros will
2728 have GPIO-based defaults assigned to them as appropriate.
2730 You should define these to the GPIO value as given directly to
2731 the generic GPIO functions.
2733 CONFIG_SYS_I2C_INIT_BOARD
2735 When a board is reset during an i2c bus transfer
2736 chips might think that the current transfer is still
2737 in progress. On some boards it is possible to access
2738 the i2c SCLK line directly, either by using the
2739 processor pin as a GPIO or by having a second pin
2740 connected to the bus. If this option is defined a
2741 custom i2c_init_board() routine in boards/xxx/board.c
2742 is run early in the boot sequence.
2744 CONFIG_SYS_I2C_BOARD_LATE_INIT
2746 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2747 defined a custom i2c_board_late_init() routine in
2748 boards/xxx/board.c is run AFTER the operations in i2c_init()
2749 is completed. This callpoint can be used to unreset i2c bus
2750 using CPU i2c controller register accesses for CPUs whose i2c
2751 controller provide such a method. It is called at the end of
2752 i2c_init() to allow i2c_init operations to setup the i2c bus
2753 controller on the CPU (e.g. setting bus speed & slave address).
2755 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2757 This option enables configuration of bi_iic_fast[] flags
2758 in u-boot bd_info structure based on u-boot environment
2759 variable "i2cfast". (see also i2cfast)
2761 CONFIG_I2C_MULTI_BUS
2763 This option allows the use of multiple I2C buses, each of which
2764 must have a controller. At any point in time, only one bus is
2765 active. To switch to a different bus, use the 'i2c dev' command.
2766 Note that bus numbering is zero-based.
2768 CONFIG_SYS_I2C_NOPROBES
2770 This option specifies a list of I2C devices that will be skipped
2771 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2772 is set, specify a list of bus-device pairs. Otherwise, specify
2773 a 1D array of device addresses
2776 #undef CONFIG_I2C_MULTI_BUS
2777 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2779 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2781 #define CONFIG_I2C_MULTI_BUS
2782 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2784 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2786 CONFIG_SYS_SPD_BUS_NUM
2788 If defined, then this indicates the I2C bus number for DDR SPD.
2789 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2791 CONFIG_SYS_RTC_BUS_NUM
2793 If defined, then this indicates the I2C bus number for the RTC.
2794 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2796 CONFIG_SYS_DTT_BUS_NUM
2798 If defined, then this indicates the I2C bus number for the DTT.
2799 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2801 CONFIG_SYS_I2C_DTT_ADDR:
2803 If defined, specifies the I2C address of the DTT device.
2804 If not defined, then U-Boot uses predefined value for
2805 specified DTT device.
2807 CONFIG_SOFT_I2C_READ_REPEATED_START
2809 defining this will force the i2c_read() function in
2810 the soft_i2c driver to perform an I2C repeated start
2811 between writing the address pointer and reading the
2812 data. If this define is omitted the default behaviour
2813 of doing a stop-start sequence will be used. Most I2C
2814 devices can use either method, but some require one or
2817 - SPI Support: CONFIG_SPI
2819 Enables SPI driver (so far only tested with
2820 SPI EEPROM, also an instance works with Crystal A/D and
2821 D/As on the SACSng board)
2825 Enables the driver for SPI controller on SuperH. Currently
2826 only SH7757 is supported.
2830 Enables extended (16-bit) SPI EEPROM addressing.
2831 (symmetrical to CONFIG_I2C_X)
2835 Enables a software (bit-bang) SPI driver rather than
2836 using hardware support. This is a general purpose
2837 driver that only requires three general I/O port pins
2838 (two outputs, one input) to function. If this is
2839 defined, the board configuration must define several
2840 SPI configuration items (port pins to use, etc). For
2841 an example, see include/configs/sacsng.h.
2845 Enables a hardware SPI driver for general-purpose reads
2846 and writes. As with CONFIG_SOFT_SPI, the board configuration
2847 must define a list of chip-select function pointers.
2848 Currently supported on some MPC8xxx processors. For an
2849 example, see include/configs/mpc8349emds.h.
2853 Enables the driver for the SPI controllers on i.MX and MXC
2854 SoCs. Currently i.MX31/35/51 are supported.
2856 CONFIG_SYS_SPI_MXC_WAIT
2857 Timeout for waiting until spi transfer completed.
2858 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2860 - FPGA Support: CONFIG_FPGA
2862 Enables FPGA subsystem.
2864 CONFIG_FPGA_<vendor>
2866 Enables support for specific chip vendors.
2869 CONFIG_FPGA_<family>
2871 Enables support for FPGA family.
2872 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2876 Specify the number of FPGA devices to support.
2878 CONFIG_CMD_FPGA_LOADMK
2880 Enable support for fpga loadmk command
2882 CONFIG_CMD_FPGA_LOADP
2884 Enable support for fpga loadp command - load partial bitstream
2886 CONFIG_CMD_FPGA_LOADBP
2888 Enable support for fpga loadbp command - load partial bitstream
2891 CONFIG_SYS_FPGA_PROG_FEEDBACK
2893 Enable printing of hash marks during FPGA configuration.
2895 CONFIG_SYS_FPGA_CHECK_BUSY
2897 Enable checks on FPGA configuration interface busy
2898 status by the configuration function. This option
2899 will require a board or device specific function to
2904 If defined, a function that provides delays in the FPGA
2905 configuration driver.
2907 CONFIG_SYS_FPGA_CHECK_CTRLC
2908 Allow Control-C to interrupt FPGA configuration
2910 CONFIG_SYS_FPGA_CHECK_ERROR
2912 Check for configuration errors during FPGA bitfile
2913 loading. For example, abort during Virtex II
2914 configuration if the INIT_B line goes low (which
2915 indicated a CRC error).
2917 CONFIG_SYS_FPGA_WAIT_INIT
2919 Maximum time to wait for the INIT_B line to de-assert
2920 after PROB_B has been de-asserted during a Virtex II
2921 FPGA configuration sequence. The default time is 500
2924 CONFIG_SYS_FPGA_WAIT_BUSY
2926 Maximum time to wait for BUSY to de-assert during
2927 Virtex II FPGA configuration. The default is 5 ms.
2929 CONFIG_SYS_FPGA_WAIT_CONFIG
2931 Time to wait after FPGA configuration. The default is
2934 - Configuration Management:
2937 Some SoCs need special image types (e.g. U-Boot binary
2938 with a special header) as build targets. By defining
2939 CONFIG_BUILD_TARGET in the SoC / board header, this
2940 special image will be automatically built upon calling
2945 If defined, this string will be added to the U-Boot
2946 version information (U_BOOT_VERSION)
2948 - Vendor Parameter Protection:
2950 U-Boot considers the values of the environment
2951 variables "serial#" (Board Serial Number) and
2952 "ethaddr" (Ethernet Address) to be parameters that
2953 are set once by the board vendor / manufacturer, and
2954 protects these variables from casual modification by
2955 the user. Once set, these variables are read-only,
2956 and write or delete attempts are rejected. You can
2957 change this behaviour:
2959 If CONFIG_ENV_OVERWRITE is #defined in your config
2960 file, the write protection for vendor parameters is
2961 completely disabled. Anybody can change or delete
2964 Alternatively, if you #define _both_ CONFIG_ETHADDR
2965 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2966 Ethernet address is installed in the environment,
2967 which can be changed exactly ONCE by the user. [The
2968 serial# is unaffected by this, i. e. it remains
2971 The same can be accomplished in a more flexible way
2972 for any variable by configuring the type of access
2973 to allow for those variables in the ".flags" variable
2974 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2979 Define this variable to enable the reservation of
2980 "protected RAM", i. e. RAM which is not overwritten
2981 by U-Boot. Define CONFIG_PRAM to hold the number of
2982 kB you want to reserve for pRAM. You can overwrite
2983 this default value by defining an environment
2984 variable "pram" to the number of kB you want to
2985 reserve. Note that the board info structure will
2986 still show the full amount of RAM. If pRAM is
2987 reserved, a new environment variable "mem" will
2988 automatically be defined to hold the amount of
2989 remaining RAM in a form that can be passed as boot
2990 argument to Linux, for instance like that:
2992 setenv bootargs ... mem=\${mem}
2995 This way you can tell Linux not to use this memory,
2996 either, which results in a memory region that will
2997 not be affected by reboots.
2999 *WARNING* If your board configuration uses automatic
3000 detection of the RAM size, you must make sure that
3001 this memory test is non-destructive. So far, the
3002 following board configurations are known to be
3005 IVMS8, IVML24, SPD8xx, TQM8xxL,
3006 HERMES, IP860, RPXlite, LWMON,
3009 - Access to physical memory region (> 4GB)
3010 Some basic support is provided for operations on memory not
3011 normally accessible to U-Boot - e.g. some architectures
3012 support access to more than 4GB of memory on 32-bit
3013 machines using physical address extension or similar.
3014 Define CONFIG_PHYSMEM to access this basic support, which
3015 currently only supports clearing the memory.
3020 Define this variable to stop the system in case of a
3021 fatal error, so that you have to reset it manually.
3022 This is probably NOT a good idea for an embedded
3023 system where you want the system to reboot
3024 automatically as fast as possible, but it may be
3025 useful during development since you can try to debug
3026 the conditions that lead to the situation.
3028 CONFIG_NET_RETRY_COUNT
3030 This variable defines the number of retries for
3031 network operations like ARP, RARP, TFTP, or BOOTP
3032 before giving up the operation. If not defined, a
3033 default value of 5 is used.
3037 Timeout waiting for an ARP reply in milliseconds.
3041 Timeout in milliseconds used in NFS protocol.
3042 If you encounter "ERROR: Cannot umount" in nfs command,
3043 try longer timeout such as
3044 #define CONFIG_NFS_TIMEOUT 10000UL
3046 - Command Interpreter:
3047 CONFIG_AUTO_COMPLETE
3049 Enable auto completion of commands using TAB.
3051 CONFIG_SYS_PROMPT_HUSH_PS2
3053 This defines the secondary prompt string, which is
3054 printed when the command interpreter needs more input
3055 to complete a command. Usually "> ".
3059 In the current implementation, the local variables
3060 space and global environment variables space are
3061 separated. Local variables are those you define by
3062 simply typing `name=value'. To access a local
3063 variable later on, you have write `$name' or
3064 `${name}'; to execute the contents of a variable
3065 directly type `$name' at the command prompt.
3067 Global environment variables are those you use
3068 setenv/printenv to work with. To run a command stored
3069 in such a variable, you need to use the run command,
3070 and you must not use the '$' sign to access them.
3072 To store commands and special characters in a
3073 variable, please use double quotation marks
3074 surrounding the whole text of the variable, instead
3075 of the backslashes before semicolons and special
3078 - Command Line Editing and History:
3079 CONFIG_CMDLINE_EDITING
3081 Enable editing and History functions for interactive
3082 command line input operations
3084 - Default Environment:
3085 CONFIG_EXTRA_ENV_SETTINGS
3087 Define this to contain any number of null terminated
3088 strings (variable = value pairs) that will be part of
3089 the default environment compiled into the boot image.
3091 For example, place something like this in your
3092 board's config file:
3094 #define CONFIG_EXTRA_ENV_SETTINGS \
3098 Warning: This method is based on knowledge about the
3099 internal format how the environment is stored by the
3100 U-Boot code. This is NOT an official, exported
3101 interface! Although it is unlikely that this format
3102 will change soon, there is no guarantee either.
3103 You better know what you are doing here.
3105 Note: overly (ab)use of the default environment is
3106 discouraged. Make sure to check other ways to preset
3107 the environment like the "source" command or the
3110 CONFIG_ENV_VARS_UBOOT_CONFIG
3112 Define this in order to add variables describing the
3113 U-Boot build configuration to the default environment.
3114 These will be named arch, cpu, board, vendor, and soc.
3116 Enabling this option will cause the following to be defined:
3124 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3126 Define this in order to add variables describing certain
3127 run-time determined information about the hardware to the
3128 environment. These will be named board_name, board_rev.
3130 CONFIG_DELAY_ENVIRONMENT
3132 Normally the environment is loaded when the board is
3133 initialised so that it is available to U-Boot. This inhibits
3134 that so that the environment is not available until
3135 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3136 this is instead controlled by the value of
3137 /config/load-environment.
3139 - DataFlash Support:
3140 CONFIG_HAS_DATAFLASH
3142 Defining this option enables DataFlash features and
3143 allows to read/write in Dataflash via the standard
3146 - Serial Flash support
3149 Defining this option enables SPI flash commands
3150 'sf probe/read/write/erase/update'.
3152 Usage requires an initial 'probe' to define the serial
3153 flash parameters, followed by read/write/erase/update
3156 The following defaults may be provided by the platform
3157 to handle the common case when only a single serial
3158 flash is present on the system.
3160 CONFIG_SF_DEFAULT_BUS Bus identifier
3161 CONFIG_SF_DEFAULT_CS Chip-select
3162 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3163 CONFIG_SF_DEFAULT_SPEED in Hz
3167 Define this option to include a destructive SPI flash
3170 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3172 Define this option to use the Bank addr/Extended addr
3173 support on SPI flashes which has size > 16Mbytes.
3175 CONFIG_SF_DUAL_FLASH Dual flash memories
3177 Define this option to use dual flash support where two flash
3178 memories can be connected with a given cs line.
3179 Currently Xilinx Zynq qspi supports these type of connections.
3181 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3182 enable the W#/Vpp signal to disable writing to the status
3183 register on ST MICRON flashes like the N25Q128.
3184 The status register write enable/disable bit, combined with
3185 the W#/VPP signal provides hardware data protection for the
3186 device as follows: When the enable/disable bit is set to 1,
3187 and the W#/VPP signal is driven LOW, the status register
3188 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3189 operation will not execute. The only way to exit this
3190 hardware-protected mode is to drive W#/VPP HIGH.
3192 - SystemACE Support:
3195 Adding this option adds support for Xilinx SystemACE
3196 chips attached via some sort of local bus. The address
3197 of the chip must also be defined in the
3198 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3200 #define CONFIG_SYSTEMACE
3201 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3203 When SystemACE support is added, the "ace" device type
3204 becomes available to the fat commands, i.e. fatls.
3206 - TFTP Fixed UDP Port:
3209 If this is defined, the environment variable tftpsrcp
3210 is used to supply the TFTP UDP source port value.
3211 If tftpsrcp isn't defined, the normal pseudo-random port
3212 number generator is used.
3214 Also, the environment variable tftpdstp is used to supply
3215 the TFTP UDP destination port value. If tftpdstp isn't
3216 defined, the normal port 69 is used.
3218 The purpose for tftpsrcp is to allow a TFTP server to
3219 blindly start the TFTP transfer using the pre-configured
3220 target IP address and UDP port. This has the effect of
3221 "punching through" the (Windows XP) firewall, allowing
3222 the remainder of the TFTP transfer to proceed normally.
3223 A better solution is to properly configure the firewall,
3224 but sometimes that is not allowed.
3229 This enables a generic 'hash' command which can produce
3230 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3234 Enable the hash verify command (hash -v). This adds to code
3237 CONFIG_SHA1 - This option enables support of hashing using SHA1
3238 algorithm. The hash is calculated in software.
3239 CONFIG_SHA256 - This option enables support of hashing using
3240 SHA256 algorithm. The hash is calculated in software.
3241 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3242 for SHA1/SHA256 hashing.
3243 This affects the 'hash' command and also the
3244 hash_lookup_algo() function.
3245 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3246 hardware-acceleration for SHA1/SHA256 progressive hashing.
3247 Data can be streamed in a block at a time and the hashing
3248 is performed in hardware.
3250 Note: There is also a sha1sum command, which should perhaps
3251 be deprecated in favour of 'hash sha1'.
3253 - Freescale i.MX specific commands:
3254 CONFIG_CMD_HDMIDETECT
3255 This enables 'hdmidet' command which returns true if an
3256 HDMI monitor is detected. This command is i.MX 6 specific.
3259 This enables the 'bmode' (bootmode) command for forcing
3260 a boot from specific media.
3262 This is useful for forcing the ROM's usb downloader to
3263 activate upon a watchdog reset which is nice when iterating
3264 on U-Boot. Using the reset button or running bmode normal
3265 will set it back to normal. This command currently
3266 supports i.MX53 and i.MX6.
3271 This enables the RSA algorithm used for FIT image verification
3272 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3274 The Modular Exponentiation algorithm in RSA is implemented using
3275 driver model. So CONFIG_DM needs to be enabled by default for this
3276 library to function.
3278 The signing part is build into mkimage regardless of this
3279 option. The software based modular exponentiation is built into
3280 mkimage irrespective of this option.
3282 - bootcount support:
3283 CONFIG_BOOTCOUNT_LIMIT
3285 This enables the bootcounter support, see:
3286 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3289 enable special bootcounter support on at91sam9xe based boards.
3291 enable special bootcounter support on blackfin based boards.
3293 enable special bootcounter support on da850 based boards.
3294 CONFIG_BOOTCOUNT_RAM
3295 enable support for the bootcounter in RAM
3296 CONFIG_BOOTCOUNT_I2C
3297 enable support for the bootcounter on an i2c (like RTC) device.
3298 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3299 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3301 CONFIG_BOOTCOUNT_ALEN = address len
3303 - Show boot progress:
3304 CONFIG_SHOW_BOOT_PROGRESS
3306 Defining this option allows to add some board-
3307 specific code (calling a user-provided function
3308 "show_boot_progress(int)") that enables you to show
3309 the system's boot progress on some display (for
3310 example, some LED's) on your board. At the moment,
3311 the following checkpoints are implemented:
3313 - Detailed boot stage timing
3315 Define this option to get detailed timing of each stage
3316 of the boot process.
3318 CONFIG_BOOTSTAGE_USER_COUNT
3319 This is the number of available user bootstage records.
3320 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3321 a new ID will be allocated from this stash. If you exceed
3322 the limit, recording will stop.
3324 CONFIG_BOOTSTAGE_REPORT
3325 Define this to print a report before boot, similar to this:
3327 Timer summary in microseconds:
3330 3,575,678 3,575,678 board_init_f start
3331 3,575,695 17 arch_cpu_init A9
3332 3,575,777 82 arch_cpu_init done
3333 3,659,598 83,821 board_init_r start
3334 3,910,375 250,777 main_loop
3335 29,916,167 26,005,792 bootm_start
3336 30,361,327 445,160 start_kernel
3338 CONFIG_CMD_BOOTSTAGE
3339 Add a 'bootstage' command which supports printing a report
3340 and un/stashing of bootstage data.
3342 CONFIG_BOOTSTAGE_FDT
3343 Stash the bootstage information in the FDT. A root 'bootstage'
3344 node is created with each bootstage id as a child. Each child
3345 has a 'name' property and either 'mark' containing the
3346 mark time in microsecond, or 'accum' containing the
3347 accumulated time for that bootstage id in microseconds.
3352 name = "board_init_f";
3361 Code in the Linux kernel can find this in /proc/devicetree.
3363 Legacy uImage format:
3366 1 common/cmd_bootm.c before attempting to boot an image
3367 -1 common/cmd_bootm.c Image header has bad magic number
3368 2 common/cmd_bootm.c Image header has correct magic number
3369 -2 common/cmd_bootm.c Image header has bad checksum
3370 3 common/cmd_bootm.c Image header has correct checksum
3371 -3 common/cmd_bootm.c Image data has bad checksum
3372 4 common/cmd_bootm.c Image data has correct checksum
3373 -4 common/cmd_bootm.c Image is for unsupported architecture
3374 5 common/cmd_bootm.c Architecture check OK
3375 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3376 6 common/cmd_bootm.c Image Type check OK
3377 -6 common/cmd_bootm.c gunzip uncompression error
3378 -7 common/cmd_bootm.c Unimplemented compression type
3379 7 common/cmd_bootm.c Uncompression OK
3380 8 common/cmd_bootm.c No uncompress/copy overwrite error
3381 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3383 9 common/image.c Start initial ramdisk verification
3384 -10 common/image.c Ramdisk header has bad magic number
3385 -11 common/image.c Ramdisk header has bad checksum
3386 10 common/image.c Ramdisk header is OK
3387 -12 common/image.c Ramdisk data has bad checksum
3388 11 common/image.c Ramdisk data has correct checksum
3389 12 common/image.c Ramdisk verification complete, start loading
3390 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3391 13 common/image.c Start multifile image verification
3392 14 common/image.c No initial ramdisk, no multifile, continue.
3394 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3396 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3397 -31 post/post.c POST test failed, detected by post_output_backlog()
3398 -32 post/post.c POST test failed, detected by post_run_single()
3400 34 common/cmd_doc.c before loading a Image from a DOC device
3401 -35 common/cmd_doc.c Bad usage of "doc" command
3402 35 common/cmd_doc.c correct usage of "doc" command
3403 -36 common/cmd_doc.c No boot device
3404 36 common/cmd_doc.c correct boot device
3405 -37 common/cmd_doc.c Unknown Chip ID on boot device
3406 37 common/cmd_doc.c correct chip ID found, device available
3407 -38 common/cmd_doc.c Read Error on boot device
3408 38 common/cmd_doc.c reading Image header from DOC device OK
3409 -39 common/cmd_doc.c Image header has bad magic number
3410 39 common/cmd_doc.c Image header has correct magic number
3411 -40 common/cmd_doc.c Error reading Image from DOC device
3412 40 common/cmd_doc.c Image header has correct magic number
3413 41 common/cmd_ide.c before loading a Image from a IDE device
3414 -42 common/cmd_ide.c Bad usage of "ide" command
3415 42 common/cmd_ide.c correct usage of "ide" command
3416 -43 common/cmd_ide.c No boot device
3417 43 common/cmd_ide.c boot device found
3418 -44 common/cmd_ide.c Device not available
3419 44 common/cmd_ide.c Device available
3420 -45 common/cmd_ide.c wrong partition selected
3421 45 common/cmd_ide.c partition selected
3422 -46 common/cmd_ide.c Unknown partition table
3423 46 common/cmd_ide.c valid partition table found
3424 -47 common/cmd_ide.c Invalid partition type
3425 47 common/cmd_ide.c correct partition type
3426 -48 common/cmd_ide.c Error reading Image Header on boot device
3427 48 common/cmd_ide.c reading Image Header from IDE device OK
3428 -49 common/cmd_ide.c Image header has bad magic number
3429 49 common/cmd_ide.c Image header has correct magic number
3430 -50 common/cmd_ide.c Image header has bad checksum
3431 50 common/cmd_ide.c Image header has correct checksum
3432 -51 common/cmd_ide.c Error reading Image from IDE device
3433 51 common/cmd_ide.c reading Image from IDE device OK
3434 52 common/cmd_nand.c before loading a Image from a NAND device
3435 -53 common/cmd_nand.c Bad usage of "nand" command
3436 53 common/cmd_nand.c correct usage of "nand" command
3437 -54 common/cmd_nand.c No boot device
3438 54 common/cmd_nand.c boot device found
3439 -55 common/cmd_nand.c Unknown Chip ID on boot device
3440 55 common/cmd_nand.c correct chip ID found, device available
3441 -56 common/cmd_nand.c Error reading Image Header on boot device
3442 56 common/cmd_nand.c reading Image Header from NAND device OK
3443 -57 common/cmd_nand.c Image header has bad magic number
3444 57 common/cmd_nand.c Image header has correct magic number
3445 -58 common/cmd_nand.c Error reading Image from NAND device
3446 58 common/cmd_nand.c reading Image from NAND device OK
3448 -60 common/env_common.c Environment has a bad CRC, using default
3450 64 net/eth.c starting with Ethernet configuration.
3451 -64 net/eth.c no Ethernet found.
3452 65 net/eth.c Ethernet found.
3454 -80 common/cmd_net.c usage wrong
3455 80 common/cmd_net.c before calling NetLoop()
3456 -81 common/cmd_net.c some error in NetLoop() occurred
3457 81 common/cmd_net.c NetLoop() back without error
3458 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3459 82 common/cmd_net.c trying automatic boot
3460 83 common/cmd_net.c running "source" command
3461 -83 common/cmd_net.c some error in automatic boot or "source" command
3462 84 common/cmd_net.c end without errors
3467 100 common/cmd_bootm.c Kernel FIT Image has correct format
3468 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3469 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3470 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3471 102 common/cmd_bootm.c Kernel unit name specified
3472 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3473 103 common/cmd_bootm.c Found configuration node
3474 104 common/cmd_bootm.c Got kernel subimage node offset
3475 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3476 105 common/cmd_bootm.c Kernel subimage hash verification OK
3477 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3478 106 common/cmd_bootm.c Architecture check OK
3479 -106 common/cmd_bootm.c Kernel subimage has wrong type
3480 107 common/cmd_bootm.c Kernel subimage type OK
3481 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3482 108 common/cmd_bootm.c Got kernel subimage data/size
3483 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3484 -109 common/cmd_bootm.c Can't get kernel subimage type
3485 -110 common/cmd_bootm.c Can't get kernel subimage comp
3486 -111 common/cmd_bootm.c Can't get kernel subimage os
3487 -112 common/cmd_bootm.c Can't get kernel subimage load address
3488 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3490 120 common/image.c Start initial ramdisk verification
3491 -120 common/image.c Ramdisk FIT image has incorrect format
3492 121 common/image.c Ramdisk FIT image has correct format
3493 122 common/image.c No ramdisk subimage unit name, using configuration
3494 -122 common/image.c Can't get configuration for ramdisk subimage
3495 123 common/image.c Ramdisk unit name specified
3496 -124 common/image.c Can't get ramdisk subimage node offset
3497 125 common/image.c Got ramdisk subimage node offset
3498 -125 common/image.c Ramdisk subimage hash verification failed
3499 126 common/image.c Ramdisk subimage hash verification OK
3500 -126 common/image.c Ramdisk subimage for unsupported architecture
3501 127 common/image.c Architecture check OK
3502 -127 common/image.c Can't get ramdisk subimage data/size
3503 128 common/image.c Got ramdisk subimage data/size
3504 129 common/image.c Can't get ramdisk load address
3505 -129 common/image.c Got ramdisk load address
3507 -130 common/cmd_doc.c Incorrect FIT image format
3508 131 common/cmd_doc.c FIT image format OK
3510 -140 common/cmd_ide.c Incorrect FIT image format
3511 141 common/cmd_ide.c FIT image format OK
3513 -150 common/cmd_nand.c Incorrect FIT image format
3514 151 common/cmd_nand.c FIT image format OK
3516 - legacy image format:
3517 CONFIG_IMAGE_FORMAT_LEGACY
3518 enables the legacy image format support in U-Boot.
3521 enabled if CONFIG_FIT_SIGNATURE is not defined.
3523 CONFIG_DISABLE_IMAGE_LEGACY
3524 disable the legacy image format
3526 This define is introduced, as the legacy image format is
3527 enabled per default for backward compatibility.
3529 - FIT image support:
3531 Enable support for the FIT uImage format.
3533 CONFIG_FIT_BEST_MATCH
3534 When no configuration is explicitly selected, default to the
3535 one whose fdt's compatibility field best matches that of
3536 U-Boot itself. A match is considered "best" if it matches the
3537 most specific compatibility entry of U-Boot's fdt's root node.
3538 The order of entries in the configuration's fdt is ignored.
3540 CONFIG_FIT_SIGNATURE
3541 This option enables signature verification of FIT uImages,
3542 using a hash signed and verified using RSA. If
3543 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3544 hashing is available using hardware, RSA library will use it.
3545 See doc/uImage.FIT/signature.txt for more details.
3547 WARNING: When relying on signed FIT images with required
3548 signature check the legacy image format is default
3549 disabled. If a board need legacy image format support
3550 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3552 CONFIG_FIT_DISABLE_SHA256
3553 Supporting SHA256 hashes has quite an impact on binary size.
3554 For constrained systems sha256 hash support can be disabled
3557 - Standalone program support:
3558 CONFIG_STANDALONE_LOAD_ADDR
3560 This option defines a board specific value for the
3561 address where standalone program gets loaded, thus
3562 overwriting the architecture dependent default
3565 - Frame Buffer Address:
3568 Define CONFIG_FB_ADDR if you want to use specific
3569 address for frame buffer. This is typically the case
3570 when using a graphics controller has separate video
3571 memory. U-Boot will then place the frame buffer at
3572 the given address instead of dynamically reserving it
3573 in system RAM by calling lcd_setmem(), which grabs
3574 the memory for the frame buffer depending on the
3575 configured panel size.
3577 Please see board_init_f function.
3579 - Automatic software updates via TFTP server
3581 CONFIG_UPDATE_TFTP_CNT_MAX
3582 CONFIG_UPDATE_TFTP_MSEC_MAX
3584 These options enable and control the auto-update feature;
3585 for a more detailed description refer to doc/README.update.
3587 - MTD Support (mtdparts command, UBI support)
3590 Adds the MTD device infrastructure from the Linux kernel.
3591 Needed for mtdparts command support.
3593 CONFIG_MTD_PARTITIONS
3595 Adds the MTD partitioning infrastructure from the Linux
3596 kernel. Needed for UBI support.
3598 CONFIG_MTD_NAND_VERIFY_WRITE
3599 verify if the written data is correct reread.
3604 Adds commands for interacting with MTD partitions formatted
3605 with the UBI flash translation layer
3607 Requires also defining CONFIG_RBTREE
3609 CONFIG_UBI_SILENCE_MSG
3611 Make the verbose messages from UBI stop printing. This leaves
3612 warnings and errors enabled.
3615 CONFIG_MTD_UBI_WL_THRESHOLD
3616 This parameter defines the maximum difference between the highest
3617 erase counter value and the lowest erase counter value of eraseblocks
3618 of UBI devices. When this threshold is exceeded, UBI starts performing
3619 wear leveling by means of moving data from eraseblock with low erase
3620 counter to eraseblocks with high erase counter.
3622 The default value should be OK for SLC NAND flashes, NOR flashes and
3623 other flashes which have eraseblock life-cycle 100000 or more.
3624 However, in case of MLC NAND flashes which typically have eraseblock
3625 life-cycle less than 10000, the threshold should be lessened (e.g.,
3626 to 128 or 256, although it does not have to be power of 2).
3630 CONFIG_MTD_UBI_BEB_LIMIT
3631 This option specifies the maximum bad physical eraseblocks UBI
3632 expects on the MTD device (per 1024 eraseblocks). If the
3633 underlying flash does not admit of bad eraseblocks (e.g. NOR
3634 flash), this value is ignored.
3636 NAND datasheets often specify the minimum and maximum NVM
3637 (Number of Valid Blocks) for the flashes' endurance lifetime.
3638 The maximum expected bad eraseblocks per 1024 eraseblocks
3639 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3640 which gives 20 for most NANDs (MaxNVB is basically the total
3641 count of eraseblocks on the chip).
3643 To put it differently, if this value is 20, UBI will try to
3644 reserve about 1.9% of physical eraseblocks for bad blocks
3645 handling. And that will be 1.9% of eraseblocks on the entire
3646 NAND chip, not just the MTD partition UBI attaches. This means
3647 that if you have, say, a NAND flash chip admits maximum 40 bad
3648 eraseblocks, and it is split on two MTD partitions of the same
3649 size, UBI will reserve 40 eraseblocks when attaching a
3654 CONFIG_MTD_UBI_FASTMAP
3655 Fastmap is a mechanism which allows attaching an UBI device
3656 in nearly constant time. Instead of scanning the whole MTD device it
3657 only has to locate a checkpoint (called fastmap) on the device.
3658 The on-flash fastmap contains all information needed to attach
3659 the device. Using fastmap makes only sense on large devices where
3660 attaching by scanning takes long. UBI will not automatically install
3661 a fastmap on old images, but you can set the UBI parameter
3662 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3663 that fastmap-enabled images are still usable with UBI implementations
3664 without fastmap support. On typical flash devices the whole fastmap
3665 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3667 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3668 Set this parameter to enable fastmap automatically on images
3675 Adds commands for interacting with UBI volumes formatted as
3676 UBIFS. UBIFS is read-only in u-boot.
3678 Requires UBI support as well as CONFIG_LZO
3680 CONFIG_UBIFS_SILENCE_MSG
3682 Make the verbose messages from UBIFS stop printing. This leaves
3683 warnings and errors enabled.
3687 Enable building of SPL globally.
3690 LDSCRIPT for linking the SPL binary.
3692 CONFIG_SPL_MAX_FOOTPRINT
3693 Maximum size in memory allocated to the SPL, BSS included.
3694 When defined, the linker checks that the actual memory
3695 used by SPL from _start to __bss_end does not exceed it.
3696 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3697 must not be both defined at the same time.
3700 Maximum size of the SPL image (text, data, rodata, and
3701 linker lists sections), BSS excluded.
3702 When defined, the linker checks that the actual size does
3705 CONFIG_SPL_TEXT_BASE
3706 TEXT_BASE for linking the SPL binary.
3708 CONFIG_SPL_RELOC_TEXT_BASE
3709 Address to relocate to. If unspecified, this is equal to
3710 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3712 CONFIG_SPL_BSS_START_ADDR
3713 Link address for the BSS within the SPL binary.
3715 CONFIG_SPL_BSS_MAX_SIZE
3716 Maximum size in memory allocated to the SPL BSS.
3717 When defined, the linker checks that the actual memory used
3718 by SPL from __bss_start to __bss_end does not exceed it.
3719 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3720 must not be both defined at the same time.
3723 Adress of the start of the stack SPL will use
3725 CONFIG_SPL_RELOC_STACK
3726 Adress of the start of the stack SPL will use after
3727 relocation. If unspecified, this is equal to
3730 CONFIG_SYS_SPL_MALLOC_START
3731 Starting address of the malloc pool used in SPL.
3733 CONFIG_SYS_SPL_MALLOC_SIZE
3734 The size of the malloc pool used in SPL.
3736 CONFIG_SPL_FRAMEWORK
3737 Enable the SPL framework under common/. This framework
3738 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3739 NAND loading of the Linux Kernel.
3742 Enable booting directly to an OS from SPL.
3743 See also: doc/README.falcon
3745 CONFIG_SPL_DISPLAY_PRINT
3746 For ARM, enable an optional function to print more information
3747 about the running system.
3749 CONFIG_SPL_INIT_MINIMAL
3750 Arch init code should be built for a very small image
3752 CONFIG_SPL_LIBCOMMON_SUPPORT
3753 Support for common/libcommon.o in SPL binary
3755 CONFIG_SPL_LIBDISK_SUPPORT
3756 Support for disk/libdisk.o in SPL binary
3758 CONFIG_SPL_I2C_SUPPORT
3759 Support for drivers/i2c/libi2c.o in SPL binary
3761 CONFIG_SPL_GPIO_SUPPORT
3762 Support for drivers/gpio/libgpio.o in SPL binary
3764 CONFIG_SPL_MMC_SUPPORT
3765 Support for drivers/mmc/libmmc.o in SPL binary
3767 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3768 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3769 Address and partition on the MMC to load U-Boot from
3770 when the MMC is being used in raw mode.
3772 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3773 Partition on the MMC to load U-Boot from when the MMC is being
3776 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3777 Sector to load kernel uImage from when MMC is being
3778 used in raw mode (for Falcon mode)
3780 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3781 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3782 Sector and number of sectors to load kernel argument
3783 parameters from when MMC is being used in raw mode
3786 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3787 Partition on the MMC to load U-Boot from when the MMC is being
3790 CONFIG_SPL_FAT_SUPPORT
3791 Support for fs/fat/libfat.o in SPL binary
3793 CONFIG_SPL_EXT_SUPPORT
3794 Support for EXT filesystem in SPL binary
3796 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3797 Filename to read to load U-Boot when reading from filesystem
3799 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3800 Filename to read to load kernel uImage when reading
3801 from filesystem (for Falcon mode)
3803 CONFIG_SPL_FS_LOAD_ARGS_NAME
3804 Filename to read to load kernel argument parameters
3805 when reading from filesystem (for Falcon mode)
3807 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3808 Set this for NAND SPL on PPC mpc83xx targets, so that
3809 start.S waits for the rest of the SPL to load before
3810 continuing (the hardware starts execution after just
3811 loading the first page rather than the full 4K).
3813 CONFIG_SPL_SKIP_RELOCATE
3814 Avoid SPL relocation
3816 CONFIG_SPL_NAND_BASE
3817 Include nand_base.c in the SPL. Requires
3818 CONFIG_SPL_NAND_DRIVERS.
3820 CONFIG_SPL_NAND_DRIVERS
3821 SPL uses normal NAND drivers, not minimal drivers.
3824 Include standard software ECC in the SPL
3826 CONFIG_SPL_NAND_SIMPLE
3827 Support for NAND boot using simple NAND drivers that
3828 expose the cmd_ctrl() interface.
3830 CONFIG_SPL_MTD_SUPPORT
3831 Support for the MTD subsystem within SPL. Useful for
3832 environment on NAND support within SPL.
3834 CONFIG_SPL_NAND_RAW_ONLY
3835 Support to boot only raw u-boot.bin images. Use this only
3836 if you need to save space.
3838 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3839 Set for the SPL on PPC mpc8xxx targets, support for
3840 drivers/ddr/fsl/libddr.o in SPL binary.
3842 CONFIG_SPL_COMMON_INIT_DDR
3843 Set for common ddr init with serial presence detect in
3846 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3847 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3848 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3849 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3850 CONFIG_SYS_NAND_ECCBYTES
3851 Defines the size and behavior of the NAND that SPL uses
3854 CONFIG_SPL_NAND_BOOT
3855 Add support NAND boot
3857 CONFIG_SYS_NAND_U_BOOT_OFFS
3858 Location in NAND to read U-Boot from
3860 CONFIG_SYS_NAND_U_BOOT_DST
3861 Location in memory to load U-Boot to
3863 CONFIG_SYS_NAND_U_BOOT_SIZE
3864 Size of image to load
3866 CONFIG_SYS_NAND_U_BOOT_START
3867 Entry point in loaded image to jump to
3869 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3870 Define this if you need to first read the OOB and then the
3871 data. This is used, for example, on davinci platforms.
3873 CONFIG_SPL_OMAP3_ID_NAND
3874 Support for an OMAP3-specific set of functions to return the
3875 ID and MFR of the first attached NAND chip, if present.
3877 CONFIG_SPL_SERIAL_SUPPORT
3878 Support for drivers/serial/libserial.o in SPL binary
3880 CONFIG_SPL_SPI_FLASH_SUPPORT
3881 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3883 CONFIG_SPL_SPI_SUPPORT
3884 Support for drivers/spi/libspi.o in SPL binary
3886 CONFIG_SPL_RAM_DEVICE
3887 Support for running image already present in ram, in SPL binary
3889 CONFIG_SPL_LIBGENERIC_SUPPORT
3890 Support for lib/libgeneric.o in SPL binary
3892 CONFIG_SPL_ENV_SUPPORT
3893 Support for the environment operating in SPL binary
3895 CONFIG_SPL_NET_SUPPORT
3896 Support for the net/libnet.o in SPL binary.
3897 It conflicts with SPL env from storage medium specified by
3898 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3901 Image offset to which the SPL should be padded before appending
3902 the SPL payload. By default, this is defined as
3903 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3904 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3905 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3908 Final target image containing SPL and payload. Some SPLs
3909 use an arch-specific makefile fragment instead, for
3910 example if more than one image needs to be produced.
3912 CONFIG_FIT_SPL_PRINT
3913 Printing information about a FIT image adds quite a bit of
3914 code to SPL. So this is normally disabled in SPL. Use this
3915 option to re-enable it. This will affect the output of the
3916 bootm command when booting a FIT image.
3920 Enable building of TPL globally.
3923 Image offset to which the TPL should be padded before appending
3924 the TPL payload. By default, this is defined as
3925 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3926 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3927 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3932 [so far only for SMDK2400 boards]
3934 - Modem support enable:
3935 CONFIG_MODEM_SUPPORT
3937 - RTS/CTS Flow control enable:
3940 - Modem debug support:
3941 CONFIG_MODEM_SUPPORT_DEBUG
3943 Enables debugging stuff (char screen[1024], dbg())
3944 for modem support. Useful only with BDI2000.
3946 - Interrupt support (PPC):
3948 There are common interrupt_init() and timer_interrupt()
3949 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3950 for CPU specific initialization. interrupt_init_cpu()
3951 should set decrementer_count to appropriate value. If
3952 CPU resets decrementer automatically after interrupt
3953 (ppc4xx) it should set decrementer_count to zero.
3954 timer_interrupt() calls timer_interrupt_cpu() for CPU
3955 specific handling. If board has watchdog / status_led
3956 / other_activity_monitor it works automatically from
3957 general timer_interrupt().
3961 In the target system modem support is enabled when a
3962 specific key (key combination) is pressed during
3963 power-on. Otherwise U-Boot will boot normally
3964 (autoboot). The key_pressed() function is called from
3965 board_init(). Currently key_pressed() is a dummy
3966 function, returning 1 and thus enabling modem
3969 If there are no modem init strings in the
3970 environment, U-Boot proceed to autoboot; the
3971 previous output (banner, info printfs) will be
3974 See also: doc/README.Modem
3976 Board initialization settings:
3977 ------------------------------
3979 During Initialization u-boot calls a number of board specific functions
3980 to allow the preparation of board specific prerequisites, e.g. pin setup
3981 before drivers are initialized. To enable these callbacks the
3982 following configuration macros have to be defined. Currently this is
3983 architecture specific, so please check arch/your_architecture/lib/board.c
3984 typically in board_init_f() and board_init_r().
3986 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3987 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3988 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3989 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3991 Configuration Settings:
3992 -----------------------
3994 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3995 Optionally it can be defined to support 64-bit memory commands.
3997 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3998 undefine this when you're short of memory.
4000 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
4001 width of the commands listed in the 'help' command output.
4003 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
4004 prompt for user input.
4006 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
4008 - CONFIG_SYS_PBSIZE: Buffer size for Console output
4010 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
4012 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
4013 the application (usually a Linux kernel) when it is
4016 - CONFIG_SYS_BAUDRATE_TABLE:
4017 List of legal baudrate settings for this board.
4019 - CONFIG_SYS_CONSOLE_INFO_QUIET
4020 Suppress display of console information at boot.
4022 - CONFIG_SYS_CONSOLE_IS_IN_ENV
4023 If the board specific function
4024 extern int overwrite_console (void);
4025 returns 1, the stdin, stderr and stdout are switched to the
4026 serial port, else the settings in the environment are used.
4028 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
4029 Enable the call to overwrite_console().
4031 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
4032 Enable overwrite of previous console environment settings.
4034 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
4035 Begin and End addresses of the area used by the
4038 - CONFIG_SYS_ALT_MEMTEST:
4039 Enable an alternate, more extensive memory test.
4041 - CONFIG_SYS_MEMTEST_SCRATCH:
4042 Scratch address used by the alternate memory test
4043 You only need to set this if address zero isn't writeable
4045 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
4046 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
4047 this specified memory area will get subtracted from the top
4048 (end) of RAM and won't get "touched" at all by U-Boot. By
4049 fixing up gd->ram_size the Linux kernel should gets passed
4050 the now "corrected" memory size and won't touch it either.
4051 This should work for arch/ppc and arch/powerpc. Only Linux
4052 board ports in arch/powerpc with bootwrapper support that
4053 recalculate the memory size from the SDRAM controller setup
4054 will have to get fixed in Linux additionally.
4056 This option can be used as a workaround for the 440EPx/GRx
4057 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
4060 WARNING: Please make sure that this value is a multiple of
4061 the Linux page size (normally 4k). If this is not the case,
4062 then the end address of the Linux memory will be located at a
4063 non page size aligned address and this could cause major
4066 - CONFIG_SYS_LOADS_BAUD_CHANGE:
4067 Enable temporary baudrate change while serial download
4069 - CONFIG_SYS_SDRAM_BASE:
4070 Physical start address of SDRAM. _Must_ be 0 here.
4072 - CONFIG_SYS_MBIO_BASE:
4073 Physical start address of Motherboard I/O (if using a
4076 - CONFIG_SYS_FLASH_BASE:
4077 Physical start address of Flash memory.
4079 - CONFIG_SYS_MONITOR_BASE:
4080 Physical start address of boot monitor code (set by
4081 make config files to be same as the text base address
4082 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4083 CONFIG_SYS_FLASH_BASE when booting from flash.
4085 - CONFIG_SYS_MONITOR_LEN:
4086 Size of memory reserved for monitor code, used to
4087 determine _at_compile_time_ (!) if the environment is
4088 embedded within the U-Boot image, or in a separate
4091 - CONFIG_SYS_MALLOC_LEN:
4092 Size of DRAM reserved for malloc() use.
4094 - CONFIG_SYS_MALLOC_F_LEN
4095 Size of the malloc() pool for use before relocation. If
4096 this is defined, then a very simple malloc() implementation
4097 will become available before relocation. The address is just
4098 below the global data, and the stack is moved down to make
4101 This feature allocates regions with increasing addresses
4102 within the region. calloc() is supported, but realloc()
4103 is not available. free() is supported but does nothing.
4104 The memory will be freed (or in fact just forgotten) when
4105 U-Boot relocates itself.
4107 Pre-relocation malloc() is only supported on ARM and sandbox
4108 at present but is fairly easy to enable for other archs.
4110 - CONFIG_SYS_MALLOC_SIMPLE
4111 Provides a simple and small malloc() and calloc() for those
4112 boards which do not use the full malloc in SPL (which is
4113 enabled with CONFIG_SYS_SPL_MALLOC_START).
4115 - CONFIG_SYS_NONCACHED_MEMORY:
4116 Size of non-cached memory area. This area of memory will be
4117 typically located right below the malloc() area and mapped
4118 uncached in the MMU. This is useful for drivers that would
4119 otherwise require a lot of explicit cache maintenance. For
4120 some drivers it's also impossible to properly maintain the
4121 cache. For example if the regions that need to be flushed
4122 are not a multiple of the cache-line size, *and* padding
4123 cannot be allocated between the regions to align them (i.e.
4124 if the HW requires a contiguous array of regions, and the
4125 size of each region is not cache-aligned), then a flush of
4126 one region may result in overwriting data that hardware has
4127 written to another region in the same cache-line. This can
4128 happen for example in network drivers where descriptors for
4129 buffers are typically smaller than the CPU cache-line (e.g.
4130 16 bytes vs. 32 or 64 bytes).
4132 Non-cached memory is only supported on 32-bit ARM at present.
4134 - CONFIG_SYS_BOOTM_LEN:
4135 Normally compressed uImages are limited to an
4136 uncompressed size of 8 MBytes. If this is not enough,
4137 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4138 to adjust this setting to your needs.
4140 - CONFIG_SYS_BOOTMAPSZ:
4141 Maximum size of memory mapped by the startup code of
4142 the Linux kernel; all data that must be processed by
4143 the Linux kernel (bd_info, boot arguments, FDT blob if
4144 used) must be put below this limit, unless "bootm_low"
4145 environment variable is defined and non-zero. In such case
4146 all data for the Linux kernel must be between "bootm_low"
4147 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4148 variable "bootm_mapsize" will override the value of
4149 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4150 then the value in "bootm_size" will be used instead.
4152 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4153 Enable initrd_high functionality. If defined then the
4154 initrd_high feature is enabled and the bootm ramdisk subcommand
4157 - CONFIG_SYS_BOOT_GET_CMDLINE:
4158 Enables allocating and saving kernel cmdline in space between
4159 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4161 - CONFIG_SYS_BOOT_GET_KBD:
4162 Enables allocating and saving a kernel copy of the bd_info in
4163 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4165 - CONFIG_SYS_MAX_FLASH_BANKS:
4166 Max number of Flash memory banks
4168 - CONFIG_SYS_MAX_FLASH_SECT:
4169 Max number of sectors on a Flash chip
4171 - CONFIG_SYS_FLASH_ERASE_TOUT:
4172 Timeout for Flash erase operations (in ms)
4174 - CONFIG_SYS_FLASH_WRITE_TOUT:
4175 Timeout for Flash write operations (in ms)
4177 - CONFIG_SYS_FLASH_LOCK_TOUT
4178 Timeout for Flash set sector lock bit operation (in ms)
4180 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4181 Timeout for Flash clear lock bits operation (in ms)
4183 - CONFIG_SYS_FLASH_PROTECTION
4184 If defined, hardware flash sectors protection is used
4185 instead of U-Boot software protection.
4187 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4189 Enable TFTP transfers directly to flash memory;
4190 without this option such a download has to be
4191 performed in two steps: (1) download to RAM, and (2)
4192 copy from RAM to flash.
4194 The two-step approach is usually more reliable, since
4195 you can check if the download worked before you erase
4196 the flash, but in some situations (when system RAM is
4197 too limited to allow for a temporary copy of the
4198 downloaded image) this option may be very useful.
4200 - CONFIG_SYS_FLASH_CFI:
4201 Define if the flash driver uses extra elements in the
4202 common flash structure for storing flash geometry.
4204 - CONFIG_FLASH_CFI_DRIVER
4205 This option also enables the building of the cfi_flash driver
4206 in the drivers directory
4208 - CONFIG_FLASH_CFI_MTD
4209 This option enables the building of the cfi_mtd driver
4210 in the drivers directory. The driver exports CFI flash
4213 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4214 Use buffered writes to flash.
4216 - CONFIG_FLASH_SPANSION_S29WS_N
4217 s29ws-n MirrorBit flash has non-standard addresses for buffered
4220 - CONFIG_SYS_FLASH_QUIET_TEST
4221 If this option is defined, the common CFI flash doesn't
4222 print it's warning upon not recognized FLASH banks. This
4223 is useful, if some of the configured banks are only
4224 optionally available.
4226 - CONFIG_FLASH_SHOW_PROGRESS
4227 If defined (must be an integer), print out countdown
4228 digits and dots. Recommended value: 45 (9..1) for 80
4229 column displays, 15 (3..1) for 40 column displays.
4231 - CONFIG_FLASH_VERIFY
4232 If defined, the content of the flash (destination) is compared
4233 against the source after the write operation. An error message
4234 will be printed when the contents are not identical.
4235 Please note that this option is useless in nearly all cases,
4236 since such flash programming errors usually are detected earlier
4237 while unprotecting/erasing/programming. Please only enable
4238 this option if you really know what you are doing.
4240 - CONFIG_SYS_RX_ETH_BUFFER:
4241 Defines the number of Ethernet receive buffers. On some
4242 Ethernet controllers it is recommended to set this value
4243 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4244 buffers can be full shortly after enabling the interface
4245 on high Ethernet traffic.
4246 Defaults to 4 if not defined.
4248 - CONFIG_ENV_MAX_ENTRIES
4250 Maximum number of entries in the hash table that is used
4251 internally to store the environment settings. The default
4252 setting is supposed to be generous and should work in most
4253 cases. This setting can be used to tune behaviour; see
4254 lib/hashtable.c for details.
4256 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4257 - CONFIG_ENV_FLAGS_LIST_STATIC
4258 Enable validation of the values given to environment variables when
4259 calling env set. Variables can be restricted to only decimal,
4260 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4261 the variables can also be restricted to IP address or MAC address.
4263 The format of the list is:
4264 type_attribute = [s|d|x|b|i|m]
4265 access_attribute = [a|r|o|c]
4266 attributes = type_attribute[access_attribute]
4267 entry = variable_name[:attributes]
4270 The type attributes are:
4271 s - String (default)
4274 b - Boolean ([1yYtT|0nNfF])
4278 The access attributes are:
4284 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4285 Define this to a list (string) to define the ".flags"
4286 environment variable in the default or embedded environment.
4288 - CONFIG_ENV_FLAGS_LIST_STATIC
4289 Define this to a list (string) to define validation that
4290 should be done if an entry is not found in the ".flags"
4291 environment variable. To override a setting in the static
4292 list, simply add an entry for the same variable name to the
4295 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4296 If defined, don't allow the -f switch to env set override variable
4299 - CONFIG_SYS_GENERIC_BOARD
4300 This selects the architecture-generic board system instead of the
4301 architecture-specific board files. It is intended to move boards
4302 to this new framework over time. Defining this will disable the
4303 arch/foo/lib/board.c file and use common/board_f.c and
4304 common/board_r.c instead. To use this option your architecture
4305 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4306 its config.mk file). If you find problems enabling this option on
4307 your board please report the problem and send patches!
4309 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4310 This is set by OMAP boards for the max time that reset should
4311 be asserted. See doc/README.omap-reset-time for details on how
4312 the value can be calculated on a given board.
4315 If stdint.h is available with your toolchain you can define this
4316 option to enable it. You can provide option 'USE_STDINT=1' when
4317 building U-Boot to enable this.
4319 The following definitions that deal with the placement and management
4320 of environment data (variable area); in general, we support the
4321 following configurations:
4323 - CONFIG_BUILD_ENVCRC:
4325 Builds up envcrc with the target environment so that external utils
4326 may easily extract it and embed it in final U-Boot images.
4328 - CONFIG_ENV_IS_IN_FLASH:
4330 Define this if the environment is in flash memory.
4332 a) The environment occupies one whole flash sector, which is
4333 "embedded" in the text segment with the U-Boot code. This
4334 happens usually with "bottom boot sector" or "top boot
4335 sector" type flash chips, which have several smaller
4336 sectors at the start or the end. For instance, such a
4337 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4338 such a case you would place the environment in one of the
4339 4 kB sectors - with U-Boot code before and after it. With
4340 "top boot sector" type flash chips, you would put the
4341 environment in one of the last sectors, leaving a gap
4342 between U-Boot and the environment.
4344 - CONFIG_ENV_OFFSET:
4346 Offset of environment data (variable area) to the
4347 beginning of flash memory; for instance, with bottom boot
4348 type flash chips the second sector can be used: the offset
4349 for this sector is given here.
4351 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4355 This is just another way to specify the start address of
4356 the flash sector containing the environment (instead of
4359 - CONFIG_ENV_SECT_SIZE:
4361 Size of the sector containing the environment.
4364 b) Sometimes flash chips have few, equal sized, BIG sectors.
4365 In such a case you don't want to spend a whole sector for
4370 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4371 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4372 of this flash sector for the environment. This saves
4373 memory for the RAM copy of the environment.
4375 It may also save flash memory if you decide to use this
4376 when your environment is "embedded" within U-Boot code,
4377 since then the remainder of the flash sector could be used
4378 for U-Boot code. It should be pointed out that this is
4379 STRONGLY DISCOURAGED from a robustness point of view:
4380 updating the environment in flash makes it always
4381 necessary to erase the WHOLE sector. If something goes
4382 wrong before the contents has been restored from a copy in
4383 RAM, your target system will be dead.
4385 - CONFIG_ENV_ADDR_REDUND
4386 CONFIG_ENV_SIZE_REDUND
4388 These settings describe a second storage area used to hold
4389 a redundant copy of the environment data, so that there is
4390 a valid backup copy in case there is a power failure during
4391 a "saveenv" operation.
4393 BE CAREFUL! Any changes to the flash layout, and some changes to the
4394 source code will make it necessary to adapt <board>/u-boot.lds*
4398 - CONFIG_ENV_IS_IN_NVRAM:
4400 Define this if you have some non-volatile memory device
4401 (NVRAM, battery buffered SRAM) which you want to use for the
4407 These two #defines are used to determine the memory area you
4408 want to use for environment. It is assumed that this memory
4409 can just be read and written to, without any special
4412 BE CAREFUL! The first access to the environment happens quite early
4413 in U-Boot initialization (when we try to get the setting of for the
4414 console baudrate). You *MUST* have mapped your NVRAM area then, or
4417 Please note that even with NVRAM we still use a copy of the
4418 environment in RAM: we could work on NVRAM directly, but we want to
4419 keep settings there always unmodified except somebody uses "saveenv"
4420 to save the current settings.
4423 - CONFIG_ENV_IS_IN_EEPROM:
4425 Use this if you have an EEPROM or similar serial access
4426 device and a driver for it.
4428 - CONFIG_ENV_OFFSET:
4431 These two #defines specify the offset and size of the
4432 environment area within the total memory of your EEPROM.
4434 - CONFIG_SYS_I2C_EEPROM_ADDR:
4435 If defined, specified the chip address of the EEPROM device.
4436 The default address is zero.
4438 - CONFIG_SYS_I2C_EEPROM_BUS:
4439 If defined, specified the i2c bus of the EEPROM device.
4441 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4442 If defined, the number of bits used to address bytes in a
4443 single page in the EEPROM device. A 64 byte page, for example
4444 would require six bits.
4446 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4447 If defined, the number of milliseconds to delay between
4448 page writes. The default is zero milliseconds.
4450 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4451 The length in bytes of the EEPROM memory array address. Note
4452 that this is NOT the chip address length!
4454 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4455 EEPROM chips that implement "address overflow" are ones
4456 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4457 address and the extra bits end up in the "chip address" bit
4458 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4461 Note that we consider the length of the address field to
4462 still be one byte because the extra address bits are hidden
4463 in the chip address.
4465 - CONFIG_SYS_EEPROM_SIZE:
4466 The size in bytes of the EEPROM device.
4468 - CONFIG_ENV_EEPROM_IS_ON_I2C
4469 define this, if you have I2C and SPI activated, and your
4470 EEPROM, which holds the environment, is on the I2C bus.
4472 - CONFIG_I2C_ENV_EEPROM_BUS
4473 if you have an Environment on an EEPROM reached over
4474 I2C muxes, you can define here, how to reach this
4475 EEPROM. For example:
4477 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4479 EEPROM which holds the environment, is reached over
4480 a pca9547 i2c mux with address 0x70, channel 3.
4482 - CONFIG_ENV_IS_IN_DATAFLASH:
4484 Define this if you have a DataFlash memory device which you
4485 want to use for the environment.
4487 - CONFIG_ENV_OFFSET:
4491 These three #defines specify the offset and size of the
4492 environment area within the total memory of your DataFlash placed
4493 at the specified address.
4495 - CONFIG_ENV_IS_IN_SPI_FLASH:
4497 Define this if you have a SPI Flash memory device which you
4498 want to use for the environment.
4500 - CONFIG_ENV_OFFSET:
4503 These two #defines specify the offset and size of the
4504 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4505 aligned to an erase sector boundary.
4507 - CONFIG_ENV_SECT_SIZE:
4509 Define the SPI flash's sector size.
4511 - CONFIG_ENV_OFFSET_REDUND (optional):
4513 This setting describes a second storage area of CONFIG_ENV_SIZE
4514 size used to hold a redundant copy of the environment data, so
4515 that there is a valid backup copy in case there is a power failure
4516 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4517 aligned to an erase sector boundary.
4519 - CONFIG_ENV_SPI_BUS (optional):
4520 - CONFIG_ENV_SPI_CS (optional):
4522 Define the SPI bus and chip select. If not defined they will be 0.
4524 - CONFIG_ENV_SPI_MAX_HZ (optional):
4526 Define the SPI max work clock. If not defined then use 1MHz.
4528 - CONFIG_ENV_SPI_MODE (optional):
4530 Define the SPI work mode. If not defined then use SPI_MODE_3.
4532 - CONFIG_ENV_IS_IN_REMOTE:
4534 Define this if you have a remote memory space which you
4535 want to use for the local device's environment.
4540 These two #defines specify the address and size of the
4541 environment area within the remote memory space. The
4542 local device can get the environment from remote memory
4543 space by SRIO or PCIE links.
4545 BE CAREFUL! For some special cases, the local device can not use
4546 "saveenv" command. For example, the local device will get the
4547 environment stored in a remote NOR flash by SRIO or PCIE link,
4548 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4550 - CONFIG_ENV_IS_IN_NAND:
4552 Define this if you have a NAND device which you want to use
4553 for the environment.
4555 - CONFIG_ENV_OFFSET:
4558 These two #defines specify the offset and size of the environment
4559 area within the first NAND device. CONFIG_ENV_OFFSET must be
4560 aligned to an erase block boundary.
4562 - CONFIG_ENV_OFFSET_REDUND (optional):
4564 This setting describes a second storage area of CONFIG_ENV_SIZE
4565 size used to hold a redundant copy of the environment data, so
4566 that there is a valid backup copy in case there is a power failure
4567 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4568 aligned to an erase block boundary.
4570 - CONFIG_ENV_RANGE (optional):
4572 Specifies the length of the region in which the environment
4573 can be written. This should be a multiple of the NAND device's
4574 block size. Specifying a range with more erase blocks than
4575 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4576 the range to be avoided.
4578 - CONFIG_ENV_OFFSET_OOB (optional):
4580 Enables support for dynamically retrieving the offset of the
4581 environment from block zero's out-of-band data. The
4582 "nand env.oob" command can be used to record this offset.
4583 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4584 using CONFIG_ENV_OFFSET_OOB.
4586 - CONFIG_NAND_ENV_DST
4588 Defines address in RAM to which the nand_spl code should copy the
4589 environment. If redundant environment is used, it will be copied to
4590 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4592 - CONFIG_ENV_IS_IN_UBI:
4594 Define this if you have an UBI volume that you want to use for the
4595 environment. This has the benefit of wear-leveling the environment
4596 accesses, which is important on NAND.
4598 - CONFIG_ENV_UBI_PART:
4600 Define this to a string that is the mtd partition containing the UBI.
4602 - CONFIG_ENV_UBI_VOLUME:
4604 Define this to the name of the volume that you want to store the
4607 - CONFIG_ENV_UBI_VOLUME_REDUND:
4609 Define this to the name of another volume to store a second copy of
4610 the environment in. This will enable redundant environments in UBI.
4611 It is assumed that both volumes are in the same MTD partition.
4613 - CONFIG_UBI_SILENCE_MSG
4614 - CONFIG_UBIFS_SILENCE_MSG
4616 You will probably want to define these to avoid a really noisy system
4617 when storing the env in UBI.
4619 - CONFIG_ENV_IS_IN_FAT:
4620 Define this if you want to use the FAT file system for the environment.
4622 - FAT_ENV_INTERFACE:
4624 Define this to a string that is the name of the block device.
4626 - FAT_ENV_DEV_AND_PART:
4628 Define this to a string to specify the partition of the device. It can
4631 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4632 - "D:P": device D partition P. Error occurs if device D has no
4635 - "D" or "D:": device D partition 1 if device D has partition
4636 table, or the whole device D if has no partition
4638 - "D:auto": first partition in device D with bootable flag set.
4639 If none, first valid partition in device D. If no
4640 partition table then means device D.
4644 It's a string of the FAT file name. This file use to store the
4648 This should be defined. Otherwise it cannot save the environment file.
4650 - CONFIG_ENV_IS_IN_MMC:
4652 Define this if you have an MMC device which you want to use for the
4655 - CONFIG_SYS_MMC_ENV_DEV:
4657 Specifies which MMC device the environment is stored in.
4659 - CONFIG_SYS_MMC_ENV_PART (optional):
4661 Specifies which MMC partition the environment is stored in. If not
4662 set, defaults to partition 0, the user area. Common values might be
4663 1 (first MMC boot partition), 2 (second MMC boot partition).
4665 - CONFIG_ENV_OFFSET:
4668 These two #defines specify the offset and size of the environment
4669 area within the specified MMC device.
4671 If offset is positive (the usual case), it is treated as relative to
4672 the start of the MMC partition. If offset is negative, it is treated
4673 as relative to the end of the MMC partition. This can be useful if
4674 your board may be fitted with different MMC devices, which have
4675 different sizes for the MMC partitions, and you always want the
4676 environment placed at the very end of the partition, to leave the
4677 maximum possible space before it, to store other data.
4679 These two values are in units of bytes, but must be aligned to an
4680 MMC sector boundary.
4682 - CONFIG_ENV_OFFSET_REDUND (optional):
4684 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4685 hold a redundant copy of the environment data. This provides a
4686 valid backup copy in case the other copy is corrupted, e.g. due
4687 to a power failure during a "saveenv" operation.
4689 This value may also be positive or negative; this is handled in the
4690 same way as CONFIG_ENV_OFFSET.
4692 This value is also in units of bytes, but must also be aligned to
4693 an MMC sector boundary.
4695 - CONFIG_ENV_SIZE_REDUND (optional):
4697 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4698 set. If this value is set, it must be set to the same value as
4701 - CONFIG_SYS_SPI_INIT_OFFSET
4703 Defines offset to the initial SPI buffer area in DPRAM. The
4704 area is used at an early stage (ROM part) if the environment
4705 is configured to reside in the SPI EEPROM: We need a 520 byte
4706 scratch DPRAM area. It is used between the two initialization
4707 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4708 to be a good choice since it makes it far enough from the
4709 start of the data area as well as from the stack pointer.
4711 Please note that the environment is read-only until the monitor
4712 has been relocated to RAM and a RAM copy of the environment has been
4713 created; also, when using EEPROM you will have to use getenv_f()
4714 until then to read environment variables.
4716 The environment is protected by a CRC32 checksum. Before the monitor
4717 is relocated into RAM, as a result of a bad CRC you will be working
4718 with the compiled-in default environment - *silently*!!! [This is
4719 necessary, because the first environment variable we need is the
4720 "baudrate" setting for the console - if we have a bad CRC, we don't
4721 have any device yet where we could complain.]
4723 Note: once the monitor has been relocated, then it will complain if
4724 the default environment is used; a new CRC is computed as soon as you
4725 use the "saveenv" command to store a valid environment.
4727 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4728 Echo the inverted Ethernet link state to the fault LED.
4730 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4731 also needs to be defined.
4733 - CONFIG_SYS_FAULT_MII_ADDR:
4734 MII address of the PHY to check for the Ethernet link state.
4736 - CONFIG_NS16550_MIN_FUNCTIONS:
4737 Define this if you desire to only have use of the NS16550_init
4738 and NS16550_putc functions for the serial driver located at
4739 drivers/serial/ns16550.c. This option is useful for saving
4740 space for already greatly restricted images, including but not
4741 limited to NAND_SPL configurations.
4743 - CONFIG_DISPLAY_BOARDINFO
4744 Display information about the board that U-Boot is running on
4745 when U-Boot starts up. The board function checkboard() is called
4748 - CONFIG_DISPLAY_BOARDINFO_LATE
4749 Similar to the previous option, but display this information
4750 later, once stdio is running and output goes to the LCD, if
4753 - CONFIG_BOARD_SIZE_LIMIT:
4754 Maximum size of the U-Boot image. When defined, the
4755 build system checks that the actual size does not
4758 Low Level (hardware related) configuration options:
4759 ---------------------------------------------------
4761 - CONFIG_SYS_CACHELINE_SIZE:
4762 Cache Line Size of the CPU.
4764 - CONFIG_SYS_DEFAULT_IMMR:
4765 Default address of the IMMR after system reset.
4767 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4768 and RPXsuper) to be able to adjust the position of
4769 the IMMR register after a reset.
4771 - CONFIG_SYS_CCSRBAR_DEFAULT:
4772 Default (power-on reset) physical address of CCSR on Freescale
4775 - CONFIG_SYS_CCSRBAR:
4776 Virtual address of CCSR. On a 32-bit build, this is typically
4777 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4779 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4780 for cross-platform code that uses that macro instead.
4782 - CONFIG_SYS_CCSRBAR_PHYS:
4783 Physical address of CCSR. CCSR can be relocated to a new
4784 physical address, if desired. In this case, this macro should
4785 be set to that address. Otherwise, it should be set to the
4786 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4787 is typically relocated on 36-bit builds. It is recommended
4788 that this macro be defined via the _HIGH and _LOW macros:
4790 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4791 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4793 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4794 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4795 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4796 used in assembly code, so it must not contain typecasts or
4797 integer size suffixes (e.g. "ULL").
4799 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4800 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4801 used in assembly code, so it must not contain typecasts or
4802 integer size suffixes (e.g. "ULL").
4804 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4805 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4806 forced to a value that ensures that CCSR is not relocated.
4808 - Floppy Disk Support:
4809 CONFIG_SYS_FDC_DRIVE_NUMBER
4811 the default drive number (default value 0)
4813 CONFIG_SYS_ISA_IO_STRIDE
4815 defines the spacing between FDC chipset registers
4818 CONFIG_SYS_ISA_IO_OFFSET
4820 defines the offset of register from address. It
4821 depends on which part of the data bus is connected to
4822 the FDC chipset. (default value 0)
4824 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4825 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4828 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4829 fdc_hw_init() is called at the beginning of the FDC
4830 setup. fdc_hw_init() must be provided by the board
4831 source code. It is used to make hardware-dependent
4835 Most IDE controllers were designed to be connected with PCI
4836 interface. Only few of them were designed for AHB interface.
4837 When software is doing ATA command and data transfer to
4838 IDE devices through IDE-AHB controller, some additional
4839 registers accessing to these kind of IDE-AHB controller
4842 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4843 DO NOT CHANGE unless you know exactly what you're
4844 doing! (11-4) [MPC8xx/82xx systems only]
4846 - CONFIG_SYS_INIT_RAM_ADDR:
4848 Start address of memory area that can be used for
4849 initial data and stack; please note that this must be
4850 writable memory that is working WITHOUT special
4851 initialization, i. e. you CANNOT use normal RAM which
4852 will become available only after programming the
4853 memory controller and running certain initialization
4856 U-Boot uses the following memory types:
4857 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4858 - MPC824X: data cache
4859 - PPC4xx: data cache
4861 - CONFIG_SYS_GBL_DATA_OFFSET:
4863 Offset of the initial data structure in the memory
4864 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4865 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4866 data is located at the end of the available space
4867 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4868 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4869 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4870 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4873 On the MPC824X (or other systems that use the data
4874 cache for initial memory) the address chosen for
4875 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4876 point to an otherwise UNUSED address space between
4877 the top of RAM and the start of the PCI space.
4879 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4881 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4883 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4885 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4887 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4889 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4891 - CONFIG_SYS_OR_TIMING_SDRAM:
4894 - CONFIG_SYS_MAMR_PTA:
4895 periodic timer for refresh
4897 - CONFIG_SYS_DER: Debug Event Register (37-47)
4899 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4900 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4901 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4902 CONFIG_SYS_BR1_PRELIM:
4903 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4905 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4906 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4907 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4908 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4910 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4911 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4912 Machine Mode Register and Memory Periodic Timer
4913 Prescaler definitions (SDRAM timing)
4915 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4916 enable I2C microcode relocation patch (MPC8xx);
4917 define relocation offset in DPRAM [DSP2]
4919 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4920 enable SMC microcode relocation patch (MPC8xx);
4921 define relocation offset in DPRAM [SMC1]
4923 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4924 enable SPI microcode relocation patch (MPC8xx);
4925 define relocation offset in DPRAM [SCC4]
4927 - CONFIG_SYS_USE_OSCCLK:
4928 Use OSCM clock mode on MBX8xx board. Be careful,
4929 wrong setting might damage your board. Read
4930 doc/README.MBX before setting this variable!
4932 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4933 Offset of the bootmode word in DPRAM used by post
4934 (Power On Self Tests). This definition overrides
4935 #define'd default value in commproc.h resp.
4938 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4939 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4940 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4941 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4942 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4943 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4944 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4945 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4946 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4948 - CONFIG_PCI_DISABLE_PCIE:
4949 Disable PCI-Express on systems where it is supported but not
4952 - CONFIG_PCI_ENUM_ONLY
4953 Only scan through and get the devices on the buses.
4954 Don't do any setup work, presumably because someone or
4955 something has already done it, and we don't need to do it
4956 a second time. Useful for platforms that are pre-booted
4957 by coreboot or similar.
4959 - CONFIG_PCI_INDIRECT_BRIDGE:
4960 Enable support for indirect PCI bridges.
4963 Chip has SRIO or not
4966 Board has SRIO 1 port available
4969 Board has SRIO 2 port available
4971 - CONFIG_SRIO_PCIE_BOOT_MASTER
4972 Board can support master function for Boot from SRIO and PCIE
4974 - CONFIG_SYS_SRIOn_MEM_VIRT:
4975 Virtual Address of SRIO port 'n' memory region
4977 - CONFIG_SYS_SRIOn_MEM_PHYS:
4978 Physical Address of SRIO port 'n' memory region
4980 - CONFIG_SYS_SRIOn_MEM_SIZE:
4981 Size of SRIO port 'n' memory region
4983 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4984 Defined to tell the NAND controller that the NAND chip is using
4986 Not all NAND drivers use this symbol.
4987 Example of drivers that use it:
4988 - drivers/mtd/nand/ndfc.c
4989 - drivers/mtd/nand/mxc_nand.c
4991 - CONFIG_SYS_NDFC_EBC0_CFG
4992 Sets the EBC0_CFG register for the NDFC. If not defined
4993 a default value will be used.
4996 Get DDR timing information from an I2C EEPROM. Common
4997 with pluggable memory modules such as SODIMMs
5000 I2C address of the SPD EEPROM
5002 - CONFIG_SYS_SPD_BUS_NUM
5003 If SPD EEPROM is on an I2C bus other than the first
5004 one, specify here. Note that the value must resolve
5005 to something your driver can deal with.
5007 - CONFIG_SYS_DDR_RAW_TIMING
5008 Get DDR timing information from other than SPD. Common with
5009 soldered DDR chips onboard without SPD. DDR raw timing
5010 parameters are extracted from datasheet and hard-coded into
5011 header files or board specific files.
5013 - CONFIG_FSL_DDR_INTERACTIVE
5014 Enable interactive DDR debugging. See doc/README.fsl-ddr.
5016 - CONFIG_FSL_DDR_SYNC_REFRESH
5017 Enable sync of refresh for multiple controllers.
5019 - CONFIG_SYS_83XX_DDR_USES_CS0
5020 Only for 83xx systems. If specified, then DDR should
5021 be configured using CS0 and CS1 instead of CS2 and CS3.
5023 - CONFIG_ETHER_ON_FEC[12]
5024 Define to enable FEC[12] on a 8xx series processor.
5026 - CONFIG_FEC[12]_PHY
5027 Define to the hardcoded PHY address which corresponds
5028 to the given FEC; i. e.
5029 #define CONFIG_FEC1_PHY 4
5030 means that the PHY with address 4 is connected to FEC1
5032 When set to -1, means to probe for first available.
5034 - CONFIG_FEC[12]_PHY_NORXERR
5035 The PHY does not have a RXERR line (RMII only).
5036 (so program the FEC to ignore it).
5039 Enable RMII mode for all FECs.
5040 Note that this is a global option, we can't
5041 have one FEC in standard MII mode and another in RMII mode.
5043 - CONFIG_CRC32_VERIFY
5044 Add a verify option to the crc32 command.
5047 => crc32 -v <address> <count> <crc32>
5049 Where address/count indicate a memory area
5050 and crc32 is the correct crc32 which the
5054 Add the "loopw" memory command. This only takes effect if
5055 the memory commands are activated globally (CONFIG_CMD_MEM).
5058 Add the "mdc" and "mwc" memory commands. These are cyclic
5063 This command will print 4 bytes (10,11,12,13) each 500 ms.
5065 => mwc.l 100 12345678 10
5066 This command will write 12345678 to address 100 all 10 ms.
5068 This only takes effect if the memory commands are activated
5069 globally (CONFIG_CMD_MEM).
5071 - CONFIG_SKIP_LOWLEVEL_INIT
5072 [ARM, NDS32, MIPS only] If this variable is defined, then certain
5073 low level initializations (like setting up the memory
5074 controller) are omitted and/or U-Boot does not
5075 relocate itself into RAM.
5077 Normally this variable MUST NOT be defined. The only
5078 exception is when U-Boot is loaded (to RAM) by some
5079 other boot loader or by a debugger which performs
5080 these initializations itself.
5083 Modifies the behaviour of start.S when compiling a loader
5084 that is executed before the actual U-Boot. E.g. when
5085 compiling a NAND SPL.
5088 Modifies the behaviour of start.S when compiling a loader
5089 that is executed after the SPL and before the actual U-Boot.
5090 It is loaded by the SPL.
5092 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5093 Only for 85xx systems. If this variable is specified, the section
5094 .resetvec is not kept and the section .bootpg is placed in the
5095 previous 4k of the .text section.
5097 - CONFIG_ARCH_MAP_SYSMEM
5098 Generally U-Boot (and in particular the md command) uses
5099 effective address. It is therefore not necessary to regard
5100 U-Boot address as virtual addresses that need to be translated
5101 to physical addresses. However, sandbox requires this, since
5102 it maintains its own little RAM buffer which contains all
5103 addressable memory. This option causes some memory accesses
5104 to be mapped through map_sysmem() / unmap_sysmem().
5106 - CONFIG_USE_ARCH_MEMCPY
5107 CONFIG_USE_ARCH_MEMSET
5108 If these options are used a optimized version of memcpy/memset will
5109 be used if available. These functions may be faster under some
5110 conditions but may increase the binary size.
5112 - CONFIG_X86_RESET_VECTOR
5113 If defined, the x86 reset vector code is included. This is not
5114 needed when U-Boot is running from Coreboot.
5117 Defines the MPU clock speed (in MHz).
5119 NOTE : currently only supported on AM335x platforms.
5121 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5122 Enables the RTC32K OSC on AM33xx based plattforms
5124 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5125 Option to disable subpage write in NAND driver
5126 driver that uses this:
5127 drivers/mtd/nand/davinci_nand.c
5129 Freescale QE/FMAN Firmware Support:
5130 -----------------------------------
5132 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5133 loading of "firmware", which is encoded in the QE firmware binary format.
5134 This firmware often needs to be loaded during U-Boot booting, so macros
5135 are used to identify the storage device (NOR flash, SPI, etc) and the address
5138 - CONFIG_SYS_FMAN_FW_ADDR
5139 The address in the storage device where the FMAN microcode is located. The
5140 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5143 - CONFIG_SYS_QE_FW_ADDR
5144 The address in the storage device where the QE microcode is located. The
5145 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5148 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5149 The maximum possible size of the firmware. The firmware binary format
5150 has a field that specifies the actual size of the firmware, but it
5151 might not be possible to read any part of the firmware unless some
5152 local storage is allocated to hold the entire firmware first.
5154 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5155 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5156 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5157 virtual address in NOR flash.
5159 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5160 Specifies that QE/FMAN firmware is located in NAND flash.
5161 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5163 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5164 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5165 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5167 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5168 Specifies that QE/FMAN firmware is located on the primary SPI
5169 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5171 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5172 Specifies that QE/FMAN firmware is located in the remote (master)
5173 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5174 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5175 window->master inbound window->master LAW->the ucode address in
5176 master's memory space.
5178 Freescale Layerscape Management Complex Firmware Support:
5179 ---------------------------------------------------------
5180 The Freescale Layerscape Management Complex (MC) supports the loading of
5182 This firmware often needs to be loaded during U-Boot booting, so macros
5183 are used to identify the storage device (NOR flash, SPI, etc) and the address
5186 - CONFIG_FSL_MC_ENET
5187 Enable the MC driver for Layerscape SoCs.
5189 - CONFIG_SYS_LS_MC_FW_ADDR
5190 The address in the storage device where the firmware is located. The
5191 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5194 - CONFIG_SYS_LS_MC_FW_LENGTH
5195 The maximum possible size of the firmware. The firmware binary format
5196 has a field that specifies the actual size of the firmware, but it
5197 might not be possible to read any part of the firmware unless some
5198 local storage is allocated to hold the entire firmware first.
5200 - CONFIG_SYS_LS_MC_FW_IN_NOR
5201 Specifies that MC firmware is located in NOR flash, mapped as
5202 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5203 virtual address in NOR flash.
5205 Building the Software:
5206 ======================
5208 Building U-Boot has been tested in several native build environments
5209 and in many different cross environments. Of course we cannot support
5210 all possibly existing versions of cross development tools in all
5211 (potentially obsolete) versions. In case of tool chain problems we
5212 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5213 which is extensively used to build and test U-Boot.
5215 If you are not using a native environment, it is assumed that you
5216 have GNU cross compiling tools available in your path. In this case,
5217 you must set the environment variable CROSS_COMPILE in your shell.
5218 Note that no changes to the Makefile or any other source files are
5219 necessary. For example using the ELDK on a 4xx CPU, please enter:
5221 $ CROSS_COMPILE=ppc_4xx-
5222 $ export CROSS_COMPILE
5224 Note: If you wish to generate Windows versions of the utilities in
5225 the tools directory you can use the MinGW toolchain
5226 (http://www.mingw.org). Set your HOST tools to the MinGW
5227 toolchain and execute 'make tools'. For example:
5229 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5231 Binaries such as tools/mkimage.exe will be created which can
5232 be executed on computers running Windows.
5234 U-Boot is intended to be simple to build. After installing the
5235 sources you must configure U-Boot for one specific board type. This
5240 where "NAME_defconfig" is the name of one of the existing configu-
5241 rations; see boards.cfg for supported names.
5243 Note: for some board special configuration names may exist; check if
5244 additional information is available from the board vendor; for
5245 instance, the TQM823L systems are available without (standard)
5246 or with LCD support. You can select such additional "features"
5247 when choosing the configuration, i. e.
5249 make TQM823L_defconfig
5250 - will configure for a plain TQM823L, i. e. no LCD support
5252 make TQM823L_LCD_defconfig
5253 - will configure for a TQM823L with U-Boot console on LCD
5258 Finally, type "make all", and you should get some working U-Boot
5259 images ready for download to / installation on your system:
5261 - "u-boot.bin" is a raw binary image
5262 - "u-boot" is an image in ELF binary format
5263 - "u-boot.srec" is in Motorola S-Record format
5265 By default the build is performed locally and the objects are saved
5266 in the source directory. One of the two methods can be used to change
5267 this behavior and build U-Boot to some external directory:
5269 1. Add O= to the make command line invocations:
5271 make O=/tmp/build distclean
5272 make O=/tmp/build NAME_defconfig
5273 make O=/tmp/build all
5275 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5277 export KBUILD_OUTPUT=/tmp/build
5282 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5286 Please be aware that the Makefiles assume you are using GNU make, so
5287 for instance on NetBSD you might need to use "gmake" instead of
5291 If the system board that you have is not listed, then you will need
5292 to port U-Boot to your hardware platform. To do this, follow these
5295 1. Add a new configuration option for your board to the toplevel
5296 "boards.cfg" file, using the existing entries as examples.
5297 Follow the instructions there to keep the boards in order.
5298 2. Create a new directory to hold your board specific code. Add any
5299 files you need. In your board directory, you will need at least
5300 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5301 3. Create a new configuration file "include/configs/<board>.h" for
5303 3. If you're porting U-Boot to a new CPU, then also create a new
5304 directory to hold your CPU specific code. Add any files you need.
5305 4. Run "make <board>_defconfig" with your new name.
5306 5. Type "make", and you should get a working "u-boot.srec" file
5307 to be installed on your target system.
5308 6. Debug and solve any problems that might arise.
5309 [Of course, this last step is much harder than it sounds.]
5312 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5313 ==============================================================
5315 If you have modified U-Boot sources (for instance added a new board
5316 or support for new devices, a new CPU, etc.) you are expected to
5317 provide feedback to the other developers. The feedback normally takes
5318 the form of a "patch", i. e. a context diff against a certain (latest
5319 official or latest in the git repository) version of U-Boot sources.
5321 But before you submit such a patch, please verify that your modifi-
5322 cation did not break existing code. At least make sure that *ALL* of
5323 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5324 just run the "MAKEALL" script, which will configure and build U-Boot
5325 for ALL supported system. Be warned, this will take a while. You can
5326 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5327 environment variable to the script, i. e. to use the ELDK cross tools
5330 CROSS_COMPILE=ppc_8xx- MAKEALL
5332 or to build on a native PowerPC system you can type
5334 CROSS_COMPILE=' ' MAKEALL
5336 When using the MAKEALL script, the default behaviour is to build
5337 U-Boot in the source directory. This location can be changed by
5338 setting the BUILD_DIR environment variable. Also, for each target
5339 built, the MAKEALL script saves two log files (<target>.ERR and
5340 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5341 location can be changed by setting the MAKEALL_LOGDIR environment
5342 variable. For example:
5344 export BUILD_DIR=/tmp/build
5345 export MAKEALL_LOGDIR=/tmp/log
5346 CROSS_COMPILE=ppc_8xx- MAKEALL
5348 With the above settings build objects are saved in the /tmp/build,
5349 log files are saved in the /tmp/log and the source tree remains clean
5350 during the whole build process.
5353 See also "U-Boot Porting Guide" below.
5356 Monitor Commands - Overview:
5357 ============================
5359 go - start application at address 'addr'
5360 run - run commands in an environment variable
5361 bootm - boot application image from memory
5362 bootp - boot image via network using BootP/TFTP protocol
5363 bootz - boot zImage from memory
5364 tftpboot- boot image via network using TFTP protocol
5365 and env variables "ipaddr" and "serverip"
5366 (and eventually "gatewayip")
5367 tftpput - upload a file via network using TFTP protocol
5368 rarpboot- boot image via network using RARP/TFTP protocol
5369 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5370 loads - load S-Record file over serial line
5371 loadb - load binary file over serial line (kermit mode)
5373 mm - memory modify (auto-incrementing)
5374 nm - memory modify (constant address)
5375 mw - memory write (fill)
5377 cmp - memory compare
5378 crc32 - checksum calculation
5379 i2c - I2C sub-system
5380 sspi - SPI utility commands
5381 base - print or set address offset
5382 printenv- print environment variables
5383 setenv - set environment variables
5384 saveenv - save environment variables to persistent storage
5385 protect - enable or disable FLASH write protection
5386 erase - erase FLASH memory
5387 flinfo - print FLASH memory information
5388 nand - NAND memory operations (see doc/README.nand)
5389 bdinfo - print Board Info structure
5390 iminfo - print header information for application image
5391 coninfo - print console devices and informations
5392 ide - IDE sub-system
5393 loop - infinite loop on address range
5394 loopw - infinite write loop on address range
5395 mtest - simple RAM test
5396 icache - enable or disable instruction cache
5397 dcache - enable or disable data cache
5398 reset - Perform RESET of the CPU
5399 echo - echo args to console
5400 version - print monitor version
5401 help - print online help
5402 ? - alias for 'help'
5405 Monitor Commands - Detailed Description:
5406 ========================================
5410 For now: just type "help <command>".
5413 Environment Variables:
5414 ======================
5416 U-Boot supports user configuration using Environment Variables which
5417 can be made persistent by saving to Flash memory.
5419 Environment Variables are set using "setenv", printed using
5420 "printenv", and saved to Flash using "saveenv". Using "setenv"
5421 without a value can be used to delete a variable from the
5422 environment. As long as you don't save the environment you are
5423 working with an in-memory copy. In case the Flash area containing the
5424 environment is erased by accident, a default environment is provided.
5426 Some configuration options can be set using Environment Variables.
5428 List of environment variables (most likely not complete):
5430 baudrate - see CONFIG_BAUDRATE
5432 bootdelay - see CONFIG_BOOTDELAY
5434 bootcmd - see CONFIG_BOOTCOMMAND
5436 bootargs - Boot arguments when booting an RTOS image
5438 bootfile - Name of the image to load with TFTP
5440 bootm_low - Memory range available for image processing in the bootm
5441 command can be restricted. This variable is given as
5442 a hexadecimal number and defines lowest address allowed
5443 for use by the bootm command. See also "bootm_size"
5444 environment variable. Address defined by "bootm_low" is
5445 also the base of the initial memory mapping for the Linux
5446 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5449 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5450 This variable is given as a hexadecimal number and it
5451 defines the size of the memory region starting at base
5452 address bootm_low that is accessible by the Linux kernel
5453 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5454 as the default value if it is defined, and bootm_size is
5457 bootm_size - Memory range available for image processing in the bootm
5458 command can be restricted. This variable is given as
5459 a hexadecimal number and defines the size of the region
5460 allowed for use by the bootm command. See also "bootm_low"
5461 environment variable.
5463 updatefile - Location of the software update file on a TFTP server, used
5464 by the automatic software update feature. Please refer to
5465 documentation in doc/README.update for more details.
5467 autoload - if set to "no" (any string beginning with 'n'),
5468 "bootp" will just load perform a lookup of the
5469 configuration from the BOOTP server, but not try to
5470 load any image using TFTP
5472 autostart - if set to "yes", an image loaded using the "bootp",
5473 "rarpboot", "tftpboot" or "diskboot" commands will
5474 be automatically started (by internally calling
5477 If set to "no", a standalone image passed to the
5478 "bootm" command will be copied to the load address
5479 (and eventually uncompressed), but NOT be started.
5480 This can be used to load and uncompress arbitrary
5483 fdt_high - if set this restricts the maximum address that the
5484 flattened device tree will be copied into upon boot.
5485 For example, if you have a system with 1 GB memory
5486 at physical address 0x10000000, while Linux kernel
5487 only recognizes the first 704 MB as low memory, you
5488 may need to set fdt_high as 0x3C000000 to have the
5489 device tree blob be copied to the maximum address
5490 of the 704 MB low memory, so that Linux kernel can
5491 access it during the boot procedure.
5493 If this is set to the special value 0xFFFFFFFF then
5494 the fdt will not be copied at all on boot. For this
5495 to work it must reside in writable memory, have
5496 sufficient padding on the end of it for u-boot to
5497 add the information it needs into it, and the memory
5498 must be accessible by the kernel.
5500 fdtcontroladdr- if set this is the address of the control flattened
5501 device tree used by U-Boot when CONFIG_OF_CONTROL is
5504 i2cfast - (PPC405GP|PPC405EP only)
5505 if set to 'y' configures Linux I2C driver for fast
5506 mode (400kHZ). This environment variable is used in
5507 initialization code. So, for changes to be effective
5508 it must be saved and board must be reset.
5510 initrd_high - restrict positioning of initrd images:
5511 If this variable is not set, initrd images will be
5512 copied to the highest possible address in RAM; this
5513 is usually what you want since it allows for
5514 maximum initrd size. If for some reason you want to
5515 make sure that the initrd image is loaded below the
5516 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5517 variable to a value of "no" or "off" or "0".
5518 Alternatively, you can set it to a maximum upper
5519 address to use (U-Boot will still check that it
5520 does not overwrite the U-Boot stack and data).
5522 For instance, when you have a system with 16 MB
5523 RAM, and want to reserve 4 MB from use by Linux,
5524 you can do this by adding "mem=12M" to the value of
5525 the "bootargs" variable. However, now you must make
5526 sure that the initrd image is placed in the first
5527 12 MB as well - this can be done with
5529 setenv initrd_high 00c00000
5531 If you set initrd_high to 0xFFFFFFFF, this is an
5532 indication to U-Boot that all addresses are legal
5533 for the Linux kernel, including addresses in flash
5534 memory. In this case U-Boot will NOT COPY the
5535 ramdisk at all. This may be useful to reduce the
5536 boot time on your system, but requires that this
5537 feature is supported by your Linux kernel.
5539 ipaddr - IP address; needed for tftpboot command
5541 loadaddr - Default load address for commands like "bootp",
5542 "rarpboot", "tftpboot", "loadb" or "diskboot"
5544 loads_echo - see CONFIG_LOADS_ECHO
5546 serverip - TFTP server IP address; needed for tftpboot command
5548 bootretry - see CONFIG_BOOT_RETRY_TIME
5550 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5552 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5554 ethprime - controls which interface is used first.
5556 ethact - controls which interface is currently active.
5557 For example you can do the following
5559 => setenv ethact FEC
5560 => ping 192.168.0.1 # traffic sent on FEC
5561 => setenv ethact SCC
5562 => ping 10.0.0.1 # traffic sent on SCC
5564 ethrotate - When set to "no" U-Boot does not go through all
5565 available network interfaces.
5566 It just stays at the currently selected interface.
5568 netretry - When set to "no" each network operation will
5569 either succeed or fail without retrying.
5570 When set to "once" the network operation will
5571 fail when all the available network interfaces
5572 are tried once without success.
5573 Useful on scripts which control the retry operation
5576 npe_ucode - set load address for the NPE microcode
5578 silent_linux - If set then Linux will be told to boot silently, by
5579 changing the console to be empty. If "yes" it will be
5580 made silent. If "no" it will not be made silent. If
5581 unset, then it will be made silent if the U-Boot console
5584 tftpsrcport - If this is set, the value is used for TFTP's
5587 tftpdstport - If this is set, the value is used for TFTP's UDP
5588 destination port instead of the Well Know Port 69.
5590 tftpblocksize - Block size to use for TFTP transfers; if not set,
5591 we use the TFTP server's default block size
5593 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5594 seconds, minimum value is 1000 = 1 second). Defines
5595 when a packet is considered to be lost so it has to
5596 be retransmitted. The default is 5000 = 5 seconds.
5597 Lowering this value may make downloads succeed
5598 faster in networks with high packet loss rates or
5599 with unreliable TFTP servers.
5601 vlan - When set to a value < 4095 the traffic over
5602 Ethernet is encapsulated/received over 802.1q
5605 The following image location variables contain the location of images
5606 used in booting. The "Image" column gives the role of the image and is
5607 not an environment variable name. The other columns are environment
5608 variable names. "File Name" gives the name of the file on a TFTP
5609 server, "RAM Address" gives the location in RAM the image will be
5610 loaded to, and "Flash Location" gives the image's address in NOR
5611 flash or offset in NAND flash.
5613 *Note* - these variables don't have to be defined for all boards, some
5614 boards currenlty use other variables for these purposes, and some
5615 boards use these variables for other purposes.
5617 Image File Name RAM Address Flash Location
5618 ----- --------- ----------- --------------
5619 u-boot u-boot u-boot_addr_r u-boot_addr
5620 Linux kernel bootfile kernel_addr_r kernel_addr
5621 device tree blob fdtfile fdt_addr_r fdt_addr
5622 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5624 The following environment variables may be used and automatically
5625 updated by the network boot commands ("bootp" and "rarpboot"),
5626 depending the information provided by your boot server:
5628 bootfile - see above
5629 dnsip - IP address of your Domain Name Server
5630 dnsip2 - IP address of your secondary Domain Name Server
5631 gatewayip - IP address of the Gateway (Router) to use
5632 hostname - Target hostname
5634 netmask - Subnet Mask
5635 rootpath - Pathname of the root filesystem on the NFS server
5636 serverip - see above
5639 There are two special Environment Variables:
5641 serial# - contains hardware identification information such
5642 as type string and/or serial number
5643 ethaddr - Ethernet address
5645 These variables can be set only once (usually during manufacturing of
5646 the board). U-Boot refuses to delete or overwrite these variables
5647 once they have been set once.
5650 Further special Environment Variables:
5652 ver - Contains the U-Boot version string as printed
5653 with the "version" command. This variable is
5654 readonly (see CONFIG_VERSION_VARIABLE).
5657 Please note that changes to some configuration parameters may take
5658 only effect after the next boot (yes, that's just like Windoze :-).
5661 Callback functions for environment variables:
5662 ---------------------------------------------
5664 For some environment variables, the behavior of u-boot needs to change
5665 when their values are changed. This functionality allows functions to
5666 be associated with arbitrary variables. On creation, overwrite, or
5667 deletion, the callback will provide the opportunity for some side
5668 effect to happen or for the change to be rejected.
5670 The callbacks are named and associated with a function using the
5671 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5673 These callbacks are associated with variables in one of two ways. The
5674 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5675 in the board configuration to a string that defines a list of
5676 associations. The list must be in the following format:
5678 entry = variable_name[:callback_name]
5681 If the callback name is not specified, then the callback is deleted.
5682 Spaces are also allowed anywhere in the list.
5684 Callbacks can also be associated by defining the ".callbacks" variable
5685 with the same list format above. Any association in ".callbacks" will
5686 override any association in the static list. You can define
5687 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5688 ".callbacks" environment variable in the default or embedded environment.
5691 Command Line Parsing:
5692 =====================
5694 There are two different command line parsers available with U-Boot:
5695 the old "simple" one, and the much more powerful "hush" shell:
5697 Old, simple command line parser:
5698 --------------------------------
5700 - supports environment variables (through setenv / saveenv commands)
5701 - several commands on one line, separated by ';'
5702 - variable substitution using "... ${name} ..." syntax
5703 - special characters ('$', ';') can be escaped by prefixing with '\',
5705 setenv bootcmd bootm \${address}
5706 - You can also escape text by enclosing in single apostrophes, for example:
5707 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5712 - similar to Bourne shell, with control structures like
5713 if...then...else...fi, for...do...done; while...do...done,
5714 until...do...done, ...
5715 - supports environment ("global") variables (through setenv / saveenv
5716 commands) and local shell variables (through standard shell syntax
5717 "name=value"); only environment variables can be used with "run"
5723 (1) If a command line (or an environment variable executed by a "run"
5724 command) contains several commands separated by semicolon, and
5725 one of these commands fails, then the remaining commands will be
5728 (2) If you execute several variables with one call to run (i. e.
5729 calling run with a list of variables as arguments), any failing
5730 command will cause "run" to terminate, i. e. the remaining
5731 variables are not executed.
5733 Note for Redundant Ethernet Interfaces:
5734 =======================================
5736 Some boards come with redundant Ethernet interfaces; U-Boot supports
5737 such configurations and is capable of automatic selection of a
5738 "working" interface when needed. MAC assignment works as follows:
5740 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5741 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5742 "eth1addr" (=>eth1), "eth2addr", ...
5744 If the network interface stores some valid MAC address (for instance
5745 in SROM), this is used as default address if there is NO correspon-
5746 ding setting in the environment; if the corresponding environment
5747 variable is set, this overrides the settings in the card; that means:
5749 o If the SROM has a valid MAC address, and there is no address in the
5750 environment, the SROM's address is used.
5752 o If there is no valid address in the SROM, and a definition in the
5753 environment exists, then the value from the environment variable is
5756 o If both the SROM and the environment contain a MAC address, and
5757 both addresses are the same, this MAC address is used.
5759 o If both the SROM and the environment contain a MAC address, and the
5760 addresses differ, the value from the environment is used and a
5763 o If neither SROM nor the environment contain a MAC address, an error
5766 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5767 will be programmed into hardware as part of the initialization process. This
5768 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5769 The naming convention is as follows:
5770 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5775 U-Boot is capable of booting (and performing other auxiliary operations on)
5776 images in two formats:
5778 New uImage format (FIT)
5779 -----------------------
5781 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5782 to Flattened Device Tree). It allows the use of images with multiple
5783 components (several kernels, ramdisks, etc.), with contents protected by
5784 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5790 Old image format is based on binary files which can be basically anything,
5791 preceded by a special header; see the definitions in include/image.h for
5792 details; basically, the header defines the following image properties:
5794 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5795 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5796 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5797 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5799 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5800 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5801 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5802 * Compression Type (uncompressed, gzip, bzip2)
5808 The header is marked by a special Magic Number, and both the header
5809 and the data portions of the image are secured against corruption by
5816 Although U-Boot should support any OS or standalone application
5817 easily, the main focus has always been on Linux during the design of
5820 U-Boot includes many features that so far have been part of some
5821 special "boot loader" code within the Linux kernel. Also, any
5822 "initrd" images to be used are no longer part of one big Linux image;
5823 instead, kernel and "initrd" are separate images. This implementation
5824 serves several purposes:
5826 - the same features can be used for other OS or standalone
5827 applications (for instance: using compressed images to reduce the
5828 Flash memory footprint)
5830 - it becomes much easier to port new Linux kernel versions because
5831 lots of low-level, hardware dependent stuff are done by U-Boot
5833 - the same Linux kernel image can now be used with different "initrd"
5834 images; of course this also means that different kernel images can
5835 be run with the same "initrd". This makes testing easier (you don't
5836 have to build a new "zImage.initrd" Linux image when you just
5837 change a file in your "initrd"). Also, a field-upgrade of the
5838 software is easier now.
5844 Porting Linux to U-Boot based systems:
5845 ---------------------------------------
5847 U-Boot cannot save you from doing all the necessary modifications to
5848 configure the Linux device drivers for use with your target hardware
5849 (no, we don't intend to provide a full virtual machine interface to
5852 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5854 Just make sure your machine specific header file (for instance
5855 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5856 Information structure as we define in include/asm-<arch>/u-boot.h,
5857 and make sure that your definition of IMAP_ADDR uses the same value
5858 as your U-Boot configuration in CONFIG_SYS_IMMR.
5860 Note that U-Boot now has a driver model, a unified model for drivers.
5861 If you are adding a new driver, plumb it into driver model. If there
5862 is no uclass available, you are encouraged to create one. See
5866 Configuring the Linux kernel:
5867 -----------------------------
5869 No specific requirements for U-Boot. Make sure you have some root
5870 device (initial ramdisk, NFS) for your target system.
5873 Building a Linux Image:
5874 -----------------------
5876 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5877 not used. If you use recent kernel source, a new build target
5878 "uImage" will exist which automatically builds an image usable by
5879 U-Boot. Most older kernels also have support for a "pImage" target,
5880 which was introduced for our predecessor project PPCBoot and uses a
5881 100% compatible format.
5885 make TQM850L_defconfig
5890 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5891 encapsulate a compressed Linux kernel image with header information,
5892 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5894 * build a standard "vmlinux" kernel image (in ELF binary format):
5896 * convert the kernel into a raw binary image:
5898 ${CROSS_COMPILE}-objcopy -O binary \
5899 -R .note -R .comment \
5900 -S vmlinux linux.bin
5902 * compress the binary image:
5906 * package compressed binary image for U-Boot:
5908 mkimage -A ppc -O linux -T kernel -C gzip \
5909 -a 0 -e 0 -n "Linux Kernel Image" \
5910 -d linux.bin.gz uImage
5913 The "mkimage" tool can also be used to create ramdisk images for use
5914 with U-Boot, either separated from the Linux kernel image, or
5915 combined into one file. "mkimage" encapsulates the images with a 64
5916 byte header containing information about target architecture,
5917 operating system, image type, compression method, entry points, time
5918 stamp, CRC32 checksums, etc.
5920 "mkimage" can be called in two ways: to verify existing images and
5921 print the header information, or to build new images.
5923 In the first form (with "-l" option) mkimage lists the information
5924 contained in the header of an existing U-Boot image; this includes
5925 checksum verification:
5927 tools/mkimage -l image
5928 -l ==> list image header information
5930 The second form (with "-d" option) is used to build a U-Boot image
5931 from a "data file" which is used as image payload:
5933 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5934 -n name -d data_file image
5935 -A ==> set architecture to 'arch'
5936 -O ==> set operating system to 'os'
5937 -T ==> set image type to 'type'
5938 -C ==> set compression type 'comp'
5939 -a ==> set load address to 'addr' (hex)
5940 -e ==> set entry point to 'ep' (hex)
5941 -n ==> set image name to 'name'
5942 -d ==> use image data from 'datafile'
5944 Right now, all Linux kernels for PowerPC systems use the same load
5945 address (0x00000000), but the entry point address depends on the
5948 - 2.2.x kernels have the entry point at 0x0000000C,
5949 - 2.3.x and later kernels have the entry point at 0x00000000.
5951 So a typical call to build a U-Boot image would read:
5953 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5954 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5955 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5956 > examples/uImage.TQM850L
5957 Image Name: 2.4.4 kernel for TQM850L
5958 Created: Wed Jul 19 02:34:59 2000
5959 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5960 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5961 Load Address: 0x00000000
5962 Entry Point: 0x00000000
5964 To verify the contents of the image (or check for corruption):
5966 -> tools/mkimage -l examples/uImage.TQM850L
5967 Image Name: 2.4.4 kernel for TQM850L
5968 Created: Wed Jul 19 02:34:59 2000
5969 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5970 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5971 Load Address: 0x00000000
5972 Entry Point: 0x00000000
5974 NOTE: for embedded systems where boot time is critical you can trade
5975 speed for memory and install an UNCOMPRESSED image instead: this
5976 needs more space in Flash, but boots much faster since it does not
5977 need to be uncompressed:
5979 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5980 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5981 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5982 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5983 > examples/uImage.TQM850L-uncompressed
5984 Image Name: 2.4.4 kernel for TQM850L
5985 Created: Wed Jul 19 02:34:59 2000
5986 Image Type: PowerPC Linux Kernel Image (uncompressed)
5987 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5988 Load Address: 0x00000000
5989 Entry Point: 0x00000000
5992 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5993 when your kernel is intended to use an initial ramdisk:
5995 -> tools/mkimage -n 'Simple Ramdisk Image' \
5996 > -A ppc -O linux -T ramdisk -C gzip \
5997 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5998 Image Name: Simple Ramdisk Image
5999 Created: Wed Jan 12 14:01:50 2000
6000 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6001 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
6002 Load Address: 0x00000000
6003 Entry Point: 0x00000000
6005 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
6006 option performs the converse operation of the mkimage's second form (the "-d"
6007 option). Given an image built by mkimage, the dumpimage extracts a "data file"
6010 tools/dumpimage -i image -T type -p position data_file
6011 -i ==> extract from the 'image' a specific 'data_file'
6012 -T ==> set image type to 'type'
6013 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
6016 Installing a Linux Image:
6017 -------------------------
6019 To downloading a U-Boot image over the serial (console) interface,
6020 you must convert the image to S-Record format:
6022 objcopy -I binary -O srec examples/image examples/image.srec
6024 The 'objcopy' does not understand the information in the U-Boot
6025 image header, so the resulting S-Record file will be relative to
6026 address 0x00000000. To load it to a given address, you need to
6027 specify the target address as 'offset' parameter with the 'loads'
6030 Example: install the image to address 0x40100000 (which on the
6031 TQM8xxL is in the first Flash bank):
6033 => erase 40100000 401FFFFF
6039 ## Ready for S-Record download ...
6040 ~>examples/image.srec
6041 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
6043 15989 15990 15991 15992
6044 [file transfer complete]
6046 ## Start Addr = 0x00000000
6049 You can check the success of the download using the 'iminfo' command;
6050 this includes a checksum verification so you can be sure no data
6051 corruption happened:
6055 ## Checking Image at 40100000 ...
6056 Image Name: 2.2.13 for initrd on TQM850L
6057 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6058 Data Size: 335725 Bytes = 327 kB = 0 MB
6059 Load Address: 00000000
6060 Entry Point: 0000000c
6061 Verifying Checksum ... OK
6067 The "bootm" command is used to boot an application that is stored in
6068 memory (RAM or Flash). In case of a Linux kernel image, the contents
6069 of the "bootargs" environment variable is passed to the kernel as
6070 parameters. You can check and modify this variable using the
6071 "printenv" and "setenv" commands:
6074 => printenv bootargs
6075 bootargs=root=/dev/ram
6077 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6079 => printenv bootargs
6080 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6083 ## Booting Linux kernel at 40020000 ...
6084 Image Name: 2.2.13 for NFS on TQM850L
6085 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6086 Data Size: 381681 Bytes = 372 kB = 0 MB
6087 Load Address: 00000000
6088 Entry Point: 0000000c
6089 Verifying Checksum ... OK
6090 Uncompressing Kernel Image ... OK
6091 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
6092 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6093 time_init: decrementer frequency = 187500000/60
6094 Calibrating delay loop... 49.77 BogoMIPS
6095 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6098 If you want to boot a Linux kernel with initial RAM disk, you pass
6099 the memory addresses of both the kernel and the initrd image (PPBCOOT
6100 format!) to the "bootm" command:
6102 => imi 40100000 40200000
6104 ## Checking Image at 40100000 ...
6105 Image Name: 2.2.13 for initrd on TQM850L
6106 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6107 Data Size: 335725 Bytes = 327 kB = 0 MB
6108 Load Address: 00000000
6109 Entry Point: 0000000c
6110 Verifying Checksum ... OK
6112 ## Checking Image at 40200000 ...
6113 Image Name: Simple Ramdisk Image
6114 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6115 Data Size: 566530 Bytes = 553 kB = 0 MB
6116 Load Address: 00000000
6117 Entry Point: 00000000
6118 Verifying Checksum ... OK
6120 => bootm 40100000 40200000
6121 ## Booting Linux kernel at 40100000 ...
6122 Image Name: 2.2.13 for initrd on TQM850L
6123 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6124 Data Size: 335725 Bytes = 327 kB = 0 MB
6125 Load Address: 00000000
6126 Entry Point: 0000000c
6127 Verifying Checksum ... OK
6128 Uncompressing Kernel Image ... OK
6129 ## Loading RAMDisk Image at 40200000 ...
6130 Image Name: Simple Ramdisk Image
6131 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6132 Data Size: 566530 Bytes = 553 kB = 0 MB
6133 Load Address: 00000000
6134 Entry Point: 00000000
6135 Verifying Checksum ... OK
6136 Loading Ramdisk ... OK
6137 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
6138 Boot arguments: root=/dev/ram
6139 time_init: decrementer frequency = 187500000/60
6140 Calibrating delay loop... 49.77 BogoMIPS
6142 RAMDISK: Compressed image found at block 0
6143 VFS: Mounted root (ext2 filesystem).
6147 Boot Linux and pass a flat device tree:
6150 First, U-Boot must be compiled with the appropriate defines. See the section
6151 titled "Linux Kernel Interface" above for a more in depth explanation. The
6152 following is an example of how to start a kernel and pass an updated
6158 oft=oftrees/mpc8540ads.dtb
6159 => tftp $oftaddr $oft
6160 Speed: 1000, full duplex
6162 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6163 Filename 'oftrees/mpc8540ads.dtb'.
6164 Load address: 0x300000
6167 Bytes transferred = 4106 (100a hex)
6168 => tftp $loadaddr $bootfile
6169 Speed: 1000, full duplex
6171 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6173 Load address: 0x200000
6174 Loading:############
6176 Bytes transferred = 1029407 (fb51f hex)
6181 => bootm $loadaddr - $oftaddr
6182 ## Booting image at 00200000 ...
6183 Image Name: Linux-2.6.17-dirty
6184 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6185 Data Size: 1029343 Bytes = 1005.2 kB
6186 Load Address: 00000000
6187 Entry Point: 00000000
6188 Verifying Checksum ... OK
6189 Uncompressing Kernel Image ... OK
6190 Booting using flat device tree at 0x300000
6191 Using MPC85xx ADS machine description
6192 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6196 More About U-Boot Image Types:
6197 ------------------------------
6199 U-Boot supports the following image types:
6201 "Standalone Programs" are directly runnable in the environment
6202 provided by U-Boot; it is expected that (if they behave
6203 well) you can continue to work in U-Boot after return from
6204 the Standalone Program.
6205 "OS Kernel Images" are usually images of some Embedded OS which
6206 will take over control completely. Usually these programs
6207 will install their own set of exception handlers, device
6208 drivers, set up the MMU, etc. - this means, that you cannot
6209 expect to re-enter U-Boot except by resetting the CPU.
6210 "RAMDisk Images" are more or less just data blocks, and their
6211 parameters (address, size) are passed to an OS kernel that is
6213 "Multi-File Images" contain several images, typically an OS
6214 (Linux) kernel image and one or more data images like
6215 RAMDisks. This construct is useful for instance when you want
6216 to boot over the network using BOOTP etc., where the boot
6217 server provides just a single image file, but you want to get
6218 for instance an OS kernel and a RAMDisk image.
6220 "Multi-File Images" start with a list of image sizes, each
6221 image size (in bytes) specified by an "uint32_t" in network
6222 byte order. This list is terminated by an "(uint32_t)0".
6223 Immediately after the terminating 0 follow the images, one by
6224 one, all aligned on "uint32_t" boundaries (size rounded up to
6225 a multiple of 4 bytes).
6227 "Firmware Images" are binary images containing firmware (like
6228 U-Boot or FPGA images) which usually will be programmed to
6231 "Script files" are command sequences that will be executed by
6232 U-Boot's command interpreter; this feature is especially
6233 useful when you configure U-Boot to use a real shell (hush)
6234 as command interpreter.
6236 Booting the Linux zImage:
6237 -------------------------
6239 On some platforms, it's possible to boot Linux zImage. This is done
6240 using the "bootz" command. The syntax of "bootz" command is the same
6241 as the syntax of "bootm" command.
6243 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6244 kernel with raw initrd images. The syntax is slightly different, the
6245 address of the initrd must be augmented by it's size, in the following
6246 format: "<initrd addres>:<initrd size>".
6252 One of the features of U-Boot is that you can dynamically load and
6253 run "standalone" applications, which can use some resources of
6254 U-Boot like console I/O functions or interrupt services.
6256 Two simple examples are included with the sources:
6261 'examples/hello_world.c' contains a small "Hello World" Demo
6262 application; it is automatically compiled when you build U-Boot.
6263 It's configured to run at address 0x00040004, so you can play with it
6267 ## Ready for S-Record download ...
6268 ~>examples/hello_world.srec
6269 1 2 3 4 5 6 7 8 9 10 11 ...
6270 [file transfer complete]
6272 ## Start Addr = 0x00040004
6274 => go 40004 Hello World! This is a test.
6275 ## Starting application at 0x00040004 ...
6286 Hit any key to exit ...
6288 ## Application terminated, rc = 0x0
6290 Another example, which demonstrates how to register a CPM interrupt
6291 handler with the U-Boot code, can be found in 'examples/timer.c'.
6292 Here, a CPM timer is set up to generate an interrupt every second.
6293 The interrupt service routine is trivial, just printing a '.'
6294 character, but this is just a demo program. The application can be
6295 controlled by the following keys:
6297 ? - print current values og the CPM Timer registers
6298 b - enable interrupts and start timer
6299 e - stop timer and disable interrupts
6300 q - quit application
6303 ## Ready for S-Record download ...
6304 ~>examples/timer.srec
6305 1 2 3 4 5 6 7 8 9 10 11 ...
6306 [file transfer complete]
6308 ## Start Addr = 0x00040004
6311 ## Starting application at 0x00040004 ...
6314 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6317 [q, b, e, ?] Set interval 1000000 us
6320 [q, b, e, ?] ........
6321 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6324 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6327 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6330 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6332 [q, b, e, ?] ...Stopping timer
6334 [q, b, e, ?] ## Application terminated, rc = 0x0
6340 Over time, many people have reported problems when trying to use the
6341 "minicom" terminal emulation program for serial download. I (wd)
6342 consider minicom to be broken, and recommend not to use it. Under
6343 Unix, I recommend to use C-Kermit for general purpose use (and
6344 especially for kermit binary protocol download ("loadb" command), and
6345 use "cu" for S-Record download ("loads" command). See
6346 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6347 for help with kermit.
6350 Nevertheless, if you absolutely want to use it try adding this
6351 configuration to your "File transfer protocols" section:
6353 Name Program Name U/D FullScr IO-Red. Multi
6354 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6355 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6361 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6362 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6364 Building requires a cross environment; it is known to work on
6365 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6366 need gmake since the Makefiles are not compatible with BSD make).
6367 Note that the cross-powerpc package does not install include files;
6368 attempting to build U-Boot will fail because <machine/ansi.h> is
6369 missing. This file has to be installed and patched manually:
6371 # cd /usr/pkg/cross/powerpc-netbsd/include
6373 # ln -s powerpc machine
6374 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6375 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6377 Native builds *don't* work due to incompatibilities between native
6378 and U-Boot include files.
6380 Booting assumes that (the first part of) the image booted is a
6381 stage-2 loader which in turn loads and then invokes the kernel
6382 proper. Loader sources will eventually appear in the NetBSD source
6383 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6384 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6387 Implementation Internals:
6388 =========================
6390 The following is not intended to be a complete description of every
6391 implementation detail. However, it should help to understand the
6392 inner workings of U-Boot and make it easier to port it to custom
6396 Initial Stack, Global Data:
6397 ---------------------------
6399 The implementation of U-Boot is complicated by the fact that U-Boot
6400 starts running out of ROM (flash memory), usually without access to
6401 system RAM (because the memory controller is not initialized yet).
6402 This means that we don't have writable Data or BSS segments, and BSS
6403 is not initialized as zero. To be able to get a C environment working
6404 at all, we have to allocate at least a minimal stack. Implementation
6405 options for this are defined and restricted by the CPU used: Some CPU
6406 models provide on-chip memory (like the IMMR area on MPC8xx and
6407 MPC826x processors), on others (parts of) the data cache can be
6408 locked as (mis-) used as memory, etc.
6410 Chris Hallinan posted a good summary of these issues to the
6411 U-Boot mailing list:
6413 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6414 From: "Chris Hallinan" <clh@net1plus.com>
6415 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6418 Correct me if I'm wrong, folks, but the way I understand it
6419 is this: Using DCACHE as initial RAM for Stack, etc, does not
6420 require any physical RAM backing up the cache. The cleverness
6421 is that the cache is being used as a temporary supply of
6422 necessary storage before the SDRAM controller is setup. It's
6423 beyond the scope of this list to explain the details, but you
6424 can see how this works by studying the cache architecture and
6425 operation in the architecture and processor-specific manuals.
6427 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6428 is another option for the system designer to use as an
6429 initial stack/RAM area prior to SDRAM being available. Either
6430 option should work for you. Using CS 4 should be fine if your
6431 board designers haven't used it for something that would
6432 cause you grief during the initial boot! It is frequently not
6435 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6436 with your processor/board/system design. The default value
6437 you will find in any recent u-boot distribution in
6438 walnut.h should work for you. I'd set it to a value larger
6439 than your SDRAM module. If you have a 64MB SDRAM module, set
6440 it above 400_0000. Just make sure your board has no resources
6441 that are supposed to respond to that address! That code in
6442 start.S has been around a while and should work as is when
6443 you get the config right.
6448 It is essential to remember this, since it has some impact on the C
6449 code for the initialization procedures:
6451 * Initialized global data (data segment) is read-only. Do not attempt
6454 * Do not use any uninitialized global data (or implicitly initialized
6455 as zero data - BSS segment) at all - this is undefined, initiali-
6456 zation is performed later (when relocating to RAM).
6458 * Stack space is very limited. Avoid big data buffers or things like
6461 Having only the stack as writable memory limits means we cannot use
6462 normal global data to share information between the code. But it
6463 turned out that the implementation of U-Boot can be greatly
6464 simplified by making a global data structure (gd_t) available to all
6465 functions. We could pass a pointer to this data as argument to _all_
6466 functions, but this would bloat the code. Instead we use a feature of
6467 the GCC compiler (Global Register Variables) to share the data: we
6468 place a pointer (gd) to the global data into a register which we
6469 reserve for this purpose.
6471 When choosing a register for such a purpose we are restricted by the
6472 relevant (E)ABI specifications for the current architecture, and by
6473 GCC's implementation.
6475 For PowerPC, the following registers have specific use:
6477 R2: reserved for system use
6478 R3-R4: parameter passing and return values
6479 R5-R10: parameter passing
6480 R13: small data area pointer
6484 (U-Boot also uses R12 as internal GOT pointer. r12
6485 is a volatile register so r12 needs to be reset when
6486 going back and forth between asm and C)
6488 ==> U-Boot will use R2 to hold a pointer to the global data
6490 Note: on PPC, we could use a static initializer (since the
6491 address of the global data structure is known at compile time),
6492 but it turned out that reserving a register results in somewhat
6493 smaller code - although the code savings are not that big (on
6494 average for all boards 752 bytes for the whole U-Boot image,
6495 624 text + 127 data).
6497 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6498 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6500 ==> U-Boot will use P3 to hold a pointer to the global data
6502 On ARM, the following registers are used:
6504 R0: function argument word/integer result
6505 R1-R3: function argument word
6506 R9: platform specific
6507 R10: stack limit (used only if stack checking is enabled)
6508 R11: argument (frame) pointer
6509 R12: temporary workspace
6512 R15: program counter
6514 ==> U-Boot will use R9 to hold a pointer to the global data
6516 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6518 On Nios II, the ABI is documented here:
6519 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6521 ==> U-Boot will use gp to hold a pointer to the global data
6523 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6524 to access small data sections, so gp is free.
6526 On NDS32, the following registers are used:
6528 R0-R1: argument/return
6530 R15: temporary register for assembler
6531 R16: trampoline register
6532 R28: frame pointer (FP)
6533 R29: global pointer (GP)
6534 R30: link register (LP)
6535 R31: stack pointer (SP)
6536 PC: program counter (PC)
6538 ==> U-Boot will use R10 to hold a pointer to the global data
6540 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6541 or current versions of GCC may "optimize" the code too much.
6546 U-Boot runs in system state and uses physical addresses, i.e. the
6547 MMU is not used either for address mapping nor for memory protection.
6549 The available memory is mapped to fixed addresses using the memory
6550 controller. In this process, a contiguous block is formed for each
6551 memory type (Flash, SDRAM, SRAM), even when it consists of several
6552 physical memory banks.
6554 U-Boot is installed in the first 128 kB of the first Flash bank (on
6555 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6556 booting and sizing and initializing DRAM, the code relocates itself
6557 to the upper end of DRAM. Immediately below the U-Boot code some
6558 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6559 configuration setting]. Below that, a structure with global Board
6560 Info data is placed, followed by the stack (growing downward).
6562 Additionally, some exception handler code is copied to the low 8 kB
6563 of DRAM (0x00000000 ... 0x00001FFF).
6565 So a typical memory configuration with 16 MB of DRAM could look like
6568 0x0000 0000 Exception Vector code
6571 0x0000 2000 Free for Application Use
6577 0x00FB FF20 Monitor Stack (Growing downward)
6578 0x00FB FFAC Board Info Data and permanent copy of global data
6579 0x00FC 0000 Malloc Arena
6582 0x00FE 0000 RAM Copy of Monitor Code
6583 ... eventually: LCD or video framebuffer
6584 ... eventually: pRAM (Protected RAM - unchanged by reset)
6585 0x00FF FFFF [End of RAM]
6588 System Initialization:
6589 ----------------------
6591 In the reset configuration, U-Boot starts at the reset entry point
6592 (on most PowerPC systems at address 0x00000100). Because of the reset
6593 configuration for CS0# this is a mirror of the on board Flash memory.
6594 To be able to re-map memory U-Boot then jumps to its link address.
6595 To be able to implement the initialization code in C, a (small!)
6596 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6597 which provide such a feature like MPC8xx or MPC8260), or in a locked
6598 part of the data cache. After that, U-Boot initializes the CPU core,
6599 the caches and the SIU.
6601 Next, all (potentially) available memory banks are mapped using a
6602 preliminary mapping. For example, we put them on 512 MB boundaries
6603 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6604 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6605 programmed for SDRAM access. Using the temporary configuration, a
6606 simple memory test is run that determines the size of the SDRAM
6609 When there is more than one SDRAM bank, and the banks are of
6610 different size, the largest is mapped first. For equal size, the first
6611 bank (CS2#) is mapped first. The first mapping is always for address
6612 0x00000000, with any additional banks following immediately to create
6613 contiguous memory starting from 0.
6615 Then, the monitor installs itself at the upper end of the SDRAM area
6616 and allocates memory for use by malloc() and for the global Board
6617 Info data; also, the exception vector code is copied to the low RAM
6618 pages, and the final stack is set up.
6620 Only after this relocation will you have a "normal" C environment;
6621 until that you are restricted in several ways, mostly because you are
6622 running from ROM, and because the code will have to be relocated to a
6626 U-Boot Porting Guide:
6627 ----------------------
6629 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6633 int main(int argc, char *argv[])
6635 sighandler_t no_more_time;
6637 signal(SIGALRM, no_more_time);
6638 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6640 if (available_money > available_manpower) {
6641 Pay consultant to port U-Boot;
6645 Download latest U-Boot source;
6647 Subscribe to u-boot mailing list;
6650 email("Hi, I am new to U-Boot, how do I get started?");
6653 Read the README file in the top level directory;
6654 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6655 Read applicable doc/*.README;
6656 Read the source, Luke;
6657 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6660 if (available_money > toLocalCurrency ($2500))
6663 Add a lot of aggravation and time;
6665 if (a similar board exists) { /* hopefully... */
6666 cp -a board/<similar> board/<myboard>
6667 cp include/configs/<similar>.h include/configs/<myboard>.h
6669 Create your own board support subdirectory;
6670 Create your own board include/configs/<myboard>.h file;
6672 Edit new board/<myboard> files
6673 Edit new include/configs/<myboard>.h
6678 Add / modify source code;
6682 email("Hi, I am having problems...");
6684 Send patch file to the U-Boot email list;
6685 if (reasonable critiques)
6686 Incorporate improvements from email list code review;
6688 Defend code as written;
6694 void no_more_time (int sig)
6703 All contributions to U-Boot should conform to the Linux kernel
6704 coding style; see the file "Documentation/CodingStyle" and the script
6705 "scripts/Lindent" in your Linux kernel source directory.
6707 Source files originating from a different project (for example the
6708 MTD subsystem) are generally exempt from these guidelines and are not
6709 reformatted to ease subsequent migration to newer versions of those
6712 Please note that U-Boot is implemented in C (and to some small parts in
6713 Assembler); no C++ is used, so please do not use C++ style comments (//)
6716 Please also stick to the following formatting rules:
6717 - remove any trailing white space
6718 - use TAB characters for indentation and vertical alignment, not spaces
6719 - make sure NOT to use DOS '\r\n' line feeds
6720 - do not add more than 2 consecutive empty lines to source files
6721 - do not add trailing empty lines to source files
6723 Submissions which do not conform to the standards may be returned
6724 with a request to reformat the changes.
6730 Since the number of patches for U-Boot is growing, we need to
6731 establish some rules. Submissions which do not conform to these rules
6732 may be rejected, even when they contain important and valuable stuff.
6734 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6736 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6737 see http://lists.denx.de/mailman/listinfo/u-boot
6739 When you send a patch, please include the following information with
6742 * For bug fixes: a description of the bug and how your patch fixes
6743 this bug. Please try to include a way of demonstrating that the
6744 patch actually fixes something.
6746 * For new features: a description of the feature and your
6749 * A CHANGELOG entry as plaintext (separate from the patch)
6751 * For major contributions, your entry to the CREDITS file
6753 * When you add support for a new board, don't forget to add a
6754 maintainer e-mail address to the boards.cfg file, too.
6756 * If your patch adds new configuration options, don't forget to
6757 document these in the README file.
6759 * The patch itself. If you are using git (which is *strongly*
6760 recommended) you can easily generate the patch using the
6761 "git format-patch". If you then use "git send-email" to send it to
6762 the U-Boot mailing list, you will avoid most of the common problems
6763 with some other mail clients.
6765 If you cannot use git, use "diff -purN OLD NEW". If your version of
6766 diff does not support these options, then get the latest version of
6769 The current directory when running this command shall be the parent
6770 directory of the U-Boot source tree (i. e. please make sure that
6771 your patch includes sufficient directory information for the
6774 We prefer patches as plain text. MIME attachments are discouraged,
6775 and compressed attachments must not be used.
6777 * If one logical set of modifications affects or creates several
6778 files, all these changes shall be submitted in a SINGLE patch file.
6780 * Changesets that contain different, unrelated modifications shall be
6781 submitted as SEPARATE patches, one patch per changeset.
6786 * Before sending the patch, run the MAKEALL script on your patched
6787 source tree and make sure that no errors or warnings are reported
6788 for any of the boards.
6790 * Keep your modifications to the necessary minimum: A patch
6791 containing several unrelated changes or arbitrary reformats will be
6792 returned with a request to re-formatting / split it.
6794 * If you modify existing code, make sure that your new code does not
6795 add to the memory footprint of the code ;-) Small is beautiful!
6796 When adding new features, these should compile conditionally only
6797 (using #ifdef), and the resulting code with the new feature
6798 disabled must not need more memory than the old code without your
6801 * Remember that there is a size limit of 100 kB per message on the
6802 u-boot mailing list. Bigger patches will be moderated. If they are
6803 reasonable and not too big, they will be acknowledged. But patches
6804 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob